Adrian Kastler

Microwave Thermal Ablation of Spinal Metastatic Bone Tumors

PURPOSE To assess feasibility, safety, and efficacy of microwave ablation of spinal metastatic bone tumors. MATERIALS AND METHODS Retrospective study of 17 patients with 20 spinal metastatic tumors treated with microwave ablation under computed tomographic guidance between March 2011 and August 2013 was performed. Ablations were performed under local anesthesia and nitrous oxide ventilation. Lesions were lumbar (n = 10), sacral (n = 7), and thoracic (n = 3) in location. Primary neoplastic sites were lung (n = 9), prostate (n = 4), kidney (n = 6), and uterus (n = 1). Adjunct cementoplasty was performed in nine cases, and a temperature-monitoring device was used in four cases. Procedure effectiveness was evaluated by visual analog scale (VAS) during a 6-month follow-up. Patient medical records were reviewed, and demographic and clinical data, tumor characteristics, and information on pain were assessed. RESULTS Mean ablation time was 4.4 minutes ± 2.7 (range, 1-8 min), with an average of 3.8 cycles per ablation at 60 W (range, 30-70 W). The preprocedure mean VAS score was 7.4 ± 1.2 (range, 6-9). Pain relief was achieved in all but one patient. Follow-up VAS scores were as follows: day 0, 1.3 ± 1.8 (P < .001); day 7, 1.6 ± 1.7 (P < .001); month 1, 1.9 ± 1.6 (P < .001); month 3, 2.2 ± 1.5 (P < .001); and month 6, 2.3 ± 1.4 (P < .01). No complications were noted. CONCLUSIONS Microwave ablation appears to be feasible, safe, and an effective treatment of painful refractory spinal metastases and may be considered as a potential alternative percutaneous technique in the management of spinal metastases.

Diffusion MRI: Pitfalls, literature review and future directions of research in mild traumatic brain injury

Mild traumatic brain injury (mTBI) is a leading cause of disability in adults, many of whom report a distressing combination of physical, emotional and cognitive symptoms, collectively known as post-concussion syndrome, that persist after the injury. Significant developments in magnetic resonance diffusion imaging, involving voxel-based quantitative analysis through the measurement of fractional anisotropy or mean diffusivity, have enhanced our knowledge on the different stages of mTBI pathophysiology. Other diffusion imaging-derived techniques, including diffusion kurtosis imaging with multi-shell diffusion and high-order tractography models, have recently demonstrated their usefulness in mTBI. Our review starts by briefly outlining the physical basis of diffusion tensor imaging including the pitfalls for use in brain trauma, before discussing findings from diagnostic trials testing its usefulness in assessing brain structural changes in patients with mTBI. Use of different post-processing techniques for the diffusion imaging data, identified the corpus callosum as the most frequently injured structure in mTBI, particularly at sub-acute and chronic stages, and a crucial location for evaluating functional outcome. However, structural changes appear too subtle for identification using traditional diffusion biomarkers, thus disallowing expansion of these techniques into clinical practice. In this regard, more advanced diffusion techniques are promising in the assessment of this complex disease.

Analgesic Effects of Microwave Ablation of Bone and Soft Tissue Tumors Under Local Anesthesia

OBJECTIVE To assess the feasibility and efficacy of microwave ablation (MWA) of painful refractory bone and soft tissue tumors performed under local anesthesia. STUDY DESIGN A retrospective study between 2011 and 2013. SETTING A single center, Academic Interventional Pain Management Unit. SUBJECTS Fifteen patients with 25 refractory painful bone (N = 19) or soft tissue (N = 6) tumors treated with MWA were consecutively included. METHOD Local Institutional Review Board approval was obtained, and written informed consent was waived. Lesions included spinal (N = 3), sacral (N = 4), and extraspinal (N = 18) locations. Pain was measured on a visual analog scale (VAS) from 0 to 10 before and immediately after procedure, at 1 week, and on a monthly basis following procedure. MWA procedures were always performed under computed tomography guidance and local anesthesia along with nitrous oxide inhalation. RESULTS Mean ablation time was 4.09 minutes (range 1-11) with an average of 4.2 cycles with a mean ablation power of 60 W. Preprocedure mean VAS score was 7.2 ± 0.97 (range 6-9). Follow-up postprocedure VAS scores were as follows: day 0: 1.64 ± 1.86, day 7: 1.82 ± 1.79, month 1: 2.05 ± 2.03 (14/15 patients), month 3: 2.13 ± 1.81, month 6: 2.36 ± 2.17; and were statistically significant (P < 0.001). Mean pain relief was 5.5 months. CONCLUSION MWA is feasible, safe, and effective in the management of painful refractory bone and soft tissue tumors. It may therefore be considered as a potential alternative to existing percutaneous ablation techniques in the management of bone and soft tissue tumors.

