Operative Techniques in Orthopaedic Surgery (4 Volume Set) 1st Edition

340. Revascularization and Replantation of the Digits

Marc Richard, R. Gordon Lewis, Jr., and L. Scott Levin

DEFINITION

images Replantation is the reattachment of a completely amputated body part.

images Revascularization is the restoration of circulation and repair of all injured structures in an incompletely amputated, dysvascular body part. Revascularization always includes repair of the arteries to re-establish blood flow to the part.

images Revision amputation is the procedure performed at the site of amputation to gain soft tissue coverage and to address concomitant injuries to the digit.

images The decision of whether to perform replantation or revascularization and revision amputation of a digit is multifactorial. The relative indications and contraindications for each are discussed later in the chapter.

ANATOMY

images An understanding of the anatomy over the complete length of the digit is essential for successful replantation. The anatomy of the thumb is different from that of the four fingers.

images Palmar and dorsal cutaneous ligaments maintain the position of the neurovascular bundle during range of motion of the digit.

images Grayson’s ligament is palmar to the neurovascular bundle, originates from the flexor tendon sheath, and inserts on the skin.

images Cleland’s ligament travels dorsal to the neurovascular bundle from the phalanx to the overlying skin.

images A radial and ulnar proper digital artery supplies each digit. Each vessel travels with a respective radial and ulnar proper digital nerve. At the level of the digit, the artery lies dorsal to the nerve.

images The ulnar digital artery is typically larger in the thumb and index finger. The radial digital artery usually is larger in the small finger.

images Three major palmar arches arise from the digital arteries. The proximal, middle, and distal arches are consistently located at the level of the C1 pulley, C3 pulley, and just distal to the flexor digitorum profundus (FDP) insertion, respectively.

images Four palmar and four dorsal branches usually extend from each digital artery.

images Injection studies have demonstrated that the venous system of the digit consists of a series of arcades on the dorsal and palmar surfaces, with connecting oblique and transverse anastomotic veins.14 The dorsal veins have a larger caliber than the palmar veins, which do not consistently travel with the digital artery and nerve.

images A radial and ulnar proper digital nerve travels with each proper digital artery. The digital nerve is sensory only and typically contains one to three fascicles. It trifurcates at the level of the distal interphalangeal (DIP) joint.

images Each finger has two flexor tendons within the flexor tendon sheath.

images The FDP tendon inserts at the proximal base of the distal phalanx.

images The flexor digitorum superficialis (FDS) tendon inserts as two slips into the midportion of the middle phalanx. The FDS tendon splits into two slips, and its relative position to the FDP tendon switches from palmar to dorsal at Camper’s chiasm. This allows the deeper FDP tendon to continue to its more distal insertion.

images There are a series of five annular and three cruciform pulleys, which are discrete thickenings of the fibro-osseous sheath. The annular pulleys prevent bowstringing of the flexor tendons during flexion, whereas the cruciate pulleys are collapsible, accommodating flexion.

images The odd-numbered annular pulleys are located over the joints of the finger, and the even-numbered annular pulleys are over the proximal and middle phalanx, respectively.

images The A2 and A4 pulleys are most important in preventing bowstringing and should be preserved if possible.

images Each lesser digit receives a tendon from the extensor digitorum communis (EDC). The index and small fingers each have a second extensor tendon, the extensor indicis proprius (EIP) and extensor digiti minimi (EDM), respectively. Both of these tendons are ulnar to the EDC tendons.

PATHOGENESIS

images The mechanism of injury has a considerable effect on the potential for replantation.

images Sharp amputations are ideal for replantation because of the narrow zone of injury.

images The degree of tissue injury increases substantially with crush and avulsion mechanisms and may prohibit successful replantation (FIG 1).

images Most digit amputations occur as an isolated injury. When amputations occur in the multiply injured patient, consideration of other systemic injuries and adherence to ATLS (Advanced Trauma Life Support) protocols may prevent replantation.

NATURAL HISTORY

images Replantation of an amputated digit results in longer hospital stays and more prolonged rehabilitation than revision amputation. Patient satisfaction, however, usually is higher with replantation than with revision amputation or a prosthesis.11,15,16

images Functionally, the expected range of motion in a replanted digit is 50% of normal.

images Secondary procedures, such as tenolysis, are common.

images The literature reports rates of reoperation ranging from 3% to 93%. In a series of more than 1000 replants and revascularizations, 35% of patients required at least one secondary surgery.22 The incidence is higher for replantations than for revascularizations.

images Expected survival rates of replanted digits are 80% or higher, with even higher survival rates in revascularized digits.

images

FIG 1  A. This hand sustained sharp amputation of the digits from a table saw. The narrow zone of injury made the digits ideal for replantation. B. This hand sustained a crush injury. The resultant wide zone of injury prohibited successful replantation.

