Thoracoscopic laser ablation of pulmonary bullae. Radiographic selection and treatment response.

The purpose of this study was to develop objective preoperative selection methods for predicting outcome in patients undergoing thoracoscopic laser ablation of emphysematous pulmonary bullae. Initial radiographic presentation was correlated with physiologic function both before and after the operation in 24 patients entered into a prospective clinical protocol for evaluation of carbon dioxide laser treatment of emphysematous pulmonary bullae. Nineteen surviving patients underwent follow-up evaluation 1 to 3 months after the operation. Pulmonary function test results showed improvements in spirometry (forced vital capacity increased 0.82 +/- 0.125 L, forced expiratory volume in 1 second increased 0.36 +/- 0.07 L, and maximum voluntary ventilation increased 11.69 +/- 2.6 L/m; p < 0.002); airway resistance decreased by 0.9 +/- 0.35 cm of water/L per second, and specific conductance increased 0.019 +/- 0.006 L/cm H2O per second (p < 0.02). Lung volumes improved (residual volume decreased 1.25 +/- 0.23 L, p < 0.001) without significant change in resting gas exchange. Quantitative radiographic grading of extent of preoperative pulmonary bullae correlated well with response to laser treatment in patients with preoperative and postoperative studies. Patients with large bullae accompanied by crowding of adjacent lung structures, upper lobe predominance, and minimal underlying emphysema had greatest improvement in pulmonary function results with laser bullae ablation (p < 0.05). However, some patients with multiple smaller bullae and diffuse emphysema also demonstrated objective improvement after operation. Quantitative radiographic analysis of the extent of bullous disease and the degree of associated emphysema can be used to determine short-term postoperative pulmonary response and may be useful in selecting future thoracoscopic laser bullae ablation candidates. Additional follow-up will be necessary to further improve selection criteria and help define the long-term role of thoracoscopic laser treatment of bullous emphysema.

Splenic size on routine chest films in AIDS: diagnostic and prognostic significance.

Sixty-nine percent of AIDS patients show evidence of splenomegaly on their plain chest film. This splenomegaly is not related to severity of AIDS, to intravenous drug abuse or to any specific infection or neoplasm but correlates well with severity of anemia, pancytopenia, and thrombocytopenia. Increasing splenomegaly usually indicates worsening of AIDS. The triad of splenomegaly, interstitial lung disease sparing the bases, and very thin chest wall soft tissues is highly specific for the diagnosis of AIDS. The sensitivity of the plain film for diagnosing AIDS can be increased by including AIDS in the differential diagnosis of all patients with splenomegaly, intrathoracic lymphadenopathy, cachexia, or bilateral interstitial lung disease of unknown cause.

Blood supply of pulmonary metastases.

There is a widely held belief that metastases to the lung (like primary lung tumors) are supplied by the bronchial arteries and that pulmonary neovascularization does not occur. In 17 human lungs, we have demonstrated, both in vitro and in vivo, pulmonary circulation to metastases. We have confirmed this in a series of animal studies in which we implanted tumors of various histologies into rats' tails and induced metastases from these tumors into the lungs. Forty-eight percent of these metastases had an entirely pulmonary circulation, 36% a primarily pulmonary circulation with a small bronchial component, and only 16% of metastases, located in the central one third of the lung, had an exclusively bronchial circulation. We have now shown that these supplying pulmonary vessels to metastases can be clearly demonstrated on thin-section computed tomography of the lungs. This may prove to be a helpful, noninterventional diagnostic criterion for distinguishing a primary from a metastatic lesion.

The radiologic distinction of cardiogenic and noncardiogenic edema.

Improvement in the ability to determine the specific cause of any given case of pulmonary edema would lead to more rapid and definitive treatment. "Wedge" pressures and measurements of cardiac output derived from Swan-Ganz catheterization assist in making this determination, but the procedure is invasive, expensive, associated with complications, and not infrequently inaccurate. A plain chest film is, however, almost invariably available in all patients with pulmonary edema, and as shown in this study, the cause of the edema can be determined with a high degree of accuracy by careful attention to certain radiographic features. An independent two-observer study was performed on 216 chest radiographs of 61 patients with cardiac disease, 30 with renal failure or overhydration, and 28 with capillary permeability edema. Three principal and seven ancillary features have been identified, all of which are statistically significant and permit the cause of the edema to be determined correctly in a high percentage of cases. The three principal features are distribution of pulmonary flow, distribution of pulmonary edema, and the width of the vascular pedicle. The ancillary features are pulmonary blood volume, peribronchial cuffing, septal lines, pleural effusions, air bronchograms, lung volume, and cardiac size. Differing constellations of these features occur, each of which is characteristic of a specific type of edema. Overall accuracy of diagnosis in this study ranged from 86% to 89%. The highest accuracy was obtained in distinguishing capillary permeability edema from all other varieties (91%), and the lowest in distinguishing chronic cardiac failure from renal failure (81%).

Pneumomediastinum: a diagnostic problem.

Pneumomediastinum has numerous etiologies and its pathways of spread are multiple and well defined. Knowledge of these anatomic pathways and possible etiologies is important in order to avoid extensive and unnecessary evaluations. For example, if there is a known reason for pneumomediastinum, and pneumoperitoneum is present without associated abdominal findings, further evaluation for perforated viscus is unnecessary. In a patient who is an asthmatic or a diabetic, the presence of pneumomediastinum should not lead to work-up with contrast studies unless there are specific clinical reasons to do so. In critically ill infants and adults, pulmonary interstitial emphysema is an important warning sign for impending pneumothorax or pneumomediastinum and the patient's physicians should be alerted. There are occasional difficulties in differentiating pneumomediastinum from pneumopericardium and from a medial pneumothorax. Analysis of anatomic details and decubitus views are helpful in this regard.

A morphological and quantitative study of tumor blood flow. I. During growth and immune rejection.

We have used serial microangiography and radioactive 133 Xe to study microvascular morphology and quantify blood flow in Walker 256 carcinomas implanted in rat tails during growth and immune rejection. No previous angiographic/quantitative studies during immune rejection are reported. Two tumor groups were identified. Group A grew rapidly, with a two- to six-fold increase in blood flow, and caused death in 10 days. Group B grew more slowly, and increased blood flow two to four times. At 6 to 8 days postimplant the B tumors diminished in size; blood flow decreased and extensive lymphocytic infiltration developed. By 21 days all evidence of the tumor had disappeared. The rejection appears to be cell-mediated, and the high incidence (65-70%) to be related to the number of tumor cells and/or presence of accumulated antigen in the innoculum. Microangiographic changes during immune rejection were specific, and included marked tortuosity of feeding vessels and a "ghostlike" fading out of tumor vessels, quite unlike the appearance of necrosis.

Bile aspiration: an experimental study in rabbits.

It has been shown that bile injected intratracheally in rabbits produces severe pulmonary edema, atelectasis, and focal hemorrhages. The authors investigated the effect of a number of solutions, including physiological concentration of bile, hydrochloric acid pH 1.0, bile salt diluted to 1%, and bile at 100% concentrations. Whenever the bile concentration exceeded 3%, none of the test animals survived. It is not possible to apply directly the results of an experimental animal study to humans. However, the severity of the pulmonary changes produced force the conclusion that bile is a potentially dangerous aspirate in humans.