Biomedical subjects

Kenneth M Peters

Publications and source records attributed to Kenneth M Peters.

13 recordsLinked to original sources

PubMed2007

Changes in urine markers and symptoms after bladder distention for interstitial cystitis.

PURPOSE: We evaluated changes in urine markers and symptom scores after bladder distention in patients with interstitial cystitis. MATERIALS AND METHODS: Study subjects were 33 new patients who had undergone no prior interstitial cystitis treatment. Urine specimens were taken before and 1 month after bladder distention. University of Wisconsin symptom scores were done the same day as the urine specimen collection. Urine marker levels and symptom scores before and after distention were compared. Changes in markers were tested for associations with changes in symptom scores and other markers. Markers and specific symptoms before distention were tested for their association with post-distention symptom improvement. RESULTS: After distention the median total University of Wisconsin score decreased significantly (28.5 before, 20 after, p <0.001). A total of 12 patients (36%) had at least 30% improvement in University of Wisconsin score, and 8 patients (24%) had at least 50% improvement. No pre-distention markers or symptoms predicted which patients would have a good response. There were 2 urine markers that improved significantly after distention: anti-proliferative factor activity (median -96% before, -17% after, p <0.001) and heparin-binding epidermal growth factor-like growth factor levels (median 0.34 ng/mg creatinine before, 4.1 after, p <0.001). None of the changes in urine markers associated with changes in symptom scores. CONCLUSIONS: The median symptom score for newly diagnosed patients with interstitial cystitis decreased after distention, but only a minority of patients had at least 30% symptom improvement. Bladder distention altered urine anti-proliferative factor activity and heparin-binding epidermal growth factor-like growth factor levels toward normal, but the mechanism of symptom relief after distention is still unknown.

Adult↗

PubMed2006

Frequency, urgency, and pelvic pain: treating the pelvic floor versus the epithelium.

For years the bladder epithelium has been the focus for diagnosing and treating the frequency, urgency, and pelvic pain of interstitial cystitis. However, many patients have not found symptom relief with these therapies. Pelvic floor dysfunction is often present in these patients, yet it is often untreated. Pelvic floor dysfunction may be related to abuse, past surgeries, or other causes. It is important to look outside of the bladder and explore other causes and treatments for this condition. Pelvic floor therapies should be a first line of treatment for those women with chronic pelvic pain related to pelvic floor dysfunction.

Cystitis, Interstitial↗

PubMed2005

Sacral versus pudendal nerve stimulation for voiding dysfunction: a prospective, single-blinded, randomized, crossover trial.

AIMS: The objective of the study was to compare sacral nerve stimulation (SNS) to pudendal nerve stimulation (PNS) for voiding dysfunction. METHODS: Thirty subjects with voiding dysfunction had a tined lead placed at S3 and a second electrode implanted at the pudendal nerve via a posterior approach. In a blinded, randomized fashion, each lead was tested for 7 days. Voiding diaries and questionnaires were completed and outcomes monitored. RESULTS: The time to place a sacral lead was 25.85 min, pudendal lead 23.71 min (P = 0.57). Twenty-four of 30 (80%) subjects responded and had a permanent implant placed. PNS was chosen as a superior lead in 79.2%, SNS was superior in 20.8%. The order in which the lead was simulated had no impact on the final lead implanted and no carry over effect was seen. Overall reduction in symptoms was 63% for PNS and 46% for SNS (P = 0.02). On a 7-point scale from markedly worse to markedly better, the pudendal lead was superior to sacral for pelvic pain (P = 0.024), urgency (P = 0.005), frequency (P = 0.007), and bowel function (P = 0.049). Complications were minimal. CONCLUSIONS: This is the first blinded study of sacral versus pudendal stimulation for voiding dysfunction. Successful implantation of a pudendal lead was achieved in all subjects. The majority of subjects chose PNS to be superior to SNS. More patients and longer term data is needed to confirm these promising results.

Adult↗

PubMed2005

Comparison of dry mouth in women treated with extended-release formulations of oxybutynin or tolterodine for overactive bladder.

