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PREDICTING THYMOMA INVASIVENESS: THE ROLE OF CT SCAN. I. Goussev, J. Marschall. Department of Surgery, Royal University Hospital, University of Saskatchewan, Saskatoon, Sask.
Computer tomography (CT) remains the leading imaging modality to investigate mediastinal tumours including thymoma. However, the ability of CT to determine invasiveness of thymoma remains questionable.
Forty patients with a diagnosis of thymoma were identified using the Saskatchewan Cancer Centre database. Thirty-two patients had complete data available for analysis including CT, operative reports and pathology reports. The CT reports were compared to operative and pathology reports with pathology reports being considered the "gold standard" to determine invasiveness. CT correctly identified invasion in 9 out of 19 cases found to be invasive at operation. An additional 4 cases, totalling 23, revealed microinvasion into surrounding fat on pathologic examination. In 3 of the 9 cases demonstrating invasion, CT showed very advanced disease not amenable to surgical treatment. One of these 3 patients died soon after admission.
The sensitivity of CT in predicting invasiveness was 47.3% as compared to intraoperative diagnosis and 39.1% as compared to pathology evaluation. The accuracy of CT to predict invasion of thymoma into surrounding structures is relatively poor.
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IMMUNOHISTOCHEMICAL ANALYSIS OF N2 MEDIASTINAL LYMPH NODES. P. Nechala, R. Chibbar, R. Kennedy. Department of Surgery and Pathology, Royal University Hospital, University of Saskatchewan, Saskatoon, Sask.
The purpose of this study was to evaluate N2 mediastinal lymph nodes of non-small-cell lung cancer patients for presence of micrometastatic disease using immunohistochemistry.
Tissue blocks of N2 mediastinal lymph nodes obtained from patients with non-small-cell lung cancer were restained using ck-7, multi-ck and TTF-1 immunochemical stains. Presence or absence of micrometastases was correlated with survival data obtained from the Saskatoon Cancer Centre.
Thirty-eight patients with stage I and II non-small-cell lung carcinoma were identified and treated between January 1997 and December 2001. All patients had node-negative disease on routine histopathologic analysis and underwent resection of their primary tumour. Twenty-two of the 38 patients were identified as having micrometastases on multi-ck staining. Patients with micrometastases demonstrated a trend toward a poorer survival outcome (p = 0.13). Staining with ck-7 and TTF-1 showed no correlation with survival data.
Routine use of immunohistochemistry may help identify patients with poorer prognosis.
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IMPORTANCE OF NODAL STATUS AND IMPACT OF MEDIASTINOSCOPY IN PREOPERATIVE STAGING OF PATIENTS WITH MALIGNANT PLEURAL MESOTHELIOMA. M. de Perrot, Y. Shargall, T.K. Waddell, R.J. Ginsberg, G. Darling, A.F. Pierre, S. Keshavjee, M.R. Johnston. Division of Thoracic Surgery, Toronto General Hospital, University of Toronto, Toronto, Ont.
