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Biomedical subjects

A Stenzl

Publications and source records attributed to A Stenzl.

At least 19 recordsLinked to original sources
PubMed2001

US findings in the scrotum of extreme mountain bikers.

PURPOSE: To sonographically investigate whether mountain bikers have a higher prevalence of scrotal abnormalities compared with that in nonbikers. MATERIALS AND METHODS: Eighty-five male mountain bikers (mean age, 25 years; age range, 17-45 years) and 31 healthy nonbikers (mean age, 24 years; age range, 15-37 years) were examined for scrotal findings at ultrasonography (US). Only male subjects with a history of extensive off-road biking (> or =2 h/d 6 d/wk; covered distance, >5,000 km/y) were assigned to the group of mountain bikers, whereas the control group did not engage in bicycling. In addition to clinical evaluation, US examination of the scrotum was performed by using a linear-array transducer operating at a frequency of 8.0 MHZ: RESULTS: Eighty (94%) mountain bikers had abnormal findings at scrotal US. Thirty-nine (46%) had a history of intermittent scrotal tenderness or discomfort but no severe scrotal trauma. Abnormal findings at US included scrotal calculi in 69 (81%), epididymal cysts in 39 (46%), epididymal calcifications in 34 (40%), testicular calcifications in 27 (32%), hydroceles in 24 (28%), varicoceles in nine (11%), and testicular microlithiasis in one (1%). In the control group, abnormal findings were noted in five (16%), all of whom had epididymal cysts. The overall difference in the number of scrotal abnormalities in bikers compared with the number in nonbikers was significant (P <.0001, chi2 test). CONCLUSION: US shows a significantly higher prevalence of extratesticular and testicular disorders in these mountain bikers compared with nonbikers.

Adolescent↗
PubMed2001

Photodynamic diagnosis with 5-aminolevulinic acid in the treatment of secondary urethral tumors: first in vitro and in vivo results.

OBJECTIVES: Photodynamic diagnosis (PDD) is able to detect dysplasia and transitional cell cancer of the bladder. We report our first experiences using PDD in the urethra. MATERIALS AND METHODS: Three patients with secondary transitional cell cancer of the urethra were treated by using PDD. 5-Aminolevulinic acid (ALA) was applied in a mixture with lubricant to achieve long enough contact with the urothelium. Negative effects were tested in vitro on three bladder cell lines. RESULTS: In vitro assays showed no enhanced negative effects on the viability of bladder cells using the combination of ALA/lubricant and medium in comparison to lubricant/medium alone. All patients showed markedly fluorescent areas, which were resected. The treatment was well tolerated without side effects attributable to the photosensitizer containing lubricant. CONCLUSION: Lubricant with ALA forms a viscous solution, which can successfully be used for PDD in the urethra. Thus marking tumors by fluorescence may improve transurethral resection and thus preserve the urethra.

Adult↗
PubMed2001

Bladder reconstruction using a prevascularized capsular tissue seeded with urothelial cells.

PURPOSE: Recent advances in cell biology and tissue engineering have involved various avascular or acellular scaffolds with or without seeded cells. These techniques are frequently complicated by tissue necrosis, contracture and resorption. We used a vascularized matrix prelaminated with autologous cultured urothelial cells to reconstruct bladder wall defects. MATERIALS AND METHODS: A silicone block inserted into the right groin of 50 male Wistar rats directly superficial to the inferior epigastric vessels was used to induce capsule pouch formation. Urothelial cells harvested simultaneously and cultured were then suspended in fibrin glue and seeded into the newly formed capsule after removing the silicone block. After 1 week the prelaminated flap was transposed into a surgically created bladder wall defect. Experimental groups included rats with a urothelial cell seeded capsule pouch sacrificed at 1 and 4 weeks, respectively, after bladder reconstruction. In control rats scaffolds were treated only with fibrin glue or saline before transposition. RESULTS: Hematoxylin and eosin and immunohistochemical staining showed a continuous multilayered urothelial lining along the transposed prelaminated capsule flap in the experimental groups with better survival compared to controls treated only with fibrin glue (80% mortality) or saline (100% mortality). The surviving 3 control animals did not have a urothelial lining. CONCLUSIONS: Vascularized prefabricated flaps lined with culture derived urothelial cells were successfully used for bladder reconstruction in a rat model. The technique of prefabricating a vascularized scaffold lined with autologous urothelial cells may provide a method for future reconstruction of the genitourinary systems.

