Local Anesthesia for Endovascular Repair of Abdominal Aortic Aneurysm Allows for Accurate Graft Deployment with Durable Results

BACKGROUND

Local anesthesia (LA) is sparsely used in endovascular aneurysm repair (EVAR) despite short-term benefit, likely secondary to concerns over patient movement preventing accurate endograft deployment. The objective of this study is to examine the association between anesthesia type and endoleak, sac regression, reintervention, and mortality.

METHODS

The Vascular Quality Initiative database was queried for all EVAR cases from 2014 to 2022. Patients were included if they underwent percutaneous elective EVAR with anatomical criteria within instructions for use of commercially approved endografts. Multivariable logistic regression with propensity score weighting was used to determine the association between anesthesia type on the risk of any endoleak noted by intraoperative completion angiogram and sac regression. Multivariable survival analysis with propensity score weighting was used to determine the association between anesthesia type and endoleak at 1 year, long-term reintervention, and mortality.

RESULTS

Thirteen thousand nine hundred thirty two EVARs met inclusion criteria: 1,075 (8%) LA and 12,857 (92%) general anesthesia (GA). On completion angiogram, LA was associated with fewer rates of any endoleaks overall (16% vs. 24%, P < 0.001). On multivariable analysis with propensity score weighting, LA was associated with similar adjusted odds of any endoleak on intraoperative completion angiogram (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.47-0.68) as well as combined type 1a and type 1b endoleaks (OR 0.72, 95% CI 0.47-1.09). Follow-up computed tomography imaging at 1 year was available for 4,892 patients, 377 (8%) LA and 4,515 (92%) GA. At 1 year, LA was associated with similar rate of freedom from any endoleaks compared to GA (0.66 [95% CI 0.63-0.69] vs. 0.71 [95% CI 0.70-0.72], P = 0.663) and increased rates of sac regression (50% vs. 45%, P = 0.040). On multivariable analysis with propensity score weighting, LA and GA were associated with similar adjusted odds of sac regression (OR 1.22, 95% CI 0.97-1.55). LA and GA had similar rates of endoleak at 1 year (hazard ratio [HR] 0.14, 95% CI 0.63-1.07); however, LA was associated with decreased hazards of combined type 1a and 1b endoleaks at 1 year (HR 0.87, 95% CI 0.80-0.96). LA and GA had similar adjusted long-term reintervention rate (HR 0.77, 95% CI 0.44-1.38) and long-term mortality (HR 1.100, 95% CI 079-1.25).

CONCLUSIONS

LA is not associated with increased adjusted rates of any endoleak on completion angiogram or at 1-year follow-up compared to GA. LA is associated with decreased adjusted rates of type 1a and type 1b endoleak at 1 year, but similar rates of sac regression, long-term reintervention, and mortality. Concerns for accurate graft deployment should not preclude use of LA and LA should be increasingly considered when deciding on anesthetic type for standard elective EVAR.

Assessment of fitness for open repair in patients with infrarenal abdominal aortic aneurysms

INTRODUCTION

Endovascular aortic repair (EVAR) was originally designed as a treatment modality for patients with abdominal aortic aneurysms (AAAs) deemed unfit for open repair. However, the definition of "unfit for open repair" is largely subjective and heterogenous. The purpose of this study was to compare patients deemed unfit for open repair who underwent EVAR to a matched cohort who underwent open repair for infrarenal AAAs.

METHODS

The Vascular Quality Initiative (VQI) of the Society for Vascular Surgery (SVS) was queried for patients who underwent EVAR and open infrarenal AAA repair from 2003-2022. Patients that underwent EVAR were included if they were deemed unfit for open repair by the operating surgeon. EVAR patients deemed unfit because of a hostile abdomen were excluded. Patients in both the open and EVAR datasets were excluded if their repair was deemed non-elective or if they had prior aortic surgery. EVAR patients were matched to a cohort of open patients. The primary outcome for this study was one-year mortality. Secondary outcomes included 30-day mortality, major adverse cardiac events (MACE), pulmonary complications, non-home discharge, re-interventions, and 5-year survival.

RESULTS

A total of 5,310 EVAR patients were identified who were deemed unfit for open repair. Of those, 3,028 (57.0%) EVAR patients were able to be matched 1:1 to a cohort of open patients. Open patients had higher rates of MACE (20.2% versus 4.4%, P<.001), pulmonary complications (12.8% versus 1.6%, P<.001), non-home discharges (28.5% versus 7.9%, P<.001), and 30-day mortality (4.5% versus 1.4%, P<.001). There were no differences in early survival but open repair had better middle and late survival compared to EVAR over the course of 5 years. A total of 74 (2.4%) EVAR patients had reinterventions during the study period. EVAR patients that required interventions had higher 1-year (40.5%% versus 7.3%, P<.001) and 5-year mortality (43.2% versus 14.1%, P<.001) compared to those that did not require re-interventions. EVAR patients who had reinterventions had higher 1-year (40.5% versus 6.3%, P<.001) and 5-year (43.2% versus 20.3%, P=.006) mortality compared to their matched open cohort.

CONCLUSION

Patients undergoing EVAR for AAAs who are deemed unfit for open repair have better perioperative morbidity and mortality compared to open. However, patients who had an open repair had better middle and late survival over the course of 5 years. The categorization of unfitness for open surgery may be inaccurate and re-evaluation of this terminology/concept should be undertaken.

Women Surgeons: Barriers and Solutions

OBJECTIVE

Underrepresentation and undertreatment of women in surgery continues to be highly prevalent, with major barriers to improvement. The aim of the study was to review the current state of women surgeons in Poland.

METHODS

Information from the various Polish databases on women surgeons in nine medical universities in general, oncological, vascular, thoracic, and cardiac surgery was retrospectively evaluated. Demographics of residents and staff surgeons, academic ranks and leadership positions at universities, in surgical societies and on scientific journals editorial boards were analyzed. Descriptive statistics were used.

RESULTS

In 2020, 61 % of 3668 graduates of Polish medical universities were women. In five surgical specialties 11.9% (1,243 of 10,411) of the surgeons were women, with the lowest numbers in cardiac (5.6%) and in vascular surgery (6.4%); 40.4% of general surgery residents were women, less in vascular (18.4%) and thoracic surgery (24%), more in oncological surgery (28.7%). In 35 surgical departments of nine universities all department chairs were men, all full professors were men; 7 % of associate professors, 16% of assistant professors were women. Rectors of all universities were men, 27% of the vice-rectors were women. In the senates and university councils, 39% and 35%, respectively, were women. Presidents, vice presidents, and secretaries of surgical societies and Editor-in-Chief of four surgical journals were all men.

CONCLUSIONS

Polish women surgeons face major difficulties with representation in surgery, in departmental, institutional, and societal leadership, and on scientific journal editorial boards. A multi-faceted approach to correct these serious inequalities is urgently needed.

Cutdown is Associated with Higher 30-day Unplanned Readmissions and Wound Complications Than Percutaneous Access for EVAR

OBJECTIVES

A 2023 Cochrane review showed no difference in bleeding/wound infection complications, short-term mortality and aneurysm exclusion between the percutaneous and cut-down approach for femoral access in endovascular aortic aneurysm repair (EVAR). In contrast, single-center studies have shown bilateral cutdown resulting in higher readmission rates due to higher rates of groin wound infections. Whether 30-day readmission rates vary by type of access during EVAR procedures is unknown. The goal of this study was to ascertain which femoral access approach for EVAR is associated with the lowest risk of 30-day readmission.

METHODS

The Targeted Vascular Module from the American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients undergoing EVAR for aortic disease from 2012-2021. All ruptures and other emergency cases were excluded. Cohorts were divided into bilateral cutdown, unilateral cutdown, failed percutaneous attempt converted to open and successful percutaneous access. The primary 30-day outcomes were unplanned readmission and wound complications. Univariate analyses were performed using the Fisher's exact test, Chi-Square test and the Student's t-test. Multivariable analysis was performed using logistic regression.

RESULTS

From 2012 to 2021, 14,002 patients met study criteria. Most (7,395 [53%]) underwent completely percutaneous access, 5,616 (40%) underwent bilateral cutdown, 849 (6%) underwent unilateral cutdown, and 146 (1%) had a failed percutaneous access which was converted to open. Unplanned readmissions by access strategy included 7.6% for bilateral cutdown, 7.3% for unilateral cutdown, 7.8% for attempted percutaneous converted to cutdown, and 5.7% for completely percutaneous access (p<.001, Figure 1). After multivariable analysis, unplanned readmissions compared to percutaneous access yielded: percutaneous converted to cutdown adjusted odds ratio (AOR): 1.38, 95% CI [0.76-2.53], p=.29; unilateral cutdown AOR: 1.18, 95% CI [0.92-1.51], p=.20; bilateral cutdown AOR: 1.26, 95% CI [1.09-1.43], p=.001. Bilateral cutdown was also associated with higher wound complications compared to percutaneous access (AOR: 4.41, CI [2.86-6.79], p<.001), as was unilateral cutdown (AOR: 3.04, CI [1.46-6.32], p=.003).

CONCLUSION

Patients undergoing cutdown for EVAR are at higher risk for 30-day readmission compared to completely percutaneous access. If patient anatomy allows for percutaneous EVAR, this access option should be prioritized.

The impact of sex on platelet responses to aspirin in patients with peripheral artery disease

Women with peripheral artery disease (PAD) have poorer limb salvage outcomes in spite of having lower risk factors for vascular disease than their male counterparts. Mono antiplatelet therapy with aspirin is the cornerstone of medical treatment for PAD to reduce the risk of arterial thrombosis, but platelets in women may have a variable response to this standard of care compared to men. Viscoelastic assays, such as thromboelastography with platelet mapping (TEG-PM), have been utilized to identify prothrombotic states and may provide insight into a patient's real-time coagulation profile and their response to specific antiplatelet medications. The aim of this prospective, observational study was to delineate the sex differences in platelet function using TEG-PM in patients with PAD on aspirin post-revascularization for PAD. All patients with PAD undergoing revascularization on aspirin monotherapy were prospectively enrolled between December 2020 and September 2023. The cohort was divided by sex, demographics, medications, procedure type, and outcomes were documented. Serial perioperative TEG-PM assays (1, 3, and 6 months) were performed up to 6 months postoperatively and platelet function was evaluated in both groups. Statistical analysis between women and men was performed to identify sex-specific differences in platelet function. Over the study period, a total of 303 patients were enrolled. Of this cohort, 149 patients met the study criteria and 266 samples were analyzed; 52 (34.89%) were women and 97 (65.11%) were men. In the platelet mapping assay, women showed significantly greater MAActF and MAAA, than men (16.66 vs. 14.94, p < .03 and 37.26 vs. 32.38, p < .01, respectively) indicating stronger thrombotic propensity. Additionally, platelet inhibition was significantly lower in women compared to men (52.95% vs. 61.65%, p < .05). In clinical outcomes reported as thrombotic events, women showed significantly higher occlusion in the area of intervention than men (4 vs. 1, p < .05). There is a growing awareness of the variations in the natural course, underlying mechanisms, and resulting outcomes of cardiovascular conditions, including PAD, in relation to sex. In this study, women did not achieve the same levels of platelet inhibition and displayed a procoagulant tendency in comparison to men when administered aspirin. Overall, aspirin monotherapy may be potentially sufficient for men, but women may require increased doses and/or additional antiplatelet medications to achieve an equivalent therapeutic effect.

