Prevalence of type II endoleak after elective endovascular aneurysm repair with polytetrafluoroethylene- or polyester-based endografts.

OBJECTIVE: Type II endoleak is the most frequent complication after endovascular abdominal aneurysm repair. Polytetrafluoroethylene and polyester (PE) are the two most commonly used graft materials in endovascular aneurysm repair (EVAR) devices. Biological properties of the material might influence the appearance and persistence of type II endoleak (T2EL). Therefore, the aim of this study was to evaluate potential differences in the prevalence of T2EL after EVAR between polytetrafluoroethylene (PTFE) and PE endografts in patients electively treated for an infrarenal abdominal aortic aneurysm. METHODS: A single-center, retrospective, observational study was conducted between January 2011 and January 2022. Preoperative, procedural, and follow-up data were derived from electronic health records. Imaging included computed tomography scans, and/or duplex ultrasound examination. The primary end point was the prevalence of T2EL diagnosed within 1 year after EVAR. Secondary end points included the prevalence of T2EL throughout follow-up, early (≤30 days) and late (>30 days) T2EL, the rate of T2EL disappearance during the follow-up period, the prevalence of type I and III endoleak, and T2EL-related reinterventions. RESULTS: Follow-up was available for 394 patients, 245 in the PE and 149 in the PTFE group. The prevalence of T2EL diagnosed within 1 year after endovascular repair was 11.8% in the PE group and 21.5% in the PTFE group (P = .010). There was no significant difference in early (≤30 days) and late (>30 days) T2EL between groups (P = .270 and P = .311). There was no difference in the freedom from endoleak type II reinterventions between groups (P = .877). CONCLUSIONS: The prevalence of T2EL after elective EVAR is significantly higher with the use of PTFE-based endografts compared with PE-based endografts. This difference is mostly based on T2EL diagnosed after 30 days of follow-up.

Multicenter Comparative Analysis of Late Open Conversion in Patients With Adherence and Nonadherence to Instructions for Use Endovascular Aneurysm Repair.

PURPOSE: The widespread adoption of endovascular aneurysm repair (EVAR) as preferred treatment modality for abdominal aortic aneurysm (AAA) has enlarged the number of patients needing open surgical conversion (OSC). The relationship between adherence to Instructions For Use (IFU) and EVAR long-term outcomes remains controversial. The aim of this study is to compare preoperative differences and postoperative outcomes between EVAR patients not adjusted to IFU and adjusted to IFU who underwent OSC. METHODS: This multicenter retrospective study reviewed 33 explanted EVARs between January 2003 and December 2019 at 14 Vascular Units. Patients were included if OSC occurred >30 days after implantation and excluded if explantation was performed to treat an endograft infection, aortic dissection, or traumatic transections. Variables analyzed included baseline characteristics, adherence to IFU, implant and explant procedural details, secondary reinterventions, and postoperative outcomes. RESULTS: Fifteen explanted patients (15/33, 45.5%) were identified not accomplished to IFU (out-IFU) at initial EVAR vs 18 explanted patients adjusted (in-IFU). During follow-up, a mean of 1.73±1.2 secondary reinterventions were performed, with more type I endoleaks treated in the subgroup out-IFU: 16.7% vs 6.3% in-IFU patients and more type III endoleaks (8.3% vs 0%). Patients out-IFU had shorter mean interval from implant to explant: 47.60±28.8 months vs 71.17±48. Type II endoleak was the most frequent indication for explantation. Low-flow endoleaks (types II, IV, V) account for 44% of indications for OSC in subgroup of patients in-IFU, compared with 13.3% in patients out-IFU and high-flow endoleaks (types I and III) were the main indication for patients out-IFU (33.3% vs 16.7% in-IFU). Total endograft explantation was performed in 57.5% of cases (19/33) and more suprarenal clamping was required in the subgroup out-IFU. Overall, 30-day mortality rate was 12.1% (4/33): 20% for patients out-IFU and 5.6% in-IFU. CONCLUSIONS: In our experience, type II endoleak is the most common indication for conversion and differences have been found between patients treated outside IFU with explantation taking place earlier during follow-up, mainly due to high-flow endoleaks and with higher mortality in comparison with patients adjusted to IFU. Ongoing research is required to delve into these differences.

