EP0786957A1 - Blood vessel graft quality evaluation - Google Patents

Blood vessel graft quality evaluation

Info

Publication number
EP0786957A1
EP0786957A1 EP95935946A EP95935946A EP0786957A1 EP 0786957 A1 EP0786957 A1 EP 0786957A1 EP 95935946 A EP95935946 A EP 95935946A EP 95935946 A EP95935946 A EP 95935946A EP 0786957 A1 EP0786957 A1 EP 0786957A1
Authority
EP
European Patent Office
Prior art keywords
graft
pressure
syringe
blood vessel
blood
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP95935946A
Other languages
German (de)
French (fr)
Inventor
Dan Rottenberg
Dudu Haimovich
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Medicard Ltd
Original Assignee
Medicard Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Medicard Ltd filed Critical Medicard Ltd
Publication of EP0786957A1 publication Critical patent/EP0786957A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/026—Measuring blood flow

Definitions

  • the invention relates to the evaluation of Coronary Artery Bypass Graft (CABG) surgery and other medical procedures, which involve blood vessel surgery.
  • CABG Coronary Artery Bypass Graft
  • the invention enables to evaluate grafts and anastomotic site occlusions, leakage and proper location.
  • CABG coronary artery bypass grafts
  • the invention relates to the determination of flow rates through blood vessels involved in surgery Means and methods for effecting such measurements are provided which are exceedingly simple, yet highly efficient and which provide real time data for the surgeon performing surgery
  • Coronary bypass surgery of the type referred to in the present invention generally involves the attachment (anastomosis) of a graft blood vessel to an existing blood vessel of the patient, which is of the order of diameter of a few millimeters, carrying out the control and evaluation according to the invention, and after ascertaining that such attachment is in order, attaching the second end of the graft to the aorta
  • the device of the invention and the method of evaluation is also applicable to other types of blood vessel surgery, such as that of blood vessels of the feet etc.
  • the device comprises a liquid container provided at one end with means for applying a predetermined pressure, and at another end with exit means, means for applying controlled pressure (continuous or in pulsed form) to a liquid (saline, blood) in said container, where the pressure is applied to the free end (proximal end) of the blood vessel used as graft, after the anastomosis to the coronary artery is made to the other end (distal end) of the graft, means being provided for the accurate measurement of the parameters involved such as pressure curve, pressure inside the vessel, liquid volume, time and flow rate calculation.
  • a syringe or syringe-like container is used, to the piston of which there is applied the desired pressure, which can be essentially constant or which can be pulsed, with a pulse rate and form similar to that provided by the human heart.
  • a closed servo loop which monitors and adjusts the pressure applied to the liquid in said container (syringe).
  • the flow rate measurement through the blood vessel intended to be used for the graft is made before connecting the proximal end of the graft to the aorta; it is not required to reactivate the heart to produce pressure and establish the flow through the vessel.
  • the surgeon is able to determine in real time the graft patency whether the attachment to the artery does not leak or get blocked, and if this is not entirely satisfactory, to repair it or replace it by another graft This determination is made right after the anastomosis to the coronary artery
  • a device of the invention which comprises a syringe 11 , having a piston area of about 10 cm2 which is held in holding means 12, which grasp the flange 13 of syringe 11
  • the syringe piston 14 is attached to a movable pushing plate 15
  • a linear motor 16 that moves the pushing plate 15, which is used for pushing piston 14 into the body of the syringe 1 1
  • a 3- way stopcock 18 to which there are attached tubes 20 and 21 , tube 20 being connected with pressure transducer 19, the other tube, 21 being attached to the blood vessel to be used as graft 22
  • a 60 ml syringe was connected as part of a device shown in Fig 1 and filled with saline solution
  • a pulsative pressure of 100 mm Hg (mean value) was applied for 10 seconds
  • saline as test liquid, and after measuring the flow rate through a blood vessel intended as graft, the surgeon can decide in real time whether the graft can serve as by-pass

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Physics & Mathematics (AREA)
  • Cardiology (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Hematology (AREA)
  • Physiology (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
  • Surgical Instruments (AREA)

Abstract

A method for measuring the flow rate of a liquid, saline or blood, through a blood vessel to be used as graft on a patient in need thereof, where a certain quantity of this fluid is passed under controlled conditions through this vessel, thus establishing whether it is suitable for use as a graft. There is also provided a system for effecting such measurement which essentially comprises a large syringe connected to a pump, which passes the fluid through the blood vessel intended for use as graft, under exactly defined conditions, and means for calculating the flow rate and whether the vessel is suitable for the intended patient.

