A Novel Cooling Device for Kidney Transplant Surgery.

Background: Prolonged warm ischemia time (WIT) in kidney transplantation is associated with numerous adverse outcomes including delayed graft function and decreased patient and graft survival. Circumventing WIT lies in maintaining renal hypothermia and efficiently performing the vascular anastomosis during this portion of the procedure. Although numerous methods of intra-operative renal cooling have been proposed, most suffer from practical limitations, and none have been widely adopted. Herein we describe a novel device specifically designed to maintain renal hypothermia during kidney transplant surgery.Methods: Aluminum tubing was organized in a serpentine pattern to create a malleable, form-fitting cooling jacket to manipulate renal allografts during transplant surgery. Adult porcine kidneys were used to test the device with 4°C saline as coolant. Kidneys were placed at 24°C; surface and core temperatures were monitored using implanted thermocouples. Anastomosis of porcine kidney vessels to GORE-TEX® vascular grafts in an ex-vivo operative field was performed to assess the functionality of the device.Results: The device maintained surface and core graft temperatures of ≤5°C after 60 minutes of WIT. Furthermore, the device provided hands-free retraction and support for the allograft. We found that ex-vivo anastomosis testing was enhanced by the presence of the cooling jacket.Conclusions: This proof-of-concept study demonstrated that our novel device is a practical tool for renal transplantation and can maintain sufficiently cool graft temperatures to mitigate WIT in an ex-vivo setting. This device is the first of its kind and has the potential to improve kidney transplant outcomes by eliminating WIT during graft implantation.

A novel sorting method for the enrichment of early human spermatocytes from clinical biopsies.

OBJECTIVE: To determine if early spermatocytes can be enriched from a human testis biopsy using fluorescence-activated cell sorting (FACS). DESIGN: Potential surface markers for early spermatocytes were identified using bioinformatics analysis of single-cell RNA-sequenced human testis tissue. Testicular sperm extraction samples from three participants with normal spermatogenesis were digested into single-cell suspensions and cryopreserved. Two to four million cells were obtained from each and sorted by FACS as separate biologic replicates using antibodies for the identified surface markers. A portion from each biopsy remained unsorted to serve as controls. The sorted cells were then characterized for enrichment of early spermatocytes. SETTING: A laboratory study. PATIENTS: Three men with a diagnosis of obstructive azoospermia (age range, 30-40 years). INTERVENTION: None. MAIN OUTCOME MEASURES: Sorted cells were characterized for RNA expression of markers encompassing the stages of spermatogenesis. Sorting markers were validated by their reactivity on human testis formalin-fixed paraffin-embedded tissue. RESULTS: Serine protease 50 (TSP50) and SWI5-dependent homologous recombination repair protein 1 were identified as potential surface proteins specific for early spermatocytes. After FACS sorting, the TSP50-sorted populations accounted for 1.6%-8.9% of total populations and exhibited the greatest average-fold increases in RNA expression for the premeiotic marker stimulated by retinoic acid (STRA8), by 23-fold. Immunohistochemistry showed the staining pattern for TSP50 to be strong in premeiotic undifferentiated embryonic cell transcription factor 1-/doublesex and Mab-3 related transcription factor 1-/STRA8+ spermatogonia as well as SYCP3+/protamine 2- spermatocytes. CONCLUSION: This work shows that TSP50 can be used to enrich early STRA8-expressing spermatocytes from human testicular biopsies, providing a means for targeted single-cell RNA sequencing analysis and in vitro functional interrogation of germ cells during the onset of meiosis. This could enable investigation into details of the regulatory pathways underlying this critical stage of spermatogenesis, previously difficult to enrich from whole tissue samples.

Molecular mechanisms of cellular dysfunction in testes from men with non-obstructive azoospermia.

Male factor infertility affects 50% of infertile couples worldwide; the most severe form, non-obstructive azoospermia (NOA), affects 10-15% of infertile males. Treatment for individuals with NOA is limited to microsurgical sperm extraction paired with in vitro fertilization intracytoplasmic sperm injection. Unfortunately, spermatozoa are only retrieved in ~50% of patients, resulting in live birth rates of 21-46%. Regenerative therapies could provide a solution; however, understanding the cell-type-specific mechanisms of cellular dysfunction is a fundamental necessity to develop precision medicine strategies that could overcome these abnormalities and promote regeneration of spermatogenesis. A number of mechanisms of cellular dysfunction have been elucidated in NOA testicular cells. These mechanisms include abnormalities in both somatic cells and germ cells in NOA testes, such as somatic cell immaturity, aberrant growth factor signalling, increased inflammation, increased apoptosis and abnormal extracellular matrix regulation. Future cell-type-specific investigations in identifying modulators of cellular transcription and translation will be key to understanding upstream dysregulation, and these studies will require development of in vitro models to functionally interrogate spermatogenic niche dysfunction in both somatic and germ cells.

