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Biomedical subjects

G M Ghoniem

Publications and source records attributed to G M Ghoniem.

At least 37 records · Page 2Linked to original sources
PubMed1996

Effects of anesthesia on urodynamic studies in the primate model.

PURPOSE: To elucidate the effect of anesthesia on bladder function and urodynamic studies by performing controlled comparisons of the effects of 2 anesthetics on urodynamics in a primate model. MATERIALS AND METHODS: Cystometrograms were performed in 4 awake adult female Rhesus monkeys (Macaca mulatta) via implantable transducer for continuous monitoring and compared with cystometrograms obtained under anesthetic agents. A total of 183 cystometric studies was performed (48 in the awake group, 74 under ketamine anesthesia and 61 under flurane anesthesia. RESULTS: Maximum detrusor contraction pressure [Pdet(max)] was significantly lower under flurane than under ketamine anesthesia (33.1 +/- 2.5 versus 49.1 +/- 8.1 cm.H2O). In the awake state Pdet(max) (47.7 +/- 25.2 cm.H2O) was equal to that obtained under ketamine anesthesia. Cystometric bladder capacity was significantly larger under flurane (101.5 +/- 81.8 ml.) than under ketamine (70.3 +/- 56.1 ml.) anesthesia. It was only (32.9 +/- 15.9 ml.) in the awake state. Cystometric bladder capacity under both anesthetics was larger than the mean voided volume (43.3 +/- 6.3 ml.), but was comparable to the largest voided volume (102.3 +/- 31 ml.). Cystometric reflex contractions with bladder filling occurred more frequently with ketamine (96%) than with flurane anesthesia (66%). CONCLUSIONS: These findings show that anesthesia has profound effects on the bladder, and careful interpretation of urodynamic data is suggested. These findings also suggest that ketamine is a suitable anesthetic for urodynamic studies in the subhuman primate.

Anesthesia, General↗
PubMed1996

Modified rectus fascial suburethral sling.

Pubovaginal slings are being used more frequently for complicated stress urinary incontinence (SUI) secondary to impairment of the proximal sphincteric mechanism. The excellent long-term results of the sling surgery expands its role in genuine stress incontinence, especially high-risk groups. The modification described herein simplifies the surgery and avoids many of its potential complications, meanwhile maintains a high success rate.

Fasciotomy↗
PubMed1996

Effect of transvaginal stimulation in the treatment of detrusor instability.

INTRODUCTION: Early research on implantable electrodes for transvaginal stimulation had high rates of complications and mechanical failures. Today's nonimplantable devices are safe for short-term or long-term use. This study evaluated an intermittent short-term transvaginal stimulation program for treatment of bladder overactivity. METHODS: Fifteen women who ranged in age from 22 to 96 years and had bladder instability were enrolled into this noncontrolled, open, clinical evaluation program. Six to 10 biweekly office sessions were followed by use of a home unit twice daily for approximately 6 weeks. RESULTS: Results were based on patients' voiding diaries. All 15 completed the study, and 73% were satisfied with the results. On pretrial urodynamic examination nine patients had sensory urgency, and six patients had involuntary contractions. All tolerated therapy without side effects. Two women had slight vaginal discomfort because of vaginal narrowing. Urinary frequency, urgency, and nocturia were significantly decreased. Seven women reported 75% or more improvement; four women reported 50% to 75% improvement. Three women required a second office treatment series. DISCUSSION: The results of this study support findings of previous researchers, although the follow-up time frame of the study was short. Most of these patients (N = 11 of 15) wished to continue transvaginal stimulation. When three women discontinued home treatments, symptoms recurred in 1 to 3 months. The exact cause is unclear, but scar tissue as a result of previous pelvic operations may have contributed to the problem. The second course of treatment had positive results. Intermittent therapy in these cases is recommended. Transvaginal stimulation should be considered for treatment for urinary incontinence because the device is easily used and adjusted by the patient, patients may be very compliant, and results are satisfactory and at least similar to those attained with drug therapy.

