Blunt Popliteal Artery Injuries Vincent L. Rowe, Shahin Pourrabbani and Fred A. Weaver Blunt injury to the popliteal artery is commonly associated with trauma to the knee of sufficient force to result in either a knee dislocation or fracture. A review of 100 blunt popliteal artery injuries at our institution found that automobile collisions with pedestrians were the most common mechanism of blunt injury. A review of 100 blunt popliteal artery injuries at our institution found that the most common mechanisms of arterial injury were pedestrians being hit by automobiles, motorcycle accidents, and automobile accidents. Orthopedic injuries that included anterior or posterior knee dislocations and tibial plateau fractures were present in a third. Ischemia, manifested by neurologic deficit, cyanosis, or decreased temperature, affected two thirds of the injured patients. Despite these well-known associations, delays in diagnosis of politeal artery injury are common, treatment is often inadequate, and the consequences are often disastrous. Diagnosis Physical Examination A careful vascular examination is the key to the diagnosis of a popliteal artery injury. Unlike some patients with a popliteal artery injury caused by penetrating trauma who have an entirely normal vascular examination, patients with popliteal injuries secondary to blunt forces rarely do. In our experience, blunt popliteal artery injuries were associated with either an absent (94%) or diminished (4%) distal pulse. In a related series of 115 patients with knee dislocations, angiographically documented popliteal artery injuries affected 27 (23%) patients. An abnormal pedal pulse identified popliteal artery injuries with a sensitivity of 85% and specificity of 93%. All injuries that required intervention were associated with a diminished pulse. Dennis reported an identical experience in 37 patients with knee dislocations. All patients who required a popliteal repair had absent pedal pulses. More recently, Abou-Sayed and Berger confirmed the sensitivity of physical examination in 52 patients. Twenty-three patients, who had normal pulse examinations, did not undergo angiography and required no vascular intervention. Angiography was performed in 13 patients with normal pulse examinations (at the discretion of the attending surgeon), and no clinically significant lesions were identified that required intervention. A complete vascular examination should include an ankle-to-brachial index (ABI). In a study of 100 consecutive injured limbs, Lynch and Johanson showed that arterial injuries that required intervention were discovered in 14 cases, and an ABI less than 0.90 predicted the injury with 87% sensitivity and 97% specificity. A study at our own institution validated Lynch’s findings, although we found an ABI threshold of less than 1.0 more precise in predicting the presence of an arterial injury. Thus, ABI has become a routine part of the vascular assessment of the injured extremity, and ABI less than 0.9 to 1.0 warrants further investigation for the presence of an arterial injury, even when the pulse examination is reported to be normal. Because of the close proximity of major nerves to the popliteal vessels, a thorough neurologic examination is critical. In the popliteal area, the close proximity of major nerves has led to an incidence of associated nerve injuries between 8% and 58%. Nerve injuries result in severe long-term neurologic deficits in up to 20% of patients and are a key determinant in subsequent limb function. Imaging Plain radiographs are part of a standard diagnostic evaluation for a trauma patient. In patients with blunt trauma, fractures or dislocations in key anatomic areas, such as a posterior knee dislocation, can alert the surgeon to the possibility of a vascular injury. In patients who come to the hospital with obvious deformities, bony injuries are easily appreciated. However, even the most minor-appearing injured extremity can harbor an occult bony disruption. Christian identified unrecognized arterial injuries in 50% of patients who come to the hospital with severe tibial fractures. Therefore, a series of plain radiographs to ensure the absence of a fracture is obligatory in the evaluation of lower extremity trauma. Digital angiography is being replaced by computed tomography angiography (CTA) in the diagnosis of vascular extremity trauma. When compared to digital angiography for trauma patients, CTA has the distinct advantage of being equivalent in accuracy, more time efficient, less invasive, and less expensive. Current CT scanning is also readily available and provides simultaneous imaging of the head, neck, chest and abdomen as well as surrounding extremity structures and adjacent anatomy in a single examination. Soto and colleagues performed one of the