下腰椎前方三维CT血管造影重建及其意义

目的:观察下腰椎前方血管走行特点,为下腰椎前路椎间融合术,特别是腹腔镜下微创手术提供解剖学依据.方法:对60例(男女各30例)患下腰椎疾病需行前路手术治疗的患者行下腰椎三维CT血管造影(3D-CTA),观察下腰椎前方血管在椎体前的走行,测量与腰椎前方血管位置相关的解剖学参数.结果:三维CT重建图像发现腹主动脉分叉点变异较多,髂总静脉汇合点相对恒定;腹主动脉分叉点到L5椎体下缘的距离男性平均39.1mm,女性平均37.4mm;髂总静脉汇合点到L5椎体下缘的距离男性平均27.1mm,女性平均25.9mm;L5/S1椎间隙手术窗大小男性平均36.7mm,女性平均34.6mm;腹主动脉分叉角男性平均56.3°,女性平均58.9°;髂总静脉汇合角男性平均63.1°,女性平均65.7°;右髂总动脉与左髂总静脉夹角男性平均53.6°,女性平均57.3°.结论:下腰椎前方血管解剖位置具有多变性,以腹主动脉分叉点为甚,术前行腰椎3D-CTA检查能明确血管解剖,为手术尤其是腹腔镜下微创手术提供安全保障.     

下腰椎前路腹腔镜椎体间融合术的血管应用解剖

目的 对下腰椎(L3-S1)前路血管进行解剖学研究，分析其变异情况并探讨下腰椎前路腹腔镜下椎体间融合术的可靠性和安全性。方法 解剖30例成人尸体标本(男15例、女15例)，记录腹主动脉的分叉点及髂总静脉的汇合点位置，以及动静脉血管的椎前走向；测量上述分叉点与汇合点到L5椎体下缘的距离；测量L5／S1椎间隙手术窗大小(即平椎间隙右髂总动脉与左髂总静脉之间的距离)；记录骶正中动脉的起始点，骶正中静脉汇入点及二者的走向。结果 腹主动脉分叉点、髂总静脉汇合点分布在L4-L5之间，腹主动脉行走于椎体左前方，下腔静脉行走于椎体右前方；腹主动脉分叉点到L5椎体下缘距离，男性平均3．5cm，女性平均3．6cm；髂总静脉汇合点到L5椎体下缘距离，男性平均2．2cm，女性平均2．4cm；L5／S1椎间隙手术窗大小，男性3．7cm，女性平均3．4cm；骶中动脉均起源于腹主动脉分叉部后壁，在骶前沿中线左或右侧下行，骶中静脉多与之伴行。结论 腹主动脉分叉点与髂总静脉汇合点均高于L5椎体下缘，L5／S1椎间隙手术窗大小男性平均3．7cm、女性平均3．4cm，腹腔镜下前路L5／S1椎间隙融合术是可靠及安全的；由于血管的遮盖，L3，4、L4，5，椎间隙经腹膜前路融合术没有足够的血管分离及牵开是无法进行的。     

腹腔镜下腰椎前路手术入路的解剖学实验研究

目的:探讨腹腔镜下腰椎手术的可行性及腰椎不同节段安全有效的腹腔镜手术入路。方法:解剖30例成人尸体标本(男15例、女15例),记录腰椎前主要毗邻血管的解剖学参数;取家猪40只,均分为两组,采用腹腔镜下经腹膜后入路和经腹膜腔入路显露L2~S1椎体和椎间盘,比较两种入路的有效性、安全性。结果:尸体解剖发现腹主动脉分叉点变异较多,髂总静脉汇合点相对恒定;腹主动脉分叉角度男性平均54.9°,女性平均59.0°,髂总静脉汇合角度男性平均61.4°,女性平均64.9°;腹主动脉分叉点到L5椎体下缘距离男性平均3.5cm,女性平均3.6cm;髂总静脉汇合点到L5椎体下缘距离男性平均2.2cm,女性平均2.4cm;L5/S1椎间隙手术窗大小男性平均3.7cm,女性平均3.4cm。动物实验研究发现经腹腔显露L6/S1满意,而经腹膜后显露L2~L5满意。结论:应用腹腔镜技术进行腰椎手术是可行的,该技术具有重复性好,对组织损伤小,术野内解剖结构清晰,手术的安全性和有效性较高。显露下位腰骶椎以经腹腔入路为宜,而显露上位腰椎以经腹膜后间隙入路为宜。     

应用腹腔镜行下腰椎手术的解剖学研究

目的 观察研究下腰椎前方、侧方毗邻的血管结构的位置及走行,并测量各节段手术空间的大小,为腹腔镜下行腰椎手术提供安全区的解剖学依据.方法 解剖15例成人尸体标本(男9例,女6例),记录腰椎前方和侧方毗邻的主要血管解剖学参数,并测量出相应的结果.结果 腹主动脉分叉点变异较多,髂总静脉汇合点相对恒定,腹主动脉分叉点、髂总静脉...     

