Carsten Lührs

Clinical transplantation of initially rejected donor lungs after reconditioning ex vivo.

BACKGROUND A major problem in clinical lung transplantation is the shortage of donor lungs. Only about 20% of donor lungs are accepted for transplantation. A method to evaluate and recondition lungs ex vivo has been tested on donor lungs that have been rejected for transplantation. METHODS The donor lungs were reconditioned ex vivo in an extracorporeal membrane oxygenation (ECMO) circuit with STEEN solution (Vitrolife AB, Kungsbacka, Sweden) mixed with erythrocytes. The hyperoncotic solution dehydrates edematous lung tissue. Functional evaluations were performed with deoxygenated perfusate by varying the inspired fraction of oxygen. After the reconditioning, the lungs were kept immersed at 8 degrees C in extracorporeal membrane oxygenation until transplantation was performed. RESULTS Six of nine initially rejected donor lungs were reconditioned to acceptable function, and in six recipients, double lung transplantation was performed. Three-month survival was 100%. One patient has since died due to sepsis after 95 days, and one due to rejection after 9 months. Four recipients are alive and well without any sign of bronchiolitis obliterans syndrome 24 months after the transplantation. CONCLUSIONS The result from the present study is promising, and we continue to transplant reconditioned lungs.

The Appearance of S-100 Protein in Serum During and Immediately After Cardiopulmonary Bypass Surgery: A Possible Marker for Cerebral Injury

OBJECTIVE To investigate the appearance and elimination of brain-specific S-100 protein in serum during and immediately after cardiopulmonary bypass. DESIGN Prospective study. PARTICIPANTS Twenty-nine patients undergoing elective cardiac surgery. INTERVENTIONS Twenty-seven patients were operated on for coronary artery disease; two patients had valve replacement. Serial measurements of S-100 in arterial blood during and up to 48 hours after cardiopulmonary bypass were made. MEASUREMENTS AND MAIN RESULTS The perioperative and postoperative course was uneventful in 25 patients, with no clinical signs of neurologic complications. S-100 was not detected before extracorporeal circulation was started. Detectable concentrations (detection limit, 0.2 microgram/L) appeared in serum after 10 minutes of perfusion and reached maximum levels, 2.43 +/- 0.3 micrograms/L, at the end of bypass. The levels then declined with elimination t1/2 of 2.2 hours. Only two patients had detectable concentrations of S-100 48 hours after the end of bypass. In four patients who developed clinical signs of cerebral injury, levels of S-100 were significantly higher at the end of bypass and 24 hours after the end of bypass. CONCLUSIONS Cardiopulmonary bypass initiates a release of brain-specific S-100 to the systemic circulation. The release and elimination of S-100 seem to follow a reproducible pattern in patients with no signs of cerebral injury. In patients who developed cerebral injury, the concentrations of S-100 in blood were increased, thus suggesting that S-100 may be a usable marker for cerebral injury after extracorporeal circulation.

Neuron-specific enolase increases in plasma during and immediately after extracorporeal circulation

BACKGROUND Minor cerebral complications are common after cardiac surgery. Several biochemical markers for brain injury are under research; one of these is neuron-specific enolase (NSE). The purpose of this study was to investigate the release of this enzyme into the blood during and immediately after extracorporeal circulation and to evaluate the effect of hemolysis on this release. METHODS Sixteen patients scheduled for elective heart surgery were included in the study. Blood samples for analysis of NSE and free hemoglobin in plasma were drawn before, during, and up to 48 hours after the end of extracorporeal circulation. The release of NSE from erythrocytes and its correlation to the release of free hemoglobin was studied by serial dilution and hemolysis in vitro. RESULTS The peri- and postoperative course was uneventful in all patients. Extracorporeal circulation initiated a release of NSE that reached a maximum 6 hours after the end of perfusion. Thereafter, the levels declined with an estimated t1/2 of 30 hours. The concentration of free hemoglobin increased during the perfusion, with maximum levels at the end of perfusion, after which they fell rapidly to normal values. The in vitro study showed a strong linearity between the release of NSE and free hemoglobin after induced hemolysis. CONCLUSIONS The increased levels of enolase at the end of cardiopulmonary bypass can, to a major part, be explained by the release from hemolysed erythrocytes. The value of NSE as a marker for brain injury in these situations is therefore doubtful.

Increased S100B in blood after cardiac surgery is a powerful predictor of late mortality

BACKGROUND Long-term outcome in patients who suffered stroke after undergoing a cardiac operation has been investigated sparingly, but increased long-term mortality has been reported. S100B is a biochemical marker of brain cell ischemia and blood-brain barrier dysfunction. The aim of this investigation was to record the long-term mortality in consecutive patients undergoing cardiac operations and to explore whether increased concentrations of S100B in blood had a predictive value for mortality. METHODS Prospectively collected clinical variables, including S100B, in 767 patients who survived more than 30 days after a cardiac operation, were analyzed with actuarial survival analysis and 678 patients were analyzed with Cox multiple regression analysis. RESULTS Forty-nine patients (6.4%) were dead at follow-up (range, 18 to 42 months); 11.5% (88 of 767 patients) had elevated S100B 2 days after operation (range, 38 to 42 hours). The probability for death at follow-up was 0.239 if the S100B level was more than 0.3 microg/L, and 0.041 if it was less than 0.3 microg/L. The clinical variables independently associated with mortality were preoperative renal failure, preoperative low left ventricular ejection fraction, emergency operation, severe postoperative central nervous system complication, and elevated S100B values, which turned out to be the most powerful predictor. CONCLUSIONS Even slightly elevated S100B values in blood 2 days after cardiac operation imply a bad prognosis for outcome, and especially so in combination with any central nervous system complication.