Animals↗
PubMed2001

Life after cystectomy and orthotopic neobladder versus ileal conduit urinary diversion.

Patients frequently complain about changes in their everyday life after radical cystectomy and urinary diversion. The aim of this study was to compare subjective morbidity of ileal neobladder to the urethra versus ileal conduit urinary diversion and to elucidate its influence on quality of life. A total of 102 patients who underwent radical cystectomy due to a bladder malignancy were included in the study: 69 patients (67.6%) with an orthotopic neobladder and 33 patients (32.4%) with an ileal conduit. The compliance was 99% and mean follow-up was 37 months. All patients completed two retrospective quality-of-life questionnaires, namely the QLQ-C30 and a questionnaire developed at our institution to elucidate specific items regarding urinary diversion. The questioning was performed by a nonurologist. The results obtained from the validated (QLQ-C30) and our self-designed questionnaire clearly demonstrate that patients with an orthotopic neobladder better adapt to the new situation than patients with an ileal conduit. In addition, neobladder to the urethra improves quality of life due to a better self-confidence, better rehabilitation as well as restoration of leisure, professional, traveling, and social activities, and reduced risk of inadvertent loss of urine. For example, 74.6% of neobladder patients felt absolutely safe with the urinary diversion in contrast to 33.3% in the ileal conduit group. Only 1.5% of neobladder patients had wet clothes caused by urine leakage during day versus 48.5% of ileal conduit patients; 92.8% of neobladder patients felt not handicapped at all; and 87% felt not sickly or ill in contrast to 51.5% and 66.7% of ileal conduit patients, respectively. Moreover, 97% of our neobladder patients would recommend the same urinary diversion to a friend suffering from the same disease in contrast to only 36% of ileal conduit patients. The results obtained by this study demonstrate that quality of life is preserved in a higher degree after orthotopic neobladder than after ileal conduit urinary diversion.

Cystectomy↗
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↗
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

Quality of life after cystectomy and orthotopic neobladder versus ileal conduit urinary diversion.

The impact of bladder removal and urinary diversion for patients' everyday life is largely unknown. The aims of this study were to compare subjective morbidity of ileal neobladder to the urethra versus ileal conduit urinary diversion and to elucidate its influence on quality of life. A total of 102 patients who underwent cystectomy due to a bladder malignancy were included in the study. In 69 patients (67.6%) an orthotopic neobladder and in 33 patients (32.4%) an ileal conduit was performed as urinary diversion. The compliance was 99% and mean follow-up was 37 months. All patients completed two retrospective quality of life questionnaires, namely the QLQ-C30 and a questionnaire developed at our institution to ask for urinary diversion specific items. The questioning and assessment was performed by non-urologists. The results obtained from the validated (QLQ-C30) and our own specially compiled questionnaire clearly demonstrate that patients with an orthotopic neobladder are more able to adapt to the new situation than patients with an ileal conduit. In addition, neobladder to the urethra improves the quality of life because it improves self-confidence, causes better rehabilitation as well as the restoration of leisure, professional, travelling, and social activities, and reduced risk of inadvertent loss of urine. For example, 92.8% of neobladder patients did not feel handicapped at all, and 87% did not feel sick or ill, in contrast to 51.5% and 66.7% of ileal conduit patients, respectively. Of the neobladder patients, 74.6% felt absolutely safe with the urinary diversion in contrast to 33.3% in the ileal conduit group. Only 1.5% of neobladder patients had wet clothes caused by urine leakage during the day, versus 48.5% of ileal conduit patients. Moreover, 97% of our neobladder patients would recommend the same urinary diversion to a friend suffering from the same disease, but only 36% of ileal conduit patients would do so. These results demonstrate that the quality of life is preserved to a higher degree after orthotopic neobladder than after ileal conduit urinary diversion.

Aged↗
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↗
PubMed1999

Virtual reality of the lower urinary tract in women.

