Comparison of Water Seal and Suction After Pulmonary Lobectomy: A Prospective, Randomized Trial

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1 GENERAL THORACIC Comarison of Water Seal and Suction After Pulmonary Lobectomy: A Prosective, Randomized Trial Alessandro Brunelli, MD, Marco Monteverde, MD, Alessandro Borri, MD, Michele Salati, MD, Rita D. Marasco, MD, Majed Al Refai, MD, and Aroldo Fianchini, MD Deartment of Resiratory Diseases, Unit of Thoracic Surgery, Umberto I Regional Hosital, Ancona, Italy Background. The objective of the resent study was to assess whether lacing chest tubes on water seal after ulmonary lobectomy reduced the duration of air leak comared with suction. Methods. One hundred forty-five atients who underwent ulmonary lobectomy for lung cancer and with an air leak on the first ostoerative day were rosectively randomly assigned to two grous: in grou 1 (72 atients), chest tubes were laced on water seal on the morning of the first ostoerative day; in grou 2 (73 atients), chest tubes were on continuous suction ( 20 cm H 2 O). Eighty ercent of the atients who underwent uer lobectomy had also a leural tent rocedure. Preoerative, oerative, and ostoerative variables were comared between the grous. Results. The two grous were evenly matched for reoerative and oerative characteristics. No statistically significant differences were found between grou 1 and grou 2 in terms of air leak duration (6.5 versus 6.3, resectively; 0.9) and the incidence of rolonged air leak cases (27.8% versus 30.1%, resectively; 0.8). Similar results were obtained when the analysis was corrected for the length of the staled arenchyma and the site of resection (uer and lower resections) or restricted to atients with a forced exiratory volume in 1 second less than 80% of redicted. Water seal atients had increased ostoerative comlications comared with suction atients (31.9% versus 17.8%, resectively; 0.056). Conclusions. Chest tubes laced on water seal after ulmonary lobectomy were generally well tolerated and safe; however, they did not reduce the duration of air leak or the incidence of rolonged air leak comared with suction. (Ann Thorac Surg 2004;77:1932 7) 2004 by The Society of Thoracic Surgeons Prolonged air leak after lung resection is still one of the most frequent comlications that may rolong the need for chest tubes and hositalization, and negatively imact on hosital costs. Recently, different rosective trials including series of atients undergoing mixed rocedures (wedge resections, segmentectomies, lobectomies) have shown that alying water seal to chest tubes after lung resection reduced the duration of air leak comared with suction [1 3]. The objective of this rosective randomized study was to verify whether water seal chest tubes drainage reduced the duration of air leak comared with chest tubes laced on suction in atients undergoing ulmonary lobectomy for lung cancer. Patients and Methods Acceted for ublication Dec 10, Address rerint requests to Dr Brunelli, Via S. Margherita 23, Ancona 60129, Italy; alexit_2000@yahoo.com. Two hundred sixty-nine atients underwent ulmonary lobectomy or bilobectomy for nonsmall cell carcinoma (NSCLC) at our institution from June 2001 through August 2003 and were enrolled in the study after informed consent. Patients who underwent chest wall resection and broncholastic rocedures were excluded from the analysis. Resectability was evaluated by means of comuted tomograhy (CT) scan, bronchoscoy, and, when indicated, mediastinoscoy. We assessed oerability by means of arterial blood gas analysis, ulmonary function tests, electrocardiogram, echocardiograhy, and more invasive cardiologic tests if needed. A symtom-limited stair-climbing test was systematically administered for risk stratification to all atients who were able to erform it. Oerative exclusion criteria were a redicted ostoerative forced exiratory volume in 1 second (ofev 1 ) less than 30% in association with a height lower than 12 m reached at the stair-climbing test, and a hemodynamically unstable state. All ulmonary lobectomies were erformed at a single institution by one of four attending thoracic surgeons through a lateral muscle-saring thoracotomy. The oerative technique was standardized for all the surgeons. We used mechanical stalers to develo incomlete fissures in 80% of atients and to close the bronchus in all atients in the study. Aroximately 20% of atients had 2004 by The Society of Thoracic Surgeons /04/$30.00 Published by Elsevier Inc doi: /j.athoracsur

