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T Schuster

Publications and source records attributed to T Schuster.

At least 19 recordsLinked to original sources
PubMed2006

Is the anorectal sphincter damaged during a transanal endorectal pull-through (TERPT) for Hirschsprung's disease? A 3-dimensional, vector manometric investigation.

BACKGROUND/PURPOSE: The transanal endorectal pull-through technique (TERPT) for Hirschsprung's disease (HD) exercises considerable traction on the anorectal tissue during dissection. So the question arises as to whether TERPT impairs the integrity of the anorectal sphincter. Computerised 8-channel vector manometry allows a segmental, 360 degrees analysis of muscular defects along the anal canal. Such data after TERPT are not available yet. METHODS: Between 2002 and 2004, 7 children underwent primary TERPT for HD of the rectosigmoid. All could be recruited for follow-up examinations. Stooling pattern, rectal examination, conventional 4-channel and computerised 8-channel vector manometry were assessed; the anal sphincter pressure at rest (ASPR), rectoanal inhibitory reflex (RIR), anal canal length (ACL), high pressure zone (HPZ), maximal segmental pressure (max SP), segmental/total asymmetric index (SAI/TAI), vector volume at rest (VV) were studied. Mean pre- and postoperative values were compared (pre/post). RESULTS: After a mean of 14 months (range 3-21 months) all children had spontaneous bowel movements, with no complaints of encopresis or constipation. 4-channel manometry revealed an unchanged ASPR (48.1/49.2 mmHg). RIR was present in 1/7. Computerised 8-channel comparison revealed no changes for ACL (15.4/16 mm), HPZ (60/53.19 % of ACL), SAI (17.6/18.63 %) and TAI (35.8/35.63 %). A postoperative increase was noted for max SP squeeze (141.4/178.7 mmHg) and VV (38 161/46 680 mmHg/cm (2)). In conclusion, the TERPT for HD preserves the functional integrity of the anorectal sphincter complex and has a favourable clinical and manometric outcome.

Anal Canal↗
PubMed2005

Effect of first line therapy including efavirenz and two nucleoside reverse transcriptase inhibitors in HIV-infected children.

OBJECTIVE: In an intent-to-treat study, reduction of viral load, increase in CD4 cell count, clinical benefit and adverse reactions were examined in HIV-infected children receiving first line therapy including efavirenz. METHODS: The data of 10 perinatally infected children (median age: 5.8 years) were evaluated during a treatment period of 24 months. Viral load and CD4 cell count were measured every 4 - 8 weeks. Pharmacokinetic evaluations of efavirenz were performed in all patients at study onset. Adverse reactions were reported after obtaining interval history and examination. RESULTS: At base line, median CD4 cell count was 378 cells/microl (21%) and median viral load was 350,000 copies/ml (5.5 log10 copies/ml). After 24 months of treatment, the median viral load reduction was > 3.5 log10 copies/ ml and HIV-1 RNA < 50 copies/ml was found in 8/10 children (80%). Median CD4 cell count increased to 721 cells/microl (24%) after 3 months and was maintained at a level of >1000 cells/microl (> 25%) after 24 months of treatment. Regarding efavirenz levels, C min. values ranged from 845 to 3550 ng/ml (median: 1845 ng/ml) and C max. values from 2380 to 24 200 ng/ ml (median: 3670 ng/ml). The most common adverse effect was a mild skin rash (4/10 children). CNS symptoms were recorded in one patient and no hyperlipidaemia was seen. CONCLUSION: First line therapy with efavirenz and two NRTIs was well tolerated by HIV-1 infected children and the reduction of viral load seems to be similar to single protease inhibitor-containing regimens.

Administration, Oral↗
PubMed2005

Functional imaging for determination of nephroblastoma: an obligatory diagnostic program.

