4K resolution

4K resolution, also called 4K, refers to a horizontal screen display resolution in the order of 4,000 pixels

There are several different 4K resolutions in the fields of digital television and digital cinematography. In television and consumer media, 3840 × 2160 (4K UHD) is the dominant 4K standard. In the movie projection industry, 4096 × 2160 (DCI 4K) is the dominant 4K standard.

The 4K television market share increased as prices fell dramatically during 2014 and 2015. By 2020, more than half of U.S. households are expected to have 4K-capable TVs, which would be a much faster adoption rate than that of Full HD (1080p).


A 4K 3D video microscope is compact, and provides high-resolution images, contributing larger surgical space and facilitating a multi-team surgery1).


Advances in video and fiber optics since the 1990s have led to the development of several commercially available high-definition neuroendoscopes. This technological improvement, however, has been surpassed by the smartphone revolution. With the increasing integration of smartphone technology into medical care, the introduction of these high-quality computerized communication devices with built-in digital cameras offers new possibilities in neuroendoscopy. The aim of a study of Mandel et al., was to investigate the usefulness of smartphone-endoscope integration in performing different types of minimally invasive neurosurgery.

They presented a new surgical tool that integrates a smartphone with an endoscope by use of a specially designed adapter, thus eliminating the need for the video system customarily used for endoscopy. They used this novel combined system to perform minimally invasive surgery on patients with various neuropathological disorders, including cavernomas, cerebral aneurysms, hydrocephalussubdural hematomas, contusional hematomas, and spontaneous intracerebral hematomas.

The new endoscopic system featuring smartphone-endoscope integration was used by the authors in the minimally invasive surgical treatment of 42 patients. All procedures were successfully performed, and no complications related to the use of the new method were observed. The quality of the images obtained with the smartphone was high enough to provide adequate information to the neurosurgeons, as smartphone cameras can record images in high definition or 4K resolution. Moreover, because the smartphone screen moves along with the endoscope, surgical mobility was enhanced with the use of this method, facilitating more intuitive use. In fact, this increased mobility was identified as the greatest benefit of the use of the smartphone-endoscope system compared with the use of the neuroendoscope with the standard video set.

Minimally invasive approaches are the new frontier in neurosurgery, and technological innovation and integration are crucial to ongoing progress in the application of these techniques. The use of smartphones with endoscopes is a safe and efficient new method of performing endoscope-assisted neurosurgery that may increase surgeon mobility and reduce equipment cost2).


Three commercially available cameras were tested: GoPro Hero 4 Silver, Google Glass, and Panasonic HX-A100 action camera. Typical spine surgery was selected for video recording; posterior lumbar laminectomy and fusion. Three cameras were used by one surgeon and video was recorded throughout the operation. The comparison was made on the perspective of human factor, specification, and video quality.

The most convenient and lightweight device for wearing and holding throughout the long operation time was Google Glass. The image quality; all devices except Google Glass supported HD format and GoPro has unique 2.7K or 4K resolution. Quality of video resolution was best in GoPro. Field of view, GoPro can adjust point of interest, field of view according to the surgery. Narrow FOV option was the best for recording in GoPro to share the video clip. Google Glass has potentials by using application programs. Connectivity such as Wi-Fi and Bluetooth enables video streaming for audience, but only Google Glass has two-way communication feature in device.

Action cameras have the potential to improve patient safety, operator comfort, and procedure efficiency in the field of spinal surgery and broadcasting a surgery with development of the device and applied program in the future 3).


Patients were operated on through transnasal transsphenoidal endoscopic approaches performed using Olympus NBI 4K UHD endoscope with a 4 mm 0° Ultra Telescope, 300 W xenon lamp (CLV-S400) predisposed for narrow band imaging (NBI) technology connected through a camera head to a high-quality control unit (OTV-S400 – VISERA 4K UHD) (Olympus Corporation, Tokyo, Japan). Two screens are used, one 31“ Monitor – (LMD-X310S) and one main ultra-HD 55” screen optimised for UHD image reproduction (LMD-X550S). In selected cases, we used a navigation system (Stealthstation S7, Medtronic, Minneapolis, MN, US).

