Three-Dimensional Computed Tomography of the Detoured Facial Artery: Variations and Implications for Nasojugal Groove Correction.

BACKGROUND: When performing filler injection procedures to the nasojugal groove, there is the risk of iatrogenic damage to the detoured facial artery. OBJECTIVE: To determine the 3-dimensional location of the detoured facial artery. MATERIALS AND METHODS: The branches of the facial arteries from 118 cadaveric hemifaces were scanned using computed tomography and reconstructed using the Mimics software program. RESULTS: Detoured facial arteries were found in 47 of the 118 hemifaces (39.8%). Two main arterial patterns were identified: in Type I (29 of 47 cases), there were both detoured and nasolabial trunks where the facial artery originated, whereas in Type II (18 of 47 cases), there was only a detoured trunk. The detoured trunk originated 32.0 ± 5.3 mm from the midsagittal line, 5.0 ± 2.8 mm from the occlusion plane, and 5.9 ± 3.5 mm below the skin layer; the inflection of the detoured trunk was located 30.0 ± 5.6 mm laterally, 26.2 ± 4.4 mm superiorly, and 5.7 ± 2.6 mm deep. The meeting point with the inferior orbital rim plane was located 17.1 ± 3.4 mm laterally, 43.4 ± 3.1 mm superiorly, and 2.8 ± 1.7 mm deep. CONCLUSION: The 3-dimensional location of the detoured facial artery as reported here will help clinicians to avoid iatrogenic damage when they are performing filler injection procedures.

Deployment of the Ophthalmic and Facial Angiosomes in the Upper Nose Overlaying the Nasal Bones.

BACKGROUND: Nasal filler placement is associated with a high risk of blindness. The arterial supply to the upper nose overlaying the nasal bones is poorly understood. OBJECTIVES: The aim of this study was to visualize and analyze the deployment of the ophthalmic and facial angiosomes in the upper nose to help prevent blindness following nasal filler injections. METHODS: The arterial systems of 62 cadaveric heads were filled with lead oxide contrast agent, and computed tomography (CT) images were acquired and reconstructed in 3 dimensions. RESULTS: Twenty-six of the cadaveric noses examined demonstrated clear CT images of the facial and ophthalmic angiosomes in the upper nose. The Type 1 upper nose (15.4%) is supplied by 2 independent ophthalmic angiosomes that communicate indirectly through a choke anastomosis. The Type 2 upper nose (38.5%) is supplied by 2 ophthalmic angiosomes with a true anastomosis between them. The Type 3 upper nose (46.1%) is supplied by both ophthalmic and facial angiosomes with true anastomoses across the dorsal midline. These true anastomoses are mediated by the radix arcade in 46% of the noses and involve the dorsal nasal artery in 65% of the cases. The anastomoses all cross the upper dorsal midline and are directly linked to the ophthalmic angiosome. CONCLUSIONS: The deployment and anastomosis of the facial and ophthalmic angiosomes in the upper nose fall into 3 major patterns. About 85% of the noses have true anastomotic arteries that cross the upper dorsal midline and are directly linked to the ophthalmic circulation. Dorsum filler injection poses a significant risk of blindness.

Three-Dimensional Computed Tomography Scanning of Temporal Vessels to Assess the Safety of Filler Injections.

BACKGROUND: Temple filler injection is one of the most common minimally invasive cosmetic procedures involving the face; however, vascular complications are not uncommon. OBJECTIVES: This study aimed to investigate the anatomy of the temporal vessels and provide a more accurate protocol for temple filler injection. METHODS: Computed tomography (CT) scans of 56 cadaveric heads injected with lead oxide were obtained. We then used Mimics software to construct 3-dimensional (3D) images of the temporal vessels described by a coordinate system based on the bilateral tragus and right lateral canthus. RESULTS: In the XOY plane, the superficial temporal artery (STA), middle temporal artery (MTA), zygomatico-orbital artery (ZOA), posterior branch of the deep temporal artery (PDTA), and lateral margin of the orbital rim divide the temple into 4 parts (A, B, C, and D). The probabilities of the STA, MTA, ZOA, and PDTA appearing in parts A, B, C, and D were 30.73%, 37.06%, 39.48%, and 77.18%, respectively. In 3D images, these vessels together compose an arterial network that is anastomosed with other vessels, such as the external carotid, facial, and ocular arteries. CONCLUSIONS: 3D CT images can digitally elucidate the exact positions of temporal vessels in a coordinate system, improving the safety of temple filler injections in a clinical setting.

