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ProACT is an extra urethral bulking system made of a silicone balloon connected with a dual lumen tubing (12–14 cm) to a titanium scrotal port that allows the postoperative adjustment (Fig. 6.1). It was introduced in the European market in 2000 as the first non-circumferential compressive device. The continence mechanism is guaranteed by a bilateral compression of the urethra, augmenting maximum urethral closure pressure (MUCP). In a study by Reuvers et al. this mechanism was demonstrated in a cohort of 23 successfully implanted patients in which a significant increase in MUCP from 58 cmH2O to 79 cmH2O was observed [1].

The pelvic floor has been poorly studied from a biomechanical perspective probably because of its complex structure comprised of many muscle layers and multiple muscle insertions with concave format in a three-dimensional architecture. An objective assessment of the pelvic floor muscles' (PFM) physical and mechanical capabilities is highly recommended to document changes in PFM function throughout rehabilitation protocols. Besides the magnitude of PFM force-generating capacity, other force/pressure-related parameters are important for the continence mechanism and sexual function, which are also correlated to different urogynecological dysfunctions. The existing devices for PFM assessment can be classified as manometers, dynamometers, electromyographers, or imaging techniques. So far, there is no perfect instrument or gold standard; however, each method has its advantages and disadvantages, and some of them will be discussed in this chapter. Recently, a new objective and reliable mechanical tool has been developed, being capable of measuring the magnitude and spatiotemporal distribution of pressures along the vaginal canal, taking into account the PFM structure, the directions of PFM contractions, and its ventro-cephalic resultant force. In this chapter, this device will be described and some of its clinical applications will be shown.

INTRODUCTION AND HYPOTHESIS: The premise of midurethral sling (MUS) surgery is to apply a tension-free vaginal tape in the midurethra that does not constrict the urethra at rest but stabilizes the urethra and prevents downward descent and opening of the urethra during stress maneuvers, but current technology has limitations in measuring urethral pressures during dynamic conditions. Our objective was to describe the change in maximum urethral closure pressures (MUCPs) after MUS surgery using an 8-French high resolution manometry system (HRM) that can measure urethral pressures during cough and strain maneuvers (ManoScan® ESO, Given Imaging) without migration or withdrawal limitations. METHODS: We measured rest, cough, and strain MUCPs in 26 women before and after retropubic or transobturator MUS for stress urinary incontinence using the HRM system. RESULTS: The objective success rate after MUS was 92.3% based on postoperative cough stress testing. Mean resting MUCPs measured by HRM did not change after surgery (59.3 preop vs 59.7 cm H(2)0 postop) (p = 1.0). Mean cough MUCPs measured by HRM increased from 36.9 to 100.7 cm H(2)0 (p < 0.001), and strain MUCPs increased from 35.0 to 92.7 cm H(2)0 (p < 0.001). CONCLUSIONS: Advanced HRM technology to measure MUCPs under cough and strain conditions without withdrawal techniques provides new insights into the continence mechanism after tension-free MUS: MUCPs do not change at rest but do increase significantly during cough and strain maneuvers.

Objective To evaluate in a rabbit experimental model a mechanism of continence of catheterizable urinary conduits (CUC), focusing on the behavior of intersected rectal muscle fibers in relation to the channel by histological and histochemical analysis, and secondarily to register conduit continence rates from clinical and urodynamic data. Materials and methods 12 rabbits were submitted to construction of a CUC from two abdominal skin flaps and divided into two groups: 8 with a urinary neo-sphincter created according to Yachia and 4 controls. We registered clinical outcome, urodynamic studies and microscopic analysis of CUC on the surface of the conduit, which was in direct contact with the mechanism of continence. We took muscle samples from the mechanisms of continence and performed histochemical evaluation by enzymatic reactions. Results Histological evaluation of the CUC showed no difference between groups. Histology and immunohistochemistry of the muscle fibers showed that areas of necrosis, cell atrophy and motor neuron injury from the first eight weeks recovered by the end of 16th week. Conduit complications occurred in 4 animals (33%). The average detrusor leakage point pressure through the conduit was 90 cm H 2 O versus 39 cm H 2 O through the urethra. Conclusion The mechanism of continence did not promote ischemic stress on the conduit, was able to promote high pressure resistance and showed good recovery of intersected muscle fibers, after an initial slight atrophy, suggesting good durability of the neo-sphincter.

