Finger reattachment

Definition

Finger reattachment (or replacement) is defined as reattachment of the part that has been completely amputated.

Purpose

Replantation refers to reattachment of a completely severed part, meaning there is no physical connection between the part that has been cut off and the person. Reattachment can be surgically performed for the finger and such other detached body parts, as the hand or arm.

Demographics

Good candidates for this procedure include persons with thumb or multiple digit amputation . Injury to multiple digits is an important patient selection criterion, since in some cases the least damaged digits may be shifted to the least injured or most useful stump. Patient exclusion is neither clear-cut nor absolute. Generally, severe crushing or avulsing (tearing away) injuries to the fingers may make replantation difficult, but venous grafts may help replace injured blood vessels. Additionally, older persons may have arteriosclerosis that frequently impairs function in blood vessels, especially in small vessels. Special efforts may be made to replant fingers if the person's livelihood (such as professional musical performance) depends on absolute finger control.

Description

To increase efficiency, the replantation team splits into two sub-teams. One sub-team in the operating room cleans the amputated finger with sterile solutions, places it on ice, and identifies and tags (with special surgical clips) nerves and blood vessels. Dead or damaged tissue is surgically removed with a procedure called debridement . The emergency room (ER) sub-team will assess the patient during a physical exam with x rays of the injured area, blood analysis, and cardiac (heart) monitoring. The patient is given fluids intravenously (IV), a tetanus injection, and antibiotics . Usually, most finger reattachments are performed with a local anesthetic such as bupivacaine and a nerve block to numb the affected arm. Maintaining a warm body temperature can enhance blood flow to the affected limb.

The surgical procedure consists of several stages. The bone in the amputated finger must be shortened and fixed, which means that the bone end is trimmed. After this process, the bone is stabilized with special sutures called K-wires, and fixed pins are placed in the bone after drilling a space to insert them. This process connects the two amputated bone fragments. After bone stabilization and fixation, the extensor and flexor tendons are repaired. This step is vital, since arteries, veins, and nerves should never be surgically connected under tension. Next, the surgeon must repair (suture) cut-off tendons, arteries, veins, and nerves. Healthy arteries and veins are sutured together without tension. A vein graft is used for blood vessels that cannot be reattached.

Nerve repair for finger reattachment is not difficult. Since the reattached bone parts are shorter than the original length, nerves can be reattached without tension. A microscope is used for magnified visualization of finger nerves during reattachment. When the severed ends of the nerve cannot be reattached, a primary nerve graft is performed. Finally, it is vital superficial veins on the affected finger (dorsal veins) to cover with a skin flap to prevent death of the venous vessels. The skin over the surgical field is loosely sutured with a few sutures. Any damaged tissue that may die (necrotic tissue) is removed. No tension should be placed on the skin fields during closure of the wound. Wounds are covered with small strips of gauze impregnated with petrolatum. The upper extremity is immobilized, and compression hand dressing and plaster splints are arranged to prevent slipping and movement of the affected arm.

Diagnosis/Preparation

The diagnosis is easily made by visual inspection since the finger(s) must be completely detached from the hand. The reattachment procedure is complex and involves the expertise and skill of a highly trained surgeon. There are several important factors necessary to successful replantation, including special instrumentation and transportation of the amputated finger. Surgical loupes (binocular-type eyepieces used by surgeons to magnify small structures during surgery) are necessary for this procedure. Instruments should be at least 3.9 in (10 cm) long to allow for proper positioning in the surgeon's hands. Special clips are used to help suture blood vessels together. The best method of saving and transporting the amputated finger is to wrap it with moistened cloth (Ringer's lactate solution or saline solution) and place it on ice. Generally, the tissues will survive for about six hours without cooling. If the part is cooled, tissue survival time is approximately 12 hours. Fingers have the best outcome for transportation survival, since digits (fingers) do not have a large percentage of muscle tissue.

