Celsius Control System or Temperature Modulation Therapy
The Celsius Control System (or Temperature Modulation Therapy) Philips Innercool Systems, Philips Healthcare) provides physicians with a state-of-the-art, endovascular technology that can safely and rapidly lower the patient body temperature, precisely maintain a chosen target temperature and rewarm patients to normothermic levels.
Medical research suggests there are a number of potential clinical applications for the Celsius Control System such as inducing mild hypothermia in surgery, stroke and heart attack or for temperature control in surgical and critical care procedures.
The Celsius Control System consists of an endovascular catheter, console and proprietary disposables. The distal portion of the catheter incorporates a flexible Temperature Control Element (TCE) that is cooled or warmed with saline solution circulated in a closed-loop manner from the console. When placed in the inferior vena cava, the TCE exchanges thermal energy directly with the blood, resulting in cooling or warming of the downstream organs and body. The Celsius Control System does not infuse fluid into the patient, nor is blood circulated outside of the body.
Celsius Control System
The Celsius Control System consists of a disposable endovascular heat transfer catheter, administration cassette, and a console. The distal portion of the catheter (10.7 Fr. and 14 Fr.) has a flexible, metallic temperature control element (TCE) that is cooled or warmed by sterile saline circulated within it from the Celsius Control Console. The administration cassette connects the catheter to the console, maintaining the sterility of the saline conduit. The TCE does not expand inside the body so the outer diameter of the TCE will remain consistent throughout the entire cooling/warming procedure unlike balloon based cooling systems which expand to outer diameters of 24 Fr.-47 Fr. during use.
INNERCOOL Therapies’ Accutrol catheter contains an integrated temperature sensor, which can accurately determine the patient’s core body temperature within 0.1°C of pulmonary artery temperature. The proprietary, novel Accutrol software control algorithm provides automated body temperature control. The Accutrol system eliminates the need to place bladder or rectal probes, which can be slow to react to actual decreases in core body temperature, may be uncomfortable to the patient and time-consuming to place. The Accutrol catheter is beneficial in the critical care environment where gradual rewarming may be warranted.
The Standard catheter incorporates the same design features as the Accutrol catheter including performance attributes. However, an external core temperature feedback probe is required for operation
MAGNETIC RESONANCE IMAGING (MRI)
The Celsius Control Catheter is “MR Conditional” according to the American Society for Testing and Materials (ASTM) International, Designation: F2503. Standard Practice for Marking Medical Devices and Other Items for Safety in the Magnetic Resonance Environment. The Celsius Control Catheter demonstrates no known hazards when a “head-only” MRI procedure is performed according to the conditions stated in this labeling.
It is important to read and understand this document in its entirety before conducting a head-only MRI (magnetic resonance imaging) procedure on a patient with an indwelling Celsius Control Catheter. Failure to strictly adhere to these guidelines may result in serious injury to the patient. This information applies to the following INNERCOOL Therapies products:
11-10-65-1 Celsius Control Standard Catheter 10.7 Fr.
11-14-65-1 Celsius Control Standard Catheter 14 Fr.
11-10-65-2 Celsius Control Accutrol Catheter 10.7 Fr.
11-14-65-2 Celsius Control Accutrol Catheter 14 Fr
-Disconnect Celsius Control Catheter from the Celsius Control Console completely prior to entering the MRI environment. Failure to do so may result in serious injury to the patient. It is not possible to continue therapy with the system during an MRI procedure.
-This labeling information applies to “head-only” MRI procedures conducted using a 1.5- Tesla transmit/receive RF head coil or a transmit RF body/receive-only head coil, ONLY.
MRI examinations of other parts of the body is strictly prohibited with the Celsius Control Catheter in situ.
-Testing has not been performed using other MR systems operating at other static magnetic field strengths (i.e., 1.5-Tesla, only) and, therefore, other scanners should not be used to perform an MRI examination on a patient who has an indwelling Celsius Control Catheter.
-The Celsius Control Catheter must be properly positioned per the directions for use with the catheter introduced through the femoral vein of either the left or right groin of the patient and advanced into the IVC such that the catheter is parallel to the bore of the MR system. Do not perform the MRI examination with the Celsius Control Catheter placed in any other configuration. Failure to follow this guideline may result in serious injury to the patient.
-Using the transmit/receive RF head coil, do not exceed an MR system reported whole body averaged specific absorption rate (SAR) greater than 0.4-W/Kg.
-Using the transmit RF body coil/receive-only head coil, do not exceed an MR system reported whole body averaged SAR of greater than 3.5-W/Kg.
