WCE 2019: Predisposing Factors Affecting Blood Loss During Percutaneous Nephrolithotomy

Abu Dhabi, United Arab Emirates (UroToday.com) Advancements in medical technology have made percutaneous nephrolithotomy (PCNL) the standard of care for large or complex stones, according to Dr. Anna Zampini of Icahn School of Medicine at Mount Sinai. Although PCNL has been proven to be an effective means of treating larger stone burdens, the potential for serious complications, such as severe bleeding and infection, still remains a notable risk. In her study, Dr. Zampini and her colleagues sought to evaluate and compare clinical and surgical characteristics of patients who had increased blood loss during PCNL to those who did not. 

In the study, Dr. Zampini and her team queried a database of patients who underwent PCNL at a comprehensive stone center between 2015 and 2019. It was their aim to identify those patients who had increased blood loss during surgical intervention. They identified patients with increased blood loss by examining preoperative and postoperative decreases in Hct equal to or greater than one standard deviation above the mean Hct drop (5.0 points). Then, these patients were split into two groups: patients who experienced increased blood loss (Hct decrease greater than 5) and patients who did not experience an increased blood loss (Hct decrease less than 5). 

What Dr. Zampini found was that, out of the 235 patients she identified, 59 (25%) had experienced increased blood loss. This subsect of patients in her cohort closely corresponded to those patients who came in with greater numbers of stones. More specifically, the proportion of patients with interpolar, upper polar, or staghorn calculi was found to be significantly higher within the increased blood loss group. Furthermore, the number of access tracts that were made during PCNL was also associated with increased blood loss. 

Dr. Zampini concluded that patients with a history of HLD, multiple stones, staghorn stones, upper pole and interpolar calculi, and increased mean number of accesses were more likely to have increased blood loss during PCNL. Since upper and lower pole access sites are preferred among surgeons during PCNL, trying to access interpolar stones may create excessive torque that may contribute to further infundibular tearing and subsequent bleeding. Based on these findings, Dr. Zampini recommends more liberal use of nephroscopy and/or retrograde ureteroscopy during PCNL to access upper pole, interpolar, and staghorn stones as these means might further contribute to renal damage and greater blood loss. 

Presented by Anna Zampini, Fellow, Icahn School of Medicine at Mount Sinai, New York, USA

Written by Andrew Shea Afyouni, BS, Junior Research Specialist and Medical Student, University of California, Irvine Department of Urology at the 37th World Congress of Endourology (WCE) – October 29th-November 2nd, Abu Dhabi, United Arab Emirates