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A Stenzl

Publications and source records attributed to A Stenzl.

At least 37 records · Page 2Linked to original sources
PubMed2004

[Tissue engineering of the urethra and ureter].

Congenital or acquired disorders of the urethra or ureter often require adequate tissue transfer for reconstruction. A variety of biomaterials have proved to be useful in the reconstruction of the urethra or ureter in animal models and meanwhile even clinically. Innovative tissues such as acellular matrices can be placed in the host and function as a scaffold to allow the natural process of tissue regeneration. Biodegradable scaffolds can also be used as cell transplantation vehicles for the reconstruction of urethral or ureteral tissue. One of the limitations of cell-based tissue engineering techniques however is the difficulty of growing genitourinary-associated cells in large quantities in primary cultures. It can be speculated that stem cell research might help to overcome this specific problem in the future.

Absorbable Implants↗
PubMed2004

Renal tubular alteration by crystalluria in stone disease-an experimental study by means of MDCK cells.

OBJECTIVES: Physicochemical properties of urine do not explain the formation of urinary stones. Clinical findings and results of animal experiments suggest that alteration to the renal tubular cell plays a key role in the initiation of urinary stone formation. It is not clear whether this is a primarily intracellular alteration of metabolic origin which, after lysis of the renal tubular cell in the lumen, presents a nucleus for the formation of concretions, or whether in the lumen it is tubular cell damage induced by crystalluria that triggers the formation of urinary stones. MATERIALS AND METHOD: Using Madin-Darby canine kidney cells, the influence of crystalluria on the renal tubular cell was tested in cell cultures. The influence of parathyroid hormone, vitamin D(3), oxalate and calcium concentrations and the extent to which these processes can be inhibited by allopurinol and selenium were investigated. RESULTS: Calcium oxalate monohydrate crystals produced reproducible damage to the renal tubular cell which was independent of parathyroid hormone and vitamin D(3). The crystalluria-induced effects were unrelated to the oxalate and calcium concentration or the pH. Allopurinol and selenium were able to inhibit the processes. CONCLUSION: The results indicate secondary involvement of the renal tubular cell in lithogenesis as a result of luminal alteration caused by calcium oxalate crystals. Mechanical damage and interaction between crystal and tubular cell lead to the apposition of crystals. The nephroprotective effect of allopurinol and selenium as antioxidants might explain the benefit of allopurinol found clinically in terms of stone metaphylaxis.

Animals↗
PubMed2003

[ImmunoCyt--a new urine test in diagnosis of bladder cancer].

ImmunoCyt is a new immunocytologic fluorescence test promising a higher diagnostic sensitivity, esp. for TaG1 carcinomas. The aim of the study was to evaluate the sensitivity of the test in diagnosis of bladder cancer as compared to both urinary cytology and histopathology. A total of 121 spontaneous urine samples of 92 patients (age range 28 to 86, mean 62.5 years) was examined. 41 of the samples were of patients suspicious of transitional cell carcinoma, 46 of patients in whom symptoms were suggestive of tumor recurrence, and 34 of patients who were part of a follow-up protocol. Cystoscopy was performed in all patients. The ImmunoCyt-test was carried out according to the manufacturers protocol using 3 fluorescent monoclonal antibodies. A total of 113 specimens could be evaluated. In 87 cystoscopy and/or histology was negative (control group). There was histologic evidence of 7 pTaG1, 4 pTaG2, 8 pT1G2/G3, and 7 pT2G2/G3 bladder cancers. As for ImmunoCyt and cytology specificity was 83.9% and 91.9%, resp. The combined specificity was 81.6%. Sensitivity amounted to 38.5% and 34.6%, resp., the combined sensitivity to 53.8%. Sensitivity for TaG1 carcinomas was 14.3% each, for TaG2 carcinomas 25% and 50%, for T1G2/G3 carcinomas 37.5% each, and for T2G2/G3 carcinomas 71.4% and 42.9%, resp. In our study the ImmunoCyt test did not show the expected increase in the detection of TaG1 bladder cancers. Because of false-positive results the test should only be used in combination with urinary cytology which reveals a higher specificity. In conclusion the ImmunoCyt test can not replace cystoscopy (with biopsy) in diagnosis and monitoring of bladder cancer.

Adult↗
PubMed2003

[Is adrenalectomy an indispensable part of nephrectomy? Results of a multivariate statistical analysis].