PATIENT HISTORY AND PHYSICAL FINDINGS

images The surgeon must evaluate the patient in the emergency room immediately on arrival. A complete history and physical examination are performed.

images The history should include specific details regarding the mechanism and timing of the injury. Identification of the specific machinery involved often reveals valuable information about potential contamination and the pattern of injury sustained by the amputated part.

images A history of mental instability is relevant, because rehabilitation protocols require significant patient compliance to maximize functional outcomes. Furthermore, self-inflicted amputations are unlikely to yield the same functional results after replantation as accidental amputations.

images A history of medical comorbidities should be thoroughly evaluated. Conditions such as diabetes, peripheral vascular disease, hypercoaguability, and tobacco use are not absolute contraindications to replantation but must be considered.

images Similarly, the surgeon must evaluate for medical conditions that prevent the patient from tolerating the blood volume changes associated with major limb replantation. Revision amputation may be the best choice if the patient has a history of previous trauma or arthritis in the amputated part.

images Ischemia time and method of transport should be evaluated for appropriateness. In the digits, a warm ischemia time of less than 6 hours is desired. In more proximal amputations containing muscle, ischemia time is more critical.

images Cooling the amputated part reduces metabolic acidosis, bacterial growth, and muscle necrosis. Cold ischemia times of up to 12 hours are tolerated for replantation of digits. There are reports of successful replantation of digits with warm ischemia times of 42 hours and cold ischemia times of 96 hours.3,24

images Proper transportation of the amputated part is essential. Never place the part directly on ice. The part should be wrapped in a sterile gauze moistened with Ringer’s lactate or normal saline. The gauze is then placed in a leak-proof plastic bag and the bag is placed on ice (FIG 2). The goal temperature is 4°C.

images Alternatively, the part may be immersed in Ringer’s lactate or normal saline in a plastic bag with the bag then placed on ice.

images The surgeon examines the part and the injured extremity to evaluate suitability for replantation. The number of digits, level of injury, and type of injury are assessed.

images Specifically, the surgeon evaluates the injured parts for the red-line sign and the ribbon sign.

images The red-line sign refers to a red streak of ecchymosis along the lateral border of the digit, which is the result of hemorrhage from avulsed branches of the digital artery after a traction injury (FIG 3).

images The ribbon sign also represents an avulsion injury. Coiling of the artery at the amputation site results from disruption of the vessel wall layers from traction.21 If replantation is attempted, vein grafting is required.

images

FIG 2  The amputated part should be wrapped in a sterile gauze moistened with Ringer’s lactate or normal saline. The gauze is then placed in a leak-proof plastic bag, which is placed on ice. The part should never be placed directly on ice.

images

FIG 3  The red-line sign, which represents an avulsion injury, is seen clinically as a red streak of ecchymosis along the lateral border of the digit. This ecchymosis is the result of hemorrhage from avulsed branches of the digital artery after a traction injury. The ribbon sign, which also represents an avulsion injury, refers to the corkscrew appearance of the digital artery resulting from disruption of the vessel wall layers. When these clinical signs are present, the zone of injury must be bypassed with vein grafts if replantation is attempted.

IMAGING AND OTHER DIAGNOSTIC STUDIES

images When the patient arrives in the emergency department, standard radiographs of the amputated parts and the injured limb are obtained (FIG 4).

images Laboratory evaluations should include a complete blood count, basic metabolic panel, coagulation panel, drug screen, and blood type and crossmatch. Other preoperative tests are ordered as indicated by the patient’s age and comorbidities.

NONOPERATIVE MANAGEMENT

images There is no role for nonoperative management of these injuries.

images Some surgeons advocate performing revision amputations in the emergency department under local anesthesia. It has been our experience that these procedures are best performed in the operating room with appropriate anesthesia, hemostasis, sterile conditions, lighting, and equipment.

images

FIG 4  A. Standard PA radiograph of the injured hand. B. A radiograph of the amputated parts is also obtained by placing the bag containing the parts directly on the x-ray cassette.

