Operative indications

In general, MIRP has the same operative indications as open radical retropubic prostatectomy (RRP). Patients who are believed to have organ-confined prostate cancer, based on Gleason score (grade), clinical stage, prostate-specific antigen (PSA), and staging studies, are appropriate candidates for radical prostatectomy. Patient age, life expectancy, and overall health also are important factors in the clinical decision to treat prostate cancer, but are beyond the scope of this text. Pelvic lymphadenectomy can be performed at the same time as MIRP, if indicated by the above factors. This is a distinct advantage of MIRP over radical perineal prostatectomy, in which lymph node dissection cannot be performed under the same anesthesia or incision.

Patients with obesity, large prostate glands, large median prostate lobes, or prior major pelvic or abdominal surgery tend to be more challenging and should be avoided early in the surgeon’s learning curve. In the patient who has had a prior laparoscopic inguinal hernia repair, the initial development of the extraperitoneal space can be extremely difficult and could result in a bladder or pelvic vascular injury. These patients should be counseled about the increased risk for conversion to an open procedure.

All patients should be counseled about other options for treatment of localized prostate cancer, including watchful waiting or active surveillance for appropriate patients, other forms of prostatectomy, external-beam radiation therapy, brachytherapy, and cryotherapy. Focal ablative techniques such as high-intensity focused ultrasound (HIFU) also may be discussed, but currently in the United States these are being performed only under clinical protocols.

Preoperative evaluation, testing, and preparation

Prostate cancer staging studies (such as bone scan, computed tomography [CT] scan, and magnetic resonance imaging [MRI]) should be completed if indicated by the tumor characteristics noted previously. All patients undergoing MIRP should undergo standard medical clearance for major surgery according to their specific health factors. Patients with pulmonary disease may need preoperative pulmonary function testing to ensure they can tolerate insufflation without hypercarbia. All patients should have a blood type and screen before surgery; the rate of transfusion with MIRP, however, has been quite low in most series (about 2.7%). The day before the procedure, the patient completes a bowel preparation of one bottle of magnesium citrate along with a clear liquid diet. Some surgeons also recommend an enema the morning of surgery to evacuate the rectum completely. Recently, some surgeons have advocated omission of any formal bowel preparation.

All patients are counseled preoperatively about possible complications of radical prostatectomy, including erectile dysfunction, stress urinary incontinence, rectal injury, and pelvic nerve or vascular injury. Other general risks include bowel injury, ileus, bleeding, and infection. Patients also should be counseled on whether a nerve-sparing procedure will be performed in light of their pathologic features and risk factors.

Patient positioning and operative room setup

Sequential pneumatic compression devices or compression stockings are placed preoperatively. A dose of prophylactic antibiotic, such as cefazolin, is administered intravenously. Patients are placed on a large beanbag stabilizer on the operating table. After induction of endotracheal anesthesia, an orogastric tube is placed. The anesthesiologist should ensure that the patient remains completely paralyzed during the entire procedure. To improve intraoperative visualization, intravenous fluids are limited until after the urethrovesical anastomosis is completed to decrease the amount of urine spilling into the field.

The abdomen is clipped of hair, the arms are tucked at the patient’s sides, and the elbows are padded with foam. Foam also is placed on top of and underneath the shoulders to prevent excessive pressure on the shoulders after subsequent placement into steep-Trendelenburg position. The beanbag stabilizer then is rolled up around the outside of the arms and shoulders and connected to suction to deflate and hold its position. The beanbag is important in preventing patient movement during steep-Trendelenburg positioning. We do not use any additional taping during positioning.

For standard LRP, the legs remain in the supine position and are secured to the bed with a safety strap. With RARP, the legs are placed in low lithotomy position with Yellowfins stirrups (Allen Medical Systems, Acton, Mass.), taking care not to place excessive strain on the thigh or groin muscles, which can produce postoperative neurapraxia. Alternatively, a spread-leg position (using spreader bars designed for the table) can be used with the patient in supine position. An overview of the patient positioning is shown in Figure 33-1.

FIGURE 33-1 Patient positioning during robot-assisted radical prostatectomy. Positioning is the same for standard laparoscopic radical prostatectomy except the legs remain in supine position.

For standard LRP, the surgeon stands on the left side of the patient, and the assistant stands on the right. The laparoscopic video monitor is positioned at the foot of the bed at a comfortable height. A robotic camera positioner (Aesop, Intuitive Surgical, Sunnyvale, Calif.) or mechanical holder can be used to provide a stable camera position during the operation. These devices also allow the assistant to use both hands to assist during the procedure. Otherwise, the assistant holds the laparoscope, and a second assistant may be necessary at certain points of the case to perform minor tasks. We find it helpful to place a padded sterile Mayo stand over the patient’s head during the procedure. This stand protects the patient’s face and provides a surface for the assistant to stabilize his or her left arm while holding the camera.

If a four-arm robot is to be used for RARP, then the assistant generally stands on the patient’s right side. The fourth arm can be placed on either side on newer versions of the robotic system; the assistant generally is on the opposite side of the fourth arm. If a three-arm robot is used, then two assistants may be necessary. A laparoscopic video monitor can be positioned on either the right or left side of the patient for the assistant to view, depending on operating room setup and space. Some da Vinci Surgical Systems (Intuitive Surgical) have monitors positioned atop the robotic system for the assistant.

