Peter L. Harris

Fenestrated endovascular aneurysm repair

Fenestrated endovascular aneurysm repair (FEVAR) is a technically challenging operation. The duration, blood loss, and risk of limb ischaemia, contrast‐induced nephropathy and reperfusion injury are likely to be higher than after standard endovascular aneurysm repair (EVAR). Benefits of FEVAR over open repair may be less than those seen with standard infrarenal EVAR. This paper is a meta‐analysis of observational studies of all published data for FEVAR, with the aim to highlight current issues around the evidence for the potential benefit of FEVAR.

In situ fenestration in the aortic arch

In situ fenestration of aortic stent grafts has the potential to allow for continued perfusion of supra-aortic trunks, without the need for extra-anatomic bypass, and without the need for custom-made devices. Angulation of the target vessel relative to the arch is an obstacle to success with this technique. In this report, we describe a case of successful in situ fenestration of the left subclavian artery (LSA) in a patient with an aortic arch aneurysm, treated with an endovascular stent graft. We outline a novel technique using through and through wire access and a pre-curved semi-rigid sheath, which allows successful access to the lumen of the aortic stent graft, despite an acute angle at the take-off of the LSA.

Early Outcome Following Endovascular Repair of Pararenal Aortic Aneurysms: Triple-Versus Double- or Single-Fenestrated Stent-Grafts

Purpose: To review the early outcome following endovascular repair of pararenal aortic aneurysm using fenestrated stent-grafts and to determine if the number of fenestrations required is predicative of outcome. Methods: A retrospective analysis was conducted of 20 consecutive patients (18 men; mean age of 75±7 years) treated with stent-grafts containing either ≥2 fenestrations (n = 10, group 1) or 3 fenestrations (n = 10, group 2). Target vessels also included those accommodated by a scallop (renal artery or superior mesenteric artery in group 1 and the celiac artery in group 2). Results: Comorbidities were similar in both groups. Aneurysm size [median 6.9 (IQR 6.7-8.3) versus 6.0 cm (IQR 5.8-6.6), p=0.03], procedure time (mean 6.6±2.1 versus 4.6±1.7 hours, p=0.04), and intensive care stay [median 4.5 (IQR 2-14) versus 2 (IQR 1-3) days, p=0.07] were greater in group 2. There were 2 postoperative deaths, both in group 2. Morbidity was significant and similar in both groups (4 patients in group 1 and 3 patients in group 2), including 1 patient requiring long-term hemodialysis. Target vessel preservation was similar in both groups (96% overall). There were 2 type II endoleaks (one in each group) and no type I or III endoleak. Conclusion: Triple-fenestrated stent-grafts allow patients with extensive pararenal aneurysms and significant comorbidity to be treated by endovascular means. Although the number of patients treated was small, which limited the validity of the comparison, longer procedures and greater early morbidity and mortality were seen in the triplefenestrated group. At present, the procedures are technically more demanding and associated with increased risk compared with double or single fenestrations, but the technology continues to evolve.

Placement of a branched stent graft into the false lumen of a chronic type B aortic dissection

The treatment of chronic type B aortic dissections remains challenging and controversial. Currently most centers advocate open or endovascular intervention for patients with evidence of malperfusion, rupture or impending rupture, continued pain, or aneurysm formation. Regardless of the type of intervention, the incidence of complications or death remains high, even when undertaken in an elective setting. The standard endovascular treatment usually involves placement of a stent graft into the true lumen of the dissection in an effort to exclude the false lumen. This case report describes the placement of a branched stent graft into the false lumen of a patient with chronic type B dissection to encourage exclusion and thrombosis of the true lumen whilst maintaining flow to all visceral vessels.

Preloaded Fenestrated Stent-Grafts for the Treatment of Juxtarenal Aortic Aneurysms

Purpose: To describe a novel technique for target vessel catheterization in patients with juxtarenal abdominal aortic aneurysms requiring treatment with fenestrated stent-grafts (FSG). Methods: The standard FSG design was modified, substituting a thin-wall tube for the solid central obturator that serves as both an attachment point for the distal end of the graft as well as a top cap retriever. Through this tube, two 0.020-inch wires are run from the hub of the delivery system through the stent-graft, out through each fenestration, and up to the proximal edge of the graft, where they are attached by sutures. The sutures are connected to a trigger wire on the control hub. The preloaded wires facilitate passage of a sheath to the fenestration, providing stability while target vessel catheterization takes place and avoiding the use of a large sheath in the contralateral groin. A third wire attached to the inside of the top cap facilitates its safe retrieval via a 6-mm balloon. The preloaded FSG was used in 5 male patients (mean age 75.6 years) with either juxtarenal aneurysms (n=2) or aneurysms previously treated with infrarenal stent-grafts that had developed type I endoleak (n=3). In 3 cases, a double fenestrated stent-graft was required, and in 2 cases a triple fenestrated device was deployed, with scallops for the superior mesenteric or celiac arteries. Results: Sixteen of 17 target vessels were preserved, and all aneurysms were successfully excluded with no endoleak at completion. In 2 patients, tortuosity encountered during device delivery caused twisting of the wires within the preloaded FSG, preventing successful advancement of a sheath over a preloaded wire. An approach from the contralateral groin was necessary to complete the procedure in 1 case, but the target vessel was lost in the other. Conclusion: The use of a preloaded FSG is feasible and facilitates the catheterization of fenestrations and of target arteries. This method has the potential to reduce procedure times and lower the risk of intraoperative lower limb ischemia.

Temporary axillobifemoral bypass as an adjunct to endovascular aneurysm repair using fenestrated stent grafts.

Prolonged endovascular procedures requiring a large diameter sheath in each groin can be associated with significant intraoperative lower limb ischemia, particularly in those with pre-existing peripheral vascular disease. We report the case of a patient who suffered severe ischemia-reperfusion injury following endovascular repair of a pararenal aortic aneurysm using a fenestrated stent graft and describe the use of temporary axillobifemoral bypass in a patient with similar comorbidities undergoing the same procedure. We propose this adjunctive technique as a means of maintaining antegrade limb perfusion and avoiding the peripheral and central metabolic consequences of ischemia-reperfusion injury.