In Europe, 1.7 % of children with predicted nephroblastoma undergo neoadjuvant chemotherapy without being correctly diagnosed. It is necessary to reduce the number of misdiagnoses. In a girl who was referred to our institute with the diagnosis of nephroblastoma of the right kidney, DMSA scan revealed a hypertrophic compensation of the contralateral nephropathy in the lower part. Functional imaging studies of the kidney should be performed in patients in whom the type of pathology of a suspect mass in the kidney region is unclear, including a careful scrutiny of the MRI scan.

Child↗
PubMed2005

Tubularized incised plate (TIP) urethroplasty (Snodgrass) in primary hypospadias repair.

In the past TIP urethroplasty became a preferred technique for distal hypospadias repair, and subsequently gained worldwide popularity and acceptance. The procedure gives good functional results and a cosmetic appearance that is superior to that obtained by flip-flap or onlay preputial flap repairs. In addition, this procedure is associated with a fairly low rate of complications. From 06/2000 to 04/2004 we performed 100 primary TIP urethroplasties in patients with distal hypospadias. The age of the patients at the time of surgical correction was 16 months to 10 years with a mean of 41.4 months. All patients underwent the procedure under general anesthesia supplemented by additional pain management with a penile block anesthesia or caudal anesthesia. The surgical technique is described. During follow-up (23.5 months) we observed 2 types of complications: formation of a urethrocutaneous fistula (5 pts., 5 %) and formation of meatal stenosis (17 pts., 17 %) with a steady decrease with no stenosis formation in the last 8 months of this series. A key point might be the length of the dorsal incision of the urethral plate which should not touch the dorsal lip of the anticipated neomeatus. There were no other complications, and the cosmetic results were good in all cases.

Child↗
PubMed2004

Ureterocystoneostomy (UCN) and subureteral collagen injection (SCIN): combined one-stage correction of high-grade bilateral vesicoureteral reflux (VUR) in children.

The treatment of vesicoureteral reflux (VUR) is still a controversial issue. The efficacy of medical treatment appears to be equal to that of operative procedures in avoiding new formation of renal scars. However, there are generally accepted indications for operative procedures including bilateral high-grade VUR, especially in young patients. Ureteral reimplantation (UCN) is the operative treatment of choice in cases with high-grade VUR. Alternatively in cases with lower-grade VUR, injection of bulking agents under the refluxive orifice can be performed. It is also generally accepted that UCN with extravesical preparation of the ureter and the bladder should not be done bilaterally in a one-stage procedure. Postoperative bladder dysfunction may result due to detrimental neurogenic effects. In this study we report on our operative procedure in cases with bilateral high-grade VUR, during which we perform intra/extravesical UCN (mod. Leadbetter-Politano) of the higher-grade refluxive ureter, and (open) subureteral collagen injection (SCIN) of the lower-grade refluxive orifice as a combined one-stage procedure. In this study 50% of the patients had no VUR on either side after the first combined procedure. 15% of the patients showed significant down-grading of VUR of the injected side. These patients underwent a 2nd endoscopic SCIN. 35% of the patients showed no change of VUR of the injected side after the first procedure; these patients underwent reimplantation of this side in another operation. Accordingly, 50% of patients with bilateral high-grade VUR required a 2nd operative procedure under full anesthesia to achieve loss of VUR on both sides. None of the patients showed bladder dysfunction postoperatively. Mean follow-up after the last operative correction was 29.9 months (6 - 84 months).

Algorithms↗
PubMed2004

Incomplete duplication of the bladder. A case report.

Duplication of the bladder is an unusual congenital anomaly and is usually associated with other anomalies. We report an unusual case of duplicated bladder in a 8-year-old boy resulting from a septum in the sagittal plane. This malformation was associated with dysplasia of the left kidney and agenesis of the left testicle. The basic defects that lead to duplication of the lower urinary tract are unknown.

Child↗
PubMed2003

NCAM180 and glutamate receptor subtypes in potentiated spine synapses: an immunogold electron microscopic study.

