Littler Neurovascular Island Flap in the Loss of Pulp Substance of the Thumb

Questions

Q1. How can this defective soft tissue be covered?

Q2. What are the surgical requirements and postoperative instructions?

Q3. What indicators are used to assess the sensitivity of the flap?

Q4. How is the impact of this type of flap on the patient's daily life evaluated?

Case Description

A 21-year-old nonsmoking student presented with complete soft tissue degloving of the ulnar and radial side of the thumb pulp of the right dominant hand following a work-related accident. The proper palmar digital nerves were avulsed to the fingertip and could not be repaired (Figure 1). The bone and ulnar part of the distal phalanx of the thumb as well as the insertion of the flexor pollicis longus tendon were exposed.

FIGURE 1.

Loss of substance of the thumb pulp, palmar view and front view..

Questions

Q1. How can this defective soft tissue be covered?

The use of the Littler flap simultaneously restores the defective soft tissue mantle as well as the sensitivity necessary for a precise, sharp grip with the long fingers. The Littler heterodigital neurovascular flap was proposed for this case after making a preoperative inquiry regarding the sensitivity of the donor site and the condition of the adjacent finger.

Q2. What are the surgical requirements and postoperative instructions?

The donor site was represented by the ulnar hemi-pulp of the 3rd finger; the dissection of the pedicle was performed using a modified Brünner approach. This incision continues along a broken path in the palm and will isolate the pedicle as a monobloc, including artery, nerve, and peripedicular fatty environment (Figure 2A).

FIGURE 2.

(A) The donor site is represented by the ulnar hemi-pulp of the 3rd finger, (B) after dissection, a satisfactory length of 8 to 10 cm was obtained, (C) subcutaneous tunnelling of the flap, (D) final aspect after grafting the loss of substance.

In the palm, the dissection is continued by ligating and transecting the radial collateral artery of the 2nd finger. An intraneural dissection is necessary to separate the fascicular contingent intended for the flap from that intended for the radial hemi-pulp of the adjacent 2nd finger. A useful length of 8 to 10 cm was obtained during the dissection (Figure 2B). The flap was brought in situ at the thumb by tunnelling under the thenar skin while avoiding tension or compression of the pedicle and then was sutured with separate 4/0 nylon sutures (Figure 2C). The donor site was closed with single stitches because the size of the flap did not exceed one-fourth of the circumference of the finger (Figure 2D).

A fatty dressing was applied to the recipient site, followed by immobilization of the interphalangeal with a protective thumb splint at 30° flexion for 2 weeks, with monitoring of flap viability at D3 (Figure 3). Thereafter, active-passive joint exercises and sensory rehabilitation were performed under the guidance of a physical therapist.

FIGURE 3.

Change of dressing at D3 to see the viability of the flap.

Q3. What indicators are used to assess the sensitivity of the flap?

At final follow-up, the Semmes-Weinstein monofilament test and the static 2-point discrimination test¹ were used to measure flap sensitivity and donor site pulp.

Cortical reorientation of Littler flaps was assessed by a needle prick by asking the patient whether the stimulus was from the recipient finger or the donor finger. If the stimulus was recognized from the recipient site rather than the donor site, cortical reorientation was considered complete. In contrast, if the stimulus was apparent from the donor site or both sites, this indicated incomplete cortical reorientation. In addition, the cold intolerance of the flap and donor finger were assessed using the self-administered Cold Intolerance Severity Score questionnaire,² which is a crucial indicator to assess the influence of cold sensitivity in daily life.

Q4. How is the impact of this type of flap on the patient's daily life evaluated?

Because of the importance of the appearance of the recipient thumb and donor finger, we assessed satisfaction using the Michigan Hand Outcomes Questionnaire.³ The questions were based on a 5-point response scale. In addition, pain and scar contracture were assessed using patient evaluations.

The flap survived completely without ischemia or congestion. The reconstructed thumb pulp returned to a hairless texture and appearance with warmth and satisfactory capillary refill 3 weeks after surgery. The patient returned to his usual activities 8 weeks after surgery.

According to the Semmes-Weinstein monofilament test grading, the reconstructed thumb pulp as well as the flap had normal sensation with complete cortical reorientation, and the donor site pulp showed mild cold intolerance (Cold Intolerance Severity Score < 25). According to the Michigan Hand Outcomes Questionnaire, the patient was highly satisfied with the appearance of the flap and donor finger. No pain, scar contracture, or hooked nail deformity was reported on the recipient or donor fingers (Figure 4; Video 1, Video 2, and Video 3).

FIGURE 4.

Flap appearance 8 weeks after surgery.

Summary

Because of its importance in grasping, pinching, and feeling an object, the thumb pulp requires adequate reconstruction. The Littler flap was chosen for this reconstruction because it has a large radius of rotation due to its long vascular-nervous pedicle and can also reach distant areas without tension.⁴

The Littler flap is an option for reconstructing soft tissue defects of the thumb and index finger with sensory deficit. Due to its long pedicle, remote areas can be easily reached. Due to its tissue texture, it adapts well to defects of the thumb and distal index finger. The morbidity is mainly related to insufficient fleshing of the donor finger and discomfort related to the insensitivity of half of the finger, which rarefies its indications. Trophic disturbances, intolerance to cold, and circulatory disorders may occur and have a lasting effect on the patient.