Long-term pulmonary function after lobectomy for primary lung cancer

Compensatory function change by segment-counting method in predicted postoperative pulmonary function at 1 year after surgery: systematic review and meta-analysis

BACKGROUND

This systematic review aimed to assess the accuracy of the segment-counting method in predicting long-term pulmonary function recovery and investigate compensatory changes following different extents of lung resection.

METHODS

We included studies that measured forced expiratory volume at 1 s (FEV1) between 6 and 18 months postoperatively, comparing it to the predicted postoperative FEV1 (ppoFEV1) using the segment-counting method. The extent of lung resection was correlated with the ratio of postoperative FEV1 to ppoFEV1. A comprehensive search was conducted in Embase, MEDLINE and Web of Science using terms related to 'lung resection' and 'pulmonary function'. The final search was completed on 18 February 2022. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

39 studies comprising 78 observation cohorts met the inclusion criteria. The analysis showed significant differences in pulmonary function in patients with ≥3 resected segments. Meta-regression indicated that the number of resected segments significantly impacted the postoperative FEV1/ppoFEV1 ratio, explaining 57% of the variance (R²=0. 57), with moderate heterogeneity (I²=61. 87%) across studies. Other variables, including patient age, body mass index, video-assisted thoracoscopic surgery use and tumour stage, did not show significant effects.

DISCUSSION

Limitations of the review included moderate heterogeneity between studies and potential selection bias related to the stage of cancer and lung volume reduction effects. The findings suggest that the extent of lung resection correlates with better-than-expected pulmonary function, potentially due to compensatory mechanisms.

PROSPERO REGISTRATION NUMBER

This review was registered on PROSPERO (CRD42021293608).

Association of high PM2.5 levels with short-term and medium-term lung function recovery in patients with pulmonary lobectomy

The association between exposure to ambient fine particulate matter with an aerodynamic diameter of ≤ 2.5 μm (PM_2.5) and short- and medium-term lung function recovery (LFR) in patients undergoing lobectomy remains uncertain. This study investigated the associations between PM_2.5 concentrations and LFR in adult patients (n = 526) who underwent video-assisted thoracoscopic (VATS) lobectomy in Guangzhou, China between January 2018 and June 2021. All patients underwent at least two spirometry tests. Environmental PM_2.5 concentrations in the same period were collected from the nearest monitoring station. A multiple linear regression (MLR) model was employed to investigate the associations between changes in PM_2.5 concentrations and LFR in patients who underwent lobectomy after adjusting for potential confounders. We assessed short- and medium-term LFR in patients who underwent lobectomy. The three- and 6-month average PM_2.5 concentrations in each patient's residential area were divided into regional mild pollution (PM_2.5 <25 μg/m³), moderate pollution (25 μg/m³ ≤ PM_2.5 <35 μg/m³), and severe pollution (35 μg/m³ ≤ PM_2.5) periods. The MLR model confirmed that PM_2.5 was an independent risk factor affecting short-term forced lung capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximum expiratory flow at 50% vital capacity (MEF₅₀) recovery (adjusted P = 0.041, 0.014, 0.016, respectively). The MLR model confirmed that PM_2.5 was an independent risk factor affecting medium-term MEF₅₀ recovery (adjusted P = 0.046). Compared with the moderate and severe pollution periods, the short- and medium-term LFR (FVC, FEV1, MEF₅₀) of patients in the mild pollution period were faster and better (P < 0.001, P < 0.001, P < 0.001, P = 0.048, P = 0.010, P = 0.013, respectively). Thus, exposure to high PM_2.5 levels was associated with significantly reduced speed and degree of short- and medium-term LFR in patients who underwent lobectomy.

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.

