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Open Versus Robotic Prostatectomy
Introduction
Prostate cancer is the most common solid malignancy among men in the United States and the second most common cause of death, with an estimated 233,000 new cases and 29,480 deaths in 2014. The “gold standard” for surgical management for prostate cancer has been a radical prostatectomy, dating back to the first perineal prostatectomy described by Hugh Hampton Young in 1905. Several advances have been made with the procedure to improve oncological outcomes, including adjusting to the retropubic approach. To optimize and address issues with the retropubic radical prostatectomy (RRP), including short- and long-term complications, as well as oncological, continence, and potency outcomes, there was, and continues to be, a demand for a better understanding of the local anatomy and physiology of the prostate and periprostatic area. Pioneers in this work include Reiner and Walsh with their description of the dorsal venous complex, Oelrich’s work defining the importance of the striated sphincter to improve continence, and Walsh and Donker, who better defined the neurovascular bundles to assist with improving postoperative potency.
To reduce the invasiveness of the procedure, technological advances have been introduced to incorporate laparoscopic and robotic-assisted laparoscopic techniques. Schuessler et al. first described their experience with performing a laparoscopic prostatectomy (LP) in 1997. Several other authors have contributed to standardizing the LP technique. The laparoscopic procedure proved to have a steep learning curve with reduction in motion and two-dimensional vision, leading to limited acceptance as an improvement on the widely practiced use of the RRP. The introduction of robotic instrumentation with the daVinci Surgical System (Intuitive Surgical Inc., Sunnyvale, CA) enabled surgeons to overcome the challenging technical learning curve to LP. In the United States, Menon et al. standardized the technique for robotic-assisted laparoscopic radical prostatectomy (RALRP), which subsequently led to widespread acceptance in Europe and the United States. The technology involved with the system is the driving force in acceptance as it provides surgeons with improved optics (three-dimensional) and instrument controls that have less-restrictive movements, thus mimicking surgeons’ hand movements with increased accuracy. Concurrently, it has reduced the learning curve associated with the minimally invasive approach to radical prostatectomy and many surgeons perceive an improvement in functional results without sacrificing early oncologic outcomes.
As time has allowed for data sets to mature there have been more systematic reviews to compare the perioperative, functional, and oncological outcomes between the minimally invasive approaches (LRP and RALRP) to the traditional approach (RRP). RP has become the preferred technique for managing prostate cancer, and with the introduction of LRP and RALRP there has been wide acceptance around the world. Review of the literature provides support for advantages and disadvantages associated with each approach. The discussion in this chapter will endeavor to highlight the differences between RRP and LRP/RALRP and provide information for the surgeon and patient to hold a fruitful discussion to determine the best approach for that patient.
Surgical technique
From a technical perspective, the traditional open approach (RRP) is done through a small midline infraumbilical incision down to the symphysis pubis allowing for exposure of the pelvis, access to the prostate and pelvic lymph nodes. The procedure is done under direct visualization of the tissue with the surgeon being able to appreciate the tissue by touch. The laparoscopic and robotic approach use smaller incisions for the camera and working ports, and the surgeon relies on perceived haptic feedback to appreciate the tissues. Another advantage to the minimally invasive techniques is the visualization of the tissues and the positive pressure provided by the pneumoperitoneum used for insufflation as it limits blood loss. Some of the limitations of the LRP were overcome with the development of the RALRP, especially with the degrees of freedom with the instruments, improved ergonomics, and visualization. A disadvantage to the RALRP is that an experienced bedside assistant is paramount and cost.
