Open Conversion After Endovascular Aortic Aneurysm Repair: A Single-Center Experience

Systematic review and meta-analysis of incidence, indications, and outcomes of early open conversions after EVAR for abdominal aortic aneurysms

INTRODUCTION

The purpose of this study is to report incidence, indications, and outcomes of early open conversions (EOC) after endovascular aortic repair (EVAR), defined as surgical conversion performed within 30 days from the initial EVAR.

EVIDENCE AQUISITION

A systematic review of the literature was performed (database searched: PubMed, Web of Science, Scopus, Cochrane Library; last search April 2023). Articles reporting EOC after EVAR comprising at least five patients were included. Meta-analyses of proportions were performed using a random-effects model.

EVIDENCE SYNTHESIS

Seventeen non-randomized studies, published between 1999 and 2022, were included. A total of 35,970 patients had previously undergone EVAR, of these 438 patients underwent EOC. Estimated incidence of EOC was 1.4% (95% CI 1.1-1.4; I2=81.66%). Specifically, in the works published before 2010 the incidence was 1.8% (95% CI 1.3-2.4; I2=74.25) while for subsequent ones it was 0.9% (95% CI 0.6-1.1; I2=69.82). Weighted mean age was 74.91 years (95% CI 72.42-77.39; I2=83.11%). Estimated rate of cause determining EOC were: access issue in 27.7% of patients (95% CI 13.8-41.6; I2=88.14%), incorrect placement of the endograft in 20.1% (95% CI 10.2-30.0; I2=76,9%), problems with "delivery system" in 9.0% (95% CI 4.9-13.1; I2=0%), aorto-iliac rupture in 8.6% (95% CI 4.5-12.6; I2=0%), endoprosthesis migration in 7.9% of cases (95% CI 3.3-12.4; I2=22.96%), failure in engaging the contralateral gate in 4.8% (95% CI 1.6-8; I2=0%), "kinking" or "twisting" of endoprosthesis in 3.3% (95% CI 0.6-5.9; I2=0%), graft thrombosis in 3.2% (95% CI 0.6-5.7; I2=0%), type Ia endoleak in 2.9% (95% CI 0.4-5.4; I2=0%), type III endoleak in 2.8% (95% CI 0.3-5.3; I2=0%) and endograft infection in 2.7% (95% CI 0.3-5.2; I2=0%). Intraoperative conversion rate was 91.1% (95% CI 85.8-96.4; I2=66.01%). Early mortality rate after EOC was 14.5% (95% CI 9.1-19.9; I2=48.31%). Mean length of stay (LOS) was 11.94 days (95% CI 6.718-17.172; I2=92.34%).

CONCLUSIONS

The incidence of EOC seems to decrease over time. Causes of EOC were mainly related to access problems and incorrect positioning of the endograft. Most of the EOC were performed intraoperatively carrying a high mortality rate.

Open Surgical Conversion After Endovascular Aortic Aneurysm Repair: A Systematic Review and Meta-Analysis

Endovascular aneurysm repair (EVAR) is a preferred treatment for abdominal aortic aneurysms, though it comes with complications such as endoleaks and graft infections that may necessitate late open conversion (LOC). This systematic review and meta-analysis, drawing on studies from PubMed/MEDLINE, Embase, and the Cochrane Database of Systematic Reviews, aimed to evaluate the incidence, outcomes, and factors leading to LOC after EVAR. The analysis of 11 selected studies revealed a 5.3% incidence of LOC, with a patient cohort predominantly male (79%) and an average age of 73.5 years. The interval between initial EVAR and LOC was 35.1 months on average, with the Excluder device most frequently necessitating LOC. A notable 68% of endovascular salvage attempts before LOC failed. The study highlighted rupture and type I endoleak as the primary reasons for urgent LOC, which exhibited a 10-fold higher mortality rate compared to elective LOC. Elective LOC procedures had a 30-day mortality rate similar to primary elective open aneurysm repairs. These findings underscore the importance of vigilant post-EVAR patient monitoring and suggest that the methodological quality of underlying research should be considered in interpreting these results.

