The lateral thoracic region flap

British Journal ofPlasric Surgery (1990). 43, 162-l 68 0 1990 The Trustees of British Association of Plastic Surgeons

The lateral thoracic region flap S. BHATTACHARYA,

S. P. BHAGIA,

S. K. BHATNAGAR

and R. CHANDRA

Postgraduate Department of Plastic Surgery, King George’s Medical College, Lucknow. India

Summary-The lateral thoracic region flap is based at the level of the 3rd rib on multiple direct cutaneous perforators. It has an excellent vascularity with a dependable length/width radio of 3: 1. The donor area, which lies in a concealed region, can often be closed primarily. The flap is hairless and can be used anteriorly to cover raw areas over breast and axilla and posteriorly over scapula and chest wall. As a distant flap it can be used to resurface raw areas on the ipsilateral upper arm and forearm and contralateral hand. The successful use of the flap in 40 cases in this series confirms its reliability, versatility and convenience.

Anatomy of the flap

The lateral chest wall between the lateral borders of pectoralis major anteriorly and latissismus dorsi posteriorly is richly vascularised by multiple direct cutaneous perforators running inferiorly at the level of the deep fascia. In a study of 18 sides in 9 cadavers, the most constant direct cutaneous perforator which could be identified in all specimens was from the thoracodorsal artery. It originates 24 cm from the origin of the thoracodorsal artery from the subscapular artery and perforates the deep fascia at the level of the 3rd rib. In 7 sides there was more than one perforator from the thoracodorsal artery. The other vessel which was seen in 16 specimens was the lateral thoracic artery but its site of origin was inconstant-from the axillary artery in 9 sides, the subscapular artery in 5 sides and the thoracodorsal artery in 2 sides. In the 2 sides where the lateral thoracic artery was absent it was replaced by an accessory lateral thoracic artery and an extra direct cutaneous branch from the thoracodorsal artery. The third vessel, which was present in 7 sides, was the direct cutaneous branch of the pectoral branch of the acromio-thoracic axis. In the remaining dissections this vessel was replaced by a leash of finer vessels running distal to the pectoralis major and anterior to the lateral thoracic artery. Thus any vertically orientated flap based at the level of the 3rd rib on the lateral chest wall will always include two or three of the following vessels (from behind forward): the thoracodorsal artery, the accessory lateral thoracic artery, the lateral thoracic artery and the pectoral branch of the

acromio-thoracic axis (Figs 1 and 2) (Bhagia and Chandra, 1987). Flap marking and elevation

The anterior incision starts from the 3rd intercostal space along a line dropped vertically downward from the coracoid process, crossing the inferolateral border of the pectoralis major and running over the serratus anterior and external oblique as far as 3 cm below the costal margin. The posterior incision starts from the same level, i.e. 3rd intercostal space, 2 cm medial to the lateral border of latissimus dorsi, and is carried straight downwards crossing its infero-lateral border and extending 3 cm below the costal margin. The anterior and posterior incisions can now be joined by a gentle curve so that the flap extends 4-6 cm below the costal margin in the mid axillary line. The incisions are made, dividing the underlying deep fascia which is stitched to the skin. The flap elevation is started anteriorly and as the inferolateral border of the pectoralis major is reached, an attempt is made to go deep to the muscle by about 1 cm. By doing so, the interconnecting channels of the fasciocutaneous perforators of the pectoral branch of the acromio-thoracic axis are preserved and the lateral thoracic artery also gets safely included in the pedicle of the flap with its vascular arborisation. The flap can then be quickly raised from the distal and posterior sides after ligating the perforators from the intercostal vessels and cutting the lateral cutaneous branches of the intercostal

162

THE LATERAL

THORACIC

Latissimus

Lateral

REGION

163

FLAP

dorsi

thoracic

artery

Fig. 1

Fig. 2 Figure l-Diagrammatic representation of the lateral thoracic region flap and some of the vessels that may supply it. Figure 2Dissection of the axilla revealing the origin of the subscapular trunk (1) from the axillary artery (2). The muscular branch 01. the thoracodorsal artery (3) lying on the undersurface of latissimus dorsi (LD) which has been cut and reflected laterally and the fasciocutaneous perforator (4) originating from the thoracodorsal artery. The lateral thoracic artery (5) is originating from the axillary artery anteriorly.

nerves. From the fourth rib onwards (about 6 cm below the axillary artery), the dissection is done under vision preserving all vascular inputs to the flap. The flap elevation takes about 30 minutes.

