Understanding stratification and turnover dynamics of a tropical lake using extensive field observations and 3D hydrodynamic simulations.

The stratification and turnover dynamics of a tropical lake were evaluated using field observations and 3D hydrodynamic simulations. Located in the Philippines, Sampaloc Lake is a 104-ha and 27-m deep volcanic crater lake with enclosed watershed, which is at risk of the impacts of intensive aquaculture, rapid urbanization and climate change. Temperature, dissolved oxygen (DO) and chlorophyll-a (Chl-a) were measured at seven sampling stations using a multiprobe. Kruskal-Wallis test revealed that the three parameters are not significantly different among stations, indicating that one sampling station can represent the water quality of the whole lake. Schmidt's Stability Index (SSI) and thermocline strength, together with DO and Chl-a gradients decreased from October 2022 (stratified) to January 2023 (turnover). After successfully verifying the 3D numerical model, sensitivity analyses of water temperature to varying weather, together with particle tracking simulations, were implemented to determine the timing of isothermal state, upwelling, partial mixing, and full turnover. Compared to air temperature, variations in wind speed have more pronounced effects on the delay or progression of isothermal conditions in the lake based on SSI, Lake Number and Wedderburn Number. Isothermal conditions do not necessarily coincide with the timing of full turnover, with the latter being delayed by two days than the former, on average. Results revealed that full turnover can occur several weeks earlier with the decrease in AT and increase in WS. This study can advance the understanding of thermal and turnover dynamics of stratified tropical lakes, leading to better management of the water quality of these water bodies.

An in-vitro three-dimensional surgical simulation technique to predict tibial tunnel length in transtibial posterior cruciate ligament reconstruction.

BACKGROUND: During the transtibial posterior cruciate ligament (PCL) reconstruction, drilling depth excessively longer than the tibial tunnel length (TTL) is an important reason to cause popliteal neurovascular bundle injury when preparing the tibial tunnel. This study aims to develop an in-vitro three-dimensional surgical simulation technique to determine the TTL in anteromedial (AM) and anterolateral (AL) approaches. METHODS: A total of 63 knees' 3-dimensional (3D) computed tomography models were included in this study. The SuperImage system was used to reconstruct the 3D knee model and locate the tibial PCL site. The established 3D knee model and the coordinates of the tibial PCL site were imported into Rhinoceros 3D modeling software to simulate AM and AL tibial tunnel approaches with different tibial tunnel angles (TTA). The TTL and the tibial tunnel height (TTH) were measured in this study. RESULTS: In AM and AL tibial tunnel approaches, the TTL showed a strong correlation with the TTA (for AM: r = 0.758, p < 0.001; for AL: r = 0.727, p < 0.001). The best fit equation to calculate the TTL based on the TTA was Y = 1.04X + 14.96 for males in AM approach, Y = 0.93X + 17.76 for males in AL approach, Y = 0.92X + 14.4 for females in AM approach, and Y = 0.94X + 10.5 for females in AL approach. CONCLUSION: Marking the TTL on the guide pin or reamer could help to avoid the drill bit over-penetrated into the popliteal space to damage the neurovascular structure.

Computational study of effect of hybrid nanoparticles on hemodynamics and thermal transfer in ruptured arteries with pathological dilation.

The intended research aims to explore the convection phenomena of a hybrid nanofluid composed of gold and silver nanoparticles. This research is novel and significant because there is a lack of existing studies on the flow behavior of hybrid nanoparticles with important physical properties of blood base fluids, especially in the case of sidewall ruptured dilated arteries. The implementation of combined nanoparticles rather than unadulterated nanoparticles is one of the most crucial elements in boosting the thermal conduction of fluids. The research methodology encompasses the utilization of advanced bio-fluid dynamics software for simulating the flow of the nanofluid. The physical context elucidates the governing equations of momentum, mass, momentum, and energy in terms of partial differential equations. The results are displayed in both tabular and graphical forms to demonstrate the numerical and graphical solutions. The effect of physical parameters on velocity distribution is illustrated through graphs. Furthermore, the study's findings are unique and original, and these computational discoveries have not been published by any researcher before. The finding implies that utilizing hybrid nanoparticles as drug carriers holds great promise in mitigating the effects of blood flow, potentially enhancing drug delivery, and minimizing its impact on the body.

