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S V Yalla

Publications and source records attributed to S V Yalla.

At least 19 recordsLinked to original sources
PubMed1995

Correlation between micturitional urethral pressure profile and pressure-flow criteria in bladder outlet obstruction.

PURPOSE: We correlate micturitional urethral pressure profilometry with pressure-flow diagnoses of outlet obstruction. MATERIALS AND METHODS: Urodynamic evaluation was done of 86 consecutive men with voiding symptoms. Obstruction criteria were a micturitional urethral pressure profile (MUPP) gradient greater than 5 cm. water, Schäfer's linear passive urethral resistance relation (PURR) greater than grade 1 and Abrams-Griffiths nomogram. RESULTS: Interpretable results were completed in 99% of the patients undergoing MUPP and 60% undergoing pressure-flow studies (p < 0.00001). MUPP diagnosis agreed with PURR (p = 0.0015) and Abrams-Griffiths nomogram results (p = 0.00004). MUPP gradients correlated well with PURR (r = 0.70, p < 0.00001). Using optimum cutoff values (11 cm. water), the sensitivity of MUPP was 83%, specificity 82% and positive predictive value 94%. CONCLUSIONS: MUPP correlates well with and yields interpretable results more often than pressure-flow studies.

Aged↗
PubMed1995

Implications of the most bothersome prostatism symptom for clinical care and outcomes research.

OBJECTIVES: Because treatment of benign prostatic hyperplasia (BPH) is based largely on patients' symptoms, understanding and measuring the impact of these symptoms from the patient's perspective is critically important for clinical care. Such knowledge also is crucial for comparing patient-weighted outcomes because the increasing array of medical and surgical BPH treatments differ in their impact on specific symptoms. Our purpose was to determine the most bothersome symptom in older men seeking evaluation for symptomatic BPH and to examine whether age, comorbidity, or urodynamic evidence of prostatic obstruction were important covariates. DESIGN: Prospective evaluation of a consecutive series. SETTING: Veterans Affairs urology clinic. PARTICIPANTS: 115 men (age 69 +/- 6 years) presenting for initial evaluation of prostatism. MEASUREMENTS: Scores on standard symptom index and patients' reports of the most bothersome symptom. Bladder outlet obstruction was assessed by multichannel videourodynamic evaluation. RESULTS: An "irritative" symptom (frequency, urgency, or nocturia) was cited as most bothersome significantly more often than an "obstructive" symptom (weak stream, hesitancy, etc.) (53 vs. 35%, P < .05); older men were significantly more likely to name an irritative symptom as most bothersome (chi 2 for trend = 6.63, P < .025). Even among men with prostate obstruction, most cited an irritative symptom as the most bothersome, regardless of the severity of obstruction. These associations were not confounded by comorbid conditions or medications that independently may cause symptoms. CONCLUSIONS: Because irritative symptoms are most bothersome, have a diverse differential diagnosis, and do not respond as well to BPH treatment, neither providers nor researchers should rely solely on global assessments of symptom severity and bother in assessing men with voiding symptoms. Additional focus on individual symptom impact and etiology is needed, especially in older men.

Age Factors↗
PubMed1995

Correlation of American Urological Association symptom index with obstructive and nonobstructive prostatism.

The precise role of the American Urological Association (AUA) symptom index in the management of benign prostatic hyperplasia (BPH) is not well established. The AUA symptom index has been recommended only for quantifying the symptoms of BPH but not for its diagnosis. However, to our knowledge the ability to discriminate obstructive from nonobstructive BPH using the AUA symptom index has never been investigated. To establish the relationship between the AUA symptom index and prostatic obstruction 125 men (mean age 67.7 +/- 8.4 years) with voiding dysfunction presumably related to BPH were analyzed. Patients were given the AUA symptom questionnaire, following which video urodynamic studies were done, including micturitional urethral pressure profilometry for specifically diagnosing outlet obstruction. The patients were divided into 2 groups: group 1-78 with primary BPH dysfunction and group 2-47 with prostatism of ambiguous etiology. The mean AUA symptom index in group 1 (15.5 +/- 7.1) was not statistically different from that in group 2 (14.8 +/- 7.9). In both groups the mean AUA symptom index in the patients with obstruction (15.3 +/- 7.2 for group 1 and 13.9 +/- 7.9 for group 2) was not statistically different from that in the nonobstructed group (17.0 +/- 5.4 and 16.1 +/- 7.9, respectively). Of the severely symptomatic patients 22% did not have obstruction whereas all mildly symptomatic patients did. No significant correlations were found between the severity of obstruction and the AUA symptom index in either group. These observations indicate that the AUA symptom index cannot discriminate obstructed from nonobstructed BPH cases, not all severely symptomatic BPH patients will have outlet obstruction, a significant proportion of mildly symptomatic BPH patients can have outlet obstruction and voiding dysfunctions in elderly men, regardless of the etiology, produce similar symptoms.

Aged↗
PubMed1995

Continuous occlusion test to determine detrusor contractile performance.

