Esophageal cancer is among the 10 most frequent cancers in the world. The annual incidence reported in Western countries is 3 per 100,000, compared with 140 per 100,000 in Linxian Province in central China.1 Esophageal cancer remains one of the most lethal of all malignancies. Once a diagnosis is established, the prognosis is poor, with a 5-year survival rate of less than 10%. The results of single-modality treatment have been poor, with the exception of surgery for early esophageal cancer. Recently, neoadjuvant chemotherapy, radiotherapy, and combined chemoradiation therapy have been added as treatment modalities to enhance local control, increase resectability rates, and improve disease-free survival.2 The initial results of these multimodality treatments have been encouraging. Since management of esophageal cancer and survival of patients is stage-dependent, accuracy of clinical staging is vital. Recent advances in CT, MRI, and PET of the esophagus, as well as endoscopic ultrasound (EUS) and minimally invasive thoracoscopic/laparoscopic staging (Ts/Ls) offer new hope for reliable preoperative diagnosis and staging of patients with esophageal cancer.
The boundaries of the esophagus are the inferior cricopharyngeal constrictor proximally and the esophagogastric junction distally. The esophagus is composed of four layers: mucosa, submucosa or lamina propria, muscularis propria, and adventitia (Fig. 10-1). The esophagus has no serosa, providing a teleologic explanation for the ease of spread of esophageal cancer.
The four layers of the esophagus: mucosa, submucosa or lamina propria, muscularis propria, and adventitia.
Anatomically, the normal adult esophagus is approximately 35 cm in length and 2.5 cm in diameter, although it is not uniform throughout its course. The course of the esophagus begins in the midline in the upper neck at the level of the sixth cervical vertebra, which corresponds roughly to the level of the cricoid cartilage, and then deviates to the left in the lower neck and upper thorax. At the level of the tracheal bifurcation (24 cm from the incisors by endoscopic measurement), the esophagus again returns to the midline only to deviate to the left once again in the lower thorax, where it enters the abdomen through the diaphragmatic hiatus (40 cm from the incisors). Clinically, the esophagus is divided into three segments, the cervical, middle, and distal segments. The cervical segment ranges from the cricoid cartilage to the thoracic inlet (10–18 cm from the incisors). The middle esophageal segment ranges from the thoracic inlet to the midpoint between the tracheal bifurcation and the esophagogastric junction (19–34 cm). The distal esophageal segment extends from the midpoint between the tracheal bifurcation and the esophagogastric junction (35–44 cm). Three distinct narrowings are present in the esophagus. The first narrowing is formed by the cricopharyngeus muscle and is the narrowest segment of the gastrointestinal tract, located 12–15 cm from the incisors in the adult. The second narrowing is caused by the tracheal bifurcation and aortic arch at ...