Long-term Outcomes and Sac Volume Shrinkage after Endovascular Popliteal Artery Aneurysm Repair

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.

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.

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.

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.

Popliteal artery aneurysms treatments: early midterm results of the use of endovascular stent grafts

Background/aim

Popliteal artery aneurysms (PAAs) are abnormal bulgings, which account for 70% of all peripheral artery aneurysms. They are usually asymptomatic. In this study, we present our long-term results of endovascular stent grafts in the treatment of PAA in the light of literature data.

Material and methods

A total of 63 legs of 63 patients with PAA, who were treated with endovascular techniques in our clinic between July 2010 and July 2019, were retrospectively analyzed. All patients underwent color Doppler ultrasound (DUS), magnetic resonance angiography (MRA), or computed tomography angiography (CTA) to identify the diameter and length of PAAs, vessel tortuosity, the presence and degree of thrombus, and diameter in the healthy landing zone and to visualize tibioperoneal vascular structures. A Viabahn stent graft was inserted in all patients.

Results

57 patients (90.5%) were males with a mean age of 76.35 ± 7 years. 24 patients (38.1%) were symptomatic, while 11 patients (17.5%) had a concomitant abdominal aortic aneurysm (AAA). The mean follow-up period was 46.05 ± 25.01 months. The primary patency rate was 79.3%. A graft thrombosis was observed in 13 patients (20.6%) during a mean follow-up period of 8.31 ± 5.91 months. The number of distal arteries was significantly lower in the patients with thrombosis than those without.

Conclusions

Endovascular treatment of PAA using stentgrafts is safe in selected cases. However, it is reasonable to avoid endovascular treatment due to an increased risk for thrombosis in patients with a low number of patent distal arteries or impaired distal flow.

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

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms (PAAs) leverage the work of a panel of experts chosen by the Society for Vascular Surgery to review the current world literature as it applies to PAAs to extract the most salient, evidence-based recommendations for the treatment of these patients. These guidelines focus on PAA screening, indications for intervention, choice of repair strategy, management of asymptomatic and symptomatic PAAs (including those presenting with acute limb ischemia), and follow-up of both untreated and treated PAAs. They offer long-awaited evidence-based recommendations for physicians taking care of these patients.

Endovascular treatment of popliteal artery aneurysms has comparable long-term outcomes to open repair with shorter lengths of stay

OBJECTIVE

During the past two decades, the treatment of popliteal artery aneurysms (PAAs) has undergone a transformation. Although open surgical repair (OR) has remained the reference standard for treatment, endovascular repair (ER) has become an attractive alternative for select patient populations. The objective of the present study was to compare the outcomes of OR vs ER of PAAs at a single institution.

METHODS

We performed a retrospective review of the medical records for all patients who had undergone repair for PAAs from 1998 to 2017. The baseline patient, anatomic, and operative characteristics and outcomes were compared between the OR and ER cohorts. Intervention and treatment were at the discretion of the surgeon.

RESULTS

From 1998 to 2017, 64 patients had undergone repair of 73 PAAs at our tertiary care center. Of the 69 patients (73 PAAs), 29 (33 PAAs) had undergone OR and 35 (40 PAAs) had undergone ER. When comparing the two cohorts, no statistically significant differences were found in the demographic characteristics such as age, gender, or number of runoff vessels. Significantly more patients in the ER group (n = 21; 53%) than in the OR group (n = 7; 21%) had had hyperlipidemia (P = .008) and a previous carotid intervention (6% vs 0%; P = .029). Overall, the presence of symptoms was similar between the two groups. However, the OR group had a significantly higher number of patients who had presented with acute ischemia (P = .01). The length of stay was significantly shorter for the ER cohort (mean, 1.8 days; range, 1-11 days) than for the OR group (mean, 5.4 days; range, 2-13 days; P < .0001). No significant difference was found in the primary or secondary patency rates between the two groups. In the ER group, good runoff (two or more vessels) was a positive predictor for primary patency at 1 year (odds ratio, 3.36; 95% confidence interval, 1.0-11.25). However, it was not in the OR group. Postoperative single and/or dual antiplatelet therapy did not affect primary patency in either cohort.

CONCLUSIONS

The results of our study have demonstrated that ER of PAAs is a safe and durable option with patency rates comparable to those with OR and a decreased length of stay, with good runoff a positive predictor for primary patency in the ER cohort.

