Preclinical Comparison of Distal Off-Pump Anastomotic Remodeling: Hand-Sewn Versus ELANA Heart Bypass.

Objective: The ELANA Heart Bypass System is a new sutureless technique for coronary anastomoses. A titanium clip connects the graft with the coronary artery, whereafter the arteriotomy is performed by excimer laser. Since this anastomotic construction evidently differs from the standard hand-sewn anastomosis, we aim to evaluate the process of anastomotic healing and remodeling. Methods: Preclinical evaluation of anastomotic remodeling in 42 pigs who underwent off-pump left internal mammary artery to left anterior descending artery anastomosis by either the ELANA Heart Bypass (n = 24) or the hand-sewn (n = 18) technique. Anastomotic remodeling was evaluated by scanning electron microscopy and histology in short-term follow-up intervals up to 3 months. Anastomotic patency is determined by coronary angiography at latest follow-up before termination. Results: The nonendothelial surface of both the ELANA and the hand-sewn anastomoses were covered with neointima from 14 days onwards. Only half the amount of intima hyperplasia was present in the anastomotic surface of the patent ELANA anastomosis, compared with the hand-sewn anastomosis (98 [48-1358] vs 218 [108-296] µm, P = 0.001). Yet patency of the ELANA was inferior to the hand-sewn anastomoses (79% vs 100%, P = 0.06). Conclusions: This study shows the technical perioperative feasibility of the ELANA Heart Bypass System. Although limited intima hyperplasia was observed, hand-sewn anastomoses had superior patency during follow-up. The results of this trial suggest that an additional study with a new prototype is required before clinical implementation.

Preclinical Feasibility and Patency Analyses of a New Distal Coronary Connector: The ELANA Heart Bypass.

OBJECTIVE: This preclinical study determines the feasibility and 6-month patency rates of a new distal coronary connector, the Excimer Laser Assisted Nonocclusive Anastomosis (ELANA) Heart Bypass. METHODS: Twenty Dutch Landrace pigs received either a hand-sewn (n = 8) or an ELANA (n = 12) left internal thoracic artery to left anterior descending artery anastomosis, using off-pump coronary artery bypass grafting. Six-month patency rates were demonstrated by coronary angiography and histological evaluation. Throughout, procedural details and complication rates were collected. RESULTS: The ELANA Heart Bypass demonstrated 0% mortality and complication rates during follow-up. It was demonstrated feasible, with comparable perioperative flow measurements (ELANA vs hand-sewn, median [min to max], 24 [14 to 28] vs 17 [12 to 31] mL/min; P = 0.601) and fast construction times (3 [3 to 7] vs 31 [26 to 37] min; P < 0.001). Yet, an extra hemostatic stitch was needed in 25% of the ELANA versus 12.5% of the hand-sewn anastomoses. The 6-month patency rate of the ELANA Heart Bypass was 83.3% versus 100% in hand-sewn anastomoses. The 2 occluded ELANA-anastomoses were defined model-based errors. CONCLUSIONS: The ELANA Heart Bypass facilitates a sutureless distal coronary anastomosis. A design change is suggested to improve hemostasis and will be evaluated in future translational studies. This new technique is a potential alternative to hand-sewn anastomoses in (minimally invasive) coronary surgery.

A single preoperative blood test predicts postoperative sepsis and pneumonia after coronary bypass or open aneurysm surgery.

BACKGROUND: Major surgery comes with a high risk for postoperative inflammatory complications. Preoperative risk scores predict mortality risk but fail to identify patients at risk for complications following cardiovascular surgery. We therefore assessed the value of preoperative red cell distribution width (RDW) as a predictor for pneumonia and sepsis after cardiovascular surgery and studied the relation of RDW with hematopoietic tissue activity. METHODS: RDW is an easily accessible, yet seldomly used parameter from routine haematology measurements. RDW was extracted from the Utrecht Patient Orientated Database (UPOD) for preoperative measurements in patients undergoing open abdominal aortic anuerysm repair (AAA)(N = 136) or coronary artery bypass grafting (CABG)(N = 2193). The cohorts were stratified in tertiles to assess effects over the different groups. Generalized Linear Models were used to determine associations between RDW and postoperative inflammatory complications. Hematopoietic tissue activity was scored using fluor-18-(18F)-deoxyglucose positron emission tomography and associated with RDW using linear regression models. RESULTS: In total, 43(31.6%) and 73 patients (3.3%) suffered from inflammatory complications after AAA-repair or CABG, respectively; the majority being pneumonia in both cohorts. Postoperative inflammatory outcome incidence increased from 19.6% in the lowest to 48.9% in the highest RDW tertile with a corresponding risk ratio (RR) of 2.35 ([95%CI:1.08-5.14] P = 0.032) in AAA patients. In the CABG cohort, the incidence of postoperative inflammatory outcomes increased from 1.8% to 5.3% with an adjusted RR of 1.95 ([95%CI:1.02-3.75] P = 0.044) for the highest RDW tertile compared with the lowest RDW tertile. FDG-PET scans showed associations of RDW with tissue activity in the spleen (B = 0.517 [P = 0.001]) and the lumbar bone marrow (B = 0.480 [P = 0.004]). CONCLUSION: Elevated RDW associates with increased risk for postoperative inflammatory complications and hematopoietic tissue activity. RDW likely reflects chronic low-grade inflammation and should be considered to identify patients at risk for postoperative inflammatory complications following cardiovascular surgery.

