THE JOURNAL OF UROLOGY
Vol. 69, No. 2, February 1953
Printed in U.S.A.
DIVERTICULUM OF THE MALE URETHRA ERNEST N. KHOURY
From the Urological Service of the Jamaica Hospital, Jamaica, N. Y.
Diverticulum of the male urethra is rare. Undoubtedly many more instances have occurred than have been reported, but up to January 1951, Pate and Bunts were able to find only 197 cases in the extant literature. They added 28 cases of their own bringing the total to 225. All of their cases were of traumatic origin and followed peri-urethral abscess in paraplegic patients (i.e. trauma from infection). Since the Cumulative Quarterly Index Medicus has not been published in the past few years, and because of the interruption in the exchange of scientific data caused by world conditions, any review at this time must needs be incomplete. The author has, however, collected 8 cases since Pate and Bunts' excellent review, and these with the two cases to be reported in this paper, bring the grand total to 235 cases of diverticula of the male urethra. Diverticula of the female urethra are not uncommon. This is not surprising when one considers the tremendous trauma brought to bear on the inferior surface of the female urethra which is at best anatomically poorly supported. The male urethra, on the other hand, is anatomically very well protected against herniation. The dense and compact protection afforded the posterior urethra by the enveloping prostate are more than adequate. The membranous urethra is surrounded by the tough components of the pelvic fascia and the sphincter membranaceae urethrae with its investing fascia. The bulbous and pendulous urethra are both surrounded by several layers of dense fascia, and, in addition, are imbedded in the corpus spongiosum with its tough, fibrous, trabeculated vascular tissue. An accolade to the toughness of the fascial supports of the cavernous urethra is evident in the innumerable inept soundings performed daily with perforation and false passage formation. These false passages are a common observation in the routine cystoscopies of any large clinic, and yet from these violations of the fascial confines of the urethra, only rarely do diverticula develop which are of any clinical significance. ETIOLOGY
The rarity of the lesion precludes the acceptance of trauma and back pressure per se as the only reasons for this disease. Back pressure from simple urethral obstruction, due either to stricture or clamps or stones, does not give a satisfactory answer because this type of obstruction is very commonly seen with disastrous trabeculation of the bladder and hydro-ureter, and yet no diverticulum formation is noted in the urethra. The number of Cunningham incontinence clamps used in the last two decades ought to have increased enormously the number of urethral diverticula encountered, yet statistically, and by personal observation this is not true. In view of this, reasons must be postulated or established why in one patient a diverticula de291
ERNEST N. KHOURY
velops shortly after using a clamp, and yet another will use a clamp for a number of years without any observable ill effects on the urethra. That congenital diverticula without any existing obstruction distal to them do occur is a fact from observing case 1 in this paper and the reports of several others. Embryologically, Johnson demonstrated definite cystic epithelial lined structures just beneath the floor of the distal urethra, some of which communicated with the ureteral lumen to form small diverticular-like structures. The formation of the floor of the urethra by midline fusion is fraught with possibilities of an area of non or incomplete fusion which could be covered over by the mesenchyme and ectoderm and become clinically evident in later years when a distal urethral obstruction developed. Taking this a step further, one can easily visualize an area which has a deficiency of either endoderm or mesenchyme or both being covered by the ectoderm and remaining as an undetected weak point vulnerable to outpouching under stress. In effect, congenital diverticula and these weakened areas are nothing more than covered over hypospadias. Fagerstrom postulates the theory that injury to the nerves to the urethra as they course past the prostate on their way to the urethra deprives the urethral wall of its tone and leaves it vulnerable to the development of herniations. This seems to be borne out more clearly in the series that Pate and Bunts reported. They found a high incidence of diverticula following peri-urethral abscess in the paraplegic patients (26 to 54 patients with peri-urethral abscess developed diverticula). This certainly is not in keeping with the general observations of the follow-up of peri-urethral abscess, and can be explained only on the interference in the tonus of smooth muscle, and tissue in general in these paraplegic patients. That considerable