Clinical applications __

The lateral thoracic region flap has been used clinically in 40 cases (Table 1). Twenty-two flaps were used for local defects anteriorly, posteriorly or Table 1

Donor defect

The skin over anterior and posterior chest walls can be undermined up to the midline and fasciotomies on either side often make it possible to close the entire donor defect primarily. When that is not possible most of it can be closed primarily, leaving only a small triangular area high up in the axilla, well hidden by the upper arm, which needs grafting. Primary closure of the upper part is avoided in young females to prevent the shift of the breast laterally.

Distant application

Local application Axillary

contracture

14

Exposed above-elbow amputation stump Sarcoma-scapular region CA breast resurfacing CA breast 2-stage reconstruction

C =contralateral:

2 2 3 1

I = ipsilateral

Post-burn contracture 9 dosum of hand (C) Volkmann’s ischaemic 3 contracture (C) Crush injury-hand (C) 1 Osteomyelitis-forearm (I) 1 Osteomyelitis-upper 2 arm (I) 2 On wrist carrier(C)

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Fig. 4

Fig. 3 Figure &(A) The lateral thoracic region flap marked after the release of axillary contracture. (B) The flap elevated and the vascular pedicles (Rc\) entering the flap. (C) The flap is transposed to cover the raw area in the axilla. Note dog-ear left anteriorly (1). Figure &(A) The lateral thoracic region flap used to cover the raw area left after the release of axillary contracture, with excellent colour and texture match. Note primary closure of the donor defect. (B) Result after healing-arm abducted.

in the upper arm, and 16 flaps were used for distant sites in the ipsilateral upper arm and forearm or the contralateral hand. Two flaps were used to resurface the contralateral exposed leg bones by carrying them on the contralateral wrist carrier. The flap can be tailored to cover the defect following the release of an axillary contracture (Fig. 3) and it suits the situation most admirably in terms of colour match, pliability and protective sensation (Fig. 4). Even if the overlying skin is scarred, a flap length/width ratio of 3 : 1 is easily achieved because the vascularity at the level of the fascial plexus is never damaged. Except for a dog-ear high up in the axilla the appearance is of a normal axilla and as there is no fear of secondary contracture, as in a skin grafted axilla, the abduction splint can be removed after 5 days. The above-elbow amputation stumps were short

of skin and a revised amputation of the bone to fit them into the remaining skin cover would have resulted into too short a stump. After a lateral thoracic flap cover, the stump length could be maintained (Fig. 5). The raw areas left behind after a simple mastectomy with axillary clearance in 4 patients with carcinoma of the breast were such that by merely undermining the edges a primary closure could not be achieved. A lateral thoracic region flap of an average 18 x 7 cm dimension was used in each of them to resurface the defect and the donor area was closed primarily (Fig. 6). In one of these patients, a 32-year-old female with a T, No MO tumour, a silicone gel breast prosthesis has been introduced at a second stage after one year of disease-free status. The raw areas in the posterior chest were of a

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FLAP

Fig. 6 Fig. 5 Figure 5-(A) An unhealthy above-elbow amputation stump with skin shortage. (B) The stump covered by lateral thoracic region flap. Figure b(A) Carcinoma of breast in a young female. The lines of tumour excision and the lateral thoracic region flap marked. (B) The flap used to cover the post-mastectomy the flap (J ).

defect and the donor area closed primarily.

