A systematic review and meta-analysis of treatment and natural history of 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.

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.

Popliteal artery aneurysm ultrasound criteria for reporting characteristics

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Feasibility of Encord Artificial Intelligence Annotation of Arterial Duplex Ultrasound Images

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

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.

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.

The Management of Patients with Popliteal Artery Aneurysms Presenting with Acute Limb Ischemia

INTRODUCTION

Endovascular popliteal artery aneurysm (PAA) repair has acceptable outcomes compared to open repair for elective therapy. Endovascular repair for urgent PAA causing acute limb ischemia (ALI) has not been well studied. This project compares outcomes of urgent endovascular and open repair of PAA with ALI.

METHODS

The Vascular Quality Initiative database for peripheral vascular interventions and infrainguinal bypass were reviewed for PAA with ALI from 2010 to 2021. Only patients entered as having symptoms of ALI in the PVI module and ALI as indication in the infrainguinal bypass module were included. In addition, patients undergoing elective treatment were excluded and the sample analyzed was restricted to patients undergoing urgent and emergent open and endovascular repair. Patient demographics and comorbidities as well as procedural details were compared between the two groups. Perioperative complications up to 30 days were compared as well as long-term outcomes including major amputation and mortality at one year.

RESULTS

Urgent PAA repair for ALI constituted 10.5% (N=571) of all PAA. Most urgent repairs were open (80.6%, n=460) with 19.4% (n=111) endovascular. The proportion of endovascular repair significantly increased from 16.7% in 2010 to 85.7% in 2021. Patients undergoing endovascular repair were older (71.2 ± 12.5 vs 68.0 ± 11.8, p=0.011) than patients undergoing open repair. They were also more likely to have coronary artery disease (32.4% vs 21.7%, p=0.006). Open PAA repair was associated with more bleeding complications (20.8% vs 2.7%, p<0.001), longer post-op length of stay (8.1 ± 9.3 days vs 4.9 ± 5.6 days, p<0.001), and less likelihood of discharge to home (64.9% vs 70.3%, p=0.051). Perioperative major amputation rate was 7.5% with no difference between the two treatment strategies up to one year. However, patients receiving endovascular repair had higher inpatient (1.1% vs 0%, p<0.001), 30-day (6.3% vs 0.4%, p<0.001), and 1-year (16.5% vs 8.4%. P=0.02) mortality. Multivariable regression analysis suggested that endovascular repair was possibly associated with increased 30-day mortality, but not 1-year mortality.

CONCLUSION

Endovascular PAA has exponentially increased from 2010 to 2021. Endovascular repair is associated with decreased complications and hospital length of stay. The increased perioperative mortality seen in this group is likely due to selection bias.

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.

Comparisons of outcomes of open surgery versus endovascular intervention for thrombotic popliteal artery aneurysm with acute lower limb ischemia: a systematic review

Background

Thrombotic popliteal artery aneurysm (PAA) with acute lower limb ischemia (ALI) is a serious disease leading to amputation. The choice of emergency procedures is not clearly defined, and the difference in therapeutic efficiency between open surgery and endovascular intervention is still unclear.

Method

We conducted a comprehensive search through PubMed, Wiley Online Library and ScienceDirect. According to the predefined inclusion and exclusion criteria, eligible articles were screened out, and all relevant data were extracted for further analysis. Our study was designed and developed based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guideline. We critically assessed all included articles by Joanna Briggs Institute (JBI) Critical Appraisal Checklists and the Methodological Index for Non-Randomized Studies (MINORS).

Result

A total of 29 articles (1338 patients/1387 limbs) were included in the study. After a 1-year follow-up, the primary patency rate of the open surgery group was significantly lower than that of the endovascular intervention group (72.65 vs. 81.46%, P = 0.004), but without significant difference in the secondary patency rate (86.19 vs. 86.86%, P = 0.825). The limb salvage rate of the open surgery group was also significantly lower (83.07 vs. 98.25%, P < 0.001). After the 2-year follow-up, the primary patency rate of the open surgery group was still significantly lower (48.57 vs. 59.90%, P = 0.021).

Conclusion

The outcome of endovascular intervention was better than that of open surgery especially in the 1-year limb salvage rate and primary patency rate at the 1-year and 2-year follow-ups.

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.

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.