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Biomedical subjects

V R Kshettry

Publications and source records attributed to V R Kshettry.

At least 19 recordsLinked to original sources
PubMed2001

OPCAB surgery: a critical review of two different categories of pre-operative ejection fraction.

OBJECTIVE: Literature review found little information on off-pump coronary artery bypass (OPCAB) procedure in patients with poor left ventricular function and there was no information comparing the low EF and normal EF patients undergoing OPCAB procedure. METHODS: Between 1/1/1998 and 6/30/1999, 387patients had surgery performed utilizing the off-pump technique and 45 of these patients had pre-operative left ventricular function of equal to or less than 30% (LVEF < or =30). The two groups (LVEF < or =30 and LVEF>30) were compared using univariate analysis. Patients in LVEF < or =30 were older and more female gender. LVEF< 30 had more NYHA class IV patients (64 vs. 50%) and more symptoms related to depressed left ventricular function. The mean pre-operative left ventricular function was 25% in LVEF < or =30 and 56% in LVEF>30. Pre-operative predicted risk was 6.4+/-5.5% in LVEF < or =30 and 2.7+/-4.5% in LVEF>30 (P< 0.001). Most (> 95%) of the patients in both groups were elective status, and LVEF < or =30 patients had increased incidence of redo (11 vs. 6%, P=0.2). In LVEF>30, 84% of the patients had stable angina while only 69% in LVEF < or =30 (P=0.009). RESULTS: Intra-operatively no significant differences were measured in number of grafts per patient (2.7 vs. 2.8), amount of blood loss, peak CK-MB, skin-to-skin time, or OR time. Patients with LVEF < or =30 have more frequent utilization IABP during pre, intra and post-operative period. The statistical analysis yields no significance in post-operative major neurological deficit between these two groups; and are comparative to the nationally reported incidence of neurological deficit for on-pump patients. The operative mortality in the low EF group was 4.4 and 1.8% in LVEF>30 group (P=0.23). CONCLUSIONS: Given the clinical presentation of the low EF group, higher prediction risk, longer pre-operative stay, and length of ventilation (24 vs. 8 h P=0.12) a longer surgery to discharge stay (8 vs. 6 days, P=0.02) is anticipated. Short-term clinical outcomes for both groups of OPCAB patients encouraged us to continue to offer this approach to this broad base of patient population.

Aged↗
PubMed2000

Does multivessel, off-pump coronary artery bypass reduce postoperative morbidity?

BACKGROUND: Off-pump coronary artery bypass (OPCAB) is an emerging procedure. It is assumed that elimination of cardiopulmonary bypass for coronary artery bypass grafting has the potential for reducing postoperative morbidity. This review evaluates the safety and impact of multivessel OPCABG as compared to CABG. METHODS: A retrospective review of 744 patients undergoing multivessel coronary artery bypass between January 1, 1997, and March 31, 1999, was done. The total population was divided into two groups: group A (n = 609 cardiopulmonary bypass) and group B (n = 135 OPCAB). This consecutive study cohort was elective status, full sternotomy with three or more distal anastomoses performed at a single institution. RESULTS: The mean risk adjusted predicted mortality was 2.3% in group A and 2.7% in group B (p = NS), with the mean number of distal anastomosis being greater in group A (3.8 vs 3.5/patient, p < 0.001). Major postoperative complications were similar but were not statistically significant between groups. Postoperative blood loss and use of blood transfusions were the only significant variables (p < 0.001). CONCLUSIONS: Multivessel OPCABG can be safely performed in selected patients. Elimination of cardiopulmonary bypass did not significantly reduce postoperative morbidity. Prospective randomized trials and long-term follow-up are needed to better define patient selection and the role of OPCABG.

Aged↗
PubMed2000

Is low ejection fraction safe for off-pump coronary bypass operation?

