Ming-Jang Hsieh

Video-assisted thoracic surgery. The Chang Gung experience.

Thoracoscopy has assumed a major role in the management of a variety of surgical diseases of the chest. This technique, which was primarily devised for diagnostic purposes, has subsequently come to be used for therapeutic applications in most centers today. In this report we review 300 cases of therapeutic thoracic procedures in which a video-assisted technique was used. We describe mainly our own experience and the basic approach strategies we found helpful in the video-assisted procedures. No complications or deaths were attributable to these procedures. Our conclusions were as follows: (1) Video-assisted thoracic surgery can be as effective therapeutically as many formal thoracotomy. (2) Excellent exposure can be obtained by the use of double-lumen endotracheal tubes. (3) Video-assisted thoracic surgery is an excellent alternative treatment for pneumothorax, blebs, and bullous disease. (4) Video-assisted thoracic surgery allows safe, complete, visually guided wedge resection of lung lesions, lobectomy, pericardiectomy, removal of mediastinal tumor, esophagectomy, and reconstruction of the thoracic esophagus. (5) Video-assisted thoracic surgery also allows management of a broad scope of other general thoracic diseases such as empyema, pleural effusion, and chest trauma (hemothorax), as well as cancer staging. (6) Video-assisted thoracic surgery will not compromise the primary diagnostic and therapeutic goals set forth for the patient. (7) Because conventional instruments and extended manipulation incisions can be used, video-assisted thoracic surgery offers the promise of expediency, safety, minimal discomfort, less postoperative pain, quick functional recuperation, excellent cosmetic healing, shortened stays in the hospital, and therefore savings in cost. Accordingly, we are now using video-assisted thoracic surgery to treat the majority of patients with surgical diseases of the chest.

Thoracoscopic management of effusive pericardial disease: Indications and technique

Video-assisted thoracoscopic technique was evaluated in 28 patients who underwent operation for massive pericardial effusion. Excellent results were obtained using this newly developed approach for inspection of all pericardial surfaces as well as pleural and pulmonary disorders. No perioperative or postoperative complications ensued. Videothoracoscopy revealed positive lung malignancies in 11 patients, and these would not have been promptly diagnosed without thoracoscopy. Thoracoscopy also confirmed metastatic deposits on the pleura and diaphragm in 4 other patients. The visible nodules were proved to be metastatic adenocarcinoma. In 13 patients, thoracoscopy did not reveal malignancy, although 2 of these patients had a clinically suspected malignant lung tumor. Other indications for thoracoscopic drainage included 2 patients with impending pericardial tamponade after heart procedures and 6 patients with recurrent/loculated pericardial effusion. All of the patients showed promising and favorable postoperative courses after thoracoscopy. From our experience, video-assisted thoracoscopy was a safe and effective procedure, especially for those patients with combined pericardial effusion and abnormal pulmonary or pleural pathology in whom subxiphoid pericardial window was not clearly diagnostic at the time of operation. It was effective also in the situation with recurrent or loculated pericardial effusion which allowed localization and drainage of it. We believe that the use of videothoracoscopy to visualize the whole pericardial and pleural cavity will continue to be of great benefit to patients with combined pericardial and pleural/lung diseases.

Protection of the brain by retrograde cerebral perfusion during circulatory arrest

