Chit Plastica (1981 ) 6 : 75-80 Chiru.rgia plastica ~?; Springer-Verlag 1981

Latissimus Dorsi Musculocutaneous Flap with Trilobed Skin Island for Breast Reconstruction

A Preliminary Report

P. Svedman Department of Plastic and Reconstructive Surgery, University of Lund, General Hospital, S-214 01 Malm6, Sweden

Summary. The latissimus dorsi muscu locu taneous flap provides generous amoun t s of skin and muscle for reconst ruct ion of a breast after mastectomy. Correct analysis of the lack of tissue is necessary to enable a good reconstruc- t ion with regard to posi t ion and shape. Insufficient skin with undue soft tissue tension over a prosthesis is one cause for a less- than-opt imal result. A latissimus dorsi muscu locu taneous flap with a t r i lobed skin is land gives the reconstructed breast a na tu ra l appearance without undue tension.

Key words: Muscu locu taneous island flap Latissimus dorsi - Breast recon- s truct ion - Breast cancer

The in t roduc t ion of the latissimus dorsi muscu locu taneous flap [1, 3, 4] repre- sents an impor t an t improvement in breast reconstruct ion. With this flap missing skin and muscle can be replaced and adequate prothesis cover provided. An ellipsoid skin island is c o m m o n l y used to replace the missing skin. At times a less- than-opt imal result indicates that there may still be unsolved problems with this procedure.

In this paper the skin defect fol lowing mastec tomy is evaluated. Based on this evaluat ion a latissimus dorsi muscu locu taneous flap with a tr i lobed skin island is designed. Case examples are reported.

Methods

To v&ualize the stretching of the skin over the introduced prosthesis, and thus to show where skin should be added if insufficient, the following method was used. A thin rubber film with a grid pattern was placed on a wooden plate with an extension corresponding to that of the breast on the thorax. The rubber film, unstretched with square grids, was fixed to the circumference of the plate. Under the rubber film a breast prosthesis was positioned (Fig. 1). Tension was distributed both transversely (increased distance between the cranio-caudal lines) and cranio-caudally (increased distance between the transverse lines) and was more marked on the lower than on the upper part of the prosthesis. If, in the corresponding clinical situation, insufficient skin is added to the part of the breast flattening of the underlying part of the prosthesis as well as upwards displacement may follow.

0340-5664/81/0006/0075/$131.20

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Fig. 1. Model for visualization of the stretching of the skin over an introduced prosthesis. Increased distance between the lines indicates increased tension in the rubber film draping the prosthesis (a caudal, b cranial)

Fig. 2a-c. Paper models for visualization of the size and shape of the skin defect, a Approximation of a half-sphere shape ; defect with four lobes, b, c Approximation of breast shape: trilobed defects

The importance of adding skin to the lower part of the breast is enhanced by the fact that max imum tension and thinness of skin are usually found low on the chest.

To visualize the shape and size of the skin deject the following paper models can be used. Figure 2a shows how an approximation of a half-sphere shape is obtained by folding of equal paper triangles, leaving a central defect with four lobes. The shape of the breast differs from that of the half-sphere in that its convexity is most pronounced caudally and tis circumference is ellipsoid and narrowest cranially. This asymmetrical shape can in part be reproduced by decreasing the size of one of the four triangular lobes. The models in Fig. 2b and c have shapes that more

Latissimus Dorsi Musculocutaneous Flap for Breast Reconstruction 77

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Fig. 3a-e. Case 1. a Preoperative condition. b Plan for operation c Postoperative result

closely correspond to that of the normal breast. Shaping has been facilitated by making multiple cuts to the breast circumference from the approximate position of the areola as projected on the paper. The major defects are trilobed with their longest axis placed either transversely (Fig. 2b) or obliquely (Fig. 2c) on the chest. Which one of these defects to recreate in the clinical situation is determined either from scar position or from absence or presence of excessive skin tightness of the upper part of the chest.

The approximate size of the skin defect can be determined after applying a paper cut as described either onto the contralateral breast or onto a suitable prosthesis.

