Surgery: Thoracic

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Surgery, Cardiovascular, continued FACTORS RELATED TO REHOSPITALIZATION WITHIN THIR1Y DAYS OF DISCHARGE AFTER CORONARY ARTERY BYPASS GRAFTING Virginia Beggs, M.S., A.R.N.P., NJ O'Connor, M.S., WC Nugent, M.D., FCCP, GT O'Connor, Ph.D., D.Sc., Dartmouth-Hitchcock Medical Center, Lebanon, NH Purpose: Early re-hospitalization following coronary artery bypass grafting (CABG) is an expensive and common outcome. We performed a study to identifY patient, disease and treatment factors that predict re-hospitalization within 30 days after discharge from CABG surgery. The study population included 1,011 consecutive patients (Oct. 1, 1991-Sept. 30, 1994) receiving CABG surgery at Dartmouth-Hitchcock Medical Center, Lebanon, NH. Methods: We conducted a case-control study. We compared the re-hospitalized patients with non-readmitted control patients. The controls were randomly selected from the same series as the cases and were matched on age ( ±5 years), sex, and priority of surgery (emergency, urgent or elective). Preoperative data, including severity of illness, cardiac catheterization results, and the presence of co-morbid conditions, were available on all patients. Post-operative information, including duration of hospital stay, occurrence of nonfatal complications, patient condition at discharge, and primary diagnoses at re-hospitalization, were obtained. Conditional logistic regression was used to analyze the data. The area under the relative operating characteristics (ROC) curve was used to measure the discriminating ability of the statistical model. Results: Of the 1,011 patients, 139 (13.8%) were re-hospitalized within 30 days. Common reasons for re-hospitalization were: atrial arrhythmias, wound infections and pleural effusions. The llO cases with completed information were matched with 224 control patients. 1n the multivariate analyses the following factors were associated with re-hospitalization: preoperative stay in the Cardiac Care Unit, posterior descending artery stenosis > 70%, post-operative length of stay greater than seven days, and the nee\! for diuretics at discharge. The multivariate model was statistically significant (model CL[df= 7]=34.4, p
sion.

Clinical Implications: The availability of condition-specific, severity-adjusted models to predict the risk of early rehospitalization would help identify patients and processes of care where quality improvement efforts could be directed.

THE MANAGEMENT OF OCCULT PNEUMOTHORAX AFTER BLUNT TRAUMA William S. Hoff, PM Reilly, CL Ketterer, GH Tinkoffl, M Pasquale', MF Rotondo, CW Schwab-University of Pennsylvania Medical Center, Philadelphia, PA; 'Medical Center of Delaware, Newark, DE; ,Lehigh Valley Hospital, Allentown, PA, USA PURPOSE: Occult pneumothorax (OPTX) is defined as a pneumothorax seen on abdominal or chest CT scan which is not vizualized on admission CXR. The reported incidence of OPfX in blunt trauma population is between 6% and 28%. The purpose of this study is to establish management guidelines for OPfX in the bluntly-injured trauma patient. METHODS: Multi-center, prospective, non-randomized study of adult blunt trauma patients with OPfX. Intubated patients were excluded. Patients were admitted to an observation unit with telemetry and continuous pulse oximetry. A CXR was repeated 6lus after admission. Tube thoracostomy was performed at the discretion of the trauma service. Delayed tube thoracostomy was a tube thoracostomy performed after the initial 6 hr observation period. RESULTS: Twenty-eight patients were studied. The mechanism of injury was motor vehicle crash (57.1 %), falls (21.4%) and motorcycle crashes (10.7%). Four patients (14.3%) had a pneumothorax on 6HR-CXR: 2 required a delayed tube thoracostomy; 2 were successfully followed without thoracostomy. Twenty-four patients (85.7%) had no pneumothorax on 6HR-CXR: tube thoracostomy was performed in 2 patients undergoing positive pressure ventilation; 22 were successfully followed without thoracostomy. No patient developed symptoms during the observation period. In total, 24 of the 28 patients (85.7%) with OPfX were successfully observed without tube thoracostomy. CONCLUSIONS: In the absence of positive pressure ventilation, the majority of OPTXs remain radiographically occult and clinically benign. Under these conditions, routine thoracostomy is unnecessary. Thoracostomy is advised in the presence of increasing pneumothorax documented by 6HR-CXR, the development of symptoms, or in patients undergoing positive pressure ventilation. CLINICAL IMPLICATIONS: The standard of care for simple pneumothorax has been tube thoracostomy. However, the significant incidem:e of complications after tube thoracostomy in the trauma population suggests that avoidance of chest tube placement, if it can be done safely, may be desirable. This study demonstrates that OPfX, which does not progress clinically or radiographically, or requires positive pressure ventilation, may be safely observed.

Surgery: Thoracic MEDIASTINAL MASSES IN NEW MEXICO

Roy Thomas Ternes, RE Crowell, DW Mapel, LH Ketai, F Follis, JA Wemly. University of New Mexico, Albuquerque, NM, USA.

Purpose: Review the epidemiology, etiology and results of surgical management of mediastinal masses in New Mexico. Methods: A review of all surgically managed mediastinal masses at the University of New Mexico, the Albuquerque VA Medical Center, and the Albuquerque Lovelace Hospital between June 1992 and May 1996. Results: 18 patients were treated. 11 were male. Median age was 36 years (range 18 to82). 50% were Hispanic, 33% White, 11% Native American, and 6% Black. In New Mexico the population is 39% Hispanic, 50% White, 9% Native American , and 2% Black 56% of tumors were benign, 44% malignant. 75% of malignant tumors were in Hispanics, 0% in Whites, 13% in Native Americans, and 13% in Blacks. 30% of benign tumors were in Hispanics, 60% in Whites, 10% in Native Americans, and 0% in Blacks (p=0.03 Fishers Exact test; p=0.04 adjusting for age, Mantel-Haenszel, malignancy, Hispanics vs Whites). Symptoms occurred in 83%, and in 88% with malignancy. 72% had resection, 28% had biopsies. 72% of tumors were in the anterior mediastinum, 54% of these were malignant. 33% of tumors were in the posterior mediastinum, 83% of these were benign. 1 patient had benign cysts in both compartments. 54% had sternotomy, 31% had throracotomy, 15% had thoracoscopy. Complications occurred in 22%. There were no operative deaths. Conclusions: Many tumors in the anterior mediastinum are malignant. Malignancy is more common in Hispanics compared to Whites. Surgery has low morbidity and mortality rates. Clinical Implications: 44% of mediastinal masses are malignant. Malignancy is more common in Hispanics. Surgery is safe.

