British JournalofPlastic Surgery (1988), 41, 132-131 0 1988 The Trustees of British Association of Plastic Surgeons

Venous skin flaps: an experimental study and report of two clinical distal island flaps

J. AMARANTE, H. COSTA, J. REIS and R. SOARES

Department or’ Plastic and Reconstructive Surgery, Hospital S. Jolla, Oporto, Portugal

Summary-An experimental study of saphenous flaps in 26 dogs is reported, which confirmed the work of Baek et a/. (1985) that venous flaps can survive. In addition, it showed that venous island flaps could survive after division of the venous pedicle proximally or distally, or as free flaps, providing through flow was re-established by venous anastomoses. In this study no flaps survived on a single venous pedicle without through flow.

Two successful clinical cases of venous flaps are also reported, in which through flow was re- established by a simple venous anastomosis. One of these flaps threatened to become necrotic until the thrombosed anastomosis was successfully redone.

In 1985 Beehary et al. demonstrated the viability of a flap after arterialising one of the two veins which were its only vascular connections.

In the same year Baek et al. demonstrated experimentally the possibility of raising a flap based only on a single vein surviving without arterial inflow.

We have confirmed and extended the concept first described by Baek et al. both in experimental work and with clinical cases,

Experimental study

Material and methods

Twenty-six adult dogs of unknown race and age, weighing between 10 and 13 kg, had saphenous flaps raised. They were divided into 7 groups, each of which had the flap manipulated in a different way. Some dogs had flaps raised on both thighs.

General anaesthesia was induced with sodium pentobarbitone 40 mg/kg IV, with orotracheal intubation and spontaneous breathing. The opera- tive field was shaved and a sterile surgical technique was used. Haemostasis was achieved with electro- coagulation. A magnifying loupe or operative microscope was used when required. As in the experimental work of Baek et al. (1985), an axial flap was dissected in every animal from the middle of the medial aspect of the thigh. The flap was centred on the neurovascular pedicle which runs in a groove between the sartorius and gracilis muscles. The pedicle is formed by the long saphenous vein, saphenous artery and nerve.

In all groups the flap was completely raised and the pedicle was dissected proximally and distally. Every divided artery or vein from the pedicle was submitted to histological examination. At the end of the procedure each flap was sutured back into its bed. In groups V and VI it was necessary to dissect the short saphenous vein which begins on the dorsal aspect of the foot, runs along the lateral aspect of the leg and ends either in the popliteal or in the femoral veins (Bradley, 1927). In the postoperative period ampicillin and corticosteroids were admin- istered intramuscularly to prevent infection and reduce the flap’s oedema.

Group I(5 flaps). After raising the flaps, the long saphenous vein and nerve were cut proximally and distally, so the flaps remained based only on the saphenous artery (Fig. 1 A).

Group II (5 flaps). The saphenous artery and nerve were divided proximally and distally, so the flaps remained based only on the long saphenous vein (Fig. 1B).

Groups III and IV (5 flaps in each group). In both groups the saphenous artery and nerve were divided proximally and distally. In Group III the long saphenous vein was cut distally and ligated (Fig. 1 C) and in group IV was cut and ligated proximally (Fig. 1D).

Group V (5 flaps). The saphenous artery and nerve were divided proximally and distally, then the long saphenous vein was cut proximally. The short saphenous vein was cut distally and dissected

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VENOUS SKIN FLAPS: AN EXPERIMENTAL STUDY AND REPORT OF TWO CLINICAL DISTAL ISLAND FLAPS 133

proximally. This vein was transposed and the venous flow re-established by an anastomosis between its distal end and the proximal end of the long saphenous vein, with 10/O polyamide suture under the microscope (Fig. 1E).

Group VI (5 flaps). The saphenous artery and nerve were divided proximally and distally but this time the long saphanous vein was cut distally. The short saphenous vein was cut and dissected distally, transposed and anastomosis performed using the same technique as for Group V (Fig. 1 F).

