Int J Colorectal Dis (2004) 19:250–257 DOI 10.1007/s00384-003-0533-9 Accepted: 21 July 2003 Published online: 24 September 2003 © Springer-Verlag 2003 Abstract Background and aims: Anastomotic dehiscence following colorectal surgery is a significant cause of morbidity and mortality. Phenytoin has wound-healing pro- moting and collagenase inhibitory effects. This study assessed these ef- fects on healing of experimental co- lonic anastomoses in a rat model. Materials and methods: Ninety Wis- tar rats weighing 240–290 g were di- vided into six groups: 3rd-day con- trol group (n=15), 3rd-day oral ad- ministration of phenytoin (n=15), 3rd-day rectal administration of phe- nytoin (n=15), 7th-day control group (n=15), 7th-day oral administration of phenytoin (n=15), and 7th-day rectal administration of phenytoin (n=15). In oral phenytoin groups the agent was given at 10 mg/kg daily per orogastric route by 4-F fine feed- ing catheter; in rectal phenytoin RAP groups the agent was administered at 10 mg/0.5 cc daily to the anastomos- es transrectally via a fine anal cathe- ter. Results: There were significantly higher anastomosis bursting pressure values and hydroxyproline contents in phenytoin groups than in controls. In histopathological examination it was seen that phenytoin treatment caused greater collagen deposition, fibroblast, and blood vessel ingrowth than in controls. Immunohistochemi- cal analysis showed the stimulatory effect of phenytoin in expression of vascular endothelial growth factor and basic fibroblast growth factor. Anastomosis bursting pressure, his- topathological analysis, hydroxypro- line content, and immunohistochemi- cal results were better in the groups with rectal administration than in those with oral administration. Con- clusion: These results had showed us that phenytoin administration result- ed in enhanced stability of colonic anastomoses during the first postop- erative week and rectal administra- tion showed better results than oral administration. Keywords Colon anastomosis · Phenytoin · Vascular endothelial growth factor · Basic fibroblast growth factor ORIGINAL ARTICLE Mustafa Turan Serpil Unver Saraydin Emel Canbay Kursat Karadayi Eray Bulut Öge Cetinkaya S ¸ ahande Elagöz Metin S ¸en Positive effects of phenytoin on experimental colonic anastomoses Introduction Anastomotic dehiscence following colorectal surgery is a significant cause of morbidity and mortality [1, 2]. The rate of clinically apparent anastomotic leakage ranges from 3.4% to 8% [1, 3]. At least one-third of deaths fol- lowing colorectal surgery are attributed to anastomotic leakage [1, 3]. Despite the progress made to this day anastomotic dehiscence following colonic anastomosis is a serious clinical complication. It has been reported that approximately 40–50% of patients treated by phenytoin, an anticonvulsant, develop esthetically disfiguring en- largement of gingivae [4, 5]. Phenytoin may also signifi- cantly promote wound healing following topical applica- M. Turan ( ✉ ) · E. Canbay · K. Karadayi M. S ¸en Department of General Surgery, Faculty of Medicine, Cumhuriyet University, 58140 Sivas, Turkey e-mail: mturan_1999@yahoo.com Tel.: +90-346-2250434 Fax: +90-346-2262162 M. Turan Gokcebostan Mah. 2. Sok. Hurriyet Apt. Daire No 2, 58050 Sivas, Turkey S. Unver Saraydin · E. Bulut Department of Histology, Faculty of Medicine, Cumhuriyet University, 58140 Sivas, Turkey Ö. Cetinkaya Department of Biochemistry, Faculty of Medicine, Cumhuriyet University, 58140 Sivas, Turkey S ¸. Elagöz Department of Pathology, Faculty of Medicine, Cumhuriyet University, 58140 Sivas, Turkey