LOCAL DRUG INFUSION CATHETER FIELD OF THE INVENTION

The present invention relates to a catheter for local drug infusion. More specifically, it comprises a catheter with the proximal and distal sealing portions that form a chamber to potentialize the infusion of medication into an arterial wall.

BACKGROUND OF THE INVENTION

A balloon catheter is a catheter with an inflatable balloon at one end which is placed on the lesion level inside the coronary artery, said balloon being inflated so as to compress the atherosclerotic plaque against the vessel wall increasing its luminal area and improving the passage of blood to the heart muscle. The primary objective of the balloon dilation of arterial occlusive lesions is obviously to increase the diameter of the arterial lumen enough to restore the adequate tissue perfusion. After defining the arterial puncture site, the artery is catheterized while the patient is anticoagulated. The balloon catheter is then introduced over the guide wire. Next, the balloon is inflated at the site of stenosis or occlusion.

Balloon catheters differ in the material of the balloon, the presence of a friction-reducing coating on the balloon, the balloon inflation mechanism, the length of the catheter tip which extends beyond the balloon, and the length of the balloon body. The diameter of the inflated balloon must be about 10 to 20% larger than the normal lumen of the vessel to be dilated.

Balloon catheters were first manufactured using polyvinyl chloride (PVC), but they were very yielding, which resulted in lesser pressure

when inflated, and had a tendency to dilate beyond the desired diameter. At present, the balloon catheters are less yielding and are manufactured from polyethylene and its subproducts, polyester and interlaced Dacron fibers. The technical literature feature balloon catheters that perform local drug infusion. However, these conventional balloon catheters do not seal the proximal and distal portions of the balloon so as to concentrate the released medication in a coronary artery wall. Additionally, the contact of the balloon with the blood vessel wall augments the resistance to the passage of medication from the inside of the balloon to the vessel wall, thus increasing even more the leakage of the drug into the proximal and distal portions of the balloon. The leakage of medication proximal of the balloon may promote the formation of clots, and the distal leakage - the infusion of doses higher than necessary with its possible adverse effects.

Therefore, there is still a need to provide a drug infusion catheter with the proximal and distal sealing in order to potentialize the infusion of medication into the arterial wall. Such catheter for local drug infusion is described and claimed in this application.

SUMMARY

In the first embodiment, this invention refers to a local drug infusion catheter that comprises a three-lumen catheter having an occluding balloon disposed in the proximal portion, an infusion balloon disposed in the distal portion, and openings on the catheter surface disposed between the occlusion balloon and the infusion balloon for

distal infusion of saline solution.

In the second embodiment, a local drug infusion catheter comprises a one-lumen catheter fitted with an infusion balloon that has an elongated body, and, whose ends are provided with symmetric protrusions which come into contact with the coronary artery wall, and a medial portion with a depression, creating a chamber between the surface of the medial portion of the infusion balloon and the artery wall, said chamber being sealed in the distal and proximal portions by the protrusions disposed on the ends of the infusion balloon. In the third modality, a local drug infusion catheter comprises a three-lumen catheter with one occlusion balloon in the proximal portion and one occlusion balloon in the distal portion, there being openings disposed on the catheter surface between the proximal and the distal occlusion balloon. A local drug infusion catheter that has the proximal and distal sealing and forms a chamber between the balloon and the coronary artery wall is a characteristic feature of this invention, said chamber being filled with medication when the balloon is inflated in order to concentrate and potentialize the release of medication into the coronary artery.

A local drug infusion catheter that occupies less area, when in contact with the artery surface, thus minimizing the damage to the arterial wall endothelium caused by the inflation of the infusion balloon is a characteristic feature of this invention. A catheter that has a compliant occlusion balloon inflated at low pressure, which causes negligible endothelial damage, is a characteristic feature of this invention.

A local drug infusion catheter that significantly reduces the

possibility of generating clots and the dispersion of medication in the circulation, after obstructing the arterial lumen, and, consequently, interrupting temporarily the blood flow, allowing the arterial segment distal to the occlusion balloon to be washed with saline solution, and releasing medication only on the sides is a characteristic feature of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig.1 is a view of the catheter.

Fig.2 is a view of the catheter positioned inside the artery showing the release of medication.

