[Lower pole pedicle in a series of 84 pyelo-ureteral junction syndromes surgically treated in children]. / Le pédicule polaire inférieur dans une série de 84 syndromes de la jonction pyélo-urétérale opérés chez l'enfant.

OBJECTIVE: To evaluate the involvement and consequences of the lower pole pedicle (LPP) associated with ureteropelvic junction syndrome. MATERIAL AND METHOD: Retrospective study in 81 children presenting a total of 84 ureteropelvic junction syndromes operated consecutively between 1994 and 1998. Urinary tract ultrasound and cystography were systematically performed. Renal scintigraphy (DTPA or MAG 3) was performed in 80 children. Preoperative intravenous urography was performed in 60 children. LPP was considered to be present when its participation in the obstruction was confirmed intraoperatively (Anderson Hynes technique with uncrossing of the vascular pedicle). RESULTS: Group I: a LPP was revealed in 24 kidneys (28.5% of cases), 17 left 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 I (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 cases in group I (8/24) and in 72% of cases in group II (43/60). Kidney function 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 observed in group II. Renal malrotation was observed in 2 cases in group I and in 12 cases in group II. Histology of the junction revealed nonspecific fibrosis in the same percentage of cases (91%) in the two groups. The mean follow-up was 15 months (range: 2 months-5 years). No surgical failure was observed. CONCLUSION: Ureteropelvic junction syndrome associated with a LPP appears to present later with recurrent low back pain in older children. It does not worsen the functional prognosis of the affected kidney. LPP can be visualized by duplex ultrasound. It may act as an inducer of obstruction by aggravating a pre-existing 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, until puberty.

Piezoelectric shockwave lithotripsy of urinary calculi: comparative study of stone depth in kidney and ureter treatments.

PURPOSE: The aim of this prospective study was to assess the relation between stone depth and the efficiency of piezoelectric extracorporeal shockwave lithotripsy (SWL). PATIENTS AND METHODS: A total of 150 patients presenting with 25 pelvic, 75 caliceal, and 25 upper and 25 lower ureteral calculi were treated using the EDAP LT02 lithotripter. All of the stones were easy to localize with sonographic and radiographic systems, and their largest diameter ranged from 4 to 25 mm (mean 8.5 mm). Renal and upper ureteral calculi were treated with the patient in the supine position and lower ureteral stones in prone position. On the basis of a meticulous stone localization and focusing, depth measurements were carried out under real-time ultrasonic guidance, the minimal distance between the cutaneous plane and the focal point being recorded only for definitely localized calculi. RESULTS: Ureteral calculi were significantly deeper than renal stones (p < 0.0001), but the distance from the cutaneous plane was statistically similar for upper and lower ureteral calculi. Stone depth was statistically affected by body mass index (BMI), patients with a BMI >25 having significantly deeper renal and ureteral calculi than subjects with a BMI < or =25 (p < 0.00001 and 0.01, respectively). Renal stones resisting SWL were significantly deeper than successfully treated calculi (p < 0.03). At the level of the ureter, the success rate after one SWL session was 85% for stones with a depth < or =110 mm and 57% for deeper stones, the difference being significant (p < 0.05). CONCLUSION: Stone depth has a significant influence on treatment outcome after piezoelectric SWL for both renal and ureteral calculi. We recommend particular attention be given to corpulent patients presenting with ureteral stones.