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Biomedical subjects

T A Boon

Publications and source records attributed to T A Boon.

At least 19 recordsLinked to original sources
PubMed1998

Recovery of storage and emptying functions of the urinary bladder after spinal anesthesia with lidocaine and with bupivacaine in men.

BACKGROUND: The aim of this study was to evaluate and compare the effects of spinal anesthesia with lidocaine and with bupivacaine on urinary bladder function in healthy men who were scheduled for minor orthopaedic surgical procedures. METHODS: Twenty men were randomly allocated to receive either bupivacaine or lidocaine. Before spinal anesthesia, filling cystometry was performed with the patient in the supine position and a pressure flow study was done with the patient in the standing position. After operation, cystometric measurements were continued until the patient could void urine spontaneously. The levels of analgesia and of motor blockade were recorded. RESULTS: The urge to void disappeared immediately after injection of the local anesthetics. There was no difference in the duration of lower extremity motor blockade between bupivacaine and lidocaine. Detrusor blockade lasted significantly longer in the bupivacaine group (means +/- SD, 460 +/- 60 min) than in the lidocaine group (235 +/- 30 min). Total fluid intake and urine volume accumulated during the detrusor blockade were significantly higher in the bupivacaine group than in the lidocaine group. In the bupivacaine group, the total volume of accumulated urine (875 +/- 385 ml) was also significantly higher than cystometric bladder capacity (505 +/- 120 ml) with the risk of over distension of the bladder. Spontaneous voiding of urine did not occur until segmental sensory analgesia had regressed to the third sacral segment. CONCLUSIONS: Spinal anesthesia with lidocaine and with bupivacaine causes a clinically significant disturbance of bladder function due to interruption of the micturition reflex. The urge to void disappears quickly and bladder function remains impaired until the block has regressed to the third sacral segment in all patients. With long-acting local anesthetics, the volume of accumulated urine may exceed the cystometric bladder capacity. With respect to recovery of urinary bladder function, the use of short-acting local anesthetics for spinal anesthesia seems to be preferable.

Adult↗
PubMed1998

Intravesical interleukin-2 in T1 papillary bladder carcinoma: regression of marker lesion in 8 of 10 patients.

PURPOSE: We evaluate the therapeutic effect of intravesical interleukin-2 (IL-2) on T1 papillary bladder carcinoma after incomplete transurethral resection. MATERIALS AND METHODS: After incomplete transurethral resection we treated 10 patients in whom the marker lesion was left in place with 3 x 10(6) Chiron units IL-2 in 50 ml. saline plus 0.1% human serum albumin. The solution remained in the bladder for 2 hours and it was instilled on 5 consecutive days. The effect of IL-2 treatment on the marker lesion was evaluated by cystoscopy and repeat biopsy of the marker site 2 months after treatment. In addition, the effect on the recurrence of bladder tumors was studied. RESULTS: At 2 months 8 of the 10 marker lesions (80%) had completely regressed and there were no tumor cells on repeat biopsy. Four patients remained tumor-free after 30 to 54 months. We noted no toxic effects. In 1 patient with a 7-year history of bladder cancer the marker was only partially regressed after 2 months. After removal of the marker this patient remained tumor-free at a followup of 54 months. CONCLUSIONS: To our knowledge this report represents the first study of the effect of IL-2 on marker lesions left in place after transurethral resection. The results indicate that IL-2 instillations are feasible, and the combination of transurethral resection and IL-2 instillation may have a powerful antitumor effect. The therapeutic effects may not simply be due to intravesical IL-2, because previous transurethral resection probably caused some influx of infiltrating cells and the marker may have had tumor associated antigens. Consequently these effects may be due to the interaction of tumor associated antigens, infiltrating cells and IL-2.

Administration, Intravesical↗
PubMed1997

Combined hormono/chemotherapy as primary treatment for metastatic prostate cancer: a randomized, multicenter study of orchiectomy alone versus orchiectomy plus estramustine phosphate. The Dutch Estracyt Study Group.

