Introduction
Replantation surgery has now entered its 6th decade after the first successful limb replantation reported by Malt in 1964 and the first thumb replantation in 1968 by Komatsu and Tamai. Developments in microsurgery have made the salvage of amputated digits and hands via replantation and revascularization ordinary procedures in many centers throughout the world. With improved techniques, advanced knowledge, and surgeons’ growing experience, success rates reach 80% to 90%. Moreover, these successes are no longer measured by survival alone but by improved functional recovery.
Key anatomical points
Larger veins and venous networks are on the dorsal aspect of the digits and hand. We commonly use veins on the dorsal aspect of the digits and hand for venous anastomosis during replantation. The proper palmar digital arteries travel along the sides of the phalanges, each artery just dorsal and slightly lateral to its corresponding proper digital nerve. There are no continuous or consistent venae comitantes associated with the proper or common digital arteries. Even for replantation at the wrist or forearm, subcutaneous veins are commonly used. Distal to the distal interphalangeal (DIP) joint, proper digital arteries on both sides of a finger form the distal arterial arch, which provides three to four branches to supply the distal fingertip. These branches are used for arterial anastomoses distal to the DIP joint. Proper digital nerves bifurcate to small branches traveling distal to the DIP joint; these branches are too small to be repaired during very distal replantation.
Indication and contraindications
Advances in microsurgical techniques have extended the indications for replantation, and, hypothetically, all amputations from the fingertips to the upper arm can be considered for replantation. The careful selection of patients to be treated remains of primary importance, even for Asian surgeons, who perform replantation surgery using an approach quite different than that of American and European surgeons. ,
The importance of the thumb and the need of at least three digits for hand function makes the attempt of replantation almost mandatory when there has been an amputation of more than two fingers. Transmetacarpal, wrist, and middle-to-distal forearm amputations offer good to excellent functional results, and replantation at these levels is strongly indicated. In children, regardless of the level of injury, replantation remains a priority. Therefore, undisputed indications for digital replantation ( Table 24.1 ) are (1) thumb amputation proximal to the interphalangeal (IP) joint, (2) amputation of fingers proximal to the insertion of the flexor digitorum superficialis (FDS) tendon, (3) amputation of multiple digits, and (4) amputation through the palm or wrist. Patients with the above indications should have rather tidy amputations without avulsion of tendons or nerves or extensive skin loss.
| Absolute Indications | Relative Indications | Controversial Indications | Absolute Contraindications |
|---|---|---|---|
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|
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Relative indications ( Table 24.1 ) are (1) amputation of a single finger distal to FDS tendon insertion (including amputation distal to the DIP joint), (2) degloved skin of hands and fingers, (3) ring avulsion injury, (4) elderly patients, and (5) extensive loss of tissue with amputation at the wrist or hand level. The age of 70 years is considered the demographic limit for replantation. With the increase in average lifespan, the age limit must be individually evaluated based on the general health of the patient.
More controversial replantation indications are (1) amputation of a single digit proximal to FDS tendon insertion, (2) multiple segmental injuries of the amputated part, (3) crush and avulsion injuries, (4) self-inflicted injuries, and (5) heavy smokers. Replantation for these patients should be subject to the surgeon’s preference and the patient’s choice. The patient must be able to tolerate a long surgical procedure; an unstable patient with severe or multiple injuries needs to be stabilized to minimize anesthesiologic and surgical risks. Life-threatening injuries and systemic illness are contraindications for replantation.
Amputation of a single non-thumb digit is a controversial indication for replantation. As this amputation does not affect essential function of the hand, its indications vary greatly around the world. Patients in various areas may also have different preferences related to replantation of a single finger.
Time limit and preservation of amputated parts
Ischemic time is critical for amputated parts containing muscle, and the warm ischemic time must be no longer than 6 hours. The ischemic time for amputated digits is not as critical as that for amputated forearms and hands, which contain muscle; and ischemic times can be extended with cold preservation.
