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THE HETERODIGITAL REVERSED FLOW NEUROVASCULAR ISLAND FLAP FOR FINGERTIP INJURIES
THE HETERODIGITAL REVERSED FLOW NEUROVASCULAR ISLAND FLAP FOR FINGERTIP INJURIES R. ADANI, R. BUSA, R. SCAGNI and A. MINGIONE From the Department of Orthopaedic Surgery, University of Modena, Modena, Italy
We report the results of pulp reconstruction with a new heterodigital reverse flow island flap. A dorsolateral flap from the middle phalanx, based on the digital artery is raised from the adjacent uninjured finger. The common digital artery, between the injured finger and the donor finger, is ligated and transected just before its bifurcation. The two converging branches of the digital arteries can be entirely mobilized as a continuous vascular pedicle for the flap. Thus the vascularization is now supplied by reverse flow through the proximal transverse digital palmar arch of the injured finger. To provide sensation the dorsal branch of the proper digital nerve from the donor finger can be included in the flap. Six reverse heterodigital island flaps were used in patients. In five patients the flap was used for pulp reconstruction and in one case for covering a dorsal digital defect. In one case mild venous congestion occurred. Good skin coverage with supple and well-vascularized skin was obtained in each patient. The static two-point discrimination over the flap was between 6 and 15 mm. This new procedure is indicated for extensive pulp defects in fingers in which reconstruction cannot be done using other flaps and as an alternative to microsurgical reconstruction. Journal of Hand Surgery (British and European Volume, 1999) 24B: 4: 431–436 Extensive loss of the digital pulp with bone exposure is a difficult reconstructive problem involving both cosmetic and functional aspects. Traditional techniques, such as the thenar flap (Quaba, 1991) and the cross-finger flap (Souquet and Souquet, 1986), need two surgical procedures; moreover they immobilize the fingers in unnatural positions with resultant joint stiffness and give poor recovery of sensibility. Direct homodigital neurovascular island flaps can cover limited defects not exceeding 2 × 2.5 cm in size (Adani et al., 1997; Foucher et al., 1989; Lanzetta et al., 1995; Venkataswami and Subramaniam 1980). Reverse homodigital island flaps require the integrity of the middle transverse digital palmar arch (Adani et al., 1995 a; b), which may be damaged in extensive pulp injuries. Direct heterodigital neurovascular island flaps are not suitable for extensive pulp losses in the middle finger because their neurovascular pedicle is not long enough to reach the defect. Free flaps (Buncke and Rose, 1979; Inoue et al., 1988; Ishikura et al., 1995; Kamei et al., 1993; Logan et al., 1985) have been largely employed recently and seem to produce satisfactory functional and cosmetic results. We present the results obtained with a new heterodigital island flap, which can be considered as a reverse-flow flap. It is proposed as an alternative to microsurgical reconstruction for large pulp defects involving the index and middle fingers.
under regional block, with the aid of tourniquet control and loupe magnification. The skin incision starts from the proximal border of the flap and is prolonged to the palm by a Bruner design. The digital artery of the flap is first identified and then carefully separated from the digital nerve. It is important to preserve as much subcutaneous tissue as possible around the pedicle to ensure inclusion of accompanying veins. If a neurovascular flap is to be performed, a dorsal sensory branch, arising from the digital nerve, is carefully dissected and sectioned proximally leaving a 1.5 cm nerve tail attached to the flap. The flap is then raised from distal to proximal and the pedicle is isolated up to its bifurcation in the palm. At this point the common digital artery between the injured finger and the flap-donor finger is dissected and, after ligation, it is transected just before its bifurcation. The two converging branches of the digital arteries can be entirely mobilized as a continuous vascular pedicle for the flap. This expedient considerably increases the length of the flap pedicle. Thus the vascularization is now supplied only by a “reverse-flow” system through the proximal transverse digital palmar arch of the injured finger (if the middle transverse palmar arch has been damaged). The flap can now reach the defect. The recipient digital nerve at the defect (usually the radial one) is dissected and a microneurorrhaphy is done to the sensory nerve of the flap. Since there is no accompanying vein a thin cuff of soft tissue should be left around the digital artery to provide channels for venous drainage from the flap as described in other similar flaps (Adani et al., 1995 a; 1997; Lanzetta et al., 1995; Leupin et al., 1997). The donor site defect is repaired with a full thickness skin graft. At the end of the operation, an aluminium splint is applied with the metacarpophalangeal (MP) and interphalangeal (IP) joints in slight flexion. Mobilization is started after 15 days.
