Endourological Practice Research Articles

A machine learning approach using stone volume to predict stone-free status at ureteroscopy.

To develop a predictive model incorporating stone volume along with other clinical and radiological factors to predict stone-free (SF) status at ureteroscopy (URS). Retrospective analysis of patients undergoing URS for kidney stone disease at our institution from 2012 to 2021. SF status was defined as stone fragments < 2mm at the end of the procedure confirmed endoscopically and no evidence of stone fragments > 2mm at XR KUB or US KUB at 3months follow up. We specifically included all non-SF patients to optimise our algorithm for identifying instances with residual stone burden. SF patients were also randomly sampled over the same time period to ensure a more balanced dataset for ML prediction. Stone volumes were measured using preprocedural CT and combined with 19 other clinical and radiological factors. A bagged trees machine learning model with cross-validation was used for this analysis. 330 patients were included (SF: n = 276, not SF: n = 54, mean age 59.5 ± 16.1years). A fivefold cross validated RUSboosted trees model has an accuracy of 74.5% and AUC of 0.82. The model sensitivity and specificity were 75% and 72.2% respectively. Variable importance analysis identified total stone volume (17.7% of total importance), operation time (14.3%), age (12.9%) and stone composition (10.9%) as important factors in predicting non-SF patients. Single and cumulative stone size which are commonly used in current practice to guide management, only represented 9.4% and 4.7% of total importance, respectively. Machine learning can be used to predict patients that will be SF at the time of URS. Total stone volume appears to be more important than stone size in predicting SF status. Our findings could be used to optimise patient counselling and highlight an increasing role of stone volume to guide endourological practice and future guidelines.

Ocular radiation exposure is negligible in normal volume endourological practice.

The annual dose limit for radiation exposure to the eye has been reduced recently; the eye is widely recognised as one of the most radiosensitive tissues in the body. There is minimal good quality research as to the radiation dose that the eye receives during endourological surgery and this study aimed to address this. A prospective study was performed over an 8-month period at a single large teaching hospital in the UK. Three index procedures were included: ureteric stent insertion, ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL). Surgeons wore a dosimeter on the glabella with fluoroscopy time (FT) and dose area product (DAP) recorded for each case. A total of 404 procedures were included (247 URSs, 150 ureteric stent insertions and 7 PCNLs). Dosimeters were worn by ten surgeons. Mean FTs (URS 20.56s; ureteric stent 18.96s; PCNL 360.67s) and mean DAP (URS 100.82cGy/m2, ureteric stent 119.82cGy/m2 and PCNL 1121.62cGy/m2) were identified with significant intersurgeon variability. No surgeon had a total dosimeter dose >0.00mSv. The International Commission on Radiological Protection recently reduced the yearly eye dose limit from 150 to 20mSv. Cataractogenesis is no longer considered a typical deterministic effect, with a threshold level below which no effect occurs. Even in higher volume centres, these annual limits are unlikely to be reached. Lead glasses may be considered for surgeons and radiologists with the highest exposure but, for the majority, ocular radiation exposure is negligible.

The Pattern of Day Case (Ambulatory) Percutaneous (PCNL): A Descriptive Retrospective Study from a Tertiary Care Hospital

