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External Sphincterotomy in Paraplegics: Technique and Results
Vol. 103, Jan. Printed in U.S.A.
TI-IE JOURNAL OF UROLOGY
Copyright© 1970 by The Williams & Wilkins Co.
EXTERNAL SPHINCTEROTO:.vI:Y IN PARAPLEGICS: TECHNIQUE AND RESULTS R. J. CURRIE, A. A. BILBISI, J. C. SOHIEBLER
AND
R. 0. BUNTS
From the Urological Section, Surgical Service, McGuire Veterans Aclrninistration Hospital, Richmond, Virginia
The act of voiding is an integrated dynamic process whereby the balance of expulsive forces exceeds those of resistance and micturition ensues. In patients v,ith a neurogenic bladder secondary to spinal cord injury the greatest area of resistance is in the membranous urethra. External sphincterotomy reduces urethral resistance to such a level that voiding can occur by reflex vesical contraction or by using the Crede maneuver. After injury to the spinal cord the bladder usually regains considerable power of contraction and the type of micturition is dependent on the level of the lesion. In patients with an upper motor neuron lesion, because of spastic pelvic musculature, the external sphincter fails to relax synchronously with the detrusor contraction, thus resulting in an inability to void or incomplete voiding with a high residual urine. J\fost paraplegics with a lower motor neuron lesion have reduced resistance forces but there is a proportionately greater reduction in the ability of the bladder to contract. Therefore, effective voiding can occur only by using the Crede maneuver or by increased intra-abdominal pressure. In both instances decrease in the outflow resistance secondary to the effects of an external sphincterotomy renders the bladder more efficient in the expulsion of urine and in the reduction of residual urine.
trial to determine the amount of residual urine. Each patient underwent a voiding cystourethrogram (either spot or cine films) and a cystometrogram to determine the maximum contractile pressure in the bladder and the retrograde urethral pressure was determined. The retrograde urethral pressure was obtained by suspending a warm saline solution 90 cm. above the patient's symphysis pubis and connecting this solution to a Lewis cystometer. The cystometer was connected to a No. 18 Foley catheter which was inserted into the fossa navicularis. This area of the penile urethra was used because of the ease of placement and measurable pressure differences could not be detected on the Lewis cystometer between the pressures obtained at the fossa navicularis and those just distal to the external sphincter muscle. After inflating the Foley balloon with 2 cc fluid the saline was allowed to enter the urethra by gravity and the end point was determined with the pressure leveled off while the saline was still dripping. Sphincterotomy was performed with a resectoscope and a knife electrode, incising the external sphincter at 3 and 9 o'clock positions. The incision was extended from the distal verumontanum for 2 cm. through the external sphincter to a depth of 6 mm. All arterial bleeders were electrocoagulated. A No. 24, 3-way catheter was inserted postoperatively and was removed in 4 to 7 days. After the catheter was removed repeat voiding cystourethrogram, residual urine values and retrograde urethral pressures were obtained.
TECHNIQUE
There were 85 patients with spinal cord injmy resulting in an upper or lower neuron bladder who were subjected to incision of the external sphincter. Indications for sphincterotomy were a neurogenic bladder with residual urine greater than 90 cc, inability to void or early vesicoureteral reflux. All patients were determined by cystometry to be out of spinal shock. Prior to sphincterotomy all patients were given a voiding
RESULTS
Postoperatively all 85 patients were voiding freely without catheter drainage. In more than 50 per cent of the patients a residual urine of less than 20 cc was obtained. In patients with reflex neurogenic bladders there was an average decrease in the retrograde urethral pressure of 19 mm. Hg. The maximum drop in pressure was 38 mm. Hg and the minimum drop was 8 mm. Hg. Post-sphincterotomy most pressures in pa-
Accepted for publication January 2, 1969. Read at annual meeting of Mid-Atlantic Section, American Urological Association, ·Williamsburg, Virginia, October 23-26, 1968.
64
EXTERNAL SPHINCTEROTOIVIY IN PARAPLEGICS
65
F'rn. L A, preoperative cystourethrogram demonstrates right ureterovesical reflux and ex:· ternal sphincter. B, postoperative cystomethrogrnm reveals loss of right ureterovesical and absence of constricted area of external sphincter. Incomplete left ureterovesical reflux is prese:1L cystourethrogra.m 6 months later is compatible with cystitis but no reflux is present and area, at sphincter is widely patent.
