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.

Combining robot-assisted surgical system and 3D visualization system for teaching minimally invasive vitreoretinal surgery

AIM:To investigate the feasibility of teaching minimally invasive vitreoretinal surgery with a robot-assisted surgical system and a three-dimensional(3D) visualization system.METHODS:Enucleated porcine eyes were established as an animal model for removing foreign bodies.Forty medical students were recruited to remove foreign bodies to compare the traditional microscope and the 3D system.One junior resident performed the surgical task with manual and robot-assisted operations on 20 porcine eyes for each group.One senior surgeon evaluated the retinal invasion by a graded injury degree.The learning curve for minimally invasive vitreoretinal surgery was described.RESULTS:Compared with the robot-assisted group,the injury degree was higher in the manual group.For the first ten surgeries,the manual and robot-assisted groups had injuries of 2.60±1.35(4 to 0) and 1.80±1.62(4 to 0),respectively.For the last ten surgeries,the injury degrees were 1.90±1.20(3 to 0) and 0.80±0.42(1 to 0).Considering the manual and robot-assisted groups together,95%,75% and 60% of the students considered surgical manipulation with the 3D visualization system to be more comfortable,easier and clearer,respectively.CONCLUSION:The robot-assisted surgical system and 3D visualization system may have value in teaching minimally invasive vitreoretinal surgery.

Intraoperative application of three-dimensional printed guides in total hip arthroplasty: A systematic review

BACKGROUND Acetabular component positioning in total hip arthroplasty(THA)is of key importance to ensure satisfactory post-operative outcomes and to minimize the risk of complications.The majority of acetabular components are aligned freehand,without the use of navigation methods.Patient specific instruments(PSI)and three-dimensional(3D)printing of THA placement guides are increasingly used in primary THA to ensure optimal positioning.AIM To summarize the literature on 3D printing in THA and how they improve acetabular component alignment.METHODS PubMed was used to identify and access scientific studies reporting on different 3D printing methods used in THA.Eight studies with 236 hips in 228 patients were included.The studies could be divided into two main categories;3D printed models and 3D printed guides.RESULTS 3D printing in THA helped improve preoperative cup size planning and post-operative Harris hip scores between intervention and control groups(P=0.019,P=0.009).Otherwise,outcome measures were heterogeneous and thus difficult to compare.The overarching consensus between the studies is that the use of 3D guidance tools can assist in improving THA cup positioning and reduce the need for revision THA and the associated costs.CONCLUSION The implementation of 3D printing and PSI for primary THA can significantly improve the positioning accuracy of the acetabular cup component and reduce the number of complications caused by malpositioning.

三维可视化联合3D打印在Bismuth-CorletteⅢ、Ⅳ型肝门部胆管癌个体化精准外科治疗中的应用

目的探讨三维可视化3D打印在Bismuth-CorletteⅢ、Ⅳ型肝门部胆管癌个体化精准外科治疗中的应用价值。方法回顾性分析南方医科大学珠江医院肝胆外科2016年5月~2019年3月在三维可视化3D打印指导下10例肝门部胆管癌外科手术治疗患者。收集患者薄层CT数据,进行三维重建后打印3D模型,观察肿瘤与肝内胆管、肝动脉、门静脉和肝静脉系统的三维立体关系,进行术前模拟手术并制定手术方案,将3D打印模型带入手术室进行术中实时导航,指导手术治疗。结果10例患者均成功构建三维可视化打印3D模型,进行Bismuth-Corlette三维可视化分型:Ⅲa型4例、Ⅲb型4例、Ⅳ型2例,其中门静脉变异4例,肝动脉变异3例。门静脉“三分叉”变异2例;“工字型”变异1例;1例罕见的门静脉右前支缺如变异;2例既有门静脉变异又出现肝动脉变异。肝动脉变异3例,1例肝左动脉起自胃左动脉,2例肝右动脉起自肠系膜上动脉。其中Ⅲb型4例行左半肝切除术;Ⅲa型4例行右半肝切除;Ⅳ型1例行围肝门区域切除,1例行左半肝切除术。此组患者术前三维可视化3D打印模型及术前规划与术中情况均一致。手术时间452±75.12 min,术中出血量356±62.35 mL,术后住院时间15±4.61 d。术后出现胆漏1例,少量胸腔积液3例,经通畅引流及内科治疗后康复出院,围手术期无肝功能衰竭及死亡病例。结论三维可视化联合3D打印对Bismuth-CorletteⅢ、Ⅳ肝门部胆管癌进行准确的术前评估、手术规划,优化手术方案,尤其在肝内血管变异情况下,有助于提高手术安全性,降低手术风险。

影像实物建模的医学应用价值与局限

评估基于快速成型技术的影像实物建模在医学中的应用价值,并讨论其进一步应用增长的限制因素与未来前景。

数字化手术方案的虚拟可视化呈现

数字化手术方案是对手术过程涉及要素的形式化、结构化描述。手术方案的虚拟可视化呈现有助于医生洞悉手术环境,掌握手术过程的细节,便于医患交流。目前在手术方案的可视化方面,往往注重解剖结构的3D可视化,而忽略辅助信息和表现动态操作过程的可视化呈现。针对这个问题,面向微创手术规划的需求,提出手术方案的形式化定义和存储结构,并提出数字化手术方案结构文档的解析算法,解决个性化手术方案的虚拟可视化呈现问题。

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.

