1078 Methods outcomes including survival of consecutive patients who un- derwent laparoscopic resection for colorectal malignancy in a high volume tertiary center. Comparison of the outcomes with those patients who underwent open resection performed during the same period of time was performed. Laparoscopic resection has become widely applied in the authors’ department since 2000. During the study period from 2000 to 2009, the choice of surgical approach was decided mainly by the surgeons’ experience and patients’ preference with all the risk of both approaches discussed with the patients. Since 2008, when the senior author was in charge of the Division of Colorectal Surgery, laparoscopic resection was offered to all suitable patients who planned to have elective surgery for colorectal cancer unless contraindicated. The operation techniques of laparoscopic surgery were described in the previous publications. A standardized me- dial to lateral approach was adopted from 2004 [14]. The majority of patients underwent laparoscopic assisted resec- tion with three to five ports and the retrieval of the specimen was performed through an abdominal incision. In those patients who underwent laparoscopic abdominoperineal re- section or low anterior resection with coloanal anastomosis, the specimen would be retrieved through the perineum or anus. Transvaginal retrieval of the specimen was performed in selected female patients who underwent commitment hysterectomy. From 2008, some selected patients were op- erated on with robotic-assisted resection or single incision laparoscopic surgery [15]. During the study period, the patients who underwent laparoscopic or open resection had similar preoperative workup and preparation for surgery. The postoperative man- agement and the policies of adjuvant therapy were similar in all the patients, regardless of the surgical approach. All the operations were performed or supervised by spe- cialists in the Division of Colorectal Surgery. In the early period, two staff surgeons performed or supervised the majority of laparoscopic operations and they also performed the open operations. From 2004, with the departure of one laparoscopic surgeon, the senior surgeon supervised and performed the majority of the laparoscopic resection until the other staff members were trained to perform laparoscop- ic colectomy in a standardized technique. All the laparo- scopic rectal resections are still performed or under the supervision by the senior author. Definition Operative mortality was defined as deaths that occurred within 30 days following the primary operation. Operative Int J Colorectal Dis (2012) 27:1077–1085 morbidities were defined as complications that contributed to prolonged hospital stay or led to additional interventions or procedures. Conversion was defined as the need for prematurely making the abdominal incision for bowel mobilization and/or vascular control. The necessity for an abdominal incision to deal with any intra-operative complication was also considered conversion. Data collection and statistical analysis Data on the patients’ demographics, medical comorbidities, locations of the tumors, operative details, postoperative out- comes, and follow-up status were collected prospectively and entered into a database for colorectal malignancy. In the comparison of data on patients with laparoscopic and open resection, the analysis was performed according to the in- tention to treat principle. Patients with conversion were analyzed in the laparoscopic resection group. Comparison of the categorical or ordinal variables was performed using chi-square test or Fisher’s exact test where appropriate. Continuous variables were presented in median values and interquartile ranges. Comparison was performed using Mann–Whitney U test. Survival analysis was per- formed after excluding patients who died within 30 days after the surgery and who had stage IV disease. Survival was analyzed using Kaplan–Meier method and comparison of variables was performed with log rank test. Multivariate anal- ysis was performed with Cox regression using variables found to be statistically significant in univariate analysis. p values of less than 0.05 were regarded statistically significant. Results After excluding those patients who underwent emergency surgery, operations without resection and local excision of rectal cancer, 2,011 patients were included in the current study. They underwent laparoscopic or open radical resection for adenocarcinoma of colon or rectum. There were 1,157 men (57.5%) and the median age was 71 years (range, 22– 96 years). In 911 patients (45.3%), the tumors were located at the rectum or rectosigmoid. All operations were performed on an elective setting and patients with emergency operations were excluded. Thirty-nine patients, who had obstructing left-sided colorectal cancer, were included. Twenty-seven had metallic stent insertion prior to resection and 12 had prior colostomy for rectal cancer so that resection can be performed on an elective setting, usually after neoadjuvant therapy. The operative mortality and morbidity rates of all the patients were 1.3% and 23.7%, respectively. Laparoscopic resection was performed in 814 patients (40.5%). In those patients with laparoscopic resection, 58 required conversion