术中神经电生理监测在脊柱椎弓根螺钉置入中的应用进展

近年来,随着术中影像导航技术的提高,椎弓根螺钉固定技术在脊柱后路内固定准确性、安全性上得到了显著的提高.然而,术中的影像导航技术难以做到病变及其周围的功能性定位,术中进行椎弓根螺钉置入时仍然存在损伤神经的医源性损伤的危险,而且术中影像导航还可造成较大的射线损伤.近年来,术中神经电生理监测技术(intraoperative neuroplhysiollogical monitoring,IOM)应运而生,已经成为微创神经外科不可缺少的手段<'[1]>,同时为指导椎弓根螺钉置入手术的进程和提高手术的安全性上奠定了重要基础<'[2-7]>.     

脊柱椎弓根螺钉定位导向装置的研制与临床应用进展

随着椎弓根螺钉固定技术的发展,该技术已广泛应用于脊柱外科的多种脊柱疾病的手术治疗中.但由于椎弓根与其周围的脊髓、神经根、血管等组织关系密切,在术中置入椎弓根螺钉的过程中,若置入钉位置不当,有损伤脊髓、神经根和血管的可能,存在一定的风险.随着计算机辅助技术在脊柱外科的应用,椎弓根螺钉置入的准确性大大提高,但是大型的导航及术中监测设备价钱昂贵、操作繁琐、手术时间长、术中反复透视对医生和患者具有较大射线损伤等缺点.     

计算机辅助导航技术在脊柱侧凸手术中应用的初步经验

[目的]探讨计算机辅助导航技术在脊柱侧凸手术中的应用价值。[方法]自2006年2月起将计算机辅助导航技术应用于脊柱侧凸外科手术,进行相关的临床研究。分别采用计算机辅助导航技术行椎弓根螺钉植入及传统的解剖标志辨认法辅助X线定位进行椎弓根螺钉植入术,术后通过CT等影像学检查判断两组内固定术的植钉准确性。[结果]10例脊柱侧凸病例共植入椎弓根螺钉114枚。其中5例采用计算机辅助导航手术系统辅助下行椎弓根螺钉植入手术,共植入椎弓根螺钉61枚,其中优56枚（91.8%）,良5枚（8.2%）,无差的螺钉;另5例采用传统的解剖标志辨认法辅助术中X线定位进行椎弓根螺钉植入术,共植入椎弓根螺钉53枚,其中优30枚（56.6%）,良12枚（22.6%）,差11枚（20.8%）。[结论]应用计算机辅助导航技术行脊柱侧凸椎弓根螺钉植入准确性明显优于传统的解剖标志辨认法辅助术中X线定位法,计算机辅助导航技术能显著提高脊柱侧凸外科手术的安全性及矫正效果,对脊柱侧凸手术具有极高的应用价值。     

个体化导航模板在胸椎椎弓根螺钉置入中的初步临床应用

目的:通过临床应用评价个体化导航模板辅助胸椎椎弓根螺钉置入的准确性和安全性。方法:2008年7月～2009年9月,对11例需要行胸椎椎弓根螺钉置入手术的患者(青少年特发性脊柱侧凸7例,先天性脊柱侧凸2例,胸椎结核后凸畸形1例,多发性胸椎骨折1例)术前根据CT三维重建图像利用计算机辅助设计及快速成型技术设计制作46个胸椎个体化导航模板,术中应用个体化导航模板辅助在T2～T12置入椎弓根螺钉92枚,术后CT扫描评价螺钉位置,记录有无与螺钉置入相关的并发症。结果:通过个体化导航模板辅助置入的92枚胸椎椎弓根螺钉中,83枚完全在椎弓根内,9枚穿破椎弓根壁(其中椎弓根内侧壁穿破2枚、椎弓根外侧壁穿破7枚),其中5枚螺钉因椎弓根宽度小于4mm(3.0～3.8mm)而采用椎弓根旁固定方法(椎弓根螺钉轻度穿破椎弓根外侧壁经胸肋关节内侧进入椎体),椎弓根壁非故意穿破率为4.3%,置钉准确率为95.7%,所有穿破椎弓根壁的螺钉的穿出距离均小于2mm,螺钉位置可接受率为100%。无与螺钉置入有关的神经、血管、内脏损伤等并发症的发生。结论:个体化导航模板辅助胸椎椎弓根螺钉置入的置钉准确率高,安全、可行。     

