Biomedical subjects

Andrew J Combs

Publications and source records attributed to Andrew J Combs.

5 recordsLinked to original sources

PubMed2005

Primary bladder neck dysfunction: an overlooked entity in children.

Primary bladder neck dysfunction is a non-neurogenic voiding disorder commonly diagnosed in young and middle age adult men, but frequently overlooked in children. Because these children typically present with lower urinary tract symptoms that also are associated with other more common forms of dysfunctional voiding, the diagnosis may be missed and treated with a variety of empiric modalities that ultimately fail. Although its underlying pathogenesis remains debated, the hallmark of the diagnosis is a failure of the bladder neck to properly open and allow for unimpeded urine flow. Videourodynamic evaluation is the only diagnostic tool that can urodynamically document the obstructive pressure/flow parameters of the condition while simultaneously localizing the functional obstruction to the bladder neck fluoroscopically. This article reviews the clinical and urodynamic findings of this entity in children and adolescents and our experience with a adrenergic antagonists, the current approach in medical therapy.

Adrenergic alpha-Antagonists↗

PubMed2005

Primary bladder neck dysfunction in children and adolescents II: results of treatment with alpha-adrenergic antagonists.

PURPOSE: Little has been reported on the occurrence of primary bladder neck dysfunction (PBND) in the pediatric patient, particularly as it relates to the use of alpha-blocker therapy, the mainstay of medical therapy in adults. Diagnosed on videourodynamics (VUDS), PBND is characterized by the constellation of prolonged opening time, incomplete bladder neck funneling, quiet pelvic floor electromyogram (EMG) during voiding and abnormal pressure flow parameters. We report the VUDS findings in PBND and our experience with alpha-blocker therapy in the pediatric and adolescent population. MATERIALS AND METHODS: A total of 34 symptomatic patients met all VUDS criteria for PBND, and alpha-blocker therapy was initiated in 26. All patients were monitored with serial noninvasive uroflow studies with pelvic floor EMG (uroflow/EMG) before and after initiation of alpha-blocker therapy. Objective clinical response was assessed by measuring average and maximum uroflow rates, post-void residual urine volumes and pelvic floor EMG lag time, a correlate of opening time. RESULTS: A total of 26 patients with PBND (20 males, 6 females) 5.5 to 20 years old at initiation of therapy (mean age 12.8 years) were treated with alpha-blockers. Mean average and maximum uroflow rates improved from 5.5 to 12.6 cc per second and from 10.3 to 19.7 cc per second, respectively, while mean EMG lag time decreased from 24.4 to 5.7 seconds and post-void residual urine volume from 98.9 to 8.9 cc (all p <0.001). Mean followup was 31 months, with all patients reporting significant symptomatic improvement. No patient experienced any major adverse side effects. The 8 patients with PBND who refused alpha-blocker therapy had no improvement symptomatically or urodynamically with time, and those who discontinued therapy had a return to pretreatment values. CONCLUSIONS: PBND is an often overlooked but significant cause of voiding dysfunction in children and adolescents. In our experience alpha-blockers are clinically effective therapy for PBND and have been reasonably well tolerated in our young patients for what may possibly be a lifelong problem.

Adolescent↗

PubMed2005

Primary bladder neck dysfunction in children and adolescents I: pelvic floor electromyography lag time--a new noninvasive method to screen for and monitor therapeutic response.

PURPOSE: One of the key findings for making the diagnosis of primary bladder neck dysfunction (PBND) on videourodynamics (VUDS) is prolongation of the time between the start of a voluntary detrusor contraction and the start of urine flow (opening time). Since normally this dynamic event is immediately preceded by pelvic floor relaxation, we determined if the interval between pelvic floor relaxation on pelvic floor electromyography (EMG) and the start of flow (pelvic floor EMG lag time), approximated opening time. MATERIALS AND METHODS: Opening time measured on VUDS and pelvic floor EMG lag time measured on noninvasive uroflowmetry/EMG were compared in 22 consecutive patients with a mean age of 13.8 years diagnosed with PBND and a control group of 17 normal children. In addition, 19 patients with PBND were placed on alpha-blocker therapy, and pretreatment and on treatment uroflowmetry and pelvic floor EMG lag time values were compared. RESULTS: Mean opening time and mean pelvic floor EMG lag time were statistically indistinguishable from each other in the PBND and normal groups (27.4 vs 23.9 and 1.1 vs 1.3 seconds, respectively, p >0.550), but they differed significantly between the normal and PBND groups (p <0.001). On alpha-blocker therapy a decrease in mean pelvic floor EMG lag time from 24.47 to 6.67 seconds (p <0.001) corresponded with improved flow parameters, while no improvement was noted in untreated patients. CONCLUSIONS: Pelvic floor EMG lag time directly correlates with opening time and, when prolonged and associated with abnormal uroflowmetry, it is highly suggestive of PBND, thereby, justifying more invasive evaluation with VUDS or the initiation of empirical drug therapy. Most importantly, it provides an objective means of monitoring treatment response in a disorder that often has lingering symptoms.

