Segmental and global lordosis changes with two-level axial lumbar interbody fusion and posterior instrumentation.

BACKGROUND: Loss of lumbar lordosis has been reported after lumbar interbody fusion surgery and may portend poor clinical and radiographic outcome. The objective of this research was to measure changes in segmental and global lumbar lordosis in patients treated with presacral axial L4-S1 interbody fusion and posterior instrumentation and to determine if these changes influenced patient outcomes. METHODS: We performed a retrospective, multi-center review of prospectively collected data in 58 consecutive patients with disabling lumbar pain and radiculopathy unresponsive to nonsurgical treatment who underwent L4-S1 interbody fusion with the AxiaLIF two-level system (Baxano Surgical, Raleigh NC). Main outcomes included back pain severity, Oswestry Disability Index (ODI), Odom's outcome criteria, and fusion status using flexion and extension radiographs and computed tomography scans. Segmental (L4-S1) and global (L1-S1) lumbar lordosis measurements were made using standing lateral radiographs. All patients were followed for at least 24 months (mean: 29 months, range 24-56 months). RESULTS: There was no bowel injury, vascular injury, deep infection, neurologic complication or implant failure. Mean back pain severity improved from 7.8±1.7 at baseline to 3.3±2.6 at 2 years (p < 0.001). Mean ODI scores improved from 60±15% at baseline to 34±27% at 2 years (p < 0.001). At final follow-up, 83% of patients were rated as good or excellent using Odom's criteria. Interbody fusion was observed in 111 (96%) of 116 treated interspaces. Maintenance of lordosis, defined as a change in Cobb angle ≤ 5°, was identified in 84% of patients at L4-S1 and 81% of patients at L1-S1. Patients with loss or gain in segmental or global lordosis experienced similar 2-year outcomes versus those with less than a 5° change. CONCLUSIONS/CLINICAL RELEVANCE: Two-level axial interbody fusion supplemented with posterior fixation does not alter segmental or global lordosis in most patients. Patients with postoperative change in lordosis greater than 5° have similarly favorable long-term clinical outcomes and fusion rates compared to patients with less than 5° lordosis change.

Clinical and radiographic outcomes with L4-S1 axial lumbar interbody fusion (AxiaLIF) and posterior instrumentation: a multicenter study.

INTRODUCTION: Previous studies have confirmed the benefits and limitations of the presacral retroperitoneal approach for L5-S1 interbody fusion. The purpose of this study was to determine the safety and effectiveness of the minimally invasive axial lumbar interbody approach (AxiaLIF) for L4-S1 fusion. METHODS: In this retrospective series, 52 patients from four clinical sites underwent L4-S1 interbody fusion with the AxiaLIF two-level system with minimum 2-year clinical and radiographic follow-up (range: 24-51 months). Outcomes included back pain severity (on a 10-point scale), the Oswestry Disability Index (ODI), and Odom's criteria. Flexion and extension radiographs, as well as computed tomography scans, were evaluated to determine fusion status. Longitudinal outcomes were assessed with repeated measures analysis of variance. RESULTS: Mean subject age was 52 ± 11 years and the male:female ratio was 1:1. Patients sustained no intraoperative bowel or vascular injury, deep infection, or neurologic complication. Median procedural blood loss was 220 cc and median length of hospital stay was 3 days. At 2-year follow-up, mean back pain had improved 56%, from 7.7 ± 1.6 at baseline to 3.4 ± 2.7 (P < 0.001). Back pain clinical success (ie, ≥30% improvement from baseline) was achieved in 39 (75%) patients at 2 years. Mean ODI scores improved 42%, from 60% ± 16% at baseline to 35% ± 27% at 2 years (P < 0.001). ODI clinical success (ie, ≥30% improvement from baseline) was achieved in 26 (50%) patients. At final follow-up, 45 (87%) patients were rated as good or excellent, five as fair, and two as poor by Odom's criteria. Interbody fusion observed on imaging was achieved in 97 (93%) of 104 treated interspaces. During follow-up, five patients underwent reoperation on the lumbar spine, including facet screw removal (two), laminectomy (two), and transforaminal lumbar interbody fusion (one). CONCLUSION: The AxiaLIF two-level device is a safe, effective treatment adjunct for patients with L4-S1 disc pathology resistant to conservative treatments.

Posterolateral skull base reconstruction using the supraclavicular artery island flap.

The supraclavicular artery island (SAI) flap is a viable fasciocutaneous option for the reconstruction of head and neck defects. Although authors have reported success using SAI flaps for various reconstructive indications, concerns of a tenuous blood supply and distal ischemia have previously limited its use in the posterolateral skull base. This case series reports the outcomes of 5 consecutive patients receiving SAI flaps for posterolateral skull base reconstruction. All flaps were harvested in less than 1 hour with primary closure of all donor sites. A single patient developed superficial necrosis of the distal flap, which was repaired with a full-thickness skin graft. There were no other complications, and no donor site morbidity was observed. The SAI flap is an excellent option for the reconstruction of posterolateral skull base defects. The close color match, easy harvest within 1 hour, lack of microsurgical anastomosis, and absence of donor site morbidity support its continued utilization.

