Retrocardiac lung hernia after thoracic esophagectomy: report of a rare case
© Furutani et al. 2015
Received: 23 February 2015
Accepted: 24 June 2015
Published: 14 July 2015
A retrocardiac lung hernia is an extremely rare complication after esophagectomy. A 56-year-old man was admitted to our hospital with advanced middle thoracic esophageal cancer and a giant bulla at the apical portion of the right lung. Since it appeared that dissection of the upper mediastinum would most likely require resection of the right bulla, a two-stage operation for esophageal cancer was planned. During the first-stage operation, thoracic esophagectomy and resection of the right giant bulla were performed. Fourteen days after the first-stage operation, the patient underwent laparotomy as the second-stage operation to reconstruct a narrow gastric tube via a retrosternal route. After the second-stage operation, the inflammatory reaction was prolonged. Therefore, a thoracoabdominal computed tomography scan was performed, showing retrocardiac pulmonary atelectasis. The patient was diagnosed with a retrocardiac left lung hernia in which the left lower lobe was displaced into the right thoracic cavity. Because the inflammatory reaction was due to effects of the lung hernia, a repair operation was performed via a left seventh intercostal thoracotomy. At thoracotomy, the left basal segment of the lung was atelectatic and reddish and had herniated into the right thoracic cavity through an opening between the aorta and pericardium. The herniated lung tip adhered strongly to the subcarina, and synechiotomy was performed. We believe that simultaneous removal of the right giant bulla with esophagectomy was the important cause of this complication.
Retrocardiac lung hernia is an extremely rare complication of esophagectomy that requires surgical repair, and to date, there has been only one published report describing such a complication . We encountered a case of retrocardiac lung hernia, and because it was an extremely rare case, we here report the details.
During the first-stage operation, right thoracic subtotal esophagectomy and cervicothoracic lymph node dissection were performed under general and epidural anesthesia. There was marked adhesion between the giant bulla and the chest wall, and bullectomy was performed. During dissection of the lower thoracic esophagus, an approximately 3-cm pleural window was made in the left mediastinal pleura, which led to a connection between the right and left thoracic cavities. The thoracic esophagus was dissected above the diaphragm, the mediastinal pleural window was not closed, a drainage tube was inserted from the right side of the thorax to the apical portion of the right lung, and the chest was closed. Esophagostomy was performed at the neck, while jejunostomy was performed by laparotomy. After the surgery, aspiration via a drainage tube at −10 cmH2O was performed continuously, and the drainage tube was removed on postoperative day 5. The patient’s course after the first-stage operation was uneventful, and no clear respiratory symptoms occurred. Although we gave the patient loxoprofen 600 mg/day and buprenorphine 0.4 mg/day as analgesic drugs in addition to epidural anesthesia, the patient complained of postoperative pain and was unable to expectorate sputum sufficiently.
In the present case, the mechanism of retrocardiac lung hernia development was likely due primarily to the resection of the giant bulla in the apical portion of the right lung. It is possible that, because the volume of the right thoracic cavity was reduced by the removal of the giant bulla, the left lung intruded into the right thoracic cavity to compensate for the reduced volume. In addition, the complication may have occurred because the contralateral pleura was opened at the time of dissection of the thoracic esophagus, as often happens, and because the left lung developed atelectasis as a consequence of insufficient expectoration of sputum due to postoperative pain. Thus, the left lung was likely displaced into the right thoracic cavity as a result of the combined effects of all of the above possible causes, resulting in the retrocardiac lung hernia.
Regarding continuous drainage in the thoracic cavity, we believe that the lung displacement occurred toward the side of continuous drainage. As we did in the present case, continuous drainage in the right thoracic cavity was performed by John et al.  in the published case of retrocardiac lung hernia, and in both cases, the left lung herniated into the right thoracic cavity. The pressure in the thoracic cavity on the side of the drainage became slightly lower than that in the contralateral thoracic cavity, and this may have caused the herniation to occur more easily.
In the present case, gastric tube reconstruction was performed via the retrosternal route. Therefore, the space created at the site of the esophagus could also have contributed to this complication. On the other hand, in the case of John et al. , the lung hernia developed between the heart and a gastric tube that was reconstructed via a retromediastinal route. Therefore, it remains unclear whether the reconstruction route could be the cause of a retrocardiac lung hernia.
CT and bronchoscopy are useful for the diagnosis of retrocardiac lung hernia. CT, in particular, should demonstrate an atelectatic lung in the retrocardiac position, making it easy to diagnose the hernia. During bronchoscopy, an occlusion due to the bending of the bronchus of the herniated lung is expected. Characteristically, although the bronchoscope can pass through the occluded part, it will not resolve the occlusion.
In our case as well as in that of John et al. , the patient needed surgical repair. In our case, because of the adhesion of the herniated lung to the sites of esophagectomy and cervicothoracic lymph node dissection, spontaneous recovery was unlikely. Thus, the most effective treatment for retrocardiac lung hernia may be synechiotomy via thoracotomy.
An extremely rare case of a retrocardiac lung hernia that developed after esophagectomy was described, which may have been caused by the removal of a giant bulla and the creation of a mediastinal pleural window. To prevent the development of a retrocardiac lung hernia, it is important to securely close the pleura after opening. Moreover, when the patient is unable to expectorate sputum sufficiently due to postoperative pain, adequate analgesia may be necessary to prevent lung atelectasis.
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