Outcome after video-assisted thoracoscopic surgery and open pulmonary lobectomy in patients with low VO2 max: a case-matched analysis from the ESTS database†

Cardiorespiratory fitness and morbidity and mortality in patients with non-small cell lung cancer: a prospective study with propensity score weighting

INTRODUCTION

This study aimed to investigate the association between cardiorespiratory fitness (CRF) and perioperative morbidity and long-term mortality in operable patients with early-stage non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

This prospective study included consecutive patients with early-stage NSCLC who underwent presurgical cardiopulmonary exercise testing between November 2014 and December 2019 (registration number: ChiCTR2100048120). Logistic and Cox proportional hazards regression were applied to evaluate the correlation between CRF and perioperative complications and long-term mortality, respectively. Propensity score overlap weighting was used to adjust for the covariates. We performed sensitivity analyses to determine the stability of our results.

RESULTS

A total of 895 patients were followed for a median of 40 months [interquartile range 25]. The median age of the patients was 59 years [range 26-83], and 62.5% were male. During the study period, 156 perioperative complications and 146 deaths were observed. Low CRF was associated with a higher risk of death (62.9 versus 33.6 per 1000 person-years; weighted incidence rate difference, 29.34 [95% CI, 0.32 to 58.36] per 1000 person-years) and perioperative morbidity (241.6 versus 141.9 per 1000 surgeries; weighted incidence rate difference, 99.72 [95% CI, 34.75 to 164.70] per 1000 surgeries). A CRF of ≤ 20 ml/kg/min was significantly associated with a high risk of long-term mortality (weighted hazard ratio, 1.98 [95% CI, 1.31 to 2.98], p < 0.001) and perioperative morbidity (weighted odds ratio, 1.93 [1.28 to 2.90], p = 0.002) compared to higher CRF.

CONCLUSION

The study found that low CRF is significantly associated with increased perioperative morbidity and long-term mortality in operable patients with early-stage NSCLC.

The association between cardiopulmonary exercise testing and postoperative outcomes in patients with lung cancer undergoing lung resection surgery: A systematic review and meta-analysis

BACKGROUND

Exercise capacity should be determined in all patients undergoing lung resection for lung cancer surgery and cardiopulmonary exercise testing (CPET) remains the gold standard. The purpose of this study was to investigate associations between preoperative CPET and postoperative outcomes in patients undergoing lung resection surgery for lung cancer through a review of the existing literature.

METHODS

A search was conducted on PubMed, Scopus, Cochrane Library and CINAHL from inception until December 2022. Studies investigating associations between preoperative CPET and postoperative outcomes were included. Risk of bias was assessed using the QUIPS tool. A random effect model meta-analysis was performed. I2 > 40% indicated a high level of heterogeneity.

RESULTS

Thirty-seven studies were included with 6450 patients. Twenty-eight studies had low risk of bias. [Formula: see text] peak is the oxygen consumption at peak exercise and serves as a marker of cardiopulmonary fitness. Higher estimates of [Formula: see text] peak, measured and as a percentagege of predicted, showed significant associations with a lower risk of mortality [MD: 3.66, 95% CI: 0.88; 6.43 and MD: 16.49, 95% CI: 6.92; 26.07] and fewer complications [MD: 2.06, 95% CI: 1.12; 3.00 and MD: 9.82, 95% CI: 5.88; 13.76]. Using a previously defined cutoff value of > 15mL/kg/min for [Formula: see text] peak, showed evidence of decreased odds of mortality [OR: 0.55, 95% CI: 0.28-0.81] and but not decreased odds of postoperative morbidity [OR: 0.82, 95% CI: 0.64-1.00]. There was no relationship between [Formula: see text] slope, which depicts ventilatory efficiency, with mortality [MD: -9.60, 95% CI: -27.74; 8.54] however, patients without postoperative complications had a lower preoperative [Formula: see text] [MD: -2.36, 95% CI: -3.01; -1.71]. Exercise load and anaerobic threshold did not correlate with morbidity or mortality. There was significant heterogeneity between studies.

