Minimally Invasive L5-S1 Oblique Lumbar Interbody Fusion With Simultaneous Robotic Single Position Posterior Fixation: 2-Dimensional Operative Video

The unique anatomy at L5-S1 presents different challenges and considerations to be made when compared to other areas in the lumbar spine. In this way, the oblique lumbar interbody fusion (OLIF) is more closely related to a supine anterior lumbar interbody fusion (ALIF) except that the former is performed in a lateral position down a smaller minimally invasive retroperitoneal corridor. This lateral positioning at L5-S1, however, provides an opportunity for single-position surgery simultaneously with posterior fixation, which is not afforded by other approaches. We present here a case of a 57-yr-old male with a prior right-sided L5-S1 microdiscectomy who presents with worsening lumbar radiculopathy and foot drop. He subsequently underwent a minimally invasive L5-S1 OLIF with posterior instrumentation placed bilaterally while remaining in a single lateral position (Mazor X Stealth Edition, Medtronic, Dublin, Ireland). Both the anterior OLIF surgeon and posterior instrumentation surgeon were able to work simultaneously. There is currently a need for further high-quality operative videos showing the L5-S1 OLIF technique, and to our knowledge, this is the first video demonstrating a 2-surgeon near-simultaneous workflow approach using a spinal robotics platform at this level. There is no identifying information in this video. A patient consent was obtained for the surgical procedure and for publishing of the material included in the video.

Creep model to determine rut development by autonomous truck axles on pavement

Impacts of autonomous truck’s passes on pavement have been analyzed in this research. Two types of lateral positioning namely zero wander and uniform wander along with a super single wide tire and a dual tire have been analyzed with variable traffic speeds in ABQUS. The study concludes with the results in favor of usage of a super single wide tire under a uniform wander mode. The highest amount of pavement damage in terms of maximum rut depth is caused by the dual wheel assembly moving under a zero-wander mode. The magnitude of rut depth increases by a factor of two when a dual tire assembly is used instead of a wide tire assembly. At a uniform wander mode, rut depth increases by 0.2 mm for every 10 km/h decrease in traffic speed within 90 km/h to 70 km/h range.

Evaluation of driver visual demand in complex two dimensional rural highway alignments

Transportation has proven to be one of the most important infrastructures in the economic development of any country. Safe and effective traffic operations support growth of the economy and help in future developments. Highway alignment design plays a crucial role in implementing safer traffic operation and management. Road accidents not only jeopardize safety, but also have a major effect on the national economy. These accidents can be divided in three classes, grouped according to their severity. Statistics in North America and Europe show that one of the major reasons for such road accidents is driver error. Wrong decisions during navigation may be the primary reason for such errors. Wrong decisions occur when a driver is unable to process the range of visual information available in a complex highway situation. Drivers need to have sufficient visual information in guiding and controlling vehicles along the correct path. Drivers scan the roadway to collect visual information. This visual information consists mainly of the traffic situation, roadway signs, and the information from the highway alignment itself. The information from the highway alignment plays a major role in decision-making during maneuvering. All drivers, therefore, need sufficient visual information for perfect navigating, and for guiding and controlling their vehicles on the road. The main focus of this research study was on evaluating visual demands on two-dimensional highway alignments with an emphasis on determining the effect of complex curves on visual demand. Complex curves are defined as combinations of simple, compound, and reverse curves in a series. Eighteen hypothetical alignments for two-lane rural highways have been developed following the standard guidelines of the Transportation Association of Canada (TAC) and American Association of State Highway Transportation Officials (AASHTO). These alignments were simulated in a low-cost driving simulator. A series of experiments was carried out using the visual occlusion method. Nine subject drivers drove in the simulator, and the output data related to visual demand information and positioning of the subject vehicle were connected. The data relating to visual demand information and lateral positioning on curves and tangents were processed using Microsoft ExceFM and analyzed using SAS, a statistical software. The turning directions, characteristics of preceding elements, and the combination of curve to curve, tangent to curve, or curve to tangent have been considered as nominal variables and analyzed as independent variables with visual demand. It has been observed that visual demand varies widely with the inverse of radius of curvature of the preceding and current elements, and the characteristics of the combination of the current and the preceding element. Visual demand also varies on identical tangents, depending on the deflection angle, inverse of radius, and turning direction of the preceding curve. The standard deviation of lateral positioning of the subject vehicle was evaluated with respect to the centre-line of the driving lane. This was supposed to have a considerable impact on visual demand evaluation, but it has been observed that this does not bear any significant relationship to visual demand. In addition to curves, tangents, as preceding elements have an immense impact on visual demand evaluation on following curves. Besides, visual demand on tangents has also been observed as highly dependent on the preceding curve and their turning directions.

