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Vascular trauma
Vascular
Vascular trauma Nigel Tai John P Raj Michael Walsh
Abstract This contribution discusses the basic concepts of vascular trauma.
Keywords blunt injury; penetrating injury; blast injury; intimal injury; arterial spasm; duplex ultrasonography; digital subtraction angiography
Mechanism of injury
a
Blunt injury can disrupt vessels directly (Figure 1) after a crush or indirectly after disruption to tissues injured at some distance from the point of impact. Fractures of long bones and joint dislocations may impinge bone ends onto the vessel. Penetrating injuries to vessels after knife wounds or low-energy bullet wounds may be partial or complete, depending on missile trajectory. High-energy transfer wounds cause massive local vascular disruption, directly or by transfer of energy from nearby bony injury. Blast injury (see Garner, CROSS REFERENCE) is the damage caused by the consequences of explosive detonation, and may involve blunt and penetrating mechanisms. Vessels may be damaged by the blast wave, by secondary fragments (shrapnel) or by the blast wind, causing bodily displacement.
b a Radiograph showing severe humeral disruption of the left arm (arrow) after impact with a tube train. b Angiogram showing an associated vascular injury (arrow).
Iatrogenic injuries: blood vessels may be damaged during surgery, radiological procedures or when obtaining access to the circulation. After injury, further damage may be caused during exploratory surgery.
Figure 1
Types of vascular injuries Vessel disruption is the commonest vascular injury and may be partial or complete. Partial disruptions usually cause active bleeding if an open wound is close to the disruption. It may present as an expanding or pulsatile haematoma (Figure 2). Partial disruptions may not present with ischaemia because a channel for blood flow can be maintained. False aneurysms may develop if a partial disruption is unrecognized. Complete disruptions usually present with haemorrhage, which decreases as the vessel goes into spasm and a clot develops (Figure 3).
This article was first published in Surgery 2004; 22(11): 288–93. Nigel Tai FRCS is a Specialist Registrar in Trauma and Vascular Surgery at Bart’s and the London NHS Trust, London, UK. Conflicts of interest: none declared. John P Raj MS(Gen) is a Consultant General Surgeon at Christian Medical College, Vellore, India. Conflicts of interest: none declared.
Intimal injuries are the second commonest type of vascular injury and may lead to thrombosis of the vessel or the formation of an intimal flap, progressing to distal ischaemia. Occasionally, an intimal flap may cause a dissection, which extends with time and may become apparent later.
Michael Walsh FRCS is a Consultant Vascular and Trauma Surgeon at Bart’s and the London NHS Trust, London, UK. Conflicts of interest: none declared.
SURGERY 25:8
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© 2007 Elsevier Ltd. All rights reserved.
Vascular
Arteriovenous fistula formation occurs if an artery and its adjacent vein are injured. They are commonly seen after penetrating trauma and tend to present late.
Classification of vascular injuries and their sequelae Incomplete transection
Arterial spasm is rare and should not be considered as the cause of limb ischaemia after trauma.
Pulsatile haematoma Rupture Delayed haemorrhage Thrombus Embolism False aneurysm Arteriovenous fistula
Diagnosis Clinical Diagnosis can be difficult and requires a high degree of suspicion and careful evaluation. The clinical features associated with vascular injury are divided into ‘hard’ signs and ‘soft’ signs (Table 1). Hard signs indicate vascular injury that requires attention; soft signs are suggestive of vascular injury and mandate further evaluation. Vascular injuries can also present with very little clinical evidence to suggest injury. The incidence of occult injuries to vessels close to a penetrating injury is about 20%.
Complete transection
Transection with spasm of the vessel Distal ischaemia Pulse deficit
Imaging Duplex ultrasonography is a non-invasive method that can detect arterial disruption, thrombosis, false aneurysms and arteriovenous fistulae. It is operator-dependent and has a diagnostic accuracy of >90%.
Closed injuries
Bone
Compression between bone fragments
Contrast-enhanced CT is a useful tool to evaluate injuries of the great vessels. It is becoming the first-line investigation for evaluating thoracic aortic injuries. CT should be reserved for the haemodynamically stable.
OR
Stretch
Digital subtraction angiography (Figure 4) is the first-line investigation for evaluating arterial injuries. Interventional radiological techniques may be used for treatment in certain circumstances (e.g. stenting of intimal flaps and partial disruptions). In actively bleeding injuries, on-table angiography can be done when bleeding is controlled.
