Free groin skin flaps

British Journal of Plastic Surgery (1975), 28 225437

FREE GROIN SKIN FLAPS

By KIYONORI HARII, M.D., KITARO OHMORI, M.D., SHUHEI, TORII, M.D., FUJIYA MURAKAMI, M.D., YOSHIHIKO I&AI, M.D., JUNSUKE SEKIGUCHI, M.D., and SEIICHI OHMORI, M.D.

Department of Plastic and Reconstructive Surgery, Tokyo Metropolitan Police Hospital, 2-10-41, Fujimi, Chiyoda-Ku, Tokyo, Japan

SINCE the successful clinical transfer of a free scalp flap by Harii in 1972, and of other free flaps by Daniel and Taylor (Ig73), O’Brien et al. (1973, 1974) and ourselves (Harii et al., Ig74a, b), the transfer of flap by microvascular anastomosis is now recognised as having many advantages over conventional pedicle flaps.

In the present series of 47 groin flaps the anastomoses were all carried out by one surgeon (K. H.).

OPERATIVE TECHNIQUE

The operation takes on average 5-6 hours and as we described for free deltopectoral flaps, 2 operating teams are preferable.

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FIG. I. The blood vessels of the groin region.

Reprint requests to Kiyonori Harii, M.D.

225

226 BRITISH JOURNAL OF PLASTIC SURGERY

Preparation of the recipient site. The recipient site is prepared exactly as for an ordinary pedicle flap except that suitable recipient vessels must be identified and exposed. These should be other than the small arteries and veins which lie superficially in the subcutaneous layer. In the face, adequately sized vessels such as the facial artery and vein or the superficial temporal artery and vein are readily available. In the extre- mities, by contrast, only a few vessels are available which meet the requirement of peripheral circulation and are of adequate size, so that end-to-side anastomosis may occasionally become necessary; our experience, however, is that blood flow can usually be best secured by end-to-end anastomosis. On the trunk, intra-abdominal vessels may sometimes be transposed to the subdermal layer as recipients as in Case 3.

The recipient vessels chosen are clamped with Heifetz’s neurosurgical clips and then severed. Clamping should be immediately followed by transplantation of the flap, since excessively prolonged clamping may damage the intima, leading to thrombogenesis.

Design and elevation of the groin flap. Our free groin flap differs from the pedicle groin flap of McGregor and Jackson (1972) in that it is not exclusively supplied by the superficial branch of the superficial circumflex iliac artery which enters the subcutaneous layer at the medial border of the sartorius muscle. Instead, it involves a donor area extending medially to the line of the femoral artery which is usually nourished by both the superficial circumflex iliac artery (SCIA) and the superficial epigastric artery (SEA) which ascends from the femoral artery through the cribriform fascia, running in front of the inguinal ligament toward the lower abdominal wall (Fig. I).

The variations in the arteries supplying the flap will be considered more fully in a later paper but the patterns found in this series are summarised in Figure 2. Our

clinical experience shows that either of the 2 arteries, each forming a close network in the subcutaneous tissue (Fig. 3) is enough to supply these areas. Because there are no

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3 147

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FIG. 2.

FREE GROIN SKIN FLAPS 227

available means by which to assess the blood flow provided by each, we use the artery of larger outer diameter as the easier to anastomose.

Veins draining the donor area consist of a superficial one often seen through the skin and a more deep-seated pair of venae comitantes, each closely accompanying the arteries. Being often as small as I mm or less in outer diameter, one vena comitans alone cannot provide adequate drainage. The superficial circumflex iliac vein (SCIV) lying in the subcutaneous layer often joins with the superficial epigastric vein at the saphenous opening and drains into the saphenous bulb as a common trunk, the superficial axial vein. This trunk is so large, having an outer diameter of 13-23 mm, that it provides adequate drainage. In some cases, the 2 veins may have separate origins, in which event they should be anastomosed with the recipient veins.