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CORRELATION BE1WEEN 3-D SPIRAL COMPUI'ERIZED TOMOGRAPHY OF THE AIRWAY AND VIDEO ASSISTED RIGID BRONCHOSCOPY IN PATIENTS WITH OBSTRUCTIVE TRACHEOBRONCHIAL DISEASES Anthony P.C. Yim, BM, FCCP*; Jacqueline Kew, MB+; Victor Abdullah, MB*- Dept. of Surgery* and Diagnostic Radiology & Organ Imaging+, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong Purpose: The advent of spiral computerized tomography allows a scanning of the thorax and reconstruction of the tracheobronchial tree into 3-D images. The fast scan time of under 30 seconds gives it an advantage over the other imaging modalities (like tomograms or MRI) which take much longer and hence present difficulty for patients in hofding their breath with critical airway stenosis. We investigated the role this imaging modality in the management of obstructive tracheobronchial disease in our hospital using a GE Hi Speed Advantage CT scanner. Methods: From September 1995 to February 1996, 9 patients (5 males, 4 females with age ranged from 18 to 76 years) presented with airway obstruction were imaged with spiral CT and the information obtained was then correlated with video-assisted rigid or flexible bronchoscopy. The proximal and distal levels of the stenosis as well as the degree of stricture were measured from the CT films and the recorded video on rigid bronchoscopy. Results: There was excellent correlation (9/9 or 100%) between spiral CT and bronchoscopic findings on the proximal level of obstruction. However, correlations on the distal level as well as the degree of stenosis were not as good (719 or 77.8%) especially for the critical stenosis. Conclusion: Spiral CT allows rapid visualization of the airway with no dis<:omfort to the patients. The proximal level of stenosis can be accurately imaged with this modality. However, it fails to differentiate mucus plugs from true stenosis due to disease process or external compression. Moreover, the technique relies on visualizing the air column in the tracheobronchial tree and if there is near complete obstruction (by tumor or mucus), the true extent (degree and length) of the stenosis cannot be reliably determined. In those cases where spiral CT shows patient airway distal to the stenosis, it is helpful to the planning of further management. However, failure to show a patent distal airway does not preclude its existence. Clinical Implications: Spiral Cf allows rapid visualization of the airway and could generate useful information in helping further management. However, limitations of this technique has to be clearly understood.

Abstracts of Originallnvestigations, CHEST 1996

Tuesday, October 29 5:00-7:30

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Surgery: Thoracic, continued TRACHEAL STENTING IN THE MANAGEMENT OF MALIGNANT TRACHEAL STENOSIS SECONDARY TO ESOPHAGEAL CARCINOMA Anthony P.C. Yim, BM, BCh, FCCP, Victor J Abdullah, MB, BS, Johnathan K. Ho, MD . Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong Purpose: Esophageal carcinoma is a common disease among Chinese. Tracheal stenosis could result from direct tracheal invasion or e>.temal compression. vVe report our experience in the management of this condition with tracheal stents in Hong Kong. Methods: From Fe bruary 94 to February 95, 13 patients (11 males and 2 females with ages ranging from 46 to 81 years) with esophageal carcinoma complicated by extrinsic tracheal compassion or invasion leading to symptomatic narrowing of the tracheobronchial tree were studied. Flexible bronchoscopy and high speed helical CT scan were used in the initial evaluation. Selection criteria for tracheal stenting include (1) localized symptomatic narrowing in the trachea or main branch; (2) patent distal airway; (3) good pulmonary reserve. Under total intravenous anaesthesia, a ventilating rigid bronchoscope with a Hopkins telescope (Efer- Dumon Bronchoscope, LaCiotat, France) attached to a video camera wa~ introduced perorally into the airway. The airway was dilated \vith the rigid scope and a silicone stent with studs (Duman stent, Marse ille, France) was placed using standard placement technique. In 1 case, "coring out" of the tumor was necessary prior to stent placement. Direct tamponade and Homium-YAG laser were used to achieve hemostasis when necessary. Results: There was no surge1y related mortality. Symptomatic re lie f was achieved in all cases and recorded on a visual analogue scale. Improvement in exercise tolerance and daily activity was achieved in nearly all cases (10 out of 13 patients). Patients were followed up prospectively until death. Recurrence of tumor proximal or distal to the placed stent was noted in 3 ca,es. The mean survival after surgery was 4 months. Those patients with bronchoscopic evidence of mucosal infiltration at the time of stent place ment had substantially shorter survival compared to the group that did not have mucosal involvement (4.3 versus 1 month p<0.05). Conclusion: Tracheal stenting is a safe and effective approach in the management of malignant tracheal stenosis secondary to esophageal carcinoma, even though those patients with mucosal infiltration have a v el)' short survival.

MINIMALLY INVASIVE BULLAE ABLATION: RESULT USING HOMEMADE ENDOLOOP Hui-Ping Liu , MD; PJ Lin, MD; JJ C hu, MD; JP Chang, MD; MJ Hsieh, MD; CH Chang, MD. Div. of Thoracic & Cardiovascular Surgery, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipe i, Taiwan, ROC Purpose: Endoscopic stapling device has been a preferred method for resection of pare nchymal blebs or bullae, the stapling device however is not inexpensive. Due to cost containme nt, we have used the self-made endoloop as an alternative method which assisted us in performing bullae ablation in a cost e ffective manner. This report assess the efficacy of the thoracoscopic self-made endoloop ligation of parenchymal blebs and bullae in patients with spontaneous pneumothorax. Method: In a 4-year period (1992-1996), we reviewed a total of 376 thoracoscopic endoloop ligations of pulmonary ble bs and bullae for de finitive treatment of spontaneous pneumothorax in 300 patients. Patients selected for surgery includes recurrence ( 156), bilate rality of the disease (23), hemopneumothorax (7), radiologically demonstrated large bulla (9), pe rsistent air leak (76) and nonexp ansion of the lung (29). All clinical data were collected from cha1t review. Only patients \vith thora<.'Oscopic confirmation of the bullae were included in this evaluation. Thoracoscopic ligation using No. 1 PDS (polydiaxanone suture) was carried out under general anesthesia and single lung ventilation. Result: There was no operative death. Early postoperative complications include 1 patient who required re-exploration for a dislodged en do loop and 13 \vith postop erative minor wound infections. The average postoperative hospitalization wa~ 4.5 days. Two hundred fifty-eight patients (86% of all patients) were followed-up for a median of28 (1-46) months after surgery. There have been no recurrences to date . Conclusions: By comparison , our results showed that thoracoscopic endoloop ligation is as effective and safe as is stapler resection with a lowe r cost, fewer complications and a lower recurrent rate in managing the blebs and parenchyma bulla. Clinical Implication: On the basis of our results, we advocate the use of the self-made endoloop for ligation of parenchymal blebs and bulla in patients with spontaneous pneumothorax to achieve a truly cost e ffective and minimally invasive thoracoscopic procedure.

