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Ann Thorac Surg 1997;64:313-319
© 1997 The Society of Thoracic Surgeons
Departments of Surgery, Internal Medicine, and Radiology, University Hospital, Zurich, Switzerland
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Abstract |
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 TopFootnotes Abstract IntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
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Methods. The preoperative chest computed tomograms in 50 consecutive patients who had undergone surgical lung volume reduction were retrospectively reviewed by 6 physicians blinded to the clinical outcome. Emphysema morphology was determined according to a simplified classification (ie, homogeneous, moderately heterogeneous, and markedly heterogeneous; lobe predominance). We studied the impact of these morphologic aspects on functional outcome at 3 months.
Results. We found a fair interobserver agreement applying our classification system. Functional improvement after surgical lung volume reduction was best in markedly heterogeneous emphysema with an increase in forced expiratory volume in 1 second of 81% ± 17% (mean ± standard error; n = 17) compared with 44% ± 10% (n = 16) for intermediately heterogeneous emphysema. But also in patients with homogeneous emphysema clinical relevant improvement of function could be observed (increase in forced expiratory volume in 1 second = 34% ± 6%; n = 17).
Conclusions. The morphologic type of emphysema, assessed by a simplified surgically oriented classification, is an important predictor of surgical outcome. Lung volume reduction surgery may also improve dyspnea and lung function in homogeneous emphysema.
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Introduction |
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TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
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Lung volume reduction surgery (LVRS), performed bilaterally either by median sternotomy [1, 2] or by video-assisted thoracoscopy [3, 4], improves dyspnea, lung function, and quality of life in selected patients with advanced pulmonary emphysema. Appropriate patient selection has been stressed by several authors [3, 5] and includes clinical features and physiologic parameters as well as morphologic aspects such as type, severity, and distribution of emphysema. Many groups preferentially select patients with marked differences in the severity of emphysema in their lungs, ie, with distinct areas of destroyed parenchyma besides relatively well preserved lung tissue. They argue that those parts of the lung that are most severely affected and can be identified by computed tomography (CT) and lung perfusion scan should be chosen as target areas for resection.
However, we made the observation that patients with a homogeneous type of emphysema experienced clinically relevant functional improvements after LVRS as well [4]. Therefore, we wondered how relevant the aspect of emphysema morphology might be in the prediction of functional outcome after operation. These issues were recently addressed by Slone and Gierada [6], who showed good correlations between certain aspects of morphology and functional outcome. Favorable radiologic features included marked heterogeneity of emphysema, particularly upper lobe predominance accompanied by mildly affected lung areas and the presence of compressed lung. This group proposed a sophisticated classification system of emphysema morphology considering specific aspects of LVRS. However, up to now this method of morphologic classification seems not to be broadly applied by other groups presumably because it is relatively complex. Emphysema severity and distribution may also be assessed by quantitative CT densitometry of the lungs, but this computer-assisted analysis may not be available in many centers.
The goal of our retrospective study was twofold: (1) to define a simple, CT-based radiologic emphysema classification that can be reproducibly applied by clinicians involved in LVRS and (2) to evaluate whether this pragmatic classification identifies certain morphologic types of emphysema that predict a more favorable clinical outcome after LVRS than others.
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Material and Methods |
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TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
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1-antitrypsin deficiency. They were evaluated and enrolled in a prospective study on outcome after LVRS as previously described [4]. Briefly, inclusion criteria were severe airflow obstruction (FEV1 < 1.2 l) and hyperinflation (TLC > 130% predicted), dyspnea at rest or on minimal exertion, and smoking cessation. Principal exclusion criteria were hypercapnia (arterial carbon dioxide tension > 55 mm Hg), a low diffusing capacity for carbon monoxide (<20% predicted), and significant symptomatic coronary artery heart disease. Patients with bullae 7 cm or more in diameter were excluded from the study. All patients had been treated with appropriate doses of bronchodilators and had received at least one trial with systemic corticosteroids without response. No systematic rehabilitation was performed before or after the operation.
Methods
FUNCTIONAL AND RADIOLOGIC EVALUATION.
Pulmonary function testing was performed after inhalation of two puffs of salbutamol, adhering to standard criteria [7, 8], with the Sensor Medics 6200 Autobox (Yorba Linda, CA). Reference values were according to the European Community for Steel and Coal [7, 9]. For assessment of 6-minute walking distance, the patients walked along the same hospital hallway without oxygen supplementation.
Dyspnea was rated according to the American Thoracic Society modified Medical Research Council dyspnea score [10]. The patient describes his or her degree of dyspnea by grading with an integer from 0 to 4. Zero means breathlessness only with strenuous exercise, 4 means that the patient is unable to leave the house or is breathless when dressing.
Computed tomographic examinations were performed on a Somatom plus 4 (Siemens, Erlangen, Germany) scanner with high-resolution technique (43 of 50 studies) using an increment of 15 mm and slice thickness of 1 mm at 140 kV and 11 mA. Scan time for each section did not exceed 1 second. In 7 patients conventional spiral CT examinations (8-mm collimation, 140 kV, 206 mA) with application of an intravenous contrast agent were performed.
