Dobutamine Stress Echocardiography Is Highly Accurate for the Prediction of Contractile Reserve in the Early Postoperative Period, but May Underestimate Late Recovery in Contractile Reserve After Revascularization of the Hibernating Myocardium

OBJECTIVE

We sought to investigate the accuracy of dobutamine stress echocardiography to predict the degree and timing of recovery in resting function and contractile reserve (CR) after revascularization of the hibernating myocardium.

METHODS

In all, 24 patients with ischemic cardiomyopathy (ejection fraction < 40%) underwent dobutamine stress echocardiography 1 week before and 6 weeks, 3 months, and 6 months after coronary artery bypass grafting.

RESULTS

Recovery rates at 6 weeks, 3 months, and 6 months postoperation were 21%, 33%, and 45% (P < .01) for resting function and 55%, 65%, and 74% (P < .01) for CR. Positive and negative predictive values for recovery of resting function and CR at 6 months postrevascularization were 66% vs 97% (P < .001) and 78% vs 48% (P < .001), respectively. Positive and negative predictive values were both high for recovery of CR at 6 weeks postrevascularization (89% and 78%).

CONCLUSIONS

Dobutamine stress echocardiography can predict early recovery in CR postrevascularization with an excellent accuracy but may underestimate the degree of late recovery in CR.

Hypothesis: epithelial-to-mesenchymal transition is a common cause of chronic allograft failure

Renal, hepatic, and lung allografts are compromised by aggressively deteriorating function. This chronic process is produced by an overall burden of organ damage, but the pathophysiology remains poorly understood. Rates of chronic rejection in the lung, for example, have not substantially improved over the last decade, despite new immunosuppressive drugs and improvements in surgical procedure. We present a hypothesis that epithelial-to-mesenchymal transition is a common cause of chronic allograft failure. Research in this area may provide insights into chronic rejection of kidney, liver, and lung allografts that impact on future therapeutic strategies.

Pepsin like activity in bronchoalveolar lavage fluid is suggestive of gastric aspiration in lung allografts

BACKGROUND

A biologically plausible link between gastro-oesophageal reflux (GOR), aspiration, and lung allograft dysfunction has been suggested, but there is no systematic evidence indicating the presence of gastric contents in the lung. We have tested the hypothesis that pepsin, as a marker of aspiration, is detectable in bronchoalveolar lavage (BAL) fluid of allograft recipients who had not reported symptoms of GOR.

METHODS

Standardised 3 x 60 ml surveillance BAL fluid samples from 13 chronologically sequential stable lung allograft recipients without chronic rejection (10 patients treated with a prophylactic proton pump inhibitor) were studied. Lavage supernatants were assayed by an ELISA based on a monospecific goat antibody for pepsin/pepsinogen. Pepsin levels were compared with those from four normal volunteer controls.

RESULTS

Pepsin levels were measurable in all allograft recipients, in keeping with gastric aspiration (median 109 ng/ml (range 35-1375)). In the control group the pepsin levels were below the limit of detection. Treatment with a proton pump inhibitor was not correlated with pepsin levels. There was no correlation between BAL fluid neutrophils and pepsin levels.

CONCLUSION

These data demonstrate lung epithelial lining fluid concentrations of pepsin in lung allograft recipients which are much higher than blood reference levels, with no detectable pepsin in controls. This provides direct evidence of gastric aspiration, which is potentially injurious to the allograft.

Pepsin like activity in bronchoalveolar lavage fluid is suggestive of gastric aspiration in lung allografts

BACKGROUND

A biologically plausible link between gastro-oesophageal reflux (GOR), aspiration, and lung allograft dysfunction has been suggested, but there is no systematic evidence indicating the presence of gastric contents in the lung. We have tested the hypothesis that pepsin, as a marker of aspiration, is detectable in bronchoalveolar lavage (BAL) fluid of allograft recipients who had not reported symptoms of GOR.

