The Steps Involved in a Robotic Prostatectomy

What are the steps involved during our “tailored” robotic prostatectomy?

Posterior dissection of the seminal vesicles and the prostate

The seminal vesicles are cystic structures attached to the prostate that store and add nutrients to semen. The seminal vesicles are always removed with the prostate during surgery. A posterior approach enables energy-free and traction-free dissection of the nerve bundles that run along the sides and tips of the seminal vesicles.

The posterior approach also allows excellent visualization of large or asymmetric seminal vesicles, which can be very complicated in an anterior approach. Additionally, this approach lets us bypass a large median lobe (a protrusion of the prostate into the bladder) without compromising visualization. 

Developing the space of Retzius and anterior prostate dissection with sparing of the Endopelvic Fascia

This step drops the bladder and the prostate from the abdominal wall. It allows the surgeon to directly visualize the anterior prostate and the dorsal vascular complex. By sparing the Endopelvic fascia, an Intra-fascial dissection is more likely to be successful. See neurovascular bundle dissection below for more details. 

Division of the prostate from the bladder by the bladder-neck sparing technique to preserve the internal sphincter mechanism

Two layers of bladder muscle fuse together the bladder and prostate in addition to fatty tissue. This area includes the internal urinary sphincter, which is composed of muscle fibers that play a role in the subconscious control of urinary function. In most patients, preservation of the bladder neck sphincter mechanism can result in early urinary continence. Proper preservation can also reduce the risk of strictures or scars at the bladder neck, commonly called bladder neck contractures.

If the bladder neck is not spared, the resulting large opening may require a time-consuming reconstruction to narrow it. Larger openings also require a longer suture line and may therefore be more susceptible to urine leakage from the anastomosis. Given these factors, and assuming no biopsy features indicate bladder neck involvement or a large median lobe, we always strive to preserve the bladder neck. 

Dissection of the lateral prostatic fascia and sparing of the neurovascular bundles (NVB)

The nerve bundles carry neural information and blood flow into the deep pelvis. These structures are critical for both erections and urinary control after surgery. Multiple studies to date have shown a direct relationship between the degree of nerve sparing and post-operative potency and urinary control.

Contrary to what most patients believe, nerve sparing is not an all-or-nothing concept. Depending on the extent of the cancer, the nerve dissection can be individually tailored to the patient and their cancer.

Many factors come into the decision but include the risk of extracapsular extension based on pre-operative nomograms/risk-tables (link to separate section/post), the results of pre-operative T3 MRI of the prostate (link so section), the findings of a rectal exam under anesthesia, intra-operative findings and the ease of “peeling” the bundles away from the prostate.

The precision and dexterity needed to dissect the nerve bundles away from the prostate is similar to what is required to “peel” the skin off a tabletop grape (link to video).

Our goal is to remove all prostate and cancerous tissue clearly, but as important as a goal is to leave all non-prostate tissue as it was before the surgery. Many times, surgeons use the terms extrafascial, interfascial, and intrafascial to describe different techniques to dissect the prostate and the nerve bundles. 

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  Extrafascial: This is also known as non-nerve-sparing or wide-excision dissection. When there is either high suspicion that the tumor has penetrated the capsule wall deep into the extracapsular fatty tissue or is involving the nerve bundle itself, this may require us to resect the nerve bundle altogether with the prostate.
  
  Typically, a preoperative MRI can determine the extent of involvement. In this type of dissection, the endopelvic fascia is incised deep near the levator ani muscles to carry out this type of dissection. In patients who are not interested in nerve preservation due to baseline erectile dysfunction, a wide excision may not be critical.
  
  However, even in patients with clear evidence of extracapsular involvement, we may be able to do a graded dissection and spare some of the neurovascular bundle on the side affected with cancer in hopes of maximizing post-surgical potency. We use intra-operative frozen sections, sending tissue from the edge of the dissection for a preliminary assessment of any tumor at the margin and then guiding our dissection based on those results.
  
