Video-assisted thoracic surgical techniques were introduced in 1991 and were subsequently applied to a wide variety of disorders in the discipline of thoracic surgery. The initial enthusiasm was followed by a wave of skepticism both on the part of general thoracic surgeons and cardiac surgeons alike. It is somewhat ironic that seven years later some of these same cardiothoracic surgeons are touting "minimally invasive" procedures for valve surgery, coronary bypass, and repair of congenital heart defects. Now that the spotlight is off VATS, the pendulum seems to have swung back to the center and is midway between enthusiasm and skepticism. Thoracoscopy has found its place in the management of many different diseases and disorders, however the frequency with which it is used is still highly practitioner dependent. The degree to which it is used at any given institution depends upon the specific thoracic surgeons and how comfortable (and convinced) they are regarding the potential advantages of this approach. A discussion regarding the application of VATS is most easily classified with an anatomic approach.
I. Lung
One of the most controversial applications for VATS continues to be major lung resection for cancer. The larger series have demonstrated safety in the procedure but long-term efficacy (with regard to survival) has not yet been proven.5,13 An interesting analysis of three-year survival recently presented by McKennas group suggests the disease-free three-year survival is in excess of 75 percent for Stage I disease.14
Another area of controversy is the utilization of VATS for resection of pulmonary metastases. It is widely agreed that diagnostic excision is indicated, but some practitioners believe VATS can be used in the therapeutic arena as well.20 This supposition is strongly disputed by McCormack and Ginsberg and others.12
Lung volume reduction surgery is now routinely performed by many institutions utilizing a thoracoscopic approach. Although initially it was suggested that the minimally invasive approach might provide inadequate visualization and, therefore, suboptimal results, reports from several investigators have demonstrated that both unilateral and bilateral thoracoscopic lung volume reduction provides significant clinical improvement.13,16,22 A recent study also suggests that the minimally invasive thoracoscopic approach can be performed with lesser morbidity and mortality than an open sternotomy approach.6
Finally, VATS continues to be routinely utilized for biopsy of diffuse interstitial infiltrates and solitary pulmonary nodules of uncertain etiology. The role in these clinical settings has been very well accepted.
II. Pleura
The thoracoscopic approach is excellent for the visualization and accurate sampling of focal pleural abnormalities. When malignant disease is identified, thoracoscopic pleurodesis with talc insufflation can be quite useful, but recent results suggest that unless thoracoscopy is indicated for diagnostic reasons, a talc slurry introduced by a chest tube is just as effective as thoracoscopic distribution of talc.25
VATS continues to be quite useful for the drainage of hemothoraces and early empyemas and will occasionally prove useful in the diagnosis of recurrent pleural effusions of uncertain etiology.8
Finally, recurrent pneumothorax can be easily treated with a thoracoscopic approach. Controversies still exist regarding the incidence of recurrence when VATS is utilized, but reports have suggested that recurrence rate is less than 5 percent and even lower when specific abnormalities such as blebs are identified and ablated.17,27
III. Esophagus
Several years ago VATS was touted as an ideal approach for myotomy in the treatment of achalasia. Since that time, follow up has suggested significant incidence of occult and clinical reflux in such patients. This has been supplanted entirely by a laparoscopic approach to distal esophageal myotomy with partial fundoplication as the non-invasive option for achalasia therapy.11 In similar fashion, thoracoscopic antireflux procedures have been few and far between as the laparoscopic approach achieves primacy.
A number of incidental benign esophageal diseases including duplication cysts, leiomyomas, and diverticula have been resected utilizing a thoracoscopic approach. Because of the infrequency of these lesions, it is hard to demonstrate quantifiably that the minimally invasive approach is superior to a thoracotomy but this is touted as being an advantage.19,23,27
Finally, there are a few practitioners who are using thoracoscopy in an aggressive fashion to perform minimally invasive esophagectomies.9 While early reports suggest there is little advantage to the thoracoscopic approach, it is only through the ongoing efforts of thoracoscopic practitioners that one will discern for certain whether this is an appropriate utilization of the discipline.
IV. Mediastinum
Thoracoscopy has been used for resection of miscellaneous mediastinal disease including parathyroid adenomas, neurogenic tumors, and bronchogenic cysts.1,3,16 It has been touted as a highly accurate method of minimally invasive staging, specifically for patients with esophageal carcinoma who are placed on investigational protocols.7 A thymectomy can be performed utilizing VATS techniques, as this has been approached with bilateral thoracoscopies as well as left- and right-sided approaches.10 Long-term efficacy for this approach in the myasthenia setting awaits further follow up.
V. Heart
The creation of a pericardial window and/or partial pericardiectomy has long been touted as one of the useful procedures which can be performed thoracoscopically. A subxiphoid window continues to be a preferable approach for many practicing surgeons due to its many advantages including a single incision, absence of intercostal tubes, low cost, and its ability to be performed under local anesthesia. However, for patients with concomitant lung or pleural lesions which require visualization or biopsy, a thoracoscopic approach still is worthwhile.
VATS is now being used on an experimental basis for the performance of transmyocardial revascularization using a laser and clinical efforts are ongoing to perform a completely endoscopically-guided coronary artery bypass.2
VI. Chest Wall
One of the frequently unappreciated diagnoses in the United States is the problem of palmar hyperhidrosis. There is an increasing movement on the part of afflicted patients to achieve lasting relief from this problem even if it requires surgery. A thoracoscopic sympathectomy is a highly effective procedure and truly perhaps one of the best and most appropriate utilizations of thoracoscopy.4
Recently, chest wall and spine procedures are being performed more frequently with a thoracoscopic approach. Resections of the first rib as well as more complex spine surgery are being undertaken at an increasing number of institutions.
VII. Diaphragm
Thoracoscopy has been utilized in patients with diaphragmatic eventrations or paralysis in order to achieve an adequate application and improvement in respiratory function.24 Reports have also appeared which describe VATS techniques for the closure of congenital diaphragmatic defects which present in adolescence or adulthood.21
There is continuing evolution in the application of thoracoscopy to problems within the thoracic cavity. Some applications such as sympathectomy, pleural biopsy, and diagnostic wedge resection of the lung are now widely accepted by the thoracic community and this minimally invasive route appears to be the approach of choice. Other uses for thoracoscopy including thymectomy for myasthenia gravis and lobectomy for lung cancer have been proven to be safe procedures, but results continue to be early or mid-term and long-term follow up must be obtained before thoracoscopy could be called the approach of choice. Other applications such as thoracoscopic esophagectomy and endoscopic CABG remain totally investigational and should only be carried out by those clinicians involved in active and ongoing research within this area.
Bibliogrophy
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