A systematic review of treatment modalities and outcomes of type Ib endoleak after endovascular abdominal aneurysm repair.

Objectives To collect specific literature on type Ib endoleak after aorto-iliac endografting for abdominal aortic aneurysm, reporting data on diagnosis, treatment, and follow-up results. Methods Publications about type Ib endoleak after aorto-iliac endografting for abdominal aortic or iliac aneurysm were searched in PubMed, Web of Science, and Scopus. Considered studies were in English and published until 3 November 2016. Research methods and reporting were performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Inclusion criteria were: (1) reporting on abdominal aortic or iliac aneurysm as primary diagnosis; (2) reporting on distal endoleak after aorto-iliac endografting. Patient data, data on endovascular treatment, endoleak, reintervention, and follow-up were collected by two independent authors. Results Included studies were 11 (five original articles, six case reports), corresponding to 29 patients and 30 type Ib endoleak. Excluding missing data (2/30, 6.7%), type Ib endoleak was treated intra-operatively, within six months and after six months in six cases (21.4%), eight cases (28.6%), and fourteen cases (50%), respectively. Treatment of type Ib endoleak was endovascular in 27 cases (90%) (7 embolizations + extender cuffs, 10 extender cuffs, 8 embolizations without extender cuff, 1 Palmaz stenting and 1 iliac branched endograft), hybrid in 1 case (3.3%) and surgical in 2 cases (6.6%). Buttock claudication occurred in two cases (6.7%). One-month mortality was 3.4% (2/29) without events due to type Ib endoleak. In 14 cases (46.7%), median follow-up was six months (interquartile range: 2.75-14; range: 0.75-53). Type Ib endoleak persisted or reappeared in three cases (10%), all after endovascular treatment. Two of these (2/3, 66.7%) needed endovascular reintervention. No death during follow-up was reported. Conclusions Few specific data are available in literature about type Ib endoleak after aorto-iliac endografting for abdominal aortic aneurysm. About 50% of type Ib endoleak occurred after six months from the endovascular abdominal aneurysm repair procedure. Treatment is mainly endovascular and distal endograft extension is the main and effective treatment. Buttock claudication is the most frequent complication in case of exclusion of internal iliac artery. Persistent type Ib endoleak is possible, and adjunctive endovascular procedures are necessary.

Predictive Factors for Iliac Limb Occlusions After Endovascular Abdominal Aneurysm Repair: Determined from Aortoiliac Anatomy, Endovascular Procedures, and Aneurysmal Remodeling.

Purpose: Iliac limb occlusion (ILO) is a serious complication of endovascular abdominal aneurysm repair (EVAR). This study aimed to identify predictive factors for ILO derived from aortoiliac morphology, endovascular procedure-related parameters, and aneurysmal remodeling characteristics. Patients and Methods: Patient demographics, pre-EVAR anatomical characteristics of the aneurysm, endovascular procedure details, and post-EVAR aneurysmal remodeling outcomes were analyzed and compared using univariate analysis. Statistically significant factors were subsequently subjected to Cox regression and Kaplan-Meier analyses. Results: Between January 2013 and April 2022, 66 patients were included in this study. Fourteen patients presented with ILO and were compared with 52 control patients with patent endograft limb over at least 1-year of follow-up. The tortuosity indices of the common iliac artery (CIA) and endograft iliac limb to vessel oversizing were significantly larger in the ILO group than in the patent endograft limb group. The CIA index of tortuosity ≥1.08, and endograft iliac limb to vessel oversizing ≥18.8% were independent predictors for ILO. During the follow-up of all patients, the proximal aortic neck and CIA diameters increased, aneurysm sac diameter decreased, and aortic neck and aortic length increased. The aortoiliac length increased over time in patients with patent endograft limb but not in patients with ILO. A change in the lowest renal artery-left iliac bifurcation distance ≦0.07 mm increased the risk of ILO. Conclusion: ILO is predisposed to occur when the CIA index of tortuosity ≥1.08 and endograft iliac limb to vessel oversizing ≥18.8% are present. Significant aortoiliac remodeling, including proximal aortic neck dilatation, neck straightening, aneurysmal sac regression, iliac artery enlargement, and aortic lengthening, occurs after EVAR. Aortoiliac elongation was observed in patients with patent endograft limb, but not in patients with ILO. ILO was associated with a change in the lowest renal artery-left iliac bifurcation from the postoperative measurements ≦ 0.07 mm.

