三棱滑切固定矫治器--结构设计与应用原理

目的开发设计一种新型的固定矫治器：三棱滑切固定矫治器，用于牙颌畸形的正畸治疗，对其结构设计和应用原理进行探讨分析。方法三棱滑切固定矫治器的结构，以三棱形弓丝和具有三角槽沟的托槽为主体，由它控制矫治牙在各个方向的移动而发挥矫治作用。结果对该矫治器的结构做出定性设计，分析探讨其调控牙齿正畸移动的方式主要为通过三棱弓丝的一个刃状边棱与托槽三角沟槽的一个边面相切，借助于弓丝本身的弹性形变力和弓丝的外加引导力而对矫治牙齿施以滑动和切入机制的矫治力。结论三棱形弓丝和与之匹配的三角槽沟托槽是这类矫治器的主要结构特征；角——槽切合锁入式结构设计在确保弓丝与槽沟完全吻合的条件下实现了弓丝入槽——出槽顺畅自由，易于临床使用和精确调控牙位的目的；“棱面相切——加力引导切入——渐进式加力”到牙齿，更加符合持续、轻力的现代口腔正畸施力原则．     

Ramp rate of blood pressure changes does not affect aortic afferent sensitivity in anesthetized rats

To investigate whether the rate of change in blood pressure affects the sensitivity of the aortic baroreceptor afferent response, the change in aortic nerve activity (ANA) to two different rates of ramp increase in mean blood pressure (MBP), elicited by phenylephrine administration, was determined in the rat under urethane (1.5 g kg⁻¹) anesthesia. The sensitivity of the increase in ANA following a rapid (average ramp rate, 9.14 ± 0.60 mmHg s⁻¹, n = 11) or gradual (1.78 ± 0.24 mmHg s⁻¹, n = 11) increase in MBP was 2.03 ± 0.14% and 1.81 ± 0.20% of baseline mmHg⁻¹, respectively. These values were not significantly different from each other (P = 0.16). Furthermore, we found no correlation between the rate of ramp increase in MBP and the sensitivity of the increase in ANA (r = 0.24, P = 0.29, n = 22). These results suggest that, at least within the normal physiological range of MBP, the rate of the ramp change in blood pressure does not affect aortic baroreceptor afferent sensitivity in the anesthetized rat.     

食管胸段前鄰器官的定位研究

本文测量了58具成年尸体食管胸段的长度,用内外相关和自身比例的方法,着重对食管胸段前邻器官的占位及其在胸骨上的投影作了定位研究,并结合临床应用进行了讨论。     

枢椎侧弓螺钉安全钉道的判定与测量

目的:利用Unigraphics(UG)三维重建技术寻找枢椎侧弓螺钉安全钉道的经过,并进行相关参数的测量.方法:对4例干燥和8例新鲜枢椎行CT扫描, UG软件重建虚拟实体,利用3.5 mm虚拟螺钉模拟进钉,寻找安全钉道经过的特征标记点.以此为基础,测定57例干燥枢椎安全钉道的内倾角与上倾角(AutoCAD环境)及进针点距峡部及下关节突外缘的距离(手工测量).结果:模拟发现横断面安全钉道经过前弓中宽后界的内中1/3交界与中宽前界的外中1/3交界,矢状面经过前弓中宽后界中部及前界中宽与上关节突下界交界处.对另57例干燥标本进行测量发现安全钉道的内倾角为左/右＝(10.94±6.53)°/(11.95±2.82)°,上倾角为(13.31±5.44)°/(14.45±3.80)°,在大多数标本椎板后下方有一突起的骨嵴 (左/右＝84.2%/84.98%) ,进针点多位于这一骨嵴线上(左/右＝87.5%/84.9%).进针点距离下关节外侧缘左/右＝(6.71±1.33)mm/(6.28±1.48)mm,距离后弓左/右＝(9.93±1.38)mm/(8.47±1.70)mm.个体间差异较大.结论:侧方椎弓螺钉固定的安全钉道在横断面经过横突孔区域(侧弓前份)中宽后界的内中1/3交界与中宽前界的外中1/3交界,矢状面经过后方中宽中部及前方中宽与关节突下界交界处,不同侧别间及不同个体间有明显差别.     