Background: Percutaneous nephrolithotomy (PCNL) has experienced remarkable development and alteration since it was first described in 1976 by Fernstorm et al. It has also experienced miniaturization of equipment, improvement in operative systems, and refining renal access methods leading to the achievement of maximum clearance of stone while causing minimal morbidity. For example, in endourological practice, when the patient is subjected to PCNL, he traditionally needs programmed inpatient admission, as part of their recovery, it is applicable as an outpatient method in properly selected cases. Objectives: We aimed at evaluating the safety and applicability of the outpatient PCNL procedure. Methods: This retrospective study was done on 210 cases of tubeless PCNL performed by a single urologist at our institute from January 2016 to January 2019. Patients’ mean age (134 males and 76 females) was 57 ± 11.8 years, and 7 patients aged 8 - 12 years. There were 71 pelvic or calyceal solitary stones, 62 non-complete staghorn stones, 17 ureteral stones, 32 renal + ureteric stones (simultaneous renal and ureteral stones) , and 28 complete staghorn stones. The average stone size was 3.5 ± 2.8 (range: 0.7 to 11.8 cm). Results: The mean operation duration was 85.0 ± 29.4 min, and the mean hospital stay was 21.7 ± 3.4 h. Out of 210 patients, 6 patients had longer stay due to high-grade fever and 3 patients due to severe pain, and also 7 patients refused discharge due to personal and social reasons. Our ambulatory PCNL rate was 97 % ( 194 out of 210). Within 72 h, 5 patients were readmitted due to high-grade fever, 3 patients due to haematuria, and 4 patients due to pain and dysuria, and all patients were discharged 2 - 4 days after conservative treatment. Thus, the readmission rate was 6.18% (12 cases were readmitted out of 194 cases). Patients showed a blood transfusion rate of 1.4 %. Also, 19 cases (9.02%) were found with post-operative fever, and no urosepsis was reported. No pulmonary complications and mortality were noted. No re-exploration was done, and no major leak was noted. The angio-embolization rate was 0.59%. We did not use HEMO-SEAL technology, cautery, or suture in the tracks. Conclusions: In conclusion, the outpatient PCNL procedure is an applicable and feasible procedure under selected criteria; however, more investigations using a larger sample size are needed.

A comparative study of efficacy of tamsulosin monotherapy vs. combined (Solifenacin + tamsulosin) in treatment of ureteric stent related symptoms

Ureteric Double J stenting is the most common in endourological practice. The double-J stent, which is the most common form of ureteral stent, is used in obstructive pyelonephritis, intolerable acute renal colic, ureteral edema, ureter perforation following endoscopic procedures. Post stenting commonly reported symptoms include flank pain, haematuria, dysuria, frequency, and urgency. Tamsulosin acts as a selective inhibitor of α1A/1D and Solifenacin acts as a muscarinic receptor antagonist have been used in alleviating the symptoms and have been proved effective. Objective: To study the efficacy of tamsulosin monotherapy vs. combined (solifenacin + tamsulosin) in treatment of ureteric stent related symptoms.Methodology: The prospective control study conducted in R.L. Jalappa Hospital, Tamaka, Kolar. The study included 60 subjects divided on even and odd method with 30 in each group with a period of 3 months. The subjects in group A received oral Tamsulosin of 0.4mg once daily and group B received oral Tamsulosin+ solifenacin (0.4mg+6mg) once daily. The subjects were observed for post-operative complications like flank pain, dysuria and sexual dysfunction. The dysuria was calculated according to Boysarky score and UTI with grading. The data were collected and analysed statistically.Results: The most common age group of presentation of subjects were less than 40 years i.e 22(36.66%) with next common group was 51-60 years accounting 15(25%) with mean age being 45.5 years. The combined therapy group accounted most of the subjects in grade I 23(38.33%) showing significant reduction of post-operative dysuria compared to monotherapy. The combined therapy group had 6 patients with only one patient had grade III UTI. The monotherapy group had 7 subjects developing UTI with grade II being most common. The commonest organism on culture was E. Coli in 9 subjects. There was a significant difference between two groups in reducing UTI. Conclusion: The present study in treatment of DJ stent related symptoms shows combined therapy being more beneficial in terms of reducing post stenting flank pain, dysuria and UTI development in comparison to monotherapy.

Can the Urologists Perform Stone Analysis, Metabolic Evaluation and Metaphylaxis at Urinary Tract Stone Disease in Tekirdağ?

