Open Left Colectomy (Left Hemicolectomy)

Updated: Mar 04, 2022
Author: Juan L Poggio, MD, MS, FACS, FASCRS; Chief Editor: Vikram Kate, MBBS, PhD, MS, FACS, FACG, FRCS, FRCS(Edin), FRCS(Glasg), FIMSA, FFST(Ed), MAMS, MASCRS 



Left hemicolectomy (left colectomy) is the surgical removal of the left side of the large bowel (see the first figure below); sigmoid colectomy is the surgical removal of the sigmoid colon (see the second figure below). These operations are mostly performed for cancers of the left colon and sigmoid colon,[1, 2] though they have several other indications, as described later in this article.

Left colectomy. Left colectomy.
Sigmoid colectomy. Sigmoid colectomy.


In most instances, surgical treatment of tumors of the left colon requires a left hemicolectomy. This procedure involves taking the inferior mesenteric blood supply, along with its branches (left colic artery and sigmoid arteries), which supply the splenic flexure to the proximal sigmoid colon. Tumors of the sigmoid colon can be removed by means of a sigmoid resection. This procedure encompasses the distal descending colon and the sigmoid colon, sacrificing the sigmoid and superior rectal arteries.[3, 4, 5]

Indications for left hemicolectomy are as follows:

  • Left-side colon cancer without metastasis
  • Left-side colon cancer with metastasis with complications such as bleeding or obstruction
  • Left colonic malignant polyp (T1 lesion) that, after polypectomy, reveals high-risk pathologic features suggesting a high possibility of lymph node metastasis
  • High-risk premalignant polyps of the left colon that are not amenable to endoscopic polypectomy
  • High-risk benign polyps that are not amenable to endoscopic polypectomy (eg, large tubulovillous adenoma)
  • Carcinoid of the left colon
  • Ischemic colitis
  • Noniatrogenic trauma with perforation (eg, gunshot injury to the abdomen causing colonic perforation)
  • Iatrogenic trauma (eg, perforation during colonoscopy)
  • Lower gastrointestinal bleeding, localized to the left colon
  • Chronic diverticular disease, most commonly of the sigmoid colon
  • Sigmoid volvulus
  • Failure of a laparoscopic approach - In a study by Simorov et al, the laparoscopic-to-open conversion rate was 20.7% for left colectomy and 14.3% for sigmoid colectomy [6]


One contraindication for left colectomy is metastatic colon cancer without complications. In such a case, surgical removal of the colon will not benefit the patient; instead, it will put the patient at risk for surgical complications and cause an unnecessary delay in systemic chemotherapy.

A second contraindication is surgically curable colon cancer in patients with severe medical comorbidities and/or those who are unstable and critically ill. Such patients cannot tolerate a major surgical procedure requiring general anesthesia.

Technical Considerations


The left colon begins at the midtransverse colon and includes the splenic flexure, the left (descending) colon, and sigmoid colon. The midcolon and the distal transverse colon are covered by peritoneum, and they are relatively mobile, except for the splenic flexure (because of the presence of the splenocolic ligament).

The descending colon is covered by peritoneum on the anterior and lateral surfaces and attaches to the retroperitoneum on the posterior side. The sigmoid colon is completely covered by peritoneum and is attached to the abdominal wall by a lateral peritoneal attachment termed the white line of Toldt, which extends upward to include attachment of the left colon as well.

Structures beneath the descending colon include the left kidney, the proximal ureter, and the inferior mesenteric vein (IMV). The intersigmoid fossa is a recess at the base of the mesosigmoid that provides an anatomic landmark for locating the left ureter, which courses beneath the fossa and runs parallel and just medial to the gonadal vein. Mobilization of the flexure requires division of the splenocolic ligament, a maneuver that must be performed carefully to prevent splenic capsular tearing.

Embryologically, the blood supply of the left colon is from the inferior mesenteric artery (IMA). The marginal artery of Drummond provides a vascular anastomosis between the superior mesenteric artery (SMA) and the IMA. In general, the distal transverse colon, including the splenic flexure and the descending colon, is supplied by the left branch of the middle colic artery, which is a branch of the SMA. The rest of the left colon is supplied by branches of the IMA.

The vascular supply of the sigmoid colon comes from the IMA and its sigmoidal and superior rectal artery branches. Collateral flow is provided by the marginal arteries and the arc of Riolan, a meandering artery from the middle colic artery to the IMA. Venous drainage is via the IMV, which joins the splenic vein and the superior mesenteric vein (SMV) to form the portal vein.

The lymphatic drainage follows the arterial supply. Since the main route of spread of carcinoma of the colon is via the lymphatics, an oncologic resection includes resection of the draining lymph nodes along with the lesion.