SURGICAL TECHNIQUE (Fig 1) Allen’s test and a Doppler examination are done preoperatively to confirm the patency of the digital arteries of the injured and adjacent donor fingers. The flap is designed on the dorsolateral aspect of the middle phalanx of the adjacent uninjured finger according to the shape and size of the defect. The operation is carried out 431
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THE JOURNAL OF HAND SURGERY VOL. 24B No. 4 AUGUST 1999
a
c Fig 1
b
d
(a) Cadaver dissection after latex injection. Flap design on the dorsolateral aspect of the middle phalanx of the adjacent finger. The flap is raised from distal to proximal and the pedicle is isolated up to its bifurcation in the palm. (b) The common digital artery is transected just before its bifurcation. (c) The two converging branches of the digital arteries can be entirely mobilized as a continuous vascular pedicle. (d) The vascularization to the flap is now supplied by a “reverse flow” system through the proximal transverse palmar arch. The flap can be passed subcutaneously to reach the defect
HETERODIGITAL REVERSED FLOW FLAP
433
Table 1—Patient data Case
Sex
Age (years)
Affected finger
Injury/surgery (days)
Flap Dimensions (cm)
Complications
1 2 3 4 5 6
M M M F F M
30 33 45 22 48 16
R middle R middle R middle L index L index L middle
0 20 27 7 0 12
2.5 × 3 2.5 × 3.5 3×3 2 × 2.5 3×3 2.5 × 3
– – – Venous congestion – –
Table 2—Results. Blood flow values are expressed as percentage of the contralateral normal fingers. (n.a.: data not available) Case
Follow-up (months)
1 2 3 4 5 6
22 18 15 12 12 11
Motility (TAM)
Sensibility (weber test)
Recipient 200 270 195 270 250 260
s2PD 15 11 9 5 10 9
Donor 210 270 210 270 270 240
Sensibility (S-W test) m2PD 15 7 7 6 6 8
PATIENTS AND METHODS Between June 1995 and June 1996, six reverse heterodigital island flaps were used in six patients (Table 1), with an average of 32 years. All the operations were performed by the same surgeon (RA). In five patients the flap was used as a neurovascular flap for pulp reconstruction and in case 1 it was used for covering a dorsal digital defect. The nerve raised with the flap was sutured under magnification with 10/0 nylon. The donor finger was the index in four cases and the middle in two (cases 4 and 5). In one patient (case 4) venous congestion occurred in the early postoperative period and was relieved by removal of some sutures. In all cases the flap was transferred to the recipient finger via a subcutaneous tunnel in the palm to avoid another scar at the base of the reconstructed finger; this did not produce any compression of the vascular pedicle. A Bruner incision on the recipient finger enabled mobilization and insetting of the pedicle. All patients were reviewed over a post operative follow-up period of 11 to 22 months (mean, 15 months). The following parameters were assessed: flap and donor site skin quality; scar contractures; cold intolerance; neuroma formation; finger mobility expressed in terms of total active movement (TAM) of the MP and IP joints of the involved fingers; sensibility evaluated by the static and dynamic two-point discrimination (s2PD and m2PD tests) and the Semmes-Weinstein (SW) monofilament tests; and the examiner’s opinion of the cosmetic results graded as “excellent”, “good”, “fair” or “poor”. Four patients (cases 1,2,5,6) underwent a laser Doppler flowmeter examination to study the circulation of the
n.a. 2.83 4.31 2.83 3.61 4.31
Blood flow rate Flap –12% –12% n.a. n.a. –15% –18%
Donor finger –18% –20% n.a. n.a. –35% –40%
Examiner’s opinion Good Excellent Good Good Excellent Good
