非体外循环冠状动脉旁路移植术中转体外循环的原因探讨

目的　探讨非体外循环冠状动脉旁路移植术 (OPCAB)中转体外循环的原因与技术方法。方法　分析术前预计完成的非体外循环冠状动脉旁路移植术 4 34例 ,中转为体外循环下手术者 10例 (2 .3% )。中转原因包括 :顽固性心律失常 2例 ,搬动心脏时顽固低血压 2例 ,右冠急性阻塞缺血引起心率下降和血压降低 2例 ,心脏明显扩大而难以完全再血管化 2例 ,因完成的血管桥不通畅在体外循环下重新吻合 2例。结果　中转体外循环后 9例在并行循环心脏跳动下完成手术 ,1例在低温室颤下完成手术 ,体外循环时间为 (131.5± 4 0 .1)min。远端吻合口数目平均为 (3.5± 1.0 )个 ,使用主动脉内球囊反搏 6例。本组无住院死亡者。术后室颤 1例 ,除颤成功 ;房颤 2例 ,药物治疗好转。随访术后 6个月突发心律失常死亡 1例 ,考虑为晚期缺血性心肌病。结论　OPCAB手术存在中转体外循环的可能性。随着技术方法的改进和操作经验的积累 ,可减少中转事件的发生 ,进一步增加OPCAB的安全性和可行性。     

Voice prosthesis insertion after endoscopic balloon-catheter dilatation in case of a stenotic hypopharyngo-oesophageal junction

Stenosis of the hypopharyngo-oesophageal junction can be a rare complication of laryngectomy and/or partial pharyngectomy and makes the insertion of voice prosthesis extremely difficult. This study describes the authors’ experiences gained by endoscopic balloon-catheter dilatation of hypopharyngo-oesophageal stenoses prior to implantation of voice prostheses in four cases. In two patients a single balloon-catheter dilatation resulted in wide enough pharyngo-oesophageal lumen on the long run. The average prosthesis wearing-times were 6.8 months in case 1 and 4.6 months in case 2, corresponding to the published literature data. In case 3, repeated dilatation of the pharyngo-oesophageal transition had proved to be unsuccessful despite taking every effort with the endoscopic balloon-catheter method. Having excised the stenotic segment, reconstruction with pectoralis major myocutaneous flap (PMMF) was indicated. Eighteen months later, a repeated restenosis was observed and a free jejunal flap needed to be performed as a final solution. In case 4, the insertion was carried out into a previously dilated jejunal free flap, which became gradually ischemic and stenotic since the major head-and neck procedure was carried out that resulted in prosthesis rejection after just 1 week. The authors emphasize that correct indication of pedicled and free flaps in head and neck reconstruction is a prerequisite from the aspect of prevention of pharyngo-oesophageal strictures. Endoscopic balloon-catheter dilatation is a safe and established method for dilatating hypopharyngo-oesophageal stenoses of different origin. The procedure provides maximum patient benefit with minimal trauma and morbidity; moreover, facilitates insertion of voice prostheses. However, a single balloon-catheter dilatation cannot always result in wide enough oesophageal lumen on the long run (case 3). Insertion of a voice prosthesis into a previously dilated ischemic jejunal segment is challenging and avoidable due to risks of complications.     

可吸收球囊椎体成形术治疗胸腰椎爆裂骨折的实验研究

[目的]探讨结合短节段椎弓根螺钉系统撑开复位内固定的可吸收球囊椎体成形术治疗胸腰椎爆裂骨折的生物力学性能变化。[方法]采集6具新鲜固定湿润成人尸体胸腰椎标本，制成T11-L1，L2～4、L1～3节段标本10个，用自由落体撞击试验造成中间椎体爆裂型骨折，行APF椎弓根螺钉撑开复位，经椎弓根于伤椎椎体内置入可吸收高分子材料-DL-乳酸与ε-己内酯（70：30）的共聚物（PDLLA-CL）制作的可吸收球囊，注入自固化磷酸钙骨水泥行可吸收球囊椎体成形术。分别于骨折前、骨折撑开复位椎体成形术后，用万能材料试验机测定中间椎体在前屈、后伸、侧屈状态下应力-应变、轴向刚度变化及扭转应力下刚度的变化。[结果]伤椎经可吸收球囊椎体成形术治疗后，抗压强度均有所增加，前屈为8％，后伸15％，侧屈9．8％，其中以后伸时增加显著（P〈0．05）。治疗后的轴向刚度普遍得到提高，与骨折前相比，前屈增加11％，后伸增加8％，侧屈增加3％。治疗后椎体在扭转应力下刚度小于骨折前，但两者差异不明显（P〉0．05）。[结论]（1）结合短节段椎弓根螺钉系统撑开复位内固定的可吸收球囊椎体成形术，有助于伤椎的重建，术后脊柱的生物力学特性接近骨折前水平；（2）可吸收球囊椎体成形术治疗胸腰椎爆裂骨折，在避免骨水泥渗漏可能导致的潜在危险之前提下，从本质上恢复胸腰椎爆裂型骨折伤椎椎体结构的完整性，恢复其高度，从而恢复和维持脊柱的生理弧度，防止继发性脊柱后凸畸形变引起的迟发性腰背痛及脊髓、神经损伤，以从根本上解决单纯用经椎弓根内固定器治疗胸腰椎爆裂型骨折遗留的并发症，为临床治疗胸腰椎爆裂骨折提供了一个新的方法。     

