Kidney growth after pyeloplasty in childhood.

The postoperative increase of the renal parenchyma, measured with planimetry on repeated urography films, was studied in 24 infants and children. All patients had been operated on because of unilateral stenosis of the pelvioureteral junction. When the results were analyzed in a pair-control manner the paired members were almost identical for age at operation, affected side, sex, presenting clinical sign and length of followup. The 12 patients who underwent a dismembered pyeloplasty displayed a significantly stronger mean catch-up growth of the relative parenchymal area than the 12 patients who underwent a nondismembered technique. Speculatively, this difference may reflect in part the protection of the growing renal parenchyma by the preoperatively compliant and wide renal pelvis, which had led to resection and dismembered correction.