Standard Fluoroscopy Research Articles

Three-Dimensional Holographic Guidance, Navigation, and Control (3D-GNC) for Endograft Positioning in Porcine Aorta: Feasibility Comparison With 2-Dimensional X-Ray Fluoroscopy

Objectives Intraprocedural deployment of endovascular devices during complex aortic repair with 2-dimensional (2D) x-ray fluoroscopic guidance poses challenges in terms of accurate delivery system positioning and increased risk of x-ray radiation exposure with prolonged fluoroscopy times, particularly in unfavorable anatomy. The objective of this study was to assess feasibility of using an augmented reality (AR) system to position and orient a modified aortic endograft delivery system in comparison with standard fluoroscopy. Materials and Methods The 3-dimensional guidance, navigation, and control (3D-GNC) prototype system was developed for eventual integration with the Intra-Operative Positioning System (IOPS, Centerline Biomedical, Cleveland, OH) to project spatially registered 3D holographic representations of the subject-specific aorta for intraoperative guidance and coupled with an electromagnetically (EM) tracked delivery system for intravascular navigation. Numerical feedback for controlling the endograft landing zone distance and ostial alignment was holographically projected on the operative field. Visualization of the holograms was provided via a commercially available AR headset. A Zenith Spiral-Z AAA limb stent-graft was modified with a scallop, 6 degree-of-freedom EM sensor for tracking, and radiopaque markers for fluoroscopic visualization. In vivo, 10 interventionalists independently positioned and oriented the delivery system to the ostia of renal or visceral branch vessels in anesthetized swine via open femoral artery access using 3D-GNC and standard fluoroscopic guidance. Procedure time, fluoroscopy time, cumulative air kerma, and contrast material volume were recorded for each technique. Positioning and orientation accuracy was determined by measuring the target landing-zone distance error (δLZE) and the scallop-ostium angular alignment error (θSOE) using contrast-enhanced cone beam computed tomography imaging after each positioning for each technique. Mean, standard deviation, and standard error are reported for the performance variables, and Student’s t tests were used to evaluate statistically significant differences in performance mean values of 3D-GNC and fluoroscopy. Results Technical success for the use of 3D-GNC to orient and position the endovascular device at each renal-visceral branch ostium was 100%. 3D-GNC resulted in 56% decrease in procedure time in comparison with standard fluoroscopic guidance (p<0.001). The 3D-GNC system was used without fluoroscopy or contrast-dye administration. Positioning accuracy was comparable for both techniques (p=0.86), while overall orientation accuracy was improved with the 3D-GNC system by 41.5% (p=0.008). Conclusions The holographic 3D-GNC system demonstrated improved accuracy of aortic stent-graft positioning with significant reductions in fluoroscopy time, contrast-dye administration, and procedure time.

A Prospective Comparison of the Effects of Instrument Tracking on Time and Radiation During Minimally Invasive Lumbar Interbody Fusion

Minimally invasive surgical techniques have resulted in improved patient outcomes. One drawback has been the increased reliance on fluoroscopy and subsequent exposure to ionizing radiation. We have previously shown the efficacy of a novel instrument tracking system in cadaveric and preliminary clinical studies for commonplace orthopedic and spine procedures. In the present study, we examined the radiation and operative time using a novel instrument tracking system compared with standard C-arm fluoroscopy for patients undergoing minimally invasive lumbar fusion. The radiation emitted, number of radiographs taken, and time required to complete 2 tasks were recorded between the instrument tracking systems and conventional C-arm fluoroscopy. The studied tasks included placement of the initial dilator through Kambin's triangle during percutaneous lumbar interbody fusion and placement of pedicle screws during both percutaneous lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion with or without instrument tracking. A total of 23 patients were included in the analysis encompassing 31 total levels. For the task of placing the initial dilator into Kambin's triangle, an average of 4.21 minutes (2.4 vs. 6.6 minutes; P= 0.002), 15 fluoroscopic images (5.4 vs. 20.5; P= 0.002), and 8.14 mGy (3.3 vs. 11.4; P= 0.011) were saved by instrument tracking. For pedicle screw insertion, an average of 5.69 minutes (3.97 vs. 9.67; P < 0.001), 14 radiographs (6.53 vs. 20.62; P < 0.001), and 7.89 mGy (2.98 vs. 10.87 mGy; P < 0.001) were saved per screw insertion. Instrument tracking, when used for minimally invasive lumbar fusion, leads to significant reductions in radiation and operative time compared with conventional fluoroscopy.