SURGICAL MANAGEMENT

images The decision to replant a digit is predicated on the determination that the anticipated function after replantation will be better than that of a revision amputation. This determination is made after careful consideration of the factors influencing the predicted survival of the replanted digit, morbidity to the patient, and functional outcome.

images Specific factors related to the status of the amputated part and the status of the patient include:

images Mechanism of injury (eg, sharp, crush, avulsion)

images Level of amputation

images Ischemia time (warm or cold)

images Health of patient

images Age of patient

images Presence of segmental injury

images Predicted rehabilitation

images Vocation and hobbies

images Informed consent for replantation versus revision amputation must reference the postoperative care differences.

images Patients undergoing revision amputation typically are discharged from the hospital much quicker and have much shorter, less intensive rehabilitation protocols.

images Patients treated by replantation typically require a 5to 7-day hospital course, avoidance of smoking and caffeine, possible blood transfusions, and prolonged rehabilitation. Furthermore, these patients must be advised about the likelihood of cold intolerance.

images The techniques we use for replantation of amputated digits are described in detail in the following sections. The same techniques and sequence of repair are followed for the revascularization of partially amputated parts.

images In partial amputations, not all structures will be injured, so it may be that only some structures require repair. For example, if the dorsal skin and its veins remain intact, the procedure does not require venous anastomosis for outflow.

images Each case should be examined individually, and all structures should be carefully evaluated for injury.

Preoperative Planning

images Broad-spectrum antibiotics and tetanus prophylaxis are administered on presentation in the emergency department.

images The patient, hand, and amputated parts are examined to confirm suitability for possible replantation.

images A urethral catheter should be placed for long procedures.

images Regional anesthesia is preferred due to the autonomic block, which yields increased peripheral vasodilation. Ideally, an indwelling catheter is placed to allow for continuous postoperative pain relief and sympathetic block. General anesthesia is required for children.

images If an attempt at replantation is determined to be appropriate and desired, the parts are brought to the operating room as soon as possible. Initial preparation of the parts can begin while the anesthesia team evaluates the patient.

images The operating room and patient must be kept warm to prevent peripheral vasoconstriction.

images The sequence of repair is as follows:

1. Débridement and identification of structures

2. Bone shortening and fixation

3. Extensor tendon repair

4. Flexor tendon repair

5. Arterial repair

6. Nerve repair

7. Vein repair

8. Skin closure/coverage

Positioning

images The patient is positioned supine on a standard operating room table with a hand table attachment. The table is rotated 90 degrees to allow access for the operating microscope and fluoroscopy.

Approach

images Slightly dorsal midaxial incisions are made on both the radial and ulnar sides of the digits. These incisions allow for rapid identification of both the neurovascular bundles and the dorsal veins. Both the palmar and dorsal flaps can be reflected as needed (FIG 5).

images

FIG 5  Bilateral longitudinal midaxial incisions allow for easy exposure of the neurovascular bundles and dorsal veins.

TECHNIQUES

PREPARATION OF THE AMPUTATED PART

images  A two-team approach is used. One team prepares the amputated part while the other team prepares the patient.

images  The parts should continue to be kept cool until they are reattached. A sterile prep table and a sterile covered icefilled basin are required for preparation of the parts (TECH FIG 1).

images A sterile metal irrigation basin is filled with ice and covered with a sterile adhesive drape.

images A moist sterile towel is placed over the drape as a working surface.

images The basin should be filled such that the ice forms a mound above its rim.

images  The parts are brought to the operating room and cleaned on the sterile prep table with Hibiclens and sterile Ringer’s lactate.

images

TECH FIG 1  A,B. The amputated parts are removed from the bag, and a sterile prep is performed on a separate table. C. A sterile metal irrigation basin is filled with ice and covered with a sterile adhesive drape. Use as much ice as can be placed without disruption of the sterile environment to maximize contact with the amputated parts. D. A sterile surgical towel is then placed over the drape and used as a working surface. E. Nylon sutures placed through the amputated parts are secured to the surgical towel. The amputated parts are now ready for débridement and preparation.

images  A nylon suture is passed through the tip of each amputated part and secured to the towel with a small hemostat.

images  Under loupe magnification, the contaminated skin edges and subcutaneous tissues are débrided.

