Radical prostatectomy - enter robotics

Treatment options for localized prostate cancer are multiple, ranging from active surveillance to surgical removal of the prostate (radical prostatectomy) to external beam radiation therapy, brachytherapy, high-intensity focused ultrasound and cryotherapy. The decision-making process is based on a combination of different factors including patient age and medical status, PSA level, tumour stage assessed by digital rectal examination, number of positive biopsies, as well as their Gleason score. To allow for a tailored approach, patients need a significant amount of information with emphasis on the advantages and drawbacks of each of these methods. The goal of this article is to describe how radical prostatectomy has evolved over the years from an open technique to a robotic approach.

Removing the prostate gland constitutes a technical challenge due to its deep location in the male pelvis and to some important anatomic structures surrounding it: the dorsal vein complex situated at the apex of the gland behind the pubis, providing venous drainage to the prostate; the striated ureteral sphincter at the level of the urethra, which is mainly responsible for urinary control; the neurovascular bundles running posterolaterally on both sides of the prostate capsule, which are critical to male potency.

Open radical retropubic prostatectomy

Radical prostatectomy consists of completely removing the prostate gland, together with the adjacent seminal vesicles, and reconnecting the bladder neck to the urethra. In some cases, the operation might also include taking out some lymph nodes in the region.

Since the pioneering work of Dr. Patrick Walsh in the early 1980s, the possibility of completely removing the prostate gland without significant complications has become widely accepted. This so-called anatomic approach to radical prostatectomy involves:

• precise control of bleeding from the dorsal vein complex
• accurate dissection of the apex (tip) of the gland to avoid injury to the sphincter
• if indicated, preservation of the neurovascular bundles to preserve potency

The success of the operation is mostly measured by the surgeon’s ability to eliminate the entire tumour (negative margins) and to maintain the patient’s continence and potency.

The operation is performed under general, spinal or epidural anesthesia. The usual incision is a midline lower abdominal opening extending from the pubic bone to the umbilicus (navel), although a horizontal suprapubic incision is also possible.

The operation lasts approximately two and a half hours. Blood loss averages 700 ml, with a transfusion rate of 25 percent. The urethra is reconnected to the bladder neck with five stitches, and a bladder catheter has to stay in place for at least two weeks. Hospital stays vary in different centres but are usually four days; convalescence extends for six weeks. The effect on continence is greatly influenced by the patient’s age and body mass index, but full continence recovery can be as high as 90 percent at one year. The return of potency, which depends directly on a man’s age, preoperative sexual status and preservation or excision of the neurovascular bundles during the operation, can be as great as 85% if both bundles are spared; recovery can take 18 months or longer.

Laparoscopic radical prostatectomy

The development in the early 1990s of minimally invasive surgery has dramatically changed the approach to radical prostatectomy. Surgeons from Europe first hypothesized that the magnification provided by a video camera — inserted through a 1 cm umbilical incision — could allow for even more precise dissection of the prostate while reducing pain related to the traditional procedure. With this technique, the patient’s abdomen is inflated with carbon dioxide (CO₂) to allow for working space, and four to five tiny incisions are made in the lower abdomen, through which the appropriate surgical instruments are inserted. Because of the compressive effect of the CO₂ and better visualization, the risk of bleeding, and consequently of transfusion, is much lower (average blood loss is 400 ml). Since refastening of the bladder neck to the urethra can be made immediately watertight, the bladder catheter can be removed as early as four to seven days after the operation. Postoperative pain as well as hospital stay (two days) and convalescence (four weeks) are significantly reduced. Reported long-term continence and potency results are at least equivalent to those observed with open surgery. The major drawback of laparoscopic surgery is the significant learning curve required for the surgeon to master control of the rigid instruments in a two-dimensional environment. Because of this, laparoscopic radical prostatectomy has not gained widespread acceptance despite its significant advantages for the patient.

Robotic-assisted laparoscopic prostatectomy

Since 2000, the introduction of the da Vinci® Robotic Surgical System has further, and dramatically, driven the use of the laparoscopic approach for radical prostatectomy. This system is based on three components:

• a surgical cart with four arms that are connected to a telescope and to three surgical instruments
• a console where the surgeon sits comfortably and manipulates two joysticks as well as five foot pedals that control the instruments
• the telescope — a cart with two video cameras providing a three-dimensional (3D) view

The major advantage of this technology is a 12-time magnified 3D visualization with high definition feature providing an outstanding image of every possible anatomic detail of the man’s pelvis. The second key advantage of the da Vinci robot is the presence of miniature wristed articulating instruments (Endowrist® technology) with seven degrees of freedom (compared to four with conventional laparoscopy), allowing multiple options for dissecting the prostate gland. Together, these features allow for improved dexterity, precision and control during the operation. The drawback? Despite the amazing visual clues, tactile feedback is still missing and should be included in future versions of this robotic system.

Widespread and rapid acceptance of this technology has been made possible by its genuinely intuitive aspect and the associated shorter learning curve for surgeons. Therefore, even surgeons inexperienced with laparoscopy have been able to adapt their open surgical skills to a laparoscopic environment using the robotic interface.

The average operating time is two hours and the average blood loss is 150 ml, with only a three percent risk of blood transfusion. Hospital stay can be as short as one day and bladder catheter time is usually seven days. Cancer control is just as good with robotic surgery as with the classical open operation. In terms of functional results, it seems that the robotic technology might allow for earlier recovery of continence compared to the open approach. The results for potency are at least equivalent to the best results observed with both the open and laparoscopic approaches.

More than 1,000 robotic systems are in active use around the world, mostly in the United States. In the US in 2001, 250 robotic prostatectomies were performed; in 2007, the number rose to 50,000. Robotic technology is now available in nine Canadian centres: two in Montreal, two in Toronto, two in London, two in Edmonton and one in Vancouver. Cost represents the major drawback to its widespread diffusion. The system costs $2.3 million (US) plus $160,000 per year for maintenance and $2,300 each case for the purchase of disposable instruments. Most of the robotic systems available in Canada have been acquired through generous philanthropic donations.

More precision, fewer effects

The improved 3D vision, surgical precision and exposure made possible with the use of robotic-assisted radical prostatectomy have translated into fewer health consequences for the patient. So far, cancer control and functional results of the robotic approach are at least as good as the best results observed with the open and pure laparoscopic approaches. Whether the robotic technology leads to even better outcomes requires more evidence from long-term multicentre studies. Nevertheless, the intuitive aspect and short learning curve of the robotic operation have already won over many surgeons around the world. No doubt, further improvements in technology will continue to enhance its widespread acceptance.

Maurice Anidjar, MD, PhD, is a Urologist at the McGill University Health Centre — Royal Victoria Hospital and Jewish General Hospital, and Assistant Professor in the Division of Urology at McGill University.