Hospital volume-outcome relationships for robot-assisted surgeries: a population-based analysis.

BACKGROUND: Associations between procedure volumes and outcomes can inform minimum volume standards and the regionalization of health services. Robot-assisted surgery continues to expand globally; however, data are limited regarding which hospitals should be using the technology. STUDY DESIGN: Using administrative health data for all residents of Ontario, Canada, this retrospective cohort study included adult patients who underwent a robot-assisted radical prostatectomy (RARP), total robotic hysterectomy (TRH), robot-assisted partial nephrectomy (RAPN), or robotic portal lobectomy using 4 arms (RPL-4) between January 2010 and September 2021. Associations between yearly hospital volumes and 90-day major complications were evaluated using multivariable logistic regression models adjusted for patient characteristics and clustering at the level of the hospital. RESULTS: A total of 10,879 patients were included, with 7567, 1776, 724, and 812 undergoing a RARP, TRH, RAPN, and RPL-4, respectively. Yearly hospital volume was not associated with 90-day complications for any procedure. Doubling of yearly volume was associated with a 17-min decrease in operative time for RARP (95% confidence interval [CI] - 23 to - 10), 8-min decrease for RAPN (95% CI - 14 to - 2), 24-min decrease for RPL-4 (95% CI - 29 to - 19), and no significant change for TRH (- 7 min; 95% CI - 17 to 3). CONCLUSION: The risk of 90-day major complications does not appear to be higher in low volume hospitals; however, they may not be as efficient with operating room utilization. Careful case selection may have contributed to the lack of an observed association between volumes and complications.

Hospital learning curves for robot-assisted surgeries: a population-based analysis.

BACKGROUND: Robot-assisted surgery has been rapidly adopted. It is important to define the learning curve to inform credentialling requirements, training programs, identify fast and slow learners, and protect patients. This study aimed to characterize the hospital learning curve for common robot-assisted procedures. STUDY DESIGN: This cohort study, using administrative health data for Ontario, Canada, included adult patients who underwent a robot-assisted radical prostatectomy (RARP), total robotic hysterectomy (TRH), robot-assisted partial nephrectomy (RAPN), or robotic portal lobectomy using four arms (RPL-4) between 2010 and 2021. The association between cumulative hospital volume of a robot-assisted procedure and major complications was evaluated using multivariable logistic models adjusted for patient characteristics and clustering at the hospital level. RESULTS: A total of 6814 patients were included, with 5230, 543, 465, and 576 patients in the RARP, TRH, RAPN, and RPL-4 cohorts, respectively. There was no association between cumulative hospital volume and major complications. Visual inspection of learning curves demonstrated a transient worsening of outcomes followed by subsequent improvements with experience. Operative time decreased for all procedures with increasing volume and reached plateaus after approximately 300 RARPs, 75 TRHs, and 150 RPL-4s. The odds of a prolonged length of stay decreased with increasing volume for patients undergoing a RARP (OR 0.87; 95% CI 0.82-0.92) or RPL-4 (OR 0.77; 95% CI 0.68-0.87). CONCLUSION: Hospitals may adopt robot-assisted surgery without significantly increasing the risk of major complications for patients early in the learning curve and with an expectation of increasing efficiency.

Preoperative mediastinal staging in early-stage lung cancer: Targeted nodal sampling is not inferior to systematic nodal sampling.

OBJECTIVE: To determine whether targeted sampling (TS), which omits biopsy of triple- normal lymph nodes (LNs) on positron emission tomography, computed tomography, and endobronchial ultrasound (EBUS), is noninferior to systematic sampling (SS) of mediastinal LNs during EBUS for staging of patients with early-stage non-small cell lung cancer (NSCLC). METHODS: Patients who are clinical nodal (cN)0-N1 with suspected NSCLC eligible for EBUS based on positron emission tomography/computed tomography were enrolled in this prospective, multicenter trial. During EBUS, all patients underwent TS and then crossed over to SS, whereby at least 3 mediastinal LN stations (4R, 4L, 7) were routinely sampled. Gold standard of comparison was pathologic results. Based on the previous feasibility trial, a noninferiority margin of 6% was established for difference in missed nodal metastasis (MNM) incidence between TS and SS. The McNemar test on paired proportions was used to determine MNM incidence for each sampling method. Analysis was per-protocol using a level of significance of P < .05. RESULTS: Between November 2020 and April 2022, 91 patients were enrolled at 6 high-volume Canadian tertiary care centers. A total of 256 LNs underwent TS and SS. Incidence of MNM was 0.78% in SS and 2.34% in TS, with an absolute difference of 1.56% (95% confidence interval, -0.003% to 4.1%; P = .13). This falls within the noninferiority margin. A total of 6/256 LNs from 4 patients who were not sampled by TS were found to be malignant when sampled by SS. CONCLUSIONS: In high-volume thoracic endosonography centers, TS is not inferior to SS in nodal staging of early-stage NSCLC. This results in change of clinical management for a minority of patients.

