Sagittal septa, which forms retropharyngeal and retro-esophagial spaces, blocks the diffusion of abscess of this area to upper mediastinum, but abscess can diffuse via pretracheal space to the upper mediastinum and can cause a fatal complication. Pretracheal space is important in that it can be perforated, primarily during an esophagectomy. Recurrent laryngeal nerve RLN lies in tracheoesophageal sulcus, and esophagus is close to this nerve, which is important in case of cervical esophagectomy.
Injury of RLN causes unilateral difficulty in swallowing and hoarseness; bilateral injury causes closure of vocal cords in median position, and a tracheostomy becomes necessary. Especially on left side of esophagus, RLN is so close to esophagus that it is easy to injure a nerve with a careless dissection.
Thus, dissection should be made close to esophageal muscle fibers to avoid this complication. As previously mentioned, thoracic duct connects to left Pirogoff angle, and it makes a slight connection to left side of esophagus. To avoid harm to thoracic duct, a careful dissection should be made, especially in cervical esophagectomy [ 8 , 9 ].
Measuring 16—18 cm in length, thoracic esophagus is in upper and posterior mediastinum. Running from 1st to 11th dorsal vertebra, it does not fit concavity of vertebral column. However, it changes location to left gradually from start to end. At beginning, it is located between vertebral column and trachea, slightly left of midline and 5 cm left of vertebral column at level of diaphragmatic hiatus Figure 4. Parietal sheet of pleura is tightly connected to both sides of vertebral column, and these connections cause esophageal-pleural recesses that make dissection of esophagus in thorax more difficult.
Thus, if a pleural rupture occurs in this area during surgery, fixing rupture can present a challenge for surgeon [ 2 ]. Arteries of Esophagus.
As previously discussed, esophagus within thoracic cavity contains three classical narrowings, two conditional narrowings, and two curves. Most important and challenging structure in this region is thoracic duct, which lies behind esophagus throughout thorax. Thoracic duct is located slightly apart from esophagus in inferior third part of thorax, but it comes closer as esophagus goes upward.
Trachea, aortic arch, right pulmonary artery, left main bronchus, plexus of esophagus, pericardium, left atrium, and anterior vagus nerve are found anterior to esophagus. At posterior side, esophagus connects to vertebral column, longus colli muscle, posterior intercostal arteries, azygos vein, hemiazygos vein, anterior wall of aorta, posterior vagal nerve, and pleura. Aortic arch, left subclavian artery, left inferior laryngeal nerve, left vagus nerve, thoracic ductus, and thoracic part of aorta are located on left side of esophagus.
Azygos vein, pleura of mediastinum, right main bronchus, and right vagus nerve are located on right side. Close proximity of upper two-thirds of esophagus to thoracic duct increases risk of thoracic duct injury in middle and upper mediastinal dissection of esophagus; thus, careful dissection should be performed in this area. The area between aortic arch and esophagus is comprised of aorticoesophagial muscle fibers that include large vessels; dissection of this area is fairly simple, except in the case of tumor invasion.
If tumoral invasion occurs among these large vessels, removal is challenging and dangerous. Upper mediastinum becomes narrower above aortic arch, and esophageal tumors can easily infiltrate left recurrent laryngeal nerve and respiratory system; however, aortic arch and azygos vein block tumors in these areas to infiltrate lower parts of mediastinum. Lower parts of thoracic esophagus are surrounded by soft areolar tissue. Here esophagus is not touching adjacent organs and descends slightly away from the vertebral column, making dissection and resection easier and tumor infiltration more difficult in this area.
Two weak areas in esophagus that can be vulnerable to pulsing diverticula are upper and lower parts of a cricoid muscle. In addition, another weak area is located on left posterior esophageal wall, very close to diaphragmatic hiatus, spontaneous rupture of esophagus can occur [ 2 , 10 ].
Abdominal esophagus is 1—2. The plane passes through 7th rib cartilage and sternum anteriorly. It passes through esophageal hiatus of diaphragm, which is comprised of muscular fibers of right crus. The anterior side is longer than posterior side of esophagus because diaphragmatic crura are oblique.
Anterior and lateral sides are partially covered by visceral peritoneum, and posterior side is nonperitoneal side. Three ligaments connect esophagus to spleen, liver, and diaphragm. They are hepatogastric ligament, gastrosplenic ligament, and gastrophrenic ligament. Following structures are located near abdominal esophagus: posterior side segment of two-thirds of liver, left vagus nerve and esophageal plexus anteriorly, left and right crus of diaphragm, aorta and left inferior phrenic artery posteriorly, caudate lobe of liver at the right side, and fundus of stomach at left side.
