PubMed Health⌕ Search

Biomedical subjects

M Brehmer

Publications and source records attributed to M Brehmer.

12 recordsLinked to original sources
PubMed2006

Pelvicaliceal biomodeling as an aid to achieving optimal access in percutaneous nephrolithotripsy.

PURPOSE: To investigate prospectively the benefits of three-dimensional stereolithographic biomodeling produced from CT data as an aid to achieving optimal access for percutaneous nephrolithotripsy (PCNL). PATIENTS AND METHODS: Eight patients with complex urinary calculi were selected. Multislice CT scans of the kidney in native and excretory phases were acquired with the patient in the prone position to simulate the position during surgery. Contiguous reconstructed slices were produced from the data volume. The data of interest were processed to transform them into a format acceptable for production of a biomodel. Exact plastic replicas of the pelvicaliceal system and the calculi were created and used for morphologic assessment, preoperative planning, patient education, and surgical navigation. RESULTS: The survey results were based on subjective opinions rather than objective data. The biomodels enhanced the ability to visualize a patient's unique anatomy before surgery. This aided the planning and rehearsal of endourologic procedures. CONCLUSION: Although this study is only a preliminary investigation, we postulate that biomodeling has the advantage of allowing imaging data to be displayed in a physical form. In difficult cases, this technique may improve treatment, operative planning, and communication with colleagues and patients. The limitations of the technology include the manufacturing time and cost, but more accurate puncture-site selection may reduce costs by saving operating time.

Adult↗
PubMed2003

Complications associated with percutaneous nephrolithotripsy: supra- versus subcostal access. A retrospective study.

PURPOSE: Percutaneous nephrolithotripsy is an essential procedure for treating complex urinary calculi. To achieve optimal access to a large and complicated stone, an upper calyx puncture is often preferable. However, when performing a puncture above the 12th rib there is risk of an increased number of complications. In this retrospective study, we assessed the kind and frequency of complications after sub- and supracostal punctures of the collecting system of the kidney. MATERIAL AND METHODS: Between 1996 and 2001, 85 patients were treated with percutaneous nephrolithotripsy. In 63 patients a subcostal track, below the 12th rib was established. Puncture was performed under ultrasonic or fluoroscopic guidance in 61 patients and CT-guided in 2 patients. In 17 patients a supracostal puncture, above the 12th rib, was performed under CT guidance and in 5 patients with US or fluoroscopic guidance. RESULT: The main difference regarding preoperative complications was the number of patients complaining of respiratory correlated pain, 7 (32%) in the supracostal puncture group compared with 3 (5%) in the subcostal puncture group. No significant difference regarding peroperative complications was found. Postoperatively, there were 2 major bleedings, one in each group, which had to be treated with arterial embolization. In the supracostal puncture group there were 2 patients with pleural effusion and 2 patients with pneumothorax. CONCLUSION: The complication rate was slightly higher after supracostal puncture as compared with a subcostal approach, especially regarding respiratory correlated pain. When performing a supracostal puncture there is an increased risk that the track passes through the pleural space, which might explain the difference in the panorama of complications.

Fluoroscopy↗
PubMed2000

[Tough working conditions for urologists].

A questionnaire sent by the Swedish Association of Urology to all active Swedish urologists (n = 249) was returned by 89%. Questions concerned actual urological work, emergency duties, education, development facilities and research access, but also job satisfaction, psychological fatigue and emotional stress, as well as each urologist's plans for the future. Answers indicate that Swedish urologists carry a heavy work load and experience considerable demands from patients, relatives and colleagues. Physical and psychological exhaustion are common, and many hope to find work outside hospitals or abroad. The tightening of health-care purses presumably augments the work load, but local factors are also involved. For the future, more and improved educational programs are planned, together with greater participation on the part of junior doctors in organizational and structural processes. Compared to other physicians, urologists show greater reserves of psychic energy, but also signs of increasing intellectual exhaustion.

Adult↗
PubMed2000

Heat-induced apoptosis in human prostatic stromal cells.

