Spontaneous pneumomediastinum due to achalasia: a case report.

Abstract: Spontaneous pneumomediastinum (SPM) is a rare and benign clinical entity characterized by free air around mediastinal structures. Precipitating factors include violent cough, asthma, in-halational drugs, labor and exercise. We report a case of SPM due to achalasia which to the best of our knowledge, has never been reported. In achalasia, Valsalva maneuver might accompany severe vomiting. This causes alveolar rupture due to elevated intrabronchial and intra-alveolar pressure. Air tracks along the mediastinal spaces cause SPM. In our patient, there was no evidence of esophageal perforation. Tension pneumomediastinum and pneumothorax are complications of SPM.

Key Words: spontaneous pneumomediastinum, achalasia, esophageal perforation, pneumomediastinum, tension pneumomediastinum.

**********

Hamman syndrome or spontaneous pneumomediastinum (SPM) is defined as the presence of free air around mediastinal structures without any apparent etiology such as trauma. (1) SPM has been described in a wide variety of clinical scenarios including severe cough, asthma, labor, inhalation therapy, (2) diabetic ketoacidosis, (3) radiotherapy, (4) chemotherapy, (5) and exercise. (6,7) We present a patient with SPM and achalasia, which to the best of our knowledge, has never been reported.

Case Report

A 25-year-old man presented to the emergency department with pleuritic chest pain (CP), dysphagia, and nausea with intractable vomiting for 2 weeks. On examination, there was crepitation of the chest wall with Hamman sign present. Chest x-ray (CXR) revealed pneumomediastinum (PM) and bilateral pleural effusions. A Gastrografin esophagram was consistent with achalasia, and there was no leakage of contrast material into the mediastinum. Noncontrast computed tomography (CT) of the chest revealed PM, and a second scan the following day did not reveal any leakage of Gastrografin into the mediastinum. Upper endoscopy (EGD) was done on the day of presentation and revealed a narrowed distal esophagus and esophageal inflammation. Biopsy showed candidal esophagitis without evidence of malignancy. The C[D.sub.4] lymphocyte count was normal, and human immunodeficiency virus testing and urine drug screen were negative. The patient's symptoms improved with balloon dilation of the esophagus and fluconazole therapy. His diagnosis at discharge was SPM with coexistent achalasia and fungal esophagitis.

Discussion

The classic symptom triad of SPM includes chest pain, dyspnea and subcutaneous emphysema. Although the patient had clinical and radiographic evidence of SPM, his presenting symptoms of dysphagia and vomiting were atypical for SPM. Pneumomediastinum coexistent with achalasia is usually due to esophageal perforation from pneumatic dilation of the lower esophageal sphincter, (8) or rarely with botulinum toxin injection of the distal esophagus. (9) In this patient, severe vomiting and the resulting Valsalva maneuver might have caused a spontaneous rise in intrabronchial and intra-alveolar pressure. If a sufficient pressure gradient is generated, alveolar rupture occurs, allowing air to penetrate peribronchial and perivascular spaces of the mediastinum (the so-called Macklin effect) causing SPM. (10) Air also tracks along the visceral pleura causing pneumothorax. This complication usually occurs in thin, young individuals, (11-13) like the one described above. Absence of esophageal perforation (EP) on imaging and endoscopy, and the stable clinical condition of the patient points away from the diagnosis of spontaneous EP (Boerhaave syndrome) or EP from candidal esophagitis. (14-16) However esophageal motility disorders are known to cause candida/esophagitis due to stasis of food, (17,18) as might be the case in this patient. SPM is diagnosed by CXR findings in the appropriate clinical setting. Additional studies, including CT of the chest and esophagogram, are recommended to exclude other etiologies of PM. (11,12) SPM is a self-limiting condition which resolves spontaneously once the triggering factor is removed. A possible complication includes tension PM, which has been induced in laboratory animals by a continued increase in intrathoracic pressure. (10) This complication has not been reported in humans with SPM. EGD was pursued in this patient for symptom relief. This ensured blocking his Valsalva maneuver and cessation of high pressure in the alveoli, thereby preventing both worsening of SPM and tension PM. Management is conservative, typically with inpatient observation for about 48 hours, allowing the patient to rest and rule out other possible concomitant situations. A thoracostomy tube is required if pneumothorax is present. (11-13) Recurrences are rare. (12)

Conclusion

Although rare, SPM can occur due to achalasia in thin young patients, requiring a high index of suspicion for diagnosis. Urgent EGD with balloon dilation may be needed to prevent tension PM in this scenario. It may be reasonable to rule out EP with a Gastrografin esophagram.

