Anatomy

Esophageal wall consists of serosa covering the short abdominal part and of adventitia on the rest of the organ. The muscle layer is uniquely arranged with longitudinal, circular and interconnecting oblique fibers. Striate muscles form the upper third and gradually give way to smooth muscle cells distally. And finally, submucous tissue and mucous membrane of multilayer non-keratinizing squamous cell epithelium, which is the firmest layer of esophageal wall. This fact has direct impact on surgical suture technique. Small isles of cylindrical cell epithelium may be present and predispose for ulcers. The Z-line marks the transition from esophageal to gastric epithelium.

Esophagus is 26cm long, starting 15cm from the incisors at the C6 level and transiting into the stomach with the Z-line located at 41cm (Th11-12 level), depending on one’s height. Esophagus is 1,5cm wide and its diameter can reach up to 3cm during swallowing. The cervical part (C6-Th2) runs between trachea (ventrally) and vertebral column (dorsally) and can be surgically approached from the left. The incision parallels the anterior border of sternocleidomastoideus muscle and consists in dissecting away common carotid artery, jugular vein, vagal nerve and protecting recurrent laryngeal nerves. The thoracis part (Th 2-Th9) is slightly S-shaped and runs in the posterior mediastinum behind trachea, aortic arch, right pulmonary artery and right main bronchus and is approach surgically via 5^th interspace thoracotomy. Then below Th5 vertebral body it traverses more to the left and is approach through 7^th interspace thoracotomy or left thoraco-phreno-laparotomy. The most aboral abdominal part starts at esophageal hiatus and phreno-esophageal membrane, is 3-5cm long and enters gastric cardia at the level of Th9, with sharp angle of His. Approach, usually impeded by left lateral liver segments (S2 and S3), can be gained through median laparotomy.

There are 3 narrowings:

1.     Upper esophageal sphincter (cricopharyngeal muscle) at C6 level

2.     Tracheo-bronchial crossing at 27cm

3.     Lower esophageal sphincter at the aboral end

There are weakened areas predisposing for diverticula formation. Zencker’s diverticulum can rise at the triangle formed by oblique fibers of inferior pharyngeal constrictor muscle (Killian’s sphincter) dorsally. Further, Laimer’s triangle is between cricopharyngeal muscle and esophageal muscles.

There is scarce blood supply, segmental arteries enter perpendicularly to the esophageal wall, the anastomosing network is poor. Vagal nerves bring parasympathetic supply. The right nerve turns dorsally and the left turns ventrally, as they pass down on the esophageal wall. Sympathetic fibers proceed from chest sympathetic trunks.

One-way passage of the mouthful is secured by various anti-reflux components. Upper esophageal sphincter precludes swallowing of air during breathing. Lower esophageal sphincter combines 8 contributing factors: the actual sphincter, angle of His, collapsible abdominal esophagus, gastro-esophageal junction attachments, motility coordination, gastric oblique muscle fibers, esophageal hiatus, mucosal rosette.

There are primary, secondary and tertiary peristaltic waves in the esophagus. Primary smooth muscle contraction passes towards gastric cardia. When the mouthful blocks, the subsequent distension proximal to the blockage triggers secondary peristalsis aiming to pass it on. Tertiary peristalsis is an uncoordinated wave.

Diagnostic tools

Contrast x-ray images display the shape of esophagus and may show stenosis, diverticulum, achalasia and hiatal hernia. Fluoroscopy swallow study evaluates peristalsis and motility disorders. Double (intravenous and peroral) contrast enhanced CT scans can determine type and extent of the pathology, contrast agent leakage proofs perforation or fistula. Endoscopic ultrasonography evaluates the depth of tumor infiltration and allows for biopsy. Endoscopy is a basic diagnostic and therapeutic method available. Macroscopic diagnostic yield may be enhanced using chromo-endoscopy (better mucosal lesions visualization after painting with acetic acid or narrow band imaging). Also, endoscopic microscopy is being developed (endoscopic cystoscopy, confocal laser endo-microscopy). Endoscopy enables for biopsies and therapeutic interventions like polypectomy, endoscopic mucosal resection, radio-frequency ablation, argon plasma coagulation, peroral endoscopic myotomy (POEM), treatment of bleeding, treatment of postoperative complications, introducing stents, balloon dilation (see gastroenterology for details). We also use PET/CT, manometry and pH-metry.