Simply designed robotic combined subsegmentectomy for a lesion in the left S10 via a posterior approach.

Segmentectomies involving the posterior basal segment (S10) of the lower lobe present a challenging surgical procedure due to anatomical complexities, especially when lesions extend towards the lateral basal segment (S9). We introduce a combined subsegmentectomy technique via a posterior approach for a lesion situated between S9b and S10b, which preserves subsegmental branches that do not affect the resection margin of the tumour and facilitates intersegmental division without extending dissection into the interlobar region. This technique, the goal of which is to reduce the extent of dissection and complex stapling, is expected to minimize pulmonary complications and intrathoracic adhesions without compromising oncological outcomes. By potentially mitigating challenges in an ipsilateral reoperation, this approach offers a valuable alternative for managing second lung cancers.

Latarjet procedure restores range of motion at six months postoperatively: a prospective cohort study utilizing motion capture analysis.

BACKGROUND: There is a common concern that range of motion (ROM) is negatively affected by the Latarjet procedure. We hypothesize that the Latarjet procedure results in full recuperation of ROM postoperatively and significantly improved patient reported outcome measures. METHODS: Patient data were prospectively collected from a randomized controlled trial to analyze outcomes after open Latarjet procedure. Inclusion criteria involved a minimum follow-up of six months and unilateral shoulder instability. Study outcome was assessed by postoperative ROM at six months postoperatively and compared to the preoperative ROM of the ipsilateral shoulder as well as the ROM of the unaffected contralateral shoulder. All ROM measurements were performed utilizing a motion capture system to ensure consistent and reliable measurements. RESULTS: The study included a total of 84 patients. ROM was measured in external rotation with the shoulder adducted (ER1), external rotation with the shoulder abducted 90 degrees (ER2), internal rotation with the arm abducted 90 degrees (IR2), and active forward elevation (AE). The average difference in ROM between the operated arm vs. the contralateral healthy arm at six months postoperatively was 3.4 degrees in ER1 (p=0.19), 4.2 degrees in ER2 (p=0.086), 2.2 degrees in IR2 (p=0.36), and 2.4 degrees in AE (p=0.045). Sub-analysis of patients with and without sling use revealed no significant difference in ROM between the operated shoulder and contralateral shoulder at six months in either group, with the exception of ER2 in the sling group. In this latter group, ROM was 71 degrees in the operated arm and 79 degrees in the contralateral arm (p=0.0094). Average preoperative pain score was 25.7 (21.4-30.1, 95%CI) vs. 13.0 postoperatively at six months (9.50-16.5, 95%CI) (p <0.00001). Average preoperative SANE instability was 42.9 (38.4-47.3, 95%CI) vs. 86.2 postoperatively at six months (83.6-88.7, 95%CI) (p <0.00001). Average preoperative Rowe score was 38.5 (34.3-42.7, 95%CI) vs. 84.3 at six postoperative months (81.1-87.4, 95%CI) (p<0.00001). CONCLUSIONS: Latarjet procedure performed for anterior instability utilizing a capsular repair result in complete ROM recovery in ER1, ER2, and IR2 at six months postoperatively, with only a slight discrepancy in active elevation. Sling use after the Latarjet procedure results in no benefit over postoperative recovery without the use of a sling. Sling use negatively affects the ROM in ER2, taking as reference the contralateral arm of the same patient, when compared to patients that did not use a sling postoperatively.

Driving factors for distribution and transformation of heavy metals speciation in a zinc smelting site.

Heavy metal pollution at an abandoned smelter pose a significant risk to environmental health. However, remediation strategies are constrained by inadequate knowledge of the polymetallic distribution, speciation patterns, and transformation factors at these sites. This study investigates the influence of soil minerals, heavy metal occurrence forms, and environmental factors on heavy metal migration behaviors and speciation transformations. X-ray diffraction analysis revealed that the minerals associated with heavy metals are mainly hematite, franklinite, sphalerite, and galena. Sequential extraction results suggest that lead and zinc are primarily present in the organic-sulfide fractions (F4) and residual form (F5) in the soil, accounting for over 70% of the total heavy metal content. Zinc displayed greater instability in carbonate-bound (16%) and exchangeable (2%) forms. The migration and diffusion patterns of heavy metals in the subsurface environment were visualized through the simulation of labile state heavy metals, demonstrating high congruence with groundwater pollution distribution patterns. The key environmental factors influencing heavy metal stable states (F4 and F5) were assessed by integrating random forest models and redundancy analysis. Primary factors facilitating Pb transformation into stable states were available phosphorus, clay content, depth, and soil organic matter. For Zn, the principal drivers were Mn oxides, soil organic matter, clay content, and inorganic sulfur ions. These findings enhance understanding of the distribution and transformation of heavy metal speciation and can provide valuable insights into controlling heavy metal pollution at non-ferrous smelting sites.