Fm. 2. A, cystourethrogram in C-7 paraplegic with no previous operation. Note open bladder neck and narrowed dye stream in area of external sphincter. B, external sphincter has been well incised) as was portion of bulbous urethra. Urine residual value dropped from 100 to 5 cc postoperatively tients with cervical and upper thoracic lesions were in the range of 40 mm. Hg. In 10 patients with lower motor neuron lesions the average pressure post-sphincterotomy was 29 mm. Hg. Regardless of the level of spinal cord damage all postoperative retrograde urethral pressures ,vere decreased as compared to the preoperative value. The greater the difference between the maximum pressure obtained with the cystometrogram and the postoperative sphincter pressures, the less was the residual. Ten patients with reflux were subjected to external sphincterotomy. In 7 reflux
subsided completely and in 1 patient it was greatly reduced (fig. 1). In the remaining 2 patients reflux had been present for at lea,st 2 years. Of the 85 patients who had external sphincterotomy, 20 patients had had prior transmethral resections of the bladder neck. This operation demonstrated no reduction in the preoperative retrograde urethral pressures even though 1, 2 and, in some cases, 3 resections had been per·· formed. Postoperatively, there was no greater significant drop in the sphincter pressures ,vhen compared to thooe who had not undergone resection of the bladder neck.
66
CURRIE AND ASSOCIATES
B
FIG 3 A note that with retrograde urethral pressure of 64 mm. Hg and maxim_um cystometrographic pressl;re.of 46 mm. Hg patient voids but has residual urine of 1~5 cc. B, J?OStoperat1ve retr_ograde t~rethral pressure demonstrates 34 mm. Hg pressure drop and now patient retams only 20 cc residual urme.
In most patients who had not had a resection of the bladder neck the cystourethrogram demonstrated an area of constriction at the external sphincter while the bladder neck was widely patent. Post-sphincterotomy the bladder neck picture remained unchanged while the constricted area was absent (fig. 2). Postoperative complications have been rare. Two patients have been re-admitted with episodes of bleeding. The hemorrhage occurred between 12 and 14 days postoperatively and was treated successfully with re-insertion of a large Foley catheter. Several patients required an indwelling catheter for 2 to 3 weeks postoperatively. It was thought that in these cases urethral edema caused a temporary elevation of the urethral resistance. Prior to this study external sphincterotomy had been performed in 2 patients with the incision being made at 6 o'clock position. Bleeding was profuse in both patients. We feel that under no circumstances should the external sphincter be incised at the 6 o'clock position. However, we have incised at the 3, 9 and 12 o'clock positions at one operation without complications. There appears to be no greater decrease in the postoperative retrograde urethral pressures using the 3 areas as compared to the pressures followino-b incision at only the 3 and 9 o'clock positions.. There has been no dribbling incontinence, ep1didymitis or death.
DISCUSSION
In essence the Foley catheter is an artificial means of reducing urethral resistance. Reduction of outflow urethral resistance surgically and without catheter drainage has been attempted using various approaches. These methods include transurethral resection of the bladder neck, pudendal neurectomy, Y-V plasty of the bladder neck subarachnoid alcohol injections, selective sacr;l rhizotomy, membranous urethrolysis and external sphincterotomy. In 1948 Emmett suggested that obstruction in paraplegics who failed to void following resection of the bladder neck might be secondary to a hypertonic external sphincter and that bilateral pudenda! nerve sections, sacral rhizotomy or alcohol injection would probably relieve this spasticity. 1 In the same year Baumrucker stated that a spastic external sphincter was the cause of persistent suprapubic fistula and cauterized the external sphincter in 3 paraplegics. 2 Since 1956 Ross and associates have described their success with external sphincterotomy in 65 patients. 3- 6 1 Emmett, J. L., Daut, R. V. and_Dunn, _J. H.: Role of the external urethral sphmcter 111 the normal bladder and cord bladder. J. Urol., 59: 439, 1948. h 2 Baumrucker, G. 0.: ·Management of t e paralyzed bladder. Arch. Surg., 66: 484, 194~. , Ross, J. C., Gibbon, N. 0. K. and Dam'.'nski, M.: Division of the external urethral sphmcter
EX'l'ERNAL SPHINC'l'ERO'l'OlVIY IN PARAPLEGICS
Formerly their technique was to use a cold punch procedure hut bleeding was such a problem that this approach was rapidly abandoned. Subsequently, by using the Collings knife and electrocautery, Ross and associates incised the posterolateral aspect of the urethra from the distal verumontanum through the external sphineter to a depth of 6 mm. Sixty of 65 patients were ren·· dered catheter-free. Of paramount importance is the fact that 32 of 40 patients were followed for several years and have remained on an external appliance. Smythe performed external sphincterotomy on 8 paraplegics and rendered 7 patients catheterfree.7 Furthermore, his urethral pressure studies demonstrate that the entire prostatic urethra may represent the functional zone of the external sphincter. To objectively demonstrate the effectiYeness of incising the external sphincter, pressures exerted by this muscle had to be measured. Simons inserted a balloon-tipped catheter into the membranous urethra and with distention of the balloon recorded on a microcystometer an average of 23 mm. Hg as the pressure exerted by external sphincter in the normal male subject. 8 Emanuel, using a somewhat similar technique, obtained a pressure of 28 mm. Hg as a normal pressure of the external sphincter. 9 Fichardt obtained a Yalue of 40 to 60 mm. Hg for that pressure exerted by the external sphincter in Bantu'H. 10 He noted that each patient had his own critical pressure that was cmrntant. in the treatment of the paraplegic bladder. Brit.
