Effect of endothelin receptor antagonist on lung allograft apoptosis and NOSII expression

BACKGROUND

It is postulated that apoptosis contributes to ischemia-reperfusion graft dysfunction after lung transplantation. The purpose of this study was to determine whether the improvement in lung function that we previously observed with the use of an endothelin-1 (ET-1) receptor antagonist after ischemia-reperfusion injury is associated with a reduction in inducible nitric oxide synthase (NOSII) expression and programmed cell death.

METHODS

Left lung canine allotransplantation was performed. Harvested lung blocks were preserved with modified Eurocollins solution and stored at 4 degrees C for 18 to 20 hours. Lung allografts were tested for the expression of NOSII by immunohistochemistry, and extent of apoptosis by terminal dUTP nick end-labeling (TUNEL). Animals blindly received either an intravenous infusion of saline (control) or the ET-1 receptor antagonist (SB209670) (15 microg/kg/min). Infusion began 30 minutes pretransplantation and continued to 6 hours posttransplantation.

RESULTS

Immunohistochemical analysis demonstrated significantly stronger NOSII immunostaining in the allografts of the saline control group (36.5%+/-3.6%) compared with native right lungs (6.9%+/-1.3%, p < 0.001) or the ET-receptor antagonist treatment group (9.6%+/-1.4%, p < 0.001). The TUNEL staining revealed a significantly stronger labeling in the allografts of the saline treatment control group (40.7%+/-6.2%) compared with native right lungs (5.0%+/-0.6%, p < 0.005) or the ET receptor antagonist treatment group (14.1%+/-2.8%, p < 0.01).

CONCLUSIONS

We conclude that treatment of lung allografts with the ET-1 receptor antagonist SB209670 reduces the area of NOSII expression and the extent of apoptosis, factors known to contribute to the process of prolonged ischemia-reperfusion injury.

Nitric oxide system in needle-induced transmyocardial revascularization

BACKGROUND

Nitric oxide (NO) promotes endothelial proliferation and migration, essential for angiogenesis. The purpose of this study was to determine the cellular expression of inducible and endothelial nitric oxide synthases (iNOS and eNOS) in an ischemic cardiomyopathy animal model of needle-induced transmyocardial revascularization (TMR).

METHODS

Myocardial infarction was created in rats by ligating the left coronary artery, and animals were divided into two groups: no-TMR group (served as control) and TMR group (underwent concomitant TMR by the creation of six transmural channels with a 25-gauge needle in the ischemic area). Rats were sacrificed at intervals of 1, 2, 4, and 8 weeks. Immunohistochemistry using specific antisera was performed for iNOS, eNOS, and endothelial cell marker factor VIII. Vascular density and positive staining area with either iNOS or eNOS were assessed in the infarcted myocardium.

RESULTS

Vascular density in the infarcted myocardium was significantly increased in the TMR group (p < 0.001). The positive staining area for iNOS and the intensity of iNOS immunoreactivity in cardiomyocytes, vascular endothelium, and macrophages were significantly greater in the TMR group (p < 0.05). However, these differences were seen only in the first 2 weeks after TMR. There was no significant difference in the expression of eNOS between groups.

CONCLUSIONS

A mechanical injury using needle puncture in an ischemic myocardium increased vascular density and is associated with increased expression of myocardial iNOS. Increased production of NO derived from iNOS may contribute to the angiogenic response of TMR.

Successful retrieval and function of lungs from non-heart-beating donors

BACKGROUND

Lung transplantation has been used effectively as a therapeutic tool in end-stage pulmonary diseases, but organ shortages have restricted its use. There is growing interest in alternative organ sources such as organs from circulation-arrested cadavers, so called non-heart-beating donors.

METHODS

We examined the effects of postmortem rapid in situ cadaver lung cooling by bilateral chest cavity flushing (group 2) and by pulmonary artery flush through right heart catheterization followed by pleural cavity flushing (group 3) on pulmonary function and morphology in a rabbit non-heart-beating donor model. The results were compared with those in a control group of heart-beating donors (group 1).

RESULTS

At the end of a 2-hour reperfusion period, there were no significant differences in mean pulmonary artery pressure, pulmonary vascular resistance, pulmonary compliance, arteriovenous oxygen, pulmonary wet to dry weight ratio, and lung morphology between the three groups.

CONCLUSIONS

Our study demonstrates that using bilateral chest cavity flushing with or without pulmonary flush protects the function and morphology of cadaver lungs and renders them suitable for lung transplantation.

Endothelin receptor antagonist SB209670 decreases lung allograft apoptosis and improves lung graft function after prolonged ischemia

Apoptosis has been postulated as a contributing factor in ischemia-reperfusion graft dysfunction following lung transplantation. The purpose of this study was to determine whether treatment with an endothelin-A/endothelin-B- (ET(A)/ET(B)) receptor antagonist could reduce the level of apoptosis observed in the lung following ischemia-reperfusion injury. Eleven dogs were subjected to left lung allotransplantation. Heart-lung blocks were harvested from donor dogs and preserved with modified Eurocollins solution and stored at 4 degrees C for 18 to 20 h. We investigated the level of apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), in the lungs of animals receiving an intravenous infusion of saline (control, n = 5) or the ET receptor antagonist SB209670 (n = 6) (15 microg/kg/min). The infusion began 30 min prior to transplantation and continued for up to 6 h thereafter. The TUNEL staining was significantly higher in the airway epithelium and the parenchyma of the saline (control) group (40.67 +/- 6.16), compared with native right lungs (5.00 +/- 0.56) and the treatment group (14.13 +/- 2.84). We conclude that treatment of lung allografts with the mixed ET(A)/ET(B)-receptor antagonist SB209670 can ameliorate lung injury by reducing the level of apoptosis seen in the allograft following ischemia-reperfusion injury.

Right heart circulatory support facilities coronary artery bypass without cardiopulmonary bypass

BACKGROUND

Revascularization of the posterior wall often causes hemodynamic instability in beating heart coronary artery bypass (CAB). Our previous clinical studies have shown that tilting the heart primarily alters right-heart hemodynamics. The purpose of this study was to evaluate right-heart support in clinical cases.

METHODS

Seventeen patients underwent beating heart CAB with right-heart support. The right-heart support system (A-Med Systems, West Sacramento, CA) consisted of a coaxial cannula placed through the right atrium and the tip of the cannula positioned in main pulmonary artery. Blood was removed from the right atrium and returned to the main pulmonary artery.

RESULTS

Elective beating heart CAB was accomplished successfully in 17 patients with right-heart support. Anastomoses performed were left anterior descending coronary artery (11), diagonal (3), circumflex (5), obtuse marginal artery (11), and right coronary artery (10). Right-heart support between 1 and 3 L/min improved hemodynamics especially in the circumflex position. No device-related patient incidents occurred, nor were there incidents of infection or air embolism. All 17 patients were discharged to their homes.