Capturing differences in perception and aesthetic judgment of live or medially presented music: development of a self-report instrument.

Nowadays there are multiple ways to perceive music, from attending concerts (live) to listening to recorded music through headphones (medial). In between there are many mixed modes, such as playback performances. In empirical music research, this plurality of performance forms has so far found little recognition. Until now no measuring instrument has existed that could adequately capture the differences in perception and aesthetic judgment. The purpose of our empirical investigation was to capture all dimensions relevant to such an assessment. Using 3D-simulations and dynamic binaural synthesis, various live and medial situations were simulated. A qualitative survey was conducted at the Department of Audio Communication of the Technical University of Berlin (TU Berlin). With the help of the repertory grid technique, a data pool of approximately 400 attribute pairs was created and individual rating data were collected. Our first study served to create a semantic differential. In a second study, this semantic differential was evaluated. The development of the semantic differential was carried out by first using a mixed-method approach to qualitative analysis according to grounded theory. Thereafter, a principal component analysis reduced the attribute pairs to 67 items in four components. The semantic differential consists of items concerning acoustic, visual and audio-visual interaction as well as items with an overarching assessment of the stimuli. The evaluation study, comprising 45 participants (23 male and 22 female, M = 42.56 years, SD = 17.16) who rated 12 stimuli each, reduced the items to 61 and resulted in 18 subscales and nine single items. Because the survey used simulations, the social component may be underrepresented. Nevertheless, the questionnaire we created enables the evaluation of music performances (especially for classical concerts) in a new scope, thus opening many opportunities for further research. For example, in a live concert context, we observed not only that seating position influences the judgment of sound quality but also that visual elements influence immersion and felt affect. In the future, the differential could be reviewed for a larger stimulus pool, extended or used modularly for different research questions.

Enhancing Bone Implants: Magnesium-Doped Hydroxyapatite for Stronger, Bioactive, and Biocompatible Applications.

Hydroxyapatite (HAp) with the chemical formula Ca10(PO4)6(OH)2 is an inorganic material that exhibits morphology and composition similar to those of human bone tissues, making it highly desirable for bone regeneration applications. As one of the most biocompatible materials currently in use, HAp has undergone numerous attempts to enhance its mechanical strength. This research focuses on investigating the influence of magnesium (Mg) incorporation on the structural and mechanical properties of synthesized magnesium-doped hydroxyapatite (MgHAp) samples. Apart from its biocompatibility, Mg possesses a density and elasticity comparable to those of human bone. Therefore, incorporating Mg into HAp can be pivotal for improving bone formation. Previous studies have not extensively explored the structural changes induced by Mg substitution in HAp, which motivated us to revisit this issue. Hydrothermal synthesis technique was used to synthesize MgHAp samples with varying molar concentrations (x = 0, 0.5, 1.0, and 1.5). Theoretical simulation of HAp and MgHAp for obtaining 3D structures has been done, and theoretical X-ray diffraction (XRD) data have been compared with the experimental XRD data. Rietveld analysis revealed the alteration and deviation of lattice parameters with an increase in the Mg content, which ultimately affect the structure as well the mechanical properties of prepared samples. The findings revealed an increase in compressive stress and fracture toughness as the Mg concentration in the composition increased. Furthermore, using a finite-element analysis technique and modeling of the mechanical testing data, the von Mises stress distribution and Young's modulus values were calculated, demonstrating the similarity of the prepared samples to human cortical bone. Biocompatibility assessments using NIH-3T3 fibroblast cells confirmed the biocompatible and bioactive nature of the synthesized samples. MgHAp exhibits great potential for biomedical applications in the dental, orthopedic, and tissue engineering research fields.

Prevention of Cerebrospinal Fluid Leakage in the Anterior Transpetrosal Approach.

