Fluoroscopic Projections Research Articles

Standard radiographic images in cephalomedullary nailing fixation for intertrochanteric femoral fractures

To review and summarize the projections of radiographic images during cephalomedullary nailing fixation for intertrochanteric femoral fractures, and to propose a set of three projections as standard requirement in immediate postoperative fluoroscopy. Papers on intertrochanteric femoral fractures treated with cephalomedullary nailing fixation that published in a three-year period of 2021-2023 in four leading English orthopedic trauma journals were searched in PubMed. The presented radiographic pictures were identified and scrutinized as whether they were in standard anteroposterior and/or lateral projections of the implanted nails. The nonstandard presence percentage was calculated. Combined with clinical experience, the standard anteroposterior and lateral perspective images of femoral neck, the current situation of radiographic imaging in the operation of cephalomedullary nails, the literature analysis of nonstandard images, the impact of limb rotation on image interpretation, and the characteristics of anteromedial 30° oblique perspective were summarized and analyzed. The presence of nonstandard radiographic pictures is 32.1% in anteroposterior view and 69.2% in lateral view in leading orthopedic trauma journals. In cephalomedullary nailing fixation operation of intertrochanteric femoral fractures, it is reasonable to use the radiographic images of the implanted nails to represent the fractured head-neck, as the head-neck implant (lag screw or helical blade) is aimed to put into centrally in femoral head in lateral projection. Limb rotation or nonstandard projections produced distortion of images, which interfers the surgeons' judgement of fracture reduction quality and the measurement of implant position parameters in femoral head (such as neck-shaft angle and tip-apex distance), and finally lead to a meaningless comparison with the accurate normal value. The 30° anteromedial oblique view from the true lateral (set as 0°) is a tangential projection of the cortices at the anteromedial inferior corner, which gives a clear profile for the determination of cortical apposition status and mechanical support. It is essential to get firstly the true standard lateral fluoroscopy of the nail (shown as a line), then rotate the C-arm to 90° and 30° to get anteroposterior and anteromedial oblique views, and use these three immediate postoperative radiographies as the baseline for evaluation of operative quality and follow-up comparisons. As for real-time monitoring of surgical steps, intraoperative fluoroscopy follows the "Enough is Good" principle, but as for immediate postoperative data storage and basis for operative quality evaluation and baseline for follow-up comparison, it is recommended to obtain a set of three standard radiographic pictures in anteroposterior, true lateral, and 30° anteromedial oblique fluoroscopic projections.

The Importance of Digital Lung Tomosynthesis in Overcoming Computed-Tomography-to-Body Divergence During Bronchoscopic Biopsies of Peripheral Lung Nodules.

The advent of robotic bronchoscopy coupled with electromagnetic navigation bronchoscopy (EMN) and shape-sensing technology have increased diagnostic yields for peripheral pulmonary nodules compared to traditional bronchoscopy. Yet, diagnostic yields from these bronchoscopic platforms still fall short of where they should be. This shortfall is in large part due to a lack of advanced imaging during peripheral bronchoscopy and computed tomography (CT)-to-body divergence (CTBD). Digital lung tomosynthesis (DLT) is an advanced imaging modality that helps overcome CTBD during bronchoscopic biopsies of lung nodules. DLT is a quasi-3D imaging technique, which reconstructs tomographic images of the lung from a series of 2D fluoroscopic projection images. These images can be acquired either using a digital flat panel fluoroscopy machine or a fluoroscopy machine with a more traditional image-intensifier present in most standard bronchoscopy suites. This review aims to explain the mechanisms of both CTBD and DLT to help diagnose early-stage lung cancer more effectively.

