Preoperative Simulation Research Articles

Utilization of three-dimensional fusion images with high-resolution computed tomography angiography for preoperative evaluation of microvascular decompression: patient series.

High-resolution computed tomography (CT), outfitted with a 0.25-mm detector, has superior capability for identifying microscopic anatomical structures compared to conventional CT. This study describes the use of high-resolution computed tomography angiography (CTA) for preoperative microvascular decompression (MVD) assessment and explores the potential effectiveness of three-dimensional (3D) image fusion with magnetic resonance imaging (MRI) by comparing it with traditional imaging methods. Four patients who had undergone preoperative high-resolution CTA and MRI for MVD at Osaka University Hospital between December 2020 and March 2022 were included in this study. The 3D-reconstructed images and intraoperative findings were compared. One patient underwent conventional CTA, thus allowing for a comparison between high-resolution and conventional CTA in terms of radiation exposure and vascular delineation. Preoperative simulations reflected the intraoperative findings for all cases; small vessel compression of the nerve was identified preoperatively in two cases. Compared with conventional CTA, high-resolution CTA showed superior vascular delineation with no significant change in radiation exposure. The use of high-resolution CTA with reconstructed 3D fusion images can help to simulate prior MVD. Knowing the location of the nerves and blood vessels can perioperatively guide neurosurgeons.

Sutures positioning technique enhances the predictability and concordance between preoperative simulation and actual outcomes in rhinoplasty

The predictability and concordance between simulated and actual outcomes in rhinoplasty are uncertain. Here, we introduce a suture positioning technique (SPT), a simple and low-cost method to minimize the gap between the simulated and actual outcomes of rhinoplasty. Seventy patients were enrolled in this study between January 2018 and January 2021. Preoperative simulations were performed using Adobe Photoshop. The control group underwent surgery using simulation and intuition. In the SPT group, sutures were used to assist in the preoperative identification of the ideal nasal tip position. The SPT effectiveness was tested by measuring the nasal parameters and using the patient's subjective satisfaction questionnaire at T1 (Time 1, immediately postoperatively) and T2 (Time 2, at least 1 year postoperatively). The intraclass correlation coefficient test showed a satisfactory correlation between simulation and postoperative outcomes in both groups. However, the SPT group had a higher correlation than the control group, especially for the nasal length (16% higher at T1 and 15% higher at T2). The mean absolute difference (MAD) between the outcomes and simulation indicated that the MAD of nasal tip projection between T2 and simulation and MAD of nasal length between T1 (or T2) and simulation were statistically significant between groups. Additionally, the SPT group was more satisfied with the postoperative outcomes and were consistent with the preoperative simulation. This study demonstrated the effectiveness of SPT in intraoperative quality control. This technique may be adopted by surgeons to achieve good concordance between simulated and actual surgical outcomes.

3D simulation of percutaneous sustentaculum tali screw insertion in calcaneal fractures

BackgroundIn calcaneal fractures, the percutaneous screw fixation (PSF) is currently considered to be the better choice, but it is difficult to accurately place the screw into the sustentaculum tali (ST) during the operation. In this study, the ideal entry point, angle, diameter and length of the screw were calculated by simulating the operation process.MethodsWe retrospectively collected the calcaneus computed tomography (CT) scans of 180 adults, DICOM-formatted CT-scan images of each patient were imported into Mimics software to establish calcaneus model. Virtual screws were placed on the lateral of the posterior talar articular surface (PTAS), the lateral edge of the anterior process of calcaneus (APC), and the calcaneal tuberosity, respectively, the trajectory and size of the screws were calculated.ResultsThe mean maximum diameter of the PTAS screw was 42.20 ± 3.71 mm. The vertical distance between the midpoint of the APC optimal screw trajectory and the lowest point of the tarsal sinus was 10.67 ± 1.84 mm, and the distance between the midpoint of the APC optimal screw trajectory and the calcaneocuboid joint was 5 mm ~ 19.81 ± 2.08 mm. The mean maximum lengths of APC screws was 44.69 ± 4.81 mm, and the Angle between the screw and the coronal plane of the calcaneus from proximal to distal was 4.72°±2.15° to 20.52°±3.77°. The optimal point of the maximum diameter of the calcaneal tuberosity screw was located at the lateral border of the achilles tendon endpoint. The mean maximum diameters of calcaneal tuberosity screws was 4.46 ± 0.85 mm, the mean maximum lengths of screws was 65.31 ± 4.76 mm. We found gender-dependent differences for the mean maximum diameter and the maximum length of the three screws.ConclusionsThe study provides effective positioning for percutaneous screw fixation of calcaneal fractures. For safer and more efficient screw placement, we suggest individualised preoperative 3D reconstruction simulations. Further biomechanical studies are needed to verify the function of the screw.