Advances in computerized and imaging technology permit both students and doctors to depict the anatomy of the human pelvis more realistically than with previous methods. Further refinements outline fine pelvic structures, such as the nerve plexus, which may as a result be spared during major pelvic surgery, thus preserving the function of the bladder neck and urethra. Dynamic computerized tomography or magnetic resonance imaging, coupled with three-dimensional depiction of the lower urinary tract and its adjacent structures, enable visualization of the whole lower urinary tract and the pelvic floor musculature in both continent and incontinent women. In patients with a reconstructed lower urinary tract computer-assisted image processing shows the postoperatively altered topographical anatomy. This may be clinically useful for interpretation of unexpected findings with conventional imaging modalities, postoperative morbidity, and surgical planning of a lower abdominal reoperation. Examples of our own work regarding the innervation of female pelvic organs, dynamic depiction of the bladder and pelvic floor musculature during straining in normal and incontinent women, and the situation of female patients after undergoing an anterior pelvic exenteration with subsequent orthotopic neobladder procedure, are given. In addition, the data of these patients have been compiled for virtual reality endoscopy, which is useful for patient consent and for teaching residents, students and nurses.

Female↗
PubMed1999

Bladder substitution.

Preliminary data have shown that composite reservoirs consisting of gastric segments in combination with ileum or colon may reduce metabolic problems. Orthotopic neobladders are the most natural way to reconstruct the urinary bladder and are a safe option in selected male and female patients. Experimental and preliminary clinical data about new methods using autologous muscle transfer and tissue engineering are promising.

Female↗
PubMed1999

Reconstruction of large soft tissue defects in the inguinal and suprapubic region using a variety of flaps.

OBJECTIVES: To review a variety of optional reconstructive procedures for the surgical management of extensive soft tissue defects after radically curative or palliative resection of tumors, scars or damaged tissue in the inguinal and suprapubic region. METHODS: Clinical experience with 24 pedicled or free flaps applied in 20 patients to cover extensive defects with exposed underlying structures are presented. The proper selection of flap was based on the individual requirements of each patient taking into consideration age, cause, size, shape and deepness of the defect, donor site morbidity, the patient's general condition and the situation of vascular supply of the adjacent regions. RESULTS: A high success rate with a moderate rate of only minor complications leads to a reasonably short hospital stay with a definitive defect cover. In the cases of palliation a distinct improvement in quality of survival could be achieved. CONCLUSIONS: After extensive or radical resection almost every defect may be sufficiently covered in a single stage. The inferior epigastric flap serves as the most versatile flap, but nevertheless appropriate selection of the reconstructive technique must be adapted considering the complexity of the illness and defect in each individual case.

Abdomen↗
PubMed1999

Mature dendritic cells induce T-helper type-1-dominant immune responses in patients with metastatic renal cell carcinoma.

We performed a pilot study on a dendritic cell (DC)-based vaccine in 4 patients with advanced renal cell carcinoma. The vaccine consisted of cultured blood DCs loaded with autologous tumor cell lysate plus keyhole limpet hemocyanin (KLH) and matured with a combination of tumor necrosis factor alpha and prostaglandin E(2). We describe the immune response against KLH induced by DC-based immunization in a patient undergoing an objective partial response and compare it with the responses observed in patients with either stable or progressive disease. The patient with the clinical response developed strong delayed-type hypersensitivity (DTH) against KLH after a single vaccination with antigen-loaded DCs, whereas the other patients failed to develop DTH reactivity even after repeated vaccinations. Antigenic stimulation of mononuclear cells (MNCs) induced proliferation and IFN-gamma but not IL-4 production as well as expression of the chemokine receptor CXCR3 consistent with a T-helper (Th) type-1 bias. Exogenous IL-12 enhanced and exogenous IL-4 diminished IFN-gamma production. In the 2 patients with stable disease two or more vaccinations were required to induce maximal MNC responses. In the patient with progressive disease MNC responses were hardly detectable. Anti-KLH antibodies appeared with different kinetics but could be detected in the serum of all patients. Isotype analysis revealed the presence of IgM, IgG(1), IgG(2) and IgG(3) as well as IgA and complete absence of IgE. The patient with progressive disease also developed IgG(4) antibodies indicative of a deviation towards Th2. Cultured blood DCs can be a potent vaccine for the antigen-specific immunization of patients with advanced kidney cancer. KLH serves as a tracer molecule which allows determination of the magnitude, kinetics and Th bias of the cellular and humoral immune response induced by DC-based immunization. The data also suggest that Th type-1-dominant immune responses involving DTH reaction are required for the induction of tumor regression.

Adjuvants, Immunologic↗