CONCLUSIONS

The right-heart support system was safe without complications. Exposure of the posterior wall was possible in all cases without hemodynamic compromise.

An automated interrupted suturing device for coronary artery bypass grafting: automated coronary anastomosis

BACKGROUND

The purpose of this study was to have a preliminary assessment of the safety and efficacy of an automated vascular suturing device.

METHODS

The device (Heartflo, Perclose/Abbott Labs, Redwood City, CA), which delivers 10 interrupted 7-0 polypropylene sutures between side-to-side arteriotomies, was evaluated in animals (8 Yorkshire pigs).

RESULTS

Tissue edge capture and quality of anastomosis were highly rated. Time of anastomoses averaged 22 minutes. This time was prolonged primarily due to suture management, tying of interrupted sutures, and learning curve effects. Six of the anastomoses were hemostatic and two required an additional stitch each. Angiography and histology of the anastomosis confirmed patency and quality of the anastomosis.

CONCLUSIONS

Our preliminary results indicate that the Heartflo automated anastomotic device is safe and effective. Preclinical and clinical studies to validate its acute and long-term effectiveness will commence shortly.

Inhibition of cyclooxygenase-2 improves cardiac function in myocardial infarction

Induction of cyclooxygenase-2 (COX-2) in ischemic myocardium is thought to increase the production of proinflammatory prostanoids and contribute significantly to the ischemic inflammation. Left ventricular myocardial infarction (MI) was created by ligating the left coronary artery in Lewis rats. Hemodynamic measurements at 4 weeks showed better cardiac function in the group treated with a selective COX-2 inhibitor (DFU; 5 mg/kg/day) for 2 weeks after induction of MI compared to the vehicle treated group. These results suggest that induction of COX-2 contributes to myocardial dysfunction, and that selective inhibition of COX-2 could constitute an important therapeutic target for the treatment of MI.

Tools for precision enhancement in minimally invasive cardiac surgery: three dimensional visualization, computer enhancement and robotics

This article is a current update of the rationale for development of new enabling technologies in minimally invasive cardiac surgery. Specifically the potential advantages of three dimensional visualization, computer enhancement technology and robotics in performance of totally endoscopic coronary artery bypass grafts will be addressed.

Sublobar resection for lung cancer

The role of limited lung resection 'segmentectomy and wedge resection' in the treatment of lung cancer has been reviewed. Survival for patients with stage I lung cancer and lesions less than 2 cm is comparable to that of major resections such as lobectomy. The theoretical advantage of limited resection is the simplicity of the procedure and the potential for performing it through lesser invasive techniques. The major drawback at this time which should render it a compromise rather than a choice operation is the increased risk of locoregional recurrence. Until properly conducted clinical trials validate its efficacy in peripheral T1 lung cancer with or without adjuvent therapy, sublobar resection should be limited to patients that are at poor risk of tolerating major lung resection. Sublobar resections however may also play a useful role in treatment of metachronous or synchronous lung cancer.

Coronary artery bypass grafting on the beating heart: a simple technique for subluxating the heart

Coronary artery bypass grafting on the beating heart is becoming a widely applied procedure. It necessitates proper cardiac stabilization without impairment of hemodynamics. We describe a simple and effective technique to bring the anterolateral coronary arteries to a midline position for the purpose of performing a coronary artery bypass graft on the beating heart. A surgical glove tied to a tube is positioned underneath the left ventricle. Injection of warm saline into the glove will gradually displace the heart and rotate the lateral wall of the ventricle to a midline position. In spite of our use of mechanical stabilizers to decrease mobility of the anastomotic site, compression of the left ventricle is avoided because the water bed created by the injected glove absorbs the movement of the left ventricle and prevents its compression and any potential drop in cardiac output.

Robotic computer-assisted telemanipulation enhances coronary artery bypass

OBJECTIVES

Totally endoscopic coronary artery bypass grafting depends greatly on perfecting the anastomosis. We tested a new computer-assisted telemanipulation robot (Intuitive Surgical Inc, Mountain View, Calif) in performing endoscopic coronary bypass.

METHODS

On-bench anastomoses of the porcine arterial graft to the left anterior descending coronary artery were performed with both direct visualization and conventional surgical instruments (group I), endoscopic 3-dimensional visualization and current endoscopic surgical instruments (group II), direct visualization and endoscopic instruments (group III), 3-dimensional endoscopic visualization and conventional surgical instruments (group IV), and telemanipulation robotic with 3-dimensional endoscopic visualization (group V). Anastomoses (n = 6 in each group) were assessed for time (minutes), quality (good = 3, fair = 2, poor = 1), technical difficulty (easy-difficult: 1-4), and patency (100% = 1, >50% = 2, <50% = 3).

RESULTS

Anastomotic time was significantly longer in groups II and III than in groups IV and V (P </=.02). Patency was comparable in all groups.

CONCLUSION

Telemanipulation technology may enhance the performance of totally endoscopic coronary artery anastomosis. The facility and time of an Intuitive telemanipulation anastomosis is comparable with that of a conventional anastomosis created under direct vision.

Maximal exercise capacity and peripheral skeletal muscle function following lung transplantation

BACKGROUND

There have been many suggestions that diminished exercise capacity in patients that have undergone lung transplantation is due, in part, to peripheral muscle dysfunction, brought on by either detraining or immunosuppressive therapy. There is limited data quantifying skeletal muscle function in this population, especially in those more than 18 months post-procedure. The present study sought to quantitate skeletal muscle function and cardiopulmonary responses to graded exercise in 19 lung transplant recipients, 15 of which were mostly more than 18 months post-procedure.

METHODS

Ten single- (SLT) and 9 double-lung transplantation (DLT) underwent anthropometric measures and performed expiratory spirometry, whole body plethysmography to assess lung volumes, static maximal mouth pressures to assess respiratory muscle strength, progressive exercise testing on a cycle ergometer (with cardiac output measurements being performed every second workload) and isokinetic cycling to assess peripheral muscle power and work capacity.

