Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where David M. Barrett is active.

Publication


Featured researches published by David M. Barrett.


The Journal of Urology | 1994

Long-term (15 years) results after radical prostatectomy for clinically localized (stage T2c or lower) prostate cancer.

Horst Zincke; Joseph E. Oesterling; Michael L. Blute; Erik J. Bergstralh; Robert P. Myers; David M. Barrett

To provide information about long-term outcome after radical prostatectomy for clinically localized prostatic cancer (stage T2c or lower), we undertook a retrospective analysis of 3,170 consecutive patients (mean age 65.3 +/- 6.4 years, range 31 to 81) with a mean followup of 5 years. Complication rates for patients who underwent prostatectomy before 1988 were compared with those who underwent radical prostatectomy more recently. Of the patients 49 (1.5%), 178 (5.6%), 897 (28%) and 2,047 (65%) had clinical stages T1a, T1b, T2a and T2b,c disease, respectively. The Gleason score was 3 or less in 292 patients (9%) and 7 or greater in 782 (25%). Overall, 438 patients (14%) died, 159 (5%) of cancer. The crude 10 and 15-year survival rates for all patients were 75% and 60%, respectively, which is comparable to the expected survival of a control group (67% and 46%). The cause specific survival rates were 90% and 82%, respectively, metastasis-free survival rates 82% and 76%, local recurrence-free survival rates 83% and 75%, overall recurrence-free rates 72% and 61%, and overall recurrence plus prostate specific antigen progression-free (greater than 0.2 ng./ml.) rates 52% and 40%, respectively. Clinical stage did not significantly affect survival but tumor grade was associated: 10 and 15-year cause specific survival rates were 95% and 93%, respectively, for a Gleason score of 3 or less, 90% and 82%, respectively, for a score of 4 to 6, and 82% and 71%, respectively, for a score of 7 or more. Of all patients 26% received adjuvant treatment (hormonal and/or radiation) within 3 months postoperatively because of advanced local pathological stage (pT3 or higher) or margin positive disease. The 30-day mortality rate was 0.3% (0% for 1,728 patients who underwent surgery in 1988 or later). Only 1 patient in the 70 year or older age group died during hospitalization. Complications decreased with time. In a contemporary group the complications were rectal injury in 0.6% of the patients, colostomy in 0.06%, myocardial infarction in 0.4%, deep venous thrombosis in 1.1%, pulmonary embolism in 0.7% and total urinary incontinence (3 or more pads per day) in 0.8%. Recent intraoperative blood loss was a median of 600 ml., and the incidence of recent need for any transfusion was 31% and it is presently less than 5%. In this series patients undergoing radical prostatectomy for clinically localized prostate cancer were usually healthy and, thus, had low co-morbidity. Survival rates at 10 and 15 years compare favorably with those of an age-matched control group.(ABSTRACT TRUNCATED AT 400 WORDS)


The Journal of Urology | 1985

Percutaneous Removal of Kidney Stones: Review of 1,000 Cases

Joseph W. Segura; Davide E. Patterson; Andrew J. LeRoy; Hugh J. Williams; David M. Barrett; Ralph C. Benson; Gerald R. May; Claire E. Bender

We report the results of 1,000 consecutive patients who underwent percutaneous removal of renal and ureteral stones. Removal was successful for 98.3 per cent of the targeted renal stones and 88.2 per cent of the ureteral stones. Complications, evolution and technique are discussed. Percutaneous techniques are an effective way to handle the majority of renal calculi and these techniques will continue to be important as shock wave lithotripsy becomes more widespread in the United States.


The Journal of Urology | 1998

MAYO CLINIC LONG-TERM ANALYSIS OF THE FUNCTIONAL DURABILITY OF THE AMS 800 ARTIFICIAL URINARY SPHINCTER: A REVIEW OF 323 CASES