pulp of the donor and injured fingers and compare the flow values to the contralateral healthy fingers. RESULTS The results are summarized in Table 2. Good coverage with supple and well vascularized skin was obtained in each patient. In case 4 venous congestion in the flap was treated with partial removal of sutures, and this caused skin laxity in the pulp. There was a hyperthrophic scar along the margins of the donor site in two patients (cases 1 and 3). Scar contracture was recorded on the donor digit in case 3. Only one patient (case 3) complained of a mild intolerance to cold (in both donor and reconstructed fingers); however, this did not impair function in work and other activities. There were no painful neuromas. Mean TAM in the donor digit was 245°, and in the reconstructed finger it was 240°. The mean static twopoint discrimination over the reconstructed pulp was 9 mm and the mean dynamic two-point discrimination test was 7 mm. With the SW test two patients were shown to have normal sensation, one patient had diminished light touch sensation and two patients had diminished protective sensation. The results of the Doppler flow examination showed a slight decrease of the blood flow in the reconstructed areas, which proved to be stable over time. The pattern of the flow in the donor finger varied. In cases 5 and 6 it was significantly decreased after 12 and 11 months respectively. In case 2 this decrease was less evident after 18 months, while with case 1 blood flow was shown to be normal at 22 months follow-up. A typical case is shown in Fig 2 (case 2).
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THE JOURNAL OF HAND SURGERY VOL. 24B No. 4 AUGUST 1999
b
a
c Fig 2
d
Case 2: (a,b) Skin defect over the radial aspect of the pulp of the middle finger. (c,d) The common digital artery of the second space was isolated and ligated to increase the length of the pedicle to 7 cm.
HETERODIGITAL REVERSED FLOW FLAP
f
e Fig 2
435
Case 2: (e,f) Cosmetic and functional results of the reconstructed pulp 18 months after surgery.
DISCUSSION The idea of raising a flap distally on a branch of a Y-like vascular bifurcation, and turning the Y into a V is not new. This concept was introduced by Martin et al. (1994) and was subsequently used in hand surgery for dorsal finger reconstruction, employing the dorsal digital arterial network (Legaillard et al., 1996). Except for one case (case 1) we have used this technique for large losses of pulp from the index and middle fingers in situations where a homodigital island flap would have presented risks. For index pulp reconstruction the heterodigital island flap harvested from the distal phalanx of the middle finger always gives unsatisfactory cosmetic results at the donor sites. We prefer to use donor skin from the lateral side of the middle phalanx with the vascular pedicle located to the ventral side of the flap. In this way the grafted donor area is aesthetically acceptable and scar contracture can be prevented because the donor defect is not extended over the flexor aspect of the finger. An innervated flap can be harvested. The dorsal branch of the digital nerve is constant in all digital nerves and can easily be used to innervate the flap (Tellioglu and Sensöz, 1998). Leupin et al. (1997) using
the same donor area obtained sensory recovery results that were similar to ours and Hirasé et al. (1992) reported slightly better results than ours (min s2PD 5.5 mm; min m2PD 4.9 mm). After joining a recipient digital nerve to the dorsal digital nerve of the flap, sensibility did not reach the quality of the dorsum of a normal finger (Gellis and Pool, 1977). Numbness over the dorsum of the donor middle phalanx due to sectioning the dorsal branch is negligible compared with the sensory restoration of the involved finger pulp and painful neuromas did not occur. The risk of a painful neuroma is limited because the dorsal digital branch is localized in a deep layer after transection (Tellioglu and Sensöz, 1998). Lack of tension when placing the flap is important for its survival and the functional result. The lengthy vascular pedicle allows a large reach for the flap, without the need to flex the IP joints to cover defects in the middle or index fingers. This allowed us to obtain a very good recovery of range of digital motion without a deficit of extension of the PIP joint, as reported with the homodigital neurovascular flap with direct flow vascularization (Foucher et al., 1989; Massart and Foucher, 1988). There are two main disadvantages to this technique: the flap is taken from a healthy finger and also the
436
