Evaluating the Efficacy of a Novel Side-Support Surgical Tray Stand for Endoscopic Transnasal Skull Base Surgery: A Prospective Study

Objective Endoscopic transnasal skull base surgery is a valuable technique used in the surgical treatment of various skull base pathologies. In such surgeries, the reconstruction of the skull base is crucial for surgical success and minimizing complications. This study presents a new side-support surgical tray designed to improve the exposure of the lateral femoral surgical area during surgery, enhancing surgical efficiency and reducing the risk of surgical complications. The study compared this innovative tray stand with the conventional double-sided support tray stand to evaluate its impact on surgical procedures and complications. Materials and methods The study prospectively analyzed 248 endoscopic transnasal skull base surgeries requiring lateral femoral autologous tissue harvesting. One hundred fifty-eight cases were performed using the side-support surgical tray stand (experimental group), while 90 cases used the conventional double-sided support tray stand (control group). Various parameters were evaluated, including satisfaction scores of surgeons, circulating nurses, instrument nurses, and anesthetists, as well as objective outcomes such as surgical duration and the incidence of complications. Results Surgeons in the experimental group expressed higher satisfaction with the surgical field exposure and the portability of the surgical tray stand compared to the control group. Likewise, circulating nurses in the experimental group reported greater satisfaction with the installation and portability, surpassing that of the control group (p< 0.01). Although the stability of instrument nurses in the experimental group was slightly less than that of the control group, it had no discernible impact on surgical cooperation. Anaesthesiologists in the experimental group exhibited higher satisfaction regarding the convenience of intraoperative monitoring and management than their counterparts in the control group. The average duration required for intraoperative autologous tissue harvesting in the experimental group was significantly shorter than in the control group (p < 0.01). Furthermore, the incidence of postoperative wound infections and intracranial infections in the experimental group was notably lower than in the control group (would infections, p = 0.046; intracranial infection, p = 0.025). Conclusion The novel side-support surgical tray stand effectively improves surgical exposure, convenience, and safety while reducing the risk of surgical site and intracranial infections. It also shortens surgical duration and lowers complication rates, making it a suitable choice for clinical application.

Obese Occupant Response in Reclined and Upright Seated Postures in Frontal Impacts

The American population is getting heavier and automated vehicles will accommodate unconventional postures. While studies replicating mid-size and upright fore-aft seated occupants are numerous, experiments with post-mortem human subjects (PMHS) with obese and reclined occupants are sparse. The objective of this study was to compare the kinematics of the head-neck, torso and pelvis, and document injuries and injury patterns in frontal impacts. Six PMHS with a mean body mass index of 38.2 ± 5.3 kg/m2 were equally divided between upright and reclined groups (seatback: 23°, 45°), restrained by a three-point integrated belt, positioned on a semi-rigid seat, and exposed to low and moderate velocities (15, 32 km/h). Data included belt loads, spinal accelerations, kinematics, and injuries from x-rays, computed tomography, and necropsy. At 15 km/h speed, no significant difference in the occupant kinematics and evidence of orthopedic failure was observed. At 32 km/h speed, the primary difference between the cohorts was significantly larger Z displacements in the reclined occupant at the head (190 ± 32 mm, vs. 105 ± 33 mm p < 0.05) and femur (52 ± 18 mm vs. 30 ± 10 mm, p < 0.05). All the moderate-speed tests produced at least one thorax injury. Rib fractures were scattered around the circumference of the rib-cage in the upright, while they were primarily concentrated on the anterior aspect of the rib-cage in two reclined specimens. Although MAIS was the same in both groups, the reclined specimens had more bi-cortical rib fractures, suggesting the potential for pneumothorax. While not statistical, these results suggest enhanced injuries with reclined obese occupants. These results could serve as a data set for validating the response of restrained obese anthropometric test device (ATDs) and computational human body models.

Please Place Your Seat in the Full Upright Position: A Technical Framework for Landing Upright Radiation Therapy in the 21st Century

Delivering radiotherapy to patients in an upright position can allow for increased patient comfort, reduction in normal tissue irradiation, or reduction of machine size and complexity. This paper gives an overview of the requirements for the delivery of contemporary arc and modulated radiation therapy to upright patients. We explore i) patient positioning and immobilization, ii) simulation imaging, iii) treatment planning and iv) online setup and image guidance. Treatment chairs have been designed to reproducibly position seated patients for treatment and can be augmented by several existing immobilisation systems or promising emerging technologies such as soft robotics. There are few solutions for acquiring CT images for upright patients, however, cone beam computed tomography (CBCT) scans of upright patients can be produced using the imaging capabilities of standard Linacs combined with an additional patient rotation device. While these images will require corrections to make them appropriate for treatment planning, several methods indicate the viability of this approach. Treatment planning is largely unchanged apart from translating gantry rotation to patient rotation, allowing for a fixed beam with a patient rotating relative to it. Rotation can be provided by a turntable during treatment delivery. Imaging the patient with the same machinery as used in treatment could be advantageous for online plan adaption. While the current focus is using clinical linacs in existing facilities, developments in this area could also extend to lower-cost and mobile linacs and heavy ion therapy.

