A novel intrapericardial pulsatile device for individualized, biventricular circulatory support without direct blood contact.

OBJECTIVE: Due to severely limited donor heart availability, durable mechanical circulatory support remains the only treatment option for many patients with end-stage heart failure. However, treatment complexity persists due to its univentricular support modality and continuous contact with blood. We investigated the function and safety of reBEAT (AdjuCor GmbH), a novel, minimal invasive mechanical circulatory support device that completely avoids blood contact and provides pulsatile, biventricular support. METHODS: For each animal tested, an accurately sized cardiac implant was manufactured from computed tomography scan analyses. The implant consists of a cardiac sleeve with three inflatable cushions, 6 epicardial electrodes and driveline connecting to an electro-pneumatic, extracorporeal portable driver. Continuous epicardial electrocardiogram signal analysis allows for systolic and diastolic synchronization of biventricular mechanical support. In 7 pigs (weight, 50-80 kg), data were analyzed acutely (under beta-blockade, n = 5) and in a 30-day long-term survival model (n = 2). Acquisition of intracardiac pressures and aortic and pulmonary flow data were used to determine left ventricle and right ventricle stroke work and stroke volume, respectively. RESULTS: Each implant was successfully positioned around the ventricles. Automatic algorithm electrocardiogram signal annotations resulted in precise, real-time mechanical support synchronization with each cardiac cycle. Consequently, progressive improvements in cardiac hemodynamic parameters in acute animals were achieved. Long-term survival demonstrated safe device integration, and clear and stable electrocardiogram signal detection over time. CONCLUSIONS: The present study demonstrates biventricular cardiac support with reBEAT. Various demonstrated features are essential for realistic translation into the clinical setting, including safe implantation, anatomical fit, safe device-tissue integration, and real-time electrocardiogram synchronized mechanical support, result in effective device function and long-term safety.

An in silico twin for epicardial augmentation of the failing heart.

Advances in ventricular assist device (VAD) technology for the treatment of end-stage congestive heart failure (CHF) are needed to cope with the increasing numbers of patients that cannot be provided with donor hearts for transplantation. We develop and investigate a novel extravascular VAD technology that provides biventricular, epicardial pressure support for the failing heart. This novel VAD concept avoids blood contact that is accompanied with typical complications such as coagulation and infections. To date, in vivo porcine model results with a prototype of the implant exist, further studies to improve the implant's performance and promote its applicability in humans are needed. In this contribution, we present a personalised functional digital twin of the heart, the vascular system, and the novel VAD technology in terms of a calibrated, customized computational model. The calibration procedure is based on patient-specific measurements and is performed by solving an inverse problem. This in silico model is able to (a) confirm in vivo experimental data, (b) predict healthy and pathologic ventricular function, and (c) assess the beneficial impact of the novel VAD concept to a high level of fidelity. The model shows very good agreement with in vivo data and reliably predicts increases in stroke volume and left ventricular pressure with increasing ventricular support. Furthermore, the digital twin allows insight into quantities that are poorly or not at all amenable in any experimental setup. Conclusively, the model's ability to link integral hemodynamic variables to local tissue mechanical deformation makes it a highly valuable tool for the dimensioning of novel VAD technologies and future treatment strategies in heart failure. The presented in silico twin enhances in vivo studies by facilitating the accessibility and increasing the range of quantities of interest. Because of its flexibility in the assessment of design variants and optimization loops, it may substantially contribute to a reduction of the amount of animal experiments in this and similar settings.

A bioresorbable biomaterial carrier and passive stabilization device to improve heart function post-myocardial infarction.

