Survival rates of digital replantation vary in different regions and countries, and Asian surgeons see more challenging cases and have developed some unique methods. Replantation of multiple digits in one or both hands can follow a structure-by-structure method or a digit-by-digit method. For replanting all 10 digits, 3 or 4 teams should be organized. Flow-through flaps, often venous flaps, can be taken from the distal forearm or lower extremity to repair defects of soft tissues and arteries. A pedicled digital artery flap from the adjacent digit can also repair tissue defects and supply blood to the replanted digit.
Key points
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Survival rates of digital replantation vary in different regions and countries, and Asian surgeons see more challenging cases and have developed some unique methods.
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Replantation of multiple digits in one or both hands can follow a structure-by-structure method or a digit-by-digit method. For replanting all 10 digits, 3 or 4 teams should be organized.
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Flow-through flaps, often venous flaps, can be taken from the distal forearm or lower extremity to repair defects of soft tissues and arteries. A pedicled digital artery flap from the adjacent digit can also repair tissue defects and supply blood to the replanted digit.
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Replanting a multilevel severed digit, a digit in a newborn or young child, or a digit amputated distal to the distal interphalangeal joint is challenging, but attempts are routinely made in Asian hospitals. A dry replantation technique can be used in a multilevel severed digit, which reduces surgical time.
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Local anesthesia can be used for digital replantation; local anesthesia with epinephrine for digital replantation has been used in selected cases.
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A few extremely difficult digital replantations illustrate how surgeons have challenged themselves in pushing the limits of microsurgery in salvaging amputated digits.
Introduction
The early development of microsurgical techniques was built largely upon attempts and refinements of replanting the arm, hand, or digits. Half a century later, replantation techniques are mature, but globally variations or differences are seen in indications for deciding whether to pursue replantation and difficulties that microsurgeons would like to address. This review offers an analysis and global view on indications, current practices, and various other considerations about digital replantation and presents some of the most difficult and challenging cases to illustrate some of the technical triumphs of microsurgery (not necessarily functional triumphs).
To prepare this article, the lead author invited a panel of distinguished experts on replantation to join him in assembling materials: J.B.T. provided views of current indications, views, and collected success rates of digital replantation from colleagues or reports from different regions of the world, especially North America and Asia, and summarized the materials from the panelists; Z.T.W. collected from Chinese colleagues some of the most unusual and challenging digital replants; J.C. summarized reports on 10-digit replantation from the Chinese literature and presented his cases of digital replantation; and J.W. reported on the approach to wide-awake digital replantation in selected patients. This collective effort was intended to offer a global update on this common and yet often challenging area of microsurgery.
Introduction
The early development of microsurgical techniques was built largely upon attempts and refinements of replanting the arm, hand, or digits. Half a century later, replantation techniques are mature, but globally variations or differences are seen in indications for deciding whether to pursue replantation and difficulties that microsurgeons would like to address. This review offers an analysis and global view on indications, current practices, and various other considerations about digital replantation and presents some of the most difficult and challenging cases to illustrate some of the technical triumphs of microsurgery (not necessarily functional triumphs).
To prepare this article, the lead author invited a panel of distinguished experts on replantation to join him in assembling materials: J.B.T. provided views of current indications, views, and collected success rates of digital replantation from colleagues or reports from different regions of the world, especially North America and Asia, and summarized the materials from the panelists; Z.T.W. collected from Chinese colleagues some of the most unusual and challenging digital replants; J.C. summarized reports on 10-digit replantation from the Chinese literature and presented his cases of digital replantation; and J.W. reported on the approach to wide-awake digital replantation in selected patients. This collective effort was intended to offer a global update on this common and yet often challenging area of microsurgery.
Digital replantation: whether to undertake and how much effort to expend?
Replantation of a clean-cut amputation in the proximal half of a single digit is a well-established procedure. The indications are well described, and the essential methods are straightforward, without fundamental differences across regions. There are established principles for more complex and difficult amputations. However, in real-world practice, surgeons in different regions or different units of a given region or country execute these well-documented principles differently and are strongly affected by patients’ desires and surgeons’ skills, in deciding whether or how to replant. What the authors have learned in collecting materials for this article is striking. The patients’ attitudes and surgeons’ efforts are so diverse that surgeons in one country may actually have difficulty imagining what decisions and procedures are like in other countries:
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Most individuals who have an amputated digit would wish for the digit to be replanted. However, when only a single digit was amputated but local tissue conditions are unfavorable and injuries are somewhat complex, European people and Americans of European heritage appear more easily accepting of not having a replantation or accepting ray amputation. If similarly complex injuries occurred in an Asian patient, the patient is usually more eager to have the digit replanted and much less willing to accept surgery to terminalize or ray amputation. Consequently, hand surgeons in the East tend to attempt much more complex replantation.
