Coronary Bypass Graft Anastomoses Research Articles

Peroperative epicardial ultrasonography of distal coronary artery bypass graft anastomoses using a stabilizing device. A feasibility study

BackgroundWidespread use of intraoperative epicardial ultrasonography (ECUS) for quality assessment of coronary artery bypass graft anastomoses during coronary artery bypass grafting (CABG) has not occurred - presumably due to technological and practical challenges including the need to maintain stable and optimal acoustic contact between the ultrasound probe and the target without the risk of distorting the anastomosis. We investigated the feasibility of using a stabilizing device during ultrasound imaging of distal coronary bypass graft anastomoses in patients undergoing on-pump CABG. Imaging was performed in both the longitudinal and transverse planes.MethodsSingle-centre, observational prospective feasibility study among 51 patients undergoing elective, isolated on-pump CABG. Ultrasonography of peripheral coronary bypass anastomoses was performed using a stabilizing device upon which the ultrasound transducer was connected. Transit-time flow measurement (TTFM) was also performed. Descriptive statistical tests were used.ResultsLongitudinal and transverse images from the heel, middle and toe were obtained from 134 of 155 coronary anastomoses (86.5%). After the learning curve (15 patients), all six projections were obtained from 100 of 108 anastomoses scanned (93%). Failure to obtain images were typical due to a sequential curved graft with anastomoses that could not be contained in the straight cavity of the stabilizing device, echo artefacts from a Titanium clip located in the roof of the anastomoses, and challenges in interpreting the images during the learning curve. No complications were associated with the ECUS procedure. The combined ECUS and TTFM resulted in immediate revision of five peripheral anastomoses.ConclusionsPeroperative use of a stabilizing device during ultrasonography of coronary artery bypass anastomoses in on-pump surgery facilitates imaging and provides surgeons with non-deformed longitudinal and transverse images of all parts of the anastomoses in all coronary territories. Peroperative ECUS in addition to flow measurements has the potential to increase the likelihood of detecting technical errors in constructed anastomoses.Trial registrationThe study was registered on September 29, 2016, ClinicalTrials.gov ID: NCT02919124.

A new technique facilitating intraoperative, high-frequency echocardiography of coronary bypass graft anastomoses

FIGURE 1. Three-dimensional image of the second-generation prototype of the Echoclip device for visualization of the AP (left) and LR planes (right). The Echoclip device consists of 2 skin supports, 2 and 3,which stabilize the imaging area. Between the skin supports, a cavity, 4, is provided. The cavity may accommodate a bypass graft, an anastomosis, or a coronary vessel. Inasmuch as bypass grafts may vary in size, the distance between the skin supports may vary. Also, the height of bypass grafts may vary. To obtain a good imaging contact between the graft and the transducer, the height of the inner sides of the skin supports may vary. In addition, the cavity allows the transducer to obtain imaging. The device also comprises an aperture for receiving the transducer used together with the device. The device comprises fixing elements to ensure that the transducer is properly secured in the aperture, 1. For obtaining longitudinal and transversal sectional images, the cavity is positioned longitudinally and transThe technical quality of anastomoses during coronary artery bypass grafting is often evaluated by measuring flow rate in grafts using transit time flowmetry. Unfortunately, flow rate and flow waveform are poor indicators of the anatomy of anastomoses. Up to 9% of the anastomoses may have a stenosis of more than 50% not detected by flowmeasuring techniques. A better way to evaluate the anatomy of an anastomosis is 3-dimensional imaging. High-frequency epicardial echocardiography has the spatial and temporal resolution to produce a clear image of the anastomoses, detect intramural vessels, and ensure the optimal place for grafting. (phantom resolution of 6.5–15 MHz transducers is reported in the range of 0.1 to 0.25 mm, with approximately 4-cm penetration depth). On the basis of ex vivo porcine and human hearts, epicardial high-frequency echocardiography has a high sensitivity (0.98) and specificity (1.0) for detection of anastomotic construction errors. Three problems must be overcome in performing epicardial echocardiography on the beating heart:

Do manual assisting maneuvers increase speed and technical performance in robotically sutured coronary bypass graft anastomoses?