EFFECT OF ONE LUNG VENTILATION ON ATRIAL NATURETIC PEPTIDE RELEASE Rudy P Lackner, MD, JH Sisson, MD, SKRoy, Ph.D, GE Hill, MD University of Nebraska Medical Center, Omaha, NE 68198-4455 Purpose: The response in arte rial oxygen tensions to one lung ventilation (OLV) during thoracotomy is not predictable in humans. The major response of the human lung to OLV is hypoxic pulmonary vasoconstriction (HPV), which increases pulmonary vascular resistance and subsequent right ventricular (RV) afterload. RV afterload may cause right heart dilation, which is a potent stimulus for atrial naturetic peptide (ANP) release. Since ANP is known to be a potent pulmonary vasodilator, right heart ANP release may inhibit HPV, increasing intrapulmonary shunt (QS/QT) fraction and result in systemic reduction in arterial oxygen t ension. We investigated the relationship of ANP re lea' e with Qs/Qt prior to and after the institution of OLV in humans. Methods: After IRB approval and patient consent, 10 patients scheduled for thoracotomy requiring 0 LV had catheters placed in a radial artery and the right atrium (RA). Blood for ANP determination (RIA technique, Peninsula Labs, Belmont, CA) was drawn simultaneously from the RA catheters and by direct puncture from the left atrium LA at 1) during both lung ventilation (BLV), 2) after 20 min of OLV. Blood for blood gas tensions were drawn simultaneously (simultaneously with ANP) from the arterial line and RA. Qs/Qt was calculated by standard equation. F102 was 1.0, end tidal isoflurane <.'Oncentrations were always under 1.0%, and in all patients tidal volume and respiratory rate were decreased and increased , re spectively, by 20% with onset of OLV. The Spearman correlation coefficient (C .C.) for small data sets was used to determine significance. Results: Qs/Qt: BLV 20.6::!:8% OLV 36.4::!:11% ANP concentrations (pg·ml- 1) BLV RA 134±31 LA 155.4::!:41

OLV 163::!:96.8 185.1::!:72.6

C. C. r=55 r=49

Conclusions: These results demonstrate ANP release is not consistently found during OLV. Clinical Implications: RV dilation and ANP release do not impact on arterial oxygenation during OLV.

VIDEOASSISTED THORACIC SURGERY AND VIDEOTHORACOSCOPY: RESULTS OF A SERIES OF 200 CONSECUTIVE CASES. E Canalis, MD , FCCP; X Baldo, MD; J Beida, MD; L Salvador, MD; S Pascual, MD ; JM Jardf, MD; M Catalan, MD; MA Callejas, MD; JM Gimferrer, MD and J Sanchez-LLoret, MD, FCCP. Thoracic Surgery Department. Hospital Clinic, Universitat de Barcelona. Barcelona, Spain. The development of new surgical endoscopy techniques has recently reached thoracic surgery. Purpose: To evaluate the advantages of videothoracoscopy (VT) and videoassisted Thoracic Surgery (VATS), while keeping the same surgical indications. Patients and Methods: From november 1991 to december 1995 we pe rformed 200 video-assisted operations (43 lung nodules, 8 mediastinal tumors, 9 pleuroparietal tumors, 34 biopsies in diffuse lung diseases, 106 recurrent pneumothoraces). One hundred and forty eight were men, 52 women, and age average 43.1 years. With the patient in lateral thora<.'Otomy position, under general anesthesia and selective intubation, we usually use a triple trocar positioning (two 12 mm and one 10 mm , vmiable situation). This allows changing optical and other surgical instruments position, according to the ongoing of the operation. In the case of resection of lung nodules bigger than 3 em of diameter we use to make a utility minithoracotomy, which makes easier palpation of the el sion, resection and extraction of it out of the pleural cavity. The intervention is followed through a TV monitor. Results: Mean postoperative stay was 5.4 days. Chest drainage was outdrawed between the second and fourth postop days. Conversion to thoracotomy was needed in 24 cases (5 for hemostasis, 8 insufficient exposure or extensive pleural adhesion and ll for oncological criteria). We had 5 cases of pneumothorax recurrence in this series, probably because of ineffective pleurodesis. Complications were rare and generally mild, except the relapse of a tumor in the traject of one of the trocars in spite of its rubber protection for extraction, and respiratory failure in a patient who underwent lung biopsy for diffuse lung disease, who died at the lOth postoperative day. Conclusion: VT and VATS are efficient and safe technical options for diagnosis and/or treatment of many thoracic processes. Clinical Implications: Since VT and VATS show to have evident advantages over thoracotomy, it is estimated that these procedures will make up 20-30% of all thoracic interventions in our Department.

CHEST I 110 I 4 I OCTOBER, 1996 SUPPLEMENT

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Surgery: Thoracic, continued PULMONARY BIOPSY BY VIDEO ASSISTED THORACIC SURGERY (VATS): EXPERIENCE OF 76 CASES Paulo M Pego-Fernandes, MD; FB Jatene, MD; AP Simoes; LTB Filomeno, MD; C Cmvalho, MD; A Cukier, MD. Thoracic and Cardiovascular Surg. Dept. Hospital Clinicas!InCor University of Sao Paulo Brazil

BRONCHIECTASIS SURGICAL TREATMENT AND LONG TERM FOLLOW UP Lufs Miguel Sancho Melero, MD; MS Paschoalini, MD; FC Vicentini; MH Fonseca; FB Jatene, MD. -Thoracic and Cardiovascular Surg. Dept. Hospital Clinicas!InCor University of Sao Paulo Brazil.

Purpose: Among VATS several appucations there is the possibility of perfonning pulmonary biopsy in diffuse lung diseases previously performed by open thoracotomy. Methods: Between June/92 and February/95, 76 patients were submitted to a pulmonary biopsy by VATS. Age ranges from 19 to 72 years (mean 47), 57% male. The most common indications for biopsy were interstitial fibrosis and interstitial pneumopathy. Two main techniques were used. In one a stapler was used to simultaneously resect the biopsy and suture the parenchyma. This technique was utilized in 72% of the patients. The second technique employed was an endo-loop suture (Vicryl1-Ethicon) to provide the parenchyma suture and was utilized in 24% of the patients (fig. 2). In 2% of the cases, due to good lung elasticity external traction biopsy and parenchyma suture with 5.0 polypropylene nne were done. The best place for biopsy was determined by the scope. In one patient (2.2%) it was not possible to perform VATS due to adhesions between the lung and the thoracic wall, and as a result, open conventional biopsy was performed. Results: A histological diagnosis was obtained in all patients. The results showed mainly interstitial fibrosis and pneumonia. There were no complications related to the methods used. Two patients (4.4%) died in the postoperative period due to previously existing pathology. Conclusions: ·we conclude that VATS has proven to be a good, and minimally invasive method for lung biopsy, permitting the choice of the best place for biopsy with effective histological diagnosis. In patients with less compromised parenchyma, we believe that endo-loop is adequate and has the advantage of a lower cost. Clinical Implications: VATS seems to be an ideal method for performing pulmonary biopsy.

Purpose: The aim of this study is to evaluate the importance of the surgical approach for the treatment of bronchiectasis through a retrospective study in a group of patients operated on at our institution. Methods: 41 patients diagnosed with bronchiectasis were analyzed, being submitted to pulmonary resections from 1981 to 1995. Topographic diagnosis of the lesions was made by bronchography and CT Scan of the thorax. Twenty four patients showed lesions at the left lung (58.5%), 30 patients at the right lung (31.7%) and four patients (9.8%) showed bilateral lesions. Segmentectomy (10%), lobectomy (73%) and pneumectomy (17%) were performed. Results: Thirteen cases (31.7%) evolved \vith no fatal complications as air leak, pleural empyema, bleeding and lung abscess, \vith evolution not longer than 30 days until resolution. The mean time of drainage was 10 days. One patient died (2.4%) of massive hemorrhage at the imediate post operative period. There were no deaths in the long term follow-up. Eighty-eight percent of the patients evolved assymptomatic and 5% with return of the symptoms, needing a new surgical intervention. Conclusions: Pulmonary resections have proven to be effective in the treatment of bronchiectasis, with low rates of mortality and morbidity. Clinical Implications: With the evolution of antibiotic therapy in the last 20 years, the incidence of bronchiectasis has decreased greatly, however, the treatment of choice for localized and symptomatic lesions continues to be pulmonary resections.

