Dyadic practice for the acquisition of laparoscopic skills (DALS)-A randomized controlled trial.

BACKGROUND: Laparoscopic simulation is integral to surgical education but requires significant resources. We aimed to compare the effectiveness of dyadic practice (DP), involving two individuals working together, to individual practice (IP) for novices acquiring laparoscopic skills and assess their learning experience. METHODS: We conducted a Randomized Controlled Trial comparing DP and IP for novice medical students who completed a laparoscopic simulation workshop. Participants were assessed individually pre-course (test 1), post-course (test 2), and 8-week retention (test 3) using a validated quantitative method. A post-course questionnaire and interview, analyzed with thematic analysis, assessed the learning experience. RESULTS: In total, 31 DP and 35 IP participants completed the study. There was no difference in mean scores between DP and IP groups in all three tests: test 1 (p = 0.55), test 2 (p = 0.26), test 3 (p = 0.35). In trend analysis, the DP group improved post-course (test 1 vs. 2: p = 0.02) and maintained this level at the retention test (2 vs. 3: p = 0.80, 1 vs. 3: p = 0.02). Whilst the IP group also improved post-course (test 1 vs. 2: p < 0.001), this improvement was not retained (2 vs. 3: p = 0.003, 1 vs. 3: p = 0.32). Thematic analysis revealed that DP participants valued peer support, peer feedback and observation time, but also acknowledged the limitations of reduced practical time and issues with teamwork. CONCLUSION: DP is non-inferior to IP for novices learning laparoscopic skills, is well received and may lead to superior long-term skill retention.

A guide to outcome evaluation of simulation-based education programmes in low and middle-income countries.

Evaluation is a vital part of any learning activity and is essential to optimize and improve educational programmes. It should be considered and prioritized prior to the implementation of any learning activity. However, comprehensive programme evaluation is rarely conducted, and there are numerous barriers to high-quality evaluation. This review provides a framework for conducting outcome evaluation of simulation-based education programmes in low and middle-income countries (LMICs). The basis of evaluation, including core ideas of theory, purpose and structure are outlined, followed by an examination of the levels and healthcare applications of the Kirkpatrick model of evaluation. Then, methods of conducting evaluation of simulation-based education in LMICs are discussed through the lens of a successful surgical simulation programme in Myanmar, a lower-middle-income country. The programme involved the evaluation of 11 courses over 4 years in Myanmar and demonstrated evaluation at the highest level of the Kirkpatrick model. Reviewing this programme provides a bridge between evaluation theory and practical implementation. A range of evaluation methods are outlined, including surveys, interviews, and clinical outcome measurement. The importance of a mixed-methods approach, enabling triangulation of quantitative and qualitative analysis, is highlighted, as are methods of analysing data, including statistical and thematic analysis. Finally, issues and challenges of conducting evaluation are considered, as well as strategies to overcome these barriers. Ultimately, this review informs readers about evaluation theory and methods, grounded in a practical application, to enable other educators in low-resource settings to evaluate their own activities.

Evaluation of a novel home-based laparoscopic and core surgical skills programme (Monash Online Surgical Training).