A Prospective Study of Breast Morphological Changes and the Correlative Factors After Periareolar Dual-Plane Augmentation Mammaplasty with Anatomic Implant.

BACKGROUND: Dual-plane breast augmentation is a popular cosmetic procedure. However, objective evaluations on the effects of dual-plane breast augmentation on breast morphology are lacking. This study evaluated the breast morphological changes and correlative factors after dual-plane anatomic implant augmentation with a periareolar incision via a Vectra 3-dimensional (3D) scanning technique. METHODS: The dynamic changes in linear distance, breast projection, nipple position, and breast volume and surface over time (preoperatively; 1 month, 3 months, 6 months, and 12 months after surgery) were analyzed in 21 patients with the Vectra 3D scanning technique. In another group of 65 patients, the influence of the implant parameters and tissue characteristics of the patients on breast morphological changes were evaluated. RESULTS: The breast measurements changed significantly up to 6 months postoperatively and remained stable thereafter. The inframammary fold dropped by 0.8 cm at 1 month postoperatively and by 0.5 cm in the following 11 months. The preoperative implant volume and a lower pole skin elasticity lead to an increase in the nipple-to-inframammary fold distance. Compared with the expected values, the final volume was 10.9% smaller, and the projection was 25% smaller. Both the reduced volume and projection were correlated with the implant parameters and preoperative values. The nipple level was slightly elevated by approximately 0.8 cm. CONCLUSIONS: This study provides objective information regarding the breast morphological changes and correlative factors after dual-plane breast augmentation. These information may help to further understand the operation effects of dual-plane breast augmentation and to guide medical practice. LEVEL OF EVIDENCE IV: 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 .

Three-Dimensional Computed Tomographic Study on the Periorbital Branches of the Ophthalmic Artery: Arterial Variations and Clinical Relevance.

BACKGROUND: Filler injection is a popular cosmetic procedure, but it can entail vascular complications. Periorbital injections have the highest risk within the entire injection area. OBJECTIVES: The authors sought to systematically screen for periorbital arterial variations prior to treatment. METHODS: The external carotid arteries of 10 cadaveric heads were infused with adequate lead oxide contrast. The facial and superficial temporal arteries of another 11 cadaveric heads were injected with the contrast in sequential order. Computed tomography (CT) scanning was performed after injection of contrast, and 3-dimensional (3D) CT scans were reconstructed using validated algorithms. RESULTS: Three types of periorbital blood vessels were found to derive from the ophthalmic artery, including 30% directly originating from the ophthalmic artery, 65% originating from its trochlear branch, and 5% originating from its supraorbital branch. In the forehead, the ophthalmic artery, originating from the internal carotid arteries, formed anastomoses between the frontal branch of the superficial temporal artery, originating from the external carotid artery, with the deep and superficial branches of the supratrochlear and supraorbital arteries, respectively. The lateral orbit and malar plexus can be classified into 4 types based on the trunk artery: the zygomatic orbital artery (27%), the transverse facial artery (23%), the premasseteric branch of the facial artery (19%), and all 3 contributing equally (31%). CONCLUSIONS: Postmortem 3D CT can map periorbital arterial variations. The branching pattern of the ophthalmic artery, the ophthalmic angiosome in the forehead, and the distribution of the lateral orbit and malar plexus were identified at high resolution to guide clinical practice.

Are computer numerical control (CNC)-manufactured patient-specific metal templates available for posterior thoracic pedicle screw insertion? Feasibility and accuracy evaluation.

