Minimally invasive techniques: Left/sigmoid colectomy and proctectomy

INTRODUCTION — Minimally invasive approaches to colon and rectal resection have resulted in earlier tolerance of diet, accelerated return of bowel function, lower analgesic requirements, and shorter length of hospital stay. (See "Surgical resection of primary colon cancer", section on 'Open versus laparoscopic colectomy'.)

While large multicenter randomized trials have shown comparable disease-free and overall survival between open and laparoscopic approaches for colon cancer [1-3], the same has not been uniformly found for rectal cancer. There has been considerable controversy regarding the long-term outcomes and safety profile of minimally invasive surgery for rectal cancer [4-9]. Thus, although some studies have shown equivalent results between robotic, laparoscopic, and open surgery [4-11], minimally invasive approaches for rectal cancer should be limited to appropriately designed trials and experts in high-volume centers until more long-term outcomes are published. (See "Radical resection of rectal cancer", section on 'Laparoscopic versus open'.)

Minimally invasive colorectal resection can be performed with laparoscopic-assisted, hand-assisted, or robotic-assisted techniques. Various minimally invasive techniques differ in instrumentation and setup but not operative principles. The techniques of laparoscopic and robotic left/sigmoid colectomy and proctectomy are described here; the authors' techniques are not the only viable techniques that can be used for left/sigmoid colectomy or proctectomy.

Other topics related to colorectal resection techniques include:

●(See "Right and extended right colectomy: Open technique".)

●(See "Left colectomy: Open technique".)

●(See "Radical resection of rectal cancer" and "Surgical treatment of rectal cancer".)

●(See "Restorative proctocolectomy with ileal pouch-anal anastomosis: Laparoscopic approach".)

OPERATIVE APPROACH

Patient positioning — The patient is placed on the operating room table in the lithotomy position with stirrups, allowing concurrent access to the abdomen and perineum (figure 1). Both arms are padded and tucked, and a chest strap is used to secure the patient to the table to limit movement with repositioning. When used, the Xi robotic system is positioned perpendicularly to the patient's left (figure 1).

Trocar placement — Access to the abdominal cavity can be obtained through various approaches (see "Abdominal access techniques used in laparoscopic surgery"). We typically utilize an optical trocar placed under direct visualization in the midline, either superior or inferior to the umbilicus, and approximately 15 cm away from the target anatomy. If the trocar is placed too far away from the target, visualization deep in the pelvis can be an issue. Once the initial trocar is in place, and the abdomen is insufflated, additional trocars are placed under direct visualization.

For a laparoscopic approach, 5 mm trocars are used and placed in a baseball diamond configuration. One is generally placed two fingerbreadths above the pubic tubercle in the midline, another two to three fingerbreadths away from and oblique to the left anterior superior iliac spine (ASIS), and the last a few fingerbreadths away from and oblique to the right ASIS. Depending on body habitus, the positioning of the trocars may need to be altered and more trocars used (figure 2).

To decrease potential external arm and internal instrument collisions for a robotic approach, a distance of 8 to 10 cm between trocars is recommended for the S and Si robotic systems and 6 to 8 cm for the Xi platform. Working trocars placed too lateral or far away from the target anatomy can pose problems with reach.

We utilize an Xi robotic system and uniformly place the trocars across the abdomen horizontally with the camera. The laparoscopic camera port is switched to an 8 mm robotic trocar (arm 3); two 8 mm trocars are placed on the left side of the abdomen (arms 1 and 2) and one 12 mm trocar on the right (arm 4) (figure 3). Robotic instruments, including Hot Shears (monopolar curved scissors), EndoWrist One Vessel Sealer, and Endowrist Stapler, are interchangeably used in arm 4, the camera in arm 3, the fenestrated bipolar forceps in arm 2, and a Small Graptor (grasping retractor) in arm 1.

Working deep in the pelvis, the arm 4 instrument's shaft can hit the sacral promontory, hindering appropriate movement, reach, and dissection. Placing the trocar lower along an oblique line between the right ASIS and camera port (arm 3) will resolve that issue.

