WS US Guidance for Head and Neck Chemodenervation Procedures

AAPM&R 2015 Katharine E Alter MD

Zach Bohart MD Elie Elovic MD

Heakyung Kim MD John McGuire MD

Michael Munin MD Jeff Strakowski MD

Faculty/Disclosures • Katharine Alter: Royalties Demos, Honorarium NANA

• John McGuire: speaker fee Allergan • Jeff Strakowski: Royalties Demos Medical Publishing

Handouts

• Handouts are provided online – Review of US guidance techniques for head and

neck BoNT/chemodenervation – Review of US Guidance/Physics * – Review of Evidence comparing various guidance

techniques for BoNT procedures*

• To provide adequate hands on scanning only a brief didactic review will be presented

– Please refer to the online handouts for full handouts

Objectives

• Review of US Basics: • Scanning and Procedural Techniques • Physics: Slides available on Line

• Hands on US Training for Muscle Identification for head and neck chemodenervation procedures

• At the conclusion of the Workshop participants will – Be familiar with ultrasound appearance of key head and

neck muscles/glands – Gain skills in US knobology/transducer handling skills – Be familiar with various US guided procedural techniques

Course Agenda

• Introduction/Review of US Basics & Scanning Techniques/Tips: 15 minutes

• Hands on Scanning: 75 minutes – Demonstration/projection of muscle groups – Followed by practice scanning lead by table

trainers – Table trainers will rotate during the course

Hands On Course Agenda

• US identification of muscles • Neck Muscles/Nerves: 40 minutes

– SCM, Scalenes, Levator Scapulae, Splenius capitus, Trapezius, OCI

• Nerves – Brachial plexus

• Oromandibular Muscles: 15 minutes • Salivary glands: 15 minutes

• Procedural Guidance Techniques – In plane and Out of plane – Demonstration by Faculty – Rotate to this station to practice during down time

Why use US for Chemodenervation Procedures?

• Correctly isolating the target is important for – Efficacy – Minimizing risk/adverse events – Reduce the required effective

dose (potentially) • Traditional localization techniques

have recognized limitations • Comparative studies indicate that

US guidance is more accurate than other techniques

ADVANTAGES OF US GUIDANCE FOR CHEMODENERVATION PROCEDURES

Why you should consider using US for BoNT Injections?

US for BoNT Injections: Advantages • Visualize/isolate target

structures – Quickly – Easily – Accurately

• Less painful – Smaller needles

• Pediatric patients often require no sedation

• Distract patients during procedure

Longituding View SCM

US for BoNT Injections: Advantages

• Improved accuracy when

localization is limited by: – Involuntary muscle activity – Co-contraction – Motor control – Patient cooperation

• US does not require AROM to isolate muscle – Muscle identification is based on

pattern recognition

Upper Motor Neuron Syndromes or Cervical Dystonia

US for BoNT Injections: Advantages Improved accuracy • Localization is limited by

