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Biomedical subjects

D M Barrett

Publications and source records attributed to D M Barrett.

At least 19 recordsLinked to original sources
PubMed1995

Visual laser ablation of the prostate: a preliminary report.

OBJECTIVE: To report our preliminary experience with visual laser ablation of the prostate (VLAP) for treating bladder outlet obstruction caused by benign prostatic hyperplasia (BPH) and to evaluate its short-term outcome. DESIGN: We reviewed our laser technique in 47 men with symptomatic obstruction caused by BPH who underwent VLAP between July 1992 and April 1993 at our institution, and we compared our results with those reported in the literature. MATERIAL AND METHODS: Our 47 patients were from 43 to 87 years old (mean, 69.6). The mean pretreatment American Urological Association symptom score was 22, mean peak flow rate was 9.5 mL/s, and mean postvoid residual urinary volume was 136 mL. Neodymium:yttrium-aluminum-garnet laser energy was delivered at the 2-, 4-, 8-, and 10-o'clock positions and, when necessary, to the median lobe by one of two lateral-firing laser probes. All but the first four patients were treated on an outpatient basis, and all patients were catheterized (Foley catheter) for 2 to 10 days after VLAP. RESULTS: Of the 47 patients, 32 had data pertaining to a mean follow-up of 5 months; they had a mean symptom score of 10, mean peak flow rate of 15.7 mL/s, and mean postvoid residual volume of 63 mL. In 12 patients, data from a mean follow-up of 11 months were available; they had a mean symptom score of 6, mean peak flow rate of 18.8 mL/s, and mean postvoid residual volume of 10 mL. Perioperative complications (myocardial infarction, thrombophlebitis, and epididymitis) in three patients responded to conservative therapy. Urinary retention occurred for 2 to 60 days after initial removal of the Foley catheter in 12 patients, who then had resumption of spontaneous voiding. In three patients who stated their condition was worse postoperatively, conventional transurethral resection of the prostate was done 6 months after VLAP, and a fourth patient had a persistently obstructive bladder neck incised 8 months after VLAP. CONCLUSION: Our early experience and that reported in the literature indicate that VLAP is a safe and efficacious alternative treatment of obstructive BPH. Although the early results of VLAP rival those of transurethral resection of the prostate, the success rate in treating large prostates should be improved, and long-term results should be assessed to determine the durability of the beneficial effects.

Adult↗
PubMed1995

Diversion.

Explore the source record for details and available documents.

Humans↗
PubMed1995

Particulate silicone for use in periurethral injections: local tissue effects and search for migration.

We examined the histologic behavior and migratory tendencies of a silicone-based injectable paste (Macroplastique) with potential application in treating urinary incontinence. Thirteen female dogs were studied. Six received 2 periurethral injections of large-particle paste, with a median diameter of 110 microns, and 7 received similar injections with small-particle paste (median diameter, 73 microns). The paste was radiolabeled with cobalt-57. Histologic analysis was performed at 4 or 9 months. The pathologic appearance revealed intact large-particle injection sites. The small-particle sites had dissipated significantly. This was confirmed by nuclear imaging. Large particles produced an encapsulated fibrous sheath without local migration. There was a histiocytic reaction within the injection site but no granuloma formation. Distant migration was observed in 1 dog (short term, large particle), without an inflammatory response. Migration of silicone occurred locally and distantly in animals that received small particles. X-ray microanalysis confirmed the presence of silicone particles.

Animals↗
PubMed1994

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

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)

Adult↗
PubMed1994

Prosthetic bladder: in vivo studies on an active negative-pressure-driven device.

Active alloplastic bladders were implanted into four dogs after cystectomy and were well tolerated. The prosthesis created a vacuum of -90 cm. H2O in the upper tracts, which gradually decreased until the bladder filled. Renal function was maintained as long as the prostheses worked effectively. Hydronephrosis developed and renal function deteriorated if the bladder was not emptied, even though the leak pressure was only 3 to 5 cm. H2O. Both resolved when active bladder function was restored. Pressures in the ureter were measured percutaneously, at flow rates up to 15 ml. per minute (900 ml. per hour). At 15 ml. per minute, the pressure only reached a maximum of 16 cm. H2O. Encrustation did not occur even in the presence of infection. The results achieved with this negative pressure bladder prosthesis, which is emptied actively, are very promising and should provide the impetus for increased research in this field of urology.

Animals↗
PubMed1994

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

PURPOSE: To determine the efficacy and complication rate of radical prostatectomy (RP) as a treatment option for clinically localized prostate cancer (clinical stage < or = T2c). METHODS: The 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. RESULTS: Of 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). CONCLUSION: Survival 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.

Adult↗
PubMed1994

Correlation between urinary flow rate, voided volume, and patient age in a community-based population.

