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Thoracic Great Vessel Injuries PowerPoint Presentation

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Description : Check out this medical presentation on Aorta, which is titled "Thoracic Great Vessel Injuries", to know about the injuries to the thoracic great vessels including Aorta & Branches (Brachiocephalic Artery, Subclavian Artery, and Carotid Artery), Pulmonary Arteries/Veins, SVC/IVC, Innominate Veins, and Azygos Veins.

Tags : Aorta, Thoracic Great Vessel Injuries, Aorta and Branches, Brachiocephalic Artery, Subclavian Artery, Carotid Artery, Pulmonary Arteries, Veins, SVC, IVC, Innominate Veins, Azygos Veins

Published on : Jun 02, 2021 | Views : 2748 | Downloads : 3

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Slide 1-

Thoracic Great Vessel Injuries Niqui Kiffin, M.D. Operative Skills Lecture
Slide 2-

Introduction Injuries to the thoracic great vessels Aorta & Branches Brachiocephalic Artery Subclavian Artery Carotid Artery Pulmonary Arteries/Veins SVC/IVC Innominate Veins Azygos Veins Injuries may be acute or chronic… Acute Death by exanguination Chronic Fistula formation Post-traumatic pseudoaneurysm Be aware of anatomic anomalies when assessing these patients
Slide 3-

Anatomy
Slide 4-

Etiology/Pathophysiology Penetrating trauma > 90% of thoracic great vessel injuries GSW SW Shrapnel Iatrogenic CVC placement CT placement IABP ER Thoracotomy Swan-Ganz balloon overinflation Self-expanding metal stents (esophageal/tracheal) Low-riding tracheostomy tubes
Slide 5-

Etiology/Pathophysiology Blunt Trauma Particularly susceptible… Innominate Artery Pulmonary Veins Vena Cava Thoracic Aorta Cause 10-15% of deaths following MVC Prox descending – 54-65% Ascending/Transverse arch – 10-14% Mid- or distal descending – 12% Multiple sites – 13-18%
Slide 6-

Etiology/Pathophysiology Blunt Trauma Mechanisms… Shear forces Relative immobility of a portion of the vessel adjacent to a fixed portion Atrial attachments – Pulmonary Veins, Vena Cava Descending thoracic aorta - Ligamentum arteriosum/diaphragm Compression Between two bony structures Innominate Artery – May be pinced between sternum and vertebrae Profound intraluminal HTN
Slide 7-

Etiology/Pathophysiology Blunt Trauma (Aortic) Most commonly full-thickness Traumatic dissection is very rare Equivalent to a ruptured aortic aneurysm that is contained by surrounding tissues (intact parietal pleura) Maintain permissive hypovolemia and control tachycardia
Slide 8-

Classification Exanguinating Hemorrhage Die within 0-2 hrs of injury Mortality – nearly 100% Extensive multisystem injury With hemorrhage often being from sites other than the thoracic aorta Die within 2-4 hrs of injury Mortality ~ 96% CNS Injury Usually hemodynamically stable, but die anyway Mortality - 5-30%
Slide 9-

Prehospital Management Judicious IVF administration Excessive fluid resuscitation with the goal of increasing BP to normal or supernormal levels may actually increase mortality, ARDS, and other postop complications Increased BP may actually “blow out” a soft perivascular clot Endotracheal Intubation (+/-) Rapid Transport
Slide 10-

H & P History Length of knife, firearm type, number of rounds fired, and the patient’s distance to the firearm Amount of hemorrhage at the scene, intermittent paralysis, or hemodynamic instability Head-on and side-impact MVC Commonly cause aortic injuries Aortic injuries also reported with… Equestrian accidents Blast injuries Auto-pedestrian accidents Crush Injuries Falls from height > 30 ft
Slide 11-

