Objective    To evaluate the prognosis of benign esophageal perforation by Pittsburgh scoring system (perforation severity scores, PSS) combined with co-disease index (Charlson comorbidity index, CCI). Methods    Thirty patients with benign esophageal perforation from August 2016 to August 2018 in our hospital diagnosed by imaging or endoscopy were selected, including 14 males and 16 females, aged 68.660±10.072 years. After treatment, we retrospectively analyzed whether there was any complication in the course of treatment, the healing of esophageal perforation at discharge and the follow-up after discharge. And the patients were divided into a stable group (20 patients with no complication, clear healing of esophageal perforation at discharge or death during follow-up) and an unstable condition group (10 patients with complications, esophageal perforation at discharge or death during follow-up). Complete clinical data of all the patients were obtained and were able to be calculated by the scores of PSS and CCI scoring system. The difference of PSS and CCI scores between the two groups was compared, and the clinical value of PSS combined with CCI score in the prognosis of benign esophageal perforation was analyzed. Results    In the stable group, the PSS was 2.750±1.372 (95%CI 2.110 to 3.390), CCI score was 2.080±1.055 (95%CI 1.650 to 2.500) with a statistical difference between the two systems (P=0.000). In the unstable group, PSS was 7.300 ±1.829 (95%CI 7.300 to 8.120), CCI was 4.640±1.287 (95%CI 4.220 to 5.060) with a statistical difference between the two systems (P<0.05). The area under the receiver operating characteristic  curve of PSS and CCI scores in the prognostic evaluation of benign esophageal perforation was 0.982 and 0.870 respectively, which was statistically significant (P<0.05). Conclusion    Esophageal perforation is a dangerous condition. It is of great practical value to evaluate the condition of esophageal perforation by PSS and CCI scores.

Objective    To explore the feasibility of establishing a rabbit model of flail chest. Methods    Flail chest model was eatablished in 12 New Zealand white rabbits after anesthesia and sterile surgery. The paradoxical movement of chest wall was recorded by the biological signal acquisition system, arterial blood was collected for blood gas analysis, the vital signs were recorded by electrocardiogram (ECG) and the lung tissue was taken for the pathological analysis at the end of the experiment. The effect of flail chest on the respiratory function of experimental animals was analyzed to evaluate the feasibility of establishing flail chest model. Results    All surgeries were successful without mortality. The operation time was 41.42±7.08 min. Duration of endotracheal intubation was 79.33±12.21 min. Statistical results showed that the pH, partial pressure of arterial carbon dioxide (PaCO2) and base excess (BE) increased; while partial pressure of oxygen (PaO2) and oxygen saturation (SaO2) reduced. Pathological results showed that flail chest not intervented for a long period would lead to organic lesions. Conclusion    The rabbit model of flail chest is feasible, safe, repeatable, easy and simple to handle. The animal is easy to access which is the foundation to study the disease process, recovery procedure and the efficacy after intervention.