Study design and patient characteristics
The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). This study was approved by the Ethics Committee of the First Affiliated Hospital of Soochow University (Approval No. 2022 technology 195) and informed consent was taken from all the patients.
The clinical data of 89 patients undergoing uniportal VATS lung segmentectomy from January 2019 to October 2020 at the First Affiliated Hospital of Soochow University were analyzed. Preoperative examinations were performed to exclude surgical contraindications. There were 55 patients in the stapler group, for whom the staplers of Johnson & Johnson were used to separate the intersegmental plane during the operation. And other 34 patients were in the energy device group, for whom only electrotome and ultrasonic scalpel were used. All operations were performed by the same team of surgeons.
The inclusion criteria
(1) The lesion was < 2 cm in diameter and located in the center of the target lung tissue. Wedge resection was unfeasible. Lung segmentectomy could ensure adequate surgical margin. (2) Lobectomy was contraindicated under the circumstances that the lung function was poor or there were other serious diseases; (3) At least one of the following three characteristics should be met, which were, the postoperative pathology was adenocarcinoma in situ; CT showed that the ground glass composition of nodules was ≥ 50%; Nodules doubling time ≥ 400 d. (4) No obvious surgical contraindications were found in preoperative examination.
Exclusion criteria
(1) Patients in poor physical conditions who were unable to tolerate the operation. (2) Past history of pulmonary surgery. (3) Prolonged operative duration due to intraoperative thoracic dense adhesions.
Interventions
Operations
All patients underwent uniportal VATS lung segmentectomy. 3D reconstruction was performed preoperatively based on the patient’s high-resolution CT. The patient was placed on the unaffected side under general anesthesia. The double-lumen endotracheal tubes were intubated. The unaffected-side lung was ventilated. The utility incision was usually made at the fourth intercostal space, anterior axillary line of the upper lung; as for the lower lung, it was usually made at the fifth intercostal space, anterior axillary line. During the surgery, the pulmonary segmental arteries, veins and segmental bronchus were precisely identified according to the preoperative 3D reconstruction, and were severed respectively. The artery was ligated at the proximal end with a silk thread and then severed by an ultrasonic scalpel or a white stapler, the vein was ligated at the proximal end with a silk thread and then severed by an ultrasonic scalpel or a white stapler, and the segmental bronchus was severed by a blue stapler. The intersegmental plane was identified by the modified inflation-deflation of the lung method, and marked on the lung surface with an electrocoagulation hook.
For patients in the stapler group, the staplers were used to separate the targeted lung segment, which was showed in Figs. 1 and 2, while for patients in the energy device group, the ultrasonic scalpel and the electrocoagulation hook were used, which was showed in Figs. 3 and 4.
The specimen was removed. It was sent for the fast freezing pathological examination after the focus of infection had been marked and the margins had been confirmed to meet the requirements. While waiting for the pathological results, points with obvious air leakage would be sutured. The lymph nodes were sampled in cases of adenocarcinoma in situ carcinoma, microinvasive adenocarcinoma or invasive adenocarcinoma. One chest tube was placed after surgery.
Assessments
The basic information and perioperative data were collected, including age, gender, smoking history, tumor location, tumor size, postoperative pathology, operative duration, operative hemorrhage, number of staplers used, drainage volume on the first postoperative day, total postoperative drainage volume, postoperative chest tube retention duration, postoperative hospital stay, postoperative complications, surgical expenses, postoperative blood routine indexes, and postoperative pulmonary function indexes after 3 months.
The indications for extubation were no pneumothorax or atelectasis, no air leakage, water fluctuating little in the chest tube, pleural effusion is not dark in color, and a daily drainage volume of ≤ 200 ml.
The postoperative complications mainly included atelectasis, pulmonary infection and air leakage. Air leakage levels were applied as follows: Level 0 = never, Level 1 = coughing, Level 2 = deep breath, and Level 3 = always.
Statistical analysis
Statistical analyses were performed with IBM SPSS 19.0 software package (IBM, Armonk, NY, USA). For quantitative data, the distribution morphology and homogeneity of variance were verified. If the data were normally distributed, the Student’s t-test was compared and represented by the mean ± standard deviation (mean ± SD); otherwise, median (interquartile spacing) [M (IQR)], the Mann–Whitney U test was applied. Categorical data was compared using the chi-square (χ2) test or Wilcoxon rank-sum test. Association data were analyzed using odds ratio (OR) and 95% confidence interval (CI) analysis. The logistic regression model of stepwise regression was used for univariate and multivariate analysis, and variables with P < 0.2 in univariate analysis were included in multivariate analysis. P -value < 0.05 was considered statistically significant.