Thromboelastography with Platelet Mapping Identifies High Platelet Reactivity is Associated with Obesity, Diabetes, and Thrombotic Events

BACKGROUND

Metabolic comorbidities such as diabetes and obesity are considered pro-inflammatory states which theoretically increase the risk of perioperative thrombotic events across many surgical disciplines. Currently, there is a paucity of objective metrics to determine such risk and ideal pharmacologic targets. Thromboelastography with Platelet Mapping (TEG-PM) provides a comprehensive profile of coagulation and may provide insight into clot dysregulation.

METHODS

Patients undergoing lower extremity revascularization underwent serial TEG-PM analysis. The relationship between the TEG-PM metrics and thrombosis was evaluated. Preoperative TEG-PM samples of patients with body mass index (BMI)≥25 were compared to those of patients with a normal BMI, and between patients with diabetes mellitus (DM) and those without.

RESULTS

218 TEG-PM samples from 202 patients were analyzed. The BMI≥25 cohort showed significantly greater platelet aggregation [81.9% (±20.9) vs. 68.6% (±27.7), P < 0.01]. Patients with DM were more frequently on full-dose anticoagulation [47.7% vs. 29.7% P = 0.01] yet demonstrated increased clot strength, or adenosine diphosphate (ADP)-Maximum Clot Amplitude (MA) [49.1 (±16.1) vs. 41.5 (±17.1) and 37.7 (±19.6) vs. 31.6 (±17.4) P < 0.01]. 49 patients experienced thrombosis and exhibited greater platelet aggregation [76.6% (±17.8) vs. 66.8% (±30.4) P = 0.03] and greater ADP/arachidonic acid MA [47.1 (±16.6) vs. 41.9 (±18.8) and 38.2 (±17.8) vs. 32.5 (±19.9) both P = 0.05]. Patients who thrombosed were more often diabetic [69.5% versus 51.0% P = 0.03] and on full-dose anticoagulation [75.0% vs. 56.8% P = 0.02].

CONCLUSIONS

Patients with a BMI≥ 25 and those with diabetes demonstrated TEG-PM profiles similar to patients with thrombosis. Diabetes was independently associated with thrombosis, and full-dose anticoagulation was not protective. This suggests the potential utility of TEG-PM for thrombotic risk stratification based on metabolic factors and suggests antiplatelet agents may be effective at prevention of thrombotic events in this population.

Optimizing platelet inhibition in peripheral artery disease: A comparison of mono-antiplatelet therapy and dual-antiplatelet therapy using thromboelastography

BACKGROUND

Antiplatelet therapy is used to prevent thrombosis in patients with peripheral artery disease (PAD) following revascularization. However, the current standard of care for these patients remains at the physician's discretion, varying from mono-antiplatelet therapy (MAPT) to dual-antiplatelet therapy (DAPT). Viscoelastic assays such as Thromboelastography with Platelet Mapping (TEG-PM) provide insight into individual coagulation profiles and measure real-time platelet function. This prospective, observational study looks at the differences in platelet function for patients on MAPT versus DAPT using TEG-PM.

METHODS

Patients with PAD undergoing revascularization were prospectively evaluated between December 2020 and June 2023. TEG-PM analysis compared platelet function for patients prescribed MAPT (aspirin or clopidogrel) at the initial encounter and DAPT (aspirin and clopidogrel) at the next visit. Platelet function measured in percent inhibition was evaluated at these visits, and within-group t-tests were performed.

RESULTS

Of the 195 patients enrolled, 486 samples were analyzed by TEG-PM. Sixty-four patients met the study criteria. At the initial visit, 52 patients had been prescribed aspirin, and 12 patients had been prescribed clopidogrel. For patients initially prescribed aspirin MAPT, an increase of 96.8%in the mean ADP platelet inhibition was exhibited when transitioning to DAPT [22.0% vs. 43.3%, p < .01], as well as an increase of 34.6%in the mean AA platelet inhibition when transitioning to DAPT [60.9% vs. 82.0%, p < .01]. For patients prescribed initial clopidogrel MAPT, an increase of 100% in AA platelet inhibition was exhibited on DAPT compared to the MAPT state [42.3% vs. 84.6%, p < .01].

CONCLUSIONS

Patients on DAPT showed a significant increase in platelet inhibition when compared to initial aspirin MAPT. A significant difference in AA %platelet inhibition was shown for patients on DAPT when compared to initial clopidogrel MAPT. The results show that patients may benefit from DAPT post-revascularization. Personalizing antiplatelet therapy with objective viscoelastic testing to confirm adequate treatment may be the next step in optimizing patient outcomes to reduce thrombosis in PAD patients.

Clinical Utility of Infrapopliteal Calcium Score for the Evaluation of Severity of Peripheral Artery Disease

PURPOSE

To identify associations between computed tomography (CT)-based lower-extremity calcium score (LECS) across different anatomic segments and the presence, severity, and clinical outcomes of peripheral artery disease (PAD).

MATERIALS AND METHODS

In a mixed retrospective and prospective cohort study, 139 patients without prior lower-extremity intervention who underwent CT angiography of the aorta and lower extremities were identified. Subjects were classified as asymptomatic, claudicants, or having chronic limb-threatening ischemia (CLTI). LECS was measured using the Agatston method. Univariate and multivariate analyses were performed across categories of PAD severity. Receiver operating characteristic (ROC) analysis was performed, and an optimal cutoff point for LECS was identified. Claudicants were followed prospectively for CLTI and mortality.

RESULTS

Higher infrapopliteal calcium score (CS) was independently associated with CLTI versus claudication (odds ratio [OR], 3.24 per unit increase in log10-transformed CS; P < .001) in addition to hemodialysis dependence and poor functional status. One hundred eighty-eight Agatston units was identified as the optimal cutoff for infrapopliteal CS in assessing the risk of CLTI versus claudication (area under the ROC curve, 0.84 [SD ± 0.049]). This cutoff was validated in an independent cohort to be associated with progression to CLTI (OR, 12.8; P = .0039). In the claudicant group followed prospectively, infrapopliteal CS ≥188 predicted increased risk of CLTI or death after adjusting for functional status and hemodialysis dependence (Cox hazard ratio, 4.92; P = .0202).

CONCLUSIONS

Higher infrapopliteal CS was associated with CLTI among those with symptomatic PAD. An infrapopliteal CS cutoff of 188 Agatston units may serve as a useful tool to identify patients with increased risk of CLTI and mortality.

Using Home-based, Remotely Supervised, Transcranial Direct Current Stimulation for Phantom Limb Pain

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that uses low-amplitude direct currents to alter cortical excitability. Previous trials have established the safety and tolerability of tDCS, and its potential to mitigate symptoms. However, the effects are cumulative, making it more difficult to have adherence to the treatment since frequent visits to the clinic or outpatient center are required. Moreover, the time needed for transportation to the center and the related expenses limit the accessibility of the treatment for many participants. Following guidelines for remotely supervised transcranial direct current stimulation (RS-tDCS) implementation, we propose a protocol designed for remotely supervised and home-based participation that uses specific devices and materials modified for patient use, with real-time monitoring by researchers through an encrypted video conferencing platform. We have developed detailed instructional materials and structured training procedures to allow for self- or proxy-administration while supervised remotely in real time. This protocol has a specific design to have a series of checkpoints during training and execution of the visit. This protocol is currently in use in a large pragmatic study of RS-tDCS for phantom limb pain (PLP). In this article, we will discuss the operational challenges of conducting a home-based RS-tDCS session and show methods to enhance its efficacy with supervised sessions.

Room for improvement in patient compliance during peripheral vascular interventions

Introduction

For patients receiving Procedural Sedation and Analgesia (PSA), patient cooperation is crucial as patients remain continuously aware of operating room activity and can be asked to perform tasks such as prolonged breath-holds. This survey aimed to collect information on patient compliance with on-table instructions and its relation to periprocedural outcomes from surgeons nationwide performing peripheral vascular interventions (PVI) under PSA.

Methods

A 9-question online survey was sent to 383 vascular surgeons (including both vascular surgery attendings and trainees) across the United States through REDCap from August 30 to September 21, 2021, with responses closed on October 30, 2021. The survey response was analyzed with descriptive statistics.

Results

83 (21.6%) vascular surgeons responded to the survey, of which 67 (80.7%) were attending vascular surgeons and 16 (19.3%) were vascular surgery trainees. 41 (49.4%) respondents performed 11-20 PVI cases under PSA every month, while 31 (41.0%) respondents performed 1-10 PVI cases under PSA every month. 41 (49.4%) respondents reported that in 1-10% of their cases, additional contrast and/or radiation was administered because patient moved on the table or did not cooperate with breath holds; 25 (30.1%) reported that this occurred in 11-20% of their cases, 12 (14.5%) reported that this occurred in 21-50% of their cases and 4 (4.8%) reported that this occurred in over 50% of their cases. In such cases, the majority of respondents reported a 1-10% increase in contrast volume (59.0%), radiation dosage (62.7%), sedative/analgesia administration (46.3%) and procedural time (54.9%). Of cases being converted to general anesthesia due to inadequate patient cooperation, 35 (42.2%) respondents reported between 1-5 per month, and 3 (3.6%) respondents reported between 6-10 per month. Of cases being aborted due to inadequate patient cooperation, 25 (30.1%) respondents reported between 1-5 per month, and 1 (1.2%) respondents reported between 6-10 per month.

Conclusion

A significant fraction of PVI cases performed under PSA result in increased radiation and contrast exposure, sedative administration and procedural time due to inadequate patient cooperation. In certain cases, conversion to general anesthesia or case abortion is required. Further research should be performed to investigate strategies to minimize such adverse patient safety events.