Thrombosis Intimal tear and flap causing dissection, or occlusion Subintimal haematoma causing occlusion
Management Figure 2
Attention should first be paid to the airway and the breathing before the circulation is addressed (Figure 5). Haemorrhage control Direct pressure is the safest and most effective way of controlling external bleeding. Surgical exploration is urgently needed if bleeding is not controlled.
Clinical signs associated with a vascular injury
Figure 3 Angiogram showing transaction of the external carotid artery (arrow) due to a stab injury. Extravasation of contrast is absent because a clot has developed.
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‘Hard’ signs
‘Soft’ signs
Pulseless, cold, pale limb Expanding haematoma
History of active bleeding Penetrating injury in close proximity to a major vessel Non-expanding haematoma Neurological deficit
Palpable thrill or an audible bruit Active bleeding Table 1
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© 2007 Elsevier Ltd. All rights reserved.
Vascular
Management of vascular injuries Trauma Assessment with attention to airway and breathing first Haemodynamic instability or obvious external haemorrhage Yes
No
Immediate exploration Direct pressure over bleeding point for temporary control Consider arterial embolization for pelvic fractures
Present
Digital subtraction angiography followed by surgery On-table angiogram during surgery
Figure 4 Digital subtraction angiogram showing an arteriovenous fistula (arrow) between the right subclavian artery and vein after a gunshot wound to the chest.
Inflating the balloon of a Foley catheter in the track of a neck wound may tamponade bleeding. Penetrating injuries at the root of the neck often bleed into the thoracic cavity and two Foley catheters may be needed to obtain control. The first is inserted into the wound to reach the pleural cavity. The balloon is inflated and the catheter is pulled back to tamponade the injury from below. The second catheter is placed into the wound track and the balloon inflated to complete the control. Catastrophic intraabdominal bleeding may be controllable only by laparotomy or left thoracotomy with crossclamping of the thoracic aorta. Interventional radiology may be used to control bleeding by balloon tamponade (Figure 6) or embolization. Balloon cath eters (inserted via a remote vessel and deployed upstream of an injured vessel) can provide proximal control of haemorrhage in the Emergency Department before transfer to theatre for definitive surgery. Image intensification is not needed because the site of balloon deployment can be determined by monitoring the ar terial pressure waveform as the catheter is ‘floated’ into position. Coil embolization has a role in haemorrhage control of bleeding branches of the internal iliac artery after pelvic fractures and may be undertaken as part of the ‘circulation’ stage of the primary survey.
Not present
Soft signs (see Table 1)
Present
Not present
Duplex ultrasonography measure ABPI if not available
Vascular injury or ABPI <1
No injury shown, ABPI >1
Observe
ABPI: Ankle–brachial pressure index
Figure 5
Surgical repair of arterial and venous injuries Preparation of the vessel: fractures and dislocations should be reduced and fixed before undertaking vascular repair. The entire injured extremity and an uninjured lower limb should be prepared in case an autogenous vein graft is needed. Proximal and distal control of the blood vessels is obtained by exposing a generous length of the vessel either side of the injury and placing silastic slings or tapes around the vessel proximal and distal to the injury. If arterial clamps are used to obtain control, apply enough pressure to achieve occlusion to minimize the risk of
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Hard signs (see Table 1)
Figure 6 Angioplasty balloon sited in the subclavian artery before surgical exploration in a patient with disruption to the axillary artery. Contrast extravasation is due to collateral backflow distal to the balloon.
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© 2007 Elsevier Ltd. All rights reserved.
Vascular
intimal damage. The aorta should be clamped because occlusion with a sling is inappropriate. Intra-arterial balloon occlusion catheters may be used to obtain control in difficult circumstances. The vessel is debrided and trimmed. Intimal flaps can be sutured down using longitudinal interrupted 6/0 sutures. A balloon embolectomy catheter is passed proximally and distally to clear intraluminal thrombi and to ensure that inflow and run-off are satisfactory. On-table angiography should be used to identify occult injuries and remaining thrombi. Once the vessel is clear, intra-arterial heparin (5000 units per 500 ml saline solution) is injected proximally and distally to prevent further thrombosis.
sufficient calibre to replace vessels up to the superficial femoral artery in size. If a vein is not available, prosthetic grafts made out of expanded polytetrafluoroethylene are used because they are resistant to infection.
