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J G Blaivas

Publications and source records attributed to J G Blaivas.

At least 19 recordsLinked to original sources
PubMed1992

The cholinergic and purinergic components of detrusor contractility in a whole rabbit bladder model.

Whole rabbit bladders were suspended in a bath chamber and stimulated with ATP, bethanechol, electrical field stimulation, and bethanechol + ATP. Detrusor pressure and fluid expelled by the bladder were recorded, synchronized, and digitized. Detrusor work and power were calculated with a computer program. Maximum work was 61.4 +/- 28.7, 83.3 +/- 17.0, 85.0 +/- 15.0, 90.8 +/- 13.1 cm. H2O, ml. for ATP, bethanechol, electrical and bethanechol + ATP, respectively. Maximum power generated by ATP was 4.8 +/- 3.0 cm. H2O, ml./sec and was approximately 66% of that generated by bethanechol, and 50% of that generated by electrical stimulation, and bethanechol + ATP. ATP cannot empty the bladder with moderate outlet resistance while bethanechol and electrical stimulation can. Our results suggest that ATP is able to generate detrusor power and achieve work in bladder emptying. However, ATP generated power and work is considerably less than that of electrical stimulation or bethanechol alone. ATP mediated contraction is not inhibited by atropine or tetrodotoxin but is inhibited by P2 purinoceptor desensitization, suggesting a functional role of purine receptors on detrusor smooth muscle. Since ATP generated pressure is more rapid than with bethanechol alone, we support the hypothesis that ATP may be important in the initiation of micturition.

Adenosine Triphosphate↗
PubMed1991

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.

Adolescent↗
PubMed1991

Ileocecocystoplasty for the management of refractory neurogenic bladder: surgical technique and urodynamic findings.

A total of 21 incontinent adults with a neurogenic bladder who were refractory to conservative management underwent a modified technique of ileocecocystoplasty. Followup ranged from 1 to 6 years (mean 3.1 years). To ensure a wide anastomosis the augmentation was accomplished by suturing a detubularized ileocecal patch to a large posterior based bladder flap anchored to the psoas muscles. Postoperatively 20 of 21 patients were continent. The remaining woman was cured after surgical correction of sphincteric incontinence. Mean bladder capacity increased from 185 +/- 17 to 595 +/- 43 ml. (standard error). Mean maximum detrusor pressure decreased from 53 +/- 6.3 to 16 +/- 2.3 cm. water (p less than 0.0001). Followup revealed a persistently large capacity, low pressure reservoir in all patients. No patient required anticholinergic medication. None experienced acid-base imbalance, tumors in the augmented bladder or upper tract deterioration. We conclude that this technique of ileocecocystoplasty is suitable for the management of patients with a refractory neurogenic bladder.

Adult↗
PubMed1991

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.

Aged↗
PubMed1991

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.

Adult↗
PubMed1991

Treatment of female incontinence secondary to urethral damage or loss.

Damage to the urethra may be functional or anatomic. In the former, to some extent, the urethra functions merely as a tube. Anatomic damage ranges from small urethrovaginal fistulas to total loss of the urethra, vesical neck, and trigone. For functional damage, the goal is compression of the proximal urethra, and the author favors a pubovaginal fascial sling, which is described. In the author's view, the best results in anatomic loss are obtained by performing an appropriate anti-incontinence procedure at the time of urethral reconstruction.

Adult↗
PubMed1991

Neurogenic bladder simplified.

Neurogenic bladder dysfunction, if not properly diagnosed and treated, can lead to rapid deterioration of renal function by compromise of the upper urinary tracts. Two major categories of neurogenic bladder (detrusor hyperreflexia areflexia) have been discussed including the pathophysiology of the voiding dysfunction and the typical radiographic findings. Radiologists studying patients with suprasacral cord lesions should be aware of the causes, symptoms, and treatment of autonomic dysreflexia. Although video urodynamics is the state-of-the-art modality for evaluating complex or refractory neurogenic bladder, the practicing radiologist with an understanding of this condition can detect many radiographic changes in the lower urinary tract that suggest neurogenic dysfunction of various types.

