The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms

Deciphering Popliteal Artery Aneurysm Patient Diversity: Insights From a Cluster Analysis of the POPART Registry

BACKGROUND

Popliteal artery aneurysms (PAAs) are the most common peripheral aneurysm. However, due to its rarity, the cumulative body of evidence regarding patient patterns, treatment strategies, and perioperative outcomes is limited. This analysis aims to investigate distinct phenotypical patient profiles and associated treatment and outcomes in patients with a PAA by performing an unsupervised clustering analysis of the POPART (Practice of Popliteal Artery Aneurysm Repair and Therapy) registry.

METHODS AND RESULTS

A cluster analysis (using k-means clustering) was performed on data obtained from the multicenter POPART registry (42 centers from Germany and Luxembourg). Sensitivity analyses were conducted to explore validity and stability. Using 2 clusters, patients were primarily separated by the absence or presence of clinical symptoms. Within the cluster of symptomatic patients, the main difference between patients with acute limb ischemia presentation and nonemergency symptomatic patients was PAA diameter. When using 6 clusters, patients were primarily grouped by comorbidities, with patients with acute limb ischemia forming a separate cluster. Despite markedly different risk profiles, perioperative complication rates appeared to be positively associated with the proportion of emergency patients. However, clusters with a higher proportion of patients having any symptoms before treatment experienced a lower rate of perioperative complications.

CONCLUSIONS

The conducted analyses revealed both an insight to the public health reality of PAA care as well as patients with PAA at elevated risk for adverse outcomes. This analysis suggests that the preoperative clinic is a far more crucial adjunct to the patient's preoperative risk assessment than the patient's epidemiological profile by itself.

Retrospective analysis of 1,203 cases of referral to a quaternary vascular surgery outpatient clinic within the Unified Health System, São Paulo, Brazil

OBJECTIVE

Through a retrospective analysis of 1,203 cases of referral from primary healthcare units to a specialized quaternary vascular surgical service, the findings of this study revealed a high proportion of inappropriate referrals, which may represent a substantial subutilization of this highly complex service. Consequently, in this study, we aimed to evaluate 1,203 cases of referral to a quaternary vascular surgical service, in São Paulo, Brazil, over a 6-year period, to assess the appropriate need for referral; in addition to the prevalence of surgical indications.

METHODS

In this retrospective analysis, we reviewed the institutional records of participants referred from Basic Healthcare Units to a vascular surgical service inside the Brazilian Unified Health System, between May 2015 and December 2020. Demographic and clinical data were collected. The participants were stratified, as per the reason for referral to the vascular surgical service, previous imaging studies, and surgical treatment indications. Referral appropriateness and complementary examinations were evaluated for each disease cohort. Finally, the prevalence of cases requiring surgical treatment was defined as the outcome measure.

RESULTS

Of the 1,203 referrals evaluated, venous disease was the main reason for referral (53%), followed by peripheral arterial disease (19.4%). A considerable proportion of participants had been referred without complementary imaging or after a long duration of undergoing an examination. Referrals were regarded as inappropriate in 517 (43%) cases. Of these, 32 cases (6.2%) had been referred to the vascular surgical service, as the incorrect specialty. The percentage of referred participants who ultimately underwent surgical treatment was 39.92%. Carotid (18%) and peripheral arterial diseases (18.4%) were correlated with a lower prevalence of surgical treatments.

CONCLUSION

The rate of referral appropriateness to specialized vascular care from primary care settings was low. This may represent a subutilization of quaternary surgical services, with low rates of surgical treatment.

Bypass Patency and Amputation-Free Survival after Popliteal Aneurysm Exclusion Significantly Depends on Patient Age and Medical Complications: A Detailed Dual-Center Analysis of 395 Consecutive Elective and Emergency Procedures

Background/Objectives: A popliteal artery aneurysm (PAA) is traditionally treated by an open PAA repair (OPAR) with a popliteo-popliteal venous graft interposition. Although excellent outcomes have been reported in elective cases, the results are much worse in cases of emergency presentation or with the necessity of adjunct procedures. This study aimed to identify the risk factors that might decrease amputation-free survival (efficacy endpoint) and lower graft patency (technical endpoint). Patients and Methods: A dual-center retrospective analysis was performed from 2000 to 2021 covering all consecutive PAA repairs stratified for elective vs. emergency repair, considering the patient (i.e., age and comorbidities), PAA (i.e., diameter and tibial runoff vessels), and procedural characteristics (i.e., procedure time, material, and bypass configuration). Descriptive, univariate, and multivariate statistics were used. Results: In 316 patients (69.8 ± 10.5 years), 395 PAAs (mean diameter 31.9 ± 12.9 mm) were operated, 67 as an emergency procedure (6× rupture; 93.8% severe acute limb ischemia). The majority had OPAR (366 procedures). Emergency patients had worse pre- and postoperative tibial runoff, longer procedure times, and more complex reconstructions harboring a variety of adjunct procedures as well as more medical and surgical complications (all p < 0.001). Overall, the in-hospital major amputation rate and mortality rate were 3.6% and 0.8%, respectively. The median follow-up was 49 months. Five-year primary and secondary patency rates were 80% and 94.7%. Patency for venous grafts outperformed alloplastic and composite reconstructions (p < 0.001), but prolonged the average procedure time by 51.4 (24.3-78.6) min (p < 0.001). Amputation-free survival was significantly better after elective procedures (p < 0.001), but only during the early (in-hospital) phase. An increase in patient age and any medical complications were significant negative predictors, regardless of the aneurysm size. Conclusions: A popliteo-popliteal vein interposition remains the gold standard for treatment despite a probably longer procedure time for both elective and emergency PAA repairs. To determine the most effective treatment strategies for older and probably frailer patients, factors such as the aneurysm size and the patient's overall condition should be considered.

