In vitro bursting strength studies of laser-welded tissue and comparison with conventional anastomosis

Abstract

We compared the mechanical integrity of microvascular anastomoses created with a carbon dioxide (CO2) laser with conventional suture anastomoses. Seventy rat femoral artery segments (35 lased and 35 sutured) were harvested at 1, 24, and 72 hours, and 1, 3, 6, and 12 weeks postoperatively. These segments were subjected to increasingly higher in vitro intraluminal hydrostatic pressures (bursting pressure). Conventionally sutured anastomoses exhibited significantly increased ability (p less than 0.05) to withstand greater bursting pressures than the laser-welded tissue up to 3 weeks postoperatively. After the third postoperative week, the laser anastomoses demonstrated increased bursting pressures compared with the conventional anastomoses. At the end of the 12-week period both groups demonstrated an ability to withstand supraphysiologic pressures in excess of 2000 mm Hg.

Suture-free laser-assisted vessel repair using CO2 laser and liquid albumin solder

“…The leaking point pressure ͑LPP͒ was measured directly after laser irradiation ͑two passes: n =15; three passes: n =5͒ in accordance with the method of Basu et al 18 and Fahner et al 19 One end of the laser-treated carotid segment was sealed by ligation and the vessel lumen filled with methylene blue dye ͑Sigma-Aldrich͒. The other end was ligated around a blunt 25G needle that was connected to a rate-controlled syringe infusion pump and a pressure controller ͑Braun Medical, Melsungen, Germany͒ through an interposed T-valve.…”

A comparison by burst testing of three types of vascular anastomosis

“…The major concern with laser techniques is the strength of the repair and its ability to avoid dehiscence and aneurysm formation. 15 We used our new technique 10 for in vivo burst testing to determine the relative strengths of a conventional laser technique versus a conventional suture and conventional telescopic technique. Our data demonstrate that the laser technique is modestly weaker than the other techniques at each stage of healing.…”

Sutureless Laser-Welded Anastomosis of the Femoral Artery and Vein in Rats Using CO2and Nd: YAG Lasers

“…Laser-welding for vascular anastomosis has been applied and investigated by a number of authors. 2 -47 - 9 The majority used 3 to 4 stay sutures to adapt to the vessel walls. 4 -' 01314 Others inserted an absorbable stent for precise endothelial apposition.…”

“…34 Studies of tensile and bursting strength have shown that LAMA can consistently withstand supra-physiologic pressures, although there is a marked weakness in bursting and tensile strength at three days postoperatively. 5 - 9 Laser welding seems to be especially advantageous in traumatized blood vessels, probably due to a reduction of foreign-body reaction, because fewer sutures are needed for LAMA. 10 Completely laser-welded anastomoses would thus be desirable, as they promise the greatest saving in time, the easiest operative performance, and no foreign-body reaction.…”