J. Urol., 30: 204, 1958.
4 Ross, J.C., Gibbon, N. 0. K. and Damanski, M.: Further experiences with division of the external urethral sphincter in the paraplegic. J, Urol., 89: 692, 1963. 6 Ross, J. C., Damanski, lvI. and Gibbon, N.: Resection of the external sphincter in the paraplegic-preliminary report. J. Urol., 79: 742, 1958, 6 _Ross, J.C., Gibbon, N. 0. and Damanski, JU.: Division of the external sphincter in the treatment of the neurogenic bladder. Brit. ,J. Surg., 54: 627,
1967. 7 Smythe, C. A.: External sphiucterotomy in the management of the neurogenic bladder: a preliminary report. J. Urol., 96: 310, 1966. 8 Simons, I.: Advances in the field of cystometry due to clinical studies with the sphincterometer. IV. Studies in bladder function (a preliminary report). J. Urol., 36: 88, 1936. 9 Emanuel, M .. A new dynamic catheter-type sphinct.erometer. J. Urol., 90: 237, 1963. • 1 ° Fichardt, T.: Scree11ing urethrocystography of adnlt Bantu males under manometric control; normal and pathological findings. Bril. J. Radio!.,
32: 120, 1959.
67
:\Ieasurements of the entire urethral resistance were obtained by Draper.11 He inserted a catheter into the urethra which had been connected to a Y-tube. One limb of the Y-tube was attached to a measuring device, the other to a source of saline. The fluid was elevated and the pressure recorded when there was a sudden increase in the rate of flow of the saline. The average retrograde urethral pressures in normal patients using this method were 48 to 73 mm. Hg. Draper noted excellent correlation !Jet,veen the anterograde and retrograde urethral pres,;ures. Lapides' method of determining the normal pressures exerted by the external sphincter is to fill the bladder with 250 cc saline, insert a catheter just distally to the area in which a pre~sure value is to be obtained and record the pressure when the saline ceases to flow in a retrograde fashion through the urethra. 12 With his method the normal external sphincter pressure in male subjects was 42 mm. Hg. Furthermore, he noted that the highest resistances to flow were in the 2 cm. area near the striated muscle in both female and male patients with or without anesthesia. Chute, using air in a similar manner to Draper, obtained a value of 85 to 124 mm. Hg as the normal JJressure of the external sphincter. 13 It is apparent that the discrepancies in the values for the external urethral pressures are most likely due to the various methods of measurement. Retrograde urethral pressures have not been recorded in a large series of cord injury patients. Our method not only measures the pressure exerted by the external sphincter but also those pressures exerted by the elastic tissue and the smooth muscle of the prostatic and penile urethra, the bladder neck, the viscosity of the saline and the turbulence of flow through the urethra. In paraplegics with spinal cord damage resulting in an upper motor neuron lesion the average preoperative retrograde urethral pressure -was .54.8 mm. Hg. However, often with pelvic spasm the pressure rose to more than 100 mm. Hg. In u Davis, J.E., Morillo, J\L and Draper, J. vV. J\Ieasurements of urethral resistance. J. Urol., 85: 586, 1961. 12 Lapides, J., Ajemian, E. P., Stewart, B. II., Breakey, B. A. and Lichtwardt, J. R.: Fnrther observations on the kinetics of the nrethrovesical sphincter. J. Urol., 84: 86, 1960 . 13 Kleeman, F. J. and Clrnte, R. A.: A plan for the evaluation of patients with bladder dvsfuuction and the use of pudenda] neurectomv in selected cases . .J. Ural., 97: 1029, 1967 ·
68
CURRIE AND ASSOCIATES