common digital artery of the second space is sacrificed with subsequent decrease of arterial flow during the first few months. However, the advantages include: the possibility of a one-stage reconstruction of extensive pulp defects with supple and well-vascularized skin; early postoperative mobilization and, hence, good functional recovery; a length of vascular pedicle that allows a wide arch of transposition of the flap for coverage of defects located in the middle and index fingers; satisfactory cosmetic and sensory results; and use of the flap for large pulp defects with bone exposure on the radial aspects of index and middle finger pulps, which are important for sensation (Leclerq, 1993). References Adani R, Busa R, Castagnetti C, Bathia A, Caroli A (1997). Homodigital neurovascular island flaps with “direct flow” vascularization. Annals of Plastic Surgery, 38: 36–40. Adani R, Busa R, Pancaldi G, Caroli A (1995a). Reverse neurovascular homodigital island flap. Annals of Plastic Surgery, 35: 77–82. Adani R, Marcuzzi A, Busa R, Pancaldi G, Bathia A, Caroli A (1995b). A propos du lambeau en îlot homodigital à contre-courant. Révision de 15 cas et de la littérature. Annales de Chirurgie de la Main, 14: 169–181. Buncke HJ, Rose EM (1979). Free toe-to fingertip neurovascular flaps. Plastic and Reconstructive Surgery, 63: 607–612. Foucher G, Smith D, Pempinello C, Braun FM, Citron M (1989). Homodigital neurovascular island flaps for digital pulp loss. Journal of Hand Surgery, 14B: 204–208. Gellis M, Pool R (1977). Two point discrimination distances in the normal hand and forearm. Application to various methods for fingertip reconstruction. Plastic and Reconstructive Surgery, 59: 57–63. Hirasé Y, Kojima T, Matsuura S (1992). A versatile one-stage neurovascular flap for fingertip reconstruction: the dorsal middle phalangeal finger flap. Plastic and Reconstructive Surgery, 90: 1009–1015. Inoue T, Kobayashi M, Harashina T (1988). Finger pulp reconstruction with a free sensory medial plantar flap: case report. British Journal of Plastic Surgery, 41: 657–659.
THE JOURNAL OF HAND SURGERY VOL. 24B No. 4 AUGUST 1999 Ishikura N, Heshiki T, Tsukada S (1995). The use of a free medialis pedis flap for resurfacing skin defects of the hand and digits: results in five cases. Plastic and Reconstructive Surgery, 95: 100–107. Kamei K, Ide Y, Kimura T (1993). A new free thenar flap. Plastic and Reconstructive Surgery, 92: 1380–1384. Lanzetta M, Mastropasqua B, Chollet B, Brisebois N (1995). Versatility of the homodigital triangular neurovascular island flap in fingertip reconstruction. Journal of Hand Surgery, 20B: 824–829. Leclerq C (1993). Management of fingertip injuries. Journal of Hand Surgery, 18B: 415. Legaillard P, Grangier Y, Casoli V, Martin D, Baudet J (1996). Le lambeau boomerang. Annales de Chirurgie Plastique Esthétique, 41: 251–258. Leupin P, Weil J, Büchler U (1997). The dorsal middle phalangeal finger flap. Journal of Hand Surgery, 22B: 362–371. Logan A, Elliot D, Foucher G (1985). Free toe pulp tranfer to restore traumatic digit pulp loss. British Journal of Plastic Surgery, 38: 497–500. Martin D, Legaillard P, Bakhach J, Hu W, Baudet J (1994). L’allongement pédiculaire en Y-V à flux rétrograde: un moyen pour doubler l’arc de rotation d’un lambeau sous certaines conditions. Annales de Chirurgie Plastique Esthétique, 39: 403–414. Massart P, Foucher G (1988). Résultats des lambeaux en îlot homodactyles unipédiculés. Annales de Chirurgie de la Main, 7: 158–162. Quaba A. Thenar flap. In: Foucher G (Ed.) Fingertip and nailbed injuries. Edinburgh, Churchill Livingstone, 1991: 87–91. Souquet R, Souquet JR (1986). Les indications actualles des lambeaux digitodigitaux dans les plaies des doigts. Annales de Chirurgie de la Main, 5: 43–53. Tellioglu AT, Sensöz Ö (1998). The dorsal branch of the digital nerve: an anatomic study and clinical applications. Annals of Plastic Surgery, 40: 145–148. Venkataswami R, Subramaniam N (1980). Oblique triangular flap: a new method of repair for oblique amputations of the fingertip and thumb. Plastic and Reconstructive Surgery, 66: 296–300.