Esophageal disease

Atresia is a congenital obstruction of esophagus and may be associated with air-way fistula. There are 8 subtypes described by Vogt. Atresia presents with excessive salivation, aspiration pneumonia, coughing and cyanosis and with polyhydramnios prenatally. It is an indication for surgery.

The list goes on with fistula, stenosis, brachyesophagus, stricture, agenesis, heterotopic tissue, congenital cysts and duplication. Esophageal rings and membranes are localized intra-luminal protrusions. In Plummer-Vinson syndrome, there is a ring at the anterior wall of cervical esophagus. Schatzki ring is located at gastro-esophageal junction. Dysphagia lusoria is caused by external compression with either duplicated aortic arch or aberrant right subclavian artery.

Diverticula are sac-like extrusions of esophagus. True diverticulum includes all layers of esophageal wall, while false diverticulum consists of mucosa only. Pulsion, false diverticulum is produced by long-standing intraluminal hypertension in sphincter relaxation disorders. Traction, true diverticulum is pulled by a surrounding disease process. Zencker diverticulum (false, pulsion) is located at the triangle of Kilian. Epiphrenic diverticulum (false, pulsion) is related to lower esophageal sphincter dysfunction. Parabronchial diverticulum (true, traction) results from chronic inflammatory disease located around the bronchi. Diverticula are treated surgically or endoscopically.

Achalasia is a motility disorder given by an atypical or absent peristalsis with the lack of relaxation of the lower sphincter. Achalasia is divided into three types according to the Chicago classification: type I – classical form without any peristalsis, type II achalasia with panesophageal pressurization (most common), and type III achalasia with spastic contractions, which has the worst response to different types of treatment. There is dilation of the esophagus and the formation of megaesophagus. This is due to neuromuscular disc receptor failure. Chagas disease develops endemically in South America and is caused by Trypanosoma cruzi infection (achalasia on the basis of infection). It manifests with progressive dysphagia, pyrosis, food regurgitation, aspirations, repeated pneumonia, weight loss, retrosternal pain. Positive manometry findings are essential for diagnosis. Treatment options are Ca blockers, botulinum toxin, balloon dilation, laparoscopic esophagocardiomyotomy (Heller procedure) and POEM (Per-oral endoscopic myotomy). Achalasia increases the risk of squamous cell carcinoma. Pseudoachalasia has a clinical picture of achalasia, but is caused by another disease (e.g. esophageal cancer).

Barrett's esophagus is intestinal metaplasia (replacement of the squamous epithelium of the mucous membrane of the esophagus with cylindrical epithelium, which has an intestinal character in at least some sections) due to reflux esophagitis. It is a precancerous lesion. Patients with Barrett’s esophagus require regular follow up studies. Treatment consists in treating the underlying reflux.

Gastroesophageal reflux is the return of gastric contents to the esophagus caused by disorders of anti-reflux function. Small reflux is normal, but excessive reflux causes gastroesophageal reflux disease (GERD). There is desquamation of the squamous cell epithelium of the esophagus, inflammation (reflux esophagitis), metaplasia (see Barett's esophagus). According to the macroscopic endoscopic finding, reflux esophagitis is divided into several stages (e.g. Savary-Miller classification). However, microscopic esophagitis may be present with macroscopically normal findings. There is also an endoscopic negative reflux disease of the esophagus, when an endoscopic finding is normal, but the patient has recurrent reflux problems (non-erosive reflux disease, NERD).  The spectrum of symptoms is wide. Pyrosis, regurgitation, chest pain, odynophagia, pain in the epigastric region, vomiting, belching, extra-esophageal manifestations (hoarseness, chronic cough, globus sensation, pneumonia, laryngitis, mouth odor, cariesis). There may be stenosis of the esophagus, bleeding, malignancy. Diagnosis is made by endoscopic examination and pH-metry. Therapy consists in adjusting habits (eating smaller portions more often, not eating before lying into bed, limiting coffee, smoking, alcohol, weight reduction), antacids (only supplementally), proton pump inhibitors, complementary prokinetics. In case of insufficient effect of pharmacotherapy or in combination with hiatal hernia, surgical treatment is indicated. The principle is the creation of an anti-reflux cuff. The gold standard procedure is Nissen-Rossetti (360°) laparoscopic fundoplication. If short esophagus (brachy-esophagus) is found, Collis procedure preceeds the cuff formation leading to elongation of the esophagus. Other modifications of the cuff according to the degree of rotation are called Thal, Dor, Toupet or Belsey Mark IV (see pictures in the presentation).