PURPOSE: Accurate and safe posterior thoracic pedicle insertion (PTPI) remains a challenge. Patient-specific drill templates (PDTs) created by rapid prototyping (RP) can assist in posterior thoracic pedicle insertion, but pose biocompatibility risks. The aims of this study were to develop alternative PDTs with computer numerical control (CNC) and assess their feasibility and accuracy in assisting PTPI. METHODS: Preoperative CT images of 31 cadaveric thoracic vertebras were obtained and then the optimal pedicle screw trajectories were planned. The PDTs with optimal screw trajectories were randomly assigned to be designed and manufactured by CNC or RP in each vertebra. With the guide of the CNC- or RP-manufactured PDTs, the appropriate screws were inserted into the pedicles. Postoperative CT scans were performed to analyze any deviations at entry point and midpoint of the pedicles. RESULTS: The CNC group was found to be significant manufacture-time-shortening, and cost-decreasing, when compared with the RP group (P < 0.01). The PDTs fitted the vertebral laminates well while all screws were being inserted into the pedicles. There were no significant differences in absolute deviations at entry point and midpoint of the pedicle on either axial or sagittal planes (P > 0.05). The screw positions were grade 0 in 90.3% and grade 1 in 9.7% of the cases in the CNC group and grade 0 in 93.5% and grade 1 in 6.5% of the cases in the RP group (P = 0.641). CONCLUSION: CNC-manufactured PDTs are viable for assisting in PTPI with good feasibility and accuracy.

Distribution of iliac veins posterior to the common iliac artery bifurcation related to pelvic lymphadenectomy: A digital in vivo anatomical study of 442 Chinese females.

OBJECTIVES: To investigate the distribution of iliac veins posterior to common iliac artery bifurcation (CIAB) for pelvic lymphadenectomy. METHODS: After IRB approval was obtained, computer tomography angiography data of 442 female pelvises were acquired. After vascular three-dimensional (3D) reconstructions, the structural types, frequencies and diameters of iliac veins immediately posterior to CIAB were investigated and measured. To quantify iliac vein courses, linear distances and their distances on sagittal, coronal and vertical axes from CIAB to external/internal iliac veins confluence (EIIVC) were geometrically measured. RESULTS: There were five structural types of iliac veins distribution immediately posterior to CIAB: common iliac vein (CIV, 13.8%), no occurrence of great vein (N, 71.27%, 0), EIIVC (1.58%) and external iliac vein (EIV, 13.35%) on the left side, while confluence of common iliac veins (CCIV, 8.82%), CIV (77.38%), N (1.58%, 0), EIIVC (6.11%), and EIV (6.11%) on right. The venous diameters immediately posterior to CIAB in "CCIV", "CIV" and "EIIVC" were significantly larger than that in "EIV" (P<0.05). Their linear distances and their distances on each axis from CIAB to external/internal iliac veins confluence (EIIVC) from CIAB to EIIVC were obtained. CONCLUSIONS: In this study, we presented new distribution of iliac veins posterior to CIAB, including structural types, frequencies, venous diameters immediately posterior to CIAB, and their quantified courses from CIAB to EIIVC. It could help surgeons reduce the risk of vascular injury, hemorrhage or transfusion in pelvic lymphadenectomy.

An ex vivo liver training model continuously perfused to simulate bleeding for suture skills involved in laparoscopic liver resection: development and validity.

BACKGROUND: Suture skills are essential to laparoscopic liver resection. The current suture training models are not ideal enough. The aim of this study is to develop and verify a highly simulated-bleeding continuously perfused training model (CPTM) and to evaluate its training efficacy. METHODS: CPTM was constructed using fresh lamb liver whose portal veins were perfused with red-dyed liquid gelatin. Construct validity of CPTMs was tested in 33 participants with three levels of laparoscopic experience (experts, intermediates, and novices) who were demanded to finish one superficial stitch and one deep stitch for suture hemostasis on CPTMs. The CPTMs were also evaluated by the experts. CPTMs were compared with dry box training models (DBTMs) regarding training efficacy among the novices who were assigned to DBTM and CPTM groups to, respectively, complete a 10-day training on CPTMs or DBTMs. Before and after their assignments, their superficial stitches were assessed by completion time, suture accuracy, and suture knot performance while their deep stitches by completion time and bleeding control. RESULTS: CPTM proved to be construct valid by both superficial and deep stitches. Significant differences were found regarding completion time (763, 271, 174 s), suture accuracy (4.4, 1.8, 0.2 mm), and suturing knot performance (12.1, 21.5, 22.0) for superficial stitches (p < 0.001), as well as regarding completion time (807, 423, 277 s) for deep stitches (p < 0.001). Positive comments were given by all experts. CPTMs helped novices to acquire laparoscopic suture skills. Their training efficacy was significantly better than that of DBTMs (p < 0.05). Learning curves of CPTM group plateaued at the sixth round for superficial stitches and at the seventh round for deep stitches. CONCLUSION: CPTM offers trainees a highly simulated-bleeding means to acquire advanced laparoscopic suture skills. The suture skills learned on CPTMs may improve significantly at the seventh round.

