Essential updates 2020/2021 : Current topics of simulation and navigation in hepatectomy

With the development of three-dimensional (3D) simulation software, preoperative simulation technology is almost completely established. The remaining issue is how to recognize anatomy three-dimensionally. Extended reality is a newly developed technology with several merits for surgical application: no requirement for a sterilized display monitor, better spatial awareness, and the ability to share 3D images among all surgeons. Various technology or devices for intraoperative navigation have also been developed to support the safety and certainty of liver surgery. Consensus recommendations regarding indocyanine green fluorescence were determined in 2021. Extended reality has also been applied to intraoperative navigation, and artificial intelligence (AI) is one of the topics of real-time navigation. AI might overcome the problem of liver deformity with automatic registration. Including the issues described above, this article focuses on recent advances in simulation and navigation in liver surgery from 2020 to 2021

Major Depressive Disorder Complicated with Spinocerebellar Ataxia: Report of 2 Cases

Background: It is known that patients with spinocerebellar ataxia (SCA) tend to exhibit depressive symptoms. But the pathology of depressive symptoms complicated with SCA, including the reaction to the stress resulting from decreased motor function and central dysfunction due to neurodegeneration, is controversial and remains to be elucidated. To our knowledge, there have been hardly any reports on treatment methods of major depressive disorder (MDD) complicated with SCA. Case Reports: We report 2 cases in which selective serotonin reuptake inhibitors (SSRIs) were effective against MDD complicated with SCA. Interestingly, one of the patients developed the symptoms of spinocerebellar degeneration (SCD) during the course of the MDD, and the other patient developed the symptoms of MDD during the course of SCA, but complete remission of the MDD occurred in both cases. In our cases, the depressive symptoms may have been caused mainly by an abnormality of reversible neural transmission including serotonin transmission due to central dysfunction, and there is the unlikely possibility that the depressive symptoms are reactive to the stress due to decreased motor function, because the depressive symptoms decreased with SSRIs. Conclusion: Although cerebellar degeneration is irreversible in SCA patients, our cases suggest that MDD complicated with SCA may be reversible and treatable using antidepressants such as SSRIs with few adverse events. Therefore, it is important for neurologists to detect MDD complicated with SCA early and consult a psychiatrist in order to improve quality of life of SCA patients

Influence of brain-derived neurotrophic factor on pathfinding of dentate granule cell axons, the hippocampal mossy fibers

Mossy fibers, the dentate granule cell axons, are generated throughout an animal's lifetime. Mossy fiber paths and synapses are primarily restricted to the stratum lucidum within the CA3 region. Brain-derived neurotrophic factor (BDNF), a neurotrophin family protein that activates Trk neurotrophin receptors, is highly expressed in the stratum lucidum in an activity-dependent manner. The addition of a Trk neurotrophin receptor inhibitor, K252a, to cultured hippocampal slices induced aberrant extension of mossy fibers into ectopic regions. BDNF overexpression in granule cells ameliorated the mossy fiber pathway abnormalities caused by a submaximal dose of K252a. A similar rescue was observed when BDNF was expressed in CA3 pyramidal cells, most notably in mossy fibers distal to the expression site. These findings are the first to clarify the role of BDNF in mossy fiber pathfinding, not as an attractant cue but as a regulator, possibly acting in a paracrine manner. This effect of BDNF may be as a signal for new fibers to fasciculate and extend further to form synapses with neurons that are far from active BDNF-expressing synapses. This mechanism would ensure the emergence of new independent dentate gyrus-CA3 circuits by the axons of new-born granule cells

Intraoperative 3D hologram in liver surgery

An intra-operative 3D hologram with mixed reality techniques contributed to “last-minute simulation”, not for “navigation” in liver surgery. This intra-operative hologram might be a new next-generation operation-supportive tool in terms of spatial awareness, sharing, and simplicity.Objective The aim of this study was to investigate the potential of an intra-operative 3D hologram, which was a computer graphics (CG) model liver, with mixed reality (MR) techniques in liver surgery. Summary Background Data The merits for the application of a hologram for surgical support are: 1) no sterilized display monitor; 2) better spatial awareness; and 3) 3D images shared by all the surgeons. Methods 3D polygon data using pre-operative computed tomography (CT) data was installed into head mount displays, HoloLens (Microsoft Corporation, Redmond, WA). Results In a Wi-Fi-enabled operative room, several surgeons wearing HoloLens succeeded in sharing the same hologram and moving that hologram from respective operators’ angles by means of easy gesture-handling without any monitors. The intra-operative hologram contributed to better imagination of tumor locations, and for determining the parenchymal dissection line in the hepatectomy for the patients with more than twenty (20) multiple colo-rectal liver metastases (CRLMs). In another case, the hologram enabled a safe Gliisonean pedicle approach for hepato-cellular carcinoma (HCC) with a hilar anatomical anomaly. Surgeons could easily compare the real patient’s anatomy and that of the hologram just before the hepatic hilar procedure. Conclusions This initial experience suggested that an intra-operative hologram with MR techniques contributed to “last-minute simulation”, not for “navigation”. The intra-operative hologram might be a new next-generation operation-supportive tool in terms of spatial awareness, sharing, and simplicity

Differences in Obstetric Care Between Japan and the US: A Qualitative Analysis of Blogs

Aim To investigate patient-reported differences in obstetric care between Japan and the US by characterizing the information Japanese immigrants and expatriates share online