Screening programs for the early detection of colon cancer have become common. Nevertheless, 8% to 29% of colon cancer patients visit the hospital with acute colonic obstruction [1]. Since the right colon has a larger diameter than the left colon, the rate of obstruction is relatively low (35% vs. 65%) and 1-stage right hemicolectomy and anastomosis are preferred over the 2-stage procedure [2]. On the other hand, the diameter of the left colon is relatively small, so obstruction is more likely to occur, and there is still debate over the appropriate surgical procedure in this situation. The traditional method is the 2-stage Hartmann procedure (HP), or primary diverting colostomy. However, the HP procedure has disadvantages surrounding complications related to stoma and the need for a second operation. Moreover, about 45% of patients undergoing HP have to live with permanent stoma [3].

Perioperative placement of a self-expandable metallic stent (SEMS) has been used as a bridge to elective surgery and reported with a high success rate of 93.8%. Primary anastomosis was performed in 91.8% of patients and stoma creation was required only in 10.6% to 23.9% of patients [4-6]. In addition, SEMS makes preoperative colonoscopy possible with the advantage of being able to determine synchronous colon cancer in the proximal colon. However, colonic perforation occurred after SEMS in 1.5% to 8.9% of patients [4-6]. Moreover, stent-related perforation has been reported that is associated with an increased risk of global and locoregional recurrence of cancer [7]. As a result, a 1-stage procedure claimed to solve these problems that includes segmental colectomy (SC) with or without intraoperative colonic irrigation and subtotal colectomy (STC)/total abdominal colectomy (TC).

SC and STC/TC are known to have low mortality and morbidity [8, 9]. In several studies comparing SC and STC/TC, different conclusions have been drawn. Kaser et al. [10] reported the rate of anastomosis leakage was lower in STC/TC compared to SC. On the other hand, Mege et al. [11] reported the rate of anastomotic leakage under SC was not higher than STC/TC. However, 15% of SC patients required diverting ileostomy. Ileostomy may have helped to reduce anastomotic leakage, but this procedure did not play a role as a true, 1-stage procedure [11]. In most studies, STC/TC is reported as a safe 1-stage procedure that does not require a stoma, and the rate of anastomotic leakage reported has been very low [12-14]. Also, in a functional aspect, 31.2% of patients had diarrhea in the immediate postoperative period but most symptoms naturally improved or were controlled by antidiarrheal medication, and disabling diarrhea was reported in only 6.2% of patients [15]. Average bowel movement after 3 to 6 months and 12 months after surgery was reported as 2 stools per day [13, 14].

Despite these advantages, STC/TC is not generally chosen for the treatment of obstructive left colon cancer (OLCC). Mege et al. [11] reported only 13% use of the STC/TC procedure for OLCC in France. This result is considered to be due to concerns about morbidity or mortality caused by extensive resection, functional status, and lack of long-term data. Therefore, this study evaluated the perioperative morbidity, mortality, functional, and oncologic feasibility by analyzing the short-term and long-term outcomes of STC/TC.

The rate of morbidity and mortality of emergency surgery for OLCC has been reported as high [16, 17]. Therefore, 2-stage procedures have been the classic choice of treatment to reduce operative morbidity and mortality caused by an unprepared bowel. However, stoma that are created to avoid complications not only cause other complications associated with the stoma but also deteriorate the quality of life [18]. The stoma reversal rate after HP is significantly lower than diverting loop ileostomy (50% vs. 90%) [19]. Also, complications related to stoma reversal cannot be overlooked. Garber et al. [20] reported that 29.1% of patients had postoperative complications after reversal of HP. Especially, they reported 3.8% anastomotic leak and 1.9% mortality. Moreover, 35% of patients who underwent HP could not undergo reversal surgery because of underlying general conditions [3, 21]. Therefore, the demand for a safe, 1-stage procedure that does not require a stoma is high.

One-stage procedures mainly include segmental resection with perioperative SEMS or intraoperative colonic irrigation and STC/TC. Perioperative placement of SEMS to bridge elective surgery has been used and reports a high success rate of 93.8%. Also, primary anastomosis could be performed in 91.8% of patients, and stoma creation was required only in 10.6% to 23.9% of patients [4-6]. In addition, preoperative colonoscopy has the advantage of being able to determine the presence of synchronous colon cancer in the proximal colon. However, complications such as perforation may occur in 1.5% to 8.9% of patients due to SEMS [4-6]. Stent-related perforation is also associated with an increased risk of global and locoregional recurrence [7]. Currently, the European Society of Gastrointestinal Endoscopy guidelines and the latest Cochrane Systematic Review state that stent placement is not the treatment of choice in patients with potentially curable diseases and may be considered as an alternative to emergency surgery in patients with increased risk of perioperative mortality [22, 23].

SC with intraoperative colonic irrigation and STC/TC are both known to have low mortality and morbidity [8, 9]. In several studies comparing SC and STC/TC, different conclusions were drawn. Kluger et al. [9] reported the rate of anastomotic leakage was lower in STC/TC compared to SC [10]. On the other hand, in a recent French multicenter trial, the rate of anastomotic leakage in SC was not higher than STC/TC. However, in that study, 15% of SC patients needed diverting ileostomy [11], indicating that these procedures, in reality, are not truly 1-stage procedures. Even loop ileostomy has the risk of morbidity in formation (12%) and reversal (17.3%–21%) [24, 25].

