A versatile method for reconstruction of finger defects: reverse digital arteq flap

___--._-

______

S1 ~iVM.4R 1’. Four types of the reverse digital

artery flap-standard, extended, and innervated standard and extended-were developed for 52 finger defects. The arising pattern of the dorsal branch which was included in the innervated flap was studied and classified in cadaver dissections. Topographically, the described “ Lai’s line” is a useful guide to locate the underlying digital artery. Refinements in flap design and surgical technique resulted in favourable functional and cosmetic results. The average two-point discrimination of the reconstructed fingertip was 6.8 mm and 3.9 mm in the noninnervated and innervated flaps, respectively. This versatile flap is an ideal and reliable option for one-stage reconstruction of various finger defects.

Soft tissue reconstruction of the finger still remains ;I challenge for plastic surgeons because there is a relative shortage 01‘ available skin around the digit. Welldesigned local pedicled flaps are ideal for coverage of small or moderately-sized soft tissue defects of the finger; in place of classical multistage distant flaps. The surgical technique and design of the rev’erse digital artery Hap have been refined and favourable clinical results are presented. The development of extended and innervated flaps reported here grew out of a desire to cover major finger defects as well as to improve flap sensibility in the fingertip or the distal pulp.

creases (Type II) (Fig. 1B). In 3 (5” 0) c,pecimens one tnajor dorsal branch and one or .wc tninor dorsal branches were found (Type 111) (Fig. II:‘). In 2 (4”,0) main digital nerves no large dorsal branch was found. but several tiny twigs communicating with the dorsal digital nerve were noted (Type I\‘) (Fig. 1D). The cutaneous sensation in the lateral skin of the proximal phalanx is mainly supplied by tiny branches from the dorsal branch. The dorsal skin near ~.hc metacarpophalangeal joint which is included in the extended reverse digital artery flap. however. i< innervated b> the superficial sensory branch arborising from the corresponding radial or ulnar net-1 t:

Cadaver dissections Flap design and surgical technique (Fig. 2) The innervatton of the lateral skin of the tingers has not received a great deal of attention. Fifty six wellpreserved tnain digital nerves were carefully dissected under loupe magnification from 10 embalmed cadavers. The study was especially focused on the distribution pattern of the sensory dorsal branch and it:, anatomic relationship to the main digital nerve and artery tn the proximal phalanx. The main digital nerve in the digit bears a constant relationship to the main digital artery: they travel parallel courses contained within a fatty-areolar channcl between Cleland’s and Grayson’s ligaments through the full length of the digit. The dorsal branch passe< either deep or superficial to the digital artery. and courses obliquely to innervate mainly the ipsllateral dorsal skin of the middle phalanx. Four arising patterns of the dorsal branch were found (Fig. 1). Of 56 specitnens, the most common pattern occurred in 46 (X.1‘!,o) with the main digital nerves giving off the dorsal branches proximal to the proximal digital tlexion crcasz (Type I) (Fig. 1A). In 5 (9”~) cases the dorsal branches arose from the digital nerves at the level betwceti proximal and middle digital flexion

The flap is outlined over the lateral :surfacc of the donor proximal phalanx according to the sire and shape of the defect. With palpation or t’he aid of LI fine Doppler probe, the digital artery is identitied and marked. The junction of the dorsal and voiar skin in the lateral aspect of the digit forms a line wc call .’ Lai’s line” for the purpose of easy description. The skin is hairless and darker dorsal to Lai’\ line. whereas ventrally it is pink and relatively lighter. Preoperative marking of the line is helpful to find 1.1le underlying digital artery. Operation is carried out under regional block or general anaesthesia. With the aid of tourniquet control and loupe magnification. the skin incision is started from the proximal site of the tl,lp. The digital artery. is first identified and then carefully separated from the proper digital nerve and its dorsal branch. A rig-zag skin incision over the lateral surface of the digit is continued distally after division of th: proximal end of the digital artery. A thin cuff of wft tissue is left around the vascular pedicle and the latter should be

444

British Journal of Plastic Surgery

Fig. I.

For legend see facing

page.

Ri -

Fig.

I

446

British Journal

er

A

icroneurorrhaphy

D Fig. 2. For legend set facing

page.

