Popliteal artery injuries: Civilian experience with sixty-three patients during a twenty-four year period (1960 through 1984)

Transcription

1 Popliteal artery injuries: Civilian experience with sixty-three patients during a twenty-four year period (1960 through 1984) Allan R. Downs, M.D., F.R.C.S.C., and Peter MacDonald, M.D., Winnipeg, Manitoba, Canada Our experience with 63 patients who had popliteal artery injuries sustained in civilian accidents is reported. Blunt injuries occurred in 53 patients and 49 had associated skeletal injuries. Eighteen patients suffered knee dislocation; six of these patients had associated fractures. Fractures of the upper third of the tibia occurred in 21 patients. Five patients had irreversible ischemia and required primary amputation. Thirteen amputations were required in 58 patients in whom arterial repair was performed, for an amputation rate of 22%. There were no amputations in 19 patients treated less than 6 hours after injury was sustained. Four deaths occurred. Fasciotomy was performed in 20 patients. Skeletal injuries were usually treated with external fixation. (J VASC SURG 1986; 4:55-62.) Although the treatment of vascular injuries has become standardized in the past three decades and many surgeons are now familiar with the techniques of arterial repair, the successful repair of the injured popliteal artery remains a challenge. In a review of 150 popliteal injuries from Vietnam by Rich, Baugh, and Hughes ~ the amputation rate was 32%. This figure does not differ from the Korean experience cited by Hughes, 2 who reported an amputation rate of 32.4% for popliteal injuries. Drapanas et al? in a civilian experience have reported a 42.8% failure rate in the repair of 14 popliteal artery injuries. More recent experiences reported by Snyder, 4 Lim et al., 5 and Holleman and Killebrew 6 have shown a significant reduction in amputation rate; however, most of their patients suffered penetrating injuries caused by low-velocity gunshot wounds. The poor prognosis for limb survival, which results when the popliteal artery is injured in association with a fracture or dislocation at the knee, has been noted by several authors. 7-m This report emphasizes the difficulties in diagnosis and management of popliteal artery injuries in blunt trauma. PATIENTS Sixty-three patients with injuries of the popliteal artery were admitted to the Health Sciences Centre (formerly Winnipeg General Hospital) during the From the Department of Surgeu, University of Manitoba and Health Sciences Centre. Reprint requests: A. R. Downs, M.D., F.R.C.S.C., Department of Surgery, Universiw of Manitoba and Health Sciences Centre, 700 William Ave., Winnipeg, Manitoba, Canada R3E 0Z3. past 24 years. The study comprised 53 male and 10 female patients, ranging in age from 10 to 73 years with 82% between 10 and 40 years of age. Fiftythree patients sustained blunt injuries and 10 patients suffered penetrating injuries (Table I). This high proportion of blunt injuries is in marked contrast to the experience reported by others. 1'~-~ Motor vehicle accidents caused 35 of the injuries. A variety of industrial, farm, household, and sporting accidents accounted for the injury in 21 patients and only seven of the injuries were due to gunshot wounds (Table II). INJURIES Associated skeletal injury. Skeletal trauma accompanied the arterial injury in 49 of the 63 patients (Table III). Eighteen patients had knee dislocations and six of these had associated fractures of the tibia and femur. Most of the dislocations had undergone spontaneous reduction or had been reduced before patients were admitted to this hospital. The diagnosis of dislocation was established by an assessment of the degree of mobility of the knee joint with the patient under anesthesia (Fig. 1) and the finding at surgical exploration of a disrupted joint. The importance of recognizing a knee dislocation with a femoral shaft fracture was emphasized in one patient whose femoral artery, was examined at the fracture site only to find that the artery was intact (Fig. 2). There was a popliteal occlusion at the level of the knee joint with a complete disruption of the cruciate ligaments and posterior capsule of the joint. Twent T- six patients had fractures of the upper third of the 55

