Postoperative Forced Expiratory Volume Research Articles

Effect of Resected Lung Volume on Pulmonary Function and Residual Lung Volume in Patients Undergoing Segmentectomy: A Retrospective Study.

We elucidated the effects of planned resection volume on postoperative pulmonary function and changes in residual lung volume during segmentectomy. This study included patients who underwent thoracoscopic segmentectomy between January 2017 and December 2022 and met eligibility criteria. Pre- and post-resection spirometry and computed tomography were performed. Three-dimensional reconstructions were performed by using computed tomography images to calculate the volumes of the resected, remaining, and nonoperative side regions. Based on the resected region volume, patients were divided into the higher and lower volume segmentectomy groups. Changes in lung volume and pulmonary function before and after the surgery were comparatively analyzed. The median percentage of resected lung volume was 10.9%, forming the basis for categorizing patients into the two groups. Postoperative forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) ratios to preoperative measurements in both groups did not differ significantly (FEV1, p = 0.254; FVC, p = 0.777). Postoperative FEV1 and FVC ratios to their predicted postoperative values were significantly higher in the higher volume segmentectomy group than in the lower volume segmentectomy group (FEV1, p = 0003; FVC, p < 0.001). The higher volume segmentectomy group showed significantly greater post-to-preoperative lung volume ratio in overall, contralateral, ipsilateral, residual lobe and residual segment than the lower volume segmentectomy group. Postoperative respiratory function did not differ significantly between the higher- and lower-volume segmentectomy groups, indicating improved respiratory function because of substantial postoperative residual lung expansion. Our findings would aid in determining the extent of resection during segmentectomy.

The effect of lobar shifting following right upper lobectomy on postoperative pulmonary function.

Lobes occasionally displace after lobectomy, referred to as "lobar shifting". However, the benefits, especially in postoperative pulmonary function, remain controversial. This study aimed to measure the effect of lobar shifting on postoperative pulmonary function especially in the right upper lobe. This retrospective study includes 273 right upper lobectomy patients (lobectomy group) and 24 right upper segmentectomy patients (segmentectomy group) from 2012 to 2021. The lobectomy group was further subdivided based on their Synapse Vincent® image: with their postoperative middle lobe bronchus shifted toward the head (shift group: 176 cases) and without (non-shift group: 97 cases). Several factors were examined to determine the cause of lobar shifting. The rate of measured actual postoperative forced expiratory volume in 1s (FEV1.0) to predicted postoperative FEV1.0 was analyzed and compared among the three groups. Factors that correlated with lobar shifting included age (p < 0.001), a relatively small middle lobe volume (p = 0.03), no adhesions (p < 0.001), and good upper/middle and middle/lower lobulation (p = 0.04, p = 0.02). The rate of measured actual postoperative FEV1.0 to predicted postoperative FEV1 for the shift, non-shift, and segmentectomy groups were 112.5%, 107.9%, and 103.1% (shift vs non-shift: p = 0.04, shift vs segmentectomy: p = 0.02, non-shift vs segmentectomy: p = 0.19). Lobar shifting after right upper lobectomy is influenced by morphological factors and may have a beneficial impact on postoperative pulmonary function.

Compensatory expansion of the right middle lobe: volumetric and functional analysis of the changes after right upper or lower lobectomy.

The right middle lobe often poorly expands after right upper lobectomy. Postoperative pulmonary function may be inferior after right upper lobectomy than after right lower lobectomy due to poor expansion of the middle lobe. This study examined the difference in the postoperative right middle lobe expansion and pulmonary function between right upper and right lower lobectomy. Patients who underwent right upper or right lower lobectomy through video-assisted thoracic surgery (n = 82) were enrolled in this retrospective study. Pulmonary function tests and computed tomography were performed preoperatively and at 1year postoperatively. Using three-dimensional computed tomography volumetry, the preoperative and postoperative lung volumes were measured, and the predicted postoperative forced expiratory volume in 1s was calculated. Middle lobe volume ratio (i.e., ratio of the postoperative to the preoperative middle lobe volume) and the postoperative forced expiratory volume in 1s ratio (i.e., ratio of the measured to the predicted postoperative forced expiratory volume in 1s) were compared between right upper and right lower lobectomy. Compared with the patients who underwent right upper lobectomy (n = 50), those who underwent right lower lobectomy (n = 32) had significantly higher middle lobe volume ratio (1.15 ± 0.32 vs. 1.63 ± 0.52, p < 0.001) and postoperative forced expiratory volume in 1s ratio (1.12 ± 0.12 vs. 1.19 ± 0.13, p = 0.010). The right middle lobe showed more expansion and better recovery of postoperative pulmonary function after right lower lobectomy than after right upper lobectomy.

