PSEUDODIVERTICULUM AFTER ERNEST
RETROPUBIC J. ENGLAND,
OF PROSTATIC
URETHRA
PROSTATECTOMY
F.R.A.C.S
ANTONY I. LOW, F.R.A.C.S. From the Department of Urology, Royal Perth Hospital, Perth, Western Australia
ABSTRACT - A case of pseudodiverticulum of the prostatic urethra following retropubic prostatectomy is described, and likely factors in its pathogenesis discussed.
Diverticula of the posterior urethra are rare and are usually acquired following obstruction or destruction of the urethral wall through trauma or infection, or both. ’ Diverticula arising from the prostatic urethra are even less common, and most reported cases have been associated with congenital abnormalities or with prostatic abscess and/or calculus.’ The following is a report of a large anteriorly placed pseudodiverticulum of the prostatic urethra following retropubic (Millin) prostatectomy. We have been unable to find any similar reports in the literature. Case Report A sixty-five-year-old male was first seen in our department on June 12, 1973. A retropubic prostatectomy had been performed eleven months earlier at which 20 Gm. of tissue had been removed, and histologic examination had shown benign hyperplasia and prostatitis. His early convalescence had been stormy with several episodes of “clot retention,” marked leakage of urine and wound infection, but these had gradually resolved by the time of his discharge from hospital six weeks later. The patient remained well for several months, but over the six months prior to this admission increasing frequency, enuresis, and deterioration of his urinary stream, as well as nausea, anorexia, and lethargy developed, with a weight loss of about 20 Kg. On physical examination, he was obviously dehydrated, and had a “bladder” palpable up to the umbilicus. Laboratory investi-
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gations showed anemia (hemoglobin 8.5 Gm. per 100 ml.), a high white cell count (17,600 per cubic millimeter), a very high sedimentation rate (144 mm. drop in one hour), moderate uremia (serum creatinine 3.4 mg. per 100 ml., serum bicarbonate 16 mEq. per liter) and a urinary tract infection with Escherichia coli. Excretory urogram showed bilateral hydronephrosis and hydroureter of more marked degree than eleven months earlier. Micturating cystogram and retrograde urethrogram demonstrated persistence of the previously noted small multiple bladder diverticula, grade II reflux up the left ureter, and a large “sack’ arising from the prostatic cavity and extending anterosuperiorly between the bladder and the abdominal wall (Fig. 1A and B). After transfusion and treatment with ampicillin, surgery was performed on July 29, 1973. Preliminary panendoscopy confirmed the presence of an opening in the anterior aspect of the prostatic cavity, and via a transverse incision, a large urine-filled space was located immediately deep to the rectus muscle, communicating with the prostatic cavity and lined by granulation tissue. The bladder was opened vertically and the incision continued inferiorly to enter the defect in the prostatic cavity. After obliteration of the pseudodiverticulum and removal of its lining granulation tissue, the vesicoprostatic defect was reconstituted with a single layer of chromic catgut, The catheter was removed after ten days, and the patient was then able to void with a good stream, his residual urine being 80 ml. Since his
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FIGURE 1. (A) Cystogram (anteroposterior view) showing large smooth cavity lying anterior to grossly trabeculated bladder with its multiple diverticula, and reflux into lower left ureter. (B) Cystourethrogram (lateral view) showing large pseudodiverticulum ertending anterosuperiorly from prostatic urethra. (C) Retrograde urethrogram showing ragged prostatic urethra with no evidence of residual diverticulum.