Objective: As the urolithiasis is an endemic situation in our country, the urologists are well-experienced about this situation. The prevention of urolithiasis recurrence is as important as the surgical treatment. For this reason metabolic evaluation and medical treatment of stone disease is extremely important. This study aimed to evaluate urological specialists' views of metabolic evaluation and medical treatment of urolithiasis. Thus, the main problems and the probable solutions about medical treatment and metabolic evaluation of urinary system stone disease can be evaluated. Methods: The urologists working at Tekirdag were invited to the study. A face-to-face questionnaire, which was composed of three parts, was performed to the participants. In the first section, the demographic characteristics of the participants were evaluated. In the second and third sections, the approach of participants to metabolic evaluation and medical treatment in urolithiasis were investigated, respectively. Results: A total of 29 urologist who routinely performed endourological surgery were included to the study. When we evaluated their endourological practice, 65.5% of the participants were performing 10-25 endourological surgery per month. When we asked the approach of participants about the metabolic evaluation, 34.5% reported that they did not perform metabolic evaluation to their adult patients and 65.5% did not perform to the children with urolithiasis. All participants believed the efficacy of medical treatment however, 66% of the participants were performing at less than half of their patients in clinical practice. Conclusions: The clinical practice about metabolic evaluation, stone analysis and metaphylaxis were lower than expected. Most of the participants were not able to make metabolic evaluation and stone analysis. Further studies are needed to resolve the problems associated with metabolic evaluation and metaphylaxis administration.

Systematic review of ureteral access sheaths: facts and myths.

The aim of the present paper was to review the literature on all available ureteral access sheaths (UASs) with their indications, limitations, risks, advantages and disadvantages in current modern endourological practice. Two authors searched Medline, Scopus, Embase and Web of Science databases to identify studies on UASs published in English. No time period restriction was applied. All original articles reporting outcomes or innovations were included. Additional articles identified through references lists were also included. Case reports, editorials, letters, review articles and meeting abstracts were excluded. A total of 754 abstracts were screened, 176 original articles were assessed for eligibility and 83 articles were included in the review. Based on a low level of evidence, UASs increase irrigation flow during flexible ureteroscopy and decrease intrapelvic pressure and probably infectious complications. Data were controversial and sparse on the impact of UASs on multiple reinsertions and withdrawals of a ureteroscope, stone-free rates, ureteroscope protection or damage, postoperative pain, risk of ureteral strictures, and also on its cost-effectiveness. Studies on the benefit of UASs in paediatrics and in patients with a coagulopathy were inconclusive. In the absence of good randomized data, the true impact of UASs on surgery outcome remains unclear. The present review may contribute to the evidence-based decision-making process at the individual patient level regarding whether or not a UAS should be used.

Outcome from 5-year live surgical demonstrations in urinary stone treatment: are outcomes compromised?

PurposeTo compare intra- and post-operative outcomes of endourological live surgical demonstrations (LSDs) and routine surgical practice (RSP) for urinary stones.MethodsConsecutive ureterorenoscopic (URS) and percutaneous (PNL) urinary stone procedures over a 5-year period were reviewed. Procedures were divided into LSDs and RSP. Differences between the groups were separately analysed for URS and PNL. Primary outcomes included intra- and post-operative complication rates and grades. Secondary outcomes were operation time, length of hospital stay, stone-free rate, and retreatment rate. Pearson’s Chi-square analysis, Mann–Whitney U test, and logistic and linear regression were used to compare outcomes between LSDs and RSP.ResultsDuring the study period, we performed 666 URSs and 182 PNLs, and 151 of these procedures were LSDs. Among URSs, the overall intra-operative complication rate was 3.2% for LSDs and 2.5% for RSP (p = 0.72) and the overall post-operative complication rate was 13.7% for LSDs and 8.8% for RSP (p = 0.13). Among PNLs, the overall intra-operative complication rate was 8.9% for LSDs and 5.6% for RSP (p = 0.52) and the overall post-operative complication rate was 28.6% for LSDs and 34.9% for RSP (p = 0.40). For both URSs and PNLs, no statistically significant differences in complication grade scores were observed between LSDs and RSP. Operation time was significantly longer for LSD-URS group, but there was no difference between the PNL groups. There were no significant differences in length of hospital stay and stone-free rate. The retreatment rate was higher in the LSD-URS group compared with RSP-URS group but similar between the PNL groups. Multiple logistic regression analyses, adjusting for confounders, revealed no association between LSD and more or less favourable outcomes as compared to RSP.ConclusionLive surgical demonstrations do not seem to compromise patients’ safety and outcomes when performed by specialised endourologists.

