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.

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.

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.

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.

Diagnostic transaortic cardioscopy of the left ventricle.

Preoperative diagnosis of pathologic intracardiac structures by noninvasive techniques is sometimes difficult or even impossible. In these cases a heart operation is required with opening of one or more cardiac chambers. We demonstrate direct visualization of the left ventricular cavity by transaortic cardioscopy in a patient with a pathologic intraventricular structure. With this technique we could avoid ventriculotomy.

Repair of an aneurysm of the pulmonary trunk in a 65-year-old patient.

The case of a 65-year-old patient with asymptomaticaneurysm of the pulmonary trunk associated with severe insufficiency of the pulmonary valve and symptomatic coronary artery disease is presented. The surgical procedure included coronary artery bypass grafting, aneurysmectomy, and pulmonary artery replacement with implantation of a stentless bioprosthesis and lengthening of the root of the bioprosthesis with a reversed vascular Y prosthesis, which was anastomosed to the left and right pulmonary artery.

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.

Video-assisted resection of hypertrophied and fibrous intraventricular tissue.

There is increasing interest in endoscopic techniques in cardiac surgery. However, use of the endoscope during open heart operations is still not routine. Cardioscopy has been used in patients with hypertrophied obstructive cardiomyopathy, asymmetric septal hypertrophy, or membranous subaortic stenosis. We demonstrate the resection of this pathologic tissue under direct visualization. With this technique we could increase the safety and accuracy of this surgical procedure. Beside this advantage, the entire operating room staff could follow the surgical intervention, which increases its educational side-effect.

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.

Ten years experience with povidone-iodine in heart surgery.

Ten years experience with povidone-iodine (PVP-I) (10%) ('Beta-isodona') in 7566 patients undergoing open-heart operations in the German Heart Centre, Munich, is reported. Povidone-iodine was used pre-, intra- and postoperatively for skin and wound disinfection according to a regime introduced more than 10 years ago and retained unchanged until today. The incidence of minor, superficial wound healing defects was 5%, whereas severe, deep sternal or retrosternal infections occurred in 0.5% of all patients. Superficial infections are no risk to the patient and can be treated successfully with local application of PVP-I. Deep infections, however, are associated with a mortality of about 40% despite the use of antibiotics and continuous wound irrigation with PVP-I (0.5%). Many factors contribute to the risk of these infections and only meticulous observation of aseptic and surgical technique, the prophylactic and therapeutic use of highly effective antibiotics, as well as the exclusion of sources of exogenous bacteria, can further reduce the incidence of these complications.

Reoperations after dacron patch aortoplasty with heparinized femoro-femoral bypass.

Dacron patch aortoplasty used to be a standard therapy in some surgical units. Occurrence of aneurysm formation after this procedure is well known. The incidence of aneurysms is reported to be 0-35% with a high risk of lethal rupture. We report three cases of aneurysm repair of the descending thoracic aorta after dacron patch aortoplasty using femoro-femoral extracorporeal system. Heparin-coated system was used primarily to prevent ischemic spinal cord injury through hypotension of the distal aorta and secondarily to reduce the risk of intraoperative hemorrhage.

Midterm results after the Mini-Maze procedure.

OBJECTIVE: Atrial fibrillation (AF) is the most common arrhythmia. However, its precise electrophysiologic mechanism is still not well understood. Chronic symptomatic AF resistant to medical therapy, can successfully be treated by the Maze III procedure (M III). However, there are several publications dealing with alternative surgical techniques. This study describes technique and midterm results of a Mini-variant of the M III procedure. METHODS: During a 38-month period we performed either an M III (seven patients) (group I) or a MINI-operation (45 patients) (group II) with chronic symptomatic AF and additional cardiac pathology. Patients were controlled 3.6 +/- 0.9 and 14.9 +/- 2.2 months after operation by means of thorough electrophysiological assessment, right heart catheterization, magnetic resonance imaging (MRI), echocardiography, stress-EGG and 24-h-ECG. RESULTS: There was no significant differences 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 67 +/- 8 mm in group II (P = 0.01). Whereas right atrial diameter was 62 +/- 8 mm in group I and 56 +/- 7 mm in group II (NS). Perioperative data (n = 52): aortic cross clamp time was 127 +/- 40 mm in group I and 87 +/- 21 mm in group II, (P = 0.0002). Cardiopulmonary bypass time was 185 +/- 71 mm in group I and 137 +/- 46 mm in group II, (P = 0.02). Postoperative data: there was no difference between the two groups with regard to sinus rhythm, prolonged sinus node recovery time, pacemaker (PM) in AAI-mode, inducible atrial fibrillation, reduction of left and right atrial size after a follow-up interval of 3.6 months and 1 year, respectively. CONCLUSION: Midterm results are identical after M III and MINI. MINI is less complex compared to the M III procedure and there is a significant reduction of crossclamp- and ECC-time. We recommend the MINI especially for polymorbid patients, and for those with poor left ventricular function.

