Radiation Dose and Fluoroscopy Time of Diagnostic Angiography in Patients with Spinal Dural Arteriovenous Fistula

Purpose Spinal dural arteriovenous fistulas (SDAVFs) represent the most common indication for a spinal angiography. The diagnostic reference level (DRL) for this specific endovascular procedure is still to be determined. This single-center study provides detailed dosimetrics of diagnostic spinal angiography performed in patients with SDAVFs. Methods Retrospective analysis of all diagnostic spinal angiographies between December 2011 and January 2021. Only patients with an SDAVF who had baseline magnetic resonance angiography (MRA), diagnostic digital subtraction angiography (DSA), treatment and follow-up at this institution were included. Dose area product (DAP, Gy cm2) and fluoroscopy time were compared between preoperative and postoperative angiographies, according to SDAVF locations (common versus uncommon), MRA results at baseline (positive versus negative) and DSA protocols (low-dose, mixed-dose, normal-dose). The 75th percentile of the DAP distribution was used to define the local DRL. Results A total of 62 spinal angiographies were performed in 25 patients with SDAVF. Preoperative angiographies (30/62, 48%) yielded a significantly higher DAP and longer fluoroscopy time when compared to postoperative angiographies (32/62, 53%) (p < 0.01). The local DRL was 329.41 Gy cm2 for a nonspecific (n = 62), 395.59 Gy cm2 for a preoperative and 138.6 Gy cm2 for a postoperative spinal angiography. Preoperative angiography of uncommonly located SDAVFs yielded a significantly longer fluoroscopy time (p = 0.02). The MRA-based fistula detection had no significant impact on dosimetrics (p > 0.05). A low-dose protocol yielded a 61% reduction of DAP. Conclusion The results of the present study suggest novel DRLs for spinal angiography in patients with SDAVF. Dedicated low-dose protocols enable radiation dose optimization in these procedures.

Robotic assistant spinal angiography: a case report and technical considerations

Robotic-assisted technology has shown to be promising in coronary and peripheral vascular interventions. Early case reports have also demonstrated its efficacy in neuro-interventions. However, there is no prior report demonstrating use of the robotic-assisted platform for spinal angiography. We report the feasibility of the robotic-assisted thoracic and lumbar spinal angiography.

Safety of diagnostic spinal angiography in children

BackgroundSpinal angiography (SA) is associated with low complications in adults but its safety in children has not been properly analyzed. The goal of our study is to assess the safety of pediatric SA.MethodsThis study is the retrospective analysis of a series of 36 consecutive SA procedures performed in 27 children over a 5-year period. Parameters including neurological complications, non-neurological complications requiring additional management, contrast volume, and radiation exposure were analyzed via univariate and bivariate methods.ResultsOur cohort included 24 diagnostic and 12 combined therapeutic cases in children with an average age of 11.1 years. No neurological or non-neurological complication requiring additional management was recorded. The average volume of contrast administered was 1.6 mL/kg in the diagnostic group and 0.9 mL/kg in the combined group. The average air kerma was 186.9mGy for an average of 36.8 exposures in the diagnostic group, and 264.5mGy for an average of 21 exposures in the combined group. Patients in the combined group had lower contrast load (45% lower on average) and higher air kerma (1.6 times higher on average). The difference in air kerma was due to a higher live fluoroscopy-related exposure.ConclusionsThis study reports the largest pediatric SA cohort analyzed to date and the only one including radiation dose and contrast load. It confirms that pediatric SA is a safe imaging modality with low risk of complications, and demonstrates that SA can be performed in children with low radiation exposure and contrast load.

Combined treatment of hypervascular spinal tumors. Our experience

Objective – to increase the feasibility and safety of surgical treatment and to achieve better clinical outcome in patients with hypervascular spine tumors by combining managed endovascular embolization followed by surgery.Materials and methods. We enrolled 10 patients (6 men and 4 women, the average age was 57 years) with hypervascular spinal tumors who underwent examination and treatment at SO «Scientific-Practical Center of Endovascular Neuroradiology of NAMS of Ukraine» during the period from 2015 to 2019. Five patients have aggressive vertebral hemangiomas (L1, L2, Th12, Th 7, Th 6) and 5 patients have metastases of renal cell carcinoma of the vertebrae (Th4, Th10, Th12, L3) were included. Medical history and neurological status were evaluated, but in all cases the clinical diagnosis was made according to MRI and spine CT. In addition, all patients underwent selective spinal angiography via transfemoral access at the level of the lesion and in at least two adjacent levels. All patients underwent endovascular embolization of the tumor as the first step and open surgery in the volume of biopsy, decompression, and stabilization of the spine in the second stage. The volume of blood loss in ml was estimated by the anesthesiologist.Results. According to the localization of the lesions, spinal angiography showed a high accumulation of contrast fluid in its structure, compared to surrounding tissues, in all cases. This is evidence of the presence of a hypervascular lesion. All patients underwent the combination treatment – preventive endovascular embolization followed by surgery. In 9 cases embolization was performed 24–36 hours before surgery. Due to the patient’s somatic condition, open surgery was delayed once by 5 days. The total embolization of the tumor vasculature in 7 cases was achieved, with a subtotal embolization in 3 cases. Partial embolization was performed in one case of aggressive hemangioma when the afferent was involved in the blood supply of the spinal artery. Reversible deeper neurologic deficits following embolization in 4 cases was observed. Two patients noticed the reduction of the pain immediately after embolization. Mean intraoperative blood loss was 500 ml during the second stage of treatment. Blood loss was 600 ml in the case of delayed surgery. In all cases, the control of bleeding didn’t interrupt adequate decompression and transpedicular stabilization if it was required, and none of the surgical stages were delayed or canceled because of bleeding. Residual bleeding persisted from the venous system and tumor-related tissues.Conclusions. Preoperative embolization of hypervascularized tumors is a safe and effective method to reduce perioperative hemorrhage, which in turn leads to the reduction of the duration of surgery, improves the visualization of the surgical field, allows the performance of all steps of open surgery and achieve a positive clinical result. The mean blood loss was lower compared to procedures without preoperative embolization, according to published papers on surgery of hypervascular spinal tumors. Embolic agents (mixture of Histoacryl and Lipiodol and polyvinyl alcohol (PVA)) have shown high efficacy to control arterial bleeding, with residual bleeding from the venous system.