OBJECTIVES: Based on the theory that hormone-resistant cells are present in all metastatic patients, early administration of chemotherapy appears to be logical and its use is supported by experimental studies. Therefore, trials with combined hormonal and cytotoxic treatment as primary therapy should be conducted. In the present trial, the efficacy and tolerance of estramustine phosphate (EMP) as a chemotherapeutic agent in addition to hormonal treatment (orchiectomy) was studied in patients with metastatic and nonmetastatic prostate cancer not previously treated. EMP was chosen because it produces few serious adverse reactions and no cumulative toxicity. METHODS: Four hundred nineteen patients were included in a 1.5-year period starting in January 1989. Patients with locally advanced prostate cancer or with bone metastases were randomized to orchiectomy (O) or orchiectomy followed by EMP (O + E), given until progression. RESULTS: Analysis of the total group showed no significant difference in time to progression between the treatment groups. Because the course of the disease is different in patients with either T4 tumor only or with lymph node metastases only (M0) as compared with patients with bone metastases (M1) and because the number of progressions in the M0 patients was low, corresponding analyses were performed for these subgroups as well. In the M1 patients, there was a tendency for a longer time to progression in the O + E group than in the O group, but there was no indication of a difference between the groups with regard to survival. In the M0 patients, there was no indication of any difference in results between the treatments. Multivariate analysis of prognostic factors showed pain, alkaline phosphatase, metastasis status, and tumor stage to be significant factors. There was a relation between age and drug treatment in that a significant beneficial effect of EMP in terms of prolonged progression-free interval as well as survival was evident in younger patients (aged less than 73 years) with metastatic disease. Tumor stage was also of importance for the drug effect; T0 to T3 patients who received EMP survived longer than those who were treated with orchiectomy only. The most common adverse reaction was nausea in the O + E group, which led to discontinuation of the drug in 7 patients. Cardiovascular problems are not uncommon in this age group, and there was a higher incidence of cardiovascular events, predominantly cardiac failure, in the O + E group, leading to treatment interruption in 16 patients. CONCLUSIONS: Our results indicate that future studies of hormono/chemotherapy should focus on younger patients with bone metastases.

Aged↗
PubMed1996

Variation in output power of laser prostatectomy fibers: a need for power measurements.

OBJECTIVES: The aim of this study was the assessment of the quality of side-firing fibers that are being used for laser prostatectomy, either by a laser light transmission measurement or by visual inspection. METHODS: A power meter (Aquarius) was developed to measure the actual power transmitted through a side-firing fiber and delivered to the prostatic tissue. The power measurements were performed under clinical conditions, that is, under water and at relatively high input power. Furthermore, a protocol was developed for visual inspection of the fibers. Eight types of side-firing fibers were measured before use. Before and after a procedure, three fiber types were measured: ProLase II (28 samples), UltraLine (23 samples), and UroLase (44 samples). All these fibers were used in standard treatment protocols. RESULTS: At 60 W the transmission of new fibers (not used) ranged between 49% and 83% when compared to a bare fiber. After use, a large variation was found in transmitted power between different samples of one device. A correlation with total transmitted power was not present. At higher power input, vapor bubbles are generated at the tip of the fibers. Depending on the fiber design, these bubbles have a major impact on the transmission. Only for the UroLase fiber was there a significant correlation between visual inspection and the transmission of used samples at 10, 20, and 40 W. CONCLUSIONS: The transmission strongly varies between fibers and between different samples of one fiber during clinical use. Moreover, the transmission does not correlate with visual inspection. A power measurement during a clinical treatment will contribute to a more controlled procedure and to a better comparison of clinical laser prostatectomy studies.

Biophysical Phenomena↗
PubMed1996

The value of symptom score, quality of life score, maximal urinary flow rate, residual volume and prostate size for the diagnosis of obstructive benign prostatic hyperplasia: a urodynamic analysis.