The incidence, severity and tolerability of dry mouth was compared in 790 women with overactive bladder who were treated with extended-release oxybutynin chloride 10 mg/day or extended-release tolterodine tartrate 4 mg/day for 12 weeks in a multicenter, double-blind, parallel-group study. Dry mouth was the most common adverse event associated with treatment, with an incidence rate of 28.1% in the oxybutynin group and 21.6% in the tolterodine group (P = 0.039). The majority of dry mouth events were mild in both treatment groups. Severe dry mouth occurred in 1.5% and 0.5% of patients in the oxybutynin and tolterodine groups, respectively (P = 0.173). Seven patients on extended-release oxybutynin and 4 patients on extended-release tolterodine discontinued treatment due to dry mouth (P = 0.380). The results of this analysis showed that dry mouth was common with both treatments, but most events were mild; there was no difference in the rate of severe dry mouth or in the rate of withdrawal due to dry mouth.

Adolescent↗

PubMed2005

Expanding indications for neuromodulation.

Neuromodulation in one form or another has been studied for decades for various disease states. Although its mechanism of action remains un-explained, numerous clinical success stories suggest it is a therapy with efficacy and durability. Controlled studies have led to the approval of sacral neuromodulation for urinary urgency and frequency, urinary retention, and urinary urge incontinence. The future holds hopeful possibilities for the application of neuromodulation, namely in the areas of interstitial cystitis, in-tractable pain syndromes, fecal incontinence and constipation, spinal cord injury, and erectile dysfunction. Neuromodulators have also been used in nonurologic conditions, including chronic headaches and intractable chest pain. In adults and children, in the neurologically intact and neurologically impaired, neuromodulation has been shown to improve the quality of life of those suffering chronic disease states. Neuromodulation is changing the future of urology. Treatment of voiding dysfunction and likely other disorders, such as pelvic pain, sexual dysfunction, and bowel disorders, will no longer rely only on medications that are "OK" or destructive-reconstructive procedures that suffer from significant complications. Rather, by modulating the nerves, the urologists will treat these disorders in a minimally invasive fashion and neuromodulation will become the first-line therapy before any major surgery is undertaken.

Adult↗

PubMed2005

Do the National Institute of Diabetes and Digestive and Kidney Diseases cystoscopic criteria associate with other clinical and objective features of interstitial cystitis?

PURPOSE: We compared urine markers, bladder biopsy findings and clinical features of patients with symptoms of interstitial cystitis (IC) who did or did not meet the cystoscopic criteria defined by the National Institute of Diabetes and Digestive and Kidney Diseases. MATERIALS AND METHODS: Urine markers and symptom questionnaires were measured before and 1 month after bladder distention for IC. Bladder biopsies were taken at the time of distention. At distention patients were defined as meeting or not meeting the National Institute of Diabetes and Digestive and Kidney Diseases established cystoscopic criteria for IC. The 2 patient groups were compared. RESULTS: Urine marker levels were similar for the 2 groups, including antiproliferative factor, epidermal growth factor, heparin binding epidermal growth factor-like growth factor, cyclic guanosine monophosphate, interleukins 6 and 8, and methylhistamine. Bladder biopsy features were similar for the 2 groups. Bladder capacity with the patients under anesthesia was higher in those who did not meet the criteria (median 750 vs 1,000 ml, p = 0.005). Median age at symptom onset was 26 years in both groups. On the University of Wisconsin symptom scale patients who met the criteria had higher scores for daytime frequency (p = 0.002) and nocturia (p = 0.01). Symptom characteristics and symptom response after bladder distention were similar for the 2 groups. CONCLUSIONS: Patients who met the cystoscopic criteria had worse daytime frequency and nocturia, and lower bladder capacity under anesthesia. However, the 2 groups had similar urine markers and bladder biopsy findings. The cystoscopic criteria do not appear to identify a distinct pathophysiological subset of patients with IC symptoms.

Adult↗

PubMed2005

A randomized controlled trial of intravesical bacillus calmette-guerin for treatment refractory interstitial cystitis.