RESULTS

The DLT group was younger than the SLT group (23.0 [21.0-32.0] vs 47.5 [43.0-55.0] median [interquartile range], p < .05) with no differences in height, weight, or BMI. Despite the DLT group having significantly better spirometric values (FEV1: 86% vs 56.5% median) and less airtrapping (RV/TLC: 30% vs 53.5%), both groups were equally limited in exercise capacity (Wmax)(38.0 percent predicted [30.0-65.0] vs 37.5 percent predicted [30.0-44.0], SLT vs DLT), leg power (76.1 percent predicted [53.8-81.4] vs 69.0 percent predicted [58.3-76.0]) and leg work capacity (63.3 percent predicted [34.7-66.8] vs 38.4 percent predicted [27.5-57.3]). This lack of difference in performance persisted when the analysis was limited to those more than 18 months post-procedure. Respiratory muscle strength was also not different for the two groups, and was within normal limits. Wmax was best correlated with leg work capacity (r = .84), but also with leg power, RV/TLC, FEV1 (r = .49, -.52, .58). When normalized for age, height, and sex, percent predicted Wmax only correlated with percent predicted leg work capacity (r = .58). Cardiac output was appropriate for the work performed.

CONCLUSIONS

We conclude that peripheral skeletal muscle work capacity is reduced following lung transplantation and mostly responsible for the limitation of exercise performance. While the causes of muscular dysfunction have yet to be clarified, the preservation of respiratory muscle strength with the concomitant reduction in leg power and work capacity suggests that most of the muscular dysfunction post-transplantation is attributable to detraining.

Endothelin receptor antagonist improves pulmonary hemodynamics during lung ischemia/reperfusion injury

BACKGROUND

We have previously shown that elevated release of endothelin-1 is associated with increased pulmonary vascular resistance (PVR) immediately after reperfusion of the transplanted lung. In the present study, we investigated the effect of ET receptor blockage on pulmonary hemodynamics and function in an ex vivo lung reperfusion model after 6 hr of cold ischemia.

METHODS

Eighteen rabbits were divided into three groups: no ischemia followed by 3 hr of reperfusion (group I) and 6 hr of cold ischemia followed by 3 hr of reperfusion with either blood (group II) or blood + SB209670 (mixed ETA/ETB receptor antagonist) (group III).

RESULTS

Shortly after reperfusion, mean pulmonary artery pressure, PVR, and pulmonary edema were increased, and pulmonary compliance and PO2 were decreased in group II compared with group I. Treatment with SB209670 resulted in a significant decrease in mean pulmonary artery pressure, PVR, and pulmonary edema, and improvement in pulmonary compliance and PO2.

CONCLUSION

The data suggest an important role for ET-1 in lung ischemia/reperfusion injury and that the use of ET receptor antagonist immediately after transplantation may provide a new therapeutic tool in the management of early graft dysfunction.

Arterial graft patency in coronary artery bypass grafting: what do we really know?

BACKGROUND

With increasing use of beating heart techniques for bypass of the left anterior descending coronary artery with the left internal mammary artery (LIMA), appropriate concerns have been raised of whether graft patency by these techniques compares favorably with conventional, arrested heart techniques.

METHODS

All published articles that examine outcome efficacy of the LIMA graft to the left anterior descending coronary artery were reviewed. Because angiography has been considered the "gold standard," only those studies that included angiographic follow-up were analyzed.

RESULTS

From 1972 through 1998, there have been 37 peer-reviewed publications that examined outcomes of LIMA grafting in conventional coronary bypass grafting, of which 27 contained angiographic follow-up data. The completeness of angiographic follow-up was variable, but early graft patency (< or =1 month) in studied patients ranged between 94% and 99%. Late graft patency (up to 15 years) ranged from 51% to 98%. Five recent series of minimally invasive direct coronary artery bypass grafting that contained LIMA graft patency data show early graft patency rates between 91% and 99%.

CONCLUSIONS

Meaningful comparison of LIMA graft patency between arrested heart, conventional coronary artery bypass grafting, and minimally invasive direct coronary artery bypass grafting is difficult; however, early graft patency by both techniques can confidently be stated as being 90% or greater.

Computer-assisted telemanipulation: an enabling technology for endoscopic coronary artery bypass

BACKGROUND

The ultimate objective of minimally invasive coronary artery bypass grafting is to perform the anastomosis totally endoscopically. In this feasibility study, we examined the potential of performing coronary artery bypass grafting with the use of computer-assisted telemanipulation technology.

METHODS

Intuitive Telemanipulation Technology (Intuitive Surgical, Mountain View, CA) was used to perform an arterial graft to left anterior descending coronary artery anastomosis in an ex vivo on-bench swine heart model. The degree of difficulty in performing the anastomosis, intraoperative events, duration of the anastomosis, and its quality were determined.

RESULTS

Anastomosis was performed with relative facility, in a range of 10.7 to 17.4 minutes (mean +/- standard deviation, 14.6 +/- 2.6 minutes). All anastomoses were patent and of good quality except one, which had 30% narrowing of its heel.

CONCLUSIONS

We conclude that Intuitive Telemanipulation Technology may in the future permit the performance of quality totally endoscopic coronary artery anastomosis with facility and acceptable time.

Postoperative pneumonia

Thoracic surgical patients are susceptible to pneumonia because of impaired systemic and lung host defenses. The incidence of pneumonia is higher with more extensive lung resections. Current prophylactic antibiotic therapy is based primarily on general surgical experience with emphasis on wound infection, not pneumonia. With expansion of indications for lung resection to include higher risk patients, there is a need to render antibiotic prophylaxis more specific to bacteria causative of pneumonia.

Efficacy of administering an endothelin-receptor antagonist (SB209670) in ameliorating ischemia-reperfusion injury in lung allografts

The purpose of this study was to determine whether treatment with an endothelin-1 (ET-1)-receptor antagonist could prevent ET-1-mediated ischemia-reperfusion injury and early allograft dysfunction. Eleven dogs were subjected to left lung allotransplantation. Donor lungs were preserved with modified Eurocollins solution and stored at 4 degrees C for 18 to 20 h. Animals received an intravenous infusion of either the ET-receptor antagonist SB209670 (n = 6) (15 microg/kg/min) or saline (control, n = 5), in a blinded fashion. The infusion started 30 min before transplantation and continued for up to 6 h after transplantation. Hemodynamic measurements, blood gas tensions, and plasma samples were obtained with animals functioning solely on the transplanted lung. Open-lung biopsies were obtained for wet-to-dry-weight ratios and histologic and immunohistochemical analyses. Survival at 6 h after transplantation was 40% in the control group and 100% in the treatment group. Pulmonary vascular resistance and lung tissue wet-to-dry-weight ratio were significantly lower in treated animals at 3 and 6 h after transplantation. Histology of the transplanted lungs revealed more intense airway and interstitial inflammatory infiltration and edema in the control group. Arterial and venous plasma ET-1 concentrations increased after transplantation; however, they were significantly higher in the treatment group. Immunohistochemical analysis revealed more intense ET-1 immunostaining in the airways and parenchyma of the treatment group. We conclude that treatment of lung allografts with the mixed endothelin A/endothelin B (ETA/ETB) receptor antagonist SB209670 can ameliorate ischemia-reperfusion injury, resulting in improved graft function and survival after lung transplantation.