SURGICAL TREATMENT OF LUNG ABSCESS Luis Miguel Sancho Melero, MD; MS Paschoalini, MD; C. Higutchi; FB Jatene, MD - Thoracic and Cardiovascular Surg. Dept. Hospital Clfnicas/ InCor University of Sao Paulo-Brazil.

THE "OPEN TUBE THORACOSCOPY" IN MODERN THORACIC SURGERY Jose Ribas Milanez Campos, MD; LTB Filomeno, MD; A Fernandes, MD; EC Werebe, MD; LO Andrade, MD; ML Tedde, MD; FB Jatene, MD. Thoracic and Cardiovascular Surg. Dept., University of Sao Paulo, Medical School - Brazil

Purpose: The authors analysed a group of patients \vith lung abscesses that received surgical treatment, as well as the characteristics of their evolution. Methods: Twelve patients with lung abscesses which underwent surgical therapy from 1984 to 1995 were analysed. The group was composed of9 male and 3 female. The age varied from 25 to 66 years (mean-44.2 years). The etiologies were: post-pneumonic (75%), tuberculosis, foreign-body, empyema (25%). Two types of surgical procedures were performed: pulmonary resection-7 patients and external chest tube drainage-S patients. The indication of surgery was based on the failure of clinical treatment, massive hemoptysis, pleural empyema and residual cavity \vider than 2 em after 6 weeks of clinical treatment. The patients with poor clinical conditions were selected to external tube drainage, the less invasive procedure . Results: Most patients had a satisfactory postoperative evolution (66.7%). Three patients had comphcations (25%) as empyema and air leak for more than three weeks and one patient died (8.3%) of sepsis. Regarding the surgical thecnics, the pulmonary resection (lobectomy and segmentectomy) showed no morbidity and modality. The usage of external chest tube drainage of the abscess had a morbidity of 40% and modality of 20%. Conclusions: The complicated lung abscess is still a surgical pathology and the best approach seems to be the resection of the pulmonary segment affected. The drainage has specific indication, mainly in patients with deteriorating condition, but this procedure has high mortality and morbidity rates. Clinical Implications: In spite of the variety of antibiotics that may be used in the cunical treatment of lung abscess, in cases of failure of this treatment, the surgical treatment has proved to be efficient with low and acceptable levels of morbidity and mortality.

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Purpose: We started to work with "Open Tube Thoracoscopy" (OTT) in the diagnosis and management of thoracic diseases in August of 1983, and until February of 1996 we have treated 565 patients. We would like to present our results and conclusions. Methods: More than three hundred patients underwent diagnostic thoracoscopy: biopsy of pleura (242), pulmonary infiltrates or masses (73), mediastinal tumors (23), pericardia! sac (08) and staging of lung cancer (09). About two hundred undenvent therapeutic thoracoscopy that.was done for pneumothorax (38), loculated parapneumonic pleural effusion or empyema (96), pleurodesis with talc for malignant effusions (196), pleurodesis for benign diseases (60), clotted hemothorax (39), intrapleural foreign bodies (03) and thoracic trauma (ll) . The majority of those surgical procedures (95.7%) was done under general anesthesia, with a single (58.76%) or double-lumen ventilation (41.24%), and closed pleural drainage (28 or 36 fr.) was used in all patients. Results: With respect to all therapeutic and diagnostic procedures used, the overall success rate is about 89%. Srecific complications related to OTT were rare, and occur in 16 (2.83%) o all patients. There were 9 (1.59%) deaths before 30 days, but none off than due to the procedure. Conclusions: We agree that nowadays minimally invasive surgical techniques have a significant impact on the indications for operative surgery in the thorax. In some of than, OTT is simple, inexpensive, easy to work with and a vety effective method. Clinical Implications: In fact, it appears that have advantages in the management of: pleural biopsy, pleurodesis with talc for malignant effusion, clotted hemothorax and loculated parapneumonic pleural effusion or empyema.

Abstracts of Original Investigations, CHEST 1996

Tuesday, October 29 5:00-7:30

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Surgery: Thoracic, continued MULTI-USE INVESTIGATION OF FIBRIN SEALANT IN EXPERIMENTAL CHEST SURGERY VS Chekanov, CV Tchekanov, W Nikolyachik, MA Rieder, DH Schmidt. Milwaukee Heart Institute, Milwaukee, Wisconsin, USA. Purpose: Investigation focused on 3 different uses of fibrin sealant in experimental chest surgery (i.e. , cardiomyoplasty) to prevent: 1) formation of seroma; 2) ) open pneumothorax; and 3) ischemia-reperfusion injury. In cardiomyoplasty, a large (25-30 em) incision creates an extensive site for potential seroma formation; the thoracotomy needed to allow the latissimus dorsi muscle (LDM) to be wrapped around the heart leaves this area susceptible to development of open pneumothorax; and mobilizing the LD M causes ischemia-reperfusion damage. Methods: In the 18 adult sheep in the control group (no fibrin glue), the wound after muscle mobilization was 450-500 sq. em; seroma formation occurred 2-4 days postoperatively, accumulating to 400-950 mi. In an experimental group of 4 sheep, fibrin sealant was 1) inserted as a sealant between the skin and LDM tissue immediately after muscle mobilization and 2) applied prophylactically to the sutures closing the chest. In addition, 3) in a second experimental group of 4 sheep, a combination of autologous fibrin sealant with and without aprotinin was studied for prevention of ischemiareperfusion injury to the LDM. Results: 1) In the first experimental group, no seroma development was noted in 3 sheep and accumulation was only 150 ml in the fourth , and 2)) there was no postoperative evidence of pneumothorax in any of the 4 sheep. 3) In all4 sheep in the second experimental group, recovery after initial ischemia was accelerated and the process of angio~enesis was enhanced. Conclusion: As hypothesized, use of fibrin glue prevented or limited formation of seroma, prevented open pneumothorax, and accelerated both recovery from ischemia and the process of angiogenesis. Clinical Implications: Autologous fibrin seafant has several potential uses for large operations lllat involve the thoracic cavity, including: adhering tissue \vithout infection, limiting ischemic and other surgery-related injUiy (such as pne umothorax), and promoting the healing process after surgery.