Upright Radiation Therapy-A Historical Reflection and Opportunities for Future Applications

Since the early days of megavoltage Radiation Therapy (RT), the potential of delivering treatment to a sub group of patients in an upright position has been recognized. Compared to lying horizontally, treating patients in an upright position offers potential benefits in terms of patient comfort especially for patients experiencing dyspnoea and saliva accumulation when lying down. Dosimetric benefits can also be gained from changes in the volume and location of lungs and heart in an upright position, which are potentially advantageous for clinical situations including Hodgkin's disease, lung and breast malignancies. Since the 1950's, upright stabilization mechanisms have ranged from standalone chair based apparatus to couch-top attachments with increasingly customizable solutions. The introduction of Computed-Tomography (CT) based three-dimensional (3D) dosimetry in the 1980's−90's necessitated image acquisition in a horizontal position (supine or prone), significantly reducing options for alternative patient positioning and upright techniques. Despite this, upright techniques have still been utilized where clinically indicated for palliative and novel approaches often involving non-standard treatment scenarios. More recently, a small number of centers have reported on specialized equipment capable of acquiring planning data with the patient in a vertical position. The possibility of acquiring planning quality Cone Beam CT (CBCT) on linear accelerators has recently reinvigorated the potential to deliver highly accurate and targeted treatments to patients in an upright position. This paper reflects on the historical applications of upright RT and explores new possibilities for this technology in modern RT departments.

Gravity estimation and verticality perception

Gravity is a defining force that governs the evolution of mechanical forms, shapes and anchors our perception of the environment, and imposes fundamental constraints on our interactions with the world. Within the animal kingdom, humans are relatively unique in having evolved a vertical, bipedal posture. Although a vertical posture confers numerous benefits, it also renders us less stable than quadrupeds, increasing susceptibility to falls. The ability to accurately and precisely estimate our orientation relative to gravity is therefore of utmost importance. Here we review sensory information and computational processes underlying gravity estimation and verticality perception. Central to gravity estimation and verticality perception is multisensory cue combination, which serves to improve the precision of perception and resolve ambiguities in sensory representations by combining information from across the visual, vestibular, and somatosensory systems. We additionally review experimental paradigms for evaluating verticality perception, and discuss how particular disorders affect the perception of upright. Together, the work reviewed here highlights the critical role of multisensory cue combination in gravity estimation, verticality perception, and creating stable gravity-centered representations of our environment.

Imaging Posture Veils Neural Signals

Whereas modern brain imaging often demands holding body positions incongruent with everyday life, posture governs both neural activity and cognitive performance. Humans commonly perform while upright; yet, many neuroimaging methodologies require participants to remain motionless and adhere to non-ecological comportments within a confined space. This inconsistency between ecological postures and imaging constraints undermines the transferability and generalizability of many a neuroimaging assay. Here we highlight the influence of posture on brain function and behavior. Specifically, we challenge the tacit assumption that brain processes and cognitive performance are comparable across a spectrum of positions. We provide an integrative synthesis regarding the increasingly prominent influence of imaging postures on autonomic function, mental capacity, sensory thresholds, and neural activity. Arguing that neuroimagers and cognitive scientists could benefit from considering the influence posture wields on both general functioning and brain activity, we examine existing imaging technologies and the potential of portable and versatile imaging devices (e.g., functional near infrared spectroscopy). Finally, we discuss ways that accounting for posture may help unveil the complex brain processes of everyday cognition.

Soft Tissue Attenuation Patterns Associated with Upright Acquisition SPECT Myocardial Perfusion Imaging: A Descriptive Study

Background:

Little is known about soft tissue attenuation artifacts when an upright patient-position SPECTmyocardial perfusion imaging (MPI) system is used. In this investigation we sought to describe the patterns and frequency of attenuation artifacts associated with this type of instruments and we explored the impact of gender and body habitus on these artifacts.

Methods:

In a cross-sectional study, we described the prevalence of various soft-tissue attenuation patterns in 212 normal SPECT-MPI studies acquired with an upright patient-position imaging system.

Results:

In these 212 normal, clinically-indicated, upright-acquisition SPECT-MPIs the attenuation patterns observed were: anterior (6.1%), inferior (63.7%) and lateral (24.1%). Though uncommon, anterior attenuation trended to being more prevalent among women [9.5% vs. 3.4%, P=0.07] and was independently associated with chest circumference. Lateral attenuation was more common among women [34.7% vs. 15.4%, p=0.001] and was strongly associated with obesity (p<0.001). Inferior attenuation was more prevalent among men than women (75.2% vs. 49.5% respectively, P<0.001).

Conclusions:

Soft-tissue attenuation artifacts are common in upright-acquisition SPECT-MPI. Recognizing the frequency of these attenuation patterns and their interaction with gender and body habitus is critical for the accurate interpretation of SPECT-MPI.

Eyelash inversion in epiblepharon: Is it caused by redundant skin?

PURPOSE

To evaluate the effect of redundant lower eyelid skin on the eyelash direction in epiblepharon.

MATERIALS AND METHODS

Asian patients with epiblepharon participated in this study. The lower eyelid skin was pulled downward in the upright position with the extent just to detach from eyelash roots, and the direction of the eyelashes was examined. These evaluations were repeated before surgery while the patients were lying supine under general anesthesia.

RESULTS

The study included 41 lower eyelids of 25 patients (17 females, 8 males, average age; 5.6 years, 16 cases bilateral, 9 unilateral). In the upright position, without downward traction of the skin, the eyelashes were vertically positioned and touching the cornea. The redundant skin touched only the eyelash roots and had minimal contribution to eyelash inversion. With downward skin traction, there was no significant change in the eyelash direction. In the spine position, the eyelashes were touching the cornea, and there was marked redundant skin that was pushing the eyelashes inward. With downward skin traction, there was no significant change.

CONCLUSIONS

The direction of lower eyelashes in patients with epiblepharon was less influenced by lower eyelid skin redundancy than previously considered. The redundant skin is only a possible aggravating factor to epiblepharon.