2 Ann Thorac Surg BRUNELLI ET AL 2004;77: WATER SEAL AND LOBECTOMY comletely develoed or filmy fissures, which did not require the use of stalers. After comletion of the lobectomy, a mediastinal lymhadenectomy was erformed in all atients. After reinflation of the oerated lung, air leaks were inointed by squirting sterile water over the lung and sutured. Uer lobectomies and bilobectomy atients underwent a leural tent rocedure, whenever ossible (with the excetion of extraleural resection), according to the technique reviously described [4]. Aroximately 80% of uer lobectomies in this series had leural tenting. Two 28F chest tubes were ositioned before the closure of the thoracotomy, one anteriorly into the aex and one in a osteroinferior osition. During the immediate ostoerative eriod, we laced the chest tubes on suction ( 20 cm H 2 O) until the morning of the first ostoerative day, at which time the atients without an air leak were managed with water seal chest tubes and were not included in the resent analysis. Patients with an air leak resent on the morning of the first ostoerative day were randomly assigned to one of two grous: in grou 1, the chest tubes were laced on water seal; in grou 2, the chest tubes remained on continuous suction ( 20 cm H 2 O), with the excetion of transfers within the hosital, until no air leak was evident. If an air leak ersisted for more than 10 days, we converted the chest tubes to water seal, and then after 24 hours we connected them to a Heimlich valve and discharged the atients unless otherwise contraindicated. Of the atients in the two grous, 3 atients died and 3 atients required mechanical ventilation for more than 24 hours and were, therefore, excluded from the analysis. Thus, a total of 145 atients (28 female, 117 male) with an air leak on ostoerative day 1 formed the dataset of the resent study (grou 1, water seal, 72 atients; grou 2, suction, 73 atients). The following rocedures were erformed for each grou: grou 1, 23 right uer lobectomies, 19 left uer lobectomies, 14 left lower lobectomies, 8 right lower lobectomies, 5 right lower bilobectomies, 2 middle lobectomies, and 1 right uer bilobectomy; grou 2, 24 left uer lobectomies, 20 right uer lobectomies, 10 left lower lobectomies, 7 right lower lobectomies, 7 right lower bilobectomies, 3 middle lobectomies, and 2 right uer bilobectomies. The resence of an air leak was checked twice daily during morning and evening rounds. The atients were instructed to make reeated efforts of forced exiration and cough in order to reveal the resence of an air leak. We elected to not erform chest radiograhs routinely and to obtain them only when clinically indicated (reduced breath sounds at auscultation, increased bronchial secretions, fever with leukocytosis, reduced oxygen saturation, a susicion of chest tube malfunctioning, and so forth). This is a standard olicy at our institution. Therefore, a systematic study on the occurrence of residual leural saces was not ossible [1, 2]. During the ostoerative eriod, chest hysiotheray and incentive sirometry were administered to all atients, in addition to bronchodilators if needed. We 1933 removed the chest tubes when no air leak was evident (after a 24-hour claming trial), and when the leural effusion was less than 200 ml in 24 hours. This olicy of chest tube removal is the current standard ractice at our institution. For the urose of this study, an air leak that ersisted for more than 7 days was arbitrarily termed rolonged. Two different tyes of drainage aaratuses were used during the eriod of the study. As one of the two tyes of drainage device did not have a leak-meter, a quantitative analysis of the air leak was not ossible in this study. The two tyes of drainage aaratuses were evenly distributed between the grous. Furthermore, we tested them by means of a water-manometer to assure that a negative ressure of 20 cm H 2 O was alied to the chest tubes. For the urose of the resent study, a concomitant cardiac disease was defined as follows: revious cardiac surgery, revious myocardial infarction, history of coronary artery disease, and current treatment for hyertension, arrhythmia, or cardiac failure. As a measure of comorbidity, we used the Charlson comorbidity index [5]. The following comlications, occurring within 30 ostoerative days (or over a longer eriod if the atients remained hositalized), were considered for the analysis: atelectasis requiring bronchoscoy, neumonia, ulmonary edema, adult resiratory distress syndrome, ulmonary embolism, leural emyema, cardiac failure, arrhythmia requiring medical treatment, myocardial infarction, acute renal failure, and stroke. Statistical Analysis The samle size of this study was set to obtain a statistical ower of 0.99 for detecting an exected difference of air leak duration of 2 days between the grous (according to the mean difference reorted by Marshall and associates [2]) with a two-tailed significance level of The Shairo-Wilk test of normality and the standardized normal robability lot were used to evaluate the normal distribution of the numerical variables. The numerical variables with a normal distribution were comared by means of the unaired Student s t test. Those without a normal distribution were comared by means of the Mann-Whitney test. The 2 test or the Fisher s exact test, when aroriate, were used to comare categorical variables. The following reoerative variables were considered: the atient s age and sex, FEV 1, forced exiratory caacity (FVC), FEV 1 /FVC ratio, redicted ostoerative FEV 1 (ofev 1 ), residual volume to total lung caacity ratio (RV/TLC ratio), carbon monoxide diffusion lung caacity (DLCO), arterial oxygen tension (PaO 2 ), arterial carbon dioxide level (PaCO 2 ), reoerative hemoglobin and serum albumin concentrations, neoadjuvant chemotheray, smoking history (ack-years), and use of systemic steroids. The FEV 1, FVC, ofev 1 and DLCO were exressed as a ercentage of redicted value for age, gender and height according to the Euroean Community for Steel and Coal rediction equations [6]. The ofev 1 was calculated based on the functioning segments removed during oeration, and it was estimated GENERAL THORACIC

3 GENERAL THORACIC 1934 BRUNELLI ET AL Ann Thorac Surg WATER SEAL AND LOBECTOMY 2004;77: by CT scan and bronchoscoy [7]. If the calculated ofev 1 was less than 50% of the redicted value, a quantitative lung erfusion scan was erformed [8]. The DLCO was measured by the single-breath method. We comuted the number of ack-years of smoking as the total number of years smoked multilied by the average number of cigarettes smoked er day, divided by 20. Oerative variables included the side (right and left) and site (uer and lower) of resection, the resence of leural adhesions and the length of the staled arenchyma (cm). For the urose of this study, we classified the following rocedures as uer resections: right and left uer lobectomies, right uer bilobectomy and middle lobectomy. Lower resections included right and left lower lobectomies, and right lower bilobectomy. Only dense leural adhesions occuying more than 30% of a lobe or more than one lobe were taken into consideration for the analysis. We measured the length of the staled arenchyma using the length of the staler cartridges used on the deflated lung. Postoerative variables included the duration of air leak in days, the resence of a rolonged air leak (rolonged air leak), the duration of chest tube use in days, the quantity of leural effusion during the first ostoerative 48 hours, the resence of other comlications, the length of ostoerative hosital stay in days, the corrected duration of air leak, and chest tube time er centimeters of staled arenchyma [2]. To assess whether lacing the chest tubes on water seal influenced the rate of reduction of ostoerative air leak comared with suction, we comared the reduction in the number of atients with air leak occurrence in successive ostoerative eriods ( 2 days, 4 days, 6 days, 8 days, and 10 days). All test were two-tailed, with a significance level of 0.05, and were erformed on the statistical software Statview 5.0 (SAS, Cary, NC). Results Table 1 shows that the two grous were evenly matched for reoerative and oerative variables. Only 1 atient in the water seal grou received reoerative systemic steroids; no atients in the suction grou received reoerative systemic steroids. As shown in Table 2, the differences in air leak duration, resence of rolonged air leak, days required for chest tubes removal, and length of ostoerative hosital stay were not statistically significant between the two grous. Even when the air leak duration was corrected for the length of the staled arenchyma, no difference was noted between the grous. In atients with comlete fissures that did not need the use of stalers, no differences were noted between the water seal and the suction grous in terms of air