Case Report: Hand Replantation at The Mid Palm Level

Introduction

Hand amputation is a devastating injury that leads to loss of body image, sense of identity, functional and psychological impact, greatly decreasing the quality of life in every sense. Hence, the importance of early re-plantation can’t be over emphasized enough to achieve a successful functional result. Alexis Carrel, who won the Noble Prize in 1912 for his development of the vascular anastomosis technique, performed the first extremity replantation in a complete amputated canine hind limb in 1906.

After the first successful arm replantation, performed by Malt and Mckhan in 1962 and hand replantation that followed soon after by Chen in 1964, hand replantation has become an established and standard procedure.¹

Case

Our patient was a 20-year-old female who presented to the emergency department with history of complete amputation of her right (dominant) hand at the mid palm level involving all four fingers and sparing her thumb. The injury occurred by a sharp foam cutting machine at a factory that she was visiting when her hand accidently got caught in the machine. The amputated part was put on ice in a plastic bag and brought with the relatives and the stump covered with a cloth. The patient presented to our emergency within 30 minutes of the injury.

Procedure

While the patient was being prepped, and wheeled into the operating room, an imperative time saving step was bench surgery of the amputated part. Here all the vessels, nerves and tendons were identified under loupe magnification and tagged. The vessels were prepared by removing the damaged adventitia, and debridement of the injured nerves and tendons was done. This bench surgery is a crucial time saving step in re plantation surgery.

Under general anesthesia and tourniquet control, the right hand stump was thoroughly washed with copious amounts of saline and then was explored and the injured structures identified. The amputation level was oblique involving the MCP joint on the index finger extending diagonally, proximally and medially up to the base of the 5th metacarpal, just distal to the palmar arch.

The neurovascular structures and flexor tendons on the volar side, dorsal veins and extensor tendons were tagged.

Bone ends of the metacarpal were shortened by few mm and aligned with severed hand and rigid fixation done using K wires (1.2mm). The metacarpophalangeal (MCP) joint of index finger had to be sacrificed due to transection of the MCP joint and arthrodesis was achieved. Next the Flexor Digitorum Profundus tendons of all digits were repaired by Modified Kessler’s technique using 3-0 prolene and 5-0 prolene for the paratenon. The same method was used for the extensor tendons.

Four common digital arteries and dorsal veins were anastomosed under the microscope using 9-0 nylon. Digital nerves coaptation was done using 9-0 nylon and reinforced using fibrin glue. Hemostasis was ensured, skin closure was done and a dorsal slab was applied.

The patient was started on a continuous Dextran-40 infusion. She was shifted to the intensive care unit (ICU) for overnight observation and hourly monitoring of digit vascularity and was subsequently shifted to the ward after 24 hours. The total time from injury to completion of surgery was around 12 hours.

Outcome

The patient tolerated the surgery well, she was in Surgical ICU for 24 hours and hand monitoring by means of capillary refill time every hourly and continuous monitoring with Oxygen saturation probe was done. She was shifted to the ward after 24 hours under antibiotic cover and analgesics.

She was discharged on post operative day 5 with good perfusion in all the digits and a healthy suture line.

Discussion

Kleinert et al. performed the first digital arteries anastomosis in the revascularization of a partially amputated thumb in 1963.² The first replantation of a complete digit amputation using micro vascular anastomosis was performed by Komatsu and Tamai in 1965.³ These micro vascular techniques have improved greatly over the past few decades in regards to available magnification, available instrumentation and surgeon skill sets.

In our patient who presented within 30 minutes of the injury, was wheeled into surgery within the next two hours. The importance of time (i.e. time of injury to revascularization of the limb) cannot be over emphasized enough in amputation injuries and is the single most crucial factor determining the outcome.

The amputated digits may tolerate 12 hours of warm ischemia and 24 hours of cold ischemia. Other major amputations tolerate 6 hours of warm ischemia and 12 hours of cold ischemia because of their larger muscle content.

Another important factor is preservation of the amputated part. Most people tend to carry the severed part directly on ice. This is detrimental to the skin and structures and can lead to earlier necrosis.

The term cold ischemia actually refers to the described method of preservation of the severed part. The proper way of preserving the amputated part is to wrap the severed part in a clean, damp cloth, place it in a sealed plastic bag and place the bag in an ice or ice cold water bath. Do not put the body part directly in water or ice without using a plastic bag. Do not put the severed part directly on ice. Do not use dry ice as this will cause frostbite and injury to the part. This bag with ice should be kept in a fridge at 4 degrees.⁴

Bench surgery on the amputated stump is to essentially tag the structures that we plan to anastomose. This is undertaken while the preparation to shift the patient to OR right up to preparation of the stump is being undertaken. These few hours (usually 1-3 hours depending on the hospital, patient status etc.) are very crucial and greatly influences the outcomes. If a multi-team is available, a pair of fresh hands for anastamosis is also documented to improve the outcomes.⁵

Intraoperatively, the sequence of anastamosis and fixation that is described is macro to micro i.e. bones-tendons-vascular-nerve-skin, and that is now almost universally followed.⁶

The decision to start intra-operative low molecular weight dextran or heparin as a means to improve micro-circulation differs from center to center but our protocol is to start dextran-40 at 40ml/hr at the time of vascular anastamosis and continue till post-op day 5 and subsequently prescribe antiplatelet medication for 3 weeks.