References

1. Hamman L. Spontaneous mediastinal emphysema. Bull Johns Hopkins 1939;64:1-21.

2. Panacek EA, Singer AJ, Sherman BW, et al. Spontaneous pneumomediastinum: clinical and natural history. Ann Emerg Med 1992;21:67-72.

3. Weathers LS, Brooks WG, DeClue TJ. Spontaneous pneumomediastinum in a patient with ketoacidosis: a potentially hidden complication. South Med J 1995;88:483-485.

4. Kim KI, Lee JW, Lee MK, et al. Polypoid endobronchial Hodgkin's disease with pneumomediastinum. Br J Radiol 1999;72:392-394.

5. Sikdar T, MacVivar D, Husband JE. Pneumomediastinum complicating bleomycin related lung damage. Br J Radiol 1998;71:1202-1204.

6. Partridge RA, Coley A, Bowie R, et al. Sports-related pneumothorax. Ann Emerg Med 1997;30:539-541.

7. Morgan EJ, Henderson DA. Pneumomediastinum as a complication of athletic competition. Thorax 1981;36:155-156.

8. Bittinger M, Wienbeck M. Pneumatic dilation in achalasia. Can J Gastroenterol 2001;15:195-199.

9. Weusten BL, Samsom M, Smout AJ. Pneumothorax complicating botulinum toxin injection in the body of a dilated oesophagus in achalasia. Eur J Gastroenterol Hepatol 2003;15:561-564.

10. Macklin MT, Macklin CC. Malignant interstitial emphysema of the lungs and mediastinum as an important occult complication in many respiratory disease and other conditions; an interpretation of the clinical literature in the light of laboratory experiment. Medicine 1944;23:281-358.

11. Freixinet J, Garcia F, Rodriguez PM, et al. Spontaneous pneumomediastinum long-term follow-up. Respir Med 2005;99:1160-1163.

12. Jougon JB, Ballester M, Delcambre F, et al. Assessment of spontaneous pneumomediastinum: experience with 12 patients. Ann Thorac Surg 2003;75:1711-1714.

13. Abolnik I, Lossos IS, Breuer R. Spontaneous pneumomediastinum: a report of 25 cases. Chest 1991;100:93-95.

14. Jungbluth T, Bouchard R, Kujath P, et al. Complicated course of oesophageal perforations because of fungal infections. Mycoses 2005;48 (Suppl 1):41-45.

15. Tran HA, Vincent JM, Slavin MA, et al. Esophageal perforation secondary to angio-invasive Candida glabrata following hemopoietic stem cell transplantation. Clin Microbiol Infect 2003;9:1215-1218.

16. Koulmann P, Perez JP, Bonnet PM, et al. Candida albicans induced empyema: mode of revelation of a spontaneous oesophageal disrupture. Ann Fr Anesth Reanim 2003;22:470-473.

17. Ganatra JV, Bostwick HE, Medow MS, et al. Candida esophagitis in a child with achalasia. J Pediatr Gastroenterol Nutr 1996;22:330-333.

18. Hendel L, Svejgaard E, Walsoe I, et al. Esophageal candidosis in progressive systemic sclerosis: occurrence, significance and treatment with fluconazole. Scand J Gastroenterol 1988;23:1182-1186.

Savio Reddymasu, MD, Fathali Borhan-Manesh, MD, and Paul A. Jordan, MD

From the Section of Gastroenterology and the Department of Medicine, Louisiana State University Health Sciences Center, Shreveport, LA.

Reprint requests to Savio Reddymasu, MD, Louisiana State University Health Sciences Center, 1501 Kings Highway, PO Box #205, Shreveport, LA 71130. Email: [e-mail]

A short abstract of this case report was presented as a poster presentation at the American College of Gastroenterology 70th Annual Scientific Meeting, October 28-November 2, 2005, in Honolulu, HI.

Accepted January 24, 2006.

RELATED ARTICLE: Key Points

* Spontaneous pneumomediastinum (SPM) is defined as free air around mediastinal structures without any obvious etiology.

* SPM has not been reported with achalasia.

* SPM is common in thin, young individuals presenting with chest pain.

* SPM occurs due to tracking of air along mediastinal spaces following alveolar rupture, due to any condition which can cause Valsalva maneuver.

* Tension pneumomediastinum and pneumothorax are possible complications of SPM.