Diameter of ureteral access sheath and ureteral stenosis development: a systematic review

Purpose: Ureteral access sheaths (UAS) are widely used in ureteroscopy. UAS are believed to pose a significant risk for ureteral stenosis due to ureteral mucosal compression, but little evidence supports this claim. Our systematic review aimed to investigate the relationship between different UAS diameters and stenosis risk. Methods: A systematic search was conducted in PubMed, Embase, Web of Science, Scopus, and Cochrane, from its inception to May 2023. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane guidelines were followed. χ2 test was performed to compare the prevalence within the groups. Results: Six nonrandomized trials and one randomized, with a total of 962 patients, were included. The overall incidence of ureteral stenosis of 0.9%. UAS sizes were: 9.5/11.5Fr, 10/12Fr, 11/13Fr, 12/14Fr, and 14/16Fr. Within each subgroup, the incidence of ureteral stenosis was: 0.4, 8, 0, 1, and 1% (p = 0.099). No trend for stenosis was observed among larger UAS. Conclusions: In this systematic review, no relationship between UAS diameter and incidence of ureteral stenosis was observed. Nonetheless, additional randomized controlled trials are required to support this finding.

Does displacement of lower pole stones during retrograde intrarenal surgery improves stone-free status?: a systematic review and meta-analysis

Purpose: Kidney stones are one of the most common urological diseases worldwide. The size and location of the stone are the most important factors in determining the most suitable treatment options. The aim of this review was to evaluate the displacement of lower pole stones. Methods: Three studies assessing the efficacy of translocating kidney stones from the lower pole of the kidney to other locations during retrograde intrarenal surgery published in the last 20 years were included. A systematic search was conducted in the PubMed, Embase, Latin American and Caribbean Health Sciences Literature (LILACS), and Web of Science databases using the following search terms: "Lower pole," "Lithotripsy." Meta-analysis was performed using Review Manager version 5.4. Results: Stone-free rates were improved through displacement (odds ratio - OR = -0.15; 95% confidence interval-95%CI -0.24--0.05; p = 0.002; I2 = 21%), but at the cost of increased surgical duration (mean difference = -12.50; 95%CI -24.06--0.95; p = 0.03; I2 = 94%). Although this represents a potentially negative outcome, the improvement in clearance rates justifies the additional investment of time and effort. Conclusions: Displacement of lower pole kidney stones for subsequent lithotripsy brings significant benefits in terms of stone-free rate, with no difference in laser energy usage. However, it results in increased surgical time. Despite these factors, the benefits to patients undergoing the procedure are substantial.

Comparison of safety and effectiveness of active migration technique and in situ lithotripsy technique in the treatment of 1-2 cm upper ureteral calculi by flexible ure-teroscopy / 北京大学学报(医学版)

OBJECTIVE@#To compare the safety and effectiveness of active migration technique and in situ lithotripsy technique in the treatment of 1-2 cm upper ureteral calculi by retrograde flexible ureteroscopy.@*METHODS@#A total of 90 patients with 1-2 cm upper ureteral calculi treated in the urology department of Beijing Friendship Hospital from August 2018 to August 2020 were selected as the subjects. The patients were divided into two groups using random number table: 45 patients in group A were treated with in situ lithotripsy and 45 patients in group B were treated with active migration technique. The active migration technique was to reposition the stones in the renal calyces convenient for lithotripsy with the help of body position change, water flow scouring, laser impact or basket displacement, and then conduct laser lithotripsy and stone extraction. The data of the patients before and after operation were collected and statistically analyzed.@*RESULTS@#The age of the patients in group A was (51.6±14.1) years, including 34 males and 11 females. The stone diameter was (1.48±0.24) cm, and the stone density was (897.8±175.9) Hu. The stones were located on the left in 26 cases and on the right in 19 cases. There were 8 cases with no hydronephrosis, 20 cases with grade Ⅰ hydronephrosis, 11 cases with grade Ⅱ hydronephrosis, and 6 cases with grade Ⅲ hydronephrosis. The age of the patients in group B was (51.8±13.7) years, including 30 males and 15 females. The stone diameter was (1.52±0.22) cm, and the stone density was (964.6±214.2) Hu. The stones were located on the left in 22 cases and on the right in 23 cases. There were 10 cases with no hydronephrosis, 23 cases with grade Ⅰ hydronephrosis, 8 cases with grade Ⅱ hydronephrosis, and 4 cases with grade Ⅲ hydronephrosis. There was no significant diffe-rence in general parameters and stone indexes between the two groups. The operation time of group A was (67.1±16.9) min and the lithotripsy time was (38.0±13.2) min. The operation time of group B was (72.2±14.8) min and the lithotripsy time was (40.6±12.6) min. There was no significant difference between the two groups. Four weeks after operation, the stone-free rate in group A was 86.7%, and in group B was 97.8%. There was no significant difference between the two groups. In terms of complications, 25 cases of hematuria, 16 cases of pain, 10 cases of bladder spasm and 4 cases of mild fever occurred in group A. There were 22 cases of hematuria, 13 cases of pain, 12 cases of bladder spasm and 2 cases of mild fever in group B. There was no significant difference between the two groups.@*CONCLUSION@#Active migration technique is safe and effective in the treatment of 1-2 cm upper ureteral calculi.

