ES2368404B1 - PERCUTANEOUS CATHETER AND METHOD FOR MEASURING PRESSURE IN BLOOD VESSELS. - Google Patents

Abstract

Percutaneous catheter and method for measuring pressure in blood vessels, which allows a continuous measurement of the pressure gradient in the hepatic vein, comprising a pressure catheter (1), configured to measure and record pressure in a blood vessel (2), which comprises an inflatable element (3) configured to occlude said blood vessel (2) when it is inflated and allow free flow of blood through said blood vessel (2) when deflated, in which said pressure catheter (1) is operatively connected to a long-term intravenous catheter (4) comprising a double cavity.

Description

Portal in cirrhosis.

Percutaneous catheter and method to measure pressure in blood vessels. Object of the invention

A first aspect of the present invention refers to a percutaneous catheter and a second aspect refers to a method for measuring pressure in blood vessels, which have application in the field of medicine, and more specifically in the diagnosis of chronic liver diseases, allowing prolonged use access to the hepatic vein as well as continuous and long-term measurement of the hepatoportal venous pressure gradient, without the need to repeat invasive procedures in the patient. Background of the invention

There are a number of characteristics that give great importance to the measurement of portal vein pressure, derived from the significant complications that arise in cases of portal hypertension, in English Portal Hypertension (PHT), in which there is an increase abnormal blood pressure in said portal vein. It is noteworthy that contrary to other blood vessels, the portal vein is difficult to access for diagnostic procedures, so all of them are invasive and need to be performed in the hospital.

Portal hypertension is a very frequent complication in chronic liver diseases such as cirrhosis, being the main cause of mortality and liver transplantation in these patients.

In such cases, a sustained increase in pressure in the portal vein, results in the appearance of esophageal and gastric varicose veins, which increase the risk of bleeding events. Usually, such bleeding episodes occur in up to 35% of patients who have cirrhosis and esophagogastric varices. Likewise, portal hypertension determines the appearance of ascites, circulatory and renal function disorders, and facilitates the occurrence of serious complications such as spontaneous bacterial peritonitis and hepatic encephalopathy, among others.

Portal hypertension develops when there is an increase in resistance to the flow of blood through the liver and an increase in the inflow into the portal vein.

Currently, the measurement of pressure in the occluded hepatic vein, in English Wedged Hepatic Venous Pressure (WHVP), is the most common diagnostic procedure for the indirect determination of portal pressure. To do this, one of the hepatic veins is catheterized percutaneously under fl uoroscopic control by the transjugular route (or after the puncture of another peripheral vein, such as the femoral or antecubital) through the use of a catheter comprising an occlusion balloon, such as the described in "Berenstein occlusion balloon catheter M001173010, 17-301, Boston Scienti fi c". The balloon is then inflated until a branch of the hepatic vein is completely occluded, at which time the pressure value in the occluded hepatic vein (WHVP) is measured and recorded. Then, the balloon is deflated and the pressure in the free hepatic vein is recorded, in English Free Hepatic Venous Pressure (FHVP). The difference between both pressures is the so-called hepatic venous pressure gradient, in English Hepatic Venous Pressure

In the absence of portal hypertension, the pressure gradient in the hepatic vein, this is the gradient between occluded and free pressure, is small (less than 5 mmHg), while in the presence of portal hypertension, said gradient is increased. When it reaches values greater than 10 mmHg, it indicates the risk of complications of portal hypertension (Clinically mean portal hypertension), and when these are present, it allows discriminating patients who are at low risk of bleeding episodes, and therefore with less mortality risk, as well as guiding the treatment of portal hypertension.

However, the main drawback presented by the procedure described above is that the determination of the hepatic vein pressure gradient (HVPG) is a diagnostic procedure that frequently has to be performed several times in the same patient, and therefore every time that its execution is required, a very specialized infrastructure is needed, in addition to the cost and inconvenience that the patient has to suffer from having periodic invasive procedures for the measurement of HVPG. Description of the invention

A first aspect of the present invention refers to a percutaneous catheter for measuring pressure in blood vessels, which allows prolonged use access to the hepatic vein for a simple and repeated measurement of the pressure gradient in the hepatic vein (HVPG), overcoming the need to repeat invasive diagnostic procedures in the patient.

