合并椎间盘突出的退变性腰椎滑脱椎间盘形态改变及其意义

【摘要】 目的：观察合并椎间盘突出的退变性腰椎滑脱（lumbar degenerative spondylo-listhesis,LDS）患者的椎间盘影像学特点,探讨椎间盘退变程度、椎间隙角度及高度与退变性腰椎滑脱间的关系。方法：以2009年10月～2011年11月我院和石景山医院收治的合并L4/5椎间盘突出的退变性腰椎滑脱患者37例作为观察组,另选同期单纯L4/5椎间盘突出症患者38例作为对照组,对L4/5椎间盘退变程度按照Pfirrmann法分级,CT测定L4/5椎间盘正中矢状面的椎间隙角度和椎间隙高度,对所得数据进行统计分析。结果：观察组L4/5椎间盘MRI退变程度B、C、D、E级分别为1、25、8及1例,对照组分别为2、21、13及2例,两组椎间盘退变程度间差异没有显著性（P>0.05）;CT测量L4/5椎间隙角度观察组和对照组分别为3.08°±1.87°和6.48°±2.92°,对照组椎间隙角度明显大于观察组（P<0.05）;椎间隙高度观察组和对照组分别为8.46±1.81mm和9.38±2.46mm,两组间比较差异没有显著性（P>0.05）。结论：椎间隙角度减小,可能是退变性腰椎滑脱发病的重要因素之一。     

下腰椎间盘退变与两侧髂骨连线高度的相关性研究报告

目的研究髂嵴联线高度与腰椎间盘损伤和退变的关系。方法根据两侧髂嵴最高点连线与腰椎正中线交点,将两侧髂嵴最高点连线与腰椎的关系分成四组,即连线在L4椎下缘以上者为A组、连线在L4-5椎间隙为B组、连线在L5椎体上缘以下至L5椎中1/2部分为C组、连线和L5椎中1/2以下者为D组。结果A组L3-4椎间盘突出最多,L5-S1则最少;D组L3-4椎间盘突出最少,L5-S1则最多,二组相比均有显著差异。结论两侧髂嵴联线高度是L3-4、L5-S1椎间盘损伤和退变的重要影响因素。     

不同程度椎间盘退变相应椎间孔的影像学变化及其临床意义

目的：从影像学角度研究腰椎间盘不同退变程度时相应椎间孔形态改变的规律,探讨其临床意义。方法：自2006年12月至2008年2月选取37例L4,5椎间盘呈退行性变化的影像学资料（MRI、CT）进行研究,男23例,女14例,年龄28～62岁,平均41.6岁;分别将其矢状位MRIT2WI成像,采用MRI机内Mean/Curve测量软件测量计算L4,5节段退变椎间盘信号强度与相应节段脑脊液平均信号强度比值（RSI）,判断椎间盘退变程度并进行分组。分为3组：轻度退变组11例（A组）,中度退变组13例（B组）,重度退变组13例（C组）。根据CT1.25mm薄层二维旁矢状位重建测量L4,5节段椎间孔的最大高度、最大宽度与面积。分析椎间盘在不同退变程度下相应椎间孔变化规律及可能对神经根状态的影响。结果：①中、轻度退变组椎间孔的最大高度及面积差异均无统计学意义（P〉0.05）,重、中度退变组椎间孔最大高度及面积均有统计学意义（P〈0.05）,重、轻度退变组椎间孔最大高度差异有统计学意义（P〈0.01）;②重、中、轻度退变组椎间孔最大宽度差异均无统计学意义（P〉0.05）。结论：随着腰椎间盘退变程度加重相应椎间孔的高度及面积也逐渐减小,而其对椎间孔宽度影响不大;椎间孔高度及面积变小有可能导致神经根受压。     

微创与开放经椎间孔腰椎间融合术后邻近节段退变的比较

目的研究两种手术方式治疗腰椎间盘突出伴不稳术后出现邻近节段退变的情况。方法将115例L4~5椎间盘突出伴不稳行腰椎后路椎间融合术患者根据手术方式分为经椎间孔腰椎间融合术(TLIF)组(开放组,53例)和微创经椎间孔腰椎间融合术(MIS-TLIF)组(微创组,62例)。手术前后评测邻近椎间盘Pfirrmann评分及椎间隙高度变化,术后通过Seo评分系统评估椎间小关节受损情况,应用疼痛VAS评分及ODI评分评估临床疗效,评估术后邻近椎间盘的退变情况。结果患者均获得随访,时间6~48个月。VAS评分及ODI评分:术后3 d微创组明显低于开放组,差异有统计学意义(P0.01);术后1年两组比较差异无统计学意义(P0.05)。术后多裂肌横截面积减少的程度及多裂肌脂肪化程度微创组明显小于开放组,差异有统计学意义(P0.01)。手术对腰椎椎间关节的损伤开放组明显高于微创组,差异有统计学意义(P0.05)。邻近节段退变的发生与多裂肌功能减退及小关节突退变具有相关性(P0.01)。结论 MIS-TLIF治疗腰椎间盘突出伴不稳较开放TLIF可以更好地保护椎旁肌及小关节突的完整性,且术后近期邻近节段退变的发生率低。     

