1. Field of the Invention
The present invention relates to medicine, particularly to clamps used in vascular surgery for occlusion of blood vessels during a surgical operation, such as vascular clamps used in aortic aneurysm repair.
2. Background of the Invention
Vascular clamps are very important in performing operations on blood vessels. Most often they serve for occlusion of a blood vessel by their jaws or other working members, which allows to temporarily stop the blood flow in the operated portion of this blood vessel. So, there are known vascular clamps disclosed in U.S. Pat. Nos. 4,531,519; 5,152,770; 5,282,812.
Dunn and Scarrow in U.S. Pat. No. 4,531,519 disclose a vascular clamp in the form of a tapering, flexible and tubular envelope which is wound around the blood vessel to be occluded and is inflated by air or another fluid.
Bengmark and Persson in U.S. Pat. No. 5,152,770 describe a similar device, which includes a flexible, elongate strip covered on its one side with a plurality of communicating bulbs. The strip is wound around the blood vessel or duct to be occluded and the bulbs are inflated to a pressure serving to occlude the duct. After deflation of the bulbs the strip is removed to allow the duct to re-open. As in previous vascular clamp, the application of the strip or envelope by winding it around the blood vessel and subsequently inflating it until the flow of blood or other body fluid is stopped, is a difficult and time consuming task. For this reason both devices are used in exceptional cases only.
Suarez in U.S. Pat. No. 5,282,812 discloses a vascular clamp in the form of a strip of metal bent into V-shape with its inside surfaces lined with a resilient material. Closing of a vessel is described, whereby the clamp is to be held in a forceps, to be pushed over the vessel to be occluded and pressed onto the vessel, whereupon the forceps is removed. The material of the strip is supposed to keep its shape after removal of the forceps and to maintain the necessary pressure during the operation. The device is provided with means for engaging the forceps jaws after completed surgery for opening the V and for removing the clamp. It is claimed that the strip material would have a positional memory for exerting the necessary pressure after positioning. This would require a different size and material of the device for every size of vessel and blood pressure.
Most of the known vascular clamps have two intersecting arms mounted on a common pivot and provided with clamping jaws at their first ends, as well as with fixing grips at their second ends. Among these are vascular clamps described in Canadian Pat. 1103119 and U.S. Pat. No. 5,624,454.
Muermans and Rivlin in Canadian Patent 1103119 disclose a surgical clamp having two clamping jaws and comprising a soft pad placed over each jaw. Each pad includes two cavities, one of them tightly located over the respective jaw, the second cavity is filled with a fluid or solid and is subsequently sealed. It is claimed that the device clamps the vessel without damage.
Devices described in U.S. Pat. Nos. 3,503,398 and 5,236,437 also have soft members on the inner surface of their clamping jaws to prevent damaging of blood vessel surface. These soft members are adapted to be filled with liquid or gas, see U.S. Pat. No. 5,236,437.
All aforesaid devices serve to cut off a portion of the blood vessel during a surgical operation to prevent the flow of blood over this portion.
Closest to the claimed invention is the “Padded vascular clamp” described in U.S. Pat. No. 5,624,454. Palti and Schnall in U.S. Pat. No. 5,624,454 disclose a vascular clamp for occluding a blood vessel or duct in a human or animal. The vascular clamp includes a pair of pivoting arms with a clamping jaw rigidly attached to a distal end of each pivoting arm. A concave substantially semi-cylindrical chamber is formed in each clamping jaw. The clamping jaws are movable between an open position and a closed position, and are aligned so as to form a substantially cylindrical chamber in the closed position. A balloon is mounted in the concave semi-cylindrical chamber of each clamping jaw. Each balloon includes a substantially semi-cylindrical rigid shell conforming to the concave semi-cylindrical chamber and a thin, elastic material pre-filled with a liquid or gaseous fluid at a predetermined pressure. The balloons are configured to completely surround and occlude the blood vessel or duct in the closed position of the vascular clamp. The rigid shell of each balloon is attached to its associated clamping jaw.
The distinction of this vascular clamp is that its design allows to adjust within a wide range the rate of occlusion of a blood vessel—from simple occlusion of this blood vessel to a complete closure of its lumen.
The suggested vascular clamp has a function different from that of known vascular clamps. It serves to clamp the outer surface of a blood vessel during a surgical operation when a special endovascular stapler for suturing a prosthesis—graft or stent-graft to the wall of a blood vessel, substantially the aorta, in direction from inside to outside via metal staples, is inserted within the blood vessel. Thus the development of the suggested vascular clamp pursues other goals.
An object of the present invention is to provide intra-aortal bending of the ends of staples emerging from an open approach endovascular stapler during a surgical procedure for suturing a prosthesis—graft or stent-graft to the wall of a blood vessel, substantially the aorta.
Another object of the present invention is a secure enclosure of aorta walls by clamping jaws of the claimed vascular clamp to close the possible clearance between the inner surface of clamping jaws and outer surface of the aorta, and prevent at the same time damage of the outer surface of the aorta walls.
Still another object of the present invention is a correction of irregularity in thickness of the aorta walls when applying the claimed vascular clamp.