Forgotten Ureteral Stents in a Tertiary Hospital in Accra and a Review of Endourological Management of Upper Urinary Tract Pathologies in the West Africa Sub-Region

Background: Forgotten ureteral stent is defined as prolong indwelling ureteral stent whose function is no longer desired. Ureteral stents are used in the management of upper urinary tract pathologies. Prolonged indwelling ureteral stents may be complicated by urosepsis or renal failure, encrustation, stone formation, spontaneous fracture which may either be retained or voided in the urine (stenturia). Hitherto, these complications were managed by open procedures alone in our center. We report our recent experience in endourology with the management of three cases of forgotten ureteral stents with durations of ten years and two years (two cases) and review endourological practice in West Africa. Conclusion: Although encrusted stents can be managed successfully by minimally invasive approaches in the majority of cases, the best treatment is prevention. Urology units should have preferably an electronic stent register such that when the time for removal is due, the patient's name and details are flagged red. If electronic register is not available, then a hard paper/book register should be made to prevent situations of forgotten stents. Also, efforts must be made to improve endourological services in the West Africa subregion to allow patients to have the benefit of endourology in the management of upper urinary tract pathologies including that of stones originating from an encrusted or fractured forgotten ureteral stent.

Day case endourology in surgical outpatient clinic at Ibadan: A 5 year review

To review our day case endourological practice over a five-year period. Data was obtained from the endourology day case register and these were analysed using simple statistical methods. Caudal anaesthesia and intravenous sedatives were used for the procedures. A total of 559 patients underwent endoscopic procedures as day cases. Their ages ranged from 10 to 88 years, with a male to female ratio of 4 to 1. Four hundred and thirty eight (78.4%) were diagnostic and 121 (21.6%) were therapeutic. The main diagnostic procedures were urethrocystoscopy ( n = 222), and cystoscopy alone ( n = 116), cystoscopy and biopsy ( n = 46) while the therapeutic procedures were direct visual internal urethrotomy ( n = 86), endoscopic cystolitholapaxy ( n = 10), and rigid retrograde endoscopic realignment ( n = 7) for posterior urethral injury. The main anaesthesia was caudal block in 472 patients and topical 2% xylocaine jelly with sedation in 86 patients. There is a steady increase in therapeutic day case endourology. Caudal anaesthesia provides effective pain free procedure to the patient. Surgical trainees can benefit by learning the technique of caudal block anaesthesia.

The new Invisio® DUR-D ‘chip-on-the-tip’ digital flexible ureterorenoscopes: evaluation of changes in physical properties over time

Background & purpose: Flexible ureterorenoscopes (fURSs) have become an essential tool in endourological practice. In 2006, a new generation of digital fURSs (Invisio® DUR-D, ACMI, USA) with new optical technology was introduced. We have compared both light intensity and deflection angles, with and without indwelling instruments, between identical scopes of different number of uses to evaluate changes in physical properties over time. Materials & methods: On three identical Invisio DUR-D digital flexible ureteroscopes of different usages we measured and compared the light intensity. Measurements were taken three times each with the ureteroscopes in straight position and maximum upwards and downwards deflection, respectively. The first scope was brand new; the second had been used 30 times while the third had been used 44 times. We also measured and compared the deflection angles without and with widely used accessory instruments inside the working channel in four identical scopes after 0, 10, 30 and 44 us...

