Surgical Technique of Supine Percutaneous Nephrolithotomy in Children / Técnica quirúrgica de la nefrolitotomía percutánea en supino en niños

Percutaneous nephrolithotomy (PCNL) in children has becomemore widely used due to its high efficacy and safety and to the development of miniaturized instruments. A supine approach is promising due to advantages such as better ventilation, reproducibility, and ergonomics. The purpose of the present study is to describe our surgical technique with special considerations in the pediatric population. We used an oblique supine position supported by one silicone gel positioning pad under the hip and another under the ipsilateral flank. The anatomical landmarks used to guide the puncture were the 11th and 12th ribs, the posterior axillary line, and the iliac crest. Initially, a ureteral catheter was introduced endoscopically. A retrograde pyelography was performed to guide the puncture, which was performed using a biplanar technique. A hydrophilic guide wire was then advanced through the needle. Dilation was performed with Alken telescopic dilators until 14 Ch. Fragmentation was performed either with a 13 Ch semirigid cystoscope or a flexible ureteroscope using a holmium: yttrium aluminum garnet (Ho:Yag) laser.We left a double J catheter. Supine PCNL in the pediatric population has comparable efficacy in terms of stone free rate to that of the prone approach as well as less complications. Certain considerations in children are careful padding and placement of the patient close to the edge of the table. Puncture should be guided by ultrasound to reduce radiation exposure. Miniaturized equipment is not widely available, so adaptation of adult equipment for the pediatric population is sometimes necessary.

La nefrolitotomía percutánea en niños se ha vuelto ampliamente utilizada por su alta efectividad, seguridad, y por la miniaturización de los instrumentos endoscópicos. El abordaje en supino es prometedor por sus ventajas, como mejor ventilación, reproducibilidad, y ergonomía. El propósito es describir nuestra técnica quirúrgica con las consideraciones especiales a tener en cuenta en la población pediátrica. Todos nuestros pacientes han sido intervenidos bajo la siguiente técnica quirúrgica: en una posición oblicua en supino, utilizando soportes de silicona ubicados debajo de la cadera y del flanco ipsilateral, se marcan los reparos anatómicos: las costillas once y doce, la línea axilar posterior y la cresta ilíaca. Inicialmente se introduce un cateter ureteral por vía endoscópica, con el cual se realiza una pielografía retrógrada para guiar la punción con una técnica biplanar. Se avanza una guía hidrofílica y, sobre esta, los dilatadores telescopados de Alken hasta un tracto de 14 Ch. Se realiza la fragmentación con un cistoscopio semirígido de 13 Ch o con un ureteroscopio flexible utilizando el láser Ho:Yag. Se deja un cateter JJ. La nefrolitotomía percutánea en la población pediátrica es comparable en términos de tasa libre de cálculos al abordaje en prono, con menos complicaciones. Una consideración importante en niños es una adecuada posición, cerca al eje de la mesa. La punción debe ser guiada por ultrasonido para disminuir la exposición a radiación. La disponibilidad de equipos miniaturizados es limitada, por lo cual usualmente es necesario adaptar los equipos de adultos.