images  Slightly dorsal midlateral incisions are made on the radial and ulnar sides of the digit. Arteries, nerves, and veins are identified and tagged for later with small hemoclips. The hemoclips should be placed as close to the vessel and nerve ends as possible to avoid damaging the structures.

images  The nerves and vessels are exposed for a length of 1.5 to 2 cm. The veins lie in the subdermal plane and can be identified by elevating the dorsal skin flap. If the veins are difficult to isolate, the surgeon may defer their identification until after the anastomosis of one artery when engorgement makes them more prominent.

images  The flexor tendons are identified, and a 4-0 nonabsorbable braided suture is placed in each tendon in a Tajima fashion. The crossing limb of the Tajima suture should be placed 1.0 to 1.2 cm from the free end of the tendon.

images  The bone is then shortened appropriately. Consideration of the level and geometry of amputation is required. It is necessary to reference the recipient site to match the orientation of the bone ends.

images  In general, 4 to 10 mm of total digit shortening allows for appropriate débridement of nerves and vessels to healthy tissue and subsequent primary repair without tension. Shortening also eases skin coverage of the repair site. The amount of shortening depends partly on the mechanism of injury. Crush injuries typically require more resection than sharp injuries.

images  Two 0.045-inch K-wires are placed longitudinally down the long axis of the bone in a retrograde fashion. The Kwires should exit through the tip of the digit just palmar to the nail. The K-wires are advanced until the tips are showing through the bone so that the amputated digit is now ready for immediate attachment.

images  The parts should continue to be kept cool under ice packs until they are reattached.

Once a vein is located, continue the dissection in the same subdermal plane to identify others. If possible, two veins are repaired for each artery.

images  Flexor tendons are identified, and a Tajima suture is placed in each (TECH FIG 2). If the tendons have retracted proximally, atraumatic retrieval is necessary to avoid inducing spasm or damaging the proximal vessels. If required, a separate proximal incision is made to retrieve the tendons safely.

PREPARATION OF THE STUMP

images  The second surgical team initiates preparation of the injured extremity while the amputated parts are being prepared.

images  Under tourniquet ischemia and loupe magnification, débridement of the skin and subcutaneous tissues is performed.

images  In an identical manner to the amputated parts, the arteries, nerves, and veins are identified, tagged, and exposed through slightly dorsal midlateral incisions. The veins are the most difficult structures to identify on the stump.

images

TECH FIG 2  A. A Tajima-type suture repair is used so that the flexor tendons can be opposed and secured at the ideal time. B,C. The suture is placed in the proximal and distal ends of the tendon. D. The sutures are then tied in the repair site at the appropriate time.

images  After identifying all structures, evaluate the need for grafts. Every attempt should be made to repair all structures primarily. Delayed reconstructions are much more difficult, place the repaired vessels at risk, and subject the patient to additional surgery and rehabilitation.

images  Any amputated parts that are not being replanted should not be discarded, because these are an excellent source for donor grafts.

BONE FIXATION

images Bone shortening has already been performed at the time of débridement. If shortening was limited by the proximity of joints, the use of vein grafts should be entertained at the time of vessel anastomosis. When shortening the bone in a thumb amputation, the resection should be maximized on the amputated part so that if the replant fails, thumb length is maintained.

images Numerous methods of bone fixation are available, including longitudinal K-wires, crossed K-wires, intraosseous wiring, tension band, intramedullary screw, and plate and screws.

images Parallel longitudinal K-wires are quick, easy, and have low nonunion and complication rates.10 When possible, this is my preferred technique (TECH FIG 3AD).

images Crossed K-wires are also relatively quick and easy to use. The drawback to crossed K-wires is potential risk to the neurovascular bundles, either directly or by tethering (TECH FIG 3EH).

images Intraosseous wiring takes more time and exposure to perform, but allows for early range of motion. Drill holes accepting of a 24-gauge wire are placed in a dorsal-to-palmar and radial-to-ulnar orientation at each bone end. Two loops of 24-gauge wire are then passed perpendicular to each other through the analogous drill holes at each bone end and tightened in standard cerclage fashion.

images The tension band technique is a useful option for arthrodesis, because it allows the surgeon to set the desired amount of flexion. Two parallel 0.045-inch Kwires are placed across the fusion site, and a figure-8 loop of 24-gauge wire is used over the dorsum of the finger to complete the construct.