Preoperative imaging in the planning of deep inferior epigastric artery perforator flap surgery

Breast reconstruction with adipocutaneous free flap from the abdominal wall combines the benefits of abdominoplasty to those of a prosthesis-free breast reconstruction. The deep inferior epigastric artery perforator (DIEP) flap is supplied by intramuscular perforators from the deep inferior epigastric artery (DIEA). It consists of the dissection of perforating branches of the DIEA within the rectus abdominis muscle, thus sparing both muscle and fascia. Preoperative imaging in the planning of DIEP flap surgery has been shown to facilitate faster and safer surgery. This review article aims to discuss advantages and drawbacks of current imaging modalities for mapping the course of perforating vessels in the planning of DIEP flap surgery, and to present state-of-the-art imaging techniques.

Percutaneous vertebroplasty under local anaesthesia: feasibility regarding patients’ experience

ObjectiveEvaluate patients’ intraoperative experience of percutaneous vertebroplasty (PV) performed without general anaesthesia in order to assess the feasibility of local anaesthesia and simple analgesic medication as pain control protocol.MethodsNinety-five patients who underwent single-site PV were consecutively included in the study between 2011 and 2013. Each procedure was achieved under local anaesthesia and perfusion of paracetamol, tramadol and dolasetron, with combined CT and fluoroscopy guidance. Numeric pain scale (NPS) was collected before, during and after intervention. After intervention, patients were asked to evaluate their experience as “very bad”, “bad”, “fair”, “good” or “very good”, independently of the pain.ResultsIndications for vertebroplasty were osteopenic fractures (78 %), aggressive angiomas (13 %) and somatic tumours (9 %). In 76 % of cases, patients’ experience was described as “very good” (44 %) or “good” (32 %), whereas 19 % described it as “fair” and 5 % as “very bad”. Mean operative NPS was 5.5. After intervention, NPS was significantly lower with a decrease of 4.5 points. No differences were found according to the localization, type of lesion, age or sex either in terms of experience or NPS.ConclusionPercutaneous vertebroplasty is feasible under local anaesthesia alone, with a very good or good experience in 76 % of the patients.Key Points• Vertebroplasty is a first-line therapy for consolidation and pain control of vertebral lesions.• This procedure is commonly performed under general anaesthesia or conscious sedation.• We perform vertebroplasty under local anaesthesia and simple analgesic protocol with acceptable experience.• Percutaneous vertebroplasty can safely be proposed in a fragile population.

Post traumatic deafness: a pictorial review of CT and MRI findings

AbstractHearing loss is a common functional disorder after trauma, and radiologists should be aware of the ossicular, labyrinthine or brain lesions that may be responsible. After a trauma, use of a systematic approach to explore the main functional components of auditory pathways is essential. Conductive hearing loss is caused by the disruption of the conductive chain, which may be due to ossicular luxation or fracture. This pictorial review firstly describes the normal 2-D and 3-D anatomy of the ossicular chain, including the incudo-malleolar and incudo-stapedial joints. The role of 3-D CT in the post-traumatic evaluation of injury to the temporal bone is then evaluated. In the case of sensorineural hearing loss, CT can detect pneumolabyrinth and signs of perilymphatic fistulae but fails to detect subtle lesions within the inner ear, such as labyrinthine haemorrhage or localized brain axonal damage along central auditory pathways. The role that MRI with 3-D-FLAIR acquisition plays in the detection of inner ear haemorrhage and post-traumatic lesions of the brain parenchyma that may lead to auditory agnosia is also discussed.Key Points• The most common middle ear injuries are incudo-malleolar and incudo-stapedial joint luxation. • In patients with SNHL, CT can detect pneumolabyrinth or perilymphatic fistula • 3-D-FLAIR MRI appears the best sequence to highlight labyrinthine haemorrhage • Axonal damage and brain hematoma may lead to deafness