Collimation Reduces Radiation Exposure to the Surgeon in Endoscopic Spine Surgery: A Prospective Study.

There are no previous studies in the literature comparing the radiation dose to which surgeons are exposed while using a standard fluoroscopy versus collimation during transforaminal percutaneous endoscopic lumbar diskectomy (PELD). The aim of this study is to compare this and to evaluate the effectiveness of collimation in reducing radiation exposure. In this study, the operating surgeon (single surgeon) placed a gamma radiation dosimeter on his chest outside of the lead apron during transforaminal PELD surgeries and measured the radiation exposure immediately after each surgery. As foraminoplasty using free-hand reamers is a longer procedure and requires more fluoroscopy shots, we divided the patients into two groups. The first group consisted of 24 patients (nonforaminoplasty group). The second group consisted of 13 patients (foraminoplasty group). We compared the radiation exposure to the operating surgeon using a standard fluoroscopy versus collimation for each group individually and overall. We randomized the patients within each group based on the order in which they had their respective procedures. We analyzed 39 patients who underwent transforaminal PELD between May and December 2019. In both groups, as well as overall, the recorded radiation exposure to the surgeon was significantly lower in surgeries in which collimation was used. In the first group, the radiation dose was 0.083 versus 0.039 mSv per surgery (p = 0.019), whereas in the second group, it was 0.153 versus 0.041 mSv per surgery (p = 0.001), and overall it was 0.108 versus 0.039 mSv per surgery (p < 0.001). The use of collimation during transforaminal PELD significantly reduces spine the surgeon's exposure to radiation. Therefore, spine surgeons should consider using collimation during transforaminal PELD.

Operative time and learning curve between fluoroscopy-based instrument tracking and robot-assisted instrumentation for patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF)

IntroductionInstrument-navigation modalities including CT-guided and robot-assisted methods claim both efficacy and accuracy when applied to spine surgery, yet often increase setup and operating times which can translate to increased costs. To see the impact of different technologies on surgical efficiency, we studied the impact of a single surgeon’s experience with a multitude of instrument navigational technologies. MethodsConsecutive patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) were analyzed. Consecutive cases were done with assistance of a robot (Mazor, Medtronic, Minneapolis, MN), with the assistance of fluoroscopic instrument-tracking (TrackX, North Carolina, USA), or fluoroscopy alone without adjunctive navigation in consecutive blocks of time. The cases done without assistance were used to normalize for number of interbody implants and decompressions performed as well as hardware removal if needed. Age, body mass index (BMI), sex, operative levels, laminectomy, need for hardware removal, and total operative time were recorded. ResultsA total of 119 cases (74 conventional, 13 robot-assisted, 32 instrument-tracking) were included in analysis. There were no significant differences in age, sex, or BMI between modalities. Average total operative time for robot-assisted, and instrument-tracking-assisted cases was 175.46 ± 46.86 min 119.63 ± 34.33 min, respectively, for each level (p < 0.05 across each group). After normalization against operative times from similar cases performed with conventional fluoroscopy, robotic-navigation added an average of 42.25 ± 28.35 min while use of instrument-tracking saved an average of 13.88 ± 38.69 min. There was no learning curve seen using robotic navigation, as operative times remained consistently longer than similar cases using conventional fluoroscopy and showed no sign of improvement over time. Cases using instrument-tracking were initially slower but trended downwards through approximately 11 patients, at which point operative times were consistently quicker (R2 = 0.39). None of the assisted cases were abandoned in favor of standard fluoroscopy or required hardware revision. ConclusionEnabling technology can have a significant impact on surgical efficiency. Compared to MIS-TLIFs performed with standard fluoroscopy, those done with robotic-assistance consistently negatively impacted operative times while instrument-tracking was associated with a short learning curve and in the majority of cases studied showed improved operative times.

