Time Trend of the Radiation Exposure Dose in Endoscopic Retrograde Cholangiopancreatography Over an 8-Year Period: A Single-Center Retrospective Study.

INTRODUCTION: The global needs for a reduction in radiation exposure (RE) are increasing. Endoscopic retrograde cholangiopancreatography (ERCP) is a significant fluoroscopic procedure in the gastrointestinal field. However, the actual RE in ERCP and its annual trend are still unclear. Therefore, we examined the yearly trend of RE in ERCP. METHODS: This retrospective, single-center cohort study included consecutive cases of ERCP from September 2012 to June 2019. We measured the air kerma (AK, mGy), dose area product (DAP, Gycm2), and fluoroscopy time (FT, min). We also evaluated the annual trend of the RE before and after the fluoroscopy device update. RESULTS: In total, 2,174 patients receiving ERCP were enrolled. Among these, the mean age was 74.3 years, and 913 patients were women (42.0%). The median/third quartile values of AK (mGy), DAP (Gycm2), and FT (min) were 109/234 mGy, 13.3/25.8 Gycm2, and 18.2/27.7 minutes. The annual AK, DAP, and FT from 2012 to 2019 were 138, 207, 173, 177, 106, 71.0, 45.0, and 33.3 mGy; 23, 21.4, 19, 18.3, 11.9, 9.0, 6.8, and 6.4 Gycm2; and 12.5, 12.1, 9.7, 9.8, 8.2, 10.8, 9.4, and 10.3 minutes, respectively. The corresponding values before and after the update in July 2016 were 177 and 52 mGy (P < 0.0001), 19.2 and 7.6 Gycm2 (P < 0.0001), and 10.2, and 9.9 minutes (P = 0.05), respectively. DISCUSSION: The RE from ERCP tended to decrease every year, especially after fluoroscopy device updates.

European trends in radiology: investigating factors affecting the number of examinations and the effective dose.

The advances in technology have led to a growing trend in population exposure to radiation emerging from the invention of high-dose procedures. It is, for example, estimated that annually 1.2% of cancers are induced by radiological scans in Norway. This study aims to investigate and discuss the frequency and dose trends of radiological examinations in Europe. European Commission (EC) launched projects to gain information for medical exposures in 2004 and 2011. In this study, the European Commission Radiation Protection (RP) reports No. 154 and 180 have been reviewed. The RP 154 countries' data were extracted from both reports, and the average variation trend of the number of examinations and effective doses were studied. According to the results, plain radiography and fluoroscopy witnessed a reduction in the frequency and effective dose per examination. Nevertheless, European collective dose encountered an average increase of 23%, which resulted from a growing tendency for implementation of high-dose procedures such as CT scans and interventional examinations. It is worth noting that most of the CT procedures have undergone an increase in effective dose per examination. Although demand and dose per examination in some radiological procedures (such as intravenous urography (IVU) have been reduced, population collective dose is still rising due to the increasing demand for CT scan procedures. Even though the individual risks are not considerable, it can, in a large scale, threaten the health of the people at the present time. Due to this fact, better justification should be addressed so as to reduce population exposure.

Is There a Relationship Between Body Mass Index and Fluoroscopy Time During Cervical Interlaminar Epidural Steroid Injections?

BACKGROUND: The challenge of obtaining medical imaging in individuals with higher body mass index (BMI) is described, but there is minimal data regarding the relationship between BMI and fluoroscopy time during cervical interlaminar epidural steroid injection (CIESI). OBJECTIVE: To determine the relationship between BMI and fluoroscopy time during CIESI. METHODS: Retrospective cohort study of patients who underwent fluoroscopically guided CIESI between January 2014 and February 2015 at an academic pain medicine center. Fluoroscopy time data were collected. Comparisons based on analysis of variance were made between patients with normal (<25.0 kg/m 2 ), overweight (25.0-29.9 kg/m 2 ), and obese (≥30.0 kg/m 2 ) BMI. RESULTS: Of 399 procedure encounters, 366 had documented BMI and fluoroscopy time data and were included for analysis. Mean age (± SD) in this cohort was 53 ± 13 years, including 189 females (52%) and 205 first-time injections. Mean fluoroscopy time for all injections was 18 ± 10 seconds. Separated by categorical BMI class, the mean fluoroscopy time was 18 ± 9 seconds for normal weight patients, 17 ± 10 seconds for overweight patients, and 20 ± 11 seconds for obese patients, respectively. Post hoc analysis showed that fluoroscopy time was significantly longer only in obese compared with overweight patients ( P = 0.02). Trainee involvement and first-time vs repeat injection did not significantly alter fluoroscopy time ( P = 0.17 and P = 0.12, respectively). CONCLUSIONS: The findings of this study indicate that BMI does not appear to have a clinically significant impact on fluoroscopy time during cervical interlaminar epidural steroid injection procedures. Future study is needed to directly quantify radiation exposure in patients and practitioners, as well as the associated health risk.

