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Biomedical subjects

H Strasser

Publications and source records attributed to H Strasser.

At least 19 recordsLinked to original sources
PubMed2004

Three-dimensional transrectal ultrasound of the male urethral rhabdosphincter.

The rhabdosphincter of the male urethra is an omega-shaped loop of striated muscle fibers that surrounds the membranous urethra at its lateral and anterior aspects. We investigated whether this muscle can be visualized by means of three-dimensional ultrasound to define morphological and dynamic ultrasound criteria. We examined the rhabdosphincter of the male urethra in 77 patients by means of this new imaging technique; 37 patients presented with urinary stress incontinence after transurethral resection of the prostate or radical prostatectomy while 40 were fully continent after radical prostatectomy and served as a control group. Contractility of the muscle was quantified by a specially defined parameter (rhabdosphincter-urethra distance). The anatomical arrangement and the contractions of the rhabdosphincter-loop could be clearly visualized in three-dimensional transrectal and transurethral ultrasound; during contraction the rhabdosphincter retracts the urethra, pulling it towards the rectum. We detected defects and postoperative scarrings in the majority of the patients with postoperative urinary stress incontinence. Furthermore, the patients presented with thinnings in parts of the muscle and atrophies of the rhabdosphincter. The rhabdosphincter-urethra distance was significantly lower in the incontinent group than in the continent group (59 vs. 1.42 mm). Our study shows that the rhabdosphincter of the male urethra can be visualized by means of three-dimensional transrectal ultrasound. The sonographic pathomorphological findings of postoperative urinary stress incontinence are well correlated well with the clinical symptoms.

Humans↗
PubMed2004

[Anatomic basis for the innervation of the male pelvis].

To reach an optimal outcome after radical prostatectomy or cystoprostatectomy, minimal bleeding from the dorsal vein complex, meticulous apical dissection without distraction of the rhabosphincter and preservation of the cavernous nerves are necessary.A total of 19 male cadavers were used, ranging in age from 52-78 years and including 8 fetuses. Fourteen complete pelves and five tissue blocks of prostate, rectum, membranous urethra and the rhabdosphincter were investigated. Besides anatomical preparations, the lower urinary tract was studied by means of serial histological sections. The cavernous nerves and the pudendal nerves as well as their branches were dissected. For this reason, the pubic symphysis was severed. Subsequently the right or left hip bone was removed, whereas the pelvic organs were left intact to achieve a complete exposure of the lower urinary tract and the pudendal nerves. The rhabdosphincter presents as a vertical structure extending from the bulb of the penis to the region of the bladder neck along the prostate and the membranous urethra. It is supplied by branches of the pudendal nerve after leaving the pudendal canal. The membranous urethra is innervated by branches of the autonomic pelvic plexus. The nervous branches that are responsible for erection travel along the lateral aspects of the prostate in the so called "neurovascular bundle" and traverse through the urogenital hiatus to reach the corpora cavernosa.

Aged↗
PubMed2004

[Advantages of nerve-sparing pelvic surgery. Animal experiments and clinical results].

Traditionally, oncological factors have been the only ones used in the evaluation of treatment outcome for urological tumor patients. With increased diagnoses of early, curable tumors in younger individuals, health-related quality of life and functional aspects are gaining importance. Sexual and urinary function are significant aspects of quality of life, which are especially vulnerable in urological patients. New insights into the anatomy and physiology of the pelvic organs have resulted in an improvement in surgical therapy. In this article, we present the results of current experimental and clinical studies, which underline the importance of nerve sparing techniques for maintaining a satisfying urinary and sexual function in this patient population.

Animals↗
PubMed2004

[Stem cell therapy for urinary incontinence].

