Christophe Almeras 1 1 Department of Urology, La Croix du Sud Clinic, 52 chemin de Ribaute, 31130, Quint Fonsegrives, France; , Michel Daudon 2 2 Unit of Functional Explorations, Tenon Hospital, Pierre and Marie Curie University, Paris, France; , Vincent Estrade 3 3 Department of Urology, Hospital, Angoulême, France; , Jean Romain Gautier 4 4 Department of Urology, La Croix du Sud Clinic, 52 chemin de Ribaute, 31130, Quint Fonsegrives, France; , Olivier Traxer 5 5 Department of Urology, Tenon Hospital, Pierre and Marie Curie University, Paris, France; , Paul Meria 6 6 Department of Urology, Saint-Louis Hospital, Denis Diderot University, Paris, France.
World J Urol. 2021 Jan;39(1):177-185.
COMMENT
Endoscopic view of the collecting system provides the chance to observe many abnormalities that could be correlated to urinary stone formation. Papillary calculi result from subepithelial lesions (11 Randall A. The origin and growth of renal calculi. Ann Surg. 1937;105:1009-27.). Therefore, the observation of papillary abnormalities could help to understand lithogenesis and eventually help the management of patient's treatment.
Almeras et al. reported the endoscopic evaluation of renal papillae during 88 consecutive flexible ureteroscopies based on the 2016 proposed classification (22 Almeras C, Daudon M, Estrade V, Gautier JR, Traxer O, Meria P. Classification of the renal papillary abnormalities by flexible ureteroscopy: evaluation of the 2016 version and update. World J Urol. 2021;39:177-85.). This classification was inspired on the oncologic TNM classification. It included stone description (Sx), number and type of papillary abnormality (nPx) and the amount of Randall's plaque (Rx) (33 Almeras C, Daudon M, Ploussard G, Gautier JR, Traxer O, Meria P. Endoscopic description of renal papillary abnormalities in stone disease by flexible ureteroscopy: a proposed classification of severity and type. World J Urol. 2016;34:1575-82.). The present study updated the former classification to new SxnPxDrx/i/px, including mixed type of stone, excluding subepithelial stones, including papillary abnormalities of medullary sponge kidney and including description of deposits (D) of the amount of Randall's plaque (r), intrapapillary deposits (i) and intraductal plugs (p). Main findings were that 83% of the patients had Randall plaques and only 4.5% of the patients had no abnormalities. Erosions were present in 55.7%, anchored stones in 30.7%, intraductal crystallization in 15.9% and extrophic papillae in 8%. The description of the renal papillae showed clinical importance because it was correlated to the diagnosis of a metabolic lithogenesis. High amount of Randall's plaque was associated with dark anchored stones (Sa1). Calcium phosphate stones were correlated to intraductal crystallization (Sc) and hypercalciuria was higher in light anchored stones (Sa2) than dark anchored stones (Sa1).
As endoscopic surgeons, we should seize the opportunity to use the endoscopic view not only to treat the already formed stones but also to help patients with the diagnosis of the cause of stone formation. The proposed classification by Almeras et al. seems to be too complex to be adopted by urological community and should be validated by other investigators to be recommended but it is the most embracing endoscopic classification so far.
REFERENCES
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1Randall A. The origin and growth of renal calculi. Ann Surg. 1937;105:1009-27.
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2Almeras C, Daudon M, Estrade V, Gautier JR, Traxer O, Meria P. Classification of the renal papillary abnormalities by flexible ureteroscopy: evaluation of the 2016 version and update. World J Urol. 2021;39:177-85.
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3Almeras C, Daudon M, Ploussard G, Gautier JR, Traxer O, Meria P. Endoscopic description of renal papillary abnormalities in stone disease by flexible ureteroscopy: a proposed classification of severity and type. World J Urol. 2016;34:1575-82.
Publication Dates
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Publication in this collection
11 Mar 2022 -
Date of issue
Mar-Apr 2022
