Vascular thoracic outlet syndrome staging and treatment

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Acta Neurochir (2005) [Suppl] 92: 29–31 6 Springer-Verlag 2005

Printed in Austria

Vascular thoracic outlet syndrome staging and treatment

A. Busetto, P. Fontana, A. Zaccaria, R. Cappelli, and V. Pagan

Thoracic Surgery Unit, Umberto I

General Hospital, Venezia-Mestre, Italy

Summary

Thoracic Outlet Syndrome (TOS) is a well known lesion. Sophis- ticated imaging techniques can clearly highlight any anatomical damage and a wide range of therapeutic choices are available.

It would seem obvious that any given patient should obtain the same treatment irrespective of the medical institution he contacts, but this is not the case. Instead each specialist may recommend dif- ferent treatments: physiatrist, neurologist, surgeons (thoracic, vas- cular, neuro, orthopedic). Everyone preserves his speciﬁc language and there is no univocal treatment plan consensus for this complex syndrome. Evidently, the correct staging of TOS is still an unresolved question.

In order to solve this problem, we collected all clinical and instru- mental aspects of the syndrome into a clear, precise classiﬁcation.

Similar to TNM staging of malignant diseases, we used a grouping model based on the three mainly involved anatomical structures: N ( ¼ Nerves; brachial plexus and sympathetic ﬁbers), A (¼ Artery;

subclavian-axillary), V ( ¼ Vein; subclavian-axillary). We named it the NAV staging of TOS.

A retrospective examination of our case records conﬁrmed a valid and useful correlation between the proposed NAV staging and the therapeutic procedures that were actually applied. It is now essential to perform a multi-centre study to extend the validity of our staging.

Keywords: Thoracic outlet syndrome; ﬁrst rib.

Introduction

Today most has been analyzed and written about TOS and no unresolved questions seem to exist re- garding its etiology, pathology or therapy. Neverthe- less, TOS remains a complex syndrome and di¤erent specialists are supposed to work together to achieve the best treatment.

Therefore an emerging problem is to ﬁnd a uni- versal language, comprehensible to every physician.

We classiﬁed all TOS cases treated by us in the past by grouping clinical and instrumental data according to their anatomical pertinence, so that any given case was depicted by the status of three parameters: N, A, V (as

listed below). For any parameter, four grades of in- volvement were deﬁned.

Staging system

Nerves (brachial plexus, sympathetic ﬁbres) ) N

0

. No symptoms or signs of injury.

) N

1

. Only mild sensitive symptoms: non-invalid- ating paresthesia or pain; no electrical ab- normalities (negative EMG, nerve conduction velocity and SEP’s recordings).

) N

2

. Severe sensitive symptoms: invalidating pain or sympathetic irritation; mild electrical abnormalities (sensitive conduction velocity loss).

) N

3

. Motor symptoms: weakness even with muscu- lar atrophy; serious electrical abnormalities (sensitive and motor conduction velocity loss).

Subclavian-axillary artery

) A

0

. No symptoms or signs of injury.

) A

1

. Intermittent compression: irregular appear- ance of arm ‘‘claudicatio’’ symptoms; no ana- tomical local lesions.

– Documented by ultrasound imaging (Dop- pler and plethysmography).

) A

2

. Minimal anatomical local lesions: minimal stenosis with mild post-stenotic dilatation (less than twice the size of normal arterial diameter).

– Ultrasound can only suspect the anatomical damage.

– Conﬁrmation requires spiral CT or MRI

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arteriography (traditional arteriography is reserved to particular questions).

) A

3

. Severe anatomical local lesions: intimal dam- age with aneurysmal evolution (post-stenotic dilatation more than twice the size of normal arterial diameter) G mural thrombosis; pos- sible distal vascular damage (brachial or cere- bral embolization).

– A detailed investigation is possible with tra- ditional arteriography only.

Subclavian-axillary vein

) V

0

. No symptoms or signs of injury.

) V

1

. Chronic intermittent compression: irregular appearance of arm swelling without any sign of acute or chronic thrombosis.

– Documented by ultrasound imaging.

) V

2

. More advanced disease not amenable to sur- gical revascularization: chronic thrombosis (diagnosed more than 2 weeks after onset) with long segment of vein obstructed (more than 20 mm).

