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thoracic outlet syndrome
This document provides information on thoracic outlet syndrome (TOS). It begins with a brief history and defines TOS as abnormal compression of the neurovascular bundle in the thoracic outlet. It describes the relevant anatomy and compartments of the thoracic outlet. The document discusses the causes, types, symptoms, and diagnostic approaches for the neurogenic, venous, and arterial forms of TOS. It provides details on conservative and surgical treatment options.
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thoracic outlet syndrome
- 1. THORACIC OUTLET SYNDROME Dr. Nanda gopal Velagapudi Dr. Avinash Katkam Dr Giridhar Boyapati
- 2. First clinical descriptiongiven by A.Cooper 1821 W H Willshire described about cervical rib H Coote first resection of cervical rib. In 1956 Peet introduced the term thoracic outlet syndrome.
- 3. Definition • Thoracicoutlet syndrome (TOS)- a collection of symptoms brought about by abnormal compression of the neurovascular bundle by bony, ligamentous or muscular structers in the narrow space between clavicle and 1st rib – the thoracic outlet.
- 4. • Boundaries ofTO • posteriorly: T1 vertebral body • laterally: first rib and costal cartilage • anteriorly: manubrium sterni
- 6. ANATOMY Interscalene triangle - Inferiorly : 1st rib - Ant : scaleneus anterior - Post : scaleneus medius. Costoclavicular space Ant : clavicle, subclavius muscle Post medial: 1st rib Post lateral: superior border of scapula.
- 9. contents • viscera – thymus – trachea – oesophagus – lung apices • vessels, nerves and lymphatics – common carotid arteries – confluences of internal jugular and subclavian veins – phrenic nerves – vagus nerves – recurrent laryngeal nerves – thoracic duct • prevertebral fascia • muscles – sternocleidomastoid muscle – anterior and middle scalene muscles – sternohyoid muscle – sternothyroid muscle
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- 13. Anatomic sections showthe compartments of tthhee tthhoorraacciicc oouuttlleett Fig. (b) Section obtained after removal of the pectoralis minor muscle shows the neurovascular bundle. C = clavicle, straight black arrow = axillary artery, curved black arrow = axillary vein, white arrow = brachial plexus. Demondion X et al. Radiographics 2006;26:1735-1750
- 14. Anatomic sections showthe compartments of the thoracic outlet Fig. Anatomic sections show the compartments of the thoracic outlet. (a) Section obtained after removal of the pectoralis major muscle shows the costoclavicular space (red oval) and retropectoralis minor space (yellow oval). Pmi = pectoralis minor muscle. Demondion X et al. Radiographics 2006;26:1735-1750
- 15. • Race Noracial predilection exists. • Sex Thoracic outlet syndrome is traditionally more common in women than in men, with a female-to-male ratio as high as 3:1. • Age Thoracic outlet syndrome is most common in people aged 10-50 years
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- 18. Cervical rib •It is a superneumary rib that arises from seventh cervical rib or rarely from sixth or fifth cervical vertebrae. • incidence 0.5-0.6% • Bilateral in 60-80 % • Symptomatic in 10 -15%
- 19. types • Type1small projection from costal faset. Less than 2.5cm • Type 2 projection beyond transverse process. > 2.5cm • Type 3 nearly complete rib which is partly fibrous • Type 4 complete rib with costal cartilage attached to 1st rib or sternum.
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- 21. SSuubbggrroouupp 11 --((nneeuurroollooggiicc ttyyppee)) • –95% of cases This type is secondary to compression of the brachial plexus caused by various soft tissue and bony abnormalities at the point where the nerves pass between the anterior and middle scalene muscles.
- 22. Subgroup 2 -(the venous type): • 3-4% of cases. Venous thrombosis may be categorized into primary and secondary thrombosis based on the etiology. Primary venous thoracic outlet syndrome, or primary venous thrombosis, is also called Paget-Schrötter syndrome named after the 2 individuals who first described this entity: Paget, who described it in 1875, and von Schrötter, in 1884.
- 23. SSuubbggrroouupp 33 ((thearterial type): • 1-2% of cases. This type is associated with the most serious complications, including limb ischemia (which may result in the loss of the affected upper extremity).
