'Microperc' micro percutaneous nephrolithotomy: evidence to practice

Purpose of review Miniaturization of instruments in percutaneous nephrolithotomy (PCNL) has spawned an interest in so-called 'microperc' in which the procedure is carried out through 16-gauge needle. Recent findings The greatest limitation of extracorporeal shock wave lithotripsy is its unpredictable results. The main limitation of retrograde intrarenal surgery is high sustainable cost and poor durability. The main limitation of PCNL is its invasiveness and associated morbidity. The interest in reducing the tract size was to potentially reduce the invasiveness of the procedure, and, therefore, attending complications. In a historical study, postrenal biopsy bleeding was found to be significant only after the tract of the needle was less than 16 gauge. Microperc extended the concept of ` All-seeing needle' to perform PCNL through a 4.85-Fr (16 gauge) tract. The working hypothesis of the ` All-seeing needle' is that if the initial tract is perfect, then the tract-related morbidity could be reduced. The optical needle helps to avoid any traversing viscera and confirms the visual cues of a correct papilla. The other advantage of microperc is that it is a novel single-step renal access procedure, resulting in a shorter insertion to lithotripsy time. This may provide a new standard of obtaining renal access. Summary Only a few published studies have documented efficacy and safety. Till further prospective and multicentric articles are published, it is still an experimental procedure requiring further research.