Effect of irradiation on healing of newly made colonic anastomoses in the rat.
OBJECTIVE
Short-term effects of radiotherapy on the healing process of newly made colonic anastomoses are investigated by measuring the anastomotic strength in a rat model.


METHODS
Four groups of Wistar rats were used. In all groups, rats underwent a 1 cm sigmoid resection with end-to-end anastomosis. Group I served as a control group. In group II the anastomosis was irradiated after closure of the abdominal wall with a single dose of 20 Gy of 250 kV x rays. Group III was irradiated with a single dose of 20 Gy while the abdominal wall was not closed, and the surrounding tissues were carefully covered by a lead plate, simulating intra-operative radiotherapy. Group IV was treated as group III, but a larger dose of 25 Gy was applied. Animals were sacrificed 3 or 7 days after the operation. General condition of the rats was determined by observation, weight loss, serum protein and albumin at sacrifice. Anastomotic healing was evaluated by inspection, bursting pressure, hydroxyproline and protein contents of the anastomotic segment.


RESULTS
Direct postoperative externally irradiated rats (group II) showed a marked weight loss, hypoproteinaemia and hypo-albuminaemia because of involvement of small bowel in the irradiated volume. With respect to anastomotic healing there were no significant differences between control and irradiated groups.


CONCLUSIONS
These data suggest that the application of a single dose of irradiation (20 and 25 Gy) on colonic anastomoses given in a direct postoperative or intraoperative model has no measurable side effect on the early healing of newly made colonic anastomoses. Direct postoperative external irradiation results in unwanted side effects in the adjacent bowel.
Biert
J
J
Department of General Surgery, University Hospital, Nijmegen, The Netherlands.
Wobbes
T
T
Hendriks
T
T
Hoogenhout
J
J
D000714:Anastomosis, Surgical; D000818:Animals; D001798:Blood Proteins / Q000032:analysis; D001835:Body Weight / Q000528:radiation effects; D003106:Colon / Q000528:radiation effects / Q000601:surgery*; D012809:Colon, Sigmoid / Q000528:radiation effects / Q000601:surgery*; D004307:Dose-Response Relationship, Radiation; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012709:Serum Albumin / Q000032:analysis; D014945:Wound Healing / Q000528:radiation effects*
D001798:Blood Proteins; D012709:Serum Albumin