Anthony P.C. Yim

Avoiding cardiopulmonary bypass in multivessel CABG reduces cytokine response and myocardial injury

BACKGROUND Proinflammatory cytokines play a key role in the inflammatory cascade after cardiopulmonary bypass and may induce cardiac dysfunction. We compared the production of cytokines and the degree of postoperative myocardial injury in patients with multivessel coronary artery disease undergoing coronary artery bypass grafting through median sternotomy with or without cardiopulmonary bypass. METHODS Forty-four consecutive patients were studied. Patients were selected for off-pump coronary artery bypass grafting whenever complete revascularization was technically feasible. There were no differences between the two groups with respect to age, sex, symptoms, or functional class. Plasma levels of tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, and IL-10 were measured before the operation, at the end of the procedure, and 2, 4, 8, 24, and 48 hours thereafter. Levels of the MB isoenzyme of creatine kinase and cardiac troponin-I were also measured after the operation. RESULTS The number of grafts was 2+/-0.7 in the off-pump group (n = 18) and 3+/-0.8 in the cardiopulmonary bypass group (n = 26). There were no deaths or major complications in either group. Levels of tumor necrosis factor-alpha were low in both groups. No significant intergroup differences were noted regarding serial IL-6 measurements. However, IL-8 and IL-10 levels after the operation were lower in the off-pump group (IL-8, 4+/-1 versus 38+/-12 pg/mL, p < 0.01; IL-10, 5+/-2 versus 191+/-33 pg/mL, p < 0.001). Whereas postoperative creatine kinase-MB values were similar in the two groups, cardiac troponin-I levels were significantly lower in the off-pump group (8 hours, p < 0.005; 24 hours, p < 0.02, respectively). Moreover, cardiac troponin-I values 24 hours after operation correlated strongly with IL-8 levels (r = 0.61, p < 0.005), indicating that the degree of myocardial injury may be related to IL-8 production. CONCLUSIONS Compared with conventional coronary artery bypass grafting, coronary revascularization without cardiopulmonary bypass is associated with reduced cytokine responses and less myocardial injury.

VATS lobectomy reduces cytokine responses compared with conventional surgery

BACKGROUND Video-assisted thoracic surgery (VATS) lobectomy for early lung cancer has been shown to be technically feasible. Comparative studies on laparoscopic versus open procedures indicate that laparoscopy may reduce inflammatory reactions as reflected by the lesser release of cytokines. We investigated the cytokine responses following VATS and conventional lobectomy for clinical stage I lung cancer. METHODS Thirty-six patients with clinical stage I nonsmall cell lung cancer were studied. 18 patients underwent VATS lobectomy and the other 18 by conventional thoracotomy. There were no differences between the two groups with respect to age, gender, pulmonary function, smoking history, comorbidity, tumor size, and pathology. Plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, IL-8, and an antiinflammatory cytokine IL-10 were measured before surgery, at the end of the procedure, and 4, 8, 24, and 48 hours thereafter in all patients. RESULTS There was no mortality or major complication in either group. Analgesic requirement was significantly less in the VATS group. Although the release of TNF-alpha and IL-1beta were minimal after surgery in both groups, the levels of IL-6, IL-8, and IL-10 were elevated. IL-6 and IL-8 levels were significantly lower in the VATS group at the end of surgery than in the open group. In addition, reduced release of IL-10 was also observed in the VATS group shortly after surgery. CONCLUSIONS VATS lobectomy is associated with reduced postoperative release of both proinflammatory and antiinflammatory cytokines compared with the open approach. The clinical significance of these findings remains to be fully elucidated.