A phase 1 study of an injectable lidocaine paste for spermatic cord block in men with chronic scrotal content pain.

INTRODUCTION: Patients with chronic scrotal content pain (CSCP) lack effective, non-invasive treatment options. We aimed to determine the local and systemic safety, tolerability, pharmacokinetics (PK), and efficacy of a long-lasting local anesthetic in patients with CSCP. METHODS: This was a prospective, single-center, open-label, single-arm, phase 1, dose-escalating trial completed between October 2019 and March 2021. Twelve patients ≥19 years old with unilateral scrotal pain lasting ≥3 months reporting an average maximum pain score over seven days of ≥4 on a 0-10 numerical rating scale (NRS) were included. Patients underwent a test spermatic cord block and those reporting a decrease of ≥2 points were included. The investigational drug, ST-01 (sustained-release lidocaine polymer solution), is a long-acting injection of lidocaine around the spermatic cord. Subjects were provided a NRS dairy and recorded their NRS score until day 28. The Chronic Epididymitis Symptom Index (CESI) was completed on days 0, 7, 14, and 28. All patients underwent an examination and assessment for adverse events (AE) on days 0, 1, 7, 14, and 28. Exploratory statistical hypothesis testing was planned for this study due to its investigative nature. RESULTS: There were no serious adverse events (SAEs) reported. All subjects reported at least one treatment-emergent adverse event (TEAE); 83% of related AEs were injection-site reactions consisting of swelling and bruising. NRS was reduced across all cohorts between baseline and end of study. CONCLUSIONS: This study provides evidence that the novel ST-01 treatment is safe and well-tolerated.

Differentiation of Peritubular Myoid-Like Cells from Human Induced Pluripotent Stem Cells.

Infertility affects 10-15% of couples, with half attributed to male factors. An improved understanding of the cell-type-specific dysfunction contributing to male infertility is needed to improve available therapies; however, human testicular tissues are difficult to obtain for research purposes. To overcome this, researchers have begun to use human induced pluripotent stem cells (hiPSCs) to generate various testis-specific cell types in vitro. Peritubular myoid cells (PTMs) are one such testicular cell type that serves a critical role in the human testis niche but, to date, have not been derived from hiPSCs. This study set forth to generate a molecular-based differentiation method for deriving PTMs from hiPSCs, mirroring in vivo patterning factors. Whole transcriptome profiling and quantitative polymerase chain reaction (qPCR) show that this differentiation method is sufficient to derive cells with PTM-like transcriptomes, including upregulation of hallmark PTM functional genes, secreted growth and matrix factors, smooth muscle, integrins, receptors, and antioxidants. Hierarchical clustering shows that they acquire transcriptomes similar to primary isolated PTMs, and immunostaining shows the acquisition of a smooth muscle phenotype. Overall, these hiPSC-PTMs will allow in vitro study of patient-specific PTM development and function in spermatogenesis and infertility.

Case series: expanding diagnostic markers in postorgasmic illness syndrome.

Introduction: Postorgasmic illness syndrome (POIS) is a rare condition in which individuals develop generalized and flu-like symptoms after ejaculation. Several mechanisms and treatments for this disorder have been proposed but many questions remain. Aims: We sought to present a summary of literature to date and highlight common symptoms, associated features, comorbidities, and laboratory findings in a clinical sample of patients with POIS. Methods: We conducted a retrospective chart review of 6 patients with POIS in our clinic and presented compiled results. Results: We identified newly described non-flu-like presentations, onset of symptoms with high states of arousal without ejaculation, and presence of psychiatric comorbidity in a majority of patients. We did not identify a postorgasm allergic response with bloodwork available. Conclusion: POIS remains a poorly understood condition that likely comprises a number of different clinical entities. Further research on a larger clinical sample is necessary to better characterize POIS and understand its biological and psychological basis.

