Fluoroscopic Navigation Research Articles

Fluoroscopically Guided Acetabular Component Positioning: Does It Reduce the Risk of Malpositioning in Obese Patients?

BackgroundObesity has been described as an independent risk factor for acetabular component malpositioning. The purpose of this study was to determine if this could be overcome by use of fluoroscopic navigation in total hip arthroplasty (THA). MethodsThe first, postoperative, standing, anteroposterior pelvis radiographs from 1599 consecutive patients who underwent fluoroscopic-guided THAs via anterior approach during a six-year period were obtained. We retrospectively reviewed this prospectively collected data. Inclination and anteversion were measured as described by Barrack et al. Intraoperative target ranges for inclination and anteversion angles were 30°-50° and 5°-25°. Patients were divided into 3 cohorts by body mass index, nonobese (<30 kg/m2) obese (between 30 and 40 kg/m2) and morbidly obese (>40 kg/m2), looking for significant differences in acetabular component positioning. ResultsOf the 1599 patients, 1065 were nonobese, 506 obese, and 28 morbidly obese. Overall, average inclination was 37.7° and anteversion was 16.3°. Regarding inclination, 95.0% of cups were positioned in the safe zone, 95.7% for anteversion, and 91.2% for both inclination and anteversion. Analysis of each cohort individually revealed an average inclination of 37.5° in the nonobese, 37.9° in the obese, and 39.9° in the morbidly obese patients. For anteversion, each group's averages were 16.1°, 16.5°, and 16.0°, respectively. There was no significant relationship between a patient's body mass index and cup position for inclination (P = .867), anteversion (P = .673), or both inclination and anteversion (P = .624). ConclusionFluoroscopy is a useful tool for achieving a targeted acetabular component orientation in direct anterior THA, irrespective of patient BMI.

An augmented reality C-arm for intraoperative assessment of the mechanical axis: a preclinical study.

Determination of lower limb alignment is a prerequisite for successful orthopedic surgical treatment. Traditional methods include the electrocautery cord, alignment rod, or axis board which rely solely on C-arm fluoroscopy navigation and are radiation intensive. To assess a new augmented reality technology in determining lower limb alignment. A camera-augmented mobile C-arm (CamC) technology was used to create a panorama image consisting of hip, knee, and ankle X-rays. Twenty-five human cadaver legs were used for validation with random varus or valgus deformations. Five clinicians performed experiments that consisted in achieving acceptable mechanical axis deviation. The applicability of the CamC technology was assessed with direct comparison to ground-truth CT. A t test, Pearson's correlation, and ANOVA were used to determine statistical significance. The value of Pearson's correlation coefficient R was 0.979 which demonstrates a strong positive correlation between the CamC and ground-truth CT data. The analysis of variance produced a p value equal to 0.911 signifying that clinician expertise differences were not significant with regard to the type of system used to assess mechanical axis deviation. All described measurements demonstrated valid measurement of lower limb alignment. With minimal effort, clinicians required only 3 X-ray image acquisitions using the augmented reality technology to achieve reliable mechanical axis deviation.

The Comparison between O-Arm Navigation System and C-Arm Fluoroscopy Navigation System for the Amount of Radiation Exposure in Balloon Kyphoplasty

Introduction Recently, balloon kyphoplasty(BKP) is widely used for osteoporptic vertebral fracture. In this study, we compare the amount of the radiation exposure between O-arm navigation system and C-arm fluoroscopy navigation system in BKP. We consider further review for the radiation exposure in BKP from here on. Material and Methods 63 patients with vertebral fracture is recruited from Kansai Erectronic Power Hospital between March 2011 and June 2014. In all cases, we monitored the amount of radiation exposure by each device. In 63 cases,10 is O-arm navigation system and 53 is C-arm fluoroscopy navigation system. Results The average amount of the radiation exposure is 35.994mGry (range 0.52–97.27) in O-arm and 17.284mGry (range 2.69–86.6) in C-arm. The average radiation time is 35.227 second (range 1.9–57.71) in O-arm and 94.886 second (range 25–319) in C-arm. Conclusion O-arm navigation system use is shorter in radiation time and larger in radiation exposure than C-arm fluoroscopy navigation system. However, the amount of the radiation exposure per unit time in O-arm navigation system is larger than in C-arm fluoroscopy navigation system. We should consider the way to reduce the radiation exposure by stepping down the output power in O-arm.

