Percutaneous femoral access: Stuck guide wire, decannulation difficulty due to unravelling and knotting.

Percutaneous techniques for femoral arterial access are increasingly being performed due to advances in endovascular cerebral procedures, as they provide a less morbid and minimally invasive approach than open procedures. Common complications associated with this peripheral puncture include hematoma, bleeding, pseudoaneurysm, arteriovenous fistula, retroperitoneal bleeding, inadvertent venous puncture, dissection, etc. The retrograde femoral access is currently the most frequently used arterial access as it is technically straightforward, allows for the use of larger size sheaths and catheters, allows repeated attempts, etc. Although being technically less challenging, grave complications can occur due to hardware failure. Here, we present a case of unruptured posterior inferior cerebellar artery (PICA) aneurysm, who underwent uneventful diagnostic cerebral digital substraction angiography (DSA) via right femoral artery route on first attempt, but on second attempt for therapeutic intervention, landed up with stuck guide wire and faced decannulation difficulty due to unravelling of guide wire and multiple knot formation, which was finally removed after multiple attempts at pulling and improvised manoeuvres. Such cannulation and decannulation difficulties have been reported multiple times for central venous access, but extremely rarely for femoral routes, making this case a rarity and worth reporting.

Fluorescence Assisted Stereotactic Biopsy of Contrast-Enhancing Brain Lesions: Can YELLOW 560-nm Filter Substitute Frozen Section?

BACKGROUND: The factors on which the accuracy of stereotactic brain biopsy depends are the competence of the neurosurgeon in obtaining a representative sample and the ability of the neuropathologist to make a histological diagnosis from a minuscule sample. Over the years intraoperative frozen section has enhanced the diagnostic yield of this minimally invasive procedure. Use of fluorescence in achieving a greater extent of resection is well-established in contemporary neurosurgical practice. This ability of brain tumors to take up the fluorescein sodium dye and glow under the YELLOW 560-nm filter has been utilized in a handful of studies to increase the diagnostic accuracy of stereotactic biopsy. METHODS: We performed a prospective study where the fluorescein sodium dye was injected at a low dose and fluorescence of the biopsied core was compared with that of a tissue obtained from the normal parenchyma. Sample was labeled 'truly fluorescent' only when the glow was more than that of the tissue from normal parenchyma. RESULTS: On cross-tabulating the index test (true fluorescence status) and the reference standard test (final histopathological report) the sensitivity of acquiring a representative sample was found to be 94.74%, specificity was 100%. The positive predictive value and negative predictive value were calculated to be 100% and 50% respectively. The diagnostic yield was comparable to that of the intraoperative frozen section. CONCLUSION: The use of the YELLOW 560-nm filter can make stereotactic biopsy faster, safer, less cumbersome, and more cost-effective, and can be used as a substitute for the frozen section in resource-constrained centers.

Pentagon Inside the Circle of Willis and the Golden Ratio.

The Golden ratio ("phi" or "Ф") has been known to us for ages and its use in art and architectural designs has enhanced its exquisiteness. Even some of the astounding creations of nature do follow this principle of Golden or divine proportions. Three centuries ago the circle of Willis at the base of the brain was first described and illustrated by Thomas Willis. Classically it was described as being circular in shape, however, the gross anatomy reveals a slightly different picture. The components of this complex neurovascular structure are so arranged that it appears more like a pentagon than a circle. A regular pentagon, unlike a circle, is a Golden shape that mathematically obeys the laws of Golden proportions. Like most other marvelous structures in nature, the close resemblance of the circle of Willis to a pentagon is more of a conscious effort of nature to establish consonance with aesthetic perception, rather than just a mere coincidence.