Determining Approach
The most appropriate surgical approach should be dictated by surgeon experience/expertise, patient anatomical factors (e.g., body habitus, pelvic anatomy, prostate size), treatment-related factors (e.g., prior abdominal/pelvic surgery, radiation therapy), comorbid illness, and patient preference. Essentially the indication for any of the available procedures is the same: localized disease without clinical or radiographic metastatic disease. With respect to comorbid illness, severe cardiopulmonary compromise, uncorrectable bleeding diatheses, and severe liver dysfunction are relative contraindications to both procedures. For minimally invasive approaches, the need for pneumoperitoneum and steep Trendelenberg positioning may be associated with increased difficulty in adequately ventilating patients (causing hypercarbia and acidosis) compared to RRP. Patients with complex pelvic surgery, large prostate size (e.g., >100 g), morbid obesity, prior pelvic radiation will increase the technical challenge to the open and minimally invasive approaches. Extreme obesity may present challenges for the open and minimally invasive approaches. For RRP, adequate exposure of the surgical field may be challenging in the severely obese patient. For LRP/RALRP, extreme obesity presents a lesser challenge for the technical aspects of the surgery but may cause anesthetic issues related ventilation and steep Trendelenberg positioning. Ahlering et al. found that obese patients (BMI >30) had worse baseline urinary and sexual function, and slower return to baseline when compared to nonobese patients. At 6 months, 91.4% of nonobese patients were pad-free, while 47% of obese were able to achieve pad-free urinary continence ( p ≤ 0.001). Prior abdominal surgery is not a contraindication for LRP/RALRP but severe adhesions caused by extensive abdominal surgery, prior peritonitis, or prior trauma may hamper efforts to perform the operation and significantly prolong the duration of the surgery if extensive enterolysis is required, which may also contribute to postoperative ileus and increase the risk of bowel injury. By virtue of its extra-peritoneal approach, RRP avoids these potential problems. Likewise, RRP may afford some advantages in patients with prior colorectal reconstruction, such as an ileal J-pouch. Extraperitoneal RALRP has also been described and mastered by some surgeons and this may also circumvent these problems. Access to the pelvis may also be limited by previous pelvic surgery, including hernia repairs, which may obliterate the space of Retzius, making RRP more challenging. Some surgeons may prefer to approach the prostate via a transperitoneal approach using RALRP for this reason. The extraperitoneal approach has the advantage of leaving the peritoneum as a natural barrier keeping the bowel away from the operative field and urine out of the peritoneal cavity should there be an anastomotic leak. For extraperitoneal RALRP, a limiting factor is the reduced working space, as well as tension on the vesicourethral anastomosis as the bladder is not mobilized to the same extent as a transperitoneal approach. There are also some reports of high CO 2 absorption with extraperitoneal versus transperitoneal approach requiring higher minute volume to compensate for the hypercarbia and associated acidosis. Most series do not show a difference, or very little difference in outcomes when comparing the extraperitoneal to the transperitoneal.
Management of Dorsal Venous Complex (DVC)
The dorsal venous complex (DVC) can be the source of greatest blood loss during the procedure. Blood in the field will also make the meticulous and precise dissection of the neurovascular bundles (NVB) much more challenging. Variation on approach to the DVC such as with an antegrade progression where it is suture ligated but not divided until later in the procedure when the bladder neck dissection has been done. At the time that the bladder neck is divided, the prostatic pedicles are then identified and ligated. With the pedicles ligated, the blood supply to the prostate is controlled. The NVB are dissected from between the prostate and the levator fascia, and any perforating vessels are controlled for satisfactory hemostasis as the dissection is carried toward the prostatic apex. With this approach the NVB is almost completely dissected prior to reaching the apex of the prostate and the DVC is divided, always mindful to limit any thermal injury to the NVB. In 1998, Walsh described a retrograde approach to help preserve the NVB with more accuracy. An initial step in the procedure is to suture ligate the DVC and then divide it and the urethra. The prostate is released from apex to base as the attachments to the levator fascia are taken down and thus releasing the NVB as the dissection is completed. The prostatic pedicle is controlled by ligation and the bladder neck can be divided. Last, the prostatic pedicles are secured with large hemoclips and the bladder neck divided. This approach is favored by some due to early control of the blood supply to the prostate and thus limit excessive blood loss during the procedure. Yet others prefer early ligation and division of the DVC to allow for a meticulous apical dissection, in efforts to limit the chance for positive margins and the preservation of the striated sphincter. The approach is up to the surgeon’s discretion; an absolute is maintaining a bloodless operative field and preserving the NVB as best as possible for optimal urinary and sexual function without compromising oncological outcomes. The use of electrocautery should be judicious with some authors preferring the use of bipolar electrocautery in RALRP to control any penetrating prostatic vessels.
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