leak duration (8.0 versus 6.1, resectively; 0.9), chest tube duration (12.5 versus 10.0, resectively; 0.7) and length of ostoerative hosital stay (11.3 versus 10.9, resectively; 0.9). The chest tubes laced on water seal were generally well tolerated, although 2 atients with large air leaks Table 1. Comarison Between Two Grous in Terms of Preoerative and Oerative Grou 1 72 Patients Grou 2 73 Patients Age 67.9 (8.8) 68.8 (9.6) 0.3 b Sex (male, %) 84.7% 76.7% 0.2 a PaO 2 (mm Hg) 79.2 (12.1) 81.0 (9.8) 0.4 PaCO 2 (mm Hg) 37.7 (4.3) 37.4 (3.9) 0.7 FEV (18.8) 87.8 (19.3) 0.2 FVC 95.6 (16.8) 95.7 (18.5) 0.9 FEV 1 /FVC ratio 0.70 (0.10) 0.71 (0.11) 0.8 RV/TLC ratio 0.43 (0.09) 0.45 (0.08) 0.2 ofev (15.7) 69.1 (14.8) 0.6 D L CO 76.3 (22.1) 70.7 (15.0) 0.06 b Preoerative hemoglobin 14.1 (1.8) 13.6 (1.8) 0.2 (g/dl) Serum albumin (g/dl) 4.1 (0.4) 4.2 (0.4) 0.2 Neoadjuvant chemotheray 9 (12.5%) 6 (8.2%) 0.4 a Pack-years of smoking 41.0 (21.4) 41.1 (28.9) 0.9 Side of resection (right, %) 54.2% 53.4% 0.9 a Site of resection (uer, %) 62.5% 67.1% 0.6 a Pleural adhesions (%) 37.5% 43.8% 0.4 a Staler length (cm) 72.8 (50.0) 69.9 (57.4) 0.5 b a Chi-square test; b Mann-Whitney two-samle test. Staler length is the length of the staled arenchyma. Results are exressed as mean ( / standard deviation) unless otherwise secificed. D L CO diffusing caacity of lung for carbon monoxide; FEV 1 forced exiratory volume in 1 second; FVC forced vital caacity; o redicted ostoerative; RV/TLC residual volume to total lung caacity ratio. needed to be converted on suction for the develoment of severe subcutaneous emhysema and oxygen desaturation, which imroved on suction. Both atients were laced back on water seal 24 hours later. Patients with chest tubes on water seal had an increased rate of ostoerative cardioulmonary comlications (31.9% versus 17.8%, 0.056, Fisher s exact test). In articular, they had a trend of increased incidence of neumonia (13.9% versus 6.8%, 0.18, Fisher s exact test) and arrhythmia (13.9% versus 5.5%, 0.10, Fisher s exact test). In the two grous, a similar roortion of atients had a concomitant cardiac disease (water seal, 59.8% versus suction, 46.6%; Fisher s exact test, 0.15) and diabetes (water seal, 11.1% versus suction, 11.0; Fisher s exact test 0.99). Furthermore, the Charlson comorbidity index did not differ between the water seal and the suction grous (2.3 versus 2.5; 0.5). No atients in either grou required a chest tube reinsertion after removal. Tables 3 and 4 show the results of the comarison between atients with water seal and suction chest tubes stratified according to the site of resection. Either in uer and lower resection, no differences were noted between the two grous in terms of air leak duration and occurrence of rolonged air leak. In each of these subgrous, the atients on water seal and those on suction

4 Ann Thorac Surg BRUNELLI ET AL 2004;77: WATER SEAL AND LOBECTOMY Table 2. Results of Comarison Between the Two Grous in Terms of Postoerative Grou 1 72 Patients Grou 2 73 Patients Table 4. Results of Comarison Between the Two Grous in Terms of Postoerative After Lower Resections Grou 1 27 Patients Grou 2 24 Patients 1935 GENERAL THORACIC Air leak duration Chest tube duration Pleural effusion at 48 hours (ml) Prolonged air leak Postoerative hosital stay Air leak days/cm of Chest tube days/cm Other comlications 6.5 (7.5) 6.3 (7.2) 0.9 b 11.5 (8.3) 10.3 (7.6) 0.2 b (458) (362) 0.4 b 20 (27.8%) 22 (30.1%) 0.8 a 11.5 (5.5) 11.6 (8.5) 0.3 b 0.08 (0.09) 0.11 (0.19) 0.9 b 0.14 (0.12) 0.17 (0.21) 0.7 b 23 (31.9%) 13 (17.8%) c a Chi-square test; b Mann-Whitney two-samle test; c Fisher sexact test. Results are exressed as mean ( / standard deviation) unless otherwise secified. were evenly matched for reoerative and oerative characteristics. When the comarison between the two grous was restricted to the atients with a FEV 1 less than 80% of redicted (27 atients in grou 1 and 22 in grou 2, evenly matched for reoerative and oerative characteristics), no differences were noted in terms of air leak duration (8.0 versus 7.1, resectively; 0.7), incidence of rolonged air leak (44.4% versus 36.4, resectively; 0.8 with the Fisher s exact test), duration of chest tubes (13.6 versus 11.9, resectively; 0.5), ostoerative Table 3. Results of Comarison Between the Two Grous in Terms of Postoerative After Uer Resections Air leak duration Chest tube duration Pleural effusion at 48 hours (ml) Prolonged air leak Postoerative hosital