The limited regenerative capacity of the heart after a myocardial infarct results in remodeling processes that can progress to congestive heart failure (CHF). Several strategies including mechanical stabilization of the weakened myocardium and regenerative approaches (specifically stem cell technologies) have evolved which aim to prevent CHF. However, their final performance remains limited motivating the need for an advanced strategy with enhanced efficacy and reduced deleterious effects. An epicardial carrier device enabling a targeted application of a biomaterial-based therapy to the infarcted ventricle wall could potentially overcome the therapy and application related issues. Such a device could play a synergistic role in heart regeneration, including the provision of mechanical support to the remodeling heart wall, as well as providing a suitable environment for in situ stem cell delivery potentially promoting heart regeneration. In this study, we have developed a novel, single-stage concept to support the weakened myocardial region post-MI by applying an elastic, biodegradable patch (SPREADS) via a minimal-invasive, closed chest intervention to the epicardial heart surface. We show a significant increase in %LVEF 14 days post-treatment when GS (clinical gold standard treatment) was compared to GS + SPREADS + Gel with and without cells (p ≤ 0.001). Furthermore, we did not find a significant difference in infarct quality or blood vessel density between any of the groups which suggests that neither infarct quality nor vascularization is the mechanism of action of SPREADS. The SPREADS device could potentially be used to deliver a range of new or previously developed biomaterial hydrogels, a remarkable potential to overcome the translational hurdles associated with hydrogel delivery to the heart.

Individualized Biventricular Epicardial Augmentation Technology in a Drug-Induced Porcine Failing Heart Model.

For treatment of advanced heart failure, current strategies include cardiac transplantation or blood-contacting pump technology associated with complications, including stroke and bleeding. This study investigated an individualized biventricular epicardial augmentation technology in a drug-induced porcine failing heart model. A total of 11 pigs were used, for the assessment of hemodynamics and cardiac function under various conditions of support pressures and support durations (n = 4), to assess device positioning and function by in vivo computer tomographic imaging (n = 3) and to investigate a minimally invasive implantation on the beating heart (n = 4). Support pressures of 20-80 mm Hg gradually augmented cardiac function parameters in this animal model as indicated by increased left ventricular stroke volume, end-systolic pressures, and decreased end-diastolic pressures. Strong evidence was found regarding the necessity of mechanical synchronization of support end with the isovolumetric relaxation phase of the heart. In addition, the customized, self-expandable implant enabled a marker-guided minimally invasive implantation through a 4 cm skin incision using fluoroscopy. Correct positioning was confirmed in computer tomographic images. Continued long-term survival investigations will deliver preclinical evidence for further development of this concept.

A monolithic 3D-0D coupled closed-loop model of the heart and the vascular system: Experiment-based parameter estimation for patient-specific cardiac mechanics.

A model for patient-specific cardiac mechanics simulation is introduced, incorporating a 3-dimensional finite element model of the ventricular part of the heart, which is coupled to a reduced-order 0-dimensional closed-loop vascular system, heart valve, and atrial chamber model. The ventricles are modeled by a nonlinear orthotropic passive material law. The electrical activation is mimicked by a prescribed parameterized active stress acting along a generic muscle fiber orientation. Our activation function is constructed such that the start of ventricular contraction and relaxation as well as the active stress curve's slope are parameterized. The imaging-based patient-specific ventricular model is prestressed to low end-diastolic pressure to account for the imaged, stressed configuration. Visco-elastic Robin boundary conditions are applied to the heart base and the epicardium to account for the embedding surrounding. We treat the 3D solid-0D fluid interaction as a strongly coupled monolithic problem, which is consistently linearized with respect to 3D solid and 0D fluid model variables to allow for a Newton-type solution procedure. The resulting coupled linear system of equations is solved iteratively in every Newton step using 2  ×  2 physics-based block preconditioning. Furthermore, we present novel efficient strategies for calibrating active contractile and vascular resistance parameters to experimental left ventricular pressure and stroke volume data gained in porcine experiments. Two exemplary states of cardiovascular condition are considered, namely, after application of vasodilatory beta blockers (BETA) and after injection of vasoconstrictive phenylephrine (PHEN). The parameter calibration to the specific individual and cardiovascular state at hand is performed using a 2-stage nonlinear multilevel method that uses a low-fidelity heart model to compute a parameter correction for the high-fidelity model optimization problem. We discuss 2 different low-fidelity model choices with respect to their ability to augment the parameter optimization. Because the periodic state conditions on the model (active stress, vascular pressures, and fluxes) are a priori unknown and also dependent on the parameters to be calibrated (and vice versa), we perform parameter calibration and periodic state condition estimation simultaneously. After a couple of heart beats, the calibration algorithm converges to a settled, periodic state because of conservation of blood volume within the closed-loop circulatory system. The proposed model and multilevel calibration method are cost-efficient and allow for an efficient determination of a patient-specific in silico heart model that reproduces physiological observations very well. Such an individual and state accurate model is an important predictive tool in intervention planning, assist device engineering and other medical applications.

