Ronald I. Apfelbaum

Variations on the standard transsphenoidal approach to the sellar region, with emphasis on the extended approaches and parasellar approaches: surgical experience in 105 cases.

OBJECTIVE:The traditional boundaries of the transsphenoidal approach may be expanded to include the region from the cribriform plate of the anterior cranial base to the inferior clivus in the anteroposterior plane, and laterally to expose the cavernous cranial nerves and the optic canal. We review our combined experience with these variations on the transsphenoidal approach to various lesions of the sellar and parasellar region. METHODS:From 1982 to 2003, we used the extended and parasellar transsphenoidal approaches in 105 patients presenting with a variety of lesions of the parasellar region. This study specifically reviews the breadth of pathological lesions operated and the complications associated with the approaches. RESULTS:Variations of the standard transsphenoidal approach have been used in the following series: 30 cases of pituitary adenomas extending laterally to involve the cavernous sinus, 27 craniopharyngiomas, 11 tuberculum/diaphragma sellae meningiomas, 10 sphenoid sinus mucoceles, 18 clivus chordomas, 4 cases of carcinoma of the sphenoid sinus, 2 cases of breast carcinoma metastatic to the sella, and 3 cases of monostotic fibrous dysplasia involving the clivus. There was no mortality in the series. Permanent neurological complications included one case of monocular blindness, one case of permanent diabetes insipidus, and two permanent cavernous cranial neuropathies. There were four cases of internal carotid artery hemorrhage, one of which required ligation of the cervical internal carotid artery and resulted in hemiparesis. The incidence of postoperative cerebrospinal fluid fistulae was 6% (6 of 105 cases). CONCLUSION:These modifications of the standard transsphenoidal approach are useful for lesions within the boundaries noted above, they offer excellent alternatives to transcranial approaches for these lesions, and they avoid prolonged exposure time and brain retraction. Technical details are discussed and illustrative cases presented.

On the incidence, cause, and prevention of recurrent laryngeal nerve palsies during anterior cervical spine surgery.

Study Design. A retrospective review of contemporaneously acquired clinical data supplemented by experimental cadaver dissection. Objective. To establish the incidence and mechanism of vocal cord paralysis after anterior cervical spine surgery and to determine whether controlling for endotracheal tube (ET)–laryngeal wall interactions induced by the cervical retraction system could decrease the rate of paralysis. Summary of Background Data. Vocal cord paralysis is the most common otolaryngologic complication after anterior cervical spine surgery. However, the quoted frequency of this varies considerably, and the cause of the injury is not clearly defined. As a result, various, and at times contradictory, recommendations to prevent this are presented without data to support their effectiveness. Methods. Data gathered at the time of surgery and during follow-up visits on 900 consecutive patients who underwent anterior cervical spine surgery with plating during a 12-year interval were entered into a computerized database and reviewed for complications and procedural risk factors. After the first 250 cases an intervention consisting of monitoring ET cuff pressure and release of pressure after retractor replacement or repositioning was used, which allowed the ET to recenter within the larynx. The ET–laryngeal wall relation also was studied in fresh intubated cadavers using videofluoroscopic images, before and after retractor placement. Results. Thirty incidences of vocal cord paralysis consistent with recurrent laryngeal nerve (RLN) injury were identified: 27 temporary and 3 permanent. The rate of temporary paralysis decreased from 6.4% to 1.69% (P = 0.0002) after institution of the described maneuver. The findings confirmed that the retractor displaced the larynx against the shaft of the ET, allowing impingement on the vulnerable intralaryngeal segment of the RLN. Conclusions. The most common cause of vocal cord paralysis after anterior cervical spine surgery is compression of the RLN within the endolarynx. Monitoring of ET cuff pressure and release after retractor placement may prevent injury to the RLN during anterior cervical spinesurgery.

Anterior cervical fusion with the Caspar instrumentation system.

Twenty-eight patients with a variety of cervical spine abnormalities underwent anterior cervical spine stabilization with the Caspar osteosynthetic plate/intervertebral body bone graft technique. The available hardware and operative technique are presented, and case reports illustrate clinical applications. Complications and results of the series are presented. A brief discussion of applicable biomechanical principles and of technical pitfalls leading to potential fusion failures and a review of experience and developments in cervical plating techniques are included.

Neurenteric cysts of the posterior fossa: recognition, management, and embryogenesis.

