Traditional surgical planning of liver surgery is modified by 3D interactive quantitative surgical planning approach： a single-center experience with 305 patients

BACKGROUND： Decision making and surgical planning are to achieve the precise balance of maximal removal of target lesion, maximal sparing of functional liver remnant volume, and minimal surgical invasiveness and therefore, crucial in liver surgery. The aim of this prospective study was to validate the accuracy and predictability of 3D interactive quantitative surgical planning approach （IQSP）, and to evaluate the impact of IQSP on traditional surgical plans based on 2D images. METHODS： A total of 305 consecutive patients undergoing hepatectomy were included in this study. Surgical plans were created by traditional 2D approach using picture archiving and communication system （PACS） and 3D approach using IQSP respectively by two groups of physicians who did not know the surgical plans of the other group. The two surgical plans were submitted to the chief surgeon for selection before operation. The specimens were weighed. The two surgical plans were compared and analyzed retrospectively based on the operation results. RESULTS： The two surgical plans were successfully developed in all 305 patients and all the 3D IQSP surgical plans were selected as the final decision. Total 278 patients successfully underwent surgery, including 147 uncomplex hepatectomy and 131 complex hepatectomy. Twenty-seven patients were withdrawn from hepatectomy. In the uncomplex group, the two surgical plans were the same in all 147 patients and no statistically significant difference was found among 2D calcu- lated resection volume （2D-RV）, 3D IQSP calculated resection volume （IQSP-RV） and the specimen volume. In the complex group, the two surgical plans were different in 49 patients （49/131, 37.4%）. According to the significance of differences, the 49 different patients were classified into three grades. No statistically significant difference was found between IQSP-RV and specimen volume. The coincidence rate of territory analy- sis of IQSP with operation was 92.1% （93/101） for 101 patients of anatomic hepatectomy. CONCLUSIONS： The accuracy and predictability of 3D IQSP were validated. Compared with traditional surgical planning, 3D IQSP can provide more quantitative information of anatomic structure. With the assistance of 3D IQSP, traditional surgical plans were modified to be more radical and safe.

Topological approach of liver segmentation based on 3D visualization technology in surgical planning for split liver transplantation

BACKGROUND Split liver transplantation(SLT)is a complex procedure.The left-lateral and right tri-segment splits are the most common surgical approaches and are based on the Couinaud liver segmentation theory.Notably,the liver surface following right trisegment splits may exhibit different degrees of ischemic changes related to the destruction of the local portal vein blood flow topology.There is currently no consensus on preoperative evaluation and predictive strategy for hepatic segmental necrosis after SLT.AIM To investigate the application of the topological approach in liver segmentation based on 3D visualization technology in the surgical planning of SLT.METHODS Clinical data of 10 recipients and 5 donors who underwent SLT at Shenzhen Third People’s Hospital from January 2020 to January 2021 were retrospectively analyzed.Before surgery,all the donors were subjected to 3D modeling and evaluation.Based on the 3D-reconstructed models,the liver splitting procedure was simulated using the liver segmentation system described by Couinaud and a blood flow topology liver segmentation(BFTLS)method.In addition,the volume of the liver was also quantified.Statistical indexes mainly included the hepatic vasculature and expected volume of split grafts evaluated by 3D models,the actual liver volume,and the ischemia state of the hepatic segments during the actual surgery.RESULTS Among the 5 cases of split liver surgery,the liver was split into a left-lateral segment and right trisegment in 4 cases,while 1 case was split using the left and right half liver splitting.All operations were successfully implemented according to the preoperative plan.According to Couinaud liver segmentation system and BFTLS methods,the volume of the left lateral segment was 359.00±101.57 mL and 367.75±99.73 mL,respectively,while that measured during the actual surgery was 397.50±37.97 mL.The volume of segment IV(the portion of ischemic liver lobes)allocated to the right tri-segment was 136.31±86.10 mL,as determined using the topological approach to liver segmentation.However,during the actual surgical intervention,ischemia of the right tri-segment section was observed in 4 cases,including 1 case of necrosis and bile leakage,with an ischemic liver volume of 238.7 mL.CONCLUSION 3D visualization technology can guide the preoperative planning of SLT and improve accuracy during the intervention.The simulated operation based on 3D visualization of blood flow topology may be useful to predict the degree of ischemia in the liver segment and provide a reference for determining whether the ischemic liver tissue should be removed during the surgery.

