Recognition of a possible vascular injury is a critical skill for any orthopaedic surgeon. This is true whether the surgeon’s primary area of practice is the emergency or urgent procedures associated with orthopaedic trauma or elective reconstruction. When injured patients have fractures of long bones, the pelvis, or spine; dislocations adjacent to major vessels; or severely contused or crushed extremities, loss of limb or life can occur if recognition of the associated vascular trauma is delayed. In an elective practice, many orthopaedic operative procedures occur in proximity to major vessels, where an iatrogenic injury may result in loss of limb or life.
Major changes in diagnosis and management of vascular injuries over the past 5 years have been in imaging, increased use of temporary intraluminal vascular shunts, endovascular therapies, and lessons learned during Operation Iraqi Freedom and Operation Enduring Freedom (Afghanistan).
History
Although vascular repairs in the extremities were first performed nearly 250 years ago, progress in this area was limited until the early part of the 20th century. From 1904 to 1906, Alexis Carrel (1873–1944) and Charles C. Guthrie (1880–1963) at the University of Chicago and others developed standard vascular operative techniques, including repair of the lateral arterial wall, end-to-end anastomosis, and insertion of venous interposition grafts. Early attempts at operative repair included those by V. Soubbotitch in the Balkan Wars from 1911 to 1913, by the British surgeon George H. Makins and German surgeons in World War I, and by R. Weglowski during the Polish-Russian War of 1920. Despite the availability of these techniques, it was not until the latter part of World War II that renewed attempts were made to perform peripheral arterial repair rather than ligation. Before that time, delays in medical care for casualties, lack of antibiotics, and a significant incidence of late infection in injured soft tissues of the extremities contributed to an operative approach dominated by ligation.
With the more rapid transfer of casualties to field hospitals, the availability of type-specific blood transfusion, the introduction of antibiotics, and the increased use of the autogenous saphenous vein as a vascular conduit, vascular repairs were performed frequently in the later stages of the Korean War and routinely throughout the Vietnam War. More recently, civilian trauma surgeons have treated large numbers of patients with peripheral vascular injuries, many associated with orthopaedic trauma, and they have been able to build on the techniques for repair of traumatic vascular injuries described originally by military surgeons. During Operation Iraqi Freedom and Operation Enduring Freedom, multiple contributions to the field have come from military vascular surgeons (to be discussed).
Etiology
In urban trauma centers, peripheral vascular injuries are most commonly caused by low-velocity missile wounds from handguns. For example, gunshot wounds cause 55% to 75% of all vascular injuries in the lower extremities in such centers. In contrast, stab wounds account for most of the civilian peripheral vascular injuries in countries where firearms are more difficult to obtain.
Vascular injuries from blunt orthopaedic trauma, such as fractures, dislocations, contusions, crush injuries, and traction ( Fig. 15-1 ), account for only 5% to 30% of injuries being treated ( Table 15-1 ). In particular, vascular injuries associated with long bone fractures in otherwise healthy young trauma patients are rare. The reported incidence of injuries to the superficial femoral artery in association with a fracture of the femur has been less than 1% to 2% in large series. Injuries to the popliteal artery, tibioperoneal trunk, or trifurcation vessels occur in only 1.5% to 2.8% of all tibial fractures. When open fractures of the tibia are reviewed separately, the incidence of arterial injuries is approximately 10%. With dislocations of the knee joint, the incidence of injuries to the popliteal artery requiring surgical repair was less than 16% in one large series. These figures are significantly lower than those reported in the past for posterior dislocations of the knee and presumably reflect, in part, the current nonoperative approach to nonocclusive lesions (i.e., intimal defect, narrowing) of the popliteal artery.