PURPOSE: We compared intravesical bacillus Calmette-Guerin (BCG) to placebo instillations in patients with treatment refractory interstitial cystitis (IC). MATERIALS AND METHODS: Subjects who met the National Institutes of Health-National Institute for Diabetes and Digestive and Kidney Diseases criteria for IC, and reported at least moderate pain and frequency for a minimum of 6 months before study entry, were randomized to 6 weekly double-blinded intravesical instillations of either BCG or placebo, and then followed for a total of 34 weeks. The primary outcome was a patient reported global response assessment at week 34, supplemented with medications for IC during weeks 31 to 34. Secondary outcomes included a 24-hour voiding diary, pain, urgency, validated IC symptom indexes and adverse events. The target sample size was 260 participants, designed to detect a difference in response rates between placebo and BCG of 30% and 50%, respectively. RESULTS: A total of 265 participants were randomized and 17 (6%) patients withdrew from study. The response rates for the primary outcome were 12% for placebo and 21% for BCG (p = 0.062). Small improvements were observed for all secondary outcomes, some more so with BCG, but these differences were of borderline statistical significance. Although a large number of adverse events were reported in the BCG arm, there was no statistically significant difference between the treatment arms in overall adverse event rates. CONCLUSIONS: Although the BCG safety profile was acceptable, the response rate for the primary outcome was low. Effective medical treatment for patients with moderate to severe interstitial cystitis remains elusive.

Administration, Intravesical↗

PubMed2004

A referral center's experience with transitional cell carcinoma misdiagnosed as interstitial cystitis.

PURPOSE: There has been a recent trend to diagnose interstitial cystitis (IC) in a noninvasive way using a potassium sensitivity test, and a pelvic pain, urgency and frequency questionnaire. The concern is that significant pathology causing the bladder symptoms may be missed, such as transitional cell carcinoma. We present our experience with patients "labeled" as having IC who truly had cancer as the cause of irritative symptoms. MATERIALS AND METHODS: A retrospective review of patient records at our IC center was performed from 1998 to 2002. A total of 600 patients were seen at that time with the diagnosis of interstitial cystitis. RESULTS: Six patients (1%) previously diagnosed as having IC were found to have transitional cell carcinoma as the cause of symptoms, 4 of whom (67%) had no hematuria. Mean time from the diagnosis of IC to diagnosis of transitional cell carcinoma was 29.8 months. Irritative bladder symptoms resolved after identifying and treating the malignancy. CONCLUSIONS: Patients with irritative voiding symptoms require a thorough evaluation which may include cystoscopy, cytology and upper tract imaging. Hematuria was not a good predictor of cancer in our series. In the era before widespread use of minimally invasive means to diagnose IC (ie potassium sensitivity test, pelvic pain, urgency and frequency questionnaire) 1% of patients who were considered to have IC actually had transitional cell cancer as the cause of symptoms. One would expect that this number would increase if the criteria to diagnose IC and initiate treatment were oversimplified. Interstitial cystitis remains a diagnosis of exclusion.

Adult↗

PubMed2004

Is urine methylhistamine a useful marker for interstitial cystitis?

PURPOSE: We determined whether urine methylhistamine (MH) is associated with other clinical features and bladder biopsy findings in interstitial cystitis (IC). MATERIALS AND METHODS: Urine MH and University of Wisconsin symptom scores were measured before and 1 month after bladder distention for IC. Bladder biopsies were done at the time of distention. In new patients with IC who met cystoscopic criteria urine MH was compared before and after distention, and changes in urine MH were compared with changes in symptom scores. Pre-distention urine MH was tested for associations with the results of a symptom questionnaire, symptom response after distention, cystoscopic findings and bladder biopsy findings. RESULTS: There were no significant associations between urine MH and symptom scores, response to bladder distention, cystoscopic findings or bladder biopsy features, including mast cell count by tryptase staining. Urine MH was similar in new patients with IC who did vs did not meet cystoscopic criteria. Urine MH was similar in new vs chronically treated patients with IC. CONCLUSIONS: Urine MH is unlikely to be useful as an objective marker of the response to bladder distention, as a method to predict which patients will respond to bladder distention or as a noninvasive substitute for bladder biopsy and mast cell counts by tryptase staining.

Adult↗

PubMed2003

Sacral neuromodulation for the treatment of refractory interstitial cystitis: outcomes based on technique.

Patients with refractory interstitial cystitis (IC) underwent testing with sacral nerve modulation via either a traditional percutaneous approach or a staged procedure. Implanted patients were followed with scaled questionnaires and voiding diaries. Twenty-six patients who had a permanent InterStim placed had a reduction in 24-h voids of 51%. More than two-thirds of patients reported a moderate or marked improvement in urinary frequency, urgency, pelvic pain, pelvic pressure, incontinence and overall quality of life. The test to implant rate of a traditional percutaneous procedure was 52%, compared to a staged procedure of 94%. Assessing sensory response at the time of implant reduced the reoperation rate from 43% to 0%. Ninety-six per cent stated they would undergo an implant again and recommend the therapy to a friend. We concluded that sacral nerve modulation can treat refractory IC symptoms. The response to therapy and the reoperation rate are dependent on the technique used to test and implant the device.