3D printing of costal cartilage models with fine fidelity and biomimetic mechanical performance for ear reconstruction simulation

 Patient-based training is difficult in ear reconstruction surgery; therefore, costal cartilage models are required for surgical education and pre-operative simulation. Here, we aimed to fabricate personalized models with mechanical and structural similarity to native costal cartilage to simulate ear reconstruction in microtia patients. To achieve this, the stiffness, hardness, and suture retention ability of both native costal cartilage and printed silicone were experimentally examined in vitro. Rheological tests and three-dimensional (3D) comparison methods were used to evaluate the printing ability and outcomes. The printed silicone models were used by residents to practice ear framework handcrafting during ear reconstruction surgery, and the residents’ learning curves were analyzed. In addition, the models were used for pre-operative simulation to study and optimize the surgical plan. The results showed that the consistency of mechanical properties within cartilage and silicone was verified. Printable silicone had good shear-thinning properties, and the printed structures had almost perfect printing fidelity. Residents who used printed silicone models enjoyed great progress and confidence after training. The pre-operative simulation optimized the carving scheme, reduced trauma in the operative site, and avoided wasting necessary cartilage tissue. Overall, fine-fidelity models created in this study were intended for surgical education and pre-operative simulation by applying 3D-printable (3DP) silicone, facilitating the optimization of surgical plans. Surgeons were satisfied with this kind of model and recognized the efficacy and great application value of 3D-printed silicone models for clinical practice.

Estimation of Mastectomy Volume Using Preoperative Mastectomy Simulation Images Acquired by the Vectra H2 System.

All patients underwent skin-sparing mastectomy and immediate autologous breast reconstruction. Preoperatively, the patient's breast was scanned using the Vectra H2 and a postmastectomy simulation image was constructed on a personal computer. The estimated mastectomy volume was calculated by comparing the preoperative and postmastectomy three-dimensional simulation images. Correlation coefficients with the estimated mastectomy volume were calculated for the actual mastectomy weight and the transplanted flap weight. Forty-five breasts of 42 patients were prospectively analyzed. The correlations with the estimated mastectomy volume were r = 0.95 (P < 0.0001) for actual mastectomy weight and r = 0.84 (P < 0.0001) for transplanted free-flap weight. The mastectomy weight estimation formula obtained by linear regression analysis using the estimated mastectomy volume was 0.98 × estimated mastectomy volume + 5.4 (coefficient of determination R2 = 0.90, P < 0.0001). The root-mean-square error for the mastectomy weight estimation formula was 38 g. We used the Vectra H2 system to predict mastectomy volume. The predictions provided by this method were highly accurate. Three-dimensional imaging is a noncontact, noninvasive measurement method that is both accurate and simple to perform. Use of this effective tool for volume prediction is expected to increase in the future.

A case of tracheotomy using the Ex Utero Intrapartum Treatment (EXIT) procedure in cooperation with multiple professions.

In this study, we report a case of tracheotomy using the ex utero intrapartum treatment (EXIT) procedure in a fetus that was pointed out as having bilateral giant cervical cysts at prenatal diagnosis and whose postnatal airway occlusion was predicted. The subject was a female aged 35. She was diagnosed with polyhydramnios at 28 weeks of pregnancy. The fetus was found to have a giant cervical cyst before she was referred to the department of obstetrics and gynecology of our hospital. On the second day of 37 weeks of pregnancy, oral tracheal intubation was attempted on the fetus using the EXIT procedure after the caesarean operation, but intubation was difficult resulting in a tracheotomy. The oxygenation of the fetus during the operation was maintained well without any postoperative complication. Postnatal fetal airway occlusion is a critical incident which may lead to the death of a fetus. It was assumed, however, that the airway management under the same procedure was completed by the preoperative detailed simulation with the staff of the departments of anesthesiology, obstetrics and gynecology and pediatrics as well as the operating room personnel.

