CPT Flashcards
What is FDA approval for SCS?***
Approved for treatment of chronic intractable pain of trunk and limbs
Motor Neurons***
Transmit impulses from the central nervous system to muscles & glands
Sensory Neurons***
Run from various type of stimulus receptors to the CNS and carry information such as touch, odor, taste, or vision
Nociceptive Pain***
Pain that develops in response to a specific situation and damages tissue
Neuropathic Pain***
Pain that develops when the nervous system is damaged or not working correctly due to disease
Patient complains of burning, stinging pain in low back that shoots down both extremities…. What kind of pain? Would they be a candidate for neurostimulation?
Patient has Neuropathic Pain therefore is a good candidate for Neurostimulation
Patient has intermittent, aching pain that is alleviated when patient sits down and hunches over…. good candidate? why or why not?
No not a good candidate because neurostimulation is used to treat intractable pain which is pain that is constant & not curable
5 Characteristics of Chronic Pain
- Constant / Persistant
- Last longer than 6 months
- Serves no protective function
- May spread or increase in intensity
- Has no obvious cause
3 Conditions Treated with Neurostimuation
- CRPS
- FBSS
- Phantom limb or Residual limb
Define Hyperalgesia
is increased sensitivity to painful stimuli
Define Allodynia
pain caused by stimulus that doesn’t normally caused pain.
5 Parts of Neuron***
- Dendrites
- Soma
- Axon Hillock
- Axon
- Axon Terminal
Dendrite Function***
Receives signal from other nerve cells
Soma Function***
Generates & Processes Signals
Axon Hillock Function***
Controls the firing of neuron
Axon Function***
Transmit the signal
Axon Terminal Function***
Releases transmitted signal (exit)
Action Potiental
occurs when a stimulus reaches a certain thershold
You are mapping patient with low back pain in tonic, and you are unable to get paraesthesia in low back. After multiple changes in polarity the patient say he only feels tingling in legs. List reason why this may be occuring
Low back is more lateral and less myelinated
What two structures comprise the CNS
Brain and Spinal Cord
How can CSF produce challenges to Neurostimulators?
Disperses electrically field because CSF is highly conductive
Where is dorsal CSF thickest due to the kyphotic curve?
Mid to Upper Thoracic region
3 Layers on the Meninges & Function***
- Pia Mater - inner most layer
- Arachnold Mater - middle layer that contains CSF
- Dura Mater - outer layer
In order from top to bottom, list the 5 bone groups of the Spinal Column and how many bones in each
- Cervical - 7 segments
- Thoracic - 12 segments
- Lumbar - 5 segments
- Sacrum - 4 - 5 segments
- Coccyx - 4-5 bones
5 parts of vertebral body
- Spinous process
- Pedicles
- Lamina
- Transverse Process
- Vertebral body
Oblique C- Arm
Moved right or left to align the spinous process
Cephalad
move C - Arm toward head
Caudal
move C - Arm toward trunk/tail
Why is lateral image always necessary
to ensure leads are placed in posterior space
C - Arm tilted cephald to align what
endplates
Pulse width of SCS IPG***
20-1000ms
Max recommended implant depth for proclaim IPG & why
4cm for comfort & to be able to communicate with bluetooth
Primary differences for proclaim 5 & 7
Size, longevity & warranty
Surgery Mode
reduces possibility of negative device interactions during surgical procedure
Rep responsibilities to protect IPG
- put in surgery mode
- Confirm IPG is working correctly before closing pocket
- Keep IPG far away
Upgradeability
means we are able to offer patients technology and features upon FDA approval without surgery or replacement
First Upgradeable System
Proclaim XR in 2019
Protege and Prodigy IPG warranty time & unmet medical expense amount***
7 years and $1250
How long are the EonMini, Protege, Protege MRI and Prodigy IPGs FDA approved to last
up to 10 years
How deep can prodigy be implanted & why
2.25cm to ensure able to connect to charger
Tonic Programming ranges for Eon, Protege and Prodigy Family
Freq - 20-1200 hz
Pulse width - 50-500ms
Amplitude - 0-25.5ma
Which rechargeable IPG is first to come with BurstDR enabled out of box
Prodigy MRI
What gauge of epidural needles do we use for SCS leads? what length can you order? what is the curved tip needle called
- 14 gauge
- 4 and 6 inch
- Curved is the Coude
5 Key Features of Swiftlock
- Distal strain relief
- Depth indicator (1cm)
- Eyelets
- Locking area
- Suture grooves
What are the electrodes made of on Abbotts percutaneous leads and paddle leads
Platinum - Iridium
Why are the contacts on the penta lead micro textured?***
to maintain current density despite smaller footprint (increase surface area) and to help overcome impedences
Dr Holsheimers findings on difference between the anatomical and physiological midlines
40% of patient’s spinal cords are 1-2mm off midline
How many columns & rows of penta lead?
