Different kinds of access ports are commercially available and include SILS port (Covidien; Mansfield, MA), R-Port (ASC, Wicklow, Ireland), homemade port using a surgical glove and Alexis wound retractor (Applied Medical, Santa Margarita, CA, USA), GelPort or GelPoint (Applied Medical, Santa Margarita, CA, USA), OCTO Port (Dalim, Korea), TriPort and QuadPort (Olympus, Japan), and da Vinci SS platform (Intuitive, USA). Apart from da Vinci single-site platform, which is exclusively for robotic single-port surgery and is attached to da Vinci Si system, almost all of the access ports were originally for laparoscopic single-port surgery. A few of these access ports have been evaluated in literature. Thus far, among commercially available access ports, only SILS port [9] and GelPort [14] have been used in published literature on robotic single-incision surgery. Based on these reports, the SILS port seems to have limitations in the size of the whole access port. It tends to be too small for robotic instruments, which are bulkier than laparoscopic instruments, and spaces between the instruments are inadequate, which results in frequent arm collision and limitation of range of motion. Another limiting factor is that there is limited room for a third robotic arm or for an assistant. GelPort may be a better alternative because it allows the surgeon to design individual port configurations within the access port and may help overcome the limitations in space, crowding of robotic arms and external clashing.

Our preference is a homemade port using a surgical glove and Alexis wound retractor. The glove port offers multiple advantages over commercially available products. Its construction is simple and additional cost is negligible since the Alexis wound retractor would have been used in standard laparoscopic or multiport robotic colorectal surgery for specimen extraction. Other major benefits of this port include accommodation of variable abdominal wall thickness and the virtual absence of air leaks, which frequently hinder procedures involving standard MIS ports [12].

Laparoscopic single-port surgery has been widely described for appendectomy and cholecystectomy. Although most reports have small numbers related to a single surgeon’s experiences, information pooled from these series regarding access port evaluation and technical tips make a firm base for performing more complex and multiquadrant procedures like colorectal surgery.

Another factor that has facilitated single-port surgery has been the evolution in surgical tools such as advanced articulating or flexible instruments including even energy devices, staplers, and endoscopes.

In a large systematic review, Makino et al. in 2012 examined the safety and feasibility of laparoscopic Single-port colorectal surgery for both benign and malignant conditions [15]. He reviewed 23 studies including 378 patients. The conversion rate was 1.6 % (6 cases) to open, 1.6 % (6 cases) to hand-assisted laparoscopy colectomy (HALC), and 4 % (14 cases) to conventional multiport laparoscopy. Additional laparoscopic ports were required in 12 patients out of 247 (4.9 %). The overall mortality and morbidity rates were 0.5 % (2 cases) and 12.9 % (45 cases), respectively. The causes of death were pulmonary embolism and metastasis for a palliative case. Of the four case-matched studies two studies showed shorter hospital stay for the single-incision laparoscopy than HALC and multiport laparoscopy. One study reported lower postoperative pain in SPLS over multiport and HALC. The readmission rate reported in two studies were 6.3 and 13.8 %, and when compared to multiport surgery found not to be significantly different. The reported complications from laparoscopic single-port surgery in literature were ileus, wound infection/hematoma, and anastomotic bleeding/leakage, which also were observed in multiport surgery as well as conventional open. Makino in his review concluded that despite the technical difficulty, in early series of highly selected patients laparoscopic single-port colorectal surgery was found to be safe and feasible in the hands of highly skilled surgeons. However standardization of the technique, learning curve and long-term evaluation are still in its infancy and need to be evaluated in large randomized controlled trails.

Robotic colorectal surgery was reported in 2002 by Weber et al. [16]. Since then this has been adopted by colorectal surgeons in high-volume specialized centers. Recently meta-analysis and several large systematic reviews have confirmed the safety and feasibility of robotic colorectal surgery without inferiority in oncological outcome. Furthermore, randomized controlled trials are ongoing to provide a better level of evidence for this procedure. The advantages of the robotic approach articulated in published robotic papers largely focus on better high-definition three-dimensional vision, filtration of physiologic tremor, human wrist-like motion of robotic instruments, stable camera control, better ergonomics, and reduction of the fatigue associated with conventional laparoscopy.

