Outcomes of Late Open Conversion after Endovascular Abdominal Aneurysm Repair

Late open conversion: a reliable solution for endoleak management after endovascular aortic aneurysm repair - a single center experience and literature review

BACKGROUND/OBJECTIVES

Despite the efficacy of endovascular approaches for most secondary interventions post-endovascular aortic aneurysm repair (EVAR), a small proportion of patients need open conversion (OC) procedures. We shared our experience regarding patient outcomes after late OCs post-EVAR. We also performed a literature review of data published on this topic.

PATIENTS, MATERIALS AND METHODS

Medical records of patients who underwent late OCs post-EVAR at a Public Hospital in Germany (2017-2019) were retrospectively analyzed. OC involved total or partial endograft removal followed by aortic reconstruction. Preoperative patients' characteristics, indications for OC, and intra-∕post-operative outcomes were assessed. Studies published in English (2014-2024) on OCs post-EVAR complications were descriptively analyzed.

RESULTS

Six patients underwent late OCs throughout the study (males: 66.67%; age [mean±standard deviation]: 66.50±2.89 years). Grafts were excised after a median of 72 months (range: 24-132 months), with 2∕6 (33.33%) urgent removals and 4∕6 (66.67%) elective. 4∕6 (66.67%) patients underwent complete removal, and 2∕6 (33.33%) were partial. Clamping site was suprarenal in 3∕6 (50.00%) patients, supraceliac in 2∕6 (33.33%), and infrarenal in 1∕6 (16.67%). Technical success was 100%, with 32 minutes mean clamping time and 1.67 L blood loss. Median follow-up was 13 months. No aneurysm growth was observed, and implanted grafts functioned well. 1∕6 (16.67%) patients died during the postoperative intensive care unit stay. Seven studies were included in our review. The 30-day mortality post-OCs was 6.2-10.0% in elective setting and up to 40% in urgent.

CONCLUSIONS

Late OC can be a reliable procedure for managing endoleak post-EVAR. Its success relies on accurate preoperative assessment and surgical expertise.

Open Conversion with Explantation of Stent Grafts After Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

BACKGROUND

Although endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is widely used worldwide, the fact that it is associated with increased rates of reintervention has been considered a problem. This study aimed to analyze the outcomes of primary open AAA repair and open conversion with explantation of stent grafts after EVAR.

METHODS

In this retrospective study, we enrolled 1,120 patients (open repair, n = 664; EVAR, n = 456) who underwent AAA repair at Kobe University from 1999 to 2019. Of the 664 patients who underwent open repair, 121 (patients who underwent primary open repair (POR) as a concomitant procedure and patients with ruptured AAA) were excluded from the study. The outcomes of POR were compared with those of open conversion with explantation of stent grafts.

RESULTS

Of the 543 patients who underwent open repair, 513 underwent POR and 30 underwent open conversion with explantation of stent grafts. The operation time for POR was significantly less than that for open conversion with explantation. During surgery, patients who underwent open conversion with explantation required significantly more transfusions of red cell concentrate, fresh frozen plasma, and platelet concentrate than those who underwent POR. Overall, 30 patients who underwent open conversion with explantation required a total of 48 reinterventions before surgery. Hospital mortality rates were 0.7% and 0% in the POR and open conversion with explantation groups, respectively (P = 0.62). Although overall survival at 5 years in the POR group was significantly better than that in the open conversion with explantation group (89.3 ± 1.7% vs. 79.5 ± 9.6%; P = 0.01), there were no significant differences between the 2 groups regarding the freedom from aortic event (hospital death, reintervention, and aortic death). According to the multivariate analysis, open conversion with explantation was not an independent risk factor for late death. There were 20 patients who were hesitant to undergo OCE, although we recommended OCE. In a subgroup analysis, the overall mean cost borne by patients who underwent EVAR was approximately 2.3 times higher compared with that borne by patients who underwent POR.

CONCLUSIONS

Although demanding, both early and long-term outcomes of OCE have been favorable in our present study. OCE is highly recommended in patients with persistent sac enlargement after EVAR.

Endotension Following Endovascular Aneurysm Repair: Retrospective Review of Treatment and Clinical Outcome

Purpose

: Endotension is a rare late complication characterized by an increase in sac size without any type of endoleak following endovascular aortic aneurysm repair (EVAR). Due to its rarity, few studies have demonstrated the mechanism behind and the management of endotension. In this study, we aimed to better understand the treatment and the long-term outcome of endotension in a single-center cohort.