Human in vitro spermatogenesis as a regenerative therapy - where do we stand?

Spermatogenesis involves precise temporal and spatial gene expression and cell signalling to reach a coordinated balance between self-renewal and differentiation of spermatogonial stem cells through various germ cell states including mitosis, and meiosis I and II, which result in the generation of haploid cells with a unique genetic identity. Subsequently, these round spermatids undergo a series of morphological changes to shed excess cytoplast, develop a midpiece and tail, and undergo DNA repackaging to eventually form millions of spermatozoa. The goal of recreating this process in vitro has been pursued since the 1920s as a tool to treat male factor infertility in patients with azoospermia. Continued advances in reproductive bioengineering led to successful generation of mature, functional sperm in mice and, in the past 3 years, in humans. Multiple approaches to study human in vitro spermatogenesis have been proposed, but technical and ethical obstacles have limited the ability to complete spermiogenesis, and further work is needed to establish a robust culture system for clinical application.

Using clinically derived human tissue to 3-dimensionally bioprint personalized testicular tubules for in vitro culturing: first report.

OBJECTIVE: To study the feasibility and spermatogenic potential of 3-dimensional (3D) bioprinting personalized human testicular cells derived from a patient with nonobstructive azoospermia (NOA). DESIGN: A human testicular biopsy from a single donor with NOA was dissociated into single cells, expanded in vitro, and 3D bioprinted into tubular structures akin to the seminiferous tubule using AGC-10 bioink and an RX1 bioprinter with a CENTRA coaxial microfluidic printhead from Aspect Biosystems. Three-dimensional organoid cultures were used as a nonbioprinted in vitro control. SETTING: Academic medical center. PATIENT(S): A 31-year-old man with NOA with testis biopsy demonstrating Sertoli cell-only syndrome. INTERVENTION(S): Three-dimensional bioprinting and in vitro culturing of patient-derived testis cells. MAIN OUTCOME MEASURE(S): Cellular viability after printing was determined, along with the expression of phenotypic and spermatogenic functional genetic markers after 12 days of in vitro culture. RESULT(S): Testicular cultures were expandable in vitro and generated sufficiently large numbers for 3D bioprinting at 35 million cells per mL of bioink. Viability 24 hours after printing was determined to be 93.4% ± 2.4%. Immunofluorescence staining for the phenotype markers SRY-Box transcription factor 9, insulin-like 3, actin alpha 2 smooth muscle, and synaptonemal complex protein 3 after 12 days was positive, confirming the presence of Sertoli, Leydig, peritubular myoid, and meiotic germ cells. Reverse transcription qualitative polymerase chain reaction analysis showed that after 12 days in spermatogenic media, the bioprints substantially up-regulated spermatogenic gene expression on par with nonbioprinted controls and showed a particularly significant improvement in genes involved in spermatogonial stem cell maintenance: inhibitor of deoxyribonucleic acid binding 4 by 365-fold; fibroblast growth factor 3 by 94,152-fold; stem cell growth factor receptor KIT by twofold; stimulated by retinoic acid 8 by 125-fold; deleted in azoospermia-like by 114-fold; synaptonemal complex protein 3 by sevenfold; zona pellucida binding protein by twofold; transition protein 1 by 2,908-fold; and protamine 2 by 11-fold. CONCLUSION(S): This study demonstrates for the first time the feasibility of 3D bioprinting adult human testicular cells. We show that the bioprinting process is compatible with high testicular cell viability and without loss of the main somatic phenotypes within the testis tissue. We demonstrate an increase in germ cell markers in the 3D bioprinted tubules after 12 days of in vitro culture. This platform may carry future potential for disease modeling and regenerative opportunities in a personalized medicine framework.

Automated rare sperm identification from low-magnification microscopy images of dissociated microsurgical testicular sperm extraction samples using deep learning.