Adolescent↗

PubMed2004

When can persistent hydroureteronephrosis in posterior urethral valve disease be considered residual stretching?

PURPOSE: Persistent hydroureteronephrosis (HUN) is often seen in boys with a history of a posterior urethral valve even years after valve ablation and it is often assumed to represent residual stretching. We determined the association of HUN with urodynamic abnormalities, the effect on HUN of treating these abnormalities and when persistent HUN could be considered residual stretching. MATERIALS AND METHODS: Of 71 patients with a posterior urethral valve evaluated after valve ablation 20 (28.2%) had persistent HUN in a total of 32 renal units (RUs). The degree of HUN was graded as mild, moderate or severe. Videourodynamics were performed in all patients with persistent HUN and abnormal urodynamic findings were aggressively treated. HUN was then reassessed and categorized as resolved, improved or unchanged. RESULTS: Abnormal urodynamic findings, primarily hypocompliance and instability, were noted in all 20 patients with HUN. All patients compliant with treatment showed dramatic improvement or complete resolution of abnormal urodynamic parameters. The 32 RUs with persistent HUN were initially graded as mild (8), moderate (13) and severe (11). HUN resolved in 15 RUs and improved to a lower grade in 11 in 26 of the 27 RUs (96.3%) in the 17 patients compliant with treatment. The 3 boys (5 RUs) who were noncompliant with treatment had neither decreased HUN nor improved urodynamic parameters. The 12 of 27 RUs (44.4%) in the treatment group in which HUN failed to resolve completely had no distal ureteral obstruction or identifiable persistent urodynamic abnormality and, thus, they can be labeled as having residual stretching. CONCLUSIONS: Persistent HUN following valve ablation should not be considered residual dilatation until a thorough urodynamic evaluation has been done and any abnormal parameters are addressed. With correction of these abnormal parameters one can expect significant lessening of HUN and hopefully improved long-term preservation of renal function.

Child↗

PubMed2002

Myogenic failure in posterior urethral valve disease: real or imagined?

PURPOSE: It has been suggested that hypocontractility or myogenic failure develops in older boys with a history of 9 posterior urethral valved as the hyperactive, poorly compliant bladders decompensate with age. Also a much higher prevalence of myogenic failure has been reported than we have observed. We determine the prevalence of myogenic failure in boys with a posterior urethral valve and whether myogenic failure was a consequence of earlier detrusor instability or diminished compliance. MATERIALS AND METHODS: We retrospectively reviewed the urodynamic findings of 51 boys after transurethral ablation of a posterior urethral valve. Group 1 (longitudinal group) consisted of 11 boys 12 to 19 years old who had undergone at least 1 serial urodynamic study before and 1 after age 10 years. Group 2 (younger group) included 33 boys whose urodynamic testing was performed before age 10 years. Group 3 (older group) comprised 7 previously treated boys whose initial urodynamic study was done after age 12 years. RESULTS: Overall, myogenic failure was noted in 3 (all group 1) of 51 (5.9%) patients. Each of the 3 boys initially had a hypocompliant bladder, and myogenic failure developed only after institution of anticholinergic therapy and resolved once anticholinergics were discontinued. An additional 34 boys treated with anticholinergics did not have myogenic failure. No tendency towards myogenic failure or marked increase in bladder capacity for age was noted in the older boys. CONCLUSIONS: In our experience myogenic failure is uncommon and more likely secondary to anticholinergic therapy than a preordained consequence of valve disease. We postulate that our proactive, early aggressive use of urodynamic studies and pharmacotherapy to identify and manage the secondary effects of valve disease reduces the incidence of myogenic failure.

Adolescent↗