Is peritoneal dialysis feasible after laparotomy in children? A case-control series to compare outcomes

OBJECTIVES

Peritoneal dialysis (PD) is the modality of choice for children with end-stage renal disease (ESRD) awaiting renal transplant; however, this option is sometimes avoided for those with previous laparotomy. The goal of this study was to compare the outcomes of PD in patients with and without previous laparotomy.

PATIENTS AND METHODS

Twenty-four patients who had been started on peritoneal dialysis were retrospectively analysed. Group LAP consisted of six patients with previous laparotomy, and Group NO-LAP of 18 controls with either retroperitoneal or no abdominal surgery. The percentage of theoretical maximum volume of infusion, time to reach it, complications (infection and drainage difficulties), and number of catheters needed to finish therapy were analysed.

RESULTS

The characteristics of patients and technique of insertion are presented in Table. The percentage of maximum theoretical volume of infusion was similar in both groups. Median of catheter survival was similar in both groups. Complications were divided into malfunction (slow drainage, obstruction or leak) and infection. Incidence of complications per catheter and per month of dialysis was ten times lower in Group NO-LAP. Peritoneal dialysis failed in one patient with recurrent intraperitoneal adhesions after adhesiolysis in Group LAP.

CONCLUSION

Despite a higher incidence of complications (malfunction and infections), PD remains an acceptable option after laparotomy. In this series, it was sufficient in achieving adequate filtration in five patients.

DNA copy number variants: A potentially useful predictor of early onset renal failure in boys with posterior urethral valves

INTRODUCTION

Posterior urethral valves (PUV) are among the most common urological causes of chronic kidney disease (CKD) in childhood. Recently, genomic imbalances have been cited as potential risk factors for altered kidney function and have been associated with CKD. The phenotypic effects of a copy number variant (CNV) in boys with PUV are unknown. Here, it was hypothesised that the progression to early renal failure in PUV patients may be influenced by genetic aberrations.

OBJECTIVE

To assess the relationship between CNVs and renal outcomes.

PATIENTS AND METHODS

Between September 2012 and July 2015, 45 children with PUV were recruited to evaluate the presence of CNVs in their DNA. The patients' medical records were retrospectively reviewed. The criteria for outcomes of renal function included: assessments of the nadir serum creatinine in the first year of life, the estimated glomerular filtration rate at 1 and 5 years, and the requirement for renal replacement.

RESULTS

Thirteen CNVs were identified in 12 boys (29% of the cohort). Microarray analysis revealed two pathogenic CNVs (well-established CNVs known to be associated with genetic disease) and 11 of unknown significance (CNVs with insufficient current available evidence for unequivocal determination of clinical significance), including genes that have been previously implicated in kidney diseases and urogenital disorders. The median follow-up was 10.2 years (range 3-17.5) in the group of patients with CNV compared with 5.8 years (range 1-16.6) in those CNV-. The nadir creatinine values were significantly higher in boys with CNVs than in those without CNVs (57.5 μmol/L (range 23-215) and 28 μmol/L (range 18-155), respectively (P = 0.05) (Figure). Boys CNV+ had a worse prognosis, with a higher incidence of Stage-V CKD compared with the control group (33% with CNVs vs. 9% in CNV-, P = 0.06) at a median age of 22 months (range 8 months-16 years). Four (33%) patients CNV+ underwent renal transplantation.

DISCUSSION

The role of CNVs in the deterioration of renal function remains unknown. It can be hypothesised that CNVs could be a contributing factor or may serve as an accelerant for the progression to renal failure.

CONCLUSION

The CNVs >100 Kb were significantly associated with early onset renal failure in children with PUV. Prenatal detection of CNV could help to identify foetuses at high risk of severe renal impairment in cases of suspected PUV, especially in cases without oligohydramnios or severe pulmonary hypoplasia. These preliminary results should be confirmed in a larger cohort of patients.

Urethral duplication in girls: Three cases associating an accessory epispadiac urethra and a main hypospadiac urethra

INTRODUCTION

Urethral duplication is extremely rare in girls, with less than 40 cases reported so far. Most of them present as a prepubic sinus. Literature is scare regarding aetiology, classification and management in other forms. This study presents three cases of sagittal urethral duplication in girls presenting a main hypospadiac urethra and an accessory epispadiac urethra.

PATIENTS AND METHODS

Medical records were retrospectively reviewed of three girls with urethral duplication managed over a 30-year period at a single institution. Circumstances of diagnosis, management and outcomes were analysed.

RESULTS

The oldest case presented as a neonatal retrovesical mass with an accessory clitoral stream, whereas the two more recent cases presented with antenatal hydrocolpos and bilateral ureterohydronephrosis. Cases 1 and 3 had an incomplete duplication, while Case 2 had a complete form. In Case 3, the duplication was associated with a urogenital sinus and an anteriorly placed anus. Management involved resection of the epispadiac accessory urethra to achieve continence, with dilatation and/or mobilisation of the hypospadiac one. All girls are now aged >5 years old and are continent, and one is old enough to have normal menstruation. Renal function is normal in all. The summary table presents the schematic anatomical description as shown on micturating cystourethrogram and endoscopy, as well as the management for each patient.

