Which of the following statement(s) is/are true concerning the blood supply and lymphatic drainage of the esophagus?

d.Nodal involvement in esophageal cancer is quite common even if the tumor is limited to the level of the submucosa

The blood supply and venous drainage of the esophagus are largely segmental. The inferior thyroid artery provides the main blood supply to the cervical portion of the esophagus. The thoracic portion of the esophagus receives its blood supply from two sources; branches from two or three bronchial arteries provide the proximal arterial supply and branches directly from the aorta supply the more distal thoracic esophagus. Intrathoracic mobilization of the esophagus during performance of antireflux procedures often require ligation of these branches. The venous plexus in the submucosa collects capillary blood and delivers it into a periesophageal venous plexus. The left gastric vein or coronary vein provides the principal collateral in portal hypertension when esophageal varices develop. The submucosal veins become much more superficial in the most distal esophagus, 1–2 cm above the gastroesophageal junction, and are consequently the most common site of bleeding in portal hypertension.

 The lymphatics of the esophagus form a rich submucosal network draining into regional lymph nodes in the periesophageal connective tissue. There is thus little barrier to longitudinal spread of cancer in the esophagus. Lymphatic drainage from the upper two-thirds of the esophagus is usually cephalad, but drainage from the lower one-third is in both directions. Although lymphatic metastasis in the esophagus generally involve the regional lymph nodes in proximity, nodal involvement may occur several centimeters away from the primary lesion because of the rich intramural lymphatic anastomotic channels. When a carcinoma is limited to the mucosa, the incidence of lymphatic metastases is low, but once into the submucosa, the incidence rises to 60%.