Bassem A. Georgy

BOLD and perfusion response to finger-thumb apposition after acetazolamide administration: differential relationship to global perfusion.

The authors studied the effects of altering global cerebral blood flow on both blood oxygen level–dependent (BOLD) response and perfusion response to finger-thumb apposition. A PICORE/QUIPSS II protocol was used to collect interleaved BOLD-weighted and perfusion-weighted images on eight finger-thumb apposition trials. Subjects were studied on a drug-free day and on a day when acetazolamide was administered between the second and third trials. After acetazolamide administration, resting cortical perfusion increased an average of 20% from preadministration levels, whereas the BOLD response to finger-thumb apposition decreased by an average of 35% in the S1M1 hand area. Contrary to predictions from the exhausted cerebrovascular reserve hypothesis and the oxygen limitation model, an effect of acetazolamide on cerebral blood flow response in the S1M1 hand area was not observed. Across the acetazolamide trials, BOLD response was inversely correlated with resting cortical perfusion for individual subject data. These results suggest that resting perfusion affects the magnitude of the BOLD response and is thus an important confounding factor in fMRI studies, and that the physiologic systems that increase cerebral blood flow in response to acetazolamide administration and systems that increase cerebral blood flow in response to altered neural activity appear to have additive effects.

Transcatheter snare removal of acute middle cerebral artery thromboembolism: technical case report.

OBJECTIVE AND IMPORTANCE We describe the case of a patient in whom a snare designed for the removal of foreign bodies was successfully used to retrieve a thromboembolism from the middle cerebral artery. This technique can be used to reestablish blood flow when maximal pharmacological therapies have failed. CLINICAL PRESENTATION A 38-year-old man with scrotal squamous cell carcinoma presented with the abrupt onset of left hemiparesis and numbness. Computed tomography of the head showed no hemorrhage or hypodensity, and right middle cerebral artery thrombosis was suspected. INTERVENTION Cerebral angiography demonstrated a near-total occlusion of the right middle cerebral artery at the M1-M2 junction. The administration of intra-arterial urokinase, systemic heparin, and systemic abciximab, and mechanical maceration failed to lyse the clot. A 4-mm goose-neck snare was guided through a microcatheter, and the clot was snared and withdrawn. Immediate postoperative angiography demonstrated the reconstitution of normal flow. Pathological examination of the snared material was consistent with clot. By postoperative Day 5, the patient had regained full strength, except for the fingers of the left hand, which remained moderately weak. Computed tomography demonstrated a right insular and extreme capsular infarct. CONCLUSION To our knowledge, this is the first reported use of a snare to remove clot in the setting of thromboembolic stroke. As the use of intra-arterial thrombolysis increases, transcatheter snare removal of pharmacologically resistant clot may be considered as a salvage strategy.

Metastatic Spinal Lesions: State-of-the-Art Treatment Options and Future Trends

SUMMARY: The purpose of this article is to review the current state of the art for treating symptomatic spinal fractures associated with malignant lesions and to present potential future trends in treatments for this patient population. Epidemiology, clinical presentation, and biomechanical ramifications of these lesions are summarized and treatment regimes, clinical outcomes, and complications and technical issues associated with treatments are presented. Potential future trends and new technologies for performing vertebral body augmentation in patients with metastatic spinal lesions are also discussed.

Clinical Experience with High-Viscosity Cements for Percutaneous Vertebral Body Augmentation: Occurrence, Degree, and Location of Cement Leakage Compared with Kyphoplasty

