Laparoscopic Low Anterior Resection with Diverting Loop Ileostomy for Rectal Cancer with Conversion to Open Approach

Laparoscopic low anterior resection (LAR) is a complex surgical procedure used for resecting the distal sigmoid colon or rectum while preserving sphincter function. The patient is a 37-year-old, obese male with rectal cancer. Abdominal access is gained through four laparoscopic port sites. The omentum is freed from the transverse colon to enter the lesser sac. The splenic flexure and descending colon are mobilized from the retroperitoneum. The left colic artery is identified and divided. Following proximal mobilization, the dissection is carried towards the pelvis. The sigmoid colon is mobilized, and the presacral space is entered. The inferior mesenteric artery is divided between clips. The dissection in this case could not be carried down low enough in a laparoscopic fashion, and a lower midline incision was made. A suitable area on the descending colon is identified and the marginal artery divided. The proximal bowel is then divided with a stapler. A flexible colonoscope is then used to confirm tumor location and the rectum is divided below the tumor. Finally, a Baker type side-to-end anastomosis is performed with a powered EEA stapler, and its integrity verified endoscopically under water. A diverting loop ileostomy is then created at a previously marked site and the abdomen closed. In this video, we demonstrate the surgical steps of this procedure and provide insight into our intraoperative decisions.

Low anterior resection; colorectal cancer; open surgery, side-to-end anastomosis.

Colorectal cancer, encompassing carcinomas of the colon and rectum, is among the most common cancer diagnoses in the US and across the globe. Arising from the glandular epithelial cells lining the rectum, it is estimated that approximately 45,000 new cases of rectal cancer are diagnosed in the US annually.¹ Rectal cancer is the 10th most lethal cancer responsible for over 300,000 deaths globally each year, despite a substantial number of deaths miscategorized as due to colon cancer.^2, 3 

Adenocarcinomas represent most of all rectal cancers and can be clinically silent or present due to rectal bleeding, altered bowel habits, fatigue, and weight loss. Risk factors including both non-modifiable and modifiable factors like age, familial syndromes, IBD, obesity, smoking, diet, and history of radiation; they are similar to those of colon cancer.⁴ Pathogenesis of rectal cancer has been described using Adenomatous polyposis coli (APC) gene adenoma-carcinoma progression, ulcerative colitis induced dysplasia and hereditary nonpolyposis colorectal cancer (HNPCC) pathways.^5–7 However, the precise underlying mechanisms and mutations leading to the development of rectal cancer are still unknown. Colonoscopy has led to a notable decline in incidence and mortality among older individuals; however, cases of rectal cancer in those younger than 50 years have significantly risen.⁸ Rectal cancer accounts for over 37% of cases of colorectal cancers in those under the age of 50 years and 36% of cases in those aged 50–64 years.⁹

Surgical resection remains the mainstay of curative therapy for rectal cancer.¹⁰ Staging for rectal cancer patients consists of chest and abdominal CT scanning as well as a rectal MRI or endoluminal ultrasound. Transanal excision (TAE) or transanal endoscopic surgery (TES) can be performed for localized T1 disease. However, the results of these techniques are poor for T2 disease and associated with high recurrence and nodal metastases.^10, 11 Locally advanced patients with T3 or greater and/or clinical stage 3 with local adenopathy greater than 1 cm on imaging usually receive total neo-adjuvant therapy (TNT). Approximately 20–25% of these patients may achieve a complete pathologic response and potentially avoid surgical resection. However, the majority will need either a LAR with a total mesorectal excision (TME) or an abdominoperineal resection (APR).^12–15 The 5-year-survival rate for early-stage localized disease is over 90% and with regional lymph node involvement is 73%. However, for patients with stage 4 disease the 5-year survival rates are about 15%.^1, 16, 17

In this video, we perform a LAR with diverting loop ileostomy for a 37-year-old male with locally advanced rectal cancer. During the procedure, a laparoscopic TME was done with conversion to an open approach and a distal Baker type side-to-end anastomosis was performed.

The patient is a 37-year-old male presenting with stage III rectal cancer. Patient has no relevant past medical or surgical history. His body mass index (BMI) was 38.6 and American Society of Anesthesiologist (ASA) score 2. 

The patient was examined in the office and was in no apparent distress with normal vital signs. Abdominal exam was normal with an obese but soft abdomen, with no distension or tenderness to palpation.

