Biomedical subjects

A D Kohan

Publications and source records attributed to A D Kohan.

4 recordsLinked to original sources

PubMed2000

Effect of aging on bladder function and the response to outlet obstruction in female rats.

Bladder dysfunction in the aging population is a significant problem. However the concomitant presence of other diseases in many patients can make it difficult to distinguish between changes in bladder function and other influences. The present study was designed to study, in aging rats, bladder function and the effect of partial bladder outlet obstruction (BOO) on bladder function. Cystometrics were performed in awake, female Fischer 344 rats of four age groups (6, 12, 18 and 24 months) following subcutaneous implantation of a mediport catheter. Cystometric evaluations were carried out in control rats or those subject to three weeks of BOO. Bladder compliance significantly decreased with aging, which reflected an increase in threshold pressure without changes in bladder capacity. Partial BOO caused development of severe bladder instability. Following BOO, bladder capacity and compliance were significantly increased in all age groups. Threshold pressure was lower in obstructed animals, except for 6-month rats. Younger animals were able to generate a higher contraction pressure to compensate for the BOO, whereas older animals did not. Using an awake model of cystometric measurement, we have demonstrated that aging, by itself can affect bladder function. Furthermore, aged animals respond differently to BOO than younger animals. These results demonstrate that both aging and disease can contribute to bladder dysfunction, and suggest that treatment of bladder dysfunction may require a combination of therapies targeted to multiple etiologies.

Aging↗

PubMed2000

The perioperative charge equivalence of interstitial brachytherapy and radical prostatectomy with 1-year followup.

PURPOSE: We compare the comprehensive 1-year charges in a consecutive group of patients undergoing radical prostatectomy and transperineal interstitial brachytherapy for clinically localized prostate cancer at a single urban institution. MATERIALS AND METHODS: A total of 60 consecutive men with clinically localized prostate cancer (T1-T2, N0, M0) were treated during a 15-month period with radical prostatectomy or interstitial brachytherapy. Hospital and outpatient records were analyzed for each patient in regard to preoperative, operative and postoperative charges. Parameters included number of encounters, diagnostic and therapeutic interventions, hospitalization and operative charges, and followup visits, diagnostic tests and interventions for 1 year. All charge calculations were based arbitrarily on the 1996 Medicare fee schedule, factoring in the mandated global charge reimbursement period of 90 days for both procedures. RESULTS: Of the patients 38 underwent radical prostatectomy (prostatectomy group) and 22 underwent interstitial brachytherapy (brachytherapy group). The brachytherapy group was older with higher pretreatment serum prostate specific antigen and clinical stage disease, and more frequently received neoadjuvant hormonal therapy compared to the prostatectomy group. The 2 groups were similar in Gleason score and, when applicable, duration of neoadjuvant hormonal therapy. Preoperative charges were 15.3% lower for prostatectomy than for brachytherapy (not statistically significant). Conversely, operative charges for prostatectomy were 13.5% higher (p = 0.04). The major difference among preoperative, operative and postoperative charges was for those incurred postoperatively by the brachytherapy group, which were 56.0% higher than those for the prostatectomy group ($2,285.20 versus $1,007.20, p = 0.0004). CONCLUSIONS: Transperineal interstitial seed implantation is perceived by many as more cost-effective than radical prostatectomy for patients with clinically localized prostate cancer. We demonstrated that when such patients were followed for 1 year, the comprehensive charges for radical prostatectomy and interstitial brachytherapy were equivalent.

Adult↗

PubMed1999

Indinavir urolithiasis: an emerging cause of renal colic in patients with human immunodeficiency virus.

PURPOSE: We evaluate the clinical, diagnostic and radiographic findings in patients on indinavir therapy who presented with renal colic, and propose appropriate treatment options for indinavir urolithiasis. MATERIALS AND METHODS: A total of 16 patients positive for human immunodeficiency virus on indinavir were evaluated for 18 episodes of severe renal colic requiring hospitalization. Laboratory evaluation was performed in all patients followed by an imaging study. Conservative treatment included intravenous hydration, narcotic analgesics and temporary cessation of indinavir. Intervention was elected only in patients with persistent fever or intractable pain. A month after hospital discharge an excretory urogram and metabolic stone evaluation were performed. Mean followup was 9.3 months and 2 patients had recurrent symptoms. RESULTS: All patients presented with nausea or vomiting and hematuria. Imaging studies confirmed obstruction in all patients with 13 radiolucent (indinavir) and 3 radiopaque (calcium oxalate) stones. Patients with radiolucent and radiopaque stones demonstrated significant differences in urinary pH (p = 0.002) and serum creatinine (p = 0.03). Conservative therapy was successful in 11 patients (68.8%) within 48 hours and 4 patients (25%) with radiolucent calculi required endoscopic stenting for persistent fever. Metabolic stone evaluation demonstrated significant hypocitruria (less than 50 mg./24 hours) in all patients with radiolucent calculi. CONCLUSIONS: The urologist should be familiar with this growing cause of renal colic in patients on indinavir therapy. Pure indinavir stones are radiolucent and have a soft, gelatinous endoscopic appearance. Conservative treatment is successful in most patients and if intervention is deemed medically necessary, endoscopic stent placement should be the procedure of choice.

Acquired Immunodeficiency Syndrome↗

PubMed1998

Cost-effective hydrocele ablation.

PURPOSE: The surgical repair of hydroceles can be relatively expensive in some cases in terms of costs and initial limitation of activity. We ascertain whether aspiration and sclerotherapy of hydroceles is a safe, efficient, cost-effective treatment modality in select patients. MATERIALS AND METHODS: In 47 patients 51 hydroceles were treated in the office with aspiration and instillation of a sclerosing solution based on a sodium tetradecyl sulfate preparation. One treatment was done in 14 cases and 2 in the remainder. Medicare data for 1995 were used for charge analysis. RESULTS: The overall success rate was 61% (34 of 51 cases) with success defined as no perceptible ipsilateral scrotal fluid reaccumulation on palpation by a physician and complete patient satisfaction. The failure rate was 39% (17 cases) with failure defined as perceptible ipsilateral scrotal fluid reaccumulation on palpation by a physician and/or patient dissatisfaction. The charge differential of surgery versus aspiration and sclerotherapy was greater than 9:1. CONCLUSIONS: The aspiration and sclerotherapy technique that we used appears to be an efficacious, safe, cost-effective treatment modality in select patients with idiopathic hydroceles.

Aged↗