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Biomedical subjects

A Stenzl

Publications and source records attributed to A Stenzl.

At least 55 records · Page 3Linked to original sources
PubMed2001

Treatment of giant ancient pelvic schwannoma.

A 32-year-old patient presented with urinary retention and chronic constipation. Computerized tomography and magnetic resonance imaging showed a 10 x 11cm encapsulated tumor with cystic areas lying ventral to the sacrum. There was no evidence of invasion of bladder or rectum. At laparotomy, a 10 x 11 cm mass was found in the left pelvis. Final pathology revealed an ancient schwannoma. In most large series, 80% to 90% of the primary retroperitoneal tumors are malignant. Retroperitoneal schwannomas can be benign or malignant, roughly half of the reported cases showed malignancy. Benign schwannomas may arise along the course of any myelinated nerve, with the acoustic neuroma being the most frequent site. Immunostaining showed a strong expression of S-100 protein. The staining for this protein is helpful for differentiation of a benign schwannoma from a malignant peripheral nerve sheath tumor and from other benign spindle cell tumors. The treatment of choice for benign schwannomas is complete excision. Recurrence or persistence seems to be associated with incomplete resection, which occurred in 10% of the reported cases. After surgery, the patient had normal erection, normal micturition, and normal defecation but no symptoms of motor and sensory disturbances.

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

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↗
PubMed1999

Cellular and humoral immune responses in patients with metastatic renal cell carcinoma after vaccination with antigen pulsed dendritic cells.

PURPOSE: Dendritic cells are the most potent stimulators of immune responses including antitumor responses. We performed a pilot study of cultured antigen loaded dendritic cells in patients with metastatic renal cell carcinoma. MATERIALS AND METHODS: Dendritic cells were obtained by culturing plastic adherent mononuclear cells from peripheral blood for 5 days in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4. Day 5 dendritic cells were loaded with cell lysate from cultured autologous tumor cells and with the immunogenic protein keyhole-limpet hemocyanin (KLH) which serves as a helper antigen and as a tracer molecule. During the antigen pulse dendritic cells were activated with a combination of tumor necrosis factor-alpha and prostaglandin E2. Dendritic cells were administered by 3 intravenous infusions at monthly intervals. Cellular and humoral immune responses to KLH and cell lysate were measured in vitro before and after the vaccinations. RESULTS: Preparation of 12 dendritic cell vaccines from patients with advanced renal cell carcinoma was successful. Treatment with fully activated CD83+ dendritic cells was well tolerated with moderate fever as the only side effect. Potent immunological responses to KLH and, most importantly, against cell lysate could be measured in vitro after the vaccinations. CONCLUSIONS: Our data demonstrate that a dendritic cell based vaccine can induce antigen specific immunity in patients with metastatic renal cell carcinoma. Dendritic cell based immunotherapy represents a feasible, well tolerated and promising new approach for the treatment of advanced renal cell carcinoma.

Aged↗
PubMed1998

Restoration of voluntary emptying of the bladder by transplantation of innervated free skeletal muscle.

BACKGROUND: On the basis of studies with animals and experience with functioning muscle transfer in plastic surgery, we have developed a surgical technique to restore detrusor function for patients with bladder acontractility in whom there is no treatment alternative. METHODS: Three patients (aged 26 years, 28 years, and 68 years) with bladder acontractility as a result of spinal-cord injury (two patients) and chronic overdistension (one patient), who required catheterisation for bladder emptying for 5 years, 2 years, and 2 years, respectively, took part in our study. The patients were treated with microneurovascular free transfer of autologous latissimus dorsi muscle to the bladder to restore detrusor function. Follow-up included clinical and urodynamic evaluation, colour doppler sonography, intravenous urography, and flow-mode computerised tomography. FINDINGS: The three patients voluntarily emptied their bladders at 16 weeks, 16 weeks, and 30 weeks after surgery, respectively. There was no need for further catheterisation throughout the follow-up period. On urodynamic assessment at 12 months after the operation bladder capacity was found to be 600 mL, 600 mL, and 650 mL, residual urinary volume 0 mL, 50 mL, 90 mL, and maximum flow rate 26 mL/s, 25 mL/s, and 18 mL/s, respectively. Activity at the transplanted latissimus dorsi was confirmed by ultrasonography and flow-mode computerised tomography. INTERPRETATION: Microneurovascular free transfer of latissimus dorsi muscle to functionally restore a deficient detrusor muscle has proved to be successful for the three patients in our study. This technique may also be an option to restore the function of other smooth-muscle organs.

Adult↗
PubMed1998

Three-dimensional computed tomography of the reconstructed lower urinary tract: technique and findings.

The aim of this pilot study in 54 patients was to improve the visualization of the anatomy and postoperative changes in the pelvic topography after bilateral ureteroileal urethrostomy, using surface rendering of electron beam CT (EBCT) data for the 3D display. Fifty-four patients (39 men and 15 women) were scanned with an EBCT unit between 3 and 110 months after performing orthotopic ureteroileal urethrostomy ("Hemi-Kock") or ureteroileal rectosigmoidostomy. Various parameters and spatial viewing points were used in the 3D reconstruction, which was performed interactively on external workstations with commercially available software. The anti-reflux nipple was visualized as a distinct structure in all patients. In 8 patients with an interval of more than 12 months between surgery and CT, the pouch had developed an ovoid shape almost indistinguishable from the original bladder. The segmented data sets were partly animated to display the anatomy as virtual endoscopy. Three-dimensional depiction and virtual endoscopy of the neobladder using EBCT are a new way of imaging the postoperative anatomy. Its clinical efficacy in the diagnosis of inconclusive postoperative morbidity, especially voiding problems, and planning of necessary therapy have to be the subject of further evaluation.

Adult↗