Bioactive adrenomedullin (bio-ADM) is associated with endothelial dysfunction in infants and children with complex congenital heart disease undergoing open-heart surgery on cardiopulmonary bypass.

OBJECTIVES: Children with congenital heart disease (CHD) undergoing cardiac surgery on cardiopulmonary bypass (CPB) are at risk for systemic inflammation leading to endothelial dysfunction associated with increased morbidity. Bioactive adrenomedullin (bio-ADM) is a peptide regulating vascular tone and endothelial permeability. The aim of this study was to evaluate the dynamics of plasma bio-ADM in this patient cohort and its role in capillary leak. METHODS: Plasma samples from 73 pediatric CHD patients were collected for bio-ADM measurement at five different timepoints (TP) in the pre-, intra-, and post-operative period. The primary endpoint was a net increase in bio-ADM levels after surgery on CPB. Secondary endpoints included association of bio-ADM levels with clinical signs for endothelial dysfunction. RESULTS: Bio-ADM levels increased after surgery on CPB from pre-operative median of 12 pg/mL (IQR [interquartile range] 12.0-14.8 pg/mL) to a maximum post-operative median of 48.8 pg/mL (IQR 34.5-69.6 pg/mL, p<0.001). Bio-ADM concentrations correlated positively with post-operative volume balance, (r=0.341; p=0.005), increased demand for vasoactive medication (duration: r=0.415; p<0.001; quantity: TP3: r=0.415, p<0.001; TP4: r=0.414, p<0.001), and hydrocortisone treatment for vasoplegia (bio-ADM median [IQR]:129.1 [55.4-139.2] pg/mL vs. 37.9 [25.2-64.6] pg/mL; p=0.034). Patients who required pleural effusion drainage revealed higher bio-ADM levels compared to those who did not (median [IQR]: 66.4 [55.4-90.9] pg/mL vs. 40.2 [28.2-57.0] pg/mL; p<0.001). CONCLUSIONS: Bio-ADM is elevated in children after cardiac surgery and higher levels correlate with clinical signs of capillary leakage. The peptide should be considered as biomarker for endothelial dysfunction and as potential therapeutic target in this indication.

Effects of a dual-filter-based cerebral embolic protection device in transcatheter aortic valve replacement on cerebral oxygen saturation: A prospective pilot study.

PURPOSE: The Sentinel Cerebral Protection System (Sentinel-CPS) is increasingly used in transcatheter aortic valve replacement (TAVR). However, the impact of inserting the Sentinel-CPS inside the brain-supplying arteries on cerebral perfusion and oxygenation is unknown. METHODS: Twenty patients undergoing transfemoral TAVR with (n = 10) and without (n = 10) cerebral embolic protection using the Sentinel-CPS were prospectively observed. All patients received conscious sedation and cerebral oxygen saturation (rSO2 ) was continuously measured with near-infrared spectroscopy (NIRS). The cumulative perioperative cerebral desaturation was calculated for each patient by multiplying rSO2 below an individualized desaturation threshold by time. In addition, rSO2 values at the time of Sentinel-CPS insertion, filter positioning, and device retraction were analyzed. RESULTS: There was no significant difference in cumulative cerebral desaturation in patients with Sentinel-CPS (median [IQR]) (0 [0/81] s%) and without (median [IQR]) (0 [0/23] s%), p = .762. A total of 6 patients (33.3%) experienced a perioperative decrease in rSO2 below the individualized desaturation threshold (n = 3 with Sentinel-CPS, n = 3 without Sentinel-CPS; p = 1.000). Cerebral desaturation was detected during valve deployment (n = 5) and after postdilatation (n = 1). No desaturation events occurred during Sentinel-CPS insertion, filter positioning, or retraction. CONCLUSION: Our pilot study revealed no difference in cumulative perioperative cerebral desaturation between TAVR with and without Sentinel-CPS. Catheter- and filter-based manipulations in the brain-supplying arteries for Sentinel-CPS application were not associated with a decrease of cerebral perfusion and oxygenation.

Assessing the level of radiation experienced by anesthesiologists during transfemoral Transcatheter Aortic Valve Implantation and protection by a lead cap.