Neurenteric cysts are endothelium-lined structures most commonly encountered in the lower cervical or upper thoracic spinal cord. The occurrence of neurenteric cysts within the cranial vault is unusual. We present three patients with neurenteric cysts located within the posterior fossa: one near the jugular foramen deforming the 4th ventricle, a second in the cerebellopontine angle, and a third in the prepontine cistern. Several different theories have been advanced to explain the embryogenesis of neurenteric cysts. We review these theories and conclude that cranial neurenteric cysts may arise from a disturbance of early gastrulation, shortly after the onset of primitive streak regression.

Vocal Fold Paralysis After Anterior Cervical Spine Surgery: Incidence, Mechanism, and Prevention of Injury

Objective Vocal fold paralysis is the most common otolaryngological complication after anterior cervical spine surgery (ACSS). However, the frequency and etiology of this injury are not clearly defined. This study was performed to establish the incidence and mechanism of vocal fold paralysis in ACSS and to determine whether controlling for endotracheal tube/laryngeal wall interactions induced by the cervical retraction system could decrease the rate of paralysis.

Anterior Fixation of Odontoid Fractures in an elderly Population

OBJECT Fractures of the odontoid process are the most common fractures of the cervical spine in patients over the age of 70 years. The incidence of fracture nonunion in this population has been estimated to be 20-fold greater than that in patients under the age of 50 years if surgical stabilization is not used. Anterior and posterior approaches have both been advocated, with excellent results reported, but surgeons should understand the drawbacks of the various techniques before employing them in clinical practice. METHODS A retrospective review was undertaken to identify patients who had direct fixation of an odontoid fracture at a single institution from 1991 to 2006. Patients were followed up using flexion-extension radiographs, and stability was evaluated as bone union, fibrous union, or nonunion. Patients with bone or fibrous union were classified as stable. In addition, the incidence of procedure- and nonprocedure-related complications was extracted from the medical record. RESULTS Of the 57 patients over age 70 who underwent placement of an odontoid screw, 42 underwent follow-up from 3 to 62 months (mean 15 months). Stability was confirmed in 81% of these patients. In patients with fixation using 2 screws, 96% demonstrated stability on radiographs at final follow-up. Only 56% of patients with fixation using a single screw demonstrated stability on radiographs. In the immediate postoperative period, 25% of patients required a feeding tube and 19% had aspiration pneumonia that required antibiotic treatment. CONCLUSIONS Direct fixation of Type II odontoid fractures showed stability rates > 80% in this challenging population. Significantly higher stabilization rates were achieved when 2 screws were placed. The anterior approach was associated with a relatively high dysphagia rate, and patients must be counseled about this risk before surgery.

Os odontoideum: presentation, diagnosis, and treatment in a series of 78 patients

OBJECT The most contentious issue in the management of os odontoideum surrounds the decision to attempt atlantoaxial fusion in patients with asymptomatic lesions. The authors examined the clinical presentation and outcome in patients with os odontoideum who underwent surgical stabilization, with an emphasis on 3 patients who initially received conservative treatment and suffered delayed neurological injury. METHODS Seventy-eight patients (mean age 20.5 years; median 15 years) were identified in a 17-year retrospective review. The median follow-up period was 14 months (range 1-115 months). Neck pain was the most common symptom (64%), and 56% of patients presented after traumatic injury. Eighteen patients had neurological signs or symptoms at presentation, and an additional 15 had a history of intermittent or prior neurological symptoms. Fifteen patients had undergone > or = 1 attempt at atlantoaxial fusion elsewhere. RESULTS Seventy-seven patients underwent posterior fusion and rigid screw fixation combined with a graft/wire construct: 75 had C1-2 fusion and 2 had occipitocervical fusion. One patient had an odontoid screw placed. Fusion was achieved in all patients at a median of 4.8 months (range 2-17 months). Approximately 90% of patients had resolution or improvement of their neck pain or neurological symptoms. CONCLUSIONS The authors believe that patients with os odontoideum are at risk for future spinal cord compromise. Forty-four percent of our patients had myelopathic symptoms at referral, and 3 had significant neurological deterioration when a known os odontoideum was left untreated. This risk of late neurological deterioration should be considered when counseling patients. Stabilization using internal screw fixation techniques resulted in 100% fusion, whereas 15% of patients had previously undergone unsuccessful wire and external bracing attempts.

