Secondary conversion due to failed endovascular abdominal aortic aneurysm repair

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.

Two decades of experience in explantation and graft preserving strategies following primary endovascular aneurysm repair and lessons learned

Objectives

We aim to scrutinize our evolving re-intervention strategies following primary endovascular aortic aneurysm repair (EVAR) - EVAR GORE SalvAge Fabric Technique (ARAFAT), aortic sac double breasting with endograft preservation, and stent-graft explantation.

Methods

We performed 1,555 aortic interventions over the study period, including 910 EVARs. Factors associated with the need for reintervention and the likelihood of chronic fabric fatigue failure (CFFF) were investigated. Using conventional and innovative diagnostic modalities with Prone contrASt enHanced computed tomography Angiography (PASHA), 136 endoleaks (ELs) were identified (15 type I, 98 type II; 18 type III; 5 type IV).

Results

Forty-four (4.84%) patients underwent re-intervention post-primary EVAR; 18 ARAFATs, 12 double breastings, and 14 explantations. Choice of re-intervention was based on patient fitness and mode of failure. Mean EL detection duration following primary EVAR was 53.3 ± 6.82 months, while mean time to re-intervention was 70.20 ± 6.98 months. The mean sac size before the primary EVAR and re-intervention was 6.00 ± 1.75 cm and 7.51 ± 1.94 cm, respectively. Polyester (61.40%) was the most commonly employed stent-graft material. Use of more than three modular stent-graft components (3.42 ± 1.31, p = 0.846); with the proximal stent-graft diameter of 31.6 ± 3.80 cm (p = 0.651) and the use of iliac limbs more than 17 mm (p = 0.364), all added together are contributing factors. We had one peri-operative mortality following explantation due to sepsis-induced multiorgan failure.

Conclusions

Our re-intervention strategies matured from stent graft explantation to graft preservation with endovascular relining of the stent-graft. Graft preservation with aortic sacotomy and double breasting were used to manage concealed ELs due to aortic hygroma.

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.

Very Late Aortic Endograft Infection With Listeria monocytogenes in an Elderly Man

Endograft infection with Listeria monocytogenes is a rare, potentially devastating complication of endovascular aortic aneurysm repair. To our knowledge, only 8 cases have been reported. We describe the case of a 72-year-old man who presented with L. monocytogenes endograft infection and a 19-cm degenerative aneurysm 9 years after having undergone endovascular repair of an abdominal aortic aneurysm. The infection was successfully treated with open surgical excision of the infected aortoiliac endograft and its replacement with a rifampin-soaked, bifurcated Dacron graft.

Strategy to avoid open surgical conversion after endovascular aortic aneurysm repair for patients with infrarenal abdominal aortic aneurysm

Purpose

Open surgical conversion (OSC) is the last treatment option for patients with endovascular aneurysm repair (EVAR)failure. We investigated the underlying causes of EVAR failure requiring OSC and attempted to determine strategies to avoid OSC after EVAR.

Methods

We retrospectively reviewed the database of patients who underwent OSC after EVAR from 2005 to 2018 in a single institution. Twenty-six OSCs were performed in 24 patients (median age, 74.5 years; 79.2% of males) who had undergone standard EVAR. We investigated pre-, intra-, and postoperative computed tomography or angiographic images and outcomes of the OSCs.

Results

Two main indications for OSC were persistent endoleak (50.0%) and endograft infection (EI) (38.5%). All 13 patients who underwent OSC due to endoleaks received EVAR outside of indications for use. Among 10 patients who underwent OSC due to EI, we found overlooked infection sources in 7 (70.0%) at the time of EVAR or during the surveillance period. OSC was performed at a median of 31.8 months (interquartile range, 9.4-69.8) after EVAR as an emergency (15.4%) or elective (84.6%) surgery. Aortic endograft was removed in 84.6% of cases (totally, 57.7%; partially, 26.9%), whereas it was preserved in 4 cases (15.4%). After 26 OSCs, 2 early deaths (7.7%) and 2 aortoenteric fistulae (7.7%) developed as major complications.

