Exenatide reduces infarct size and improves cardiac function in a porcine model of ischemia and reperfusion injury.

Objectives: This study sought to examine whether exenatide is capable of reducing myocardial infarct size.

Background: Exenatide is a glucagon-like peptide (GLP)-1 analogue with insulinotropic and insulinomimetic properties. Because insulin and GLP-1 have been described as reducing apoptosis, exenatide might confer cardioprotection after acute myocardial infarction (MI).

Cyclooxygenase-2 inhibition increases mortality, enhances left ventricular remodeling, and impairs systolic function after myocardial infarction in the pig.

Background: Cyclooxygenase (COX)-2 expression in the heart increases after myocardial infarction (MI). In murine models of MI, COX-2 inhibition preserves left ventricular dimensions and function. We studied the effect of selective COX-2 inhibition on left ventricular remodeling and function after MI in a pig model.

S2 connector versus suture: distal coronary anastomosis remodeling, patency, and function in the pig.

Background: Anastomotic connectors could be the key to less invasive bypass surgery, including endoscopic procedures, but equivalence to conventional suturing needs to be established. A novel distal coronary connector was tested pre-clinically for safety and efficacy in comparison to conventional suturing.

Methods And Results: Left internal thoracic to left anterior descending coronary artery bypasses were constructed off-pump in 35 pigs (73+/-8 kg).

Quality assessment of distal S(2)AS connector anastomosis by 13 MHz epicardial ultrasound.

Objective: During application of a distal coronary bypass connector, we employed 13 MHz epicardial ultrasound to evaluate quantitative caliper measurements for vessel size matching and to assess anastomosis quality after connector deployment.

Methods: Two S(2)AS connector anastomoses were constructed on ex vivo pressure-perfused porcine hearts. Epicardial ultrasound measurements of the connector ring and anastomosis were compared to intravascular ultrasound measurement and cast dimensions.

Transmural differences in myocardial function and metabolism during direct left ventricular to coronary artery sourcing.

Background: We investigated the hypothesis that in the absence of collateral circulation, a left ventricle-coronary artery (LV-CA) bypass will maintain normal LV wall function and metabolism transmurally, both at rest and during stress, when the left anterior descending coronary artery (LAD) is acutely occluded proximally.

Methods: In 18 anesthetized pigs (74 +/- 7 kg, mean +/- standard deviation), a covered stent was placed transmurally in the lateral wall of the beating LV and connected to the proximal LAD via an arterial graft. Subepicardial and subendocardial segmental shortening as well as interstitial lactate and glucose concentrations were measured regionally by sonomicrometry and microdialysis, respectively.

Ninety-degree anterior cardiac displacement in off-pump coronary artery bypass grafting: the Starfish cardiac positioner preserves stroke volume and arterial pressure.

Purpose: In off-pump coronary surgery through sternotomy, exposure of posterior circumflex branches causes circulatory deterioration in both patients and pigs. We assessed cardiac pump function when displacing the pig heart anteriorly with a suction cardiac positioner.

Description: Six pigs (+/-80 kg) underwent sternotomy for hemodynamic instrumentation using catheter-tipped manometers and paced at 80 beats/min.

Stapled coronary anastomosis with minimal intraluminal artifact: The S2 Anastomotic System in the off-pump porcine model.

Objective: A reliable, easy-to-use, 1-shot anastomotic device will significantly push the barrier for less invasive coronary bypass surgery. The current study was designed to test the safety, efficacy, and early patency of a novel distal anastomotic device.

Methods: The S2 Anastomotic System (iiTech BV, Amsterdam, The Netherlands) was used in 10 consecutive pigs (73 kg) on a mild antiplatelet regimen.

Briefly occlusive coronary anastomosis with tissue adhesive.

Objective: We assessed the feasibility of a facilitated, briefly occlusive, sutureless coronary anastomosis technique in which side-to-side preglued (octylcyanoacrylate adhesive) bounded walls were opened by a conventional arteriotomy.

Methods: In low-flow (prothrombotic milieu, View Article and Find Full Text PDF

Comparison of normal piglet bladder damage after PDT with oral or intravesical administration of ALA.

5-Aminolaevulinic-acid (ALA) can be used as an alternative drug in photodynamic therapy of the bladder, since the selective formation of protoporphyrin IX (PpIX) in the tumour and the virtual absence of induced skin photosensitivity are theoretically advantageous for clinical use. A preclinical study was performed, using an in vivo normal piglet bladder model, in order to determine the maximum drug and light doses for reversible tissue damage. Various ALA doses were administered either orally or instilled in the bladder and different radiant exposures were applied.

Coronary end-to-side sleeve anastomosis using adhesive in off-pump bypass grafting in the pig.

Background: In the exploration of facilitated coronary anastomosis strategies, we assessed a new octylcyanoacrylate adhesive in combination with a modified end-to-side sleeve anastomosis in off-pump bypass grafting in the pig.

Methods: Sleeve-adhesive anastomoses (n = 20) were evaluated intraoperatively, at 3 days (n = 4), and at 5 weeks (n = 16) in an off-pump, low (< or = 15 mL/min; n = 10) and high flow (approximately 60 mL/min; n = 10) porcine bypass model. All anastomoses were examined by flow measurement, angiography, and histology.