early comparisons between CTA and digital angiography for evaluation of suspected vascular injuries. In this study, all extremity trauma patients referred for digital angiography underwent CTA. Two independent observers documented sensitivity and specificity levels greater than 90% for diagnosis of vascular injuries, with an interobserver agreement of 0.9 (kappa coefficient). In selected circumstances, digital angiographic confirmation of the popliteal artery injury is helpful in planning the arterial repair. A digital angiogram can provide a more precise localization of the injury, a better visualization of occlusion length and which infrapopliteal vessels are involved, and a more accurate assessment of distal thrombus and the presence of a second, more distal injury. When evaluating either CTA or digital angiographic images, the surgeon must not be trapped into misdiagnosing a short segmental narrowing of the artery as “spasm” and assume that the lesion will spontaneously resolve. Such lesions usually represent intramural hemorrhage or other forms of vessel wall injury that can progress to total occlusion. Vasospasm can occur but is usually seen as a long, smooth narrowing of an otherwise patent vessel, or there may be multiple areas of beading in a vessel with smooth, intact intima. These findings suggesting external compression may also be seen in patients with increased compartment pressures and should alert the surgeon that the compartment pressures must be assessed. Treatment Vascular Repair Once the diagnosis of a popliteal artery injury is made, definitive repair should be performed as expeditiously as possible. Operative intervention without delay is critical in patients with suspected popliteal artery injury who arrive in the emergency department with profound clinical evidence of arterial ischemia (absent pedal pulses, significant neurologic compromise). Any delay in taking the patient to the operating room in order to obtain a CTA or digital angiogram in the radiology suite is unwarranted. Angiographic assessment can be accomplished in the operating room with an on-table study at the time of operative intervention. Many authors have suggested that the elapsed time between injury and revascularization is the most important factor in limb survival. However, in our experience, time delay did not correlate with limb loss, mainly because limbs with the most severe injury and most profound ischemia underwent operative repair much sooner than those without significant ischemia. The magnitude of the injury rather than the time to repair was the factor associated with limb loss. Temporary intraluminal shunting may also be of value for some injuries when the limb is severely ischemic and revascularization is delayed because of fracture fixation, complex soft tissue injury, or associated life–threatening injuries. This technique allows early restoration of limb perfusion, which lessens the likelihood of ischemic damage and distal thrombosis. Débridement, fasciotomy, fracture fixation, neurorrhaphy, or vein repair can then be performed in a deliberate and unhurried fashion, before arterial reconstruction. Rasmussen reported on the military’s experience over 1 year during Operation Iraqi Freedom. Shunt patency varied based on location, being 86% when proximal (above the elbow or knee) and 12% when distal (below the elbow or knee). Most shunts were in place for less than 2 hours, but patency was noted in proximally placed shunts of up to 18 hours without systemic heparin. Other investigators have documented shunt patency for more than 3 hours without systemic heparinization. The popliteal artery is usually repaired using the traditional medial approach. This approach permits extension of the incision proximally or distally, depending on the extent of the injury. The alternative posterior approach to the popliteal artery does not provide adequate exposure for complex injuries and is not recommended for trauma patients. To help reduce blood loss, a sterile pneumatic tourniquet at the thigh may be used to rapidly establish proximal control in the actively bleeding extremity or during the dissection and popliteal repair. The opposite leg should be prepared in all instances in case the saphenous vein is needed for a bypass. Vein should not be harvested from the injured leg. If both legs are injured, cephalic or basilic vein can be used for a conduit. Synthetic grafts have been used successfully for traumatic injuries in multiple anatomic sites; however, for politeal artery repairs, autogenous vein should be used for arterial reconstruction. Early systemic anticoagulation should be used in all patients in whom there is no associated intracranial, intrathoracic, or intraabdominal injury that would preclude its use. If systemic anticoagulation is