THORACIC OUTLET SYNDROME (T.O.S)

Transcription

1 1 By Dr DG Harris THORACIC OUTLET SYNDROME (T.O.S) WHAT IS THORACIC OUTLET SYNDROME? The thracic utlet is the upper aperture f the chest, between the cllar bne and the first rib.this narrw passageway is crwded with bld vessels that run ut f the chest t the arm (subclavian vein and artery), as well as the nerves that exit the spine in the neck t supply the arm. The nerves fuse t frm 3 large trunks (Brachial Plexus) and these run thrugh the thracic utlet and split up again int separate nerves lwer dwn. Thracic utlet syndrme refers t the symptms that arise when these nerves r bld vessels are cmpressed at the thracic utlet. WHERE DOES THE COMPRESSION OCCUR, AND WHY? The thracic utlet is brdered by the cllar bne at the tp and frnt, the first rib belw and tw muscles, ne in the frnt, and anther behind. These muscles are called scalene muscles, and their functin is t stabilise the first rib. They run frm the spine, higher up and run dwnwards, and are attached t the first rib, ne in the frnt and the ther at the back f the rib. The brachial plexus nerves and subclavian artery pass thrugh the triangle frmed between the first rib and scalene muscles. The subclavian vein lies in frnt f the first scalene muscle and behind the cllar bne. Enlargement f the muscles, as well as scar tissue between them can cmpress the structures. The muscles may enlarge due t muscle imbalance fllwing a shulder injury r peratin, and repetitive mvements that exercise the muscle, such as certain sprts, and certain wrk activities. Sprt activities include swimming, ball thrwing (cricket), and rugby. Typical jbs that predispse t enlargement f these muscles are thse where the arms are elevated a lt, such as mechanics, hairdressers, and schlteachers (writing n blackbard). It is nt uncmmn in musicians.

2 2 Incrrect weight training may cause a muscle imbalance. A sft tissue injury (sprain) t the muscle can cause scar tissue. Cngenital cnditins such as abnrmal bands that run ver the nerves r between the muscles and an extra rib in the neck are ther causes. Anther area f cmpressin is between the cllar bne and the first rib. Clavicle fractures may predispse t later scar frmatin, which may cmpress the structures later n. Fractures f the first rib may cause immediate damage t the brachial plexus, as it runs ver the rib, making cntact with it as it ges t the arm. If there is n immediate damage, symptms may gradually develp later, as scar tissue grws arund the rib, and encases the nerves and artery. Sme peple may have a very thick first rib, causing cmpressin between it and the cllar bne. The third area f cmpressin may be further dwn, belw the cllar bne, where cmpressin ccurs by a thick pectralis minr muscle where it attaches t the shulder blade (scapula). Pr psture and besity may aggravate the cnditin. It ccurs classically in females, with lng necks, and drping shulders, as well as in stcky, muscular peple. A painful shulder fllwing trauma r surgery may cause the arm t hang, and stretch the nerves ver the rib if this is lngstanding. WHAT ARE THE SYMPTOMS? Pressure n the bld vessels can reduce the bld flw t the arm and hand (especially in the elevated psitin) and cause them t tire easily, feel cld, and g pale. Pressure n the vein can cause the arm r hand t swell a bit. Pressure n the nerves can cause vague, aching pains in the shulder, neck, arm and hand. There may be a pain shting all the way dwn t the fingers, and they may g numb. Headaches may ccur. Overhead activities, carrying bjects and driving may be affected. The arm may ften g numb when lying n that side. The hand may feel clumsy and ne may struggle with certain tasks, such as pening a jar, wringing ut a clth and there may be a tendency t drp things.

3 3 HOW IS THE DIAGNOSIS CONFIRMED? Diagnsis is cnfirmed by the typical symptms, physical examinatin (t test clinical signs f artery and nerve cmpressin) and sme tests. Unfrtunately there is n ne special test that can accurately exclude the prblem f T.O.S. That is, a psitive test can cnfirm it, hwever all the tests may be negative, but the patient may still have T.O.S, and may suffer fr a lng time befre the diagnsis has been made. Sme patients may have had neck r shulder surgery befre TOS is diagnsed. In a lt f cases TOS may ultimately be diagnsed by the surgical decmpressin peratin ( pen up and see ). TOS is ften nly diagnsed after excluding ther cnditins that may be present with similar symptms, and these need t be excluded. These are shulder prblems (e.g. rtatr cuff injury), neck prblems (prlapsed disc), ulnar nerve entrapment at the elbw & carpal tunnel entrapment at the wrist. Rarely, a cancerus grwth at the tp f the lung may invade the brachial plexus. (Usually in patients ver 55 years). The fllwing investigatins are rutinely perfrmed: Evaluatin by a shulder surgen t exclude shulder pathlgy, with clinical examinatin, ultrasund and x-rays and pssibly MRI scan f the shulder. X-rays f the cervical spine t assess fr cervical ribs and check the alignment, and if indicated, MRI scan f the neck. Chest X-Ray t check the lung, and lk fr the clavicle and first rib defrmities. Other tests perfrmed, include: Nerve cnductin tests (dne by neurlgists) tgether with neurlgical evaluatin. These may n ccasin be f value, but a negative test des nt mean that TOS is nt present. The test is expensive. Multi-slice CT scan (CT Angigram). This can be perfrmed with the arms at the side and then with the arms elevated abve the head, and can cnfirm dynamic cmpressin f the artery. This may be helpful, but may nt diagnse nerve cmpressin. A vengram (cntrast injected int vein) may n ccasin be useful if it is thught that the vein is bstructed.

