Vol. 183, No. 4, Supplement, Sunday, May 30, 2010
METHODS: This is a retrospective single institution review of consecutive hypertensive patients with unilateral renal parenchymal disease who underwent nephrectomy. Preoperative characteristics such as blood pressure, medications, laboratory values, renal imaging, time of diagnosis, age, and cause of renal disease were tabulated as were postoperative data including blood pressure, medications, complications, laboratory values, and time to normalization of blood pressure. RESULTS: Out of 159 nephrectomies from July 2002 to August 2009, 21 met inclusion criteria with follow-up blood pressure measurements. The average age of the patients was 3.5 yrs (range 2.1 mo – 11.8 yrs) and average follow up was 17.8 months (range 1 – 36 months). There were 11 patients with multicystic dysplastic kidney, 9 with reflux nephropathy, and 2 with ureteropelvic junction obstruction. Out of the 21 patients, 14 (67%) were noted to have normalization of their blood pressure postoperatively. Of the patients with MCDK, 7/11 had normal blood pressure postoperatively compared to 6/9 patients with reflux nephropathy, and 1/2 patients with UPJ obstruction. Of the 14 patients with normalization of blood pressure postoperatively, 7 were on antihypertensives prior to surgery. Four of the 7 patients stopped their antihypertensive medications postoperatively, 2 decreased from 3 and 4 medications to 1, and 1 remained on an ACE inhibitor for renal protection. There were 2 patients with contralateral renal scarring, both of which did not have normalization of blood pressure postoperatively. CONCLUSIONS: Nephrectomy in pediatric patients with unilateral parenchymal renal disease and hypertension yields resolution of hypertension in 67% of cases, permitting cessation or diminution of antihypertensives in many patients. Given the alternative of life-long antihypertensives with the risk of medication non-compliance and sideeffects, nephrectomy is a logical option of care which should be offered to all such patients with informed knowledge of potential for cure. Source of Funding: None
448 LIGATION OF THE NATIVE URETER AS AN ALTERNATIVE TO NEPHRECTOMY IN PEDIATRIC RENAL TRANSPLANTATION Nicola Capozza*, Giovanni Torino, Giuseppe Collura, Paolo Caione, Rome, Italy INTRODUCTION AND OBJECTIVES: Native nephrectomy before or during transplantation has some indications in pediatric recipients, including intractable hypertension, polyuria, intractable massive proteinuria, recurrent renal infections and in very young patients. Another indication for nephrectomy is the need of native ureter for urinary tract reconstruction, although ureteroneocystostomy is the primary techniques. We describe our experience about intentional ligation of native ureter as an alternative to nephrectomy in pediatric renal transplant recipients. METHODS: Between January and October 2009, 22 pediatric renal transplants were performed. In 8 (36 %) patients (age range, 8 to 18 years; mean age, 11,6 years), a native ipsilateral nephrectomy was planned for intractable hypertension (2 pts), polyuria (3 pts), intractable massive proteinuria (1 pt), recurrent renal infections (1 pt) and irreparable lesion of the graft ureter (1 pt). All 8 patients (planned for a native nephrectomy) underwent native ureteral ligation without native nephrectomy. Follow-up ranged 1 to 9 months (mean, 4,1 months) and consisted in periodic evaluation for flank pain, renal ultrasound and doppler, urinalysis and blood pressure. RESULTS: None patients with native ureteral ligation required secondary nephrectomy. Postoperative doppler scan at 72 hours showed a decrease of blood flow to the native kidney and at 1 week absence of renal blood supply. At 8-12 weeks the ultrasound showed a complete renal atrophy. None patients had pyelonephritis or pain during follow-up period. Hypertension was not noticed.
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CONCLUSIONS: The intentional ligation of the native ureter without native nephrectomy in pediatric renal transplant recipients is safe, effective and it represents a mininvasive alternative to surgical nephrectomy. Source of Funding: None
449 CHILDREN WITH UROLOGICAL DISORDERS IN THE CHRONIC KIDNEY DISEASE IN CHILDREN (CKID) COHORT: CLINICAL CHARACTERISTICS AND ESTIMATION OF GFR Jennifer Dodson*, Judith Jerry-Fluker, Derek Ng, Baltimore, MD; Bradley Warady, Kansas City, MO; Susan Furth, Baltimore, MD INTRODUCTION AND OBJECTIVES: Structural urological disease is the most common cause of pediatric chronic kidney disease. We assessed the accuracy of formulas to estimate level of kidney function in children with urological disorders in the CKiD cohort. METHODS: The CKiD study is a prospective, observational cohort of children recruited from 47 sites in the US and Canada. Eligibility requirements include age 1 to 16 yr and estimated glomerular filtration rate (GFR) via Schwartz formula (kHt(cm)/Scr) 30 to 90 ml/ min/1.73 m2. Baseline demographics, clinical variables, GFR, and physical examination were assessed at study entry. A cross-sectional analysis of children was performed using non-parametric methods for continuous variables and Fisher’s exact test for categorical variables. We compared estimated to measured GFR using linear regression. RESULTS: 575 participants had ⱖ1 measure of GFR and 60% had an underlying urological diagnosis: obstructive uropathy (n⫽116), aplastic/hypoplastic/dysplastic kidneys (n⫽103), reflux nephropathy (n⫽86), prune belly (n⫽11), and other (n⫽27). Among these, the median age was 9yrs and duration of CKD 7yrs. 85% (n⫽287) had seen a urologist at median age ⬍1yr, and 70% (n⫽234) had undergone a urological procedure. Most diagnoses were by ultrasound (97%) and VCUG (74%). Compared to children with other causes of kidney disease, those with underlying urological disorders were predominantly male (67% vs. 54%, p⬍0.01), Caucasian (68% vs. 65%, p⫽0.05), younger at onset of kidney disease (⬍1 vs. 5 years, p⬍0.01), premature (15% vs. 11 %, p⫽0.05), low birth weight (21% vs 16%, p⫽0.03), and in a lower weight percentile (39th vs. 54th, ⬍0.01). Mean GFR measured by iohexol plasma disappearance for children with urological disorders was 46.6 ml/min/1.73m2. Mean estimated GFR by the Schwartz formula was 64.2 (bias⫽37% (95% CI: 33%, 40%, p⬍0.001)). Mean estimated GFR by the CKiD equation (includes Cr and cystatin) was 44.8, (bias⫽-2.7% (95% CI: -4.7%,-1%, p⫽0.009). Mean estimated GFR by the Filler equation (includes cystatin C) was 42.6 (bias⫽-2.1% (95% CI: -5, 1.0, p⫽0.19). CONCLUSIONS: Underlying urological causes of CKD are present in 60% of participants in the CKiD study. These children were diagnosed earlier and were more likely than other participants to have been premature, low birth weight and to have growth delay. GFR was systematically over-estimated by the Schwartz equation, while the CKiD estimating equation and the Filler equation based on cystatin C levels were more accurate in estimating GFR in this population. Source of Funding: Supported by the National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Neurological Disorders and Stroke, National Institute of Child Health and Human Development, and National Heart, Lung and Blood Institute Grants UO1-DK-66143, UO1-DK- 66174 and UO1-DK-66116, National Institute of Diabetes and Digestive and Kidney Diseases Grant 1K23DK078671 (JLD), and a National Kidney Foundation of Maryland Professional Development Award (JLD).