| Fracture or Dislocation | Artery Injured |
|---|---|
| Upper Extremity | |
| Fracture of clavicle or first rib | Subclavian artery |
| Anterior dislocation of shoulder | Axillary artery |
| Fracture of neck of humerus | Axillary artery |
| Fracture of shaft or supracondylar area of humerus | Brachial artery |
| Dislocation of elbow | Brachial artery |
| Lower Extremity | |
| Fracture of shaft of femur | Superficial femoral artery |
| Fracture of supracondylar area of femur | Popliteal artery |
| Dislocation of the knee | Popliteal artery |
| Fracture of proximal tibia or fibula | Popliteal artery, tibioperoneal trunk, tibial artery, or peroneal artery |
| Fracture of distal tibia or fibula | Tibial or peroneal artery |
| Skull, Face, or Cervical Spine | |
| Basilar skull fracture involving sphenoid or petrous bone | Internal carotid artery |
| Le Fort II or III fracture | Internal carotid artery |
| Cervical spine, especially foramen transversarium | Vertebral artery |
| Thoracic Spine | Descending thoracic aorta |
| Lumbar Spine | Abdominal aorta |
| Pelvis | |
| Anterior-posterior compression | Thoracic aorta |
| Subtypes of pelvic fractures | Internal iliac, superior gluteal, or inferior gluteal artery |
| Acetabular fracture | External iliac, superior gluteal, or femoral artery |
As previously noted, there are also well-documented associations between certain elective and emergency orthopaedic operative procedures and arterial injuries ( Table 15-2 and Fig. 15-2 ).
| Orthopaedic Procedure | Artery Injured |
|---|---|
| Upper Extremity | |
| Clavicular compression plate or screw | Subclavian artery |
| Anterior approach to shoulder | Axillary artery |
| Closed reduction of humeral fracture | Brachial artery |
| Lower Extremity | |
| Total hip arthroplasty | Common or external iliac artery |
| Nail or nail-plate fixation of intertrochanteric or subtrochanteric hip fracture | Profunda femoris artery |
| Subtrochanteric osteotomy | Profunda femoris artery |
| Total knee arthroplasty | Popliteal artery |
| Anterior or posterior cruciate ligament reconstruction | Popliteal artery |
| External fixator pin | Superficial femoral, profunda femoris, popliteal, or tibial arteries |
| Spine | |
| Anterior spinal fusion | Abdominal aorta |
| Lumbar spine fixation device | Abdominal aorta |
| Resection of nucleus pulposus | Right common iliac artery and vein, inferior vena cava |
| Pelvis | |
| Posterior internal fixation of pelvic fracture | Superior gluteal artery |
| Excision of posterior iliac crest for bone graft | Superior gluteal artery |
Some of these may be noted during surgery or in the early postoperative period (e.g., occlusion of the iliac artery during total hip arthroplasty), but others may appear weeks or months later (e.g., ruptured pseudoaneurysm of a tibial artery).
Locations and Types of Vascular Injuries
The brachial artery and vein in the upper extremity and the superficial femoral artery and vein in the lower extremity are the most commonly injured vessels in both civilian and military reports in which penetrating wounds predominate. This can be explained by the length of these vessels in the extremities and by the fact that direct compression controls hemorrhage, so that few patients exsanguinate before arrival at the emergency center. Because of the low incidence of injuries to these vessels from blunt trauma, orthopaedic services most commonly encounter occlusions and occasional lacerations of the popliteal, tibioperoneal, tibial, or peroneal arteries from dislocations of the knee or severe fractures of the femur or tibia.
Intimal injuries (flaps, disruptions, or subintimal hematomas), spasm, complete wall defects with pseudoaneurysms or hemorrhage, complete transections, and arteriovenous fistulas are the five recognized types of vascular injuries. Whereas intimal defects and subintimal hematomas with possible secondary occlusion continue to be most commonly associated with blunt trauma, wall defects, complete transections, and arteriovenous fistulas are usually seen after penetrating wounds. Spasm can occur after either blunt or penetrating trauma to an extremity.