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Most contraindications in textbooks are not real-world contraindications in the practice of many surgeons in the East. Often, the only contraindications in their practice are poor general conditions of the body and severe crush to the distal part of the digit. Replantation of distal fingertips, or in a very young child, or of amputation at 2 levels of a digit, or of 3 or more digits of one hand, is common. Eastern surgeons frequently challenge their own replantation capability, and some become very proficient at replantation as a result of frequently having to push the technical limits of microsurgery upon the request of patients. Many western surgeons would not attempt replantation given the above conditions.
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The survival rate of finger replantation in the United States is currently 61%, and thumb replants have a survival rate of 74%. Replantation in the United States is performed in all academic medical centers and some major regional hospitals, with well-established microsurgical centers seeing higher-than-average survival rates. In the United Kingdom, replantation success can vary from 20% to 70% depending on the centers and the seniority of surgeon performing the procedure. In eastern Asian countries such as China, Japan, and Korea, the survival rate of digital replantation is generally greater than 70% to 80%. Replantation in China is often performed in midlevel local hospitals (eg, county hospitals may have excellent microsurgical teams), with replant survival rates equal to those in academic centers. In the East, replantation survival rates of 60% to 70% are considered low.
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Improved health and safety standards in the United Kingdom have significantly reduced the number of cases being performed. For example, 20 years ago, surgeons in Chelmsford performed 46 cases over a 2-year period, and more recently, only 25 cases were performed in over a 5-year period with no change in indication. The industrial environments are the primary source of amputated digits in the East; hence, the frequency of injury in general is far greater than in the Americas and Europe. It is often seen that, in a midlevel hospital (eg, a county hospital) in China, surgeons handle 2 to 3 digital replants each month and replant more than 30 digits a year; some larger centers perform replantations almost every day. In contrast, most academic medical centers in the United States have only 1 or 2 digital replantation surgeries in a month, and one hand surgeon may only replant 1 or 2 digits each year. Consequently, practice volumes and the experience of the surgeons are dramatically different, although they all are microsurgeons or are microsurgery trained. In the United States, high-volume hospitals are defined as having more than 20 replants per year, and high-volume surgeons are those who perform more than 5 replants a year. For a Chinese surgeon, high volume would mean at least 20 replants per year.
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Microsurgical operation room settings, microsurgical instruments, and sutures in the West and the East are very similar.
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The quality of assistant surgeons and the nursing team varies considerably among replant surgerical centers. For example, in most hospitals in the United States—except in well-established centers for microsurgery—because assistants to the attending surgeon who performs replantation do not have ample exposure to replantation, responsibility rests heavily or solely on the attending surgeon. In the East, commonly 2 surgeons with microsurgical skills—one with extensive experience and another similar or less experienced—work together on the case, including replantation, and the nurses are more frequently on a replantation surgical team. In Europe, theater assistants for microsurgery require specific qualifications beyond a basic theater nurse before they can assist in operations. Therefore, the availably team to assist in microsurgery in Europe is significantly diluted.
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Restrictions in working hours are different in different regions. The European Union working time directive is restrictive on working hours, which means junior trainees have less exposure to these emergency operations or are not required to train for the totality of the operation, providing them with even less exposure and experience to these cases. In contrast, such restriction does not exist in Asia. In the emergency operative settings, the trainees in the United States have no working hour restriction.
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In any regions or countries, in well-established and busy microsurgical centers, postoperative care nurses are always experienced. Because of a great number of such busy centers and popularization of microsurgery into midlevel hospitals in China, postoperatively patients are monitored by nurses especially experienced in microsurgical cases with experience in judging and recording digital circulation. Major centers have independent hand or microsurgery wards with a hand or microsurgical nurse team. A 2 weeks’ stay in hospital after surgery is common in Japan, Korea, and China. In contrast, the patient is discharged dramatically sooner in the United States.
