A new ring fixator system for automated bone fixation.

BACKGROUND: In the field of orthopaedics, external fixators are commonly employed for treating extremity fractures and deformities. Computer-assisted systems offer a promising and less error-prone treatment alternative to manual fixation by utilising a software to plan treatments based on radiological and clinical data. Nevertheless, existing computer-assisted systems have limitations and constraints. METHODS: This work represents the culmination of a project aimed at developing a new automatised fixation system and a corresponding software to minimise human intervention and associated errors, and the developed system incorporates enhanced functionalities and has fewer constraints compared to existing systems. RESULTS: The automatised fixation system and its graphical user interface (GUI) demonstrate promising results in terms of accuracy, efficiency, and reliability. CONCLUSION: The developed fixation system and its accompanying GUI represent an improvement in computer-assisted fixation systems. Future research may focus on further refining the system and conducting clinical trials.

A haptic guidance system for simulated catheter navigation with different kinaesthetic feedback profiles.

BACKGROUND: This paper proposes a haptic guidance system to improve catheter navigation within a simulated environment. METHODS: Three force profiles were constructed to evaluate the system: collision prevention; centreline navigation; and a novel force profile of reinforcement learning (RL). All force profiles were evaluated from the left common iliac to the right atrium. RESULTS: Our findings show that providing haptic feedback improved surgical safety compared to visual-only feedback. If staying inside the vasculature is the priority, RL provides the safest option. It is also shown that the performance of each force profile varies in different anatomical regions. CONCLUSION: The implications of these findings are significant, as they hold the potential to improve how and when haptic feedback is applied for cardiovascular intervention.

Cone-wedge anchored surgical templates for stackable metal guide: a novel technique.

OBJECTIVE: To address the instability in implant surgical guides, this technique proposes an alternative anchoring mechanism in the stackable metal surgical guides utilizing cone-wedge anchors for improved stability. METHODS: Postoperative implant position superimposed onto the preoperatively planned design using Mimics Medical 21.0 and Materialise Magics 24.0 to assess 3D coronal implant deviation, 3D apical implant deviation, and implant angular deviation. RESULTS: Postoperative cone-beam computed tomography (CBCT) revealed a high level of precision in the implant placement, with an average 0.97 mm deviation at implant coronal region, 1.56 mm at implant apexes, and 2.95° angular deviation. CONCLUSION: This technique introduces a novel cone-wedge anchoring mechanism to enhance the stability of stackable metal surgical guide templates, addressing inherent instability issues. The utilization of this approach significantly improves the accuracy of implant placement procedures.

ERegPose: An explicit regression based 6D pose estimation for snake-like wrist-type surgical instruments.

BACKGROUND: Accurately estimating the 6D pose of snake-like wrist-type surgical instruments is challenging due to their complex kinematics and flexible design. METHODS: We propose ERegPose, a comprehensive strategy for precise 6D pose estimation. The strategy consists of two components: ERegPoseNet, an original deep neural network model designed for explicit regression of the instrument's 6D pose, and an annotated in-house dataset of simulated surgical operations. To capture rotational features, we employ an Single Shot multibox Detector (SSD)-like detector to generate bounding boxes of the instrument tip. RESULTS: ERegPoseNet achieves an error of 1.056 mm in 3D translation, 0.073 rad in 3D rotation, and an average distance (ADD) metric of 3.974 mm, indicating an overall spatial transformation error. The necessity of the SSD-like detector and L1 loss is validated through experiments. CONCLUSIONS: ERegPose outperforms existing approaches, providing accurate 6D pose estimation for snake-like wrist-type surgical instruments. Its practical applications in various surgical tasks hold great promise.

The realization of medical devices for precision surgery - development and implementation of 'stop-and-go' imaging technologies.

INTRODUCTION: Surgery and biomedical imaging encompass a big share of the medical-device market. The ever-mounting demand for precision surgery has driven the integration of these two into the field of image-guided surgery. A key-question herein is how imaging modalities can guide the surgical decision-making process. Through performance-based design, chemists, engineers, and doctors need to build a bridge between imaging technologies and surgical challenges. AREAS-COVERED: This perspective article highlights the complementary nature between the technological design of an image-guidance modality and the type of procedure performed. The specific roles of the involved professionals, imaging technologies, and surgical indications are addressed. EXPERT-OPINION: Molecular-image-guided surgery has the potential to advance pre-, intra- and post-operative tissue characterization. To achieve this, surgeons need the access to well-designed indication-specific chemical-agents and detection modalities. Hereby, some technologies stimulate exploration ('go'), while others stimulate caution ('stop'). However, failing to adequately address the indication-specific needs rises the risk of incorrect tool employment and sub-optimal surgical performance. Therefore, besides the availability of new technologies, market growth is highly dependent on the practical nature and impact on real-life clinical care. While urology currently takes the lead in the widespread implementation of image-guidance technologies, the topic is generic and its popularity spreads rapidly within surgical oncology.