Robotic endoscopic coronary artery bypass grafting procedures usually are performed as solo surgery operations. This study aimed to investigate whether manual assistance can reduce suturing times and anastomotic suturing problems in robotic coronary artery surgery. In isolated pig hearts, the right coronary artery was excised from the epicardium as a pedicle. This pedicled vessel, which resembles the internal mammary artery, was sutured to the left anterior descending artery using the daVinci telemanipulation system. The anastomosis was performed in a running fashion using 7/0 Pronova. In group 1 (n = 20), the suture was performed by the console surgeon as a solo operation. In group 2 (n = 20), the anastomosis was assisted by a team member using an endo forceps. The operations were performed by five surgeons of different training levels. The overall anastomotic time was 24 +/- 15 min in group 1 and 22 +/- 12 min in group 2. The difference was not significant. The rate for anastomotic suturing problems (thread rupture, knot formation, sling formation, needle bending) was 8 in 20 (40%) in group 1 and 8 in 20 (40%) in group 2 (no difference). Anastomotic times and anastomotic suturing errors were dependent on surgeon experience. All anastomoses in both groups showed correct suture alignment and were probe patent. In a wet lab model of robotic coronary anastomoses, assisting maneuvers do not decrease suturing speed. Similar suturing quality can be achieved whether the suture is performed in a solo fashion or in an assisted manner.

Computational modeling of vascular anastomoses

Recent development of computational technology allows a level of knowledge of biomechanical factors in the healthy or pathological cardiovascular system that was unthinkable a few years ago. In particular, computational fluid dynamics (CFD) and computational structural (CS) analyses have been used to evaluate specific quantities, such as fluid and wall stresses and strains, which are very difficult to measure in vivo. Indeed, CFD and CS offer much more variability and resolution than in vitro and in vivo methods, yet computations must be validated by careful comparison with experimental and clinical data. The enormous parallel development of clinical imaging such as magnetic resonance or computed tomography opens a new way toward a detailed patient-specific description of the actual hemodynamics and structural behavior of living tissues. Coupling of CFD/CS and clinical images is becoming a standard evaluation that is expected to become part of the clinical practice in the diagnosis and in the surgical planning in advanced medical centers. This review focuses on computational studies of fluid and structural dynamics of a number of vascular anastomoses: the coronary bypass graft anastomoses, the arterial peripheral anastomoses, the arterio-venous graft anastomoses and the vascular anastomoses performed in the correction of congenital heart diseases.

An automatic sutureless coronary anastomotic device: initial results of an animal study.

The efficacy and long-term patency of a new distal anastomotic device (DAD) for the creation of rapid, sutureless end-to-side venous or arterial coronary artery bypass graft anastomoses were tested in a sheep model. The DAD was used on the beating hearts of 34 sheep to create 20 anastomoses between saphenous veins (n = 9) or internal mammary arteries (n = 11) and various coronary arteries. Fourteen conventional hand-sutured anastomoses (7 veins; 7 internal mammary arteries) served as controls. The sheep were sacrificed 1 day, 1 week, and 1, 3, and 6 months after surgery. The immediate patencies of all anastomoses were proven by the rates and pattern of flow. There were no significant differences between the DAD and suture anastomosis groups in presacrifice pulsatility index and occlusion rate. The histomorphometric studies showed complete intimal bridging over the DAD with no significant differences between DAD and suture anastomoses with respect to tissue response, mural injury, inflammation, and adventitial fibrosis. The DAD enables the creation of rapid, efficient, and sutureless venous or arterial coronary anastomoses. The long-term results of histomorphometric studies show that the results with the DAD are comparable with those of conventional hand-sutured anastomoses.

Non-invasive visualization of distal coronary bypass graft anastomoses by electron beam computed tomography: A comparison of two scan protocols

Non-invasive visualization of distal coronary bypass graft anastomoses by electron beam computed tomography: A comparison of two scan protocols