those patients with lower motor neuron lesions the average preoperative retrograde urethral pressure 1rns 40 mm. Hg. This demonstrates that sphincter pressures in paraplegics with lower motor neuron lesions are lower than those with a reflex bladder. Yet the pressures arc of such a degree as to cause obstruction due to concomitant lmY bladder pressures. In patients who had 1, 2 and enn 3 resections of the bladder neck the preoperative and postoperative sphincterotomy retrograde urethral pressures were not dissimilar to those who hacl not had a prior operation on the bladder neck. ·when the preoperative pressure graphs showed the retrograde methral pressure was greater than the maximum -vesicul pressure the patient could not Yoid spontaneously (fig. 3). vVhcn the pressures were similar the patient voided. However, the patient had significant residual, i.e. more than 90 cc. The majority of preoperative cystourethrograms demonstrated a widely patent bladder neck regardless of the level of the lesion. This correlates well with Ascoli's findings vthich noted that in 69 per cent of paraplegics, cystourethrograms clemonstratecl a widely dilated bladder neck. 14 Furthermore, the same cystourethrograms demonstrated obstruction at the external sphincter in 48 of 55 cases. A narrowing of the dye stream was noted in the area of the external sphincter in almost all patients admitted to this study. This finding was more pronounced iu patients with an upper motor neuron lesion. Postsphincterotomy the contracture was absent. Thus, with no apparent obstruction one is hardpressed to condone excision of the bladder neck to relieve obstruction which was not present. The etiology of reflux in paraplegics is not in the scope of this paper. However, most investigators believe that reflux results from a combination of infection and increased intravesical pressure. The Foley catheter, although beneficial in reducing bladder pressure by reducing urethral resistance, acts as a focus of infection in the bladder and urethra. External sphincterotomy like,Yise decreases outlet obstruction while at the same time a nidus of persistent infection is eliminated. In this series 7 of 10 patients had complete disappearance of reflux. An additional patient had a marked decrease in reflux postoperatively. In 2 patients reflux had been present 14 As coli, R.R.: Radiological study of the vesical neck in paraplegia secondary to spinal cord injury. Paraplegia, 4: 235, 1967.
for more than 2 years. It is postulated that in these cases irreversible changes had occurred. Postoperatively, "'e have had the opportunity to perform cystoendoscopy on several patients in our study. The incision in the external sphincter is well epithelizecl, it has the appearance of a scarred open tube and there appears to be no obstruction to the free flow of the irrigating fluid through the urethra. Immediate results in our first 85 patients are encouraging. However, to be effective a new technique must stand the test of time. We have evaluated 30 patients who are at least 4 months post-sphincterotomy and 23 patients are catheter-free. Of the 7 patients still on catheter drainage, 2 prefer the catheter because of ease of care, 2 had persistent ureterovesical reflux and chose catheter drainage rather than the Crede maneuver. Therefore only 2 patients may be considered failures. These patients are on catheter drainage because of high residual urine. In both cases the postoperative retrograde urethral pressures were decreased when compared to the preoperative level yet there was little difference between the 2 values. vVe postulate that the sphincter was incompletely incised and that a repeat sphincterotomy would be beneficial. COKCLUSION
Indications for external sphincterotomy m patients with an upper or lo"·er motor neuron bladder are the requirement of urethral catheter drainage due to an inability to void, a high residual urine and/ or early vesicoureteral reflux. The procedure is successful because it lowers the pressure created by the external sphincter to a value below the maximum vesical pressure. Furthermore, external sphincterotomy reduces the effects of asynchronous contractions of the spastic pelvic musculature. Eight-five patients with spinal cord injury and resultant neurogenic bladders were rendered catheter-free immediately following incision of the external sphincter. Cystourethrograms demonstrated obstruction to the flow of contrast material to be in the area of the external sphincter and not at the bladder neck. This pictorial area of obstruction was not present in the postoperative cystourethrograms. Reflux was reduced or eliminated in 8 of 10 patients. The operative technique is easily performed, the complications are few and the results are immediate and impressive.