This investigation is unique in that is the first study to use a large number of randomly chosen men from the community to establish the relationship between: 1) urinary flow rate and voided volume, 2) urinary flow rate and patient age, 3) voided volume and patient age, and 4) the time to achieve peak urinary flow rate and patient age. The results clearly indicate that both the peak and mean urinary flow rate decreases with advancing age. The voided volume also diminishes with increasing age. The time required to achieve the peak urinary flow rate, however, appears to be independent of the patient's age. Irrespective of age, approximately 9 seconds are required to achieve the maximum urinary flow rate. Because the urinary flow rate is dependent upon both the quantity of urine voided and the patient's age, it is necessary to account for the influence of both parameters when establishing the "normal range" for peak urinary flow rate. To this end, nomograms estimating the peak urinary flow rate percentile as a function of voided volume and patient age have been generated and are included in this report. These nomograms, based on a large, randomly selected population, should make peak urinary flow rate a more reliable diagnostic modality for assessing bladder outlet obstruction. They also should be most useful to the practicing clinician when interpreting the results of a peak urinary flow rate determination for a patient presenting with symptoms of prostatism.

Adult↗
PubMed1993

Rectal injury occurring at radical retropubic prostatectomy for prostate cancer: etiology and treatment.

Of 2,212 patients who underwent radical retropubic prostatectomy for the treatment of prostate cancer, 27 had documented rectal injuries. All but one were detected immediately at the time of surgery and were repaired; a temporary diverting colostomy was established in 6 patients. Follow-up on these patients ranged from nine to one hundred eighty-five months (mean, 68 months). Four patients had fistulas between the rectum and the urinary tract that required additional surgery. Factors that predisposed patients for intraoperative injury to the rectum include a history of previous pelvic radiation therapy, previous rectal surgery, and previous transurethral resection of the prostate (P < 0.01). Higher local tumor stage did not significantly increase the risk of rectal injury at the time of radical retropubic prostatectomy. Preoperative bowel preparation may obviate colostomy; it may still be necessary in high-risk patients with suboptimal local repair.

Aged↗
PubMed1993

Experience with AS 800 artificial sphincter in pediatric and young adult patients.

Congenital or acquired sphincteric urinary incontinence in children and young adults is a severe social and physical burden. As a therapeutic option, we implanted 61 AS 800 artificial sphincters in 59 patients (46 males and 13 females). The mean age of the patients was 17.5 years (range, 6 to 34 years), and mean follow-up was forty-three months (range, 5 to 84 months). In addition to artificial sphincter implantation, intestinal cystoplasty was required in 22 patients to obviate problems of increased detrusor contractility or decreased detrusor compliance, or both. Continence was good in 47 patients (80%) and fair in 8 (14%). Four patients (7%) were awaiting sphincter modification or cystoplasty, or both. Careful and prolonged follow-up is mandatory in all patients managed in this fashion to preclude the deleterious effects of subtle changes in detrusor or ureteral function on the integrity of the upper urinary tracts.

Adolescent↗
PubMed1993

Natural history of prostatism: urinary flow rates in a community-based study.

Urinary flow rates were measured in a randomly selected community sample of more than 2,000 men 40 to 79 years old with no history of prostate surgery, prostate cancer or certain other diseases known to interfere with normal voiding. Peak urinary flow rates decreased from a median of 20.3 ml. per second in men 40 to 44 years old to 11.5 ml. per second for men 75 to 79 years old, while voided volumes decreased from a median of 355.5 to 222.5 ml. for the same age ranges. Peak flow rates of less than 10 ml. per second were found in 6% of the men aged 40 to 44 years, increasing to 35% among men aged 75 to 79 years. Urological standards for peak urinary flow rate should be based on community data, and should account for age and voided volume. Our study may serve as the starting point for the development of community-based flow rate normal ranges. Nomograms are given to permit estimating flow rate percentiles as a function of age and voided volume.

Adult↗
PubMed1993

Subcutaneous port for longterm access and administration of topical chemotherapy to the upper urinary tract.

Fourteen silicone pigtail catheters were inserted into the renal pelves of ten 25 kg. pigs. These catheters were connected to injection ports implanted in the flank. Each animal received 15 mg. of thiotepa, into one port, weekly for 8 weeks. These were well tolerated. Percutaneous radiography and histological examination showed effective distribution of thiotepa throughout the upper urinary tract. Microscopic changes included cytoplasmic vacuolation, cystic changes and denudation of the mucosa. There was edema and chronic inflammatory infiltrate in the submucosa. This method of access to the upper tracts should be considered for long-term recurrent treatment of upper tract superficial transitional cell carcinoma.

Administration, Topical↗
PubMed1993

Success of the narrow-backed cuff design of the AMS800 artificial urinary sphincter: analysis of 144 patients.

