Digital nerve neurolysis plus Vivosorb barrier wrap (Polyganics) and Z-plasties to scar contracture left little finger

The patient is consented for exploration and neurolysis. This consent should include explanation of the risks of nerve injury necessitating reconstruction, loss of sensation from axonapathy, temporary numbness from oedema at the site of surgery, complex regional pain syndrome, recurrent scar formation and infection. I include consent for neuroma excision and reconstruction where appropriate.
The site of surgery is marked and a cross is placed at the site of maximal Tinel’s sign elicited by gentle tapping from a distal to proximal direction along the course of the repaired nerve.

Regional anaesthesia is performed at the axillary level to allow for tourniquet use and a bloodless surgical field. Prophylactic antibiotics are administered prior to tourniquet inflation. The second stage of the World Health Organisation checklist is completed prior to preparation of the limb.
The limb is prepared with an alcoholic antiseptic solution and then an Esmark bandage used to achieve exsanguination. The tourniquet is inflated around the upper arm and the limb draped.
The hand is positioned in supination using a lead hand, demonstrating the tension in the scar. The original traumatic injury was longitudinal in orientation and crossed flexor creases resulting in a post-operative contracture and loss of digital extension. The nerve repair is sensitised and tethered in this scar.

The scar os marked and the position of the Z-plasties is marked to ensure that the scar will be lengthened and the transverse limbs will lie parallel to the flexor creases.

The skin is incised with a size 15 scalpel blade and the skin edges mobilised from each side of the longitudinal scar.

Saline irrigation keeps the tissues moist under the theatre and microscope lights.

A skin hook is useful at this stage to facilitate access to the correct tissue plane superficial to the scar.

An Alm’s retractor is placed in the proximal wound and the skin hook used to elevate the radial skin edge for mobilisation from the underlying scar.

Tenotomy scissors are used to blunt dissect between skin flaps and scar.

Longitudinal blunt dissection is performed by opening the tenotomy scissors along the course of the digital nerves. This allows identification of the digital nerves with a low risk of iatrogenous injury.

A Ragnall retractor is placed under the radial skin flap and the distal radial neurovascular bundle is identified in the wound. This is an important step because the course of both digital nerves may be altered by scar tether.
DN = digital nerve

Dense scar is mobilised from the flexor sheath taking care to avoid damage to the neurovascular bundles. The distal ulnar digital nerve is identified and then careful dissection allows further mobilisation from the adherent scar tissue.

Sharp dissection with a scalpel blade is used to release the ulnar digital nerve from scar tissue.

A 90 degree Mixter forceps is passed under the ulnar distal digital nerve to facilitate passing of a surgical rubber sloop for retraction and completion of the neurolysis.

The Mixter is passed deep to the radial digital nerve to retrieve a yellow sloop.

The yellow sloop is placed parallel to the jaws of the forceps to facilitate passing deep to the nerve without snagging on the undersurface.

Blunt dissection of the proximal ulnar digital nerve with a Mixter forceps.

The ulnar digital nerve proximal to the site of previous repair is mobilised in preparation for passage of a second sloop.

The second sloop is passed deep to the ulnar digital nerve.

R = repair site
Microsurgical suture can be seen in the epineurium at the site of previous digital nerve repair.

The sloops can be used to retract the digital nerve to avoid excessive handling and tension.

360 degree circumferential neurolysis is completed along the course of the ulnar digital nerve with sharp dissection.

A small neuroma in continuity is identified at the site of previous repair. In this case the distal pre-operative sensation was reasonable and the plan was for neurolysis and wrap rather than for neuroma excision and reconstruction which would have been indicated had there been no functional recovery following the repair, or if during the neurolysis there was inadvertent neurotomy whilst dissecting the neuroma free from scar.

Yellow microsurgical background material is passed deep to the nerve to assist in wrapping with the Vivosorb wrap.

The Vivosorb is supplied by Polyganics. Is is a flexible bioresorbable polymer film which is designed to separate opposing tissues throughout the healing process. It retains mechanical strength up to 10 weeks. Hydrolysis results in resorbable degradation products which are metabolized and excreted by the body. Complete resoption takes up to 16 months. the polymer sheets are supplied in 0.2mm thick sheets with the following demensions:
2x3cm
5x7cm
13x10cm
12x17cm

Inside the Vivosorb box is an aluminium pouch.

A non-sterile Tyvek pouch is inside the aluminium pouch and this layer should be handled by the circulating theatre team member.

A 2 x 3cm Vivorsorb membrane is selected and soaked in saline to improve flexibility for handling. It is placed alongside the nerve on the microsurgical background in preparation for trimming to the optimum size for nerve wrapping along the course of the scar.

The Vivosorb membrane is trimmed to the required size using suture scissors.

A strip of Vivosorb is passed deep to the digital nerve in preparation for wrapping.

The Vivorsorb is sutured to itself around the digital nerve using a 7’0 prolene suture.

A series of interrupted suture are placed along the length of the wrap protecting the nerve from the scarred bed.

Four well-spaced sutures complete the repair. The neuroma is visible within the Vivosorb wrap.

The background material is removed and the wrapped nerve lies in the surgical bed.

The position of the marked Z-plasty incisions is confirmed and then they are incised and the skin flaps are mobilised.

The ulnar sided Z-plasty incision is opened.

The first Z-plasty at the base of the digit is inset breaking up the longitudinal scar, creating a transverse scar and adding length to reduce tension. The optimum angle for the Z-plasty cut is 60 degrees, enabling a lengthening of approximately 75% in the longitudinal scar.

The distal Z-plasty is completed in preparation for suture.

The skin flaps are opposed using 5’0 nylon interrupted sutures.

The neurolysed nerve and wrap is covered with the Z-plasty skin flaps recruiting lateral redundancy and creating length.

The sutured Z-plasties shows the laxity in the scar and detensioning the previous contracture across the MCPJ.

The completed wound closure.

A Mepitel silicone coated open weave non-adhesive dressing is applied to the wound. This base dressing allows and bleeding to pass through to the absorbent gauze outer dressing.

Dressing gauze is applied to the Mepitel dressing.

A bulky wool dressing is applied to the hand.

A volar Plaster of Paris slab is applied to maintain the extended posture of the digit.
A crepe outer bandage is applied and the tourniquet is released with arm elevation.
The digit reperfusion is noted to be normal and capillary return normal in the operated digit.

Following dressing reduction at 1 week the digit is straight without tension. Mobilisation may be commenced. A light dressing allows splint application.

A hand-based thermoplastic splint is made to maintain extension of the digit. The splint is worn initially by day between exercises and at night for a period of six weeks.

The dorsal view of the splint with straps to maintain extension of the digit and prevent scar contracture.

Side-on view of the splint showing full extension of the operated digit.