OBJECTIVE: Transfemoral Transcatheter Aortic Valve Implantation (TAVI) has become a standard therapy for patients with aortic valve stenosis. Fluoroscopic imaging is essential for TAVI with the anesthesiologist's workplace close to patient's head side. While the use of lead-caps has been shown to be useful for interventional cardiologists, data are lacking for anesthesiologists. METHODS: A protective cap with a 0.35 lead-equivalent was worn on 15 working days by one anesthesiologist. Six detectors (three outside, three inside) were analyzed to determine the reduction of radiation. Literature search was conducted between April and October 2018. RESULTS: In the observational period, 32 TAVI procedures were conducted. A maximum radiation dose of 0.55 mSv was detected by the dosimeters at the outside of the cap. The dosimeters inside the cap, in contrast, displayed a constant radiation dose of 0.08 mSv. CONCLUSION: The anesthesiologist's head is exposed to significant radiation during TAVI and it can be protected by wearing a lead-cap.

Pharmacokinetics of cefuroxime in infants and neonates undergoing cardiac surgery.

AIMS: Very little data exist regarding the effect of cardiopulmonary bypass (CPB) on cefuroxime (CXM) pharmacokinetics in children less than one year of age. METHODS: 50 mg kg-1 CXM i.v. after induction were followed by 75 mg kg-1 into the CPB circuit. In 42 patients undergoing cardiac surgery, 15-20 samples were obtained between 5 and 360 min after the first dose. Total CXM concentrations were measured by high-performance liquid chromatography and a pharmacokinetic/pharmacodynamic (PK/PD) modelling was performed. RESULTS: Using a fixed protein binding of 15.6% for CXM, peak plasma concentrations of unbound CXM were 229 ± 52 µg ml-1 after the first bolus and 341 ± 86 µg ml-1 on CPB. Nadir concentrations before CPB were 69 ± 20 µg ml-1 and six hours later decreased to 41 ± 19 µg ml-1 with and 24 ± 14 µg ml-1 without CPB. A two-compartment model was fitted with the main covariates body weight, CPB and postmenstrual age (PMA). PK parameters were as follows: systemic clearance, 5.15 [95% CI 4.5-5.8] l h-1 ; central volume of distribution, 11.25 [9.41-13.09] l; intercompartmental clearance, 18.19 [14.79-21.58] l h-1 ; and peripheral volume, 17.07 [15.7-18.5] L. ƒT > MIC of 32 µg ml-1 for an 8-h time period was between 70 and 100% (2.5-10 kg BW). According to our simulation, 25 mg ml-1 CXM as a primary bolus and into the prime plus a 5 mg kg-1  h-1 infusion maintain CXM concentrations continuously above 32 µg ml-1 . CONCLUSIONS: The routine dosing regimen provided was sufficient for prophylaxis, but continuous dosing can provide a higher percentage of ƒT > MIC.

Dexmedetomidine versus propofol-opioid for sedation in transcatheter aortic valve implantation patients: a retrospective analysis of periprocedural gas exchange and hemodynamic support.

PURPOSE: Different sedation regimens have been described for use during transfemoral transcatheter aortic valve implantation (tf-TAVI) for treatment in patients with severe aortic stenosis. The purpose of this study was to compare dexmedetomidine (DEX) with a combination of propofol-opioid (PO) with respect to periprocedural gas exchange and hemodynamic support. METHODS: Data from a cohort of patients sedated with either DEX or PO for tf-TAVI were retrospectively analyzed from a prospectively maintained TAVI registry. Operative risk was determined from comorbidities and risk scores. Periprocedural partial pressure of carbon dioxide (PaCO2) was chosen as the primary endpoint. Other differences in gas exchange, need for catecholamine therapy, the frequency of conversion to general anesthesia, and need for sedative "rescue therapy" (in DEX patients) were secondary endpoints. Inverse probability of treatment weighting (IPTW) was used for analysis to minimize any selection bias. RESULTS: Of the 297 patients (140 PO, 157 DEX) included, the median [interquartile range] periprocedural PaCO2 values of DEX patients were significantly lower than in PO patients (40 [36-45] mmHg vs 44 [40-49] mmHg, respectively; median difference -4 mmHg; 95% confidence interval, -5 to -3 mmHg; P < 0.001). Hypercapnia (PaCO2 > 45 mmHg) was significantly less frequent in DEX patients compared with the PO group (25% vs 42%, respectively; P = 0.005). Vasopressor support was more frequent in the PO group compared with DEX (68% vs 25%, respectively; P < 0.001). Conversion to general anesthesia was not different between groups (9%, PO vs 3%, DEX; P = 0.051). Additional sedatives/opioids were required in 25 (16%) of the DEX patients. CONCLUSIONS: In sedated TAVI patients, DEX was associated with lower PaCO2 values and reduced requirements for vasopressor support, making it a promising alternative to PO for sedation during TAVI. TRIAL REGISTRATION: www.ClinicalTrials.gov (NCT01390675). Registered 11 July 2011.

