Surface Anatomy and Sonoanatomy for the Occasional Regional Anesthesiologist Edward R. Mariano, M.D., M.A.S. Professor of Anesthesiology, Perioperative & Pain Medicine Stanford University School of Medicine Chief, Anesthesiology and Perioperative Care Veterans Affairs Palo Alto Health Care System @EMARIANOMD
Financial Disclosures Halyard Health, B Braun Unrestricted educational program funding paid to my institution The contents of the following presentation are solely the responsibility of the speaker without input from any of the above companies.
Learning Objectives Define optimal ultrasound transducer position for cross-sectional imaging of nerves Apply surface anatomic landmark identification in ultrasound transducer application Identify sonoanatomy of common peripheral nerves and surrounding structures Discuss tips and tricks to improve ultrasound images and block techniques
How Hard Can It Be? NYSORA.COM -
Lesson #1
Lesson #2 Regional anesthesia is applied anatomy
History of Nerve Localization Anatomic landmarks Fascial clicks or pops Electrical nerve stimulation Sustained twitch at < 0.5 ma current suggests appropriate needle position Ultrasound
Overview Introduction to ultrasound Surface anatomic landmarks Relevant gross anatomy Traditional nerve block techniques Sonoanatomy for nerve blocks
Overview Introduction to ultrasound Surface anatomic landmarks Relevant gross anatomy Traditional nerve block techniques Sonoanatomy for nerve blocks
Basic Sonoanatomy Blood vessels: hypo-echoic (dark) Muscles: hypo- > hyper-echoic (striations) Bone and fascia: hyper-echoic (white) Nerves: hypoechoic Connective tissues are hyperechoic (epineurium, perineurium)
A Closer Look at the Nerve Short-Axis View
The A.R.T. of Target Imaging A lignment R otation T ilt
Alignment: Where Do We Look?
Optimal Rotation
Optimal Rotation
Optimal Tilt
Optimal Tilt
Overview Introduction to ultrasound Surface anatomic landmarks Relevant gross anatomy Traditional nerve block techniques Sonoanatomy for nerve blocks
Interscalene Block: How We Did It Needle inserted in IS groove at C6 Antero-lateral approach Needle angle 30-45º Elicit motor response (deltoid, biceps, triceps, pectoralis) Borgeat A, et al. Anesth 2003:99:436
Interscalene Anatomy Position: supine with head turned away SCM clavicular head Interscalene groove posterior to SCM at cricoid level (C6) External jugular vein Subclavian artery Cricoid Subclavian Art
Interscalene Sonoanatomy Transverse Short-Axis View SCM ASM BP MSM CTP Mariano ER, et al. JUM 2010;29:329
Infraclavicular Block: How We Did It Insertion 2 cm medial and 2 cm caudad to CP Needle inserted plumb-bob Avg depth 4.24±1.49 cm in men, 4.01±1.29 cm in women Wilson JL, et al. A&A 1998;87:870
Infraclavicular Anatomy Position: supine with arm at side or abducted 90 Palpate coracoid process below the clavicle Plexus runs under coracoid process Coracoid
Infraclavicular Sonoanatomy Transverse Short-Axis View PMa PMi N AA N N AV Mariano ER, et al. JUM 2009;28:1211
Femoral Nerve Block: How We Did It Needle insertion: lateral to artery at 45 angle aiming cephalad Feel 2 pops Proper motor response = quad contraction Ilfeld, BM, et al. Anesth 2008;108:703
Femoral Anatomy Position: supine with roll under hip Leg straight Inguinal crease Femoral artery Femoral nerve is lateral to femoral artery
Femoral Sonoanatomy Iliacus N FI FA FL Mariano ER, et al. JUM 2009;28:1453 Transverse Short-Axis View
Adductor Canal Anatomy Position: supine with thigh externally rotated and knee slightly flexed Subsartorial tunnel begins distal to the apex of the femoral triangle Saphenous nerve runs with superficial femoral artery Horn JL, et al. RAPM 2009;34:486 Manickam B, et al. RAPM 2009;34:578
Adductor Canal Ultrasound Transducer placed along medial aspect of thigh distal to inguinal crease Short-axis view Landmarks Sartorius (S) muscle Saphenous (N) Femoral artery (A) Sartorius N A Mariano ER, et al. JUM 2014;33:1653
Popliteal Fossa Block: How We Did It Insertion site: 8-10 cm cephalad to popliteal crease or at intertendinous junction 4 needle angled 45 cephalad Plantar flexion or inversion preferred Hadzic A, et al. A&A 2002;94:1321
Popliteal Anatomy Position: prone with knee slightly flexed Popliteal crease Biceps femoris laterally Semimembranosus and semitendinosus medially Intertendinous junction
Popliteal Sonoanatomy Transverse Short-Axis View BF N F Mariano ER, et al. RAPM 2009;34:480
Transversus Abdominis Plane Anatomy
TAP Sonoanatomy Transverse Short-Axis View EO IO TA
Summary We defined optimal ultrasound transducer position for cross-sectional imaging of nerves We applied surface anatomic landmark identification in ultrasound transducer application We identified sonoanatomy of common peripheral nerves and surrounding structures We discussed tips and tricks to improve ultrasound images and block techniques