后路枕骨髁螺钉置钉参数的研究进展

<正>枕颈不稳通常由外伤、先天畸形、肿瘤、炎症等因素引起,一般需行枕颈融合术~([1])。目前临床常用的手术固定方式为枕骨螺钉固定技术,该固定融合系统要求患者枕骨完整且无解剖变异~([1、2]),保证有足够面积和厚度供枕骨钢板固定,术中不可避免剥离大量软组织以暴露钢板螺钉附着处,且存在软组织损伤、硬膜外血肿、神经系统受损等严重并发症~([3、4])。随着固定技术和三维影像技术的发展,以及解剖研究的深入,脊柱外科医生已不满足于该融合固定技     

4种不同后路枕颈内固定方式的生物力学研究

目的 评价4种不同后路枕颈内固定方式的生物力学稳定性.方法 选择6例新鲜尸体枕颈部标本,在标本完整状态(NS)、枕寰枢失稳模型(DS)、后路枕骨螺钉 C2椎弓根钉固定 纵棒固定(AF)、后路枕骨螺钉 C2椎弓根钉 C3侧块螺钉 纵棒固定(BF)、后路枕骨螺钉 C2椎弓根钉固定 C3椎板钩 纵棒固定(CF)、后路枕骨螺钉 C3椎板钩 C4椎板钩 纵棒固定(DF),共6种状态下,依次用KD-1型三维运动实验机进行测量相应节段的运动参数,并进行统计学分析.结果 1.齿状突及横韧带切除后,枕颈部会严重失稳,即DS组运动范围(ROM)较NS组明显增大10-12 %,具有显著性差异(P＜0.05).2.枕颈失稳后,AF组ROM明显比DS组减小13-16 %(P＜0.05),与NS组仅相差5-6 %(P＞0.05).3.BF组ROM比失稳减小17-19 %(P＜0.05),更加有效抑制了枕颈部失稳.4.CF组ROM比DS组减小18-23 %(P＜0.05),亦有效抑制了枕颈部失稳.5.DF组ROM比DS组减小19-23 %(P＜0.05),也能有效抑制了枕颈部失稳,但椎板钩有滑动现象,相邻节段代偿运动加大.结论 枕颈融合固定时,C2椎体骨质良好者,单纯C2椎弓根固定已足够稳定;在颈椎有C2椎弓根固定再加上C3侧块螺钉或C3椎板钩时,固定更坚强可靠,但多牺牲了一个椎体的活动度;颈椎以C3椎板钩 C4椎板钩固定时,也能达到可靠的枕颈固定,但有侧方滑动的趋势,同时固定的节段最长,邻近节段退变会加剧.     

枕颈交界区前方手术入路的应用解剖研究进展

枕颈交界区包括枕骨大孔、寰椎、枢椎,枕颈交界区手术有后方入路、前方入路、侧方入路。经口咽入路是目前常用的枕颈交界区前方入路方式,但其显露困难、局部解剖复杂及手术并发症多,对外科医生具有挑战性。然而很多疾病无法单从后路或侧方入路解决,如难复性寰枢椎脱位、上颈椎及颅底前部的肿瘤等。Park等采用高位颈前咽后入路暴露枕颈交界区,而Kassam等采用内窥镜下经鼻入路来暴露枕颈交界区。笔者就枕颈交界区前方手术入路的应用解剖及相关技术综述如下。     

金属框架固定行枕颈融合术的生物力学研究

[目的]评价金属框架重建枕颈部的稳定性,为其临床应用提供力学依据。[方法]在7具完整成人枕骨颈椎(C0~6)标本上对横韧带切除齿状突切骨后失稳的C0~2节段,分别安装金属框架和棘突枕颈钢板内固定,通过摄像将1.53 Nm载荷下的三维运动记录脊柱三维运动稳定性评价方法,评价其重建枕颈部即时稳定性的效果。[结果]在1.53 Nm载荷作用下,金属框架组C0~2节段的前屈、后伸、侧弯和轴向旋转的ROM分别为5.9°、7.7°、5.6°、11.2°,比棘突枕颈钢板组分别缩小了157.6%、68.8%、58.9%、131.3%。[结论]枕颈框架组较有效地恢复枕颈部失稳后的即时稳定性,是枕颈融合术中较可靠的内固定方法。     