Accuracy of 3D fluoroscopy-navigated anterior transpedicular screw insertion in the cervical spine: an experimental study

The technique of pedicle screw stabilization is finding increasing popularity for use in the cervical spine. Implementing anterior transpedicular screws (ATPS) in cervical spine offers theoretical advantages compared to posterior stabilization. The goal of the current study was the development of a new setting for navigated insertion of ATPS, combining the advantage of reduced invasiveness of an anterior approach with the technical advantages of navigation. 20 screws were implanted in levels C3 to C6 of four cervical spine models (SAWBONES(®) Cervical Vertebrae with Anterior Ligament) with the use of 3D fluoroscopy navigation system [Arcadis Orbic 3D, Siemens and VectorVision fluoro 3D trauma software (BrainLAB)]. The accuracy of inserted screws was analyzed according to postoperative CT scans and following the modified Gertzbein and Robbins classification. 20 anterior pedicle screws were placed in four human cervical spine models. Of these, eight screws were placed in C3, two screws in C4, six screws in C5, and four screws in C6. 16 of 20 screws (80%) reached a grade 1 level of accuracy according to the modified Gertzbein and Robbins Classification. Three screws (15%) were grade 2, and one screw (5%) was grade 3. Grade 4 and 5 positions were not evident. Summing grades 1 and 2 together as "good" positions, 95% of the screws achieved this level. Only a single screw did not fulfill these criteria. The setting introduced in this study for navigated insertion of ATPS into cervical spine bone models is well implemented and shows excellent results, with an accuracy of 95% (Gertzbein and Robbins grade 2 or better). Thus, this preliminary study represents a prelude to larger studies with larger case numbers on human specimens.

Accuracy of Fluoroscopy versus Computer-Assisted Navigation for the Placement of Anterior Cervical Transpedicle Screws

Accuracy of Fluoroscopy versus Computer-Assisted Navigation for the Placement of Anterior Cervical Transpedicle Screws

Pericardiocentesis guided by echocardiography performed in echocardiography laboratory – Safety profile of the single center prospective registry

IntroductionPericardiocentesis is an invasive procedure for treatment of large pericardial effusion or cardiac tamponade and for diagnostics of pericardial effusion of unknown origin. Fluoroscopy navigation has been the preferred method during the past decades. Nevertheless, new imaging methods such as echocardiography emerged as an alternative guiding method for pericardiocentesis. These methods may improve safety of the procedure. MethodsAll consecutive pericardiocenteses performed in noninvasive cardiology department of a tertiary cardiovascular center during the period between 1998 and 2012 were prospectively recorded. We focused on the procedural safety and procedural success rate. ResultsDuring a 15-year period, 253 pericardiocenteses were performed in 185 patients. Most of the procedures (240 cases) were performed under echocardiographic control in our noninvasive cardiology laboratory under strictly sterile conditions and with equipment for cardiopulmonary resuscitation on site. Etiology of effusion was heart transplantation in 38 patients (25%), postoperative in 20 patients (14%), infective pericarditis in 25 patients (16%), malignancy in 18 patients (12%), and invasive procedures in 19 patients (8%). Apical approach was the most frequent in 218 patients (92%), parasternal in 13 patients (5%) and subxiphoideal in 7 patients (3%). The procedural success rate was 97% overall, with a total complication rate of 3% (2 major complications (0.3%); 7 minor complications (2.7%)). Minor complications included 2 cases of small pneumothorax, 2 cases of pericardial fluid drainage into pleural space, 2 cases of transient right chamber entries, and in 1 case the procedure was complicated by hemopericardium without the need for surgical management. Major complications included 2 cases due to ventricular perforation, one with left ventricule wall laceration in a loculated effusion and one complication due to right ventricular laceration, both resulting in hemopericardium and requiring emergency surgical repair. ConclusionEchocardiography-guided pericardiocentesis performed by echocardiologists in noninvasive cardiology department under strictly sterile conditions and with equipment for cardiopulmonary resuscitation is a safe procedure with infrequent complications. Apical entry site is safe and the dominant approach for pericardiocentesis under echocardiographic navigation.