Continent cutaneous urinary diversion (CCUD) utilizes an intestinal segment to create a low-pressure urinary reservoir and a catheterizable continence mechanism. It provides a urinary tract reconstruction option for patients who are not candidates for continent orthotopic urinary diversion and in patients with whom an ileal conduit is not desirable. The ideal candidate for a CCUD is the same patient who would be considered for orthotopic neobladder but may not have a usable urethra. In this chapter, we describe the surgical technique used for the most commonly used CCUDs.

Use of mid-urethral slings to treat stress urinary incontinence is based on the integral theory that the mid-urethra has an important role in the continence mechanism. Transobturator vaginal tape (TOT) involves passage of the sling transvaginally through the obturator foramen so as to avoid the pelvic organs and vasculature. In this report, we describe the operative steps of the transobturator approach.

Shorter urethral sphincter length on preoperative endorectal magnetic resonance imaging has been associated with an increased risk of postoperative urinary incontinence as well as longer time to achieve continence. We determined that our techniques of anatomical reconstruction for restoring the continence mechanism could markedly improve continence outcomes, especially in patients with a shorter urethral sphincter.Our cohort consisted of 274 patients who underwent robotic radical prostatectomy, as performed by a single surgeon, and for whom preoperative magnetic resonance imaging and postoperative evaluations were available. All sphincter lengths were measured on T2-weighted images as the distance from the prostatic apex to the penile bulb, cross-referencing all 3 planes. Continence was defined as zero pads or a liner used for security reasons only.The 2 surgical modifications considerably hastened the return of continence at 6 months. The continence rate in the shorter sphincter group (less than 14 mm) was 47% for the control technique, 81% for anterior reconstruction and 90% for total reconstruction. The continence rate in the longer sphincter group (more than 14 mm) was 80% for the control technique and 83% for anterior reconstruction, while it approached 99% for total reconstruction. With the control technique the average time to achieve continence was significantly different between the shorter and longer sphincter groups (25 vs 12 weeks, p = 0.037). The significance disappeared for anterior reconstruction (7.4 vs 6.2 weeks, p = 0.27) and total reconstruction (3.6 vs 2.7 weeks, p = 0.13).The results of this study are encouraging for patients with a short urethral sphincter who are considering radical prostatectomy.

Neurophysiologic function of the continence mechanism in the male has been largely focused on voiding difficulties and directed to explore the obstruction instead of incontinence. Over the past 20 years, much has been elucidated about the pathophysiology of male SUI. As improved diagnostic modalities have provided new insight into the function and dysfunction of the urethral continence mechanism, theories have evolved from being purely anatomic to being both functional and anatomic.

To reevaluate the submucosally embedded in situ appendix as continence mechanism in a large single institutional series of ileocecal urinary reservoirs.Between November 1990 and June 1999 an ileocecal reservoir with appendico-umbilical stoma was created in 118 patients (84 men, 34 women) aged 3.9-82.7 (mean 56.8) years as a primary urinary diversion or after failure of previous reconstruction. The most common indication for urinary diversion was bladder replacement after anterior exenteration for pelvic malignancies (n = 98), followed by functional or morphological bladder loss due to various benign conditions. The patients were followed prospectively according to a standard protocol.There were no perioperative deaths. In 3 patients necrosis of the appendix resulted in total incontinence with subsequent replacement by an intussuscepted ileal nipple. Impaired catheterization due to stomal stenosis was observed in 19 patients with recurrence in 6 and a total of 25 minor revisions. With a mean follow-up of 60 months all patients are continent day and night.Over 10 years, the submucosally embedded in situ appendix has survived as a continence mechanism in the original technique reliably providing continence in ileocecal reservoirs.

