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If dilatation and an antireflux operation do not relieve the esophageal obstruction, a reconstructive procedure, using either the stomach or colon for esophageal replacement, may be necessary to restore adequate swallowing function.
IV Tumors of the Esophagus
A Benign tumors
Leiomyomas are intramural smooth muscle tumors that account for two thirds of all benign neoplasms of the esophagus.
Symptoms. Dysphagia occurs when leiomyomas exceed a diameter of 5 cm as they grow within the muscular wall, leaving the overlying mucosa intact.
Diagnosis
A history of dysphagia is typical.
A barium swallow reveals a localized smooth filling defect in the esophageal wall.
Esophagoscopy is performed to confirm the diagnosis.
Biopsy of the lesion is contraindicated because it violates the mucosa, making subsequent surgical therapy difficult.
Endoscopic ultrasound (EUS) is very helpful in confirming the intramural location of the lesion.
Surgical treatment
In symptomatic patients, the tumor is enucleated from the esophageal wall without violating the mucosa.
A limited esophageal resection is indicated if the tumor lies in the lower esophagus and cannot be enucleated.
Benign intraluminal tumors are usually mucosal polyps, lipomas, fibrolipomas , or myxofibromas.
Symptoms are dysphagia, occasional regurgitation, and weight loss.
Diagnosis
Radiographs of the esophagus suggest the diagnosis.
Esophagoscopy is performed to confirm the diagnosis and to rule out malignancy.
Surgical treatment
Esophagotomy, removal of the tumor, and repair of the esophagotomy comprise the surgical treatment.
Endoscopy should not be used to remove these tumors because of the possibility of esophageal perforation.
B Malignant tumors
Incidence. In the United States, the incidence of esophageal carcinoma ranges from 3.5 in 1 million for whites to 13.5 in 100,000 for blacks. The highest incidence of esophageal carcinoma is noted in the Hunan Chinese population, with as many as 130 in 100,000 individuals affected.
Etiology. The exact cause is unknown. Associated factors are tobacco use, excessive alcohol ingestion, nitrosamines, poor dental hygiene, and hot beverages. Certain pre -existing conditions also increase the likelihood of developing esophageal cancer, including achalasia and Barrett's esophagus.
Pathology
Type
Squamous cell carcinoma is the most common form.
Adenocarcinoma , the next commonest, is the type that occurs in patients with Barrett's esophagus.
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Rare tumors of the esophagus include mucoepidermoid carcinoma and adenoid cystic carcinoma.
Tumor spread. Esophageal malignancies metastasize through both the lymphatic system and the bloodstream, with metastases occurring in liver, bone, and brain.
Diagnosis
A history of dysphagia and weight loss is almost always present.
Contrast study of the esophagus demonstrates the location and extent of the tumor.
Computed tomography (CT) scan of the chest and abdomen is done to evaluate local lymphatic spread, and a thorough search is made for distant metastases.
Esophagoscopy is essential for tissue diagnosis and determination of the extent of the tumor.
EUS is done to assess the depth of the invasion and staging.
Bronchoscopy is performed in patients with proximal esophageal lesions to assess the possibility of invasion of the tracheobronchial tree.
Treatment
Overall, surgical therapy is associated with less than a 5% mortality rate. Several procedures are described for resection of the esophagus.
Transhiatal esophagectomy through a laparotomy and cervical incisions. A complete thoracic esophagectomy is performed bluntly with reconstruction of gastrointestinal continuity with the stomach or, rarely, the colon.
Ivor Lewis esophagectomy through a right thoracotomy and laparotomy. Reconstruction is
also accomplished with the stomach or, rarely, the colon.
Radiotherapy and chemotherapy are currently being investigated as adjuncts to surgery or as primary treatment modalities.
Neoadjuvant platinum-based chemotherapy in combination with X -Ray Therapy (XRT) given before surgical resection appears to shrink the tumor mass. Several studies have shown an impact on long-term survival. Clinical phase II and III studies are now under way.
Combination chemotherapy with cisplatin have shown up to a 50% response rate. However, a significant long-term survival has not been demonstrated.
Radiotherapy alone for carcinoma of the esophagus results in a 5-year survival of less than 10%.
