Abstract
This study reports the outcome of a series of ten microsurgical fingertip reconstructions with partial toe transfers in which the vascular pedicle was exteriorised and subsequently excised after the transfer had become established. The aim of this technique was to provide better aesthetic and functional outcomes. The technique was successful and without complication in nine of the ten patients who had excellent functional and aesthetic outcomes. Arterial thrombosis resulted in partial necrosis of the fingertip in the other case.
Distal pulp reconstruction for fingers using a free toe pulp transfer was first proposed by Buncke and Elliot (1979). This technique offered many advantages over other techniques with respect to the quality of the tissue transferred and reduced morbidity at the donor site. The cosmetic result is sometimes more important than the functional result for very distal reconstructions (Demirkan et al., 1999; Endo et al., 1997; Hirase et al., 1997; Wei et al., 1996; Woo et al., 2006) and the need for long incisions to anastamose the pulp transfer to good-quality vessels in the hand often reduces the aesthetic result. This problem can be partly resolved by defatting and shortening the pedicle and by performing the microsurgical anastamosis at the middle phalanx level (Dautel et al., 1998), but the anastamosis is then with small-calibre and thin vessels, which are prone to anatomical anomalies. This makes the procedure more demanding and increases the risk of failure. The senior author has proposed in a preliminary report a new technique of exteriorising the part of the pedicle that is normally tunnelled down the digit to the body of the hand (Brunelli et al., 1992, 1994). This part of the pedicle is the principal cause of scarring and can result in a bulky finger, with associated stiffness. Steilati et al. (2003) reported the use of this technique in reconstruction of the tips of two thumbs.
This paper reports the results of a series of ten distal finger reconstructions with partial toe transfers using an exteriorised pedicle.
PATIENTS AND METHODS
Between 1993 and 2003, ten patients underwent very distal finger reconstructions with partial toe transfers using an exteriorised pedicle (Table 1). There were six females and four males with a mean age of 11 (range 3–29) years. The middle finger was most commonly involved (four cases), followed by the ring finger (three cases), the index finger (two cases) and the little finger (one case). The tissue defects were due to traumatic injury to the hand in eight, and electrical burns in two, cases. In each case the pathology was strictly localised to the level of the distal phalanx. The mean time from injury to flap surgery was 6 months (range 15 days–26 months).
This series included a complete reconstruction of the distal phalanx of the index finger using a bone–pulp–nail flap (Fig 1), three reconstructions of the nail complex alone (Fig 2) and six reconstructions of the pulp alone.
The small number of patients demonstrates that patients were carefully selected before surgical intervention was proposed. In all of these cases, there were very good reasons to restore the hand’s appearance to as close to normal as possible, and these were expressed by the patients themselves and the parents in the cases of children.
Surgical technique
The procedure is performed under general anaesthesia with tourniquet control. Initially, the fingertip is prepared by the removal of scar tissue and preparation of the local tissue, including one of the digital nerves. The next two incisions, approximately 3 cm in length, are made just proximal to the base of the finger, one dorsally and one palmarly, to identify a digital vein and artery, respectively, in the required intermetacarpal space. A smaller opening is made in the web space and, using scissors with rounded ends, a tunnel is fashioned from this opening to the artery palmarly and to the vein dorsally. This tunnel receives the most proximal part of the pedicle and the artery is separated from the vein to allow microsurgical anastomoses of the vessels. This reduces the risks of tension and proximal detachment.
In cases of pulp reconstruction, the flap is raised from the lateral side of the big toe with one of the digital nerves and the donor site is closed directly. For reconstruction of the nail complex or of the complete distal phalanx, the flap is raised on the second toe with complete amputation of the distal phalanx to allow direct closure of the skin. The pedicle is raised without detaching it and is kept sufficiently long to allow reconnection of the vessels at the level of the hand.
The pedicle, with the cellular fatty tissue remaining intact, is left outside the skin (exteriorised) from the fingertip to the level of the web space and is covered with tulle gras (paraffin gauze). A second layer of tulle gras separates it from the operated digit. Its proximal end is then tunnelled under the skin through the small incision in the web space. The vein and artery are passed retrogradely with care using forceps and the vessels are anastomosed through the dorsal and palmar incisions. After closure of the skin, a large bandage is applied, leaving the digital tip transfer uncovered to monitor its vascularity.
During the period of time required for the flap to become established, which is between 15 and 21 days for a pulp transfer or a nail bed transfer and up to 4 weeks for a complete reconstruction of the distal phalanx, only the external bandage is changed, and the two pieces of tulle gras are left in place to avoid any traction on the microvascular sutures. The pedicle is clamped before it is divided to confirm the local vascularity of the transfer. If the local circulation is confirmed, the exteriorised pedicle is divided and the fingertip is refashioned under a local or a general anaesthetic.
