Study subjects
The study included a total of 135 patients diagnosed with DL who underwent pneumonectomy at Beijing Chest Hospital, a hospital affiliated with Capital Medical University, from November 2002 to February 2023. Among them, 12 patients who did not undergo preoperative lung function testing were excluded, leaving a total of 123 patients for the analysis. Based on preoperative forced expiratory volume in one second (FEV1) value, patients were sorted into two groups: the FEV1 > 2 L group (30 cases) and the FEV1 ≤ 2 L group (96 cases).
Clinical data were extracted from the hospital’s electronic medical records system. The study design adhered to the principles outlined in the Helsinki Declaration. The requirement for patient written informed consent for participation in the study was waived by the Ethics Committee of the Institutional Review Board of Beijing Chest Hospital, an affiliate of Capital Medical University (Ethics number: Clinical Research 2018 (43)).
Inclusion criteria were as follows: postoperative pathological morphology consistent with TB or inflammation, meeting surgical treatment criteria for DL patients, all of these no sign of respiratory failure, as based on preoperative arterial blood gas analysis.
Exclusion criteria were as follows: bronchial asthma, chronic obstructive pulmonary disease, interstitial lung disease, concurrent malignant tumours, chronic heart failure, chronic renal insufficiency, one or more of these.
Indications of DL patient suitability for pneumonectomy were as follows: lesions located in one lung, life-threatening massive hemoptysis, DL-related recurrent infections, MDR-TB, inability to tolerate anti-TB treatment, repeated positive results of sputum culture and/or smear for M. tuberculosis.
Demographic data included gender, age, body mass index (BMI), smoking history, history of alcohol use, major complications, and common comorbidities (hypertension, coronary heart disease, and diabetes). General clinical data included primary symptoms at admission and duration of the current bout of infection/TB (in months). Infections with MDR-TB, extensively drug-resistant TB (XDR-TB), and chronic aspergillosis were documented.
The modified Medical Research Council dyspnea scale (mMRC) was employed to assess dyspnea severity at time of admission then patients were sorted into two groups based on mMRC score: mMRC = 0 and mMRC ≥ 1. Preoperative auxiliary evaluations included chest CT scans, pulmonary function tests, and routine laboratory tests. Chest CT scan interpretation included the identification of spinal scoliosis and TB cavities within the lesion area. Lung function measurements were conducted using Master Screen-IOS and Master Screen-PFT instruments (Jaeger, Germany). The single-breath diffusion method was employed to determine lung diffusion capacity and predicted lung function values as based on instrument default values endorsed by the European Respiratory Society. Key indicators assessed via lung function testing included forced vital capacity (FVC), FEV1, total lung capacity (TLC), and diffusing capacity of the lungs for carbon monoxide (DLCO).
Surgery-related data included the following: intraoperative blood loss, duration of surgery, left or right lung resection, and performance of pleural stripping. Pneumonectomies were performed as open surgeries.
Short-term postoperative observation-based indicators included death during hospitalisation or within 30 days after discharge, postoperative complications (requiring invasive respiratory support, residual lung infection, heart failure), and median duration of postoperative complications (in days).
Follow-up face-to-face or telephone interviews were administered by a healthcare provider through June 30, 2023 to assess participant survival status, postoperative TB/pulmonary infection recurrence, respiratory function, readmission history, and postoperative treatment. Three patients died during the perioperative period. Of the 120 participants, 26 Of the initial participants (21.7% of 120) became unreachable after three unsuccessful attempts to establish contact via telephone, leading to their classification as lost to follow-up. within the perioperative period, three patients passed away. Subsequently, the follow-up was successfully completed by the remaining 94 patients, with an average age of 39.8 ± 13.6 years. This cohort comprised 28 males and 66 females.
Statistical analysis
Data analysis was conducted using the SPSS 25.0 statistical software package (SPSS Inc., Chicago, IL, USA) and included analysis of both continuous and categorical variables. Normally distributed continuous variables are expressed as mean ± standard deviation, with intergroup comparisons conducted using the t-test. Non-normally distributed continuous variables are expressed as median (25%, 75%) percentile, with intergroup comparisons conducted using the Z-test. Categorical variables are presented as composition ratios or percentages (%), with intergroup comparisons conducted using the chi-square test.