Endovascular aneurysm repair with mesenteric artery bypass for abdominal aortic aneurysm with occlusion of celiac and superior mesenteric arteries.

A 67-year-old male patient required surgical management of an abdominal aortic aneurysm. Contrast-enhanced computed tomography showed a saccular infrarenal abdominal aortic aneurysm and occlusion of the origins of the celiac artery, superior mesenteric artery, and inferior mesenteric artery. Aortography revealed large amounts of blood flow from capillaries around the abdominal aorta to the inferior mesenteric artery and retrograde blood flow to a meandering mesenteric artery through the superior rectal artery. Considering the risk of bowel ischemia, we performed endovascular aneurysm repair with mesenteric artery bypass. The operation was successful, and his postoperative course was uneventful. This procedure could be useful and less invasive.

Intermediate pressure-normalized principal wall strain values are associated with increased abdominal aortic aneurysmal growth rates.

Introduction: Current abdominal aortic aneurysm (AAA) assessment relies on analysis of AAA diameter and growth rate. However, evidence demonstrates that AAA pathology varies among patients and morphometric analysis alone is insufficient to precisely predict individual rupture risk. Biomechanical parameters, such as pressure-normalized AAA principal wall strain (ερ+¯/PP, %/mmHg), can provide useful information for AAA assessment. Therefore, this study utilized a previously validated ultrasound elastography (USE) technique to correlate ερ+¯/PP with the current AAA assessment methods of maximal diameter and growth rate. Methods: Our USE algorithm utilizes a finite element mesh, overlaid a 2D cross-sectional view of the user-defined AAA wall, at the location of maximum diameter, to track two-dimensional, frame-to-frame displacements over a full cardiac cycle, using a custom image registration algorithm to produce ερ+¯/PP. This metric was compared between patients with healthy aortas and AAAs (≥3 cm) and compared between small and large AAAs (≥5 cm). AAAs were then separated into terciles based on ερ+¯/PP values to further assess differences in our metric across maximal diameter and prospective growth rate. Non-parametric tests of hypotheses were used to assess statistical significance as appropriate. Results: USE analysis was conducted on 129 patients, 16 healthy aortas and 113 AAAs, of which 86 were classified as small AAAs and 27 as large. Non-aneurysmal aortas showed higher ερ+¯/PP compared to AAAs (0.044 ± 0.015 vs. 0.034 ± 0.017%/mmHg, p = 0.01) indicating AAA walls to be stiffer. Small and large AAAs showed no difference in ερ+¯/PP. When divided into terciles based on ερ+¯/PP cutoffs of 0.0251 and 0.038%/mmHg, there was no difference in AAA diameter. There was a statistically significant difference in prospective growth rate between the intermediate tercile and the outer two terciles (1.46 ± 2.48 vs. 3.59 ± 3.83 vs. 1.78 ± 1.64 mm/yr, p = 0.014). Discussion: There was no correlation between AAA diameter and ερ+¯/PP, indicating biomechanical markers of AAA pathology are likely independent of diameter. AAAs in the intermediate tercile of ερ+¯/PP values were found to have nearly double the growth rates than the highest or lowest tercile, indicating an intermediate range of ερ+¯/PP values for which patients are at risk for increased AAA expansion, likely necessitating more frequent imaging follow-up.