Group VII (5 flaps). These flaps were transferred to the opposite hind limb as free venous flaps. To accomplish this, the long saphenous vein was carefully dissected and partially resected in the contralateral hind limb from which a disc of skin had been removed to produce a recipient area. Both ends of artery and vein entering the flap were divided and the arterial ends ligated. The flaps were transposed and venous continuity re-established by

A - Group I

two vein anastomoses, one distally and the other proximally, using the same technique as before. The flaps therefore remained based only on the saphenous vein (Fig. 1 G).

Results

Group I. At the end of the operation the flaps bled slightly cyanotic blood. The next day there was marked cyanosis and oedema and they were all obviously necrotic by the 5th to 7th day.

Group il. At first these flaps bled a little and appeared pale but were of normal colour by the end of the 2nd postoperative day. Slight oedema could be seen for 7 days but in this group there was no necrosis. About 15 days postoperatively hair started growing, which confirmed good vascularisation of the flaps.

Groups ZZZ and IV. In these groups, from the very beginning the flaps were cyanotic and all of them

S.S.V. ff c J

E - Group V

B - Group II

C - Group III

D - Group IV

,.A______

F - GroupVI

FREE FLAP

G - Group VII

Fig. 1

Figure l-Schematic illustration of the experimental groups. SA = saphenous artery, LSV = long saphenous vein, SSV = short saphenous vein.

134 BRITISH JOURNAL OF PLASTIC SURGERY

necrosed. Surgical exploration revealed thrombosis of the saphenous vein.

Group V. For the first 15 days the flaps were markedly cyanotic and oedematous. The operated hind limbs also had a transitory oedema. Necrosis (about 20%) was noticed in one of the flaps and in another total necrosis was revealed by the 4th day. Healing was uneventful in the other three flaps and hair growth was complete at the end of the first postoperative month.

Group T/I. During the first fortnight marked cyanosis and oedema were seen in the flaps. Slight oedema was also noticed in the hind limbs. Superficial skin necrosis was noticed in one of the flaps but all of the others healed uneventfully.

Group VZZ. At the end of the operation the flaps bled a little and appeared pale. Colour had returned by the end of the 4th postoperative day. Slight oedema could be seen for 7 days. One of the flaps necrosed completely because of thrombosis of the distal anastomosis. In all of the other flaps unevent- ful healing occurred.

Case reports and operative technique

Case Z A 19-year-old male had suffered a full thickness burn 10 years previously. Physical examination revealed an unstable scar on the ulnar border of his right hand, wrist and distal forearm. Sensory and motor function of the ulnar nerve were impaired. Doppler flowmeter evaluation showed that the ulnar artery was not patent within the lesion. In November 1985 the patient was operated on under general anaesthesia. The scar tissue was removed with associated neurolysis of the compressed ulnar nerve. A venous flap was then delineated, based in a forearm vein.

The flap was raised, including the deep fascia. The vein was dissected distally as far as the wrist to allow a good arc of rotation, then it was cut proximally and the flap was transposed to the defect. An end-to-end anastomosis was then performed with 10/O polyamide sutures between the proximal end of the flap vein and a previously selected vein on the dorsum of the hand. The donor area was split skin grafted.

On the 2nd postoperative day the flap was deeply blue. Surgical exploration of the anastomosis revealed venous thrombosis. The anastomosis was redone using the same technique, which restored the initial pink colour to the flap. Marked oedema was noted between the 2nd and 9th postoperative day and the sutures were removed on the 15th day.

A good end result was achieved both functionally and aesthetically (Fig. 2).

Case 2

A 16-year-old male sustained a firework injury to his right hand 2 years before referral. Physical examination revealed loss of the second finger and the distal phalanges of the first and third, as well as some muscle and soft tissue loss of the first web-space, with scar contracture.

In March 1986 the scar contracture was released and a distally based island venous skin flap was raised from the right forearm and transposed. As in the previous case, an anastomosis was performed between the proximal end of the vein and a selected volar wrist vein. Uneventful healing occurred (Fig. 3).

Discussion

In the experimental groups I and II we have confirmed the findings of Baek et al. (1985) and Thatte and Thatte (1987) that veins are more important than arteries in skin flap survival.