超声导航与椎弓根螺钉置入

椎弓根螺钉置入术是脊柱外科最常用术式,术中易损伤椎体周围神经和大血管,现有导航技术存在一定不足。超声导航费用低廉、电离辐射低、能实时显像,在椎弓根螺钉置入建立钉道过程中具有引导手术的应用前景。近年来骨超声导航技术在传导参数和成像系统方面的研究有较大进展,增加了椎弓根螺钉置入术中应用超声导航的可行性。该文就超声导航在椎弓根螺钉置入术中的应用作一综述。     

术中三维导航引导下脊柱侧凸的椎弓根螺钉置入研究

[目的]探讨术中实施三维导航在脊柱侧凸病人椎弓根螺钉置入的应用价值.[方法] 38例脊柱侧凸病人行三维导航引导下椎弓根螺钉固定术,其中青少年特发性脊柱侧凸18例,老年退行性脊柱侧凸20例.手术中脊柱CT三维扫描后向导航系统输入患者信息资料,用导航棒按导航指引下在最佳位置、直径和长度立体、动态地置入椎弓根螺钉.[结果]三维导航引导下成功对38例脊柱侧凸病人共置入236枚椎弓根螺钉,复查X线片和CT,无螺钉松动和断裂,按分类法:A级227枚,B级7枚,C级2枚,D级0枚.术后侧凸平均26°(21°～118°),矫正率(61％);术后后凸平均14°(5°～29°),矫正率39％.38例平均随访18个月(12 ～25个月),术后无脊髓或神经根损伤.[结论]三维导航引导下的脊柱侧凸椎弓根钉置入方法精确可靠.     

数字化导航模板在颈椎椎弓根螺钉置入中的应用

目的 :评价个体化导航模板辅助颈椎椎弓根螺钉置入的准确性和安全性。方法 :2010年8月~2013年8月,对25例需要行颈椎椎弓根螺钉内固定的患者术前行64排螺旋CT连续扫描,计算机重建颈椎三维模型、设计颈椎椎弓根的最佳进钉通道,获取每个颈椎椎板的解剖形态,设计与颈椎椎板吻合的反向模板,并模拟螺钉的最佳进钉通道,形成单侧定位导向孔的导航模板。利用3D打印技术打印颈椎模型和导航模块,通过术前模拟置钉测量出每个椎弓根的螺钉通道长度及椎弓根宽度,术中采用导航模板辅助置入椎弓根螺钉,术后行CT扫描评价螺钉位置,记录有无与螺钉置入相关的并发症。结果:利用导航模板辅助置入颈椎椎弓根螺钉共164枚,其中152枚完全在椎弓根内,4枚螺钉穿破椎弓根内侧皮质,8枚螺钉穿破椎弓根外侧皮质,无椎弓根上方、下方穿破的螺钉,未发现与置钉相关的椎动脉、神经根和颈髓等损伤的症状。结论:个体化导航模板辅助颈椎椎弓根螺钉置入可以提高置钉的准确率,增加颈椎手术的安全性。     

快速成型个体化导航模板辅助胸椎椎弓根螺钉置入可行性研究

[目的]通过尸体标本实验的方法探讨个体化导航模板辅助胸椎椎弓根螺钉置入的准确性及可行性.[方法]对6具胸椎尸体标本进行CT扫描,根据CT扫描资料,利用逆向工程原理及快速成型技术设计制造出个体化导航模板,利用个体化导航模板在尸体标本上辅助置入胸椎椎弓根螺钉,所有螺钉的置入由同一位具有腰椎椎弓根螺钉置钉经验但无胸椎椎弓根螺钉置钉经验的骨科医师进行操作,随后采用大体解剖的方法肉眼观察置钉的准确性;并根据螺钉是否穿破椎弓根、穿出距离及穿破方向进行分级.[结果]共设计制作了72个个体化导航模板辅助置入胸椎椎弓根螺钉144枚,132枚(91.7%)螺钉完全在椎弓根内;12(8.3%)枚螺钉穿破椎弓根,其中2枚螺钉穿破椎弓根内侧壁(穿破距离分别为0.6、0.8 mm),10枚螺钉穿破椎弓根外侧壁(9枚螺钉穿出距离<2 mm,1枚螺钉穿出距离为2.5 mm);没有椎弓根上方、下方及椎体前方穿破的螺钉.所有穿破椎弓根壁的螺钉均在安全可接受的范围内.[结论]快速成型个体化导航模板辅助胸椎椎弓根螺钉置入准确率高,对术者无特别的经验要求,手术操作简单、安全,可避免术中放射性损伤,为胸椎椎弓根螺钉的置入提供了一种新的可行方法,尤其适用于初学者.     