CONCLUSIONS

Estimates of cardiopulmonary fitness as evidenced by higher [Formula: see text] peak, measured and as a percentage of predicted, were associated with decreased morbidity and mortality. A cutoff value of [Formula: see text] peak > 15mL/kg/min was consistent with improved survival but not with fewer complications. Ventilatory efficiency was associated with decreased postoperative morbidity but not with improved survival. The heterogeneity in literature could be remedied with large scale, prospective, blinded, standardised research to improve preoperative risk stratification in patients with lung cancer scheduled for lung resection surgery.

A New Index for the Quantitative Evaluation of Surgical Invasiveness Based on Perioperative Patients' Behavior Patterns: Machine Learning Approach Using Triaxial Acceleration

BACKGROUND

The minimally invasive nature of thoracoscopic surgery is well recognized; however, the absence of a reliable evaluation method remains challenging. We hypothesized that the postoperative recovery speed is closely linked to surgical invasiveness, where recovery signifies the patient's behavior transition back to their preoperative state during the perioperative period.

OBJECTIVE

This study aims to determine whether machine learning using triaxial acceleration data can effectively capture perioperative behavior changes and establish a quantitative index for quantifying variations in surgical invasiveness.

METHODS

We trained 7 distinct machine learning models using a publicly available human acceleration data set as supervised data. The 3 top-performing models were selected to predict patient actions, as determined by the Matthews correlation coefficient scores. Two patients who underwent different levels of invasive thoracoscopic surgery were selected as participants. Acceleration data were collected via chest sensors for 8 hours during the preoperative and postoperative hospitalization days. These data were categorized into 4 actions (walking, standing, sitting, and lying down) using the selected models. The actions predicted by the model with intermediate results were adopted as the actions of the participants. The daily appearance probability was calculated for each action. The 2 differences between 2 appearance probabilities (sitting vs standing and lying down vs walking) were calculated using 2 coordinates on the x- and y-axes. A 2D vector composed of coordinate values was defined as the index of behavior pattern (iBP) for the day. All daily iBPs were graphed, and the enclosed area and distance between points were calculated and compared between participants to assess the relationship between changes in the indices and invasiveness.

RESULTS

Patients 1 and 2 underwent lung lobectomy and incisional tumor biopsy, respectively. The selected predictive model was a light-gradient boosting model (mean Matthews correlation coefficient 0.98, SD 0.0027; accuracy: 0.98). The acceleration data yielded 548,466 points for patient 1 and 466,407 points for patient 2. The iBPs of patient 1 were [(0.32, 0.19), (-0.098, 0.46), (-0.15, 0.13), (-0.049, 0.22)] and those of patient 2 were [(0.55, 0.30), (0.77, 0.21), (0.60, 0.25), (0.61, 0.31)]. The enclosed areas were 0.077 and 0.0036 for patients 1 and 2, respectively. Notably, the distances for patient 1 were greater than those for patient 2 ({0.44, 0.46, 0.37, 0.26} vs {0.23, 0.0065, 0.059}; P=.03 [Mann-Whitney U test]).

CONCLUSIONS

The selected machine learning model effectively predicted the actions of the surgical patients with high accuracy. The temporal distribution of action times revealed changes in behavior patterns during the perioperative phase. The proposed index may facilitate the recognition and visualization of perioperative changes in patients and differences in surgical invasiveness.

Intraoperative ventilatory leak: Real-time guidance for management of air leak in lung cancer patients undergoing VATS lobectomy

BACKGROUND

Persistent air leak (PAL) is a common complication after video-assisted thoracoscopic surgery (VATS) lobectomy. We aimed to evaluate whether the intraoperative quantitative measurement of air leaks using a mechanical ventilation test could predict PAL and identify those patients needing additional treatment for the prevention of PAL.

METHODS

This was an observational, retrospective, single-center study that included 82 patients who underwent VATS lobectomy with a mechanical ventilation test for VL. Only 2% of patients who underwent lobectomy surgery had persistent air leaks.