Implementation of an enhanced recovery protocol for lung volume reduction surgery: an observational cohort study.

Lung volume reduction surgery (LVRS) is an established therapeutic option for advanced emphysema. To improve patients' safety and reduce complications, an enhanced recovery protocol (ERP) was implemented. This study aims to describe and evaluate the short-term outcome of this ERP. This retrospective single-centre study included all consecutive LVRS patients (1 January 2017 until 15 September 2020). An ERP for LVRS was implemented and stepwise optimised from 1 August 2019, it consisted of changes in pre-, peri- and postoperative care pathways. Patients were compared before and after implementation of ERP. Primary outcome was incidence of postoperative complications (Clavien-Dindo), and secondary outcomes included chest tube duration, incidence of prolonged air leak (PAL), length of stay (LOS) and 90-day mortality. Lung function and exercise capacity were evaluated at 3 and 6 months post-LVRS. Seventy-six LVRS patients were included (pre-ERP: n=41, ERP: n=35). The ERP cohort presented with lower incidence of postoperative complications (42% vs 83%, P=0.0002), shorter chest tube duration (4 vs 12 days, P<0.0001) with a lower incidence of PAL (21% vs 61%, P=0.0005) and shorter LOS (6 vs 14 days, P<0.0001). No in-hospital mortality occurred in the ERP cohort versus 4 pre-ERP. Postoperative forced expiratory volume in 1 s was higher in the ERP cohort compared to pre-ERP at 3 months (1.35 vs 1.02 l) and at 6 months (1.31 vs 1.01 l). Implementation of ERP as part of a comprehensive reconceptualisation towards LVRS, demonstrated fewer postoperative complications, including PAL, resulting in reduced LOS. Improved short-term functional outcomes were observed at 3 and 6 months.

A Machine Learning Multilayer Meta-Model for Prediction of Postoperative Lung Function in Lung Cancer Patients

The goal of this paper is to inform the machine learning community of our results obtained during the development of a system for the assessment of the postoperative lung function of patients suffering from lung cancer. The system is based on a new multilayer regression meta-model, which predicts individual postoperative forced expiratory volume in 1 second (poFEV1) for each patient based on preoperative measurements. The proposed regression models are especially trained to predict this key indicator for the 1st, 4th, and 7th day after surgery. Based on our knowledge, this is the first attempt to obtain poFEV1 in the most critical postoperative period of the first seven days. The high accuracy of the proposed predictive meta-model allows surgeons a number of key insights, starting with whether the patient is suitable for surgical intervention, and ending with the preparation of individualized postoperative treatment. It should be noted that the existing, widely used predictive models, based on functional segments (FC), Juhl-Forst, and Nakahara formulas, give two to three times worse results compared to the proposed new regression meta-model. Based on the SHapley Additive explanations (SHAP) value of the trained meta-model, it is possible to obtain a complete picture of the partial effects of each prognostic factor for each patient preoperatively on the outcome of the surgical intervention. In addition, the global model interpretation by SHAP values reveals some new interdependencies that were not known in medical circles until now. For instance, the influence of age and biomass index on the condition of the patient on the first day after surgery, or the constant significant influence of muscular support for inhalation in the entire seven-day follow-up period.

Predicting postoperative lung function using ventilation SPECT/CT in patients with lung cancer.