Co-prevalence of arterial aneurysm location - a correlation analysis based on a retrospective cross-sectional observational study

Background: The aim of this retrospective single-centre cross-sectional observational study was to investigate co-prevalence of arterial aneurysm location systematically. Patients and methods: Patients with the diagnosis of any arterial aneurysm from January 2006 to January 2016 were investigated in a single centre. Patients with hereditary disorders of connective tissue, systemic inflammatory disease, or arterial pathologies other than true aneurysms were excluded. Aneurysm locations were assessed for every patient included. For patients with at least two co-existing aneurysms, co-prevalence of aneurysm location was investigated by calculating correlation coefficients and applying Fisher's exact test. This study report is prepared according to the STROBE statement. Results: Of 3107 identified patients with arterial aneurysms, 918 were excluded. Of the remaining 2189 patients, 951 patients with at least two aneurysms were included in the study. Bilateral aneurysm combinations of paired iliac, femoral and popliteal arteries showed the highest correlation (ϕ=0.35 to 0.67), followed by bilateral combinations of subclavian (ϕ=0.36) and internal carotid (ϕ=0.38) arteries. Abdominal aortic aneurysms in combination with visceral artery aneurysms (ϕ=-0.24 to -0.12), popliteal arteries (ϕ=-0.22) and the ascending aorta (ϕ=-0.19) showed the lowest correlation, followed by the descending aorta in combination with the common iliac arteries (ϕ=-0.12 to -0.13). Conclusions: In our study sample, aneurysm co-prevalence was highly non-random. This should be considered in the context of aneurysm screening programs.

Sex disparities in popliteal artery aneurysms

OBJECTIVE

Only 5% of patients with popliteal artery aneurysms (PAAs) are female. Evidence on PAA treatment and outcomes in women is therefore scarce. The POPART Registry provides one of Europe's largest data collections regarding PAA treatment. Data on clinical presentation, aneurysm morphology, and perioperative outcomes after open surgical PAA repair in women will be presented.

METHODS

POPART is a multicenter, noninterventional registry for open and endovascular PAA repair, with 42 participating centers in Germany and Luxembourg. All patients aged >18 years who have been treated for PAA since 2010 are eligible for study inclusion. Data collection is based on an online electronic case report form.

RESULTS

Of the 1236 PAAs, 58 (4.8%) were in women. There were no significant differences in age or cardiopulmonary comorbidities. However, female patients had a lower prevalence of contralateral PAAs and abdominal aortic aneurysms (P < .05). PAAs in women were more likely to be symptomatic before surgery (65.5% vs 49.4%; P = .017), with 19% of women presenting with acute limb ischemia (vs 11%; P = .067). Women had smaller aneurysm diameters than men (22.5 mm vs 27 mm; P = .004) and became symptomatic at smaller diameters (20 mm vs 26 mm; P = .002). Only 8.6% of women and 11.6% of men underwent endovascular aneurysm repair (P > .05); therefore, the perioperative outcome analysis focused on open surgical repair. In total, 23.5% of women and 16.9% of men developed perioperative complications (P > .05). There were no differences in major cardiovascular events (P > .05), but women showed a higher incidence of impaired wound healing (15.7% vs 7.2%; P = .05) and major amputation (5.9% vs 1.1%; P = .027). Female sex was significantly associated with the need for nonvascular reinterventions within 30 days after surgery (odds ratio: 2.48, 95% confidence interval: 1.26-4.88), whereas no significant differences in the odds for vascular reinterventions were observed (odds ratio: 1.98, 95% confidence interval: 0.68-5.77). In the multiple logistic regression model, female sex, symptomatic PAAs, poor quality of outflow vessels, and graft material other than vein graft were independently associated with perioperative reinterventions.

CONCLUSIONS

Women have smaller PAAs, are more likely to be symptomatic before treatment, and are more often affected by nonvascular reinterventions in the perioperative course. As our understanding of aneurysmatic diseases in women continues to expand, sex-specific treatment strategies and screening options for women in well-selected cohorts with modified screening protocols should be continuously re-evaluated.

Popliteal artery aneurysm repair-A single center experience

BACKGROUND

Popliteal artery aneurysms (PAAs) are relatively rare but are one of the most common peripheral arterial aneurysms. Open popliteal artery aneurysm repair (OPAR) has been the standard, but technological advancements have made endovascular popliteal artery aneurysm repair (EPAR) a promising alternative. The aim of this study is to compare EPAR and OPAR efficacy and outcomes over a 10-year period.

METHODS

This study retrospectively reviewed 72 patient charts who were diagnosed with PAA or popliteal artery pseudoaneurysm and underwent EPAR or OPAR from 1 January 2010 to 31 December 2019. Endovascular popliteal artery aneurysm repair was used in 37 cases and OPAR in 35 cases.

RESULTS

Graft patency <30 days postoperative was 100% in both EPAR and OPAR groups. Graft patency >90 days postoperative was 72.73% in the EPAR group and 82.35% in the OPAR group (p = 0.477). Graft patency >2 years postoperative was 81.25% in the EPAR group and 86.67% in the OPAR group (p = 0.682). Freedom from reoperation 30-day postoperative was 78.38% in the EPAR group and 80% in the OPAR group (p = 0.865). Freedom from amputation 30-day postoperative was 91.43% in the EPAR group and 94.29% in the OPAR group (p = 0.263). The 30-day survival rate was 94.59% in the EPAR group and 100% in the OPAR group.

CONCLUSIONS

Endovascular repair represents a promising alternative for PAA repair. Our results demonstrate that EPAR has similar outcomes for asymptomatic, acutely symptomatic, and chronic symptomatic patients. Technological advancements of stent properties and refinement of surgical techniques may further improve endovascular techniques.

Emergency treatment of popliteal aneurysms: Single center experience and systematic review and meta-analysis of endovascular versus open repair

BACKGROUND

Popliteal artery aneurysms (PAA) were traditionally treated by open repair (OR). Endovascular repair (ER) has become a new treatment strategy. The aim of this systemic review and meta-analysis was to evaluate and compare the current outcomes of OR and ER in the emergency treatment of PAA.