RESULTS

At the end of lobectomy performed in patients with non-small cell lung cancer, the lung was reinflated at a 25-30 mmH2O pressure and ventilatory leaks (VL) were calculated and in relation to the entity of the air leaks, we evaluated the most suitable intraoperative treatment to prevent persistent air leaks.

CONCLUSION

VL is an independent predictor of PAL after VATS lobectomy; it provides a real-time intraoperative guidance to identify those patients who can benefit from additional intraoperative preventive interventions to reduce PAL.

Early outcomes of “low-risk” patients undergoing lung resection assessed by cardiopulmonary exercise testing: Single-institution experience

Objective

Cardiopulmonary exercise testing (CPET) is currently recommended for all patients undergoing lung resection with either respiratory comorbidities or functional limitations. The main parameter evaluated is oxygen consumption at peak (VO2peak). Patients with VO2peak above 20 ml/kg/min are classified as low risk surgical candidates. The aims of this study were to evaluate postoperative outcomes of low-risk patients, and to compare their outcomes with those of patients without pulmonary impairment at respiratory function testing.

Methods

Retrospective monocentric observational study was designed, evaluating outcomes of patients undergoing lung resection at San Paolo University Hospital, Milan, Italy, between January 2016 and November 2021, preoperatively assessed by CPET, according to 2009 ERS/ESTS guidelines. All low-risk patients undergoing any extent surgical lung resection for pulmonary nodules were enrolled. Postoperative major cardiopulmonary complications or death, occurring within 30 days from surgery, were assessed. A case-control study was nested, matching 1:1 for type of surgery the cohort population with control patients without functional respiratory impairment consecutively undergoing surgery at the same centre in the study period.

Results

A total of 80 patients were enrolled: 40 subjects were preoperatively assessed by CPET and deemed at low risk, whereas 40 subjects represented the control group. Among the first, 4 patients (10%) developed major cardiopulmonary complications, and 1 patient (2.5%) died within 30 days from surgery. In the control group, 2 patients (5%) developed complications and none of the patients (0%) died. The differences in morbidity and mortality rates did not reach statistically significance. Instead, age, weight, BMI, smoking history, COPD incidence, surgical approach, FEV1, Tiffenau, DLCO and length of hospital stay resulted significantly different between the two groups. At a case-by-case analysis, CPET revealed a pathological pattern in each complicated patient, in spite of VO2peak above target for safe surgery.

Conclusions

Postoperative outcomes of low-risk patients undergoing lung resections are comparable to those of patients without any pulmonary functional impairment; nonetheless the formers represent a dramatically different category of individuals from the latter and may harbour few patients with worse outcomes. CPET variables overall interpretation may add to the VO2peak in identifying higher risk patients, even in this subgroup.

[Predictive model for additional intraoperative placement of chest drainage after thoracoscopic lobectomy]

OBJECTIVE

To create a prognostic model determining the risk of tension pneumothorax and the need for intraoperative installation of additional drainage after thoracoscopic lobectomy.

MATERIAL AND METHODS

A retrospective multiple-center study included patients who underwent thoracoscopic lobectomy for lung cancer between 2016 and 2022. One drainage tube was used after surgery in all cases. We synthesized data to expand patient selection using the Riley method and machine learning algorithm. In total, treatment outcomes in 1458 patients were analyzed. After identifying significant factors, we performed binary logistic regression analysis using backward stepwise inclusion of variables in accordance with the Akaike information criterion. After validating the model using the Bootstrap method (400 iterations) and original data set, we created a nomogram determining scoring characteristics, linear predictors and risk of postoperative tension pneumothorax.

RESULTS

The incidence of tension pneumothorax was 4.53% (n=66). The most significant variables associated with pneumothorax and the need for additional pleural drainage were adhesions, intraoperative lung suturing, unclear interlobar groove, enlarged intrapulmonary lymph nodes and chronic obstructive pulmonary disease (p<0.001). The model's C-index was 0.957, mean absolute calibration error - 0.6%, calibration curve slope - 0.959. A score of 26 indicated a 95% risk of postoperative pneumothorax.

