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The first non-scientific report of vascular anastomoses goes back to 300 A.D. when Cosma and Damiano first tried to re-implant a limb using ivory needles and a row flax stitches to suture vessels. Unfortunately, results were not reported, but it is fair to assume the results were very poor since the technique never spread out [].

Arterial hemodynamics play an important role in the genesis and progression of vascular diseases and anastomoses outcome []. Flow dynamics on the vessel bifurcation and on the vascular anastomosis and the mechanical properties of artery wall seem to play an important role in the development of myointimal hyperplasia. Non-physiological or turbulent flow fields like flow stagnation, flow separation, recirculation, as well as intramural stress distributions promote atherosclerotic disease and myointimal proliferation (Fig. 1).

The majority of mathematical models of vascular anastomoses assume that blood flow is laminar, the blood is an incompressible non-Newtonian fluid and conduits, arteries and graft as well, have rigid walls that don’t react to blood pressure.

The hope of any surgeon performing vascular anastomosis is that the vascular reconstruction he is performing will last forever and patients will be once and for all set free from ischemic symptoms. Unfortunately, this rarely occurs mostly because the surgical procedure doesn’t treat the cause of vessel occlusion, such as the atherosclerosis and the atherosclerotic process will probably continue to progress, the anastomosis not being spared. Based on clinical experience, cardiac surgeons know, for instance, that to achieve 100% graft patency at 10 years they should use arterial grafts as conduits on a 3 mm coronary artery with proximal sub-occlusion, without distal disease, with large runoff in patients taking antiplatelet drugs and statins and no hypercoagulability (Fig. 1). On the other hand, 100% of graft occlusion at 10 days occurs when a large vein is anastomosed on 1 mm coronary artery with moderate proximal stenosis, with distal disease and poor runoff, in a diabetic patient taking no drugs. However, in this chapter, we systematically review the elements and parameters clearly affecting the outcome of any vascular reconstruction in order to give a general view of what cardiodiovascular surgeons should take into account in order to give a realistic expectation of anastomosis patency.

Since the beginning of cardiovascular surgery, anastomoses have been performed with hand-held sutures basically based on the principles of suture technique described by Alexis Carrel in 1902 []. Even if in the last 100 years many other techniques have been proposed to join two vessels, the comfort to surgeons in performing a reliable anastomosis with the suture technique and the excellence of its long term results have led to its adoption as the gold standard. Therefore we should ask ourselves if we really need an alternative way to construct the vascular anastomosis. A key element to perform a safe and accurate hand-sutured coronary anastomosis is to have a bloodless operating field and an arrested heart. Surgical environment is becoming more and more challenging since off-pump CABGs and minimally invasive approach have been introduced. Surgeons have to deal with more and more diseased vessels since patient’s age and comorbidities continue to increase. Automated anastomotic technologies will enable the creation of rapid, precise and consistent anastomoses and this perfectly match the surgeon’s needs. We are looking for alternative ways to construct a coronary or any vascular bypass in order to reduce the technical demand, standardise the quality of the surgical procedure, reduce the individual surgical dexterity as a determinant factor for anastomosis outcome and possibly, expediting the procedure and reduce costs of the surgical treatment.

In this chapter we review the most recent technologies allowing the construction of the side-to-end anastomosis between ascending aorta and conduit, either vein or artery. For each device, we describe the technical characteristics (), report the published results of the most important experimental and clinical studies () and conclude the device’s presentation with specific observations that could help the reader to better understand its values and limits ().

In this chapter we review anastomosis devices that allow the construction of end-to-side coronary anastomosis. Several distal devices using different technologies have been developed and are currently under clinical investigation to assess their potential benefits in terms of enabling limited access coronary surgery like totally endoscopic coronary surgery, reducing the technical demand for the anastomosis construction and standardizing anastomosis quality. Some of these devices can be also used with arterial graft, the majority are compatible with beating heart surgery and almost all show good results in terms of early graft patency. All patients receiving distal connectors are under thrombocyte aggregation inhibition with aspirin and/or clopidogrel for at least 1 month after the operation.

Over the past ten years, vascular surgeons have witnessed very few changes in their domain, with the exception of the endovascular treatment of some vascular diseases, probably because they are traditionally conservative adopters of new technologies. However, they are now more receptive than ever to any new devices and procedures that can potentially facilitate their everyday work and increase patients’ benefits. The introduction of minimally invasive techniques for major vascular reconstructions is a potential solution that could both save the vascular surgeon’s core activity and reduce patient trauma. In this context, the medical industry can consistently help the surgeon in dealing with vascular reconstructions that are more and more complex due to the aging population and the increasing number of patients’ comorbidity. Performing standard suture techniques for vascular anastomosis construction by endoscopic means, requires tremendous surgical ability, has a very long learning curb and it is a time consuming procedure. Furthermore, it is a matter of fact that when the surgical procedure becomes very technically demanding the surgical risk increases as well. Therefore, to make the endoscopic approach widely accepted, surgeons need an alternative way to construct vascular bypass in order to reduce the technical demand and speed up the procedure. It is mandatory that the clinical outcome remain the same if not improve.

The most remarkable targets achieved in the last two decades by scientific progress in the domain of the cardiovascular diseases share at least one technical element: the use of metal alloys. Coronary and peripheral stents, endoprostheses and vascular connectors are all made of different metal alloys that are more than biocompatible: these devices are all permanently exposed to the bloodstream and should last for a lifetime.

As it has been illustrated in the previous chapters, there is a great variety of sutureless anastomosis devices and each of these is based on original principles and has its . All have been judged safe and consistent and all show excellent experimental long-term results. For those being the object of clinical studies, preliminary results are very promising. In other words, all the presented devices can potentially succeed and replace the standard suture technique. However, new generations of connectors have introduced new issues to be evaluated including overloading, double loading, skiving of aortic punch, variations in operative techniques and graft movement. Therefore, it is not that easy to establish whether a sutureless device is a valid and safe alternative to suture technique and if it can be widely used.