To evaluate urodynamic findings in a successful flap valve (FV) continence mechanism in association with a continent colonic urinary reservoir (Florida pouch) and to compare the urodynamic findings of the FV mechanism with the doubly plicated (PI) standard anti-incontinence segment in the same reservoir.Thirteen patients who successfully received the Florida pouch between 1988 and 1996 agreed to undergo urodynamic evaluation as part of a pilot study. Eight patients had a PI continence mechanism and a mean time from surgery of 51 months; 5 had a FV continence mechanism and a mean time from surgery of 14 months. Enterocystometry was performed with a trans-stomal Bard triple channel 7F catheter. Volume and pressure at first desire to empty (VFDE, PFDE), as well as maximal enterocystometric capacity and pressure (VMEC, PMEC), were recorded. Maximal outlet pressure (MOP) was recorded using the catheter withdrawal technique.PI and FV groups demonstrated the following mean values respectively: VFDE, 692.7 and 403 mL; PFDE, 19.5 and 19.2 cm H2O; VMEC, 876.5 and 515 mL; PMEC, 25.9 and 24.6 cm H2O; MOP, 57.5 and 51.2 cm H2O (reservoir empty) and 50.5 and 52.6 cm H2O (reservoir full); and functional length of outlet, 24.3 and 24.6 cm. MOP measurement demonstrated greater variability in the PI than in the FV group.Urodynamic comparison of these mechanisms reveals that MOP measurement was closer to the mean among FV than PI patients. In addition, the mean VFDE (692.7 mL for PI versus 403 mL for FV, P0.05) and the mean VMEC (876.5 mL for PI versus 515 mL for FV, P0.05) were significantly less in the FV group. Lower VMEC and less variability in MOP indicate that continence may be more dependent on MOP in the FV mechanism. A longer follow-up time and a larger number of patients will be of assistance in clarifying these findings.

We undertook this study to evaluate the mechanism of continence in women who underwent modified radical cystectomy and creation of an ileal neobladder. Our surgical technique was modified in accordance with detailed anatomic dissection of female pelvises with attention to the innervation of the pelvic musculature and urethral sphincter. Ten women aged 41-71 years (mean 64.3 years) underwent nerve-sparing radical cystectomy and creation of an orthotopic neobladder with detubularized ileum. Videourodynamic evaluation was performed 6 months postoperatively to evaluate sphincteric and reservoir function. Seven of the ten patients were totally continent after the procedure, requiring no protective pad. Of these, one requires intermittent self-catheterization. Videourodynamic evaluation revealed a low-pressure reservoir with a mean capacity of 467 ml, and leakage did not occur during Valsalva maneuver. Three patients reported significant incontinence (more than one pad per day) after orthotopic reconstruction. These patients demonstrated intrinsic sphincteric deficiency with a low mean abdominal leak-point pressure of 48.3 cmH2O. Two of these women had stress incontinence preoperatively. In conclusion, continence can be preserved in most women after modified radical cystectomy and orthotopic bladder replacement. Success results from preservation of the intrinsic sphincteric mechanism and the creation of a low-pressure, compliant reservoir. A history of stress incontinence preoperatively appears to predispose to sphincteric weakness postoperatively.

Purpose: We present a time and labor saving embedding technique for a full-thickness bowel flap tube used as a continent outlet.Materials and Methods: In 17 patients the bowel flap tube was extramurally embedded instead of being submucosally tunneled. The reservoir was attached to the abdominal wall to reinforce the continence mechanism and prevent the tunnel from opening.Results: All 17 patients are completely continent and 14 of 16 evacuate urine easily with a 14F catheter. Due to recurrent stomal stenosis 1 patient with severe diabetes has undergone incontinent diversion.Conclusions: Our described tunneling procedure for the full-thickness bowel flap tube is easy to perform and provides excellent continence.