Diffusion MRI: literature review in salivary gland tumors

Surgical resection is currently the best treatment for salivary gland tumors. A reliable magnetic resonance imaging mapping, encompassing tumor grade, location, and extension may assist safe and effective tumor resection and provide better information for patients regarding potential risks and morbidity after surgical intervention. However, direct examination of the tumor grade and extension using conventional morphological MRI remains difficult, often requiring contrast media injection and complex algorithms on perfusion imaging to estimate the degree of malignancy. In addition, contrast-enhanced MRI technique may be problematic due to the recently demonstrated gadolinium accumulation in the dentate nucleus of the cerebellum. Significant developments in magnetic resonance diffusion imaging, involving voxel-based quantitative analysis through the measurement of the apparent diffusion coefficient, have enhanced our knowledge on the different histopathological salivary tumor grades. Other diffusion imaging-derived techniques, including high-order tractography models, have recently demonstrated their usefulness in assessing the facial nerve location in parotid tumor context. All of these imaging techniques do not require contrast media injection. Our review starts by outlining the physical basis of diffusion imaging, before discussing findings from diagnostic studies testing its usefulness in assessing salivary glands tumors with diffusion MRI.

Radiofrequency Neurolysis in the Management of Inguinal Neuralgia: Preliminary Study

PURPOSE To evaluate the feasibility and efficacy of computed tomography (CT)-guided radiofrequency (RF) neurolysis (RFN) in the management of refractory inguinal neuralgia. MATERIALS AND METHODS Local institutional review board approval was obtained and written informed consent was waived. Twelve patients 26-75 years of age with chronic (>6 months) inguinal pain refractory to specific medication were included between 2005 and 2011. Data on patient demographics, clinical history, and pain management history were retrospectively assessed. Pain was measured on a visual analog scale (VAS) from 0 to 10 before and immediately after the procedure and at 1, 3, 6, 9 and 12 months. Diagnosis was always confirmed by a positive nerve block test result. Ambulatory CT-guided RF was the rule. RESULTS Sixteen RFN procedures were performed. Pain was present for an average of 3.2 years (range: 2-8 years) prior to initial RFN. Mean VAS score before the procedure was 7.75 of 10. Immediate pain relief of 100% was achieved in all patients. Pain reduction at 1-, 3-, 6-, 9-, and 12-month follow-up was statistically significant. Important pain reduction (≥80%) was obtained in 75% of RFN procedures at 6-month follow-up and in 50% of cases at 12 months. The mean duration of pain relief was 11.8 months after RFN, with a maximum average pain reduction of 84.5%. No complications were noted during or after the procedure. CONCLUSION RFN with CT guidance is an effective technique in the management of refractory inguinal pain with lasting satisfactory pain reduction; it may be considered as an alternative treatment to surgery. These results should be confirmed in a controlled trial with a larger series of patients.

Arterial Injury Complicating Subclavian Central Venous Catheter Insertion

n i a a g n c INADEQUATE PLACEMENT of a subclavian venous catheter in the subclavian artery is a well-known complication.1,2 Three cases of accidental arterial puncture occurred with the implantation of subclavian venous catheters, 2 of which involved the subclavian artery leading to percutaneous treatment; and the other involved the aortic arch, resulting in surgical management, are described.

Interest of local intra-arterial fibrinolysis in acute central retinal artery occlusion: Clinical experience in 16 patients

OBJECTIVE Central retinal artery occlusion (CRAO) is a rare disease with poor visual prognosis. We evaluated clinical effectiveness of in situ fibrinolysis with original angiographic scores describing the aspect of carotid siphon, proximal ophthalmic artery, and choroid blush. METHODS Retrospective study of 16 consecutive cases of CRAO between 2007 and 2013. Fourteen underwent in situ fibrinolysis, two were excluded due to pre-occlusive internal carotid stenosis on pre-procedural diagnostic angio-CT. Fibrinolysis was performed with rt-PA (average injected dose: 35 mg), with an average onset delay of 8hours (4-17h). We reported angiographic scores pre- and post-fibrinolysis, visual acuity (VA) before and after treatment, and VA improvement evaluated by ophthalmologist 6 to 12 months after thrombolysis. RESULTS Six patients (43%) recovered post-fibrinolysis VA significally improved, superior or equal to 1/10 (1/10 to 8/10). An irregular carotid siphon (2 cases) appeared as a predictive factor of failure. Fibrinolysis procedure led to a significant improvement of angiographic permeability of proximal ophthalmic artery (P=0.0498), but this result was not accompanied by any VA improvement. The aspect of choroid blush showed no correlation with the management of thrombolysis. CONCLUSION In situ fibrinolysis was more effective than medical treatments or natural evolution of CRAO (VA improvement was respectively 40% and 20%). However, the benefit/risk ratio must be discussed, and an angio-CT of supra-aortic trunks could be systematically performed before thrombolysis, to assess the potential VA recovery compared with complications such as ischemic stroke.