Diagnosis
History and Physical Examination
Patients sustaining peripheral arterial injuries usually have hard or soft signs of injury. Examples of hard signs of arterial injury are any of the classic signs of arterial occlusion (pulselessness, pallor, paresthesias, pain, paralysis, poikilothermy), massive bleeding, a rapidly expanding hematoma, and a palpable thrill or audible bruit over a hematoma. In patients with impending limb loss from arterial occlusion, a rapidly expanding hematoma or significant external bleeding from an extremity, immediate surgery without preliminary arteriography of the injured extremity is justified. If a hard sign is present, other than an expanding hematoma or external bleeding but localization of the defect is necessary before the incision is performed as in a patient with fractures at several levels, a rapid duplex ultrasound study or surgeon-performed arteriogram in the emergency center or operating room (OR) should be obtained.
Soft signs of arterial injury include a history of arterial bleeding at the scene or in transit; proximity of a penetrating wound or blunt injury to an artery in the extremity; a small, nonpulsatile hematoma over an artery in an extremity; and a neurologic deficit originating in a nerve adjacent to a named artery. These patients still have an arterial pulse at the wrist or foot on physical examination or with use of the Doppler device. The incidence of arterial injuries in such patients ranges from 3% to 25%, depending on which soft sign or combination of soft signs is present. Most, but not all, of these arterial injuries can be managed without surgery because they are small and, by definition, allow for continuing distal perfusion. In some centers, serial physical examinations alone are used to monitor distal pulses, and no arteriogram is performed to document the magnitude of a possible arterial injury. This approach has been safe and accurate in asymptomatic patients with penetrating wounds to an extremity in proximity to a major artery. Its accuracy with the higher kinetic energy injuries associated with blunt fractures or dislocations, particularly dislocations of the knee, is similar. Observation is appropriate only with complete and continuing out-of-hospital follow-up. When there is concern about a distal pulse deficit, inability to properly examine for distal arterial pulses, or a combination of soft signs of an arterial injury in an extremity, either duplex ultrasonography or some type of arteriography is indicated.
Beyond the obvious hard or soft signs of vascular injury, physical examination of the injured extremity includes observation of the position in which the extremity is held, the presence of any obvious deformity of a long bone or joint, the presence or absence of an open wound or bony crepitus, the skin color of the distal extremity compared with that of the opposite side (in light-skinned persons), the time required for skin capillary refill in the distal digits, and a complete motor and sensory examination. In the lower extremity, the mobility of the knee joint should be carefully assessed as well. Increased laxity of the supporting ligaments suggests that a dislocation of the knee joint from the original trauma has spontaneously reduced ( Fig. 15-3 ). Because of the previously noted association between posterior and other dislocations of the knee and injury to the popliteal artery, an imaging study is indicated if pedal pulses are diminished or absent after reduction. Several studies suggest that routine arteriography is not indicated if normal pulses are present after spontaneous or orthopaedic reduction of a knee dislocation, although not all agree with this approach. If the exact vascular status of the distal extremity is unclear after restoration of reasonable alignment or reduction of a dislocation, a Doppler flow detector should be applied to the area of absent pulses in the distal extremity for audible assessment of blood flow. The Doppler flow detector also can be used to compare systolic blood pressure measurements in an uninjured upper extremity with those in the injured upper or lower extremity. The arterial pressure index (API), defined as the Doppler systolic pressure in the injured extremity divided by that in the uninjured extremity, is then calculated. In a study by Lynch and Johansen in which clinical outcome was the standard, an API lower than 0.90 had a sensitivity of 95%, specificity of 97.5%, and accuracy of 97% in predicting an arterial injury. An alternative when both lower extremities are injured is to use the ankle-branchial index (ABI), which uses branchial artery pressure as the denominator. Because older patients have an increased incidence of preexisting atherosclerotic occlusive disease, the accuracy of the API or ABI is compromised.
Radiologic Studies
A noninvasive diagnosis can be made with use of duplex or color duplex ultrasonography in the emergency center, OR, or surgical intensive care unit (ICU) ( Table 15-3 ). Duplex ultrasonography is a combination of real-time B-mode ultrasound imaging and pulsed Doppler flow detection. Duplex or color duplex ultrasound imaging has been used to evaluate patients with possible or suspected arterial or venous injuries in the extremities for many years. Accuracy in detection of arterial injuries, using comparison arteriography as the gold standard, has ranged from 96% to 100% in several studies.