Pharmacokinetics of tranexamic acid in neonates and infants undergoing cardiac surgery.

AIM: Tranexamic acid (TXA) continues to be one of the antifibrinolytics of choice during paediatric cardiac surgery. However, in infants less than 1 year of age, the optimal dosing based on pharmacokinetic (PK) considerations is still under discussion. METHODS: Forty-three children less than 1 year of age were enrolled, of whom 37 required the use of cardiopulmonary bypass (CPB) and six were operated on without CPB. Administration of 50 mg kg-1 TXA intravenously at the induction of anaesthesia was followed by 50 mg kg-1 into the CPB prime in the CPB group. Plasma concentrations of TXA were analysed by gas chromatography-mass spectrometry. PK data were investigated using nonlinear mixed-effect models. RESULTS: A two-compartment model was fitted, with the main covariates being allometrically scaled bodyweight, CPB, postmenstrual age (PMA). Intercompartmental clearance (Q), peripheral volume (V2), systemic clearance, (CL) and the central volume (V1) were calculated. Typical values of the PK parameter estimates were as follows: CL = 3.78 [95 % confidence interval (CI) 2.52, 5.05] l h-1 ; central volume of distribution = 13.6 (CI 11.7, 15.5) l; Q = 16.3 (CI 13.5, 19.2) l h-1 ; V2 = 18.0 (CI 16.1, 19.9) l. Independently of age, 10 mg kg-1 TXA as a bolus, a subsequent infusion of 10 mg kg-1 h-1 , then a 4 mg kg-1 bolus into the prime and a reduced infusion of 4 mg kg-1 h-1 after the start of CPB are required to maintain TXA concentrations continuously above 20 µg ml-1 , the threshold value for an effective inhibition of fibrinolysis and far lower than the usual peak concentrations (the '10-10-4-4 rule'). CONCLUSIONS: The introduction of a modified dosing regimen using a starting bolus followed by an infusion and a CPB prime bolus would prohibit the potential risk of seizures caused by high peak concentrations and also maintain therapeutic plasma concentration above 20 µg ml-1 .

Right Minithoracotomy Versus Full Sternotomy for Mitral Valve Repair: A Propensity Matched Comparison.

BACKGROUND: Mitral valve (MV) repair through a right minithoracotomy (RT) is technically more demanding than through a median sternotomy (MS) and has been cited for a higher rate of reoperation, increased postoperative bleeding, thromboembolic events, poor visualization, and longer operative times. Randomized studies are not available, however, and specific characteristics of patients who undergo operation with either technique are usually highly different. Therefore, a propensity matching study was performed to reduce selection bias. METHODS: A retrospective analysis was made of 745 patients, 501 in group RT (67%) and 244 in group MS (33%), who underwent isolated MV repair between 2000 and 2010. Propensity matching identified 97 matched patient pairs for comparison of functional outcome, survival, incidence of reoperation, and quality of life after MV repair. RESULTS: Propensity matched patients in group RT had longer cardiopulmonary bypass time (120 ± 28 versus 99 ± 30 minutes, p < 0.001) and cross-clamp time (86 ± 23.5 versus 74 ± 25 minutes, p < 0.001). Thirty-day mortality was similar for both groups (RT, 0%; MS, 1%; p = 0.13). There were no significant differences in other outcomes such as amount of red blood cell transfusion, ventilation time, and hospital stay. Five-year survival in group RT (93.5% ± 3.7%) versus group MS (87.4% ± 3.6%, p = 0.556) and freedom from MV reoperation (93.3% ± 2.9% versus 97.9% ± 1.5%, respectively; p = 0.157) were not different. Functional outcome and quality of life variables were similar. CONCLUSIONS: Mitral valve surgery through a right minithoracotomy is a safe procedure associated with a very low operative mortality comparable to the standard sternotomy approach. In addition to improved cosmetics, minimally invasive MV surgery provides equally durable results as the standard sternotomy approach.

