Dean Kostov

Intraoperative computed tomography image–guided navigation for posterior thoracolumbar spinal instrumentation in spinal deformity surgery

OBJECT Placement of thoracolumbar pedicle screws in spinal deformity surgery has a reported inaccuracy rate as high as 30%. At present, image-guided navigation systems designed to improve instrumentation accuracy typically use intraoperative fluoroscopy or preoperative CT scans. The authors report the prospective evaluation of the accuracy of posterior thoracolumbar spinal instrumentation using a new intraoperative CT operative suite with an integrated image guidance system. They compare the accuracy of thoracolumbar pedicle screw placement using intraoperative CT image guidance with instrumentation placement utilizing fluoroscopy. METHODS Between December 2007 and July 2008, 12 patients underwent posterior spinal instrumentation for spinal deformity correction using intraoperative CT-based image guidance. An intraoperative CT scan of the sterile surgical field was obtained after decompression and before instrumentation. Instrumentation was placed, and a postinstrumentation CT scan was obtained before wound closure to assess the accuracy of instrumentation placement and the potential need for revision. The accuracy of pedicle screw placement was later reviewed and recorded by independent observers. A comparison group of 14 patients who underwent thoracolumbar instrumentation utilizing fluoroscopy and postoperative CT scanning during the same time period was evaluated and included in this analysis. RESULTS In the intraoperative CT-based image guidance group, a total of 164 thoracolumbar pedicle screws were placed. Two screws were found to have breached the pedicle wall (1.2%). Neither screw was deemed to need revision due to misplacement. In the comparison group, 211 pedicle screws were placed. Postoperative CT scanning revealed that 11 screws (5.2%) had breached the pedicle. One patient in the fluoroscopy group awoke with a radiculopathy attributed to a misplaced screw, which required revision. The difference in accuracy was statistically significant (p = 0.031). CONCLUSIONS Intraoperative CT-based image guidance for placement of thoracolumbar instrumentation has an accuracy that exceeds reported rates with other image guidance systems, such as virtual fluoroscopy and 3D isocentric C-arm-based stereotactic systems. Furthermore, with the use of intraoperative CT scanning, a postinstrumentation CT scan allows the surgeon to evaluate the accuracy of instrumentation before wound closure and revise as appropriate.

In-stent thrombosis and stenosis after neck-remodeling device-assisted coil embolization of intracranial aneurysms.

BACKGROUND: Intrinsic thrombosis and stenosis are complications associated with the use of neck-remodeling devices in the treatment of intracranial aneurysms. OBJECTIVE: To examine the technical and anatomic factors that predict short- and long-term stent patency. METHODS: We undertook a retrospective review of 161 patients who underwent coil embolization of 168 ruptured and unruptured aneurysms assisted by the use of a neck-remodeling device. One hundred twenty-seven patients had catheter-based angiographic follow-up to evaluate 133 stent-coil constructs (mean, 15.4 months; median, 12.7 months). The technique of microcatheter jailing was used in a majority of patients; nonstandard stent configurations were also used. RESULTS: Clinical follow-up for all patients who had catheter-based angiograms demonstrated that among 133 stent constructs, a total of 9 (6.8%) had an in-stent event: 6 acute or subacute thrombosis (4.5%) and 3 delayed stenosis or occlusion (2.3%). Seven of these constructs were associated with a symptomatic event (5.3%). A significantly higher rate of in-stent events was seen with the use of constructs to treat anterior communicating artery aneurysms. When all patients are considered, including those who did not receive catheter-based follow-up imaging, 2 of 168 procedures (1.2%) resulted in the death of a patient, and procedural morbidity was 14.9%. CONCLUSION: From these results and those in the published literature, in-stent complication rates are low in carefully selected patients. The use of dual antiplatelet therapy, sensitivity assays, and glycoprotein IIb/IIIa inhibitors may decrease the rate of acute and chronic in-stent complications.

Endovascular treatment of basilar artery occlusion by manual aspiration thrombectomy

Background and purpose Basilar artery occlusion remains one of the most devastating subtypes of stroke. Intravenous and intra-arterial therapy have altered the natural history of this disease; however, clinical results remain poor. Therefore, exploring more aggressive and innovative management is warranted. Methods Six consecutive patients presenting with a basilar artery occlusion were treated with the same general algorithm of intra-arterial tissue plasminogen activator and mechanical thrombectomy with the Merci retrieval system. If complete recanalization was not achieved after two passes, manual syringe aspiration through a 4.3F catheter was employed. Results All interventions utilizing aspiration thrombectomy resulted in recanalization, with five out of six cases displaying TIMI3/TICI3 flow and one patient resulting in complete recanalization of the basilar artery with persistent thrombus in one P2 segment (TIMI2/TICI2B). All patients survived, with five out of six independent in activities of daily living at 3 months (mRS 0–2). Conclusions Our small case series indicates that aspiration thrombectomy performed manually through a 4.3F catheter can facilitate recanalization of basilar artery occlusion with acceptable clinical outcomes.