Partial and complete explantation of aortic endografts in the modern era

OBJECTIVE

Despite the progressive advancement of devices for endovascular aortic repair (EVAR), endografts continue to fail, requiring explant. We present a single-institutional experience of EVAR explants, characterizing modern failure modes, presentation, and outcomes for partial and complete EVAR explantation.

METHODS

A retrospective analysis was performed of all EVARs explanted at an urban quaternary center from 2001 to 2020, with one infected endograft excluded. Patient and graft characteristics, indications, and perioperative and long-term outcomes were analyzed. Partial versus complete explants were performed per surgeon discretion without a predefined protocol. This process was informed by patient risk factors; asymptomatic, symptomatic, or ruptured aneurysm presentation; and anatomical or intraoperative factors, including endoleak type.

RESULTS

From 2001 to 2020, 52 explants met the inclusion and exclusion criteria. More than one-half (57.7%) were explants of EVAR devices placed at outside institutions, designated nonindex explants. Most patients were male (86.5%), the median age was 74 years (interquartile range, 70-78 years). More than one-half (61.5%) were performed in the second decade of the study period. The most commonly explanted grafts were Gore Excluder (n = 9 grafts), Cook Zenith (n = 8), Endologix AFX (n = 7), Medtronic Endurant (n = 5), and Medtronic Talent (n = 5). Most grafts (78.8%) were explanted for neck degeneration or sac expansion. Five were explanted for initial seal failure, five for symptomatic expansion, and seven for rupture. The median implant duration was 4.2 years, although ranging widely (interquartile range, 2.6-5.1 years), but similar between index and nonindex explants (4.2 years vs 4.1 years). Partial explantation was performed in 61.5%, with implant duration slightly lower, 3.2 years versus 4.4 years for complete explants. Partial explantation was more frequent in index explants (68.2% vs 56.7%). The median length of stay was 8 days. The median intensive care unit length of stay was 3 days, without significant differences in nonindex explants (4 days vs 3 days) and partial explants (4 days vs 3 days). Thirty-day mortality occurred in two nonindex explants (one partial and one complete explant). Thirty-day readmission was similar between partial and complete explants (9.7% vs 5.0%), without accounting for nonindex readmissions. Long-term survival was comparable between partial and complete explants in Cox regression (hazard ratio, 2.45; 95% confidence interval, 0.79-7.56; P = .12).

CONCLUSIONS

Explants of EVAR devices have increased over time at our institution. Partial explant was performed in more than one-half of cases, per operating surgeon discretion, demonstrating higher blood loss, more frequent acute kidney injury, and longer intensive care unit stays, however with comparable short-term mortality and long-term survival.

The failing endograft-A systematic review of aortic graft explants and associated outcomes

OBJECTIVE

The prominent use of endovascular stent grafts in the management of abdominal aortic aneurysms is associated with increased descriptions of late complications such as graft infection and endoleaks, which can confer significant morbidity and mortality. Failed endovascular management of late complications often requires open conversion and graft explantation. This systematic review sought to highlight the peri- and post-operative course of patients undergoing aortic graft explants to inform readers of the associated morbidity and mortality of patients undergoing this procedure.

METHODS

The review was conducted in accordance with PRISMA guidelines. A search of the PubMed, Google Scholar and Ovid MEDLINE databases from January 1995 to April 2021 was performed with a combination of MeSH terms pertaining to endovascular aneurysm repair and open conversion. Articles were screened and included based on pre-determined selection criteria.

RESULTS

A total of 818 studies were identified, with 41 meeting inclusion criteria. These studies examined a total of 1324 patients, 84.3% of whom were male with a mean age of 74 years at explantation. Mean time to graft explantation was 36 months, with a mean aneurysm size of 66 mm. The majority of aortic explants were performed for persistent endoleaks (68%), and 10% for infection. There was high morbidity with the procedure, with high rates of post-operative complications (mean, 37%) and 30-day mortality (11%). The most common complications included renal (15%), respiratory (12%) and cardiac (9%). Most explanted grafts were first-generation endografts. Morbidity and mortality rates were reduced in patients undergoing elective explants compared to emergent procedures (3.3% compared to 43.4%).