Effect of moxibustion on ureteral stent-related symptoms after ureteroscopic lithotripsy / 中国针灸

OBJECTIVES@#To observe the clinical efficacy of moxibustion combined with western medication on ureteral stent-related symptoms after ureteroscopic lithotripsy (URL).@*METHODS@#One hundred and fifty patients with upper urinary tract calculus implanted with ureteral stents after URL were randomly divided into a moxibustion group (50 cases, 1 case dropped out), a placebo moxibustion group (50 cases, 3 cases dropped out) and a blank control group (50 cases). No intervention was performed in the blank control group. On the basis of oral administration with tamsulosin hydrochloride sustained release capsule (starting from the first day after surgery, once a day, 0.2 mg each time, continuously for 4 weeks), in the moxibustion group, moxibustion was operated at Guanyuan (CV 4) and bilateral Shenshu (BL 23); the sham-moxibustion was delivered at the same acupoints in the placebo moxibustion group, once daily, 6 times a week, for 15 min in each treatment. The duration of treatment was 4 weeks. Before treatment, and after 1, 2 and 4 weeks of treatment, the scores of lower urinary tract symptoms, body pain, general health, work performance and satisfaction of sexual matters were compared among the 3 groups. The tract calculus clearance rate, urinary infection and the oral administration of painkillers were compared after 4 weeks of treatment in the 3 groups.@*RESULTS@#The scores of lower urinary tract symptoms, body pain and general health after 1 week of treatment, and the scores of lower urinary tract symptoms, body pain, general health and work performance after 2 and 4 weeks of treatment were lower than those before treatment in the 3 groups (P<0.01). The scores of lower urinary tract symptoms and body pain in the moxibustion group after 1, 2 and 4 weeks of treatment were lower than those in the blank control group and the placebo moxibustion group (P<0.01, P<0.05) respectively. The score of general health in the moxibustion group was lower than that in the blank control group after 1 week of treatment (P<0.01), and lower than those of the blank control group and the placebo moxibustion group after 2 and 4 weeks of treatment (P<0.01, P<0.05). Regarding the score of work performance, it was lower in the moxibustion group after 1 and 2 weeks of treatment compared with those in the blank control group (P<0.05, P<0.01), and lower than those of the blank control group and the placebo moxibustion group after 4 weeks of treatment (P<0.01, P<0.05). The tract calculus clearance rate in the moxibustion group was 95.9% (47/49), higher than that in the blank control group (80.0%, 40/50, P<0.05). The proportion of oral administration of painkillers in the moxibustion group (28.6%, 14/49) and the placebo moxibustion group (40.4%, 19/47) was lower than that in the blank control group (76.0%, 38/50, P<0.01) respectively.@*CONCLUSIONS@#Moxibustion combined with western medication relieves lower urinary tract symptoms and body pain, and accelerate the recovery of general health and work performance in the patients after URL.

