RESUMEN
Introduction: Sacroiliac joint fusion (SIJF) is a minimally invasive treatment for sacroiliac (SI) dysfunction. It involves placing implants through the SI joint under fluoroscopic guidance, requiring precise implant positioning to avoid nerve injury. Preoperative virtual surgical planning (VSP) aids in optimal positioning, but replicating it accurately in the operating room is challenging. Research question: This study aims to assess the feasibility of superimposing VSP onto intraoperative fluoroscopic images to aid in optimal implant placement. Material and methods: A method for intraoperative guidance using 3D/2D registration was developed and tested during SIJF as an available and potentially efficient alternative for costly and more invasive navigation systems. Preoperatively, a VSP is performed and simulated fluoroscopic images are generated from a preoperative CT scan. During surgery, the simulated image that visually best matches the intraoperative fluoroscopic image is selected. Subsequently, the VSP is superimposed onto the intraoperative fluoroscopic image using a developed script-based workflow. The surgeon then places the implants accordingly. Postoperative implant placement accuracy was evaluated. Results: Five interventions were performed on five patients, resulting in a total of 15 placed implants. Minor complications without clinical consequences occurred in one case, primarily attributable to the patient's anatomy and pathological manifestations. Mean deviations at implant apex and 3D angle were 4.7 ± 1.6 mm and 3.5 ± 1.3°, respectively. Discussion and conclusions: The developed intraoperative workflow was feasible and resulted in implants placed with low deviations from the VSP. Further research is needed to automate and validate this method in a larger cohort.
RESUMEN
BACKGROUND: The life expectancy of patients with a continuous flow left ventricular assist device (cf-LVAD) is increasing. Adequate determination and regulation of mean arterial pressure (MAP) is important to prevent adverse events. Given the low pulsatility characteristics in these patients, standard blood pressure equipment is inadequate to monitor MAP and not recommended. We provide an overview of currently available noninvasive techniques, using an extensive search strategy in three online databases (Pubmed, Scopus and Google Scholar) to find validation studies using invasive intra-arterial blood pressure measurement as a reference. Mean differences with the reference values smaller than 5 ± 8 mm Hg were considered acceptable. OBSERVATIONS: After deduplication, screening, and exclusion of incorrect sources, eleven studies remained with 3139 successful MAP measurements in 386 patients. Four noninvasive techniques, using Doppler, pulse oximetry, finger cuff volume clamp, or slow upper arm cuff deflation, were identified and evaluated for validity and success rate in cf-LVAD patients. Here, a comprehensive technical background of the blood pressure measurement methods is provided in combination with a clinical use comparison. Of the reported noninvasive techniques, slow cuff devices performed most optimally (mean difference 1.3 ± 5.2 mm Hg). CONCLUSIONS: Our results are encouraging and indicate that noninvasive blood pressure monitoring options with acceptable validity and success rate are available. Further technical development and validation is warranted for the growing population of patients on long-term cf-LVAD support.