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Biomedical subjects

M Hohenfellner

Publications and source records attributed to M Hohenfellner.

At least 55 records · Page 3Linked to original sources
PubMed1999

Orthotopic bladder substitution in women: functional evaluation.

PURPOSE: Orthotopic bladder substitution following cystectomy in women has recently been introduced at some specialized centers. Studies of such a procedure should consider the oncological and functional outcomes. We analyzed only the functional results of orthotopic bladder substitution since followup is too short (about 2 years) for a valid oncological assessment. MATERIALS AND METHODS: From October 1994 to November 1997, 60 women with a mean age of 48.3 years underwent standard radical cystectomy and orthotopic diversion (ileal W-neobladder with subserous tunnel in 47 and hemi-Kock reservoir in 13). The oncological criterion was organ confined invasive bladder cancer. RESULTS: There was no perioperative mortality. Postoperative complications included fatal pulmonary embolism in 1 woman, deep vein thrombosis in 2, prolonged ileus in 1 and fistula of the vaginal pouch in 3, which was repaired successfully. Cancer recurred in the pelvis in 2 cases and as distant metastases in 5. Of the patients 43 had been followed for a mean of 20.2 months (range 6 to 36), and 32 were continent day and night, 1 was totally incontinent, 2 had daytime stress incontinence and 6 had nighttime incontinence. Six women had difficulty emptying the pouch spontaneously with concomitant residual urine due to acute angulation between the urethra and pouch. CONCLUSIONS: Orthotopic bladder substitution after standard radical cystectomy in select women provides a satisfactory functional outcome. Failure of complete emptying seems to be due to anatomical rather than functional reasons.

Adult↗
PubMed1998

Bladder acellular matrix graft in rats: its neurophysiologic properties and mRNA expression of growth factors TGF-alpha and TGF-beta.

To assess the neurophysiologic properties and molecular mechanisms of the bladder acellular matrix graft (BAMG), we performed cystometric and neurophysiologic studies in male Sprague-Dawley rats (n = 46) at varying intervals. The animals were assigned to 3 groups: 1) normal, 2) partial cystectomy (>50%), and 3) partial cystectomy (>50%) and grafting with a BAMG of equal size. Additionally, matrix-grafted and host bladders were processed for analysis of mRNA expression of transforming growth factor (TGF)-alpha, TGF-beta1, TGF-beta2, and TGF-beta3 by reverse transcriptase polymerase chain reaction. Matrix-grafted bladders showed a significantly higher bladder capacity at 3 and 6 weeks and 4 months than those with partial cystectomy alone, and a significantly higher bladder capacity at 4 months than in normal controls (P < or = 0.01). Residual urine volume was significantly increased at 4 months. Electrostimulation of the pelvic nerve provoked generalized bladder contractions, a response that was reduced by atropine and hexamethonium. Variable induction of TGF-alpha, TGF-beta1, TGF-beta2, and TGF-beta3 gene transcription was evident in the BAMG, with prominent mRNA expression of TGF-alpha and TGF-beta1 6 months after surgery. These cystometric results and detrusor responses to stimulation provide further evidence that graft components do not interfere with host components. Matrix-grafted rat bladders generate, although not increased over time, adequate intravesical pressure responses to produce sustained voiding. Gene expression of different growth factors may be significant in understanding their role in the development and differentiation of the BAMG for partial bladder replacement.

Animals↗
PubMed1998

Bilateral chronic sacral neuromodulation for treatment of lower urinary tract dysfunction.

PURPOSE: Chronic sacral neuromodulation aims at functional restoration of selected forms of nonneurogenic and neurogenic bladder dysfunction. The original technique, as described by Tanagho and Schmidt, provides unilateral sacral nerve stimulation via an implanted stimulator powering an electrode inserted into a sacral foramen. Its drawback was that the implant failed unpredictably in some patients despite previous successful percutaneous test stimulation. Therefore, we modified the stimulation technique to improve the efficacy of chronic sacral neuromodulation. MATERIALS AND METHODS: Guarded bipolar electrodes powered by an implantable neurostimulator were attached bilaterally directly to the S3 nerves through a sacral laminectomy in 9 women and 2 men (mean age 43.4 years). Of the patients 5 had urinary incontinence due to detrusor hyperactivity and 6 had urinary retention from detrusor hypocontractility. Mean followup with repeated urodynamics was 13 months (range 9 to 28). RESULTS: Four significant complications were encountered in 4 patients. In 10 patients the urological sequelae of the neurological disorder were alleviated significantly (50% or more), including 5 who experienced complete relief of symptoms. CONCLUSIONS: The efficacy of chronic sacral neuromodulation can be improved by bilateral attachment of electrodes directly to the sacral nerves.

