Preperitoneal Robotic-Assisted Radical Prostatectomy

The preperitoneal (also referred to as an extraperitoneal or retroperitoneal) approach to performing a robotic-assisted radical prostatectomy (RARP) aims to mimic access obtained during an open retropubic radical prostatectomy technique, long considered to be the gold standard surgical management for localized prostate cancer. Maintaining the integrity of the abdominal cavity by performing the entire procedure in the space of Retzius furthers the goal of minimizing the invasiveness of RARP. The preperitoneal approach has unique advantages. However, it is less frequently used worldwide than the transperitoneal approach. Reasons for this can be mainly attributed to training, unfamiliarity with instrumentation during preperitoneal space creation, and a smaller working space. Ability to perform a preperitoneal RARP is a useful skill to acquire. The procedure is particularly beneficial for patients with significant intra-abdominal incisions from prior surgeries; those in whom preservation of the integrity of the peritoneal surface is important, such as patients on peritoneal dialysis who are waiting to be cancer free for transplantation; and patients who cannot tolerate extreme Trendelenburg position.

This chapter describes our step-by-step technique of preperitoneal RARP based on experience with more than 2000 procedures using that approach for over a decade.

Indications and Contraindications

The indications for performing a preperitoneal RARP are no different from those for an open or laparoscopic radical prostatectomy or transperitoneal RARP.

Relative contraindications include previous laparoscopic inguinal mesh hernia repair via a preperitoneal approach. This renders re-creation of the space very difficult. With increasing experience, challenging surgical scenarios such as a large prostate or high body mass index are managed well irrespective of the approach.

Patient Preoperative Evaluation and Preparation

Fitness to undergo general anesthesia is assessed with a detailed history and examination. Cardiopulmonary conditions that can worsen with hypercarbia are noted.

The patient is maintained on a clear liquid diet after lunch the day before surgery. We perform chemical bowel preparation by administering neomycin and metronidazole the day before surgery. Low-molecular-weight heparin is subcutaneously injected before the procedure. A single dose of intravenous third-generation cephalosporin antibiotic is administered before induction of anesthesia.

Operating Room Configuration and Patient Positioning

The patient is positioned supine on a split leg bed ( Fig. 34-1 ). We use a beanbag wrapped around the shoulders to secure the patient to the bed to prevent sliding in the Trendelenburg position. After successful induction of general endotracheal anesthesia and placement of an orogastric tube, the abdomen is shaved from the umbilicus to the pubic symphysis. Sequential compression devices are placed on both legs, which are abducted to allow access to the perineum. This allows examination of the prostate as well as docking of the patient cart of the robotic surgical system. Three-inch silk tapes are used to secure the legs to the spreader bars. Arms are placed alongside the torso with padding in egg crate foams. Care is taken to ensure that all pressure points are padded to prevent position-related injuries. The vacuum beanbag is activated after wrapping along the sides and shoulders of the patient.

We place a belladonna and opium rectal suppository at the time of prostate examination under anesthesia. This helps control postoperative bladder spasms. The rectal examination allows more accurate clinical staging before surgery. The abdomen is prepared and draped from the nipples to the upper thighs. A 16-French two-way Foley catheter with a 10-mL balloon is used to drain the bladder before the patient is placed in Trendelenburg position (10 to 15 degrees). Because of the natural retraction of the bowels by the peritoneum in this approach, it is not necessary to place the patient in an exaggerated Trendelenburg position, which is often required in the transperitoneal approach.

Extraperitoneal Space Creation and Trocar Placement

A 3-cm incision is made adjacent to the umbilicus and deepened to expose the anterior rectus sheath ( Fig. 34-2 ).

A 1-cm transverse cut is made in the anterior rectus sheath. A purse-string suture is placed over the edges of the sheath in preparation for tightening around the camera trocar later to prevent CO ₂leakage. The medial edge of the underlying rectus abdominis muscle belly is pushed laterally to visualize the posterior rectus sheath. The lip of the S -shaped retractor is repositioned into this opening and used for upward retraction ( Fig. 34-3 ).