Adult↗
PubMed1995

Irritable bladder syndrome in an animal model: a continuous monitoring study.

Irritable bladder syndrome (IBS) was induced in four female African green monkeys (Cercopithecus aethiops) by the use of intravesical instillation of acetone. The animals were housed in a modified metabolic cage for continuous micturition monitoring, and two uroflowmeters connected to a remote PC monitored the frequency, voided volumes, and peak flows. Before and after, urea absorption studies and urodynamics were obtained for each animal. Urea absorption increased significantly after acetone instillation and returned to baseline after 4 weeks (26 to 66 to 32%). Intravesical acetone instillation produced marked effects on bladder physiology in the first week. Bladder compliance dropped from a baseline of 10.47 to 0.58 ml/cm H2O. The voiding pattern changed from a normal pattern with a mean voided volume of 17.58 ml into marked increase in frequency and dribbling pattern with few voids (mean = 5.03 ml). Systematic behavioral observations were carried out for 4 hours per day utilizing an observation program on a laptop computer. Activity patterns, attention, sterotypic behaviors, and self-directed activities were recorded for each monkey. The animals demonstrated decreased frequency of activity and increased frequency in self-directed activities (groom, scratch), behaviors consistent with an animal experiencing pain or discomfort. The findings suggested that IBS induction in monkeys is feasible and produces a clinical picture similar to interstitial cystitis in humans. It offers a suitable animal model to enhance the understanding of voiding dysfunction with its neural pathways and to test the different therapeutic modalities to control IBS.

Acetone↗
PubMed1995

Modified pubovaginal sling and Martius graft for repair of the recurrent vesicovaginal fistula involving the internal urinary sphincter.

A modified Martius graft interposition flap was used in conjunction with the modified pubovaginal sling bladder suspension to treat a recurrent vesicovaginal fistula involving the proximal urethra and bladder neck. The patient recovered with no incontinence, voiding dysfunction or dyspareunia. Incontinence should be anticipated with vesicovaginal fistulas involving the internal sphincter and repair should be tailored to include an organic suburethral sling.

Adult↗
PubMed1995

Simplified surgical approach to bladder outlet obstruction following pubovaginal sling.

We report a new technique of vaginal patch interposition to relieve bladder outlet obstruction after a suburethral sling procedure when the obstruction is caused by over correction of the urethrovesical angle. In this technique the sling is incised longitudinally in the midline and dissected laterally. A vaginal patch is obtained from the vaginal mucosa, then interposed and sutured between the 2 cut edges of the sling. This method is characterized by simplicity and low morbidity, while preserving the integrity of the suburethral sling to maintain continence.

Aged↗
PubMed1995

Effect of mucosal removal on the response of the feline bladder to pharmacological stimulation.

The urothelium plays an important role in the maintenance of normal bladder function. It provides a nonpermeable barrier to the contents of urine. The urothelium is directly involved in the transduction of both intravesical pressure and intravesical volume information to the afferent nerve fibers located within the lamina propria area. A third function may be to modulate bladder contractile function through local secretion of bioactive substances into the muscularis layers adjacent to the urothelium. To test this last hypothesis, the following experiments were performed: Strips of female cat bladders were isolated from the bladder body, base and urethra. The mucosa of alternate adjacent strips was removed, and the contractile response to field stimulation (FS), bethanechol (body), phenylephrine (base, urethra) and KCI was determined. For the bladder body, the strips without mucosa responded to FS, bethanechol, adenosine triphosphate (ATP) and KCI significantly greater than the strips with mucosa intact. For the bladder base and urethra, the contractile responses to FS, KCI and phenylephrine were significantly greater for the strips with mucosa removed as compared with the strips with mucosa intact. For the urethra and bladder base, FS in the presence of phenylephrine produced a relaxation. For the bladder base, the degree of FS relaxation of the isolated strips with mucosa removed was significantly greater than the strips with mucosa intact. For the urethra, FS relaxation was similar for the two groups. In conclusion, removal of the urothelium significantly and substantially increased the contractile response to FS, KCI, bethanechol and phenylephrine. Field stimulation relaxation in the bladder base was also enhanced. Thus in the cat, the mucosa has a significant inhibitory effect on the contractile response of the bladder to stimulation. The mechanism of this activity is not clear at the present time but will be the subject of further study.