Immunohistochemical localization of endothelin-1 and endothelin-converting enzyme-1 in rat lung allografts

Chronic rejection is one of the principal factors that lead to development of obliterative bronchiolitis, which is the cause of death for 50% of lung allograft recipients. To more fully comprehend the pathogenesis of chronic rejection, we investigated the expression of endothelin-1 (ET-1) and endothelin-converting enzyme-1 (ECE-1) in inadequately immuno-suppressed rat lung allografts (n = 15) at monthly intervals after transplantation and compared these findings with those in normal rat lung (n = 5), using immunohistochemistry. Throughout the posttransplantation period, inflammatory cells expressed weak to moderate immunoexpression for both peptides. Constant weak to moderate immunoexpression for both peptides was also seen in the alveolar epithelium and neovascularized endothelium. Early after transplantation the vascular endothelium demonstrated strong immunostaining compared with control sections. This immunostaining, however, was reduced to control levels at later stages of rejection. As rejection progressed, staining in the airway epithelium diminished to weak levels as compared with that in controls. These findings suggest a causal role for ET-1 and ECE-1 in the inflammatory and proliferative damage associated with chronic rejection after lung transplantation.

A novel charcoal-induced model of obliterative bronchiolitis-like lesions: implications of chronic nonspecific airway inflammation in the development of posttransplantation obliterative bronchiolitis

OBJECTIVES

In this study, we describe the development of a nonallogeneic animal model of obliterative bronchiolitis-like lesions. Furthermore, we examined whether chronic rejection alone can lead to the development of obliterative bronchiolitis or whether additional nonspecific airway inflammation is required.

METHODS

Part I: Rats were intratracheally injected with 0.2 ml of activated charcoal or sorbitol solution (carrier for charcoal control). Animals were put to death beginning at 2 weeks up to 20 weeks. Part II: Animals were divided into three groups: group I, underimmunosuppressed Brown Norway to Lewis lung allografts; group II, charcoal-treated underimmunosuppressed allografts; and group III, charcoal-treated rats. Animals were put to death at 3 months after transplantation.

RESULTS

Part I: In charcoal-laden bronchioles, subacute nonspecific airway inflammation was detected at 2 weeks. Slow, subclinical fibroproliferation ensued during the following weeks. Obliterative bronchiolitis-like lesions were observed in 80% of charcoal-treated animals at 12 weeks. Part II: Allografts developed extensive vascular lesions consistent with acute and chronic vascular rejection. Obliterative bronchiolitis-like lesions were scarcely detected. Charcoal-treated allografts demonstrated evidence of diffuse and severe obliterative bronchiolitis-like lesions.

CONCLUSIONS

Transtracheal injection of activated charcoal into native lungs results in slowly progressive airway injury and inflammation leading to obliterative airway lesions. Inadequate immunosuppression primarily results in chronic vascular rejection but not obliterative bronchiolitis. Underimmunosuppressed allografts subjected to nonspecific airway inflammation develop obliterative airway lesions that are more prominent than in native lungs. This suggests that a cofactor to chronic rejection is likely necessary for the development of lung transplant obliterative bronchiolitis.

Evolving strategies in minimally invasive coronary artery surgery

It is estimated that approximately 25% of cardiac surgery will be performed through minimal access by the year 2000. While original efforts focused on performing minimally invasive cardiac surgery totally thoracoscopic, and with cardiopulmonary bypass, more recent realistic approaches rely on small targeted incisions and video assisted techniques on the beating heart. Current instrumentations which provide segmental stabilization of the heart eliminate the need for cardioplegic arrest and cardiopulmonary bypass. While early results are encouraging, intermediate and long term clinical outcome and graft patency remain to be determined.

Superior vena cava obstruction secondary to mediastinal lymphadenopathy in a patient with cystic fibrosis

Superior vena cava (SVC) obstruction most often is a complication of malignant tumors such as lung cancer or lymphoma. The common use of long-term indwelling central venous catheters also has added to the prevalence of SVC obstruction. This report describes the first case of SVC obstruction in a patient with cystic fibrosis due to extrinsic compression from benign reactive mediastinal lymphadenopathy. Although in these circumstances intravascular thrombosis should be ruled out, extrinsic compression from mediastinal lymphadenopathy should be considered.

Catheter-assisted totally thoracoscopic coronary artery bypass grafting: a feasibility study

BACKGROUND

The purpose of this study is to examine the feasibility of performing totally thoracoscopic internal mammary-to-coronary artery bypass grafting with the assistance of radiologically guided catheter intervention.

METHODS

Fourteen dogs were subjected to mobilization of the internal mammary artery and anastomosis of it to the left anterior descending coronary artery over an angiographic catheter inserted into the internal mammary artery under fluoroscopy. The anastomosis was completed over the catheter using sutures and the application of fibrin glue. Eight animals underwent the anastomosis after their sacrifice. The other 6 animals were put on closed chest cardiopulmonary bypass and had their anastomosis done after intraaortic balloon occlusion and cardioplegic arrest of the heart. All animals had an angiographic and pathologic examination at the completion of the anastomosis.

RESULTS

Anastomosis was completed in all dogs. Three anastomoses leaked and two were noted to be stenosed at completion of the anastomosis. One leak was sealed by application of fibrin glue. Both stenotic anastomoses were caused by suturing of the back wall when a short angiographic catheter could not be positioned across the anastomosis.

CONCLUSIONS

Minimally invasive totally thoracoscopic mammary-to-coronary artery bypass grafting with catheter assistance is feasible. Technical improvement and appropriate instrumentation are required to minimize anastomotic failure.

Immunohistochemical characterization of inflammatory and proliferative events during chronic rejection in rat lung allografts

BACKGROUND

Chronic rejection is assumed to be the principle cause of airway injury leading to obliterative bronchiolitis (OB) after lung transplantation (Tx). To better understand the contribution of chronic rejection in the development of OB in allografted lungs, we examined the histopathological changes and cytokine expression in inadequately immunosuppressed rat lung allografts.

METHODS

Three groups of rats were studied: group I, control nontransplanted Lewis (Lew) rats (n=5); group II, syngeneic Lew-to-Lew isografts (n=25); and group III, Brown Norway-to-Lew allografts (n=25). Groups II and III received two single doses of cyclosporine on postoperative days 2-3. Transplanted animals were killed (n=5) at monthly intervals from 2 months to 6 months after Tx. Resected lungs were stained with hematoxylin and eosin, Masson's trichrome, and Van Gieson's elastin, and immunostained with antisera to interleukin (IL)-1beta, IL-8, and basic fibroblast growth factor (bFGF). The intensity of immunostaining was graded from 0 to 4 (0=no staining, 4=strong staining).