Experimental and clinical studies investigated whether urinary incontinence can be effectively treated with transurethral ultrasound-guided injections of autologous myoblasts and fibroblasts.This new therapy was performed in eight female pigs. It could be shown that the injected cells survived well and that new muscle tissue was formed. Next, 42 patients (29 women, 13 men) suffering from urinary stress incontinence were treated. The fibroblasts were mixed with a small amount of collagen as carrier material and injected into the urethral submucosa to treat atrophies of the mucosa. The myoblasts were directly injected into the rhabdosphincter to reconstruct the muscle and to heal morphological and functional defects. In 35 patients urinary incontinence could be completely cured. In seven patients who had undergone multiple surgical procedures and radiotherapy urinary incontinence improved. No side effects or complications were encountered postoperatively. The experimental as well as the clinical data clearly demonstrate that urinary incontinence can be treated effectively with autologous stem cells. The present data support the conclusion that this new therapeutic concept may represent a very promising treatment modality in the future.

Adult↗
PubMed2004

[Transrectal three dimensional sonography. Techniques and indications].

In 3-D transrectal ultrasound it is possible, for the first time, to investigate the region of interest in three planes simultaneously. Exact examination of the organs of the small pelvis as well as of pathologic changes in the region of the pelvic floor can be performed with this new imaging technique. The bulbourethral glands can be investigated routinely, which enables the diagnosis of cysts of these glands. The prostatic zones, their relations as well as the growth of the transitional zone during the development of benign prostatic hyperplasia can be visualized. Furthermore, 3-D transrectal ultrasound allows investigation of morphology and function of the rhabdosphincter. The contractility of the muscle can be quantified. 3-D ultrasound guided puncture and drainage of prostatic abscesses represents a minimally invasive therapeutic modality. This technique can be used to place needles as well as implants in the lower urinary tract. Generally, 3-D transrectal ultrasound offers new diagnostic and therapeutic possibilities.

Animals↗
PubMed2004

Late urologic effects after adjuvant irradiation in stage I endometrial carcinoma.

OBJECTIVES: To evaluate the incidence and type of incontinence after external beam radiotherapy (RT) and brachytherapy. Distinct late effects on the urinary bladder can occur and are frequently mild after adjuvant RT for Stage I endometrial carcinoma. Not all side effects that impair quality of life (eg, urinary incontinence) are classified in the commonly used grading system. METHODS: Forty-one patients were evaluated for newly occurred urinary incontinence after adjuvant RT. The mean follow-up was 64.8 months, and the mean age was 62.1 years. The validated incontinence score from Gaudenz was used. Additionally, quality-of-life questions were asked. RESULTS: Overall, 22 (53.7%) of 41 patients complained of urinary incontinence. Urge incontinence was classified in 45.5% (10 of 22 patients) and stress urinary incontinence in 54.5% (12 of 22 patients). CONCLUSIONS: The onset of stress urinary incontinence after brachytherapy can be explained by anatomic findings, such as adverse affects to the nerve supply of the rhabdosphincter. According to our results, the exposure to additional external beam RT can cause urge incontinence. Patients and doctors must be aware that urinary incontinence, with an occurrence rate of more than 50%, represents the most common side effect after surgery and RT for Stage I endometrial carcinoma. We conclude that, depending on the type of RT, a stress incontinence rate of 24.4% and an urge incontinence rate of 29.2% is possible.

Adenocarcinoma↗
PubMed2001

Human rhabdosphincter cell culture: a model for videomicroscopy of cell contractions.

BACKGROUND: Physiology of the human rhabdosphincter and its innervation are still a subject to controversy. A better understanding of rhabdosphincter function and anatomy might help to solve important urological problems like urinary incontinence. It was the aim of the present study to develop a human sphincter cell culture model for investigation of contraction mechanisms in vitro. METHODS AND RESULTS Cells were isolated from human rhabdosphincter tissue obtained from prostatectomy and cystoprostatectomy specimens. Cultured cells expressed typical features of striated muscle cells. By means of videomicroscopy with a time lapse videosystem cell contractions could be documented. Under control conditions without any contractile stimulant 8% of the cells were seen to contract. Cholinergic stimulation with 10 mM of acetylcholine induced a significant increase in contraction rate to 49%. CONCLUSIONS: These results demonstrate that cholinergic stimulation triggers contraction of cultured human rhabdosphincter cells. This model might help to understand external urethral sphincter physiology and to establish new therapies for the treatment of sphincter dysfunctions. Prostate 47:189-193, 2001.