Conclusion

OSC after EVAR was associated with relatively higher perioperative morbidity and mortality. To avoid OSC after EVAR, we recommend careful assessment of coexisting infection sources and avoidance of EVAR for patients with especially unfavorable anatomy for EVAR, particularly the in proximal neck.

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.

Laparoscopic ligation of Type II endoleaks following endovascular aneurysm repair: A systematic review

INTRODUCTION

The clinical significance of Type II endoleak remains contentious; the strategies used for its management have continued to expand. We systematically review the literature and comprehensively appraise the effectiveness of laparoscopic intervention in the management of this common complication.

METHODS

A systematic search was performed in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines on MEDLINE, EMBASE and Cochrane Library for relevant articles reporting laparoscopic surgery of Type II endoleak post-endovascular aortic repair.

RESULTS

Thirteen studies representing 40 patients were investigated. Mean age was 72.7 years, and proportion of males was 90.0%. All patients were American Society of Anesthesiologists grade II and above and underwent standard infrarenal endovascular aneurysm repair. The mean duration of operation was 130.2 min, with a mean blood loss across of 173.8 mL. The overall technical success rate was 90% (27/30). Two patients required reoperation within 24 h, with further lumbar ligations that were successful. One other patient required conversion to open surgery due to significant bleeding at the dorsal aorta. The perioperative and 30-day mortality rate was 2.5% (1/40). The mean length of hospital stay was 3.7 days (range 1 to 10 days). The mean length of follow-up was 36.7 months (range 3 to 103.2 months), where the rate of recurrence was 22.5% (9/40).

CONCLUSIONS

Laparoscopic ligation of feeding vessels causing Type II endoleak is potentially an alternative treatment after failed standard endovascular embolization, particularly in select centres with necessary resources and capabilities.

Endovascular and open surgical treatment of complications after endovascular aortic aneurysm repair: A single-center experience

While endovascular aortic aneurysm repair (EVAR) has proven to be a safer alternative to open surgical repair for infrarenal abdominal aortic aneurysms (AAA) repair, the development of stent-graft complications mandates follow-up computed tomography imaging to minimize AAA-related mortality. In this single-institution report, adverse EVAR events identified in 150 consecutive patients are detailed. Early morbidity was low (<3%), with only 1 patient death on post-procedure day 2. After discharge (mean follow-up of 24 months), 2 patients died from cancer and one AAA-related mortality occurred after open conversion for stent-graft migration. Although computed tomography imaging detected no EVAR endoleak at 30 days, 19 patients developed an endoleak, including three Type I and four Type III leaks. Our institutional series review confirmed that EVAR of infrarenal AAA is a safe and valid alternative to open surgical repair, but sac embolization at the primary procedure in patients judged to be at high risk for Type II endoleak should be considered.

Spontaneous Sealing of a Type Ia Endoleak after Ovation Stent Graft Implantation in a Patient with On-Label Aortic Neck Anatomy

We report a case of an early type Ia endoleak after endovascular aneurysm repair (EVAR) of an abdominal aortic aneurysm by Ovation Stent Graft implantation and spontaneously resolved without further reintervention. The patient presents a conical aortic neck, but EVAR was performed within the instruction for use proposed by manufactory. At completion angiography, a low-flow type Ia endoleak was present and left untreated. Computed tomographic angiography performed on the third postoperative day showed infolding of the 2 sealing rings. The patient was dismissed without further treatment. At 3-month follow-up, the leak appeared spontaneously sealed with partial expansion of the 2 rings.

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.

Aortouni-iliac endografting as an alternative salvage procedure to open conversion in failed endovascular aneurysm repair

PURPOSE

To present a single-center experience with failed EVAR requiring conversions comparing open surgery to a minimally invasive procedure modifying the existing stent-graft into an aortouni-iliac (AUI) configuration.

