Dincel N et al, 2013: Are small residual stone fragments really insignificant in children?
Dincel N, Resorlu B, Unsal A, Tepeler A, Silay MS, Armağan A, Diri A, Sancaktutar AA, Ziypak T, Mir S
Department of Pediatric Nephrology, Ege University, Faculty of Medicine, Izmir, Turkey
OBJECTIVES: To assess the significance of asymptomatic residual stone fragments of less than 4mm (clinically insignificant residual fragments [CIRFs]) after shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PNL), and retrograde intrarenal surgery (RIRS) in children.
PATIENTS AND METHODS: Eighty-five children were followed up for 6 to 50months (median 22). Outcomes measured were fragment re-growth, stone events (emergency department visits, hospitalization, or additional interventions) and spontaneous fragment passage.
RESULTS: During follow-up, 22 children (25.8%) passed residual fragments spontaneously. Highest spontaneous passage rate was found for renal pelvis stones and the lowest for the lower pole stones (57.1% vs. 16.1%; p<0.001). When the number of the fragments increased, the chance of the spontaneous passage decreased (30% vs 20%; p<0.05). Symptomatic episodes including renal colic, hematuria, or urinary tract infection were documented in 34 (40%) patients, and re-growth of fragments was observed in 18 (21.2%). Stone size had no significant effect on spontaneous passage (p=0.079), stone growth (p=0.528), and symptomatic episodes (p=0.402). Twenty-five patients (29.4%) required secondary intervention for stone re-growth or stone related events and the remaining 20 patients (23.5%) needed medical treatment for bothersome symptoms or complications.
CONCLUSIONS: Our results suggest that 40% of children with CIRFs will become symptomatic and 20% will develop stone re-growth over the following 6months. Only one fifth of the fragments will pass spontaneously without any complications. Therefore, the use of the term "CIRF" is not appropriate for postoperative residual fragments in children.
J Pediatr Surg. 2013 Apr;48(4):840-4. doi: 10.1016/j.jpedsurg.2012.07.061.
PMID:23583144[PubMed - in process]
The authors discuss in this article the relevance of the term CIRF. This issue is in no way new and has been a matter of debate as long as we have had access to SWL. But it needs to mention that residuals are seen after all kinds of stone removal.
The new information is the authors´ experience of this problem in children. The analysis does not discriminate between those with residuals after SWL (49), RIRS (10) or PNL(26). The authors conclude – like in similar studies in adults – that the term CIRF is inappropriate also for children. It is of note, however, that 26% passed their residual fragments/stones spontaneously, that re-growth was recorded in 21% and that the stone situation was stable in as many as 53%.
For those children in whom an increase in size was demonstrated, some might in fact have formed new stones and not necessarily deposited new crystalline material on residual fragments.
The importance of medical therapy is emphasized because only 13% of children given recurrence prevention showed increased stone burden, compared with 26% in children without such treatment. This observation shows that although recurrence prevention is important for most patients with stone disease such a step is particularly important for children in order to counteract re-growth as well as new stone formation.