Safety and effectiveness of percutaneous sacroplasty: a single-centre experience in 58 consecutive patients with tumours or osteoporotic insufficient fractures treated under fluoroscopic guidance.

OBJECTIVE: To report our experience in percutaneous sacroplasty (PSP) for tumours and insufficiency fractures of the sacrum. METHODS: Single-centre retrospective analysis of 58 consecutive patients who underwent 67 PSPs for intractable pain from sacral tumours (84.5 %) or from osteoporotic fractures (15.5 %). The following data were assessed: visual analogue scale (VAS) before and after the procedure for global pain; short-term (1-month) clinical follow-up using a four-grade patient satisfaction scale (worse, unchanged, mild improvement and significant improvement); modification in analgesics consumption; referred short-term walking mobility. Minor and major complications were systematically assessed. RESULTS: The mean VAS score was 5.3 ± 2.0 in pre-procedure and 1.7 ± 1.8 in post-procedure. At 1-month follow-up, 34/58 (58.5 %) patients experienced a mild improvement; 15/58 (26 %) presented a significant improvement while 4/58 (7 %) and 5/58 (8.5 %) patients had unchanged or worse pain, respectively. Decreased analgesic consumption was observed in 34 % (20/58) of the patients. Eighty percent of patients with walking limitation experienced improvement, 16 % remained unchanged and 4 % were worse. We noted minor complications in 2/58 patients (3.4 %) and major complications in 2/58 patients (3.4 %). CONCLUSION: Percutaneous sacroplasty for metastatic and osteoporotic fractures is a safe and effective technique in terms of pain relief and functional outcome. KEY POINTS: • Percutaneous sacroplasty provides pain relief and functional improvement for insufficiency sacral fractures. • Percutaneous sacroplasty provides pain relief and function improvement for sacral tumours. • The major complication rate is acceptable (3.4 %), and is higher in sacral tumours. • Posterior wall/cortical sacral bone disruption is not statistically associated with more complications. • However, osteolytic tumours seem to be associated with higher risk of complications.

Wall mechanics of the stented extracranial carotid artery.

BACKGROUND AND PURPOSE: Abrupt compliance changes and concomitant nonlaminar flow patterns may contribute to endothelial dysfunction and subsequent neointimal thickening. The aim of this study was to test the feasibility of wall mechanics measurement using B-mode ultrasound image analysis by dedicated software in the stented human carotid artery. METHODS: Carotid Wallstents (Schneider) were placed in the extracranial carotid arteries of 15 patients. B-mode ultrasound examination was performed with a 7.5-MHz probe on the carotid artery upstream; at the proximal, mid, and distal stent levels; downstream from the stent; and on the contralateral internal and common carotid arteries. Carotid diameter (d) and systolic diameter changes (Deltad) were measured with a dedicated image processing system (IO version 3.1, IODP), while pulse blood pressure (DeltaP) was measured. Diameter compliance (Cd) and distensibility coefficient (DC) were calculated as Cd=2Deltad/DeltaP and DC=2Deltad/DeltaP/d and compared between measurement sites. RESULTS: The evaluation could be completed in 8 of 15 patients. Compliance was significantly lower at the proximal, mid, and distal stent levels (27.77+/-1.11, 27.38+/-1.08, 27.38+/-1.09x10(-3) mm x kPa(-1)) than upstream (103.3+/-36.7x10(-3) mm x kPa(-1)), downstream (91.5+/-41.3x10(-3) mm x kPa(-1)), or on the contralateral internal (87.6+/-28x10(-3) mm x kPa(-1)) and common (149.3+/-47.6x10(-3) mm x kPa(-1)) carotid arteries. CONCLUSIONS: Stenting of the extracranial carotid artery induces a compliance mismatch between the native and the stented artery.

Rescue balloon procedure for an emergency situation during coil embolization for cerebral aneurysms. Technical note.

In this article the authors describe a rescue balloon procedure for coil implantation in three cases. In each patient, the coil seemed likely to unravel. The coils stretched when attempts were made to remove the partially implanted but trapped device. The inflation of a nondetachable microballoon in front of the aneurysm orifice allowed the surgeons to complete implantation of the coil and to avoid a more forceful and potentially harmful retrieval. This rescue balloon method may be useful for emergency situations, such as coil stretching with or without migration.

Artificial cerebral aneurysm model for medical testing, training, and research.

Artificial models of cerebral aneurysms for medical training and testing of medical devices were constructed from corrosion casts of the main cerebral arteries of a human specimen. Three aneurysms with a variety of shapes were simulated at typical locations. Rigid and soft models were made of silicone using the "lost wax" technique. The transparent silicone models were anatomically accurate and reproducible copies of human vascular casts. These models could be connected in a closed circuit that used an electric pump to simulate pulsatile flow. Endovascular procedures and surgical clip application were performed under fluoroscopic or direct visual control. Surgical clipping, endoluminal coil manipulation, and consecutive hemodynamic changes were visualized by digital subtraction angiography and direct observation. The model provides trainee surgeons with an understanding of clinical conditions. New medical devices, such as platinum coils, would be experimentally implanted in the model under stable conditions. These anatomically accurate and reproducible models of cerebral vasculature and aneurysms are valuable for medical testing, training, and research.