Comparison of Transcatheter Arterialization of Deep Veins to Standard of Care in Patients with No-Option Chronic Limb Threatening Ischemia

BACKGROUND

Patients with no-option chronic limb-threatening ischemia (no-option CLTI) have limited therapeutic options. The PROMISE II study evaluated, transcatheter arterialization of deep veins (TADV) as a treatment option for no-option CLTI. In the current study patients from PROMISE II were compared to patients from a registry of untreated no-option CLTI patients (CLariTI: Natural Progression of High-Risk Chronic Limb-Threatening Ischemia).

METHODS

We used propensity matching to compare patients from the PROMISE II prospective study of the TADV intervention with simultaneously enrolled CLTI patients that were note candidates for PROMISE II but were enrolled in to CLariTI natural history registry. Untreated no-option CLTI (CLariTI) patients could either be no-option or patients who did not meet PROMISE II entry criteria. Risk difference between groups was calculated using common risk difference and P values were provided by propensity-score stratified Mantel-Haenszel test. The primary endpoint was amputation-free survival (AFS).

RESULTS

Diabetes was present in over 75% of patients. All patients had tissue loss and 35-46% had extensive tissue loss (Rutherford 6). The unadjusted AFS at 6 months, was 66.1% by Kaplan-Meier estimate for PROMISE II patients (n = 105) compared to 39.1% in the no-option cohort of CLariTI (n = 121) and 44.0% in the full cohort (no-option and patients not meeting entry criteria combine, n = 180). The treatment group who underwent TADV for no-option CLTI had an absolute difference of 29% improved (P < 0.0001) propensity-adjusted risk difference in AFS and a relative event rate reduction of 45% compared to the no-option control patients.

CONCLUSIONS

Transcatheter arterialization of deep veins (TADV) resulted in improved 6 month AFS in no-option CLTI patients and appears to be a promising therapy in patients with no-option CLTI.

Multi-institutional outcomes after femoropopliteal bypass in octogenarians

OBJECTIVES

Open lower extremity revascularization is controversial among octogenarians; however, the indications for surgical bypass are higher in the elderly population. The aim of the study was to compare postoperative outcomes between octogenarians and non-octogenarians following femoropopliteal bypass surgery.

METHODS

Our regional, multi-institutional database was queried for femoropopliteal bypass procedures performed between 1995 and 2020. Electronic medical records were individually reviewed for operative and postoperative data. Univariable and multivariable logistic regression were utilized to determine predictors of postoperative outcomes.

RESULTS

Among 1315 patients who underwent femoropopliteal bypass, 234 (17.8%) were octogenarians. Octogenarians more frequently underwent bypass for lower extremity tissue loss (48.7% vs 30.2%), whereas claudication was more common among non-octogenarians (24.0% vs 9.8%) (p < .001). Below-knee bypass target (72.2% vs 59.3%) and prosthetic conduit utilization (58.5% vs 43.7%) were more frequent in octogenarians (p < .001 each). Overall hospital length of stay was longer among patients > 80 years (median 6 days [interquartile range [IQR] 4-9] vs 5 days [IQR 4-8], p = .017). The overall 30-day (5.6% vs 1.5%) and one-year mortality rates (25.6% vs 7.9%) were higher among octogenarians (p < .001 each). On multivariable analysis, age greater than 80 years was found to be an independent risk factor for postoperative mortality (OR 3.79 [1.75-8.20], p = .0007).

CONCLUSIONS

Octogenarians undergoing bypass femoropopliteal bypass surgery have considerably worse postoperative outcomes, compared with non-octogenarians. These data may help inform elderly patients prior to undergoing open lower extremity revascularization.

Popliteal artery aneurysm ultrasound criteria for reporting characteristics

INTRODUCTION

Duplex ultrasound (DUS) is the modality of choice for surveillance of popliteal artery aneurysms (PAAs). However, noninvasive vascular laboratories have no standard guidelines for reporting results. This study assessed reports of PAA DUS for inclusion of information pertinent to operative decision-making and timing of surveillance.

METHODS

This study was a retrospective review of a multi-institutional repository that was queried for all patients with a PAA from 2008 to 2022 and confirmed via manual chart review. DUS reports were abstracted and images were individually annotated for features of interest including dimensions, flow abnormalities, and percent thrombus burden.

RESULTS

A total of 166 PAAs in 130 patients had at least one DUS available for viewing. Postoperative surveillance of PAAs was performed at several intervals: the first at 30 months (IQR 3.7-113, n = 44), the second at 64 months (IQR 20-172, n = 31), and the third at 152 months (IQR 46-217, n = 16) after the operation. The largest diameter of operative PAAs (median 27.5 mm, IQR 21.8-38.0) was significantly greater than nonoperative PAAs (median 20.9 mm, IQR 16.7-27.3); p < 0.01. Fewer than 33 (21%) reports commented on patency of distal runoff. We calculated an average percent thrombus of 60% (IQR 19-81) in nonoperative PAAs, which is significantly smaller than 75% (IQR 58-89) in operative PAAs; p < 0.01.

CONCLUSION

In this multi-institutional retrospective study, PAAs are often not followed at intervals recommended by the Society for Vascular Surgery guidelines and do not include all measurements necessary for clinical decision-making in the multi-institutional repository studied. There should be standardization of PAA DUS protocols performed by all noninvasive vascular laboratories to ensure completeness of PAA DUS images and inclusion of characteristics pertinent to clinical decision-making in radiology reports.

Feasibility of Encord Artificial Intelligence Annotation of Arterial Duplex Ultrasound Images

DUS measurements for popliteal artery aneurysms (PAAs) specifically can be time-consuming, error-prone, and operator-dependent. To eliminate this subjectivity and provide efficient segmentation, we applied artificial intelligence (AI) to accurately delineate inner and outer lumen on DUS. DUS images were selected from a cohort of patients with PAAs from a multi-institutional platform. Encord is an easy-to-use, readily available online AI platform that was used to segment both the inner lumen and outer lumen of the PAA on DUS images. A model trained on 20 images and tested on 80 images had a mean Average Precision of 0.85 for the outer polygon and 0.23 for the inner polygon. The outer polygon had a higher recall score than precision score at 0.90 and 0.85, respectively. The inner polygon had a score of 0.25 for both precision and recall. The outer polygon false-negative rate was the lowest in images with the least amount of blur. This study demonstrates the feasibility of using the widely available Encord AI platform to identify standard features of PAAs that are critical for operative decision making.

Platelet function testing and clinical outcomes in peripheral arterial disease: Systematic review and narrative synthesis

OBJECTIVE

This systematic review aims to comprehensively assess the contemporary literature on platelet function testing (PFT) in individuals undergoing revascularization therapy for peripheral arterial disease (PAD). The goal is to identify whether PFT can aid in detecting antiplatelet resistance, predicting post-procedural thrombotic complications, and informing tailored treatment strategies.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a literature review was conducted using PubMed databases. Search terms included relevant medical subject headings (MeSH) terms. Eligible articles published in English between 1990 and 2023 were analyzed. Studies that examined PFT outcomes in patients with PAD after lower extremity revascularization were included.

RESULTS

Ten studies met the inclusion criteria. Various PFT methods were used, including thromboelastography with platelet mapping, multiplate analyzer, Cytochrome P450 2C19 testing, VerifyNow, corrected whole blood aggregometry, platelet function analyzer-100, and light transmission aggregometry. PFT identified individuals who were resistant or non-sensitive to antiplatelet therapy, with such patients facing increased risks of graft/stent thrombosis, amputation, and reintervention. However, substantial heterogeneity in surgical procedures, drug regimens, and testing methods was observed among the studies.

CONCLUSIONS

PFTs can play a crucial role in detecting resistance and non-sensitivity to antiplatelet drugs in patients with PAD post-revascularization. However, heterogeneity of data and methods underlines the need for standardized protocols and consensus-building among PFTs. Enhancing clinical utility and reliability could help optimize antiplatelet thromboprophylaxis, minimize thrombotic complications, and improve treatment strategies in vascular surgery. Further research is necessary to solidify the role of PFTs in guiding antiplatelet therapy post-revascularization in patients with PAD.

A systematic review of disparities in the medical management of atherosclerotic cardiovascular disease in females

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death in the United States and worldwide. Medical management of known modifiable risk factors, such as dyslipidemia, hypertension, and diabetes, is a key aspect to its treatment. Unfortunately, there are substantial sex-based differences in the treatment of ASCVD that result in poor medical management and worse clinical outcomes. The objective of this systematic review was to summarize known disparities in the medical management of ASCVD in females. We included prior studies with specific sex- and sex-based analyses regarding the medical treatment of the following three major disease entities within ASCVD: cerebrovascular disease, coronary artery disease, and peripheral artery disease. A total of 43 articles met inclusion criteria. In our analysis, we found that females were less likely to receive appropriate treatment of dyslipidemia or be prescribed antithrombotic medications. However, treatment differences for diabetes and hypertension by sex were not as clearly represented in the included studies. In addition to rectifying these disparities in the medical management of ASCVD, this systematic review highlights the need to address larger issues, such as underrepresentation of females in clinical trials, decreased access to care, and underdiagnosis of ASCVD to improve overall care for females.

Implementation of a Consensus-Driven Quality Improvement Protocol to Decrease Length of Stay after Elective Carotid Endarterectomy

BACKGROUND

National guidelines stipulate that postoperative length-of-stay (LOS) after elective carotid endarterectomy (CEA) should not exceed 1 day on average, yet perioperative care coordination gaps may limit the ability for institutions to achieve this goal. Internal review determined that increased LOS after CEA at our institution was frequently attributable to urinary retention or postoperative hypertension. We designed and implemented a quality improvement (QI) protocol aiming to better our institutional performance in postoperative LOS after CEA, consisting of 2 Plan-Do-Study-Act (PDSA) cycles.

METHODS

In the first PDSA cycle, a division-wide standardized protocol was developed by which antihypertensive medications were managed preoperatively and through postoperative day (POD) 1. This protocol included dedicated patient outreach with instructions for at-home antihypertensive management through the morning of POD 0. Second, alpha-1-blockade was administered to all male patients preoperatively. All patients receiving an elective CEA performed at our institution by vascular surgeons were included in the protocol. The primary outcome measure was defined percent failure of the LOS >1 day metric, with raw LOS as a secondary outcome measure. Process measures included adherence to the antihypertensive medication protocol and adherence to preoperative alpha-1 blockade. Balance measures included documented intraoperative hypotension and 30-day readmission. Fisher's exact test was used to evaluate relationships between preintervention and postintervention cohorts and the outcome measure. Wilcoxon rank-sum tests were used to evaluate relationships between cohorts and total LOS.