OBJECTIVE: To determine whether heat, used in transurethral microwave thermotherapy (TUMT) for benign prostatic hyperplasia and which causes necrotic lesions within the adenoma, induces apoptosis in benign human prostatic stromal cells. Materials and methods Prostatic stromal cells were cultured from benign human prostatic tissue. The origin of the cells was identified by immunohistochemical staining and transmission electron microscopy. Cell cultures were exposed to moderate hyperthermia (47 degrees C) for 1 h and any apoptosis detected by light microscopy, transmission electron microscopy and the measurement of induced caspase-3-like activity. RESULTS: The cultures contained a mixed population of smooth muscle cells and myofibroblasts. Twenty-four hours after heat exposure, 76% of the cells were apoptotic and the caspase activity had increased, whereas only 14% of the cells were necrotic. CONCLUSION: Moderate hyperthermia induces apoptosis in cultured human prostatic stromal cells.

Apoptosis↗
PubMed2000

Elevation of sensory thresholds in the prostatic urethra after microwave thermotherapy.

OBJECTIVES: To determine whether transurethral microwave thermotherapy (TUMT) affects the sensory threshold in the posterior urethra and whether such an effect influences urinary storage symptoms. PATIENTS AND METHODS: The sensory threshold was measured before and at 3 and 12 weeks after TUMT in 13 men with minor obstructive symptoms caused by benign prostatic hyperplasia. Sensations were evoked by electrical stimulation at different frequencies, using a bipolar ring-electrode mounted on a urethral catheter. Changes in sensory thresholds were evaluated in the patients both as a group and individually. The patients were interviewed about their symptoms at each measurement. RESULTS: After TUMT, 12 patients were satisfied and reported decreased irritative symptoms, primarily less frequent nocturnal micturition; two patients were cured of urgency incontinence. In 11 of the satisfied patients, and the unsuccessful patient, decreased urge accompanied increased sensory thresholds. Thresholds elevated by >/= 30% were correlated with decreased irritative symptoms. CONCLUSIONS: TUMT decreases sensitivity in the posterior urethra, which may alleviate storage symptoms.

Electric Stimulation↗
PubMed2000

Denervation of periurethral prostatic tissue by transurethral microwave thermotherapy.

PURPOSE: To determine whether transurethral microwave thermotherapy (TUMT) affects innervation of the urethra and periurethral prostate. MATERIAL AND METHODS: Ten patients with troublesome benign prostatic hyperplasia (BPH) were treated with TUMT 1 week prior to transurethral resection of the prostate (TURP). At surgery, a biopsy was taken for histological examination and for immunohistochemical staining of the non-specific neuromarker protein gene product (PGP) 9.5. Control material consisted of identical biopsies from 10 patients undergoing TURP because of BPH, but not subjected to TUMT prior to surgery. RESULTS: Histological examination revealed well-preserved, non-necrotic tissues in all biopsies. Nerve fibres were completely or almost absent in the smooth muscle layer in all but one of the TUMT cases, whereas all non-TUMT patients exhibited large numbers of nerve fibres in the smooth muscle layer. CONCLUSIONS: TUMT does affect innervation of the urethra and periurethral prostatic tissue.

Aged↗
PubMed2000

Transurethral microwave thermotherapy: how does it work?

Although some authors have proposed that the favorable impact of transurethral microwave thermotherapy (TUMT) for benign prostatic hyperplasia has only a placebo effect, this idea is inconsistent with the findings of a number of sham-controlled clinical trials. Histologic and immunohistochemical studies have shown that the nerve fibers in the periurethral tissue are damaged or ablated by TUMT, and it appears that the heat affects the innervation of the smooth muscle cells. Among the nerves damaged are the sensory neurons of the posterior urethra, and this change might reduce the excitatory signals from the urethrodetrusor facilitating reflexes. Necrosis and apoptosis within a limited area also have been described. Thus, there is likely more than one basis for the therapeutic effect of TUMT.

Humans↗
PubMed1999

Sham treatment compared with 30 or 60 min of thermotherapy for benign prostatic hyperplasia: a randomized study.

