Experimental laparoscopic aortobifemoral bypass

The goal of the present study is to develop a technique for laparoscopic aortobifemoral bypass.Piglets weighing between 60 and 78 kg were anesthetized with halothane. The lateral retroperitoneal approach was preferred to the more familiar anterior transperitoneal approach and was successfully completed in 19 piglets. The piglets were placed in the right lateral decubitus position. The first port (2 cm) was inserted halfway between the tip of the 12th rib and the iliac crest. Four other trocars were placed in the retroperitoneum after balloon inflation had allowed creation of a space which permitted visualization of the aorta from the left renal artery down to the aorto-iliac junction. After evacuation of the retropneumoperitoneum, the cavity was maintained using an abdominal lift device and a retractor.Using this approach, we performed four aortobifemoral bypasses (end-to-end aortic anastomosis) after conventional intravenous heparinization (100 IU/kg) in less than 4 h. Blood loss did not exceed 250 ml and the hematocrit remained stable. Postmortem evaluation of the grafts revealed they were positioned as in a conventional bypass, their limbs having followed in the created retroperitoneal tunnels along the path of the native arteries. No mortality occurred before sacrifice of the animals. We believe that this first performed series of totally retroperitoneal laparoscopic aortobifemoral bypasses in the porcine model is useful in preparation for human application due to the anatomical similarities in the periaortic region.     

躯干运动和负重时对足底支撑面侧向横移的姿势控制

目的:本研究假设自主运动命令和姿势控制信号间有冲突,因此设计在附加重物和不同自主任务的同时给予足底一个模拟受滑的干扰(横移)来观察姿势变化并分析其是否受冲突命令或者力学参数的影响.方法:受试者在执行各种不同的自主任务时,随机给予足底支撑面一个左侧或右侧的横移干扰.这些不同的自主任务包括不负重静止站立、静止站立单手负重5kg、负重5kg站立并躯干静止侧屈15°、负重5kg动态地提重物和放重物5项任务.测量和分析下列参数:中心压力的侧位移(COP)、躯干和股部在冠状面上的角位移和腹内压(IAP).结果:干扰离开质量(向右)、始反应超射的幅度、达到终平衡的时间和达到平衡前COP位移的次数都增加,这种情况可以看作是为了再获得平衡的姿势反应效率降低,因此,如果质量的重力效果能对抗干扰,则再获得平衡的反应效率甚至可以被增进.结论:提重和负重是危害姿势反应效率的因素,因为提重和负重改变了重力效果,加大了对躯干的干扰.在动态条件下躯干的运动不是被横移干扰增强就是被横移干扰抵消,并没有显著地影响改变最终平衡位置姿势校正的效应.因此附加任务的同时给一个支持面上的横移干扰,姿势控制的效应可以被抵消.这个减低的效应可以引起脊柱周围结构的负荷增加和增加受伤的危险性.但是,在恰当地放置负重的位置时,反而可以增进躯干控制和协助恢复姿势平衡.     

Repetitive lifting and spinal shrinkage, effects of age and lifting technique

The assumed advantages of the so-called leg-lifting technique over the back-lifting technique are still the subject of much debate. The present study was aimed at studying the consequences of performing both lifting techniques on net lumbar moments and spinal shrinkage. Furthermore, the relation between age and spinal shrinkage was studied. Five subjects approximately 40 years old and six subjects 20 years old performed six 5-min bouts of repetitive lifting using each technique on a separate day. Net lumbar moments were calculated using a two-dimensional dynamic linked segment model. Spinal shrinkage was measured at T₁₂ and at the head after each bout of lifting and every 5 min during 1 h preceding the lifting bouts. The peak moments were marginally but significantly higher in the leg-lift. No differences in mean moments and shrinkage between lifting techniques were found. The shrinkage after the back-lift was more pronounced in the older subjects and a similar tendency was found after the leg-lift. The creep rate, i.e. the rate at which the shrinkage approaches its equilibrium was higher in the older subjects. No clear relations of anthropometrical variables and net moments with shrinkage was found. The common advice of using a leg-lift rather than a back-lift was not supported by the present study. Both the mechanical load on the low back (net moments) and the resulting shrinkage show considerable interindividual variation, the causes of which need further elucidation.

