Robotic Abdominoperineal Resection (APR)

Se-Jin Baek

Seon-Hahn Kim

INDICATIONS/CONTRAINDICATIONS

Abdominoperineal resection (APR) has been a standard surgical treatment for rectal cancer since the first surgical case study was published by Miles in 1908. During the past few decades, sphincter-saving operations with colorectal or coloanal anastomosis (CAA) have replaced a large portion of APR because of the advancement of surgical instruments, including the anastomotic stapler, and neoadjuvant chemoradiation. Nevertheless, APR is still performed in at least 15-25% of patients with low rectal cancer. It is specifically used as treatment in patients with low-lying tumors involving the sphincter muscle, with poor sphincter function, or with a restrictive pelvis.

APR remains a challenging operation for treatment of low rectal cancer. Recently, robotic approach has been used for APR because the advanced technology of the robotic surgical system is effective for deep pelvic dissection. The da Vinci Surgical System (Intuitive Surgical System, Sunnyvale, CA) has the potential to overcome the potential limitations of laparoscopy by providing improved three-dimensional vision under the operator’s control, effective countertraction with the EndoWrist motion, and tremor elimination. This robotic system has been actively used in specialties that work in narrow spaces, such as urologic, gynecologic, cardiac, and rectal surgery. In the field of rectal surgery, utilization of the robotic system has become higher over time in patients with very low rectal cancer, which requires either intersphincteric resection (ISR) or APR. A multicenter survey of 12 large medical centers in Korea in 2015 showed that robotic ISR comprised 3.7% of the total ISR procedures in 2007, and 42.4% in 2014. Similarly, robotic APR comprised 5.1% of the total APR procedures in 2007, and 12.2% in 2014. These results showed the increased dependency on the robotic method for both ISR and APR.

In principle, the indications and contraindications for the use of robotic APR are the same as those for open and laparoscopic APR. Patients with medical diseases unsuitable for treatment with laparoscopic surgery are also unacceptable for robotic surgery. In addition, patients with a small stature may not be appropriate for robotic surgery because the limited operative workspace cannot accommodate the robotic arms.

PREOPERATIVE PLANNING

All patients should be preoperatively evaluated by routine laboratory tests including tumor markers, digital rectal examination, total colonoscopy with biopsy, abdominopelvic computed tomography (CT), either an endorectal ultrasound or pelvic magnetic resonance imaging, and chest CT. Many patients are treated with 5-6 weeks of neoadjuvant chemoradiation (5,040 cGy in 28 fractions). Each patient is reevaluated 8-10 weeks later by final decision regarding sphincter preservation. The optimal stoma site is marked in the left lower quadrant (LLQ). Other steps in preoperative planning for robotic APR are similar to those used in open and laparoscopic APR.

SURGERY

Robotic APR is composed of three steps:

Colonic phase—ligation of the mesenteric vessels and mobilization of the left colon
Pelvic phase—pelvic dissection including total mesorectal excision (TME)
Perineal phase

There is relatively a little difference between the hybrid and fully robotic approach to APR because there is no mobilization of the splenic flexure and minimal mobilization of the left colon. This description is for a fully robotic procedure.

Operating Room Setup and Patient Positioning

The assistant is to the patient’s right side and the scrub nurse is at the lower right side of the table (Fig. 37-1). The vision cart is located at the patient’s feet. If a second monitor is prepared, it is set across from the assistant on the left side of the table. A sterile pocket for the assistant’s instruments is located at the level of patient’s right knee.

The patient is placed in a modified lithotomy position with legs in adjustable stirrups. The patient’s legs are abducted and slightly flexed at the knees and arms are tucked alongside the body to lessen the possibility of shoulder injury. A vacuum-mattress device secures and pads pressure points and bony prominences to avoid shifts during position changes. A urinary catheter is placed, and a body warmer and pneumatic compression devices are applied to prevent hypothermia and deep vein thrombosis. The patient is then placed in a Trendelenburg position with the right side down. The angle and steepness are adjustable during the initial exposure.

Port Placement and Docking

Port placement of a fully robotic APR is similar to that of a fully robotic low anterior resection. The location of the LLQ port is slightly medial because it is used as a stoma site (Fig. 37-2). All ports are placed under direct laparoscopic vision.

The 12-mm da Vinci camera port is placed 3-4 cm above the umbilicus.
The 8-mm da Vinci instrument arm 1 port is placed on the right spinoumbilical line at the crossing of the midclavicular line (MCL).
The 8-mm da Vinci instrument arm 3 port is placed ˜3 cm sub-xiphoid and ˜2 cm medial to the right MCL.

FIGURE 37-1 Operating room setup.

FIGURE 37-2 Port placement and docking. MCL, midclavicular line.
The 8-mm da Vinci instrument arm 2 port is placed within the lateral border of the LLQ stoma site.
The 8-mm da Vinci instrument arm 2/3 port is placed 7-8 cm below the left costal margin, slightly medial to the left MCL.
The 5-mm assistant port is placed midway between the arms 1 and 3 ports for suction/irrigation, ligation, and retraction.

Note 1: Once the arm 3 port is placed, the location is better, because the distance from the camera port is longer (a minimum of 8 cm) and the angle between arm 3 (camera) and arm 1 ports is wider.

Note 2: Once the arm 2/3 port is placed, the location is determined to make symmetrical equilateral triangles with arm 3—camera—arm 2/3 ports and arm 2—camera—arm 2/3 ports to minimize external collisions.

During the colonic phase, the da Vinci instrument arms 1, 3, and 2/3 as 2 are used to dock the robot. During the pelvic phase, the da Vinci instrument arms 2/3 and 3 are undocked, and the 2 and 2/3 as 3 arms are used to re-dock the robot. A port on the right upper quadrant is used as a second assistant port for cephalad traction of the rectum.

After port placement and initial exposure, the patient cart is approached obliquely from the patient’s left leg side toward the camera port (Fig. 37-3). The left stirrup might need to be adjusted and moved medially to allow space for the patient’s cart column and arm 1. The angle for the patient cart roll up is defined by a straight line running from the camera port and crossing the anterior superior iliac spine. After the patient cart is positioned, docking of the robotic arms is completed by maximizing the space between the arms.

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