Volumetric comparative analysis of anatomy through far-lateral approach:surgical space and exposed tissues

Background:The three-dimensional(3D)visualization model has ability to quantify the surgical anatomy of farlateral approach.This study was designed to disclose the relationship between surgical space and exposed tissues in the far-lateral approach by the volumetric analysis of 3D model.Methods:The 3D skull base models were constructed using MRI and CT data of 15 patients(30 sides)with trigeminal neuralgia.Surgical corridors of the far-lateral approach were simulated by triangular pyramids to represent two surgical spaces exposing bony and neurovascular tissues.Volumetric comparison of surgical anatomy was performed using pair t test.Results:The morphometric results were almost the same in the two surgical spaces except the vagus nerve(CN X)exposed only in one corridor,whereas the volumetric comparison represented the statistical significant differences of surgical space and bony and neurovascular tissues involved in the two corridors(P<0.001).The differences of bony and neurovascular tissues failed to equal the difference of surgical space.Conclusions:For far-lateral approach,the increase of exposure for the bony and neurovascular tissues is not necessarily matched with the increase of surgical space.The volumetric comparative analysis is helpful to provide more detailed anatomical information in the surgical design.

三维可视化手术规划系统在微波消融治疗肝脏血管瘤患者的效果观察

目的探讨三维可视化手术规划系统在微波消融治疗肝脏血管瘤患者的效果。方法选取2018年10月至2020年4月本院收治的采用微波消融治疗的肝脏血管瘤患者66例作为研究对象,以双盲法分为对照组和实验组,各33例。对照组采用二维可视化手术规划系统治疗,实验组采用三维可视化手术规划系统治疗,比较两组治消融指标、肝功能指标及并发症发生情况。结果实验组消融能量低于对照组,消融时间短于对照组,完全消融率高于对照组,差异均有统计学意义(P<0.05),但组间消融点数比较差异无统计学意义。消融前,两组ALT及AST指标比较差异无统计学意义;消融3 d后,实验组ALT及AST指标均明显低于对照组,差异有统计学意义(P<0.05)。实验组并发症发生率低于对照组,但差异无统计学意义。结论肝脏血管瘤患者采用微波消融治疗时,应用三维可视化手术规划系统可进一步提高完全消融率,缩短消融时间,降低消融能量,且并发症发生率较低,可显著降低肝功能损伤,治疗效果显著。

复杂性肝脏肿瘤三维可视化精准诊治专家共识

肝脏肿瘤三维可视化是指用于显示、描述和解释肝脏肿瘤三维解剖和形态特征的一种工具。它借助CT和（或）MRI图像数据，利用计算机图像处理技术对数据进行分析、融合、计算、分割、渲染等，将肝脏、胆道、血管、肿瘤等目标的形态、空间分布等进行描述和解释，并可直观、准确、快捷地将目标从视觉上分离出来，为术前准确诊断、手术方案个体化规划和手术入路选择提供决策。

腹膜后肿瘤三维可视化精准诊治专家共识(2018版)

腹膜后肿瘤(retroperitoneal tumors)三维可视化是指用于显示、描述和解释腹膜后肿瘤三维解剖和形态特征的一种工具。其借助ET或MRI等图像数据,利用计算机图像处理技术对数据进行分析、融合、计算、分割、渲染等,将肿瘤、腹腔器官、血管等目标的形态、空间分布等进行描述和解释,并可直观、准确、快捷地将目标从视觉上分离出来,为术前准确诊断、手术方案个体化规划和手术入路选择提供决策。

中央型肝癌三维可视化精准诊疗中国专家共识(2020版)

中央型肝癌由于其位置的特殊性,传统手术方式是行左、右半肝或左、右三肝切除,常须切除60%~80%的肝脏,术中发生大出血及严重肝功能衰竭的风险均非常高。目前,对肝功能良好、无肝硬化的中央型肝癌病人常推荐行肝中区切除术。肝中区切除多属于复杂性肝脏外科手术,手术风险较高。同时,肝中区切除术后两个肝脏断面贴近血管和胆管的主干,术后发生胆漏、出血的风险高。在我国,80%~90%的肝癌病人伴有不同程度的肝硬化,因而个体化手术规划对手术的安全实施、保留更多的肝实质非常重要。近年来,三维可视化(three-dimensional visualiza?tion)技术应用于中央型肝癌的术前规划,在一定程度上提高了术前规划准确性和手术安全性。随着虚拟现实(virtu?al reality,VR)、吲哚菁绿荧光融合影像(fusion indocyanine green fluorescence imaging,FIGFI)等技术在临床的应用,丰富了术中评估的手段,并可指导手术实施。为规范和标准化上述技术在中央型肝癌诊治中的应用,中华医学会数字医学分会、中国研究型医院学会数字智能化外科专业委员会和中国医师协会肝癌专业委员会组织国内相关领域专家制定本共识。