EFFECTS OF LOCALLY ADMINISTERED ARGATROBAN ON RESTENOSIS AFTER BALLOON ANGIOPLASTY: EXPERIMENTAL AND CLINICAL STUDY

1. This study was undertaken to evaluate the preventive effects of locally administered argatroban, a competitive inhibitor of thrombin-induced platelet activation, on restenosis after balloon angioplasty. 2. A hydrogel-coated balloon catheter was immersed three times in argatroban/saline solution (1 mg/mL) for 60 s, inflated to a pressure of 606 kPa and left in the rabbit common carotid artery for 1 min. The same procedure was performed, without drug, as a control. The pharmacokinetics of delivered argatroban in the arterial wall were assessed using [¹⁴C]-argatroban. Platelet deposition 2h after balloon injury was quantified by fluorescence studies using antiplatelet antibody. Vascular smooth muscle cell (VSMC) proliferation 3 days after balloon injury was assessed by immunohistochemical staining for proliferative cell nuclear antigen (PCNA). In a clinical study, we divided 50 elective patients into two groups: argatroban and control. 3. In the experimental study, the mean quantities of argatroban at 0, 2 and 6 h after deflation wer. 24.63, 0.49 and 0.11 nmol/g wet weight of artery, respectively. Argatroban was undetected 24 h after deflation. Two hours after deflation, argatroban-treated arteries showed less platelet adhesion than saline-treated controls. The mean number of PCNA-positive cells was 16.9 and 43.8% in the argatroban and control groups, respectively (P < 0.01). In the clinical study, the mean late gain loss was 8.2 and 27.3% in the argatroban and control groups, respectively (P < 0.05). The mean late restenosis rate was 11.1 and 41.4% in the argatroban and control groups, respectively (P<0.05). 4. These data suggest that blood coagulation plays a significant role in VSMC proliferation after balloon injury and that locally administered argatroban using hydrogel-coated balloon catheter may prevent post-percutaneous transluminal coronary angioplast. restenosis.     

Design of a Centrifugal Blood Pump with Magnetic Suspension

Abstract: A new concept blood pump, whose impeller is suspended by permanent magnets and a mechanical pivot without seals or ball bearings, is presented in this paper. The primary aim of the blood pump is an application to implantable artificial hearts. The prototype model is of a centrifugal type with a four-vaned semiopen impeller 50 mm in diameter. Since this mechanism has no seals or ball bearings, flow stagnation or heat generation that might cause blood cell denaturation is expected to be small. The results of performance testing for the prototype model 2 were satisfactory regarding pump head and efficiency. The radial-suspension magnets and the magnetic coupling were stable. As a result, the present mechanism has been verified to be a candidate applicable to implantable artificial hearts.     

Clinical Evaluation of a New Type of Centrifugal Pump

Abstract: The major problems with existing centrifugal pumps are leakage, mechanical trauma, and thrombus formation. In consideration of these problems, a new compact centrifugal pump system was developed. The purpose of this study was to evaluate the new centrifugal pump system clinically. Ten patients underwent open heart surgery with a centrifugal pump or a roller pump. During surgery, hemodynamic and hematological data were obtained. A pulsatile assist device in the pump circuit was used in patients with severe heart disease. There was neither operative death nor hospital mortality, and there was no difference with regard to hemodynamic data between the two groups. The centrifugal pump group, however, had significantly lower hemolysis, especially during prolonged cardiopulmonary bypass. This centrifugal pump could also create sufficient pulsatile flow with a pulsatile assist device. Postoperative macroscopic and microscopic findings demonstrated the smooth surface of the pump without thrombus formation. This centrifugal pump system might be useful for prolonged cardiopulmonary bypass.     

