Pleuroperitoneal Denver shunt insertion for the treatment of refractory chylothorax in a patient with tuberous sclerosis complex and lymphangioleiomyomatosis

Chylothorax is a well-recognised, common complication of lymphangioleiomyomatosis (LAM), a rare systemic disease often associated with tuberous sclerosis complex (TSC) and caused by mutations in the TSC genes. Constitutive activation of mammalian target of rapamycin (mTOR) causes proliferation of abnormal cells of smooth muscle lineage in the lungs and axial lymphatics, generally causing progressive decline in lung function. In LAM patients who develop chylothorax, recurrence is common and difficult to treat, although mTOR inhibition can be helpful. Ongoing chyle drainage via chest drain can lead to significant immunological, nutritional, and volume-related complications. Large chylothoraces are unlikely to respond to medical management alone and surgical intervention is typically indicated. Conventional surgical options include pleurodesis, pleurectomy, and thoracic duct ligation. We believe this is the first published account of successful treatment of chylothorax in LAM using a pleuroperitoneal shunt. A 45 year-old woman with TSC and LAM developed a symptomatic chylothorax (Fig. 1). After multiple drainages and treatment with everolimus (an mTOR inhibitor) for 6 months, she began to suffer significant physiological and functional decline. Her chest radiograph showed a pneumothorax with increased chylothorax and multiple thin-walled LAM cysts. Pleural fluid and blood analysis indicated a non-infected, nonmalignant chylothorax; her pneumothorax was improved by insertion of a chest drain. Everolimus levels had been within therapeutic limits for cardiac and renal transplantation, although there are few data in LAM. Low-fat diet with oral supplementation of mediumsized triglycerides (subsequently upgraded to total parenteral nutrition (TPN)) and octreotide was commenced in an effort to reduce chyle production. Intercostal catheter output, however, remained high, at 1–2 L/day. Everolimus was ceased in anticipation of surgery . Attempts to ligate laparoscopically the thoracic duct with pleurodesis and pleurectomy were unsuccessful. The treating teams then decided to insert a Denver pleuroperitoneal shunt, a silicone conduit consisting of a manually compressible unidirectional pump chamber with a catheter attached to each end. Peritovenous shunting was not appropriate due to the risk of air embolism from concomitant pneumothorax. The pleural catheter tip was inserted into the pleural cavity via thoracotomy, then tunnelled subcutaneously along the costal margin where the pump was embedded, enabling manual compression against the ribs. The peritoneal catheter was laparoscopically inserted into the peritoneal cavity where chyle could be reabsorbed. This successfully reduced the chylothorax, allowing removal of chest drains and successful pleurodesis. Over the following weeks, the patient’s nutritional, immunological, fluid balance, and renal function improved. LAM-chylothorax poses significant morbidity and mortality for affected patients. However, due to its extremely low prevalence, conventional treatments have not been widely evaluated, leaving optimal treatment poorly defined, particularly where complications are intractable to conventional management options. Small chylothoraces can be treated with low fat diet or TPN to reduce chyle volume. mTOR inhibitors are also often effective. However, their immunosuppressive effects would be hazardous in patients with an open portal such as a chest drain. Large chylothoraces, particularly with significant respiratory symptoms, require surgical management. Initially, decompression by a chest drain may provide symptomatic relief. However, it is unlikely to be curative and ongoing chyle drainage can lead to profound complications. Therefore, definitive surgical intervention should not be delayed. In patients where conventional surgical options have been exhausted, we propose that a pleuro-