CONCLUSION

Aortic graft explant remains a highly co-morbid procedure, with high rates of peri- and post-operative complications and mortality. The number of explant procedures reported over the past 25 years has increased, reflecting the prominent use of EVAR in the management of AAAs. Whilst remaining a highly co-morbid procedure, patients undergoing elective explants had markedly reduced rates of mortality and morbidity compared to emergent explants. Thus, clinical focus should be on identifying patients who require graft explantation early to perform these procedures in an elective setting.

Management of Nellix migration and type Ia endoleak from proximal endovascular aneurysm sealing relining to late open conversion

BACKGROUND

Despite promising early results, mid-term failures of the Nellix endovascular aneurysm sealing (EVAS) system (Endologix Inc, Irvine, Calif) have been reported at higher than expected rates. The management of proximal endoleaks and migration differs from those after conventional endovascular aortic aneurysm repair (EVAR) owing to the peculiar design of the Nellix device. In the present study, we report a monocentric experience in the management of EVAS complications using various techniques. We also performed a comprehensive review of the relevant literature on both open surgical and endovascular management of proximal failure of EVAS from the MEDLINE database.

METHODS

We retrospectively analyzed the reinterventions for type Ia endoleak and migration after elective infrarenal EVAS at our institution. We collected preoperative, intraoperative, and follow-up data. Open and endovascular techniques are described. Overall survival, aortic-related mortality, and the technical success rate (rate of exclusion of endoleaks) with endovascular techniques were the primary outcomes.

RESULTS

We performed 101 infrarenal elective EVAS procedures from 2013 to 2018. Of the 101 patients, 20 (19.8%) had required reintervention for proximal sealing failure. The indications were type Ia (Is2, Is3) endoleak, migration >5 mm, sac expansion >5 mm, and secondary rupture. Of the 20 patients, 6 (30%) were treated with endovascular techniques-2 with a chimney Nellix-in-Nellix application and 4 with proximal relining with a covered stent. The remaining 14 patients (70%) were treated with late open conversion (OC). The average time from EVAS to reintervention was 36.1 months (range, 3-65 months). Six patients (30%) had undergone OC in an emergent setting because of secondary rupture. The technical success rate for the patients treated with endovascular reinterventions was 100%. The 30-day mortality was 20% (4 of 20), all emergent cases (four of six emergent repairs; 67%). The overall survival for the 20 patients was 75% (n = 15) at a mean follow-up of 15.1 months (range, 2-47 months). One patient had died after 7 months of non-aortic-related causes.

CONCLUSIONS

The high reintervention rate of the Nellix graft mandates careful evaluation for its further use with the revised instructions for use, and it should not be used off-label. OC remains the strategy of choice when managing Nellix proximal sealing failures in fit patients. Chimney Nellix-in-Nellix application and transcatheter embolization are feasible alternative techniques. Proximal relining also appears to be an effective alternative to more complex interventions, although it requires further studies for validation.

Open Conversion After Endovascular Aneurysm Sealing: Technical Features and Clinical Outcomes in 44 Patients

Purpose

To evaluate the technical features and clinical results after open conversion for complications following endovascular aneurysm sealing (EVAS).

Materials and Methods

From July 2013 to February 2020, 44 patients (mean age 72±8 years; 36 men) underwent an open conversion due to EVAS complications in a single center. Data were collected on patient characteristics, reasons for conversion, characteristics and duration of the procedure, condition of the polymer, blood loss, time in the intensive care unit (ICU), and intra/postoperative complications. The main outcome measure was mortality at 30 days and in follow-up. Data are presented as the median (IQR) and absolute range.