Single-photon emission computed tomography/computed tomography (SPECT/CT) has the advantage of assessing regional lung function. We aimed to investigate the potential of ventilation (SPECT/CT) for predicting postoperative lung function in patients with lung cancer. This retrospective study included consecutive patients with lung cancer who underwent lobectomy, preoperative ventilation, and perfusion SPECT/CT between January 2020 and December 2021. The percentage of predicted postoperative forced expiratory volume in 1 s (ppoFEV1%) and the percentage of predicted postoperative diffusion capacity of the lung for carbon monoxide (ppoDLCO%) were calculated from the % counts of each scan based on anatomical segments for lobar function. Correlation tests were performed between the predicted lung function values and actual ppoFEV1% and ppoDLCO%. Among the 47 patients, 29 men and 18 women aged 67.5±9.6 years were included. Moreover, 46 ventilation and 41 perfusion SPECT/CT scans were obtained. The pulmonary function on ventilation SPECT/CT strongly correlated with perfusion SPECT/CT (correlation coefficient r=0.939 for ppoFEV1%, P<0.001; r=0.938 for ppoDLCO%, P<0.001). Both ppoFEV1% and ppoDLCO% values obtained from the ventilation and perfusion scans strongly correlated with postoperative FEV1% and DLCO% (correlation coefficient, r=0.774 and r=0.768 for ventilation; r=0.795 and r=0.751 for perfusion, each P<0.001). Ventilation SPECT/CT was comparable to perfusion SPECT/CT in predicting postoperative lung function.

What are the risk factors for postoperative home oxygen therapy in patients with lung cancer?

Home oxygen therapy (HOT) is used to treat chronic respiratory diseases and is sometimes required in patients with lung cancer after radical surgery. We aimed to identify the risk factors for postoperative home-based oxygen therapy in patients with lung cancer. Patients who underwent surgery for primary lung cancer at Chiba University Hospital between January 2019 and March 2021 were included. Patients who did not undergo complete resection, died in hospital after surgery, or used oxygen therapy preoperatively were excluded. Eligible patients were divided into HOT and non-HOT groups. They were retrospectively analyzed for risk factors for postoperative HOT using medical records in a multivariate analysis. A total of 410 patients were included in this study, 24 (5.9%) of whom required HOT after surgery. The HOT group comprised significantly more men, heavy smokers, and patients with pulmonary comorbidities, low percent forced expiratory volume, percent forced vital capacity, predicted postoperative forced expiratory volume in 1 s, and postoperative pulmonary complications on univariate analysis. In a multivariate analysis, independent risk factors for postoperative HOT were pulmonary comorbidities [odds ratio (OR): 5.94; 95% confidence interval (CI): 1.64-21.5; P=0.002) and postoperative pulmonary complications (OR: 5.39; 95% CI: 2.14-13.5; P<0.001). The postoperative HOT application rate was calculated according to a formula developed for this purpose. Comorbid pulmonary diseases and postoperative pulmonary complications were significantly associated with postoperative HOT in patients with lung cancer.

Agreement between observed and predicted postoperative forced expiratory volume in one second, forced vital capacity, and diffusing capacity for carbon monoxide after anatomic lung resection.

Despite its importance in clinical practice, clinical guideline pathway selection and as an outcome in clinical trials, little work has been undertaken to understand the agreement between expected lung function loss and actual observed values. This is particular pertinent in view of the unexpected findings of JCOG 0802 and CALBG 140503 demonstrating no clinically meaningful difference in lung function loss between the sub-lobar resection and lobectomy arm. We performed a retrospective analysis on preoperative and postoperative forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO) collated from 158 patients who underwent anatomical lung resection between January 2013 to July 2023. Patient's true preoperative and postoperative lung function was obtained via formal lung function testing while predicted postoperative lung function was derived using the 20-segment counting method. Longitudinal postoperative lung function analysis demonstrated sufficient stability over time. A formal testing of agreement between predicted and true postoperative lung function was undertaken using the Bland and Altman method and graphically demonstrated using scatter plots. We defined a deviation of more than 5% as a clinically minimally important difference. Scatter plots for effort-dependent measures suggested the tendency for underprediction (observed values were higher than predicted) for FEV1 and FVC but good agreement for DLCO. Formal agreement confirmed mean difference for FEV1 was -9.84% [95% confidence interval (CI): -39.33% to 19.65%], FVC -11.39% (95% CI: -50.14% to 27.36%) and DLCO -4.83% (95% CI: -25.59% to 15.92%). Our study demonstrated that effort-dependent parameters of lung function including FEV1 and FVC tends to overestimate the amount of lung function loss after anatomic lung resection, clinicians should be cautious in using these measures to determine suitability of surgery based on current established guidelines. However, independent measures such as DLCO demonstrate good agreement suggesting that predicted lung tissue loss is consistent with a 20-segment lung model.