METHODS

Standardised 3 x 60 ml surveillance BAL fluid samples from 13 chronologically sequential stable lung allograft recipients without chronic rejection (10 patients treated with a prophylactic proton pump inhibitor) were studied. Lavage supernatants were assayed by an ELISA based on a monospecific goat antibody for pepsin/pepsinogen. Pepsin levels were compared with those from four normal volunteer controls.

RESULTS

Pepsin levels were measurable in all allograft recipients, in keeping with gastric aspiration (median 109 ng/ml (range 35-1375)). In the control group the pepsin levels were below the limit of detection. Treatment with a proton pump inhibitor was not correlated with pepsin levels. There was no correlation between BAL fluid neutrophils and pepsin levels.

CONCLUSION

These data demonstrate lung epithelial lining fluid concentrations of pepsin in lung allograft recipients which are much higher than blood reference levels, with no detectable pepsin in controls. This provides direct evidence of gastric aspiration, which is potentially injurious to the allograft.

Azithromycin reverses airflow obstruction in established bronchiolitis obliterans syndrome

INTRODUCTION

A recent pilot study noted clinical benefit of macrolide therapy in the management of six lung transplant recipients with bronchiolitis obliterans syndrome (BOS), a condition previously regarded as irreversible.

OBJECTIVE

To examine the effect of low-dose macrolides on lung function in lung allograft recipients with established BOS and to assess whether this benefit is sustained.

METHODS

We retrospectively evaluated the effect of azithromycin (250 mg alternate days) on clinical status and lung function in 20 allograft recipients with established BOS, confirmed by decline in FEV(1) or FEF(25-75); consistent high-resolution computed tomography findings; and exclusion of acute rejection, infection, or anastomatic complications. Azithromycin was introduced at mean 82 months after transplantation. BOS staging at initiation of treatment was BOS 3 (10), BOS 2 (2), BOS 1 (6), and BOS0-p (2). All patients were on maintenance immunosuppression comprising cell-cycle inhibitor, oral corticosteroids, and calcineurin inhibitor.

RESULTS

There was a significant increase in FEV(1) of median 110 ml (range, -70 to 730 ml) between baseline and 3 months of azithromycin therapy (p = 0.002). This improvement was sustained beyond 3 months in the majority of patients, who had initially benefited from azithromycin (up to 11 months follow up).

CONCLUSIONS

This case series confirms the benefit of azithromycin in not only halting, but reversing the declining lung function seen in patients with BOS. This benefit appears to be maintained over time. Low-dose macrolides offer a new and exciting therapeutic strategy for the treatment of progressive BOS, and further clinical and translational mechanistic studies are required.

Phenotype of airway epithelial cells suggests epithelial to mesenchymal cell transition in clinically stable lung transplant recipients

BACKGROUND

Obliterative bronchiolitis in chronic rejection of lung allografts is characterised by airway epithelial damage and fibrosis. The process whereby normal epithelium is lost and replaced by fibroblastic scar tissue is poorly understood, but recent findings suggest that epithelial cells can become fibroblasts through epithelial-mesenchymal transition (EMT). It is hypothesised that EMT occurs in lung allografts and plays a potential role in airway remodelling.

METHODS

Sixteen stable lung transplant recipients underwent bronchoscopy with bronchoalveolar lavage (BAL), endobronchial biopsies, and bronchial brushings. Biopsy sections were stained for the fibroblast marker S100A4. Brushings were cultured on collagen, stained with anti-S100A4, and examined for further EMT markers including matrix metalloproteinase (MMP) zymographic activity and epithelial invasion through collagen coated filters.

RESULTS

A median 15% (0-48%) of the biopsy epithelium stained for S100A4 in stable lung transplant recipients and MMP-7 co-localisation was observed. In non-stimulated epithelial cultures from lung allografts, S100A4 staining was identified with MMP-2 and MMP-9 production and zymographic activity. MMP total protein and activity was increased following stimulation with transforming growth factor (TGF)-beta1. Non-stimulated transplant epithelial cells were invasive and penetration of collagen coated filters increased following TGF-beta1 stimulation.