images

TECH FIG 3  A–D. Parallel longitudinal K-wires allow for easy and rapid fixation with low complication rates. (continued)

images

TECH FIG 3  (continued) E–H. In more proximal amputations, longitudinal K-wires may not be possible. Crossed K-wires can be used successfully in these injuries.

images The intramedullary screw is most useful in thumb amputations at the metacarpal level. Removal of this hardware is difficult, so its use should be avoided in highly contaminated wounds where the risk of infection is high.

images Lag screw fixation is appropriate to treat long oblique fractures. However, because most amputations do not result in this fracture pattern, this technique is seldom used in replantation surgery.

images Plate-and-screw fixation is generally not required in digit replantation because nonunion is rare. While it provides rigid fixation, the hardware is bulky, increases tendon adhesions, and requires more time and exposure.

images  Regardless of the method of fixation, the surgeon must constantly evaluate alignment and rotation of the digit in both flexion and extension. The flexed fingertips should point toward the distal pole of the scaphoid.

EXTENSOR TENDON REPAIR

images  After bone stabilization, the extensor mechanism is repaired.

images  In the digit, the tendon is repaired with two horizontal mattress sutures using a 4-0 nonabsorbable suture.

images  It is imperative to repair the entire extensor mechanism. If the amputation is through the proximal phalanx, repair of the lateral bands will optimize functional outcomes.

FLEXOR TENDON REPAIR

images  Because the Tajima sutures have already been placed, they are now ready to be tied in the repair site. The two strands of the repair should be tied simultaneously to achieve a symmetric repair.

images  In certain circumstances, the surgeon may choose to delay tying the sutures until after the microsurgical portion of the case. Specifically, in very proximal amputations, the ability to position the digit in slight hyperextension may facilitate the vessel and nerve repair.

images  Both the FDS and FDP are repaired when feasible. If the amputation is in zone 2 and the tendons are not cleanly cut, repair of only the FDP tendon is reasonable.

images  If the amputation level is distal to the FDS insertion, but proximal to the DIP joint, we typically do not repair the FDP or extensor tendon. We favor arthrodesis of the DIP joint with K-wires and direct rehabilitation toward early active and passive range of motion of the proximal interphalangeal (PIP) joint.

ARTERIAL REPAIR

images  We have found that both digital arteries should be repaired, when feasible, to maximize survival rates.

images  The operating microscope and microsurgical instrument set are used.

images  The most important factor affecting survival is achieving a tension-free anastomosis of normal intima to normal intima (TECH FIG 4AC).

images  Débridement of damaged arteries is performed under the operating microscope. The surgeon must resect until normal intima is identified. The liberal use of vein grafts is advocated for resulting defects.

images  The tourniquet is released to ensure good blood flow from the proximal stumps.

images

TECH FIG 4  A–C. Arterial repair is performed using the operating microscope. A tension-free anastomosis of normal intima to normal intima is essential for survival of the replanted part. D. The vascular approximating clamp should have less than 30 g of closing pressure. Two clamps on a sliding bar allow for tension-free positioning of the vessel ends.

images  Sharply trim the proximal stump with angled Potts scissors and dilate the lumen with jeweler’s forceps or a lacrimal duct dilator.

images  If adequate blood flow is not obtained, evaluate for all reversible causes of vasospasm, including hypotension, hypovolemia, acidosis, pain, or cold. Double check that the tourniquet was deflated.

images  Evaluate the proximal vessel for mechanical constriction.

images  Thoroughly irrigate the lumen with warm heparinized Ringer’s lactate through a 30-gauge blunt-tipped needle on a 10-mL syringe.

images  If vasospasm persists, irrigate the proximal vessel with papaverine solution (diluted 1:20 with sterile normal saline).

images  After appropriate blood flow is established, the proximal and distal stumps are placed within the vascular approximators. Several types of approximating devices are available. We favor two clamps on a sliding bar. The clamps should have less than 30 g of closing pressure and should be limited to no more than 30 minutes of application time due to the potential for vessel damage (TECH FIG 4D).

images  Place a microsurgical background deep to the repair site.

images  A bolus of 3000 to 5000 U of intravenous heparin is given just before the anastomosis. After the bolus, we typically initiate a heparin drip at 1000 U/hr.

images  Repeat inspection of the intima is performed proximally and distally to confirm its integrity. Verify that the anastomosis is tension-free and that no adventitia overhangs the lumen.