Evaluation of driver visual demand in complex two dimensional rural highway alignments

Transportation has proven to be one of the most important infrastructures in the economic development of any country. Safe and effective traffic operations support growth of the economy and help in future developments. Highway alignment design plays a crucial role in implementing safer traffic operation and management. Road accidents not only jeopardize safety, but also have a major effect on the national economy. These accidents can be divided in three classes, grouped according to their severity. Statistics in North America and Europe show that one of the major reasons for such road accidents is driver error. Wrong decisions during navigation may be the primary reason for such errors. Wrong decisions occur when a driver is unable to process the range of visual information available in a complex highway situation. Drivers need to have sufficient visual information in guiding and controlling vehicles along the correct path. Drivers scan the roadway to collect visual information. This visual information consists mainly of the traffic situation, roadway signs, and the information from the highway alignment itself. The information from the highway alignment plays a major role in decision-making during maneuvering. All drivers, therefore, need sufficient visual information for perfect navigating, and for guiding and controlling their vehicles on the road. The main focus of this research study was on evaluating visual demands on two-dimensional highway alignments with an emphasis on determining the effect of complex curves on visual demand. Complex curves are defined as combinations of simple, compound, and reverse curves in a series. Eighteen hypothetical alignments for two-lane rural highways have been developed following the standard guidelines of the Transportation Association of Canada (TAC) and American Association of State Highway Transportation Officials (AASHTO). These alignments were simulated in a low-cost driving simulator. A series of experiments was carried out using the visual occlusion method. Nine subject drivers drove in the simulator, and the output data related to visual demand information and positioning of the subject vehicle were connected. The data relating to visual demand information and lateral positioning on curves and tangents were processed using Microsoft ExceFM and analyzed using SAS, a statistical software. The turning directions, characteristics of preceding elements, and the combination of curve to curve, tangent to curve, or curve to tangent have been considered as nominal variables and analyzed as independent variables with visual demand. It has been observed that visual demand varies widely with the inverse of radius of curvature of the preceding and current elements, and the characteristics of the combination of the current and the preceding element. Visual demand also varies on identical tangents, depending on the deflection angle, inverse of radius, and turning direction of the preceding curve. The standard deviation of lateral positioning of the subject vehicle was evaluated with respect to the centre-line of the driving lane. This was supposed to have a considerable impact on visual demand evaluation, but it has been observed that this does not bear any significant relationship to visual demand. In addition to curves, tangents, as preceding elements have an immense impact on visual demand evaluation on following curves. Besides, visual demand on tangents has also been observed as highly dependent on the preceding curve and their turning directions.

Combined Endovascular and Microsurgical Management of a Tentorial Arteriovenous Malformation in a Hybrid Neurovascular Operating Room: 2-Dimensional Operative Video

Tentorial margin arteriovenous malformations (AVMs) at the cerebello-mesencephalic fissure are deep lesions, which can be safely resected via a lateral supracerebellar infratentorial approach. This video illustrates the case of a patient who presented with hemorrhage from a tentorial AVM. He was managed in the hybrid neurovascular operating room with Onyx (Medtronic) embolization of a superior cerebellar artery feeder followed by resection of the AVM, which included cerebellar relaxation from lumbar cerebrospinal fluid (CSF) drainage and lateral positioning. Wide cisternal arachnoid dissection at the quadrigeminal cistern allowed for a straight trajectory to the AVM without fixed retraction. Intraoperative transradial angiography confirmed complete AVM exclusion. This video was deemed Institutional Review Board (IRB) exempt by the University of Pennsylvania IRB as it is considered a case report, which does not require IRB approval or patient consent. The patient consented to the procedure.

Targeted lateral positioning decreases lung collapse and overdistension in COVID-19-associated ARDS