In patients who have advanced disease with either invasion of the tracheobronchial tree or advanced metastases, palliative effects may be obtained by utilizing endoscopically placed metallic stents to allow swallowing of saliva and soft foods.
V Perforation of the Esophagus
A Etiology
Perforations of the esophagus have two basic causes:
Iatrogenic causes instrumentation (e.g., esophagoscopy or dilatation) account for 50% of all esophageal perforations.
Trauma , blunt or penetrating, 20%
Boerhaave's syndrome (postemetic rupture of the esophagus), 15%
Rupture of the esophagus results in acute mediastinitis, which if not corrected is almost always fatal.
B Diagnosis
History. Patients give a recent history of instrumentation of the esophagus or severe vomiting. All patients complain of severe chest pain, which is usually most prominent in the area of the rupture.
Physical examination
Crepitation in the neck results from mediastinal air.
Occasionally, a crunching sound can be heard over the heart (Hamman's sign), which is caused by air in the mediastinum behind the heart.
Septic shock can also occur.
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Chest radiograph reveals air in the mediastinum and, possibly, a widened mediastinum.
If the perforation is in the lower esophagus, air may be present under the diaphragm within the abdomen.
If the pleura has been violated, a hydropneumothorax may be present.
A barium swallow should be performed if perforation is suspected. This study is preferred over esophagoscopy for identifying a perforation.
CT scan is also a very useful diagnostic modality.
C
Treatment is to perform primary repair with tissue buttress reinforcement, combined with wide mediastinal and pleural drainage.
If mediastinal inflammation is severe and tissue integrity markedly is compromised, then esophageal resection with cervical esophagostomy and placement of a gastrostomy tube are performed. Esophageal reconstruction is performed at a later date when the patient has sufficiently recovered.
VI Mallory-Weiss Syndrome
A Pathophysiology
This condition presents as acute upper gastrointestinal hemorrhage. The bleeding occurs in the lower esophagus, usually near the gastroesophageal junction, and is secondary to a partial-thickness tear in the lower esophagus, which follows a prolonged period of severe vomiting and retching. The tear usually extends into the stomach and may involve the greater curvature of the cardia.
B
Diagnosis is made by endoscopy, which is performed to locate the tear and to rule out other causes of bleeding.
C
Treatment is by supportive measures, such as blood volume replacement, antacids, and gastric lavage.
In most cases, the bleeding subsides spontaneously.
Exploratory laparotomy is performed with gastrotomy and suture of the tear of the esophagus from within the stomach if the bleeding persists. The lacerations are closed using continuous nonabsorbable sutures. A recurrence is rare.
VII Esophageal Webs
A
Upper esophageal webs are part of the Plummer -Vinson syndrome women with atrophic oral mucosa, anemia, and dysphagia. The web Treatment is usually by esophageal dilatation.
, which presents in middle -age, edentulous occurs just below the esophageal introitus.
B
Lower esophageal webs, or Schatzki's rings , commonly occur in patients with reflux. Patients have dysphagia. Treatment consists of esophageal dilatation and an antireflux procedure.
Chapter 11
Stomach and Duodenum
Ernest L. Rosato
Francis E. Rosato Jr.
I Stomach
A
The functions of the stomach are storage; emulsification; initial digestion by acidification and salivary amylase; and transmission of food to the duodenum.
BEmbryology
1.The stomach and duodenum are derived from a dilatation of the foregut during the fifth week of development.
2.The rate of growth of the left wall outpaces the right, thus forming the greater and lesser curvatures. Rotation of the stomach causes the left vagus to lie in the anterior position and the right vagus to lie in the posterior position.
3.The ventral and dorsal mesentaries of the foregut become the lesser and greater omentums, respectively, in adult life.
4.The stomach usually is situated between vertebral bodies T10 and L3 and is fixed at both the gastroesophageal junction and the proximal duodenum.
CAnatomy
(Fig. 11-1). The stomach has four parts and two sphincteric mechanisms.
