New surgical procedure which revolutionizes the previously well accepted practice usually draws strong skepticism and criticism. Since the difficulty of operation increases remarkably in SILC when compared to CLC, it is reasonable to worry that SLIC increase the time, cost, and even complication rate of operation. The potential benefits, e.g., less wound pain, faster recovery that SILC claims to offer are also strongly questioned. For surgeons who find the learning curve of SILC steep, they will consider the effort required to overcome the technical hurdle is not justified by the doubtful benefit. Although preliminary evidence supports the feasibility and safety of SILC, the controversy about SILC can only be resolved by good quality studies which compare SILC to the current standard, which is conventional multiport laparoscopic colectomy (CLC).

Currently, most of the evidence on assessment of SILC against CLC is provided by comparative studies. Outcomes of SILC are compared with patients who have CLC either in the past or in the similar time without randomization. Literature search found more than 20 reports from comparative studies on the two procedures. Most of earlier reports consisted of small number of patient with between 10 and 30 patients in each group, hence, carried little weigh in providing evidence for comparing the two procedures. The results of all these small scale studies were evaluated by a meta-analysis [18] which concluded that the results SILC are comparable to CLC.

Four reports [19–22] which were published during 2011–2013 had more than 50 patients in each group and only one [20] of them was included in the previous meta-analysis. The important results from these four studies were summarized in Table 8.1 and discussed here together. All the four study included mainly young patients with good operative risk. The mean age of patients ranged from 57.7 to 71 and more than 80 % of patients belonged to American Society of Anesthesiologist classification (ASA) 1 and 2. The comparative studied reported by Kim et al. and Champagne et al. had the largest number of patients (total of 179 and 330, respectively) with both colon and rectal resection. On the other hand, Velthuis et al. [21] and Yun et al. [22] reported on right hemicolectomy only. All four studies reported similar age and BMI, operative risk and complication rate between SILC and CLC. Single-incision laparoscopic colectomy is commonly thought to be a longer procedure because of the expected difficulty. However, only Kim et al. reported a significantly longer operation time by SILC. The two comparative studies on right hemicolectomy by Velthuis et al. [21] and Yun et al. [22] actually found that SILC had shorter operating time than CLC. On the other hand, the other two studies by Kim et al. [20] and Champagne et al. [19] found SILC to have less blood loss, reduced post-operation pain or narcotic usage. While the reduction of wound pain in SILC can be logically associated with the reduction in number of wound, the authors did not discuss about the observation of reduced blood loss or operating time in the SILC group. Kim et al. [20] also reported that SILC had significantly shorter hospital stay than CLC (9.8 vs. 15.5 days; p < 0.001). Unfortunately, the hospital stay of SILC and CLC in this report is exceptionally long. Therefore, it is difficult to interpret the meaning of this finding. Bias on case selection between the two groups is the biggest shortcoming of comparative study without randomization of subjects. It is certain that for any benefit observed in SILC procedure to be recognized widely, it have to withstand the test of well conducted randomized controlled trial (RCT).