Late open conversion after endovascular abdominal aortic aneurysm repair

Short-term and Midterm Results of Fenestrated Anaconda Endograft in Patients with Previous Endovascular Aneurysm Repair

PURPOSE

To review short-term and midterm results of the fenestrated Anaconda stent graft in management of patients with pre-existing endovascular aortic stent graft and persistent type 1a endoleak.

MATERIALS AND METHODS

This single-center retrospective study assessed all consecutive patients with type 1a endoleak and pre-existing endovascular aneurysm repair (EVAR) treated with fenestrated Anaconda stent grafts. Ten patients (9 males; mean age 78 y) with mean follow-up of 22.4 months ± 13 were included. Average aneurysm size was 80.1 mm (range, 62-101 mm). Mean time for conversion to fenestrated EVAR following original EVAR was 53.7 months (range, 22-101 months; median 54 months). Technical and clinical success; anatomic features, including aortic tortuosity, side vessel angulation, and stenosis; complications; and reinterventions were recorded.

RESULTS

The technical success rate was 90%. There was no open conversion and no 30-day mortality, leading to a clinical success rate of 100%. Five of 10 patients demonstrated an aortic tortuosity index of grade 2 or 3. Additional hostile anatomy that made side vessel catheterization challenging was observed in 15 vessels (45%) with a stenosis of ≥ 50% (related to atherosclerotic disease or struts of indwelling prosthesis) and 21 vessels (66%) with ≤ 70° angulation. Two reinterventions, renal artery stent angioplasty and renal artery covered stent extension, were observed at 2 and 13 months.

CONCLUSIONS

Use of the fenestrated Anaconda endograft in patients with type 1a endoleaks following previous EVAR is safe, feasible, and offers some technical features that facilitate overcoming certain anatomic difficulties.

Late open conversions after endovascular abdominal aneurysm repair in an urgent setting

OBJECTIVES

We report a multicenter experience of urgent late open conversion (LOC), with the goal of identifying the mode of presentation, technical aspects, and outcomes of this cohort of patients.

METHODS

A retrospective analysis of endovascular aneurysm repair (EVAR) requiring LOC (>30 days after implantation) from 1996 to 2016 in six vascular centers was performed. Patients with aneurysm rupture or other conditions requiring urgent surgery (<24 hours) were included. Patient demographics, time interval between EVAR and LOC, endograft characteristics, previous attempts at endovascular correction, indications, operative technique, 30-day mortality and morbidity, and long-term survival were analyzed.

RESULTS

There were 42 patients (88.1% men; mean age, 75.8 ± 9.0 years) included. Among the 42 explanted grafts, 33 were bifurcated, 1 tube, 6 aortouni-iliac, and 2 side-branch devices. Suprarenal fixation was present in 78.6%. Twelve patients (28.6%) underwent endovascular reintervention before LOC. Indications for urgent LOC were aneurysm rupture in 24 of the 42 cases (57.1%), endograft infection in 11 (26.2%), endoleak associated with aneurysm growth and pain in 6 (14.3%), and recurrent endograft thrombosis in 2 (4.8%). The proximal aortic cross-clamping site was infrarenal in 38.1% of cases, suprarenal in 19.1%, and supraceliac in 42.9%. Complete removal of the endograft was performed in 32 patients (76.2%) and partial removal in 10 (proximal preservation in 7 of 10). Reconstructions were performed with Dacron grafts in 33 of the 42 cases, cryopreserved arterial allografts in 5, and endograft removal associated with prosthetic axillobifemoral bypass in 4. The 30-day mortality was 23.8%; hemorrhagic shock was an independent risk factor of early mortality (odds ratio, 10.5; 95% confidence interval, 1.5-73.7; P = .018). During a mean follow-up of 23.9 ± 36.0 months, two late aneurysm-related deaths occurred. The estimated 1- and 5-year survival rates were 62.1% and 46.1%, respectively.

CONCLUSIONS

Urgent LOC after EVAR are associated with high postoperative mortality rates and poor long-term survival. Further studies are necessary to define the timing and the best treatment option for failing EVAR.