Use of Memokath 051 Metallic Stent in the Management of Ureteral Strictures: A Single-Center Experience

Introduction: Memokath 051® represents a nickel-titanium stent that has been used to treat patients with incurable ureteral strictures. In the current study we present our experience in using this technique. Materials and Methods: Between 2003 and 2008, 19 metallic stents were placed in 13 patients. All of them had been previously treated by using JJ stents or dilatation. The etiology was benign in 10, while in 3 patients malignancy was involved. The mean age was 60.7 years. Mean stricture length was 3.2 cm while the median stent length was 6 cm. No severe complications were noticed postoperatively. Mean follow-up was 14.3 months. Results: Six patients (46%) experienced a satisfactory result after first insertion. Stent migration was observed in 6 patients and in 3 it was replaced successfully. One patient was offered a simple nephrectomy due to a poorly functioning kidney. Eventually, 10 of 13 patients (77%) had a successful outcome after the final stent insertion. Conclusion: Memokath stents suggest a possible alternative in treating chronic/recurrent ureteral strictures. Their most important disadvantage seems to be migration. Their role in endourological practice remains to be validated.

Efficacy and safety of the Accordion® stone-trapping device: in vitro results from an artificial ureterolithotripsy model

One of the challenges of intracorporeal ureterolithotripsy is undesired stone migration. Stone-trapping devices have been designed to prevent this quite common phenomenon. These devices have to be effective in terms of ureteral obstruction and safe in terms of resistance to the action of commonly used lithotriptors. This work was conducted to evaluate the efficacy and safety of the recently approved Accordion stone-trapping device in vitro. In a rigid, submerged ureteral model with two different diameters (8 and 10 mm), artificial stones were positioned in direct contact with the engaged Accordion device. A defined number of pneumatic pulses of the LithoClast master at different performance levels was applied and the migration distance of the stone was measured after each single pulse. As a control, the same series was repeated without the stone-trapping device. Secondly, the Accordion device was exposed to a previously defined number of pneumatic or Ho:YAG-laser pulses, in direct contact with the lithotripsy probe, up to a total activation time of 2 min. At different time points, the device was controlled for damage and functionality. The mean stone migration distance without the Accordion device was between 39.2 and 52.8 mm and between 37.8 and 75.4 mm in the 8 and 10 mm tubes, respectively. In comparison, the stone or fragment travelling distance with the device was in the 0-2 mm range. This difference was highly significant. Both pneumatic and laser lithotriptor did not affect the functionality of the Accordion device. The Ho:YAG laser causes small perforations of the film without affecting the devices' stability. The Accordion device appears to be highly efficient and safe in vitro. Clinical trials will have to assess its value in endourological practice. Randomised comparative trials comparing different stone-trapping devices are needed.

The forgotten ureteric JJ stent and its prevention: a prospective audit of the value of a ureteric stent logbook

Temporary ureteric stent insertion is an integral part of modern endo-urological practice. Delayed stent removal or forgotten stents are associated with increased patient morbidity and complications which are often difficult to manage. We prospectively audited our ureteric stent insertion and removal logbook system to determine the value and effectiveness of our stent follow-up. Over a 1-year period, 210 ureteric stents were inserted in our urological unit. Of these, 47 (22.4%) patients were unaccounted as having their stents removed within the stent logbooks. One patient was lost to follow-up and re-presented with stent encrustation 10 months later. Our results in this audit suggest that our system of ureteric stent follow-up is not effective. We have now introduced a new system that we feel is a safer and a satisfactory alternative to the stent logbooks. This includes a patient education leaflet and removal date scheduling prior to discharge from hospital.

Spectrum of urological procedures in University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria.

To determine the relative frequencies of types of operations, age and gender distribution of the patients and the indications for operation in the Urology Unit over a 10-year period between 1989 and 1998. The Urology Unit of the University of Port Harcourt Teaching Hospital. Retrospective. Patients' demographic data were collected from the Main Theatre registers of the Hospital, the Medical Records Department ward records patients' and case note. Those operations done in the Urology Unit were analysed. Urological operations (total 1875) formed 22.6% of all surgical operations in the hospital during the decade under review. There were 1847 males (98.5%) and 28 females (1.5%). The age distribution showed two peaks in the first decade and in the seventh decade. Frequencies of operations were least in the 4th decade and after the 9th decade. Circumcisions, surgery for prostate disease, procedures for urethral strictures, urological trauma and paediatric reconstruction formed the majority of operations. Endoscopic urological procedures were limited to the occasional cystoscopy. Some 67.6% of the operations were performed in the first half of the decade and 32.4% in the second half. A rapid decrease in the number of operations was noticed which compared with the same pattern in the Department of Surgery as a whole. We recommend the establishment and development of human and material resources for Urological service for basic procedures and endo-urological practice in keeping with contemporary trends and the allocation of more theatre space and out-patient Clinic time to the urology service.