Since in the absence of clinically overt metastatic disease tumorous lesions within the adrenal gland are found in only 2-10% of cases, the majority of renal cell cancer patients are overtreated by adrenalectomy as an integral part of nephrectomy. The medical records of 847 patients undergoing adrenalectomy in combination with nephrectomy irrespective of the local extent of the primary tumor or the clinical stage at first diagnosis were reviewed to determine the reliability of currently available imaging modalities regarding the prediction of adrenal gland metastases. Several patient and tumor characteristics correlated with the presence of intra-adrenal metastases, and their prognostic value was determined by a multivariate logistic regression model. Metastatic spread into the adrenal gland was observed in 27 of 847 (3%) patients. In only three of eight patients in whom the adrenal was identified as the only metastatic site, preoperative abdominal CT scans were interpreted as false negative. During multivariate statistical analysis, only the presence of distant metastases, vascular invasion within the primary tumor, and multifocal growth of renal cell cancer within the tumor-bearing kidney were identified to independently predict the likelihood for the presence of intra-adrenal metastases. None of the patient or tumor characteristics evaluated reliably predicted the likelihood for the presence of adrenal metastases in patients without evidence of disseminated metastatic spread. As we believe and as the current investigation demonstrates, routine adrenalectomy should not be recommended in cases of preoperatively normal radiological examinations.

Adrenal Gland Neoplasms↗
PubMed2003

[Impact of tumor size on long-term survival of patients with organ-confined renal cell cancer].

PURPOSE: As a result of the observation that the potential biological aggressiveness of even early stage renal cell cancer (RCC) strongly correlates with tumor size, the 5th edition of the TNM system (1997), which classifies all renal tumors up to a maximum diameter of 7 cm as T1, was modified in the current classification to distinguish T1a and T1b tumors based on a cut-off of 4 cm. Only a few larger investigations supporting this cut-off are available in the literature and these are based on univariate statistical analysis. To determine whether this cut-off best reflects the correlation between aggressive potential and tumor size and thus differentiates patients at low or high risk of progression, this investigation was performed using both univariate and multivariate statistical analysis. MATERIALS AND METHODS: Between 1981 and 2000, a total of 652 patients underwent tumor nephrectomy for renal cell carcinoma. Of these, the 243 patients with local RCC not extending beyond the renal capsule were subjected to univariate (log rank test) and multivariate (Cox regression model) statistical analysis. RESULTS: It became evident that, while during univariate analysis the prognostic calue of a cut-off size of 4 cm was confirmed, multivariate analysis identified the highest relative risk of cause-specific death (2.93) in those patients with tumors larger than 5 cm maximum diameter. CONCLUSIONS: The 5 cm cut-off thus appears to best determine the clinical prognosis for patients undergoing tumor nephrectomy for early stage renal call cancer. Taking this into consideration, the present study clearly demonstrates the reed for a multivariate statistical approach when the current modification of the TNM classification system is critically reevaluated.

Adult↗
PubMed2003

Free neurovascular transfer of latisstmus dorsi muscle for the treatment of bladder acontractility: II. Clinical results.

PURPOSE: Until now patients with bladder acontractility were destined to lifelong clean intermittent catheterization with all of its inherent risks. Previous experimental studies demonstrated that voluntary voiding can be restored by microneurovascular free transfer of a carefully selected muscle flap. We present the selection criteria, modifications in technique, followup schedule and long-term results in 20 patients treated with transplantation of latissimus dorsi muscle to the bladder. MATERIALS AND METHODS: In 20 patients with bladder acontractility requiring intermittent catheterization for at least 2 years we performed latissimus dorsi detrusor myoplasty. Preoperative evaluation included urodynamic assessment, cystoscopy, upper tract imaging and electromyography of the rectus muscle. The procedure involves transfer of a free neurovascular latissimus dorsi muscle flap to the pelvis where it is anastomosed to the lowest motor branches of the intercostal nerve and deep inferior epigastric vessels. Patients were instructed to attempt voluntary voiding 3 months postoperatively. Followup included urodynamic evaluation, biannual Doppler ultrasonography and annual dynamic computerized tomography. RESULTS: Annual dynamic computerized tomography and/or biannual Doppler ultrasonography demonstrated vascularization and contractility of all transplanted muscle flaps. Mean followup is 44 months (range 18 to 74). Of the 20 patients 14 were able to void spontaneously within 4 months postoperatively with post-void residual volumes of less than 100 cc, voluntary voiding was restored by bladder neck incision in 4 and 2 (10%) still require self-catheterization. Postoperative detrusor pressures ranged from 5 to 218 cm. H2O (mean 72, median 55). None of the patients had morphological and functional changes of the upper tract, or de novo incontinence postoperatively. CONCLUSIONS: Functioning free muscle transplantation was able to restore voluntary voiding in patients who had previously been dependent on long-term catheterization. Voluntary voiding has been maintained several years postoperatively without deterioration of upper tract function.

Adolescent↗
PubMed2001

Urethra-sparing cystectomy and orthotopic urinary diversion in women with malignant pelvic tumors.

