Differences between main-duct and branch-duct intraductal papillary mucinous neoplasms of the pancreas

In the last decade,intraductal papillary mucinous neoplasms(IPMNs) have become commonly diagnosed.From a morphological standpoint,they are classified in main-duct IPMNs(MD-IPMNs) and branch-duct IPMNs(BD-IPMNs),depending on the type of involvement of the pancreatic ductal system by the neoplasm.Despite the fact that our understanding of their natural history is still incomplete,recent data indicate that MD-IPMNs and BD-IPMNs show significant differences in terms of biological behaviour with MD-IPMNs at higher risk of malignant degeneration.In the present paper,clinical and epidemiological characteristics,rates of malignancy and the natural history of MD-IPMNs and BD-IPMNs are analyzed.The profile of IPMNs involving both the main pancreatic duct and its side branches(combined-IPMNs) are also discussed.Finally,general recommendations for management based on these differences are given.

Evolution of incidental branch-duct intraductal papillary mucinous neoplasms of the pancreas: A study with magnetic resonance imaging cholangiopancreatography

AIM To investigate the type and timing of evolution of incidentally found branch-duct intraductal papillary mucinous neoplasms(bd-IPMN) of the pancreas addressed to magnetic resonance imaging cholangiopancreatography(MRCP) follow-up.METHODS We retrospectively evaluated 72 patients who underwent, over the period 2006-2016, a total of 318 MRCPs(mean 4.4) to follow-up incidental, presumed bdIPMN without signs of malignancy, found or confirmedat a baseline MRCP examination. Median follow-up time was 48.5 mo(range 13-95 mo). MRCPs were acquired on 1.5T and/or 3.0T systems using 2D and/or 3D technique. Image analysis assessed the rates of occurrence over the follow-up of the following outcomes:(1) imaging evolution, defined as any change in cysts number and/or size and/or appearance; and(2) alert findings, defined as worrisome features and/or high risk stigmata(e.g., thick septa, parietal thickening, mural nodules and involvement of the main pancreatic duct). Time to outcomes was described with the Kaplan-Meir approach. Cox regression model was used to investigate clinical or initial MRCP findings predicting cysts changes.RESULTS We found a total of 343 cysts(per-patient mean 5.1) with average size of 8.5 mm(range 5-25 mm). Imaging evolution was observed in 32/72 patients(44.4%; 95%CI: 32-9-56.6), involving 47/343 cysts(13.7%). There was a main trend towards small(< 10 mm) increase and/or decrease of cysts size at a median time of 22.5 mo. Alert findings developed in 6/72 patients(8.3%; 95%CI: 3.4-17.9) over a wide interval of time(13-63 mo). No malignancy was found on endoscopic ultrasound with fine-needle aspiration(5/6 cases) or surgery(1/6 cases). No clinical or initial MRCP features were significantly associated with changes in bd-IPMN appearance(P > 0.01).CONCLUSION Changes in MRCP appearance of incidental bd-IPNM were frequent over the follow-up(44.4%), with relatively rare(8.3%) occurrence of non-malignant alert findings that prompted further diagnostic steps. Changes occurred at a wide interval of time and were unpredictable, suggesting that imaging followup should be not discontinued, though MRCPs might be considerably delayed without a significant risk of missing malignancy.

面神经颊支与腮腺导管的路径分析

目的探究国人面神经颊支与腮腺导管的解剖学关系,为外科医生行颌面部手术及面部整形手术提供形态学基础和参考。方法选取20例经福尔马林固定的尸体半侧脸。排除肿瘤、外伤、畸形、手术等导致的面部缺陷样本。测量面神经颊支交点到腮腺导管起始点的距离,以及上下颊支到腮腺导管的垂直距离,计数面神经颊支与腮腺导管交点的个数。结果在20例半面中,颊支与腮腺导管的交点数为2~19个,平均(4.75±3.71)个。交点到腮腺导管起始点的距离为1.29~41.38 mm。颊分支的数量为3~7个。上颊支起始点到腮腺导管起始点的距离为5.06~28.51 mm,平均(13.26±5.94)mm。下颊支起始点到腮腺导管起始点的距离为2.15~46.63 mm,平均(9.63±10.20)mm。面神经颊支与腮腺导管的关系分成四种类型,其中以Ⅲ型上下颊支形成颊丛最常见。结论面神经颊支与腮腺导管关系密切,走行复杂,掌握面神经颊支与腮腺导管的关系,有助于减少颌面部手术及面部整形手术中的损伤,提高手术成功率。