5 Columns
4 Rows
On penta lead how many contacts and how many independent contacts?
20 total and 12 independent
Electrode array width and overall width on penta
electrode array width is 9mm and overall width is 11mm
What is RF power restriction for Proclaim XR and 60cm octrode leads
30 mins active scan, 30 min waittime
No more MRI restriction on lead for Proclaim XR means leads can be placed where for octrode & penta
Octrode- C1 - S2
Penta - T7-T12
MRI expansion was for what IPG and lead?
Proclaim XR
60Cm octrode lead
Where can IPG be place to meet MRI conditional parameteres
Upper buttock, low back, flank, abdomen or midline
Abbotts competitive advantage with MRI expansion
30 min active scan, 30 min waitime
Abbotts competitive advantage with MRI expansion
30 min active scan, 30 min wait time
Boston Scientific & Medtronic scan vs wait time
30 min scan, 60 mins wait time
How should a patient be positioned for an SCS procedure?
Prone position
Cervical - pillow under chest, arms neutral, chin to chest
Thoracic - pillow under abdomen, neutral spine, arms out of fluoroscopy
4 things to avoid during SCS trial period to prevent lead migration
- Bending
- Lifting
- Twisting
- Do not get wet
What needle angle should the physician take to access the epidural space at T12 - L1?
30 degrees or less
What would you suggest if physician hit resistance
To use guidewire when hitting obstruction in epidural space
Where would you place leads for back pain***
T7 - T8 or T8 - T9
Where would you place leads for back and leg pain***
T8 - T9
Where would you place leads for leg pain***
T9 - T10 or T10 - T11
Where would you place leads for foot pain?***
T10-T11 or T11-T12
When intraop testing which lead should be place on left side of IPG?***
Match left lead with port 1-8
7 products to take into OR
- IPG
- Leads
- Anchors
- patient remote
- Clinician controller
- Anticipated accessories
- charger as surgeon may ask to charge
Describe prep for Proclain IPG with scrub tech / physician before inserting leads
On Proclaim headers come tight so you will need to loosen in quarter turn increments with torque wrench (2 full rotations)
What do you do with excess lead prior to placing IPG in pocket?
excess leads or extensions should be coiled in large loops and placed behind battery
Laminectomy
complete removal of lamina
Laminotomy
enlarging interlaminar space or removing partially removing lamina
Hemilaminotomy
removing one side on lamina
What level should laminectomy be performed if leads are being placed at T8?