Pulmonary function tests, arterial blood gas analysis, 6-minute walking tests, and Medical Research Council dyspnea scores were performed before and 3 months after the operation.
SURGICAL TECHNIQUE.
Surgical lung volume reduction was performed bilaterally by video-assisted thoracoscopy as described previously [4]. The "target areas" were identified on CT scans and perfusion scintigrams and the resection was aimed at the most destroyed tissue using nonbuttressed endoscopic staplers (Endo-GIA 30 and 60, Auto-Suture, and, more recently, ELC45, Ethicon Endo-Surgery, Cincinnati, OH). In some cases, target areas could be visualized by observation of delayed resorption atelectasis. A cumulative volume of approximately 20% to 30% of the lung volume on each side was resected. In cases with no "target areas" (homogeneous type), the resection was performed mostly in the upper lobes. Two chest tubes were inserted on each side and connected to suction between 10 and 20 cm H2O, and in the more recent cases to Heimlich valves.
MORPHOLOGIC ASSESSMENT (COMPUTED TOMOGRAPHIC GRADING SYSTEM).
We defined three main morphologic types based on analysis of the chest CT scan. This simplified grading system was chosen according to the surgeon's view to identify parts of the lung that were more destroyed by emphysema (target areas) with respect to resection. The following definitions were applied (Fig 1
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Intermediately heterogeneous: a distinct regional difference in severity of emphysema may be present maximally in the area of one or more than one but not in adjacent lung segments of either lung.
Homogeneous: no regional or only very minor differences in the severity of emphysema are appreciable.
The following features were assessed in addition for heterogeneous cases:
Predominant upper lobe type: emphysema is preferentially located in the upper lobe with or without involvement of the apical segment of the lower lobe.
Predominant lower lobe type: emphysema is preferentially located in the lower lobe and may or may not involve the lingula or the middle lobe, respectively.
Bullae: one or few single bullae are additionally present with a diameter of less than 7 cm.
A visual analogue scale for rating of the degree of emphysema heterogeneity was also employed. The examiner had to set a mark onto a straight line printed on a sheet of paper. The relative location of the mark with respect to the two end points of the line, labeled homogeneous and heterogeneous, respectively, represented the degree of heterogeneity. The distance from the point labeled homogeneous to the mark was measured and expressed as a percentage of the total length of the line.
Lung windows of the chest CT scans were analyzed by 6 physicians. The patient's names on the CT scans were covered with tape and no clinical information was provided to the examiners. In an initial session, the scoring criteria were defined and some representative examples for each category demonstrated to all examiners. Then, each of them individually scored the first 28 CT scans. After the results were recorded, a consensus was obtained for all scans for which scoring was not unanimous. Subsequently, a second set of 22 CT scans was scored individually by each examiner. After the results were recorded, a consensus was obtained for scans that were not assessed unanimously.
DATA ANALYSIS.
Results of the radiologic scoring were compared with clinical data by calculating mean values and standard error for pulmonary function parameters, 6-minute walking distance, and modified Medical Research Council dyspnea score for the groups of patients with homogeneous, intermediately heterogeneous, and markedly heterogeneous emphysema types. Analysis of variance followed by the Newman-Keuls multiple comparisons procedure, where appropriate, was performed to detect significant differences in preoperative versus postoperative values within the same group, and in values between groups. The association of radiologic findings with preoperative clinical data and with their changes after operation were quantified by coefficients of correlation. For models that used the ordinal radiologic grading (homogeneous, intermediately heterogeneous, and markedly heterogeneous) as the independent variable, the Spearman r was calculated, for interval data the Pearson product moment correlation. The 
2 test was used to compare expected versus observed frequencies. Interobserver agreement was assessed by counting the number of observers with identical ordinal rating (homogeneous, intermediately and markedly heterogeneous) in the first and second scoring session, and by calculation of coefficients of variation in visual analogue scale ratings. A probability of p less than 0.05 was considered as statistically significant.
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Results |
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TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
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). However, if the volumes were expressed as percentage of the predicted values, differences between the groups were not statistically significant with exception of TLC, which was less elevated in the group with marked emphysema heterogeneity. The residual volume to total lung capacity ratio (RV/TLC) of patients with homogeneous emphysema was more elevated than in patients with markedly heterogeneous emphysema. Arterial blood gas analysis revealed mild to moderate hypoxemia (see Table 1), with 6 patients fulfilling criteria for oxygen therapy (arterial oxygen tension < 55 mm Hg). In heterogeneous emphysema, the areas of most destroyed lung were predominantly located in the upper lobes (Table 2).
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). The effect of operation on FEV1 (in liters and in percentage of predicted values) and on FVC (in liters) was most pronounced in the group with markedly heterogeneous emphysema (Figs 2, 3). Arterial partial pressures for oxygen were slightly increased, and 3 months after the operation only 2 patients fulfilled criteria for oxygen therapy (arterial oxygen tension < 55 mm Hg) as compared with 6 patients preoperatively. Mean ± standard deviation drainage time was 10 ± 6 days, and mean hospital stay was 16 ± 9 days. The latter varied considerably and was influenced not only by the medical condition but to a significant degree by individual social circumstances of the patients. At the 3-month follow-up all patients lived in their private homes.
