High frequency jet ventilation at the distal end of tracheostenosis during flexible bronchoscopic resection of large intratracheal tumor: Case series.

INTRODUCTION: Resection of a large intratracheal tumor with severe obstruction via flexible bronchoscope remains a formidable challenge to anesthesiologists. Many artificial airways positioned proximal to tracheal obstruction can not ensure adequate oxygen supply. How to ensure effective gas exchange is crucial to the anesthetic management. PATIENT CONCERNS: Five patients of intratracheal tumor occupying 70% to 85% of the tracheal lumen were scheduled for tumor resection via flexible bronchoscope. DIAGNOSIS: The patients were diagnosed with intratracheal tumor based on their symptoms, radiographic findings and tracheoscopy. INTERVENTIONS: We describe a technique of high frequency jet ventilation (HFJV) using an endobronchial suction catheter distal to tracheostenosis during the surgery, which ensured the good supply of oxygen. We applied general anesthesia with preserved spontaneous breathing. A comprehensive anesthesia protocol that emphasizes bilateral superior laryngeal nerve (SLN) block and sufficient topical anesthesia. An endobronchial suction catheter was introduced transnasally into the trachea and then advanced through the tracheostenosis with the tip proximal to the carina under direct vision with the aid of fiber bronchoscope. HFJV was then performed through the suction catheter. OUTCOMES: The SPO2 maintained above 97% during the surgery. Carbon dioxide retention was alleviated obviously when adequate patency of the trachea lumen achieved about 30 min after the beginning of surgery. HFJV was ceased and all patients had satisfactory spontaneous breathing at the end of the procedure. CONCLUSION: HFJV at the distal end of tracheostenosis is a suitable ventilation strategy during flexible bronchoscopic resection of a large intratracheal tumor.

[Angiogenesis in chronic ischemic porcine myocardium after transfer of VEGF165 and angiopoietin-1 mediated by recombinant adeno-associated viral vector].

OBJECTIVE: To study the effects of combination of angiopoietin-1 (ANG-1) and vascular endothelial growth factor165 (VEGF165) gene transfer mediated by recombinant adeno-associated viral vector on the neovascularization in chronic ischemic porcine myocardium. METHODS: An ameroid constrictor was implanted around the left circumflex coronary artery (LCX) via endoscopy. Six weeks later, coronary angiography revealed that the myocardial ischemia was established by gradual occlusion of the left circumflex coronary artery (LCX). Sixteen swine with the total occlusion or partial stenosis (> 85 %) of the LCX were divided into 4 groups (4 in each group): group I, group II and group IV (control) received direct myocardium injection of rAAV2 VEGF165, rAAV2 ANG-1 or PBS alone, respectively; group III received rAAV2 VEGF165 and rAAV2 ANG-1. Selective coronary angiography and ultrasonography were performed perioperatively to evaluate the cardiac function and the formation of collateral circulation. The expression of VEGF165 and ANG-1 proteins were assessed using ELISA or Western blot. The degree of angiogenesis was assessed by use of immunohistochemical analysis. RESULT: Angiography showed that the occlusion of all LCX was completed or exceeded 95% 6 weeks after ameroid constrictor implantation, indicating the successful establishment of animal model. The expression levels of VEGF165 in group I and III and ANG-1 in groups II and III began to increase at d7 after transfection and reached the peak at d14; then decreased gradually to the normal level after 3 months. The expression levels of VEGF165 in group II and group IV or that of ANG-1 protein in group I and group IV had no markedly changes at different time after transfection. There were significant increase in capillary density and arteriole density and more side branch vessels formed in group III compared with other groups. Echocardiographic measurements showed that the left ventricular systolic function of animals in groups I, II and III increased significantly after gene transfection, especially in group III; but there was no changes in group IV. CONCLUSION: Myocardial perfusion and the left ventricular systolic function are improved after rAAV2 VEGF165 or rAAV2 ANG-1 transfection, which is associated with the angiogenesis in porcine model of chronic myocardial ischemia.

[Create a standard mini-swine model of chronic ischemic myocardium by thoracoscopy].

OBJECTIVE: To create a standard mini-swine model of chronic ischemic myocardium by endoscopy for the research of gene transfer and stem cell. METHODS: Twenty-three male China experimental minipigs were used, aged from 8 to 11 months with a mean of (9.3 +/- 1.8) months and weighed from 20 to 30 kg with a mean of (29.3 +/- 4.3) kg. The myocardial ischemia was established by gradual occlusion of the left circumflex coronary artery (LCX) with an Ameroid constrictor. The Ameroid constrictor was implanted around LCX by endoscopy. Selective coronary angiography, electrocardiogram and Echo-Doppler study were performed perioperatively to evaluate the degree of stenosis. RESULTS: Chronic ischemic myocardial models were successfully generated in 20 of 23 swine by full-endoscopy. Ameroid constrictors were placed at the LCX accurately. Three swine died of anesthetic accident, cardiac arrhythmia at secondary coronary angiography, and pulmonary infection within 6 weeks after operation respectively. Operation time was 25 to 65 min with a mean of (46 +/- 9) min. The blood loss was 30 to 60 ml with a mean of (55 +/- 12) ml. Six weeks later, coronary angiography revealed the total occlusion and partial stenosis (> 85%) of the LCX occurred in 7 and 13 swine respectively. Cardiac systolic and diastolic dysfunction were found in all swine. The ejection fraction value was (65.0 +/- 6.3)% before operation and (41.0 +/- 9.3)% after operation (P = 0.008). The fractional shortening value was (36.2 +/- 4.3)% before operation and (34.2 +/- 2.3)% after operation (P = 0.027). CONCLUSION: The endoscopic surgery is a less invasive way to create a standard mini-swine model of chronic ischemic myocardium with effective results.