M. Rahouma

Unmeasured Confounders in Observational Studies Comparing Bilateral Versus Single Internal Thoracic Artery for Coronary Artery Bypass Grafting: A Meta‐Analysis

Background Observational studies suggest a survival advantage with bilateral single internal thoracic artery (BITA) versus single internal thoracic artery grafting for coronary surgery, whereas this conclusion is not supported by randomized trials. We hypothesized that this inconsistency is attributed to unmeasured confounders intrinsic to observational studies. To test our hypothesis, we performed a meta‐analysis of the observational literature comparing BITA and single internal thoracic artery, deriving incident rate ratio for mortality at end of follow‐up and at 1 year. We postulated that BITA would not affect 1‐year survival based on the natural history of coronary artery bypass occlusion, so that a difference between groups at 1 year could not be attributed to the intervention. Methods and Results We searched MEDLINE and Pubmed to identify all observational studies comparing the outcome of BITA versus single internal thoracic artery. One‐year and long‐term mortality for BITA and single internal thoracic artery were compared in the propensity‐score–matched (PSM) series, that is, the form of observational evidence less prone to confounders. Thirty‐eight observational studies (174 205 total patients) were selected for final comparison. In the 12 propensity‐score–matched series (34 019 patients), the mortality reduction for BITA was similar at 1 year and at the end of follow‐up (incident rate ratio, 0.70; 95% confidence interval, 0.60–0.82 versus 0.77; 95% confidence interval, 0.70–0.85; P for subgroup difference=0.43). Conclusions Unmeasured confounders, rather than biological superiority, may explain the survival advantage of BITA in observational series.

Endoscopic versus open radial artery harvesting: A meta‐analysis of randomized controlled and propensity matched studies

We sought to investigate the impact of radial artery harvesting techniques on clinical outcomes using a meta‐analytic approach limited to randomized controlled trials and propensity‐matched studies for clinical outcomes, in which graft patency was analyzed.

Cerebrospinal-fluid drain-related complications in patients undergoing open and endovascular repairs of thoracic and thoraco-abdominal aortic pathologies: a systematic review and meta-analysis

Background: Cerebrospinal‐fluid (CSF) drainage is recommended by current guidelines for spinal protection during open and endovascular repairs of thoracic and thoraco‐abdominal aortic aneurysms. In the published literature, great variability exists in the rate of CSF‐related complications and morbidity. Herein, we perform a systematic review and meta‐analysis on the incidence of CSF drainage‐related complications, and compare the complication rates between open and endovascular repairs. Methods: The systematic review was conducted according to the Meta‐Analysis of Observational Studies in Epidemiology guidelines. Thirty‐four studies (4714 patients) were included in the quantitative analysis. The CSF drainage‐related complications were categorised as mild, moderate, and severe. Pooled event rates for each complication category were estimated using a random‐effect model. Random‐effect uni‐ and multivariable meta‐regression analyses were used to assess the effect of aortic‐repair approach (open vs endovascular) and the CSF drainage criteria on CSF drainage‐related complications. Results: The pooled event rates were 6.5% [95% confidence interval (CI): 4.3–9.8%] for overall complications, 2% (95% CI: 1.1–3.4%) for minor complications, 3.7% (95% CI: 2.5–5.6%) for moderate complications, and 2.5% (95% CI: 1.6–3.8%) for severe complications. The drainage‐related‐mortality pooled event rate was 0.9% (95% CI: 0.6–1.4%). The uni‐ and multivariable meta‐regression analyses showed no difference in complication rates between the open and endovascular approaches, or between the different CSF drainage protocols. Conclusion: The complication rate for CSF drainage is not negligible. Our results help define a more accurate risk–benefit ratio for CSF drain placement at the time of repair of thoracic and thoraco‐abdominal aneurysms.