nerve injury occurs in a radical perineal prostato-seminal vesiculectomy cannot be gainsaid. However, since large numbers of radical perineal procedures of this type are performed, and actually, large numbers of them do use clamps if not indefinitely, certainly in the early stages of temporary incontinence, and since diverticula are rarely seen under these circumstances, nerve injury alone cannot be the sole factor. In Pate and Bunts' group there was obvious trauma coupled with nerve injury; in others, it is most likely nerve injury coupled with embryological deficiency. A third factor to be considered is the use of estrogens (case 2). It has been my observation that there is a decided prolongation of incontinence in patients who have had total perineal prostato-seminal vesiculectomy and who have been given postoperative estrogen therapy for cancer of the prostate. This is probably caused by the relaxation of smooth muscle and fibrous tissue induced by this hormone. Case 2 shows this action very well, for after diverticulectomy, the patient was completely continent except for occasional drops occurring after heavy lifting or severe straining. He had not had stilbesterol at this time for several weeks. The drug was renewed because of apprehension that recurrence of cancer might occur, and within 48 hours, he became completely incontinent. Reduction in dosage ameliorated the condition and a trial withdrawal resulted in return of control. This return of sphincter tone has been observed several times on other patients and is too consistent to be regarded as coincidental.
DIVERTICULUM OF MALE URETHRA
Therefore, this tissue relaxing action could start a congenital ·weakness herniating and result in a full fledged diverticulum under conditions of minimal stress. Watts' original classification, which is very complete and which has served as a model for classifying diverticula of the male urethra, follows: A. Congenital diverticula R Acquired diverticula due to: 1. From dilatation of the urethra due to: a. urethral calculus b. urethral stricture 2 . Perforation of the urethra from: a. injuries to the urethra b. rupture of abscesses into the urethra c. rupture of into the urethra From the conclusions drawn from the other reported cases and those observed here, this list can be narrowed to two categories: A. Congenital diverticula 1. Those present without obstruction or influence of hormones or nerve injury. Most of these are noted as incidental findings or appear in life. 2. Those appearing clinically after the introduction of the agents mentioned in the previous sentence. B. Traumatic diverticula 1. Mechanical trauma 2. Chemical trauma (caustics, etc.) 3. Inflammatory trauma (peri-urethral abscess) Thus underlying any nontraumatic diverticulum of the urethra in the male is an embryological deficiency which is aggravated by either obstruction, hormones, nerve injury, or any combination of these. Only in this way can ,ve explain the rare appearance of diverticula under identical clinical and hydrodynamic conditions. The traumatic diverticula occur because of artificially induced weakness, the others occur from a basic embryological deficiency. PATHOLOGY
Pathologically the normal transitional epithelium of the urethra is usually the seat of squamous metaplasia of varying degrees. The diverticulum wall is generally dense fibrous tissue of the compressed spongiosum which becomes atrophic. SYMPTOMS
The congenital diverticula may be symptomless, as in case 1 of this paper. In infants, however, these diverticula may cause urinary obstruction with retention as reported by Gross et aL In adults, infection within the diverticulum results in foul urine, frequency of urination, and stone formation within the sac. The most constant sign is the development of a midline mass which is fluetuant and empties on manual pressure. This mass enlarges during micturition and may cause delayed dribbling. Final diagnosis is made by panendoscopy or cystourethrography.
ERNEST N. KHOURY CASE REPORTS
Case 1. E. D., a 27 year old white man, was seen because of bloody semen of 3 weeks' duration. Two months previously, torsion of the cord required orchiectomy. Examination revealed the absence of the left testicle, and a boggy and swollen prostate and seminal vesicles. The prostatoseminal secretion revealed microscopic pus and blood. A diagnosis of prostato-seminal vesiculitis was made and he was treated conservatively. When the inflammation subsided, panendoscopy disclosed an opening on the floor of the bulbous urethra. The opening measured 5 mm. in diameter and would not admit the sheath of the panendoscope. A cysto-urethrogram showed a diverticulum (fig. 1). The patient had never had a urethral infection or injury, and the urethra was patent to a 28F sound. The patient had been symptomless, and as a result, no definitive treatment for the diverticulum was administered.