Daniel S. Elliott; David M. Barrett

PURPOSEnWe determine the long-term durability of the AMS 800* artificial urinary sphincter in the correction of severe urinary incontinence, and evaluate mechanical versus nonmechanical failure and reoperation rates before (1983 to 1987) and after (1988 to present) the introduction of the narrow backing occlusive cuff design.nnnMATERIALS AND METHODSnFrom January 1983 to October 1994 more than 400 patients received an AMS 800 artificial urinary sphincter placed by 1 surgeon and 323, mean age 60.4 years, met study requirements for review. Mean followup was 68.8 months (range 18 to 153). Only patients with a minimum of 18 months of followup were included in the study. Of the 313 men and 10 women in the study group sphincters were placed at the urethra in 272 and at the bladder neck in 51. All patients were followed from surgery to the date of sphincter failure. Etiology of the failures was recorded and divided into mechanical versus nonmechanical sphincters placed before and after the introduction of the narrow backing cuff.nnnRESULTSnOverall, 58 of the 139 patients (42%) in the pre-narrow backing cuff group versus 31 of the 184 (17%) in the narrow backing cuff group required a first reoperation. Mechanical failure occurred in 29 cases (21%) with the pre-narrow backing and 14 (7.6%) with the narrow backing cuff. Nonmechanical failure developed in 24 cases (17%) with the pre-narrow backing and 17 (9%) with the narrow backing cuff. Ultimately 437 operations were required in the 323 patients, of whom 234 (72%) required no further surgical intervention at a mean followup of 68.8 months.nnnCONCLUSIONSnTechnological advances in the design and construction of the AMS 800 have dramatically decreased the reoperation and failure rates. These advances and improved surgical techniques provide an excellent long-term solution and increased continence in correctly selected patients with urinary incontinence.


Journal of Clinical Oncology | 1994

Radical prostatectomy for clinically localized prostate cancer: long-term results of 1,143 patients from a single institution.

Horst Zincke; Erik J. Bergstralh; Michael L. Blute; Robert P. Myers; David M. Barrett; Michael M. Lieber; Sandra K. Martin; Joseph E. Oesterling

PURPOSEnTo determine the efficacy and complication rate of radical prostatectomy (RP) as a treatment option for clinically localized prostate cancer (clinical stage < or = T2c).nnnMETHODSnThe study was a retrospective analysis of 1,143 consecutive patients (median age, 64 years; range, 38 to 79 y) who underwent RP at one institution (mean follow-up time, 9.7 years). Complications for this study population were compared with those of a contemporary group of 1,000 consecutive patients.nnnRESULTSnOf 1,143 patients, 83 (7%) had a low clinical stage (T1) and 160 (14%) had a low histologic grade (Gleason score < or = 3); 648 (57%) had a high clinical stage (T2b or T2c) and 204 (18%) had a high histologic grade (Gleason score > or = 7). Only 113 (10%) died of prostate cancer, and 177 (15%) developed metastasis. Adjuvant treatment (androgen deprivation or radiation therapy) was given in 197 (17%) patients (> or = pT3) and provided virtually identical results as without adjuvant treatment. The 10- and 15-year crude survival rates for 1,143 patients were 75% +/- 1.5% (SE) and 60% +/- 2.2%, respectively; the cause-specific survival rates were 90% +/- 1.1% and 83% +/- 1.9%, respectively; and the metastasis-free survival rates were 83% +/- 1.3% and 77% +/- 1.9%, respectively (398 men at risk at 10 years and 138 men at risk at 15 years). The 10-year survival rate for patients with Gleason score > or = 7 was 74% +/- 3.9%. Only tumor grade was a significant predictor for disease outcome. The hospital mortality rate decreased from 0.7% for the 1,143 study patients to 0% for the more recent 1,000 patients. Severe incontinence declined to 1.4% for the more recent 1,000 patients. Most patients who underwent RP were healthy (Charlson comorbidity index).nnnCONCLUSIONnSurvival at 15 years was similar to the expected survival rate. Current morbidity and mortality rates associated with RP were extremely low. Thus, RP has been a viable management option for men with clinically localized prostate cancer who have a life expectancy of more than 10 years.