The ischemic time is one of the main aspects influencing replantation success. Different tissue types have different tolerances to anoxia depending on the tissue’s metabolic demands. The ischemic time limit is therefore different for amputations of parts containing muscle; this is the most important difference between macro (major part) and micro replantation. For replantation of major parts (amputation proximal to digits), the warm ischemic time (20–25°C) should not exceed 4 to 6 hours, while the cold ischemic time (0 to -4°C) should not be longer than 6 to 8 hours. A longer period would risk systemic damage caused by the anaerobic catabolites and oxygen free radicals from muscles entering the circulation. The tolerance of composite tissue to ischemia depends on the amount of skeletal muscle it contains. For cases of macro replantation presenting with more than 8 to 10 hours of cold ischemic time, it is recommended to remove part of the muscle component, especially the FDS. However, good results have been reported for macro replantation despite long ischemic times.
The ischemic tolerance of amputated digits is fairly high since they do not contain muscle. The warm ischemic time should not exceed 12 hours, and the cold ischemic time should not exceed 24 hours. The acceptable ischemic time for digits remains controversial: Numerous papers have reported successful replantation of digits after prolonged ischemia, both warm and cold. One of the authors (SHW) described six cases of successful digital replantation despite a warm ischemic time between 25 and 72 hours.
The longest tolerable ischemic time remains unknown, especially for digital amputations. Proper care and transport of the patient and the amputated portion(s) of their limb are essential. The amputated part is wrapped in a moist gauze sponge , placed in a sterile and sealed container, and then placed in an ice bath. After an initial rapid cooling of the parts, maintaining them at 10°C can prolong conservation. Placing the amputated part in cold saline is not harmful, but this method tends to macerate the skin after a few hours. Dry ice should be avoided, as it can cause the part to freeze. Devascularized parts that remain attached to the patient should also be packed in ice and should not be detached until careful evaluation; in fact, there may be continuity not only of the skin but also of the tendons and veins, etc. In this case, a splint that immobilizes the limb is a simple solution.
Initial clinical examination and decision-making
Upon arrival at the hospital, the patient should be warmed and immediately monitored, and intravenous solution should be administered. X-rays must be done on both the amputated part and the limb. It is important to collect the patient’s history, the limb dominance, occupation, any preexisting pathologies, and, above all, the traumatic mechanism involved. Any information as to the cause of injury may be of great value. When possible, the patient should be fully informed and participate in the decision. Injury type is a predictor of replantation success: Sharp guillotine-type injuries represent the best conditions, while crush injuries frequently seen in industrial accidents represent the worst. In a severely mutilated limb with extensive skin, muscle, bone, and nerve damage, replantation is not indicated. Severe crush and avulsion injuries have a high risk of failure; even if replantation is possible, the functional outcome is often poor.
During preparation for surgery, the amputated parts should be examined with the aid of loupe or microscope magnification; unusable tissues should be debrided, and arterial and venous vessels that can be used for anastomoses should be identified. The vessels must be examined carefully. It is advisable to suture a microvascular clip or tag to the available vessels so that they can be found later during surgery ( Fig. 24.1 ). If veins are not identified, particularly in very distal amputations, they will be more easily identified after completion of arterial anastomoses. The nerves can be tagged with 6-0 nylon stitches at their ends. This preparatory time is essential, regardless of the level of amputation, especially for multi-digit amputations. A corkscrew appearance of an artery indicates that strong avulsion force was applied to the finger ( Fig. 24.2 ), and this damaged segment of the artery should be removed and replaced with a vein graft. The tendon and bone should be debrided, and Kirschner (K) wires are frequently used, placed retrograde into the amputated digit.
Better functionality can be obtained by replanting the least-damaged finger, sometimes in a different position than the original. Restoration of a thumb takes priority over that of other digits. For a multifinger amputation, the spare parts from an irreversibly damaged finger can serve as donor tissues to supplement the reconstruction of other digits (a finger bank). ,
For all digital replantations, the first step is to wash the structures and identify the important elements for suture: arteries, veins, nerves, and tendons. Bone exposure is inspected; with the help of fluoroscopy, the decision is made to fix or shorten the bone or, if there is joint damage, to perform arthrodesis. Bone shortening is kept to a minimum, and arthrodesis is an accepted procedure for amputation near the IP or metacarpophalangeal (MP) joints.
Surgical settings
A two-team approach is the ideal way to manage replantation. In macro replantation surgery, unless the amputation is very proximal (arm and/or forearm), we prefer to start, in agreement with the anesthetist, with an axillary block and then subsequently add general anesthesia if the surgical procedure is prolonged and the awake patient becomes uncomfortable.
