Abstract
Dear Editor,
We recently read the publication “Perioperative Outcomes of Same-Session Bilateral versus Unilateral Ureteroscopy for Stone Removal: Results from the GRAND Study” by Pyrgidis et al. with interest. 1 We commend the authors for their meticulous work but would like to express several concerns regarding the interpretation of their findings. The authors’ conclusion about higher complication risks with bilateral same-session ureteroscopy(BSSU) warrants further examination.
The baseline characteristics of patients undergoing BSSU were notably worse than those undergoing unilateral ureteroscopy (UU). Although the authors mention they adjusted for these characteristics, the regression models used did not adjust for hypertension, chronic heart failure, chronic cerebrovascular disease (CCD), and chronic obstructive pulmonary disease. The baseline incidence of chronic heart failure and CCD was more than double in the BSSU group. The increased risk of perioperative myocardial infarction, intensive care unit admission, and mortality, with odds ratio (OR) of 2, 1.9, and 3.1, would likely stem from these confounding variables for which the statistical model did not adjust.
The study also found the risk of sepsis to be double in the BSSU compared to the UU group (OR-2.4). However, granular data on preoperative stone burden, urine culture, operative time, and stone composition was not available in the GRAND database. These factors are well-established risk factors for sepsis after ureteroscopy. 2,3 The authors cited a meta-analysis reporting a 6% incidence of combined urosepsis, UTI, mucosal laceration, stone migration, and ureteral perforation to support their results. 4 It is important for readers to know that only 1 out of 431 patients from 11 studies (0.23%) in the referenced meta-analysis had urosepsis, a much more serious complication compared to the others it has been grouped with.
The authors concluded that BSSU also doubles the risk of acute kidney injury after adjusting for baseline chronic kidney disease status. Multiple previous studies have proved that increases in serum creatinine levels are transient and lack any long-term impact on renal function. 3 The study fails to explain the increased risk of blood transfusion after BSSU (OR: 4.2). Although bleeding is a known complication of ureteroscopy, most cases are self-limited, and the risk of blood transfusion associated with ureteroscopy in a real-world database of 11,885 patients was less than 0.2%. 5,6 Data on the use of anticoagulants, the presence of baseline anemia, and the development of postoperative hematomas, which are possible risk factors for blood transfusion, are not available in the GRAND database.
Interestingly, 54% of patients in the present study were pre-stented. In our opinion, this is an extremely high number. Society guidelines recommend stent placement only in patients with sepsis or persistent pain not responding to conservative management. Pre-stenting adds a financial burden to the health care system. Additionally, all ureteroscopy procedures in the present study were done on an inpatient basis with a mean hospital stay of 3.9 ± 4.2 days. The overwhelming majority of ureteroscopies in the United States are done on an ambulatory basis, with only 2.2% of patients needing inpatient hospitalization. 7 Intuitively, patients with bilateral urolithiasis would require hospitalization twice for a staged procedure, thereby doubling the total length of hospital stay and increasing hospitalization costs and complications.
With all this in mind, we believe that BSSU is promising in terms of patient care and health care expenditure. Previous studies have confirmed the safety and efficacy of BSSU. 4,5 In our opinion, the increased complication rate of BSSU noted by the authors more likely suggests correlation than causation. Hence, we firmly believe that urologists should not hesitate to offer BSSU to appropriate patients based on the flawed risk assessment of the present study.