Anatomy of the Upper and Lower Extremity Arteries





Introduction


A solid familiarity of the anatomy of the upper and lower extremity arteries is required for the evaluation of arterial disease. This chapter provides an overview of the upper and lower extremity arterial anatomy. Normal anatomy, common variants, and major collateral routes are depicted by representative arteriograms and illustrations and supplemented with computed tomography (CT) and magnetic resonance (MR) angiography.


Noninvasive imaging is the preferred modality for the initial diagnosis of peripheral arterial disease. CT, magnetic resonance imaging (MRI), and ultrasound are commonly utilized to evaluate patients with signs and symptoms of extremity arterial occlusive disease. Conventional catheter arteriography, although still considered the gold standard for diagnosis, is typically reserved for the treatment of vascular disease. We present angiographic images in this chapter to display arterial anatomy as they are well suited to depict anatomic detail.


The following terms are used to describe extremity anatomy in this chapter. The arm is the portion of the upper extremity between the shoulder and elbow. The forearm is the portion between the elbow and wrist. The thigh is the portion of the lower extremity between the hip and knee, and the calf is the portion between the knee and ankle.




Upper Extremity


Normal features


The normal arterial anatomy of the upper extremity is depicted in Fig. 11.1 . Figs. 11.2 to 11.5 are detailed arteriographic views of specific regions of the upper extremity arterial tree, beginning at the aorta and extending to the digits. Please review these figures carefully because their legends provide the instructional content.




FIG. 11.1


Arterial anatomy of the upper extremity. Note that the internal thoracic arteries (previously internal mammary arteries), which are tributaries of the subclavian arteries, are used commonly for coronary artery bypass. The deep palmar arch arises from the radial artery, and the superficial palmar arch arises from the ulnar artery. These arches may or may not communicate with each other. a. , Artery; L , left; R , right.



FIG. 11.2


The aortic arch connects the ascending aorta ( AAo ) with the descending aorta ( DAo ). Three great vessels originate from the aortic arch; the innominate artery ( In ) originates on the right side of the arch, followed by the left common carotid artery ( LCC ) and the left subclavian artery ( LSu ). The innominate artery divides into the right common carotid artery ( RCC ) and the right subclavian artery ( RSu ). The right and left vertebral arteries ( RV , LV ) originate from the subclavian arteries, even though this is not apparent on the right side of this illustration. The internal thoracic artery ( IT ), previously called the internal mammary artery, also arises from the subclavian artery.



FIG. 11.3


The subclavian artery ( Su ) becomes the axillary artery ( Ax ) at the lateral margin of the first rib. The axillary artery, in turn, becomes the brachial artery ( B ) after crossing the inferolateral margin of the teres major muscle. The thyrocervical ( TC ) and costocervical ( CCT ) trunks are noteworthy branches of the subclavian artery because they may be mistaken for the vertebral artery ( V ) during duplex examination. The multiple branches that supply the scapular musculature can act as collaterals when the subclavian or innominate arteries are obstructed. CH , Circumflex humeral artery; DB , deep brachial artery; DS , dorsal scapular artery; IT , internal thoracic artery; SS , subscapular artery.



FIG. 11.4


(A) Arterial anatomy and (B) osseous landmarks at the elbow. The brachial artery ( B ) divides at the elbow, forming the radial ( R ) and ulnar ( U ) arteries. The interosseous artery ( I ) is a branch of the ulnar artery, which in some individuals continues to the wrist. RR , Recurrent radial artery; UR , ulnar recurrent artery.



FIG. 11.5


The radial artery ( R ) terminates in the deep palmar arch ( dp ; black arrows ). The deep palmar arch is formed by the terminal or deep palmar branch of the radial artery and one or more branches of the ulnar artery. The ulnar artery ( U ) is the main contributor of the superficial palmar arch ( su ; white arrowheads ). In about one-half of cases, the superficial palmar arch is formed by the anastomosis of the ulnar artery with the superficial palmar branch of the radial artery. In roughly the other half of cases, the superficial palmar arch is formed by the ulnar artery alone and has a “hockey stick” appearance, as shown in this image. The metacarpal ( MC ) arteries arise from the deep palmar arch and the three common palmar digital ( CPD ) arteries are branches of the superficial palmar arch. Metacarpal arteries communicate with common palmar digital arteries at the level of the metacarpal heads. The common palmar digital arteries give off the proper palmar digital arteries ( PD ).


Anatomic variants


Many anatomic variants can occur in the arterial tree of the upper extremities. The more commonly encountered variants are presented in Table 11.1 . Variations in palmar arch anatomy are commonly seen ( Fig. 11.6 ). Many different potential variations involve both the superficial and deep palmar arches. These variants are important in the evaluation of radial artery anatomy for radial artery harvesting. The most common arrangement is completion of the superficial palmar arch on the radial side. In some individuals, the radial artery fails to communicate with the superficial palmar arch. Familiarity with these variants can prevent confusion and error during duplex examination. An example of an upper extremity anatomic variant is presented in Fig. 11.7 .



TABLE 11.1

Arterial Variants of the Upper Extremity.


































Structure Variant Frequency
Aortic arch and great vessels Common origin of the right brachiocephalic and left common carotid arteries 22%
Left vertebral artery origin directly from the aorta 4%–6%
Common origin of both common carotid arteries <1%
Arm and forearm Radial artery origin from the axillary artery 1%–3%
Early division of the brachial artery:
1. High origin of the radial artery (see Fig. 11.7 )
2. Accessory (duplicated) brachial artery		 19%
Ulnar artery origin from the brachial or axillary artery 2%–3%
Low origin (5–7 cm below elbow joint) of ulnar artery <1%
Persistent median artery 2%–4%



FIG. 11.6


Variants of superficial palmar arch anatomy. (A) The closed superficial palmar arch is the most common arrangement with ulnar dominant supply to all digits in 80% of instances. Variations may be due to (B) an incomplete or (C) absent superficial palmar branch. In this last example, all fingers are supplied by branches of the ulnar artery. a , Artery.







FIG. 11.7


High origin of the radial artery. Arteriograms of the (A) arm and (B) forearm demonstrate a high origin of the radial artery ( R ; arrows ) at the mid level of the humerus. B , Brachial artery; I , interosseous artery; U , ulnar artery.


Collateral routes


Many of the branches and tributaries seen in Figs. 11.1 to 11.7 may serve as collaterals when the main arterial trunks of the upper extremity are blocked.


The following is a summary of the more common collateral routes:



  • 1.

    Obstruction of the proximal subclavian or brachiocephalic arteries:



    • a.

      collateral flow from cranial and/or neck arteries to the subclavian artery distal to the obstruction (e.g., subclavian steal phenomenon)


    • b.

      collateral flow from pelvic, abdominal wall, and thoracic wall arteries to the subclavian artery distal to the obstruction



  • 2.

    Obstruction of the distal subclavian or axillary arteries:



    • a.

      collateral flow from the thoracic wall or shoulder region to the axillary artery distal to the obstruction



  • 3.

    Obstruction of the brachial artery or its branch vessels:



    • a.

      collateral flow from the distal arm to the proximal forearm


    • b.

      collateral flow from the midarm to the distal arm and/or forearm


    • c.

      retrograde flow filling the palmar arches of the hand




Fig. 11.8 shows an example of collateralization in response to radial artery occlusion.


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Jan 2, 2020 | Posted by in ULTRASONOGRAPHY | Comments Off on Anatomy of the Upper and Lower Extremity Arteries

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