EXPANDED USE OF A MULTIFACTORIAL CARDIOPULMONARY RISK INDEX TO ASSESS RISK OF THORACIC SURGERY Scott K. Epstein FCCP, JC Lucke, JJ Zulu eta, BOT Daly FCCP. Pulmonary/ Critical Care Div. and Thoracic Surgery. New England Med. Ctr., Tufts Univ. Sch. Med. , Boston, MA, USA Purpose: A multifactorial cardiopulmonary (CP)risk index (CPRI) can predictCPcomplications (CP-POC) after lungcancerresection in VA(97%o) patients (Chest 1993:104:694). To further test the CPRI we studied 104 patients (63o, 41 '? ), 65± 1 yrs, who had thoracic surgery (85 lung cancer resections, 19 esophageal!mediastinal procedures) at a university medical center. Method: The CPRI score (range 1-10) was measured by adding the Goldman class (range, 1-4) to a pulmonary risk index (range, 1-6: one point each for obesity, smoking within 8 wks, productive cough, wheezing, FEY 1/ FVC<0.7, PaC0 2 >45) . Study endpoints were CP-POC (MI, CHF, treated arrhythmia,respiratory failure, PE, pneumonia) and surgical-POC (air leak>7d, empyema, wound infection, anastomotic leak). Results: CP-POC occurred in 33% and surgical-POC in 19%. Men had more CP-POC (38% v.24%, p~.12 ) and surgical-POC (25% v. 10%, p<.05). Higher CPRI scores were highly predictive of CP-POC (CPRl<4, 23% v. ~4 . 62%, p<.001, RR 5.3, 95% CI2-14), especially for men (<4,26% v.:5:4,79%, p<.001, RR 10.2, CI 2-42). While no women with CPRl<3 had a CP-POC, only a higher threshold score significantly separated those with CP-POC (<5,17% v.~5 . 67% , p<.01, RR 9.7, CI 1.4-65). For non-lung cancer surgery, CPRI:s;S suggested an increased risk (<5,29% v. s;S,IOO%, p~.12) The CPRI was not predictive of surgical-POC ( <4, 18% v.;S;4,23%, p~NS ) .

Conclusions: The CPRI is predictive of CP-POC but no surgical-POC in noncardiac thoracic surgery. Though predictive for a broader range of patients than previously reported, accuracy is highest for men undergoing lung cancer surgery. Clinical Implications: Use of the CPRI can be extended to women undergoing lung cancer resection to assist in risk assessment. Larger studies are needed to define the CPRis role in other types of noncardiac thoracic surgery.

MINIMALLY INVASIVE THORACIC SURGERY (MITS) TO PERFORM LOBECTOMY FOR CLINICAL STAGE I CARCINOMA IS BOTH SAFE AND COST EFFECTIVE Robert L Quigley MD PhD; A Farid MD; MW Chisdak MD; FL Reitknecht MD-Cuthrie Clinic, Sayre, PA, USA

HEPATIC AND PULMONARY BIOPSY BY MINI-THORACOTOMY AND TRANSDIAPHRAGMATIC ACCESS Angelo Fernandez, MD; RH Bammann, MD; ACP Castro, MD; DE Uip, MD; FB Jatene, MO.-Thoracic and Cardiovascular Surg Dept. University of Sao Paulo. Medical School, Brazil.

Purpose: The surgical management of stage I lung carcinoma originated with the posterolateral thoracotomy from which the muscle sparing thoracotomy (MST) evolved and more recently video assisted thoracoscopic surgery (VATS) with or without an "access" incision. None are ideal. In this study we compare the morbidity and cost of our minimally invasive procedure (MITS ) to the conventional MST in the management of stage I lung carcinoma. Methods: Ten consecutive patients (group A) in the lateral decubitus position underwent a modified MST (MITS ) through a 7 em incision over the fourth intercostal space. Using a retractor the space was widened 4 em without rib removal or fracture. A standard lobectomy was performed using both staples and sutures and the chest was not closed until all air leaks were obliterated. All patients were extubated in the OR. Perioperative analgesia was managed with a single 5 mg morphine bolus via an epidural catheter. All single chest tubes were removed the following a.m. The length of stay (LOS) and hospital charges were determined in group A and compared to 10 consecutive patients who underwent lobectomy via a conventional MST for similar pathology (group B). Results: The mean LOS in group A was 1.8 days with a mean hospital charge of$4970.45, group B was 5.4 days and $9590.28. One patient in group A was readmitted with contralateral pneumonia. Conclusion: MITS avoids significant rib spread and pain. Obliteration of all air leaks intraoperatively allows early chest tube removal and mobilization. Clinical Implications: MITS is associated with minimal morbidity and early hospital discharge.

Purpose: Immunocompromised patients frequently have more than one afflicted organ or system requiring quick and precise diagnostic investigation. Methods: Twenty patients underwent open lung and hepatic biopsy. In this way it has been proposed that the surgeon, by means of a microthoracotomy utilized for the pulmonary biopsy, have access to the diaphragm, performing a small phrenotomy and then a liver needle biopsy under direct visualization. The proposed technique permits easy handling of the needle as well as hemostasis of hepatic lesion at the puncture site. Chest drains are not necessary. Results: This method has been used since 1994 and until the present time in 20 AIDS patients, presenting clinical manifestations of pneumopathy and hepatopathy of unknown etiology. Different etiologic agents for the affliction of the lungs and liver were found in 50% of the patients. We had no complications with this procedure. Conclusions: We conclude that the presented technique is useful, safe and simplifies surgical procedure. Clinical Implications: It deals with a useful and simple technique of simultaneous open lung and hepatic biopsy.

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continued

MEDIASTINOSCOPY IN SUPERIOR VENA CAVA SYNDROME Angelo Fernandez, MD; LTB Filomeno, MD; JRC Milanez, MD; RH Bammann, MD; FB Jatene, MD. - Thoracic and Cardiovascular Surg. Dept. University of Sao Paulo, Medical School-Brazil. Purpose: Cervical mediastinoscopy is used to evaluate mediastinal masses and staging lung carcinoma. Despite its widespread use, contraindications concerning vascular compression syndromes have not been well established. There is a fear of hemorrhagic complications but morbidity is not as expected. Methods: Since 1986, mediastinoscopy was performed on 24 patients presenting caracteristic signs of SVC obstruction confirmed by CT in all cases. Results: The histologic findings were lymphomas (7, 30%), germ-cell tumors (2, 8%), squamous cell lung carcinoma (3, 12%), large cell (2, 8%), oat-cell (6, 25%), fibrosis (4, 17%) . One hemorrhagic complication occurred due to a lesion of the vena cava (hemostasys was reached by local compression and biological glue). All patients with diagnosis of neoplasia underwent radiation or chemotherapy within 24 hours after operation. Two patients with fibrosis mediastinitis underwent SVC bypass. Conclusions: Mediastinoscopy is a safe and effective diagnostic procedure in SVC syndrome. Clinical Implications: Venous congestion seems to apply to supe1ficial tissues and allows mediastinoscopy to be a useful and reliable diagnostic procedure in vascular compression syndromes, when less invasive diagnostic tools are not effective.