Instrumental Assessment of Pediatric Dysphagia.

Speech-language pathologists (SLPs) have fulfilled primary roles in the evaluation and management of children with feeding/swallowing disorders for more than five decades. The increased incidence and prevalence of newborns, infants, and children with feeding and swallowing disorders has resulted in increased use of instrumental swallowing evaluations. The videofluoroscopic swallow study and fiberoptic endoscopic evaluation of swallowing are the two most commonly used swallowing assessments by SLPs, with ultrasound used less frequently. This article focuses on updates over the past decade in the procedures and utility of instrumental assessments of swallowing function, and identifies future directions that may enable us to meet the needs of the children who are in our care to attain functional outcomes.

The evolution of 3D imaging in orthopedic trauma care.

Three-dimensional (3D) imaging can enhance trauma care by allowing better evaluation of bony detail and implant position compared to conventional fluoroscopy or x­ray. Intraoperative 3D imaging further improves this evaluation by allowing any necessary revisions to be made in the operating room prior to the patient emerging from anesthesia. This revision, if necessary, better achieves the surgical goals and alleviates the stressful situation of obtaining postoperative 3D imaging, where the benefit of revision must be balanced against the cost and risk of returning to the operating room. Improved image volume, resolution, and software capability have allowed surgeons to obtain high-quality, wide field views of bony anatomy that can include the uninjured side as a comparison. In this paper, the evolution of intraoperative 3D imaging over the past 25 years is discussed.

Temporal trends of fluoroscopy time and contrast utilization in coronary chronic total occlusion revascularization: insights from a multicenter United States registry.

BACKGROUND: The impact of operator experience on fluoroscopy time and contrast utilization during percutaneous coronary intervention (PCI) of coronary chronic total occlusions (CTOs) has received limited study. METHODS: We evaluated temporal trends in fluoroscopy time and contrast utilization among 1,363 consecutive CTO PCIs performed at three US institutions between January 2006 and November 2011. RESULTS: Mean age was 65 ± 11 years, 85% of patients were men, 40% had diabetes, 37% had prior coronary artery bypass graft surgery, and 42% had prior PCI. The CTO target vessel was the right coronary artery (55%), circumflex (23%), left anterior descending artery (21%), and left main or bypass graft (1%). The retrograde approach was used in 34% of all procedures. The technical and procedural success rates were 85.5 and 84.2%, respectively. The mean procedural time, fluoroscopy time, and contrast utilization were 113 ± 61 min, 42 ± 29 min, and 294 ± 158 mL, respectively. Years since initiation of CTO PCI were independently associated with higher technical success rate (odds ratio [OR] = 1.52, 95% confidence interval [CI] = 1.52-1.70, P < 0.001), lower fluoroscopy time (OR = 0.84, 95% CI = 0.75-0.95, P = 0.005), and contrast utilization (OR = 0.84, 95% CI = 0.62-0.79, P < 0.001) during the study period. CONCLUSIONS: Among selected US-based institutions performing CTO PCI, we observed a significant reduction in total fluoroscopy time and contrast utilization paralleled with an improved technical success rate over time.

Radiation dose of cardiac IVR x-ray systems: a comparison of present and past.