CONCLUSION

We developed a prognostic model for tension pneumothorax after thoracoscopic lobectomy. Nomogram makes it possible to make a decision on intraoperative installation of additional pleural drainage tube and prevent complications associated with postoperative lung collapse.

Exercise testing and postoperative complications after minimally invasive lung resection: A cohort study

Background: Peak oxygen uptake (V˙O2) during cardiospulmonary exercise testing (CPET) is used to stratify postoperative risk following lung cancer resection but peak V˙O2 thresholds to predict post-operative mortality and morbidity were derived mostly from patients who underwent thoracotomy.

Objectives: We evaluated whether peak V˙O2 or other CPET-derived variables predict post-operative mortality and cardiopulmonary morbidity after minimally invasive video-assisted thoracoscopic surgery (VATS) for lung cancer resection.

Methods: A retrospective analysis of patients who underwent VATS lung resection between 2002 and 2019 and in whom CPET was performed. Logistic regression models were used to determine predictors of postoperative outcomes until 30 days after surgery. The ability of peak V˙O2 to discriminate between patients with and without post-operative complications was evaluated using Receiver operating characteristic (ROC) analysis.

Results: Among the 593 patients, postoperative cardiopulmonary complications occurred in 92 (15.5%) individuals, including three deaths. Mean peak V˙O2 was 18.8 ml⋅kg⁻¹⋅min⁻¹, ranging from 7.0 to 36.4 ml⋅kg⁻¹⋅min⁻¹. Best predictors of postoperative morbidity and mortality were peripheral arterial disease, bilobectomy or pneumonectomy (versus sublobar resection), preoperative FEV₁, peak V˙O2 , and peak V˙E/V˙CO2. The proportion of patients with peak V˙O2 of < 15 ml⋅kg⁻¹⋅min⁻¹, 15 to < 20 ml⋅kg⁻¹⋅min⁻¹ and ≥ 20 ml⋅kg⁻¹⋅min⁻¹ experiencing at least one postoperative complication was 23.8, 16.3 and 10.4%, respectively. The area under the ROC curve for peak V˙O2 was 0.63 (95% CI: 0.57–0.69).

Conclusion: Although lower peak V˙O2 was a predictor of postoperative complications following VATS lung cancer resection, its ability to discriminate patients with or without complications was limited.

Ventilatory efficiency is superior to peak oxygen uptake for prediction of lung resection cardiovascular complications

Introduction

Ventilatory efficiency (V_E/VCO₂ slope) has been shown superior to peak oxygen consumption (VO₂) for prediction of post-operative pulmonary complications in patients undergoing thoracotomy. V_E/VCO₂ slope is determined by ventilatory drive and ventilation/perfusion mismatch whereas VO₂ is related to cardiac output and arteriovenous oxygen difference. We hypothesized pre-operative VO₂ predicts post-operative cardiovascular complications in patients undergoing lung resection.

Methods

Lung resection candidates from a published study were evaluated by post-hoc analysis. All of the patients underwent preoperative cardiopulmonary exercise testing. Post-operative cardiovascular complications were assessed during the first 30 post-operative days or hospital stay. One-way analysis of variance or the Kruskal–Wallis test, and multivariate logistic regression were used for statistical analysis and data summarized as median (IQR).