Standard laparoscopic instruments are used in both LRP and RARP. Because the assistant operates the laparoscopic graspers during RARP, bariatric length instruments are helpful for adequate reach and to decrease external collisions with the robotic arms. An ultrasonic scalpel or bipolar dissector is helpful in LRP. The authors generally do not use monopolar cautery during LRP. For RARP, monopolar curved scissors, as well as bipolar graspers, are used on the robotic arms for the dissection.

Positioning and placement of trocars

For MIRP, a fan-shaped configuration of trocars in the lower abdomen is used (Fig. 33-2). Five trocars are used during LRP, and six trocars are placed for RARP. A Foley catheter is inserted in a sterile fashion on the field, and the bladder is emptied. Bulb suction is preferred to ensure that the bladder remains empty during the early dissection. After gaining access to the peritoneal cavity, a 12-mm blunt trocar is placed in a supraumbilical midline location for the laparoscope in both types of MIRP. The bed then is placed into Trendelenburg position (13 to 15 degrees, head down).

FIGURE 33-2 Trocar configuration during laparoscopic radical prostatectomy.

For standard LRP, a 12-mm trocar is placed 2 fingerbreadths from the left anterior superior iliac spine (ASIS) on a line from the ASIS to the umbilicus (see Fig. 33-2). This trocar is used by the surgeon to pass suture into the abdomen throughout the procedure and for the surgeon’s grasper during dissection. A 5-mm trocar is placed along this line in the left lower quadrant at the lateral border of the left rectus muscle. The ultrasonic scalpel is used through this trocar during the dissection. Two additional 5-mm trocars are placed in a mirror image in the right lower quadrant for the assistant to use for the suction irrigator and retraction during the procedure. The authors prefer to use low-profile trocars during standard LRP to allow for maximal instrument reach into the pelvis.

For RARP, a similar port configuration is used (Fig. 33-3). Two robot ports are placed in the left lower quadrant as described previously. The third robot port is placed at the lateral border of the rectus in the right lower quadrant on the same line from the umbilicus to the ASIS. A 12-mm port is placed in the right lateral position for the assistant to pass suture into the abdomen and is used for retraction. An additional 5-mm assistant port is placed in the right upper quadrant, between the laparoscope port and right robot port. The suction irrigator is operated through this port by the assistant.

FIGURE 33-3 Trocar configuration during robot-assisted radical prostatectomy (teal blue = robotic 8-mm trocar).

Once all trocars are placed, the robotic arms are docked to robotic trocars, and the instruments are inserted under direct vision. It is imperative that the robot arms have free range of motion without colliding into one another or the patient’s extremities; this should be assessed after docking. A Prograsp (Intuitive Surgical) grasper is used for the fourth arm (left lateral robotic trocar). We use a bipolar grasper in the left arm (left medial robotic trocar) and monopolar curved scissors in the right arm (right robotic trocar).

Operative technique

MIRP can be performed using either a transperitoneal or extraperitoneal approach. The transperitoneal approach is preferred by most surgeons because of a larger working space and greater familiarity with the access technique. Only the transperitoneal approach is discussed in this chapter.

The general steps of MIRP are discussed next. Differences between RARP and LRP will be discussed when applicable. The steps of MIRP can be divided as follows:

Creation of the Extraperitoneal Space

After gaining safe access to the abdomen and placing all trocars, the surgeon must mobilize the bladder to enter the extraperitoneal space (i.e., the space of Retzius, or retropubic space). The urachus and medial umbilical ligaments are divided high on the anterior abdominal wall using cautery or the ultrasonic scalpel. The peritoneum then is incised lateral to each umbilical ligament down posterior to the vas deferens (Fig. 33-4). The vas deferens is dissected and divided bilaterally. After the bladder has been mobilized from the anterior abdominal wall, the dome of the bladder is retracted cephalad to provide exposure to the pelvis. The assistant’s locking grasper retracts the bladder during LRP, whereas the fourth arm of the robot is used for this purpose during RARP.

FIGURE 33-4 Outline of peritoneal incision during minimally invasive radical prostatectomy. Incision across medial umbilical ligaments and urachus on anterior abdominal wall continuing lateral to each ligament down past the vas deferens bilaterally.

The retropubic space is further developed in a bloodless plane of loose areolar tissue. Care is taken to identify the iliac vessels and pubic bone early to avoid injury and guide the dissection. Once the pubic bone is identified, the tissue plane along the inferior edge of the bone is defined to completely develop the retropubic space. The endopelvic fascia then is identified, and superficial fat is removed from the dorsum of the prostate and endopelvic fascia bilaterally. The fat overlying the dorsum of the prostate normally contains a superficial dorsal vein, which can be divided with bipolar cautery or the ultrasonic scalpel. Finally, the puboprostatic ligaments are identified and cleaned of all adipose tissue bilaterally. Care should be taken at this point in the procedure to identify and preserve, if possible, any accessory pudendal arteries that may perforate the endopelvic fascia and course into the pelvis. These arteries may play a key role in preservation of postoperative erectile function.