CONCLUSIONS

This study provides evidence of EMT markers in lung allografts of patients without loss of lung function. The EMT process may represent a final common pathway following injury in more common diseases characterised by airway remodelling.

Functional status and quality of life in patients surviving 10 years after lung transplantation

Although many lung allograft recipients achieve long-term survival, there is a lack of published data regarding these patients' functional status and quality of life (QoL). We evaluated all 10-year survivors at our institution and, utilizing the SF-36 questionnaire, compared their QoL to population normative and chronic illness data. Twenty-eight (29%) of 96 patients survived > or =10 years following 11 single, 6 bilateral and 11 heart-lung procedures. At the most recent evaluation, median FEV(1) in single and double lung recipients was predicted to be 54% and 74%, respectively. Five (18%) patients had BOS score 0, 13 (46%) BOS 1, 5 (18%) BOS 2 and 5 (18%) BOS 3 and median time to BOS was 7 years. Four (14%) patients required renal replacement therapy. Three patients (11%) developed symptomatic osteoporosis, 2 (7%) post-transplant lymphoma and 1 (4%) an ischaemic stroke. Scores for physical function, role-physical/emotional and general health, but not mental health and bodily pain, were significantly lower compared to normative and chronic illness data. Energy and social-function scores were significantly lower than normative data alone. Long-term survival after lung transplantation is characterized by an absence or delayed development of BOS, low iatrogenic morbidity and preserved mental, but reduced physical health status.

The hemodynamic mechanisms of lung injury and systemic inflammatory response following brain death in the transplant donor

Brain-dead donors are the major source of lungs for transplantation. Brain death is characterized by two hemodynamic phases. Initially, massive sympathetic discharge results in a hypertensive crisis. This is followed by neurogenic hypotension. Up-regulation of pro-inflammatory mediators occurs in all organs and lung injury develops; this can adversely affect graft function post-transplantation. The mechanisms of the systemic and lung inflammation are unknown. We hypothesized that the hemodynamic changes are responsible for these inflammatory phenomena. Brain death was induced by intra-cranial balloon inflation in rats. This resulted in hypertensive crisis, followed by hypotension. There was a significant increase in blood neutrophil CD11b/CD18 expression and pro-inflammatory cytokine levels in serum and bronchoalveolar lavage, compared with control animals. Rupture of the capillary-alveolar membrane was demonstrated by electron microscopy. Elimination of the hypertensive response by alpha-adrenergic antagonist pre-treatment prevented inflammatory lung injury, reduced the systemic inflammatory markers and preserved capillary-alveolar membrane integrity. Correction of the neurogenic hypotension with noradrenaline ameliorated the systemic inflammatory response and improved oxygenation. We conclude that the sympathetic discharge triggers systemic and lung inflammation, which can be further enhanced by neurogenic hypotension. Management of the brain-dead donor with early anti-inflammatory treatment and vasoconstrictors is warranted.

The safety and efficacy of total lymphoid irradiation in progressive bronchiolitis obliterans syndrome after lung transplantation

Total lymphoid irradiation (TLI) has been used to control renal and cardiac allograft rejection. Data evaluating TLI in bronchiolitis obliterans syndrome (BOS), the physiological manifestation of chronic lung allograft rejection, is very limited. We present our single center experience of the safety and efficacy of TLI in controlling progressive BOS in a retrospective study. Over 12 years, 37 lung recipients (16 M:21 F) who had undergone 13 single; 12 bilateral and 12 heart-lung transplants were treated with TLI for progressive BOS. Grades at time TLI given were BOS 1 (n = 7) BOS 2 (n = 14) BOS 3 (n = 16). Twenty-seven (73%) completed >8/10 fractions, 10 (27%) failed to complete TLI. Two died from advanced BOS during treatment, 8 stopped early (range 3-7 fractions) due to marrow suppression (6) or infection (2). In the 27 recipients who completed >8/10 fractions, decline in FEV1 was 122.7 mls/month pre-TLI and 25.1 mls/month post-TLI, p = 0.0004, mean (95% CI) change in rate of decline was 97.5 (48.2-146.7) mls/month. TLI significantly reduces the rate of decline in graft function associated with BOS. TLI is well tolerated and associated with few serious complications and is an appropriate immunosuppressive approach in progressive BOS.

