[Three cases of spontaneous mediastinal emphysema].

We report 3 cases of spontaneous mediastinal emphysema. All patients were young males, and had predisposing episodes for development of spontaneous mediastinal emphysema; sports in 2, loud voice in 1. The each chief complaint was dyspnea, throat pain, and epigastric pain. Two patients were admitted, but 1 rejected admission despite sufficient informed consent. All patients became asymptomatic with mediastinal air reabsorption within a week. We should recognize spontaneous mediastinal emphysema as one cause of chest, back, neck and epigastric pain.

[Acute pulmonary embolism performed embolectomy under percutaneous cardiopulmonary support successfully after lung cancer operation].

We have experienced a case of acute pulmonary embolism after lung cancer operation. The case was a 74-year-old male. He underwent left upper lobectomy due to squamous cell carcinoma. He fell into shock state suddenly on the 6th day postoperatively. We diagnosted acute pulmonary embolism, performed urgent embolectomy under percutaneous cardiopulmonary support (PCPS). Postoperative course was smooth, and he has returned to normal daily life. Urgent diagnosis and management are indispensable for acute pulmonary embolism after lung cancer operation from the aspect of residual among of pulmonary vascular bed.

[Surgical management of chest wall tumors].

Twenty-four patients with chest wall tumors underwent resection during the past twenty years. There were 12 female and 12 male patients with ages ranging from 7 months to 78 years (mean 44 years). Five patients had primary malignant neoplasms, 7 had metastases, and 12 had benign tumors. The tumor was located in the soft tissue in 14 patients and in the ribs and the sternum in 10. Ninety-two percent of tumors were diagnosed correctly if they were benign or malignant before resection, however the final diagnosis was made in only 25% of benign tumors and 54% of malignant tumors before surgery. Thirty-one operations were performed in 24 patients and 10 reconstruction with prosthetic materials were done. Concerning malignant neoplasms patients with primary tumors had better prognosis than those with metastases and patients underwent reconstruction had better prognosis than those underwent resection only. We conclude that wide resection with reconstruction is potentially curative treatment.

[Surgery for thymomas and thymic carcinomas; treatment results in terms of WHO histologic typing, Masaoka staging system, and p53 expression].

Forty thymomas and thymic carcinomas were classified in terms of WHO histologic typing, Masaoka staging system, and p53 expression. In WHO histologic typing, type A, AB, B1, B2, B3, and C were 1, 10, 16, 5, 4, and 4 cases, respectively. In Masaoka staging system, I, II, III, and IV were 15, 9, 10, and 6 cases, respectively. Thirteen thymomas exhibited positive p53 expression and 27 did not. Type A and AB thymomas had more favorite prognosis than type B3 and C thymomas, and prognosis of type B1 and B2 was middle. Staging by the Masaoka system also correlated with survival rates. Patients who had p53-negative thymomas survived longer than those who had p53-positive thymomas. A treatment strategy for thymomas and thymic carcinomas should be made on the basis of WHO histologic typing, Masaoka staging system, and p53 expression.

[Intraoperative coronary artery spasm treated by percutaneous cardiopulmonary support in a patient with left lung cancer].

A 53-year-old man with left lung cancer underwent left upper lobectomy and extended mediastinal lymphadenectomy. Shortly before the end of the operation, electrocardiogram showed elevation of ST wave and multiple ventricular premature contractures first, then ventricular fibrillations, and finally cardiac arrest. Coronary artery spasm was strongly suspected. The patient was resuscitated by cardiac massage and countershock immediately, however, such attacks repeated several times. As medication and cardiac pacing were not effective, percutaneous cardiopulmonary support (PCPS) was established. The hemodynamics was stabilized with PCPS. He was weaned off PCPS the next day. He was discharged and has had no attack so far. PCPS is an excellent modality for intraoperative coronary spasm which is uncontrollable by medicines and other methods.

[A study on low grade malignant tumors arisen in the trachea and the bronchus].

Twelve patients who suffered from low grade malignant tumors arisen in the trachea and the bronchus (6 of carcinoid, 4 of mucoepidermoid carcinoma, and 2 of adenoid cystic carcinoma) underwent surgical treatment from 1977 to 1996 in our department. Operations included 1 sleeve resection of the trachea, 1 patch plasty of the trachea, 3 sleeve lobectomies, and 7 lobectomies. Lymph node dissection was performed in 9 of 12 cases. Metastases in lymph nodes were not found in all 12 cases. Five year survival rate of low grade malignant tumors arisen in the trachea and the bronchus was 78.8% and better than that of stage I lung cancers.

[Experimental evaluation of a new gelatin-impregnated woven Dacron vascular prosthesis (CL301)].

We investigated the biological response and biodegradation of CL301, a presealed woven Dacron prosthesis (UBE woven) with glutaraldehyde stabilized gelatin. The sealant does not affect its handling characteristics because of the glycerin treatment. The total content of endotoxin in the CL301 was 5.3 +/- 0.5 pg/mg of sealant material (1.7 +/- 0.2 pg/cm2), which was 1/5 and 1/6 of that found in Hemashield and Gelseal, respectively. The pyrogen test was negative and the content was estimated below the minimum pyrogenic doses for thoracic aortic surgery. Five cm-long grafts with a diameter of 10 mm were implanted into the descending thoracic aorta of dogs weighing 10-16 kg. These grafts were retrieved 2 hours, 7, 10 days, 5, 8 and 10 weeks after implantation. Thrombus-free surfaces were 28%, 77%, at 5 and 10 weeks and there was no excessive inflammatory response to the sealant. The total, and the effective sealant remaining were 80.6%, 56.5% at 5 weeks, 60.8%, 38.3% at 10 weeks, respectively. The sealant was removed more rapidly from the inner surface than from the outer. In half of the graft area, the sealant was removed or detached from the Dacron surface 5 weeks after implantation, indicating that delayed resorption of the sealant substantially did not affect the healing process. We conclude that because of the harmless amount of endotoxin and effective sealing for 5 weeks, followed by an acceptable healing process experimentally, CL301 is the presealed Dacron graft of choice for thoracic aortic surgery.

Myristoyl gelatin as a sealant for Dacron vascular prostheses.

Myristoyl gelatin (MG) retains its gel structure at temperatures above body temperature without any crosslinking. As a coating material, MG adheres well to polyester fibers, and the outermost layers of the sealant that are in contact with blood or surrounding tissue become hydrophilic. We produced MG-impregnated knitted Dacron vascular prostheses (MG graft [MGG]) and investigated the usefulness of MG as a sealant by replacing the thoracic aorta of dogs. MGGs (5 cm long with an inner diameter of 10 mm) were implanted in 5 mongrel dogs (10-20 kg), and the grafts were retrieved at intervals of 4 h and 2, 4, 8, and 15 weeks after grafting. There was no thrombus formation on the flow surface of the MGGs, indicating adequate antithrombogenic properties. No resorption of MG occurred until after 2 weeks, and neither immune reaction nor excessive foreign body reaction was noted. Fragmentation of the sealant induced by cell infiltration began to occur at 4 weeks, yet the sealing effect persisted. The organization of MGG was almost complete at 8 weeks. Because of its pliability and effective adhesion to polyester fibers, its antithrombogenicity, and the persistent sealing effect due to delayed biodegradation and resorption, we conclude that MG is an extremely useful sealant for polyester vascular prostheses.