Description

DESCRIPTION
BLOOD VESSEL GRAFT QUALITY EVALUATION
FIELD OF THE INVENTION
The invention relates to the evaluation of Coronary Artery Bypass Graft (CABG) surgery and other medical procedures, which involve blood vessel surgery.
There are provided a process for the evaluation of graft patency and means for carrying out such process. The invention enables to evaluate grafts and anastomotic site occlusions, leakage and proper location.
BACKGROUND OF THE INVENTION
While myocardial revascularization has been employed for many years, the graft patency depends to a large extent on the location and quality of the anastomosis. The determination of possible blood flow through such a vessel is of cardinal importance, and exact determination of this parameter is critical for various types of surgery, and especially of coronary artery bypass grafts (CABG) surgery.
There are several methods known today to measure the blood flow rate through grafts including electromagnetic flow-meters, ultrasonic flow-meters, thermal imaging etc. The prior art does not provide direct flow measuring systems, and most of the evaluations can be carried out only towards the end of the operation, after the proximal side of the graft is connected to the aorta, and blood start flow through the graft as the result of blood pressure produced by the heart
SUMMARY OF THE INVENTION
The invention relates to the determination of flow rates through blood vessels involved in surgery Means and methods for effecting such measurements are provided which are exceedingly simple, yet highly efficient and which provide real time data for the surgeon performing surgery
Coronary bypass surgery of the type referred to in the present invention generally involves the attachment (anastomosis) of a graft blood vessel to an existing blood vessel of the patient, which is of the order of diameter of a few millimeters, carrying out the control and evaluation according to the invention, and after ascertaining that such attachment is in order, attaching the second end of the graft to the aorta
The device of the invention and the method of evaluation is also applicable to other types of blood vessel surgery, such as that of blood vessels of the feet etc There is provided a device for measuring the flow rate of a liquid through the graft to be used in surgery while it is already connected with a blood vessel of the patient, which fluid can be saline, a buffered solution or blood. The device comprises a liquid container provided at one end with means for applying a predetermined pressure, and at another end with exit means, means for applying controlled pressure (continuous or in pulsed form) to a liquid (saline, blood) in said container, where the pressure is applied to the free end (proximal end) of the blood vessel used as graft, after the anastomosis to the coronary artery is made to the other end (distal end) of the graft, means being provided for the accurate measurement of the parameters involved such as pressure curve, pressure inside the vessel, liquid volume, time and flow rate calculation.
Preferably a syringe or syringe-like container is used, to the piston of which there is applied the desired pressure, which can be essentially constant or which can be pulsed, with a pulse rate and form similar to that provided by the human heart.
There is provided a closed servo loop which monitors and adjusts the pressure applied to the liquid in said container (syringe). According to the invention the flow rate measurement through the blood vessel intended to be used for the graft is made before connecting the proximal end of the graft to the aorta; it is not required to reactivate the heart to produce pressure and establish the flow through the vessel. Thus, the surgeon is able to determine in real time the graft patency whether the attachment to the artery does not leak or get blocked, and if this is not entirely satisfactory, to repair it or replace it by another graft This determination is made right after the anastomosis to the coronary artery
DETAILED DESCRIPTION OF THE INVENTION
The invention is described with reference to the schematical drawing, in partial section, and not according to scale, of a device for use in measurements according to the invention
In this Figure there is illustrated a device of the invention, which comprises a syringe 11 , having a piston area of about 10 cm2 which is held in holding means 12, which grasp the flange 13 of syringe 11 The syringe piston 14 is attached to a movable pushing plate 15 There is provided a linear motor 16, that moves the pushing plate 15, which is used for pushing piston 14 into the body of the syringe 1 1 To the tip 17 of the syringe 11 there is attached a 3- way stopcock 18, to which there are attached tubes 20 and 21 , tube 20 being connected with pressure transducer 19, the other tube, 21 being attached to the blood vessel to be used as graft 22 There can be applied a constant pressure on the syringe piston, thus ejecting liquid from said syringe, through the vessels to be used as graft to the patient arteries, the pressure and displacement of the syringe piston are measured automatically, for a predetermined time interval, thus indicating flow rate versus applied pressure and testing the graft patency Instead, there can be applied to the piston of the syringe a pulsatile pressure This can be of values which correspond to natural pressure applied to blood in blood vessels in the human body For example, a pulsed pressure can be applied to the piston which mimics a systolic pressure of 100 mm Hg and diastolic pressure of 70 mm Hg, at a frequency of 90 per minute
Example
A 60 ml syringe was connected as part of a device shown in Fig 1 and filled with saline solution A pulsative pressure of 100 mm Hg (mean value) was applied for 10 seconds
During this 10 second period the displacement of the piston of the syringe was measured and at the end of this period of time the flow rate through the graft was calculated based on the cross-section of the syringe and the displacement of the piston during this time interval The average expected flow rate through a vein graft is about 75 ml per minute
Generally it is convenient to use saline as test liquid, and after measuring the flow rate through a blood vessel intended as graft, the surgeon can decide in real time whether the graft can serve as by-pass