Rigante et al., evaluated 22 pituitary adenomas (86.3% macroadenomas; 13.7% microadenomas). 50% were not functional (NF), 22.8% GH, 18.2% ACTH, 9% PRL-secreting. Three of 22 were recurrences. In 91% of cases we achieved total removal, while in 9% near total resection. A mean follow-up of 187 days and average length of hospitalisation was 3.09 ± 0.61 days. Surgical duration was 128.18± 30.74 minutes. We experienced only 1 case of intraoperative low flow fistula with no further complications. None of the cases required any post- or intraoperative blood transfusion. The visualisation and high resolution of the operative field provided a very detailed view of all anatomical structures and pathologies allowing an improvement in safety and efficacy of the surgical procedure. The operative time was similar to the standard 2D HD and 3D procedures and the physical strain was also comparable to others in terms of ergonomics and weight 4).

References

1)

Yoshida K, Toda M, Akiyama T, Takahashi S, Nishimoto M, Ozawa H, Ikari Y, Yoshida K. Combined Endoscopic Endonasal and Video-microscopic Transcranial Approach with Preoperative Embolization for a Posterior Pituitary Tumor. World Neurosurg. 2018 Nov;119:201-208. doi: 10.1016/j.wneu.2018.07.245. Epub 2018 Aug 6. PubMed PMID: 30092469.
2)

Mandel M, Petito CE, Tutihashi R, Paiva W, Abramovicz Mandel S, Gomes Pinto FC, Ferreira de Andrade A, Teixeira MJ, Figueiredo EG. Smartphone-assisted minimally invasive neurosurgery. J Neurosurg. 2018 Mar 1:1-9. doi: 10.3171/2017.6.JNS1712. [Epub ahead of print] PubMed PMID: 29529913.
3)

Lee CK, Kim Y, Lee N, Kim B, Kim D, Yi S. Feasibility Study of Utilization of Action Camera, GoPro Hero 4, Google Glass, and Panasonic HX-A100 in Spine Surgery. Spine (Phila Pa 1976). 2017 Feb 15;42(4):275-280. doi: 10.1097/BRS.0000000000001719. PubMed PMID: 28207670.
4)

Rigante M, La Rocca G, Lauretti L, D’Alessandris GQ, Mangiola A, Anile C, Olivi A, Paludetti G. Preliminary experience with 4K ultra-high definition endoscope: analysis of pros and cons in skull base surgery. Acta Otorhinolaryngol Ital. 2017 Jun;37(3):237-241. doi: 10.14639/0392-100X-1684. PubMed PMID: 28516968; PubMed Central PMCID: PMC5463515.

MATLAB

MATLAB is a multi-paradigm numerical computing environment and proprietary programming language developed by MathWorks.


Miller et al., from the Department of Neurosurgery of Stanford and Kaiser Permanente Redwood City Medical Center, proposed and presented a novel stereotactic coordinate system based on mesial temporal anatomical landmarks to facilitate the planning and delineation of outcomes based on extent of ablation or region of stimulation within mesial temporal structures.

The body of the hippocampus contains a natural axis, approximated by the interface of cornu ammonis (CA4) and the dentate gyrus. The uncal recess of the lateral ventricle acts as a landmark to characterize the anterior-posterior extent of this axis. Several volumetric rotations are quantified for alignment with the mesial temporal coordinate system. First, the brain volume is rotated to align with standard anterior commissureposterior commissure (AC-PC) space. Then, it is rotated through the axial and sagittal angles that the hippocampal axis makes with the AC-PC line.

Using this coordinate system, customized MATLAB software was developed to allow for intuitive standardization of targeting and interpretation. The angle between the AC-PC line and the hippocampal axis was found to be approximately 20°-30° when viewed sagittally and approximately 5°-10° when viewed axially. Implanted electrodes can then be identified from CT in this space, and laser tip position and burn geometry can be calculated based on the intraoperative and postoperative MRI.

With the advent of stereotactic surgery for mesial temporal targets, a mesial temporal stereotactic system is introduced that may facilitate operative planning, improve surgical outcomes, and standardize outcome assessment 1).


Using an administrative database and chart review, Ramayya et al., identified 101 first-time external ventricular drain placements performed at the bedside. They collected data regarding demographics, medical comorbidities, complications, and catheter tip location. They performed univariate and multivariate statistical analysis using MATLAB. They corrected for multiple comparisons using the false discovery rate (FDR) procedure.