INTRODUCTION: Limitations to surgical education access were exacerbated during the COVID-19 Pandemic. In response, we created a national home-based comprehensive surgical skills course: Monash Online Surgical Training (MOST). Our aim was to evaluate the educational impact of this approach. METHODS: A remote, 6-week course was designed with learning objectives aligned to the national surgical training. Participants received a personal laparoscopic bench trainer, instrument tracking software, live webinars, access to an online theoretical learning platform, and individualised feedback by system-generated or expert surgeons' assessments. Mixed method analysis of instrument tracking metrics, pre- and post-course questionnaires (11 core surgical domains) and participant comments was utilised. Data were analysed using the Mann-Whitney U test, and a p-value of < 0.05 was considered statistically significant. RESULTS: A total of 54 participants with varied levels of experience (1 to > 6 years post-graduate level) completed MOST. All 11 learning-outcome domains demonstrated statistically significant improvement including core laparoscopic skills (1.4/5 vs 2.8/5, p < 0.0001) and handling laparoscopic instruments (1.5/5 vs 2.8/5, p < 0.0001). A total of 3460 tasks were completed reflecting 158.2 h (9492 min) of practice, 394 were submitted for formal feedback. Participants rated the course (mean 8.5/10, SD 1.6), live webinars (mean 8.9/10, SD 1.6) and instrument tracking software (mean 8.6, SD 1.7) highly. Qualitative analysis revealed a paradigm shift including the benefits of a safe learning environment and self-paced, self-directed learning. CONCLUSION: The MOST course demonstrates the successful implementation of a fully remote laparoscopic simulation course which participants found to be an effective tool to acquire core surgical skills.

Newborn and Infant Parasympathetic Evaluation (NIPE™) Monitor for Assessing Pain During Surgery and Interventional Procedures: A Systematic Review.

BACKGROUND: The heart rate variability-derived Newborn Infant Parasympathetic Evaluation (NIPE) monitor has been designed to be an objective, non-invasive tool for the assessment of pain and discomfort in children under 2 years of age. The aim of this systematic review was to evaluate the ability of NIPE to assess pain in neonates and infants during surgical and/or painful procedures. METHODS: A systematic review (2010-2023) was conducted using PRISMA guidelines. Studies containing children above 2-years-old were excluded. The ROBINS-I (Risk of Bias in Non-randomised Studies of Interventions) tool was used to assess the quality of included studies. RESULTS: 9 databases were searched identifying 470 articles, 460 did not meet the inclusion criteria and were excluded; therefore, 10 studies with 548 participants were included. NIPE was used to assess intraoperative and postoperative pain for surgery under general anaesthesia (5 studies), as well as acute and prolonged pain from other interventional procedures (5 studies). For surgery under general anaesthesia: NIPE has shown to detect nociceptive events (e.g., skin incision, intubation), insufficient analgesia intraoperatively and to predict early postoperative pain. For painful interventional procedures: NIPE has shown to detect acute pain with a high sensitivity and negative predictive value. CONCLUSION: NIPE has been used to assess pain in surgery and for various painful procedures. NIPE can detect intraoperative pain and reflect early postoperative pain. NIPE may be useful in evaluating procedural pain, however with heterogenous outcomes, more studies are required to confirm its efficacy. TYPE OF STUDY: Systematic Review. LEVEL OF EVIDENCE: Level II.

Outcome following the surgical management of varicocele in children and adolescents: a systematic review and meta-analysis.