1-2 vertebral levels below so T9-T10
What direction should tunnel be created
midline to pocket
Explain tunneling process
subcutaneous tunnel is created between anchor site and IPG. Avoid tunnel through muscle. Withdrawn plastic sleeve from tunnel & avoid removing strain relief loop
Is swiftlock used on Penta Leads? why? ***
No, anchors are not used for penta leads because the indicator marks
Describe good X Ray for Penta
- Spinous process midline
- Endplates squared
- Pedicles clear
- Shiney side of penta down
For proclaim implant, should the electrosurgical device be in monopolar or bipolar mode
Always Bipolar Mode
Characteristics of BurstDr waveform
- Proprietary to abbott
- eliminates parathesis
- low programming burden
- modulates both lateral and medial pathways
- superior to tonic
How many pulses are in a burstDR pulse train
5 pulses
***Medial pathway
is your emotional response, suffering component and your attention to pain
Lateral pathway***
is your physical response, perception of pain and the sensory effect
Primary endpoint of the sunburst study
was to prove non-inferiority of burst stimulation to tonic stimulation in overall VAS scores at 24 weeks for FDA approval
How many patients ENROLLED in sunburst study
173
How many patients were randomized in sunburst study
100
what was design of Sunburst study
randomized with crossover design for 1 year
In sunburst, what percent of patients preferred Burst over Tonic SCS
70.8 %
Why do we use BoldXR dosing protocol to program patients
Dosing results in patients receiving minimal stimulation while maintain therapeutic effect and increase battery life
List the BoldXR programs given to patients
- 30 seconds on, 6 min off
- 30 seconds on, 3 mins off
- 30 seconds on, 90 seconds off
Results of Bold Clinical Study
100% of patients remained on dosed settings and 50% remained on lowest dose
Key Takeaways from the BOLDER study
- 81% remained on lowest energy setting
- 68% and 69% no longer catastrophizing at follow up
- 80% and 77% improved across multidimensional responder rate
- No difference found in pain relief, function & pain catastrophizing between groups
BOLD Guarantee
5 year warranty on battery life when patients use burst with BOLD XR dosing protocol
7 Features & Benefits of Proclaim XR SCS system
- up to 10 year battery life at low dose settings
- don’t have to recharge
- superior BurstDr therapy
- familiar apple devices
- upgradeable
- Full Body MRI conditional labeling
- back by industry leading 5 year battery life warranty
Pulse width is measured in
Microseconds
Frequency is measured in
Hertz
Amplitude is measured in
Milliamps
where does depolarization occur
at cathode
Which programming parameter has greatest impact on battery
Frequency
which programming parameter has most direct impact on which nerves are stimulated
Polarity
increasing amplitude will or will not increase area of activation
will
What technology provides ability to change electrode configurations with active amplitude
Multisteering
What position should patient be in when programing BurstDR
Supine Position
What are default settings for BurstDR
Frequency - 40 hertz
Intra Burst Rate - 500 Hertz
Pulse Width - 1000ms
What is max target amplitude for BurstDR
1.5 milliamps
When using BurstDR, amplitude should be decreased by what % of required energy for patient perception
40%
Should you ever change the pre defined burst parameters ?
no
T junction asks as
a. a barrier to AP propagation to DH
b. a low pass filter to AP propagation to DH
c. propagator of AP
Following electrical stimulation of the DRG does membrane excitability increase or decrease?
Decrease
Where is DRG located
within the epidural space inferior to the pedicle
the DRG sits in what aspect of the neural foraman
Superior
DRG is largest at which level
L5
During lead placement where does the lead pass through to access the DRG in the neural foramen
Intra Foraminal Ligaments
Design of the ACCURATE Study
a prospective, randomized, multi-center, controlled clinical trial to access the safety and efficacy of the Axium Stimulator in treatment of CPRS 1 and 2 for lower extremities
Did Accurate Stidy include chronic intractable pain of upper and lower extremities
NO just lower. T10 and below
how many patients were enrolled in the ACCURATE study
152
In Accurate Study, What percentage of the implant only group reached the primary end point at 3 months
93.3%
in Accurate Study, What percentage of the implant only group VS control reached the primary end point at 12 months
86% of implant
70% of control
In accurate study, what percentage of patients were considered high responders
70%
FDA indication for DRG
for SCS via epidural and intraspinal lead access to DRG to aid in the management of moderate to severe chronic intractable pain of the lower limbs in patients with CRPS 1 and 2
DRG levels for groin, knee and foot pain
Groin - T12 to L1
Knee - L3 to L4
Foot - L4 to S1
if patient has sympathetic symptoms would it be CRPS 1 or 2
CRPS 1
How many electrodes does axium slim tip lead have
4 electrodes
What does the black marker indicate on needle
direction of the bevel
what length does axium needles come in for DRG
4.5 and 6 inch
What are two curve sizes of axium delivery sheath
2mm and 8mm
What is the purpose of the white marks on sheath?
needle exit indicators or when sheath is at end of needle
Can a torque wrench with the SCS and DRG systems be used interchangeably?
