Hand-assisted right colectomy

♦ Familiarity with the vascular anatomy of the right colon is essential to the safe conduct of a minimally invasive right colectomy (Figure 20-1). Vascular anatomy also significantly determines resection of colonic malignancies. Several key points guide the laparoscopic surgeon:

Venous and lymphatic drainage run in tandem with named mesenteric arteries.

The ileocolic artery (ICA) branches from the superior mesenteric artery (SMA) just over the duodenum after the take-off of the middle colic artery (MCA). It courses obliquely through the mesocolon to terminate at the cecum, giving off a terminal ileal branch that joins with the small bowel arcade from the SMA.

The right colic artery is usually a branch of the ICA rather than arising from the SMA as is historically depicted.

The MCA proper is typically quite short, branching into two or more arteries (right branch, left branch) just 1 to 2 cm from the aortic origin of the SMA. Rarely is the main MCA itself divided in colon resections. The significant hazard of attempts to control bleeding from a transected main MCA is injury to the SMA.

The branches of the MCA are most easily identified from the cranial aspect of the proximal transverse mesocolon. Once these branches and the adjacent mesocolon are transected, the origin of the ICA can be seen retroperitoneally, as can the more medially oriented SMA.

♦ The embryologic fusion plane originates laterally at the white line of Toldt, which occurs where the parietal peritoneum fuses with the visceral peritoneal reflection around the colon and its lateral extension (Figure 20-2). The correct dissection plane is the bloodless embryologic fusion plane. When properly mobilized in this plane, the colon reflects medially on its mesentery to become a nearly midline structure. When the dissection is carried posteriorly past the white line of Toldt, violating the parietal peritoneum as it extends across the retroperitoneal structures, the ureter and gonadal vessels are put at risk and mobilization of the colon is limited.

♦ Awareness of the relationships between the cecum, ascending colon, hepatic flexure, and proximal transverse colon to neighboring structures helps to maintain orientation during surgery and prevents injury:

The duodenal sweep can be appreciated medial and caudal to the hepatic flexure mesocolon. Risk of injury to the portal triad can be averted by avoiding performance of a Kocher maneuver.

The right kidney and Gerota’s fascia are just lateral to the distal ascending colon. Dissection lateral to the embryologic fusion plane can lead to mobilization of the kidney or the second portion of the duodenum (Kocher maneuver).

The right ureter descends retroperitoneally and is not typically exposed unless dissection is carried posterior to the embryologic fusion plane.

The lesser sac must be entered in order to take down the hepatic flexure and transect the transverse mesocolon and MCA branches. The stomach, the gastrocolic, and the hepatocolic ligaments constitute its anterior boundary. Posteriorly, one finds the pancreas and, to the right, the duodenal sweep.

The liver and gallbladder are superior to the hepatocolic ligament. Failure to appreciate this plane can lead to dissection of the porta hepatis.

♦ Surface anatomy considerations principally help with optimal port placement:

Preoperative knowledge of a redundant transverse colon would suggest more caudal placement of the periumbilical hand port incision.

A shift of the hand port site superiorly helps in patients with a relatively long distance between the xiphoid and the umbilicus.

♦ Access and port placement:

The hand port template is used to demarcate the incision length, which should be no larger than the surgeon’s glove size (e.g., size 7 glove would require a 6- to 7-cm hand port incision).

The hand port incision is centered on the point that is half way between the anterior superior iliac crest and the costal margin. The incision may be quite a bit above the umbilicus in an obese patient.

The hand port incision is made first, and the hand-assist device is placed.

A 12-mm port is advanced through the hand port for insufflation (15 mmHg).

Two additional ports (5 mm each) are placed. The subxiphoid port is placed just to the left of the midline (farther left if an extended right hemicolectomy is anticipated). The left upper quadrant port is placed at the midclavicular line, halving the distance between the costal margin and the superior end of the hand port incision (Figure 20-4).

♦ Abdominal survey:

Mobilize the falciform ligament if it interferes with the subxiphoid port.

Evaluate the liver and peritoneum for metastases in a cancer resection.

Identify the target lesion.

♦ Mobilization of the colon:

This is a top down approach. The anatomy is viewed from above and the dissection moves from the right upper quadrant to the right lower quadrant. Mobilization of the anatomy involves lifting the bowel and its mesentery up off of the retroperitoneum.

Mobilization of the colon begins in the lesser sac. First, we divide the gastrocolic and hepatocolic ligaments to enter the lesser sac and expose the ventral surface of the transverse mesocolon.

The duodenal sweep and hepatic flexure will come into view laterally.

As the dissection is carried to the patient’s right, Gerota’s fascia also comes into view.

Leave the lateral attachments in place initially and expose the rest of the duodenum first by dividing filmy attachments between the ascending mesocolon and duodenum.

