Analysis of duration of different stages of surgery in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) patients: comparison between severe versus non-severe AIS.

PURPOSE: Prolonged surgical duration in severe adolescent idiopathic scoliosis (AIS) patients is associated with increased blood loss and perioperative complications. The aim of this study was to compare the duration of each stage of posterior spinal fusion (PSF) in severe AIS (Cobb angle ≥ 90°) with non-severe AIS patients. This analysis will identify the most time-consuming stage of PSF and help surgeons formulate strategies to shorten operative time. METHODS: Retrospective study whereby 90 AIS patients (Lenke type 2, 3, 4, and 6) who underwent PSF from 2019 to 2023 were recruited. Twenty-five severe AIS patients were categorized in Gp1 and 65 non-severe AIS patients in Gp2. Propensity score matching (PSM) with one-to-one with nearest neighbor matching (match tolerance 0.05) was performed. Outcomes measured via operation duration of each stage of surgery, blood loss, number of screws, fusion levels and screw density. RESULTS: Twenty-five patients from each group were matched. Total operative time was significantly higher in Gp1 (168.2 ± 30.8 vs. 133.3 ± 24.0 min, p < 0.001). The lengthiest stage was screw insertion which took 58.5 ± 13.4 min in Gp1 and 44.7 ± 13.7 min in Gp2 (p = 0.001). Screw insertion contributed 39.5% of the overall increased surgical duration in Gp1. Intraoperative blood loss (1022.2 ± 412.5 vs. 714.2 ± 206.7 mL, p = 0.002), number of screws (17.1 ± 1.5 vs. 15.5 ± 1.1, p < 0.001) and fusion level (13.1 ± 0.9 vs. 12.5 ± 1.0, p = 0.026) were significantly higher in Gp1. CONCLUSION: Screw insertion was the most time-consuming stage of PSF and was significantly longer in severe AIS. Adjunct technologies such as CT-guided navigation and robotic-assisted navigation should be considered to reduce screw insertion time in severe AIS.

Predictive modeling of postoperative gastrointestinal dysfunction: the role of serum bilirubin, sodium levels, and surgical duration in gynecological cancer care.

OBJECTIVE: To elucidate the role of preoperative serum bilirubin and sodium levels, along with the duration of surgery, in predicting postoperative gastrointestinal dysfunction (POGD) following gynecological cancer surgery, informing tailored perioperative strategies. METHODS: We conducted a retrospective analysis of 281 patients undergoing gynecological cancer surgery between 2018 and 2023. This analysis focused on preoperative serum bilirubin and sodium levels and intraoperative factors (surgical duration) as potential predictors of POGD. Logistic regression models were utilized for analysis, controlling for relevant confounders. RESULTS: Elevated preoperative serum bilirubin was associated with a reduced risk of POGD (mean level in non-POGD cases: 14.172 ± 4.0701, vs. POGD cases: 9.6429 ± 3.5351; p <  0.001), suggesting a protective role. Lower preoperative sodium levels were identified in the POGD group (136.26 mEq/L [IQR: 135.2-137.63]) compared to the non-POGD group (139.32 mEq/L [IQR: 137.7-140.75]; p <  0.001), highlighting its predictive value. Additionally, longer surgical duration was associated with increased POGD incidence, with POGD cases experiencing surgeries lasting 6.1547 ± 1.9426 hours compared to 4.5959 ± 1.5475 hours in non-POGD cases (p <  0.001). CONCLUSION: Our findings underscore the importance of serum bilirubin, sodium levels, and surgical duration as significant predictors of POGD in patients undergoing gynecological cancer surgery. These indicators should be integrated into a predictive model, aiding clinicians in identifying high-risk patients, allowing for personalized perioperative care adjustments, potentially mitigating POGD risks.

'After-hours' non-elective spine surgery is associated with increased perioperative adverse events in a quaternary center.

