Jugular venous congestion during off-pump lung transplantation is not associated with an increased risk of postoperative delirium.

INTRODUCTION: Delirium occurs frequently after lung transplantation and is associated with poor clinical outcomes. Significantly prolonged jugular venous congestion (JVC) occurs during off-pump lung transplantation and is thought to impair cerebral perfusion. Our study aimed to test the hypothesis that increased intraoperative JVC is associated with an increased risk of postoperative delirium among lung transplantation recipients. METHODS: This is a retrospective observational cohort study. Adult patients who received off-pump lung transplantation at the Vanderbilt University Medical Center between 2006 and 2016 are included. The magnitude of JVC was calculated by the area under the curve (AUC) of the central venous pressure (CVP) above the threshold of 12 mmHg. Postoperative delirium was assessed by Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) criteria during their ICU stay. Multivariate regression analysis was used to determine the association of intraoperative JVC with postoperative delirium, adjusting for baseline demographics, surgical, and intraoperative characteristics. RESULTS: Thirty-two (23.5%) out of 136 patients developed delirium in the ICU. There was no statistical difference in terms of intraoperative JVC between patients with delirium and those without (4058 ± 6650 vs. 3495 ± 10 151 mmHg min; p = .772). Furthermore, during multivariate regression analysis, JVC was not associated with an increased risk of delirium (odds ratio: 1.03 per 100 mmHg min increase in venous congestion; 95% confidence interval: .31, 3.39; p = .96). CONCLUSIONS: Delirium occurred frequently after off-pump lung transplantation. Although physiologically plausible, the present study did not find an association between increased JVC during off-pump lung transplantation and an increased risk of postoperative delirium.

Clinical course of SARS-CoV-2 infection and recovery in lung transplant recipients.

BACKGROUND: Reports on outcomes following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in lung transplant recipients remain limited. METHODS: We performed a single-center, observational study of outcomes in lung transplant recipients diagnosed with SARS-CoV-2 between 5/1/2020 and 3/15/2022 that were followed for a median of 123 days. We analyzed changes in spirometry, acute lung allograft dysfunction (ALAD) incidence, hospitalization, mechanical ventilation needs, secondary infection, and survival. RESULTS: In our cohort of 336 patients, 103 developed coronavirus disease (COVID) (27 pre-Delta, 20 Delta, and 56 Omicron-era). Twenty-five patients (24%) required hospitalization and 10 patients ultimately died (10%). Among 85 survivors who completed ambulatory spirometry, COVID-19 did not alter change in forced expiratory volume in 1 s (FEV1 ) or forced vital capacity (FVC) over time compared to the preceding 6 months. The pre-COVID FEV1 change was -0.05 ml/day (IQR -0.50 to 0.60) compared to -0.20 ml/day (IQR -1.40 to 0.70) post-COVID (p = .16). The pre-COVID change in FVC was 0.20 ml/day (IQR -0.60 to 0.70) compared to 0.05 ml/day (IQR -1.00 to 1.10) post-COVID (p = .76). Although the cohort overall had stable lung function, 33 patients (39%) developed ALAD or accelerated chronic lung allograft dysfunction (FEV1 decline >10% from pre-COVID baseline). Nine patients (35%) with ALAD recovered lung function. Within 3 months of acute COVID infection, 18 patients (17%) developed secondary infections, the majority being bacterial pneumonia. Finally, vaccination with at least two doses of mRNA vaccine was not associated with improved outcomes. CONCLUSIONS: This study describes the natural history of SARS-CoV-2 infection in a large cohort of lung transplant recipients. Although one third of patients develop ALAD requiring augmented immunosuppression, infection with SARS-CoV-2 is not associated with worsening lung function.

Constrictive bronchiolitis in soldiers returning from Iraq and Afghanistan.