Received: 23 October 1998 Accepted after revision: 8 February 1999 R. Adani MD, Department of Orthopaedic Surgery, Policlinico di Modena, Largo del Pozzo 71, 41100 Modena, Italy. © 1999 The British Society for Surgery of the Hand Article no. jhsb.1999.0164
We report the results of pulp reconstruction with a new heterodigital reverse flow island flap. A dorsolateral flap from the middle phalanx, based on the digital artery is raised from the adjacent uninjured finger. The common digital artery, between the injured finger and the donor finger, is ligated and transected just before its bifurcation. The two converging branches of the digital arteries can be entirely mobilized as a continuous vascular pedicle for the flap. Thus the vascularization is now supplied by reverse flow through the proximal transverse digital palmar arch of the injured finger. To provide sensation the dorsal branch of the proper digital nerve from the donor finger can be included in the flap. Six reverse heterodigital island flaps were used in patients. In five patients the flap was used for pulp reconstruction and in one case for covering a dorsal digital defect. In one case mild venous congestion occurred. Good skin coverage with supple and well-vascularized skin was obtained in each patient. The static two-point discrimination over the flap was between 6 and 15 mm. This new procedure is indicated for extensive pulp defects in fingers in which reconstruction cannot be done using other flaps and as an alternative to microsurgical reconstruction. Journal of Hand Surgery (British and European Volume, 1999) 24B: 4: 431–436 Extensive loss of the digital pulp with bone exposure is a difficult reconstructive problem involving both cosmetic and functional aspects. Traditional techniques, such as the thenar flap (Quaba, 1991) and the cross-finger flap (Souquet and Souquet, 1986), need two surgical procedures; moreover they immobilize the fingers in unnatural positions with resultant joint stiffness and give poor recovery of sensibility. Direct homodigital neurovascular island flaps can cover limited defects not exceeding 2 × 2.5 cm in size (Adani et al., 1997; Foucher et al., 1989; Lanzetta et al., 1995; Venkataswami and Subramaniam 1980). Reverse homodigital island flaps require the integrity of the middle transverse digital palmar arch (Adani et al., 1995 a; b), which may be damaged in extensive pulp injuries. Direct heterodigital neurovascular island flaps are not suitable for extensive pulp losses in the middle finger because their neurovascular pedicle is not long enough to reach the defect. Free flaps (Buncke and Rose, 1979; Inoue et al., 1988; Ishikura et al., 1995; Kamei et al., 1993; Logan et al., 1985) have been largely employed recently and seem to produce satisfactory functional and cosmetic results. We present the results obtained with a new heterodigital island flap, which can be considered as a reverse-flow flap. It is proposed as an alternative to microsurgical reconstruction for large pulp defects involving the index and middle fingers.