Thoracoscopic Talc Insufflation Versus Talc Slurry for Symptomatic Malignant Pleural Effusion

BACKGROUND Talc has been generally accepted to be the most effective sclerosant for chemical pleurodesis, although the optimal route of administration remains unclear. METHODS We designed a prospective, randomized study to compare video-assisted thoracoscopic talc insufflation with bedside talc slurry in the treatment of malignant pleural effusion. From September 1993 to November 1995, 57 patients were recruited and randomized to either video-assisted thoracoscopic talc insufflation under general anesthesia (n = 28) or talc slurry by the bedside (n = 29). Patients with poor general condition (Karnofsky score less than 30%), poor pulmonary function (forced expiratory volume in 1 second less than 0.5 L), or trapped lungs were excluded from this study. Five grams of purified talc was used for either video-assisted thoracoscopic talc insufflation or talc slurry. RESULTS There was no statistically significant difference between the two groups of patients with respect to age, sex ratio, chest drainage duration, postprocedural hospital stay, parenteral narcotics requirement, complications, or procedure failure (ie, recurrence). CONCLUSIONS Video-assisted thoracoscopic talc insufflation has not been shown to be a superior approach compared with talc slurry in our study. Because the former demands more resources, we advocate that talc slurry should be considered as the procedure of choice in the treatment of symptomatic malignant pleural effusion in patients who do not have trapped lungs.

Comparison of two-dimensional vs three-dimensional camera systems in laparoscopic surgery

AbstractBackground: The lack of depth perception and spatial orientation in video vision are the drawbacks of laparoscopic surgery. The advent of a three-dimensional camera system enables surgeons to regain binocular vision and may be advantageous in complex laparoscopic procedures. Methods: We prospectively studied two groups of surgeons (with and without experiences in laparoscopic surgery) who performed a designated standardized laparoscopic task using a two-dimensional camera system (Olympus OTV-S4) vs a three-dimensional camera system (Baxter-V. Mueller VS7700) and compared their time performances. Results: The results suggested that only experience in laparoscopic surgery had significant effect on individuals performance. We could not demonstrate any superiority of the 3D system over the 2D system. However, two-thirds of the surgeons commented that the depth perception did improve. Conclusions: With further refinement of the technology, the 3D system may improve its potential in laparoscopic surgery.

Results of video-assisted thymectomy in patients with myasthenia gravis

OBJECTIVE The efficacy of video-assisted thoracic surgery for thymectomy with myasthenia gravis has not been examined. METHODS Thirty-three consecutive patients underwent total thymectomy by video-assisted techniques between 1992 and 1995. There were 13 male and 20 female patients with a mean age of 38.42 +/- 16.88 years (range 9 to 84 years). The procedures were performed by either a right (n = 11) or left (n = 22) thoracoscopic approach and all anterior mediastinal tissue was removed. RESULTS There was no perioperative mortality or long-term morbidity. One patient required conversion of the video-assisted technique to a lateral thoracotomy. All patients except one were extubated immediately. The mean hospital stay was 4.12 +/- 6.07 days (range 1 to 37 days) with a median of 3 days. Mean follow-up is 23.39 +/- 11.72 months (range 4 to 47 months). Clinical improvement was seen in 87.9% (29/33): one of two patients (50%) in stage I, 17 of 19 (89.4%) in stage IIA, eight of nine (88.8%) in stage IIB, and three of three (100%) in stage III. Metaanalysis of these results compared with results in nine published series in which other techniques were used showed no difference in clinical improvement after thymectomy between series. CONCLUSION We conclude that video-assisted thymectomy is as effective as the traditional open surgical approaches for performance of thymectomy in the management of patients with myasthenia gravis. In addition, the improved cosmesis of the video-assisted approach ideally will lead to earlier thymectomy in patients with myasthenia gravis.

Complications and failures of video-assisted thoracic surgery: Experience from two centers in Asia

BACKGROUND There have been few specific reports on negative outcomes after video-assisted thoracic surgery. We report our combined experience from two centers in Asia. METHODS From September 1992 to April 1995, 1,337 patients were operated on with the video-assisted thoracic surgical approach. All the patients were prospectively studied. RESULTS There was one death (mortality rate, 0.07%) and 56 nonfatal complications: persistent air leaks (21), bleeding (6), wound infection (13), empyema (2), cerebrovascular accident (1), reexpansion pulmonary edema (2), deep vein thrombosis (1), prolonged ventilatory support (4), intercostal neuralgia (5), and port-site recurrence (1), giving rise to an overall nonfatal complication rate of 4.26%. Procedure failures consisted of 7 recurrences of spontaneous pneumothorax (of 407 cases or 1.7%); 2 recurrences of malignant pleural effusion (of 39 cases or 5.1%), and 2 local recurrences after resections for stage I lung cancers (of 41 cases or 4.9%). CONCLUSIONS We conclude that video-assisted thoracic surgery is safe and effective for a wide range of procedures. A learning curve is present, and careful patient selection and attention to details are essential in optimizing surgical results.