Diferencias entre el Urocultivo Previo y el cultivo del Catéter doble J. Implicancias clínicas / DIFFERENCES BETWEEN PREVIOUS URINE CULTURE AND DOUBLE J CATHETER CULTURE. CLINICAL IMPLICATIONS

Las infecciones urinarias complicadas, dentro de las cuales se encuentran las asociadas a catéteres, son un hallazgo frecuente de la práctica clínica. Las complicaciones infecciosas después de los procedimientos urológicos son una fuente importante de morbimortalidad y consumen múltiples recursos sanitarios. La colonización bacteriana en el catéter ureteral juega un papel esencial en la patogénesis de la infección, y el uso de profilaxis antimicrobiana en urología es controvertido. El objetivo de nuestro trabajo fue evaluar la utilidad de la profilaxis antibiótica en la extracción del catéter doble J

Complicated urinary infections, among which are those associated with catheters, are a frequent finding in clinical practice. Infectious complications after urological procedures are an important source of morbidity and mortality and consume multiple healthcare resources. Bacterial colonization in the ureteral catheter plays an essential role in the pathogenesis of infection, and the use of antimicrobial prophylaxis in urology is controversial. Te objective of our work was to evaluate the usefulness of antibiotic prophylaxis in the extraction of the double J catheter

A novel upper tract ureteroscopic biopsy technique: the "form tackle"

ABSTRACT Introduction and Objective: Upper tract urothelial carcinoma (UTUC) represents 5% of all urothelial malignancies (1-3). Accurate pathologic diagnosis is key and may direct treatment decisions. Current ureteroscopic biopsy techniques include cold-cup, backloaded cold-cup and stone basket (4-6). The study objective was to compare a standard cold-cup biopsy technique to a novel cold-cup biopsy technique and evaluate histopathologic results. Materials and Methods: We developed a novel UTUC biopsy technique termed the "form tackle" biopsy. Ureteroscope is passed into ureter/renal collecting system. Cold-cup forceps are opened and pressed into the lesion base (to engage the urothelial wall/submucosal tissue) then closed. Ureteroscope/forceps are advanced forward 3-10mm and then extracted from the patient. We compared standard versus novel upper tract biopsy techniques in a series of patients with lesions ≥1cm. In each procedure, two standard and two novel biopsies were obtained from the same lesion. The primary study aim was diagnosis of malignancy. IRB approved: 21-006907. Results: Fourteen procedures performed on 12 patients between June 2020 and March 2021. Twenty-eight specimens sent (14 standard, 14 novel) (Two biopsies per specimen). Ten procedures with concordant pathology. In 4 procedures the novel biopsy technique resulted in a diagnosis of UTUC (2 high-grade, 2 low-grade) in the setting of a benign standard biopsy. Significant difference in pathologic diagnoses was detected between standard and novel upper tract biopsy techniques (p=0.008). Conclusions: The "form tackle" upper tract ureteroscopic biopsy technique provides higher tissue yield which may increase diagnostic accuracy. Further study on additional patients required. Early results are encouraging.

Ureteroscopy Outcome and Its Determinants in a Resource-Limited Setting

Ureteroscopy is a major diagnostic and therapeutic technique for lesions of the ureter and intrarenal collecting system. METHODS: A retrospective chart review was done at St. Paul's Hospital Millennium Medical College, Ethiopia to determine the outcome of ureteroscopy and factors affecting it. The study period was from January 2018 to April 2018. Multivariate analysis was done to determine factors affecting stone clearance and success rate. RESULT: One hundred six patients who underwent semirigid ureteroscopy were included in the study. The male-to-female ratio was 1.8:1. The mean age of the patients was 36.4 years (±12.6). Ninety-six (90.6%) patients were found to have ureteric stones, while 9(8.5%) patients had a ureteric stricture. Ureteroscopy therapeutic interventions for stones were successful in 89 (92.7%) patients. The mean procedure time and postoperative hospital stay were 44 minutes (±23.7) and 2.5 days (±2.5) respectively. Intraoperative complications (ureteric avulsion, hemorrhage, and ureteral perforations) occurred in 6(5.7%) patients. The stone clearance rate was 54.7% (52). The site of obstruction was passed in 93 patients making the success rate of the procedure 87.7%. The absence of intraoperative complications was significantly associated with success rate. Patients with intraoperative complications have low success rate (20%) compared to patients without complications (92.3%), p=0.42. CONCLUSION: Semirigid ureteroscopy had a good success rate, especially for stones in the distal ureter and if there is no flexible ureteroscope, it is an acceptable alternative

Application of ureteral access sheath in the operation of middle and lower ureteral calculi in patients with massive benign prostatic hyperplasia / 中华外科杂志

