The laparoscopic colon resection was first introduced in 1991 [1, 2]. The laparoscopic colectomy has been accepted because of smaller wounds, limited ileus, earlier resumption of dietary intake, and shorter hospital stay compared to open surgery [3-6]. Moreover, the laparoscopic colon resection for malignant disease has been accepted since a large-scale multicenter prospective randomized trial reported the oncologic safety of the laparoscopic-assisted colectomy for colon cancer [7-9]. Recently, the Medical Research Council (MRC) CLASSICC (short-term end points of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer) trial confirmed the oncological safety of laparoscopic colon and rectal surgery [10]. Also, the Clinical Outcome of Surgical Therapy Study Group (COST) trial concluded that the laparoscopic approach was an acceptable alternative to open surgery for colon cancer [7]. According to this evidence, the use of the laparoscopic colorectal resection for cancer has been increasing remarkably in Korea [11-15]. Data retrieved from the Health Insurance Review and Assessment service by the Korean Study Group of Laparoscopic Colorectal Cancer Surgery shows that the annual number in Korea increased yearly and reached 13,683 cases in 2008. The rate of laparoscopic surgery out of the total number of operations for the treatment of colon cancer was 27.8% (3,144/11,325) in 2006. It increased to 49.1% (6,715/13,682) in 2008. The rate of laparoscopic surgery for the treatment of rectal cancer was 24.5% (1,098/4,478) in 2006 and increased to 48.1% (2,290/4,763) in 2008 [16]. However, few studies have evaluated the oncologic safety of laparoscopic colon surgery for cancer in Korea even though laparoscopic colorectal surgery is increasing in Korea. Thus, the purpose of the present study is to evaluate the oncologic safety of a laparoscopic right hemicolectomy in Korean patients and to compare the present data to data from previous prospective randomized trials.

This study, which was approved by the Institutional Review Board of Severance Hospital, was designed as a retrospective and a non-comparative study. From June 2006 to December 2008, 430 laparoscopic colorectal resections for cancer were performed at Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea. Of these, 156 patients underwent curative a laparoscopic-assisted right hemicolectomy for colon cancer (adenocarcinoma, stage I, II, III) by two surgeons (NKK, SHB). The exclusion criteria were patients who underwent palliative surgery, had stage IV cancer and underwent surgery for benign disease. These consecutive 156 patients were enrolled in the present study. The clinicopathologic data and oncologic data were collected from the Yonsei Colorectal Cancer Database. Oncologic data were updated again for the present study by using electronic medical charts and telephone interviews. Missing data were evaluated retrospectively again by reviewing the electronic medical charts.

Patient characteristics, American Society of Anesthesiologists (ASA) score [17] and history of previous abdominal surgeries were evaluated. Perioperative clinical outcomes, operative times, bleeding, days to first gas out, days to first soft diet, lengths of stay and readmission rates were evaluated. In the present study, length of stay was recorded as the observed length of stay and possible length of stay. The observed length of stay was the total period from the operation date to the discharge date. The possible length of stay was the hypothetical length of stay according to the discharge criteria. The discharge criteria included tolerance of soft diet and no postoperative complications. In the present study, the possible length of stay was adopted to evaluate the length of stay objectively because many Korean patients want to stay longer in the hospital for no reason.

Postoperative complications were categorized by using the accordion severity-grading system [18]. A mild complication was defined as one that required only a minor invasive procedure that could be done at the bedside, such as insertion of intravenous lines, urinary catheters, and nasogastric tubes, and drainage of wound infections. Physiotherapy and the following drugs were allowed: antiemetics, antipyretics, analgesics, diuretics, electrolytes, and physiotherapy. A moderate complication was defined as one that required pharmacologic treatment with drugs other than what was allowed for minor complications, for instance, antibiotics. Blood transfusions and total parenteral nutrition were also included. A severe complication was defined as all complications requiring endoscopic or interventional radiologic procedures or re-operation, as well as complications resulting in failure of one or more organ systems [18].

Conversion was defined as the need for a laparotomy at any time to complete the whole surgical procedure. For the postoperative pathologic results, the tumor-node-metastasis (TNM) stage (American Joint Committee on Cancer, 6th edition [19]), grade of tumor differentiation, distal and proximal resection margins, and the number of harvested lymph nodes were evaluated. Recurrence was defined as the presence of radiologically-confirmed or histologically-proven tumor. Follow-ups on patients were performed at 1 month, 3 months, then every 3 months until 2 years, and then every 6 months until 5 years. History taking, a physical examination and a tumor marker (carcino embryonic antigen) were evaluated at every visit. A colonoscopy was obtained at the 2-year visit and at the 5-year visit. A colonoscopy was obtained within 1 year if the preoperative colonoscopy was not complete due to an obstructive cancer lesion. Chest and abdominopelvic computed tomography scan were used every 6 months for the detection of local or systemic recurrences. The policy of adjuvant chemotherapy for patients followed the National Comprehensive Cancer Network guidelines [20].