Engineered 3D Cardiac Fibrotic Tissue to Study Fibrotic Remodeling.

Activation of cardiac fibroblasts into myofibroblasts is considered to play an essential role in cardiac remodeling and fibrosis. A limiting factor in studying this process is the spontaneous activation of cardiac fibroblasts when cultured on two-dimensional (2D) culture plates. In this study, a simplified three-dimensional (3D) hydrogel platform of contractile cardiac tissue, stimulated by transforming growth factor-ß1 (TGF-ß1), is presented to recapitulate a fibrogenic microenvironment. It is hypothesized that the quiescent state of cardiac fibroblasts can be maintained by mimicking the mechanical stiffness of native heart tissue. To test this hypothesis, a 3D cell culture model consisting of cardiomyocytes and cardiac fibroblasts encapsulated within a mechanically engineered gelatin methacryloyl hydrogel, is developed. The study shows that cardiac fibroblasts maintain their quiescent phenotype in mechanically tuned hydrogels. Additionally, treatment with a beta-adrenergic agonist increases beating frequency, demonstrating physiologic-like behavior of the heart constructs. Subsequently, quiescent cardiac fibroblasts within the constructs are activated by the exogenous addition of TGF-ß1. The expression of fibrotic protein markers (and the functional changes in mechanical stiffness) in the fibrotic-like tissues are analyzed to validate the model. Overall, this 3D engineered culture model of contractile cardiac tissue enables controlled activation of cardiac fibroblasts, demonstrating the usability of this platform to study fibrotic remodeling.

Distinct fibrosis pattern in desmosomal and phospholamban mutation carriers in hereditary cardiomyopathies.

BACKGROUND: Desmosomal and phospholamban (PLN) mutations are associated with arrhythmogenic cardiomyopathy. Ultimately, most cardiomyopathic hearts develop significant cardiac fibrosis. OBJECTIVE: To compare the fibrosis patterns of desmosomal and p. Arg14del PLN-associated cardiomyopathies with the pattern in hearts with other hereditary cardiomyopathies. METHODS: A midventricular transversal slice was obtained from hearts of 30 patients with a cardiomyopathy with a known underlying mutation and from 8 controls. Fibrosis and fatty changes were quantitatively analyzed using digital microscopy. RESULTS: Hearts from patients with desmosomal mutations (n = 6) showed fibrosis and fibrofatty replacement in the left ventricular (LV) outer myocardium, mainly in the posterolateral wall, and in the right ventricle. A similar phenotype, but with significantly more severe fibrotic changes in the LV, was found in the PLN mutation group (n = 8). Cardiomyopathies associated with lamin A/C (n = 5), sarcomeric (n = 8), and desmin (n = 3) mutations all showed a different pattern from that of the desmosomal and PLN mutation carriers. The posterolateral LV wall appeared to be the most discriminative area with fibrosis and fatty changes predominantly at the outer compact myocardium in 13 of 14 hearts with desmosomal and PLN mutations (93%), in 0 of 13 hearts with lamin A/C and sarcomeric mutations (0%), and in 1 of 3 desminopathic hearts (33%) (P < .001). CONCLUSION: Desmosomal- and PLN-associated cardiomyopathies have a fibrosis pattern distinct from the patterns in other hereditary cardiomyopathies. The posterolateral LV wall appeared to be the most discriminative region between mutation groups. These results may provide a roadmap for cardiac imaging interpretation and may help in further unraveling disease mechanisms.