H & P Physical ATLS Protocol Clinical findings… Pericardial tamponade +/- Hypotension Upper extremity HTN Unequal BP or pulses in the extremities External evidence of major chest trauma Expanding hematoma at the thoracic outlet Intrascapular murmur Palpable fracture of the sternum Palpable fracture of the thoracic spine Left flail chest 50% of pts with aortic/great vessel injury present without physical signs of injury FAST U/S Pericardial blood +/- tamponade
Slide 12-

Work-Up AP CXR (Penetrating) Place radiopaque markers over penetrating wounds Findings: Large hemothorax Foreign bodies FB “out of focus” Suggests intracardiac location Trajectory with a confusing course May indicate a migrating intravascular bullet “Missing” missile with a GSW to chest Suggests distal embolization in the arterial tree
Slide 13-

Work-Up AP CXR (Blunt) 7% of pts – normal appearing mediastinum on admission CXR Loss of aortic knob contour “funny looking” mediastinum Mediastinal widening > 8 cm Tracheal deviation Depression of the left mainstem bronchus Apical pleural hematoma Massive L hemothorax Fractures Sternal fracture Scapula fracture Multiple left-sided rib fractures 1st rib fractures
Slide 14-

Initial Management ED Thoracotomy In extremis 4th ICS left anterolateral thoracotomy Open pericardium Cross-clamp aorta Temporize bleeding Open cardiac massage Transport to the OR once vital signs re-established
Slide 15-

Initial Management Tube Thoracostomy Hemo- or PTX Attach tube to a repository for autotransfusion if significant output is noted. Urgent Thoracotomy > 1500cc initial output > 200- 250cc/hr
Slide 16-

Initial Management Avoid CVC in the upper extremities if concerned about a great vessel injury Blood transfusion Allow for moderate hypotension Increased BP may “blow-out” a soft protective perivascular clot Limit fluid administration until operative control of bleeding is obtained Avoid HTN Decreased incidences of ARDS and worsening of pulmonary contusions
Slide 17-

Initial Management Beta-Blockade Decrease dP/dT To minimize shear stress on the aortic wall May be used in hemo-dynamically stable patients who require a delay for definitive treatment Reduces the risk of fatal rupture Retrospective data only… No prospective data has demonstrated the safety or efficacy of such treatment
Slide 18-

Initial Management Spiral CTA of the Chest Mediastinal hematoma Intimal flap Active extravasation
Slide 19-

Initial Management Angiography Essential for localizing the injury and planning the appropriate incision or placement of the graft if performing endovascular repair “Negative” result May convey false security Laceration may have temporarily have sealed off Column of aortic contrast may overly a small area of extravasation Obtain multiple tangential views Consider in pts… Mechanism of injury PE CXR CT Chest Also be aware that patients can have aortic ruptures even after seemingly innocuous mechanisms Low-speed MVC With airbag deployment Intrascapular back blows to dislodge esophageal FB
Slide 20-

Treatment Options Nonoperative Management Consider in pts unlikely to benefit from immediate repair Severe head injury Risk factors for infection Major burns Sepsis Heavily contaminated wounds Severe multisystem trauma Attempt to achieve physiologic optimization and improve the outcome of repair Avoid HTN Beta-Blockers Has been used successfully in cases of “nonthreatening” aortic lesions (may heal spontaneously) Small intimal flaps ( aorta/brachiocephalic) Small pseudoaneurysms Long-term natural history is uncertain, therefore close follow-up is recommended
Slide 21-

Endovascular Stenting Began in the 1990’s Case reports and small series reported endografting of proximal descending thoracic aorta transections Initially, surgeons were using custom devices with aortic/iliac extenders Currently, device sizes range from 26-40mm Avg diameter among patients with aortic injury 19mm Manufacturers allow for 17% oversizing When oversized > 17%, the graft is at risk for compression and enfolding > 85% of injuries are < 1cm from the takeoff of the left subclavian artery A seating distance on either side of the injury of 2cm is needed, therefore L subclavian artery occlusion is a risk with endovascular repair
Slide 22-