High pressure endoscopic irrigation: impact on renal histology

ABSTRACT Purpose: High intra-renal pressures during flexible ureteroscopy have been associated with adverse renal tissue changes as well as pyelovenous backflow. Our objective was to investigate the effect of various intra-renal pressures on histologic changes and fluid extravasation during simulated ureteroscopy. Materials and Methods: Twenty-four juvenile pig kidneys with intact ureters were cannulated with an Olympus flexible ureteroscope with and without a ureteral access sheath and subjected to India ink-infused saline irrigation for 30 minutes at constant pressures ranging from sphygmomanometer settings of 50mm, 100mm and 200mmHg. Renal tissue samples were collected, processed and stained, and were evaluated by a blinded pathologist for depth of ink penetration into renal parenchyma as a percentage of total parenchymal thickness from urothelium to renal capsule. Results: The mean percentage of tissue penetration for kidneys with ink present in the cortical tubules at sphygmomanometer pressure settings of 50, 100, and 200mm Hg without a ureteral access sheath was 33.1, 31.0 and 99.3%, respectively and with ureteral access sheath was 0, 0 and 18.8%, respectively. Overall, kidneys with an access sheath demonstrated a smaller mean tissue penetration among all pressure compared to kidneys without a sheath (6.3% vs. 54.5%, p=0.0354). Of kidneys with sheath placement, 11% demonstrated any ink compared to 56% of kidneys without sheath placement. Conclusions: Pressurized endoscopic irrigation leads to significant extravasation of fluid into the renal parenchyma. Higher intra-renal pressures were associated with increased penetration of irrigant during ureteroscopy in an ex-vivo porcine model.

Novel semirigid ureterorenoscope with irrigation and vacuum suction system: introduction and initial experience for management of upper urinary calculi

ABSTRACT Objective: This study aims to design a novel semirigid ureterorenoscope with irrigation and vacuum suction system and a modified ureteral access sheath (UAS) named Sotn ureterorenoscope® (Sotn=ShuoTong Medical Company) to overcome the deficiencies of the current procedure and to improve the efficiency and safety of using Sotn ureterorenoscope® for treatment of upper urinary calculi. Materials and Methods: Fifty-eight patients, comprising 31 males and 27 females, were evaluated. The medical records of 58 patients with upper urinary calculi treated with Sotn ureterorenoscope® from March 2015 to June 2017 were retrospectively reviewed at the Second Affiliate Hospital of Guangzhou University of Chinese Medicine in China. The primary outcome was stone-free rate (SFR) assessed by computed tomography on the 1st day and one month after treatment. The secondary outcome was postoperative complication rate. Results: The mean and SD of operative duration was 48.5 (10.4) min, and the mean and SD of stone size was 15.6 (5.6) mm. The primary overall SFR was 89.7% (52/58) and 100% at 1 month follow-up. Complication, which was Clavien I (minor fever managed by antipyretic therapy), was detected in 1.7% (1/58) of the patients. Conclusions: Sotn ureterorenoscope® is technically feasible, efficacious and safe for treatment of upper urinary calculi because of its advantages of high SFR and low complication rates.

Design and Validation of a Non-biological 3D Printed Pelvocalyceal System (RIRS Box) for Simulation-based Training of Flexible Ureteroscopy: A Stage 2A Surgical Innovation Study

@#In the field of Urology, flexible ureterorenoscopy (fURS) remains a challenging skill for junior residents to develop due to its steep learning curve. Hence, training models were incorporated into simulation-based training to allow for novice trainees to overcome the learning curve without potentially compromising patient outcomes and minimize complications. OBJECTIVE: To describe the design and test the validity of a non-biological three-dimensional (3D) model of the pelvocalyceal system as a tool for simulation-based training for flexible ureterorenoscopy METHODS: This was a prospective, quasi-experimental, surgical innovation research stage 2a study conducted in a tertiary government hospital. The retrograde intrarenal surgery (RIRS) box was composed of four siliconized pelvocalyceal systems which were 3D printed using computed tomography urograms of actual patients. Thirty-two urologists were asked to perform flexible ureteroscopy using the RIRS box and were given a questionnaire to assess face and content validity using the Likert scale. RESULTS: The RIRS Box training model showed good face and content validity. The 3D printed pelvocalyceal system was judged to have a close anatomical resemblance to an actual calyceal system. While performing fURS, the RIRS box provided similar pelvocalyceal visualization and instrument handling as in an actual procedure. Majority of participants considered the training model useful for training (75%) and believed that it may improve the RIRS technique (46.8%). CONCLUSION: The RIRS Box training model may help urologists improve the manner in which they acquire technical knowledge and skills necessary in performing fURS.