Schwannoma of the Recurrent Laryngeal Nerve: A Rare Entity.

Neurogenic tumors are the most common posterior mediastinal tumors in adults. Schwannomas originating from the recurrent laryngeal nerve are rare. The present study describes a 46-year-old man with a tumor in the left superior mediastinum. Because of the narrow relationship with the aorta and the left pulmonary artery, the tumor was excised by left-sided minithoracotomy. The tumor, a schwannoma, originated from and encased the left recurrent laryngeal nerve. Six months after surgery, the patient was free of recurrence without symptoms other than hoarseness. "Additional imaging by magnetic resonance imaging could raise the probability of a neurogenic origin of the mass, eventually leading to collaboration with the neurosurgeon in this case."

Uniform data collection in routine clinical practice in cardiovascular patients for optimal care, quality control and research: The Utrecht Cardiovascular Cohort.

Background Cardiovascular disease remains the major contributor to morbidity and mortality. In routine care for patients with an elevated cardiovascular risk or with symptomatic cardiovascular disease information is mostly collected in an unstructured manner, making the data of limited use for structural feedback, quality control, learning and scientific research. Objective The Utrecht Cardiovascular Cohort (UCC) initiative aims to create an infrastructure for uniform registration of cardiovascular information in routine clinical practice for patients referred for cardiovascular care at the University Medical Center Utrecht, the Netherlands. This infrastructure will promote optimal care according to guidelines, continuous quality control in a learning healthcare system and creation of a research database. Methods The UCC comprises three parts. UCC-1 comprises enrolment of all eligible cardiovascular patients in whom the same information will be collected, based on the Dutch cardiovascular management guideline. A sample of UCC-1 will be invited for UCC-2. UCC-2 involves an enrichment through extensive clinical measurements with emphasis on heart failure, cerebral ischaemia, arterial aneurysms, diabetes mellitus and elevated blood pressure. UCC-3 comprises on-top studies, with in-depth measurements in smaller groups of participants typically based on dedicated project grants. All participants are followed up for morbidity and mortality through linkage with national registries. Conclusion In a multidisciplinary effort with physicians, patients and researchers the UCC sets a benchmark for a learning cardiovascular healthcare system. UCC offers an invaluable resource for future high quality care as well as for first-class research for investigators.

White blood cell count and new-onset atrial fibrillation after cardiac surgery.

BACKGROUND: Postoperative new-onset atrial fibrillation (PNAF) is the most common complication following cardiac surgery. The inflammatory response, as a potential underlying mechanism, has been extensively studied. In small studies, the white blood cell count (WBC) has been shown to be the only consistent inflammatory marker associated with PNAF. This study aimed to determine the association between perioperative WBC response and PNAF in a larger study cohort. METHODS: Patients ≥18years, undergoing elective cardiac surgery with a preoperative sinus rhythm were included. WBC was routinely measured preoperatively, and daily during the first four postoperative days. Main outcomes were the difference between peak postoperative WBC and neutrophil/lymphocyte ratio (N/L ratio) and preoperative WBC and N/L ratio (ΔWBC and ΔN/L ratio respectively). Development of PNAF was evaluated in all patients with continuous 12-lead ECG monitoring. RESULTS: 657 patients were included and 277 (42%) developed PNAF. Univariable analyses showed a statistically significant relationship between ΔWBC (P=0.030) and ΔN/L ratio (P=0.002), and PNAF. In multivariable analysis no significant relationship was found between ΔWBC (OR: 1.14 per 1×109/L increase; 95% CI: 0.65-2.03; P=0.645), ΔN/L ratio (OR: 1.65 per 1×109/L increase; 95% CI: 0.94-2.90; P=0.089), and PNAF. Increasing age (OR: 1.08 per year; 95% CI: 1.01-1.16; P=0.022) and (additional) valve surgery (versus CABG) (OR: 4.96; 95% CI: 2.07-6.91; P≤0.001) were associated with PNAF. CONCLUSIONS: The perioperative WBC response and its components were not associated with the development of PNAF.

A Laser-Assisted Anastomotic Technique: Feasibility on Human Diseased Coronary Arteries.