The superior hypogastric plexus is situated at the bifurcation of the aorta in close proximity to the IMA pedicle, and it provides sympathetic innervation for erectile function. Retrograde ejaculation in male patients can occur if care is not taken to avoid division of the nerve fibers during high IMA ligation and division.[3, 4, 5]

For more information about the relevant anatomy, see Colon Anatomy, Large Intestine Anatomy, Lower GI Tract Anatomy, and Liver Anatomy.


Periprocedural Care

Preprocedural Planning

A thorough history and physical examination are essential. Special emphasis should be placed on cardiopulmonary status so as to optimize the patient;s condition for tolerating surgical stress. A complete preoperative workup should be performed in order to establish the stage of the cancer. This includes, at a minimum, computed tomography (CT) of the abdomen and pelvis and radiography of the chest. A carcinoembryonic antigen (CEA) level is ordered for colon cancer at the time of diagnosis.

If the colonic lesion was diagnosed via flexible sigmoidoscopy, a full colonoscopy is essential to evaluate for synchronous lesions, and all lesions should be tattooed so that they can be identified at the time of surgery. Patient counseling about the risks and complications of the surgery, including the possibility of creating an ostomy, should be performed.

Mechanical bowel preparation is started the day before the operation to clear the bowel of fecal material, which would otherwise make it difficult to manipulate the colon during surgery.[7]  In a retrospective series on mechanical and oral antibiotic bowel preparation Koskenvuo et al  reemphasized that bowel preparation did not decrease the rate of surgical-site infection or complications in patients undergoing left or right hemicolectomy when compared with no bowel preparation.[8]

Some surgeons also prefer that the patient have an enema on the morning of the surgical procedure. A clear-liquid diet is allowed the day before the procedure. All oral intake is stopped the night before the operation, and only the essential medications are allowed, with a sip of water, on the morning of the procedure.

Preoperative antibiotics to cover gram-negative and anaerobic organisms (eg, piperacillin-tazobactam or ertapenem or a combination of a second-generation cephalosporin and metronidazole) are given within 1 hour of the incision time. Many surgeons also start alvimopan, a drug that helps prevent postoperative ileus, and continue it until the patient's bowel function has returned or for up to 7 days postoperatively. Deep vein thrombosis prophylaxis is also started on the day of surgery.

The SELECT trial, a multicentric randomized controlled trial, evaluated selective decontamination of the digestive tract (SDD) in patients with colorectal cancer who underwent elective curative surgery with a primary anastomosis.[9] The digestive tract was decontaminated with oral colistin, tobramycin, and amphotericin B in the treatment (SDD) group and with intravenous (IV) cefazolin and metronidazole in both the treatment and the control group. Patients in the SDD group had less anastomotic leakage than those in the control group, but the difference was statistically insignificant. The infectious complication rate was lower in the SDD group than in the control group.

Patient Preparation

The patient is placed in a lithotomy Trendelenburg (modified Lloyd-Davis) position with both arms abducted on arm boards. The legs are placed on stirrups, with adequate soft padding to prevent pressure sores on the skin and pressure-related nerve injury to the common peroneal nerves. Antiembolic stockings or compression devices are applied to the legs.

Ureteral catheters are used in left-side colectomies to prevent ureteral injury; however, because of the rarity of these injuries, the role and morbidity of ureteral catheters in these procedures is not well documented. In a study using data from the National Surgical Quality Improvement Project (NSQIP), Dolejs et al did not find a significant difference in the incidence of ureteral injury between left-side colectomy/proctectomy patients who underwent ureteral catheterization (0.7%; n = 8419) and similar patients who did not (0.9%; n = 128,021).[10] They concluded that ureteral catheters were associated with a longer operating time and increased overall morbidity and hence might not be necessary.



Approach Considerations

In the COVID-19 era, surgeons in all specialties have made modifications to their technique with the aim of reducing exposure to the virus. With respect to left-side colectomies, such modifications have included favoring minimally invasive surgery and performing intracorporeal anastomosis. Serra-Aracil et al reported preliminary results from 17 patients undergoing left-side colonic resection in whom a "don’t touch the bowel" technique involving intracorporeal resection and end-to-end anastomosis was employed.[11]

Open Left Hemicolectomy

After the patient is intubated under general anesthesia, a good muscle relaxant is administered and an endotracheal tube placed. A Foley catheter is inserted into the bladder for accurate measurement of urine output during the procedure and for at least 24 hours after surgery. An orogastric tube is placed to decompress the stomach during the operation; this tube is removed at the end of the procedure.