Results

On average, the open conversion took place 3 years after the initial EVAS implantation [median 37 months (IQR 23, 50); range 0–64]. Most patients were converted due migration (82%), aneurysm growth (77%), and/or endoleak (75%), with 21 patients (48%) having all 3 events. Less frequent diagnoses were aneurysm rupture (n=7), aortic infection (n=3), technical failure during implantation (n=2), and graft thrombosis (n=1). The majority of patients (n=26) were asymptomatic and converted electively, but 9 were operated on urgently and 9 emergently (7 late rupture and 2 due to technical failure). The median procedure duration was 178 minutes (IQR 149, 223; range 87–417), the median blood loss was 1100 mL (IQR 600, 2600; range 300–5000). Polymer degradation was mentioned in the operative reports of 18 cases (41%). Patients stayed a median of 3 days (IQR 2, 7; range 1–35) in the ICU, while the median length of stay in the hospital was 14 days (IQR 10, 20; range 0–93). The 30-day mortality was 23% (n=10). During a median follow-up of 3 months (IQR 0, 11; range 0–38), no additional deaths occurred, but 12 patients suffered from an adverse event. There were 3 cases of wound dehiscence after laparotomy, 2 cases of leg ischemia, 2 cases of renal failure, and individual cases of urinary obstruction, urinoma, paralytic ileus, gastrointestinal bleeding, and postoperative delirium. A non-elective setting was associated with a significantly increased mortality of 33% in urgent cases and 56% in emergent cases (p=0.007). Based on these results an algorithm for the management of EVAS complications was developed.

Conclusion

The significantly increased mortality associated with nonelective conversions highlights the need for active surveillance. The presented algorithm offers a structured tool to avoid emergency conversions.

State of the art and meta-analysis of secondary open aortic procedure after abdominal endovascular aortic repair

BACKGROUND

Secondary open aortic procedures (SOAP) treat complications of endovascular aneurysm repair, when further endovascular options are exhausted. We aimed at depicting the state of the art of SOAP with high-level evidence.

METHODS

A systematic review of the SOAP literature, with a meta-analysis of its outcomes (primary outcome operative mortality; secondary outcome major morbidity) and metaregression of risk factors for mortality (PROSPERO 42017075631).

RESULTS

Twenty-eight studies (1093 patients) were elected for analysis. SOAP was performed within the same hospitalization of or 30 days from domestic endovascular aneurysm repair (early SOAP) in 0.2% of the patients (85/40,256), and in a nonelective setting in 24.3% (95% confidence interval, 21.8-26.9). Most frequent indications were endoleak (44.4%; 95% confidence interval, 41.4-47.3) and rupture (12.7%; 95% confidence interval, 10.4-15.1). The most common procedures were infrarenal aortic replacement (85.2%; 95% confidence interval, 82.6-87.7) with high use of supravisceral clamping (suprarenal, 25% [95% confidence interval, 21.9-28.1] and supraceliac, 20.7% [95% confidence interval, 17.8-23.6]), and axillobifemoral bypass with stent explant (6.9%; 95% confidence interval, 5.1-8.7). Operative mortality (in-hospital or 30-day) was 10.9% (95% confidence interval, 8.7-13.5). The most frequent morbidities were respiratory (11.4%; 95% confidence interval, 8.1-15.9) and renal (9.5%; 95% confidence interval, 8.1-15.9). Risk factors for mortality were supravisceral clamping (Z = 3.007; Q = 9.044; P = .003) and nonelective status (Z = 3.382; Q = 11.440; P = .001).

CONCLUSIONS

Endoleak is the main indication for SOAP, which mostly consists of infrarenal aortic replacement. Risk factors for operative mortality are nonelective status and supravisceral clamping.

Explant of aortic stent grafts following endovascular aneurysm repair

Background

Failure of endovascular aneurysm repair may require explant of the stent graft in a subset of patients. We sought to assess outcomes in a cohort of patients undergoing explant of endovascular aneurysm repair in both emergency and elective settings.

Methods

Patients undergoing explant of endovascular aneurysm repair were identified from a prospectively maintained database, with additional information obtained through retrospective analysis of medical records.