Hybrid debranching and TEVAR of the aortic arch off-pump, in re-do patients with complicated chronic type-A aortic dissections: a critical report.

BACKGROUND: Patients suffering from acute type A aortic dissection undergo replacement of the ascending aorta, the proximal hemiarch or complete aortic arch, depending on the extent of the individual pathology. In a subset of these treated patients, secondary pathologies of the distal anastomosis or the remaining distal part of the aorta occur. The treatment of these pathologies is challenging, requiring major surgical re-do procedures with aortic arch replacement under extracorporeal circulation and hypothermic circulatory arrest. METHODS: We report our experience of five patients with complex aortic pathologies after previous aortic surgery treated with a single stage re-do hybrid procedure, consisting of bypass grafting of the supraaortic branches off-pump, stent graft placement for endovascular aortic repair (TEVAR) and surgical debranching of the aortic arch. RESULTS: In all patients the surgical vascular grafts and stent grafts were deployed successfully, there were no intraoperative deaths. Four out of five patients were discharged from hospital in good clinical condition. One patient died postoperatively due to cardiac tamponade. In one patient a type I endoleak persisted leading to occlusion of a bypass branch requiring surgical revision at one year after debranching. CONCLUSION: We discuss the prerequisites, all steps and potential pitfalls of this hybrid aortic arch replacement. The current procedure avoids cardiopulmonary bypass and circulatory arrest, which may benefit early patient outcome; however, patient and device selection plays a key role for immediate success and midterm outcomes. In addition, precise procedural planning and development of customized stents may help to develop this procedure into a true alternative for conventional aortic arch replacement.

Fibrin sealant patch for repair of acute type a aortic dissection.

INTRODUCTION: The use of glues to repair disrupted tissue during acute type-A aortic dissection (TAD) surgery may be discontinuous, and cause embolization and cell necrosis. We report a method of fibrin sealant patch (FSP) to reinforce dissected aortic tissue with a collagen double layer coated with fibrinogen/thrombin on either side (TachoSil®; Takeda, Konstanz, Germany). METHODS: In 12 patients (seven male, 66.9 ± 11.7 years) with acute TAD we performed FSP of the intima-media disruption at the proximal and distal anastomosis of the aorta. We analyzed the perioperative course and echocardiographical, radiological, and clinical outcomes up to one year. Additionally, we investigated the adhesive potential of the FSP in vitro. RESULTS: In vitro, the adhesive strength of the FSP was 60 N/cm(2). In-hospital mortality was 8.3% (n = 1), recovery was satisfactory with no major neurologic events, mean ICU stay was 13.6 ± 6.0 days, mean hospital stay was 20.7 ± 4.4 days. A total of 7.0 ± 2.6 RBC, 3.4 ± 1.5 platelets, and 8.0 ± 4.3 FFP were transfused. One-year survival was 83.3%. In 6/6 DeBakey II dissections the intimal tear was completely resected, in 2/6 DeBakey I dissections the false lumen in the descending aorta completely collapsed. No redissections and no relevant aortic valve insufficiencies were seen during follow-up. CONCLUSION: This analysis shows that FSP using a collagen matrix double layer coated with fibrinogen/thrombin is feasible, safe, and effective in repairing the dissected aortic tissue. It results in continuous reinforcement of aortic tissue and completely avoids the need for conventional glues.