Automated Image Fusion Guidance during Endovascular Aorto-Iliac Procedures: A Randomized Controlled Pilot Study

The benefits of imaging guidance using a new fully automated fusion process (CYDAR) have been demonstrated during endovascular aortic aneurysm repair, but little is known about its use during aorto-iliac occlusive disease endovascular revascularization. The aim of this study was to evaluate the influence of CYDAR image fusion guidance during endovascular treatment of symptomatic aorto-iliac occlusive lesions, compared with control patients treated using standard 2D fluoroscopy alone. This is a single-center randomized controlled pilot study that recruited patients undergoing aorto-iliac endovascular revascularization. Between January 2019 and February 2020, 37 patients with symptomatic aorto-iliac lesions were enrolled: 18 were assigned to the fusion group and 19 to the control group. Patients and lesions characteristics were well balanced between both study groups. The technical success of the procedure was 100% in the Fusion group and 94% in the control group. All radiation-related parameters were lower in the fusion compared to the control group, including: median DAP 18.5 Gy.cm2 vs. 21.8 Gy.cm2; Air Kerma 0.10 Gy vs. 0.12 Gy; fluoroscopy dose 4.2 Gy.cm2 vs. 5.1 Gy.cm2; and number of DSA 7.5 vs. 8. The volume of iodinated contrast used was higher in the fusion group: 41 mL vs. 30 mL. The total procedure time was the same in both groups:60 min vs. 60 min. The results of this pilot study suggest the use of fusion imaging in endovascular treatment of aorto-iliac disease results in reduction in radiation-related measured parameters with no change in procedure time and higher doses of iodinated contrast used. These results need to be further investigated in a larger, adequately powered study.

Intra operative assessment of the coronal balance in spinal deformity surgery : a technical note and retrospective study

Obtaining a spine that is well balanced after fusion for scoliotic deformity is primordial for the patients' quality of life. A simple T-shaped instrument combined with standard intraoperative fluoroscopy can be of great help to evaluate the coronal alignment quickly. The aim of this study was to evaluate if a T-shaped device could predict the postoperative coronal balance. Before finalization of the rod fixation, the balance was checked by verifying the relationship between the T-shaped instrument and the upper instrumented vertebra (UIV), and final adjustments were made to correct the coronal balance. A retrospective study was conducted on 48 patients who underwent surgery to correct scoliotic deformity. Intraoperative and postoperative coronal alignment was measured independently by two observers. The mean intraoperative horizontal offset measured between T-shaped instrument and the center of the UIV was 1,69mm to the right with a standard deviation (SD) of 12,43 mm. On postoperative full spine radiographs, the mean offset between the centra sacral vertical line and the center of the UIV was 2,44mm to the left with a SD of 13,10mm. There is no significant difference in coronal balance between both measurements (p=0,12). With this technique we were able to predict the postoperative coronal balance in all but one patient (97,92%). We conclude that the use of a simple T-shaped instrument can provide adequate intraoperative assessment of coronal balance in correcting scoliotic deformity. Level of evidence : IV - case series.

2-Dimensional Long Film O-Arm Imaging, an Alternative When Intraoperative Fluoroscopy Is Inadequate

Obtaining intraoperative images of the spine in the obese patient and at the cervicothoracic junction have historically been technically difficult due to variable penetration and x-ray scatter. This is particularly true for spinal deformity cases, where clear visualization of the end plates is needed to determine if functional alignment has been restored to the spine. The novel "2D long film" functionality for the Medtronic O-arm is capable of capturing the x-ray backscatter, producing enhanced intraoperative images. Furthermore, images can be obtained along the gantry translation of the O-arm and combined into a single long image, optimizing the workflow of surgeons who use the O-arm for intraoperative navigation. The purpose of this report is to highlight 2 example spinal deformity cases that underscore the utility of this imaging technology. In both cases, standard intraoperative fluoroscopy visualization was unacceptable, so 2D long film images were obtained to assess postcorrection spinal alignment.

Optimizing detection of postoperative leaks on upper gastrointestinal fluoroscopy: a step-by-step guide.

