Female Stress Urinary Incontinence Clinical Guidelines Panel summary report on surgical management of female stress urinary incontinence. The American Urological Association

PURPOSE

The American Urological Association convened the Female Stress Urinary Incontinence Clinical Guidelines Panel to analyze the literature regarding surgical procedures for treating stress urinary incontinence in the otherwise healthy female subject and to make practice recommendations based on the treatment outcomes data.

MATERIALS AND METHODS

The panel searched the MEDLINE data base for all articles through 1993 on surgical treatment of female stress urinary incontinence. Outcomes data were extracted from articles accepted after panel review. The data were then meta-analyzed to produce outcome estimates for alternative surgical procedures.

RESULTS

The data indicate that after 48 months retropubic suspensions and slings appear to be more efficacious than transvaginal suspensions, and also more efficacious than anterior repairs. The literature suggests higher complication rates when synthetic materials are used for slings.

CONCLUSIONS

The panel found sufficient acceptable long-term outcomes data (longer than 48 months) to conclude that surgical treatment of female stress urinary incontinence is effective, offering a long-term cure in a significant percentage of women. The evidence supports surgery as initial therapy and as a secondary form of therapy after failure of other treatments for stress urinary incontinence. Retropubic suspensions and slings are the most efficacious procedures for long-term success (based on cure/dry rates). However, in the panel's opinion retropubic suspensions and sling procedures are associated with slightly higher complication rates, including longer convalescence and postoperative voiding dysfunction.

Stress incontinence: classification and surgical approach

We present a modified classification for stress urinary incontinence based on the nature of vesical neck descent and the integrity of the intrinsic sphinteric mechanism. Surgical treatment was undertaken in 72 patients with this classification. With a minimum followup of 18 months there was a 94 per cent cure rate with respect to stress incontinence. However, in 14 patients significant frequency and urgency developed, which persisted for at least 6 months postoperatively. Of these patients 13 had undergone a pubovaginal sling procedure, 3 of whom had refractory symptoms, including urge incontinence, which resulted in augmentation cystoplasty in 2 and supravesical urinary diversion in 1.

Bladder outlet obstruction nomogram for women with lower urinary tract symptomatology

The aim of our study was to construct a bladder outlet obstruction nomogram for women with lower urinary tract symptoms. A urodynamic database of 600 consecutive women was reviewed. Bladder outlet obstruction, utilizing strict diagnostic criteria, was diagnosed in 50 (8.3%) patients. A comparison of patient characteristics, uroflowmetry, and detrusor pressure-uroflow studies was carried out between the obstructed patients (mean age, 64.4 +/- 17.6 years) and 50 age-matched unobstructed controls (mean age, 64.8 +/- 10.7 years). Maximum flow rates were significantly higher in free uroflow studies (free Qmax) than in pressure-flow studies (Qmax), in both obstructed (9.3 +/- 3.7 versus 5.7 +/- 3.6 mL/s, respectively. P = 2. 6 10(-6)) and unobstructed (25.6 +/- 11.2 versus 11.8 +/- 5.9 mL/s, respectively. P = 8.7 10(-12)) patients. Comparison of detrusor pressure at maximum flow (pdet.Qmax) and maximum detrusor pressure during voiding (pdet.max) values did not reveal significant differences, in both obstructed (39.3 +/- 18.4 versus 49.7 +/- 25.5 cm H(2)O, respectively) and unobstructed (16.5 +/- 8.4 versus 20.6 +/- 9.2 cm H(2)O, respectively) patients. Further statistical analysis was carried out to construct bladder outlet obstruction nomogram. The nomogram classifies any pair of values of free Qmax and pdet.max into one of the following four zones: no obstruction, mild obstruction, moderate obstruction, and severe obstruction. Of the 50 obstructed women, 34 (68%) were classified by the nomogram as mildly, 12 (24%) as moderately, and 4 (8%) as severely obstructed. A positive correlation was found between subjective severity of the symptoms (assessed by the AUA Symptom Index score) and the four nomogram zones. In conclusion, the nomogram makes it possible to differentiate between obstructed and unobstructed women and between various degrees of obstruction. We believe the nomogram may also serve as an instrument to assess treatment outcomes.

