聚丙烯酰胺水凝胶面部注射术后MRI分析

目的：探讨聚丙烯酰胺水凝胶（PAHG）面部注射术后MRI信号特征和常见并发症的MRI表现。方法：总结28例PAHG面部注射术患者的临床和MRI资料，并对其进行对照分析。结果：PAHG因其停留的解剖间隙不同，形态各异，T1WI为低信号，T2WI、T2WI抑脂为高信号，T2WI抑脂显示效果最佳。28例患者中12例发生水凝胶移位，3例硬结，3例不对称畸形。结论：MRI可对PAHG面部注射术后常见并发症提供诊断信息，是诊断PAHG面部注射术后并发症的理想检查方式。     

关节软骨病损的磁共振成像与关节镜检查的比较

[目的]对照膝关节软骨病损的MRI和关节镜表现,评价MRI对早期软骨病变诊断的临床价值。[方法]对临床上拟行膝关节镜检查的膝关节疼痛患者共26人27例膝关节,术前常规行T1加权快速自旋回波(FSET1WI)和质子密度加权快速自旋回波(FSE PDWI)2种MRI序列扫描,其中10例加做三维脂肪抑制扰相梯度回波(3D FS-FSPGR)序列。MRI分级结果并与关节镜下分级诊断结果比较。[结果]以关节镜诊断为标准,3D FS-FSPGR序列敏感度最高,可达96.5%,准确率达95.0%。在敏感度和准确度上3D FS-FSPGR>FSE FDWI>FSET1WI,与关节镜诊断的一致性上,3D FS-FSPGR的Kappa值达到0.776,一致性极佳,均明显优于FSE PDWI和FSET1WI(P值均<0.01)。[结论]3D FS-FSPGR序列能够准确反映软骨病变,并且对于早期的软骨病变亦能较真实体现,与关节镜诊断结果具有良好的一致性,而且通过三维重建对软骨病变进行立体定位诊断,应用前景广阔。     

颈椎后路钛合金脊柱内固定系统对术后MRI成像的影响

[目的]探讨颈椎后路钛合金内固定系统对术后MRI成像的影响。[方法]对6例行颈椎后路钛合金脊柱内固定的患者术后进行MRI检查,所用MRI为1.0 T及1.5 T的超导MRI系统,患者均进行矢状位的快速自旋回波序列（TSE）T1加权像（T1WI）和TSE T2加权像（T2WI）以及轴位的TSET1加权像扫描,然后对术后钛合金内固定的伪影特点及其对椎管内结构的影响进行分析。[结果]MRI伪影的大小为内固定大小的2~3倍,基本能够辨认出原来内固定物的形状,钛合金内固定植入物本身在T1和T2加权上都表现为低信号,其边缘在T1和T2加权上都有明确分界线的高信号区。在矢状面T1和T2加权和轴位T1加权上均可清晰显示脊髓和椎管内的结构。后路系统的连接棒伪影较小,只对紧邻的椎板和小关节处图像辨认有影响,对术后图像观察的影响较小。椎板钩的伪影较大,会影响对椎板附近结构的观察,特别是伸入椎管内的部分会影响对脊髓后部的观察。椎弓根螺钉钉尾部伪影较大,对紧邻的椎板和小关节处图像辨认有影响;正确植入的颈椎弓根螺钉伪影也较大,主要会影响对邻近部位椎管侧方、椎动脉、椎间孔、脊神经和后外侧突出的椎间盘等结构的观察。[结论]颈椎后路脊柱钛合金内固定术后患者进行MRI检查时,应该尽量选择快速自选回波序列进行扫描,当使用常规自旋回波序列扫描时,应尽量减少TE。医生在分析术后MRI图像时应该充分认识到钛合金内固定的伪影对图像的影响,以去伪存真,结合患者的临床表现作出正确的判断。     