- 24. Neurogenic TOS •Etiology – Hyperextension neck injury (whiplash) – Repetitive stress injuries
- 25. Neurogenic TOS •Predisposing Factors – Scalene muscle anomalies – Narrow scalene triangles – Congenital ligaments/bands – Cervical ribs
- 26. Neurogenic TOS •Pathophysiology – Neck trauma stretches and tears scalene muscle fibers – Swelling of muscle belly pain, parathesias, numbness, weakness – Scarring/fibrosis of muscle belly occipital headaches.
- 27. • Symptoms –Pain, parathesias, numbness, weakness throughout affected hand/arm • Not necessarily localized to peripheral nerve distribution – Extension to shoulder, neck, upper back – “Upper plexus” disorders – “Lower plexus” disorders
- 28. Neurogenic TOS •Symptoms – Occipital headaches – Perceived muscle weakness • Actual weakness and atrophy are rare – Vasomotor symptoms • Vasospasm, edema, hypersensitivity (CRPS)
- 29. Neurogenic TOS •Pectoralis minor syndrome – Compression of neurovascular bundle under the pec minor – Pain over anterior chest and axilla – Fewer head/neck symptoms
- 30. Venous TOS •Etiology – Developmental anomalies of costoclavicular space – Repetitive arm activities – throwing, swimming, overhead activities.
- 31. Venous TOS •Predisposing Factors – Relationship of vein to subclavius tendon and costoclavicular ligament – Decrease in dimensions of costoclavicular space • Repetitive trauma to vein causing stenosis, thrombosis
- 32. • Acute occlusion – Pain – Tightness – Discomfort during exercise – Edema – Cyanosis Increased venous pattern Tenderness over the axillary vein Gangrene rarely
- 33. Arterial TOS •Etiology – Cervical or anomalous first rib – Anomalous anterior scalene insertion
- 34. Arterial TOS •Pathophysiology – Arterial compression resulting in post-stenotic dilatation or aneurysm – Distal embolization of thrombus
- 35. Interscalene triangle Artery, Nerves Costoclavicular space Vein Subcoracoid area Artery, Vein , Nerves
- 36. Arterial TOS •Symptoms –Digital or hand ischemia –Cutaneous ulcerations –Forearm pain with use –Pulsatile supraclavicular mass/bruit
- 37. DIAGNOSIS • CClliinniiccaallmmaanneeuuvveerrss • RRaaddiiooggrraapphhyy • UUllttrraassoonnooggrraapphhyy • MMaaggnneettiicc rreessoonnaannccee ((MMRR)) aannggiiooggrraapphhyy • Computed tomographic ((CCTT)) aannggiiooggrraapphhyy • AAnnggiiooggrraapphhyy aanndd vveennooggrraapphhyy
- 38. Adson maneuver Patientis instructed to take and hold a deep breath and extend his neck fully and then asked to turn his head towards the side being examined. Obliteration or diminuation in the radial pulse suggest compression.
- 39. TThhee RRooooss tteesstt • The patient repeatedly clenches and unclenches the fists while keeping the arms abducted and externally rotated (palms forward and upward). The elbows are braced slightly behind the frontal plane for 3mins. • The test is positive when symptoms are reproduced with this maneuver. • A positive test is very suggestive of the thoracic outlet syndrome.
- 40. Hyperabduction maneuver •Evaluates compression of the neurovascular bundle between the coracoid process and the pectoralis minor muscle. • The patient externally rotates the shoulders and extends the arms out from the chest and then above the head.
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- 42. Halsted's Costoclavicular maneuver • Evaluates compression of the neurovascular bundle between the clavicle and the first rib. • The patient assumes an exaggerated military position with shoulders pushed backward and pressed downward.
