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Benign prostatic hypertrophy is an extremely common malady in men age fifty and over, causing variable degrees of bladder outlet obstruction. The etiology is unknown, but alterations in the hormonal balance associated with aging have been instigated. PATHOLOGY The prostate is a fibromuscular organ located at the base of the bladder. In pathological hypertrophy, multiple fibroadenomatous nodules develop in the periurethral region of the prostate. These nodules peripherally displace the fibromuscular prostate. This process may affect the lateral walls of the prostate or may include the inferior margin. Histologically, the tissue is composed of both fibrous and glandular elements. As the disease process progresses, the lumen of the prostatic urethra becomes progressively distorted, compromising urinary flow. The bladder wall undergoes morphic changes including hypertrophy, trabeculation, and diverticula formation. Cystitis frequently occurs secondary to stasis resulting from incomplete bladder emptying. With prolonged obstruction, the upper urinary tract becomes progressively involved. Calculi formation, hydroureter, hydronephrosis, and compromised renal function may ensue. DIAGNOSIS Signs and Symptoms: The patient may complain of progressive urinary frequency, urgency, and nocturia. Hesitancy, terminal dribbling, and overflow incontinence are frequent complaints. Occasionally, intermittent bouts of complete obstruction may occur. Rectal exam usually reveals a prostate that is firm, enlarged, and rubbery in consistency. There is, at times, loss of the median furrow. Diagnostic Tests: IVP may reveal upward displacement of the distal ureters and a defect of the base of the bladder, signs compatible with prostatic hypertrophy. The post void cystogram usually reveals residual urine. Cystography best demonstrates the extent of prostatic hypertrophy. TREATMENT Surgical excision is the definitive treatment. Four approaches have been described: 1) Suprapubic prostatectomy; 2) perineal prostatectomy; 3) retropubic prostatectomy; 4) transurethral prostatectomy. Transurethral prostatectomy (TURP) is usually the approach of choice, particularly in glands less than 45 gm. It is performed by electrosurgery through a cystoscope. Indications for Surgery:(1) Table 1 lists the absolute indications for surgery. The most common absolute indications are symptoms of bladder outlet obstruction and hyperirritability. Symptoms of bladder outlet obstruction include decrease in force and caliber of the urinary stream, hesitancy, and straining to void. Symptoms of bladder hyper-irritability include urinary urgency, requency, and nocturia. The etiology of acute retention is unclear. Prostatic infarction occurs in 85% of patients with acute retention as opposed to 3% of prostatectomy patients without acute retention. There is some latitude as to what constitutes the degree of chronic retention requiring surgery. Mebust(2) and Fain(3) recommend surgery for chronic retention of 60 ml or greater. Drach(4) has demonstrated that surgery on candidates with retention of greater than 150 ml has a poorer outcome. The etiology of gross hematuria is unknown, but it carries with it an increased incidence of problems for the patient. Altered urodynamic function is an indication for surgery when the peak urinary flow rate is less than 13 ml per second. Bladder stones are a relative indication. Table 1 INDICATIONS FOR SURGERY Bladder Outlet Obstruction Bladder Hyper-Irritability Acute Urinary Retention Chronic Urinary Retention Recurrent Gross Hematuria Recurrent Urinary Tract Infections Azotemia Altered Urodynamic Function Bladder Stones Complications of Surgery Mortality for TURP is .2%, most commonly from sepsis in debilitated patients. A secondary cause of death is cardiac complications. Morbidity is about 18% as reported by Mebust(5) (see Table 2). The incidence of complications is related to the size of the gland and the operative time. The results are better when the prostate is smaller than 45 gm and the surgical time is less than 90 minutes. The major complications of surgery are as follows: Interoperative blood loss requiring transfusion - 2.5%: 85% of these patients require two units or less. The average blood loss for a TURP is 250-400 ml. Transurethral Resection Syndrome - 2%: The symptoms include mental confusion, nausea, vomiting, hypotension, bradycardia, and visual disturbances. The etiology