Background: The anterior transpetrosal approach (ATPA) is effective for reaching petroclival lesions, and it allows for complications such as impaired venous return and neuropathy to be resolved. However, there is still room for improvement regarding cerebrospinal fluid (CSF) leakage. Here, we aim to focus on describing specific preoperative, intraoperative, and postoperative countermeasures for preventing CSF leakage when using the ATPA. Methods: Eleven patients treated using the ATPA, who were treated at our hospital from June 2019 to February 2023, were included in this descriptive study. Preoperatively, we performed a 3D simulation of the opened air cells. Then, we classified patterns of dural closure into three types based on intradural manipulation and whether it involved opened air cells or not. Intraoperatively, we performed a dural closure that included the use of more-watertight sutures (DuraGen®) and an endoscope. Furthermore, temporal bone air cell volume measurements were performed to confirm the correlation between the volume and factors related to CSF leakage. Results: No postoperative CSF leakage was observed in any patient. The temporal bone air cell volumes significantly corelated with the air cells of the petrous apex, the high-risk tract in the petrous apex, and postoperative fluid collection in mastoid air cells. Conclusions: We have described countermeasures for preventing CSF leakage when using the ATPA. Preoperative simulations and the use of multiple-layered dural reconstructions with endoscopes could be considered more reliable methods for preventing CSF leakage when using the ATPA.

A 3D-simulation study of the deformation, tension, and stress of 3D-printed and conventional denture base materials after immersion in artificial saliva.

INTRODUCTION: The worldwide application of digital technology has presented dentistry with transformative opportunities. The concept of digital dentures, incorporating computer-aided design (CAD) and computer-aided manufacturing (CAM) techniques, holds the promise of improved precision, customization, and overall patient satisfaction. However, the shift from traditional dentures to their digital counterparts should not be taken lightly, as the intricate interplay between oral physiology, patient comfort, and long-term durability requires thorough examination.

Morphological Aesthetics Assessment of the Predicted 3D Simulation Results and the Actual Results of Breast Augmentation.

BACKGROUND: Although three-dimensional (3D) simulations are becoming more common in preoperative breast augmentation planning, this does not necessarily imply that the simulated results are highly accurate. OBJECTIVES: We aimed to evaluate the accuracy of the 3D simulation technique by comparing the differences in breast morphology between the 3D prediction model and the actual results. METHODS: The simulation and actual postoperative results of 103 patients who underwent breast augmentation were analyzed retrospectively. Therefore, a 3D model was created, and the parameters of line spacing, nipple position, breast projection, surface area, and volume were evaluated. Furthermore, consider the difference in chest circumferences and breast volume. RESULTS: In comparison with the simulation results, the actual results had a mean increase in the nipple to the inframammary fold (N-IMF) of 0.3 cm (P < 0.05) and a mean increase in basal breast width (BW) of 0.3 cm (P < 0.001), a difference that was not statistically significant in patients with larger breast volumes. There was a significant difference in the mean upper and lower breast volume distribution between simulated and actual breasts (upper pole 52.9% vs. 49.2%, P < 0.05, and lower pole 47.1% vs. 50.8%, P < 0.001). However, it was not statistically significant in patients with larger chest circumferences. CONCLUSIONS: Our study shows that 3D simulation has uncertainties related to the patient's chest circumference and breast volume. Therefore, these two critical factors must be considered when using simulation assessment in preoperative planning. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effectiveness of SplashGuard Caregiver prototype in reducing the risk of aerosol transmission in intensive care unit rooms of SARS-CoV-2 patients: a prospective and simulation study.

BACKGROUND: The contagiousness of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is known to be linked to the emission of bioaerosols. Thus, aerosol-generating procedures (AGPs) could increase the risk of infection among healthcare workers (HCWs). AIM: To investigate the impact of an aerosol protection box, the SplashGuard Caregiver (SGGC) with suction system, by direct analysis of the presence of viral particles after an AGP, and by using the computational fluid dynamics (CFD) simulation method. METHODS: This prospective observational study investigated HCWs caring for patients with SARS-CoV-2 admitted to an intensive care unit (ICU). Rooms were categorized as: SGCG present and SGCG absent. Virus detection was performed through direct analysis, and using a CFD model to simulate the movement dynamics of airborne particles produced by a patient's respiratory activities. FINDINGS: Of the 67 analyses performed, three samples tested positive on quantitative polymerase chain reaction: one of 33 analyses in the SCCG group (3%) and two of 34 analyses in the non-SGCG group (5.9%). CFD simulations showed that: (1) reduction of the gaps of an SGCG could decrease the number of emitted particles remaining airborne within the room by up to 70%; and (2) positioning HCWs facing the opposite direction to the main air flow would reduce their exposure. CONCLUSIONS: This study documented the presence of SARS-CoV-2 among HCWs in a negative pressure ICU room of an infected patient with or without the use of an SGCG. The simulation will help to improve the design of the SGCG and the positioning of HCWs in the room.