Postoperative leaks after gastrointestinal surgery are important to identify to decrease patient morbidity and mortality. Fluoroscopic studies are commonly employed to detect postoperative leak. While the literature addresses the sensitivity and specificity of these examinations, there is generally a lack of description of the fluoroscopic technique itself and there may be variability between radiologists in how these studies are performed. It is important to balance a standardized fluoroscopy protocol while tailoring the exam for each surgical and patient situation. Here we will briefly review common postoperative anatomy in the upper gastrointestinal tract, propose fluoroscopic techniques to improve postoperative leak detection, and illustrate teaching points with clinical cases.

Technique, Time Demand, Radiation Exposure, and Outcomes of Skin-anchored Intraoperative 3D Navigation in Minimally Invasive Posterior Cervical Laminoforaminotomy.

This was a retrospective review. The objective of this study was to describe our technique and evaluate the time demand, radiation exposure, and outcomes of minimally invasive posterior cervical laminoforaminotomy (MI-PCLF) using skin-anchored intraoperative navigation (ION). Although bone-anchored trackers are most commonly used for ION, a novel technique utilizing noninvasive skin-anchored trackers has recently been described for lumbar surgery and has shown favorable results. There are currently no reports on the use of this technology for cervical surgery. Time demand, radiation exposure, and perioperative outcomes of MI-PCLF using skin-anchored ION were evaluated. Twenty-one patients with 36 operative levels were included. Time for ION setup and operative time were a median of 34 and 62 minutes, respectively. Median radiation to the patient was 2.5 mGy from 10 seconds of fluoroscopy time. Radiation exposure to operating room personnel was negligible because they are behind a protective lead shield during ION image acquisition. There were no intraoperative complications or wrong-level surgeries. One patient required a repeat ION spin, and in 2 patients, ION was abandoned and standard fluoroscopy was used. Skin-anchored ION for MI-PCLF is feasible, safe, and accurate. It results in short operative times, minimal complications, low radiation to the patient, and negligible radiation to operating room personnel.

Data-Driven Deformable 3D-2D Registration for Guiding Neuroelectrode Placement in Deep Brain Stimulation.

Deep brain stimulation is a neurosurgical procedure used in treatment of a growing spectrum of movement disorders. Inaccuracies in electrode placement, however, can result in poor symptom control or adverse effects and confound variability in clinical outcomes. A deformable 3D-2D registration method is presented for high-precision 3D guidance of neuroelectrodes. The approach employs a model-based, deformable algorithm for 3D-2D image registration. Variations in lead design are captured in a parametric 3D model based on a B-spline curve. The registration is solved through iterative optimization of 16 degrees-of-freedom that maximize image similarity between the 2 acquired radiographs and simulated forward projections of the neuroelectrode model. The approach was evaluated in phantom models with respect to pertinent imaging parameters, including view selection and imaging dose. The results demonstrate an accuracy of (0.2 ± 0.2) mm in 3D localization of individual electrodes. The solution was observed to be robust to changes in pertinent imaging parameters, which demonstrate accurate localization with ≥20° view separation and at 1/10th the dose of a standard fluoroscopy frame. The presented approach provides the means for guiding neuroelectrode placement from 2 low-dose radiographic images in a manner that accommodates potential deformations at the target anatomical site. Future work will focus on improving runtime though learning-based initialization, application in reducing reconstruction metal artifacts for 3D verification of placement, and extensive evaluation in clinical data from an IRB study underway.

Scatter radiation reduction with a radiation-absorbing pad in interventional radiology examinations

PurposeRadiation-absorbing pads are an additional possibility to reduce scattered radiation at its source. The goal of this study is to investigate the efficacy of a new reusable radiation-absorbing pad at its origin in an experimental setup. Material and methodsAll measurements were carried out using a clinical angiography system with a standardized fluoroscopy protocol, different C-arm angulations and an anthropomorphic torso phantom as a scattering body. An ionization chamber was used to measure the radiation exposure at five different heights of a simulated operator during a simulated transfemoral angiography intervention. Measurements were carried out with and without radiation-absorbing pads with lead equivalents of 0.25 and 0.5 mm placed onto the scattering body. For all measurements a mobile acrylic shield and an under-table lead curtain was used. ResultsAt all operator heights from 100 to 165 cm a significant radiation dose reduction of up to 80.6 % (p < 0.01) using the radiation-absorbing pad was measured, when compared to no radiation-absorbing pad. At the height of 165 cm the radiation-absorbing pad with a lead equivalence of 0.5 mm showed a significant radiation dose reduction (51.4 %, p < 0.01) in comparison to a lead equivalence of 0.25 mm. ConclusionThe addition of a radiation-absorbing pad to the standard protection means results in a significant dose reduction for the operator, particularly for upper body parts.

