Method for repairing, augmenting, or replacing a body conduit or organ

Abstract

The umbilical cord is used for grafts in the vascular system or other body conduits, such as the ureter.

Description

A major problem in vascular reconstructive surgery is how effectively to supply blood to organs and tissues whose blood vessels are inadequate either through congenital defects or acquired disorders such as trauma, arteriosclerosis and other diseases. Various techniques and materials have been devised to excise and replace blood vessels, to bypass blood vessels, and to patch, i.e., widen the channel of vessels. Initially arterial homografts (human arteries) were used to restore continuity but limited supply, inadequate sizes, development of aneurysms and atherosclerosis necessitated the search for a better substitute. A great advance was the development of the partially porous and pliable plastic cloth graft.

The following is a list of the various problems which one runs into with artificially made grafts:

1. Infection in a foreign body graft is catastrophic, often leading to hemorrhage, sepsis and death.

2. The inner lining is thrombogenic, predisposed to clotting of the graft and distal embolism of the clot.

3. The rigidity of cloth grafts may result in twisting and kinking, especially in areas of crossing a joint.

4. Because of clotting difficulties, smaller caliber artificial grafts are frequently unsuccessful.

The many problems posed by artificially manufactured prostheses have led investigators again to seek newer and better methods. These include new techniques of "cleaning out" an artery such as carbodissection, widening arteries by dilatation, development of bovine heterografts, creating collagen tubes within the recipient patient for later use as a graft (Silicone Mandrel).

Saphenous veins, both autografts (patient is donor) and allografts or homografts (from another human), are now being used to advantage. However, there are problems of unavailability, small size, non uniform caliber, time required for harvesting, intraluminal valves and easy twisting leading to occlusion. The number of new methods being continually devised attests to the need for a better material.

According to the present invention, the structures of the human umbilical cord are used for grafts in the vascular system or other body conduits such as the ureter, in mammals, particularly primates, including man. At birth, after division from the baby, the cord itself is traditionally discarded. The umbilical cord is composed of a vein and two arteries surrounded by a substance called Wharton's jelly. It varies in length from inches to almost 2 feet. It is highly flexible and strong. Both arteries and the vein are suitable for use in surgery. Composite grafts and patches can be made in various sizes and shapes. A list of uses follows, either as a conduit or as a patch of any kind in the body:

1. Arterial substitute

2. Vein substitute

3. Ureter substitute

4. Common bile duct substitute

5. As an arteriovenous fistula for hemodialysis

6. As a patch to close any visceral or vascular defect, or to wrap around and protect a suture line of any kind.

The umbilical cord may be used fresh or as a stored homograft (frozen or in a preservative). It may require treatment with antibiotics or other chemicals or drugs and x-ray treatment for sterilization. It may be antigenic and require treatment, for example with enzymes, to remove any antigenic substances. The cord may be freeze dried or stored in a cold environment or preserved in other known ways as to be used as an autograft if necessary for the baby whenever needed at a future date. The cord may be somewhat coiled and may require mechanical or chemical techniques to straighten it out if necessary. Cords from premature babies or from early pregnancy can be used (i.e., in smaller vessels).

The advantages of using umbilical vessels as a conduit or a patch are as follows:

1. easy availability

2. marked flexibility

3. marked strength

4. highly smooth, natural inner lining may inhibit clotting

5. less likely to become infected

6. relative lack of antigenicity

7. uniform diameter

8. variable size available for both large and small vessels

9. good length

10. contains 3 vessels each of which can be used

EXAMPLE

The following example illustrates the technique of vascular surgical interposition of the umbilical cord vessel derived from the human, into the abdominal aorta of an animal, for example a dog and a baboon.

