Multilayered Human Skeletal Muscle Myoblast Sheets Promote the Healing Process After Colonic Anastomosis in Rats

Colorectal anastomotic leakage is one of the most feared and fatal complications of colorectal surgery. To date, no external coating material that can prevent anastomotic leakage has been developed. As myoblasts possess anti-inflammatory capacity and improve wound healing, we developed a multilayered human skeletal muscle myoblast (HSMM) sheet by periodic exposure to supraphysiological hydrostatic pressure during repeated cell seeding. We assessed whether the application of an HSMM sheet can promote the healing process after colonic anastomosis. Partial colectomy and insufficient suturing were employed to create a high-risk colo-colonic anastomosis model in 60 nude rats. Rats were divided into a control group ( n = 30) and an HSMM sheet group ( n = 30). Macroscopic findings, anastomotic bursting pressure, and histology at the colonic anastomotic site were evaluated on postoperative day (POD) 3, 5, 7, 14, and 28. The application of an HSMM sheet significantly suppressed abscess formation at the anastomotic site compared to the control group on POD3 and 5. The anastomotic bursting pressure in the HSMM sheet group was higher than that in the control group on POD3 and 5. Inflammatory cell infiltration in the HSMM sheet group was significantly suppressed compared to that in the control group throughout the time course. Collagen deposition in the HSMM sheet group on POD3 was significantly abundant compared to that in the control group. Regeneration of the mucosa at the colonic anastomotic site was promoted in the HSMM sheet group compared to that in the control group on POD14 and 28. Immunohistochemical analysis demonstrated that surviving cells in the HSMM sheet gradually decreased with postoperative time and none were detected on POD14. These results suggest that the application of a multilayered HSMM sheet may prevent postoperative colonic anastomotic leakage.

Influence of Early Postoperative Feeding in Gastrointestinal Anastomotic Fistula Formation and Healing Time in Rabbits

Objectives. To determine whether early postoperative feeding attenuates the inhibitory effects of intestinal anastomosis in rabbits. Methods. After undergoing gastrointestinal anastomosis, 48 rabbits were randomly divided into experimental and control groups. The rabbits in the experimental group were fed a liquid diet beginning 24 h postoperatively, while the control rabbits received only total parenteral nutrition after the operation. Exploratory laparotomies were performed on four rabbits in each group 3, 5, 7, 10, and 15 days postoperatively, and the healing rate of the anastomosis, anastomotic bursting pressure, anastomotic breaking strength, and hydroxyproline content at the anastomosis were determined. Results. The anastomoses healed in 91.6% (22/24) of the control group and 95.8% (23/24) of the experimental group. The anastomotic bursting pressure decreased remarkably in both groups 3 days postoperatively, reaching the lowest value. The anastomotic breaking strength did not differ between the two groups 3 days postoperatively, when both reached their lowest points, and both groups increased markedly and peaked 10 days postoperatively. The hydroxyproline content of the anastomosis was slightly lower in the experimental group 3 days postoperatively, although both groups peaked 7 days postoperatively. Conclusions. Early postoperative feeding does not increase the anastomosis healing time or rate of gastrointestinal anastomosis leakage.

Chemotherapy and the Healing Process.

The increasing use of chemotherapy in association with surgery has prompted the suggestion that cancer chemotherapeutic drugs may interfere with the healing process. To test this hypothesis 30 Wistar rats were subjected to laparotomy and colonic resection and treated with 5-Fluorouracil or Mitomycin C. The bursting strength of the abdominal scars and the colonic anastomotic bursting pressure revealed some interference in the rats treated with 5-Fluorouracil (Student's t test P < 0.05) but none in the case of Mitomycin C. This preliminary study deserves to be followed up.