Another problem with SC with intraoperative irrigation is that it is difficult to detect synchronous colon cancer. In colon cancer patients without obstruction, preoperative colonoscopy could detect 5% to 7% of synchronous colon cancers [26-28]. In this study, synchronous colon cancer was detected in 9.1% of patients (5 of 55). When the range expanded, adenoma was detected in 41.8% of patients (23 of 55), and 17.4% of them (4 of 23) were reported as high-grade dysplasia. For these reasons, early colonoscopy follow-up is generally warranted after SC. However, if synchronous colon cancer is detected, reoperation is inevitable.

STC/TC is a safe 1-stage procedure that does not require a stoma. The rate of anastomotic leakage is reported as 0% to 2.8% [10, 12-14]. The anastomotic leakage rate of STC/TC is not higher than the known rate of elective right hemicolectomy or SC (2.8% and 2.3%, respectively) [29]. One report showed that the rate of anastomotic leakage was as high as 14% after STC/TC [11]. However, compared with previous reports, the gap in the rate was too large. It is difficult to accept this rate as general. In this study, the rate of anastomotic leakage was 0% without any diverting ileostomy.

Compared to other surgeries, STC/TC requires a relatively longer operation time because the area to dissect is larger. In this study, the average length of surgery was 175 minutes (range, 155–210 minutes). Therefore, in hemodynamically unstable patients, primary diverting colostomy would be the safer option relative to STC/TC. Our study did not include hemodynamically unstable patients; however, compared with SC with intraoperative colonic irrigation, the operation time of STC/TC was reported as shorter [15]. Therefore, except for patients that are hemodynamically unstable or have severe comorbidities that require the avoidance of long operation time, STC/TC is accepted as an available operative option.

Morbidity and mortality for OLCC operation were reported as high as 28.0% and 7.0%, respectively, and the rate of severe complications (more than Clavien-Dindo grade III) was reported as 7.0% [11]. The rate of postoperative morbidity in this study was similar (21.8%) and the rate of severe complications and mortality was relatively low (1.8% and 0%, respectively). What is remarkable in this study is that anastomotic leakage or surgical site infection were not observed. There are several hypotheses for why the anastomotic leak rate is low in STC/TC. First, the mobility of the small bowel allows the surgeon to perform ileo-colic or ileo-rectal anastomosis without tension. Second, the ileo-colic anastomosis benefits from an optimal blood supply due to the high vascularity of the ileum [30]. Based on these concepts, there is no reason for the leakage rate of STC/TC to be higher than that of right hemicolectomy. However, postoperative ileus was relatively common (18.2%), and 1 patient needed reoperation due to prolonged postoperative ileus. The larger raw surface in the region of dissection and large defects created by excising the area of the colon are thought to be the cause of postoperative ileus.

Functional aspects are big concerns with respect to the use of STC/TC. In a previous randomized controlled trial, increased bowel frequency (3 or more bowel movements per day) was more common in the STC group than in the SC with intraoperative colonic irrigation group during the immediate postoperative period [8]. In another study, 31.2% of patients who underwent STC/TC had diarrhea during the immediate postoperative period. However, most symptoms naturally improved or were controlled by antidiarrheal medication, and disabling diarrhea was reported in only 6.2% of patients [15]. The average bowel movement after 3 to 6 months and 12 months after surgery was reported as 2 stools per day [13, 14]. This study showed similar results. In the 6 to 12 weeks after surgery, 14.5% of patients required antidiarrheal medication, 7.3% of patients complained of mild diarrhea (less than 4 times a day), and 7.3% of patients complained of moderate diarrhea (4 or more times a day). After 1 year, only 5.5% of patients required antidiarrheal medications. The length of the remaining colon and the resected terminal ileum are known to be important factors influencing the occurrence of diarrhea after surgery [31]. In our study, the terminal ileum was carefully resected within 10 cm, and the rectal resection was always above the level of the pelvic promontory to preserve more than 10 cm of the rectum.

Patients diagnosed with obstructive colon cancer and underwent 1-stage emergency curative treatment were reported with worse long-term survival than patients with nonobstructive lesions [32, 33]. The long-term outcome of this study was relatively favorable compared to previous studies [11, 34]. Since this study was not designed as a comparative study, it is difficult to directly compare results.

The number of lymph nodes evaluated after surgical resection of colorectal cancer is a known predictor of survival [35]. In this study, there are no cases involving less than 12 lymph nodes, and the median number was 42. Although this number is higher than that of SC, its clinical significance is not clear because it includes lymph nodes of the right-side colon. However, the main reasons for our results are that all surgeries involved were performed by colorectal specialists and the surgeries were performed according to the oncologic principle.

The noncomparative design, small number of included patients, and short period of follow-up are limitations of this study. However, the safety and the benefits of STC/TC were confirmed. In order to verify these results, prospective, large-scale, randomized controlled trials will be needed.

In conclusion, STC/TC for OLCC is a safe, 1-stage procedure that does not require diverting stoma. The advantages of STC/TC also include the elimination of synchronous and potentially metachronous colon tumors and the removal of proximal dilated colon, most importantly, the risk of anastomotic leakage observed is very low. Most patients did not complain of diarrhea or were well controlled with medication and severe diarrhea rarely occurred after surgery. In addition, the 3-year OS and DFS are also acceptable. Therefore, STC/TC is a reasonable treatment option for OLCC.