Comparison of left atrial appendage measurements between conventional transesophageal echocardiography and "Virtual TEE" reconstructed from computed tomography for pre-procedural planning of device closure.

For pre-procedural planning of left atrial appendage (LAA) closure, sizing is crucial. Although transesophageal echocardiography (TEE) is a standard modality, cardiac computed tomography (CT) is also widely used. The virtual TEE (V-TEE) that our group developed enables us to reconstruct images similar to TEE images from CT images. The software should be helpful to understand and plan the procedure strategy. Accordingly, we investigated the utility of V-TEE. Sixty-six patients at 4 participating sites who completed both CT and TEE prior to LAA closure were included. The LAA diameter at the landing zone (LZ) for WATCHMAN™ device implantation was statistically compared at 0°, 45°, 90°, and 135° between V-TEE and TEE. Among 66 cases, only 3 cases were excluded due to poor imaging quality, and 63 cases were analyzed. The device LZ diameters based on V-TEE were strongly correlated with those based on TEE, despite the significantly greater diameter based on V-TEE with mean differences of 2.4 to 3.0 mm (all of them: P < 0.001). The discordances (V-TEE/TEE ratio) at most angles were significantly larger in the elliptical LAAs. V-TEE provides a valuable method for the evaluation of the LAA diameters. V-TEE-based measurements were larger than conventional TEE-based measurements, especially in cases of elliptical LAAs. The assessment by V-TEE has the potential benefit of ensuring proper device sizing regardless of the LAA morphology.

Periprocedural and 30-day outcomes of robotic-assisted percutaneous coronary intervention used in the intravascular imaging guidance.

In recent years, there have been several reports on robotic-assisted percutaneous coronary intervention (R-PCI), but few studies have been conducted on R-PCI performed under intravascular imaging guidance. To elucidate the periprocedural and postoperative 30-day outcomes of intravascular imaging-guided R-PCI, we performed a retrospective observational study on all patients in 102 consecutive cases who underwent R-PCI under intravascular imaging guidance at a single center in Japan from June 12, 2019 to February 18, 2021. The primary end point was 30-day survival, and the secondary end point was the incidence of complications. Intravascular imaging-guided R-PCI was performed 110 times in total on 125 lesions. The medians of procedural time, fluoroscopy time, contrast volume, patient entrance skin dose, and radiation exposure to the main operator were 49 min, 16 min, 67 mL, 0.62 Gy, and 0 µSv, respectively. Furthermore, 60.0% of target lesion branches were American College of Cardiology Foundation/American Heart Association classification type B2 or type C. However, in all cases, lesion dilatation was successful, and the final Thrombolysis in Myocardial Infarction flow grade was 3. The combination of manual operation was required in 12.7% of all cases, but 30-day survival was confirmed in all cases. There were two problems at the puncture site. One small distal branch artery dissection occurred due to manual operation, but no cardiovascular events (myocardial infarction, stroke) occurred and no target lesion restenosis was observed within 30 days of R-PCI. Hence, R-PCI using intravascular imaging demonstrated highly satisfactory treatment outcomes, and no complication caused by robotic operation was observed.

Clinical application of 3D printing technology to the surgical treatment of atlantoaxial subluxation in small breed dogs.

Atlantoaxial instability (AAI)/subluxation commonly occurs in small breed dogs. Ventral stabilization techniques using screws and/or pins and a plate or, more commonly, polymethylmethacrylate are considered to provide the most favorable outcome. However, the implantation of screws of sufficient sizes for long-term stability becomes challenging in toy breed dogs (e.g. <2 kg). We herein report the application of 3D printing technology to implant trajectory planning and implant designing for the surgical management of AAI in 18 dogs. The use of our patient-specific drill guide templates resulted in overall mean screw corridor deviations of less than 1 mm in the atlas and axis, which contributed to avoiding iatrogenic injury to the surrounding structures. The patient-specific titanium plate was effective for stabilizing the AA joint and provided clinical benefits to 83.3% of cases (15/18). Implant failure requiring revision surgery occurred in only one case, and the cause appeared to be related to the suboptimal screw-plate interface. Although further modifications are needed, our study demonstrated the potential of 3D printing technology to be effectively applied to spinal stabilization surgeries for small breed dogs, allowing for the accurate placement of screws and minimizing peri- and postoperative complications, particularly at anatomical locations at which screw corridors are narrow and technically demanding.

3D-computed tomography to compare the dimensions of the left atrial appendage in patients with normal sinus rhythm and those with paroxysmal atrial fibrillation.

Although paroxysmal atrial fibrillation (PAF) is an important cause of cardioembolic stroke, in contrast to chronic AF patients, the anatomical features of the left atrial appendage (LAA) in PAF patients remain unknown. Here, we investigated differences in LAA structures in patients with PAF and those with normal sinus rhythms (NSR) using 3D-computed tomography (3D-CT), which allows us to visualize complicated LAA structures at high spatial resolution. Study subjects were 30 consecutive PAF and 30 NSR patients with complete enhanced cardiac 3D-CT images available. After reconstruction of 3D LAA images, anatomical parameters of the LAA were measured and compared according to three proposed definitions of the LAA orifice plane determined by the following anatomical landmarks: DEF#1, center of warfarin ridge and centerline of proximal left circumflex artery; DEF#2, slope of warfarin ridge and mitral valve annulus; DEF#3, observers' discretion by progressive rotation using the observers' best estimate without the use of landmarks. The LAA volumes of the PAF groups were significantly greater than the NSR group according to all 3 definitions (DEF#1: 1.43 times, DEF#2: 1.44 times, and DEF#3: 1.36 times greater). The LAA orifice area was significantly larger in PAF than in NSR according to DEF#2, but was similar by DEF#1 and DEF#3. Intra-observer and inter-observer variations for any LAA measurements were very low. In conclusion, 3D-CT-based quantitative assessment of the LAA provides highly reproducible and detailed measurements, which can successfully discriminate differences of LAA volume between patients with NSR and those with PAF, suggesting significantly greater volumes in the latter.