Operation

The Latissimus Dorsi Musculocutaneous Flap with Trilobed Skin Island

The skin island is placed either on the anterolateral or on the dorsal part of the latissimus dorsi muscle. A peripheral brim of deep subcutaneous tissue

78 P. Svedman

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Fig. 4a-c , Case 2. a Preoperative condition, b Plan for operation, e Postoperative result

is included in the flap as is sufficient muscle to cover the prosthesis without tension. The mastectomy scar is usually excised and incisions are made to accomodate the trilobed flap. Incisions directed towards the intended sub- mammary fold are carried slightly beyond it. Mobilization of soft tissue is made corresponding to the intended extension of the breast on the chest and is avoided lateral to the lower lateral quadrant. The incisions allow ample access for suture of the latissmus muscle. The skin defect is closed by the trilobed flap after insertion of the prosthesis. The donor defect is closed directly.

Case 1

A 45-year-old patient with a low transverse scar after mastectomy is shown in Fig. 3 a. The angle (W) of the caudal lobe (Fig. 3b) relates to the degree of ptosis of the reconstructed breast. The result 5 months postoperatively is shown in Fig. 3c.

Case 2

A 57-year-old patient with a high transverse scar after mastectomy is shown in Fig. 4a. The longest transverse distance (A) of the breast (Fig. 4b) crosses the planned areolar region and the caudal lobe of the flap is consequently of maximal width at this level. The distance (B) of the flap matches the breast convexity. The result 6 months postoperatively is shown in Fig. 4c.

Latissimus Dorsi Musculocutaneous Flap for Breast Reconstruction 79

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Fig. 5a-e. Case 3. a Preoperative condition. b Plan for operation, c Postoperative result

Case 3

A 42-year-old patient with an oblique scar after mastectomy is shown in Fig. 5a, the plan for the operation in Fig. 5b and the result 3 months postoperatively in Fig. 5c,

A trilobed island provided more generous addition of skin over the lower part of the prosthesis and fitted the defect with no need for excessive mobilization of soft tissue. The flap draped over the prosthesis yielding a natural appearance. There was no flatness of the lower part of the breast and neither cranial nor lateral displacement of the prosthesis.

80 P. Svedman

Discussion

Use of latissimus dorsi musculocutaneous flap for breast reconstruction is indi- cated after radical mastectomy when there is tight skin with or without radioder- matitis. The risk that the reconstruction can delay or prevent detection of cancer recurrence must be taken into consideration when selecting patients for this procedure.

Problems related to the position, shape and size of the reconstructed breast have been documented [2]. It is important to avoid placing the reconstructed breast too high. The patient's wish with regard to breast size should be respected if possible and prosthesis size relates necessarily to the size of the flap.

The lack of skin may be estimated preoperatively with the use of the described paper model. The trilobed skin defect is recreated either with its longest axis placed transversely or obliquely on the chest. The corresponding flap adds skin mostly to the lower part of the breast. The underlying prosthesis rests in a pocket without undue tension and flattening (with or without displacement) can thus be avoided. The subcutaneous rim adds bulk to the usually thin chest skin surrounding the island and smooths the breast's contour. It may also allow inclusion of extra transfascial vessels. T-closure of the three-lobed skin defect on the back is simple since tension is advantageously distributed in two directions.

In the first few cases operated according to this technique there were the following complications: In one patient, where the thoracodorsal artery had been ligated at the previous ablative surgery, the flap during operation became pronouncedly cyanotic and was returned to the donor site. While cyanosis persisted for some days there was no necrosis. In another patient there was a one cm wide necrosis in the skin of the tip of the medial lobe of the flap. After excision and resuture healing was uneventful. Because of this experience the flap is raised only when the thoracodorsal artery is intact and narrow flap tips are avoided.

References

I. Bostwick I, Nahai F, Wallace JG, Vasconez LO (1979) Sixty latissimus dorsi flaps. Plast Reconstr Surg 63 : 3 l

2. Guthrie RH Jr, Cucin RL Jr (1980) Breast reconstruction after mastectomy: Problems in position, size and shape. Plast Reconstr Surg 65:595

3. Miihlbauer W, Olbrisch R (1977) The latissimus dorsi myo-cutaneous ['lap for breast reconstruc- tion. Chir Plastica 4:27

4. Schneider W, Hill HL Jr, Brown RG (1977) Latissimus dorsi myocutaneous flap for breast reconstruction. Br J Plast Surg 30:277

Received July 7, 1981