Asymptomatic melanoma of the superior cavo-atrial junction: The challenge of imaging.

METASTATIC LESIONS IN THE SUPERIOR VENA CAVA AND THE RIGHT ATRIUM ARE DIFFICULT TO DIAGNOSE: in computed tomography (CT), they are easily misinterpreted as artifacts, and the same region may be difficult to access using echocardiography. We present a case of asymptomatic metastasis of a malignant melanoma which was overlooked initially due to deficiencies in imaging. Using 18F-fluorodeoxyglucose positron emission tomography-CT, the metastasis was clearly identified and finally treated successfully. We discuss the diagnostic value of the various imaging modalities for intracardiac masses.

Prognostic value of mild-to-moderate pulmonary hypertension in patients with severe aortic valve stenosis undergoing aortic valve replacement.

BACKGROUND: Optimal timing of elective aortic valve replacement (AVR) for severe aortic stenosis (AS) is challenging. Hence, a sensitive marker in AS patients indicating increasing risk after AVR would be of great clinical value. In the present study, we hypothesized that mild-to-moderate pulmonary hypertension (PH) assessed prior to AVR is a sensitive marker for adverse events in patients after successful AVR. METHODS: We enrolled 200 consecutive patients with severe AS undergoing AVR. Among them, 176 patients (88%) were symptomatic. Patients were divided according to systolic pulmonary artery pressure (PAP(sys)) into three groups: no PH (PAP(sys) <30 mmHg), mild-to-moderate PH (PAP(sys) ≥30 and PAP(sys) <60 mmHg) and severe PH (≥60 mmHg). Multivariable analyses were adjusted for age and gender and included PH, left ventricular ejection fraction ≤35%, renal insufficiency and logistic EuroSCORE ≥20%. Primary endpoint was death of any cause within 5 years after AVR. RESULTS: During follow-up, 23 patients died (cumulative 5-year mortality rate 14.6%). Patients without (n = 78), mild-to-moderate (n = 99) and severe PH (n = 23) had 5-year mortality rates of 2.6, 15.2 and 26.1% (p = 0.001). PAPsys ≥30 mmHg yielded an excellent level of sensitivity of 92.8%. On multivariable analysis, mild-to-moderate PH was the only independent risk factor (hazard ratio 4.9, 95% confidence interval 1.1-21.8). CONCLUSIONS: In patients with severe AS undergoing AVR, mild-to-moderate PH is a strong and independent predictor of late mortality. Conversely, patients with normal PAP(sys) have an extremely good prognosis.

A step toward nonrobotic total endoscopic coronary bypass grafting: 40 coronary anastomoses in a biomechanical beating heart model.

OBJECTIVE: Nonrobotic total endoscopic coronary bypass grafting is commonly considered as technically too difficult. After endoscopic practicing in a simple box model, we questioned this statement in a more sophisticated training model. METHODS: In a handmade chest model containing a mechanically actuated porcine heart, anastomoses between homologous vein and shunted anterior coronary artery were performed using Prolene 7-0 sutures or U-clips in 20 anastomoses each. Commercially available endoscopic instruments and exclusive two-dimensional endoscopic vision were used. As quality control, the procedures were recorded, flow was measured, indocyanine green dye angiograms were performed, vinylpolysiloxane endocasts were produced, and finally the anastomoses were assessed from the endothelial side. Three-dimensional computed tomographic reconstruction was explored for cast measuring. RESULTS: All anastomoses were completed successfully in a time of 51 ± 14 minutes (Prolene) and 48 ± 10 minutes (U-clips). Despite suboptimal equipment, a reproducible sequence of the procedure was established and documented. Improving surgical performance was reflected in a reduction in anastomotic leakage and time requirement. The quality assessment protocol showed a learning curve and problems itself, which are briefly discussed. CONCLUSIONS: A beating heart model is an adamant requirement of training for the technically demanding procedure of nonrobotic total endoscopic coronary bypass grafting. Refinement of the model and quality assessment as well as expansion of training to other regions of the heart should prepare for a cost-effective, broad-based clinical application of nonrobotic endoscopic techniques in coronary surgery. Available high-definition three-dimensional vision systems and the development of appropriate (articulating) instruments will make the procedure safer and quicker and will cut the learning curve.