Transrectal sonography of the bladder and urethra was performed to investigate urethral conditions in 296 women (191 with stress urinary incontinence, 78 with frequency-urgency syndrome, and 27 who were asymptomatic). Patients with stress urinary incontinence showed larger pubovesical angle during both resting and straining states than those with either frequency-urgency syndrome or those who were asymptomatic. Pubovesical length did not vary among the three groups of women. Five types of stress urinary incontinence were classified according to the four findings of transrectal sonography: hypermobility of the bladder neck, bladder neck incompetence, urethral sphincteric incompetence, and the presence of a cystocele. Of the patients with frequency-urgency syndrome, 55.1% showed bladder neck incompetence, whereas only 29.6% of the asymptomatic women did. Of the patients with frequency-urgency syndrome, nine had urethral sphincteric incompetence and one had a cystocele. none of the asymptomatic women had any of these disorders. However, the presence of bladder neck incompetence did not correlate well with the presence of clinical symptoms. Transrectal sonography could not differentiate symptoms caused by the bladder from those caused by the urethra. Although a large overlapping of pubovesical angle size was noted among the groups of women, the angle was largest in those with stress urinary incontinence, second largest in those with frequency-urgency syndrome, and smallest in those who were asymptomatic. These findings held true during both resting and straining. Bladder neck incompetence was often associated with a weak extrinsic continence mechanism, as was demonstrated by pubovesical angle changes in both frequency-urgency syndrome patients and asymptomatic women. Urethral sphincteric incompetence was not present in asymptomatic women but could be found in 12.8% of those with frequency-urgency syndrome.

Objective: The suburethral fibromuscular layer (SUFML) contains nonvascular smooth muscle that may play an important role in the continence mechanism. This study was undertaken to develop a method to systematically quantify differences in the thickness and density of nonvascular smooth muscle within the SUFML and to demonstrate its use in assessing variation. Study Design: Urethral and anterior vaginal wall sections from the urethrovesical junction of fresh cadavers were stained to define alpha actin in smooth muscle cells. The thickness of the SUFML was microscopically measured and the density of the nonvascular smooth muscle was determined with computer-aided analysis. Results: The mean thickness of the SUFML was 3.04 mm (range 1.74-3.78 mm, SD ±0.63 mm). The mean density of nonvascular smooth muscle within it was 17.94% (range 10.48%-42.84%, SD ±9.4%). The mean age was 55 years (range 36-69 years, SD ±10.75 years). Conclusion: The thickness and density of the nonvascular smooth muscle within the SUFML can be quantified and there is variation among individuals. (Am J Obstet Gynecol 2003;188:1183-5.)

Introduction: A sufficient and easily catheterizable continence mechanism is essential in continent cutaneous pouches. Kälble embedded a tapered ileum as efferent segment into a serosal lined tunnel formed by an ileal ‘U’ according to the principle of Abol-Enein and Ghoneim. We report a modified technique applied in a series of 12 patients who had undergone different urinary diversions. Methods: All patients received a modified Kälble procedure (first-line urinary diversion, n = 8; revision/undiversion, n = 4) for different forms of continent pouches. To alleviate embedding of the efferent segment, ileal detubularization was performed asymmetrically. Mean follow-up was 9.5 months. Results: All patients were continent and performed self-catheterization easily. Of 12 patients, 2 underwent endoscopic incision for stomal stenosis 8 and 12 months postoperatively. Conclusions: Subject to our short follow-up, Kälble’s technique is a promising alternative in patients undergoing a continent cutaneous urinary diversion but offers an inapplicable or missing appendix.

Until now, anatomy of the lower urinary tract still persists for controversial discussion. Especially, the basis of the continence mechanism is still obscure. On the basis of our own exten...

We present our experience with a modified technique for constructing a continent ileal reservoir, using the terminal ileum in a pre-peritoneal position. The ureters were implanted using the Le Duc-Camey technique; the Benchekroun valve was used as a continence mechanism. This technique was used in 18 patients and its advantages and complications are discussed.

