Use of Temporally Validated Machine Learning Models To Predict Outcomes of Percutaneous Nephrolithotomy Using Data from the British Association of Urological Surgeons Percutaneous Nephrolithotomy Audit.

BACKGROUND AND OBJECTIVE: Machine learning (ML) is a subset of artificial intelligence that uses data to build algorithms to predict specific outcomes. Few ML studies have examined percutaneous nephrolithotomy (PCNL) outcomes. Our objective was to build, streamline, temporally validate, and use ML models for prediction of PCNL outcomes (intensive care admission, postoperative infection, transfusion, adjuvant treatment, postoperative complications, visceral injury, and stone-free status at follow-up) using a comprehensive national database (British Association of Urological Surgeons PCNL). METHODS: This was an ML study using data from a prospective national database. Extreme gradient boosting (XGB), deep neural network (DNN), and logistic regression (LR) models were built for each outcome of interest using complete cases only, imputed, and oversampled and imputed/oversampled data sets. All validation was performed with complete cases only. Temporal validation was performed with 2019 data only. A second round used a composite of the most important 11 variables in each model to build the final model for inclusion in the shiny application. We report statistics for prognostic accuracy. KEY FINDINGS AND LIMITATIONS: The database contains 12 810 patients. The final variables included were age, Charlson comorbidity index, preoperative haemoglobin, Guy's stone score, stone location, size of outer sheath, preoperative midstream urine result, primary puncture site, preoperative dimercapto-succinic acid scan, stone size, and image guidance (https://endourology.shinyapps.io/PCNL_Demographics/). The areas under the receiver operating characteristic curve was >0.6 in all cases. CONCLUSIONS AND CLINICAL IMPLICATIONS: This is the largest ML study on PCNL outcomes to date. The models are temporally valid and therefore can be implemented in clinical practice for patient-specific risk profiling. Further work will be conducted to externally validate the models. PATIENT SUMMARY: We applied artificial intelligence to data for patients who underwent a keyhole surgery to remove kidney stones and developed a model to predict outcomes for this procedure. Doctors could use this tool to advise patients about their risk of complications and the outcomes they can expect after this surgery.

Enabling national improvement in quality of care for renal colic.

OBJECTIVES: To report the results of a clinical audit conducted by the British Association of Urological Surgeons (BAUS) of ureteric stone care pathways, with results reported with reference to national quality standards. PATIENTS AND METHODS: The BAUS conducted a clinical audit of all patients presenting as an emergency to 107 hospitals in England during November 2020 with ureteric stones. All patients were followed up until 31 March 2021 and the inpatient and outpatient management received was recorded. RESULTS: Data for 2192 patients across 117 units were submitted. The median (interquartile range [IQR]) number of patients per unit was 16 (9-27); 70% of patients were male and the median (IQR) patient age was 46 (34-59) years. Initial management was conservative treatment for 70% of patients. Overall, primary shockwave lithotripsy was performed in 34% of patients and primary ureteroscopy in 23% of cases when surgical intervention was required to treat the stone. However, 40% of patients in whom active intervention was appropriate underwent placement of a temporizing ureteric stent rather than undergo definitive surgical intervention at the outset. Female patients were less likely to have a computed tomography (CT) scan of the kidneys, ureters and bladder performed within 24 h of presentation (13% vs 7.3% for men [chi-squared P = 0.01]) and to be given correct analgesia (66% vs 73% for men [chi-squared P = 0.03]). Patients aged 60 years or older were also significantly less likely to be offered nonsteroidal anti-inflammatory drug analgesia appropriately. In total, 87% of patients had their calcium measured within the last 2 years and 73% of patients had evidence of being offered stone prevention diet and fluid advice. CONCLUSIONS: The audit demonstrates that the National Institute of Health and Care Excellence Quality Standards are both measurable and achievable. However, there was considerable variation in the delivery of these standards, including with regard to sex and age, highlighting inequalities for patient care across the UK.

A Prospective Multi-Institutional Evaluation of Iatrogenic Urethral Catheterization Injuries.