Early results with the custom-made Fenestrated Anaconda aortic cuff in the treatment of complex abdominal aortic aneurysm

OBJECTIVE

The objective of this study was to investigate the feasibility of a specific custom-made fenestrated aortic cuff in the treatment of complex abdominal aortic aneurysms (AAAs).

METHODS

Between 2013 and 2016, a total of 57 custom-made Fenestrated Anaconda (Vascutek, Inchinnan, Scotland, UK) aortic cuffs were placed in 38 centers worldwide. All centers were invited to participate in this retrospective analysis. Postoperative and follow-up data included the presence of adverse events, necessity for reintervention, and renal function.

RESULTS

Fifteen clinics participated, leading to 29 cases. Median age at operation was 74 years (interquartile range [IQR], 71-78 years); five patients were female. Two patients were treated for a para-anastomotic AAA after open AAA repair, 19 patients were treated because of a complicated course after primary endovascular AAA repair, and 8 cases were primary procedures for AAA. A total of 76 fenestrations (mean, 2.6 per case) were used. Four patients needed seven adjunctive procedures. Two patients underwent conversion, one because of a dissection of the superior mesenteric artery and one because of perforation of a renal artery. Median operation time was 225 minutes (IQR, 150-260 minutes); median blood loss, 200 mL (IQR, 100-500 mL); and median contrast volume, 150 mL (IQR, 92-260 mL). Primary technical success was achieved in 86% and secondary technical success in 93%. The 30-day morbidity was 7 of 29 with a mortality rate of 4 of 29. Estimated glomerular filtration rate remained unchanged before and after surgery (76 to 77 mL/min/m²). Between preoperative and median follow-up of 11 months, estimated glomerular filtration rate was reduced statistically significantly (76 to 63 mL/min/m²). During follow-up, 9 cases had an increase in aneurysm sac diameter (5 cases >5 mm); 14 cases had a stable or decreased aneurysm sac diameter; and in 2 cases, no aneurysm size was reported. No type I endoleak was reported, and two cases with a type III endoleak were treated by endovascular means during follow-up. Survival, reintervention-free survival, and target vessel patency at 1 year were 81% ± 8%, 75% ± 9%, and 99% ± 1%, respectively. After 2 years, these numbers were 81% ± 8%, 67% ± 11%, and 88% ± 6%, respectively. During follow-up, the two patients with a type III endoleak needed endograft-related reinterventions.

CONCLUSIONS

Treatment with this specific custom-made fenestrated aortic cuff is feasible after complicated previous (endovascular) aortic repair or in complex AAAs. The complexity of certain AAA cases is underlined in this study, and the Fenestrated Anaconda aortic cuff is a valid option in selected cases in which few treatment options are left.

An Institution-Wide Algorithm for Treatment of Type II Endoleak Following Endovascular Aneurysm Repair (EVAR)

Objectives:

Multiple endovascular techniques have been described for the treatment of persistent type II endoleaks (pT2ELs) causing aneurysm sac growth following endovascular aneurysm repair (EVAR). In the event of a failed endovascular procedure and a pT2EL, a consensus regarding further treatment is lacking, and the literature suggests repeated endovascular attempts are rarely successful. Herein, we propose an algorithm for definitive management of pT2ELs with persistent sac growth following EVAR.

Methods:

A retrospective review of 29 patients who underwent treatment of persistent sac growth in the setting of pT2ELs was performed. Intervention methods were determined at the discretion of the operating surgeon. Aneurysmal sac enlargement was defined as a diameter increase > 5 mm, and persistent endoleak was defined as lasting greater than 6 months.

Results:

From 2000 to 2015, 917 EVAR procedures were performed at our institution. Isolated pT2ELs with sac enlargement were identified in 29 patients. Twenty-five patients underwent direct translumbar sac puncture and coiling and/or Onyx (Onyx, Plymouth, Minnesota) embolization of the culprit vessels. Thirteen (52%) of 25 patients had pT2EL after first endovascular intervention, and 10 (40%) of 25 patients failed 2 endovascular treatments. Of those 10, 7 displayed persistent aneurysmal sac growth and underwent a third embolization procedure. Type II endoleaks persisted in 6 patients; 3 patients were subsequently treated with laparotomy, ligation of lumbar vessels, sac exploration, and sac plication around the endograft. Technical success for this technique was 100%. During a mean follow-up of 38.4 months, no recurrent T2ELs, stent graft migration, and/or disjunction were observed.