P36. Operative time and learning curve between conventional fluoroscopy, fluoroscopy-based instrument navigation, and robot-assisted instrumentation in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF)

BACKGROUND CONTEXT Instrument-navigation modalities including CT-guided and robot-assisted methods claim both efficacy and accuracy when applied to spine surgery, yet often increase setup and operating times. PURPOSE The authors seek to study the impact of multitude of instrument navigational technologies on operative time and the learning curve associated with their use. STUDY DESIGN/SETTING Prospective, single-surgeon, single-institution. PATIENT SAMPLE Patients undergoing minimally invasive transforaminal lumbar interbody fusion with or without decompression, with or without previous hardware removal. OUTCOME MEASURES Total operative time, immediate surgical complications. METHODS Consecutive patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) were analyzed. Two adjunctive technologies were studied and compared with a more conventional fluoroscopic approach without navigation. Consecutive cases were done with assistance of a robot (Mazor Robotics), with the assistance of x-ray tracking (TrackX) or without navigation in three consecutive blocks of time. The cases done without assistance were used to further normalize for number of interbodies and decompressions performed as well as hardware removal if needed. Age, body mass index (BMI), sex, operative levels, laminectomy, need for hardware removal, and total operative time was recorded directly from EPIC. RESULTS A total of 120 cases (74 conventional, 14 robot-assisted, 32 Track-X) were included in analysis. There were no significant differences in age, sex, or BMI between modalities. Uncontrolled, the average operative time for conventional, robot-assisted, and TrackX was 118±36, 157±41, and 107±37 minutes, respectively, for each MIS-TLIF level (p<0.05 across each group). Once normalized for hardware removal, decompression, and number of fusion levels, the robot cases were 24% slower (added 32 minutes/case) while the x-ray tracking cases were 19% faster (subtracted 16 minutes). Operative times in no robot-assisted case were faster than the comparable control procedure, while 69% of those utilizing x-ray tracking were quicker. TrackX cases were initially slower but trended downwards through approximately 11 patients, at which point operative times were consistently quicker (R=0.63). The Mazor cases displayed no learning curve (R=0.08). None of the assisted cases were abandoned in favor of standard fluoroscopy or required hardware revision. CONCLUSIONS Enabling technology can have a significant impact to surgical efficiency. Robotic-assistance consistently negatively impacted operative times, while x-ray tracking was associated with a short learning curve and improved operative times in the vast majority of cases studied. FDA DEVICE/DRUG STATUS TrackX (Approved for this indication) Instrument-navigation modalities including CT-guided and robot-assisted methods claim both efficacy and accuracy when applied to spine surgery, yet often increase setup and operating times. The authors seek to study the impact of multitude of instrument navigational technologies on operative time and the learning curve associated with their use. Prospective, single-surgeon, single-institution. Patients undergoing minimally invasive transforaminal lumbar interbody fusion with or without decompression, with or without previous hardware removal. Total operative time, immediate surgical complications. Consecutive patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) were analyzed. Two adjunctive technologies were studied and compared with a more conventional fluoroscopic approach without navigation. Consecutive cases were done with assistance of a robot (Mazor Robotics), with the assistance of x-ray tracking (TrackX) or without navigation in three consecutive blocks of time. The cases done without assistance were used to further normalize for number of interbodies and decompressions performed as well as hardware removal if needed. Age, body mass index (BMI), sex, operative levels, laminectomy, need for hardware removal, and total operative time was recorded directly from EPIC. A total of 120 cases (74 conventional, 14 robot-assisted, 32 Track-X) were included in analysis. There were no significant differences in age, sex, or BMI between modalities. Uncontrolled, the average operative time for conventional, robot-assisted, and TrackX was 118±36, 157±41, and 107±37 minutes, respectively, for each MIS-TLIF level (p<0.05 across each group). Once normalized for hardware removal, decompression, and number of fusion levels, the robot cases were 24% slower (added 32 minutes/case) while the x-ray tracking cases were 19% faster (subtracted 16 minutes). Operative times in no robot-assisted case were faster than the comparable control procedure, while 69% of those utilizing x-ray tracking were quicker. TrackX cases were initially slower but trended downwards through approximately 11 patients, at which point operative times were consistently quicker (R=0.63). The Mazor cases displayed no learning curve (R=0.08). None of the assisted cases were abandoned in favor of standard fluoroscopy or required hardware revision. Enabling technology can have a significant impact to surgical efficiency. Robotic-assistance consistently negatively impacted operative times, while x-ray tracking was associated with a short learning curve and improved operative times in the vast majority of cases studied.