Results After Open and Endovascular Repair of Popliteal Aneurysm: A Matched Comparison Within a Population Based Cohort

OBJECTIVE

To identify factors affecting the outcome after open surgical (OSR) and endovascular (ER) repair of popliteal artery aneurysm (PA) in comparable cohorts.

METHODS

A matched comparison in a national, population based cohort of 592 legs treated for PA (2008 - 2012), with long term follow up. Registry data from 899 PA patients treated in 2014 - 2018 were analysed for time trends. The 77 legs treated by ER were matched, by indication, with 154 legs treated with OSR. Medical records and imaging were collected. Analysed risk factors were anatomy, comorbidities, and medication. Elongation and angulations were examined in a core lab. The main outcome was occlusion.

RESULTS

Patients in the ER group were older (73 vs. 68 years, p = .001), had more lung disease (p = .012), and were treated with dual antiplatelet therapy or anticoagulants more often (p < .001). The hazard ratio (HR with 95% confidence intervals) for occlusion was 2.69 (1.60 - 4.55, p < .001) for ER, but 3.03 (1.26 - 7.27, p = .013) for poor outflow. For permanent occlusion, the HR after ER was 2.47 (1.35 - 4.50, p = .003), but 4.68 (1.89 - 11.62, p < .001) for poor outflow. In the ER subgroup, occlusion was more common after acute ischaemia (HR 2.94 [1.45 - 5.97], p = .003; and poor outflow HR 14.39 [3.46 - 59.92], p < .001). Larger stent graft diameter reduced the risk (HR 0.71 [0.54 - 0.93], p = .014). In Cox regression analysis adjusted for indication and stent graft diameter, elongation increased the risk (HR 1.020 per degree [1.002 - 1.033], p = .030). PAs treated for acute ischaemia had a median stent graft diameter of 6.5 mm, with those for elective procedures being 8 mm (p < .001). Indications and outcomes were similar during both time periods (2008 - 2012 and 2014 - 2018).

CONCLUSION

In comparable groups, ER had a 2.7 fold increased risk of any occlusion, and 2.4 fold increased risk of permanent occlusion, despite more aggressive medical therapy. Risk factors associated with occlusion in ER were poor outflow, smaller stent graft diameter, acute ischaemia, and angulation/elongation. An association between indication, acute ischaemia, and small stent graft diameter was identified.

Patient-specific computational fluid dynamics of femoro-popliteal stent-graft thrombosis

Intra-stent thrombosis is one of the major failure modes of popliteal aneurysm endovascular repair, especially when the diseased arterial segment is long and requires overlapping stent-grafts having different nominal diameters in order to accommodate the native arterial tapering. However, the interplay between stent sizing, post-operative arterial tortuosity, luminal diameter, local hemodynamics, and thrombosis onset is not elucidated, yet. In the present study, a popliteal aneurysm was treated with endovascular deployment of two overlapped stent-grafts, showing intra-stent thrombosis at one-year follow-up examination. Patient-specific computational fluid-dynamics analyses including straight- and bent-leg position were performed. The computational fluid-dynamics analysis showed that the overlapping of the stent-grafts induces a severe discontinuity of lumen, dividing the stented artery in two regions: the proximal part, affected by thrombosis, is characterized by larger diameter, low tortuosity, low flow velocity, low helicity, and low wall shear stress; the distal part presents higher tortuosity and smaller lumen diameter promoting higher flow velocity, higher helicity, and higher wall shear stress. Moreover, leg bending induces an overall increase of arterial tortuosity and reduces flow velocity promoting furtherly the luminal area exposed to low wall shear stress.

Symptomatic type I endoleak following popliteal artery aneurysm repair

A case of a symptomatic type Ib endoleak following popliteal artery aneurysm repair with successful interventional therapy introduces a short review of the limited literature to this relevant potential complication. Illustration of important factors supporting endoleak formation after endovascular popliteal artery repair and recommendation of a consequent surveillance are discussed.