Impact of commissural versus coronary alignment on risk of coronary obstruction following transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) with commissural alignment aims to limit the risk of coronary occlusion and maintain good coronary access. However, due to coronary origin eccentricity within the coronary cusp, coronary-commissural overlap (CCO) may still occur. TAVI using coronary alignment, rather than commissural alignment, may further improve coronary access. To compare rates of CCO after TAVI using commissural versus coronary alignment methodology. Cardiac CT scans from 102 patients with severe (tricuspid) aortic stenosis referred for TAVI were analysed. Native cusp asymmetry and coronary eccentricity were defined and used to simulate TAVI using commissural versus coronary alignment. Rates of optimal coronary alignment (< 10° from cusp centre) and severe misalignment (< 15° from coronary-commissural overlap) were compared. Additionally, the impact of valve misalignment during implantation was assessed. The native right coronary artery (RCA) origin was 15.8° (9.5 to 24°) closer to the right coronary cusp/non-coronary cusp (RCC-NCC) commissure than the centre of the right coronary cusp. The native left coronary artery (LCA) origin was 4.5° (0 to 11.5°) closer to the left coronary cusp/non-coronary cusp (LCC-NCC) commissure than the centre of the left coronary cusp (p < 0.01). Compared to commissural alignment, coronary alignment doubled the proportion of optimally-aligned RCAs (62/102 [60.8%] vs. 31/102 [30.4%]; p < 0.001), without a significant change in optimal LCA alignment (62/102 [60.8% vs. 74/102 [72.6%]; p = 0.07). There were no cases of severe misalignment with either strategy. Simulating 15° of valve misalignment resulted in severe RCA compromise risk in 7/102 (6.9%) of commissural alignment cases, compared to none using coronary alignment. Fluoroscopic projection was similar with both approaches. Coronary alignment resulted in a 2-fold increase of optimal TAVI positioning relative to the RCA ostium when compared to commissural alignment without impacting the LCA. Use of coronary alignment rather than commissural alignment may improve coronary access after TAVI and is less sensitive to valve rotational error, particularly for the right coronary artery.

An incremental energy stimulation test to predict success in left bundle branch capture

Abstract Introduction Left bundle branch (LBB) stimulation is guided by fluoroscopic projections and electrocardiographic criteria limited by positional variations. Purpose To evaluate an incremental energy stimulation test (IEST) to optimize success. Methods Prospective, non-randomized experimental study for proof-of-concept analysis (N=23), consisting on: (i) stimulation at three locations at the high, middle and low right mid-ventricular septum (right oblique 30o); and (ii) continuous unipolar stimulation (lumenless fixed helix electrode) at each location with increasing outputs (2 volt x 0.5 ms up to 10 vol x 1.5 ms). The final position for lead penetration was made by the operator blinded to the results of the IEST. Results IEST shortened the S-LVAT (δ-S-LVAT) up to 6.4±5 ms (range 0 to 18 ms), 8±8 ms (range 0 to 36 ms) and 5.5±5 ms (range 0 to 20 ms) respectively for high, mid, and low sites (Figure, panel A and B). There was not observed any paired correlation between the magnitude of the δ-S-LVAT at the three different positions (Pearson 0.36, 0.12 and 0.22; p= 0.1, 0.6 and 0.4 respectively), suggesting that the δ-S-LVAT is site specific. The final position for lead penetration was medium in 17 cases vs low in 6 cases. The low-output S-LVAT interval at the final position before lead penetration was positively correlated with the final S-LVAT achieved after lead penetration (Pearson 0.44; p=0.04), but the magnitude of the correlation increased with the high-output S-LVAT interval (Pearson 0.57; p=0.006) suggesting a better prediction performance (Figure, panel C). A complex relationship was observed where higher δ-S-LVAT values were associated with shorter S-LVAT after penetration and final position of the lead. In fact, for cases with low-output S-LVAT interval &amp;gt; 100 ms, the δ-S-LVAT significantly correlated with S-LVAT after penetration and final position of the lead (Pearson -0.61; p=0.026). Conclusions IEST lead to a site-specific shortening of the S-LVAT, pointing to optimized positions for LBB pacing. The technique provides with additional diagnostic criteria to determine the better site for lead penetration.

Initial validation of a diaphragm tracking system for multiple breath-hold volumetric modulated arc therapy of abdominal tumors: A phantom study.