MRI不同序列在骨挫伤诊断中的应用价值

[目的]探讨MRI不同序列在骨挫伤诊断中的应用价值。[方法]对2006年8月～2006年12月间的45例骨挫伤患者行MRI检查，MRI扫描前均经CR、DR或CT扫描证实没有发生骨皮质的断裂与移位。临床主要表现为局部肿胀、疼痛及活动受限。使用SiemensNovus1．5T超导MRI机器，脊柱扫描使用肢体线圈，膝关节扫描使用膝关节线圈，行矢状位、冠状位及横断扫描。扫描序列包括自旋回波序列（SE）T1WI、快速自旋回波序列（TSE）T2WI、梯度回波序列（FL2D）T2WI、脂肪抑制序列T2WI。[结果]自旋回波序列（sE）T1WI检出44例，检出率为97．7％，快速自旋回波序列（TSE）T2WI检出37例，检出率82．2％，梯度回波序列（FL2D）T2WI检出24例，检出率75％，脂肪抑制序列T2WI检出45例，检出率100％。骨挫伤检出率脂肪抑制序列T2WI高于TSET2WI（P〈0．05），TSET2WI高于FL2DT2WI（P〈0．05）。骨挫伤高场MRI信号改变主要表现为T1WI呈低信号，rISET2WI呈等高信号，FL2DT2WI呈混杂稍高信号，脂肪抑制序列T2WI呈明显高信号。边界不清，信号不均匀。[结论]对于骨挫伤脂肪抑制序列T2WI检查好于TSET2WI及FL2DT2WI，与SE T1WI相结合能够更敏感的发现骨挫伤改变。     

脊柱后部的孤立性结核

多数学者认为脊柱结核经常侵及椎体而很少侵及脊柱后部。本文回顾性研究了33例脊柱后部孤立性结核患者的MRI表现,探讨脊柱后部结核的发病情况和影像学特征。本组男16例,女17例,平均年龄28岁,均为经病理证实为脊柱后部附件结核的患者,但合并有椎体结核的患者除外。收集患者的所有临床资料:症状、体征、实验室检查(包括HIV感染的情况)、身体其他部位结核的侵犯情况、组织病理检查、抗结核治疗的效果等。影像学分析包括X线平片、CT、MRI,其中MRI检查利用轴面、矢状面、冠状面的自旋回波T1加权像、自旋回波T2加权像、梯度回波T2加权像,     

聚丙烯酰胺水凝胶注射隆乳后MRI检查方案及临床价值分析

目的:探讨聚丙烯酰胺水凝胶(polyamide hydrogel,PAMHG)注射隆乳后磁共振(magnetic resonance image,MRI)检查的标准化方案及临床应用价值。方法:30例曾注射PAMHG隆乳后取出术前的患者(共60只乳腺)行双侧乳腺MRI检查,其中14例行增强MRI,对MRI表现与手术、病理结果对照分析。结果:PAMHG于T1加权成像(T1-weighted image,T1WI)表现为与腺体相等信号,快速自旋回波(Turbo Spin Echo,TSE)T2加权成像(T2-weighted imaging,T2WI)即TSE-T2WI为高信号,结合特异性选择衰减反转恢复技术(Spectrally Selective Attenated Inversion Recovery,SPAI R)进行脂肪抑制(Fat Saturation,FS)的TSE-T2WI-SPAI R脂肪抑制(fat saturation,FS)像表现为明显高信号。其中83.3%(50/60)的乳腺中PAMHG内可见多发低信号间隔,83.3%(50/60)的乳腺中PAMHG无光滑囊壁;10%(6/60)PAMHG形态规则,可见边缘光滑均匀的囊壁;6.7%(4/60)PAMHG囊壁边缘不规则。PAMHG分布于皮下形成硬结占66.7%(40/60),分布于腺体内形成硬结占16.7%(10/60),分布于胸大肌下呈条带状占83.3%(50/60),乳腺后方肋间肌肌间隙出现PAMHG游走占16.7%(10/60)。所有PAMHG均无对比增强,增强后发现伴发的恶性导管内乳头状瘤及纤维腺瘤各1例。结论:横轴位T1WI、TSE-T2WI-SPAI R脂肪抑制像、矢状位TSE-T2WI-SPAIR脂肪抑制像结合多时相增强MRI为PAMHG注射隆乳后MRI检查的理想方案,对术前判定PAMHG分布及术后随访有重要的临床意义。     

