Reduction of gaseous microembolism during aortic valve replacement using a dynamic bubble trap.

Serious postoperative psycho-neurological dysfunction is at least partially attributed to the occurrence of gaseous microbubbles in the arterial line of extracorporeal circulation (ECC). Therefore, we investigated in a prospective randomized double blind study whether the usage of dynamic bubble trap (DBT) will reduce microbubble load of patients undergoing aortic valve replacement. Patients (n = 41) were divided into group I (GI, n = 22) with DBT introduced into the arterial line of ECC and group II (GII, n = 19) with placebo-DBT instead. Doppler ultrasonography was used for detection of microbubbles before and after DBT, and for detection of high intensity transient signals (HITS) within the middle cerebral artery. The recording time during ECC was divided into period 1 (P1, until aortic clamp removal) and period 2 (P2, clamp removal until the end of ECC). A significant reduction of microbubble load was found in GI only (p < 0.0001 for ECC; p < 0.0001 for P1; p < 0.0025 for P2). A significant difference in number of HITS between the groups was observed in P1 only (p < 0.002 left middle cerebral artery, p < 0.005 right middle cerebral artery), since in P2 the trapped air in left chamber can go to the supraaortal vessels without passing ECC. In conclusion the use of DBT cannot substitute careful venting after aortic declamping. Nevertheless, reduction of HITS in the cross-clamped period of ECC justifies the use of DBT in patients undergoing open chamber surgery.

Trapidil decreases the aggregation of platelets from heart transplant recipients ex vivo.

Heart transplant recipients show platelet hyperaggregability, which may be related to the incidence of graft vasculopathy. We investigated whether trapidil can inhibit the aggregation of platelets from these patients. Platelet count, mean platelet volume (MPV), and adenosine diphosphate (ADP)-induced platelet aggregation were determined in 18 heart transplant recipients and 12 healthy subjects. Additionally, platelet-rich plasma from the patients was incubated with trapidil or with saline, prior to measuring ADP-induced aggregation. The MPV was significantly greater in patients compared to controls (9.4+/-1.1 vs 8.5+/-0.7 fL; P=.01), and ADP-induced platelet aggregation was significantly increased in patients compared to controls (81.2%+/-13.1% vs 69.6%+/-16.2%; P=.04, respectively). The trapidil-treated samples showed significantly decreased platelet aggregation compared to the control samples (24.2%+/-12.6% vs 66.7%+/-11.7%; P<.001). Platelets from heart transplant recipients showed an increased MPV and increased ADP-induced aggregation. Trapidil effectively reduced the ADP-induced aggregation ex vivo.

Non-aneurysmal inflammation of the aorta in combination with aortic valve disease.

A 61-year-old man presented with aortic valve stenosis, coronary artery disease in combination with rheumatic arthritis, peri-aortic inflammation and fibrosis with aortitis. In the pathological literature this has been termed chronic periaortitis, while in the surgical literature, non-aneurysmal dilatation of the aorta associated with atherosclerosis and inflammation has been described as aortitis. The name chronic periarteritis refers to the associated involvement of coronary arteries. Although different terminologies have been used, it is suggested that all of them most likely represent the same disease entity.

Atrial fibrillation at discharge from the hospital in patients undergoing mitral valve repair.

BACKGROUND: Patients undergoing mitral valve repair (MVRr) are often discharged on oral anticoagulation with warfarin. Because the decision about oral anticoagulation is made at discharge from the hospital and because atrial fibrillation (AF) represents the only well-documented indication for oral anticoagulation in these patients, we studied the frequency of AF at discharge after MVRr. METHODS: We reviewed the records of 245 patients who underwent MVRr over the past 5 years and assessed the frequency of AF at discharge from the hospital and the factors that were associated with an increased risk for arrhythmia. RESULTS: The group comprised 95 women and 150 men with a mean age of 62.1 +/- 14 years. Seventy-three (30 %) patients were in and/or had a history of AF on admission. Sixty-five (27 %) patients had AF at discharge. Factors that were associated with AF at discharge were: AF on admission (odds ratio [OR] 57.1; confidence interval [CI] 20.8 - 157.3; p < 0.0001), enlarged left atrium (OR 3.2; CI 1.2 - 8.7; p = 0.025) and intake of ACE inhibitors (OR 3.9; CI 1.2 - 12.3; p = 0.022). The OR for AF at discharge in patients with none of the above risk factors was 0.02 (95 % CI 0.02 - 0.13; p < 0.0001). CONCLUSION: Only a relatively small proportion of the studied patients, especially patients with AF on admission, with larger atria and with a history of ACE inhibitors intake, were in AF at discharge after MVRr. Patients with none of these risk factors were at low risk for AF at discharge after MVRr and the optimal oral anticoagulation regimen for these low-risk patients needs to be determined.