PURPOSE: 'After-hours' non-elective spinal surgeries are frequently necessary, and often performed under sub-optimal conditions. This study aimed (1) to compare the characteristics of patients undergoing non-elective spine surgery 'After-hours' as compared to 'In-hours'; and (2) to compare the perioperative adverse events (AEs) between those undergoing non-elective spine surgery 'after-hours' as compared to 'in-hours'. METHODS: In this retrospective study of a prospective non-elective spine surgery cohort performed in a quaternary spine center, surgery was defined as 'in-hours' if performed between 0700 and 1600 h from Monday to Friday or 'after-hours' if more than 50% of the operative time occurred between 1601 and 0659 h, or if performed over the weekend. The association of 'after-hours' surgery with AEs, surgical duration, intraoperative estimated blood loss (IOBL), length of stay and in-hospital mortality was analyzed using stepwise multivariate logistic regression. RESULTS: A total of 1440 patients who underwent non-elective spinal surgery between 2009 and 2013 were included in this study. A total of 664 (46%) procedures were performed 'after-hours'. Surgical duration and IOBL were similar. About 70% of the patients operated 'after-hours' experienced at least one AE compared to 64% for the 'in-hours' group (p = 0.016). 'After-hours' surgery remained an independent predictor of AEs on multivariate analysis [adjusted OR 1.30, 95% confidence interval (CI) 1.02-1.66, p = 0.034]. In-hospital mortality increased twofold in patients operated 'after-hours' (4.4% vs. 2.1%, p = 0.013). This association lost significance on multivariate analysis (adjusted OR 1.99, 95% CI 0.98-4.06, p = 0.056). CONCLUSION: Non-elective spine surgery performed 'after-hours' is independently associated with increased risk of perioperative adverse events, length of stay and possibly, mortality. Research is needed to determine the specific factors contributing to poorer outcomes with 'after-hours' surgery and strategies to minimize this risk. These slides can be retrieved under Electronic Supplementary Material.

Blisters in Ankle Fractures: A Retrospective Cohort Study.

The most frequent postoperative complications after an ankle fracture are usually skin related. We present the results of a retrospective study of 112 patients with ankle fracture who had undergone open reduction and internal fixation from January 2014 to December 2014. The following features were analyzed: patient comorbidities, fracture type, the presence of an open fracture or fracture-dislocation, timing and duration of surgery, preoperative glucose level, and short-term complications (i.e., blisters, wound dehiscence, deep and superficial infections, and reintervention). The mean age of the patients was 50.38 years. Fracture blisters were present in 20.5% of the cases. The operative time was 75.74 ± 25.09 minutes for patients with blisters and 64.48 ± 19.73 minutes for patients without blisters (p = .023). The preoperative blood glucose levels were 122.96 ± 28.46 g/dL in the patients with blisters and 106.70 ± 21.32 g/dL in the patients without blisters (p = .003). No statistically significant differences were observed between the patients who had undergone surgery <24 hours after injury and those who had done so >24 hours after injury. In conclusion, the presence of postoperative blisters in patients with ankle fractures was associated with prolonged surgical procedures and high serum glucose levels.

Implementation and prospective performance evaluation of an intraoperative duration prediction model using high throughput real-time data.

Background: Accurate real-time prediction of intraoperative duration can contribute to improved perioperative outcomes. We implemented a data pipeline for extraction of real-time data from nascent anaesthesia records and silently deployed a predictive machine learning (ML) algorithm. Methods: Clinical variables were retrieved from the electronic health record via a third-party clinical decision support platform and contemporaneously ingested into a previously developed ML model. The model was trained using 3 months data, and performance was subsequently evaluated over 10 months using continuous ranked probability score. Results: The ML model made 6 173 435 predictions on 62 142 procedures. Mean continuous ranked probability score for the ML model was 27.19 (standard error 0.016) min compared with 51.66 (standard error 0.029) min for the bias-corrected scheduled duration. Linear regression did not demonstrate performance drift over the testing period. Conclusions: We implemented and silently deployed a real-time ML algorithm for predicting surgery duration. Prospective evaluation showed that model performance was preserved over a 10-month testing period.

Association between operative duration and adverse outcomes after hip fracture surgery: A NSQIP matched cohort study.

