A novel single-port laparoscopic operation for colorectal cancer with transanal specimen extraction: a comparative study

The prospectively collected records of patients who underwent surgery for sigmoid colon cancer and/or rectal cancer at Daejeon St. Mary’s Hospital, the Catholic University of Korea, between March 2009 and March 2013, were reviewed retrospectively (Figure 1). A total of 216 patients were enrolled at this stage. During this period, SPLS was first attempted in colorectal cancer patients eligible for operation (i.e., those who did not have advanced local disease [tumor size > 10 cm on preoperative evaluation], unresectable metastatic lesions, an American Society of Anesthesiologists’ physical status classification of IV or V, or severe medical illness). History of prior laparotomy and/or the presence of acute bowel obstruction did not preclude SPLS. Consequently, we identified 203 patients who had undergone SPLS for sigmoid colon cancer and/or rectal cancer. These patients had been treated by various operative methods via a single port, including AR, LAR, abdominoperineal resection, Hartmann’s procedure, total colectomy, transanal endoluminal laparoscopic surgery, and transabdominal transanal resection of the sigmoid colon. Of these various operative methods, single-port AR or LAR were indicated when the patients were judged to have no other colonic lesion(s) outside of the sigmoid colon and/or rectum; when primary colonic or colorectal anastomosis after sigmoidectomy seemed possible; or when the lesion was located sufficiently far from the anal verge so as to preserve the rectal sphincter and permit safe end-to-end anastomosis (EEA) stapler application. Consequently, 130 patients who had undergone single-port AR or LAR were identified. After colectomy in single-port AR or LAR, TUSE or TASE was performed to retrieve specimens. TASE was selectively performed when the tumor diameter appeared to be 5 cm or less in the preoperative evaluation and the rectal canal could be sufficiently dilated up to 5 cm with an anal trocar. Therefore, to provide a balanced comparison, we selected 83 patients in whom the tumor diameter was 5 cm or less from the patient population (n = 130), and clinical outcomes were compared between the TUSE group (n = 68) and TASE group (n = 15). This study was approved by the ethics committee at our institution (Institutional Review Board of Daejeon St. Mary’s hospital, College of Medicine, the Catholic University of Korea, IRB code: DC13RISI0079). Electronic medical records, including radiology and pathology reports, of all patients in each group were deliberately reviewed to ensure accuracy. The median follow-up was 93 months (range 13 – 149).

A complication was defined as the occurrence of any adverse event before discharge. Postoperative complications were classified as described by Clavien and colleagues [17]. Delayed gastric emptying was defined as when a nasogastric tube was required for ≥ 4 postoperative days or if its reinsertion was required, or when the patient remained intolerant to solid diet by postoperative day 7. Urinary retention was defined as when the patient could not pass urine within 12 h after removal of the urinary catheter. Operative time was measured from the time of initial skin incision to completion of wound closure, based on documentation by the anesthesiologist. Pathological margins were determined by two pathologists (Kim JO, Lee JU) based on formalin-fixed specimens. Staging was based on the 6th edition of the American Joint Committee on Cancer manual [18].

Under general anesthesia, the patient was placed in the modified lithotomy position. The operating surgeon and camera operator were positioned on the right side of the patient, and the first assistant was positioned on the left side. Usually, a 1.5- to 2.0-cm vertical incision was made at the umbilicus. Initially, we designed and used a single-port system composed of a wound retractor (ALEX wound retractor; XS, USA), a surgical glove, 2 pipes (5-mm threaded cannulas and seals; Applied Medical, USA), and a trocar (Xcel 12 mm; Ethicon, USA) (Figure 2A). Later, we replaced this system with a commercially available ready-made single port system (OCTO port; Dalim, Korea) that contains a 5-mm trocar and two 12-mm trocars (Figure 2B). After mobilization of the sigmoid colon in a medial-to-lateral fashion, we incised the retroperitoneum between the sacral promontory and aortic bifurcation while taking care to preserve the hypogastric nerve plexus. The inferior mesenteric artery and vein were then identified and divided, respectively. Next, the splenic flexure was mobilized, if necessary. The proximal rectum was dissected free, starting from the mesorectum. After the proximal and distal resection margins of the tumor-bearing segment had been determined and fully mobilized, we divided the sigmoid mesentery with a vessel-sealing energy device (Ligasure, Covidien, USA). Thereafter, the colon and proximal rectum were tied with a nonabsorbable suture (Ethibond EXCEL™ Polyester suture, Ethicon, USA) to isolate the specimen and to minimize soiling.

Total mesorectal excision (TME) was performed in all cases of rectal cancer. Before TME, we ensured the visual field by elevating the peritoneal fold (male) or the uterus (female) with an intracorporeal stitch. Anterior dissection of TME widened the gap between the anterior rectal wall and the Denonvillier’s fascia in men or the posterior vaginal wall in women. In addition, posterior and lateral dissection of TME reached the level of the puborectalis muscle. Thereafter, the proximal and distal ends of the lesion were completely enclosed with nylon tape to prevent cancer dissemination. The following steps differed according to the method of specimen extraction (TUSE or TASE).