A 5 mm assistant port is placed between and slightly above arms 3 and 4. If placed higher, the shaft of the suction device can hang on the sacral promontory, limiting reach behind the mesorectum deep in the pelvis. When utilizing an integrated insufflator/smoke evacuator (eg, AirSeal), an 8 mm trocar is placed as the assistant port. When working deep in the pelvis, two assistant trocars are often helpful, allowing an assistant to perform suction and retraction simultaneously with two different instruments. This can be accomplished by placing the extra assistant trocar higher in the right upper quadrant (picture 1).

If planning for an intracorporeal anastomosis, the Pfannenstiel extraction incision can be created at the time of trocar placement to introduce the stapler anvil quickly. A medium wound protector with a laparotomy pad wrapped around the base will maintain pneumoperitoneum (picture 1).

Laparoscopic/robotic left/sigmoid colectomy

Setup — A Trendelenburg position is utilized to move the omentum and intestine cephalad, allowing for an unobstructed view of the sigmoid/left colon. Right lateral decubitus positioning may also be necessary to provide unhindered access to the inferior mesenteric artery/vein, mesocolon, retroperitoneum, splenic flexure, and colon. If obstructing the view and dissection planes, the small intestine can be wrapped like a cocoon in a moist laparotomy pad placed through the Pfannenstiel incision. Alternatively, a mini-laparotomy pad can be used and placed through the 12 mm trocar. The assistant can then push gently on the laparotomy pad and move the small bowel as one unit out of the field.

Medial-to-lateral mesocolic dissection (with video) — The rectosigmoid junction is grasped with an atraumatic bowel grasper (robotic arm 2) and delivered out of the pelvis, placing the rectosigmoid mesocolon on tension. The bowel is passed from arm 2 to 1 and is retracted anterolaterally, allowing arms 2 and 4 to be used as the two working instruments (movie 1). The right lateral superior pelvic peritoneal reflection (gutter) is incised with monopolar electrocautery starting inferior to the sacral promontory and continuing superiorly to the inferior mesenteric artery (IMA). This allows entry between the mesocolon and retroperitoneum. Dissection continues in a medial-to-lateral approach to the left lateral peritoneal reflection while sweeping the superior rectal artery anteriorly and superior hypogastric nerves posteriorly. The left ureter and gonadal vessels are identified and swept down with the retroperitoneal plane (movie 2). If unable to access from a medial-to-lateral approach, mobilization in a lateral-to-medial orientation can also be performed.

Left ureter identification (with video) — Intraureteral indocyanine green (ICG) is an effective adjunct for ureteral identification during robotic-assisted surgery, especially for procedures where the anatomical planes can be significantly distorted. Using a 22 French (Fr) rigid cystoscope, a 5 Fr open-ended ureteral catheter is inserted up to 20 cm. A total of 5 mL of 2.5 mg/mL ICG is gently injected as the ureteral catheter is withdrawn to the ureteral orifice. No stent is left in place. Intraureteral ICG is detected using robotic near-infrared laser fluorescence technology (Firefly) (movie 3).

Inferior mesenteric artery division (with video) — Depending on the indication for surgery (oncologic or benign pathology), high ligation of the IMA, or its branches, may or may not be necessary. If necessary, the takeoff of the IMA from the aorta is circumferentially dissected, taking great care not to injure the lumbar sympathetic (L1 to L3) and superior hypogastric nerves. Multiple modalities can be used to ligate the IMA and its branches, including staplers, clips, sutures, and vessel-sealing energy devices. We utilize the da Vinci EndoWrist One Vessel Sealer (movie 4 and movie 2).

Inferior mesenteric vein division (with video) — The dissection continues between the avascular plane of the retroperitoneum and mesocolon in a medial-to-lateral orientation working anterior to Gerota's fascia and toward the splenic flexure and inferior mesenteric vein (IMV). The mesocolon is dissected free from the retroperitoneum up to the level of the IMV, ligament of Treitz/duodenum, body of the pancreas, and spleen. If length for a tension-free anastomosis is necessary, the IMV can be ligated cephalad to the left colonic venous tributary and the splenic flexure mobilized (movie 5).

