Radical Surgery in Urology

Radical surgery is becoming commonplace in the urologic suite with the introduction of radical nephrectomy, radical cystectomy, and radical retropubic prostatectomy. Common features are that the procedures tend to be lengthy, may be associated with sudden and significant blood loss, and require special attention to preservation of renal function. With radical nephrectomy, significant cardiorespiratory changes attendant to the flank position are a concern. Respiratory changes include decreases in thoracic compliance, tidal volume, vital capacity, and functional residual capacity. Dependent atelectasis is common and may lead to hypoxemia. Pneumothorax may occur and can have significant respiratory and hemodynamic consequences intraoperatively. It is not uncommon to see a decrease in blood pressure when the kidney rest is raised. This decrease is usually due to compression of the inferior vena cava. In addition, hepatic encroachment on the vena cava and mediastinal shift may further reduce venous return and stroke volume. Cervical plexus, brachial plexus, and common peroneal neuropathies may occur as a result of stretch or compression of nerves in the lateral position.

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Radical Nephrectomy for Renal Cell Carcinoma ( Table 54-14 )

The most common malignancy of the kidney is renal cell carcinoma; 85% to 90% of all solid renal masses are renal cell carcinoma.^[213] Because renal cell carcinoma is refractory to chemotherapy and radiation therapy, surgical excision is the only potentially curative treatment of localized disease. More recently, resection of the ipsilateral adrenal gland has been reserved for patients with large upper pole lesions or when the adrenal gland is enlarged or appears abnormal.^[214] Partial nephrectomy (nephron-sparing surgery) is considered for patients with small lesions or bilateral tumors or for those at risk because of other diseases such as diabetes or hypertension.^{[213] [214] [215] [216]} In 5% to 10% of patients, the tumor extends into the renal vein and the inferior vena cava and right atrium. Tumor extension into the inferior vena cava and atrium occurs more frequently with right-sided renal cell carcinoma. Several problems can occur in these patients, ranging from circulatory failure as a result of complete occlusion of the vena cava by tumor to acute pulmonary embolization of tumor fragments during surgery. To operate on these patients safely, the extent of the lesion must be defined preoperatively. Cardiopulmonary bypass is required in these cases to prevent tumor embolization; it may also be necessary in some with extension into the upper portion of the hepatic vena cava or when venous return is significantly compromised. Right heart catheterization is potentially hazardous because of the danger that a part of the tumor may be dislodged and embolize. Some use a central venous pressure catheter inserted through left internal jugular or external jugular vein so as not to place it beyond the superior vena cava. Central venous pressure in such cases may not reflect intravascular volume accurately because venous return through the inferior vena cava is impaired by the thrombus. This decrease in venous return also predisposes the patient to hypotension during induction of anesthesia. Furthermore, venous obstruction leads to dilation of the epidural veins and the development of abdominal wall and retroperitoneal collaterals. Again, the emphasis is on appropriate preoperative preparation, which is

TABLE 54-14 -- Anesthetic implications of radical nephrectomy for tumors

85%–90% are for renal cell cancer

5%–10% extension to the IVC and right atrium

Large-bore IV access, A-line, IJV line (preferably on the left side if the IVC is involved)

Paraneoplastic syndrome

Hypercalcemia, eosinophilia; increased prolactin, erythropoietin, and glucocorticoids

Men > women

Chronic smoking history usually associated

CAD, COPD

Renal failure

CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; IJV, internal jugular vein; IV, intravenous; IVC, inferior vena cava.

possible only when the full extent of the lesion has been defined.^[216]

Radical Prostatectomy ( Table 54-15 )