under regional block, with the aid of tourniquet control and loupe magnification. The skin incision starts from the proximal border of the flap and is prolonged to the palm by a Bruner design. The digital artery of the flap is first identified and then carefully separated from the digital nerve. It is important to preserve as much subcutaneous tissue as possible around the pedicle to ensure inclusion of accompanying veins. If a neurovascular flap is to be performed, a dorsal sensory branch, arising from the digital nerve, is carefully dissected and sectioned proximally leaving a 1.5 cm nerve tail attached to the flap. The flap is then raised from distal to proximal and the pedicle is isolated up to its bifurcation in the palm. At this point the common digital artery between the injured finger and the flap-donor finger is dissected and, after ligation, it is transected just before its bifurcation. The two converging branches of the digital arteries can be entirely mobilized as a continuous vascular pedicle for the flap. This expedient considerably increases the length of the flap pedicle. Thus the vascularization is now supplied only by a “reverse-flow” system through the proximal transverse digital palmar arch of the injured finger (if the middle transverse palmar arch has been damaged). The flap can now reach the defect. The recipient digital nerve at the defect (usually the radial one) is dissected and a microneurorrhaphy is done to the sensory nerve of the flap. Since there is no accompanying vein a thin cuff of soft tissue should be left around the digital artery to provide channels for venous drainage from the flap as described in other similar flaps (Adani et al., 1995 a; 1997; Lanzetta et al., 1995; Leupin et al., 1997). The donor site defect is repaired with a full thickness skin graft. At the end of the operation, an aluminium splint is applied with the metacarpophalangeal (MP) and interphalangeal (IP) joints in slight flexion. Mobilization is started after 15 days.
SURGICAL TECHNIQUE (Fig 1) Allen’s test and a Doppler examination are done preoperatively to confirm the patency of the digital arteries of the injured and adjacent donor fingers. The flap is designed on the dorsolateral aspect of the middle phalanx of the adjacent uninjured finger according to the shape and size of the defect. The operation is carried out 431
432
THE JOURNAL OF HAND SURGERY VOL. 24B No. 4 AUGUST 1999
a
c Fig 1
b
d
(a) Cadaver dissection after latex injection. Flap design on the dorsolateral aspect of the middle phalanx of the adjacent finger. The flap is raised from distal to proximal and the pedicle is isolated up to its bifurcation in the palm. (b) The common digital artery is transected just before its bifurcation. (c) The two converging branches of the digital arteries can be entirely mobilized as a continuous vascular pedicle. (d) The vascularization to the flap is now supplied by a “reverse flow” system through the proximal transverse palmar arch. The flap can be passed subcutaneously to reach the defect
HETERODIGITAL REVERSED FLOW FLAP
433
Table 1—Patient data Case
Sex
Age (years)
Affected finger
Injury/surgery (days)
Flap Dimensions (cm)
Complications
1 2 3 4 5 6
M M M F F M
30 33 45 22 48 16
R middle R middle R middle L index L index L middle
0 20 27 7 0 12
2.5 × 3 2.5 × 3.5 3×3 2 × 2.5 3×3 2.5 × 3
– – – Venous congestion – –
Table 2—Results. Blood flow values are expressed as percentage of the contralateral normal fingers. (n.a.: data not available) Case
Follow-up (months)
1 2 3 4 5 6
22 18 15 12 12 11
Motility (TAM)
Sensibility (weber test)
Recipient 200 270 195 270 250 260
s2PD 15 11 9 5 10 9
Donor 210 270 210 270 270 240
Sensibility (S-W test) m2PD 15 7 7 6 6 8