Clinical Implications of Removing Race-Corrected Pulmonary Function Tests for African American Patients Requiring Surgery for Lung Cancer

Removal of race correction in pulmonary function tests (PFTs) is a priority, given that race correction inappropriately conflates race, a social construct, with biological differences and falsely assumes worse lung function in African American than White individuals. However, the impact of decorrecting PFTs for African American patients with lung cancer is unknown. To identify how many hospitals providing lung cancer surgery use race correction, examine the association of race correction with predicted lung function, and test the effect of decorrection on surgeons' treatment recommendations. In this quality improvement study, hospitals participating in a statewide quality collaborative were contacted to determine use of race correction in PFTs. For hospitals performing race correction, percent predicted preoperative and postoperative forced expiratory volume in 1 second (FEV1) was calculated for African American patients who underwent lung cancer resection between January 1, 2015, and September 31, 2022, using race-corrected and race-neutral equations. US cardiothoracic surgeons were then randomized to receive 1 clinical vignette that differed by the use of Global Lung Function Initiative equations for (1) African American patients (percent predicted postoperative FEV1, 49%), (2) other race or multiracial patients (percent predicted postoperative FEV1, 45%), and (3) race-neutral patients (percent predicted postoperative FEV1, 42%). Number of hospitals using race correction in PFTs, change in preoperative and postoperative FEV1 estimates based on race-neutral or race-corrected equations, and surgeon treatment recommendations for clinical vignettes. A total of 515 African American patients (308 [59.8%] female; mean [SD] age, 66.2 [9.4] years) were included in the study. Fifteen of the 16 hospitals (93.8%) performing lung cancer resection for African American patients during the study period reported using race correction, which corresponds to 473 African American patients (91.8%) having race-corrected PFTs. Among these patients, the percent predicted preoperative FEV1 and postoperative FEV1 would have decreased by 9.2% (95% CI, -9.0% to -9.5%; P < .001) and 7.6% (95% CI, -7.3% to -7.9%; P < .001), respectively, if race-neutral equations had been used. A total of 225 surgeons (194 male [87.8%]; mean [SD] time in practice, 19.4 [11.3] years) were successfully randomized and completed the vignette items regarding risk perception and treatment outcomes (76% completion rate). Surgeons randomized to the vignette with African American race-corrected PFTs were more likely to recommend lobectomy (79.2%; 95% CI, 69.8%-88.5%) compared with surgeons randomized to the other race or multiracial-corrected (61.7%; 95% CI, 51.1%-72.3%; P = .02) or race-neutral PFTs (52.8%; 95% CI, 41.2%-64.3%; P = .001). Given the findings of this quality improvement study, surgeons should be aware of changes in PFT testing because removal of race correction PFTs may change surgeons' treatment decisions and potentially worsen existing disparities in receipt of lung cancer surgery among African American patients.

Performance Comparison of Pulmonary Risk Scoring Systems in Lung Resection

To validate and compare the performance of different pulmonary risk scoring systems to predict postoperative pulmonary complications (PPCs) in lung resection surgery. Retrospective cohort study SETTING: A historic single-center cohort of lung resection surgeries PARTICIPANTS: Adult patients undergoing lung resection surgery under 1-lung ventilation. None. The accuracy of the following pulmonary risk scoring systems were used to predict pulmonary complications: the ARISCAT (Assess respiratory RIsk in Surgical patients in CATalonia), the LAS VEGAS (Local Assessment of VEntilatory management during General Anesthesia for Surgery), the SPORC (Score for Prediction of Postoperative Respiratory Complications), and a recent thoracic-specific risk score, named CARDOT. Discrimination and calibration were assessed using the concordance (c) index and the intercept of LOESS (locally estimated scatterplot)-smoothed curves, respectively. Additional models were constructed that incorporated predicted postoperative forced expiratory volume (ppoFEV1) into each scoring system. Of the 2,104 patients undergoing lung surgery, 123 developed postoperative pulmonary complications (PPCs; 5.9%). All scoring systems had poor discriminatory power to predict PPCs (ARISCAT c-index 0.60, 95% confidence interval [CI] 0.55-0.65; LAS VEGAS c-index 0.68, 95% CI 0.63-0.73; SPORC c-index 0.63, 95% CI 0.59-0.68; CARDOT c-index 0.64, 95% CI 0.58-0.70), but the inclusion of ppoFEV1 slightly improved the performance of LAS VEGAS (c-index 0.70, 95% CI 0.66-0.75) and CARDOT (c-index 0.68, 95% CI 0.62-0.73). Analysis of calibration showed a slight overestimation when using ARISCAT (intercept -0.28) and LAS VEGAS (intercept -0.27). None of the scoring systems appeared to have adequate discriminatory power to predict PPCs among patients undergoing lung resection. An alternative risk score is necessary to better predict patients at risk of PPCs after thoracic surgery.