1.Portions of the stomach
a.The cardia is the most proximal portion of the stomach, where it attaches to the esophagus. Immediately rostral to this area is the gastroesophageal (GE) junction. This transition zone is found 2–3 cm below the diaphragmatic esophageal hiatus and contains the lower esophageal sphincter mechanism.
b.The fundus is the most superior extension of the stomach, bounded by the diaphragm superiorly and the spleen laterally. The angle created by the fundus and the left lateral border of the esophagus is referred to as the angle of His.
c.The body, also referred to as the corpus, is the largest portion of the stomach. It consists of the lesser and greater curves. The incisura angularis creates an abrupt angle along the lesser curvature and marks the beginning of the antrum.
d.The antrum is the distal 25% of the stomach. It begins at the incisura angularis and ends at the pylorus.
2.Sphincters of the stomach
a.The lower esophageal sphincter (LES) is a physiologic sphincter. It is a high-pressure zone of muscular activity in the distal esophagus.
1.Relaxation with swallowing allows entry of food into the stomach.
2.Contraction prevents reflux of food from the stomach into the esophagus.
b.The pylorus is an anatomic sphincter muscle. It controls the flow of food from the stomach into the duodenum.
3.Arterial supply. The stomach has an extremely rich blood supply (Fig. 11-2), provided by the following vessels:
a.The left gastric artery (branch of celiac axis) supplies the lesser curvature (proximal).
b.The right gastric artery (branch of common hepatic artery) supplies the lesser curvature (distal).
c.The left gastroepiploic artery (branch of the splenic artery) supplies the greater curvature (proximal).
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FIGURE 11-1 Anatomy of the stomach.
d.The right gastroepiploic artery (branch of gastroduodenal artery) supplies the greater curvature (distal).
e.The vasa brevia (short gastric arteries arising from the splenic artery) supply the fundus and body.
4.Venous drainage of the stomach in general parallels the arterial supply but has some portal drainage.
a.The right gastric and left gastric (coronary) veins drain into the portal vein, while the right gastroepiploic vein drains into the superior mesenteric vein, and the left gastroepiploic vein drains into the splenic vein.
b.The left gastric vein (coronary vein) has multiple anastomoses with the lower esophageal venous plexus. These drain systemically into the azygous vein.
FIGURE 11-2 Arterial supply and venous drainage of the stomach. (From
McKenney MG, Mangonon PC, and Moylan JP, eds. Understanding Surgical
Disease. Philadelphia: Lippincott–Raven Publishers; 1998:118. Used by permission of Lippincott Williams & Wilkins.)
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5.The nervous innervation of the stomach is via parasympathetic and sympathetic fibers.
a.The vagus (parasympathetic) nerves stimulate parietal cell secretion, gastrin release, and gastric motility. Acetylcholine is the primary neurotransmitter used by the efferent fibers.
1.The left vagus nerve lies anterior to and left of the esophagus. It supplies branches to the anterior portion of the stomach and a hepatic branch to the liver, gallbladder, and biliary tree.
2.The right vagus nerve lies posterior to and right of the esophagus. It supplies branches to the posterior stomach and a celiac branch to the pancreas, small bowel, and right colon. Its first branch is called the criminal nerve of Grassi and is recognized as a cause of recurrent ulcer when left undivided.
3.The vagus nerves become the anterior and posterior nerves of Laterjet, which terminate at the pylorus as the “crow's foot.”
b.Sympathetic innervation is via the greater splanchnic nerves derived from spinal segments T5 through T10. These fibers terminate in the celiac ganglion, and postganglionic fibers follow the gastric arteries to the stomach. The afferent fibers are the pathway for perception of visceral pain.
6.Lymphatic drainage of the stomach is extensive but can be divided into four general zones. It is important to note that cancer anywhere in the stomach can spread equally to any zone.
a.Superior gastric nodes drain the upper lesser curve and cardia region.
b.Pancreaticolienal nodes drain the upper great curve and splenic nodes.
c.Suprapyloric nodes drain the antral segment of the stomach.
d.Inferior gastric/subpyloric nodes drain along the right gastroepiploic vessels.
7.The four layers of the stomach wall are the serosa, muscularis, muscularis mucosa, and mucosa.
a.The layers of muscle fibers found in the muscularis are the inner oblique, middle circular, and outer longitudinal.
b.The mucosal morphology is composed of distinctly different types of glands unique to the cardia, fundus/body,