Preconditioning program reduces the incidence of prolonged hospital stay after lung cancer surgery: Results from the Move For Surgery randomized clinical trial.

BACKGROUND: Lung cancer resection is associated with high rates of prolonged hospital stay. It is presumed that preconditioning with aerobic exercise can shorten the postoperative duration of hospital stay, but this has not yet been demonstrated in trials after lung cancer surgery. The aim of this study was to perform a RCT to determine whether Move For Surgery (MFS), a home-based and wearable technology-enhanced preconditioning program before lung cancer surgery, is associated with a lower incidence of prolonged hospital stay when compared to usual preoperative care. METHODS: Patients undergoing lung resection for early-stage non-small cell lung cancer were enrolled before surgery into this blinded, single-site RCT, and randomized to either the MFS or control group in a 1 : 1 ratio. Patients in the MFS group were given a wearable activity tracker, and education about deep breathing exercises, nutrition, sleep hygiene, and smoking cessation. Participants were motivated/encouraged to reach incrementally increasing fitness goals remotely. Patients in the control group received usual preoperative care. The primary outcome was the difference in proportion of patients with hospital stay lasting more than 5 days between the MFS and control groups. RESULTS: Of 117 patients screened, 102 (87.2 per cent) were eligible, enrolled, and randomized (51 per trial arm). The majority (95 of 102, 93.1 per cent) completed the trial. Mean(s.d.) age was 67.2(8.8) years and there were 55 women (58 per cent). Type of surgery and rates of thoracotomy were not different between arms. The proportion of patients with duration of hospital stay over 5 days was 3 of 45 (7 per cent) in the MFS arm compared to 12 of 50 (24 per cent) in the control arm (P = 0.021). CONCLUSION: MFS, a home-based and wearable technology-enhanced preconditioning program before lung cancer surgery, decreased the proportion of patients with a prolonged hospital stay. Registration number: NCT03689634 (http://www.clinicaltrials.gov).

After lung cancer surgery, many patients are admitted to hospital for a prolonged amount of time. It is believed that exercises undertaken before surgery can shorten the stay in hospital, but this has not yet been studied. This study aimed to find out whether Move For Surgery (MFS), a home-based exercise (preconditioning) program using wearable technology before lung cancer surgery, can decrease the number of patients who are admitted to hospital for a prolonged amount of time. Patients with lung cancer were invited to enter this trial 3­4 weeks before surgery. They were randomly put into the MFS or control group. Patients in the MFS group were given a wearable activity tracker, and education about deep breathing exercises, nutrition, sleep hygiene, and quitting smoking. Participants were encouraged to reach increasing fitness goals each week. Patients in the control group underwent usual preoperative care. The difference between the MFS and control groups in the proportion of patients with duration of stay in hospital exceeding 5 days was studied. There were 102 participants in total, 51 in each group. The majority (95 of 102, 93.1 per cent) completed the trial. The average age of participants was 67 years, and 58 per cent were women. Type of surgery and number of open operations were no different between groups. The proportion of patients with duration of stay greater than 5 days was 3 of 45 (7 per cent) in the MFS group compared with 12 of 50 (24 per cent) in the control group. Therefore, MFS before lung cancer surgery was shown to decrease the number of patients admitted to hospital for a prolonged amount of time.