Lateral suture is used for closing simple lacerations in mediumand large-sized vessels and transverse lacerations in smaller arteries (Figure 7a). Interrupted or continuous sutures are placed through the entire thickness of the vessel wall. A patch angioplasty is required if the vessel is likely to become narrowed using this technique.
Endovascular treatment of vascular trauma (particularly if vessel exposure is technically difficult or if there is significant comorbidity) is increasing in use. Covered stents may be inserted percutaneously or via open ar teriotomies, manoeuvred into position under radiographic guidance and used to restore integrity to punctured vessels such as the vertebral, subclavian, axillary, carotid and iliac arteries. Stent repair for the treatment of traumatic disruption of the thoracic aorta is preferential to open repair because cardiac bypass is avoided. Advantages include: • less invasive • procedure is quicker • less blood is lost • less anaesthesia is needed. The disadvantages of such techniques are well described. • Intravascular prostheses may be malpositioned, embolize, thrombose or suffer structural failure. • Endoleak can occur and there is potential for contamination and infection of stents in penetrating trauma. • Out-of-hours availability of a dedicated angiography suite plus attendant interventional radiologist is a prerequisite that few UK
Bypass procedures should be considered in complex vascular injuries (Figure 8) and after ligation of major arteries. Severely contaminated wounds or large loss of soft tissue may also require an extra-anatomical bypass to ensure graft cover, avoid graft infection and maintain the circulation. The conduit depends on the circumstances and the vessels involved.
Vein patch angioplasty (Figure 7b) is used for closing longitudinal lacerations in smaller vessels. A suitable piece of vein culled from nearby subcutaneous tissue can be used. An end-to-end anastomosis is required to restore continuity to transected vessels. The ends of the vessel should be cut obliquely (Figure 7c) to reduce the risk of stenosis. The vessel ends should be approximated without undue tension. The anastomosis is carried out using interrupted or continuous sutures. Stay stitches inserted at two or three equal intervals prevent pursestringing and subsequent stenosis if the continuous method is used. An interposition graft is used if vessel ends cannot be approximated without tension. A reversed long saphenous vein is of
Closing arterial lacerations
Vein patch
a Closure of an incomplete tear directly with a simple suture
b Closure of a large longitudinal tear with a vein patch
c Repair of a complete transection (see Figure 2) using a three-point stay suture with a continuous suture for the anastamosis
Figure 7
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© 2007 Elsevier Ltd. All rights reserved.
Vascular
be anticipated and fasciotomies done. Amputation should be the definitive procedure in the event of irreversible ischaemia of the limb after damage control.
Complications of vascular injuries The repair of vascular injuries depends on prompt diagnosis and management of other life-threatening injuries (Table 2). Delays in diagnosis may lead to the complications discussed below. False aneurysms A false aneurysm (Figure 9) develops if there has been a partial disruption to the vessel, which continues to bleed into a contained haematoma. False aneurysms are more common in pen etrating and iatrogenic injuries (see below). False aneurysms may be treated using ultrasound-guided pressure or by injection of thrombin into the lumen of the false aneurysm. Surgery should be done if this does not succeed.
Figure 8 Surgical repair of a degloved thigh and disrupted superficial femoral artery and vein after a crush injury caused by a lorry. The distal popliteal artery is controlled by a sling (black arrow). An expanded polytetrafluoroethylene graft (green arrow) was used for reconstruction.
Arteriovenous fistulae Arteriovenous fistulae are seen in penetrating injuries. They present late, with a pulsatile mass and a palpable thrill. Surgery involves disconnecting the fistula and produces good results.
hospitals can boast, and the time lost summoning personnel and equipment may expose the patient to additional hazard. • There is a large body of evidence describing the durability of a well-conducted surgical operation, but the endovascular series emanating from most trauma centres are small and with limited follow-up.
Compartment syndrome A compartment syndrome occurs if the pressure within the muscular compartments of the limbs rises to >30 mmHg. It is caused by a reperfusion injury after ischaemia. It is more common in patients who have: • had prolonged periods of hypotension • arterial occlusion • a combined arterial and venous injury • had a vein ligated • had a severe crush injury. The increased pressure is relieved by a fasciotomy which lays open the entire fascial envelope of the muscle compartment along with the overlying skin. If a fasciotomy is not done at the time of the surgery, compartment pressures should be measured and fasciotomies carried out if pressures are >30 mmHg.