No, torque ratio is different. DRG torque allows for 3x more torque
3 products that contain DRG torque wrench
- DRG IPG Kit
- Tunneling tool kit
- Lead extension kit
Max implant depth for proclaim DRG IPG
4cm
How many leads can the DRG EPG and IPG accomidate
EPG - 2 leads
IPG - 4 leads
at what levels is the proclaim IPG DRG system MRI conditional
T10 to S2
which DRG lead is MRI Conditional
50 cm slim tip lead
is the proclaim DRG system full body MRI conditional like the SCS proclaim?
No only head and extremities
What to bring to DRG trial
- slim tip lead kit
- EPG header and cable
- EPG base
- accessory kit
- patient and clinician programmer
What to bring to DRG perm
- slim tip lead kit
- EPG header/ base/ cable for intraop testing
- IPG
- Tunneling tool kit
- patient manual / magnet
- patient and clinician programer
For lead placement at T10-L3 where should skin entry be
2-3 pedicles below on contralateral side
What are the order and landmarks that a physician will mark on patient for appropriate needle trajectory and entry
- inferior medial aspect of target pedicle
- Superior and midline aspect of the epidural space
- use those two marks to draw a line to appropriate skin entry point on contralateral side
L4 and L5 needle trajectory tends to be
wider and more contralateral
Which electrode should be under pedicle
2 and 3
Removal process for delivery system
- Sheath
- needle
- stylet
Recommended pulse width and frequency for DRG
Pulse width - 200ms
Freq - 20 hz
RFA stands for
Radio Frequency Ablation
2 types or methods of RF we offer are
- continuous thermal
- pulsed RF
at what temp does tissue damage begin
45 degrees Celsius and above
How many channels or ports does the NT2000 and Ionic have?
both have 4
how many lesions are created using the simplicity
5 lesions
what are the lesions patterns when using simplicity
- Bipolar lesion between distal and medial electrodes
- Bipolar lesion between proximal and medial electrodes
- monopolar lesion at distal
- monopolar lesion at medial
- monopolar lesion at proximal
what gauge RF needles are available
16 g - purple
18 g - pink
20 g - yellow
22 g - black
What length needles are available for RF?
5cm - GREEN
10cm - BLUE
15cm - YELLOW
20cm - ORANGE
Does the Venom electrode by Stryker create bigger or smaller lesion than our 16g
Smaller
RFA is intended to decrease or stop pain originating at what joints
Facet Joints
Grounding pads should be
proximal or close to treatment site and in a well vascularized area
RF competitors
- Medtronic
- Stryker
- Avanos
- Cosman
What kind of stimulation is used to determine if the needle and probe are in good location for RF
Sensory and motor
Pulsed RF creates…
an electromagnetic field which may boost the immune response
1 rule when troubleshooting RFA issues
start with least expensive product to most expensive
Purpose of diagnostic nerve blocks before RF procedure
to ensure the correct nerve is ablated
two types of reusable probes
- stainless steel
- Nitinol
Explain bi-pole lesion
a bi-pole lesion is when 2 needles are place 2-5mm apart. one needle heats up and the other serves to close the circuit therefore no grounding pad is needed
Default settings on RF generator for creating lesions are
80 degrees Celsius for 60 seconds
RFA is indicated for
the destruction of neurolytic tissue
Key differences between NT2000 and Ionic
Ionic is
1. Overall better performing ( high average power output per channel, reliable and consistent)
2. Enhanced safety Features (auto stop lesion if circuit is broken or if high impedances and new grounding pad)
3. modern looking, smaller, lighter, more portable
4. touch screen like Ipad
5. only generator that can be mounted on IV pole
What is the ProCharge Intelligent Power Algorithm
Intelligently distributes power between channels to ramp to temperature quicker and ensure maintenance of temperature throughout lesioning process