Treatment planning for peripheral arterial disease based on duplex ultrasonography and computed tomography angiography: Consistency, confidence and the value of additional imaging

Choosing the appropriate catheter and wire in peripheral intervention

Endovascular treatment is becoming more common in managing patients with peripheral arterial disease. A carefully planned procedure is crucial for the outcome of the procedure. Several steps are necessary when performing endovascular procedures, including preplanning with vascular imaging using computed tomography angiography (CTA) or magnetic resonance angiography (MRA), choosing the right access and technique, and using the right devices (guidewires, sheaths, catheters). The length, diameter, stiffness, coating, and tip shape of the guidewire should be adjusted according to the initial information and preparation. A sheath is not always necessary but can be beneficial when several catheter changes are planned. There are three types of angiographic catheter (flush, exchange, and selective), each of which should be considered and used wisely according to its function. The guidewire, sheath, and catheter choices will follow from the initial information gathered, the access and technique chosen, and the availability of the devices.

Bifurcated bypass in severe chronic limb threatening ischaemia

OBJECTIVES

Revascularization according to the angiosome concept is of proven importance for limb salvage in chronic limb threatening ischaemia but it is not always practicable. Bifurcated bypasses could be considered as an option when an endovascular approach is not feasible or has already failed and a single bypass would not allow direct revascularization of the ischaemic area. Bifurcated bypasses are characterized by landing on two different arteries, the main artery (in direct continuity with the foot vessels) and the secondary one (perfusing the angiosome district). The aim of this study is to evaluate the safety and effectiveness of bifurcated bypass in chronic limb threatening ischaemia.

METHODS

Thirty-five patients were consecutively treated with a bifurcated bypass for chronic limb threatening ischaemia from January 2014 to December 2019 in a single vascular surgery centre. Data from clinical records and operative registers were collected prospectively in an electronic database and retrospectively analysed. Primary and primary assisted bypass patency, amputation-free survival, morbidity and mortality rates at 12 and 24 months were analysed.

RESULTS

Mean follow-up period was 25.1 months (range 2-72 months). Thirty-six bifurcated bypasses were performed on 35 patients (age 75.3 ± 7.2 years; 69.4% were male). According to Wound, Ischemia, foot Infection classification 22.2% belonged to stage 3 and 77.8% to stage 4 and the mean Rutherford's class was 5.1 ± 0.7. Immediate technical success was 100%. Early mortality and morbidity rates were respectively 5.5%, and 33.3%; foot surgery was performed in 50% of cases with wound healing in all patients. Primary patency and primary assisted bypass patency were 96.7% and 100% at 6 months; 85.2% and 92% at 12 months, 59.9% and 73.4% at 24 months, respectively. Amputation-free survival at 12 and 24 months was, respectively, 95.6% and 78.8%. Overall survival rates at 12 and 24 months were respectively 94.4% and 91.6%.

CONCLUSIONS

Bifurcates bypass can provide good results in patients with chronic limb threatening ischaemia without endovascular option, especially in diabetic ones. Bifurcated bypass is a complex surgical solution, both to be planned and performed, and it is quite invasive for frail patients that should be accurately selected.

Doppler Ultrasound as a Unique Diagnosis Test in Peripheral Arterial Disease

BACKGROUND

The aim of this study was to analyze duplex ultrasound (DUS) and intraoperative angiography concordance for diagnosis of lower limb peripheral artery disease and its value for surgical planning.

MATERIALS AND METHODS

This was a prospective, observational study, including patients who underwent revascularization of the lower limbs during 2018, diagnosed by DUS only or combined with preoperative computed tomography (CT) angiography. The concordance between preoperative DUS or CT angiography and the intraoperative angiography was studied using the Cohen kappa coefficient (k). The degree of agreement between the DUS-based surgical plan and the final surgical technique was also evaluated.