stay Air leak days/cm of Chest tube days/cm Grou 1 45 Patients Grou 2 49 Patients 7.1 (7.8) 5.9 (6.7) 0.5 b 11.9 (9.0) 10.2 (7.7) 0.3 b (434) (327) 0.9 b 15 (33.3%) 16 (32.7%) 0.9 a 11.8 (5.9) 11.7 (9.6) 0.2 b 0.08 (0.09) 0.10 (0.20) 0.7 b 0.14 (0.13) 0.16 (0.22) 0.9 b a Fisher s exact test; b Mann-Whitney two-samle test. Results are exressed as mean ( / standard deviation) unless otherwise secified. Air leak duration Chest tube duration Pleural effusion at 48 hours (ml) Prolonged air leak Postoerative hosital stay Air leak days/cm of Chest tube days/cm hosital stay (12.6 versus 12.1, resectively; 0.7), corrected duration of air leak er centimeter of staled arenchyma (0.09 versus 0.15, resectively; 0.4). Finally, Table 5 shows that the rate of the reduction of air leak was not statistically different in the two grous. The atients in grou 2 with an air leak lasting for more than 10 days were converted to water seal and eventually discharged with a Heimlich valve. They did not show any difference in terms of air leak duration, comared with the atients in grou 1 (18.6 versus 19.3, resectively; 0.8). Comment 5.4 (6.8) 7.0 ( b 10.8 (7.2) 10.6 (7.6) 0.6 b (497) (432) 0.3 b 5 (18.5%) 6 (25.0%) 0.6 a 11.1 (5.0) 11.3 (5.6) 0.9 b 0.08 (0.09) 0.12 (0.15) 0.5 b 0.15 (0.09) 0.18 (0.18) 0.4 b a Fisher s exact test; b Mann-Whitney two-samle test. Results are exressed as mean ( / standard deviation) unless otherwise secified. The objective of this study was to assess whether lacing the chest tubes on water seal reduced the air leak duration comared with suction in atients who underwent ulmonary lobectomy for lung cancer. Tradition- Table 5. Number of Patients Without Air Leak at Successive Postoerative Intervals Postoerative Period Cases Without Air Leak Water Seal (n 72) Suction (n 73) Percent of Air Leak Reduction a Water Seal Suction 2 days % b 20.5% b days % 41.1% days % 20.6% days % 14.8% days % 21.7% 0.9 a Percent of air leak reduction with resect to the revious eriod; b Cases without air leak with resect to the total number of atients in each grou. Fisher s exact test was used.

5 GENERAL THORACIC 1936 BRUNELLI ET AL Ann Thorac Surg WATER SEAL AND LOBECTOMY 2004;77: ally, thoracic surgeons have laced chest tubes on suction after lung resection until no air leak was evident. More recently, it has been suggested that in atients with severe emhysema undergoing lung volume reduction surgery, lacing the chest tubes on water seal reduced the incidence of rolonged air leak [9, 10]. This concet has been verified also in atients undergoing ulmonary resections other than lung volume reduction surgery by two rosective randomized trials [1, 2]. These studies showed that water seal was effective in reducing the duration of air leak. However, a mix of rocedures including wedge resections, segmentectomies, and lobectomies were studied in series of atients oerated on for both lung metastases and rimary lung cancer. Theoretically, lacing chest tubes on suction imroves the aosition of the visceral and arietal leurae, facilitating the sealing of air leaks. This aroach seems more reasonable articularly after a ulmonary lobectomy when a greater leural residual sace is created comared with minor resections. On the other hand, the suction alied to the tubes may lead to an increase in the volume of air leaking from the arenchyma, hindering the sealing rocess [2]. Therefore, we wanted to test the alication of water seal on the chest tubes of a homogeneous series of atients undergoing ulmonary lobectomy for NSCLC. Our results showed that, comared with suction, water seal did not reduce the duration of air leak, the incidence of rolonged air leak, and the length of hosital stay in these atients. Even when the analysis was corrected for the length of the staled arenchyma [2], stratified for the site of resection (uer and lower) or restricted to atients with a FEV 1 less than 80% of redicted (resumably with a more damaged and fragile lung arenchyma), no significant differences between the grous were noted in terms of air leak duration. These results are in contrast with those reorted by Cerfolio and colleagues [1] and Marshall and associates [2]. Differences in the size of the samles (18 atients with lobectomy in the water seal grou of Cerfolio and coworkers; 15 atients with lobectomy in the water seal grou of Marshall and coworkers), in the study rotocol (water seal alied on the second ostoerative day in the Cerfolio analysis, immediately