The entire abdomen is prepared with either povidone-iodine or chlorhexidine antiseptic solution. Sterile draping is applied, ensuring adequate exposure of the abdomen and allowing easy access to the rectal area, if necessary. An electrocautery device (Bovie), a LigaSure 10-mm coagulator, or an ultrasonic dissector device and suction tubing are set up. The operating surgeon stands on the right of the patient, with the assistant on the left of the patient. If available, a second assistant could stand between the legs of the patient.

The left colon is accessed via a generous midline laparotomy. (Some surgeons have suggested that a left transverse laparotomy may be associated with lower rates of respiratory complications and incisional hernias.[12] ) A thorough exploration of the abdominal cavity is performed. The entire colon is examined for palpable lesions. The surface of the liver is examined for any metastatic lesions.

Moist laparotomy pads are used to tuck the transverse colon and the small bowel loops cephalad and to the right, away from the operative field, for adequate exposure of the left colon and the mesenteric vessels. Self-retaining retractors such as the Bookwalter or Thompson retractor can be used for this. A St Mark retractor should be available if access to the pelvis is necessary.

The length of the colon to be resected is determined in part by the location of the lesion; this, in turn, determines the extent of intestinal devascularization that will ensue from proper lymphadenectomy and obtaining a longitudinal margin (along the length of colon) of at least 5 cm from the lesion proximally and distally. A minimum of 12 lymph nodes within the mesentery is considered an adequate resection when a left hemicolectomy or sigmoidectomy is performed for cancer.

Lateral approach

The lateral approach is preferred by most surgeons for open colectomies. The assistant holds the sigmoid colon and retracts it medially and upwards. The surgeon then starts dissecting along the white line of Toldt, which is the line of attachment to the parietal peritoneum on the lateral side. This is extended superiorly up to the splenic flexure and inferiorly down to the level of the pelvic brim.

At this point, the left ureter is identified in order to prevent inadvertent injury. The ureter is seen crossing the gonadal vessels at the level of the pelvic brim and has a characteristic peristaltic movement (akin to the movement of an earthworm).

The medial border of the mesentery is then easily lifted off the retroperitoneal attachments, which helps identify the inferior mesenteric artery (IMA) and other vascular branches. The IMA and the inferior mesenteric vein (IMV) are ligated and divided. The mesenteric attachments are then divided towards the colon, which is dictated by the length of the colonic segment to be removed. Sometimes, it may be necessary to divide the left branch of the middle colic artery, if the lesion is located in the splenic flexure.

To take down the splenic flexure, the patient is placed in a reverse Trendelenburg position. The retractors are adjusted in such a way that the transverse colon is released and the small bowel is packed towards the right lower quadrant. The transverse colon is mobilized by dividing the greater omentum and entering the lesser sac.

The colonic mesenteric attachment is then dissected off the retroperitoneum and extended laterally toward the splenic flexure, with care taken not to injure to the splenic vessels. A combination of blunt dissection and electrocoagulation is necessary to enter the right plane and avoid bleeding complications.

Once the colonic segment is mobilized, the ends of the colon are then divided with a gastrointestinal anastomosis (GIA) stapler. The resected specimen is sent to the pathology department for histologic analysis.

After the colon resection, the two ends of the colon are anastomosed to each other either by using the stapling device or by using the handsewn technique. The anastomosis can be performed in an end-to-end, end-to-side, or side-to-side manner.

If the entire sigmoid colon is removed, the colon-to-rectum anastomosis is usually performed with a circular stapling device such as the end-to-end anastomosis (EEA) stapler. The anvil of the EEA stapler is sutured to the distal end of the proximal portion of the colon. The surgeon then stands between the patients’ legs and passes the stapling device through the anal canal into the rectum until it reaches the proximal end of the rectal stump.

Once in place, the EEA stapler is opened, exposing the probe, which is then attached to the anvil at the other end of the colon. Finally, the EEA stapler is closed and fired to complete the anastomosis. The donuts obtained after stapling are checked for complete rings.

The anastomosis is tested for any leaks by placing the patient in the reverse Trendelenburg position and filling the pelvis with warm saline. The surgeon then passes a rigid sigmoidoscope through the anal canal and directly visualizes the anastomosis.

After clamping the colon proximal to the anastomosis, the surgeon insufflates the rectum with air via the sigmoidoscope. The colon is checked for adequate distention with air and for any bubbling of air in the pool of saline in the pelvis. The presence of a stream of bubbles indicates a positive leak test, and every measure must be taken to ensure that the leak is fixed. This may require placing sutures across the gap or, in some cases, complete revision of the anastomosis.