contraindicated, regional heparin administration with the tourniquet inflated might confer some benefit. In our series, the amputation rate was significantly lower when systemic heparin therapy was used (8% vs. 31%, p < .01). Presumably, systemic heparin administration prevented clot formation distal to the occlusive injury. Small vessel thrombosis was a major factor in half our patients who ultimately required amputation. Once small vessel clotting occurs, it may be impossible to remove or flush existing thrombus, and therefore heparin administration should be started as soon as feasible once the diagnosis of a popliteal artery injury is made. All traumatized arterial wall should be débrided. Portions of artery with disrupted intima should be débrided rather than tacking the intima down. Fogarty thrombectomy catheters should be passed gently proximally and distally to remove any thrombus that may have formed or embolized. Overinflation of the balloon can result in intimal disruption or produce protracted, intense vasospasm in these highly compliant muscular arteries. Primary repair of the popliteal artery is advised whenever possible, even if it means sacrificing selected geniculate collateral vessels to mobilize sufficient artery to fashion a tension-free anastomosis. These small collateral vessels are not likely to be important in a nonatherosclerotic, acutely traumatized artery. Interposition vein grafts are necessary to bridge larger defects, particularly when the trifurcation is involved. With trifurcation injuries, bypass to the tibioperoneal trunk and ligation or implantation of the anterior tibial artery to the side of the graft is preferred. Primary vascular repair is achieved either by trifurcating the anastomosis with interrupted sutures or by running a suture around the posterior half of the vessel and using interrupted sutures anteriorly. The latter is suggested in patients with small arteries and in growing children. Saphenous vein should be harvested from the opposite leg, with the proximal vein being preferred. The vein is reversed and the anastomoses are completed with 5–0 or 6–0 monofilament suture. All arterial repairs should undergo an on-table completion angiogram or duplex scan, even with a palpable distal pulse. Technical problems, anastomotic narrowing, intimal flaps, and distal thrombus should be immediately corrected. If severe vasospasm is present, an infusion of 50 to 100 mg of tolazoline can be used to relieve the spasm. Endovascular repairs have been used in numerous vascular beds following vascular injury. However, reports are scarce for catheter-based treatment of blunt popliteal arterial injuries. One third of the patients with these arterial injuries have an associated popliteal vein injury. If venous continuity is not restored, leg edema and compartmental hypertension increase, deleterious effects that can lead to occlusion of the arterial repair. Historically, ligated venous injuries were associated with higher amputation rates; therefore, whenever possible, the venous injury should be repaired. Repair can be achieved by lateral repair, primary repair, or a venous interposition graft. The goal of venous repair is to maintain early patency to augment venous return in the early postoperative period while collateral venous channels develop. Thrombosis of the venous repair can subsequently occur but is usually asymptomatic if collateral channels have developed. The risk of developing acute thrombosis at the site of repair with subsequent pulmonary embolism does exist. This risk can be minimized by dextran or heparin sodium in the early postoperative period. Fasciotomy The need for fasciotomy following successful repair of the popliteal artery is an area of continuing controversy. Since the popliteal artery is in essence an end artery, profound muscle ischemia is possible with only brief periods (>4–6 hr) of warm ischemia. Our approach is to selectively perform fasciotomy depending on the length of warm ischemia, concomitant popliteal venous injury, and associated orthopedic and soft tissue injury. If fasciotomy is required, a complete four-compartment fasciotomy through a two-incision approach is recommended. Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Technical Aspects of Percutaneous Carotid Angioplasty and Stenting for Arteriosclerotic Disease In-Situ Treatment of Aortic Graft Infection with Prosthetic Grafts and Allografts Treatment of Acute Upper Extremity Venous Occlusion Intraoperative Assessment of the Technical Adequacy of Carotid Endarterectomy Stay updated, free articles. Join our Telegram channel Join Tags: Current Therapy in Vascular and Endovascular Surgery Jul 15, 2018 | Posted by admin in CARDIOLOGY | Comments Off on Blunt Popliteal Artery Injuries Full access? Get Clinical Tree