The breath-hold radiotherapy has been increasingly used to mitigate interfractional and intrafractional breathing impact on treatment planning and beam delivery. Previous techniques include body surface measurements or radiopaque metal markers, each having known disadvantages. We recently proposed a new markerless technique without the disadvantages, where diaphragm was registered between DRR and fluoroscopic x-ray projection images every 180ms during VMAT delivery. An initial validation of the proposed diaphragm tracking system (DiaTrak) was performed using a chest phantom to evaluate its characteristics. Diaphragm registration was performed between DRR and projection streaming kV x-ray images of a chest phantom during VMAT delivery. Streaming data including the projection images and the beam angles were transferred from a linac system to an external PC, where the diaphragm registration accuracy and beam-off latency were measured based on image cross correlation between the DRR and the projection images every 180ms. It was shown that the average of the beam-off latency was 249.5ms and the average of the diaphragm registration error was 0.84mm CONCLUSIONS: Initial validation of the proposed DiaTrak system for multiple breath-hold VMAT of abdominal tumors has been successfully completed with a chest phantom. The resulting beam-off latency and the diaphragm registration error were regarded clinically acceptable.

Transcatheter aortic valve implantation using coplanar and cuspal overlap techniques in Indian patients

IntroductionTranscatheter Aortic Valve Implantation (TAVI) techniques gradually evolved since 2002 and have undergone various refinements. Achieving optimal implantation depth has become crucial for good long term outcome. High implantation decreases the likelihood of conduction disturbances. Conventionally TAVI valve is positioned in a tricusp coplanar (CON) fluoroscopic projection however it does not ensure a optimal implantation. In an attempt to attain higher implantation(3 mm) and decrease rate of permanent pacemaker, cuspal overlap technique (COT) view has been developed. There is scarcity of Indian literature comparing TAVI deployment using coplanar and cuspal overlap techniques. MethodsWe included 111 patients who underwent TAVR with a self-expanding Core Valve Evolut R (Medtronic, Minneapolis, Minnesota), between January 2017 to September 2022 at our centre.Transcatheter Heart Valves (THV) were implanted using the traditional coplanar in 55 patients, while in 56 patients valves were implanted using the COT. ResultsBaseline characteristics including electrocardiographic findings were comparable in both groups. In all patients Evolut R or Evolut PRO valves were used. Procedure was done in conscious sedation in 90.9 % of patients in CON and 96.4 % in COT group. Predilatation and postdilatation was used in 38.8 % vs 33.9 % and 27 % vs 32 % in CON and COT groups respectively. 90 day PPI rate was less in COT group (7.3 % CON vs 3.5 % COP). Majority of patients who received permanent pacemaker implantation (PPI) had baseline ECG abnormality (RBBB in 50 %, LBBB in 16 %, Grade 1 AV block 16 %). Mean time of post procedure PPI was 5.6 days in COT group and 7.3 days in CON group. New onset LBBB was also less in COT group (21 % CON vs 12.5 % COT).There were 3.6 % intraprocedural deaths in CON group and 1.8 % in COT group. Depth of deployed valve was 4.8 ± 2.34 mm in COT and 6.6 ± 2.11 mm in CON group. Valve deployment time was more in COT group(10.40 CON vs 14.34 min COT). Average valve recapture rate was 2.58 in COP and 2.11 in CON. Stroke rate was more in COT group(3.6 % CON vs 7.14 % COT). Pericardial effusions were also more in COT group. All cause mortality at 3 months was 10.9 % in CON group and 5.3 % in COT. ConclusionIn this study we achieved lower rates of PPI and new onset LBBB using COT technique in Indian patients using self-expandable prostheses. However valve deployment time, stroke rate and pericardial effusion were seen more in COT group. All cause mortality was low in cuspal overlap technique.

Role of computed tomography as a preprocedural evaluation tool in transcatheter aortic valve replacement

Abstract Transcatheter aortic valve replacement (TAVR) is increasingly becoming the preferred innovative approach for high-risk aortic stenosis patients. However, before undergoing TAVR, it is crucial to undergo a noninvasive and accurate assessment for proper valve sizing and planning the access route. Computed tomography (CT) imaging plays a vital role in evaluating patients scheduled for transcatheter aortic valve implantation (TAVR). It offers comprehensive information about the aortic valve complex anatomy and the preferred access route, ensuring effective patient selection, and guiding the selection of the appropriate prosthesis. In addition, CT imaging aids in determining the fluoroscopic projection angle, leading to reduced procedural time and optimized use of contrast and radiation exposure.