Preoperative Rehearsal Sketch for Cerebral Aneurysm Clipping Improves the Accuracy and the Safety of the Surgical Procedure

With advances in endovascular therapy, the number of cerebral aneurysm clippings has been decreasing. However, some patients are indicated for clipping surgeries. In such circumstances, preoperative simulation is important for the safety and educational aspects of the operation. Herein, we introduce a simulation method using the preoperative rehearsal sketch and report its applicability. We compared the preoperative rehearsal sketch with the surgical view for all patients who underwent cerebral aneurysm clipping by neurosurgeons below the seventh grade between April 2019 and September 2022 in our facility. The aneurysm, running of parent and branched arteries, perforators, veins, and clip working were evaluated by senior doctors and scored as follows: correct, 2; partially correct, 1; incorrect, 0; and total score, 12. We retrospectively evaluated the relationship between these scores and postoperative perforator infarctions and, in addition, compared that between simulated and not simulated cases. In the simulated cases, the total scores did not correlate with perforator infarctions, but assessments of the aneurysm, perforators, and clip working affected thetotal score (P= 0.039, 0.014, and 0.049, respectively). Moreover, perforator infarctions were significantly less inthe simulated cases (6.3% vs. 38.5%; P= 0.03). Precise interpretations of preoperative images and considerations of three-dimensional images are imperative to perform safe and accurate surgeries using preoperative simulation. Although perforators are not always detected preoperatively, it is possible to presume in the surgical view using anatomic knowledge. Therefore, drawing the preoperative rehearsal sketch improves the safety of surgical procedure.

Preoperative computer imaging before augmentation rhinoplasty.

In the present study, we investigated the efficacy of morphing technology via Adobe PhotoShop program and its "liquefy" effect in patients planned to undergo augmentation rhinoplasty. The retrospective data for 100 consecutive augmentation rhinoplasty cases (64 females and 36 males) were enrolled in our study. Preoperative computer imaging (PCI) steps, a stepwise systematic guide for image editing, including (1) augmenting the dorsum, (2) lengthening the nose, (3) adjusting the tip projection, (4) perfection of the nasal dorsum and (5) exaggerating the tip projection and/or the dorsal augmentation were applied to the patients. After performing the PCI before augmentation rhinoplasty, the patients were allowed to see the options for the final appearance of their noses. Therefore, PCI helped them to decide on their operations. After applying CS-PCI before augmentation rhinoplasty, 71 patients (71%) accepted Step-4, and 19 (19%) accepted Step-3. Furthermore, six patients (6%) requested additional changes during their operational planning. In 95% of the cases, the authors achieved the results agreed upon based on the preoperative simulation. By PCI involving five steps for augmentation rhinoplasty, the patients were allowed to see the options for the final appearance of their noses. Therefore, PCI helped them to decide on their operations. With the help of morphing technology (2D), it is possible to increase interpersonal communication effectively.

Current applications of 3-dimensional printing in spine surgery

BackgroundThree-dimensional printing (3D Printing) has emerged as a new technology in the early part of the 21st century, with promising applications in various industries, including the medical field. Spine care is a complex sub-specialty that has shown rapid inculcation of 3D printing. This technology is being used in pre-operative planning, patient education, and simulations, as well as intra-operatively for assistance in the form of patient specific jigs for pedicle screw placement and as implantable material in the form of vertebral body substitutes and patient-specific interbody cages. Applications3DP in spine care has broadened the scope of minimally invasive and spine deformity surgeries. It has also enabled the production of patient-specific implants for complex spinal malignancies and infections. The technology has been embraced by various government organizations, including the US-FDA, which has drafted guidelines for the medical use of 3DP. DrawbacksDespite these promising advances and results, there still exist some significant drawbacks to the universal application of 3D printing technology. One of the main limitations is the dearth of long-term data describing the advantages and drawbacks in its clinical use. The widespread adoption of 3D models in small-scale healthcare setups is impeded by significant factors such as the high cost associated with their production, the requirement for specialized human resources, and specific instrumentation. ConclusionAs technological understanding increases, newer applications and innovations in spine care are expected to unravel in the near future. With the expected surge in 3DP applications in spine care, it is imperative for all spine surgeons to possess a rudimentary understanding of this technology. Although there are still limitations to its universal use, 3DP in spine care has shown promising results and has the potential to revolutionize the field of spine surgery.

Supraorbital keyhole approach for paraclinoid aneurysms clipping: A case series with literature review.