MRI三维重建在聚丙烯酰胺水凝胶注射隆乳术后诊断中的应用

目的 探讨聚丙烯酰胺水凝胶注射隆乳术后分布的有效诊断方法.方法 对聚丙烯酰胺水凝胶注射隆乳术后的患者进行双侧乳房MRI薄层扫描(层厚1 mm,t2_ps3d_cor序列),在计算机上运用Amira电脑软件模块对扫描信息分别进行体积重建和表面重建,观察水凝胶的分布范围和部位,并计算其体积.结果 自2007年3月以来,于临床应用23例(46只乳房),其中5例(10只)水凝胶位于乳房后间隙,包膜完整,分布均匀,无移位;6例(12只)注射的水凝胶包膜不完整,形态不规则,边缘不整,呈多处散在的团块分布;11例(22只)水凝胶浸及胸大肌内、胸大肌后方、乳腺组织内和皮下,1例(2只)外院双侧取除水凝胶术后复查发现仍有少量残留,散在分布于乳腺及变性肌肉组织中.初次就诊的22例(44只)注射水凝胶的总体积为220.309～372.371 ml,平均306.328ml.结论 MRI三维重建能清晰显示注射物的体积和分布范围,可以有效地指导水凝胶的手术取除.     

脊髓型颈椎病患者术前MRI表现与术后神经功能恢复的相关性初探

MRI是一种无创检查方法,能清晰显示颈髓受压情况及髓内信号变化,对脊髓型颈椎病术前诊断及术后疗效预测具有重要的临床价值。本研究重点讨论脊髓型颈椎病术前MRI的表现与术后神经功能恢复的关系。临床资料1999年7月~2003年6月共收治脊髓型颈椎病患者42例,男23例,女19例;年龄24~71岁,平均45.5岁;病程6h~20年,平均1.1年。术前均行MRI检查。MRI设备为PHILIPS公司GyroscanIntera1.0T,快速自旋回波(TSE)。正交使用颈线圈,以自旋回波(SE)序例行矢状面和横断面扫描。矢状面T1加权TR/TE=450/15ms,T2加权TR/TE=3500/110ms,横断面T2加…     

原发性输尿管癌的磁共振诊断

目的分析输尿管癌的磁共振成像（MRI）表现，评价MRI对原发性输尿管癌的诊断价值。方珐用1．5T磁共振扫描仪，采用T2加权成像（T2WI）快速自旋回波序列（FSE）、脂肪抑制技术和MR尿路造影（MRU）检查，观察分析21例原发性输尿管癌的MRI表现。结果21例原发性输尿管癌中，5例表现为输尿管上端结节状病灶，4例表现为输尿管中段结节或条状病灶，12例表现为输尿管下段或下端结节或条状病灶。T1WI为等、略低信号，T2WI为等、高信号，增强扫描有轻、中度强化。MRU显示输尿管截然中断13例，鼠尾状狭窄中断4例，管壁不规则狭窄僵硬4例，与术中所见梗阻部位及程度完全相符。结论MRI结合MRU能清晰显示输尿管肿瘤的梗阻部位、梗阻程度以及累及范围、周围结构情况，选择合理的检查序列加做增强扫描，是诊断输尿管肿瘤的理想方法。     

3.0T MRI对硅凝胶乳房假体及假体破裂的诊断价值

目的探讨MRI各序列对显示硅凝胶乳房假体及假体破裂的诊断价值。方法回顾性分析自2016年3月至2018年6月采用3.0T MRI检查18例硅凝胶假体隆乳患者的影像学资料,并分析不同MRI扫描序列对显示和评价硅凝胶乳房假体的价值,特别在显示假体破裂方面的不同优势。结果全部36只假体中,20只良好,呈半球形,内部信号均匀,包膜完整,表面光滑;16只一般,其中8只假体完整,但其内部存在细小的短线和较长的弧形皱褶,并呈放射状延伸到假体外周,8只假体包膜不规整,存在不同程度的破裂和渗漏。T1WI、T2WI抑脂及DWI序列在评价硅凝胶乳房假体及假体破裂方面具有不同的优势,而3D T1WI增强序列具有薄层、可三维重建的优势,显示假体结构更加全面立体,对鉴别假体囊内破裂和假体较大的折叠方面具有优势;另外,假体破裂后周围组织强化的显示能够增加对假体破裂诊断的准确性。结论 MRI多序列联合扫描的方法可以更加全面地评价硅凝胶乳房假体,并准确显示假体破裂,特别是3D T1WI增强序列具有较高的应用价值。     

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.     

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.     

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.     

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.