Presented by: Deniz Noyan Özlü MD
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital

Introduction

We aimed to determine the effect of access sheath diameter used in percutaneous nephrolithotomy (PNL) on kidney functions. We also investigated the predictors of impaired renal function.

Materials

Data were prospectively collected from patients who underwent PNL from December 2020 to December 2021. Patients were randomized according to access sheath diameter as Group 1 (22Fr, n=44) and Group 2 (28Fr, n=44). Relative renal function (RRF) was calculated by technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy and glomerular filtration rate (GFR) was calculated by diethylenetriamine pentaacetic acid (DTPA) scintigraphy. A difference of 5% or more in RRF was considered a significant functional change. Preoperative and postoperative Kidney Injury Molecule-1 (KIM-1) levels were measured. Perioperative factors were compared between the groups.

Results

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Preoperative demographic data and stone characteristics were similar when Groups 1 and 2 were compared. There was no statistically significant difference between the groups in terms of the operation time, postoperative mean Hemoglobin (Hg) decrease, stone-free rate, presence of complications, scar development, changes in RRF, GFR and KIM-1/Creatinine (Cr) (p > 0.05). Significant deterioration in RBF was detected in a total of 6 (6.8%) patients, 3 in each group. The factors predicting loss of function were analyzed by regrouping the patients without loss of function as Group A (n=82) and those with loss as Group B (n=6). When groups A and B were compared, there was a significant difference in terms of preoperative hydroureteronephrosis grade, stone volume, Hounsfield Unit, operation time, postoperative mean Hg decrease, scar development and presence of complications (p < 0.05). Only stone volume was statistically significant in multivariate analysis (p = 0.002). The Area Under Curve (AUC) value for the stone volume was 0.907 (0.830-0.983), and the AUC value was 0.878 (0.797-0.959) when the stone volume was taken as 4750 mm³, and the sensitivity, positive predictive, specificity, and negative predictive were 100%, 23.1%, 75.6%, and 100%, respectively.

Conclusion

There was no significant effect of access sheath diameter on kidney function after PNL. Preoperative stone volume was found to be an independent predictor of loss of function after PNL.

Funding

The authors declared that this study has received no instutitional financial support.

Lead Authors

Deniz Noyan Özlü, MD
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital

Co-Authors

Mithat Ekşi, MD
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital

Selçuk Şahin, MD, Prof
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital

Alev Kural, MD, Assoc. Prof
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital

Murat Sipahi, MD
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital

Taner Kargı, MD
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital

Alper Bitkin, MD, Assoc. Prof
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital

Ali İhsan Taşçı, MD, Prof
University of Health Sciences Bakırköy Dr. Sadi Konuk Training and Research Hospital