Staghorn classification: Platform for morphometry assessment

Abstract

Introduction: The majority of staghorn classifications do not incorporate volumetric stone burden assessment. Accurate volumetric data can easily be acquired with the ever-increasingly available computerized tomography (CT) scan. This manuscript reviews the available staghorn stone classifications and rationalizes the morphometry-based classification.

Materials and methods: A Pubmed search was performed for articles concerning staghorn classification and morphometry. Twenty abstracts were shortlisted from a total of 43 published abstracts. In view of the paucity of manuscripts on staghorn morphometry (4), older staghorn classifications were analyzed with the aim to determine the most optimum one having relevance to the percutaneous nephrolithotomy (PCNL) monotherapy outcome.

Results: All available staghorn classifications are limited with non-widespread applicability. The traditional partial and complete staghorn are limited due to non-descript stone volumetric data and considerable overlap of the intermediate ones in either group. A lack of standardized definition limits intergroup comparison as well. Staghorn morphometry is a recent addition to the clinical classification profiling of a staghorn calculus. It comprises extensive CT volumetric stone distribution assessment of a staghorn in a given pelvi-calyceal anatomy. It allowsmeaningful clinical classification of staghorn stones from a contemporary PCNL monotherapy perspective.

Conclusions: Morphometry-based classification affords clinically relevant nomenclature in predicting the outcome of PCNL for staghorn stones. Further research is required to reduce the complexity associated with measuring the volumetric stone distribution in a given calyceal system.

Keywords: Percutaneous nephrolithotomy; staghorn classification; staghorn morphometry; staghorn stones; stone classification.