Results

Of 353 subjects, 30 (9%) developed pulmonary complications only (excluded from further analysis), while 78 subjects (22%) developed cardiovascular complications and were divided into two groups for analysis: cardiovascular only (n = 49) and cardiovascular with pulmonary complications (n = 29). Compared to patients without complications (n = 245), peak VO₂ was significantly lower in the cardiovascular with pulmonary complications group [19.9 ml/kg/min (16.5–25) vs. 16.3 ml/kg/min (15–20.3); P<0.01] but not in the cardiovascular only complications group [19.9 ml/kg/min (16.5–25) vs 19.0 ml/kg/min (16–23.1); P = 0.18]. In contrast, V_E/VCO₂ slope was significantly higher in both cardiovascular only [29 (25–33) vs. 31 (27–37); P = 0.05] and cardiovascular with pulmonary complication groups [29 (25–33) vs. 37 (34–42); P<0.01)]. Logistic regression analysis showed V_E/VCO₂ slope [OR = 1.06; 95%CI (1.01–1.11); P = 0.01; AUC = 0.74], but not peak VO₂ to be independently associated with post-operative cardiovascular complications.

Conclusion

V_E/VCO₂ slope is superior to peak VO₂ for prediction of post-operative cardiovascular complications in lung resection candidates.

Clinical Efficacy of Different Thoracoscopic Surgeries for Patients With Non-small Cell Lung Cancer

Background

The aim of this study was to analyze the clinical efficacy of different thoracoscopic procedures in patients with non-small cell lung cancer and their correlation with matrix metalloproteinase-7 mRNA (MMPs-7 mRNA) and soluble major histocompatibility complex class I molecule A (sMICA), as well as their effect on T-cell subsets.

Methods

A total of 100 patients with non-small cell lung cancer who received different thoracoscopic surgeries were divided into the Control group (three-port thoracoscopic surgery) and the study group (single-port thoracoscopic surgery). The two groups were evaluated to compare the perioperative indicators, MMPs-7 mRNA, sMICA expression levels, T-cell subsets, postoperative pain, complication rates, and prognostic outcomes at 1-year follow-up.

Results

The operation time, blood loss, drainage tube placement time, incision length, and hospital stay in the study group were less than those in the control group (P < 0.05). There was no significant difference in the number of lymph node dissections between the two groups (P > 0.05). After 3 days, the expression levels of MMPs-7 mRNA and sMICA in the study group were lower than those in the control group (P < 0.05); CD4 +, CD8 +, and CD4 +/CD8 + in the study group were higher than those in the control group (P < 0.05). On days 1, 3, and 5, the visual analog score (VAS) of the study group was lower than that of the control group (P < 0.05); there was no significant difference in the complication rate between the two follow-up groups (P > 0.05), in which all patients completed the follow-up. After 1 year of follow-up, there was no significant difference in the tumor-free survival rate and overall survival rate between the two groups (P > 0.05).

Conclusion

Compared with three-port thoracoscopic surgery, single-port thoracoscopic surgery can improve perioperative expression, shorten hospital stay, reduce serum tumor micrometastasis levels, improve immune metastasis mechanisms and reduce pain, which is of great significance to patients with non-small cell lung cancer. It is an effective, convenient, and safe surgical option that deserves wide clinical reference.

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.

Preoperative Cardiopulmonary Exercise Test Associated with Postoperative Outcomes in Patients Undergoing Cancer Surgery: A Systematic Review and Meta-Analyses

BACKGROUNDS

There is mixed evidence on the value of preoperative cardiorespiratory exercise test (CPET) to predict postoperative outcomes in patients undergoing a cancer surgical procedure. The purpose of this review was to investigate the association between preoperative CPET variables and postoperative complications, length of hospital stay, and quality of life in patients undergoing cancer surgery.

METHODS

A search was conducted on MEDLINE, Embase, AMED, and Web of science from inception to April 2020. Cohort studies investigating the association between preoperative CPET variables, including peak oxygen uptake (peak VO₂), anaerobic threshold (AT), or ventilatory equivalent for carbon dioxide (V_E/V_CO2), and postoperative outcomes (complications, length of stay, and quality of life) were included. Risk of bias was assessed using the QUIPS tool. A random-effect model meta-analysis was performed whenever possible.

