Esophagus

CHAPTER 18
Esophagus


Timothy Misselbeck and James Lee


Test Taking Tips


Some of the more common scenarios on the esophagus involve perforations: both iatrogenic and from cancer. Err on the side of being conservative: wide drainage, surgical diversion, and antibiotics being the cornerstone. Only consider a repair in low-risk situations such as early diagnosis of an iatrogenic perforation.


Benign esophageal disease is also frequently tested. The most common scenarios will involve chronic reflux, and how to manage iatrogenic perforations.


ANATOMY


Name the layers of the esophagus:


Mucosa and muscularis propria (esophagus has no serosa)


Image


FIGURE 18-1. Arterial blood supply of the esophagus. (Reproduced with permission from Rothberg M, DeMeester TR. Surgical anatomy of the esophagus. In: Shields TW, ed. General Thoracic Surgery. 3rd ed. Philadelphia: Lea & Febiger; 1989:84.)


What is the arterial blood supply to the cervical esophagus?


Inferior thyroid arteries (branch of thyrocervical trunk on left and subclavian artery on right)


What is the arterial supply to the thoracic esophagus?


Direct blood supply from 4 to 6 esophageal arteries off of the aorta; esophageal branches off of right (R) and left (L) bronchial arteries; supplemented by descending branches off the inferior thyroid arteries, intercostal arteries, and ascending branches of the paired inferior phrenic arteries


What is the arterial blood supply to the abdominal esophagus?


Left gastric artery and the paired inferior phrenic arteries


Describe the venous drainage for the cervical esophagus:


The submucosal venous plexus drains into the inferior thyroid veins (tributaries of L subclavian vein and R brachiocephalic vein)


Describe the venous drainage for the thoracic esophagus:


The submucosal venous plexus of the thoracic esophagus joins with the more superficial esophageal venous plexus and the venae comitantes that surround the esophagus at this level. This plexus then drains into the azygos veins on the right and the hemiazygous veins on the left.


Image


FIGURE 18-2. Venous drainage of the esophagus. (Reproduced with permission from Rothberg M, DeMeester TR. Surgical anatomy of the esophagus. In: Shields TW, ed. General Thoracic Surgery. 3rd ed. Philadelphia: Lea & Febiger; 1989:85.)


Describe the venous drainage of the abdominal esophagus?


Drains into both the systemic and portal venous systems through the L and R phrenic veins, and the L gastric (coronary) vein and short gastrics


In what direction is the lymphatic flow in the upper two-thirds of the esophagus?


Cephalad


In what direction is the lymphatic flow in the distal third of the esophagus?


Caudad


Describe the sympathetic innervation of the esophagus:


Cervical esophagus receives branches from the cervical sympathetic trunk (from superior ganglion in neck); the thoracic esophagus receives branches from the thoracic sympathetic trunk (from stellate ganglion), which form an esophageal plexus that envelops the thoracic esophagus anteriorly and posteriorly; the distal thoracic esophagus receives innervation from the greater and lesser splanchnic nerves.


The parasympathetic fibers to the esophagus arise from which cranial nerve?


Vagus nerve


The esophagus is composed of which 2 concentric muscle bundles?


Inner circular and outer longitudinal


What kind of muscle composes the upper one-third of the esophagus?


Striated muscle


What kind of muscle composes the lower two-thirds of the esophagus?


Smooth muscle


At what vertebral level does the esophagus enter the diaphragm through the esophageal hiatus?


T11


What are the areas of anatomical narrowing of the esophagus?


Cricopharyngeus muscle; compression by the left mainstem bronchus and aortic arch; diaphragm


What is the Z line?


The transition of the distal 1 to 2 cm of esophageal mucosa to cardiac mucosa/junctional columnar epithelium


Identification of gastroesophageal junction (external):


The collar of Helvetius (loop of Willis) and the gastroesophageal fat pad


Identification of gastroesophageal junction (internal):


The squamocolumnar epithelial junction (Z-line), provided the patient does not have Barrett.


The transition from the smooth esophageal lining to the rugal folds of the stomach.


PHYSIOLOGY


What are the 6 events that occur during the oropharyngeal phase of swallowing?


Elevation of the tongue, posterior movement of the tongue, elevation of the soft palate, elevation of the hyoid, elevation of the larynx, tilting of the epiglottis


Image


FIGURE 18-3. Swallowing process. Upper esophageal sphincter (UES), esophageal peristalsis, and lower esophageal sphincter (LES) in response to swallowing. (Reproduced from Doherty GM. Current Diagnosis and Treatment: Surgery. 9th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


What are primary peristaltic contractions of the esophagus?


Progressive contractions (2 to 4 cm/s) that move down the esophagus and reach the LES after the initiation of swallowing (~9 seconds)


What are secondary peristaltic contractions of the esophagus?


Progressive contractions generated from distention/irritation of the esophagus or from an independent local reflex to clear the esophagus of material that was left behind after a primary peristaltic wave rather than voluntary swallowing


What are tertiary contractions of the esophagus?