The neurophysiology of micturition: a clinical study of 550 patients

Detailed urodynamic and neurologic evaluation of 550 patients was reviewed with the intention of shedding light on the understanding of the neurophysiologic pathways involved in micturition. On the basis of our data the following conclusions were made: 1) normal micturition is a brain stem reflex rather than a simple sacral reflex, 2) interruption of this sacral-to-brain stem reflex pathway results in uncoordinated voiding (detrusor-external sphincter dyssynergia), 3) anatomically separate neural centers control the activity of the detrusor muscle and the external urethral sphincter, and 4) although the pudendal and pelvic nuclei are located in the sacral spinal cord they are anatomically separable from one another.

Urodynamic findings in patients with diabetic cystopathy

To ascertain the relationship between voiding dysfunction associated with diabetes and bladder and sphincter behavior, the video urodynamic studies of 182 patients were retrospectively analyzed. Patients were classified based on urodynamic diagnosis and the presence or absence of signs of sacral cord involvement. Urodynamic findings were classified as either detrusor hyperreflexia, impaired detrusor contractility, detrusor areflexia, indeterminate and normal. The results indicate that mean bladder capacity was 485 +/- 89.3 ml. with a mean first sensation of filling of 298 +/- 67.4 ml. Of the 182 patients 100 (55%) had detrusor hyperreflexia, 42 (23%) had impaired detrusor contractility, 20 (11%) had indeterminate findings, 19 (10%) had detrusor areflexia and 1 (1%) was normal. Bladder outlet obstruction occurred in 66 patients (36%), all men (57%). The diagnosis was isolated in 24 patients (36%) or in combination with another diagnosis in 42 (74%). However, if one considers the presence of sacral cord signs (42 patients), the most common urodynamic diagnoses were either impaired detrusor contractility in 21 (50%) or detrusor areflexia in 10 (24%). These data suggest that classical diabetic cystopathy is not the most common urodynamic findings in patients with diabetes mellitus and voiding dysfunction, and in fact these patients present with variable pathophysiological findings. These findings demonstrate the importance of urodynamic studies in diagnosing voiding dysfunction in diabetics before initiation of therapy.

Pubovaginal fascial sling for the treatment of complicated stress urinary incontinence

We reviewed retrospectively 67 consecutive women with complicated stress incontinence who underwent a pubovaginal fascial sling procedure by a single surgeon. A detailed micturition questionnaire was completed at the last followup, which ranged from 1 to 8 years, with a mean of 3.5 years. Postoperatively, 82% of the women claimed that they were never incontinent and never wore pads, while 9% were incontinent less often than once per 2 weeks and 9% 9% continued to have troublesome incontinence on a daily basis. Only 2 of these women had persistent stress incontinence; the remainder (5) had urge incontinence. In 6 patients with a neurogenic bladder postoperative urinary retention was expected and they were treated with intermittent self-catheterization. Two patients had urethral obstruction by the sling and required prolonged (probably permanent) intermittent self-catheterization.