BACKGROUND: Does the manipulation of the heart during off-pump coronary artery bypass (OPCAB) procedure further compromise the hemodynamic stability of a patient with depressed left ventricular function compared with the conventional coronary artery bypass (CCAB) approach? Does this manipulation induce a more dramatic hypoperfused state that may contribute to an increase in the incidence of related complications or mortality? This retrospective review of data attempted to answer the above concern. METHODS: Between January 1, 1998, and June 30, 1999, 177 patients with ejection fractions of 30% or less underwent full sternotomy coronary artery bypass grafting at our institution. Of these patients, 45 underwent OPCAB procedures and 132 patients underwent CCAB. Pre-, intra-, and postoperative variables as identified by The Society of Thoracic Surgeons National Cardiac Surgery Database were compared using univariate and logistical regression analysis. RESULTS: Despite recognized hemodynamic derangement during cardiac displacement, these groups of OPCAB patients appeared to tolerate the procedure well. Univariate analysis of cardiac enzyme leak and blood loss was statistically significant in the OPCAB patients. Utilizing regression analysis, cardiopulmonary bypass was the only predictor for all postoperative complications. CONCLUSIONS: Multivessel coronary artery bypass utilizing the OPCAB approach in patients with depressed left ventricular function of equal to or less than 30% is appropriate and applicable. Analysis of CCAB and OPCAB variables was nonsignificant except for operative and postoperative blood loss and peak cardiac enzyme leak. Attention to intraoperative detail and hemodynamic management could be credited for the success with OPCAB.

Cardiopulmonary Bypass↗
PubMed2000

Safety and efficacy of off-pump coronary artery bypass grafting.

BACKGROUND: We evaluated the application of the off-pump coronary artery bypass (OPCAB) procedure relative to safety and efficiency as measured by operative mortality postoperative complications and longitudinal outcome. METHODS: Three hundred and fifty OPCAB patients were compared to 3,171 on-pump or conventional coronary artery bypass (CCAB) patients between January 1, 1997 and December 31, 1998. The groups were divided into three preoperative predicted risk categories: low-risk (0 to 2.59%), medium-risk (2.6 to 9.9%), and high-risk (> or =10%). Society of Thoracic Surgeons National Cardiac Surgery Database definitions and predicted risk group models were utilized to compare all preoperative, intraoperative, and postoperative variables using univariate analysis. RESULTS: Overall comparison of the immediate outcome of CCAB and OPCAB shows little statistical significance in the variables analyzed. The operative mortality was 3.4% in both groups. When the immediate outcome was compared between groups (CCAB vs OPCAB), as well as individual risk groups (low, medium, and high), similar patterns of operative variables and postoperative complications were observed. The operative mortality in the low-risk group was 1.1% for CCAB and 1.4% for OPCAB; 7% for CCAB and 6% for OPCAB in the medium-risk group; and in the high-risk group 28.5% for CCAB compared to 7.7% for OPCAB group (p = 0.008). Short-term follow-up shows a trend of increased recurring angina and reinterventional procedures in the OPCAB patients. CONCLUSIONS: Safety for OPCAB is assessed through retrospective data review. Longitudinal follow-up for survival, reintervention, and quality of postoperative document efficacy and patency rates, compared to on-pump procedures, is mandatory. This study documented the immediate safety of the OPCAB procedure. Preliminary findings at 1-year follow-up is an important finding in this study, but it is not conclusive at this time. Long-term longitudinal follow-up is required to assess the future effectiveness of OPCAB.

Coronary Artery Bypass↗
PubMed1999

Comparison between port-access and less invasive valve surgery.

BACKGROUND: Valvular operations have followed coronary artery bypass grafting as procedures that are amenable to a minimally invasive approach. This study is a review of our brief experiences of less invasive valve surgery (LIVS) through a partial sternotomy approach and port-access valve surgery (PAVS) with an attempt to compare safety and cost-effectiveness of the surgical procedure and post-discharge follow-up. METHODS: Forty PAVS and 66 LIVS procedures performed between May 1996 and December 1998 were reviewed. The PAVS patients were younger, included more men, and had greater left ventricular function. Aside from these particular data points, there was no significant difference in preoperative variables between groups. RESULTS: Operating room time, surgery time, and cross-clamp time were significantly longer in the PAVS group. The operative mortality was 3% (LIVS) and 5% (PAVS). There was more new atrial fibrillation in LIVS (26% versus 5%, p = 0.009). Postoperative follow-up revealed 77% of LIVS and 76% of PAVS patients had returned to work and more than 95% of the retired patients in both groups had resumed their daily activities. Importantly, PAVS patients returned to work about 4 weeks sooner than LIVS patients did. CONCLUSIONS: Early clinical outcomes are comparable between the two approaches, which indicates safety and importance of appropriate patient selection. More follow-up is required to assess postoperative pain and cosmetic satisfaction. At the present time, LIVS appears to be more cost-effective. Early return to work in the PAVS group may be the most important finding to further support the port-access approach. However, with practice pattern changes and increased intraoperative efficiencies, each of these two surgical techniques may continue to have an important role in the minimally invasive valve surgery arena.