Fig. 3 is a detailed view of the infusion balloon and the release of fluid medication into the artery wall. Fig. 4 is a view of the catheter described in the second embodiment, placed inside the artery showing the release of medication.

Fig.5 is a detailed view of the infusion balloon and of the release of fluid medication into the artery wall. Fig.6 is a view of the catheter of the third embodiment.

Fig.7 is a view of the catheter of the third embodiment positioned inside the artery showing the formation of the chamber and the release of medication.

DETAILED DESCRIPTION OF THE INVENTION

In the first embodiment, the local drug infusion catheter, subject matter of this invention, comprises a three-lumen catheter (10).

The first lumen (11) serves to inflate the proximal occlusion

balloon (20) and to stop the blood flow from passing to the arterial segment to be treated.

The second lumen (12) allows the segment into which the medication will be infused to be washed with saline solution (removal of blood) by infusing saline solution through the openings (15) into the portion between the occlusion balloon (20) and the infusion balloon (30). The washing of the artery (100) avoids trapping blood in the compartment created by the infusion catheter and the interaction of the medication with static blood, which makes possible the formation of blood clots and the reduction in the penetration of medication into the vessel wall.

The third lumen (13) makes possible the infusion of medication into the coronary artery wall (100) by inflating the infusion balloon (30), and the consequent formation of a medication-filled chamber between the infusion balloon (30) and the coronary artery wall (100), said medication that penetrates the arterial wall by a difference in the concentration. The infusion balloon (30) has openings (31 ) in the medial portion and prevents medication from leaking into the portions proximal of or distal to the infusion balloon, thus avoiding a waste and unnecessary administration of medication with its possible adverse effects.

The local drug infusion catheter comprises a three-lumen (11 , 12, and13) catheter (10) that has an occlusion balloon (20) in the proximal portion, which, when inflated, seals the passage of blood to the arterial segment distal to the occlusion balloon (20); and an infusion balloon (30) in the distal portion for local administration of medication through the openings (31 ) disposed on the surface of the infusion balloon (30), said infusion balloon (30) that has a geometric shape and forms a

chamber (50) between the infusion balloon (30) and the wall of the coronary artery (100) to be filled with medication when said infusion balloon (30) is inflated; and the openings (15) on the surface of the catheter (10) disposed between the occlusion balloon (20) and the infusion balloon (30) for the purpose of allowing the distal infusion of saline solution in order to wash the artery (100) and avoid clots in the arterial lumen.

The infusion balloon (30) has an elongated shape and its ends are provided with symmetric protrusions (32) that come into contact with the wall of the coronary artery (100), and the medial portion with a depression (33) that avoids the contact of the surface of the infusion balloon (30) with the artery wall (100) creating a chamber (50) between the surface of the infusion balloon medial portion (33) and the artery wall (100), said chamber (50) being sealed in the distal and proximal portions by the protrusions (32) disposed on the ends of the infusion balloon (30).

The chamber (50) is filled with medication that penetrates the artery wall (100) by a difference in the concentration allowing the infusion of the fluid medication. The surface of the medial portion (33) of the infusion balloon (50) is provided with permeability that allows the fluid medication to flow towards the chamber (50) formed between the surface of the medial portion (33) of the infusion balloon (30) and the wall of the coronary artery (100). The occlusion balloon (20) and the infusion balloon (30) are preferably of polymeric material such as, but not limited to, polyester, polyamide, polyurethane, polytetrafluorethylene and polyolephines or copolymers.

The local drug infusion catheter is introduced and positioned at the site chosen by a surgeon. The occlusion balloon (20) is then inflated to seal the passage of blood distal to the occlusion balloon (20). Next, saline solution is injected into the arterial segment distal to the occlusion balloon (20) through the openings (15) disposed on the catheter (10) between the occlusion balloon (20) and the infusion balloon (30). The infusion balloon (30) previously positioned at the site to be treated is inflated, its medial portion being lowered (33), positioned in the arterial segment into which medication is locally infused, and the protrusions (32) sealing the proximal and distal portions, forming a chamber (50) where the fluid medication is dissipated, and, later on, penetrates inside the arterial wall (100) by a difference in the concentration and pressure.