OBJECTIVE: To develop a machine learning algorithm to detect rare human sperm in semen and microsurgical testicular sperm extraction (microTESE) samples using bright-field (BF) microscopy for nonobstructive azoospermia patients. DESIGN: Spermatozoa were collected from fertile men. Testis biopsies were collected from microTESE samples determined to be clinically negative for sperm. A convolutional neural network based on the U-Net architecture was trained using 35,761 BF image patches with fluorescent ground truth image pairs to segment sperm. The algorithm was validated using 7,663 image patches. The algorithm was tested using 7,663 image patches containing abundant sperm, as well as 7,985 image patches containing rare sperm. SETTING: In vitro fertilization center and university laboratories. PATIENT(S): Normospermic and nonobstructive azoospermia patients. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Precision (positive predictive value [PPV]), recall (sensitivity), and F1-score of detected sperm locations. RESULT(S): For sperm-only samples, our algorithm achieved 91% PPV, 95.8% sensitivity, and 93.3% F1-score at ×10 magnification. For dissociated microTESE samples doped with an abundant quantity of sperm, our algorithm achieved 84.0% PPV, 72.7% sensitivity, and 77.9% F1-score. For dissociated microTESE samples doped with rare sperm, our algorithm achieved 84.4% PPV, 86.1% sensitivity, and 85.2% F1-score. CONCLUSION(S): Rare sperm can be detected in patients' testis biopsy samples for potential subsequent use in in vitro fertilization-intracytoplasmic sperm injection. A machine learning algorithm can use BF images at ×10 magnification to accurately detect sperm locations using automated imaging.

The Sexual Goals of Metoidioplasty Patients and Their Attitudes Toward Using PDE5 Inhibitors and Intracavernosal Injections as Erectile Aids.

BACKGROUND: Following metoidioplasty, transmen (TM) experience sexual function challenges including erectile dysfunction, which is typically treated in cisgender men with phosphodiesterase-5 inhibitors (PDE5i) and intracavernosal injections (ICI). AIM: We aim to evaluate sexual function post-metoidioplasty and explore attitudes toward using PDE5i and ICI as potential erectile aids METHODS: All patients who had metoidioplasty completed at the Gender Surgery Program in Vancouver, British Columbia were contacted. Participants completed an electronically accessible self-constructed questionnaire consisting of 39 items on erectile function, orgasm, and penetrative intercourse which also captured Erection Hardness Scores (EHS). Data were analyzed via t-test and 1-way ANOVA. OUTCOMES: Our outcomes were the importance of erectile function, ability to orgasm, penetrative intercourse, and attitudes towards using PDE5i and ICI post-metoidioplasty. RESULTS: Fifteen out of 22 patients completed the survey (median age 32 years). Most had metoidioplasty within the past 2 years. The participants ranked the ability to orgasm and to achieve or maintain erections significantly higher than penetrative intercourse (P <.001, P =.005 respectively). Most participants reported facing challenges with penetrative intercourse (87%) and erectile function (80%). In contrast, a smaller proportion reported challenges with orgasm (33%). With regards to EHS, 83% of participants described their erections as either "larger but not hard," or "hard but not hard enough for penetration." A total of 47% of the participants had previously tried PDE5i, but none had used ICI. Although 87% were willing to use PDE5i, only 40% were willing to try ICI to improve their erections. Patients reported lack of knowledge and understanding among primary care physicians as barriers to accessing treatment for sexual dysfunction. CLINICAL TRANSLATION: The results of this study can facilitate decision making for TM undergoing genital gender-affirmation surgery and provide potential options for improving erectile function post surgery. STRENGTHS & LIMITATIONS: This study represents the first assessment of sexual function and use of erectile aids in post-metoidioplasty patients. The results of this study are limited by the small sample size and enrolment from a single surgical center. CONCLUSION: Metoidioplasty patients surveyed fail to achieve a fully rigid erection without treatment, typically retain the ability to orgasm, and are generally willing to try PDE5i. Khorrami A, Kumar S, Bertin E, et al. The Sexual Goals of Metoidioplasty Patients and Their Attitudes Toward Using PDE5 Inhibitors and Intracavernosal Injections as Erectile Aids. Sex Med 2022;10:100505.

Under-recognized factors affecting penile implant satisfaction in patients.