Adult↗
PubMed1998

Treatment of interstitial cystitis: comparison of subtrigonal and supratrigonal cystectomy combined with orthotopic bladder substitution.

PURPOSE: We retrospectively evaluate the outcome of interstitial cystitis treated with subtrigonal or supratrigonal cystectomy and orthotopic bladder substitution. MATERIALS AND METHODS: Of 22 women and 1 man a mean of 51 years old with interstitial cystitis refractory to conservative therapy 17 were treated with subtrigonal cystectomy and ureteral reimplantation (group 1), and 6 were treated with supratrigonal cystectomy directly above the ureteral orifices (group 2). Both groups underwent orthotopic bladder substitution with an ileocecal pouch (Mainz pouch I). RESULTS: Postoperatively functional capacity significantly increased from a mean plus or minus standard error of mean 46 +/- 5 to 346 +/- 57 ml. in group 1 and 34 +/- 61 to 319 +/- 29 ml. in group 2 (p < 0.001). Daytime and nighttime urinary frequency significantly decreased from 24 +/- 2 to 8 +/- 1 and 7 +/- 1 to 2 +/- 1 ml., respectively, in group 1 and 28 +/- 2 to 6 +/- 1 and 6 +/- 1 to 1 +/- 1 ml., respectively, in group 2 (p < 0.001). At a mean followup of 93.9 months 14 patients in group 1 (82%) are completely symptom-free, and 1 has tolerable residual urinary urgency and suprapubic pain. At a mean followup of 31.5 months all group 2 patients are symptom-free and void spontaneously, whereas 41% of the group 1 patients require self-catheterization after subtrigonal cystectomy. CONCLUSIONS: For interstitial cystitis refractory to conservative treatment subtotal cystectomy with orthotopic bladder substitution with the ileocecal pouch (Mainz pouch I) is a valid therapeutic option. In this series supratrigonal and subtrigonal cystectomy resulted in similar relief of symptoms but the former appears to provide better functional bladder rehabilitation.

Adult↗
PubMed1998

[Treatment of insufficiency of the anal sphincter by sacral spinal nerve stimulation with implantable neurostimulators].

The feasibility of permanent electrostimulation of the sacral spinal nerves was studied in patients with fecal incontinence and no detectable morphological lesions and thus not amenable to conventional surgical management. Applying acute percutaneous stimulation with needle electrodes, the most relevant sacral spinal nerve for striated sphincter muscle function was identified (sacral spinal nerve S3 or S4). The therapeutic potential of stimulation was tested by subchronic stimulation with temporary wire electrodes and, if effective, permanent electrodes were implanted in four patients. Long-term sacral spinal nerve stimulation persistently improved anal continence and increased the function of the striated muscular anal sphincter.

Adult↗
PubMed1997

Neurostimulation for bladder evacuation: is sacral root stimulation a substitute for microstimulation?

OBJECTIVE: To determine by anatomical and functional studies whether stimulation of sacral rootlets might permit selective stimulation of autonomic fibres, thus avoiding the detrusor/sphincter dyssynergia characteristic of current techniques of neurostimulation for bladder evacuation. MATERIALS AND METHODS: In 10 male mongrel dogs, the S2 root was isolated and its constituent rootlets followed from their origin in the spinal cord to the point of exit from the dura. The entire root and the individual rootlets were then stimulated, including intra- and extra-dural stimulation and at proximal, mid and distal levels. RESULTS: Neuroanatomical and histological findings showed that rootlets of ventral S2 maintain their identity throughout their intradural course; some carry predominantly autonomic fibres, some predominantly somatic and some a mixture of the two. CONCLUSION: It appears surgically feasible to identify, isolate and sever the predominantly somatic rootlets intradurally, sparing the predominantly autonomic rootlets for inclusion in extradural electrode placement around the entire sacral root, thus eliminating sphincteric interference with detrusor contraction for voiding at low pressure.

Animals↗
PubMed1997

Appendix carcinoma invading the urinary bladder.