BACKGROUND: To the authors' knowledge, few data exist regarding the functional and oncologic outcome of pelvic tumors in women with urethra-sparing cystectomy and orthotopic urinary diversion to the urethra. PATIENTS AND METHODS: The combined data of 102 women age 28-79 (mean, 59 yrs) years who underwent a urethra-sparing cystectomy and orthotopic urinary diversion for either primary bladder cancer (96 patients), carcinoma of the uterine cervix (2 patients), carcinoma of the vagina (1 patient), primary fallopian tube carcinoma (1 patient), uterine sarcoma (1 patient), or rectal carcinoma (1 patient) were reviewed. The histology of the 96 primary bladder tumors was 81 transitional cell carcinomas (TCC), 8 adenocarcinomas, 5 squamous cell carcinomas, 1 small cell carcinoma, and 1 unclassified. Follow-up ranged from 1.5-100 months (mean, 26 mos; median, 24 mos). In all patients, the bladder neck and up to 1 cm in length of the adjacent urethra were removed with the bladder. An ileal orthotopic neobladder procedure was performed if staging biopsies of the bladder neck and intraoperative frozen section of the urethral margin revealed no tumor. RESULTS: There was no perioperative mortality, and an early and late complication rate requiring secondary intervention in 5 (5%) and 12 (12%) patients. With 88 of 102 patients alive and 83 of 102 patients disease free, a disease-specific survival of 74% and a disease-free survival of 63% was estimated at 5 years. No pelvic recurrence was seen in 81 patients with TCC. Three pelvic recurrences occurred, two tumors of the inner genitalia and one adenocarcinoma of the bladder, none of them in the area of the urethra or its supplying autonomic nerves. Daytime continence was 82%; nocturnal continence was 72%. Twelve (12%) patients were unable to empty their bladders completely and needed some form of catheterization. CONCLUSIONS: The functional and oncologic outcome of female patients with an orthotopic urinary diversion to a remnant urethra was found to be comparable to that found in large studies on males. An orthotopic neobladder proved to be an oncologically safe option for women with pelvic tumors and was found to provide quality of life when there was adherence to previously defined selection criteria.

Adult↗
PubMed2001

Restoring voluntary urinary voiding using a latissimus dorsi muscle free flap for bladder reconstruction.

We present our data using innervated latissimus dorsi muscle (LDM) free flaps to assist acontractile bladder function. Twelve dogs were used. In group I (n = 3), the LDM flaps were elevated and wrapped around silicon reservoirs; in group II (n = 4), the LDM flaps were transferred into the pelvis and used to reconstruct bladders that had 50% of their detrusor muscle wall removed; group III (n = 5) was the same setup as group II but the bladder mucosa was also removed with 50% detrusor wall. The LDM flaps were electrically stimulated and electromyography, cystography, urodynamic, and hydrodynamic measurements were performed. In clinical studies, LDM flaps were used in 11 patients (age range, 9-68 years). Our animal studies demonstrated that LDM flaps are capable of generating pressures (190 cm H(2)O at 15 mL and 35 cm H(2)O at a 10 mL in group I at 6 months) to void the bladder. In group II, contractions were present after 9 months. Eight of 11 patients who underwent LDM free flap were able to void voluntarily and without catheterization. LDM flap activity was confirmed using ultrasonography/tomography. Our clinical studies indicated that contractile function can be restored using LDM free flaps.

Adolescent↗
PubMed2001

[Reconstruction of the lower urinary tract. Developments at the beginning of a new century].

Gastrointestinal segments are currently by far the most popular method to create a bladder substitute. Attempts have been made to further reduce the morbidity and burden for patients by using minimal invasive techniques for both cystectomy and urinary diversion. However, laparoscopy for acceptable forms of urinary diversion is time consuming and costly. A neobladder "off the shelf" would be a better solution. Tissue engineering is an exciting new field which enables the cultivation and expansion of individual bladder cells obtained by transurethral biopsy, the attachment of these cells to a support matrix, and their reimplantation into the body. Advances both in biomaterials as well as in the cultivation and expansion of bladder cells are described. Promising routine clinical applications of tissue engineering may still need several years. Free neurovascular muscle transfer to the bladder demonstrated both experimentally and clinically to be a suitable treatment modality in patients with bladder acontractility. This may therefore be the next logical step towards an improved bladder substitute by combining well vascularized flaps with urothelial cell seeding. Thus a combination of commonly used flap techniques and tissue engineering may soon be possible.

Forecasting↗
PubMed2001

Treatment of postoperative urinary retention by elongation of tension-free vaginal tape.

Tension-free vaginal tape elongation with a polypropylene intermediate piece was successfully carried out in a patient with urinary retention after an initial tension-free vaginal tape surgical procedure. This resulted in immediate residual-free voiding and continence, unchanged at 6 months follow-up. Postoperative urinary retention may thus be treated by elongation instead of dissection of the tension-free vaginal tape.

Adult↗
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↗
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↗