Leukocyte-depleted secondary blood cardioplegia attenuates reperfusion injury after myocardial ischemia.

BACKGROUND: Activated neutrophils have been implicated in reperfusion injury of the myocardium; leukocyte depletion at the time of reperfusion may contribute to better myocardial protection after cardiac surgery. In the present study, we examined whether leukocyte depletion as an adjunct to terminal blood cardioplegia attenuates reperfusion injury. METHODS: Porcine hearts that had undergone 60 minutes of normothermic ischemia with cardioplegia and 60 minutes of reperfusion under cardiopulmonary bypass were divided into four groups according to the methods of 15 min of controlled initial reperfusion: whole blood reperfusion (n = 6), leukocyte-depleted reperfusion (n = 6), secondary blood cardioplegia (n = 6) and leukocyte-depleted secondary blood cardioplegia (n = 6). At 60 min of reperfusion, hemodynamic recovery, release of malondialdehyde (MDA) as a marker for free oxygen radicals, CK-MB-isoenzyme from the coronary sinus, recovery of adenosine triphosphate, and myocardial water content were evaluated. RESULTS: The group with leukocyte-depleted secondary blood cardioplegia showed the best hemodynamic recovery (Emax and total dp/dt), lowest levels of MDA, CK-MB and myocardial water content, and highest adenosine triphosphate recovery. CONCLUSIONS: These results suggest that controlled reperfusion with leukocyte-depleted secondary blood cardioplegia attenuated severe damage of the myocardium as compared to whole blood reperfusion.

INR self-management permits lower anticoagulation levels after mechanical heart valve replacement.

BACKGROUND: The Early Self Controlled Anticoagulation Trial (ESCAT I) showed that anticoagulation self-management after mechanical heart valve replacement decreased complication rates by maintaining INR levels closer to the target range than International Normalized Ratio (INR) home doctor management. The therapeutic range for the INR in that study was between 2.5 and 4.5 for all positions of prosthetic valves. ESCAT II should find out whether lowering the target range for INR self-management would further reduce complication rates. METHODS: ESCAT II is a prospective controlled randomized (valves: St. Jude Medical Standard or Medtronic Hall, treatment: conventional/low-dose) multicenter study with 3,300 patients. We present interim results of 1,818 patients. 908 were categorized as having a low-dose target range, which was INR 1.8 to 2.8 for prostheses in aortic position and 2.5 to 3.5 for prostheses in mitral position or in combined valve replacement. The control group (conventional group) with 910 patients aimed at an INR of 2.5 to 4.5 for all valve positions. RESULTS: In the conventional group, 74% of INR values measured were within the therapeutic range. In the low-dose group, 72% of the values were within that range. The linearized thromboembolism rate (% per patient year) was 0.21% for both groups. The bleeding complication rate was 0.56% in the low-dose regimen group versus 0.91% in the conventional group. CONCLUSIONS: Early onset INR self-management under oral anticoagulation after mechanical heart valve replacement enables patients to keep within a lower and smaller INR target range. The reduced anticoagulation level resulted in fewer grade III bleeding complications without increasing thromboembolic event rates.

Contrast-echocardiography: confirmation of patency of laser channels after transmyocardial laser revascularization.

AIMS: Apart from casuistic autopsy results there is no long-term evidence for channel perfusion after transmyocardial laser revascularization in humans. METHODS AND RESULTS: Fifteen consecutive patients aged 63+/-17 years were investigated 71+/-15 days after coronary artery bypass surgery and/or transmyocardial revascularization with 13-37 (20+/-5) channels (CO(2) laser, 40 J/pulse). Echocardiography was performed after injection of 6 ml echo contrast medium into left ventricular cavity and after injection of 3 ml contrast medium into the left main coronary artery. In five patients with additional bypass surgery to the same region, we also injected 3 ml contrast medium into bypass graft. We could prove in 10 of 15 patients (67%) one or two laser channels in the apical left ventricular myocardium. Channels were perfused exclusively during systole. During following heart cycles myocardium was opacified up to a mean width of 1.4+/-0.4 cm, a mean depth of 0.71+/-0.1cm, and a mean area of 1.0+/-0.6 cm(2). Contrast medium was washed out via coronary venous system in 9+/-8 systoles. CONCLUSION: This is the first clinical evidence of long-term laser-channel patency in humans showing perfused myocardium via left ventricular cavity.