METHODS

A systematic literature search of the PubMed/Medline database was carried out. Outcomes were 30-day mortality, morbidity, major amputation rate (30 days), major amputation rate (1 year), 1-year primary patency rate, 1-year secondary patency rate and 1-year survival. Additionally, we included clinical data of patients with popliteal aneurysms treated between 2009 and 2021 at the Martin-Luther University Halle-Wittenberg.

RESULTS

We identified two cohort studies from 2014 and 2015 with a total of 199 patients that underwent emergent surgery (39 ER and 160 OR). We also included 26 patients from our institution. For emergency treatment, 30-day major amputation rates (18% vs 3%, Odds Ratio 5.82, 95% CI [1.75; 19.30], p = .004), 30-day mortality rates (10% vs 1%, Odds Ratio 5.57, 95% CI [1.01; 30.58], p = .05), 1-year major amputation rates (15% vs 6% Odds Ratio 3.61, 95% CI [1.18; 11.09], p = .02), 1-year loss of primary patency (54% vs 23%, Odds Ratio 3.19, 95% CI [0.91; 11.20], p = .07), and 1-year loss of secondary patency (44% vs 12%, Odds Ratio 6.91, 95% CI [3.01; 15.83], p < .05) were higher in the ER group when compared to the OR group.

CONCLUSION

Endovascular repair represents an alternative approach for the emergency treatment of PAA. Limited evidence from the available non-randomized studies shows unfavorable outcomes for patients undergoing ER. However, the results are prone to selection bias, and only randomized trials comparing ER to OR might reveal whether a subgroup of patients would benefit from ER as primary treatment of PAA in an emergency setting.

Prosthetic Conduit Use Does Not Adversely Impact Outcomes after Open Repair of Popliteal Artery Aneurysms

BACKGROUND

Single segment, greater saphenous vein (GSV) conduit is considered the optimal bypass conduit among patients undergoing bypass surgery for peripheral artery disease (PAD). While this data has been extrapolated to patients undergoing bypass for popliteal artery aneurysms (PAAs), the pathophysiology of PAA is inherently different when compared to PAD, and the impact of conduit type on long-term outcomes after open repair of PAA remains unclear.

METHODS

A multicenter database of five regional hospitals was retrospectively reviewed for all patients with PAA undergoing open surgical repair. Data were collected on demographic information, operative details, medications, and postoperative outcomes. Kaplan-Meier curves were used to compare freedom from major adverse limb events (MALE) following GSV versus prosthetic bypass. Cox proportional hazards model was used to identify patient-level characteristics associated with MALE, which was defined as major ipsilateral limb amputation or reintervention for graft patency.

RESULTS

From 1999 to 2020, a total of 101 patients with PAA underwent open exclusion and bypass surgery. Median follow-up period was 4.2 years (interquartile range, 1.3-7.4 years), and complete data were available for 99 (98.0%) patients. The majority of patients were male (99.0%) and Caucasian (93.9%). Only 11.1% of procedures were emergent, with the remainder (88.9%) being elective. All patients underwent medial exposure with a below-knee popliteal bypass target (100%). Bypass conduits included GSV (69.7%), prosthetic conduit (28.3%), and 2 (2.0%) alternative conduits (one spliced arm vein, one cryopreserved vein). Patients undergoing prosthetic bypass were older (72 vs. 66 years, P = 0.001) and had similar rates of medical comorbidities. Compared with the GSV group, patients with prosthetic conduits were more frequently placed on postoperative anticoagulation (60.7% vs. 23.2%, P < 0.001). Conduit type did not impact postoperative complication rates (P = NS each). MALE rates were low overall (19.2% at 2 years), and similar when stratified by conduit type (log rank P = 0.47). On multivariable analysis, emergent bypass was associated with MALE (hazard ratio [HR] 5.73, 95% confidence interval [CI] 2.07-15.85, P < 0.001). Prosthetic conduit usage (HR 1.00, 95% CI, 0.40-2.51, P = 0.99) and postoperative anticoagulation (HR 1.02, 95% CI 0.42-2.50, P = 0.97) were not associated with MALE.

CONCLUSIONS

Open repair of PAA is associated with excellent long-term outcomes. Prosthetic bypass is a comparable alternative to autogenous conduit for below-knee popliteal bypass targets, and lack of suitable GSV should not prohibit open surgical repair when indicated.

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.

Early and long-term results of surgical treatment of popliteal artery aneurysms using a heparin-bonded expanded polytetrafluorethilene graft

BACKGROUND

The aim of the present study was to assess early and long-term results of open surgical interventions for popliteal artery aneurysms (PAAs) with the use of heparin-bonded expanded polytetrafluorethylene (HePTFE) in a single center, retrospective, non-comparative cohort study.

METHODS

A retrospective analysis of a prospectively maintained dataset, including 207 open interventions for PAAs between 2002 and 2022, was performed and 170 procedures carried on with the use of a HePTFE graft were found. Perioperative results were analyzed in terms of mortality, graft thrombosis and amputation rates. Follow-up results were analyzed in terms of survival, primary and secondary patency, freedom from amputation, freedom from reintervention with life-table analysis and Kaplan Meier curves. Follow-up results were considered as primary outcomes, whereas perioperative results were considered as secondary outcomes.

RESULTS

In 82 interventions (48%) the PAA was asymptomatic. In 140 cases a medial approach was used, while in 30 cases a posterior approach was preferred. The level of the distal anastomosis was the p3 tract of the popliteal artery in 89% of the cases. One perioperative death occurred; early thromboses occurred in eight cases and the overall perioperative amputation rate was 2.8%. The median duration of follow-up was 48 months (range 1-251). Estimated survival rate at 10 years was 55% (standard error, SE, 0.065). The 10-year rates of primary and secondary patency and freedom from amputation were 40.8% (SE 0.06), 47.6% (SE 0.065) and 93.4% (SE 0.04), respectively. The estimated freedom from reintervention rate at 10 years was 57% (SE 0.05).

CONCLUSIONS

The results of this large monocentric experience showed that open surgical repair of PAAs with HePTFE is a safe procedure, with low rates of perioperative complications, and excellent results in the long-term setting.