Methods, sequences, and keys of surgery in each area
Very distal digital replantation
Very distal digital replantation is defined as replantation distal to the DIP joint. Ishikawa zoning is commonly used for further classification of amputation in this site ( Fig. 24.3 ). Typically, four subzones are assigned: subzones 1 and 2 are distal and include a nail injury, and subzones 3 and 4 are more proximal, between the nail and the DIP joint. Since the fingertip is defined as the portion of the digit distal to the insertion of the FDS tendon, a very distal digital replantation describes one at the distal part of the fingertip, where proper digital arteries end and only the arterial branches from the transverse digital arch supply these distal tissues.
If the surgeons are successful, this replantation may have a high incidence of success with good functional and cosmetic results. This raises the question whether a very distal digital amputation should be considered a relative indication for replantation or an ordinary indication in some patient populations. For young adults, teenagers, individuals concerned with the appearance of their hands, and others for whom full-length restoration is advantageous (i.e., musicians), this can be considered an ordinary indication. Direct suturing of the tip distal to the DIP joint without performing vascular anastomosis has about a 50% chance of survival in young children and is therefore commonly performed for such cases.
Replantation distal to the FDS tendon insertion (in Zone I of flexor tendons) (see Fig. 24.3 ), i.e., fingertip replantation, is already a relative indication. Therefore, injuries at this level remain an indication when the surgeon is capable and the patient strongly wishes to have the part replanted. In the authors’ units, replantations in Ishikawa Zones 3 and 4 are regularly done in adults when the cut is tidy and the patient requests it.
The first step is debridement of both the amputated tip and the proximal stump. Arterial spurting from the proximal stump should be identified. In this process, dissection of the artery in the amputated parts is not recommended because it greatly disturbs the small operative field. Trimming and shortening the bone and retrograde fixation of the distal phalanx are performed with one or two longitudinal intramedullary K-wires. The artery in the tip can be easily found mirroring the location of the pulsating artery on the proximal stump. The diameter of these three or more longitudinal branches from the distal transverse palmar arch of the finger average 0.6 ± 0.1 mm in diameter and are suitable for anastomosis. Four or five stitches with 10-0 nylon suture are used without use of a clamp because of the restricted space and exposure. The central artery is the largest terminal branch in Ishikawa Zone 2 ( Fig. 24.4 ). When more arterial length is required, reversing the distal transverse palmar arch is an option. A vein graft taken from near the proximal interphalangeal (PIP) joint crease is another option.
Finding a suitable vein for repair is challenging, and venous insufficiency is the most common cause of replantation failure. The digital veins distal to the DIP joint tend to be larger on the palmar than the dorsal aspect. At the level of the eponychium, 63% of fingers have a vein 0.8 mm or larger. The volar vein in the finger pulp can be used for venous anastomosis (see Fig. 24.4 ). The distal venous arch can be reliably found lateral to the nail fold and can also be used for anastomosis ( Fig. 24.5 , Box 24.1 ). When veins distal to the nail fold are too small, one of the following methods can be used: (1) Making a “fish-mouth” incision in the finger pulp to allow continuous bleeding, (2) removing the nail plate, or (3) using medical leeches. In addition, continuous dropping of heparinized saline to an incision site (allowing for delayed venous repair) may be considered. When leeches ( Hirudo medicinalis) are used , Aeromonas hydrophila , a bacterium in the leech’s gastrointestinal tract, can cause infection, and prophylaxis with fluoroquinolones is recommended.
- 1.
A single K-wire fixation through the distal interphalangeal (DIP) joint is recommended.
- 2.
Connect arteries first. Venous connection is not as important.
- 3.
Use a volar or dorsal vein, make a fish-mouth incision, or use a medicinal leech for venous drainage.
- 4.
Repair of the digital nerves may not be possible. Try to connect if the replant is around the DIP joint, but this is likely not possible or necessary for more distal injuries.
- 5.
Superior surgical proficiency is needed, and outcomes (tip sensation) are not necessarily better than those achieved repairing the stump; as such, this is a relative indication.
Single digital replantation
Views on whether a single finger should be replanted differ greatly by region. , In many western countries, surgeons believe that replantation of a single finger amputated proximal to the FDS tendon insertion should not be performed (with the exception of children), as finger flexion is generally poor. However, in many Asian countries, a single finger amputated proximal to the FDS tendon insertion is a common indication for replantation; this is because this sort of amputation constitutes a majority of digital amputations, and replantation surgery is fairly straightforward. Attempting such a replantation is almost expected for patients in Asian countries. The desire for aesthetics versus function will dictate the treatment decision.
