The present invention relates to the field of the ar concerning vascular grafts. The invention introduces the us of a special graft for the replacement of the aortic arch an of the upper abdominal ascending aorta. THE PRIOR ART

None of the currently used techniques utilizes vascula grafts similar to the one proposed by the present invention.

The Aorta is the duct which transports blood from th heart to the organs. It is widely known that all the importan visceral arteries originate from the part of the aorta betwee the abdomen and the thorax. Such visceral arteries suppl blood to the liver, the kidneys, the spleen etc. This is quit important because the blood circulation in "noble* organs (th spleen, the liver, the pancreas, the stomach, the kidneys, th small and the large intestine) should not be stopped durin surgical operations. It has been proved that the time perio between the interruption of blood circulation in a"noble"orga and the final necrosis of the organ is strictly limited. Fo the liver, for example, this period can be less than 3 minutes.

However, current techniques dealing with the problem o rapid visceral revascularization are rather ineffective whe the said organ is not supplied with blood by a visceral arter originating from a healthy area on the walls of the aneurys

(cuff). Specifically, currently used solutions involve t anastomosis of each and every visceral artery (e.g. t classic tubular graft transplantation), which is a ti consuming operation often resulting in the necrosis of t organ, followed by the inevitable death of the patient.

Moreover, even in cases where the above problem i possible to be solved by the preservation of the part of th wall of the aneurysm carrying the orifices of the viscera arteries, the remaining part of the aneurysm (which i usually pathological) will probably cause new problemati situations in the future.

All the above, evidently, constitute dangerous drawback as to the effectiveness of the described methods, as well a dangers concerning the life span of this therapeuti technique.

It is therefore an object of the present invention to dea with the drawbacks and disadvantages of the techniques of th prior art. The proposed solution is a special vascular graf and a method for its rapid plantation, so as to achieve th practically immediate visceral revascularization, providin blood supply to the organs that are very sensitive t prolonged ischaemia ( noble organs ), during surgica operations for the replacement of the aortic arch and/or th upper abdominal ascenting aorta.

In accordance to a preferred embodiment of the invention specially designed artificial graft is used for th replacement of the upper abdominal ascending aorta. On it

upper end, which is inserted in the proximal aortic stump, t proposed graft bears a hard ring and a semi-rigid flap. T inferior part of the graft can be bifurcated for anastomosi to the iliac and/or the femoral arteries and into the mai arteries which are necessary to be revascularized. corresponding form of vascular graft is proposed for t replacement of the aortic arch.

All the characteristics and advantages of the prese invention are explained in depth in the following detaile description. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be made apparent to those skilled i the art by reference to the accompanying drawings, whic depict illustrative and not confining embodiments of th invention.

Figure 1 illustrates an indicative perspective view of th proposed graft for the replacement of the abdominal aorta.

Figure 2 illustrates an indicative perspective view of th above illustrated graft connected with the abjacent viscera arteries.

Figure 3 illustrates an indicative perspective view of th graft used in accordance to the present invention for th replacement of the aortic arch. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The following paragraphs contain an indicative descriptio of preferred embodiments of the present invention, made reference to the accompanying drawings.

Figures 1 and 2 illustrate an indicative embodiment of t abdominal aorta graft 1 proposed in the present invention. T proposed graft is made of DACRON, or any other suitabl material, and has the form of a cylindrical duct 2 with diameter of about 20-24 mm and a length varying according t the physical proportions of the patient's body. The graf extends between an upper (proximal) orifice and a lowe orifice 10. The upper end 9 of the graft is provided with rigid ring 4 and is inserted in the proximal stump 1 following division of the aneurysm. There it is secured by a appropriate stitch 11 forming an intravascular graft. T protruding semi-rigid part 3 of the graft extends upwards i the stump securing and stabilizing the joint. For maximu endurance of the joint, this extension may be secured on th walls of the aorta by stitches.