Popliteal pseudoaneurysm in a young patient with multiple hereditary exostosis

Multiple hereditary exostosis is an osteogenic disorder that causes outgrowths of cartilaginous bone tumors that are associated with adjacent neurovascular compressive injuries. We present the case of an adolescent male with multiple hereditary exostosis complicated by popliteal pseudoaneurysm formation who underwent excision of the osteochondroma and vein patch angioplasty repair of the artery. We highlight the rare association between this genetic disease and subsequent vascular complications and review the available literature of arterial complications of this disease.

Association Between Conduit Type and Outcomes After Open Repair of Popliteal Artery Aneurysms

INTRODUCTION

Prior studies have demonstrated acceptable midterm outcomes with prosthetic conduits for above-knee bypass for occlusive disease in patients with inadequate segment great saphenous vein (GSV). In this study we aimed to investigate whether this holds true for open repair of popliteal artery aneurysms (PAA).

METHODS

We queried the Vascular Quality Initiative data for patients who underwent open PAA repair (OPAR). We divided the cohort into three groups based on the conduit used: GSV, other autologous veins, or prosthetic graft. Study outcomes included primary patency, freedom from major amputation, amputation-free survival, and overall survival at 1 y. Kaplan-Meier survival estimates, log-rank tests and multivariable Cox regression were used to compare outcomes between study groups.

RESULTS

A total of 4016 patients underwent bypass for PAA from January 2010 to October 2021. The three cohorts were significantly different in many demographic and clinical characteristics. The adjusted odds of postoperative amputation among symptomatic patients were 3-fold higher for prosthetic conduits compared to the GSV (odds ratio, 3.20; 95% CI, 1.72-5.92; P < 0.001). For the 1-y outcomes, the adjusted risk of major amputation was almost 3-fold higher for patients with symptomatic disease undergoing bypass with prosthetic conduits (hazard ratio [HR], 2.97; 95% CI, 1.35-6.52; P = 0.007). When compared with GSV, prosthetic conduits were associated with 96% increased risk of death when used for repair in symptomatic patients (adjusted hazard ratio (aHR), 1.96; 95% CI, 1.29-2.97; P = 0.002) but no significant association with mortality in asymptomatic patients (aHR, 0.83; 95% CI, 0.37-1.87; P = 0.652). When compared with GSV, prosthetic conduits were associated with a 2-fold increased risk of 1-y major amputation or death when used for repair in symptomatic patients (aHR, 2.03; 95% CI, 1.40-2.94; P < 0.001) but no significant association with mortality in asymptomatic patients (aHR, 0.91; 95% CI, 0.42-1.98; P = 0.816). Comparing bypass with other veins to the GSV among patients with symptomatic disease, there was no statistically significant difference in major amputation risk (HR; 2.44; 95% CI, 0.55-10.82; P = 0.242) and no difference in the adjusted risk of all-cause mortality (aHR, 0.77; 95% CI, 0.26-2.44; P = 0.653). There were no differences in the adjusted risk of loss of primary patency comparing other veins to GSV (HR, 1.53; 95% CI, 0.85-2.76; P = 0.154) and prosthetic conduits to GSV (HR, 0.85; 95% CI, 0.57-1.26; P = 0.422).

CONCLUSIONS

This large study shows that among patients undergoing OPAR, 1-y primary patency does not differ between conduit types. However, prosthetic conduits are associated with significantly higher risk of amputation and death compared to GSV among symptomatic patients. Though non-GSV autologous veins are less often used for OPAR, they have comparably acceptable outcomes as GSV.

Limb salvage and survival after urgent surgical treatment of popliteal artery aneurysm

BACKGROUND

Popliteal artery aneurysms (PAAs) need urgent treatment in case of acute thrombosis, distal embolization, or rupture. Few data are available in the literature about the treatment results in these scenarios. The aim of the present study was to evaluate an 11-year multicenter experience in the urgent treatment of PAAs.

METHODS

All symptomatic PAAs surgically treated in two vascular centers between 2010 and 2021 were retrospectively analyzed. In the postoperative period periodical clinical and Duplex-Ultrasound evaluation were performed. The evaluated endpoint was the outcome of urgent PAAs treatment according to their clinical presentation. Statistical analysis was performed by Kaplan-Meier log-rank evaluation and multivariable Cox regression tests.

RESULTS

Sixty-six PAAs needed an urgent repair. Twelve (18%) patients had a PAA rupture and 54 (82%) had an acute limb ischemia (ALI) due to either distal embolization or acute thrombosis. Patients with ALI underwent bypass surgery in 51 (95%) cases, which was associated with preoperative thrombolysis in 18 (31%) cases. A primary major amputation was performed in 3 (5%) cases. The mean follow-up was 52 ± 21 months with an overall 5-year limb salvage of 83 ± 6%. Limb salvage was influenced only by the number of patent tibial arteries (pTA) [5-years limb salvage 0%, 86 ± 10%, 92 ± 8% and 100% in case of 0, 1, 2 or 3 pTA, respectively (P = .001)]. An independent association of number of pTA and limb loss was found [hazard ratio (HR): 0.14 (95% confidence interval (CI) 0.03-0.6), P = .001]. Overall 5-year survival was 71 ± 7%. Ruptured PAAs were associated with lower 5-year survival compared with the ALI group (48 ± 2% vs. 79 ± 7%, P = .001). The number of pTA (33 ± 20%, 65 ± 10%, 84 ± 10% and 80 ± 10% for 0, 1, 2 and 3 pTA, respectively, P = .001) and the thrombolysis (94 ± 6% vs. 62 ± 10%, P = .03) were associated with higher survival in patients with ALI. There was an independent association of number of pTA and long-term survival [HR 0.15 (95% CI 0.03-0.8), P = .03].

CONCLUSIONS

PAA rupture is the cause of urgent PAA treatment in almost one fifth of cases, and it is associated with lower long-term survival. ALI can benefit from thrombolysis, and long-term limb salvage and survival are associated with the number of pTA.