双源CT连续动态扫描评价腰椎不同曲度对椎间孔和椎间盘的影响

目的采用双源CT连续动态扫描评价腰椎不同曲度对腰椎间盘突出症患者腰椎间盘突出与椎间孔变化的影响。方法选取自2013-10—2014-10确诊的L4、5椎间盘突出症40例。仰卧位0°的位置为运动过程中动态扫描时的0°位置,根据腰椎矢状面Cobb角测量方法测量运动过程中伸展10°、20°和屈曲10°、20°的图像。测量腰椎间盘突出距离和椎间孔面积。结果在过屈位到过伸位运动过程中,L4、5椎间盘后缘突出程度逐渐增加,从中立位向过屈位运动时L4、5节段椎间盘突出程度变化更加明显。腰椎屈曲运动过程中腰椎每屈曲10°椎间盘突出减少(0.87±0.26)mm;伸展运动过程中腰椎每伸展10°椎间盘突出增加(1.24±0.45)mm。腰椎运动过程中,腰椎每伸展10°其椎间孔面积比仰卧位静态扫描时减小(8.02±0.34)mm~2;腰椎屈曲10°时,90%的患者椎间孔面积比常规仰卧位扫描时减小(6.72±0.23)mm~2;屈曲20°时,82.5%的患者L4、5节段椎间孔面积比静态扫描增时大(7.02±0.15)mm2。结论腰椎双源CT连续动态扫描可以明确诊断常规CT扫描阴性而下肢症状典型和常规CT结果与临床症状差异较大的腰椎间盘突出症患者。     

经皮激光腰椎间盘减压术后腰椎关节突关节和椎间高度的变化

目的：观察经皮激光椎间盘减压术（percutaneous laser disc decompression，PLDD）治疗腰椎间盘突出症术后腰椎关节突关节和椎间高度的变化。方法：应用半导体激光系统对32例腰椎间盘突出症患者进行PLDD治疗。29例患者为单节段突出，其中L3/4 3例，L4／5 18例，L5/S1 8例；3例患者同时合并IA／5和L5/S1节段突出。利用Macnab标准评价随访患者的疗效，并观察术前、术后椎间盘突出节段关节突关节角的形态，测量L3，4、L4/5和L5／S1椎间高度指数和椎间盘突出节段关节突关节角的角度。结果：所有患者无术中和术后并发症。随访14～22个月，平均17个月，按Macnab标准评价：优14例（43．75％），良13例（40．63％）；可3例（9．37％），差2例（6．25％），优良率84．38％。术后L5/S1椎间高度指数与术前相比显著性下降（P〈0．05），但L3/4和L4／5椎间高度指数无显著性改变；关节突关节无明显退变；L4／5和L5／S1椎间盘突出侧的关节突关节角角度显著性下降（P〈0．05），但L3/4椎间盘突出侧的关节突关节角度无显著性改变。结论：经皮激光腰椎间盘减压术后患者的L5／S1椎间高度和腰椎间盘突出侧关节突关节角角度下降．有可能增加腰椎滑脱的风险。     

肥胖及骨密度与腰椎间盘退变程度的相关性研究

目的 分析不同体质量指数(body mass index,BMI)的腰椎间盘突出症患者骨密度(bone mineral density,BMD)、腰椎间盘退变程度差异,并探讨BMD与腰椎间盘退变程度的相关性.方法 回顾2017年1月～2020年1月因腰腿痛于本院脊柱骨科门诊就诊的137例腰椎间盘突出症患者临床资料.基于体质量指数,分为正常组(18.50.05);三组下腰椎椎体(L3、L4)BMD水平、下腰椎椎间盘(L3-4、L4-5)退变程度比较,差异有统计学意义(P<0.05),其中,肥胖组L3与L4 BMD水平、L3-4与L4-5段椎间盘退变程度均明显高于其他两组(P<0.05),超重组L3与L4 BMD水平、L3-4与L4-5段椎间盘退变程度明显高于正常组(P<0.05).Pearson相关性分析显示,L3 BMD水平与L3-4椎间盘退变程度呈负相关(r=-0.547,P<0.05);L4 BMD水平与L4-5椎间盘退变程度呈负相关(r=-0.741,P<0.05).结论 BMI与腰椎BMD、腰椎间盘退变程度存在关联;对于腰椎间盘突出症合并肥胖患者,更易发生下腰椎椎间盘退变,下腰椎椎体BMD与相邻椎间盘退变程度呈负相关,椎间盘退变程度随BMD水平升高有减缓趋势.     