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Percutaneous arteriography performed in the emergency center or in the OR by the surgical team is infrequently used in most major trauma centers; several urban trauma centers, however, have extensive historical experience with the technique. A thin-walled, 18-gauge Cournand-style disposable needle is inserted either proximal to the area of suspected injury (e.g., in the common femoral artery for evaluation of the superficial femoral artery) or distal to it (e.g., in retrograde evaluation of the axillary or subclavian arteries above a blood pressure cuff inflated to 300 mm Hg). Rapid hand injection of 35 mL of 60% diatrizoate meglumine dye is performed, and an anteroposterior radiographic view is taken. The timing for exposure of the x-ray film of the patient’s extremity depends on which artery is to be evaluated. Proper evaluation of the tibial and peroneal arteries in the patient with a complex fracture of the tibia mandates that exposure not take place until 4 to 5 seconds after the injection of dye into the common femoral artery. The plane of the film is often changed before a second injection to examine the area in question more thoroughly. False-negative and false-positive results are rare when the technique is performed on a daily basis by experienced practitioners; however, this technique is rarely used in the modern era because of the availability of CT arteriography. If a patient has severe combined intracranial or truncal trauma and possible peripheral arterial lesions related to orthopaedic injuries, life-threatening injuries should be treated first, followed by percutaneous intraoperative arteriography of the involved extremity.
Percutaneous intraarterial digital subtraction arteriography performed in a radiology suite by the interventional radiologist was the most commonly used invasive diagnostic technique in patients with suspected vascular injuries prior to the availability of computed tomography arteriography (CTA). Multiple sequential views of areas of suspected arterial injury can be obtained at differing intervals after injection of limited amounts of dye. The accuracy of this multiple-view technique has been demonstrated in many studies, although false-negative results have occurred. The disadvantages of the technique are the delays in diagnosis when on-call technicians must return to the hospital, the cost of modern equipment, and the distortion of images when metallic fragments are present (e.g., shotgun wound).
Computed tomography arteriography is replacing intraarterial digital subtraction arteriography for evaluation of cervical, truncal, and peripheral arteries in many centers. Advantages include rapid evaluation of possible arterial injuries during CT evaluation of body parts, no need to wait for an out-of-hospital team from interventional radiology to return to the hospital, and the possibility of three-dimensional reconstructions of areas of arterial injury. One disadvantage is the presence of CT artifacts when missiles or metallic fragments are in the field of study, although one study has confirmed that this is not a significant problem.
Venography is rarely performed in major trauma centers because the sequelae of missed peripheral venous injuries such as venous thromboses or pseudoaneurysms are rare. In recent years, color duplex ultrasonography has been used to evaluate veins of the extremities after penetrating trauma. Some centers choose to explore large peripheral hematomas after penetrating wounds without preliminary venography, even if arteriography results are normal, and to observe small, nonexpanding hematomas.
Management of Vascular Injuries
The Emergency Center
The primary goal of the surgeon in the emergency center is to control hemorrhage in the patient with an extensive injury to the extremity. This has historically been accomplished by direct compression with a finger (remembering the aphorism that no vessel outside the human trunk is larger than the human thumb) or by application of a pressure dressing to the area of injury. If neither of these maneuvers controls hemorrhage, a blood pressure cuff is placed proximal to the area of injury and inflated to a pressure greater than the systolic blood pressure or a proximal tourniquet is applied as learned from the conflicts in Iraq and Afghanistan. When hemorrhage is under temporary control, the patient is transferred to the OR for definitive vascular repair or ligation.
In a patient with pulses that are questionably palpable or audible by Doppler flow detection distal to a long bone fracture or a dislocation in an extremity, immediate reduction and splinting or application of a traction device should be performed. This relieves compression or kinking, but not spasm, in the adjacent artery. If such a maneuver restores diminished distal pulses in comparison with the uninjured contralateral extremity, the API should be measured if the bony or ligamentous injury is in the proximal extremity. If the API cannot be obtained because of a distal injury, if the API is lower than 0.90, or if distal pulses are absent after reduction, immediate arteriography is mandatory. In children, because examination of the peripheral vascular system is difficult, arteriography should be used liberally whenever fractures are present and distal arterial pulses are questionably palpable.
