P. Blomquist

Effect of diverting colostomy on breaking strength of anastomoses after resection of the left side of the colon: studies in the rat

In the present investigation, the effect of a proximal diverting colostomy on suture holding capacity and on anastomotic strength of the excluded left colon was studied. Suture holding capacity was increased 7 days after fecal diversion. Anastomotic strength development, however, was significantly delayed. These differences were accompanied by a diminished collagen response in the anastomotic region after fecal diversion. This might suggest impairment of healing in the excluded colon. The gross appearance of the anastomoses would, however, indicate that increased collagen formation and greater strength development in animals without colostomy is a result of more complicated healing.

Effect of diverting colostomy on collagen metabolism in the colonic wall: Studies in the rat*

The effect of total bowel rest by colostomy on collagen metabolism was studied. Fecal diversion led to a marked decrease of collagen and protein synthesis in the excluded colon. These changes were accompanied by a decrease in the amount of collagen and noncollagenous components. In the colonic part proximal to the colostomy site, a less marked decrease in collagen content was observed. It was concluded that stimulation of intraluminal bulk might be important as a regulating factor for collagen turnover. It remains to be determined if the observed changes in collagen metabolism affect colonic healing.

Impact of long-term relative bowel rest on conditions for colonic surgery

Collagen content, bursting wall tension, and suture-holding capacity in the proximal and distal colon of the rat were studied after long-term treatment with a low-residue or a standard laboratory chow diet. Collagen content decreased uniformly in both the proximal and distal colon of the low-residue diet group. In addition, the bursting wall tension of the nonoperated proximal colon was reduced, whereas the breaking strength of a newly constructed anastomosis at three different colonic sites was unaffected.

Influence of long-term relative bowel rest on the healing of a left colon anastomosis

The influence of long-term relative bowel rest, using a low residue diet, on healing of a left colon anastomosis was experimentally studied. Retarded and diminished gain of postoperative anastomotic collagen and strength was found. The healing of the anastomosis was uncomplicated, however, and it is concluded that anastomotic integrity after surgery in this condition is safe.

The effect of relative bowel rest on collagen in the colonic wall. Studies in the rat

SummaryIn previous studies it was shown that diminished colonic content pre- and postoperatively, obtained by feeding rats low residue diet, results in less marked postoperative disturbances in collagen metabolism than in animals fed standard laboratory diet.In the present investigation the effect of relative bowel rest on collagen content and collagen concentration in the intact colonic wall was studied by feeding unoperated rats low residue diet. It was found that the colonic and cecal contents were reduced significantly and that this primarily affected the non-collagenous substances in the colon with a marked decrease, while the collagen content was unchanged. In the cecum, both the collagen and the non-collagenous contents were significantly increased. Thus, the pattern of change in biochemical response varied in different parts of the large intestine after institution of bowel rest. Further, the present data imply that collagen concentration can be misleading as a measure of the actual collagen amount.

The effect of diverting colostomy on anastomotic healing after resection of left colon obstruction

A standardized stenosis of the left colon was created in the rat model. After four days the stenosis was resected and a primary anastomosis made. Half of the animals (n=21) were randomized to a proximal diverting colostomy and the other half to a non-colostomy control group. On postoperative days two and seven anastomotic complications were recorded and anastomotic strength was determined. Collagen content in the anastomotic area was measured. In the colostomy group no anastomotic complications occurred, while 6/21 (29%) animals in the non-colostomy group had complications. On day two there was no difference between the groups as regards anastomotic strength and collagen content. After a week, however, the control group showed a significant increase in both anastomotic strength and collagen content which was not observed in the colostomy group. The absence of increase in anastomotic strength in the colostomy group had no adverse effect on anastomotic healing, as judged by complications. Thus, a diverting colostomy may be of value in reducing anastomotic complications after resection of a left colon obstruction.

The effect of relative bowel rest on collagen metabolism and suture holding capacity in the colonic wall. Studies in the rat.

SummaryIn a previous experimental study it was shown that bowel rest with low residue diet led to a reduction of the non-collagenous substances in the intact, unoperated colon, while the collagen content remained unchanged. In the cecum, both the collagen content and the non-collagenous substances were markedly increased.In the present investigation the effect of relative bowel rest on collagen synthesis in the colonic wall was studied. Further, a possible influence on mechanical properties was evaluated. It was found out that bowel rest led to a marked decrease of collagen and protein synthesis in the colon. In the cecum, there was an unchanged collagen synthesis but an increased protein synthesis. It can be deduced that lysis of collagen is decreased in all parts of the colon. The depression of collagen turnover in the colonic wall was not accompanied by measurable changes in mechanical strength. It remains to be studied whether the observed changes in collagen metabolism do affect colonic healing.

Effects of Different Suture Techniques on Healing of Experimental Colonic Anastomosis

Anastomotic leakage and dehiscence after gastro-intestinal surgery endanger the life of the patient. The incidence of anastomotic complications is especially high after surgery on the left colon; anastomotic leaks are reported to occur in 2%–7% of colonic anastomoses in general [1–3], and in up to 25% after anterior resections [1, 4]. Goligher et al. [5], using early postoperative contrast enemas, reported an incidence of anastomotic leakage after anterior resections of over 50%. However, most of these leaks were subclinical.

Healing of a left colon anastomosis after early colostomy closure: An experimental study in the rat

The healing of a standardized left colon anastomosis after early (7 days) closure of a concomitant proximal diverting colostomy was studied experimentally. Early closure of the diverting colostomy could be conducted safely by an intraperitoneal technique and the healing of the primary anastomosis was uncomplicated. Colostomy closure in the proliferative phase of wound healing resulted in development of anastomotic strength similar to colonic healing without faecal diversion. The anastomotic strength had doubled after three weeks. As compared to colostomy closure in the remodelling phase of anastomotic healing development of anastomotic strength was more rapid and without serious local complications.