• External landmarks: The axillary vessels start at the middle of the clavicle, course deep under the deltopectoral groove, and end at the lateral border of the axilla.

• The axillary artery is divided by the pectoralis minor into three parts: the first part is proximal to the muscle and gives one branch. The second part is under the muscle, is surrounded by the cords of the brachial plexus, and gives two branches. The third part lies lateral to the muscle, is surrounded by the nerves of the brachial plexus, and gives three branches.

• The axillary vein is the continuation of the basilic vein. Prior to its transition to the subclavian vein, the cephalic vein joins it. Its middle segment lies under the pectoralis minor muscle, inferior to the axillary artery.

• The indications for shunting after vascular injury include damage control for patients in extremis, the presence of associated fractures requiring fixation, the need for transportation to specialized centers for definitive reconstruction, or injury occurrence in an austere environment with limited resources.

• There are a number of commercially available vascular shunts. Improvised shunts can be constructed out of any plastic tubing that has the adequate diameter to match the corresponding vessel, such as chest tubes, intravenous tubing, and feeding tubes. Improvised shunts must be rigid enough that when they are tied into position, the sutures do not collapse the lumen of the shunt.

• When selecting the shunt size for temporary bypass, the largest size of shunt that fits into the injured vessel without forcing it into place should be selected. This will maximize distal blood flow.

• Commercially made shunts should not be trimmed. The edges of commercially made shunts are smooth and designed to avoid trauma to the intima of the artery.

• Improvised shunts should be left long, with redundant length in both the proximal and distal vessel. This will reduce the risk of inadvertent shunt dislodgement.

• The maximum length of time that a vascular shunt can remain in situ is unknown. It is important to perform definitive repair as soon as the patient’s physiology and other circumstances allow. Most shunts remain patent for 24–48 hours. The patency of the shunt is confirmed by the presence of a distal palpable pulse or dopplerable signal.

• For trauma purposes the neck is divided into three distinct anatomical zones.

  • Zone 1: from the sternal notch to the cricoid cartilage.

  • Zone 2: from the cricoid cartilage to the angle of the mandible.

  • Zone 3: from the angle of the mandible to the base of the skull.

• Knowing the contents of each zone is important when considering possible injuries.

  • Zone 1: the major vessels of the upper mediastinum, the lung apices, esophagus, trachea, thoracic duct, and thyroid gland.

  • Zone 2: the carotid sheath and contents, vertebral arteries, esophagus, trachea, pharynx, and the recurrent laryngeal nerve.

  • Zone 3: distal carotid and vertebral arteries, distal jugular veins.

• At the level of the superior border of the thyroid cartilage the common carotid artery bifurcates into the internal and external carotid arteries.

• At the level of the angle of the mandible, the internal and external carotid arteries are crossed superficially by the hypoglossal nerve and the posterior belly of the digastric muscle.

• The external landmark of the pharyngoesophageal and laryngotracheal junctions is the cricoid cartilage. On esophagoscopy, this is located 15 cm from the upper incisor teeth.

• The cricothyroid membrane is four fingerbreadths above the sternal notch.

• The cervical esophagus extends from the cricopharyngeus muscle into the chest to become the thoracic esophagus.

• The external landmark of the pharyngoesophageal junction is the cricoid cartilage. On esophagoscopy, this is at 15 cm from the upper incisors.

• The esophagus lacks a serosal layer and consists of an outer longitudinal and inner circular muscle layer.

• The cervical esophagus is approximately 5–7 cm long and lies posterior to the cricoid cartilage and trachea and anterior to the longus colli muscles and vertebral bodies. It is flanked by the thyroid gland and carotid sheath on either side.

• Blood supply is primarily from the inferior thyroid artery, although significant collateral circulation exists.

• The recurrent laryngeal nerves lie on either side of the esophagus in the tracheoesophageal groove.

• The lower leg venous system consists of the superficial (greater saphenous vein) and deep (femoral vein) systems. Duplicated saphenous systems exist in the calf and thigh in approximately 25% of patients.

• Distally, the greater saphenous vein can be found anterior to the medial malleolus. It crosses the tibia, runs medial to the knee, and ascends into the medial and posterior segment of the thigh as it descends medially into the common femoral vein in the groin (saphenofemoral junction).

• In the thigh, the greater saphenous vein lies deep to the fascia (unlike accessory veins or tributaries). This may help discriminate the veins of the thigh during dissection.

• In the proximal aspect of the thigh, the greater saphenous vein runs into the confluence of the superficial circumflex iliac vein, superficial inferior epigastric vein, and external pudendal veins to create the saphenofemoral junction. A useful anatomic landmark for the saphenofemoral junction is two fingerbreadths inferior and medial to the pubic tubercle.