Bladder outlet obstruction in women: definition and characteristics

The prevalence of bladder outlet obstruction in women is unknown and most probably has been underestimated. Moreover, there are no standard definitions for the diagnosis of bladder outlet obstruction in women. Our study was conducted to define as well as to examine the clinical and urodynamic characteristics of bladder outlet obstruction among women referred for evaluation of voiding symptoms. Bladder outlet obstruction was defined as a persistent, low, maximum "free" flow rate of <12 mL/s in repeated non-invasive uroflow studies, combined with high detrusor pressure at a maximum flow (p(det.Q)(max) >20 cm H(2)O) during detrusor pressure-uroflow studies. A urodynamic database of 587 consecutive women identified 38 (6.5%) women with bladder outlet obstruction. The mean age of the patients was 63.9 +/- 17.5 years. The mean maximum "free" flow, voided volume, and residual urinary volume were 9.4 +/-3.9 mL/s, 144. 9 +/- 72.7 mL, and 86.1 +/- 98.8 mL, respectively. The mean p(det. Q)(max) was 37.2 +/- 19.2 cm H(2)O. Previous anti-incontinence surgery and severe genital prolapse were the most common etiologies, accounting for half of the cases. Other, less common, etiologies included urethral stricture (13%), primary bladder neck obstruction (8%), learned voiding dysfunction (5%), and detrusor external sphincter dyssynergia (5%). Symptomatology was defined as mixed obstructive and irritative in 63% of the patients, isolated irritative in 29%, and isolated obstructive in other 8%. In conclusion, bladder outlet obstruction in women appears to be more common than was previously recognized, occurring in 6.5% of our patients. Micturition symptoms relevant to bladder outlet obstruction are non-specific, and a full urodynamic evaluation is essential in making the correct diagnosis and formulating a treatment plan.

Bladder outlet obstruction versus impaired detrusor contractility: the role of outflow

The uroflow curves of 45 men with either bladder outlet obstruction or impaired detrusor contractility were retrospectively reviewed. The definitive diagnoses were attained by clinical and video-urodynamic studies with simultaneous detrusor pressure and uroflow measurements. Eight parameters were analyzed to determine if uroflow can differentiate obstruction from impaired contractility. There were no differences between the 2 groups in any of the parameters. This finding suggests that uroflowmetry as a single examination cannot distinguish between bladder outlet obstruction and impaired detrusor contractility.

Bladder and sphincter behavior in patients with spinal cord lesions

To ascertain the relationship between the clinical neurological level, and bladder and sphincter behavior, the video-urodynamic studies of 489 patients with spinal cord lesions due to a variety of causes were retrospectively analyzed. Patients were classified based on the clinical neurological level, etiology of the lesion and presence or absence of signs of sacral cord involvement. Urodynamic findings were classified as either detrusor hyperreflexia, detrusor-external sphincter dyssynergia, detrusor areflexia or normal. The results indicate that although there was a general correlation between the neurological level of injury and the expected vesicourethral function, it was neither absolute nor specific. For example, 20 of 117 cervical cord lesions had detrusor areflexia, 42 of 156 lumbar cord lesions had detrusor-external sphincter dyssynergia and 26 of 84 sacral cord had either detrusor hyperreflexia or detrusor-external sphincter dyssynergia. However, if one considers the presence of neurological abnormalities, 84% of the suprasacral cord lesions with detrusor areflexia have sacral cord signs. In contrast, all suprasacral cord lesions with no evidence of sacral cord involvement have either detrusor hyperreflexia or detrusor-external sphincter dyssynergia. The positive predictive value for positive sacral cord signs and detrusor areflexia was 87%. The positive predictive value for negative sacral cord signs and detrusor hyperreflexia/detrusor-external sphincter dyssynergia was 81%. These data suggest that the clinical neurological examination alone is not an adequate barometer to predict neurourological dysfunction and that video-urodynamic evaluation provides a more precise diagnosis for each patient.

Detrusor instability in men: correlation of lower urinary tract symptoms with urodynamic findings

PURPOSE

We evaluated the correlation of lower urinary tract symptoms suggestive of detrusor instability with urodynamic findings in men.

MATERIALS AND METHODS

Enrolled in our prospective study were 160 consecutive neurologically intact men referred for urodynamic evaluation of persistent lower urinary tract symptoms. All patients had storage symptoms suggestive of detrusor instability. Patients were further clinically categorized according to the chief complaint of urge incontinence, frequency and urgency, nocturia or difficult voiding. The clinical and urodynamic diagnosis in all patients as well as specific urodynamic characteristics of those with detrusor instability were analyzed according to the these 4 clinical categories.