Cardioscopy: potential applications and benefit in cardiac surgery.

OBJECTIVE: Cardioscopy in open heart surgery is still not routine in most units. However, since our first report in 1996 we use this device more frequently, because we think that safety and accuracy of different surgical procedures is increased. METHODS: Between 1/96 and 12/97 we performed cardioscopy in 100 patients. Indications (IND) for cardioscopy were as follows: IND (1) resection of hypertrophied septum (N = 15); IND (2) evaluation of aortic valve with low grade stenosis or insufficiency (N = 12); IND (3) removal of intracardiac foreign bodies/tumors (N = 13); IND (4) inspection of VSD prior and after repair (N = 8); IND (5) identification of paravalvular leakage (N = 8); IND (6) diagnostic purposes (N = 4); IND (7) education of surgeons and operating room staff (N = 40). During cardioplegic arrest the 5 mm rigid or flexible cardioscope (Storz, Tuttlingen, Germany) was inserted through ascending aorta, aortic valve or tricuspid valve depending on indication. RESULTS: No complication occurred during cardioscopy. IND (1): there was an excellent view of all intracardiac structures. Thorough resection of hypertrophied septum was possible and there was no injury of adjacent structures or aortic valve. IND (2): all valves were inspected through a 1 cm aortic incision and the pathology of the valves was documented. In case of severe calcification, the valve was replaced although transvalvular gradient was less than 50 mm Hg. IND (3): intraventricular foreign bodies, such as felt pledges (N = 2), debris (N = 5), thrombi (N = 4) and tumors (N = 2) were entirely removed through the aortic valve with a special forceps. IND (4): anatomy of VSD was documented in all cases. It was possible to test accuracy of all patch-sutures. IND (5): all paravalvular leakages were identified even though there was heavy immobility of the mechanical valve. IND (6): a papillary muscle (N = 2) and a thrombus formation (N = 2) were diagnosed. IND (7): the surgeons and operating room staff could follow the entire procedure in all cases. CONCLUSIONS: Cardioscopy is a supporting technique to clearly identify intracardiac structures, to control several surgical procedures, to document valve pathology, and to educate surgeons and operating room staff. Handling is easy and does not increase operative risk. Some procedures will be performed with minimal invasivity in future.

Transmyocardial laser revascularisation has no beneficial effect on high energy phosphates and lactate content during acute myocardial ischaemia in pigs.

OBJECTIVE: Transmyocardial laser revascularisation (TMLR) is used to treat endstage coronary heart disease. There is evidence that angina is significantly reduced after TMLR. However, the precise mechanism by which symptoms disappear remains unknown. The objective of the present study was to examine the potential effects of TMLR on high-energy phosphates and myocardial perfusion in an acute ischaemic model. METHOD: Five male landrace pigs (42 +/- 1.8 kg) had TMLR of the anterolateral wall of the left ventricle using a 1000 W CO2 laser (PLC, USA). Thereafter the anterior descending coronary artery was occluded with a tourniquet. After 90 min of ischaemia, drill-biopsies were taken from ischaemic and non-ischaemic areas as well as from laser channels. The specimens were snap-frozen in liquid nitrogen. Subsequently, methylene blue was injected into the left atrium to study tissue distribution. The hearts were excised and the patency of channels was examined visually. RESULTS: Coronary artery occlusion resulted in immediate blue discoloration in both TMLR and control areas. There was no subendocardial methylene blue staining around laser channels. Inspection of hearts showed occlusion of laser channels due to thrombus formation at both endo- and epicardial levels. ATP-metabolites significantly increased in ischaemic areas compared to non-ischaemic areas. Furthermore there was significant upregulation of purine-content in ischaemic regions even in areas with laser channels. CONCLUSIONS: In our acute model there was early occlusion of the channels after TMLR. We suggest that clinical improvement after this procedure is not due to increased myocardial oxygen delivery, since high energy phosphate levels and lactate content remained unchanged.