The Journal of Urology | 2000

HIGH POWER POTASSIUM-TITANYL-PHOSPHATE LASER VAPORIZATION PROSTATECTOMY

Reza S. Malek; Randall S. Kuntzman; David M. Barrett

PURPOSEnWe prospectively studied a cumulative cohort of men with obstructive benign prostatic hyperplasia who underwent potassium-titanyl-phosphate (KTP) laser vaporization prostatectomy to determine the safety and efficacy of this procedure.nnnMATERIALS AND METHODSnA total of 55 men with symptomatic bladder outlet obstruction due to benign prostatic hyperplasia were treated with a 60 W. KTP laser produced by a prototype Laserscopedagger generator and delivered through a side-deflecting fiber with a 22Fr continuous flow cystoscope. Sterile water was used for irrigation. The prostatic lobes were vaporized to within capsular fibers. Mean lasing time plus or minus standard deviation was 44 +/- 19 minutes.nnnRESULTSnMean prostate volume plus or minus standard deviation was 43 +/- 14 ml. No patient had any significant blood loss or fluid absorption, or required blood transfusion. Foley catheters did not require irrigation and were removed less than 24 hours postoperatively. All patients remained satisfied with voiding outcome, which changed significantly (p <0.0001). Mean improvement in American Urological Association symptom score at 3, 6, 12 and 24-month intervals was 75%, 79%, 82% and 82%, respectively. Mean increase in peak flow rate at the same intervals was 250%, 242%, 255% and 278%, respectively. Complications included mild transient dysuria in 7%, bladder neck contracture in 2% and delayed hematuria in 4% of patients. None of the patients required re-catheterization or reoperation, or had incontinence or newly developed impotence. Of the sexually active patients 15% and 9% had retrograde ejaculation at 1 and 2 years, respectively.nnnCONCLUSIONSnOur observation in a 2-year period indicates that 60 W. KTP laser vaporization prostatectomy is safe and effective for quickly relieving bladder outlet obstruction with minimal postoperative complications, a high rate of patient satisfaction and, to date, a generally good outcome.


Urology | 1996

Optimized microvessel density analysis improves prediction of cancer stage from prostate needle biopsies

David G. Bostwick; Thomas M. Wheeler; Michael L. Blute; David M. Barrett; Gregory T. MacLennan; Thomas J. Sebo; Peter T. Scardino; Peter A. Humphrey; M'Liss A. Hudson; Yves Fradet; Gary J. Miller; E. David Crawford; Brent A. Blumenstein; Howard Mahran; Brian J. Miles

OBJECTIVESnClinical staging of prostate cancer is inaccurate, often with significant upstaging on final pathologic review. We previously demonstrated the ability to predict extraprostatic extension of cancer by use of the Gleason score and serum prostate-specific antigen (PSA) measurements. Herein we present an interim analysis of data from an ongoing multi-institutional study to determine the predictive power of an enhancement of microvessel density analysis in combination with Gleason score and serum PSA to predict extraprostatic extension.nnnMETHODSnWe evaluated a total of 186 randomly selected biopsy samples and matched totally embedded radical prostatectomy samples with preoperative PSA concentrations and patient demographics. Gleason score and optimized microvessel density (OMVD) were determined from the needle biopsy samples; pathologic stage was verified by independent review of the radical prostatectomy samples. An automated digital image analysis system measured microvessel morphology and calculated the OMVD in the biopsy samples (Biostage; Bard Diagnostic Sciences, Seattle, Wash).nnnRESULTSnPrediction of extraprostatic extension was increased significantly when OMVD analysis was added to Gleason score and serum PSA concentration (P = 0.003).nnnCONCLUSIONSnOptimized microvessel density analysis significantly increases the ability to predict extraprostatic extension of cancer preoperatively when combined with Gleason score and serum PSA concentration. This method appears to be a useful tool that can assist with treatment decisions in selected patients.


Urology | 1998

High-power potassium-titanyl-phosphate (KTP/532) laser vaporization prostatectomy: 24 hours later