Unconventional vessel wall apposition in off-pump porcine coronary artery bypass grafting: low versus high graft flow.

Objective: Facilitated coronary anastomosis techniques may involve unconventional vessel wall apposition in contrast to standard intima-intima apposition. We assessed the patency, anastomotic thrombus formation, and intimal hyperplasia of unconventional intima-adventitia apposition versus conventional suturing techniques in beating heart coronary bypass grafting under low versus high graft flow conditions.

Methods: The intima-adventitia (n = 28) and conventional anastomoses (n = 28) were evaluated intraoperatively (n = 56), at 4 hours (n = 20), and at 5 weeks (n = 36) in a new off-pump low-flow (n = 28) and high-flow (n = 28) porcine bypass model (< or = 15 mL/min and about 60 mL/min, respectively).

Hemodynamic changes with right lateral decubitus body positioning in the tilted porcine heart.

Background: In beating-heart coronary surgical procedures, exposure of posterior vessels through sternotomy causes cardiac function to deteriorate. We hypothesized that turning the subject to the right lateral decubitus position before cardiac retraction improves exposure of posterior vessels and preserves cardiac pump function on displacement.

Methods: Eight 80-kg open-chest pigs were instrumented with catheter-tip manometers.

Exposure of circumflex branches in the tilted, beating porcine heart: echocardiographic evidence of right ventricular deformation and the effect of right or left heart bypass.

Objective: In off-pump coronary surgery, exposure of posterior vessels via sternotomy causes deterioration of cardiac function. Changes in ventricular geometry, valve competence, and hemodynamics after retraction of the beating heart were studied. Subsequently, the modifying effect of right or left heart bypass was investigated.

A novel one-shot anastomotic stapler prototype for coronary bypass grafting on the beating heart: feasibility in the pig.

Objective: The nonpenetrating, arcuate-legged clip has proved its ability to provide a high-quality microvascular anastomosis. This study assessed the feasibility of constructing a coronary end-to-side anastomosis on the beating heart with a novel mechanical, sutureless anastomotic device that applies 12 circumferential clips simultaneously.

Methods: In 14 consecutive pigs (70-90 kg), the left internal thoracic artery (diameter, 3 mm) was grafted to the left anterior descending coronary artery (diameter, 3 mm) by means of a one-shot anastomotic stapler prototype.

Temporary luminal arteriotomy seal: II. Coronary artery bypass grafting on the beating heart.

Background: This study assessed the feasibility of applying a temporary luminal arteriotomy seal during end-to-side coronary artery bypass grafting on the beating heart.

Methods: In 18 consecutive pigs, the left internal mammary artery was grafted to the left anterior descending coronary artery, and the arteriotomy was temporarily sealed luminally by a 200-microm-thick polyurethane seal. Endothelial denudation, medial necrosis, and intimal hyperplasia were measured quantitatively and compared with conventionally sutured anastomoses (n=4 pigs).

Vertical displacement of the beating heart by the octopus tissue stabilizer: influence on coronary flow.

Background: In beating heart coronary artery bypass graft operations, biventricular pump failure, as observed after exposure of the posterior circumflex branches by sternotomy, may originate from mechanical obstruction to coronary flow.

Methods: Regional coronary blood flow was measured in 8 anesthetized, paced, beta-blocked pigs, and the beating heart was fully retracted.

Results: Displacement decreased cardiac output from 4.

Temporary luminal arteriotomy seal for bypass grafting.

Background: To enable off-pump coronary operations in a bloodless surgical field without ischemic complications, we developed and assessed a temporary luminal arteriotomy seal in a porcine carotid artery bypass graft model.

Methods: In 16 consecutive pigs (25 kg, 32 anastomoses) the arteriotomy was sealed luminally by a polyurethane elliptic convex seal. Endothelial denudation, medial necrosis, and intimal hyperplasia were measured quantitatively and compared with those seen in conventionally sutured anastomoses.

Ultrasonography in acute interstitial laser irradiation of the pig brain: preliminary results.

In this preliminary study, the use of real-time ultrasonography to visualize the effects of acute interstitial Nd:YAG laser irradiation was investigated in the normal pig brain. In six pigs, a craniotomy was performed. In the frontal or temporal lobe, a thermal laser lesion was made using a 600-micron-diameter optical fiber at powers of 1 W, 2 W, and 4 W with exposure times of 5 min and 10 min.

The effect of elevated arterial free fatty acid concentrations on hemodynamics and myocardial metabolism and blood flow during ischemia.

In the present investigation the effect of elevated arterial free fatty acid (FFA) concentrations on regional myocardial blood flow (MBF), myocardial metabolism and hemodynamics during ischemia was studied in anesthetized dogs. Ischemia was induced by stenosis of the left interventricular coronary artery. Mean poststenotic coronary artery pressure was kept constant during ischemia.

In vivo cinematographic analysis of behavior of the aortic valve.

In open-chest dogs direct-cinematographic high-speed recordings of aortic valve movement were made using a thin flexible fiberscope. Simultaneously ECG, ascending aortic flow (electromagnetically), and the pressures in the aorta, left ventricle, and left atrium were recorded. Replacement of blood by a transparent liquid (Tyrode solution) was done with two roller pumps, one connected to the left atrium and the other to the femoral artery.