Identification of an up-regulated anti-apoptotic network in the internal thoracic artery.

BACKGROUND: The radial artery (RA) is known as an atherosclerosis-prone vessel in contrast to the atherosclerosis-resistant internal thoracic artery (ITA). The purpose of the present study was to compare the gene expression profile of these arteries from the same patient in order to identify genes involved in atherogenesis or intimal hyperplasia. METHODS: Paired specimens of RA and ITA (n=6) were analyzed by histomorphometry and whole genome microarray. The microarray data underwent pathway analysis to identify biological networks. Laser microdissection (LMD) was used to identify the cellular expression of candidate genes in the intimal or medial layer of the ITA and RA. RESULTS: Histomorphometric analyses revealed a significantly higher degree of intimal hyperplasia in the RA compared to the ITA. 552 genes were differentially expressed in the ITA and RA. qRT-PCR confirmed a significant up-regulation of six anti-apoptotic genes. p21 (11.8-fold, p=0.011), CCL2 (5.4-fold, p=0.034), SOCS3 (7.2-fold, p=0.002), IER3 (4.1-fold, p=0.048), MCL-1 (2.6-fold, p=0.025) and IL-6 (17.8-fold, p=0.046) were up-regulated in the ITA. LMD confirmed that cells of the intimal layer of the ITA consistently expressed higher levels of all six candidate genes than those of the RA. CONCLUSIONS: Microarray analysis and qRT-PCR identified significantly up-regulated genes in the ITA involved in an anti-apoptotic network. LMD revealed a higher expression of all anti-apoptotic genes in the intimal area of the ITA. These genes may play an important role in protecting the intima of the ITA from developing hyperplasia and atherosclerosis.

Patient-centered cardiopulmonary bypass concepts.

This review outlines and discusses the newest technologies used for cardiopulmonary bypass (CPB) including changes in pump technology, oxygenators, filters, and priming. In addition, evidence-based and experience-based procedures are presented in line with the recommendations given on what CPB-related practices are safe and effective.

Partial median "I" sternotomy: minimally invasive alternate approach for aortic valve replacement.

Minimally invasive aortic valve replacement using the inversed L-like partial upper sternotomy has evolved during the last 10 years. It is performed with excellent results with regard to sternal stability and cosmesis. However, the lateral incision may result in sternal overriding, instability, or fracture. We present an alternate minimally invasive approach to aortic valve replacement. We performed a partial median "I" sternotomy in 30 consecutive patients: After a 6- to 8-cm skin incision, the sternum was incised from the jugulum downward to the corpus, ending at the level of the fourth or fifth intercostal space. No lateral incision of the sternum was performed. The access to the heart and aorta was excellent. During the postoperative course and during follow-up, clinical examination revealed sternal stability and normal wound healing in all patients. These results show that the partial median I sternotomy can be performed safely and provides excellent clinical and cosmetic results.

A rat model of cardiopulmonary bypass with cardioplegic arrest and hemodynamic assessment by conductance catheter technique.