Pulmonary function protection by single-port thoracoscopic segmental lung resection in elderly patients with IA non-small cell lung cancer: A differential matched analysis.

In patients with stage IA non-small cell lung cancer (NSCLC), uniportal video-assisted thoracic surgery (U-VATS) anatomical segmentectomy removes the lung tumor while preserving lung function as much as possible, and it is therefore an alternative to lobectomy. Patients with stage IA NSCLC receiving U-VATS segmental resection at our institution from September 2017 to June 2019 were compared with patients receiving U-VATS lobectomy. A total of 47 patients received segmentectomy and 209 patients received U-VATS lobectomy in the same period. Propensity score matching was conducted to diminish bias. The final study cohort included 42 patients who received segmentectomy and 42 propensity score matching-matched patients who received lobectomy. Perioperative parameters and postoperative complications, length of hospital stay, postoperative forced expiratory volume in 1 s (FEV1), and forced vital capacity (FVC) were compared between the 2 groups. Surgery was successfully completed in all patients. The mean follow-up was for 8.2 months. The postoperative complication rate was comparable between the 2 groups: 31.0% in segmentectomy patients versus 35.7% in lobectomy patients (P = .643). At 1 month after surgery, FEV1% and FVC% were not significantly different between the 2 groups (P > .05). At 3 months after surgery, FEV1 and FVC were higher in segmentectomy patients than in lobectomy patients (FEV1, 82.79% ± 6.36% vs 78.55% ± 5.42%; FVC, 81.66% ± 6.09% vs 78.90% ± 5.58%, P < .05). Patients receiving segmentectomy suffer less pain and have better postoperative lung function and higher quality of life.

Does thoracoscopic basal pyramid segmentectomy really offer functional advantages in comparison with thoracoscopic lower lobectomy?

The functional impact of thoracoscopic basal segmentectomy in comparison with lower lobectomy has not been investigated in-depth and the aim of this study was to clarify this topic. We retrospectively analysed a cohort of patients who underwent surgery between 2015 and 2019 for non-small-cell lung cancer, peripherally located lung nodules, far enough from both the apical segment and the lobar hilum to allow an oncologically safe thoracoscopic lower lobectomy or basal segmentectomy. Pulmonary function tests (PFTs) including spirometry and plethysmography were performed 1 month after surgery and forced expiratory volume in 1 s, forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO) were collected; the difference, the loss and the recovery rate of pulmonary function were calculated and compared with the Wilcoxon-Mann-Whitney test. During the study period, n = 45 and n = 16 patients for video-assisted thoracoscopic surgery (VATS) lower lobectomy and for VATS basal segmentectomy, respectively, completed the study protocol: the 2 groups were homogeneous as to preoperative variables and PFT values. Postoperative outcomes were similar and PFTs revealed significant differences between postoperative forced expiratory volume in 1 s %, FVC%, ΔFVC and ΔFVC%. The loss percentage of FVC%, DLCO% and the recovery rate was better for FVC and DLCO in the VATS basal segmentectomy group. Thoracoscopic basal segmentectomy seems to be associated with a more preserved lung function, maintaining more FVC and DLCO levels than lower lobectomy, and could be performed in selected cases ensuring also adequate oncological margins.

The dynamic pulmonary functional change after thoracoscopic lower lobe segmentectomy.