Objective assessment of criteria for selection of donor lungs suitable for transplantation

BACKGROUND

Donor organ shortage severely limits lung transplantation as a therapeutic option, yet many potential donor lungs are deemed unsuitable by clinical selection criteria.

METHODS

Of 39 consecutive potential donor lungs, 14 were accepted and 25 excluded by clinical selection criteria. All were evaluated prospectively by clinical assessment, bronchoscopy, and bronchoalveolar lavage (BAL) to evaluate objectively the discrimination of pulmonary infection and injury.

RESULTS

Accepted donors were significantly younger than those excluded (mean (SD) age 36.7 (15.3) years v 49.5 (13.2) years; p = 0.009, unpaired t test) and were more likely to have suffered traumatic brain death (50% v 20%; p = 0.07, Fisher's exact test). Oxygenation (PaO(2):FiO(2)) was higher in accepted donors than in excluded donors (median (range) 63.2 (48-82.5) kPa v 43.1 (7.7-71.7) kPa; p = 0.0001, Mann-Whitney test). Positive formal BAL culture was more frequent in accepted donors (75%) than in those excluded (43%; p = 0.1, Fisher's exact test). There was no significant difference in the percentage and concentration of neutrophils in BAL fluid between accepted and excluded donors (median (range) 37.9 (0-96.9)% and 44.6 (0-1190)x10(3)/ml v 36 (1-98.1)% and 46 (0.2-1457)x10(3)/ml), nor in the BAL fluid concentration of tumour necrosis factor-alpha (140 (0-340) pg/ml v 160 (0-760) pg/ml) or interleukin 8 (810 (33-17 600) pg/ml v 540 (0-15 110) pg/ml).

CONCLUSION

Current selection criteria are poor discriminators of pulmonary injury and infection and lead to the exclusion of potentially usable donor lungs.

ABO-INCOMPATIBLE HEART TRANSPLANTATION IN INFANTS: THE FREEMAN HOSPITAL EXPERIENCE

BACKGROUND

Incompatibility of the major blood groups A, B, and O has been an absolute contraindication for heart transplantation. However, because of immunologic immaturity, infants may have relative protection from hyperacute rejection and thus could undergo transplantation with ABO-mismatched organs.

METHODS

Since January 2000, the authors have adopted a policy of considering infants for ABO-incompatible heart transplantation. Serum isohemagglutinin titers were measured before, during, and after transplantation. Two infants (3 and 2 months old) and a 21-month-old child underwent ABO-incompatible heart transplantation. During cardiopulmonary bypass, plasma exchange was performed. No other antibody-removal procedures were performed. A routine immunosuppressive regimen was used, and rejection was monitored by endomyocardial biopsies. An additional two patients (31 and 18 months old) were worked up but were unsuitable for ABO-incompatible transplantation because of high isohemagglutinin titers. They were successfully bridged to transplantation and received heart transplants from ABO-compatible donors.

RESULTS

All three infants with ABO-incompatible heart transplants are fit and well, 40 months, 30 months, and 12 months postoperatively. All three had serum antibodies to antigens of the donor's blood group before transplantation. No hyperacute rejection occurred. No morbidity attributable to the ABO incompatibility has been observed.

CONCLUSIONS

ABO-mismatched heart transplantation may be undertaken safely and without any short-term adverse consequences in infants and young children in whom isohemagglutinin production is not yet established.