METHODS

A prospectively maintained database at our tertiary care university hospital was interrogated to identify all patients with failed EVAR who had undergone either stent-graft modification into an AUI configuration or open conversion between March 1995 and January 2012. Patients with late aneurysm ruptures were excluded. The search found 30 patients (one had initial treatment elsewhere) who required conversion among the 688 patients who had undergone EVAR in that time period. Before conversion, 16 (53%) patients had prior endovascular corrections to maintain aneurysm exclusion.

RESULTS

An average time of 52.2 months (median 46.9, IQR 0.0-92.5) elapsed between initial EVAR and conversion. There were 11 early conversions (including 7 on-table), while 19 procedures were done >30 days post EVAR. Twenty-two (73%) patients underwent AUI endografting, while open conversions were carried out in 8 (27%). Mean hospital stay after conversion was 19.5 days (median 13.0, IQR 8.0-17.0). Overall mortality after conversion was 3.3% (1 patient after on-table open conversion), but since the introduction of AUI endografting as an alternative treatment approach, 30-day mortality following conversions fell to zero.

CONCLUSION

Modification of a failed stent-graft into an AUI configuration serves as a less invasive treatment option compared to open conversion and allows salvage of the failed device. With the implementation of this alternative approach, mortality after conversion parallels the mortality of elective abdominal aneurysm repair.

Open Conversion after Endovascular Aortic Aneurysm Repair with the Ovation Prime™ Endograft

Advances in abdominal aortic aneurysm (AAA) endograft device technology have contributed to improved outcomes and durability of endovascular aortic aneurysm repair (EVAR), even in complex infrarenal aortic anatomies. However, stent graft failure secondary to endoleaks, migration, endotension and sac enlargement are persistent problems that can result in aneurysm rupture following EVAR.

A symptomatic infrarenal AAA (4mm proximal neck) was treated initially with an Ovation Prime™ device (TriVascular, Inc., Santa Rosa, CA) in an off-label fashion, leading to type Ia endoleak moderately reduced by additional proximal neck ballooning. A failed Chimney technique to the single patent, but severely stenosed, right renal artery preceded the use of this device. A large type Ia endoleak was evident at 6-month follow-up, but following a failed supplementary endovascular intervention with coils to seal the endoleak, the patient presented with hemorrhagic shock from AAA rupture, requiring urgent open conversion. Intraoperatively it was impossible to explant this new type of endograft. Circumferential tying of the infrarenal aorta with a Teflon band was unable to stop the bleeding. However, after dividing the body of the stent-graft below the two proximal polymer rings, the endoleak was successfully treated by suturing the graft with the proximal aortic neck. The procedure was completed with extension of the stump to the common femoral arteries using a bifurcated Dacron prosthesis.

The body of an Ovation Prime™ endograft may be impossible to explant in open conversion conditions. Large prospective studies with longer follow-up are required to adequately reflect the behavior of this particular device.

Treatment of complications following endovascular repair of abdominal aortic aneurysms

Endovascular aneurysm repair (EVAR) is an important treatment option for abdominal aortic aneurysms, with lower perioperative morbidity and mortality rates than open surgical aneurysm repair. However, EVAR is associated with several unique complications that are not encountered with surgical repair such as endoleaks, graft migration, and renal artery occlusion. Preservation of the morbidity and mortality advantages of EVAR relies on the successful treatment of these complications by minimally invasive, endovascular approaches. Some of the techniques used to treat EVAR complications include balloon dilation and stenting, deployment of additional stent-graft pieces, coil embolization, and thrombolysis. Although the employment of these endovascular salvage techniques is common, data regarding their intermediate- to long-term efficacy is sparse, and further studies are needed to determine their efficacy in preventing conversion to open aneurysm repair and aneurysm rupture.