Cell Culture Techniques↗
PubMed2001

VI--choosing the right reconstruction for your female patients.

Like in male patients, selection of female patients for an orthotopic neobladder is important from an oncological and functional standpoint. The anatomy and the behavior of the isolated urethra in women had to be restudied because of the shorter urethra, the absence of the prostate, an undefined level of urethral dissection, and the different anatomy of the urethral sphincter-system. Retrospective long-term observations of female patients with primary bladder cancer revealed a 2% incidence of secondary urethral tumors in women. The only significant risk factor for urethral tumor involvement was primary bladder cancer at the bladder neck. Any type of gastrointestinal segment may be used for creating a pouch in women. As a result of an approximately 15% possibility of urinary retention or larger post-void residuals, the use of an efficient antireflux valve mechanism seems prudent. Clinical experience in an increasing number of women confirms the preliminary favorable results. Despite the selection criteria outlined in this article, most women can safely and rewardingly be offered an orthotopic neobladder.

Appendectomy↗
PubMed2001

Ureteroileal anastomosis in orthotopic urinary diversion: how much or how little is necessary?

PURPOSE: An increasing number of patients with an orthotopic neobladder and their expanding life expectancy necessitate an effective antireflux protection of the upper urinary tract. During the evolution of urinary diversion in the 20th century, several techniques to perform an ureteroileal anastomosis have been introduced. Those techniques most commonly used for orthotopic neobladders are discussed. MATERIALS AND METHODS: Vascularization of both the ureteral ends and the recipient bowel as well as a meticulous surgical technique are necessary to reduce the reported postoperative stricture rate, which ranges between 3% and 30%. Variations such as preservation of additional periureteral adventitial tissue and its use for coverage of the ureterointestinal suture line are described. High-pressure urinary reflux may lead to mechanical damage of the renal parenchyma, whereas low-pressure occasional reflux in conjunction with chronic bacteriuria will lead to pyelonephritic changes and eventually deterioration of renal function. An intraluminal valve mechanism with increasing efficiency during pouch filling is clearly the most physiological form of antireflux mechanism. Interposition of an afferent ileal limb in addition to the antireflux valve seems advantageous due to the favorable vascularization in the dissected midureter. CONCLUSIONS: Increased life expectancy in patients with orthotopic neobladders will increase the number of cases where access to the upper urinary tract becomes necessary due to a benign or malignant disease. Any technique that simultaneously provides an efficient antireflux mechanism and facilitates retrograde manipulation of the ureters (via the pouch) will be greatly appreciated by both patients and treating physicians.

Adult↗
PubMed2000

Anatomic and functional studies of the male and female urethral sphincter.

A total of 28 human specimens (14 male, 14 female) was used to perform macro- and microscopic studies on the morphologic basis of the urethral continence mechanism. Furthermore, functional studies were performed in six sheep, with the aim of looking at the pudendal and autonomic innervation of the urethra and the rhabdosphincter, as well as the changes of autonomic innervation after selective denervation. Transurethral ultrasound was performed in 34 continent patients, in order to visualize the contractions of the rhabdosphincter. The membranous urethra is innervated by branches of the autonomic pelvic plexus. The rhabdosphincter is an omega-shaped loop of striated muscle fibers that is innervated by the pudendal nerves. These results are supported by the results of animal experiments that show that the autonomic nerves predominantly innervate and regulate the upper part of the urethra, whereas stimulation of the pudendal nerves leads to a contraction of the lower part of the sheep urethra. In electron-microscopy, marked degeneration of the smooth muscle cells could be seen in the sheep with bilateral denervation.

Adult↗
PubMed2000

Reconstruction of the lower urinary tract using autologous muscle transfer and cell seeding: current status and future perspectives.