Conclusions:

We propose a new algorithm for the management of pT2ELs. If 2 endovascular procedures fail to control of the endoleak, repeat endovascular attempts are not recommended. Endovascular failure should be followed by laparotomy with surgical ligation of culprit feeding vessels followed by sac exploration and plication of the sac, and endoaneurysmorrhaphy.

Endovascular treatment of para-anastomotic aneurysms after open abdominal aortic surgery

INTRODUCTION

The repair of long-term complications of open abdominal aortic repair such as para-anastomotic aneurysm (PAA) and pseudoaneurysm (PSA) is very challenging. The aim of this study was to assess the outcomes of endovascular repair of PAA/PSA after previous open aortic surgery for aneurismal or occlusive disease.

EVIDENCE ACQUISITION

A systematic review was undertaken; a search was performed (PRISMA) in MEDLINE, CENTRAL, Cochrane databases and key references of all studies of endovascular treatment of PAA/PSA after open aortic surgery.

EVIDENCE SYNTHESIS

Eighteen studies included totally 433 patients (86.3% males) with mean age of 71±2.5 years were identified. Most of the patients were asymptomatic (76%) and diagnosed with PAA (60.5%), while 81.6% had history of open aortic reconstruction for aneurismal disease. The mean diameter of para-anastomotic aneurysms was 59.7 mm (from 23 mm to 110 mm) and the mean duration until their diagnosis was 10±2 years. Standard bifurcated (23.7%), fenestrated (23.4%) and aorto-uni-iliac stent-grafts (16.3%) were mostly used. The technical success rate was 97.8% (391/400) with 1.4% (6/433) 30 day-mortality rate and mean hospital stay of 6±3 days. The mean 1- and 2- year survival rate was 87.8% and 78.8%, respectively. The follow-up ranged from 9 to 43 months, with presenting complications such as endoleak type I (24/378; 6.3%), type II (15/354; 4.3%), type III (3/378;0.8%), migration (4/378; 1%) and limb occlusion (5/310;1.6%). Additionally, 5.7% (19/332) of the patients underwent open conversion, while the total re-intervention rate was 11.4% (39/340; time of reintervention ranged from 7 to 30 months). In cases in which a stent was used for splanchnic vessels (renal artery: 188, superior mesenteric artery: 98, celiac artery: 64), the primary patency rate was 97.4% (341/350).

CONCLUSIONS

Endovascular treatment of PAAs and PSAs after previous open aortic surgery is a feasible and efficient option with high technical success rate, low 30-day mortality and good mid-term outcomes.

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.

Endograft Infection After Endovascular Abdominal Aortic Aneurysm Repair: A Systematic Review and Meta-analysis

Purpose: To report a meta-analysis of the published evidence on the outcomes of aortic endograft infection after endovascular aneurysm repair (EVAR). Methods: A search of electronic information sources (PubMed/MEDLINE, SCOPUS, CENTRAL) and bibliographic reference lists identified 12 studies reporting on 362 patients (mean age 72 years; 279 men). The methodological quality of the selected studies was assessed using the Newcastle-Ottawa scale. Endpoints were 30-day/in-hospital mortality and follow-up mortality. Pooled estimates are reported with the 95% confidence interval (CI). The review was registered at the International Prospective Register of Systematic Reviews in Health and Social Care (CRD42016034166). Results: The incidence of graft infection after EVAR was 0.6% (95% CI 0.4% to 0.8%). The time from implantation to diagnosis ranged from 1 to 128 months (mean 25). The majority of patients (293, 81%) underwent surgical treatment (95% CI 77% to 83%); 9 (2.5%) patients (95% CI 21% to 43%) received conservative treatment. Aortic replacement with a prosthetic graft was performed in 58% (95% CI 52% to 62%), whereas cryopreserved allografts and autologous grafts were used in 31% (95% CI 28% to 33%) and 11% (95% CI% 8 to 14%), respectively. Less than half of the patients (40%) had emergency surgery. The pooled estimate of 30-day/in-hospital mortality was 26.6% (95% CI 16.9% to 39.2%). The pooled 30-day/in-hospital mortality for 9 patients treated conservatively was 63.3% (95% CI 30.7% to 87.0%). The pooled overall follow-up mortality was 45.7% (95% CI 36.4% to 55.4%) vs 58.6% (95% CI 28.8% to 83.3%) for the 9 patients receiving conservative treatment. Conclusion: Aortic endograft infection is a rare complication after EVAR. Surgical treatment with complete explantation of the infected endograft seems to be the optimal management in selected patients. Supportive medical treatment without surgical intervention has a significant associated mortality.