Activity-dependent changes in expression and localization of the largest major isoform of the neural cell adhesion molecule NCAM180 and three subtypes of glutamate receptors predominantly expressed in the outer part of the molecular layer of the dentate gyrus of adult rats-the NMDA receptor NR2A, the AMPA receptor GluR2/3, and the metabotropic glutamate receptor mGluR1 - were investigated using postembedding immunogold labeling, and electron microscopy. In synaptic membranes of nonstimulated spine synapses, NCAM180 and NR2A accumulated in the center of the postsynaptic density, whereas GluR2/3 and mGluR1 were distributed evenly. Twenty-four hours following induction of long-term potentiation in vivo, NCAM180 and NR2A accumulated at the edges of postsynaptic densities, whereas GluR2/3 was localized more centrally. Also, the distribution of gold particles per synapse significantly changed for NCAM180, NR2A, and mGluR1. Thus, changes in synaptic strength are associated with concomitant changes in the expression and distribution of NCAM180 and glutamate receptors, particularly of the NR2A subtype.

Animals↗
PubMed2003

Osteoradionecrosis of the jaws as a side effect of radiotherapy of head and neck tumour patients--a report of a thirty year retrospective review.

This retrospective study aimed to demonstrate the incidence and the aetiological factors involved in osteoradionecrosis (ORN) in a group of 830 head and neck tumour patients who received radiotherapy between 1969 and 1999. The data showed an over all incidence of 8.2% and a 3-fold higher incidence for men than for women. Osteoradionecrosis was most commonly located in the body of the mandible. Concerning the risk factors, a negative influence was shown for advanced tumours, segmental resections of the mandible and pre-/post-radiation tooth extractions. Tooth extractions were found to be responsible for 50% of all cases. The osteoradionecroses were observed significantly earlier in patients who received pre-surgical radiotherapy than those who received post-surgical radiotherapy. Combined pre-surgical radio- and chemotherapy significantly hastened the appearance of osteoradionecrosis compared to pre-surgical radiotherapy alone. Only 40% of patients with osteoradionecrosis could be healed completely by means of surgery and antibiotic medication. Hyperbaric oxygenation (HBO) therapy was performed only in individual cases. The data suggest that osteoradionecrosis has a multifactorial aetiology. Therefore, a very close follow-up of tumour patients and a strict prophylactic management are required.

Adult↗
PubMed2003

Lymphangioma colli--a new classification contributing to prognosis.

The aim of the study was to introduce a classification of lymphangioma colli, which allows us to predict the expected morbidity and prognosis with surgical treatment. We defined 4 types, dependent on the volume of the lymphangioma as assessed by prenatal ultrasound or clinically: type I included tumors which had no or only a minimal effect on the contour of the neck; type II lymphangiomas were smaller than a line drawn at the lateral border of the head; type III tumors exceeded this line; in type IV the lymphangioma extended beyond the midline of the body. We report on the pre- and postoperative findings in 36 cases operated on between 1988 and 2000, mean follow-up was 4.2 years. 25 % of the cases were classified as type I, 36 % as type II, 22 % as type III, and 17 % as type IV. Cesarean section was carried out for 79 % of type III and IV lymphangiomas following prenatal diagnosis (71 %) and for 14 % of type I and II. MRT was indicated in 38 % of type II compared to 86 % in type III and IV lymphangiomas. Endoscopy was necessary in 25 % of type III and in 66 % of type IV lymphangiomas. In 2 cases (type I and IV), imaging revealed an intrathoracic portion. In 64 % of type I and II cases, resection was complete compared to 21 % in infants with more extended tumors. In all type IV cases, at least one further operation was required, likewise in 25 % of type III lymphangiomas. Postoperative effusion and infection occurred significantly more often in group IV than in groups I to III. 5 nerval lesions remained in children with operated type IV lymphangioma and 2 in type III cases. A visible lack of facial symmetry was evident at the follow-up examination in 83 % of type IV cases and moderate asymmetry was found in 19 % of all type I and II cases. Tracheostomy and gastrostomy were required only in type IV. The introduced classification of lymphangioma colli enables predictive statements to be made concerning the morbidity and prognosis with surgical therapy. The prognosis in type I is excellent; in type II, a cosmetically significant facial asymmetry remains in only 15 %. In type III lymphangiomas postoperative complications occurred in 38 % of cases, the necessity for reoperation with definitive lesions occurred in only 25 %. Morbidity gets significantly higher and the prognosis is worse if the lymphangioma exceeds the midline of the body.