These advantages of the robotic interface help overcome many of the limitations of single-port surgery such as internal and external collisions, difficulty in achieving traction for triangulation, loss of ergonomics, body fatigue, instability of the camera, poor positioning with the assistant, and lack of stereotactic sense due to a two-dimensional view. Although efforts have been made to minimize the above limitations with use of articulated instruments and special cameras, the results have been less than perfect with limited adoption by laparoscopic surgeons. This is more so in colorectal surgery where multiquadrant access is required. By adopting the robotic system to single-port approach, theoretically surgeons can have stable and three-dimensional operative view and human wrist-like functioning robotic instruments that allow adequate traction and counter-traction. Additionally, the surgeon can restore intuitive control of the instruments in the operative field despite the instruments being crossed by reassigning the hands at the console so that the instrument in the operative field corresponds to the appropriate hand on the console.

There are, however, some potential drawbacks of using the robotic system to perform single-port surgery. Because the robotic arms are bigger than laparoscopic instruments, a larger size skin incision may be necessary. Additionally, this may also limit the ability to introduce additional laparoscopic instruments through the access port, as is commonly done in laparoscopic single-port surgery.

The first robotic single-port surgery for radical prostatectomy was published by Kaouk et al. This was followed by pyeloplasty and nephrectomy; since then, several animal as well as human trials have been published for numerous benign and malignant procedures. In the colorectal field, robotic single-port surgery is still a novel technique and only a few surgeons have reported their results in literature (Tables 22.2 and 22.3).

Ostrowitz et al. was the first to publish about robotic single-port colectomy in 2009 [9]. He reported a three robotic single-port right hemicolectomy using da Vinci S system and 3 ports including a camera inserted through one incision. The incision was through or around the umbilicus with a 4-cm length incision. There were no reported complications. The average operative time was 152 min. The first case was converted to non-robotic single-incision right hemicolectomy during mobilization of the ascending colon, due to uncontrollable air leakage around the ports. The second and third cases were successfully completed without air loss by purse-stringing sutures around each individual port and the use of the SILS port, respectively.

Singh et al. in 2010 reported the first case of robotic single-port right hemicolectomy [14]. He performed the procedure using a GelPort as an access port through a 4-cm abdominal incision. Their operative time was 179 min and estimated blood loss was minimal. There were no reported intra-/postoperative complications. In 2012 Lim et al. published a multimedia article about robotic single-port anterior resection for sigmoid colon cancer [12]. They reported short-term results of 20 patients who underwent this procedure. The mean estimated blood loss was 24.5 ml (range 5–230). The mean operative time was 167.5 min (range 112–251), and there were no conversions. The median skin incision length was 4.7 cm (range 4.2–8). The mean proximal and distal resection margins were 12.9 (range 7.5–25.1) and 12.3 cm (range 4.5–19.2), respectively. The mean harvested lymph node was 16.8 (range 0–42). The immediate postoperative pain score was 2.8 (range 1–5) and 1.4 [1–3] on the first postoperative day. The mean length of hospital stay was 6 days (range 5–9). Obias et al. reported their comparative study between robotic and laparoscopic single-port colectomy [17]. They compared 11 patients having robotic single-port colectomy to 10 patients receiving laparoscopic single-port colectomy. In the robotic group all of the patients had single-port right hemicolectomy with three conversions to conventional laparoscopy. There were three cases of postoperative complications (ileus, anastomotic bleeding, and wound infection). The laparoscopic group consisted of hemicolectomies and ileocecectomies. One case was converted to open due to adhesions, and one case had postoperative bleeding requiring drainage. There was no statistically significant difference in measured clinical parameters between the two groups.