The study aimed to compare short-term mortality and postoperative complications between FEV1 > 2 L and FEV1 ≤ 2 L groups. Additionally, follow-up observations were compared between groups regarding rates of mortality, residual lung reinfection, bronchial stump fistula/empyema, and readmission, as well as postoperative proportions of patients with mMRC ≥ 1.
Binary logistic regression analysis was performed to identify correlations between independent variables (gender, age, current or past smoking status, presence of cavities on chest CT images and the continuous variable FEV
1) and dependent variables related to clinical short- and long-term outcomes. Outcomes variables included rates of postoperative 30-day mortality, incidence of postoperative complications, long-term mortality, residual lung reinfection, TB recurrence, and bronchial stump fistula/empyema, as well as the proportion of patients with mMRC ≥ 1 at follow-up and the postoperative rehospitalisation rate. Clinically relevant statistically significant factors (
P < 0.05) are listed in Table
1.
Table 1
Baseline demographics and clinical characteristics of enrolled patients
Sex, M | 42(34.1) | 18.0(60.0) | 24.0(25.8) | 0.001 |
Age group | 40.1 ± 13.8 | 39.5 ± 14.3 | 40.2 ± 13.7 | 0.792 |
BMI, kg/m2 | 21.3 ± 3.1 | 21.0 ± 3.2 | 21.4 ± 3.1 | 0.527 |
Smoking history* | 14(11.4) | 7(23.3) | 7(7.5) | 0.027 |
Alcohol abuse | 7(5.7) | 3(10.0) | 4(4.3) | 0.360 |
Comorbidities | | | | |
Previous history of pulmonary tuberculosis | 36(12,120) | 42(9,120) | 36(12,174) | 0.354 |
Other disease# | 22(17.9) | 6(20.0) | 16(17.2) | 0.728 |
CPA | 18(14.6) | 3(10.0) | 15(16.1) | 0.392 |
MDR/XDR | 20(16.3) | 7(23.3) | 13(14.0) | 0.242 |
Chronic pulmonary symptoms | | | | |
mMRC ≥ 1 | 70(56.9) | 14(46.7) | 56(60.2) | 0.193 |
Massive hemoptysis | 20(16.3) | 4(13.3) | 16(17.2) | 0.611 |
Fever | 18(14.6) | 5(16.7) | 13(14.0) | 0.720 |
Sputum | 71(57.7) | 17(56.7) | 54(58.1) | 0.893 |
Pulmonary function test | | | | |
FVC % pred | 59.1 ± 12.8 | 65.1 ± 14.4 | 57.2 ± 11.6 | 0.003 |
DLCO % pred | 57.2 ± 19.2 | 54.3 ± 13.5 | 58.1 ± 20.7 | 0.336 |
Chest CT | | | | |
Cavity | 37(30.1) | 14(46.7) | 23(24.7) | 0.023 |
Contralateral Pulmonary lesions | 82(66.7) | 20(66.7) | 62(66.7) | 1.000 |
Ancillary blood test | | | | |
HB, g/L | 121.6 ± 15.4 | 125.9 ± 15.7 | 120.2 ± 15.2 | 0.079 |
ALB, g/L | 38.7 ± 5.7 | 40.0 ± 7.36 | 38.3 ± 5.1 | 0.161 |
CRP, mg/L | 8.4(2.2,29.0) | 15.5(2.8,39.2) | 7.4(2.0,22.2) | 0.062 |
The operation factors | | | | |
Surgical removal of right | 25(20.3) | 5(16.7) | 20(21.5) | 0.567 |
Time of operation, h | 152(120,180) | 150(120,185) | 155(120,180.0) | 0.739 |
Mean bleeding volum, mL | 700(300,1300) | 800(475,2050) | 600(300,1150) | 0.180 |