We report a case of an appendix carcinoma invading the urinary bladder. In contrast to other bowel tumors invading the bladder, history and symptoms were consistent with a primary bladder tumor. This is due to the unique anatomical position of the appendix where the tumor did not hinder passage of bowel contents or cause melena. Findings on physical examination as well as diagnostic imaging and transurethral resection were inconclusive. Consideration of local progression of an appendix carcinoma is an important differential diagnosis. In contrast to other vesical or extravesical T4 tumors, the appendix carcinoma offers a good chance for resection en bloc by right-sided hemicolectomy and partial cystectomy.

Adenocarcinoma, Mucinous↗
PubMed1997

Experimental evaluation of free versus pedicled fascial flaps for sling surgery of urinary stress incontinence.

PURPOSE: Bladder neck suspension using an autologous fascial sling is an established surgical technique for treatment of urinary stress incontinence. However, the biological fate and physical properties of autologous fascial sling yet remain to be determined. MATERIALS AND METHODS: Our study was designed to evaluate in an animal model of twenty rabbits fascial slings from free and pedicled fascial flaps of two different widths (7 mm and 15 mm.) and uniform length (60 mm.) in respect to changes of length, width, tensile strength and histological criteria of vitality and integrity 3 months after surgery. RESULTS: The results 3 months after surgery revealed shrinkage in length by 37% (31%-46%) of the original length, shrinkage in width by 63% (60%-69%) of the original width and reduction of tensile strength of 53% (51%-55%) without consistent differences between free and pedicled flaps or 7 mm. and 15 mm. wide flaps. In the groups with 7 mm. wide flaps a total of two dystrophic slings (1 pedicled, 1 free) were seen; however, no dystrophies were seen in 15 mm. wide flaps. On microscopy, all slings were vital regardless of their surgical configuration. CONCLUSIONS: In summary, on macroscopic, microscopic and physical examination no gross differences between free and pedicled slings could be detected, so that preferences for use of free or pedicled fascial flaps could not be established for clinical applications in sling surgery. However, 15 mm. wide flaps had a lower incidence of dystrophy and retained greater absolute tensile strength than 7 mm. wide flaps.

Analysis of Variance↗
PubMed1996

Continent diversion with the Mainz pouch.

From 1983 until July 1994, 561 patients in 2 urology departments (Mainz and Wuppertal) underwent a Mainz pouch 1 procedure. The Mainz pouch 1 was used for bladder augmentation in 60 patients, for orthotopic bladder substitution in 61 patients, and for continent cutaneous urinary diversion in 440 patients. In the group of continent cutaneous urinary diversion, the continence mechanism applied was an ileal intussusception nipple in 270 patients, an appendix stoma in 146 patients, a submucosal seromuscular bowel-flap tube in 14 patients, and a submucosal full-thickness bowel-flap tube in 10 patients. Indications for urinary diversion were bladder cancer in 339 patients, anatomical or functional loss of bladder capacity in 179 patients, and other primary or secondary malignancies of the bladder or true pelvis in 43 patients. After a mean follow-up period of 57 months (range, 3-127 months), early and late complications were encountered in 12% and 37% of the patients, respectively. In the bladder-augmentation group, 93% of the patients are completely continent day and night. All but three patients, who empty their reservoir by intermittent self-catheterization (CIC), void spontaneously by abdominal straining. In the orthotopic bladder-substitution group, 95% of the patients are continent during the daytime. To prevent urinary leakage, 13% have to empty their reservoirs regularly at 4-h intervals and 13% have to perform CIC to avoid residual urine. Among the patients treated with continent cutaneous urinary diversion, stoma failure occurred in 11%, stoma stenosis was encountered in 13% and required open revision in 2%, endoscopical incision in 10%, and conservative treatment (dilation) in 1% of cases.

Cecum↗
PubMed1996

Continent reconstruction of detrusor hyperreflexia by sacral bladder denervation combined with continent vesicostomy.

We describe a two-stage surgical procedure for complex hyperreflexic detrusor dysfunction refractory to conservative therapy. First, ventral and dorsal sacral rhizotomies (S2 to S4/5) are performed to restore vesical storage function and abolish autonomic dysreflexia. Then, after an interval of several weeks to allow for detrusor relaxation, continent vesicostomy is performed for suprapubic clean intermittent catheterization. The procedure is effective both objectively and subjectively, is only moderately invasive, and requires neither sophisticated nor expensive medical equipment.

Adult↗
PubMed1996

Urolithiasis in horseshoe kidneys: therapeutic management.