RESULTS

Mean patient age was 61 +/- 15 years. The chief complaint was urge incontinence in 28 cases (17%), frequency and urgency in 57 (36%), nocturia in 30 (19%) and difficult voiding in 45 (28%). Detrusor instability was diagnosed in 68 cases (43%). A higher incidence of detrusor instability was associated with urge incontinence than with the other clinical categories (75% versus 36%, p <0.01). Of the patients 109 (68%) had bladder outlet obstruction, including 50 (46%) with concomitant detrusor instability. The prevalence of bladder outlet obstruction was similar in all patients regardless of the chief complaint. All other urodynamic diagnoses were also similar in the 4 clinical categories. The mean bladder volume at which involuntary detrusor contractions occurred were lower in patients with urge incontinence and frequency and urgency than in those with nocturia and difficult voiding (277.1 +/- 149.4 and 267.7 +/- 221.7 versus 346.7 +/- 204.6 and 306.2 +/- 192.1 ml., respectively, not statistically significant, p = 0.07).

CONCLUSIONS

Detrusor instability and bladder outlet obstruction are common in men with lower urinary tract symptoms. The symptom of urge incontinence strongly correlated with detrusor instability. Other lower urinary tract symptoms did not correlate well with any urodynamic findings. Therefore, we believe that an accurate urodynamic diagnosis may enable focused and more efficient management of lower urinary tract symptoms in men.

Nocturia in adults: etiology and classification

Nocturia is one of the most bothersome of all urologic symptoms, yet even a rudimentary classification does not exist. We herein propose a classification system of nocturia based on a retrospective study. The records of 200 consecutive patients with nocturia were reviewed. Evaluation included history, micturition diary (including day, night, and 24-hr voided volume), postvoid residual urine (PVR), and videourodynamic study (VUDS). Functional bladder capacity (FBC) was determined to be the largest voided volume in a 24-hr period. The etiology of nocturia was thus classified into one of three groups: nocturnal polyuria ([NP] in which voided urine volume during the hours of sleep exceeds 35% of the 24-hr output), nocturnal detrusor overactivity ([NDO] defined as nocturia attributable to diminished bladder capacity during the hours of sleep), and mixed (NP+NDO); polyuria (24-hr urine output >2,500 cc) was classified separately. There were 129 women and 65 men ranging in age from 17 to 94 years (x=59). Overall 13 (7%) had NP, 111 (57%) NDO, and 70 (36%) had a mixed etiology of their nocturia (both NP and NDO). Forty-five (23%) also had polyuria. These data confirm that the etiology of nocturia is multifactorial and in many instances unrelated to the underlying urologic condition. Nocturnal overproduction of urine is a significant component of nocturia in 43% of patients, most of whom will also have NDO. We believe that treatment should be directed at both conditions.

Detrusor-external sphincter dyssynergia: a detailed electromyographic study

We reviewed 54 cases of detrusor-external sphincter dyssynergia following complete urodynamic evaluations. All patients had well defined neurologic lesions of the suprasacral spinal cord. On the basis of urodynamic findings 3 types of dyssynergia were encountered: type 1 (30 per cent) was characterized by a crescendo increase in electromyographic activity that reached a maximum at the peak of the detrusor contraction, type 2 (15 per cent) consisted of clonic sphincter contractions interspersed throughout the detrusor contraction and type 3 (55 per cent) was characterized by a sustained sphincter contraction that coincided with the detrusor contraction. There was no correlation between the clinical neurologic level and the type of dyssynergia.

