The three-dimensional reconstruction of the dilated renal pelvicalyceal system by non-enhanced computed tomography

Introduction. The three-dimensional reconstruction of the renal pelvicalyceal system (PCS) is possible when performing enhanced computed tomography (CT). However, the use of a contrast agent has its limitations associated with the presence of allergy and chronic kidney disease.Purpose of the study. To describe the method of semi-autonomous three-dimensional (3D) reconstruction of the PCS based on non-enhanced CT images of patients with upper urinary tract obstruction.Materials and methods. Five patients diagnosed with renal colic were recruited from April-May 2021. All patients underwent CT-urography after informed consent. Medical Imaging Interaction Toolkit program (MITK) expanded with explainable update were used for 3D-reconstruction of PCS via excretory and native phases. To assess the accuracy of the latter, both contrast and non-contrast models were compared regarding their surface area. Also, the PCS of one patient was used to reconstruct virtual endoscopic views based on enhanced and non-enhanced models. Five urologists estimated their similarity and potential use of non-enhanced models for the interventional planning via a Likert scale questionnaire. The resulting models were also analyzed by programmer-engineers to test their suitability for 3D-printing.Results. The average surface area of enhanced and non-enhanced models was 3291 mm2 and 2879 mm2, respectively. Obtained models were suitable for their intraluminal reconstruction and potential 3D-printing. Analyzed properties of non-enhanced models were estimated at 4.5 out of 5.0.Conclusion. The described semi-autonomous reconstruction of the renal PCS based on non-enhanced CT images allows for a short time to reconstruct its 3D-view in patients with the upper urinary tract obstruction

The non-biological simulator with the ability to regulate the position of the kidney and bone landmarks: use for training puncture access in percutaneous nephrolithotripsy

Introduction. The non-biological simulators presented in the literature are far from the real human anatomy and are primarily aimed at developing the skill of the pyelocalyceal system (PCS) puncture without the possibility of imitating various intraoperative scenarios.Purpose of the study. To describe the manufacturing and initial testing of the ultrasound-guided PCS puncture simulator with arbitrary placement of bone landmarks and a kidney model, along with the use of a retrograde view during PCS puncture.Materials and methods. This study included training for 5 resident and 2 urologists. Each participant performed the puncture 5 times using an 18-gauge ultrasound-guided needle. A comparison was made between the number of attempts to form access, the duration of the puncture and its correctness (puncture into the small calyx through the papilla), as well as the correctness of determining the target calyx. The trajectory of the needle was retrogradely assessed using a semi-rigid ureteroscope, and the anatomical identification of the selected calyx was assessed using our mobile application.Results. The total number of attempts was 49 and 14 among residents and urologists, respectively. The average duration of the puncture step was 25.2 and 12.0 seconds. In 9/25 cases, residents were able to correctly analyze visual ultrasound information to determine the target calyx. When a contrast agent was injected into the PCS after 63 punctures, no contrast leakage was found.Conclusion. The proposed PCS puncture simulator allows to develop to develop all the necessary skills for cost-effective training of young urologists in the technique of percutaneous access

Comparative analysis of the results of standard and minipercutaneous nephrolithotripsy for staghorn stones

Introduction. There are conflicting data in the literature on the results of mini-percutaneous nephrolithotripsy (PCNL) in staghorn stones.Objective. To compare the results of standard and mini-PCNL.Materials and methods. The results of PCNL in 90 patients with staghorn stones were analyzed, which were divided into two groups. In the I group, 58 (64.4%) patients underwent standard PNL with a nephroscope 24 Fr, in the II group, 32 (35.6%) patients underwent mini-PCNL with an endoscope 15 Fr. The operative time and the number of postoperative complications were compared. To assess the effectiveness of PCNL, an overview radiography or native computed tomography was performed. The operation was considered successful with residual fragments less than 3 mm.Results. Operative time, number of complications and blood transfusions, the effectiveness of PCNL in groups I and II were 80.0 ± 20.6 and 96.5 ± 25.0 min, 24.1% and 15.6%, 10.3% and 3.1%, 86.2% and 84.4%. Additional interventions were resorted to in 7 (12.1%) patients in I group, and in 4 (12.5%) patients in II group. Complications in I and II groups were observed in 14 (24.1%) and 5 (15.6%) cases. The frequency of blood transfusions was significantly higher after standard PCNL (10.3% / 3.1%, p < 0.05). Complications of grade III with mini-PCNL, replacement of an incorrectly installed stent was included in 2 patients, and with standard PCNL, ureteral stenting with urine leakage through the nephrostomic tract in 2 patients, drainage of the pleural cavity in one case.Conclusion. Standard PCNL is an effective method in staghorn stones, but the number of complications after it remains higher. In selected patients with staghorn stones, the results of mini-PCNL are comparable to those of standard PCNL

Эндоскопически ретроградно контролируемое перкутанное лечение мочевых свищей после парциальной нефрэктомии

