Diagnostic cyst puncture of multicystic kidney in neonates.

In the neonatal period it is important to differentiate hydronephrosis from cystic disease of the kidney, since treatment of these entities differ. Early surgery in hydronephrosis may be indicated to salvage kidney function. We studied a group of 29 infants with renal cysts or hydronephrosis. In 10 cases some doubt about diagnosis remained after thorough diagnostic imaging. These infants were examined using percutaneous puncture of the kidney to verify the suspected diagnosis of multicystic renal disease. The studies were performed using local anesthesia and sedation. Ultrasonography was used for puncture and contrast medium was injected during fluoroscopy. The cysts communicated in 7 out of 10 cases, and a true renal pelvis was never seen. Irregular tubular structures joining the cysts were identified in 7 cases and seem to be characteristic of the multicystic dysplastic kidney. One instance of the hydronephrotic type of multicystic kidney was found at surgery. Large size of the cysts can make diagnosis difficult. Percutaneous puncture was successful and gave the diagnosis in all cases. No complications ensued.