Endograft vs. Open Techniques
Slide 23-

Surgical Repair Indications for immediate operative intervention Hemodynamic instability Significant hemorrhage from CTs Radiographic evidence of rapidly expanding mediastinal hematoma Be aware… Potential for neurologic complications Paraplegia Stroke Brachial plexus injuries Document a careful neuro exam Prophylactic Abx Limit fluid administration Autotransfusion Avoid wide swings in BP during induction
Slide 24-

Surgical Repair Operative Approach Depends on overall patient assessment and specific injury Adequate exposure is critical in order to obtain proximal/distal control Prep from neck to knees In stable patients, CTA or formal angiography may help dictate the operative approach Have appropriate graft material available Prosthetic graft is preferred for vessel diameter > 5mm Failure mode of infected graft = pseudoaneurysm Infected saphenous vein = may cause graft dissolution with acute rupture and uncontrolled hemorrhage
Slide 25-

Recommended Incisions Uncertain Injury (Unstable) L anterolateral thoracotomy +/- transverse sternotomy +/- right anterolateral thoracotomy (clamshell) Ascending Aorta Median Sternotomy Transverse Aortic Arch Median Sternotomy +/- neck extension Descending Thoracic Aorta L posterolateral thoracotomy (4th ICS) Innominate Artery Median Sternotomy with R cervical extension
Slide 26-

“Clam Shell” Exposure
Slide 27-

Clam Shell Exposure
Slide 28-

Median Sternotomy Incision
Slide 29-

Extending Sternotomy into Neck
Slide 30-

Recommended Incisions Right Subclavian Artery/Vein Median Sternotomy with Right Cervical Extension Left Common Carotid Artery Median Sternotomy with Left Cervical Extension Left Subclavian Artery/Vein L anterolateral thoracotomy 3rd or 4th ICS with separate L supraclavicular incision +/- connecting median sternotomy (Trapdoor) Pulmonary Artery Main/Intrapericardial Median Sternotomy Right or Left Hilar Ipsilateral posterolateral thoracotomy
Slide 31-

Recommended Incisions Pulmonary Vein Ipsilateral posterolateral thoracotomy Innominate Vein Median Sternotomy Intrathoracic Vena Cava Median Sternotomy
Slide 32-

Damage Control Consider for patients with severely compromised physiologic reserve… 1. Definitive repair 2. Abbreviated thoracotomy Control hemorrhage Plan for reoperation Examples: Pneumonectomy Temporary vessel ligation Placement of intravascular shunts Enmass closure of thoracotomy Wound VAC “Bogota Bag” Sterile plastic bag used for abdominal wall closure
Slide 33-

Arterial Injuries
Slide 34-

Distribution of Arterial Injuries with Penetrating Mediastinal Trauma Innominate 38% Aortic Arch 28% L CCA 18% L Subclavian Artery 8% Ascending Aorta 7% K. Buchan and J.V. Robbs, Surgical management of penetrating mediastinal arterial trauma, European Journal of Cardio-Thoracic Surgery Volume 9, Issue 2, 1995, Pages 90-94. Dept Surgery University of Natal, South Africa
Slide 35-

Ascending Aorta Rarely survive transportation… Total cardiopulmonary bypass Usually required for posterior injuries Dacron graft Survival approaches 50% for patients with stable vital signs on arrival to the Trauma center Always consider the possibility of a peripheral bullet embolus
Slide 36-

Transverse Aortic Arch Median sternotomy with extension into the neck Provides complete exposure of the arch and the brachiocephalic branches Exposure can be further enhanced by division of the innominate vein Use of balloon tamponade my limit hemorrhage Lateral arteriorrhaphy –simple repair CP Bypass – posterior lacerations, concomitant pulmonary artery injuries Survival also approaches 50%.
Slide 37-

Innominate Artery Median Sternotomy +/- Cervical Extension Blunt – Proximal injuries Actually represent aortic injuries requiring proximal control at the transverse aortic arch Penetrating – Injuries anywhere Divide Innominate vein if necessary
Slide 38-

