Bipolar radio-frequency-induced thermofusion of intestinal tissue - In vivo evaluation of a new fusion technique in an experimental study.

PURPOSE: Bipolar radio-frequency-induced thermofusion (BiRTh) of intestinal tissue might replace conventional stapling devices which are associated with technical and functional complications. Previous results of our study group confirmed the feasibility to fuse intestinal tissue using BiRTh-induced thermofusion ex vivo. The aim of this study was now to evaluate the efficacy of fusing intestinal tissue in vivo by BiRTh-induced thermofusion. MATERIALS AND METHODS: In male Wistar rats a blind bowel originating from the caecum was closed either by BiRTh (n = 24) or conventional suture (n = 16). At 6 h, 48 h, 4 days, and 2 weeks after the procedure caecum bursting pressure was measured to compare both groups. RESULTS: In total 18 of 21 (85.7%) thermofused and 15 of 16 (93.7%) sutured cecal stumps were primarily tight and leakage-proof (p > 0.05). The operative time was comparable in both groups without significant differences. Both groups showed increases in bursting pressure over the post-operative period. The mean bursting pressure for thermofusion was 47.8, 48.3, 55.2, and 68.0 mmHg, compared to 69.8, 51.5, 70.0 and 71.0 mmHg in the hand-sutured group (p > 0.05) after 6 h, 48 h, 4 days, and 2 weeks, respectively. CONCLUSION: These results suggest that BiRTh-induced thermofusion is a safe and feasible method for fusing intestinal tissue in this experimental in vivo model and could be an innovative approach for achieving gastrointestinal anastomoses.

Bipolar radiofrequency-induced thermofusion of intestinal anastomoses--feasibility of a new anastomosis technique in porcine and rat colon.

PURPOSE: In recent years, vessel sealing has become a well-established method in surgical practice for sealing and transecting vessels. Since this technology depends on the fusion of collagen fibers abundantly present in the intestinal wall, it should also be possible to create intestinal anastomoses by thermofusion. Bipolar radiofrequency-induced thermofusion of intestinal tissue may replace traditionally used staples or sutures in the future. The aim of this study was to evaluate the feasibility of fusing intestinal tissue ex vivo by bipolar radiofrequency-induced thermofusion. MATERIALS AND METHODS: An experimental setup for temperature-controlled bipolar radiofrequency-induced thermofusion of porcine (n = 30) and rat (n = 18) intestinal tissue was developed. Colon samples were harvested and then anastomosed, altering compressive pressure to examine its influence on anastomotic bursting pressure during radiofrequency-induced anastomotic fusion. For comparison, mechanical stapler anastomoses of porcine colonic samples and conventional suturing of rat colonic samples identical to those used for fusion experiments were prepared, and burst pressure was measured. RESULTS: All thermofused colonic anastomoses were primarily tight and leakage proof. For porcine colonic samples, an optimal interval of compressive pressure (1,125 mN/mm(2)) with respect to a high amount of burst pressure (41 mmHg) was detected. The mean bursting pressure for mechanical stapler anastomosis was 60.7 mmHg and did not differ from the thermofusion (p = 0.15). Furthermore, the mean bursting pressure for thermofusion of rat colonic samples was up to 69.5 mmHg for a compressive pressure of 140 mN/mm(2). CONCLUSION: These results confirm the feasibility to create experimental intestinal anastomoses using bipolar radiofrequency-induced thermofusion. The stability of the induced thermofusion showed no differences when compared to that of conventional anastomoses. Bipolar radiofrequency-induced thermofusion of intestinal tissue represents an innovative approach for achieving gastrointestinal anastomoses.

Pilot study of bipolar radiofrequency-induced anastomotic thermofusion-exploration of therapy parameters ex vivo.

PURPOSE: Vessel sealing has been well-established in surgical practice in recent years. Bipolar radiofrequency-induced thermofusion (BIRTH) of intestinal tissue might replace traditionally used staples or sutures in the near future. In this experimental study, the influence of compressive pressure, fusion temperature, and duration of heating on the quality of intestinal anastomosis was investigated to obtain the relevant major parameters for the in vivo use of this system. METHODS: An experimental setup for a closed-loop temperature-controlled bipolar radiofrequency-induced thermofusion of porcine intestinal tissue was developed. Twenty-four colon samples were harvested from nine different Saalower-Kräuter pigs and then anastomosed altering compressive pressure on five different levels to explore its influence on anastomotic bursting pressure. RESULTS: The anastomotic bursting strength depends on the compressive pressure applied to the colonic fusion site. An optimal interval of compressive pressure (CP = 1.125 N/mm(2)) in respect of a high amount of burst pressure was detected. A correlation (r = 0.54, p = 0.015) of burst pressure to delta compression indicated that increasing colonic wall thickness probably strengthens the anastomotic fusion. CONCLUSION: This study is a first step to enlighten the major parameters of tissue fusion, though effects and interactions of various main parameters of bipolar radiofrequency-induced thermofusion of colonic tissue remain unclear. Further studies exploring the main effects and interactions of tissue and process parameters to the quality of the fusion site have to follow.