The entire peritoneal cavity is then irrigated with copious amounts of warm saline solution. The wound is closed in layers. The fasciomuscular layer is closed either in a continuous or an interrupted fashion. No. 1 polydioxanone or polypropylene suture material is ideal for this layer. The subcutaneous layer is not usually sutured. The skin is closed using skin staples or interrupted vertical mattress sutures using 4/0 nylon or polypropylene sutures.

Medial approach

In the medial approach, the origin of the IMA is exposed first; this is located just below the third portion of the duodenum. The root of the mesentery is incised to further reach the vessels. In the high-ligation technique, the IMA is then ligated and divided proximal to the origin of the left colic artery.

Next, the IMV is ligated and divided. The ureter is identified at this stage, usually crossing the gonadal vessels at the pelvic brim. This is done in order to prevent inadvertent injury to the ureter.

The mesentery is then elevated off the retroperitoneum, and the line of mesenteric division is delineated. The rest of the left colon is mobilized by dividing the mesenteric attachments. The lateral attachments of the colon are then divided along the white line of Toldt. This frees up the entire segment of the colon. From this point forward, the procedure is much the same as in the lateral approach.

Secondary or delayed primary closure

The choice is sometimes made to leave the wound open at the time of surgery for secondary or delayed primary closure in an effort to reduce the incidence of surgical-site infection (SSI). In a retrospective propensity-matched study comparing colorectal surgery patients whose wounds were left open with patients who underwent primary skin closure, Mullen et al found that secondary or delayed primary closure eliminated superficial surgical infections but did not decrease deep or organ-space infections; in addition, it was associated with increased resource use.[13]  

In a study involving 1083 patients who underwent elective or emergency colectomy, Kay et al compared the rates of superficial and deep surgical-site infection (SSI) in patients with a closed incision (n = 945) and those with a blowhole closure (n = 138).[14] The rate of superficial and deep SSI was 9.1% in patients with a closed incision and 5.1% in those with a blowhole closure. Although the overall difference was not significant, when adjustments were made for  approach and wound class, the incidence of SSI was significantly reduced with blowhole closure. 

Postoperative Care

Postoperatively, the patient is extubated and transferred to the recovery room for appropriate monitoring before transfer to the floor. The patient is kept on nil per os (NPO) status, except for oral medications with a sip of water for up to 24 hours. Intravenous (IV) fluids and antibiotics are continued for up to 24 hours. Antiembolic stockings are continued, and deep vein thrombosis (DVT) chemoprophylactic drugs (eg, low-molecular-weight heparin [LMWH]) are started on postoperative day 0.

After 24 hours, the patient is allowed to have clear liquids as tolerated, with IV fluids still running until the patient tolerates oral intake. The Foley catheter is removed on postoperative day 1. The patient is encouraged to ambulate and perform incentive spirometry to prevent atelectasis.

Daily laboratory tests, including at least a complete blood count (CBC) with differential and basic metabolic panel, are performed until the patient has tolerated a clear-liquid diet, depending on clinical progress and recovery. The diet is slowly advanced after the patient has had return of bowel function, which is evidenced by passing either flatus or feces. Only after the patient has had a bowel movement, has tolerated at least a full-liquid diet, and has ambulated is he or she deemed medically fit for discharge.

Although earlier studies suggested that gum chewing in the postoperative period is beneficial for reducing the duration of ileus,[15] a randomized trial from 2015 did not find this measure to be advantageous.[16]

Follow-up in the office 10-14 days postoperatively is ideal for removal of staples and sutures and for discussing the results of the pathologic analysis of the specimen. Depending on the pathologic stage, the patient may require systemic therapy in the form of chemotherapy.[3, 4, 5, 1]


Early complications of open left colectomy are as follows:

  • Excessive bleeding
  • Ureteral injury
  • Wound infection, both superficial and deep
  • DVT and pulmonary embolism (PE)
  • Urinary tract infection
  • Pulmonary complications (eg, atelectasis/pneumonia)
  • Cardiac complications (eg, myocardial infarction, congestive heart failure)
  • Prolonged ileus - Provided that prolonged ileus does not develop, bowel function appears to return more quickly after left-side colon resections than after right-side resections [17]  
  • Wound dehiscence and evisceration
  • Anastomotic leak

Late complications are as follows:

  • Anastomotic stricture
  • Tumor recurrence - There is some evidence to suggest that adenomas are more likely to recur after left hemicolectomy than after right hemicolectomy [18, 19]
  • Bowel obstruction secondary to adhesions - In a study of postoperative adhesion-related complications (ARC) in 64,532 patients who underwent colectomies, Etter et al [20]  found that ARC led to one fourth of all first rehospitalizations within the first year after colectomy and found a minimally invasive approach to be protective against ARC
  • Sexual/urinary dysfunction (due to autonomic nerve injury)