The size and shape of the groin flap is determined in the same way as for a full- thickness skin graft: by exact measurement of the recipient site. The medial border lies just over the femoral artery and the central axis of the flap lies along a line which connects a point on the artery about 2.5 cm below the inguinal ligament with the anterior superior iliac spine (Fig. 4). Elevation begins at the lateral margin, proceeding medially beneath Scarpa’s fascia. After the iliac spine is passed, the SCIA can be seen to enter the subdermal layer, through the fascia somewhat medial to the spine. As the flap is further raised, it is ascertained that the artery is included with the fascia in the flap by making a longitudinal incision through the fascia at the lateral border of the sartorius muscle. Here, the lateral femoral cutaneous nerve is often found crossing the artery and it is best preserved in order to minimise the area of lost sensation in the thigh. The few muscular branches that may be present are ligated. On reaching the region lateral to the femoral artery, pulsation of the main trunk of the SCIA can often be perceived in the flap. As separation proceeds without damaging the trunk, the site of its origin from the femoral artery can be found. This site serves as a point of reference in searching for the SEA which will be found lying medial to the femoral artery. The SCIA and SEA each are accompanied by a pair of venae comitantes which are meanwhile preserved. The superficial axial vein (SAV) or its equivalent is now sought by blunt dissection in the subcutaneous tissue at the medial end of the flap. When the artery and vein(s) most suitable for anastomoses have been selected, they are clamped with Heifetz’s neurosurgical clips and severed. The other arteries and veins are ligated.

Microvascular anastomoses. Before beginning the anastomoses, the cut ends of the vessels are thoroughly washed with heparinised saline (20 IU ml saline) to remove blood clots; perfusion of the flap as a whole is not necessary. It is convenient to anastomose the vessels under an operating microscope at some 5-15 times magnification. End-to-end anastomosis between the donor and recipient vessels is our ordinary method, the details of which are described elsewhere.

The suture used is IO/O monofilament nylon (Crown) with a 3/g circle, IOO p

atraumatic needle which is adequate for anastomosis of any vessels 0.8 mm or more in diameter. Anastomosis may begin with either the arteries or the veins, but when restoring blood flow the vein is unclamped first. Blood often leaks from the arterial anastomosis when the vessels are unclamped but this can be controlled in about 5 minutes if they have been wrapped in a thin rubber pressure-sheet. With satisfactory anastomosis, vigorous dermal bleeding from the distal edge of the flap will be noticed immediately after restoration of blood flow. Marked oozing of dark blood from the venous anastomosis will also take place. After monitoring the condition of the flap for some 5-10 minutes, the rubber sheeting covering the arterial anastomosis is removed and suturing of the edges of the flap begun. By then, bleeding from the anastomoses will usually be almost controlled; continuing bleeding indicates improper technique. Closure of the recipient site is simple because of the lack of pedicles. For a donor site IO cm


FIG. 3. A close vascular network in a thin groin flap.

FIG. 4. The design of the groin flap. A, shows femoral artery, B, inguinal ligament ?nd C, the anterior superior iliac spine. The line drawn between the points D and C is the centre hne of the flap.


or so in width, suture approximation is facilitated by undermining widely the skin around the defect. If direct closure is impossible, a split thickness skin graft is indicated.

Interruption of blood flow in the flap lasts less than go minutes. It is our routine practice to administer no systemic heparin postoperatively but only 1,000 ml per day of low-molecular Dextran to adults.

CLINICAL EXPERIENCE

Free groin flaps have been successfully transplanted to various parts of the body instead of the conventional pedicled skin flaps. The following are representative cases:

Case I. The left foot of a 36-year-old male was crushed. During the next 2 years, osteomyelitis developed in the fractured 2nd and 3rd metatarsal bones. These were resected and a split-thickness skin graft applied to cover the defect. When admitted to our unit, he complained that the dorsally dislocated 2nd and 3rd toes were so painful he could not walk properly (Fig. 5).

All scar tissue on the affected foot was excised and the dislocated toes repaired by fixation with a block of iliac bone graft taken from the same side after elevation of the donor flap.