3D-printed models improve surgical planning for correction of severe postburn ankle contracture with an external fixator

Gradual distraction with an external fixator is a widely used treatment for severe postburn ankle contracture(SPAC).However,application of external fixators is complex,and conventional two-dimensional(2D)imaging-based surgical planning is not particularly helpful due to a lack of spatial geometry.The purpose of this study was to evaluate the surgical planning process for this procedure with patient-specific three-dimension-printed models(3DPMs).In this study,patients coming from two centers were divided into two cohorts(3DPM group vs.control group)depending on whether a 3DPM was used for preoperative surgical planning.Operation duration,improvement in metatarsal-tibial angle(MTA),range of motion(ROM),the American Orthopedic Foot and Ankle Society(AOFAS)scores,complications,and patient-reported satisfaction were compared between two groups.The 3DPM group had significantly shorter operation duration than the control group((2.0±0.3)h vs.(3.2±0.3)h,P<0.01).MTA,ROM,and AOFAS scores between the two groups showed no significant differences pre-operation,after the removal of the external fixator,or at follow-up.Plantigrade feet were achieved and gait was substantially improved in all patients at the final follow-up.Pin-tract infections occurred in two patients(one in each group)during distraction and were treated with wound care and oral antibiotics.Patients in the 3DPM group reported higher satisfaction than those in the control group,owing to better patient-surgeon communication.Surgical planning using patient-specific 3DPMs significantly reduced operation duration and increased patient satisfaction,while providing similar improvements in ankle movement and function compared to traditional surgical planning for the correction of SPAC with external fixators.

Preoperative surgical planning for intracranial meningioma resection by virtual reality

Background The Dextroscope system by Volume Interactions （Singapore） had been applied to minimally invasive neurosurgery in many units. This system enables the neurosurgeon to interact intuitively with the three-dimensional graphics in a direct manner resembling the way one communicates with the real objects. In the paper, we explored its values in pre-operation surgical planning for intracranial meningiomas resection. Methods Brain computed tomography （CT）, magnetic resonance imaging （MRI）, and magnetic resonance venography （MRV） were performed on 10 patients with parasagittal and falcine meningiomas located on central groove area; brain CT, MRI and magnetic resonance angiography （MIRA） were performed on 10 patients with anterior skull base meningiomas and 10 patients with sphenoid ridge meningiomas. All these data were transferred to Dextroscope virtual reality system, and reconstructed. Then meningiomas, skull base, brain tissue, drainage vein and cerebral arteries were displayed within the system, and their anatomic relationships were evaluated. Also, the simulation operations were performed. Results For parasagittal and falcine meningiomas, the relationships of tumor with drainage vein and superior sagittal sinus were clearly displayed in the Dextroscope system. For anterior skull base and sphenoid ridge meningiomas, the relationships of tumor with bilateral internal carotid arteries, anterior cerebral arteries, middle cerebral arteries and skull base were vividly displayed within the virtual reality system. Surgical planning and simulation operation of all cases were performed as well. The real operations of all patients were conducted according to the simulation with well outcomes. Conclusions According to the virtual reality planning, neurosurgeons could get more anatomic information about meningioma and its surrounding structures, especially important vessels, and choose the best approach for tumor resection, which would lead to better prognosis for patients.

Virtual surgical planning is a useful tool in the surgical management of mandibular condylar fractures

Purpose:The aim of this study is to evaluate the application value of virtual surgical planning in the management of mandibular condylar fractures and to provide a reliable reference.Methods:This was a prospective randomized controlled study and recruited 50 patients requiring surgical treatment for their mandibular condylar fractures.The inclusion criteria were patients(1)diagnosed with a condylar fracture by two clinically experienced doctors and required surgical treatment;(2)have given consent for the surgical treatment;and(3)had no contraindications to the surgery.Patients were excluded from this study if:(1)they were diagnosed with a non-dislocated or only slightly dislocated condylar fracture;(2)the comminuted condylar fracture was too severe to be treated with internal reduction and fixation;or(3)patients could not complete follow-up for 3 months.There were 33 male and 17 female patients with 33 unilateral condylar fractures and 17 bilateral condylar fractures included.The 50 patients were randomly(random number)divided into control group(25 patients with 35 sides of condylar fractures)and experimental group(25 patients with 32 sides of condylar fractures).Virtual surgical planning was used in the experimental group,but only clinical experience was used in the control group.The patients were followed up for 1,3,6 and 12 months after operation.Variables including the rate of perfect reduction by radiological analysis,the average distance of deviation between preoperative and postoperative CT measurements using Geomagic software and postoperative clinical examinations(e.g.,mouth opening,occlusion)were investigated for outcome measurement.SPSS 19 was adopted for data analysis.Results:The average operation time was 180.60 min in the experimental group and 223.2 min in the control group.One week postoperatively,CT images showed that the anatomic reduction rate was 90.63%(29/32)in the experimental group and 68.57%(24/35)in the control group,revealing significant difference(X^(2)=4.919,p=0.027).Geomagic comparative analysis revealed that the average distance of deviation was also much smaller in the experimental group than that in the control group(0.639 mm vs.0.995 mm;t=3.824,p<0.001).Conclusion:These findings suggest that virtual surgical planning can assist surgeons in surgical procedures,reduce operative time,and improve the anatomic reduction rate&accuracy,and thus of value in the diagnosis and treatment of condylar fractures.

