Impact of increased cell loss on the repopulation rate during fractionated irradiation in human FaDu squamous cell carcinoma growing in nude mice

PURPOSE

To determine the impact of increased necrotic cell loss on the repopulation rate of clonogenic cells during fractionated irradiation in human FaDu squamous cell carcinoma in nude mice.

MATERIALS AND METHODS

FaDu tumours were transplanted into pre-irradiated subcutaneous tissues. This manoeuvre has previously been shown to result in a clear-cut tumour bed effect, i.e. tumours grow at a slower rate compared with control tumours. This tumour bed effect was caused by an increased necrotic cell loss with a constant cell production rate. After increasing numbers of 3-Gy fractions (time intervals 24 or 48 h), graded top-up doses were given to determine the dose required to control 50% of the tumours (TCD50). All irradiations were given under clamp hypoxia.

RESULTS

With increasing numbers of daily fractions, the top-up TCD50 decreased from 37.9 Gy (95% CI: 31; 45) after single dose irradiation to 14.1 Gy (8; 20) after irradiation with 15 fractions in 15 days. Irradiation with 18 daily 3-Gy fractions controlled more than 50% of the tumours without a top-up dose. After irradiation with six fractions every second day, the top-up TCD50 decreased to 26.9 Gy (22; 32). No further decrease of the TCD50 was observed after 12 and 18 irradiations every second day. Assuming a constant increase of TCD50 with time, the calculated doubling time of the clonogenic tumour cells (Tclon) was 7.8 days (4.4; 11.3). The Tclon calculated for FaDu tumours growing in pre-irradiated tissues was significantly longer (p=0.0004) than the Tclon of 5.1 days (3.7; 6.5) determined under the same assumptions in a previous study for FaDu tumours growing in normal subcutaneous tissues.

CONCLUSIONS

Increased necrotic cell loss by pre-irradiation of the tumour bed resulted in longer clonogen doubling times during fractionated radiotherapy of human FaDu squamous cell carcinoma. This implies that a decreased necrotic cell loss might be the link between reoxygenation and repopulation demonstrated previously in the same tumour model.

Selective inhibition of the epidermal growth factor receptor tyrosine kinase by BIBX1382BS and the improvement of growth delay, but not local control, after fractionated irradiation in human FaDu squamous cell carcinoma in the nude mouse

PURPOSE

To investigate the effect of BIBX1382BS, an inhibitor of the epidermal growth factor receptor tyrosine kinase, on proliferation and clonogenic cell survival of FaDu human squamous cell carcinoma in vitro, and on tumour growth and local tumour control after fractionated irradiation over 6 weeks in nude mice. FaDu human squamous cell carcinoma is epidermal growth factor receptor positive and significant repopulation during fractionated irradiation was demonstrated in previous experiments.

MATERIALS AND METHODS

Receptor status, receptor phosphorylation, cell cycle distribution, cell proliferation and clonogenic cell survival after irradiation were assayed with and without BIBX1382BS (5 microM) in vitro. Tumour volume doubling time, BrdUrd and Ki67 labelling indices and apoptosis were investigated in unirradiated tumours growing in NMRI nude mice treated daily with BIBX1382BS (50 mg kg(-1) body weight orally) or carrier. Tumour growth delay and dose-response curves for local tumour control were determined after irradiation with 30 fractions within 6 weeks.

RESULTS

BIBX1382BS blocked radiation-induced phosphorylation of the epidermal growth factor receptor and reduced the doubling time of FaDu cells growing in vitro by a factor of 4.9 (p=0.008). Radiosensitivity in vitro remained unchanged after incubation with BIBX1382BS for 3 days and decreased moderately after 6 days (p=0.001). BIBX1382BS significantly reduced the volume doubling time of established FaDu tumours in nude mice by factors of 2.6 when given over 15 days (p<0.001) and 3.7 when applied over 6 weeks (p<0.001). When given simultaneously to fractionated irradiation, growth delay was significantly prolonged by an average of 33 days (p=0.003). Local tumour control was not improved by BIBX1382BS. The radiation doses necessary to control 50% of the tumours locally were 63.6 Gy (95% confidence interval 55; 73) for irradiation alone and 67.8 Gy (60; 77) for the combined treatment (p=0.5).