The cylindrical body 2 of the graft bears a number o branches positioned lengthwise in locations corresponding t those of the arteries to be revascularized. The number of th latter determines the number of the branches of the graft. Th graft 1 is illustrated with an indicative number of fou branches. The first branch (from top to bottom) is used fo anastomosis with the celiac artery and is 5-8 mm in diamete and 5 cm in length (measured from the internal surface of th graft). The distance of the first branch 5 from the rigid rin 9 may vary. The second branch 6 which will be connected to th superior mesenteric artery is 8-9 mm in diameter, 5 cm i length (measured as above) , and orginates 8-10 mm from th

origin of the overlying first branch 5. Whilst the branche for the celiac and the superior mesenteric arteries ar located one below the other in the same vertical plane, th next two branches 7 and 8 which serve the needs o the two renal arteries, are located in facing positions underneath and at an angle to the above. Each of the tw branches 7 and 8 supplying the renal arteries is about 7 mm i diameter and its free edge extends 5 cm from the interna surface of the graft whilst each one of them originates at position 1-2 cm below the origin of the branch supplying th superior mesenteric artery. The inferior end 10 of the graf may divide into anastomotic branches for the ileal or th femoral arteries. According to a preferred embodiment of the invention al the branches end up into rigid tapered plastic orifices These orifices, illustrated as items 5a, 6a, 7a, and 8 respectively can be rapidly inserted into the correspondin orifices of the arteries from the inside of the aneurysm right after the conclusion of the proximal anastomosis thereby restoring the blood supply to the viscera in time.

The introduction of the described graft proposes ne surgical techniques, which will utilize the advance characteristics of the graft, achieving the immediat restoration of blood supply, in organs which are sensitive t prolonged ischaemia.

Specifically, the proposed new technique consists of th following stages:

Insertion and securing of the upper end of the graft in the proximal stump of the aorta after the division of t aneurysm. Localization of the visceral arteries followed anastomosis with the branches of the graft, resulting in t restoration of blood supply to the viscera. The abovemention connection is achieved with the following operations: first, the convergent orifices mentioned in the abo paragraphs are inserted into the corresponding orifices of t arteries. Then, the convergent orifices are secured into t arteries by an appropriate tape, surrounding the joint. Th achieves the practically immediate restoration of blood supp to the viscera. The full anastomosis of the arteries to t corresponding visceral branches of the artificial graft then possible, while blood circulation in the vessels completely normal.

Figure 3 illustrates another proposed graft according the invention, which is intended to replace the ascendi aorta and the arch of the aorta 13. The graft is made of a suitable material, e.g. DACRON, and is an arch like be cylindrical duct 14 with a proximal and a distal end, 15 a 16, respectively. The graft extends to a length of abo 12 cm, whereas the diameter of its proximal orifice 15 25-30 mm and the diameter of its distal orifice 16 is 18- mm. The proximal end 15 of the graft is provided with a rig connection ring 17 and, if necessary, an artificial or oth type of valve 18 for the replacement of the aortic valve.

The branches of the proposed graft 13, which originat along the superior surface of the cylindrical duct 14 are th following: a) The graft 19 replacing the innominate artery. I originates 5-6 cm from the rigid ring 17 and extends to length of about 5 cm, whilst its diameter is about 13 mm an its edge bears a convergent orifice of gradually decreasin diameter 19a. b)The graft for the replacement of the lef common carotid artery 20. It originates at a distance of 3- cm from the innominate artery graft 19, and ends up at convergent orifice 20a similar to the above. Its length an diameter are 5 cm and 9-10 mm respectively.c) The subclavia artery graft 21 which originates at a distance of 3-4 cm fro the common carotid graft 20. This is about 5 cm long, has diameter of about 9 mm and ends up in a convergent orific similar to the ones described above.

It should be noticed that the above description an examples are indicative and do not limit the possibl applications of the invention. Consequently, any modification or alteration in the shape, size and dimensions of the grafts as well as any other changes in the materials and parts use in the described applications, as long as they do no constitute an inventive step, are considered to be part o the scope and aims of the present invention.