Complications associated with percutaneous nephrolithotomy

The increasing global prevalence of nephrolithiasis continues to burden the healthcare delivery systems of industrialized nations and exact a disproportionate humanitarian toll on populations of the developing world (1). In the United States alone, the prevalence of nephrolithiasis is nearly twice the rate reported in the 1960s (2-5). The subsequent rise in surgical interventions for nephrolithiasis has resulted in the development of new minimally invasive technologies and techniques, but it has also led to the resurgence of established methods such as percutaneous nephrolithotomy (PNL). Percutaneous entry into the renal collecting system was first described in the 1950s, but it wasn't until the mid 1970s and 1980s that percutaneous access to the renal collecting system was routinely utilized for the removal of nephrolithiasis (6-8). Although PNL initially proved to be an effective technique, the near-concurrent introduction of shockwave lithotripsy (SWL) resulted in a rapid and marked decrease in the utilization of PNL (9). There has been, however, a recent increase in the utilization of PNL, largely attributed to the limitations of newer SWL equipment, an increase in stone prevalence, and the refinement of PNL indications, techniques and instrumentation (10-14). PNL is considered the standard treatment for staghorn and large-volume renal calculi, as well as upper tract calculi refractory to other modalities, difficult lower pole stones, cystine nephrolithiasis, and calculi in anatomically abnormal kidneys. PNL is typically a very safe and well-tolerated procedure, but as with any surgical intervention, PNL is associated with a specific set of complications (15,16). Complication rates for PNL reportedly range from 20-83% (16-21). The true complication rates of PNL are difficult to determine and compare because most contemporary reviews of PNL outcomes report only rates of specific complications of the procedure. Other authors have attempted to standardize the reporting of complications of PNL by utilizing the modified Clavien complication grading system, or by assigning Clavien grading system scores to the complications most commonly associated with PNL (22,23). An international multi-center study of 5,803 patients undergoing PNL reported an overall complication rate of 21.5%. The study, conducted by the Clinical Research of the Endourological Society (CROES), utilized the modified Clavien system for reporting complications. The majority of complications were minor, with rates of 11.1%, 5.3%, 3.6%, 0.5% and 0.03% of for grade I, II, III, IV and V complications, respectively (21). The most common minor complications included nephrostomy tube leakage (15%) and transient fever (10-30%) (21,22,24). Major complications …