ACARDIAC TWIN FETUS WITH SEVERE HYDROPS FETALIS AND BILATERAL TALIPES VARUS DEFORMITY

Twin reversed-arterial-perfusion syndrome (TRAPS) is a rare complication of monochorionic twin pregnancies. TRAPS is characterized by the hemodynamic dependence of a “recipient” twin from a “pump” twin. The “recipient” twin exhibits lethal abnormalities, such as acardia and acephaly. Circulatory failure of the normal twin derives from the existence of arterio-arterial and veno-venous anastomoses within the placenta that allow retrograde perfusion of the acardiac twin by blood coming from the normal twin. Acardiac twinning is the most extreme manifestation of the twin-twin transfusion syndrome. This occurs in 1 in 100 monozygotic twin pregnancies and 1 in 35,000 births. We report a case of diamnionic monochorionic female twins in which the acardiac twin demonstrated severe hydrops fetalis and bilateral talipes varus deformity. Cesarean section was performed on a 27-year-old hypertensive gravida 2, para 1 mother for fetal indications at 32 6/7 weeks gestation. The acardiac fetus had a two-vessel umbilical cord measuring 43.5 cm in length and 0.8 cm in diameter. The proximal end inserted into the root of the normal twin's umbilical cord in an acute angle forming a “v” close to the placental disc. Structures rostral to the thorax were absent except for a round mass of flesh with three small buds in place of the head and neck, and bilateral upper extremities. Only the kidneys, right adrenal, small and large intestine, and rudimentary urinary bladder were present. Both feet demonstrated talipes varus deformity. The fetus was severely hydropic. The subcutaneous fat measured 4.5 cm in maximum thickness. The normal twin had a protracted course complicated with respiratory distress syndrome, moderate secundum atrial septal defect with left to right shunt, and thrombocytopenia of prematurity. The baby was eventually discharged after approximately 1 month. At the time of this report, 5 months postpartum, the neonate is growing and developing normally. To our knowledge, this is the first report of severe hydrops fetalis and talipes varus deformity in an acardiac twin.     

Modification of the Na,K-pump of glial cells within cobalt-induced epileptogenic cortex of rat

The characteristics of a glial Na⁺,K⁺-pump dependent on extracellular K⁺ within epileptogenic cortex were studied electrophysiologically, biochemically and histochemically in vitro using slices from cobalt-induced epileptogenic cortex of rat. When the extracellular K⁺ concentration ([K⁺]_o) was varied between 4 and 40 mM, the mean slope of membrane potential plotted against [K⁺]_o was about 57 mV in glia from the normal cortex (tissue A) and about 44 mV in glia from the epileptogenic cortex (tissue B); whereas no significant difference in the resting membrane potential of these tissues was observed. In glia from tissue B, a marked transient hyperpolarization above control level was caused by replacement of elevated [K⁺]_o with the normal medium. Ouabain abolished these phenomena observed in glia from tissue B, but had no effect on the membrane potential during normal [K⁺]_o. Reduction of extracellular Na⁺, Ca²⁺ and Cl⁻ did not significantly affect the membrane potential of glia from either tissue. In tissue A, the cells marked by intracellular injection of horseradish peroxidase after intracellular recording were protoplasmic astrocytes; in tissue B, fibrous astrocytes with abnormal processes predominated. K⁺-dependent stimulation of Na⁺,K⁺-ATPase activity of the astrocyte-enriched fraction and its membrane preparation from tissue B was much larger than that from tissue A. A certain amount of the reaction product of K⁺-pNPPase activity was seen on glial plasma membrane within tissue B but not on that from tissue A. The above findings suggest that a glial Na⁺,K⁺-pump within actively firing epileptogenic cortex may be modified to increase in its activity.     

非体外循环冠状动脉搭桥术早期疗效的探讨

目的：探讨非体外循环心脏不停跳冠状动脉搭桥术的安全性和早期临床效果。方法：自2000年7月至2002年3月51例冠心病患接受冠状动脉搭桥手术，按手术方式分为非体外循环组（n=21）和传统体外循环组（n=30)。将两组病人的术前临床资料，手术方式，术后并发症和疗效等进行对比分析。结果：两组术前临床资料无明显差异。非体外循环组手术时间，术后出血输血量，呼吸机辅助时间显少于体外循环组，并且术后心律失常的发生率明显降低（P均＜0．05），其他重要器官的并发症发生率亦低于体外循环组。两组平均随访9．6个月，心绞痛均消失，心功能改善，活动量明显增加。结论：非体外循环冠状动脉搭桥术是安全可行的，并发症少，近期疗效满意。     

喂饲泵应用的临床观察及护理

目的 探讨用喂饲泵行肠内营养摄入的临床应用价值。方法 实验组30例采用喂饲泵控制肠内营养液的滴入速度，对照组采用传统方法，用20ml或50ml注射器灌注营养液，观察两组并发症的发生情况，所得量化指标进行卡方检验。结果实验组其返流、呕吐、腹胀、吸入性肺炎的发生率明显低于对照组。结论应用喂饲泵行肠内营养的摄入，可有效预防并发症的发生。