触发肌电图监测技术及其在脊柱矫形内固定术中应用的研究进展

目前,椎弓根螺钉内固定技术已被广泛应用于各种脊柱手术中,椎弓根置钉不良会导致神经损伤和内固定失败等[1、2],据报道,因椎弓根螺钉置入不当引起的并发症发生率在1%～11%[3]。由Calancie等[4、5]提出的触发肌电图（triggered electromyograph,t-EMG）监测技术被认为是可以评估椎弓根螺钉置入准确性客观、有效的方法。脊柱侧凸畸形常伴有椎弓根变异、椎体旋转、主动脉位置变异、凹侧椎弓根贴近脊髓等特点,螺钉置入不当极易造成大动脉损伤、硬膜撕裂、神经根损伤,甚至损伤脊髓等[6～8],对椎弓根螺钉置入准确性的要求更高,此项技术在脊柱畸形矫正术中的应用意义更大。笔者就触发肌电图监测技术的原理、方法、临床应用及其研究进展综述如下。     

个体化导航模板辅助腰椎椎弓根螺钉置钉准确性实验研究

目的:探讨个体化导航模板辅助腰椎椎弓根螺钉置入的准确性.方法:根据10具尸体腰椎(L1～L4)标本术前CT资料,利用逆向工程原理及快速成型技术设计制造出个体化导航模板,在尸体标本上进行个体化导航模板辅助腰椎椎弓根螺钉的置入手术,术后行CT断层扫描评价螺钉在椎弓根及椎体内的位置.结果:共应用40个个体化导航模板,辅助置入腰椎椎弓根螺钉80枚.CT扫描发现所有螺钉进钉点准确,进钉方向适当:全部螺钉均准确置入相应椎弓根及椎体内,无穿破椎弓根皮质及椎体前方的螺钉.结论:个体化导航模板辅助腰椎椎弓根螺钉置钉准确性高,操作简单,为腰椎椎弓根螺钉的准确置入提供了一种新的可供选择的方法.     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.
Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.
Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r²=0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.
Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.     

缺氧对肾小管上皮细胞分泌外泌体的影响

目的    观察缺氧对肾小管上皮细胞分泌外泌体的影响,探讨外泌体在缺氧致肾脏损伤中的作用及机制。 方法    （1）常氧（21% O₂）及缺氧（1% O₂）分别处理大鼠肾小管上皮细胞（NRK-52E）48 h,收集细胞上清液并使用高速梯度离心法分离外泌体。采用透射电镜、纳米示踪分析、Western印迹、蛋白浓度定量鉴定并比较两组外泌体的基本特性。（2）在共培养实验中,以不同浓度（1、10、50、100、300 mg/L）的常氧外泌体、缺氧外泌体分别干预脂多糖（LPS）诱导的大鼠原代腹腔巨噬细胞,使用实时荧光定量PCR与酶联免疫吸附试验（ELISA）法分别检测巨噬细胞白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、诱导型氮氧化物合酶（iNOS）水平;使用Western印迹法检测巨噬细胞磷酸化（p）STAT/STAT及细胞因子信号传导抑制蛋白1（SOCS1）的蛋白表达;最后,使用实时荧光定量PCR法检测常氧外泌体与缺氧外泌体中炎性反应相关微RNA（microRNA,miR）的表达差异。 结果    （1）离心得到的囊泡具有外泌体典型的结构,粒径小于150 nm,表达外泌体标志蛋白CD63,说明分离得到外泌体。缺氧对肾小管上皮细胞分泌的外泌体形态、粒径分布比例无明显影响,但提高了外泌体的分泌量。（2）缺氧外泌体相比于常氧外泌体促进了LPS诱导的M1型巨噬细胞IL-6、TNF-α、iNOS 的表达和分泌（均P＜0.01）,同时提高STAT的磷酸化水平并减少SOCS1的蛋白表达（均P＜0.01）;对炎性反应相关microRNA检测发现缺氧外泌体中miR-155、miR-27a表达量较常氧外泌体明显升高（P＜0.05）。 结论    缺氧可改变外泌体的生物学功能,表现为协同促进LPS诱导的M1型巨噬细胞的表型转化,这可能是慢性肾脏病微炎性反应状态持续的原因之一。     

In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis

Abstract While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.