Indications for a "Surgery-First" Approach for the Treatment of Lower Extremity Arterial Disease

BACKGROUND

In recent years, there has been a tendency toward an "endovascular-first" approach for the treatment for femoropopliteal arterial disease. The purpose of this study is to determine if there are patients that are better served with an initial femoropopliteal bypass (FPB) rather than an endovascular attempt at revascularization.

METHODS

A retrospective analysis of all patients undergoing FPB between June 2006 - December 2014 was performed. Our primary endpoint was primary graft patency, defined as patent using ultrasound or angiography without secondary intervention. Patients with <1-year follow-up were excluded. Univariate analysis of factors significant for 5-year patency was performed using χ2 tests for binary variables. A binary logistic regression analysis incorporating all factors identified as significant by univariate analysis was used to identify independent risk factors for 5-year patency. Event-free graft survival was evaluated using Kaplan-Meier models.

RESULTS

We identified 241 patients undergoing FPB on 272 limbs. FPB indication was disabling claudication in 95 limbs, chronic limb-threatening ischemia (CLTI) in 148, and popliteal aneurysm in 29. In total, 134 FPB were saphenous vein grafts (SVG), 126 were prosthetic grafts, 8 were arm vein grafts, and 4 were cadaveric/xenografts. There were 97 bypasses with primary patency at 5 or more years of follow-up. Grafts patent at 5 years by Kaplan-Meier analysis were more likely to have been performed for claudication or popliteal aneurysm (63% 5-year patency) as compared with CLTI (38%, P < 0.001). Statistically significant predictors (using log rank test) of patency over time were use of SVG (P = 0.015), surgical indication of claudication or popliteal aneurysm (P < 0.001), Caucasian race (P = 0.019) and no history of COPD (P = 0.026). Multivariable regression analysis confirmed these 4 factors as significant independent predictors of 5-year patency. Of note, there was no statistical correlation between FPB configuration (above or below knee anastomosis, in-situ versus reversed saphenous vein) and 5-year patency. There were 40 FPBs in Caucasian patients without a history of COPD receiving SVG for claudication or popliteal aneurysm that had a 92% estimated 5-year patency by Kaplan-Meier survival analysis.

CONCLUSIONS

Long-term primary patency that was substantial enough to consider open surgery as a first intervention was demonstrated in Caucasian patients without COPD, having good quality saphenous vein, and who underwent FPB for claudication or popliteal artery aneurysm.

Observational study of endoluminal mural thrombotic apposition in popliteal artery aneurysm stenting and its relationship with stent-graft geometrical features

Introduction

The development of intrastent thrombosis is one of the mechanisms related to medium- to long-term failure of endovascular treatment of popliteal artery aneurysm. The present study aims to investigate possible links between the development of endoluminal mural thrombotic apposition in the stented zone (EMTS) with both geometrical features of stent-graft(s) and time of follow-up.

Methods

Patients with popliteal artery aneurysm who underwent endovascular treatment were recruited during the follow-up period. Segmentation of computed tomography angiography scan was performed to detect femoropopliteal artery lumen, leg bones, EMTS, and stent-graft(s). The following parameters were assessed: number, diameter, and length of stent-graft(s); and shape, volume, and length of thrombotic apposition within the stent(s). The spiral shape of the thrombotic apposition was evaluated as well.

Results

Eighteen male patients were recruited in the study. EMTS was observed in 13 of them (72%) during the follow-up analysis. An average of 1.8 ± 0.79 stents-grafts were implanted per patient with a median diameter and length of 6.2 (1.9) mm and 125 (50) mm, respectively. The percentage of the stent length where EMTS was present was 42.1 on average (interquartile range: 42.4%) with a mean volume of 206.8 mm3. A positive correlation was found between the length and volume of EMTS (R-squared = 0.71, p < 0.01). Moreover, EMTS had a helical shape in 8/13 patients, with 4/5 with counterclockwise rotation with stent-grafts in the left leg and 3/3 with clockwise direction treated in the right leg. A higher frequency of EMTS was observed in patients with longer follow-up and higher risk factors, as well.

Conclusions

EMTS is observed in most of the patients under analysis, especially in those with medium- to long-term follow-up. The pattern of such EMTS follows a helical shape having a direction that depends on which leg, right or left, is treated. Our results suggest a close surveillance of popliteal aneurysm stenting by follow-up examinations to control the onset and progression of EMTS.

Focus on the Most Common Paucisymptomatic Vasculopathic Population, from Diagnosis to Secondary Prevention of Complications

Middle-aged adults can start to be affected by some arterial diseases (ADs), such as abdominal aortic or popliteal artery aneurysms, lower extremity arterial disease, internal carotid, or renal artery or subclavian artery stenosis. These vasculopathies are often asymptomatic or paucisymptomatic before manifesting themselves with dramatic complications. Therefore, early detection of ADs is fundamental to reduce the risk of major adverse cardiovascular and limb events. Furthermore, ADs carry a high correlation with silent coronary artery disease (CAD). This study focuses on the most common ADs, in the attempt to summarize some key points which should selectively drive screening. Since the human and economic possibilities to instrumentally screen wide populations is not evident, deep knowledge of semeiotics and careful anamnesis must play a central role in our daily activity as physicians. The presence of some risk factors for atherosclerosis, or an already known history of CAD, can raise the clinical suspicion of ADs after a careful clinical history and a deep physical examination. The clinical suspicion must then be confirmed by a first-level ultrasound investigation and, if so, adequate treatments can be adopted to prevent dreadful complications.