Hypothermic circulatory arrest is commonly used to facilitate repair of complex congenital heart defects and aortic lesions and for complex neurosurgical procedures. However, extended periods of circulatory arrest may impair cerebral metabolism and cause ischemic injury. Retrograde cerebral perfusion has been applied recently in aortic surgery to protect the brain. From January 1991 to December 1993, 29 patients underwent emergency operations to repair acute type A aortic dissection with the aid of hypothermic circulatory arrest. Six patients received hypothermic circulatory arrest without retrograde cerebral perfusion with a rectal temperature of 16.4 degrees +/- 0.9 degrees C (mean +/- standard error of the mean, group 1). Retrograde cerebral perfusion during hypothermic circulatory arrest was performed in 15 patients with a rectal temperature of 15.9 degrees +/- 0.5 degrees C (group 2) and in eight patients with a rectal temperature of 21.7 degrees +/- 0.8 degrees C (group 3). The hypothermic circulatory arrest times were 25 +/- 4, 42 +/- 4, and 63 +/- 6 minutes, respectively (p < 0.05). The cardiopulmonary bypass times were 173 +/- 5, 184 +/- 7, and 143 +/- 6 minutes, respectively (p < 0.05). All patients survived the operation and regained consciousness with no neurologic defects. Follow-up (mean 23.2, 14.5, and 5.1 months, respectively) was complete in all patients except one. This patient, from group 2, was killed in a road traffic accident 12 months after the operation. Our experience suggests that retrograde cerebral perfusion can effectively protect the brain from ischemic injury and extend the safe period of hypothermic circulatory arrest. With the aid of retrograde cerebral perfusion, prolonged circulatory arrest can probably be performed safely with moderate hypothermia.

Thromboxane A2: An endothelium-derived vasoconstrictor in human internal mammary arteries

The internal mammary artery (IMA) has become the conduct of choice for coronary artery bypass grafting. However, the IMA graft can exhibit vasoconstriction during the perioperative period. Experiments were designed to determine the role of cyclooxygenase products in human IMA during hypoxia. Rings of IMA, with and without endothelium, were suspended in organ baths containing physiologic salt solution. Rings were contracted with norepinephrine and then exposed to hypoxia for 15 minutes. In segments with endothelium, hypoxia induced a transient relaxation followed by contraction. This contraction was associated with a significantly increased production of thromboxane B2, the stable metabolite of thromboxane A2 (n = 10; from 120.7 +/- 3.5 pg/mg wet tissue before hypoxia to 175.8 +/- 5.2 pg/mg during hypoxia; p < 0.05). This hypoxic contraction could be attenuated by indomethacin. However, thromboxane B2 could not be detected in samples from organ baths containing IMA segments without endothelium before or during hypoxia. This study demonstrated that endothelium of human IMA grafts releases thromboxane A2 basally and that production is augmented by hypoxia, which acts to constrict the underlying vascular smooth muscle, increase vascular tone, and promote ischemic events such as vasospasm and thrombosis, particularly in hypoxemic patients.

Acute endothelial reperfusion injury after coronary artery bypass grafting

Coronary artery endothelium exhibits functional impairment after ischemia and reperfusion. Canine left anterior descending coronary arteries were exposed to ischemia (60 minutes) followed by reperfusion (60 minutes) through a left internal mammary artery graft. In organ chamber experiments, control (left circumflex coronary artery) and reperfused (left anterior descending coronary artery) arterial segments were contracted with prostaglandin F2 alpha and exposed to hypoxia (oxygen tension = 35 +/- 5 mm Hg). Reperfused coronary rings with endothelium exhibited contractions to hypoxia that were significantly greater than contractions in control rings with endothelium (+78% +/- 8% and +14% +/- 5%, respectively; p < 0.05). This phenomenon could be blocked by NG-monomethyl-L-arginine. Electron microscopic studies showed platelet adhesion and aggregation, denudation of the endothelium and disruption of the intercellular junctions, edematous subendothelial matrix, and vesiculation of the smooth muscle cells in reperfused LAD. Swelling, vacuole formation, and loss of neurofilament occurred in the nerve fibers accompanying the vessels. These phenomena were not observed in control vessels. This study demonstrates that early after coronary artery bypass grafting, hypoxia can induce coronary vasospasm mediated by an L-arginine-dependent metabolic pathway in the endothelium. The ultrastructural changes in the coronary endothelium include platelet adhesion, aggregation, and platelet-induced contraction of coronary smooth muscle. The endothelium-dependent hypoxic coronary vasospasm and ultrastructural changes in the coronary endothelium may play an important role in the pathogenesis of myocardial ischemia and infarction after coronary artery bypass grafting.