Divide the lateral attachments of the right colon, carrying the dissection medially along the embryologic fusion plane. Failure to dissect in this avascular plane will result in exposure of the right psoas muscle, ureter, and gonadal vessels. Alternatively, the right kidney may be mobilized or a Kocher maneuver may inadvertently be performed.

Eventually, the entire right colon and ileal mesentery will be elevated off of the retroperitoneum, leaving only the embryologic attachments of the small bowel mesentery attached from the right lower quadrant up to the duodenum. Finally, with the ileal mesentery and small bowel draped into the left lower quadrant, incise the peritoneum at the base of the ileal mesentery from the right lower quadrant back up to the duodenum/ligament of Trietz. This will later allow the ileum to easily come up into the wound for exteriorization and anastomosis. specimen and performing the extracorporeal anastomosis.

♦ The lymphovascular pedicles are identified and divided (Figure 20-5):

Find the middle colic vessels near their origin by holding the transverse colon in the palm, elevate it, and use the index finger and thumb to palpate the base of the transverse mesocolon. One or more branches of the MCA will be divided depending on the extent of the resection. A bipolar vessel sealing (device can be used to divide the mesentery and vessels just caudal to the pancreas. Leave a stump of vessel behind in case there is bleeding so that a vascular load of a stapler Endostapler or an Endoloop can be applied.

Identify the ileocolic artery sharply to the left of the line of MCA middle colic artery transection.

Confirm the identity of the ICA iliocolic artery:

If the vessels are highly calcified, use a vascular load of the laparoscopic stapler.

Divide the mesentery from the junction of the ICA and SMA to the marginal artery along the ileum.

♦ Desufflate the abdomen through the ports. This is particularly important in cancer resections to avoid seeding port sites with aerosolized tumor cells.

♦ Exteriorize the right colon through the gel port:

Divide the ileum and the transverse colon externally using a handheld linear cutting stapler.

♦ Perform an ileocolic anastomosis. This can be done as for conventional open resections. Take care to avoid twisting the ileum, especially if it was divided intracorporally. Return bowel to the abdomen.

♦ Examine the specimen to be sure the target lesion is in the specimen.

♦ Close the incisions. No fascial closure is required for the 5-mm ports. Close the skin with a 4-0 absorbable deep dermal running suture followed by application of a wound sealant.

♦ A fast-track plan is encouraged.

♦ Analgesia. A PCA pump or Toradol with intermittent parenteral narcotics can be used, transitioning promptly to oral analgesics once solid food is started.

♦ Nasogastric tube. This is not routinely used unless there is extensive lysis of adhesions.

♦ Diet. Clear liquids are offered on postoperative day 1 and a soft diet on postoperative day 2 unless the patient has nausea, vomiting, distention, or significant belching.

♦ Urinary catheter. This is removed on postoperative day 1 or 2.

♦ Activity. The patient is encouraged to sit or stand at the bedside the day of surgery and to sit in a chair the morning following surgery. Ambulation is ordered on postoperative day 1.

♦ Discharge. The patient can be discharged once a diet is tolerated and bowel function has resumed. This usually happens by postoperative day 3 to 5.

♦ The learning curve for laparoscopic colon resection can be shortened by utilizing the hand-assisted approach:

It is estimated that one must perform 25 to 50 pure laparoscopic colon resections to become proficient.

Hand-assisted laparoscopic surgery (HALS) allows the surgeon to work with less experienced staff. Bowel retraction and vessel identification and division (especially of the middle colic artery) are easier.

♦ The goal of the operation is to perform a safe operation (and a curative operation in the setting of cancer). Patients need a good operation, not necessarily a laparoscopic one.

♦ A periumbilical hand port incision is preferred to a Pfannenstiel incision for several reasons.

♦ Mobilization of the mesocolon around the duodenum should involve gentle, posterior displacement of the duodenum. Care should be taken to avoid mobilization of the duodenum (the Kocher maneuver) to avoid exposure of the porta hepatis and risk of injury to those structures.

♦ Avoid the temptation to ligate the vascular pedicles extracorporally. It’s never possible to reach the mesentery well once bowel is exteriorized, and it’s harder to control bleeding.

♦ Taking at least one branch of the middle colic artery helps assure good length of exteriorized transverse colon and avoid traction injury of the middle colic artery when exteriorizing the bowel.

♦ Leave a short stump of vessel behind when dividing vessels with a vessel sealing and cutting device.

♦ Adhesions in the lesser sac (fusion of the gastrocolic or hepatocolic ligaments with the retroperitoneum or adhesions between the posterior stomach and retroperitoneum) can interfere with adequate exposure of the transverse mesocolon and safe identification of the middle colic artery.

♦ Hand-assisted laparoscopic surgery is still image-based surgery. The hand is a sophisticated retraction device.

♦ This procedure safely handles bowel and protects it from the power source.

♦ Manipulation can thin tissue and help identify vessels.

♦ Typically, the index finger leads the way, the next three fingers provide retraction, and the thumb provides countertraction.