Murray law-based quantitative flow ratio to assess left main bifurcation stenosis: selecting the angiographic projection matters.

Murray law-based quantitative flow ratio (µQFR) assesses fractional flow reserve (FFR) in bifurcation lesions using a single angiographic view, enhancing the feasibility of analysis; however, accuracy may be compromised in suboptimal angiographic projections. FFRCT is a well-validated non-invasive method measuring FFR from coronary computed tomographic angiography (CCTA). We evaluated the feasibility of µQFR in left main (LM) bifurcations, the impact of the optimal/suboptimal fluoroscopic view with respect to CCTA, and its diagnostic concordance with FFRCT. In 300 patients with three-vessel disease, the values of FFRCT and µQFR were compared at distal LM, proximal left anterior descending artery (pLAD) and circumflex artery (pLCX). The optimal viewing angle of LM bifurcation was defined on CCTA by 3-dimensional coordinates and converted into a 2-dimensional fluoroscopic view. The best fluoroscopic projection was considered the closest angulation to the optimal viewing angle on CCTA. µQFR was successfully computed in 805 projections. In the best projections, µQFR sensitivity was 88.2% (95% CI 76.1-95.6) and 84.8% (71.1-93.7), and specificity was 96.8% (93.8-98.6) and 97.2% (94.4-98.9), in pLAD and pLCX, respectively, with regard to FFRCT. The AUC of µQFR for predicting FFRCT ≤ 0.80 tended to be improved using the best versus suboptimal projections (0.94 vs. 0.89 [p = 0.048] in pLAD; 0.94 vs. 0.88 [p = 0.075] in pLCX). Computation of µQFR in LM bifurcations using a single angiographic view showed high feasibility from post-hoc analysis of coronary angiograms obtained for clinical purposes. The fluoroscopic viewing angle influences the diagnostic performance of physiological assessment using a single angiographic view.

Efficiency of optimal fluoroscopic projection angle defined by computed tomography angiography for left atrial appendage closure

BackgroundLeft atrial appendage (LAA) closure (LAAC) procedures are conventionally performed using empirical fluoroscopic viewing angles. However, because the LAA is a highly variable anatomical structure, these angles cannot depict the LAA in the optimal position. The present study aimed to assess the efficiency of using a novel optimal fluoroscopic projection angle (OPA) for LAAC and to validate its feasibility. MethodsThe OPAs of the derivation cohort were acquired using cardiac computed tomography angiography (CCTA) to assess its superiority for depicting LAA depth versus traditional working angles (TAs) of RAO 30°, CAU 20°. The practicability of OPA-guided LAAC was demonstrated by comparison between clinical data from the validation cohort and those from a propensity-score matched (PSM) control group, as well as randomized controlled studies investigating LAAC. ResultsOf 705 patients in the derivation cohort, the median OPA was RAO 46°, CAU 31°. Compared with TA, the OPA depicted a longer mean (±SD) LAA depth (5.1 ± 4.4) mm and a larger orifice diameter (1.1 ± 1.1 mm), (P < 0.0001 for both). All 38 OPA-guided LAACs were successful, with a shorter mean procedure duration (42.9 ± 12.3 min versus [vs.] 107.2 ± 41.5 min; P < 0.0001) and reduced device consumption (1.08 vs. 1.5 per case), compared with the PSM control group. At the 3-month follow-up, the incidence of peri-device leak was 52.6% (20/38) detected by CCTA, with a mean leakage of 1.6 ± 0.8 mm. ConclusionBy unfolding the LAA depth and orifice diameter for a better view, OPA demonstrated the potential to optimize LAAC procedural efficiency, although further larger-scale studies are required to confirm this.

Intraoperative fluoroscopic safety assessment of femoral head implants with 3-dimensional risk parameters to minimize cut-out.