Splenic flexure mobilization (with video) — Full splenic flexure mobilization often requires repositioning the robotic boom and moving the patient out of the Trendelenburg position. One approach for mobilization of the splenic flexure entails entering the lesser sac by elevating the transverse mesocolon off the retroperitoneum anterior to the body/tail of the pancreas and lateral to the duodenum/ligament of Treitz. The greater omentum is then disconnected from the transverse colon starting around the level of the falciform ligament and working from a medial-to-lateral orientation toward the spleen. This allows entry into the previously entered lesser sac. Mobilization continues until all that remains is the lateral peritoneal reflection holding the mobilized left colon in place. This is divided, allowing entry into the previous medial-to-lateral dissection plane and complete mobilization of the left colon. Often mobilization of the splenic flexure requires a combination of approaches (medial to lateral, lateral to medial, superior to inferior, inferior to superior), especially for high-riding flexures (movie 6).

Colon transection and anvil insertion (with video) — Points of transection proximal and distal to the pathology of interest are chosen. The underlying mesocolon is ligated with the EndoWrist One Vessel Sealer up to the level of the bowel wall. For an intracorporeal anastomosis, the bowel is transected distally using the da Vinci EndoWrist 30, 45, or 60 mm stapler. An antimesenteric colotomy large enough to allow entry of an EEA anvil is created distal to the point of proximal transection. The anvil is passed intra-abdominally through the Pfannenstiel incision wound protector. Approximately 2 cm proximal to the proximal point of transection, a small pinpoint colotomy is created as an exit point for the anvil post. Manipulation of the anvil is easiest using a robotic needle driver. After the anvil has been introduced and appropriately positioned, the distal colotomy is closed with a running barbed suture. The bowel is then transected with the da Vinci EndoWrist 45 or 60 mm stapler distal to the anvil at the proximal point of transection. Alternatively, the anvil head can be placed into the bowel first, and the anvil post pulled through the transverse staple line (movie 7).

For oncologic resections, margins of at least 5 cm must be obtained from the cancer. When opening the bowel to insert the anvil, one must avoid manipulating the tumor. The colotomy should be made close to the proximal margin so that the anvil can be positioned farthest away from the cancer.

EEA-stapled anastomosis (with video) — The specimen is moved out of the way and the EEA stapler advanced to the end of the rectal stump. The stapler is opened, allowing the spike to penetrate the antimesenteric side of the bowel/advance through the transverse staple line. The spike and anvil are mated together, and the stapler is sequentially tightened until completely closed. Following firing and removal of the EEA stapler, direct visualization of the anastomosis and an air leak test are concomitantly completed (movie 8).

Closure — The robot is moved out of the way, and the fascia at the 12 mm robotic trocar site is closed laparoscopically using a suture passer device. Alternatively, it can be closed in an open fashion, especially in thinner patients where visualization of the fascia is not an issue. The specimen is then removed through the Pfannenstiel incision. Finally, the trocars and the wound protector are removed and incisions closed (picture 2).

Laparoscopic/robotic proctectomy

Setup and uterine retraction (with video) — Following mobilization of the left colon and splenic flexure and IMV transection if necessary for reach, the patient is placed in a Trendelenburg position. The greater omentum is placed over the stomach, and the small intestine is reflected cephalad to provide an unobstructed view of the pelvis. In females, it may be necessary to suspend the uterus. A Prolene suture on a straight Keith needle can be placed around the round ligaments to hold the uterus against the anterior abdominal wall. Alternative approaches include placing a suture directly through the fundus or using a uterine manipulator transvaginally, which can also assist with dissecting the rectovaginal septum (movie 9).