Apolipoprotein E (ApoE) Rescues the Contractile Smooth Muscle Cell Phenotype in Popliteal Artery Aneurysm Disease

Popliteal artery aneurysm (PAA) is the most frequent peripheral aneurysm, primarily seen in male smokers with a prevalence below 1%. This exploratory study aims to shed light on cellular mechanisms involved in PAA progression. Sixteen human PAA and eight non-aneurysmatic popliteal artery samples, partially from the same patients, were analyzed by immunohistochemistry, fluorescence imaging, Affymetrix mRNA expression profiling, qPCR and OLink proteomics, and compared to atherosclerotic (n = 6) and abdominal aortic aneurysm (AAA) tissue (n = 19). Additionally, primary cell culture of PAA-derived vascular smooth muscle cells (VSMC) was established for modulation and growth analysis. Compared to non-aneurysmatic popliteal arteries, VSMCs lose the contractile phenotype and the cell proliferation rate increases significantly in PAA. Array analysis identified APOE higher expressed in PAA samples, co-localizing with VSMCs. APOE stimulation of primary human PAA VSMCs significantly reduced cell proliferation. Accordingly, contractile VSMC markers were significantly upregulated. A single case of osseous mechanically induced PAA with a non-diseased VSMC profile emphasizes these findings. Carefully concluded, PAA pathogenesis shows similar features to AAA, yet the mechanisms involved might differ. APOE is specifically higher expressed in PAA tissue and could be involved in VSMC phenotype rescue.

Characteristics of patients with multiple arterial aneurysms

Background: The aim of this retrospective cross-sectional observational study was to determine differences of patients with multiple arterial aneurysms to patients with single arterial aneurysms. Patients and methods: Patients with the diagnosis of an arterial aneurysm from January 2006 to January 2016 in the department of vascular surgery Heidelberg were investigated. Excluded were patients with hereditary disorders of connective tissue or systemic inflammatory disease, as well as other arterial pathologies than true aneurysms. Patients with multiple aneurysms (defined by at least four aneurysms) were compared to patients with single aneurysms concerning age at initial diagnosis, sex and affected arterial site. To verify the findings, a replication of the study was performed at a comparable institution. Results: Of 3107 patients with arterial aneurysms, 918 were excluded. Of the resulting 2189 patients, 1238 (56.6%) patients had a single, 808 (36.9%) two or three, and 143 (6.5%) at least four aneurysms (group mult-AA). Nine hundred seventy-two patients (44.4%) had a single abdominal aortic aneurysm (group sing-AAA). Age at initial diagnosis differed between mult-AA (66.7±9.5 y) and sing-AAA (69.1±8.6 y) (p=0.0338). Within mult-AA, 138 patients (96.5%) were male, compared with 865 patients (89.0%) in sing-AAA (p=0.0041). The most frequent aneurysm localization shifted from the abdominal aorta and its branches in patients with a single aneurysm (n=1029; 83.1%) to pelvic and leg arteries in patients with at least four aneurysms (n=318; 63.2%). The replication of the study at the department of vascular surgery Frankfurt confirmed the younger age at initial diagnosis in mult-AA (67.3±12.5 y) compared to sing-AAA (70.9±9.6 y) (p=0.0259) and the distribution shift toward the arteries below the aortic bifurcation in mult-AA. Conclusions: Patients with multiple aneurysms are younger at initial diagnosis and differ concerning aneurysm localization compared to patients with a single aneurysm.

Expanded Polytetrafluoroethylene Membranes for Vascular Stent Coating: Manufacturing, Biomedical and Surgical Applications, Innovations and Case Reports

Coated stents are defined as innovative stents surrounded by a thin polymer membrane based on polytetrafluoroethylene (PTFE)useful in the treatment of numerous vascular pathologies. Endovascular methodology involves the use of such devices to restore blood flow in small-, medium- and large-calibre arteries, both centrally and peripherally. These membranes cross the stent struts and act as a physical barrier to block the growth of intimal tissue in the lumen, preventing so-called intimal hyperplasia and late stent thrombosis. PTFE for vascular applications is known as expanded polytetrafluoroethylene (e-PTFE) and it can be rolled up to form a thin multilayer membrane expandable by 4 to 5 times its original diameter. This membrane plays an important role in initiating the restenotic process because wrapped graft stent could be used as the treatment option for trauma devices during emergency situations and to treat a number of pathological vascular disease. In this review, we will investigate the multidisciplinary techniques used for the production of e-PTFE membranes, the advantages and disadvantages of their use, the innovations and the results in biomedical and surgery field when used to cover graft stents.

Symptomatic Popliteal Artery Aneurysms in Recently SARS-CoV-2-Infected Patients: The Microangiopathic Thrombosis That Undermines Treatment

BACKGROUND

Arterial and venous thrombosis are complications in SARS-CoV-2-infected patients. The microangiopathic thrombosis in affected patients can compromise results in urgent limb revascularizations. Aim of our study is to report on the incidence of symptoms development in patients affected by popliteal artery aneurysm (PAA) and to analyze the effect of COVID-19 infection on outcomes.

METHODS

Data on patients surgically treated for PAA from the massive widespread of COVID-19 vaccine (March 2021) to March 2022 were prospectively collected. Factors considered for analysis were: presence of symptoms, aneurysm diameter and length, time from symptom onset and hospital referral, ongoing or recently COVID-19 infection. Outcomes measures were: death, amputation, and neurological deficit.

RESULTS

Between March 2021 and March 2022, 35 patients were surgically treated for PAA. Among them 15 referred to our hospital for symptomatic PAA and were urgently treated. Urgent treatments included both endovascular procedures and open surgeries. Nine out of 15 symptomatic patients had an ongoing or recently recovered COVID-19 infection. COVID-19 infection was strongly associated to symptoms development in patients affected by PAA and to surgical failure in those patients (OR 40, 95% CI 2.01-794.31, p = 0.005).

CONCLUSION

In our series, presence of COVID-19 infection was strongly associated to ischemic symptoms onset and to complications after urgent treatment in symptomatic patients.

Endoleak following endovascular repair of popliteal artery aneurysm: clinical outcome and contrast-enhanced ultrasound detection

BACKGROUND

Continued blood flow in the aneurysm sac after repair, also known as endoleak, can occur after both open and endovascular popliteal aneurysm repair (EPAR) with risk for aneurysm sac enlargement. Primary aims were to investigate aneurysm sac growth and the presence and classification of endoleak after EPAR using contrast-enhanced ultrasound (CEUS).

