Improving follow-up of incomplete lower extremity venous duplex ultrasound examinations performed for deep and superficial vein thromboses

OBJECTIVE

A lower extremity venous duplex ultrasound (LEVDUS) examination is the standard diagnostic test to evaluate patients for lower extremity deep vein thrombosis (DVT). However, some studies will be incomplete for a variety of reasons, including patient-related factors such as pain, edema, a large leg circumference, or the presence of overlying bandages or orthopedic devices. We previously reported that the frequency of obtaining a follow-up examination after an incomplete and negative (I/N) LEVDUS examination was low but that the rates of DVT found on the follow-up studies of initially I/N LEVDUS studies were similar to the rates of DVT found with initially complete LEVDUS examinations. Therefore, we recommended process improvements to increase follow-up LEVDUS studies after an I/N LEVDUS examination. In the present study, we have described the results of appending a recommendation to obtain a follow-up LEVDUS study to preliminary and final reports of I/N LEVDUS.

METHODS

Starting in January 2019 through December 2019, a recommendation to obtain a repeat LEVDUS examination after an I/N study was appended to the preliminary and final reports of all I/N LEVDUS examination of patients who did not, otherwise, have an indication for anticoagulation (group 2). The patients were identified on an ongoing basis through the study period and entered into an Excel database (Microsoft Corp, Redmond, Wash). Group 2 was compared with a previously reported historic control cohort of patients identified from January 2017 to December 2017 (group 1). We compared groups 1 and 2 with respect to the frequency of the repeat studies performed within 4 weeks after an I/N LEVDUS examination and the DVT rates found from the follow-up LEVDUS examinations after an I/N LEVDUS study.

RESULTS

Of the patients in groups 1 and 2, 187 and 229 had had I/N LEVDUS examinations, with 28% and 40.2% of group 1 and 2 studies having follow-up LEVDUS examinations (P < .01). Previously unidentified lower extremity thrombi were discovered in 21% of the group 2 follow-up examinations. Also, the rate of new thrombi detected was not different between groups 2 and 1 (historic controls; DVT, 14.3% vs 18.5% [P = .25]; SVT, 6.3% vs 3.3% [P = .15]). A definitive finding of either positive or negative for DVT and SVT with a complete examination in 50% of the group 2 patients with follow-up examinations.

CONCLUSIONS

A recommendation to obtain a follow-up examination appended to the preliminary and final I/N LEVDUS reports was associated with an increased rate of follow-up examinations, which revealed many previously undetected DVTs and SVTs or had allowed for definitive exclusion of DVT.

Peak systolic velocity and color aliasing are important in the development of duplex ultrasound criteria for external carotid artery stenosis

OBJECTIVE

The external carotid artery (ECA) serves as a major collateral pathway for ophthalmic and cerebral artery blood supply. It is routinely examined as part of carotid duplex ultrasound, but criteria for determining ECA stenosis are poorly characterized and typically extrapolated from internal carotid artery data. This is despite the fact that the ECA is smaller in diameter, with a higher resistance and lower volume flow pattern. We hypothesized that using the cutoff of a peak systolic velocity (PSV) ≥125 cm/s, extrapolated from internal carotid artery data, will overestimate the prevalence of ≥50% ECA stenosis and aimed to determine a more appropriate criterion.

METHODS

From December 2016 to July 2017, consecutive carotid duplex ultrasound studies performed in our university hospital Intersocietal Accreditation Commission-accredited vascular laboratory were prospectively identified and categorized with respect to prevalence and distribution of ECA PSVs and color aliasing, an indication of turbulent flow or flow acceleration. Presence of color aliasing was determined by two individual reviewers and agreement assessed by Cohen κ coefficient. ECA stenosis was calculated by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method in patients with computed tomography angiography (CTA) performed within 3 months of carotid duplex ultrasound without an intervening intervention. Receiver operating characteristic analysis was performed to identify best criteria for determining ≥50% ECA stenosis.