Adult↗
PubMed1999

Evaluation of two new heart valve surgery techniques: partial sternotomy and port-access approaches.

OBJECTIVES: This review attempts to compare the port-access and partial sternotomy approaches of minimally invasive valve surgery. METHODS: Our brief experiences of the two techniques are summarized with an attempt to compare safety, cost-effectiveness of the procedure and post discharge follow-up. One hundred and two patients undergoing the procedures between May 1996 and October 1998 were analyzed. There were 65 patients in the partial sternotomy (MIV) group and 37 patients in the port-access (PAV) group. With the exception of a higher incidence of COPD in the MIV patients, there was no significant difference in pre-operative variables between these two groups. RESULTS: Total operating room time, surgery time and cross-clamp time were significantly increased in the PAV group. The operative mortality of patients with MIV was 3% (n = 2) while the PAV group was 8% (n = 3) (P = ns). More new atrial fibrillation was found in the MIV (26% versus 5%, P = 0.009). Otherwise, there was no significant complications observed in either group. During the 4-6 week follow-up, of those who were employed, 76% of MIV and 69% of PAV patients had returned to work. Of the retired patients more than 95% of the patients in both groups had resumed their daily routine activity. Importantly, the study showed PAV patients returned to work about 4 weeks sooner than MIV patients. CONCLUSIONS: MIV approach is more 'surgeon friendly' and can be carried out without increased intra-operative resource utilization. The PAV approach requires formal training and capital outlay for unique equipment, disposable and ancillary procedures. From a financial perspective, if the PAV technique is to become widely accepted intra-operative efficiencies must be maximized, post-operative fast-tract protocol must be utilized, financial expenditures for disposable equipment must decrease and requirement of ancillary procedures must be reduced.

Aged↗
PubMed1998

Donor-derived antibodies and hemolysis after ABO-compatible but nonidentical heart-lung and lung transplantation.

BACKGROUND: Organ donors and transplant recipients are routinely tested for ABO compatibility. ABO-identical organs are preferred, but occasionally the use of an ABO-compatible but nonidentical donor is clinically warranted. In heart-lung transplantation, the incidence of hemolysis from donor-derived anti-ABO antibodies is as high as 70%. The incidence of hemolysis for lung-only transplantation is not known. Our current posttransplantation transfusion policy for ABO-compatible but nonidentical lung-only transplant recipients is, when indicated, to use donor ABO group red blood cells. METHODS: To evaluate the efficacy of our transfusion policy, we reviewed our experience from 1986-96. One heart-lung transplant, four single lung transplant, and three bilateral single lung transplant recipients received ABO-compatible but nonidentical organs. RESULTS: The heart-lung transplant recipient developed a positive direct antiglobulin test (DAT), with anti-A eluted, and severe hemolysis on postoperative day 8 requiring plasma and whole blood exchange. Four of six lung-only transplant patients tested developed a positive DAT with anti-A eluted. Two early lung-only patients, who did not receive donor ABO group red blood cells, demonstrated clinical and laboratory evidence of hemolysis. Three bilateral lung transplant recipients were followed prospectively. The first patient had a negative DAT. The next two patients developed positive DATs on postoperative day 8 and 10, respectively. No evidence of hemolysis was detected in any of these cases. CONCLUSIONS: These results confirm that donor-derived anti-ABO antibodies develop with lung-only transplants. Our current transfusion policy is justified for both heart-lung and lung recipients of ABO-compatible but nonidentical organs. A high index of suspicion for donor-derived antibody causing hemolysis and communication with blood bank personnel are mandatory in this setting.

ABO Blood-Group System↗
PubMed1998

Implantation technique of aortic homograft root: emphasis on matching the host root to the graft.

The technique of homograft aortic root replacement in our practice has evolved as our experience has increased. This technique is described and illustrated. In most cases, aortic annuli are reduced by using various suture techniques to match the homograft. This allows for a successful implantation of a normal-sized aortic homograft root in a patient with a diseased aortic valve and annular dilatation.

Anastomosis, Surgical↗
PubMed1997

Early and late airway complications after lung transplantation: incidence and management.