Conversion from endovascular to open abdominal aortic aneurysm repair

BACKGROUND

Previous studies have found conflicting results regarding the operative risks associated with conversion to open abdominal aortic aneurysm (AAA) repair after failed endovascular treatment (endovascular aneurysm repair [EVAR]). The purpose of this study was to assess the outcome of patients undergoing a conversion, and compare outcomes with standard open AAA repair and EVAR. In addition, we sought out to identify factors associated with conversion.

METHODS

All patients undergoing a conversion to open repair, and those undergoing standard EVAR and open repair between 2005 and 2013 were included from the National Surgical Quality Improvement Program. Multivariable logistic regression analysis was used to identify factors associated with conversion, and to assess independent perioperative risks associated with conversion compared with standard AAA repair. Subanalysis for factors associated with conversion was performed among patients additionally included in the more detailed targeted vascular module of the National Surgical Quality Improvement Program.

RESULTS

A total of 32,164 patients were included, with 300 conversions, 7188 standard open repairs, and 24,676 EVARs. Conversion to open repair was associated with a significantly higher 30-day mortality than standard open repair (10.0% vs 4.2%; odds ratio [OR], 2.4; 95% confidence interval [CI], 1.6-3.6; P < .001), and EVAR (10.0% vs 1.7%; OR, 7.2; 95% CI, 4.8-10.9; P < .001). Conversion surgery was additionally followed by an increased occurrence of any complication (OR, 1.5; 95% CI, 1.2-1.9 [open]; OR, 7.8; 95% CI, 6.1-9.9 [EVAR]). Factors associated with conversion were young age (OR, 1.2 per 10 years decrease; 95% CI, 1.1-1.4), female gender (OR, 1.5; 95% CI, 1.2-2.0), and nonwhite race (OR, 1.8; 95% CI, 1.3-2.6). Conversely, body mass index >30 was negatively associated with (OR, 0.7; 95% CI, 0.5-0.9). Among anatomic characteristics captured in the targeted vascular data set (n = 4555), large aneurysm diameter demonstrated to be strongly associated with conversion (OR, 1.1 per 1 cm increase; 95% CI, 1.03-1.1).

CONCLUSIONS

Conversion to open repair after failed EVAR is associated with substantially increased perioperative morbidity and mortality compared with standard AAA repair. Factors associated with conversion are large diameter of the aneurysm, young age, female gender, and nonwhite race, whereas obesity is inversely related to conversion surgery.

EVAR and OPEN treatment of abdominal aortic aneurysm: What is the role of MMP-9 in the follow-up?

INTRODUCTION

The aim of our study is to verify the role of metalloproteinases in endovascular repair (EVAR) and OPEN surgery treatment for abdominal aortic aneurysm (AAA). Postoperatively, these enzymes could represent an important biomarker to adapt diagnostic tests and further investigations during follow-up.