OBJECTIVES: To perform a multi-institutional investigation of incidence and outcomes of urethral trauma sustained during attempted catheterization. PATIENTS & METHODS: A prospective, multi-center study was conducted over a designated 3-4 month period, incorporating seven academic hospitals across the UK and Ireland. Cases of urethral trauma arising from attempted catheterization were recorded. Variables included sites of injury, management strategies and short-term clinical outcomes. The catheterization injury rate was calculated based on the estimated total number of catheterizations occurring in each center per month. Anonymised data were collated, evaluated and described. RESULTS: Sixty-six urethral catheterization injuries were identified (7 centers; mean 3.43 months). The mean injury rate was 6.2 ± 3.8 per 1000 catheterizations (3.18-14.42/1000). All injured patients were male, mean age 76.1 ± 13.1 years. Urethral catheterization injuries occurred in multiple hospital/community settings, most commonly Emergency Departments (36%) and medical/surgical wards (30%). Urological intervention was required in 94.7% (54/57), with suprapubic catheterization required in 12.3% (n = 7). More than half of patients (55.56%) were discharged with an urethral catheter, fully or partially attributable to the urethral catheter injury. At least one further healthcare encounter on account of the injury was required for 90% of patients post-discharge. CONCLUSIONS: This is the largest study of its kind and confirms that iatrogenic urethral trauma is a recurring medical error seen universally across institutions, healthcare systems and countries. In addition, urethral catheter injury results in significant patient morbidity with a substantial financial burden to healthcare services. Future innovation to improve the safety of urinary catheterization is warranted.

Radiation-Induced Vascular Disease-A State-of-the-Art Review.

Since the 1990s, there has been a steady increase in the number of cancer survivors to an estimated 17 million in 2019 in the US alone. Radiation therapy today is applied to a variety of malignancies and over 50% of cancer patients. The effects of ionizing radiation on cardiac structure and function, so-called radiation-induced heart disease (RIHD), have been extensively studied. We review the available published data on the mechanisms and manifestations of RIHD, with a focus on vascular disease, as well as proposed strategies for its prevention, screening, diagnosis, and management.

HoLEP for acute and non-neurogenic chronic urinary retention: how effective is it?

PURPOSE: To determine catheter status within 3 months of holmium laser enucleation of the prostate (HoLEP) for acute and non-neurogenic chronic urinary retention (AUR and NNCUR), to compare short-term outcomes of HoLEP for urinary retention (UR) versus lower urinary tract symptoms (LUTS), and to report long-term serum creatinine (SC) after HoLEP for high-pressure chronic urinary retention (HPCUR). METHODS: A prospectively maintained database of the first 500 consecutive HoLEP cases performed under the care of a single surgeon was analysed retrospectively. Urodynamic studies (UDS) did not play a role in the decision making process for those with UR. NNCUR was defined as painless, with post-void residual volume (PVR) greater than 300 ml in men able to void and initial catheter drainage > 1000 ml in men unable to void. RESULTS: 280/500 (56%) were in UR: AUR (195), and NNCUR (85) including 22 with HPCUR. The UR cohort were older with higher enucleated tissue weight [median (IQR); 72 years (66-79 year) and 56 g (29.8-86.3 g)], than the LUTS cohort [70 years (64-75 year) and 38 g (18-67 g)] (p < 0.001). 98.9% with AUR and 98.8% with NNCUR were catheter-free 3 months after HoLEP. There were no significant differences in transfusion rates, hospital stay, or time to first trial without catheter (TWOC) between the LUTS and UR cohorts, nor in international prostate symptom score and quality of life scores, maximum urinary flow rate, post void residual volume or urinary incontinence at 3 months. Patients with NNCUR were less likely to pass their first TWOC (58.8%) than those with AUR (84.6%) or LUTS (87.7%), p < 0.001. None with HPCUR had a clinically significant deterioration in SC at a median of 60 months (IQR 36-82 months). CONCLUSION: HoLEP has 3-month catheter-free rates in excess of 98.5% for AUR and NNCUR in patients not pre-selected by UDS. First TWOC is significantly more likely to fail after HoLEP for NNCUR than AUR or LUTS. HoLEP is a durable treatment for HPCUR and there is no need to monitor renal function to detect recurrence.

Protective cellular immunity generated by cross-presenting recombinant overlapping peptide proteins.