Decompression, Surgical↗
PubMed2002

Laparoscopic resection of a congenital liver cyst and simultaneous closure of a diaphragmatic defect in a 5-month-old infant.

Congenital liver cysts are an unusual finding and present a difficult diagnostic challenge. In a 5-month-old infant, routine echocardiography detected a cystic lesion (3 cm in diameter) just below the diaphragm. All conventional diagnostics, including magnetic resonance imaging (MRI), failed to clarify its etiology definitively. Moreover, a phrenic irregularity was suspected at the site of Morgagni. Finally, laparoscopy (5-mm scope and instruments) confirmed the diagnosis of a solitary liver cyst and a diaphragmatic defect. Using a Harmonic scalpel, the cyst was resected and the diaphragmatic defect was closed with interrupted nonabsorbable sutures. The patient's postoperative course was uneventful. Pathological analysis showed a true liver cyst with mesothelial lining and hepatic residues. Retrospective speculation suggests a common embryologic origin for both malformations. In conclusion, laparoscopy allowed final diagnosis and simultaneous treatment of an infant with the rare combination of a liver cyst and a diaphragmatic defect. To our knowledge, this case represents the first endosurgical experience of such a simultaneous procedure.

Cysts↗
PubMed2002

Management of the primary obstructed megaureter (POM) and indication for operative treatment.

Presented is the diagnostic and therapeutic management of the primary obstructed megaureter (POM). 42 patients presented with 53 ureteral units (UU) of POM (5 females, 37 males, 36 neonates and 6 children aged 3 to 8 years). Of the 53 megaureters 10 UU (19%) were on the right and 27 UU(51 %)were on the left. 8 patients (19%)with 16 UU (30%)showed a bilateral abnormality. In 41% of the patients, hydronephrosis had been discovered by prenatal ultrasound. All patients were evaluated postnatally by ultrasound (US), voiding cysturethrogram (VCUG), intravenous pyelogram (IVP) and diuresis renogram (MAG-3) (DR). Due to the percentage of urinary drainage,the renogram results were classified into different categories:no obstruction, functional obstruction, equivocal and obstruction. A partial renal function was also calculated. Follow-up of the patients ranges between 5 to 48 months (mean: 22.1). All patients underwent serial US and serial DR were obtained in 36 patients. Initially, 9 (17%) UU showed a functional obstruction, 34 (64.2%) an equivocal and 10 (18.8%) an obstructive urinary drainage pattern. 2 kidneys showed a significant decreased partial function of 20, respectively 26%. Surgery was performed in an initial im-paired renal function with an obstructive pattern or in cases with normal function and at least equivocal urinary drainage pattern with no improvement or deterioration of the urinary drainage and/or function in the follow-up. Considering these criteria, 5(9.6%) patients needed surgery. No loss of kidney function has been observed in follow-up. DR is the most valuable diagnostic tool. Criteria interpreting the results are demonstrated in this article.

Child↗
PubMed2001

Immunoelectron microscopic localization of the neural recognition molecules L1, NCAM, and its isoform NCAM180, the NCAM-associated polysialic acid, beta1 integrin and the extracellular matrix molecule tenascin-R in synapses of the adult rat hippocampus.