MATERIAL AND METHOD

From 2004 to 2008, 55 patients were considered with AAA. Of these, 33 patients (mean age: 70.1 years), (mean AAA diameter: 5.4cm) were treated with OPEN surgery (group A) and 22 (mean age: 74.1 years) (mean AAA diameter: 5.1cm) were treated with EVAR. In 17 of them, there were no signs of endoleak (group B1), while in 5 patients, a presence of endoleak (group B2) was detected. Plasma samples were collected in order to determine MMP-9 activity. Enzyme immunoassay was performed preoperatively at 1, 3, 6 and 12 months. Patients treated conventionally were clinically examined after 1 and 12 months by ultrasound. Patients undergoing EVAR treatment were clinically examined by CT scan after 1, 3, 6 and 12 months. The analysis was done by assessing the interaction over time of the MMP-9 value in B1 and B2 groups.

RESULTS

The average values observed for MMP-9 were preoperatively and at 1, 3, 6 and 12 months, respectively: in group A 150.8ng/mL (SD=30.5), 252.5ng/mL (SD=25.2), 315.4ng/mL (SD=22.7), 295.3ng/mL (SD=26.8), 210.7ng/mL (SD=30.2); in group B1 105ng/mL (SD=10.8), 125.6ng/mL (SD=18), 85.8ng/mL (SD=19.9), 95ng/mL (SD=20.2), 80.4ng/mL (SD=15.6); in group B2 149ng/mL (29.2), 375.4ng/mL (SD=40.2), 215ng/mL (SD=35.9), 180ng/mL (SD=20.2), 175ng/mL (SD=33.4). The MMP-9 level was higher in group B2 compared to group B1 (P=0.01), suggesting a correlation with the presence of the endoleak.

CONCLUSIONS

This preliminary study shows that MMP-9 may be a biomarker of the presence of endoleak. Other further investigations and larger series are needed to show that metalloproteases could play a role in the follow-up of EVAR treated patients.

Endovascular Aneurysm Sealing (EVAS) and Chimney EVAS in the Treatment of Failed Endovascular Aneurysm Repairs

PURPOSE

To assess the technical success and clinical outcome of reinterventions using the Nellix Endovascular Aneurysm Sealing (EVAS) System to treat complications after endovascular aneurysm repair (EVAR).

METHODS

Fifteen consecutive patients (mean age 79 years; 14 men) with prior EVAR were treated with EVAS between March 2014 and December 2015 at 2 institutions. The failed prior EVARs included 13 bifurcated endografts, 1 bifurcated graft plus fenestrated cuff, and 1 tube endograft. Endoleaks were the predominant indications: type Ia in 10 and type III in 5 (3 type IIIa and 2 type IIIb). All patients presented with progressive aortic aneurysms (median 7.85-cm diameter; range 6.5-11). Eight patients were treated on an urgent or emergency basis (6 symptomatic aneurysms and 2 contained ruptures). All patients underwent Nellix relining of the failed stent-graft; 10 had chimney (Ch) procedures in combination with EVAS (chEVAS) because the proximal landing zones were inadequate.

RESULTS

Technical success was 100%. All endoleaks were successfully sealed, and no additional intervention was required. No further endoleak after EVAS or chEVAS was recorded. Endobag protrusion occurred in 1 case without sequelae. One elderly patient with ruptured aneurysm died from multiple organ failure 2 months postoperatively. One renal artery guidewire injury led to nephrectomy because of active bleeding. No reinterventions, aneurysm-related mortalities, graft thrombosis, endoleaks, or chimney graft occlusions were observed during a median follow-up of 8 months (range 3-24).

CONCLUSION

The present preliminary experience demonstrates that the use of EVAS/chEVAS is feasible for treatment of failed EVAR. This technique may be used as bailout or an alternative treatment when other established methods are infeasible or not available.

Outcomes after endovascular aneurysm repair conversion and primary aortic repair for urgent and emergency indications in the Society for Vascular Surgery Vascular Quality Initiative

OBJECTIVE

Open conversion after endovascular aortic aneurysm repair (EVAR-c) is performed nonelectively in up to 60% of cases. EVAR-c has been reported to have significantly greater risk of postoperative morbidity and mortality than primary aortic repair, but few data exist on outcomes for symptomatic or ruptured presentations. This study determined outcomes and identified predictors of postoperative major adverse cardiac events (MACEs) and mortality for patients undergoing nonelective EVAR-c compared with nonelective primary aortic repair (PAR) in the Vascular Quality Initiative (VQI).