Lumped parameter model based surgical planning for CABG

The current 3D CABG model is time consuming,a lumped parameter CABG model may solve this problem.A coronary lumped parameter model without stenosis and graft was constructed.The stenosis resistance was calculated and graft model was constructed.After calculation,the graft flow results of CABG lumped parameter model fit well with 3D CABG model results.

Face transplantation for massive mandibular defects: considerations for allograft design and surgical planning

Modern face transplant techniques have advanced to allow for the transfer of vascularized skeletal components in addition to overlying soft tissue.This represents significant opportunity for individuals with mandibular defects that are not amenable to traditional reconstruction.Care must be taken when planning and executing transplants with these complex grafts,as satisfactory functional and aesthetic outcomes rely on achieving proper spatial relationships between the mandible,skull base,and midface.Which donor skeletal elements are included in the allograft and how they are harvested are important considerations in this planning and are associated with controversy.To optimize outcomes in the reconstruction of single-jaw defects,some advocate for transplantation of only the affected jaw while others support bimaxillary transplantation.Clinical evidence in this debate is not conclusive at this time.In current practice,including donor dentoalveolar anatomy by utilizing a bilateral sagittal split osteotomy of the mandible is favored to optimize outcomes such as dental occlusion.It has been suggested that harvesting the mandible at the level of the condyle or even the temporal bone may also be possible and may improve temporomandibular joint-related outcomes.Despite encouraging preclinical evidence,these strategies remain controversial.After allograft design,successful mandibular reconstruction with face transplantation relies on surgical precision in the donor and recipient procedures.Computerized surgical planning,computer-aided design and manufacturing,and intraoperative navigation are technologies currently in use to mitigate operative complexity.Results in both cadaveric and clinical face transplantations suggest these technologies are reliable and beneficial,although some room for improvement remains.

Prospects of 3D Printing Technology in Dental Medicine

With the continuous advancement of technology,the application of 3D printing technology in the field of dental medicine is becoming increasingly widespread.This article aims to explore the current applications and future potential of 3D printing technology in dental medicine and to analyze its benefits and challenges.It first introduces the current state of 3D printing technology in dental implants,crowns,bridges,orthodontics,and maxillofacial surgery.It then discusses the potential applications of 3D printing technology in oral tissue engineering,drug delivery systems,personalized dental prosthetics,and surgical planning.Finally,it analyzes the benefits of 3D printing technology in dental medicine,such as improving treatment accuracy and patient comfort,and shortening treatment times,while also highlighting the challenges faced,such as costs,material choices,and technical limitations.This article aims to provide a reference for professionals in the field of dental medicine and to promote the further application and development of 3D printing technology in this area.

Application value of mixed reality in hepatectomy for hepatocellular carcinoma

BACKGROUND As a new digital holographic imaging technology,mixed reality(MR)technology has unique advantages in determining the liver anatomy and location of tumor lesions.With the popularization of 5 G communication technology,MR shows great potential in preoperative planning and intraoperative navigation,making hepatectomy more accurate and safer.AIM To evaluate the application value of MR technology in hepatectomy for hepatocellular carcinoma(HCC).METHODS The clinical data of 95 patients who underwent open hepatectomy surgery for HCC between June 2018 and October 2020 at our hospital were analyzed retrospectively.We selected 95 patients with HCC according to the inclusion criteria and exclusion criteria.In 38 patients,hepatectomy was assisted by MR(Group A),and an additional 57 patients underwent traditional hepatectomy without MR(Group B).The perioperative outcomes of the two groups were collected and compared to evaluate the application value of MR in hepatectomy for patients with HCC.RESULTS We summarized the technical process of MR-assisted hepatectomy in the treatment of HCC.Compared to traditional hepatectomy in Group B,MR-assisted hepatectomy in Group A yielded a shorter operation time(202.86±46.02 min vs 229.52±57.13 min,P=0.003),less volume of bleeding(329.29±97.31 mL vs 398.23±159.61 mL,P=0.028),and shorter obstructive time of the portal vein(17.71±4.16 min vs 21.58±5.24 min,P=0.019).Group A had lower alanine aminotransferas and higher albumin values on the third day after the operation(119.74±29.08 U/L vs 135.53±36.68 U/L,P=0.029 and 33.60±3.21 g/L vs 31.80±3.51 g/L,P=0.014,respectively).The total postoperative complications and hospitalization days in Group A were significantly less than those in Group B[14(37.84%)vs 35(60.34%),P=0.032 and 12.05±4.04 d vs 13.78±4.13 d,P=0.049,respectively].CONCLUSION MR has some application value in three-dimensional visualization of the liver,surgical planning,and intraoperative navigation during hepatectomy,and it significantly improves the perioperative outcomes of hepatectomy for HCC.