4 4 It shuld be stressed hwever that the mst imprtant key t diagnsis remains the exclusin f ther causes f shulder and neck pain alng with a gd histry and clinical examinatin. If symptms are severe and lngstanding and surgery is being cnsidered, then further tests may be included (but may still nt prve that the patient has TOS). HOW IS THE CONDITION TREATED? Fr mst patients, cnservative (nn surgical) treatment is recmmended. Aviding precipitating factrs such as wrng exercises, and time fr the cnditin t settle, may be all that is needed. Stress avidance, wrk simplificatin and jb site mdificatin are recmmended t avid sustained muscle cntractin and repetitive r verhead wrk that wrsens symptms. Physitherapy t help strengthen the muscles arund the shulder (deltids and rhmbids) s that they are better able t supprt the cllar bne. Ultrasund t the scalene muscles and, smetimes strapping f the shulders may help. Pstural exercises t help yu stand and sit straighter, which lessens the pressure n the nerves and bld vessels. If yu are verweight, lsing sme weight may help. Anti-inflammatry medicatin, such as vltaren r brufen, tgether with rest, may help. If the cnditin settles, remember that a return t the precipitating factrs may cause a recurrence. The cnditin des tend t flare up again, frm time t time, even if the aggravating factrs are avided. Aviding a recurrence: Avid carrying heavy bags ver the shulder, and in particular, d nt ever carry a heavy backpack. (TOS is ften called backpackers shulder, as a heavy weight pushes the cllar bne dwn nt the first rib, narrwing the thracic utlet). Surgical treatment is cnsidered when cnservative measures have failed, and the symptms cntinue t be bad.

5 5 WHAT ARE THE EXACT INDICATIONS FOR SURGICAL TREATMENT? If the cause is due t bny bstructin such as a cervical rib, r fractured first rib r cllarbne with malunin; then surgery will be best as the cnditin is unlikely t get better n its wn. If the cause is presumed t be due t cmpressin by the scalene muscles, r inadequate space between the rib and cllar bne, then surgery is recmmended if there is n imprvement after 3-4 mnths, and the symptms are severe. If the symptms are lngstanding and the patient can tlerate them, then cnservative treatment can be cntinued. Surgical decmpressin may be perfrmed earlier in sprtsmen wh want t get back t their activities earlier. HOW IS SURGERY PERFORMED? A decmpressin is perfrmed. Any cervical ribs are remved. The scalene muscles are divided ff the first rib, and any scar tissue between the muscles, arteries, and nerves is remved. It is better t als remve the first rib, t pen the flr f the thracic utlet and make sure an adequate decmpressin has been perfrmed. The incisin usually just abve the cllar bne, abut 6-8cm lng. Sme surgens perfrm the prcedure thrugh the axilla, r armpit, fr a better csmetic result, and t stay away frm the brachial plexus, thereby aviding the risk f injuring it. We prefer the incisin abve the cllar bne, as we find it easier t dissect any scar tissue ff the brachial plexus. We find it easier t identify the whle brachial plexus this way, and make sure there is n scar arund it higher up. Once the prcedure has been dne, a small drainage catheter is placed int the wund. We usually place an epidural catheter arund the nerves, and give lcal anaesthetic thrugh it fr pst perative pain relief. This is usually left in fr 2 days, and initially may cause the whle arm t g numb fr a few hurs s we warn patients nt t be wrried abut this befre the time. The prcedure takes 1 t 1 1 / 2 hurs t perfrm; patients generally spend tw t three days in hspital and are bked ff wrk fr three t fur weeks t recver. The prcedure is