The bulbocavernosus reflex in urology: a prospective study of 299 patients

Bulbocavernosus reflex was evaluated clinically in 299 patients during a routine urodynamic evaluation and compared to the electromyographic demonstration of the reflex. The findings were correlated with the neurologic status of the patients. There were 127 patients who were normal neurologically, and 98 per cent of the male and 81 per cent of the female patients in this group had a normal bulbocavernosus reflex clinically. All of the male and 92 per cent of the female patients had a bulbocavernosus reflex demonstrated by electromyography. There were 73 patients with neurologic lesions involving the sacral spinal cord. All patients with a complete lesion had absent bulbocavernosus reflexes clinically and on electromyography, while 44 per cent of the patients with incomplete sacral lesions had an intact bulbocavernosus reflex clinically and 78 per cent had reflex demonstrated by electromyography. There were 99 patients with neurologic lesions of the spinal cord above the sacral outflow, and 90 per cent of this group had demonstrable bulbocavernosus reflexes clinically and 93 per cent had the reflex demonstrated by electromyography. It is concluded that the absence of a bulbocavernosus reflex in a male patient is indicative of a neurologic lesion involving the sacral spinal cord and is highly suggestive of such a lesion in a female patient. The presence of a normal bulbocavernosus reflex in either sex does not rule out the possibility of a significant lesion. The electromyographic demonstration of the bulbocavernosus reflex is more sensitive than the clinical one.

A new approach to electromyography of the external urethral sphincter

Detailed electromyographic investigation of the external urethral sphincter was done as part of a urodynamic evaluation of 119 patients. The sphincter was located by inserting electrodes alongside the urethra. The electromyogram was viewed on an oscilloscope and recorded on paper. Normal and abnormal sphincter electromyograms were defined and the role of sphincter electromyography in urodynamic studies was discussed. It was observed that electromyographic activity does not always correlate with urethral resistance but must be interpreted in conjunction with other urodynamic parameters, such as urethral pressures, urinary flow rates and voiding cystourethrography. In addition, sphincter electromyography provides valuable information to define the various neural pathways involved in micturition and continence.

Female Stress Urinary Incontinence Clinical Guidelines Panel summary report on surgical management of female stress urinary incontinence. The American Urological Association

PURPOSE

The American Urological Association convened the Female Stress Urinary Incontinence Clinical Guidelines Panel to analyze the literature regarding surgical procedures for treating stress urinary incontinence in the otherwise healthy female subject and to make practice recommendations based on the treatment outcomes data.

MATERIALS AND METHODS

The panel searched the MEDLINE data base for all articles through 1993 on surgical treatment of female stress urinary incontinence. Outcomes data were extracted from articles accepted after panel review. The data were then meta-analyzed to produce outcome estimates for alternative surgical procedures.

RESULTS

The data indicate that after 48 months retropubic suspensions and slings appear to be more efficacious than transvaginal suspensions, and also more efficacious than anterior repairs. The literature suggests higher complication rates when synthetic materials are used for slings.

CONCLUSIONS

The panel found sufficient acceptable long-term outcomes data (longer than 48 months) to conclude that surgical treatment of female stress urinary incontinence is effective, offering a long-term cure in a significant percentage of women. The evidence supports surgery as initial therapy and as a secondary form of therapy after failure of other treatments for stress urinary incontinence. Retropubic suspensions and slings are the most efficacious procedures for long-term success (based on cure/dry rates). However, in the panel's opinion retropubic suspensions and sling procedures are associated with slightly higher complication rates, including longer convalescence and postoperative voiding dysfunction.

Detrusor-external sphincter dyssynergia

Detrusor-external sphincter dyssynergia is characterized by involuntary contractions of the external urethral sphincter during detrusor contractions. A review of 550 consecutive patients who underwent urodynamic evaluation revealed that this condition was found only in patients who had involuntary detrusor contractions owing to well defined neurologic lesions of the suprasacral spinal cord. All patients with supracervical neurologic lesions had synergistic voiding patterns. We conclude that bladder-external sphincter dyssynergia is a neurologic condition owing to interruption of the spinal pathways connecting the pontine mesencephalic and the sacral micturition centers. In the absence of such a neurologic lesion one should be extremely cautious in making this diagnosis.

