LEA Anatomy 2025

Chapter Overview

• Title: Chapter 4 LEA Anatomy

• Contributors: Ann Marie Kupinski, Caryn Souza Rorabaugh, Tara Bartholomay

Exam Objectives

• List indications for the LEA exam

• List symptoms for the LEA exam

• Define major components of the lower arterial vascular system

• Describe blood vessel wall arrangements

• Identify major vessels of the lower arterial system with ultrasound images

Blood Vessel Walls

• Three Layers of Vessel Walls

  • Tunica Intima

    • Innermost layer

      • Consists of endothelial cell lining with connective tissue beneath

  • Tunica Media

    • Thickest layer

      • Composed mainly of smooth muscle

      • Varying amounts of elastic fibers and collagen

  • Tunica Adventitia

    • Outermost layer

      • Composed of connective tissue, nerve fibers, small vessel capillaries

      • In contact with surrounding tissue

Arterial Characteristics

• Classification of Arteries

  • Arterioles

    • "Stopcocks" of the vascular system

    • Controlled by circular smooth muscle layers

  • Small and Medium-Sized Arteries

    • Approximately 4 mm in diameter

    • Well-developed smooth muscle layers

  • Large Arteries

    • Elastic arteries with less smooth muscle

    • Includes aorta and major branches

Aorta Structure

• Key Features

  • Main artery of the body

    • Arises from the left ventricle

  • Shape: Umbrella handle or candy cane

  • Portions of Aorta:

    • Ascending aorta → Aortic arch → 3 branches:

      • Brachiocephalic artery (branches into right subclavian and common carotid arteries)

      • Left common carotid artery

      • Left subclavian artery

Descending Aorta

• Path and Terminology

  • After the aortic arch, becomes descending thoracic aorta

  • Pierces diaphragm to transform into abdominal aorta

  • Terminates in bifurcation to form the common iliac arteries

Common Iliac Arteries

• Bifurcation

  • Common iliac arteries split into external and internal iliac arteries (EIA and IIA)

  • EIA continues into:

    • Common femoral artery (CFA)

      • Bifurcates into superficial femoral artery (SFA) and deep femoral artery (profunda femoris)

      • SFA becomes the popliteal artery

  • Popliteal artery bifurcates into anterior tibial artery (ATA) and tibioperoneal trunk

    • Tibioperoneal trunk bifurcates into posterior tibial artery (PTA) and peroneal artery

    • Anterior tibial artery descends to become dorsalis pedis artery

Arterial System Path Discussion

• Pathway Overview

  • From aorta to common iliac arteries to external and internal iliac arteries

  • Further transitions from CFA to SFA, popliteal artery, and branching into ATA, PTA, and peroneal artery

Symptoms of Peripheral Artery Disease (PAD)

• Common Symptoms

  • Many individuals have mild or no symptoms

  • Claudication (muscle pain/cramping in legs during exercise, relieved by rest)

    • Pain typically felt in calf and can escalate in severity

  • Intermittent Claudication

    • Symptoms can be associated with specific sites of disease

    • Claudication limited to calf indicates issues with superficial femoral, popliteal, or posterior tibial artery

    • Thigh symptoms indicate common femoral or iliac artery disease

Other Symptoms of PAOD

• Symptoms Include:

  • Coldness in one leg or foot

  • Leg numbness or weakness

  • No or weak pulse in limbs

  • Painful cramping after activity

  • Skin changes such as shiny or scaly appearance

  • Slower toenail growth, sores that won't heal, erectile dysfunction, hair loss on legs

Indications for LEA Exam**

• Detection of stenosis or occlusion in peripheral arteries

• Monitoring previous surgical interventions and disease evaluation

• Evaluation of arterial integrity in trauma

Techniques for Ultrasound Examination

• Remember inversion rules for scale and gain settings for optimized imaging

• Small adjustments to settings can significantly improve diagnostic quality

• Ensure proper angle and movement when positioning ultrasound probes

References**

• Kupinski, A. M., Schifrin, G. The Vascular System. (3rd ed.). Gurnick Academy of Medical Arts, Wolters Kluwer Health, 2022.

• Video References:

  • Blood Flow Direction with Ultrasound and Doppler (Accessed Jan. 16, 2024)

  • Lower Extremity Arterial Duplex Anatomy and Protocol (Accessed Jan. 16, 2024)