BACKGROUND: In this descriptive case series, 80 soldiers from Fort Campbell, Kentucky, with inhalational exposures during service in Iraq and Afghanistan were evaluated for dyspnea on exertion that prevented them from meeting the U.S. Army's standards for physical fitness. METHODS: The soldiers underwent extensive evaluation of their medical and exposure history, physical examination, pulmonary-function testing, and high-resolution computed tomography (CT). A total of 49 soldiers underwent thoracoscopic lung biopsy after noninvasive evaluation did not provide an explanation for their symptoms. Data on cardiopulmonary-exercise and pulmonary-function testing were compared with data obtained from historical military control subjects. RESULTS: Among the soldiers who were referred for evaluation, a history of inhalational exposure to a 2003 sulfur-mine fire in Iraq was common but not universal. Of the 49 soldiers who underwent lung biopsy, all biopsy samples were abnormal, with 38 soldiers having changes that were diagnostic of constrictive bronchiolitis. In the remaining 11 soldiers, diagnoses other than constrictive bronchiolitis that could explain the presenting dyspnea were established. All soldiers with constrictive bronchiolitis had normal results on chest radiography, but about one quarter were found to have mosaic air trapping or centrilobular nodules on chest CT. The results of pulmonary-function and cardiopulmonary-exercise testing were generally within normal population limits but were inferior to those of the military control subjects. CONCLUSIONS: In 49 previously healthy soldiers with unexplained exertional dyspnea and diminished exercise tolerance after deployment, an analysis of biopsy samples showed diffuse constrictive bronchiolitis, which was possibly associated with inhalational exposure, in 38 soldiers.

Impact of anticoagulation intensity on blood transfusion for venoarterial extracorporeal membrane oxygenation during lung transplantation.

Venoarterial extracorporeal membrane oxygenation is increasingly used for mechanical circulatory support during lung transplant. Optimal intensity of intraoperative anticoagulation would be expected to mitigate thromboembolism without increasing bleeding and blood product transfusions. Yet, the optimal intensity of intraoperative anticoagulation is unknown. We performed a retrospective cohort study of 163 patients who received a bilateral lung transplant at a single center. We categorized the intensity of anticoagulation into 4 groups (very low to high) based on the bolus dose of unfractionated heparin given during lung transplant and compared the rates of intraoperative blood transfusions and the occurrence of thromboembolism between groups. When compared to the very low-intensity group, each higher intensity group was associated with higher red blood cell, fresh frozen plasma, and platelet transfusions. The occurrence of thromboembolism was similar across groups. These preliminary data suggest that lower intensity anticoagulation may reduce the rate of intraoperative blood transfusions, although further study is needed.

Short-term outcomes of robotic-assisted transthoracic diaphragmatic plication.

Background: Patients who are symptomatic from diaphragmatic dysfunction may benefit from diaphragmatic plication. We recently modified our plication approach from open thoracotomy to robotic transthoracic. We report our short-term outcomes. Methods: We conducted a single-institution retrospective review of all patients who underwent transthoracic plications from 2018, when we began using the robotic approach, to 2022. The primary outcome was short-term recurrence of diaphragm elevation with symptoms noted before or during the first planned postoperative visit. We also compared proportions of short-term recurrences in patients that underwent plication with extracorporeal knot-tying device alone versus those that used intracorporeal instrument tying (alone or supplemental). Secondary outcomes included subjective postoperative improvement of dyspnea at follow-up visit and by postoperative patient questionnaire, chest tube duration, length of stay (LOS), 30-day readmission, operative time, estimated blood loss (EBL), intraoperative complications, and perioperative complications. Results: Forty-one patients underwent robotic-assisted transthoracic plication. Four patients experienced recurrent diaphragm elevation with symptoms before or during their first routine postoperative visit, occurring on POD 6, 10, 37, and 38. All four recurrences occurred in patients whose plications were performed with the extracorporeal knot-tying device without supplemental intracorporeal instrument tying. Proportion of recurrences in the group that used extracorporeal knot-tying device alone was significantly greater than the recurrences in the group that used intracorporeal instrument tying (alone or supplemental) (P=0.016). The majority (36/41) reported clinical improvement postoperatively and 85% of questionnaire respondents also agreed they would recommend the surgery to others with similar condition. The median LOS and of chest tube duration were 3 days and 2 days, respectively. There were two patients with 30-day readmissions. Three patients developed postoperative pleural effusion necessitating thoracenteses and 8 patients (20%) had postoperative complications. No mortalities were observed. Conclusions: While our study shows the overall acceptable safety and favorable outcomes in patients undergoing robotic-assisted transthoracic diaphragmatic plications, the incidence of short-term recurrences and its association with the use of extracorporeally knot-tying device alone in diaphragm plication warrant further investigation.

The Thoracic Research Evaluation and Treatment 2.0 Model: A Lung Cancer Prediction Model for Indeterminate Nodules Referred for Specialist Evaluation.