Predictors for atrial transport function after mini-maze operation.

BACKGROUND: Restoration of atrial transport function (ATF) is a major goal of the maze procedure. This prospective study was undertaken to evaluate predictors of left atrial transport function in patients undergoing a mini-variant of the maze III procedure 3 and 12 months postoperatively. METHODS: Mini-maze operation was performed in 72 patients with a mean age of 64 +/- 8.7 years during a 5-year period. Seventy of 72 (97%) had combined procedures. Clinical and electrophysiologic examination was carried out before surgery, and 3 and 12 months postoperatively. RESULTS: Early mortality was 1.4% (1 of 72 patients) and late death occurred in 5.6% (4 of 71 patients). After 3 months, 54 of 68 (80%) patients showed sinus rhythm, and 48 of 60 (80%) after 12 months. ATF was restored in 87% (echocardiography) and 82% (magnetic resonance imaging) after 3 months, and in 86% (echocardiography) and 78% (magnetic resonance imaging) after 12 months. Independent predictors for ATF restoration after 12 months were better preoperative left ventricular function (p = 0.02), and smaller preoperative left atrial diameter (p = 0.005). Correlation between echocardiography and magnetic resonance imaging was 80% after 12 months. CONCLUSIONS: Restoration of ATF after mini-maze procedure is achieved in over 80%. Independent predictors for ATF restoration are smaller preoperative left atrial diameter and better preoperative left ventricular ejection fraction.

Ruptured papillary muscle after mitral valve replacement with preservation of chordae tendineae.

Many cardiac surgeons believe strongly that every effort should be made to preserve the continuity of the mitral anulus, chordae tendineae, and papillary muscles during mitral valve replacement in order to maximize ventricular function and maintain normal ventricular geometry. We treated a patient with spontaneous papillary muscle rupture after mitral valve replacement in whom efforts had been made to preserve continuity of the mitral mechanism.

[Papillary muscle rupture after mitral valve replacement with preservation of subvalvular structures]. / Papillarmuskelruptur nach Mitralklappenersatz mit erhaltenem subvalvulärem Apparat.

We report a female patient with mitral valve replacement and preservation of subvalvular apparatus in which parts of the papillary muscle ruptured postoperatively. During systole the ruptured papillary muscle prolapsed through the native aortic valve. Echocardiographic documentation and operative procedure were demonstrated.

Peripheral arterial embolism originating from a thrombus in the ascending aorta.

A 45-year-old man experienced arterial thromboembolism to the right leg requiring surgical restoration of blood flow. Transesophageal echocardiography (TEE) was performed to determine the source of embolism and identified a localized atherosclerotic lesion in the distal ascending aorta with an adherent, highly mobile thrombus. The patient underwent surgery with removal of the atherosclerotic plaque and attached thrombus, and resection of the adjacent aortic wall. This case illustrates an unusual location for a complex atherosclerotic lesion in the ascending aorta, and points out the opportunity for remedial surgery once a symptomatic embolus has occurred.

Significant reduction of air microbubbles with the dynamic bubble trap during cardiopulmonary bypass.

Air microbubbles mostly occur unnoticed during cardiopulmonary bypass and are predominantly responsible for serious postoperative psychoneurological dysfunction. A dynamic bubble trap (DBT), which removes air microbubbles from the arterial blood, was tested in a clinical study. The aim was to evaluate the efficiency of microbubble removal under clinical conditions. As blood passes through the DBT, which is placed in the arterial line between the arterial filter and arterial cannula, it is converted into a rotating stream. The bubbles are directed to the centre of the blood flow and are collected in the distal end of the DBT, from where they are returned to the cardiotomy reservoir. Doppler ultrasonography was used to detect the microbubbles before and after the DBT, and also the number of high-intensity transient signals (HITS) in the right and left middle cerebral artery during extracorporeal circulation. A significant reduction of microbubbles in the arterial line (3,990 before DBT, 537 after, p < 0.001) and HITS in the brain (51 in the DBT group, 77 in the placebo group, p = 0.04) was measured.