This study aimed to introduce a method to extract the 3-dimensional spatial position of the femoral head implant from 2-dimensional fluoroscopic projections, allowing surgeons to assess fixation much more accurately and prevent cut-out complications in proximal femoral nailing. To define a safety region for the tip in the femoral head, a novel 3-dimensional distance-based risk parameter called TSD3D was introduced. An intersection algorithm was developed that solely takes the fluoroscopic anteroposterior and lateral distances to reveal the 3-dimensional location of the screw or Kirschner wire tip, enabling the utilization of the 3-dimensional parameter. Orthogonal per- spectives of 6 femur proximal bone substitutes with randomly inserted Kirschner wires were imaged under fluoroscopy. The developed algorithm was used to calculate the implant tip location in 3-dimensional from 2-dimensional images for each case. Algorithm accuracy was validated with the computed tomography-obtained 3-dimensional models of the same femur substitutes. The newly introduced risk parameter successfully visualizes 3-dimensional safety regions. Utilizing the 2-dimensional fluoro- scopic distances as inputs to the algorithm, the 3-dimensional position of the implanted Kirschner wire tip is calculated with a maximum of 9.8% error for a single Cartesian-coordinate measurement comparison. By incorporating the newly introduced 3-dimensional risk parameter, surgeons can more precisely evaluate the position of the implant and avoid cut-out complications, instead of relying solely on misleading 2-dimensional fluoroscopic projections of the femoral head.

Computed tomography to guide transcatheter aortic valve implantation.

Since its introduction in 2022, transcatheter aortic valve implantation (TAVI) has revolutionized the treatment and prognosis of patients with aortic stenosis. Robust clinical trial data and awealth of scientific evidence support its efficacy and safety. One of the key factors for success of the TAVI procedure is careful preprocedural planning using imaging. Computed tomography (CT) has developed into the standard imaging method for comprehensive patient assessment in this context. Suitability of the femoral and iliac arteries for transfemoral access, exact measurement of aortic annulus size and geometry as the basis for prosthesis selection, quantification of the spatial relationship of the coronary ostia to the aortic annular plane, and identification of optimal fluoroscopic projection angles for the implantation procedure are among the most important information that can be gained from preprocedural CT. Further research is aimed at improving risk stratification, for example, with respect to annular perforation, periprosthetic aortic regurgitation, and need for postprocedural implantation of apermanent pacemaker.

Percutaneous pelvic fixation model: an affordable and realistic simulator for pelvic trauma training.

To describe the construction and use of a percutaneous pelvic fixation model, evaluate its translational validity among fellowship-trained orthopedic trauma surgeons, and investigate the importance of specific criteria for effective competency-based assessment of pelvic fixation techniques. Five orthopedic trauma surgeons were asked to place percutaneous wires on a pelvic fixation model, including anterior column (antegrade/retrograde), posterior column (antegrade/retrograde), supra-acetabular, transsacral, and iliosacral. Evaluation criteria included successful wire placement, redirections, cortical breaches, procedure duration, radiation exposure, and quality of fluoroscopic views. Following completion, participants were provided a survey to rate the model. There were no differences between approaches on successful screw placement, wire redirections, or fluoroscopic quality. Antegrade approaches to the anterior and posterior columns took longer (p = 0.008) and used more radiation (p = 0.02). There was also a trend toward more cortical breaches with the antegrade anterior column approach (p = 0.07). Median ratings among surgeons were 4 out of 5 for their overall impression and its accuracy in tactile response, positioning constraints, and fluoroscopic projections. Learning parameters considered most important to the progression of trainees (most to least important) were successful screw placement, corridor breaches, wire redirections, quality of fluoroscopic views, radiation exposure, and procedure duration. In being affordable, accessible, and realistic, this percutaneous pelvic fixation model represents an opportunity to advance orthopedic surgery education globally. Future research is needed to validate the findings of this pilot study and to expand upon how trainees should be evaluated within simulations and the operating room to optimize skill progression.