BACKGROUND: Appropriate risk stratification of indeterminate pulmonary nodules (IPNs) is necessary to direct diagnostic evaluation. Currently available models were developed in populations with lower cancer prevalence than that seen in thoracic surgery and pulmonology clinics and usually do not allow for missing data. We updated and expanded the Thoracic Research Evaluation and Treatment (TREAT) model into a more generalized, robust approach for lung cancer prediction in patients referred for specialty evaluation. RESEARCH QUESTION: Can clinic-level differences in nodule evaluation be incorporated to improve lung cancer prediction accuracy in patients seeking immediate specialty evaluation compared with currently available models? STUDY DESIGN AND METHODS: Clinical and radiographic data on patients with IPNs from six sites (N = 1,401) were collected retrospectively and divided into groups by clinical setting: pulmonary nodule clinic (n = 374; cancer prevalence, 42%), outpatient thoracic surgery clinic (n = 553; cancer prevalence, 73%), or inpatient surgical resection (n = 474; cancer prevalence, 90%). A new prediction model was developed using a missing data-driven pattern submodel approach. Discrimination and calibration were estimated with cross-validation and were compared with the original TREAT, Mayo Clinic, Herder, and Brock models. Reclassification was assessed with bias-corrected clinical net reclassification index and reclassification plots. RESULTS: Two-thirds of patients had missing data; nodule growth and fluorodeoxyglucose-PET scan avidity were missing most frequently. The TREAT version 2.0 mean area under the receiver operating characteristic curve across missingness patterns was 0.85 compared with that of the original TREAT (0.80), Herder (0.73), Mayo Clinic (0.72), and Brock (0.68) models with improved calibration. The bias-corrected clinical net reclassification index was 0.23. INTERPRETATION: The TREAT 2.0 model is more accurate and better calibrated for predicting lung cancer in high-risk IPNs than the Mayo, Herder, or Brock models. Nodule calculators such as TREAT 2.0 that account for varied lung cancer prevalence and that consider missing data may provide more accurate risk stratification for patients seeking evaluation at specialty nodule evaluation clinics.

Minimally Invasive and Sublobar Resections for Lung Cancer.

Current guidelines for non-small cell lung cancer (NSCLC) recommend segmentectomy over lobectomy for patients with poor pulmonary reserve or for peripheral nodules less than or equal to 2 cm with adenocarcinoma in situ histology, greater than 50% ground-glass opacity on computed tomography, or radiologic doubling time greater than or equal to 400 days. However, emerging data suggest oncologic equivalence of segmentectomy to lobectomy for less than or equal to 2 cm, peripheral stage IA NSCLC regardless of histologic type or radiographic findings.

Complex Surgical Management of Radiation-Associated Left Retroperitoneal Sarcoma.

Radiation-associated sarcomas (RASs) are rare entities that tend to have an aggressive course and poor prognosis. Criteria for diagnosis of radiation-associated sarcoma include therapeutic radiation preceding the development of sarcoma, sarcoma arising within or near the irradiated field, and tumor histology that is distinct from the primary tumor necessitating radiation. Despite their relatively uncommon occurrence, RASs are a well-established complication of radiation therapy. We present the complex, multidisciplinary surgical management of a patient with multi-compartmental radiation-associated sarcoma of the left retroperitoneum occurring nearly 25 years after undergoing whole trunk radiation for Hodgkin's lymphoma.

Assessment of dd-cfDNA Levels in Clinically Stable Lung Allograft Recipients Beyond the Initial 2 y Posttransplant.

Donor-derived cell-free DNA (dd-cfDNA) is a useful biomarker for the diagnosis of acute allograft injury within the first 1 to 2 y after lung transplant, but its utility for diagnosing chronic lung allograft dysfunction (CLAD) has not yet been studied. Understanding baseline dd-cfDNA kinetics beyond the initial 2 y posttransplant is a necessary first step in determining the utility of dd-cfDNA as a CLAD biomarker. We seek to establish baseline dd-cfDNA% levels in clinically stable lung allograft recipients who are >2 y posttransplant. Methods: We performed a prospective, single-center, observational study to identify plasma dd-cfDNA levels in clinically stable lung allograft recipients >2 y posttransplant. Results: Fifty-one subjects were enrolled and ≥3 baseline dd-cfDNA measurements were acquired during a median of 252 d. The median baseline percent dd-cfDNA level in our cohort was 0.45% (interquartile range [IQR], 0.26-0.69). There were statistically significant differences in dd-cfDNA based on posttransplant duration (≤5 y posttransplant median 0.41% [IQR, 0.21-0.64] versus >5 y posttransplant median 0.50% [IQR, 0.33-0.76]; P < 0.02). However, the clinical significance of this small change in dd-cfDNA is uncertain because this magnitude of change is within the biologic test variation of 73%. Conclusions: This study is the first to define levels of dd-cfDNA in clinically stable patients who are >2 y post-lung transplant. These findings lay the groundwork for the study of dd-cfDNA as a possible biomarker for CLAD.