Multivariate regression analyses revealed that revision procedures were more likely to occur after drain blockage (odds ratio [OR] 17.9) and hemorrhage (OR 10.3, FDR-corrected P values < 0.01, 0.05, respectively). Drain blockage was less frequent after placement in an “optimal location” (ipsilateral ventricle or near foramen of Monroe; OR 0.09, P = 0.009, FDR-corrected P < 0.03) but was more likely to occur after placement in third ventricle (post-hoc P values < 0.015). Primary diagnoses included subarachnoid hemorrhage (n = 30, 29.7%), intraparenchymal hemorrhage with intraventricular extravasation (n = 24, 23.7%), tumor (n = 20, 19.8%), and trauma (n = 17, 16.8%). Most common complications included drain blockage (n = 12, 11.8%) and hemorrhage (n = 8, 7.9%). In total, 16 patients underwent at least 1 revision procedure (15.8%).

Bedside external ventricular drain placement is associated with a 15% rate of revision, that typically occurred after drain blockage and postprocedure hemorrhage. Optimal placement within the ipsilateral frontal horn or foramen of Monroe was associated with a reduced rate of drain blockage 2).

References

1)

Miller KJ, Halpern CH, Sedrak MF, Duncan JA, Grant GA. A novel mesial temporal stereotactic coordinate system. J Neurosurg. 2018 Jan 1:1-9. doi: 10.3171/2017.7.JNS162267. [Epub ahead of print] PubMed PMID: 29372873.
2)

Ramayya AG, Glauser G, Mcshane B, Branche M, Sinha S, Kvint S, Buch V, Abdullah KG, Kung D, Chen HI, Malhotra NR, Ozturk A. Factors Predicting Ventriculostomy Revision at a Large Academic Medical Center. World Neurosurg. 2018 Nov 29. pii: S1878-8750(18)32755-4. doi: 10.1016/j.wneu.2018.11.196. [Epub ahead of print] PubMed PMID: 30503293.

Trevo Retriever

The Trevo Stent Retriever is a tiny stent-shaped medical device that is attached to a thin wire. In a minimally invasive procedure that utilizes X-ray, the physician navigates the retriever from the femoral artery, which is located in the upper leg, to the blocked blood artery in the brain. The retriever is designed to ensnare the blood clot and remove it from the body. Originally cleared by the FDA in 2012, the Trevo Retriever has been used in thousands of patients worldwide.

Imahori et al., retrospectively reviewed 50 patients with acute middle cerebral artery occlusion treatment with the Trevo Stent retriever. Patients were divided into groups that achieved (1st-pass recanalization group, n=21) or did not achieve (non-1st-pass recanalization group, n=29) a modified Thrombolysis in Cerebral Ischemia score of 2b or 3 with the 1st-pass procedure. Patients were also divided into a thromboembolic (n=49) and atherosclerotic (n=11) group by occlusion etiology. They evaluated radiographic findings of the Trevo strut, e.g., degree of stent expansion and filling defect of the thrombus in the strut (in-stent thrombus sign) during the 1st-pass procedure among these groups.

The median stent expansion was significantly greater in the 1st-pass recanalization than non-1st-pass recanalization group (60% versus 34%; P<0.01), and in the thromboembolic than atherosclerotic group (45% versus 31%; P<0.01). The receiver operator characteristic curve shows moderate capacity of the prediction for recanalization and etiology, with an area under the curve of 0.83 and 0.73, respectively. The in-stent thrombus sign was significantly more common in the thromboembolic than atherosclerotic groups (86% versus 10%; P<0.01).

Greater stent expansion was associated with recanalization after thrombectomy. The in-stent thrombus sign may be useful for etiology prediction. These radiographic findings could provide useful real-time feedback during procedure, reflecting the clot-stent interaction 1).

1)

Imahori T, Okamura Y, Sakata J, Shose H, Yokote A, Matsushima K, Matsui D, Kobayashi M, Hosoda K, Tanaka K, Fujita A, Kohmura E. Stent expansion and in-stent thrombus sign in the Trevo stent retriever predict recanalization and possible etiology during mechanical thrombectomy: A case series of 50 patients with acute middle cerebral artery occlusion. World Neurosurg. 2018 Dec 28. pii: S1878-8750(18)32910-3. doi: 10.1016/j.wneu.2018.12.087. [Epub ahead of print] PubMed PMID: 30597281.
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