Paraclinoid aneurysms (PcAs) are challenging aneurysms due to the complexity of their relation to the surrounding bony and neurovascular structures. Although over the past decade, their management strategy has shifted from transcranial to endovascular approaches; here, we try to revolve around a subcategory to which minimal invasive supraorbital keyhole (SOK) surgery is feasible depending on specific radiological criteria with a literature review. A group of unruptured PcAs was managed surgically, with a subset that was clipped through the SOK approach. They were selected by preoperative simulation images using 3D computed tomography (CT) angiography (CTA). We also conducted an extensive literature review based on a database available on PubMed and Google Scholar, the yielded cases from the literature review plus our cases were analyzed according to six parameters including their size, location, dome direction, need for clinoidectomy and proximal cervical control, and surgical outcome. From February 2009 to August 2022, 49 cases of unruptured PcAs were managed by clipping, and of these, four cases were clipped by the SOK approach, in addition, four cases were yielded through the literature review. The sizes of the PcAs ranged from 3 to 8 mm. Their location fluctuated from anterior to the superomedial wall and their domes pointed superiorly except for one which points posteriorly. Six of eight cases required anterior clinoidectomy, the outcome was uneventful. A subset of unruptured PcAs are amenable to SOK with criteria such as unruptured small aneurysm (<10 mm) and projected superiorly. These characteristics can be determined preoperatively using CTA.

Trigeminal neuralgia caused by a persistent primitive trigeminal artery: preoperative three-dimensional multifusion imaging and computational fluid dynamics analysis. Illustrative case.

Trigeminal neuralgia (TN) is caused by trigeminal nerve compression by colliding vessels. Preoperative three-dimensional (3D) multifusion images are useful for surgical simulations. Moreover, computational fluid dynamics (CFD) analysis of colliding vessels may be useful for hemodynamic evaluation at the site of neurovascular contact (NVC). A 71-year-old woman had TN due to compression of the trigeminal nerve by the superior cerebellar artery (SCA) fused with the persistent primitive trigeminal artery (PTA). Preoperative 3D multifusion simulation images of silent magnetic resonance (MR) angiography and MR cisternography depicted the NVC, including the trigeminal nerve, SCA, and PTA. CFD analysis revealed the hemodynamic condition of the NVC, including the SCA and PTA. The wall shear stress magnitude (WSSm) at the NVC showed a local elevation due to flow confluence from the SCA and PTA. High WSSm was observed in the NVC. Preoperative simulation images of MR angiography and MR cisternography may depict the NVC. CFD analysis can provide the hemodynamic condition at the NVC.

Efficient removal technique of foreign body in the mandible with optimization of 3D simulation

AbstractBackgroundForeign bodies may be deposited in the oral cavity either by traumatic injury or iatrogenic damage.Case PresentationWe describe a case of foreign body removal using a three‐dimensional reconstruction (3D) simulation application (ProPlan CMF™) involving a case of a 26‐year‐old male. The broken bur had been accidentally inserted when a lower wisdom tooth was extracted at a general dental office. The removal surgery was performed under preoperative simulation without complications (e.g., excessive bleeding and nerve paralysis).ConclusionThis case illustrates surgical techniques to safely remove foreign bodies in the mandible.

Effectiveness of individualized 3D titanium-printed Orthognathic osteotomy guides and custom plates

BackgroundComputer-aided design/manufacturing (CAD/CAM) technology was developed to improve surgical accuracy and minimize errors in surgical planning and orthognathic surgery. However, its accurate implementation during surgery remains a challenge. Hence, we compared the accuracy and stability of conventional orthognathic surgery and the novel modalities, such as virtual simulation and three-dimensional (3D) titanium-printed customized surgical osteotomy guides and plates.MethodsThis prospective study included 12 patients who were willing to undergo orthognathic surgery. The study group consisted of patients who underwent orthognathic two-jaw surgery using 3D-printed patient-specific plates processed by selective laser melting and an osteotomy guide; orthognathic surgery was also performed by the surgeon directly bending the ready-made plate in the control group. Based on the preoperative computed tomography images and intraoral 3D scan data, a 3D virtual surgery plan was implemented in the virtual simulation module, and the surgical guide and bone fixation plate were fabricated. The accuracy and stability were evaluated by comparing the results of the preoperative virtual simulation (T0) to those at 7 days (T1) and 6 months (T2) post-surgery.ResultThe accuracy (ΔT1‒T0) and stability (ΔT2‒T1) measurements, using 11 anatomical references, both demonstrated more accurate results in the study group. The mean difference of accuracy for the study group (0.485 ± 0.280 mm) was significantly lower than in the control group (1.213 ± 0.716 mm) (P < 0.01). The mean operation time (6.83 ± 0.72 h) in the control group was longer than in the study group (5.76 ± 0.43 h) (P < 0.05).ConclusionThis prospective clinical study demonstrated the accuracy, stability, and effectiveness of using virtual preoperative simulation and patient-customized osteotomy guides and plates for orthognathic surgery.

