保留关节囊的全髋置换术治疗不稳定老年股骨颈骨折的病例对照研究

目的:探讨保留关节囊的髋关节置换术和传统的髋关节置换术治疗不稳定老年股骨颈骨折的疗效。方法:选取2010年1月至2015年1月初次接受全髋关节置换术的不稳定老年股骨颈骨折的患者120例,分为保留关节囊的全髋置换术组和传统的全髋置换术组,各60例。保留关节囊组与传统手术组患者的性别分别为(男/女):34/26,31/29;年龄分别为(73.4±4.4)岁和(72.3±4.1)岁。术后随访6个月,观察两组患者的手术时间、术中及术后出血量、住院天数、术后并发症发生率、术后髋关节脱位发生率和髋关节Harris评分。结果:保留关节囊的全髋关节置换术组和传统的全髋关节置换术组手术时间分别为(95.68±6.90)min和(93.39±7.90)min(P0.05);术中及术后出血分别为(998.78±15.20)ml和(1 000.25±16.80)ml(P0.05);住院时间分别为(10.74±2.90)d和(13.25±2.20)d(P0.05);术后1个月内髋关节脱位发生率分别为0%(0/60)和6.67%(4/60)(P0.05)。术后1~6个月的随访中两组患者均未出现髋关节脱位;两组患者术前Harris评分分别是42.18±5.90和43.68±8.20(P0.05),术后1个月时分别为58.53±5.10和49.38±4.90(P0.05),术后6个月分别是91.08±7.50和90.74±7.10(P0.05)。结论:直接外侧入路的保留关节囊的全髋置换术相对于传统不保留关节囊的全髋置换术不增加手术时间和术中出血,对缩短住院时间促进患者恢复,预防术后并发症,早期髋关节脱位,改善患者术后早期髋关节的功能具有重要作用。     

修复关节囊及外旋肌群对预防全髋关节置换术后关节脱位的作用

目的 探讨采用髋关节后外侧切口进行初次全髋关节置换术(THA)时修复关节囊及外旋肌的作用.方法 2002年1月至2006年6月,初次采用后外侧切口行THA 116例122髋,术中保留后方关节囊及外旋肌群,并且分别将其用疝缝线"8"字直接缝合至股骨大转子(修复组).将修复组THA术后脱位率与同期常规行THA(未修复关节囊及外旋肌,对照组)的255例266髋THA做比较分析. 结果术后6个月内,修复组仅1髋(1/122,0.8%)发生术后早期脱位;对照组则有15髋发生早期脱位(15/266,5.6%),早期脱位率差异有统计学意义(X2=4.914,P=0.027);两组术后6个月均无冉脱位. 结论采用后外侧切口进行THA时修复关节囊及外旋肌群技术能够有效预防术后早期脱位.     

保留修复后方关节囊及韧带对防止人工髋关节置换术后脱位的作用

目的 探讨保留并修复后方关节囊及韧带对防止后方入路人工髋关节置换术后髋关节后脱位的作用。方法 将503例采用髋关节后方入路的初次人工髋关节置换的患者分为两组:A组298例保留并修复后方关节囊及韧带,B组205例切除关节囊及韧带。比较两组术后髋关节后脱位发生率。结果 A组发生髋关节后脱位2例,发生率0.67%,B组发生髋关节后脱位6例,发生率2.93%,A组比B组术后髋关节后脱位发生率明显降低(P<0.05)。结论 保留并修复后方关节囊及韧带用以加强人工髋关节后方软组织支撑力量,有助于恢复髋关节的软组织平衡,增加关节稳定性,对防止后方入路人工髋关节置换术后髋关节后脱位有较为重要的作用。     

小切口不保留关节囊的全髋关节置换术

目的探讨小切口人工全髋关节置换术(THA)中不保留关节囊的安全性和实用价值。方法回顾性分析本组1999年1月至2009年1月行初次THA的患者,其中采用小切口不保留关节囊的THA(A组)141例163髋,男61例,女80例,年龄26～95岁,平均66.5岁;同期采用小切口不保留关节囊且未缝合修补外旋肌的THA(B组)88例101髋,男41例,女47例,年龄44～75岁,平均61.5岁;同期采用传统Gibson切口,保留关节囊的并修复外旋肌群的THA(C组)72例84髋,男30例,女42例;年龄33～80岁,平均68.3岁。对三组患者的手术切口长度、手术时间、出血量、髋脱位率、Harris评分进行比较。结果三组患者均获至少6个月的随访,A、B组在切口长度、手术时间方面与C组间的差异有统计学意义(P0.05);三组之间出血量、髋脱位、术后6个月的Harris评分间的差异无统计学意义(P0.05)。结论小切口THA具有微创一些优点,术中不保留关节囊,降低了手术难度,术野暴露充分,有利于髋臼假体及内衬的安装,并能有效缩短手术时间,不增加术后假体脱位率,从近期的疗效来看是一种安全快捷的髋关节置换方法。     

