生物相容高分子水凝胶在椎间盘修复再生方面作用的研究进展

椎间盘退行性变为慢性疾病,会导致脊柱承重不稳,进而损伤脊髓、马尾神经和神经根,60%的70岁以上老年人群会发病^[1-2]。由于椎间盘退行性变的病理学、病理生理学及生物力学机制并不完全清楚,目前的治疗手段仅能减轻疼痛症状,不能完全消除疾病^[3-4]。椎间盘切除术和椎间融合术是治疗椎间盘退行性变的常用术式,但易造成脊柱生物力学的改变^[5]。人工椎间盘可应用于椎间盘退行性变的治疗,但因椎间盘的结构和功能复杂,很难设计出理想的椎间盘假体来保持天然组织结构和生物力学特征。理想的生物组织替代物应具有高强度、高柔性和高韧性^[6]。     

多裂肌萎缩与腰椎退行性疾病的相关性研究进展

腰椎退行性疾病是脊柱外科常见病和多发病,是引起下腰痛的主要原因^［1］,下腰痛是以腰骶、臀部伴/不伴下肢疼痛为主要症状的综合征^［2］。有研究^［3-4］发现,下腰痛的发生、发展与脊柱稳定性的失衡密切相关。椎旁肌是脊柱邻近肌群的总称,分为前群（髂腰肌、腰方肌、腰大肌）和后群（多裂肌、竖脊肌等）。椎旁肌良好的功能状态对脊柱稳定性起着重要作用。多裂肌作为腰椎稳定性的重要来源,其萎缩与腰椎椎间盘突出症、腰椎椎管狭窄症、腰椎滑脱症等腰椎退行性疾病关系密切^［5-6］。本文通过查阅多裂肌萎缩与腰椎退行性疾病的相关文献,对多裂肌萎缩的影像学变化、多裂肌萎缩与腰椎退行性疾病的关系及多裂肌的保护与治疗等方面进行分析梳理,综述如下。     

选择性神经根阻滞的价值和争议

选择性神经根阻滞（SNRB）是指对患有脊柱退行性疾病的患者，经查体后在影像学技术（X线，CT和B超）的辅助引导下，对高度怀疑病变的神经根（颈、胸、腰、骶）进行选择性地穿刺、定位、阻滞、治疗的一种微创技术^［1-2］。随着微创精准医疗理念的不断发展，SNRB的临床应用越来越广泛，可定位诊断和治疗病变神经根。当SNRB作为诊断方法时，强调定位的精准性，操作要求神经根定位明确，药物阻滞精准，尽量减小阻滞范围，降低假阳性的发生率。随着微创手术技术的广泛开展，多节段脊柱退行性疾病中责任神经根的术前精准定位至关重要，SNRB在明确责任节段、减少手术节段、预测术后效果方面具有重要意义^［3-5］。当SNRB作为治疗方法时，强调治疗的有效性，操作要求在降低并发症的同时，尽量增加SNRB的效果和持续时间。作为一种简单有效的脊髓硬膜外注射方法，SNRB广泛应用于颈肩腰腿痛的治疗，并取得了良好效果^［6-7］。     

Quadrant系统下单侧内固定治疗老年腰椎退行性疾病

腰椎退行性疾病是引起腰腿痛的常见原因,在老年人群中发生率超过50%^[1]。腰椎融合术是治疗腰椎退行性疾病的有效方法,可稳定椎体、恢复椎间高度,临床疗效良好^[2-3]。目前椎间融合术的金标准是双侧椎弓根内固定术,可为椎体间接提供坚固内固定,但坚固内固定会导致邻近节段退行性变及骨量丢失^[4]。有研究报道,单侧和双侧内固定治疗腰椎退行性疾病的临床疗效无显著差异^[5]。本院2016年6月—2018年1月采用Quadrant系统下单侧内固定治疗老年腰椎退行性疾病患者33例,疗效满意,现报告如下。     

动态稳定系统的生物力学和临床应用进展

动态稳定系统（Dynesys）由Stoll等^[1]在Graf韧带系统的基础上改进设计而成,现已广泛应用于治疗腰椎退行性疾病（LDD）。LDD主要包括腰椎椎间盘突出、继发性腰椎椎管狭窄、退行性椎体滑脱及退行性脊柱侧凸等,当引发严重腰腿部疼痛、神经根压迫等临床症状时往往需要手术治疗。与传统后路腰椎椎间融合术（PLIF）及经椎间孔腰椎椎间融合术（TLIF）相比,Dynesys通过椎弓根螺钉连接产生的动态推拉关系在固定节段对抗异常折弯力和剪切力、改善固定节段应力传导的同时保留固定节段活动度（ROM）,进而减少术后邻近节段退行性变（ASD）的发生^[2]。然而,目前关于Dynesys的临床疗效尚存在争议。本文对近年来国内外关于Dynesys的相关研究进行分析,从生物力学、临床应用等方面作如下综述。     

经皮内窥镜下手术治疗气性囊泡压迫所致腰椎神经根病1例报告

腰椎神经根病病因较多,常见的有腰椎椎间盘突出、椎管狭窄、滑脱等。近年来,随着MRI检查的普及,一些少见病因如黄韧带囊肿、关节突囊肿、黄韧带下血肿、海绵状血管瘤等相继以个案的形式被报道^［1-5］。而由气性囊泡压迫引起的腰椎神经根病并采用手术治疗的病例较少见。泰州市人民医院于2019年12月17日收治1例因气性囊泡压迫引起腰椎神经根病的病例,现将诊疗过程报告如下。     