RESULTS

Fifty-one patients were included, with mean age of 71.8 ± 11.96 years (46-94); 23 had chronic kidney disease (45%). In 17 patients (34%), preoperative CT angiography was also performed. DUS showed a sensitivity of 100% (95% confidence interval (CI) [83.3-100%]), 80% (95% CI [50.21-100%,]), and 100% (95% CI [96.43-100%]) at the iliac, femoral, and popliteal sector, respectively, and a specificity of 93.55% (95% CI [83.29-100%]), 95.45% (95% CI [84.48-100%]), and 90.48% (95% CI [75.54-100%]) at the iliac, femoral, and popliteal sector, respectively. The positive predictive value for DUS was 60% (95% CI [7.06-100%]), 88.9% (95% CI [62.8-100%]), and 87.5% (95% CI [68.17-100%]) for the iliac, femoral, and popliteal sectors, respectively, whereas the negative predictive value was 100% (95% CI [98.28-100%]), 91.3% (95% CI [77.61-100%]), and 100% (95% CI, [97.37-100%]). The concordance between DUS and intraoperative angiography showed a k index of 0.587 (P = 0.000) in the iliac sector, 0.799 in the femoral sector (P = 0.000), and 0.699 in the popliteal sector (P = 0.000). The concordance between CT angiography/intraoperative angiography had a k index of 0.71 in the iliac sector (P = 0.0093), 0.566 in the femoral sector (P = 0.006), and 0.5 in the popliteal sector (P = 0.028). DUS-based surgical plan was accurate in 86% of cases (n = 44).

CONCLUSIONS

Our experience suggests that DUS arterial mapping of the femoral and popliteal areas is better than CT angiography and can be considered as a unique preoperative imaging test during the surgical planning in patients undergoing a lower limb revascularization procedure.

Coronary arteries hemodynamics: effect of arterial geometry on hemodynamic parameters causing atherosclerosis

Coronary arteries have high curvatures, and hence, flow through them causes disturbed flow patterns, resulting in stenosis and atherosclerosis. This in turn decreases the myocardial flow perfusion, causing myocardial ischemia and infarction. Therefore, in order to understand the mechanisms of these phenomena caused by high curvatures and branching of coronary arteries, we have conducted elaborate hemodynamic analysis for both (i) idealized coronary arteries with geometrical parameters representing realistic curvatures and stenosis and (ii) patient-specific coronary arteries with stenoses. Firstly, in idealized coronary arteries with approximated realistic arterial geometry representative of their curvedness and stenosis, we have computed the hemodynamic parameters of pressure drop, wall shear stress (WSS) and wall pressure gradient (WPG), and their association with the geometrical parameters of curvedness and stenosis. Secondly, we have similarly determined the wall shear stress and wall pressure gradient distributions in four patient-specific curved stenotic right coronary arteries (RCAs), which were reconstructed from medical images of patients diagnosed with atherosclerosis and stenosis; our results show high WSS and WPG regions at the stenoses and inner wall of the arterial curves. This paper provides useful insights into the causative mechanisms of the high incidence of atherosclerosis in coronary arteries. It also provides guidelines for how simulation of blood flow in patient's coronary arteries and determination of the hemodynamic parameters of WSS and WPG can provide a medical assessment of the risk of development of atherosclerosis and plaque formation, leading to myocardial ischemia and infarction. The novelty of our paper is in our showing how in actual coronary arteries (based on their CT imaging) curvilinearity and narrowing complications affect the computed WSS and WPG, associated with risk of atherosclerosis. This is very important for cardiologists to be able to properly take care of their patients and provide remedial measures before coronary complications lead to myocardial infarctions and necessitate stenting or coronary bypass surgery. We want to go one step further and provide clinical application of our research work. For that, we are offering to cardiologists worldwide to carry out hemodynamic analysis of the medically imaged coronary arteries of their patients and compute the values of the hemodynamic parameters of WSS and WPG, so as to provide them an assessment of the risk of atherosclerosis for their patients. Graphical abstract Theme and aims: Coronary arteries have high curvatures, and hence flow through them causes disturbed flow patterns, resulting in stenosis and atherosclerosis. This in turn decreases the myocardial flow perfusion, causing myocardial ischemia and infarction. Therefore, in order to understand the mechanisms of these phenomena caused by high curvatures and branching of coronary arteries, we have conducted elaborate hemodynamic analysis for both (i) idealized coronary arteries with geometrical parameters representing curvatures and stenosis, and (ii) patient-specific coronary arteries with stenoses. Methods and results: Firstly, in idealized coronary arteries with approximated realistic arterial geometry representative of their curvedness and stenosis, we have computed the hemodynamic parameters of pressure drop, wall shear stress (WSS) and wall pressure gradient (WPG), and their association with the geometrical parameters of curvedness and stenosis. Then, we have determined the wall shear stress and wall pressure gradient distributions in four patient-specific curved stenotic right coronary arteries (RCAs), that were reconstructed from medical images of patients diagnosed with atherosclerosis and stenosis, as illustrated in Figure 1, in which the locations of the stenoses are highlighted by arrows. Figure 1: Three-dimensional CT visualization of arteries in patients with suspected coronary disease. The arteries can be seen as a combination of various curved segments with stenoses at unspecific locations highlighted by arrows. Our results show high WSS and WPG regions at the stenoses and inner wall of the arterial curves, as depicted in Figure 2. Therein, the encapsulations show (i) high WSS, and (ii) high WPG regions at the stenosis and inner wall of the arterial curves. Figure 2: WSS and WPG surface plot of realistic arteries (a), (b), (c) and (d), wherein the small squared parts are enlarged to show the detailed localized contour plots at the stenotic regions. Therein, the circular encapsulations show (i) high WSS and (ii) high WPG regions at the stenosis and inner wall of the arterial curves. Conclusion and novelty: This paper provides useful insights into the causative mechanisms of the high incidence of atherosclerosis in coronary arteries. It also provides guidelines for how simulation of blood flow in patient coronary arteries and determination of the hemodynamic parameters of WSS and WPG can provide a medical assessment of the risk of development of atherosclerosis and plaque formation, leading to myocardial ischemia and infarction. The novelty of our paper is our showing how in actual coronary arteries (based on their CT imaging), curvilinearity and narrowing complications affect the computed WSS and WPG associated with risk of atherosclerosis. This is very important for cardiologists to be able to properly take care of their patients and provide remedial measures before coronary complications lead to myocardial infarctions and necessitate stenting or coronary bypass surgery.