BACKGROUND: Prolonged operative duration is an independent risk factor for surgical complications in numerous subspecialties. However, associations between adverse events and operative duration of hip fracture fixation in older adults have not been well-quantified. This study aims to determine if prolonged operative duration of hip fracture surgery is related to adverse outcomes. We hypothesized that patients with high operative durations experience greater rates of 30-day complications. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was retrospectively reviewed to identify older adults (55 years and above) who underwent hip fracture fixation between 2015-2019. Prolonged operative duration was defined as >75th percentile, and cases were matched using propensity scores based on demographic, surgical, and comorbidity factors. Univariate differences in adverse events (including readmission, reoperation, mortality, and organ-system complications) were analyzed. Multivariable mixed-effects logistic regression analyses were completed for statistically significant events. RESULTS: A total of 8827 case-control pairs were identified for comparison. Rates of superficial surgical site infection (SSI) (p= 0.022), any SSI (p= 0.032), and any complication (p < 0.001) were elevated in those with prolonged surgical duration in univariate analyses. In multivariable models, prolonged operative time was associated with superficial SSI (OR 1.50, p= 0.019), any SSI (OR 1.35; p= 0.029) and any complication (OR 1.58; p < 0.001). In subgroup analyses, all findings persisted for IMN with operative time associated with superficial SSI (OR 1.98, p= 0.012), any SSI (OR 1.71; p= 0.019), and any complication (OR 1.84; p < 0.001). Operative time was associated only with any complication for hemiarthroplasty/internal fixation and sliding hip screw (OR 1.27 and 1.89, respectively; p < 0.001). CONCLUSION: Our study demonstrates that duration of surgery is an independent risk factor for superficial SSI, any SSI, and any complication. Notably, our findings suggest that high operative durations may be most concerning for SSIs in IMN fixation, which is currently the most common choice for hip fracture fixation in the US. However, the rate of any complication is significantly elevated when surgical duration is prolonged, regardless of surgery type.

Feasibility of Predicting Surgical Duration in Endometriosis Using Numerical Multi-Scoring System of Endometriosis (NMS-E).

BACKGROUND: Endometriosis is a multifaceted gynecological condition that poses diagnostic challenges and affects a significant number of women worldwide, leading to pain, infertility, and a reduction in patient quality of life (QoL). Traditional diagnostic methods, such as the revised American Society for Reproductive Medicine (r-ASRM) classification, have limitations, particularly in preoperative settings. The Numerical Multi-Scoring System of Endometriosis (NMS-E) has been proposed to address these shortcomings by providing a comprehensive preoperative diagnostic tool that integrates findings from pelvic examinations and transvaginal ultrasonography. METHODS: This retrospective study aims to validate the effectiveness of the NMS-E in predicting surgical outcomes and correlating with the severity of endometriosis. Data from 111 patients at Nippon Medical School Hospital were analyzed to determine the correlation between NMS-E scores, including E-score-a severity indicator-traditional scoring systems, surgical duration, blood loss, and clinical symptoms. This study also examined the need to refine parameters for deep endometriosis within the NMS-E to enhance its predictive accuracy for disease severity. RESULTS: The mean age of the patient cohort was 35.1 years, with the majority experiencing symptoms such as dysmenorrhea, dyspareunia, and chronic pelvic pain. A statistically significant positive correlation was observed between the NMS-E's E-score and the severity of endometriosis, particularly in predicting surgical duration (Spearman correlation coefficient: 0.724, p < 0.01) and blood loss (coefficient: 0.400, p < 0.01). The NMS-E E-score also correlated strongly with the r-ASRM scores (coefficient: 0.758, p < 0.01), exhibiting a slightly more excellent predictive value for surgical duration than the r-ASRM scores alone. Refinements in the methodology for scoring endometriotic nodules in uterine conditions improved the predictive accuracy for surgical duration (coefficient: 0.752, p < 0.01). CONCLUSIONS: Our findings suggest that the NMS-E represents a valuable preoperative diagnostic tool for endometriosis, effectively correlating with the disease's severity and surgical outcomes. Incorporating the NMS-E into clinical practice could significantly enhance the management of endometriosis by addressing current diagnostic limitations and guiding surgical planning.

Comparing Anesthesia and Surgery Controlled Time for Primary Total Knee and Hip Arthroplasty Between an Academic Medical Center and a Community Hospital: Retrospective Cohort Study.