Fulminant Clostridium septicum Aortitis

An 87-year-old man was admitted to our cardiothoracic surgical service complaining of epigastric and interscapular pain of 3 days’ duration. His temperature was 101°F; white blood cell count, 19 100/mm3; and hemoglobin, 11.3 gm/dL. An ECG and serial cardiac enzyme measurements were negative for myocardial ischemia. An echocardiogram demonstrated normal left ventricular function, mild aortic stenosis, and mild biatrial enlargement. Mediastinal enlargement on chest film prompted a CT scan of the chest and abdomen. A gas collection dissecting the outer layer of the aortic wall was identified from the level of the left subclavian artery all the way down to the intra-abdominal …

Endovascular Revascularization of Chronic Symptomatic Vertebrobasilar Occlusion

Acute basilar artery occlusion is associated with a high risk of stroke, mortality, and poor outcome in survivors. Timely vessel revascularization is critical to improve the clinical outcome in this condition. A subset of patients survives acute occlusion with mild or no disability and some of these individuals develop recurrent ischemic events despite optimal medical therapy. The strategy for management of these patients is unknown.

Decompressive Hemicraniectomy, Strokectomy, or Both in the Treatment of Malignant Middle Cerebral Artery Syndrome

OBJECTIVE We sought to evaluate the impact of a craniotomy for strokectomy (CS) with bone replacement, decompressive hemicraniectomy (DHC), or DHC with a strokectomy (DHC+S) on outcome after malignant supratentorial infarction. METHODS We conducted a retrospective cohort study of cases of malignant supratentorial infarction treated by CS (n = 18), DHC (n = 17), or DHC+S (n = 33) at our institution from 2002 to 2008. End points included functional outcome measured by the modified Rankin Scale and incidence of mortality at 1 year. RESULTS Mean age, gender, side, vessel, and time from ictus to surgery were not statistically different between treatment groups. Stroke volume was significantly higher in the CS group. Operative time and blood loss were significantly higher in the DHC+S group. At 1 year, the median modified Rankin Scale score was 4 and overall survival was 71%. Functional outcomes and mortality for both the CS and DHC+S groups were not significantly different from the DHC group (P = 0.24). After adjusting for patient age, stroke volume, and time to surgery, there was no significant difference in outcome. CONCLUSION In patients with malignant supratentorial infarction, a strokectomy alone may be equivalent to a decompressive hemicraniectomy with or without brain resection.

Cavernous malformation tumors: a case study and review of the literature.

Objective: To summarize the current literature on the surgical management of cavernous malformations of the cerebellopontine angle in accordance with the experience at our institution. Methods: A systematic literature review on cavernous malformations of the cerebellopontine angle yielded 14 case reports relevant to the disease. In addition, the authors include their own report of a 16-year-old girl with such a lesion cured by surgical resection. Results: The most common clinical signs associated with this tumor are hearing loss (86.7%), followed by facial paresis (53.8%). Symptoms may be rapidly progressive. Cavernous malformations range from isointense to hyperintense to brain on noncontrasted T1 magnetic resonance imaging. In general, outcomes for patients with this tumor are favorable, with most patients cured by surgical resection. Conclusion: One of the rarest lesions of the cerebellopontine angle is a cavernous malformation. An understanding of the clinical and radiographic differences between this lesion and a vestibular schwannoma helps to minimize perioperative morbidity. Surgical resection should be performed with special attention to preserving facial nerve function.

Endovascular Treatment of Atypical Posterior Circulation Aneurysms: Technical Results and Review of the Literature

We report our technical success and complication rates in treating posterior circulation aneurysms at sites other than the basilar apex, superior cerebellar artery origin, or the posterior inferior cerebellar artery origin via endovascular embolization or sacrifice.

Lower extremity monoparesis after aneurysmal subarachnoid hemorrhage

Two patients presented with acute subarachnoid hemorrhage from a ruptured intracranial aneurysm. Both patients were treated via endovascular coil embolization, and both developed delayed lower extremity monoparesis without associated symptoms that resolved over the ensuing months. An extensive work-up lead us to propose the following hypothesis: the painless peripheral neuropathy likely resulted from nerve root irritation from abundant subarachnoid blood in the lumbar cistern.

Sinus pericranii: A case report

A healthy 6-week-old white male presented with an intermittently enlarging reddish-blue plaque on the midline forehead and frontal scalp. Neuroimaging revealed an abnormal vascular communication between the extracranial and intracranial venous systems. This rare condition is termed sinus pericranii. The authors provide a review of sinus pericranii and describe its imaging findings, embryologic derivation, differential diagnosis, and clinical management.