Arterial Thoracic Outlet Syndrome: A case report

Mithun Chakkaravarthi. P

1st year Vascular Resident, Department of Vascular and Endovascular surgery, Kauvery Hospital

Case presentation

Chief Complaints

A 59 years old male working as a goldsmith had the following complaints,

Pain – left upper limb since 7 days

Coldness – left hand since 1day

Numbness – all fingers of left hand since 1day

History of Presenting Illness

Patient was apparently well 7 days back

Developed pain over the left deltoid region

  • Acute in onset
  • Pricking type
  • Intermittent
  • Aggravated by routine activities
  • Relieved with medications, physiotherpy
  • No rest pain

No h/o

Symptoms in the opposite arm /hand

Pain in the leg on walking

Past history

K/c/o HTN since 2 years on medication- Tab. Stamlo

No history of previous hospitalisation/ surgery

General Examination

Patient conscious, oriented, moderately built

HR – 94/min, regular rhythm, BP: 150/80 mm Hg in right upper limb

BP – Left upper limb not recordable

RR – 20/min

Temperature – Afebrile

Systemic examination – No abnormality detected.

Local Examination – Left Upper Limb

  • Left forearm muscle wasting present
  • Left hand grip- 4/5
  • Left hand- Cold
  • CRT >3 sec
  • Left hand Sp02- 54%

Clinical Picture

Pulse Examination

PulseRightLeft
CCA++
Subclavian+Prominent
Axillary+-
Radial+-
Ulnar+-

Hand Held Doppler

  • Left SCA- Thump present
  • Left Brachial- Monophasic
  • Left Radial and Ulnar- No flow
  • No sensory and motor disturbance

 

Provisional Diagnosis

  1. Acute limb ischemia- left upper limb
  2. Rutherford Class-2A

Differential Diagnosis

  1. Cardiac embolus
  2. Atherosclerotic plaque rupture
  3. Arterial dissection
  4. Subclavian aneurysm

Investigations

Bloods- Normal

X Ray- Bilateral Cervical rib

CT Angiography

3D Reconstruction

Surgery

  • Left cervical rib excision
  • Subclavian aneurysm excision and repair with interposition unigraft
  • Brachial thrombectomy
  • Distal ulnar thrombectomy
  • Vein patch closure

Surgery Steps

  1. Marking of incision
  2. Mobilization of scalene fat pad
  3. Anterior scalenectomy
  4. Middle scalenectomy
  5. Preservation of vital structures
  6. Cervical rib excision
  7. Excision of subclavian artery aneurysm segment with unigraft dacron repair
  8. Brachial thrombectomy and distal ulnar thrombectomy with vein patch closure

Surgical Technique

Intra Op Incision Markings

Scalene Fat Pad Mobilisation

Thrombus inside SCA

SCA Aneurysm Repair with interposition unigraft

Brachial Thrombectomy

Post Op Status

  • Left hand warm and viable
  • Spo2 -98 % in all fingers
  • Brachial, ulnar pulse felt
  • Capillary refilling improved
  • Discharged with Tab Eliquis 2.5mg BD
  • Follow up –doing well

Etiology of Thoracic Outlet Syndrome

  • Compression of neurovascular structures
  • Misdiagnosed
  • Neurological 95%
  • Venous 4%
  • Arterial 1%

Anatomy

The anatomy of the thoracic outlet is defined by the bony circle of the sternum in front, connected to the first rib laterally which attaches to the vertebra posteriorly.

The clavicle attaches to the first rib and sternum anteriorly.

  • It consists of three spaces:
  • Interscalene triangle space
  • Costoclavicular space
  • Pectoralis Minor space

Interscalene triangle

  • This is the most commonly involved Space, which is bordered medially by 1st rib, anteriorly by Clavicle and scalenus anterior muscle and posteriorly by scalenus medius.
  • Anterior and middle scalene muscles have their insertion in the first rib.
  • The brachial plexus and subclavian artery pass through this space.

Costoclavicular Space/triangle

The space is bordered anteriorly by middle third of Clavicle and subclavius muscle, posteromedial wall is formed by 1st rib and posterolateral aspect is covered by superior border of scapula.

The subclavian vein passes through this space and enters into subcorocoid space.

Congenital abnormalities, trauma to clavicle or first rib can cause compression of structure passing by.

Subcorocoid Space/ Pectoralis minor space

The border contains superiorly by coracoid process, anteriorly by Pectoralis minor and posteriorly by Ribs 2nd to 4th.

Shortening of Pectoralis minor can lead to compression and narrowing of space, which is seen in hyper abduction of GH joint.

 

Pathophysiology

Arterial complications –bony abnormalities in all cases

Clinical Assessment

  • Young age
  • Unilateral
  • Bruit
  • Palpable cervical rib
  • Pulsatile supraclavicular mass
  • Microembolization
  • Splinter haemorrhages

Signs and Symptoms

  • Hand ischemia
  • Unrecognised most times
  • Exertional arm pain
  • Subclavian thrombosis
  • Stroke

Differential Diagnosis

  • Cardiac embolus
  • Aortic arc embolization
  • Vasculitis
  • Takayasu arteritis

Surgical Treatment Principle

  • Relieve
  • Remove
  • Reconstruct
  • Degree of arterial damage and distal outflow

Overall Algorithm

Complications

  • Pneumothorax
  • Hemothorax
  • Chyle leak
  • Brachial plexus injury
  • Injury to surrounding structures
  • Cervical sympathetic chain injury –Horner’s Syndrome

Summary

  • Any middle aged male/female with upper limb symptoms without risk factors- suspect Arterial TOS
  • Diagnosis
  • Treatment guided by arterial damage and distal embolization.
  • Always surgery
  • Prompt detection and meticulous surgery will have good outcome.

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