The skin defect was covered with a 14 x 8 cm free groin flap. The flap was nourished by the SCIA with a diameter of 1.2 mm, while a SEA could not be found on the femoral artery.

FIG. 5. Case I. A and B, A crushed left foot resulted in dislocation of the 2nd and 3rd toes and a defect of the metatarsal bones.


FIG. 6. Case I. A, All scars were excised and iliac bone was grafted into the metatarsal bone defect arrowed. B, The raised groin flap. C, The flap immediately after revascularisation.

FIG. 7. Case I. Arteriogram shows good patency of the anastomosis I month postoperatively.


The donor vein was the SAV with a diameter of 2.0 mm. The artery was anastomosed to the dorsalis pedis artery whose diameter was about 3.5 mm and the vein to the great saphenous vein whose diameter was about 2.0 mm by the end-to-end method (Fig. 6).

About I month later the flap took well and the arteriogram showed good patency of the anastomosis (Fig. 7).

Six months later the grafted bone had not been absorbed and the flap was stable when he began to walk (Fig. 8).

Case 2. A zz-year-old male suffered from old burn scars and contracture of his chin-neck region. At first, all scar tissue on the neck region was excised and the contracted anterior cervical muscles were incised to create a natural chin-neck angle (Fig. 9).

When dissecting the recipient site, the left facial artery (1.5 mm in diameter) and vein (2.0 mm in diameter) were exposed and carefully preserved as recipient vessels.

In the 20 x 15 cm free groin flap the SCIA and the SEA had a common trunk of origin from the femoral artery, the external diameter being about 1.8 mm; the SAV with a diameter of 2.0 mm was used for drainage (Fig. IO).

This flap took perfectly and 5 months later the functional and cosmetic features of the neck were satisfactory (Fig. II).

Six months after the initial operation a free groin flap from the other side was transferred to the chin region using the right facial artery and vein as recipients. In this second flap, the SCIA and the SEA arose separately and the former was used for the donor artery because of its bigger size.

The second free groin flap also took well and onlay bone grafting beneath the flap is planned (Fig. 12).

Case 3. A 32-year-old woman underwent radical mastectomy for cancer. As the wound had been closed under tight tension there was repeated unstable ulceration along the suture line during the following 3 years. There were no signs of recurrence of the cancer and the patient desired cosmetic treatment. We therefore planned a free groin flap to cover the defect.

FIG. 8. Case I. A, The flap 6 months later and B, the consolidated bone graft.


FIG. g. Case 2. A and B, Burn contracture of the neck with underdevelopment of the chin.

FIG. IO. Case 2. A, The flap raised and B, transplanted.


FIG. II. Case 2. A and B, 6 months later; there is no recurrence of the contracture and good extension of the neck.

FIG. 12. Case 2. A, The result 8 months after the initial surgery. The second free groin flap to the chin has also taken well. B, The donor sites of the flaps. The larger one was covered with split thickness

skin grafts, but the smaller could be closed by direct approximation.


FIG.

ve:

13. Case 3. A, Large defect after radical mastectomy. brought from the abdominal cavity.

The gastroepiploic vascular pedicle

ssels (arrowed). B, The gastroepiploic artery and vein selected as the recir

C, The isolated bulky groin flap. D, The transferred flap about 6 months late

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:r.


FIG. 14. Case 4. A, Contracture of the right hand. B, All scar tissue in the palmar area was excised and the adduction contracture of the first web space released. C, The free groin flap sutured into the

defect. D and E, The flap 5 months later.


After complete excision of the unstable scar and release of the tension, a large skin defect with exposed bone resulted. Suitable recipient vessels could not be found around the defect and so the right gastro-epiploic vessels were brought through the abdominal wall. The diameter of the artery was 14 mm and that of the vein 2.0 mm and the 14 x IO cm free groin flap was completely nourished. The artery in the flap which was anastomosed was the SEA and the vein the SAV (Fig. 13).

Case 4. A z5-year-old male involved in a factory accident had the palmar skin and fingers of his right hand avulsed. When he was later transferred to us, only the contracted index finger and the thumb remained and there was an adduction contracture of the first web space.