Background: The ideal surgical approach for the management of varicocele in children and adolescents remains controversial. Several techniques are available including artery- or lymphatic-sparing with optical magnification (via open inguinal or sub-inguinal approach), laparoscopic, antegrade and retrograde embolization/sclerotherapy. Objectives: We aimed to appraise the clinical outcomes of these techniques in children and adolescents. Data Sources and Methods: A systematic review was conducted (1997-2023). Meta-analysis or proportional meta-analysis for non-comparative studies (Freeman-Tukey transformation) using the random effects model was conducted. Results are expressed as overall proportion % and 95% confidence interval (CI). Results: We identified 1910 studies; 632 duplicates were removed, 1278 were screened, 203 were reviewed and 56 were included, with 12 reporting on 2 different techniques (total of 68 data sets). Optical magnification via inguinal approach (498 cases): recurrence 2.5% (0.6-5.6), hydrocele 1.6% (0.47-3.4), testicular atrophy 1% (0.3-2.0), complications 1.1% (0.2-2.6); optical magnification via sub-inguinal approach (592 cases): recurrence 2.1% (0.7-4.4), hydrocele 1.26% (0.5-2.3), testicular atrophy 0.5% (0.1-1.3), complications 4% (1.0-8.8). Laparoscopic with mass-ligation/division (1943 cases): recurrence 2.9% (1.5-4.6), hydrocele 11.4% (8.3-14.9); complications 1.5% (0.6-2.9); laparoscopic with lymphatic-sparing (974 cases): recurrence 2.4% (1.5-3.5), hydrocele 1.2% (0.45-3.36), complications 1.2% (0.05-3.9); laparoscopic with artery-sparing (228 cases): recurrence 6.6% (2.3-12.9), hydrocele 6.5% (2.6-12.0). Antegrade embolization/sclerotherapy (403 cases): recurrence 7.6% (5.2-10.4), hydrocele 0.8% (0.17-1.9), technical failure 0.6% (0.1-1.6), complications 4.0% (2.3-6.1); retrograde embolization/sclerotherapy (509 cases): recurrence 6.9% (4.6-9.5), hydrocele 0.8% (0.05-2.5), technical failure 10.2% (4.6-17.6), and complications 4.8% (1.0-11.2). Conclusion: The recurrence rate varies between 2.1% and 7.6% and is higher with the embolization/sclerotherapy techniques. Post-operative hydrocele rate varies between 0.8% and 11.4% and is higher with the laparoscopic mass-ligation/division technique. Testicular atrophy has not been reported with the laparoscopic and embolization/sclerotherapy techniques. The retrograde embolization technique is associated with 10% technical failure (inability to complete the procedure). The laparoscopic lymphatic-sparing technique is characterized by the lowest recurrence rate, incidence of hydrocele and other complications, and no reports of testicular atrophy.

Eye-tracking in surgery: a systematic review.

BACKGROUND: Surgery is constantly evolving with the assistance of rapidly developing novel technology. Eye-tracking devices provide opportunities to monitor the acquisition of surgical skills, gain insight into performance, and enhance surgical practice. The aim of this review was to consolidate the available evidence for the use of eye-tracking in the surgical disciplines. METHODS: A systematic literature review was conducted in accordance with PRISMA guidelines. A search of OVID Medline, EMBASE, Cochrane library, Scopus, and Science Direct was conducted January 2000 until December 2022. Studies involving eye-tracking in surgical training, assessment and technical innovation were included in the review. Non-surgical procedures, animal studies, and studies not involving surgical participants were excluded from the review. RESULTS: The search returned a total of 12 054 articles, 80 of which were included in the final analysis and review. Seventeen studies involved eye-tracking in surgical training, 48 surgical assessment, and 20 were focussing on technical aspects of this technology. Twenty-six different eye-tracking devices were used in the included studies. Metrics such as the number of fixations, duration of fixations, dwell time, and cognitive workload were able to differentiate between novice and expert performance. Eight studies demonstrated the effectiveness of gaze-training for improving surgical skill. CONCLUSION: The current literature shows a broad range of utility for a variety of eye-tracking devices in surgery. There remains a lack of standardization for metric parameters and gaze analysis techniques. Further research is required to validate its use to establish reliability and create uniform practices.

Simulation-based education in urology - an update.

Over the past 30 years surgical training, including urology training, has changed from the Halstedian apprenticeship-based model to a competency-based one. Simulation-based education (SBE) is an effective, competency-based method for acquiring both technical and non-technical surgical skills and has rapidly become an essential component of urological education. This article introduces the key learning theory underpinning surgical education and SBE, discussing the educational concepts of mastery learning, deliberate practice, feedback, fidelity and assessment. These concepts are fundamental aspects of urological education, thus requiring clinical educators to have a detailed understanding of their impact on learning to assist trainees to acquire surgical skills. The article will then address in detail the current and emerging simulation modalities used in urological education, with specific urological examples provided. These modalities are part-task trainers and 3D-printed models for open surgery, laparoscopic bench and virtual reality trainers, robotic surgery simulation, simulated patients and roleplay, scenario-based simulation, hybrid simulation, distributed simulation and digital simulation. This article will particularly focus on recent advancements in several emerging simulation modalities that are being applied in urology training such as operable 3D-printed models, robotic surgery simulation and online simulation. The implementation of simulation into training programmes and our recommendations for the future direction of urological simulation will also be discussed.