Damage control Damage control should be considered in patients who have multiple injuries with gross physiological derangements. Damage control allows time for resuscitation, stabilization and investigation before definitive repair. The aims are to control bleeding and to maintain circulation by simple measures. Damage control may be achieved by shunting, ligation or packing. Shunting to restore blood flow to a limb is the preferred damage control manoeuvre and is also indicated if prolonged orthopaedic stabilization is required before vascular repair. If venous and arterial injuries coexist, both should be shunted. In addition to commercially available shunts, sterile infant feeding tubes, nasogastric tubes and chest drains can been used as temporary shunts. The major complications are dislodgement and occlusion of the shunt.
Amputation Amputation of the affected limb may be the first-line treatment in limbs where there are signs of irreversible ischaemia, extensive
Ligation: the external carotid, subclavian arteries in their second part, and the internal iliac arteries can be ligated with minimal sequelae. In an emergency, the common and internal carotid arteries can be ligated with a good chance of neurological recovery. Ligation of the major limb arteries is likely to lead to significant limb ischaemia requiring open fasciotomies. Ligation can be carried out on all limb veins and the inferior vena cava at the cost of limb oedema. The jugular veins can be ligated without major problems.
Poor prognostic factors that affect the outcome of vascular repairs Delays in treatment of >6 hours Blunt injuries An absent Doppler ultrasound signal in the vessel at admission Clinical presentation with ischaemia Other associated injuries that require immediate attention Injury to lower extremities (particularly injuries of the popliteal artery) Chronic ischaemia of the limb
Packing controls major arterial bleeds poorly, but may be used to control venous bleeds. It is particularly useful for vascular injuries of the pelvis and the retrohepatic inferior vena cava. A definitive procedure to restore blood supply should take place when the patient has stabilized. Reperfusion injury should
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Table 2
331
© 2007 Elsevier Ltd. All rights reserved.
Vascular
varieties require fibrin glue or surgery. Limb ischaemia may result from an intimal flap or dissection after angioplasty. Vessel rupture is rare, but is seen occasionally after angioplasty of external iliac artery disease; the resultant extensive bleeding may threaten life. Temporary vascular control can be obtained with a proximal balloon while preparations are made for surgery or the insertion of a covered stent. The treatment plan must consider comorbidity (e.g. diabetes, heart and renal disease) and the poor physiological reserve of these patients. The surgical options are guided by the • disease state of native vessels • necessity to preserve collateral supply • possible lack of suitable vein for bypass • amount of in-flow and run-off. Surgery to correct such injuries is associated with a mortality of about 10%, emphasizing postoperative care in the ICU or HDU.
Venous injuries
Figure 9 False aneurysm of the suprarenal artery (arrow) after a stab injury.
The veins that are usually injured are the superficial femoral (42%), popliteal (23%) and common femoral (14%). Venous injuries should be treated using similar techniques to arterial injuries and repaired wherever possible unless the patient is haemodynamically unstable and the injuries are complex. In this situation, ligation of the vessel followed by elevation of the extremities is appropriate.
damage to soft tissue or extensive neurological damage. Amputations are more likely if there have been delays in recognizing vascular injury, in injuries involving the popliteal artery and crural vessels, and if there have been delays in resuscitation. Iatrogenic vascular trauma Blood vessels may be damaged by orthopaedic, abdominal or gynaecological misadventure, but iatrogenic trauma is usually due to percutaneous introduction of vascular catheters used to diagnose or treat cardiovascular disease. Damage may occur locally at the site of the vessel selected for access, at the site of intervention or anywhere in between. The common femoral artery is the most common site of trauma. Arteriovenous fis tulae, intimal disruption, vessel thrombosis, rupture, acute limb ischaemia and false aneurysm may result. Some small false aneurysms thrombose spontaneously; persistent narrow-necked aneurysms can be treated with compression, while larger-necked
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Vascular injuries in children The principles of management of paediatric vascular injuries are the same as for adults. The arteries in children tend to go into a severe spasm when injured and this should be considered when attempting repair. The effect of chronic ischaemia on the growth of the limb must be considered. ◆
Cross reference Garner J. Blunt and penetrating trauma to the abdomen. Surgery 2005; 23(6): 223–8.
