Biomedical subjects

M Bidair

Publications and source records attributed to M Bidair.

9 recordsLinked to original sources

PubMed2000

Ureteral dilation using a tapered dilator: a cost-effective approach.

BACKGROUND AND PURPOSE: The 6/12 AQ hydrophilically coated tapered dilator is a newly developed device for ureteral dilation prior to rigid and flexible ureteroscopy. PATIENTS AND METHODS: To evaluate the efficacy, safety, and cost-effectiveness of this device, it was used to gain ureteral access in 80 consecutive patients undergoing ureteroscopy for diagnostic purposes, stone treatment, or stricture dilation. RESULTS: In all 80 cases, the ureteral orifice and intramural ureter were dilated successfully. One complication occurred: an embedded stone was extruded through the ureteral wall. Each dilation procedure using the 6/12 AQ tapered dilator costs 20% of a balloon dilation, a saving of approximately $764 per dilation. CONCLUSION: Ureteral dilation with the 6/12 AQ tapered dilator is a safe, effective, and inexpensive alternative to traditional dilation techniques.

Constriction, Pathologic↗

PubMed1998

The role of urinary potassium in the pathogenesis and diagnosis of interstitial cystitis.

PURPOSE: We determined whether intravesical potassium absorption in normal bladders correlates with increased sensory urgency, and corroborated the hypothesis that mucus is important in the regulation of epithelial permeability. We compared sensory nerve provocative ability of sodium versus potassium, and determined whether intravesical potassium sensitivity discriminates patients with interstitial cystitis from normal subjects and those with other sensory disorders of the bladder. MATERIALS AND METHODS: A total of 231 patients with interstitial cystitis and 41 normal subjects underwent intravesical challenge with 40 ml. water and then 40 ml. of 40 mEq./100 ml. potassium chloride. Subjective responses of urgency or pain stimulation were recorded on a scale of 0 to 5. In 19 normal subjects potassium absorption was measured at baseline, after injury of the bladder mucus with protamine, after heparin treatment to reverse mucus damage and then for a final time. These subjects simultaneously recorded the symptoms of sensory urgency and pain at baseline, after protamine and after heparin. Another group of normal volunteers underwent a challenge with sodium versus potassium to determine which cation was more provocative. Patients with bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH), detrusor instability, and acute and chronic urinary tract infection but no current infection were also evaluated for potassium sensitivity. RESULTS: Neither normal subjects nor patients with interstitial cystitis reacted to water administered intravesically. There was marked sensitivity to intravesical potassium in 75% of patients with interstitial cystitis versus 4% of controls (p <0.01). Only 1 patient with BPH responded to potassium and none of the 5 with chronic urinary tract infection responded. All 4 patients (100%) with a current acute urinary tract infection reacted positively to the potassium challenge. Of 16 patients with detrusor instability 25% responded. Normal subjects had minimal sensitivity to potassium before (11%) and markedly increased sensitivity after (79%) protamine treatment, and these symptoms were reversed by heparin in 42%. Potassium absorption directly correlated with symptoms (0.4, 3.0 and 1.3 mEq. before and after protamine, and after heparin reversal, respectively). In regard to sodium versus potassium provocation, potassium was far more provocative for causing urgency after protamine (10 versus 90%). Neither group underwent provocation before protamine. CONCLUSIONS: Chronic diffusion of urinary potassium into the bladder interstitium may induce sensory symptoms, damage tissue and be a major toxic factor in the pathogenesis of interstitial cystitis. Intravesical potassium sensitivity is a reliable method for detecting abnormal epithelial permeability. It discriminates between patients with interstitial cystitis and normal subjects with intact epithelial function, and it is a useful diagnostic test for interstitial cystitis. Potassium sensitivity correlates with increased potassium absorption in normal subjects, and potassium is far more provocative than sodium. Potassium sensitivity is also present in acute urinary tract infection and occasionally detrusor instability but not in BPH or chronic urinary tract infections.

