Possible graft-related complications in visceral debranching for hybrid B dissection repair

Abstract

Background: Hybrid repair (HR) of thoracoabdominal aortic aneurysm (TAAA) and dissection (TAAD), consisting of rerouting renovisceral branches followed by endograft aortic repair, has been shown to be a feasible option. It is especially appealing in patients unfit for both open and total endovascular repair. In order to determine the role of dissecting etiology and intraoperative variables as risk factors for graft-related complications in visceral debranching, we retrospectively analyzed the clinical outcomes, patency rate and hemodynamic alterations of the renovisceral debranching grafts in our series.

Methods: We analyzed 55 consecutive patients who underwent thoracoabdominal aortic HR between 2001 and 2013 in our center. Forty-four procedures were performed for TAAA and 11 procedures for TAAD. In TAAD patients, dissection involved 9/44 (20.5%) renovisceral vessels. One hundred and fifty-nine visceral bypasses were made (156 retrograde; three anterograde).

Results: Thirty-day mortality was 12.7% (n=7). Potential graft-related complications included four cases of pancreatitis (7.3%) and five of peri-operative renal failure (9.1%). At a mean follow-up of 36.1 months, the global rate of visceral graft occlusion was 9.4% (15/159), leading to fatal bowel infarction in two patients and kidney loss in seven patients. Actuarial primary patency in renovisceral grafts at 12, 24, and 36 months was 96.3%, 92.6%, and 90.2% respectively. At the level of the anastomosis of the graft to the superior mesenteric artery, significant flow alterations (systolic peak velocity >250 cm/s) were observed during computed flow dynamics analysis in 18.5% of cases. Overall, an additional procedure to ensure patency was required in 19 bypasses intraoperatively and three during follow-up. The presence of aortic dissection had no significant impact on debranching graft-related complications. During multivariate analysis, retropancreatic routing to CT was the only independent predictor of graft-related complications (P=0.006).

Conclusions: Specific visceral graft-related complications were not uncommon in our series and were often associated with clinical consequences. Hemodynamic alterations of debranching grafts were observed in particular at the level of the anastomosis with the superior mesenteric artery. Careful follow-up is mandatory in order to monitor visceral bypasses and facilitate patency when required.

Keywords: Thoracoabdominal aortic aneurysm (TAAA); hybrid repair (HR); stent; visceral bypass.

Figure 1

Intraoperative control angiography showing anastomotic stenosis of the graft to the superior mesenteric artery due to excessive angulation. The stenosis was immediately treated with stenting.

Figure 2

Multiplanar reconstruction and axial image of Positron Emission Tomography of a patient who underwent TAAA hybrid repair 1 year earlier. The infection likely originated from the right groin and then spread to the abdomen and visceral grafts through a prosthetic conduit that had been used for endograft insertion. The case was managed by means of surgical drainage and omentoplasty. TAAA, thoracoabdominal aortic aneurysm.

Figure 3

Detail and postoperative CT angiography showing the trifurcated graft used for retrograde revascularization of CT, SMA and RRA in a patient with TAAA, solitary functioning right kidney and previous aorto-biiliac bypass. The left branch of the existing graft was the inflow site. This particular configuration may improve the angle of the graft to SMA. CT, celiac trunk; SMA, superior mesenteric artery; RRA, right renal artery; TAAA, thoracoabdominal aortic aneurysm.