Technical and clinical success of infrarenal endovascular abdominal aortic aneurysm repair: A 10-year single-center experience

Type IIIb endoleak after elective endovascular aneurysm repair: a systematic review

INTRODUCTION

The aim of this article is to investigate the presentation, etiology, management and outcomes of type IIIb endoleak after endovascular aneurysm repair (EVAR).

EVIDENCE ACQUISITION

Electronic bibliographic databases were searched to identify published reports of type IIIb endoleak after EVAR, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards.

EVIDENCE SYNTHESIS

In total 33 articles were identified reporting on a total of 50 patients spanning 19 years of EVAR (1998-2017). Some 11 device-types were used. The median time from implantation to intervention was 27 months (0-168). There was a significant aneurysm sac expansion in 69% of reported cases. Thirteen patients (26%) presented with aneurysm rupture. A definitive diagnosis of type IIIb endoleak made on computed tomographic angiography (CTA) in only 20% of cases. Proposed failure modes included suture breakage, graft erosion by stents, iatrogenic, graft infection and presumed manufacturing faults. Endoleak location was in the main body in 81% of reported cases. Almost one third (31%) of patients were treated with open repair. The remaining patients were treated with endovascular techniques or hybrid procedures. Some novel off-label endovascular solutions were proposed to maintain a bifurcated configuration. Thirty-day mortality in patients treated for aneurysm rupture was 50%. The 30-day mortality rate in non- rupture cases was 2% (endovascular 0% treatment, open 2%).

CONCLUSIONS

Type IIIb endoleak is a serious condition associated with a significant risk of rupture. Definitive diagnosis is challenging and has been described in almost all conventional devices. Most patients can be treated successfully by endovascular means, though maintaining a bifurcated configuration may require non-standard techniques or off-label use.

Abdominal aortic aneurysm follow-up by shear wave elasticity imaging after endovascular repair in a canine model

OBJECTIVES

To investigate if shear wave imaging (SWI) can detect endoleaks and characterize thrombus organization in abdominal aortic aneurysms (AAAs) after endovascular aneurysm repair.

METHODS

Stent grafts (SGs) were implanted in 18 dogs after surgical creation of type I endoleaks (four AAAs), type II endoleaks (13 AAAs) and no endoleaks (one AAA). Color flow Doppler ultrasonography (DUS) and SWI were performed before SG implantation (baseline), on days 7, 30 and 90 after SG implantation, and on the day of the sacrifice (day 180). Angiography, CT scans and macroscopic tissue sections obtained on day 180 were evaluated for the presence, size and type of endoleaks, and thrombi were characterized as fresh or organized. Endoleak areas in aneurysm sacs were identified on SWI by two readers and compared with their appearance on DUS, CT scans and macroscopic examination. Elasticity moduli were calculated in different regions (endoleaks, and fresh and organized thrombi).

RESULTS

All 17 endoleaks (100 %) were identified by reader 1, whereas 16 of 17 (94 %) were detected by reader 2. Elasticity moduli in endoleaks, and in areas of organized thrombi and fresh thrombi were 0.2 ± 0.4, 90.0 ± 48.2 and 13.6 ± 4.5 kPa, respectively (P < 0.001 between groups). SWI detected endoleaks while DUS (three endoleaks) and CT (one endoleak) did not.

CONCLUSIONS

SWI has the potential to detect endoleaks and evaluate thrombus organization based on the measurement of elasticity.

KEY POINTS

• SWI has the potential to detect endoleaks in post-EVAR follow-up. • SWI has the potential to characterize thrombus organization in post-EVAR follow-up. • SWI may be combined with DUS in post-EVAR surveillance of endoleak.

An Uncommon Case of Type III Endoleak Treated with a Custom-made Thoracic Stent Graft

Endovascular aortic repair (EVAR) has been shown to be a valid and minimally invasive alternative to open abdominal aortic aneurysm repair. A major shortcoming for EVAR is the need to submit patients to regular follow-up to detect potential complications such as endoleak, limb occlusion, aneurysm expansion, aneurysm rupture, infection, structural failure, and migration. In this case report, we describe an uncommon case of late type III endoleak due to complete detachment of the stent-graft main body segment from its suprarenal uncovered fixation stent. It was treated with a custom-made Relay(®) NBS Plus (Bolton Medical, Barcelona, Spain) thoracic stent graft which also provided extra suprarenal fixation of the thoracic stent graft in the proximal neck. The postoperative period was uneventful and a computed tomography scan 1 year later revealed proper positioning of the stent graft and no signs of endoleak. The successful strategy chosen to correct this complication was at the same time original and infrequent, and also avoided potential complications related to open surgical repair and general anesthesia.

Late Type 3b Endoleak with an Endurant Endograft

Endovascular stent grafting with different commercially available stent graft systems is widely applied for the treatment of abdominal aortic aneurysms with high success rates in the current era. Various types of endoleaks are potential complications of the procedure. They usually occur in the early period. In this report, we present type 3b endoleak occurring 14 months after a successful endovascular abdominal aortic aneurysm repair with a Medtronic Endurant stent graft.