A New Electromagnetic Navigation System for Pedicle Screws Placement: A Human Cadaver Study at the Lumbar Spine

IntroductionTechnical developments for improving the safety and accuracy of pedicle screw placement play an increasingly important role in spine surgery. In addition to the standard techniques of free-hand placement and fluoroscopic navigation, the rate of complications is reduced by 3D fluoroscopy, cone-beam CT, intraoperative CT/MRI, and various other navigation techniques. Another important aspect that should be emphasized is the reduction of intraoperative radiation exposure for personnel and patient.The aim of this study was to investigate the accuracy of a new navigation system for the spine based on an electromagnetic field.Material and MethodTwenty pedicle screws were placed in the lumbar spine of human cadavers using EMF navigation. Navigation was based on data from a preoperative thin-slice CT scan. The cadavers were positioned on a special field generator and the system was matched using a patient tracker on the spinous process. Navigation was conducted using especially developed instruments that can be tracked in the electromagnetic field. Another thin-slice CT scan was made postoperatively to assess the result. The evaluation included the position of the screws in the direction of trajectory and any injury to the surrounding cortical bone. The results were classified in 5 groups: grade 1: ideal screw position in the center of the pedicle with no cortical bone injury; grade 2: acceptable screw position, cortical bone injury with cortical penetration ≤ 2 mm; grade 3: cortical bone injury with cortical penetration 2,1-4 mm, grad 4: cortical bone injury with cortical penetration 4,1-6 mm, grade 5: cortical bone injury with cortical penetration >6 mm.ResultsThe initial evaluation of the system showed good accuracy for the lumbar spine (65% grade 1, 20% grade 2, 15% grade 3, 0% grade 4, 0% grade 5). A comparison of the initial results with other navigation techniques in literature (CT navigation, 2D fluoroscopic navigation) shows that the accuracy of this system is comparable.ConclusionEMF navigation offers a high accuracy in Pedicle screw placement with additional advantages compared to other techniques. The short set-up time and easy handling of EMF navigation should be emphasized. Additional advantages are the absence of intraoperative radiation exposure for the operator and surgical team in the current set-up and the operator’s free mobility without interfering with navigation. Further studies with navigation at higher levels of the spine, larger numbers of cases and studies with control group are planned.

The accuracy of 3D fluoroscopy-navigated screw insertion in the upper and subaxial cervical spine.

Due to better primary stability and repositioning options, pedicle screws are increasingly used during posterior stabilization of the cervical spine. However, the serious risks generally associated with the insertion of screws in the cervical spine remain. The purpose of this study is to examine the accuracy of pedicle screw insertion with the use of 3D fluoroscopy navigation systems, also accounting for various spine levels. Data of 64 patients were collected during and after screw implantation (axial and subaxial) in the cervical spine. 207 screws were implanted from C1 to C7 and analyzed for placement accuracy according to postoperative CT scans and following the modified Gertzbein and Robbins classification. The accuracy of most of the inserted screws was assessed as grade 2 according to the modified Gertzbein and Robbins classification. 93.9% of the screws implanted at C1 or C2, and 78.51% of the screws implanted at levels C3-C7 showed placement accuracy grade 2 or better, indicating pedicle wall perforation of <2 mm. Overall, seven complications were observed. In three cases, the vertebral artery was affected, leading to one fatality. Surgical revision was necessary once because of Magerl screw misplacement and three times due to impaired wound healing. No radicular symptoms resulted from screw malposition. Axial and subaxial screws can be inserted with a high grade of accuracy using 3D fluoroscopy-based navigation systems. Nevertheless, while this useful innovation helps to minimize the risks of misplacement, the surgery is still a challenge, as arising complications remain severe.

Urgent endovascular repair for ruptured aortic aneurysm using computed tomography image fusion

Abdominal aortic aneurysm rupture remains a cardiovascular catastrophe with strikingly high morbidity and mortality rates. Endovascular aneurysm repair management has recently emerged as a valuable treatment modality for ruptured abdominal aortic aneurysm, but better outcomes have to be reached. Image fusion may potentially improve perioperative outcomes in selected patients, guiding navigation and device implantation and limiting contrast dosage during interventions. We report an 83-year-old man presenting with an 80-mm infrarenal aortic aneurysm rupture suitable for endovascular aneurysm repair. Endovascular navigation and stent graft deployment were achieved using computed tomography image fusion for the first reported case in English.