The catheter that the invention proposes allows its use by the transjugular route or by the subclavian route, to measure pressure in any blood vessel, that is to say in any vein and artery, such as the hepatic vein.

Well, according to the invention, the catheter comprises a pressure catheter, configured to measure and record pressure in a blood vessel, and in addition, said catheter comprises an inflexible element, like a balloon or balloon, near its distal end. It is configured to occlude said blood vessel when it is inflated and inserted into the blood vessel, as well as to allow free flow of blood through said blood vessel when it is deflated. Positioned in the hepatic vein, it is possible to measure the occluded pressure when it is swollen, and the free pressure being deflated, and therefore the hepatic venous pressure gradient (HVPG).

Additionally, said pressure catheter is operatively connected to a long-term device called Port-a-cath, comprising a double cavity.

The Port-a-cath system comprises a catheter connected to a venous access system called in English Totally Implantable Venous Access System. This system consists of a small medical device that is installed under the skin to connect to a vein. The device has membranes, which are commonly referred to as septum, through which the medication is injected or blood samples are taken, as many times as necessary and with much less discomfort for a patient, compared to the means so far used, consistent repeated catheterization of the jugular vein or

3 EN 2368404A1 4

femoral. Port-a-cath catheters are mainly used in hematological treatments and in oncology patients.

A Port-a-cath comprises a reservoir or reservoir compartment, also called "port", which is encapsulated in silicone to allow the insertion of a needle, just into the septum. Preferably the septum is made of a special self-sealing silicone allowing it to be punctured by a needle up to thousands of times before having to be replaced.

A small surgical intervention is required for placement in a patient. In it the Port-a-cath is placed under the skin, and the catheter connected to it is inserted through the jugular or subclavian vein until it reaches the hepatic vein.

The invention thus allows access to the hepatic vein and to measure the gradient of venous hepatoportal pressure, that is to say to measure the difference in pressure in the occluded and free hepatic vein, in the long term and continuously.

The catheter of the invention integrates a double light (lumen), one to measure the pressure inside the vein in which it is placed, the other to allow a balloon to swell at its end (occlusion balloon) to measure the pressure in the free and occluded hepatic vein.

It is contemplated that the catheter is configured to access the hepatic vein and measure, as well as record, pressure in the hepatic vein and detect portal hypertension by the difference between a pressure value in the occluded hepatic vein and a pressure value in the free hepatic vein.

It is contemplated that the percutaneous catheter for measuring blood vessel pressure comprises means for continuous monitoring of the pressure measured in said blood vessel.

A second aspect of the present invention relates to a diagnostic method for measuring pressure in blood vessels, which comprises using a percutaneous catheter as previously defined, without the need to perform repetitive invasive procedures on the patient.

For the purpose of the invention, the catheter can be inserted transjugularly.

The method is set to determine clinical cases of portal hypertension by continuous and / or repeated measurement of the pressure in the hepatic vein and the HVPG, comprising the following stages:

-

implant an intravenous catheter into the hepatic vein, and a subcutaneous system for prolonged use of the venous route,

-

connecting said intravenous catheter to a pressure catheter,

-

occlude the hepatic vein by means of an inflexible element and measure, as well as record, pressure, and

-

deflate the inflexible element and measure pressure.

It is also contemplated that the catheter comprises means for continuous monitoring of the pressure measured in the hepatic vein, comprising continuously monitoring said pressure, without the need to perform successive invasive procedures.

Description of the drawings

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical implementation thereof, a set of drawings is attached as an integral part of said description. In an illustrative and non-limiting manner, the following has been represented:

Figure 1.- Shows a schematic view of the percutaneous catheter that the invention proposes located in a hepatic vein.

Figure 2.- Shows a detail of the inflexible element comprising the pressure catheter, having been represented in the injected position.