Advanced Imaging Integration for Catheter Ablation of Ventricular Tachycardia.

Imaging plays a crucial role in the therapy of ventricular tachycardia (VT). We offer an overview of the different methods and provide information on their use in a clinical setting. The use of imaging in VT has progressed recently. Intracardiac echography facilitates catheter navigation and the targeting of moving intracardiac structures. Integration of pre-procedural CT or MRI allows for targeting the VT substrate, with major expected impact on VT ablation efficacy and efficiency. Advances in computational modeling may further enhance the performance of imaging, giving access to pre-operative simulation of VT. These advances in non-invasive diagnosis are increasingly being coupled with non-invasive approaches for therapy delivery. This review highlights the latest research on the use of imaging in VT procedures. Image-based strategies are progressively shifting from using images as an adjunct tool to electrophysiological techniques, to an integration of imaging as a central element of the treatment strategy.

Preoperative Novel Magnetic Resonance Fusion Imaging for Carotid Endarterectomy Patients with Contrast Contraindications: A Pilot Study

For carotid endarterectomy (CEA) patients with renal dysfunction and allergies to contrast media, we developed a preoperative novel method of noncontrast 3-dimensional magnetic resonance fusion imaging (NC-3DMRFI) which could describe well blood vessels, plaques, and bony structures even in surgical position. In this study, we examined the usefulness of this method. We extracted noncontrast magnetic resonance images of bones, blood vessels, and plaques to create a 3-dimensionalusion image. An image acquired in the normal position and another in the surgical position during CEA were used to create a fusion image. We compared the fusion imaging results with the intraoperative findings of 6 patients with contrast contraindications received CEA. Preoperative NC-3DMRFI could clearly show the positions of the carotid bifurcation, the distal end of plaque, and the bony structure in 5 of the 6 cases. Intraoperative findings and preoperative fusion imaging results were comparable in all cases where fusion images could be created. The fusion imaging in the surgical position during CEA was useful for preoperative examination, and the surgical space could be secured in the case of a high cervical location. This pilot study showed our novel NC-3DMRFI method is useful for preoperative simulation in CEA, especially in patients with renal dysfunction and allergies to contrast media.

Influence of preoperative simulation on the reduction quality and clinical outcomes of open reduction and internal fixation for complex proximal humerus fractures

PurposeProximal humerus fractures (PHFs) are common. With the development of locking plates, open reduction and internal fixation (ORIF) of the proximal humerus can provide excellent clinical outcomes. The quality of fracture reduction is crucial in the locking plate fixation of proximal humeral fractures. The purpose of this study was to determine the impact of 3-dimensional (3D) printing technology and computer virtual technology assisted preoperative simulation on the reduction quality and clinical outcomes of 3-part and 4-part proximal humeral fractures.MethodA retrospective comparative analysis of 3-part and 4-part PHFs undergoing open reduction internal fixation was performed. Patients were divided into 2 groups according to whether computer virtual technology and 3D printed technology were used for preoperative simulation: the simulation group and the conventional group. Operative time, intraoperative bleeding, hospital stay, quality of fracture reduction, Constant scores, American Society for Shoulder and Elbow Surgery (ASES) scores, shoulder range of motion, complications, and revision surgeries were assessed.ResultsThis study included 67 patients (58.3%) in the conventional group and 48 patients (41.7%) in the simulation group. The patient demographics and fracture characteristics were comparable in these groups. Compared with the conventional group, the simulation group had shorter operation time and less intraoperative bleeding (P < 0.001, both). Immediate postoperative assessment of fracture reduction showed a higher incidence of greater tuberosity cranialization of < 5 mm, neck-shaft angle of 120° to 150°, and head shaft displacement of < 5 mm in the simulation group. The incidence of good reduction was 2.6 times higher in the simulation group than in the conventional group (95% CI, 1.2–5.8). At the final follow-up, the chance of forward flexion > 120° (OR 5.8, 95% CI 1.8–18.0) and mean constant score of > 65 (OR 3.4, 95% CI 1.5–7.4) was higher in the simulation group than the conventional group, as well as a lower incidence of complications in the simulation group was obtained (OR 0.2, 95% CI 0.1–0.6).ConclusionsThis study identified that preoperative simulation assisted by computer virtual technology and 3D printed technology can improve reduction quality and clinical outcomes in treatment of 3-part and 4-part PHFs.