The advantages of segmentectomy over lobectomy in sparing pulmonary function remain controversial. Lower lobe segmentectomy is divided into simple segmentectomy, such as segment 6; and complex segmentectomy that includes the basal segments. Here, we compared residual lung function after thoracoscopic segmentectomy versus lobectomy in the lower lobe using the three-dimensional computed tomography volumetric method. Between January 2012 and October 2020, 67 patients who underwent thoracoscopic segmentectomy of the lower lobe were matched to 67 patients who underwent thoracoscopic lower lobectomy during the same period using propensity score matching analysis. The postoperative decrease in the rate of forced expiratory volume in 1 s was compared between methods. The regional forced expiratory volume in 1 s of the residual lobe rescued by segmentectomy was measured using volumetric and spirometric analyses and compared to lower lobectomy. The ratio of the actual to predicted postoperative forced expiratory volume in 1 s in the residual lobe was defined as the preservation rate. Of the 67 thoracoscopic segmentectomies, 43 were S6, seven were S8, three were S8 + 9, seven were S10, and seven were S9 + 10. The percentage of postoperative/preoperative forced expiratory volume in 1 s was significantly higher in the segmentectomy versus lobectomy group (90.7% vs. 85.7%, p = 0.001). The preservation rates after simple segmentectomy (n = 43) and complex segmentectomy (n = 24) did not differ significantly (82.2% vs. 80.2%, p = 0.709). Thoracoscopic lower lobe segmentectomy versus lobectomy preserves postoperative lung function. Even complex segmentectomy exhibited outcomes relevant to simple segmentectomy by sparing the residual lobe.

External validation of risk prediction scores in patients undergoing anatomic video-assisted thoracoscopic resection

BackgroundEuroLung Risk scores were established to predict postoperative morbidity and mortality in patients undergoing anatomic lung resections. We aimed to perform an external validation of the EuroLung scores, which were calculated from data of the European Society of Thoracic Surgeons database, in our video-assisted thoracoscopic surgery cohort.MethodsAll available EuroLung scores were calculated for 718 patients scheduled for anatomic video-assisted thoracoscopic surgery resections between 2009 and 2019. Morbidity and mortality according to the definitions of the EuroLung scores were analyzed in a prospectively maintained database.ResultsOverall observed complication rate was 10.45%. Scores showed weak individual correlation (η = 0.155–0.174). The EuroLung1 app score showed the biggest area under the receiver operative characteristic (ROC) curve with 0.660. Binary logistic regression analysis showed that predicted postoperative forced expiratory volume in 1 s was associated with increased complications in both EuroLung1 and parsimonious EuroLung1 scores. Thirty-day mortality was 0.7% (predicted 1.10–1.40%) and was associated with predicted postoperative forced expiratory volume in 1 s for both EuroLung2 and parsimonious EuroLung2 scores. The EuroLung2 (2016) showed the biggest area under the ROC curve with 0.673. Only a very weak eta correlation between predicted and observed mortality was found for both aggregate EuroLung2, EuroLung2 (2016), EuroLung2 (2019), and parsimonious EuroLung2 (2016) (η = 0.025/0.015/0.011/0.009).ConclusionEuroLung scores help to estimate postoperative morbidity. However, even with the highest aggregate EuroLung scores possible only 50% suffer from postoperative morbidity. Although calibration of the scores was acceptable, discrimination between predicted and observed events was poor. Therefore, individual correlation between predicted and observed events is weak. Therefore, EuroLung scores may be best used to compare institutional quality of care to the European Society of Thoracic Surgeons database but should not be used to preclude patients from surgical treatment.

Risk Stratification for Lung Cancer Patients.

A comprehensive review ofrelevant clinical literature on evidence-based recommendations and existing prediction models specific to lung cancer surgery was undertaken. Preoperative risk assessment parameters such as pulmonary function tests (PFT), cardiopulmonary exercise testing (CPET), Brunelli models, Thoracoscore and frailty were analyzed forpredicting postoperative risk of complications. When assessing fitness for surgery, the primarily used PFT parameters such as predictive postoperative forced expiratory volume in one second (FEV1) and diffusion capacity for carbon monoxide(DLCO ) showed conflicting evidence in determining a positive correlation with postoperative mortality. CPET variables predicted higher complication risk whenVO2peak < 10ml/kg/min, AT < 11ml/kg/min and ventilation/carbon dioxide production (VE/VCO2) was in range of 34-40. While a cardiac risk index like the Thoracic Revised Cardiac Risk Index (ThRCRI) predicted major cardiovascular compromise, athoracic risk index like Thoracoscore proved imprecise. Lastly, frailty is used to risk stratify patients in clinical practice but a recognized validated model specific to thoracic surgery is non-existent. When considering patients for lung cancer surgery, some dilemma exists regarding the accuracy of clinical prediction models and their external validation. There is a pressing need for the development of a consolidated clinically robust risk stratification model to predict complications after thoracic resections.