The narrow-backed cuff design of the AMS800 artificial urinary sphincter was introduced to improve transmission of cuff pressure to underlying tissue and, theoretically, to decrease the incidence of cuff erosion. The AMS800 urinary sphincter with this design change was implanted in 136 male and 8 female patients (mean age 57 years). Mean followup was 28 months. The cuff was placed around the bladder neck in all 8 female and in 29 male patients, and it was implanted around the bulbous urethra in the remaining 107. The 4.5 cm. cuff in combination with the 61 to 70 cm. pressure balloon was implanted in 109 patients. There were 12 device failures and 12 surgical complications. Five patients required cuff removal and none required reoperation for inadequate cuff pressure. Postoperatively, 132 patients reported satisfactory continence. The design change of the AMS800 and the use of the 4.5 cm. cuff with the 61 to 70 cm. pressure balloon decreased the incidence of cuff erosion and the need for reoperation for inadequate cuff pressure.

Adolescent↗
PubMed1992

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

BACKGROUND: Stage D1 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 D1 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. METHODS: Complete DNA ploidy information was available in 370 patients with Stage D1 disease (age range, 40-77 years; mean, 64 years) undergoing RRP with or without AHT with a follow-up of up to 22 years (mean, 5 years). RESULTS: Overall, 80% of all DNA ploidy classes (diploid, 37%; tetraploid, 46%; and aneuploid, 17%) had AHT that highly significantly delayed progression for diploid (P less than 0.0001) more than tetraploid (P less than 0.0001) and more than aneuploid (P less than 0.0001) tumors. Significant prolongation of the disease-free interval might have improved the quality of life for tetraploid and aneuploid patients. Survival (crude and cause-specific) was significantly (P = 0.02) improved only for diploid patients who received AHT but not for tetraploid and aneuploid patients. This was due to the significantly accelerated death rate after progression in those patients with early AHT for tetraploid and aneuploid (but not diploid) tumors. Delayed (on progression only) AHT resulted in high progression rates for all DNA ploidy classes (aneuploid greater than tetraploid greater than diploid); e.g., 21 of 30 diploid patients progressed and 6 patients died from disease at a median of 31.5 months in spite of immediate hormone treatment on progression. RRP and AHT for patients with Stage D1 disease resulted in a highly significant delay in overall progression (76% at 10 years) and excellent local control, depending on DNA ploidy pattern (diploid greater than tetraploid greater than aneuploid) compared with a treatment regimen without AHT (24% overall nonprogression); only 20% of all patients with AHT are projected to die of disease at 10 years. Disease in diploid patients (37%) treated with AHT rarely progressed and those patients are unlikely to die of disease in 10 years or less; delayed (on progression) hormone treatment for diploid patients seemed ineffective. Inclusion of values for prostate specific antigen led to a higher failure rate on progression, and this is dependent on DNA ploidy class (diploid greater than tetraploid greater than aneuploid). CONCLUSION: Only patients with nondiploid tumors should be entered into prospective studies using innovative adjuvant treatment protocols to improve survival.

Adult↗
PubMed1992

Patient and partner satisfaction with the AMS 700 penile prosthesis.

Patient and partner satisfaction with the use of an AMS 700 inflatable penile prosthesis was evaluated by reviewing the records from 387 patients and questionnaires completed by 272 of these patients. The evaluation demonstrated that 83% of the patients and 70% of the partners were satisfied with use of this device. Couples who reported the lowest levels of satisfaction were characterized by men who required more than 1 procedure for prosthesis implantation. Pain and appearance of the penis were the most common causes for dissatisfaction with the device. Results from this evaluation recognize the importance of careful surgical technique to avoid any surgical complications but, more importantly, they emphasize the need for physician-manufacturer interaction to maximize mechanical reliability of the prosthesis.

Erectile Dysfunction↗
PubMed1992

Artificial bladder replacement: a new design concept [see comment].

An effectively functioning artificial bladder would be useful after cystectomy because of the ease of insertion and the availability to all patients. In this report, we describe a new design concept based on negative pressure drainage of the kidneys and active voiding, and we present the results of testing this device. Although previous prosthetic bladders have had difficulties with renal failure from hydronephrosis, infection from retention of urine, and encrustation of the luminal surface, the current artificial complete bladder system addresses these problems.

Humans↗
PubMed1992

Effect of external beam radiotherapy on prostatic carcinoma DNA content as measured by static image cytometry.

Static image cytometry was used to study the effect of radiotherapy on the DNA content of prostatic carcinoma. Feulgen-stained specimens from 50 patients before and after radiotherapy were examined. The DNA index increased significantly after treatment (p less than 0.03), and it occurred equally in those with low (less than 1.5) and high (greater than or equal to 1.5) indices. The level of the initial DNA index was significantly related to the rate of symptomatic progression (p less than 0.05). The initial change in and final DNA indices were not related to survival however. There was a significant increase in Gleason score (p = 0.001) and histological grade (p = 0.01) after irradiation and, when taken individually, the degree of change was related to survival in both, p = 0.05 and 0.004, respectively. As Gleason score, Mayo grade and clinical stage were not independent variables; none of them was related to survival when corrected for the other factors. Thus, DNA content or ploidy, as well as Mayo grade and Gleason score, increases in recurrent tumor after radiotherapy. This may be of importance when considering what treatment to use and how intensively the patients should be followed up.

Actuarial Analysis↗