Use of the iliac-outlet and iliac-inlet combined views in percutaneous posterior column retrograde screw fixation

Posterior column fractures are common acetabular injuries. Although displaced fractures require open reduction and fixation, undisplaced patterns may benefit from percutaneous screw fixation. The combination of iliac oblique with inlet and outlet views offers an intuitive and panoramic rendering of the bony corridor into the posterior column; lateral cross table view completes the sequence of fluoroscopic projections. Herein we describe the use of outlet/inlet iliac views and a detailed procedure for percutaneous retrograde posterior column screw fixation.

The Role of CT-Guided Optimal Fluoroscopic Viewing Angle for Coronary Engagement After TAVR

We report the case of an 89-year-old woman with prior transcatheter aortic valve replacement who underwent successful left coronary artery engagement and left circumflex percutaneous coronary intervention using patient-specific computed tomography fluoroscopic projections. (Level of Difficulty: Advanced.)

A fluoroscopic view for midshaft clavicular fracture reduction and internal fixation: posteroanterior 25° skyline projection

BackgroundOpen reduction and internal fixation have been frequently applied for displaced midshaft clavicular fracture. Plate and screw fixation of clavicular fractures could provide rigid fixation and rotational control. Proper implant positioning in surgical fixation is critical to prevent iatrogenic complications. Fluoroscopy plays an important role in the intraoperative evaluation of implants. This study aimed to introduce a new fluoroscopic projection to evaluate the positioning of plates and screws.MethodsAdult patients with a diagnosis of acute displaced midshaft clavicular fracture were included in this study. The slope angle of the midshaft clavicle was measured on sagittal reconstructions of preoperative computed tomography (CT) scans. The incidence of screw revision based on intraoperative standard posteroanterior (PA) and PA 25° cephalic skyline projections was compared. The interobserver agreement for the two projections was calculated.ResultsTwenty-nine patients with midshaft clavicular fractures were enrolled from January 2020 to June 2021. The PA 25° skyline projection could clearly display the tangential line of the plate and inferior border of the clavicle. The slope angle on the superior surface of the midshaft clavicle was 26.0 ± 5.8° (range: 18.5–38.3°). The incidence of screw revision using the PA projection (72.4%) was significantly different from that using the PA 25° skyline projection (34.5%) (P < 0.05). The concordance of the screw revision rate based on the standard PA and PA 25° skyline projections was strong, with kappa coefficients of 0.680 (95% CI: 0.394–0.968) and 0.776 (95% CI: 0.537–0.998).ConclusionThe PA 25° skyline projection corresponds to the slope angle of the midshaft clavicle. It can provide more accurate information regarding the proper screw length and be applied as a routine method for intraoperative evaluation.

Murray law-based quantitative flow ratio for assessment of left main bifurcation derived from a single fluoroscopic angiographic view as compared to FFRCT

