Low Rectal Anastomosis
Kenneth D. Hatch
GENERAL PRINCIPLES
Rectosigmoid resection and anastomosis is indicated for tumor-reductive surgery in ovarian cancer, pelvic exenteration, and rarely for radiation-induced hemorrhagic proctitis. The procedure includes division of the sigmoid colon above the tumor involvement and resection of the rectum below the tumor in the retroperitoneal space.
Definition
Low rectal anastomosis (LRA) refers to resection of the rectosigmoid with the anastomosis being made below the peritoneal reflection in the cul-de-sac of Douglas. Rectal anastomoses are classified according to their distance from the anal verge. A high anastomosis takes place above the peritoneal reflection and would normally be 11 cm or greater. A low anastomosis is 7 to 11 cm and a very low anastomosis would be less than 7 cm. In gynecologic oncology, a rectal length of 6 cm is considered favorable for successful anastomosis after pelvic exenteration.
Anatomic Considerations
The rectum is 11 to 15 cm in length. The proximal 5 cm is intraperitoneal and begins where the sigmoid tinea disappears. The retroperitoneal segment begins at the peritoneal reflection in the cul-de-sac. The rectum ends at the upper end of the anal canal which is normally 2 cm in length (Fig. 25.1). The cervix is about 10 cm from the anal verge. The levator ani muscle attaches to the rectum at the upper end of the anal canal. The middle rectal artery runs just cephalad and ventral to the levator muscle. The superior rectal artery is the major vascular supply for the entire rectum and sends anastomoses to the middle rectal. Since the superior rectal artery is transected during the operation, these anastomotic vessels are important for healing. The middle rectal artery is usually not sacrificed in ovarian cancer surgery.
The length of rectal stump remaining and the history of radiation therapy will affect the surgeon’s decision for the type of anastomosis.
There are three types of anastomoses.
The end-to-end anastomosis is most often used when the rectal length is 9 cm or greater. This is most often the situation after ovarian cancer debulking.
The side-to-end anastomosis is indicated when the rectal length is between 6 and 8 cm.
The rectum is a storage reservoir for feces and provides proprioceptive feedback that allows the patient to discern liquid, solid, and gas. Resection of the rectum below 8 cm will interfere with these functions. An end-to-end anastomosis at this level will lead to frequent bowel movements as the sigmoid peristalsis delivers feces into the rectum. The side-to-end anastomosis provides extra storage capacity in the 4 to 5 cm of sigmoid distal to the anastomosis (see Tech Figs. 25.1 and 25.2).
The colonic J-pouch is indicated for very low anastomosis below 6 cm. It provides more storage than the side to end. It also decreases the pressure of the sigmoid peristalsis due to the detubularization effect (see Tech Figs. 25.3 and 25.4).
The end-to-end anastomosis is demonstrated in Chapter 27, Radical Debulking of Ovarian Cancer in the Pelvis (Video 27.1).
This chapter will demonstrate the side-to-end anastomosis and the colonic J-pouch.
PREOPERATIVE PLANNING
Recent publications have questioned the use of mechanical bowel prep prior to planned bowel resection.
Since a diverting colostomy may be required due to operative factors that predict a high risk of anastomotic leak, it seems illogical to leave a column of feces in the remnant colon and thus, mechanical cleansing for all of these patients is preferred.
Blood should be available depending on the operation that leads up to the LRA.
Compression devices on the lower extremity.
Stapling equipment available.
Patients who are to have an exenteration will need to be marked for ostomy sites.
SURGICAL MANAGEMENT
Positioning
The patient will be in the lithotomy position in padded Yellofins or Allen stirrups.
 Figure 25.1. The anatomy of the rectum and anal canal. |
PROCEDURES AND TECHNIQUES
Procedures and Techniques
There are two techniques included in this section:
Side-to-end anastomosis (Baker anastomosis)
Colonic J-pouch.
They are demonstrated in the video (Video 25.1 
).
).The end-to-end anastomosis is shown in Chapter 27, Radical Debulking of Ovarian Cancer in the Pelvis.
Side-To-End Anastomosis (Baker Anastomosis)
Most surgeons prefer to use the thoracoabdominal stapler to transect the rectum and then place the staple cartridge end of the circular stapler through the anus and advance the spike through the staple line (Tech Fig. 25.1). This avoids the “bunching up” of the tissue that results from placing a purse-string suture around the large diameter of the rectum.
Choose the largest circular stapler that the sigmoid will accommodate. A 31 mm is ideal to prevent stricture formation.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