Do 3D Printing Models Improve Anatomical Teaching About Hepatic Segments to Medical Students? A Randomized Controlled Study.

BACKGROUND: It is a difficult and frustrating task for young surgeons and medical students to understand the anatomy of hepatic segments. We tried to develop an optimal 3D printing model of hepatic segments as a teaching aid to improve the teaching of hepatic segments. METHODS: A fresh human cadaveric liver without hepatic disease was CT scanned. After 3D reconstruction, three types of 3D computer models of hepatic structures were designed and 3D printed as models of hepatic segments without parenchyma (type 1) and with transparent parenchyma (type 2), and hepatic ducts with segmental partitions (type 3). These models were evaluated by six experts using a five-point Likert scale. Ninety two medical freshmen were randomized into four groups to learn hepatic segments with the aid of the three types of models and traditional anatomic atlas (TAA). Their results of two quizzes were compared to evaluate the teaching effects of the four methods. RESULTS: Three types of models were successful produced which displayed the structures of hepatic segments. By experts' evaluation, type 3 model was better than type 1 and 2 models in anatomical condition, type 2 and 3 models were better than type 1 model in tactility, and type 3 model was better than type 1 model in overall satisfaction (P < 0.05). The first quiz revealed that type 1 model was better than type 2 model and TAA, while type 3 model was better than type 2 and TAA in teaching effects (P < 0.05). The second quiz found that type 1 model was better than TAA, while type 3 model was better than type 2 model and TAA regarding teaching effects (P < 0.05). Only TAA group had significant declines between two quizzes (P < 0.05). CONCLUSIONS: The model with segmental partitions proves to be optimal, because it can best improve anatomical teaching about hepatic segments.

Tunable fluorescent pH sensor based on water-soluble perylene tetracarboxylic acid/Fe(3+).

A novel fluorescent pH sensor with tunable response range was designed based on highly fluorescent 3,4:9,10-perylene tetracarboxylic ammonium, which could coordinate the paramagnetic Fe(3+) ions to turn off its fluorescence and could also release Fe(3+) to turn on the fluorescence again at higher pH. The fluorescent pH sensor was tunable in the presence of different ligands in aqueous solution.

Three-Dimensional Computed Tomographic Study on the Vessels of the Zygomatic Region: Arterial Variations and Clinical Relevance.

BACKGROUND: Injection-based techniques for "cheek augmentation" have gained popularity in recent years. The aim of this study was to perform a topographic analysis of the depth and distribution of the vessels in the zygomatic region to facilitate clinical procedures. METHODS: The external carotid arteries of seven cadaveric heads were infused with lead oxide contrast medium. The facial and superficial temporal arteries of another 12 cadaveric heads were injected sequentially with the same medium. Computed tomographic scanning was then performed, and three-dimensional computed tomographic scans were reconstructed using validated algorithms. RESULTS: The vessels on the zygomatic arch received a double blood supply from across the upper and lower borders of the arch, and the number of the vessels varied from one to four. Ninety percent of the vessels on the zygomatic arch were at a depth of 1 to 2.5 mm, and 75 percent were at a depth of 10 to 30 percent of the soft-tissue thickness. The vessels were concentrated on the midline of the zygomatic arch and the lateral margin of the frontal process. All samples showed a vessel travel along the lateral margin of the frontal process that eventually merged into the superior marginal arcades. CONCLUSIONS: This study reported a topographic analysis of the depth and distribution of the vessels in the zygomatic region based on three-dimensional scanning. The results indicated that injection on the zygomatic arch should be performed deep to the bone, and the vascular zones anterior or posterior to the midline of the zygomatic arch were relatively safe injection areas.

Clinicopathological Significance of Heat Shock Protein (HSP) 27 Expression in Gastric Cancer: A Updated Meta-Analysis.