images  Appropriately sized monofilament nylon sutures (Table 1) are used, and initial sutures are placed 180 degrees apart.

images  The size of each “bite” should be about one to two times the thickness of the arterial wall.

images  Care must be taken to avoid damaging the intima of the vessel.

images  One limb each of the initial sutures should be cut long for use in manipulating the vessel without directly handling it.

images  Suture the front wall of the artery sequentially between stay sutures.

images  Irrigate the lumen after each suture is tied, and inspect the repair site to confirm that the back wall was not captured.

images  Flip the approximating clamp to expose the back wall and complete the anastomosis.

images  Remove the vessel from the approximating clips and repeat the procedure on the other digital artery.

images

NERVE REPAIR

images  The proximal and distal nerve ends are examined under the operating microscope.

images  The ends are cut sharply with a no. 11 blade against a wooden tongue depressor. The nerve is resected until pouting fascicles are visualized.

images  The fascicles are aligned, and an epineurial repair is performed using two or three 9-0 or 10-0 sutures (TECH FIG 5).

images  If a tension-free repair is not possible, primary nerve grafting is performed. The medial antebrachial cutaneous nerve is the ideal caliber for digital nerves and can be obtained from the ipsilateral extremity. Similarly, any amputated digits that are not candidates for replantation provide an excellent source for grafts.

images

TECH FIG 5  The digital nerve is approximated using an epineurial repair consisting of two or three sutures.

VEIN REPAIR

images  Ideally, a minimum of two veins are repaired for each artery.1,10 The largest veins identified should be repaired.

images  When performing the anastomosis, each “bite” should be about two to three times the thickness of the vein wall.

images  Constant irrigation with heparinized Ringer’s lactate helps to “float” the lumen of the vein open.

images  Due to the low pressure flow, the venous anastomosis can be performed with fewer sutures than are required for the arterial anastomosis (TECH FIG 6).

images  Familiarity with alternatives to venous anastomosis is necessary in the event suitable veins cannot be located.

images  Continuous venous oozing can be encouraged by removal of the nail with subsequent scraping of the matrix. This scraping is performed every 2 hours with a cotton-tipped applicator and is followed by the application of heparin-soaked pledgets.

images  If proximal veins are present but distal veins are not, creation of either an arteriovenous or venouscutaneous fistula may facilitate outflow to reduce congestion. This scenario is most common in very distal amputations just proximal to the nail. An arteriovenous fistula may be created possibly if one artery has been successfully repaired and back-bleeding is present from the other distal artery. This artery can be anastomosed to the proximal vein. Alternatively, a vein graft can be used to create a temporary shunt from the skin of the pulp to the proximal vein.

images  Medicinal leeches (Hirudo medicinalis) can be placed on the engorged part if venous congestion occurs. They should be changed every few hours and should be used for a minimum of 7 days to allow for the establishment of collateral circulation. Although the leeches may fall off after engorgement, they secrete hirudin, a local anticoagulant that keeps the digit bleeding for 8 to 12 hours. While using leech therapy, the patient should be treated with a third-generation cephalosporin as prophylaxis against Aeromonas hydrophilia infection, a symbiotic gram-negative rod in the leech gut.

images

TECH FIG 6  The venous anastomosis is performed with fewer sutures than the arterial repair due to the low pressure flow.

SKIN COVERAGE AND WOUND CLOSURE

images  Before the wound is closed, meticulous hemostasis must be achieved. Even small postoperative hematomas can compress the vascular repairs and result in failure of the replant.

images  Interrupted nylon sutures are used to close the wounds, avoiding constriction of underlying structures. The midlateral incisions can be left open without concern for healing difficulties. If the repaired dorsal veins lack local coverage, a splitor full-thickness graft should be applied.

images  No part of the postoperative dressing should be circumferential. Small strips of petroleum-impregnated gauze are applied to the incisions. A bulky dressing is constructed with a plaster splint extending above the elbow. The tips of all digits must remain exposed, and a temperature probe is taped to the pulp of the replanted digit for monitoring.

images  The limb is elevated in a foam pillow.

images

POSTOPERATIVE CARE

images Usually, the hand is elevated, with the level of elevation adjusted for changes in vascular status. If arterial inflow becomes problematic, the hand is lowered. If venous congestion is present, the hand is raised.

images Color, warmth, turgor, and capillary refill are monitored by the surgeon.

