John E. Scoble

Renal Angioplasty in Non-atheromatous Renal Artery Stenosis: Technical Results and Clinical Outcome in 43 Patients

This study retrospectively reviewed the technical and clinical results of percutaneous transluminal renal artery angioplasty (PTRA) for non-atheromatous renal artery stenosis (RAS) in a Tertiary Renal Referral Centre. Forty-three patients (including 9 children) underwent 49 PTRA procedures for stenoses of 63 arteries over the period 1984–2001 (14 patients had bilateral stenosis treated during one procedure. There were 29 females and 14 males (age range 1–72 years, median 37 years). The etiology of the RAS was classical beaded FMD (medial fibroplasia) in 24, atypical or “variant FMD” with a more focal stenosis (intimal fibroplasia) in 11, neurofibromatosis type 1 (NF) in 7 and Takayasu’s Arteritis in 1. Five of the NF patients had angioplasty for stenoses following vascular repair procedures. A technically good result was obtained in 34/34 arteries with “classical” RAS, 9/13 atypical arteries, 11/15 arteries of NF patients and in the one Takayasu’s case. Clinical follow-up for a mean of 16 months revealed a cure rate of hypertension in classical FMD of 35% with improvement in a further 55%. In the atypical FMD cases, follow-up was obtained on 6 patients with 2 cures and the other 4 demonstrating benefit. There was a better chance of cure in younger patients. In native artery PTRA in children with NF, only 1 out of 3 patients was ‘cured’ post-PTRA, and 2 out of 3 failed. However, in postsurgical stenoses in NF patients 1 out of 4 patients was ‘cured’ and 3 out of 4 improved. In conclusion, classical FMD responds well to PTRA with better results in younger patients. Atypical FMD, especially in children and when associated with NF, is less predictable. Stenoses consequent to revascularization surgery respond well to PTRA.

Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC): compound heterozygous mutation in the claudin 16 (CLDN16) gene.

BackgroundFamilial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) is an autosomal recessive disorder of renal calcium and magnesium wasting frequently complicated by progressive chronic renal failure in childhood or adolescence.MethodsA 7 year old boy was investigated following the findings of marked renal insufficiency and nephrocalcinosis in his 18-month old sister. He too was found to have extensive nephrocalcinosis with increased fractional excretion of magnesium: 12.4% (<4%) and hypercalciuria: 5.7 mmol (< 2.5/24 hours). He had renal impairment, partial distal renal tubular acidosis and defective urinary concentrating ability. Therapy with thiazide diuretics and magnesium supplements failed to halt the progression of the disorder. Both children subsequently underwent renal transplantation. Both childrens parents are unaffected and there is one unaffected sibling.ResultsMutation analysis revealed 2 heterozygous mutations in the claudin 16 gene (CLDN16) in both affected siblings; one missense mutation in exon 4: C646T which results in an amino acid change Arg216Cys in the second extracellular loop of CLDN16 and loss of function of the protein and a donor splice site mutation which changes intron 4 consensus splice site from GT to TT resulting in decreased splice efficiency and the formation of a truncated protein with loss of 64 amino acids in the second extracellular loop.ConclusionThe mutations in CLDN16 in this kindred affect the second extra-cellular loop of claudin 16. The clinical course and molecular findings suggest complete loss of function of the protein in the 2 affected cases and highlight the case for molecular diagnosis in individuals with FHHNC.

Psychological intervention in fluid management

BACKGROUNDnHemodialysis is a palliative treatment for patients with established renal failure (ERF), and volume overload is a common problem for hemodialysis patients with low urinary output. Volume overload is thought to be mostly attributable to interdialytic fluid intake by the patient and is associated with an increased symptom burden and the development of serious medical complications. Repeated episodes of volume overload may adversely affect staff-patient relationships and the perception of care in this patient population. The aim of this case series study was to evaluate the effect and experience of a psychological intervention on interdialytic weight gain in a small group of patients.nnnMETHODSnFive patients were treated. The intervention involved using techniques derived from both cognitive behavior therapy and motivational interviewing. The main outcome measures were interdialytic weight gain and patient perception of the intervention.nnnRESULTSnThree of the five patients reduced both mean interdialytic weight gain and the frequency with which they gained in excess of 3% of their dry weight during the intervention phase. The intervention was found to be acceptable to patients.nnnSIGNIFICANCE OF RESULTSnThe intervention was effective in helping three of the five patients to reduce both the frequency and the severity of volume overload, and two of these patients maintained this for at least 6 months post intervention. The intervention used actively engaged the patients and appeared to be experienced positively. The methods used to mobilize patient resources and optimize staff-patient relationships as vehicles of change are discussed. Both may have implications for treatment concordance and the perception of care delivered.