Laparoscopic Right Colectomy (Right Hemicolectomy)

Laparoscopy has emerged as the preferred operative approach for most intra-abdominal pathologic conditions. Nonetheless, even though the first laparoscopic colectomy was reported decades ago, the majority of colectomies in the United States are still being performed via the open approach.

This delay in acceptance has mainly been attributable to initial concerns regarding the adequacy of oncologic margins and trocar site recurrences believed to occur with laparoscopy—concerns now largely laid to rest by the results of large randomized controlled trials such as the Clinical Outcomes of Surgical Therapy (COST) trial. ^[1]  Minimally invasive colectomy has been growing in popularity. ^[2]

The benefits of laparoscopic hemicolectomy include the following:

• Smaller wounds and improved cosmesis
• Shorter hospital stay
• Less postoperative pain
• Earlier return to normal activity
• Quicker recovery of pulmonary function
• Lower incidence and quicker resolution of postoperative ileus
• Lower incidence of surgical site complications
• Lower incidence of postoperative adhesions ^[3]

The goals of laparoscopic right hemicolectomy (right colectomy) performed in the setting of colon cancer are the same as those of the equivalent open procedure. They involve appropriate vessel ligation, creation of sufficient luminal margins, and adequate lymph node sampling. In addition, a thorough inspection of the abdominal cavity and liver surface is expected, together with the creation of a reliable anastomosis.

Laparoscopic colectomy for resectable colon cancer has been reported to be technically and oncologically feasible. The general consensus, based on the literature over the past several years, is that there is no significant difference in lymph node harvest between laparoscopic and open right hemicolectomies for cancer when strict oncologic principles of resection are followed. To date, patient survival, disease progression, and cancer recurrence at port sites have been found to be equivalent between laparoscopic colectomy and traditional open colectomy.

Several short-term benefits similar to those described for colon cancer have been associated with laparoscopic segmental colon resection for inflammatory bowel disease (IBD). In addition, theoretical long-term advantages include formation of fewer adhesions, decreased rates of bowel obstruction, decreased likelihood of chronic pain, and decreased incidence of infertility or wound hernias. Two randomized controlled trials demonstrated some short-term benefits to laparoscopic ileocolic resection for Crohn disease. On the other hand, evidence on laparoscopic surgery for ulcerative colitis has not supported its routine use among nonexpert surgeons outside of specialized centers.

Laparoscopic colonic resection for diverticular disease appears to provide several short-term benefits, though these advantages may not translate to cases of complicated diverticulitis.

The indications for laparoscopic right hemicolectomy are similar to those for open right hemicolectomy, as follows:

• Adenomatous polyps not amenable to colonoscopic resection
• Crohn disease and its complications
• Bleeding secondary to diverticulosis or arteriovenous malformation
• Diverticulitis
• Obstruction
• Colon tumors (benign or malignant)

There are few contraindications for laparoscopic right hemicolectomy.

Absolute contraindications include the following:

• Tumor infiltration into adjacent structures (T4)
• Large phlegmonous mass
• Obstruction, perforation, or ileus leading to massive bowel distention and loss of domain
• Carcinomatosis

Relative contraindications (depending on local expertise) include the following:

• Morbid obesity
• Multiple previous abdominal surgical procedures
• Extensive abdominal adhesions
• Primary tumor with resectable liver metastasis ^[4]

Laparoscopic right colectomy for a neoplasm was not associated with a higher conversion rate or higher morbidity in patients with prior abdominal surgery; therefore, prior abdominal surgery is not a contraindication for laparoscopic right colectomy. ^[5]

Indications for conversion to open surgery in the COST trial included the following ^[1] :

• Extensive abdominal adhesions
• Inability for the surgeon to mobilize and define the tumor extent
• Resectable metastases

Ultimately, the method of resection (laparoscopic vs open) cannot compromise the oncologic adequacy of resection, which is why a very well-defined stepwise technique is so vital.

Anatomy

The right colon is derived embryologically from the endoderm roof of the yolk sac, which develops into the primitive gut tube. In the beginning of the week 3 of gestation, the gut tube separates into the midgut, foregut, and hindgut segments. The midgut gives rise to the segment of the gastrointestinal (GI) tract extending from the distal duodenum to the distal transverse colon. ^[6] It derives its blood supply from the superior mesenteric artery (SMA).