RESULTS

Baseline performance on the LOS >1 day metric after elective CEA was 58.3% in the 8 months prior to intervention, across 48 patients. Both PDSA interventions were implemented simultaneously. In the 12 months after intervention, 64 patients met protocol inclusion criteria, including 19 symptomatic patients (29.7%). Process measure success for preoperative antihypertensive regimen adherence was 89.8%. For males not chronically prescribed alpha-1 blockade preoperatively, process measure success for adherence to preoperative alpha-1 blockade was 78.8%. The intraoperative hypotension balance measure occurred in 1 patient (1.6%). Performance on the LOS >1 day outcome measure was improved to 32.8% (P = 0.01). Performance on the raw LOS outcome measure was similar between the preintervention cohort (median 2 days, interquartile range [IQR] 1-2) and postintervention cohort (median 1 day, IQR 1-2, P = 0.07). Performance on the 30-day readmission balance measure was similar between preintervention (6.3%) and postintervention cohorts (9.4%, P = 0.73).

CONCLUSIONS

The consensus-driven development and implementation of a QI protocol to reduce postoperative LOS after CEA showed promising results in our institution, with approximately 40% improvement in the primary outcome measure. Wider efforts to improve LOS after CEA should include a focus on minimization of postoperative hypertension and urinary retention.

Preoperative Anemia Is Associated With Postoperative Renal Failure After Elective Open Aortic Repair

INTRODUCTION

Preoperative anemia has been consistently shown to be a risk factor for acute kidney injury (AKI) after cardiac surgery. However, this association has not been examined in the open abdominal aortic aneurysm repair (OAR) population and is the subject of this analysis.

METHODS

Targeted Vascular Module from the American College of Surgeons National Surgical Quality Improvement Program was queried for patients undergoing OAR from 2013 to 2019. Anemia was defined according to World Health Organization Guidelines: Hematocrit<36% for women or <39% for men. Primary endpoint was 30-day AKI. Anemia's effect on AKI was determined using inverse probability weighted logistic regression.

RESULTS

There were 2275 OAR; mean age was 70.9 ± 8.2 y; 24.0% were women. Anemia was present in 498 (26.3%) patients; 165 (7.6%) had a hematocrit<33% and 8 (0.35%) had a hematocrit<24%. Differences in patient factor were nonsignificant after weighting. Any degree of postoperative AKI was more common in the anemia group (11.2% vs 5.1%; unweighted P < 0.001), as was AKI requiring hemodialysis (7.7% vs 3.2%; unweighted P < 0.001). In the weighted multivariable analysis, anemia was independently associated with postoperative AKI (odds ratio 1.51; 95% confidence interval: 1.01-2.26; P = 0.042) while controlling for age and operative factors. Patients with postoperative AKI were significantly more likely to die postoperatively than those without (26.1% vs 1.9%; <0.001).

CONCLUSIONS

Preoperative anemia was independently associated with post-OAR AKI after propensity weighting and controlling for operative factors. AKI is a major source of morbidity and mortality in these patients, and, if time permits, preoperative correction of anemia or its underlying cause should be considered in high-risk patients.

Sex-based differences in outcomes after lower extremity bypass for chronic limb-threatening ischemia

BACKGROUND AND AIMS

Lower extremity bypass surgery is an effective treatment option for patients with chronic limb-threatening ischemia (CLTI). Recent studies have suggested that sex-based differences may impact patient outcomes following lower extremity revascularization, however, results have been inconsistent.

METHODS

In this multicenter analysis, we retrospectively identified all infrainguinal bypass procedures performed for CLTI from 2002 to 2021. Patients were separated into two groups based on sex. Primary outcomes were major limb amputation and reintervention for graft patency.

RESULTS

Of 843 bypasses performed over the study period, 347 (41.2%) patients were female. Racial/ethnic distribution and medical comorbidities were similar across sex groups. Surgical indications and operative details were also similar between groups, including conduit type (49.9% autogenous), bypass target (65.4% infrageniculate), and concurrent endarterectomy (38.9%). Female and male patients had similar hospital length of stay (6 days [4-9] vs 6 days [4-9]), hospital readmission (25.6% vs 25.0%), and postoperative complications (p=NS each). Female patients had higher major amputation rates (10.1% vs 6.3%, p=0.04) after one year, whereas reintervention rates were similar between groups (26.2% vs 24.6%, p=NS). After accounting for patient factors, female sex (odds ratio [OR] 1.02 [1.00-1.04]), infrageniculate target (OR 1.02 [1.00-1.04]), and bypass for tissue loss (OR 1.02 [1.00-1.04]) were associated with major amputation after bypass (p<0.05 each).

CONCLUSIONS

Female sex is associated with a small but significant increase major amputation after lower extremity bypass surgery for CLTI, despite similar clinical presentation, medical comorbidities, and operative details. These data support the increasingly recognized sex disparities in peripheral arterial disease.

Preoperative Anemia is Associated with Poorer Postoperative Outcomes in Patients Undergoing Infrainguinal Bypass Surgery

BACKGROUND

Preoperative anemia is an important, modifiable risk factor among surgical patients. However, data are scarce on the impact of preoperative anemia on postoperative outcomes after infrainguinal bypass.

METHODS

In this multi-institutional analysis, data were retrospectively collected on all infrainguinal bypass procedures performed between 2010 and 2020. Patients were grouped by preoperative hemoglobin as per the National Cancer Institute anemia scale (mild, 10 g/dL-lower limit of normal; moderate, 8.0-9.9 g/dL; severe, 6.5-7.9 g/dL). Multivariable comparisons were performed using logistic regression analysis.

RESULTS

A total of 492 patients underwent bypass for peripheral artery disease over the 10-year study period. Median preoperative hemoglobin was 11.0 g/dL (interquartile range 9.5-12.7) and median follow-up was 1.7 years. Preoperative anemia was prevalent among bypass patients (mild 52.4% [n = 258], moderate 26.4% [n = 130], and severe 5.1% [n = 25]). Women were more likely to have moderate (49.2% [women] vs. 50.8% [men]) or severe anemia (52.0% [women] vs. 48.0% [men]) compared with normal hemoglobin (17.7% [women] vs. 82.3% [men]) (P < 0.001). Patients with preoperative anemia were more likely to present with tissue loss (22.8% [normal] vs. 47.7% [moderate] vs. 52.0% [severe], P = 0.01). Bypass target and conduit types were similar between groups. Anemic patients had longer median hospital length of stay compared with nonanemic patients (4 days [normal] vs. 5 days [mild] vs. 6 days [moderate] vs. 7 days [severe], P < 0.001). Postoperative mortality at 30 days was similar across anemia groups (2.5% [normal] vs. 4.6% [moderate] vs. 8.0% [severe], P = 0.23). On multivariable analysis, however, postoperative mortality was independently associated with severe anemia (odds ratio 7.5 [1.2-48.8], P = 0.04) and male gender (odds ratio 7.5 [1.2-26.4], P = 0.03).

CONCLUSIONS

Preoperative anemia is common among patients undergoing infrainguinal bypass surgery and is an independent risk factor for postoperative mortality. Future investigation is needed to determine whether correction of anemia improves postoperative outcomes in these high-risk patients.

Impact of Factor Xa Inhibition on Coagulation, Platelet Reactivity, and Thrombosis in Patients with Peripheral Artery Disease

BACKGROUND

The role of thrombin in vascular pathology is a focus of investigation. The incorporation of direct Factor Xa inhibition into practice patterns is based on its theoretical dual-pathway attenuation of both thrombin generation and platelet aggregation. However, quantification of the effect of direct anti-Xa medications on platelet function is not established. Thromboelastography with platelet mapping (TEG-PM) leverages dual-pathway metrics to provide comprehensive coagulation profiles. We evaluated the effects of direct oral anticoagulants (DOACs) on coagulation and platelet function profiles and correlate these data with postoperative major adverse limb events (MALEs) in patients with PAD.

METHODS

We conducted a prospective study of patients undergoing lower extremity revascularization with serial perioperative TEG-PM analysis. Patients on DOACs were compared to those not on DOACs, and stratified by concurrent mono-antiplatelet or dual-antiplatelet regimens (MAPT/DAPT). Postoperative MALE was recorded and difference in antithrombotic regimens and TEG-PM analysis compared between groups.

RESULTS

Four hundred seventy-one samples from 141 patients were analyzed. Twenty-nine point five percent were reflective of circulating DOAC therapy. Compared to MAPT alone, patients on DOAC + MAPT exhibited longer time to clot formation (R-time) [7.4 (±2.4) vs. 6.7 (±2.7); P < 0.02], but less platelet inhibition. Patients on DAPT exhibited greater platelet inhibition compared to either group [23.7 (±26.9) vs. 31.0 (±28.3) vs. 42.2 (±31.2); P < 0.01]. Patients who experienced MALE were more likely to be on DOAC therapy [43.8% vs. 22.0% P = 0.02]. Thromboelastography with platelet mapping analysis from patients who experienced MALE also demonstrated longer R-time [8.6 (±3.9 vs. 7.3 (±3.0); P = 0.05] and increased maximum clot amplitude (MA) [66.7 (±4.2) vs. 61.8 (±8.2); P = 0.001].

CONCLUSIONS

Direct oral anticoagulant therapy resulted in a prolonged R-time but had no impact on platelet inhibition. Patients who experienced MALE were more often on DOACs and demonstrated an increased R-time, but also showed greater platelet reactivity evident by increased MA, suggesting DOACs may not be effective at protecting against MALE. Further research comparing DOAC therapy to a DAPT approach may add clarity to emerging multimodal antithrombotic recommendations.

Outcomes of symptomatic penetrating aortic ulcer and intramural hematoma in the endovascular era

BACKGROUND

Although endovascular technology has resulted in a paradigm shift in treatment, medical management remains the standard of care for penetrating aortic ulcer (PAU) and intramural hematoma (IMH). This study aimed to detail the short- and long-term outcomes of symptomatic PAU/IMH.

METHODS

Institutional data on symptomatic PAU/IMH were gathered (2005-2020). The primary outcome was the composite of recurrent symptoms, radiographic progression, intervention, rupture, and death from related or unknown cause. Factors associated with the primary outcome were determined using a Fine-Gray model with death from an unrelated cause as a competing risk.