OBJECTIVE: Although many patients benefit greatly from fluoroscopically guided intervention (IVR) procedures such as percutaneous coronary intervention (PCI), one of the major disadvantages associated with these procedures, such as cardiac IVR, is the increased patient radiation dose. This study compared the entrance surface doses of x-ray equipment for cardiac IVR at the same seven cardiac catheterization laboratories between today and the past to determine the radiation doses of current cardiac IVR x-ray systems. METHODS AND RESULTS: This study was conducted in 2001, 2007, and 2014 at the same seven cardiac catheterization laboratories in and around Sendai City, Japan. The entrance surface doses with cineangiography and fluoroscopy were compared in 2001 (11 x-ray systems), 2007, and 2014 (12 x-ray systems) using a 20-cm-thick acrylic plate and skin dose monitor. The x-ray conditions used in the measurements, including the image receptor field magnification mode and the recording speed for cineangiography and fluoroscopy, were those-normally used in the facilities performing PCI. Although presently, the entrance doses of x-ray equipment used for cardiac IVR tend to be lower than previously (fluoroscopy dose in 2001, 19.3 +/- 6.3 mGy/min; in 2014, 13.2 +/- 6.5 mGy/min), some equipment has a high radiation dose. In addition, the dose differences of the x-ray systems in 2014 were greater than those in the past (fluoroscopy dose in 2001, 3.4-fold; in 2014, 10.5-fold). CONCLUSIONS: In IVR procedures, managing the radiation dose of cardiac IVR x-ray systems is a very important issue. Periodical measurement of the radiation dose of the x-ray equipment used for both cineangiography and fluoroscopy for cardiac IVR is necessary.

Exclusion of fluoroscopy use in catheter ablation procedures: six years of experience at a single center.

BACKGROUND: Nonfluoroscopic mapping systems have demonstrated significant reduction of radiation exposure in radiofrequency (RF) catheter ablation procedures. However, their use as only imaging guide is still limited. OBJECTIVE: To evaluate the usefulness of a completely nonfluoroscopic approach to catheter ablation of supraventricular arrhythmias using the Ensite-NavX™ electroanatomical navigation system. METHODS: During 6 years, all consecutive patients referred for RF catheter ablation of regular supraventricular tachycardia (SVT) were admitted for a "zero-fluoroscopy" approach and studied prospectively. The only exclusion criterion was the need to perform a transseptal puncture. RESULTS: A total of 340 procedures were performed on 328 patients (179 men, age 55.7 ± 18.6 years). One hundred fifty-three patients had typical atrial flutter (AFL), 146 had AV nodal reentrant tachycardia (AVNRT), 35 had AV reciprocating tachycardia (AVRT), 4 patients had incisional atrial flutter (IAF), and 2 had focal atrial tachycardia (AT). Procedural success was achieved in 337 of the cases (99.1%). In 322 (94.7%), the procedure was completed without any fluoroscopy use. Mean procedure time was 110.5 ± 51.8 minutes. Mean RF application time was 9.8 ± 12.8 minutes and the number of RF lesions was 16.43 ± 15.8. Only 1 major complication related to vascular access was recorded. During follow-up, there were 12 recurrences (3.5%) (8 patients from the AVNRT group, 4 patients from the AP group). CONCLUSION: RF catheter ablation of SVT with an approach completely guided by the NavX system and without use of fluoroscopy is feasible, safe, and effective.

Future trends in the use of X-ray fluoroscopy for the measurement and modelling of joint motion.

Knowledge of three-dimensional skeletal kinematics during functional activities such as walking, is required for accurate modelling of joint motion and loading, and is important in identifying the effects of injury and disease. For example, accurate measurement of joint kinematics is essential in understanding the pathogenesis of osteoarthritis and its symptoms and for developing strategies to alleviate joint pain. Bi-plane X-ray fluoroscopy has the capacity to accurately and non-invasively measure human joint motion in vivo. Joint kinematics obtained using bi-plane X-ray fluoroscopy will aid in the development of more complex musculoskeletal models, which may be used to assess joint function and disease and plan surgical interventions and post-operative rehabilitation strategies. At present, however, commercial C-arm systems constrain the motion of the subject within the imaging field of view, thus precluding recording of motions such as overground gait. These fluoroscopy systems also operate at low frame rates and therefore cannot accurately capture high-speed joint motion during tasks such as running and throwing. In the future, bi-plane fluoroscopy systems may include computer-controlled tracking for the measurement of joint kinematics over entire cycles of overground gait without constraining motion of the subject. High-speed cameras will facilitate measurement of high-impulse joint motions, and computationally efficient pose-estimation software may provide a fast and fully automated process for quantification of natural joint motion.

Early commercial experience with a newly designed balloon-expandable transcatheter heart valve: 30-day outcomes and implications of preprocedural computed tomography.