again risen to 3.5 mg. per 100 ml., sedimentation rate was 125 mm. drop in one hour, and the Serratia marcescens urinary infection was still present. The retropubic abscess was incised anddrained, and a urethral catheter was inserted; it was noted that the abscess cavity communicated with the prostatic urethra. Postoperatively, his bladder was washed out with streptomycin (500 mg. per liter of normal saline at pH 8.5), every six hours for one week, along with a six-week course of oral sulfamethoxazole/trimethoprim compound. Subsequent urine samples were not infected, and since panendoscopy had shown no evidence of residual defect in the prostatic cavity or of outflow obstruction, his urethral catheter was removed after three weeks. He then voided well, and repeat radiologic studies demonstrated improvement in the degree of back pressure on his kidneys and ureters, persistence of the left
erythrocyte sedimentation rate remained high, and his urine was infected with Serratia marcestens, he was given a one-week course of gentamicin. He was seen again five weeks later with a threeday history of a painful, inflamed, fluctuant suprapubic swelling, marked burning on micturition, and oliguria. His serum creatinine had
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vesicoureteric reflux, and no evidence of urethral diverticulum (Fig. 1C). Over the ensuing three months, increasing difficulty in micturition again developed with a large residual urine; Serratia marcescens infection relapsed, and his white cell count and erythrocyte sedimentation rate remained elevated at 17,600 per cubic millimeters and 110 mm. drop in one hour, respectively. Marked bladder neck contracture was found at panendoscopy, and this was treated by transurethral diathermy incision of the bladder neck. He was again given oral sulfamethoxazole/trimethoprim compound to which the organism had remained sensitive. While on this drug, he remained well; but on ceasing it, his symptoms returned, and bladderneckcontracture was again demonstrated. A further transurethral incision was performed, and the bladder neck and prostatic region were injected with triamcinolone to try to prevent further fibrosis. He is presently on long-term low-dose, prophylactic sulfamethoxazoleltrimethoprim (one tablet per day) which has prevented further urinary infection, and contracture of the bladder neck has not recurred following a second injection of triamcinolone. Comment In view of the widespread use of retropubic (Millin) prostatectomy, and the absence of any previous reports of prostatic diverticula following this procedure, it must be concluded that this complication is exceedingly uncommon. A somewhat similar pseudodiverticulum with extension into the thigh was reported by 0mo-Dare,3 but this followed traumatic rupture of the urethra, the point of communication being at the prostatomembranous urethral junction rather than in the prostatic urethra proper. Shaikh and Malament described 3 cases of pseudodiverticulum of the bladder all of which followed extensive bladder resection and were associated with bladder outlet obstruction. In all their cases, the diverticula were located between the subcutaneous fascia and the rectus sheath (whereas our patient’s cavity was deep to the rectus muscle), and they considered them to be the result of postoperative
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encapsulation of urine communicating with the bladder and therefore false, rather than true, diverticula. Although the exact pathogenesis is unknown, the following factors were probably important in the formation and persistence of the pseudodiverticulum. The “clot retention” caused a large pressure build up in the bladder, and this was transmitted directly to the prostatic cavity via the now incompetent bladder neck.5 Fluid then leaked out into the retropubic space via the incision in the prostatic capsule, as this presumably offered less resistance to flow than the clot-filled urethra. The retropubic drain was probably removed before the extravesical cavity had been obliterated, allowing to and fro passage of infected urine to occur between the prostate and the pseudodiverticulum. This cavity thereby gradually increased in size and became lined with granulation tissue resulting in a large, chronically infected, urine-filled space whose eradication could now only be achieved by surgery. Persistent infection resulted in the suprapubic abscess which was subsequently drained, and probably also contributed to the recurrent bladder neck contracture. The patient is presently well on prophylactic sulfamethoxazole/trimethoprim. It is hoped that this, along with the triamcinolone injections into his bladder neck,6 will prevent further problems. Perth, Western Australia 6000 (DR. LOW) References 1. CAMPBELL, M. F., and HARRISON, J. H.: Urology, 3rd ed., Philadelphia, W. B. Saunders Co., 1970, p. 550. 2. CURRARINO, G. : Diverticulum of prostatic urethra developing post-operatively from stump of congenital rectourethral fistula, Am. J. Roentgenol. 106: 211(1969). OMO-DAR&,P.: Posterior urethral diverticulum in the male, Br. J. Ural. 40: 445 (1968). SHAIKH, B. N., and MALAMENT, M.: Pseudodiverticulum of the urinary bladder, Radiology 96: 417 (1970). WHITAKER, R. H. : The fate of the prostatic cavity after retropubic prostatectomy, Br. J. Urol. 43: 722 (1971). DAMICO, C. F., MEBUST, W. K., VALK, W. L., and FORET, J. D.: Triamcinolone: adjuvant therapy for vesical neck contractures, J. Urol. 110: 203 (1973).
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