Endoscopic type 2 endoleak repair following endovascular aortic aneurysm repair: acute results and follow-up experience

The purpose of this study was to evaluate immediate and long-term results of endoscopic type 2 endoleak repair (EER) following endovascular abdominal aortic aneurysm repair. The basic methods include a retrospective review of electronic and paper medical records of patients admitted or referred to our institution for EER. Between July 1999 and October 2007, eight consecutive patients underwent EER. Mean operative time was 190 (104–355) min. One patient died preoperatively, due to profuse venous bleeding . One procedure was redone due to a missed pair of lumbar arteries. Mean hospital stay was five days (2–10). During mean follow-up, 50 months (29–91), one patient required additional coil embolization for a persistent type 2 endoleak. Four patients were diagnosed with a type 1 and one with a type 3 endoleak; three of these patients required an additional procedure. In conclusion, in this small series EER proved not to be beneficial.

Conversion to open repair after endografting for abdominal aortic aneurysm: a review of causes, incidence, results, and surgical techniques of reconstruction

PURPOSE

To review the incidence, causes, and mortality rates of early and late conversion to open surgery after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA).

METHODS

A systematic search of the English-language literature from 2002 to 2009 was performed by interrogation of the PubMed, MEDLINE, and EMBASE databases. Studies were included if they: (1) had >100 patients treated with EVAR and (2) provided adequate data to calculate incidence and associated mortality rates. The search yielded 13 articles with sufficient data to analyze early conversion (12,236 patients, 178 conversions) and 15 articles with available data for late conversion (14,298 patients, 279 conversions).

RESULTS

The rate of early conversion among the 13 articles reviewed ranged from 0.8% to 5.9%; more recent studies carried lower rates of early conversion. Mortality rates of early conversion varied between 0% and 28.5%. Overall, there were 178 (1.5%) early conversions among the 12,236 AAAs treated with EVAR, with an average mortality of 12.4%. The rates of late conversion ranged from 0.4% to 22%. Of the 14,289 AAA patients undergoing endovascular repair, 279 (1.9%) required late conversion; the mortality rate was 10%.

CONCLUSION

Though the incidence is gradually declining, secondary interventions persist as the Achilles' heel of EVAR. A lifelong follow-up strategy for AAA patients treated with EVAR is essential for early detection and treatment of complications of the procedure. Vascular surgeons should be familiar with the complex open conversion procedures.

Conversion to open surgery after endovascular abdominal aortic aneurysms repair

The authors describe experience with conversions to open surgery after endovascular abdominal aneurysm repair and evaluate the frequency, causes and results of a total of 7 cases in their series of 165 patients treated over a 10-year period.

Secondary interventions following endovascular abdominal aortic aneurysm repair using current endografts. A EUROSTAR report

OBJECTIVE

The purpose of this study was to evaluate the need for secondary interventions after endovascular abdominal aortic aneurysm repair with current stent-grafts.

METHODS

Studied were data from 2846 patients treated from December 1999 until December 2004. The data were recorded from the EUROSTAR registry. The only patients studied were those with a follow-up of at least 12 months or until they had a secondary intervention within the first 12 months. The cumulative incidences of secondary transabdominal, extra-anatomic, and transfemoral interventions during follow-up (after the first postoperative month) were investigated.

RESULTS

A secondary intervention was performed in 247 patients (8.7%) at a mean of 12 months after the initial procedure within a follow-up period of a mean of 23 +/- 12 months. Of these, 57 (23%) transabdominal, 43 (16%) involved an extra-anatomic bypass, and 147 (60%) were by transfemoral approach. The cumulative incidence of secondary interventions was 6.0%, 8.7%, 12%, and 14% at 1, 2, 3, and 4 years, respectively. This corresponded with an annual rate of secondary interventions of 4.6%, which was remarkably lower than in a previously published EUROSTAR study of patients treated before 1999. Type I endoleaks (33% of procedures), migration (16%), and rupture (8.8%) were the most frequent reasons for secondary transabdominal interventions. Graft limb thrombosis was the indication for extra-anatomic bypass (60%). Type I endoleak (17%), type II endoleak (23%), device limb stenosis (14%), thrombosis (23%), and device migration (14%) were the most frequent reasons for secondary transfemoral interventions. Operative mortality was higher after secondary transabdominal interventions (12.3%, P = .007) compared with transfemoral interventions (2.7%). Overall survival was lower in patients with secondary transabdominal (P = .016) and extra-anatomic interventions (P < .0001) compared with patients without a secondary intervention.