OBJECTIVE: Atherosclerotic disease might hamper the efficacy of the Excimer laser-assisted Trinity Clip anastomotic connector in coronary arteries. Therefore, its efficacy was evaluated on human diseased coronary arteries (study 1). In addition, the acute laser effects onto the coronary wall were assessed (study 2). METHODS: Thirty-eight anastomoses were constructed on ex vivo human hearts. Atherosclerosis was histopathologically determined and subsequently related to the success of the technique (ie, connector positioning and laser punching; study 1). In addition, 20 anastomoses were constructed in an ex vivo (porcine, n = 8) and an in vivo [rabbit (n = 9) and porcine (n = 3)] model. Subsequently, the coronary was histologically studied on the presence of laser-induced damage (study 2). RESULTS: In 13 of 38 anastomoses (study 1), the connector was malpositioned, 3 because of a severely diseased coronary wall and 10 because of an inner diameter less than the intended target range. The laser-punch success rates on coronary arteries with an early and advanced lesion were 100% (16/16) and 89% (8/9; lesions were located in the inferolateral wall), respectively. In one case, an advanced lesion (ie, fibrocalcified plaque) was located in the superolateral wall and caused a laser-punch failure. No histological signs of laser-induced damage were observed, in case of correct use (study 2). CONCLUSIONS: This study demonstrates the feasibility of an anastomotic connector on human diseased coronary arteries and shows that lasering does not induce coronary wall damage. However, careful selection of the coronary, regarding the target inner diameter and disease status, will prevent construction failures. This connector could facilitate less invasive coronary artery bypass grafting.

Total Arterial Minimally Invasive Direct Coronary Artery Bypass Surgery Facilitated by the Trinity Clip Connector.

OBJECTIVE: This pilot study evaluated the feasibility of total arterial minimally invasive direct coronary artery bypass surgery by using the Trinity Clip anastomotic connector in an acute porcine model. METHODS: In 3 pigs, the left and right internal thoracic arteries (LITA and RITA) were harvested conventionally and the chest closed subsequently. After a left lateral thoracotomy, the coronary target was positioned and stabilized by an endo-starfish and octopus. A free RITA-to-LITA y-graft, with a LITA-to-left anterior descending coronary artery (LAD) and a free RITA-to-obtuse marginal or posterolateral or posterior descending artery, was constructed using the Trinity Clip. Patency was assessed with angiography (n = 3 anastomoses). RESULTS: The anastomotic procedure was feasible via a small lateral thoracotomy, with a fast construction of the y-graft, and successful application of the mounted complex (ie, graft, connector, and laser, temporarily fixated by a fixation clip) onto the LAD. Access to the obtuse marginal artery, posterolateral artery, and posterior descending artery was possible, with successful construction, resulting in patent anastomoses. CONCLUSIONS: This experimental pilot study demonstrates the feasibility of the anastomotic technique in a total arterial minimally invasive direct coronary artery bypass approach. Revascularization of the anterior, lateral, and inferoposterior regions of the heart is possible. However, visibility during the introduction of the connector was limited, and videoscopic assistance is essential to allow for successful construction. The anastomotic technique has potential to facilitate minimally invasive coronary bypass surgery.

Implementation of the third universal definition of myocardial infarction after coronary artery bypass grafting: a survey study in Western Europe.

BACKGROUND: Diagnosing a postoperative myocardial infarction in patients undergoing coronary artery bypass grafting is challenging, as the normally used criteria are more difficult to interpret. The rate of implementation of the consensus-based new diagnostic criteria for postoperative myocardial infarction proposed by the third universal definition of myocardial infarction is unknown. Therefore, the primary objective of this study was to address the implementation of the third universal definition of postoperative myocardial infarction following coronary artery bypass grafting. METHODS AND RESULTS: We conducted a web-based survey by sending 4 waves of invitations via e-mail to cardiothoracic surgeons in 12 Western European countries. Of the 302 participating cardiothoracic specialists, from 182 different centers, 213 (71%) were aware that troponin is the preferred biomarker and 112 (37%) knew that using a cut-off level of >10 times the 99th percentile is recommended. Overall, 90 (30%) participants (strongly) agreed with implementation of this cut-off level in their clinical practice. Troponin was used in clinical practice by 149 (49%) of the participants. In total, 117 (89%) of the 131 participants with a local guideline confirmed ECG changes as a diagnostic criterion in that guideline. ST segmental changes (75, 64%) were used more often for diagnosing postoperative myocardial infarction than Q waves (64, 55%) or new left bundle branch blocks (34, 29%). CONCLUSIONS: Cardiac biomarkers and ECG changes were not used in concordance with the third universal definition, and only a minority had a positive attitude toward implementation of the proposed cut-off level for troponin in their clinical practice.