Changes in Forced Expiratory Volume in 1 Second after Anatomical Lung Resection according to the Number of Segments

Background

Although various methods are already used to calculate predicted postoperative forced expiratory volume in 1 second (FEV₁) based on preoperative FEV₁ in lung surgery, the predicted postoperative FEV₁ is not always the same as the actual postoperative FEV₁. Observed postoperative FEV₁ values are usually the same or higher than the predicted postoperative FEV₁. To overcome this issue, we investigated the relationship between the number of resected lung segments and the discordance of preoperative and postoperative FEV₁ values.

Methods

From September 2014 to May 2020, the data of all patients who underwent anatomical lung resection by video-assisted thoracoscopic surgery (VATS) were gathered and analyzed retrospectively. We investigated the association between the number of resected segments and the differential FEV₁ (a measure of the discrepancy between the predicted and observed postoperative FEV₁) using the t-test and linear regression.

Results

Information on 238 patients who underwent VATS anatomical lung resection at Kyung Hee University Hospital at Gangdong and by DH. Kim for benign and malignant disease was collected. After applying the exclusion criteria, 114 patients were included in the final analysis. In the multiple linear regression model, the number of resected segments showed a positive correlation with the differential FEV₁ (Pearson r=0.384, p<0.001). After adjusting for multiple covariates, the differential FEV₁ increased by 0.048 (95% confidence interval, 0.023–0.073) with an increasing number of resected lung segments (R²=0.271, p<0.001).

Conclusion

In this study, after pulmonary resection, the number of resected segments showed a positive correlation with the differential FEV₁.

Pulmonary function after segmentectomy versus lobectomy in patients with early-stage non-small-cell lung cancer: a meta-analysis

Objective

Segmentectomy is widely performed for early-stage lung cancer. However, the effects of segmentectomy versus lobectomy on pulmonary function remain unclear. We performed a meta-analysis with the aim of comparing segmentectomy and lobectomy in terms of preservation of pulmonary function in patients with early-stage non-small-cell lung cancer (NSCLC).

Methods

We conducted a literature search of PubMed using the terms ‘pulmonary function’ AND ‘segmentectomy’ AND ‘lobectomy’. The primary outcomes of interest were the forced expiratory volume in 1 second (FEV1), FEV1 as percent of predicted (%FEV1), change in FEV1 (Δ%FEV1), and the ratio of postoperative to preoperative FEV1.

Results

Thirteen studies comprising 2027 patients met the inclusion and exclusion criteria and were included for analysis, including 787 patients in the segmentectomy group and 1240 patients in the lobectomy group. Patients in the segmentectomy group showed significantly better preservation of FEV1 and %FEV1 compared with the lobectomy group. The reduction in FEV1 after surgery was significantly less in the segmentectomy group compared with the lobectomy group, and Δ%FEV1 was significantly higher in the segmentectomy group than in the lobectomy group.

Conclusion

Segmentectomy results in better preservation of pulmonary function compared with lobectomy in patients with early-stage NSCLC.

Factors and potential treatments of cough after pulmonary resection: A systematic review

Cough is a common complication following pulmonary resection. Persistent and severe cough after pulmonary resection can cause significant impairments in quality of life among postoperative patients. Complications of cough can be life-threatening. To improve patients' probability and quality of life, factors that induce cough after pulmonary resection (CAP) and potential treatments should be explored and summarized. Previous studies have identified various factors related to CAP. However, those factors have not been categorized and analyzed in a sensible manner. Here, we summarized the different factors and classified them into four groups. Potential therapies might be developed to selectively target different factors that affect CAP. However, the exact mechanism underlying CAP remains unknown, making it difficult to treat and manage CAP. In this review, we summarized the latest studies in our understanding of the factors related to CAP and potential treatments targeting those factors. This review can help understand the mechanism of CAP and develop efficient therapies and management.

Structural and functional alterations of the tracheobronchial tree after left upper pulmonary lobectomy for lung cancer

Background

Pulmonary lobectomy has been a well-established curative treatment method for localized lung cancer. After left upper pulmonary lobectomy, the upward displacement of remaining lower lobe causes the distortion or kink of bronchus, which is associated with intractable cough and breathless. However, the quantitative study on structural and functional alterations of the tracheobronchial tree after lobectomy has not been reported. We sought to investigate these alterations using CT imaging analysis and computational fluid dynamics (CFD) method.