AIM: HSP27 is a protein chaperone protecting cell from heat shock, and upregulated HSP27 expression has been found in many different cancers. We conduct this update meta-analysis to evaluate the relationship between HSP27 expression and clinicopathological features. METHODS: We searched PubMed, Chinese CNKI, and WanFang databases to identify studies that assessed the association between clinicopathological feature and HSP27 expression in gastric cancer patients. RESULTS: We found overexpression of HSP27 was associated with incidence of gastric cancer (OR = 6.31, 95% CI = 1.10-36.15, P < 0.0001). However, there was no significant difference between HSP27 expression and gastric cancer differentiation, gender difference, lymph node metastasis, and distant metastasis. CONCLUSION: Our meta-analysis study indicates that overexpression of HSP27 is associated with incidence of gastric cancer statistically.

Paclitaxel increases sensitivity of SKOV3 cells to hyperthermia by inhibiting heat shock protein 27.

Hyperthermic intraperitoneal chemotherapy (HIPEC) is a promising treatment strategy for patients with peritoneal metastasis of ovarian cancer. Heat shock proteins (HSPs) play an important role in cellular stress during HIPEC treatment. The aim of the present study was to investigate whether paclitaxel can exert antitumor effects by inhibiting heat shock protein 27 (HSP27) expression during HIPEC treatment. Cell viability was detected by CCK8 assay. We used Western blot analysis to detect HSP27 expression under hyperthermia conditions with or without paclitaxel in SKOV3 cells. To further examine the role of HSP27 in the apoptosis, Bcl-2, Bax and Caspase-3 protein expression were additionally determined after reducing HSP27 levels using an siRNA strategy, and apoptosis was detected using the Annexin V/PI assay. The upregulation of HSP27 expression was accompanied with a rise in temperature. In addition, HSP27 could promote Bcl-2 expression, inhibit Bax and Caspase-3 expression, reduce the Bax / Bcl-2 ratio markedly in SKOV3 cells. Furthermore, paclitaxel could upregulate the Bax / Bcl-2 ratio by inhibiting HSP27 expression, and in turn, promoting apoptosis due to hyperthermia. Paclitaxel could also promote apoptosis by inhibiting HSP27 in SKOV3 cells. Our results demonstrate a synergistic effect between paclitaxel and hyperthermia at the cellular level.

Revealing the redox status in endoplasmic reticulum by a selenium fluorescence probe.

As an important organelle, the endoplasmic reticulum (ER) participates in the synthesis and secretion of various proteins, glycogen, lipids and cholesterol in eukaryotic cells. In this work, an endoplasmic reticulum-targeted reversible fluorescent probe (ER-Se) was designed and synthesized. The probe, based on a selenide group, shows high sensitivity and good selectivity toward HClO (LOD = 0.85 µM). In addition, the probe has reversible capability towards HClO/GSH. Most importantly, co-location experiment results indicated that the probe exhibited a great ability to target the endoplasmic reticulum. Furthermore, the probe was successfully applied to detect exogenous and endogenous HClO in ER and monitored the redox status changes during ER stress.

Revelation of microalgae's lipid production and resistance mechanism to ultra-high Cd stress by integrated transcriptome and physiochemical analyses.

The ultra-high Cd polluted environment is a special habitat in nature. Analysis of the biological adaptation and resistance mechanism of Auxenochlorella protothecoides UTEX234 to ultra-high Cd stress would offer some inspiring understanding on Cd detoxification mechanism and help discovering highly active bioremediation agents. In this study, integrated analyses of the transcriptome, multi-physiological and biochemical data and fatty acid profilings of UTEX2341 were performed for the first time. It was found that exogenous Ca ions could alleviate Cd stress. Manganese-dependent superoxide dismutase and peroxidase also participated in intracellular detoxification. And non-enzymatic antioxidants rather than one specific enzymatic antioxidant were suggested to be used as "core antioxidants", which witnessed better performance in Cd detoxification. In addition, Cd stress improved sixteen alkane value and biofuel yield and quality.

High-Throughput Screening of Full-Face Clinically Relevant Arterial Variations Using Three-Dimensional Postmortem Computed Tomography.