A robotic left S1+2c subsegmentectomy using preoperative simulation.

Although there are reports describing segmentectomy by a robotic approach, reports describing robotic subsegmentectomy are rare because this procedure requires more precise anatomical knowledge and exposure of subsegmental pulmonary vessels and bronchi. However, the robotic approach has several advantages, including a high-definition 3-dimensional surgical view and precise motion without tremor, which may allow us to perform the subsegmentectomy more easily. Considering these advantages of the robotic approach, we successfully performed a robotic left S1+2c segmentectomy with a short console time and a good postoperative course. We present the surgical steps of this procedure. In addition, the preoperative simulation method was useful to ensure a sufficient surgical margin. Because the robotic approach lacked tactile feedback, it was difficult to locate the target tumour intraoperatively by palpation compared with the conventional thoracoscopic approach. Finally, in this case, we obtained an adequate surgical margin using this preoperative simulation method.

Primera colocación del dispositivo AMPLATZER™, Amulet™ para cierre de orejuela en Costa Rica utilizando Heart Navigator / First placement of the AMPLATZER™ Amulet™ device for appendage closure in Costa Rica using Heart Navigator

RESUMEN El cierre de la orejuela izquierda mediante un dispositivo facilita la prevención de un accidente cerebrovascular en pacientes con antecedente de fibrilación auricular no valvular y contraindicación para el uso de medicamentos anticoagulantes. Este artículo presenta dos casos de pacientes con historia de fibrilación auricular en el Hospital Calderón Guardia, ambos con el antecedente de sangrado digestivo y contraindicación para la anticoagulación, en los que se logró el cierre de la orejuela izquierda mediante la colocación exitosa del dispositivo AmuletTM, utilizando TAC y Heart Navigator, técnicas de imagen que se están convirtiendo en el estándar de oro de muchos centros internacionales de referencia en cardiología intervencionista.

ABSTRACT Closure of the left atrial appendage with a device facilitates the prevention of stroke in patients with a history of nonvalvular atrial fibrillation and a contraindication to the use of anticoagulant medications. This article presents two cases of patients with a history of atrial fibrillation at the Calderón Guardia Hospital, both with a history of digestive bleeding and contraindication to anticoagulation, in whom closure of the left atrial appendage was achieved through successful placement of the AmuletTM device, using CT and Heart Navigator, imaging techniques that are becoming the gold standard in many international reference centers in interventional cardiology.

TT-TG distance decreases after open wedge distal femoral varization osteotomy in patients with genu valgum & patellar instability. A pilot 3D computed tomography simulation study.

BACKGROUND: Genu valgum is considered to be a risk factor for patellar instability. Correction of valgus alone or combined with a tibial tuberosity medialization has been described. However, changes occurring in the tibial tuberosity-trochlear groove (TT-TG) distance after a lateral distal femoral opening wedge osteotomy (LDF-OWO) are not known. PURPOSE: This study aimed to define changes in TT-TG distance with increasing amounts of valgus correction after LDF-OWO. METHODS: Three-Dimensional Computed Tomography (3D-CT) scans of six patients (two females and four males) aged between 19 and 35 years with genu valgum and patellar instability were analyzed. 3D models of femoral, tibial, and patellar bones were created with the advanced segment option of Mimics 21® software. An oblique lateral opening wedge osteotomy of the distal femur was simulated in 2-degree increments up to 12 degrees of varus opening. Change in TT-TG distance was measured in mm on 3D models of the knee. RESULTS: Compared to baseline without osteotomy, the TT-TG distance decreased significantly (p < 0.05) for all corrections from 2 to 12 degrees in 2° steps. The TT-TG distance decreased by an average of 1.7 mm for every 2 degrees of varus opening. CONCLUSION: Lateral opening wedge distal femoral osteotomy causes a decrease in TT-TG distance. The surgeon should be aware of the magnitude of this change (1.7 mm decrease for every 2° increment of valgus opening).