The terminal ileum empties into the cecum through the ileocecal valve. The cecum measures approximately 7.5 cm in diameter and 10 cm in length. The appendix extends from the cecum and measures 8-10 cm in length. The ascending colon is 15 cm long. The posterior surface is fixed against the retroperitoneum along the white line of Toldt. The lateral and anterior surfaces are intraperitoneal. The transverse colon is 45 cm in length. It is fixed by the nephrocolic ligament at the hepatic flexure and by the phrenocolic ligament at the splenic flexure. It is completely invested in visceral peritoneum.

The colon has specific characteristics that distinguish it from other parts of the GI tract. The omental appendices are bodies of fat enclosed by peritoneum. The taeniae coli are three bands of longitudinal muscle; haustra form between the bands.

All vascular structures and lymph nodes are located in the mesocolon. It is easiest to visualize the colon mesentery as being no different from the small-bowel mesentery. Both mesenteries attach at a 90º angle and contain arterial, venous, and lymphatic channels. The right colon differs from small bowel only in that the bowel and its mesentery are "plastic-wrapped" to the retroperitoneum. This distinction is important because in order to resect this bowel, the colon and its mesentery must first be mobilized from its retroperitoneal attachments; only then can a segmental resection with lymphadenectomy be performed.

The arterial supply branches from the SMA to the ileocolic, right colic, and middle colic arteries. The SMA territory ends at the distal transverse colon, where the inferior mesenteric artery (IMA) takes over to supply the left colon. A marginal artery network is the anastomotic web between these vessels along the mesenteric border. Vasa recta branches of the marginal artery directly supply the bowel wall.

The most common pattern of arterial supply relevant to a right hemicolectomy consists of the three arterial branches arising from the SMA (ileocolic artery, right colic artery, and middle colic artery). The ileocolic artery, the most constant tributary of the SMA, supplies the terminal ileum, cecum, and appendix. The right colic artery supplies the ascending colon and hepatic flexure of the transverse colon. (See the image below.)

The middle colic artery is the most proximal branch of the SMA, supplying the proximal and distal transverse colon via the right and left branches. The middle colic artery is completely absent in as many as 25% of individuals; it is replaced by a large right colic artery. ^[7] The arc of Riolan (meandering mesenteric artery) is a collateral artery that directly connects the proximal SMA to the proximal IMA and may serve as a vital conduit when arterial occlusion occurs.

Many variations of the right colic artery anatomy exist (see the image below). It arises directly from the SMA in approximately 40% of individuals, from the middle colic artery in 30%, and from the ileocolic artery in 12%. It is completely absent in 20% of individuals.

Venous drainage mimics the arterial tree, with ileocolic and right colic veins draining into the superior mesenteric vein (SMV). The lymphatic drainage follows the arteries and drains into the para-aortic nodal chain. Other lymph nodes involved include epicolic nodes along the bowel wall, paracolic nodes adjacent to the marginal artery, intermediate nodes along the arterial and venous branches, and primary nodes at the SMA and SMV. ^{[8, 9]}

Relevant definitions and terminology

The Gerota fascia is a perinephric fascia that encloses the kidneys and adrenal glands. Superiorly, it tapers over the inferior diaphragmatic surface. Medially, the fascia crosses the midline and is contiguous with the contralateral fascia. Laterally, the Gerota fascia is an open potential space that contains the ureter and gonadal vessels.

The white line of Toldt represents the fusion of colic mesentery with the posterior peritoneum.

An adenomatous polyp is a mass projecting into the lumen of the bowel. These polyps are classified by their gross appearance as pedunculated or sessile and further classified by histology as tubular or villous. The most common colonic polyp is a tubular adenoma. The incidence of carcinoma in a polyp depends on size and histology.

Diverticulosis describes the presence of colonic diverticula. A diverticulum is an abnormal protrusion of mucosa through the muscular layers of the colonic wall. Diverticula are associated with increasing age and low-fiber diets. ^[9]

Complication prevention

Because of the close proximity of the duodenal sweep to the ileocolic pedicle, the duodenum is at risk for sharp or cauterization injuries. To prevent such injury, the duodenum should be identified and gently swept away prior to dissection and division of the ileocolic pedicle.

