Faculty Bibliography

OBJECTIVE: We describe a series of seven consecutive patients treated with endoscopically assisted transoral surgery for decompression of high cervical and clival abnormalities. METHODS: Seven endoscopically assisted transoral procedures were performed at the University of Florida from September 1999 to April 2000 for irreducible compression at the cervicomedullary junction. The abnormalities encountered were primary basilar invagination from congenital craniovertebral junction malformation (two cases), irreducible rheumatoid cranial settling (one case), secondary basilar invagination caused by migration of odontoid fracture fragments (one case), pseudogout granulation mass (one case), clivus chordoma (one case), and Chiari malformation with associated basilar invagination (one case). RESULTS: Successful decompression was achieved in all seven patients. There were no adverse neurological sequelae. One patient died from a perioperative myocardial infarction. At a mean clinical follow-up of 6.16 months, neurological status was noted to be stable or improved in all remaining patients. CONCLUSION: Endoscopically assisted transoral surgery represents an emerging alternative to standard microsurgical techniques for transoral approaches to the anterior cervicomedullary junction. Used in conjunction with intraoperative fluoroscopy, it provides a safe method for anterior decompression of the cervicomedullary junction without the need for extensive soft palate splitting, hard palate resection, or extended maxillotomy. Experience is required with greater numbers of patients and long-term follow-up to further validate this promising technique

Swallowing difficulties and dysphonia may occur in patients undergoing anterior cervical discectomy and fusion. The etiology and incidence of these abnormalities, however, are not well defined. In view of this, we performed a prospective, objective analysis of swallowing function and vocal cord approximation in patients undergoing anterior cervical discectomy and fusion. Twenty-three consecutive patients (22 male and one female, mean age 59 years) undergoing anterior cervical discectomy and fusion had standardized modified barium swallow study and videolaryngoendoscopy performed preoperatively and again at 1 week and 1 month postoperatively. Eleven patients (48%) had radiographic evidence of preoperative swallowing abnormalities. The majority of these patients had myelopathic rather than radicular findings (p = 0.03). None, however, had symptoms of swallowing dysfunction. Among these patients, one had worse function postoperatively, three had improvement, and function remained unchanged in seven. The preoperative swallowing assessment was normal in 12 patients (52%). Postoperative radiographic swallowing abnormalities were demonstrated in eight of these patients (67%). Preoperative vocal cord movement was normal in all patients. Postoperatively, vocal cord paresis was detected in two patients. The paresis was transient in one and permanent in the other. Age, previous medical history, operation duration, and spinal level decompressed were not significantly associated with the incidence of swallowing dysfunction. There was, however, a tendency for patients undergoing multilevel surgery to demonstrate an increased incidence of swallowing abnormalities on postoperative radiographic studies. In addition, soft tissue swelling was more frequent in patients whose swallowing function was worse postoperatively (p = 0.007). Postoperative voice and swallowing dysfunction are common complications of anterior cervical discectomy and fusion, although in the majority of patients these abnormalities are not symptomatic. Patients undergoing multilevel procedures are at an increased risk for these complications, in part because of soft tissue swelling in the neck

Six patients presented with either entrapped fourth ventricles or noncommunicating cerebrospinal fluid collections of the posterior fossa requiring drainage. These collections were treated with shunt systems whose proximal catheter was placed into the fourth ventricle via a coronal burr hole using an endoscope guided by Eleckta's ISG Viewing Wand. The technique and its advantages are described as are the complications and early outcomes

The effects of injury on peripheral nerve blood flow were studied, using a Laserflo blood perfusion monitor. A total of 11 nerves were studied, five normal and six injured nerves in four patients. Two of the patients had lacerating brachial plexus injuries, and two other patients had compressive neuropathies of their ulnar nerves at the elbow. All of the readings were taken intraoperatively while the patients were undergoing exploration and repair under general anesthesia. Measurements of the damaged nerves were taken serially from the site of injury proximally and distally, by approximating a flexible metric ruler to the dorsal aspect of the nerve along the same axis. In the acutely lacerated injured nerves (3 to 7 days), the measurements were taken at 1, 5, 10, and 20 mm. The maximal amount of retraction in any of the nerves was 1 cm; thus, the overall architecture of the nerves was maintained. In the compressed nerves, measurements were taken at 1, 2 and 3 cm proximal and distal to the medial epicondyle. Measurement of normal undamaged nerves was performed at six different sites along the same axis of the nerve. The averaged results indicate that the normal blood flow ranged from 47 ml/100 g/min to 63 ml/100 g/min, with a mean of 56 ml/100 g/min. In the injured nerves, blood flow was most depressed at sites closest to the laceration, and increased consistently and progressively at sites distant from the injury in both directions.(ABSTRACT TRUNCATED AT 250 WORDS)