Surgical Therapy for Prostate Cancer

CHAPTER 46 Surgical Therapy for Prostate Cancer

George P. Hemstreet III, MD, PhD and
Sudhir Isharwal, MD

What are the newest treatments of prostate cancer?

• Proton beam therapy

• High frequency ultrasound (HFU)

What are the 3 major goals of surgery in the order of importance?

• Cancer control

• Preservation of urinary incontinence

• Preservation of sexual function

Describe the arterial blood supply to the prostate and surrounding nearby structures.

The prostate receives its primary blood supply from the inferior vesicle artery, which is the third major branch of the internal iliac artery. It provides small branches to the seminal vesicle and base of the bladder as well as the prostate. The inferior vesical artery terminates into the prostatic artery, which is typically only 1 cm long before it divides into its 2 primary branches: the urethral and capsular vessel groups.

What is the blood supply for the corpora cavernosa?

It is derived from the internal pudendal arteries, which can arise from the obturator inferior vesicle or superior vesicle arteries.

Why are these aberrant branches important?

They are important because they travel along the lower part of the bladder and anteriolateral surface of the prostate and are frequently divided during radical prostatectomy.

What new therapies are on the horizon for improving the function of the striated urethral sphincter, which have the potential for treating incontinence following radical prostatectomy?

• Stem cell therapy

• Adjustable transobturator male system (ATOMS)

What nerve innervates the striated sphincter and levator ani muscles?

The pudendal nerve provides the major nerve supply to the striated sphincter and levator ani muscle groups.

How does one decide when to excise the neurovascular bundle?

Consider if there is a palpable apical lesion, if preoperatively the Gleason score is higher than 6, if the average percentage of poor biopsy core on the side involved greater than 20%, or the percentage of cores with tumor on that side is greater than 33%, or there is an abnormal finding on digital rectal examination on that side.

What is the best way to control the vascular branches to the neurovascular bundle?

It is recommended that small hemoclips be placed parallel to the bundle and that thermal energy (cautery, laser) of any form should never be used on the neurovascular bundle or its branches.

What are the criteria for salvage radical prostatectomy with the goal of successfully eradicating locally recurrent cancer following definitive radiotherapy?

The procedure is reserved for patients in excellent health with a life expectancy of more than 15 years, and patients must have no evidence of metastatic disease. Patients should have unequivocally clinically localized prostate cancer at the time of initial therapy and current prostate biopsies should be negative. There must also be no clinical findings to support metastatic disease.

What percentage of patients are incontinent following salvage prostatectomy and remain tumor-free after 5 years?

Approximately 50% to 60%.

What is the main surgical morbidity associated with radical retropubic prostatectomy and what specific measures help to prevent this complication?

• Thrombophlebitis with pulmonary embolism.

• Prevention is best accomplished by careful positioning of the patient on the operating table, avoidance of venous compression, use of intermittent compression devices with early ambulation, and anticoagulant prophylaxis.

What difference does it make if the seminal vesicles are not totally excised during a radical perineal prostatectomy and what may be one benefit of not removing the seminal vesicles?

• There can be as much as a 40% higher frequency of PSA recurrence if the seminal vesicles are not removed at the time of surgery.

• One benefit is a possible decrease in urinary incontinence because of lack of damage to the pelvic nerves.

What is the current attitude toward the anatomical preservation of the bladder neck during radical prostatectomy?

Randomized trials suggest that there is a small but questionable clinical significance in the early return of urinary control with little or no difference in long-term urinary control. Bladder neck contracture and positive margins in some studies suggest the need to weigh the risks versus benefits of bladder neck preservation.

Why is it likely that there will be a decrease in the number of patients undergoing radical perineal prostatectomy?

The recent US Preventive Services Task Force report strongly suggests active surveillance for individuals with low-risk prostate cancer. This is the group of patients who are candidates for radical perineal prostatectomy because of the infrequency of seminal vesicle invasion, local extension, and nodal involvement.

How effective is orchiectomy?

Orchiectomy results in a reduction of circulating androgens by approximately 97%. Castrate levels of testosterone are achieved within 24 hours of orchiectomy. The hormonal deprivation results in remission of the hormone-dependent prostate tumor growth. Depending upon the Gleason grade of the cancer, the duration of the remission varies, and biochemical failure/hormone-independent tumor growth will eventually occur.

How do the results of brachytherapy compare with surgical therapy?