Robotic Lobectomy Is Cost-effective and Provides Comparable Health Utility Scores to Video-assisted Lobectomy: Early Results of the RAVAL Trial.

OBJECTIVE: The aim of this study was to determine if robotic-assisted lobectomy (RPL-4) is cost-effective and offers improved patient-reported health utility for patients with early-stage non-small cell lung cancer when compared with video-assisted thoracic surgery lobectomy (VATS-lobectomy). BACKGROUND: Barriers against the adoption of RPL-4 in publicly funded health care include the paucity of high-quality prospective trials and the perceived high cost of robotic surgery. METHODS: Patients were enrolled in a blinded, multicentered, randomized controlled trial in Canada, the United States, and France, and were randomized 1:1 to either RPL-4 or VATS-lobectomy. EuroQol 5 Dimension 5 Level (EQ-5D-5L) was administered at baseline and postoperative day 1; weeks 3, 7, 12; and months 6 and 12. Direct and indirect costs were tracked using standard methods. Seemingly Unrelated Regression was applied to estimate the cost effect, adjusting for baseline health utility. The incremental cost-effectiveness ratio was generated by 10,000 bootstrap samples with multivariate imputation by chained equations. RESULTS: Of 406 patients screened, 186 were randomized, and 164 analyzed after the final eligibility review (RPL-4: n=81; VATS-lobectomy: n=83). Twelve-month follow-up was completed by 94.51% (155/164) of participants. The median age was 68 (60-74). There were no significant differences in body mass index, comorbidity, pulmonary function, smoking status, baseline health utility, or tumor characteristics between arms. The mean 12-week health utility score was 0.85 (0.10) for RPL-4 and 0.80 (0.19) for VATS-lobectomy ( P =0.02). Significantly more lymph nodes were sampled [10 (8-13) vs 8 (5-10); P =0.003] in the RPL-4 arm. The incremental cost/quality-adjusted life year of RPL-4 was $14,925.62 (95% CI: $6843.69, $23,007.56) at 12 months. CONCLUSION: Early results of the RAVAL trial suggest that RPL-4 is cost-effective and associated with comparable short-term patient-reported health utility scores when compared with VATS-lobectomy.

Clinical Validation of the Canada Lymph Node Score for Endobronchial Ultrasound.

BACKGROUND: The Canada Lymph Node Score (CLNS) uses 4 sonographic criteria to predict the risk of malignancy in lymph nodes during endobronchial ultrasound. The CLNS may play a role in identifying targets for biopsy or rebiopsy during invasive mediastinal staging for lung cancer. However the CLNS has not yet been prospectively validated in routine clinical practice. METHODS: CLNSs for each lymph node biopsied during endobronchial ultrasound were prospectively captured for 1 year (2019). The CLNS and the presence of malignancy in each node were compared. Univariate binary logistic regression was completed for each ultrasonographic feature and multivariate logistic regression model. RESULTS: CLNSs and diagnostic pathology results were available for 367 lymph nodes. Incidence of malignancy increased with higher scores. Scores ≥ 3 were significantly associated with malignancy (specificity, 84.4%; positive likelihood ratio, 4.0). Area under the curve was 0.76, indicating a good ability of the model to predict presence or absence of malignancy. Nodes scoring < 2 and negative on computed tomography and positron emission tomography were malignant in 10.1%. CONCLUSIONS: The CLNS correlates with the presence or absence of malignancy in thoracic lymph nodes and may serve as an adjunct to currently available methods of invasive and noninvasive mediastinal staging. The CLNS may be most helpful in selecting which nondiagnostic lymph nodes require rebiopsy. There is a significant risk of a false-negative result even with a score of 0, and using a combination of low CLNSs and negative conventional radiology to obviate the need for any initial biopsy remains to be studied in prospective trials.

The evolving use of robotic surgery: a population-based analysis.