BACKGROUND: Airway anastomosis complications continue to be a source of morbidity for lung transplant recipients. METHODS: This study analyzes incidence, treatment, and follow-up of airway anastomotic complications occurring in 127 consecutive lung transplant airway anastomoses (77 single lung and 25 bilateral sequential lung). Complications were categorized as stenosis (11), granulation tissue (8), infection (7), bronchomalacia (5), or dehiscence (3). Follow-up after treatment ranged from 6 months to 4 years. RESULTS: Nineteen airway anastomosis complications (15.0%) occurred in 18 patients. Telescoping the airway anastomosis reduced the complication rate to 12 of 97 (12.4%), compared with 7 of 30 (23.3%) for omental wrapping, (p = 0.15). Complications developed in 13 of 77 single-lung airway anastomoses (16.9%) versus 6 of 50 bilateral sequential lung recipients (12.0%). Treatment consisted of stenting (9 airway anastomoses), bronchodilation (8), laser debridement (4), rigid bronchoscopic debridement (2), operative revision (2), and growth factor application (2). There was no difference in actuarial survival between patients with or without airway anastomosis complications (p = 1.0). CONCLUSIONS: Airway anastomosis complications can be successfully managed in the immediate or late postoperative period with good outcome up to 4 years after intervention.

Adult↗
PubMed1997

Risk factors for the development of bronchiolitis obliterans syndrome after lung transplantation.

OBJECTIVE: This study identifies specific clinical and immunologic factors in lung transplant recipients that influence the subsequent development of chronic allograft dysfunction. METHODS: The study group consisted of 132 consecutive patients who received lung allografts (76 single, 25 bilateral single, and 31 heart-lung) and survived at least 90 days. One hundred twenty-one patients were used in the analysis that modeled time to development of histologic obliterative bronchiolitis or bronchiolitis obliterans syndrome. RESULTS: Variables noted to have an effect on the time to development of bronchiolitis obliterans syndrome included cytomegalovirus pneumonitis (RR = 3.2, p = 0.001), late acute rejection (RR = 1.3, p = 0.02), human leukocyte antigen mismatches at the A loci (RR = 1.8, p = 0.02), total human leukocyte antigen mismatches (RR = 1.4, p = 0.04), and absence of donor antigen-specific hyporeactivity (52% vs 100% survival free from bronchiolitis obliterans syndrome at 2 years; p = 0.005). Cytomegalovirus pneumonitis had a significant effect on time to obliterative bronchiolitis (RR = 3.6, p = 0.0005), as did donor antigen-specific hyporeactivity (52% vs 100% survival free from obliterative bronchiolitis at 2 years; p = 0.01). In multivariate analysis, cytomegalovirus pneumonitis (RR = 3.2, p = 0.02), human leukocyte antigen mismatches at the A loci (RR = 2.4, p = 0.006), and late acute rejection (RR = 1.3, p = 0.02) were identified as predictors of bronchiolitis obliterans syndrome. Cytomegalovirus pneumonitis was associated with time to development of histologic obliterative bronchiolitis (RR = 2.3, p = 0.02). CONCLUSIONS: Several risk factors were associated with the development of chronic allograft dysfunction, which, in turn, had a significant impact on long-term survival. Early identification of lung allograft recipients with risk factors for the development of bronchiolitis obliterans syndrome may allow modification in immunosuppression and antiviral therapy to potentially decrease the prevalence of this disorder.

Adult↗
PubMed1996

Primary pulmonary hypertension as a risk factor for the development of obliterative bronchiolitis in lung allograft recipients.

STUDY OBJECTIVES: Obliterative bronchiolitis (OB) is a major factor limiting long-term survival after lung transplantation. The etiology of this disease process remains incompletely understood. Several risk factors have been identified previously, including acute rejection and cytomegalovirus pneumonitis. The purpose of this study was to evaluate primary pulmonary hypertension (PPH) as a potential risk factor for the development of OB after lung transplantation. DESIGN AND PATIENTS: We retrospectively analyzed 107 lung allograft recipients (28 heart-lung, 18 bilateral sequential single-lung, 61 single-lung) who underwent transplantation between May 1, 1986, and April 30, 1994, and survived at least 3 months posttransplant. Mean follow-up posttransplant was 28.6 months (range, 3.5 to 99 months). Actuarial survival was estimated for patients with or without PPH and for those who did or did not develop OB. RESULTS: In all, 25 patients (23.4%) developed OB, diagnosed by strict histologic criteria. Of 23 patients with PPH, 9 (39.1%) developed OB, compared with 16 (19.0%) of 84 patients without PPH (p = 0.044). Actuarial survival, sex, time on waiting list, and follow-up posttransplant were not significantly different between groups. PPH was the major determinant for the development of OB (p = 0.0468) when evaluating PPH and cytomegalovirus pneumonitis together as risk factors. Patients with PPH also developed OB significantly earlier posttransplant, compared with patients with other primary disease (p = 0.05). CONCLUSIONS: Patients with PPH who undergo lung transplantation are at increased risk for the development of OB, which also occurs at a shorter time interval posttransplant. This subgroup needs aggressive monitoring for diagnosis and treatment of OB.