TI-IE JOURNAL OF UROLOGY
Copyright© 1970 by The Williams & Wilkins Co.
EXTERNAL SPHINCTEROTO:.vI:Y IN PARAPLEGICS: TECHNIQUE AND RESULTS R. J. CURRIE, A. A. BILBISI, J. C. SOHIEBLER
AND
R. 0. BUNTS
From the Urological Section, Surgical Service, McGuire Veterans Aclrninistration Hospital, Richmond, Virginia
The act of voiding is an integrated dynamic process whereby the balance of expulsive forces exceeds those of resistance and micturition ensues. In patients v,ith a neurogenic bladder secondary to spinal cord injury the greatest area of resistance is in the membranous urethra. External sphincterotomy reduces urethral resistance to such a level that voiding can occur by reflex vesical contraction or by using the Crede maneuver. After injury to the spinal cord the bladder usually regains considerable power of contraction and the type of micturition is dependent on the level of the lesion. In patients with an upper motor neuron lesion, because of spastic pelvic musculature, the external sphincter fails to relax synchronously with the detrusor contraction, thus resulting in an inability to void or incomplete voiding with a high residual urine. J\fost paraplegics with a lower motor neuron lesion have reduced resistance forces but there is a proportionately greater reduction in the ability of the bladder to contract. Therefore, effective voiding can occur only by using the Crede maneuver or by increased intra-abdominal pressure. In both instances decrease in the outflow resistance secondary to the effects of an external sphincterotomy renders the bladder more efficient in the expulsion of urine and in the reduction of residual urine.
trial to determine the amount of residual urine. Each patient underwent a voiding cystourethrogram (either spot or cine films) and a cystometrogram to determine the maximum contractile pressure in the bladder and the retrograde urethral pressure was determined. The retrograde urethral pressure was obtained by suspending a warm saline solution 90 cm. above the patient's symphysis pubis and connecting this solution to a Lewis cystometer. The cystometer was connected to a No. 18 Foley catheter which was inserted into the fossa navicularis. This area of the penile urethra was used because of the ease of placement and measurable pressure differences could not be detected on the Lewis cystometer between the pressures obtained at the fossa navicularis and those just distal to the external sphincter muscle. After inflating the Foley balloon with 2 cc fluid the saline was allowed to enter the urethra by gravity and the end point was determined with the pressure leveled off while the saline was still dripping. Sphincterotomy was performed with a resectoscope and a knife electrode, incising the external sphincter at 3 and 9 o'clock positions. The incision was extended from the distal verumontanum for 2 cm. through the external sphincter to a depth of 6 mm. All arterial bleeders were electrocoagulated. A No. 24, 3-way catheter was inserted postoperatively and was removed in 4 to 7 days. After the catheter was removed repeat voiding cystourethrogram, residual urine values and retrograde urethral pressures were obtained.
TECHNIQUE
There were 85 patients with spinal cord injmy resulting in an upper or lower neuron bladder who were subjected to incision of the external sphincter. Indications for sphincterotomy were a neurogenic bladder with residual urine greater than 90 cc, inability to void or early vesicoureteral reflux. All patients were determined by cystometry to be out of spinal shock. Prior to sphincterotomy all patients were given a voiding
RESULTS
Postoperatively all 85 patients were voiding freely without catheter drainage. In more than 50 per cent of the patients a residual urine of less than 20 cc was obtained. In patients with reflex neurogenic bladders there was an average decrease in the retrograde urethral pressure of 19 mm. Hg. The maximum drop in pressure was 38 mm. Hg and the minimum drop was 8 mm. Hg. Post-sphincterotomy most pressures in pa-
Accepted for publication January 2, 1969. Read at annual meeting of Mid-Atlantic Section, American Urological Association, ·Williamsburg, Virginia, October 23-26, 1968.
64
EXTERNAL SPHINCTEROTOIVIY IN PARAPLEGICS
65
F'rn. L A, preoperative cystourethrogram demonstrates right ureterovesical reflux and ex:· ternal sphincter. B, postoperative cystomethrogrnm reveals loss of right ureterovesical and absence of constricted area of external sphincter. Incomplete left ureterovesical reflux is prese:1L cystourethrogra.m 6 months later is compatible with cystitis but no reflux is present and area, at sphincter is widely patent.
