Experimental study of a novel mechanical connector for sutureless open arterial anastomosis

Abstract

Objectives: This study assessed the feasibility and efficacy of a new sutureless connector for end-to-end arterial anastomosis.

Methods: The anastomotic device is a connector consisting of a bare-metal stent with spikes covering its outer surface, which is introduced through the prosthesis. The seal of the anastomosis is obtained by inflating a balloon anchoring the stent with the spikes in the prosthesis and in the receiving artery. This experiment was conducted in three phases: (1) A feasibility study was done on four cadaveric femoral arteries using a polytetrafluoroethylene prosthesis, with measurement of the penetration of the spikes into the layers of the arterial wall. (2) Bench tests were conducted in seven automated and in seven sutured anastomoses. Anastomosis sealing was tested using a pump system (≤250 mm Hg) in a water-filled closed circuit. (3) The infrarenal aorta of seven pigs was replaced with a 6- to 8-mm diameter prosthesis, using this automated device for the proximal anastomosis. The distal anastomosis was handsewn on the aortic bifurcation. After completion angiography, animals were euthanized for macroscopic and histologic studies of the aorta, connector, and prosthesis. Explantations were done immediately (2 pigs), and at 15 (2 pigs), at 30 (2 pigs), and 42 days (1 pig). Study end points were the automated anastomosis time compared with manual suturing, leakage, mechanical strength, and patency of the anastomosis together with the histologic changes of the aortic wall in contact with the spiked stent.

Results: Tests performed on four cadaveric arteries showed complete penetration of the spikes into the arterial wall layers without metal fracture. Tests of traction showed that the median force needed to rupture the automated anastomosis was 18.3 N (interquartile range [IQR], 17.7-19.9 N), with no significant difference from the handmade anastomosis (19.5 N; IQR, 17.9-20.2 N, P = .33). No leakage was demonstrated in vitro with a pulsatile flow and a pressure up to 250 mm Hg. The median automated anastomosis time on pig aorta was 2.4 minutes (IQR, 1.4-3.3 min) vs 17.0 minutes (IQR, 15.1-17.2 minutes) for the handmade aortic anastomosis performed on the same animals (P = .002). There was no anastomotic leak. Histology showed incorporation of the connector spikes in the aortic wall, without intimal hyperplasia or false aneurysm.

Conclusions: This preliminary study confirms the feasibility of this sutureless system, suggesting its usefulness for a faster and simpler anastomosis in hybrid arterial surgery.