RESULTS

In groups I and II, normal airways and vessels were observed. Minimal intensity and distribution of immunostaining for all markers were detected in groups I and II. Group III allografts demonstrated acute grade II-III vascular rejection with mild bronchiolar injury and inflammation at 2 months after Tx. At 6 months after Tx, all allografts demonstrated severe and diffuse chronic vascular rejection. Late airway changes consistent with OB were detected in four of five allografts, however, these lesions were expressed infrequently. Immunohistochemical findings revealed moderate to strong expression for IL-8 and bFGF over the airway epithelium, acute and chronic inflammatory cells, and fibroblasts in allografts at 2 months after Tx. Despite focal development of OB at 6 months, intensity and distribution of immunostaining significantly decreased for all three cytokine markers.

CONCLUSIONS

Inadequate immunosuppression of rat lung allografts leads primarily to chronic vascular rejection but fails to induce severe and diffuse development of OB. In this animal model, cytokines IL-1beta, IL-8, and bFGF are likely to play an important role in the early inflammatory phase but not during the late proliferative events of chronic rejection.

Immunohistochemical localization of nitric oxide synthase and the oxidant peroxynitrite in lung transplant recipients with obliterative bronchiolitis

BACKGROUND

Obliterative bronchiolitis (OB) is a disease affecting a large percentage of lung and heart-lung transplant recipients. Histologically, the disease is characterized by inflammation, cellular proliferation, and obliteration of terminal airways.

METHODS

We investigated the production of inducible and constitutive nitric oxide synthases and peroxynitrite by immunohistochemistry in the lungs of control subjects (n=14) compared with those of transplant recipients with OB (n=8).

RESULTS

Strong immunoreactivity for inducible nitric oxide synthase and nitrotyrosine, a marker of protein nitration by peroxynitrite, was seen in inflammatory cells, airway epithelium, and vascular endothelium of patients with OB, compared with little immunoreactivity in control lungs. Immunoreactivity for constitutive nitric oxide synthase was abundant in the airway epithelium and vascular endothelium of control lungs, however, it was decreased in airway epithelial cells and arterial endothelial cells of patients with OB.

CONCLUSIONS

We conclude that increased formation of the potent oxidant peroxynitrite and decreased production of endothelial nitric oxide may contribute to the functional and morphological abnormalities of OB.

A survey on minimally invasive coronary artery bypass grafting

BACKGROUND

There is increasing interest in performing minimally invasive coronary artery bypass grafting. To evaluate the current level of acceptance and utility of this procedure a survey of 162 cardiothoracic surgeons was conducted.

RESULTS

Currently only 16% of surveyed surgeons performed more than 10 minimally invasive coronary artery bypass grafting procedures. Most were less than 55 years old and in private practice. The majority predicted that it will be indicated in less than 25% of coronary artery bypass grafting cases and considered minimally invasive coronary artery bypass grafting a modification of existing techniques rather than investigational. Most believed exposure and stabilization of the coronary arteries on the beating heart to be the most challenging part and expressed concern with quality of the anastomosis.

CONCLUSIONS

We conclude that minimally invasive coronary artery bypass grafting is rapidly gaining acceptance in younger surgeons as techniques are improved. Despite concerns with adequacy of anastomosis the procedure is not considered investigational and follow-up is not rigorous.

Video-assisted thoracic surgery: has technology found its place?

BACKGROUND

Since the introduction of minimally invasive surgical techniques in thoracic surgery in 1990, video-assisted thoracic surgery (VATS) has become the approach for many thoracic operations. The role of VATS has slowly evolved but has not been clearly defined. To better understand the role of VATS, we undertook a survey of practicing thoracic surgeons.

METHODS

A questionnaire was sent to members of the General Thoracic Surgery Club asking the role of VATS in their practice and their opinions regarding appropriate applications, advantages, and limitations of the approach.

RESULTS

Two hundred of the 229 members (87.3%) responded to the questionnaire. In this largely academic (66.3%) group of thoracic surgeons, 72% of whom had more than 10 years experience in general thoracic surgery, VATS was the preferred approach (> 50% response) for the management of pleural disease, lung biopsy, recurrent pneumothorax, and sympathectomy. A majority of respondents thought that VATS was an acceptable approach for the diagnosis of the indeterminate pulmonary nodule and of anterior and posterior mediastinal masses, and for the management of early empyema, clotted hemothoraces, secondary pneumothorax, limited lung cancer treatment, and benign esophageal disease. Video-assisted thoracic surgery was thought to be unacceptable or investigational by a majority for thymectomy, lobectomy, and lung volume reduction operations. Video-assisted thoracic surgery still represents only a small portion of the thoracic procedures performed, but there is a gradual increase in its rate of use, although 38.1% expressed concern regarding overuse. The main limitation was thought to be in the management of oncologic disease.

CONCLUSIONS

It appears that VATS is a valuable addition to the practice of thoracic surgery, but significant limitations exist. Although there appear to be many specific indications defined, there is still a significant evolutionary component.

Safe and effective method of stabilization for coronary artery bypass grafting on the beating heart

BACKGROUND

There is an emerging interest in performing coronary artery bypass grafting on the beating heart. This study examines the efficacy and safety of two types of coronary artery stabilizers developed to perform coronary artery bypass grafting on the beating heart.

METHODS

Four dogs underwent left internal mammary artery to left anterior descending artery anastomosis using a retractor-fixed stabilizer. Measurements of hemodynamic indices and range of motion of the targeted arteriotomy were done before and after application of the stabilizers. Patency of the anastomosis was evaluated by angiography. To clinically validate the safety of this stabilizer, we collected data on 150 patients from centers that had access to the retractor-fixed stabilizer.

RESULTS

All animals survived the procedure with no ischemic changes or hemodynamic alterations. A significant reduction in range of motion (mm) of the left anterior descending coronary artery was achieved after application of the stabilizers. Angiographic studies showed good anastomotic patency. Histologic examination showed no myocardial injury. Patient data revealed successful completion of the anastomosis, with conversion to sternotomy or cardiopulmonary bypass in 1 patient each. Intraoperative and postoperative myocardial infarctions occurred in 1 patient each, with one in-hospital death.

CONCLUSIONS

Significant stabilization of targeted coronary arteries allowing the performance of safe and reliable anastomosis on a beating heart can be achieved using the stabilizer.

Prolonged ischemia is associated with more pronounced rejection in the lung allograft

BACKGROUND

Previously it was found that ischemia-reperfusion injury in a left lung autotransplantation model could be a minor inducer of major histocompatibility complex (MHC) class II antigen expression. Thus, we hypothesized that prolonged ischemic times may result in increased expression of MHC class II antigens and predispose the lungs to the development of acute rejection early after transplantation.