Figure 3.- Shows a schematic perspective view of the catheter of the invention in which a cross-section has been made, for a better appreciation of the inner double cavity. Preferred Embodiment of the Invention

In view of the aforementioned figures, it can be observed that in one of the possible embodiments of the invention, the percutaneous catheter for measuring blood vessel pressure that the invention proposes comprises a pressure catheter (1), configured to measure and record pressure in a vessel blood (2), wherein said pressure catheter (1) comprises an inflexible element (3) that is configured to occlude said blood vessel (2) when it is inflated and inserted into the blood vessel (2), as well as to allow flow free of blood by said blood vessel (2) when it is deflated.

Additionally, the pressure catheter (1) is operatively connected to an extended-use intravenous catheter (4) comprising a double cavity.

The invention allows access to the hepatic vein and to measure the hepatoportal venous pressure gradient, that is, to measure the pressure difference in the occluded and free hepatic vein, in the long term and continuously.

The catheter of the invention integrates a dual Port-a-cath lumen with a pressure catheter (1), this is a Berenstein type catheter with occlusion balloon to measure the pressure in the free and occluded hepatic vein.

According to a preferred embodiment of the invention, the percutaneous catheter comprises means for continuous or repeated monitoring of the pressure measured in said blood vessel.

Also, the catheter is configured to access the hepatic vein and measure, as well as record, pressure in the hepatic vein and detect portal hypertension by the difference between a pressure value in the occluded hepatic vein and a pressure value in the hepatic vein free.

In view of this description and set of figures, the person skilled in the art will be able to understand that the embodiments of the invention that have been described can be combined in multiple ways within the scope of the invention. The invention has been described according to some preferred embodiments thereof, but it will be apparent to the person skilled in the art that multiple variations can be introduced in said preferred embodiments without exceeding the object of the claimed invention.

5 EN 2368404A1 6

Claims (4)

1. Percutaneous catheter for measuring pressure in blood vessels, comprising a pressure catheter (1), configured to measure and record pressure in a blood vessel (2), comprising an inflexible element

(3)

configured to occlude said blood vessel (2) when it is inflated and allow free blood flow through said blood vessel (2) when deflated, characterized in that said pressure catheter (1) is operatively connected to an intravenous catheter

(4)

of prolonged use comprising a cavity or double reservoir that is accessed by puncture, of the

that one is connected to the catheter light that allows the occlusion balloon to swell and deflate and the other to the light that allows to measure the pressure or obtain blood samples.

2.

Percutaneous catheter for measuring blood vessel pressure according to claim 1, characterized in that it comprises means for continuous monitoring of the pressure measured in said blood vessel (2).

3.

Percutaneous catheter for measuring blood vessel pressure according to any of claims 1 and 2, characterized in that it can measure the difference between a pressure value in the occluded hepatic vein and a pressure value in the free hepatic vein.

 ES 2 368 404 A1    ES 2 368 404 A1   SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 200803416 SPAIN Date of submission of the application: 01.12.2008 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: See Additional Sheet RELEVANT DOCUMENTS

Category

Documents cited Claims Affected

Y

US 4878898 A (NOVA MEDICAL SPECIALTIES) 07.11.1989, column 3, lines 5-19; column 4, line 26 - column 6, line 23; column 7, lines 49-65; figures. 1-3

Y

US 5084015 A (TERUMO KK) 28.01.1992, column 1, line 65 - column 3, line 2; column 3, line 22 - column 10, line 44; Figures 1-7. 1-3

TO

US 4601706 A (AILLON) 22.07.1986, column 2, line 65 - column 4, line 25; Figures 1-3. 1-3

TO

US 4692146 A (CORMED INC.) 08.09.1987, column 2, line 65 - column 4, line 11; figures. 1-3

TO

US 4917667 A (RETROPERFUSION SYSTEMS INC.) 17.04.1990, column 6, lines 20-44; figures. 1-3

TO

ES 2075022 T3 (DELCATH SYSTEMS INC.) 01.10.1995, column 16, line 51 - column 17, line 15. 1-3