PS01.45: Intraoperative Blood Loss is an Independent Predictor of Poor Disease Free Survival for Patients Undergoing VATS Lobectomy for Lung Cancer: Topic: Surgery

Conversion to a thoracotomy was encountered in 66 patients(6.5%). 3 patients (0.3%) had 30-days postoperative mortality. On MVA, only advanced pathological stage[(pStage II, HR: 1.69, 95%CI: 1.15-2.48),(pStage III, HR: 2.94, 95%CI: 2.09-4.14)], grade 2/3 tumors(HR: 1.53, 95% CI: 1.092.16),and longer LOS(HR: 1.05, 95% CI: 1.01-1.09) independently predicted poor DFS. A subgroup analyses on 150 patients(14.9%)80 years old or older(octogenarians),showed comparable complications rate with their younger counterparts(<80 years old) (Clavien Dindo 3, 22.7% vs 17.2%, p1⁄40.110), despite having significantly higher Charlson comorbidity index(CCI>1; 46.7% vs 34.9%, p1⁄40.006). Also, there were no differences between patients older and young than 80 years old regarding probability of freedom from recurrence(p1⁄40.457)or cancer specific survival(p1⁄40.305). Conclusion: The current study reports a large number of lobectomies performed using VATS approach in a high volume academic center. These data came in accordance with previous reports affirming the feasibility, safety,and improved perioperative outcomes associated with this approach, even in the frail octogenarians.

Totally endoscopic coronary artery bypass surgery: A meta-analysis of the current evidence

BACKGROUND Totally endoscopic coronary artery bypass (TECAB) has emerged as an alternative to other minimally invasive techniques. However, limited TECAB results are available to date. The purpose of this systematic review is to examine the existing literature to give an objective estimate of the outcomes of TECAB using a meta-analytical approach. METHODS A comprehensive online review was performed in Ovid MEDLINE®, Ovid EMBASE and The Cochrane Library from 2000 to July 2017. Eligible studies included single arm TECAB studies as well as comparative studies (TECAB vs minimally invasive direct coronary artery bypass (MIDCAB)). Pooled event rates and odds ratios (ORs) for operative mortality, perioperative myocardial infarction (MI), perioperative stroke, graft patency and repeat revascularization were estimated. Single arm and pairwise comparisons were performed. RESULTS Seventeen single arm TECAB articles (3721 patients, weighted mean follow-up 3.3years) were included. The pooled event rate was 0.80% (95%CI: 0.60-1.2%) for operative mortality, 2.28% (95%CI: 1.7-3%) for perioperative MI, 1.50% (95%CI: 1.1-2.0%) for perioperative stroke, 2.99% (95%CI: 1.6-5.4%) for repeat revascularization and 94.8% (95%CI: 89.3-97.5%) for early graft patency (weighted mean follow-up 10.1months). On pairwise meta-analysis 376 patients (263 TECAB and 113 MIDCAB) were included. No difference in operative mortality (OR=0.25, 95%CI: 0.02-2.83), perioperative MI (OR=3.09, 95%CI: 0.37-26.12) or perioperative stroke (OR=1.33, 95%CI: 0.17-10.26) was found between the two techniques. CONCLUSIONS TECAB has an acceptably low operative risk and a good early patency rate. The incidence of perioperative MI requires further investigation. The dearth of data comparing TECAB to open approaches compels the need for future comparative trials.

New-generation stents compared with coronary bypass surgery for unprotected left main disease: A word of caution

