Construction of brain area risk map for decision making using surgical navigation and motor evoked potential monitoring information.

PURPOSE: Surgical devices or systems typically operate in a stand-alone manner, making it difficult to perform integration analysis of both intraoperative anatomical and functional information. To address this issue, the intraoperative information integration system OPeLiNK® was developed. The objective of this study is to generate information for decision making using surgical navigation and intraoperative monitoring information accumulated in the OPeLiNK® database and to analyze its utility. METHODS: We accumulated intraoperative information from 27 brain tumor patients who underwent resection surgery. First, the risk rank for postoperative paralysis was set according to the attenuation rate and amplitude width of the motor evoked potential (MEP). Then, the MEP and navigation log data were combined and plotted on an intraoperative magnetic resonance image of the individual brain. Finally, statistical parametric mapping (SPM) transformation was performed to generate a standard brain risk map of postoperative paralysis. Additionally, we determined the anatomical high-risk areas using atlases and analyzed the relationship with each set risk rank. RESULTS: The average distance between the navigation log corresponding to each MEP risk rank and the anatomical high-risk area differed significantly between the with postoperatively paralyzed and without postoperatively paralyzed groups, except for "safe." Furthermore, no excessive deformation was observed resulting from SPM conversion to create the standard brain risk map. There were cases in which no postoperative paralysis occurred even when MEP decreased intraoperatively, and vice versa. CONCLUSION: The time synchronization reliability of the study data is very high. Therefore, our created risk map can be reported as being functional at indicating the risk areas. Our results suggest that the statistical risks of postoperative complications can be presented for each area where brain surgery is to be performed. In the future, it will be possible to provide surgical navigation with intraoperative support that reflects the risk maps created.

The iArmS Robotic Armrest Prolongs Endoscope Lens-Wiping Intervals in Endoscopic Sinus Surgery.

Objective. Fouling of the endoscope lens is a major problem in endoscopic sinus surgery (ESS). We examined whether the use of the intelligent arm support system (iArmS), a robotic armrest, could prolong endoscope lens-wiping intervals in ESS and thus allow for continuously clear endoscopic images. Study Design. This study is a prospective, nonrandomized crossover study. Methods. Three surgeons who performed ESS at 2 centers each conducted 3 operations with the iArmS and 3 operations without the iArmS; thus, 18 operations were assessed. To blind the assessments, we performed them prospectively without informing subjects of the endpoints. We recorded the operations and observed the recordings at a later date; endoscope lens-wiping times were noted in seconds to determine the endoscope lens-wiping intervals. Our examination was based on the null hypothesis that endoscope lens-wiping intervals would not differ according to the use or nonuse of the iArmS. Results. The median endoscope lens-wiping intervals with and without using the iArmS were 361 seconds and 135 seconds, respectively. Based on the Wilcoxon rank-sum test, this difference was significant (P = 0.001); thus, the null hypothesis was rejected. This result indicated that endoscope lens-wiping intervals are greatly prolonged by the use of the iArmS. Conclusion. The iArmS robotic armrest is suitable for ESS, prolongs endoscope lens-wiping intervals, and facilitates obtaining continuous clear endoscopic images.

An armrest is effective for reducing hand tremble in neurosurgeons.

Experienced neurosurgeons reduce hand tremble by placing their hand beside the operative field when performing microneurosurgery conventionally. Another solution to reduce hand tremble is an armrest. However, the reduction of hand tremble by using an armrest or finger-placing technique has not been rigorously measured in microneurosurgery. This study was performed to provide a quantitative assessment of the efficacy of an armrest to reduce hand tremble in comparison with the finger-placing technique. Hand tremble was evaluated in 11 board-certified neurosurgeons in a simulated microneurosurgery. The loci of surgical forceps handled by neurosurgeons were measured by a three-dimensional optical coordinate measuring machine. A static task was performed under four conditions: with/without the finger-placing technique and/or an armrest. The radius of an imaginative sphere including 95% of each locus was calculated and reviewed according to the four conditions. Hand tremble was significantly larger when the finger-placing technique was not implemented compared to when the technique was used (P<0.05). The armrest also reduced hand tremble (P<0.05) similar to the finger-placing technique. Non-inferiority was retained between the finger-placing technique and the armrest. Concomitant use of the armrest and the finger-placing technique did not interfere with the efficacy of the technique to reduce neurosurgeon's hand tremble. The finger-placing technique was confirmed to reduce hand tremble. Resting the neurosurgeon's forearm on an armrest also reduced the hand tremble. An armrest is a device that reduces hand tremble in neurosurgeons like the finger-placing technique.