Early and mid-term results in the endovascular treatment of popliteal aneurysms with the multilayer flow modulator

Background The endovascular approach became an alternative to open surgical treatment of popliteal artery aneurysm over the last few years. Heparin-bonded stent-grafts have been employed for endovascular popliteal artery aneurysm repair, showing good and stable results. Only few reports about the use of multilayer flow modulator are available in literature, providing small patient series and short follow-up. The aim of this study is to report the outcomes of patients with popliteal artery aneurysm treated with the multilayer flow modulator in three Italian centres. Methods We retrospectively analysed a series of both symptomatic and asymptomatic patients with popliteal artery aneurysm treated with the multilayer flow modulator from 2009 to 2015. Follow-up was undertaken with clinical and contrast-enhanced ultrasound examinations at 1, 6 and 12 months, and yearly thereafter. Computed tomography angiography was performed in selected cases. Primary endpoints were aneurysm sac thrombosis; freedom from sac enlargement and primary, primary-assisted and secondary patency during follow-up. Secondary endpoints were technical success, collateral vessels patency, limb salvage and aneurysm-related complications. Results Twenty-three consecutive patients (19 males, age 72 ± 11) with 25 popliteal artery aneurysms (mean diameter 23 mm ± 1, 3 symptomatic patients) were treated with 40 multilayer flow modulators during the period of the study. Median follow-up was 22.6 ± 16.7 months. Complete aneurysm thrombosis occurred in 92.9% of cases (23/25 cases) at 18 months. Freedom from sac enlargement was 100% (25/25 cases) with 17 cases of aneurysm sac shrinkage (68%). At 1, 6, 12 and 24 months, estimated primary patency was 95.7%, 87.3%, 77% and 70.1%, respectively. At the same intervals, primary-assisted patency was 95.7%, 91.3%, 86% and 86%, respectively, and secondary patency was 100%, 95.7%, 90.3% and 90.3%, respectively. Technical success was 100%. The collateral vessels patency was 72.4%. Limb salvage was 91.4% at 24-month follow-up. One multilayer flow modulator fracture was reported in an asymptomatic patient. Conclusions Multilayer flow modulator seems a feasible and safe solution for endovascular treatment of popliteal artery aneurysms in selected patients.

Endovascular Treatment of Chronic Occluded Popliteal Artery Aneurysm

Critical limb ischemia may be the consequence of chronic occlusion of an aneurysm of popliteal artery. Endovascular repairs have the potential to be less invasive than open surgery and to allow the treatment, during the same procedure, of occlusive infrapopliteal diseases achieving a better distal outflow. Eleven patients with occluded popliteal artery aneurysm (PAA) underwent an endovascular repair of PAA using a new technique, by positioning of a Viabahn graft inside a bare nitinol stent, deployed at the level of aneurysm with the intent to avoid distal embolization and to assure an external scaffold for the Viabahn graft. Immediate success rate was 100%. A peroneal artery embolization occurred in 1 patient (9%) and was successfully treated by stent implantation. Four (36.4%) patients needed a below-the-knee revascularization to achieve at least 1 vessel line to the foot. Mean postoperative hospital stay was 2.6 days. At 24-month follow-up, primary patency, target lesion revascularization, and major amputation rates were 82%, 9%, and 0%, respectively. All patients are still alive at last follow-up visit. The endovascular repair with the combined use of a bare metal stent and Viabahn graft resulted in a low incidence of distal embolization and major amputation rate, with an excellent 24-month patency rate, and may offer a safe alternative to open surgery for the treatment of occluded PAAs.

Patients with abdominal aortic aneurysm have a high prevalence of popliteal artery aneurysms

Patients with abdominal aortic aneurysms (AAA) are more prone to develop popliteal artery aneurysms (PAA), but the prevalence is not well known. Our aim was to investigate the prevalence of PAA in patients with AAA, and to determine whether a certain risk factor profile is more commonly found in patients with concurrent aneurysms. All AAA patients (ICD code I71.3, I71.4) attending the outpatient clinic at the Karolinska University Hospital between 2011 and 2013 were included in the study cohort ( n=465); 48% (225) had been subjected to an ultrasound or computed tomography scan of their popliteal arteries. In these patients, three definitions of PAA were considered (⩾ 10.5, ⩾ 12, ⩾ 15 mm), although the overall analysis is based on PAA ⩾ 12 mm. The mean age was 70.7 years (SD 7.5), 89% were men, and the mean AAA diameter was 47 mm (SD 14). The prevalence of PAA was 19% ( n=43) by definition ⩾ 12 mm, and 11% ( n=25) with 15 mm. Claudication was more frequently found in AAA patients with PAA than patients without PAA. Sensitivity between clinical examination and radiology was 26%, and the specificity for clinical examination was 90%. In conclusion, owing to the high prevalence of PAA in AAA patients, described by us and others, the low cost and risks associated with ultrasound and the poor sensitivity at clinical examination, all women and men with AAA should undergo one radiological examination of their popliteal arteries.