PATIENTS AND METHODS Between June 1995 and June 1996, six reverse heterodigital island flaps were used in six patients (Table 1), with an average of 32 years. All the operations were performed by the same surgeon (RA). In five patients the flap was used as a neurovascular flap for pulp reconstruction and in case 1 it was used for covering a dorsal digital defect. The nerve raised with the flap was sutured under magnification with 10/0 nylon. The donor finger was the index in four cases and the middle in two (cases 4 and 5). In one patient (case 4) venous congestion occurred in the early postoperative period and was relieved by removal of some sutures. In all cases the flap was transferred to the recipient finger via a subcutaneous tunnel in the palm to avoid another scar at the base of the reconstructed finger; this did not produce any compression of the vascular pedicle. A Bruner incision on the recipient finger enabled mobilization and insetting of the pedicle. All patients were reviewed over a post operative follow-up period of 11 to 22 months (mean, 15 months). The following parameters were assessed: flap and donor site skin quality; scar contractures; cold intolerance; neuroma formation; finger mobility expressed in terms of total active movement (TAM) of the MP and IP joints of the involved fingers; sensibility evaluated by the static and dynamic two-point discrimination (s2PD and m2PD tests) and the Semmes-Weinstein (SW) monofilament tests; and the examiner’s opinion of the cosmetic results graded as “excellent”, “good”, “fair” or “poor”. Four patients (cases 1,2,5,6) underwent a laser Doppler flowmeter examination to study the circulation of the
n.a. 2.83 4.31 2.83 3.61 4.31
Blood flow rate Flap –12% –12% n.a. n.a. –15% –18%
Donor finger –18% –20% n.a. n.a. –35% –40%
Examiner’s opinion Good Excellent Good Good Excellent Good
pulp of the donor and injured fingers and compare the flow values to the contralateral healthy fingers. RESULTS The results are summarized in Table 2. Good coverage with supple and well vascularized skin was obtained in each patient. In case 4 venous congestion in the flap was treated with partial removal of sutures, and this caused skin laxity in the pulp. There was a hyperthrophic scar along the margins of the donor site in two patients (cases 1 and 3). Scar contracture was recorded on the donor digit in case 3. Only one patient (case 3) complained of a mild intolerance to cold (in both donor and reconstructed fingers); however, this did not impair function in work and other activities. There were no painful neuromas. Mean TAM in the donor digit was 245°, and in the reconstructed finger it was 240°. The mean static twopoint discrimination over the reconstructed pulp was 9 mm and the mean dynamic two-point discrimination test was 7 mm. With the SW test two patients were shown to have normal sensation, one patient had diminished light touch sensation and two patients had diminished protective sensation. The results of the Doppler flow examination showed a slight decrease of the blood flow in the reconstructed areas, which proved to be stable over time. The pattern of the flow in the donor finger varied. In cases 5 and 6 it was significantly decreased after 12 and 11 months respectively. In case 2 this decrease was less evident after 18 months, while with case 1 blood flow was shown to be normal at 22 months follow-up. A typical case is shown in Fig 2 (case 2).
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THE JOURNAL OF HAND SURGERY VOL. 24B No. 4 AUGUST 1999
b
a
c Fig 2
d
Case 2: (a,b) Skin defect over the radial aspect of the pulp of the middle finger. (c,d) The common digital artery of the second space was isolated and ligated to increase the length of the pedicle to 7 cm.
HETERODIGITAL REVERSED FLOW FLAP
f
e Fig 2
435
Case 2: (e,f) Cosmetic and functional results of the reconstructed pulp 18 months after surgery.