Preprocedural Cross-Sectional Imaging Prior to Percutaneous Peripheral Arterial Disease Interventions

Preprocedural cross-sectional imaging (PCSI) for peripheral artery disease (PAD) may vary due to patient complexity, anatomical disease burden, and physician preference. The objective of this study was to determine the utility of PCSI prior to percutaneous vascular interventions (PVIs) for PAD. Patients receiving first time lower extremity angiograms from 2013 to 2015 at a single institution were evaluated for PCSI performed within 180 days, defined as computed tomography angiography (CTA) or magnetic resonance angiography (MRA) evaluating abdominal to pedal vasculature. The primary outcome was technical success defined as improving the target outflow vessels to <30% stenosis. Of the 346 patients who underwent lower extremity angiograms, 158 (45.7%) patients had PCSI, including 150 patients had CTA and 8 patients had MRA. Of these, 48% were ordered by the referring provider (84% at an outside institution). Preprocedural cross-sectional imaging was performed at a median of 26 days (interquartile range: 9-53) prior to the procedure. The analysis of the institution's 5 vascular surgeons identified PCSI rates ranging from 31% to 70%. On multivariate analysis, chronic kidney disease (odds ratio [OR] = 0.35; 95% confidence interval [CI]: 0.17-0.73) was associated with less PSCI usage, and inpatient/emergency department evaluation (OR = 3.20; 95% CI: 1.58-6.50) and aortoiliac disease (OR = 2.78; 95% CI: 1.46-5.29) were associated with higher usage. After excluding 31 diagnostic procedures, technical success was not statistically significant with PSCI (91.3%) compared to without PCSI (85.6%), P = .11. When analyzing 89 femoral-popliteal occlusions, technical success was higher with PCSI (88%) compared to procedures without (69%) P = .026. Our analysis demonstrates that routine ordering of PCSI may not be warranted when considering technical success of PVI; however, PCSI may be helpful in treatment planning. Further studies are needed to confirm these findings in another practice setting, with more prescriptive use of PCSI to improve procedural success, and thereby improve the value of PCSI.

Real-world outcomes of endovascular treatment in a non-selected population with peripheral artery disease - prospective study with 2-year follow-up