Surgical management of thrombotic disc valve

Thrombotic obstruction, a rare but often fatal complication of cardiac valve prostheses, appears to occur more frequently in tilting-disc valves than in other valve designs. Its diagnosis and surgical treatment remain a challenge. Ten consecutive patients who had thrombosis of a tilting-disc valve prosthesis were treated in Chang Gung Memorial Hospital from November 1982 to August 1990. Preoperative clinical features, including exertional dyspnea, new murmur, and absence of a metallic click from the prosthetic valve, occurred in all of the patients. Symptoms were present for 1 week or more before reoperation in 70% of the patients; nevertheless, many patients were referred only after acute exacerbation of heart failure and development of pulmonary edema. Echocardiography confirmed prosthetic valve malfunction in 90% of the patients. One unconfirmed case was later documented by cardiac catheterization. Anticoagulant therapy was in the therapeutic range for only half of the patients at the time of admission. Prompt reoperation was performed for thrombectomy (8 patients, all survived) or valve replacement (2 patients, one death). Long-term outcome was satisfactory in all survivors with a mean follow-up of 31.6 months. These findings emphasize the importance of considering the diagnosis of thrombosis in patients with mechanical heart valve prostheses who are first seen with nonspecific symptoms and minor changes of their physical findings. The diagnosis could be easily made by echocardiography. Thrombectomy is an easy, fast, and safe procedure, especially for these critically ill patients.

ONE-STAGE OPERATION FOR TREATMENT AFTER DELAYED DIAGNOSIS OF THORACIC ESOPHAGEAL PERFORATION

Perforation of the thoracic esophagus can be fatal unless diagnosed promptly and treated effectively. The high mortality with delayed treatment is due principally to an inability to effectively close the perforation and prevent leakage. From 1982 to 1988, 7 consecutive patients (aged 16 to 73 years) were treated after a delayed diagnosis (26 hours to 25 days) of thoracic esophageal perforation. In all patients, the perforation was closed after debridement with total exclusion of the esophagus (T-tube cervical esophagostomy plus absorbable ligatures applied to the esophagogastric junction and the cervical esophagus distal to the esophagostomy). Radical decortication and wide mediastinal and pleural drainage were also done. Nutritional supply was given through a feeding gastrostomy. Antibiotics were administered according to the results of cultures. All patients survived. Continuity of the esophagus was established by removal of the T tube and spontaneous absorption of the ligatures. Endoscopy and esophagography performed 4 weeks after the initial operation showed a well-healed esophagus without stenosis or leakage in all patients. No secondary thoracotomy or esophageal reconstruction was necessary. No dysphagia was noted during follow-up (range, 12 to 50 months; mean follow-up, 23 months). We conclude that primary closure of the perforation and total esophageal exclusion with the use of absorbable ligatures and T-tube esophagostomy can provide a one-stage operation with good results for repair of thoracic esophageal perforation diagnosed late.

Thoracoscopic loop ligation of parenchymal blebs and bullae: Is it effective and safe?☆☆☆

Surgeons who have gained experience and confidence with video-assisted thoracic surgery are now routinely applying the minimally invasive approach to treat patients with spontaneous pneumothorax. Although the endoscopic stapling device may be a preferred method for resection of parenchymal blebs or bullae, the stapling device is not inexpensive. In an effort to contain costs since we started performing the video-assisted thoracoscopic procedure in chest surgical diseases, we have used a self-made endoscopic loop as an alternative method. It has assisted us in performing bulla ablation in a cost-effective manner. Over a 4-year period (1992 to 1996), we assessed the efficacy of ligating parenchymal blebs and bullae with a self-made endoscopic loop by video-assisted techniques. A total of 263 ligations were performed in 250 patients. Surgical indications included recurrence (n = 146), bilaterality of the disease (n = 13), hemopneumothorax (n = 7), radiologically demonstrated large bulla (n = 9), persistent air leak (n = 52), and nonexpansion of the lung (n = 23). There were no operative deaths. Early postoperative complications included a dislodged endoscopic loop necessitating reexploration in one patient and postoperative minor wound infections in 13. The average postoperative hospitalization was 4.5 days. Two hundred seventeen patients (86.8% of all patients) were followed up for a median of 28 months (1 to 46 months) after the operation. There have been no recurrences to date. Our results showed that thoracoscopic loop ligation is safe and effective in managing blebs and parenchymal bullae, with a lower cost, fewer complications, and a lower recurrence rate than provided by standard surgical techniques. On the basis of our results, we advocate the use of the self-made endoscopic loop for ligation of parenchymal blebs and bulla in patients with spontaneous pneumothorax to achieve a truly cost-effective and minimally invasive thoracoscopic procedure.