Current knowledge about stackable guides: a scoping review.

PURPOSE: The rise of stereolithographic surgical guides and digital workflow, combined with a better knowledge of materials and loading principle, has enabled the placement of the temporary prosthesis at the time of implant placement. This scoping review aimed to assess the current knowledge available on stackable guides. METHODS: The review focused on fully edentulous or requiring total edentulism patients. The procedure studied was the use of stackable guides for edentulous patients in order to place immediate temporary prostheses. The clinical endpoint was immediate placement of the provisional prosthesis after surgery combined with a prior bone reduction using a stackable guide. RESULTS: 12 case reports or case series articles met inclusion criteria, which did not allow an analysis by a systematic review. The included studies were case reports or case series. Most of the articles showed a base stabilized by 3 or 4 bone-pins, anchored in buccal or lingual part. Regarding the accuracy of bone reduction (ranged from 0.0248 mm to 1.98 mm) and implant placement when compared to planned, only 4 articles reported quantitative data. 11 articles showed an immediate loading with the transitional prosthesis after implant placement. CONCLUSIONS: There are as yet no prospective or comparative studies on the efficiency of this technique. In a reliable way, stackable guides seem to be able to guide the practitioner from the flap elevation to the placement of the temporary screw-retained implant supported prosthesis. Given the lack of studies in this specific field of guided surgery, further studies are needed to confirm the clinical relevance of this technique.

A novel guide device for pedicle screw insertion using three-dimensional preoperative planning in open lumbar spinal surgery: a comparative retrospective study.

OBJECTIVE: Pedicle screw stabilization (PSS) surgeries for spinal instability are still the most effective treatment approach. The use of preoperative planning can minimize the complications related to transpedicular screw (TPS) misplacement. The study aimed to evaluate the surgical outcomes of a guide device developed to improve the accuracy of the free-hand technique using three-dimensional planning in PSS. PATIENTS AND METHODS: Patients with degenerative spinal diseases who underwent open PSS between 2019 and 2022 were evaluated retrospectively. FG group included patients who were operated on using the fluoroscopy alone with preoperative two-dimensional planning. AFG group included patients who were operated on using a guide advice-assisted technique with preoperative 3DP. Between-group comparisons were performed. RESULTS: A total of 143 patients with a mean age of 59.6 years were included in the study. 71 patients were assessed in the FG group and 72 patients in the AFG group. Between-group comparisons regarding demographics, etiologies, radiation exposure, and functional improvements showed no significant differences (p > 0.05). Although the accuracy of TPSs positioning was 94.2% and 96.5% in the 2DG and 3DG, the difference between the groups was not statistically significant. The statistically significant differences regarding the upper-level facet joint violation and pedicle breach rates were lower in the AFG group (p < 0.0001; X2 = 19.57) and (p < 0.0001; X2 = 25.3), respectively. CONCLUSION: Using a guide device associated with preoperative 3PD reduced the upper-level facet joint violation and pedicle breach rates in open PSS surgeries performed by free-hand technique for degenerative spinal diseases.

Novel Image-Guided Percutaneous Lung Tissue Excision Device With Integrated Sealing of Blood Vessels and Airways: An In Vivo Preclinical Study.

