We analyzed 131 patients who underwent RIRS for LRP stones < 2 cm between 01.06.2021 and 31.01.2022 in our clinic prospectively. The patients were prospectively randomized (using simple randomization by computer) to two groups. One group received RIRS procedure only (non-PDI group) and the other group received PDI therapy after the RIRS procedure (PDI group). Patients with LRP stones < 2 cm and approving the treatment method were included in the study. Patients with a history of cerebrovascular disease, uncontrolled hypertension, bleeding diathesis disorder, anticoagulation therapy, distal ureteral stenosis, pregnancy, severe skeletal malformation, severe obesity, urinary tract infection were excluded from the study. Finaly, 114 patients were included in this study (Fig. 1).
Our study was prepared in accordance with the Principles of Helsinki, it was reviewed and approved by the 2nd Clinical Research Ethics Commitee of Ankara City Hospital on 10.03.2021 (Ethics committee approval number: E2-21-158).
Age, sex, body mass index (BMI), preoperative double-J (DJ) stent presence, ESWL history presence were obtained from the anamnesis of the patients and recorded. The operation durations were also recorded.
Stone size, density, number (single or multiple), side (left-right) were evaluated according to preoperative computed tomography. Stone size was measured as the longest diameter of the stone. For the multiple stone number patients, stone size was calculated as the sum of all stones longest diameter.
IPA was measured as the internal angle formed at the intersection of the ureteropelvic axis and the central axis of the lower pole infundibulum. IL was measured as the distance from the furthest point below the calyx containing the stone to the midpoint of the lower border of the renal pelvis.
Patients with positive urine cultures were treated with appropriate antibiotics for at least 7 days. Preoperative urine cultures of all patients were sterile. All patients were given prophylaxis with intravenous 2 g cefazolin within 1 hour before surgery. RIRS was performed in all patients in the lithotomy position under general anesthesia.
Before RIRS, ureterorenoscopy was performed with a 9.5 F rigid renoscope (Karl Storz, Tuttingen, Germany) for dilatation. A 9.5–11 F ureteral access sheath (Flexor® Ureteral Access Sheath, Cook Medical, USA) was placed in the ureter to reduce intrarenal pressure and provide optimal viewing. After the access sheath reached the collector system, the collector system was reached by entering through the access channel with a 7.5 F flexible ureterorenoscope (Karl Storz, Flex X2, GmbH, Tuttlingen, Germany). The stone was fragmented using a holmium-yttrium-aluminum-garnet (Ho:YAG) laser (200µm) sent from the working channel of the flexible ureterorenoscope. At the end of the operation, DJ catheter and urethral catheter were applied to all cases.
PDI therapy was performed as follows: In the postoperative period, oral hydration was applied to the patients by allowing them to drink 500 ml of water within 30 minutes after oral intake permission. 30 minutes later, the patient was fixed to the bed for inversion, the patient bed was adjusted to 30° Trendelenburg position (Fig. 2). Then, percussion was performed in prone position for 5 minutes, in the position that the operated side was elevated to 45° with the pillow for 5 minutes, in full flank position for 5 minutes and in the supine position for 5 minutes, by hitting the flank area with the palm of the hand for a total of 20 minutes. Subsequently, the bed was placed in the neutral position while the patient was in the supine position and rested for 10 minutes. The process was terminated after 30 minutes.
Patients were evaluated with non-contrast abdominopelvic computed tomography (CT) at 1 month postoperatively. Absence of stones in the urinary tract was accepted as success.
Statistical Analysis
Data coding and statistical analyzes were performed on the computer using the SPSS 22 software package program (IBM SPSS Statistics, IBM Corporation, Chicago, IL). The conformity of the variables to the normal distribution was examined using the Shapiro-Wilk tests. Mann-Whitney U test was used to compare non-categorical parameters between groups. Chi-square or Fisher's exact tests were used for categorical variables. Risk factors for RIRS success in lower pole stones were determined by univariate logistic regression analysis. Whether the possible factors identified in this analysis were independent risk factors were evaluated using the Bacward LR method with multivariate analysis. Cases with a p value below 0.05 were considered statistically significant.