支风道高度对浅圆仓径向通风的影响

机械通风是粮食仓储过程中调控粮堆温湿度、保证储粮品质的有效方法。浅圆仓通常采用地槽通风,但存在通风均匀性差、阻力大、能耗高等问题。目前,浅圆仓径向通风技术研究逐步深入,其通风管网的合理布置是浅圆仓径向通风技术标准化应用和确保其通风效率的关键。本文通过数值模拟的方法,研究了支风道高度对浅圆仓径向通风流场、降温速率、降温均匀性及水分损耗的影响。结果表明,浅圆仓直径为25 m,装粮线20 m时,支风道高度为12.5 m时粮堆降温速率最大,可达到0.051℃/h,粮堆温度变异系数整体达到15.61%;浅圆仓径向通风系统支风道高度h与粮堆平均降温速率Y的满足Y=0.0203+0.00386 h-1.22×10^(-4) h^(2)方程,R^(2)值为0.97;支风道高度的增加对粮堆整体水分影响较小,但是对粮堆表面水分影响较大。

新型纺织车间多风机送风系统运行优化

探讨新型纺织车间多风机送风系统运行设计优化方法。针对新型纺织车间需要多台风机并联送风的问题,依据轴流风机并联运行特性规律,结合常用的多风机并联运行系统形式和特点,分析影响并联风机性能的主要因素。提出并联风机设计选型时风机型号、规格、台数、运行速度、公用回路阻力等参数的基本要求。认为:并联各风机型号、规格、运行速度应尽量一致,公用回路阻力应保证在最低风机全压的30%以内,各风机送风回路压力损失之和的差异要小于10%。

磁共振胆胰管成像显示分支胰管扩张的意义

目的 探讨分支胰管扩张的磁共振胆胰管成像（MRCP）表现及其对胰腺疾病的诊断价值。资料与方法 MRCP使用Signa Excite HD3.0T MR设备,研究对象为MRCP影像显示分支胰管扩张的病人,包括慢性胰腺炎45例与胰腺癌30例,所有病人均进行常规横断面T1WI、T2WI和MRCP。分析分支胰管扩张的形态、部位及程度,比较2组疾病分支胰管扩张的差异。结果 在形态方面,慢性胰腺炎组分支胰管扩张呈小囊状、分支状及两者兼有的病例数分别为19、42和16例;而胰腺癌组分别为6、29和5例。在部位方面,慢性胰腺炎组分支胰管扩张位于主胰管近段、远段及全程的病例数分别为0、10和35例;而胰腺癌组分别为1、12和17例。结论 3.0T MRCP能清晰显示主胰管及扩张的分支胰管。认识分支胰管扩张的特征有助于慢性胰腺炎和胰腺癌的鉴别诊断。