INTRODUCTION: Robotic surgery has integrated into the healthcare system despite limited evidence demonstrating its clinical benefit. Our objectives were (i) to describe secular trends and (ii) patient- and system-level determinants of the receipt of robotic as compared to open or laparoscopic surgery. METHODS: This population-based retrospective cohort study included adult patients who, between 2009 and 2018 in Ontario, Canada, underwent one of four commonly performed robotic procedures: radical prostatectomy, total hysterectomy, thoracic lobectomy, partial nephrectomy. Patients were categorized based on the surgical approach as robotic, open, or laparoscopic for each procedure. Multivariable regression models were used to estimate the temporal trend in robotic surgery use and associations of patient and system characteristics with the surgical approach. RESULTS: The cohort included 24,741 radical prostatectomy, 75,473 total hysterectomy, 18,252 thoracic lobectomy, and 4608 partial nephrectomy patients, of which 6.21% were robotic. After adjusting for patient and system characteristics, the rate of robotic surgery increased by 24% annually (RR 1.24, 95%CI 1.13-1.35): 13% (RR 1.13, 95%CI 1.11-1.16) for robotic radical prostatectomy, 9% (RR 1.09, 95%CI 1.05-1.13) for robotic total hysterectomy, 26% (RR 1.26, 95%CI 1.06-1.50) for thoracic lobectomy and 26% (RR 1.26, 95%CI 1.13-1.40) for partial nephrectomy. Lower comorbidity burden, earlier disease stage (among cancer cases), and early career surgeons with high case volume at a teaching hospital were consistently associated with the receipt of robotic surgery. CONCLUSION: The use of robotic surgery has increased. The study of the real-world clinical outcomes and associated costs is needed before further expanding use among additional providers and hospitals.

Can a mobile app technology reduce emergency department visits and readmissions after lung resection? A prospective cohort study.

BACKGROUND: Emergency department (ED) visits and readmissions after thoracic surgery are a major health care problem. We hypothesized that the addition of a novel post-discharge mobile app specific to thoracic surgery to an existing home care program would reduce ED visits and readmissions compared to a home care program alone. METHODS: We conducted a prospective cohort study of patients undergoing major lung resection for malignant disease between November 2016 and May 2018. Patients received either home care alone (control group) or home care plus a patient-input mobile app (intervention group). Primary outcomes were 30-day readmission and ED visit rates. Secondary outcomes included reasons for ED visits and readmissions, perioperative complications, 30-day mortality, anxiety (assessed with the Generalized Anxiety Disorder-7 Scale [GAD-7]) and app-related adverse events. We compared outcomes between the 2 groups, analyzing the data on an intention-to-treat basis. RESULTS: Despite the greater number of open surgery and anatomic resections in the intervention cohort, patients in that group were less likely than those in the control group to visit the ED within 30 days of discharge (24.0% v. 38.8%, p = 0.02). Thirty-day readmission rates were similar between the intervention and control groups (10.1% v. 12.2%, p = 0.6). In a subset of patients, there was no difference between the 2 groups in the proportion of patients with a GAD-7 score of 0 (control group 79.8%, intervention group 79.5%, p = NS), which indicated a similar absence of postdischarge anxiety and depression symptoms in the 2 cohorts. CONCLUSION: The addition of a mobile app to a home care program after thoracic surgery was associated with a reduced frequency of ED visits, in spite of the higher proportions of thoracotomies and anatomic resections in the app cohort. More studies are needed to evaluate the full effect of this new, emerging technology.

Robotic thoracic surgery in Canada: Are patients willing to pay out of pocket?

Robotic-assisted thoracoscopic surgery (RTS) is safe and effective, but is associated with high capital and operating costs that are not reimbursed by the Canadian government. Currently, patients have access to RTS only when it is supported by research or philanthropic funds. In a recent study, we assessed the extent of patient-reported satisfaction with RTS, whether patients would have been willing to pay out of pocket for it, and what factors were associated with patients' willingness to pay. Many patients (290 of 411 [70.56%]) stated that they would have paid the additional $2000 to supplement the government health care coverage to have access to RTS. Factors found to be significantly associated with participants' willingness to pay were an annual income of $60 000 or more (p = 0.034), private insurance coverage (p = 0.007), overall experience with RTS rated as 8 or higher out of 10 (p < 0.001), and overall postoperative postdischarge experience rated as satisfying or very satisfying (p = 0.004).

Adverse events following robotic surgery: population-based analysis.

