Colonic anastomotic healing and oxygen tension.

Using a Clark oxygen electrode and a 133Xe clearance technique, tissue oxygen tension (T02) and blood flow have been determined in the small and large bowel of a rabbit experimental model. The predictive value of perianastomotic T02 in colonic anastomoses was determined, healing being assessed by leakage rate, tensile strength and hydroxyproline content. The effect of suture technique on colonic perianastomotic T02 has also been studied. Colonic and small intestinal T02 correlated with blood flow (r = 0.93). Basal colonic blood flow and oxygen tension were significantly lower than in the small intestine (P less than 0.01). Interrupted and continuous suture techniques decreased colonic perianastomotic T02, although mean T02 in the continuous group was significantly lower than in the interrupted group (P less than 0.01). The leakage rate was 10 per cent (1/10) for anastomoses constructed with a perianastomotic T02 above 55 mmHg compared with 100 per cent (10/10) if less than 25 mmHg (P less than 0.001). Perianastomotic T02 correlated with breaking energy (P less than 0.001), breaking strength (P less than 0.01) and hydroxyproline content (P less than 0.05).