Although we have progressed very well in creating large capacity, low pressure reservoirs, the construction of a simple and reliable continent outlet still remains a problem. The appendix vermiformis serves well as a continence mechanism for either the bladder or intestinal reservoirs for urine. The different surgical techniques described in the literature are reviewed and discussed in this context. Moreover, we report on our clinical and experimental results of using the appendix during the Mainz pouch procedure for continent urinary diversion.

In an attempt to create continence in myelomeningocele children we performed urethral lengthening/submucosal reimplantation, a form of bladder neck reconstruction, to create a valve allowing catheterizable access to the bladder. We present the urodynamic findings of 23 patients 4 to 89 months (mean 43.1 months) after bladder neck reconstruction and enterocytoplasty to determine the continence mechanism of this 1-way valve and characteristics of the augmented bladder. Standard cystometrograms with simultaneous pressure recording of the submucosal portion of the neourethra were undertaken with a 10F, triple lumen, urethral pressure profile catheter. Baseline pressures in the submucosal neourethra were higher than in the bladder (mean 25.3 versus 13.4 cm, water, p less than 0.001). Submucosal tunnel and bladder pressures paralleled throughout filling, with mean tunnel pressures remaining greater at the time of first (53.6 versus 45.5 cm. water, p less than 0.01) and peak (62.9 versus 55.8 cm. water, p greater than 0.05) cystoplasty contractions. Bladders augmented with detubularized ileum had fewer significant contractions (greater than 40 cm. water) than other types of cystoplasties (36% versus 92%) and over-all they had first and peak contractions at greater volumes and lesser magnitude. We conclude that continence following urethral lengthening/reimplantation results from an anatomical arrangement allowing transmission of dynamic bladder pressure changes to the submucosal neourethra and that urethral pressure exceeds bladder pressure throughout filling. Additionally, our data suggest that detubularized ileum provides a large capacity, low pressure reservoir suitable for augmentation.

Purpose: To establish an animal model for studying the effects of vaginal trauma and oophorectomy on the continence mechanism in rats. Methods: Ninety-six female rats were used in the experiments. The rats were divided into 8 groups that received either no treatment (control), or single vaginal trauma at 0 day and 4 weeks, multiple vaginal traumas, oophorectomy at 4 and 12 weeks, and combined oophorectomy and single vaginal trauma or multiple vaginal traumas at 4 weeks. In vivo experiments were performed to determine abdominal leak point pressure (ALPP) by recording the intravesical pressure obtained during compression of the lower abdomen. In vitro urethral contractility experiments were then performed using isolated urethra and electrical field stimulation, acetylcholine, and norepinephrine. Finally, histological study of the urethral muscles and paraurethral structures was performed. Results: Single or multiple vaginal traumas resulted in a significant reduction of ALPP. The reduced ALPP recovered at 4 weeks after single vaginal trauma. Oophorectomy did not significantly affect ALPP compared to controls; however, when oophorectomy was combined with multiple vaginal traumas, a significant reduction in ALPP occurred. Urethral contractility was reduced after multiple vaginal traumas but was not significantly different from the control after oophorectomy. Histological studies revealed disruption of the ventral part of striated muscles after single or multiple vaginal traumas. Degenerative and hyalinization changes were noted in submucosal and muscle layers after oophorectomy combined with multiple vaginal traumas. Conclusions: Vaginal trauma can injure the urethral muscles and nerves. Single or multiple vaginal traumas can induce denervation of periurethral muscles and reduce ALPP. With a period of recovery, the urethral resistance increases and ALPP returns. Oophorectomy mainly affected the intrinsic urethral closure mechanism and resulted in a nonsignificantly reduced ALPP; however, a significant reduction of ALPP developed when oophorectomy was combined with multiple vaginal traumas.

Tapered terminal ileum and an intact ileocecal valve have been shown to be an effective efferent continence mechanism in patients with continent ileocecal urinary reservoirs. The terminal ileum can be tapered by simple suture plication or with linear gastrointestinal stapling devices. We used precise urodynamic techniques to study 21 continent urinary reservoirs constructed from ileocecal bowel segments: 14 with plicated segments and 7 with stapled segments. Mean contraction pressures tended to be higher in the latter (P = 0. 054), although maximum contraction pressures were similar (P = 0.48). Terminal ileum tapered with the gastrointestinal stapling device and an intact ileocecal valve provide for an effective efferent continence mechanism that is easy to construct and catheterize.