Clinical Application of Personalized Digital Surgical Planning and Precise Execution for Severe and Complex Adult Spinal Deformity Correction Utilizing 3D Printing Techniques.

(1) Background: The three-dimensional printing (3DP) technique has been reported to be of great utility in spine surgery. The purpose of this study is to report the clinical application of personalized preoperative digital planning and a 3DP guidance template in the treatment of severe and complex adult spinal deformity. (2) Methods: eight adult patients with severe rigid kyphoscoliosis were given personalized surgical simulation based on the preoperative radiological data. Guidance templates for screw insertion and osteotomy were designed and manufactured according to the planning protocol and used during the correction surgery. The perioperative, and radiological parameters and complications, including surgery duration, estimated blood loss, pre- and post-operative cobb angle, trunk balance, and precision of osteotomy operation with screw implantation were collected retrospectively and analyzed to evaluate the clinical efficacy and safety of this technique. (3) Results: Of the eight patients, the primary pathology of scoliosis included two adult idiopathic scoliosis (ADIS), four congenital scoliosis (CS), one ankylosing spondylitis (AS), and one tuberculosis (TB). Two patients had a previous history of spinal surgery. Three pedicle subtraction osteotomies (PSOs) and five vertebral column resection (VCR) osteotomies were successfully performed with the application of the guide templates. The main cobb angle was corrected from 99.33° to 34.17°, and the kyphosis was corrected from 110.00° to 42.00°. The ratio of osteotomy execution and simulation was 97.02%. In the cohort, the average screw accuracy was 93.04%. (4) Conclusions: The clinical application of personalized digital surgical planning and precise execution via 3D printing guidance templates in the treatment of severe adult rigid deformity is feasible, effective, and easily generalizable. The preoperative osteotomy simulation was executed with high precision, utilizing personalized designed guidance templates. This technique can be used to reduce the surgical risk and difficulty of screw placement and high-level osteotomy.

Preoperative simulation results and intraoperative image fusion guidance for transjugular intrahepatic portosystemic shunt placement: a feasibility study of nineteen patients.

The purpose is to evaluate the feasibility and efficacy of preoperative simulation results and intraoperative image fusion guidance during transjugular intrahepatic portosystemic shunt (TIPS) creation. Nineteen patients were enrolled in the present study. The three-dimensional (3D) structures of the bone, liver, portal vein, inferior vena cava, and hepatic vein in the contrast-enhanced computed tomography (CT) scanning area were reconstructed in the Mimics software. The virtual Rosch-Uchida liver access set and the VIATORR stent model were established in the 3D Max software. The puncture path from the hepatic vein to the portal vein and the release position of the stent were simulated in the Mimics and 3D Max software, respectively. The simulation results were exported to Photoshop software, and the 3D reconstructed top of the liver diaphragm was used as the registration point to fuse with the liver diaphragmatic surface of the intraoperative fluoroscopy image. The selected portal vein system fusion image was overlaid on the reference display screen to provide image guidance during the operation. As a control, the last 19 consecutive cases of portal vein puncture under the guidance of conventional fluoroscopy were analyzed retrospectively, including the number of puncture attempts, puncture time, total procedure time, total fluoroscopy time, and total exposure dose (dose area product). The average time of preoperative simulation was about 61.26 ± 6.98 minutes. The average time of intraoperative image fusion was 6.05 ± 1.13 minutes. The median number of puncture attempts was not significantly different between the study group (n = 3) and the control group (n = 3; P = 0.175). The mean puncture time in the study group (17.74 ± 12.78 min) was significantly lower than that in the control group (58.32 ± 47.11 min; P = 0.002). The mean total fluoroscopy time was not significantly different between the study group (26.63 ± 12.84 min) and the control group (40.00 ± 23.44 min; P = 0.083). The mean total procedure time was significantly lower in the study group (79.74 ± 37.39 min) compared with the control group (121.70 ± 62.24 min; P = 0.019). The dose area product of the study group (220.60 ± 128.4 Gy. cm2) was not significantly different from that of the control group (228.5 ± 137.3 Gy. cm2; P = 0.773). There were no image guidance-related complications. The use of preoperative simulation results and intraoperative image fusion to guide a portal vein puncture is feasible, safe, and effective when creating a TIPS. The method is cheap and may improve portal vein puncture, which may be valuable for hospitals lacking intravascular ultrasound and digital subtraction angiography (DSA) equipment equipped with a CT-angiography function.