Mitral valve annuloplasty rings: review of literature and comparison of functional outcome and ventricular dimensions.

In the past decades, more than 40 mitral valve annuloplasty rings of various shapes and consistency were marketed for mitral regurgitation (MR), although the effect of ring type on clinical outcome remains unclear. Our objective was to review the literature and apply a simplification method to make rings of different shapes and rigidity more comparable. We studied relevant literature from MEDLINE and EMBASE databases related to clinical studies as well as animal and finite element models. Annuloplasty rings were clustered into 3 groups as follows: rigid (R), flexible (F), and semirigid (S). Only clinical articles regarding degenerative (DEG) or ischemic/dilated cardiomyopathy (ICM) MR were included and stratified into these groups. A total of 37 rings were clustered into R, F, and S subgroups. Clinical studies with a mean follow-up of less than 1 year and a reported mean etiology of valve incompetence of less than 60% were excluded from the analysis. Forty-one publications were included. Preimplant and postimplant end points were New York Heart Association class, left ventricular ejection fraction (LVEF), left ventricular end-systolic dimension (LVESD), and left ventricular end-diastolic dimension (LVEDD). Statistical analysis included paired-samples t test and analysis of variance with post hoc Bonferroni correction. P < 0.05 indicated statistical difference. Mean ± SD follow-up was 38.6 ± 27 and 29.7 ± 13.2 months for DEG and ICM, respectively. In DEG, LVEF remained unchanged, and LVESD decreased in all subgroups. In our analysis, LVEDD decreased only in F and R, and S did not change; however, the 4 individual studies showed a significant decline. In ICM, New York Heart Association class improved in all subgroups, and LVEF increased. Moreover, LVESD and LVEDD decreased only in F and S; R was underpowered (1 study). No statistical difference among R, F, and S in either ICM or DEG could be detected for all end points. Overall, owing to underpowered data sets derived from limited available publications, major statistical differences in clinical outcome between ring types could not be substantiated. Essential end points such as recurrent MR and survival were incomparable. In conclusion, ring morphology and consistency do not seem to play a major clinical role in mitral valve repair based on the present literature. Hence, until demonstrated otherwise, surgeons may choose their ring upon their judgment, tailored to specific patient needs.

Evaluation of a novel laser-assisted coronary anastomotic connector - the Trinity Clip - in a porcine off-pump bypass model.

To simplify and facilitate beating heart (i.e., off-pump), minimally invasive coronary artery bypass surgery, a new coronary anastomotic connector, the Trinity Clip, is developed based on the excimer laser-assisted nonocclusive anastomosis technique. The Trinity Clip connector enables simplified, sutureless, and nonocclusive connection of the graft to the coronary artery, and an excimer laser catheter laser-punches the opening of the anastomosis. Consequently, owing to the complete nonocclusive anastomosis construction, coronary conditioning (i.e., occluding or shunting) is not necessary, in contrast to the conventional anastomotic technique, hence simplifying the off-pump bypass procedure. Prior to clinical application in coronary artery bypass grafting, the safety and quality of this novel connector will be evaluated in a long-term experimental porcine off-pump coronary artery bypass (OPCAB) study. In this paper, we describe how to evaluate the coronary anastomosis in the porcine OPCAB model using various techniques to assess its quality. Representative results are summarized and visually demonstrated.

Transcatheter aortic valve replacement: postoperative CT findings of Sapien and CoreValve transcatheter heart valves.

Transcatheter aortic valve replacement represents one of the most exciting medical technical developments in recent years, offering a much-needed therapeutic alternative for patients with severe aortic valve stenosis who, due to comorbidities and advanced age, are considered to be inoperable or at high surgical risk. The efficacy of this procedure compared with standard surgical intervention has been properly validated in multicenter randomized controlled trials (PARTNER A and B trials), leading to widespread clinical implementation, with over 50,000 procedures currently being performed worldwide each year. Although much of the attention has rightly focused on the potential role of computed tomography (CT) in the preprocedural assessment of the aortic root and the establishment of imaging-guided valve-sizing algorithms, less is known regarding the postprocedural CT characteristics of transcatheter heart valves (THVs). However, given the increasing worldwide recognition and clinical implementation of these devices, they will no doubt be encountered with increasing frequency in patients referred for thoracic CT, either for postprocedural evaluation of the aortic root or for unrelated reasons. Familiarity with these devices and their CT characteristics will increase diagnostic confidence and the value of the radiology report. The authors describe the physical and imaging properties of the currently commercially available THVs, their normal postprocedural imaging appearances, and potential complications that can be detected at CT. In addition, they discuss the relative strengths and weaknesses of CT and echocardiography in this setting.