Introduction: The presence of metastatic lymph nodes (LN) is a factor of poor prognosis in patients with malignant pleural mesothelioma. However, the value of mediastinoscopy in the preoperative staging of malignant pleural mesothelioma has not been analyzed systematically. We have, therefore, evaluated the importance of metastatic LN and the impact of mediastinoscopy in the treatment of malignant pleural mesothelioma. Methods: Retrospective review of 33 consecutive patients (25 men and 8 women, median age 58 yr) with malignant pleural mesothelioma undergoing extrapleural pneumonectomy (EPP) between 1993 and 2002 in our institution. Results: Tumours were right- (n = 14), or left-sided (n = 19). Perioperative mortality was 6% (2 deaths) and morbidity 33%. Although all patients had small (< 1.5 cm in greatest diameter) and non-suspect mediastinal LN on preoperative computed tomography (CT), 15 patients presented with extrapleural metastatic LN (45%) and 3 with intrapleural metastatic LN (9%) on final pathologic examination after EPP. Recurrence rate was significantly higher in patients with metastatic LN than in patients with N0 LN status (2-yr disease-free survival of 14% versus 54%, respectively; p = 0.009). Mediastinoscopy was performed preoperatively in 18 patients and was positive for metastatic mediastinal LN in only 1 patient. Of the 17 patients with negative mediastinoscopy, 9 were found to have extrapleural metastatic LN on final pathology. Metastatic LN were located in the aortopulmonary window, along the phrenic nerve, and in the lower mediastinum in 4 of these patients and, thus, were not accessible by cervical mediastinoscopy. The remaining 5 patients had metastatic LN along the trachea or in the subcarinal space that were not detected by mediastinoscopy. Conclusions: Metastatic LN is an important predictor of outcome that may help to select patients for EPP. However, in our experience, the negative predictive value of mediastinoscopy to detect extrapleural nodes is low (47%) and not significantly different from CT (44%). The low yield of mediastinoscopy in detecting metastatic LN may be due to the distribution of metastasis outside of the regions easily accessible by cervical mediastinoscopy and to the difficulty to detect small clusters of mesothelial cells on samples obtained by mediastinoscopy.
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15 YEARS' SINGLE-CENTRE EXPERIENCE WITH SURGICAL RESECTION OF THE SUPERIOR VENA CAVA FOR NON-SMALL-CELL LUNG CANCER. G. Darling, Y. Shargall, M. De Perrot, S. Keshavjee, M. Ginsberg, A. Pierre, T. Waddell. Toronto General Hospital, University of Toronto, Toronto, Ont.
Objectives: The role of surgical resection for locally advanced non-small-cell lung cancer (NSCLC) invading the superior vena cava (SVC) is controversial. We examined our results in this group of patients. Methods: Retrospective analysis of patients who underwent surgical resection for NSCLC with direct SVC involvement, between 1988 and 2003. Postoperative morbidity and long-term outcome were reviewed. Risk factors for overall and disease-free survival were examined using Kaplan-Meier methods and log-rank test. Results: Of 21 patients who underwent SVC resection for thoracic malignancies, 13 were operated upon for NSCLC (7 males, 6 females). Median age was 60 years (28-78). None had SVC syndrome preoperatively. All patients had direct SVC invasion by tumour. All underwent mediastinoscopy as part of their staging. Six patients with N2 disease (discovered during mediastinoscopy in 5, and based on CT scan in 1) received induction therapy. Nine underwent lobectomy, and 4 had pneumonectomy (2 carinal). The SVC was replaced by interposition graft in 8 patients, whereas 5 had partial resection and repair. There were 2 (15%) postoperative deaths secondary to respiratory failure, and 3 (23%) major morbidities (1 postop SVC syndrome, 1 recurrent laryngeal nerve palsy and 1 cardiac herniation). No SVC-related late morbidities were observed. Mean follow-up time was 22 months (1-132, median 9). Overall 1- and 3-year survivals were 74% and 40%, respectively. Disease-free survival was 67.5% and 30%, respectively. All late deaths were due to recurrence. Survival of those with N2 disease was not significantly worse than those with localized (N0/N1) disease. There was a trend towards delay in recurrence in patients who had induction therapy (median disease-free interval of 34 mo v. 10 mo in the untreated group) although there was no significant effect on overall survival. The extent of lung resection and type of SVC resection (repair v. replacement) were not found to influence long-term survival. Conclusions: Carefully selected patients with NSCLC and SVC involvement can be operated upon with acceptable postoperative morbidity and mortality. In this small group of patients, no significant prognostic factors could be identified. SVC resection with curative intent should be considered for patients with NSCLC involving the SVC.
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MINI-INVASIVE TRANSAXILLARY UPPER LOBECTOMY FOR LUNG CANCER PATIENTS. H. Lara-Guerra, J. Clifton, K. Evans, R.J. Finley. Division of Thoracic Surgery, Department of Surgery, Vancouver General Hospital, University of British Columbia, Vancouver, BC
The purpose of this study is to report the experience of the Thoracic Surgery Service at the Vancouver General Hospital with lung cancer patients who underwent upper lobectomy by video-assisted procedure.