Design and validation of a non-biological 3D printed pelvocalyceal system (RIRS BOX) for simulation-based training of flexible ureteroscopy: A stage 2A surgical innovation study

@#In the field of Urology, flexible ureterorenoscopy (fURS) remains a challenging skill for junior residents to develop due to its steep learning curve. Hence, training models were incorporated into simulation-based training to allow for novice trainees to overcome the learning curve without potentially compromising patient outcomes and minimize complications.@*OBJECTIVE@#To describe the design and test the validity of a non-biological three-dimensional (3D) model of the pelvocalyceal system as a tool for simulation-based training for flexible ureterorenoscopy.@*METHODS@#This was a prospective, quasi-experimental, surgical innovation research stage 2a study conducted in a tertiary government hospital. The retrograde intrarenal surgery (RIRS) box was composed of four siliconized pelvocalyceal systems which were 3D printed using computed tomography urograms of actual patients. Thirty-two urologists were asked to perform flexible ureteroscopy using the RIRS box and were given a questionnaire to assess face and content validity using the Likert scale.@*RESULTS@#The RIRS Box training model showed good face and content validity. The 3D printed pelvocalyceal system was judged to have a close anatomical resemblance to an actual calyceal system. While performing fURS, the RIRS box provided similar pelvocalyceal visualization and instrument handling as in an actual procedure. Majority of participants considered the training model useful for training (75%) and believed that it may improve the RIRS technique (46.8%).@*CONCLUSION@#The RIRS Box training model may help urologists improve the manner in which they acquire technical knowledge and skills necessary in performing fURS.

A comprehensive literature-based equation to compare cost-effectiveness of a flexible ureteroscopy program with single-use versus reusable devices

ABSTRACT Purpose to critically review all literature concerning the cost-effectiveness of flexible ureteroscopy comparing single-use with reusable scopes. Materials and Methods A systematic online literature review was performed in PubMed, Embase and Google Scholar databases. All factors potentially affecting surgical costs or clinical outcomes were considered. Prospective assessments, case control and case series studies were included. Results 741 studies were found. Of those, 18 were duplicated and 77 were not related to urology procedures. Of the remaining 646 studies, 59 were considered of relevance and selected for further analysis. Stone free and complication rates were similar between single-use and reusable scopes. Operative time was in average 20% shorter with digital scopes, single-use or not. Reusable digital scopes seem to last longer than optic ones, though scope longevity is very variable worldwide. New scopes usually last four times more than refurbished ones and single-use ureterorenoscopes have good resilience throughout long cases. Longer scope longevity is achieved with Cidex and if a dedicated nurse takes care of the sterilization process. The main surgical factors that negatively impact device longevity are lower pole pathologies, large stone burden and non-use of a ureteral access sheath. We have built a comprehensive financial cost-effective decision model to flexible ureteroscope acquisition. Conclusions The cost-effectiveness of a flexible ureteroscopy program is dependent of several aspects. We have developed a equation to allow a literature-based and adaptable decision model to every interested stakeholder. Disposable devices are already a reality and will progressively become the standard as manufacturing price falls.

Application of Intermittent Lung Inflation Combined with Rigid Ureteroscopy in Treating Upper Ureteral Stones That Were Not Fully Visible / 中国医学科学院学报