Application of Virtual and Augmented Reality Technology in Hip Surgery: Systematic Review.

Virtual and augmented reality (VAR) represents a combination of current state-of-the-art computer and imaging technologies and has the potential to be a revolutionary technology in many surgical fields. An increasing number of investigators have developed and applied VAR in hip-related surgery with the aim of using this technology to reduce hip surgery-related complications, improve surgical success rates, and reduce surgical risks. These technologies are beginning to be widely used in hip-related preoperative operation simulation and training, intraoperative navigation tools in the operating room, and postoperative rehabilitation. With the aim of reviewing the current status of virtual reality (VR) and augmented reality (AR) in hip-related surgery and summarizing its benefits, we discussed and briefly described the applicability, advantages, limitations, and future perspectives of VR and AR techniques in hip-related surgery, such as preoperative operation simulation and training; explored the possible future applications of AR in the operating room; and discussed the bright prospects of VR and AR technologies in postoperative rehabilitation after hip surgery. We searched the PubMed and Web of Science databases using the following key search terms: ("virtual reality" OR "augmented reality") AND ("pelvis" OR "hip"). The literature on basic and clinical research related to the aforementioned key search terms, that is, studies evaluating the key factors, challenges, or problems of using of VAR technology in hip-related surgery, was collected. A total of 40 studies and reports were included and classified into the following categories: total hip arthroplasty, hip resurfacing, femoral neck fracture, pelvic fracture, acetabular fracture, tumor, arthroscopy, and postoperative rehabilitation. Quality assessment could be performed in 30 studies. Among the clinical studies, there were 16 case series with an average score of 89 out of 100 points (89%) and 1 case report that scored 81 (SD 10.11) out of 100 points (81%) according to the Joanna Briggs Institute Critical Appraisal Checklist. Two cadaveric studies scored 85 of 100 points (85%) and 92 of 100 points (92%) according to the Quality Appraisal for Cadaveric Studies scale. VR and AR technologies hold great promise for hip-related surgeries, especially for preoperative operation simulation and training, feasibility applications in the operating room, and postoperative rehabilitation, and have the potential to assist orthopedic surgeons in operating more accurately and safely. More comparative studies are necessary, including studies focusing on clinical outcomes and cost-effectiveness.

Simulation and navigation techniques in segmentectomy for lung cancer

: The diagnostic imaging technology for lung nodules has improved because of advances in computed tomography (CT) equipment. Therefore, surgical resections have increased for small-sized lung cancers or low-grade lung cancers with ground-glass opacity (GGO) that are not detected on chest radiographs. A recent Japanese prospective randomized study of segmentectomy versus standard lobectomy for small-sized lung cancer revealed better overall survival (OS) in the segmentectomy group, which supports segmentectomy for lung cancer patients. However, this prospective trial showed that postoperative recurrences were more frequent in the segmentectomy group than in the lobectomy group. In clinical practice, intentional segmentectomy for the lung has been indicated for lung cancer patients as several retrospective studies have shown favorable outcomes. The usefulness of a three-dimensional (3D) understanding of segmental anatomy has been reported, and new complex segmentectomies have been developed using 3D simulation. Advances in 3D-CT technology and simulation software provide precise preoperative simulation for surgical procedures that enable understanding of complex bronchovascular anatomy and 3D measurement of the surgical margin. A precise 3D simulation allows surgeons to perform safer complex segmentectomies. Hence, we can expect a better postoperative quality of life and improved survival by reducing the amount of resected parenchyma. We reviewed the expanding indications for lung segmentectomy and the growing demand for 3D simulation technology, including its advantages and limitations. We believe that this field will develop further as technology continues to advance.