RESULTS

There were 1324 ECAs from 662 patients analyzed; 174 patients had a total of 252 ECAs with PSV ≥125 cm/s (19% of the total sample). Of those ECAs with PSVs ≥125 cm/s, 30.5% were between 125 and 149 cm/s, 22.2% were between 150 and 174 cm/s, 13.1% were between 175 and 199 cm/s, and 34.1% were ≥200 cm/s. There were 341 ECAs that were analyzed for the presence of color aliasing. In 86 ECAs with PSV ≥200 cm/s, 58.1% had color aliasing, whereas in 255 ECAs with PSV <200 cm/s, only 19.2% had color aliasing (P = .0001). There were 325 CTA studies reviewed and assessed for the presence of a ≥50% ECA stenosis as determined by CTA. Overall, the combination of an ECA PSV ≥200 cm/s with the presence of color aliasing provided the highest combination of sensitivity (90%), specificity (96%), positive predictive value (83%), and negative predictive value (98%) and the greatest area under the curve of 0.971 for determining the presence of a ≥50% ECA stenosis based on CTA.

CONCLUSIONS

A PSV ≥125 cm/s alone probably overestimates the prevalence of ≥50% ECA stenosis. A PSV ≥200 cm/s combined with color aliasing is highly predictive of >50% ECA stenosis based on correlation with CTA.

The efficacy and safety of a catheter removal only strategy for the treatment of PICC line thrombosis versus standard of care anticoagulation: a retrospective review

Peripherally-inserted central catheters (PICCs) are commonly used during hospitalization. Unfortunately, their use can be complicated by catheter-related thrombosis (CRT). Current guidelines recommend 3-6 months of anticoagulation for patients with CRT after catheter removal. This recommendation is based on extrapolation of data on lower extremity thrombosis, as data is lacking regarding the efficacy and safety of more specific management strategies. Many providers feel catheter removal alone is a reasonable treatment option, particularly for patients at risk for bleeding. We performed a retrospective analysis of hospitalized adult patients diagnosed with CRT at our center. We determined rates of progressive thrombosis and bleeding in cohorts of patients who underwent catheter removal vs those who had catheters removed and received anticoagulation. Among 83 total patients, 62 were treated with PICC removal alone, while 21 underwent PICC removal followed by therapeutic anticoagulation. Patients treated with PICC removal alone were more likely to have hematologic malignancy, receive chemotherapy, develop thrombocytopenia, and have brachial vein thrombosis. No patients in the PICC removal plus anticoagulation arm developed progressive thrombosis, while 6.4% of patients treated with catheter removal alone developed a secondary VTE event, including one PE, three DVTs, and five patients (8%) who developed progressive symptoms leading to initiation of anticoagulation. Major bleeding was significantly more common in the PICC removal + anticoagulation arm (28.5% vs. 4.8% p = 0.007). Catheter-removal alone results in significantly reduced major bleeding compared with catheter-removal plus anticoagulation. In select patients, catheter removal alone may be an option for CRT.

Causes and outcomes of finger ischemia in hospitalized patients in the intensive care unit

OBJECTIVE

Vascular surgeons may be consulted to evaluate hospitalized patients with finger ischemia. We sought to characterize causes and outcomes of finger ischemia in intensive care unit (ICU) patients.

METHODS

All ICU patients who underwent evaluation for finger ischemia from 2008 to 2015 were reviewed. All were evaluated with finger photoplethysmography. The patients' demographics, comorbidities, ICU care (ventilator status, arterial lines, use of vasoactive medications), finger amputations, and survival were also recorded. ICU patients were compared with concurrently evaluated non-ICU inpatients with finger ischemia.

RESULTS

There were 98 ICU patients (55 male, 43 female) identified. The mean age was 57.1 ± 16.8 years. Of these patients, 42 (43%) were in the surgical ICU and 56 (57%) in the medical ICU. Seventy (72%) had abnormal findings on finger photoplethysmography, 40 (69%) unilateral and 30 (31%) bilateral. Thirty-six (37%) had ischemia associated with an arterial line. Twelve (13%) had concomitant toe ischemia. Eighty (82%) were receiving vasoactive medications at the time of diagnosis, with the most frequent being phenylephrine (55%), norepinephrine (47%), ephedrine (31%), epinephrine (26%), and vasopressin (24%). Treatment was with anticoagulation in 88 (90%; therapeutic, 48%; prophylactic, 42%) and antiplatelet agents in 59 (60%; aspirin, 51%; clopidogrel, 15%). Other frequently associated conditions included mechanical ventilation at time of diagnosis (37%), diabetes (34%), peripheral arterial disease (32%), dialysis dependence (31%), cancer (24%), and sepsis (20%). Only five patients (5%) ultimately required finger amputation. The 30-day, 1-year, and 3-year survival was 84%, 69%, and 59%. By Cox proportional hazards modeling, cancer (hazard ratio, 2.4; 95% confidence interval, 1.1-5.6; P = .035) was an independent predictor of mortality. There were 50 concurrent non-ICU patients with finger ischemia. Non-ICU patients were more likely to have connective tissue disorders (26% vs 13%; P = .05) and hyperlipidemia (42% vs 24%; P = .03) and to undergo finger amputations (16% vs 5%; P = .03).

