Douglas P Hanel MD Simon H Chin MD

Section of Hand and Microvascular Surgery, Department of Orthopaedics and Sports Medicine, Harborview Medical Center, 325 Ninth Avenue, Seattle, WA 98104-6499, USA

Since Malt and McKhann's first successful arm replantation in 1962, upper extremity replantation surgery techniques have been refined and spread worldwide [1-3]. Nevertheless, replantation at or proximal to the wrist, referred to from here on as wrist-proximal replants, remains a daunting challenge that presents the hand surgeon with an array of difficulties distinct from digital replantation.

The significance of undertaking a wrist-proximal replantation must be adequately assessed by both the surgeon and cogently presented to the patient. The graphic nature of a wrist-proximal amputation often dominates the concern of both the patient and hospital personnel, but initial priority must be given to the identification of any other life-threatening associated injuries. The latter must be appropriately addressed initially and, indeed, may preclude the possibility of limb replantation.

Godina and colleagues [4] advocated temporary ectopic replantation using the thoracodorsal vessels in upper extremity amputees who could not tolerate a long replantation procedure because of other life-threatening injuries. Wang and colleagues [5] have extended this concept and reported a proximal wrist replant that took place 319 days after the initial injury by temporarily performing a quick ectopic implant of the severed hand and forearm into the groin. The authors caution that the results of secondary replantation are markedly inferior to primary replantation.

* Corresponding author. E-mail address: [email protected] (D.P. Hanel).

The practice of ectopic replantation is not widespread and will not be discussed further.

Initial emergent care

The amputated extremity should be viewed as a distraction to initial evaluation. The patient's vital signs, general health assessment, and general physical examination should be assessed and addressed first. Then the amputation stump is wrapped in a gauze dressing. Bleeding, when present, is addressed with compression. Tourniquets are not used! Since wrist-proximal amputations involve muscle, ischemic time is particularly important. Whereas digits may be routinely replanted with up to 24 hours of cold ischemia time and 12 hours of warm ischemia time, wrist-proximal amputations should be performed before 12 hours of cold ischemia time or 6 hours of warm ischemia time have elapsed [6]. Therefore, as part of the initial treatment, ambulance personnel and emergency physicians should be counseled to wrap the amputated part in gauze and cooled on ice (Fig. 1). Once this is done, decisions regarding the feasibility of revascularization or replantation are considered.

The description of the mechanism of the injury is critical. Those patients with broad crush or avulsion injuries are typically poor candidates for replantation (Fig. 2), whereas amputations resulting from sharp objects are the ideal candidates for replantation because the zone of injury is largely confined to the amputated site. Sufficient bone must be available for stable fixation, and the lacerated vessels, although frequently requiring interposition grafts, must have retained their distal capillary integrity. In the absence of these

0749-0712/07/$ - see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.hcl.2007.01.001

Fig. 1. The amputated part is kept on ice until revascularization. While the patient is being prepped for surgery, the amputated part is prepared for replantation. Core sutures are placed in the tendons and the nerves and arteries are tagged.

conditions, successful replantation is impossible and the patient should be informed of this reasoning. In addition, the referring hospital and the patient should be informed that those patients with incomplete amputations fare better than complete amputations; Blomgren and colleagues [7] identified decreased operative time, reduced postoperative morbidity, and a 92% successful reconstruction in the former versus prolonged

Fig. 2. Sharp amputations, as seen in Fig. 1, that result from knife lacerations or saws with a narrow kerf, are ideal candidates for replantation. In contradistinction, broad crush or avulsion injuries are not.

operative time, increased morbidity, and a 71% success rate in the latter.

A pertinent medical history must be obtained during this process. Cardiac, pulmonary, and neurologic status must be weighed against the stress of transport and subsequent surgery. For example, a recent myocardial infarction or dementia would serve as absolute contraindications for replantation surgery. Strict guidelines for other conditions such as diabetes, renal failure, or a prolonged history of nicotine consumption do not exist. The patient needs to be informed that the complication rate is higher and the success rate lower with these conditions and a lengthy operation and hospitalization may end in failure.