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- 45. Diagnosis • “themost accurate diagnosis of TOS…must rely on a careful history and thorough, appropriate physical examination” » David B Roos, MD • No single diagnostic test has sufficient specificity to prove or exclude the diagnosis
- 46. DD nTOS •Carpal tunnel syndrome • Ulnar nerve compression or neuritis. • Rotator cuff tendinitis • Cervical spine strain/sprain • Fibromyositis • Cervical disk disease • Cervical arthritis • Brachial plexus injury
- 47. DD aTOS •Other sources of emboli: Cardiac and aortic arch causes, coagulopathies • Vasculitis • Radiation-induced arteritis • Connective tissue disorders • Arterial dissection • Atherosclerotic disease • Traumatic
- 48. Imaging • X-rays – Cervical rib – Elongated C7 transverse process – Hypoplastic 1st rib – Callous formation from clavicle or 1st rib fracture – Pseudoarthrosis of 1st rib • Unable to image soft tissue anomalies and fibromuscular bands – seen only at time of surgery
- 49. • CT/MRI canrule out other pathologies • Magnetic rreessoonnaannccee ((MMRR)) aannggiiooggrraapphhyy and computed tomographic ((CCTT)) aannggiiooggrraapphhyy of the thoracic inlet, especially with recently devised techniques and protocols, are noninvasive modalities that provide image quality comparable to that of angiography and venography.
- 50. • an Angiographyandd vveennooggrraapphhyy remain the criterion standards for the radiologic diagnosis of these conditions, and they have the added benefit of enabling potential endovascular treatment. • MR neurography – newer technology to detect localized nerve function abnormality
- 51. • aTOS –Segmental arterial pressures – Angiography • vTOS – Duplex U/S – Venography • Consider bilateral studies
- 52. EMG/NCS • Reductionin NCV and low amplitude motor responses • Positive results – Confirms the clinical diagnosis – Poor prognosis if true neural damage present • Negative results – Does not exclude TOS Both EMG/NCV have lo sensistivity for TOS
- 53. Electrophysiology Testing •Medial antebrachial cutaneous nerve (MAC) – Lowest branch of inferior trunk of brachial plexus – More sensitive to compression than other branches • Higher sensitivity and specificity with EMG/NCS
- 54. Scalene muscle block • Most useful when diagnosis is unclear • Patient in supine position with neck hyperextended and turned to opposite side. Lateral border of sternocledomastoid is palpated andabout 1.5 inches above the clavicle anterior scalene muscle is palpated.
- 55. • 5- 7mlof plane bupivacaine and 1ml of betamethasone is injected. • Relief of symptoms ranging from few days to weeks. • Good relief of symptoms confirms the diagnosis. • 2-3 injections can be given.
- 56. Treatment Conservative managementaims to increase the space in the thoracic outlet area and to relieve compression on the neurovascular structures. Step 1 proper postural changes and correct faulty postures. Step 2 manipulate and mobilize and relax 1st rib and clavicular, scapular, pectoral muscles. Step 3 strengthen the shoulder girdle muscles and stretch scalene muscles
- 57. Pain control •Muscle relaxants • NSAIDS • Ultrasonography with ionatophorosis • Transcutaneous electric nerve stimulation. (TENS) • Local anesthetic injections.
- 58. Edema control •Edema gloves • Compressive garments • Elevation of limb • Active range of motion exercises • Retrograde massages • Phonophoresis controls pain and edema
- 59. Ergonomics • Workposture related changes • Relative adjustment of chair height so that forearm rests comfortably and without shoulders being elevated or depressed. • Avoid carrying heavy weights on effected side • Avoid hyperextension of neck and hyperabducting postures
- 60. Exercises Involves relaxingshoulder girdle and stretching the scalene and pectoral muscles. Neck : neck side bending exercises neck rotation neck flexion exercises Shoulder : shrugging of shoulders pendulum exercises
- 61. Treatment nTOS •Neck stretching • Posture correction • Avoid neck traction, weights, resistance exercises, strengthening exercises
- 62. Surgical decompression Symptomspersists beyond 2 months of conservative management. Associated vascular compression with poststenotic dialatation. Complete occlusion of a large vessel. Progression of neurological symptoms. Nerve conduction velocity < 60m/s
- 63. • 1st ribresection and scalenectomy are standard procedures for TOS • 1st rib resection is recommended for lower type TOS • Scalenectomy is recommended for upper type TOS • Best results and less chance of recurrence with combined 1st rib resection and scalenectomy.