THE UTILITY OF 3-DIMENSIONAL-NAVIGATION IN THE SURGICAL TREATMENT OF CHILDREN WITH IDIOPATHIC SCOLIOSIS

Objective. To evaluate the accuracy of screw placement using preoperative 3D CT-based navigation with intraoperative fluoroscopic guidance compared with freehand placement. Material and Methods . Intraoperative registration of patient anatomy to preoperative 3D-CT using anatomic landmarks was performed in 62 patients aged 12-18 years with mean deformity 67° (range, 52° to 80°). When registration accuracy was high, screw tracts were drilled under navigation guidance. When the error was &gt;1.0 mm, registration was performed using posterior vertebral bone structures. The times required for tracker placement, registration, and screw track formation, as well as the number of passes were documented. Results were compared with outcomes in cases operated on with freehand screw placement. Results . In the navigation group, 710 pedicle screws were placed. Mean times were 55 seconds for tracker placement, 94.5 seconds per vertebra for patient registration, 131.1 seconds for screw tract formation on the concave side of the deformity, and 129.5 seconds on the convex side. In the freehand group, 470 pedicle screws were placed. Average time for screw placement was 135.2 seconds, pedicle integrity was breached in 5.1 % of trajectories. Conclusion . Intraoperative optic fluoroscopic navigation based on anatomic landmark registration to preoperative 3D-CT spine images enables precise pedicle screw placement.

Bronchoscopic Diagnosis of Solitary Pulmonary Nodules with the Use of NIR Spectroscopy

Background: Recently, SPN has become a much more frequently encountered issue in bronchology. Efficient and reliable guidance method for SPN morphological proof is highly needed. Objectives: The aim of study was to compare the diagnostic values of NIR (near infrared) spectroscopy with EBUS for SPN diagnostic. Fluoroscopic guidance with TBB and needle biopsy were done in all patients. Methods: In our study, we used two types of monitoring systems. Fluoroscopic guidance was combined with either a radial EBUS or a NIR spectroscopy probe for tissue confirmation. 139 male and 71 female patients, having a medial age of 68 years with CT/PET findings of metabolically active SPN were examined between 2/2010 and 2/2013. We designed an instrument for measurement of the penetration of the NIR through lung tissue. Indicating and source fibers were navigated towards the SPN. An EBUS radial probe was used, during fluoroscopic navigation. Results: The statistical analysis of the results obtained showed a comparative specificity and sensitivity of the NIR spectroscopy, with radial EBUS. Conclusions: NIR spectroscopy produced similar efficacies as the radial EBUS. However, the number of positive biopsies was more dependent upon the ability to direct the confirmatory device to the SPN during fluoroscopic guidance than on the type of the device.

Multimodal angiographic assessment of cerebral arteriovenous malformations: a pilot study

PurposeWe describe our protocol of three-dimensional (3D) Roadmap intracranial navigation and image fusion for analysis of the angioarchitecture and endovascular treatment of brain arteriovenous malformations (AVMs).MethodsWe performed superselective catheterization of...

The Utility of 3-Dimensional-Navigation in the Surgical Treatment of Children With Idiopathic Scoliosis

Study DesignAmbispective study of patients undergoing surgical correction of adolescent idiopathic scoliosis. ObjectiveTo evaluate the accuracy of screw placement using preoperative 3-dimensional (3D) computed tomography (CT)-based navigation with intraoperative fluoroscopic guidance compared with freehand placement. Summary of Background DataPedicle screws placed in deformed vertebrae have a high malposition rate. The use of navigation-based systems has increased placement accuracy. MethodsIntraoperative registration of patient anatomy to preoperative 3D-CT was performed using anatomic landmarks. When registration accuracy was high (mean square error, <1.0 mm), screw tracts were drilled under navigation guidance; when the error was >1.0 mm, re-registration was performed. The researchers documented times for registration, navigation, and screw placement, and the number of passes. Results were compared with outcomes in cases operated on with freehand screw placement. ResultsA total of 62 patients were included (54 females and 8 males; mean age was 15.1 years [range, 12–18 years]). Mean deformity was 67° (range, 52° to 80°). Mean follow-up was 35 months (range, 42–19 months). In the navigation group, 710 pedicle screws were placed. Mean times were 55 seconds for tracker placement, 94.5 seconds per vertebra for patient registration, 131.1 seconds for screw tract formation on the concave side of the deformity, and 129.5 seconds on the convex side. Average total procedure time was 3.5 hours (range, 2–7 hours). Mean overall registration accuracy was 0.7 mm. Pedicle integrity was breached in 1.6% trajectories. In the freehand group, 470 pedicle screws were placed. Average time for screw placement was 135.2 seconds (p < .001 vs. navigation). Pedicle integrity was breached in 5.1% of trajectories (p < .0001 vs. navigation). No patient developed neurological or other complications. There was no destabilization of the instrumented spine during short- or long-term follow-up. ConclusionsIntraoperative optic fluoroscopic navigation based on anatomic landmark registration to preoperative 3D-CT spine images enables precise pedicle screw placement with only a minor increase in pedicle preparation time in patients with adolescent idiopathic scoliosis.

