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Journal: Operative neurosurgery (Hagerstown, Md.)


Cerebrospinal fluid (CSF) drainage is important in retrosigmoid approached surgery; however, in some cases, it is not feasible due to cerebellar swelling.

Concepts: Instrument approach, Cerebrospinal fluid, Lumbar puncture, Fissure, Horizontal fissure of right lung


Deep brain stimulation (DBS) is well-established, evidence-based therapy for Parkinson disease, essential tremor, and primary dystonia. Clinical outcome studies have recently shown that “asleep” DBS lead placement, performed using intraoperative imaging with stereotactic accuracy as the surgical endpoint, has motor outcomes comparable to traditional “awake” DBS using microelectrode recording (MER), but with shorter case times and improved speech fluency.


External ventricular drain (EVD) placement is the most frequently performed neurosurgical procedure for management of various conditions including hydrocephalus, traumatic brain injury, and stroke. State-of-the-art computational pattern recognition techniques could improve the safety and accuracy of EVD placement. Placement of the Kocher’s point EVD is the most common neurosurgical procedure which is often performed in urgent conditions.


In this 3-dimensional video, we perform a side-to-side and end-to-side double anastomosis using the parietal-branch of the superficial temporal artery (STA) to provide flow augmentation in a symptomatic 59-yr-old male with bilateral internal carotid artery occlusion at the origin, and left M1 segment occlusion. The patient suffered multiple left hemispheric strokes despite maximal medical therapy and was found to have poor hemodynamic reserve in the left hemisphere during evaluation with regional and global blood oxygenation level-dependent functional magnetic resonance imaging with CO2-challenge as well as quantitative magnetic resonance angiography and noninvasive optimal vessel analysis pre- and post-acetazolamide challenge. Postoperatively, the patient did very well and his hemodynamic studies improved significantly. The importance of this technique relies on the fact that we are using a single donor vessel to perform 2 anastomoses, and carries the following advantages: (1) the frontal STA branch remains intact and therefore can still be used at a later time if further revascularization is needed; (2) wound complications related to devascularizing the scalp from harvesting both STA branches are reduced; (3) 2 vascular territories are augmented (frontal and temporal) while using a single donor; (4) we are maximizing donor potential and optimizing cut flow index (CFI; total bypass flow postanastomosis divided by bypass cut flow) by flow augmenting 2 separate vascular beds therefore increasing demand. To explain that fourth point further: if the STA donor is able to carry a maximum 100 mL/min when cut, and after performing the first anastomosis bypass flow is only 37 mL/min, CFI will be 37/100 = 0.37, reflecting low demand, a poor indicator of graft patency, as previously published.1,2 By adding a second anastomosis which demands an additional 60 mL/min from the same STA donor, CFI (60 + 37)/100 improves to 1. Institutional Review Board approval was obtained for the review of patient chart and video files. Informed consent was obtained directly from the patient via telephone regarding use of media for educational and publication purposes.

Concepts: Medical imaging, Magnetic resonance imaging, Common carotid artery, External carotid artery, Arteries of the head and neck, Scalp, Temple, Superficial temporal artery


Pseudarthrosis after anterior cervical discectomy and fusion (ACDF) causes persistent pain and related disability. Posterior revision surgery results in higher healing rates, but is more extensive compared to anterior surgery.

Concepts: Anterior cervical discectomy and fusion, Discectomy, Neurosurgery


Measurement of optic nerve sheath diameter (ONSD) is a promising technique for noninvasive assessment of intracranial pressure (ICP), but has certain limitations. A recent study showed that the deformability index (DI), a dynamic parameter quantifying the pulsatile nature of the optic nerve sheath, could differentiate between patients with high vs normal ICP.


Intraventricular access is frequently required during neurosurgery, and when neuronavigation is unavailable, the neurosurgeon must rely upon craniometrics to achieve successful ventricular cannulation. In this historical review, we summarize the most well-described ventricular access points: Kocher’s, Kaufman’s, Paine’s, Menovksy’s, Tubbs', Keen’s, Frazier’s, Dandy’s, and Sanchez’s. Additionally, we provide multiview, 3-dimensional illustrations that provide the reader with a novel understanding of the craniometrics associated with each point.


The innate detail of the cerebrovasculature is a demonstration of the structural complexity exhibited within the nervous system and highlights the challenges intrinsic to surgically influencing this system. Bridging the knowledge gap between the 2-dimentional learning environment and the 3-dimensional (3D) clinical setting is a challenge requiring experience. Computer graphic technology provides an opportunity for the learner to step into a new era of learning via the use of interactive 3D models and virtual reality.


Limited data exist pertaining to outcomes following surgery for recurrent Rathke’s cleft cysts (RCC).


Clip occlusion of previously coiled aneurysms poses unique technical challenges. The coil mass can complicate aneurysm neck access and clip tine approximation. This patient had a previously ruptured anterior communicating artery (ACOM) aneurysm that had been treated with coil embolization. On follow-up evaluation, the patient was found to have a recurrence of the aneurysm, which prompted an orbitozygomatic craniotomy for clip occlusion. The approach provided a favorable view of the aneurysm neck with the coil mass protruding outside the aneurysm dome. Indocyanine green fluoroscopy was used to assist with ideal permanent clip placement along the aneurysm neck. The segment of coils present outside the aneurysm neck was removed to reduce mass effect on the optic chiasm. Postoperative imaging demonstrated aneurysm obliteration. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.