In patients in whom TUSE was performed, the distal end of the tumor-bearing segment was divided with a stapler (Endo-gastrointestinal anastomosis [GIA] Green cartilage; Covidien, USA). The tumor-bearing segment was subsequently delivered extracorporeally through the umbilical wound after optimal extension of the skin incision. Extracorporeally, the proximal end of the tumor-bearing segment was divided, and an anvil for EEA was inserted in the remaining colon. After returning the bowel to the abdominal cavity, end-to-end colorectal anastomosis was performed with a transanally inserted circular stapler (EEA 28 mm or 31 mm; Ethicon, USA).In patients in whom TASE was performed, both the proximal and distal ends of the tumor-bearing segment were divided with a stapler (Endo-GIA Green cartilage; Covidien, USA) and endoscissors, respectively (Figure 3). The anal canal was then thoroughly cleansed by irrigation with povidone-mixed saline solution. Next, an anal trocar (i.e., a metal cylinder with a diameter of 3–6 cm) was placed through the anal canal (Figure 4A). Using a series of anal trocars, the anal canal was gradually dilated to prevent injury to the rectal wall and anal sphincter due to excessive pressure. To facilitate a purse string suture, we designed an anvil with an anchoring suture (Figure 4B). The anvil was entered into the pelvic cavity via the anal trocar and then introduced in the remaining colon. The anvil was put in the pelvic cavity via the open anal canal and was inserted and fixed in the remaining colon using intracorporeal purse string suture and Endo-GIA stapling. The specimen was extracted smoothly through the anal canal. Thereafter, the open distal rectal stump was sutured with an Endo-GIA stapler or by hand-sewn sutures. Colorectal anastomosis was completed using the transanally inserted circular stapler.

Regardless of the method of specimen extraction, a Jackson-Pratt drain was inserted through the single-port incision site, as needed.

Postoperative diet was initiated and advanced as previously described [19]. Postoperative pain was first managed by patient-controlled administration of intravenous fentanyl citrate, and additional intravenous medications for pain control were given as needed. The urinary catheter was typically removed on postoperative day 1.

The results are presented as the mean ± standard deviation and/or median (range). Continuous variables were compared with the Mann–Whitney U-test or independent t-test, depending on the normality of the quantitative variables. Categorical and ordinal variables were compared with the chi-square test. Statistical analysis was performed with SPSS version 15.0 (SPSS Inc., Chicago, IL, USA). A p value < 0.05 was considered statistically significant.

This study included 83 patients (47 men, 36 women), comprising the TUSE group (n = 68) and TASE group (n = 15). The median age was 66 years (range, 38–82 years), and the median body mass index was 23.2 (16.2–30.3). Of these patients, 52 patients (62.7%) had sigmoid colon cancer (including cancers of the rectosigmoid junction), and 31 patients (37.3%) had rectal cancer. Single-port AR was performed in 43 patients (51.8%), and single-port LAR was performed in 40 patients (48.2%). The baseline demographics and patient characteristics between these two groups were compared (Table 1). The two groups were similar in terms of baseline characteristics, such as age, sex, body mass index, or Charlson comorbidity index. There were also no differences in locations of lesions and the operative method (AR or LAR) between the two groups.

Table 2 shows the comparison of operative details and pathological outcomes between the TUSE and TASE groups. TASE resulted in a longer operative time than did TUSE (285 ± 87 min vs. 226.0 ± 78.0 min; p = 0.011). Thereafter, we illustrated individual operation times of TASE cases over time, according to the operative method (AR or LAR) (Figure 5). The sequential operation time of the TASE group appeared to decrease over time, reflecting learning processes.

The estimated blood losses and the amount of packed red cell transfusion was not significantly different between the two groups. The incidence of intraoperative complications was also not significantly different. The median largest tumor diameters in the TUSE and TASE groups were 4.0 (0.3–5.0) cm and 3.0 (2.0–5.0) cm, respectively (p = 0.220).

Next, pathological outcomes were compared. Several parameters seemed to include more advanced pathologies in the TUSE group than in the TASE group, such as tumor depth (T1, T2, and T3 stages; 16.2%, 22.0%, and 61.8% in the TUSE group, respectively; 33.3%, 46.7%, and 20.0% in the TASE group, respectively; p = 0.013) and lymphovascular invasion (86.8% in the TUSE group vs. 53.3% in the TASE group; p = 0.007).

The other parameters, including tumor cell differentiation, lymph node metastasis, tumor stage, and perineural invasion, were comparable between the two groups. In addition, the two groups showed similar oncologic results, such as sufficient attainment of surgical margins and lymph nodes.

We then assessed and compared the postoperative recovery of gastrointestinal function, which was reflected by the intervals to first flatus, to free oral fluids, and to solid diet (Table 3). The two groups showed comparable functional recovery. The frequencies of narcotic analgesics and total analgesics administration was not significantly different between the TUSE and TASE groups. The postoperative lengths of hospital stay were also similar. Overall, anastomotic site leakage was the most common postoperative complication (6/83, 7.2%), followed by delayed gastric emptying (n = 2), urinary retention (n = 4), and pneumonia (n = 1). There were 4 and 1 incidences of anastomotic site leakages in TUSE and TASE groups, respectively. Every incidence of anastomotic site leakage required reoperation. The extent of reoperation was varied according to the severity of anastomotic site leakage. The four cases of leakages developed in TUSE group required irrigation with diverting ileostomy (n = 2), primary closure with diverting ileostomy (n = 1), and transanal closure (n = 1), respectively. The one leakage developed in the TASE group was corrected by primary closure with diverting ileostomy. All the patients with leakage were recovered successfully after reoperation, and no mortality was occurred. There was no significant difference between TUSE and TASE groups in the overall postoperative complications (P = 0.196).Thereafter, we compared wound-related complications during the follow-up period. Whereas TUSE group exhibited wound seromas (n = 4), wound infection (n = 1), and umbilical hernia (n = 1), TASE group showed no wound-related complications during the follow-up period. Figure 6 shows representative illustrations of postoperative wounds with TUSE and TASE (The patients in the images have specifically provided consent to publish).