complex or overlapping anatomy

• Very small/large patients – Difficult to estimate

muscle depth

• Identifies safest path to the target – Location – Depth

Transverse View, Lateral Neck

Longitudinal View, Anterior Cervical

US for BoNT Injections: Advantages

• High risk targets – Avoid untargeted

• Muscles • Structures

– Vessels/nerves/organs

• High stakes muscles – SCM – Scalenes – Oromandibular

muscles • Pterygoids

– Subscapularis

Sternocleidomastoid Transverse Scan Out of Plane Injection

Adductors, Transverse Doppler

US for BoNT Injections: Advantages

Focal dystonia • Identify individual muscle

fascicles – Ex: FDS digit 3 vs. 4

• Increased accuracy and speed when identifying muscle fascicles

• Reduced pain – Smaller needles

FDS longitudinal view, mid forearm Short axis view of needle

Longitudinal View, FDS

US for BoNT Injections: Advantages

• Non-muscle targets: – Salivary Glands – Prostate

• Salivary gland: – Correct localization is

critical to reduce the risk of dysphagia

• EMG and E-Stim do not help localization of non-muscle targets

Parotid

Submandibular

US for BoNT Injections: Advantages

• Visualize injectate – Confirms correct site – Provides info on volume of

injectate/distension of muscle

• Reduces risk of over injection at one site

– Minimize spread to adjacent muscles or structures

SCM, Longitudinal View, In Plane Injection VIDEO from Michael C Munin MD

US for Chemodenervation Procedures: Advantages

US + E-Stim for Nerve Blocks Interscalene block • US speeds the localization

of a nerve or nerve branch • Reduces risk of nerve injury • Reduces risk of tissue

damage when injecting phenol

• Reduces risk of injury to organs, vessel penetration

Ultrasound and Procedural Guidance

Disadvantages • Equipment related factors

– Availability – Cost

• Clinician related factors – Lack of experience/training – Limited access to training

specific for chemodenervation – Steep learning curve

Transverse view, proximal forearm

Ultrasound for Chemodenervation: Summary

• Localization techniques – Palpation – EMG – Nerve stimulators – Ultrasound

• All have advantages & disadvantages

• Best Strategy: – Be skilled in multiple techniques – Be aware of

– The limitations of each technique – Evidence supporting/refuting the

accuracy of the various techniques

Comparison of Injection Techniques

Palpation EMG Stimulation Sonography

Accuracy +/- +/- + +++

Practicability + - +/- ++

Availability +/- +/- +/- +

Pain + - +/- +++

Speed +/- - +/- ++

Evaluation +/- - +/- +++

Future research - - - +++

ULTRASOUND BASICS

ULTRASOUND PHYSICS See online handout for review

Ultrasound Equipment Basics:

• Soundwaves are produced by piezoelectric crystals – Cystal arrays are placed

into transducers • Transducers

– Determine the frequency of US waveform ( λ)

– Frequency of US λ determines

• Depth of penetration • Resolution of the image

Ultrasound: Transducer Selection • Select size and shape to match

the clinical application • Size/Shape of transducer

– Linear: • Best for flat surfaces

– Curvilinear: • Best for abdomen/pelvic/GYN

– Hockey stick: • Hand • Small irregular surfaces

US Basics: Transducer Frequency MHz Depth/Penetration Application 3 12-20 cm OB/GYN 5 12-15 cm Deep muscles 7.5 8-10 cm Leg 10 5cm Forearm 12-17 3.5- 2cm Hand, face

Select transducer to match required penetration depth • 12-17 MHz for superficial structure

– Hand, forearm • 3-5 MHz for deep muscles

– Piriformis, iliacus, quadratus lumborum • Most transducers have mixed frequencies

– 3-5, 7-12 etc

Transducer Handling/Orientation

• To correctly orient the transducer on the patient – Look for a manufacturer’s

mark on one end of the transducer

– The marked end = screen left on display

– To confirm this orientation: • Tap the end of the

transducer to confirm the orientation

Notched end

US Basics: View convention

• Top of image is superficial – i.e. skin

• Bottom deeper structures • Transverse view

– Conventions vary • Right always to patient right • Medial always to right

• Longitudinal view – Left proximal – Right distal

Superficial

Deep

Patient R or Medial

Patient Left or Lateral

Transverse view, Anterior Neck

US Basics: View convention

Longitudinal view Convention • Place the transducer on the

patient so that – Proximal = screen left – Distal = screen right

SCM

Distal Proximal

Superficial

Deep

US Basics: Transducer Orientation

Long Axis of Transducer Short Axis of Transducer

Weak scattering from blood and fluids with low impedance to US λ Tissues will appears dark or hypoechoic

US Appearance of a Tissue is Determined by its Acoustic Impedance

“Speckle” from scattering in tissue. L~ λ

Strong echoes from “mirror-like” interfaces will appear bright or hyperechoic

US Basics: Tissue Properties • Muscle

– Hypoechoic background (contractile elements/fascicles)