Fm. 1. Case 1. Congenital asymptomatic diverticulum
This is an instance of a true congenital diverticulum in an adult without any history of any previous urethral obstruction. If, however, he should in the future develop strictures or require the use of a clamp, this diverticulum may well become clinically significant. Case 2. M. F., a 59 year old white man, was first seen November 30, 1948 because of urinary retention and a previous history of prostatism. Examination revealed a firm but not stony hard prostate. A diagnosis of benign prostatic hyperplasia was made and a transurethral prostatectomy done on December 2; 35 gm. tissue was removed without incident. The postoperative course was uneventful. Examination of the tissue revealed low grade adenocarcinoma. Acid phosphatase both pre- and postoperatively was normal. The patient was placed on 10 mg. stilbesterol daily, and on January 13, 1949 a total perineal prostato-seminal vesiculectomy was done. The postoperative course was uneventful save for a ten day period of perineal urinary fistula which closed spontaneously without a catheter. At first the patient was totally incontinent of urine except when lying down or at rest. He was given sphincter exercises (alternate starting and stopping the stream). He was also given 10 mg. of stilbesterol daily. In order to allow his
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bladder to fill more fully during the day so that he could practice his sphincter exercises, he used a Cunningham incontinence clamp. This he used only while at business during the day which involved only eight to ten hours; at home he had
Fm. 2. Case 2. Diverticulurn that developed after surgery
Fm. 3. A, schematic drawing of long section of penis. B, diverticulurn opened with lines of incision. C, repaired urethral showing suture line on right side.
no need for it. The incontinence diminished to stress incontinence of a minor degree. Three months after prostatectomy, the caliber of the urethra was 28F. Seven months after the total prostatectomy, a walnut sized mass was noted at the penoscrotal junction. It was not painful and collapsed on manual pressure causing urine to come out of the urethra. Panendoscopy showed no distinct opening, but
ERNEST N. KHOURY
there seemed to be a diffuse dilatation of the bulbous urethra. The use of the clamp was terminated, and the distal urethra dilated to 30F to afford free drainage. Stress incontinence continued and in spite of the removal of the obstructing clamp, the sac seemed to enlarge. A cysto-urethrogram on January 20, 1950 revealed a sacciform diverticulum of the bulbous urethra, and a smaller one distal to it on the pendulous urethra (fig. 2). On February 7 a diverticulectomy and urethral repair was done. The pathological change noted at operation was an epithelial lined bulging of the floor of the bulbous urethra for a distance of four centimeters with no change in the continuity of the roof of the urethra. A longitudinal schematic drawing is seen in figure 3, A. The larger diverticulum had compressed and atrophied the corpus spongiosum and was separated from the skin by a much attenuated Buck's fascia and Calles' fascia.
Fm. 4. Case 2. Postoperative cysto-urethrogram TECHNIQUE OF REPAIR
A midline incision was made over the penoscrotal junction and the fascia ot Calles incised. The diverticulum presented immediately into the wound covered by thin atrophic corpus spongiosum. This was incised and the larger diverticulum exposed. The diverticula was then opened and the redundant tissue on the ventral aspect resected so that more was removed from the right of the midline than from the left. Thus a flap was formed which when placed over the catheter from left to right formed a new floor of the urethra with an intact vascular supply on one side (fig. 3, B). The resultant fibromucosal suture line came to lie on the right side of the newly formed tube and near its dorsal wall (fig. 3, C). This was done to avoid a midline suture line which might be in continuity with the skin incision and thereby predispose to fistula formation. The deep fascia was then closed with interrupted double "0" chromic catgut sutures, with a drain of rubber tissue down to the urethra. The skin was closed ·with silk interrupted sutures. The drain was left in situ 48 hours.