Methods

Both preoperative and postoperative CT images of 18 patients who underwent left upper pulmonary lobectomy are collected. After the tracheobronchial tree models are extracted, the angles between trachea and bronchi, the surface area and volume of the tree, and the cross-sectional area of left lower lobar bronchus are investigated. CFD method is further used to describe the airflow characteristics by the wall pressure, airflow velocity, lobar flow rate, etc.

Results

It is found that the angle between the trachea and the right main bronchus increases after operation, but the angle with the left main bronchus decreases. No significant alteration is observed for the surface area or volume of the tree between pre-operation and post-operation. After left upper pulmonary lobectomy, the cross-sectional area of left lower lobar bronchus is reduced for most of the patients (15/18) by 15–75%, especially for 4 patients by more than 50%. The wall pressure, airflow velocity and pressure drop significantly increase after the operation. The flow rate to the right lung increases significantly by 2–30% (but there is no significant difference between each lobe), and the flow rate to the left lung drops accordingly. Many vortices are found in various places with severe distortions.

Conclusions

The favorable and unfavorable adaptive alterations of tracheobronchial tree will occur after left upper pulmonary lobectomy, and these alterations can be clarified through CT imaging and CFD analysis. The severe distortions at left lower lobar bronchus might exacerbate postoperative shortness of breath.

[Difference of Lung Function Retention after Segmentectomy and Lobectomy]

近年来肺癌发病率和检出率逐渐升高，肺段切除术被越来越普遍应用于治疗早期非小细胞肺癌。有学者认为肺段切除术相比肺叶切除术更有利于术后肺功能的保留，也有研究得出两种手术方式在术后肺功能保留方面差异不大，本文就肺段切除术与肺叶切除术术后肺功能变化的相关研究作一综述。

Lung function in the late postoperative phase and influencing factors in patients undergoing pulmonary lobectomy

BACKGROUND

Lung function in the late postoperative phase after pulmonary lobectomy is insufficiently characterized. This study aimed to appraise lung function in the late postoperative phase according to vital capacity (VC) and forced expiratory volume in 1 second (FEV1) in patients who underwent pulmonary lobectomy.

METHODS

Pre- and postoperative VC and FEV1 were reviewed in 112 patients who underwent pulmonary lobectomy. Postoperative lung volume was assessed >1 year after surgery. Postoperative decreases in VC and FEV1 were compared with preoperative predicted values among patients who underwent resection of specific lobe. Determinants effecting a decrease in lung function were also investigated.

RESULTS

A mean postoperative decreased VC of 10.5%±1.8% was recorded in patients who underwent right upper lobectomy (RU), 7.2%±1.5% for right middle lobectomy (RM), 14.3%±2.3% for right lower lobectomy (RL), 16.6%±3.0% for left upper lobectomy (LU), and 14.7%±2.5% for left lower lobectomy (LL). Corresponding FEV1 values were 14.8%±1.8% for RU, 11.9%±4.0% for RM, 14.9%±2.3% for RL, 17.9%±2.9% for LU, and 15.1%±2.4% for LL. The actual decreasing rate of VC was overestimated in patients who underwent RU, RL, LU, and LL. In contrast, FEV1 was overestimated only in patients who underwent RL and LL. Patients with chronic obstructive pulmonary disease (COPD) exhibited significantly better preservation of FEV1.

CONCLUSIONS

Patients scheduled for RL and LL, or those with COPD, appeared to exhibit preserved lung function in the late postoperative phase after pulmonary lobectomy.

Predictors of long-term compensatory response of pulmonary function following major lung resection for non-small cell lung cancer

BACKGROUND AND OBJECTIVE

Long-term pulmonary function which might include compensatory response (CR) significantly influences quality of life of long-term survivor after major lung resection. We investigated long-term pulmonary function after major lung resection.