Adult↗

PubMed1996

Cryoablation for carcinoma of the prostate.

Percutaneous transperineal cryoablation of the prostate is now available in the armamentarium for treatment of prostate cancer. Technical advances in real-time transrectal imaging of the prostate and improvements in cryosurgical equipment have brought this modality into the limelight of available prostate cancer management. Cryosurgery can be offered to many patients with prostate cancer. However, the main indications for its use include primary treatment for localized disease, salvage therapy after failure of traditional methods, and relief of local symptoms. A historical background, description of the technique, and clinical experience at several medical centers including the University of California San Diego, Allegheny General Hospital, University of Texas M.D. Anderson Cancer Center, and Crittenton Hospital, are presented.

Biopsy↗

PubMed1995

Continuous versus intermittent bladder irrigation of amphotericin B for the treatment of candiduria.

PURPOSE: The efficacy of continuous versus intermittent bladder irrigation with amphotericin B in the treatment of candiduria was compared. MATERIALS AND METHODS: A prospective, randomized and comparative pilot study was done on 20 patients. Continuous bladder irrigation with 50 mg./l. amphotericin B infused during 24 hours for 2 days was compared to 3 intermittent bladder irrigations of 10 mg./100 ml. amphotericin B in 1 day. Urine cultures were obtained 72 hours after treatment. RESULTS: The organism was eradicated in 8 patients (80%) who received continuous irrigation and 3 (30%) who received intermittent irrigation (p = 0.035). CONCLUSIONS: Continuous amphotericin B bladder irrigation was superior in terms of efficacy, ease of administration and patient comfort.

Aged↗

PubMed1995

Primary yolk sac tumor of the prostate in a patient with Klinefelter's syndrome.

Primary yolk sac (endodermal sinus) tumor of the prostate is extremely rare with only 2 cases reported in the literature. We describe a case of primary yolk sac tumor of the prostate in a man with Klinefelter's syndrome. Treatment included 4 courses of combination chemotherapy followed by retroperitoneal lymph node dissection, cystoprostatectomy and ileal conduit urinary diversion. We review the association of Klinefelter's syndrome with extragonadal germ cell tumor along with the management of this rare disease.

Adult↗

PubMed1994

Abnormal sensitivity to intravesical potassium in interstitial cystitis and radiation cystitis.

The urgency-frequency syndrome (UFS) (non-bacterial cystitis, interstitial cystitis) may well represent a heterogenous group with several etiologies. This study was based on the hypothesis that one subset of UFS patients has a leaky (to solutes) epithelium and cations such as potassium could thereby diffuse subepithelially and provoke symptoms. It was also hypothesized that normal impermeable transitional epithelium would not allow cations to diffuse across the cells during the K+ provocation test and no symptoms would be experienced. If the epithelium was permeable ("leaky"), diffusion would occur and provoke symptoms. Water or 0.4 M KCl was placed intravesically into normal volunteers and interstitial cystitis (IC) patients. Water did not provoke symptoms in either group but KCl provoked 4.5% of normals and 70% of IC patients. Differences were significant (P < 0.0001). This test provides a valuable diagnostic tool for UFS and a valuable research tool to separate epithelial permeability problems from other subsets of patients. A third group, consisting of 11 IC patients in remission on heparinoid therapy, was also tested and only 18% were provoked by KCl. Four patients with radiation cystitis were also examined and all four (100%) were provoked by the potassium.

Administration, Intravesical↗

PubMed1993

Magnetic stimulation of the sacral roots.