Lung transplantation: pulmonary cell lysis mediated by alveolar mononuclear cells

Methods were developed to monitor graft rejection in a porcine model of unilateral lung transplantation. The ability of peripheral blood mononuclear cells and lavage-derived mononuclear cells to lyse donor pulmonary tissue was determined by standard chromium release assays at various times after transplantation. Effective antigraft activity was observed in the local environment of a rejecting graft, but not in the periphery. Since transplant rejection is a reversible process, with the administration of suitable immunosuppressive regimes frequently restoring graft function, it was reasoned that immunological assays based on the lysis of individual cells may not be relevant to the in vivo situation. We therefore describe an assay of the lung barrier function; perturbations of the tight intraepithelial junctions which compose the air-blood barrier can be determined in vitro by the measurement of transmonolayer resistance values.

Pentoxifylline is as effective as leukocyte depletion for modulating pulmonary reperfusion injury

OBJECTIVE

Previous studies have suggested the amelioration of lung reperfusion injury when initial reperfusion is undertaken with leukocyte-depleted blood. Pharmacologic agents, such as pentoxifylline, are also effective, but no previous studies have demonstrated which is superior. We investigated these agents in a porcine model of left single-lung transplantation.

METHODS

Donor lungs were preserved with modified Euro-Collins solution for a mean ischemic time of 18.6 hours. Gas exchange, pulmonary vascular resistance, neutrophil elastase level, and free radical release (measured on the basis of malonaldehyde levels) were assessed over a 12-hour period. Group A (n = 5) was a control group with no interventions added. Group B was reperfused through an extracorporeal circuit incorporating a leukocyte-depleting filter for 30 minutes before conventional blood flow was restored. Group C was reperfused with the addition of intravenous pentoxifylline (2 mg x kg(-1) x h(-1)).

RESULTS

Groups B and C were similar in terms of oxygenation, pulmonary vascular resistance, and free radical release. Group B displayed increased levels of neutrophil elastase. Both groups were superior with regard to these outcome measures compared with control group A.

CONCLUSIONS

Pentoxifylline, when administered to recipient animals, attenuates reperfusion injury to a degree similar to that seen with leukocyte-depleted reperfusion. This technique is simple, safe, and as effective as using a more complex extracorporeal circuit incorporating a leukocyte-depleting filter to ameliorate acute lung injury.

Bacterial colonization of the donor lower airways is a predictor of poor outcome in lung transplantation☆

OBJECTIVE

At the time of lung transplant, we routinely perform bronchoalveolar lavage (BAL) of the donor lungs on the recipient operating table immediately before implantation, for bacterial and fungal cultures. We sought to determine whether the results correlate with the outcome.

METHODS

We retrospectively analysed 115 consecutive cadaveric lung transplants (single lung: 42; bilateral lung: 63; heart-lung: 10) performed over 4 years.

RESULTS

Fifty-three (46%) grafts had positive BAL (bacteria: 33; fungus: 10; mixed: 10) and 62 (54%) were negative. Recipients with donor BAL culture positive for bacteria had lower mean oxygenation index in the first 6 h compared with those with negative bacterial culture (36.5+/-14.73 vs. 44.1+/-16.79 kPa) (P=0.019). They also had longer median intensive treatment unit stay (2.5 vs. 1.5 days) (P=0.035), and median time of mechanical ventilation (37.5 vs. 23.0 h) (P=0.008), as well as inferior 6-month, 1-year, 2-year and 4-year cumulative survival (79, 77, 74, 60% vs. 93, 92, 88, 79% respectively) (P=0.04). There was no difference in the above parameters between recipients with Gram-negative (n=18) and recipients with Gram-positive bacteria (n=19) in the donor BAL. Incidence of acute rejection within the first 2 weeks and time of onset of bronchiolitis obliterans syndrome (BOS) were similar in the bacteria-positive and bacteria-negative groups. Recipients with donor BAL positive for fungi alone had similar outcome with the negatives. There was no difference in the donor oxygenation index and age, recipient age, transplant type and ischaemic time between compared groups. There was a significant difference in the median length of donor mechanical ventilation between donors with Gram-positive and donors with Gram-negative bacteria in the BAL (24 vs. 48 h) (P=0.01), as well as between donors with fungi alone in the BAL and donors with negative BAL (67 vs. 48 h) (P=0.04).