CONCLUSIONS

Despite clear antiproliferative activity in rapidly repopulating FaDu human squamous cell carcinoma and significantly increased tumour growth delay when combined with fractionated irradiation, local tumour control was not improved by BIBX1382BS. The results do not disprove that epidermal growth factor receptor inhibition might enhance the results of radiotherapy. However, the results imply that further preclinical investigations using relevant treatment schedules and appropriate endpoints are necessary to explore the mechanisms of action and efficacy of such combinations.

Differentiation status of human squamous cell carcinoma xenografts does not appear to correlate with the repopulation capacity of clonogenic tumour cells during fractionated irradiation

PURPOSE

To investigate the magnitude and kinetics of repopulation in a moderately well differentiated UT-SCC-14 human squamous cell carcinoma [hSCC] in nude mice. This question is of interest because clinical data indicate a higher repopulation capacity in those SCC that have preserved characteristics of differentiation, which appears to be in contrast to results on FaDu and GL hSCC previously reported from this laboratory.

METHODS AND MATERIALS

UT-SCC-14 tumours were transplanted subcutaneously into the right hind leg of NMRI nu/nu mice. Fractionated radiation treatments were delivered, either under clamped hypoxia at 5.4 Gy/fraction or under ambient conditions (consistent with an OER of 2.7). Tumours were irradiated every day, every 2nd day, or every 3rd day with 6, 12 or 18 fractions. 1, 2 or 3 days after the last fraction, graded top-up-doses under clamped conditions were given for the purpose of estimating the 50% tumour control dose (TCD50). A total of 22 TCD50 assays were performed and analysed using maximum likelihood techniques.

RESULTS

The data demonstrate a slow but significant repopulation of clonogenic cells during fractionated irradiation of UT-SCC-14 hSCC. The results under hypoxic conditions are consistent with a constant repopulation rate, with a clonogenic doubling time (Tclon) of 15.6 days (95% CI: 9.7, 21.4). This contrasts with ambient conditions where Tclon was 68.5 days (95% CI: 124, 161). Both Tclon values are longer than the 6-day volume doubling time of untreated tumours.

CONCLUSIONS

Less pronounced repopulation for irradiation under ambient compared to clamped hypoxic conditions might be explained by preferential survival of hypoxic and therefore non-proliferating clonogenic cells. Taken together with previous studies on poorly differentiated FaDu and moderately well differentiated GL hSCC, the results are consistent with considerable variability in the magnitude and kinetics of repopulation in different experimental squamous cell carcinomas, and with a relationship between reoxygenation and repopulation during fractionated irradiation. The differentiation status of hSCC growing in nude mice does not to appear to correlate with the proliferative capacity of clonogenic tumour cells during treatment. The results do not support the hypothesis gained from clinical data of higher repopulation in well-differentiated tumours.

Functional Mx protein does not prevent experimental biliary atresia in Balb/c mice

Biliary atresia (BA) is a rare cholestatic disease, which manifests itself in the form of inflammation of the liver and bile ducts in newborns, with an unknown etiology and a poor outcome. Mx proteins, which are mediators of innate, antiviral resistance induced by type I interferon, were recently detected in the livers of children with BA. Therefore, the aim of this study was to examine whether the expression of Mx protein could affect the course of experimental BA in mice. A total of 185 newborn Balb/c mice (expressing dysfunctional Mx protein) and Balb/c-Mx+-A2G mice (with functional Mx protein) were intraperitoneally infected with rhesus rotavirus (RRV) or injected with saline solution as controls. They were sacrificed if they showed signs of cholestasis or at three weeks after infection. The expression of hepatic Mx protein was detected by immunostaining (POX) and the hepatic virus load was determined. There was no significant difference in the incidence of cholestasis between wild-type Balb/c mice and Balb/c-Mx+-A2G mice (67 % vs. 65 %). However, Mx protein was highly expressed in Balb/c-Mx+-A2G mice with BA phenotype, but not in wild type Balb/c mice or disease-free Balb/c-Mx+-A2G mice despite RRV infection. The difference in the hepatic virus load was not statistically significant in mice with BA. In conclusion, Mx protein does not prevent newborn Balb/c mice from developing biliary atresia after RRV infection. However, the expression of Mx protein is independent of the hepatic virus load and could be used as a marker of BA in humans, as well as in the RRV model.

