Ureteroscopy and Percutaneous Surgery One-Shot Dilatation vs Metal Dilator During Percutaneous Nephrolithotomy in Flank-Free Supine Position: A Randomized Controlled Study Khaled Mohyelden, MD, 1,i Mohammed Abdel-Rassoul, MD, 2 Mohamed Dogha, MD, 1 Ahmed Kadry, MD, 3 and Amro Mostafa, MD 2 Abstract Background: The creation and dilatation of the nephrostomy tract is a fundamental step in percutaneous nephrolithotomy (PCNL). In one-shot dilatation (OSD), we used a single Amplatz dilator over a central Alken rod. PCNL in the supine position is as effective and safe as in the prone position. The Barts flank-free modified supine position sums several advantages of the different supine positions. We evaluated the efficacy and safety of OSD compared with metal telescopic dilator (MTD) during PCNL while the patient was in Barts flank-free modified supine position. Materials and Methods: Within 2.5 years, 150 patients with kidney stone candidates for PCNL were ran- domized into two equal groups according to the dilatation technique. In the OSD group, dilatation was per- formed using a single Amplatz dilator (30F) and in the MTD group dilatation was performed by sequential MTD (9–30F). All PCNL procedures were done with patients in Barts flank-free modified supine position. Patient characteristics, operative data, and results were collected for statistical analysis. Results: There are no statistically significant differences between both groups regarding patients’ characters. The tracts were effectively dilated in all patients. Statistical analyses show a significant difference ( p < 0.05) between both groups regarding the time of dilatation (seconds; 68 – 15 vs 147 – 18), time of X-ray exposure (seconds; during dilatation; 36 – 10 vs 61 – 15 and the total; 157 – 16 vs 181 – 20), hemoglobin loss (mg/dL; 0.7 – 0.2 vs 1.2 – 0.3), and hospital stay (days; 3 – 0.6 vs 3.7 – 0.7) with favorable results to OSD. Complication rates were comparable between the two groups. Conclusions: OSD is efficient as MTD during PCNL while patients are in Barts flank-free modified supine position, with less dilatation time, X-ray exposure, blood loss, and hospital stay than MTD. Keywords: PCNL, supine PCNL, one-shot dilatation, tract dilatation, Barts position Introduction C urrently, percutaneous nephrolithotomy (PCNL) is the treatment of choice for managing large renal stones measuring ‡2 cm. 1 Dilatation of the percutaneous tract and insertion of the access sheath is a crucial step in this operation and is per- formed using two different techniques. First, the multiple incremental dilators, either Amplatz sequential facial dila- tors or Alken metal telescopic dilator (MTD), with the hazards of a longer access time, longer duration of X-ray exposure, and increased incidence of tract displacement. MTD is reusable and thus more economical, and it main- tains a tamponed effect throughout the dilatation. Second, the balloon dilator has the advantages of shorter dilatation time and less fluoroscopy time, but it is expensive, espe- cially in developing countries. 2,3 Each technique has its own advantages and disadvantages. 3,4 Frattini published his new technique, one-shot dilatation (OSD), for tract dilatation by using a single Amplatz dilator (30F) over a central Alken rod, which combines the advantages of all previous techniques for dilatation. 5 Later, several 1 Urology Department, Faculty of Medicine, Fayoum University, Fayoum, Egypt. 2 Urology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. 3 Urology Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt. i ORCID ID (https://orcid.org/0000-0002-0351-4395). JOURNAL OF ENDOUROLOGY Volume 36, Number 6, June 2022 ª Mary Ann Liebert, Inc. Pp. 727–733 DOI: 10.1089/end.2021.0378 727 Downloaded by 23.20.13.180 from www.liebertpub.com at 06/29/23. For personal use only.