Retropharyngeal/anterolateral approach for C2 corpectomy.

Instability of the high cervical spine, particularly C1 and C2, is commonly treated via a posterior approach. Access to this region via transoral approaches is often avoided due to the high risk of wound contamination, limited exposure, and lack of experience on the part of the surgeon. We present a 48-year-old man exhibiting complete C2 vertebral body involvement by multiple myeloma with a pathologic fracture, which we treated via the anterolateral/retropharyngeal approach to the high cervical spine. The anterolateral/retropharyngeal approach provides relatively easy access to the anterior arch of C1 and to the vertebral bodies of C2-4 and can be applied to a variety of different conditions. In addition, this approach may be a viable alternative to the transoral route and its associated morbidities.

Recurrent lymphocytic hypophysitis and bilateral intracavernous carotid artery occlusion. an observation and review of the literature.

OBJECTIVES: Bilateral carotid artery occlusion associated with lymphocytic hypophysitis is exceedingly rare. We describe this association and review the literature. METHODS: The authors describe a 38-year-old woman with a history of severe headaches. Magnetic resonance (MR) imaging showed an intrasellar mass with invasion of both cavernous sinuses. Lymphocytic hypophysitis was diagnosed by transphenoidal biopsy. In the course of the disease, she developed symptoms of cerebral ischemia attributable to bilateral occlusion of her internal carotid arteries in both cavernous sinuses. She underwent bilateral superficial temporal artery-middle cerebral artery bypass surgery. RESULTS: The patient experienced progressive neurological recovery after surgery. A literature search revealed no other cases describing this unique association. CONCLUSIONS: Bilateral carotid artery occlusion may develop in the course of lymphocytic hypophysitis with cavernous sinus involvement. If indicated, cerebral revascularization should be performed to reverse cerebral ischemia.

Carotid endarterectomy without shunt: the role of cerebral metabolic protection.

BACKGROUND: The optimal method to protect the brain from hemodynamic ischemia during carotid endarterectomy (CEA) remains controversial. This study reports our experience with induced arterial hypertension and selective etomidate cerebral protection in a cohort of patients who underwent CEA without shunting and continuous electroencephalography (EEG) monitoring. METHODS: We reviewed retrospectively 102 consecutive CEAs performed in 102 patients with routine EEG monitoring and general anesthesia between March 1998 and October 2002. There were 65 (66%) symptomatic and 37 (34%) asymptomatic individuals. A protocol of induced arterial hypertension against EEG ischemic changes during carotid artery cross clamping was followed. Only patients with EEG changes refractory to induced hypertension went into etomidate-induced burst suppression. RESULTS: EEG changes were classified as mild, moderate and severe. Twenty patients (19.6%) developed asymmetric EEG changes, of which the great majority were mild and moderate (75%, p< 0.05). Seven patients with moderate (n=3) and severe (n=4) EEG changes needed etomidate cerebral protection. There were no mortalities and only one stroke (0.98%) is reported in the series. The morbidity rate was 6.8% and included transient cranial nerve palsies (n=5) and wound hematoma (n=1). CONCLUSIONS: Carotid endarterectomy can be safely performed with EEG monitoring and selective induced arterial hypertension and etomidate cerebral protection. Our results suggest that this method may be a good alternative for shunting and its inherent risks.

Thyrocervical trunk-external carotid artery bypass for positional cerebral ischemia due to common carotid artery occlusion. Technical note.

Medically refractory positional cerebral ischemia (PCI) and concomitant orthostatic hypotension associated with chronic common carotid artery (CCA) occlusion are rare. In this technical report, the authors describe an extracranial bypass in which the thyrocervical trunk was used as a donor vessel to treat three cases of CCA occlusion with PCI. Postoperatively, although orthostatic hypotension remained, ischemia-related symptoms resolved in all three patients and long-term graft patency was demonstrated. It is possible to treat cerebral ischemia due to CCA occlusion with extracranial bypass surgery. In these patients, the thyrocervical trunk proved to be a suitable donor vessel for the reconstitution of blood flow within the external carotid artery.

Postischemic reperfusion: ultrastructural blood-brain barrier and hemodynamic correlative changes in an awake model of transient forebrain ischemia.

