Till Örebro universitet

Every year inn Sweden more than 6000 individuals are diagnosed with colorectal cancer and more than 5000 operations are performed. Anastomotic leakage (AL) is the most dreaded complication in colorectal surgery and has a great impact on postoperative morbidity and mortality. 

In Study I, an iatrogenic rectal perforation was performed on an experimental group of pigs, in order to imitate AL and compared with a control group which had a sham operation over a 10-hours follow-up with intraperitoneal microdialysis (IPM) and cytokines. Glucose levels were lower in the experimental group at 4 hours and lactate and lactate/pyruvate ratios (L/P) were higher in the experimental group at 7 hours. Intraperitoneal (IP) Interleukine 6 (IL6) and Interleukine 10 (IL10) were higher in the experimental group at 10 hours and blood IL6 was higher in the experimental group at 4 hours. IPM and cytokines thus seem to react early after rectal perforation. 

Study II was a prospective observational study in which 7 patients with AL after surgery were compared with 13 patients without complications during the first 7 postoperative days with IPM, and intravenous and IP cytokines. In patients who later developed AL, IP lactate and L/P were higher immediately after surgery, while glycerol levels were lower. At the anastomosis higher L/P in AL patients were found after the fifth postoperative day. Intravenous and IP IL6 was higher in the leakage group. 

In Study III, mRNA expression in blood was analyzed in an animal model designed to imitate AL. Significantly increased levels of 276 genes were found and 11 of the 48 genes which coded for a known protein were highly up-regulated.

In Study IV, the metabolic effects of a fully covered self-expandable metal stent (FCSEMS) over a colorectal anastomosis were investigated with IPM, after laparotomy, colon resection and anastomosis with stent. Lactate and L/P rise at the oral part of the anastomosis were significantly higher, while glucose showed a small tendency toward numerically declining values. At the distal part of the anastomosis glucose decreased significantly after the resection but did not reach zero. Lactate increased significantly while L/P slightly increased. This suggest that hypermetabolism occurs in the intestinal ends next to the resectate, but even a start of hypoxemia cannot be excluded after the placement of a FCSEMS.