RESULTS

A total of 83 symptomatic patients treated with medical management aside from ruptures and type A dissections: 21 isolated PAU, 30 isolated IMH, and 32 IMH and PAU. Adverse outcomes included symptom recurrence in 14 (16.9%), radiographic progression to dissection or saccular aneurysm in 17 (20.5%), surgery in 20 (24.1%) (17 thoracic endovascular aortic repair, 1 endovascular aortic repair, 1 frozen elephant trunk, and 1 open repair), and rupture in 4 (4.8%). Twenty-seven patients (32.5%) died during follow-up: 6 from IMH treatment complications, 8 from an unknown cause, and 13 from other causes. The 30-day, 1-year, and 5-year cumulative incidences of the primary outcome was 26.5% (95% confidence interval [CI], 16.9%-37.0%), 44.9% (95% CI, 32.8%-56.2%), and 57.5% (95% CI, 42.4%-69.9%), respectively. IMH with PAU was associated with a significantly higher risk of the primary outcome compared with isolated IMH (subdistribution hazard ratio, 2.21; 95% CI, 1.09-4.50; P = .027) and isolated PAU (subdistribution hazard ratio, 3.58; 95% CI, 1.44-8.88; P = .006).

CONCLUSIONS

Complications from symptomatic PAU and IMH are frequent, with intervention, recurrent symptoms, radiographic progression, rupture, or death affecting 25% of patients at 30 days after diagnosis and almost one-half of patients 1 year after diagnosis. Given the high rate of adverse events in this population, investigation into a more aggressive interventional strategy may warranted, especially in patients with a combined IMH and PAU.

Atorvastatin Effect on Clopidogrel Efficacy in Patients with Peripheral Artery Disease

BACKGROUND

Both clopidogrel and atorvastatin metabolism are rooted in hepatic cytochrome p450 activation. There are published reports of atorvastatin interfering with clopidogrel metabolism by inhibiting the activation of clopidogrel. This in turn would decrease the therapeutic effect of clopidogrel potentially resulting in an increase in thrombotic events in patients who are taking both medications. The emergence of viscoelastic assays, such as Thromboelastography with platelet mapping (TEG-PM), has been utilized to identify prothrombotic states and may provide insight into a patient's microvascular coagulation profile. The aim of this prospective, observational study was to delineate the differences in platelet function between patients on clopidogrel alone versus those on clopidogrel and atorvastatin in patients that are undergoing peripheral revascularization.

METHODS

All patients undergoing revascularization between December 2020 and August 2022 were prospectively evaluated. Patients on clopidogrel and atorvastatin were compared to those on clopidogrel alone. Serial perioperative TEG-PM analysis was performed up to 6 months postoperatively and the platelet function in terms of percent inhibition was evaluated in both groups. Statistical analysis was performed using unpaired t-test to identify differences in platelet function.

RESULTS

Over the study period, a total of 182 patients were enrolled. Of this cohort 72 patients met study criteria. 87 samples from the 72 patients were analyzed. 31 (43.05%) patients were on clopidogrel alone and 41 (56.94%) were on clopidogrel and atorvastatin. Patients on clopidogrel alone showed significantly greater platelet inhibition compared to those on clopidogrel and atorvastatin [49.01% vs. 34.54%, P = 0.03]. There was no statistical difference in platelet inhibition between groups in terms of aspirin use alone versus aspirin and atorvastatin.

CONCLUSIONS

Patients on clopidogrel and atorvastatin showed significantly less platelet inhibition compared to those on clopidogrel alone, supporting the concept that atorvastatin may interfere with the therapeutic effect of clopidogrel. Patients taking atorvastatin may require an alternative antiplatelet therapy regimen that does not include clopidogrel to achieve adequate thromboprophylaxis.

Trends in Incidence of Abdominal Aortic Aneurysm Rupture, Repair, and Mortality in Nova Scotia

BACKGROUND

The purpose of this study was to examine sex-based trends in incidence of elective abdominal aortic aneurysm (AAA), ruptured AAA, ruptured AAA repair, and AAA-related mortality.

METHODS

A retrospective analysis of patients presenting with AAA from 2005 to 2015 was conducted. Rates of elective AAA repair, ruptured AAA, ruptured AAA repair, and mortality were obtained from linking provincial administrative data using medical services insurance billing number. The age-adjusted incidence of elective AAA repair, overall rate of ruptured AAA, ruptured AAA repair, and AAA-related mortality was calculated for each sex based on Canadian census estimates, adjusted to the Canadian standard population. Weighted linear regression was performed to analyze trends in incidence over time.

RESULTS

One thousand nine hundred eighty-six elective AAA repairs were identified, of which 1,098 were repaired open and 898 underwent endovascular abdominal aneurysm repair (EVAR). Five hundred and seventy ruptured AAAs were identified, of which 295 (52%) were repaired: 259 open and 36 EVAR. The proportion of ruptured AAA that was repaired did not change over time (P = 0.54). The proportion repairs performed using EVAR increased significantly in both elective (P < 0.001) and rupture repairs (P < 0.001). During the study period, 662 patients died of AAA-associated mortality. The average incidence of elective AAA repair in men was 29.3 (95% confidence interval (CI): 27.8 to 30.8) per 100,000 and decreased over time (P = 0.04), whereas the average incidence in women was 9.2 [8.3 to 10.0] and stable (P = 0.07). The incidence of open elective AAA repair was 10.5 [9.9-11.1] with a decreasing trend over time (P < 0.001) and EVAR was 9.0 (8.5-9.6) with an increasing trend over time (P < 0.001). A decreasing trend of overall ruptured AAA (5.4 [5.0-5.9], P < 0.001), ruptured AAA repair (2.9 [2.5-3.2], P = 0.02), and of AAA-related mortality (6.2 [5.8-6.8], P < 0.001) was found, with consistent trends in both sexes. The incidence of open ruptured AAA repair decreased over time (P = 0.001) whereas the incidence of ruptured EVAR remained stable (P = 0.23).

CONCLUSIONS

The incidence of elective AAA repair is decreasing in males but not females, whereas the incidence of rupture has decreased in both sexes. This has translated into reduced incidence of AAA-related mortality. Increased adoption of EVAR for ruptured AAA should continue these trends.

Increased anti-thrombotic therapy is associated with decreased major adverse limb events in patients with low wound and foot infection scores

INTRODUCTION

The optimal anti-thrombotic management of patients after lower extremity bypass has yet to be fully elucidated, in part due to significant heterogeneity in patient presentation and practice patterns. The Wound, Ischemia, and foot Infection (WIfI) score is a validated scoring system to assist in the management of patients with chronic limb threatening ischemia (CLTI). We hypothesized that performing a restriction analysis based on WIFI scores would assist in the postoperative anti-thrombotic management of patients undergoing infrainguinal bypass.

METHODS

A retrospective cohort of infrainguinal bypass procedures completed at a single hospital system between January 2018 and January 2021 was selected, and preoperative WIfI scores were extracted for each patient. Patients with either Wound scores of 2 and 3, or Ischemia Scores of 0 and 1, or Foot Infection Scores of 3 were excluded. Based on the type of anti-thrombotic regimen on discharge, demographics, comorbidities, type of bypass, 30-day rates of graft occlusion, major amputation, mortality, and major adverse limb events (MALE) were analyzed. Statistical analysis included t-tests, chi square tests, and time-to-event survival analysis.

RESULTS

230 procedures were included in the study. 69 (30.0%) patients were discharged on single antiplatelet therapy (SAPT), compared to 161 (70.0%) who were discharged on either dual antiplatelet therapy or anticoagulation (DAPT/AC). There was a higher prevalence of bypasses using prosthetic conduit in the DAPT/AC group (45.9 vs 31.8%, p = .047); no other demographic or procedural variable analyzed had any significant differences. At 30-days postoperatively, there was no significant difference in postoperative reintervention rates, however, the DAPT/AC group had significantly lower rates of mortality (1.2 vs 7.2%, p = .01), major amputation (1.2% vs 5.8%, p = .04), and MALE (3.7 vs 13.0%, p < .01). There were no significant differences in bleeding complications. Survival analysis demonstrated that MALE-free survival was higher in the DAPT/AC group compared to the SAPT group (p < .01). On Cox regression analysis, DAPT/AC was associated with significantly decreased rates of MALE + mortality (Hazard Ratio (HR) 0.20 [0.06 - 0.66]).

CONCLUSION

Lower extremity bypasses patients with low Wound and low foot Infection scores who are discharged on DAPT/AC postoperatively have a significantly higher 30-day MALE-free survival rate compared to patients discharged on SAPT; consideration could be made to preferentially discharge such post-bypass patients on DAPT/AC.

International union of angiology consensus document on vascular compression syndromes

Vascular compression syndromes (VCS) are rare diseases, but they may cause significant symptoms interfering with the quality of life (QoL) of patients who are often in their younger age. Given their infrequent occurrence, multiform clinical and anatomical presentation, and absence of dedicated guidelines from scientific societies, further knowledge of these conditions is required to investigate and treat them using modern imaging and surgical (open or endovascular) techniques. This consensus document will focus on known VCS, affecting the arterial and venous system. The position paper, written by members of International Union of Angiology (IUA) Youth Committee and senior experts, will show an overview of pathophysiology, diagnostic, and therapeutical approaches for patients with VCS. Furthermore, this document will provide also unresolved issues that require more research that need to be addressed in the future.

An interpretable machine learning model for the prevention of contrast-induced nephropathy in patients undergoing lower extremity endovascular interventions for peripheral arterial disease

BACKGROUND

Contrast-induced nephropathy (CIN) is a postprocedural complication associated with increased morbidity and mortality. An important risk factor for development of CIN is renal impairment. Identification of patients at risk for acute renal failure will allow physicians to make appropriate decisions to minimize the incidence of CIN. We developed a machine learning model to stratify risk of acute renal failure that may assist in mitigating risk for CIN in patients with peripheral artery disease (PAD) undergoing endovascular interventions.

METHODS

We utilized the American College of Surgeons National Surgical Quality Improvement Program database to extract clinical and laboratory information associated with 14,444 patients who underwent lower extremity endovascular procedures between 2011 and 2018. Using 11,604 cases from 2011 to 2017 for training and 2840 cases from 2018 for testing, we developed a random forest model to predict risk of 30-day acute renal failure following infra-inguinal endovascular procedures.

RESULTS

Eight variables were identified as contributing optimally to model predictions, the most important being diabetes, preoperative BUN, and claudication. Using these variables, the model achieved an area under the receiver-operating characteristic (AU-ROC) curve of 0.81, accuracy of 0.83, sensitivity of 0.67, and specificity of 0.74. The model performed equally well on white and nonwhite patients (Delong p-value = 0.955) and patients age < 65 and patients age ≥ 65 (Delong p-value = 0.659).

