Transurethral resection of the prostate (TURP) is a common urologic procedure that is used to treat patients with symptomatic benign prostatic hypertrophy (BPH). It is a less invasive approach than traditional suprapubic or retropubic open prostatectomy.
SURGICAL AND ANESTHETIC TECHNIQUE
A resectoscope is inserted through the urethra into the prostate to excise layers of prostatic tissue while preserving the prostatic capsule. Resection is achieved with a diathermy loop via traditional electrocautery or laser vaporization. The conventional approach (M-TURP) uses a monopolar electrode that transmits a high energy electrocautery current from a single-limb electrode through the body to the patient’s grounding pad. Newer B-TURP resectoscopes now utilize bipolar electrodes in which the continuous bidirectional flow of current does not leave the confines of the resectoscope. Several studies have shown lower rates of complications, transfusion, and TURP syndrome with bipolar TURP procedures compared to monopolar currents. In contrast to both these approaches, laser vaporization resectoscopes (L-TURP) enable the actual coagulation and sealing of open prostatic veins during the resection. The laser can vaporize prostate tissue in millimeter layers. Compared to monopolar TURP, using a laser significantly reduces surgical time, blood loss, fluid absorption, and hospital length of stay.
TURP requires the use of a continuous solution for distension, visualization, and irrigation of the bladder and prostate. The ideal solution should be transparent, isotonic, and have nontoxic solutes. Crystalloids such as lactated Ringer’s and normal saline are highly ionized. Since electrolytes can disperse the electric current to surrounding tissues causing burns, the solution should be electrically inert. Plain distilled water, which is very clear and has no electrolytes, can lead to significant intravascular hemolysis when absorbed due to its very low osmolality. Distilled water has been replaced by solutions which are moderately hypotonic, maintain transparency, and cause no significant hemolysis. The most common solutions used today are glycine 1.5% (230 mOsm/L) and sorbitol 2.7%–mannitol 0.54% combination (195 mOsm/L). However, the newer techniques of TURP—bipolar and laser—prevent electrical dispersion and minimize irrigant absorption. Therefore, an electrolyte-containing solution such as normal saline may now be used, which has reduced the morbidity associated with hypo-osmolar solutions.
Anesthesia for TURP may be achieved through either general or neuraxial anesthesia. Studies have not demonstrated any difference in the incidence of postoperative complications (e.g., myocardial infarction, stroke, pulmonary embolus), postoperative cognitive dysfunction, and mortality in patients who received general versus regional anesthesia. General anesthesia has become more acceptable due to the decreased risk of irrigant absorption and TURP syndrome when using the newer bipolar and laser TURP techniques. Spinal anesthesia to T10 provides satisfactory comfort, pelvic relaxation, and the ability to monitor for early symptoms of excessive fluid absorption and bladder or prostate capsule perforation in a conscious patient. Compared to epidural anesthesia, the subarachnoid approach usually ensures block of the sacral (S2–S4) parasympathetic fibers carrying afferent visceral pain sensation from the prostate and bladder.