Presented by: Anna Ricapito MD
Icahn School of Medicine at Mount Sinai

Introduction

Percutaneous Nephrolithotomy (PCNL) has traditionally been done in the prone position on which a posterior calyx is designated target for puncture. Modified supine PCNL has gained increasing popularity amongst urologists. Both anterior and posterior calyces are potential targets for access in modified supine positions. However, historically urologists have been reluctant to access anterior calyces due to proximity to adjacent organs and longer access tract. To date, no study has compared the anterior to the posterior calyceal access in supine ultrasound-guided PCNL. Accordingly, the main objective of this study is to compare the safety and efficacy of anterior and posterior approaches in supine PCNL.

Materials

Consecutive patients undergoing supine PCNL with ultrasound-guided access were prospectively enrolled. Demographic information and S.T.O.N.E. scores were collected. The decision to access an anterior or posterior calyx was left to surgeon discretion. Intraoperative measurements such as access location, total access time, puncture operator, needlestick attempts, tract length, fluoroscopy time, and operative time were collected. Outcomes included stone-free rate, 30-day complications and ED visits and/or readmissions. Categorical variables were compared between groups using Chi-square of Fisher’s exact tests while continuous variables were analyzed using Mann-Whitney U-tests.

Results

,

Thus far 35 patients were enrolled. 29 underwent anterior and 6 underwent posterior access. There was a greater total stone burden in the anterior group (27 vs 15 mm, p=0.020). Age, BMI, gender, diabetes, prior PCNL rates, S.T.O.N.E. scores, preoperative hydronephrosis or stent usage did not differ between groups. Location of access was mostly lower pole (89.7% vs. 83.3%, p=.546) and started below the 12th rib (89.7% vs. 66.7%, p=.195). Fewer needlestick attempts were required in anterior approach although this difference was not statistically significant (p=.054). Other intraoperative measures did not differ. Postoperative transfusion rates were greater in the posterior than anterior group (33.3% vs. 0%, p=.025) while stone-free rate, 30-day complications, ED visits and readmissions were similar. 

Conclusion

There were some differences found in patients who underwent anterior and posterior approach in supine PCNL although the contrast in group size should be noted. Patients who underwent anterior approach had required fewer puncture attempts and had similar complications. Our preliminary data suggest that an anterior calyceal access appears to have a non-inferior safety and efficacy profile compared to a posterior approach.

Funding

None

Co-Authors

Anna Ricapito, MD
University of Foggia, Department of Urology

Alan J. Yaghoubian, MD
Icahn School of Medicine at Mount Sinai

Christopher Connors, BS
Icahn School of Medicine at Mount Sinai

Kavita Gupta, MD
Icahn School of Medicine at Mount Sinai

Samuel Yim, BS
SUNY Downstate Health Sciences University

Blair Gallante, MPH
Icahn School of Medicine at Mount Sinai

Johnathan A. Khusid, MD
Icahn School of Medicine at Mount Sinai

William M. Atallah, MD, MPH
Icahn School of Medicine at Mount Sinai

Mantu Gupta, MD, FRCS
Icahn School of Medicine at Mount Sinai