METHODS

All VQI patients undergoing urgent/emergency EVAR-c or urgent/emergency PAR from 2002 to 2014 were reviewed. Urgent presentation was defined by repair ≤24 hours of a nonelective admission, and emergency operations had clinical or radiographic evidence, or both, of rupture. End points included in-hospital MACE (myocardial infarction, dysrhythmia, congestive heart failure) and 30-day mortality. Possible covariates identified on univariate analysis (P < .2) were entered into a multivariable model, and stepwise elimination identified the best subset of predictors. Generalized estimating equations logistic regression analysis was used to determine the relative effect of EVAR-c compared with PAR on outcomes.

RESULTS

During the study interval, we identified 277 EVAR-c, and 118 (43%) underwent urgent/emergency repair. nonelective PAR was performed in 1388 of 6152 total (23%). EVAR-c patients were older (75 ± 9 vs 71 ± 10 years; P < .0001), more likely to be male (84% vs 74%; P = .02), and had a higher prevalence of hypertension (88% vs 79%; P = .02) and coronary artery disease (38% vs 27%; P = .01). No differences in MACE (EVAR-c, 31% [n = 34] vs PAR, 30% [n = 398]) or any major postoperative complication (EVAR-c, 57% [n = 63] vs PAR, 55% [n = 740]; P = .8) were found; however, 30-day mortality was significantly greater in EVAR-c (37% [n = 41]) than in (PAR, 24% [n = 291]; P = .003), with an odds ratio (OR) of 2.2 (95% confidence interval [CI], 1.04-4.77; P = .04) for EVAR-c. Predictors of any MACE included age (OR, × 1.03 for each additional year; 95% CI, 1.01-1.03; P = .0002), male gender (OR, 1.3; 95% CI, 1.03-1.67; P = .03), body mass index ≤20 kg/m² (OR, 1.8; 95% CI, 1.13-2.87; P = .01), chronic obstructive pulmonary disease (OR, 1.2; 95% CI, 0.86-1.80; P = .25), congestive heart failure (OR, 1.5; 95% CI, 0.98-2.34; P = .06), preoperative chronic β-blocker use (OR, 1.3; 95% CI, 0.97-1.63; P = .09), and emergency presentation (OR, 2.3; 95% CI, 1.8-3.01; area under the curve, 0.70; P < .0001). Significant predictors for 30-day mortality were age (OR × 1.07 for each additional year; 95% CI, 1.05-1.09; P < .0001), female gender (OR, 1.6; 95% CI, 1.01-2.46; P = .04), preoperative creatinine >1.8 mg/dL (OR, 1.6; 95% CI, 1.04-2.35; P = .03), an emergency presentation (OR, 4.8; 95% CI, 2.93-7.93; P < .0001), and renal/visceral ischemia (OR, × 1.1 for each unit increase log (time-minutes); 95% CI, 1.02-1.22; area under the curve, 0.84; P = .01).

CONCLUSIONS

Nonelective EVAR-c patients are older and have higher prevalence of cardiovascular risk factors than PAR patients. Similar rates of postoperative complications occur; however, urgent/emergency EVAR-c has a significantly higher risk of 30-day mortality than nonelective PAR. Several variables are identified that predict outcomes after these repairs and may help risk stratify patients to further inform clinical decision making when patients present nonelectively with EVAR failure.

Type II endoleaks: challenges and solutions

Type II endoleaks are the most common endovascular complications of endovascular abdominal aortic aneurysm repair (EVAR); however, there has been a divided opinion regarding their significance in EVAR. Some advocate a conservative approach unless there is clear evidence of sac expansion, while others maintain early intervention is best to prevent adverse late outcomes such as rupture. There is a lack of level-one evidence in this challenging group of patients, and due to a low event rate of complications, large numbers of patients would be required in well-designed trials to fully understand the natural history of type II endoleak. This review will discuss the imaging, management, and outcome of patients with isolated type II endoleaks following infra-renal EVAR.