OBJECTIVE: This study evaluated the efficacy of the Minimally Invasive Targeted Resection (MiTR) device, a novel electrosurgical instrument that allows for targeted excision of a lung abnormality while using bipolar radiofrequency (RF) energy to seal blood vessels and airways. METHODS: The MiTR system was evaluated in 7 acute and 2 chronic porcine (7-day) models to evaluate the efficacy of tissue excision with bipolar RF sealing of blood vessels and airways and application of an autologous blood patch into the excised tissue cavity. Air leak was recorded for all evaluations. The study was approved by the institutional ethical board. RESULTS: Nineteen lung tissue samples, measuring 2.5 cm long × 1.2 cm diameter, were excised. In 8 of 9 animals (89%), hemostasis and pneumostasis were observed visually at the completion of the procedure. In 2 of 2 chronic animals (100%), hemostasis and pneumostasis persisted for the 7-day observation period. Histologic examination of the excised samples showed preservation of the core parenchymal architecture without evident tissue damage of the samples that would impair pathologic analysis. CONCLUSIONS: Percutaneous resection of targeted lung tissue with the MiTR system demonstrated hemostasis and pneumostasis while obtaining a histologically intact sample. After regulatory approval, the use of this device could offer more tissue for analysis than a transthoracic needle biopsy or bronchoscopy and a far less invasive alternative to video-assisted thoracic surgery or thoracotomy. This may also expand patient and physician options for the early diagnosis and treatment of lung cancer.

[The digital operating room : Chances and risks of artificial intelligence]. / Der digitale Operationssaal : Chancen und Risiken künstlicher Intelligenz.

At the central workplace of the surgeon the digitalization of the operating room has particular consequences for the surgical work. Starting with intraoperative cross-sectional imaging and sonography, through functional imaging, minimally invasive and robot-assisted surgery up to digital surgical and anesthesiological documentation, the vast majority of operating rooms are now at least partially digitalized. The increasing digitalization of the whole process chain enables not only for the collection but also the analysis of big data. Current research focuses on artificial intelligence for the analysis of intraoperative data as the prerequisite for assistance systems that support surgical decision making or warn of risks; however, these technologies raise new ethical questions for the surgical community that affect the core of surgical work.

Use of a Novel Beyeonics One Three-dimensional Head-mounted Digital Visualization Platform in Vitreoretinal surgeries.

BACKGROUND: Ophthalmic microscopes have been crucial in visualizing surgical fields, but their limitations in enhancing the surgical view through digital image processing have prompted the development of digital surgical microscopes. The Beyeonics One microscope, a novel digital microscope, offers ophthalmic surgeons a 3D visualization platform and an augmented reality (AR) surgical headset, potentially improving surgical decision-making and outcomes. While its initial use has been described in cataract and corneal surgeries, its application in vitreoretinal surgery remains relatively unexplored. METHODS: In this interventional case series, we collected data from the medical records of patients who underwent vitreoretinal surgery using the Beyeonics One 3D visualization platform at the Tel Aviv Medical Center. A total of 36 eyes from 36 subjects were included. Surgical techniques included retinal detachment surgeries and macular surgeries, performed by experienced surgeons. The surgical visualization was facilitated by the Beyeonics One 3D head-mounted display (HMD) platform. RESULTS: The procedures were uneventful, and none intra- or postoperative complications were reported, and surgeons did not experience any signal delay in the real-time video. DISCUSSION: The Beyeonics One microscope offers several potential advantages in vitreoretinal surgery, including digital image processing, enhanced depth perception through the 3D HMD platform, and hands-free image control using head gestures. While this study demonstrates the feasibility and safety of the Beyeonics One microscope, addressing limitations related to hazy views and optimizing image quality are crucial for consistent visualization.

Ex vivo comparison of pin placement with patient-specific drill guides or freehand technique in canine cadaveric spines.

OBJECTIVE: To compare vertebral implant placement in the canine thoracolumbar spine between 3D-printed patient-specific drill guides (3DPG) and the conventional freehand technique (FH). STUDY DESIGN: Ex vivo study. ANIMALS: Cadaveric canine spines (n = 24). METHODS: Implant trajectories were established for the left and right sides of the T10 through L6 vertebrae based on computed tomography (CT) imaging. Customized drill guides were created for each vertebra of interest. Each cadaver was randomly assigned to one of six veterinarians with varying levels of experience placing vertebral implants. Vertebrae were randomly assigned a surgical order and technique (3DPG or FH) for both sides. Postoperative CT images were acquired. A single, blinded observer assessed pin placement using a modified Zdichavsky classification. RESULTS: A total of 480 implants were placed in 240 vertebrae. Three sites were excluded from the analysis; therefore, a total of 238 implants were evaluated using the FH technique and 239 implants using 3DPG. When evaluating implant placement, 152/239 (63.6%) of 3DPG implants were considered to have an acceptable placement in comparison with 115/248 (48.32%) with FH. Overall, pin placement using 3DPG was more likely to provide acceptable pin placement (p < .001) in comparison with the FH technique for surgeons at all levels of experience. CONCLUSION: The use of 3DPG was shown to be better than the conventional freehand technique regarding acceptable placement of implants in the thoracolumbar spine of canine cadavers. CLINICAL SIGNIFICANCE: Utilizing 3DPG can be considered better than the traditional FH technique when placing implants in the canine thoracolumbar spine.