• The anterior abdominal wall has four muscles: The external oblique, the internal oblique, the transversalis, and the rectus muscles. The aponeuroses of the first three muscles form the rectus sheath, which encloses the rectus abdominis muscle.

• The linea alba is a midline aponeurosis that runs from the xiphoid process to the pubic symphysis and separates the left and right rectus abdominis muscles. It is widest just above the umbilicus, facilitating entry into the peritoneal cavity.

• For vascular trauma purposes, the retroperitoneum is conventionally divided into four anatomic areas:

  • Zone 1: Extends from the aortic hiatus to the sacral promontory. This zone is subdivided into the supramesocolic and inframesocolic areas. The supramesocolic area contains the suprarenal aorta and its major branches (celiac axis, superior mesenteric artery (SMA), and renal arteries), the upper inferior vena cava (IVC) with its major branches, and the superior mesenteric vein (SMV). The inframesocolic area contains the infrarenal aorta and IVC.

  • Zone 2: Includes the kidneys, paracolic gutters, renal vessels, and ureters.

  • Zone 3: Includes the pelvic retroperitoneum, containing the iliac vessels and ureters.

  • Zone 4: Includes the perihepatic area, with the hepatic artery, the portal vein, the retrohepatic IVC, and hepatic veins.

The following are the major muscles that will be encountered and may be divided during thoracic operations for trauma.

• Anterior Chest Wall: Pectoralis major and pectoralis minor muscles

  • Pectoralis major muscle: It originates from the anterior surface of the medial half of the clavicle, the anterior surface of the sternum, and the cartilages of all the true ribs (1–7 ribs). The 5-cm wide tendon inserts into the upper humerus.

  • Pectoralis minor muscle: It arises from the third, fourth, and fifth ribs, near their cartilages, and from the aponeuroses over the intercostal muscles. It inserts into the coracoid process of the scapula.

• Lateral Chest Wall: Serratus anterior muscle

  • Serratus anterior muscle: It originates from the lateral part of the first eight to nine ribs and inserts into the medial aspect of the scapula.

• Posterior Chest Wall: Latissimus Dorsi

  • Latissimus Dorsi muscle: It originates from the spinal processes of the lower thoracic spine and the posterior iliac crest and inserts into the upper portion of the humerus.

• Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is a compliant, endovascular balloon designed to occlude the thoracic or lower abdominal aorta in hemorrhagic shock, for temporary control of bleeding in the abdomen or pelvis.

• The REBOA catheter is placed through a sheath in the right or left common femoral artery, accessed using anatomic landmarks, ultrasound guidance, or with open surgical technique. The balloon is then inflated in the thoracic or abdominal aorta, effectively acting as a minimally invasive aortic cross-clamp.

• The procedure for placing a REBOA takes only a few minutes.

• REBOA is ideally suited for hypotensive patients with abdominal or pelvic bleeding and can be placed in the emergency room, intensive care unit, or the operating theater.

• REBOA balloon placement can be guided and confirmed using external landmarks, X-ray, fluoroscopy, or ultrasound. Balloon inflation volumes are titrated based on invasive blood pressure monitoring, haptic feedback, and imaging.

• REBOA is contraindicated in patients with intrathoracic, neck, or facial bleeding, in cases with high suspicion for blunt thoracic aortic injury, and in patients in cardiac arrest.

• Aortic occlusion is a temporary, resuscitative measure and should be considered a transition to definitive care. After inflation, the patient should be immediately transported to the operating room or the interventional suite for definitive management of their traumatic injuries.

• REBOA balloon inflation results in distal ischemia and as such, occlusion times should be minimized.

• The vertebral artery (VA) is the first cephalad branch of the subclavian artery. From a trauma surgery perspective, the VA is divided into three parts. Part I runs from its origin at the subclavian artery to C6, where it enters the transverse foramen. Part II courses in the bony vertebral canal, formed by the transverse foramen of C6 to C1. Part III runs outside the vertebral canal, from C1 to the base of the skull. The VA enters the skull through the foramen magnum, piercing the dura mater. It joins the contralateral VA to form the basilar artery, which is part of the circle of Willis.

• The first part of the VA can be landmarked externally by the triangle formed by the sternal and clavicular heads of the sternocleidomastoid (SCM) muscle and the clavicle. It runs upward and backward between the anterior scalene and longus colli muscles, before entering the vertebral canal at the C6 level.

• The carotid sheath is anterior and medial to the first part of the VA.

• The external landmark of C6, where the VA enters into the vertebral canal and the second part of the VA begins, is the cricoid cartilage.

• The VA is surrounded by a venous plexus.

• The treatment goals of damage control surgery in orthopedics (DCO) include:

  • Give priority to other more severe, life-threatening associated injuries.