Influence of foetal position on the degree of isolated antenatal hydronephrosis.

BACKGROUNDS: The effect of foetal position on the degree of antenatal hydronephrosis (ANH) is unknown. We hypothesized that foetal position is an important contextual factor in ANH, with consequences on prenatal counselling and postnatal management. The current study aimed to investigate the effect of foetal position on the degree of ANH. METHODS: A retrospective study was carried out on consecutive pregnancies with isolated ANH over a 10-year period. Gestational age, foetal presentation (cephalic vs. breech), and degree of ANH (as measured by the AP diameter) were retrieved. Foetuses with other ultrasound findings of the renal tract (renal parenchymal abnormality, ureteric dilatation, or bladder abnormalities) were excluded. Logistic regression analysis was conducted to examine the relationship between the anterior-posterior diameter (APD) and the mode of presentation (cephalic or breech). A P-value of <0.05 was considered significant. RESULTS: Initially 745 scans were identified, with 436 included in the final analysis. Overall, there was an association between foetal presentation and APD regardless of trimester, with cephalic presentations having a greater APD (OR 1.07, 95% CI 1.02-1.11, P = 0.04). CONCLUSION: Cephalic presentations are associated with a significantly greater APD indicating that foetal position should be considered when stratifying ANH. Furthermore, foetal position may be a contributing factor in the mechanism of 'physiological' hydronephrosis.

Effects of a Preoperative Carbohydrate Load on Postoperative Recovery in Children: A Randomised, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Nausea and vomiting are common causes for prolonged postoperative length of hospital stay (LOS) in children. A preoperative carbohydrate load may reduce postoperative nausea and vomiting by improving the perioperative metabolic state. The aim of this study was to determine if a preoperative carbohydrate-containing drink would lead to an improvement in the perioperative metabolic state and consequently reduce the incidence of postoperative nausea, vomiting and LOS in children undergoing day-case surgical procedures. METHOD: Randomised, double-blind, placebo-controlled trial involving children aged 4 to 16-years undergoing day-case surgical procedures. Patients were randomised to receive a carbohydrate-containing drink or a placebo. During the induction of anaesthesia, a venous blood gas, and blood glucose and ketone levels were measured. Postoperatively, the incidence of nausea, vomiting, and LOS were documented. RESULTS: 120 patients were randomised with 119/120 (99.2%) undergoing analysis. Blood glucose level was higher in the carbohydrate group; 5.4 mmol/L [3.3-9.4] versus 4.9 mmol/L [3.6-6.5] (p = 0.01). Blood ketone level was lower in the carbohydrate group; 0.2 mmol/L versus 0.3 mmol/L (p = 0.003). The incidence of nausea and vomiting was not different (p > 0.9 and p = 0.8, respectively). LOS in the carbohydrate group was 26 min shorter than the placebo group (p = 0.02). CONCLUSION: Although a preoperative carbohydrate load may provide a more stable metabolic state at the induction of anaesthesia, we did not find a reduction in postoperative nausea and vomiting. A preoperative carbohydrate load has also minimal effects on the postoperative LOS. TYPE OF STUDY: Randomised clinical trial. LEVEL OF EVIDENCE: I.

The utility of sonographic signs to diagnose simple and complicated appendicitis in children.