RESULTS

Fifty-two unique studies, including 10,030 patients were included. Overall, most studies were rated as having low risk of bias. Higher preoperative peak VO₂ was associated with absence of postoperative complications (mean difference [MD]: 2.28; 95% confidence interval [CI]: 1.26-3.29) and no pulmonary complication (MD: 1.47; 95% CI: 0.49-2.45). Preoperative AT and V_E/V_CO2 also demonstrated some positive trends. None of the included studies reported a negative trend.

CONCLUSIONS

This systematic review and meta-analysis demonstrated a significant association between superior preoperative CPET values, especially peak VO₂, and better postoperative outcomes. The assessment of preoperative functional capacity in patients undergoing cancer surgery has the potential to facilitate treatment decision making.

A risk model to predict 2-year survival after video-assisted thoracoscopic surgery lobectomy for non-small-cell lung cancer

OBJECTIVES

We sought to identify the risk factors associated with mortality post-video-assisted thoracoscopic surgery (VATS) lobectomy over a 2-year period.

METHODS

Analysis was performed using a sample from an institutionally maintained database. All lobectomies for non-small-cell lung cancer from April 2014 to March 2018 started with VATS approach and with a complete follow-up were included (n = 732). Several clinical variables were screened using the Cox univariate analysis for their association with 2-year survival. Those with a P-value <0.1 were included in a Cox proportional hazard model.

RESULTS

After multivariable analysis, the following variables showed significant association with 2-year survival: age >75 [hazard ratio (HR) 1.527, P = 0.043], carbon monoxide lung diffusion capacity <70 (HR 1.474, P = 0.061), body mass index (BMI) <18.5 (HR 2.628, P = 0.012), American Society of Anesthesiologist Physical Status >2 (HR 1.518, P = 0.047), performance status >1 (HR 1.822, P = 0.032) and male gender (HR 2.700, P < 0.001). A score of 2 was assigned to the male gender and BMI <18.5, with all other variables assigned a score of 1. Each patient was scored and placed into their risk class. A Kaplan-Meier estimate for 2-year survival was calculated for each class. These were collapsed into the following 3 classes of risk based on their similar 2-year survival: class A (score 0) 97%, 95% CI 88-99, class B (score 1-3) 84%, 95% CI 80-88, class C (score > 3) 66%, 95% CI 57-74.

CONCLUSION

Our scoring system can serve as an adjunct to a clinician's experience in risk-stratifying patients during multidisciplinary tumour board discussion and the shared decision-making process.

Spiral wire localization of lung nodules: procedure effectiveness and oncological usefulness

Background

In the last years, a large number of techniques and devices for localizing small pulmonary nodules prior to resection have been developed with the aim of facilitating minimally invasive surgery (VATS). However, each device presents pros and cons and there is no unanimous consensus. We report our experience with an uncommon wire system with spiral shape for percutaneous marking.

Methods

We recorded 102 consecutive CT-guided spiral wire localizations in our Institution, and we evaluated the efficacy of the method according to 4 success rates (SR): (I) successful targeting rate (SR-1): number of successful targeting procedures/number of all localizations; (II) successful localization in operative field (SR-2): (number of successful targeting procedures -number of dislodgements in operative field)/number of all localizations; (III) successful VATS rate (SR-3): number of successful VATS procedures/(number of localizations-number of thoracotomies not due to wire dislocation); (IV) successful curative rate (SR-4): number of neoplastic nodules resected with curative intent with free margins (R0) on definitive tissue diagnosis/number of neoplastic nodules resected with curative intent. Complications rate was recorded as well.

Results

SR-1: 100%, SR-2: 97.1%, SR-3: 100%, SR-4: 100%. Asymptomatic pneumothorax and minimal parenchymal hemorrhage were observed in 5 (4.9%) and 19 (18.6%) cases, respectively.

Conclusions

Spiral wire localization showed very good results in terms of feasibility, stability in operative field and contributed to effective use of VATS during wedge resection performed for malignant nodules. In the era of widespread radiological investigations (as it is happening in lung cancer screening) and evolutions in cancer treatments, this appears to be clinically relevant.