METHODS

Twenty conditioned dogs underwent single left lung allotransplantation. Donor lungs were subjected to 4 or 24 hours (n = 10 each) of cold ischemia. Open lung biopsies, bronchoalveolar lavage fluid, and blood samples were taken preoperatively and at various intervals up to 1 week after transplantation. Lung biopsy specimens were examined histologically for MHC class II expression and graded for acute rejection. Bronchoalveolar lavage fluid and plasma were analyzed for cytokines interleukin-2 and interferon-gamma.

RESULTS

In the 4-hour ischemia group, there was mild diffuse staining of the bronchial epithelium and cellular infiltrate for MHC class II antigens after 1 week with subsequent grade 1-2 rejection. In the 24-hour ischemia group, MHC expression after 1 week revealed strong diffuse staining of bronchial epithelium, vascular endothelium, and cellular infiltrates with a significantly higher grade of rejection. Interleukin-2 and interferon-gamma significantly increased in BAL fluid early after transplantation in both groups.

CONCLUSIONS

Ischemic injury may predispose the lung allograft to the development of acute rejection, in part, through the upregulation of MHC class II antigen expression and the local release of cytokines.

Altered nonspecific lymphocyte cytotoxicity in bronchoalveolar lavage of lung transplant recipients: can it be useful in monitoring rejection or infection?

A reliable method for determining the adequacy of immunosuppression of the lung allograft and the absence of rejection or infection does not exist. The purpose of this study is to evaluate the potential role of bronchoalveolar lavage (BAL) in monitoring the adequacy of immunosuppression of lung allografts and in identifying the possible presence of acute rejection (AR) or infection. Thirty-one consecutive lung transplant recipients were subjected to bronchoscopy, transbronchial biopsy, and BAL either as routine surveillance or for decline in lung function (n=68 episodes: 27 normal, 17 infections, six grade IAR, 10 grade II-III AR, and eight obliterative bronchiolitis). Diagnosis was always confirmed histologically and by microbiological workup. Harvested cells underwent phenotypic analysis, and T lymphocytes were subjected to nonspecific lectin-dependent cell-mediated cytotoxicity (LDCMC) and natural killer cytotoxic assays. BAL from normal grafts predominantly contained macrophages (72.8+/-4.4%), with lower neutrophil (13.9+/-4.1%) and lymphocyte (13.2+/-2.2%) populations. Grade II-III AR and infection were associated with an increase in the percentage of neutrophils (43.3+/-8.3% and 33.2+/-3.6%, respectively, P=0.02). BAL of normal allografts contained T cells with low LDCMC (7.4+/-4.5%) and natural killer cytotoxicity (6.3+/-3.4%), whereas grade II-III AR was associated with a significant elevation in LDCMC (32.5+/-11.6%, P=0.019). Pulmonary infection, regardless of its type, was associated with significant elevation in BAL natural killer cytotoxicity (23.9+/-4.9%, P=0.033). Patients with obliterative bronchiolitis, on the other hand, had a mild elevation in the percentage of neutrophils and lymphocytes in BAL, which did not reach statistical significance. However, BAL T-cell LDCMC was significantly elevated (37.6+/-13.7%, P=0.019) compared with normal and infected allografts. We conclude that phenotypic and nonspecific cytotoxic T-cell analysis of BAL, when complimented with microbiological studies, may be useful in surveillance of lung transplant recipients and in determining whether allografts are likely to be quiescent, or possibly affected by acute/chronic rejection or infection, necessitating further definitive action.

Amelioration of pulmonary allograft injury by administering a second rinse solution

OBJECTIVE

The use of rinse solutions before reperfusing liver allografts has been shown to reduce cell death in rats. Carolina rinse solution (an extracellular solution that contains antioxidants, vasodilators, and other substrates that help prevent ischemia-reperfusion injury) has also been shown to improve liver function clinically in liver transplant recipients. This pilot study evaluates the value of a second pulmonary artery flush before reperfusion of a lung graft.

METHODS

Six groups of Sprague-Dawley rats (n = 6 each) were subjected to the following: Group 1 lungs were preserved with modified Euro-Collins solution followed by 24 hours of cold ischemia. Group 2 lungs were treated the same as group 1 but reperfused with blood. Group 3 lungs were preserved in Carolina rinse solution followed by 24 hours of cold ischemia. Group 4 lungs were treated the same as group 3 lungs and then reperfused with blood. Lungs in groups 5 and 6 were preserved with Euro-Collins solution, stored cold for 24 hours, and then rinsed with Euro-Collins or Carolina rinse solution, respectively, before reperfusion with blood. Lungs were subsequently stained with trypan blue solution for 5 minutes. Lung blocks were fixed and embedded in water-soluble methacrylate. Trypan blue--stained nuclei in nonviable endothelial cells and alveolar pneumocytes were counted in 10 different fields.

RESULTS

Groups 1 and 3, preserved with Euro-Collins and Carolina rinse solutions for 24 hours but not reperfused with blood, had significantly more viable endothelial cells (groups 1 and 3 vs group 2, p < 0.0001; group 3 vs group 4, p < 0.02) and pneumocytes (group 1 vs groups 2 and 4, group 3 versus group 2, p < 0.0001; group 3 vs group 4; p < 0.035) than groups 2 and 4, which were subsequently reperfused with blood. Groups 5 and 6, which received a second rinse, also had significantly more viable endothelial cells (p < 0.0005) and pneumocytes (p < 0.0001) than control groups, which were not rinsed before reperfusion.

CONCLUSIONS

We conclude that damage to pulmonary allografts resulting from prolonged ischemia is accentuated by reperfusion with blood. We also conclude that preservation with a single flush of Euro-Collins or Carolina rinse solution does not offer adequate protection, whereas a second rinse before reperfusion significantly decreases the number of damaged cells within the allograft.

Bronchoscopy in the intensive care unit

With the prevalence of bronchopulmonary disease in the intensive care unit, bronchoscopy has become an essential tool for the management of patients. This article describes the variety of situations in which bronchoscopy can be of assistance in establishing diagnosis, managing the difficult airway, and supporting the patient's suffering of trauma, hemoptysis, atelectasis, and pneumonia.