In recent years, it has been suggested that decentralization in performing replantation might be a cause of the decline in survival rates of the replants in the United States over the past 10 years. Between 2002 and 2005, the survival rates for thumb and finger replants reached a peak of 83% and 69%, respectively, considered the result of centralization. In well-established centers in the United States, surgeons perform more difficult replantation. In the general hospital settings, residents and postoperative monitoring expertise are not as vigorous as in large microsurgical centers, staff are not sufficiently trained for efficient replantation surgery or aftercare. Surgeons are not prepared for extremely challenging cases.
Attitudes of patients regarding integrity of digits of the hand are different. Several publications have highlighted such differences between the United States and Japan, and Japanese surgeons preferred replantation despite agreeing that functional outcomes were suboptimal, which be because of Japanese cultural beliefs. No studies have yet compared China to the United States or Japan. Nevertheless, Chinese society does not associate loss of a finger with gang membership, as is the case in Japan. From the authors’ experience with patients in China and the United States, Chinese patients have more difficulty accepting not having replantation or undergoing ray amputation.
Regarding prevalence of training, not many orthopedic-trained hand surgeons in the West perform microsurgery regularly and most microsurgeons are plastic surgeons, whereas in the East, a significant number of hand surgeons from orthopedic backgrounds would be well versed in microsurgery. In Europe, the availability of severe limb salvage expertise is patchy. In the United Kingdom, major trauma centers try to address this need. However, not all plastic surgery centers are directly available at major trauma centers. In Germany, a severe hand surgery alliance has been organized to focus replantation services into a few expert centers. This model is slowly being adopted in other European centers. Resource factors include availability of a microsurgical team, microsurgical equipment, and high-quality nursing care that is essential to monitoring the viability of the replanted digit, which ultimately dictates success. The distance away from a microsurgical unit ultimately dictates the likelihood of the patient being offered replantation.
Ten-digit replantation
Replanting all 10 digits of both hands is challenging. In 1986, Ge and colleagues reported the survival of all 10 replanted digits of a 20-year-old woman after 31 hours of ischemia. Successful replantation of all amputated digits is a considerable technical challenge. The authors found in the Chinese literature 21 patients with successful replantation of all 10 digits in mainland China over the last 30 years.
Of these 21 patients, the youngest was 18 years old and the eldest was 45. The longest and shortest ischemia before re-establishing blood flow were 44 and 13.5 hours, respectively. The longest operative time was 34 hours (performed by 3 surgeons), and the shortest was 7 hours (by 4 teams of 8 surgeons).
The Teams
The experience in China indicates that for such severe traumatic cases as amputation of all 10 digits of both hands, at least 3 teams of surgeons are necessary, working on the proximal stumps in both hands and the amputated distal digits simultaneously, to avoid surgeon fatigue. If possible, 4 or more teams would be better. The dorsal veins, bilateral digital arteries, and bilateral nerves are marked with 9-0 nylon suture in the distal and proximal stumps of all 10 digits during debridement for ease of later repairs.
Two Methods: Structure-by-Structure and Digit-by-Digit
Brachial plexus anesthesia was used in most of these cases. To reduce operative time, digits were replanted using the structure-by-structure method , that is, performing bony fixation and tendon repairs in all digits first without using an operating microscope, followed by later vascular anastomosis under a microscope ( Fig. 1 ). The operative time with this method in the 3 cases reported by Xie and colleagues was relatively short: 9.5, 6.8, and 7.5 hours, respectively. The structure-by-structure method was used in 11 patients, for all of whom the entire operative time was less than 10 hours. One such case is illustrated in Figs. 2 and 3 .
Replantation of digits in 10 other patients was by the digit-by-digit method , that is, preserving amputated digits in a refrigerator at 4°C and taking them out one by one as replantation of each digit is completed (see Fig. 1 ). The average operative time of these 10 cases was 19.5 hours (range: 7.5–33.5 hours).