In an injured patient with hypotension, resuscitation is by the administration of fresh whole blood (military) or packed red blood cells—fresh-frozen plasma—platelet packs in a 1 : 1 : 1 to 3 : 1 : 1 ratio rather than the 4 : 1 ratio taught previously. This “damage control resuscitation” approach was developed by U.S. military physicians in Iraq and has changed the way injured civilian patients are resuscitated.
Nonoperative Treatment of Arterial Injuries
If an arteriogram shows occlusion of only one major vessel below the elbow or knee when there is not a severely injured or mangled extremity, viability of the distal extremity is rarely compromised, and some centers choose to observe the patient in this situation. Because there can be retrograde flow into an area of arterial injury beyond the proximal occlusion, a repeat arteriogram should be performed within 3 to 7 days to rule out delayed formation of a traumatic false aneurysm.
As noted previously, several clinical studies have demonstrated that nonocclusive arterial injuries (e.g., spasm, intimal flap, subintimal or intramural hematoma) that often are detected in patients undergoing arteriography for soft signs of injury heal without operation in 87% to 95% of cases. Even small, traumatic false aneurysms have been noted to heal on follow-up arteriograms in some of these patients. Arteriographic follow-up is necessary in patients who develop new symptoms while being observed.
Therapeutic Embolization
Isolated traumatic aneurysms of branches of the axillary, brachial, superficial femoral, or popliteal arteries; of the profunda femoris artery; or of one of the named arteries in the shank can be treated by therapeutic embolization instead of operation. Although such an approach has been used primarily in patients with penetrating wounds to the extremities, it is appropriate in selected patients with blunt vascular injuries as well. Patients with injuries to the arteries listed who will especially benefit from therapeutic embolization include those with multisystem injuries, closed fractures, or late diagnosis of a traumatic aneurysm after orthopaedic reconstruction. Contained aneurysms or active hemorrhage from muscular branches is treated with embolization using an absorbable gelatin sponge. When there is a need to occlude a tibial or peroneal artery proximal to a traumatic aneurysm, embolization coils are used.
Endovascular Stents and Stent Grafts
Balloon-expandable intraluminal arterial stents and stent grafts are now used routinely in patients with atherosclerotic occlusive disease. Extensive experience has been reported in patients with traumatic arterial injuries over the past 20 years as well. For treatment of an intimal dissection or flap, an angiographic catheter is placed percutaneously across the area of injury via a transarterial sheath. This catheter is then exchanged for a separate catheter-mounted balloon inflatable endovascular stent, and the collapsed stent is expanded in place. If a traumatic aneurysm is present, an endovascular stent graft is used to occlude the orifice or trans-stent injections of microcoils are used to induce thrombosis of the aneurysmal sac.
The Operating Room
Arterial Repair
If the history, physical examination, duplex ultrasound, or arteriogram strongly suggests or documents the presence of an arterial injury that requires operative repair, the patient is given intravenous antibiotics before being moved to the OR. During the move, all open wounds are covered with sterile gauze soaked in saline or saline–antibiotic solution. In addition, all fractured or dislocated extremities are maintained in a neutral position by splinting or traction.
Skin Preparation and Draping
In the OR, an operative tourniquet can be applied in place of the blood pressure cuff for control of hemorrhage from injuries in the distal extremity. If the injuries are in the proximal extremity and exsanguinating hemorrhage resumes after removal of finger compression, a compression dressing, or a proximal blood cuff, a member of the surgical team should put on sterile operative gloves immediately. This individual then applies direct compression to a large wound with the hands or inserts fingers into an open fracture site or the entrance and exit sites of a penetrating wound to control hemorrhage as preparation of the skin and draping are performed.