Objective: To examine the effectiveness and safety of application of the ureteral access sheath in the treatment of middle or lower ureteral calculi in patients with large-volume benign prostatic hyperplasia above grade Ⅲ, which is expected to avoid the simultaneous or staged treatment of benign prostatic hyperplasia via eliminate the difficult angle and resistance of ureteroscopy caused by severe prostatic hyperplasia. Methods: From April 2018 to December 2020, the clinical data of 27 patients with massive benign prostatic hyperplasia above grade Ⅲ and middle and lower ureteral calculi treated with indwelling ureteral access sheath plus ureteroscopy holmium laser lithotripsy at Department of Urology, Zhejiang Quhua Hospital were retrospectively analyzed and followed up. All the patients were male, aged (69.7±12.8) years (range: 55 to 87 years). Prostate volume measured by transrectal ultrasound was (94.8±16.2) cm3 (range: 85 to 186 cm3). The ureteral access sheath was indwelled in advance, and then the semirigid ureteroscopy was introduced through the working channel of the sheath. Holmium laser lithotripsy was performed, and intraoperative and postoperative complications were recorded. Urinary abdominal plain X-ray or CT urography were performed at 1-and 2-month postopaerative to evaluate the residual stones and clinical efficacy. Results: The ureteral access sheath was placed and holmium laser lithotripsy under a semirigid ureteroscopy was performed successfully in all the 27 patients. In 2 patients, a second session of auxiliary procedure was required due to the large load of preoperative stones and residual stones after surgery, among whom 1 patient received extracorporeal shock wave lithotripsy and 1 patient underwent extracorporeal shock wave lithotripsy plus ureteroscopic lithotripsy. The stone free rate at 1-and 2-month postoperative were 92.6% (25/27) and 100% (27/27), respectively. There were no severe complications such as ureteral avulsion and perforation, perirenal hematoma, septic shock, severe hematuria, urinary retention, iatrogenic ureteral stricture occurred during and after the surgery. The ureteral calculus was wrapped by polyps heavily in 1 patient, he was diagnosed as ureteral stenosis 1 month postoperative, receiving laparoscopic resection of ureteral stricture plus anastomosis 3 months postoperative. Conclusions: In the operations of middle and lower ureteral calculi in patients with large-volume prostatic hyperplasia above grade Ⅲ, the ureteral access sheath can be placed first to effectively eliminate the difficult angle and resistance of ureteroscopy caused by severe prostatic hyperplasia, and then semirigid ureteroscopic lithotripsy can be safely performed. It could avoid the treatment of benign prostatic hyperplasia at the same time or by stages.

Value of urine IL-8, NGAL and KIM-1 for the early diagnosis of acute kidney injury in patients with ureteroscopic lithotripsy related urosepsis / 中华创伤杂志(英文版)

PURPOSE@#To investigate the clinical value of urine interleukin-18 (IL-8), neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) for the early diagnosis of acute kidney injury (AKI) in patients with ureteroscopic lithotripsy (URL) related urosepsis.@*METHODS@#A retrospective study was carried out in 157 patients with urosepsis after URL. The patients were divided into AKI group and non-AKI group according to the Kidigo guideline and urine IL-8, NGAL and KIM-1 levels were detected by enzyme-linked immunosorbent assay at 0, 4, 12, 24 and 48 h after the surgery. Receiver operating characteristic curve (ROC) was used to evaluate the diagnostic value of these three biomarkers for postoperative AKI.@*RESULTS@#The level of urine IL-8, NGAL and KIM-1 in AKI group was significantly higher than that in non-AKI group at 4, 12, 24 and 48 h (p < 0.01). The ROC analysis showed the combined detection of urine IL-8, NGAL and KIM-1 at 12 h had a larger area under curve (AUC) than a single marker (0.997, 95% CI: 0.991-0.998), and the sensitivity and specificity were 98.2% and 96.7%, respectively. Pearson correlation analysis showed that the levels of urine NGAL at 4, 12, 24 and 48 h in AKI patients were positively correlated with the levels of urine KIM-1 and IL-18 (p < 0.01).@*CONCLUSION@#AKI could be quickly recognized by the elevated level of urine IL-8, NGAL and KIM-1 in patients with URL-related urosepsis. Combined detection of the three urine biomarkers at 12 h after surgery had a better diagnostic performance, which may be an important reference for the early diagnosis of AKI.

