To define the most suitable approach to assess residual stone fragments after RIRS.
Ninety two patients (115 renal units) submitted to RIRS for symptomatic kidney stones > 5 mm and < 20 mm or < 15 mm in the lower calyx diagnosed by noncontrast computed tomography (NCCT) were prospectively studied. Residual fragments were assessed by endoscopic evaluation (END) at the end of the procedure and by NCCT, ultrasound (US) and Kidneys-Ureter-Bladder X-ray (KUB) performed at the 90th postoperative-day (POD). NCCT was considered the gold standard for the evaluation of residual fragments after RIRS.
90th POD NCCT resulted stone free in 74.8% (86/115), 0 - 2 mm in 8.7% (10/115) and > 2 mm residual fragments in 16.5% (19/115) renal units. Stone-free status by END at the end of RIRS was coincident to NCCT in 93.0% of the cases (40/43). There were no cases of residual fragments > 2 mm on NCCT if END resulted stone free. In all cases that END resulted residual fragments > 2 mm, US was correct according to NCCT. Neither US nor KUB were able to identify residual fragments between 0 - 2 mm. KUB had only 31.6% (6/19) sensitivity to detect residual fragments > 2 mm and did not add sensitivity or specificity to US.
In the follow-up imaging after RIRS, we suggest that if endoscopic evaluation resulted in residual fragments < 2 mm, a 90th POD NCCT should be performed. Ultrasound may be used if endoscopic evaluation showed fragments > 2 mm.
Journal of endourology. 2018 Nov 06 [Epub ahead of print]
Alexandre Danilovic, Andrea Cavalanti, Bruno Aragao Rocha, Olivier Traxer, Fabio Cesar Miranda Torricelli, Giovanni Scala Marchini, Eduardo Mazzucchi, Miguel Srougi
University of Sao Paulo Medical School, Sao Paulo, Brazil, Section of Endourology, Division of Urology São Paulo , Av. Dr. Eneas de Carvalho Aguiar, 255, 7 and. Sala 7175 , São Paulo, São Paulo, Brazil , 05403-000 ; ., Universidade de Sao Paulo Faculdade de Medicina Hospital das Clinicas, 117265, Radiology, Sao Paulo, SP, Brazil ; ., INSTITUTO DE RADIOLOGIA DO HOSPITAL DAS CLÍNICAS DA FACULDADE DE MEDICINA DA UNIVERSIDADE DE SÃO PAULO, RADIOLOGY , Rua Capote Valente 671 , SAO PAULO, SAO PAULO, Brazil , 05409002 ; ., Sorbonne Université, GRC n°20 LITHIASE RENALE, AP-HP, Hôpital Tenon, F-75020 Paris, France, Paris, France ; ., Universidade de Sao Paulo Faculdade de Medicina, 37884, Urology, Sao Paulo, SP, Brazil ; ., Hospital das Clínicas, University of Sao Paulo Medical School, Section of Endourology, Division of Urology, São Paulo, São Paulo, Brazil ; ., Hospital das Clínicas, University of Sao Paulo Medical School, Division of Urology , barata ribeiro street,490 room25 , São Paulo, São Paulo, Brazil , 01308001 ; ., University of Sao Paulo Medical School, Urology, Sao Paulo, Sao Paulo, Brazil ; .