DIVERTICULUM OF MALE URETHRA
The catheter was left in situ for 3 weeks at which time the patient began to void around it. Upon removal, a urinary fistula developed through the previous site of the rubber tissue drain. This closed spontaneously in 9 days. The postoperative cysto-urethrogram taken on May 12 is shown in figure 4. Immediately postoperatively (after the perinea! fistula had closed) the patient was continent except on severe straining; at this time he had not had stilbesterol for 2 months. However, because of apprehension over recurrence of cancer, this medication was started. Two days afrer the institution of estrogen therapy, he became completely incontinent again. The dosage was reduced and the incontinence became a stress incontinence of a moderate degree. After 6 months it was completely discontinued and the continence returned as before therapy had been started, thus demonstrating the effect on muscle tonus of estrogens. DISCUSSION
In the foregoing pages it has been postulated that the basic reason for any nontraumatic diverticulum of the male urethra is a congenital weakness of the urethral wall or a frank congenital diverticulum lying symptomless until distal obstruction of the urethra enlarged it making it clinically evident. This theory has support in the work of Johnson on human embryos, and in the observations of the 2 cases in this paper where a symptomless congenital diverticulum was observed in an adult. This theory of congenital predisposition or actual herniation is readily explainable embryologically and is in keeping with similar ideas on the congenital predisposition to the formation of cystocele and inguinal hernia on the basis of embryologically poorly formed supporting structures. The great mass of distal urethral obstructions (strictures and Cunningham incontinence clamps) occurring in everyday practice over prolonged periods of time would have certainly yielded many more instances of diverticula if back pressure alone were the sole factor in the formation of these abnormal structures. In addition the influence of nerve injury as a contributory factor, as postulated by Fagerstrom, is considered and given its place as an etiological factor in the causation of diverticula. This increased susceptibility to diverticulum formation is amply demonstrated by the much higher incidence of diverticula noted in the series of Pate and Bunts collected in paraplegic patients who had peri-urethral abscess. Furthermore, the relaxing effect of estrogenic substances on the smooth muscle and connective tissue is presented as a third factor which might contribute to the development of a diverticulum if congenital weakness were present. It is believed that in case 2, this, in addition to the previous two factors, led to the formation of the diverticula in question. I believe, therefore, that whenever a Cunningham incontinence clamp is to be used, a cysto-urethrogram should be done to rule out any congenital diverticula which might be present and asymptomatic. This holds true especially if estrogens are to be used
ERNEST N. KHOURY
The literature has been reviewed and 2 cases of diverticulum of the male urethra added to it. This totals 235 cases reported in the extant literature. The various theories of formation of non-traumatic diverticula are discussed. The concept is advanced that all nontraumatic diverticula are due to embryologically incomplete or nonunion of the inferior surface of the urethra during fetal life. The relaxing effect of estrogens on smooth muscle and connective tissue and its relaxation to development of diverticula is discussed. The author wishes to gratRfully acknowledge Dr. William A. Griesau's splendid drawings of the surgical procedure. 148-25 89th Ave., Jamaica, N. Y. REFERENCES FAGERSTROM, D. P.: Etiology of acquired diverticula of acquired diverticula of anterior urethra and its relation to cause of postprostatectomy incontinence. J. Urol., 49: 357, 1943. GRoss, R. AND BILL, A.H., JR.: Concealed diverticulum of male urethra as cause of urinary obstruction. Pediatrics, 1: 44, 1948. JoHKSON, F. P.: Later development of the urethra in the human male. J. Urol., 4: 447, 1920. PATE, V. AND BuNTs, C.R.: Urethral diverticula in paraplegics. J. Urol., 65: 108, 1951. WA'l'TS, S. H.: Urethral diverticulum in the male, with report of a case. Johns Hopkins Hosp. Rep., 13: 49, 1906.