Innominate Artery Partial Tears Running lateral arteriorrhaphy 4-0 Prolene suture Complex Tears Bypass Exclusion Technique Ascending Aorta to the distal innominate artery Dacron graft Avoid the area of injury until the areas for bypass insertion are exposed No need for hypothermia, systemic heparinization or shunts… Place a pericardial flap between the graft and the vein ( if vein left intact)
Slide 39-

Innominate Artery
Slide 40-

Descending Thoracic Aorta Prehospital mortality 85% - blunt injury If pts arrive alive, most injuries are located at the aortic isthmus At the ligamentum arteriosum Just distal to the take-off of the left subclavian artery
Slide 41-

Descending Thoracic Aorta Treatment Options Clamp/Direct reconstruction with/without an interposition graft Medical control of proximal HTN Passive bypass shunts Pump-assisted bypass Traditional CP bypass (req. heparinization) Atrio-femoral bypass using centrifugal pump (Heparin not necessary) Nonoperative and/or purposeful delay of operation Medical control of HTN Close radiological monitoring Endovascular Stenting
Slide 42-

Descending Thoracic Aorta Surgical Repair Posterolateral Thoracotomy – 4th ICS Proximal Control Obtain control of the aortic arch between the L carotid and L subclavian artery Avoid injury to L recurrent laryngeal nerve CP should be available Apply vascular clamps Proximal aorta Distal aorta L subclavian artery Close communication between surgeon and anesthesiologist Clamping Vasodilators – Prevents cardiac strain during clamping Unclamping Large volumes of fluid administration – Avoid clamp release hypotension
Slide 43-

Descending Thoracic Aorta Surgical Repair Enter hematoma Control intercostal artery bleeding Avoid indiscrimnate ligation of intercostal vessels Prox/distal ends of aorta are transected Esophagus!! Repair End to End Interposition graft
Slide 44-

Descending Thoracic Aorta Mortality rates 0-55% Avg 13% Primarily associated with multisystem trauma Due to head injury, infection, respiratory insufficiency, and renal insufficiency
Slide 45-

Descending Thoracic Aorta Paraplegia Most feared complication Passive shunts and CP bypass – considerable debate “Clamp-and-Repair” Virtually the same incidence of paraplegia as traditional repairs with bypasses and shunts
Slide 46-

Paraplegia Determinants are multifactorial… Perioperative hypotension Injury/ligation of intercostal arteries Duration of clamp occlusion Length of cross-clamp time does not directly correlate with the occurance of paraplegia < 30 minutes has been argued to provide a safe margin against paraplegia Recommend shunting techniques if > 30 minutes, however shunt provides no protection for the region of spinal cord that is supplied by the clamped arteries Also, recognize that pts requiring > 30 min of clamp time have more extensive injury…therefore it is likely that the increased paraplegia in this subset of patients is actually secondary to more extensive disruption of intercostal arteries and other flow to the anterior spinal artery caused by the original injury
Slide 47-

Subclavian Artery Intrathoracic Thoracic Outlet Cervical (Zone I) Upper Extremity
Slide 48-

Subclavian Artery R Subclavian Artery Median Sternotomy +/- cervical extension L Subclavian Artery Proximal Control Anterolateral Thoracotomy (2nd/3rd ICS) Distal Control Supraclavicular Incision Can be combined with infraclavicular incision to avoid removal of clavicle May be connected with a sternotomy (“Trapdoor”) Deltopectoral groove incision May also consider removal of clavicle
Slide 49-

Subclavian Artery Avoid injuries to phrenic nerve High associated rate of brachial plexus injuries Repair Lateral Arteriorrhaphy Interposition Graft Rarely end-to-end anastomosis
Slide 50-

Left Carotid Artery Mirrors the approach for an innominate artery injury Median sternotomy +/- L cervical extension Transection at the origin Bypass graft repair Preferred over end-to-end anastomosis
Slide 51-