Effect of resected lung lobe on the prediction of postoperative pulmonary function.

This study examined whether a resected lung lobe can affect the accuracy of postoperative forced expiratory volume in 1 s (FEV1) predicted using the subsegment counting method and three-dimensional computed tomography (3D-CT) volumetry. Overall, 125 patients who underwent lobectomy through video-assisted thoracic surgery were enrolled in this retrospective study. Pulmonary function tests were performed preoperatively and postoperatively at 3 months. We defined the accuracy index as the ratio of predicted postoperative FEV1 to measured postoperative FEV1 and compared the accuracy index of the subsegment counting method and 3D-CT volumetry. Factors affecting the accuracy index were also examined. The accuracy index of the subsegment counting method was 0.94 ± 0.12, versus 0.93 ± 0.11 for 3D-CT volumetry (P = 0.539). There was a significant difference among the resected lobes in the accuracy index of the subsegment counting method (P < 0.001) but not in that of 3D-CT volumetry (P = 0.370). The resected lobe, the number of staples used for interlobar dissection and interstitial pneumonia were significantly associated with the accuracy index of the subsegment counting method (all P < 0.001). The number of staples and interstitial pneumonia were significantly associated with the accuracy index of 3D-CT volumetry (P < 0.001, respectively), whereas the resected lobe was not a significant factor (P = 0.240). The resected lobe affected the accuracy of the subsegment counting method but not that of 3D-CT volumetry. Furthermore, 3D-CT volumetry predicted postoperative FEV1 independent of the resected lobe.

Airflow patterns in the trachebronchial tree of a patient with an accessory cardiac bronchus: A rare congenital anomaly

Accessory cardiac bronchus (ACB) is a rare congenital anomaly mainly located in the medial wall of the intermediate bronchus. This anomaly can present with dyspnea, recurrent infections, and hemoptysis. It usually has a blind ending, which may have an impact on airflow patterns and lobar distribution regardless of its diameter and depth. There have been very few cases with ACB. However, the airflow pattern and lobar distribution have not been well studied. In our case with ACB, the proportion of airflow in the right lung was higher than in the model without ACB, while mean airflow velocities were similar in both models. In this regard, quantitative lung ventilation scintigraphy could be better than the anatomical formula in predicting postoperative forced expiratory volume 1 in patients with accessory cardiac bronchus who will undergo lung resection.

Prediction of postoperative cardiopulmonary complications after lung resection in a Chinese population: A machine learning-based study.

BackgroundApproximately 20% of patients with lung cancer would experience postoperative cardiopulmonary complications after anatomic lung resection. Current prediction models for postoperative complications were not suitable for Chinese patients. This study aimed to develop and validate novel prediction models based on machine learning algorithms in a Chinese population.MethodsPatients with lung cancer receiving anatomic lung resection and no neoadjuvant therapies from September 1, 2018 to August 31, 2019 were enrolled. The dataset was split into two cohorts at a 7:3 ratio. The logistic regression, random forest, and extreme gradient boosting were applied to construct models in the derivation cohort with 5-fold cross validation. The validation cohort accessed the model performance. The area under the curves measured the model discrimination, while the Spiegelhalter z test evaluated the model calibration.ResultsA total of 1085 patients were included, and 760 were assigned to the derivation cohort. 8.4% and 8.0% of patients experienced postoperative cardiopulmonary complications in the two cohorts. All baseline characteristics were balanced. The values of the area under the curve were 0.728, 0.721, and 0.767 for the logistic, random forest and extreme gradient boosting models, respectively. No significant differences existed among them. They all showed good calibration (p > 0.05). The logistic model consisted of male, arrhythmia, cerebrovascular disease, the percentage of predicted postoperative forced expiratory volume in one second, and the ratio of forced expiratory volume in one second to forced vital capacity. The last two variables, the percentage of forced vital capacity and age ranked in the top five important variables for novel machine learning models. A nomogram was plotted for the logistic model.ConclusionThree models were developed and validated for predicting postoperative cardiopulmonary complications among Chinese patients with lung cancer. They all exerted good discrimination and calibration. The percentage of predicted postoperative forced expiratory volume in one second and the ratio of forced expiratory volume in one second to forced vital capacity might be the most important variables. Further validation in different scenarios is still warranted.