Reza S. Malek; David M. Barrett; Randall S. Kuntzman

OBJECTIVESnTo study the feasibility and immediate postoperative outcome of vaporization prostatectomy by high-power potassium-titanyl-phosphate (KTP/532) laser in 10 men with bladder outlet obstruction due to benign prostatic hyperplasia (BPH) and to evaluate their clinical and voiding outcome 24 hours postoperatively.nnnMETHODSnThe KTP/532 laser at 60 W was produced by a prototype Laserscope generator and delivered through a side-deflecting fiber with a 22F continuous-flow cystoscope. Sterile water was used for irrigation. The prostatic lobes were readily vaporized to within capsular fibers. The mean lasing time was 29 +/- 8 minutes, during which a mean of 104.6 +/- 30 kJ of energy was delivered.nnnRESULTSnThe prostate volumes ranged from 22 to 60 mL (mean 38.4 +/- 9.7). None of the 10 patients had any significant blood loss or any fluid absorption. Foley catheters were removed in less than 24 hours postoperatively. All patients were satisfied with their voiding outcome. The mean peak urine flow rate increased from 8 +/- 1.3 mL/s preoperatively to 19.4 +/- 8.4 mL/s (142%, P = 0.003266) 24 hours postoperatively. Postvoid residual volumes remained essentially unchanged from their preoperative levels, as expected (P = 0.767423). One patient had urgency, but none had dysuria, hematuria, or incontinence or required recatheterization. Three patients have returned for 3-month follow-up; all 3 patients have had excellent results and are very satisfied with the outcome.nnnCONCLUSIONSnOur very early and limited experience indicates that high-power KTP/532 laser vaporization prostatectomy is feasible and appears to be safe and effective for quickly relieving bladder outlet obstruction due to BPH. Larger randomized clinical trials to compare this technique with standard transurethral resection of the prostate and more follow-up data are needed to determine its long-term efficacy and durability.


Surgical Clinics of North America | 1988

Urinary Incontinence in Adults

Bhalchandra G. Parulkar; David M. Barrett

Abnormalities of the micturition cycle are responsible for a large number of visits to the urologist. Some of these abnormalities produce annoying symptoms; others may lead to hazardous and disabling changes in the urinary tract. Urinary incontinence in adults results from an abnormality of one or more of the factors involved in the two phases of the micturition cycle: filling-storage and emptying. Proper management requires judicious selection among the pharmacologic and surgical alternatives.


Cancer | 1992

Stage D1 prostate cancer treated by radical prostatectomy and adjuvant hormonal treatment. Evidence for favorable survival in patients with DNA diploid tumors

Horst Zincke; Erik J. Bergstralh; Jeffrey J. Larson-Keller; George M. Farrow; Robert P. Myers; Michael M. Lieber; David M. Barrett; Charles C. Rife; Nick J. Gonchoroff

Background. Stage Dl disease is found in at least every sixth patient undergoing bilateral pelvic lymphadenectomy and radical retropubic prostatectomy (RRP) for clinically localized prostate cancer (PC). Previous recommendations for monotherapy using surgery, radiation, or systemic therapy alone for Stage Dl disease have usually been associated with a poor outcome in regard to progression and survival. Unlike other pathologic stages, D1 disease treated with RRP is mainly related to DNA ploidy pattern in regard to all end points (progression and survival) and immediate adjuvant hormonal treatment (AHT) rather than to the usual pathologic variables, including the number of positive nodes.


The Journal of Urology | 1989

Mayo Clinic Experience with use of the AMS800 Artificial Urinary Sphincter for Urinary Incontinence Following Radical Prostatectomy

Julio C. Gundian; David M. Barrett; Bhalchandra G. Parulkar

The model AMS800 artificial urinary sphincter was implanted in 117 patients with urinary incontinence resulting from radical prostatectomy. The indication for implantation was total incontinence in 107 patients and stress incontinence in 10. All patients had bulbous urethral cuff insertion and 20 had previous pelvic irradiation. Followup questionnaire indicated a 90% significantly improved continence rate and a 90% satisfaction rate among patients. There were 64 surgical revisions required in 37 patients: inadequate cuff compression in 21 (33%), tubing kinks in 10 (16%), urethral cuff erosion in 8 (13%), scrotal hematoma in 6 (9%), control assembly malfunction in 4 (6%) and cuff leaks in 4 (6%). Of the 20 patients with previous pelvic radiation 2 (10%) had at least 1 erosion, compared to 5 of 97 (5%) in the nonirradiated group. At followup 5 patients did not have at least 1 component of the AMS800 device indwelling (2 cuffs and 3 entire devices had been removed).

Collaboration


Dive into the David M. Barrett's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Michael L. Blute

University of Wisconsin-Madison

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge