Arterial.11.Thoracic outlet syndrome Flashcards
DEFINITION of Thoracic Outlet Syndrome
This is a neurovascular syndrome due to compression of the roots of the brachial plexus & the subclavian artery, as they pass from the neck to the axilla through a narrow triangle bounded by :
- The scalenus anterior muscle.
- The scalenus medius muscle.
- The 1st rib.
affection of subclavian vein in Thoracic Outlet Syndrome
- The subclavian vein passes anterior to the scalenus anterior muscle outside this triangle
- thus it is rarely affected in this syndrome.
ETIOLOGY of Thoracic Outlet Syndrome
- Cervical rib syndrome
- Scalene syndrome
- Post fixation of the brachial plexus (C6-T2).
- Malunion of fracture clavicle 1%
- Tumour or infection of the 1st rib.
- Pancoast tumour.
Cervical rib syndrome in ETIOLOGY of Thoracic Outlet Syndrome
- Definition
- Side
- Anatomical types of the cervical rib
Definition of Cervical rib syndrome in ETIOLOGY of Thoracic Outlet Syndrome
Presence of an extra rib Arising from C7
Side of Cervical rib syndrome in ETIOLOGY of Thoracic Outlet Syndrome
- Bilateral or unilateral
* RT> Lt
Anatomical types of the cervical rib in Cervical rib syndrome in ETIOLOGY of Thoracic Outlet Syndrome
a) Complete rib.
b) Incomplete rib : Ending in a tapering point, which is connected by a fibrous band to the scalene tubercle of 1st rib.
c) Fibrous band
Scalene syndrome in ETIOLOGY of Thoracic Outlet Syndrome
Scalene muscle abnormalities :
a) Hypertrophy of the scalenus medius muscle
b) Abnormal insertion of the 2 scalene muscles with narrowing of the space left between them.
c) A rudimentary muscle (scalenus minimus)
A rudimentary muscle (scalenus minimus) in Scalene syndrome in ETIOLOGY of Thoracic Outlet Syndrome
- arising from the C7 transverse process
* inserted into the 1st rib.
Brachial plexus originates from
C5 - T1 roots
pre fixation of the brachial plexus
C4 - C8 roots
Post fixation of the brachial plexus
C6 - T2 roots
CLINICAL PICTURE of Thoracic Outlet Syndrome
3 groups of symptoms are encountered :
(1) Arterial symptoms :
(2) Nerve-pressure symptoms : Commonest presentation
(3) Venous symptoms :
(4) Local symptoms (Rare) :
Arterial symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
A- Chronic U.L ischemia
B- Raynaud’s phenomenon.
C. In complicated cases
Chronic U.L ischemia in Arterial symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
Intermittent claudication pain of the U.L with exercise & relieved by rest
sensation of coldness, numbness or paraesthesia.
complicated cases in Arterial symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
- The intermittent compression produces atheromatous changes in the artery and post-stenotic aneurysmal dilatation.
- Within this aneurysmal dilatation thrombosis may occur
- Showers of emboli may be dislodged into the peripheral circulation causing gangrene of the finger tips especially the index.
Nerve-pressure symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
Incidence
Pathogenesis
Clinical picture
Incidence of Nerve-pressure symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
Commonest presentation of Thoracic Outlet Syndrome
Pathogenesis of Nerve-pressure symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
Due to irritation of the lower trunk (C8 & T1) of brachial plexus
Clinical picture of Nerve-pressure symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
- Symptoms
* Examination
Symptoms in Clinical picture of Nerve-pressure symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
Shooting pain with tingling & numbness over the ulnar side of hand & forearm.
Examination in Clinical picture of Nerve-pressure symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
Weakness, atrophy of the thenar & hypothenar muscles & clawing of the hand.
Venous symptoms in CLINICAL PICTURE of Thoracic Outlet Syndrome
- Edema & varicosities.
* DVT of the subclavian vein
Local symptoms (Rare) of Thoracic Outlet Syndrome
- Incidence
* List
Incidence of Local symptoms of Thoracic Outlet Syndrome
Rare presentation of Thoracic Outlet Syndrome
List of Local symptoms of Thoracic Outlet Syndrome
Supraclavicular tenderness or less commonly mass
Examination of Thoracic Outlet Syndrome
(1) General examination
(2) Adson’s deep breathing test
General examination in Examination of Thoracic Outlet Syndrome
Weak radial pulse on the affected side.
Hypoesthesia in medial side of forearm & hand.
Wasting of the thenar & hypothenar eminences
May be a palpable cervical rib or aneurysmal dilatation of the subclavian artery in the root of the neck
Auscultation of the distal part of the subclavian artery may reveal systolic bruit.
Adson’s deep breathing test in Examination of Thoracic Outlet Syndrome
The arm is pulled down, the radial pulse is palpated while the patient is requested to turn the head as far as possible towards the side of the symptoms, to elevate the chin & to take a deep breath & to hold it.
In thoracic outlet syndrome, there is loss of radial pulse.
INVESTIGATIONS of Thoracic Outlet Syndrome
(1) Plain X-rays neck & chest
(2) subclavian artery angiography
(3) Electromyography
(4) MRI
Plain X-rays neck & chest in INVESTIGATIONS of Thoracic Outlet Syndrome
- Cervical rib.
- Malunion of fracture clavicle.
- Tumour or infection of the 1st rib.
- Pancoast tumour.
Electromyography in INVESTIGATIONS of Thoracic Outlet Syndrome
for detecting sites of nerve compression
TREATMENT of Thoracic Outlet Syndrome
Treatment of the cause :
I- Cervical rib syndrome or scalene syndrome
II- Malunion of fracture clavicle :.
III- Pancoast tumour:
TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
A. Conservative
B. Operative
Conservative TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
- Indications
* Regimen
Indications of Conservative TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
Mild cases where sensory manifestations are the main complaint
Regimen of Conservative TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
- Medical treatment.
* Physiotherapy.
Operative TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
- Indications
* Modalities
Indications of Operative TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
- Severe pain,
- Vascular disturbances.
- Muscle wasting.
Modalities of Operative TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
- Scalenotomy
- Excision of the cervical rib with its periosteum
- Cervico-dorsal sympathectomy :
Principle of Scalenotomy in Modalities of Operative TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
Division of scalenus anterior at its insertion
insertion of scalenus anterior
scalene tubercle
indication of Cervico-dorsal sympathectomy in Modalities of Operative TREATMENT of Cervical rib syndrome or scalene syndrome in TREATMENT of Thoracic Outlet Syndrome
Marked Trophic changes
Treatment of Malunion of fracture clavicle in TREATMENT of Thoracic Outlet Syndrome
Osteotomy & internal fixation.
Treatment of Pancoast tumour in TREATMENT of Thoracic Outlet Syndrome
Radiotherapy