Social history is also relevant to the decision. The patient's age, occupation, and social situation influence the aggregate candidacy of the patient for replantation. A return to gainful employment is usually greater than 24 months in manual laborers, a period of time that may be unacceptable to a self-employed tool user such as a carpenter, farmer, or rancher.

Given no contraindications, expeditious transport must then be arranged; air transport is the standard method for long-distance referrals and ground transport for more local referrals.

In those patients where the transport time is prolonged, a temporary vascular shunt may be helpful. Shunts are particularly useful for patients with incomplete amputations [6,8]. An intact skin bridge or a single intact vein is ideal, while arterial flow is reconstituted with a carotid shunt or a large intravascular catheter (Fig. 3). This procedure should be performed in the controlled setting of an operating room and once placed the shunts should be secured with silk sutures or ''vessel helpers'' [8]. In cases of complete amputations a venous and arterial shunt are essential or the patient may exsanguinate during the transportation. The risk of exsanguination even with arterial and venous shunts is high enough that we advise using this technique with caution. Patients with shunt procedures will require blood transfusion and should be transported with 4 units of typed and cross-matched packed red blood cells (PRBCs). Most importantly, the efforts described above need to be weighed against the overlying theme that no single extremity is worth a patient's life and these shunting efforts as well as replantation may prove impractical. In addition, the time delay for the shunt procedure may override the benefits of revascularization. As a general guideline, the

Fig. 3. (A) Using an arterial shunt, the forearm of this Montana farmer was kept vascularized during an 8hour transport to Seattle. His major nerves, the bra-chioradialis, and the index and middle finger profundus tendons were in continuity. A 3-cm skin bridge was intact dorsally. (B) His radiographs reveal a fracture dislocation of the elbow and a fracture of the radius and ulna diaphysis. (C) The placement of the shunt allowed us to perform meticulous debridement, stabilize the skeleton, (D), revascularize the limb, and perform immediate soft tissue reconstruction with free tissue coverage.

Fig. 3. (A) Using an arterial shunt, the forearm of this Montana farmer was kept vascularized during an 8hour transport to Seattle. His major nerves, the bra-chioradialis, and the index and middle finger profundus tendons were in continuity. A 3-cm skin bridge was intact dorsally. (B) His radiographs reveal a fracture dislocation of the elbow and a fracture of the radius and ulna diaphysis. (C) The placement of the shunt allowed us to perform meticulous debridement, stabilize the skeleton, (D), revascularize the limb, and perform immediate soft tissue reconstruction with free tissue coverage.

authors consider emergent shunt procedures in patients with transportation times greater than 6 hours.

Upon arrival to the replantation center, the patient is again evaluated for unrecognized injuries to the head, chest, and abdomen. A concise but thorough history of the incident is obtained. Radiographs of both the amputated and the remaining upper extremity are performed. Initial laboratory values include hemoglobin, hemato-crit, serum electrolytes, blood urea nitrogen, creatinine, basic liver function, and a type and cross match for 4 units of PRBCs. For the next 5 days 4 units of PRBCs are always available.

Finally, the expectations and risks associated with the reconstructive effort must be thoroughly explained to the patient. The immediate expectation for patients with incomplete amputations is better than complete amputations; Blomgren and colleagues [7] identified decreased operative time, reduced postoperative morbidity, and a 92% successful reconstruction in the former versus prolonged operative time, increased morbidity, and a 71% success rate in the latter. The risk includes loss of limb, infection, multiple secondary procedures, and rarely loss of life. The shifts in fluid status pre- and intraoperatively and the toxicity of ischemia-reperfusion of muscle tissue are well documented. Acidosis, hyperkalemia, production of free radicals, and liberation of the inflammation cascade follow. ICU monitoring is required with administration of frequent blood products [9]. Informed consent is critical both to the patient and the surgeon in this undertaking.

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