- 64. Scalenectomy • Incision:8cms incision, 1.5cm above middle third of clavicle. • 80-90% of scalenus anterior muscle and 40-50% of scalenus medius muscle removed. Protect long thoracic nerve and phrenic nerve. Complications : neck hematoma, chylus drainge, dyspnea due to phrenic nerve irritation.
- 65. 1st rib resection 1. Transaxillary approach 2. Supraclavicular approach 3. Infraclavicular approach 4. Posterior approach.
- 66. Transaxillary approach (Roos approach) • Transverse Incision at the level of third rib just below the axillary hair line. – Advantages • Limited field of operative dissection • Cosmetically placed incision • Achieve 1st rib resection and anterior scalenectomy • Removal of anomalous ligaments and fibrous bands. • Less blood loss, no muscles are divided.
- 67. – Disadvantages •Incomplete exposure of entire scalene triangle • Difficulty achieving brachial plexus neurolysis • Limited if vascular reconstruction is needed
- 68. • Supraclavicular approach – Advantages • Wide exposure of all anatomic structures • Permits complete resection of anterior and middle scalenes as well as brachial plexus neurolysis. • Allows resection of cervical ribs and anomalous 1st ribs • Vascular reconstruction is possible
- 69. Infraclavicular approach •ADVANTAGES • Ideal for venous and arterial obstruction. • Venous embolectomy. • Arterial reconstruction. • DISADVANTAGES • Poor view of thoracic outlet. • Poor excision of posterior part of the rib.
- 70. Posterior approach •Advantages • cervical rib can be easily resected. • Sympathetectomy can be done • Disadvantages • Vascular reconstruction can not be performed.
- 71. Thoracoscopic First RibResesction • Three 10mm portal are made -1st anterior 3rd ICS -2nd lateral 5th ICS - 3rd lateral wall of 6th ICS Endoscopic drill is used to dissesct the rib
- 72. Adjunctive procedures –Pectoralis minor tenotomy. – Sympathectomy :
- 73. Treatment vTOS •Anticoagulation therapy with heparin and oral anticoagulants. • Fibrinolytics • Catheter-directed thrombolysis. • Thrombosis is < 3days old : Thrombectomy • Chronic thrombosis : Venous Bypass
- 74. Complications • Nerveinjury bracial plexus injury Long thoracic nerve of bell Phrenic nerve Intercostobrachial nerve. Vagus and Reccurent laryngeal nerve Vascular injury Subclavian vein and artery
- 75. • Thoracic ductinjury Lymphatic fistula Lymphocele Chylothorax Pleural complication pleural damage Pneumotharax Pleural effusion
- 76. Recurrent nTOS •Postoperative scarring most common cause. • Recurrence usually is seen within 3months. • To minimize scar tissue formation patient is instructed to perform active range of motion exercises beginning the day after surgery. Performed every 3-4 hrs for atleast 6 months.
- 77. Initial procedure Recurrent procedure Adequate 1st rib resection scalenectomy More than 1cm of first rib stump. Removal of the stump Brachial plexus neurolysis Subclavian vessel vascolysis. Partial resection of 2nd rib scalenectomy 1st rib resection + Scalenectomy Brachial plexus neurolysis. Adequate coverage of plexus with prescelene fat. Partial 2nd rib resection.
- 78.
Editor's Notes
- #14 Figure 2b. Anatomic sections show the compartments of the thoracic outlet. (a) Section obtained after removal of the pectoralis major muscle shows the costoclavicular space (red oval) and retropectoralis minor space (yellow oval). Pmi = pectoralis minor muscle. (b) Section obtained after removal of the pectoralis minor muscle shows the neurovascular bundle. C = clavicle, straight black arrow = axillary artery, curved black arrow = axillary vein, white arrow = brachial plexus.
- #15 Figure 2a. Anatomic sections show the compartments of the thoracic outlet. (a) Section obtained after removal of the pectoralis major muscle shows the costoclavicular space (red oval) and retropectoralis minor space (yellow oval). Pmi = pectoralis minor muscle. (b) Section obtained after removal of the pectoralis minor muscle shows the neurovascular bundle. C = clavicle, straight black arrow = axillary artery, curved black arrow = axillary vein, white arrow = brachial plexus.