prior authorization review panel mco policy submission · cerebral blood flow (cbf) is essential...

Prior Authorization Review Panel MCO Policy Submission

A separate copy of this form must accompany each policy submitted for review. Policies submitted without this form will not be considered for review.

Plan: Aetna Better Health Submission Date:06/01/2020

Policy Number: 0703 Effective Date: Revision Date:

Policy Name: Thermal Perfusion Probe for Monitoring Regional Cerebral Blood Flow

Type of Submission – Check all that apply:

New Policy Revised Policy* Annual Review – No Revisions Statewide PDL

*All revisions to the policy must be highlighted using track changes throughout the document.

Please provide any clarifying information for the policy below:

CPB 0703 Thermal Perfusion Probe for Monitoring Regional Cerebral Blood Flow

Policy is new to Aetna Better Health of Pennsylvania. Evicore is using policy for review.

Name of Authorized Individual (Please type or print):

Benjamin Alouf, MD, MBA, FAAP

Signature of Authorized Individual:

Revised July 22, 2019 Proprietary

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Thermal Perfusion Probe for Monitoring Regional Cerebral Blood Flow - Medical Clinica... Page 1 of 10

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Thermal Perfusion Probe for Monitoring Regional Cerebral Blood Flow

Policy History

Last Review

01/27/2020

Effective: 05/03/2005

Next

Review: 07/24/2020

Review History

Definitions

Additional Information

Clinical Policy Bulletin

Notes

Number: 0703

Policy *Please see amendment for Pennsylvania Medicaid

at the end of this CPB.

Aetna considers a thermal perfusion probe for monitoring

regional cerebral blood flow experimental and investigational

because there is insufficient evidence of the clinical value of

these approaches in the management of individuals with acute

neurological disorders (e.g., head injury, subarachnoid

hemorrhage, or following neurosurgery) or for other

indications.

See

CPB 0663 - Cerebral Perfusion Studies

also (../600_699/0663.html)

.

Background

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Cerebral blood flow (CBF) is essential for normal metabolism

of the brain. Ischemic brain injury occurs when CBF is

insufficient to meet metabolic demand, which can occur in

acute neurological disorders (e.g. head injury, subarachnoid

hemorrhage, or following neurosurgery).

Various imaging techniques have been attempted to identify

individuals at risk for secondary ischemic brain injury and

manage response to therapies. Some of these techniques are

still evolving (e.g., stable-xenon-enhanced computed

tomography (XeCT), perfusion computed tomography,

perfusion magnetic resonance imaging, single photon

emission computed tomography (SPECT) and positron

emission tomography (PET)). While these techniques can

provide regional information about CBF, the data provided is a

single snap shot in time. Methods for the continuous

measurement of CBF have been investigated and are now

commercially available. One such method is a thermal

perfusion probe, which is placed intra-cerebrally via a burr hole

in the vascular area of interest in the brain. The probe is

connected to a monitor that displays CBF data.

The QFlow 500 probe (Hemedex, Inc, Cambridge, MA) is an

example of a commercially available thermal perfusion probe

that has received 510(k) marketing clearance from the Food

and Drug Administration (FDA). It is used along with the

Bowman Perfusion Monitor, Model 500 (Hemedex, Inc,

Cambridge, MA). According to the manufactures website, one

potential application of the device is for monitoring CBF in

patients with traumatic brain injury to help identify secondary

ischemic injury to the brain. The manufacturer states that, by

measuring continuous, real-time CBF, clinicians may identify

cerebral edema and measure tissue blood flow response to

therapies. Another potential neurological application is

monitoring CBF following neurosurgery (e.g., aneurysm and

subarachnoid hemorrhage procedures).