Functioning free-muscle transfer has established itself for the treatment of skeletal muscle deficiency over the last two decades. The capability of skeletal muscle to empty a spherical reservoir has been shown to be lessened if the muscle has contracted due to dissection. Currently there is no established curative treatment for bladder acontractility. Experimental data and preliminary clinical results have shown that innervated free latissimus dorsi muscle (LD) may serve as a substitute for a dysfunctional detrusor. In a clinical protocol, latissimus dorsi detrusor myoplasty (LDDM) was applied in 11 patients (age 9-68 years) with bladder acontractility due to spinal cord injury (seven patients), congenital malformations (two patients), detrusor myopathy (one patient), and idiopathic causes (one patient) who had required catheterization for bladder emptying for a minimum of 2 years. In all, 10 of 11 patients were capable of voiding volitionally, with eight of them no longer requiring catheterization, throughout the follow-up period of 12-46 months. Transplanted LD activity was confirmed by ultrasonography and flow-mode computerized tomography. It can thus be concluded that emptying of the bladder can be induced through the contractility of reinnervated free LD that has been wrapped around the bladder. An innervated free-LD flap does not undergo the severe muscle fibrosis, contracture, and atrophy that occur after transfer of completely or partially denervated pedicled muscle. Apart from the restoration of deficient detrusor function, microneurovascular transfer of a free-LD flap may be combined with tissue engineering to serve as a basis for bladder augmentation and substitution.

Adolescent↗
PubMed2000

Evidence for the autoregulation of vesical circulation by intravesical potassium chloride and distension in the normal human bladder.

OBJECTIVES: To determine the influence of distension and intravesical KCl on vesical blood flow in the normal human bladder. Subjects and methods Nine normal volunteers underwent comparative cystometry (NaCl vs 0.2 mol/L KCl; filling rate 50 mL/min). Peak systolic blood flow velocity (PSBFV) and end-diastolic blood flow velocity (EDBFV) were measured in several intramural arteries at a filling volume of 50 mL and at maximum cystometric capacity (Cmax). For these measurements a colour Doppler unit fitted with an endorectal probe was used. The resistance index (RI) was defined as (PSBFV-EDBFV)/PSBFV. RESULTS: In the presence of NaCl, the mean PSBFV increased significantly from 9 cm/s at 50 mL to 17 cm/s at Cmax (512 mL). Compared with NaCl, KCl induced a significantly higher mean PSBFV at 50 mL (15 cm/s). With increasing distension the rise in PSBFV with KCl filling (Cmax 478 mL) was nearly parallel to that obtained on NaCl filling (mean 22 cm/s); the RI did not change. CONCLUSIONS: Bladder distension and intravesical KCl significantly increased the PSBFV. The unchanged RI indicated a concomitant increase in perfusion rates. Hence, the composition of urine (high potassium concentrations and hyperosmolarity) and its storage govern the autoregulation (independent of cardiac output) of vesical circulation, probably by reflexive pathways. These findings provide further evidence for prevesical arteriovenous shunts.

Blood Flow Velocity↗
PubMed2000

Anatomy and innervation of the rhabdosphincter of the male urethra.

The rhabdosphincter of the male urethra and its innervation are still a subject of controversy. Essentially, two concepts of its anatomy can be found in the literature. Some authors describe the rhabdosphincter as part of the urogenital diaphragm caudal to the prostate, others as a striated muscle that extends from the base of the bladder to the "urogenital diaphragm." In anatomic histological studies, the rhabdosphincter and its innervation were examined by means of anatomical dissections and serial anatomical as well as histological sections of 19 male pelves, including 8 fetal specimens. The rhabdosphincter presents as a vertical structure extending from the bulb of the penis to the region of the bladder neck along the prostate and the membranous urethra. Inserting dorsally in the perineal body via a broad tendinous raphe, the striated muscle fibers form an omega-shaped loop around the anterior and lateral aspects of the membranous urethra. The existence of a "urogenital diaphragm" and a strong, circular, striated "external sphincter urethrae" completely encircling the urethra caudal to the apex of the prostate cannot be confirmed by anatomical and histological investigations. The rhabdosphincter is supplied by branches of the pudendal nerve after leaving the pudendal canal.

Age Factors↗
PubMed2000

Age dependent apoptosis and loss of rhabdosphincter cells.