CONCLUSIONS

Donor lungs with lower airways colonized with bacteria result in inferior recipient outcome. Bacterial colonization of the donor lower airways could therefore be used as a marker of donor lung injury, but evidence from a prospective study is necessary.

Pulmonary transplantation for cystic fibrosis: pre-transplant recipient characteristics in patients dying of peri-operative sepsis

BACKGROUND

Pulmonary transplantation has emerged as a successful treatment for end-stage cystic fibrosis. Despite the chronic bronchial sepsis and often multi-resistant organisms seen in this group of recipients, death due to post-operative sepsis is relatively scarce. Identifying potential recipient risk factors for poor outcome may further improve the utilization of a scarce donor pool.

METHODS

We assessed the role of pre-operative clinical measures of sepsis, microbial characteristics and recipient characteristics on post-transplant outcome in 85 cystic fibrosis patients who underwent pulmonary transplantation. Ten percent of patients died in the early post-operative period due to sepsis. The prognostic role of recipient factors including markers of sepsis, such as white cells and C-reactive protein (CRP), and the influence of multi-resistant organisms, in particular organisms from the Burkholderia cepacia complex, on outcomes were investigated.

RESULTS

We found no prognostic effect of gender, pre-transplant CRP, forced expiratory volume in 1 second (FEV(1)), weight, diabetic status or infection with multi-resistant Pseudomonas organisms. A raised white cell count or temperature or a pre-transplant infection with B cepacia was, however, associated with a significantly poorer prognosis at p = 0.03, 0.03 and 0.001, respectively.

CONCLUSIONS

Pre-operative B cepacia complex infection, leukocytosis and pyrexia, but not CRP, weight, diabetes or lung function, were found to be associated with poorer post-transplant outcome. The most clinically relevant of these to the subsequent risk of post-operative death from sepsis appear to be B cepacia infection and pyrexia.

Nitric oxide during perfusion improves posttransplantation function of non- heart-beating donor lungs

BACKGROUND

We attempted to determine in a pig model whether 20 ppm of nitric oxide (NO) during perfusion ameliorates warm ischemic lung injury in the non-heart-beating donor (NHBD), thereby improving function with longer warm ischemia.

METHODS

Lungs were retrieved from three groups (n=6): 1 hr (NHBD(1)) and 2 hr with and without NO (NHBD(2)NO, NHBD(2)) after hypoxic death. For assessment and preservation, left lungs were ventilated with 100% oxygen (NHBD(2)NO with added NO) and perfused for 20 min with neutrophil-depleted, deoxygenated blood in Perfadex solution. Pulmonary vascular and airway pressures and blood flow were measured with pulmonary venous blood gases. Perfusion temperature was reduced to 18 degrees C prior to storage at 4 degrees C before transplantation.

RESULTS

NO during perfusion significantly improved posttransplantation pulmonary venous oxygenation (NHBD(1) [mean +/- SD] 51+/-14 kPa, NHBD(2) 54+/-16 kPa, and NHBD(2)NO 61+/-6 kPa; P=0.01) and airway pressures (NHBD(1) 30.8+/-3.5, NHBD(2) 32.5+/-5.6, NHDB(2)NO 29.4+/-5.3; P=0.0001). NO significantly improved pulmonary vascular resistance (excluding the initial cold-induced vasoconstricted reperfusion period): NHBD(1) 19+/-9 Wood units, NHBD(2) 28+/-25 Wood units, NHDB(2)NO 16+/-10 Wood units, P=0.029. Neutrophil uptake was significantly lowered by NO: NHBD(1) 0.6+/-1.4*10(9) minute-1, NHBD(2) 1.2+/-1.0*10(9) minute-1, NHBD(2)NO 0.4+/-0.9*10(9) minute-1 (P=0.029).