2 56 Downs and MacDonald Journal of VASCULAR SURGERY Table I. Mechanism of arterial injury No. % Blunt with skeletal lesion Blunt without skeletal lesion 9 14 Penetrating Total Table II. Type of accident No. Motor vehicle 35 Crush 9 Fall 4 Grain auger 1 Power takeoff 1 Football 1 Skiing 2 Gunshot wound 7 Penetrating object 2 Conveyor belt 1 Total 63 Fig. 1. Examination of compound anterior dislocation of knee with patient under general anesthesia. tibia and fibula. Two patients had a fracture of the femoral shaft, together with a fracture of the upper third of the tibia. There were seven supracondylar fractures of the femur with a popliteal artery injury. The two patients with midshaft tibial fracture probably also had a hyperextension injury at the level of the knee joint to produce transection of the popliteal artery. Kennedy n has demonstrated that a hyperextension injury at the knee joint may cause either anterior dislocation or fracture of the upper third of the tibia. Either injury may be associated with a traction injury of the popliteal artery. Associated soft tissue injury. Popliteal vein trauma occurred in 17 patients. All 10 patients with penetrating injuries had vein involvement, whereas only seven patients with blunt trauma had disruption of the vein. Repair of the vein was accomplished by direct anastomosis in seven patients. The nature of the vascular injuries was not documented in three patients who required primary amputation. Thirtythree patients sustained trauma to the popliteal nerves but only three had disruption of nerves. One patient had a severed lateral popliteal nerve and one had disruption of both medial and lateral popliteal nerves. All three of these patients had amputation, although the arterial repair was patent. In the initial assessment, it is often difficult to distinguish between neuropraxia caused by direct contusion and that caused by ischemia, particularly if the sensory loss is of a stocking distribution. Nature of arterial injury. Six of seven patients with gunshot wounds had lacerations of the popliteal artery and one had complete disruption. Thirty patients had complete transection of the popliteal artery (Table IV). Most of these arteries exhibited attenuated ends, suggesting a traction type of injury. The arteries of 19 patients had intimal tears with thrombosis and five showed contusions with thrombosis. The intimal tear also appears to be a traction injury (Fig. 3). Two of the patients with contusion and thrombosis of the popliteal artery had suffered direct blunt trauma to the popliteal fossa. The arterial injuries of three patients who had primary amputations were not described. Of particular interest are two patients with double injuries to the popliteal artery. One patient with an anterior dislocation of the knee had a transection of the popliteal artery at the level of the knee joint and a further disruption of all layers except the adventitia at a more distal point. Another patient with fracture of the upper end of the tibia and fibula had intimal tears with thrombosis at two sites: one at the level of the joint and a second just proximal to the origin of the anterior tibial artery. In this type of traction injury, it is essential to examine the popliteal artery down to the origin of the anterior tibial artery to avoid missing this double

3 Volume 4 Number 1 July 1986 Popliteal artery injuries 57 Fig. 2. A, Femoral shaft fracture. B, Vein graft repair of popliteal occlusion at level of knee joint with associated disruption of knee. Table III. Associated skeletal injury and incidence of amputation No. Amputation % Knee dislocation Knee dislocation with femoral shaft fracture Knee dislocation with femoral and tibial shaft fractures Knee dislocation with tibial plateau and fibular fractures Knee dislocation with fracture fibula Upper tibia and fibula fractures Upper tibia and fibula with femoral shaft fractures Femoral supracondylar fractures Tibial midshaft fractures No skeletal injury Total lesion, which may jeopardize a good result. This can be accomplished either by direct exploration or distal intraoperative angiography. This type of traction injury may also produce spasm in the distal arterial branches and lead to difficulty in reestablishing distal flow. REPAIR AND RESULTS Four patients died, resulting in a mortality rate of 6.3% (Table V). All four patients had patent repairs with viable extremities. Three patients died of associated head injuries and a 73-year-old woman died of renal failure after successful revascularization of a severely ischemic limb 19 hours after injury. Eighteen of 63 patients required amputation, resulting in an amputation rate of 28%. Excluding the five patients in whom no repair was attempted because of irreversible ischemic changes, the amputation rate was 22.4%. Two of the 10 penetrating injuries resuited in amputation, whereas 11 of the 48 patients with blunt trauma who had arterial repair required amputation. None of the 19 patients who had direct anastomosis of the popliteal artery had failure of the repair or amputation. This repair is less susceptible