Retrospective chart review was carried out of patients with lung cancer who underwent upper lobectomy at Vancouver General Hospital between 1995 and 2001. They were divided into video-assisted, transaxillary lobectomy (VATSL) performed by surgeon 1 (group 1, n = 32), posterolateral thoracotomy (PLTL) by surgeon 1 (group 2, n = 24) and PLTL by surgeon 2 (group 3, n = 22). Demographic data, medical history, preoperative risk factors, surgical data and hospital stay information were recorded. Unpaired t-tests and [Symbol Not Transcribed] [chi][Symbol Not Transcribed] were performed using significance levels of p < 0.05.
Group 1 showed a shorter total operating time than group 2 (186.9 v. 203.7 min, p = 0.043). Group 1 reported lower pain levels throughout hospital stay (p < 0.05 at 1st, 5th, 6th and 7th days) and used epidural catheter less times (p < 00.1) and received less epidural drugs (38.5 v. 119.7 mL, p = 0.000).
Comparison of group 1 with group 3 showed that VATSL reported lower pain levels throughout hospital stay (p < 0.05 at 1st, 3rd, 6th and 7th days) and needed less Leritine and epidural analgesic drugs (176.6 v. 570.8 mg, p = 0.019; 38.6 v. 132.4 mL, p < 0.000).
Group 1 compared to groups 2 + 3 confirmed the following: group 1 reported lower pain levels at 1st, 3rd and 5th days (p < 0.05). Epidural catheter was indicated less times for group 1 (p < 0.000). Total mg of morphine IV were higher in VATSL (p = 0.03) but paracetamol and Leritine were lower (p = 0.053 and p = 0.02, respectively).
This study suggests that lung cancer patients who underwent upper lobectomy by VATS presented lower pain levels with less-invasive analgesic management. The results indicate the need to conduct a randomized controlled trial with sufficient power and sample size to answer these questions.
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A QUANTITATIVE APPROACH TO MAXIMIZING UTILIZATION OF SURGICAL RESOURCES FOR ELECTIVE OPERATIONS. A. Behzadi, R. Borgesa, H. Unruh, S. Bhatt. I.H. Asper School of Business, University of Manitoba, Section of Thoracic Surgery, Health Sciences Centre, Winnipeg, Man.
The objective of this project was to devise a linear program based on quantitative approach of management science, which can then be used as a tool by the hospital managers and surgeons to maximize utilization of surgical services and resources for elective operations.
This maximization approach to resource management was focused on 4 commonly performed elective pulmonary operations in a thoracic surgery section of a tertiary-care hospital. Using linear programming formulation, a maximization model was constructed. The model looks at 8 constraints: minimum number of operations of each type, maximum number of operating room hours, number of available hospital beds, number of operating room nurses, number of anesthetists, recovery room beds, intensive care unit beds, and number of nurses on the ward. All the constraints were then quantified into the number of hours per month. The program was formulated based on 2 core alternative pathways. First, the demand for the surgical services made by a surgeon exceeds the available resources, and second, the resources offered to the surgeon exceeds or is equal to the surgeon's demand.
The linear programming model was able to provide 2 sets of information. In situations where demand exceeded the available resources, the program was able to identify and quantify what constraints are the limiting elements. In other situations where resources matched or exceeded the demand, the program could identify and quantify the underused resources, and suggest which operations and in what quantities -- from the pool of operations already designed into the program -- can be added to the schedule.
Using our linear program as a blueprint, a more extensive model can be formulated that encompasses the activities of all the surgical services. This model will then allow for optimal utilization of the available resources to accommodate elective surgeries in a hospital.
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CASPASE INHIBITION DECREASES APOPTOSIS AND LEADS TO IMPROVED LUNG FUNCTION IN A RAT MODEL OF LUNG TRANSPLANTATION. S.M. Quadri, L. Segall, A. Dutly, V. Edwards, B. Mullen, N. Jones, T.K. Waddell, M. Liu, S. Keshavjee. Thoracic Surgery, University Health Network -- Toronto General Hospital, Pathology, Mt. Sinai Hospital, Gastroenterology, Hospital for Sick Children, Toronto, Ont.