OBJECTIVE: To study the differences in subjective and objective results after 30 or 60 min of transurethral thermotherapy (TUMT) or sham treatment in men with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Forty-four patients with lower urinary tract symptoms caused by BPH were randomized to undergo 30 or 60 min of TUMT or sham treatment (14, 16 and 14 patients, respectively). The patients were evaluated using symptom scores, timed micturition, free flow rates and urodynamics before and after treatment. They were followed for 1 year, at the end of which they rated the treatment results on a self-administered visual analogue scale. RESULTS: Forty-two patients completed the study. The treatment failed in some patients in all groups, but the improvement in maximum and median flow rates, timed micturition and micturition frequency (day and night) was greater after TUMT than in the sham-treated group. Symptom scores also improved more after TUMT, although not significantly. There was a good correlation between the decrease in urinary frequency, especially nocturnal, and the patients' perception of a successful treatment, whereas the increase in maximum urinary flow rate was apparently of little importance. CONCLUSIONS: TUMT had a better effect than the placebo treatment, having a greater impact on irritative than on obstructive symptoms. More patients were satisfied after the 30-min than after the 60-min treatment.

Aged↗
PubMed1997

Morphological changes in prostatic adenomas after transurethral microwave thermotherapy.

OBJECTIVE: To study the extension and type of tissue damage in prostatic adenomas after transurethral microwave thermotherapy (TUMT). PATIENTS AND METHODS: Seven patients with benign prostatic hyperplasia and scheduled for open adenectomy underwent TUMT before surgery. TUMT was performed 2 h before operation in one patient, 24 h before in five and one week before in the remaining patient. The excised adenomas were examined by routine light microscopy. In addition, the terminal deoxynucleotidyl nick-end labelling (TUNEL) technique was used to search for DNA-strand breaks in areas with morphological alterations suggestive of apoptosis. Due to technical problems, TUMT was inadequate for one patient, i.e. the effect given was extremely low. RESULTS: In six cases, histopathological changes were found in limited areas extending from the urethra for 20-25 mm into the prostatic tissue. The predominant histopathological findings were areas of necrosis surrounded by cells with apoptotic features. The latter proved to be TUNEL-positive, i.e. they contained nuclei with DNA fragmentation of the apoptotic type. In the case with inadequate TUMT, there was no heat-induced tissue damage. CONCLUSION: The area of tissue damage seen after TUMT was relatively small compared with the volume of the prostates. The main histopathological finding was massive necrosis, but cells undergoing apoptosis were also identified. Obviously, temperatures lower than those leading to necrosis induced apoptosis, which is a discrete type of cell death not associated with oedema or inflammatory reaction.

Apoptosis↗
PubMed1996

Transurethral microwave thermotherapy for benign prostatic hyperplasia. Subjective response and urodynamic changes.

Results of transurethral microwave thermotherapy for benign prostatic hyperplasia were good after 1 year in 68% of 66 cases. Despite good correlation between subjective assessment of results and improvement in urodynamic parameters, no predictive factors for probably successful outcome could be identified. Diminution in frequency of micturition (diurnal from 8.8 to 6.8 times, nocturnal from 3.0 to 1.6 times), increased flow rates (Q max from 8.8 to 14.2 ml/s) and reduction of detrusor pressures during voiding (Pdet max from 86.9 to 75.0 cm H2O) were significant, but the change in residual volume (from 52 to 37 ml) was of lesser degree (all mean values). Transurethral microwave thermotherapy can be tried for relief of moderate obstruction when transurethral prostatic resection involves risk, or the patient himself requests noninvasive treatment.

Aged↗
PubMed1994

Iodine-125 brachytherapy for clinically localized prostate cancer: a 5-year follow-up of outcome and complications.

Thirty-seven patients with clinically localized prostate cancer of all grades were treated by suprapubic digitally guided implantation of 125I seeds. The median age at the time of diagnosis was 68 years. The mean follow-up period was 62 +/- 19 months. At last follow-up 18 patients were clinically free of disease; 11 deaths occurred: 9 from prostate cancer and 2 from another disease. Complications occurred in 24 patients most commonly urgency and proctitis, attributable to the treatment. Four patients had severe late rectal complications, and 2 patients died of sepsis secondary to rectal fistulae. Digitally directed retropubic implantation of 125I appears inferior to other treatments of clinically confined prostate cancer both regarding outcome as well as complication rate.

Aged↗