The right ureter is most commonly injured over the right iliac vessels during cecal mobilization; accordingly, care should be taken to ensure that the dissection plane is not overly posterior. As a rule, the ureter should remain underneath the Toldt retroperitoneal fascia. However, if the Toldt fascia cannot be clearly visualized via a medial approach and the dissection plane is unclear during the isolation of the ileocolic pedicle, it is advisable to switch to an inferior approach. The ileum is mobilized off the retroperitoneum so that the right ureter can be identified and traced toward the duodenum before the pedicle is divided. ^[3]

Aggressive blunt dissection around the origin of the ileocolic vein makes the SMV susceptible to avulsion injury. A short stump should be left during ligation of the ileocolic pedicle in order to avoid encroachment into the superior mesenteric vessels. ^[3]

Aberrant anatomy must be taken into account. In 10%-30% of cases, an additional right colic vein arises from the ascending colon and drains into the SMV below the third portion of the duodenum.

In some patients, fusion of Gerota fat to the posterior aspect of colon can increase the risk of either entering Gerota fat or dissecting posterior to the kidney during lateral mobilization. This problem is prevented by pushing down on Toldt retroperitoneal fascia and ensuring that the dissection planes remain anterior to it.

Proximal ligation of the right colic vein places the right gastroepiploic vein at risk for injury or division. This type of injury is prevented by lifting the transverse colon anteriorly and dividing only the veins that travel to the colon. The vasculature traveling underneath the colon toward the stomach is preserved. ^[3]

During anastomosis, the terminal ileum or the transverse colon may become twisted around its mesentery. Often, the twisting is not visible through the minilaparotomy incision and consequently goes unnoticed. To prevent this complication, place two seromuscular stay sutures into the ileum, one proximal and one distal, after the right colon is exteriorized and the terminal ileum and mesentery divided. These stay sutures are clamped individually and are never crossed. Another technique involves placing a laparoscopic grasper on the terminal ileum. Once the anastomosis has been created, a final look through the laparoscope can confirm that the mesenteric orientation is correct. ^[3]

The average mortality following laparoscopic colorectal surgery is less than 2%. A randomized trial by Lacy et al reported that perioperative mortality was 1% for laparoscopic resection and 3% for open resection. ^[10]

The COST Study Group evaluated laparoscopic resections used to treat colorectal cancer in the United States. The study concluded that cancer recurrence rates were similar between the laparoscopically assisted colectomy and open colectomy groups, suggesting that the laparoscopic approach is an equivalent alternative to open surgery for colon cancer. ^[1]

A systematic review and meta-analysis by Arezzo et al, which examined the safety and oncologic adequacy of laparoscopic right colectomy against those of open right colectomy in 3049 rectal cancer patients, found that morbidity and mortality were significantly lower with the laparoscopic technique. ^[11]

From 2009 to 2010, Yun et al analyzed 159 patients with colon cancer who underwent single-incision laparoscopic right colectomy. They concluded that the procedure is safe and can provide outcomes equal to those of conventional laparoscopic colectomy. ^[12]  These findings were supported in a study by Pedraza et al. ^[13] ​

In a systematic review and meta-analysis that included 11 studies (N = 8257), Solaini et al compared the safety of robotic right colectomy with that of laparoscopic right colectomy. ^[14] Operating time was significantly shorter for the laparoscopic procedures, and conversion to open surgery was more common in this setting as well. There were no significant differences in mortality or postoperative complications between the laparoscopic and robotic approaches. The pooled mean time to first flatus was greater with laparoscopic procedures. Hospital costs were significantly higher for robotic procedures.

Shorter hospitalization and fewer postoperative complications might be expected to reduce overall procedural costs, but these can be offset by the increased cost of longer operating times and more costly instrumentation. Bouvet et al found similar total hospital charges when comparing laparoscopy versus laparotomy for colectomy. ^[15] Likewise, Philipson et al did not show any cost benefit of laparoscopic-assisted right hemicolectomies compared with the open technique. ^[16]

In a retrospective study using data from a population-based database, however, Wei et al found that minimally invasive (ie, laparoscopic or robotic) colectomy, as compared with open colectomy, was associated not only with a significantly lower risk of major perioperative complications but also with lower total hospital costs, despite the longer operating times. ^[2]