Note: Only the anastomosis-relevant complications are listed here!
Anastomotic insufficiency
Common causes of suture insufficiency are: Not sparing skeletonization of the intestinal wall (perfusion disorder), sutures under tension (dehiscence) as well as intramural hematomas. Irradiations, perfusion disorders, steroid and cytostatic therapy, catabolism and shock states represent further risk factors for the intestinal suture.
Inadequate physiological fibrin adhesion, infections and anatomical or microbial peculiarities also favor anastomotic insufficiencies. For extraluminal additional securing of the intestinal suture, covering with peritoneum and omentum, with resorbable material such as e.g. PGS mesh and coating the anastomosis with fibrin glue are options.
Infections and perfusion disorders are, according to clinical experience and animal experimental studies, the most essential causes of insufficiency of anastomoses. The infection-induced collagenase with increased collagen degradation leads to reduced strength of the anastomosis. A leakage can, if the intestinal contents enter the free abdominal cavity, lead to a life-threatening peritonitis. If the insufficiency is covered, an abscess develops, which can develop into an intestinal fistula.
Abscess
Detritus, hematomas, foreign bodies and the accumulation of lymph as well as their bacterial contamination are the starting point of the perianastomotic abscess with risk of perforation. Deep colorectal or coloanal anastomoses are particularly endangered by such infections. The presence of feces favors the infection and thus the insufficiency and its consequences.
Animal experimental and clinical statements report that lowered protein or plasma albumin and a significant preoperative weight loss (tumor cachexia!) represent risk factors for anastomotic healing.
Stenosis
Intestinal anastomoses tend to shrink.
Especially rectal anastomoses, which are excluded from stool passage by a colostomy, stenose more frequently. A stenosis is apparently prevented by the bougie effect of the stool passage.
Wound infection
Here too, the incidence depends on various factors. The most important are: low immune defense of the patient (tumor cachexia, diabetes mellitus etc), emergency surgery with high probability of contamination, interventions on the large intestine.