Vesicourethral dysfunction in multiple sclerosis

Urodynamic evaluation was done 45 times on 41 consecutive patients with multiple sclerosis. Bladder symptoms correlated poorly with any single urodynamic finding and, accordingly, a comprehensive evaluation was necessary to define the underlying pathophysiology. Only 63 per cent of the patients with symptoms of urgency, frequency and urge incontinence actually were found to have uninhibited bladder contractions, while 73 per cent of the patients with obstructive symptoms had detrusor areflexia. Six patients (15 per cent) had a marked change in urodynamic findings upon repeat examination either because of a change in symptomatology or poor response to treatment. An additional 6 patients had vesicoureteral reflux. Bladder symptoms in multiple sclerosis patients should serve more to alert the clinician to the need for urodynamic testing than to mandate specific treatment.

Evaluation of the etiology of nocturia in men: the nocturia and nocturnal bladder capacity indices

To determine and quantify the cause of nocturia in men, we describe and evaluate the relative contribution of two complementary indices of nocturia: the nocturia index (Ni), a measure of nocturnal urine overproduction, and the nocturnal bladder capacity index (NBCi), reflective of nocturnal bladder capacity. The records of 100 consecutive men with lower urinary tract symptoms (LUTS), having undergone video-urodynamic studies (VUDS), were prospectively studied. Evaluation included American Urological Association symptom score (AUASS), micturition diary (day, night, and 24-hr voided volume), and VUDS. Voiding diary analysis was carried out as previously described by us, determining the Ni, NBCi, and nocturnal polyuria index (NPi) (nocturnal urine volume/24-hr urine volume). In the case of AUASS question #7 (degree of nocturia), the odds of having a severe AUA question #7 response was found to be 4.09 times higher for patients with NBCi > 2.0 compared with patients whose NBCi was </= 2.0 using logistic regression analysis. In comparing patients with severe nocturia and low NBCi with those having mild nocturia and low NBCi, Ni performed in a fashion superior to NPi in identifying relative nocturnal urine overproduction as the suspected explanation for their nocturia (Ni = 3.42 vs. 1.42, P = 0.0002 cf. Npi = 0.44 vs. 0.27, P = 0.018, Mann-Whitney test, respectively). We suggest a discriminating threshold of NBCi > 2 as highly significant in defining diminished NBC as a factor in the etiology of nocturia. In addition, we propose Ni of 1.5 as a threshold greater than which nocturia may be attributed to nocturnal urine overproduction in excess of maximum bladder capacity. Together, these indices describe in quantitative fashion the relative contributions of nocturnal urine overproduction and diminished NBC in identifying the etiology of nocturia in male patients. Neurourol. Urodynam. 18:559-565, 1999.

Urodynamic findings in Parkinson's disease

Neurological evaluation was performed in 24 men and 5 women with Parkinson's disease who had persistent bladder symptoms. Detrusor hyperreflexia was found in 26 (90 per cent) of the patients. Sporadic involuntary electromyography activity of the external sphincter during involuntary detrusor contractions was encountered in 61 per cent but in none did this cause obstruction. Coordinated striated sphincter relaxation during voluntary detrusor contraction was found in 13 patients (45 per cent). Among 22 men who were in the prostatic disease age group only 4 (18 per cent) had definite prostatic obstruction. Moreover, none of 8 men with persistent symptoms after prostatectomy had evidence of bladder outlet obstruction.

Detrusor-external sphincter dyssynergia in men with multiple sclerosis: an ominous urologic condition

A total of 27 men with multiple sclerosis underwent urodynamic evaluation as part of a prospective study of voiding dysfunction. Of 18 patients with detrusor-external sphincter dyssynergia 9 suffered serious urologic complications, including repeated episodes of urosepsis, vesicoureteral reflux and urolithiasis. None of the 9 patients without dyssynergia suffered any urologic complications. Urologic complications were correlated highly to the presence of detrusor-external sphincter dyssynergia and the severity of multiple sclerosis but not to duration of multiple sclerosis, age of the patient or type of dyssynergia. Although no treatment was without complications it appears that either anticholinergics plus intermittent self-catheterization or condom catheter drainage is superior to an indwelling catheter for initial conservative treatment. External sphincterotomy or urinary diversion may be necessary if conservative therapy fails.

