Introduction. The first description of ureteral appendicoplasty was provided by the Italian surgeon Giannettasio in 1901, followed by two German surgeons, Franke and Rydygier. Their work was later included in a review by Melnikoff in 1912. However, it is Melnikoff who is often erroneously credited with performing the first appendicoplasty in the literature. The first ureteral appendicoplasty operation on a 1.5-year-old child in Russia was performed by Soloviev in 1976.Objective. To report the results of performing operations on replacement of ureteral defects by ureteral appendicoplasty in children.Materials & Methods. Between 2009 and 2023, a total of 11 surgeries were conducted to replace extended ureteral defects using the appendix technique in four clinics in Russia and the Republic of Belarus. The follow-up included six boys and five girls with an average age of 79 months (ranging from 18 months to 16 years). Six operations were performed by laparoscopic access (mean operative time 356 minutes). Five operations were performed by open access (mean operative time 257 minutes).Results. Long-term results were assessed between 18 and 192 months in all patients. Urinary tract patency was evaluated based on the results of micturition cystography (in one case, vesicoureteral reflux was recorded) and intravenous urography (one case of stenosis of the distal anastomosis, which was corrected by endoscopic dissection of the stricture site using a fiberoureteroscope). In patients who underwent renoscintigraphy, no progression of renal function decline was observed. In all patients, long-term follow-up showed satisfactory urine passage.Conclusion. The results of the surgical interventions performed by us are assessed as good. In all 11 cases, the replacement of the extended ureteral stricture using an appendix allowed for the restoration of urinary flow. Furthermore, any complications that arose did not necessitate repeated reconstruction of the urinary tract. Nevertheless, it is important to note that, in our opinion, this technique cannot be considered the method of choice. Rather, it represents a last resort for patients who have undergone multiple previous operations due to severe trauma or oncological diseases. In cases involving ureteral strictures, priority should always be given to an operation involving anastomosis with sufficient ureteral length and minimal tissue tension. We firmly believe that this approach offers the best chance for a successful outcome.