Ventricular assist device support in children and adolescents with heart failure: the Children's Medical Center of Dallas experience

Children with heart failure unresponsive to medical therapy are left with few options for survival. Ventricular assist devices (VADs) are life-saving options for such patients, allowing for bridge to transplantation or cardiac recovery. Retrospective review of cases from May 2006 to October 2010 was undertaken. Fourteen patients underwent implantation of VADs for refractory heart failure. Mean age was 9 years (range 1-17 years), and weight was 41 kg (range 9.7-71 kg). Indications for support: end-stage cardiomyopathy (n = 8), myocarditis (n = 3), univentricular failure (n = 2), and congenital heart disease/postcardiotomy (n = 1). Level of limitation at time of implant included critical cardiogenic shock in six (43%) and progressive decline in eight (57%). Extracorporeal membrane oxygenation was used as a bridge to VAD in five (36%) patients. Preimplant variables: 86% of patients requiring mechanical ventilation (mean 10.3 days), hyperbilirubinemia in 75%, and acute renal insufficiency in 79%. Device selection was systemic VAD in 11 (79%) and biventricular assist device in three (21%). Berlin Heart EXCOR was used in eight patients, while six patients received a Thoratec implantable VAD or paracorporeal VAD. Mean duration of support was 68 days (range 8-363 days). Overall survival was 79%. Ten patients (71%) were successfully bridged to transplantation, three (21%) died while on a device, one remains on support, and no patients were weaned from VAD. Children supported for single ventricle heart failure had a 50% survival with none currently bridged to transplantation. Complications included bleeding requiring reoperation in 21% (n = 3), stroke in 29% (n = 4), and driveline infections in 7% (n = 1). In two patients, a total of six pump exchanges were performed for thrombus formation. Survival for pediatric patients of all ages is excellent using current device technology with a majority of patients being successfully bridged to transplantation. Morbidity is acceptably low considering the severity of illness. Significant challenges exist with long-term extracorporeal support due to lack of donor availability and the high incidence of preformed alloantibodies especially in the failing single ventricle.     

射频凝血器在原发性肝癌切除术中的应用

目的 探讨射频凝血器在原发性肝癌切除术中的应用价值.方法 回顾性分析2010年1月至2012年2月西安交通大学医学院第一附属医院收治的82例行手术切除的原发性肝癌患者的临床资料,根据其手术方式不同将患者分为射频止血肝切除组(41例)和常规钳夹肝切除组(41例),通过对两组患者的临床资料进行分析,评价射频凝血器的应用价值.计量资料采用t检验,计数资料采用x2检验.结果 射频止血肝切除组平均手术时间(77±28) min,比常规钳夹肝切除组的(129±34) min明显缩短(t=7.432,P＜0.05);射频止血肝切除组肝门阻断4例,较常规钳夹肝切除组的23例明显减少(x2=19.934,P＜0.05);射频止血肝切除组和常规钳夹肝切除组术中出血量分别为(241±214) ml和(751 ±421) ml,术中输血患者比例分别为15％ (6/41)和49％(20/41),两者比较,差异均有统计学意义(t=6.920,x2=11.038,P＜0.05).射频止血肝切除组和常规钳夹肝切除组在术后出血发生率、术后胆汁漏发生率方面比较,差异无统计学意义(x2=0.213,1.822,P＞0.05);射频止血肝切除组术后住院时间为(9±4)d,比常规钳夹组的(12±7)d明显减少(t=2.368,P＜0.05).两组均无围手术期死亡患者.结论 新型手术辅助器械射频凝血器能够有效地控制出血、减少手术时间,缩短术后住院时间,在原发性肝癌手术治疗中有较大的应用价值.     

一种新型低温静脉输液装置对中枢性高热患者的降温效果及安全性研究

背景　物理降温方法是中枢性高热患者的主要降温方法,目前临床上常用的物理降温方法效果报道不一,且存在较明显的并发症。目的　探讨一种新型低温静脉输液装置（国家实用新型专利,专利号：ZL 2014 2 0070586.4）对中枢性高热患者进行物理降温治疗的效果及安全性。方法　选取2015-2019年佛山市中医院重症医学科收治的中枢性高热患者93例,采用随机数字表法将其分为对照组（n=29）、普通静脉降温组（n=32）和应用降温装置组（n=32）。对照组给予基础治疗及体表物理降温,普通静脉降温组在对照组的基础上予以静脉输注低温液体（由冰箱冷藏4 ℃）,应用降温装置组则在对照组的基础上采用新型低温静脉输液装置输注室温液体。检测三组患者治疗前、治疗24 h及治疗48 h后的凝血功能指标：纤维蛋白原（FbgC）、活化部分凝血活酶时间（APTT）、凝血酶原时间（PT）及血小板计数（PLT）;观察寒战、心律失常、皮肤受损等并发症发生率;测量治疗前及治疗2、4、8、12、24、48 h的肛温;评估治疗1周后格拉斯哥昏迷量表（GCS）评分;电话随访患者治疗28 d病死率。结果　治疗方法和时间对FbgC、APTT、PT及PLT不存在交互作用（P>0.05）;治疗方法和时间对FbgC、APTT、PT及PLT主效应均不显著（P>0.05）。应用降温装置组寒战发生率低于对照组和普通静脉降温组,皮肤受损发生率低于对照组（P<0.017）。治疗方法和时间对肛温存在交互作用（P<0.05）;治疗方法和时间对肛温主效应均显著（P<0.05）;其中应用降温装置组治疗2、4、8、12、24、48 h的肛温均低于对照组和普通静脉降温组（P<0.05）。治疗1周后应用降温装置组GCS评分高于对照组和普通静脉降温组（P<0.05）。三组患者治疗28 d病死率比较,差异无统计学意义（P>0.05）。结论　采用新型低温静脉输液装置对中枢性高热患者进行物理降温治疗具有快速且稳定的降温效果,且其并发症发生率低,可广泛应用于临床降温治疗。     