DISCUSSION

Step-by-step management is necessary in urethral duplication. The neonatal emergency is to release the urinary tract compression by evacuating urinary retention or hydrocolpos. Later in infancy, decision has to be taken regarding the urethras. If the resection of the epispadiac accessory urethra seems acceptable to achieve continence, the attitude towards the hypospadiac channel is more controversial and should be individualised. Embryologic and aetiopathogenic pathways are still missing to uniformly characterise the malformation.

CONCLUSION

Paediatric urologists should remember that there is a wide spectrum of urethral duplication in girls, and that various presentations exist beside the more classic prepubic sinus.

Interplay between polymer chain conformation and nanoparticle assembly in model industrial silica/rubber nanocomposites

The question of the influence of nanoparticles (NPs) on chain dimensions in polymer nanocomposites (PNCs) has been treated mainly through the fundamental way using theoretical or simulation tools and experiments on well-defined model PNCs. Here we present the first experimental study on the influence of NPs on the polymer chain conformation for PNCs designed to be as close as possible to industrial systems employed in the tire industry. PNCs are silica nanoparticles dispersed in a styrene-butadiene-rubber (SBR) matrix whose NP dispersion can be managed by NP loading with interfacial coatings or coupling additives usually employed in the manufacturing mixing process. We associated specific chain (d) labeling, and the so-called zero average contrast (ZAC) method, with SANS, in situ SANS and SAXS/TEM experiments to extract the polymer chain scattering signal at rest for non-cross linked and under stretching for cross-linked PNCs. NP loading, individual clusters or connected networks, as well as the influence of the type, the quantity of interfacial agent and the influence of the elongation rate have been evaluated on the chain conformation and on its related deformation. We clearly distinguish the situations where the silica is perfectly matched from those with unperfected matching by direct comparison of SANS and SAXS structure factors. Whatever the silica matching situation, the additive type and quantity and the filler content, there is no significant change in the polymer dimension for NP loading up to 15% v/v within a range of 5%. One can see an extra scattering contribution at low Q, as often encountered, enhanced for non-perfect silica matching but also visible for perfect filler matching. This contribution can be qualitatively attributed to specific h or d chain adsorption on the NP surface inside the NP cluster that modifies the average scattering neutron contrast of the silica cluster. Under elongation, NPs act as additional cross-linking junctions preventing chain relaxation and giving a deformation of the chain with the NP closer to a theoretical phantom network prediction than a pure matrix.

[Clinical and biochemical characterization of childhood urolithiasis]

OBJECTIVES

Urolithiasis is rare in children, but the incidence has increased over the past few decades. This study aims at describing the clinical and biochemical characteristics, etiology, and treatment of urolithiasis in children.

METHODS

This was a retrospective study of all children under 16 years of age seen at the Bordeaux University Children's Hospital with a diagnosis of urolithiasis. The diagnosis was confirmed either radiologically or clinically by the expulsion of the stone.

RESULTS

A total of 186 children with a diagnosis of urolithiasis between 1994 and 2012 were included. The median age at diagnosis was 7.4 years. The male-to-female ratio was 1.9. The estimated annual incidence was around 5.5/100,000 children under 15 years of age in the past 5 years. The main presenting feature was nonspecific abdominal pain (71%). Metabolic calculi accounted for 48% of the patients with idiopathic hypercalciuria as the main cause. Genetic diseases accounted for 15% of cases. The proportion of infectious calculi was estimated at 33% and decreased in the past two decades. Stone fragments were sent for analysis in 86 children, and calcium oxalate was the major component (37%), followed by calcium phosphate (33%), purine (9%), and struvite (8%). At least 26% of patients experienced recurrence of stone passage.

CONCLUSION

This retrospective study highlighted changes in characteristics of pediatric urolithiasis over time. Childhood-onset urolithiasis requires complete etiological work-up so that a metabolic cause with a high risk of recurrence does not go unrecognized.

Proximal humerus fractures in children and adolescents

Proximal humerus fractures are rare in paediatric traumatology. Metaphyseal fractures account for about 70% of cases and epiphyseal separation for the remaining 30%. The development and anatomy of the proximal humerus explain the various fracture types, displacements, and potential complications; and also help in interpreting the radiographic findings, most notably in young children. Physicians should be alert to the possibility of an underlying lesion or pathological fracture requiring appropriate diagnostic investigations, and they should consider child abuse in very young paediatric patients. Although the management of proximal humerus fractures remains controversial, the extraordinary remodelling potential of the proximal humerus in skeletally immature patients often allows non-operative treatment without prior reduction. When the displacement exceeds the remodelling potential suggested by the extent of impaction, angulation, and patient age, retrograde elastic stable intramedullary nailing (ESIN) provides effective stabilisation. As a result, the thoraco-brachial abduction cast is less often used, although this method remains a valid option. Retrograde ESIN must be performed by a surgeon who is thoroughly conversant with the fundamental underlying principles. Direct percutaneous pinning is a fall-back option when the surgeon's experience with ESIN is insufficient. Finally, open reduction is very rarely required and should be reserved for severely displaced fractures after failure of closed reduction. When these indications are followed, long-term outcomes are usually excellent, with prompt resumption of previous activities and a low rate of residual abnormalities.