**11. References**


perfusion, etc, each with their advantages and disadvantages. Cold reperfusion has shown promising results in animal studies and needs further clinical evaluation, while pharmacological interventions may offer a very promising pathway for preventing cerebral

Experimental study of a neuroprotective strategy includes appropriate selection of an animal model, as well as functional indices. Of the available animal models, selection is made with respect to their relevance and feasibility of assessing the parameters of interest. The later are identified in the context of the available data. Investigations of promising neuroprotectvie methods require validation in an experimental model (validation study), use of the method in experimental settings to optimize cerebral protection during CPB and DHCA (performance study) and test its utility during routine cardiac surgery (clinical study). Despite the plethora of experimental and clinical studies, we still require a clearer understanding of the pathophysiologic consequences of HCA. This information will be pivotal in clinical decision-making, including when to initiate circulatory arrest and the

Delayed cell death via apoptotic pathways is of special interest because of the potential for intervention. Although apoptosis is believed to play a part in the cerebral injury, its role has generally been identified through histologic techniques in animal models. These snapshots do not permit a clear delineation of the time-line of apoptosis in the course of HCA. Because it clinical role is not clear, therapies have yet to be designed for the specific purpose of inhibiting apoptosis. Both the cascade of events and identification of pharmacologic agents

Rewarming represents a critical time period, during which any additional harm to cerebral cells might induce permanent injury or even precipitate their death. How rapidly a stable energetic and biochemical homeostasis can be obtained in order to prevent the occurrence of

Optimal perfusion characteristics required to reduce neurologic morbidity remain important issues for experimental study. While there is ample evidence supporting the effectiveness of antegrade perfusion, its optimal delivery and perfusion characteristics remain unclear. Overall, there are still many gaps in our knowledge about how to best study cerebral outcome following DHCA. The wealth of available evidence suggests that investigations require coordinated efforts by multiple research groups, pursuing systematic, multilevel research – spanning from cell cultures, to various animal model systems ranging from

We would like to acknowledge Mr. Alexandros Samolis for his active support in this study.

Almeida OFX, Conde GL, Crochemore C, et al. (2000) Subtle shifts in the ratio between pro-

Ananiadou GO, Drossos GE, Bibou NK, Palatianos MG, Johnson OE. (2005) Acute regional

and antiapoptotic molecules after activationof corticosteroid receptors decide

neuronal injury following hypothermic circulatory arrest in a porcine model.

that can act on molecular mediators require active investigation.

rodents to large animals and ultimately to clinical trials.

neuronal fate. FASEB journal 14:779-790

Interact CardioVasc Thorac Surg., 4, 597-601

injury.

appropriate interval.

secondary injuries remains unclear.

**10. Acknowledgements** 

**11. References** 


**15** 

 *Italy* 

Stefano Nazari

**of Aortic Aneurysms** 

*Foundation Alexis Carrel, Pavia,* 

**New Approaches for Treatment and Prevention** 

Vascular surgery was quite obviously conditioned by the development and evolution of the techniques for vascular anastomosis, started around the beginning of the past century. Apart in fact from few episodic and lucky clinical cases of lateral laceration repair as well as many experimental endeavours of vascular suture, accurately described and illustrated in a detailed historical italian review (Zannini G 1967), before that point in time vascular surgery

Payr first reported device for vascular anastomosis substantially derived from elaboration of the common method for rubber tubing connection (left square) while Carrel triangulation was apparently derived from refinements of gastrointestinal suture (right square).

In 1900 Erwin Payr reported to the German Surgical Society results on animal experiments of the apparently first device for vascular anastomosis, which is essentially based on external legature of vascular stumps over a rigid and absorbable magnesium ring (Payr E, 1900), thus trying to adapting to surgery a method already universally used for coupling floppy/elastic tubing. In spite of its elegance (intima-to-intima facing, absorbable magnesium ring) one of its implicit mechanical limits was already outlined in the original report: elastic retraction of the vascular wall when clamped significantly reduces its diameter, thus making quite difficult to put in place a rigid ring of appropriate diameter. In those very years Alexis Carrel, as well as many others in fact (Zannini G 1967), was focusing his attention on suture techniques, already currently adopted in the gastrointestinal tract, and was able to realize blood-tight, low thrombogenic vascular anastomoses by careful refinements of the needles, threads and techniques for their use

clinical practice was substantially confined to vascular ligature.

Fig. 1. Payr and Carrel pioneering techniques.

**1. Introduction 1.1 Background 1.1.1 The beginning** 