经后外侧入路初次行人工全髋关节置换术外旋肌群与关节囊修复对预后的影响

目的探讨经后外侧入路初次行人工全髋关节置换术(total hip arthroplasty,THA)时术中修复关节囊及外旋肌群对患者预后的影响。方法回顾分析2006年1月-2009年6月经后外侧入路初次行THA的股骨颈骨折患者159例,根据后方结构修复方式不同分为A、B、C、D 4组。4组患者性别、年龄、致伤原因、病程、骨折类型、合并内科疾病、假体选择等一般资料比较,差异均无统计学意义(P>0.05),具有可比性。A组(n=38)术中修复关节囊与外旋肌群;B组(n=39)术中仅修复关节囊,未修复外旋肌群;C组(n=41)术中仅修复外旋肌群,未修复关节囊;D组(n=41)关节囊与外旋肌群均未修复。对各组出血量、引流量、术后早期髋关节脱位率、Harris评分以及患髋内、外旋范围等进行比较分析。结果各组手术时间、术中出血量及引流量比较差异均无统计学意义(P>0.05)。患者均获随访,随访时间12～24个月,平均21.6个月。A、B、C、D组发生术后早期髋关节脱位分别有0、0、4(9.8%)、4(9.8%)例,髋关节脱位发生率组间比较差异有统计学意义(χ2=7.910,P=0.048)。术后6周及6、12个月,各组Harris评分均较术前显著改善(P<0.05);组间比较显示,术后6周及6个月D组显著低于A、B、C组,B、C组低于A组,差异均有统计学意义(P<0.05);术后12个月各组间比较差异均无统计学意义(P>0.05)。术后6周及6、12个月,各组患髋内旋范围比较差异均无统计学意义(P>0.05);术后6周及6个月,A、C组患髋外旋范围显著大于B、D组(P<0.05)。结论 THA术中修复外旋肌群及关节囊不增加术中出血量及引流量,可降低术后早期髋关节脱位风险,提高患髋关节Harris评分并恢复其外旋功能。建议经后外侧入路行THA术中常规修复关节囊及外旋肌群。     

改良Gibson小切口入路保留后外侧复合组织瓣髋关节置换术

[目的]介绍一种人工髋关节置换术的微创防脱位方法。[方法] 2013年1月~2018年12月采用改良的Gibson小切口入路,切口长度8~11 cm,保留髋关节后外侧复合组织瓣(关节囊和旋后肌群、臀中肌梨状肌等),70岁以上的股骨颈骨折采用半髋置换术,其余采用全髋置换术。[结果]手术时间45~120 min,平均(68.12±8.76)min。术中出血量60~550 ml,平均(210.74±17.45) ml。所有患者经至少24个月随访,36个髋关节术后均未发生过远近期髋关节脱位。术后6、12、24个月随访时采用Harris髋关节功能评分标准,分别平均为(92.64±10.22)分、(95.83±10.87)分和(96.76±11.02)分。测量双下肢长度患肢比健肢平均长(0.31±0.03) cm。[结论]采用改良的Gibson小切口入路保留髋关节后外侧复合组织瓣的髋关节置换术,组织切除少、小切口微创组织损伤轻,保留了髋关节的后外侧结构,髋关节软组织平衡破坏小,增加了术后髋关节的稳定性,预防了术后髋关节脱位的发生;切口愈合快;髋关节功能恢复快。     

两种髋关节后方关节囊重建法的对比研究

目的探讨两种髋关节后方关节囊重建方法对于全髋关节置换(total hip arthroplasty,THA)术后脱位的预防作用。方法 703例THA术按照有无进行髋关节后方关节囊修复重建分组进行统计分析。A组:398例,不修复后方关节囊;B组:179例,将后方关节囊和短外旋肌群缝合至短外旋肌在股骨大转子附着处;C组:126例,将后方关节囊和短外旋肌群经骨道缝合至股骨大转子上。结果 A组、B组和C组术后脱位率分别为7.04%、3.35%和0。C组的术后脱位率低于B组(P0.05),而B组的术后脱位率低于A组(P0.05)。结论两种后方关节囊修复方法均能有效预防全髋关节置换术后髋关节脱位,而经骨道缝合的方法能更可靠地恢复髋关节后方稳定性。     