Background: H-type urethral duplication is the most complex form of this uncommon anomaly. Methods: This report describes the treatment of four such patients, three of which had hypoplasia of the entire anterior urethra, and one had anterior fusiform megalourethra. Results: Satisfactory results were obtained in all four by staged surgical management in which the anal opening was transposed to the perineum, preserving the continence mechanism. Subsequently, urethroplasty was performed. In one patient, the megalourethra was tailored and incorporated into the urethroplasty in a third-stage procedure. All patients were well on follow-up. Conclusion: With early treatment, good results can be achieved in this condition.

In the author's opinion, in the properly selected woman undergoing radical cystectomy for transitional cell carcinoma of the bladder, the ileal neobladder to the female urethra is a viable option. Ten years of experience with 23 patients have led to a nerve and urethral support cystectomy technique with the ileal neobladder anastomosed to the proximal urethra. Even then, however, retention in 20% of patients rather than the expected incontinence is the critical issue. Incontinence has never been a problem. The advent of orthotopic lower urinary reconstruction in women is a major achievement in the evolution of urinary diversion. With our increasing understanding of the continence mechanism in women and with increasing evidence that the female urethra can be safely preserved after cystectomy, orthotopic lower urinary tract reconstruction by the ileal neobladder can now be offered safely not only to men but also to women undergoing cystectomy with superb functional results.

Objective To evaluate the function of a continence mechanism in combination with a colonic urinary reservoir in a pig model. Materials and methods A colonic urinary reservoir was constructed as a bladder augmentation in six domestic pigs. The pouch was connected to a narrowed and tunnelled ileal tube as a continence mechanism. The closure pressure was measured intra-operatively and 3 months post-operatively. Results The mean difference between the pressure in the continence mechanism and in the reservoir was 74 cmH2O (range 50–100). Continence was complete both intra-operatively and 3 months post-operatively. Conclusion The modified narrowed and tunnelled ileal tube is a safe continence mechanism when combined with a colonic urinary pouch.

By creating continent supravesical diversions or continent vesicostomies, various methods of continence mechanism can be distinguished. They all are based on the principle that the pressure in the conduit is higher than in the reservoir. Twenty-eight patients with various urinary diversions and different continence mechanisms were followed up by clinical investigation, questioning and urodynamic evaluation. The latter showed similar results with regard to efferent loop pressure. The best results concerning easy catheterization and safe continence are reached by appendix stoma and tapered ileum.

Use of the in situ appendix to provide continence was evaluated in 21 adults undergoing continent urinary diversion. The appendix with minimal or no manipulation was used in 20 of the 21 adults to provide the continence mechanism. Our findings indicate that in the majority of adults with no prior appendectomy the unaltered or minimally altered appendix is suitable to provide continence, and that dilating a narrow appendix is safe, effective and compatible with providing an adequate continence mechanism.

Malfunction of the outlet mechanism, that is leakage of urine or difficulty in catheterization, has been the main problem in the evolution of continent urinary reservoirs. Urinary leakage in 3 patients with a right colonic reservoir (2 with an intussuscepted ileal nipple valve and 1 with a plicated ileal segment as a continence mechanism) was managed with tapered narrowing of the nipple valve and the ileocecal valve, respectively, using stapling techniques. Continence was thereby reestablished without impeding catheterization. Tapering is easy to perform and, when applicable, can obviate the need for a major surgical procedure.

It is customary to divide the lower intestine into three constituent parts — colon, rectum and anus. While the colon is intimately linked in functional terms to the control of continence, it has no relevance to the structural factors that govern the control of anal continence. However, the same is not true for the rectum and anus: both are vital to the structural basis by which the body governs defaecation. Because of this strong interrelationship between the rectum and anus it is best that the anatomy and the physiology of the continence mechanism are regarded as belonging to one unit — the ano-rectum.