CONCLUSIONS

We develop a model that fairly and accurately stratifies 30-day acute renal failure risk in patients undergoing lower extremity endovascular procedures for PAD. This model may assist in identifying patients who may benefit from strategies to prevent CIN.

Wall shear rate and energy loss coefficient measures using conventional Doppler ultrasound do not predict carotid plaque progression

Background: The rate of carotid plaque progression is believed to be related to blood flow hemodynamics and shear stress. Our objective was to determine if wall shear rate (WSR) and the energy loss coefficient (ELC) measured by Doppler ultrasound could predict atherosclerotic carotid disease progression. Patients and methods: Patients at a large tertiary center with an initial ultrasound between 2016 and 2018 with a significant carotid plaque were included if they had at least one 6 months follow-up comparative study. Stenosis progression was assessed according to the NASCET (The North American Symptomatic Carotid Endarterectomy Trial) percentage criterion. Results: The average annual progression rate for the 74 plaques included was 5.7% NASCET per year. We identified 18 plaques with ≥10% NASCET progression and 56 plaques without significant progression <10% NASCET. Among the plaques with progression, only four plaques had progression greater than 20% NASCET. Median WSR was 6266 s^-1 [5813-8974] in plaques with progression and 6564 s^-1 [5285-8766] in stable plaques (p=0.643). Median ELC was 3.86 m² [2.78-5.53] in plaque with progression and 4.32 m² [3.42-6.81] in stable plaques (p=0.296). Conclusions: Although it is a widely accepted hypothesis that shear stress and hemodynamics of the carotid bifurcation contribute to plaque progression, we found that WSR and ELC estimated by Doppler ultrasound do not reliably predict atherosclerotic plaque progression in the carotid artery. Other ultrasound modalities, such as 3D imaging, may be used to assess the influence of plaque geometry and hemodynamics in plaque progression.

Reassuring Intraoperative Parameters Do Not Obviate the Need for Infrainguinal Bypass Completion Angiograms

OBJECTIVE

To determine if routine completion angiography for lower extremity bypasses using vein conduit results in lower rates of postoperative bypass occlusion.

SUMMARY OF BACKGROUND DATA

With the increasing availability of on-table angiography and significant advancements in endovascular techniques, some operators routinely perform completion angiograms. The effect of this surgical paradigm has yet to be rigorously compared to the more widespread selective use of completion imaging in the modern era.

METHODS

This retrospective cohort study included infrainguinal arterial bypass procedures utilizing vein conduit completed at a single hospital system from 2001 to 2018 and compared postoperative outcomes between bypasses that underwent routine completion angiography versus selective completion angiography. Notably, any bypasses that underwent completion angiography due to intraoperative concerns were excluded from this analysis.

RESULTS

666 bypasses that were performed in 589 patients met inclusion criteria. 126 (16.9%) bypasses were classified into the routine completion angiogram group compared to 540 (81.0%) into the selective completion angiogram group. Patients who underwent routine completion angiograms had a rate of intraoperative reintervention of 22.2%. The routine angiogram group had lower rates of reintervention (3.9% vs 10.0%, P = 0.03) and graft occlusion (2.3% vs 9.2%, P = 0.01) at 1-month postoperatively.

CONCLUSION

Lower extremity bypasses using vein conduit that undergo routine completion angiography are associated with lower rates of graft occlusion at 30-days postoperatively. Completion angiography should thus be routinely performed in infrainguinal bypasses that utilize venous conduit.

Factors Influencing Hospital Readmission after Lower Extremity Bypass for Chronic Limb-Threatening Ischemia

Objectives: Unplanned hospital readmission is a leading source of hospital resource expenditure, and preventing readmission may improve both patient quality of life and healthcare costs. The factors influencing hospital readmission after lower extremity bypass (LEB) for chronic limb-threatening ischemia (CLTI) remain incompletely investigated. Methods: A regional, multi-institutional database was retrospectively reviewed for all patients who underwent LEB for CLTI between 1995 to 2020. The primary outcome was unplanned hospital readmission up to 30 days following bypass. Results: A total of 1315 patients underwent LEB across all institutions, of whom 843 (64.1%) underwent bypass for CLTI. The 30-day hospital readmission rate was 25.3%, and the leading causes of readmission were wound-related complications (51.6%). There was no difference in age, sex, or race between readmitted and non-readmitted patients. Conduit type and bypass target were also similar between groups. Readmitted patients more frequently underwent LEB for tissue loss (58.2% vs 50.2%, P = 0.042). On multivariable analysis, wound infection (odds ratio [OR] 9.1, 95% confidence interval [CI] 6.2-13.2, P < 0.001) and non-infectious wound complications (OR 2.0, 95% CI 1.0-3.9, P = 0.041) were independently associated with hospital readmission. Factors not associated with hospital readmission included patient age, conduit type, distal bypass target, and other medical comorbidities. Conclusions: One quarter of patients are readmitted within 30 days following lower extremity bypass for chronic limb-threatening ischemia. Efforts to mitigate wound infection and non-infectious wound complications may decrease rates of unplanned hospital readmission.

Effect of after-hours presentation in ruptured abdominal aortic aneurysm

OBJECTIVE

Ruptured abdominal aortic aneurysms (RAAAs) are surgical emergencies that require immediate and expert treatment. It has been unclear whether presentation during evenings and weekends, when "on call" teams are primarily responsible for patient care, is associated with worse outcomes. Our objective was to evaluate the outcomes of patients presenting with RAAAs after-hours vs during the workday.

METHODS

A retrospective cohort study of all RAAAs in Nova Scotia between 2005 and 2015 was performed through linkage of administrative databases. Patients who had presented to the hospital with RAAAs during the workday (Monday through Friday, 6 am to 6 pm) were compared with those who had presented after-hours (6 pm to 6 am during the week and on weekends). The baseline and operative characteristics were identified for all patients through the available databases and a review of the medical records. Mortality before surgery, 30-day mortality, and operative mortality were compared between groups using multivariable logistic regression, adjusting for factors clinically significant on univariable analysis.

RESULTS

A total of 390 patients with RAAAs were identified from 2005 to 2015, of whom 205 (53%) had presented during the workday and 185 (47%) after-hours. The overall chance of survival (OCS) was 45% overall, 49% if admitted to hospital, and 64% if surgery had been performed. During the workday, the OCS was 43% overall, 48% if admitted to hospital, and 67% if surgery had been performed. After-hours, the OCS was 46% overall, 49% if admitted to hospital, and 61% if surgery had been performed. Mortality before surgery was increased for patients who had presented to the hospital during the workday compared with after-hours (36% vs 26%; P = .04). The 30-day mortality (57% vs 54%; P = .62), rates of operative management (63% vs 72%; P = .06), and operative mortality (33% vs 39%; P = .33) were similar between the workday and after-hours groups (57% vs 54%; P = .06). After adjusting for significant clinical variables, the patients who had presented with RAAAs after-hours had had a similar odds of dying before surgery (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.41-1.03), operative management (OR, 1.47; 95% CI, 0.93-2.31), 30-day mortality (OR, 0.98; 95% CI, 0.63-1.51), and operative mortality (OR, 1.33; 95% CI, 0.78-2.26). In the subgroup of patients presenting to a hospital with endovascular capabilities, patients presenting after-hours had had similar odds of 30-day mortality (OR, 1.07; 95% CI, 0.57-2.02), and operative mortality (OR, 1.14; 95% CI, 0.58-2.23).

CONCLUSIONS

We found that patients presenting to the hospital with RAAAs after-hours did not have increased adjusted odds of mortality before surgery, operative management, 30-day mortality, or operative mortality.

Celiac Artery Coverage During TEVAR for Dissection and Acute Aortic Injury is Not Associated with Worse Outcomes

BACKGROUND

Studies have previously identified increased morbidity and mortality with celiac artery coverage during thoracic endovascular aortic repair (TEVAR) for aneurysmal disease. This study aimed to delineate the risks associated with celiac artery coverage in all patients undergoing TEVAR for dissection, trauma, or aneurysmal disease.

METHODS

Using the Vascular Quality Initiative database, we identified all patients undergoing TEVAR from 2012 to 2020 and categorized them based on the underlying pathology (aneurysm, dissection, or acute/trauma). Patients were excluded if their endograft was deployed distal to aortic zone 6 or if they had any preoperative/operative celiac revascularization procedure. Univariate, regression, and Kaplan-Meier analysis were performed for all 3 groups, focusing on postoperative complications and survival.

RESULTS

There were 8,265 patients who underwent TEVAR over the 8-year study period with 142 (1.7%) having celiac artery coverage during their index procedure. Of those patients, the celiac artery was covered during TEVAR in 1.2% of patients with dissection, 1.3% with aneurysm, and 0.7% with trauma. On unadjusted analysis, celiac artery coverage in TEVAR for aneurysmal disease was associated with increased in-hospital mortality (16% vs. 5%, P < 0.001), 30-day mortality (33% vs. 23%, P = 0.029), any postoperative complication (excluding death) (42% vs. 25%, P < 0.001), and postoperative bowel complication (3% vs. 0.7%, P = 0.003). There were no differences in outcomes for patients treated with celiac coverage versus those without celiac coverage during TEVAR for dissection or trauma on univariate analysis. After risk adjustment, celiac artery coverage remained predictive of worse postoperative outcomes in patients with aneurysmal disease: in-hospital mortality (odds ratio [OR] = 3.6, confidence interval [CI] 1.8-6.9), 30-day death (OR = 1.6, CI 1.0-2.4), any postoperative complication (OR 2.2, CI 1.4-3.5), and bowel-specific postoperative complication (3.3, CI 1.0-10.8). There were no differences in patient outcomes for those treated with celiac coverage versus those without celiac coverage during TEVAR for dissection or trauma on multivariate analysis. Kaplan-Meier curves show a significant difference in overall survival based on pathology, specifically lower survival rates for patients with celiac coverage treated for aneurysmal disease. Cox regression analysis showed that celiac artery coverage for aneurysmal disease was associated with significantly increased hazard ratio affecting overall survival (hazard ratio = 2.6, P < 0.001), but there was no impact on survival in patients who underwent TEVAR with celiac coverage for dissection or trauma.

CONCLUSIONS

Celiac artery coverage for patients with aneurysmal disease was correlated with a significant increase in postoperative morbidity, mortality, and lowers overall survival. However, for patients with dissection or acute/traumatic aortic pathology, celiac artery coverage does not portend worse outcomes.