Blunt Popliteal Artery Injuries Vincent L. Rowe, Shahin Pourrabbani and Fred A. Weaver Blunt injury to the popliteal artery is commonly associated with trauma to the knee of sufficient force to result in either a knee dislocation or fracture. A review of 100 blunt popliteal artery injuries at our institution found that automobile collisions with pedestrians were the most common mechanism of blunt injury. A review of 100 blunt popliteal artery injuries at our institution found that the most common mechanisms of arterial injury were pedestrians being hit by automobiles, motorcycle accidents, and automobile accidents. Orthopedic injuries that included anterior or posterior knee dislocations and tibial plateau fractures were present in a third. Ischemia, manifested by neurologic deficit, cyanosis, or decreased temperature, affected two thirds of the injured patients. Despite these well-known associations, delays in diagnosis of politeal artery injury are common, treatment is often inadequate, and the consequences are often disastrous. Diagnosis Physical Examination A careful vascular examination is the key to the diagnosis of a popliteal artery injury. Unlike some patients with a popliteal artery injury caused by penetrating trauma who have an entirely normal vascular examination, patients with popliteal injuries secondary to blunt forces rarely do. In our experience, blunt popliteal artery injuries were associated with either an absent (94%) or diminished (4%) distal pulse. In a related series of 115 patients with knee dislocations, angiographically documented popliteal artery injuries affected 27 (23%) patients. An abnormal pedal pulse identified popliteal artery injuries with a sensitivity of 85% and specificity of 93%. All injuries that required intervention were associated with a diminished pulse. Dennis reported an identical experience in 37 patients with knee dislocations. All patients who required a popliteal repair had absent pedal pulses. More recently, Abou-Sayed and Berger confirmed the sensitivity of physical examination in 52 patients. Twenty-three patients, who had normal pulse examinations, did not undergo angiography and required no vascular intervention. Angiography was performed in 13 patients with normal pulse examinations (at the discretion of the attending surgeon), and no clinically significant lesions were identified that required intervention. A complete vascular examination should include an ankle-to-brachial index (ABI). In a study of 100 consecutive injured limbs, Lynch and Johanson showed that arterial injuries that required intervention were discovered in 14 cases, and an ABI less than 0.90 predicted the injury with 87% sensitivity and 97% specificity. A study at our own institution validated Lynch’s findings, although we found an ABI threshold of less than 1.0 more precise in predicting the presence of an arterial injury. Thus, ABI has become a routine part of the vascular assessment of the injured extremity, and ABI less than 0.9 to 1.0 warrants further investigation for the presence of an arterial injury, even when the pulse examination is reported to be normal. Because of the close proximity of major nerves to the popliteal vessels, a thorough neurologic examination is critical. In the popliteal area, the close proximity of major nerves has led to an incidence of associated nerve injuries between 8% and 58%. Nerve injuries result in severe long-term neurologic deficits in up to 20% of patients and are a key determinant in subsequent limb function. Imaging Plain radiographs are part of a standard diagnostic evaluation for a trauma patient. In patients with blunt trauma, fractures or dislocations in key anatomic areas, such as a posterior knee dislocation, can alert the surgeon to the possibility of a vascular injury. In patients who come to the hospital with obvious deformities, bony injuries are easily appreciated. However, even the most minor-appearing injured extremity can harbor an occult bony disruption. Christian identified unrecognized arterial injuries in 50% of patients who come to the hospital with severe tibial fractures. Therefore, a series of plain radiographs to ensure the absence of a fracture is obligatory in the evaluation of lower extremity trauma. Digital angiography is being replaced by computed tomography angiography (CTA) in the diagnosis of vascular extremity trauma. When compared to digital angiography for trauma patients, CTA has the distinct advantage of being equivalent in accuracy, more time efficient, less invasive, and less expensive. Current CT scanning is also readily available and provides simultaneous imaging of the head, neck, chest and abdomen as well as surrounding extremity structures and adjacent anatomy in a single examination. Soto and colleagues performed one of the