Endourology in a Nigerian Tertiary Hospital – current level of practice and challenges

Background : Endourology is rapidly advancing in developed countries. However, the level of practice in public tertiary hospitals in developing countries is abysmally low. Objective : To review the current practice of endourology in a Nigerian public tertiary hospital and discuss the challenges faced during the study period. Setting : This review was done at the urology unit of the Obafemi Awolowo University Teaching Hospitals Complex [OAUTHC], Ile-Ife, Nigeria. Materials and Methods : A retrospective review of medical notes of all patients who have had diagnostic and therapeutic endourological procedure in our practice between June 2002 and May 2004 was carried out Results : Forty nine medical notes were available for review. A total of 51 procedures were carried out, representing twenty percent of the total urological procedures done by the unit during the study period. The commonest indication for an endourological procedure was bladder outlet obstruction. The commonest procedure performed was urethrocystoscopy. There was one complication and one failed procedure. Conclusion : Although endourological applications have many advantages over open urological procedures, endourological practice is low due to lack of equipment personnel and funding. Advances in endourological practice are desired and this will require improvement in infrastructure, training of personnel and a whole reorientation in our choices of the care we give our patients. Keywords : endourology, scope, challenges Nigerian Journal of Surgical Research Vol. 7(3&4) 2005: 268-270

INTERNET AND POSTAL SURVEY OF ENDOUROLOGIC PRACTICE PATTERNS AMONG AMERICAN UROLOGISTS

We determine endourological practice patterns among American urologists for the management of distal ureteral calculi, ureteropelvic junction obstruction, staghorn calculi and the use of ureteral stents with extracorporeal shock wave lithotripsy (ESWLdagger). Surveys were mailed by the United States postal service to 1,000 American urologists selected randomly from the American Urological Association membership roster. The same survey was sent via the Internet to 3,065 American urologists with an electronic mail address listed in the roster. Responses were received from 1,029 urologists (postal 601, Internet 428). Ureteroscopy was the preferred treatment for all distal ureteral calculi less than or equal to 10 mm. Acucisedouble dagger endopyelotomy was the most frequently selected therapy for adults with ureteropelvic junction obstruction (50.3%, 514 of 1,022). Open pyeloplasty was recommended by a significantly greater percentage of urologists in practice longer than 15 years compared with the remaining survey respondents (166 of 485, 34.2% versus 92 of 427, 21.5%). For patients with renal pelvic stones 10, 15 or 20 mm. who are treated with ESWL routine stent placement was preferred by 25.3% (259 of 1,022), 57.1% (584 of 1,022) and 87.1% (888 of 1, 019) of urologists, respectively. Percutaneous nephrolithotomy was preferred for patients with staghorn calculi by 80.5% (828 of 1,028) of survey respondents. Most urologists follow the American Urological Association practice guidelines for patients with distal ureteral calculi and staghorn stones. There is a significant difference of opinion regarding the use of stents with ESWL. No clear consensus has been reached concerning the management of adults with ureteropelvic junction obstruction. These data may be useful in designing physician education programs and/or future investigations to help define standard treatment practices for urological diseases.

Percutaneous flexible fiberoptic nephroscopy

The flexible fiberoptic nephroscope is a useful endourological tool. This paper describes the characteristics of this flexible nephroscope, various useful accessory devices and their limitations and the basic technique for percutaneous flexible nephroscopy. The limitations of the flexible nephroscope are outlined along with aids to overcome these shortcomings. Specific use of the flexible nephroscope for particular types and provisions of stones are also described. Finally, a summary of the utility of the flexible nephroscope in a busy endourological practice is outlined.