BACKGROUND: Robotic surgery was integrated into some healthcare systems despite there being few well designed, real-world studies on safety or benefit. This study compared the safety of robotic with laparoscopic, thoracoscopic, and open approaches in common robotic procedures. METHODS: This was a population-based, retrospective study of all adults who underwent prostatectomy, hysterectomy, pulmonary lobectomy, or partial nephrectomy in Ontario, Canada, between 2008 and 2018. The primary outcome was 90-day total adverse events using propensity score overlap weights, and secondary outcomes were minor or major morbidity/adverse events. RESULTS: Data on 24 741 prostatectomy, 75 473 hysterectomy, 18 252 pulmonary lobectomy, and 6608 partial nephrectomy operations were included. Relative risks for total adverse events in robotic compared with open surgery were 0.80 (95 per cent c.i. 0.74 to 0.87) for radical prostatectomy, 0.44 (0.37 to 0.52) for hysterectomy, 0.53 (0.44 to 0.65) for pulmonary lobectomy, and 0.72 (0.54 to 0.97) for partial nephrectomy. Relative risks for total adverse events in robotic surgery compared with a laparoscopic/thoracoscopic approach were 0.94 (0.77 to 1.15), 1.00 (0.82 to 1.23), 1.01 (0.84 to 1.21), and 1.23 (0.82 to 1.84) respectively. CONCLUSION: The robotic approach is associated with fewer adverse events than an open approach but similar to a laparoscopic/thoracoscopic approach. The benefit of the robotic approach is related to the minimally-invasive approach rather than the platform itself.

The Effect of Major and Minor Complications After Lung Surgery on Length of Stay and Readmission.

The effect of post-operative adverse events (AEs) on patient outcomes such as length of stay (LOS) and readmissions to hospital is not completely understood. This study examined the severity of AEs from a high-volume thoracic surgery center and its effect on the patient postoperative LOS and readmissions to hospital. This study includes patients who underwent an elective lung resection between September 2018 and January 2020. The AEs were grouped as no AEs, 1 or more minor AEs, and 1 or more major AEs. The effects of the AEs on patient LOS and readmissions were examined using a survival analysis and logistic regression, respectively, while adjusting for the other demographic or clinical variables. Among 488 patients who underwent lung surgery, (Wedge resection [n = 100], Segmentectomy [n = 51], Lobectomy [n = 310], Bilobectomy [n = 10], or Pneumonectomy [n = 17]) for either primary (n = 440) or secondary (n = 48) lung cancers, 179 (36.7%) patients had no AEs, 264 (54.1%) patients had 1 or more minor AEs, and 45 (9.2%) patients had 1 or more major AEs. Overall, the median of LOS was 3 days which varied significantly between AE groups; 2, 4, and 8 days among the no, minor, and major AE groups, respectively. In addition, type of surgery, renal disease (urinary tract infection [UTI], urinary retention, or acute kidney injury), and ASA (American Society of Anesthesiology) score were significant predictors of LOS. Finally, 58 (11.9%) patients were readmitted. Readmission was significantly associated with AE group (P = 0.016). No other variable could significantly predict patient readmission. Overall, postoperative AEs significantly affect the postoperative LOS and readmission rates.

Outcomes of patients discharged home with a chest tube after lung resection: a multicentre cohort study.

BACKGROUND: Prolonged air leaks are increasingly treated in the outpatient setting, with patients discharged with chest tubes in place. We evaluated the incidence and risk factors associated with readmission, empyema development and further interventions in this patient population. METHODS: We undertook a retrospective cohort analysis of all patients from 4 tertiary academic centres (January 2014 to December 2017) who were discharged home with a chest tube after lung resection for a postoperative air leak lasting more than 5 days. We analyzed demographics, patient factors, surgical details, hospital readmission, reintervention, antibiotics at discharge, empyema and death. RESULTS: Overall, 253 of 2794 patients were analyzed (9.0% of all resections), including 30 of 759 from centre 1 (4.0%), 67 of 857 from centre 2 (7.8%), 9 of 247 from centre 3 (3.6%) and 147 of 931 from centre 4 (15.8%) (p < 0.001). Our cohort consisted of 56.5% men, and had a median age of 69 (range 19-88) years. Despite similar initial lengths of stay (p = 0.588), 49 patients (19.4%) were readmitted (21%, 0%, 23% and 11% from centres 1 to 4, respectively, p = 0.029), with 18 (36.7%) developing empyema, 11 (22.4%) requiring surgery and 3 (6.1%) dying. Only chest tube duration was a significant predictor of readmission (p < 0.001) and empyema development (p = 0.003), with a nearly threefold increased odds of developing empyema when the chest tube remained in situ for more than 20 days. CONCLUSION: Discharge with chest tube after lung resection is associated with serious adverse events. Given the high risk of empyema development, removal of chest tubes should be considered, when appropriate, within 20 days of surgery. Our data suggest a potential need for proactive postdischarge outpatient management programs to diminish risk of morbidity and death.

