Endovascular repair of late type IIIb endoleak after endovascular aneurysm repair: a case report

Giant Sac Growth: A Hybrid Approach to Treat a Misdiagnosed Late Type IIIb Endoleak

Introduction

Endoleaks are a common complication following endovascular aneurysm repair, yet type IIIb are rare, especially with newer devices, and associated with high morbidity due to repressurisation of the sac. As endografts are used in patients with longer life expectancy, late type IIIb endoleaks are to be expected. This is a report of a giant common iliac aneurysm resulting from a misdiagnosed type IIIb endoleak.

Report

An 85 year old man with history of right common iliac artery aneurysm, treated in 2003 with an EXCLUDER AAA Endoprosthesis (WL Gore, Flagstaff, AZ, USA) with iliac limb extension into the external iliac artery, presented at the emergency department with abdominal pain, hypotension, and syncope. He had a known endoleak, unsuccessfully treated by relining the right iliac stent graft overlap zones for a suspected type IIIa endoleak (2009), coil embolisation, and computed tomography (CT) guided thrombin injection of the aneurysmatic sac for a type II (2010), none of which managed to treat the cause with continuous aneurysm growth. The patient refused further treatments, but agreed to maintain surveillance. At admission, CT angiography showed common iliac aneurysm (185 × 134 mm) sac rupture without a visible endoleak. Resuscitative endovascular balloon occlusion of the aorta (REBOA) technique was performed to obtain haemodynamic control, then the aneurysm was approached through a midline incision. A type IIIb endoleak was identified due to a fabric tear on the right iliac limb extension. Suture was attempted without success, then relining of the lesion with an Endurant II Limb (Medtronic, Minneapolis, MN, USA) was performed, which managed to repair the endoleak.

Discussion

Type IIIb endoleaks are uncommon and underdiagnosed due to fabric defects being too small or leaking intermittently. They can mimic other types of endoleaks and may cause aneurysm growth and rupture. One should consider this type of endoleak if previous treatments for other types were unsuccessful.

A preliminary analysis of late structural failures of the Navion stent graft in the treatment of descending thoracic aortic aneurysms

OBJECTIVE

Patients in the Valiant Evo U.S. and international clinical trials had positive short-term outcomes; however, late structural failures, including type IIIb endoleaks have been recently discovered. Type IIIb endoleaks are serious adverse events because the repressurization of the aneurysm sac increases the risk of rupture. The purpose of the present study was to detail the imaging patterns associated with the structural failures with the aim of increasing awareness of failing graft presentation, early recognition, and prompt treatment.

METHODS

The Valiant Evo clinical trial was a prospective, single-arm investigation of a thoracic stent graft system. With the recent late structural failures, sites were requested to submit all available imaging studies to date to allow the core laboratory to assess for structural failures such as type IIIb endoleaks, stent ring fractures, and stent ring enlargement. Of the 100 patients originally enrolled in the trial from 2016 to 2018, the core laboratory assessed the imaging studies performed at ≥1 year for 83 patients.

RESULTS

No structural failures of the graft were reported through 1 year of follow-up. At 1 to 4 years, graft structural failures were detected in 11 patients with descending thoracic aortic aneurysms. Of the 11 patients, 5 had a type IIIb endoleak. Four of the five had imaging findings showing stent fractures consistent with the location of the graft seam and one had a type IIIb endoleak attributed to calcium erosion with no stent fracture or ring enlargement. Of the four patients with stent fracture in line with the graft seam, three underwent a relining procedure that successfully excluded the type IIIb endoleak. One of these three patients died 4 days later of suspected thoracic aortic rupture because the distal thoracic endovascular aortic repair extension had been landed in a previously dissected and fragile section of the aorta. The remaining six patients had had stent ring enlargement. One of the six patients had had persistent aneurysm expansion from the time of implantation onward and had died of unknown causes. The remaining five patients have continued to be monitored.

CONCLUSIONS

In the present preliminary analysis, the imaging patterns associated with type IIIb endoleaks, stent fractures, and stent ring enlargement appear to be related to the loss of seam integrity or detachment of the stent rings from the surface of the graft material. The imaging patterns we have detailed should be closely monitored using computed tomography angiography surveillance to allow structural failures to be promptly identified and treated.