BACKGROUND AND PURPOSE: Vertebroplasty is known for its high leakage rate compared with kyphoplasty. In recent preclinical studies, high-viscosity cements were shown to significantly enhance the uniformity of cement filling and decrease the incidence of leakage in cancellous bonelike substrates compared with low-viscosity cements. In this study, the incidence and pattern of cement leakage by using a new high-viscosity cement (Confidence spinal cement system) was compared with that of standard kyphoplasty. MATERIALS AND METHODS: Postoperative radiographs of patients treated with either kyphoplasty or Confidence were analyzed for cement leakage by using a stringent and thorough 4-point scale (none, minimal, moderate, or severe). When leakage was observed, the location of the cement leakage was also recorded and described as diskal, venous, paravertebral, or epidural. Sixty-two consecutive patients with 112 treated levels were included in this retrospective review. There were 46 kyphoplasty- versus 66 Confidence-treated levels, which ranged from T3 to L5. RESULTS: The average vertebral collapse reached 27.9 ± 20.7% in the Confidence group versus 25.0 ± 19.1% in the kyphoplasty group. There was no or mild leakage in 92% of Confidence and 91% of the kyphoplasty cases (mild, 39% Confidence versus 50% kyphoplasty). Severe leakage was only reported in 1 (2%) Confidence and 1 (2%) kyphoplasty case. In both cases, the severe leakage was found in the disk space. No significant leakage that required any surgical intervention was noticed. CONCLUSIONS: This finding confirms prior observations that highly viscous cements may increase the safety of vertebral augmentation techniques compared with less viscous cements. The high-viscosity Confidence cement results in a leakage rate comparable with that of kyphoplasty.

Multicenter study to assess the efficacy and safety of sacroplasty in patients with osteoporotic sacral insufficiency fractures or pathologic sacral lesions

Objective To assess the outcomes and safety after CT-guided percutaneous sacroplasty in patients with painful sacral insufficiency fractures or pathologic sacral lesions. Methods A retrospective multicenter analysis of consecutive patients undergoing CT-guided sacroplasty for painful sacral insufficiency fractures or sacral lesions was undertaken. The inclusion criteria consisted of severe sacral pain not responding to conservative medical management with imaging evidence of unilateral or bilateral sacral insufficiency fractures or lesions. Outcome measures included hospitalization status (inpatient or outpatient), pre-treatment and post-treatment visual analog scale (VAS) scores, analgesic use and complications. Patients were followed at approximately 1 month and for at least 1 year after their sacroplasty procedure. Results Two hundred and forty-three patients were included in the study, 204 with painful sacral insufficiency fractures and 39 with symptomatic sacral lesions. The average pre-treatment VAS score of 9.2±1.1 was significantly improved after sacroplasty to 1.9±1.7 in patients with sacral insufficiency fractures (p<0.001). The average pre-treatment VAS score of 9.0±0.9 in patients with sacral lesions was significantly improved after sacroplasty to 2.6±2.4 (p<0.001). There were no major complications or procedure-related deaths. One patient who was treated for a sacral insufficiency fracture experienced radicular pain due to local extravasation of cement that subsequently required surgical decompression for symptomatic relief. Conclusions CT-guided percutaneous sacroplasty is a safe and effective procedure in the treatment of painful sacral insufficiency fractures or lesions. It is associated with prompt and durable pain relief and should be considered as an effective treatment option in this patient population.

Bone Cement Deposition Patterns with Plasma-Mediated Radio-Frequency Ablation and Cement Augmentation for Advanced Metastatic Spine Lesions

BACKGROUND AND PURPOSE: Combining percutaneous plasma-mediated radio-frequency (pmRF) ablation with vertebral body augmentation offers an alternative treatment to surgical intervention options for advanced metastatic spinal lesions and is particularly useful for cases with cortical destruction and/or epidural extension. This study evaluates bone cement deposition patterns and extravasation in treated vertebral bodies in relation to the metastatic lesion after using this combined approach. MATERIALS AND METHODS: Retrospective assessments of CT images performed before/after the procedures were evaluated in 37 patients (44 levels) with advanced metastatic lesions. A void was created in the anterior portion of the tumor-infiltrated vertebral body by using a bipolar plasma-mediated radio-frequency−based wand, followed by deposition of bone cement. Pain measured by visual analog scale score was recorded preprocedure and 2–4 weeks afterward. RESULTS: In 19 (43%) levels, 90%–100% of the cement was deposited in the anterior two thirds of the vertebral body. In 34 levels (77%), 75% or more of the cement was deposited in the anterior two thirds of the vertebral body. In 13/15 (86%) levels with posterior lesions, cement was deposited anterior to the lesion. No extravasation was observed in 13 levels (29.5%). Two clinically insignificant incidences of epidural extravasation were noted. Pain relief after the procedure was reported by 25/28 (89.5%) patients with available data. CONCLUSIONS: pmRF ablation may allow greater cement-deposition control, increasing the likelihood of successfully stabilizing the anterior two thirds of the vertebral body. This combined technique appeared particularly useful in cases with posteriorly located lesions. The incidence of cement extravasation was relatively high but clinically insignificant.