CONCLUSIONS

Finger ischemia in the ICU is frequently associated with the presence of arterial lines and the use of vasopressor medications, of which phenylephrine and norepinephrine are most frequent. Anticoagulation or antiplatelet therapy is appropriate treatment. Whereas progression to amputation is rare, patients with finger ischemia in the ICU have a high rate of mortality, particularly in the presence of cancer. Non-ICU patients hospitalized with finger ischemia more frequently require finger amputations, probably because of more frequent connective tissue disorders.

Characterization of profunda femoris vein thrombosis

OBJECTIVE

The incidence of and risk factors for profunda femoris vein (PFV) thrombosis are poorly characterized. We prospectively identified patients with PFV deep venous thrombosis (DVT) to characterize the demographics and anatomic distribution of proximal DVT in patients with PFV DVT.

METHODS

A prospective study was conducted of patients at a tertiary care university hospital with DVT diagnosed by venous duplex ultrasound scanning between June 2014 and June 2015. DVT patients were categorized as having PFV involvement (yes or no), and the anatomic distribution of other sites of ipsilateral venous thrombi was further stratified to determine whether there was external iliac vein (EIV), common femoral vein (CFV), or femoropopliteal vein (FPV) DVT. Demographic characteristics of the patients were compared between groups, PFV DVT vs proximal DVT without PFV DVT.

RESULTS

Of 4584 lower extremity venous duplex ultrasound studies performed, 398 (8.7%) scans were positive for proximal DVT from 260 patients; 23.1% of patients with DVT (60/260) had DVT involving the PFV. Of 112 patients who had CFV DVT, 55 (49.1%) also had ipsilateral involvement of the PFV. Of 60 patients with PFV DVT, 55 (91.7%) had involvement of the ipsilateral CFV. Patients in the PFV DVT group were more likely to have a history of a hypercoagulable disorder (26.7% vs 14.5%; P = .029) and a history of immobility (58.3% vs 42%; P = .026) compared with those with proximal DVT without PFV DVT. There were no differences in smoking, recent surgery, personal or family history of DVT, other medical comorbidities, inpatient status, or survival. There was no difference in laterality of DVT between the PFV DVT and proximal DVT without PFV DVT groups (35% vs 41.5% left, 35% vs 33.5% right, 30% vs 25% bilateral; P = .619). There was a higher proportion of PFV DVT with EIV involvement (21.7% vs 2.5%; P < .00001) and a higher proportion of PFV DVT with CFV + FPV involvement (65.0% vs 19%; P < .00001) compared with proximal DVT without PFV DVT. There was no difference in survival between the PFV DVT and proximal DVT without PFV DVT groups.

CONCLUSIONS

Patients with PFV thrombosis tend to have more thrombus burden with more frequent concurrent DVT in the EIV and FPV. Patients with PFV DVT are also more likely to have a history of hypercoagulable disorder and immobility. Ultrasound protocols for assessment of DVT should include routine examination of the PFV as a potential marker of a more virulent prothrombotic state.

Nonatherosclerotic vascular causes of acute abdominal pain

BACKGROUND

To examine the epidemiology, treatments, and outcomes of acute symptomatic non-atherosclerotic mesenteric vascular disease.

METHODS

Subjects were reviewed over a six year period. Categories included embolism (EM), dissection (DI), and aneurysm (AN). Presentation, demographics, treatment and outcomes were compared.

RESULTS

46 patients were identified (EM:20, AN:15, DI:11). Age at presentation differed (EM: 66.3, AN 62.4, DI 54.6, p < .05). EM more likely affected the superior mesenteric artery (EM80%, AN20%, DI45%, p = .002), DI hepatic artery (EM20%, AN13%, DI55%, p < .05), and AN mesenteric branches (EM5%, AN47%, DI0%; p = .001). EM more likely had history of arrhythmia (EM40%, AN7%, DI0%, p,0.05) and diarrhea (EM30%, AN7%, DI0%, p < .05). Treatment was most often surgical in EM (EM85%, AN33%, DI9%, p < .001), endovascular in AN (EM5%, AN40%, DI 9%, p < .02), and conservative in DI (EM15%, AN 33%, DI82%, p < .05). In hospital mortality was infrequent (EM10%, AN7%, DI0%, p = ns). Mean hospital length of stay differed by mechanism (EM13.6days, AN9.2, DI2.3, p = .005). Median follow up was 61 months. Survival at 1, 3 and 5 years for emboli was 75%, 70% and 59%, for aneurysms 93%, 86%, and 77%, and for dissections 100% at all time points (p = .043 log rank).