Previously, we have described significant apoptotic cell death in the lung following transplantation in humans and animals. Multiple pathways lead to programmed cell death; it is not known which are relevant in lung transplantation. Furthermore, the clinical significance of this cell death has not been studied.
In randomized blinded studies, syngeneic left single-lung transplantation (Lewis rats) was performed after 6 hours (n = 15) and 18 hours (n = 8) of cold ischemic storage (CIT). Animals and storage solutions were treated with caspase inhibitors or control. After transplantation and reperfusion, the PO[Symbol Not Transcribed] level of the transplanted lung at FiO[Symbol Not Transcribed] 1.0 was used to assess lung function. Caspase 3, 8 and 9 activities in lung tissue lysates were measured through fluorometric assays. Lung samples were subjected to electron microscopy; TUNEL was used to evaluate apoptosis in paraffin-embedded lung sections.
After 6 hours CIT, transplantation and 2 hours reperfusion, the PaO[Symbol Not Transcribed] levels, at FiO[Symbol Not Transcribed] 1.0, were not significantly different. However, after 18 hours CIT, transplantation and 2 hours reperfusion, the PaO[Symbol Not Transcribed] levels at FiO[Symbol Not Transcribed] 1.0 were significantly higher in the caspase inhibitor group as compared to control. Caspase 3, 8 and 9 activities rose dramatically from baseline to 6 hours CIT and then dropped back down by 18 hours CIT in control animals. Animals treated with caspase inhibitor did not exhibit any significant changes in caspase activities. Electron microscopy demonstrated apoptotic cell death in endothelial cells and lymphocytes in control animals. TUNEL studies show that apoptosis was significantly reduced in animals treated with caspase inhibitor.
Activation of caspases during cold ischemia contributes significantly to ischemia-reperfusion induced apoptosis of endothelial cells and lymphocytes in lung transplantation. A systemically administered pan-caspase inhibitor successfully inhibited caspase activity in the lung, led to decreased TUNEL positivity, and improved lung function after 18 hours CIT, transplantation and 2 hours reperfusion.
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LEVELS OF EVIDENCE AND GRADES OF RECOMMENDATIONS IN GENERAL THORACIC SURGERY. A.J. Graham, G. Gelfand, S.D. McFadden, S.C. Grondin. Division of Thoracic Surgery, University of Calgary, Calgary, Alta.
To determine the grades of recommendations and levels of evidence available if the formal practice of evidence-based medicine (EBM) is applied to general thoracic surgery.
Three general thoracic surgeons, by consensus developed a sample of 10 clinically important questions. The first 3 steps of evidence-based medicine (creation of answerable clinical questions, search for best external evidence, and. critical appraisal of literature) were performed. The best evidence found was categorized according to the Oxford Centre for Evidence-Based Medicine, grades of recommendations (A-D) and level of evidence (1-5).
Abstracts and appropriate articles were identified through MEDLINE January 1999-December 2001. A hierarchial series of search strategies was employed to identify the best level of evidence in order of systematic reviews then randomized controlled trials or other types of evidence.
The best evidence found for the 10 sample questions was categorized as grade A recommendations in 7 and grade B recommendations in 3. The levels of evidence found were 1a in 2 studies, 1b in 5, 2a in 1 and 2b in 2.
A formal evidence-based-medicine approach to general thoracic surgery found the grades of recommendation and levels of evidence for a sample of clinically important questions was high.
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A PHASE II TRIAL OF INDUCTION CHEMOTHERAPY FOLLOWED BY EXTRAPLEURAL PNEUMONECTOMY AND HIGH-DOSE HEMITHORACIC RADIATION FOR MALIGNANT PLEURAL MESOTHELIOMA. M. de Perrot, R.J. Ginsberg, D. Payne, R. Feld, G. Darling, T.K. Waddell, S. Keshavjee, M.R. Johnston. Toronto General Hospital and Princess Margaret Hospital, University of Toronto, Toronto, Ont.