CONCLUSION

Although the incidence of secondary interventions after endovascular aneurysm repair has substantially decreased in recent years, continuing need for surveillance for device-related complications remains necessary.

Conversion to Open Repair After Endografting for Abdominal Aortic Aneurysm: Causes, Incidence and Results

OBJECTIVE

To evaluate frequency, causes and results of conversion to Open repair (OR) after endovascular repair (EVAR) in a single centre during an 8-year period.

DESIGN

Six hundred and forty-nine consecutive patients undergoing EVAR were followed up prospectively for endograft-related complications.

OUTCOMES

Early conversion was any OR during or within 30 days from the primary EVAR. Late conversion was any OR with removal of the endograft after 30 days since a completed EVAR procedure.

RESULTS

Median patient follow-up was 38 months (1-93 months). Conversion to OR was performed in 38 patients; nine early and 29 late. Most (7/9) early conversions were due to extensive vessel calcification. Peri-operative mortality was 22% (2/9). Late conversions occurred at a median of 33 months after primary EVAR: 29 were elective and 4 urgent. During the same interval, 79 secondary endovascular interventions were performed, 7 of which failed. The risk of conversion to OR was 9% at 6 years. At multivariate logistic regression analysis, no single factor (short, large or angulated neck, suprarenal fixation, large pre-operative diameter, iliac aneurysms, ASA score risk) was associated with the risk of late failure requiring conversion to OR.

CONCLUSION

The risk of death after early conversion should be recognized, to avoid forcing morphological indications for primary EVAR. Occurrence of late conversion after EVAR is not negligible, affecting almost 1 out of 10 patients after 6 years. In the presence of an expanding aneurysm after EVAR, especially after a failed secondary endovascular correction, an aggressive attitude in fit patients allows outcomes at similar to those of primary OR.

Surgical Conversion of Abdominal Aortic Stent-grafts—Outcome and Technical Considerations

OBJECTIVE

The purpose of this study was to evaluate the outcome of patients with stented abdominal aortic aneurysms who had to undergo open aneurysm repair with partial or total stent-graft removal.

METHODS

Between October 1996 and December 2003, 117 patients with abdominal aortic aneurysms underwent endovascular repair. When open surgery was necessary during the initial and same anaesthesia as stent-graft implantation, it was defined as immediate conversion. When conversion was performed during a second anaesthesia, we defined it as late (acute or elective) conversion.

RESULTS

A total of 33 patients underwent conversion to open surgery. In 7 (6%) patients, immediate conversion was necessary due to stent-graft misplacement and obstruction of the renal arteries (n=4), type Ia endoleaks (n=2) and stent-graft dislocation into the aneurysm sac (n=1). During a mean follow-up period of 39.6 months (min 0.03 months, max 80.4 months), 26 (23.6%) of the remaining 110 patients underwent late conversion to open surgery for endoleak (n=12), rupture (n=6), thrombosis (n=4), graft fatigue (n=2), aorto-duodenal fistula (n=1), and recurring peripheral embolisms (n=1). The mortality of acute conversion was 38% (5 of 13). Elective conversion did not lead to any mortality.

CONCLUSION

Acute conversion of stented abdominal aortic aneurysms is associated with a high mortality. Elective stent-graft explantation with open aortic reconstruction is a safe but complex procedure.