INTRODUCTION: Surgical management via penile prosthesis is an option for patients who have failed medical management. There is a paucity of literature surrounding factors contributing to patient satisfaction after implant surgery. The objective of this study was to characterize patients' and surgeons' attitudes toward factors affecting satisfaction with this procedure. METHODS: Two patient cohorts were identified and contacted via email: a medical management of erectile dysfunction (ED) cohort and a penile implant patient cohort. A third cohort, Canadian urologists who perform penile implant surgeries, was also contacted. The surveys consisted of 5-7 questions, including a rating question regarding the importance of various penile implant factors. RESULTS: Forty-six ED patients, 45 post-implant patients, and 12 urologists completed the survey. The mean overall satisfaction on a 10-point scale was 6.49 (standard deviation [SD] 2.92). Most (67%) urologists selected patient satisfaction as one of their least favorite aspects of penile implant surgery. Compared to postimplant patients, ED patients reported greater importance in the areas of appearance (p=0.035), soft glans (p=0.040), and concealment of implant (p=0.007). Urologists ranked natural feel (p=0.019) and generating a discrete erection (p=0.022) as less important than patients. CONCLUSIONS: This is the first study that examines which specific variables of penile implant surgery are associated with satisfaction while comparing surgeons' understanding of what patients desire from this surgery. This study identifies several factors deemed important by patients but under-recognized by urologists. This knowledge can aid urologists in optimizing preoperative counselling and improving patient satisfaction.

Sexual rehabilitation recommendations for prostate cancer survivors and their partners from a biopsychosocial Prostate Cancer Supportive Care Program.

PURPOSE: This study aimed to highlight the biopsychosocial recommendations provided to prostate cancer survivors and their partners during sexual rehabilitation. METHODS: Retrospective analysis of a prospectively maintained patient database was conducted for visits between 2013 and 2019. The sexual health rehabilitation action plan (SHRAP) is a standardized 29-item list of biopsychosocial recommendations. The frequency of biopsychosocial recommendations provided to patients via their SHRAPs was assessed. RESULTS: Among 913 patients, across 2671 appointments, nearly 74% of patients underwent radical prostatectomy. Other treatments included combination therapy (surgery, radiation, and/or androgen deprivation therapy (ADT)) (13%), radiation (external beam radiation or brachytherapy) (5%), and active surveillance (2%). Each patient had a median of 2 (SD 2.06) appointments and received a mean of 10.0 (SD 3.9) recommendations at each visit. Educational recommendations (penile rehabilitation, orgasmic guidelines, and climacturia management) were provided in 84% of visits followed by psychosexual recommendations (pleasure-focused, dedicated time, simmering, sexual aids, and sensate focus) in 71% of all appointments. The top recommendations (total n, frequency of recommendation) were penile rehabilitation (2253, 84%), pleasure-focus (1887, 71%), phosphodiesterase inhibitors (1655, 62%), clinical counselor (1603, 60%), vacuum erectile device (1418, 53%) and intracavernosal injections (1383, 52%). CONCLUSIONS: Biopsychosocial programs are evolving to be a key part of prostate cancer survivorship. This study's insight suggests that prostate cancer survivors require education around their sexual consequences and psychosexual counseling alongside proven biomedical strategies for erectile dysfunction. IMPLICATIONS FOR CANCER SURVIVORS: Cancer survivorship programs should integrate educational and psychosocial strategies alongside biological strategies for prostate cancer survivors and their partners.

Use of video education in postoperative patient counselling: A quality improvement initiative.

INTRODUCTION: This quality improvement study examined if a video-based resource could reduce delayed discharges after robotic prostatectomy while maintaining high levels of patient satisfaction. METHODS: From April 2018 to February 2020, all patients undergoing robotic-assisted radical prostatectomy (RARP) were asked to complete an anonymous survey evaluating their perioperative experience. The quality improvement (QI) intervention started in March 2019 with a series of six educational videos being shown to all patients. The videos were used to supplement postoperative instruction. The discharge times of all patients were obtained from The Ottawa Hospital Data Repositories. A run chart analysis was used to detect change in discharge time (outcome measure). Patient satisfaction (balancing measure) was analyzed using Chi-squared analysis and descriptive statistics. RESULTS: A total of 425 robotic prostatectomies (199 pre-intervention, 226 post-intervention) were available. Analysis of the run chart revealed non-random change favoring earlier discharge in the intervention group (p<0.05), with a pre-intervention late discharge rate of 64% and a post-intervention late discharge rate of 55%. A total of 140 surveys (59 pre-intervention, 81 post-intervention) assessing patient satisfaction were completed, corresponding with a response rate of 29.6% and 35.8%, respectively. Median score on a 10-point scale for overall satisfaction was equal between the intervention and non-intervention groups (9 [interquartile range (IQR 8-10) vs. 10 [IQR 8-10], p=0.92). CONCLUSIONS: Patient satisfaction with care and education was high for all patients and was not negatively impacted by this intervention. Video education tools may be one method to help improve the discharge process following RARP.