Claims

1 A device for establishing in real time the graft patency and anastomosis quality of blood vessels such as aortocoronary bypass and other blood vessels, using direct flow-rate measurement, which device comprises in combination a syringe the piston of which is actuated by controllable actuation means imparting to the piston a steady pressure or a pulsed one, a tube connected at the outlet of the syringe, which tube is connected during measurement to the one side of the graft of the patient after anastomosis is made in the other side, and a three-way valve whereby another tube is attached to pressure measurement means which by a feedback control the actuation means, thus measuring the flow rate of the liquid from the syringe through the grafted blood vessel, resulting from the pressure applied on its
2 A device according to claim 1 , comprising a pressure closed loop control, to maintain the predetermined pressure wave, during an injection time interval
3 A device according to claim 1 , where actuation means are used mimicking the pulsatile blood pressure of a patient
4 A method of measuring the rate of flow of a physiologically acceptable liquid through a (vein) graft blood vessel attached by one of its ends to the blood vessel (coronary artery) of a patient, which comprises applying to the piston of a syringe holding such liquid a predetermined pressure using a pressure closed loop control, said syringe being attached to the other end of the graft, and thus measuring the rate of flow through said blood vessel graft as a function of the applied pressure and establishing whether the anastomosis is satisfactory
EP95935946A 1994-10-23 1995-10-18 Blood vessel graft quality evaluation Withdrawn EP0786957A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
IL11136694 1994-10-23
IL11136694A IL111366A0 (en) 1994-10-23 1994-10-23 Blood vessel graft quality evaluation
PCT/EP1995/004095 WO1996012438A1 (en) 1994-10-23 1995-10-18 Blood vessel graft quality evaluation

Publications (1)

Publication Number Publication Date
EP0786957A1 true EP0786957A1 (en) 1997-08-06

Family

ID=11066678

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95935946A Withdrawn EP0786957A1 (en) 1994-10-23 1995-10-18 Blood vessel graft quality evaluation

Country Status (5)

Country Link
EP (1) EP0786957A1 (en)
AU (1) AU3805995A (en)
CA (1) CA2205229A1 (en)
IL (1) IL111366A0 (en)
WO (1) WO1996012438A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE0501889L (en) * 2005-08-25 2007-02-26 Millicore Ab Kärlresistansmätare

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4273122A (en) * 1976-11-12 1981-06-16 Whitney Douglass G Self contained powered injection system
US4551133A (en) * 1984-04-16 1985-11-05 American Hospital Supply Corporation Patient controlled medication infusion system
DE69114314T2 (en) * 1990-01-08 1996-04-18 Ernest M D Feiler Diagnostic procedure for measuring blood flow.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9612438A1 *

Also Published As

Publication number Publication date
IL111366A0 (en) 1994-12-29
CA2205229A1 (en) 1996-05-02
WO1996012438A1 (en) 1996-05-02
AU3805995A (en) 1996-05-15

Similar Documents

Publication Publication Date Title
US5670708A (en) High frequency intravascular prosthesis fatigue tester
US5014715A (en) Device for measuring the impedance to flow of a natural or prosthetic vessel in a living body
EP0402964B1 (en) Apparatus for analyzing the degree of tissue dammage in a heart subjected to inadequate arterial blood flow.
Baumgartner et al. Discrepancies between Doppler and catheter gradients in aortic prosthetic valves in vitro. A manifestation of localized gradients and pressure recovery.
Pepine et al. Aortic input impedance during nitroprusside infusion: a reconsideration of afterload reduction and beneficial action
EP2673019B1 (en) Apparatus and method for real time measurement of a constituent of blood to monitor blood volume
AU633406B2 (en) Contrast media injector
US4887608A (en) Method and apparatus for estimating tissue damage
JPH10506471A (en) In-situ calibration system for sensors in physiological lines
JPS5977861A (en) Apparatus and method for measuring blood stream due to artificial heart
WO1995006433A1 (en) System calculating compliance and cardiac hemodynamic parameters
US5687718A (en) Device for continuously detecting blood parameters
US4585010A (en) Process and apparatus for measurement of outflow resistance
Baldwin et al. Simultaneous measurement of capillary distensibility and hydraulic conductance
KR20080010530A (en) Blood pressure actuating apparatus and method driven by fluid and thereby test method of a sphygmomanometer
US5800374A (en) Reperfusion device
Blair et al. Hemodynamics after microsurgical anastomosis: the effects of topical lidocaine
Vandenberghe et al. Hydrodynamic characterisation of ventricular assist devices
EP0786957A1 (en) Blood vessel graft quality evaluation
JPH01207035A (en) Blood flow model for examination of hemomanometer
Beard et al. A Doppler flowmeter for use in theatre
Bude et al. Stenosis of the main artery supplying an organ: effect of end‐organ vascular compliance on the poststenotic peak systolic velocity.
Sipkema et al. Isolated aorta setup for hemodynamic studies
JP2555283B2 (en) Device and method for intermittent occlusion of coronary sinus
Rothe et al. Renal arterial compliance and conductance measurement using on-line self-adaptive analog computation of model parameters

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19970423

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE ES FR GB IT NL SE

17Q First examination report despatched

Effective date: 19980907

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19990119