Iliosacral screw insertion using CT-3D-fluoroscopy matching navigation

BackgroundPercutaneous iliosacral screw insertion requires substantial experience and detailed anatomical knowledge to find the proper entry point and trajectory even with the use of a navigation system. Our hypothesis was that three-dimensional (3D) fluoroscopic navigation combined with a preoperative computed tomography (CT)-based plan could enable surgeons to perform safe and reliable iliosacral screw insertion. The purpose of the current study is two-fold: (1) to demonstrate the navigation accuracy for sacral fractures and sacroiliac dislocations on widely displaced cadaveric pelves; and (2) to report the technical and clinical aspects of percutaneous iliosacral screw insertion using the CT-3D-fluoroscopy matching navigation system. MethodsWe simulated three types of posterior pelvic ring disruptions with vertical displacements of 0, 1, 2 and 3cm using cadaveric pelvic rings. A total of six fiducial markers were fixed to the anterior surface of the sacrum. Target registration error over the sacrum was assessed with the fluoroscopic imaging centre on the second sacral vertebral body. Six patients with pelvic ring fractures underwent percutaneous iliosacral screw placement using the CT-3D-fluoroscopy matching navigation. Three pelvic ring fractures were classified as type B2 and three were classified as type C1 according to the AO-OTA classification. Iliosacral screws for the S1 and S2 vertebra were inserted. ResultsThe mean target registration error over the sacrum was 1.2mm (0.5–1.9mm) in the experimental study. Fracture type and amount of vertical displacement did not affect the target registration error. All 12 screws were positioned correctly in the clinical series. There were no postoperative complications including nerve palsy. The mean deviation between the planned and the inserted screw position was 2.5mm at the screw entry point, 1.8mm at the area around the nerve root tunnels and 2.2mm at the tip of the screw. ConclusionThe CT-3D-fluoroscopy matching navigation system was accurate and robust regardless of pelvic ring fracture type and fragment displacement. Percutaneous iliosacral screw insertion with the navigation system is clinically feasible.

The accuracy of pedicle screw placement using intraoperative image guidance systems

Several retrospective studies have demonstrated higher accuracy rates and increased safety for navigated pedicle screw placement than for free-hand techniques; however, the accuracy differences between navigation systems has not been extensively studied. In some instances, 3D fluoroscopic navigation methods have been reported to not be more accurate than 2D navigation methods for pedicle screw placement. The authors of this study endeavored to identify if 3D fluoroscopic navigation methods resulted in a higher placement accuracy of pedicle screws. A systematic analysis was conducted to examine pedicle screw insertion accuracy based on the use of 2D, 3D, and conventional fluoroscopic image guidance systems. A PubMed and MEDLINE database search was conducted to review the published literature that focused on the accuracy of pedicle screw placement using intraoperative, real-time fluoroscopic image guidance in spine fusion surgeries. The pedicle screw accuracy rates were segregated according to spinal level because each spinal region has individual anatomical and morphological variations. Descriptive statistics were used to compare the pedicle screw insertion accuracy rate differences among the navigation methods. A total of 30 studies were included in the analysis. The data were abstracted and analyzed for the following groups: 12 data sets that used conventional fluoroscopy, 8 data sets that used 2D fluoroscopic navigation, and 20 data sets that used 3D fluoroscopic navigation. These studies included 1973 patients in whom 9310 pedicle screws were inserted. With conventional fluoroscopy, 2532 of 3719 screws were inserted accurately (68.1% accuracy); with 2D fluoroscopic navigation, 1031 of 1223 screws were inserted accurately (84.3% accuracy); and with 3D fluoroscopic navigation, 4170 of 4368 screws were inserted accurately (95.5% accuracy). The accuracy rates when 3D was compared with 2D fluoroscopic navigation were also consistently higher throughout all individual spinal levels. Three-dimensional fluoroscopic image guidance systems demonstrated a significantly higher pedicle screw placement accuracy than conventional fluoroscopy or 2D fluoroscopic image guidance methods.