  • Improving vascular flow and subsequent tissue perfusion by reducing and realigning long bone fractures.

  • Temporary stabilization of long bone fractures, definitive fixation semi-electively, when the general condition of the patient improves.

• The esophagus is approximately 25 cm in length and begins at the level of the C6 vertebra. The external landmark is the cricoid cartilage. It terminates 2–3 cm below the diaphragmatic hiatus, which corresponds to the T11 vertebra.

• The esophagus is divided into three parts: cervical, thoracic, and intra-abdominal. The cervical esophagus begins approximately 15 cm from the upper incisors and is approximately 6 cm long. The thoracic esophagus begins approximately 23 cm from the incisors and is approximately 15 cm in length. The intra-abdominal esophagus begins approximately 38 cm from the incisors at the diaphragmatic hiatus and extends for 2–3 cm distally before becoming the gastric cardia.

• The thoracic esophagus rests on the thoracic spine and the longus colli muscles. It passes posterior to the trachea, the tracheal bifurcation, the left main stem bronchus, and the left atrium. It descends to the right of the thoracic aorta and moves anterior to the aorta, just above the diaphragm (Figures 18.1a and 18.1b).

• The azygos vein lies in front of the bodies of the lower thoracic vertebrae and to the right of the esophagus. At the level of the bifurcation of the trachea, it arches anteriorly to drain into the superior vena cava, just before it enters the pericardium.

• The hemiazygos vein passes from the left side of the spine to the right, after crossing the spine and travelling behind the aorta, esophagus, and thoracic duct, to drain into the azygos vein.

• The thoracic duct lies between the esophagus, the aorta, and the azygos vein before crossing over, just below the level of the tracheal bifurcation, to the left hemithorax, where it drains into the left subclavian vein.

• The esophagus does not have a serosal layer. This increases the risk of anastomotic leaks.

• The arterial and venous blood supply and drainage of the esophagus are segmental. The cervical esophagus is supplied by branches of the inferior thyroid artery. The upper thoracic esophagus is supplied by the inferior thyroid artery and an anterior esophagotracheal branch directly from the aorta. The middle and lower esophagus receives its arterial supply directly from the aorta via a bronchoesophageal branch. The lower esophagus and intra-abdominal esophagus portions are supplied by small branches from the left gastric artery and the left inferior phrenic artery.

• The parasympathetic innervation of the esophagus is through the vagal nerves. The right and left recurrent laryngeal nerves ascend in the tracheoesophageal groove, giving off branches to both the trachea and the cervical and upper esophagus. The vagal nerves join with the fibers of the sympathetic chain to form the esophageal plexus. Together with the esophagus, the vagi pass through the diaphragm and continue along the lesser curvature of the stomach.

• The sympathetic innervation comes from the cervical and thoracic sympathetic chains.

• Above and below the knee amputations require basic anatomy knowledge of the muscle compartments, nerves, and arteries of the lower extremity.

• The thigh has three compartments: anterior, posterior, and medial. The calf has four compartments: the anterior, lateral, or peroneal in addition to the deep and superficial posterior ones.

• The lower extremity is perfused by the superficial and deep femoral artery. The superficial femoral artery continues as the popliteal artery after exiting the Hunter’s canal. The popliteal artery bifurcates into tibialis anterior artery and the tibioperoneal trunk. The tibioperoneal trunk gives the fibular artery and continues as the posterior tibial artery. The femoral and sciatic nerves provide innervation to the lower extremity.

• A large operating room (OR) situated near the emergency department, elevators, and ICU should be designated as the Trauma OR to facilitate the logistics of patient flow and minimize transport. The room should be securable for high profile patients.

• A contingency plan for multiple simultaneous operations should be in place with the operating rooms in sufficient proximity to allow nursing and anesthesia cross-coverage and facilitate supervision of the surgical teams. Direct lines of communication between the OR, resuscitation area, ICU, other ORs, blood bank, and laboratory should be in place.

• All rooms should have ample overhead lighting as well as access to portable headlamps.

• Multiple monitors to display imaging, vital signs, and laboratory such as thromboelastometry, should be in place.

• Hybrid operating and interventional radiology teams should be familiar with operating in the hybrid room.

• A dedicated family waiting room should be identified, and all family should be directed to this area for the postoperative discussion.

• The brachial artery lies in the groove between the biceps and triceps muscles. The proximal brachial artery lies medial to the humerus and moves anterior as it progresses distally. At the antecubital fossa, it runs under the aponeurosis of the biceps muscle and typically bifurcates just below the elbow into the radial and ulnar arteries (Figure 37.1).