digital

of Plastic Surgery

nerve

Ke\ersc

Dipltal

Artery

F’lap for Reconstruction

of Finp

Defects

dissected to the level at which the flap can easily reach the defect. Folll.>wing release of the tourniquet. haemostasis is \ecurcd and the flap is inset snugly with interrupted i 0 nylon sutures. A full-thickness skin graft from the groin is applied on the flap donor defect and secured with a tIeover bolster dressing. The involved digits are temporaril> immobilised with an aluminium plate. The hand 15 elevated postoperatively to minimise ~cnou:; congestion of the flap. and smoking is strictly prohibited. The patients are usually discharged from rhe ho,,ide of the index (34.6’10). 23 on the middle (44.2”~). 7 on the fourth ( 13.5Y”b). and 4 on the radial side of t’hc little tinger (7.7YjU). The length and width of Hap>, ranged from Z--5 cm and l-2 cm. respective]>. The maximum size of-the flap in this series was 5 x 2 cm. Of 52 flaps. overall morbidit) rate was about I5 “;, including tip necrosis in six flaps and complete loss in two. The latter occurred in a 9-year-old-girl who suffered volar contracture of the middle and ring tingers; both Haps used in reconstruction failed due to undue stretching of the vascular pedic.lcs. In cases of tip necrosis. the wounds were closed hy secondary intention healing without further graft. None of the surviving faps required thinning or revision. All patients were satisfied and used the digits without

01‘ the injury and types 01‘~IICreverse digital artery Hap for tin_ecr defects

cxcludrd

the fm_eertlp and distal pulp injurleb.

Figure ZP (.I) 7he rcvcrse digttal artery tlap contains lateral skin of the lnvolwd proximal phalanx as the standard type ( ‘t I I tc the defect and the donor uound is co\ercd wth :i full-thickness skin sraft A piece ofskin IS usual11 applied on the turn-over %nscular prdiclc to eliminate tensjon complercl\

British Journal

of Plasm

Surgeq

Fig. 3 Figure % -Small venules IV) and capillaries IC) within the pcrivascular fat wcrc noted near the digital artery (A) in its cross section at the level of the pro sximal phalanx. These small venules appear to represent adequate channels for venous drainage of the described flap. (H & E. IC)0X).

The lateral zig-zag incision scar and the grafted donor defect were hidden well in the shadow of the interdigital space except for hyperpigmentation of the grafted areas in some cases. Paraesthesia was noted in the ipsilateral dorsal skin of the middle phalanx in those patients where the dorsal branch was sacrificed. This symptom. however, was negligible in patients’ daily life according to their statements. Histological study showed the presence of venules and capillaries in the perivascular fat tissue (Fig. 3). Twelve noninnervated and 10 innervated flaps were entered into the study of sensation test after follow-up of at least 6 months. All flaps showed ability to detect light touch, sharp from dull stimuli. and hot from cold stimuli. The average result of the two-point discrimination was 3.9 mm and 6.8 mm in the innervated and noninnervated flaps, respectively. In the group of innervated extended flaps, however, the small area outside the distribution of the dorsal branch. which was previously innervated by the sensory branch of the radial or ulnar nerve. had relatively poorer sensation than the major portion of the flap from within the nerve’s territory. Four illustrative patients presenting with differently sited defects and variant reconstructed flaps are shown in Figures 4 to 7. difficulty.

Discussion

Various techniques have been attempted for reconstruction of soft tissue defects of the fingers, recently reviewed by Rose (1989). Swartz ( 1989) and Russell and Cases ( 1989). The recently developed adipofascial turnover flap (Lai et al., 1991) is limited to small dorsal finger defects. The principle of the neurovascular pedicle island flap in the hand was established by Bunnell (1952). Moberg (1955). Littler (1956) and

Tubiana and Duparc ( I96 I 1. Rose ( 1983) modified the flap design to include only the digital artery. leaving the nerve of the donor digit intact. Weeks and Wray (1973) first described the distally based island flap to reconstruct an exposed proximal interphalangeal joint. Lai et al. (1989) and Kojima et N/. (1990) extended its clinical applications to reconstruct fingertip defects. The flaps in our series were designed somewhat differently from those described by Kojima et rrl. ( 1990). They elevated the flap centred on the digital artery; the major portion of the flap was raised from the volar skin of the proximal phalanx. However, we used the lateral skin of the proximal phalanx only, and the vascular pedicle is located relatively to the ventral side of the flap. The advantage of the described design is three-fold: firstly, the grafted donor area. hidden well on the relatively inconspicuous lateral surface is aesthetically acceptable ; secondarily linear scar contracture can be prevented because the donor defect is not extended over the volar aspect of the digit; and thirdly an extended or innervated flap can be harvested. if necessary. Cosmetic reasons preclude elevation of the flap from the thumb. the radial lateral skin of the index and the ulnar lateral skin of the little finger. Under appropriate illumination, the described *’Lai’s line” is clearly seen in Black people and Orientals. but it may be less obvious in Caucasians. Topographically. the line provides an easy way to locate the underlying digital artery. The flap gains its blood supply from the opposite digital artery through abundant communications by retrograde perfusion. Therefore. preoperative assessment of the integrity of the digital artery on the opposite side of the digit should be performed carefully. Tension-free insetting of the flap is most important for its survival. It may not be possible to close the incised wound over the attached vascular pedicle. A small piece of skin is usually