Long-term outcome after resection for bronchial carcinoid tumors

OBJECTIVES We sought to determine the long-term survival of patients treated for bronchial carcinoid tumors and whether lesser resections have had an effect on outcomes. METHODS We conducted a retrospective, multi-institutional review of patients treated surgically for primary bronchial carcinoid tumors since 1980. Operative approach, pathologic stage, histology, surgical complications, tumor recurrence, and long-term survival were assessed. RESULTS There were 50 men and 89 women with a mean age of 52.2+/-17.4 and 58.9+/-13.3 years, respectively (P=0.021). Men were more likely to be current or former smokers than were women. Operations included lobectomy or bilobectomy in 110, pneumonectomy in four, wedge resection in 22, and bronchial sleeve resection only in three patients; resection was performed thoracoscopically in six patients. One patient died postoperatively. Stages were I, 121; II, nine; III, six; and IV, three. Typical carcinoid tumors were stage I in 100 and more advanced (stages II-IV) in nine, whereas atypical carcinoid tumors were stage I in 18 and more advanced in eight (P=0. 002). Median follow-up was 43 months (range 1-149) during which 21 (15%) patients died (four from recurrent cancer) and 19 patients (14%) were lost to follow-up. Recurrent cancer developed in 2/98 patients with typical and 5/25 patients with atypical subtypes (P<0. 001; log-rank test). The likelihood of recurrence was related to histological subtype (relative risk 7.9 for atypical carcinoid; 95% confidence interval 1.4-43.5). Five-year survival was 88% for stage I patients and was 70% for patients with more advanced stages. When stratified by stage, survival was related to age (relative risk=1.9 for a 10 year increase in age; 95% confidence interval 1.2-2.9) and possibly to the histological subtype, but not to patient gender, year of operation, or type of operation performed. CONCLUSIONS Either major lung resection or wedge resection is appropriate treatment for patients with early stage typical bronchial carcinoid tumors. Survival is favorable for early stage tumors regardless of histological subtype. Local recurrence is more common among patients with atypical subtypes, suggesting that a formal resection may improve long-term outcome.

VATS major pulmonary resection revisited—controversies, techniques, and results

The application of video-assisted thoracoscopic surgery (VATS) in major pulmonary resections has remained infrequent, despite earlier demonstration of its technical feasibility. The early postoperative benefits of this approach to patients are now well documented. The intermediate to long-term clinical results of VATS major resections for primary cancer are now available and appear extremely encouraging. There are few, detailed descriptions of this technique in the literature. This article reviews the current status of VATS major resection with emphasis on its controversies, techniques, and results.

A taste of Chinese medicine

We report a case of profound anticoagulation caused by interaction between warfarin and danshen, a widely used Chinese herbal medicine, in a patient who had undergone mitral valve replacement. Patients taking warfarin should be warned not to take this herb. In addition, physicians should be alert to the possibility of an interaction with herbal medicine when anticoagulation control becomes difficult and no other causes are apparent.

Inflammatory Response to Pulmonary Ischemia–Reperfusion Injury

Lung ischemia–reperfusion (IR) injury is one of the most important complications following lung transplant and cardiopulmonary bypass. The pulmonary dysfunction following lung IR has been well documented. Recent studies have shown that ischemia and reperfusion of the lung may each play significant yet differing roles in inducing lung injury. The mechanisms of injury involving neutrophil activation, and the release of numerous inflammatory mediators and oxygen radicals also contributes to lung cellular injury, pneumocyte necrosis, and apoptosis. We herein review the current understanding of the underlying mechanism involved in lung IR injury. The biomolecular mechanisms and interactions which lead to the inflammatory response, pneumocyte necrosis, and apoptosis following lung IR therefore warrant further investigation.