Use of Standardized Language for C-arm Fluoroscopy Improves Intraoperative Communication and Efficiency.

Intraoperative fluoroscopy is a ubiquitous tool in orthopaedic surgery. However, many orthopaedic surgeons and radiology technologists are not taught standard terminology to communicate with one another. Breakdown of communication leads to inefficiencies. Simulation studies have demonstrated that a common language for C-arm movements may reduce time to capture the desired images and number of radiographs required. Our objective was to investigate the effect of a standardized language protocol for intraoperative C-arm fluoroscopy on communication as perceived by the surgeon and radiology technologists. Our study intervention was the implementation of a common C-arm fluoroscopy terminology education protocol. To evaluate the efficacy of this protocol, a survey was administered to orthopaedic surgeons and radiology technologists after procedures involving the use of intraoperative fluoroscopy. Study end points were measured using a 5-point Likert scale and included effectiveness of communication, need for obtaining repeat radiographs, need to correct the C-arm position, and confusion noted during surgery. This survey was administered before and after the study intervention. The study intervention resulted in a statistically significant improvement in the mean perceived quality of intraoperative communication between the surgeon and the radiology technologist (0.398 [0.072, 0.725], P = 0.017). There was also a reported decrease in confusion in the operating room (-0.572 [-0.880, -0.263], P < 0.001), movement correction of the C-arm fluoroscope (-0.592 [-0.936, -0.248], P = 0.001), and need for repeat radiographs (-0.782 [-1.158, -0.406], P < 0.001) after the implementation of a standardized fluoroscopy language. A standardized fluoroscopy language protocol improves intraoperative communication between orthopaedic surgeons and radiology technologists.

Minimally Invasive Navigated Foraminal Discectomy via Contralateral Approach Using a 3-Dimensional 4K High-Definition Exoscope: 2-Dimensional Operative Video.

This surgical video is the first to demonstrate a novel minimally invasive technique of utilization of surgically navigated foraminal discectomy using a 3-dimensional 4k high-definition exoscope (Sony Olympus). Typical approaches for foraminal disc herniations may involve violation of the facet resulting in subsequent destabilization requiring fusion.1 Although minimally invasive facet-sparing contralateral techniques have previously been described,2 there is continued limitations stemming from rudimentary localization with standard fluoroscopy and impaired visualization with the bulky traditional operative microscope.3 We demonstrate that high-quality real-time navigation is possible using standard Iso-C intraoperative fluoroscopy for 3-dimensional reconstructions, allowing for intraoperative routing. Navigation is particularly advantageous for adjustments in the trajectory of the tubular retractor and for confirmation of complete foraminal decompression. Visualization from the 4k high-definition exoscope also allows for an unparalleled view of the narrow operative corridor and allows for participation from the operative team. Informed consent was obtained from the patient for the surgery in its entirety.

Computed Tomography Guidance for Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia.