The functional result of a single finger replantation is correlated to the level of amputation. When a finger is amputated distal to the FDS tendon insertion, the uninvolved PIP joint can regain an acceptable range of motion after replantation. If the level of amputation is proximal to the FDS tendon insertion, some surgeons advocate revision amputation because of poor digital function, whereas others have shown good functional outcomes. ,
Ring avulsion injuries continue to be a matter of discussion, particularly those with complete degloving. , In our experience, it is important to explain to the patient in detail that this type of injury does not always result in good functionality. The patients may still request replantation. Often, young patients insistently ask for replantation despite being given details on the possibility of poor functional results.
Replantation of a single finger proximal to the FDS tendon insertion represents a technically straightforward procedure ( Fig. 24.6 ). We believe that it is indicated in some or most circumstances, depending on the patient’s needs and where they live. Amputations at this level should not be routinely considered a contraindication to replantation; the choice should instead be based on the patient’s age, sex, and work activities. We agree with the view of the Buncke Clinic that the index finger, even if it does not have complete motility, may not interfere with the functionality of the hand , (see Fig. 24.6 ). However, a replanted ring finger, if it is stiff, can interfere with general hand function. A complete ring degloving injury must also be carefully evaluated, as the result may often be acceptable despite severe damage ( Fig. 24.7 ). In all cases, the severity of PIP joint damage must be assessed and weighed along with the type of injury and the patient’s age, sex, and work activity.
Common technical keys for single- or multi-digit replantations
Debridement to convert the digital amputation to a clean wound is critical for successful replantation ( Box 24.2 ). During debridement, all unhealthy and contaminated tissue should be excised, and the vessels and nerves should be carefully protected and evaluated. Midlateral or volar and dorsal oblique incisions can be used to expose the vessels and nerves. Our preferred methods include a single longitudinal K-wire or crisscrossing K-wires. Simple bone fixation using a longitudinal K-wire is the preferred choice of one author (CC). Plate fixation is not recommended. Simple and fast fixation should be chosen for multi-digit replantations. A longitudinal K-wire necessitates traversing the DIP joint or even the PIP joint, thus preventing early mobilization, but it is the simplest and fastest way. By fixing the PIP joint in a relatively straight position, finger extension lag is reduced. If the amputation is at the proximal phalanx level, the K-wire is placed through the MP joint in slight flexion. (Some prefer to have the MP joint in extension.)
- 1.
Thorough debridement of all non-viable tissues.
- 2.
Bone fixation with a simple method to save time.
- 3.
Reestablish arterial flow first to find veins more easily.
- 4.
Venous grafting is often necessary for an arterial defect; venous defects are not common, as the veins can be dissected and rerouted easily.
- 5.
Digital nerve repair is always performed; an auto- or allograft is used for a defect.
- 6.
Extensor tendons must be repaired; this can be done immediately after bone fixation to provide stability for arterial anastomosis.
- 7.
Flexor tendon repairs in the digits are highly recommended. For retracted flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) tendons, separate incisions in the palm are preferred. A strong suture repair technique must be used.
Bone shortening (usually 0.5–1 cm) is necessary to achieve primary vessel and nerve coaptation and, more importantly, for skin closure. For a circumferential skin defect, sufficient bone shortening to achieve skin closure is reasonable; however, if the soft tissue defect exists on only one side, flap or skin substitute coverage is recommended.
If flexor tendon repair will take a long time, vascular anastomosis can be performed first. Because repair of extensor tendons provides better stability of the reattached digit and does not take long, this should precede venous anastomoses. Only the flexor digitorum profundus (FDP) tendon is repaired. Suture techniques vary, but we suggest the double Kessler or M-Tang techniques. The extensor tendons can also be repaired after flexor tendon repair. Because extension lag often occurs after replanting the proximal or middle finger, the finger is usually held in full extension for suturing of the extensor tendons. Multiple figure-of-8 sutures are preferred in extensor tendons.
