Presentation Authors: Jacob Bamberger*, Blair Gallante, Ryan Chandhoke, William Atallah, Mantu Gupta, New York, NY
Introduction: Before choosing a method of surgical intervention it is imperative to weigh both the benefits, as well as the risks. Within the past few decades, PCNL has proven very effective, and become the preferred method of exaction for large renal stones. However, as with any invasive procedure, PCNL carry more risks associated than other nephrolithiasis interventions, specifically the elevated chance of blood loss and infection. The objective of this study is to evaluate and compare clinical and surgical characteristics of patients who had significant blood loss during a PCNL vs. those who did not.
Methods: A database of patients undergoing PCNL at a comprehensive stone center was analyzed to identify those who experienced significant blood loss. Significant blood loss was operationalized by a pre- vs. post-operative hematocrit (Hct) level decrease greater than 5%. Clinical and intra-operative data including, demographics, relevant labs, number of punctures, stone location, and stone characteristics were collected and reviewed. ANOVA, chi square, and regression were then conducted to elucidate differences between the two patient groups.
Results: 193 patients within our database presented for PCNL between 1/2017 and 10/2018, 63 of which had completed pre- and post-operative labs. 25 of 63 (39.7%) were classified as experiencing significant blood loss. Univariate analysis revealed a significant difference in proportion of patients with interpolar stones (p=0.025), mean surgery time (p=0.006), and mean number of access tracts (p=0.006) between the two blood loss groups. Aspirin use was not found to be significantly different between the two groups, while staghorn stones - partial and complete - trended toward significance (p=0.069). Within our regression model, the presence of interpolar calculi were found to be the only independent predictor of blood loss (p=0.024). Table 1.
Conclusions: During PCNL, patients with interpolar calculi are more likely to experience significant blood loss. Since surgeons use the upper and lower poles as primary access sites during PCNL, trying to access interpolar stones may create excessive torque that leads to infundibular tearing and bleeding. More liberal use of nephroscopy and/or retrograde ureteroscopy during PCNL to access these stones may decrease the risk of blood loss.