Background Among the challenges for personalizing the management of mechanically ventilated patients with coronavirus disease (COVID-19)-associated acute respiratory distress syndrome (ARDS) are the effects of different positive end-expiratory pressure (PEEP) levels and body positions in regional lung mechanics. Right-left lung aeration asymmetry and poorly recruitable lungs with increased recruitability with alternating body position between supine and prone have been reported. However, real-time effects of changing body position and PEEP on regional overdistension and collapse, in individual patients, remain largely unknown and not timely monitored. The aim of this study was to individualize PEEP and body positioning in order to reduce the mechanisms of ventilator-induced lung injury: collapse and overdistension. Methods We here report a series of five consecutive mechanically ventilated patients with COVID-19-associated ARDS in which sixteen decremental PEEP titrations were performed in the first days of mechanical ventilation (8 titration pairs: supine position immediately followed by 30° targeted lateral position). The choice of lateral tilt was based on X-Ray. This targeted lateral position strategy was defined by selecting the less aerated lung to be positioned up and the more aerated lung to be positioned down. For each PEEP level, global and regional collapse and overdistension maps and percentages were measured by electrical impedance tomography. Additionally, we present the incidence of lateral asymmetry in a cohort of forty-four patients. Results The targeted lateral position strategy resulted in significantly smaller amounts of overdistension and collapse when compared with the supine one: less collapse along the PEEP titration was found within the left lung in targeted lateral (P = 0.014); and less overdistension along the PEEP titration was found within the right lung in targeted lateral (P = 0.005). Regarding collapse within the right lung and overdistension within the left lung: no differences were found for position. In the cohort of forty-four patients, ventilation inequality of > 65/35% was observed in 15% of cases. Conclusions Targeted lateral positioning with bedside personalized PEEP provided a selective attenuation of overdistension and collapse in mechanically ventilated patients with COVID-19-associated ARDS and right-left lung aeration/ventilation asymmetry. Trial registration Trial registration number: NCT04460859

Changes in the Bronchial Cuff Pressure of Left-Sided Double-Lumen Endotracheal Tube by Lateral Positioning: A Prospective Observational Study

Proper bronchial cuff pressure (BCP) is important when using a double-lumen endotracheal tube (DLT), especially in thoracic surgery. As positional change during endotracheal tube placement could alter cuff pressure, we aim to evaluate the change in BCP of DLT from the supine to the lateral decubitus position during thoracic surgery. A total of 69 patients aged 18–70 years who underwent elective lung surgery were recruited. BCP was measured at a series of time points in the supine and lateral decubitus positions after confirming the DLT placement. The primary outcome was change in the initial established BCP (BCPi), which is the maximum pressure at which the BCP did not exceed 40 cmH2O without air leak in the supine position, after lateral decubitus positioning. As the primary outcome, the BCPi increased from 25.4 ± 9.0 cmH2O in the supine position to 29.1 ± 12.2 cmH2O in the lateral decubitus position (p < 0.001). Out of the 69 participants, 43 and 26 patients underwent surgery in the left-lateral decubitus position (LLD group) and the right-lateral decubitus position (RLD group) respectively. In the LLD group, the BCPi increased significantly (p < 0.001) after lateral positioning and the beginning of surgery and the difference value, ∆BCPi, from supine to lateral position was significantly higher in the LLD group than in the RLD group (p = 0.034). Positional change from supine to lateral decubitus could increase the BCPi of DLT and the increase was significantly greater in LLD that in RLD.

Targeted Lateral Positioning Decreases Lung Collapse and Overdistension in COVID-19-Associated ARDS

Background Among the challenges for personalizing the management of mechanically ventilated patients with coronavirus disease (COVID-19)-associated acute respiratory distress syndrome (ARDS) are the effects of different positive end-expiratory pressure (PEEP) levels and body positions in regional lung mechanics. Right-left lung aeration asymmetry and poorly recruitable lungs with increased recruitability with alternating body position between supine and prone have been reported. However, real-time effects of changing body position and PEEP on regional overdistension and collapse, in individual patients, remain largely unknown and not timely monitored. Methods We here report a series of consecutive mechanically ventilated patients with COVID-19-associated ARDS. Aiming at to individualize PEEP and body positioning in order to reduce mechanisms of ventilator-induced lung injury, collapse and overdistension, sixteen decremental PEEP titrations were performed in the first days of mechanical ventilation (8 pairs supine vs. targeted lateral position): supine position immediately followed by 30° targeted lateral position. The choice of lateral tilt was based on X-Ray: the less aerated lung was positioned up. Maps and percentages of global and regional collapse and overdistension were measured for each PEEP level by electrical impedance tomography. Results Targeted lateral position resulted in significantly smaller amounts of overdistension and collapse when compared with the supine one: less collapse along the PEEP titration was found within the left lung in targeted lateral; and less overdistension along the PEEP titration was found within the right lung in targeted lateral. Regarding collapse within the right lung and overdistension within the left lung: no differences were found for position. Conclusions Targeted lateral positioning with bedside personalized PEEP provided a selective attenuation of overdistension and collapse in mechanically ventilated patients with COVID-19-associated ARDS and right-left lung aeration/ventilation asymmetry.