METHOD AND DEVICE FOR MICRODIALYSIS SAMPLING

• US 20100152555A1
• Filed: 12/08/2009
• Published: 06/17/2010
• Est. Priority Date: 12/09/2008
• Status: Active Grant

• Current Assignee: MD Biomedical AB (Senzime AB (publ))
• Original Assignee: Pernilla Abrahamsson
• Inventors: Abrahamsson, Pernilla Birgitta
• Granted Patent: US 8,602,990 B2
• Time in Patent Office: Days
• US Class Current: 600/309
• CPC Class Codes: A61B 10/0045 Devices for taking samples of body liquids devices for taking blood samples A61B5/15
• CPC Class Codes: A61B 2010/008 Interstitial fluid
• CPC Class Codes: A61B 5/14525 using microdialysis
• CPC Class Codes: A61B 5/14528 invasively
• CPC Class Codes: A61M 2025/0286 anchored in the skin by suture or other skin penetrating devices
• CPC Class Codes: A61M 25/00 Catheters; Hollow probes dilators A61M29/00; peritoneal catheters A61M1/285; tracheal tubes A61M16/04; for drainage A61M27/00; for uterus, vagina or rectum A61M31/00 ; for measuring or testing A61B; materials for catheters A61L29/00
• CPC Class Codes: A61M 25/02 Holding devices, e.g. on the body

Abstract

The microdialysis technique and device of the present invention can be used to study metabolic aspects of human and animal organs. When a microdialysis catheter is for example placed into the substance of a beating heart, there is always concern for problems with the catheter position. Further, there is always a risk for damage to heart tissue as well as to the catheter. The present invention is designed to avoid such damages, and a study has confirmed that data obtained from the epicardial probe of the present invention reflects the state of the myocardial metabolism. In anesthetized normoventilated pigs (n=20), a sternotomy was performed and a Gore-tex suture snare was placed around a branch of the left anterior descending (LAD) artery. One microdialysis probe was inserted in the myocardial tissue supplied by the snared LAD branch. Another microdialysis probe was placed on the epicardial surface above the myocardial probe. The protocol included four, ten minute ischemic periods (intervention group) followed by a forty minute ischemic period. The control group was only exposed to a forty minute ischemic period. It was possible to place the microdialysis probes of the present invention on the epicardial surface, and to recover samples reflecting the myocardial metabolic state of the heart. It was also possible to measure rapid changes in concentrations especially for lactate, where ischemia periods as short as ten minutes resulted in detectable increases. A similar pattern was found when analysing glucose and glycerol concentrations in paired samples. Data obtained from the device and method of the present invention, placed on the epicardial surface showed a similar pattern compared to data from a standard probe placed in the myocardium. Thus, the epicedial application of the present invention is useful for perioperative monitoring during cardiac surgery.

Claims

1. Microdialysis sampling method utilizing at least one microdialysis catheter or probe (1) placed on the surface of a vital human or animal organ for sampling metabolic substances that indicate the metabolic conditions of the organ from the surface of the organ characterized by that the catheter or probe (1), temporarily attached to the outside surface of the vital organ and not inserted into the substance of the vital organ, samples said metabolic substances via a semi-permeable membrane (9) attached to the catheter or probe (1), the side facing the surface of the organ.

2. Microdialysis sampling method according to claim 1 utilizing at least one microdialysis catheter or probe (1) placed on the surface of a vital human or animal organ for sampling metabolic substances that indicate the metabolic conditions of the organ from the surface of the organ characterized by that the catheter or probe (1) is temporarily attached to the vital organ by at least one suture.

3. Microdialysis sampling method according to claim 2 utilizing at least one microdialysis catheter or probe (1) placed on the surface of a vital human or animal organ for sampling metabolic substances that indicate the metabolic conditions of the organ from the surface of the organ characterized by that the catheter or probe (1) is temporarily attached to the vital organ by at least one suture with several millimeters of slack, preferably within an interval of 3 to 8 millimeters, in a recess in the attachment girdle 6 on the probe (1) so that the catheter (1) is not subjected to large mechanical forces relating to a beating or moving organ.

4. Microdialysis sampling catheter or probe (1) according to the method of claim 1 characterized by that the probe/catheter (1), essentially of an elliptical, rectangular or other for the purpose suitable shape, is comprised of an outer casing (2) with an inlet (3) and an outlet (4) connected by a U-shaped channel (5) that allows perfusion fluid (perfusate) or similar to flow through the probe (1).

5. Microdialysis sampling catheter or probe (1) according to the method of claim 1 characterized by that an attachment girdle (6), designed to facilitate the temporary attachment of the probe (1) to the surface tissue of a vital organ via at least one eyelet (7) using at least one suture, is integrated onto the outer casing (2) of the probe (1).

6. Microdialysis sampling catheter or probe (1) according to the method of claim 1 characterized by that on the end or tip of the probe (1) opposite the inlet (3) and outlet (4) is placed a ring (8) designed for temporarily securing the probe to a vital organ via at least one suture.

7. Microdialysis sampling catheter or probe (1) according to the method of claim 1 characterized by that a membrane (9) consists preferably of a polymer composition such as for example PAES (polyarylethersulfone).

8. Microdialysis sampling catheter or probe according to the method of claim 1 characterized by that the outer casing (2) consists preferably of a polymer material as for example polyurethane, polyamide or polyimide.

9. Microdialysis sampling method according to claim 1 utilizing at least one microdialysis catheter or probe (1) placed on the surface of a vital human or animal organ for sampling metabolic substances that indicate the metabolic conditions of the organ from the surface of the organ characterized by that at least one of the metabolic substances sampled is glucose.

10. Microdialysis sampling method according to claim 1 utilizing at least one microdialysis catheter or probe (1) placed on the surface of a vital human or animal organ for sampling metabolic substances that indicate the metabolic conditions of the organ from the surface of the organ characterized by that at least one of the metabolic substances sampled is lactate.

11. Microdialysis sampling method according to claim 1 utilizing at least one microdialysis catheter or probe (1) placed on the surface of a vital human or animal organ for sampling metabolic substances that indicate the metabolic conditions of the organ from the surface of the organ characterized by that at least one of the metabolic substances sampled is pyruvate.

12. Microdialysis sampling method according to claim 1 utilizing at least one microdialysis catheter or probe (1) placed on the surface of a vital human or animal organ for sampling metabolic substances that indicate the metabolic conditions of the organ from the surface of the organ characterized by that at least one of the metabolic substances sampled is glycerol.