It is controversial whether the arteries or veins should first be repaired. We favor repair of the arteries before veins, especially in replantation of a fingertip, a view shared with other teams. After revascularizing the amputated part, the veins, now filled with blood, are easier to identify. Moreover, the ischemic time will be decreased. Repair of a single proper digital artery is the common practice. Both digital arteries should be repaired, if possible, to increase the incidence of success and, perhaps more importantly, to prevent cold intolerance of the digit if the patient lives in a cold region. After anastomosing the arteries, one or two proper palmar digital nerves are repaired. In an avulsion amputation, the digital nerves are usually avulsed proximally, which results in long and tapered distal nerve stumps and a segmental defect of digital nerves; as such, primary or secondary nerve grafts are usually needed.
It is a common practice that two veins are repaired for each digit. However, the number is not necessarily important because a large vein is more efficient than several small veins, and most venous crises are caused by compression or kinking of the veins. It is critical to avoid kinking the veins with skin closure. Kinking is usually a result of the veins being too loose, so it is important to anastomose the veins under slight tension. The vessels should be covered with healthy skin without tension. If the skin cannot be closed without tension, a skin graft or skin substitute, even on the surface of vessels, is an alternative solution to flap transfer ( Box 24.3 ). If a vein repair is inadequate, a venous or flag flap from an adjacent finger can be used ( Box 24.3 ).
- 1.
For a relatively small defect, skin substitute coverage is recommended.
- 2.
A free or pedicled flap is recommended for a larger defect. A free venous flap is often used as a solution.
- 3.
A soft tissue defect with vascular defects can be managed through a free flow-through flap to the digit or hand or transfer of a pedicled flap from a neighboring digit.
- 4.
Venous flaps from the forearm are often used and can be of particular value for connecting an artery or a vein and to facilitate soft-tissue coverage.
After vascular repair and before releasing the microvascular clamps, a heparin bolus of 50 to 100 U/kg is given intravenously. Dextran 40 can also be administered at a dose of 0.4 mL/kg per hour during the operation. In some units (CC), rapid intravenous infusion of 1000 mL of dextran 40 just after start of the surgery (before vascular anastomosis) is preferred.
The digital nerves should always be repaired, if possible. If there is a defect, an allograft or autograft is indicated at the time of replantation. Some surgeons repair both digital nerves, but others repair or reconstruct only one proper digital nerve with less severe crush injury or avulsion. Cross-innervation from the repaired digital nerve may happen over time. Tables 24.2 and 24.3 summarize the recommendations of the lead author (RA) on anticoagulation and antibiotics, etc.
| Clean-Cut Injury Revascularization with Surgical Time <5 Hours | Crush, Severe Soft Tissue, Degloving Injuries Revascularization with Surgical Time >5 Hours | ||
|---|---|---|---|
| ANTIBIOTIC PROPHYLAXIS |
| ANTIBIOTIC PROPHYLAXIS |
|
| HYDRATION | Colloids and crystalloids ((CF) heart rate, pressure, diuresis, and hematocrit (HT) monitoring) | HYDRATION | Colloids and crystalloids (CF, pressure, diuresis, and HT monitoring) |
| ANTITHROMBOTIC PROPHYLAXIS |
| ANTITHROMBOTIC PROPHYLAXIS |
|
| ANTIINFLAMMATORY THERAPY | Ketoprofen fl in 250 mL of saline solution two times a day | ANTIINFLAMMATORY THERAPY | Ketoprofen fl in 250 mL of saline solution two times a day |
| ANTALGIC THERAPY |
| ANTALGIC THERAPY |
|
| GASTROPROTECTION | Omeprazole cp 30 mg | GASTROPROTECTION | Omeprazole cp 30 mg |
| HEPARIN SODIUM in the operating room | 40 IU/kg when clamp is released | ||
| SODIUM HEPARIN in the ward | 400 IU/kg in 500 mL saline solution, speed 10 mL/hour for 48 hours, PT and PTT monitoring every 6 hours for 48 hours | ||
| Clean-Cut Injury Revascularization with Surgical Time <5 Hours | Crush, Severe Soft Tissue, Degloving Injuries with Surgical Time >5 Hours | ||
|---|---|---|---|
| ANTIBIOTIC PROPHYLAXIS |
| ANTIBIOTIC PROPHYLAXIS |
|
| HYDRATION | Colloids and crystalloids (CF, pressure, diuresis, and HT monitoring) | HYDRATION | Colloids and crystalloids (CF, pressure, diuresis, and HT monitoring) |
| ANTITHROMBOTIC PROPHYLAXIS |
| ANTITHROMBOTIC PROPHYLAXIS |
|
| ANTALGIC THERAPY | Paracetamol + codeine: Pediatric suppositories 2–3 × day | ANTALGIC THERAPY | Paracetamol + codeine: Pediatric suppositories 2–3 × day |
| HEPARIN SODIUM in the operating room | 40 IU/kg when clamp is released | ||
| SODIUM HEPARIN in the ward |
| ||
Multi-digit replantation
It is widely recognized that, although more time consuming, replantation is indicated for multi-digit amputation because of the significant aesthetic and functional loss that would otherwise occur. However, the success rate of replantation varies markedly depending on the mechanism of injury, amputation level, general condition of the patient, and, most importantly, skill of the surgeon.