of Transurethral Resection Syndrome is not clear. In 1956, Harrison(6) suggested that it is the result of excessive fluid absorption during surgery resulting in dilutional hyponatremia. The average patient absorbs 1 liter of fluid during surgery. The treatment is diuretics. Extravasation - 2%: The symptoms of extravasation (perforation of the prostatic capsule), are restlessness, nausea, vomiting, and abdominal pain. The patient may experience these symptoms even while under regional anesthesia. The definitive treatment is to control bleeding and to terminate surgery as soon as possible. Postoperatively, 92% of patients with this complication are managed successfully with catheter drainage. Extensive extravasation may require suprapubic drainage. Epididymitis(7) - 2.3%: This complication occurs more frequently in patients with long term preoperative catheter drainage, urethritis, or preoperative recurrent epididymitis. There has been much dispute in the literature as to how to prevent this complication. In 1928, Dr. Edwin Alyea(8) proposed concurrent ligation of the vas deferens to prevent an ascending infection. Although there is evidence to suggest Alyea’s approach may be helpful, Fain(9) does not recommend routine vasectomy since the risk of postoperative epididymitis is low. He performs a prophylactic vasectomy only on patients who have an increased risk of infection. Mebust(10) also recommends against routine vasectomy. It has been suggested that antibiotic prophylaxis may help prevent postoperative infections, including epididymitis. Some studies indicate that they might help. Mebust,(11) however, did not find that antibiotics appreciably reduced the incidence of epididymitis. Table 2. CAUSES OF MORBIDITY Perioperative Blood loss 2.5% Extravasation 2% Transurethral Resection Syndrome 2% Postoperative Failure to void 6.5% Bleeding 3.9% Clot Retention 3.3% Epididymitis 2.3% RESULTS OF SURGERY(12) Long term results of surgery are as follows: After two months, 97% of patients were happy with the results; 2.7% experienced vesical neck contraction; 2.5% suffered from urethral stricture; 1.2% had mild stress incontinence; and .5% had significant stress incontinence. After one year,(13) 84% of patients reported improvement from their preoperative condition and 10% were unchanged. After three years, 75% of patients noticed improvement and 13% were unimproved. 50% of patients experienced retrograde ejaculation. _____________________________ 1 Winston K. Mebust, "Transurethral Surgery" in Walsh et al, Cambell’s Urology, Saunders, 1992, pp. 2900-2922. 2 Winston K. Mebust and William L. Valk, "Transurethral Prostatectomy", in Frank Hinman, Jr., Benign Prostatic Hypertrophy, Springer Verlag, 1983, pg. 844. 3 William R. Fain, "Transurethral Prostatic Electroresection", in James F. Glenn, Urological Surgery, Lippincott, 1991, pg. 569. 4 G. W. Drach, et al., "A Method of Adjustment of Male Peak Urinary Flow for Varying Age and Volume Voided", Journal of Urology, 1982, Vol. 128, pg. 960. 5 Winston K. Mebust, et al., "Transurethral Prostatectomy: Immediate and Postoperative Complications: A Cooperative Study of Thirteen Participating Institutions Evalutating 3,885 Patients", Journal of Urology, 1989, Vol. 141, pp. 243-247. 6 R. H. Harrison et al., "Dilutional Hyponatremic Shock: Another Concept of Transurethral Prostatic Resection Reaction", Journal of Urology, 1956, Vol. 75, pp. 95-110. 7Winston K. Mebust and William L. Valk, "Transurethral Prostatectomy", in Frank Hinman, Jr., Benign Prostatic Hypertrophy, Springer Verlag, 1983, pg. 844. 8 Edwin Alyea, "Vasoligation: A prevention of Epididymitis before and after Prostatectomy," Journal of Urology, vol.19, 1928, PP. 65-80. 9 William R. Fain, "Transurethral Prostatic Electroresection", in James F. Glenn, Urological Surgery, Lippincott, 1991, pg. 569. 10Winston K. Mebust and William L. Valk, "Transurethral Prostatectomy", in Frank Hinman, Jr., Benign Prostatic Hypertrophy, Springer Verlag, 1983, pg. 844. 11 Ibid. 12 Winston K. Mebust, et al., "Transurethral Prostatectomy: Immediate and Postoperative Complications: A Cooperative Study of Thirteen Participating Institutions Evalutating 3,885 Patients", Journal of Urology, 1989, Vol. 141, pp. 243-247. 13 R. C. Bruskevitz, et al., "Three Year Followup of Urinary Symptoms after Transurethral Resection of the Prostate", Journal of Urology, 1986, Vol. 136, pp. 613-615.
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Editor's Note