In one report comparing brachytherapy and radial retropubic prostatectomy in patients matched for similar pretreatment clinical pathological characteristics, the results showed a mean 7-year disease-free survival rate of 84% for surgical extirpation versus 79% for the iodine brachytherapy series. Although there was a proportionately higher probability of nonprogression for brachytherapy, this was not statistically significant. In most studies, brachytherapy has compared favorably to radical prostatectomy in biopsy-confirmed patients post-treatment.

How are the lymph nodes assessed for metastatic disease?

Although CT scan may be used to evaluate for lymphadenopathy, one cannot differentiate pathologic from nonpathologic nodes if they are < 1.5 cm in size. Thus, computed tomography is both nonspecific and nonsensitive. To absolutely rule out metastatic disease of the lymph nodes, a lymphadenectomy is required.

What are the options for pelvic lymphadenectomy?

If the patient is undergoing radical retropubic prostatectomy, a lymphadenectomy may be performed simultaneously and the lymph nodes can be sent for frozen section analysis to rule out micrometastases. Alternatively, a laparoscopic pelvic lymph node dissection or a minilap lymph node dissection may be performed.

How is a laparoscopic lymph node dissection performed?

Laparoscopic lymph node dissection can be performed transperitoneally or through a preperitoneal approach. The pelvic lymph nodes are removed, and the tissue is sent for analysis.

What are the boundaries for lymph node dissection?

The distal limit of the dissection is the node of Cloquet located in the femoral canal. The proximal limit of the dissection is the bifurcation of the iliac vessels. The superior limit of the dissection is the external iliac artery, the lateral limit is the pelvic sidewall, and the inferior limit is the obturator vessels. Thus, all the lymph nodes are dissected off of the external iliac vein, the pelvic sidewall laterally, and the obturator nerve and vessels.

Why is laparoscopic pelvic lymph node dissection so infrequently performed now when it was so popular in the early 1990s?

The surgery was originally intended for patients with a high likelihood of lymphatic metastatic disease where a radical surgery or definitive radiation therapy could be avoided if positive lymph nodes were identified preoperatively. Typical patients would have elevated PSA levels (at least 10 or more) and Gleason sums of 7 or higher. Better understanding of PSA and the use of nomograms like the Partin tables have largely made the laparoscopic pelvic lymph node dissection unnecessary.

What are the complications of pelvic lymph node dissection?

The most common complication is lymphocele formation. Lymphocele formation can be minimized by clipping or tying feeding lymphatics as coagulation of lymphatics can result in postoperative lymphatic leakage. Damage to the external iliac vein, obturator vessels, and obturator nerve can also occur during pelvic lymphadenectomy.

What are the different methods of radical prostatectomy?

• Radical retropubic.

• Laparoscopic.

• Perineal.

How is the patient prepared for radical prostatectomy?

The patient should have adequate cardiac and pulmonary function. If there are any risk factors of cardiopulmonary disease, the patient should be optimized prior to surgery. Screening tests for coagulopathy are mandatory. Preoperative determination should be made of the patient’s hemoglobin, hematocrit, and electrolytes. Although the risk of rectal injury is low, patients should undergo bowel prep prior to surgery.

Should the patient donate autologous blood?

This depends on the surgeon’s experience. If the surgeon historically loses more than 500 mL of blood during a radical prostatectomy, it is reasonable to offer the patient the option of donating autologous blood. The blood is commonly donated within the month before surgery. This bears substantial cost, but decreases the risk of a transfusion reaction or a transfusion-associated morbidity.

Are antiembolism precautions necessary for radical prostatectomy/pelvic lymph node dissection?

Many of the risk factors for deep vein thrombosis (DVT) and pelvic thrombosis are present: general anesthesia, blood loss, pelvic surgery, and possibly a hypercoagulable state. Lower extremity sequential compression devices and antiembolism stockings are commonly employed to help minimize pooling of blood in the deep veins of the legs. This should be used with medical anticoagulation such as subcutaneous heparin or Lovenox. However, risk of bleeding should be considered when starting pharmacological DVT prophylaxis.

What is the positioning for the radical retropubic prostatectomy?

The radical retropubic prostatectomy is performed through a midline infraumbilical incision extending from the umbilicus to the pubic symphysis. The patient is placed supine or in a low lithotomy position with the kidney rest or a rolled towel just above the sacrum with the table slightly hyperextended. During the procedure, reverse Trendelenburg may be helpful in visualizing the apex of the prostate.

Describe the approach to the prostate in a retropubic prostatectomy.