Adolescent↗

PubMed2003

Comparison of APF activity and epithelial growth factor levels in urine from Chinese, African-American, and white American patients with interstitial cystitis.

OBJECTIVES: Interstitial cystitis (IC) is a chronic bladder disorder for which the etiology is unknown. We have previously shown that antiproliferative factor (APF), heparin-binding epidermal growth factor-like growth factor (HB-EGF), and epidermal growth factor (EGF) are sensitive and specific biomarkers for IC in white American patients. Because little is known about the epidemiology of this disorder, it is unclear whether these factors would also be useful biomarkers for IC in patients from different racial groups and/or geographic locations. METHODS: Urine specimens were collected from Chinese, white American, and African-American women with IC and age and race-matched asymptomatic normal control women. APF activity was determined by (3)H-thymidine incorporation into primary normal adult human bladder epithelial cells in vitro. The HB-EGF and EGF urine levels were determined by enzyme-linked immunosorbent assay. RESULTS: The Chinese, African-American, and white American women with IC had significantly greater urine APF activity (P <0.000001, P = 0.0008, and P <0.000001, respectively), lower urine HB-EGF levels (P <0.000001, P = 0.02, and P <0.000001, respectively), and greater urine EGF levels (P <0.000001, P = 0.002, and P <0.000001, respectively), than their matched asymptomatic controls. CONCLUSIONS: These findings confirm the utility of APF, HB-EGF, and EGF as biomarkers for IC in patients from three different racial groups and two different countries.

Adult↗

PubMed2002

Clinical and pathologic tumor size in renal cell carcinoma; difference, correlation, and analysis of the influencing factors.

OBJECTIVES: To investigate the relation between the clinical and pathologic size and to identify the factors that affect this relationship. The clinical size of the tumor is essential for choosing the appropriate treatment in renal cell carcinoma. The pathologic size, on the other hand, is an important prognostic indicator. METHODS: We reviewed the charts of 291 open nephrectomy patients treated for nonmetastatic renal cell carcinoma. Clinical size was defined as the largest diameter on contrast-enhanced computed tomography. Pathologic size was defined as the largest diameter on pathologic examination. The clinical and pathologic sizes were compared, and their correlation was analyzed. The effect of various clinical and pathologic factors on the percentage of the size difference (%Delta(size)) was analyzed. RESULTS: The mean clinical and pathologic size was 5.4 +/- 3.2 and 5.3 +/- 3.3 cm, respectively. The difference was not significant (P = 0.1679). The clinical and pathologic size also correlated highly (r = 0.9540; P <0.0001). The estimated blood loss, local tumor extension, and cell type had significant influence on the %Delta(size) (P = 0.0018, 0.0415, and 0.0079, respectively). Additionally, in approximately one half of the patients with the greatest size difference, features such as cystic masses, hemorrhage, pyelonephritis, localization near or invasion of the collecting system, cysts or dilated calices adjacent to the tumor, and multiple cysts within the kidney were present, which were identified as factors that might have influenced the accuracy of the clinical size. CONCLUSIONS: The overall accuracy of the clinical size and its correlation with the pathologic size was acceptable. However, the presence of the above-mentioned factors should be taken into consideration during the interpretation of clinical tumor size.

Carcinoma, Renal Cell↗

PubMed2002

Neuromodulation for the treatment of refractory interstitial cystitis.

Interstitial cystitis (IC) is a symptom complex of urinary urgency, frequency and pelvic pain. Multimodality behavioral and phamacologic treatment is often effective in treating IC. Unfortunately, some patients with IC are refractory to standard treatments. Neuromodulation has been shown to be effective in treating voiding dysfunction. Small studies have demonstrated improvement in pelvic pain and IC symptoms during temporary sacral nerve stimulation. This current study demonstrates that patients refractory to traditional therapies for IC can respond well to sacral nerve stimulation and maintain improvement in symptoms after permanent implantation of a neurogenerator. The technique used to place the neurostimulator can impact on the degree of the response and the complication rate. Sacral neurostimulation continues to evolve and should be in the armamentarium available to treat voiding dysfunction.

Journal Article↗