The role of middle calyx puncture in percutaneous nephrolithotomy: relative factors and choice considerations.

Percutaneous nephrolithotomy (PCNL) is a well established procedure for management of renal calculi. It is generally believed that the access to the renal pelvic system via the desired calyx is the most crucial step during the whole procedure. The adequacy of the access directly influences the success and complication rates of PCNL. Traditionally, a lower pole access was routinely performed for less complication. Upper calices are also preferred for access in a given condition with large and complex calculi. However, the middle calices access is seldom selected. In aim to provide the reader some advantages of middle pole approach and a broaden horizon in determining the strategy of renal puncture, the present review describes the anatomical basis of the percutaneous tract. It provides a literature review of the success rate and efficiency of middle calyx access alone with the advantage of this approach, especially in dealing with large and complex stones.