国人下腰椎前方血管解剖结构特点和入路分型

目的研究国人下腰椎前方血管与椎间隙之间的解剖特点，并进行解剖结构分型，为下腰椎前路椎间融合手术入路，尤其是腹腔镜下手术入路的选择提供解剖学依据。方法随机抽取94例国人腰椎MRI片，观察腰3-4、腰4-5，腰5-骶1椎间隙横断面前方的大血管解剖结构，判断腹主动脉的分叉位置和左髂总静脉与下腔静脉汇合位置，并进行解剖结构分型。结果根据腹主动脉分叉、左髂总静脉与下腔静脉汇合点与腰。椎间隙的上边缘之间的关系，确定4种类型。21例(22.3％)被归为A类(低分叉／低汇合)，34例(36．2％)被归为B类(高分叉／高汇合)，38例(40．4％)被归为C类(高分叉／低汇合)，1例(1．1％)被归为D类(低分叉／高汇合)。在腰5-骶1间隙腹主动脉均已分叉，左髂总静脉均未汇合。男女之间无显著性差异。结论下腰椎前方血管解剖位置具有多变性，以腰4-5椎间隙为著，使腹腔镜下手术入路变的复杂。术前常规腰椎。MRI图像能用来进行血管解剖位置的分类，并设计最佳的手术入路。     

下腰椎极外侧椎体间融合术的应用解剖

目的：观测腰椎侧方血管和神经的解剖分布，为下腰椎极外侧椎体间融合术（extreme lateral intervertebra fusion，XLIF）提供解剖学依据。方法：解剖30具成人尸体的腰椎侧方血管和神经，观察腰动、静脉的位置及走行；测量椎间孔外口处L3～L5脊神经距相邻下位椎间盘、腹主动脉后缘（左侧手术窗）和下腔静脉后缘（右侧手术窗）的距离。结果：L1、L2、L3节段血管走行、分布比较恒定，走行于相应椎体的中央偏下水平；但L4动、静脉走行变异较大，其中36．7％（11例）走行于L4／5间隙表面；L3～L5椎间孔外口处脊神经距下位椎间盘的距离逐渐增大；L3～L5左、右侧手术窗均逐渐增大．且同一节段左侧手术窗大于右侧。结论：XLIF在L3／4、L4／5间隙可以顺利进行。     

腰椎前路手术相关自主神经的解剖及临床意义

目的 对腰椎前方的自主神经进行解剖和组织学观察,提出避免导致逆行射精的自主神经丛损伤的腰椎前路手术途径.方法 选择10具防腐固定成年男性腰段标本,借助解剖放大镜和手术显微镜观察后腹膜与主动脉、髂总动脉及腰骶岬部前方筋膜的层次关系,自主神经丛的走行及上腹下丛(superior hypogastric plexus,SHP)在L5～S1椎前的分布.对主动脉前、主动脉旁和腰骶椎前组织行HE染色,观察腹膜后组织中自主神经的分布特点.结果 SHP一般通过腹主动脉分叉点左侧跨越左髂总动脉.SHP主干位于左、右髂总动脉形成的三角内,其最宽处位于腰骶间隙前7例(70%),位于骶前3例(30%);其中4例(40%)位于骶岬部左侧,6例(60%)位于腰骶岬部中线偏左.自主神经丛位于一层连续的独立于腹膜后的筋膜层中,且组织学观察进一步证实了自主神经筋膜层的存在.结论 经腹膜入路腰椎前路手术应从右侧切开后腹膜,分离时应轻柔地将SHP自右向左沿椎间盘边缘推开;选择外科平面要保证在神经筋膜层下进行分离,可以将位于腹主动脉和腰骶岬部的自主神经层整层掀起,达到保留自主神经的目的.     