To analyze the effectiveness and safety of intermittent lung inflation combined with rigid ureteroscopy in the treatment of upper ureteral stones that were not fully visible. The clinical and imaging data of 56 patients with upper ureteral stone undergoing rigid ureteroscopic lithotripsy combined with intermittent lung inflation in Zhejiang Quhua Hospital from March 2016 to October 2017 were retrospectively analyzed.Intermittentt lung inflation was used to change and stabilize the position of ureteral calculi during the operation,so as to ensure the visual field of ureteroscopy.Holmium laser lithotripsy was performed to remove the stones.Urinary tract abdominal plain X-ray or CT urography was performed 1 and 3 months after the operation to evaluate the residual stones and the clinical efficacy. Stones were successfully removed after a single attempt in 48 patients.In 5 patients,stones escaped into the kidney during ureteroscopic lithotripsy,and thus flexible ureteroscopy were performed.In 3 patients,a second session of auxiliary procedure was required,among whom 2 patients received extracorporeal shock wave lithotripsy and 1 patient underwent extracorporeal shock wave lithotripsy+ureteroscopic lithotripsy.The stone-free rates 1 and 3 months after surgery were 94.6%(53/56)and 100%(56/56),respectively.No severe complication such as ureter perforation,gross hematuria,septic shock,or pneumothorax occurred during and after surgery. Intermittent lung inflation in tracheal intubation under general anesthesia in patients with proximal ureteral stones that can not be fully visible during rigid ureteroscopic lithotripsy was feasible and reliable.It can effectively change the location of stones and thus enable safe and effective lithotripy.It expands the indications of rigid ureteroscopy for treating upper ureteral stones.

Ureteral access sheaths: a comprehensive comparison of physical and mechanical properties

ABSTRACT Introduction: Ureteral access sheaths (UAS) facilitate flexible ureteroscopy in the treat- ment of urolithiasis. The physical properties of UAS vary by manufacturer and model. We compared three new UAS: Glideway (GW, Terumo, 11/13Fr, 12/14Fr), Pathway (PW, Terumo 12/14F) and Navigator HD (NHD, Boston Scientific, 11/13Fr, 12/14Fr) in the domains of safety characteristics, positioning characteristics, lubricity and radio- opacity. Materials and Methods: In vitro testing of the three UAS included safety testing-tip perforation force, sheath edge deformation and dilator extraction forces. Positioning characteristics tested included tip bending, stiffness (resistance to coaxial buckling forces), kinking (resistance to perpendicular forces), and insertion forces. Lubricity was assessed by measured frictional forces of the outer sheath. Finally, radio-opacity was tested utilizing fluoroscopic imaging of the three 12F sheaths and inner dilators. Results: The PW (0.245 lb) and GW (0.286 lb) required less force for tip perforation compared to the NHD (0.628 lb). The NHD sheath edge deformation was mild compared to more severe deformation for the PW and GW. The PW (1.008 lb) required greater force than the GW (0.136 lb) and NHD (0.043 lb) for inner dilator removal. The GW (3.69 lbs) and NHD (4.17 lb) had similar inner dilator tip stiffness when bent, while the PW had the weakest inner dilator tip, 1.91 lbs. The PW (0.271 lb) was most susceptible to buckling and kinking (1.626 lb). The most lubricious UAS was the NHD (0.055 lbs for 12F). The NHD (0.277 lbs) required the least insertional force through a biological model and possessed the greatest radio-opacity. Conclusions: Comparison of different commercially available UAS in various sizes reveals that there are mechanical differences in sheaths that may play a role clinically. The Terumo sheaths' (GW and PW) were outperformed by the Boston Scientific NHD in simulating safety, ease of use and radio-opacity.

Experiencia en el manejo de litiasis renal y ureteral con ureteroscopio flexible y láser holmium en un hospital público de Bogotá: estudio retrospectivo / Experience in the management of renal and ureteral calculi with holmium laser and flexible ureteroscope in a public hospital in Bogotá: A retrospective study