• The brachial artery is surrounded by two concomitant brachial veins, which run on either side of the artery. At the upper part of the arm, their confluence forms the axillary vein.

• The profunda brachial artery is a large branch that arises from the proximal third of the brachial artery and communicates with collateral circulation to the lower arm (Figure 37.2). Due to these collaterals, the lower arm may have adequate perfusion despite injury to the distal two thirds of the brachial artery.

• The basilic vein courses in the subcutaneous tissue in the medial aspect of the lower arm. At the mid arm, it penetrates the fascia to join one of the brachial veins.

• The cephalic vein is entirely in the subcutaneous tissues, courses in the deltopectoral groove, and joins the junction of the brachial and axillary veins.

• In the upper arm, the median nerve courses anterolateral to the brachial artery. It then crosses over the artery and lies posteromedial to the brachial artery as they pass under the aponeurosis of the biceps muscle.

• In the upper half of the arm, the ulnar nerve lies posterior to the brachial artery. In the mid arm, the nerve pierces the intermuscular septum and courses posteriorly away from the artery, behind the medial epicondyle.

• The overall pelvic anatomy and orientation of the pelvic organs is similar to the nongravid state (see Chapter 35 Emergency Hysterectomy) with the following exceptions:

  • Prior to the 12th week of pregnancy, the uterus is protected by the bony pelvis, but as it grows out of the pelvis, it becomes more susceptible to injury. By 20 weeks, the fundus reaches the umbilicus, and gestational age may be estimated by fundal height. The number of centimeters above the pubic symphysis corresponds to the estimated gestational age in weeks.

  • Physiologic changes in blood flow that result in diffuse engorgement of the uterine, ovarian, and salpingeal vasculature. Gravid or postpartum hysterectomies are more difficult and result in higher blood loss than when performed in the nongravid setting. Damage to this vasculature can quickly lead to exanguination.

• The duodenum lies in front of the right kidney and renal vessels, the right psoas muscle, the inferior vena cava, and the aorta (Figure 26.1).

• The duodenum is approximately 25 cm in length. It is the most fixed part of the small intestine and has no mesentery. It is anatomically divided into four parts:

  • The superior or first portion is intraperitoneal along the anterior half of its circumference. Superiorly, the first portion is attached to the hepatoduodenal ligament. The posterior wall is associated with the gastroduodenal artery, common bile duct, and the portal vein.

  • The descending or second portion shares a medial border with the head of the pancreas. It is bordered posteriorly by the medial surface of the right kidney, the right renal vessels, and the inferior vena cava. The hepatic flexure and transverse colon cross anteriorly. The common bile duct and main pancreatic duct drain into the medial wall of the descending duodenum.

  • The transverse or third portion is also entirely retroperitoneal. Posteriorly, it is bordered by the inferior vena cava and the aorta. The superior mesenteric vessels cross in front of this portion of the duodenum.

  • The ascending or fourth portion of the duodenum is approximately 2.5 cm in length and is primarily retroperitoneal, except for the most distal segment. It crosses anterior to and ascends to the left of the aorta to join the jejunum at the ligament of Treitz.

• The common bile duct courses laterally within the hepatodudenal ligament and lies posterior to the first portion of the duodenum and pancreatic head, becoming partially invested within the parenchyma of the pancreatic head. The main pancreatic duct then joins the common bile duct to drain into the ampulla of Vater within the second portion of the duodenum. The ampulla of Vater is located approximately 7 cm from the pylorus. The accessory pancreatic duct drains approximately 2 cm proximal to the ampulla of Vater.

• The vascular supply to the duodenum is intimately associated with the head of the pancreas. The head of the pancreas and the second portion of the duodenum derive their blood supply from the anterior and posterior pancreaticoduodenal arcades (Figure 26.2). These arcades lie on the surface of the pancreas near the duodenal C loop. Attempts to separate these two organs at this location usually results in ischemia of the duodenum.

• The majority of traumatic hemothoraces can be managed successfully with a chest tube placement.

• Retained hemothorax is defined as residual pleural blood >300–500 mL after initial thoracostomy tube evacuation.

• The gold standard for diagnosing retained hemothorax is a noncontrast CT scan of the chest. A chest X-ray is not reliable in the accurate diagnosis of retained hemothorax.

• VATS is usually contraindicated in patients with previous thoracic operations and in patients with respiratory failure or significant contralateral lung injury, such as contusion, atelectasis, or pneumonia, because single-lung ventilation may not be tolerated.

• Ideally, VATS should be done within the first 3–5 days. Early VATS (within 72 hours of admission) for evacuation of retained hemothorax reduces hospital length of stay, number of procedures, and cost. VATS is more difficult and less effective if performed more than 7–10 days after the injury, due to clot organization and dense adhesions.