OBJECTIVE: In nonrecovery models of cerebral ischemia, blood-brain barrier (BBB) and cerebral blood flow (CBF) changes are known to occur during reperfusion. It is unknown, however, whether those CBF and BBB alterations occur after brief, transient ischemia with neurological recovery. The purpose of this study was to characterize the time course of CBF and BBB ultrastructural changes during reperfusion in an awake, recovery model of transient global forebrain ischemia (GFI). METHODS: Forty-five adult Sprague-Dawley rats were subjected, while awake, to 10 minutes of GFI by the nine-vessel occlusion method. Thirty-five age-matched animals composed a sham-operated group. Normal control (n = 5), sham-operated (n = 5), and nine-vessel occlusion/reperfusion (n = 15) rats were selected for ultrastructural analysis. Electroencephalography was performed, and CBF, mean arterial blood pressure, and intracranial pressure were measured during ischemia and reperfusion up to 24 hours. Quantitative morphological analysis of cortical BBB capillaries was performed by transmission electron microscopy at the same time points at which specific CBF changes occurred during reperfusion. RESULTS: CBF decreased to 6% of preocclusion values during GFI. This correlated with coma and decerebrate rigidity. During reperfusion, short-lived hyperemia (225 +/- 18%, P < 0.001) was characterized by increased intracranial pressure (28.3 +/- 2.6 mm Hg, P < 0.001) and isoelectric electroencephalogram. This was followed by hypoperfusion, which reached a nadir of 59.7% (59.7 +/- 8.8%, P < 0.01) from baseline by 90 minutes. At this time point, the electroencephalogram recovered, and intracranial pressure and mean arterial blood pressure showed no abnormalities. By 8.5 hours, CBF returned to normal, and this coincided with complete recovery of the animal. Ultrastructural BBB analysis revealed astrocyte end-foot process edema and patent capillaries during hyperemia. Severe interstitial BBB edema and capillary lumen collapse was observed during hypoperfusion. Detachment and migration of pericytes was observed during hypoperfusion and beyond. CONCLUSION: A biphasic CBF response is elicited during reperfusion after brief nonlethal GFI under awake conditions.

Thyrocervical trunk-external carotid artery bypass for positional cerebral ischemia due to common carotid artery occlusion. Report of three cases.

Medically refractory positional cerebral ischemia and concomitant orthostatic hypotension associated with chronic common carotid artery (CCA) occlusion are rare. The authors detail their experience with three cases treated exclusively by an extracranial bypass in which the thyrocervical trunk was used as the donor vessel. Postoperatively grafts were patent and symptoms resolved in all three patients, although orthostatic hypotension remained. Postural cerebral ischemia due to CCA occlusion can be treated by extracranial bypass surgery. The thyrocervical trunk is a suitable donor for reconstruction of the external carotid artery in these cases.

Prognostic value of concordant seizure focus localizing data in the selection of temporal lobectomy candidates.

This study was performed to test the hypotheses that (a) resection of the temporal lobe epileptic focus, amenable to noninvasive as opposed to invasive localization, is associated with superior seizure outcome and (b) that quadruple (versus lesser degrees of) concordance of seizure focus localizing data predicts superior seizure-free outcome. Eighty-three patients underwent invasive (subdural-EEG) and/or noninvasive (video/scalp-EEG, SPECT, PET, MRI, neuropsychological testing) evaluation. All patients underwent anterior temporal lobectomy and amygdalohippocampectomy (ATL/AH) and seizure outcome was assessed at minimum one-year follow-up. At 34.8 +/- 2.5 months following ATL/AH, outcome was superior for patients in whom the seizure focus was amenable to noninvasive compared to invasive localization (80% versus 40% seizure-free, X2 = 14.03, p < 0.05). Seizure outcome was superior for patients with quadruple, compared to all lesser degrees of, concordance of seizure focus localizing data (85% versus 51% seizure-free, X2 = 7.34, p < 0.05). Post-ATL/AH, seizure outcome is superior in patients (1) harboring an epileptic focus amenable to noninvasive localization and (2) with quadruple concordance of seizure focus localizing data. These findings support the development of temporal lobectomy selection criteria including up to four invasive and/or noninvasive concordant seizure focus localizing techniques.

A model of global forebrain ischemia/reperfusion in the awake rat.

Anesthesia is an essential element during the induction of ischemia/reperfusion and cerebral blood flow (CBF) measurement in most animal models. Cerebral neuroprotection and intrinsic effects on CBF afforded by anesthetics are confounding variables in those models. A new model of global forebrain ischemia/reperfusion (GFIR) in awake rats is presented and characterized. Rats underwent permanent occlusion of the basilar, and the paired pterygopalatine, external carotid, and occipital arteries. Inflatable balloon occluders were inserted around both common carotids, the nine-vessel occlusion (9VO) preparation. A subgroup of 9VO rats underwent placement of a laser Doppler flowmetry (LDF) probe for measurement of cortical CBF. Twenty-four hours later, while awake, 9VO rats were subjected to 10 min of ischemia by occluding both common carotid arteries. Blood gases, glucose and hematocrit were analyzed before and during ischemia, and for up to 90 min during reperfusion. Behavioral observations and continuous LDF CBF and mean arterial blood pressure determinations during ischemia and reperfusion were made. Rats were rendered comatose and decerebrate rigidity was observed during 9VO. Following balloon deflation, rats immediately regained the righting reflex and achieved complete recovery in the next 24 h. Moderate hyperglycemia was observed at 5 min of ischemia and up to 90 min reperfusion in 9VO rats. LDF CBF decreased to 5% of baseline and remained unchanged during ischemia. The 9VO is a reproducible recovery model of GFIR. Behavioral and LDF CBF correlates are consistent and survival studies are feasible.