Assessment
The assessment of the outcome of surgery included:
The length of hospital stay.
The success of the microsurgical procedure.
Examination of the scarring at the base of the recipient finger.
Evaluation of complications at the donor site.
Evaluation of the sensitivity of the digital tip using the static 2PD test.
Quality of finger motion was evaluated on the basis of direct observation of finger motion by the surgeons. It was considered ‘‘excellent’’ when all three aspects (flexion arc, digital coordination and speed of movement) appeared normal; good when two were normal; and poor when only one or none was normal (Tang, 2007).
The grip strength of the hand, tested using the Jamar Dynamometer (Jamar Hand Dynamometer, Clifton, NJ, USA). Grip strength was recorded as normal when it was greater than that of the contralateral hand for dominant hands or over 70% of that of the contralateral hand for non-dominant hands. It was otherwise considered reduced (Tang, 2007).
Nail growth was evaluated in cases of nail transfer.
Assessment of the donor and recipient sites for pain and cold intolerance.
Patient satisfaction with the appearance and the function was assessed by simple questioning of the patient and/or parents.
RESULTS
The mean hospital stay was 10 (range 9–12) days. The patients were evaluated objectively at a mean of 20 months (range 8 months–3 years) after surgery (Table 2).
Nine of the ten transfers performed using this modified technique were without complication. In the other case, a pulp reconstruction of the ring finger for an electrical burn in a 22 year-old woman, arterial thrombosis occurred several hours after the intervention and, despite further surgery, partial necrosis of the transferred tissue occurred. This healed spontaneously with some scarring and no further surgical intervention was necessary.
The scars on the palm at the base of the recipient fingers were, as expected, satisfactory and faded well. In all the patients, the incision in the middle of the web space, made to allow insertion of the pedicle, healed without scarring and did not cause a web space contracture.
The donor site was without complication in nine of the ten patients. However, a Z-plasty was necessary in one young child (patient no. 3 – transfer of the nail complex) to correct a contracture on the dorsum of the second toe. Sensitivity measurements in the transfer were done using the static two-point discrimination as the transfer was too small in some instances for evaluation with the moving two-point discrimination. The best results were achieved in children (patient no. 1 and 4).
Finger movement was excellent (Tang, 2007) in eight cases. The two cases in which it was reduced had sustained electrical burns.
The strength of the hand was classed as normal in nine out of 10 cases (Tang, 2007). In patient no. 9 strength was diminished (60% of the dominant hand) because of associated lesions from the electrical burn.
In all the cases of nail transfer (patient no. 2,3,6 and 7), growth of the transferred nails was normal when evaluated with a minimum follow-up of 2 years.
No patient with a follow-up greater than 2 years experienced postoperative pain or cold intolerance, either at the donor site or in the recipient fingers.
All the patients and their parents were satisfied with both the functional and the cosmetic results.
DISCUSSION
This paper reports ten cases of reconstruction of injuries of the distal pulp space and phalanx of the finger. Toe tip transfers to replace tissue loss in this region have been recognised for some time to be relatively free of complications and to provide excellent functional and cosmetic reconstructions (Dautel et al., 1998; Hirase et al., 1997; Woo et al., 2006). The results in this series with respect to the success of the procedure, fingertip sensitivity, nail growth, quality of finger motion, grip strength, lack of cold intolerance, lack of scarring, complications at the donor site and in the recipient finger and patient satisfaction confirm those of previous papers.
The senior author, having performed many reconstructions using the traditional technique of tunnelling the pedicle under the finger skin, has found that the described technique of exteriorising the pedicle significantly improves the aesthetic and functional outcomes as it reduces the amount of scarring in the recipient finger. The modification also makes the surgery easier and quicker and does not increase the failure rate. This technique is currently the senior author’s technique of choice for these reconstructions.
For the sake of safety, the patients were hospitalised for a relatively long period so that the vitality of their transfers could be monitored. The section of the pedicle left exteriorised has sufficient subcutaneous tissue to make the risk of desiccation minimal, provided that its vascularity and circulation is good. The one arterial failure in this series was probably due to the damage to the vessels from the electrical burn; reanastomosis was performed on the following day but partial necrosis of the transferred pulp still occurred (case 9).
Excision of the pedicle could lead to deterioration in the long-term results with respect to sensitivity, nail growth and conservation of the bone stock or pulp bulk but these problems did not occur in this series.
The authors have found no need to use this technique in the thumb, as described by Steilati et al. (2003), since the thumb’s skin is more flexible, it is easier to make the tunnel and the length of the tunnel is shorter.