peripheral vascular injuries

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  • 1.PERIPHERAL VASCULAR INJURIES Dr Latif Khan PGR-1 Surgical Unit-1 Services Hospital Lahore

2. INTRODUCTION Peripheral injuries account for 80% of all cases of vascular trauma. The lower extremities are involved in two thirds of all patients with vascular injuries. 90% of patients with vascular trauma are male Complex extremity trauma involving both arterial and skeletal injuries is rare, comprising only 0.2% of all military and civilian trauma, and only 0.5%- 1.7% of all extremity fractures and dislocations Combined arterial and skeletal extremity trauma imparts a substantially higher risk of limb loss and limb morbidity than do isolated skeletal and arterial injuries. 3. CHALLENGES OF VASCULAR INJURIES most dramatic challenges facing trauma surgeons because the repair is often urgent Gaining control of and reconstructing a major arterial injury can be technically demanding. Limited exposure to vascular surgery in the general surgery training curriculum, Major vascular trauma remains a crucial element of trauma surgery, and every general surgeon must be prepared to deal with them either definitively or using so-called bail-out vascular damage control tactics. The fundamental difference between elective vascular surgery and vascular trauma is the physiology of the wounded patient 4. CONTD.. A lacerated major vessel is typically only one component of the multi trauma complex that includes injuries to other organs and systems. These patients are often critically ill and rapidly approaching a point of physiologic irreversibility. In these dramatic clinical circumstances, the key to a favorable outcome is maintaining correct priorities. The surgeon must keep in mind that although major hemorrhage (typical of trunkal vascular injuries) is an immediate threat to the patient's life, ischemia (commonly from peripheral arterial injury) is a threat to limb viability, a much lower priority. Furthermore, although control of hemorrhage is usually mandatory and life-saving, the reconstruction of an injured vessel may be neither. As the injured patient is approaching the boundaries of his or her physiologic envelope, a simpler, sometimes temporary technical solution is often a safer option than a complex and time-consuming re construction. In the severely traumatized patient, the best technically feasible definitive solution is not always in the patient's best interest 5. AETIOLOGY Gunshot wounds, 70-80% of all vascular injuries requiring intervention. Stab wounds (5-10% of cases require intervention) Blunt trauma (5-10% of cases): Presence of fracture or dislocation increases the risk. Iatrogenic injury (5% of cases): Endovascular procedures central line placement 6. INITIAL ASSESMENT Airway Breathing/ventilation Circulation Disability Exposure 7. Immediate treatment Control bleeding Replace volume loss Cover wounds Reduce fractures/dislocations Splint Re-evaluate 8. HARD SIGNS Active or pulsatile hemorrhage Pulsatile or expanding hematoma Signs of limb ischemia and elevated compartment pressure including the 5 "P's: Pallor paresthesia pulse deficit paralysis pain Diminished or absent pulses Bruit or thrill is( present in 45% of patients with an arteriovenous fistula) 9. SOFT SIGNS Hypotension or shock Neurologic deficit due to primary nerve injury occurs immediately after injury. In contrast, ischemic neuropathy is delayed in onset (minutes to hours). Stable, non pulsatile or small hematoma Proximity of the wound to major vascular structures ( Beware of bone fr. ! ) 10. COMPLICATIONS Delayed diagnosis and treatment may result in Thrombosis Embolization Rupture with hemorrhage. Risk factors for amputation include Elevated compartment pressure Arterial transection Associated open fractures The combination of injuries above and below the knee. 11. CHRONIC PRESENTATION OF VASCULAR INJURY Arteriovenous fistulae typically take months to mature and often require surgical repair. Pseudoaneurysms may resolve completely or grow over time presenting months to years later. They may cause neuropathy due to compression or embolization , or they may present as a growing pulsatile mass. Intimal tears and flaps generally heal spontaneously. 