BACKGROUND: Cardiopulmonary bypass (CPB) is known to induce systemic inflammation and cardiac dysfunction associated with a significant morbidity. Aim of the study was to develop an in vivo model of rat CPB with hypothermic cardiac arrest and the use of cardioplegia. MATERIAL AND METHODS: The CPB circuit consisted of a venous reservoir, membrane oxygenator, heat exchanger, and roller pump. CPB was instituted in adult male Wistar rats (400-500 g) for 60 min at a flow rate of 120 ml x kg(-1) x min(-1), including 15 min cooling to 32 degrees C, 30 min cardiac arrest with the use of cold crystalloid cardioplegia after aortic cross clamping, and 15 min of reperfusion and rewarming to 37 degrees C. Arterial blood pressure (MAP) and heart rate (HR) were monitored, arterial blood samples were analyzed. Left ventricular (LV) function parameters were assessed by intraventricular conductance catheter. Important technical aspects are: ventilation is required during partial bypass; anticoagulation should be performed immediately prior to CPB to reduce blood loss; active suction on venous drainage allows higher pump flows; and the small priming volume of the extracorporeal circuit (8 ml) avoids the need for donor blood. RESULTS: MAP remained stable prior to and during CPB.MAP and HR were significantly decreased 60 min after weaning from bypass. Hct was significantly lowered after hemodilution, but remained stable during CPB and 60 min after weaning from bypass. BE and pH remained stable throughout the experiment.Without inotropic support diastolic and systolic LV function parameters were impaired after 30 min of cardioplegic arrest followed by 15 min of reperfusion. Myocardial TNF-alpha mRNA levels were slightly increased (1.28-fold, p = 0.71), and IL-6 mRNA was significantly increased in the cardioplegia group (90.3-fold, p = 0.001). Both IL-6 and TNF-alpha plasma levels were significantly elevated in the cardioplegia group (TNF-alpha: 4.6-fold increase,p < 0.05; IL-6: 426.8-fold increase, p < 0.001). CONCLUSIONS: We have developed a rat CPB with mild hypothermic cardioplegic arrest. This rodent model is suitable to study clinically relevant problems related to CPB,myocardial protection and systemic inflammation.

Factor V Leiden does not affect bleeding in aprotinin recipients after cardiopulmonary bypass.

BACKGROUND: Carriers of the factor V Leiden mutation (FVL) are resistant to activated protein C proteolysis. Therefore, they are at increased risk of thromboembolic events. Aprotinin is an unspecific proteinase inhibitor frequently used during cardiac surgery procedures to reduce bleeding. However, aprotinin may cause thromboembolic complications after cardiopulmonary bypass (CPB). The primary endpoint of this study was the amount of blood loss after CPB in aprotinin recipients, and secondary endpoints were thromboembolic complications. METHODS: A total of 1,447 consecutive patients who underwent cardiac surgery with CPB were prospectively enrolled. All patients were screened for FVL by a fluorescence-based polymerase chain reaction method. Linear and logistic regression analyses were performed to assess associations of FVL on bleeding and thromboembolic complications. RESULTS: One hundred seven individuals (7.4%) were heterozygous FVL carriers. No difference was found between FVL carriers and noncarriers regarding age, sex, CPB, type of operation, EuroSCORE, antiplatelet treatment, and reoperation. FVL was not significantly associated with postoperative blood loss, whereas a significant influence was found for female sex (P < 0.0001), duration of CPB (P < 0.0001), reoperation (P = 0.001), and preoperative antiplatelet treatment (P < 0.002). Multiple linear regression analysis for total blood loss had an observed power of at least 99%. FVL carriers faced the same risk for postoperative transfusion (P = 0.391), reoperation (P = 0.675), myocardial infarction (P = 0.44), stroke (P = 0.701), and 30-day mortality (P = 0.4) as did noncarriers. CONCLUSIONS: These data suggest that FVL carriers do not have reduced blood loss compared with noncarriers. Furthermore, the combination of aprotinin and FVL does not enhance the risk for thromboembolic complications.

Autonomic control in patients experiencing atrial fibrillation after cardiac surgery.

