The Accuro automatic spinal navigation system (Rivanna Medical) significantly enhanced the accuracy of epidural and spinal anaesthesia placement compared to traditional landmark techniques, even for residents-in-training and patients with atypical spinal anatomy, according to three abstracts presented at the annual meeting of the Society for Obstetric Anesthesia and Perinatology (SOAP; 10–14 May, Bellevue, USA).
Accuro is a pocket-sized ultrasound system that uses specialised algorithms designed to automatically detect spinal midline and epidural depth and trajectory. The device is optimised for visualisation of bony anatomy and is intended to eliminate the steep learning curve required for accurate ultrasound interpretation.
Presented at the meeting were the results of a randomised trial conducted at the University of Virginia Medical Center (Charlottesville, USA) comparing anaesthesiology residents’ success placing spinal anesthesia in Caesarean-section patients with Accuro guidance and with conventional methods. Participants were not experienced in ultrasound reading and received a brief 10-minute training session on Accuro operation.
The trial found that for residents with prior spinal anaesthesia experience, Accuro improved first-attempt needle placement by more than 100% in patients with a high body mass index. For these residents, the average number of needle redirections to achieve placement using Accuro was almost half that of the same sub-group using conventional placement methods.
In a second clinical trial conducted at Stanford University Medical Center (Stanford, USA), automated Accuro imaging technology successfully identified the location and depth for optimal epidural anaesthesia administration with essentially equivalent accuracy to traditional ultrasound images read by an experienced interpreter. Researchers also found that real needle depth to the epidural space measured after successful delivery significantly correlated with Accuro’s initial assessment.
Additionally, Accuro identified the appropriate spinal interspace for needle insertion in 94% of patients. Its automated image navigation enabled 87% success in first-attempt epidural administration for participating physicians, who were primarily anesthesia residents.
This study was conducted under the direction of Brendan Carvalho, at Stanford Medical Center and led by Katherine Seligman, who is currently faculty at the University of New Mexico, Albuquerque, USA.
A third SOAP presentation focused on the case history of a pregnant patient with severe scoliosis who received epidural anesthesia under Accuro guidance at Rutgers-New Jersey Medical School (Newark, USA). Prior surgical scoliosis treatment had resulted in significant scarring and additional anatomical distortion. Rivanna’s Accuro successfully identified bony landmarks and the optimal spinal interspaces for anesthesia delivery. Ultimately, the procedure was successfully performed with first-time needle placement, followed by a single manipulation.
Authors note that conventionally delivered spinal anaesthesia for severe scoliosis patients typically involves multiple needle insertions, extended procedure time and elevated risk of complications. They believe that Accuro’s automated recognition of the spinal midline and epidural depth contributed significantly to the procedure’s success, according to a company release.