1. Cauley KA. Fluoroscopically Guided Lumbar Puncture. Am J Roentgenol. 2015;205(4):W442–W450. doi:10.2214/AJR.14.14028.
This is an excellent and comprehensive review of the mechanics, indications, contraindications of performing LP’s and myelograms. The review also tackles the complex and ever changing topic of when to do an LP in the face of some type of anticoagulation. The author notes that many institutions use the minimal platelet value of 50,000, and an INR of less than 1.5.
My personal set of rules for myelography:
- Platelets of 50K, INR <1.5. For me, aspirin by itself is not a contraindication to LP.
- Check available imaging, both brain and spine. No intracranial masses which might cause brain shift / herniation if the pressure is lowered by the LP/myelogram. Gauge the difficulty of the stick and the most open level if pre-procedure lumbar imaging is available.
- Always know what you are injecting. You check the label personally on the bottle. I dislike coming into a room and having the syringes pre-filled. That is a setup for trouble. Take the 30 seconds and draw up the contrast and lidocaine yourself.
- Nobody goes to ground. Having your patient fall of the myelography table is considered poor form. If someone is being tilted head down for a myelogram, someone should be in a dedicated position at the head of the table to reassure the patient, and to watch for any slipping off the table.
- Don’t inject a normal volume of contrast below a spinal block. Not only does this cause the patient pain, but also there is the theoretical risk of increasing the intrathecal pressure above venous (and even arterial) pressure that would cause cord ischemia. The bigger picture here is to understand the myelographic technique for running the spine for a block. The typical scenario is the emergency room patient with a pacemaker, who needs a myelogram to exclude cord/conus compression. These patients should be done with a tilt table C-arm. If you are doing myelograms with a GI table, then you should make friends with the endoscopists. They will have a C-arm, and may have a table that can tilt down the few degrees necessary for this procedure. I prefer these cases to be done in a lateral decubitus position, which straightens out the thoracic kyphosis and allow the contrast to be maneuvered from the lumbar spine to the cervical spine with a minimal amount of table tilt. Perform the lumbar puncture using cross table fluoro in the decubitus position. Instill 3-5 cc of contrast and make sure the contrast falls to the dependent position within the thecal sac, and away from the needle tip. The needle stays in place. Keeping the fluoro in the cross table direction, tilt the patient head down and watch the contrast move in the gutter of the dependent part of the thecal sac towards the cervical spine. Once that thin line of contrast has gone up to the foramen magnum, you have cleared the spine of a complete block. You can now return the table to the neutral position, and instill the rest of the contrast for the myelogram and subsequent CT. In the modern era with MR screening of these patients for cord compression, we have less experience with the myelographic equivalent of screening and clearing the spine. It is an important technique to have in your armamentarium.
2. Yang C, Bogiatzi C, Spence JD. Risk of Stroke at the Time of Carotid Occlusion. JAMA Neurol. 2015;72(11):1. doi:10.1001/jamaneurol.2015.1843.
The authors performed a retrospective analysis of data from 2 stroke prevention clinics from 1990-2012, to determine the risk resulting from progression to occlusion among patients with asymptomatic carotid stenosis. Most of the new occlusions (80.4%) occurred before 2002, when medical therapy was less intensive. One patient (0.3%) had a stroke at the time of the occlusion, and 3 patients (0.9%) had an ipsilateral stroke during follow-up (all before 2005). Regression analyses showed that only age, sex, and carotid plaque burden significantly predicted risk of those events. They conclude that the risk of progression to occlusion is below the risk of carotid stenting or endarterectomy and has decreased markedly with more intensive medical therapy and that preventing carotid occlusion may not be a valid indication for stenting.
3. Chaturvedi S, Sacco RL. Are the Current Risks of Asymptomatic Carotid Stenosis Exaggerated ? Further Evidence Supporting the CREST 2 Trial. JAMA Neurol. 2015;72(11):1233–1234. doi:10.1001/jamaneurol.2015.2196
This is the editorial accompanying the Yang et al paper. The author notes that carotid artery stenting and carotid endarterectomy are commonly performed in asymptomatic patients. Among Medicare patients from 2004-2006, 87% of carotid artery stenting and 88% of carotid endarterectomy procedures were performed in asymptomatic patients. Are current medial therapies sufficient to reduce the rationale for CEA or CAS? The NINDS has funded the CREST 2 trial, which will have two studies: comparing carotid endarterectomy and aggressive medical management vs. aggressive medical management alone and the other comparing carotid artery stenting and aggressive medical management vs. aggressive medical management alone.
Check out the ClinicalTrials.gov website for this: https://clinicaltrials.gov/ct2/show/NCT02089217
4. Evaniew N, Files C, Smith C, et al. The fragility of statistically significant findings from randomized trials in spine surgery: a systematic survey. Spine J. 2015;15(10):2188–2197. doi:10.1016/j.spinee.2015.06.004.