OBJECTIVES: We herein report a single-centre experience with the SAPIEN 3 Ultra balloon-expandable transcatheter aortic valve implantation (TAVI) system. METHODS: Between March 2019 and January 2020, a total of 79 consecutive patients received transfemoral TAVI using the SAPIEN 3 Ultra device. Data were retrospectively analysed according to updated Valve Academic Research Consortium-2 definitions. Detailed analysis of multislice computed tomography data was conducted to identify potential predictors for permanent pacemaker (PPM) implantation and residual paravalvular leakage (PVL) post TAVI. RESULTS: Device success and early safety were 97.5% (77/79) and 94.9% (75/79) with resulting transvalvular peak/mean pressure gradients of 21.1 ± 8.2/10.9 ± 4.4 and PVL >mild in 0/79 patients (0%). Mild PVL was seen in 18.9% (15/79) of cases. Thirty-day mortality was 2.5% (2/79). The Valve Academic Research Consortium-2 adjudicated clinical end points disabling stroke, acute kidney injury and myocardial infarction occurred in 1.3% (1/79), 5.1% (4/79) and 0% (0/79) of patients. Postprocedural PPM implantation was necessary in 7.6% (6/79) of patients. Multislice computed tomography analysis revealed significantly higher calcium amounts of the right coronary cusp in patients in need for postprocedural PPM implantation and a higher eccentricity index in patients with postinterventional mild PVL. CONCLUSIONS: First experience with this newly designed balloon-expandable-transcatheter heart valve demonstrates adequate 30-day outcomes and haemodynamic results with low mortality, low rates of PPM implantation and no residual PVL >mild. The herein-presented multislice computed tomography values with an elevated risk for PPM implantation and residual mild PVL may help to further improve outcomes with this particular transcatheter heart valve in TAVI procedures.

Safety of diagnostic spinal angiography in children.

BACKGROUND: Spinal 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. METHODS: This 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. RESULTS: Our 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. CONCLUSIONS: This 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.

Radiation exposure in dialysis access-related procedures decreases with increase in number of procedures performed by the interventional nephrologist.

An appreciation of the inherent risks with radiation exposure to patients and to the physician performing the procedure and the staff is urgently needed. The objective of this study is to assess radiation exposure to both patients and interventional nephrologists performing procedures and see any trends in the procedure and fluoroscopy times over a 2-year period. A total of 400 procedures performed at our vascular access center by a new to practice interventional nephrologist were recorded and retrospectively analyzed. Fluoroscopic time and procedure time for various procedures over the course of 2 years were recorded. This data were subsequently separated into eight groups (four quarters per year) based on the date of the procedure. Our study demonstrates a decrease in mean and median fluoroscopy times and procedure times for newly trained interventional with gain in number of procedures. The mean fluoroscopy time for the first two quarters was 5 minutes and 4 seconds, and the median was 3 minutes and 37 seconds. The mean procedure time for the first two quarters was 38 minutes, and the median was 32 minutes. The mean fluoroscopy time for the last two quarters was 1 minute and 54 seconds, and the median was 1 minute and 26 seconds. The mean procedure time for the last two quarters was 27 minutes, and the median was 21 minutes. In conclusion, gain of experience by the practicing Interventional Nephrologist from performing an increasing number of procedures leads to decreased procedure times and fluoroscopy times, which lowers the risk of radiation.

Role of Robotics in Improving Surgical Outcome in Spinal Pathologies.

BACKGROUND: The desire to improve accuracy and safety and to favor minimally invasive techniques has given rise to spinal robotic surgery, which has seen a steady increase in utilization in the past 2 decades. However, spinal surgery encompasses a large spectrum of operative techniques, and robotic surgery currently remains confined to assistance with the trajectory of pedicle screw insertion, which has been shown to be accurate and safe based on class II and III evidence. The role of robotics in improving surgical outcomes in spinal pathologies is less clear, however. METHODS: This comprehensive review of the literature addresses the role of robotics in surgical outcomes in spinal pathologies with a focus on the various meta-analysis and prospective randomized trials published within the past 10 years in the field. RESULTS: It appears that robotic spinal surgery might be useful for increasing accuracy and safety in spinal instrumentation and allows for a reduction in surgical time and radiation exposure for the patient, medical staff, and operator. CONCLUSION: Robotic assisted surgery may thus open the door to minimally invasive surgery with greater security and confidence. In addition, the use of robotics facilitates tireless repeated movements with higher precision compared with humans. Nevertheless, it is clear that further studies are now necessary to demonstrate the role of this modern tool in cost-effectiveness and in improving clinical outcomes, such as reoperation rates for screw malpositioning.

Efficacy of small-volume gastrografin videofluoroscopic screening for detecting pharyngeal leaks following total laryngectomy.