– Conﬁrmed by venography.

) V

3

. More advanced disease with predictable sur- gical revascularization: chronic thrombosis with short segment of vein obstructed (less than 10 mm); acute (diagnosed within 5 days) or sub-acute (between 6 days and 2 weeks) thrombosis.

– Conﬁrmed by venography.

Taking into account the degree of involvement of each of the above parameters, the patient’s clinical state is classiﬁed into one of the following four stages.

As stage increases, therapy becomes gradually more complex: ﬁrst conservative, than mild surgery and, ﬁ- nally, heavy surgery.

Stage I: N

01

A

01

V

01

. Intermittent neuro- vascular compression.

– Only conservative treatment is indicated: physio- kinesitherapy (FKT).

Stage II: N

2

A

₀₁

V

₀₁

. Early neurological involve- ment (invalidating sensitive symptoms) without irre- versible anatomic damage.

– FKT.

– When ine¤ective, 10–30%, mild surgery becomes necessary: simple thoracic outlet decompression (scalenectomy, ﬁrst rib resection, subclavian artery

adventitiectomy, complementary maneuvers when particular osteo-muscular anomalies are present).

Stage III: N

3

or A

2

or V

2

. Advanced neurological involvement and/or vascular damage that require

‘‘mild’’ surgery.

– FKT is not indicated.

– For N

3

: decompression and possible neurolysis.

– For A

2

or V

2

: decompression G sympathectomy (when coexisting sympathectomy N

₂

) G neurolysis (when coexisting N

3

).

Stage IV: every N with A

₃

or V

₃

. Advanced neurolog- ical involvement and/or vascular damage that require

‘‘heavy’’ surgery.

– FKT is not indicated.

– For A

3

: decompression þ arterial reconstruction (resection-reanastomosis or by-pass) G sympath- ectomy (when coexisting sympathetic N

2

) G neuro- lysis (when coexisting N

₃

) G brachial embolectomy (when coexisting distal brachial embolism) G thrombolysis (when coexisting retrograde cerebral embolism).

– For V

3

: pre-operative pharmacological throm- bolysis; subsequent decompression G venous angio- plasty (if residual obstruction is left) G neurolysis (when coexisting N

₃

).

– The role of percutaneous transluminal angio or venoplasty is still debated in the literature and, therefore, these procedures are not included in our protocol.

Methods and materials

178 patients with TOS where entrusted to our Centre (Thoracic, Neuro and Vascular Surgery Units of Umberto I

General Hospital, Mestre-Venice, Italy), from 1984 to 2003 and they where grouped as follows, according to stages:

Stage I: 67 cases (38%).

Stage II: 77 cases (43%).

Stage III: 24 cases (13%).

Stage IV: 10 cases (6%).

Results

Stage I: FKT for every case with good results in 60%

of patients; the remaining 40% didn’t consult our de- partment for follow-up.

Stage II: FKT for every case with good results in 42%; 36% needed minimal surgery (with subsequent good results); the remaining 22% didn’t consult our department for follow-up.

30 A. Busetto et al.

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Stage III: Minimal surgery for every case with good results in 79%, fair in 13%, poor in 8%.

Stage IV: Heavy surgery for every case with good results.

Conclusion

A precise, synthetic and reproducible staging of TOS, based on the three parameter (TNM-like) grouping model, is still not present in the literature.

Classiﬁcations can be found regarding some particular aspects of the syndrome [2, 3, 5] but a systematic one was only tested by Pang and Ass. [4], with quite a use- less outcome.

Our NAV staging system is a new proposal and a retrospective study (based on our past cases) has re- vealed a good correlation between stages and applied therapy.

Using our parameters everyone can easily depict the actual status of a patient and thus a universal language is at last determined.

It is now important to apply the NAV staging to a su‰cient amount of new TOS cases. Since TOS is quite a rare syndrome, a multi-centre study is needed with the aim to obtain a su‰cient amount of cases.

References

1. Busetto A, Fontana F, Zaccaria A, Cappelli R, Canton A, Ste- vanato G, Pagan V (2004) Sindrome dello stretto toracico supe- riore: stadiazione clinica. Chirurgia Italiana 56 (1): 55–62 2. Mackinnon SE, Dellon AL (1988) Surgery of the peripheral