PURPOSE: To our knowledge the exact age dependent morphological and functional changes of the sphincter mechanism have not been investigated. Therefore, cell densities of the urethra and the urethral rhabdosphincter across various age groups, and the appearance of apoptosis were examined to explore the changes in these structures during the aging process. MATERIALS AND METHODS: Specimens were obtained from 16 male and 7 female cadavers 5 weeks to 92 years old. Histological sections were taken from 3 different levels of the rhabdosphincter and urethra. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling method was used to detect apoptosis in the urethra and rhabdosphincter. In all specimens relative volume densities of the striated muscle fibers, apoptotic indexes and diameters of the rhabdosphincter and urethra were determined. RESULTS: An age dependent increase of apoptosis of the striated muscle fibers of the rhabdosphincter led to a dramatic decrease in the number of striated muscle cells. In the 5-week-old neonate 87.6% and in the 91-year-old woman 34.2% of the rhabdosphincter consisted of striated muscle cells. Overall, a direct linear correlation between the age of the specimens and decrease in volume densities of the striated muscle cells was evident. CONCLUSIONS: The dramatic decrease in the number of striated muscle cells in the rhabdosphincter of the elderly due to apoptosis represents the morphological basis for the high incidence of stress incontinence in this population.

Adolescent↗
PubMed1999

Crossing vessels at the ureteropelvic junction: detection with contrast-enhanced color Doppler imaging.

PURPOSE: To investigate the feasibility of imaging crossing vessels at the ureteropelvic junction (UPJ) preoperatively by means of contrast agent-enhanced color Doppler imaging (CDI). MATERIALS AND METHODS: Twenty-nine patients (13 female patients, 16 male patients; age range, 17-76 years; mean age, 45 years) with symptomatic UPJ obstruction were examined with CDI before and after intravenous infusion of the contrast agent. The type (i.e., arterial or venous) and position of the vessel relative to the UPJ (i.e., anterior or posterior) were assessed. The CDI findings were correlated with the surgical findings at laparoscopic pyeloplasty. RESULTS: Among the 29 patients, crossing vessels were detected with nonenhanced CDI in 15 patients, with enhanced CDI in 22 patients, and with laparoscopy in 23 patients. Enhanced CDI depicted crossing vessels in 22 (96%) of the 23 laparoscopically confirmed cases compared with nonenhanced CDI, which depicted 15 (65%) of the 23 cases. The rate of detecting crossing vessels increased significantly with use of the contrast agent (P < .016, McNemar test). CONCLUSION: Compared with nonenhanced CDI, contrast-enhanced CDI significantly improves the detection of crossing vessels at the UPJ and is useful in the presurgical evaluation of UPJ obstruction.

Adolescent↗
PubMed1998

Improvement of specificity in PSA-based screening by using PSA-transition zone density and percent free PSA in addition to total PSA levels.

BACKGROUND: The clinical value of prostate-specific antigen (PSA) density in differentiating between prostate cancer and benign prostatic hyperplasia has been the subject of several studies. In this context the question has been raised about the diagnostic benefit of PSA transition-zone density (PSA-TZ density = total PSA/transition-zone volume) in the detection of prostate cancer. In the following study the value of PSA-TZ density alone and in combination with free PSA was investigated. METHODS: Between August 1995-May 1996, 308 first-line screening volunteers with elevated total PSA levels ranging from 2.5-10.0 ng/ml were evaluated. All patients underwent digital rectal examination, transrectal ultrasound, and transrectal ultrasound-guided biopsy of the prostate. Prior to these investigations, serum was obtained and total as well as free PSA levels were obtained. PSA transition-zone density (PSA-TZ density) was defined as follows: PSA-TZ density = total PSA/transition-zone volume. RESULTS: ROC curve analyses for PSA-TZ density showed that by using a PSA-TZ density of more than 0.22 ng/ml/cc as a biopsy criterion, 24.4% of negative biopsies could be avoided; ROC curve analyses for free PSA showed that by using percent free PSA <20% as a biopsy criterion, 45.5% of negative biopsies could be eliminated. When combining these two diagnostic tests, 54.2% of negative biopsies could be avoided. CONCLUSIONS: We conclude that PSA-TZ density, in addition to total and free PSA, is a new opportunity which renders it possible to calculate the likelihood of detecting prostate cancer on repeat biopsies in an individual patient.

Biopsy↗