OBJECTIVES: Pharyngocutaneous fistulae are dreaded complications following total laryngectomy. This paper presents our experience using 3-5 ml gastrografin to detect pharyngeal leaks following total laryngectomy, and compares post-operative videofluoroscopy with clinical follow-up findings in the detection of pharyngocutaneous fistulae. METHODS: A retrospective case-control study was conducted of total laryngectomy patients. The control group (n = 85) was assessed clinically for development of pharyngocutaneous fistulae, while the study group (n = 52) underwent small-volume (3-5 ml) post-operative gastrografin videofluoroscopy. RESULTS: In the control group, 24 of 85 patients (28 per cent) developed pharyngocutaneous fistulae, with 6 requiring surgical correction. In the study group, 24 of 52 patients (46 per cent) had videofluoroscopy-detected pharyngeal leaks; 4 patients (8 per cent) developed pharyngocutaneous fistulae, but all cases resolved following non-surgical management. Patients who underwent videofluoroscopy had a significantly lower risk of developing pharyngocutaneous fistulae; sensitivity and specificity in the detection of pharyngocutaneous fistulae were 58 per cent and 100 per cent respectively. CONCLUSION: Small-volume gastrografin videofluoroscopy reliably identified small pharyngeal leaks. Routine use in total laryngectomy combined with withholding feeds in cases of early leaks may prevent the development of pharyngocutaneous fistulae.

Personal Radiation Protection and Corresponding Dosimetry in Interventional Radiology: An Overview and Future Developments. / Persönliche Strahlenschutzmittel und Dosimetrie des medizinischen Personals in der interventionellen Radiologie: Aktueller Status und neue Entwicklungen.

BACKGROUND: The increasing number of minimally invasive fluoroscopy-guided interventions is likely to result in higher radiation exposure for interventional radiologists and medical staff. Not only the number of procedures but also the complexity of these procedures and therefore the exposure time as well are growing. There are various radiation protection means for protecting medical staff against scatter radiation. This article will provide an overview of the different protection devices, their efficacy in terms of radiation protection and the corresponding dosimetry. METHOD: The following key words were used to search the literature: radiation protection, eye lens dose, radiation exposure in interventional radiology, cataract, cancer risk, dosimetry in interventional radiology, radiation dosimetry. RESULTS AND CONCLUSION: Optimal radiation protection always requires a combination of different radiation protection devices. Radiation protection and monitoring of the head and neck, especially of the eye lenses, is not yet sufficiently accepted and further development is needed in this field. To reduce the risk of cataract, new protection glasses with an integrated dosimeter are to be introduced in clinical routine practice. KEY POINTS: · A combination of personal radiation protection devices and optimized dosimetry improves the safety of medical staff.. CITATION FORMAT: · König AM, Etzel R, Thomas RP et al. Personal Radiation Protection and Corresponding Dosimetry in Interventional Radiology: An Overview and Future Developments. Fortschr Röntgenstr 2019; 191: 512 - 521.

MR-guided direct arthrography of the glenohumeral joint.

AIM: To evaluate the feasibility of magnetic resonance (MR)-guided direct arthrography of the glenohumeral joint with a 1.5 T MR system, performing the entire procedure in a single MR examination. MATERIALS AND METHODS: MR-guided direct arthrography was performed on 11 patients. MR imaging guidance and interactive MR fluoroscopy, with in-room control and display system, were used for needle placement and contrast medium injection. The outcome measures were success or failure of joint puncture, the time taken for introduction of contrast medium, and the diagnostic quality of the subsequent MR arthrography images. RESULTS: Contrast medium was successfully instilled into the joint and diagnostic quality MR arthrography images were obtained in all cases. The median time from initial placement of the skin marker to introduction of the contrast medium was 17 min (range 11-29 min). There were no immediate post-procedure complications. CONCLUSION: Accurate needle placement is feasible in a single MR examination on a commercial 1.5 T closed-bore MR system, using an in-room control and display system together with interactive fluoroscopic imaging, and this was used to provide direct MR arthrography in this study.

The GI fluoroscopy suite in the early twenty-first century.

Since the application of cross-sectional imaging to the examination of the gastrointestinal tract, dramatic changes have occurred in the modern gastrointestinal fluoroscopic suite. Besides the great decrease in use of fluoroscopy, the types of fluoroscopic examinations requested and performed nowadays are different from those of just 2 or 3 decades ago. This paper will review the recent history and the current uses of fluoroscopy in adults at the beginning of the twenty-first century, illustrated by case images and utilization data from a large academic medical center. Fluoroscopy survives because of its unique illustration of motility in real-time, its superior detection and accurate localization of leaks in post-operative patients, and its ability to provide immediate answers and targeted examinations tailored to the individual patient.