BACKGROUND: Acute appendicitis is classified into simple (SA) and complicated (CA). Ultrasound scans (USS) can be useful in clinically equivocal cases, by visualising primary and secondary signs. This study explores the utility of sonographic signs to diagnose and differentiate appendicitis in children. METHODS: Single-centre retrospective cohort study over a 2-year period. Consecutive USS for suspected appendicitis were included; sonographic signs were extracted from standardised institutional worksheets. USS results were compared with pre-defined intraoperative criteria for SA and CA, confirmed with histological analysis. Data are reported as median [interquartile range], percentages (number), area under the curve (AUC), conventional diagnostic formulae and adjusted odds ratios following multiple logistic regression (p < 0.05 considered significant). RESULTS: A total of 934 USS were included, with median age 10.7 [8.0-13.4] years, majority were female (54%). One quarter (n = 226) had SA, 12% (n = 113) had CA, 61% (n = 571) had no appendectomy and 3% (n = 24) had negative appendicectomy. Appendix visualisation rate on USS was 61% (n = 569), with 62% (n = 580) having a conclusive report. Sonographic signs suggesting appendicitis included an appendiceal diameter > 7 mm (AUC 0.92, [95% CI: 0.90-0.94]), an appendicolith (p = 0.003), hyperaemia (p = 0.001), non-compressibility (p = 0.029) and no luminal gas (p = 0.004). Secondary sonographic signs included probe tenderness (p < 0.001) and peri-appendiceal echogenic fat (p < 0.001). Sonographic signs suggesting CA over SA comprised a diameter > 10.1 mm (AUC 0.63, [95% CI: 0.57-0.69]), an appendicolith (p = 0.003) and peri-appendiceal fluid (p = 0.004). CONCLUSION: Presence of specific sonographic signs can aid diagnosis and differentiation of simple and complicated appendicitis in children.

The Newborn Infant Parasympathetic Evaluation (NIPE™) monitor predicts post-operative pain in children undergoing day-procedures: A prospective observational study.

BACKGROUND: Pain assessment is essential for the administration of appropriate analgesia. Currently, clinicians use surrogate methods, such as heart rate or behavioural pain scales, to estimate pain in neonates and infants. The Newborn and Infant Parasympathetic Evaluation (NIPE™) monitor aims to provide an objective numeric value (NIPE index) of pain through a continuous assessment of the patient's parasympathetic activity. The aim of this study was to determine if the intraoperative NIPE index monitoring could predict postoperative pain in neonates and infants. METHODS: This prospective observational pilot study included neonates and infants undergoing elective day-surgical procedures (n = 50). Intraoperatively, NIPE indices at 0 (NIPE0), 10 (NIPE10), 20 (NIPE20), 30 (NIPE30) minutes and at completion of surgery (NIPEe), were recorded; the median NIPE index (NIPEm) was calculated for the entire procedure. Postoperative Face, Legs, Activity, Cry, Consolability (FLACC) scale scores were calculated by the nursing staff blinded to the intraoperative NIPE indices. RESULTS: Linear regression documented an association between the NIPEm and postoperative FLACC score at 0 (r = 0.31, p = 0.03) and 10 min (r = 0.36, p = 0.01). No significant associations were observed for FLACC scores at 20 (r = 0.21, p = 0.2) and 30 min (r = 0.36, p > 0.9). Multiple regression analysis revealed that intraoperative NIPE10, NIPE20, NIPE30 and NIPEe also predicted the FLACC score at 0 min (p = 0.003). CONCLUSION: The intraoperative NIPE index is predictive of pain in the immediate postoperative period. This association was lost at 20 min likely due to nursing intervention to administer analgesia. NIPE monitoring could be useful in facilitating postoperative pain management in infants. LEVEL OF EVIDENCE: II. TYPE OF STUDY: Study of Diagnostic Test.

Assessment of Core Surgical Skills Using a Mixed Reality Headset - The MoTOR Study.