6 6 perfrmed by cardithracic surgens, vascular surgens, general surgens and smetimes rthpedic surgens. In experienced hands the cmplicatins are virtually nn-existent, but surgens wh ccasinally perfrm the prcedure tend t have mre cmplicatins. It is a prcedure that needs t be meticulusly perfrmed by a surgen wh knws the anatmy well. WHAT ARE THE COMPLICATIONS OF THE OPERATION? Many nerves run thrugh the area, but luckily damage can be avided by meticulus dissectin, and identifying all the nerves befre dividing the muscles. We have nt had any f these prblems, but they have been seen and als described in the literature, s need t be mentined. (The reprted incidence is < 1%): Phrenic nerve injury paralysis f the diaphragm n that side. Lng thracic nerve injury Paralysis f the serratus anterir muscle that pulls the scapula (shulder blade) frwards. Brachial plexus injury this is usually mild and reversible. It is wrthwhile t mentin that mild tractin n the brachial plexus may smetimes cause a bit f numbness f the fingertips fr a few days. Remval f the first rib may result in the pleura (membrane cvering the chest cavity) being pened. This happens very rarely in ur practice, and then it is recgnized during the peratin, and the wund drain is advanced int the chest cavity t prevent a bld cllectin there and t make sure the lung des nt cllapse. It is cmmn t have an area f numbness belw the wund, and this may last fr mnths. HOW SUCCESSFUL IS THE OPERATION? In the literature, the success rate quted is arund 70 t 80 %. In ur experience, 80% have a gd result, 15% shw nly slight imprvement and anther 5% have n imprvement. Abut 5% may have recurrence f their symptms, usually after a year. This is usually due t the in grwth f scar tissue arund the nerves, and anther (minr) explratin t release the scar is usually successful.

7 7 AVOIDING TOS If yu have symptms f TOS avid carrying heavy bags ver yur shulder as this decmpresses the cllarbne and increases pressure n the thracic utlet. Yu culd als d sme simple exercises t keep yur shulder muscles strng. Here are fur that yu can try; d repetitins f each exercise twice daily. 1. Crner stretch: Stand in a crner (abut ne ft away frm the crner) with yur hands at shulder height, ne n each wall. Lean int the crner until yu feel a gentle stretch acrss yur chest. Hld fr 5 secnds. 2. Neck stretch: Put yur left hand n yur head, and yur right hand behind yur back. Pull yur head twards yur left shulder until yu feel a gentle stretch n the right side f yur neck. Hld fr 5 secnds. Switch hand psitins and repeat the exercise in the ppsite directin. 3. Shulder rlls: Shrug yur shulders up, back and then dwn in a circular mtin. 4. Neck retractin: Pull yur head straight back, keeping yur jaw level. Hld fr 5 secnds. 5. Weight Training: Avid bench press, snatches and any exercises that strengthen the pectralis muscles. Rather strengthen back f shulder girdle (deltids, rhmbids) as well as triceps/biceps. As with any exercise prgram, if yu start t hurt STOP! Dr DG Harris CARDIOTHORACIC SURGEON Kuilsriver Hspital Tel: THORACIC OUTLET SYNDROME A SHOULDER SPECIALIST S PERSPECTIVE Dr Je de Beer In the rest f this dcument there are well explained details f the thracic utlet syndrme by Dr Dave Harris, a renwned thracic surgen. As mentined by Dr Harris (see abve) the nerves and vascular structures (arteries and veins) are cmpressed between the fist rib and scalene muscles.

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10 10 Typical patients presenting t the shulder specialist are: 1. Thse with enlarged scalene muscles due t repetitive wrk r sprting activities: swimmers, weight-lifters and thers. Als peple ding lifting f bjects regularly at wrk. 2. Yung peple with drpy shulders and ding repetitive arm mtins: e.g. musicians. 3. Scar tissue frmatin after cllar bne r first rib fractures. 4. Pstural prblems: drpping shulders causing tractin n the brachial plexus r shrt stcky necks with sft tissue cmpressing the thracic utlet. A few f the symptms which wuld make the dctr suspect this cnditin in any patient wuld be: 1. Shulder pain: ften ver the AC jint r biceps area. Nt uncmmnly ver the back f the upper arm. 2. A cntinuus burning, lame feeling in the shulder and dwn the arm. 3. Tingling (pins and needles) may be felt dwn the arm and int the hand and ften particularly int the little and ring fingers. There may be lss f cntrl f the hand with drpping bjects. 4. The pain is ften present at rest eg. when driving r simply sitting watching TV etc. 5. The pain may radiate int the neck, the trapezius muscles, the shulder blade (with a burning character), jaw, the head and even chest area. 6. Tractin dwnwards n the arm eg. when carrying shpping bags may aggravate the sensatin dwn the shulder and arm. 7. Pain and discmfrt is ften present fllwing activities and nt nly during the activities eg. after swimming, thrwing, etc. 8. Overhead activities as ding ne s hair, hanging up washing, etc., may cause a feeling f fatigue and burning in the arm, having t bring the arm dwn because the verhead psitin cannt be sustained. Many f these patients present t a shulder surgen after having had varius shulder peratins fr errneus indicatins like impingement, subtle instability, etc. The message is that the surgen and therapist must be wary nt t miss this diagnsis befre deciding n treatment.