An unusual cause of failure in Zenith Alpha Abdominal endograft

Background

Graft disruption is an unusual complication of the endovascular abdominal aortic aneurysm repair (EVAR).

Case presentation

A 71-year-old man underwent standard EVAR with Zenith Alpha Abdominal endograft. Follow-up examinations revealed an initial significant sac shrinkage. At 24 months, duplex ultrasound (DUS) scan and computed tomography showed increase of the sac diameter associated with complete disconnection of the suprarenal stent-graft from the main body without evidence of endoleak. A standard relining with a thoracic endograft was performed between the suprarenal stent and the main body of the previous graft. At 6 months DUS revealed sac shrinkage.

Conclusions

This report demonstrates an uncommon cause of endograft failure with suprarenal stent disconnection from main body and highlights the need for continuous follow-up in patients undergoing EVAR.

A Systematic Review on Methods and Tools for the In Situ Fenestration of Aortic Stent-Graft

In situ fenestration of stent-graft represents a potential option for the treatment of aortic diseases in patients unsuitable for standard endovascular repair. The best fenestration strategy to restore perfusion of collateral vessels after their coverage by an endograft depends mainly on the anatomical area. Several tools are employed as fenestration devices, including needles, radiofrequency probes, and laser systems, used in conjunction with other instrumentation to provide enough support and stability during the procedure. In this systematic review, the approaches to reach the correct fenestration site both in human, animal, and in in vitro environments are described and discussed, highlighting advantages and limitations. Both commercial and dedicated solutions for the intraoperative modification of the fabric material are reported as well. The clinical interest in this procedure has so far encouraged researchers to develop and refine both methods and tools to solve the current limitations of this technique, intending to extend the indications for endovascular treatment to a broader range of patients.

Bifurcated bypass in severe chronic limb threatening ischaemia

OBJECTIVES

Revascularization according to the angiosome concept is of proven importance for limb salvage in chronic limb threatening ischaemia but it is not always practicable. Bifurcated bypasses could be considered as an option when an endovascular approach is not feasible or has already failed and a single bypass would not allow direct revascularization of the ischaemic area. Bifurcated bypasses are characterized by landing on two different arteries, the main artery (in direct continuity with the foot vessels) and the secondary one (perfusing the angiosome district). The aim of this study is to evaluate the safety and effectiveness of bifurcated bypass in chronic limb threatening ischaemia.

METHODS

Thirty-five patients were consecutively treated with a bifurcated bypass for chronic limb threatening ischaemia from January 2014 to December 2019 in a single vascular surgery centre. Data from clinical records and operative registers were collected prospectively in an electronic database and retrospectively analysed. Primary and primary assisted bypass patency, amputation-free survival, morbidity and mortality rates at 12 and 24 months were analysed.

RESULTS

Mean follow-up period was 25.1 months (range 2-72 months). Thirty-six bifurcated bypasses were performed on 35 patients (age 75.3 ± 7.2 years; 69.4% were male). According to Wound, Ischemia, foot Infection classification 22.2% belonged to stage 3 and 77.8% to stage 4 and the mean Rutherford's class was 5.1 ± 0.7. Immediate technical success was 100%. Early mortality and morbidity rates were respectively 5.5%, and 33.3%; foot surgery was performed in 50% of cases with wound healing in all patients. Primary patency and primary assisted bypass patency were 96.7% and 100% at 6 months; 85.2% and 92% at 12 months, 59.9% and 73.4% at 24 months, respectively. Amputation-free survival at 12 and 24 months was, respectively, 95.6% and 78.8%. Overall survival rates at 12 and 24 months were respectively 94.4% and 91.6%.

CONCLUSIONS

Bifurcates bypass can provide good results in patients with chronic limb threatening ischaemia without endovascular option, especially in diabetic ones. Bifurcated bypass is a complex surgical solution, both to be planned and performed, and it is quite invasive for frail patients that should be accurately selected.