Transcatheter Arterialization of Deep Veins in Chronic Limb-Threatening Ischemia

BACKGROUND

Approximately 20% of patients with chronic limb-threatening ischemia have no revascularization options, leading to above-ankle amputation. Transcatheter arterialization of the deep veins is a percutaneous approach that creates an artery-to-vein connection for delivery of oxygenated blood by means of the venous system to the ischemic foot to prevent amputation.

METHODS

We conducted a prospective, single-group, multicenter study to evaluate the effect of transcatheter arterialization of the deep veins in patients with nonhealing ulcers and no surgical or endovascular revascularization treatment options. The composite primary end point was amputation-free survival (defined as freedom from above-ankle amputation or death from any cause) at 6 months, as compared with a performance goal of 54%. Secondary end points included limb salvage, wound healing, and technical success of the procedure.

RESULTS

We enrolled 105 patients who had chronic limb-threatening ischemia and were of a median age of 70 years (interquartile range, 38 to 89). Of the patients enrolled, 33 (31.4%) were women and 45 (42.8%) were Black, Hispanic, or Latino. Transcatheter arterialization of the deep veins was performed successfully in 104 patients (99.0%). At 6 months, 66.1% of the patients had amputation-free survival. According to Bayesian analysis, the posterior probability that amputation-free survival at 6 months exceeded a performance goal of 54% was 0.993, which exceeded the prespecified threshold of 0.977. Limb salvage (avoidance of above-ankle amputation) was attained in 67 patients (76.0% by Kaplan-Meier analysis). Wounds were completely healed in 16 of 63 patients (25%) and were in the process of healing in 32 of 63 patients (51%). No unanticipated device-related adverse events were reported.

CONCLUSIONS

We found that transcatheter arterialization of the deep veins was safe and could be performed successfully in patients with chronic limb-threatening ischemia and no conventional surgical or endovascular revascularization treatment options. (Funded by LimFlow; PROMISE II study ClinicalTrials.gov number, NCT03970538.).

Routine Completion Angiography For Infrainguinal Bypasses Using Prosthetic Conduit: No Effect On Postoperative Patency

INTRODUCTION

Recent studies have demonstrated increased postoperative patency with the use of routine completion angiography for bypass using venous conduit. Compared to vein conduits however, prosthetic conduits are less plagued by technical issues such as unlysed valves or arteriovenous fistulae. The effect of routine completion angiography on bypass patency in prosthetic bypasses has yet to be compared to the more traditional selective use of completion imaging.

METHODS

A retrospective review of all infrainguinal bypass procedures using prosthetic conduit completed at a single hospital system from 2001 to 2018 was performed. Demographics, comorbidities, intraoperative reintervention rates and 30-day rates of graft thrombosis were analyzed. Statistical analysis included t-tests, chi square tests and cox regression.

RESULTS

Four hundred and ninety-eight bypasses that were performed in 426 patients met inclusion criteria. Fifty-six (11.2%) bypasses were classified into the routine completion angiogram group compared to 442 (88.8%) into the no completion angiogram group. Patients who underwent routine completion angiograms had a rate of intraoperative reintervention of 21.4%. When comparing bypasses that underwent routine completion angiography versus no completion angiography, there were no significant differences in rates of reintervention (3.5% vs. 4.5%, P=0.74) or graft occlusion (3.5% vs. 4.7%, P=0.69) at 30-days postoperatively.

CONCLUSION

Almost one-quarter of lower extremity bypasses using prosthetic conduit that undergo routine completion angiography undergo post-angiogram bypass revision, however this is not associated with an increased graft patency at 30-days postoperatively.

Use of Thromboelastography with Platelet Mapping to Identify Prothrombotic Coagulation Profiles in Patients with History of Cardiac Intervention Undergoing Lower Extremity Revascularization

BACKGROUND

Patients with concomitant coronary and peripheral artery disease (CAD and PAD) are at significant risk for major adverse limb events (MALEs). Prevention of thrombosis in this population is of paramount importance. Identifying prothrombotic coagulation profiles in this cohort may facilitate targeted thromboprophylaxis. We compared coagulation profiles of those with CAD and PAD to those with PAD alone during the perioperative period of lower extremity revascularization.

STUDY DESIGN

Patients undergoing lower extremity revascularization underwent thromboelastography-platelet mapping (TEG-PM) analysis preoperatively and at serial intervals for up to 6 months. Coagulation profiles of patients with significant CAD (defined as history of coronary artery bypass graft or percutaneous coronary intervention) and PAD were compared with those with PAD alone. MALE in the postoperative period was recorded.

RESULTS

Four hundred seventy-seven TEG-PM samples from 114 patients were analyzed; 28.1% had a history of significant CAD. The incidence of atrial fibrillation was higher in this group. The significant CAD group had lower ADP-platelet inhibition, higher ADP-platelet aggregation, and greater maximum clot strength compared with patients with PAD alone. Patients with significant CAD were more frequently on full-dose anticoagulation, but less frequently on dual antiplatelet therapy; 28.1% of patients with significant CAD developed postoperative MALE compared with 22.9% of patients with PAD alone (p = 0.40). For both groups, patients who developed postoperative MALE demonstrated greater ADP-platelet aggregation and lower ADP-platelet inhibition.

CONCLUSIONS

Patients with a history of significant CAD undergoing lower extremity revascularization demonstrated prothrombotic TEG-PM profiles, less frequent use of dual antiplatelet therapy, and greater rates of full-dose anticoagulation. Decreased platelet inhibition was also associated with postoperative MALE. This study underscores the potential utility of viscoelastic assays for coagulation profiling in complex cardiovascular patients.

Factors associated with successful median arcuate ligament release in an international, multi-institutional cohort

OBJECTIVE

Prior research on median arcuate ligament syndrome has been limited to institutional case series, making the optimal approach to median arcuate ligament release (MALR) and resulting outcomes unclear. In the present study, we compared the outcomes of different approaches to MALR and determined the predictors of long-term treatment failure.

METHODS

The Vascular Low Frequency Disease Consortium is an international, multi-institutional research consortium. Data on open, laparoscopic, and robotic MALR performed from 2000 to 2020 were gathered. The primary outcome was treatment failure, defined as no improvement in median arcuate ligament syndrome symptoms after MALR or symptom recurrence between MALR and the last clinical follow-up.

RESULTS

For 516 patients treated at 24 institutions, open, laparoscopic, and robotic MALR had been performed in 227 (44.0%), 235 (45.5%), and 54 (10.5%) patients, respectively. Perioperative complications (ileus, cardiac, and wound complications; readmissions; unplanned procedures) occurred in 19.2% (open, 30.0%; laparoscopic, 8.9%; robotic, 18.5%; P < .001). The median follow-up was 1.59 years (interquartile range, 0.38-4.35 years). For the 488 patients with follow-up data available, 287 (58.8%) had had full relief, 119 (24.4%) had had partial relief, and 82 (16.8%) had derived no benefit from MALR. The 1- and 3-year freedom from treatment failure for the overall cohort was 63.8% (95% confidence interval [CI], 59.0%-68.3%) and 51.9% (95% CI, 46.1%-57.3%), respectively. The factors associated with an increased hazard of treatment failure on multivariable analysis included robotic MALR (hazard ratio [HR], 1.73; 95% CI, 1.16-2.59; P = .007), a history of gastroparesis (HR, 1.83; 95% CI, 1.09-3.09; P = .023), abdominal cancer (HR, 10.3; 95% CI, 3.06-34.6; P < .001), dysphagia and/or odynophagia (HR, 2.44; 95% CI, 1.27-4.69; P = .008), no relief from a celiac plexus block (HR, 2.18; 95% CI, 1.00-4.72; P = .049), and an increasing number of preoperative pain locations (HR, 1.12 per location; 95% CI, 1.00-1.25; P = .042). The factors associated with a lower hazard included increasing age (HR, 0.99 per increasing year; 95% CI, 0.98-1.0; P = .012) and an increasing number of preoperative diagnostic gastrointestinal studies (HR, 0.84 per study; 95% CI, 0.74-0.96; P = .012) Open and laparoscopic MALR resulted in similar long-term freedom from treatment failure. No radiographic parameters were associated with differences in treatment failure.

CONCLUSIONS

No difference was found in long-term failure after open vs laparoscopic MALR; however, open release was associated with higher perioperative morbidity. These results support the use of a preoperative celiac plexus block to aid in patient selection. Operative candidates for MALR should be counseled regarding the factors associated with treatment failure and the relatively high overall rate of treatment failure.

Predicting Arterial Thrombotic Events Following Peripheral Revascularization Using Objective Viscoelastic Data

Background Peripheral artery disease is endemic in our globally aging population, with >200 million affected worldwide. Graft/stent thrombosis after revascularization is common and frequently results in amputation, major adverse cardiovascular events, and cardiovascular mortality. Optimizing medications to decrease thrombosis is of paramount importance; however, limited guidance exists on how to use and monitor antithrombotic therapy in this heterogeneous population. Thromboelastography with platelet mapping (TEG-PM) provides comprehensive coagulation metrics and may be integral to the next stage of patient-centered thrombophrophylaxis. This prospective study aimed to determine if TEG-PM could predict subacute graft/stent thrombosis following lower extremity revascularization, and if objective cut point values could be established to identify those high-risk patients. Methods and Results We conducted a single-center prospective observational study of patients undergoing lower extremity revascularization. Patients were followed up for the composite end point postoperative graft/stent thrombosis at 1 year. TEG-PM analysis of the time point before thrombosis in the event group was compared with the last postoperative visit in the nonevent group. Cox proportional hazards analysis examined the association of TEG-PM metrics to thrombosis. Cut point analysis explored the predictive capacity of TEG-PM metrics for those at high risk. A total of 162 patients were analyzed, of whom 30 (18.5%) experienced graft/stent thrombosis. Patients with thrombosis had significantly greater platelet aggregation (79.7±15.7 versus 58.5±26.4) and lower platelet inhibition (20.7±15.6% versus 41.1±26.6%) (all P<0.01). Cox proportional hazards analysis revealed that for every 1% increase in platelet aggregation, the hazard of experiencing an event during the study period increased by 5% (hazard ratio, 1.05 [95% CI, 1.02-1.07]; P<0.01). An optimal cut point of >70.8% platelet aggregation and/or <29.2% platelet inhibition identifies those at high risk of thrombosis with 87% sensitivity and 70% to 71% specificity. Conclusions Among patients undergoing lower extremity revascularization, increased platelet reactivity was predictive of subacute postoperative graft/stent thrombosis. On the basis of the cut points of >70.8% platelet aggregation and <29.2% platelet inhibition, consideration of an alternative or augmented antithrombotic regimen for high-risk patients may decrease the risk of postoperative thrombotic events.