Long-term results of polytetrafluoroethylene mitral annuloplasty

Prosthetic rings are customarily used for mitral annuloplasty to plicate and reinforce the annulus and keep the annulus from further dilating. From July 1984 to March 1992, mitral annular plication using polytetrafluoroethylene (PTFE) graft material was performed on 73 patients (age range, 15 to 69 years; mean, 35.7 years) with mitral regurgitation. The cause of the mitral regurgitation was rheumatic in 50.7% and degenerative in 36.9% of the patients. After other repair procedures on the mitral valve apparatus had been performed, a PTFE graft (3 mm) was tailored to the length of the free edge of the anterior leaflet and then inserted at the posterior part of the mitral annulus between the commissures. The operative mortality was 2.7%. Follow-up ranged from 0.7 to 8.5 years (mean, 5.6 years). Postoperative echocardiography confirmed that 94.2% of the survivors had either no or only mild mitral regurgitation with a large mitral valve area (2.7 +/- 0.3 cm2) and almost no pressure gradient across the mitral valve or left ventricular outflow tract. Two patients successfully underwent redo PTFE mitral annuloplasty. Two patients died, one 15 and the other 20 months later, due to myocardial failure, with no mitral regurgitation. The event-free survival rate was 90% +/- 4% at 8 years. We conclude that PTFE mitral annuloplasty is an effective procedure that yields good long-term results.

Continuous antegrade warm blood cardioplegia attenuates augmented coronary endothelium–dependent contraction after cardiac global ischemia and reperfusion

BACKGROUNDnExperiments were designed to evaluate the effect of warm blood cardioplegia on endothelium-dependent contraction of the coronary endothelium after cardiac global ischemia and reperfusion.nnnMETHODnDogs (n = 12 in each group) were exposed to extracorporeal circulation with the body temperature at 37 degrees C (group 1) or 28 degrees C (groups 2 and 3). The ascending aorta was crossclamped for 120 minutes while continuous infusion of warm blood cardioplegec solution (group 1) or intermittent infusion of cold (4 degrees C) crystalloid cardioplegic solution (group 2) was performed via the coronary arteries through the aortic root. Cardioplegic solution was not used in group 3 animals. The heart was then allowed to function for 60 minutes of reperfusion. Reperfused (groups 1, 2, and 3) and control (group 4) coronary arteries were then harvested for study.nnnRESULTSnPerfusate hypoxia caused endothelium-dependent contraction in the arteries of all four groups that could be attenuated by NG-monomethyl-L-arginine (L-NMMA) or L-NMMA plus D-arginine, but not by L-NMMA plus L-arginine or endothelin receptor A and B antagonist PD 145065. The endothelium-dependent contraction results in groups 2 and 3 (75% +/- 4% and 80% +/- 5%, respectively) were significantly greater than those in groups 1 and 4 (15% +/- 3% and 18% +/- 5%, respectively). Scanning electron microscope studies showed that platelet adhesion and aggregation, areas of microthrombi, disruption of endothelial cells, and separation of the intercellular junction could be found in coronary segments from groups 2 and 3, but not in vessels from groups 1 and 4.nnnCONCLUSIONnThese experiments suggest that global ischemia and reperfusion enhances hypoxia-mediated endothelium-dependent contraction of the coronary endothelium and damages the ultrastructure. These kinds of changes can be prevented by continuous antegrade infusion of warm blood cardioplegic solution during global ischemia.