SIG-Former: monocular surgical instruction generation with transformers.

PURPOSE: Automatic surgical instruction generation is a crucial part for intra-operative surgical assistance. However, understanding and translating surgical activities into human-like sentences are particularly challenging due to the complexity of surgical environment and the modal gap between images and natural languages. To this end, we introduce SIG-Former, a transformer-backboned generation network to predict surgical instructions from monocular RGB images. METHODS: Taking a surgical image as input, we first extract its visual attentive feature map with a fine-tuned ResNet-101 model, followed by transformer attention blocks to correspondingly model its visual representation, text embedding and visual-textual relational feature. To tackle the loss-metric inconsistency between training and inference in sequence generation, we additionally apply a self-critical reinforcement learning approach to directly optimize the CIDEr score after regular training. RESULTS: We validate our proposed method on DAISI dataset, which contains 290 clinical procedures from diverse medical subjects. Extensive experiments demonstrate that our method outperforms the baselines and achieves promising performance on both quantitative and qualitative evaluations. CONCLUSION: Our experiments demonstrate that SIG-Former is capable of mapping dependencies between visual feature and textual information. Besides, surgical instruction generation is still at its preliminary stage. Future works include collecting large clinical dataset, annotating more reference instructions and preparing pre-trained models on medical images.

Three-dimensional heads-up surgery in ab-interno trabeculotomy: Image processing-assisted trabeculotomy.

PURPOSE: We compared the visibility and surgeon posture between image-processing-assisted trabeculotomy (IP-LOT) using the NGENUITY® 3D visual system and conventional microsurgery (microscope-assisted trabeculotomy; MS-LOT). METHODS: IP-LOT was performed for five pig eyes. The visibility of the trabecular mesh work was evaluated on images of the trabecular mesh work and the posterior surface of the cornea (Cor) obtained under three different conditions. Images were then analyzed using ImageJ® to measure differences in luminance between the trabecular mesh work and Cor. IP-LOT was also performed for eleven human eyes, and the data were analyzed using the same approach as that used for the pig eyes. The length from the surgeon's abdomen to the operative eye (working distance) during MS-LOT and IP-LOT was measured for 12 different surgeons and compared to evaluate surgeon posture. RESULTS: Image processing significantly increased the difference in luminance between the trabecular mesh work and Cor in both pig and human eyes (p < 0.05). Moreover, the working distance in IP-LOT was significantly shorter than that in MS-LOT (p < 0.05). CONCLUSION: Our findings suggest that the NGENUITY® 3D visual system provides better trabecular mesh work visibility than a normal microscope in conventional surgical methods, and it allows surgeons to operate without moving far from the operative eye.

Image Navigation Surgery With the Fluorescent Ureteral Catheter of Recurrent Tumors in the Pelvic Cavity.

INTRODUCTION: Ureteral injury during pelvic surgery is a serious complication that requires special attention. The fluorescent ureteral catheter near-infrared ray catheter sets are 6.0F catheters containing fluorescent substances along their length that can be recognized by a laparoscopic indocyanine green camera. We present our experience using a near-infrared ray catheter in 6 consecutive patients who underwent surgery for recurrent pelvic tumors. TECHNIQUE: The near-infrared ray catheters were inserted into the bilateral ureters in all patients, with the exception of patient 5 (left unilateral), by urologists using a cystoscope with the same technique as that commonly used in placing ureteral stents under general anesthesia. A laparoscopic indocyanine green camera was adapted to identify the ureters. From February 2020 to July 2020, 6 consecutive patients with recurrent pelvic tumors underwent surgery using a near-infrared ray catheter. In 3 patients, recurrent tumors were detected in the pelvic cavity after surgery for colon cancer (1 patient each of peritoneal recurrence behind the seminal vesicles, lymph node metastasis on the residual superior rectal artery, and peritoneal recurrence at the peritoneal reflection). Two patients had postoperative local recurrences of rectal cancer. The last patient had a recurrence of cervical carcinoma invading the rectum. RESULTS: All patients underwent surgery under ureteral image navigation using near-infrared ray catheter not only for ureter preservation during the operation (4 patients) but also for the combined resection of the ureter with recurrent tumors (2 patients). One patient experienced postoperative ureteral stenosis on postoperative day 21 that required a ureteral double J-stent placement in the left ureter. CONCLUSION: Near-infrared ray catheter has the potential to reduce inadvertent periureteral dissection because the ureter can be identified before approaching it.