The continence mechanism of the female urethra has been investigated by a method that makes possible simultaneous recording of an induced intraurethral pressure and the related cross-sectional area. Muscular work, power and velocity of contraction could be calculated on the basis of these recordings at rest and during voluntary contractions of the pelvic floor. With these parameters it was possible to demonstrate 2 different components in the continence function: one in the mid urethra that maintains the closure pressure at rest and another more proximally in the urethra that is capable of fast, powerful contractions.

In 71 children on whom surgery to improve continence was performed mainly because of severe anorectal atresia, an investigation was carried out to find out whether there was a relationship between the patients' age at the time of operation and post-surgical continence. It was found that both after transplantation of the gracilis muscle according to Pickrell and after free muscle transplantation, the results obtained improved the more, the older the children at the time of surgery, and the more active their participation had been in postoperative intensive stool training. However, the authors' hope has so far not materialised that stool training would become redundant by free muscular transplantation, due to the reflectory introduction of freely transplanted musculature into the continence mechanism and the resulting spontaneous innervation and activation of the muscle. This would have facilitated early performance of an operation to improve continence.

We report 3 cases in which the lower urinary tract was reconstructed using bowel. In each instance the cuff was placed around the bowel to provide a continence mechanism. The 2 patients in whom the sigmoid colon was used have sporadic diurnal incontinence with nocturnal enuresis. Urodynamic evaluation has shown that this is secondary to high pressures generated within the closed sigmoid loop. The ileocecocolonic segment is preferable for reconstruction of the lower urinary tract, since the pressure developed within the bowel is significantly lower. The use of the artificial urinary sphincter around the bowel extended the versatility of the device.

Controversy about the basic nature of urethral function does not preclude accurate clinical assessment of disorders of function. While the precise method of treatment of urethral continence dysfunction varies from institution to institution, the basic techniques are quite similar. It is the application of a treatment method to a particular case which causes difficulty. It is important, therefore, to have some understanding of the functional elements in the urethral continence mechanism to be able to determine which element does not function. Most cases of intractable incontinence are associated with poor function of the involuntary part of the sphincter. In general, peak urethral closing pressures are unrelated to continence function unless there is no pressure at all.

The abdominal neourethra is a continent bladder tube that is applicable to selected children with anatomical urinary incontinence or urinary retention and a nonnavigable urethra. A 5 to 8-year followup is presented in 6 children in whom the abdominal neourethra afforded normal micturition through it or permitted intermittent catheterization. All children were dry between bladder emptyings as a result of a continence mechanism that combined a long elastic tube and a cephalad neourethral abdominal opening with a rectus striated muscle sphincter.

Thermal sensation is thought to be important in sensory discrimination between different substances. The aim of this study was to determine the thermal sensitivity in the anal canal in continent patients with hemorrhoids (N = 20), a group that has been reported to have a sensory deficit, and to compare the results with control subjects (N = 40) and patients with idiopathic fecal incontinence (IFI) (N = 22). Anal manometry was performed and sensation to mucosal electrostimulation and temperature change in the lower, middle, and upper zones of the anal canal assessed. Thermal sensation was impaired in the hemorrhoid group as compared with controls, but not to the same degree as in IFI (e.g., median thermal sensitivity in mid anal canal, control 0.9 degrees C, hemorrhoid 1.2 degrees C, IFI 2.0 degrees C, P less than .05 and less than .001, respectively). The correlation between the two tests of sensation was 0.54 (P less than .001) and the reproducibility of thermal sensory thresholds was 0.82 (P less than .001). In conclusion, patients with hemorrhoids have a mild anal sensory deficit, but continence in this group is likely to be augmented by other factors.

Summary The anal canal is lined by cushions of specialized submucosal tissue which assist the continence mechanism. Starting with that premise, its various afflictions are examined and found to be more logically related, and much more readily understood.