images The patient’s room should be kept warm, preferably above 22° C (72°F). The temperature probe is monitored by the nursing staff, and the surgeon is notified if the digital temperature is less than 30°C or if the temperature drops 2°C over 1 hour.

images The patient is maintained on bed rest for the first 2 or 3 days, and the room is kept dark with minimal stimulation. Visitors are limited to two at a time.

images The patient is restricted from nicotine and caffeine products.

images The intravenous heparin drip is continued at 1000 U/hr. The rate is adjusted for a goal activated partial thromboplastin time (aPTT) of 1.5 times normal. It is maintained for 5 days, then weaned by 100 U/hr until off.

images Dextran 40 is given as a 50-mL bolus and then maintained at a rate of 20 mL/hr while the patient is in the hospital.

images Enteric-coated aspirin (325 mg daily) and dipyridamole (50 mg tid) are initiated and maintained for 6 weeks postoperatively.

images Chlorpromazine (25 mg orally q 8 h) is useful as both an anxiolytic and a peripheral vasodilator. We generally use it for the duration of the patient’s hospital stay.

images Appropriate antibiotics are maintained for 7 days.

images We prefer to leave the operative dressing in place for 7 days to avoid causing vasospasm. Excessive bleeding with formation of a blood cast that would restrict venous outflow should prompt an earlier dressing change.

images Gentle active motion is started on postoperative day 3 within the confines of the splint. Formal hand therapy is initiated after the splint is removed.

OUTCOMES

images A survival rate greater than 80% is expected for replantation surgery.

images Functional outcomes are greatest for replantation of the thumb, proximal hand, and single digit distal to the FDS insertion (FIG 6A–D).8,9,17,20

images Recovery of sensation is correlated with function. As in other peripheral nerve injuries, age is the most important factor for recovery, with better results in younger patients. The average two-point discrimination in replanted thumbs is 11 mm and in fingers is 8 mm.7 These values represent the average recovery for sharp amputation. Crush and avulsion mechanisms result in poorer two-point discrimination.

images

FIG 6  A–D. This patient sustained an amputated thumb, which was successfully replanted with good cosmetic and functional results. (continued)

images

FIG 6  (continued) E–G. Successful replantation of the ring and small fingers resulted in a functional hand capable of holding common objects.

images Range of motion is related to level of amputation. Active PIP joint motion in replantations proximal to the FDS insertion average 35 degrees, whereas replantations distal to the FDS insertion result in 82 degrees of PIP joint motion (FIG 6E–G).10

COMPLICATIONS

Immediate Complications

images Immediate complications affect the survival of the replanted digit and typically relate to the vascular status.

images Arterial insufficiency may result from unrecognized vessel injury away from the anastomosis, which causes thrombosis or vasospasm.

images A check for reversible causes is initiated to ensure that the patient is warm, comfortable, hydrated, and calm.

images Check the dressings to confirm that there is no mechanical constriction.

images Confirm that the patient’s hematocrit is near normal and that all ordered medications are being given appropriately.

images The hand should be lowered to increase inflow, and an intravenous bolus of heparin (3000–5000 U) is given. If the patient has not been anticoagulated or has not achieved therapeutic levels, a regional sympathetic block will aid peripheral vasodilation.

images Vigilant re-examination of color, warmth, turgor, and capillary refill is necessary to decide whether exploration in the operating room is indicated. Revisions after 4 to 6 hours of reduced perfusion seldom result in digit salvage.10

images If venous engorgement occurs postoperatively, elevate the hand and remove constrictive dressings (including sutures that are too tight).

images Consideration for return to the operating room is based on intraoperative findings affecting the possibility of revising the venous anastomosis.

images If this is not possible, leeches or nail removal are used to alleviate venous congestion. These methods typically are used to bridge the first 4 to 6 days until adequate outflow is established.

