A pig-tail catheter should be placed into the cavity percutaneously under radiological screening. A small quantity of radio opaque dye is used to ensure that the catheter is in the correct place. The pleural fibrosis surrounding the aspergilloma is usually so worked that substantial force is required to insert the trocar and the catheter does not ordinarily need to be sutured in place. The catheter can be left in for long periods (e.g. weeks) to allow repeated instillation of amphotericin B, but it may become infected.
Amphotericin B paste, which is warmed to about 35-40°C can be instilled at the same session that the catheter is inserted. The quantity required varies, depending on the cavity and aspergilloma size. It is best to insert the paste under radiological screening so that enough can be put in to obscure the aspergilloma by loss of the rim of air surrounding the aspergilloma. The cavity should not be over-filled. The optimal patient position can be determined by instilling some sterile saline and observing which position does not lead to immediate coughing. As all cavities in which aspergillomas are present are in continuity with the airways, it is best if the amphotericin B paste stays within the cavity for some hours after instillation. Correct patient positioning is important. If patient start to cough, the optimal position should be maintained and no more paste instilled. If the patient is allowed to sit up and all the paste then enters the bronchial tree, this can cause significant respiratory embarrassment, leading to pulmonary decompensation, the need for ventilation and in those with tenous pulmonary function, even death. Thus small quantities of paste are best instilled repeatedly, rather than large quantities on the first occasion.
Following amphotericin paste instillation, patients tend to cough repeatedly and often report bringing up both paste and other green or brown material. Some patients develop fever and feel systemically unwell. Monitoring of progress is best guaged radiologically initially and then by the intensity of cough and haemoptysis between installations of paste.
A typical treatment course with paste is 3-4 installations over 10-20 days, but some patients get substantial improvement after a single instillation.
Local instillation of paste can be combined with either oral itraconazole or intravenous amphotericin B therapy, especially if there is a suspicion of chronic invasive aspergillosis coexisting with the aspergilloma.
David W. Denning FRCP FRCPath FIDSA FMedSci
Professor of Medicine and Medical Mycology Director,
National Aspergillosis Centre Education and Research Centre
University Hospital of South Manchester (Wythenshawe Hospital)
Manchester M23 9LT UK