Variability of antiplatelet response in patients with peripheral artery disease

OBJECTIVE

Antiplatelet therapy has been a pillar of management for peripheral artery disease (PAD). However, a significant subset of patients with PAD will be resistant to certain antiplatelet medications and, therefore, have an increased risk of graft and/or stent thrombosis unknown to the surgeon. At present, no point-of-care testing to identity which patients will experience benefit from these medications has been incorporated into the treatment guidelines. Thromboelastography with platelet mapping affords an opportunity to evaluate real-time coagulation dynamics and platelet function. In the present prospective, observational study, we aimed to delineate the variation in response to antiplatelet therapy in patients with PAD undergoing revascularization.

METHODS

All patients who were undergoing named vessel revascularization during December 2020 through April 2022 were prospectively enrolled. Platelet mapping assays were performed in three clinical phases: preoperative, postoperative inpatient, and postoperative outpatient. The distribution of platelet reactivity within patients receiving mono- vs dual antiplatelet therapy was assessed, and a between-group inferential analysis was performed. The effect of comorbidities and intervention subtype on platelet inhibition was also analyzed.

RESULTS

A total of 521 platelet mapping samples from 143 individual patients were analyzed using thromboelastography with platelet mapping. We found wide variability in the distribution of platelet inhibition, with a range of 0 to 100 and an interquartile range of 37.6. Although platelet inhibition with clopidogrel 75 mg was higher on average (44.8 ± 30.2) than that with aspirin 81 mg (24.6 ± 23.7) or aspirin 325 mg (27.1 ± 26.4; P = .001), clopidogrel at 75 mg demonstrated the highest variability in response.

CONCLUSIONS

These data have demonstrated significant variability in the response to both mono- and dual antiplatelet therapy in PAD patients undergoing lower extremity revascularization. Future research on the effect of this variability in response on the clinical outcomes could provide invaluable understanding of the perioperative thrombotic risk.

Microvascular assessment of fascio-cutaneous flaps by ultrasound: A large animal study

Objectives: Blood perfusion quality of a flap is the main prognostic factor for success. Microvascular evaluation remains mostly inaccessible. We aimed to evaluate the microflow imaging mode, MV-Flow, in assessing flap microvascularization in a pig model of the fascio-cutaneous flap. Methods: On five pigs, bilateral saphenous fascio-cutaneous flaps were procured on the superficial femoral vessels. A conventional ultrasound evaluation in pulsed Doppler and color Doppler was conducted on the ten flaps allowing for the calculation of the saphenous artery flow rate. The MV-Flow mode was then applied: for qualitative analysis, with identification of saphenous artery collaterals; then quantitative, with repeated measurements of the Vascularity Index (VI), percentage of pixels where flow is detected relative to the total ultrasound view area. The measurements were then repeated after increasing arterial flow by clamping the distal femoral artery. Results: The MV-Flow mode allowed a better follow-up of the saphenous artery's collaterals and detected microflows not seen with the color Doppler. The VI was correlated to the saphenous artery flow rate (Spearman rho of 0.64; p = 0.002) and allowed to monitor the flap perfusion variations. Conclusion: Ultrasound imaging of microvascularization by MV-Flow mode and its quantification by VI provides valuable information in evaluating the microvascularization of flaps.

Impact of socioeconomic disparities on major lower extremity revascularization complications

INTRODUCTION

Low socioeconomic status (SES), distance lived from hospital, and insurance status are well documented in the literature to increase the risk of post-operative morbidity and mortality for some disease processes however there is a paucity of data regarding how this association impacts patients with peripheral artery disease (PAD). This study aimed to evaluate if SES, distance lived from hospital, and insurance status increased the risk of developing major graft failure in patients undergoing revascularization procedures for symptomatic PAD in a prospective, observation study.

METHODS

In this prospective, observational study, all patients undergoing lower extremity revascularization (endovascular or open) were included from December 2020 to February 2022. Demographic factors, insurance status, operative details, and median income and distance from hospital were documented through chart review. Complications were defined as thrombosis/occlusion of the revascularized vessel or bypass graft or infection of the distal wound or surgical incision wound. Univariate and multivariate analysis were performed comparing patients that developed complications and those that did not. This project was undertaken at the Massachusetts General Hospital and was governed by the Institutional Review Board (IRB: 2020P000263) all patients agreed to participation via informed written consent prior to enrollment in the study.

RESULTS

A total of 108 patients were enrolled in the study of which 94 underwent successful revascularization procedures. Of those 94 patients, 38 (40.4%) underwent open bypass, 39 (41.5%) underwent endovascular revascularization, and 17 (18.1%) underwent a hybrid approach. There were no significant differences in post-operative outcomes between operative approaches. Twenty-five patients (28.7%) experienced major revascularization complications as defined as re-occlusion of the treated vessel/thrombosis of the bypass graft (n = 13) or development of post-operative infection (n = 12). There was no significant difference in median income ($75,295 vs $87,757, p = NS), distance lived from hospital, (27.4 miles vs. 29.7 miles, p = NS), or type of insurance (private 24% vs 26%, government 76% vs 73%, p = NS between patients that experienced complications versus those that did not have complications. These findings suggest the risk of major graft failure is independent of a patient's socioeconomic status, distance lived from hospital, or insurance type in patients undergoing revascularization procedures for PAD.

CONCLUSION

While socioeconomic factors impact access to and have a known association with negative outcomes, complications in patients with PAD appear to be independent of these factors. To mitigate the negative outcomes in patients with peripheral artery disease, a focus should be on patient risk factors and modifiable medical factors that contribute to adverse outcomes.

Identifying Sex Dimorphism in Peripheral Artery Disease with Platelet Mapping

INTRODUCTION

Clinical outcomes in women with PAD after revascularization procedures are worse as compared to men, yet there is little in the existing literature as why this may be the case. Platelet Mapping is an emerging point-of-care viscoelastic technology that measures the comprehensive properties of a blood clot, including fibrin-platelet interactions. This prospective observational study aimed to characterize the clinical and Platelet Mapping profiles of female and male patients undergoing lower extremity revascularization, and to correlate Platelet Mapping distribution to thrombotic potential.

METHODS

All patients with a diagnosis of PAD undergoing named vessel open or endovascular revascularization to reestablish either inflow, outflow, or both, during December 2020 and January 2022 were prospectively included. Patients were followed clinically for thrombosis for up to one year. Platelet Mapping assays were performed in three clinical phases: preoperative, postoperative inpatient and postoperative outpatient. Inferential analysis between female and male patient was performed. The quartile distribution of Platelet Mapping metrics associated with thrombosis was used to infer to thrombotic potential.

RESULTS

One hundred and seven patients were enrolled, of which thirty-seven (34.6%) were female. Female patients had significantly lower rates of uncontrolled diabetes [2.7% vs. 18.6%], hypertension requiring combination therapy [37.8% vs. 58.6%], CKD [27.0% vs. 51.4%], CAD [29.7% vs. 57.1%] and MI [16.2% vs. 35.7%], (all p<0.05). Platelet reactivity was significantly higher in female patients with greater platelet aggregation [75.9±23.3 vs. 63.5±28.8] and lower platelet inhibition [23.8±23.4 vs. 36.8±28.9] (all p<0.01). This trend was consistent over time when stratified by the postoperative inpatient and postoperative outpatient clinical phases. There was no statistically discernable difference in the use of antiplatelet therapy between groups, yet female patients continued to exhibit greater platelet reactivity when analyzed by type of pharmacologic regimen [platelet aggregation on monoantiplatelet therapy: 80.6±21.0 in women vs. 69.4±25.0 in men; platelet aggregation on dual antiplatelet therapy: 67.9±23.8 in women vs. 44.8±31.8 in men] (all p<0.01). 21 patients experienced postoperative graft/stent thrombosis within the study period. In relation to the overall study population, patients with thrombosis had Platelet Mapping metrics above the 50^th percentile of overall platelet aggregation distribution.

CONCLUSION

There is a growing appreciation for the differences in etiology, disease progression and outcomes of cardiovascular conditions as they relate to sex. In this cohort, traditional cardiovascular risk factors were in lower prevalence in female patients. Platelet reactivity was found to be higher across clinical phases and antiplatelet regimens. High platelet reactivity was also associated with an increased incidence of thrombosis after lower extremity revascuarlization. These hypothesis-generating findings provide the basis for further exploration of sex-specific coagulation profiling in PAD patients.

Outcomes of Femoropopliteal Bypass for Lifestyle-Limiting Claudication in the Endovascular Era

INTRODUCTION

Outcomes after femoropopliteal bypass for intermittent claudication (IC) remain unclear in the endovascular era.

METHODS

A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures performed between 1995 and 2020. Demographics, operative details, and outcomes were documented. A statistical analysis included Kaplan-Meier curves and Cox proportional hazards ratios (HR).

RESULTS

A total of 282 patients underwent femoropopliteal bypass surgery for IC. Median age was 68 y (interquartile range, 61-73 y). Bypass conduits included great saphenous vein (GSV) (48.2%), prosthetic grafts (48.9%), and non-GSV autogenous grafts (2.8%). Distal bypass target was above-knee in 62.1% and below-knee in 37.9% of patients. The most common postoperative complications were wound infections (14.2%) followed by unplanned 30-d hospital readmissions (12.4%). Mortality rates were low at 0.4% (30 d) and 3.2% (1 y). Five-year primary patency rates trended highest for claudicants undergoing above-knee bypass with GSV conduit (log-rank P = 0.065). Five-year amputation-free survival rates were highest using GSV conduit regardless of distal bypass target (log-rank P = 0.017). On a multivariable analysis, age (HR 1.02 [1.00-1.04], P = 0.023) and active smoking (HR 1.48 [1.06-2.06], P = 0.021) were identified as risk factors for diminished primary graft patency. Risk factors for amputation-free survival included age (HR 1.03 [1.01-1.05], P < 0.001) and GSV conduit type (HR 0.65 [0.46-0.90], P = 0.011).

CONCLUSIONS

Femoropopliteal bypass among claudicants is associated with high rates of wound infection and hospital readmission. Active smoking portends worse outcomes in this population. These data may inform clinical decision-making regarding surgical intervention for claudication in the endovascular era.