BACKGROUND: Osteoarthritis is a significant cause of disability, resulting in increased joint replacement surgeries and health care costs. Establishing benchmarks that more accurately predict surgical duration could help to decrease costs, maximize efficiency, and improve patient experience. We compared the anesthesia-controlled time (ACT) and surgery-controlled time (SCT) of primary total knee (TKA) and total hip arthroplasties (THA) between an academic medical center (AMC) and a community hospital (CH) for 2 orthopedic surgeons. OBJECTIVE: This study aims to validate and compare benchmarking times for ACT and SCT in a single patient population at both an AMC and a CH. METHODS: This retrospective 2-center observational cohort study was conducted at the University of Colorado Hospital (AMC) and UCHealth Broomfield Hospital (CH). Cases with current procedural terminology codes for THA and TKA between January 1, 2019, and December 31, 2020, were assessed. Cases with missing data were excluded. The primary outcomes were ACT and SCT. Primary outcomes were tested for association with covariates of interest. The primary covariate of interest was the location of the procedure (CH vs AMC); secondary covariates of interest included the American Society of Anesthesiologists (ASA) classification and anesthetic type. Linear regression models were used to assess the relationships. RESULTS: Two surgeons performed 1256 cases at the AMC and CH. A total of 10 THA cases and 12 TKA cases were excluded due to missing data. After controlling for surgeon, the ACT was greater at the AMC for THA by 3.77 minutes and for TKA by 3.58 minutes (P<.001). SCT was greater at the AMC for THA by 11.14 minutes and for TKA by 14.04 minutes (P<.001). ASA III/IV classification increased ACT for THA by 3.76 minutes (P<.001) and increased SCT for THA by 6.33 minutes after controlling for surgeon and location (P=.008). General anesthesia use was higher at the AMC for both THA (29.2% vs 7.3%) and TKA (23.8% vs 4.2%). No statistically significant association was observed between either ACT or SCT and anesthetic type (neuraxial or general) after adjusting for surgeon and location (all P>.05). CONCLUSIONS: We observed lower ACT and SCT at the CH for both TKA and THA after controlling for the surgeon of record and ASA classification. These findings underscore the efficiency advantages of performing primary joint replacements at the CH, showcasing an average reduction of 16 minutes in SCT and 4 minutes in ACT per case. Overall, establishing more accurate benchmarks to improve the prediction of surgical duration for THA and TKA in different perioperative environments can increase the reliability of surgical duration predictions and optimize scheduling. Future studies with study populations at multiple community hospitals and academic medical centers are needed before extrapolating these findings.

Development and validation of a nomogram for predicting operating time in laparoscopic anterior resection of rectal cancer.

Aims: The goal of this study is to create and verify a nomogram estimate operating time in rectal cancer (RC) patients based on clinicopathological factors and MRI/CT measurements before surgery. Materials and Methods: The nomogram was developed in a cohort of patients who underwent laparoscopic anterior resection (L-AR) for RC. The clinicopathological and pelvis parameters were collected. Risk factors for a long operating time were determined by univariate and multivariate logistic regression analyses, and a nomogram was established with independent risk factors. The performance of the nomogram was evaluated. An independent cohort of consecutive patients served as the validation dataset. Results: The development group recruited 159 RC patients, while 54 patients were enrolled in the validation group. Independent risk factors identified in multivariate analysis were a distance from the anal verge <5 cm (P = 0.024), the transverse diameter of the pelvic inlet (P < 0.001), mesorectal fat area (P = 0.017), and visceral fat area (P < 0.001). Then, a nomogram was built based on these four independent risk factors. The C-indexes of the nomogram in the development and validation group were 0.886 and 0.855, respectively. And values of AUC were the same with C-indexes in both groups. Besides, the calibration plots showed satisfactory consistency between actual observation and nomogram-predicted probabilities of long operating time. Conclusions: A nomogram for predicting the risk of long operating duration in L-AR of RC was developed. And the nomogram displayed a good prediction effect and can be utilized as a tool for evaluating operating time preoperatively.

Surgical procedure prediction using medical ontological information.

BACKGROUND AND OBJECTIVE: Predicting the duration of surgical procedures is an important step in scheduling operating rooms. Many factors have been shown to influence the duration of a procedure, in this research we aim to use medical ontological information to improve the predictions. METHODS: This paper presents two methods for incorporating the medical information about a surgical procedure into the prediction of the duration of the procedure. The first method uses the Systematised Nomenclature of Medicine Clinical Terms to relate different procedures to each other. The second uses simple text fragments. The relationships between types of procedures are included in a regression model for the procedure duration. These methods are applied to data from New Zealand healthcare facilities and the accuracy of the estimations of the durations is compared. In addition a simulation of scheduling the procedures in an operating room is performed. RESULTS: It is shown that both of the methods provide an improvement in the prediction of procedure durations. When compared to a traditional categorical encoding, the ontological information provides an improvement in the continuous ranked probability scores of the prediction of procedure durations from 18.4 min to 17.1 min, and from 25.3 to 21.3 min for types of procedures that are not performed very often. CONCLUSIONS: Different methods for encoding medical ontological information in surgery procedure duration predictions are presented, and show an improvement over traditional models. The improvement in duration prediction is shown to improve the efficiency of scheduling in a simple simulation.