Communication About the Probability of Cancer in Indeterminate Pulmonary Nodules.

Importance: Clinical guidelines recommend that clinicians estimate the probability of malignancy for patients with indeterminate pulmonary nodules (IPNs) larger than 8 mm. Adherence to these guidelines is unknown. Objectives: To determine whether clinicians document the probability of malignancy in high-risk IPNs and to compare these quantitative or qualitative predictions with the validated Mayo Clinic Model. Design, Setting, and Participants: Single-institution, retrospective cohort study of patients from a tertiary care Department of Veterans Affairs hospital from January 1, 2003, through December 31, 2015. Cohort 1 included 291 veterans undergoing surgical resection of known or suspected lung cancer from January 1, 2003, through December 31, 2015. Cohort 2 included a random sample of 239 veterans undergoing inpatient or outpatient pulmonary evaluation of IPNs at the hospital from January 1, 2003, through December 31, 2012. Exposures: Clinician documentation of the quantitative or qualitative probability of malignancy. Main Outcomes and Measures: Documentation from pulmonary and/or thoracic surgery clinicians as well as information from multidisciplinary tumor board presentations was reviewed. Any documented quantitative or qualitative predictions of malignancy were extracted and summarized using descriptive statistics. Clinicians' predictions were compared with risk estimates from the Mayo Clinic Model. Results: Of 291 patients in cohort 1, 282 (96.9%) were men; mean (SD) age was 64.6 (9.0) years. Of 239 patients in cohort 2, 233 (97.5%) were men; mean (SD) age was 65.5 (10.8) years. Cancer prevalence was 258 of 291 cases (88.7%) in cohort 1 and 110 of 225 patients with a definitive diagnosis (48.9%) in cohort 2. Only 13 patients (4.5%) in cohort 1 and 3 (1.3%) in cohort 2 had a documented quantitative prediction of malignancy prior to tissue diagnosis. Of the remaining patients, 217 of 278 (78.1%) in cohort 1 and 149 of 236 (63.1%) in cohort 2 had qualitative statements of cancer risk. In cohort 2, 23 of 79 patients (29.1%) without any documented malignancy risk statements had a final diagnosis of cancer. Qualitative risk statements were distributed among 32 broad categories. The most frequently used statements aligned well with Mayo Clinic Model predictions for cohort 1 compared with cohort 2. The median Mayo Clinic Model-predicted probability of cancer was 68.7% (range, 2.4%-100.0%). Qualitative risk statements roughly aligned with Mayo predictions. Conclusions and Relevance: Clinicians rarely provide quantitative documentation of cancer probability for high-risk IPNs, even among patients drawn from a broad range of cancer probabilities. Qualitative statements of cancer risk in current practice are imprecise and highly variable. A standard scale that correlates with predicted cancer risk for IPNs should be used to communicate with patients and other clinicians.

Long-Term Physical HRQOL Decreases After Single Lung as Compared With Double Lung Transplantation.