4 58 Downs and MacDonald Journal of VASCULAR SURGERY Fig. 3. A, Excised intact popliteal artery with occlusion. B, Opened artery with intimal fracture and thrombosis. Table IV. Type of arterial injury No. % Transection Laceration 6 10 Intimal tear and thrombosis Contusion and thrombosis 5 8 Unknown 3 5 Total to infection and it is generally easier to obtain soft tissue cover over the anastomosis; however, one should not hesitate to use a vein graft to avoid tension at the anastomosis. Thirty-five patients had vein grafts performed with five occlusions and 11 amputations. A cephalic vein was used in one patient and the ipsilateral popliteal vein was used in another patient. The ipsilateral saphenous vein was used in 28 of the remaining 33 patients. One failed vein graft repair was successfully revised to an end-to-end anastomosis by mobilization of the popliteal artery. One graft occlusion was a result of infection complicating internal fixation and fasciotomy, and this patient eventually needed amputation after several months. Four vein graft occlusions were considered to be technical failures. Three prosthetic grafts were used early in the experience with one occlusion. One patient had an amputation because of a severed sciatic nerve although the arterial repair was patent. Fortyone patients were discharged with a patent repair and functioning limb. Management of the skeletal injury. External fixation with a plastic cylinder for 6 to 8 weeks has been the treatment of choice for knee dislocation. One patient had a formal repair of the cruciate ligaments and the posterior capsule of the joint. Internal fixation was used for four femoral shaft fractures and seven tibial fractures. Internal fixation is usually not necessary to provide sufficient stability for arterial repair because of the muscle bulk in the lower extremity. Skeletal traction has been used for femoral and tibial shaft fractures without adverse results. One patient with fractures of the femur and tibia had intramedullary fixation of both fractures before arterial repair with a good result. In such instances, with a flail limb, fixation of one or both fractures may be necessary before arterial repair. The minimum amount of operative intervention required to accomplish stability is advisable. The duration of ischemia

5 Volume 4 Number 1 July 1986 Popliteal artery injuries 59 Fig. 4. A, Fractured upper third of tibia with popliteal artery occlusion. B, Internal fixation with circumferential wire. C, Intact arterial repair with bone loss caused by infection ending in amputation 5 months after repair. should not be prolonged to accomplish extensive internal fixation. Infection developed in three patients with internal fixation of the tibial fracture and one of these required amputation (Fig. 4). One patient with internal fixation of the tibia required amputation for ischemic muscle necrosis. More recently external fixators have facilitated good immobilization with minimal trauma. It has been our practice to perform the arterial repair before the skeletal fixation to reduce ischemia time. On only one occasion has the arterial repair required revision after the orthopedic procedure. Fasciotomy. The decision to perform fasciotomy has usually been made on clinical evidence of increased compartmental pressure, although we have used tissue pressure measurements in some patients. Twenty of the 58 patients who underwent arterial repair had a fasciotomy usually at the time of the repair and always after revascularization. Six of these patients required amputation because of muscle necrosis and gangrene. Six patients considered clinically to have tight compartments did not have fasciotomies, and none resulted in amputation; however, Table V. Results of repair No. Occlusions Amputations Deaths Direct anastomosis Vein graft 35 5 I 1 1 Prosthesis Lateral repair No repair Total four had some degree of muscle necrosis and loss of function. Thirty-eight patients did not have fasciotomy and seven of these required amputation. It is conceivable that some of these may have benefited from early fasciotomy. Of 41 patients discharged with a functioning limb, 11 had had a fasciotomy. Analysis of amputations. Five patients had primary amputations because the arterial injury was not recognized early enough to warrant attempts at reconstruction. In one patient, seen 4 days after injury, the arterial occlusion was demonstrated but thc collateral circulation was good (Fig. 5). Because of superficial infection, a decision was made to delay ar-