Introduction: We performed a single institution phase II trial with induction chemotherapy followed by extrapleural pneumonectomy (EPP) and high-dose hemithoracic radiation therapy for malignant pleural mesothelioma. Methods: Patients were eligible if they had a diagnosis of malignant pleural mesothelioma, a resectable tumour on computed tomography (CT) and adequate cardiopulmonary reserve to undergo EPP. Patients received 2-3 cycles of cisplatin/navelbine before EPP, and hemithoracic radiation (54 Gy) after EPP. Results: Between 06/01 and 12/02, 18 patients (13 men and 5 women, median age 59 yr) were eligible for the study. Nine patients (50%) completed the protocol. Two patients declined preoperative chemotherapy, 2 were found to have extensive disease at surgery and did not undergo EPP and 5 did not receive postoperative radiation therapy. Chemotherapy was performed in 16 patients and was well tolerated in all but 1 patient (fever and tachycardia). Chest CT was performed before and after chemotherapy to assess the response. Nine patients had no change in the bulk of disease, whereas 3 had minimal improvement and 1 had a partial response. Three patients had an increase in the size of the tumour during chemotherapy, and 2 of these were unresectable at surgery. Out of 16 patients undergoing EPP, 1 died postoperatively of arrhythmia and 7 developed complications (atrial fibrillation n = 2, recurrent nerve palsy n = 2, mild temporary kidney dysfunction n = 1, wound infection n = 1, and esophageal perforation n = 1). Eleven patients received postoperative hemithoracic radiation therapy to a total dose of 54 Gy. Fatigue (n = 8), skin erythema (n = 6), nauseas (n = 4) and esophagitis (n = 3) were often seen, but no major complications were observed. The 1-year disease-free survival for the 9 patients who completed the protocol was 74%, and tended to be better than for the remaining patients who underwent EPP but did not complete the protocol (1-year disease-free survival of 33%, p = 0.2). Conclusions: Induction chemotherapy followed by EPP and high-dose hemithoracic radiation is an aggressive but tolerable regimen for selected patients with malignant pleural mesothelioma. This approach may delay recurrence and improve survival. New chemotherapy regimens are needed to increase the response rate before surgery.
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A TWELVE-YEAR EXPERIENCE WITH ESOPHAGEAL RESECTION FOR MALIGNANT DISEASE OF THE ESOPHAGUS IN THE REGINA HEALTH DISTRICT. L.R.S. Dewar. Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Regina-Qu'Appelle Health Region, University of Saskatchewan, Regina, Sask.
The outcome of all surgical resections of the esophagus or gastroesophageal junction (GEJ) for malignant disease undertaken in all 3 hospitals of Regina from Jan. 1, 1989-Dec. 31, 2001 was retrospectively reviewed. A total of 129 patients were taken to the operating room; 119 underwent esophageal resection. Ten procedures were abandoned due to unresectable disease.
There were 16 postoperative deaths (13.4%). Perioperative morbidity was high, with 26 patients experiencing anastomotic leaks (21.8%); anastomotic strictures occurred in 32 patients (26.9%). Respiratory complications were frequent with 22 patients (18.5%) developing respiratory failure postoperatively requiring reintubation and ventilation (for a mean of 202.8 h). Atelectasis occurred in 102 patients (85.7%), pulmonary edema in 30 patients (25.2%), pneumonia in 21 patients (17.6%) and aspiration documented in 9 patients (7.6%).
Resource utilization was extensive with a mean hospital length of stay of 23.9 days (range 0-196 d). The mean ICU stay was 5.4 days (range 0.2-32 d).
Procedures were carried out by 14 members of the Divisions of General Surgery or Cardiovascular and Thoracic Surgery in the 3 Regina hospitals. Individual surgeon experience ranged from 1-46 cases over the 12-year interval. Perioperative mortality rates by individual surgeon ranged from 0%-50%.