Effects of dexamethasone on cognitive decline after cardiac surgery: a randomized clinical trial.

BACKGROUND: Cardiac surgery can be complicated by postoperative cognitive decline (POCD), which is characterized by impaired memory function and intellectual ability. The systemic inflammatory response that is induced by major surgery and cardiopulmonary bypass may play an important role in the etiology of POCD. Prophylactic corticosteroids to attenuate the inflammatory response may therefore reduce the risk of POCD. The authors investigated the effect of intraoperative high-dose dexamethasone on the incidence of POCD at 1 month and 12 months after cardiac surgery. METHODS: This multicenter, randomized, double-blind, placebo-controlled trial is a preplanned substudy of the DExamethasone for Cardiac Surgery trial. A total of 291 adult patients undergoing cardiac surgery with cardiopulmonary bypass were recruited in three hospitals and randomized to receive dexamethasone 1 mg/kg (n = 145) or placebo (n = 146). The main outcome measures were incidence of POCD at 1- and 12-month follow-up, defined as a decline in neuropsychological test performance beyond natural variability, as measured in a control group. RESULTS: At 1-month follow-up, 19 of 140 patients in the dexamethasone group (13.6%) and 10 of 138 patients in the placebo group (7.2%) fulfilled the diagnostic criteria for POCD (relative risk, 1.87; 95% CI, 0.90 to 3.88; P = 0.09). At 12-month follow-up, 8 of 115 patients in the dexamethasone group (7.0%) and 4 of 114 patients (3.5%) in the placebo group had POCD (relative risk, 1.98; 95% CI, 0.61 to 6.40; P = 0.24). CONCLUSION: Intraoperative high-dose dexamethasone did not reduce the risk of POCD after cardiac surgery.

Decreased functional connectivity and disturbed directionality of information flow in the electroencephalography of intensive care unit patients with delirium after cardiac surgery.

BACKGROUND: In this article, the authors explore functional connectivity and network topology in electroencephalography recordings of patients with delirium after cardiac surgery, aiming to improve the understanding of the pathophysiology and phenomenology of delirium. The authors hypothesize that disturbances in attention and consciousness in delirium may be related to alterations in functional neural interactions. METHODS: Electroencephalography recordings were obtained in postcardiac surgery patients with delirium (N = 25) and without delirium (N = 24). The authors analyzed unbiased functional connectivity of electroencephalography time series using the phase lag index, directed phase lag index, and functional brain network topology using graph analysis. RESULTS: The mean phase lag index was lower in the α band (8 to 13 Hz) in patients with delirium (median, 0.120; interquartile range, 0.113 to 0.138) than in patients without delirium (median, 0.140; interquartile range, 0.129 to 0.168; P < 0.01). Network topology in delirium patients was characterized by lower normalized weighted shortest path lengths in the α band (t = -2.65; P = 0.01). δ Band-directed phase lag index was lower in anterior regions and higher in central regions in delirium patients than in nondelirium patients (F = 4.53; P = 0.04, and F = 7.65; P < 0.01, respectively). CONCLUSIONS: Loss of α band functional connectivity, decreased path length, and increased δ band connectivity directed to frontal regions characterize the electroencephalography during delirium after cardiac surgery. These findings may explain why information processing is disturbed in delirium.

Six-month healing of the nonocclusive coronary anastomotic connector in an off-pump porcine bypass model.

OBJECTIVE: This pilot study evaluates the anastomotic healing of the Excimer Laser Assisted Nonocclusive Anastomosis coronary connector at 6 months in a porcine off-pump coronary artery bypass (OPCAB) model. METHODS: Left internal thoracic artery to left anterior descending coronary artery bypass in two animals and left internal thoracic artery to left anterior descending coronary artery and right internal thoracic artery to right coronary artery bypasses in one animal were evaluated intraoperatively and at 6 months. The anastomoses (n = 4) were examined by angiography, intravascular ultrasound, optical coherence tomography, scanning electron microscopy, and histology. RESULTS: At follow-up, all anastomoses (n = 4) were fully patent (FitzGibbon grade A). Scanning electron microscopy demonstrated complete endothelial coverage of the anastomotic surface, and histology showed minimal streamlining intimal hyperplasia. The in vivo intravascular ultrasound and optical coherence tomography acquisitions confirmed histologic findings. Optical coherence tomography demonstrated 0.06-mm intimal coverage of the intraluminal part of the connector along the full circumference of the anastomosis. CONCLUSIONS: In this pilot study, the Excimer Laser Assisted Nonocclusive Anastomosis coronary connector showed an excellent healing response on the long-term in the porcine OPCAB model. Hence, this new concept might be a potential alternative to hand-sutured anastomosis in (minimally invasive) OPCAB surgery.