The animal, in this case a baboon, was prepared under general anesthesia and sterile conditions for making an abdominal incision. The baboon was prepared and shaved and a longitudinal incision was made in the midline of the abdomen. The incision extended from the xythoid to the pubic area and was carried down through the midline and into the peritoneal cavity. Bleeding vessels were clamped and ligated with 3-0 plyglycollic acid sutures. The peritoneal cavity was entered and the viscera and bowel were explored for any other diseases. The animal was found to be normal. The bowel and viscera were walled off with cloth pads and retractors. The peritoneum overlying the aorta was incised and the aorta immobilized by sharp and blunt dissection. Lumbar arteries were individually clamped and ligated with 3-0 silk suture so that the segment of abdominal aorta extending from the infra-renal arteries to the bifurcation of the aorta was immobilized. The entire segment of abdominal aorta was thus made available for transplant of the umbilical cord. During preparation of the abdominal aorta of the baboon, another investigator had taken the umbilical cord of an infant (human) that had been born two hours prior to the surgical intervention of the baboon. The cord had been delivered and taken in its entirety and transported in sterile saline solution, packed in ice. The purpose of freezing the umbilical cord in ice was to prevent any further decomposition of the cord structure. The cord, prior to insertion, was washed and irrigated numerous times with sterile Collins solution with antibiotics, in this particular instance, 1 percent cephalosporin solution and 25,000 units of bacitracin per liter of solution. The blood was thoroughly washed out from within the vessels of the cord and the cord was also irrigated with a 1 percent heparin anticoagulant solution. Following this thorough cleansing of the cord, one end of the umbilical vein within the cord which was to be used as the transplant was clamped with a clamp and through the other end a red rubber catheter, No. 14 French, was introduced and the vein was distended. At this point a suitable segment of umbilical graft, approximately 5 centimeters in length, was selected for excision. This segment of cord was then sterilely handled and placed into the operating field. At this point the animal was heparinized with 2,500 units of aqueous heparin given intravenously. The abdominal aorta was then clamped proximally and distally to the segment to be resected. A segment of approximately 3 centimeters in length was resected from the abdominal aorta and an end-to-end anastomosis was performed between host aorta and donor umbilical vein, first using continuous 6-0 prolene suture which is a nylon monofilament suture. The distal anastomosis was then performed following flushing of the aorta to rid it of any clot material and debris. Following completion of anastomosis the distal and then the proximal clamps were removed. It was noted that there was no bleeding between the interstices of the sutures, which is unusual, and is felt to be due to the strength and self-sealing gelatinous qualities of the cord structure. Excellent pulses were noted to be present in the graft as well as the distal iliac vessels. The area was lavaged with with saline and suctioned. The retroperitoneum was closed with interrupted 3-0 polyglycollic acid sutures and the viscera was replaced. The animal, throughout the procedure thus far, was stable; the respiration and vital signs were normal. The abdominal wall was then closed in layers using continuous 0 silk for the posterior fascia and peritoneum and interrupted 2-0 silk sutures for the anterior fascia. The skin was approximated with continuous 3-0 nylon suture. The anesthesia used in this procedure was nembutal. The blood loss estimated during the procedure was approximately 50 to 75 cc. The animal tolerated the procedure well and awoke within 30 minutes. Postoperatively on the following day the animal was sitting and walking in its cage, and on the third postoperative day was eating its regular diet and was allowed out of its cage to roam around and climb up and down the walls, and appeared to be in excellent health. The legs were warm and pulses were intact in the extremities.

A number of procedures will become apparent to those skilled in the art. If desired or necessary, the vein or artery of the umbilical cord may be split longitudinally and formed into composites of larger diameter. The umbilical cord or a portion thereof may be used to reinforce, support or seal a weakened area or defect of any body structure, such as the heart, the heart valves or urinary bladder. Such procedures are included within the scope of the claims.

Claims

I claim:

1. A method for repairing, augmenting or replacing a vein or artery of the body of a primate which comprises suturing or otherwise securing a portion of a vein or artery of an umbilical cord of a primate into or onto the wall of such body vein or artery.

2. A method as described in claim 1 wherein the umbilical cord is from a human infant.

3. A method as described in claim 1 wherein an artery of the body is repaired, augmented or replaced.

4. A method as described in claim 1 wherein the cord is from a human and said body is that of a primate other than the donor.

5. A method as described in claim 1 wherein a vein of the body is repaired, augmented or replaced.