For bowel preparation, colonic lavage was performed the day before the surgery using 2 L Coolprep (TaeJoon Pharmaceuticals, Seoul, Korea). Systemic prophylactic antibiotics were administered intravenously at the time of general anesthesia induction. The surgery was performed under general anesthesia with the patient in the lithotomy position. A single 3.5-cm pfannenstiel incision was made and the peritoneum was opened. The Glove port (Nelis, Bucheon, Korea) was inserted into the intraabdominal space. After achieving pneumoperitoneum with insufflations of CO₂ to 12 mmHg, a Da Vinci 8.5-mm endoscope with a 30° angled view was inserted. An additional 12-mm Stapler 45 Cannula with Stapler 45 Reducer (Intuitive Surgical, Sunnyvale, CA, USA) for the wristed robotic instruments was inserted in the left lower quadrant under direct visualization. Laparoscopic exploration was undertaken using laparoscopic instruments via the additional robotic port, and accessory lumen of the single-port. The patient was put in the Trendelenburg position at 30° and tilted left side down at an angle of 15°. For the initial exposure, the greater omentum was flipped over the transverse colon toward the liver, and small bowel loops were retracted into the left side of patient's abdominal cavity. The robotic cart was subsequently placed oblique to the surgical table at an angle of 60° (Fig. 2). The camera arm was docked to the corresponding trocar, and the robotic 3-dimensional laparoscope was reinserted and attached to the camera arm. The 5 × 250-mm curved cannulas were lubricated and inserted under direct visualization via the single-port, and the R1 and R2 arms were docked using the Dock Assistant Tool (Intuitive Surgical, Sunnyvale, CA, USA) to create space around the instrument arm during docking. The R3 arm was docked to the 12-mm Stapler 45 Cannula with Stapler 45 Reducer. To maximize the instrument arm's range of motion, the set up joints of the R1 and R2 arms were positioned in straight lines. Additionally, to secure the distance between the tip of instruments and surgical field, such as superior mesenteric vessels and retrocecal recess, remote centers of R1, R2 cannulas and camera port were lifted upward out of the abdominal wall (Fig. 3A), and all three remote centers were aligned at the same level (Fig. 3B). The R1 arm was used for the nonwristed semirigid Maryland Dissector available for bipolar coagulation, the R2 arm was used for the Cadiere Forcep, and the R3 arm was used for the wristed monopolar curved scissor (Fig. 4).

The robotic second arm of Da Vinci Single-Site platform was used to lift up the ileocolic pedicle, and dissection was commenced along a vertical line to expose the superior mesenteric vein with stable and durable retraction. Primary vascular control with a D3 lymphadenectomy at the origin of the ileocolic, right colic, and middle colic vessels was performed along the right border of the superior mesenteric vein. The ileocolic vessels were ligated using EndoWrist Clip Appliers (Intuitive Surgical) (Fig. 5A) and transected at the root, while the dissection continued upwards to the gastrocolic trunk. We transected the colonic branch of the gastrocolic trunk, preserving its pancreatic and gastric branches, and exposed the middle colic artery at its origin (Fig. 5B). Following lymph node dissection in this region, the middle colic artery was ligated (Fig. 5C). An avascular surgical plane composed of Toldt's line, and prerenal fascia was exposed to uncover the head of the pancreas, second portion of the duodenum, right gonadal vessels, and ureter. The integrity of the mesocolon was strictly preserved similar to total mesorectal excision for rectal cancer. The transverse mesocolon was suspended by the robotic second arm, and the lesser sac was entered just above the head of the pancreas. Lateral mobilization was performed by retracting the cecum anteriorly, medially, and superiorly with the Cadiere Forcep in the robotic second arm. The peritoneum at the retrocecal recess was incised, and retroperitoneal avascular plane was developed.

The greater omentum of the transverse colon was subsequently transected using the EndoWrist One Vessel Sealer (Intuitive Surgical) and replaced with the monopolar curved scissors to allow entry into the lesser sac, joining the previous surgical plane of medial dissection (Fig. 5D). At this point, the fixed second arm traction on the greater omentum, and posterior wall of the stomach significantly facilitated the dissection of the omentum. After the lateral peritoneum of the ascending colon and the attachment of the hepatic flexure were detached, the gastrocolic ligament and right side of the greater omentum were dissected.

The transverse mesocolon and small bowel mesentery were divided to achieve anastomosis using the EndoWrist One Vessel Sealer. The transverse colon and terminal ileum were then transected using EndoWrist Stapler (Intuitive Surgical) through Stapler 45 Cannula. An enterotomy and colostomy were made by the monopolar curved scissors and some bowel contents were sucked by EndoWrist One Suction/Irrigator. EndoWrist Stapler was introduced to create a side-to-side anastomosis in an isoperistaltic manner (Fig. 5E). The monopolar curved scissors were replaced with Suture Cut Needle Driver (Intuitive Surgical), and the stapler insertion site was then closed with continuous stitches using V-Loc suture (Covidien, Mansfield, MA) (Fig. 5F). Finally, a drainage tube was placed at right paracolic sulci via the R3 trocar, and the specimen was wrapped in a sterile bag and extracted via the single-port incision.