The effect of cyanosis on perioperative platelet function as measured by multiple electrode aggregometry and postoperative blood loss in neonates and infants undergoing cardiac surgery.

OBJECTIVES: Platelet dysfunction is one of the major haematological disturbances of cardiopulmonary bypass (CPB). In addition, cyanosis is known to cause further coagulation disturbances. METHODS: We prospectively studied 110 children under 1 year of age for the effects of cyanosis on baseline platelet aggregation, the time course of function on cardiopulmonary bypass, the effect on chest tube drainage (CTD) and the transfusion requirements. Using multiple electrode aggregometry (MULTIPLATE™) with the activators adenosine diphosphate (ADP) and thrombin-related activation peptide (TRAP), platelet aggregation was assessed and examined for predictive value. RESULTS: Neonates under 30 days of age (n = 51) and infants (n = 59) were separated for analysis. Cyanosis had no significant effect on platelet function during the first 24 h after surgery. Similarly, there was no association to perioperative platelet function, CTD or exposures to blood products. ADP after protamine correlated significantly with the total number of exposures for neonates and infants and CTD at 6 h in the newborn group. Upon intensive care unit admission, ADP values correlated to the total number of exposures to blood products. No other platelet function value was able to clinically predict CTD or subsequent blood transfusion requirements. CONCLUSIONS: In our study population, we observed no clinically significant effect of cyanosis on baseline and the perioperative course of platelet function, CTD and the number of exposures to blood products. Therefore, children under 1 year of age do not require a different approach with regard to platelet transfusions, independent of cyanosis. Clinically, platelet function was not a reliable predictor of CTD or blood transfusion requirements.

The perioperative course of factor XIII and associated chest tube drainage in newborn and infants undergoing cardiac surgery.

BACKGROUND: Perioperative acquired factor XIII deficiency has been looked upon as a potential cause of postoperative bleeding in adult cardiac surgery. METHODS: Forty-four infants were prospectively studied for the time course of factor XIII in plasma and the effect on chest tube drainage (CTD) and transfusion requirements in the first 24 h after surgery. A reconstituted blood prime (RBP) with fresh-frozen plasma (FFP) and packed red blood cells (PRBC) was used. Samples were taken at baseline, after cardiopulmonary bypass and upon arrival in the ICU. Differences in blood loss and transfusion requirements based on a cutoff value of 70% factor XIII activity at the time of ICU admission were also calculated. RESULTS: Baseline factor XIII activity was 79%, decreased to 71% after CPB (P = 0.102) and increased back up to 77% at ICU arrival (P = 0.708). There was no significant correlation between factor XIII, CTD, age, cyanosis, platelet count, and transfusion requirements at any time point. Only preoperative fibrinogen levels correlated significantly with factor XIII activity. Perioperative blood transfusions (PRBC P = 0.712, FFP P = 0.909, platelets P = 0.807) and chest tube losses (P = 0.424 at 6 h and P = 0.215 at 24 h) were not significantly different above or below a 70% factor XIII activity at ICU arrival. CONCLUSION: Factor XIII activity in infants with congenital heart defects is within the lower range of normal adults, independent of patient's age and the presence of cyanosis. Reconstituted blood prime maintains factor XIII activity at sufficient levels during pediatric cardiac surgery. We could not detect a correlation between FXIII and CTD.

Transatrial antegrade approach for double mitral and tricuspid "valve-in-ring" implantation.