Learned voiding dysfunction (non-neurogenic, neurogenic bladder) among adults

Data concerning learned voiding dysfunction (Hinman syndrome; non-neurogenic, neurogenic bladder) in adults are scarce. The present study was conducted to assess the pre-valence and clinical characteristics of this dysfunction among adults referred for evaluation of lower urinary tract symptoms. Learned voiding dysfunction was suggested by a characteristic clinical history and intermittent "free" uroflow pattern and by the absence of any detectable neurological abnormality or anatomic urethral obstruction. A definitive diagnosis was made by the demonstration of typical external urethral sphincter contractions during micturition by EMG or fluoroscopy. A urodynamic database of 1,015 consecutive adults was reviewed. Twenty-one (2%) patients (age, 24-76 years) met our strict criteria of learned voiding dysfunction. Obstructive symptoms were the most common presenting symptoms, followed by frequency, nocturia, and urgency. Eight (35%) patients had recurrent urinary tract infections, seven of these being women. None of the patients had any clinically significant upper urinary tract damage. First sensation volume was significantly lower in women than in men. Both detrusor pressure at maximum flow and maximum detrusor pressure during voiding were found to be significantly higher in men than in women. Further differentiation between adult women and men failed to reveal any other clinically significant differences. In conclusion, by strict video-urodynamic criteria, 2% of our patients had learned voiding dysfunction. Other patients, with presumed learned voiding dysfunction, who did not undergo video-urodynamics were not included in the present series. Thus, the prevalence of learned voiding dysfunction among adults referred for evaluation of lower urinary tract symptoms is likely to be even higher.

Bladder neck obstruction in women

Bladder neck obstruction in women is rare. The symptoms are confounding and nonspecific. The diagnosis depends on demonstrating poor uroflow, a detrusor contraction of adequate magnitude and duration, and radiographic evidence of obstruction at the vesical neck. We treated successfully 3 women with vesical neck obstruction by transurethral vesical neck incision.

Tissue strength analysis of autologous and cadaveric allografts for the pubovaginal sling

The aim of this study was to compare the mechanical properties of autologous rectus fascia (ARF), two groups of commercially available cadaveric fascia lata commonly used in pubovaginal sling surgery [freeze-dried (FD) and solvent-dehydrated (SD)], and commercially available cadaveric dermal grafts (DG) evaluate differences in tissue strength and stiffness. We prospectively studied the maximum load to failure (MLF) and stiffness in 20 specimens of ARF, 20 specimens of FD, 20 specimens of SD, and 10 specimens of DG. Autologous fascia was obtained from patients undergoing pubovaginal sling operation utilizing rectus fascia. Cadaveric fascia was re-hydrated in saline. All specimens were then tailored into 1 x 1-cm samples and mounted onto the Instron tensiometer. Samples were loaded to failure at a 100% strain rate and force-elongation curves were generated. MLF was defined as the minimum force needed to tear the tissue. Stiffness was determined by the slope of the linear portion of the force/elongation curve between 5 and 15% strain. Statistical analysis was performed using Student's t-test. There is no statistical difference in both MLF and stiffness among ARF, SD, and DG. These data show that MLF and tissue stiffness of SD and DG are comparable to that of ARF. FD has a significantly lower MLF and is significantly less stiff than ARF, SD, and DG. The SD cadaveric fascia lata allograft and the cadaveric dermal allograft may be suitable alternatives to ARF for pubovaginal sling surgery. Neurourol. Urodynam. 18:497-503, 1999.