Replantation of Amputated Digits and Hands in Children

JAMES R. URBANIAK, M.D. DONALD S. BRIGHT, M.D.


Summary

This study presents our experience with replantation of amputated digits or hands in 11 children. Although in young children the blood vessels are quite small, successful vessel anastomosis can be achieved. Our present feeling is that replantation of the thumb, index finger, multiple fingers, or the hand results in a more functional upper extremity than can be achieved by any type of prosthetic replacement.

Introduction

Despite recent advances in upper-limb prostheses, the ideal partial-hand prosthesis is yet to be developed. The old rule of "save all length possible," which is applicable to most levels of amputation, is especially important in dealing with damaged hands. Usually if two digits are salvaged, no prosthetic device is necessary; or, if a prosthesis is fabricated, it is seldom worn by the patient with the partial-hand amputation. With recent advances, partial-hand prostheses can be constructed to be cosmetically quite appealing, but the main deficiency is the absence of direct sensation. The hand prosthesis lacks stereognosis and is of little use in the dark. Particularly we have found that very few children will use a partial-hand prosthesis, except in special instances. For example, we had one patient with an amputation of the thumb through the base of the proximal phalanx. This teenager wore a thumb prosthesis to play the drums but did not wear the prosthesis at any other time because of its lack of sensory feedback.

There are many ways to reconstruct a damaged hand that has lost one or all of its digits. However, if the digits have been amputated, the ideal reconstruction is replantation. Stimulated by the success in replantations of amputated digits and hands with the aid of microsurgery as experienced by the Chinese, Japanese, and Australians in the past decade 2,3,4 , we have attempted to replant several digits and hands. Our orthopedic replantation team at Duke University Medical Center has had experience with 47 amputated digits or hands over the past two and one-half years6. Eleven of these amputated parts have involved children, that is, patients under 18 years of age. The purpose of this article is to present our experience with replantations in these 11 children and to describe our technique, results, and postoperative management, and some differences in the management of children and adults.

Prerequisites for Replantation

The advent of the operating microscope in 1960' made successful replantation of amputated digits and hands possible. If surgeons are to participate in replantation of amputated extremities, certain prerequisites are extremely important. It is necessary to have a surgical team which has had adequate practice in simulating small-vessel repair in laboratory animals. The surgical team should be able to accomplish 80 per cent patency rates using microvascular repair on vessels 1 mm in diameter. An operating microscope, preferably a diploscope with magnification at least up to 20 power, is suggested. Proper microsurgical instruments, which may vary to suit the individual surgeon's preferences, are absolutely essential. Spring-loaded instruments with noncatching handles are helpful. Microvascular clamps which will not damage the intima are essential. A method of rapid transportation, such as a helicopter service, is necessary if patients are to be transported over distances of more than a few hundred miles.

Care of the Amputated Part

The referring physician must be given simple and clear instructions in the management of both the amputated part and the injured patient. The referring physician is instructed to place the amputated part in a plastic bag containing Ringer's lactate or saline solution. The plastic bag is placed in ice so that the amputated part is chilled to about 4 deg. centigrade. Emphasis is placed on not freezing the amputated part. The referring physician is instructed not to ligate any vessels nor perfuse them with any type of solution such as heparin. A compression dressing is applied to the injured extremity or stump.

If the amputated part is not cooled in ice, tissues will survive for approximately six hours before undergoing necrosis from lack of arterial blood. However, an amputated digit will survive longer since there is no muscle tissue in the digit. If the amputated part is chilled it may survive for 12 hours, or even longer if it is a digit.

Patient Selection

The age range of our 47 patients is from 3 years to 52 years. Certainly the surgeon is more apt to attempt to replant an amputated digit or hand in a child than in the older patient, since the chances of obtaining a viable and functioning digit are greater. Also, to replant an amputated digit in a laboring man may keep him out of work for three to six months or even longer, whereas completion of the amputation and revision of the stump will allow him to return to work in a matter of a few weeks. For a child, loss of work does not pose a problem.

Clean, sharp, or guillotine-type amputations certainly are ideal. However, we have rarely seen this type of amputation because most of them are the avulsion or ragged type in children.

The site or level of amputation influences the surgeon's decision in attempting to replant the amputated part. We have been reluctant to attempt to replant an upper limb amputated proximal to the wrist unless it is a guillotine type of amputation. For amputations proximal to the wrist we certainly are more inclined to consider replantation if the patient is a child, since the functional outcome is likely to be better in a child.

Hand dominance is not an important consideration, generally. If the amputation involves most of the hand and successful replantation is achieved, the uninjured upper limb nevertheless will become the dominant limb if it was not previously.