Within the last 5 years, the number of transcatheter aortic valve implantation (TAVI) procedures has increased continuously and, in parallel, the indications for TAVI have expanded (eg, failing surgical valves and rings). Furthermore, alternative TAVI access routes such as transaxillary and transaortic have been applied successfully. We report on, to our knowledge, the first-in-human case of a combined off-pump antegrade transatrial implantation of a transcatheter valve within a mitral and tricuspid annuloplasty ring through an anterolateral minithoracotomy. The patient showed severe mitral valve and tricuspid valve stenosis and regurgitation 15 years after mitral valve repair and 7 years after aortic valve replacement and tricuspid valve repair.

Tricuspid valve repair: is ring annuloplasty superior?

OBJECTIVES: Tricuspid regurgitation (TR) secondary to left heart disease is the most common aetiology of tricuspid valve (TV) insufficiency. Valve annuloplasty is the primary treatment for TV insufficiency. Several studies have shown the superiority of annuloplasty with a prosthetic ring over other repair techniques. We reviewed our experience with different surgical techniques for the treatment of acquired TV disease focusing on long-term survival and incidence of reoperation. METHODS: A retrospective analysis of 717 consecutive patients who underwent TV surgery between 1975 and 2009 with either a ring annuloplasty [Group R: N = 433 (60%)] or a De Vega suture annuloplasty [Group NR: no ring; N = 255 (36%)]. Twenty-nine (4%) patients underwent other types of TV repair. A ring annuloplasty was performed predominantly in the late study period of 2000-09. TV aetiology was functional in 67% (479/717) of the patients. Ninety-one percent of the patients (n = 649) underwent concomitant coronary artery bypass grafting and/or mitral/aortic valve surgery. RESULTS: Patients who received a ring annuloplasty were older (67 ± 13 vs 60 ± 13 years; P < 0.001). Overall 30-day mortality was 13.8% (n = 95) [Group R: n = 55 (12.7%) and Group NR: n = 40 (15.7%)]. Ten-year actuarial survival after TV repair with either the De Vega suture or ring annuloplasty was 39 ± 3 and 46 ± 7%, respectively (P = 0.01). Twenty-eight (4%) patients required a TV reoperation after 5.9 ± 5.1 years. Freedom from TV reoperation 10 years after repair with a De Vega annuloplasty was 87.9 ± 3% compared with 98.4 ± 1% after the ring annuloplasty (P = 0.034). CONCLUSIONS: Patients who require TV surgery either as an isolated or a combined procedure constitute a high-risk group. The long-term survival is poor. Tricuspid valve repair with a ring annuloplasty is associated with improved survival and a lower reoperation rate than that with a suture annuloplasty.

Transcatheter aortic valve implantation for failing surgical aortic bioprosthetic valve: from concept to clinical application and evaluation (part 1).

With an aging population, improvement in life expectancy, and significant increase in the use of bioprosthetic valves, structural valve deterioration will become more and more prevalent. The operative mortality for an elective redo aortic valve surgery is reported to range from 2% to 7%, but this percentage can increase to more than 30% in high-risk and nonelective patients. Because transcatheter aortic valve (TAV)-in-surgical aortic valve (SAV) implantation represents a minimally invasive alternative to conventional redo surgery, it may prove to be safer and just as effective as redo surgery. Of course, prospective comparisons with a large number of patients and long-term follow-up are required to confirm these potential advantages. It is axiomatic that knowledge of the basic construction and dimensions, radiographic identification, and potential failure modes of SAV bioprostheses is fundamental in understanding key principles involved in TAV-in-SAV implantation. The goals of this paper are: 1) to review the classification, physical characteristics, and potential failure modes of surgical bioprosthetic aortic valves; and 2) to discuss patient selection and procedural techniques relevant to TAV-in-SAV implantation.

Transcatheter aortic valve implantation for failing surgical aortic bioprosthetic valve: from concept to clinical application and evaluation (part 2).