Abstract Background In patients with complex CAD, the presence of left main (LM) disease is an important prognostic factor in assessing the risk balance between PCI and CABG. Functional assessment has become standard of care to evaluate the significance of coronary stenosis and to justify the performance of PCI in the contemporary practice. FFRCT is a well-established method based on 3D reconstruction of coronary artery derived from CCTA. The Murray law-based quantitative flow reserve (μQFR) is a novel computational method of invasive angiography relying on a single angiographic view that takes into account side branches diameters to compute fractal flow division. The aim of the current analysis is to evaluate in patients with complex CAD the feasibility of μQFR in LM bifurcation and its diagnostic concordance with FFRCT. The impact of the optimal viewing angle defined by CCTA on the physiological assessment of the LM bifurcation using a single angiographic view was also evaluated. Methods In 299 consecutive patients with 3-vessel disease with or without LM coronary artery disease, up to 3 analyzable fluoroscopic projections per patient were analysed with μQFR retrospectively. FFRCT and μQFR were measured at 3 fiducial landmark points: i) point of LM bifurcation (POB); ii) proximal LAD 10 mm distal to POB; ii) proximal LCX 10 mm distal to POB. CCTA-based “optimal viewing angle” of LM bifurcation are computed by creating a 3-point closed spline involving the LM, LAD, and LCX at 5mm from the POB and subsequently by reconstructing the “en face” fluoroscopic viewing angle of the spline. The en face viewing angle provides an optimal assessment of the bifurcation geometry [1]. In terms of Rx gantry angulation, the closest angiographic projection to the optimal viewing angle derived from CCTA was defined as the “best fluoroscopic projection” for each patient. Results In 299 patients, 793 projections were analysed with μQFR and compared to FFRCT. Single view μQFR was analyzable in 100%. Correlation and agreement between μQFR and FFRCT for 793 projections in 299 patients are shown in Figure 1A, 2A. The Spearman's correlation coefficient showed moderate correlations at POB (r=0.481, p&amp;lt;0.001) and LCX (r=0.584, p&amp;lt;0.001), and strong correlation at LAD (r=0.642, p&amp;lt;0.001). Correlation and agreement between μQFR and FFRCT for best projections from each patient are shown in Figure 1B, 2B. Correlations were improved in the best projections with the following Spearman's correlation coefficient: at POB (r=0.522, p&amp;lt;0.001), LCX (r=0.622, p&amp;lt;0.001), and LAD (r=0.695, p&amp;lt;0.001). Conclusion Computation of μQFR from a single angiographic view has a high feasibility. Tailored optimal fluoroscopic view is essential for the physiological assessment of the LM bifurcation using a single angiographic view. Evaluation of diagnostic accuracy of μQFR warrants further analysis of the LMCAD after prospective planning of the optimal fluoroscopic view based on the selection of the best CCTA 3D view. Funding Acknowledgement Type of funding sources: None.

Quantification of Commissural Alignment of Balloon-Expandable THV on Fluoroscopy: A Comparison Study With Post-TAVR CT

BackgroundCoronary access may be challenging following transcatheter aortic valve replacement (TAVR) in the setting of transcatheter heart valve (THV) commissural misalignment. ObjectivesThe authors aimed to quantify the degree of commissural alignment following balloon-expandable THV implantation using a fluoroscopy-based trigonometric approach and assess its correlation with post-TAVR computed tomography (CT). MethodsTwenty patients who had undergone both TAVR with the balloon-expandable SAPIEN 3 THV and post-TAVR CT were included in the analysis. Optimized, predeployment 3-cusp angiographic view and postdeployment angiographic view using identical fluoroscopic projections were required. The distance between the most central posterior commissural strut and the THV centerline was assessed. Commissural alignment was calculated by means of a trigonometrical approach using an arcsine function, assuming circular deployment of the THV. Commissural alignment was stratified using a 4-tier scale: aligned (0° to 15°); mildly misaligned (15° to 30°); moderately misaligned (30° to 45°), and severely misaligned (45° to 60°). ResultsSeven patients (35.0%) were misclassified by 1 tier, and no patient was misclassified by 2 or more tiers, with strong agreement between CT and fluoroscopy (weighted Cohen’s kappa coefficient = 0.724). Correlation of the commissural offset angle determined from fluoroscopy and CT was excellent (r = 0.986; 95% CI: 0.965 to 0.995). Bland-Altman analysis demonstrated a strong agreement between both modalities with a mean difference of 0.5° (95% limits of agreement: −12.7° to 13.7°). ConclusionsThe degree of commissural alignment of the balloon-expandable THV can be reliably assessed and quantified on postdeployment fluoroscopy using a standardized 3-cusp view and trigonometry-based analysis.

Real-world experience with the cusp-overlap deployment technique in transcatheter aortic valve replacement: A propensity-matched analysis.