We feel that the thumb on either hand of a child or adult should be replanted, especially if the amputation is proximal to the interphalangeal joint. Our experience with replanted thumbs has shown that all of them are better than any thumb that could be reconstructed by pollicization, toe transfer, or various other means of reconstructing the thumb. When a child sustains an index-finger amputation at the proximal interphalangeal joint or proximal to this area, replantation usually should be attempted. Amputation of multiple digits in children is an indication for attempts at replantation. If multiple digits have been amputated, we generally attempt to replant all of them if the amputations are at or proximal to the proximal interphalangeal joint. In most instances we would elect not to replant the long, ring, or little fingers if they are isolated amputations, even in children, although there is at times a considerable amount of parental pressure to do so.

Surgical Technique

The replantation team is divided into two subteams. One team cares for the amputated part, and the other team directs its attention to the patient. The amputated part is carried immediately to the operating room for thorough debridement and location of the vessels under an operating microscope. While the amputated part is being cared for, it is maintained on ice with a sterile covering to lower its metabolic needs. The amputated part usually arrives at the operating room prior to the patient's arrival, since the patient must have complete preoperative evaluation in the emergency room.

Most of our replantations have been performed under axillary brachial block using a long-acting local anesthetic (Marcaine®). In children, however, general anesthesia is usually required; and at times the anesthesia must last ten to twelve hours for replantation of multiple amputated digits. Nevertheless, brachial block has been used successfully in children as young as 13 years of age.

Once the vessels have been located and marked, the bone is shortened to achieve adequate length of the blood vessels with normal intima. The shortened bone is fixed with a small fixation K-wire, usually through the center of the bone so the digit can be rotated to approximate the vessels. An extensor tendon is repaired for further stabilization.

We attempt to repair two digital arteries if possible, and usually three veins. The veins are repaired after the arterial anastomosis has been completed and backflow from the veins is apparent. This practice helps the surgeon to visualize the veins. Also, it has generally been our policy to terminate the procedure and remove the replanted part if we do not achieve any venous backflow. We feel that if no backflow is achieved, the digit will not survive. It is essential to keep the blood pressure as high as possible at all times during the operative procedure, even in children, for a drop in the blood pressure may compromise the arterial supply to the replanted digit. After the completion of each arterial anastomosis, intravenous heparin is administered, usually about 1000 units for a child. Low-molecular dextran is also started at the time of surgery.

Nerves are repaired if there is sufficient time, or if the procedure has not been too prolonged. Most of our nerve repairs have been done two to four months later as a secondary procedure at the time of the flexor-tendon repair. We feel that these repaired nerves are equal or superior to the nerves that have been repaired primarily. We do not attempt to repair flexor tendons in a completely amputated digit, for the few that we have repaired have not functioned satisfactorily.

A 65-micron needle with 10-0 nylon is the type of suture that we prefer. Usually six to nine interrupted sutures are applied to each digital artery and vein. The interrupted sutures pass through all three layers of the vessel; minimal stripping of the adventitia is advocated5. Only a few skin sutures are applied, and most of the wound is left open to allow drainage from the wound. We frequently do fasciotomies extending along the entire digit in a midlateral incision to decompress the digit or replanted extremity.

A bulky compression dressing is applied above the elbow in the child as well as the adult. The fingertips are exposed so that they can be examined freely. The dressing is kept moist with Bunnell's solution to prevent development of a constricting type of dressing from the clotted blood. The nurse applies the Bunnell's solution every two to three hours.

Postoperative Management

Usually the hand is elevated in the bulky compression dressing with splints above the elbow to prevent slipping of the dressing. The position depends on the observations of the fingers during the postoperative course. If there appears to be venous congestion, the extremity is elevated; conversely, if there appears to be arterial insufficiency, the extremity is depressed. We feel that anticoagulation is essential even in the child. The child receives intravenous heparin (100 units/kg/4 hrs.) for the first seven to ten days. We also administer dextran (250 cc) every day for the first seven days in the case of a child. Chlorpromazine is administered three times a day for its peripheral dilating effect. Monitoring with a pulse-flow meter is useful in the postoperative period.

The child usually receives a stellate block after completion of the surgery. In the adult, a stellate block is given every day for about seven days. We usually do not perform these additional blocks in the child, however, since they are rather traumatic to the youngster. If stellate blocks are given, the neck must be examined carefully and frequently for signs of hemorrhage in the patient who is on heparin anticoagulation therapy. If there is fullness or induration in the deep anterior cervical area, the blocks are discontinued.