CONCLUSIONS

Patients with EM, AN, and DI differ in age, anatomic distribution and method of treatment. The etiology significantly affects long term survival.

Interhospital vascular surgery transfers to a tertiary care hospital

OBJECTIVE

Interhospital transfers (IHTs) to tertiary care centers are linked to lower operative mortality in vascular surgery patients. However, IHT incurs great health care costs, and some transfers may be unnecessary or futile. In this study, we characterize the patterns of IHT at a tertiary care center to examine appropriateness of transfer for vascular surgery care.

METHODS

A retrospective review was performed of all IHT requests made to our institution from July 2014 to October 2015. Interhospital physician communication and reasons for not accepting transfers were reviewed. Diagnosis, intervention, referring hospital size, and mortality were examined. Follow-up for all patients was reviewed.

RESULTS

We reviewed 235 IHT requests for vascular surgical care involving 210 patients during 15 months; 33% of requested transfers did not occur, most commonly after communication with the physician resulting in reassurance (35%), clinic referral (30%), or further local workup obviating need for transfer (11%); 67% of requests were accepted. Accepted transfers generally carried life- or limb-threatening diagnoses (70%). Next most common transfer reasons were infection or nonhealing wounds (7%) and nonurgent postoperative complications (7%). Of accepted transfers, 72% resulted in operative or endovascular intervention; 20% were performed <8 hours of arrival, 12% <24 hours of arrival, and 68% during hospital admission (average of 3 days); 28% of accepted patients received no intervention. Small hospitals (<100 beds) were more likely than large hospitals (>300 beds) to transfer patients not requiring intervention (47% vs 18%; P = .005) and for infection or nonhealing wounds (30% vs 10%; P = .013). Based on referring hospital size, there was no difference in IHTs requiring emergent, urgent, or nonurgent operations. There was also no difference in transport time, time from consultation to arrival, or death of patients according to hospital size. Overall patient mortality was 12%.

CONCLUSIONS

Expectedly, most vascular surgery IHTs are for life- or limb-threatening diagnoses, and most of these patients receive an operation. Transfer efficiency and surgical case urgency are similar across hospital sizes. Nonoperative IHTs are sent more often by small hospitals and may represent a resource disparity that would benefit from regionalizing nonurgent vascular care.

Demographic and echocardiographic predictors of anatomic site and outcomes of surgical interventions for cardiogenic limb emboli

We sought to determine if symptomatic cardiogenic limb emboli have a random distribution or if there are demographic or echocardiographic factors that predict site of embolization, limb salvage and mortality. Upper (UE) and lower extremity (LE) emboli were evaluated over a 16-year period (1996-2012). Demographic (age, gender, smoking, medical comorbidities) and echocardiographic data were analyzed to determine predictors of embolic site. All symptomatic patients underwent surgical revascularization. Limb salvage and mortality were compared with Kaplan-Meier analysis. A total of 161 patients with symptomatic cardiogenic emboli were identified: 56 UE and 105 LE. The female-to-male ratio for UE emboli (70%:30%) was significantly higher than for LE emboli (47%:53%, p=0.008). No other demographic factors were statistically different. Upper extremity patients were more likely to have atrial fibrillation (50% vs 29.8%, p=0.028), while LE patients had a higher percentage of aortic or mitral valvular disease or intracardiac thrombus (71.4% vs 52.5%, p=0.038). The 30-day limb salvage was higher for UE compared to LE (100% vs 88%, p=0.008). There was a trend toward higher 30-day mortality in the LE group (14% vs 5%, p=0.11). Survival at 1, 3, and 5 years were similar (UE: 62.2%, 44.2%, 35.3%; LE: 69.1%, 47.5%, 30.3%; p=ns). Upper extremity emboli are more frequent in women and patients with atrial fibrillation. Lower extremity emboli are more frequent in the presence of valvular disease or intracardiac thrombus, and are associated with increased 30-day limb loss and mortality. These findings suggest gender- and cardiac-specific differences in patterns of blood flow leading to preferential sites of peripheral embolization.