CT-3D-Fluoroscopy Matching Navigation Can Reduce the Malposition Rate of Iliosacral Screw Insertion for Less-Experienced Surgeons

The aim of the present study was to determine whether 3-dimensional (3D) fluoroscopic navigation combined with a preoperative computer tomography (CT)-based plan could enable surgeons to perform safe and reliable iliosacral screw insertion despite their limited experience. Eight pelvises with surrounding soft tissue donated from embalmed cadavers were used. Kirschner wires with a diameter of 3 mm were placed across the ilia bilaterally into the S1 and S2 vertebrae by 4 orthopaedic trainees. In 4 specimens, wires were placed across the right ilium using conventional technique and the left ilium using the CT-3D-fluoroscopy matching navigation system. In 4 other specimens, wires were placed across the right ilium using the 3D-fluoroscopic navigation system and the left ilium using the CT-3D-fluoroscopy matching navigation system. A postoperative CT-based analysis of wire localization was performed. The number of wire insertions until the final position check, operation duration, and radiation time and dose were also evaluated. The percentage of wires inserted correctly was higher in the CT-3D-fluoroscopy matching navigated group (100%) than in the conventional technique group (50%) and 3D-fluoroscopic navigation group (50%). The number of wire insertions and radiation time were significantly lower with both navigation systems than with the conventional technique, whereas there was no significant difference between the navigation systems. There were no significant differences in operation time and radiation dose among the 3 groups. The CT-3D-fluoroscopy matching navigation system reduced the malposition rate of percutaneous iliosacral screw insertion when performed by less experienced surgeons.

Clinical outcome of anatomic double-bundle ACL reconstruction and 3D CT model-based validation of femoral socket aperture position

The purpose of this study was to evaluate the clinical results of anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction in which anatomic position of femoral socket apertures was validated using three-dimensional (3D) computed tomography (CT) modelling. Anatomic DB ACL reconstructions with hamstring autografts were performed in 34 patients. Two femoral sockets were created through a far anteromedial (AM) portal behind the lateral intercondylar ridge with the assistance of intraoperative 3D fluoroscopic navigation. Femoral tunnel aperture positioning was investigated postoperatively using 3D CT images in all patients. Clinical results were also evaluated subjectively and objectively at least up to 2 years. Measurement of the AM and the posterolateral (PL) femoral socket locations on the 3D CT images using the quadrant method showed that the centre of the AM socket aperture was located at a depth of 21.0 ± 4.1% and a height of 30.5 ± 9.3% and that of the PL socket aperture was located at a depth of 31.3 ± 5.8% and a height of 57.2 ± 7.7%. The femoral socket locations were considered as anatomic in accordance with previous cadaveric studies examining the positions of ACL femoral insertion site. Subjectively, the mean Lysholm score was 96.9 ± 4.0 points. According to IKDC final objective scores, 26 knees (76%) were objectively graded as normal, 8 (24%) as nearly normal, and 0 (0%) as abnormal or severely abnormal. Postoperative side-to-side anterior translation measured with a KT-2000 arthrometer averaged 0.7 ± 1.2 mm. DB ACL reconstructions in which femoral socket apertures were validated anatomically using 3D CT provided satisfactory short-term results. Case series, Level IV.

Implementation of real‐time three‐dimensional transesophageal echocardiography for mitral balloon valvuloplasty

Transthoracic (TTE) and intracardiac echocardiography (ICE) have both been established as modalities for imaging guidance in mitral balloon valvuloplasty (MBV). Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) improves depth resolution, characterization of pathology and visualization of interventional catheters and devices. Three-dimensional imaging should enhance catheter navigation but improvements in procedural outcomes are not easily quantified. Using time from transseptal puncture to balloon inflation, procedure time and radiation exposure as surrogates for improvements linked to image guidance, we describe our early experience in implementing RT3D-TEE during MBV, a prototypical left-sided structural intervention. Using a dedicated interventional procedures database, we reviewed the clinical and procedural variables of 70 consecutive cases of MBV utilizing either RT3D-TEE or TTE combined with ICE from 12/2004 to 4/2009. The clinical characteristics of both groups were well matched and there was no difference in mean gradient reduction or complication rates. Fluoroscopy times (TTE/ICE 26.7 ± 5.6 min. vs. RT3D-TEE 23.3 ± 6 min. P = 0.02) and radiation dose-area product (TTE/ICE 216.2 ± 96.6 vs. RT3D-TEE 171.5 ± 63.9) were lower with the RT3D-TEE cohort. Time from 1st transseptal puncture attempt to 1st balloon inflation was found to be lower in the RT-3DTEE cohort (TTE/ICE 36 ± 8 min vs. 28 ± 8 min P <0.01) CONCLUSION: RT3D-TEE is associated with expedited transseptal puncture and balloon catheter navigation as reflected in the decreased transseptal to balloon time. RT3D-TEE is associated with less reliance on fluoroscopic navigation as compared to using TTE/ICE. This series demonstrates the feasibility and advantages of implementing RT3D-TEE for MBV.