Fm. 2. A, cystourethrogram in C-7 paraplegic with no previous operation. Note open bladder neck and narrowed dye stream in area of external sphincter. B, external sphincter has been well incised) as was portion of bulbous urethra. Urine residual value dropped from 100 to 5 cc postoperatively tients with cervical and upper thoracic lesions were in the range of 40 mm. Hg. In 10 patients with lower motor neuron lesions the average pressure post-sphincterotomy was 29 mm. Hg. Regardless of the level of spinal cord damage all postoperative retrograde urethral pressures ,vere decreased as compared to the preoperative value. The greater the difference between the maximum pressure obtained with the cystometrogram and the postoperative sphincter pressures, the less was the residual. Ten patients with reflux were subjected to external sphincterotomy. In 7 reflux
subsided completely and in 1 patient it was greatly reduced (fig. 1). In the remaining 2 patients reflux had been present for at lea,st 2 years. Of the 85 patients who had external sphincterotomy, 20 patients had had prior transmethral resections of the bladder neck. This operation demonstrated no reduction in the preoperative retrograde urethral pressures even though 1, 2 and, in some cases, 3 resections had been per·· formed. Postoperatively, there was no greater significant drop in the sphincter pressures ,vhen compared to thooe who had not undergone resection of the bladder neck.
66
CURRIE AND ASSOCIATES
B
FIG 3 A note that with retrograde urethral pressure of 64 mm. Hg and maxim_um cystometrographic pressl;re.of 46 mm. Hg patient voids but has residual urine of 1~5 cc. B, J?OStoperat1ve retr_ograde t~rethral pressure demonstrates 34 mm. Hg pressure drop and now patient retams only 20 cc residual urme.
In most patients who had not had a resection of the bladder neck the cystourethrogram demonstrated an area of constriction at the external sphincter while the bladder neck was widely patent. Post-sphincterotomy the bladder neck picture remained unchanged while the constricted area was absent (fig. 2). Postoperative complications have been rare. Two patients have been re-admitted with episodes of bleeding. The hemorrhage occurred between 12 and 14 days postoperatively and was treated successfully with re-insertion of a large Foley catheter. Several patients required an indwelling catheter for 2 to 3 weeks postoperatively. It was thought that in these cases urethral edema caused a temporary elevation of the urethral resistance. Prior to this study external sphincterotomy had been performed in 2 patients with the incision being made at 6 o'clock position. Bleeding was profuse in both patients. We feel that under no circumstances should the external sphincter be incised at the 6 o'clock position. However, we have incised at the 3, 9 and 12 o'clock positions at one operation without complications. There appears to be no greater decrease in the postoperative retrograde urethral pressures using the 3 areas as compared to the pressures followino-b incision at only the 3 and 9 o'clock positions.. There has been no dribbling incontinence, ep1didymitis or death.
DISCUSSION
In essence the Foley catheter is an artificial means of reducing urethral resistance. Reduction of outflow urethral resistance surgically and without catheter drainage has been attempted using various approaches. These methods include transurethral resection of the bladder neck, pudendal neurectomy, Y-V plasty of the bladder neck subarachnoid alcohol injections, selective sacr;l rhizotomy, membranous urethrolysis and external sphincterotomy. In 1948 Emmett suggested that obstruction in paraplegics who failed to void following resection of the bladder neck might be secondary to a hypertonic external sphincter and that bilateral pudenda! nerve sections, sacral rhizotomy or alcohol injection would probably relieve this spasticity. 1 In the same year Baumrucker stated that a spastic external sphincter was the cause of persistent suprapubic fistula and cauterized the external sphincter in 3 paraplegics. 2 Since 1956 Ross and associates have described their success with external sphincterotomy in 65 patients. 3- 6 1 Emmett, J. L., Daut, R. V. and_Dunn, _J. H.: Role of the external urethral sphmcter 111 the normal bladder and cord bladder. J. Urol., 59: 439, 1948. h 2 Baumrucker, G. 0.: ·Management of t e paralyzed bladder. Arch. Surg., 66: 484, 194~. , Ross, J. C., Gibbon, N. 0. K. and Dam'.'nski, M.: Division of the external urethral sphmcter
EX'l'ERNAL SPHINC'l'ERO'l'OlVIY IN PARAPLEGICS
Formerly their technique was to use a cold punch procedure hut bleeding was such a problem that this approach was rapidly abandoned. Subsequently, by using the Collings knife and electrocautery, Ross and associates incised the posterolateral aspect of the urethra from the distal verumontanum through the external sphineter to a depth of 6 mm. Sixty of 65 patients were ren·· dered catheter-free. Of paramount importance is the fact that 32 of 40 patients were followed for several years and have remained on an external appliance. Smythe performed external sphincterotomy on 8 paraplegics and rendered 7 patients catheterfree.7 Furthermore, his urethral pressure studies demonstrate that the entire prostatic urethra may represent the functional zone of the external sphincter. To objectively demonstrate the effectiYeness of incising the external sphincter, pressures exerted by this muscle had to be measured. Simons inserted a balloon-tipped catheter into the membranous urethra and with distention of the balloon recorded on a microcystometer an average of 23 mm. Hg as the pressure exerted by external sphincter in the normal male subject. 8 Emanuel, using a somewhat similar technique, obtained a pressure of 28 mm. Hg as a normal pressure of the external sphincter. 9 Fichardt obtained a Yalue of 40 to 60 mm. Hg for that pressure exerted by the external sphincter in Bantu'H. 10 He noted that each patient had his own critical pressure that was cmrntant. in the treatment of the paraplegic bladder. Brit.
