_Esophagoscopic Appearances in Pulsion Diverticulum_.--The esophagoscope will without difficulty enter the mouth of the sac which is really the whole bottom of the pharynx, and will be arrested by the blind end of the pouch, the depth of which may be from 4 to 10 cm. In some cases the bottom of the pouch is in the mediastinum. The walls are often pasty, and may be eroded, or ulcerated, and they may show vessels or cicatrices. On withdrawing the tube and searching the anterior wall, the subdiverticular slit-like opening of the esophagus will be found, though perhaps not always easily. The esophageal speculum will be found particularly useful in exposing the subdiverticular orifice, and through this a small esophagoscope may be passed into the esophagus, thus completing the diagnosis. Care must be exercised not to perforate the bottom of the diverticular pouch by pressure with the esophagoscope or esophageal speculum. The walls of the sac are surprisingly thin. [FIG. 101.--Pulsion diverticulum filled with bismuth mixture in a man of fifty years.] _Treatment of Pulsion Diverticulum_.--If the pouch is small, the subdiverticular esophageal orifice may be dilated with esophagoscopic bougies, thus overcoming the etiologic factor of spastic or organic stenosis. The redundancy remains, however, though the symptoms may be relieved. Cutting the common wall between the esophagus and the sac by means of scissors passed through the endoscopic tube, has been successfully done by Mosher. Various methods of external operation have been devised, among which are: (1) Freeing the sac through an external cervical incision and suturing its fundus upward against the pharynx, which has proved successful in some cases. (2) Inversion of the sac into the pharynx and suture of the mouth of the pouch. In a case so treated the pouch was blown out again during a fit of sneezing eight months after operation. (3) Plication of the walls of the sac by catgut sutures, as in the Matas obliterative operation for aneurysm. (4) Freeing and removing the sac, with suture of the esophageal wound. (5) Removal of the sac by a two-stage operation, in which method the initial step is the deliverance of the sac into the cervical wound, where it remains surrounded by gauze packing until adhesions have walled off the mediastinum. The work is completed by cutting off the sac and either suturing the esophageal wound or touching it with the cautery, and allowing it to heal by granulation. External exposure and amputation of the sac has been more frequently done than any other operation. Unless the pouch is large, it is extremely difficult to find after the surgeon has exposed the esophagus, for the reasons that at operation it is empty and that when the adhesions about it are removed the walls of the sac contract. After removal, the sac is disappointingly small as compared with its previous size in the roentgenogram, which shows it distended with opaque material.