CONCLUSIONS

This technique satisfactorily assesses and preserves the non-heart-beating lung. NO during preservation reverses the slight deterioration seen when increasing warm ischemia from 1 to 2 hr, significantly improving transplant oxygenation, vascular resistance, and airway pressures. This may be a result of the observed significant reduction in neutrophil sequestration.

Pulmonary transplantation: the role of brain death in donor lung injury

The paucity of suitable lung donors and the high early mortality as the result of primary graft failure remain major challenges in pulmonary transplantation. There is evidence that the lung is injured in the donor by the process of brain death and often is made unusable or fails posttransplantation after amplification of the injury by the process of ischemia-reperfusion. An understanding of the mechanism of donor lung injury could lead to the development of new treatment strategies for the donor to reduce lung injury, increase the number of donors with acceptable lungs, and improve the results of transplantation. The pathophysiology of brain death is complex and involves sympathetic, hemodynamic, and inflammatory mechanisms that can injure the lung. The literature is reviewed, and these mechanisms are discussed together with their possible interrelations.

Mediastinitis in heart and lung transplantation: 15 years experience

BACKGROUND

Mediastinitis after sternotomy carries a very high mortality, especially in patients receiving immunosuppressive treatment.

METHODS

A retrospective analysis of the data for patients who had undergone cardiopulmonary transplantation between May 1985 and December 2000 was undertaken. A total of 776 patients had either a median sternotomy or a transverse sternotomy through a clam-shell incision. Transplantations were as follows: 591 heart (3 simultaneous heart and renal, and 1 heart and liver), 126 bilateral sequential lung, 57 heart-lung, 1 en bloc double-lung, and 1 heart and single-lung.

RESULTS

In all, 21 (2.7%) recipients had mediastinitis. Of these, 14 had heart, 3 heart-lung, and 4 bilateral lung transplantation. There were 18 median and 3 transverse sternotomies. There were 6 deaths (28.6%). Treatment consisted of antibiotics alone in 2 patients and subxiphisternal drainage in another 2 patients. The sternum was reopened in 17 (80.95%) patients, with debridement and primary closure alone in 5 of these 17 patients and additional irrigation in the other 12. Those who had resternotomy, debridement, and substernal irrigation had a better outcome when compared with the outcomes of other modes of treatment (1 death among 12 patients) (p = 0.06). Age, cardiopulmonary bypass time, body mass index, time to diagnosis, and treatment did not differ between those who survived and those who did not.

CONCLUSIONS

Early aggressive debridement with substernal irrigation is the best mode of treatment for patients with posttransplantation mediastinitis.

Improvements in lung compliance after pulmonary transplantation: correlation with interleukin 8 expression

OBJECTIVE

Previous studies have suggested reductions in lung reperfusion injury when initial reperfusion is undertaken with the addition of pharmacological modulators. We investigated three pharmacological agents in a porcine model of left single lung transplantation to determine the effect on lung compliance and its relationship with the expression of the cytokine, interleukin-8 (IL-8).

METHODS

Donor lungs were preserved with modified Euro-Collins for a mean ischaemic time of 18.6 h. Pulmonary venous oxygenation, lung compliance and IL-8 expression were assessed over a 12-h period. Group A (n=5) was a control group with no interventions added, Group B was reperfused with the addition of intravenous inositol hexakisphosphate (InSP6) (0.02 mg/kg per min), Group C received the nitric oxide donor, 3-morpholinosydnonimine (SIN-1) (0.02 mg/kg per min) and Group D received intravenous Pentoxifylline (2 mg/kg per h). All interventions were administered at a pulmonary artery pressure of 20 mmHg.

RESULTS

Group D yielded the best oxygenation (P=0.0041) while Groups B and C were similar. All were superior to Group A (P<0.001). Lung compliance was significantly improved in Groups B, C and D compared to group A. In Group D, the greatest improvements in lung compliance were observed (P<0.0001). Similar observations were seen with regard to pulmonary vascular resistance. IL-8 expression was delayed until after 30 min of reperfusion in Group D, but was evident after 10 min in all the other groups. This correlates with the compliance and oxygenation data.