面神经下颌缘支和颊支的应用解剖学研究

目的:了解面神经下颌缘支和颊支的正常层次解剖位置,面神经下颌缘支与面动脉以及面神经颊支与腮腺导管的位置关系,为防止面侧区颌面部手术中造成面神经下颌缘支和颊支损伤提供解剖学依据。方法:对20具(40例)成人尸体面侧区进行层次解剖寻找面神经下颌缘支和颊支及用游标卡尺测量相关数据。结果:面神经下颌缘支单干型居多,占57.5%,双干型占27.5%,合干型占15.0%;出腮腺后走行于下颌骨下缘的上方、下方及基本平行,各占65.0%、12.5%、22.5%;面神经下颌缘支经过面动脉的浅面、深面及两支经其浅面或深面夹持或环抱面动脉,然后合成1支者分别占89.5%、7.0%、3.5%。面神经颊支以双干型居多,占57.5%,单干型占12.5%,三干型占27.5%,四干型占2.5%;位于腮腺导管上方的颊支占52.3%,位于腮腺导管下方的颊支占47.7%。结论:掌握面神经下颌缘支和颊支的走行,下颌缘支与面动脉的关系位置,颊支与腮腺导管的位置关系,以满足颌面部外科手术的需要。

面神经颊支的应用解剖

目的:观测分析面神经颊支的分支类型及其与腮腺管之间的解剖关系,为腮腺区手术提供解剖学基础。方法:60例成人头部标本,观测面神经颊支的分支类型、行程、神经与腮腺管的位置关系。结果:面神经颊支以双干型多见(58.3％),三干型次之(28.3％)。神经多行于腮腺管浅面(73.3％)。腮腺管走行在颊支之间的占61.7％,导管距上颊支垂直距离约4.86 mm;腮腺管走行在神经下方者占11.7％,距下颊支的垂直距离约1.71 mm;腮腺管走行在神经上方者占26.7％,距上颊支的垂直距离约2.56 mm。结论:面神经颊支多行于腮腺管浅层,与腮腺管关系十分密切,腮腺区手术时循颊支向后追踪面神经是比较安全、有效的方法,容易掌握。

腮腺浅部第1叶间导管与面神经颧支的解剖学关系

目的探讨腮腺叶间导管转移治疗干眼病的解剖学基础。方法对5具(10侧)成人尸体标本头面部腮腺区进行局部解剖,观察腮腺第1叶间导管与面神经颧支的关系,测量两者的相关数据。结果腮腺浅部第1叶间导管长度为(37.51±1.23)mm,注入腮腺导管处的外径为(0.53±0.15)mm。面神经颧支与腮腺第1叶间导管逆向而行,两者解剖关系密切。结论腮腺叶间导管转位治疗干眼病手术方式可供临床参考。

谷冷机制冷降温储粮试验

采用回风管和一机四道的风道设计 ,进行了谷冷机制冷低温储粮试验和复冷试验 。

面神经颊支与腮腺导管的解剖关系

目的 观测分析面神经颊支的分支类型及其与腮腺导管之间的位置关系 ,为腮腺区手术提供解剖学基础。方法 解剖 5 0例成人头部标本 ,观测面神经颊支的分支类型、行程、神经与腮腺导管的位置关系。结果 面神经颊支以双干型多见 ( 60 % )。神经多行于腮腺导管浅面为主 ( 74% )。腮腺导管走行在颊支之间占大部分( 62 % ) ,导管距上颊支垂直距离约 4.73±1 .96mm。结论 面神经颊支多行于腮腺导管浅层 ,与腮腺导管关系十分密切 。

腮腺良性肿瘤切除术中腮腺导管和面神经颊支解剖关系的观察

目的观察研究腮腺导管与面神经颊支的解剖关系,为术中用腮腺导管作为面神经探查标记物提供解剖依据。方法在腮腺良性肿瘤切除术中观察和测量42例患者的腮腺导管和面神经颊支的解剖关系,包括深浅、成角和距离关系。结果在深浅关系上,颊支位于腮腺导管浅面占69.05%(29/42),同层面占14.29%(6/42),深面占16.67%(7/42)。从二者走形角度上,基本平行占76.19%(32/42),明显成角的占23.81%(10/42)。以出腮腺处测量距离来看,上颊支位于腮腺导管上0.2~1.0 cm,平均(0.61±0.13)cm;下颊支位于导管下0.2~1.5 cm,平均(0.77±0.27)cm。结论腮腺导管与面神经上下颊支解剖关系相对恒定,可以用于腮腺肿瘤术中寻找解剖面神经的标志物。