In the second embodiment, as shown in the Fig. 4 and Fig.5, the local drug infusion catheter, subject matter of this invention, comprises a one-lumen (13) catheter (10) fitted with an infusion balloon (30) that has an elongated shape, and, whose ends are provided with symmetric protrusions that come into contact with the wall of the coronary artery (100), and the medial portion with a depression (33) that prevents the surface of the infusion balloon (30) from being in contact with the artery wall (100), thus creating a chamber (50) between the surface of the infusion balloon medial portion (33) and the artery wall (100), said chamber (50) being sealed in the distal and proximal portions by the protrusions (32) disposed on the ends of the infusion balloon (30).

The infusion balloon (30) has openings (31 ) in the medial portion and prevents medication from leaking into the portions proximal of and distal to the infusion balloon, avoiding a waste and unnecessary

administration of medication with its possible adverse effects.

The chamber (50) is filled with medication that penetrates the artery wall (100) by a difference in the concentration allowing the infusion of the fluid medication. The surface of the medial portion (33) of the infusion balloon (30) is provided with permeability that allows the fluid medication to flow towards the chamber (50) formed between the surface of the medial portion (33) of the infusion balloon (30) and the wall of the coronary artery (100). The infusion balloon (30) is preferably of polymeric material such as, but not limited to, polyester, polyamide, polyurethane, polytetrafluorethylene, and polyolephines or copolymers.

The local drug infusion catheter is introduced and positioned at the site chosen by a surgeon. The saline solution is then injected into the artery to be treated by means of the guide catheter. The infusion balloon (30) previously positioned at the site to be treated is inflated, its medial portion (33) being lowered, positioned in the arterial segment into which the medication is locally infused, and the protrusions (32) sealing the proximal and distal portions, thus forming a chamber (50) where the fluid medication is dissipated, and, later on, penetrates inside the arterial wall (100) by a difference in the concentration and pressure.

In the third embodiment, as shown in the Fig. 6 and Fig.7, the local drug infusion catheter, subject matter of this invention, is a three- lumen catheter (10).

The first lumen (16) serves to inflate the proximal occlusion balloon (60) and stop the blood flow from passing to the arterial segment to be treated.

The second lumen (17) allows saline solution and medication to be infused through the openings (19) disposed on the portion between the proximal occlusion balloon (60) and the distal occlusion balloon (70). The third lumen (18) serves to inflate the distal occlusion balloon

(70), thus forming a chamber (50) between the proximal occlusion balloon (60) and the distal occlusion balloon (70) and the wall of the coronary artery (100), said chamber (50) being filled with fluid medication that penetrates the arterial wall (100) by a difference in the concentration.

The local drug infusion catheter comprises a catheter fitted with three lumens (16, 17, and 18) that has a proximal occlusion balloon (60), a distal occlusion balloon (70), and openings (19) disposed on the surface of the catheter (10) between the proximal (60) and the distal occlusion balloon (70) for the release of fluid medication.

A chamber (50) is formed in the interspace between the proximal (60) and the distal occlusion balloon (70), when they are inflated, and the coronary artery wall (100), said chamber (50) being filled with fluid medication that penetrates the artery wall (100) by a difference in the concentration, allowing the infusion of fluid medication.

The proximal occlusion balloon (60) and the distal occlusion balloon (70) are preferably of polymeric material such as, but not limited to, polyester, polyamide, polyurethane, polytetrafluorethylene, and polyolephines or copolymers. The local drug release catheter is introduced and positioned at the site chosen by a surgeon. The proximal occlusion balloon (60) is then inflated to seal the passage of blood. The saline solution is injected through the openings disposed on the surface of the catheter between

the proximal occlusion balloon (60) and the distal occlusion balloon (70) to remove blood from the arterial segment to be treated; next, the pure fluid medication is infused to fill the space between the proximal (60) and the distal occlusion balloon (70) avoiding its dilution with the previously infused saline solution. Later on, in a short period of time, in order to avoid the prolonged and excessive infusion of fluid medication, the distal occlusion balloon (70) is inflated, forming a chamber (50) between the two occlusion balloons (60 and 70) filled with pure fluid medication. The infusion of fluid medication through the openings disposed on the catheter surface between the proximal (60) and the distal occlusion balloon (70) must be continued for a period of time in order to make the medication penetrate inside the arterial wall (100) by a difference in the concentration and pressure.