Novel EM Guided Endovascular Instrumentation for In Situ Endograft Fenestration

Objective: This work aims at providing novel endovascular instrumentation to overcome current technical limitations of in situ endograft fenestration including challenges in targeting the fenestration site under fluoroscopic control and supplying mechanical support during endograft perforation. Technology: Novel electromagnetically trackable instruments were developed to facilitate the navigation of the fenestration device and its stabilization at the target site. In vitro trials were performed to preliminary evaluate the proposed instrumentation for the antegrade in situ fenestration of an aortic endograft, using a laser guidewire designed ad hoc and the sharp end of a commercial endovascular guidewire. Results: In situ fenestration was successfully performed in 22 trials. A total of two laser tools were employed since an over bending of laser guidewire tip, due to its manufacturing, caused the damage of the sensor in the first device used. Conclusions: Preliminary in vitro trials demonstrate the feasibility of the proposed instrumentation which could widespread the procedure for in situ fenestration. The results obtained should be validated performing animal studies. Clinical Impact: The proposed instrumentation has the potential to expand indications for standard endovascular aneurysm repair to cases of acute syndromes.

In situ diode laser fenestration: An ex-vivo evaluation of irradiation effects on human aortic tissue

The in situ laser fenestration is an interesting option for the endovascular treatment of short-necked aneurysms with an intraoperative modification of a standard endograft. According to literature evidence, diode laser emitting in the near-infrared wavelength (810 nm) can be successfully used to fenestrate the endograft fabric. This paper describes a three-dimensional navigation system for the accurate targeting of the fenestration site, then reports results of an ex vivo study to assess whether the laser operative conditions, which ensure the fabric fenestration, are harmless for the biological tissue surrounding the endoprosthesis. Two hundred twenty-five samples of human aorta, including healthy specimens and abdominal aortic aneurysm samples, were irradiated ex vivo using a 810 nm diode laser. Energy and pulse duration were varied. Irradiated tissues were fixed in formaldehyde, sectioned and subjected to histological examination. Only 7.5% of the irradiated samples exhibited a thermal damage, which was always confined to the contact point between the laser fiber tip and the aortic wall. These experiments suggest that the diode laser can be safely used for the proposed surgical application.

Hybrid procedures and femoral endarterectomy in diabetic patients

OBJECTIVE

The aim of the study is to evaluate the safety and effectiveness of common femoral endarterectomy (CFE) in critical limb ischemia (CLI) associated with proximal and distal endovascular (EV) revascularization in diabetic (type 1 and type 2) and non-diabetic patients.

PATIENTS AND METHODS

We analyzed patients from January 2008 to December 2011 who underwent one-staged hybrid procedures. Patients were divided into three groups: group 1 = EV reconstruction proximal to the CFE, group 2 = EV procedures distal to the CFE, group 3 = both proximal and distal EV procedures. Patients were evaluated at 6 and 36 months after the procedures, and the mean follow-up was 42 ± 20.3 months.

RESULTS

A total of 43 (79% men; aged 74.4 ± 8.6 years) out of 635 (5.5%) patients operated for CLI fulfilled the inclusion criteria; 23 (53.5%) had type 1 or type 2 diabetes mellitus (DM). DM patients were younger than controls (p = 0.048). The patient distribution was 14 in Group 1 (32.5%), 24 in Group 2 (55.8%) and 5 in Group 3 (11.7%). CFE was successful in all cases, while associated EV procedures were successful in 90.7% of patients. Peri-operative morbidity and mortality were 11.6% and 2.3%, respectively. Survival rates at 6 and 36 months were 93% and 71.9%, respectively. Three patients (6.98%) underwent a major amputation. The cumulative limb salvage was 95.2% at 6 months and 92.1% at 36 months. No recurrent CFE stenosis was observed. No differences in survival, amputation or patency rates emerged between DM and non-DM patients or among the three EV revascularization groups.

CONCLUSIONS

Hybrid procedures are safe and effective both in CLI patients with or without DM, and they should be taken into consideration whenever indications are present.