diameter of 10 cm and 13 cm over the scapular region after the excision of a fibrosarcoma and chondrosarcoma respectively, and a lateral thoracic region flap was used to cover each of them, leaving a small dog-ear behind the axilla. The 18 flaps which were used as distant flaps were of an average 22 x 8 cm dimension. The narrowest flap, which was used to cover a postsaucerisation defect of the ipsilateral humerus, was 6 cm with a length of 19 cm (Fig. 7). The successful take of this flap in the midst of infection proves beyond doubt the dependable vascularity of the lateral thoracic region flap. All the distant flaps were delayed on the 21st day by dividing the middle two quarters of the pedicle. After a further 7 days the flap was divided by severing the anterior and posterior quarters of the pedicle. In post-burn contractures of the hand, after release and MP capsulotomies, the hand was put into a functional position by passing pins across the MP and IP joints, and on the raw area of the dorsum the lateral thoracic region flap was used as cover. In the second stage, at the time of flap division, the adduction contracture of the thumb was released and the flap pedicle was used to cover this raw area. A mitten hand was thus formed, with 4 fingers under one flap which were isolated in subsequent stages under local anaesthesia (Bhattacharya et al., 1988). The patients with Volkmann’s ischaemic contracture had soft tissue deficits at the wrist and the

Note the terminal

necrosis

at the tip of

first web-space. The lateral thoracic region flap was used to cover the released first web-space and its pedicle, after flap division was used to resurface the volar aspect of the wrist (Fig. 8). During the subsequent stages a sublimis to profundus tendon transfer was also done. The flap was used once successfully to resurface the dorsum of a crushed hand which had slipped inside a wheat-thresher (Fig. 9). The elevated position of the hand while the gap was attached prevented undue oedema of the hand and fingers and, after pedicle division and subsequent tendon surgery, functions were restored and the patient is now back to his original vocation. Results

The functional results of the use of the lateral thoracic region flap as a local flap have been most encouraging and except for marginal necrosis in one (Fig. 6B), out of a total of 22 flaps there have been no other complications. This necrosis was attributed to too much tension in the flap while covering the raw area of a modified Patey’s mastectomy. All the distant flaps healed satisfactorily except for three. In one of them the distal 1 cm edge was lost because of infection following haematoma formation. In all subsequent cases we used a drain under the flap to avoid this complication. The two remaining complications were encountered in those flaps which were taken on a

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C Fig. I Figure 7-(A) Post-saucerisation defect in osteomyelitis of humerus. A narrower flap than the one marked was elevated (6 x 19 cm). (B) Flap elevated. Lower half of the donor area closed primarily while upper triangular defect skin grafted. (C) Flap applied to the defect. (D) Flap divided and wound healed.

Fig. 8

Fig. 9

Figure &(A) Volkmann’s ischaemic contracture of right hand-adduction contracture of 1st web was released in stage one and a lateral thoracic region flap used to cover the first web-space. Volar contracture of wrist partly released subsequently and the divided pedicle of the flap used to resurface it. (B) Wrist release completed and pedicle of flap inset. Figure %Crush injury of hand. After reduction and immobilisation of the various small bone fractures, the dorsum is covered by a lateral thoracic region flap.

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REGION

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FLAP

contralateral wrist carrier. These were 9 x 24 cm flaps and were delayed on day 21 and divided on day 28, but by day 30 a clear line of demarcation appeared and 8 and 10 cm of the distal part of the two flaps were lost. This suggests that once the pedicle has been divided the advantages of the fasciocutaneous nature of the flap with 3 : 1 length/ width ratio are lost and, with a 9 cm wrist attachment, only 14-16 cm of the flap could be viably supported. The scar of primary closure of the donor defect hypertrophied in 6 cases but as it was in a concealed area the patients were not bothered by it.

Discussion

The lateral thoracic region flap is versatile and reliable, with both local and distant applications. For all local resurfacing it presents an excellent colour and texture match and protective sensation develops in the course of time. It is non-hairy in the most hairy individuals. The donor area can either be closed primarily or a small triangular area below the hollow of the axilla needs skin grafting. In either situation the donor area scar lies hidden by the upper arm. The designing of the flap and its elevation are quick and simple. When used as a distant flap to resurface released contractures of the hand, the latter is kept elevated in a comfortable position across the chest. This position, besides being easy for the patient, allows easy nursing and keeps the injured hand elevated, thus avoiding oedema. This is in contradistinction to the application of groin (McGregor and Jackson, 1968), SEPA (Dias et al., 1987) or lower abdominal skin flaps (Stranc and Sanders, 1968) which keep the hand in a dependent position, thus encouraging oedema (Bhattacharya et al., 1988). As a tube pedicle flap it can be taken on a wrist carrier on the radial or ulnar side in one stage without resorting to bipedicle tube construction. On a wrist carrier, however, flaps with a 3 : 1 lengthto-breadth ratio have failed twice and we advise a wide attachment at the wrist and a 2: 1 flap only. When a very long skin tube is required the lateral thoracic territory can be combined with the territory of the groin flap to construct a tube with ends near the axilla and groin (Webster, 1937). A similar fasciocutaneous flap from the lateral chest wall, the subaxillary pedicled flap, was designed and standardised by the authors (Bhattacharya et al., 1988; Chandra et al., 1988) but that

