Definition of clinically insignificant residual fragments after percutaneous nephrolithotomy among urologists: a world-wide survey by EAU-YAU Endourology and Urolithiasis Working Group

Abstract

INTRODUCTION The aim of this article was to evaluate the current perception of urologists as to what size is considered as a clinically insignificant residual fragment (CIRF). MATERIAL AND METHODS A survey was globally distributed to the members of the Endourological Society via SurveyMonkey. RESULTS A total of 385 participants responded to the survey on CIRF. Most participants considered 2 mm (29%) as CIRF threshold, followed by 3 mm (24%), 4 mm (22%), 0 mm (14%), 5 mm (8%) and 1 mm (3%). North American urologists considered CIRF to be smaller than urologists from Asia, Eurasia and South America, (p-values ≤0.001, 0.037 and 0.015 respectively). European urologists identified smaller CIRF in comparison to Asian urologists (p-value = 0.001). Urologists mainly using a pneumatic lithotripter accepted larger fragments as CIRF, compared to urologists mainly using ultrasonic devices or a combination of ultrasonic and pneumatic devices (p-value = 0.026 and 0.005 respectively). Similarly, urologists mainly performing X-Ray and ultrasound as post-operative imaging accepted larger fragments as CIRF in comparison to urologists mainly performing non-contrast computed tomography (p-value = 0.001). CONCLUSIONS What is considered as CIRF varies between urologist from different continents and seems to be associated with the lithotripter used and the post-operative imaging modality of preference to assess treatment success.

Prospective Comparative Analysis of Supine Versus Prone Percutaneous Nephrolithotomy in Patients with Complex Renal Stone Disease and Difficult Anatomy

“…Asymptomatic, non-infectious, and non-obstructive stone fragments (≤4 mm) seen on computed tomography (CT) scan that persist in the urinary system following the final session of any intervention (Extracorporeal shockwave lithotripsy [ESWL], Ureteroscopy [URS], or PCNL) for urinary stones are referred to as clinically insignificant residual fragments. 10 , 11 …”

Physical Techniques to Remove Residual Stone Fragments in the Urinary System

“…Residual fragments (RF) are the most important risk factor for stone recurrence or new stone growth [1]. Traditionally, RF less than 4 mm in diameter are defined as a clinically insignificant RF that can be excreted spontaneously, while RF greater than 4 mm are defined as significant residual fragments that require aggressive treatment [2]. RF are associated with the risk of renal colic, urinary tract infection, stone regeneration, and other complications that can severely affect patient health.…”