Purpose: We evaluated the use of renal ultrasound for monitoring pyelocaliectasis after pyeloplasty in children.
Materials and methods: Changes in pyelocaliceal dilatation following pyeloplasty were assessed by serial ultrasound. Of 104 children 0 to 12 years old who underwent pyeloplasty between 1982 and 1992, 44 (47 renal units) were monitored with serial ultrasound for at least 2 years (range 2 to 9, mean 3.8). Patient ages at pyeloplasty were 0 to 3 months (17), 4 to 12 months (8), 1 to 6 years (13) and 7 to 12 years (6). Preoperative and postoperative ultrasound was reviewed by a single pediatric radiologist blinded to the date of surgery. The degree of pyelocaliectasis was graded as 0 to 4 according to the classification of the Society for Fetal Urology.
Results: Preoperative ultrasound revealed grade 4 pyelocaliectasis in 26 kidneys (55%) and grade 3 disease in 21 (45%). Grade was the same or worse 1 month after pyeloplasty in the majority of kidneys (92%) studied at this interval. Of the 47 renal units assessed 43 (91%) showed improvement in pyelocaliectasis during postoperative followup. Only 38% of the kidneys improved during the first 6 months of followup, while 81% were improved 2 years postoperatively. Improvement to grade 0 or 1 dilatation occurred in only 9 kidneys (19%). The rate of resolution of pyelocaliectasis was not related to preoperative grade or patient age at pyeloplasty.
Conclusions: Improvement on renal ultrasound after pyeloplasty appears to be gradual. Less than half of the patients had improvement in the initial 6 months after pyeloplasty and pyelocaliectasis rarely resolved completely. While renal ultrasound can provide an accurate and cost-effective means of monitoring children on a long-term basis after pyeloplasty, sonographic evaluation in the early postoperative period commonly shows increased or unchanged pyelocaliectasis.