BackgroundThe implantation depth (ID) is a critical condition for optimal hemodynamic and clinical outcomes in transcatheter aortic valve replacement (TAVR). The recently recommended cusp-overlap technique (COT) offers optimized fluoroscopic projections facilitating a precise ID. This single-center observational study aimed to investigate short-term clinical performance, safety, and efficacy outcomes in patients undergoing TAVR with self-expandable prostheses and application of COT in a real-world setting.Materials and methodsFrom September 2020 to April 2021, a total of 170 patients underwent TAVR with self-expandable devices and the application of COT, while 589 patients were treated from January 2016 to August 2020 with a conventional three-cusp coplanar view approach. The final ID and 30-day outcomes were compared after 1:1 propensity score matching, resulting in 150 patients in both cohorts.ResultsThe mean ID was significantly reduced in the COT cohort (−4.2 ± 2.7 vs. −4.9 ± 2.3 mm; p = 0.007) with an improvement of ID symmetry of less than 2 mm difference below the annular plane (47.3 vs. 57.3%; p = 0.083). The rate of new permanent pacemaker implantation (PPI) following TAVR was effectively reduced (8.0 vs. 16.8%; p = 0.028). While the fluoroscopy time decreased (18.4 ± 7.6 vs. 19.8 ± 7.6 min; p = 0.023), the dose area product increased in the COT group (4951 ± 3662 vs. 3875 ± 2775 Gy × cm2; p = 0.005). Patients implanted with COT had a shorter length of in-hospital stay (8.4 ± 4.0 vs. 10.3 ± 6.7 days; p = 0.007).ConclusionTranscatheter aortic valve replacement using the cusp-overlap deployment technique is associated with an optimized implantation depth, leading to fewer permanent conduction disturbances. However, our in-depth analysis showed for the first time an increase of radiation dose due to extreme angulations of the gantry to obtain the cusp-overlap view.

The application of the 150° oblique tangential fluoroscopic view to detect the posterosuperior femoral neck screw in–out–in intraoperatively

This study investigates the application of the 150° tangential fluoroscopic projection as a novel fluoroscopic view to detect the posterosuperior screw in–out–in (IOI) in the cannulated screws fixation of femoral neck fractures. A retrospective analysis was conducted including 33 patients with femoral neck fractures enrolled from April to November 2021. All patients underwent closed reduction and internal fixation with cannulated screws under intra-operative C-arm fluoroscopy. The posterosuperior femoral neck screw position (whether in–out–in and the distance to the femoral neck cortex) was evaluated from the standard anteroposterior (AP), lateral view, and tangential view images. Postoperative computed tomography (CT) scan results are considered the gold standard for detecting the femoral neck screw locations. Of 33 patients, no femoral neck screws were found to be placed IOI under the standard AP and lateral views. The tangential view revealed the posterosuperior screw was IOI in 8 patients, whereas the average distance between the posterosuperior screw and the posterior femoral neck cortex was 2.73 ± 1.06 mm under the standard lateral view. Postoperative CT verified that posterosuperior screw was placed IOI in these 8 patients. In the other 25 patients with the tangential view showed the posterosuperior screw completely contained in the femoral neck, the average distance between the posterosuperior screw and the posterior femoral neck cortex was 5.48 ± 1.26 mm under the standard lateral view and 2.76 ± 1.08 mm under the tangential view, with a statistically significant difference between the two groups (p < 0.05). Post-operative CT demonstrated that the femoral neck screws were completely contained in the femoral neck in these 25 patients. Intra-operative tangential view of 150° can effectively identify the posterosuperior screw IOI in the cannulated screws fixation of femoral neck fractures. Based on our study, we highly recommend the tangential view as a routine intraoperative fluoroscopic angle to detect the posterosuperior screw IOI.

Transcatheter Aortic Valve Replacement Optimization Strategies: Cusp Overlap, Commissural Alignment, Sizing, and Positioning

As transcatheter aortic valve replacement (TAVR) rapidly expands to younger patients and those at low surgical risk, there is a compelling need to identify patients at increased risk of post-procedural complications, such as paravalvular leak, prosthesis–patient mismatch, and conduction abnormalities. This review highlights the incidence and risk factors of these procedural complications, and focuses on novel methods to reduce them by using newer generation transcatheter heart valves and the innovative cusp-overlap technique, which provides optimal fluoroscopic imaging projection to allow for precise implantation depth which minimizes interaction with the conduction system. Preserving coronary access after TAVR is another important consideration in younger patients. This paper reviews the significance of commissural alignment to allow coronary cannulation after TAVR and discusses recently published data on modified delivery techniques to improve commissural alignment.