Results

Over a 21-year period, 1997–2018 (May), there were 597 endovascular aneurysm repair procedures performed in our institution for abdominal aortic aneurysm. There were 19 endovascular aneurysm repair explants; five of these were referrals from other vascular centres. The median age was 73 years (range 46–81). The median length of time from insertion to explant was 39.2 months (range 0–153). Indications for elective explant were type Ia endoleak (n = 4), type 1b endoleak (n = 1), type II endoleak with increasing sac size (n = 1), type I/III endoleak (n = 1), type IV endoleak (n = 1), and increasing sac size without evident endoleak (type V, n = 2). The remaining nine cases were emergency procedures, with four patients presenting with rupture post endovascular aneurysm repair, four patients presenting with acute stent thrombosis, of which one also had a type 1a endoleak and one aorto-enteric fistula. There were no mortalities in the elective group and three mortalities in the emergency group (0 vs 33.3%, p = 0.087). Overall 30-day mortality was 15.8%

Conclusion

Explant of aortic stent grafts can be associated with high mortality and morbidity rates, especially in the emergent setting. Patient and device selection and post-operative surveillance remain vitally important to optimise outcomes post endovascular aneurysm repair.

Delayed open conversion after endovascular aortic repair

AIM

We present the clinical outcomes of patients who underwent delayed (>30 days) open surgical repair after endovascular aortic aneurysm repair.

METHODS

All patients receiving delayed open repair of infrarenal and juxtarenal aortic aneurysms after endovascular repair from July 2001 to December 2017 were retrospectively reviewed. Patients' baseline characteristics, indications for delayed open conversion, and time between endovascular repair and open conversion are described. Early outcomes included operative approach, morbidity, and mortality. Midterm outcomes included survival.

RESULTS

Twenty-two (3.3%) of 667 patients with prior infrarenal endovascular aortic aneurysm repair had delayed open conversion (20 elective and 2 emergency). The time from endovascular repair to open conversion was 60 ± 36 months. The indications were 6 (27%) type Ia endoleaks, 6 (27%) type II endoleaks with enlarging sac size, 2 (9%) endotensions, 7 (32%) unknown types of endoleak, and 1 (5%) graft infection. The 7 minutes unknown endoleaks were confirmed as lumbar leaks in 4 cases and fabric leaks in 3. Operative time was 222 ± 48 min with blood loss of 2211 ± 2057 mL. Hospital stay after conversion was 12 ± 8 days. There was no 30-day mortality. Estimated survival rates were 96%, 91%, 86%, 79% and 57% at 1, 2, 3, 4, and 5 years postoperatively.

CONCLUSION

Delayed conversion to open surgery after endovascular aortic aneurysm repair by endograft explantation appears to be safe with good short- and mid-term outcomes. With careful preoperative assessment, open conversion remained a realistic and viable option in patients with failed endovascular treatment.

Late open conversion after endovascular repair of abdominal aneurysm failure: Better and easier option than complex endovascular treatment

AIM

Conversion to open repair becomes the last option in case of endovascular repair of abdominal aneurysm failure, when radiological interventional procedures are unfeasible. While early conversion to open repair generally derives from technical errors, aetiopathogenesis and results of late conversion to open repair often remain unclear.

METHODS

We report data from our Institute's experience on late conversion to open repair. Twenty-two late conversion to open repairs out of 435 consecutive patients treated during a 18 years period, plus two endovascular repair of abdominal aneurysms performed in other centres, are analysed. The indication for conversion to open repair was aneurysm enlargement because of type I, type III, type II endoleak and endotension. Even if seven cases (23%) had shown an initial aneurysmal shrinkage, in a later phase, the sac began to enlarge again. In 12 patients, conversion to open repair was the last chance after unsuccessful secondary endovascular procedures.

RESULTS

Three cases (12.5%) were treated in emergency. Aortic cross-clamping was only infrarenal in 10 cases, only or temporarily suprarenal in 14 and temporarily supraceliac in 9 cases, for 19 total and 5 partial endograft excisions. Two patients died for Multiple Organ Failure (MOF), on 42nd (endovascular repair of abdominal aneurysm infection) and 66th postoperative day. No other conversion to open repair-related deaths or major complications were revealed by follow-up post-conversion to open repair (mean: 68 months ranging from 24 to 180 months).