儿童颅颈交界融合术自体肋骨结构性植骨

[目的]介绍儿童颅颈交界区后路固定融合手术中自体肋骨结构性植骨的手术技术和初步临床效果。[方法]对2例颅颈交界区疾患的儿童患者实施寰枢椎/枕颈后路植骨融合内固定+取肋骨术。行颈后路正中切口，常规置入寰枢椎钉-棒/枕颈板-钉-棒系统内固定，高速磨钻于寰椎后弓/枕骨后下缘及枢椎椎板上缘打磨植骨槽，然后于后胸壁肩胛下角下沿肋骨方向斜切口，取合适长度肋骨修整后，卡入寰椎后弓/枕骨后下缘与枢椎椎板植骨槽之间进行结构性植骨。[结果]2例患者手术过程顺利，未出现血气胸。术后未出现肋骨取骨区并发症，2例患者术后症状明显改善，术后JOA和VAS评分均显著改善。术后3个月随访复查CT见植骨已融合，肋骨取骨处已膜内成骨重建。[结论]儿童颅颈交界区后路固定融合手术中，自体肋骨结构性植骨是一种安全且有效的植骨方式。     

使用枢椎椎弓根螺钉和枕颈固定板的枕颈融合术

目的观察一种借助于枢椎椎弓根螺钉的枕颈固定装置治疗寰枢关节不稳定的效果。方法从2001年6月至2003年3月用自行设计的一套由椎弓根螺钉和枕颈固定板组成的枕颈固定器,治疗了38例寰枢关节不稳定的患者,其中24例有寰椎枕骨化。沿枢椎椎弓峡部的纵轴安置椎弓根螺钉,将枕颈固定板预弯后固定于枕骨,用螺母锁定固定板与椎弓根钉的过程中,利用固定板的曲度,使寰枢关节充分复位。植骨于枕骨与枢椎后弓间。结果36例获得了随访,平均18个月,均获得了骨性融合。没有神经、血管损伤和断钉、断板的病例。结论使用枢椎椎弓根螺钉和枕颈固定板的枕颈固定器不仅有可靠的、短节段固定作用,而且便于寰枢关节复位。     

新型蝶形枕颈内固定系统固定的生物力学稳定性研究

目的 :评价新型蝶形枕颈内固定系统固定的生物力学稳定性。方法 :选取6具新鲜冰冻人体枕颈部标本,年龄为20~35岁,男3具,女3具。每具标本解剖截取其C6以上的部位,保留枕骨粗隆以下的颅骨骨性结构及其与颈椎相连的韧带部分,仔细剔除附着于颅脊交界区骨性结构周围的肌肉组织,完整地保留该区域的各种韧带与关节囊,制作为正常模型(N组),用Motion Analysis三维运动测试机测量C0~C3节段的屈伸、侧屈及旋转三维运动范围(ROM);然后离断寰枢椎间横韧带,制成寰枢椎的失稳模型(UN组),测量C0~C3节段的屈伸、侧屈及旋转三维ROM;再将每具标本进行新型蝶形枕颈系统固定,蝶形枕骨板先后依次以11枚螺钉固定(A组)、以7枚螺钉固定(B组)及以3枚螺钉固定(C组),最后每具标本进行SUMMIT系统固定(D组),每种固定后测量C0~C3节段的屈伸、侧屈及旋转三维ROM。对蝶形枕骨板不同的固定方式与寰枢正常模型、失稳模型及SUMMIT系统固定进行组间比较,比较A、B、C、D组内固定方式中枕颈部的屈伸、侧屈及旋转三维稳定性。结果:在6种不同工况下,A、B、C、D组固定方式稳定性均优于正常组及失稳组,组间比较有统计学差异(P0.05)。在前屈、后伸、左右侧屈方向上的比较,A、B、C、D四种内固定方式组间无统计学差异(P0.05)。而在左右旋转方向上,A、B、C、D四种不同固定方式组间比较有统计学差异,其中B、C、D三种内固定方式间的比较无统计学差异(P0.05),而A组与B、C、D三组间的比较均有统计学差异(P0.05)。结论:新型蝶形枕颈内固定系统固定与SUMMIT内固定系统固定一样能提供有效的力学固定强度,其中以11枚螺钉固定的新型蝶形枕颈内固定系统固定在旋转稳定性上更优。     

