Laparoscopic Low Anterior Resection
KEY STEPS
1. Insertion of ports: 10-mm umbilical Hasson technique; 12-mm at ostomy site right iliac fossa; 5-mm right upper quadrant; 5-mm left iliac fossa.
2. Patient rotated to the right and steep Trendelenburg.
3. Greater omentum reflected over the transverse colon and the small bowel moved to right upper quadrant.
4. Inferior mesenteric artery (IMA) pedicle identified and dissected. Left ureter identified and IMA divided with high ligation, proximal to the left colic artery.
5. Medial-to-lateral mobilization of the left colon and division of inferior mesenteric vein close to the tail of pancreas.
6. Lateral paracolic mobilization of the left colon toward the splenic flexure.
7. Splenic flexure mobilization.
8. Rectal mobilization. Dissection behind mesorectum in presacral space.
9. Division of peritoneal attachments on the right and left sides of the mesorectum, and anterior mobilization beginning just anterior to the peritoneal reflection.
10. Rectum mobilized to anal canal and divided, after ensuring adequate distal margin.
11. Specimen extracted through keyhole incision at ileostomy site, using a wound protector, for extracorporeal resection and stapled coloanal anastomosis.
12. Formation of right iliac fossa trephine loop ileostomy.
13. Closure of ports >5-mm in size.
ADDITIONAL ADVICE
1. The right-sided ports are placed closer to the midline than in a standard sigmoid colectomy facilitating access to, and dissection in, the lower pelvis.
2. If it is difficult to find the presacral space on the right side, consider going to a lateral mobilization of the sigmoid before risking nerve or other injury.
3. Making a long incision in the peritoneum to mobilize a long segment of IMA facilitates safe identification of the presacral space and protection of nerves and the ureter.
4. It is often easier to enter the presacral space just inferior to the sacral promontory, and then work back “proximally” toward the origin of the IMA.
5. Once the IMA and vein are divided, mobilize as much of the descending mesocolon as possible from the medial approach, to facilitate later lateral dissection.
6. When performing the lateral mobilization of the sigmoid colon, draw the colon medially and anteriorly to display the space behind the sigmoid and its mesentery, which has already been dissected with the medial dissection.
7. Mobilize the splenic flexure and any additional transverse colon mesentery necessary at this stage, to avoid potentially compromising blood flow after exteriorizing the specimen, as it is difficult to assess blood flow once the anvil is positioned and the bowel is returned to the abdomen.
8. Commence the mesorectal dissection posteriorly, using firm anterior and superior retraction of the rectosigmoid to place the loose areolar tissue under tension and facilitate dissection.
9. Firmly pulling the mesentery superiorly, as well as medially away from the lateral pelvic sidewall, facilitates the lateral dissection.
10. The anterior dissection is commenced 1 or 2-mm anterior to the apex of the pouch of Douglas. This enters the correct anatomical plane, keeping the anterior mesorectal fascia intact.
11. Dissection is completed within the anal canal, after seeing the levators curve down into the anal canal, and after confirming an adequate distal margin by digital rectal examination, or endoscopy.
12. Division at the anorectal junction can often be completed with one 45-mm stapler cartridge; however, a second cartridge may be required to divide a final 5 to 10-mm of the rectum. It is important to apply the second cartridge precisely such that the completed distal staple line looks like a single transverse staple line.
13. After resecting the specimen and placing the anvil for anastomosis, the proximal bowel is returned to the abdomen and the ostomy site temporarily closed with the wound protector to facilitate laparoscopy and anastomosis.
PATIENT POSITIONING
The patient is placed supine on the operating table on a bean bag. After induction of general anesthesia and insertion of an orogastric tube and a Foley catheter, the legs are placed in yellow fin stirrups. The arms are tucked at the patient’s side and the bean bag is aspirated. The abdomen is prepared with antiseptic solution and draped routinely (Chapter 2).
INSTRUMENT POSITIONING
The primary monitor is placed on the left side of the patient at approximately the level of the hip. The secondary monitor is placed on the right side of the patient at the same level and is primarily for the assistant during the early phase of the operation and port insertion (see Fig. 20.1). The operating nurse’s instrument table is placed between the patient’s legs. There should be sufficient space to allow the operator to move from either side of the patient to between the patient’s legs if necessary. The primary operating surgeon stands on the right side of the patient with the assistant standing on the patient’s left, and moving to the right side, caudad to the surgeon once ports have been inserted. A 0-degree camera lens is used.
UMBILICAL PORT INSERTION
This is performed using a modified Hasson approach (Chapter 3). A vertical 1-cm subumbilical incision is made. This is deepened down to the linea alba, which is then grasped on each side of the midline using Kocher clamps. Cautery is used to open the fascia between the Kocher clamps and Kelly forceps are used to open the peritoneum bluntly. It is important to keep this opening small (<1-cm) to minimize air leaks. Having confirmed entry into the peritoneal cavity, a purse string of 0 polyglycolic acid is sutured around the subumbilical fascial defect (umbilical port site) and a Rommel tourniquet is applied. A 10-mm reusable port is inserted through this port site allowing the abdomen to be insufflated with CO2 to a pressure of 12 mmHg.
LAPAROSCOPY AND INSERTION OF REMAINING PORTS
The primary operating surgeon stands on the right side of the patient with the assistant standing on the patient’s left. The camera is inserted into the abdomen and an initial laparoscopy is performed carefully evaluating the liver, small bowel, and peritoneal surfaces. A 12-mm port is inserted in the right lower quadrant approximately 6 to 8 cm medial and superior to the anterior superior iliac spine. In patients marked for a temporary ileostomy, the port is placed through this site, paying careful laparoscopic attention to the position of the inferior epigastric vessels to avoid injury. A 5-mm port is then inserted in the right upper quadrant at least a hand’s breadth superior to the lower quadrant port. A 5-mm left lower quadrant (LLQ) port is inserted. A 5-mm left upper quadrant port is rarely required to aid splenic flexure mobilization in very obese patients, or if there has been prior surgery in the area. The left-sided ports are kept lateral to the epigastric vessels (Fig. 20.2).
DEFINITIVE LAPAROSCOPIC SETUP
The assistant moves to the right side of the patient, caudad to the surgeon, once ports have been inserted. The patient is rotated with the left side up and right side down, to approximately 15 to 20 degrees tilt, and often as far as the table can go. This helps to move the small bowel over to the right side of the abdomen. The patient is then placed in the Trendelenburg position. This again helps gravitational migration of the small bowel away from the operative field. The surgeon then inserts two atraumatic bowel clamps through the two right-sided abdominal ports. The greater omentum is reflected over the transverse colon so that it comes to lie on the stomach. If there is no space in the upper part of the abdomen, one must confirm that the orogastric tube is adequately decompressing the stomach of gas. The small bowel is moved to the patient’s right side, allowing visualization of the medial aspect of the rectosigmoid mesentery, and also
placed up under the transverse mesocolon to give room to see the inferior mesenteric vessels (Fig. 20.3). This may necessitate the use of the assistant’s 5-mm atraumatic bowel clamp through the LLQ in order to tent the sigmoid mesentery cephalad.
placed up under the transverse mesocolon to give room to see the inferior mesenteric vessels (Fig. 20.3). This may necessitate the use of the assistant’s 5-mm atraumatic bowel clamp through the LLQ in order to tent the sigmoid mesentery cephalad.