Post-renal transplant urolithiasis in children: an increasingly diagnosed complication: a retrospective cohort study.

OBJECTIVE: Urolithiasis in renal transplant (RTx) recipients is a potential cause of allograft loss if obstruction is untreated. It is not clear if paediatric transplant recipients are following the global trend for increased prevalence of urolithiasis over time. DESIGN/SETTING/PATIENTS: A retrospective chart review was undertaken to evaluate the frequency, risk factors and characteristics of post-RTx urolithiasis over two decades (1995-2016), in a tertiary Australian paediatric hospital. RESULTS: Stones were diagnosed in 8 of 142 (5.6%) recipients, 6 of whom were transplanted in the latter decade. All patients were male, with a median age 4.9 years and median weight 11.8 kg. Presentation was with haematuria (n=4), pain (n=2), dysuria (n=2), stone passage (n=1) and asymptomatic (n=1). Time to presentation was bimodal; three stones were identified in the initial 3 months post RTx and the remainder after 31-53 months. Two stones were in association with retained suture material and two patients had recurrent urinary tract infections. The average stone size was 8.4 mm. Five stones were analysed; all contained calcium oxalate, three were mixed, including one with uric acid. Five (83.3%) children had hypercalciuria but none had hypercalcaemia. Cystolithotripsy was the the most common treatment (n=5), in combination with citrate supplementation. No graft was lost due to stones. CONCLUSIONS: Calculi occur with increasing frequency after renal transplantation. Clinicians need a high index of suspicion as symptoms may be atypical in this population. The cause for the increased frequency of stones in transplant recipients is not clear but is in keeping with the increase seen in the general paediatric population.

Intra-abdominal Complications After Pediatric Kidney Transplantation: Incidence and Risk Factors.

BACKGROUND: The incidence and types of intra-abdominal complications after pediatric transplantation are not well established, and specific risk groups have not been clearly identified. METHODS: A retrospective chart review of all pediatric transplant recipients between 1995 and 2016 was undertaken. Intra-abdominal complications were grouped into 4 categories: fluid collections, gastrointestinal, vascular, and urogenital. Donor, recipient, and transplant characteristics were evaluated using univariate and multivariate logistic regressions. RESULTS: There were 146 transplants meeting the inclusion criteria. The mean follow-up time was 4.6 ± 3.7 years (range, 0.3-18 y). The mean weight at transplantation was 31.5 ± 16.5 kg (range, 9-78), with 24 (16%) recipients being <15 kg and 23% younger than 5 years. Thirty-four (23%) patients had previous abdominal surgery. There were 32 complications identified in 27 (18%) transplant recipients. Fluid collections requiring surgical drainage developed in 9 (6.2%), gastrointestinal surgical complications in 12 (8.2%), vascular complications in 5 (3.5%), and urogenital complications in 6 (4.1%). There were only 3 graft losses due to abdominal complications, all after renal vein thrombosis. Weight <15 kg at the time of transplant (P = 0.016), previous abdominal surgery (P = 0.047), and intraperitoneal surgical technique (P = 0.008) were risk factors in the univariate analysis using Cox regression models, whereas only weight <15 kg (P = 0.003) and previous abdominal surgery (P = 0.008) were retained in the multivariate analysis. CONCLUSIONS: Intraabdominal complications occur in almost 1 in 5 pediatric renal transplant recipients. Weight <15 kg and previous abdominal surgery are risk factors for developing such complications.

Pediatric Vasculitis.

Vasculitis is defined as inflammation of the blood vessels and can result in stenosis or aneurysm, which may in turn lead to occlusion or rupture of the vessel compromising tissue perfusion. The manifestations of these diseases depend on the size and site of the vessels effected. Vasculitis can be secondary to numerous inflammatory and infectious diseases but this review will concentrate on the systemic primary vasculitides and aims to discuss the presentations and approaches to management of a number of these conditions.