Priming of naive CD8+ and CD4+ T cells by dendritic cells (DCs) requires effective antigen presentation on both MHC class I and II molecules. We have developed a novel technology to use recombinant overlapping peptides (ROP) that stimulate both CD8+ and CD4+ T cell immune responses. The single chain protein of a ROP is made up of overlapping peptides linked by the target sequence (LRMK) for cathepsin S, a protease found in the endosomes of DCs. We designed synthetic genes encoding ROPs derived from ovalbumin (OVA), tuberculosis protein (CFP10-ESAT6), human papilloma virus (HPV) protein (E7) and survivin, a protein commonly over-expressed in tumour cells. An epitope from ROP-OVA was cross-presented and detected by a CD8+ T cell receptor-like antibody (TCR like Ab). Human DCs pulsed with ROP-survivin activated CD8+ T cells. CD4-low PBMCs from HIV and TB co-infected patients recognized ROP-CFP10-ESAT6 compared to a soluble form of the antigen. Immunization of mice with ROP-survivin or ROP-HPV-E7 generated specific cellular immune responses and protected mice from inoculation with melanoma B16 cells expressing survivin or HPV-E7 proteins. Together these data provide evidence to support ROP as a central component of a new platform for therapeutic vaccines and diagnostics.

Percutaneous Coronary Intervention for Coronary Bifurcation Lesions.

Percutaneous coronary intervention (PCI) of lesions at coronary bifurcations poses a technical challenge. Short-term complications, including periprocedural myocardial infarction, and long-term complications such as in-stent restenosis and stent thrombosis, are higher in patients with bifurcation lesions. Techniques for PCI of bifurcation lesions include stenting of the main branch alone, and the use of two or more stents to cover the main and side branches. Two- or three-stent techniques include T-stenting, crush, culotte, simultaneous kissing stents, V-stenting, and Y-stenting. The goal of these techniques is to minimize areas of vessel that are not covered by stent. Dedicated bifurcation stents exist, including stents with apertures that allow standard stents to be placed within the aperture. Simultaneous kissing balloon angioplasty in the two branches should be performed to optimize angiographic results. Many studies exist comparing the different techniques; however, no consensus exists on the preferred method.

A renal colic fast track pathway to improve waiting times and outcomes for patients presenting to the emergency department.

INTRODUCTION: Renal colic is commonly encountered in the emergency department (ED). We validated a fast track renal colic (FTRC) initiative to decrease patient waiting times and streamline patient flow. METHOD: The FTRC pathway was devised according to the National Institute for Health and Care Excellence clinical summary criteria for the management of patients with suspected renal colic. ED triage nurses use the pathway to identify patients with likely renal colic suitable for fast track to analgesia, investigation and management. Investigations, diagnosis and patient demographics were recorded for 1157 consecutive patients coded as renal colic at a single-center ED over 12 months. RESULTS: Three hundred and two patients were suitable for the FTRC pathway (26.1%), while 855 were seen by the ED clinicians prior to onward referral. Also, 83.9% of patients underwent computed tomography scan. In the FTRC group, 57.3% of patients had radiologically confirmed calculi versus 53.8% in the non-FTRC group (p=0.31). Alternative diagnoses among FTRC patients (2.6%) included ovarian pathology (n=1), diverticulitis (n=2) and incidental renal cell carcinoma (n=2), while 26.1% had no identifiable pathology. No immediately life-threatening diagnoses were identified on imaging. Computed tomography scans performed in the non-FTRC group identified two ruptured abdominal aortic aneurysms and alternative diagnoses (2.57%) including ovarian pathology (n=7), cholecystitis (n=2), incidental renal cell carcinoma (n=3) and inflammatory bowel disease (n=1); 31.2% identified no pathology. Time in ED and time to radiologist-reported imaging were lower for the FTRC group versus non-FTRC group (p<0.0001). CONCLUSION: The FTRC pathway is a safe and efficacious method of reducing diagnostic delay and improving patient flow in the ED.

Percutaneous nephrolithotomy access by urologist or interventional radiologist: practice and outcomes in the UK.