METHODS

A total of 137 patients who had undergone lobar resection for non-small cell lung cancer (NSCLC) from May 2013 to June 2014 had spirometry at 10-14 months after surgery. Actual post-operative forced expiratory volume in 1 s (FEV₁ ) (FEV_1apo )/predicted post-operative FEV₁ (FEV_1ppo ), actual post-operative forced vital capacity (FVC) (FVC_apo )/predicted post-operative FVC (FVC_ppo ), its relationship with clinicopathological factors and immunohistochemistry for pro-surfactant protein C (pro-SPC), thyroid transcription factor-1 (TTF-1) and vascular endothelial growth factor receptor 2 (VEGFR2) were investigated.

RESULTS

FEV_1apo /FEV_1ppo showed strong correlation with FVC_apo /FVC_ppo (r = 0.628; P < 0.001). We defined greater CR as both FEV_1apo /FEV_1ppo and FVC_apo /FVC_ppo were >120%. Greater CR was significantly associated with decreased smoking index (P < 0.001) and greater resected subsegments (P = 0.037). The never-smoker group revealed significantly greater CR compared with the smoker group in both FEV_1apo /FEV_1ppo (119.9 ± 12.5% vs 107.5 ± 14.2%; P = 0.030) and FVC_apo /FVC_ppo (117.9 ± 9.98% vs 107.2 ± 13.1%; P = 0.046) in case-matched comparison. The expression of pro-SPC, TTF-1 and VEGFR2 in the normal lung parenchyma of greater CR group was significantly higher than those of lesser CR group (P < 0.001 for each). In addition, pro-SPC, TTF-1 and VEGFR2 expressions showed a significant correlation to the degree of CR especially in the smoker group (r = 0.631, 0.705 and 0.732, respectively; P < 0.001 for each).

CONCLUSION

Our data suggest that smokers may develop lesser long-term CR after major lung resection. Decreased expression of pro-SPC, TTF-1 and VEGFR2 may indicate decreased capacity of CR, especially in patients who smoke.

Efficacy of Systemic Postoperative Pulmonary Rehabilitation After Lung Resection Surgery

OBJECTIVE

To investigate the efficacy of systemic pulmonary rehabilitation (PR) after lung resection in patients with lung cancer.

METHODS

Forty-one patients undergoing lung resection were enrolled and classified into the experimental (n=31) and control groups (n=10). The experimental group underwent post-operative systemic PR which was conducted 30 min/day on every hospitalization day by an expert physical therapist. The control group received the same education about the PR exercises and were encouraged to self-exercise without supervision of the physical therapist. The PR group was taught a self-PR program and feedback was provided regularly until 6 months after surgery. We conducted pulmonary function testing (PFT) and used a visual analog scale (VAS) to evaluate pain, and the modified Borg Dyspnea Scale (mBS) to measure perceived respiratory exertion shortly before and 2 weeks, 1, 3, and 6 months after surgery.

RESULTS

A significant improvement on the VAS was observed in patients who received systemic PR >3 months. Significant improvements in forced vital capacity (FVC) and mBS score were observed in patients who received systemic PR >6 months (p<0.05). Other PFT results were not different compared with those in the control group.

CONCLUSION

Patients who received lung resection suffered a significant decline in functional reserve and increases in pain and subjective dyspnea deteriorating quality of life (QoL). Systemic PR supervised by a therapist helped improve reduced pulmonary FVC and QoL and minimized discomfort during the postoperative periods in patients who underwent lung resection.

Physiologic evaluation of lung resection candidates

This article reviews an evidence-based approach to the physiologic evaluation of patients under consideration for surgical resection of lung cancer. Adequate physiologic evaluation often includes a multidisciplinary evaluation, with complete identification of risk factors for perioperative complications and long-term disability including cardiovascular risk, assessment of pulmonary function, and smoking cessation counseling. Consideration of tumor-related anatomic obstruction, atelectasis, or vascular occlusion may alter measurements. Careful preoperative physiologic assessment helps to identify patients at increased risk of morbidity and mortality after lung resection. These evaluations are helpful in identifying patients who may not benefit from surgical management of their lung cancer.