BACKGROUND: Atrial fibrillation (AF) occurs in 20-40% of patients after open heart surgery and leads to an increased morbidity and prolonged hospital stay. Earlier studies have demonstrated that depressed baroreflex function predicts mortality and major arrhythmic events in patients surviving myocardial infarction. Cardiac surgery per se leads to decreased baroreflex sensitivity (BRS) and heart rate variability (HRV). Hence, the present study was aimed at analyzing the impact of the cardiovascular autonomous system on the development of postsurgical AF. METHODS AND RESULTS: The study covered 51 patients who consecutively underwent aortic valve replacement, coronary artery bypass surgery, or combined procedures. Noninvasive blood pressure and ECG were recorded the day before and 24 hour after surgery. BRS, linear as well as nonlinear HRV parameters were calculated using established methods. Eighteen patients developed AF during the first postoperative week, while 33 remained in sinus rhythm (SR) throughout the observation period. Patients with postoperative (PostOp) AF exhibited a significantly reduced preoperative (PreOp) BRS in terms of bradycardic and tachycardic regulation (average delayed slope [ms/mmHg]: SR: PreOp: 9.83 +/- 3.26, PostOp: 6.02 +/- 2.29, Pre-Post: P < 0.001; AF: PreOp: 7.59 +/- 1.99, PostOp: 6.39 +/- 3.67, Pre-Post: P < 0.044; AF vs SR: PreOp: P < 0.01, PostOp: ns). In both groups, surgery caused a decrease of BRS and HRV. Analysis of nonlinear dynamics revealed a tendency toward decreased system complexity caused by the operation; this trend was significant in patients remaining in sinus rhythm. CONCLUSIONS: Patients experiencing postoperative AF obviously suffer from an impaired BRS before surgery already. These findings may be used to guide prophylactic antiarrhythmic therapy.

Severe superior vena cava syndrome after transvenous pacemaker implantation.

Superior vena cava syndrome is a rare complication after pacemaker implantation. The present report outlines how underestimation of clinically relevant symptoms of superior vena cava syndrome early after pacemaker implantation may result in severe complication with the need for major surgical intervention. Superior vena cava syndrome should be diagnosed early because immediate thrombolytic therapy is effective in the majority of patients and avoids the requirement for interventional or surgical efforts.

Graft function, histopathology and morphometry of radial arteries used as conduits for myocardial revascularization in patients beyond age 70.

BACKGROUND: Coronary artery bypass grafting (CABG) using radial arteries has become a standard procedure for younger patients in many centers. However, advanced atherosclerotic changes may limit its use in older patients. We studied the effects of age on morphologic and histopathologic findings in CABG patients aged 70 years and older. METHODS: In 31 consecutive patients aged 70-85 (mean 77+/-8 years) scheduled for elective CABG, the left or right radial artery (RA) was used to graft the second target vessel (first graft: LIMA-LAD). Preoperative Doppler flow and Allen's test were satisfactory. Intraoperatively the distal segment adjacent to the anastomosis site of the RA was collected for histologic evaluation. Intraoperative angiography, measurement of flow, and resistance index (PI) were performed to document graft quality. Histopathology and morphometry were used to measure intimal and medial areas (IA, MA; microm2), intimal thickening index (ITI), relation between intimal and medial width at maximum intimal thickness (IMR), and percentage of luminal narrowing (%LN). RESULTS: The RA showed no evidence for stenosis of the conduits or the anastomosis. In all grafts flow and PI were satisfactory (76+/-14 ml/min; PI: 2.2+/-0.9). Histopathology and morphometry showed atherosclerotic changes in all RA grafts: IA: 890+/-971 (range 286-5244), MA: 2751+/-818 (range 1357-4989), ITI: 0.26+/-0.09 (range 0.12-0.44), IMR: 0.59+/-0.28 (range 0.21-1.13) %LN: 38+/-5 (range 13.2-61.7). Age as well as classic risk factors including diabetes, hypertension, smoking, and hyperlipidemia did not correlate with RA atherosclerosis. CONCLUSIONS: Excellent macroscopic and angiographic results were obtained. All grafts used showed minor to moderate atherosclerotic changes without severely altered indices of intimal thickening or luminal narrowing. The radial artery must be used with caution; however, age should not be an exclusion criterion per se.