Fiberoptic endoscopic evaluation of swallowing.

Fiberoptic endoscopic evaluation of swallowing is a technique that allows for the assessment of pharyngeal dysphagia and the implementation of rehabilitation interventions with the goal of promoting safe and efficient swallowing. An overview of the equipment needed for the laryngoscopic evaluation, how to conduct the examination, what can be visualized endoscopically, diagnostic parameters, the implementation of therapeutic strategies, and suggestions for future research are discussed herein.

Increase in fluoroscopic radiation dose in successive sessions of multistage Onyx embolization of brain arteriovenous malformations compared with the first session.

BACKGROUND AND PURPOSE: Onyx embolization is a treatment for brain arteriovenous malformations (AVMs). However, multistage embolization usually involves the presence of radiodense Onyx cast from the previous sessions, which may influence the fluoroscopic radiation dose. We compared the fluoroscopic dose between the initial and final embolization sessions. MATERIALS AND METHOD: From January 2014 to September 2016, 18 patients underwent multistage Onyx embolization (more than twice) for brain AVMs. The total fluoroscopic duration (minutes), dose-area product (DAP, Gy×cm2), and cumulative air kerma (CAK, mGy) of both the frontal and lateral planes were obtained. We compared the frontal and lateral fluoroscopic dose rates (dose/time) of the final embolization session with those of the initial session. The relationship between the injected Onyx volume and radiation dose was tested. RESULTS: The initial and final procedures on the frontal plane showed significantly different fluoroscopic dose rates (DAP: initial 0.668 Gy×cm2/min, final 0.848 Gy×cm2/min, P=0.02; CAK: initial 12.7 mGy/min, final 23.1 mGy/min, P=0.007). Those on the lateral plane also showed a similar pattern (DAP: initial 0.365 Gy×cm2/min, final 0.519 Gy×cm2/min, P=0.03; CAK: initial 6.2 mGy/min, final 12.9 mGy/min, P=0.01). The correlation between the cumulative Onyx volume (vials) and radiation dose ratio of both planes showed an increasing trend (rho 0.4325-0.7053; P=0.0011-0.0730). CONCLUSION: Owing to the automatic exposure control function during fluoroscopy, successive Onyx embolization procedures increase the fluoroscopic radiation dose in multistage brain AVM embolization because of the presence of radiodense Onyx mass.

Revision Rate of Misplaced Pedicle Screws of the Thoracolumbar Spine-Comparison of Three-Dimensional Fluoroscopy Navigation with Freehand Placement: A Systematic Analysis and Review of the Literature.

BACKGROUND: Recent studies have shown higher accuracy rates of image-guided pedicle screw placement compared to freehand (FH) placement. However, data focusing on the impact of spinal navigation on the rate of revision surgeries caused by misplaced pedicle screws (PS) are scarce. OBJECTIVE: This study is aimed at identifying the rate of revision surgeries for misplaced PS comparing three-dimensional (3D) fluoroscopy navigation (3DFL) with FH PS placement. METHODS: A retrospective analysis was conducted of 2232 patients (mean age, 65.3 ± 13.5 years) with 13,703 implanted PS who underwent instrumentation of the thoracolumbar spine between 2007 and 2015. Group 1 received surgery with use of 3DFL (January 2011 to December 2015), group 2 received surgery in the FH technique (April 2007 to December 2015). Because the use of 3DFL was initiated in January 2011, the examined period for 3DFL-navigated surgeries is shorter. Patients routinely received postoperative computed tomography scans and/or intraoperative control 3D scans. RESULTS: There was an overall rate of revision surgeries for malpositioned PS of 2.9%. In the 3DFL group, the rate of secondary revision surgeries was significantly lower with 1.35% (15/1112 patients) compared to 4.38% (49/1120 patients) in the FH group, respectively (odds ratio, 3.35; P < 0.01). Of all PS in the 3DFL group (30/7548 PS), 0.40% needed revision surgery (P < 0.01) compared to 1.14% in the FH group (70/6155 PS). CONCLUSIONS: We were able to show that the use of 3DFL-navigated PS placement significantly reduces the rate of revision surgeries after posterior spinal instrumentation compared to freehand PS placement.