Objective Direct impact is a common mechanism of injury for blunt thoracic injury, and if resulting thoracic injury is severe the mortality may be as high as 10% ～ 25% . We aim to develop a mechanical device for animal impact injury experiment, so as to establish a rodent model of severe thoracic injury. Method A spring operated mechanical device for animal impact injury experiment was developed. The device allowed for accurate controlled delivery of impact force to specific areas of the chest well, at specific velocities and degrees of chest compression. Eghty-four male Sprague-Dawley rats were anaesthetized and underwent left carotid artery cannulation. They were randomly divided into seven groups and given the following treatment: group A (Control group) were subjected to sham impact; group B to G animals were subjected to impacts on the right lateral superior chest at different velocities and degrees of chest wall compression. ( B 3 m/s, 20%; C 3 m/s 40%; D 6 m/s 20%; E 6 m/s 40%; F 9 m/s 20%; G 9 m/s 40%). Arterial blood gas samples were taken just before injury, and at 2 and 12 post injury. All rats were sacrificed at 12 hours and their degree of thoracic injury rated. Pathological examination of injured lung tissue was also performed. Results The device was able to deliver impact forces accurately, with ＜ 4% deviation from desired velocity and ＜ 3 mm deviation from target area of impact. Other than the control group, all animals experienced significant hemodynamic changes immediately post impact. Arterial blood gas analysis detected significant hypocapnia in groups B and C. Significant hypoxemia and hypocapnia was detected in groups D, E and F. In groups B,C,D and F, die impact produced a mild thoracic injury with low mortality rate at 12 hours. In group E, the impact produced severe thoracic injury with mortality rate of 33.33% at 12 hours. Group C animals sustained the most serious thoracic injury with mortality rate of 83.33% at 12 hours. Pathological examination revealed injuries from direct trauma as well as secondary lung injuries. Conclusions Our device was able to repetitively deliver accurate and precise impact forces to rats and allows us to establish a rodent model of severe thoracic injury firm blunt trauma. We found that with our device, impact force at velocity of 6 m/s and 40% chest compression produced the most severe lung injury in rats.This helps us establish a rodent model of severe thoracic injury which can be use for future research in severe blunt thoracic trauma and the secondary lung injuries.

Objective This study assesses a feasible and safe volume threshold for chest tube removal following a VATS lobectomy.Methods The study included 168 consecutive patients who underwent VATS lobectomy or bilobectomy with two insicion between August 2012 and February 2014.Eligible patients were randomized into 3 groups:Group A (chest tube removal at the drainage volume of 150 ml/d or less.n =49) ; Group B (chest tube was removed when the drainage volume was less than 300 ml/d.n =50) ; Group C(chest tube removal when the drainage was less than 450 ml/d.n =51).And there were 18 patients who were excluded.All patients got the same postoperative care with a clinical pathway,and all patients were followedup 7 days after discharge from hospital.The time of extracting drainage tube,postoperative hospital stay,postoperative VAS values,dosage of analgesic,incidence of complications and thoracocentesis were measured.Results There were no statistically significant differences among 3 groups with general information and incidence of complication (P ＞ 0.05).And there were statistically significant differences between Group A and Group B with the time of extracting drainage tube,postoperative hospital stay,postoperative VAS values,dosage of analgesic(P ＜ 0.05).But there were no statistically significant differences between Group A and Group B with incidence of thoracocentesis(P ＞0.05).Analysis of data showed no statistically significant differences between Group B and Group C with postoperative hospital stay,postoperative VAS values and dosage of analgesic (P ＞ 0.05),but there were statistically significant differences for incidence of thoracocentesis (P ＜ 0.05).Conclusion A 300 ml/d volume threshold for chest tube removoal after VATS lobectomy is feasible and safe,and it can bring more advantages than the 150 ml/d volume threshold.On the other hand,a 450 ml/d volume threshold for chest tube removoal after VATS lobectomy may increase the risk of thoracocentesis.