BACKGROUND: Single lung transplantation (SLT) and double lung transplantation (DLT) are associated with differences in morbidity and mortality, although the effects of transplant type on patient-reported outcomes are not widely reported and conclusions have differed. Previous studies compared mean health-related quality of life (HRQOL) scores but did not evaluate potentially different temporal trajectories in the context of longitudinal follow-up. To address this uncertainty, this study was designed to evaluate longitudinal HRQOL after SLT and DLT with the hypothesis that temporal trajectories differ between SLT and DLT. METHODS: Patients transplanted at a single institution were eligible to be surveyed at 1 month, 3 months, 6 months, and then annually after transplant using the Short Form 36 Health Survey, with longitudinal physical component summary (PCS) and mental component summary (MCS) scores as the primary outcomes. Multivariable mixed-effects models were used to evaluate the effects of transplant type and time posttransplant on longitudinal PCS and MCS after adjusting age, diagnosis, rejection, Lung Allocation Score quartile, and intubation duration. Time by transplant type interaction effects were used to test whether the temporal trajectories of HRQOL differ between SLT and DLT recipients. HRQOL scores were referenced to general population norms (range, 40 to 60; mean, 50 ± 10) using accepted standards for a minimally important difference (½ SD, 5 points). RESULTS: Postoperative surveys (n = 345) were analyzed for 136 patients (52% male, 23% SLT, age 52 ± 13 years, LAS 42 ± 12, follow-up 37 ± 29 months [range, 0.6 to 133]) who underwent lung transplantation between 2005 and 2016. After adjusting for model covariates, overall posttransplant PCS scores have a significant downward trajectory (p = 0.015) whereas MCS scores remain stable (p = 0.593), with both averaging within general population norms. The time by transplant type interaction effect (p = 0.002), however, indicate that posttransplant PCS scores of SLT recipients decline at a rate of 2.4 points per year over the total observation period compared to DLT. At approximately 60 months, the PCS scores of SLT recipients, but not DLT recipients, fall below general population norms. CONCLUSIONS: The trajectory of physical HRQOL in patients receiving SLT declines over time compared with DLT, indicating that, in the longer term, SLT recipients are more likely to have physical HRQOL scores that fall substantively below general population norms. Physical HRQOL after 5 years may be a consideration for lung allocation and patient counseling regarding expectations when recommending SLT or DLT.

Assessment of Fluorodeoxyglucose F18-Labeled Positron Emission Tomography for Diagnosis of High-Risk Lung Nodules.

Importance: Clinicians rely heavily on fluorodeoxyglucose F18-labeled positron emission tomography (FDG-PET) imaging to evaluate lung nodules suspicious for cancer. We evaluated the performance of FDG-PET for the diagnosis of malignancy in differing populations with varying cancer prevalence. Objective: To determine the performance of FDG-PET/computed tomography (CT) in diagnosing lung malignancy across different populations with varying cancer prevalence. Design, Setting, and Participants: Multicenter retrospective cohort study at 6 academic medical centers and 1 Veterans Affairs facility that comprised a total of 1188 patients with known or suspected lung cancer from 7 different cohorts from 2005 to 2015. Exposures: 18F fluorodeoxyglucose PET/CT imaging. Main Outcome and Measures: Final diagnosis of cancer or benign disease was determined by pathological tissue diagnosis or at least 18 months of stable radiographic follow-up. Results: Most patients were male smokers older than 60 years. Overall cancer prevalence was 81% (range by cohort, 50%-95%). The median nodule size was 22 mm (interquartile range, 15-33 mm). Positron emission tomography/CT sensitivity and specificity were 90.1% (95% CI, 88.1%-91.9%) and 39.8% (95% CI, 33.4%-46.5%), respectively. False-positive PET scans occurred in 136 of 1188 patients. Positive predictive value and negative predictive value were 86.4% (95% CI, 84.2%-88.5%) and 48.7% (95% CI, 41.3%-56.1%), respectively. On logistic regression, larger nodule size and higher population cancer prevalence were both significantly associated with PET accuracy (odds ratio, 1.027; 95% CI, 1.015-1.040 and odds ratio, 1.030; 95% CI, 1.021-1.040, respectively). As the Mayo Clinic model-predicted probability of cancer increased, the sensitivity and positive predictive value of PET/CT imaging increased, whereas the specificity and negative predictive value dropped. Conclusions and Relevance: High false-positive rates were observed across a range of cancer prevalence. Normal PET/CT scans were not found to be reliable indicators of the absence of disease in patients with a high probability of lung cancer. In this population, aggressive tissue acquisition should be prioritized using a comprehensive lung nodule program that emphasizes advanced tissue acquisition techniques such as CT-guided fine-needle aspiration, navigational bronchoscopy, and endobronchial ultrasonography.

Cytoplasmic clusterin expression is associated with longer survival in patients with resected non small cell lung cancer.