Female↗
PubMed1990

Urinary dysfunction in transverse myelitis.

Six men and 2 women with a history of transverse myelitis and persistent lower urinary tract symptoms underwent neurourological evaluation. Of the patients, 4 were neurologically intact, while the remainder had residual neurological deficits. Urodynamic studies revealed detrusor-external sphincter dyssynergia in 6 patients. Two patients had detrusor hyperreflexia, of whom 1 also had an incompetent sphincter. Erectile or ejaculatory dysfunction was reported by 3 men. We conclude that prolonged bladder and sexual dysfunction, caused by spinal cord inflammatory insult, may persist despite a systemic neurological recovery. Therefore, bladder management guided by initial and followup urodynamics is recommended.

Adult↗
PubMed1990

Multichannel urodynamic studies in men with benign prostatic hyperplasia. Indications and interpretation.

Recent studies suggest that clinical "prostatism" encompasses at least four conditions that may be present singly or in combination: prostatic urethral obstruction, impaired detrusor contractility, detrusor instability, and sensory urgency. In addition, primary vesical neck obstruction may be present in the absence of benign prostatic hyperplasia (BPH). Thus, the purpose of diagnostic evaluation in men with BPH is to identify precisely the pathophysiology of the patient's symptoms so that rational therapy can be selected.

Humans↗
PubMed1990

Detrusor-external sphincter dyssynergia.

Detrusor-external sphincter dyssynergia (DESD) is characterized by involuntary contractions of the external urethral sphincter during an involuntary detrusor contraction. It is caused by neurological lesions between the brainstem (pontine micturition centre) and the sacral spinal cord (sacral micturition centre). These include traumatic spinal cord injury, multiple sclerosis, myelodysplasia and other forms of transverse myelitis. There are three main types of DESD. In Type 1 there is a concomitant increase in both detrusor pressure and sphincter EMG activity. At the peak of the detrusor contraction the sphincter suddenly relaxes and unobstructed voiding occurs. Type 2 DESD is characterized by sporadic contractions of the external urethral sphincter throughout the detrusor contraction. In Type 3 DESD there is a crescendo-decrescendo pattern of sphincter contraction which results in urethral obstruction throughout the entire detrusor contraction. In patients with sufficient manual dexterity the most reasonable treatment option is to abolish the involuntary detrusor contractions (to ensure continence) and then to institute intermittent self-catheterization (in order to empty the bladder). The bladder may be paralysed pharmacologically or may be surgically converted to a low pressure urinary reservoir by the technique of augmentation enterocystoplasty. In quadriplegic men, transurethral external sphincterotomy may be performed and the incontinence managed with an external urinary appliance. Without proper treatment over 50% of men with DESD develop serious urological complications within about five years. In women these complications are much less common.

Humans↗
PubMed1989

Vaginal flap urethral reconstruction: an alternative to the bladder flap neourethra.

Vaginal flap urethral reconstruction was done in 10 women who sustained total or partial loss of the urethra, and extensive damage to the vesical neck and trigone due to operative complications. In all patients a neourethra was constructed by rolling a vaginal flap into a tube and covering the anastomosis with a labial pedicle fat pad graft and vaginal flap. Five patients underwent a concomitant pubovaginal sling procedure, 3 had a modified Pereyra operation and 1 had a modified Kelly plication. Postoperatively, 9 of the 10 patients had a satisfactory neourethra but 3 required a generous meatotomy to facilitate micturition. Two patients required temporary intermittent self-catheterization. Of the 10 patients 6 were completely continent after a single reconstruction, which included an anti-incontinence repair. Of the patients with postoperative incontinence 2 subsequently were cured with a pubovaginal sling and 1 had a vesicovaginal fistula that was successfully repaired transvaginally. These results support our contention that a vaginal flap urethral reconstruction combined with an appropriate anti-incontinence operation offers a viable and simple alternative to bladder flap urethral reconstruction.

Adult↗