Perfusion system

Details Perfusion system Perfusion system

1999-07-20

2001-09-11

Mendez, Manuel (Department: 3763)

Surgery

Means for introducing or removing material from body for...

Material introduced into and removed from body through...

C604S096010

Reexamination Certificate

active

06287273

ABSTRACT:

TECHNICAL FIELD
The present invention relates to a system and a method for non-surgical perfusion of an organ in a living being, in particular non-surgical perfusion of a liver.
BACKGROUND
Treatment with systemic chemotherapy is one of the presently used possibilities in cancer treatment. However, substances that are effective in this kind of treatment are often harmful to the system of the body as a whole. Particularly, the treatment of cancer of the liver presents a serious clinical problem, and the success rate when treating liver cancer is today very low.
Although primary liver cancer (hepatoma) is rather uncommon in northern Europe and United States, hepatoma is prevalent in other parts of the world, e.g. in Southeast Asia, Japan, the Pacific Islands, Greece, Italy and parts of Africa. Also, many patients with cancer in the gastrointestinal tract develop isolated hepatic metastases, since the liver is the primary target for dissemination. Due to the distribution of the metastases within the liver, only few patients with liver cancer can be cured by resection.
Liver cancer is today mainly treated with systemic chemotherapy. However, no substantial increase in the time of survival of the patients is following this treatment (L. M. De Brauw
“Isolated liver perfusion. An experimental modality in the treatment of hepatic metastases.”
Thesis, University of Leiden, Leiden, The Netherlands.). A reason for these discouraging results seems to be the fact that the toxicity of the chemodrugs limits the possible dosage due to the systemic effects. Local administration by infusion in the hepatic artery does not solve this problem, since the chemodrugs are distributed in the system also during this procedure.
STATE OF THE ART
In order to administrate therapeutic drugs locally it has been suggested to perform perfusion of selected organs.
In EP-0 364 799 to BGH Medical Productions, which is hereby incorporated by reference, a process of perfusing a high concentration of an agent through an organ is described. The agent is infused arterially in the organ and on the venous side of the organ the blood is removed from the body using a specially designed double balloon catheter. In this process there is a leakage to the systemic blood flow, since there are numerous blood communicating vessels besides the main artery and the main vein.
A similar catheter is used in the U.S. Pat. No. 5,817,046 to Glickman et al., which is hereby incorporated by reference, showing a system for perfusion of the pelvic cavity. The pelvic cavity is isolated between a double catheter, placed in the iliac vein, and bilateral thigh tourniquets. The thigh tourniquets, which are used to restrict the flow of blood between the legs and the pelvic cavity of the patient, limit the time during which perfusion can be performed.
In U.S. Pat. No. 4,714,460 to Calderon, which is hereby incorporated by reference, feedback methods and systems for retrograde perfusion in the body are described. A double balloon concentric catheter, with an inner infusion lumen and an outer suction lumen, is used for perfusion of the venous side of the vascular network. The therapeutic agent for treatment is infused inside the vein in the opposite direction with respect to the ordinary blood flow, also called retrograde incision. The described method is, thus, designed to operate in back pressure and the perfusion fluid is continuously diluted by arterial blood.
U.S. Pat. No. 4,883,459 to Calderon, which is hereby incorporated by reference, describes a method for perfusion where a carrier medium dye is injected into the tumor. The flow of the dye is monitored to determine an optimal retrograde perfusion path through the tumor.
A balloon catheter with closed tip and device for perfusion with such catheters, are described in U.S. Pat. No. 5,746,717 to Aigner, which is hereby incorporated by reference. The catheter has at least one contrast marking which enables the position of the catheter inside the body to be determined.
The perfusion processes and apparatuses described above all include the return of the blood, which has been contaminated with drugs, to the systemic circulation. This requires treatment to remove the contaminants before this blood can be returned to the body.
An assembly for hepatic isolation and perfusion is described in U.S. Pat. No. 4,192,302 to Boddie, which is hereby incorporated by reference. This assembly allows the blood from the intestines and the lower parts in the patient's body to flow unimpeded through a plurality of shunts. Meanwhile, the blood in the isolated liver is circulated using a heart-lung machine, which allows cancericidal doses of drugs to be delivered to liver cancers essentially without systemic effects. However, the procedure involved is complicated and the large operation, which is needed to place the shunts, only permits perfusion once inter alia due to scars in the tissues and the severe stress on the body of the patient.
Consequently, a drawback with some of the above mentioned, earlier procedures for organ perfusion is that the organ may not be isolated in a perfusion circuit, thus, perfusion fluid may easily leak into the systemic circulation. Another drawback is that blood, which is used to perfuse the organ, may after perfusion contain therapeutic agents, and thus, needs to be purified before it is returned to the body. In the case of a surgical method, as the one described in U.S. Pat. No. 4,192,302, it is a disadvantage that the perfusion can only be performed once on each patient due to the large operation involved. A particular disadvantage with the prior art occurs when there is a considerable fraction of the blood flow that does not enter or leave the organ through the main input and output blood vessels, which for example is the case in the liver, and there is a risk for leakage of perfusion fluid through these minor vessels to the systemic circulation. The venous side of the liver is close the heart, thus leakage of drugs to the system would potentially very fast cause harm.
OBJECT OF THE INVENTION
The object of the present invention, and the problem to be solved, is to provide a system for a minimally invasive perfusion of an organ and a method for minimally invasive perfusion, in other words a system and a method for non-surgically isolating and perfusing an organ. A particular object is to provide such a method and system that allow for a prolonged and increased therapeutic effect. Another object and an aspect of the problem to be solved is to decrease the risk of leakage of therapeutic agents, being locally delivered to an essentially isolated organ in a dosage which is harmful for the body as a whole. A further object and aspect of the problem is to provide a method and a system for easily maintaining and controlling flows and pressures of the blood and perfusion fluid in the organ to be perfused and in the body as a whole.
SUMMARY OF THE INVENTION
The object of the invention is achieved by a system and a method for isolating and perfusing an organ, wherein the main inflow as well as the outflow, vessels of the organs are blocked by means of percutaneously introducible occlusive seals. In addition to the occlusive seals, percutaneously introducible passages or conduits preferably in the form of catheters are placed in the main inflow and outflow vessels in order to establish a shunted blood flow for bypassing the normal blood flow of the organ as well as in order to establish an open or a closed circuit for circulating a perfusion fluid.
The invention is based on the inventor's realization that, for this kind of operation to be efficient in terms of repeatability and of sparing the patient unnecessary stress that diminishes the positive effect of the treatment, the operation has to be carried out non-surgically. This has been made possible by means of percutaneous catheter technology and specifically designed catheters and perfusion equipment in accordance with the invention.
The important advantages of the invention is that the perfusion treatment is invasive to a minimu

Affiliated with

Also associated with

Rating

Perfusion system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Perfusion system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Perfusion system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2472100