6 60 Downs and MacDonald Journal of" VASCULAR SURGERY Table VI. Interval from injury to operation No. Amputations % <6 hr hr >12 hr No repair Total % Fig. 5. Fractured tibial plateau and head of fibula with popliteal occlusion and good collateral circulation 4 days after injury. terial repair. Unfortunately, ischemic muscle necrosis and infection progressed and amputation was performed. It is conceivable that reconstruction performed 4 days after injury may have saved the limb. One patient with a prosthetic graft occlusion required amputation for gangrene. Six patients with patent vein graft repairs required amputation. In each of these patients, although the repair was technically successful and intraoperative angiography showed patency, there was no improvement in distal flow and amputation was necessary. All of these repairs were delayed more than 6 hours. This inability to achieve adequate distal flow in limbs that have undergone prolonged periods of ischemia has previously been observed by Connolly, Whittaker, and Williams. r The remaining patients who required amputation had occluded vein grafts. Four of these were considered technical failures and one resulted from infection. Interval from injury to operation. The interval from the injury to arterial repair is critical (Table VI). No amputations were necessary among 19 patients in whom repair was performed within 6 hours of injury. Although successful repair with complete recovery has been accomplished as late as 4 days after injury, this is exceptional and the need for early diagnosis and repair cannot be overemphasized. On the other hand, an arbitrary time limit cannot bc recommended and each case must be assessed on its own merits. Late results. Forty-one patients have been discharged from the hospital with functioning limbs and patent arterial repairs. All patients have been followed up from 12 months to 20 years. One patient with an end-to-end anastomosis had a stenosis 6 months after repair. A revision with a vein graft remains patent 10 years later. Varicosities in the lower leg have since dcveloped in one patient in whom the ipsilateral Popliteal vein was used for the arterial graft; however, no stasis changes have appeared in the 17-year interval since the injury. A 77-year-old patient had bilateral superficial femoral artery occlusions and occlusion of the vein graft repair of the popliteal artery 6 years after sustaining a knee dislocation. Two patients have suffered a talipes equinovarus deformity caused by muscle necrosis and contracture. Corrective ankle operations have been necessary to correct the deformities. One patient, treated with a vein bypass graft, required revision 6 months after repair for an iatrogenic entrapment and graft stenosis. DISCUSSION Popliteal artery occlusions associated with skeletal trauma caused by blunt injury continue to result in serious morbidity and high amputation rates. Delayed recognition of the arterial lesion is the major cause of these poor results. Our series includes 18 knee dislocations, most of which were reduced before the patient was admitted to the hospital. The magnitude of the injury and the potential for vascular disruption is frequently not suspected at the initial examination. This failure to recognize the knee dis-

