INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotripsy (PCNL) is the first-line treatment for stone burden >2 cm. The aim of this study was to determine factors that would affect stone free rates after PCNL. Preoperative and intra-operative variables were correlated to the patient’s post-operative outcomes to find a link, or lack thereof, to stone-free outcomes. METHODS: A retrospective study of patients who underwent primary PCNL was done over a 1-year period. The association of the stone characteristics (based on Guy stone score), stone burden, operative time, lithotripsy time, number of access tracts, and location of access tracts to the stone-free status were analyzed. RESULTS: One hundred thirty patients who underwent PCNL were included in this study. Stone free rate was 77.69% (101/130) while 23 of the 29 patients with residual stones (22%) (29/130) required further treatment. The 30-day overall morbidity rate was 8.46% (11/130). Guy stone score (GSS) and stone burden were found to be significantly associated with stone-free status. Patients with GSS grade I had the highest stone-free rate of 95.45% while patients with GSS Grade IV had the lowest stone-free rate at 30.00%. After multivariate analysis, stone burden (OR 1.176; 95% CI 1.084- 1.275; p 0.00) and GSS 4 (OR 15.374; 95% CI 1.164- 202.980; p 0.04) were significant independent risk factors for stone-free status. CONCLUSION Stone clearance and complication rate after PCNL of the present study were 78% and 8.5%, respectively, comparable with published data. A higher Guy’s stone score and a higher stone burden were significantly associated with retained stones post-PCNL.

Background. Despite being a clean-contaminated procedure, performed only in patients with sterile urine preoperatively, percutaneous nephrolithotripsy (PCNL) is associated with significant infectious perioperative complications. A local antibiogram is of paramount importance in optimizing antibiotic prophylaxis in PCNL because of the substantial variation in bacterial distribution and antibiotic sensitivity worldwide.

Objectives. The incidence of post-PCNL infectious complications, microorganism distribution, and antibiotic sensitivities from patients admitted for PCNL was determined. The risk factors associated with positive cultures and the development of fever and bacteremia were also analyzed.

Methods. A retrospective study of 102 patients who underwent PCNL under a surveillance protocol was done. The susceptibility of isolates from different specimens was evaluated against the most common antibiotics in the hospital. Chi-square and Student's t-test were used to determine differences in the frequencies and means for other risk factors for those who developed fever and urosepsis and those who did not.

Results. The incidence of fever and urosepsis was 25% and 4%, respectively. The most common organism on urine specimens was Escherichia coli which showed high sensitivity to aminoglycosides. The most common isolate on stones was Pseudomonas aeruginosa, which showed higher sensitivities to the fluoroquinolones. The isolates showed nearly consistent resistance to ceftriaxone. No significant association was found between the clinical variables studied and the occurrence of infectious complications.

Conclusion. There are comparable rates of infectious complications to published literature. A change in antibiotic prophylaxis was warranted, given the high resistance to ceftriaxone and the predominance of Pseudomonas aeruginosa on stone isolates. Further surveillance is required to identify significant risk factors for the development of post-PCNL infectious complications.

Nephrolithotomy, Percutaneous ; Bacteriology ; Microbial Sensitivity Tests ; Nephrolithiasis