OBJECTIVE: To compare outcomes of urologist vs interventional radiologist (IR) access during percutaneous nephrolithotomy (PCNL) in the contemporary UK setting. PATIENTS AND METHODS: Data submitted to the British Association of Urological Surgeons PCNL data registry between 2009 and 2015 were analysed according to whether access was obtained by a urologist or an IR. We compared access success, number and type of tracts, and perceived and actual difficulty of access. Postoperative outcomes, including stone-free rates, lengths of hospital stay and complications, including transfusion rates, were also compared. RESULTS: Overall, percutaneous renal access was undertaken by an IR in 3453 of 5211 procedures (66.3%); this rate appeared stable over the entire study period for all categories of stone complexity and in cases where there was predicted or actual difficulty with access. Only 1% of procedures were abandoned because of failed access and this rate was identical in each group. IRs performed more multiple tract access procedures than urologists (6.8 vs 5.1%; P = 0.02), but had similar rates of supracostal punctures (8.2 vs 9.2%; P = 0.23). IRs used ultrasonograhpy more commonly than urologists to guide access (56.6% vs 21.7%, P < 0.001). There were no significant differences in complication rates, lengths of hospital stay or stone-free rates. CONCLUSIONS: Our findings suggest that favourable PCNL outcomes may be expected where access is obtained by either a urologist or an IR, assuming that they have received the appropriate training and that they are skilled and proficient in the procedure.

Tips and tricks of ureteroscopy: consensus statement. Part II. Advanced ureteroscopy.

Our "tips and tricks" focuses on all aspects of upper tract endourology and we hope these will be of use to all trainees and consultants who perform ureteroscopy. We report an "expert consensus view" from experienced endourological surgeons, on all aspects of advanced ureteroscopic techniques, with a particular focus on avoiding and getting out of trouble while performing ureteroscopy. In this paper we provide a summary of placing ureteric access sheath, flexible ureteroscopy, intra renal stone fragmentation and retrieval, maintaining visual clarity and biopsy of ureteric and pelvicalyceal tumours.

Radiation Toxicity to the Cardiovascular System.

Radiation therapy is an important component of cancer treatment, and today, it is applied to approximately 50% of malignancies, including valvular, myocardial, pericardial, coronary or peripheral vascular disease, and arrhythmias. An increased clinical suspicion and knowledge of those mechanisms is important to initiate appropriate screening for the optimal diagnosis and treatment. As the number of cancer survivors has been steadily increasing over the last decades, cardio-oncology, an evolving subspecialty of cardiology, will soon play a pivotal role in raising awareness of the increased cardiovascular risk and formulate strategies to optimally manage patients in this unique population.

Assessment of Stone Complexity for PCNL: A Systematic Review of the Literature, How Best Can We Record Stone Complexity in PCNL?

INTRODUCTION: This study aims to systematically review the literature reporting tools for scoring stone complexity and the stratification of outcomes by stone complexity. In doing so, we aim to determine whether the evidence favors uniform adoption of any one scoring system. METHODS: PubMed and Embase databases were systematically searched for relevant studies from 2004 to 2014. Reports selected according to predetermined inclusion and exclusion criteria were appraised in terms of methodologic quality and their findings summarized in structured tables. RESULTS: After review, 15 studies were considered suitable for inclusion. Four distinct scoring systems were identified and a further five studies that aimed to validate aspects of those scoring systems. Six studies reported the stratification of outcomes by stone complexity, without specifically defining a scoring system. All studies reported some correlation between stone complexity and stone clearance. Correlation with complications was less clearly established, where investigated. CONCLUSIONS: This review does not allow us to firmly recommend one scoring system over the other. However, the quality of evidence supporting validation of the Guy's Stone Score is marginally superior, according to the criteria applied in this study. Further evaluation of the interobserver reliability of this scoring system is required.

Hospital Volume Does Not Influence the Safety of Percutaneous Nephrolithotomy in England: A Population-Based Cohort Study.

PURPOSE: This study aims to investigate the relationship between hospital case volume and safety-related outcomes after percutaneous nephrolithotomy (PCNL) within the English National Health Service (NHS). PATIENTS AND METHODS: The study used the Hospital Episode Statistics (HES) database, a routine administrative database, recording information on operations, comorbidity, and outcomes for all NHS hospital admissions in England. Records for all patients undergoing an initial PCNL between April 1, 2006 and March 31, 2012 were extracted. NHS trusts were divided into low-, medium-, and high-volume groups, according to the average annual number of PCNLs performed. We used multiple regression analyses to examine the associations between hospital volume and outcomes incorporating risk adjustment for sex, age, comorbidity, and hospital teaching status. Postoperative outcomes included: Emergency readmission, infection, and hemorrhage. Mean length of stay was also measured. RESULTS: There were 7661 index elective PCNL procedures performed in 163 hospital trusts, between April 2006 and March 2012. There were 2459 patients who underwent PCNL in the 116 units performing fewer than 10 PCNL procedures per year; 2643 patients in the 37 units performing 10 to 19 procedures per year; and 2459 patients in the 9 hospitals performing more than 20 procedures per year. For low-, medium-, and high-volume trusts, there was little variation in the rates of emergency readmission (L 9.7%, M 9.3%, H 8.4%), infection (3.0%, 4.2%, 3.8%), or hemorrhage (1.3%, 1.5%, 1.5%), and there was no statistical evidence that volume was associated with adjusted outcomes. Mean length of stay was slightly shorter in the medium- (5.0 days) and high-volume (5.0) groups compared with the low-volume group (5.3). The effect remained statistically significant after adjusted for confounding. CONCLUSION: Hospital volume was not associated with emergency readmission, infection, or hemorrhage. Length of stay appears to be shorter in higher volume units.