CONCLUSIONS

The addition of InSP6 or SIN-1 at reperfusion significantly attenuates reperfusion injury compared with controls and improves lung compliance. The unique comparison with Pentoxifylline afforded by this study indicates that at the doses studied Pentoxifylline appears to be superior, correlating with a greater inhibition of IL-8 expression.

Perfadex for clinical lung procurement: is it an advance?

BACKGROUND

Extensive laboratory experience suggested that low potassium dextran lung preservation solution (Perfadex; Medisan, Uppsala, Sweden) is superior to Euro-Collins (EC; Frusen, Hamburg, Germany), the clinical standard. The purpose of this study was to evaluate Perfadex in clinical lung transplantation.

METHODS

A retrospective analysis of the outcome of 69 consecutive lung allografts retrieved and used for transplantation was made. Donor lungs were flushed with EC in 37 patients and Perfadex in 32 patients. The evaluation measurements were quantitative chest roentgenogram score (grade 0 to 4), graft oxygenation, duration of mechanical ventilation, length of intensive care treatment, and survival.

RESULTS

The mean chest roentgenogram score was 1.55 and 1.81 for the EC group compared with 1.18 and 2.09 for the Perfadex group at 1 and 48 hours, respectively (p = 0.1 and 0.8, respectively). Arterial alveolar oxygen tension ratio was similar at 12 and 24 hours (0.61 vs 0.67; p = 0.8; and 0.64 vs 0.53; p = 0.3, respectively). The mean ventilation time was 71.2 +/- 32.3 hours versus 81.9 +/- 43.6 hours for the EC and Perfadex groups, respectively (p = 0.4). The mean intensive therapy unit stay was 3.1 +/- 2.6 days for the EC group compared with 4.1 +/- 3.9 days for the Perfadex group (p = 0.4). Death caused by primary organ failure was 5.1% for the EC group compared with 3.1% for the Perfadex group (p = 0.8).

CONCLUSIONS

There was no difference between Perfadex and EC in clinical lung preservation. This may reflect the difference between controlled laboratory environment and the real world of brain death lung injury. Further studies are required to investigate the impact of Perfadex in the long-term outcome of lung transplantation.

Pediatric cardiac transplant: results using a steroid-free maintenance regimen

We report on survival, rejection, lymphoma and renal function following cardiac transplant using a steroid-free maintenance immunosuppressive regimen. We have performed 73 cardiac transplants in 71 children under 16 yr of age in the last 12 yr. There were eight perioperative and four late deaths giving actuarial survival of 88, 88, 85 and 70% at 1, 2, 5 and 10 yr, respectively. A total of 11 (15.3%) children had one episode of rejection (grade 3) in the first 6 months; one died and one was re-transplanted because of rejection. There was only one episode of late rejection (8 yr post-transplant) because of low drug levels in a patient with lymphoma and sepsis. This patient did not survive. Three other children (5.6%) also developed lymphoma and recovered but one died subsequently of graft failure. Four children have developed severe renal failure (glomerular filtration rate GFR <30 mL/min/m2). Two have not survived and one is expected to commence dialysis soon. The remainder have mild to moderate renal impairment. We report excellent survival and low rejection rates without use of long-term steroids. However the doses of cyclosporin used have had a significant effect on renal function in many cases.

Activity of disinfectants against Gram-negative bacilli isolated from patients undergoing lung transplantation for cystic fibrosis

Lung transplant recipients with cystic fibrosis are frequently colonized with antibiotic-resistant bacteria. We evaluated the in vitro activity of 5 disinfectants frequently used in cardiac surgery against strains of Burkholderia cepacia and Pseudomonas aeruginosa isolated from patients undergoing sequential single lung transplantation. Our results suggest that the activity of Taurolin and Noxyflex is superior to conventional disinfectants.