OBJECTIVES: We sought to compare the results of different therapeutic strategies in patients with horseshoe kidneys and urolithiasis. METHODS: The records of 47 patients (28 male, 19 female; mean age, 42 years) with horseshoe kidney treated for urolithiasis from 1983 to 1994 were reviewed retrospectively and follow-up studies of 38 of 47 patients were obtained after 7 to 122 months (mean, 79). RESULTS: Open surgery was performed in 6 patients with ureteropelvic junction obstruction; 1 required nephrectomy of a nonfunctioning right kidney and the other 5 are stone free. Percutaneous nephrolithotomy (PNL) was performed in 4 patients with normal drainage and a moderate to large stone burden; 3 became stone free and the other required extracorporeal shock-wave lithotripsy (ESWL) secondarily. In the remaining 37 patients with normal drainage and a small to moderate stone burden, ESWL achieved a 100% disintegration rate and a 76% stone-free rate. CONCLUSIONS: The presence of anatomic obstruction will necessitate open surgery for urolithiasis in patients with horseshoe kidney; however, in patients with normal urinary drainage PNL or ESWL can be considered, either singly or as a part of combination therapy. When management is tailored to the individual patient's needs, results of stone treatment can be equivalent to those in normal kidneys.

Adolescent↗
PubMed1995

Electrical stimulation of sacral spinal nerves for treatment of faecal incontinence.

Functional deficits of the striated anal sphincteric muscles without any apparent gross defect often result in a lack of ability to postpone defaecation by intention or in faecal incontinence in response to increased intra-abdominal or intra-rectal pressure. We applied electrostimulation to the sacral spinal nerves to increase function of the striated muscles of the anal sphincter. Of three patients followed for 6 months, two gained full continence and one improved from gross incontinence to minor soiling. Closure pressure of the anal canal increased in all. Preliminary data indicate that anal closure pressure increases with the duration of stimulation. Continuous stimulation of sacral spinal nerves can help some patients with faecal incontinence. It may be possible to promote continence with intermittent stimulation.

Adult↗
PubMed1995

In situ tunneled bowel flap tubes: 2 new techniques of a continent outlet for Mainz pouch cutaneous diversion.

In Mainz pouch continent cutaneous urinary diversion, introduction of the in situ tunneled appendix as the continent outlet in 1990 has simplified the surgical technique and greatly increased the acceptance of the procedure. Based on the results of long-term animal studies, 2 new techniques of a continent outlet were randomly used with a Mainz pouch 1 procedure (ileocecal pouch) in 17 patients in whom the appendix was not available or usable for construction of a continent outlet. According to the flap valve principle of the tunneled appendix, in 17 patients a small caliber conduit was created from large bowel wall at the lower pole of the cecum and was tunneled in situ under the mucosa. In technique 1 (seromuscular bowel flap tube), a tube lined by serosa was created from a pedicled island flap of large bowel wall in 11 patients. In technique 2 (full thickness bowel flap tube), a tube lined by mucosa was created from a pedicled flap of large bowel wall in 6 patients. After a mean followup of 8 months (range 2 to 17) 16 of 17 patients catheterize the reservoir at intervals of 4 to more than 6 hours using 14 to 16F catheters and are continent day and night without leakage. The only major complication in this series was incontinence in 1 patient with a seromuscular bowel flap tube who died of metastatic tumor 6 months postoperatively.

Dermatologic Surgical Procedures↗
PubMed1995

Reinnervation of the rat bladder with a somatic nerve and a striated muscle flap.

PURPOSE: Current techniques of ventral sacral root stimulation to regain voluntary motor control of the decentralized urinary bladder depend upon intact parasympathetic innervation of the detrusor. We investigated techniques that might allow restoration of motor control of the bladder after efferent parasympathetic impairment. MATERIALS AND METHODS: In a chronic rat model, we evaluated whether motor control of a peripherally denervated bladder could be restored by transplantation of autologous excitable tissues and subsequent electrostimulation. Either a somatic nerve or a striated muscle flap was used as the transplant. RESULTS: Four months after the initial surgery, electrostimulation of the somatic nerve implant provoked bladder contractions--a response that was blocked by atropine. Stimulation of the nerve innervating the striated muscle flap also provoked bladder contractions; these were not affected by atropine and were slightly reduced by hexamethonium. CONCLUSION: Reinnervation of the bladder with somatic nerves or striated muscles is possible in principle. Future experiments will clarify the clinical significance of electrostimulation of such implants.

Animals↗