was based on one direct cutaneous vessel-the branch of the subscapular-thoracodorsal axis. The lateral thoracic region flap is harvested from the same site but it is a larger flap based on multiple direct cutaneous vessels and therefore much more reliable than the former one. The variations and controversies in the vascular anatomy of this region were explored by Taylor and Daniel (1975), Harii et al. (1978), Freeman et al. (1981) and Rowsell et al. (1984). The dynamic territory of the lateral thoracic artery was shown by Nakajima et a/. (1981). With the present state of our knowledge about the fasciocutaneous vasculature of this region, it is worthwhile going back to the experimental laboratory and to do perfusion studies in fresh cadavers to determine the ability of the deep fascia and subcutaneous tissue alone to support the skin in this region. Island flaps seem to be a definite possibility. References Bhagia, S. P. and Chandra, R. (1987). Lateral thoracic fasciocutaneous flap. Transactions of IX International Congress oj Plastic and Reconstructire Surgery. New Delhi : Tata McGraw Hill Publishing Co. Bhattacharya, S., Pandy, S. D., Chandra, R. and Bhatnagar, S. K. (1988). Lateral chest wall fasciocutaneous flaps in the management of bum contractures on the dorsum of the hand. European Journal of Plastic Surgery. 11, 8. Chandra, R., Kumar, P. and Ahdi, S. H. M. (1988). The subaxillary pedicled flap. British JournalqfPlastic Surgery. 41, 169. Dias, A. D., Thatte, R. L., Pat& U. A., Dhami, L. D. and Prasad, S. (1987). The uses of the SEPA flan in the renair of defects in the hands and fingers. British Journal of P&tic Surgery, 40. 348. Freeman, J. L., Walker, E. P., Wilson, J. S. P. and Shaw, H. J. (1981). The vascular anatomy of the pectoralis major myocutaneous flap. British Journal of Plastic Surgery. 34, 3. Harii, K., Torii, S. and Sekiguchi, J. (1978). The free lateral thoracic flap. Plastic and Reconstructive Surgery, 62, 212. McGregor, I. A. and Jackson, I. T. (1968). The groin flap. British Journal of Plastic Surgery, 25. 3. Nakajima,H.,Maruyama, Y. andKoda, E. (1981). Thedefinition of vascular skin territories with prostaglandin El-the anterior chest. abdomen and thigh-inguinal region. British Journalof Plasiic Surgery. 34.258. Rowsell, A. R., Eisenherg, N., Davies, D. M. and Taylor, G. I. (1984). The anatomyof the subscapular-thoracodorsal arterial system: study of 100 cadaver dissections. British Journal of Plastic Surgery, 37. 574. Stranc, M. F. andsanders, R. (1968). Abdominal wall skin flaps. In Grabb, W. C. and Myers. B. (Eds) Skin Flaps. Boston: Little, Brown and Co.

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Taylor, G. I. and Daniel, R. K. (1975). The anatomy of several free flap donor sites. Plastic and Reconstructive Surgery, 56, 243. Webster, J. P. (1937). Thoraco-epigastric tubed pedicles. Surgical Clinicsof North America. 17, 145.

Department Lucknow.

of Plastic Surgery,

and Head of Department King George’s

Requests for reprints to: Dr S. Bhattacharya, Lucknow 226 006, India.

The Authors S. Bhattacharya, MS, MCh(Plast), Pool Officer S. P. Bhagia, MS, formerly

S. K. Bhatnagar, MS, Reader R. Chandra, MS, MS, Professor

OF PLASTIC SURGERY

Chief Resident

Paper received 21 February 1989. Accepted 29 May 1989 after revision.

Medical College,

C-907 Mahanagar,