British Journal

450

of Plastic Surgery

Fig. 5 Figure S-~-(A) A traumatic skin defect supcrimposcd uith secondary infection oker the dorsal ~tsp~ct of ;I proximal intcrphalan~c~ll joint in a Wyear-old man. (B) Joint exposure ensued after adquatc dcbridement. (C) Reconstruction of the defect wllh a standard Hap resulted in excellent appearance. The grafted donor site has hidden well in the relati\cly inconspicuous lateral aspect of the invohed digit. (D) Full range of joint motion of the injured finger was sholcn.

has been explained by several authors (Lin ct (11..1984: Timmons, 1984; Torii et N/.. 1987; Satoh ct ul., 1989). However, since the veins of the finger do not run along with the digital artery as venae comitantes (Eaton. 1968; Lucas. 1984; Cormack and Lamberty. 1986). the tiny venules and capillaries embedded in the per-

ivascular fat seem to provide sufficient channels for venous drainage of the flap. Microsurgical dissection with loupe magnification to include as much perivascular tissue as possible is quite important 10 preserve sufficient of these venules. Although the cutaneous sensory supply of the hand

I.‘ig

h;ls

been \rudicd

19.;');

DanI\nici~jur

(‘oupklnd.

branch

and

(Stopford.

Waltman.

I cJ’7i). the innervation

the prouim:ll dissecticw

previously

phalanx

and clinical

wnds

(in)

ib seldom results

hranche~

Ic)M;

IVI X:

of the law-al described.

confirmed to innerbate

P’An.

Waliacr skin

and ot

CadaLcr

that the dorsal the described

.lrw.

All

clinical tint

t\pe\ 01’ dorsal

sensation

population ha5

the

tingers

br,lnch

case4 c\ccpt type IV.

\\;I-c l’~luntl u’linlatc

dcpcnd:, on the prcwncc

of shin mo\t

The

receptor5

copious

Thec)retic:llly.

(Dellon.

number in addition

III

our

qualitv

01‘

01‘ ;I sutiicient

103 I 1. The

(>I‘ nxqtors

pulp

in

the

to tht. ingrowth

()I

452

nerve fibres from the recipient bed of the pulp and the wound margins, extra reinnervation through the microneurorrhaphy is provided (Cohen and Cronin. 1982). Microneurorrhaphy between the dorsal branch

British Journal of Plastic Surgery

and the transected digital nerve provides an innervation of the flap through the normal anatomic pathway. so cortical misinterpretation can be avoided. The innervated reverse digital artery fap was ob-

Reverse Digital Artery Flap for Reconstruction

of Finger Defects -

viously superior to the noninnervated one in sensory restoration, not only with respect to the level of sensory recovery but also in the speed of sensory return. The small size of the flap, the short length of the nerve, and the close proximity of the nerve and the vascular pedicle (resembling an in situ vascularised nerve graft) may be the main contributing factors. To our knowledge, this is the first report using innervated and extended reverse digital artery flaps for finger defects. The detailed distribution patterns of the dorsal branch originating from the proper digital nerve has also not apparently been described. The advantages of the described flap over the more conventional flaps are: 1. 2. 3. 4. 5. 6.

simple and one-stage procedure thinness and hairlessness of the flap short hospitalisation minimised disability time excellent sensory recovery acceptable cosmetic results

Experiences in 52 cases indicate that this versatile flap is an ideal and reliable option for one-stage reconstruction of various finger defects. The innervated flaps are recommended for fingertip and distal pulp defects, the extended flaps for major digit defects, and the standard flaps for other conditions.

Acknowledgement The authors wish to thank Dr Chee-Yin Tsai for his help in histological study and Dr Chin-Chiang Yang for enrolling 3 patients in this report. The skilful secretarial work of Shwu-Lih Horng is also appreciated.

References Biemer, E. and Stock, W. (1983). Total thumb reconstruction : a one stage reconstruction using an osteocutaneous forearm flap. British Journal of Plastic Surgery, 36, 52. Bunnell, S. (1952). Digit transfer by neurovascular pedicle. Journal of Boneand Joint Surgery, 34A. 772. Cohen, B. E. and Cronin, E. D. (1982). An innervated cross-finger flap for fingertip reconstruction. Plastic and Reconstructive Surgery, 72, 688. Cormack, G. C. and Lamberty, B. G. H. (1986). The Arterial Anatomy of Skin Flaps. Edinburgh, London, Melbourne. New York, Churchill Livingstone, p. 195. Dankmeijer, J. and Waltman, J. M. (1950). Sur I‘innervation de la face dorsale des doigts humans. Acta Anatomica, 10. 377. DeIIon, A. L. (1981). Evaluation of sensibifitJ> and reeducation of sensation in the hand. Baltimore, Williams and Wilkins, p. 169. Earley, M. J. and Milner, R. H. (1987). Dorsal metacarpal flaps. British Journal qf Plastic Surgery, 40, 333. Eaton, R. G. (1968). The digital neurovascular bundle. Clinics in Orthopedics, 61, 176. Foucher, G. and Braun, J. B. (1979). A new islanded flap transfer from the dorsum of the index to the thumb. Plastic and Reconstructive Surgery, 63, 344. Kojima, T., Tsuchida, Y., Hirase, Y. and Endo, T. (1990). Reverse vascular pedicle digital island flap. British Journal of Plastic Surgery, 43, 290. Lai, C. S., Lin, G. T., Sheen, M. C. and Lin, S. D. (1984). The forearm flap. Journal of Surger! Association. Republic qf China, 17, 30.