An evaluation of three-dimensional image–guided technologies in percutaneous pelvic and acetabular lag screw placement

BackgroundPercutaneous stabilization using three-dimensional (3D) navigation system is a promising treatment for pelvic and acetabular fractures. However, there are still some controversies regarding the use of 3D navigation to treat pelvic and acetabular fractures. The purpose of this study was to compare the Iso-C3D fluoroscopic navigation, standard fluoroscopy, and two-dimensional (2D) fluoroscopic navigation in placing percutaneous lag screws in pelvic specimens to better understand the merits of 3D navigation techniques. MethodsFifty-four instrumentation procedures were performed in this study using six cadaveric pelvic specimens. Three groups were designated for different procedures and tests: group I, standard fluoroscopy; group II, 2D fluoroscopic navigation; and group III, Iso-C3D fluoroscopic navigation. Nine screws were placed in each pelvis, including four screws placed bilaterally through the ilium into S1 and S2 vertebrae, four screws placed bilaterally through anterior and posterior columns of acetabulum, and one screw placed through the pubic symphysis. 3D fluoroscopic techniques were evaluated to determine the accuracy of screw position, instrumentation time, and fluoroscopic time. The data were statistically analyzed using SPSS 13.0. ResultsThe malposition rate was 38.89%, 22.22%, and 0% in standard fluoroscopy, 2D fluoroscopic navigation, and Iso-C3D fluoroscopic navigation groups, respectively. There was no significant difference between standard fluoroscopy and 2D fluoroscopic navigation. Compared with Iso-C3D fluoroscopic navigation, there were significant differences (analysis of variance [ANOVA], P < 0.05). The mean instrumentation operating time using Iso-C3D fluoroscopic navigation technique was 15.4 ± 4.5 min. There were significant differences compared with standard fluoroscopy (31.5 ± 6.2 min) and 2D fluoroscopic navigation (26.3 ± 7.5 min; ANOVA, post hoc Scheffe, P < 0.01). The mean fluoroscopic time of Iso-C3D fluoroscopic navigation was 66 ± 4.8 min. Compared with standard fluoroscopy (132.8 ± 7.3 min) and 2D fluoroscopic navigation (47.7 ± 5.6 min), there were significant differences (ANOVA, post hoc least significant difference, P < 0.01). ConclusionsIn the present study, we compared Iso-C3D fluoroscopic navigation, 2D fluoroscopic navigation, and standard fluoroscopy. Iso-C3D fluoroscopic navigation showed a higher accuracy rate in positioning and a shorter instrumentation operating time. The fluoroscopic time was longer in Iso-C3D fluoroscopic navigation than that in standard fluoroscopy, indicating that radiation exposure can be moderately reduced in Iso-C3D fluoroscopic navigation operation, although the fluoroscopic time was the shortest in 2D fluoroscopic navigation.

Radiofrequency ablation for treatment for osteoid osteoma of the scapula using a new three-dimensional fluoroscopic navigation system

Osteoid osteoma is a relatively common benign skeletal tumor. The traditional standard treatment has been surgical resection of the nidus. Recently, computed tomography (CT)-guided radiofrequency ablation (RFA) has gained favor as a more precise alternative due to potentially less bone destruction. However, CT-guided RFA is limited in treatment for osteoid osteoma involving complex anatomic structures such as cervical spine, pelvis, or scapula because of difficulty in approach and proximity to neurovascular structures. To solve this problem, we investigated RFA using a new real-time three-dimensional fluoroscopic navigation system. We report its technical procedure and use in a rare case of osteoid osteoma of the scapula.