PURPOSE: A study was conducted to determine the merits of the continuous occlusion test as a method of detrusor contractility assessment by comparing it with other stop tests and with contractility derived from pressure-flow analysis. MATERIALS AND METHODS: The continuous occlusion test was performed in elderly men by occluding the bladder outlet before the onset of a detrusor contraction and it was repeated to assess reproducibility. The magnitude of the isovolumetric contraction, maximum slope of the detrusor contraction, and duration of detrusor activation were determined. Voluntary and mechanical stop tests were performed during the mid voiding phase. Continuous occlusion test parameters were compared with the pressure-flow contractility parameters. RESULTS: The continuous occlusion test was evaluated in 159 patients. The maximum isovolumetric contraction pressure of the continuous occlusion test was significantly higher than that of the voluntary stop test (49 patients). Continuous occlusion test contractility parameters were reproducible. The maximum isovolumetric contraction pressure and the maximum slope of the detrusor contraction of the continuous occlusion test significantly correlated with the estimated maximum isovolumetric contraction pressure and estimated velocity of shortening (derived from pressure-flow), respectively (r = 0.79, p < 0.0001 and r = 0.385, p = 0.016, 39 patients). The watts factor was well correlated with maximum isovolumetric contraction pressure (r = 0.75, 39 patients). CONCLUSIONS: Our study suggests that the continuous occlusion test can be used as an effective alternative method of assessing detrusor contractility.

Adult↗
PubMed1991

Viscoelastic properties of the contracting detrusor. II. Experimental approach.

Mechanical properties of detrusor muscle were studied with small-amplitude oscillatory volume perturbations in isometrically contracting bladders of anesthetized dogs. Contractions were studied at oscillatory frequencies (f) of 2 and 4 Hz and at bladder volumes (Vbl) ranging from 30 to 110 ml. The magnitude of bladder hydrodynamic stiffness (magnitude of G) increased linearly with mean detrusor pressure (Pdet) while the phase angle remained relatively constant during contraction. The slope (mG) of magnitude of G-Pdet relations had a positive dependence on f and a negative dependence on Vbl. Analysis of oscillatory data, described in the companion paper, was performed using incremental lumped-parameter models consisting of a spring with incremental constant (S = dF/dL), a viscous element with incremental viscosity (b = dF/du), and a mass (m). Only the model where elastic and viscous elements were placed in series with each other and in parallel with mass was compatible with the experimental data. Both S and b increased linearly with effective force (F), defined as Pdet times the cross-sectional area of the intravesical cavity. Slopes of the S-F and b-F relationships (ms and mb) were independent of Vbl and varied only slightly with f. The importance of this finding stems from recognizing that ms and mb correspond to the exponential coefficients of nonlinear series elastic and internal viscosity elements. These parameters, when normalized by resting muscle length, represent fundamental muscle properties independent of muscle cross-sectional area, stretch, or level of activation and compare well with parameters derived from other muscle systems using techniques such as quick releases and isotonic contractions.

Animals↗
PubMed1991

Disorders of bladder function in spinal cord disease.

Successful management of bladder function mandates a thorough knowledge of the neuroanatomy and physiology of micturition. Accurate urodynamic diagnosis of the exact vesicourethral dysfunction is a key to successful management. The primary concern for the urologist is preservation of renal function, taking into account the social needs of the patient.

Humans↗
PubMed1990

Assessment of urinary dysfunction in the elderly.

This article discusses the significance of specific signs and symptoms in the history and physical examination as they apply to the lower urinary tract in the geriatric population. The relevant use of urodynamics, cystoscopy, and other innovative techniques that aid in the assessment of urinary dysfunction will be covered.

Aged↗
PubMed1989

The pathophysiology of urinary incontinence among institutionalized elderly persons.

Although 1 million institutionalized elderly persons have urinary incontinence, little is known about the causes of this problem. We conducted clinical and physiologic studies to determine the causes of established incontinence in a representative sample of 605 institutionalized elderly persons (mean age, 89 years), of whom 40 percent were chronically incontinent of urine. Detailed urodynamic studies in 94 of the 245 incontinent patients (77 women and 17 men; 38 percent) showed that detrusor overactivity was the predominant cause in 61 percent, with concomitant impaired detrusor contractility present in half these patients. Other causes among women were stress incontinence (21 percent), underactive detrusor (8 percent), and outlet obstruction (4 percent). Among the relatively few men in this sample, outlet obstruction accounted for 29 percent of the cases. In 35 percent of the patients, at least two coexisting probable causes of incontinence were identified. Diagnoses among patients with impaired mobility or mentation differed little from those in unimpaired patients. We conclude that the pathophysiology of incontinence in this population is complex; that detrusor hyperreflexia with normal contractility ("uninhibited bladder") accounts for the minority of cases (29 percent), even among patients with dementia; and that the causes of incontinence are as diverse in severely impaired elderly persons as in those who are unimpaired.

Aged↗
PubMed1987

Detrusor hyperactivity with impaired contractile function. An unrecognized but common cause of incontinence in elderly patients.