Endovascular Management of Paget-Schroetter Syndrome

Spontaneous thrombosis of the axillary and subclavian venous segments in young, healthy adults (effort thrombosis or Paget-Schroetter syndrome) is a rare but potentially disabling affliction. The diagnosis should be suspected in any young patient presenting with unilateral arm swelling. Typically, the dominant arm is affected, and frequent, repetitive arm use is a common component of the patients' history. Although the diagnosis can often be confirmed with a venous duplex evaluation, the central location of the venous abnormality occasionally mandates cross-sectional imaging or contrast venography to confirm the diagnosis. The underlying pathophysiology of this disorder is felt to be repetitive venous trauma owing to arm motion in the narrow anatomic space between the clavicle and first rib. The treatment of Paget-Schroetter syndrome is controversial and varies according to individual, institutional, and regional preferences. In general, the trend is toward more aggressive endovascular treatment. Prompt anticoagulation is generally accepted as the minimal treatment offered. Catheter-directed thrombolysis has also acquired a prominent role in reestablishing venous patency. The importance of relieving the anatomic compression of the subclavian vein by first rib resection remains controversial, with some experts advocating surgical intervention in all affected patients, whereas others perform this procedure selectively in cases of persistent venous stenosis or ongoing symptoms. Angioplasty with or without stenting is generally discouraged in the absence of anatomic decompression but may play an adjunctive role in patients undergoing first rib resection.

The Natural History of Indeterminate Blunt Cerebrovascular Injury

IMPORTANCE

The Denver criteria grade blunt cerebrovascular injuries (BCVIs) but fail to capture many patients with indeterminate findings on initial imaging.

OBJECTIVE

To evaluate outcomes and clinical significance of indeterminate BCVIs (iBCVIs).

DESIGN, SETTING, AND PARTICIPANTS

A retrospective review of all patients treated for BCVIs at our institution from January 1, 2007, through July 31, 2014, was completed. Patients were divided into 2 groups: those with true BCVIs as defined by the Denver criteria and those with iBCVIs, which was any initial imaging suggestive of a cerebrovascular arterial injury not classifiable by the Denver criteria.

MAIN OUTCOMES AND MEASURES

Primary outcomes were rate of resolution of iBCVIs, freedom from cerebrovascular accident (CVA) or transient ischemic attack (TIA), and 30-day mortality.

RESULTS

We identified 100 patients with 138 BCVIs: 79 with true BCVIs and 59 with iBCVIs. With serial imaging, 23 iBCVIs (39.0%) resolved and 21 (35.6%) remained indeterminate, whereas 15 (25.4%) progressed to true BCVI. The rate of CVA or TIA in the iBCVI group was 5.1% compared with 15.2% in the true BCVI group (P = .06). Of the 15 total CVAs or TIAs, 11 (73.3%) resulted from carotid injury and 4 (26.7%) from vertebral artery occlusion (P = .03). By Kaplan-Meier analysis, there was no difference in freedom from CVA or TIA for the 2 groups (P = .07). Median clinical follow-up was 91 days. Overall and 30-day mortality for the entire series were 17.4% and 15.2%, respectively. There was no difference in long-term or 30-day mortality between true BCVI and iBCVI groups.

CONCLUSIONS AND RELEVANCE

Detection of iBCVI has become a common clinical conundrum with improved and routine imaging. Indeterminate BCVI is not completely benign, with 25.4% demonstrating anatomical progression to true BCVI and 5.1% developing cerebrovascular symptoms. We therefore recommend serial imaging and antiplatelet therapy for iBCVI.

Management of catheter-associated upper extremity deep venous thrombosis

Central venous catheters or peripherally inserted central catheters are major risk factors for upper extremity deep venous thrombosis (UEDVT). The body and quality of literature evaluating catheter-associated (CA) UEDVT have increased, yet strong evidence on screening, diagnosis, prevention, and optimal treatment is limited. We herein review the current evidence of CA UEDVT that can be applied clinically. Principally, we review the anatomy and definition of CA UEDVT, identification of risk factors, utility of duplex ultrasound as the preferred diagnostic modality, preventive strategies, and an algorithm for management of CA UEDVT.