Case reportsNeurenteric Cysts of the Posterior Fossa: Recognition, Management, and Embryogenesis

Neurenteric cysts are endothelium-lined structures most commonly encountered in the lower cervical or upper thoracic spinal cord. The occurrence of neurenteric cysts within the cranial vault is unusual. We present three patients with neurenteric cysts located within the posterior fossa: one near the

Atlantoaxial transarticular screw fixation: update on technique and outcomes in 269 patients.

BACKGROUNDTransarticular screw (TAS) fixation is our preferred method for stable internal fixation of the atlantoaxial joint because of its excellent outcomes, versatility, and cost-effectiveness. OBJECTIVEIn this article, we update our series of patients who have undergone TAS fixation, with attention to surgical technique, planning, complication avoidance, and anatomic suitability. METHODSWe retrospectively reviewed 269 patients (150 women, 119 men; average age, 52.9 years; age range, 17–90 years) who underwent placement of at least 1 TAS. In total, 491 TASs were placed for stabilization necessitated by various pathologic conditions. The mean follow-up period was 15.7 months (range, 0–106 months). RESULTSFusion was achieved in 99% of 198 patients monitored until fusion or nonunion requiring revision, or for 2 years. Forty-five patients had a complication, for a rate of 16.7%. Five early patients had vertebral artery injuries, 1 of which was bilateral and fatal. No recent patients had vertebral artery injuries. Other complications did not result in neurologic morbidity. Review of all atlantoaxial fusions by the senior author (R.I.A.) revealed that the TAS fixation technique could be successfully applied in 86.7% of sides considered. The main reasons for inapplicability were anatomic (recognized on preoperative planning) in 77% and abandonment secondary to concern about possible vertebral artery injury on the first side attempted in 13.8%. CONCLUSIONThe placement of TASs is safe and effective for stabilizing the atlantoaxial articulation. Refinements in technique, such as 3-dimensional stereotactic workstation for trajectory planning, have reduced the rate of serious complications. Clinical outcomes are excellent, with nearly 100% of patients achieving stable bony union.BACKGROUND Transarticular screw (TAS) fixation is our preferred method for stable internal fixation of the atlantoaxial joint because of its excellent outcomes, versatility, and cost-effectiveness. OBJECTIVE In this article, we update our series of patients who have undergone TAS fixation, with attention to surgical technique, planning, complication avoidance, and anatomic suitability. METHODS We retrospectively reviewed 269 patients (150 women, 119 men; average age, 52.9 years; age range, 17-90 years) who underwent placement of at least 1 TAS. In total, 491 TASs were placed for stabilization necessitated by various pathologic conditions. The mean follow-up period was 15.7 months (range, 0-106 months). RESULTS Fusion was achieved in 99% of 198 patients monitored until fusion or nonunion requiring revision, or for 2 years. Forty-five patients had a complication, for a rate of 16.7%. Five early patients had vertebral artery injuries, 1 of which was bilateral and fatal. No recent patients had vertebral artery injuries. Other complications did not result in neurologic morbidity. Review of all atlantoaxial fusions by the senior author (R.I.A.) revealed that the TAS fixation technique could be successfully applied in 86.7% of sides considered. The main reasons for inapplicability were anatomic (recognized on preoperative planning) in 77% and abandonment secondary to concern about possible vertebral artery injury on the first side attempted in 13.8%. CONCLUSION The placement of TASs is safe and effective for stabilizing the atlantoaxial articulation. Refinements in technique, such as 3-dimensional stereotactic workstation for trajectory planning, have reduced the rate of serious complications. Clinical outcomes are excellent, with nearly 100% of patients achieving stable bony union.

Thoracoscopic microsurgical excision of a thoracic schwannoma Case report

A 6-cm-diameter schwannoma located at T-2 was resected completely by using transthoracic microsurgical endoscopy. The partially cystic tumor widened the neural foramen and extended into the apex of the right thoracic cavity but did not extend intradurally. The tumor was accessed by means of three 15-mm incisions made in the intercostal spaces. The operative blood loss was only 200 ml, and there were no complications. The patient was discharged on the 2nd postoperative day and returned to full activity 1 week after surgery. Thoracoscopy provides an excellent alternative to thoracotomy for peripheral thoracic nerve sheath tumors that originate within the neural foramen or more distally along the intercostal nerves within the thorax. An anterior approach is required for intrathoracic tumors but is not suited for intradural tumors. An open posterior or posterolateral approach to the thoracic spine is required for intradural tumors to allow the dura to be closed adequately.