Secondary conversion of the Gore Excluder to operative abdominal aortic aneurysm repair

OBJECTIVE

Reports continue to document the occurrence of major adverse events after endovascular aortic aneurysm repair. Although many of these problems can be successfully managed through endovascular salvage, operative conversion with explantation of the endoprosthesis remains necessary in some patients. We report herein a review of all patients initially enrolled in multicenter US clinical trials of the Excluder endograft who underwent secondary conversion to open surgical repair.

METHODS

Clinical data and relevant medical records of patients enrolled in phase I and II multicenter US clinical trials of the Excluder endograft were retrospectively reviewed for adverse events and further narrowed to those patients who underwent secondary operative conversion. Hospital records, operative and anesthesia reports, and all imaging studies were analyzed at initial implantation and at the time of subsequent open surgical repair.

RESULTS

Late open conversion was performed in 16 (2.7%) of the 594 patients enrolled in the Excluder clinical trials. Presumed endotension accounted for 8 of 16 of secondary conversions. In two of these patients, however, an endoleak was identified at the time of open surgical repair. Of the remaining eight patients, two underwent conversion for device infection, five for persistent endoleak, and one for aneurysm rupture. The overall 30-day mortality was 6.25% (1/16), with one death occurring in a patient with a ruptured aneurysm. Of patients who underwent conversion because of endotension, the maximal abdominal aortic aneurysm diameter (mean +/- SD) at the time of initial implantation and subsequent graft removal was 61 +/- 11 mm and 70 +/- 10 mm, respectively. The mean time to open conversion for treatment of endotension was 37 +/- 12 months (range, 20-50 months; median, 42 months). Freedom from conversion was 98.6% and 96.7% at 24 and 48 months, respectively.

CONCLUSIONS

Endotension in the absence of a demonstrable endoleak has been a major indication for late surgical conversion in patients treated with the Excluder endograft. Given the potential presence of an undetected endoleak and the possible effects of progressive sac enlargement on long-term device stability, continued close surveillance of patients with assumed endotension is required. Should changes in device design eliminate endotension, a further reduction in the already low incidence of late open conversion of the Excluder endograft can be anticipated.

Endovascular Aneurysm Repair versus Open Aneurysm Repair: Comparison of Treatment Outcome and Procedure-Related Reintervention Rate

We conducted a retrospective study to compare treatment outcome and procedure-related reintervention rates of endovascular aneurysm repair (EVAR) with those of open repair. Clinical and radiological data of patients treated at the Rijnstate Hospital (Arnhem, The Netherlands) for nonsymptomatic aortic abdominal aneurysm during October 1998-January 2004 were reviewed and analyzed for demographic data, aneurysm specifics, comorbid condition status, and perioperative outcome. There were 99 patients treated with EVAR and 116 patients treated with open repair. Significant differences in age were seen between treatment groups, patients under the age of 80 being more likely to have open repair (p < 0.004). The EVAR group consisted of significantly fewer women (p < 0.029). Of seven comorbid conditions, four reached significant differences between treatment groups; patients with ischemic heart disease (p < 0.044), heart failure (p < 0.006), renal failure (p < 0.033), or peripheral arterial disease (p < 0.006) were more likely to have EVAR. Comparison of aneurysm anatomy showed no difference in size between EVAR (mean 57.7 mm, 95% CI 55.9-59.5 mm) and open repair (mean 60.1 mm, 95% CI 57.9-62.3 mm). Significant differences were seen in aneurysm neck length and diameter. Operative outcome showed differences in length of hospital stay (median, EVAR 7 vs. open repair 11 days), 30-day mortality (p < 0.048), postoperative hematoma (p < 0.001), and postoperative pulmonary infections (p < 0.001), all in favor of EVAR. Follow-up of the EVAR group showed a decrease (mean 10 mm, 95% CI 7-14 mm) of aneurysm diameter in 15% of cases during follow-up (mean 18 months, range 1-66). Despite higher age and more comorbidity of patients undergoing EVAR, 30-day mortality, postoperative pulmonary infection rate, and length of hospital stay were lower than for those undergoing open repair. Both EVAR and open repair can be performed on a subset of patients with low mortality, complication, and reintervention rates.