In groups III and IV we verified Baek’s findings that if there was not a through flow of venous blood, all the flaps would necrose. This is contrary to the experimental studies of Thatte and Thatte (1987) and suggests that the clinical transfer of an island venous flap, based on a single vein with the proximal or the distal pedicle cut, would lead to flap necrosis.

Groups V and VI of our experimental work testify to the viability of a flap where through-and- through venous flow has been re-established by vascular anastomosis, with the valves in the normal direction, utilising another vein as one might clinically in a transposed island flap.

Groups V, VI and VII of the experimental work, as well as the first clinical case in which the flap would probably have necrosed if the venous anastomosis had not been redone, confirm the necessity of through flow as well as of a correct anastomosis to avoid venous thrombosis.

The encouraging experimental results obtained led to the use of venous flaps in two clinical cases. This was considered ethically justifiable as there was always the possibility, if necessary, of trans- forming a venous flap into a full thickness skin graft if it became obvious that it would not survive as a flap.

While further experience is required to identify the limitations of the technique, we believe that venous flaps, with restoration of through flow, are likely to become a valuable and versatile addition to the choices available to the reconstructive surgeon. Potential donor sites are almost infinite and large arcs of rotation are possible. They are

VENOUS SKIN FLAPS: AN EXPERIMENTAL STUDY AND REPORT OF TWO CLINICAL DISTAL ISLAND FLAPS 13.5

Fig. 2

Figure Z-Case 1. (A) The defect and the flap outlined. (B) The dissection of the flap. (C) The raised venous flap based only on the venous pedicle. (D) The flap with its venous pedicle. (E) The venous pedicle flap divided proximally. (F) The flap transferred to the defect, (G) The flap showing oedema and cyanosis. (H) The final result.

136 BRITISH JOURNAL OF PLASTIC SURGERY

Fig. 3

Figure 3-Case 2. (A) 1st web-space contracture; venous flap raised. (B) Dissection of the flap based only on the vein. (C) Distal dissection of the pedicle. (D) The donor defect and reconstructed 1st web-space. (E) Flap appearance on the 5th postoperative day. (F) The final remit. (G) Another view of the flap. (H) The dorsal aspect of the hand.

VENOUS SKIN FLAPS: AN EXPERIMENTAL STUDY AND REPORT OF TWO CLINICAL DISTAL ISLAND FLAPS 137

quicker and simpler than free flaps, require only a single vascular anastomosis and should have little donor site morbidity.

Acknowledgements

We wish to thank ProfessorsDrs Casimiro Azevedoand Cardoso de Oliveira, Directors of the Department of Experimental Surgery, Oporto University and Dr Fernando Carvalho for his helpful advice in veterinary medicine.

References

Baek, S. M., Weinberg, H. Y., Park, C. G. and Biller, H. F. (1985). Experimental studies in survival of venous flaps without arterial flow. Plastic and Reconstructive Surgery, IS, 88.

Beebary, S., Hoang, Ph. and Foucber, G. (1985): L’arterialisation des lambeaux veineux. Annales de Chirurgie Plastique et EsthPtique. 30.95.

Bradley, 0. C. (1927). Topographical Anatom), of the Dog. Edinburgh: Oliver and Boyd.

Thatte, R. L. and Thatte, M. R. (1987). A study of the sapbenous venous island flap in the dog without arterial inflow using a non-biological conduit across a part of the length of the vein. British Journalof Plastic Surgery, 40, 1 I.

The Authors

J& Amarante, MD, Consultant Plastic Surgeon Horhcio Costa, MD, Resident Plastic Surgeon Jorge Reis, MD, Resident Plastic Surgeon Ribeirinho Soares, MD, Resident Plastic Surgeon

Department of Plastic and Reconstructive Surgery. Hospital S. Joao, 4200 Oporto, Portugal.

Requests for reprints to Dr Jose Amarante at the ahove address.

Paper received 5 February 1987. Accepted 9 October 1987 after revision.