OBJECTIVES: This study sought to review the acute procedural outcomes of patients who underwent transcatheter aortic valve (TAV)-in-surgical aortic valve (SAV) implantation at the German Heart Center, Munich, and to summarize the existing literature on TAV-in-SAV implantation (n = 47). BACKGROUND: There are several case reports and small case series describing transcatheter aortic valve implantation for a failing surgical aortic valve bioprosthesis (TAV-in-SAV implantation). METHODS: From January 2007 to March 2011, 20 out of 556 patients underwent a TAV-in-SAV implantation at the German Heart Center Munich. Baseline characteristics and clinical outcome data were prospectively entered into a dedicated database. RESULTS: The mean patient age was 75 ± 13 years, and the mean logistic European System for Cardiac Operative Risk Evaluation and Society of Thoracic Surgeons' Risk Model scores were 27 ± 13% and 7 ± 4%, respectively. Of the 20 patients, 14 had stented and 6 had stentless surgical bioprostheses. Most cases (12 of 20) were performed via the transapical route using a 23-mm Edwards Sapien prosthesis (Edwards Lifesciences, Irvine, California). Successful implantation of a TAV in a SAV with the patient leaving the catheterization laboratory alive was achieved in 18 of 20 patients. The mean transaortic valve gradient was 20.0 ± 7.5 mm Hg. None-to-trivial, mild, and mild-to-moderate paravalvular aortic regurgitation was observed in 10, 6, and 2 patients, respectively. We experienced 1 intraprocedural death following pre-implant balloon aortic valvuloplasty ("stone heart") and 2 further in-hospital deaths due to myocardial infarction. CONCLUSIONS: TAV-in-SAV implantation is a safe and feasible treatment for high-risk patients with failing aortic bioprosthetic valves and should be considered as part of the armamentarium in the treatment of aortic bioprosthetic valve failure.

Incidence and treatment of procedural cardiovascular complications associated with trans-arterial and trans-apical interventional aortic valve implantation in 412 consecutive patients.

OBJECTIVE: Trans-catheter aortic valve implantation (TAVI) technology is rapidly evolving, with 412 procedures having been performed at our institution. Herein, we report a complete, prospective analysis of complications occurring during transvascular and trans-apical implantations with two different prostheses. METHODS: Between June 2007 and June 2010, 412 patients (258 female, mean age 80.3±7.2 years, logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) 20.2%±13.0%) underwent TAVI through either a retrograde (n=252 transfemoral, n=28 transaxillary, and n=5 transaortic) or antegrade (n=127 trans-apical) approach at our institution. The trans-apical access was chosen only in cases where transvascular implantation was not possible. As many as 283 CoreValve and 129 Edwards Sapien prostheses were implanted. RESULTS: Thirty-day survival was 90.9%. Vascular complications occurred in 42 patients (10.2%). In four patients, lethal aortic root (n=3) or abdominal (n=1) aortic rupture occurred. Pericardial effusion developed in 53 patients (12.8%), which resulted in cardiac tamponade in 12 patients (2.9%). Twenty-three patients (5.6%) with valve malplacement were treated interventionally. In five patients (1.2%), emergency institution of cardiopulmonary bypass was required during the procedure for temporary support; all patients survived. Seventeen patients underwent re-intervention on the catheter valve (4.1%). CONCLUSIONS: With growing experience, complications with TAVI may be avoided by proper patient selection and skillful management. Other complications, when they occur, require a specific treatment algorithm to avoid delay in decision making. A considerable number of complications after TAVI require surgical treatment. Therefore, the ideal environment for TAVI procedures is a hybrid operating room, where a multidisciplinary team of surgeons, cardiologists, and anesthesiologists is best fitted to meet the current needs associated with TAVI technology. A reduction in complications was seen after 300 cases. This finding attests to the complexity of the procedure in addition to the experience required to reduce the incidence of complications.

Are the point-of-care diagnostics MULTIPLATE and ROTEM valid in the setting of high concentrations of heparin and its reversal with protamine?