J. Urol., 30: 204, 1958.
4 Ross, J.C., Gibbon, N. 0. K. and Damanski, M.: Further experiences with division of the external urethral sphincter in the paraplegic. J, Urol., 89: 692, 1963. 6 Ross, J. C., Damanski, lvI. and Gibbon, N.: Resection of the external sphincter in the paraplegic-preliminary report. J. Urol., 79: 742, 1958, 6 _Ross, J.C., Gibbon, N. 0. and Damanski, JU.: Division of the external sphincter in the treatment of the neurogenic bladder. Brit. ,J. Surg., 54: 627,
1967. 7 Smythe, C. A.: External sphiucterotomy in the management of the neurogenic bladder: a preliminary report. J. Urol., 96: 310, 1966. 8 Simons, I.: Advances in the field of cystometry due to clinical studies with the sphincterometer. IV. Studies in bladder function (a preliminary report). J. Urol., 36: 88, 1936. 9 Emanuel, M .. A new dynamic catheter-type sphinct.erometer. J. Urol., 90: 237, 1963. • 1 ° Fichardt, T.: Scree11ing urethrocystography of adnlt Bantu males under manometric control; normal and pathological findings. Bril. J. Radio!.,
32: 120, 1959.
67
:\Ieasurements of the entire urethral resistance were obtained by Draper.11 He inserted a catheter into the urethra which had been connected to a Y-tube. One limb of the Y-tube was attached to a measuring device, the other to a source of saline. The fluid was elevated and the pressure recorded when there was a sudden increase in the rate of flow of the saline. The average retrograde urethral pressures in normal patients using this method were 48 to 73 mm. Hg. Draper noted excellent correlation !Jet,veen the anterograde and retrograde urethral pres,;ures. Lapides' method of determining the normal pressures exerted by the external sphincter is to fill the bladder with 250 cc saline, insert a catheter just distally to the area in which a pre~sure value is to be obtained and record the pressure when the saline ceases to flow in a retrograde fashion through the urethra. 12 With his method the normal external sphincter pressure in male subjects was 42 mm. Hg. Furthermore, he noted that the highest resistances to flow were in the 2 cm. area near the striated muscle in both female and male patients with or without anesthesia. Chute, using air in a similar manner to Draper, obtained a value of 85 to 124 mm. Hg as the normal JJressure of the external sphincter. 13 It is apparent that the discrepancies in the values for the external urethral pressures are most likely due to the various methods of measurement. Retrograde urethral pressures have not been recorded in a large series of cord injury patients. Our method not only measures the pressure exerted by the external sphincter but also those pressures exerted by the elastic tissue and the smooth muscle of the prostatic and penile urethra, the bladder neck, the viscosity of the saline and the turbulence of flow through the urethra. In paraplegics with spinal cord damage resulting in an upper motor neuron lesion the average preoperative retrograde urethral pressure -was .54.8 mm. Hg. However, often with pelvic spasm the pressure rose to more than 100 mm. Hg. In u Davis, J.E., Morillo, J\L and Draper, J. vV. J\Ieasurements of urethral resistance. J. Urol., 85: 586, 1961. 12 Lapides, J., Ajemian, E. P., Stewart, B. II., Breakey, B. A. and Lichtwardt, J. R.: Fnrther observations on the kinetics of the nrethrovesical sphincter. J. Urol., 84: 86, 1960 . 13 Kleeman, F. J. and Clrnte, R. A.: A plan for the evaluation of patients with bladder dvsfuuction and the use of pudenda] neurectomv in selected cases . .J. Ural., 97: 1029, 1967 ·
68
CURRIE AND ASSOCIATES