Adolescent↗
PubMed1996

Does donor organ ischemia over four hours affect long-term survival after lung transplantation?

BACKGROUND: Lung transplantation is currently limited by a donor shortage and the need for a short organ ischemic time. The purpose of this analysis was to evaluate prolonged donor organ ischemia and its effect on overall survival. METHODS: We conducted a retrospective analysis of 83 patients undergoing single (n = 62) or bilateral sequential lung transplantation (n = 21) from June 1, 1989, through July 31, 1994. All allografts were flushed with modified EuroCollins solution at 4 degrees C and stored in cold saline solution. Ischemic time was measured from aortic crossclamping at organ procurement to reperfusion. Ischemic times were divided into three groups: group I < 240 minutes (n = 39), group II 240 to 360 minutes (n = 36), and group III > 360 minutes (n = 8). Ischemic times ranged from 97 to 708 minutes (median, 245 minutes; mean, 252 minutes). Bilateral sequential and single lung transplantations were considered together. RESULTS: Actuarial survival was not significantly different among groups (p = 0.09). We found no significant difference in time spent in the intensive care unit (p = 0.27) or in total hospital stay (p = 0.57) after transplantation, in forced expiratory volume in 1 second at 1 month after transplantation (p = 0.74), or in the number of acute rejection episodes (p = 0.65). In addition, length of follow-up was similar among groups (p = 0.24). CONCLUSIONS: Prolonged donor allograft ischemic times were not associated with an adverse effect on survival. The use of allografts with ischemic times through 6 hours achieved acceptable 2-year survival rates after transplantation. The use of donor organs with prolonged ischemic times should prompt the United Network for Organ Sharing to move toward better allocation of donor organs.

Actuarial Analysis↗
PubMed1996

Unilateral volume reduction after single-lung transplantation for emphysema.

BACKGROUND: Single-lung transplantation has become accepted therapy for patients with end-stage emphysema. Hyperinflation of the native lung can occur after single-lung transplantation with mediastinal shifting and compression of the transplanted lung. A volume reduction operation (pneumectomy) [corrected] may relieve symptoms of dyspnea and improve exercise tolerance. METHODS: Three of 66 patients who underwent single-lung transplantation for emphysema had development of native lung hyperexpansion and mediastinal shifting causing compression of the transplanted contralateral lung at 12, 17, and 42 months after transplantation. There were 2 men and 1 woman. Unilateral volume reduction was performed without complication in all 3 patients. RESULTS: All patients were noted to have marked improvement in chest radiographs after volume reduction, substantial relief of dyspnea, and improvement in exercise tolerance. An improvement in pulmonary function test results was noted in 1 patient, but tests were not done for the other 2 patients. CONCLUSIONS: Patients with chronic obstructive pulmonary disease who undergo single-lung transplantation may have symptomatic hyperexpansion of the native lung requiring volume reduction months to years after transplantation. Unilateral volume reduction can be safely performed in the posttransplantation period.

Adult↗
PubMed1995

Surfactant dysfunction in lung preservation.

We studied the effect of lung preservation on the surfactant system in rats. Lung surfactant is necessary to maintain normal lung mechanics, and hence normal lung function. We evaluated lung mechanics with pressure-volume (P-V) curves, and analyzed biochemical changes of surfactant in bronchoalveolar lavage (BAL) fluid. Additionally, we determined wet to dry weight ratios (W/D). We defined five study groups. In group I (controls) we harvested lungs without pulmonary artery flushing, then evaluated them immediately. In group II we flushed lungs through the pulmonary artery (PA) with hypothermic modified Euro-Collins solution (mECS), then removed and studied them immediately to determine the consequences of PA flushing alone. In groups III, IV, and V we flushed lungs with mECS, then stored them in normal saline (NS) for 6 hr (group III); in NS for 12 hr (group IV); or in mECS for 12 hr (group V). In groups III, IV, and V we evaluated lungs after storage. All four experimental groups showed significant changes in lung mechanics and surfactant biochemistry, compared with controls. Lungs in groups III, IV, and V showed additional changes in lung mechanics and surfactant biochemistry compared with group II. The W/D in stored lungs (groups III, IV, and V) was significantly higher than in controls and group II. We conclude that lung preservation induces deleterious changes in the surfactant system. Surfactant alterations are evident immediately after pulmonary artery flushing, and increase in severity with storage.