Nasal methicillin-resistant Staphylococcus aureus colonization is associated with increased wound occurrence after major lower extremity amputation

OBJECTIVE

Wound occurrence (WO) after major lower extremity amputation (MLEA) can be due to wound infection or sterile dehiscence. We sought to determine the association of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization and other patient factors with overall WO, WO due to wound infection, and WO due to sterile dehiscence.

METHODS

The medical records of all patients undergoing MLEA from August 1, 2011, to November 1, 2013, were reviewed. Demographic data, hemoglobin A1c level, albumin concentration, dialysis dependence, peripheral vascular disease (PVD), nasal MRSA colonization, and diabetes mellitus (DM) were examined as variables. The overall WO rate was determined, and the cause of WO was categorized as either a sterile dehiscence or a wound infection.

RESULTS

Eighty-three patients underwent 96 MLEAs during a 27-month period. The rates of overall WO, WO due to infection, and WO due to sterile dehiscence were 39%, 19%, and 19%, respectively (1% developed a traumatic wound). On univariate analysis, PVD, MRSA colonization, DM, and dialysis dependence were all associated with higher rates of overall WO (P < .05). On multivariate analysis, MRSA colonization was associated with higher rates of overall WO (P = .03) and WO due to wound infection (11% vs 45%; P < .01). DM and PVD were associated with higher rates of overall WO and WO due to sterile dehiscence on both univariate and multivariate analysis (P < .05).

CONCLUSIONS

Nasal MRSA colonization is associated with higher rates of overall WO and WO due to wound infection. DM and PVD are associated with higher rates of overall WO and WO due to sterile dehiscence but are not associated with WO due to wound infection. Further studies addressing the effect of nasal MRSA eradication on postoperative wound outcomes after MLEA are warranted.

Objective measurement of lower extremity function and quality of life after surgical revascularization for critical lower extremity ischemia

BACKGROUND

Outcomes of revascularization for critical limb ischemia (CLI) have historically been patency, limb salvage, and survival. Functional status and quality of life have not been well described. This study used functional and quality of life assessments to measure patient-centered outcomes after revascularization for CLI.

METHODS

The study observed 18 patients (age, 65 ± 11 years) prospectively before and after lower extremity bypass for CLI. Patients completed the Short Physical Performance Battery, which measures walking speed, leg strength, and balance, as well as performed a 6-minute walk, and calorie expenditure was measured by an accelerometer. Isometric muscle strength was assessed with the Muscle Function Evaluation chair (Metitur, Helsinki, Finland). Quality of life instruments included the 36-Item Short Form Health Survey and the Vascular Quality of Life questionnaire. Patients' preoperative status was compared with 4-month postoperative status.

RESULTS

Muscle Function Evaluation chair measurements of ipsilateral leg strength demonstrated a significant increase in knee flexion from 64 ± 62 N to 135 ± 133 N (P = .038) and nearly significant increase in knee extension from 120 ± 110 N to 186 ± 85 N (P = .062) and ankle plantar flexion from 178 ± 126 N to 267 ± 252 N (P = .078). In the contralateral leg, knee flexion increased from 71 ± 96 N to 149 ± 162 N (P = .028) and knee extension from 162 ± 112 N to 239 ± 158 N (P = .036). Absolute improvements were noted in 6-minute walk distance, daily calorie expenditure, and individual domains and overall Short Physical Performance Battery scores, and upper extremity strength decreased, although none were significant. The Vascular Quality of Life questionnaire captured significant improvement in all individual domains and overall score (P < .015). Significant improvement was noted only for bodily pain (P = .011) on the 36-Item Short Form Health Survey.

CONCLUSIONS

Despite lack of statistical improvement in most functional test results, revascularization for CLI results in improved patient-perceived leg function. Significant improvements in isometric muscle strength may explain the measured improvement in quality of life after revascularization for CLI.

Paroxysmal nocturnal hemoglobinuria: a red clot syndrome

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired, nonmalignant disorder of hematopoietic stem cells characterized by hemolysis, diminished hematopoiesis, and thrombophilia. We describe a 65-year-old woman with known PNH and peripheral arterial disease who presented with critical limb ischemia and a nonhealing left foot ulcer. She underwent surgical bypass of a diffusely diseased left superficial femoral artery with autologous reversed saphenous vein graft. Her postoperative course was complicated by wound sepsis and PNH exacerbation with resultant graft thrombosis requiring an above-knee amputation. This case highlights several key concepts relevant to the management of vascular surgery patients with PNH: (1) their predisposition for arterial and venous thrombosis; (2) hypercoagulability despite standard anticoagulation regimens; (3) the role of eculizumab (a monoclonal antibody that inhibits complement activation used to treat PNH) in reducing thrombotic complications and hemolysis; and (4) complications associated with the immunosuppressive effects of eculizumab. We recommend careful monitoring of hemolysis and immunosuppression, aggressive anticoagulation, frequent graft surveillance, and early consultation with hematology.