气力输送分支管分流处局部阻力特性分析

在上引式流态化气力输送试验台上,对3种不同角度分支管进行输送试验,分析管路分流处局部阻力损失的变化规律,并拟合分支管局部阻力特性方程;同时以试验所得参数为基础,采用fluent软件对分支管段分流情况进行数值模拟。研究结果显示,分支管局部阻力损失随管道内固气比和表观气速的增大而增大,当表观气速为8 m/s时达到了输送系统的沉积速度;误差分析表明所得拟合方程有较高准确性;模拟结果显示在管道分流处湍流现象明显并有较大的漩涡出现,且分支角度越大,湍流和漩涡现象越明显。

Differential diagnosis of benign and malignant branch duct intraductal papillary mucinous neoplasm using contrastenhanced endoscopic ultrasonography

AIM: To elucidate the role of contrast-enhanced endoscopic ultrasonography(CE-EUS) in the diagnosis of branch duct intraductal papillary mucinous neoplasm(BD-IPMN).METHODS: A total of 50 patients diagnosed with BDIPMN by computed tomography(CT) and endoscopic ultrasonography(EUS) at our institute were included in this study. CE-EUS was performed when mural lesions were detected by EUS. The diagnostic accuracy for identifying mural nodules(MNs) was evaluated by CT, EUS, and EUS combined with CE-EUS. In the patients who underwent resection, the accuracy of measuring MN height with each imaging modality was compared. The cut-off values to diagnose malignant BD-IPMNs based on MN height for each imaging modality were determined using receiver operating characteristic curve analysis.RESULTS: Fifteen patients were diagnosed with BD-IPMN with MNs and underwent resection. The remaining 35 patients were diagnosed with BD-IPMN without MNs and underwent follow-up monitoring. The pathological findings revealed 14 cases with MNs and one case without. The accuracy for diagnosing MNs was 92% using CT and 72% using EUS; the diagnostic accuracy increased to 98% when EUS and CE-EUS were combined. The accuracy for measuring MN height significantly improved when using CE-EUS compared with using CT or EUS(median measurement error value, CT: 3.3 mm vs CE-EUS: 0.6 mm, P < 0.05; EUS: 2.1 mm vs CE-EUS: 0.6 mm, P < 0.01). A cut-off value of 8.8 mm for MN height as measured by CE-EUS improved the accuracy of diagnosing malignant BDIPMN to 93%. CONCLUSION: Using CE-EUS to measure MN height provides a highly accurate method for differentiating benign from malignant BD-IPMN.

支风道进风端高风速技术实践

针对系统风量增加和等截面水平支风道截面积不变情况下实现支风道均匀送风问题 ,提出了纺织厂空调室技术改造方案 .技术实践表明 ,支风道进风端高风速可以实现均匀送风 .

Role of frozen section assessment for intraductal papillary and mucinous tumor of the pancreas

Intraductal papillary mucinous neoplasms(IPMN) of the pancreas include a spectrum of dysplasia ranging from minimal mucinous hyperplasia to invasive carcinoma and are extensive tumors that often spread along the ductal tree.Several studies have demonstrated that preoperative imaging is not accurate enough to adapt the extent of pancreatectomy and have suggested routinely using frozen sectioning(FS) to evaluate the completeness of resection and also to check if ductal dilatation is active or passive,in order to avoid an excessive pancreatic resection.Separate main duct and branch duct analysis is needed due to the difference in the natural history of the disease.FS accuracy averages 95%.Eroded epithelium on the main duct,severe ductal inflammation mimicking dysplasia and reactive epithelial changes secondary to obstruction can lead to inappropriate FS results.FS results change the planned extent of resection in up to 30% of cases.The optimal cut-off leading to extend pancreatectomy is not consensual and our standard option is to extend pancreatec-tomy if FS reveals:(1) at least IPMN adenoma on the main duct;or(2) at least borderline IPMN on branch ducts;or(3) invasive carcinoma.However,the decision to extend resection must be taken after a multidisciplinary discussion since it does not exclusively depend on the FS result but also on age,general condition and expected prognosis after resection.The main limitation of using FS is the existence of discontinuous("skip") lesions which account for approximately 10% of IPMN in surgical series and can lead to reoperation in up to 8% of cases.