BACKGROUND: Vascular complications resulting from intravascular filler injection and embolism are major safety concerns for facial filler injection. It is essential to systematically screen full-face arterial variations and help design evidence-based safe filler injection protocols. METHODS: The carotid arteries of 22 cadaveric heads were infused with adequate lead oxide contrast. The facial and superficial temporal arteries of another 12 cadaveric heads were injected with the contrast in a sequential order. A computed tomographic scan was acquired after each contrast injection, and each three-dimensional computed tomographic scan was reconstructed using validated algorithms. RESULTS: Three-dimensional computed tomography clearly demonstrated the course, relative depth, and anastomosis of all major arteries in 63 qualified hemifaces. The ophthalmic angiosome consistently deploys two distinctive layers of branch arteries to the forehead. The superficial temporal and superior palpebral arteries run along the preauricular and superior palpebral creases, respectively. The study found that 74.6 percent of the hemifaces had nasolabial trunks coursing along the nasolabial crease, and that 50.8 percent of the hemifaces had infraorbital trunks that ran through the infraorbital region. Fifty percent of the angular arteries were the direct anastomotic channels between the facial and ophthalmic angiosomes, and 29.2 percent of the angular arteries were members of the ophthalmic angiosomes. CONCLUSIONS: Full-face arterial variations were mapped using postmortem three-dimensional computed tomography. Facial creases were in general correlated with underlying deep arteries. Facial and angular artery variations were identified at high resolution, and reclassified into clinically relevant types to guide medical practice.

Do Three-dimensional Visualization and Three-dimensional Printing Improve Hepatic Segment Anatomy Teaching? A Randomized Controlled Study.

INTRODUCTION: Hepatic segment anatomy is difficult for medical students to learn. Three-dimensional visualization (3DV) is a useful tool in anatomy teaching, but current models do not capture haptic qualities. However, three-dimensional printing (3DP) can produce highly accurate complex physical models. Therefore, in this study we aimed to develop a novel 3DP hepatic segment model and compare the teaching effectiveness of a 3DV model, a 3DP model, and a traditional anatomical atlas. MATERIALS AND METHODS: A healthy candidate (female, 50-years old) was recruited and scanned with computed tomography. After three-dimensional (3D) reconstruction, the computed 3D images of the hepatic structures were obtained. The parenchyma model was divided into 8 hepatic segments to produce the 3DV hepatic segment model. The computed 3DP model was designed by removing the surrounding parenchyma and leaving the segmental partitions. Then, 6 experts evaluated the 3DV and 3DP models using a 5-point Likert scale. A randomized controlled trial was conducted to evaluate the educational effectiveness of these models compared with that of the traditional anatomical atlas. RESULTS: The 3DP model successfully displayed the hepatic segment structures with partitions. All experts agreed or strongly agreed that the 3D models provided good realism for anatomical instruction, with no significant differences between the 3DV and 3DP models in each index (p > 0.05). Additionally, the teaching effects show that the 3DV and 3DP models were significantly better than traditional anatomical atlas in the first and second examinations (p < 0.05). Between the first and second examinations, only the traditional method group had significant declines (p < 0.05). CONCLUSION: A novel 3DP hepatic segment model was successfully developed. Both the 3DV and 3DP models could improve anatomy teaching significantly.

[Construction of a three-dimensional digital model of the liver of Wuzhishan mini-pig].

OBJECTIVE: To construct a three-dimensional (3D) liver model of Wuzhishan mini-pig for virtual liver surgeries. METHODS: The biliary tree and hepatic arteries of Wuzhishan mini-pig were perfused with perchloroethylene and ethyl acetate along mixed with lead oxide, and the hepatic vein and portal vein were perfused with a mixture of dental base acrylic resin and lead oxide. The sectional images were acquired using a 64-slice spiral CT, and the 3D models of the portal vein, hepatic vein, biliary tree, hepatic arteries, and liver parenchyma were reconstructed using Mimics software; the resection image of the liver was also designed. The intrahepatic vascular cast was prepared by corroding the soft tissue with hydrochloric acid. RESULTS AND CONCLUSION: The intrahepatic vascular cast obtained fully retained the vascular architecture and displayed the fifth- and sixth-level branches of the hepatic vein and portal vein and the third- and fourth-level branches of the artery and bile duct. The 3D model of liver allowed stereoscopic and accurate display of the third- and fourth-level branches of the hepatic vein and portal vein and the second- and third-level branches of the artery and bile duct. The 3D model showed fewer branches but represented the structural distribution identical to the cast. The 3D model could clearly display the spatial relationship between the vasculature and the soft tissue in virtual resection of the liver tissues, and thus provides a useful model for training of laparoscopic liver resection.