Because of the possibility of an associated vascular lesion in all patients with orthopaedic injuries in an extremity, preparation of the skin and draping should encompass all potential areas of proximal and distal vascular control. Also, one or both lower extremities should be prepared and draped to allow for possible retrieval of the greater saphenous vein in case an interposition graft is required for the vascular repair. It is often helpful to have one entire uninjured lower extremity prepared and draped to the toenails, so that the greater saphenous vein may be retrieved from either the groin or the ankle. It is also helpful to drape the hand or foot of the affected extremity in a sterile plastic bag, so that color changes can be noted in light-skinned patients and distal pulses can be palpated under sterile conditions after arterial repair has been completed. The remainder of the extremity, including the area of the incision, is then covered with an orthopaedic-type stockinette.
Incisions
In patients with peripheral vascular injuries, the skin incision should be generous enough to allow for comfortable proximal and distal vascular control. To this end, it is often best for an inexperienced trauma surgeon to use the most extensive incisions.
There are a number of classic incisions for the management of peripheral vascular injuries. Those used in the upper extremity include (1) supraclavicular incision, with or without division of or resection of the clavicle, for injuries in the second or third portion of the subclavian artery; (2) infraclavicular incision for the first or second portion of the axillary artery; (3) infraclavicular incision curving onto the medial aspect of the upper arm for the third portion of the axillary artery or proximal brachial artery; (4) medial upper arm incision between the biceps and the triceps muscles for the main portion of the brachial artery; and (5) S-shaped incision from medial to lateral across the antecubital crease for the brachial artery proximal to its bifurcation. An injury to the radial or ulnar artery is usually approached by a longitudinal incision directly over the site.
In the lower extremity, the preferred incisions for arterial repair are (1) longitudinal groin incision for injury to the common femoral artery, proximal superficial femoral artery, or profunda femoris artery; (2) anteromedial thigh incision for exposure of the superficial femoral artery throughout the thigh; and (3) medial popliteal incision for exposure of the proximal, middle, or distal portions of the popliteal artery. Whereas injuries to the anterior tibial artery are approached directly over the site of injury in the anterior compartment, the posterior tibial artery is approached through a medial incision in the leg that often requires transection of the fibers of the soleus muscle. Finally, the peroneal artery is approached through a similar medial incision in the leg or through a lateral incision that requires excision of a portion of the fibula for proper exposure.
Standard Techniques of Arterial Repair
After the skin incision is made proximally and distally to the bleeding site or area of hematoma, dry skin towels are placed to cover all remaining skin edges if a plastic adherent drape has not been applied. If hemorrhage can be controlled by finger or laparotomy pad compression applied by an assistant, proximal and distal vascular control is usually obtained before the area of injury is entered. Not dissecting far enough proximally and distally from an area of injury is a common error. It is frequently necessary for an inexperienced vascular trauma surgeon to move proximal and distal vascular occlusion clamps or loops repeatedly as débridement of the injured artery is extended back to noninjured arterial intima.
In patients with an extensive hematoma overlying the arterial injury, it can be difficult to obtain proximal and distal vascular control close enough to the injury to prevent backbleeding from collateral vessels. In addition, there are patients in whom external hemorrhage cannot readily be controlled during meticulous dissection. Therefore, if dissection is proceeding extremely slowly through a very large hematoma or the assistant can no longer maintain control of exsanguinating hemorrhage by direct compression, the hematoma or site of hemorrhage should be entered directly. The site of arterial bleeding is visualized and compressed with a finger or vascular forceps, and a proximal vascular clamp or vessel loop is applied. The dissection is then completed starting from the center rather than waiting for proximal and distal control to be obtained at a distance from the hematoma or bleeding site.
After vascular control is obtained in either classic or rapid fashion, vascular occlusion can be maintained by application of small, angled vascular clamps (such as those found in an angioaccess tray), bulldog vascular clamps, Silastic vessel loops, or umbilical tapes. Occasionally, with complex arterial injuries at bifurcations, vascular control of major branches can be obtained by passage of an intraluminal Fogarty balloon catheter or a calibrated Garrett dilator.