Endovascular aneurysm repair with mesenteric artery bypass for an abdominal aortic aneurysm with occlusion of celiac and superior mesenteric arteries.

A 67-year-old male patient required surgical management of an abdominal aortic aneurysm. A contrast-enhanced computed tomography showed a saccular infrarenal abdominal aortic aneurysm, with occlusion of the origins of the celiac artery, superior mesenteric artery, and inferior mesenteric artery. An aortography revealed large amounts of blood flow from capillaries around the abdominal aorta to the inferior mesenteric artery and retrograde blood flow to the meandering mesenteric artery through the superior rectal artery. Considering the risk of bowel ischemia, we performed endovascular aneurysm repair with mesenteric artery bypass. The operation was successful, and the postoperative course was uneventful. This procedure may be useful and less invasive.

Endovascular Treatment of Aorta-Iliac Aneurysms with a Flared Iliac Limb.

Endovascular abdominal aneurysm repair (EVAR) relies on the quality of the proximal and distal landing zone. Reinterventions are higher in patients with suboptimal landing zone. The study aimed to evaluate reintervention rate after endovascular treatment of an aorta-iliac aneurysm using the flared iliac limbs. The retrospective study included 179 patients treated with EVAR at a single university hospital institution from January 2011 to January 2014 of which 75 patients (42%) were treated with flared iliac limb stent graft and 104 patients (58%) were treated with a nonflared iliac limb stent graft. There were 165 male patients (92%), mean age was 75.8 ± 6.6 years. Thirty-six patients underwent secondary treatment accounting for overall reintervention rate of 20%. Endoleak type 1b occurred in 13 patients (7%), followed by endoleak type 1a in six patients (3%). Endoleak type 2 occurred in seven patients (4%) requiring the treatment due to abdominal aortic aneurysm (AAA) enlargement, endoleak type 3 in three patients (2%), and leg stent graft thrombosis in seven patients (4%). In 143 patients (80%), there were no secondary interventions during the follow-up period. Reintervention due to endoleak type 1b was statistically significantly higher in a flared iliac limb group ( p < 0.02) with the rate of 7.2% compared with 1.9% rate in nonflared iliac limb group. The mean follow-up was 44.3 ± 20.4. Overall mortality was 33%. Flared iliac limb with a distal diameter of ≥ 20 mm, show a higher rate of iliac limb reintervention in a follow-up period due to endoleak type 1b.

Contemporary imaging methods for the follow-up after endovascular abdominal aneurysm repair: a review.

Abdominal aortic aneurysm (AAA) is defined as a localized enlargement of the aortic cross-section where the diameter is greater than 3 cm or more than 50% larger than the diameter in a normal segment. The most important complication of AAA is rupture, which, if untreated, results in mortality rates of up to 90%. Conventional open surgical repair is associated with significant 30-day mortality. Endovascular aneurysm repair (EVAR) is a significantly less invasive procedure; it is related to a lower early mortality rate and a lower number of perioperative complications. Although EVAR is a minimally invasive technique, lifelong follow-up imaging is necessary due to possible late complications including endoleak, recurrent aneurysm formation, graft infection, migration, kinking and thrombosis. The total rate of complications after EVAR is estimated at approximately 30%, and the rate of complications that require intervention is 2-3%. Early detection and progression analysis of such situations is crucial for proper intervention.

Surgical management of abdominal aortic aneurysms: a lost art?

Endovascular repair of abdominal aneurysms has become the dominant treatment modality for infrarenal aneurysms. Initial reports showed a constant number of open repairs although there was a shift toward complicated juxtra-renal aneurysms. In the past several years, more aggressive endoluminal approaches and the introduction of fenestrated grafts have appeared to dilute the open aneurysm operating experience. Coupled with work hours restrictions and shorter training paradigms, opportunities for training residents in open repair of abdominal aneurysms are decreasing. We envision that future treatment of complicated aortic aneurysms will likely entail advanced fellowship training in open repair and referral of complicated abdominal aneurysms to tertiary care centers.