Phenotypic heterogeneity and genetic modification of P102L inherited prion disease in an international series

The largest kindred with inherited prion disease P102L, historically Gerstmann-Sträussler-Scheinker syndrome, originates from central England, with émigrés now resident in various parts of the English-speaking world. We have collected data from 84 patients in the large UK kindred and numerous small unrelated pedigrees to investigate phenotypic heterogeneity and modifying factors. This collection represents by far the largest series of P102L patients so far reported. Microsatellite and genealogical analyses of eight separate European kindreds support multiple distinct mutational events at a cytosine-phosphate diester-guanidine dinucleotide mutation hot spot. All of the smaller P102L kindreds were linked to polymorphic human prion protein gene codon 129M and were not connected by genealogy or microsatellite haplotype background to the large kindred or each other. While many present with classical Gerstmann-Sträussler-Scheinker syndrome, a slowly progressive cerebellar ataxia with later onset cognitive impairment, there is remarkable heterogeneity. A subset of patients present with prominent cognitive and psychiatric features and some have met diagnostic criteria for sporadic Creutzfeldt-Jakob disease. We show that polymorphic human prion protein gene codon 129 modifies age at onset: the earliest eight clinical onsets were all MM homozygotes and overall age at onset was 7 years earlier for MM compared with MV heterozygotes (P = 0.02). Unexpectedly, apolipoprotein E4 carriers have a delayed age of onset by 10 years (P = 0.02). We found a preponderance of female patients compared with males (54 females versus 30 males, P = 0.01), which probably relates to ascertainment bias. However, these modifiers had no impact on a semi-quantitative pathological phenotype in 10 autopsied patients. These data allow an appreciation of the range of clinical phenotype, modern imaging and molecular investigation and should inform genetic counselling of at-risk individuals, with the identification of two genetic modifiers.

ENVIRO-HIRLAM: on-line coupled modelling of urban meteorology and air pollution

Abstract. The strategy of new generation integrated Meso-Meteorological (MetM) and Atmospheric Chemical Transport (ACT) models for predicting atmospheric composition, meteorology and climate change is discussed for the Enviro-HIRLAM (HIgh Resolution Limited Area Model) integrated system. Current progress in the Enviro-HIRLAM system development and its urban on-line coupled modelling applications is considered. Results of several sensitivity studies of the urban effects (urban albedo and roughness, anthropogenic heat flux, heat island, and urban aerosols) on meteorology and air pollution at different scales are presented. Several sensitivity tests of the off-line versus on-line coupling of MetM and ACT models in Enviro-HIRLAM as well as their verification versus the ETEX experiment are considered and results are discussed.

European biliary atresia registries: summary of a symposium

Biliary atresia (BA) is a rare but potentially devastating disease. The European Biliary Atresia Registry (EBAR) was set up to improve data collection and to develop a pan-national and interdisciplinary strategy to improve clinical outcomes. From 2001 to 2005, 100 centers from 22 countries registered with EBAR via its website (www.biliary-atresia.com). In June 2006, the first meeting was held to evaluate results and launch further initiatives. During a 5-year period, 60 centers from 19 European countries and Israel sent completed registration forms for a total of 514 BA patients. Assuming the estimated incidence of BA in Europe is 1:18,000 live births, 35% of the expected 1488 patients from all EBAR participating countries were captured, suggesting that reporting arrangements need improvement. At the meeting, the cumulative evaluation of 928 BA patients including patients from other registries with variable follow-up revealed an overall survival of 78% (range from 41% to 92%), of whom 342 patients (37%) have had liver transplants. Survival with native liver ranged from 14% to 75%. There was a marked variance in reported management and outcome by country (e.g., referral patterns, timing of surgery, centralization of surgery). In conclusion, EBAR represents the first attempt at an overall evaluation of the outcome of BA from a pan-European perspective. The natural history and outcome of biliary atresia is of considerable relevance to a European population. It is essential that there is further support for a pan-European registry with coordination of clinical standards, further participation of parent support groups, and implementation of online data entry and multidisciplinary clinical and basic research projects.

Laparoscopic ureterocutaneostomy for urinary diversion in selected infants

BACKGROUND

Primary surgical correction has obviated the need for urinary diversion in many fields of pediatric obstructive and refluxive uropathy. However, a small number of children are not suitable for primary surgical correction and require temporary diversion. We present a small series of infants who underwent minimally invasive ureterocutaneostomy.