Acid regurgitation associated with persistent cough after pulmonary resection: an observational study

BACKGROUND

Following a pulmonary resection, some patients suffer from persistent coughing, which may have a relationship with acid regurgitation. Since few physiological studies have been reported regarding this issue, we conducted the present observational study.

METHODS

Persistent cough after pulmonary resection (CAP) was defined as non-productive coughing that occurred after a pulmonary resection in patients with stable chest X-ray results and no postnasal drip syndrome, asthma, or history of angiotensin converting enzyme inhibitor administration. A 24-hour esophageal pH monitor was used with patients with coughing (n = 13) and patients with no coughing (n = 4) after undergoing a lobectomy, and the relationship between acid regurgitation and CAP was assessed using symptom association probability.

RESULTS

Based on the results of pH monitoring conducted within 4 weeks of the operation we divided the patients into 3 groups: Type A had frequent gastroesophageal refluxes (>50 occurrences in 24 hours) and frequent coughing (>30 occurrences in 24 hours), Type B had frequent gastroesophageal refluxes and infrequent coughing, and type C had infrequent gastroesophageal refluxes and infrequent coughing. Type A patients (n = 10) were exclusively those with CAP and the symptom association probability was greater than 95%. Five from that group underwent esophageal pH monitoring more than 1 year after surgery and none showed significant improvements in acid regurgitation.

CONCLUSION

There was a relationship seen between acid regurgitation and CAP in some patients shortly after surgery, while acid regurgitation remained unimproved after improvement of coughing in most of those 1 year after surgery.

Fall in Diffusing Capacity Associated With Induction Therapy for Lung Cancer: A Predictor of Postoperative Complication?

BACKGROUND

Pulmonary resection after induction therapy is associated with high rates of pulmonary morbidity and mortality. However, the impact of induction therapy on the pulmonary toxicity and associated pulmonary complications has not been fully investigated in the setting of lung cancer surgery.

METHODS

We assessed the 66 consecutive patients who underwent a pulmonary resection after induction therapy, 48 of whom received chemoradiotherapy and 18, chemotherapy alone. Results of pulmonary function before and after induction therapy were compared, and logistic regression analyses utilized to explore the risk factors of pulmonary morbidity.

RESULTS

After induction therapy, forced expiratory volume in 1 second (FEV1) was increased significantly (from 2.28 +/- 0.61 L to 2.40 +/- 0.62 L; p < 0.05); however, percent vital capacity (%VC) and FEV1/FVC did not change significantly. The diffusing capacity of lung for carbon monoxide (D(LCO)) was decreased significantly by 21% (from 90.3% +/- 18.3% to 71.1% +/- 12.5%; p < 0.0005). Patients with respiratory complication showed lower predicted postoperative %FEV1 (49.5% +/- 11.1% versus 57.2% +/- 14.2%; p = 0.031) and predicted postoperative %Dlco (41.9% +/- 8.0% versus 55.4% +/- 10.1%; p < 0.0001) results than those without complications. Univariate and multivariate analyses revealed that predicted postoperative %D(LCO) alone was an independent factor to predict postoperative pulmonary morbidity.

CONCLUSIONS

For patients who undergo a pulmonary resection after induction therapy, predicted postoperative %D(LCO) is more important to predict pulmonary morbidity rather than static pulmonary function (predicted postoperative %VC or %FEV1). The decrease in D(LCO) is thought to reflect a limited gas exchange reserve, caused by the potential toxicity of chemotherapy or chemoradiotherapy. We believe that the impact of diffusion limitation after induction therapy should to be emphasized to decrease the pulmonary morbidity.