METHODS

Cross-sectional study of patients receiving EPAR with expanded polytetrafluorethylene (ePTFE) covered stent-grafts between 1^st of January 2009 and 1^st of February 2019 at a tertiary referral endovascular center. Patients were re-invited in 2021 and 31 legs were examined for endoleak using CEUS. Endoleaks were classified by a core-lab consisting of three CEUS-experienced physicians.

RESULTS

Median follow-up was 57 months (range 33-143 months). Endoleak was detected in 16 PAA, and categorized as type I (N.=3), type II (N.=10), type III (N.=1) or indeterminate (N.=2). Median maximal PAA diameter was 24 mm (range 15-55 mm) at the time of EPAR compared to 17 mm (range 6-43 mm) at follow-up (P<.001). Maximal aneurysm sac diameter was smaller at follow-up than at the index procedure in both PAAs with and without endoleak on CEUS (P=0.005 vs. P<0.001, respectively). There was no difference in PAA sac shrinkage at follow-up between patients with or without endoleak (P=0.28). Freedom from aneurysm sac growth was 97%.

CONCLUSIONS

CEUS was sensitive in endoleak detection after EPAR. Shrinkage of the PAA sac was found in both patients with and without endoleaks. CEUS appears useful for targeted examinations rather than routine surveillance after EPAR.

Antithrombotic Therapy for Aortic Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVES

The role of antithrombotic therapy in the management of aortic and peripheral aneurysms is unclear. This systematic review and meta-analysis aimed to assess the impact of antithrombotics on clinical outcomes for aortic and peripheral aneurysms.

METHODS

Medline, Embase, and CENTRAL databases were searched. Randomised controlled trials and observational studies investigating the effect of antithrombotic therapy on clinical outcomes for patients with any aortic or peripheral artery aneurysm were included.

RESULTS

Fifty-nine studies (28 with antiplatelet agents, 12 anticoagulants, two intra-operative heparin, and 16 any antithrombotic agent) involving 122 102 patients were included. Abdominal aortic aneurysm (AAA) growth rate was not significantly associated with the use of antiplatelet therapy (SMD -0.36 mm/year; 95% CI -0.75 - 0.02; p = .060; GRADE certainty: very low). Antithrombotics were associated with increased 30 day mortality for patients with AAAs undergoing intervention (OR 2.30; 95% CI 1.51 - 3.51; p < .001; GRADE certainty: low). Following intervention, antiplatelet therapy was associated with reduced long term all cause mortality (HR 0.84; 95% CI 0.76 - 0.92; p < .001; GRADE certainty: moderate), whilst anticoagulants were associated with increased all cause mortality (HR 1.64; 95% CI 1.14 - 2.37; p = .008; GRADE certainty: very low), endoleak within three years (OR 1.99; 95% CI 1.10 - 3.60; p = .020; I² = 60%; GRADE certainty: very low), and an increased re-intervention rate at one year (OR 3.25; 95% CI 1.82 - 5.82; p < .001; I² = 35%; GRADE certainty: moderate). Five studies examined antithrombotic therapy for popliteal aneurysms. Meta-analysis was not possible due to heterogeneity.

CONCLUSIONS

There was a lack of high quality data examining antithrombotic therapy for patients with aneurysms. Antiplatelet therapy was associated with a reduction in post-intervention all cause mortality for AAA, whilst anticoagulants were associated with an increased risk of all cause mortality, endoleak, and re-intervention. Large, well designed trials are still required to determine the therapeutic benefits of antithrombotic agents in this setting.

Open Repair versus Endovascular Repair in The Treatment of Symptomatic Popliteal Artery Aneurysms

OBJECTIVE

Endovascular and open surgical modalities are currently used to treat popliteal artery aneurysms (PAA). However, there is limited data on the comparative durability of both repairs to guide physicians especially in the treatment of patients presenting symptomatic. We aimed to study the comparative effectiveness of endovascular PAA repair (EPAR) versus open PAA repair (OPAR).

METHODS

The vascular quality initiative (VQI)-Medicare linked database was queried for patients with symptomatic PAA who underwent OPAR or EPAR from January 2010 to December 2018. Kaplan-Meier estimates, log rank tests and multivariable Cox proportional hazard regression were employed to study the outcomes of amputation free survival (AFS), freedom from major amputation, and overall survival in 2 years following the index procedure.

RESULTS

A total of 1375 patients were studied, of which 23.7% (n=326) were treated with EPAR. Patients treated with OPAR were younger, less likely to have coronary artery disease (CAD) and chronic kidney disease (CKD), but more likely to be smokers and to present with acute lower extremity ischemia. OPAR patients had better 2-year AFS (84.5% vs. 72.5%, P<0.001) and overall survival (86.2% vs 74.7%, P<0.001). Freedom from major amputation at 2 years was comparable between EPAR and OPAR (95.5% vs 97.7%, P=0.164) in the overall cohort. Within the sub cohort of patients with acute limb ischemia, freedom from major amputation was significantly higher for OPAR compared to EPAR (97.4% vs. 90.6%, P=0.021). After adjustment for confounders, OPAR was associated with decreased risk of amputation or death (aHR, 0.62; 95%CI, 0.48-0.80; P<0.001) and mortality (aHR, 0.63; 95%CI, 0.48-0.81; P<0.001) at 2 years. OPAR and EPAR had comparable adjusted risk of 2-year major amputation in the overall cohort. However, for patients presenting with acute limb ischemia OPAR was associated with 72% lower risk of 2-year major amputation compared to EPAR (aHR, 0.28; 95%CI, 0.10-0.83; P=0.021).

CONCLUSION

In this multi-institutional observational study of symptomatic popliteal aneurysms, OPAR was associated with significantly better amputation free and overall survival compared to EPAR. For patients with acute ischemia, OPAR was associated with reduced risk of amputation. These findings suggest that OPAR may be superior to EPAR in the treatment of symptomatic PAA. A consideration of OPAR as first line definitive treatment for symptomatic PAA patients who are good surgical candidates is suggested.