those patients with lower motor neuron lesions the average preoperative retrograde urethral pressure 1rns 40 mm. Hg. This demonstrates that sphincter pressures in paraplegics with lower motor neuron lesions are lower than those with a reflex bladder. Yet the pressures arc of such a degree as to cause obstruction due to concomitant lmY bladder pressures. In patients who had 1, 2 and enn 3 resections of the bladder neck the preoperative and postoperative sphincterotomy retrograde urethral pressures were not dissimilar to those who hacl not had a prior operation on the bladder neck. ·when the preoperative pressure graphs showed the retrograde methral pressure was greater than the maximum -vesicul pressure the patient could not Yoid spontaneously (fig. 3). vVhcn the pressures were similar the patient voided. However, the patient had significant residual, i.e. more than 90 cc. The majority of preoperative cystourethrograms demonstrated a widely patent bladder neck regardless of the level of the lesion. This correlates well with Ascoli's findings vthich noted that in 69 per cent of paraplegics, cystourethrograms clemonstratecl a widely dilated bladder neck. 14 Furthermore, the same cystourethrograms demonstrated obstruction at the external sphincter in 48 of 55 cases. A narrowing of the dye stream was noted in the area of the external sphincter in almost all patients admitted to this study. This finding was more pronounced iu patients with an upper motor neuron lesion. Postsphincterotomy the contracture was absent. Thus, with no apparent obstruction one is hardpressed to condone excision of the bladder neck to relieve obstruction which was not present. The etiology of reflux in paraplegics is not in the scope of this paper. However, most investigators believe that reflux results from a combination of infection and increased intravesical pressure. The Foley catheter, although beneficial in reducing bladder pressure by reducing urethral resistance, acts as a focus of infection in the bladder and urethra. External sphincterotomy like,Yise decreases outlet obstruction while at the same time a nidus of persistent infection is eliminated. In this series 7 of 10 patients had complete disappearance of reflux. An additional patient had a marked decrease in reflux postoperatively. In 2 patients reflux had been present 14 As coli, R.R.: Radiological study of the vesical neck in paraplegia secondary to spinal cord injury. Paraplegia, 4: 235, 1967.
for more than 2 years. It is postulated that in these cases irreversible changes had occurred. Postoperatively, "'e have had the opportunity to perform cystoendoscopy on several patients in our study. The incision in the external sphincter is well epithelizecl, it has the appearance of a scarred open tube and there appears to be no obstruction to the free flow of the irrigating fluid through the urethra. Immediate results in our first 85 patients are encouraging. However, to be effective a new technique must stand the test of time. We have evaluated 30 patients who are at least 4 months post-sphincterotomy and 23 patients are catheter-free. Of the 7 patients still on catheter drainage, 2 prefer the catheter because of ease of care, 2 had persistent ureterovesical reflux and chose catheter drainage rather than the Crede maneuver. Therefore only 2 patients may be considered failures. These patients are on catheter drainage because of high residual urine. In both cases the postoperative retrograde urethral pressures were decreased when compared to the preoperative level yet there was little difference between the 2 values. vVe postulate that the sphincter was incompletely incised and that a repeat sphincterotomy would be beneficial. COKCLUSION
Indications for external sphincterotomy m patients with an upper or lo"·er motor neuron bladder are the requirement of urethral catheter drainage due to an inability to void, a high residual urine and/ or early vesicoureteral reflux. The procedure is successful because it lowers the pressure created by the external sphincter to a value below the maximum vesical pressure. Furthermore, external sphincterotomy reduces the effects of asynchronous contractions of the spastic pelvic musculature. Eight-five patients with spinal cord injury and resultant neurogenic bladders were rendered catheter-free immediately following incision of the external sphincter. Cystourethrograms demonstrated obstruction to the flow of contrast material to be in the area of the external sphincter and not at the bladder neck. This pictorial area of obstruction was not present in the postoperative cystourethrograms. Reflux was reduced or eliminated in 8 of 10 patients. The operative technique is easily performed, the complications are few and the results are immediate and impressive.