332
© 2007 Elsevier Ltd. All rights reserved.
Vascular trauma Nigel Tai John P Raj Michael Walsh
Abstract This contribution discusses the basic concepts of vascular trauma.
Keywords blunt injury; penetrating injury; blast injury; intimal injury; arterial spasm; duplex ultrasonography; digital subtraction angiography
Mechanism of injury
a
Blunt injury can disrupt vessels directly (Figure 1) after a crush or indirectly after disruption to tissues injured at some distance from the point of impact. Fractures of long bones and joint dislocations may impinge bone ends onto the vessel. Penetrating injuries to vessels after knife wounds or low-energy bullet wounds may be partial or complete, depending on missile trajectory. High-energy transfer wounds cause massive local vascular disruption, directly or by transfer of energy from nearby bony injury. Blast injury (see Garner, CROSS REFERENCE) is the damage caused by the consequences of explosive detonation, and may involve blunt and penetrating mechanisms. Vessels may be damaged by the blast wave, by secondary fragments (shrapnel) or by the blast wind, causing bodily displacement.
b a Radiograph showing severe humeral disruption of the left arm (arrow) after impact with a tube train. b Angiogram showing an associated vascular injury (arrow).
Iatrogenic injuries: blood vessels may be damaged during surgery, radiological procedures or when obtaining access to the circulation. After injury, further damage may be caused during exploratory surgery.
Figure 1
Types of vascular injuries Vessel disruption is the commonest vascular injury and may be partial or complete. Partial disruptions usually cause active bleeding if an open wound is close to the disruption. It may present as an expanding or pulsatile haematoma (Figure 2). Partial disruptions may not present with ischaemia because a channel for blood flow can be maintained. False aneurysms may develop if a partial disruption is unrecognized. Complete disruptions usually present with haemorrhage, which decreases as the vessel goes into spasm and a clot develops (Figure 3).
This article was first published in Surgery 2004; 22(11): 288–93. Nigel Tai FRCS is a Specialist Registrar in Trauma and Vascular Surgery at Bart’s and the London NHS Trust, London, UK. Conflicts of interest: none declared. John P Raj MS(Gen) is a Consultant General Surgeon at Christian Medical College, Vellore, India. Conflicts of interest: none declared.
Intimal injuries are the second commonest type of vascular injury and may lead to thrombosis of the vessel or the formation of an intimal flap, progressing to distal ischaemia. Occasionally, an intimal flap may cause a dissection, which extends with time and may become apparent later.
Michael Walsh FRCS is a Consultant Vascular and Trauma Surgeon at Bart’s and the London NHS Trust, London, UK. Conflicts of interest: none declared.
SURGERY 25:8
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© 2007 Elsevier Ltd. All rights reserved.
Vascular
Arteriovenous fistula formation occurs if an artery and its adjacent vein are injured. They are commonly seen after penetrating trauma and tend to present late.
Classification of vascular injuries and their sequelae Incomplete transection
Arterial spasm is rare and should not be considered as the cause of limb ischaemia after trauma.
Pulsatile haematoma Rupture Delayed haemorrhage Thrombus Embolism False aneurysm Arteriovenous fistula
Diagnosis Clinical Diagnosis can be difficult and requires a high degree of suspicion and careful evaluation. The clinical features associated with vascular injury are divided into ‘hard’ signs and ‘soft’ signs (Table 1). Hard signs indicate vascular injury that requires attention; soft signs are suggestive of vascular injury and mandate further evaluation. Vascular injuries can also present with very little clinical evidence to suggest injury. The incidence of occult injuries to vessels close to a penetrating injury is about 20%.
Complete transection
Transection with spasm of the vessel Distal ischaemia Pulse deficit
Imaging Duplex ultrasonography is a non-invasive method that can detect arterial disruption, thrombosis, false aneurysms and arteriovenous fistulae. It is operator-dependent and has a diagnostic accuracy of >90%.
Closed injuries
Bone
Compression between bone fragments
Contrast-enhanced CT is a useful tool to evaluate injuries of the great vessels. It is becoming the first-line investigation for evaluating thoracic aortic injuries. CT should be reserved for the haemodynamically stable.
OR
Stretch
Digital subtraction angiography (Figure 4) is the first-line investigation for evaluating arterial injuries. Interventional radiological techniques may be used for treatment in certain circumstances (e.g. stenting of intimal flaps and partial disruptions). In actively bleeding injuries, on-table angiography can be done when bleeding is controlled.