Secretion of adipocytokines by perivascular adipose tissue near stenotic and non-stenotic coronary artery segments in patients undergoing CABG.

OBJECTIVE: Perivascular adipose tissue (pvAT) may induce a local pro-inflammatory environment, possibly contributing to coronary atherosclerosis. We investigated whether there is a difference in adipocytokine production by pvAT near stenotic and non-stenotic coronary artery segments in patients with coronary artery disease (CAD). METHODS: In patients undergoing CABG with or without valve replacement (n = 38) pvAT near stenotic and near non-stenotic coronary segments was harvested. PvAT was incubated ex vivo for 24h. Concentrations of 23 adipocytokines were measured in the supernatants with a Multiplex assay. The number of macrophages (CD68, CD11c, CD206) and lymphocytes (CD45) in pvAT was determined. Differences between stenosis and control pvAT were tested with Wilcoxon signed rank test corrected for multiple comparisons. RESULTS: Production of IL-5, IL-1α, IL-17, IL-18 and IL-23 was higher in control than stenosis pvAT samples (p < 0.0021). Macrophages were more abundant in stenosis than in control pvAT (median n/400× field: 2.3 IQR: 0.3-4.5 versus 1.2 IQR: 0.1-2.5). There was a predominance of M2 macrophages in both stenosis and control pvAT (median n/400× field: macrophages stenosis: M1: 0.0; M2: 1.0 p = 0.004; control: M1: 0.0; M2: 0.6 p = 0.013). The relation between adipocytokine production and macrophage infiltration was not different in stenosis and control pvAT. CONCLUSION: In patients with CAD, multiple adipocytokines were secreted at higher levels by pvAT near non-stenotic than near stenotic coronary artery segments. Furthermore, pvAT macrophages are associated with stenosis of the adjacent vessel. M2 macrophages were more abundant than M1 macrophages in pvAT.

The nonocclusive laser-assisted coronary anastomotic connector in an off-pump porcine bypass model.

OBJECTIVES: To facilitate minimally invasive coronary artery bypass grafting, a simplified alternative for hand-sutured anastomoses must be developed. We assessed the feasibility and anastomotic healing of the ameliorated Excimer laser-assisted nonocclusive anastomosis coronary prototype connector in an acute rabbit study (study 1) and in a long-term porcine off-pump coronary bypass study (study 2). METHODS: Eighteen anastomoses were constructed on the abdominal aorta of the rabbit. In the porcine model, 15 left internal thoracic artery to left anterior descending coronary artery bypasses were evaluated intraoperatively and at 4 hours, 4 and 10 days, 2, 3, and 5 weeks, and 6 months (each n = 2 anastomoses). The anastomoses were examined by angiography, flow measurements, fractional flow reserve, coronary flow reserve, histologic features, and scanning electron microscopy. RESULTS: In study 1, all 18 anastomoses were patent and resisted supraphysiologic pressures (n = 12, 300 mm Hg). In study 2, the connector enabled nonocclusive and fast (7.7 ± 2.2 minutes, mean ± standard deviation) anastomosis construction. All but 1 of 15 anastomoses (owing to a technical error) were fully patent (FitzGibbon grade A) at follow-up. Histologic examination and scanning electron microscopy demonstrated complete endothelialization of the anastomoses at 10 days. At 6 months, no flow-limiting but streamline-covering intimal hyperplasia was shown (fractional flow reserve, 0.93 ± 0.07 mean ± standard deviation). CONCLUSIONS: The new nonocclusive coronary connector is easy to use, and the long-term results suggest favorable healing and remodeling in the porcine model. After downsizing, this anastomotic device, with its emphasis on zero ischemia and simplified prebounding of vessel walls, has intrinsic potential for minimally invasive off-pump coronary artery bypass surgery.