Fat-suppression contrast-enhanced MRI in the failed back surgery syndrome: a prospective study

We examined 25 patients with recurrent pain after lumbar disk surgery with MRI to evaluate the usefulness of gadolinium (Gd)-enhanced fat-suppression (FS) imaging in patients with failed back surgery. Pulse sequences included T1-weighted (T1W) images, Gd-enhanced T1W images, and Gd-enhanced T1W images with FS. The addition of FS to Gd-enhanced T1W images improved visualization of enhancing scar in all cases, helped distinguish scar from recurrent herniated disk, and showed more clearly the relationship of scar to the nerve roots and thecal sac. The images also demonstrated enhancement of the facet joints and theca in 23 and 11 cases, respectively. Intradural nerve roots were more conspicuous with FS in 21 cases. The combination of unenhanced and Gd-enhanced T1W images with FS is recommended for routine examination of the postoperative back.

Vertebroplasty Technique in Metastatic Disease

The purpose of this article is to review the current state of the art of using vertebral augmentation techniques for treating symptomatic spinal fractures that are associated with malignant lesions and to present potential future trends in treatments for this patient population. Epidemiology and biomechanical ramifications of these lesions are summarized, and treatment regimes, clinical outcomes, complications, and technical issues associated with treatments are presented. Potential future trends and new technologies for performing vertebral body augmentation in patients with metastatic spinal lesions are also discussed in this article.

Spinal Cord Stimulation: A Basic Approach

Chronic back pain and other refractory pain syndromes are a documented burden on our society. They also are a huge cost in quality of life and dollars spent on health care. Neuromodulation and specifically dorsal column stimulation of the spinal cord has been shown to decrease pain with minimal risk to the patient. We describe in this article the basic techniques and methods of both the stimulation trial and the permanent implantation of the leads and generator. With advanced imaging and the minimally invasive approach we further explain how to minimize any risk associated with this percutaneous procedure.

Percutaneous Cement Augmentations of Malignant Lesions of the Sacrum and Pelvis

BACKGROUND AND PURPOSE: Although cement augmentation has been described in the literature for the treatment of benign sacral insufficiency fractures, only a few case reports have described the procedures usage in the treatment of malignant lesions. The purpose of this study was to evaluate the feasibility, effectiveness, safety, and clinical outcome for percutaneous cement augmentation of patients with malignant lesions in the sacrum and pelvis. MATERIALS AND METHODS: A prospective study of 12 patients (7 men and 5 women) with a median age of 64.5 years was conducted under appropriate institutional review board protocol. Patients had different types of malignant metastatic lesions of the sacrum and pelvic bones. All but 1 patient underwent preprocedure CT and MR imaging. All patients had a postprocedure CT, and all but 1 had sacral lesions. Six patients had a second lesion in the iliac bones. Under CT guidance, percutaneous cement augmentation was performed in 8 cases and under fluoroscopy guidance in 2 cases. In 2 cases, needles were placed under CT guidance, and the injection was performed under fluoroscopy. In 5 patients, a single needle was used; in another 5 patients, 2 needles were used. One patient had 3 needles, and another patient required 4 needles. RESULTS: Adequate cement deposition was seen in all cases. Three patients had minimal clinically insignificant cement leakage. All treated patients (except 1 patient) reported decreased pain level with use of the visual analog scale (VAS) within 2 to 4 weeks of follow-up. No other subsequent surgical interventions were required. CONCLUSIONS: Percutaneous cement augmentation of metastatic lesions of the sacrum and pelvic bones is a feasible and safe technique that can be performed under CT or fluoroscopic guidance. The technique results in decreased pain relief on short-term follow-up that can allow patients to tolerate future treatment.