early comparisons between CTA and digital angiography for evaluation of suspected vascular injuries. In this study, all extremity trauma patients referred for digital angiography underwent CTA. Two independent observers documented sensitivity and specificity levels greater than 90% for diagnosis of vascular injuries, with an interobserver agreement of 0.9 (kappa coefficient). In selected circumstances, digital angiographic confirmation of the popliteal artery injury is helpful in planning the arterial repair. A digital angiogram can provide a more precise localization of the injury, a better visualization of occlusion length and which infrapopliteal vessels are involved, and a more accurate assessment of distal thrombus and the presence of a second, more distal injury. When evaluating either CTA or digital angiographic images, the surgeon must not be trapped into misdiagnosing a short segmental narrowing of the artery as “spasm” and assume that the lesion will spontaneously resolve. Such lesions usually represent intramural hemorrhage or other forms of vessel wall injury that can progress to total occlusion. Vasospasm can occur but is usually seen as a long, smooth narrowing of an otherwise patent vessel, or there may be multiple areas of beading in a vessel with smooth, intact intima. These findings suggesting external compression may also be seen in patients with increased compartment pressures and should alert the surgeon that the compartment pressures must be assessed. Treatment Vascular Repair Once the diagnosis of a popliteal artery injury is made, definitive repair should be performed as expeditiously as possible. Operative intervention without delay is critical in patients with suspected popliteal artery injury who arrive in the emergency department with profound clinical evidence of arterial ischemia (absent pedal pulses, significant neurologic compromise). Any delay in taking the patient to the operating room in order to obtain a CTA or digital angiogram in the radiology suite is unwarranted. Angiographic assessment can be accomplished in the operating room with an on-table study at the time of operative intervention. Many authors have suggested that the elapsed time between injury and revascularization is the most important factor in limb survival. However, in our experience, time delay did not correlate with limb loss, mainly because limbs with the most severe injury and most profound ischemia underwent operative repair much sooner than those without significant ischemia. The magnitude of the injury rather than the time to repair was the factor associated with limb loss. Temporary intraluminal shunting may also be of value for some injuries when the limb is severely ischemic and revascularization is delayed because of fracture fixation, complex soft tissue injury, or associated life–threatening injuries. This technique allows early restoration of limb perfusion, which lessens the likelihood of ischemic damage and distal thrombosis. Débridement, fasciotomy, fracture fixation, neurorrhaphy, or vein repair can then be performed in a deliberate and unhurried fashion, before arterial reconstruction. Rasmussen reported on the military’s experience over 1 year during Operation Iraqi Freedom. Shunt patency varied based on location, being 86% when proximal (above the elbow or knee) and 12% when distal (below the elbow or knee). Most shunts were in place for less than 2 hours, but patency was noted in proximally placed shunts of up to 18 hours without systemic heparin. Other investigators have documented shunt patency for more than 3 hours without systemic heparinization. The popliteal artery is usually repaired using the traditional medial approach. This approach permits extension of the incision proximally or distally, depending on the extent of the injury. The alternative posterior approach to the popliteal artery does not provide adequate exposure for complex injuries and is not recommended for trauma patients. To help reduce blood loss, a sterile pneumatic tourniquet at the thigh may be used to rapidly establish proximal control in the actively bleeding extremity or during the dissection and popliteal repair. The opposite leg should be prepared in all instances in case the saphenous vein is needed for a bypass. Vein should not be harvested from the injured leg. If both legs are injured, cephalic or basilic vein can be used for a conduit. Synthetic grafts have been used successfully for traumatic injuries in multiple anatomic sites; however, for politeal artery repairs, autogenous vein should be used for arterial reconstruction. Early systemic anticoagulation should be used in all patients in whom there is no associated intracranial, intrathoracic, or intraabdominal injury that would preclude its use. If systemic anticoagulation is