Because we have had some near catastrophes from early dressing changes, it is our current feeling that the dressing change on the replanted digit or hand should be delayed until at least a week after the replantation. In five hands with early dressing changes we have noted a vascular compromise of the amputated part, apparently secondary to vasospasm which was initiated by handling of the replanted part.

If there appears to be venostasis, we have found that massage of the amputated part has been helpful in a few instances. Antibiotic coverage is also given in all replantations for the first seven days.

Results

Utilizing the above management program, we have been able to achieve successful replantations in II of 16 completely amputated parts and 25 of3l incompletely amputated parts which were nonviable prior to replantation. In the 11 patients under 18 years of age, we have achieved successful replantation in three of five complete amputations and four of six incomplete amputations. Because most of these replantations have been done in the past two years, it is too early to judge the functional results in many of the digits. Certainly, several of the digits are still at early follow-up. However, there is no question about the success of the replanted thumbs. We have successfully replanted four completely amputated thumbs, and all have become quite functional with good pinch strength, useful sensation, as well as a good cosmesis. The replanted hands are certainly more functional than any type of below-elbow or wrist-disarticulation prosthesis.

We are more inclined to replant amputated parts in children than in adults. We also tend to reconstruct more structures in children than in adults, that is we are more likely to repair the flexor tendons and digital nerves in multiple completely or partially amputated digits. Although better results certainly are anticipated in the young, most of our thumb replantations have involved adults, and these have all done surprisingly well.

The adult proper digital vessel is usually 1 mm in diameter, and the common digital vessel in the palm of the hand is about 2 mm. In a child these vessels are one-half this size. We have been able to achieve successful anastomoses in vessels 0.5 mm in diameter in children in the age range of three to five years. Technically, the most difficult step in children this young is repair of the small veins, and in some patients we have been unable to find digital veins of adequate caliber for repair. If the amputation is incomplete, the digit will survive usually without repair of veins, but it has been our experience in completely amputated digits that it is vital to anastomose as many veins as possible, at least two.

We have had only one infection in our 47 replantations, and this occurred in a four-year-old child with a hand that was almost completely amputated by a potato-digging machine. The infection resulted in loss of the replanted part.

After the replanted part has proven to be viable in a child, we usually protect the digit with a cast above the elbow for about three weeks. With children it is not necessary to begin motion of the hand or digit as early as with adults.

Figures 1 and 2 illustrate two of our successful replantation cases. Fig.1-A shows the hand of a three-year-old child who caught her hand in the motor of a washing machine. The thumb had all structures severed except some dorsal skin. The bones, tendons, nerves, and vessels were completely severed to the index, long, and ring fingers. Following 13 hours of general anesthesia and microsurgery, all structures were successfully repaired. The hand is very functional six months postoperatively with motor and sensory function ( Fig. 1-B ).

Fig. 2-A shows a completely amputated thumb of a 16-year-old male. The thumb was replanted 11 hours after amputation. The bone, extensor tendon, two arteries, and three veins were repaired primarily. Fig. 2-B and Fig. 2-C show functioning thumb eight months after replantation. The nerves and flexor pollicis longus were repaired as a secondary procedure. Two-point discrimination is 5 mm and 7 mm on the ulnar and radial sides, respectively.

Division of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina

Division of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina

References:
1. Jacobson, J. H., and E. L. Saurez, Microsurgery in anastomosis of small vessels. Surg. Forum, 11:243, 1960.

2. Komaka, S. and S. Tamai, Successful replantation of a completely cut-off thumb. Plast. Reconstr. Surg., 42:374-377, 1968.

3. O'Brien, B. McC., and 6. 0. H. Miller, Digital reattachment and revascularization. J. Bone Joint Surg., 55A:7l4-724, 1973.

4. Replantation of Severed Fingers. Clinical Experience on 162 Cases Involving 270 Fingers. Shanghai, The People's Republic of China, The Research Laboratory for Replantation of Severed Limbs, No. 6 People's Hospital of Shanghai, July 1973.

5. Soucacos, P. N., J. R. Urbaniak, and R. S. Adelaar, Evaluation of microsurgical techniques in small artery anastomoses. Presented at the Annual Meeting of American Society for Surgery of the Hand, San Francisco, California, February 28, 1975.

6. Urbaniak, J. R., P. N. Soucacos, D. S. Bright, R. S. Adelaar, and J. L. Goldner, Replantation of amputated digits and hands with the aid of microsurgery. Presented at the Annual Meeting of the American Orthopaedic Association, Hot Springs, Virginia, June 23, 1975.