CONCLUSION

Late conversion to open repair is often an unpredictable event. It represents a technical challenge: specifically, the most critical point is the proximal aortic clamping that often temporarily excludes the renal circulation. In our series, conversion to open repair can be performed with a low rate of complications. In response to an endovascular repair of abdominal aneurysm failure, before applying complex procedures of endovascular treatment, conversion to open repair should be taken into account.

The First Case of a Nellix Sac-Anchoring Endoprosthesis Removal for Aortoenteric Fistula

The Nellix device (Endologix, Irvine, CA), has been designed with a brand new concept to seal the abdominal aortic aneurysms, minimizing endoleaks and reducing reinterventions. We present the first open conversion of a Nellix endograft due to aortoduodenal fistula of a 74-year-old male patient treated for an abdominal aortic aneurysms of 62-mm diameter.

Late open conversion after endovascular abdominal aortic aneurysm repair

OBJECTIVE

This study determined the incidence, the surgical details, and the outcome of late open conversion after failed endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm.

METHODS

A review of English-language medical literature from 1991 to 2014 was conducted using the PubMed and EMBASE databases to find all studies involving late conversion after EVAR for abdominal aortic aneurysm. The search identified 26 articles encompassing 641 patients (84% men; median age, 73.5 years).

RESULTS

Mean interval from the initial implantation was 38.5 ± 10.7 months. The cumulative single-center open conversion rate was 3.7%. The indications for late open conversion included endoleak in 62.4%, infection in 9.5%, migration in 5.5%, and thrombosis in 6.7%. Operations were urgent in 22.5% of the patients. The 30-day mortality was 9.1%. Mortality rates were different between elective (3.2%) and nonelective patients (29.2%). Five aneurysm-related deaths (1.5%) and two graft infections (0.6%) occurred during a median follow-up of 26.4 months (range, 5-50.2 months).

CONCLUSIONS

The number of patients with failed EVAR and without further options for endovascular salvage is growing. Endoleak remains the most important weakness of EVAR as the leading cause of late open conversion. Such procedures, although technically demanding, are associated with relatively low mortality rates when performed electively. Open repair still represents a valuable solution for many patients with failed EVAR.

A new risk-scoring model for predicting 30-day mortality after repair of abdominal aortic aneurysms in the era of endovascular procedures

Purpose

To propose a new, multivariable risk-scoring model for predicting 30-day mortality in individuals underwent repair of abdominal aortic aneurysms (AAA).

Methods

Four hundred eighty-five consecutive patients who underwent AAA repair from January 2000 to December 2010 were included in the study. Univariate and multivariate analyses were performed to evaluate the risk factors, and a risk-scoring model was developed.

Results

Multivariate analysis identified three independent preoperative risk factors associated with mortality, and a risk-scoring model was created by assigning an equal value to each factor. The independent predictors were location of the AAA, rupture of AAA, and preoperative pulmonary dysfunction. The multivariable regression model demonstrated moderate discrimination (c statistic, 0.811) and calibration (Hosmer-Lemeshow test, P = 0.793). The observed mortality rate did not differ significantly from that predicted by our risk-scoring model.

Conclusion

Our risk-scoring model has excellent ability to predict 30-day mortality after AAA repair, and awaits validation in further studies.

Fungal infection of aortic Endograft because of Aspergillus fumigatus

A 59-year-old male, referred to our center with a ruptured aortic aneurysm, underwent urgent endovascular repair and femoro-femoral crossover bypass. An endograft infection because of Aspergillus fumigatus occurred about 20 days after surgery. We removed the endograft and femoral prosthesis and we then performed an aorto-bi-iliac bypass with autogenous reversed superficial femoral veins. Five days after surgery, the patient died. Microbiological examination and postmortem examination showed the presence of A. fumigatus in femoral prosthesis, aortic wall, and periaortic exudate.