Adenosine Triphosphate↗
PubMed1995

Dormant microbes in interstitial cystitis.

Interstitial cystitis (IC) is an inflammatory disease of the urinary bladder that has no known etiology. A microbial association with this disease has not been supported since routine cultures of urine from IC patients are usually negative. However, we have demonstrated the presence of bacterial 16S rRNA genes in bladder biopsies from 29% of patients with IC, but not from control patients with other urological diseases. The ability to identify the presence of bacterial DNA in these patients was accomplished using a sensitive and specific nested PCR method capable of amplifying 16S rRNA genes from a wide variety of bacterial genera. Cloning and sequencing of 16S rRNA gene fragments amplified from bladder tissue of IC patients showed that these genes were derived from genera representing Gram-negative bacteria. In addition to the molecular data, a novel finding of 0.22 micron. filterable forms has been isolated in culture from the biopsy tissue of 14 of 14 IC patients and from 1 of 15 controls. The forms contain nucleic acids and resemble cell wall-deficient bacteria in gross morphology; however, their swirled myelin-like ultrastructure is unusual and suggests a heretofore unclassified microbe. These results demonstrate for the first time an association of Gram-negative bacterial DNA and filterable forms with affected bladder tissue from patients with IC.

Bacteria↗
PubMed1994

Animal research.

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Animals↗
PubMed1994

Dollars and sense: considerations for experimental model design.

Our recent review indicates that numerous factors are involved in selecting an animal model for the study of human disease processes. These include: anatomic, neurologic, physiologic, and pathologic parameters, concept of discrimination, volume of knowledge available, and costs. Regarding costs, data was collected from twelve medical research institutions in relation to the eight animals selected for comparative cost analysis: rhesus monkey, cynomolgus monkey, Sprague-Dawley (S.D.) rat, dog (mongrel), cat (mixed breed), swine (piglet), guinea pig, and rabbit. Biologically, the choices are vast and depend upon the investigator and the experimental design. Economically, pricing is a substantial constraint that varies widely and is institutionally dependent. Furthermore, within the same institution, costs differ according to the source of funding (e.g., private, federal, state, or institutional). However, if the investigator carefully considers these biologic and economic factors, it is possible to select an appropriate animal model.

Animals↗
PubMed1994

Tulane experience with management of urinary incontinence after placement of an artificial urinary sphincter.

Persistent urinary incontinence following placement of an artificial urinary sphincter (AUS) presents a challenging diagnostic problem. This report reviews 30 cases (27 males and 3 females) involving urinary incontinence following AUS placement. The mean age of the patients was 64.4 years (range, 10-79 years). Physical examination demonstrated evidence or suspicion of infection or erosion in 7 patients, and subsequent cystoscopic examination revealed erosion caused by the cuff in 6 of these 7 cases. The remaining 23 patients were evaluated by videofluorourodynamics (VFUD) to ascertain the cause of incontinence. VFUD demonstrated detrusor instability in 9 patients (39%), low detrusor compliance in 3 patients (13%), and poor detrusor contractility in 1 patient (4.4%). Bladder-outlet obstruction was diagnosed in 2 patients (8.8%)-1 with bladder-neck contracture and 1 with ureteral stricture. Altogether, 2 (8.8%) cases of tissue atrophy were diagnosed with low urethral closing pressure at the cuff. In all, 1 patient (4.4%) was diagnosed as having a vesicovaginal fistula, 1 (4.4%) had a tubing kink, and 4 (17%) had leaking devices diagnosed during VFUD by cycling of the device. Of the 23 patients, 21 (91%) demonstrably improve or became fully continent after appropriate treatment had been initiated. A review of this study suggests that the majority of incontinent patients after AUS implantation can be managed successfully, provided that a systematic diagnostic approach is followed and appropriate treatment is initiated.