Postoperative pathologic results can anticipate the long-term oncologic outcomes. The most important issue is the number of harvested lymph nodes. Oncologic resection needs proper regional lymph-node dissection [21, 22]. The suggested minimum number of harvested lymph nodes varies between 6 and 17 [23, 24], and a minimum of 12 lymph nodes is recommended for accurate staging [20]. In the present study, the mean number of harvested lymph nodes was 27.4 ± 15.1, so our results fulfill the previously recommended requirements [19, 20].

Few studies that have evaluated long-term oncologic outcomes for laparoscopic colectomies for the treatment of colon cancer have been reported even though the laparoscopoic colectomy is accepted widely in Korea [11-15]. The CLASICC trial reported a 3-year overall survival rate of 74.6% and a 3-year disease-free survival rate of 70.9% for the laparoscopic anterior resection group, and those results were not significantly different from the results for the open anterior resection group [8]. In the COST trial, the 3-year overall survival was about 85% in all stages, about 90% in stage I, about 85% in stage II, and about 80% in stage III for the laparoscopic colectomy group (Table 6). These survival results were similar to those for the open colectomy group. In the present study, the 3-year overall survival rate was 93.3%, and the other results were comparable with both the survival results of the CLASICC and the COST trials [7, 8]. Port-site recurrence has been reported to range from 0 to 0.94% [7, 25]. In the present study, port site recurrence was 0.6% and occurred in one patient.

A laparoscopic-assisted right hemicolectomy is a minimal invasive approach and shows better short-term outcomes than an open resection [7, 8]. However, Zheng et al. [26] reported a long hospital stay (13.9 ± 6.5 days) in the laparoscopic group, which was even longer (18.3 ± 5.7 days) than the open group. Baker et al. [27] found a high conversion rate in their laparoscopic patients, with a long hospital stay (9.9 ± 7.5 days) that did not differ from the open cases. However, other studies have demonstrated relatively shorter hospital stays after a laparoscopic right hemicolectomy than after an open right hemicolectomy. In the present study, the mean possible length of stay was 7.0 ± 1.5 (range, 4 to 12), and the mean observed length of stay was 9.4 ± 3.1 (range, 5 to 24). The observed length of stay is related to the Korean medical insurance system. Usually, the patients do not want to be discharged because the cost of hospitalization is very inexpensive. Thus, the mean possible length of stay of the present study was longer than the results of the COST trial (7 days vs. 5 days).

The mean operation time of 210.8 ± 80.1 minutes (range, 84 to 490 minutes) in the present study is comparable to previously reported operative times, which range from 107 to 208 minutes [28-34]. The mean number of days to 1st gas passing of 3.4 ± 1.0 days, and the mean number of days to soft diet of 6.0 ± 1.5 days in the present study are comparable to previously reported values for the mean number of days to 1st gas passing (2 to 5 days) and the mean number of days to a soft diet (2 to 5 days) [28-34].

Operative morbidity is also an important concern. The Cochrane Review of the short-term benefits of laparoscopic colorectal surgery showed a lower postoperative complication rate in the laparoscopic group than in the conventional group (18.2% vs. 23.0%; relative risk, 0.72; P = 0.02) [27]. The overall complication rate was 19.2% in the present study. However, in the present study, the complications were mostly mild complications, severe complications being rare. During the first 30 days, no mortalities were noted. Moreover, in this study, complications after 30 days occurred in 4 cases with intestinal obstruction, and the readmission rate was 4.5%. Senagore et al. [35] reported that their 30-day readmission rate was 7% in a study in which 70 cases of laparoscopic right hemicolectomies were evaluated.

In the COST, colon cancer laparoscopic or open resection (COLOR) and CLASICC trials [7-9], the conversion rates ranged from 17 to 29%. Other studies reported that the conversion rate for a right hemicolectomy ranged from 0 to 18% [28-34]. In the present study, the conversion rate was 3.2%, and the reasons of conversion were adhesion and intraoperative bleeding. A re-operation was performed in 1 case due to postoperative bleeding.

In conclusion, the short-term clinical outcomes of the present study showed the feasibility of a laparoscopic right hemicolectomy for the treatment of colon cancer. Moreover, the long-term oncologic results were acceptable. The present data support previous randomized prospective clinical trials (COST, MRC CLASSIC trial).