The technical keys and sequelae of multi-digit replantation are the same as those of single-digit replantation, and the surgery can proceed either digit-by-digit or structure-by-structure ( Fig. 24.8 ). Two surgical teams can simultaneously prepare the proximal stumps and the amputated digits to decrease surgical time and surgeon fatigue.
Thumb replantation
The thumb is crucial for grasping and prehension, and it is responsible for 40% of hand function. It is the most important digit. Given its importance, thumb amputation is an absolute indication for replantation, notwithstanding the type and level of amputation. It is therefore not surprising that thumbs are replanted more frequently than the other digits. , Thumb degloving and crush injuries have a higher failure rate than sharp injuries. , Moreover, replantation of these injuries is technically challenging, and venous grafting is more often necessary.
K-wires are best for skeletal fixation of the replanted thumb ( Fig. 24.9 ). , The next steps are to repair the extensor and flexor tendons. If there is a defect in the extensor tendon, a palmaris longus tendon graft is indicated. Tenolysis may be necessary at a later stage. If repair of the flexor pollicis longus (FPL) is not possible at time of thumb replantation, transfer of the FDS tendon from the ring finger can be completed later.
Arterial anastomosis is then performed. The ulnar digital artery, if not severely damaged, is chosen because it is dominant and more reliable for anastomosis. The princeps pollicis artery can provide sufficient blood flow from the dorsum if no digital arteries are available. At least two dorsal veins are repaired. With avulsion and degloving injuries for which direct arterial anastomosis is not possible, a vein graft harvested from the forearm or wrist or an arterial transfer from an adjacent digit may be necessary ( Fig. 24.10 ). The digital nerves are next repaired using epineural sutures. It is not always possible to reconstruct both digital nerves. Restoration of proper sensation for pinch is mandatory, so the ulnar digital nerve should take priority.
If there is a nerve defect, we prefer transfer of the contralateral proximal nerve of the thumb over nerve grafting. If a nerve graft is needed, we use a branch of the medial antebrachial cutaneous nerve, the terminal branch of the posterior interosseous nerve, or, more recently, an allograft. Skin closure is the last step, but when a soft-tissue defect is evident as a consequence of crush or degloving injuries, either a flap or skin substitute is used.
A soft-tissue defect often presents with amputations through the base of the thumb, causing a defect in the first web, on the radial dorsal side of the hand, or both. Staged reconstruction is planned, depending on multiple factors: Severe contamination, poor patient condition, and unstable vascularization of the remaining tissues. If a staged surgery is planned, the wound can be temporarily covered with a dressing. Relook surgery should be performed within 48 to 72 hours, and an appropriate flap should be selected for definitive coverage.
Transmetacarpal replantation
The replantation requirements for metacarpals differ from those for digits, although the sequence is similar. Unlike digital replantation, a plate can sometimes be used for bone fixation, but a K-wire remains the main method because it saves time. The extensor and flexor tendons are repaired next. If possible, both FDP and FDS tendons are repaired.
The vessel anastomosis differs from that of a single- or multi-digital replantation. At different amputation levels, different arterial anastomosis patterns are needed. The proximal arterial stumps can be the common palmar digital arteries, the palmar metacarpal arteries, or the proper digital arteries. The distal arterial stumps can be the common palmar digital arteries, the palmar metacarpal arteries, the superficial or deep palmar arch, or the ulnar or radial arteries. No matter the scenario, the surgeon should make sure at least one proper digital artery is connected with a proximal blood supply for each finger. If there are extensive segmental defects, a vein graft with multiple branches can be used to bridge the arterial defects of the ulnar or radial artery to multiple common or proper digital arteries ( Fig. 24.11 ). End-to-side anastomosis is appropriate in some cases.