PATIENTS AND METHODS

Four infants (age 1-13 months) underwent laparoscopic ureterocutaneostomy. The indication for urinary diversion was a primary obstructive megaureter in 2 patients, deterioration of kidney function due to a posterior urethral valve in 1, and refluxive uropathy of a dysplastic single kidney in another. Laparoscopic ureteral diversion was performed using a 3 trocar technique. In 3 patients, both ureters were identified above the crossing of the iliac vessels and exteriorized through the right and left trocar incision respectively. A loop ureterocutaneostomy was performed in 3, and an end ureterocutaneostomy in 1 patient.

RESULTS

Laparoscopic ureterocutaneostomy was feasible and there were no complications in any of the infants. The mean duration of operation was 111 minutes (range 85 to 145). Isotope renography after a mean follow-up of 11 months (range 2 to 16) revealed improved renal drainage in 3 infants, while 1 required kidney transplantation due to progressive renal insufficiency.

CONCLUSIONS

Laparoscopic ureterocutaneostomy in infants is feasible. It may be considered in a selected group of patients with obstructive or refluxive uropathy in whom urinary diversion is required.

Early predictors of success of Kasai operation in children with biliary atresia

AIM

Aim of the study was the evaluation of early predictive parameters of event-free survival (not listed for liver transplantation, not transplanted, no death) in children suffering from biliary atresia after hepatoportoenterostomy (Kasai procedure) in order to optimize pretransplant management.

PATIENTS AND METHODS

Sixty-seven infants were treated with the Kasai operation at our institution over a 20-year period from 1978 until 1998. Median age at time of operation was 51 days after birth (range 19 - 180 days). Of these 67 infants, 24 children with complete datasets and an observation time of at least one year were evaluated retrospectively using a Cox regression model. The response variable was event-free survival after a median observation time of 4.9 years (1.11- 10.37 years). Six variables were entered as covariates: alanine aminotransferase (ALAT), cholinesterase activity, bilirubin, age at the time of Kasai operation and tracer excretion and uptake during hepatobiliary scintigraphy (HBSS). All variables were evaluated six weeks after operation. For subsequent cut-off determination, a receiver operating analysis (ROC analysis) was carried out.

RESULTS

Tracer excretion shown by HBSS showed the highest prognostic power to predict event-free survival after Kasai operation (log rank 18.68, p < 0.0001) followed by bilirubin and ALAT as further significant parameters in the first univariate step of the Cox regression model. In the subsequent multivariate step, the prognostic power of HBSS was improved only by bilirubin (log rank 24.6, p < 0.0001). The ROC analysis determined a cut-off for bilirubin concentrations of 57 micromol/l for event-free survival with a sensitivity of 80 % and a specificity of 78.6 %. The five-year event-free survival-rate was 100 % in the group with good tracer excretion and a bilirubin concentration of 57 micromol/l and 27 % for the other group (log rank test, p < 0. 0001).

CONCLUSION

Early predictors of success of the Kasai operation in children with biliary atresia are free tracer excretion as shown by HBSS and a serum bilirubin concentration < 57 micromol/l six weeks after the operation. Thus, children with bilirubin concentrations above this level should be carefully and frequently monitored with regard to a transplantation requirement in order to optimize pretransplant management.

Efficient angular dispersion compensation in holographic generation of intense ultrashort paraxial beam modes

We experimentally demonstrate that small misalignments of the pulse stretcher or compressor of our chirped-pulse-amplification laser can precompensate for angular chirp when producing ultrashort paraxial beam modes with holographic gratings. Using this approach we can eliminate one of the two gratings needed in our 2f-2f setup [Mariyenko, Opt. Express 13, 7599 (2005)]. This allows for up to an order of magnitude more output power. We see our method as the next step in the production of intense exotic forms of ultrashort pulses, which can be used in the investigation of intense laser-matter interactions. In addition, we produce the first femtosecond (helical-)Ince-Gaussian beams.

Surgery for biliary atresia--is there a European consensus?

Initial surgical therapy of biliary atresia (BA) consists of the radical excision of extrahepatic remnants and portoenterostomy. However, despite this procedure, which was introduced by Kasai, BA remains the commonest indication for paediatric liver transplantation. The goal of the work group on the technical aspects of Kasai portoenterostomy procedures during the European Biliary Atresia Registry Conference 2007 was to achieve consensus on various operative and perioperative aspects relevant for paediatric surgeons. Although there is still disagreement regarding some of the technical details of the Kasai operation, a remarkable consensus has emerged in most areas of the actual surgery. No consensus was achieved on the role of postoperative drainage, the routine application of steroids, the use of oral prophylactic antibiotics, and the treatment of postoperative cholangitis. Nevertheless, the wide variation in reported results, which was a feature of this conference, suggests that there are still areas where improvement in outcomes can be anticipated by changes in technique or practice.