Objetivos Discutir y evaluar la tasa libre de cálculos y las complicaciones de la ureterolitotomía endoscópica flexible con láser holmium en el manejo de cálculos ureterales y renales basada en la experiencia de un hospital público de iii nivel en Bogotá. Material and Métodos Estudio retrospectivo en una muestra poblacional en pacientes con litiasis renal y ureteral, tratados con ureteroscopio flexible y láser holmium, evaluándose la tasa libre de cálculos, complicaciones postoperatorias y otros parámetros. El seguimiento se realizó con radiografía de abdomen y urotac al mes del postoperatorio, la tasa libre de cálculos se definió como ausencia de cálculos residuales < 4 mm en la imagen control. Resultados Se realizaron 44 procedimientos en 43 pacientes con edad promedio de 45 años, tiempo quirúrgico promedio 91,2 min, la tasa libre de cálculos fue del 84% (37/44) en un solo evento quirúrgico; solo un paciente requirió una segunda intervención con posterior tasa libre de cálculos del 100%. La tasa libre de cálculos ureterales fue del 92% (24/26), cáliz superior 100% (2/2), cáliz medio 100%(1/1), cáliz inferior 78% (7/9) y calicial múltiple 50% (3/6). El porcentaje de complicaciones fue del 6,8%. Conclusiones La ureterolitotomía endoscópica flexible con láser es un procedimiento efectivo y seguro en el manejo de litiasis renal y ureteral con baja incidencia de complicaciones. Observamos que en la mayoría de los pacientes con fragmentos residuales significativos estos se encontraban en cáliz inferior o se trataba de cálculos en múltiples cálices, explicándose por el difícil acceso al cáliz inferior y la carga litiásica.

Objective To discuss and review the stone free rate and complications of using flexible ureteroscopy and holmium laser lithotripsy for treating patients with kidney and ureteral stones, based on the experience in a level III public hospital in Bogotá. Materials and Methods A retrospective review was conducted on patients with renal and ureteral stones treated with flexible ureteroscopy and holmium laser, by analysing the stone-free rate and postoperative complications. X-rays or computed tomography was performed at 30 days post-operation to assess the effects of surgery, and the stone-free rate was defined as absence of residual stones < 4 mm on follow-up imaging. Results A total of 44 procedures were performed on 43 patients with a mean age of 45 years. The mean operating time was 91.2 minutes, and the stone-free rate in a single surgical event was 84% (37/44). Only one patient required a second intervention, with a subsequent stone-free rate of 100%. The ureteral stone-free rate was 92% (24/26), with upper calyx 100% (2/2), middle calyx 100% (1/1), 78% lower calyx (7/9), and multiple calyceal 50% (3/6). The complication rate was 6.8%. Conclusions Flexible ureteroscopy and holmium laser lithotripsy is an effective and safe procedure in the management of renal and ureteral stones, with a low incidence of postoperative complications. It was noted that most patients with significant residual fragments, they were in lower calyx or had multiple stones. This was explained by the difficult access to the lower calyx and stone burden.

Evaluation of the Spies TM modalities image quality

Introduction The Spies™ system (Karl-Storz®) was introduced into digital ureteroscopy to improve endoscopic vision. To date, there is no data to either indicate which of the Spies modalities is better for improving diagnosis and treatment procedures, nor to compare the modalities in terms of image quality. The aim of this study was to evaluate and compare the image quality of five Spies™ modalities (SM) to the standard white light in an in-vitro model. Materials and Methods Two standardized grids and 3 stones of different composition were recorded in white light and the 5SM (Clara, Chroma, Clara+Chroma), Spectra A and B) using 4 standardized aqueous scenarios. Twelve templates were done in order to simultaneously compare the same objective in the different modalities. Six urologists, five medical students, five urology residents, and five persons not involved with urology evaluated each video on a scale of 1 (very bad) to 5 (very good). Results Comparing white light to SM, subjects scored better the quality of Clara and Clara+Chroma than white light (p=0.0139 and p<0.05) and scored worse Spectra A and B (p=0.0005 and p=0.0023)). When comparing Clara to the other SM, it was ranked equivalent to Clara+Chroma (p=0.67) and obtained a higher rank than Chroma, Spectra A and B (p<0.05, p=0.0001 and p=0.0001). In the multivariate analysis mean scores were higher among urologists. Conclusion In all analyzed scenarios, the subjects ranked Clara and Clara+Chroma as the modalities with better image quality compared to white light.