Time course of acute phase in mouse spinal cord injury monitored by ex vivo quantitative MRI.

During the acute phase of spinal cord injury (SCI), major alterations of white and grey matter are a key issue, which determine the neurological outcome. The present study with ex vivo quantitative high-field magnetic resonance microimaging (MRI) was intended in order to identify sensitive parameters of tissue disruption in a well-controlled mouse model of ischemic SCI. MR imaging evidenced changes as early as the second hour after the lesion in the dorsal horns, which appear swollen. After 4 h, alterations of the white matter of dorsal and lateral funiculi were reflected by a progressive loss of white/grey matter contrast with further ventral extension by the 24th hour. Diffusion tensor imaging and multi-exponential T2 measurements permitted to quantify these physicochemical, time-related, alterations during the 24-h period. This characterization of spatial and temporal evolution of SCI will contribute to better define both the most appropriate targets for future therapies and more accurate therapeutic windows. Upcoming directions include the use of these parameters on in vivo animal models and their application to clinics. Indeed, magnetic resonance techniques appear now as a major non-invasive translation tool in CNS pathologies based on the development of more appropriate pre-clinical models.

Percutaneous vertebroplasty for spinal metastases: complications.

PURPOSE: To retrospectively evaluate complications of percutaneous vertebroplasty (PV) performed with polymethylmethacrylate cement to treat pain in patients with metastases to the spine. MATERIALS AND METHODS: This study had institutional review board approval; patient informed consent for the review of records and images was not required. In 2 years, 117 patients (38 men [32.5%] and 79 women [67.5%]; mean age, 58.2 years) underwent 159 fluoroscopy-guided PV procedures to treat 304 vertebrae. Spinal metastases included osteolytic, osteoblastic, and mixed lesions. Complications were characterized as local or systemic. Evaluated data included immediate imaging findings (on radiographs and computed tomographic scans) and clinical findings at 30-day follow-up. Chi2 or Fisher exact testing was performed for univariate analysis of variables. RESULTS: The primary cancers were breast cancers (45.3%), lung cancers (14.5%), myeloma (7.7%), or other cancers (32.5%). Among the 423 cement leakages identified, 332 (78.5%) were vascular and 91 (21.5%) were nonvascular. Vascular leaks were classified as venous epidural leaks, paravertebral and foraminal plexus leaks, and leaks to the vena cava, while nonvascular leaks included puncture trajectory leaks, paravertebral soft tissue leaks, and diskal leaks. Patients with nonvascular leaks were asymptomatic. Eight (6.8%) patients experienced complications, and seven of these complications were symptomatic. Among these eight patients, six (5.1%) had local complications (puncture site hematoma in two patients and radicular pain [successfully treated with nonsteroidal anti-inflammatory drugs or corticosteroids] in four patients), and two (1.7%) had systemic complications (pulmonary embolism resulting from cement migration through the vena cava). One of the latter patients died. Univariate analyses revealed a significant association between cement migration through the vena cava and pulmonary embolism (P = .001) but not between foraminal venous leakage and radicular pain (P = .123). CONCLUSION: Despite numerous technical incidents (leaks), PV-induced complications were rare, leading to the hypothesis that systemic complications are a consequence of intravascular leakage while local complications are a consequence of cement-related irritation, compression and/or ischemia, and/or needle-induced trauma.

Nuclear magnetic resonance microimaging of mouse spinal cord in vivo.

The spinal cord is the site of traumatic injuries, the devastating consequences of which constitute a public health problem in our societies. So far, there is no efficient repair therapeutic approach, and this is mainly due to the great difficulty for elaborating predictive experimental models of this pathology. Up to now, most pathophysiological studies were based on postmortem evaluation of the quantity and extent of the lesions, and their comparison in-between human and rodent specimen. Recent progresses of magnetic resonance imaging provide new tools to examine in vivo rodent central nervous system, and eventually to monitor the progression of lesions. However, up to now, mice spinal cord has been inaccessible to such studies, due to specific physiological characteristics and to the small size of the cord. In this study, the first diffusion-weighted images depicting the mouse thoracic spinal cord in vivo are shown. Motion-related artifacts are significantly reduced by respiratory gating using a dedicated sensor. By changing the direction of diffusion-sensitizing gradients, different contrasts were obtained that are compared with ex vivo MRI and histological preparations. In addition, preliminary results obtained on pathological cords are presented.