Long-term Complications

images Long-term complications include pin tract infections, cold intolerance, stiffness, malunion, and nonunion.

images Pin tract infections usually occur more than 4 weeks after surgery. They are easily treated by pin removal and a course of oral antibiotics.

images Cold intolerance is almost universal. (This also is a problem in revision amputations.) Cold intolerance is expected to improve over the first 2 years but it remains debatable whether it completely resolves.3,18

images Digital stiffness is common, because both the flexor and extensor tendons are repaired. Tenolysis should be delayed for at least 3 months post-replantation but has demonstrated good results.12

images Malunion usually results from malalignment at the time of bone fixation. Intraoperatively, rotational alignment is the most difficult to assess. Malunion is more common in proximal amputations, because even slight malalignment at the amputation level is greatly accentuated at the fingertip.

images Nonunion is not common after replantation of the digit. It has been reported in fewer than 10% of digit replantations and rarely requires reoperation.19,20

REFERENCES

1.     Allen DM, Levin LS. Digital replantation including postoperative care. Tech Hand Up Extrem Surg 2002;6:171–177.

2.     Al-Shammari S, Gupta A. Revascularization of the digits and palm. Hand Clin 2001;17:411–417.

3.     Backman C, Nystrom A, Backman C, et al. Arterial spasticity and cold intolerance in relation to time after digital replantation. J Hand Surg Br 1993;18:551–555.

4.     Baek SM, Kim SS. Successful digital replantation after 42 hours of warm ischemia. J Reconstr Microsurg 1992;8:455–458.

5.     Boulas HJ. Amputations of the fingers and hand: indications for replantation. J Am Acad Orthop Surg 1998;6:100–105.

6.     Camacho FJ, Wood MB. Polydigit replantation. Hand Clin 1992;8:409–412.

7.     Glickman LT, MacKinnon SE. Sensory recovery following digital replantation. Microsurgery 1990;11:236–242.

8.     Goldner RD, Howson MP, Nunley JA, et al. One hundred eleven thumb amputations: replantation versus revision. Microsurgery 1990;11:243–250.

9.     Goldner RD, Stevanovic MV, Nunley JA, et al. Digital replantation at the level of the distal interphalangeal joint and the distal phalanx. J Hand Surg Am 1989;14:214–220.

10. Goldner RD, Urbaniak JR. Replantation. In: Green D, Hotchkiss RN, Pederson WC, et al, eds. Green’s Operative Hand Surgery, ed 5. Philadelphia: Elsevier Churchill Livingstone, 2005:1569.

11. Hattori Y, Doi K, Ikeda K, et al. A retrospective study of functional outcomes after successful replantation versus amputation closure for single fingertip amputations. J Hand Surg Am 2006;31:811–818.

12. Jupiter JB, Pess GM, Bour CJ. Results of flexor tendon tenolysis after replantation in the hand. J Hand Surg Am 1989;14:35–44.

13. Lim BH, Tan BK, Peng YP. Digital replantations including fingertip and ring avulsion. Hand Clin 2001;17:419–431.

14. Lucas GL. The pattern of venous drainage of the digits. J Hand Surg Am 1984;9:448–450.

15. Matsuzaki H, Yoshizu T, Maki Y, et al. Functional and cosmetic results of fingertip replantation: Anastomosing only the digital artery. Ann Plast Surg 2004;53:353–359.

16. Ozkan O, Ozgentas HE, Safak T, et al. Unique superiority of microsurgical repair technique with its functional and aesthetic outcomes in ring avulsion injuries. J Plast Reconstr Aesthet Surg 2006;59:451–459.

17. Patradul A, Ngarmukos C, Parkpian V. Major limb replantation: a Thai experience. Ann Acad Med Singapore 1995;24(4 Suppl):82–88.

18. Povlsen B, Nylander G, Nylander E. Cold-induced vasospasm after digital replantation does not improve with time: a 12-year prospective study. J Hand Surg Br 1995;20:237–239.

19. Urbaniak JR, Hayes MG, Bright DS. Management of bone in digital replantation: Free vascularized and composite bone grafts. Clin Orthop 1978;133:184–194.

20. Urbaniak JR, Roth JH, Nunley JA, et al. The results of replantation after amputation of a single finger. J Bone Joint Surg Am 1985; 67A:611–619.

21. Van Beek AL, Kutz JE, Zook EG. Importance of the ribbon sign, indicating unsuitability of the vessel, in replanting a finger. Plast Reconstr Surg 1978;61:32–35.

22. Waikakul S, Sakkarnkosol S, Vanadurongwan V, et al. Results of 1018 digital replantations in 552 patients. Injury 2000;31:33–40.

23. Wang H. Secondary surgery after digital replantation: Its incidence and sequence. Microsurgery 2002;22:57–61.

24. Wei FC, Chang YL, Chen HC, et al. Three successful digital replantations in a patient after 84, 86 and 94 hours of cold ischemia. Plast Reconstr Surg 1988;82:346–350.



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