Three-Dimensional Simulation Training for Oncology Nurses to Address Pitfalls in Current Irrigation Strategy for Intravenous Ports: Repeated Measurements Study.

OBJECTIVE: We designed an interactive visual training course and three-dimensional (3-D) simulator for participants and used verified questionnaires as tool to evaluate the efficacy of the education course. DATA SOURCES: From August 2020 to December 2021, 159 nursing staff who received the interactive visual training course and completed validated questionnaires before and after the course were included. The efficacy of the course was evaluated by comparing the pre- and post-course questionnaires. CONCLUSION: The interactive visual training course, including maintenance lectures and practice with a 3-D simulator, improved consensus among the nursing staff and increased the willingness of oncology nurses to perform the proposed port irrigation procedure. IMPLICATIONS FOR NURSING PRACTICE: An implanted intravenous port cannot be directly seen by nursing staff and can only be identified through manual palpation. This lack of visibility may result in individual variations in port identification during daily practice, potentially leading to malpractice. To minimize these individual variations, we have designed an interactive visual training course. We used validated questionnaires before and after the course to analyze its efficacy in practical education.

Effectiveness of a 3D simulation tool to teach the designing of metal removable partial dentures: A mixed-method study.

INTRODUCTION: Acquiring insights into the framework design of metal-based removable partial dentures (mRPD) is a current challenge in dental education. The aim of the present study was to explore the effectiveness of a novel 3D simulation tool to teach designing mRPD by investigating the learning gain and the acceptance and motivation towards the tool of dental students. MATERIALS AND METHODS: A 3D tool based on 74 clinical scenarios was developed for teaching the design of mRPD. Fifty-three third year dental students were randomly divided into two groups, with the experimental group (n = 26) having access to the tool during 1 week while the control group (n = 27) had no access. Quantitative analysis was based on a pre- and post-test in order to evaluate the learning gain, technology acceptance and motivation towards using the tool. Moreover, qualitative data was collected by means of an interview and focus group to get additional insights into the quantitative results. RESULTS: Although the results showed a higher learning gain for students in the experimental condition, the study did not find a significant difference between both conditions based on quantitative results. However, during the focus groups, all students of the experimental group revealed that the 3D tool improved their understanding of mRPD biomechanics. Moreover, survey results revealed that students positively evaluated the perceived usefulness and ease of use of the tool and indicated to have the intention to use the tool in the future. Suggestions were made for a redesign (e.g. creating scenarios themselves) and further implementation of the tool (e.g. analysing the scenarios in pairs or small groups). CONCLUSION: First results of the evaluation of the new 3D tool for teaching the design framework of mRPD are promising. Further research based on the design-based research methodology is needed to investigate the effects of the redesign on motivation and learning gain.

A novel method of ultrasound-guided positive staining using indocyanine green fluorescence in laparoscopic anatomical liver resection of segments VII and VIII.

Background: Recently, in many Asian centers, laparoscopic anatomical liver resection (LALR) using the indocyanine green (ICG) fluorescence imaging technique has been increasingly applied in resecting hepatocellular carcinoma, even in colorectal liver metastases. However, LALR techniques have not been fully standardized, especially in right superior segments. Due to the anatomical position, prevailing positive staining using a PTCD (percutaneous transhepatic cholangial drainage) needle was superior to negative staining in right superior segments hepatectomy, while it was difficult to manipulate. Herein, we design a novel method of ICG-positive staining for LALR of right superior segments. Methods: Between April 2021 and October 2022, we retrospectively studied patients in our institute who underwent LALR of right superior segments using a novel method of ICG-positive staining, which comprised a customized puncture needle and an adaptor. Compared to the PTCD needle, the customized needle was not limited by the abdominal wall and could be punctured from the liver dorsal surface, which was more flexible to manipulate. The adapter was attached to the guide hole of the laparoscopic ultrasound (LUS) probe to ensure the precise puncture path of the needle. Guided by preoperative three-dimensional (3D) simulation and intraoperative laparoscopic ultrasound imaging, we punctured the transhepatic needle into the target portal vein through the adaptor and then slowly injected 5-10 ml of 0.025 mg/ml ICG solution into the vessel. LALR can be guided by the demarcation line under fluorescence imaging after injection. Demographic, procedural and postoperative data were collected and analyzed. Results: In this study, 21 patients underwent LALR of the right superior segments with ICG fluorescence-positive staining, and the procedures had a success rate of 71.4%. The average staining time was 13.0 ± 6.4 min, the operative time was 230.4 ± 71.7 min, R0 resection was 100%, the postoperative hospital stay was 7.1 ± 2.4 days, and no severe puncture complications occurred. Conclusions: The novel customized puncture needle approach seems to be feasible and safe for ICG-positive staining in LALR of right superior segments, with a high success rate and a short staining time.