Thrombosis Intimal tear and flap causing dissection, or occlusion Subintimal haematoma causing occlusion
Management Figure 2
Attention should first be paid to the airway and the breathing before the circulation is addressed (Figure 5). Haemorrhage control Direct pressure is the safest and most effective way of controlling external bleeding. Surgical exploration is urgently needed if bleeding is not controlled.
Clinical signs associated with a vascular injury
Figure 3 Angiogram showing transaction of the external carotid artery (arrow) due to a stab injury. Extravasation of contrast is absent because a clot has developed.
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‘Hard’ signs
‘Soft’ signs
Pulseless, cold, pale limb Expanding haematoma
History of active bleeding Penetrating injury in close proximity to a major vessel Non-expanding haematoma Neurological deficit
Palpable thrill or an audible bruit Active bleeding Table 1
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© 2007 Elsevier Ltd. All rights reserved.
Vascular
Management of vascular injuries Trauma Assessment with attention to airway and breathing first Haemodynamic instability or obvious external haemorrhage Yes
No
Immediate exploration Direct pressure over bleeding point for temporary control Consider arterial embolization for pelvic fractures
Present
Digital subtraction angiography followed by surgery On-table angiogram during surgery
Figure 4 Digital subtraction angiogram showing an arteriovenous fistula (arrow) between the right subclavian artery and vein after a gunshot wound to the chest.
Inflating the balloon of a Foley catheter in the track of a neck wound may tamponade bleeding. Penetrating injuries at the root of the neck often bleed into the thoracic cavity and two Foley catheters may be needed to obtain control. The first is inserted into the wound to reach the pleural cavity. The balloon is inflated and the catheter is pulled back to tamponade the injury from below. The second catheter is placed into the wound track and the balloon inflated to complete the control. Catastrophic intraabdominal bleeding may be controllable only by laparotomy or left thoracotomy with crossclamping of the thoracic aorta. Interventional radiology may be used to control bleeding by balloon tamponade (Figure 6) or embolization. Balloon cath eters (inserted via a remote vessel and deployed upstream of an injured vessel) can provide proximal control of haemorrhage in the Emergency Department before transfer to theatre for definitive surgery. Image intensification is not needed because the site of balloon deployment can be determined by monitoring the ar terial pressure waveform as the catheter is ‘floated’ into position. Coil embolization has a role in haemorrhage control of bleeding branches of the internal iliac artery after pelvic fractures and may be undertaken as part of the ‘circulation’ stage of the primary survey.
Not present
Soft signs (see Table 1)
Present
Not present
Duplex ultrasonography measure ABPI if not available
Vascular injury or ABPI <1
No injury shown, ABPI >1
Observe
ABPI: Ankle–brachial pressure index
Figure 5
Surgical repair of arterial and venous injuries Preparation of the vessel: fractures and dislocations should be reduced and fixed before undertaking vascular repair. The entire injured extremity and an uninjured lower limb should be prepared in case an autogenous vein graft is needed. Proximal and distal control of the blood vessels is obtained by exposing a generous length of the vessel either side of the injury and placing silastic slings or tapes around the vessel proximal and distal to the injury. If arterial clamps are used to obtain control, apply enough pressure to achieve occlusion to minimize the risk of
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Hard signs (see Table 1)
Figure 6 Angioplasty balloon sited in the subclavian artery before surgical exploration in a patient with disruption to the axillary artery. Contrast extravasation is due to collateral backflow distal to the balloon.
329
© 2007 Elsevier Ltd. All rights reserved.
Vascular
intimal damage. The aorta should be clamped because occlusion with a sling is inappropriate. Intra-arterial balloon occlusion catheters may be used to obtain control in difficult circumstances. The vessel is debrided and trimmed. Intimal flaps can be sutured down using longitudinal interrupted 6/0 sutures. A balloon embolectomy catheter is passed proximally and distally to clear intraluminal thrombi and to ensure that inflow and run-off are satisfactory. On-table angiography should be used to identify occult injuries and remaining thrombi. Once the vessel is clear, intra-arterial heparin (5000 units per 500 ml saline solution) is injected proximally and distally to prevent further thrombosis.
sufficient calibre to replace vessels up to the superficial femoral artery in size. If a vein is not available, prosthetic grafts made out of expanded polytetrafluoroethylene are used because they are resistant to infection.