A new balloon catheter for selective cerebral perfusion

Selective cerebral perfusion (SCP) is a better method than hypothermic circulatory arrest for brain protection in aortic arch surgery because of fewer time limitations; however; it is more troublesome during surgery. We developed a new catheter for SCP, the SP Stud catheter, with a rib-surface balloon to reduce slipping to eliminate the need for snaring or clamping. To evaluate the slipping resistance of the new catheter, we compared it with two different balloon catheters; a Foley balloon catheter with a smooth-surface balloon as long as the SP Stud catheter, and a Retro-TH catheter with a smooth-surface balloon of discoid shape half as long as the SP Stud catheter. The “draw-strength”, which refers to the slipping resistance, was measured in 20 autopsy carotid arteries in the three groups. The average draw-strengths of SP Stud catheter, foley balloon catheter, and Retro-TH catheter were 92.3±4.0, 20.8 ±1.5, and 17.9±0.8g, respectively, in sclerotic carotid arteries. The SP Stud catheter demonstrated approximately four times more resistance to slipping than the Foley balloon or Retro-TH catheters. The SP Stud catheter demonstrated a higher slipping resistance than conventional catheters, which may allow selective cerebral perfusion without snaring or clamping the carotid arteries, minimize the change of cerebral embolism, and clear the operative field.     

A modified frozen elephant trunk hybrid device to facilitate supra‐aortic trunk anastomosis

Reimplantation of the supra‐aortic vessels can be challenging with Thoraflex Hybrid. A device modification made the vessel lengths more appropriate and the position of the neo‐vessels in the chest avoided malpositioning and kinking and facilitated sternum closure; this may improve operating times as well as allowing complete and continuous cerebral trivascular perfusion and corrects positioning of the intrathoracic vessels.     

Use of VA ECMO and percutaneous palliation of ductal dependent coarctation in a neonate with trisomy 21 and COVID-19 pneumonia

We present a case of a neonate with trisomy 21, ductal-dependent aortic coarctation, and severe respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia. The neonate was managed with venoarterial extracorporeal membrane oxygenation (VA ECMO), palliative stenting of the coarctation, and a vascular plug occlusion of a large patent ductus arteriosus. The patient was successfully weaned off extracorporeal membrane oxygenation (ECMO). The patient is currently awaiting a definitive surgical repair in the near future.     

Cardiac function in adolescents and young adults with 22q11.2 deletion syndrome without congenital heart disease

BackgroundDiagnosis and treatment of 22q11.2 deletion syndrome (22q11.2DS) have led to improved life expectancy and achievement of adulthood. Limited data on long-term outcomes reported an increased risk of premature death for cardiovascular causes, even without congenital heart disease (CHD). The aim of this study was to assess the cardiac function in adolescents and young adults with 22q11.2DS without CHDs.MethodsA total of 32 patients (20M, 12F; mean age 26.00 ± 8.08 years) and a healthy control group underwent transthoracic echocardiography, including Tissue Doppler Imaging (TDI) and 2-dimensional Speckle Tracking Echocardiography (2D-STE).ResultsCompared to controls, 22q11.2DS patients showed a significant increase of the left ventricle (LV) diastolic and systolic diameters (p = 0.029 and p = 0.035 respectively), interventricular septum thickness (p = 0.005), LV mass index (p < 0.001) and aortic root size (p < 0.001). 2D-STE analysis revealed a significant reduction of LV global longitudinal strain (p < 0.001) in 22q11.2DS than controls. Moreover, several LV diastolic parameters were significantly different between groups.ConclusionsOur results suggest that an echocardiographic follow-up in 22q11.2DS patients without CHDs can help to identify subclinical impairment of the LV and evaluate a potential progression of aortic root dilation over time, improving outcomes, reducing long-term complications and allowing for a better prognosis.     

DeBakey工、Ⅱ型主动脉夹层的外科治疗

目的　总结DeBakeyI、Ⅱ型主动脉夹层的外科治疗经验 ,探讨其手术指征、基本方法和手术技术。方法　对 131例DeBakeyⅠ、Ⅱ型主动脉夹层患者实施手术治疗 ,其中 2 5例行升主动脉 部分主动脉弓替换术 ,83例行主动脉根部替换术 (Bentall′s手术 ) ,10例行升主动脉替换 全弓替换术 ,4例行细胞感升主动脉替换 主动脉瓣替换术 (Wheats) ,3例行主动脉根部替换术 全弓替换术 ,4例行“象鼻手术”(ElephantTrunk) ,2例行主动脉根部替换 象鼻技术。结果　本组死亡 4例 ,死亡率 3.0 5 %。急诊手术 44例 ,死亡 3例 ,死亡率 6 .81%。择期手术 87例 ,死亡 1例 ,死亡率 1.1%。结论　早期手术治疗是降低DeBakeyⅠ、Ⅱ型主动脉夹层病死率的关键。右锁骨下动脉插管 ,深低温停循环结合选择性脑灌注是一种简便易行的脑保护方法 ,有利于降低该病死亡率和并发症的发生率。