All the scars were excised, the contracture of the first web space released, and the recipient ulnar artery, which had been severed by the accident, and a cutaneous vein were exposed.

A 20 x g cm free groin flap was raised. The SCIA and the SEA were of equal size and the former was selected as the donor artery (Fig. 14).

The donor site was easily closed by direct approximation.

RESULTS

Of the 47 free groin flaps, IO showed some degree of necrosis; of those complete necrosis occurred in 5, superficial necrosis in 2 and partial necrosis in 3.

Two of 5 complete necroses were due to mistakes in flap elevation; one involved injury to the nutrient artery and the other was due to a mistake in the design. Another 2

of the 5 were due to late thromboses of the anastomosed arteries which were affected by long-standing inflammation and degenerate. The last involved rupture of the anastomoses established with recipient vessels prepared in an area with a deep radiation ulcer. It is therefore advisable in such a case to transpose healthy recipient vessels from an intact area.

The 2 superficial necroses also exhibited degenerative changes in recipient vessels due to deep chemical burns and Raynaud’s disease. They underwent gradual necrosis for about 3 weeks, but their fatty tissue took so well that they were later covered with split thickness skin grafts.

Two of the 3 partial necroses were due to poor venous drainage: in I of the 2 cases

a split thickness skin graft was later applied to the necrosed area while the other healed spontaneously. In the last case, poor arterial supply at the recipient site appeared the cause of partial necrosis of the distal third of the flap (the size of this flap was 17 x 14 cm).

DISCUSSION

The advantages of free flap transfer by direct vascular anastomosis are obvious. The specific advantages of the free groin flap are:

Large size of graft available; our largest measured 28 x 18 cm;

Direct closure of donor defect in many cases;

Scar situated in a usually hidden area;

Reliability of blood vessels.

A specific disadvantage is that all of the subcutaneous tissue must be included in

the flap; in the case of an obese patient this could make the operation impossible. In

certain individuals in certain ethnic groups the groin area is much hairier than in the

average Japanese and this might limit the use of groin flaps particularly around the face

in these individuals.

Our results compare favourably with those of tube pedicles in which only 80 per cent are successful (Stranc et al., 1975). Admittedly the technique is demanding and not


all surgeons may be temperamentally suited to it. It is for this reason that a team approach is so essential. Only one member need be expert in microvascular anastomoses; the others can relieve him of the rest of the operation.

SUMMARY

The operative technique of free groin flap transfer is described and some typical results presented. The overall complete success rate in 47 cases was 80 per cent, but complete necrosis only occurred in II per cent of the transferred flaps.

REFERENCES

DANIEL, R. K. and TAYLOR, G. I. (1973). Distant transfer of an island flap by microvascular anastomoses. Plastic and Reconstructive Surgery, 52, I I I.

HARII, K., OHMORI, K. and OHMORI, S. (r974a). Successful clinical transfers of ten free flaps by microvascular anastomoses. Plastic and Reconstructive Surgery, 53, 259.

HAIUI, K., OHMORI, K. and OHMORI, S. (19746). Free deltopectoral skin flaps. British Journal of Plastic Surgery, 27, 23 I.

MCGREGOR, I. A. and JACKSON, I. T. (1972). The groin flap. British Journal of Plastic Surgery, 25, 3.

O’BRIEN, B. M., MCLEOD, A. M., HAYHURST, J. W. and MORRISON, W. A. (1973). Success- ful transfer of a large island flap from the groin to the foot by microvascular anastomoses. Plastic and Reconstructive Surgery, 52, 271.

O’BRIEN, B. M., MORRISON, W. A., ISHIDA, H., MACLEOD, A. M. and GILBERT, A. (1974). Free flap transfers with microvascular anastomoses. Blr’tish Journal of Plastic Surgery,

STRA% “g’ F LABANDTER H and ROY A. (1975). A review of 196 tubed pedicles. Bri)tish’Jo&zal of Plastii Suigery, 28, ;4.

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Free groin skin flaps