RAVAL trial: Protocol of an international, multi-centered, blinded, randomized controlled trial comparing robotic-assisted versus video-assisted lobectomy for early-stage lung cancer.

BACKGROUND: Retrospective data demonstrates that robotic-assisted thoracoscopic surgery provides many benefits, such as decreased postoperative pain, lower mortality, shorter length of stay, shorter chest tube duration, and reductions in the incidence of common postoperative pulmonary complications, when compared to video-assisted thoracoscopic surgery. Despite the potential benefits of robotic surgery, there are two major barriers against its widespread adoption in thoracic surgery: lack of high-quality prospective data, and the perceived higher cost of it. Therefore, in the face of these barriers, a prospective randomized controlled trial comparing robotic- to video-assisted thoracoscopic surgery is needed. The RAVAL trial is a two-phase, international, multi-centered, blinded, parallel, randomized controlled trial that is comparing robotic- to video-assisted lobectomy for early-stage non-small cell lung cancer that has been enrolling patients since 2016. METHODS: The RAVAL trial will be conducted in two phases: Phase A will enroll 186 early-stage non-small cell lung cancer patients who are candidates for minimally invasive pulmonary lobectomy; while Phase B will continue to recruit until 592 patients are enrolled. After consent, participants will be randomized in a 1:1 ratio to either robotic- or video-assisted lobectomy, and blinded to the type of surgery they are allocated to. Health-related quality of life questionnaires will be administered at baseline, postoperative day 1, weeks 3, 7, 12, months 6, 12, 18, 24, and years 3, 4, 5. The primary objective of the RAVAL trial is to determine the difference in patient-reported health-related quality of life outcomes between the robotic- and video-assisted lobectomy groups at 12 weeks. Secondary objectives include determining the differences in cost-effectiveness, and in the 5-year survival data between the two arms. The results of the primary objective will be reported once Phase A has completed accrual and the 12-month follow-ups are completed. The results of the secondary objectives will be reported once Phase B has completed accrual and the 5-year follow-ups are completed. DISCUSSION: If successfully completed, the RAVAL Trial will have studied patient-reported outcomes, cost-effectiveness, and survival of robotic- versus video-assisted lobectomy in a prospective, randomized, blinded fashion in an international setting. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02617186. Registered 22-September-2015. https://clinicaltrials.gov/ct2/show/NCT02617186.

Routine systematic sampling versus targeted sampling during endobronchial ultrasound: A randomized feasibility trial.

OBJECTIVE: Triple normal lymph nodes, appearing benign on computed tomography, positron emission tomography, and endobronchial ultrasound, have less than a 6% probability of malignancy. We hypothesized that targeted sampling (TS), which omits biopsy of triple normal lymph nodes during endobronchial ultrasound, is not an inferior staging strategy to systematic sampling (SS) of all lymph nodes. METHODS: A prospective randomized feasibility trial was conducted to decide on the progression to a pan-Canadian trial comparing TS with SS. Patients with cN0-N1 non-small cell lung cancer undergoing endobronchial ultrasound were randomized to TS or SS. Lymph nodes in the TS arm crossed over to receive SS. Progression criteria included recruitment rate (70% minimum), procedure length (no significant increase for TS), and incidence of missed nodal metastasis (<6%). Mann-Whitney U test and McNemar's test on paired proportions were used for statistical comparisons. RESULTS: The progression criterion of 70% recruitment rate was achieved early, triggering a planned early stoppage of the trial. Nineteen patients were allocated to each arm. The median procedure length for TS was significantly shorter than SS (3.07 vs 19.07 minutes; P < .001). After crossover analysis, 5.45% (95% confidence interval, 1.87-14.85) of lymph nodes in the TS arm were upstaged from N0 to N2, but this incidence of missed nodal metastasis was below the 6% threshold. During surgical resection, the nodal upstaging incidence from N0 to N2 was 0% for 15 lymph nodes in each arm. CONCLUSIONS: Progression criteria to a pan-Canadian, noninferiority crossover trial comparing TS with SS have been met, and such a trial is warranted.

