In 1982, RJ Heald published and advocated the technique of total mesorectal excision (TME) for the surgical treatment of rectal cancer. The technique emphasized sharp dissection between the visceral mesorectal fascia and parietal pelvic fascia, that is, the “Holy Plane” with the preservation of the autonomic nerves [4]. This technique has dramatically decreased the local recurrence and has become the gold standard of rectal cancer surgery [5]. In the recent two to three decades, the minimally invasive surgery approach opened a new page in colorectal surgery. Comparative studies and randomized trials have demonstrated favorable clinical outcomes for laparoscopic resections while achieving similar oncologic results as the open approach for colorectal cancers [6–9]. Some of the advantages of the laparoscopic approach include faster postoperative recovery, reduced wound pain and shorter hospital stay. In the case of rectal cancers, especially low rectal cancers, there were initially concerns regarding its safety and the relatively high conversion rate [10]. Fortunately, subsequent studies were able to show minimally invasive rectal cancer surgery, in particular laparoscopic TME, to be an oncologically safe approach even for distal rectal cancers [11–13]. Laparoscopic TME has now become a standard surgical treatment for mid to low rectal cancers.

Further development in minimally invasive colorectal surgery aims to reduce the number and length of the incisions as well as to explore the possibility of natural orifice surgery. While significant enthusiasm on natural orifice transluminal endoscopic surgery (NOTES) began a decade ago, wide application of NOTES is still limited by many issues. However, single-incision laparoscopic surgery has been developed to reduce the number of abdominal incisions. The use of the umbilicus as in single incision laparoscopic surgery is also regarded as one form of natural orifice surgery.

Despite the complexity of colorectal surgery , which includes multiquadrant dissection, division of sizable vessels, and restoration of bowel continuity, the first single-incision laparoscopy (SILS) right hemicolectomy was published in 2008 [14, 15]. This technique was later shown to have certain advantages like less postoperative pain and faster recovery compared to conventional multiport laparoscopy [16–18]. But when SILS was applied to surgery that involves the rectum, the anatomical confines from a narrow bony pelvis, the lack of multidirectional retraction of the rectum, and the inevitable clashing of instruments and camera render this procedure rather intimidating. Given these additional hurdles, whether one would be able to observe the same principle of meticulous dissection under direct vision as proposed by Heald was questionable. Indeed, SILS TME should be reserved for a select group of patients and be performed by surgeons who are highly skilled in SILS technique. In this chapter, we will discuss the technical aspect of SILS TME and some of the tricks to overcome the technical challenges.

Patients with mid or low rectal cancers are indicated for TME. Preoperative workup is equivalent to that of the open or laparoscopic approach. Preoperative anesthetic assessment is crucial for patients with medical comorbidities. Bedside digital examination serves as an informative tool prior to sophisticated investigations. Tumor location, with special consideration to its relationship with the sphincter complex, mobility of the tumor, and anal tone could be ascertained. Colonoscopic evaluation and histological confirmation is essential. Endoscopic tattooing of small rectal cancers is rarely of any value as these mid to low rectal cancers could be felt digitally. Staging is performed by imaging studies including contrast-enhanced computed-tomography of the abdomen and magnetic resonance imaging (MRI) of the pelvis. Endorectal ultrasound can be performed for early disease (T1/T2). T3 tumors, mesorectal lymph node involvement, and threatened circumferential radial margin are common indications for neoadjuvant treatment. A multidisciplinary meeting with expertise from oncologist and radiologist is recommended in this regard. The optimal time interval between neoadjuvant treatment and surgery is still controversial and we would perform the operation at least 8 weeks after completion of radiation [19].

Patient selection criteria for SILS are similar but more stringent than multiport laparoscopy (MLS). Basically, patients with favorable body habitus and tumor characteristics are preferred. Morbidly obese patients, although not an absolute contraindication, will definitely increase the difficulty of pelvic dissection and the chance of conversion [18, 20, 21]. Cardiorespiratory comorbidities or uncorrected coagulopathy would render the patient less suitable for either MLS or SILS, and should be approached with caution. Large and locally advanced lesions are not suitable for SILS. With a larger lesion, the difficulty will increase and there is a need to make a bigger incision to retrieve the specimen, which partly defeats the purpose of SILS [22]. Locally advanced tumor with infiltration to surrounding structures, for example, prostate, should definitely be avoided.

Although the use of mechanical bowel preparation is controversial [23–25], it is preferred in TME to avoid the presence of stool distal to the diverting stoma. It also facilitates the use of intraoperative colonoscopy if there is a need to look for a synchronous tumor. While we do not use oral antibiotics before the operation, intravenous antibiotic prophylaxis with a second-generation cephalosporin is given on induction of anesthesia. Urethral catheterization should always be performed. Deep vein thrombosis prophylaxis is achieved by intermittent pneumatic calf compression and low molecular weight heparin.

Patient is placed in the modified lithotomy position in which the hips are abducted and slightly extended and the knees flexed. The arms should be tucked and body strapped to the table to prevent sliding from the operating table. Pressure areas should be carefully padded. The lower part of the sacrum should be sitting at the distal edge of the table.