INTRODUCTION: Surgical skill assessment utilises direct observation and feedback by an expert which is potentially subjective, therefore obtaining objective data for hand and eye tracking is essential. Our aim was to evaluate a wearable mixed reality (MR) headset in these domains. METHODS: Participants with differing levels of surgical expertise [novice (N), intermediate (I) & expert (E)] performed 4 simulated surgical tasks; 2 general dexterity (tasks 1&2) and 2 surgical skills (tasks 3&4) wearing the MR headset capturing their hand and eye movements (median & range). Metrics included hand path length and the speed of each index or thumb tip. Gaze data were also captured. Participant demographics, prior expertise and current experience were captured with an electronic survey. Data were analysed with a Shapiro-Wilk test or ANOVA as appropriate. A p-value of < 0.05 was significant. RESULTS: Thirty-six participants were analysed (N = 18, I = 8, E = 8). Tasks 1&2 revealed 2 speed outcomes (left index and left-hand speed) which were significant. For tasks 3&4, various outcomes were significant: path length for left hand (N:45 cm vs. I:31 cm vs. E:27 cm, p = 0.03) and right hand (N:48 cm vs. I:29 cm vs. E:28 cm, p = 0.01) and total time (N:456s vs. I:292 vs. E: 245, p = 0.0002). With left-hand-tying, average path length (N:61 cm vs. I:39 vs. E:36, p = 0.04), average speed (N:11 cm/s vs. I:23 vs. E:24, p = 0.03), and total time (N:156s vs. I:43 vs. E:37, p = 0.003) were significant. The gaze-tracking was not statistically significant. CONCLUSION: The MR headset can be utilised as a valid tool for surgical performance assessment. Outcomes including path length and speed can be valuable metrics captured by the MR Headset during the task completion for detecting surgical proficiency.

Laparoscopic versus open inguinal hernia repair in infants: an initial experience.

BACKGROUND: Inguinal hernia repair is a common operation performed in children. In Australia, open repair (OR) continues to be the preferred method of treatment in infants, despite laparoscopic repair (LR) gaining popularity amongst some international centres. Our aim was to analyse initial outcomes with LR at our paediatric centre. METHODS: We conducted a retrospective review of all patients <1 year of age who received LR or OR between January 2017 and July 2021 at our institution. Data were retrieved from both electronic and scanned medical records. Data were analysed using an unpaired t-test, Mann-Whitney test, Fisher's exact test or simple linear regression. A P-value <0.05 was considered significant. RESULTS: A total of 376 patients were identified: LR was performed in 73 patients, and OR in 303 patients. Bilateral repair was more common amongst patients receiving LR: 56.2% versus 21.5%, P = 0.0001, treating either a symptomatic hernia or an intra-operative contralateral inguinal defect (70%). All LR patients received general anaesthetic, compared to 82.8% of patients in the OR group, P = 0.0001. There were no recurrences following LR and 3 with OR (P = 1.0). The metachronous contralateral inguinal hernia rate following OR was 10% (21/206). There was no significant difference in other complications, including wound infection, haematoma, testicular atrophy, and hydrocele formation. CONCLUSION: In our population OR was performed more often than LR. Operative complication rates were equivalent between OR and LR groups. However, infants that underwent OR were significantly more likely to develop a MCIH.

Tissue adhesive, adhesive tape, and sutures for skin closure of paediatric surgical wounds: prospective randomized clinical trial.