453

Lai, C. S., Lin, S. D. and Yang, C. C. (1989). The reverse digital artery flap for fingertip reconstruction. Annals of Plastic Surger.v, 22, 294. Lai, C. S., Lin, S. D., Yang, C. C. and Chou, C. K. (1991). The adipofascial turn-over flap for complicated dorsal skin defects of the hand and finger. British Journal of Plastic Surger.: 44. 165. Lin, S. D., Lai, C. S. and Chiu, C. C. (1984). Venous dramage in the reverse forearm flap. Plastic and Reconstructive Surgery, 74, 508. Littler, J. W. (1956). Neurovascular pedicle transfer of tissue in reconstructive surgery of the hand. Journal of Bone and Joint Surgery. 38A, 9 17. Lucas, G. L. (1984). The pattern of venous drainage of the digits. The Journal of Hand Surgery, 9A, 448. Maruyama, Y. (1990). The reverse dorsal metacarpal flap. British Journal of Plastic Surgery, 43, 24. Moberg, E. (1955). Transfer of sensation. Discussion. Journal of Bone and Joint Surgery, 37A. 395. P’An, M. T. (1939). The cutaneous nerves of the Chinese hand. American Journal of Physical Anthropology, 25, 301. Quaha, A. A. and Davison, P. M. (1990). The distally-based dorsal hand flap. British Journal of Plastic Surgery, 43. 28. Rose, E. H. (1983). Local arterialized island flap coverage of difficult hand defects preserving donor digit sensibility. Plastic and Reconstructive Surgery, 72. 848. Ruse, E. H. (1989). Small flap coverage of hand and digit defects. Clinics in Plastic Surgery, 16. 427. Russell, R. C. and Cases, L. A. (1989). Management of fingertip injuries. Clinics in Plastic Surgery, 16,405. Satoh, K., Okabe, K. and Matsui, A. (1989). Anatomical consideration for the venous drainage of the reverse-flow island flaps in the extremities (in the upper versus in the lower extremity). European Journal of Plastic Surgery, 12. 111. Stopford, J. S. B. (1918). The variation in distribution of the cutaneous nerves of the hand and digits. Journal of Anatomy, 53. 14. Swartz, W. M. (1989). Restoration of sensibility in mutilating hand injuries. Clinics in Plastic Surgery, 16. 515. Timmons, M. J. (1984). William Harvey revisited: reverse flow through the valves of forearm veins. Lancet, 8399, 394. Torii, S., Namiki, Y. and Mori, R. (1987). Reverse-flow island flap: clinical report and venous drainage. Plastic and Reconstructitre Surgery, 79, 600. Tubiana, R. and Duparc, J. (1961). Restoration of sensibility in the hand by neurovascular skin island transfer. Jourtzaf of Bone and Joint Surgery, 43B, 474. Wallace, W. A. and Coupland, R. E. (1973). Variations in the nerves of the thumb and index finger. Journal of Bone and Joint Surgery, 57B, 491. Weeks, P. M. and Wray, R. C. (1973). Management of acute hand injuries. St. Louis, Mosby. p. 140.

The Authors Chung-Sheng Lai, MD, Associate’ Professor, Division of Plastic Surgery Sin-Daw Lin, MD. Professor and Chief, Division of Plastic Surgery Chih-Kang Chou, MD, Assistant Professor. Division of Plastic Surgery Chin-Wei Tsai, MD, Attending Plastic Surgeon, Division of Plastic Surgery Division of Plastic Surgery, Chung-Ho Kaohsiung Medical College, 100 Shih-Chuan Taiwan. Requests

for reprints

Memorial Hospital, 1st Road, Kaohsiung,

to Dr. Lai at the above address.

Paper received 5 December 199 1. Accepted 13 March 1992. after revision. This paper was presented in part at the 6th ASEAN Congress Plastic Surgery held in Singapore in February 1992.

of

A versatile method for reconstruction of finger defects: reverse digital artery flap.

Four types of the reverse digital artery flap--standard, extended, and innervated standard and extended--were developed for 52 finger defects. The ari...
2MB Sizes 0 Downloads 0 Views