Comparing public interest on stone disease between developed and underdeveloped nations: are search patterns on google trends similar?

ABSTRACT Objective: The big data provided by Google Trends may reveal patterns in health information-seeking behavior on population from Brazil and United States (US). Our objective was to explore and compare patterns of stone disease online information-seeking behaviors in both nations. Materials and Methods: To compare Relative Search Volume (RSV) among different urologic key words we chose "US" and "Brazil" as country and "01/01/2009 - 31/12/2018" as time-range. The final selection included 12 key words in each language. We defined "ureteroscopy" as a reference and compared RSV against it for each term. RSV was adjusted by the reference and normalized in a scale from 0-100. Trend presence was evaluated by Mann Kendall Test and magnitude by Sen's Slope (SS) Estimator. Results: We found an upward trend (p <0.01) in most of the researched terms in both countries. Higher temporal trends were seen for "Kidney Stone" (SS=0.36), "Kidney Pain" (SS=0.39) and "Tamsulosin" (SS=0.21) in the US. Technical treatment terms had little search volumes and no increasing trend. "Kidney Stent" and "Double J" had a significant increase in search trend over time and had a relevant search volume overall in 2018. In Brazil, "Calculo Renal", "Colica Renal", "Dor no Rim" and "Pedra no Rim" had a significant increase in RSV (p <0.001). More common and popular terms as "Kidney Stent" and "Tamsulosin" were highly correlated with "Kidney Pain" and "Kidney Stone" in both countries. Conclusions: In the last decade, there was a significant increase in online search for medical information related to stone-disease. Population from both countries tend to look more for generic terms related to symptoms, the disease, medical management and kidney stent, than for technical treatment vocabulary.

Vantagens custo-efetivas da utilização de ureteroscópios flexíveis descartáveis em comparação com o uso de ureteroscópios flexíveis reprocessáveis / Cost-effective advantages of using disposable flexible ureteroscopes versus using reprocessable flexible ureteroscopes

Objetivo: Analisar o custo-efetividade da utilização de ureteroscópios flexíveis descartáveis em comparação com o uso de ureteroscópios flexíveis reprocessáveis. Métodos: Revisão integrativa de literatura realizada nos bancos de dados SciELO, LILACS e MEDLINE, utilizando os descritores "ureteroscopia", "resistência à flexão", "marketing", "análise de custo-benefício" e "esterilização", cujo objeto trata das vantagens custo-efetivas da utilização do ureteroscópio flexível descartável. Resultados: Trinta e cinco artigos foram encontrados, sendo quatro utilizados no estudo. Além disso, características de sete modelos de ureteroscópios flexíveis comercializados no Brasil mais conhecidos atualmente foram apresentadas. Os resultados foram baseados na análise conjunta dos artigos selecionados e características dos modelos de flexíveis apresentados e discutidos em duas categorias: a evolução dos ureteroscópios flexíveis e marketing mix ­ ureteroscópios flexíveis de uso único. Conclusão: Apesar da escassez de pesquisas que se aprofundem em custos de utilização de um ureteroscópio flexível de uso único, comparado a um reprocessável, são notórios os benefícios advindos das inovações agregadas a esses dispositivos, dando retorno positivo tanto para o profissional que faz seu uso deles quanto para o paciente, fazendo-se necessário analisar mais profundamente a possibilidade de migração da "cultura" de uso de ureteroscópios flexíveis reprocessáveis para os descartáveis

Objective: To analyze the cost-effectiveness of using disposable flexible ureteroscopes versus using reprocessable flexible ureteroscopes. Methods: Integrative literature review conducted in the SciELO, LILACS and MEDLINE databases, using the descriptors ureteroscopy, flexion resistance, marketing, cost-benefit analysis, and sterilization, whose object deals with the cost-effective advantages of using the flexible ureteroscope disposable. Results: Thirty-five articles were found and four were used in the study. In addition, characteristics of seven models of flexible ureteroscopes commercialized in Brazil, that are currently better known, were presented. The results were based on a joint analysis of the selected articles and characteristics of the flexible models presented, and discussed in two categories: the evolution of flexible ureteroscopes; and marketing mix - flexible single-use ureteroscopes. Conclusion: Despite the scarcity of research that deepens the costs of using a flexible single-use ureteroscope when compared to a reprocessable one, the benefits arising from the innovations added to these devices are notorious, giving a positive return both to the professional who uses it and to the patient, making it necessary to further analyze the possibility of migration from the "culture" of using flexible reprocessable ureteroscopes to disposable ones