Lateral suture is used for closing simple lacerations in mediumand large-sized vessels and transverse lacerations in smaller arteries (Figure 7a). Interrupted or continuous sutures are placed through the entire thickness of the vessel wall. A patch angioplasty is required if the vessel is likely to become narrowed using this technique.
Endovascular treatment of vascular trauma (particularly if vessel exposure is technically difficult or if there is significant comorbidity) is increasing in use. Covered stents may be inserted percutaneously or via open ar teriotomies, manoeuvred into position under radiographic guidance and used to restore integrity to punctured vessels such as the vertebral, subclavian, axillary, carotid and iliac arteries. Stent repair for the treatment of traumatic disruption of the thoracic aorta is preferential to open repair because cardiac bypass is avoided. Advantages include: • less invasive • procedure is quicker • less blood is lost • less anaesthesia is needed. The disadvantages of such techniques are well described. • Intravascular prostheses may be malpositioned, embolize, thrombose or suffer structural failure. • Endoleak can occur and there is potential for contamination and infection of stents in penetrating trauma. • Out-of-hours availability of a dedicated angiography suite plus attendant interventional radiologist is a prerequisite that few UK
Bypass procedures should be considered in complex vascular injuries (Figure 8) and after ligation of major arteries. Severely contaminated wounds or large loss of soft tissue may also require an extra-anatomical bypass to ensure graft cover, avoid graft infection and maintain the circulation. The conduit depends on the circumstances and the vessels involved.
Vein patch angioplasty (Figure 7b) is used for closing longitudinal lacerations in smaller vessels. A suitable piece of vein culled from nearby subcutaneous tissue can be used. An end-to-end anastomosis is required to restore continuity to transected vessels. The ends of the vessel should be cut obliquely (Figure 7c) to reduce the risk of stenosis. The vessel ends should be approximated without undue tension. The anastomosis is carried out using interrupted or continuous sutures. Stay stitches inserted at two or three equal intervals prevent pursestringing and subsequent stenosis if the continuous method is used. An interposition graft is used if vessel ends cannot be approximated without tension. A reversed long saphenous vein is of
Closing arterial lacerations
Vein patch
a Closure of an incomplete tear directly with a simple suture
b Closure of a large longitudinal tear with a vein patch
c Repair of a complete transection (see Figure 2) using a three-point stay suture with a continuous suture for the anastamosis
Figure 7
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© 2007 Elsevier Ltd. All rights reserved.
Vascular
be anticipated and fasciotomies done. Amputation should be the definitive procedure in the event of irreversible ischaemia of the limb after damage control.
Complications of vascular injuries The repair of vascular injuries depends on prompt diagnosis and management of other life-threatening injuries (Table 2). Delays in diagnosis may lead to the complications discussed below. False aneurysms A false aneurysm (Figure 9) develops if there has been a partial disruption to the vessel, which continues to bleed into a contained haematoma. False aneurysms are more common in pen etrating and iatrogenic injuries (see below). False aneurysms may be treated using ultrasound-guided pressure or by injection of thrombin into the lumen of the false aneurysm. Surgery should be done if this does not succeed.
Figure 8 Surgical repair of a degloved thigh and disrupted superficial femoral artery and vein after a crush injury caused by a lorry. The distal popliteal artery is controlled by a sling (black arrow). An expanded polytetrafluoroethylene graft (green arrow) was used for reconstruction.
Arteriovenous fistulae Arteriovenous fistulae are seen in penetrating injuries. They present late, with a pulsatile mass and a palpable thrill. Surgery involves disconnecting the fistula and produces good results.
hospitals can boast, and the time lost summoning personnel and equipment may expose the patient to additional hazard. • There is a large body of evidence describing the durability of a well-conducted surgical operation, but the endovascular series emanating from most trauma centres are small and with limited follow-up.
Compartment syndrome A compartment syndrome occurs if the pressure within the muscular compartments of the limbs rises to >30 mmHg. It is caused by a reperfusion injury after ischaemia. It is more common in patients who have: • had prolonged periods of hypotension • arterial occlusion • a combined arterial and venous injury • had a vein ligated • had a severe crush injury. The increased pressure is relieved by a fasciotomy which lays open the entire fascial envelope of the muscle compartment along with the overlying skin. If a fasciotomy is not done at the time of the surgery, compartment pressures should be measured and fasciotomies carried out if pressures are >30 mmHg.