Algorithms↗
PubMed1994

The value of the vaginal pack test in large cystoceles.

To detect possible stress urinary incontinence associated with but masked by large cystoceles protruding through the vaginal orifice, a vaginal pack test was done in conjunction with video fluoro-urodynamic studies. Sixteen female patients with large cystoceles did not demonstrate stress urinary incontinence on clinical examination and were included in this study. Additionally, 10 healthy female volunteers underwent the same test to study the effect of a vaginal pack on urethral dynamics. The vaginal pack revealed the presence of stress urinary incontinence in 11 patients (69%): 3 (19%) with type II (vesicourethral hypermobility) and 8 (50%) with type III (internal sphincteric deficiency). After insertion of the vaginal pack, urodynamic studies showed that the closing proximal urethral pressure in patients with stress urinary incontinence was significantly lower than in continent patients (p < 0.05). No significant change in urethral pressures was noted in volunteer subjects after vaginal pack insertion. Fluoroscopy showed kinking of the posterior urethra and enlargement of the most dependent portion of the cystocele, that is the lower half of the hourglass image. Our study suggests that the mechanisms of continence in these patients are multifactorial, including urethral kinking, urethral compression and pressure dissipation. The vaginal pack test is easy to perform, increases visualization of the vesicourethral unit when used with fluoroscopy, and can aid in the selection of patients who would benefit from anti-incontinence surgery and/or cystocele repair.

Adult↗
PubMed1994

Ilioinguinal nerve entrapment following needle bladder suspension procedures.

Ilioinguinal nerve entrapment is a documented complication of inguinal herniorrhaphy, inguinal lymph node dissection, and appendectomy. This article reports two clinical histories to illustrate the diagnosis and management, and outlines prevention of ilioinguinal nerve entrapment as a complication of needle suspension procedures for stress urinary incontinence.

Adult↗
PubMed1994

Bladder neck wrap: a modified fascial sling in treatment of incontinence in myelomeningocele patients.

In a large percentage of myelomeningocele patients the bladder neck and posterior urethra are widely open. Pubovaginal or puboprostatic sling has been proposed to achieve continence. Herein, a further modification of the fascial sling is presented. By wrapping the sling around the bladder neck more coaptation is achieved. Four patients underwent this modification and all of them are currently continent and on clean intermittent catheterization.

Child↗
PubMed1993

Clinical experience with multiagent intravesical therapy in interstitial cystitis patients unresponsive to single-agent therapy.

A total of 25 patients with the diagnosis of interstitial cystitis (IC) were involved in this study. All patients had been previously diagnosed with interstitial cystitis and had received treatment with single intravesical agents. Patients were divided into two groups according to their bladder capacity. The bladder capacity was > 350 ml in group I patients and < 350 ml in group II patients. For our study, dimethylsulfoxide (DMSO), methylprednisolone, and heparin sulfate were given every week for a total of 6 weeks. When symptoms recurred, supportive oral pharmacotherapy consisting of anticholinergics and/or tricyclic antidepressants was given. Under anesthesia, patients in group I showed a 99% increase in their bladder capacity; whereas those in group II showed an increase of only 19%. Cystoscopically, Hunner's ulcers were present in 60% of the group II patients but were seen in only 5% of the group I patients. Histopathological examination showed that the inflammatory changes were more frequent and severe in group II than in group I. Mast-cell hyperplasia was present in 100% of the patients in group II, versus only 61% of those in group I. A total of 23 patients (92%) achieved an initial remission averaging 8.1 months. In all, 9 patients (35%) had 1 or more relapses, and all achieved a subsequent remission averaging 8 months. By this combined multiagent approach, the majority of patients with IC obtained relief from their incapacitating symptoms and were socially rehabilitated.

Administration, Intravesical↗