Control of functional mRNA stability in bacteria: multiple mechanisms of nucleolytic and non-nucleolytic inactivation

Messenger RNA in bacteria may be inactivated by several parallel mechanisms acting independently on different target sites. For any species of mRNA the overall rate of inactivation is determined by the sum of the contributions from the different mechanisms. Transcripts may be inactivated directly by endonucleolytic attack or by processive nucleolytic degradation, which may proceed in the 3'-5' direction and probably also in the 5'-3' direction. Moreover, the functional lifetime of many mRNAs may be determined by processes that are not nucleolytic, such as the binding of translational repressors or the formation of secondary structures which prevent initiation of translation. These non-nucleolytic processes may also determine the chemical stability as chemical degradation frequently appears to be closely coupled to functional inactivation. The relative importance of the different mechanisms in the inactivation of bulk cellular mRNA, as well as the general prospects for engineering of stable mRNAs are discussed.

Impact of prior surgery on the feasibility of laparoscopic surgery for children: a prospective study

BACKGROUND

This study aimed to determine the impact of prior surgery on the feasibility of laparoscopic surgery for children.

METHODS

A prospective study analyzed 471 consecutive children who underwent laparoscopic surgery over a 4-year period. Laparoscopic procedures were classified "easy," "difficult," or "demanding." The end points of the study were conversion rate, intraoperative events, and duration of operation.

RESULTS

A total of 89 patients (19%) had undergone previous abdominal surgery. The conversion rate was 18% for the patients with prior surgery versus 9% for those without a prior operation (16/89 vs 35/382; p < 0.05). This difference reflects a significantly higher conversion rate for "easy" procedures among patients with than among those without prior surgery, but not for "difficult" and "demanding" procedures. The type of prior surgery had no significant impact on the mean duration of the operation. Of 71 procedures, 12 (17%) after prior conventional surgery were converted, as compared with 4 (22%) of 18 after prior laparoscopy (p > 0.05). Intraoperative events, mainly attributable to adhesions and lack of overview, occurred in 8% of patients with prior procedures, as compared with 2% without former surgery (7/89 vs 9/382; p < 0.05). Relevant complications were not significantly more frequent after prior surgery. The incidence of conversions decreased with increased time between current and previous surgery. It was 64% for surgeries less than 1 year later, 25% for surgeries 1 to 5 years later, and 5% for surgeries more than 5 years later (7/11 vs 6/24 vs 3/54; p < 0.001).

CONCLUSIONS

Prior surgery has a limited impact on the feasibility of laparoscopic surgery for children. The conversion rate and the incidence of intraoperative events, mainly because of adhesions and lack of overviewing, is increased, but not the incidence of relevant complications. The feasibility improves considerably with increased time between surgery and prior surgery. The authors consider laparoscopy to be the first-choice technique after prior surgery.

Laparoscopic nephroureterectomy in children: a prospective study on Ligasure versus Clip/Ligation

PURPOSE

The present study was performed to compare dissection of the renal hilar vessels in laparoscopic transabdominal nephrectomy in children using the Endo-Ligasure vessel sealing system versus clip/ligation.

PATIENTS AND METHODS

In a prospective and comparative study carried out from February 2003 to April 2004, 10 consecutive patients (group 1) underwent laparoscopic transabdominal nephroureterectomy using clips or intracorporeally performed ligations, respectively. From April 2004 to April 2005, 10 consecutive patients (group 2) underwent the same procedure using the Endo-Ligasure vessel sealing system. Indications for surgery were confirmed non-functioning kidneys secondary to benign unilateral renal disease and no prior surgery. The age and underlying disease distribution and the affected side were not significantly different between the two groups.

RESULTS

The operating time was significantly lower in the Endo-Ligasure group (group 1: median 167 vs. group 2: 108 min, p < 0.05). Bleeding of the renal artery occurred due to dislocation of a suture ligation, which was treated laparoscopically with an intracorporeal suture ligation. Blood loss was negligible in all patients. All procedures were completed laparoscopically and recovery was uneventful.

CONCLUSIONS

Endo-Ligasure is a beneficial tool in laparoscopic transabdominal nephrectomy. It is safe, effective, and reduces operating times compared to clip application and intracorporeal suturing.

Minimally invasive repair of pectus excavatum - shifting the paradigm?

