AUA 2024: A Multi-Center Randomized Controlled Trial Of Ambulatory Versus Inpatient Percutaneous Nephrolithotomy

( Dr. Gregory Hosier of the University of Manitoba, in conjunction with the University of California, San Francisco, reported on their newest findings relating to the similarities of ambulatory versus inpatient PCNL. Citing previous literature, which included over 500 patients, Dr. Hosier discussed the perceived benefits of ambulatory surgery which included faster patient recovery, less pain associated with nephrostomy tube placement, and patient savings on the cost of care. Considering these benefits, Dr. Hosier identified the extensive exclusion criteria that preclude a vast number of patients from entering such studies. Therefore, this study sought to compare a more representative patient population to better analyze ambulatory versus inpatient PCNL.

Exclusion criteria was much more modest as only patients younger than 18 years old and patients requiring post-op admission were excluded. Patients undergoing both mini and regular sized PCNLS with either ultrasound or fluoroscopically guided access and stented at the end of surgery were included. Overall, 70 patients between the University of Manitoba and UCSF took part in the study. To be considered for ambulatory discharge Dr. Hosier specified that patients could not have endured a significant pelvicalyceal injury or intraoperative bleeding, as well as showing hemodynamic stability. Patients included did not need immediate transfusion nor show fever or pneumothorax.


After displaying the above table, Dr. Hosier confirmed that there were no differences in age, BMI, or ASA score as a result of the study's randomization and stratification. Furthermore, there were no differences in stone complexity between the two groups. In the ambulatory group, the time-to-discharged averaged around 3-4 hours compared to 1 day for inpatient discharge. There were no differences in stone-free rates as approximately 70% of each group was considered stone-free based on CT imaging. No significant difference in complication rates was shown by either group with ambulatory having a complication rate of 6% and inpatient group with a complication rate of 14%. Furthermore, one-month readmission rates for ambulatory and inpatient groups were 6% and 3% respectively, again displaying no significant difference. 

In a comparison of all the variables analyzed, ambulatory PCNL proved almost identical in outcomes compared to inpatient PCNL. Complication, stone-free, readmission rates, and quality of life measures were non-inferior between ambulatory and inpatient PCNL. In summation of all the data presented, Dr. Hosier urged urologists to consider sending patients, who underwent a smooth surgery and immediate postoperative-course, home the same day of the surgery.

At the conclusion of the presentation moderators and members of the audience asked questions concerning the presentation. One moderator asked if patients were assigned to groups after surgery. Dr. Hosier explained that they were assigned “at the preop visit…a lot of surgical studies they get randomized after surgery is done, everything went well. We really wanted to capture, for bed planning purposes, how many going into it you think and how many and how many actually could go home the same day”. This gave the study an extra edge over previous studies as it was a true randomization that did not consider the outcome of the surgery prior to making the decision to include them in the ambulatory or inpatient groups. This was promptly followed by a question from the audience asking if the surgeons themselves were blinded during the study. Dr. Hosier conceded, “no so they knew before so did the patients, just for bed purposes”. Dr. Ralph Clayman, of UCI Urology, asked two questions from the audience. The first was regarding the position of the patient during surgery, to which Dr. Hosier responded, “60 to 70 were supine and the remainder were prone”. Dr. Clayman’s second question inquired of the management of foley catheters for patients who underwent PCNLs. For females, Dr. Hosier responded, “I often take the catheters out right at the end of the case”. In the case of an older gentleman who may suffer from enlarged prostates, he would “leave the catheter in for them to undergo a trial of void in recovery”.

Presented by: Gregory Hosier, MD, MSC, FRCSC, Assistant Professor University of Manitoba, Manitoba, Canada

Written by: Mark Sarwat Hana, Assistant Research Specialist, Department of Urology, University of California Irvine, during the 2024 American Urological Association (AUA) Annual Meeting, San Antonio, TX, Fri, May 3 – Mon, May 6, 2024.