The leg-lifting technique is still widely advocated, thought its merits from a biomechanical point of view have been questioned. In this study spinal shrinkage and lumbar moments calculated by means of a dynamic linked segment model are used to compare the leg-lift to the more commonly used back-lift.     

Laparoscopic repair of a diaphragmatic hernia through the foramen of Morgagni

A 78-year-old woman is described who presented with a diaphragmatic hernia through the foramen of Morgagni. A definitive diagnosis was confirmed by a sagittal view on magnetic resonance imaging prior to surgery. The hernia was repaired laparoscopically under an abdominal wall lifting technique without pneumoperitoneum, and her symptoms completely resolved postoperatively with no evidence of recurrence. The laparoscopic repair was considered a suitable and safe procedure for the treatment of a Morgagni hernia. Received: 3 April 1996/Accepted: 3 May 1996     

外侧眉下垂的解剖力学研究

目的:探讨外侧眉下垂与该区肌肉力学的关系,为眶周年轻化手术提供更加详实的解剖依据。方法:对10%福尔马林固定的成人尸头33侧进行大体和显微解剖观察。结果:下垂眉形组的额肌宽度在内眦间连线头侧3.0cm水平为(53.04±3.85)mm,5.0cm水平为(59.71±3.82)mm,明显窄于非下垂眉形组相应水平的(56.14±4.29)mm和(63.23±5.40)m(mP<0.05)。下垂眉形组眼轮匝肌外侧束出现率为87.5%,明显大于非下垂组的52.9%(P<0.01)。结论:外侧眉缺少额肌的支持及眼轮匝肌外侧束的出现是外侧眉下垂的重要原因之一。     

Low-pressure Pneumoperitoneum for Laparoscopic Surgery Using a Disposable,Flexible Abdominal Wall Retractor

Abstract: Since April 1991, we have studied 160 patients who had had a successful laparoscopic cholecystectomy. Nine patients who presented with chronic cholecystitis with severe local adhesion and who were also considered to require a longer operative time were selected as suitable candidates for this procedure. They were successfully treated under a zero- to four-mmHg low-pressured pneumoperitoneum procedure combined with total abdominal wall lifting using a disposable, flexible vinyl tube retractor. This method enabled exactly the same clear laparoscopic vision as is possible in the routinely-used high-pressure pneumoperitoneum even in the marginal portions of the abdominal cavity. Moreover, it facilitated early reinsufflation after the cauterization-produced smoke was exhausted, which minimized the operative time and reduced the surgeon's anxiety concerning the maintenance of a sufficiently airtight condition. We believe that this low-pressure pneumopeqitoneum procedure also benefits the poor-risk patient who has restricted cardiopulmonary function, especially during advanced laparoscopic surgery which requires a longer operative and anesthetic time.     

自适应提升小波用于心电信号除噪

人体心电信号随着检测状态及时间的变化显示出明显的非平稳性并伴随着大量的干扰信号.提升小波能很好的对心电信号进行时频定位,并且其运算速度比传统小波高出许多.本研究以提升小波变换为基础,构造了一种基于尺度的自适应提升小波,用它对心电信号（ECG）进行分解,使不同频带的信号显示在小波分解的不同尺度上,并在信号重构时利用一种新的阈值方法去除不同尺度上的干扰信号,从而获得较精确的心电波形,为心电信号的进一步处理奠定了基础.     

眉部运动的显微外科解剖学研究及其临床意义

目的：为解决除皱术中眉毛上提效果欠佳,不够持久的问题。方法：对10例新鲜尸体进行了大体及显微解剖。结果：证实了额肌深面“滑动层”和“滑动间隙”的存在,观察了眉内侧2／3自皮肤向深面发出固定到眉嵴处的眉毛支持韧带,外侧上方的颞融合线和下方的眉限制韧带静态固定结构,上述结构决定了眉毛的形态;阐述了额肌、皱眉肌和降眉肌的眉毛动力机制,探讨了老年性外侧眉毛下垂主要由于外侧的滑动脂肪垫向下“疝出”所致。结论：通过破坏“滑动间隙”,切断颞融合线和眉限制韧带,切除外侧滑动脂肪垫,达到眉部上提的良好、持久效果。