Background. Urinary fistulas (UFs) are one of the most significant complications after partial nephrectomy. Placement of an ureteral stent eliminates urine extravasation in the majority of patients. However, some of them have persistent UFs despite upper urinary tract drainage. Such cases require retrograde injection of fibrin glue into the renal cavity through a ureteroscope or via the percutaneous approach. Some authors reported cases of simultaneous use of 2 stents and percutaneous cryoablation of the fistula, but these techniques are rare and, therefore, it is problematic to evaluate their efficacy.Objective: to evaluate the results of the new treatment method for the elimination of persistent UFs using the retrograde endoscopic percutaneous approach.Materials and methods. This study included 5 patients (3 males and 3 females) with UFs developed after kidney resection. Mean age of the patients was 55.8 years. The tumor size was 2.5 to 4.8 cm; mean R.E.N.A.L. score was 7.8. All patients had earlier undergone minimally invasive partial nephrectomy; the time between surgery and UF development varied between 3 and 10 days. Four out of 5 patients had a large amount of discharge from their paranephral drainage system, examination of which confirmed high creatinine level. Patients underwent flexible ureteropyelography in the lithotomy position. During this procedure, we identified the damaged calyx and then performed percutaneous puncture targeting the distal end of the endoscope at this calyx, ensuring that the tip of the needle appeared in the paranephral cavity in front of the injured calyx. Using the flexible ureteroscope, we inserted the needle into the pelvis, dilated the puncture opening along the string, and installed a nephrostomy drainage system (12 Fr). Then the endoscope was removed and the ureter was additionally drained with a stent. The stent was removed after 8-10 days with subsequent antegrade pyelography. If there was no extravasation, the nephrostomy tube was removed and the patient was discharged from hospital to continue treatment in outpatient settings.Results. All patients with UFs resulting from partial nephrectomy was successfully operated on. No complications were registered. The mean surgery time was 45.0 ± 20.5 min (range: 40-65 min). Only two patients had some discharge from the fistula within 1 day after nephrostomy tube removal and it stopped without any additional interventions. Three patients had their fistula healed immediately. The treatment efficacy during the whole follow-up period of 18 ± 4 months (range: 6-26 months) was 100 %.Conclusion. Ureteral stenting ensures elimination of UFs in the majority of patients after partial nephrectomy. In individuals with persistent UFs, retrograde endoscopic percutaneous drainage of the pelvicalyceal system is the method of choice, because it allows rapid and effective treatment of UFs.Введение. Мочевые свищи (МС) являются одними из значимых осложнений парциальной нефрэктомии. У большинства пациентов установка мочеточникового стента приводит к ликвидации подтекания мочи. Однако у некоторых из них, несмотря на дренирование верхних мочевых путей, наблюдаются стойкие МС, при которых ретроградно через уретероскоп или перкутанным доступом в полостную систему почки вводится фибриновый клей. Описаны случаи одновременного использования 2 стентов, перкутанная криоаблация свищевого хода. Однако эти операции выполнялись только в единичных случаях, поэтому сложно оценить их окончательную эффективность. Цель исследования - изучение результатов предложенной нами методики ликвидации стойких МС путем ретроградно эндоскопически контролируемого перкутанного лечения. Материалы и методы. В исследование были включены 5 пациентов (2 мужчин, 3 женщины) с МС, развившимися после резекции почки. Средний возраст больных составил 55,8 года. Размер опухоли колебался от 2,5 до 4,8 см, среднее число баллов по нефрометрической системе R.E.N.A.L. составляло 7,8. Всем больным ранее выполнялась малоинвазивная парциальная нефрэктомия, сроки развития МС после нее колебались в пределах 3-10 дней. У 4 из 5 больных наблюдалось большое количество отделяемого по паранефральному дренажу, результат биохимического анализа которого подтвердил высокий уровень креатинина. В литотомическом положении выполняли гибкую уретеропиелоскопию, обнаруживали поврежденную чашку. Далее перкутанно прицельно на нее и дистальный конец эндоскопа проводили пункцию таким образом, чтобы кончик иглы появлялся в паранефральной полости напротив травмированной чашки. Под контролем гибкого уретероскопа иглу проводили в лоханку, по струне пункционный ход бужировали и устанавливали нефростомический дренаж 12 Шр. Эндоскоп извлекали и дополнительно проводили дренирование мочеточника стентом. Спустя 8-10 дней стент извлекали, выполняли антеградную пиелографию. При отсутствии затека из зоны МС нефростому извлекали и больного выписывали на амбулаторное лечение.Результаты. Все больные с МС после парциальной нефрэктомии были успешно прооперированы. Осложнений не зарегистрировано. Время операции составило в среднем 45,0 ± 20,5 (40-65) мин. После удаления нефростомического дренажа только у 2 больных в течение 1 дня наблюдалось отделяемое по свищу, которое самостоятельно прекратилось. У 3 пациентов свищ зажил сразу. Эффективность лечения за период наблюдения 18 ± 4 (6-26) мес составила 100 %. Заключение. Стентирование мочеточника позволяет ликвидировать МС у большинства больных после парциальной нефрэктомии. При стойких МС методом выбора может быть ретроградно эндоскопически контролируемое перкутанное дренирование чашечно-лоханочной системы почки, что позволяет в короткие сроки и с высокой эффективностью избавить больного от МС.