Esophageal perforation can rarely be caused by open injury, but iatrogenic injury during endoscopy is far the most common (usually in narrowed areas or cervical esophagus) or as a complication of esophageal surgery. There is also spontaneous perforation of the esophagus, Boerhaave syndrome, which is caused by a sudden increase of intraluminal pressure, e.g. during vomiting. Most often, the rupture is located in the distal esophagus. It is one of the acute chest conditions, manifested by sudden chest pain, dysphagia; subcutaneous emphysema may be present as well (Mackler triad – vomiting, subcutaneous emphysema and severe pain). Perforation may also arise in esophageal cancer. The diagnosis is made with oral contrast enhanced chest CT. Esophageal perforation is a serious condition. Acute mediastinitis follows promptly, with subsequent severe sepsis. Emergency treatment consists in intensive treatment of septic shock and surgical drainage through thoracotomy. The approach is chosen according to the level of perforation: cervical part is approached through left cervical incision, proximal thoracic and distal esophagus are approached through left thoracotomy, perforation of the middle esophagus requires right thoracotomy. Fresh injury permits direct suture, with good quality mucous layer being the most important component of the repair. In late presentation, esophageal resection with neck esophagostomy and nutritive gastrostomy is the only applicable option. With the perspective of future reconstruction, gastrostomy at the small curvature or jejunostomy are preferred over conventional anterior wall gastrostomy. Minor perforations may be treated non-operatively (cervical esophagus) or with covered stent.

Repeated vomiting may lead to partial-thickness longitudinal tears in distal esophageal mucosa (Mallory-Weiss syndrome). The tears tend to bleed and depending on rate may stay asymptomatic or present as melanemesis, hematemesis and/or melena. Endoscopy makes the diagnosis and proton pump inhibitors and hemostatic therapy is applied.

Caustic injury is caused by ingestion of acid (coagulative necrosis), alkali (colliquative necrosis) or other chemicals. Its extent depends on the concentration of the substance and the time of exposure. It presents as odynophagia, retrosternal pain, shortness of breath (when swelling of glottis is present) and the development of shock. Three grades are distinguished: 1. swelling and hyperemia of the mucous membrane, 2. ulceration and fibrin deposition, 3. Full-thickness necrosis, perforation, strictures. With the history of ingestion, diagnosis and severity assessment is accomplished with endoscopy performed by an experienced operator, as there is high risk of perforation. Contrast enhanced CT can also rule out perforation and swallow contrast studies display chronic strictures. Analgesics are administered, possible shock is treated, immediate efforts to neutralize are possible by drinking more water. Furthermore, antibiotic therapy, corticosteroids and parenteral nutrition are administered. Esophageal resection with cervical esophagostomy is performed in cases of perforation. Chronic strictures are managed by endoscopic dilation or resection. After caustic injury, there is high risk of carcinoma, so endoscopic surveillance is warranted.

Swallowed foreign bodies most often get stuck in anatomical narrowed sites. Depending on the actual swallowed object, symptoms may vary in intensity, dysphagia and increased salivation may be present. Perforation and aspiration are the most serious complications, but most objects are passaged to the stomach. The diagnosis is determined by a history, a plain X-ray can reveal contrast objects and a swallow contrast study confirms perforation. Stuck objects are removed with endoscopy, surgery only being the option if other methods fail.

Esophageal varices are distal dilated veins of the submucous layer. They are a site of porto-caval shunting in portal hypertension (mostly with hepatic cirrhosis). Varices are graded by size into 4 degrees: I. slightly protruding nodules, II. markedly protruding nodules, III. Nodules occupying half of the lumen, IV. Nodules occupying more than half of the lumen. Variceal bleeding manifests by hematemesis and/or melena. In massive bleeding, hypovolemic shock and quickly passaged melena occur. Endoscopy serves both for establishing diagnosis and for treatment. Close monitoring, hemostatic medication (terlipresin, tranexamic acid, etamsylate), blood products (fresh frozen plasma, coagulation factors and erythrocytes). Hepatopathic coagulopathy further potentiates bleeding. If the bleeding is not controlled successfully, a Sengstaken-Blakemore tube is introduced. It has two balloons: gastric balloon compresses the cardia and holds the hanged tube in place and gastric balloon compresses the bleeding veins. Daniš's esophageal stent is another treatment option. In the long term, endoscopic sclerotization or ligation are used. TIPS (transjugular intrahepatic porto-systemic shunt) or surgical porto-caval shunt are used to reduce portal hypertension. For further information, see GIT hemorrhage.