BACKGROUND: Clusterin is a glycoprotein that has been implicated in many processes, including apoptosis, cell cycle regulation, and DNA repair. Previous studies have examined the prognostic value of clusterin expression in various malignancies. In the present study, we examined clusterin staining in tumors resected from patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Tumor specimens were obtained for 113 patients with completely resected NSCLC from paraffin-embedded tissue microarrays and stained with an antibody specific for clusterin. Staining patterns were observed and graded based on intensity and then correlated with clinical data. RESULTS: Positive cytoplasmic clusterin staining was observed in 44 patients, and weak/negative staining was observed in 62 patients. Patients who had tumors that stained positive for cytoplasmic clusterin had significantly longer survival in multivariate analysis (hazard ratio 0.487, 95% confidence interval 0.27-0.89). A correlation was also observed for recurrence-free survival, which approached statistical significance (hazard ratio 0.345, 95% confidence interval 0.12-1.02). In univariate analysis, patients with clusterin-positive tumors had a 63% 3-year survival, whereas patients with clusterin-negative tumors had a 42% 3-year survival (P = 0.0108); clusterin-positive tumors also had significantly less recurrence (P = 0.0231). CONCLUSIONS: Cytoplasmic clusterin staining is present in a substantial number of NSCLC tumors and may be a biomarker for longer survival in patients with surgically resected NSCLC.

Timeliness of Care and Lung Cancer Tumor-Stage Progression: How Long Can We Wait?

BACKGROUND: Timely care of lung cancer is presumed critical, yet clear evidence of stage progression with delays in care is lacking. We investigated the reasons for delays in treatment and the impact these delays have on tumor-stage progression. METHODS: We queried our retrospective database of 265 veterans who underwent cancer resection from 2005 to 2015. We extracted time intervals between nodule identification, diagnosis, and surgical resection; changes in nodule radiographic size over time; final pathologic staging; and reasons for delays in care. Pearson's correlation and Fisher's exact test were used to compare cancer growth and stage by time to treatment. RESULTS: Median time from referral to surgical evaluation was 11 days (interquartile range, 8 to 17). Median time from identification to therapeutic resection was 98 days (interquartile range, 66 to 139), and from diagnosis to resection, 53 days (interquartile range, 35 to 77). Sixty-eight patients (26%) were diagnosed at resection; the remainder had preoperative tissue diagnoses. No significant correlation existed between tumor growth and time between nodule identification and resection, or between tumor growth and time between diagnosis and resection. Among 197 patients with preoperative diagnoses, 42% (83) had intervals longer than 60 days between diagnosis and resection. Most common reasons for delay were cardiac clearance, staging, and smoking cessation. Larger nodules had fewer days between identification and resection (p = 0.03). CONCLUSIONS: Evaluation, staging, and smoking cessation drive resection delays. The lack of association between tumor growth and time to treatment suggests other clinical or biological factors, not time alone, underlie growth risk. Until these factors are identified, delays to diagnosis and treatment should be minimized.

Cardiovascular complications after lung surgery.

Cardiovascular complications following thoracic surgery remain a challenge to the physician, the hospital, and the health care system. These events add significantly to morbidity, mortality, and the cost of care of the general thoracic surgery patient. A proactive approach to identify patients at high risk for such complications is needed. In this manner, one may enhance prevention and treatment if problems occur. A thoughtful and complete preoperative risk assessment can identify patients who have potential contributing comorbidities, leading to a reduced incidence of postoperative events. Standardization of preoperative, intraoperative, and postoperative care can reduce postoperative events. Implementation of guidelines and pathways that are evidence based can lead to enhanced patient care, better patient and staff satisfaction, and improved outcomes from the operation. Although postoperative cardiac events cannot be completely eliminated from the thoracic surgery population, the prevention, treatment, and follow-up strategies outlined herein can attenuate these significant morbid and mortal events.

Predicting lung cancer prior to surgical resection in patients with lung nodules.