Factors Affecting Postoperative Lung Functions in Patients Undergoing Lobectomy for Non-Small Cell Lung Cancer.

Background and Objectives: The estimation of lung function impairment after pulmonary lobectomy for primary non-small cell lung cancer (NSCLC) has been of great interest since the reduction of respiratory function might severely affect a patient’s quality of life. The perioperative factors that may have an influence on widening the gap between the postoperative measured lung function and predicted postoperative lung function were our greatest concern. We aimed to analyze the perioperative patient factors that may influence postoperative lung function in patients undergoing pulmonary lobectomy. Materials and Methods: A retrospective study was conducted using the medical records of 199 patients who underwent lobectomy for lung cancer between July 2017 and May 2020. After comparing the achieved postoperative forced expiratory volume in 1 s (FEV1) and predicted postoperative (ppo) FEV1, patients were divided into two groups: group A (n = 127), who had preserved pulmonary lung function; and group B (n = 72), who had decreased pulmonary lung function. Primary endpoints included location of pulmonary resection, preoperative performance status, body mass index (BMI) on admission, total muscle area, and muscle index. Results In group A, the proportion of normal weighted patients was significantly higher than that in group B (67.7% vs. 47.2%, p = 0.003). Conversely, the proportion of overweight patients was significantly higher in group B than in group A (47.2% vs. 28.3%, p = 0.003). Group B had a significantly high incidence of upper lobe resection (p = 0.012). The mean total muscle area in group A was higher than that in group B, but the difference was not statistically significant. Conclusions: A greater decrease in postoperative lung function than in ppo FEV1 was associated with BMI and the location of pulmonary resection in patients who underwent lobectomy. Postoperative physiologic changes due to high BMI and the resection of upper lobes need to be discussed to prevent postoperative morbidities.

Resting Physiologic Dead Space as Predictor of Postoperative Pulmonary Complications After Robotic-Assisted Lung Resection: A Pilot Study.

Lung resection surgery carries significant risks of postoperative pulmonary complications (PPC). Cardiopulmonary exercise testing (CPET) is performed to predict risk of PPC in patients with severely reduced predicted postoperative forced expiratory volume in one second (FEV1) and diffusion of carbon monoxide (DLCO). Recently, resting end-tidal partial pressure of carbon dioxide (PETCO2) has been shown as a good predictor for increased risk of PPC. However, breath-breath breathing pattern significantly affects PETCO2. Resting physiologic dead space (VD), and physiologic dead space to tidal volume ratio (VD/VT), may be a better predictor of PPC than PETCO2. The objective of this study was to prospectively determine the utility of resting measurements of VD and VD/VT in predicting PPC in patients who underwent robotic-assisted lung resection for suspected or biopsy-proven lung malignancy. Thirty-five consecutive patients were included in the study. Patients underwent preoperative pulmonary function testing, symptom-limited CPET, and a 6-min walk test. In the first 2 min prior to the exercise portion of the CPET, we obtained resting VT, minute ventilation (E), VD (less instrument dead space), VD/VT, PETCO2, and arterial blood gases. PPC within 90 days were recorded. Fourteen (40%) patients had one or more PPC. Patients with PPC had significantly elevated resting VD compared to those without (0.318 ± 0.028 L vs. 0.230 ± 0.017 L (± SE), p < 0.006), and a trend toward increased VD/VT (0.35 ± 0.02 vs. 0.31 ± 0.02, p = 0.051). Area under the receiver operating characteristic (ROC) for VD was 0.81 (p < 0.002), VD/VT was 0.68 (p = 0.077), and PETCO2 was 0.52 (p = 0.840). Peak O2, E/ CO2 slope, pulmonary function tests, 6-min walk distance and arterial blood gases were similar between the two groups. Intensive care unit and total hospital length of stay was significantly longer in those with PPC. In conclusion, preoperative resting VD was significantly elevated in patients with PPC. The observed increase in resting VD may be a potentially useful predictor of PPC in patients undergoing robotic-assisted lung resection surgery for suspected or biopsy-proven lung malignancy. A large prospective study is needed for confirmation.