经椎间孔内镜技术穿刺路径辅助定位器的设计与临床应用

目的 :阐述新型经椎间孔内镜技术穿刺路径辅助定位器(椎间孔镜定位器)的设计原理与使用方法 ,初步探索其对椎间孔镜手术穿刺的准确性、透视次数和手术时间的影响。方法:研制了新型椎间孔镜定位器,其设计原理主要是利用穿刺目标点始终落在直角圆弧圆心的特点实现导向穿刺。我们回顾性分析2015年5月1日~7月10日在我院接受椎间孔镜手术的患者,共纳入54例患者,男23例,女31例。使用椎间孔镜定位器进行穿刺的病例作为A组,使用传统穿刺方法的病例作为B组。记录并比较两组的穿刺次数、透视次数、手术时间和并发症等组间差异。结果:平均穿刺次数A组为1.22±0.57次,B组为5.89±1.91次,两组间具有显著性差异(P0.001)。平均透视次数A组为14.15±2.63次,B组为21.96±4.06次,两组间具有显著性差异(P0.001)。手术时间A组为81.37±10.62min,B组为90.41±14.37min,两组间有显著性差异(P=0.011)。两组之间均无重大并发症的发生,仅A组发现术后椎间盘残留1例,两组间并发症发生率无显著性差异(P=0.313)。结论:新型椎间孔镜定位器可以有效提高椎间孔镜穿刺的准确性,降低透视次数以及有效减少手术时间。     

释放左旋18-甲基炔诺酮(20μg)宫内节育器的研究回顾

目的总结我所对释放20μg左旋18甲基炔诺酮宫内节育器(LNGIUD)的研究,以阐明其作用机理、长效避孕效用和安全性。方法本文是我所发表的22篇临床报告和研究论文的综合分析。结果观察100例避孕效果,使用8年仅1例妊娠,续用率为52%,因医学原因取器为32.2%。观察10例随访1年有排卵周期者占44.8%,置器6年后,14例中有排卵周期者占78.5%;血清LNG水平有排卵者低,无排卵者高,提示闭经是高浓度LNG对子宫内膜的局部作用。形态学观察显示置器后子宫内膜增生受到抑制,内膜细胞核DNA含量明显下降,内膜细胞雌激素受体(ER)、孕激素受体(PR)表达受到抑制,内膜血管细胞因子VIII(FVIII)活性明显减低。提示月经的改变是LNGIUD对子宫内膜的局部作用。观察34例特发性月经过多的治疗达3年,月经血量(MBL)显著下降,血红蛋白(Hb)和铁蛋白明显增加。结论释放20μg的LNGIUD是一个安全、高效、长效、可逆的避孕方法。主要优点是降低MBL,可接受性高,适合于我国实际应用。尤其对月经过多和贫血的妇女,更应优先选择。     

椎弓根螺钉植入导向器的研制及体外应用研究

目的　分析自制椎弓根螺钉导向器提高椎弓根螺钉植入的准确性。　方法　根据椎弓根的解剖特点 ,研制椎弓根螺钉植入导向器。用多层螺旋 CT测量 2具胸椎标本 (T1 ～ T1 0 )椎弓根的三维定量解剖数据。依据其中轴的水平位角 (transverse section angle,TSA)和矢状位角 (sagittal section angle,SSA)值 ,调节导向器水平和矢状刻度盘角度。植入螺钉后拔出 ,用显影剂填充钉道。 CT测量显影钉道的 TSA和 SSA值。　结果　析因设计资料方差分析显示 ,椎弓根显影钉道的 TSA、SSA与其中轴的 TSA、SSA间差异无统计学意义 (P>0 .0 5 )。　结论　椎弓根螺钉导向器操作简便 ,其导向使钉道达到理想角度 ,能减少椎弓根穿破的发生。     

Phantom-based assessment of motion and needle targeting accuracy of robotic devices for magnetic resonance imaging-guided needle biopsy

Background

The current study proposes simple methods for assessing the performance of robotic devices intended for Magnetic Resonance Imaging (MRI)-guided needle biopsy.