What is the significance of endoleaks and endotension

Endovascular repair has been used over a decade as a treatment of abdominal aortic aneurysm, and has become a widely accepted treatment method with a low rate of perioperative complications. Endoleak, perigraft blood flow outside endograft but within aneurysmsac, has been intensively studied during the last 10 years of endovascular aneurysm repair (EVR). The natural history of aneurysms with endoleak and the true clinical significance of various types of endoleaks remains unclear. Type I/III endoleak has been found to be associated with aneurysm rupture, while the risk of rupture of aneurysms with type II endoleak and endotension appears very small. In endotension, the aneurysm sac remains pressurized, even if there is no evidence of an endoleak. Currently,it is accepted that type I/III endoleaks should be corrected, preferably by endovascular means, due to the risk of rupture. If endovascular repair is not possible, then open conversion should be considered. The risk of conversion should be weighed against the risk of aneurysm rupture. Treatment of type II endoleaks and endotension is more controversial. In those with aneurysm enlargement,secondary interventions are often performed.

Total laparoscopic infrarenal aortic aneurysm repair: Preliminary results

OBJECTIVES

We describe our initial experience of total laparoscopic abdominal aortic aneurysm (AAA) repair.

MATERIAL AND METHODS

Between February 2002 and September 2003, we performed 30 total laparoscopic AAA repairs in 27 men and 3 women. Median age was 71.5 years (range, 46-85 years). Median aneurysm size was 51.5 mm (range, 30-79 mm). American Society of Anesthesiologists class of patients was II, III and IV in 10, 19, and 1 cases, respectively. We performed total laparoscopic endoaneurysmorrhaphy and aneurysm exclusion in 27 and 3 patients, respectively. We used the laparoscopic transperitoneal left retrocolic approach in 27 patients. We operated on 2 patients via a tranperitoneal left retrorenal approach and 1 patient via a retroperitoneoscopic approach.

RESULTS

We implanted tube grafts and bifurcated grafts in 11 and 19 patients, respectively. Two minilaparotomies were performed. In 1 case, exposure via a retroperitoneal approach was difficult and, in another case, distal aorta was extremely calcified. Median operative time was 290 minutes (range, 160-420 minutes). Median aortic clamping time was 78 minutes (range, 35-230 minutes). Median blood loss was 1680 cc (range, 300-6900 cc). In our early experience, 2 patients died of myocardial infarction. Ten major nonlethal postoperative complications were observed in 8 patients: 4 transcient renal insufficiencies, 2 cases of lung atelectasis, 1 bowel obstruction, 1 spleen rupture, 1 external iliac artery dissection, and 1 iliac hematoma. Others patients had an excellent recovery with rapid return to general diet and ambulation. Median hospital stay was 9 days (range, 8-37 days). With a median follow-up of 12 months (range, 0.5-20 months), patients had a complete recovery and all grafts were patent.

CONCLUSION

These preliminary results show that total laparoscopic AAA repair is feasible and worthwhile for patients once the learning curve is overcome. However, prior training and experience in laparoscopic aortic surgery are needed to perform total laparoscopic AAA repair. Despite these encouraging results, a greater experience and further evaluation are required to ensure the real benefit of this technique compared with open AAA repair.

Intraoperative monitoring during vascular surgery

The principal objectives of intraoperative monitoring are to improve perioperative outcome, facilitate surgery and reduce adverse events, using continuously collected data of cardiopulmonary,neurologic and metabolic function to guide pharmacologic and physiologic therapy. Although sophisticated and reliable apparatus may be used to collect these data they are useless, or even harmful, without proper interpretation. This article provides a comprehensive overview of recent publications on the history,philosophy, and semantics of monitoring.