体位改变对腰椎前斜入路通道影响的影像学分析

目的:探讨体位变化对L1~L5腰椎前斜入路椎间融合术(oblique lateral interbody fusion,OLIF)通道大小的影响。方法:随机选取40例健康志愿者,分别在仰卧位及右侧卧位进行L1~L5 MRI扫描。在位于椎间盘中点的图像内定义椎间盘中心点为O;A(平卧位)/A′(右侧卧位)点以及B(平卧位)/B′(右侧卧位)点为∠AOB(∠A′OB′)达到最小值时主动脉(或髂血管)左侧壁以及腰大肌前内侧壁上的点,记录各节段AB及A′B′的距离,并在各节段将AB与A′B′比较;将L1~L5各节段的A′B′进行节段间比较,并探讨其与性别、体重指数(body mass index,BMI)及腰大肌截面积(relative psoas cross-sectional area,PCSA)之间的关系。结果 :40例志愿者的BMI值为18.4~26.5,6例存在主动脉高分叉现象;各节段AB和A′B′(mm):L1/2为14.80±3.89和12.37±3.62,L2/3为12.85±4.16和9.96±3.37,L3/4为12.24±4.10和10.85±3.30,L4/5为9.78±4.69和9.72±4.37;主动脉高分叉者L4/5为7.72±3.56和6.71±2.86。在L1/2、L2/3、L3/4节段A′B′值显著小于AB(P=0.005,0.003,0.020);L4/5节段无论是否存在主动脉高分叉现象均无统计学差异(P=0.946,0.097);不同节段间A′B′值存在显著差异(P=0.046),通道大小趋势为L1/2L3/4L2/3L4/5主动脉高分叉者L4/5(其中L1/2显著主动脉高分叉者L4/5,P=0.003);男女性间A′B′在各节段无统计学差异(P均0.05);BMI与PCSA在L3/4与A′B′呈负线性相关(P=0.015,0.000),而PCSA在L1/2也与A′B′呈负线性相关(P=0.024)。结论 :右侧卧位时,OLIF通道解剖空间在L1/2、L2/3、L3/4水平显著减少,平卧位MRI对通道空间评估价值有限;而且OLIF通道大小与腰椎节段水平有关,并且受BMI值和腰大肌横截面积影响。     

腰椎椎旁大血管走行及其与腰椎位置关系的CT观测

【摘要】 目的：观察腰椎椎旁大血管走行情况及其与腰椎的位置关系,为腰椎后路手术提供指导。方法：选取50例在我院行腹部CT增强扫描患者的影像资料,其中男性34例,平均年龄53岁,平均身高174cm,平均体重68kg;女性16例,平均年龄54岁,平均身高167cm,平均体重63kg。采用PACS 11.0软件系统分别测量L1/2～L5/S1椎间盘水平椎旁大血管（腹主动脉、下腔静脉、髂动静脉及其分支）与椎体前、后面的相对位置关系,及其与椎体前、后面之间的距离。结果：男性椎旁动脉距椎体前、后面的距离分别为35.86±7.84mm、46.48±8.51mm;女性分别为32.15±6.03mm、41.57±6.72mm;男性椎旁动脉位于椎体前、后面的范围分别为10.87°±27.54°、7.61°±19.12°;女性分别为15.16°±31.85°、10.87°±22.48°;男性椎旁静脉距椎体前、后面的距离分别为35.86±7.84mm、46.48±8.51mm;女性分别为32.15±6.03mm、41.57±6.72mm;男性椎旁静脉位于椎体前、后面的范围分别为10.87°±27.54°、7.61°±19.12°;女性分别为15.16°±31.85°、10.87°±22.48°。男性椎旁动静脉距椎体前面和后面的距离均大于女性,差异均有显著性（P＜0.05）,而椎旁动静脉与椎体前、后面的相对位置关系男女之间无显著性差异（P>0.05）。腹主动脉分叉位置12例（24%）在L4椎体下半部,32例（64%）在L4/5椎间隙;髂总动脉分叉位置29例（58%）在L5/S1椎间隙,12例（24%）在S1椎体的上半部;髂总静脉汇合位置42例（84%）在L5椎体上半部;髂内外静脉汇合位置16例（33%）在L5/S1椎间隙,27例（53%）在L5椎体的下半部。结论：腰椎椎旁血管的分叉位置变异较大,女性椎旁动静脉距椎体前、后面距离更小,腰椎后路手术中咬除腰椎间盘时应该注意把握腰椎与椎旁血管的角度与距离,谨防误伤椎旁血管。     

下腰椎前血管的断层解剖学研究及其临床意义

经腹膜腰椎微创手术导致血管损伤，尤其是左髂总静脉和髂总静脉汇合点（conflunce of the common iliac veins，CCIV）损伤，是目前经腹膜腰椎微创手术最多，也是最严重的并发症。微创手术器械进入下腰椎受到腹主动脉分权点（aortic bifurcation，AoB）和CCIV的限制，它们在解剖上的变异增加了手术的风险性。[第一段]     

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.