Percutaneous glycerol rhizotomy (PGR) is a well-described treatment for trigeminal neuralgia; however, the technique in using surface landmarks and fluoroscopy has not drastically changed since being first introduced. In this paper, we describe a protocol for PGR using computed tomography (CT) guidance based on an experience of over 7 yr and 200 patients. To introduce an approach for PGR using CT guidance and, in doing so, demonstrate possible benefits over the traditional fluoroscopic technique. Using a standard CT scanner, patients are placed supine with head in extension. Barium paste and a CT scout image are used to identify and plan a trajectory to the foramen ovale. A laser localization system built into the CT scanner helps to guide placement of the spinal needle into the foramen ovale. The needle position in the foramen is confirmed with a short-sequence CT scan. CT-guided PGR provides multiple benefits over standard fluoroscopy, including improved visualization of the skull base and significant reduction in radiation exposure to the surgeon and staff. Side benefits include improved procedure efficiency, definitive imaging evidence of correct needle placement, and potentially increased patient safety. We have had no significant complications in over 200 patients. CT-guided PGR is a useful technique for treating trigeminal neuralgia based on better imaging of the skull base, better efficiency of the procedure, and elimination of radiation exposure for the surgeon and staff compared to traditional fluoroscopic based techniques.

Three-Dimensional Holographic Guidance, Navigation, and Control for Endograft Positioning in Porcine Aorta: Feasibility Comparison With Two-Dimensional X-ray Fluoroscopy

Intraprocedural deployment of endovascular devices during complex aortic repair with two-dimensional X-ray fluoroscopy guidance poses challenges in terms of accurate delivery system positioning and increased risk of radiation exposure with prolonged fluoroscopy times, particularly in unfavorable anatomy. The objective of this study was to assess safety, efficiency, and feasibility of using an augmented reality (AR) system to position and orient a modified aortic endograft delivery system in comparison to standard fluoroscopy.

Neuronavigation Assistance. Decreased radiation exposure during spinal surgery in patients with severe combined trauma

Absnract. The results of the study of intraoperative x-ray irradiation of the affected two arrays are presented: the main array using neuronavigation and the control group, where standard 2D fluoroscopy was used. The radiation load on the operating surgeon and auxiliary operating personnel was also evaluated. Intraoperative visualization was carried out using the second-generation iNtellect ENT Navigation rack of the Stryker company (United States of America) for the victims of the main array and the Ziehm Vision RFD optical-optical converter (Germany) of the company for the victims of the control group. The imaging option using an electron-optical transducer is especially important for minimally invasive procedures, where instrumentation is performed percutaneously without direct anatomical control, as opposed to open procedures or working with distorted anatomical structures during injuries. Biplanar fluoroscopy was one of the first intraoperative methods of imaging in real time, and remains one of the leading technologies in orthopedic and spinal surgery. However, radiation exposure from intraoperative fluoroscopy remains a serious problem for patients, surgeons, and operating support staff. The negative effect of ionizing radiation leads to cell damage through the induction of deoxyribonucleic acid and the release of reactive oxygen species. In this regard, cell death or genome instability occurs, which leads to various radiation-related pathologies. It was found that the use of neuronavigation reduces the number of errors, reduces intraoperative trauma, and significantly reduces intraoperative radiation exposure to the injured, operating surgeon and auxiliary operating personnel. The large-scale introduction of navigation technologies will reduce or completely eliminate the harmful effects of ionizing radiation on the injured and medical personnel.

P974Electroanatomical mapping system in atrioventricular nodal reentrant tachycardia: anatomy of koch"s triangle and electrophysiological properties of the slow pathway

