Effects of preoperative pelvic irradiation on colonic anastomosis healing. An experimental study in rats.
OBJECTIVE
Colorectal anastomosis is a constant worry-issue among surgeons because of high rates of complications, specially the dehiscence. The preoperative irradiation on cancer surgeries might interfere in the healing process, leading to an unfavorable outcome.


METHODS
In the present study, two groups of rats were irradiated previously to a colorectal anastomosis surgery, with intervals of 4 and 8 weeks between the procedures. Seven days after the surgery, healing process was evaluated for dehiscence presence and histologic inflammatory characteristics. Also, levels of hydroxyproline, metalloproteinases and vascular endothelial growth factor were measured.


RESULTS
Our results showed a higher incidence of dehiscences on the animals submitted to irradiation, compared to controls, with a reduced inflammatory activity in the healing tissue.


CONCLUSIONS
Comparing both irradiated groups, those irradiated 8 weeks before surgery showed higher levels of hydroxyproline and metalloproteinases, indicating higher efficiency of the healing process. In conclusion, preoperative irradiation interferes with intestinal anastomosis healing and a larger time interval between both procedures is safer in terms of the healing quality.
Division of Coloproctology, Department of Surgery and Anatomy, Ribeirão Preto Faculty of Medicine, University of São Paulo, SP, Brazil.
Alexandre
A
Franca
Fernando Silva
FS
Ramalho
Leandra Naira Zambelli
LN
Ramalho
José Joaquim Ribeiro
JJ
da Rocha
Omar
O
Féres
D000714:Anastomosis, Surgical; D000818:Animals; D003094:Collagen / Q000528:radiation effects; D003106:Colon / Q000601:surgery*; D004195:Disease Models, Animal; D006909:Hydroxyproline / Q000032:analysis / Q000528:radiation effects; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000032:analysis / Q000528:radiation effects; D010388:Pelvis; D011300:Preoperative Care / Q000379:methods*; D011879:Radiotherapy Dosage; D051381:Rats; D017208:Rats, Wistar; D012007:Rectum / Q000601:surgery*; D013529:Surgical Wound Dehiscence / Q000209:etiology*; D013997:Time Factors; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis / Q000528:radiation effects; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000528:radiation effects; D014945:Wound Healing / Q000528:radiation effects*
D019715:Tissue Inhibitor of Metalloproteinase-1; D042461:Vascular Endothelial Growth Factor A; D003094:Collagen; D020781:Matrix Metalloproteinase 1; D006909:Hydroxyproline