枕骨钉结合枢椎椎弓根螺钉内固定术治疗寰枕融合并寰枢椎脱位

[目的]探讨单纯后路枕骨钉结合枢椎椎弓根螺钉内固定术治疗先天性寰枕融合并寰枢椎脱位的治疗效果。[方法]回顾性分析2008年4月~2013年12月本科收治的34例先天性寰枕融合并寰枢椎脱位患者的临床资料。采用单纯经后路枕骨螺钉和C_2椎弓根内固定,应用提拉撑开复位技术治疗此类畸形,术前及术后3、6个月及末次随访时行颈椎X线、枕颈区3D-CT、MRI检查,所有患者均根据术后影像学检查和日本骨科协会(Japanese Orthopedic Association Scores,JOA)评分评价影像和临床效果。[结果]随访9~38个月,平均16.5个月。患者症状有不同程度改善,无感染、死亡病例。术后影像学检查显示,所有患者复位满意,减压充分,且形成良好骨性融合。比较术前及术后随访时JOA评分和影像数据,结果示术前与术后末次随访时JOA评分及影像数据差异均有统计学意义(P0.05)。[结论]单纯后路枕骨钉结合枢椎椎弓根螺钉内固定提拉撑开复位技术,可以安全有效地治疗寰枕融合并寰枢椎脱位。     

前路枕骨髁至枢椎螺钉内固定技术

该文作者报道一种前路自枢椎经两侧寰枢关节至枕骨髁螺钉内固定的枕颈融合技术,并与传统的后路枕颈融合内固定技术进行生物力学比较研究。具体方法是:采用6具新鲜成人完整标本,将枢椎齿突予以切除造成枕寰枢不稳,分别采用后路钢丝结扎、后路C1/C2经关节螺钉加钢板内固定和前路枢椎至枕骨螺钉内固定技术进行枕颈融合,每组各2具标本。运用光电测定系统对三组标本进行生物力学测定,主要检测各运动节段(Oc～C1、Cl～2)之间的运动范围(ROM)和中立区(NZ)的运动参数。对实验数据进行统计学分析。结果显示:在屈曲和伸展运动时,后路经关节螺钉加钢板内固定具有最大的力学稳定性,优于后路钢丝结扎和前路枢椎一枕骨螺钉技术。在侧屈和旋转运动时,前路枢椎一枕骨螺钉技术与后路经关节螺钉加钢板内固定技术在生物力学稳定性上无显著差异,均优于后路钢丝结扎技术。该文作者认为,前路枢椎一枕骨螺钉技术在枕颈融合时,可提供足够的力学稳定性;其技术设计简单,符合微创原则,尤其适用于后路枕颈融合失败后的翻修手术。     

借助于枢椎椎板钉重建寰枢关节稳定的初步临床报告

目的 探讨以枢椎椎板置钉法完成寰枢或枕颈固定,用以治疗寰枢关节不稳的可行性.方法 对枢椎椎弓根畸形或椎动脉异位的病例以枢椎椎板置钉的方法 完成寰枢或枕颈固定.如果一侧枢椎椎弓根是大致正常的,就在该侧用椎弓根钉固定,在对侧用枢椎椎板钉固定.在寰椎以侧块螺钉固定,在枕骨以短螺钉固定.用连接棒在寰枢或枕枢间连接.在寰枢后弓间或枕骨与枢椎椎弓间植入颗粒状松质骨.结果 共完成了9个病例,其中寰枢固定2例,枕颈固定7例.使用一侧枢椎椎弓根钉固定、另一侧枢椎椎板钉固定6例,两侧均为椎板钉固定3例.9例均得到随访,随访时间4-13个月(平均9个月).所有病例均得到骨性融合.有神经症状的8例中,症状改善情况为:优3例,良1例,可2例,无变化2例.1例椎板钉进入了椎管.所有病例均没有出现脊髓和椎动脉损伤症状.结论 枢椎椎板置钉操作简便、安全,固定效果可靠.可以作为枢椎椎弓根置钉固定的后备方法 ,适用于椎弓根畸形或椎动脉异位的病例.     

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.