An Artificial Intelligence Algorithm to Predict Nodal Metastasis in Lung Cancer.

BACKGROUND: Endobronchial ultrasound (EBUS) has features that allow a high accuracy for predicting lymph node (LN) malignancy. However their clinical application remains limited because of high operator dependency. We hypothesized that an artificial intelligence algorithm (NeuralSeg; NeuralSeg Ltd, Hamilton, Ontario, Canada) is capable of accurately identifying and predicting LN malignancy based on EBUS images. METHODS: In the derivation phase EBUS images were segmented twice by an endosonographer and used as controls in 5-fold cross-validation training of NeuralSeg. In the validation phase the algorithm was tested on new images it had not seen before. Logistic regression and receiver operator characteristic curves were used to determine NeuralSeg's capability of discrimination between benign and malignant LNs, using pathologic specimens as the gold standard. RESULTS: Two hundred ninety-eight LNs from 140 patients were used for derivation and 108 LNs from 47 patients for validation. In the derivation cohort NeuralSeg was able to predict malignant LNs with an accuracy of 73.8% (95% confidence interval [CI], 68.4%-78.7%). In the validation cohort NeuralSeg had an accuracy of 72.9% (95% CI, 63.5%-81.0%), specificity of 90.8% (95% CI, 81.9%-96.2%), and negative predictive value of 75.9% (95% CI, 71.5%-79.9%). NeuralSeg showed higher diagnostic discrimination during validation compared with derivation (c-statistic = 0.75 [95% CI, 0.65-0.85] vs 0.63 [95% CI, 0.54-0.72], respectively). CONCLUSIONS: NeuralSeg is able to accurately rule out nodal metastasis and can possibly be used as an adjunct to EBUS when nodal biopsy is not possible or inconclusive. Future work to evaluate the algorithm in a clinical trial is required.

Contemporary trends in the level of evidence in general thoracic surgery clinical research.

OBJECTIVES: The large volume of scientific publications and the increasing emphasis on high-quality evidence for clinical decision-making present daily challenges to all clinicians, including thoracic surgeons. The objective of this study was to evaluate the contemporary trend in the level of evidence (LOE) for thoracic surgery clinical research. METHODS: All clinical research articles published between January 2010 and December 2017 in 3 major general thoracic surgery journals were reviewed. Five authors independently reviewed the abstracts of each publication and assigned a LOE to each of them using the 2011 Oxford Centre for Evidence-Based Medicine classification scheme. Data extracted from eligible abstracts included study type, study size, country of primary author and type of study designs. Three auditing processes were conducted to establish working definitions and the process was validated with a research methodologist and 2 senior thoracic surgeons. Intra-class correlation coefficient was calculated to assess inter-rater agreement. Chi-square test and Spearman correlation analysis were then used to compare the LOE between journals and by year of publication. RESULTS: Of 2028 publications reviewed and scored, 29 (1.4%) were graded level I, 75 (3.7%) were graded level II, 471 (23.2%) were graded level III, 1420 (70.2%) were graded level IV and 33 (1.6%) were graded level V (lowest level). Most publications (94.9%) were of lower-level evidence (III-V). There was an overall increasing trend in the lower LOE (P < 0.001). Inter-rater reliability was substantial with 95.5% (95%, confidence interval: 0.95-0.96) level of agreement between reviewers. CONCLUSIONS: General thoracic surgery literature consists mostly of lower LOE studies. The number of lower levels of evidence is dominating the recent publications, potentially indicating a need to increase the commitment to produce and disseminate higher-level evidence in general thoracic surgery.