contraindicated, regional heparin administration with the tourniquet inflated might confer some benefit. In our series, the amputation rate was significantly lower when systemic heparin therapy was used (8% vs. 31%, p < .01). Presumably, systemic heparin administration prevented clot formation distal to the occlusive injury. Small vessel thrombosis was a major factor in half our patients who ultimately required amputation. Once small vessel clotting occurs, it may be impossible to remove or flush existing thrombus, and therefore heparin administration should be started as soon as feasible once the diagnosis of a popliteal artery injury is made. All traumatized arterial wall should be débrided. Portions of artery with disrupted intima should be débrided rather than tacking the intima down. Fogarty thrombectomy catheters should be passed gently proximally and distally to remove any thrombus that may have formed or embolized. Overinflation of the balloon can result in intimal disruption or produce protracted, intense vasospasm in these highly compliant muscular arteries. Primary repair of the popliteal artery is advised whenever possible, even if it means sacrificing selected geniculate collateral vessels to mobilize sufficient artery to fashion a tension-free anastomosis. These small collateral vessels are not likely to be important in a nonatherosclerotic, acutely traumatized artery. Interposition vein grafts are necessary to bridge larger defects, particularly when the trifurcation is involved. With trifurcation injuries, bypass to the tibioperoneal trunk and ligation or implantation of the anterior tibial artery to the side of the graft is preferred. Primary vascular repair is achieved either by trifurcating the anastomosis with interrupted sutures or by running a suture around the posterior half of the vessel and using interrupted sutures anteriorly. The latter is suggested in patients with small arteries and in growing children. Saphenous vein should be harvested from the opposite leg, with the proximal vein being preferred. The vein is reversed and the anastomoses are completed with 5–0 or 6–0 monofilament suture. All arterial repairs should undergo an on-table completion angiogram or duplex scan, even with a palpable distal pulse. Technical problems, anastomotic narrowing, intimal flaps, and distal thrombus should be immediately corrected. If severe vasospasm is present, an infusion of 50 to 100 mg of tolazoline can be used to relieve the spasm. Endovascular repairs have been used in numerous vascular beds following vascular injury. However, reports are scarce for catheter-based treatment of blunt popliteal arterial injuries. One third of the patients with these arterial injuries have an associated popliteal vein injury. If venous continuity is not restored, leg edema and compartmental hypertension increase, deleterious effects that can lead to occlusion of the arterial repair. Historically, ligated venous injuries were associated with higher amputation rates; therefore, whenever possible, the venous injury should be repaired. Repair can be achieved by lateral repair, primary repair, or a venous interposition graft. The goal of venous repair is to maintain early patency to augment venous return in the early postoperative period while collateral venous channels develop. Thrombosis of the venous repair can subsequently occur but is usually asymptomatic if collateral channels have developed. The risk of developing acute thrombosis at the site of repair with subsequent pulmonary embolism does exist. This risk can be minimized by dextran or heparin sodium in the early postoperative period. Fasciotomy The need for fasciotomy following successful repair of the popliteal artery is an area of continuing controversy. Since the popliteal artery is in essence an end artery, profound muscle ischemia is possible with only brief periods (>4–6 hr) of warm ischemia. Our approach is to selectively perform fasciotomy depending on the length of warm ischemia, concomitant popliteal venous injury, and associated orthopedic and soft tissue injury. If fasciotomy is required, a complete four-compartment fasciotomy through a two-incision approach is recommended. Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Technical Aspects of Percutaneous Carotid Angioplasty and Stenting for Arteriosclerotic Disease In-Situ Treatment of Aortic Graft Infection with Prosthetic Grafts and Allografts Treatment of Acute Upper Extremity Venous Occlusion Intraoperative Assessment of the Technical Adequacy of Carotid Endarterectomy Stay updated, free articles. Join our Telegram channel Join Tags: Current Therapy in Vascular and Endovascular Surgery Jul 15, 2018 | Posted by admin in CARDIOLOGY | Comments Off on Blunt Popliteal Artery Injuries Full access? Get Clinical Tree
