Hamzaoglu et al. in January 2011 were the first to publish their experience with single port laparoscopic sphincter-saving excision for rectal cancer [9]. They reported a series of four patients. Two of them underwent a partial mesorectal excision with colorectal anastomosis and two underwent a total mesorectal excision. Results were encouraging as additional laparoscopic port or conversion to laparotomy was required, intraoperative blood loss ranged from 50 to 200 mL, operative time ranged from 240 to 480 min, and no postoperative complication was observed.

Since, several studies were published on the topic. After reporting our two initial cases of TME for cancer by single port approach [10], we reported the results of 25 single port laparoscopic colorectal procedures in a case-matched study, including three cases of single port laparoscopic proctectomy [11]. This study suggested the feasibility of this single port approach, as we did not observe any difference of postoperative mortality and morbidity, as compared to the standard multiport laparoscopic approach. In 2011, Bulut et al. reported ten consecutive cases of rectal cancer treated by single port laparoscopic approach with good postoperative results [12]. These results were recently updated, including 25 patients, with satisfactory results [13]. On the same way, Kim et al. [14] reported 73 colorectal cancer patients treated by single port surgery, including 32 rectal cancers. In this latter comparative study, although not randomized, postoperative morbidity was similar as compared to patients operated by multiport laparoscopy, but both return to normal bowel function and postoperative hospital stay was significantly shorter in single port patients. Additionally, two other recent papers reported 19 [15] and 8 [16] patients, respectively, with rectal cancer treated by single port, also with satisfactory postoperative results. Finally, very recently, Sourrouille et al. reported their results of 13 patients who underwent a sphincter-saving rectal resection for rectal cancer through a single port [17]. As compared to the outcomes of 32 patients who underwent the same procedure using a multiport laparoscopic approach, there was no difference in terms of oncologic quality of the resection, postoperative morbidity, or length of hospital stay. However, postoperative pain was reduced in the single port group.

In 2012, we performed a systematic review and meta-analysis on single port laparoscopic colorectal surgery [18], including all studies published as of December 2011. We identified 20 studies [9–12, 16, 19–33], all of retrospective design, which reported a total of 105 rectal procedures, including 55 low anterior resections (52 %), 4 abdominoperineal resections (4 %), and 46 total proctocolectomies (with or without ileal pouch–anal anastomosis) (44 %). Of these studies, only three were case-matched studies [11, 16, 30], all of them comparing single port to standard multiport approaches. One of the main conclusions of this meta-analysis was the questioned technical feasibility of single port laparoscopic rectal surgery, as only 67 % were successfully completed through an SIL approach. Indeed, conversion to multiport laparoscopy was needed in 32 cases (30 %) and conversion to laparotomy was needed in three cases (3 %).

On the other hand, this meta-analysis demonstrated that postoperative outcomes of single port laparoscopic rectal surgery were acceptable, as compared to the standard multiport approach. Pooled postoperative 30-day mortality rate was 0.2 % and meta-analysis of the comparative studies showed no difference of postoperative morbidity rates between single port laparoscopy and multiport laparoscopic surgery (odds ratio, 0.84 [0.61;1.15]; p = 0.27. Furthermore, we suggested that single port approach might be associated with some benefits as compared to the multiport approach as the single port approach was associated with a significantly shorter total skin incision (weighted mean difference: −0.52 [−0.79;−0.25]; p < 0.001) and a significantly shorter length of postoperative hospital stay (weighted mean difference: −0.75 [−1.30;−0.20]; p = 0.008), as compared to the multiport approach. Finally, this meta-analysis stressed out the point that single port laparoscopic surgery might be acceptable regarding the oncologic results obtained. Indeed, all reported surgical margins were negative (R0) and all studies reported a mean number of harvested lymph nodes of 12 or more. However, to date, long-term follow-up of single port TME for rectal cancer was not reported in any study and both overall and disease-free survivals remain unknown.

Similarly, two additional literature reviews have recently been published on the same topic [34, 35]. The first one [34] suggested that single port laparoscopic approach was feasible and safe when performed by surgeons highly experienced in laparoscopy. The authors concluded that, despite technical difficulties, single port laparoscopy might be associated with potential benefits (i.e., size of the incision, hospital stay, operative time) as compared to its multiport counterpart, but those remain yet to be proven objectively. The second review, focusing only on colon cancer [35], suggested that single port laparoscopic approach may be associated with a lower postoperative morbidity rate, as compared to the results of large randomized control trials of multiport laparoscopic approach.

More recently, two small-sampled randomized studies have been recently reported on single port laparoscopic colonic surgery [36, 37], although they did not include rectal procedures. The first one, authored by Poon et al., included 50 patients and demonstrated significantly shorter hospital stay and lower postoperative pain in patients operated by single port [37]. The second study in 32 patients demonstrated that operative results were similar in both single port and standard laparoscopy groups [36].

Several authors published their experience with transanal–transabdominal TME. Different surgical techniques were reported, mostly because of variations of the percentage of the TME dissection performed through the transanal approach. Indeed this transanal dissection may vary from an isolated intersphincteric dissection, as we previously described [10], to a complete TME [38], associated with a single port transabdominal approach.

The complete transanal TME derives from the natural orifice transluminal endoscopic surgery (NOTES) technique, initially described in bovine [39] and human cadaver [40] and firstly described in human using a multiport laparoscopic assistance by Sylla et al. [41]. In 2011, Tuech et al. reported the first case of complete transanal TME with a single port laparoscopic assistance in a 45-year-old for a low rectal adenocarcinoma [42]. In September 2012, Dumont et al. reported the first series of four patients with rectal cancer treated with this approach [38]. Results were encouraging, as additional laparoscopic port or conversion to laparotomy was not required, mean intraoperative blood loss was 175 mL, and all surgical margins were classified R0. After a mean follow-up of 3 months, Wexner scores indicated no severe incontinence in any patient. The authors concluded that this technique was feasible despite the limited working space in the pelvic area. Furthermore, they hypothesized that this transanal approach for TME may be superior to the transabdominal TME for large pelvic tumors, minimizing the risk of perforation and presacral bleeding. Similar results were observed regarding an updated population of seven patients in 2013 [17]. Choi et al. also published their results of 22 patients operated on with this technique [43]. No intraoperative complication was observed and no additional port or conversion to open surgery was required. Furthermore, the median number of harvested lymph nodes was 22 and the median distal margin from the tumor was 2 cm, suggesting a satisfactory oncologic resection. However, to date, no study compared the results of the transanal TME to those obtained after transabdominal approach. In our department, we consider that a total transanal TME presents two major drawbacks: firstly, the major anal sphincter required might jeopardize the postoperative anal function; secondly, a hand-sewn coloanal anastomosis is the rule after this technique, irrespective of the tumor distance from the anal verge and therefore even in mid-rectal cancer where stapled anastomosis is feasible. For these reasons, when a hand-sewn anastomosis is indicated (i.e., low rectal cancer), we always begin the TME dissection from a perineal approach but only up to approximately 5–6 cm from the dentate line. Subsequently, we routinely performed a standard abdominal laparoscopic approach.