OBJECTIVES: To evaluate the in vitro effects of high concentrations of heparin and its reversal with protamine on routine laboratory parameters as well as on modified thromboelastogram (ROTEM; TEM International, Munich, Germany) and impedance aggregometry (MULTIPLATE; Dynabyte, Munich, Germany). DESIGN: An observational, nonrandomized in vitro study. SETTING: A single-center, university hospital. PARTICIPANTS: Ten healthy volunteers. INTERVENTIONS: Heparinization of whole blood to levels of 2, 4, 6, and 8 IU/mL of heparin and reversal with protamine. For MULTIPLATE measurements, heparin levels up to 20 IU/mL were tested. MEASUREMENTS AND MAIN RESULTS: The present results show that the prothrombin time (PT) and fibrinogen measurements are altered significantly by heparin concentrations above 2 IU/mL. Protamine reversal also affected coagulation tests except for the fibrinogen. The INTEM test using the ROTEM system was influenced significantly by heparin concentrations of 2 IU/mL or higher, whereas EXTEM measurements remained stable up to 4 IU/mL. The findings for the FIBTEM test were stable up to 6 IU/mL but then declined to values less than 50% of baseline at 8 IU/mL. HEPTEM results remained valid under all concentrations of heparin tested. The effect of protamine on ROTEM was seen mainly in the INTEM and HEPTEM measurements. Heparin concentrations up to a level of 20 U/mL had no effect on MULTIPLATE measurements. Effects of protamine on MULTIPLATE became significant at heparin-to-protamine ratios below 1:1 and were more pronounced for adenosine diphosphate than for thrombin receptor-activated protein testing. CONCLUSIONS: Neither fibrinogen (Clauss) nor derived fibrinogen or FIBTEM testing is valid in the setting of high concentrations of heparin unless antagonized by heparinase. Reversal of heparin with protamine worsens platelet function at all ratios as detected by aggregometry (MULTIPLATE) and thromboelastography (ROTEM), starting at a 1:1 ratio. Therefore, appropriate coagulation testing under cardiopulmonary bypass conditions should be selected carefully according to heparin levels. In particular, fibrinogen values are falsely low at heparin levels of 2 IU/mL and above. Therefore, newer algorithms promoting the correction of fibrinogen levels on cardiopulmonary bypass should be based on appropriate testing.

Chordal replacement versus quadrangular resection for repair of isolated posterior mitral leaflet prolapse.

BACKGROUND: In the past, chordal replacement techniques with expanded polytetrafluoroethylene sutures have been primarily reserved for anterior leaflet pathology, whereas the more frequent posterior leaflet prolapse was treated by resection. This study reports midterm results of isolated posterior prolapse repair with chordal replacement without resection as opposed to the quadrangular resection. METHODS: An analysis was made of 397 consecutive patients who underwent mitral valve repair for isolated posterior leaflet prolapse between 2000 and 2007. Of them, 205 patients (52%) underwent quadrangular resection (group R, "resection") and 192 patients (48%) underwent a neochordal repair (group NR, "no resection"). The follow-up is 98% complete (mean follow-up of 383 survivors is 1.9+/-1.4 years). RESULTS: Overall 30-day mortality was 1.0% (4 of 397). Ten patients (2.5%) died late. Actuarial survival at 4 years for group R and group NR was 94%+/-3% and 98%+/-1%, respectively (p=0.99). Ten patients (2.5%) required a mitral valve-related reoperation after an average of 1.9+/-2 months. Freedom from reoperation at 4 years was 96%+/-1% for group R and 99%+/-1% for group NR (p=0.08). Generally, in patients of group NR, a larger annuloplasty ring could be implanted (mean size 32+/-2.5 versus 30+/-2, p<0.001). At latest follow-up, 94% of the patients showed no or grade I regurgitation, with no difference between groups. CONCLUSIONS: Repair of posterior mitral leaflet prolapse by chordal replacement is equally effective as classic quadrangular resection, permits the use of larger annuloplasty rings, offers a potentially more physiological repair with preserved leaflet mobility, and can be performed with excellent midterm results and a low incidence of reoperation.

Predonation of autologous blood reduces perioperative allogenic transfusion requirement in grown-up patients with congenital heart disease.