Popliteal Artery Aneurysm Repair in the Endovascular Era: Fourteen-Years Single Center Experience

To compare outcomes of popliteal artery aneurysm (PAA) repair by endovascular treatment, great saphenous vein (GSV) bypass, and prosthetic bypass.Single center retrospective analysis of patients presenting PAA from 2000 to 2013. Patients were divided into endovascular treatment (group A); GSV bypass (group B); and prosthetic graft bypass (group C). Outcomes were technical success, perioperative mortality, and morbidity. Survival, primary and secondary patency, and freedom from reintervention rate were estimated. Differences in ankle-brachial index (ABI), in-hospital length of stay (InH-Los), red blood cell (RBC) transfusion, and limb loss were reported. Mean follow-up was 49 (median: 35; 1-145; SD 42) months.Sixty-seven patients were included; 25 in group A, 28 in group B, and 14 in group C. PAA was symptomatic in 23 (34%) cases. Technical success was 100%. No perioperative death occurred. Three (4.5%) perioperative complications were reported with no significant difference between groups (P = 0.866). Five-years estimated survival was 78%. Estimated 5-years primary patency for groups A, B, and C was 71%, 81%, and 69%, respectively (P = 0.19). Estimated 5-years secondary patency for groups A, B, and C was 88%, 85%, and 84% (P = 0.85). Estimated 5-years freedom from reintervention for groups A, B, and C was 62%, 84%, and 70%, respectively (P = 0.16). A significant difference between preoperative ABI versus postoperative ABI was observed (P = 0.001). InH-LoS was significantly shorter in group A (P < 0.001). RBC transfusions were required significantly less in group A when compared to group C (P = 0.045). Overall limb salvage was achieved in all but 1 patient.PAA repair has good early and long-term outcomes with different treatment options. Endovascular treatment was not inferior to surgical repair with a reduced InH-LoS and RBC transfusion. It can be successfully employed even in nonelective setting. A randomized controlled trial with long-term follow-up and appropriate patient inclusion criteria is necessary to compare these 3 treatment options.

Two Decades of Endovascular Repair of Popliteal Artery Aneurysm--A Meta-analysis

OBJECTIVE/BACKGROUND

Over the last two decades endovascular repair (EVR) of popliteal artery aneurysms has emerged as a treatment alternative to conventional open surgical repair (OSR). The aim of this review was to evaluate the safety and efficiency of each repair method, comparing the following outcomes after EVR and OSR: (i) primary patency; (ii) operating time; (iii) length of hospital stay; (iv) peri-operative complications; (v) limb salvage; and (vi) patient survival.

METHODS

The PubMed and Cochrane Central Register of Controlled Trials were searched for publications that compared outcomes after EVR and OSR (last search November 2014). Randomized controlled trials (RCTs), prospective and retrospective observational cohort studies were included. The quality of studies was evaluated using the Newcastle-Ottawa scale and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Random effect models were employed to estimate odds ratios (ORs), mean differences, and hazard ratios (HRs).

RESULTS

One RCT combined with a prospective cohort study and four retrospective cohort studies with an overall total of 652 cases (236 EVR, 416 OSR) were identified. GRADE quality of evidence was low or very low for all outcomes. After a median follow up of 33 months, patients who received EVR showed equal primary patency rates to patients who received OSR (HR 1.46, 95% confidence interval [CI] 0.92-2.33). Lengths of operation and hospitalization were significantly shorter following EVR; rates of 30 day graft thrombosis (OR 3.16, 95% CI 1.31-7.62) and 30 day re-intervention (OR 2.15, 95% CI 1.02-4.55) were significant higher for patients who received EVR compared with those who received OSR. There was no effect on mortality (OR 2.31, 95% CI 0.37-14.49) or limb loss (OR 0.59, 95% CI 0.16-2.15).

CONCLUSION

EVR of popliteal artery aneurysm showed mid-term results comparable to open surgery and appears to be a safe alternative to OSR. However, the existing empirical evidence base is too fragmentary to draw firm conclusions. Further research and the introduction of population based registries will be needed to allow reliable evaluation of EVR.