Total mesorectal excision and rectal transection (with video) — Arm 1 is used for stationary rectal retraction, arm 2 for controlled retraction/countertraction, and arm 4 for dissection (figure 3). The presacral space is entered, and the dissection is continued caudally toward the levator muscles, taking care not to disrupt the fascia propria surrounding the mesorectum. The right lateral stalk is ligated with electrocautery, taking care not to progress too far laterally and risk injury to the parasympathetic nervi erigentes (S2 to S4). During the dissection, if larger crossing vessels are found in the lateral stalks, bipolar electrocautery can seal them. Exchanging robotic instruments between arms 4 (monopolar curved scissors) and 2 (fenestrated bipolar forceps) will decrease issues with crossover and make the transection of the left lateral stalk easier. Lastly, the anterior dissection is completed. An assistant retracts the rectum cephalad through the assistant trocar, allowing arm 1 to be used to elevate the genitourinary structures/vagina anteriorly, exposing the rectovesical/rectovaginal space. Arm 2 is used to push the rectum posteriorly, providing countertraction to continue dissecting posterior to the Denonvilliers fascia to the level of the pelvic floor. The total mesorectal excision is continued to the pelvic floor, and the rectum is transected using the da Vinci EndoWrist 45 mm stapler with a green load staple cartridge (movie 10).

After distal transection, an intracorporeal anastomosis and the remainder of the surgery are completed as described above in the laparoscopic/robotic left/sigmoid colectomy section. (See 'Colon transection and anvil insertion (with video)' above and 'EEA-stapled anastomosis (with video)' above and 'Closure' above.)

Transanal total mesorectal excision (investigational technique) — Transanal total mesorectal excision (TaTME) is an emerging modality utilized for rectal surgery. Referred to as the bottom-up approach to a proctectomy, it is purported to decrease issues with coning in with the total mesorectal excision (TME), allow for more accurate identification of the distal margin of resection, increase rates of sphincter preservation, reduce wound-related complications (infection, incisional hernia), reduce sexual and urinary dysfunction, avoid intracorporeal stapling, and allow two operative teams to work simultaneously (perineal and abdominal) to shorten operative time. In addition, it is noted to be most beneficial in patients with a narrow pelvis and significant visceral obesity [12].

Limitations to TaTME include the inability to visualize the intracoelomic cavity completely, transect the inferior mesenteric artery in an oncologic high ligation fashion, transect the marginal artery, mobilize proximally (splenic flexure), and ligate the inferior mesenteric vein. Reported complications unique to TaTME include bleeding and nerve damage secondary to injury of the neurovascular bundle of Walsh and pre-prostatic urethral injuries [13,14]. Surgeons not familiar with this technique need standardized training, including observations, cadaveric labs/hands-on courses, and proctorship/mentorship with early case experiences [15-17]. Experts have recommended starting in females with benign disease without prior pelvic sepsis or radiation [18].

There are minimal randomized and multicenter controlled trials comparing TaTME to other surgical techniques [19,20]. Studies to date include mostly heterogeneous single-center series [21,22]. Data on complications and short-term oncological outcomes appear favorable [23], although some studies have found high anastomotic leak rates and local recurrence rates [24]. Long-term outcomes are heterogeneous, with some showing increased recurrence rates while others report the opposite [25,26]. The safety of TaTME will continue to be debated, and TaTME for rectal cancer should be limited to appropriately designed trials and experts in high-volume centers until high‐quality evidence from randomized controlled trials is obtained (eg, COLOR III). (See "Radical resection of rectal cancer", section on 'Transanal TME'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Colorectal cancer" and "Society guideline links: Colorectal surgery for cancer" and "Society guideline links: Laparoscopic and robotic surgery".)

SUMMARY

●Minimally invasive colorectal resection techniques are feasible and result in earlier tolerance of diet, accelerated return of bowel function, lower analgesic requirements, and shorter length of hospital stay.

●While large multicenter randomized trials comparing open and laparoscopic approaches for colon cancer have shown comparable disease-free or overall survival, the safety profile and long-term outcomes for minimally invasive oncologic rectal resections need further study. Thus, minimally invasive surgery for rectal cancer should be limited to appropriately designed trials and experts in high-volume centers.

●The authors' techniques for left/sigmoid colectomy and proctectomy are described and illustrated in this topic. However, they should not be regarded as the only viable techniques for these purposes. (See 'Operative approach' above.)