Uncoordinated contractions of smooth muscle that are nonprogressive, nonperistaltic, monophasic, or multiphasic simultaneous waves that can occur either after voluntary swallowing or spontaneously between swallows


Normal upper esophageal sphincter pressure at rest:


50 to 70 mm Hg


Normal upper esophageal sphincter pressure with food bolus:


12 to 14 mm Hg


DIVERTICULUM


Give examples of pulsion (false; mucosa and submucosa herniate through esophageal musculature) diverticula in the esophagus:


Zenker diverticulum and epiphrenic diverticulum


What esophageal diverticulum is a traction (true) diverticulum that results from external inflammatory mediastinal lymph nodes adhering to the esophagus that heal and contract and pull the esophagus resulting in the diverticulum?


Parabronchial (midesophageal) diverticulum


What side are midesophageal diverticula usually found?


Typically present on the right secondary to the overabundance of structures in the midthoracic region of the left chest.


Treatment for a midesophageal diverticula:


If asymptomatic patient with inflamed mediastinal lymph nodes from tuberculosis or histoplasmosis, treat medically with antituberculin or antifungal agents; if diverticulum <2 cm, observe; if patient symptomatic or diverticulum >2 cm, perform diverticulopexy (suspend from thoracic vertebral fascia) and a long esophagomyotomy is indicated in patients with severe chest pain or dysphagia and a documented motor abnormality.


Treatment for epiphrenic diverticulum:


If diverticula <2 cm, perform diverticulopexy; in patients with severe chest pain, dysphagia, or a documented motor abnormality, perform long esophagomyotomy: if diverticulopexy, begin long esophagomyotomy at the neck of diverticulum and extend onto LES), and if diverticulectomy, perform esophagomyotomy on opposite esophageal wall, extending from the level of the diverticulum onto the LES; if large associated hiatal hernia, perform diverticulectomy, long esophagomyotomy, and repair of hiatal hernia


Image


FIGURE 18-4. Epiphrenic diverticulum. (Reproduced from Doherty GM. Current Diagnosis and Treatment: Surgery. 9th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


Killian triangle (site of a Zenker diverticulum):


Point of potential weakness at the transition between the oblique fibers of the thyropharyngeus muscle and the horizontal fibers of the cricopharyngeus muscle


The surgical treatment of a Zenker diverticulum:


If diverticulum >3 cm—cricopharyngeal myotomy with diverticulectomy with TA stapler versus invert and perform diverticulopexy to precervical fascia If <2 cm—leave alone


Image


FIGURE 18-5. Pharyngoesophageal diverticulum (Zenker diverticulum). (Reproduced from Doherty GM. Current Diagnosis and Treatment: Surgery. 9th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


Image


FIGURE 18-6. The linear stapler is placed across the neck of the diverticulum. Note that the bougie is in place before transecting the diverticulum. (Reproduced from Zinner MJ, Ashley SW. Maningot’s Abdominal Operations. 11th ed. www.accesssurgery.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


BENIGN DISEASE


Most common site of esophageal perforation:


Cricopharyngeus muscle


Recommended first test in any patient presenting with dysphagia:


Video-esophagram


Indications for a video-esophagram:


Regurgitation, globus sensation, dysphagia, GERD, noncardiac chest pain, esophageal neoplasm


What characteristics of the esophagus help determine if a lower esophageal sphincter is mechanically defective?


Pressure <6 mm Hg, total length <2 cm, abdominal length <1 cm


What is the definition of a hypertensive lower esophageal sphincter?


LES with a sphincter pressure above the 95th percentile of normal


What are the manometric characteristics of achalasia?


Hypertensive LES resting pressure, incomplete or nonrelaxing LES, aperistalsis of the esophageal body, esophageal pressurization, and elevated lower esophageal baseline pressure


What is the gold standard for the diagnosis of achalasia?


Esophageal manometry


Term for a patient with achalasia with preserved muscle function as demonstrated by simultaneous contraction waves of the esophagus with various amplitudes:


Vigorous achalasia


Image


FIGURE 18-7. Esophageal achalasia. Note dilation of the esophageal body, retained barium, and distal esophageal narrowing (bird’s beak). (Reproduced from Doherty GM. Current Diagnosis and Treatment: Surgery. 9th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


What is presumed pathogenesis of achalasia?


Primary destruction of nerves to the LES with secondary degeneration of the neuromuscular function of the body of the esophagus from idiopathic or infectious neurogenic degeneration


What is the classic triad of presenting symptoms for achalasia?


Dysphagia, regurgitation, weight loss


What is the most common esophageal carcinoma identified with achalasia?


Squamous cell carcinoma


Standard surgical treatment for achalasia:


Heller myotomy


What are the classic manometry findings with diffuse esophageal spasm?

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Aug 13, 2019 | Posted by in ABDOMINAL MEDICINE | Comments Off on Esophagus
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