The Regina-Qu'Appelle Health Region's Department of Surgery lacks a defined management pathways for malignant diseases of the esophagus or GEJ. Individual surgeon volumes are generally low and may contribute to high perioperative mortality and morbidity rates observed in the Regina Hospitals. Development of a specialized unit to maximize clinical experience of health care providers would appear to be a reasonable approach to improve patient outcome.
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CONTEMPORARY MANAGEMENT OF RUPTURE OF THE DESCENDING THORACIC AORTA. R. Karmy-Jones. Division of Cardiotheoracic Surgery, Harborview Medical Center, Seattle, Wash.
Objectives: To evaluate to the current role(s) of CT angiogram (CTA), nonoperative and endovascular approaches in managing traumatic thoracic aortic rupture (TAR). Methods: A retrospective review of patients admitted between 02/1998-3/2003 with injuries in the descending thoracic aorta. Patients were categorized as unstable if systolic pressure < 90 within 1 hour of admission. Repair was emergent if performed < 24 hours after admission, delayed if > 24 hours. Results: 46 (38 male, age 37.8 [Symbol Not Transcribed] [plus or minus] 18.4 yr, Injury Severity Score 43.5 [Symbol Not Transcribed] [plus or minus] 15.6) patients were admitted with overall mortality 12 (26%) due to: free rupture prior to control (3), closed head injury (2), cardiac causes (4), pulmonary embolism (1), late bleed (1), ARDS (1). Mortality by category was as follows: emergent (including 3 with free rupture) 10/32 (31%) versus delayed 2/8 (25%) versus nonoperative 0/6; stable 5/36 (14%) versus unstable 7/10 (70%); operative repair 9/30 (30%) versus endovascular stent graft 3/10 (30%). Multi-regression analysis identified that stable patients were 5.7 times more likely to survive than unstable (CI 2.0-15.6). The diagnosis was made by angiogram in 29 (63%) cases, including 6 at the time of embolization and by CTA in 17 (37%). Time to operating room in the urgent group was 2.9 [Symbol Not Transcribed] [plus or minus] 1.4 hours after CTA versus 4.4 [Symbol Not Transcribed] [plus or minus] 1.5 hours after angiogram (p = 0.02). The most common indication for not performing emergent intervention was acute lung injury (7), and no patient in the delayed and nonoperative groups (11/13 treated with beta blockade) suffered free rupture. Conclusions: Selective use of endovascular stent grafts and nonoperative therapy is appropriate. Mortality is primarily linked to patient stability. Angiograms should be used to make the diagnosis if embolization is required, but CTA [may] be quicker in other cases.
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VATS SYMPATHECTOMY AND SYMPATHICOTOMY IN PATIENTS WITH PRIMARY PALMAR HYPERHIDROSIS. S. Keshk. Department of Cardiothoracid Surgery, Alexandria University, Alexandria, Egypt
VATS sympathectomy is the most frequently used technique for surgical hyperhidrosis of the upper limbs. It has proven to be particularly effective. Objective: To evaluate the role of VATS in management of palmar hyperhidrosis. Patients and methods: 40 cases undergoing VATS for palmar hyperhidrosis, in 2 groups. Group I 20 patients (sympathectomy), group II 20 patients (sympathicotomy). Results: Mean operation time 23.47 [Symbol Not Transcribed] [plus or minus] 2.85 minutes in resection, and 18.87 [Symbol Not Transcribed] [plus or minus] 2.07 minutes in division. The mean duration of the operation was significantly longer in group I when compared with group II. Main outcome measures included incidence of dry hands, compensatory hyperhidrosis and recurrence. After both procedures 100% reported significant improvement of palmar hyperhidrosis. Post-surgery compensatory hyperhidrosis was experienced in 3.3% of cases, and 6.66% showed partial recurrence. VATS is a very useful, speedy and safer way than conventional thoracotomy in managing cases of palmar hyperhidrosis, with excellent cosmetic results while minimizing complications.
