This is a prospective randomized controlled study that was conducted on patients of both sexes and definite age group at National Cancer Institute-Egypt and with adenocarcinoma of the rectum located within 15 cm from the anal verge. Tumor localization was categorized as the upper rectum (distal border of tumor is from 10 to 15 cm from the anal verge), middle rectum (5 to 10 cm from the anal verge) or lower rectum (less than 5 cm from the anal verge) as measured by colonoscopy and digital rectal examination. Patients were classified into two groups; robotic assisted rectal surgery and conventional laparoscopic rectal surgery.Baseline demographics (gender, age, ASA, BMI), preoperative data (distance of the tumor from the anal verge, clinical stage, whether preoperative chemoradiation (CRT), presence of residual tumor after CRT, intraoperative data (preparation time, actual operative time, estimated blood loss, conversion rate to open surgery), postoperative data (pathological stage, number of harvested lymph nodes, macroscopic completeness of resection in the form of proximal margin, distal margin, circumferential radial margin) and immediate postoperative outcome within one month (days of return of bowel function, days of hospital stay, complications, if any, like anastomotic leakage, ileus,wound problems and others, rate of re-operation, rate of readmission & 30-days mortality) were analyzed and compared.The criteria for patients selection were the following: histological diagnosis of adenocarcinoma of rectum, no anesthesiological contraindications to minimally invasive surgery, age ≤ 75 years, American Society of Anesthesiologists (ASA) ≤ 2 & the procedures performed by the same surgical team. Patients with metastatic disease, malignant bowel obstruction and those with irresectable tumor were excluded from our study.Preoperative workup (endoscopy with biopsies, radiological imaging including pelvic MRI, liver ultrasound, chest X-ray and routine abdominal and digital rectal examinations) was routinely carried out. The assignment of patients to either group was done by a permuted block randomization. It was an open-labeled study. The study was approved by the institutional review board of National Cancer Institute-Cairo University. All patients provided written informed consent.

Undoubtedly, robotic systems have largely penetrated the surgical field.For any new operative approach to become an accepted alternative to conventional methods, it must be proved safe and result in comparable outcomes. The purpose of this study is to compare the short-term operative as well as oncologic outcomes of robotic assisted and laparoscopic rectal cancer resection.

This is a prospective randomized controlled study that was conducted on all patients of both sexes and definite age group attending the National Cancer Institute and with adenocarcinoma of the rectum located within 15 cm from the anal verge who were eligible to be included in the study. Tumor localization was categorized as the upper rectum (distal border of tumor is from 10 to 15 cm from the anal verge), middle rectum (5 to 10 cm from the anal verge) or lower rectum (less than 5 cm from the anal verge) as measured by colonoscopy and digital rectal examination. Patients were classified into two groups; robotic assisted rectal surgery "The robotic system that we use is the da Vinci Si(Intuitive Surgical, Inc.,Sunnyvale,CA)" and conventional laparoscopic rectal surgery. Baseline demographics (gender, age, ASA, BMI), preoperative data (distance of the tumor from the anal verge, clinical stage, whether preoperative chemo-radiation "CRT", presence of residual tumor after CRT), intraoperative data (preparation time, actual operative time, estimated blood loss, conversion rate to open surgery), postoperative data (pathological stage, number of harvested lymph nodes, macroscopic completeness of resection in the form of proximal margin, distal margin, circumferential radial margin) and immediate postoperative outcome within one month (days of return of bowel function, days of hospital stay, complications, if any, like anastomotic leakage, ileus, wound problems and others, rate of reoperation, rate of readmission & 30-days mortality) were analyzed and compared.The criteria for patients selection were the following: histological diagnosis of adenocarcinoma of rectum, no anesthesiological contraindications to minimally invasive surgery, age ≤ 75 years, ASA ≤ 2 & the procedures performed by the same surgical team. Patients with metastatic disease, malignant bowel obstruction (MBO) and those with irresectable tumor were excluded from our study. Preoperative workup (endoscopy with biopsies, radiological imaging including pelvic MRI, liver ultrasound, chest X-ray and routine abdominal and digital rectal examinations) was routinely carried out. The assignment of patients to either group was done by a permuted block randomization. It was an open-labeled study i.e. patients, investigators (surgeons, researchers) and data collectors knew which procedure will be done to which patients. The study was approved by the institutional review board of the National Cancer Institute, Cairo University. All patients provided written informed consent.

Inclusion Criteria:

• histological diagnosis of adenocarcinoma of rectum
• no anesthesiological contraindications to minimally invasive surgery
• age 16 -75 years,
• ASA ≤ 2 &
• the procedures performed by the same surgical team.

Exclusion Criteria:

• Patients with metastatic disease,
• malignant bowel obstruction (MBO) and
• those with irresectable tumor