In general, lateral arteriorrhaphy (or venorrhaphy) with 5-0 or 6-0 polypropylene sutures placed transversely is used for small lacerations or for small puncture, pellet, or missile wounds, especially in the smaller vessels of the extremities. If a transverse repair results in significant narrowing of the injured vessel, patch angioplasty is a useful alternative that is rarely used because of concerns about sizing. Any segment of injured vein that has been resected or of autogenous saphenous vein from the ankle or groin of an uninjured lower extremity can be used to create an oval patch to increase the size of the lumen of an injured vessel. The patch is usually sewn in place with 6-0 polypropylene suture.
Resection of injured peripheral vessels is often required in patients with blunt orthopaedic trauma because of the magnitude of the forces applied to cause both bony and vascular injuries. An increasing number of vascular injuries from penetrating wounds also require resection of the injured segment because of the greater wounding power of firearms now used in the United States. Resection with an end-to-end anastomosis is performed whenever a segment of a vessel has extensive destruction of the wall or a long area of disrupted intima (e.g., from blunt traction injury or through-and-through injury from a penetrating wound). Despite the elasticity of peripheral vessels in the typical young trauma patient, many collateral vessels must be ligated for an end-to-end anastomosis to be performed if more than 2 to 3 cm of the vessel is resected. An end-to-end anastomosis sewn under tension results in an hourglass appearance at the suture line and often leads to thrombosis of the repair in the postoperative period. Although an interrupted suture technique for end-to-end anastomosis is routinely used in growing children, continuous suture techniques with two-point fixation 180 degrees apart are used by experienced trauma surgeons for small vessels of the extremities (4–5 mm diameter) in adults.
If exposure is difficult, as in the axillary artery near the clavicle or the popliteal artery behind the knee joint, it is often helpful to perform the first third of the posterior anastomosis with an open technique (i.e., one in which no knot is tied). This allows for precise suture bites of the posterior walls, and it prevents leaks after arterial inflow is restored. On completion of the posterior third of the anastomosis, the two ends of the suture are pulled tight, drawing the two ends of the artery together.
Both ends of the artery are then stabilized, and Fogarty embolectomy catheters are passed proximally and distally to remove any thrombotic or embolic material from the arterial tree. The amount of debris distal to an arterial injury can be extensive, especially after a prolonged period of preoperative occlusion. After both ends of the vessel have been cleared, 15 to 20 mL of regional heparin (50 units/mL) is injected into each end, and the vascular clamps are reapplied. Injection of a total of 30 to 40 mL of this solution (1500–2000 units or 15–20 mg heparin) provides significantly less anticoagulation than the 1 to 2 mg/kg of heparin used in many elective vascular procedures. More aggressive systemic heparinization is avoided in selected trauma patients because of the risk of hemorrhage from other injuries.
The end-to-end anastomosis is completed by running the two ends of the suture along the two sides of the approximated artery, leaving the last few loops of suture loose to allow for flushing before final tying. The proximal vascular occlusion clamp is first removed and reapplied after completion of flushing. The distal vascular clamp is then removed to allow for flushing from the distal end of the vessel and to clear any residual air underneath the suture line. As blood from the distal arterial tree fills the area that was between the two clamps or loops, the two suture ends are pulled up tightly and tied. The proximal arterial clamp is not released until the first knot is in place. If small suture hole leaks are present at that time, topical hemostatic agents can be applied temporarily.
If an end-to-end anastomosis cannot be performed with minimal tension, a substitute vascular conduit should be inserted into the defect between the two débrided ends of the injured vessel. An autogenous reversed saphenous vein graft from an uninjured lower extremity remains the conduit of choice for most peripheral vascular injuries ( Fig. 15-4 ). If the vessel to be replaced has a small lumen (4–5 mm), the greater saphenous vein at the medial malleolus is a good choice. If the artery or vein to be replaced has a much larger lumen, the greater saphenous vein in the proximal thigh is a better choice. Major advantages of the autogenous saphenous vein include its ready availability, the superiority of natural tissue in maintaining patency, and a long record of success in vascular and cardiac surgery. The patency of the saphenous vein graft can be improved by using gentle dissection, by avoiding overdistention during flushing, and by using only heparinized autologous blood containing papaverine for flushing before insertion.