DISCUSSION The idea of raising a flap distally on a branch of a Y-like vascular bifurcation, and turning the Y into a V is not new. This concept was introduced by Martin et al. (1994) and was subsequently used in hand surgery for dorsal finger reconstruction, employing the dorsal digital arterial network (Legaillard et al., 1996). Except for one case (case 1) we have used this technique for large losses of pulp from the index and middle fingers in situations where a homodigital island flap would have presented risks. For index pulp reconstruction the heterodigital island flap harvested from the distal phalanx of the middle finger always gives unsatisfactory cosmetic results at the donor sites. We prefer to use donor skin from the lateral side of the middle phalanx with the vascular pedicle located to the ventral side of the flap. In this way the grafted donor area is aesthetically acceptable and scar contracture can be prevented because the donor defect is not extended over the flexor aspect of the finger. An innervated flap can be harvested. The dorsal branch of the digital nerve is constant in all digital nerves and can easily be used to innervate the flap (Tellioglu and Sensöz, 1998). Leupin et al. (1997) using
the same donor area obtained sensory recovery results that were similar to ours and Hirasé et al. (1992) reported slightly better results than ours (min s2PD 5.5 mm; min m2PD 4.9 mm). After joining a recipient digital nerve to the dorsal digital nerve of the flap, sensibility did not reach the quality of the dorsum of a normal finger (Gellis and Pool, 1977). Numbness over the dorsum of the donor middle phalanx due to sectioning the dorsal branch is negligible compared with the sensory restoration of the involved finger pulp and painful neuromas did not occur. The risk of a painful neuroma is limited because the dorsal digital branch is localized in a deep layer after transection (Tellioglu and Sensöz, 1998). Lack of tension when placing the flap is important for its survival and the functional result. The lengthy vascular pedicle allows a large reach for the flap, without the need to flex the IP joints to cover defects in the middle or index fingers. This allowed us to obtain a very good recovery of range of digital motion without a deficit of extension of the PIP joint, as reported with the homodigital neurovascular flap with direct flow vascularization (Foucher et al., 1989; Massart and Foucher, 1988). There are two main disadvantages to this technique: the flap is taken from a healthy finger and also the
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common digital artery of the second space is sacrificed with subsequent decrease of arterial flow during the first few months. However, the advantages include: the possibility of a one-stage reconstruction of extensive pulp defects with supple and well-vascularized skin; early postoperative mobilization and, hence, good functional recovery; a length of vascular pedicle that allows a wide arch of transposition of the flap for coverage of defects located in the middle and index fingers; satisfactory cosmetic and sensory results; and use of the flap for large pulp defects with bone exposure on the radial aspects of index and middle finger pulps, which are important for sensation (Leclerq, 1993). References Adani R, Busa R, Castagnetti C, Bathia A, Caroli A (1997). Homodigital neurovascular island flaps with “direct flow” vascularization. Annals of Plastic Surgery, 38: 36–40. Adani R, Busa R, Pancaldi G, Caroli A (1995a). Reverse neurovascular homodigital island flap. Annals of Plastic Surgery, 35: 77–82. Adani R, Marcuzzi A, Busa R, Pancaldi G, Bathia A, Caroli A (1995b). A propos du lambeau en îlot homodigital à contre-courant. Révision de 15 cas et de la littérature. Annales de Chirurgie de la Main, 14: 169–181. Buncke HJ, Rose EM (1979). Free toe-to fingertip neurovascular flaps. Plastic and Reconstructive Surgery, 63: 607–612. Foucher G, Smith D, Pempinello C, Braun FM, Citron M (1989). Homodigital neurovascular island flaps for digital pulp loss. Journal of Hand Surgery, 14B: 204–208. Gellis M, Pool R (1977). Two point discrimination distances in the normal hand and forearm. Application to various methods for fingertip reconstruction. Plastic and Reconstructive Surgery, 59: 57–63. Hirasé Y, Kojima T, Matsuura S (1992). A versatile one-stage neurovascular flap for fingertip reconstruction: the dorsal middle phalangeal finger flap. Plastic and Reconstructive Surgery, 90: 1009–1015. Inoue T, Kobayashi M, Harashina T (1988). Finger pulp reconstruction with a free sensory medial plantar flap: case report. British Journal of Plastic Surgery, 41: 657–659.
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Received: 23 October 1998 Accepted after revision: 8 February 1999 R. Adani MD, Department of Orthopaedic Surgery, Policlinico di Modena, Largo del Pozzo 71, 41100 Modena, Italy. © 1999 The British Society for Surgery of the Hand Article no. jhsb.1999.0164