In most cases, phalanges were fixed by one longitudinal Kirschner wire (K-wire) or 2 crossed K-wires. All flexor digitorum profundus tendons, flexor pollicis longus tendons, and extensor tendons were repaired, with the modified Kessler method except in one case with a double right-angle suture repair and in another case with the Tsuge method. The bilateral proper digital nerves of each digit were repaired, except that in 5 cases, not all of the bilateral digital nerves were repaired in all digits. Liu and colleagues reported that no dorsal vein was available for anastomosis in an amputated thumb, but a volar vein in the pulp was found to be healthy enough. The thumb was treated by venous arterialization and nail extraction and was free of venous crisis. Wang and colleagues anastomosed all 20 proper digital arteries of the 10 digits and 40 veins for 10 digits with the goal of increasing replant survival.
Dealing with High Incidence of Vascular Crisis
Incidence of vascular crisis during or after surgery was high. Crisis occurred in 33% of cases and typically occurred between 1 hour to 4 days after surgery, and surgical exploration was performed immediately. In 3 patients, 3 or more attempts at surgical exploration and reanastomosis or vein grafting were necessary to deal with the vascular crisis. Depending on the findings during exploration after replantation, artery or vein reanastomosis or vein grafting were necessary.
Postoperatively, antibiotics, anticoagulants, and antivasospasm medications were administered intravenously for 5 to 7 days. Specific dosages were given in the reports of 2 cases. Ge and colleagues administered an intravenous infusion of penicillin for 5 days, low-molecular-weight dextran 500 mL twice a day for 6 days, and oral aspirin 500 mg 3 times daily for a week. Xie and colleagues used intravenous infusion of second-generation cephalosporins for a week, intramuscular injection of papaverine 30 mg 6 times daily for a week (then reduced to 30 mg 3 times a day for 4 days), intravenous infusion of low-molecular-weight dextran 500 mL twice daily for 9 days, and continuous intravenous infusion of saline 500 mL with heparin sodium 12,500 U 24 hours for 11 days.
Postoperative Rehabilitation
Passive and active motion of joints began 4 to 6 weeks after surgery in most cases, when K-wires were removed. However, reports do not offer detailed rehabilitation protocols. Cong and colleagues used an electronic heating apparatus to relieve swelling and alleviate pain in the first 2 weeks, and passive and active motion of joints began at 4 weeks. Constant force was applied to maintain passive flexion and extension of joints during a steam bath twice each day for an hour. Isometric and isotonic contraction of forearm and hand muscles was performed during active finger motion exercises.
Follow-up
Outcomes after follow-up more than 1 year were reported in 3 cases, despite that all authors reported that both hands of these patients have functionality in grasping and hold, or writing. Wang and colleagues reported that at 14 months, active motion was 70° and 40° at the metacarpophalangeal (MP) and the interphalangeal (IP) joints of the left thumb, respectively, and 70° and 35° at the MP and IP joints of the right thumb, respectively. The index, middle, ring, and little fingers could move for 220°, 210°, 205°, and 200°, respectively, in the left hand, and 200°, 210°, 205°, and 200°, respectively, in the right hand. Cong and colleagues reported that at 1 year after surgery active motion of the left thumb was 130° and right thumb was 140°, and finger motion ranged from 200° to 240°. Ou and colleagues reported that active motion of the left thumb was 65° and right thumb was 80°. The finger motion ranged from 115° to 260° at 7-year follow-up. Two reports described tenolysis in 10 digits at 4 to 6 months after replantation.
Digital replantation with local tissue defects
Local segmental crush injuries to the digits are common in digital amputation. In most cases, bony shortening and debridement of the crushed tissues ensure good quality of the vessels for anastomosis. However, if avulsion involves a large area of soft tissue or soft tissue or bone is missing, it is necessary to graft tissues to repair the defects. If segmental vascular defects are also present, a flow-through flap or a composite tissue transfer serving as flow-through tissue is a common way to solve this problem.
A few methods used for such conditions are given ( Fig. 4 ): (1) a venous flap as a flow-through flap to repair the soft tissue defect and to reconstruct the vessels; (2) a free flap from the arm or lower extremity to cover the soft tissue defect; (3) a pedicled flap from the adjacent digit, such as a pedicled digital artery flap, to restore arterial blood flow to the amputated digit; (4) an iliac bone graft to fill a defect in the phalanx; and (5) a toe joint transfer with a plantar or dorsal skin flap to reconstruct a missing joint and soft tissues in the hand. The authors provide illustrations of the “flow-through” flap procedures in Figs. 5–7 .