The Celsius Control Catheter has undergone extensive in vitro testing to demonstrate that, by following specific guidelines, it is safe to perform a head-only MRI procedure on a patient with this device in a 1.5-Tesla MR system, ONLY. Variability among MR systems, differences in how scanners estimate or calculate specific absorption rates (SAR) cannot be simulated comprehensively using in vitro techniques. This document outlines recommended guidelines and specific conditions under which the Celsius Control Catheter has been shown to pose minimal risk to a patient undergoing a head only MRI procedure. Deviation from these guidelines may increase the potential for serious harm to the patient. MRI conditions utilizing MR systems with higher or lower static magnetic fields have not been assessed for the Celsius Control Catheter and, as such, must be avoided to ensure patient safety. The user of this information assumes full responsibility for the consequences of conducting a MRI examination on a patient with an indwelling Celsius Control Catheter.
Magnetic Field Interactions
Translation Attraction and Torque. Magnetic materials contained within an implanted or indwelling device may experience translational or rotational forces when brought into the static magnetic field of a MRI system. The Celsius Control Catheter contains relatively minor magnetic materials. In vitro testing demonstrated that the Celsius Control Catheter is not substantially affected by translational attraction and torque related to exposure to a 1.5 Tesla MR system.
Under certain conditions, RF fields generated by MRI can induce substantial currents in metallic components contained within medical device products. This may rapidly produce significant heating of a device. Failure to follow the recommendations contained in this communication may result in the generation of thermal lesions and serious patient harm. In vitro testing demonstrated that the Celsius Control Catheter is not substantially affected by the RF fields related to exposure to a 1.5 Tesla MR system under the conditions used for testing.
The presence of the Celsius Control Catheter will cause moderate artifacts on the MR image depending on the pulse sequence parameters used for MRI. However, the artifacts are confined to the position of the Celsius Control Catheter and, as such, will not affect the diagnostic use of MR imaging for head only MRI examinations.
In addition to standard safety procedures for MRI, the following precautions must be followed specific to the Celsius Control Catheter:
1) Inform the patient of the potential risks of undergoing a MRI procedure with the Celsius Control Catheter.
2) Disconnect all cables and patient monitoring devices attached to the Celsius Control Catheter prior to transporting the patient into the MRI environment.
3) The MRI procedure must be performed using a 1.5-Tesla MR system, only.
4) MRI examinations must be performed to image the head only. Use only the following types of radio frequency (RF) coils for the MRI procedure:
a) Transmit/receive RF head coil
b) Transmit body RF coil/receive-only head coil.
5) Using the transmit/receive RF head coil, do not exceed an MR system reported SAR of 0.4-W/kg. Using the transmit RF body coil/receive-only RF head coil, do not exceed an MR system reported SAR of 3.5-W/kg.
6) It is important to place the Celsius Control Catheter in a specific geometry to minimize the potential for excessive heating during the MRI procedure. The Celsius Control Catheter must be properly positioned as per the directions for use with the catheter introduced through the femoral vein of either the left or right groin of the patient and advanced into the IVC such that the catheter is parallel to the bore of the MR system (but not touching the bore of the MR system). Do not perform the MRI examination with the Celsius Control Catheter placed in any other configuration. Failure to follow this guideline may result in serious injury to the patient.
7) Ensure that the proper patient weight is used for the SAR calculations. Verify that the MRI system has appropriately calculated and updated the SAR value after all parameter changes have been made.
8) A knowledgeable MRI expert (e.g., MRI physicist, MRI-trained radiologist, etc.) must verify that all set-up steps and settings have been properly implemented and checked prior to performing the head only MRI procedure.
9) Verify that all proposed MRI examination parameters and conditions for the Celsius Control Catheter comply with the instructions described herein. If they do not comply, do not perform the head only MRI procedure.
10) Provide the patient with a means by which he/she can alert the MR system operator during the MRI procedure if any discomfort or unusual sensations should occur.
11) Monitor the patient continuously during the head only MRI examination and be prepared respond or to terminate the MRI procedure immediately in the event of a complaint.
12) Determine if the patient has any other implants or conditions that would prohibit or contraindicate a head only MRI examination. Do not conduct a head only MRI examination if any conditions or implanted devices that would prohibit or contraindicate a MRI are present.
MR healthcare professionals are advised to contact the manufacturer to ensure that the latest safety information is obtained and carefully followed in order to ensure patient safety relative to the use of an MR procedure.