Distintos enfoques adoptados por los médicos para tratar la nefrolitiasis en pediatría: estudio basado en una encuesta / Different approaches among physicians to treat pediatric stone disease: a survey-based study

Introducción. Los pediatras, cirujanos y subespecialistas, como urólogos y nefrólogos pediátricos, participan en el diagnóstico y tratamiento de la nefrolitiasis pediátrica. El objetivo fue determinar los enfoques de distintas disciplinas y evaluar las diferencias en sus protocolos de diagnóstico y tratamiento habituales.Población y métodos. Cuestionario administrado a participantes de sesiones sobre nefrolitiasis en congresos nacionales en 2017 para evaluar las rutinas de diagnóstico y tratamiento de la nefrolitiasis entre distintas especialidades (cirujanos y pediatras) y subespecialidades (nefrólogos pediátricos y urólogos pediátricos).Resultados. Se analizaron 324 cuestionarios de 88 pediatras, 121 urólogos, 23 cirujanos pediátricos, 54 nefrólogos pediátricos y 38 urólogos pediátricos. Ambos grupos coincidieron en la necesidad de una evaluación metabólica. Para los cálculos ureterales distales ≥6 mm, los cirujanos preferían una ureteroscopía; los pediatras, una litotricia por ondas de choque (LOC) (p < 0,001); y los subespecialistas, una ureteroscopía (p = 0,636). Para los cálculos en la parte inferior de los cálices renales < 1 cm, los cirujanos y los subespecialistas preferían la LOC y los pediatras, la hidratación (p < 0,001; p = 0,371). Para los cálculos de entre 1,1 cm y 2 cm, los cirujanos preferían la cirugía retrógrada intrarrenal (CRIR) y la LOC, y los pediatras, la LOC (p = 0,001). Para los cálculos más grandes, los cirujanos y subespecialistas preferían la nefrolitotomía percutánea (NLP) y los pediatras, la LOC (p = 0,458; p = 0,001).Conclusión. Existen diferencias entre las disciplinas que participan activamente en el diagnóstico y tratamiento de la nefrolitiasis

Introduction. Pediatricians, surgeons and subspecialties as pediatric urology and nephrology are involved in the diagnosis and treatment of pediatric renal stone disease (RSD). The aim of this study was to determine diagnostic and treatment approaches, of different disciplines, and to assess differences in their routine diagnostic and treatment protocols.Population and methods. A questionnaire was designed and administered to the participants of the RSD sessions in national congresses of all disciplines in 2017 to evaluate the diagnostic and treatment routines of specialties (surgeons and pediatricians) and subspecialties (pediatric nephrologists and pediatric urologists) for RSD. Results. A total, of 324 questionnaires were analyzed, from 88 pediatricians (27 %), 121 urologists (37 %), 23 pediatric surgeons (7 %), 54 pediatric nephrologists (17 %), and 38 pediatric urologists (12 %). Both groups agreed on the necessity of metabolic evaluation. For distal ureter stones that were ≥ 6 mm; surgeons preferred ureteroscopy (URS), pediatricians preferred shock wave lithotripsy (SWL) (p < 0.001) and subspecialties preferred URS for the treatment (p = 0.636). For lower calix stones less than 1 cm surgeons and subspecialists preferred SWL, while pediatricians preferred hydration (p < 0.001, p = 0.371). For the stone between 1.1 and 2 cm, surgeons preferred intrarenal surgery (RIRS) and SWL, pediatricians preferred SWL (p = 0.001). For larger stones, surgeons and subspecialists preferred percutaneous nephrolithotomy (PCNL), and pediatricians preferred SWL (p = 0.458 p = 0.001). Pediatric urologist chose low-dose computerized tomography as a diagnostic radiologic evaluation (p = 0.029).Conclusion. There are differences between the disciplines who take an active role in diagnosis and treatment of RSD.

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.