Enterotomy Fusion with Laser Energy: Preliminary Results in Rabbit Ileum

Abstract

The utility of enterotomy closure with the argon and CO₂ lasers was examined in New Zealand white rabbit ileum. Thermal properties of 10 argon (0.5 W power for 30 s, energy fluence 230 J/cm²) and 10 CO₂ (1.0 W power for 30 s, energy fluence 2700 J/cm²) laser-fused enterotomies were determined during acute fusion experiments using an AGA 782 digital thermographic camera. Healing of the fusions created by the two lasers was subsequently assessed in an additional group of 28 rabbits by comparing three 1.0-cm longitudinal ileal enterotomies, with each rabbit having both types of laser-welded closures and a sutured control. Thermal measurements made from the 10 closures with each laser revealed that the CO₂ fusions generated significantly higher temperatures (max. 198°C, mean 106 ± 37°C, n = 100) than argon (max. 85.2°C, mean 60.5 ± 8.1°'C, n = 100) p < 0.001. In the healing studies, four rabbits died from weld failures (one argon and one CO₂ disruption, two rabbits with both welds disrupted). Two additional rabbits died at I day and one at 10 days for undetermined reasons. The remainder of the animals were sacrificed at I (n = II), 2 (n = 2) and 4 (n = 9) weeks postoperatively. Sutured closures exhibited more granulation tissue and adhesions surrounding the wounds than did welded closures and seven microabscesses were noted adjacent to sutured repairs. One of the CO₂ repairs had an abscess at 4 weeks and none of the argon laser fusions had evidence of disruption or abscess. Histologic examination of both sutured and laser-welded enterotomies demonstrated active healing at I week with minimal collagen bridging the anastomoses. At 2 and 4 weeks, there was marked granulomatous reaction around the sutures, while laser-welded enterotomies had minimal inflammatory response. There was no observed effect of the difference in thermal properties of the CO₂ and argon fusions on long-term healing. These findings suggest laser welding of small bowel enterotomies presents an alternative to convential suture closure, and advantages may include decreased formation of adhesions and less foreign body reaction at the fusion line in laser repairs.

Key Words:

• Enterotomy
• laser tissue welding
• tissue fusion
• thermal camera