Methods

In-house made agar-based breast phantoms containing biopsy targets served as the main tool in the evaluation process of an MRI compatible positioning device comprising a needle navigator. The motion accuracy of mechanical stages was assessed by calliper measurements. Laboratory evaluation of needle targeting included a repeatability phantom test and a laser-based method. The accuracy and repeatability of needle targeting was also assessed by MRI.

Results

The maximum error of linear motion for steps up to 10 mm was 0.1 mm. Needle navigation relative to the phantom and alignment with the various biopsy targets were performed successfully in both the laboratory and MRI settings. The proposed biopsy phantoms offered tissue-like signal in MRI and good haptic feedback during needle insertion.

Conclusions

The proposed methods could be valuable in the process of validating the accuracy of MRI-guided biopsy robotic devices in both laboratory and real environments.     

闭合性胫骨骨折兔模型的建立与评估

目的：探讨改良设计的三点弯曲骨折装置用于建立闭合性胫骨骨折兔模型的效果。方法：选取6月龄SPF级健康雄性新西兰兔40只,体质量2.5~3.0 kg,制备闭合性胫骨骨折兔模型,并于术后6周进行模型验证。预造模组5只,造模前未行临时外固定,后以改良设计三点弯曲骨折装置进行骨折;正式造模组35只,造模前行穿针及夹板外固定,后以改良设计三点弯曲骨折装置进行骨折。于术后2 h及4、6周行影像学、组织病理学评估骨折模型情况及愈合进程。结果：造模后2 h,预造模组呈不同程度的斜行骨折且断端明显移位;正式造模组除1只粉碎性骨折,2只弯曲蝶形骨折,2只未显示明显骨折线外,其余均呈简单横行及斜行骨折,断端无明显移位。根据判定标准,模型成功率为85.71%。造模后4周,实验兔固定针及夹板位置良好,骨折对位对线良好,骨折线已模糊不清,骨折端周围可见大量连续骨痂生长,骨痂密度较高。造模后6周,镜下见骨折处大量粗大的新生骨小梁,边缘成骨细胞附着并见少量巨噬细胞,膜内成骨区域为编织骨阶段,骨折处髓腔已部分再通,骨痂处于吸收塑性阶段,可见大量破骨细胞。X线显示骨折线几乎消失,髓腔部分已通,周围见外骨痂减少,骨痂处于塑形期,骨皮质连续。提示骨折模型呈二期愈合。结论：改良三点弯曲骨折装置可建立稳定的闭合性胫骨骨折兔模型,且操作简便,符合骨折愈合相关基础研究对闭合性骨折模型的要求。     

伞状记忆合金股骨头支撑器及器械的设计

目的：根据镍钛记忆合金的特性,设计一款操作简便,支撑力强的股骨头支撑器,用以治疗成人股骨头缺血性坏死。方法：采用记忆合金板材通过线切割、毛坯光整、热成型、热处理等工艺流程制成股骨头支撑器,并生产相应的手术器械。然后对股骨头支撑器进行有限元静态和载荷分析。结果：静态应力分析结果显示,最大应力为1500 MPa。位移变形分析显示,最大位移为1.75mm。结论：根据有限元分析,伞状记忆合金股骨头支撑器微创治疗股骨头坏死,符合股骨头的生物力学优势,可起到预防股骨头塌陷的作用。     

In Vitro Evaluation of the Dual‐Diffuser Design for a Reversible Rotary Intra‐Aortic Ventricular Assist Device

The intra‐aortic ventricular assist device (IntraVAD) is a miniature intra‐aortic axial‐flow ventricular assist device (VAD) that works in series with the left ventricle (LV) to assist the compromised heart. Previous in vitro results have shown that the IntraVAD can successfully increase coronary perfusion and offload ventricular volume by operating in reverse‐rotation control (RRc) mode. The RRc mode includes forward rotation in systole and reverse rotation (RR) in diastole. It is necessary to derive a new diffuser design that can be used for the bi‐directional rotation of the IntraVAD. In this work, a dual‐diffuser set (DDS) was proposed to replace the conventional inducer and diffuser upstream and downstream of the pump. The DDS comprised two diffusers, located on both sides of the impeller, omitting the conventional inducer and diffuser. Different configurations of the DDS were designed and manufactured with various combinations of curved and straight blades. All configurations were initially tested in continuous flow, then in a pulsatile mock circulatory loop. A weighted normalized scalar (WNS) was proposed to comprehensively evaluate the hemodynamic effect of the DDS with different configurations. The results show that the maximum of WNS occurred when the upstream diffuser had equal numbers of curved and straight blades and the downstream diffuser had only curved blades. This indicates such a dual‐diffuser design for the IntraVAD can give an optimal cardiac assistance potentially improving ventricular contractility, thereby restoring heart function.