Surg Today (2009) 39:38–43 DOI 10.1007/s00595-008-3795-6 Reprint requests to: E. Ersoy Received: March 10, 2008 / Accepted: April 1, 2008 Effects of Oxaliplatin and 5-Fluorouracil on the Healing of Colon Anastomoses EREN ERSOY 1 , HAKAN AKBULUT 2 , and GÖKHAN MORAY 3 1 Department of General Surgery, Ankara Atatürk Research and Education Hospital, Acar Beytepe Evleri No: 154/27, Beytepe, Ankara, Turkey 2 Department of Medical Oncology, University of Ankara Faculty of Medicine, Ankara, Turkey 3 Department of General Surgery, University of Baskent, Faculty of Medicine, Ankara, Turkey Abstract Purpose. Oxaliplatin (OX) and 5-fluorouracil (5-FU) are the most widely used chemotherapeutic agents in the adjuvant treatment of colon cancer. Although the early initiation of adjuvant chemotherapy can improve the outcome of surgery, it carries potentially fatal risks. This experimental study investigates the effects of 5-FU and OX on colon anastomoses. Methods. We used 60 rats, divided into six groups. After being subjected to bowel resection and anastomosis, the rats were given 5-FU on days 1–3, or OX 130 mg/m 2 on days 1 or 5, or 5% dextrose as a control. The bursting pressures and hydroxyproline content of the anastomo- ses were measured, and complications and adhesions were recorded. Results. There were no major complications in the treatment groups. The bursting pressures of the 5-FU group were significantly lower than those of the control and OX groups. The bursting pressures of the OX groups were not significantly different from those of the control groups. The hydroxyproline levels of the rats treated with OX on day 1 were significantly lower than those of the rats treated with OX on day 5 and the 5-FU groups. Conclusion. Oxaliplatin and 5-FU did not compromise wound healing of the colon significantly. Our results indicate that OX is less detrimental to the healing of colonic anastomoses, when administered on days 1 and 5 after resection, than 5-FU. Key words Wound healing · Oxaliplatin · 5- Fluorouracil Introduction Despite improvements in surgical techniques, almost half of all patients with colorectal cancer will eventually die of recurrent disease. However, adjuvant chemother- apy has improved survival rates after curative resection. It is current oncology practice to give patients with stage B2-C and resectable stage D colorectal cancer adjuvant chemotherapy. For more than 10 years, 5-fluorouracil (5-FU) has been the only adjuvant drug given as a single agent. Recently, oxaliplatin (OX) has been given in addition to 5-FU as the new standard choice of adjuvant treatment for colon cancer. In animal models, primary tumor removal increases the proliferation of cells in metastatic foci. Therefore, the interval between tumor removal and the adminis- tration of adjuvant chemotherapy is critical. According to these animal experiments, the most effective reduction of malignant proliferation occurs when the chemotherapeutic agent is administered immediately after tumor removal. 1,2 Likewise, early initiation of adjuvant chemotherapy improves the success rates. 3–5 However, the hazards of the postoperative local and/or systemic adjuvant therapy on anastomotic healing repair in the intestine need to be investigated and delineated. The early phase of anastomotic healing is characterized by a transient loss of strength in the anastomosed segment. Further reduction in wound strength in this period may compromise anastomotic integrity and increase the risk of anastomotic dehis- cence, which is a potentially devastating surgical complication. 6,7 The negative effects of adjuvant therapy on wound healing oblige physicians to withhold the therapy until the wound tissue is strong enough, to prevent complica- tions such as anastomotic leakage. 8,9 On the other hand, to improve the outcome there is still a strong biological rationale for early systemic chemotherapy. Thus, we conducted this experimental study to elucidate the