经皮内窥镜技术治疗老年单节段退行性腰椎椎管狭窄症

腰椎椎管狭窄症（LSS）是骨科常见病之一。随着我国老龄化的加速,老年退行性腰椎椎管狭窄症（DLSS）的发生率逐年增加,腰腿痛和间歇性跛行严重影响患者的生活质量^[1]。DLSS往往由椎间盘突出或合并钙化、小关节骨赘增生及黄韧带肥厚等原因引起,部分患者合并发育性椎管狭窄^[2-3]。临床上根据解剖部位将LSS分为中央管狭窄（椎管中央型狭窄）、关节下管狭窄（神经根管的关节下段,包括侧隐窝）和椎间管狭窄（椎弓根及椎间孔段）^[4-5]。老年DLSS患者一般病史较长,影像学资料提示多节段的椎间盘膨出或突出、黄韧带肥厚、小关节增生、侧隐窝狭窄,有时神经根病变的定位诊断也不明确,是否需要将所有狭窄的间隙部位减压,是否需要广泛的融合固定一直是临床争论的问题^[6]。传统腰椎减压融合术治疗DLSS效果明显,但手术创伤较大,术后感染、切口愈合不良、植骨区不融合、内固定松动断裂、邻椎病等手术并发症使得此类技术的应用受到限制^[7]。近年来,经皮内窥镜技术在治疗DLSS方面优势明显,通过术前病史询问、体格检查及相关影像学资料的反复研究,并根据病情需要可结合椎间盘造影,最终精准定位责任椎间隙及椎管狭窄部位行靶向穿刺,达到定点精准减压。2014年5月-2017年8月,本院采用经皮内窥镜下减压术并射频消融术治疗老年单节段DLSS患者40例,现将诊疗过程报告如下。     

单侧双通道内窥镜下椎间盘切除术治疗腰椎术后退行性变1例报告

腰椎术后邻近节段退行性变(ASD)是腰椎后路融合术后的常见远期并发症^[1-2],其发生率为4%~31%^[3-5]。ASD由多种因素引起,继而产生新的神经压迫症状。Kambin等^[6]于1986年提出单侧双通道内窥镜下椎间盘切除术(UBED)治疗腰椎椎间盘突出症(LDH)^[7],其兼具了开放手术与微创手术的优点^[8]。本院采用UBED治疗腰椎术后ASD患者1例,现将诊疗过程报告如下。     

自噬对椎间盘退行性变作用机制的研究进展

椎间盘退行性变（IDD）被公认为是腰痛的主要原因,约有80%的人会在其一生中遭遇到腰痛^［1］。目前,世界上约有6.5亿人受到腰痛的困扰,仅在美国,每年投入的相关费用就超过了300亿美元,甚至超过了中风、呼吸道感染、糖尿病、冠状动脉疾病及类风湿疾病的费用总和^［2］。腰痛已是导致患者住院治疗的第二大常见病因,也是导致患者长期残疾的主要原因之一^［3］。此外,IDD还是颈部和背部疼痛综合征的主要原因,严重情况下甚至会造成患者残疾^［4］。随着人口老龄化的日渐加重,IDD对人类健康造成巨大危害,也给患者家庭和社会增加了沉重的经济负担。作为一种常见的复杂退行性疾病,其传统治疗措施已无法满足目前的临床需求。自噬细胞保护效应引起学者们的关注。椎间盘髓核细胞通过自噬适应外界环境,维持细胞稳态。适度激活自噬能有效抑制椎间盘细胞凋亡,延缓细胞外基质（ECM）降解。研究自噬在IDD中的作用机制,针对性地干预其病理生理进程,可为IDD的临床治疗提供新的理念。本文通过查阅近年自噬对IDD作用的相关文献,从IDD及自噬的发生机制、髓核细胞凋亡途径及自噬对髓核细胞凋亡的作用机制等方面展开分析,综述如下。     

混合现实技术引导的经皮内窥镜下腰椎椎间盘切除术的初步探索与应用

经皮内窥镜下腰椎椎间盘切除术（PELD）已经成为治疗腰椎椎间盘突出症（LDH）的首选方法^［1-3］。腰椎椎间盘突出类型多样化,术前须精确定位突出椎间盘的“靶点”位置,确定进针点、深度和角度等相关参数,以便术中可按照术前设计快速准确地穿刺和置入工作通道,这是靶向穿刺技术的核心,也是尽可能减少不必要创伤并发症的基础^［4］。常规手术通道的建立,需要根据椎间盘突出的不同病理类型并结合临床实践确定,且术中需要C形臂X线机透视辅助,存在学习曲线陡峭、辐射量大、手术风险高等问题^［5-6］。混合现实（MR）技术是近年发展起来的一门新兴技术,其将虚拟现实（VR）技术与增强现实（AR）技术相结合,操作者可从MR技术呈现的全息影像中获取相关信息,从而实现虚拟和真实的交互^［7-8］。目前,MR技术在复杂的脑外科手术、髋关节手术中已有应用,并获得良好的临床疗效^［9-11］,但尚无其应用于PELD的报道。本研究组在MR技术引导下,对1例LDH患者行PELD,取得了良好的临床疗效,现报告如下。     

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.     

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.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

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.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.