We have investigated the possibility that morphologically different excitatory glutamatergic synapses of the "trisynaptic circuit" in the adult rodent hippocampus, which display different types of long-term potentiation (LTP), may express the immunoglobulin superfamily recognition molecules L1 and NCAM, the extracellular matrix molecule tenascin-R, and the extracellular matrix receptor constituent beta1 integrin in a differential manner. The neural cell adhesion molecules L1, NCAM (all three major isoforms), NCAM180 (the largest major isoform with the longest cytoplasmic domain), beta1 integrin, polysialic acid (PSA) associated with NCAM, and tenascin-R were localized by pre-embedding immunostaining procedures in the CA3/CA4 region (mossy fiber synapses) and in the dentate gyrus (spine synapses) of the adult rat hippocampus. Synaptic membranes of mossy fiber synapses where LTP is expressed presynaptically did not show detectable levels of immunoreactivity for any of the molecules/epitopes studied. L1, NCAM, and PSA, but not NCAM180 or beta1 integrin, were detectable on axonal membranes of fasciculating mossy fibers. In contrast to mossy fiber synapses, spine synapses in the outer third of the molecular layer of the dentate gyrus, which display postsynaptic expression mechanisms of LTP, were both immunopositive and immunonegative for NCAM, NCAM180, beta1 integrin, and PSA. Those spine synapses postsynaptically immunoreactive for NCAM or PSA also showed immunoreactivity on their presynaptic membranes. NCAM180 was not detectable presynaptically in spine synapses. L1 could not be found in spine synapses either pre- or postsynaptically. Also, the extracellular matrix molecule tenascin-R was not detectable in synaptic clefts of all synapses tested, but was amply present between fasciculating axons, axon-astrocyte contact areas, and astrocytic gap junctions. Differences in expression of the membrane-bound adhesion molecules at both types of synapses may reflect the different mechanisms for induction and/or maintenance of synaptic plasticity.

Animals↗
PubMed2001

Reduced perisomatic inhibition, increased excitatory transmission, and impaired long-term potentiation in mice deficient for the extracellular matrix glycoprotein tenascin-R.

The role of the extracellular matrix molecule tenascin-R (TN-R) in regulation of synaptic transmission and plasticity in the CA1 region of the hippocampus was studied using mice deficient in expression of this molecule. The mutant mice showed normal NMDA-receptor-mediated currents but an impaired NMDA-receptor-dependent form of long-term potentiation (LTP) as compared to wild-type littermates. Reduced LTP in mutants was accompanied by increased basal excitatory synaptic transmission in synapses formed on CA1 pyramidal neurons. A possible mechanism for increased excitatory synaptic transmission in mutants could involve modulation of inhibition, since TN-R and its associated carbohydrate HNK-1 decorate perisomatic interneurons. Indeed, the amplitudes of unitary perisomatic inhibitory currents were smaller in mutants compared to wild-type mice. Thus, our data show that a deficit in TN-R results in reduction of perisomatic inhibition and, as a consequence, in an increase of excitatory synaptic transmission in CA1 to the levels close to saturation, impeding further expression of LTP.

Animals↗
PubMed2001

A computerized vector manometry and MRI study in children following posterior sagittal anorectoplasty.

The study was designed to evaluate computerized eight-channel vector manometry (8CVM) and pelvic floor magnetic resonance imaging (MRI) as methods to assess the anal sphincter following posterior sagittal anorectoplasty (PSARP) for anorectal malformations, in particular the functional capacity of the sphincter structures in correlation with postoperative MRI findings. Seventeen children had been operated upon for a rectovesical, -urethral, or -vaginal fistula including one female cloacal malformation; 4 had a secondary PSARP. Mean follow-up was 5.57 years. Continence was evaluated with a modified Kelly score. A CVM technique with an eight-channel perfusion catheter was used. In addition to software-supported data, the manometric parameters included a score-system assessing three different pressure zones of the anal canal qualitatively on the three-dimensional image of the anal sphincter profile. The same procedure was performed on sagittal, oblique axial, and oblique coronal MRI. Furthermore, the thickness of the sphincter muscle was assessed at the level of the maximal mean segmental pressure. All children had decreased absolute vector-volumetry values at rest and on squeezing. Correlation with the clinical score was poor. Correlation of the manometric score with the clinical course was similar to the correlation of MRI score with clinical course (R = 0.425; P = 0.1). Thirteen children demonstrated normal or increased sphincter length; 5 of these had a decreased high-pressure zone (HPZ). The position of the anorectum in the sphincter muscles could be evaluated by the vector-volumetry image as anatomic in 11 cases, nearly correctly positioned in 4, and ectopic in 1 child. MRI detected 2 cases of malposition, 10 anatomic, and 4 nearly-anatomic findings. Correlation of the manometric score with the MRI score and the thickness of the sphincter muscle at the HPZ was significantly high (R = 0.801; P < 0.0001). 8CVM is thus highly sufficient in illustrating the function of the sphincter musculature seen on pelvic floor MRI. Both methods only moderately reflect clinical follow-up, since continence depends on more than sphincter ability.