There are multiple SILS access devices in the market as well as different versions of innovative self-adapted method incorporating existing MLS instruments. Specialized SILS devices include the TriPort™ Access System (Olympus, Japan), SILS™ Port (Covidien, USA), X-Cone (Karl Storz, Germany), OCTO™ Port (Dalim, Korea), and GelPOINT Advanced Access Platform (Applied Medical, USA). These devices usually house three to four 5–12 mm ports in them. They are designed to prevent air-leak, minimize clashing of the smaller ports, allow maximal instrument range of motion and maximize the already compromised triangulation of instruments. These are crucial to a successful SILS procedure. Some examples of self-adapted method include the glove-wound protector technique [26, 27], inserting multiple trocars via a single incision [1, 28], and the technique of inserting conventional trocars through a Gelport (Applied Medical, USA) [29]. These methods, though innovative, are less robust in terms of preventing air-leak and instruments clashing and should be largely replaced by specialized device in technically demanding operations like TME.

In order to overcome coaxial alignment of the laparoscope and instruments, deflectable laparoscopes have been designed. With current technology, some of these scopes have a diameter of 5 mm. Deflectable Tip EndoEYE™ (Olympus, Japan) and the IdealEyes™ HD Articulating Laparoscope (Stryker, USA) are examples of deflectable laparoscope. More so, deflectable laparoscopes providing three-dimensional view have emerged in the market.

Articulating or curved laparoscopic instruments have been designed to tackle the loss of triangulation in SILS. Studies, however, failed to show that the use of articulating instruments result in better performance or a shorter learning curve in SILS [30, 31].

The authors’ preference has been a straight 10 mm 30° laparoscope with high-definition camera and straight laparoscopic instruments. The issue of coaxial alignment can partly be addressed by manipulating the orientation of the light cable. The majority of laparoscopic surgeons are familiar with straight laparoscopic instruments and the feasibility of its use in SILS is well documented in the literature [22, 32–34]. While the use of articulating instruments requires psychometric adaptation , the transition from MLS to SILS would probably be smoother if surgeons operate with instruments they are accustomed to.

Hamzaoglu et al. published the first case series on SILS sphincter-saving surgery for rectal cancer [35]. The series involved two partial mesorectal excisions and two TME. Subsequently, there were other series showing SILS TME to be a feasible procedure with oncological clearance comparable to MLS [27, 36, 37]. Nevertheless, SILS TME was not a very popular procedure and this could be partly reflected by the lack of large volume series in the literature. Studies have demonstrated favorable postoperative outcome in terms of faster recovery and less postoperative pain in SILS but many of these included only colectomies and high anterior resections; cases of low rectal cancer were excluded [38–40]. SILS rectal resection was associated with a longer operation time with significant higher chance of multiport conversion [41]. The conversion rates to MLS and laparotomy were 30% and 3%, respectively, in a systematic review by Maggiori et al. [42]. Apart from higher conversion rate, more cartridges may be required to transect the low rectum [35]. Under such circumstances, some devised the technique of using one additional port, the reduced port technique, for that purpose [43].

While the current evidence in the literature highlighted some of the technical issues behind SILS TME, a feasible solution emerged over the horizon. Whiteford performed the first transanal rectal mobilization on cadavers [44]. The first clinical case was later performed by the team of Sylla and Lacy [45]. This is a novel technique that involves rectal dissection with a bottom-to-up approach. The initial results demonstrated feasibility and safety in terms of oncological clearance [46]. The potential advantages of such technique include precise determination of the distal margin and better visualization of the low rectum. The distal rectum would be divided upfront, obviating the need to transect with stapler in the pelvis.

The technique described by the pioneers achieved sigmoid colon mobilization and division of vascular pedicles by MLS. The rectal dissection is performed using a transanal platform, which resembles a SILS platform (Fig. 10.2). The rectal lumen is closed distal to the tumor. After dividing the rectum circumferentially, the rectum is mobilized, following the same avascular plane used in the conventional technique, only from the opposite direction (Fig. 10.3).

Tuech was first to report SILS combined with transanal rectal resection in a female patient [47]. Subsequently, Gaujoux and Dumont published similar case series with four male patients in the latter series [48, 49]. The initial results were encouraging. Choi reported a case series of 22 patients; the median operating time was 260 min and the complication rate was 4.5% (Clavien-Dindo Grade III or above) [50]. The conversion rate was 0%. However, hand-sewn coloanal anastomosis was fashioned almost exclusively in the initial reports. Stapled colorectal anastomosis was reported by Velthius and Chen [51, 52]. In our opinion, we prefer to perform stapled colorectal anastomosis if possible. This is to avoid unnecessary morbidities from an ultra-low anastomosis. Hand-sewn coloanal anastomosis should be reserved for those with ultra-low rectal tumors, which mandates intersphincteric dissection.

Transanal TME may ultimately addresses the technical limitations of SILS TME. This combined approach allows the surgeon to follow the same oncological principles with low conversion rate while operating on patients with low rectal cancers.

The principles of SILS TME are the same as per open and laparoscopic. The operation is divided into the following steps.