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Current literature on thermal perfusion probes has focused on

their clinical feasibility and technical capabilities. Jaeger et al

(2005) measured regional cerebral blood flow (rCBF) using the

QFlow in patients with severe subarachnoid hemorrhage (n =

5) and traumatic brain injury (n = 3) and compared these

results to brain tissue oxygen measurements (P(ti)O(2)) using

the Licox (GMS, Kiel-Mielkendorf, Germany) for an average of

9.6 days. The data indicated a significantcorrelation between

CBF and P(ti)O(2) (r = 0.36). After 400 intervals of 30-min

duration, the QFlow and the P(ti)O(2) measurements

correlated 72 % of the time when P(ti)O(2) changes were

greater than 5 mm Hg (r > 0.6). In 19 % of the intervals a

statistically significant correlation was observed (r < 0.6).

During the remaining 9 %, no correlation was found (r < 0.3).

The authors suggested that the level of P(ti)O(2) is

predominately determined by rCBF, since changes in P(ti)O(2)

were correlated in 90 % of episodes to simultaneous changes

of CBF. Phases of non-monitoring were mostly due to fever of

the patient, when the system does not allow monitoring to

avoid overheating of the cerebral tissue.

Vajkoczy et al (2003) obtained rCBF using thermal-diffusion

(TD) microprobes to prospectively diagnose symptomatic

vasospasm in 14 patients with high-grade subarachnoid

hemorrhage (SAH) who underwent early clip placement for

anterior circulation aneurysms. The TD microprobes were

implanted into the white matter of vascular territories that were

deemed at risk for developing symptomatic vasospasm. Data

on arterial blood pressure, intracranial pressure, cerebral

perfusion pressure, rCBF, cerebrovascular resistance (CVR),

and blood flow velocities were collected at the patient's

bedside. The diagnosis of symptomatic vasospasm was

based on the manifestation of a delayed ischemic neurological

deficit and/or a reduced territorial level of CBF as assessed

using stable XeCT scanning in combination with vasospasm

demonstrated by angiography. Bedside monitoring of TD-

rCBF and CVR allowed the detection of symptomatic

vasospasm. In the 10 patients with vasospasm, the TD-rCBF

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decreased from 21 +/- 4 to 9 +/- 1 ml/100 g/min), whereas in

the 4 other patients the TD-rCBF value remained unchanged

(mean TD-rCBF = 25 +/- 4 compared with 21 +/- 4 ml/100

g/min). Based on a comparison of the results of TD-rCBF and

Xe-enhanced CT studies, as well as the calculation of

sensitivities, specificities, predictive values, and likelihood

ratios, the investigators identified a TD-rCBF value of 15

ml/100 g/min as a reliable cutoff for the diagnosis of

symptomatic vasospasm. In addition, the investigators found

that TD flowmetry was characterized by a more favorable

diagnostic reliability than transcranial Doppler

ultrasonography. The authors concluded that TD flowmetry

represents a promising method for the bedside monitoring of

patients with SAH to detect symptomatic vasospasm.

Tasneem and colleague (2017) stated that neuro-critical care

patients are at risk of developing secondary brain injury from

inflammation, ischemia, and edema that follows the primary

insult. Recognizing clinical deterioration due to secondary

injury is frequently challenging in comatose patients. Multi-

modality monitoring (MMM) encompasses various tools to

monitor cerebral metabolism, perfusion, and oxygenation

aimed at detecting these changes to help modify therapies

before irreversible injury sets in. These tools include intra-

cranial pressure (ICP) monitors, transcranial Doppler (TCD),

Hemedex (thermal diffusion probe used to measure regional

CBF), micro-dialysis catheter (used to measure cerebral

metabolism), Licox (probe used to measure regional brain

tissue oxygen tension), and continuous

electroencephalography. Cerebral blood flow can be

measured by inserting a thermal diffusion probe (TDP) directly

into brain parenchyma. The commercially available system

includes the Hemedex monitoring system, which is not MRI

compatible. It allows regional CBF (rCBF) monitoring by

assessing thermal convection due to tissue blood flow. The

probe tip is inserted into white matter of brain and its utility

depends on proximity to the area of interest. Thermal diffusion

probe has been validated by Xenon perfusion CT and CBF

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level below 15 ml/100 g/min is identified as threshold for