Improving the quality of the surgical morbidity and mortality conference: a prospective intervention study

PURPOSE

Surgical morbidity and mortality conferences (M&MCs) provide surgeons with an opportunity to confront medical errors, discuss adverse events, and learn from their mistakes. Yet, no standardized format for these conferences exists. The authors hypothesized that introducing a standardized presentation format using a validated framework would improve presentation quality and educational outcomes for all attendees.

METHOD

Following a review of the literature and the solicitation of experts' opinions, the authors adapted a validated communication tool-the SBAR (Situation, Background, Assessment, Recommendations) framework. In 2010, they then introduced this novel standardized presentation format into the surgical M&MCs at the Oregon Health & Science University. The authors assessed three outcome measures--user satisfaction, presentation quality, and education outcomes--before and after implementation of their standardized presentation format.

RESULTS

Over the six-month study period, residents delivered 66 presentations to 197 faculty, resident, and medical student attendees. Attendees' performance on the multiple-choice questionnaires improved after the intervention, indicating an improvement in their knowledge. Presentation quality also improved significantly after the intervention, according to evaluations by trained faculty assessors. They noted specific improvements in the quality of the Background, Assessment, and Recommendation sections.

CONCLUSIONS

The M&MC plays a pivotal role in educating residents and improving patient safety. Standardizing the M&MC presentation format using an adapted SBAR framework improved the quality of residents' presentations and attendees' educational outcomes. The authors recommend using such a standardized presentation format to enhance the educational value of M&MCs, with the goal of improving surgeons' knowledge, skills, and patient care practices.

Symptomatic venous thromboembolism after femoral vein harvest

OBJECTIVE

The femoral vein is increasingly utilized as a conduit in major arterial and venous reconstruction. However, perioperative complications, especially venous thromboembolism (VTE) associated with femoral vein harvest (FVH), are not well described. The purpose of this study was to determine the incidence and risk factors for the development of symptomatic VTE in patients who undergo FVH.

METHODS

We conducted a retrospective cohort study of all patients who underwent FVH over a 5-year period at a single institution. Patient clinical characteristics, indications for surgery, postoperative venous duplex scans, and computerized tomography scans of the chest were gathered and reviewed from an electronic medical record query. Statistical analysis was performed to determine which factors correlate with development of perioperative complications after FVH.

RESULTS

There were 57 patients (53% male; mean age, 62 years) who underwent 58 FVHs. Of the procedures, 53% were performed for arterial reconstruction and 47% for vascular reconstruction after cancer resection (85% portomesenteric reconstruction). Perioperative VTEs were diagnosed in 17 of 58 (29%) FVH procedures. Sixteen ipsilateral deep vein thromboses (DVTs) occurred distal to the FVH site and five (9%) occurred proximal to the FVH site. The incidence of VTE was significantly greater in patients with malignancy (52% vs 10%; P = .001), and 88% of all VTEs in this series were diagnosed in patients with cancer. All DVTs proximal to the FVH site and all DVTs in the contralateral extremity occurred in patients with malignancy. Pulmonary embolism occurred in two patients. No patients developed compartment syndrome or limb loss. Eight patients (14%) required FVH site wound debridement.

CONCLUSIONS

VTE after FVH occurs more frequently in patients with malignancy. Aggressive and prolonged thromboprophylaxis and routine venous ultrasound surveillance are warranted after FVH in patients with malignancy.

Direct thrombin inhibitors for the treatment of venous thromboembolism: analysis of the Dabigatran versus Warfarin clinical trial

Vitamin-K antagonists have played a dominant role in the long-term management of patients with venous thromboembolism, and large trials from the past decade reinforced warfarin's effectiveness as an intermediate-duration and extended-duration anticoagulant. However, promising new oral direct thrombin inhibitors are proving to be at least as effective and as safe as the vitamin-K antagonists, without the associated hepatic toxicity that was seen with earlier orally administered direct thrombin inhibitors. This article reviews the recently published Dabigatran versus Warfarin in the Treatment of Acute Venous Thromboembolism clinical trial, and discusses the limitations and clinical applicability of the trial, especially in comparison with vitamin-K antagonists and the recently studied oral direct factor Xa inhibitors, rivaroxaban and apixaban.