Esophageal hiatus is located on right side of midline and is 2 cm in diameter. Topographically, it is located at 10th vertebral plane. Phrenoeosophagial ligament is primary part of antireflux mechanism that includes Gubaroff valvula and angle of Hiss Figure 5. This ligament consists of subpleural fascia, pleura, phrenoesophageal fascia, and transverse fascia of abdomen and peritoneum. This ligament makes gastroesophageal junction both flexible and tight [ 12 , 13 ]. Veins of Esophagus.
However, under hiatus, membrane is loose and long. Phrenogastric ligament lies between diaphragm and cardia of stomach and both vagus nerves. Vagus nerves hang esophagus to thoracic cavity; thus, cutting vagus nerves elongates esophagus 4—5 cm [ 2 ].
Inferior thyroid artery provides primary arterial flow to the cervical esophagus, and subclavian artery, main carotid artery, vertebral arteries, ascendant pharyngeal artery, superficial cervical artery, and costocervical trunk are other arterial blood flow providers to cervical esophagus.
Thoracic portion of esophagus takes blood flow from aorta, bronchial arteries, and right intercostal arteries. The abdominal esophagus is fed by left gastric artery, short gastric arteries, and descending branch of left phrenic artery. Inferior thyroid artery supplies arterial blood flow to cervical portion of esophagus Figure 6. An excessively low resection of cervical esophagus causes devascularization to this area.
In addition, aggressive resection and mobilization or laceration of bronchial artery, or cutting recurrent branches of left gastric artery and inferior phrenic artery causes devascularization at level of tracheal carina. Esophageal arterial blood flow is extremely rich and adequate for anastomosis, but a poor blood supply or careless or over aggressive dissection can cause anastomotic leakage in esophagus [ 14 — 16 ].
Relation among esophagus, diaphragm, and aorta with permission from Turkish Surgery Association. Venous system of esophagus begins at submucosal plexus, which perforates muscular layer and empties into azygos system. Cervical portions of venous drainage empty into inferior thyroid veins. Venous drainage of abdominal portions empties primarily into left gastric veins. Other veins that drain esophageal venous plexus are short gastric veins, splenic vein, left gastroepiploic vein, and branches of an inferior phrenic vein.
Lower esophageal veins connect to superior caval venous system by azygos and hemiazygos veins with multiple shunts, and other multiple shunts are located between inferior caval system and lower esophagus Figure 7. Retrograde flow of esophageal venous system causes venous dilatation and varices, and these varices can cause fatal bleeding [ 2 , 14 , 17 ]. Anti-reflux mechanism of esophagus.
Another band of muscle, the lower esophageal sphincter is at the bottom of the tube, slightly above the stomach. When a person swallows, these sphincters relax so food can pass into the stomach. When not in use, they contract so food and stomach acid do not flow back up the esophagus. As a person ages, the sphincters weaken, making some people more prone to backflow of acid from the stomach, a condition called gastroesophageal reflux disease GERD.
It is always best to seek medical attention if you are having those symptoms. Some people are sensitive to certain foods that lower the pressure of the lower esophageal sphincter and this allows the acid to wash up into the esophagus.
Anxiety also increases the sensitivity of the esophagus so the sensation is more severe. GERD can also cause esophagus ulcers. An ulcer is an open sore that, in this case, is located in the esophagus.
The esophagus is about inches 25 centimeters long and less than an inch 2 centimeters in diameter when relaxed. It is located just posterior to the trachea in the neck and thoracic regions of the body and passes through the esophageal hiatus of the diaphragm on its way to the stomach.
At the superior end of the esophagus is the upper esophageal sphincter that keeps the esophagus closed where it meets the pharynx. The upper esophageal sphincter opens only during the process of swallowing to permit food to pass into the esophagus. At the inferior end of the esophagus, the lower esophageal sphincter opens for the purpose of permitting food to pass from the esophagus into the stomach. Stomach acid and chyme partially digested food is normally prevented from entering the esophagus, thanks to the lower esophageal sphincter.
If this sphincter weakens, however, acidic chyme may return to the esophagus in a condition known as acid reflux. Acid reflux can cause damage to the esophageal lining and result in a burning sensation known as heartburn.
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