12. CONTINUED Segmental narrowing can present with diminished flow but intact pulses. This injury may resolve spontaneously with fluids and rest, or it occasionally may require surgical intervention. N.B. Approximately 10% of patients with non occlusive, clinically occult injuries require repair within a month of initial injury. The remaining 90% of patients do not report symptoms or see a physician for vascular problems during long- term follow-up 13. Pathology 1. Spasm (or compression) 2. Intimal injury 3. Transection 4. Intramural haematoma 5. Pseudoaneurysm 14. Time Pathophysiology Ischaemia Rapid resuscitation Urgent exploration Ischaemia revascularisation Tissue necrosis Reperfusion injury Compartment syn ? fasciotomy 15. MANAGEMENT 16. Immediate referral Hard signs Immediate (vascular) surgery referral Early transfer to theatre Angiography Immediate exploration 17. Soft signs, other injuries Resusitate Apply compression Immobilise Reduce Reassess asymmetry Consult 18. INVESTIGATIONS 19. Pulse Oximetry: A reduction in oximeter readings from one limb, as compared to another is suggestive of, but neither confirms nor excludes a significant vascular injury 20. Doppler Ultrasound Evalution of the affected extremity with hand held doppler ultrasound should be performed routinely. Absent doppler signals need further examination- either with angiography or duplex scan. Every doppler examination whether normal or abnormal should be followed by Ankle Brachial Pressur Index(ABPI) An ABPI > 1 is normal Any measurement < 0.9 need further evalution with angiography 21. Duplex Ultrasound Duplex can detect intimal tears, thrombosis, false aneurysms and arteriovenous fistulae. Although it is limited by operator dependent It has senitivity of 95% and specificity of 99% with overall accuracy of 98% 22. Angiography Angiography remains the gold- standard investigation for the further investigation and delineation of vascular injury. In most traumatic injury settings, angiography is best performed in the operating room, with the surgeon exposing the vessel proximal to the injury for control and expediency Sensitivity 92-96% Specificity above 96% Accuracy 98% 23. CT ANGIOGRAM With the advent of improved CT scan, detection of vascular injuries has greatly improved In fact CTA is becoming a viable alternative to angiography Occasionally CTA be non-diagnostic due to significant artifact from bullet fragements or other foreign bodies Sensitivity 90-100% Specificity 98-100 % 24. MAGNETIC RESONANCE ANGIOGRAPHY MRA is used less frequently in acute settings Metal implants such as cerebral aneurysm clips and cardiac pacemakers preclude the use of MRI or it is difficult to acertain whether the patient have such devices in emergency situation Additionally MRI takes longer and needs more co- operation from patient than CT. 25. TREATMENT 26. IMMEDIATE TREATMENT Control of haemorrhag: Direct pressure over the site of injury One individual manually compress the site of haemorrhage. Deep knife or gunshot track catheter If angiography is performed prior to surgery, it may be possible to obtain proximal control by passing an angioplasty balloon catheter into the proximal vessel and inflating the balloon 27. VOLUME RESUSCITATION Prior to haemorrhage control : Minimal fluids should be administered Raising the blood pressure will increase haemorrhage from the vessel injury and dislodge any clot that has already formed. Systolic blood pressure can be maintained at a level that is appropriate for perfusion of the brain After: aggressive volume resuscitation to restore circulating blood volume. Warm fluids -crystalloid, blood or clotting factors as necessary -are administered to correct acidosis, hypothermia and coagulopathy, 28. OPERATIVE TREATMENT 29. OPERATIVE PRINCIPLES The patient is positioned on the operating table to allow on-table angiography of the affected region and distal perfusion. The entire affected limb is prepped and draped, as well as proximal structures if control has to be gained more proximally. The hand or foot is prepped so that intra-operative assessment of distal perfusion is possible. An entire uninjured limb should also be prepped so that a vein graft can be harvested as required. Often the person applying manual compression at a bleeding site will have to be temporarily prepped into the operative field until scrubbed personnel can take over. Gain proximal and distal control of injured vessel before investigating the site of injury. It is achieved by a separate incision away from site of injury. Direct exploration of site of injury lead to failure of haemostasis and damage to adjacent tissue. Control is best achieved by passing slings twice around the vessels. If clamps are used they should be applied with minimum force to obstruct the flow of blood not racked closed to damage the vessel. 30. CONTD Once the injured vessel is identified, then debride devitalised tissue. Asses the inflow and outflow at both end of vessel, if inadequate pass forgatry at proximal and distal end to disloge any thrombus. Instill heparinized saline at proximal and distal ends to locally anticoagulate the vessel. Use an arterial shunt if temporizing is required or delay is anticipated, e.g. to stabilize fracture. Obtain an on-table angiogram if suspecting further injury or chronic disease. If necessary select a more distal site for anastomosis of bypass graft. Harvest vein for a conduit. Avoid synthetic material in a potentially contaminated operative field. Perform appropriate bypass using inlay, end-to-end, or end-to-side anastamoses. Consider fasciotomies. Co-o