Damage control Damage control should be considered in patients who have multiple injuries with gross physiological derangements. Damage control allows time for resuscitation, stabilization and investigation before definitive repair. The aims are to control bleeding and to maintain circulation by simple measures. Damage control may be achieved by shunting, ligation or packing. Shunting to restore blood flow to a limb is the preferred damage control manoeuvre and is also indicated if prolonged orthopaedic stabilization is required before vascular repair. If venous and arterial injuries coexist, both should be shunted. In addition to commercially available shunts, sterile infant feeding tubes, nasogastric tubes and chest drains can been used as temporary shunts. The major complications are dislodgement and occlusion of the shunt.
Amputation Amputation of the affected limb may be the first-line treatment in limbs where there are signs of irreversible ischaemia, extensive
Ligation: the external carotid, subclavian arteries in their second part, and the internal iliac arteries can be ligated with minimal sequelae. In an emergency, the common and internal carotid arteries can be ligated with a good chance of neurological recovery. Ligation of the major limb arteries is likely to lead to significant limb ischaemia requiring open fasciotomies. Ligation can be carried out on all limb veins and the inferior vena cava at the cost of limb oedema. The jugular veins can be ligated without major problems.
Poor prognostic factors that affect the outcome of vascular repairs Delays in treatment of >6 hours Blunt injuries An absent Doppler ultrasound signal in the vessel at admission Clinical presentation with ischaemia Other associated injuries that require immediate attention Injury to lower extremities (particularly injuries of the popliteal artery) Chronic ischaemia of the limb
Packing controls major arterial bleeds poorly, but may be used to control venous bleeds. It is particularly useful for vascular injuries of the pelvis and the retrohepatic inferior vena cava. A definitive procedure to restore blood supply should take place when the patient has stabilized. Reperfusion injury should
SURGERY 25:8
Table 2
331
© 2007 Elsevier Ltd. All rights reserved.
Vascular
varieties require fibrin glue or surgery. Limb ischaemia may result from an intimal flap or dissection after angioplasty. Vessel rupture is rare, but is seen occasionally after angioplasty of external iliac artery disease; the resultant extensive bleeding may threaten life. Temporary vascular control can be obtained with a proximal balloon while preparations are made for surgery or the insertion of a covered stent. The treatment plan must consider comorbidity (e.g. diabetes, heart and renal disease) and the poor physiological reserve of these patients. The surgical options are guided by the • disease state of native vessels • necessity to preserve collateral supply • possible lack of suitable vein for bypass • amount of in-flow and run-off. Surgery to correct such injuries is associated with a mortality of about 10%, emphasizing postoperative care in the ICU or HDU.
Venous injuries
Figure 9 False aneurysm of the suprarenal artery (arrow) after a stab injury.
The veins that are usually injured are the superficial femoral (42%), popliteal (23%) and common femoral (14%). Venous injuries should be treated using similar techniques to arterial injuries and repaired wherever possible unless the patient is haemodynamically unstable and the injuries are complex. In this situation, ligation of the vessel followed by elevation of the extremities is appropriate.
damage to soft tissue or extensive neurological damage. Amputations are more likely if there have been delays in recognizing vascular injury, in injuries involving the popliteal artery and crural vessels, and if there have been delays in resuscitation. Iatrogenic vascular trauma Blood vessels may be damaged by orthopaedic, abdominal or gynaecological misadventure, but iatrogenic trauma is usually due to percutaneous introduction of vascular catheters used to diagnose or treat cardiovascular disease. Damage may occur locally at the site of the vessel selected for access, at the site of intervention or anywhere in between. The common femoral artery is the most common site of trauma. Arteriovenous fis tulae, intimal disruption, vessel thrombosis, rupture, acute limb ischaemia and false aneurysm may result. Some small false aneurysms thrombose spontaneously; persistent narrow-necked aneurysms can be treated with compression, while larger-necked
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Vascular injuries in children The principles of management of paediatric vascular injuries are the same as for adults. The arteries in children tend to go into a severe spasm when injured and this should be considered when attempting repair. The effect of chronic ischaemia on the growth of the limb must be considered. ◆
Cross reference Garner J. Blunt and penetrating trauma to the abdomen. Surgery 2005; 23(6): 223–8.
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