Materials and Methods

: This study was designed for a retrospective review of the patients diagnosed with endotension between January 2006 and December 2017. The study patients were categorized into two groups (primary versus secondary) based on the presence of any type of endoleak before the diagnosis of endotension. We collected data related to endotension treatment, intraoperative findings, and long-term outcomes.

Results

: In a cohort of 15 patients diagnosed with endotension following EVAR, eight were classified into the primary endotension (PE) group without prior endoleak, and seven exhibited secondary endotension (SE). Among the eight PE patients, endovascular intervention for a preemptive purpose was conducted in six patients; however, three (50%) showed continuous sac expansion and finally received open conversion. Overall, eight patients (five in PE and three in SE) underwent open conversion, and one (12.5%) presented with an undetected endoleak during the operative findings. Postoperative morbidity was observed in three patients with no operative mortality.

Conclusion

: Endotension can be managed initially through simple observation for changes on serial images, along with preemptive endovascular intervention. However, surgical intervention should be considered for patients with specific indications including continuous aneurysm sac enlargement, presence of symptoms, suspicions of migration of stent-graft with endoleak, and infection.

Outcomes of Late Partial Conversion With Graft Replacement for Sac Enlargement After Endovascular Abdominal Aortic Aneurysm Repair

PURPOSE

Outcomes of late open conversion with graft replacement for enlargement after endovascular aortic repair remain unclear. Here, we report the outcomes of graft replacement after endovascular aortic repair.

MATERIALS AND METHODS

Fourteen patients who underwent graft replacement after endovascular aneurysm repair between November 2016 and October 2022 were included. Graft replacement was indicated in cases of rupture and enlargement of the aneurysm sac and when reintervention with endovascular therapy could not be performed.

RESULTS

The mean age at graft replacement was 80 ± 7 years. The follow-up period from endovascular aortic repair to graft replacement was 73 ± 41 months. The endoleaks that caused enlargement of the aneurysm sac were type I in 8 patients and type II in 6 patients. Ruptures were observed in 5 patients. One patient had paraplegia as a postoperative complication, and 2 patients died within 30 days. Morbidity and mortality were observed in cases of rupture, and no morbidity or mortality was observed in any elective surgery cases.

CONCLUSION

Late open conversion with graft replacement after endovascular aortic repair is a feasible elective surgery. However, morbidity and mortality have been observed in cases of rupture.

CLINICAL IMPACT

In elective surgery, postoperative outcomes are good for late open conversion with graft replacement after endovascular aortic repair. On the other hand, morbidity and mortality were observed in case of rupture. Therefore, it is important to perform elective surgical reintervention at the appropriate time.

Surgical Treatment of Sac Enlargement Due to Type II Endoleaks Following Endovascular Aneurysm Repair

An aneurysm sac enlargement caused by type II endoleak (T2EL) following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms may cause serious complications such as rupture. Consequently, methods that preoperatively prevent or postoperatively treat T2EL have been employed. When significant aneurysm enlargement occurs due to persistent T2EL, embolization is first performed through several access points. However, although these endovascular reinterventions have a high technical success rate and are safe, their effectiveness remains questionable. When such endovascular procedures fail to stabilize sac enlargement, open surgical conversion (OSC) becomes the last-resort treatment option. We review several strategies of OSC for the repair of T2EL following EVAR. Among the three main OSC procedures, namely, complete endograft removal, partial endograft removal, and complete endograft preservation, partial endograft removal under infrarenal clamping was considered the most appropriate owing to its less invasiveness and durability.

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.

Multicentre Comparison between Open Conversions and Semi-Conversions for Late Endoleaks after EVAR

OBJECTIVES

The aim of this study is to compare early and follow-up outcomes of late open conversions (LOC, with complete or partial endograft explantation) and semi-conversions (SC, with endograft preservation) after EVAR in a multicentre experience.

MATERIALS AND METHODS

All-LOC and SC performed from 1997 to 2020 in 11 vascular centres were compared. Endograft infections or thrombosis were excluded. Primary endpoints were early mortality, and long-term survival estimates. Secondary endpoints were differences in: postoperative complication rates, conversion-related complications during follow-up.