Objective:To explore the chest drainage effect of use different diameter thoracic drainage tube after biportal thoracoscopic radical resection for lung cancer.Methods:300 patients with lung cancer who received biportal thoracoscopic radical resection were divided into group A and group B from January 2018 to September 2020. Group A: 150 patients with single 28# thoracic drainage tube after surgery. Group B: 150 patients with single 20# thoracic drainage tube and a negative pressure drainage ball after surgery. The postoperative drainage volume, drainage time, postoperative pain, postoperative thoracic puncture, hospital stay and total hospital expenses were compared.Results:No significant difference between the two groups in terms of sex, age, postoperative pathological type and resection range. There no significant difference between the two groups in total drainage volume [(1 010.31±525.29)ml vs.(985.35±403.93)ml] and total drainage time [(5.69±2.55)days vs.(5.42±1.94)days]. The difference of different diameter thoracic drainage tube used [(5.69±2.55)days vs.(2.88±0.64)days] was statistically significant. There were significant differences between two groups in terms of hospital stay[(12.64±2.89)days vs.(11.25±1.62)days] and total hospital expenses[(62 899.00±1 588.82) yuan vs.(64 327.00±3 587.04)yuan]. No significant differences on the postoperative first day, second day and third day in VAS pain scores. However, on the postoperative fifth day, the difference was statistically significant. In addition, the rate of group A postoperative thoracic puncture was 10%, group B was 0, the comparison was statistically significant.Conclusion:Using a single thin thoracic drainage tube and plus a negative pressure drainage ball after biportal thoracoscopic radical resection for lung cancer will not cause pain increase, shorten hospital stay days, control the rate of postoperative thoracic puncture and then reduce patients total hospital expenses.

Objective     To explore the correlation between the imaging features of peripheral ground-glass pulmonary nodules and the invasion degree of lung adenocarcinoma, and the high risk factors for infiltrating lung adenocarcinoma under thin-slice CT, which provides some reference for clinicians to plan the surgical methods of pulmonary nodules before operation and to better communicate with patients, and assists in building a clinical predictive model for invasive adenocarcinoma. Methods    Clinical data of the patients with peripheral ground-glass pulmonary nodules (diameter≤3 cm) in thin-slice chest CT in the First Affiliated Hospital of Soochow University from January 2019 to January 2020 were continuously collected. All patients underwent thin-slice CT scan and thoracoscopic surgery in our center. According to the pathological examination results, they were divided into two groups: an adenocarcinoma lesions before infiltration group, and an invasive lung adenocarcinoma group. The thin-slice CT imaging parameters of pulmonary nodules were collected. The nodular diameter, mean CT value, consolidation tumor ratio (CTR), nodular shape, vacuolar sign, bronchial air sign, lobulation sign, burr sign, lesion boundary, pleural depression sign, vascular cluster sign and other clinical data were collected. Univariate and multivariate analyses were conducted to analyze the independent risk factors for the infiltrating lung adenocarcinoma, and to analyze the threshold value and efficacy of each factor for the identification of infiltrating lung adenocarcinoma. Results     Finally 190 patients were enrolled. There were 110 patients in the adenocarcinoma lesions before infiltration group, including 21 males and 89 females with a mean age of 53.57±10.90 years, and 80 patients in the invasive lung adenocarcinoma group, including 31 males and 49 females with a mean age of 56.45±11.30 years. There was a statistical difference in the mean CT value, nodular diameter, CTR, gender, smoking, nodular type, nodular shape, vacuolar sign, lobulation sign, burr sign, lesion boundary, pleural depression sign, vascular cluster sign between the two groups (P<0.05). However, there was no statistical difference between the two groups in age (P=0.081), lesion site (P=0.675), and bronchial air sign (P=0.051). Multiple logistic regression analysis showed that nodular diameter, mean CT value, CTR and lobulation sign were independent risk factors for differentiating preinvasive adenocarcinoma from invasive adenocarcinoma. At the same time, the threshold value was calculated by Youden index, indicating that the CTR was 0.45, the nodal diameter was 10.5 mm and the mean CT value was –452 Hu. Conclusion     In the peripheral ground-glass pulmonary nodules, according to the patient's CT imaging features, such as mixed ground-glass nodules, irregular shapes, vacuoles, short burrs, clear boundaries, pleural indentations, and vascular clusters, have a certain reference value in the discrimination of the invasion degree of ground-glass pulmonary nodules. At the same time, it is found in this research that peripheral ground-glass pulmonary nodules with diameter greater than 10.5 mm, CT value greater than –452 Hu, CTR greater than 0.45 and lobulation sign are more likely to be infiltrating lung adenocarcinoma.