diagnosis of hypo-perfusion. Per MMM consensus guidelines,

TDP should be placed in vascular territory of ruptured

aneurysm to monitor for vasospasm. Quantification of rCBF

with TDP is highly dependent on patient's core body

temperature and is significantly altered i n conditions of

hyperthermia. To-date, there are no published studies of

improved outcome with treatment strategies directed solely by

CBF monitoring, however it appears to be a promising tool to

use in conjunction with other parameters. Nevertheless, MMM

is now a reality commonly used in advance neuro-critical care

units throughout the world. Although various studies have

shown the physiologic feasibility of monitoring various

neurologic parameters, there is still no published data from

randomized trials to support that targeting any variable

improves clinical outcome. The authors concluded that

although further research is needed t o demonstrate the impact

of MMM on improving clinical outcomes, their contribution to

illuminate the black box of the brain in comatose patients is

indisputable.

Current literature on thermal perfusion probes has focused on

their feasibility and technical capabilities. Prospective clinical

outcome studies are needed to determine their clinical value

over other standard methods of identifying individuals at risk

for secondary ischemic brain injury (e.g., head injury,

subarachnoid hemorrhage, or following neurosurgery) and in

monitoring response to therapies.

CPT Codes / HCPCS Codes / ICD-10 Codes

Information in the [brackets] below has been added for clarification purposes. Codes requiring a 7th character are represented by "+":

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Code Code Description

Other CPT codes related to the CPB:



0042T Cerebral perfusion analysis using computed

tomography with contrast administration,

including post-processing of parametric maps

with determination of cerebral blood flow,

cerebral blood volume, and mean transit time

61000 -

64999

Nervous System/Surgery

ICD-10 codes not covered for indications listed in the CPB ( no t all-inclusive):

E75.00 -

E75.19,

E75.23

E75.25,

E75.29,

E75.4

Disorders of sphingolipid metabolism and other

lipid storage disorders

G00.0 -

G09

Inflammatory diseases of the central nervous

system

G11.0 -

G12.9

G13.8

Systemic atrophies primarily affecting the

central nervous system

G20 - G26 Extrapyramidal and movement disorders

G30.0 -

G32.8

Other degenerative diseases of the nervous

system

G35 -

G43.919

Demyelinating diseases of the cental nervous

system and episodic and paroxysmal disorders

G45.0 -

G45.9

Transient cerebral ischemic attacks and related

syndromes

G46.0 -

G46.8

Vascular syndromes of brain in cerebrovascular

diseases

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G80.0 -

G83.9

Cerebral palsy and other paralytic syndromes

G90.01 -

G91.9,

G93.7,

G93.89,

G93.9

G94,

G95.0 -

G95.9,

G99.0,

G99.2

Other disorders of the nervous system

I60.00 -

I66.9,

I67.1 -

I67.2

I67.4 -

I69.998

Cerebrovascular diseases

S02.0xx+

-

S02.413+

S02.60x+

-

S02.92x+

Fracture of skull and facial bones, with or

without intracranial injury

S06.0x0+

-

S06.9x9+

Intracranial injury, excluding those with skull

fracture

Z13.850 Encounter for screening for traumatic brain

injury

Z13.858 Encounter for screening for other nervous

system disorders

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The above policy is based on the following references:

1. De Georgia MA, Deogaonkar A. Multimodal monitoring in

the neurological intensive care unit. Neurologist. 2005;11

(1):45-54.

2. Jaeger M, Soehle M, Schuhmann MU, et al. Correlation

of continuously monitored regional cerebral blood flow

and brain tissue oxygen. Acta Neurochir (Wien).

2005;147(1):51-56.