Background: With the advent of bare metal stents and drug‐eluting stents, percutaneous coronary intervention has emerged as an alternative to coronary artery bypass grafting surgery for unprotected left main disease. However, whether the evolution of stents technology has translated into better results after percutaneous coronary intervention remains unclear. We aimed to compare coronary artery bypass grafting with stents of different generations for left main disease by performing a Bayesian network meta‐analysis of available randomized controlled trials. Methods: All randomized controlled trials with at least 1 arm randomized to percutaneous coronary intervention with stents or coronary artery bypass grafting for left main disease were included. Bare metal stents and drug‐eluting stents of first‐ and second‐generation were compared with coronary artery bypass grafting. Poisson methods and Bayesian framework were used to compute the head‐to‐head incidence rate ratio and 95% credible intervals. Primary end points were the composite of death/myocardial infarction/stroke and repeat revascularization. Results: Nine randomized controlled trials were included in the final analysis. Six trials compared percutaneous coronary intervention with coronary artery bypass grafting (n = 4654), and 3 trials compared different types of stents (n = 1360). Follow‐up ranged from 6 months to 5 years. Second‐generation drug‐eluting stents (incidence rate ratio, 1.3; 95% credible interval, 1.1–1.6), but not bare metal stents (incidence rate ratio, 0.63; 95% credible interval, 0.27–1.4), and first‐generation drug‐eluting stents (incidence rate ratio, 0.85; 95% credible interval, 0.65–1.1) were associated with a significantly increased risk of death/myocardial infarction/stroke when compared with coronary artery bypass grafting. When compared with coronary artery bypass grafting, the highest risk of repeat revascularization was observed for bare metal stents (hazard ratio, 5.1; 95% confidence interval, 2.1–14), whereas first‐generation drug‐eluting stents (incidence rate ratio, 1.8; 95% confidence interval, 1.4–2.4) and second‐generation drug‐eluting stents (incidence rate ratio, 1.8; 95% confidence interval, 1.4–2.4) were comparable. Conclusions: The introduction of new‐generation drug‐eluting stents did not translate into better outcomes for percutaneous coronary intervention when compared with coronary artery bypass grafting.

PS01.46: Robotic Thymectomy: Early Stage Thymoma and Non-Tumor Benign Lesions has Comparable Perioperative Outcomes: Topic: Surgery

Conversion to a thoracotomy was encountered in 66 patients(6.5%). 3 patients (0.3%) had 30-days postoperative mortality. On MVA, only advanced pathological stage[(pStage II, HR: 1.69, 95%CI: 1.15-2.48),(pStage III, HR: 2.94, 95%CI: 2.09-4.14)], grade 2/3 tumors(HR: 1.53, 95% CI: 1.092.16),and longer LOS(HR: 1.05, 95% CI: 1.01-1.09) independently predicted poor DFS. A subgroup analyses on 150 patients(14.9%)80 years old or older(octogenarians),showed comparable complications rate with their younger counterparts(<80 years old) (Clavien Dindo 3, 22.7% vs 17.2%, p1⁄40.110), despite having significantly higher Charlson comorbidity index(CCI>1; 46.7% vs 34.9%, p1⁄40.006). Also, there were no differences between patients older and young than 80 years old regarding probability of freedom from recurrence(p1⁄40.457)or cancer specific survival(p1⁄40.305). Conclusion: The current study reports a large number of lobectomies performed using VATS approach in a high volume academic center. These data came in accordance with previous reports affirming the feasibility, safety,and improved perioperative outcomes associated with this approach, even in the frail octogenarians.

Use Rate and Outcome in Bilateral Internal Thoracic Artery Grafting: Insights From a Systematic Review and Meta‐Analysis

Background This meta‐analysis was designed to assess whether center experience affects the short‐ and long‐term results and the relative benefits of bilateral internal thoracic artery grafting (BITA) for coronary artery bypass grafting. Methods and Results MEDLINE and EMBASE were searched to identify all articles reporting the outcome of BITA in patients undergoing coronary artery bypass grafting. The BITA center experience was gauged according to the percentage use of BITA in the institutional overall coronary artery bypass grafting population (%BITA). The primary outcome was long‐term all‐cause mortality. Secondary outcomes were operative mortality, perioperative myocardial infarction, perioperative stroke, deep sternal wound infections (DSWIs), and major postoperative adverse event. The rates of the primary and secondary outcomes were calculated after adjusting for %BITA. Primary and secondary outcomes were also compared between the BITA and the single internal thoracic artery arms in the adjusted studies. Meta‐regression was used to evaluate the effect of %BITA on the primary and secondary outcomes. Thirty‐four studies (27 894 patients undergoing BITA) were included. In the pooled analysis, the incidence rate for long‐term mortality was 2.83% (95% confidence interval, 2.21%–3.61%). %BITA was significantly and inversely associated with long‐term mortality and the rate of DSWI. In the pairwise comparison, %BITA was significantly and inversely associated with the risk of long‐term mortality and DSWI in the group undergoing BITA. Conclusions BITA series with higher %BITA report significantly lower long‐term mortality and DSWI rate as well as higher long‐term survival advantage and lower relative risk of DSWI in their BITA cohort. These findings suggest that a specific volume‐outcome relationship exists for BITA grafting.