  We are also working on a novel technology that will enable real-time identification of prostate tumors using fluorescent dyes that target cancer and near-infrared imaging, similar to what we have pioneered in kidney cancer surgery (link to Firefly). Although we are currently evaluating this technology in an animal model, we hope to apply it clinically soon and recruit patients for a clinical trial.  
• Interfascial dissection: The endopelvic fascia is incised, and the neurovascular bundles are spared posterolaterally to take some of the tissue around the prostate (periprostatic fascia) with the specimen. The component of nerves and vessels that can sometimes be found on the anterior aspect of the prostate is therefore not spared. As noted above, the clinical extent of the tumor affects whether we decide to do this type of graded dissection.  
• Intrafascial dissection: This is the most delicate and precise type of dissection. Think of this as a custom-made, very “fitted” type of dissection. In this type of dissection, the endopelvic fascia, the neurovascular bundles, the periprostatic fascia, and Denonvillier’s fascia are all spared and left intact. The plane of dissection is directly guided on top of the prostate capsule. By preserving all these structures, we maximize the patient’s chance of regaining erectile function and urinary control after surgery.  

Control of dorsal vascular complex (DVC)

• As its name implies, the DVC contains an array of both veins and arteries that carry and drain blood from the penis. Because so much blood flows through this structure, inadvertent injury can cause significant bleeding. The higher amount of blood loss associated historically with open prostatectomy techniques was related directly to this point of the procedure.
  
  Fortunately, with the use of CO2 gas in laparoscopic and robotic surgery, venous bleeding from the DVC is no longer a major issue, as the gas provides passive pressure and prevents oozing from this area. Two methods are used to control the DVC: either suture ligation or endoscopic stapling.
  
  One of our preferred control methods is endoscopic stapling. As we have previously published, endoscopic stapling allows for a consistent, efficient, and reliable method for getting control without risking a positive margin at the apex of the prostate. 

Preparation of Apical Urethra – preserve length and muscle fibers

• Prostates come in all sizes and shapes. Some are smaller, some are bigger. Most variation in shape is seen at the apex. The apical prostate surrounds the urethra near the external sphincter complex. The goal at this point of the operation is to achieve a long and thick urethral stump that will subsequently be reconnected to the bladder neck.
  
  There is a fine line between dissecting too deeply (the levator muscles and the external sphincter complex can be inadvertently damaged) and too shallowly (risk leaving prostate tissue behind). 

Posterior Reconstruction

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  Also known as a Male sling, Rocco reconstruction, or Rhabdosphincter reapproximation. This technique provides posterior support for the sphincter complex, similar to a hammock, and prevents the urethra from slipping further down into the pelvis during activity, which may lead to leakage during coughing, sneezing, or laughing.
  
  The reconstruction also brings the bladder down into a supported position, removing tension on the completed urethra-bladder anastomosis. Most experts agree that this type of reconstruction leads to shorter recovery times for urinary control. 

Urethrovesical anastomosis

• The goal at this point of the procedure is to create a watertight and tension-free connection between the urethra and the prostate. One of the most significant advancements in our practice has been the ability to use a barbed suture (V-Loc, Covidien) that maintains the reapproximated ends without allowing gaps between the tissue edges. As a result, for years now, we have avoided using any post-operative drains unless we are dealing with a very large bladder neck or a reconstructed bladder neck. 

• Although pre-operative CT or MRI may not show evidence of regional lymph node involvement, these imaging tests are only about 80% accurate. The decision to identify and remove the lymph nodes that drain the prostate during prostatectomy is made on an individual basis. We calculate the risk of lymph node involvement based on widely available nomograms and risk calculators such as D’Amico criteria, Partin Tables, CAPRA score, or MSKCC calculator.
  
  Low-risk patients (for example, those with PSA < 10, Gleason 6, or clinical T1c) do not benefit from a lymph node dissection. Intermediate-risk patients and High-risk patients, on the other hand, may benefit from a lymphadenectomy. It is believed that an extended lymph node dissection (in both lymph node negative and positive patients) may lead to the removal of undetected micrometastases, and therefore improve the survival of patients undergoing prostatectomy.
  
  A growing body of evidence suggests that the more lymph nodes removed, the more beneficial the procedure. However, no uniform consensus exists on the limits of the dissection boundary or the minimum number of lymph nodes to remove. Historically, the detection of suspicious lymph nodes at the time of radical prostatectomy led many surgeons to abandon the operation with the belief that regional lymph node involvement was a sign of widespread metastatic disease and therefore associated with poor prognosis.
  
  Patients would subsequently be referred for treatment with hormones and/or radiotherapy. However, there have been several recent studies showing very reasonable cancer-specific survival rates even in patients with lymph node-positive disease at the time of radical prostatectomy. A recent publication from the European Journal of Urology analyzed the Munich cancer registry and found that patients with lymph node-positive disease who did not have their operation aborted, on average, had a 20% improvement in survival compared to those who had their operation aborted.