Correspondence

Images in Clinical Medicine: Echinococcal Cyst of the Pericardium

N Engl J Med 1995; 333:1572December 7, 1995

Article

To the Editor:

The patient with a huge hydatid cyst of the pericardium (July 20 issue)1 died, I suspect, because of the attempted removal of the lesion.

It is always tempting to remove such lesions in toto, in an attempt to avert rupture with local spillage and an inevitable local recurrence. The pathology of the disease, however, argues against an excision strategy. Hydatid cysts of the species Echinococcus granulosus, as clearly shown in this instance in the two computed tomographic scans and the photograph of the specimens, create a fibrovascular layer around themselves. This is nothing more than compressed host tissue with no surgical plane between it and the host organ. This layer provides physical support and allows the transfer of nutrients to the spherical cysts of the parasite within the pericystic cavity. Accordingly, hydatid cysts in soft-tissue organs cannot be enucleated, nor can the pericystic layer be removed by excision from within the host organ, without uncontrollable hemorrhage. A more practical surgical approach would be simply to “evacuate” the contents of the pericystic cavity and excise only redundant portions of the pericystic layer. Local recurrence occurs in about 11 percent of cases2 and can be guarded against by the proper walling off of the surgical field and the judicious use of scolicidal agents, such as 0.5 percent silver nitrate solution.3

Farrokh Saidi, M.D.
Modarress Hospital, Tehran, Iran 198446

3 References

1. 1

   Hall FM. Echinococcal cyst of the pericardium. N Engl J Med 1995;333:165-165
   Full Text | Web of Science | Medline

2. 2

   Mottaghian H, Saidi F. Postoperative recurrence of hydatid disease. Br J Surg 1978;65:237-242
   CrossRef | Web of Science | Medline

3. 3

   Saidi F, Nazarian I. Surgical treatment of hydatid cysts by freezing of cyst wall and instillation of 0.5 percent silver nitrate solution. N Engl J Med 1971;284:1346-1350
   Full Text | Web of Science | Medline

Author/Editor Response

The author replies:

To the Editor: The surgery that was contemplated in this patient was, I believe, simply to evacuate the contents of the pericystic cavity, as suggested by Dr. Saidi. The rupture of the cyst was unintended but probably not unexpected, because thoracotomy collapsed the contiguous lung. This rupture would not normally have been life-threatening. However, the decompression of the cyst resulted in the sudden reexpansion of the compressed left pulmonary artery. This vessel ruptured immediately after the rupture of the cyst. Unfortunately, the patient bled to death on the operating table.

Ferris M. Hall, M.D.
Beth Israel Hospital, Boston, MA 02215-5491