Comparison of vacuum-assisted excision (VAE) and breast lesion excision system (BLES) in the treatment of intraductal papillomas.

PURPOSE: This study aims to compare the feasibility of VAE and BLES in the treatment of intraductal papillomas. MATERIAL AND METHODS: Patients with a suspected intraductal papilloma who underwent a BLES or a VAE procedure were included in this retrospective study. The BLES procedures were performed between November 2011 and June 2016 and the VAE procedures between May 2018 and September 2020 at the Department of Radiology of Helsinki University Hospital (HUH). The procedures were performed with an intent of complete removal of the lesions. RESULTS: In total, 72 patients underwent 78 BLES procedures and 95 patients underwent 99 VAE procedures. Altogether 52 (60%) papillomas with or without atypia were completely removed with VAE, whereas 24 (46%) were completely removed with BLES, p = 0.115. The median radiological size of the high-risk lesions completely removed with BLES was 6 mm (4-12 mm), whereas with VAE it was 8 mm (3-22 mm), p = 0.016. Surgery was omitted in 90 (94.7%) non-malignant breast lesions treated with VAE and in 66 (90.4%) treated with BLES, p = 0.368. CONCLUSION: Both VAE and BLES were feasible in the treatment of intraductal papillomas. In most non-malignant lesions surgery was avoided, but VAE was feasible in larger lesions than BLES. However, follow-up ultrasound was needed more often after VAE. The histopathologic assessment is more reliable after BLES, as the lesion is removed as a single sample.

From the Reading Room to Operating Room: Retrospective Data and Pictorial Review After 806 SCOUT Placements.

OBJECTIVE: Non-wire localization techniques are becoming more common. SCOUT surgical guidance system has been shown to increase flexibility in scheduling patients for surgery. The objective of this article is to provide institutional experiences with pictorial review after placement of 806 SCOUT devices. MATERIALS AND METHODS: Radiology procedure reports of SCOUT device placements from January 11, 2018 to May 19, 2020 were reviewed to assess demographics of patient population, imaging method of placement, size of reflector delivery system used, placement approach, and time spent in the radiology suite or Turn Around Time (TAT). TAT was compared to that of wire placement using a Two-tailed Mann-Whitney U Test. Reports were assessed for those with absent signal at time of placement. In cases where signal was absent, migration was found, or complications noted, further case review was performed using the Electronic Medical Record to assess whether the devices were successfully retrieved. RESULTS: There were 806 total SCOUT placements identified from radiology procedure reports in patients aged 12-92 with 64.3% (518/806) placed using ultrasound-guidance and 35.7% (288/806) by mammographic-guidance. The most common delivery device was a 7.5 cm needle. Only 0.9% (7/806) of SCOUT reflectors were >1cm from target, all of which were successfully excised. After radiology placement, signal was not heard in 1.4% (9/806) of cases and individual case review revealed that all were successfully excised. In 2019, TATs of SCOUT procedures were significantly lower than TATs from wire localizations (P = 0.00024). CONCLUSIONS: SCOUT localization for breast surgery can provide solutions to problems encountered by patients and providers. A year after implementation, SCOUT use was found to result in shorter TATs in radiology. In addition, 100% of devices that were either migrated or inaudible at the time of radiology placement were successfully excised.

EndoNaut two-dimensional fusion imaging with a mobile C-arm for endovascular treatment of occlusive peripheral arterial disease.