A self-perpetuating vicious cycle of tissue damage in human hibernating myocardium.

Recently, we proposed the hypothesis that a vicious cycle exists in human hibernating myocardium (HM) between the progression of myocyte degeneration and the development of fibrosis. We now investigated the pathomechanism of this cycle in more detail and established a correlation between the severity of the morphological changes and the degree of postoperative functional recovery of HM. HM was diagnosed by dobutamine echocardiography, thallium-201 scintigraphy and radionuclide ventriculography. Functional recovery was present at 3 months after coronary bypass surgery but remained unchanged at 15 months. Forty patients were subdivided into 2 groups: A with complete and B with incomplete recovery. Biopsies taken during surgery and studied by electron microscopy, immunocytochemistry, rt-PCR, and morphometry revealed myocyte degeneration and inflammatory and fibrinogenic changes in a widened interstitial space. We report here for the first time an upregulation of TGF-beta1 evident by a 5-fold increase of fibroblasts and macrophages exhibiting a TGF-beta1 content 3-fold larger than in control, and a > 3-fold increase in TGF-beta1 mRNAby rt-PCR. The number of angiotensin converting enzyme (ACE) containing structures was increased (n/mrm2: control-11.4, A-17.6, B-19.2, control vs. A and B, p < 0.05). Fibrosis was more severe in group B than A or control (%: C-10.1; A-21.2; B-40.6; p < 0.05). Capillary density was significantly reduced (n/mm2: C-1152; A-782; B-579, p < 0.05) and intercapillary distance was widened (microm: C-29.5, A-36.1, B-43.3, p < 0.05). The number of CD 3 (n/mm2: C-5.0; A-9.6; B-9.4, ns) and CD 68 positive cells (n/mm2: C-37.2; A-80.7; B-55.0, C vs. A p < 0.05) was elevated in HM as compared to control indicating an inflammatory reaction. Cut-off points for functional recovery are fibrosis > 32%, capillary density < 660/mm2 and intercapillary distance > 39.0 microm. In HM a self-perpetuating vicious cycle of tissue alterations leads to progressive replacement fibrosis and continuous intracellular degeneration which should be interrupted by early revascularization.

The effect of leukocyte-depleted blood cardioplegia in patients with severe left ventricular dysfunction: a randomized, double-blind study.

BACKGROUND: The propensity for leukocytes to cause reperfusion injury in patients undergoing heart surgery is widely accepted. Reperfusion injury may result in myocardial damage and unfavorable operative outcome, especially in patients with severely reduced ejection fractions. This study was performed to evaluate the impact of leukocyte filtration on the postoperative course of patients undergoing coronary bypass surgery. METHODS: Thirty-two patients with coronary artery disease and left ventricular ejection fraction less than 35% were included in this double-blind, randomized study. Two serial leukocyte removal filters (Pall BC1B filter [Pall Biomedical, Portsmouth, England], group F, 15 patients) or two dummy filters (group C, 17 patients) were connected to the blood cardioplegia line. Leukocyte count, hemodynamic measurement, and transesophageal echocardiography were performed before and after cardiopulmonary bypass. Cardiac-specific enzymes were analyzed from arterial blood during the first 72 hours and from coronary sinus blood 30 and 60 minutes after aortic unclamping. RESULTS: Patient characteristics were similar in the two groups (ejection fraction 20.9% +/- 4.3% in group C and 21.1% +/- 4.8% in group F; P =.773). No early death or perioperative myocardial infarction occurred. Leukocyte count, hemodynamic parameters, cardiac troponin T, cardiac troponin I, and creatine kinase MB mass levels in arterial blood were similar in the two groups. Group F showed lower release of cardiac troponin T from the coronary sinus 30 minutes after unclamping of the aorta (group F, 0.263 +/- 0.12 ng/mL; group C, 0.6 +/- 0.32 ng/mL; P =.005). Lower doses of dopamine were necessary after cardiopulmonary bypass (group F, 0.36 +/- 0.11 mg x kg(-1) x min(-1); group C, 0.49 +/- 0.14 mg x kg(-1) x min(-1); P =.003). A moderate increase in ejection fraction was observed at 30 minutes in both groups (group F, 30.3% +/- 6.2%; group C, 28.0% +/- 6.3%; P =.239) and a significant increase at 60 minutes in group F (group F, 32.5% +/- 6.0%; group C, 27.4% +/- 7.5%; P =.012). CONCLUSIONS: These results indicate that serial leukocyte filters connected to the blood cardioplegia line decrease myocardial cell injury and may therefore help to improve outcome of patients with severely depressed ejection fractions undergoing coronary artery bypass grafting.