Comparison of navigation systems for total knee arthroplasty: A systematic review and meta-analysis.

Background: Component alignment is a crucial factor affecting the clinical outcome of total knee arthroplasty (TKA). Accelerometer-based navigation (ABN) systems were developed to improve the accuracy of alignment during surgery. This study aimed to compare differences in component alignment, clinical outcomes, and surgical duration when using conventional instrumentation (CONI), ABN, and computer navigation (CN) systems. Methods: A comprehensive literature search was carried out using the Web of Science, Embase, PubMed, and Cochrane databases. Articles that met the eligibility criteria were included in the study. Meta-analyses were performed using the Cochrane Collaboration Review Manager based on Cochrane Review Method. The variables used for the analyses were postoperative clinical outcome (PCO), surgical duration, and component alignment, including the hip-knee-ankle (HKA) angle, coronal femoral angle (CFA), coronal tibial angle (CTA), sagittal femoral angle (SFA), sagittal tibial angle (STA), and the outliers for the mentioned angles. The mean difference (MD) was calculated to determine the difference between the surgical techniques for continuous variables and the odds ratio (OR) was used for the dichotomous outcomes. Results: The meta-analysis of the CONI and ABN system included 18 studies involving 2,070 TKA procedures, while the comparison of the ABN and CN systems included 5 studies involving 478 TKA procedures. The results showed that the ABN system provided more accurate component alignment for HKA, CFA, CTA, and SFA and produced fewer outliers for HKA, CFA, CTA, and STA. However, while the ABN system also required a significantly longer surgical time than the CONI approach, there was no statistical difference in PCO for the two systems. For the ABN and CN systems, there was no statistical difference in all variables except for the ABN system having a significantly shorter surgical duration. Conclusion: There was no significant difference in the accuracy of component alignment between the ABN and CN systems, but the ABN approach had a shorter surgical duration and at lower cost. The ABN system also significantly improved the accuracy of component alignment when compared to the CONI approach, although the surgery was longer. However, there was no significant difference in PCO between the CONI, ABN, and CN systems.

Upper Airway Stimulation in Female Patients: Safety and Efficacy of a Novel Lateral Approach.

OBJECTIVE: To describe a novel lateral approach for hypoglossal nerve stimulator (HNS) implantation in women and provide evidence for its safety and efficacy. STUDY DESIGN: Retrospective case series. SETTING: Single academic medical center. METHODS: We identified patients implanted with HNS by a single surgeon from January 2017 to December 2021. Patient characteristics, postoperative complications, surgical duration, response to therapy, and need for revision surgery were recorded. RESULTS: One hundred four patients were included, including 93 males and 11 females. The lateral approach for HNS implantation involves placing the chest incision for the implantable pulse generator and respiratory sensor lead vertically in the anterior axillary line instead of horizontally in the infraclavicular area. No changes are made to the stimulator lead placement. All female patients were implanted using a lateral approach and all male patients were implanted via the standard anterior approach. Half of the patients were implanted via a 2-incision technique. The median surgical time duration was equivalent in male and female patients (119 [interquartile range (IQR): 105-138] vs 126 [IQR: 115-141], respectively). Revision was required in 2 (18%) females versus 6 (6%) males (p = .17). There were equivalent rates of therapy response as well as postoperative complications. CONCLUSION: A more cosmetic lateral approach is feasible for HNS in female patients and has a similar rate of adverse events and therapy responsiveness. Additional considerations in female patients include the ability to tolerate mammography as well as HNS implantation in the setting of existing breast implants.

Transitioning from the Posterior Approach to the Direct Anterior Approach for Total Hip Arthroplasty.