Magnetic stimulation using an external surface coil induces an electrodynamic field that penetrates various tissues and stimulates peripheral nerves in a similar fashion to conventional electrical stimulation. An 83 mm magnetic surface coil was used to stimulate 11 spinal cord injury (SCI) patients, during which time detrusor activity and evoked potentials of the striated urinary sphincter motor pathways were evaluated. All patients had urodynamic studies and conventional sacral evoked potentials prior to magnetic stimulation. The mean bladder capacity was 337 ml (range 109-590), mean leak point pressure was 50 cm H2O (range 10-80), and mean sacral reflex (afferent-efferent) latency was 37.9 ms (range 25.1-49.3). Eight patients had detrusor-sphincter dyssynergia. Magnetic stimulation over the sacral spine at different bladder volumes was performed. Detrusor and striated sphincter responses were recorded during stimulation. In all patients the technique was easy and the results were reproducible. The mean sacral motor pathway (efferent) latency was 27.9 ms (range 18.7-39.6). Using maximal stimulation, no detrusor response was recorded at bladder volumes < 200 ml. However, a detrusor response was recorded in 7 patients (> 10 cm H2O in 2, < 10 cm H2O in 5) when the bladder volume was > 200 ml. No complications were seen. Sacral evoked potential measurements assess the function and integrity of the sacral arc but it does not distinguish between afferent and efferent pathways. Magnetic stimulation is a safe and effective method to assess the integrity and function of the detrusor and striated sphincter motor (efferent) pathways. When combined with sacral evoked potential studies, the sensory (afferent) pathways can be evaluated indirectly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Transrectal ultrasound urodynamics.

Seventy-seven male patients (34 with cervical spine injury, 32 with thoracic spine injury, 9 with lumbosacral spine injury, and 2 with multiple sclerosis) who were referred to our spinal cord injury unit for urologic evaluation had videourodynamic studies using transrectal ultrasound and fluoroscopy. All were studied twice in the same session: first with transrectal ultrasound urodynamics (TRUSU) and the second time with conventional fluoroscopic videourodynamics (VUD). The findings were compared. Efficacy of TRUSU: (1) clearly documented flow of fluid through bladder neck into posterior urethra before clinical leakage occurred per urethra; (2) allowed accurate placement of EMG needle electrodes in external urinary sphincter under visual guidance; (3) provided high-quality imaging of surrounding structures and allowed assessment of bladder neck, prostate, seminal vesicles, and posterior urethra; (4) eliminated radiation exposure to the patient and the examiner, with no time limit imposed on imaging so that repeat studies could be done to evaluate patients on new drug treatments or postoperatively at no increased risks; and (5) its availability to most urologists at their office at considerably less cost to set up than fluoroscopy. In our study TRUSU identified a hypoechoic lesion in the prostate of 1 patient and a tumor in the bladder neck of another patient. Fluoroscopic VUD identified 6 patients with bladder diverticula and 2 with grades 1 and 2 vesicoureteral reflux which TRUSU did not identify. Our experience indicates TRUSU is a valid and preferable alternative to fluoroscopic VUD for patients with spinal cord injury.

Adult↗

PubMed1993

Infantile hypertrophic pyloric stenosis and hydronephrosis: is there an association?

Infantile hypertrophic pyloric stenosis is a common condition requiring surgical intervention during the first few weeks of life. The incidence of infantile hypertrophic pyloric stenosis ranges from 0.13 to 0.4% of live births in the United States, Britain and Scandinavia. Associated anomalies have been described in 6 to 33% of the cases in the central nervous system, gastrointestinal tract and heart. An association of infantile hypertrophic pyloric stenosis with urinary tract anomalies has not been previously documented. A review of 422 patients with infantile hypertrophic pyloric stenosis revealed urinary tract anomalies in 6 (10 renal units), including 4 renal units with vesicoureteral reflux and 9 with hydronephrosis. This incidence of 1.4% is greater than the 0.2% incidence expected in the general population. This 7-fold increase in urinary tract anomalies in patients with infantile hypertrophic pyloric stenosis suggests an association between the two and warrants further investigation. Serious consideration should be given to obtaining renal ultrasound examinations in patients with infantile hypertrophic pyloric stenosis.

Abnormalities, Multiple↗