I found this study fascinating: The authors set out to determine the robustness of statistically significant results from randomized controlled trials (RCT) using a systematic survey technique. The outcome measure was the Fragility Index, which is the minimum number of patients in a trial whose status would have to change from a nonevent to an event to change a statistically significant result to a nonsignificant result. They identified 40 eligible RCTs with a median sample size of 132 patients. Now the stunning statistic: The median Fragility Index was two, which means that adding two events to one of the trial’s treatment arms eliminated its statistical significance. The Fragility Index was less than or equal to three events in 75% of the trials. They conclude that the statistical significance of results from RCTs in spine surgery is frequently fragile because of relatively small sample sizes with few outcome events.
5. Familiari P, Maldaner N, Kursumovic A, et al. Cost Comparison of Surgical and Endovascular Treatment of Unruptured Giant Intracranial Aneurysms. Neurosurgery. 2015;77(5):1. doi:10.1227/NEU.0000000000000917.
The authors retrospectively examined 55 patients with unruptured GIAs treated surgically (37 patients) or endovascularly (18 patients) between April 2004 and March 2014. They found no difference in the costs of hospital stay between surgical and endovascular treatment groups ($10,565 vs. $14,992). Imaging costs were significantly higher in the surgical group than in the endovascular treatment group ($2,890 vs. $1,612). Costs of the intervention room and personnel involved in the intervention were significantly higher in the surgical group than in the endovascular treatment group ($5,566 vs $1,520). Implants used per patient were more expensive in the endovascular group than in the surgical treatment group ($20,885 vs $167). Endovascular GIA treatment produced higher direct costs than surgical GIA treatment ($52,325 vs $20,619) mainly due to higher implant costs.
Not really surprising, but good to have the actual numbers.
6. Flores A, Rubiera M, Ribó M, et al. Poor Collateral Circulation Assessed by Multiphase Computed Tomographic Angiography Predicts Malignant Middle Cerebral Artery Evolution After Reperfusion Therapies. Stroke. 2015;46(11):3149–3153. doi:10.1161/STROKEAHA.115.010608.
The authors evaluated the impact of collateral circulation (CC) using multiphase computed tomographic angiography during the acute stroke phase in the prediction of malignant middle cerebral artery infarction (mMCAi). 82 consecutive acute stroke patients (<4.5 hours) who were evaluated for reperfusion therapies and presented with an M1-MCA or terminal internal carotid artery occlusion by CTA were included. Collateral circulation was evaluated on 6 grades by multiphase CTA according to the University of Calgary CC Scale. Fifteen patients developed mMCAi, and patients with mMCAi had lower collateral circulation scores (2.29 versus 3.71). Patients with poor collateral circulation had higher risk of developing mMCAi (13% versus 2%). They conclude that collateral circulation assessment by multiphase CTA independently predicts malignant MCA infarction progression.
Do we need to change our current stroke CTA protocol to include the additional phases required for this technique? Yep.
See also: Menon BK, D’Esterre CD, Qazi EM, et al. Multiphase CT Angiography: A New Tool for the Imaging Triage of Patients with Acute Ischemic Stroke. Radiology. 2015;275(2):510–520. doi:10.1148/radiol.15142256.
7. Huang D-G, Hao D-J, He B-R, et al. Posterior atlantoaxial fixation: a review of all techniques. Spine J. 2015;15(10):2271–2281. doi:10.1016/j.spinee.2015.07.008.
Comprehensive review of posterior cervical spinal fixation techniques, including 19 figures. The authors note that wiring techniques and interlaminar clamps technique have fallen out of favor because of the development of superior fixation techniques. The C1–C2 transarticular screw technique remains the gold standard for atlantoaxial fusion, whereas screw-rod systems, especially the C1 pedicle screw combined with C2 pedicle/pars screw fixation, have become the most popular fixation techniques.
8. Mirzaei L, Kaal SEJ, Schreuder HWB, Bartels RHMA. The Neurological Compromised Spine Due to Ewing Sarcoma. What First: Surgery or Chemotherapy? Therapy, Survival, and Neurological outcome of 15 cases with primary Ewing Sarcoma of the Vertebral Column. Neurosurgery. 2015;77(5):718–725. doi:10.1227/NEU.0000000000000903.
The authors present their retrospective study examining a group of 15 patients with primary spinal Ewing sarcoma and high-grade cord or cauda equina compression. Eleven patients were treated with upfront chemotherapy and 4 patients were treated with surgery. There was no difference in neurological outcomes between the 2 groups and both groups experienced excellent neurological recovery. They conclude that adequate and quick decompression of neural structures with similar results can be achieved by chemotherapy and radiotherapy, avoiding the local spill of malignant cells which might occur with surgery. Ewing sarcoma within the spine with compression of the spinal cord should not be considered as a distinct entity and can be managed in a way that has proven to be the best for those located in other parts of the body.