Peripherally inserted central catheter usage patterns and associated symptomatic upper extremity venous thrombosis

OBJECTIVES

Peripherally inserted central catheters (PICCs) may be complicated by upper extremity (UE) superficial (SVT) or deep venous thrombosis (DVT). The purpose of this study was to determine current PICC insertion patterns and if any PICC or patient characteristics were associated with venous thrombotic complications.

METHODS

All UE venous duplex scans during a 12-month period were reviewed, selecting patients with isolated SVT or DVT and PICCs placed ≤30 days. All UE PICC procedures during the same period were identified from an electronic medical record query. PICC-associated DVTs, categorized by insertion site, were compared with all first-time UE PICCs to determine the rate of UE DVT and isolated UE SVT. Technical and clinical variables in patients with PICC-associated UE DVT also were compared with 172 patients who received a PICC without developing DVT (univariable and multivariable analysis).

RESULTS

We identified 219 isolated UE SVTs and 154 UE DVTs, with 2056 first-time UE PICCs placed during the same period. A PICC was associated with 44 of 219 (20%) isolated UE SVTs and 54 of 154 UE DVTs (35%). The rates of PICC-associated symptomatic UE SVT were 1.9% for basilic, 7.2% for cephalic, and 0% for brachial vein PICCs. The rates of PICC-associated symptomatic UE DVT were 3.1% for basilic, 2.2% for brachial, and 0% for cephalic vein PICCs (χ(2)P < .001). Univariate analysis of technical and patient variables demonstrated that larger PICC diameter, noncephalic insertion, smoking, concurrent malignancy, diabetes, and older age were associated with UE DVT (P < .05). Multivariable analysis showed larger catheter diameter and malignancy were the only variables associated with UE DVT (P < .05).

CONCLUSIONS

The incidence of symptomatic PICC-associated UE DVT is low, but given the number of PICCs placed each year, they account for up to 35% of all diagnosed UE DVTs. Larger-diameter PICCs and malignancy increase the risk for DVT, and further studies are needed to evaluate the optimal vein of first choice for PICC insertion.

Techniques and results of portal vein/superior mesenteric vein reconstruction using femoral and saphenous vein during pancreaticoduodenectomy

BACKGROUND

Patients with pancreatic tumors may have portal vein (PV) and/or superior mesenteric vein (SMV) invasion. In such cases, lower extremity veins can provide an autogenous conduit for PV/SMV reconstruction. Little data exist, however, describing the technique of PV/SMV reconstruction, patency of such reconstructions, and the morbidity of using lower extremity veins for PV/SMV reconstruction during pancreaticoduodenectomy.

METHODS

Thirty-four patients underwent PV/SMV reconstruction during pancreaticoduodenectomy using lower extremity vein. The saphenous vein was preferred for patching and femoral vein for replacement. We analyzed preoperative imaging, reconstruction patency, vein harvest morbidity, and late mortality.

RESULTS

The mean age was 62.6 years. All 34 patients had preoperative computed tomography (CT) imaging and/or endoscopic ultrasound (EUS) scan. Fourteen of the 34 patients had evidence of PV/SMV invasion on CT or EUS scans, 14 did not, and six studies were indeterminate. Twenty-five patients had follow-up imaging, and 22 (88%) had patent reconstructions. Fifteen patients had PV/SMV replacement using femoral vein. Seven of these 15 had minor postoperative lower extremity edema that resolved over time, five had wound complications from the femoral vein harvest site, three of which required minor operative procedures for treatment. Fifteen patients had PV/SMV patching with the great saphenous vein, none had postoperative wound problems, and one had minimal postoperative lower extremity edema. Four patients had PV/SMV patching using femoral vein, none had postoperative wound problems, and one had minimal postoperative lower extremity edema. Compared with patients undergoing pancreaticoduodenectomy without PV/SMV reconstruction, by Kaplan-Meier analysis, there was no difference in late mortality.

CONCLUSION

Preoperative imaging may fail to detect PV/SMV involvement in patients undergoing pancreaticoduodenectomy. The PV/SMV reconstruction with leg vein provides good patency with minimal postoperative lower extremity complications and no increase in late mortality. The lower extremities should be routinely included in the operative field of patients undergoing pancreaticoduodenectomy.