BACKGROUND: Tissue adhesive, adhesive tape, and sutures are used to close surgical incisions. However, it is unclear which produces the best results in children, and whether combination wound closure is better than sutures alone. METHODS: In this parallel randomised controlled trial (ANZCTR: ACTRN12617000158369), children (aged 18 years or less) undergoing elective general surgical or urological procedures were randomized to skin closure with sutures alone, sutures and adhesive tape, or sutures and tissue adhesive. Participants were assessed 2 weeks, 6 weeks, and more than 6 months after operation. Outcomes included wound cosmesis (clinician- and parent-rated) assessed using four validated scales, parental satisfaction, and wound complication rates. RESULTS: 295 patients (333 wounds) were recruited and 277 patients (314 wounds) were included in the analysis. Tissue adhesive wounds had poorer cosmesis at 6 weeks: median 10-point VAS score 7.7 with sutures alone, 7.5 with adhesive tape, and 7.0 with tissue adhesive (P = 0.014). Respective median scores on a 100-point VAS were 80.0, 77.2, and 73.8 (P = 0.010). This difference was not sustained at over 6 months. There was no difference in parent-rated wound cosmesis at 6 weeks (P = 0.690) and more than 6 months (P = 0.167): median score 9.0 with sutures alone, 10.0 with adhesive tape, and 10.0 with tissue adhesive at both stages. Parental satisfaction was similar at all points, with a median score of 5 (very satisfied) for all groups. There was one instance of wound dehiscence in the tissue adhesive group and no wound infections. CONCLUSION: Short-term wound cosmesis was poorer with tissue adhesive although it is unclear whether this difference is sustained in the long-term. There were no differences between techniques for the study outcomes. REGISTRATION NUMBER: ACTRN12617000158369 (ANZCTR) (https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372177&isReview=true).

Factors affecting mechanical complications of central venous access devices in children.

PURPOSE: Factors leading to mechanical complications following insertion of central venous access devices (CVADs) in children are poorly understood. We aimed to quantify the rates and elucidate the mechanisms of these complications. METHODS: Retrospective (2016-2021) review of children (< 18 years old) receiving a CVAD. Data, reported as number of cases (%) and median (IQR), were analysed by Fisher's exact test, chi-squared test and logistic regression analysis. RESULTS: In total, 317 CVADs (245 children) were inserted. Median age was 5.0 (8.9) years, with 116 (47%) females. There were 226 (71%) implantable port devices and 91 (29%) Hickman lines. Overall, 54 (17%) lines had a mechanical complication after 0.4 (0.83) years from insertion: fracture 19 (6%), CVAD migration 14 (4.4%), occlusion 14 (4.4%), port displacement 6 (1.9%), and skin tethering to port device 1 (0.3%). Younger age and lower weight were associated with higher risk of complications (p < 0.0001). Hickman lines had a higher incidence of complications compared to implantable port devices [24/91 (26.3%) vs 30/226 (13.3%); p = 0.008]. CONCLUSION: Mechanical complications occur in 17% of CVADs at a median of < 6 months after insertion. Risk factors include younger age and lower weight. Implantable port devices have a lower complications rate. LEVEL OF EVIDENCE: Level 4: case-series with no comparison group.

Stratifying features for diagnosing hypertrophic stenosis on ultrasound: a diagnostic accuracy study.

BACKGROUND: Our aims were to determine if the diagnostic threshold for diagnosing hypertrophic pyloric stenosis (HPS) on ultrasound scan (USS) should be adjusted based on birth weight (BW), current weight (CW), gestational age (GA), chronological age (CA) or corrected gestational age (CGA). METHODS: All patients who underwent either an USS and pyloromyotomy (Group 1) or an USS for possible HPS (Group 2) at our tertiary centre between July 2013 and June 2019 were identified. Ideal threshold values are identified by measuring Youden's Index (J = sensitivity + specificity - 1; higher is better). Mean maximum Youden's Index for stratified results was compared to that for combined results. RESULTS: Two hundred and eighty-four patients were included (142 patients in both Group 1 and Group 2). Combined maximum Youden's Index for all patients was 0.92 for pyloric canal thickness (PMT) and 0.87 for pyloric canal length (PCL). Mean maximum Youden's Index was higher when patients were stratified by GA, CGA, BW or CW, and equivalent for CA. For pyloric canal length (PCL), mean maximum Youden's Index was lower for all variables when stratified compared to combined. There was no visual trend observed in the diagnostic thresholds between groups. CONCLUSION: Stratifying USS PMT diagnostic thresholds values based on age and weight is statistically more accurate than a single threshold in diagnosing HPS. However, the lack of visual correlation indicates a larger dataset is required to validate these results.