Type IIIb Endoleak and Relining

Purpose: To examine the changes in distraction force following relining of a conventional abdominal aortic stent-graft with a type IIIb endoleak using the Nellix endovascular sealing device compared to a unilateral stent-graft. Methods: Relining is often used to repair type IIIb endoleaks, but the consequences to graft stability are unknown. A mathematical model was constructed based on pressure and volume flow through the stent-grafts, incorporating recognized distraction force equations. Steady flow was presumed at peak systolic pressures to calculate the maximum distraction force, with gravity ignored. Distraction forces for 28- to 36-mm-diameter stent-graft bodies with 16-mm limbs were calculated and compared to forces following relining with single and double Nellix devices or the Renu unilateral device. Results: Distraction forces for the 28-, 32-, and 36-mm stent-grafts prior to relining were 5.99, 10.21, and 14.99 N, respectively. Similar forces were reported after relining with bilateral Nellix devices (5.86, 10.08, and 14.86 N, respectively). However, use of a unilateral Nellix increased the distraction forces to 9.92, 14.14, and 18.92 N, respectively. These were comparable to the increase observed after relining with a Renu unilateral stent-graft (9.87, 14.09, and 18.86 N, respectively). The proportional increase in distraction force for a unilateral relining ranged from 26% to 66%, with the greatest increase noted in the smaller diameter main bodies. Conclusion: Relining a stent-graft with a type IIIb endoleak using bilateral Nellix devices does not increase the distraction force. However, a unilateral Nellix device or the Renu system could theoretically increase the distraction force by up to 66%, potentially risking migration and type Ia endoleak. In clinical practice, these results suggest that a relining with bilateral Nellix may have benefits over the Renu unilateral stent-graft.

Defining risk and identifying predictors of mortality for open conversion after endovascular aortic aneurysm repair

OBJECTIVE

Risk of open conversion after endovascular aortic aneurysm repair (EVAR-c) is poorly defined. The purpose of this analysis was to determine outcomes of elective EVAR-c compared with elective primary open abdominal aortic aneurysm repair (PAR) in the Vascular Quality Initiative.

METHODS

Vascular Quality Initiative patients who underwent elective EVAR-c and PAR (2002-2014) were reviewed. Candidate predictors of major adverse cardiac event (MACE) and/or 30-day mortality were entered into a multivariable model, and stepwise elimination was used to reduce the number of covariates to a best subset of predictors. To estimate the additive risk of EVAR-c for MACE or 30-day mortality over PAR, this variable was added along with the best subset of predictors into generalized estimating equations logistic regression models.

RESULTS

We identified 159 EVAR-c and 3741 PAR patients. EVAR-c patients were older (73.5 ± 8.1 vs 69.5 ± 8.4 years; P < .0001), more likely to have diabetes (21% vs 15%; P = .03), and history of lower extremity bypass (9% vs 4%; P = .0006). EVAR-c was associated with a higher incidence of retroperitoneal aortic exposure (41%; n = 64 vs PAR, 26%, n = 976; P < .0001), use of a bifurcated graft (65%; n = 101 vs PAR, 52%; n = 1923; P = .001), greater blood loss (median [interquartile range], 2000 mL [1010-3500] vs PAR, 1200 mL [750-2000]; P < .0001) and longer procedure times (EVAR-c, 275 ± 122 minutes vs PAR, 232 ± 9 minutes; P < .0001). However, PAR more frequently was completed with a suprarenal and/or mesenteric cross-clamp (74%, n = 2749 vs EVAR-c, 53%, n = 83; P < .0001) and had a higher incidence of concomitant procedures (26%; n = 972 vs EVAR-c, 18%; n = 28; P = .03). Nonadjusted 30-day mortality was greater after EVAR-c: EVAR-c, 8% (n = 10) vs PAR, 3% (n = 105); P = .009. There was no difference in complication rates: EVAR-c, 33% (n = 52) vs PAR, 28% (n = 1056); P =.3. Preoperative 30-day mortality predictors included age (odds ratio [OR], 1.06/y, 95% confidence interval [CI], 1.04-1.1; P < .0001), chronic obstructive pulmonary disease (OR, 2.4; 95% CI, 1.6-3.5; P < .0001), history of leg bypass (OR, 2.3, 1.2-4.4;P =.01), suprarenal cross-clamp (OR 2.2, 1.2-4.1;P =.01), prior carotid revascularization (OR 2.2; 95% CI, 1.3-3.8; P = .0004), congestive heart failure (OR, 1.8; 95% CI, 0.9-3.5; P = .08), and female sex (OR, 1.6; 95% CI, 1.1-2.3; P = .02; area under the curve, 0.75). When controlling for covariates, EVAR-c was not significantly associated with MACE (OR, 1.2; 95% CI, 0.7-2.0; P = .4) or 30-day mortality (OR, 2.0; 0.9-4.2; P = .08).