Little is known about the causes of urinary incontinence in institutionalized elderly people, despite the fact that $8 billion is annually devoted to diapering those afflicted. We have identified a specific physiological abnormality--detrusor hyperactivity with impaired contractile function (DHIC)--that, although previously unrecognized, is the second most common (33%) cause of incontinence in this setting. Detrusor hyperactivity with impaired contractile function is a distinct physiological subset of detrusor hyperreflexia and presents with a seemingly paradoxical set of findings: the bladder is overactive but empties ineffectively. This imparied emptying is due to diminished detrusor contractile function and is associated with bladder trabeculation, a slow velocity of bladder contraction, little detrusor reserve power, and a significant amount of residual urine. Aside from its high prevalence, the importance of DHIC is that it may present as urinary retention, may closely mimic prostatic outlet obstruction, may explain why past therapeutic trials for detrusor hyperreflexia have failed, and may necessitate a change in the current nosology of bladder dysfunction. Furthermore, DHIC may represent a more advanced stage in the natural history of detrusor hyperreflexia, a stage characterized by deterioration of detrusor contractile efficiency. Thus, this previously unrecognized cause of incontinence in the elderly is common and raises several important issues.

Aged↗
PubMed1986

Refractoriness of urethral striated sphincter during voiding: studies with afferent pudendal reflex arc stimulation in male subjects.

To assess the excitability of the striated sphincter under normal and abnormal conditions, electrostimulation of the periurethral striated sphincter via the dorsal nerve of the penis was done with the patient at rest and during voiding. Monitoring of simultaneous intravesical and intramembranous urethral pressures, and electromyographic responses of the striated sphincter was performed under fluoroscopic guidance in 14 male subjects. The urethral striated sphincter attained a state of relative refractoriness during detrusor contraction (voiding phase) and greater amounts of afferent stimulation were required to elicit sphincter contractile activity compared to the amounts required during resting states. Under conditions of a hyperactive detrusor with synergic voiding, the amounts of stimulation required to elicit striated sphincter responses were higher than those required in normal subjects. On the other hand, under conditions of striated sphincter dyssynergia, minute amounts of afferent stimulation were enough to produce sphincter contraction during voiding.

Electric Stimulation↗
PubMed1985

Elastic jump in male urethra during voiding: clinical observations in male subjects and experimental studies in dogs.

A physical phenomenon known as elastic jump occurs downstream of an elastic constriction applied to a collapsible tube. This flow anomaly is analogous to the hydraulic jump that occurs in surface flows. Some investigators have predicted that an elastic jump could occur in the male urethra (during voiding) in the cavernous segment between constrictions at the membranous and meatal regions. To identify and understand this flow anomaly, and to obtain clinical correlations in human male subjects we have attempted several radiological and urodynamic studies in normal and abnormal subjects. The studies were retrograde urethrography, voiding cystourethrography, static pressure recordings during voiding and uroflowmetry. Retrograde urethrography was believed to delineate accurately the anatomy of the bulbous urethra. Voiding cystourethrography showed the geometry of the functional bulb. Our observations in 43 male subjects suggest that the site and degree of elastic jump depend on the severity of bladder neck or prostatic obstruction, magnitude of detrusor pressure (energy) during voiding, degree of distal constriction and position in which the subject voids. The animal studies (23 dogs) confirmed our clinical urodynamic impression.

Adult↗
PubMed1984

Vesicourethral dysfunction following pelvic visceral ablative surgery.

Management of vesicourethral dysfunction after a major extirpative pelvic visceral operation could be complex and difficult owing to the variety of partial and complete functional and anatomical derangements produced by the primary operation. We report our experience with 22 patients who suffered various types of vesicourethral dysfunctions after extirpative pelvic visceral surgery, 5 of whom had preoperative studies. The surgical procedures were abdominoperineal resection in 9 patients, proctocolectomy in 3, anterior resection of the rectum in 2 and radical hysterectomy in 8. All 22 patients underwent urodynamic evaluations. The abnormalities noted on the preoperative urodynamic evaluations in patients about to undergo extirpative pelvic visceral surgery suggest the need for routine preoperative assessment of the lower urinary tract for an accurate understanding of the postoperative changes.

Autonomic Nervous System↗
PubMed1982

Detrusor urethral sphincter dyssynergia: micturitional vesicourethral pressure profile patterns.

Vesicourethral static pressure recordings were attempted in patients with detrusor urethral sphincter dyssynergia. The technique consisted of recording vesicourethral pressures at successive points, commencing in the lower segment of the bladder during micturition. A small catheter with side holes was used for this purpose and static (lateral) pressure profile recordings were attempted during voiding. Successful static pressure recordings were obtained only in those patients who could expel urine as uninterrupted stream. Patients who could not void or those who could void only with interrupted stream have demonstrated profile patterns that required careful interpretation. The accuracy of urodynamic interpretation also depended upon careful clinical evaluation and awareness of the built-in artifacts of the technique.

Female↗