Detection of subarachnoid pleural fistula

Acquired Thoracic Fistulas

Fistulas are abnormal connections between 2 epithelial-lined structures. Thoracic fistulas may result from nonanatomic communications between spaces within the thorax, such as the lung, tracheobronchial tree, pleural space, and mediastinal structures, or between thoracic spaces and extrathoracic structures, such as the gastrointestinal tract. Furthermore, thoracic fistulas may result in communication between thoracic spaces and the spine or vascular structures. Potential causes include trauma, infection, neoplasm, surgical intervention, or medical syndromes. In this article, we discuss various acquired thoracic fistulas and their potential causes, key multimodality imaging manifestations, and clinical significance.

Subarachnoid-pleural fistula: applied anatomy of the thoracic spinal nerve root

Subarachnoid-pleural fistula (SPF) is a rare complication of chest or spine operations for neoplastic disease. Concomitant dural and parietal pleural defects permit flow of cerebrospinal fluid into the pleural cavity or intrapleural air into the subarachnoid space. Dural injury recognized intraoperatively permits immediate repair, but unnoticed damage may cause postoperative pleural effusion, intracranial hypotension, meningitis, or pneumocephalus. We review two cases of SPF following surgical intervention for chest wall metastatic disease to motivate a detailed review of the anatomy of neural, osseous, and ligamentous structures at the intervertebral foramen. We further provide recommendations for avoidance and detection of such complication.

[Massive pneumocephalus and cerebrospinal fluid fistula after thoracotomy]

We report the case of a 70-year-old man (ASA physical status 2) who developed massive pneumocephalus caused by a fistula between the subarachnoid and pleural spaces following a left pneumonectomy. After an uneventful immediate postoperative period, the patient was readmitted to the recovery care unit with dyspnea, intense headache, confusion, and diminished level of consciousness. Computed tomography confirmed a cerebrospinal fluid fistula secondary to the opening of the intradural space during tumor resection. Treatment was conservative, consisting of rest in a slightly Trendelenburg position, antibiotic prophylaxis to prevent meningitis, and a water seal on the thoracic drainage tube.

Traumatic subarachnoid-pleural fistula in a dog

Subarachnoid-pleural fistula is a rare occurrence in humans as a result of trauma or spinal surgery. Such fistulas commonly remain undiagnosed until sufficient cerebrospinal fluid accumulates in the pleural space to cause respiratory distress. We describe a subarachnoid-pleural fistula in a dog that occurred subsequent to blunt trauma sustained during a fall, with concurrent acute, traumatic intervertebral disc rupture. The extruded disc material penetrated the dura mater, allowing communication between the subarachnoid space and the extrapleural thoracic cavity. Radiographic, myelographic, and computed tomographic (CT) findings are reviewed. Abnormalities noted during myelography included an intradural-extramedullary lesion at T11-T12, with epidural leakage of contrast medium from the region of T12 extending cranially. In images from myelography and CT there was extravasation of contrast medium extending from the subarachnoid and epidural space into the extrapleural thoracic cavity.

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.

Treatment of the subarachnoid–pleural fistula

Subarachnoid–pleural fistula is a rare type of cerebrospinal fluid (CSF) fistula, and there are only several cases reported in the literature. The authors describe a 65-year-old male patient in whom a diagnosis of T7–8 disc herniation had been made. He underwent surgery via a right lateral extracavitary approach. Postoperatively he developed progressive respiratory distress and headache. A chest x-ray film revealed a pleural effusion, and computerized tomography (CT) myelography demonstrated a subarachnoidal-pleural fistula at the level at which the herniated disc had been removed. The patient had been managed via a CSF drainage system and a chest tube. He was discharged after relief of symptoms was attained. Subarachnoid–pleural fistulas can be secondary to traumatic injury and surgery, or they can be spontaneous. Patients present with rapidly filling pleural effusion and headache. A diagnosis can be established using CT myelography or myeloscintigraphy. Treatment is conservative, with the placement of a chest tube and insertion of a CSF drainage catheter, and surgical repair should be considered only if the conservative therapy fails.

Pneumocephalus complicating routine thoracotomy: symptoms, diagnosis and management

Pneumocephalus resulting from a subarachnoid-pleural fistula most commonly occurs after trauma. Such a complication is very rarely seen after thoracotomy alone, with 15 cases reported to date in the literature. We report a case of pneumocephalus and subarachnoid-pleural fistula that developed secondary to thoracotomy. It was diagnosed by postmyelography computed tomography and treated with open surgical repair after a trial of conservative therapy failed. The presenting symptoms and signs, diagnostic methods, and options for therapy are reviewed.