Minute ventilation-to-carbon dioxide slope is associated with postoperative survival after anatomical lung resection

OBJECTIVES

The aim of the study was to identify whether ventilation-to-carbon dioxide output (V_E/V _CO2) slope obtained from cardiopulmonary exercise test (CPET) as part of the preoperative functional workup was an independent prognostic factor for short and long-term survival after major lung resection.

PATIENTS AND METHODS

974 consecutive patients undergoing lobectomy (n = 887) or segmentectomy (n = 87) between April 2014 to March 2018 were included. 209 (22%) underwent CPET, and pulmonary function tests and several clinical factors including age, sex, performance status and comorbidities were retrospectively investigated to identify the prognostic factors with a multivariable Cox regression analysis.

RESULTS

Among the patients with measured V_E/V _CO2, the incidence of cardiopulmonary complications in patients with high V_E/V _CO2 slope (>40) was 37% (19 of 51) vs. 27% (33 of 121) in those with lower slope values (p = 0.19). The 90-day mortality in patients with high V_E/V _CO2 slope (n = 8) was 16% vs. 5% (n = 6) in those with lower slope values (p = 0.03). No overall difference in 2-year mortality was identified between the two groups (VE/VCO2 > 40: 70% (54-80) vs. VE/VCO2 ≤ 40: 72% (63-80), log-rank test, p = 0.39). In a Cox regression analysis V_E/V_CO2 values were associated with poorer 2-year survival (HR 1.05, 95% CI 1.01-1.10, p = 0.030).

CONCLUSIONS

We found that V_E/V _CO2 slope was an independent prognostic factor for the 90-day mortality and 2-year survival after anatomic pulmonary resection. This finding may assist during the multidisciplinary treatment decision-making process in high-risk patients with lung cancer.

Cardiopulmonary Exercise Testing and Surgery

The surgical patient population is increasingly elderly and comorbid and poses challenges to perioperative physicians. Accurate preoperative risk stratification is important to direct perioperative care. Reduced aerobic fitness is associated with increased postoperative morbidity and mortality. Cardiopulmonary exercise testing is an integrated and dynamic test that gives an objective measure of aerobic fitness or functional capacity and identifies the cause of exercise intolerance. Cardiopulmonary exercise testing provides an individualized estimate of patient risk that can be used to predict postoperative morbidity and mortality. This technology can therefore be used to inform collaborative decision-making and patient consent, to triage the patient to an appropriate perioperative care environment, to diagnose unexpected comorbidity, to optimize medical comorbidities preoperatively, and to direct individualized preoperative exercise programs. Functional capacity, evaluated as the anaerobic threshold and peak oxygen uptake ([Formula: see text]o₂peak) predicts postoperative morbidity and mortality in the majority of surgical cohort studies. The ventilatory equivalents for carbon dioxide (an index of gas exchange efficiency), is predictive of surgical outcome in some cohorts. Prospective cohort studies are needed to improve the precision of risk estimates for different patient groups and to clarify the best combination of variables to predict outcome. Early data suggest that preoperative exercise training improves fitness, reduces the debilitating effects of neoadjuvant chemotherapy, and may improve clinical outcomes. Further research is required to identify the most effective type of training and the minimum duration required for a positive effect.

Physiopathology aspects of anatomical video-assisted thoracic surgery resections: current status and prospects of development

Pulmonary lobectomy remains the gold standard therapy for early-stage lung cancer. With the spread of video-assisted thoracic surgery (VATS), surgeons began using this approach also to perform lobectomies, becoming progressively widespread worldwide. However some early-stage lung cancer patients are of questionable eligibility for open lobectomy being considered at high-risk to develop postoperative complications due to compromised pulmonary function or cardiopulmonary reserve. Herein we evaluate pathophysiology of VATS, focusing on: the correlation between the traditional predictors of outcome and overall complications, the current status of different VATS approaches and the role of VATS segmentectomy in high-risk patients, unable to tolerate lobectomy for their compromised cardiopulmonary reserve.