Stent graft performance in the treatment of abdominal aortic aneurysms: the influence of compliance and geometry

The long-term success of the endovascular procedure for the treatment of Abdominal Aortic Aneurysms (AAAs ) depends on the secure fixation of the proximal end and the geometry of the stent-graft (SG) device. Variations in SG types can affect proximal fixation and SG hemodynamics. Such hemodynamic variations can have a catastrophic effect on the vascular system and may result from a SG/arterial wall compliance mismatch and the sudden decrease in cross-sectional area at the bifurcation, which may result in decreased distal perfusion, increased pressure wave reflection and increased stress at the interface between the stented and non-stented portion of the vessel. To examine this compliance mismatch, a commercial SG device was tested experimentally under a physiological pressure condition in a silicone AAA model based on computed tomography scans. There was a considerable reduction in compliance of 54% and an increase in the pulse wave velocity of 21%, with a significant amount of the forward pressure wave being reflected. To examine the SG geometrical effects, a commercial bifurcated geometry was compared computationally and experimentally with a geometrical taper in the form of a blended section, which provided a smooth transition from the proximal end to both iliac legs. The sudden contraction of commercial SG at the bifurcation region causes flow separation within the iliac legs, which is known to cause SG occlusion and increased proximal pressure. The blended section along the bifurcation region promotes a greater uniformity of the fluid flow field within the distal legs, especially, during the deceleration phase with reduced boundary layer reversal. In order to reduce the foregoing losses, abrupt changes of cross-section should be avoided. Geometrical tapers could lead to improved clinical outcomes for AAA SGs.

Three-year follow-up of fenestrated thoracoabdominal stent graft bridging an endovascular thoracic stent graft and a surgical abdominal aortic graft

This case report describes repair of a type I endoleak at the distal landing zone of a thoracic aortic stent graft by endovascular placement of a thoracoabdominal fenestrated stent graft (Cook, Brisbane, Australia). The fenestrated stent graft was interposed between a previous abdominal aortic aneurysm (AAA) Gelsoft tube graft (Sulzer Vascutek Ltd, Inchinnan, United Kingdom) and two overlapping Zenith thoracic endografts (Cook Inc, Bloomington, Indiana). Placement was made more complex because the distal thoracic endograft had rotated into a horizontal position. At 3-year clinical and computed tomography (CT) follow-up, continued clinical and radiologic success was shown with no further intervention required.

Evaluation of a new computerized analysis system developed for the processing of CT follow-up scans after EVR of infrarenal aneurysm

PURPOSE

The aim of this retrospective study was to present a new computerized analysis system developed for the evaluation of follow-up CT scans after endovascular repair (EVR) of infrarenal aneurysm and to compare it to the conventional evaluation method as regards preciseness and ease of application. The system is based on the extraction of the surface of the stent-graft (SG) and that of the spinal canal and the overlay of surfaces obtained at different points in time.

MATERIALS AND METHODS

A total of 116 CT follow-up data sets obtained from 49 patients after EVR of infrarenal aneurysm were evaluated using both, the conventional method and the new computerized system. Two parameters were analyzed: SG length and the distance between the most ventral point of the SG and the vertebral column. The correlation between the results of the two methods and the correlation between the results obtained by two independent observers (radiologist and lay person) using the new system were assessed by statistical analysis.

RESULTS

Comparison of the two methods yielded a very high correlation for both parameters, (correlation coefficients of around 0.9 and p<0.001). Comparison of the results obtained by the two observers yielded an equally high correlation (correlation coefficients of around 0.9 and p<0.001).

CONCLUSION

Our results show that the new computerized system is as precise and reliable as the conventional method, but allows better visualization and quantification of SG changes by surface overlay. Moreover, it is easier to apply and less time-consuming and can be easily integrated into existing systems.

Diagnosis of type III endoleak and endovascular treatment with aortouniiliac stent-graft

The present report describes a case of type III endoleak from a tear in the fabric of a Zenith bifurcated stent-graft approximately 6 months after implantation. The reason of the fabric tear was unknown. The complication was successfully treated by aortouniiliac stent-graft implantation followed by creation of a femorofemoral bypass.

Renal transplantation after endovascular repair of abdominal aortic aneurysm

An increasing number of abdominal aortic aneurysms (AAA) occur in renal failure patients because of strong association between atherosclerosis and chronic kidney disease. Endovascular aneurysm repair (EVAR) has proven to be an effective modality to treat AAA, particularly in patients with renal disease, because of its several advantages over the standard open procedure, including lower morbidity, shorter operative time, and shorter hospital stay. A Medline search showed a single publication on renal transplantation (RT) following EVAR of AAA. In this context, we report our case of successful RT in a patient who had undergone EVAR 2 years prior for a 5.7-cm AAA. No stent-related complications, such as graft occlusion, dislodgement, dissection, or endoleak, were observed in the perioperative period. The transplanted kidney had primary function leading to a stable serum creatinine of 115 micromol/L at 6 months. Although the long-term outcome of RT after endovascular repair of AAA remains unknown, currently available evidence shows favorable outcomes of EVAR in the normal population, in patients with renal diseases, and in RT recipients; hence, RT should not be denied to renal failure patients who have undergone EVAR in the past.