Esophageal tumors can be divided into benign and malignant. There are epithelial, mesenchymal, neuroectodermal tumors, lymphomas and secondary tumors. Squamous papilloma is an example of benign epithelial neoplasia. Precancerous lesions include glandular or squamous intraepithelial neoplasia or dysplasia, either low grade or high grade. Malignant epithelial include adenocarcinoma NOS (not otherwise specified), adenoid cystic carcinoma, muco-epidermoid carcinoma, adeno-squamous carcinoma, squamous NOS carcinoma (venous, squamous, basaloid), undifferentiated NOS carcinoma, neuroendocrine tumor NOS (NET G1, G2, G3), neuroendocrine NOS carcinoma (large cell and small cell neuroendocrine carcinoma), mixed neuroendocrine cancer, adeno-neuroendocrine carcinoma (MANEC).  Mesenchymal benign tumors are represented by hemangioma, leiomyoma or lipoma. Malignant mesenchymal tumors list gastrointestinal stromal tumor (GIST), Kaposi sarcoma, leiomyosarcoma, rhabdomyosarcoma, synovial sarcoma. Neuroectoderm tumors include granular cell tumor and melanoma.

Tobacco smoking, alcohol abuse, Barett's esophagus, achalasia, HPV (Human papillomavirus), obesity, hot drinks, excessive spicy food consumption, hereditary factors, lack of dietary fruits and vegetables, esophageal caustic injury, Plummer-Vinson syndrome, Sjögren's syndrome – all contribute to the development of cancer. It clinically presents as retrosternal pain, odynophagia, dysphagia (first of food, later also of fluids), hoarseness, loss of weight, anemia. Tumor markers, endoscopy and biopsy, endoscopic ultrasound, CT and PET/CT are used to establish the diagnosis and stage. It is crucial to secure adequate nutrition by the means of peroral sipping, nasogastric tubes, PEG, gastrostomy, jejunostomy or parenteral nutrition. Therapy depends on the stage of the disease and histological type. Endoscopic intervention may offer radical cure in early stages (see methods above). More advanced stages are treated surgically. There is distinct classification of esophago-gastric junction carcinomas according to Siewert. Type I. - the tumor center is located 1 - 5 cm orally from EGJ, type II. - the tumor center infiltrates the EGJ, the tumor is localized from 1 cm orally to 2 cm aborally from the junction, type III. - the tumor center is localized 2 – 5 cm below the EGJ. While type I. warrants subtotal esophagectomy with proximal gastric resection, type II. and III. are treated with total gastrectomy with distal esophageal resection (see relevant chapter). Possible esophageal procedures include transhiatal esophagectomy without thoracotomy (Orringer), Ivor-Lewis esophagectomy with intra-thoracic anastomosis and McKeown esophagectomy with cervical anastomosis. Various approaches are used: left-sided thoraco-phreno-laparotomy, laparotomy and right thoracotomy, or a combination of mini-invasive methods where different phases of the operation are performed thoracoscopically and/or laparoscopically. The diseased esophagus is substituted with tubulised stomach, which is fed by right gastro-epiploic artery. If this option is not possible, colon or jejunum on vascular pedicle is used. Due to the facts mentioned above (the esophagus does not have serous layer, vascular supply is segmental, there are poor vascular anastomoses), these procedures bare high risk of complications, especially when it comes to the healing of anastomosis.

Radical surgery can be preceded or followed by neoadjuvant or adjuvant therapy respectively, depending on the staging. Chemotherapy alone or with concomitant radiation is used. Staging laparoscopy is sometimes used to exclude peritoneal carcinomatosis before neoadjuvant treatment is started and radical surgery planned. Ischemic conditioning may also be used, if dissemination is excluded. It means clipping left gastric artery and thus promoting neovascularization of the future graft. Chemotherapy, radiation, stent and gastrostomy may also be used with palliative intent.