– Interspersed hyperechoic bands of fibroadipose tissue

• Long axis – CT appears as parallel

hyperechoic lines, less uniform than in tendon

• Short Axis – CT intramuscular tendons,

aponeurosis appear as bands and streaks

Transverse view

Longitudidal view

Transverse view

Holding the transducer

• Grasp the transducer lightly using your – Thumb + index or – Thumb + index+ middle

finger – Do not over grip

• Keep hand in contact with the patient at all times to avoid slipping – Using heel of hand or 4th

and 5th finger

Incorrect : No contact with patient

Correct : Maintaining contact with patient

Anatomic Plane/Transducer Orientation

• Be aware that the – Anatomic plane and

transducer orientation may not always match

• Example – Pronator Quadratus

Pronator Quadratus Longitudinal Muscle Scan Transverse Upper Limb Scan

Pronator Quadratus Transversel Muscle Scan Longitudinal Upper Limb Scan

Scanning Tips/Techniques: Injection Techniques

• In plane/long Axis needle view: – Keep needle parallel to

transducer – Insert needle at flat

angle – Poor needle visualization

• Oblique position • Steep angle needle

Scanning Tips/Techniques: Injection Techniques

• Out of plane/short axis needle view: – Keep needle tip under

US beam • If needle tip is outside of

US beam, visualization is lost

• May be in untargeted structure or muscle

– Walk down technique • Follow movement of

needle tip passing through tissues planes to target

• Real time injection • Whatever technique is

used: – Keep needle within the

ultrasound beam – If needle tip is outside of

the narrow US beam visualization is lost

• Tip may not be in target structure

Interventional MS Ultrasound: Clinical Pearls

Interventional MS Ultrasound: Pearls of Wisdom

• Larger needles are easier to see than small needles – Larger needles hurt more – 27g needles are easily seen particularly in an in plane view – Non-insulated needles are visualized better than insulated. Etched

Needles are also available • Small amount of air (.2-.3 ml) helps define needle location • Agitate injectate: increases reflection from bubbles

– Agitating may denature the toxin • Billing: In the USA, to charge/bill for US, a picture or cine-

loop must be saved to document the procedure • Billing Code: 76942: Ultrasound for Needle guidance, aspiration

US Muscle identification

• Identification of muscles is based on pattern recognition of – Contour lines – Adjacent structures

• Bones • Vessels • Other muscles

– Real-time • Use AROM/PROM to

assist muscle identification

Pronator teres FCR

US Scanning Demonstration

• Transducer handling/manipulation • Scanning limbs/structures • Injection Techniques

– In plane – Out of plane

Hands On Session Hands On Ultrasound Session: • 6 Ultrasound Stations

• Wrap Up/Final questions – Panel

• Demonstration/Scanning • Neck

– SCM – Scalenes – Levator Scapulae – Splenius Capitus – trapezius

• Oromandibular – Masseter, Ptyergoids

• Salivary gland – Parotid, Submandibular

Hands On Course Agenda

• Demonstration/projection of muscle groups • Following the demonstration each group will

practice scanning – The following key muscles will be demonstrated

• Pectoralis Major/Subscapularis • Biceps/Brachialis • FCR/Pronator Teres/FDS • SCM/Scalenes • Parotid/Submandibular • Procedural Guidance Techniques

Neck Muscles

Pages From Ultrasound Guided Chemodenervation Procedures, Text and Atlas, Demos Medical Publishing, Used with Permission

Neck Muscles

Pages From Ultrasound Guided Chemodenervation Procedures, Text and Atlas, Demos Medical Publishing, Used with Permission

Neck Muscles

Levator Scapulae Trapezius

Oromandibular Muscles

Masseter Medial/Lateral Ptyergoid

Salivary Gland

Pages From Ultrasound Guided Chemodenervation Procedures, Text and Atlas, Demos Medical Publishing, Used with Permission