Introduction: Evaluation of possible residual fragments after percutaneous nephrolithotomy is an essential aspect of the management of stone disease. The results of this evaluation determine the therapeutic approach, follow-up and presumed duration of treatment. The imaging modalities most frequently used are non-enhanced spiral computed tomography and plain abdominal x-ray. The objective of this study was to evaluate the contribution of spiral CT to the immediate follow-up of percutaneous nephrolithotomy.
Material and methods: Over a period of two years, we prospectively included 50 patients in whom plain abdominal x-ray and spiral CT were performed on the first postoperative day after percutaneous nephrolithotomy. The diagnosis of residual fragments was based on these examinations by 2 independent radiologists.
Results: The sensitivity for the detection of residual fragments was 87% for plain abdominal x-ray compared 100% for computed tomography. 89% of the fragments not diagnosed by plain abdominal x-ray were less than 5 min.
Conclusion: Plain abdominal x-ray was insufficient for the diagnosis of small residual fragments. Spiral CT is justified to confirm the absence of residual fragments in a patient after percutaneous nephrolithotomy despite the higher cost and irradiation compared to plain abdominal x-ray.