Valve surgery combined with coronary artery operation: is the use of internal mammary artery a predictor for early complications?

The internal mammary artery (IMA) provides better early and long-term patency than venous grafts do. Although IMA is the conduit of choice in isolated coronary artery bypass grafting (CABG), its use in combined procedures is not routine in some cardiovascular units. During a 16-month period, 188 patients underwent valve surgery combined with CABG. Internal mammary grafts were used in 68/188 (36%) patients (group 1) and vein grafts without arterial grafts (group 2) in 120/188 (64%). Left IMA was implanted in 67/68 (99%) and right IMA in 1/68 1%) cases. Surgeon A used IMA in 28/44 (64%), surgeon B in 20/32 (63%), surgeon C in 18/44 (41%), surgeon D in 1/4 (25%) and surgeon E in 1/63 (2%) patients. The final decision to use IMA in a combined procedure was left up to the surgeon. Statistically, the preoperative- and perioperative data were identical in the two groups, although the frequency of IMA grafting in patients with double valve replacement and reoperation was lower (1/68 vs 11/120, ns, and 3/68 vs 9/120, ns). Ten of 188 (5.3%) patients died within 30 days after operation. Longer cross-clamp time (P = 0.008) and mitral valve replacement (P = 0.05) were independent risk factors for early death. The use of IMA did not increase the risk of early mortality. The postoperative variables were similar in the IMA and vein groups, in particular data suggesting perioperative myocardial infarction (CK-MB, catecholamine support). Postoperative mechanical ventilation was longer in the IMA group, although not significantly (P = 0.06). Early mortality and morbidity were identical in the two groups in combined procedures. We did not find any hints for an increased risk of using IMA in this type of surgery. Internal mammary artery implantation is safe in selected patients undergoing combined valve and CABG surgery. Beside the better long-term patency of IMA, its use may have several technical advantages.

Myocardial preservation using HTK solution for heart transplantation. A multicenter study.

Bretschneider HTK solution is commonly used for myocardial preservation. In order to evaluate its protective effect for heart transplantation, a retrospective study was initiated in cooperation with Eurotransplant and five heart transplant centers. Seventy-six female and 524 male patients who underwent cardiac transplantations between 1981 and 1991 were included in this study. Using standardized questionnaires, donor and recipient laboratory data, immunosuppressive therapy and the preoperative, intraoperative and postoperative organ function were documented. The average ischemic time of the donor hearts was 160 min, ranging from 75 min-304 min. Immediate postoperative graft failure was observed in 25 transplantations (4.2%). Within the first 30 days 71 organs (11.8%) failed. Using the chi2-test, a statistically significant increase of acute graft failure and early mortality was evident when they were correlated with the length of ischemic time (P = 0.01). In addition, a higher incidence of early graft failure was observed when the perfusion volume was less than 1500 ml. The 1- and 5-year survival rates were 72% and 63%, respectively. Organ preservation with HTK shows good results as long as the ischemic time does not exceed 4 h. The possibility that an increased perfusion volume allows longer ischemic times cannot be excluded with this study.

A dynamic bubble trap reduces microbubbles during cardiopulmonary bypass: a case study.

Microemboli passing to the cerebral circulation during cardiopulmonary bypass can contribute to postoperative neurologic dysfunction. Many studies conclude that air microbubbles predominantly are responsible for this problem. A dynamic bubble trap (DBT) was developed to diminish the number of microbubbles in the arterial line of extracorporeal circulation. The DBT is able to substantially reduce the number of air microbubbles, as shown in two patients undergoing coronary artery bypass grafting, where a high number of microbubbles was assessed. Although a 40-micron arterial filter was used, many bubbles larger than 40 microns occurred in the arterial line. The DBT reduced the number of large microbubbles from 2,267 to 67 in patient 1 and from 897 to 61 in patient 2.