3. Vajkoczy P, Horn P, Thome C, et al. Regional cerebral

blood flow monitoring in the diagnosis of delayed

ischemia following aneurysmal subarachnoid

hemorrhage. J Neurosurg. 2003;98(6):1227-1234.

4. Thome C, Vajkoczy P, Horn P, et al. Continuous

monitoring of regional cerebral blood flow during

temporary arterial occlusion in aneurysm surgery. J

Neurosurg. 2001;95(3):402-411.

5. Steiner LA, Czosnyka M. Should we measure cerebral

blood flow in head-injured patients? Br J Neurosurg.

2002;16(5):429-439.

6. Vajkoczy P, Roth H, Horn P, et al. Continuous monitoring

of regional cerebral blood flow: experimental and clinical

validation of a novel thermal diffusion microprobe. J

Neurosurg. 2000;93(2):265-274.

7. Bouma GJ, Muizelaar JP. Evaluation of regional cerebral

blood flow in acute head injury by stable xenon-enhanced

computerized tomography. Acta Neurochir Suppl (Wien).

1993;59:34-40.

8. Jagoda AS, Cantrill SV, Wears RL, et al. Clinical policy:

Neuroimaging and decision making in adult mild

traumatic brain injury in the acute setting. Ann Emerg

Med. 2002;40:231-249.

9. Haberl RL, Villringer A, Dirnagl U. Applicability of laser-

Doppler flowmetry for cerebral blood flow monitoring in

neurological intensive care. Acta Neurochir Suppl (Wien).

1993;59:64-68.

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10. Hemedex, Inc. Bowman Perfusion Monitor [website].

Cambridge, MA: Hemedex; 2002. Available at:

http://www.hemedex.com/bpmonitor.html. Accessed

March 9, 2005.

11. U.S. Food and Drug Administration (FDA), Center for

Devices and Radiologic Health (CDRH). QFlow 500

Perfusion Monitoring System. 510(k) Summary of Safety

and Effectiveness. 510(k) No. K013376. Rockville, MD:

FDA; May 8, 2002.

12. Barth M, Capelle H-H, Münch E, et al. Effects of the

selective endothelin A (ETA) receptor antagonist

clazosentan on cerebral perfusion and cerebral

oxygenation following severe subarachnoid hemorrhage

– preliminary results from a randomized clinical series.

Acta Neurochir (Wien) 2007;149(9):911-918.

13. Rosenthal G, Sanchez-MejiaRO, et al. Incorporating a

parenchymal thermal diffusion cerebral blood flow probe

in bedside assessment of cerebral autoregulation and

vasoreactivity in patients with severe traumatic brain

injury. J Neurosurg. 2011;114(1):62-70.

14. Tasneem N, Samaniego EA, Pieper C, et al. Brain

multimodality monitoring: A new tool in neurocritical care

of comatose patients. Crit Care Res Pract.

2017;2017:6097265.

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Thermal Perfusion Probe for Monitoring Regional Cerebral Blood Flow - Medical Clinica...Page 10 of 10

Copyright Aetna Inc. All rights reserved. Clinical Policy Bulletins are developed by Aetna to assist in administering plan

benefits and constitute neither offers of coverage nor medical advice. This Clinical Policy Bulletin contains only a partial,

general description of plan or program benefits and does not constitute a contract. Aetna does not provide health care

services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors

in private practice and are neither employees nor agents of Aetna or its affiliates. Treating providers are solely

responsible for medical advice and treatment of members. This Clinical Policy Bulletin may be updated and therefore is

subject to change.

Copyright © 2001-2020 Aetna Inc.

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AETNA BETTER HEALTH® OF PENNSYLVANIA

Amendment to Aetna Clinical Policy Bulletin Number: 0703 Thermal

Perfusion Probe for Monitoring Regional Cerebral Blood Flow

There are no amendments for Medicaid.

www.aetnabetterhealth.com/pennsylvania new 06/01/2020

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