[Symptomatic true aneurysm of a venous bypass with compression of the right atrium]. / Symptomatisches echtes Aneurysma eines Venenbypass mit Kompression des rechten Vorhofes.

A symptomatic true aneurysm of a saphenous vein graft to the right coronary artery in a female patient twelve years after bypass surgery is presented. Beating heart surgery included resection of the aneurysmatic saphenous vein graft, reconstruction of the right atrium and coronary artery bypass grafting to the right coronary artery. The symptoms of aneurysms of vein grafts, the diagnostic procedures and the surgical treatment are discussed.

Increased expression of cytoskeletal, linkage, and extracellular proteins in failing human myocardium.

Experimental studies have shown that in hypertrophy and heart failure, accumulation of microtubules occurs that impedes sarcomere motion and contributes to decreased ventricular compliance. We tested the hypothesis that these changes are present in the failing human heart and that an entire complex of structural components, including cytoskeletal, linkage, and extracellular proteins, are involved in causing functional deterioration. In explanted human hearts failing because of dilated cardiomyopathy (ejection fraction

[The maze operation--surgical therapy of chronic atrial fibrillation: modification to mini-maze operation]. / Die Mazeoperation--chirurgische Therapie bei chronischem Vorhofflimmern: Modifikation zur Minimazeoperation.

OBJECTIVE: Atrial fibrillation (AF) is the most common arrhythmia. However, its precise electrophysiologic mechanism is still not well understood. Chronic symptomatic atrial fibrillation resistant to medical therapy can successfully be treated by the Maze III procedure (M III). Several publications are dealing with alternative surgical techniques. This study describes technique and midterm results of a Mini-variant (Mini) of the Maze III procedure. METHODS: During a 48-month period we performed either a M III (group I = 7 patients) or a Mini-Maze operation (group II = 65 patients) in 33 males and 39 females with chronic symptomatic atrial fibrillation and additional cardiac pathology. Patients were controlled 4.0 +/- 1.8 months (group I) respectively 3.6 +/- 0.8 months (group II) (NS) and 16.75 +/- 2.5 months (group I) respectively 13.2 +/- 1.9 months (group II) (NS) after operation by means of thorough electrophysiological assessment, right heart catheterization, MRI, echocardiography, stress-ECG and 24 h-ECG. RESULTS: There was no significant difference between the two groups with regard to sex, age and duration of AF. Echocardiographic left atrial diameter (LAD) was 75 +/- 11 mm in group I and 65 +/- 8 mm in group II (p = 0.002). Whereas right atrial diameter was 62 +/- 8 mm in group I and 57 +/- 7 mm in group II (NS). Perioperative data (n = 72): Aortic cross clamp time was 127 +/- 40 min in group I and 87 +/- 22 min in group II (p = 0.0002). Cardiopulmonary bypass time was 185 +/- 71 min in group I and 137 +/- 42 min in group II (p = 0.01). Postoperative data I (first follow-up: n = 66): sinus rhythm (yes): 4/7 vs. 47/59 (NS); pacemaker (PM) in AAI mode (yes): 1/7 vs. 3/59 (NS); inducible atrial fibrillation (yes): 2/7 vs. 5/59 (NS); Bradycardie Tachycardie Syndrome with the need of PM implantation 0/7 vs. 4/59 (NS). Postoperative data II (second follow-up: n = 55): sinus rhythm (yes): 5/7 vs. 34/48 (NS); PM in AAI mode (yes): 0/7 vs. 4/48 (NS); Inducible atrial fibrillation (yes): 2/7 vs. 5/48 (NS); Bradycardia Tachycardia Syndrome with the need of PM Implantation 0/7 vs. 5/48. CONCLUSION: Midterm results are identical after M III and Mini. The Mini-Maze procedure is less complex compared to the Maze III procedure and there is a significant reduction of crossclamp and ECC times. We recommend the Mini especially for polymorbid patients and for those with poor left ventricular function.