EFFECTS OF THORACOTOMY AND THORACOSCOPY ON RESPIRATORY MUSCLES Nikoletta K Rovina, MD; DE Bouros, MD; G Chalkiadakis, MD; J Drositis, MD; M Samiou, MD; N Tzanakis, MD; NM Siafakas, MDUniversity Hospital, Heraklion, CRETE, Greece Purpose: The aim of this study was to investigate the effect of thoracoscopy on respiratory muscle strength and to compare it to open thoracotomy. Methods: In 22 patients who underwent thoracotomy (mean age 58:!:14 years) and in 12 who unden.vent thoracoscopy (mean age 60::'::17 years), respiratory muscle strength was assessed by measuring mouth pressure during maximum static inspiratory (Pimax) and expiratory (PEma.x) efforts. Plmax, PEmax and blood gases were measured 24 hours preoperatively ( - 24h), as well as 48 (+48h ) and 72 ( +72h) hours postoperatively. FEV1 and FVC were measured at -24h and+ 72h and FEV1/FVC was calculated. Results: Mean values (::t::SD) of static pressures as% of predicted values were: Pimax in the thoracoscopy group was found to be: 93::'::28 ( -24h), 56:::'::22.5 (+48h), 72:::'::25 (+ 72h); In the thoracotomy group was found to be: 90::'::28 ( -24h), 60:::'::28 ( +48h), 53::'::25. Pemax in the thoracoscopy was found to be: 92::'::32 (-24h), 59::'::36 ( +72h) In the thoracotomy was found to be: 97:::'::35( -24h), 54:::'::30 ( +72h). No statistically significant difference was found between Plmax and PEmax in the two groups, except +72h. Conclusions: Our results suggest that thoracotomy and thoracoscopy affect similarly the respiratory muscles.

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RIGHT VENTRICULAR FUNCTION AS A RISK FACTOR OF ARRHYfHMIAS AFTER PULMONARY RESECTION Morihito Okada, MD; Keiichiro Kujime, MD; Shinsuke Satake, MD; Hajime Yamamoto, MD- National Hyogo Central Hospital, Sanda City, Hyogo, JAPAN Purpose: Cardiac aJThythmias are widely known complications after noncardiac thoracic operations. Vmious predictors of these aJThythmias have been sought, yet very few significant ones have been identified. The purpose of this study was to assess the possible association with right ventricular function and the occurrence of postoperative arrhythmias in patients undergoing major pulmonary resections. Methods: Right ventricular function was measured using a thermodilution technique in 36 patients before lobectomy or pneumonectomy for carcinoma of the lung. Serial electrocardiograms were recorded during the first 3 postoperative days and whenever cardiac symptoms occurred. The patients were divided into two groups, those with episodes of postoperative atrial arrhythmias a.nd those 'vithout episodes. Results: Atrial arrhythmias, all of which were atrial fibrillation (A f), ocCUlTed in 7 (19%) of the 36 patients after operation and no episodes of venhicular arrhythmia were documented. Right ventricular end-diastolic volume index (Af(+); 138:::'::23mUm2 versus Af(-); 108::'::20mUm2) and right ventricular end-systolic volume index (Af( +); 88:::'::21mUm2 versus Af( - ); 61:::':: 16mUm2) were strongly associated with postoperative Af (p<0.01 ). A weaker association (p <0. 05) was found between postoperative Af a11d age (Af( + ); 71 ::'::5 versus Af(- ); 61 :::'::9) and 1ight ventricular ejection fraction (Af(+); 37:!:6% versus Af(-); 44 ::'::6%). Conclusions: \.Ve conclude that evaluation of right ventricular pe1formance is useful in identifYing patients at increased 1isk for cardiac dysrhythmias foiiO\ving thoracotomy for lung cancer. This study suggests that enlarge ment of right ventJicle might be the risk factor, 1ight ventricle might be the risk factor.

IS SURGERY FOR NON-SMALL CELL LUNG CANCER JUSTIFIED IN PATIENTS OVER 70 YEARS OF AGE? PaolaCiJiaco, A. Puglisi, A. Carretta, B. Canneto, P. Zannini, A. Grossi-HS Raffaele, Milano, Italy Purpose: The aim of this study was to evaluate the benefit of surgery in patients >70 years of age 'vith non-small cell lung cancer (NSCLC ) in terms of postoperative complications, rehabilitation, and SUivival. Methods: Between January 1992 and January 1996, 75 patients, 64 men and 11 women, mean age 74.6 years (range 70-83), underwent surgical rese<.:tion for primary NSCLC. At the time of admission 24 patients presented associated cardiovascular and/or respiratory problems (32%). Preoperative assessment included also echocardiography and/or miocardia! sca11 in patients with concomitant cardiological problems. The six-minute walking test (6-M\VT) was used in 21 patients at high risk for pulmonary resection. All patients had pulmonmy rehabilitation. Pulmonary embolism was prevented with heparin and the use of a leg sequential pneumatic compression device. Postthoracotomy pain was managed using continuous epidural analgesia or patient controlled analgesia. Results: Preoperative FEV1 %, FVC% and Pa02 were respectively 80% (range 48-97), 84% (range 58-100) and 87 mmHg (range 68-97) and influenced postoperative complications 70 years of age with NSCLC, should be give n the opportunity of surgery provided that no major postoperative cardiorespiratory complication are foreseen. Clinical Implications: Careful preoperative evaluation, pulmonary rehabilitation and management of postoperative pain can reduce postoperative risk of cardiorespiratory failure.

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Surgery: Thoracic, continued PULMONARY RESPIRATORY QUOTIENT (PRQ) PREDICTS PULMONARY COMPLICATIONS AFTER THORACIC SURGERY Rafael Barrera MD, Jose AMelendez MD Memorial Sloan-Kettering Cancer Center, Cornell University Medical College, New York, NY PURPOSE: To develop a new quantitative predictor of post-thoracotomy pulmonary complications using routine lung function tests. METHODS: Data of consecutive patients who underwent lung resection only for malignancy and had preoperative pulmonary function tests; FEV1 and single breath DCO, resting arterial blood gas analysis; P(A-a)Oz and quantitative lung perfusion scans performed in our laboratory were included in this study. Predicted postoperative values (ppo) FEV1%, ppo DCO% and P(A-ahO were calculated for all patients. Pulmonary complication was defined as pneumonia, atelectasis or respiratory insufficiency requiring therapy. Statistical analysis was performed using Stepwise Logistic Regression (p:5.0l) and Relative Risk (odds ratio). RESULTS: Sixty patients were studied, pneumonectomies (n=30) and lobectomies (n=30). The mean age was 65:!::11 years. Nine patients had pulmonary complications including 2 deaths. The following formula was designed: PRQ=(ppo FEV1%)x(ppo DC0%) 21P(A-a)02 A PRQ < 3200 was associated with a sensitivity of 100% and specificity of 95% for pulmonary complications. PRQ was associated with a positive predictive value of 75% and a negative predictive value of 100% for pulmonary complications. A PRQ < 3200 was associated with an estimated relative risk of pulmonary complications of 54:1 (95% Cl:3-972). CONCLUSIONS: The construct PRQ has an excellent association with postoperative pulmonary complications. This novel index not only incorporates predicted postoperative estimates of FEV1% and DCO% but adds P(A-a)Oz and weights the relative contributions of each of the three variables. Pulmonary Respiratory Quotient may be the most significant predictor of pulmonary morbidity in patients undergoing lung resection. CLINICAL IMPLICATIONS: This new index warrants serious prospective evaluation as a predictor of pulmonary morbidity and mortality.