Virtual reality system for diagnosis and therapeutic planning of cerebral aneurysms

Background The virtual reality （VR） system can provide the neurosurgeon to intuitively interact with and manipulate the three dimensional （3-D） image similarly to manipulate a real object.it was seldom reported that the system was used in diagnosis and treatment of cerebral aneurysms.This study aimed to investigate the application of VR system in diagnosis and therapeutic planning of cerebral aneurysms.Methods A total of 24 cases of cerebral aneurysms were enrolled in this study from 2006 to 2008, which diagnosed by 3-D digital subtraction angiography （3D-DSA） or VR-based computed tomography angiographies （CTA）.The VR system and 3D-DSA system were used to observe and measure aneurysms and the adjacent vessels.The data of observation and measurements were compared between VR image and 3D-DSA image.All the patients underwent surgical plan and simulated neurosurgical procedures in the VR system.Results There were 28 aneurysms detected in VR system and 3D-DSA system.The VR system generated clear and vivid 3-D virtual images which clearly displayed the location and size of the aneurysms and their precise anatomical spatial relations to the parent arteries and skull.The location, size and shape of the aneurysms and their anatomical relationship with the adjacent vessels were similar between 3-D virtual image and 3D-DSA, but the spatial relationship between aneurysms and skull only been displayed by VR system.This VR system also could simulate simple surgical procedures and surgical environments.Conclusions The VR system can provide a highly effective way to provide precise imaging details as same as 3D-DSA system and assist the diagnosis of cerebral aneurysms with virtual 3-D data based on CTA.It significantly enhances the chosen therapeutic strategy of cerebral aneurysms.

Simulation training in endoscopic skull base surgery: A scoping review

Objective:Proficiency in endoscopic endonasal skull base surgery requires both substantial baseline training and progressive lifelong learning.Endoscopic simulation models continue to evolve in an effort to optimize trainee education and preoperative preparation and improve surgical outcomes.The current scoping review systematically reviews all available literature and synthesizes the current paradigms of simulation models for endoscopic skull base surgery training and skill enhancement.Methods:In accordance with Preferred Reporting Items for Systemic Review and Meta-Analyses guidelines,we systematically searched PubMed,Embase,CINAHL,and Cochrane databases.Studies were categorized according to the type of simulation models investigated.Results:We identified 238 unique references,with 55 studies ultimately meeting inclusion criteria.Of these,19 studies described cadaveric dissection models,17 discussed three-dimensional(3D)printed models,14 examined virtual surgical planning and augmented reality-based models,and five 5 articles described task trainers.Conclusions:There are a wide variety of simulation models for endoscopic skull base surgery,including high-fidelity cadaveric,virtual reality,and 3D-printed models.These models are an asset for trainee development and preoperative surgical preparation.

Cranio-maxillofacial surgery simulation based on pre-specified target face configurations

This paper presents a novel method for assisting surgeons in automatically computing an optimal surgical plan by directly specifying the desired correction to a facial outline. First, the desired facial appearance is designed using a 3D sculpturing tool, while the cut regions of the skull are defined based on facial anatomy. Then, the deformation of the face meshes is performed using an improved biomechanical model in which virtual external forces are driven by the displacements corresponding to the differences of node coordinates between the original and specified face meshes, and free nodes and fixed nodes are defined in terms of the contact surfaces between the soft tissues and the bones within the cut regions. Finally, the shape of the contact surfaces is updated following the deformation of the soft tissues. After registering the deformable contact surfaces and the cut surfaces, the final positions of the cut bones are estimated. Evaluation of preliminary experimental results quantitatively shows the effectiveness of the proposed approach.

The evolution of anatomical hepatectomy:Past,present,and future

The liver contains a complex structure of blood vessels and bile ducts,and the vascular structure is highly variable.The anatomical segmentation of the liver is still controversial,and the Couinaud segmentation method based on the portal vein is more widely used in clinical practice.The treatment of liver tumors and other lesions is closely related to the liver anatomy.The mechanism of liver tumor invasion and metastasis is complex,and it is currently believed that tumor invasion mainly spreads along the portal vein.Anatomic liver resection is an important surgical method for liver diseases,especially liver tumors.This article reviews the vascular structure of the liver,the development of anatomical hepatectomy,blood flow control,surgical planning,intraoperative navigation,minimally invasive surgery,and precise hepatectomy.Anatomic liver resection is a part of precision liver surgery,which is becoming increasingly more precise in terms of surgical evaluation,surgical planning,and surgical operation.New technologies will facilitate precision surgery with less trauma and greater benefits for patients.With the development and advancement of technology,image-based surgical planning and intraoperative surgical navigation will become more widely used in precision liver surgery.