Would You Want to Be the Patient? "Live Surgical Broadcast" or "As-Live Unedited Surgical Broadcast".

OBJECTIVE: To evaluate patient safety, educational value, and ethical issues surrounding "Live surgical broadcast" (LSB) and "As-live surgical broadcast" (ALB) using data obtained from urologic delegates attending two recent endourology meetings in the United Kingdom. SUBJECTS AND METHODS: Two hundred twelve delegates at the UK section meeting of the Société Internationale d'Urologie (SIU) were invited to complete an online survey using SurveyMonkey(®) to compare their previous perceptions of LSB and ALB, and to compare their current experience of ALB to previous experience of LSB. One hundred three delegates at the British Association of Urological Surgeons (BAUS) Endourology meeting used live voting keypads to compare their experience of LSB and ALB simultaneously, as well as comparing their current experience of ALB to previous experience of LSB. Responses were recorded using a Likert scale. RESULTS: One hundred sixty-five responses were analyzed from the meetings. Most delegates were in specialist practice as a consultant or trainee (89.1%). LSB had been witnessed more than ALB (87.1% vs 66.6%, p=0.049). Based on previous experiences, the educational value of both formats was felt similar, but delegates felt there were significant patient safety benefits with ALB over LSB. Delegates were significantly less likely to recommend a friend or family, or volunteer themselves to be a patient in an LSB setting. On-the-day comparison of LSB and ALB shows a similar educational value to both formats, but with significantly less concern for the surgeon and patient's outcome with ALB. CONCLUSION: ALB offers similar educational opportunities to delegates when compared with LSB, while appearing to offer significant welfare benefits to both surgeon and patient. Further studies are required to objectively quantify these subjective observations.

Tips and tricks of ureteroscopy: consensus statement Part I. Basic ureteroscopy.

Ureteroscopy is fast becoming the first line treatment option for the majority of urinary tract stones. Ureteroscopy training can be performed in a variety of ways including simulation, hands on ureteroscopy courses and supervised operative experience. We report an "expert consensus view" from experienced endourological surgeons, on all aspects of basic ureteroscopic techniques, with a particular focus on avoiding and getting out of trouble while performing ureteroscopy. In this paper we provide a summary of treatment planning, positioning, cannulation of ureteric orifice, guidewire placement, rigid ureteroscopy and stone fragmentation.

Cardiovascular complications of radiation exposure.

The cardiovascular sequelae of radiation exposure are an important cause of morbidity and mortality following radiation therapy for cancer, as well as after exposure to radiation after atomic bombs or nuclear accidents. In the United States, most of the data on radiation-induced heart disease (RIHD) come from patients treated with radiation therapy for Hodgkin disease and breast cancer. Additionally, people exposed to radiation from the atomic bombs in Hiroshima and Nagasaki, Japan, and the Chernobyl, Ukraine, nuclear accident have an increased risk of cardiovascular disease. The total dose of radiation, as well as the fractionation of the dose, plays an important role in the development of RIHD. All parts of the heart are affected, including the pericardium, vasculature, myocardium, valves, and conduction system. The mechanism of injury is complex, but one major mechanism is injury to endothelium in both the microvasculature and coronary arteries. This likely also contributes to damage and fibrosis within the myocardium. Additionally, various inflammatory and profibrotic cytokines contribute to injury. Diagnosis and treatment are not significantly different from those for conventional cardiovascular disease; however, screening for heart disease and lifelong cardiology follow-up is essential in patients with past radiation exposure.