Meta-Analysis Comparing Outcomes of Drug Eluting Stents Versus Single and Multiarterial Coronary Artery Bypass Grafting

Relative benefits of coronary artery bypass (CABG) using single and multiple arterial grafting (SAG, MAG) and drug eluting stent (DES) in multivessel coronary disease remain uncertain. We compared SAG, MAG, and DES in a pairwise and network meta-analysis. Randomized trials and adjusted observational studies comparing CABG versus DES were included (primary end point: long-term mortality; secondary end points: operative mortality, perioperative stroke, and follow-up repeated revascularization [RR]). Studies with ≥1.7 arterial grafts and/or patient were classified as MAG. Bayesian network meta-analyses and random-model pairwise meta-analyses were performed. A total of 53,239 patients (8 randomized, 17 observational studies) were included (26,306 DES; 26,933 CABG). In pairwise comparison (mean follow-up: 5.42 years), CABG (MAG + SAG) was associated with lower long-term mortality (incident rate ratio [IRR] 0.77, 95% confidence interval [CI] 0.66 to 0.90), lower RR (IRR 0.37, 95% CI 0.27 to 0.51), increased perioperative stroke (odds ratio [OR] 3.18, 95% CI 1.70 to 5.97), and similar operative mortality (OR 1.04, 95% CI 0.64 to 1.70) compared with DES. There was a nonsignificant trend toward lower long-term mortality for studies with higher mean number of arterial grafts. In network meta-analyses, compared with DES, MAG was associated with lower long-term mortality (IRR 0.72, 95% credible interval [CrI] 0.57 to 0.92) and late RR (IRR 0.32, 95% CrI 0.21 to 0.49), SAG was associated with lower long-term mortality and RR (IRR 0.80, 95% CrI 0.66 to 0.97 and IRR 0.42, 95% CrI 0.29 to 0.61, respectively). In conclusion, CABG was associated with reduced 5-year mortality and need for RR compared with DES. MAG was ranked as the best treatment for the primary and all secondary outcomes.

ORAL02.04: Predictors of Adverse Perioperative Outcome Following Lobectomy: A Population Based Analysis: Topic: Surgery

consisted of a median dose of 12.5 Gy/5 F guided by standard dose constraints of normal organs at risk. Results: A total of 35 patients were available for the study. Patient demographics comprised median age 66 years (47-84) and gender ratio 22 men and 13 women. Tumor extent by AJCC included stages IIB (n1⁄45), IIIA (n1⁄412), IIIB (n1⁄417) and IV (n1⁄41) with an oligo metastasis. Tumor histology included squamous cell carcinoma (n1⁄415), adenocarcinoma (n1⁄418), mixed adenosquamous cell carcinoma (n1⁄41) and nonesmall cell carcinoma (n1⁄41). According to the cutoff guideline by visual score, 13 and 22 patients were classified as CMR and IMR respectively. There were no grade 3 toxicities among patients who received boost RT. With a minimum follow-up of 12 months, local tumor control was achieved in 12 of 13 CMR, 8 of 15 IMR receiving boost RT and 0 of 7 IMR without boost RT respectively (p<0.05). Median survival times were 35 (15-63), 22 (8-68), and 12 (8-50) months for CMR, IMR with and IMR without boost RT respectively (p<0.05). Conclusion: The results suggest that immediate postTherapy F-FDG PET/CT may help identify patients with complete versus Incomplete metabolic responses. IMR may benefit from boost RT while CMR can be saved from escalated radiation dose. Clinical trials are needed for validation of immediate post-therapy F-FDG PET/ CT for its potential in guiding individualized therapy.