Pathological features and diagnosis of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm(IPMN) of the pancreas is a noninvasive epithelial neoplasm of mucinproducing cells arising in the main duct(MD) and/or branch ducts(BD) of the pancreas.Involved ducts are dilated and filled with neoplastic papillae and mucus in variable intensity.IPMN lacks ovarian-type stroma,unlike mucinous cystic neoplasm,and is defined as a grossly visible entity(≥ 5 mm),unlike pancreatic intraepithelial neoplasm.With the use of high-resolution imaging techniques,very small IPMNs are increasingly being identified.Most IPMNs are solitary and located in the pancreatic head,although 20%-40% are multifocal.Macroscopic classification in MD type,BD type and mixed or combined type reflects biological differences with important prognostic and preoperative clinical management implications.Based on cytoarchitectural atypia,IPMN is classified into low-grade,intermediategrade and high-grade dysplasia.Based on histological features and mucin(MUC) immunophenotype,IPMNs are classified into gastric,intestinal,pancreatobiliary and oncocytic types.These different phenotypes can be observed together,with the IPMN classified according to the predominant type.Two pathways have been suggested:gastric phenotype corresponds to less aggressive uncommitted cells(MUC1-,MUC2-,MUC5 AC +,MUC6 +) with the capacity to evolve to intestinal phenotype(intestinal pathway)(MUC1-,MUC2 +,MUC5 AC +,MUC6- or weak +) or pancreatobiliary /oncocytic phenotypes(pyloropancreatic pathway)(MUC1 +,MUC 2-,MUC5 AC +,MUC 6 +) becoming more aggressive.Prognosis of IPMN is excellent but critically worsens when invasive carcinoma arises(about 40% of IPMNs),except in some cases of minimal invasion.The clinical challenge is to establish which IPMNs should be removed because of their higher risk of developing invasive cancer.Once resected,they must be extensively sampled or,much better,submitted in its entirety for microscopic study to completely rule out associated invasive carcinoma.

也谈变工况除尘系统风机调速计算方法

通过实例对单点变工况 ,双点、多点变工况 ,单点、多点变工况与定工况组合的变工况除尘系统进行分析 ,导出其风机调速的计算方法 ,并对其除尘特性进行了分析和总结。

高层住宅电气设计中的几点体会

针对高层住宅的电气设计工作,文章结合实际及建设单位与施工单位的反馈意见进行了总结,并有针对性地提出了自己的看法和措施。

分支胰管型胰腺导管内乳头状黏液瘤临床分析

目的探讨分支胰管型胰腺导管内乳头状黏液瘤(BD-IPMN)的治疗策略。方法结合最新文献复习回顾性分析2例BD-IPMN患者的临床资料。对BD-IPMN的治疗策略、恶变预测等进行探讨,以提高对BD-IPMN的认识和治疗水平。结果2例患者手术过程顺利。患者1术后出现B级胰瘘,患者2出现一过性生化瘘,均经通畅引流、对症及支持治疗后顺利出院。患者1病理提示IPMN伴局灶导管周围腺体不典型增生。患者2病理提示IPMN伴上皮轻-中度异型增生。随访6~12个月,2例患者均未发生复发、转移。结论BD-IPMN作为一种低恶性潜能的肿瘤,尚缺乏有效的指标或方法精准预测其恶性潜能。手术是目前唯一有效的治疗方法,但外科治疗策略的制定需结合患者的依从性、意愿,以及预期寿命和手术风险等因素。应谨慎把握老年及有严重合并症患者的手术指征。