Background: The study aimed to evaluate the outcomes of percutaneous transluminal angioplasty (PTA) in lower-extremity peripheral artery disease (PAD) patients. Patients and methods: A multi-centre, observational study was performed with 32 German and Austrian centres contributing data to the PTA registry. Data of 1,781 patients with lower-leg and pelvic PAD who were suitable for endovascular PTA treatment were contributed from participating centres. Data from 1,533 patients are reported here (1,055 male and 478 female). This study did not have exclusion criteria. Quality of life (QOL) questionnaire (EQ-5D) scores, Rutherford classification, mortality, patency rate and details of major adverse cardiovascular events were collected at 6-, 12-, 18-, and 24-month follow ups. Results: PTA with/without stenting achieved 90.3 %, 86.5 %, 82.7 %, and 71.9 % technical success (recanalisation achieving ≥ 70 % patency, no evidence of embolisation, recoiling or dissection) in iliac, femoral, popliteal, and below-the-knee arteries, respectively. Procedural/postprocedural complications occurred in 142 (9.3 %, 1 death) and 74 (4.8 %) patients. QOL, mobility, self-care, activity, and pain/discomfort scores improved (p < 0.01), anxiety/depression was insignificantly improved. During follow-up, 409 (26.7 %) patients were hospitalised for PAD, 281 (18.3 %) required reintervention, and 145 (9.5 %) died or needed amputation (n = 49; 3.2 %). Multivariate analysis demonstrated poorer outcomes in patients with comorbidities. Conclusions: PTA with/without stenting is effective, safe, and widely applicable, with few complications. It improves QOL, but not anxiety/depression.

Cost Analysis of Imaging Diagnostic Tests Used in the Management of Peripheral Arterial Disease

The purpose of this paper was to compare the costs of three noninvasive diagnostic investigations as the initial tests in peripheral artery disease management in Romania.

A cost analysis of three imaging diagnostic tests was performed at the university hospital in Timișoara, Romania. The tests were as follows: arterial Duplex Ultrasound Scanning, Computed Tomography Angiography, and Contrast-enhanced Magnetic Resonance Angiography. The evaluation of the diagnostic test performance was performed together with the calculation of the real costs of each investigation. Finally, an economic evaluation of different diagnostic tests was done.

A number of 46 patients (36 male and 10 female) were included in the study. The selected patients have been subjected to a total number of 61 diagnostic tests prior to the therapeutic decision. Both in terms of sensitivity and specificity, Duplex Ultrasound Scanning and Computed Tomography Angiography showed little difference in our study. The cost analysis results showed a net economic advantage if Duplex Ultrasound Scanning is applied as a diagnostic method under conditions of obtaining a similar effect.

In conclusion, Duplex Ultrasound Scanning is accurate, safe, and cost-effective in designing the final therapeutic plan in peripheral artery disease (PAD), especially in the femoropopliteal segment.

Critical Limb Ischemia: An Expert Statement

Critical limb ischemia (CLI), the most advanced form of peripheral artery disease, is associated with significant morbidity, mortality, and health care resource utilization. It is also associated with physical, as well as psychosocial, consequences such as amputation and depression. Importantly, after a major amputation, patients are at heightened risk of amputation on the contralateral leg. However, despite the technological advances to manage CLI with minimally invasive technologies, this condition often remains untreated, with significant disparities in revascularization and amputation rates according to race, socioeconomic status, and geographic region. Care remains disparate across medical specialties in this rapidly evolving field. Many challenges persist, including appropriate reimbursement for treating complex patients with difficult anatomy. This paper provides a comprehensive summary that includes diagnostic assessment and analysis, endovascular versus open surgical treatment, regenerative and adjunctive therapies, and other important aspects of CLI.

New simple image overlay system using a tablet PC for pinpoint identification of the appropriate site for anastomosis in peripheral arterial reconstruction

PURPOSE

To evaluate the accuracy and utility of a new image overlay system using a tablet PC for patients undergoing peripheral arterial reconstruction.

METHODS

Eleven limbs treated with distal bypass surgery were studied. Three-dimensional images obtained by processing a preoperative contrast-enhanced computed tomography scan were superimposed onto the back-camera images of a tablet PC. We used this system to pinpoint a planned distal anastomotic site preoperatively and to make a precise incision directly above it during surgery. We used a branch artery near the distal anastomotic site as a reference point and the accuracy of the system was validated by comparing its results with the intraoperative findings. The precision of the system was also compared with that of a preoperative ultrasonographic examination.

RESULTS

Both the image overlay system and ultrasonography (US) accurately identified the target branch artery in all except one limb. In that limb, which had a very small reference branch artery, preoperative US wrongly identified another branch, whereas the image overlay system located the target branch with an error of 10 mm.

CONCLUSIONS

Our image overlay system was easy to use and allowed us to precisely identify a target artery preoperatively. Therefore, this system could be helpful for pinpointing the most accurate incision site during surgery.