Expression of nitric oxide synthase in the human nasal mucosa

The nasal mucosa plays an important role in defense of the lung against harmful agents. It has been suggested that this is partly mediated by the production of nitric oxide (NO). We have investigated the localization of the messenger ribonucleic acids (MRNAs) for human endothelial NO synthase (Type III NOS) and inducible NO synthase (Type II NOS) and the immunoreactivities of these enzymes in human nasal mucosa by immunohistochemistry, in situ hybridization, and reduced nicotinamide adenine diphosphate (NADPH) diaphorase histochemistry. Inferior nasal turbinates were obtained from 27 patients at the time of surgery for local disease. Strong immunostaining for Type III NOS was localized to vascular endothelium, surface epithelium, and submucosal glands in all subjects. Moderate immunostaining for Type II NOS was seen in surface epithelium; glandular, inflammatory, and vascular endothelial cells; and smooth-muscle cells in the specimens from patients with chronic rhinitis only. In situ hybridization showed expression of the mRNA for Type III NOS in similar sites to those shown by immunohistochemistry, whereas the mRNA for Type II NOS was predominantly localized to inflammatory cells. The sites of NOS expression were further confirmed by NADPH histochemical staining. These findings demonstrate the cellular expression of NOS in the human nasal mucosa and suggest a possible role for Types II and III NO synthase in the regulation of blood flow, nasal secretion, and ciliary movement in health and disease.

Cytokine interleukin-2, tumor necrosis factor-alpha, and interferon-gamma release after ischemia/reperfusion injury in a novel lung autograft animal model

Previously, we have reported an increase in the cytokines interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) early after left lung allotransplantation in dogs. The purpose of this study was to develop a novel model of canine lung autotransplantation and to observe whether ischemia/reperfusion injury alone (in the absence of an allogenic stimulus) would result in this cytokine release as seen in the allograft. Thus, using this model, early changes in cellular and cytokine composition in the lung autograft were monitored through the use of bronchoalveolar lavage (BAL) and plasma. The effects of ischemia/reperfusion injury on lung histology and major histocompatibility class II (MHC II) antigen expression were also observed. Ten mongrel dogs were subjected to left lung autotransplantation. Lungs were stored cold for 4 h, with a warm ischemic time of 1 h. BAL, blood, and biopsy specimens were taken preoperatively and 1 h, 4 h, 24 h, and 1 wk postoperatively. The mean BAL IL-2 levels significantly rose from a preoperative value of 150 +/- 19 pg/ml to 246 +/- 67 pg/ml 4 h after transplantation (p < 0.05), decreasing to preoperative levels after 24 h (128 +/- 54 pg/ml). Plasma levels of IL-2 did not change from preoperative values. In contrast to IL-2, TNF-alpha and IFN-gamma did not change in either BAL or plasma of the autograft.(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in bronchoalveolar lavage and plasma endothelin-1 levels early after lung transplantation

A temporary increase in pulmonary vascular resistance is observed during the first 24 hr following lung allotransplantation. We hypothesized that such early vascular changes are secondary to endothelial injury by ischemia-reperfusion, and that this may be mediated by an increased pulmonary endothelin-1 production/release. To test this hypothesis, radioimmunoassay was used to analyze endothelin-1 levels in bronchoalveolar lavage and plasma taken before surgery and at 1 hr, 4 hr, 24 hr, and 1 week after transplantation. The study was carried out on 2 groups of mongrel dogs. One group was subjected to left single-lung allotransplantation and the other to autotransplantation. Endothelin-1 levels in the bronchoalveolar lavage samples from the lung allografts were significantly increased at 1 (0.70 +/- 0.18 pg/ml) and 4 (1.84 +/- 0.65 pg/ml) hr after transplantation compared with the preoperative value (0.14 +/- 0.05 pg/ml), and declined at 24 (0.85 +/- 0.84 pg/ml) hr after transplantation. Similarly, plasma endothelin-1 levels in the allografts were significantly increased at 1 (2.0 +/- 0.80 pg/ml) and 4 (2.0 +/- 0.71 pg/ml) hr after transplant when compared with preoperative levels (0.54 +/- 0.09 pg/ml). Plasma endothelin-1 levels, however, remained significantly high after 24 hr (1.4 +/- 0.4 pg/ml; P < 0.007) and decreased after 1 week after transplant (0.89 +/- 0.32 pg/ml). On the other hand, endothelin-1 levels in bronchoalveolar lavage from the autograft group remained relatively unchanged; however, plasma levels showed a significant increase at 4 hr (6.6 +/- 1.8 pg/ml) after transplantation compared with preoperative levels (2.8 +/- 0.38 pg/ml). Elevation of endothelin-1 levels early after lung transplantation may play an important role in early high pulmonary vascular resistance and temporary graft dysfunction.

Postthoracotomy pulmonary function: a comparison of epidural versus intravenous meperidine infusions

It has remained unclear whether epidural opioid analgesia permits better recovery of postthoracotomy pulmonary function than an optimal method of systemic opioid administration. Lumbar epidural meperidine infusions were compared with intravenous patient-controlled analgesic (PCA) meperidine infusions in a prospective randomized unblinded study for 72 hours postthoracotomy. Before induction of general anesthesia, patients received a bolus of meperidine, 1 mg/kg, and an infusion of meperidine, 0.33 mg/kg/hr, was started via either a lumbar epidural or intravenous catheter. Postoperatively, the meperidine infusion rates were titrated as needed for analgesia. In addition, the intravenous group received meperidine, 10 mg per dose, as required, from a patient-controlled analgesia pump. No other opioid was administered during the study period. Patients were studied for recovery of spirometric tests of pulmonary function, visual analog pain scores, sedation, arterial blood gases, meperidine dose requirements, radiographic pulmonary complications, and neurologic signs and symptoms. A subgroup of 10 patients (5 from each group) had venous blood samples drawn every 24 hours for 96 hours and assayed for serum meperidine and normeperidine concentrations. Epidural meperidine analgesia was associated with improved postthoracotomy pulmonary function, better analgesia scores, and lower meperidine dose requirements than intravenous PCA meperidine. There were no differences between the epidural versus intravenous PCA subgroups with respect to serum meperidine or normeperidine levels. Normeperidine levels greater than 300 ng/mL were associated with an increased incidence of shakiness and/or tremors. Meperidine provides satisfactory postthoracotomy analgesia via a lumbar epidural infusion. This analgesia is associated with improved recovery of postoperative pulmonary function when compared with an intravenous PCA meperidine infusion.

Improved outcome of rat lung transplantation with modification of the nonsuture external cuff technique

BACKGROUND

The development of lung transplantation in inbred rats has simplified immunologic studies concerning lung allografts. Unfortunately, up to now, such models have been limited by the high level of surgical expertise required.

METHODS

In this study 92 rats underwent left lung transplantation with a simplified cuff technique. The feasibility and reliability of this technique was determined by examining graft patency through the use of gross and histologic examination, angiography, and bronchography.

RESULTS

On gross examination, grafts looked well perfused and ventilated. Histologic examination showed little evidence of foreign body reaction against the Teflon cuff devices, and angiography showed no abnormalities; however, bronchography did show signs of airway stricture at the site of the anastomosis.