Influence of Prosthesis-Patient Mismatch on Diastolic Heart Failure After Aortic Valve Replacement

BACKGROUND Bioprostheses for supraannular placement have been developed to optimize the hemodynamic performance after aortic valve replacement. To evaluate the potential benefit of this design, we analyzed the influence of prosthesis-patient mismatch on diastolic function and left ventricular mass regression and evaluated the clinical performance of the Sorin Soprano and Medtronic Mosaic in the aortic position. METHODS A total of 372 patients underwent aortic valve replacement between July 2004 and February 2007, receiving either a Sorin Soprano (n = 235) or a Medtronic Mosaic (n = 137) prosthetic valve. Echocardiographic and clinical data were collected prospectively, and follow-up was performed in April 2007. Multivariate analyses were used to identify differences in hemodynamic performance, diastolic function, left ventricular mass regression, and predictors of impaired survival. Kaplan-Meier survival curves and log-rank tests were used to compare postoperative outcomes. RESULTS The 30-day mortality was 1.7% (4 of 235 patients) in the Sorin Soprano group and 2.9% (4 of 137 patients) in the Medtronic Mosaic group (p = 0.473). Neither prosthesis-patient mismatch nor type of prosthesis was a significant predictor of early or late mortality. Diastolic heart failure was a predictor of poor survival (p = 0.004); however, the recovery of diastolic function was not significantly influenced by prosthesis-patient mismatch. Neither moderate (indexed effective orifice area < 0.85 cm(2)/m(2)) nor severe (indexed effective orifice area < 0.65 cm(2)/m(2)) prosthesis-patient mismatch resulted in a significantly impaired left ventricular mass regression. CONCLUSIONS Prosthesis-patient mismatch was not an independent predictor of poor survival, impaired left ventricular mass regression, or recovery of diastolic function. The Sorin Soprano and the Medtronic Mosaic bioprostheses demonstrated comparable hemodynamic performance and excellent clinical outcome without signs of structural valve deterioration during follow-up.

Blood transfusion after cardiac surgery: is it the patient or the transfusion that carries the risk?

Background: The transfusion of red blood cells (RBCs) after cardiac surgery has been associated with increased long‐term mortality. This study reexamines this hypothesis by including pre‐operative hemoglobin (Hb) levels and renal function in the analysis.

Bileaflet blood cysts on the mitral valve in an adult.

Blood cysts within the heart are very rare entities in adults. The authors present possibly the first ever case in which blood cysts were found on both mitral valve leaflets. A 65-year-old woman was referred for transthoracic echocardiography because of vague chest discomfort. Transthoracic echocardiography displayed echo-free cysts on the tips of both mitral valve leaflets. Subsequent transesophageal echocardiography confirmed this finding. The blood cysts were successfully surgically removed.

Perception of Mechanical Heart Valve Sounds

Most currently used mechanical heart valve prostheses generate a distinct sound when they close. This sound is sometimes disturbing to the patient, and may impair quality of life. In a study of 285 patients followed up for a mean of 2.5 years after mechanical heart valve replacement, one-third were sometimes disturbed by sounds emanating from the prosthesis. Older patients were less disturbed than young ones, but whether this could be explained by age-related impairment of hearing ability (presbyacusis) was not possible to determine. Prosthetic size, implantation site, patients weight, body surface area and type of prosthesis did not statistically differ according to experience of prosthetic sounds. Although few patients were seriously disturbed by these sounds, it is hoped that mechanical heart valves of the future will function more quietly.

Postoperative Autotransfusion of Concentrated Drainage Blood in Cardiac Surgery: Experience with a New Autotransfusion System

A new autotransfusion system was evaluated postoperatively in six patients undergoing aortocoronary bypass surgery. A hollow fiber hemofilter was integrated in the system, making it possible to concentrate the shed blood. The device functioned well, 825 ml diluted mediastinal drainage blood with a hematocrit of 23 was concentrated to a volume of 475 ml with a hematocrit of 36 and retransfused. Proteins were preserved, thus albumin concentration increased from 23 to 37 g/l in the autotransfusate. No negative side effects were registered after autotransfusion. A thorough coagulation study after retransfusion did not reveal any sign of activation of the coagulation cascade, nor were there any signs of an increased fibrinolysis.

Serious complications in connection with cardiac surgery—Next of kin's views on information and support

OBJECTIVE Next of kin (NoK) to patients undergoing cardiac surgery expect successful outcomes but sometimes serious complications occur and this affects their NoK. To describe NoKs experiences of information and support when serious complications occur during the first 30 days after cardiac surgery. METHODS A qualitative, critical incident technique was used. Forty-two NoK were asked to describe their experiences of information and support. RESULTS Three main areas emerged from the analysis. The first main area, Confidence during the waiting period, described how NoK could not participate in the forthcoming operation and how the NoK were informed. The second main area, Involvement during the hospital stay, described how the NoK feel trust in the healthcare professionals and dissatisfaction with the care in relation to the operation. The third main area, Sense of abandonment, described problems with the rehabilitation. CONCLUSIONS These findings show the importance of pre- and post operative contacts between healthcare professionals, patients and NoK. When the NoK and the patients are well informed it constitutes a basis for fruitful conversations between them and the healthcare professionals, and everyone can be better prepared if complications occur.