Arterial Aneurysm Localization Is Sex-Dependent

The aim of this study was to investigate sex-dependent aneurysm distributions. A total of 3107 patients with arterial aneurysms were diagnosed from 2006 to 2016. Patients with anything other than true aneurysms, hereditary connective tissue disorders or vasculitides (n = 918) were excluded. Affected arterial sites and age at first aneurysm diagnosis were compared between women and men by an unpaired two-tailed t-test and Fisher’s exact test. The study sample consisted of 2189 patients, of whom 1873 were men (85.6%) and 316 women (14.4%) (ratio m:w = 5.9:1). Men had considerably more aneurysms in the abdominal aorta (83.4% vs. 71.1%; p < 0.001), common iliac artery (28.7% vs. 8.9%; p < 0.001), internal iliac artery (6.6% vs. 1.3%; p < 0.001) and popliteal artery (11.1% vs. 2.5%; p < 0.001). In contrast, women had a higher proportion of aneurysms in the ascending aorta (4.4% vs. 10.8%; p < 0.001), descending aorta (11.1% vs. 36.4%; p < 0.001), splenic artery (0.9% vs. 5.1%; p < 0.001) and renal artery (0.8% vs. 6.0%; p < 0.001). Age at disease onset and further aneurysm distribution showed no considerable difference. The infrarenal segment might be considered a natural border for aneurysm formation in men and women suspected to have distinct genetic, pathophysiologic and ontogenetic factors. Screening modalities for women at risk might need further adjustment, particularly thoracic cross-sectional imaging complementation.

Real-world data of popliteal artery aneurysm treatment. Analysis of the POPART registry

OBJECTIVE

Popliteal artery aneurysm (PAA) is a rare disease with a prevalence of 0.1-1%. Within the last years, endovascular repair of PAA (ER) has been performed more frequently despite the lack of high-level evidence compared to open surgery (OR). In 2014, the POPART registry was initiated to validate current treatment options in PAA repair.
 METHOD: POPART is a multinational multicenter registry for peri- and postoperative outcome of endovascular and open PAA repair. Data sets are recorded by the online survey tool "SurveyMonkey®". Regular monitoring and plausibility checks of the data sets are performed to ensure reliability. The aim of this study is to present results of the POPART registry, with data of 41 centers.
 RESULTS: From June 2014 to August 2019, a total of 794 cases were recorded in the PAA registry. OR was performed in 662 patients and ER in 106 patients; 23 Patients were treated conservatively. Four of the 106 patients with primary ER underwent conversion to OR. ER patients were significantly older (ER x˜= 71 vs. OR x˜= 67 (p<0.05). There were no other significant differences in demographics or comorbidities and aneurysm morphology between the two groups. 50.3% patients in the OR group were symptomatic; in the ER group 29.2% (p<0.05). Emergency treatment for acute ischemia, critical ischemia or rupture was necessary in 149 patients (22.5%) in the OR group vs. 11 patients (10.3%) in the ER group.
Most frequent complications after surgery were impaired wound healing (OR n=47, 7.1%; ER n=3, 2.8%, p>0.05) and major bleeding (OR n=26, 3.9%; ER n=3, 2.8%, p>0.05). In-hospital length of stay (= 10d [3-65] OR vs. x˜=7d [1-73] ER) was significantly higher in the OR group. Overall patency was 83.2% vs. 44.7% (OR/ER, p<0.005) after 12 months and 74.2% vs. 29.1% (OR/ER, p<0.005) after 24 months. There was a significantly poorer outcome for prosthetic graft compared to autologous vein in the OR group (71.4% vs. 88.1% 12-month primary patency).
 CONCLUSION: 
 In order to evaluate new treatment techniques such as endovascular repair (ER) for PAA, real world data is of essential importance. This analysis of the first results for the POPART registry shows good perioperative results for endovascular treatment of PAA in asymptomatic patients with good outflow vessels. The perioperative complication rate is low and the postoperative hospital stay is shorter than after OR. However, the patency rates after 12 and 24 months are low in the ER group compared to patients treated with open repair. More follow-up data is required for further interpretation; the completion of the data sets in the registry is ongoing.

A systematic review and meta-analysis of treatment and natural history of popliteal artery aneurysms

OBJECTIVE

To summarize the best available evidence comparing open vs endovascular popliteal artery aneurysm (PAA) repair. We also summarized the natural history of PAAs to support of the Society for Vascular Surgery guidelines.

METHODS

We searched MEDLINE, EMBASE, Cochrane databases, and Scopus for studies of patients with PAAs treated with an open vs an endovascular approach. We also included studies of natural history of untreated patients. Studies were selected and appraised by pairs of independent reviewers. A meta-analysis was performed when appropriate.

RESULTS

We identified 32 original studies and 4 systematic reviews from 2191 candidate references. Meta-analysis showed that compared with the endovascular approach, open surgical repair was associated with higher primary patency at 1 year (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.41-3.12), lower occlusion rate at 30 days (OR, 0.41; 95% CI, 0.24-0.68) and fewer reinterventions (OR, 0.28; 95% CI, 0.17-0.45), but a longer hospital stay (standardized mean difference, 2.16; 95% CI, 1.23-3.09) and more wound complications (OR, 5.18; 95% CI, 2.19-12.26). There was no statistically significant difference in primary patency at 3 years (OR, 1.38; 95% CI, 0.97-1.97), secondary patency (OR, 1.59; 95% CI, 0.84-3.03), mortality at the longest follow-up (OR, 0.49; 95% CI, 0.21-1.17), mortality at 30 days (OR, 0.28; 95% CI, 0.06-1.36), or amputation (incidence rate ratio, 0.85; 95% CI, 0.56-1.31). The certainty in these estimates was, in general, low. Studies of PAA natural history suggest that thromboembolic complications and amputation develop at a mean observation time of 18 months and they are frequent. One study showed that at 5 years, approximately one-half of the patients had complications.

CONCLUSIONS

This systematic review provides event rates for outcomes important to patients with PAAs. Despite the low certainty of the evidence, these rates along with surgical expertise and anatomic feasibility can help patients and surgeons to engage in shared decision-making.