PERIOPERATIVE CHANGES IN MAGNESIUM AFTER THORACIC SURGERY David Amar, MD, FCCP; C Toth, MD; M Fleisher, PhD; RJ Downey, MD-Memorial Sloan-Kettering Cancer Center, New York, NY Purpose: Supraventricular dysrhythmias (SVD) after non-cardiac thoracic surgery occur in 10%-25% of patients and have been attributed to acute decrements in serum magnesium (Mg• 2). Actual data on alterations in serum Mg• 2 concentrations after lung resection are sparse. Methods: We studied 16 patients scheduled for major,pulmonary resection. Excluded were patients receiving 13-blockers or Ca• -antagonists. Heparinized arterial blood samples for serum Mg• 2 and Ca•2 (for comparison) were obtained before surgery (PRE), on arrival to the post-anesthesia care unit (PACU) and on the morning of postoperative day (POD) l. Data (mean:!:SD) were analyzed using a Student t-test and P <0.05 was considered significant. Results: Of the 16 patients (8MI8F) aged 65:!:: 15 yr., 15 had undergone a lobectomy and one a pneumonectomy. When compared tobaseline, there were no significant differences in serum magnesium or calcium postoperatively (Table). PRE

PACU

POD1

Mg• 2 (mmoVL)

0.8:!::0.1

0.7:!::0.1

0.8:!::0.1

ca• 2 (mmoVL)

2.2:!::0.1

2.1:!::0.1

2.1:!::0.1

Conclusions: Serum concentrations of Mg• 2 and Ca• 2 did not change significantly within 24h of major thoracic surgery. These prelimina2' data do not support an important contribution of decreases in serum Mg• to SVD generation. However, because SVD often occur 24-48 hours after thoracic surgery, future studies may explore whether Mg• 2 alterations later in the postoperative period are associated with an increased incidence of SVD.

SUPRAVENTRICULAR TACHYCARDIA AFTER EXTRAPLEURAL PNEUMONECTOMY FOR MALIGNANT PLEURAL MESOTHELIOMA David Amar, MD, FCCP, N Roistacher, M.D. D Leung, PhD, V Rusch, MD, FCCP, Memorial Sloan-Kettering Cancer Center, New York, NY Purpose: The incidence of supraventricular tachycardia (SVf) and potential etiologic factors for this complication after extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM ) have not been well studied. Methods: We prospectively studied 25 patients undergoing EPP without prior history of dysrhythmias. Transthoracic-Doppler echocardiograms were performed pre-and post-operatively (days 2-4) in 21125 patients, and preoperatively (only) in 2/25 patients. Extent of resection (:tpericardiectomy), pericarditis documented by 12-lead ECG or Holter monitoring and pathologic stage were recorded in a prospective database. Student t-test and Fisher's exact test were used. Results: SVf occurred in 10/25 (40%) patients [atrial fibrillation (n=9), atrial flutter (n=1)]. One patient had a hypoxic event leading to reversible ventricular tachycardia. RISK FACTOR Age (Yr) Male Right EPP Stage: I or III Stage: III Pericardiectomy Pericarditis-ECG Right Heart Enlargement

(n=lO)

svr

No svr (n=15)

64:tll 9(90%) 7 (70%) 3 (30%) 7 (70%) 4 (40%) 5 (50%)

54:t9 12 (80%) 9(60%) 6(40%) 9(60%) ll (73%) 5(33%)

<0.03 0.63 0.69 0.69

3 (30%)

3(20%)

0.38

P Value

0.12 O.o7

P Value considered significant if <0.05; Conclusions: (1) This prospective study reveals a 40% incidence of SVf after EPP which is higher than reported previously. (2) svr did not correlate with gender, side of surgery. pathologic stage, pericardia] resection or pericarditis detected by ECG. (3) Older age was the only significant risk factor. The usefulness of prophylactic therapy for SVf in these patients is currently being studied.

PULMONARY FUNCTIONAL EVALUATION IN SEVERE OBSTRUCTION OF MAIN BRONCHI, BEFORE AND AFTER LASER RECANALIZATION Antonio Palla, MD; S Baldi, MD; M Di Tomassi, MD; A Janni, MD; GF Menconi, MD; D Mazzantini, MD; CA Angeletti, MD; C Giuntini, MD. CNR Institute of Clinical Physiology, Respiratory Pathophysiology and Thoracic Surgery, University of Pisa, Italy. Purpose: To assess pulmonary function basally and after Nd: YAG laser treatment in patients with main bronchi obstruction. Methods: 23 pts (3 females, mean age:!:SD 62:!::8 yrs) referred for palliation of symptomatic obstruction (<5 mm of caliper) of main bronchi were studied. All patients had bronchoscopy, clinical assessment, pulmonary function tests (PFT's), chest X-ray (X-ray), and pulmonary perfusion scintigraphy (PLS). On X-ray (lung volume) and PLS (lung perfusion) a% score of damage of air and blood distribution, was assigned (100%=normal). Results: Bronchoscopy showed the involvement of right main bronchus in 9 out of 23 cases, of left main bronchus in the remaining 14; 20 pts were affected by malignant neoplasms, 3had benign lesions. 21 pts were current smokers, 2 ex-smokers; 18 over 23 pts complained productive cough and dyspnea, 14 of them hemoptysis too; 14 had chest pain. Basal FVC, FEV1 and Pa02 were decreased to a higher, though not significant, amount when radiographic atelectasis (n=ll) was present and perfusion (n= 19) was absent. Comparison of PFT's, blood gas data, X-ray and PLS scores before and after laser treatment demonstrated the following statistically significant differences: FVC% of predicted 69:!::16 vs. 79:!::19, p<.005; FEV1% 60:!::14 vs. 68:!::18, p<.01; Pa02 mmHg 75:!::11 vs. 84:!::12, p<.005; X-ray score% 69:!::21 vs. 84:!::16, p<.005; PLS score% 58:!::9 vs. 72:!::16, p<.OOOl. Conclusions: Recanalization of main bronchi by laser results in remarkable improvement of pulmonary function, volume and perfusion.

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Surgery: Thoracic, continued REDUCTION PNEUMOPLASTY-QUANTIFYING DEAD SPACE & V,\/Q RELATIONSHIP Aubyn Marath MBBS FRCSE*, S Turnage MD, J Rasanen MD, D Thrush MD, R. Smith I, MS, D Solomon MD FCCP, P McKeown MD*, M Hodges 1, C Jackson t, P Preece, 1 Departments of Pulmonology, 1 Anesthesiology & *Cardiothoracic Surgery, College of Medicine, University of South Florida, Tampa, Florida Fl 33612. Purpos~: \Ye sought to detennine whether reduction in dead space and improved VAIQ relationships after performing the surgical procedure, bilateral reduction pneumoplasty, could be quantified by Multiple Inert Gas Elimination Technique analySIS (MIGET). Methods: Eight patients, submitted for pneumoplasty, underwent systemic and pulmonary artery and peripheral vein catheters placement preope ratively. Pre- and post-operatively, an injection of a solution of 6 inert gases infused into a peripheral vein was given, followed by breathing through a mouth-piece attached to a non-rebreathing valve with the nose pinched. Expired gas wa~ directed through a Wright respirometer for measurement of minute ventilation and collected. Systemic and pulmonary artery blood were sampled simultaneously, assayed for inert gas concentrations by gas chromatography, and blood-gas partition coefficientfor each inert gas determined, with separate sampling for evaluation of respiratory gas tensions, pH, hemoglobin content, and oxyhemoglobin saturation. Simultaneous mixed expired gas sampling was then assayed for ine rt gas tensions and respiratory gas tensions. Physiological dead space was determined with the Enghoff-Bohr equation. Data are summarized as mean::'::SD and were compared with Student's t test. Results: There were no differences in minute ventilation (8.3::':: 1.6 Umin), cardiac output (5.8::'::1.9 Umin), F 102 (0.24::'::0.03), Pa02 (81::'::14 mmHg), or PaCOz (48::'::7 mmHg), thus pre- and post-operative data were pooled for summary. Physiological dead space was reduced from 349::'::83 to 285::'::52 mL (p=0.12). Conclusion: Although the decrease in physiological dead space and distribution of ventilation to unperfused alveoli were not significant, there appears to be a trend, which may become better identified with longer follow-up and/or staged thoracotomy procedures.