Pulmonary Artery Intrapericardial Median Sternotomy Minimal dissection – Main/Prox L Dissect between the SVC and ascending aorta Anterior injuries – primary repair Posterior injuries – CP bypass Mortality rates approach 70%
Slide 52-

Pulmonary Artery Distal Present with massive hemothorax Repair via an ipsilateral posterolateral thoracotomy Rapid Pneumonectomy May be necessary in a life-threatening situation Tamponade with balloon… Exanguinating hemorrhage
Slide 53-

Internal Mammary Artery May produce massive hemothorax or pericardial tamponade Usually discovered by accident when thoracotomy performed for suspected great vessel or cardiac injury May be ligated for control
Slide 54-

Intercostal Arteries May cause massive hemothorax Ligation is necessary for control May require large sutures taken circumferentially around the rib proximally and distally
Slide 55-

Venous Injuries
Slide 56-

Thoracic Vena Cava Isolated injury to suprahepatic IVC or SVC is rare… Mortality > 60% Intrathoracic IVC Hemopericardium +/- tamponade Exposure is extremely difficult Usually requires total CP bypass with the inferior cannula in the groin Enhanced repair by opening the right atrium and placing a balloon in the cava to prevent air embolus and massive blood return t the heart Repair is done from the inside of the cava via the R atrium SVC Lateral venorrhaphy May require an intracaval shunt May use… PTFE or Dacron interpostion graft May also use saphenous vein panel grafts Usually too time-consuming Risk for blow-out
Slide 57-

Pulmonary Veins Difficult to manage via an anterior incision Usually requires an ipsilateral thoracotomy Consider temporary occlusion of the hilum If ligation is necessary… Resect the lobe as well
Slide 58-

Subclavian Veins Operative approach similar to arterial repair Repair: Lateral venorrhaphy Ligation
Slide 59-

Azygos Vein Not usually considered a thoracic great vessel However…large size and high flow cause injuries to be life-threatening Best managed by suture ligation of both sides of the injury
Slide 60-

Special Problems...
Slide 61-

Systemic Air Embolism Caused by a penetrating wound that injures a pulmonary vein and bronchiole and forms a fistula Allows air bubbles to enter the L heart and embolize to the systemic circulation Coronary Arteries – MI, cardiac arrest Cerebral Arteries – Seizures, CVA, death Treatment Thoracotomy Clamping of the pulmonary hilum to prevent further embolization Aspiration of the air from the left ventricle Trendelenburg position with right side down
Slide 62-

Foreign Body Embolism Thoracic great vessels may serve as both an entry site or final resting place for intravascular bullet emboli May produce infection, ischemia, or injury to organs distant from the site of trauma 25% lodge in the pulmonary arteries Should be removed to prevent pulmonary thrombosis, sepsis or other complications May be done via fluoroscopic guidance or open technique
Slide 63-

Post-Op Management
Slide 64-

Post-Op Management Careful hemodynamic monitoring Avoid HTN and hypotension IVF, pressors, and vasodilators Pulmonary Complications Atelectasis PEEP Respiratory Insufficiency Pneumonia ARDS Close monitoring of fluid administration
Slide 65-

Post-Op Management Hemorrhage Technical problem Urgent re-operation Coagulopathy Monitor/Correct with administration of FFP, cryo, etc…
Slide 66-

Post-Op Management Graft Infection Avoid bacteremia Strict sterile placement of CVC Post-op abx as needed Prophylactic Abx Prior to invasive procedures Dental, etc Long Term Complications Stenosis Thrombosis AV Fistula Graft Infection Pseudoaneurysm formation
Slide 67-

Conclusion Many patients with great vessel injury die in the field. Many die from exanguination, while others have an assortment of associated injuries Those pts that arrive in the trauma center should be treated rapidly Follow ATLS protocol Rapid assessment of injuries Quick transport to CT/Angio/OR Be aware of anatomical variations Have a multitude of incisions in your armamentarium Be aware of when/where to use damage control operations