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 25.10.2011

Examiner J. Square Prados Page 1/5

REPORT OF THE STATE OF THE TECHNIQUE CLASSIFICATION OBJECT OF THE APPLICATION A61B5 / 0215 (2006.01) A61M25 / 10 (2006.01) A61M39 / 04 (2006.01) Minimum documentation sought (classification system followed by classification symbols) A61B, A61M Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENES, EPODOC, WPI, PAJ, ECLA.  WRITTEN OPINION Date of Completion of Written Opinion: 10.25.2011 Declaration

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 1-3 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-3 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published.  WRITTEN OPINION 1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

US 4878898 A (NOVA MEDICAL SPECIALTIES) 07.11.1989

D02

US 5084015 A (KK TERUMO) 28.01.1992

D03

US 4601706 A (AILLON) 22.07.1986

D04

US 4692146 A (CORMED INC.) 08.09.1987

D05

US 4917667 A (RETROPERFUSION SYSTEMS INC.) 04/17/1990

D06

ES 2075022 T3 (DELCATH SYSTEMS INC.) 01.10.1995

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement The present application relates to a percutaneous catheter for measuring blood vessel pressure. The object of the main claim is considered not to imply inventive activity as it results from the state of the art in an obvious way for a person skilled in the art. Document D01 is considered the state of the art closest to the object of the first claim, and describes (see column 4, line 26-column 6, line 23, column 7, lines 49-65 and figures) a (references between parentheses apply to that document):

-

Percutaneous catheter for measuring pressure in blood vessels (column 1, lines 10-13), which comprises a pressure catheter (figure 1), configured to measure and record pressure in a blood vessel (column 4, lines 30-34, for example ), comprising an inflatable element (balloon 6, figures 1, 6) configured to occlude said blood vessel when it is inflated and allow free flow of blood through said blood vessel when deflated (column 5, line 65-column 6, line 3, column 7, lines 57-59, for example).

Thus, the first claim or main claim of the application differs with respect to this device known from document D01 in that:

-

said pressure catheter is operatively connected to a long-term intravenous catheter comprising a double cavity or reservoir which is accessed by puncture, of which one is connected to the catheter light that allows the occlusion balloon to swell and deflate and the other in the light that allows to measure the pressure or obtain blood samples.

The technical effect produced by this additional technical characteristic is to avoid the need to repeat invasive procedures in the patient and to obtain prolonged use access to the blood vessel for a simple, long-term and continuous measurement of pressure (see page 2, lines 14-18 of the application). It can be concluded, therefore, that the objective technical problem solved by the request (see page 4, lines 18-28, where the problem is indicated), with respect to the closest state of the art, would be how to avoid the need to repeat Invasive procedures in the patient with the inconveniences associated with them (specialized infrastructure, patient discomfort, risk of infections, etc ...). However, document D02 (see column 2, lines 27-49 and figures) describes a "long-term intravenous catheter (1, column 3, lines 35-37) comprising a double cavity or reservoir (4, 5) a the one that is accessed by puncture (column 3, lines 62-68), of which one (4) is connected to the light (22) of the catheter that allows to swell and deflate the occlusion balloon (28) (column 6, lines 35-39, column 7, lines 67-68) and the other (5) to the other light (26) ”. Thus, document D02 presents a similar device that incorporates the differentiating characteristics and which are used for the same purpose. This document D02 solves the same objective technical problem as the request (see column 1, line 49 - column 2, line 4, column 8, line 58 - column 9, line 5) and belongs to the same technological field, so it is evident for a person skilled in the art to apply these characteristics with their corresponding effect to the device of document D01, therefore reaching the device object of the main claim. In this way the combination of documents D01 and D02 is considered obvious to destroy the inventive activity of the main claim of the application.  WRITTEN OPINION Dependent claims 2-3 add a number of optional features and considered non-essential. These claims, in combination with the main claim on which they depend, do not contain additional features of inventive activity with respect to the combination of documents D01 and D02 for the following reasons: The second claim is also considered without inventive activity since the characteristics thereof are present in D01 (continuous monitoring means / pressure sensor -transducer assembly 2). The characteristic of claim three is also considered to be lack of inventive activity as it is also anticipated in D01 (column 4, lines 31-34).