7 Volume 4 Number 1 July 1986 Popliteal artery injuries 61 location has been previously emphasized by Kennedy.H The absence of pedal pulses and the presence of motor or sensory deficits demand immediate exclusion of an arterial injury either by angiography or by surgical exploration. When facilities are available, angiography is best performed in the operating room to avoid delay and to shorten the duration of ischemia. Capillary blood flow, frequently used as an index of circulatory adequacy, often leads to a false sense of security and unnecessary delay. Capillary filling is not a reliable sign in the determination of severe ischemia. The concomitant nerve injury in the popliteal fossa may lead to sympathetic denervation so that the minimal flow that is present via the collateral circulation is diverted to the skin of the foot. In our series, the upper tibial fracture has frequently been complicated by popliteal artery occlusion. As demonstrated by Kennedy, H the hyperextension force causing this type of injury may also cause a dislocation of the knee so that one may anticipate this complication. It is essential to suspect popliteal artery injury in all tibial fractures, but most particularly in those involving the upper tibial site. Muscle necrosis has been shown to occur after 6 hours of total ischemia? 2 There is little doubt that popliteal artery injury frequently produces almost complete distal ischemia because of the poor collateral circulation around the knee joint. In all probability, the traction injury causing the popliteal lesion also causes severe spasm in the collateral circulation as well as in the distal arteries. This severe ischemia must be reversed promptly to save the extremity. Our experience shows the favorable results obtained when revascularization is accomplished within 6 hours. Fasciotomy has been advocated by several authors as a necessary adjunct in the successful treatment of traumatic popliteal occlusions. 4,s'7'ls There is no doubt fasciotomy may improve muscle blood flow when there has been prolonged severe muscle ischemia with increased tissue pressure. However, fasciotomy may also contribute to morbidity as there was at least one amputation caused by severe infection in the ischemic necrotic muscle exposed by the fasciotomy in our series. Fasciotomy is indicated if there is an increased muscle compamnental pressure before or after arterial repair or if there is a deterioration in the circulation or in the neurologic deficit after a successful revascularization. The angiogram taken after repair, which is done routinely, may fail to show perfusion of the muscles and this is an indication for decompression. When fasciotomy is indicated, complete decompression should be accom- plished with medial and lateral incisions to decompress all compartments below the knee. Internal fixation may be necessary in patients in whom multiple fractures result in a flail limb, but in patients with isolated fractures this is rarely necessary. The increased risk of infection and prolonged ischemia accompanying internal fixation may jeopardize a successful outcome. 14 Venous repair should be performed when feasible and can usually be accomplished by direct anastomosis with adequate mobilization of the vein. The importance of vein repair has been emphasized by Sullivan et al.as and Rich et al.16 SUMMARY Our experience with 63 popliteal artery injuries has been reviewed. The single most important factor in successful management is early recognition and early repair. When repair is accomplished within 6 hours, the resuks are as good as those achieved with other arterial injuries. Dislocation of the knee is more common than frequently reported. Capillary-skin blood flow is not a reliable method of assessing the adequacy of the circulation. When a popliteal artery injury is suspected, it must be investigated immediately by angiography or exploration. External fixation is the preferred method of fracture immobilization. Fasciotomy should be performed when the muscle compartments are tight but is not required routinely. The popliteal vein should be adequately examined and repaired when injured. REFERENCES 1. Rich M, Baugh JH, Hughes CW. Popliteal artery injuries in Vietnam. Ann Surg 1969; 118: Hughes CW. Arterial repair during the Korean War. Ann Surg 1958; 147: Drapanas T, Hewitt RL, Weichert III RF, Smith AD. Civilian vascular injuries: A critical appraisal of three decades of management. Ann Surg 1970; 172: Snyder WH. Vascular injuries near the knee: An updated series and overview of the problem. Surgery 1982; 91: Lim LT, Michuda MS, Flanigan DP, Pankovich A. Popliteal artery trauma--31 consecutive cases without amputation. Arch Surg 1980; 115: Holleman JH, Killebrew LH. Injury to the popliteal artery. Surg Gynecol Obstet 1981; 153: Connolly JF, Whittaker D, Williams E. Femoral and tibial fractures combined with injuries to the femoral or popliteal artery. J Bone Joint Surg [Am] 1971; 53: Doty DB, Freiman RL, Rothschild PD, Gaspar MR. Prevention of gangrene due to fractures. Surg Gynecol Obstet 1967; 125: Hoover NW. Injuries of the popliteal artery associated with fractures and dislocations. Surg Clin North Am 1961; 41:

8 62 Downs and MacDonald Journal of VASCULAR SURGERY 10. Rich NM, Jarstfer BC, Geer TM. Popliteal arte~ repair failure: Cause and possible prevention. J Cardiovasc Surg 1974; 15: Kennedy JC. Complete dislocation of the knee joint. J Bonc Joint Surg [Am] 1963; 45: Miller HH, Welch CS. Quantitative studies of the time factor in arterial injuries. Ann Surg 1949; 130: Gorman JR. Combat arterial trauma: Analysis of 106 limbthreatening injuries. Arch Surg 1969; 98: Rich NM, Metz CW, Hutton JE, Baugh JH, Hughes CW. Internal versus external fixation of fractures with concomitant vascular injuries in Vietnam. J Trauma 1971; 11: Sullivan WG, Thornton FH, Baker LH, LaPlante ES, Cohen A. Early influence of popliteal vein repair in the treatment of popliteal vessel injuries. Am J Surg 1971; 122: Rich NM, Hobson RW, Collins GJ, Anderson CA. The effect of acute popliteal venous interruption. Ann Surg 1976; 183:365-8.