Results from multiple prospective single-center clinical trials of the off-the-shelf p-Branch fenestrated stent graft

OBJECTIVE: The purpose of this study was to report prospective data of an off-the-shelf fenestrated endograft (Zenith p-Branch; Cook Medical, Bloomington, Ind) from four centers for the treatment of patients with pararenal abdominal aortic aneurysms.

METHODS: Data were combined from four single-center investigational studies conducted in the United States and Europe. The p-Branch endograft consists of a proximal off-the-shelf component incorporating a scallop for the celiac artery, a superior mesenteric artery fenestration, and two conical pivot fenestrations to preserve flow to the renal vessels. The device is available in two configurations, a left renal fenestration at the same (configuration A) or lower (configuration B) longitudinal position than the right to accommodate varied anatomy of the patients.

RESULTS: Between August 2011 and September 2015, 76 patients (82% male; mean age, 72 years; 65 elective and 11 emergent) were enrolled, with 55% implanted with option A and 45% with B. The device was deployed successfully in all patients, and stents were placed in all target vessels except in three cases (one elective, two emergent): a left kidney was sacrificed in one patient, and a right renal artery was left unstented in two patients during the index procedure. There was no 30-day mortality. During follow-up (mean, 25 ± 13 months), 10 late deaths occurred (6 elective, 4 emergent; none related to device or procedure), and there were no ruptures or conversions to open repair. Two patients experienced bowel ischemia; one case resolved with nonoperative treatment and one required superior mesenteric artery and celiac artery angioplasty and stent placement. Renal artery occlusion occurred in eight patients (11%) and was deemed procedure related in 63% (5/8) of these patients. Four of these were successfully intervened on with preservation of renal function. The overall renal insufficiency incidence was 7% (5/76). One patient developed renal failure requiring dialysis.

CONCLUSIONS: Early results incorporating learning curves for physicians with a new device and delivery system indicate that the use of the Zenith p-Branch device is feasible and safe. Long-term follow-up is needed to assess the effectiveness and durability of this treatment strategy and to refine the indications for use.