RESULTS

In the considered period, 347 patients underwent surgery for EVAR complications. Among these, 270 were operated on for endoleaks (222 LOC, 48 SC). The 2 groups were homogeneous in terms of ASA score (3.2±0.7 LOC, 3±0.5 SC; P=.128) and main endograft characteristics (suprarenal fixation, bifurcated/aorto-uni-iliac configuration). Mean age was 75±8 at LOC and 79±7 at SC (P=.009). Reasons for LOC were: 62.2% (138/222) type I endoleak, 21.6% (48/222) type II, 7.7% (17/222) type III, 8.5% (19/222) endotension. Indications for SC were: 64.6% (31/48) type II endoleak, 33.3% (16/48) type I, 2.1% (1/48) type III. Thirty-day mortality was 12.2% (27/222) in the LOC group, and 10.4% (5/48) in the SC group (P=.73). Postoperative complication rate was higher in the LOC group (45.5% vs. 29.2%, P=.04). The estimated survival rate after LOC was 80% at 1 year and 64% at 5 years; after SC 72% at 1 year and 37% at 5 years (log-rank P=.01). During the median follow-up of 21.5 months (inter-quartile range 2.4-61), an endoleak after SC was found in the 38.3% of the cases; sac growth was recorded in the 27.7% of SC patients.

CONCLUSIONS

SC have an early benefit over LOC in terms of reduced postoperative complications, but a significantly inferior mid-term survival. The high rates of persistent and/or recurrent endoleaks reduce SC durability.

Endovascular recanalization and remodeling of abdominal aorta stent graft chronic total occlusion after failed extra-anatomic bypass surgery

OBJECTIVES

Chronic total occlusion (CTO) of the EVAR graft is a rare and serious complication. Traditionally, surgical intervention with prosthetic graft replacement or bypass graft implantation is performed. However, there are limited data in endovascular era.

METHODS

We present a case of a 68-year-old male with a history of late EVAR graft occlusion treated with multiple surgical interventions (femorofemoral crossover, extra-anatomic bypass surgery, and thrombectomy) five years ago. Color Doppler ultrasound (CDUS) and computed tomography (CT) angiography revealed thrombosis of the entire bypass graft. Endovascular recanalization and remodeling of the abdominal stent graft CTO was performed with a combination of bare stents and stent grafts. Rupture of the stent graft occurred on the right limb. A second covered stent was placed.

RESULTS

At 12-month follow-up, the patient was symptom free. Color Doppler ultrasound surveillance showed patent aortic stent graft and downstream arteries.

CONCLUSIONS

Endovascular recanalization of aortic stent graft CTO is a viable option in patients with failed bypass graft.

A Canadian multicenter experience describing outcomes after endovascular abdominal aortic aneurysm repair stent graft explantation

BACKGROUND

Most studies describing the outcomes after endovascular abdominal aortic aneurysm repair (EVAR) explantation have been from single, high-volume, centers. We performed a multicenter cross-Canadian study of outcomes after EVAR stent graft explantation. Our objectives were to describe the outcomes after late open conversion and EVAR graft explantation at various Canadian centers and the techniques and outcomes stratified by the indication for explant.

METHODS

The Canadian Vascular Surgery Research Group performed a retrospective multicenter study of all cases of EVAR graft explantation at participating centers from 2003 to 2018. Data were collected using a standardized, secure, online platform (RedCap [Research Electronic Data Capture]). Univariate statistical analysis was used to compare the techniques and outcomes stratified the indication for graft explantation.

RESULTS

Patient data from 111 EVAR explants collected from 13 participating centers were analyzed. The mean age at explantation was 74 years, the average aneurysm size was 7.5 cm, and 28% had had at least one instructions for use violation at EVAR. The average time between EVAR and explantation was 42.5 months. The most common indication for explantation was endoleak (n = 66; type Ia, 46; type Ib, 2; type II, 9; type III, 2; type V, 7), followed by infection in 20 patients; rupture in 18 patients (due to type Ia endoleak in 10 patients, type Ib in 1, type II in 1, type III in 2, and type V in 1), and graft thrombosis in 7 patients. The overall 30-day mortality was 11%, and 45% of the patients had experienced at least one major perioperative complication. Mortality was significantly greater for patients with rupture (33.3%) and those with infection (15%) compared with patients undergoing elective explantation for endoleak (4.5%; P = .003). The average center volume during the previous 15 years was 8 cases with a wide range (2-19 cases). A trend was seen toward greater mortality for patients treated at centers with fewer than eight cases compared with those with eight or more cases (19% vs 9%). However, the difference did not reach statistical significance (P = .23). Overall, 41% of patients had undergone at least one attempt at endovascular salvage before explantation, with the highest proportion among patients who had undergone EVAR explantation for endoleak (51%). Only 22% of patients with rupture had undergone an attempt at endovascular salvage before explantation.

CONCLUSIONS

The performance of EVAR graft explantation has increasing in Canada. Patients who had undergone elective explantation for endoleak had lower mortality than those treated for either infection or rupture. Thus, patients with an indication for explanation should be offered surgery before symptoms or rupture has occurred. A trend was seen toward greater mortality for patients treated at centers with lower volumes.