APPROACH TO VASCULAR INJURY BY DR SIKHOSANA

Mechanisms of injury Penetrating Blast Blunt iatrogenic

Pathophysiology Missile damage is related to the velocity Shotgun causes multiple perforations and can cause embolization Blunt trauma results from shearing or distraction Vascular spasm occurs at or distal to the injury due to the unapposed sympathetic constriction, it is not the cause for ischaemia

Hard signs Pulsatile bleeding Expanding haematoma Thrill or bruit Pulse deficit ischaemia

Soft signs History of a significant bleed Small non expanding haematoma Associated nerve injury Proximity to a major vessel

Unclear presentation Thorax injuries- suspect if there is a widened mediastinum, persistent shock, large haemothorax Intimal injury- the pulses maybe intact but the exposed collagen is very thrombogenic

Indications for investigation: neck Zone I and III All gunshots Suspicion post doppler of zone II

Mediastinum Fracture of 1st,2nd ribs, sternum and scapula Sterno clavicular joint dislocation Trans axial gunshot Widened mediastinum Obliteration of aortic notch, left apical pleural cap, aorto-pulmonary window Left haemothorax Oesophageal and tracheal deviation to the right Depression of left main bronchus

Limbs Multiple fractures Multiple penetrating injuries Shotgun Knee/elbow dislocation Degloving injury Gunshot tract along the long axis of the vessel

Imaging modalities Duplex ultrasound Angiography CT angiography MRA

Duplex ultrasound Combines pulsed doppler and real time B mode ultrasound imaging Advantages- non invasive, cheap, no radiation and sensitive Locally used for neck zone II and single peripheral injuries

Angiography Gold standard imaging and there is a therapeutic option, although it is invasive Features suggestive of injury- extravasation of contrast, dilatation due to intimal injury, narrowing, occlusion, filling defects and AV fistula

CT angiography Sensitivity and specificity of 90-100% Advantage is that it is non invasive and rapid Disadvantages – lack of therapeutic options, artifacts from foreign bodies, streak artifacts simulating intimal tears and the imaging of the arch not good on CT

MRA Has good sensitivity Not ideal due to the time taken for the investigation

Bleeding control Pressure balloon

Management All vascular injuries should be repaired as ASAP to avoid delayed bleeding, compressive haematoma and limb compromise We do not believe in conservative management of minimal arterial injuries because the history is unpredictable, poor patient compliance and too late presentation of complications

Mangled extremity severity score Skeletal/soft tissue injury Limb ischaemia Shock Age Score of >7 is accurate for predicting eventual need for amputation

Diagnostic fasciotomy More than 6 hours presentation

Prophylatic fasciotomy Prolonged hypotension Extensive soft tissue injury Arterial and venous injury Bone plus vascular injury Delayed vascular repair Inability to assess the patient, e.g. head/spinal injury

Therapeutic fasciotomy Increased tissue turgor Extensive deep haematoma in the presence of ischaemia FASCIOTOMY BEFORE VASCULAR REPAIR

Principles of vascular repair Digital or sponge pressure and catheter to control bleeding Prophylatic antibiotics Access available to the groin for the graft Wide exposure with proximal and distal control Edges debrided to healthy intima Embolectomy and flushing with heparin saline Vascular repair before ortho Adequate tissue cover of the vascular repair

Techniques of repair Lateral – for wide calibre vessels Patch- to prevent stenosis End to end- single tethering stitch should hold and < 4mm vessel should have interrupted sutures Interposition graft- NB similar size with the injured vessel Ligation- gross contamination and unstable patient

Types of grafts Vein- no cost and low infection rate Arterial- same advantages as the vein but the donor site may need to be replaced Synthetic- ? Higher infection risk, expensive and poor patency across joints

Causes of graft thrombosis In flow Anastomosis – intimal injury, adventitia, tension, stenosis, poor graft Run off

Primary amputation Dead leg 2 or more dead compartments Mangled limb

Endovascular Embolisation Stenting Balloon occlusion

Conclusion All vascular injuries should be repaired as soon as they are identified We do not have enough man power to treat minimal injuries consevatively