巨大腰椎间盘突出症伴终板早期退变的非融合治疗

[目的]回顾性研究非融合技术(Wallis)治疗伴有Modie Ⅰ型改变的巨大腰椎间盘突出症的临床疗效及影像学结果,观察腰背痛缓解程度及终板变化情况.[方法]2008年1月～2008年8月,共治疗26例腰椎间盘突出症伴Modie Ⅰ型改变的患者,均为L4,5间隙.男10例,女16例;平均年龄38岁.所有病例均行椎间盛突出髓核摘除+Wallis动态固定术.患者术前、术后3个月及末次随访时摄腰椎正侧位及动力位X线片,分别测量椎间盘前、后缘高度,椎间孔高度,观察术前及末次随访手术节段MRI T2加权像终板变化,同时进行Oswestry功能障碍评分(ODI)、疼痛视觉模拟评分(VAS).术后平均随访24.2(20～29)个月.[结果]术后3个月及未次随访的ODI及VAS评分均较术前有明显下降(P<0.001),术后3个月时椎问盘后缘高度及椎间孔高度较术前明显增加(P<0.05),椎间盘前缘高度较术前略有增加(P>0.05),但末次随访时高度呈卜降趋势.获得随访的20例MRI表现仅有2例手术节段终板退变为Modic Ⅱ型.[结论]棘突间撑开装置Wallis作为一种颅防及治疗腰椎早期退变疾病的非融合技术,能有效缓解腰腿痛,一定程度上延缓病变节段椎间盘的退变,同时能较好的维持手术节段的椎间盘及椎间孔高度,远期疗效尚需长期的随访研究.     

下腰椎椎间孔形态与椎间盘高度丢失的相关性研究

目的描述下腰椎椎间孔的形态及椎间盘高度丢失时椎间孔形态的变化。方法取正常的成年新鲜尸体下腰椎标本8具(L3～S1),观察标本在不同状态(椎间盘完整和椎间盘破坏)及不同加载条件(0、300、500N)下L4,5 和L5S1椎间孔的形态及其和神经根的解剖关系,测量椎间孔的高度、最大宽度、最小宽度,于X线侧位片上测量椎间盘前、后高度。结果在未加载的自然状态下,椎间孔上大下小,呈倒置的泪滴形,神经根位于椎间孔上部。在椎间盘完整的状态下,加载500N时,椎间孔形态及其与神经根关系的变化不明显。摘除髓核,随着加载量逐渐增大,椎间孔逐渐缩小、变形,神经根被推挤向同位椎弓根的下缘;椎间孔高度、最大宽度和椎间盘前高、后高逐渐减小,与未加载时比较差异有显著性(P<0.05)。经多元线性回归分析,椎间孔高度与椎间盘后高、前高呈线性相关。结论椎间盘高度丢失与椎间孔形态改变关系密切,椎间孔形态改变增加了神经根卡压的危险性。     

腰椎关节突关节骨性关节炎对腰椎稳定性的影响

目的探讨腰椎退变过程中,腰椎间盘退变、关节突关节骨性关节炎与腰椎稳定性之间的关系.方法对78名腰椎退变患者进行腰椎MRI和动力位X线摄影.腰椎不稳分为椎间角度运动不稳、旋转不稳和椎间位移不稳,其中椎间位移不稳细分为前向不稳、后向不稳和前后向不稳.腰椎间盘退变依据矢状位T2加权像分为5级;关节突关节骨性关节炎依据水平位T1加权像分为4级.对资料进行统计分析.结果腰椎椎间角度运动不稳和前后向椎间位移不稳与关节突关节骨性关节炎存在显著负相关,前向椎间位移不稳与腰椎关节突关节骨性关节炎和椎间盘退变呈显著正相关,腰椎矢状面旋转不稳与腰椎关节突关节骨性关节炎无显著相关.结论腰椎间盘退变和腰椎关节突关节骨性关节炎可影响腰椎运动节段的稳定性.     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.