after the oeration in the Marshall analysis), and in the tye of rocedures included in the study (wedge, segmentectomy, and lobectomy in the two studies cited above; only lobectomy in the resent study) may exlain these different findings. Furthermore, the studies cited above [1, 2] did not stratify the results for the tye of oeration erformed (wedge, segmentectomy, lobectomy), making the comarison between our study and theirs difficult. We laced the chest tubes on suction the day of surgery, since we and our ethical committee considered safe a brief eriod of suction immediately after oeration, as in another trial [1]. We did not think this flawed the results, however, as randomization occurred on the morning of the first ostoerative day and only among the atients with an air leak resent at this time. We think this allowed a reliable estimate of the effect of water seal or suction on air leak duration. More than 55% of our atients on the water seal grou with an air leak on ostoerative day 1 had their air leaks stoed by the fourth ostoerative day. This finding was similar to that reorted by Cerfolio and coworkers (67%) [1]. However, in our suction grou a comarable roortion of atients (53%) had their air leaks stoed by the fourth ostoerative day, comared with only 7% of the atients in the Cerfolio study [1]. That may be exlained in art by the fact that we erformed routinely a leural tent in uer lobectomies and bilobectomies whenever ossible. We and other authors reviously showed that this rocedure was effective in reducing the duration of air leak [11 13]. Therefore, the rate of reduction of air leak in our study was not influenced by the modality of the chest tube management. Another interesting finding was that, although water seal was generally safe and well tolerated by our atients who were able to ambulate early and more freely, a trend toward increased morbidity was noted in this grou. In articular, atients in the water seal grou had an incidence of neumonia and arrhythmia twice as high as the atients in the suction grou. Whether these comlications were related to a reduced lung exansion, with a consequent increase in sutum retention and hyoxemia, remains a matter of seculation that needs to be verified by other larger trials. In conclusion, even though chest tubes laced on water seal after ulmonary lobectomy were safe and well tolerated, they did not reduce the duration of air leak or the incidence of rolonged air leak. Based on the results of this analysis, our current ractice is to use a moderate suction ( 10 cm H 2 O) overnight and water seal during the day for allowing an early and free mobilization of the atients. Whether this alternate moderate suction chest tube modality rovides an advantage in terms of air leak duration has to be tested by another rosective randomized trial. References 1. Cerfolio RJ, Bass C, Katholi CR. Prosective randomized trial comares suction versus water seal for air leaks. Ann Thorac Surg 2001;71: Marshall MB, Deeb ME, Bleier JIS, et al. Suction vs. water seal after ulmonary resection. A randomized rosective study. Chest 2002;121: Ayed AK. Suction versus water seal after thoracoscoy for rimary sontaneous neumothorax: rosective randomized study. Ann Thorac Surg 2003;75: Brunelli A, Al Refai M, Muti M, Sabbatini A, Fianchini A. Pleural tent after uer lobectomy: a rosective randomized study. Ann Thorac Surg 2000;69: Birim O, Maat APWM, Kaetein AP, van Meerbeeck JP, Damhuis RAM, Bogers AJJC. Validation of the Charlson comorbidity index in atients with oerated rimary non-small cell lung cancer. Eur J Cardiothorac Surg 2003; 23: Quanjer PhH, Tammeling GJ, Cotes JE, Pedersen OF, Peslin R, Yernault JC. Lung volumes and forced ventilatory flows. Reort of Working Party. Standardization of lung function

6 Ann Thorac Surg BRUNELLI ET AL 2004;77: WATER SEAL AND LOBECTOMY tests. Euroean Community for Steel and Coal. Official statement of the Euroean Resiratory Society. Eur Resir J 1993;6(Sul 16): Brunelli A, Fianchini A. Predicted ostoerative FEV1 and comlications in lung resection candidates. Chest 1997;111: Markos J, Mullan BP, Hillman DR, et al. Pre-oerative assessment as a redictor of morbidity, and mortality after lung resection. Am Rev Resir Dis 1989;139: Cooer JD, Patterson GA, Sundaresean RS, et al. Results of 150 consecutive bilateral lung volume reduction rocedures in atients with severe emhysema. J Thorac Cardiovasc Surg 1996;113: Cooer JD, Patterson GA. Lung volume reduction