BACKGROUND: Adults with congenital heart diseases have a substantial risk for bleeding upon re-operations. Due to the detrimental effects of allogeneic blood transfusion, reduction of transfusion requirement is a major concern. To investigate the efficacy of autologous blood predonation (ABP), we focussed on a homogeneous subgroup of patients, with right ventricular outflow tract reconstruction. METHODS: Prospectively collected data included 76 patients older than 16 years with repeated right ventricular outflow tract reconstruction from May 1995 to November 2006. In 27 patients, ABP was performed without any complication. RESULTS: Primary diagnoses included Tetralogy of Fallot in 50 patients and others in 26 patients. All patients had at least one previous operation, 62% had more than one. All patients received a homograft conduit between the right ventricle and the pulmonary artery. Preoperative haemoglobin was 123+/-15 g l(-1) in patients with ABP and 134+/-22 g l(-1) in the remainder (p=0.037), but was not significantly different after cardiopulmonary bypass until discharge from the intensive care unit. Significantly more patients without ABP required transfusion of allogeneic packed red cells (PRCs) (26 of 49 patients (53%) vs 4 of 27 patients (15%), p=0.001) and allogeneic fresh frozen plasma (FFP) (30 of 49 patients (61%) vs 6 of 27 patients (22%), p=0.002) than patients with ABP. Of 27 patients, 23 (85%) and 25 (93%) with ABP received their predonated PRC and FFP, respectively. Logistic regression analysis identified no ABP (p=0.005, odds ratio (OR) 5.4, 95% confidence interval (CI) 1.7-17.7) and time on extracorporeal circulation >83 min (p=0.009, OR 5.0, 95% CI 1.5-16.8) to be predictive for allogeneic blood transfusion. CONCLUSION: ABP can be safely performed in grown-up patients with congenital heart disease without complications. Patients without predonation of autologous blood exhibit a fivefold increased risk for requiring allogeneic blood transfusion.

Percutaneous cannulation of the femoral vessels for cardiopulmonary bypass.

In case of minimally invasive open heart surgery, access for intrathoracic cannulation is limited and therefore femoral vessel cannulation is necessary. Complications after surgical exposure of the femoral vessels are well known. The authors describe their technique for percutaneous femoral vessel cannulation, which allows a safe establishment of cardiopulmonary bypass, reduces the incidence of groin complications, and offers excellent cosmetic results.

Risk factors for aortic insufficiency and aortic valve replacement after the arterial switch operation.

OBJECTIVE: Long-term results after the arterial switch operation have shown that patients may develop aortic insufficiency, and that some even require aortic valve replacement. METHODS: A retrospective review of 479 hospital survivors after the arterial switch operation (ASO) was performed. Echocardiographic findings were reviewed and the incidence, as well as the progression, of aortic insufficiency (AI) was investigated. The combined end point of the study was defined as the first documented occurrence of moderate or more aortic insufficiency or the need for aortic valve replacement (AVR). RESULTS: Upon discharge from the hospital 15% of the patients showed an AI of at least grade I, progressing to 20.7% after 1 year. At a mean follow-up time of 9.3+/-6 years, 249 patients (53%) were free from AI, trivial AI was present 179 patients (38%), mild AI in 34 patients (7.2%) and moderate AI in 7 patients (1.5%). There is a progression of AI with time after ASO (r=0.26, p<0.001). A total of 18 patients reached the combined end point, out of which 11 underwent an AVR at a mean time of 11.2 years after ASO. Freedom from the end point was 99.7+/-0.3%, 97.5+/-1%, 91.9+/-2%, 84.6+/-6% at 5, 10, 15 and 20 years, respectively. The following risk factors were identified by univariate analysis: Taussig-Bing anomaly (p=0.01), ventricular septal defect (VSD) (p=0.006), prior pulmonary artery banding (p=0.004), age over 12 months at time of ASO (p=0.001) and a postoperative incidence of trivial AI (p<0.0001). Independent risk factors by multivariate analysis were the presence of a left ventricular outflow tract obstruction (p<0.0001) and at least a trivial AI at 1 year after the ASO (p<0.0001). CONCLUSION: The incidence of trivial or mild AI after the ASO is considerable and a progression over time is evident. However, severe AI and the need for AVR are rare. Patients with VSD or Taussig-Bing anomaly, and those with left ventricular outflow tract obstruction exhibit a higher risk of developing significant aortic insufficiency. Particularly patients who have developed an AI at 1 year after the ASO need to be under close observation.