Localized prostate cancer is treated by either radiation therapy or radical prostatectomy. Radical prostatectomy is now more commonly used because of routine prostate-specific antigen testing in men older than 50 years and popularization of the nerve-sparing surgery that reduces the risk of impotence. Though originally described in 1905 by way of the transperineal approach, the retropubic approach is mostly used nowadays. The prostate, the ejaculatory ducts, the seminal vesicles, and part of the bladder neck are removed along with the pelvic lymph nodes. Generally, the procedure is performed by open laparotomy, but laparoscopic and robotic surgery are being used in some centers. The most common intraoperative problem is hemorrhage and massive blood loss requiring blood transfusion. Autologous predonation, the use of recombinant erythropoietin preoperatively, and intraoperative isovolemic hemodilution are commonly practiced to reduce the patient's exposure to allogeneic blood. The routine use of these practices, their indications, and the need for transfusion in these patients have been questioned by some. Early postoperative complications, including DVT, pulmonary embolism, hematoma, seroma, and wound infection, occur in 0.5% to 2% of cases.^[217] Death within 30 days has been reported by several centers to occur in approximately 0.2%.^[217] Late complications include incontinence, impotence, and bladder neck contracture. ^[218] Patients undergoing radical prostatectomy are placed supine in the Trendelenburg position with the back extended, which places the pubis above the head. Air embolism from the prostatic fossa as a result of a gravitational gradient between the prostatic veins and the heart has been reported. ^[219]

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Comparison of Anesthetic Techniques for Radical Prostatectomy

Epidural anesthesia, spinal anesthesia, general anesthesia, and combined epidural and general anesthesia have been used for this surgery. For the epidural component of combined techniques, either a thoracic or lumbar approach to anesthesia or analgesia has been used, and either spontaneous or intermittent positive-pressure ventilation (IPPV) has been used for the general anesthesia component. Many investigators have reported their findings in comparing the three anesthetic techniques for radical retropubic prostatectamy,^{[220] [221] [222] [223]} and the following trends emerge.

Intraoperative blood loss is significantly less if epidural anesthesia or a combined epidural and general anesthetic with spontaneous ventilation is used. In one study, blood loss in the general anesthesia and the combined anesthesia group with IPPV was significantly more than in the epidural anesthesia group despite little difference in arterial pressure among the three groups.^[220] It was postulated that the increased venous pressure as a result of IPPV was the most likely cause of increased bleeding in the general and the combined anesthesia groups during radical prostatectomy. Previous studies had demonstrated that central and peripheral venous pressure was lower in patients during spontaneous ventilation under epidural anesthesia or combined epidural-general anesthesia than in with patients receiving IPPV during general anesthesia.^[224] Epidural anesthesia alone or when added to a general anesthetic decreases postoperative hypercoagulability, thereby decreasing the risk of thromboembolism.^{[225] [226] [227]} The preemptive analgesia provided by the epidural block decreases postoperative pain and analgesic requirements.^{[228] [229]} Homeostasis of neuroendocrine responses may be better maintained with regional block than with general anesthesia. Recovery of bowel function occurs faster with epidural anesthesia than with general anesthesia, although it does not result in earlier hospital discharge of the patient.^[230] The length of stay and the cost of hospitalization can be decreased with the judicial use of epidural anesthesia and established clinical pathways.^{[231] [232] [233] [234] [235]} In one study, 80% of patients were satisfactorily discharged after 1 day, and the mean length of stay was 1.34 days.^[236]

Although some studies report better outcomes with epidural anesthesia than with general anesthesia, others fail to support such results. The divergent findings in these studies comparing three anesthetic techniques may be a consequence of small numbers of subjects in many studies, difference in design (retrospective, prospective, controlled, randomized, etc.), the use of different techniques (e.g., thoracic versus lumbar epidural block), the use of spontaneous ventilation versus IPPV, and use of local anesthetics with or without opiates. Local practices are based on the preferences of the urologist, the anesthesiologist, and the patient, and these preferences assume precedence over most everything else.

Recent Developments and the Future of Radical Prostatectomy

With the increasing use of laparoscopic radical retropubic prostatectomy and the introduction of robotic surgery (see Chapter 66 ) for this procedure, anesthetic techniques will change. For example, epidural anesthesia alone or spontaneous ventilation may no longer be an option. The outcomes, we hope, will improve, but we might trade newer complications for the existing ones. At present, long-term benefits of the laparoscopic approach over open radical prostatectomy have not been demonstrated.^[236]

Postoperative pain (see Chapter 72 ) in these patients is well controlled with patient-controlled analgesia, epidural analgesia, or a combination of ketorolac and rescue opiates.