PURPOSE: We investigated which linear combination of scores for symptoms, quality of life, maximum urinary flow rate, residual volume and prostate size best discriminated men with prostatism who do and do not have obstruction. MATERIALS AND METHODS: Mandatory and recommended tests were performed in 196 men older than 50 years with prostatism. Schäfer's obstruction grade was estimated by urodynamic studies. Relative residual volume was defined as residual volume divided by cystometric capacity (times 100%). Correlation coefficients among the different parameters were estimated. Obstruction grade was correlated with linear weighted combinations of the parameters. RESULTS: Of the men 79% appeared to have obstruction. The formula, prostate size (cm.3) -3 x maximum urinary flow rate (ml. per second) + 1/4 of relative residual volume (%), correlated almost maximally with obstruction grade. Including quality of life score or symptom score in this expression had a negative outcome on the correlation. Calculation of this expression resulted in the bladder outlet obstruction number. In more than 50% of the men the bladder outlet obstruction number was greater than -2 and more than 90% had obstruction. In 25% of all men the bladder outlet obstruction number was greater than 13 and more than 95% had obstruction. CONCLUSIONS: Bladder outlet obstruction number may be calculated with an easy to use expression composed of prostate size, maximum urinary flow and relative residual volume. In 50% of the men with prostatism bladder outlet obstruction number will diagnose obstruction with a reliability of more than 90%.

Aged↗
PubMed1996

Transurethral marsupialization of a medial prostatic cyst in patients with prostatitis-like symptoms.

PURPOSE: The results of transurethral marsupialization as treatment for medial prostatic cysts were assessed. MATERIALS AND METHODS: Between June 1992 and August 1994 we performed transrectal ultrasound on 704 patients with symptoms of bladder outlet obstruction or lower urinary tract symptoms and a medical prostatic cyst was found in 34 (5%). Transurethral marsupialization of the cyst via incision of the prostatic floor under transrectal ultrasound guidance was performed in 18 patients. Followup was 12 to 25 months (mean 18). RESULTS: Patients with a medial prostatic cyst complained of prostatitis-like symptoms (77%), scrotal pain (62%), impaired micturition (32%), small volume ejaculation (35%), painful ejaculation (24%), hemospermia (24%) and infertility (12%). After marsupialization of the cyst, symptoms resolved completely in 14 patients (78%), improved in 17 (94%) and did not improve in only 1 (6%). No complications of this procedure were noted. The 16 patients who did not undergo surgery still complain of prostatitis-like symptoms without evidence of bacterial prostatitis. CONCLUSIONS: We believe that a medial prostatic cyst can cause prostatitis-like symptoms and that marsupialization of the cyst can provide symptom relief in the majority of patients.

Adult↗
PubMed1995

Side-firing devices for laser prostatectomy. An overview.

Transurethral laser coagulation of the prostate has become an accepted treatment for benign prostatic hyperplasia (BPH). The most common method is the use of a sideward-firing fiber that, once inserted in the prostatic area, irradiates the abundant prostatic tissue with Nd:YAG laser light. In this study, eight different side-firing fibers that are commercially available were evaluated. The devices can be characterized by the way laser light is deflected sideward and by their thermal behavior. Most of the eight devices differ with regard to the angle at which the laser beam is deflected, the spot size on the irradiated tissue surface, and the heating of the device itself. Implementation of the optical and thermal characteristics of each device in the treatment protocol will contribute to the optimal use of laser energy for prostatectomy.

Equipment Design↗
PubMed1995

Laser prostatectomy for patients with benign prostatic hyperplasia: a prospective randomized study comparing two different techniques using the Prolase-II fiber.

Laser prostatectomy for patients with complaints due to benign prostatic hyperplasia is a relatively new treatment option. The most effective procedure for coagulation and vaporization of the prostate is not yet known. In a prospective randomized study of 30 patients, 2 techniques for the delivery of laser energy were compared at 40 W for 90 s. The complications were minimal and antegrade ejaculation was preserved in 15 of 18 potent men. In 24 patients urodynamics evaluation was possible. In both groups a significant reduction in the symptom score was observed. The decrease in detrusor pressure at maximal flow and the increase in flow rate were, however, disappointing. No significant difference in the results was found between the two groups. The power setting needs to be changed in further studies.

Aged↗
PubMed1995

International prostate symptom score and quality of life assessment versus urodynamic parameters in men with benign prostatic hyperplasia symptoms.

