The lower pole pedicle in a series of 84 operated ureteropelvic junction syndromes in children.

Objective: To evaluate the involvement and consequences of the lower pole p edicle (LPP) associated with ureteropelvic junction syndrome. Material and Method Retrospective study in 81 children presenting a total o f 84 ureteropelvic junction syndromes operated consecutively between 1994 a nd 1998. Urinary tract ultrasound and cystography were systematically perfo rmed Renal scintigraphy (DTPA or MAG 3) was performed in 80 children. Preop erative intravenous urography was performed in 60 children. LPP was conside red to be present when its participation in the obstruction was confirmed i ntraoperatively (Anderson Hynes technique with uncrossing of the vascular p edicle). Results: Group I: a LPP was revealed in 24 kidneys (28.5% of cases), 17 lef t kidneys and 7 right kidneys, in 14 boys and 10 girls, with a mean age of 4 years (range: 2 months - 14 years). Group II: 60 kidneys without LPP (71. 5% of cases), 32 left kidneys and 28 right kidneys, in 40 boys and 17 girls , with a mean age of 2 years (range: 1 month - 15 years). The most frequent presenting complaint was recurrent low back pain in 58% of cases in group 1 (14/24) and 5% of cases in group II (3/60). The mean age at diagnosis was 6 years. Hydronephrosis was detected by antenatal ultrasound in 33% of cas es in group 1 (8/24) and in 72% of cases in group II (43/60). Kidney functi on in group I was greater than 40% in 19 patients, between 20 and 39% in 2 patients and less than 20% in 2 patients. These results were not influenced by age at diagnosis and were not significantly different from those observ ed in group II. Renal malrotation was observed in 2 cases in group I and in 12 cases in group II. Histology of the function revealed nonspecific fibro sis in the same percentage of cases (91%) in the two groups. The mean follo w-up was 15 months (range: 2 months - 5 years). No surgical failure was obs erved. Conclusion: Ureteropelvic junction syndrome associated with a LPP appears t o present later with recurrent low back pain in older children. It does not worsen the functional prognosis of the affected kidney. LPP can be visuali zed by duplex ultrasound It may act as nit inducer of obstruction by aggrav ating a preexisting abnormality of the ureteropelvic junction. When LPP is associated with isolated dilatation of the pyelocaliceal cavities, the risk of subsequent decompensation requires closer ultrasound surveillance, unti l puberty.