Purpose: Total hip arthroplasty (THA) using the direct anterior approach (DAA) is known to have a learning curve. The purpose of this study was to review cases where surgery was performed by an arthroplasty surgeon transitioning from the posterior approach (PA) to the DAA. We hypothesized similar complication rates and improvements in surgical duration over time. Materials and Methods: A review of 2,452 consecutive primary THAs was conducted. Surgical duration, length of stay (LOS), surgical complications, decrease in postoperative day (POD) 1 hemoglobin, transfusion rates, POD 0 and POD 1 pain scores, incision length, leg length discrepancy (LLD), and radiographic cup position were recorded. Results: No differences in surgical duration were observed after the first 50 DAA cases. A shorter LOS was observed for the DAA, and statistical difference was appreciated after the first 100 DAA cases. There were no differences in periprosthetic fractures. A higher rate of infections and hip dislocations were observed with the PA. The PA showed an association with higher transfusion rates without significant difference in POD 1 decrease in hemoglobin over the first 100 DAA cases. Similar POD 0 and POD 1 pain scores with a smaller incision were observed for the first 100 DAA cases. The DAA cohort showed less variation in cup inclination, version, and LLD. Conclusion: DAA is safe and non-inferior in terms of reduced LOS, smaller incision, and less variation in cup position. Fifty DAA cases was noted to be the learning curve required before no differences in duration between approaches were observed.

Uterine externalization versus in situ repair of hysterotomy during cesarean delivery: a systematic review, equivalence meta-analysis, and trial sequential analysis.

BACKGROUND: Uterine positioning during hysterotomy repair is controversial, with both in situ and externalized approaches commonly performed. Despite many published trials, clinical equipoise remains. This meta-analysis and trial sequential analysis (TSA) summarizes studies comparing both techniques. METHODS: A systemic search for randomized controlled trials comparing in situ with externalized hysterotomy repair during cesarean delivery was performed. The primary outcomes were estimated blood loss (EBL) and surgical duration. Secondary outcomes were need for blood transfusion, incidence of endometritis, hospital length of stay, intra-operative hypotension, return of bowel function, intra-operative vomiting, intra-operative pain, and need for postoperative analgesia. Cochrane methodology was used to assess risk of bias. Data are presented as mean difference/standardized mean difference or odds ratio/risk difference with 95% confidence intervals (CI). RESULTS: Nineteen studies enrolling 20 739 patients were included. Estimated blood loss and surgical duration were equivalent between methods, with TSA confirming adequate information size for surgical duration but not EBL. In situ repair was associated with faster return of bowel function (MD -0.76 days; 95% CI -1.36 to -0.15; P=0.01) and a reduction in need for breakthrough postoperative analgesia (OR 0.44; 95% CI 0.28 to 0.68; P <0.01). CONCLUSIONS: This analysis revealed equivalence between methods for EBL and surgical duration. While the small reduction in EBL with externalized repair was not clinically or statistically significant, TSA analysis revealed an unmet information size, suggesting a potentially inconclusive result. In situ repair may be associated with less breakthrough postoperative analgesia requirement and faster return of bowel function.

Probabilistic forecasting of surgical case duration using machine learning: model development and validation.

OBJECTIVE: Accurate estimations of surgical case durations can lead to the cost-effective utilization of operating rooms. We developed a novel machine learning approach, using both structured and unstructured features as input, to predict a continuous probability distribution of surgical case durations. MATERIALS AND METHODS: The data set consisted of 53 783 surgical cases performed over 4 years at a tertiary-care pediatric hospital. Features extracted included categorical (American Society of Anesthesiologists [ASA] Physical Status, inpatient status, day of week), continuous (scheduled surgery duration, patient age), and unstructured text (procedure name, surgical diagnosis) variables. A mixture density network (MDN) was trained and compared to multiple tree-based methods and a Bayesian statistical method. A continuous ranked probability score (CRPS), a generalized extension of mean absolute error, was the primary performance measure. Pinball loss (PL) was calculated to assess accuracy at specific quantiles. Performance measures were additionally evaluated on common and rare surgical procedures. Permutation feature importance was measured for the best performing model. RESULTS: MDN had the best performance, with a CRPS of 18.1 minutes, compared to tree-based methods (19.5-22.1 minutes) and the Bayesian method (21.2 minutes). MDN had the best PL at all quantiles, and the best CRPS and PL for both common and rare procedures. Scheduled duration and procedure name were the most important features in the MDN. CONCLUSIONS: Using natural language processing of surgical descriptors, we demonstrated the use of ML approaches to predict the continuous probability distribution of surgical case durations. The more discerning forecast of the ML-based MDN approach affords opportunities for guiding intelligent schedule design and day-of-surgery operational decisions.

Hospitalization length, surgical duration, and blood lost among the approaches for total hip arthroplasty: a Bayesian network meta-analysis.