In 207 men with symptomatic benign prostatic hyperplasia the international prostate symptom score and score on quality of life were collected. Cystometric tests with pressure-flow studies were performed in these patients with special attention to the assessment of obstruction grade. Of the men 24% appeared not to have obstruction. A significant correlation was found between size of the prostate and grade of obstruction. No correlation was found between obstruction grade, and any symptom score or quality of life score, while symptom score and quality of life correlated well. In 41 patients the outcome of laser prostatectomy was evaluated 6 months after the procedure. Mean symptom score decreased from 19.1 to 5.4 and mean quality of life score decreased from 3.7 to 1.3 in the 31 obstruction patients, compared to decreases of 19.6 to 10.1 and 3.6 to 2.6, respectively, in 10 without obstruction. The improvement in the obstruction patients was significantly better but nonobstruction patients will benefit from prostatectomy as well.

Aged↗
PubMed1994

[Laser prostatectomy as alternative to transurethral prostate resection in benign prostatic hyperplasia].

OBJECTIVE: Assessment of the results of laser prostatectomy, as a treatment for benign prostatic hyperplasia (BPH). DESIGN: Prospective case control study. SETTING: University Hospital Utrecht, the Netherlands. METHOD: Between February 1992 and May 1993, 54 men with their micturition complaints due to BPH were treated with laser prostatectomy (TULIP system). Results were assessed using the international prostatic symptom score (IPSS), the maximal flow and urodynamic tests. The results were compared retrospectively with results of transurethral resection of the prostate (TURP; n = 40): both groups were urodynamically identical. RESULTS: Of the 54 patients, 10 could not be evaluated 6 months after treatment (5 of them underwent TURP or a second laser prostatectomy). In 40 patients complete evaluation including urodynamics before and six months after treatment was possible. A significant decrease in the symptom score from 19.3 (SD: 7.6) to 6.3 (SD: 5.4) and increase of the maximal flow during pressure-flow studies from 9.6 to 15.8 ml per second were observed. The decrease of the voiding pressure at 6 months after TURP in comparison with laser prostatectomy was close to significance (p = 0.05); the other improvements after urodynamics were comparable. CONCLUSION: Laser prostatectomy is a promising new therapy for BPH.

Aged↗
PubMed1994

Extensive urodynamic investigation: interaction among diuresis, detrusor instability, urethral relaxation, incontinence and complaints in women with a history of urge incontinence.

In 72 women with a clinical history of frequency and/or urge incontinence and in whom during filling cystometry nearly no abnormalities were detected, cystometry was repeated not by transurethral filling but under high diuretic conditions (diuresis cystometry). The prevalence and strength of detrusor instability, and the prevalence of incontinence were significantly greater during diuresis cystometry compared to filling cystometry. The experiences of these patients during episodes of instability were similar to those in their own daily environment. Most women with motor urge incontinence on filling or diuresis cystometry are losing urine at detrusor pressures lower than would be expected from urethral closure pressure measurements at rest. Therefore, urethral relaxation may have an important role in the etiology of incontinence. Apparent low amplitude detrusor instability may cause severe incontinence when combined with urethral relaxation. Extensive urodynamic investigations (including diuresis cystometry) will improve the clinical applicability of urodynamics.

Adult↗
PubMed1994

Optimization of laser prostatectomy.

A recent development in the treatment of Benign Prostatic Hyperplasia (BPH) is the use of a side firing fiber device coupled with a Nd:YAG laser. In this study, a numerical and an in-vitro model were developed to calculate and visualize the temperature distribution and the associated tissue necrosis due to irradiation of the prostate with Nd:YAG laser light. Different irradiation modalities were included: a static beam, with the irradiating fiber remaining at one place and a moving beam, with the fiber scanning over the surface at different speeds. Also blood vessels were incorporated in the model and showed to have major influence on the resulting tissue necrosis.

Computer Simulation↗
PubMed1993

[Sexual possibilities following total penis amputation].

A male aged 45 was subjected to total penis amputation because of a penile carcinoma; a perineal urethral stoma was created. The postoperative course was uneventful. One month after the last operation the patient for the first time felt the need for sexual contact, but his wife hesitated. After medical-sexological counselling, the partners achieved satisfactory sexual functioning with the husband occasionally having an orgasm.

Amputation, Surgical↗