Various pathogenic pathways and genetic mutations have been investigated in the development of colorectal cancer. Alterations of colonic and rectal epithelia lead to the development of benign polyps, which can further progress into invasive carcinoma over time. The underlying genetic mechanisms for these sequential changes have been attributed to hypermethylation, DNA mismatch repair genes, and/or microsatellite instability.^18–20 The APC adenoma-carcinoma pathway associated with familial adenomatous polyposis (FAP); and the involvement of DNA repair genes (MLH1, MSH2, MSH6, PMS2) in Lynch syndrome, are among the most commonly recognized hereditary syndromes, alongside IBD-triggered dysplastic changes that lead to the development of colorectal cancer. Once invasive cancer has developed, malignant cells can invade local surrounding organs, or metastasize to distant sites through lymphatic, perineural, and hematogenous spread. Based on the stage and spread of the tumor, rectal cancer can be asymptomatic or present with various bowel and/or systemic symptoms. Serious tumor-related emergencies for rectal cancer can present with bleeding, perforation, and obstruction needing immediate attention.

Surgical resection is the only curative therapy for rectal cancer. However, the utilization of TNT for rectal cancer patients has led to complete clinical response rates ranging between 15–80%.^21–23 These patients can be managed with watchful waiting instead of surgery, with similar survival rates, and lower morbidity and mortality rates.^24, 25 Following accurate pretreatment disease staging, the most appropriate treatment options are selected based on patient factors and surgeon preferences. Surgical approaches range from local excisions (TAE, TES) to abdominal procedures like LAR, APR, or multivisceral resections. These procedures often include TME to reduce risk of local recurrences and improve patient outcomes.^26, 27 For locally advanced rectal cancers, multimodal management including neo-adjuvant or adjuvant chemotherapy and radiotherapy are employed routinely. Patients receiving TNT prior to surgical resection have significantly higher overall survival, pathological complete response, and complete clinical response rates.^28–31 

The rationale for surgical resection is complete eradication of malignant tissue with goal to cure and improve quality of life. In rare cases with malignant or recurrent disease, palliative surgical procedures are performed to relieve patient distress and symptoms.

Depending on the staging of rectal cancer and individual patient factors, an appropriate resection technique and surgical approach are determined by the surgeon. Contraindications to curative surgery are limited to patients with significant medical comorbidities like cardiopulmonary, renal, and/or advanced metastatic disease. 

As shown in the video, the main surgical steps for this procedure are: (1) Abdominal access with four laparoscopic port sites, (2) entry into lesser sac to mobilize the splenic flexure and descending colon with division of the left colic artery, (3) mobilization of the sigmoid colon and rectum, (4) isolation and clipping of the Inferior mesenteric artery, (5) continued distal mobilization in an attempt to get distal to the tumor, (6) midline laparotomy for conversion to open approach because we could not get distal to the tumor, (7) marginal artery and proximal bowel division with GIA 100 stapler, (8) extension of incision, (9) perform TME, (10) division of rectum with Contour 4.5-mm stapler, (11) distal side-to-end anastomosis with Covidien 31-mm EEA stapler and endoscopic leak test, and (12) prepare the loop ileostomy site and close the abdomen. This technique of LAR results in extensive mobilization of the colon, to aid adequate resection with a subsequent tension-free distal anastomosis and diverting loop ileostomy. The blood flow through the marginal artery of Drummond is preserved to ensure adequate supply to the colon.

Surgical approaches for treatment of rectal cancer have evolved considerably over the years. Historically, the LAR approach was first described by Hartmann in 1921.³² Subsequent modifications to LAR technique have established it as a safe and effective treatment option for rectal cancer. Two notable improvements include the improvement of sphincter sparing LAR surgery and transanal stapling techniques allowing for effective low pelvic anastomosis. Sphincter sparing LAR with TME resection achieves adequate negative margins and is associated with significantly low recurrence rates (< 10%).^33,34 

Laparoscopic, robotic, and open approaches have been used for LAR surgery with comparable oncological outcomes.³⁵ The decision for the most appropriate approach is determined by the surgeon based on patient factors and intraoperative circumstances. As observed in this case, owing to patient factors like severe obesity, the pelvic access was very limited. In order to appropriately identify and dissect the distal margin of the rectal tumor, the laparoscopic approach was converted to an open LAR procedure. This was done to allow for adequate tumor resection with negative margins. Furthermore, the open approach ensured sufficient margins to close with a tension-free anastomosis. The most frequently encountered postoperative complications of LAR are anastomotic leakage and hemorrhage. Intraoperative anastomotic integrity testing and creation of diverting loop ileostomy after LAR are two established techniques known to lower rates of postoperative morbidity, consequences of anastomotic leaks and need for reoperations.^11,36 

Areas of ongoing investigation are focused on discovering novel diagnostic and therapeutic modalities for rectal cancer. Utilization of concurrent fluoropyrimidine chemotherapy (CRT) and immunotherapy agents like PD-1 inhibitors have shown promising results in the treatment of various stages of rectal cancer.^37,38 Continued advancements in medical therapies may aid the curative effects of surgery and have substantial effects on patient outcomes including quality of life.

• Covidien laparoscopic harmonic scalpel
• Endo GIA™ 100 stapler
• Contour 4.5-mm stapler
• Covidien 31-mm end-to-end anastomosis stapler

Nothing to disclose.

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.