Intraparenchymal hematoma as a late complication of retrograde intrarenal surgery

ABSTRACT A 34 year-old woman was admitted to our hospital with left flank pain. A non-contrast enhanced computerized tomography (NCCT) revealed a 1.5x2cm left proximal ureter stone. Patient was scheduled for ureterorenoscopy (URS) and stone removal. She was submitted to retrograde intrarenal surgery (RIRS). At the postoperative 1st day, the patient began to suffer from left flank pain. A NCCT was taken, which revealed a subcapsular hematoma and perirenal fluid. The patient was managed conservatively with intravenous fluid, antibiotic and non-steroidal anti-inflammatory drug therapy and was discharged at the postoperative 6th day. Two weeks after the discharge the patient was admitted to emergency department with severe left flank pain, palpitation and malaise. KUB (kidney-ureter-bladder) radiography showed double-J stent (DJS) to be repositioned to the proximal ureter. Patient was evaluated with contrast enhanced CT which revealed an 8cm intraparenchymal hematoma/abscess in the middle part of the kidney. A percutaneous drainage catheter was inserted into the collection. The percutaneous drainage catheter and the DJS were removed at the 10th day of second hospitalization. RIRS surgery is an effective and feasible choice for renal stones with high success and acceptable complication rates. However, clinician should be alert to possible complications.

Is There A Difference Between Presence of Single Stone And Multiple Stones in Flexible Ureterorenoscopy And Laser Lithotripsy For Renal Stone Burden < 300mm2 ?

ABSTRACT In this study, we aim to evaluate and compare the effectiveness of flexible ureterorenoscopy (f-URS) for solitary and multiple renal stones with <300 mm2 stone burden. Patients' charts who treated with f-URS for kidney stone between January 2010 and June 2015 were reviewed, retrospectively. Patients with solitary kidney stones (n:111) were enrolled in group 1. We selected 111 patients with multiple kidney stones to serve as the control group and the patients were matched at a 1:1 ratio with respect to the patient's age, gender, body mass index and stone burden. Additionally, patients with multiple stones were divided into two groups according to the presence or abscence of lower pole stones. Stone free status was accepted as complete stone clearence and presence of residual fragments < 2 mm. According to the study design; age, stone burden, body mass index were comparable between groups. The mean operation time was longer in group 2 (p= 0.229). However, the mean fluoroscopy screening time in group 1 and in group 2 was 2.1±1.7 and 2.6±1.5 min, respectively and significantly longer in patients with multiple renal stones (P=0.043). The stone-free status was significantly higher in patients with solitary renal stones after a single session procedure (p=0.02). After third month follow up, overall success rate was 92.7% in Group 1 and 86.4% in Group 2. Our study revealed that F-URS achieved better stone free status in solitary renal stones <300 mm2. However, outcomes of F-URS were acceptable in patients with multiple stones.

A prospective multicenter European study on flexible ureterorenoscopy for the management of renal stone

ABSTRACT Purpose The aim of this study was to describe the outcomes and the complications of retrograde intrarenal surgery (RIRS) for renal stones in a multi-institutional working group. Materials and Methods From 2012 to 2014, we conducted a prospective study including all RIRS performed for kidney stones in 4 European centers. Demographic information, disease characteristics, and perioperative and postoperative data were gathered. Patients and stone data, procedure characteristics, results and safety outcomes were analyzed and compared by descriptive statistics. Complications were reported using the standardized Clavien system. Results Three hundred and fifty-six patients underwent 377 RIRS with holmium laser lithotripsy for renal stones. The RIRS was completed in all patients with a mean operative time of 63.5 min. The stone-free status was confirmed endoscopically and through fluoroscopic imaging after the first procedure in 73.6%. The second procedure was performed in twenty patients (5.6%) achieving an overall stone free rate of 78.9%. The overall complication rate was 15.1%. Intra-operative and post-operative complications were seen in 24 (6.7%) and 30 (8.4%) cases, respectively. Conclusions RIRS is a minimally invasive procedure with good results in terms of stone-free and complications rate.