Aftercare

Postoperative care is vital for successful finger reattachment. The hand is wrapped in a bulky compression dressing and usually elevated. If arterial flow is impaired, then the hand should be lowered, since this maneuver will promote blood flow from the heart to the reattached finger. If venous outflow is slow, the hand must be elevated. Medications to increase blood flow (peripheral vasodilators) and an anticoagulant (heparin) are used. A tranquilizer may be given to reduce unnecessary blood vessel movement (vasospasm) that can occur due to anxiety. Careful examination of the reattached digit(s) is necessary. The surgeon frequently monitors color, the capacity of blood vessels, capillary refill, and warmth to monitor replant progress. The YSI telethermometer monitors the digital (finger) temperature with small surface probes. Skin temperature falling below 86°F (30°C) indicates poor blood perfusion

To save a detached finger for reattachment surgery, it should be wrapped in a moist paper towel and put on ice (A). First the surgeon will reattach the blood vessels and nerves of the finger (B). The bone may be repaired with wires (C), and tendons are repaired (D). Skin and muscle wounds are also closed during the procedure. (

Illustration by GGS Inc.

)

Risks

The experienced surgeon can estimate the likelihood complications based on the nature of the injury. Replantations that are risky, such as those with circulatory perfusion problems, have lower success rates. Generally, the most difficult replantations are those that involve children under 10, injuries caused by a ring catching in machinery, and crush-and-tear injuries. Management of the difficult replant typically includes intravenous heparin to prevent clotting of the blood, and providing a continuous nerve block in either the median or ulnar nerve (depending on which fingers are reattached). A nerve block will cause vasodilatation, or expansion of the blood vessel. Vasodilatation will increase blood flow, bringing with it fresh oxygenated blood. Further evaluation should include checking the patient's dressing for constriction (i.e., if the dressing was placed too snugly and is constricting local blood vessels).

Normal results

Normal results may not seem encouraging. It must be considered that this is a major trauma and a highly complicated and intricate surgical repair. Generally, a normal result usually includes good nerve recovery; approximately 50% of normal for active range of joint motion; cold intolerance (usually reversed in about two years); and acceptable cosmetic results.

Morbidity and mortality rates

There are about 10,000 cases of job-related amputations in the United States each year; 94% of these involve fingers. Few statistics are available for the out-come of replantations.

Alternatives

The only alternative to this procedure is to lose the finger(s) entirely and manage the remaining hand injury.

Resources

books

American Society for Surgery of the Hand. The Hand: Primary Care of Common Problems. New York: Churchill Livingstone, 1990.

Green, David P. Operative Hand Surgery, Volume 1, 3rd Edition. New York: Churchill Livingstone, Inc., 1993.

Green, David P. Operative Hand Surgery, Volume 2, 3rd Edition. New York: Churchill Livingstone, Inc., 1993.

organizations

American Association for Hand Surgery. 20 North Michigan Avenue, Suite 700, Chicago, Il 60602. (321) 236-3307; Fax: (312) 782-0553. E-mail: contact@handssurgery.org. http://www.handsurgery.org .

other

"Superficial Fingertip Avulsion." National Center for Emergency Medicine Informatics. [cited June 2003] http://www.ncemi.org/cse/cse1002.htm .

"The V-Y Plasty in the Treatment of Fingertip Amputations." American Academy of Family Physicians. [cited June 2003] http://www.aafp.org/afp/20010801/455.html .

Laith Farid Gulli, MD, MS

Bilal Nasser, MD, MS

Robert Ramirez, BS

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

The procedure is usually performed in a hospital operating room by a microsurgeon, who may be a plastic surgeon with five years of general surgery training, plus two years of plastic surgery training and another one or two years of training in microneurovascular surgery; or an orthopedic surgeon with one year of general surgery training, five years of orthopedic surgery training, and additional years in micro-surgery training.

QUESTIONS TO ASK THE DOCTOR

• Are there any special precautions I should take with my pain medication?
• How should I care for the wound?
• When will I regain feeling and function in the affected finger(s)?
• Will I need physical therapy for the injury?
• How much function can I expect to regain?