CONCLUSION

We conclude that the nonsuture external cuff technique with Teflon devices represents a reliable, safe, and fast method for performing orthotopic left lung transplantation in the rat.

Heart-lung and bilateral lung transplantation in children with cystic fibrosis

Bilateral lung and heart-lung transplantation are indicated for cystic fibrosis children with end-stage lung disease. This article discusses the current criteria for inclusion-exclusion, surgical techniques, and results.

Airway mucus and epithelial function in a canine model of single lung autotransplantation

Impaired mucociliary function following lung transplantation has been reported in several human and animal studies. This could be a result of altered ciliary function or mucus properties or both. We assessed airway epithelial function by means of transepithelial potential difference (PD) measurements and physical analysis of mucus. Six mongrel dogs underwent single lung autologous transplantation. Measurements were performed preoperatively and 1, 2, 4, and 10 months postoperatively. At 1 and 2 months postoperatively, there was a significant fall in PD for the transplanted, left mainstem bronchus only (-13.5 +/- 1.7 mV at 1 month and -14.6 +/- 1.7 mV at 2 months postoperatively vs -18.6 +/- 2.3 mV preoperatively, baseline; p < 0.001 for both). The PD values in the small airways, right mainstem bronchus, and the trachea remained unchanged. At 2 months postoperation, the mucus collection rate on the left side was increased (p = 0.03), while the mucus viscoelasticity was decreased (p = 0.04). By 4 months postoperation, all epithelial parameters had returned to baseline, and there was no difference in radioaerosol clearance between the two lungs. The PD decrease and alterations in secretion rate and viscoelasticity reflect disturbed epithelial functional integrity at the site of anastomosis still present at 2 months postoperation. Recovery of bronchial epithelial function and clearance in canine studies of lung autotransplantation after healing of the anastomosis area suggest that persistent impairment of lung clearance observed in some long-term human lung transplantation survivors may be due to other mechanisms such as impaired healing or epithelial function or both, during immunosuppressive therapy. Mucociliary function in the anastomosis area is compromised until complete healing ensues; we speculate that chest physiotherapy may aid in overcoming this obstacle.

Coronary artery revascularization followed by single-lung transplantation in a patient with combined end-stage idiopathic pulmonary fibrosis and left main coronary artery stenosis

Single-lung transplantation has been used successfully in patients who have idiopathic pulmonary fibrosis; however, coronary artery disease is often considered a contraindication for lung transplantation in such patients. We report the case of a 53-year-old man with idiopathic pulmonary fibrosis in whom left main coronary artery stenosis was found incidentally during pretransplant evaluation. The patient was treated successfully with elective coronary artery bypass grafting, followed by left single-lung transplantation 35 days later.

The early release of interleukin-2, tumor necrosis factor-alpha and interferon-gamma after ischemia reperfusion injury in the lung allograft

A period of cold and warm ischemia is obligatory when performing lung transplantation. Subtle ischemia-reperfusion injury induced in the course of transplantation can pass undetected or cause a short phase of reversible lung dysfunction. We hypothesized that ischemia-reperfusion injury may result in the local release of cytokines that have the capability to mediate acute lung injury early following transplantation. To test this hypothesis, 10 mongrel dogs were subjected to left lung allotransplantation. As performed in the clinical setting, donor lungs were preserved with Eurocollins solution and stored at 4 degrees C for 4 hr, which was followed by 1 hr of warm ischemia. Recipients received standard immunosuppression of cyclosporine, azathioprine, and low dose steroids. Bronchoalveolar lavage (BAL) and open lung biopsies were performed before operation and at approximately 1 hr, 4 hr, 24 hr, and 1 week after transplantation. A significant increase in BAL IL-2 levels was observed 4 hr after surgery (0 hr: 349 +/- 138 pg/ml; 4 hr: 757 +/- 284 pg/ml) (mean +/- SEM) (P < 0.05) which subsequently decreased 24 hr (320 +/- 168 pg/ml) after transplantation. BAL TNF-alpha levels were significantly increased 1 hr after transplantation (P < 0.05) (0 hr: 3.4 +/- 0.65 pg/ml; 1 hr: 13.3 +/- 8.0 pg/ml) returning to baseline after 24 hr (5.8 +/- 2.8 pg/ml). BAL IFN-gamma levels also significantly increased 1 and 4 hr after transplantation (0 hr: 7.2 +/- 2.1 pg/ml; 1 hr: 68.2 +/- 49.2 pg/ml; 4 hr: 301 +/- 131 pg/ml) (P < 0.05). This decreased back to baseline after 24 hr and 1 week (5.2 +/- 1.2 pg/ml and 9.7 +/- 7.9 pg/ml, respectively). There were no changes detected in plasma levels of cytokines. Histology showed evidence of grade 1-2 rejection after 1 week. We conclude that subjection of a lung allograft to standard periods of cold-warm ischemia will result in a temporary early elevation of IL-2, TNF-alpha, and IFN-gamma detectable only in the bronchoalveolar compartment. Such local increase in cytokines in the lung allograft may play an important role in the development of early allograft dysfunction.

Slow-rate, high-pressure ventilation: a method of management of difficult transplant recipients during sequential double lung transplantation for cystic fibrosis

Single and double lung ventilation can be extremely difficult in patients with cystic fibrosis who require sequential double lung transplantation. This article reports the successful use of slow-rate, high-pressure ventilation in the management of two ventilator-dependent patients who would otherwise have needed to be supported by cardiopulmonary bypass.

Video-assisted minithoracotomy versus muscle-sparing thoracotomy for performing lobectomy

We prospectively analyzed the outcome of lobectomy in a cohort of 67 patients. Operative time, postoperative pain, pulmonary function, and early outcome were compared between the patients undergoing video-assisted techniques (n = 44) and those undergoing standard muscle-sparing procedures (n = 23). Pain was quantified daily throughout the first week using the visual analog scale. The forced expiratory volume in 1 second and the forced vital capacity were measured at days 2, 4, and 8 postoperatively. The operative time was significantly longer (p < 0.02) and the postoperative pain was significantly less (p < 0.006) in the group undergoing video-assisted procedures. Pain-related morbidity, the mean duration of air leaks, the duration of chest tube placement, and the hospital stay were all less in the video-assisted group, but the differences did not reach statistical significance. However, the impairment in pulmonary function and the overall morbidity were identical for the two groups. Based on our findings, we conclude that video-assisted minithoracotomy is a safe and reliable approach for performing lobectomies, and that the decreased postoperative pain associated with this minimally invasive approach does not result in preserved pulmonary function and significantly reduced morbidity when compared with a muscle-sparing thoracotomy.