Anal Canal↗
PubMed2001

Transient pseudohypoaldosteronism secondary to posterior urethral valves--a case report and review of the literature.

In transient pseudohypoaldosteronism (TPHA), renal tubular resistance to aldosterone is thought to be secondary to renal disease. We report a case of TPHA caused by posterior urethral valves associated with urinary tract infection and review 62 cases previously reported. The infant presented with unspecific signs of vomiting and dehydration, so that pyloric stenosis was first suspected. Laboratory data and retroperitoneal sonography led to the diagnosis TPHA. This case illustrates that urine culture and renal ultrasonography should be performed in any infant with electrolyte disturbances to exclude infection or obstructive uropathy.

Aldosterone↗
PubMed2001

Clinical impact of differential renal function to indicate and assess pyeloplasty and the significance of coexisting vesicoureteral reflux.

PURPOSE: In patients with ureteropelvic junction obstruction (JPJO) who are conservatively treated, 5% to 10% of them show a deterioration of renal function without recovery after delayed pyeloplasty. Should surgery be indicated based on observed deterioration of differential renal function (DRF)? Can we expect improvement of the DRF after pyeloplasty? What other influencing parameters may affect DRF? MATERIALS AND METHODS: In this study, the authors examined 85 ureterorenal junctions that had undergone the Anderson-Hynes technique for surgical correction of UPJO. Based on the values obtained from the preoperative DRF (Tc-99m mercaptoacetyltriglycine), the cases were separated into three categories: group I had poor DRF (less than 11% of total renal function [TRF]), group II had moderate DRF (11% to 33% of TRF), and group III had adequate DRF (more than 33% of TRF). Twelve months after surgery, renal function was reassessed. The results were correlated with age at surgery, symptoms, coexisting vesicoureteral reflux, and drainage. RESULTS: Seven ureterorenal junctions (8%) comprised group I, 15 (18%) comprised group II, and 63 (74%) comprised group III. After UPJO repair, 13% showed marked improvement in DRF, 86% remained stable, and 1% exhibited diminished function. In 50% of the renal cases with preoperative DRF less than 33%, postoperative improvement was seen. In follow-up renal scans, 30 cases (35%) revealed nonobstructive drainage, whereas the remaining 53 junctions (62%) showed moderate delayed drainage. Both the moderate delayed group (57%) and the nonobstructive group (50%) showed similar DRF improvement. Sixty-six percent of the patients with impaired DRF improved after pyeloplasty performed within the first 3 months of life, compared with 42.8% of patients in whom surgery was performed after 5 years of age. Vesicoureteral reflux was evident in 27.2% of the patients with preoperative impaired DRF compared with 11% with normal DRF. Forty-five percent of the patients with impaired DRF and no improvement after surgery had coexisting vesicoureteral reflux, compared with 9% of those with postoperative improvement. CONCLUSIONS: Sustained renal impairment after pyeloplasty is likely as a result of preexisting renal dysplasia with vesicoureteral reflux. Moderate delayed drainage after surgery does not affect DRF. Surgery for UPJO should be indicated independent of a DRF follow-up (except very low DRF) or the age at the time of diagnosis.

Child↗