| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Ann Thorac Surg 1995;60:873-874
© 1995 The Society of Thoracic Surgeons
Centre de Pneumologie de Laval, Sainte-Foy, Québec, Canada
Emphysema is an anatomic alteration of the lung characterized by abnormal and permanent enlargement of air spaces distal to the terminal bronchiole. It is accompanied by destructive changes of their walls. It is a diffuse process and because of the permanence of enlargement and destruction, it is nonreversible, and operation should at best be considered palliative. Five-year survival figures are on the order of 25% for patients whose forced expiratory volume in 1 second is less than 0.75 mL [1].
In this issue of The Annals of Thoracic Surgery, Wakabayashi [2] presents a large experience with thoracoscopic laser pneumoplasty for patients with severe chronic obstructive lung disease. By this procedure, he hoped to restore the anatomic fine structure of the lung so that function would improve secondarily. In physiologic terms, one has to theorize that less hyperinflation will increase the respiratory capacity, decrease the work of breathing, decrease airflow obstruction, and improve on gas exchange. Although Wakabayashi points out that reduction in lung volume is not the objective of his operation, it seems obvious that this is what is being accomplished. These concepts are important because a clear understanding of the pathophysiology involved is the only way to find parameters consistently predictive of good surgical results.
Terminology is also important to standardize therapy and compare results. Doctor Wakabayashi is operating on patients with type III and IV bullae. From his previous work, a type III bulla represents diffuse emphysema without actual true bullae [3], whereas a type IV bulla represents a trabeculated bulla that is part of a generalized process. In both, laser pneumonoplasty may be beneficial in improving the elasticity of the lung as well as the function of the diaphragm and intercostal muscles.
The results of operation for chronic obstructive lung disease should be judged by the benefits-how much better the patients are and for how long-versus the operative mortality and morbidity. In addition, follow-up should include objective data concerning indices of airflow obstruction and gas exchange. Because of their subjectivity, clinical parameters may be less reliable than pulmonary function studies, and almost every operation described for the treatment of emphysema since the beginning of the 20th century has shown that patients were less dyspneic about 80% of the time. Costochondrectomy, for instance, was reported to be followed by great relief of dyspnea for many years, and it also increased the vital capacity by about 500 to 700 mL on the average [4]. Similarly, Nakayama [5] presented in 1961 a series of 3,914 glomectomies with 81.3% of patients showing cure or improvement at 6 months.
In Dr Wakabayashi's series, 500 patients underwent thoracoscopic laser pneumoplasty for emphysema. The operation was done unilaterally in 443 patients and bilaterally in 57 (11%). The technique has major differences with the procedure recently popularized by Cooper and associates [6], in which 20% to 30% of each lung is resected through open sternotomy. Although there are no data to show that operation on one side is better than on both, it is logical to postulate that operating on both sides will prevent overexpansion of the remaining lung with possible loss of function. The reported operative mortality of 4.8%, with a higher incidence in patients with oxygen dependency and a forced expiratory volume in 1 second less than 14%, compares well with what is reported after bullectomy for patients with generalized emphysema. Doctor Wakabayashi's follow-up data are, however, fragmented and difficult to interpret. Clinical and subjective improvement was reported by 87% of the patients, but only 222 responded to the questionnaire. It is possible that patients with the worst result did not return the questionnaire, so that the data do not truly reflect the results achieved over the entire population. In addition, clinical improvement is not documented by the use of accepted dyspnea indexes or quality of life scales. Similarly, the results of pulmonary function studies done preoperatively and postoperatively are difficult to assess because they were done in only half the population, which may be naturally selected by the excellence of their clinical result. It is worth noting, however, that preoperative total lung capacity was only 112.2% of predicted, a finding seldom seen in patients with diffuse emphysema.
Much has been done throughout the 20th century to try to improve the quality of life of emphysema patients. Operations have been done to permit enlargement of the lungs, to reduce volume, to restore the normal function of the diaphragm, or to increase the blood supply from the chest wall to the lung. At the time of their description, all procedures were based on what appeared to be clear understanding of the pathogenesis of the disease, and all were championed by leading surgeons across Europe and the United States. Early results were always encouraging, but the severity of emphysema and the wrong understanding of the problem were the limiting factors for sustained good results [7]. Failures were also due to the nonavailability of an experimental model in which physiologic concepts could be evaluated.
In this age of modern medicine and high-technology statistical analyses, the next step in surgery for emphysema should involve phase III clinical trials comparing standard medical treatment with the proposed operation.
Footnotes
Address reprint requests to Dr Deslauriers, Centre de Pneumologie de Laval, 2725 chemin Sainte-Foy, Sainte-Foy, Que, Canada G1V 4G5.
References
This article has been cited by other articles:
|
|
 |
|
  M. F. Shamji, D. E. Maziak, F. M. Shamji, F. R.K. Matzinger, and D. G. Perkins Surgical staple metalloptysis after apical bullectomy: a reaction to bovine pericardium? Ann. Thorac. Surg., July 1, 2002; 74(1): 258 - 261. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