CONCLUSIONS

EVAR-c patients are typically older, have more comorbidities, and experience greater blood loss and longer procedure times compared with PAR patients. However, postoperative morbidity and mortality are primarily driven by patient covariates and intraoperative factors, rather than the need for endograft explantation. Several preoperative variables were identified as predictors of 30-day mortality after elective EVAR-c and should be considered during the decision-making process for remedial treatment of failed endovascular PAR.

Laparo- and thoracoscopic aortic aneurysm neck optimization and treatment of potential endoleaks type IA and II in a porcine model

Background

Endovascular repair of aortic aneurysms has a higher incidence of late complications, and open conversion (OC) associated with high mortality may be required. As alternatives to OCs, we propose minimal invasive laparo-/thoracoscopic approaches, either to control endoleaks after endovascular repair, or to convert non-endovascular treatable cases due to a hostile neck anatomy by inserting a peri-aortic PTFE collar before endovascular repair. Such interventions may reduce complications and the necessity for OCs in the future.

Methods

In twelve pigs, were 10 had infra-/juxtrarenal AAAs, externally placed collars/aneuwraps around the proximal AAA neck and just below the left subclavian artery and division of the aortic side branches were carried out laparo-and thoracoscopically.

Results

For the laparoscopic and thoracoscopic procedures respectively, mean operative time was 143 ± 41 min and 86 ± 51 min and a mean of 2.6 and 2.25 aortic side branches were ligated/divided. For both procedures, the last half in the series were carried out significantly faster (p < 0.05) indicating a learning curve. Blood loss was minimal and no procedure related complications were seen.

Conclusion

Using these minimal invasive endoscopic approaches, it seems feasible to externally band aneurysm necks and ligate aortic side branches in a pig model. These procedures could potentially be considered as alternatives to OCs in controlling endoleaks and in improving the safety of endovascular interventions. As endoscopic aortic surgery is challenging a learning curve is expected. Practicing the described procedures using this model, can be used as a learning tool prior to similar interventions on humans.

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Laparo-/thoracoscopic approaches for treating endoleaks can be simulated in a pig model.

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Laparo-/thoracoscopic approaches to optimize a challenging aortic aneurysm neck can be simulated in a pig model.

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Endoscopic aortic surgery is challenging and a learning curve must be expected.

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A pig model with aortic aneurysm can be used as a realistic surgical learning tool before human application.

Late Conversion After Sac Anchoring Endoprosthesis for Secondary Aortic Aneurysm Infection

PURPOSE

To demonstrate explantation of the Nellix Endovascular Aneurysm Sealing (EVAS) System in the setting of infection.

CASE REPORTS

Two male patients, 71 and 83 years old, underwent Nellix implantation for asymptomatic infrarenal aortic aneurysms measuring 5.1 and 6.3 cm, respectively. Each developed late infections at 8 and 4 months post EVAS, respectively. The first patient experienced aneurysm rupture after medical therapy failed; the Nellix endosystem was explanted in an uneventful procedure. The second patient developed an aortoduodenal fistula, which was sutured before the Nellix device was removed without complications. The patient died 3 months later, presumably due to ongoing infection.

CONCLUSION

The need to explant a Nellix EVAS System due to graft infection is a straightforward procedure compared to the removal of a conventional endograft with suprarenal fixation. It requires only temporary suprarenal clamping. The devices can be easily removed due to the lack of penetrating components and without damage to the aortic segment needed to create an anastomosis.