PURPOSE

The "minimally invasive repair of pectus excavatum" (MIRPE) has increasingly become the standard operation for the repair of pectus excavatum. The aim of the present study was to report on our first-line postoperative results, including a survey of patients and to elucidate the acceptance of MIRPE.

PATIENTS AND METHODS

All MIRPE patients, who were operated on between 2000 and 2004 in our departments, were included in a retrospective study. In 2002, a retrospective questioning of 57 patients was initiated by sending identical questionnaires separately to both the patients and their parents asking for individual reasons for choosing and/or agreeing to MIRPE.

RESULTS

Complications were seen in 25 out of 84 MIRPE patients (mean 14 years, range from 5 to 20 years), but most of them were minor. Removal of the bar was necessary in 6 cases, due to bar displacement, secondary haematothorax, pericardial effusion, and local infection, respectively. No major complications occurred in the age group between 9 and 14 years. More than 90 % of the patients and their parents were satisfied or highly satisfied with the MIRPE procedure.

CONCLUSION

General and specific complications are similar to other series and they decrease with the surgeon's experience. The most severe problem, occurring in older patients, is how to avoid dislocation of the pectus bar. In the light of the complication rate, the acceptance of MIRPE is still high, especially in adolescents and young adults who had refused operation with the open techniques. In this way, a shifting of a paradigm is taking place.

[Structure quality assurance in in-patient medical rehabilitation of children and adolescents]

BACKGROUND

So far, the routine programmes of the statutory pension and health insurance institutes for quality assurance in medical rehabilitation have not included facilities for children and adolescents. Thus, a conjoint project of the statutory pension and health insurance institutes to assess and to describe the structure quality of in-patient medical rehabilitation clinics for children and adolescents was initiated. The aim of the project was a survey and an analysis of the currently existing clinic structures and the development of criteria for an evaluation of the structure quality. The Institute of Medical Psychology, University of Hamburg and the Department of Quality Management and Social Medicine, University of Freiburg were engaged to conduct the project.

METHOD

A questionnaire was developed in a multi-stage process with expert involvement which covers general information, characteristics of structure quality as well as structure affiliated process characteristics of clinics. The survey was planned as a cross-sectional study. Data collection was accomplished from 1.12.2004 - 15.3.2005.

RESULTS

A total of n = 177 facility addresses were available. The return rate was 83.3 %. Eventually, n = 79 facilities were included in the analysis. In sum, the results underline the heterogeneity of services in the field of child and adolescent rehabilitation.

CONCLUSIONS

The results allow an analysis of the current clinic structures as well as a first comparison of clinics on the basis of the assessed structure characteristics.

Laparoscopic Transabdominal Pyeloplasty in Children is Feasible Irrespective of Age

PURPOSE

We assessed the feasibility of laparoscopic transabdominal dismembered pyeloplasty in 46 infants and children with regard to patient age.

MATERIALS AND METHODS

A total of 46 consecutive infants and children (31 male and 15 female) underwent laparoscopic transabdominal dismembered pyeloplasty using a 3 to 4-trocar technique. All patients had confirmed unilateral deterioration of renal function on isotope renography. The 46 patients were divided into 3 age groups--1 to 12 months (group 1, 14 patients), 1 to 7 years (group 2, 15 patients) and 7 to 18 years (group 3, 17 patients). Followup included clinical and ultrasound assessment, and isotope renography at 3 months.

RESULTS

Laparoscopic pyeloplasty was feasible in 44 of 46 patients (96%). Mean operative time was 175 minutes (range 120 to 270). The operation was converted due to impracticality of stenting the PUJ in 1 patient, and due to bleeding in 1. Mean operative time in 44 successful laparoscopic procedures was not significantly different among the 3 age groups (171 minutes in group 1, 169 minutes in group 2 and 173 minutes in group 3). Two patients required operative intervention for PUJ leakage, and 1 underwent percutaneous nephrostomy with a further uneventful course. Mean followup was 29 months (range 3 to 86). A total of 44 patients (96%) were asymptomatic and had improved PUJ drainage on isotope renography. Two patients underwent redo pyeloplasty due to recurrent hydronephrosis at 1 month and 2 years.

CONCLUSIONS

Laparoscopic transabdominal dismembered pyeloplasty is effective and safe in infants and children. The feasibility is also excellent in patients younger than 1 year. The transabdominal approach revealed good exposition without a disadvantage for the patient.