DIAGNOSTIC VIDEO ASSISTED THORACOSCOPY (VAT) UNDER LOCAL ANESTHESIA IS FEASIBLE Hans J.M. Smit, F.M.N.H. Schramel, G. Sutedja, P.E. Posbnus, Dept. of Puhnonology, Free University Hospital Amsterdam, The Netherlands. Introduction: Traditionally, diagnostic thoracoscopy in Europe is a routine procedure performed under local anesthesia (LA) by pulmonogists (Leddenkemper, Boutin, Eur. Respir. J 1993; 6:1544). The introduction of VAT has renewed interest in extended diagnostic and therapeutic intervention in the thoracic cavity (Hazelrigg eta!. J. Thorac. Cardiovasc. Surg. 1995;109:1198). However, VAT is usually performed under general anesthesia (GA) with double lumen intubation. We recently showed that this approach increases treatment costs and hospitalisation time (Schramel et al., Eur. Respir. J. in press). Aim: Is VAT feasible under local anesthesia? Methods: 36 patients underwent VAT under LA; 27 men, 9women, mean age 48.4 yrs (range 18-83). Premedication was 0.5 mg. Atropine sc. Prior to VAT 2.5 mg Midazolam was given intraveneously (iv). Continuous 02 2l!min. was given by nasal prongs and S02 was monitored using pulse oximetry. In case of iodine talc pleurodesis 10 mg extra Midazolam and 0.1 mg Fentanyl was administered iv. Results: Excluding nights and weekends waiting time for VAT was 0.5-6 hours. All procedures were completed without conversion to GA. Mean duration of VAT was 15 minutes (8-30). S02 monitoring never showed values <95%. A mean of 2 thoracoports {l-3) was used for introduction of instruments into the thoracic cavity. No complications occurred during, nor after the procedure because of VAT or LA. The pleurodesis patients did not experience excessive pain during and after the treatment due to the retrograde amnesia caused by Midazolam and Fentanyl. 14 of 15 spontaneous pneumothorax patients received talc powder pleurodesis; 9 had emphysema-like-changes and 6 had not. In 7 cases pleural malignancy was found. In 5 patients malignant involvement of the pleura was excluded. Of 9 other cases, 2 were proven tuberculosis, 2 bacterial empyema and 5 (14%) remained unclear. Conclusion: Our feasibility study shows that diagnostic VAT can be safely performed under LA without intubation. Besides diagnostics there are therapeutic opportunities. This approach will reduce waiting time, hospitalisation time and treatment costs.

CARDIAC ARRHYTHMIAS AND MYOCARDIAL ISCHEMIA AFTER THORACOTOMY FOR LUNG CANCER Nada Vasic, MD; D Mandaric, MD; Lj Andric, MD; P Rebic, MD - Institute for Lung Diseases and TB, Clinical Center of Serbia, Belgrade, Yugoslavia

PERIOPERATIVE MORTALITY FOLLOWING PNEUMONECTOMY: RISK FACTOR ANALYSIS AND UTERATURE REVIEW Daniel E. Swartz, MD; K Lachapelle; MD, J Sampalis PhD; DS Mulder, MD; R Chiu, MD, PhD; J Wilson MD-Montreal General Hospital and McGill University, Montreal, Quebec, Canada

Purpose: To determine the incidence of cardiac complications following pneumonectomy, a group of 266 patients operated for lung cancer at the Institute for Lung Diseases and Tuberculosis in Belgrade (1992-1994) was analyzed for a period of 10 days after surgery. Methods: The study group included 243 males and 23 females with the average age of 55 yrs. Cardiological risk from surgery was registered in 44 (16%) and pulmological risk in 59 (22%) of these patients. Results: The general incidence of cardiac complications (arrhythmias, coronary ischemia, lung edema) was found in 81 (30%) patient. Arrhythmias were registered in 53 (20%) patients: atrial fibrillation in 30 (11 %), ventricular extrasystoles in 13 (5%), and supraventricular extrasystoles in lO (4%) patients. Supraventricular arrhythmias were corrected with verapamil, and ventrcular arrhythmias with mexiletine. ECG signs of coronary ischemia with anginous pain occurred in 18 (6%) patients, and acute myocardial infarction developed in 2 ( 1%) patients. Postoperative cardiogenic edema was registered in 8 (3%) patients. These complications were treated in classical way. Conclusion: Cardiac complications occur in one third of all operated patients, and in every second patient with surgical cardiopulmonary risk. Dysrhythmia and heart failure more often occurred in patients with cardiopulmological risk from surgery and following pnuemonectomy with pericardia! resection (p<0.05). Clinical Implications: Close monitoring is recommended in patients with definite pre- and perioperative risk factors for prevention of cardiac complications. Supraventricular arrhythmia~ can be corrected with verapamil, and ventricular arrhythmias with mexiJetine.

Purpose: to determine risk factors for perioperative mortality following pneumonectomy. Methods: 92 consecutive patients undergoing pneumonectomy at the Montreal General Hospital from April 1989 to 1994 were included and divided into survivor or mortality groups based on their status after 30 days. We examined the effects of age, sex, smoking history, weight loss, side of resection, tumor size, cell type, stage, pulmonary function testing, cardiovascular risks, comorbidity, preoperative blood values, duration of anesthesia, extent of resection, rerioperative fluids and urine output, chest tube duration, and duration o hospital stay on mortality. Values from the literature were reported for comparison. Results: Perioperative mortality in this series was 10.9%. Selection bias and "in-hospital" values reported in the literature has underestimated mortality with actual rates in the range of 7 to 11%. Age (OR 2.48, p=0.04), the presence of one or more comorbid diseases (OR 7.92, p=0.05) and amount of fluids given in the first 12 hours postoperatively (OR 2.21, p=0.06) were found to be significant risk factors for mortality. Multivariate logistic regression demonstrated that fluids given remains an independent risl< factor while age and comorbid disease are dependent variables. Conclusions: Our results appear consistent with previously reported mortality rates and risk factors. Patient age and concomitant disease are not modifiable while perioperative fluid administration, and other means to prevent post-pneumonectomy pulmonary edema, may reduce operative mortality. Clinical Implications: We need to question the advisability of procedure with a 10% mortality to a patient with, for example, a stage 3A lung cancer associated with a long term survival of 25%.

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