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Ordinal and visual analogue heterogeneity ratings were significantly but moderately correlated with changes in FVC (in liters), FEV1 (in liters and percentage of predicted value, the latter for visual analogue scale only), and RV (percent predicted) (Table 3). On the other hand, preoperative FEV1 (percentage of predicted value) was moderately correlated with relative changes in FEV1.
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). Agreement was closest for homogeneous and markedly heterogeneous emphysema types. Agreement was similar for the first set versus the second set of CT scans (Table 5).
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Comment |
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TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
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Emphysema is defined anatomically. In its severe form it can be easily detected on a plain posteroanterior and lateral chest radiograph and is most reliably assessed by a high-resolution CT scan. Based on correlations found between certain morphologic aspects and functional outcome, Slone and Gierada [6] proposed a sophisticated radiologic scoring system, which combines graded severity of hyperinflation, heterogeneity, and localization of emphysema. To obtain a CT-morphologic classification system that better reflects the surgeon's needs to plan the site and amount of lung resection we designed a simplified surgically oriented emphysema scoring system comprising only three main morphologic categories of emphysema: homogeneous, intermediately heterogeneous, and markedly heterogeneous based on differences in the extent of lung destruction in adjacent lung segments. In addition, we employed a visual analogue scale that allows grading of emphysema heterogeneity on a continuous rather than on an ordinal scale. Our CT-based grading of emphysema is simple and reproducible and does not require specialized training. This is demonstrated by the fair interobserver agreement among five clinicians and a radiologist involved in the selection of patients undergoing LVRS.
The mean preoperative FEV1 (expressed in liters) was highest in the group with marked emphysema heterogeneity. This is probably related to the male predominance in this group (16 of 17 patients versus 10 of 16 in the intermediately heterogeneous and 9 of 17 in the markedly heterogeneous group, respectively). However, the severity of bronchial obstruction, assessed by the FEV1 as percentage of the predicted value, was similar within the three groups (see Table 1). That the degree of hyperinflation, as assessed by the RV, TLC, and their ratio (RV/TLC), was somewhat less than in the other two groups may reflect the application of more stringent functional selection criteria for LVRS in patients with less than marked emphysema heterogeneity (see Fig 3).
Although patients in all three groups of emphysema morphology showed significant improvements in airflow obstruction and hyperinflation after LVRS, the extent of mean improvement in outcome parameters was clearly most pronounced in patients with markedly heterogeneous emphysema (eg, FEV1 by 81%). This principally confirms retrospective observations by the Washington University Emphysema Surgery Group [6, 11]. However, there was a wide scatter in changes of the FEV1 and the RV/TLC ratio, and in about half of the patients the improvements were comparable with those in the other two groups (see Figs 2, 3). In contrast to Slone and Gierada [6] we did not observe an association of lobar distribution of heterogeneity with functional outcome. This might be due to the relatively small number of patients with lower lobe predominance of emphysema (see Table 2). The major finding of our study consists in the observation that even in patients with a completely homogeneous type of emphysema shortness of breath decreases and pulmonary function improves postoperatively (postoperative FEV1 = 34%). Although the average changes of airflow obstruction and pulmonary hyperinflation are less impressive than in the group with markedly heterogeneous emphysema, they are comparable with the changes observed in the intermediately heterogeneous emphysema group (postoperative FEV1 = 44%) (see Fig 2).
When studying correlations between emphysema morphology and functional outcome after LVRS an important aspect has to be taken into consideration. Although the surgeon aims at resecting between 20% and 30% of the volume of each lung, no reliable method is available to quantify the amount of volume that is reduced during the operation. Weighing the removed lung pieces that are squeezed through a trocar does not seem to overcome this problem. Therefore, in contrast to pharmacologic interventions, which can be quantitatively conducted and individually tailored, the "dosage" of surgical lung volume reduction cannot be truly standardized. This and only scarce information on emphysema morphology in patients who underwent LVRS impose a limitation to the comparison of functional results between different centers and even within the same institution. Furthermore, a certain bias in patient selection toward proposing LVRS preferentially to candidates with more heterogeneous emphysema may have influenced our results as well as those of other retrospective studies [2, 6, 11]. Prospective confirmation of these findings is therefore required.
In conclusion, we propose a simple, surgically oriented classification of emphysema that identifies patients with homogeneous, intermediately heterogeneous, and markedly heterogeneous disease, the latter being associated with the most favorable clinical outcome after LVRS. Additionally, we found that the majority of patients with completely homogeneous emphysema experienced significant subjective and functional benefit after LVRS. Therefore, emphysema homogeneity can no longer be considered generally as a contraindication for this type of operation. These findings may have major impacts on the selection and number of potential candidates for LVRS. Our results further imply that assessment of the effects of LVRS has to account for the morphologic type of emphysema.
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Acknowledgments |
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TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
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Footnotes |
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TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
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Address reprint requests to Dr Weder, Department of Surgery, University Hospital, Raemistrasse 100, CH-8091 Zurich, Switzerland.
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|
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|
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