surgery for severe emhysema. Chest Surg Clin North Am 1995;5: Robinson LA, Preksto D. Pleural tenting after uer lobectomy decreases chest tube time and total hositalization days. J Thorac Cardiovasc Surg 1998;115: Okur E, Kir A, Halezeroglu S, Levent Alay A, Atasalihi A. Pleural tent following uer lobectomies or bilobectomies of the lung to revent residual air sace and rolonged air leak. Eur J Cardiothorac Surg 2001;20: Brunelli A, Al Refai M, Monteverde M, et al. Pleural tent after uer lobectomy: a randomized study of efficacy and duration of effect. Ann Thorac Surg 2002;74: GENERAL THORACIC INVITED COMMENTARY Dr Brunelli and colleagues have resented another imortant study on the common roblem of air leaks. This trial is well designed, erformed, analyzed, and written. On the surface, their findings seem to be contrary to the ones Marshall and we have reorted. However careful scrutiny of Brunelli s data actually shows that it may suort the findings in those revious rosective studies. The management of chest tubes is only one way to manage air leaks. Intra-oerative reventative measures rather than ost-oerative management are always more imortant for any ost-oerative comlication. Some intra-oerative techniques include: fissure-less surgery, sealants, buttressing of s, neumoeritoneum, and leural tents. Although chest tube management is imortant in atients with an air leak, the advantage of one chest tube setting over another becomes weakened when air leaks are small. In this study the authors have nicely shown that when a leural tent is used, the setting of the chest tube makes little difference. This is of little surrise. Unfortunately, the reviously reorted classification of air leaks and an air leak meter were not used in this study, but the natural history of the leaks in this series suggests that many were small. When one eliminates the atients who had leural tents, which the authors essentially do for us in Table 4, their own data begin to show the advantages of water seal. The numbers may be too small to show a statistically significant difference but the air leak duration was 5.4 days comared with 7.0 days and the air leak days/cm of was only 0.08 comared with 0.12, both favoring the water seal grou. Thus, erhas a better title for this aer may be Pleural Tents After Uer Lobectomy Negate the Advantages of Placing Chest Tubes on Water Seal. This finding is also not unexected because this grou has already shown the advantage of a leural tent after uer lobectomy in a very well done rosective randomized study that was recently ublished. Finally, why do the authors choose to use water seal in atients who had no air leak and were excluded in this study? We refer suction in these atients since water seal seems to offer no real advantage. Furthermore, I am erlexed as to why they conclude the aer with the statement: Based on the results of this analysis our current ractice is to use moderate suction ( 10 cm H 2 O) overnight and water seal during the day. The authors never even studied 10 cm of suction and found no advantage to water seal and otential harm. Why is this now their referred rotocol? We are indebted to Dr Brunelli and colleagues for once again heightening our awareness of the roblem of air leaks and for a well-done rosective randomized study. Perhas more studies are needed to examine atients who undergo lobectomy only. Their finding that water seal may lead to increased comlications is rovocative. It would be easy to do a rosective randomized trial that only studied atients who underwent lobectomy and to recruit enough atients in the study so one could generate the statistical ower needed to fully assess the advantages and disadvantages of water seal versus suction [1 3]. Robert James Cerfolio, MD, FACS University of Alabama at Birmingham Division of Cardiothoracic Surgery Section of Thoracic Surgery 1900 University Blvd THT Room 712 Birmingham, AL rcerfolio@uab.edu References 1. Marshall MB, Deeb ME, Bleier JIS. Suction versus water seal after ulmonary resection, a randomized rosective study. Chest 2002;121: Cerfolio RJ, Bass C, Katholi CR. A rosective randomized trial comares suction versus water seal for air leaks. Ann Thorac Surg 2001;71: Brunelli A, Al Rafai M, Monteverde M, Borri A, Salati M. Pleural tent after uer lobectomy: a randomized study of efficacy and duration of effect. Ann Thorac Surg 2002;74: by The Society of Thoracic Surgeons /04/$30.00 Published by Elsevier Inc doi: /j.athoracsur