Despite the numerous studies, there is no consensus concerning the best approach for total hip arthroplasty (THA), and debates are ongoing. The purpose of this study was to perform a Bayesian network meta-analysis (NMA) comparing several approaches for primary THA. The focus was on peri-operative outcomes: surgical duration, total estimated blood loss, and length of the hospitalization. This Bayesian network meta-analysis was conducted according to the PRISMA extension statement for reporting systematic reviews incorporating network meta-analyses of health care interventions. In October 2019, the main databases were accessed. All the clinical trials comparing two or more different approaches for primary THA were assessed. For the methodology quality assessment, the PEDro score was performed. The Software STATA MP was used for the statistical analyses. The NMA was performed through the routine for Bayesian hierarchical random-effects analysis with the inverse variance statistic method for continuous variables. Data from 4843 procedures was analysed. Between patient's demographic, good baseline comparability was found. The comparison total estimated blood loss detected statistically significant inconsistency (P = 0.01). The posterolateral approach reported the lowest value for the surgical duration. The test for overall inconsistency was statistically significant (P = 0.4). The posterolateral approach reported the shortest hospitalization length. The test for overall inconsistency was statistically significant (P = 0.9). The posterolateral approach reported shorter surgical duration and hospitalization length. Concerning the analysis of total estimated blood loss, no significant result was obtained. Data must be considered in the light of the limitations of the present study.

Surgical duration is associated with an increased risk of periprosthetic infection following total knee arthroplasty: A population-based retrospective cohort study.

BACKGROUND: Total knee arthroplasty (TKA) is one the most common elective procedures in the world. Post-operative infection is one of its most devastating complications, often necessitating multiple additional surgeries. We aimed to describe the relationship between surgical duration and risk of deep infection following primary elective TKA. METHODS: In this cohort study we analyses primary TKAs done between 2009 and 2016 in Ontario, Canada. We utilized restricted cubic splines to identify a threshold of surgical duration that was associated with an increased risk for infection requiring surgery. Patients with a 'short' duration of surgery were matched to those with a 'long' duration on patient age (±3 years), patient sex, severe obesity (BMI > 40), the primary surgeon, the hospital and the type of anesthetic. FINDINGS: In 92,343 primary TKAs, the median surgical duration was 106 min. We identified a cut-point of 100 min that was associated with an increased risk for infection. Subsequently, 17,815 TKA recipients with a 'long' procedure length were matched to those with a 'short' procedure length. 'Long' procedures had a higher rate of deep infection (1.1% versus 0.6%, p < 0.0001). This was equal to a relative risk of 1.81 (p < 0.0001). INTERPRETATION: In a cohort of TKA recipients, we found that procedure lengths longer than 100 min were associated with a significantly increased risk of deep infection requiring surgery. This time threshold serves a useful time-point to identify patients that require closer surveillance.

Surgical duration and risk of Urinary Tract Infection: An analysis of 1,452,369 patients using the National Surgical Quality Improvement Program (NSQIP).

INTRODUCTION: While the relationship between surgical duration and post-operative morbidity has been well-studied in specific procedures for specific complications, there is a paucity of literature that addresses whether longer surgeries increase the risk of Urinary Tract Infection (UTI). We have performed the first study to elucidate the relationship between increasing surgical duration and UTI events across surgical specialties via the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. METHODS: Patients, who received general anesthesia, were stratified into quintiles by a calculated z-score for their anesthesia time based on the standard deviation and mean of their respective current procedural terminology (CPT) code. Z-score analysis standardized interprocedural differences in anesthesia time. Multivariate regression analysis was employed to evaluate the independent association of anesthesia time with risk of UTI. Multiple sub-analyses were performed to evaluate the robustness of our results. RESULTS: 22,305 patients (1.5%) experienced a UTI. Compared to the mean procedural duration as represented by the 3rd quintile, procedures of longer duration were independently associated with increased risk of UTI (OR, 1.156 (95% CI 1.104-1.21); OR, 1.758 (95% CI 1.682-1.838)) while procedures of shorter duration were associated with reduced risk (OR, .928 (95% CI .873-.987); OR, .955 (95% CI .906-1.007)). CONCLUSIONS: Our findings suggest that increasing surgical duration may independently worsen the risk of post-operative UTI pan-surgically. We hope that our results will help guide decision making regarding the safety of combination procedures as well as improve pre-operative risk stratification.