The following is a summary of “A rotary trans-osseous ultrasound blood flow detection method for endoscopic application,” published in the December 2023 issue of Gastroenterology by Xu et al.

The challenge of performing cervical pedicle screw fixation in clinical practice persists due to the small size and proximity of these screws to critical structures such as the spinal cord and vertebral artery. Misplacement of screws poses a substantial risk of severe complications, necessitating a focused exploration on averting direct injury to the vertebral artery during cervical spine surgery. This study proposes a trans-osseous ultrasound Doppler method to investigate the potential for detecting blood flow through delicate cortical bone.

To initiate this investigation, the investigators developed a miniature single-element prototype probe featuring a 2.5 MHz center frequency. Employing classical pulse-echo acquisition, the study group designed a Spectral Power Index (SPI) algorithm rooted in Spectral Doppler and sliding window traversal. This algorithm amplifies the Doppler signal intensity, enhancing the detection process.

Their study encompasses both in vitro and in vivo experiments aimed at probing the viability of this methodology. The in vitro experiments revealed that their approach can detect anticoagulated bovine blood flow with velocities ranging from 15 cm/s to 80 cm/s through cortical bone with a 0.7 ± 0.1 mm thickness. Additionally, researcher’s in-vivo experiment successfully detected a large blood vessel, specifically the radial artery, with a diameter of approximately 3 mm, through thin cortical bone of the same thickness (0.7 ± 0.1 mm).

The trans-osseous Doppler method showcased the ability to detect arteries through thin cortical bone, illustrating the potential for pre-warning intraoperative vessels. This methodology offers a promising avenue to mitigate the risk of vertebral artery injury and reduce misalignment rates during the insertion of cervical pedicle screws. This study proposes a strategic approach to enhance safety and accuracy in cervical spine surgical procedures.

Source: sciencedirect.com/science/article/abs/pii/S0003682X23005625