Subarachnoid-pleural fistula after resection of thoracic tumors

Object. Little has been written about the appropriate diagnosis, investigation, and management of subarachnoid-pleural fistula (SPF). The authors report a series of patients with SPF that developed after resection of spinal tumor and discuss the diagnosis and treatment of this entity. Methods. Between 1993 and 2002, nine patients with SPF observed after spinal surgery at the M. D. Anderson Cancer Center were prospectively followed. In all patients the tumors were located in the thoracic region, and the most common entity was vertebral body metastasis (six cases), with renal cell carcinoma being the most common form of the disease (three cases). All but one patient underwent surgery via a transthoracic approach; in only one patient an intradural approach was performed. The most common presentation was overt cerebrospinal fluid (CSF) leakage, manifesting as chest tube drainage (four cases) or as leakage through the wound (one case). A definitive diagnosis of SPF was established in four patients, with evidence of extraspinal leakage on an ¹¹¹In-radionuclide CSF study. Although all patients initially underwent a trial of lumbar CSF drainage, all but one required open repair, including creation of intercostal muscle (three cases) and omental (one case) flaps. Conclusions. After spinal surgery in which the thorax is entered, a diagnosis of SPF should be considered in any patient with abnormal chest tube output, persistent pleural effusion, or clinical evidence of intracranial hypotension. The diagnosis should be confirmed by performing a radionuclide-labeled CSF study. Definitive open repair is required in most cases and preferentially consists of a vascularized tissue graft, which is most easily obtained from an intercostal muscle flap.