BACKGROUND: Existing predictive models for lung cancer focus on improving screening or referral for biopsy in general medical populations. A predictive model calibrated for use during preoperative evaluation of suspicious lung lesions is needed to reduce unnecessary operations for a benign disease. A clinical prediction model (Thoracic Research Evaluation And Treatment [TREAT]) is proposed for this purpose. METHODS: We developed and internally validated a clinical prediction model for lung cancer in a prospective cohort evaluated at our institution. Best statistical practices were used to construct, evaluate, and validate the logistic regression model in the presence of missing covariate data using bootstrap and optimism corrected techniques. The TREAT model was externally validated in a retrospectively collected Veteran Affairs population. The discrimination and calibration of the model was estimated and compared with the Mayo Clinic model in both the populations. RESULTS: The TREAT model was developed in 492 patients from Vanderbilt whose lung cancer prevalence was 72% and validated among 226 Veteran Affairs patients with a lung cancer prevalence of 93%. In the development cohort, the area under the receiver operating curve (AUC) and Brier score were 0.87 (95% confidence interval [CI], 0.83-0.92) and 0.12, respectively compared with the AUC 0.89 (95% CI, 0.79-0.98) and Brier score 0.13 in the validation dataset. The TREAT model had significantly higher accuracy (p < 0.001) and better calibration than the Mayo Clinic model (AUC = 0.80; 95% CI, 75-85; Brier score = 0.17). CONCLUSION: The validated TREAT model had better diagnostic accuracy than the Mayo Clinic model in preoperative assessment of suspicious lung lesions in a population being evaluated for lung resection.

Tissue-based coronary surgery simulation: medical student deliberate practice can achieve equivalency to senior surgery residents.

OBJECTIVE: The study objective was to assess the impact of dedicated instruction and deliberate practice on fourth-year medical students' proficiency in performing a coronary anastomosis using a porcine heart model, compared with nonsimulator-trained senior general surgery residents. METHODS: Ten fourth-year medical students were trained to perform a coronary anastomosis using the porcine simulator. Students trained for 4 months using deliberate practice methodology and one-on-one instruction. At the end of the training, each student was filmed performing a complete anastomosis. Eleven senior general surgery residents were filmed performing an anastomosis after a single tutorial. All films were graded by 3 independent cardiac surgeons in a blinded fashion. The primary outcome was the median final score (range, 1-10) of a modified Objective Structured Assessment of Technical Skill scale. The secondary outcome was time to completion in seconds. Statistical analysis used both parametric (Student t test) and nonparametric (Wilcoxon rank-sum) methods. RESULTS: The median combined final score for medical students was 3 (interquartile range, 2.3-4.8), compared with 4 (interquartile range, 3.3-5.3) for residents (P = .102). The overall median individual final scores were 3 (interquartile range, 2-6) for grader 1, 3 (interquartile range, 2-5) for grader 2, and 4 (interquartile range, 3-5) for grader 3. For each individual grader, there was no difference in median final scores between medical students and residents. The mean time to completion was 792.7 seconds (95% confidence interval, 623.4-962) for medical students and 659 seconds (95% confidence interval, 599.1-719) for residents (P = .118). CONCLUSIONS: Dedicated instruction of fourth-year medical students with deliberate and distributed practice of microvascular techniques using a porcine end-to-side coronary artery anastomosis simulation model results in performance comparable to that of senior general surgery residents. These results suggest that focused tissue simulator training can compress the learning curve to acquire technical proficiency in comparison with real-time training.

Obesity increases operating room time for lobectomy in the society of thoracic surgeons database.

BACKGROUND: Obesity has become a major epidemic in the United States. Although research suggests obesity does not increase major morbidity or mortality after thoracic operations, it likely results in greater use of health care resources. METHODS: We examined all patients in The Society of Thoracic Surgeons General Thoracic Surgery database with primary lung cancer who underwent lobectomy from 2006 to 2010. We investigated the impact of body mass index (BMI) on total operating room time using a linear mixed-effects regression model and multiple imputations to account for missing data. Secondary outcomes included postoperative length of stay and 30-day mortality. Covariates included age, sex, race, forced expiratory volume, smoking status, Zubrod score, prior chemotherapy or radiation, steroid use, number of comorbidities, surgical approach, hospital lobectomy volume, hospital percent obesity, and the addition of mediastinoscopy or wedge resection. RESULTS: A total of 19,337 patients were included. The mean BMI was 27.3 kg/m2, with 4,898 patients (25.3%) having a BMI of 30 kg/m2 or greater. The mean total operating room time, length of stay, and 30-day mortality were 240 minutes, 6.7 days, and 1.8%, respectively. For every 10-unit increase in BMI, mean operating room time increased by 7.2 minutes (range, 4.8 to 8.4 minutes; p<0.0001). Higher hospital lobectomy volume and hospital percentage of obese patients did not affect the association between BMI and operative time. Body mass index was not associated with 30-day mortality or increased length of stay. CONCLUSIONS: Increased BMI is associated with increased total operating room time, regardless of institutional experience with obese patients.