An Innovative method for intraoperative guidance of nasal shape in rhinoplasty: Application of a convenient, sterilizable, patient-specific film model.

BACKGROUNDS: 3D simulation is increasingly used in rhinoplasty. However, during the operation, there is no tool to directly link the 3D simulation results with the intraoperative operation. Doctors rely on 3D simulation results only according to their intuition. Recently, the authors have discovered a simple, low-cost, and practical method for intraoperative assessment: a film model can be made according to the contour of the nose shape in its midsagittal view. The authors aimed to evaluate the effectiveness of the innovative method for intraoperative assessment of nasal shape in rhinoplasty. METHODS: Thirty-nine patients who underwent rhinoplasty for the first time between January 2019 and January 2021 were included in this study. All the patients confirmed ideal nasal shape based on preoperative three-dimensional photography (INOVA 3D-EX). In the guide group, procedures were based on guide of the film model and a picture of 3D simulation, and in the control group, procedures were performed based on the surgeon's intuition and a picture of 3D simulation. RESULTS: There were no statistical differences in basic data between the two groups before operation. Both groups showed a satisfactory correlation. Except for the columellar lobular angle, the ICC of nasal length, nasal depth, dorsum height, columella length, nasofrontal angle, nasorostral angle, and nasolabial angle were all stronger in the guide group than in the control group. CONCLUSION: This study demonstrates the usefulness of the nasal-shaped film model, which is made according to the contour of the nose shape in its midsagittal view. This approach is simple, low-cost, and practical.

Significant changes in lower limb alignment due to flexion and rotation-a systematic 3D simulation of radiographic measurements.

BACKGROUND: Many radiographic lower limb alignment  measurements are dependent on patients' position, which makes a standardised image acquisition of long-leg radiographs (LLRs) essential for valid measurements. The purpose of this study was to investigate the influence of rotation and flexion of the lower limb on common radiological alignment parameters using three-dimensional (3D) simulation. METHODS: Joint angles and alignment parameters of 3D lower limb bone models (n = 60), generated from computed tomography (CT) scans, were assessed and projected into the coronal plane to mimic radiographic imaging. Bone models were subsequently rotated around the longitudinal mechanical axis up to 15° inward/outward and additionally flexed along the femoral intercondylar axis up to 30°. This resulted in 28 combinations of rotation and flexion for each leg. The results were statistically analysed on a descriptive level and using a linear mixed effects model. RESULTS: A total of 1680 simulations were performed. Mechanical axis deviation (MAD) revealed a medial deviation with increasing internal rotation and a lateral deviation with increasing external rotation. This effect increased significantly (p < 0.05) with combined flexion up to 30° flexion (- 25.4 mm to 25.2 mm). With the knee extended, the mean deviation of hip-knee-ankle angle (HKA) was small over all rotational steps but increased toward more varus/valgus when combined with flexion (8.4° to - 8.5°). Rotation alone changed the medial proximal tibial angle (MPTA) and the mechanical lateral distal femoral angle (mLDFA) in opposite directions, and the effects increased significantly (p < 0.05) when flexion was present. CONCLUSIONS: Axial rotation and flexion of the 3D lower limb has a huge impact on the projected two-dimensional alignment measurements in the coronal plane. The observed effects were small for isolated rotation or flexion, but became pronounced and clinically relevant when there was a combination of both. This must be considered when evaluating X-ray images. Extension deficits of the knee make LLR prone to error and this calls into question direct postoperative alignment controls. LEVEL OF EVIDENCE: III (retrospective cohort study).