Abstract The substrate for atrioventricular nodal reentrant tachycardia (AVNRT) is well established. The standard fluoroscopy and electrogram-guided slow pathway ablation has been widely confirmed as an efficacious technique. The use of non fluoroscopic electroanatomic mapping (NFEM) in AVNRT ablation allows a detailed analysis of the anatomy of Koch’s triangle and distribution of specific electrograms including His bundle electrogram. The analysis of Koch’s triangle dimension and anatomy is still poorly correlated to the electrophysiological properties of the slow pathway and to anthropomorphic characteristics of the patient. Moreover it is not clear if the use of the NFEM leads to a longer procedural time. AIM. The aim of our study was to research the presence of a correlation between Koch’s triangle dimension and anatomy and electrophysiological and anthropomorphic characteristics of the patient. We also evaluate if NFEM prolong total procedural time in ablations performed by "new generation" electrophysiologist (who learned AVNRT ablation in the NFEM era). METHODS. All slow-fast AVRNT ablations executed in 2019 in a single center by two "new generation" electrophysiologist were included. Electrophysiological characteristics of the slow pathway were collected. NavX™ EnSite Precision™ (Abbott, St. Paul, MN, USA) was used in non fluoroscopic procedures to anatomical reconstruction and to analyze Koch’s triangle; distance between effective ablation point and His potential (EA-H), effective ablation point and coronary sinus (EA-CS) and CS dimension were recorded (figure 1). Koch’s triangle area was calculated with Heron’s formula. Total procedural time was recorded to compare fluoroscopic and non fluoroscopic procedures. RESULTS. A total of 13 NavX™ guided zero-fluoroscopy ablation were included. The mean patients age was of 61.6 ± 12.7 years, 61.5% male, with a mean body mass index (BMI) of 26.7 ± 4.8. The mean Koch’s triangle area was of 142.8 ± 68.9 mm, the mean CS area was of 149.2 ± 77.0 mm. A positive correlation was found between EA-H distance and Koch’s triangle area (r= 0.513, p = 0.008) and EA-H distance and BMI (r = 0.683 p &amp;lt; 0.001). Moreover a positive correlation resulted between AH jump (using programmed atrial stimulation) and EA-H distance (r = 0.783, p &amp;lt; 0.001) and AH jump and Koch’s triangle area (r = 0.586, p &amp;lt;0.001). Comparing NavX™ guided ablation and standard ablation in a similar group of patients (mean age of 57.7 ± 11.4 years, 45% male) no difference was found in total procedural time (97.1 ± 30.3 min with NavX vs 96.4 ± 28.1 min with fluoroscopy, p = 0.927). No complication occurred with both technique. CONCLUSION. In our study higher BMI were correlated with larger EA-H distance and larger Koch’s triangle area. Patients with longer AH Jump had larger EA-H distance and larger Koch’s triangle area. The use of NFEM showed to have advantages in terms of anatomical precision and fluoroscopy exposure without prolonging procedural time. Abstract Figure 1

Cryoballoon Pulmonary Vein Isolation and Roof and Posterior Wall Debulking Using Navik 3D™: A New Technique for Atrial Fibrillation Ablation.

The success rates of traditional endocardial ablation techniques for managing atrial fibrillation remain modest. Recently, the performance of posterior wall ablation in conjunction with pulmonary vein (PV) isolation (PVI) has been reported to increase the chance of success following endocardial ablation. We report a systematic approach for the isolation of the PVs and ablation of the left atrial roof and posterior wall using a cryoballoon guided by the novel Navik 3D™ mapping system (APN Health LLC, Waukesha, WI, USA) and offer preliminary data including procedure, fluoroscopy, and cryoablation times for review. Patients (n = 52) aged 63 years ± 10 years with paroxysmal (n = 42), persistent (n = 11), or chronic (n = 2) atrial fibrillation underwent cryoballoon ablation for PVI and/or the left atrial roof, posterior wall, anterior ganglion plexi (GP), or mitral isthmus line. Lesions were accurately delivered to the PVs, left atrial roof, posterior wall, anterior GP, or mitral isthmus line as appropriate. Acute PVI was achieved in 98% of all patients, and eight (15%) required direct current cardioversion to restore sinus rhythm at the end of the procedure. The mean ± standard deviation procedure, fluoroscopy, and cryoballoon ablation times were 149 minutes ± 39 minutes, 33 minutes ± 30 minutes, and 41 minutes ± 14 minutes, respectively. The Navik 3D™ mapping system is believed to be the only available mapping system that allows for the visualization and location of the cryoballoon in three dimensions, enabling the operator to deliver contiguous, overlapping lesions on the roof and posterior wall of the left atrium. It also facilitates precise measurement of the distance between the esophageal temperature probe and the cryoballoon, thereby helping to avoid freezing damage to the esophagus.

Comparing Diagnostic Yield of Electromagnetic Navigational Bronchoscopy Guided With Real Time Cone Beam Computer Tomography Compared to Standard Fluoroscopy Guidance for Peripheral and Central Lung Lesions

Comparing Diagnostic Yield of Electromagnetic Navigational Bronchoscopy Guided With Real Time Cone Beam Computer Tomography Compared to Standard Fluoroscopy Guidance for Peripheral and Central Lung Lesions