A 0-degree 10-mm laparoscope (EndoEYE HD II 10 mm; Olympus, Center Valley, N.J.) mounted on an oval balloon dilator (OMS-XB2 Spacemaker Extraview; Covidien, Minneapolis, Minn.) is gently introduced in the plane above the posterior rectus sheath. Its tip is directed upward and medially toward the pubic symphysis. The accompanying pump is used to inflate the balloon, creating the potential preperitoneal space under vision ( Fig. 34-4 ).

The bladder is separated from its attachments to the anterior abdominal wall. The space of Retzius and the retropubic fat are dissected, bringing the pubic symphysis into view ( Fig. 34-5 ).

Too rapid an insufflation can lead to bleeding from tearing of the inferior epigastric vessels. The anatomic landmarks seen at the end of this step are the inferior epigastric vessels bilaterally and pubic symphysis in the midline. After its deflation, the balloon dilator with the laparoscope is withdrawn and replaced by a smooth 12-mm 15-cm-long trocar (Endopath Xcel dilating tip; Ethicon, Somerville, N.J.) ( Fig. 34-6 ).

CO ₂is connected to the trocar to insufflate the preperitoneal space created previously. The laparoscope is inserted into the trocar. Under direct vision, the preperitoneal space is further developed laterally to allow placement of the assistant and fourth arm trocars. The beveled edge of the trocar is insinuated under the inferior epigastric vessels and used to sweep the peritoneum cephalad. Following an avascular plane between the transversalis fascia below and rectus abdominis muscle above avoids an inadvertent peritoneal opening. A 12-mm assistant trocar is placed 5 cm cephalad to the right anterior superior iliac spine. During introduction of this trocar, care must be taken to redirect the trocar once it has been visualized to avoid injury to the underlying peritoneum. The left and right 8-mm metallic robotic trocars are inserted about 8 to 10 cm lateral and caudad to the camera trocar. These are inserted lateral to the inferior epigastric vessels. We routinely use a hypodermic needle to chart the path of the trocar and prevent inadvertent injury of the vessels. Given that our assistant is left-handed and sits on the patient’s right side, we place our fourth arm robotic trocar on the left side of the abdomen. This 8-mm metallic trocar is placed 5 cm cephalad to the left anterior superior iliac spine. Finally, a 5-mm assistant trocar is placed 5 cm lateral to the umbilicus on the right side ( Fig. 34-7 ). Particular care is required to avoid an inadvertent peritoneal opening during sweeping of the peritoneum as the space for this trocar placement is created.

Adequate spacing between the trocars is imperative to avoid external arm collisions. A Xeroform petroleum dressing gauze (DeRoyal, Powell, Tenn.) is wrapped around the camera trocar to prevent CO ₂leakage. (An alternative is to use a double-sleeved balloon trocar.) The previously placed purse-string suture is tightened around this gauze over the camera trocar. The patient cart is moved between the abducted legs and the robotic arms are docked to the camera and instrument trocars ( Fig. 34-8 ).

We use a 0-degree 10-mm da Vinci scope (Intuitive Surgical, Sunnyvale, Calif.) throughout the procedure. The robotic instruments are brought inside the surgical field under vision (Maryland bipolar forceps, scissors, and ProGrasp forceps [Intuitive Surgical, Sunnyvale, Calif.] in the left, right, and fourth arms, respectively). The 12- and 5-mm assistant trocars are used for passage of sutures, clips, and suction and irrigation as necessary.

Procedure (See )

The bladder takedown step that has to be performed in a transperitoneal RARP is eliminated in the preperitoneal approach. Similarly, potential adhesiolysis from prior operations or from adhesions between the sigmoid and the anterior abdominal wall is not necessary. All remaining steps are identical to a transperitoneal RARP with slight variation in the specimen extraction and closure steps.

Incision of Endopelvic Fascia

The first step to be performed in a preperitoneal RARP is the incision of the endopelvic fascia ( Fig. 34-9 ). With the use of the fourth arm to retract the prostate medially, the endopelvic fascia is incised on both sides along the lateral aspect of the mid prostate.