Animals↗
PubMed1995

Suicide right ventricle after lung transplantation for Eisenmenger syndrome.

Right ventricular outflow tract obstruction, or "suicide right ventricle," rarely has been observed after single or bilateral single-lung transplantation for the treatment of Eisenmenger syndrome. We describe our experience in 2 patients with Eisenmenger syndrome in whom right ventricular outflow tract obstruction developed, in 1 after single-lung transplantation and ventricular septal defect repair and in the other after bilateral single-lung transplantation. Both patients suffered progressive deterioration and hemodynamic instability that was unresponsive to aggressive medical therapy. Diagnosis was confirmed in both patients by transesophageal echocardiography. Operative intervention was undertaken 72 and 24 hours after transplantation, and consisted of myectomy and outflow tract patching. One patient survived; the other died intraoperatively. The index of suspicion for this problem should be high during the intraoperative performance of transesophageal echocardiography, as well as during direct gradient measurement, with consideration of immediate management of severe right ventricular outflow tract obstruction at the time of transplantation.

Adult↗
PubMed1995

Deep venous thrombosis and pulmonary embolism after lung transplantation.

The incidence of deep venous thrombosis or pulmonary embolism after lung or heart-lung transplantation has not been well defined. Pulmonary embolism may be of particular concern in the postoperative period owing to an inadequately developed or absent collateral bronchial circulation and potential risk of pulmonary infarction. Fourteen (12.1%) of 116 patients undergoing either lung (n = 87) or heart-lung (n = 29) transplantation developed thromboembolic complications 10 days to 36 months after operation. Deep vein thrombosis developed in nine patients, including three with upper body thrombosis related to indwelling central venous catheters. Seven patients (6%) had pulmonary embolism, and three of them died. Resolution of pulmonary embolism was successfully accomplished by selective pulmonary artery infusion of urokinase in three patients without complications. Our experience indicates that deep vein thrombosis and pulmonary embolism are significant problems after lung transplantation. Mortality is high in those patients in whom pulmonary embolism develops. Therefore, a comprehensive prevention protocol is warranted.

Adult↗
PubMed1994

Experimental large-animal model of obliterative bronchiolitis after lung transplantation.

Obliterative bronchiolitis is a major cause of long-term morbidity after lung transplantation. It is characterized by small-airway inflammation and occlusion by fibrous tissue. The pathogenesis is uncertain. To study this disease, we developed a model of posttransplantation obliterative bronchiolitis using genetically defined miniature swine. Group 1 (n = 2) received a left lung autograft; group 2 (n = 7), a left lung allograft. Group 2 recipients were given cyclosporine, prednisone, and azathioprine for 3 months, then immunosuppression was tapered and discontinued over 1 month. The animals were observed for an additional 2 months, then sacrificed. Lung grafts in both groups were monitored with serial bronchoalveolar lavages and transbronchial biopsies for 6 months. After sacrifice, lung grafts underwent histopathologic and immunohistochemical examination. No allograft had histologic evidence of acute rejection or peribronchiolar infiltrate during the first 3 months of immunosuppression. During the tapering period, airway changes characterized by severe peribronchiolar lymphocytic infiltrates were seen. Bronchoalveolar lavages of allografts showed significantly increased lymphocyte counts with CD8+ cells predominating. After the discontinuation of immunosuppression, transbronchial biopsy and autopsy specimens showed progressive fibrous inflammatory occlusion of bronchioles. Immunohistochemical staining demonstrated increased expression of MCH class II antigen on the bronchiolar epithelium and increased dendritic cells and CD4+ lymphocytes. None of these changes were seen in group 1. Our findings suggest obliterative bronchiolitis is an immunologically mediated phenomenon related to chronic graft rejection after lung transplantation. This model will allow systematic study of the pathogenesis of obliterative bronchiolitis and possible therapeutic intervention.

Animals↗