Y-microdeletions: a review of the genetic basis for this common cause of male infertility.

The human Y-chromosome contains genetic material responsible for normal testis development and spermatogenesis. The long arm (Yq) of the Y-chromosome has been found to be susceptible to self-recombination during spermatogenesis predisposing this area to deletions. The incidence of these deletions is estimated to be 1/4,000 in the general population but has been found to be much higher in infertile men. Currently, Y-microdeletions are the second most commonly identified genetic cause of male infertility after Klinefelter syndrome. This has led to testing for these deletions becoming standard practice in men with azoospermia and severe oligospermia. There are three commonly identified Y-microdeletions in infertile males, termed azoospermia factor (AZF) microdeletions AZFa, AZFb and AZFc. With increased understanding and investigation of this genetic basis for infertility a more comprehensive understanding of these deletions has evolved, with several other deletion subtypes being identified. Understanding the genetic basis and pathology behind these Y-microdeletions is essential for any clinician involved in reproductive medicine. In this review we discuss the genetic basis of Y-microdeletions, the various subtypes of deletions, and current technologies available for testing. Our understanding of this issue is evolving in many areas, and in this review we highlight future testing opportunities that may allow us to stratify men with Y-microdeletion associated infertility more accurately.

Male factor infertility: Initial workup and diagnosis in primary care.

OBJECTIVE: To present a case-based discussion on the workup of male factor infertility and review currently available treatments. SOURCES OF INFORMATION: This discussion is based on the current Canadian Urological Association and American Urological Association guidelines, with reference to landmark papers as appropriate from 2010 onward. All articles were retrieved through PubMed. MAIN MESSAGE: Approximately 15% of Canadian couples experience infertility, making it a commonly encountered condition in the primary care setting. Among couples suffering from infertility, male factors can be identified as the sole cause in 30% of cases and as a contributing issue in 20% of cases. Although many of the treatments described aim to improve a couple's chances of naturally conceiving a child via intercourse, many patients ultimately require medical or surgical intervention to achieve pregnancy. This can be a long, protracted course for patients, with important roles for primary care providers and fertility specialists alike. CONCLUSION: Male fertility assessment and treatment has historically been left in the hands of fertility specialists, creating a bottleneck for patients to receive fertility care. However, with increased understanding of the underlying causes of male factor infertility, the workup and initial management can occur in the primary care setting, helping to streamline care.

Returning to the emergency room: An analysis of emergency encounters following urological outpatient surgery.

INTRODUCTION: Previous reports indicate urological surgeries are associated with high rates of hospital re-admission. This study aims to identify factors associated with emergency room (ER) encounters following urological outpatient surgery. METHODS: All outpatient surgeries performed at The Ottawa Hospital between April 1, 2008, and March 31, 2018 by urology, general surgery, gynecology, and thoracic surgery were identified. All ER encounters within 90 days of surgery were captured. Rates of ER encounters by surgical service and procedure type were determined. Patient and surgical factors associated with ER encounters were identified. Factors included age, sex, marital status, presence of primary care provider, procedure, and American Society of Anesthesiologists (ASA) score. RESULTS: A total of 38 377 outpatient surgeries by the included surgical services were performed during the study period, of which urology performed 16 552 (43.1%). Overall, 5641 (14.7%) ER encounters were identified within 90 days of surgery, including 2681 (47.5%) after urological surgery. On multivariable analysis, higher ASA score IV vs. I was associated with higher risk of ER encounter (relative risk [RR] 1.95, 95% confidence interval (CI) 1.46-2.5) and being married was associated with a lower risk of ER encounter (RR 0.85, 95% CI 0.77-0.93). Urological surgeries with the highest risk of ER encounters, compared to the lowest risk procedure (circumcision), were greenlight laser photo vaporization of the prostate (PVP) (RR 3.2, 95% CI 1.8-5.61), ureteroscopy (RR 3.2, 95% CI 1.9-5.4), and ureteric stent insertion (RR 3.1, 95% CI 1.8-5.5). CONCLUSIONS: ER encounters following outpatient surgery are common. This study identifies risk factors to recognize patients that may benefit from additional support to reduce ER care needs.