BACKGROUND: Endovascular treatment has become the first-line strategy for peripheral arterial disease (PAD). Given the number of procedures required, any technology associated with a reduction in radiation exposure and contrast volume is highly relevant. In the present study, we evaluated whether two-dimensional (2D) fusion imaging could reduce the radiation exposure and contrast volume during endovascular treatment of occlusive PAD. METHODS: Our consecutive, retrospective, single-center, nonrandomized comparative trial included patients with PAD at the femoral, popliteal, and/or tibial level, at any clinical stage, if they were candidates for endovascular revascularization. Patients were treated with or without the EndoNaut 2D fusion imaging system (Therenva, Rennes, France) in a nonhybrid room with the same Cios Alpha mobile C-arm (Siemens, Munich, Germany). The indirect dose-area product and contrast medium volume were recorded. RESULTS: Between March 2018 and April 2020, 255 patients underwent endovascular femoropopliteal revascularization with (n = 124) or without (n = 131) 2D fusion imaging. The volume of injected contrast medium (34.7 ± 13.8 mL vs 51.3 ± 26.7 mL; P < .001) and dose-area product (8.9 ± 9.9 Gy/cm2 vs 13.5 ± 14.0 Gy/cm2; P = .003) were significantly lower for the 2D fusion imaging group than for the control group. A subgroup analysis of complex (TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease C/D) lesions showed similar results. Stratification of the fusion imaging group into three subgroups, according to the procedure dates, showed no effect of a potential learning curve on the operative parameters. CONCLUSIONS: The results from the present study showed a significant reduction in the contrast volume and radiation dose for endovascular treatment of PAD when applying 2D fusion imaging technology. Overall, a reduction of >30% was observed for both operative parameters, without excessive training requirements, highlighting the potential benefits of using 2D fusion imaging when performing endovascular revascularization for PAD.

Twenty-seven-gauge endoilluminator-assisted scleral buckling using a wide-field viewing system: Case report.

RATIONALE: We report a new scleral buckling technique using a 27-gauge endoilluminator and a wide-field viewing system to overcome the limitations of conventional indirect ophthalmoscope-methods and "chandelier-assisted" surgery. PATIENT CONCERNS: A 26-year-old female patient visited the local clinic for floaters and lower visual field defects in her left eye that had occurred 5 days prior. DIAGNOSES: On fundus examination, upper retinal detachment without macular involvement and an atrophic hole was observed in her left eye. INTERVENTIONS: Under general anesthesia and after perilimbal conjunctival incision, extraocular muscle isolation, and traction with black silk, a 27-gauge trocar-cannula was inserted 90° away from the retinal break, 4 mm away from the limbus. Under wide-field viewing using a contact lens, the fundus was observed through a surgical microscope. Retinal break was evaluated and cryopexy was performed with careful movement of the endoilluminator, paying attention to damage to the lens. The surgeon could accurately and freely control the direction of the illumination tip to obtain a brighter view of the region of interest. OUTCOMES: There were no complications associated with trocar cannula incision or the illuminator. The retina was successfully reattached. LESSONS: Twenty seven gauge endoilluminator-assisted scleral buckling is an easy and safe procedure and provides better control over and free adjustment of the light direction, thus overcoming the limitations of chandelier-assisted surgery.

High density mapping guided partial antral ablation for a pulmonary vein isolation.

The muscular discontinuities at the pulmonary vein (PV)-left atrial (LA) junction are known. The high-density mapping may help to find the muscular discontinuity. This study evaluated the efficacy of a partial antral ablation for a pulmonary vein (PV) isolation using high density (HD) mapping. A total of 60 drug-refractory atrial fibrillation (AF) patients undergoing catheter ablation were enrolled. The detailed activation mapping of each PV and LA junction was performed using an HD mapping system, and each PV segment's activation pattern was classified into a "directly-activated from the LA" or "passively-activated from an adjacent PV segment" pattern. The antral ablations were performed at the directly-activated PV segments only when the PV had "passively-activated segments". If the PV did not contain passively-activated segments, a circumferential antral ablation was performed on those PVs. A "successful partial antral ablation" was designated if the electrical isolation of targeted PV was achieved by ablation at the directly-activated segments only. If the isolation was not achieved even though all directly-activated segments were ablated, a "failed partial antral ablation" was designated, and then a circumferential ablation was performed. Among 240 PVs, passively-activated segments were observed in 140 (58.3%) PVs. Both inferior PVs had more passively-activated segments than superior PVs, and the posteroinferior segments had the highest proportion of passive activation. The overall rate of successful partial antral ablation was 85%. The atrial tachyarrhythmia recurrence was observed in 10 patients (16.7%) at 1-year. HD mapping allowed the evaluation of the detailed activation patterns of the PVs, and passively-activated segments may represent muscular discontinuity. Partial antral ablation of directly-activated antral segments only was feasible and effective for a PVI.