前后联合入路全髋关节置换术治疗髋关节融合或强直

目的评估前后联合入路(Gibson后外侧入路+改良Hardinge入路)全髋关节置换术(total hip arthroplasty, THA)治疗髋关节融合或强直的安全性和有效性。方法回顾性分析2015年1月至2020年12月于上海长征医院治疗的37例因髋关节融合或强直而行THA的患者资料, 男28例、女9例;年龄(47.9±12.0)岁(范围26～72岁);强直性脊柱炎累及髋关节23例、陈旧性化脓性关节炎致髋关节融合9例、髋臼或股骨颈骨折后创伤性关节炎致髋关节融合5例。手术采用前后联合入路THA。评估内容包括手术时间、术中失血量、输血量、输血率、Harris评分、髋关节活动度、并发症等, 术后行髋关节X线片评估髋臼杯外展角、前倾角和股骨柄假体固定情况、假体周围骨溶解和异位骨化情况。结果 37例患者的手术时间为(147.6±16.8)min(范围129～190 min), 术中失血量为(850.0±10.8)ml(范围600～1 200 ml), 输血率为59%(22/37), 输血量为(420±45.0)ml(范围0～800 ml)。所有患者均获得随访, 随访时间为(4.2±0.9...     

全髋关节置换后外侧结构重建前后的生物力学变化

目的分析后外侧入路行全髋关节置换（THA）后外侧结构重建前后的髋关节生物力学变化。方法 2012年11月至2013年3月期间,行人工THA手术患者9例10髋,其中股骨头坏死患者3例4髋,发育性髋关节发育不良并骨关节炎患者侧3例3髋（CroweⅠ型2例,CroweⅡ型1例）,股骨颈骨折3例3髋;男4例,女5例;年龄41-75岁,平均59.67岁。常规采用后外侧入路、生物型假体。所有患者均行关节囊及外旋肌群修复,于关节囊及外旋肌群修复前后分别测定髋关节内收、外展0°,屈曲45°和屈曲90°内旋时,关节即将脱位时扭矩的大小,观察股骨大转子后方有无骨折、关节囊及外旋肌群有无撕裂、缝线有无开结及断线、坐骨神经损伤。结果关节囊及外旋肌群缝合前后扭矩有显著增加,屈髋45°时,缝合前扭矩测量为（7.88±5.87）N·m,缝合后扭矩为（14.03±6.81）N·m,差异有统计学意义（P〈0.01）;屈髋90°时,缝合前扭矩测量为（12.22±3.58）N·m,缝合后扭矩为（17.15±5.81）N·m,差异有统计学意义（P〈0.01）。术中出现1例大粗隆后缘骨折,1例后外侧结构缝合打结后,线结松动,1例缝线断裂情况,术后随访3个月,无关节脱位发生,无坐骨神经损伤。结论 THA术中后方关节囊及外旋肌群的修复可显著改善THA术后关节即刻稳定性。     

后外侧结构重建对后外侧入路全髋关节置换术后早期脱位的影响

目的 探讨后外侧结构重建对后外侧入路全髋关节置换术（total hip arthroplasty, THA）后早期脱位的影响。方法 回顾性分析2015年1月至2018年1月于我院行后外侧入路初次THA的病人120例,根据术中是否修补关节囊及外旋肌群将病人分为两组：观察组60例,舌形切开关节囊,术中将关节囊及外旋肌群原位缝合在大转子后方及臀中肌肌腱附着处;对照组60例,切除后关节囊,术中未进行外旋肌群修补重建。术后3个月内发生的脱位定义为早期脱位,比较两种方法对术后早期脱位率的影响。记录并比较两组病人的手术时间、术腔引流量、髋关节Harris评分。结果 观察组手术时间为（51.6±9.5） min,对照组为（45.1±7.5） min,对照组手术时间短于观察组,差异有统计学意义（t=2.008,P=0.036）。观察组术腔引流量为（129.6±11.9） ml,对照组为（136.8±12.4） ml,差异无统计学意义（t=1.187,P=0.269）。观察组未发现早期脱位,对照组早期脱位4例（4/60,脱位率为6.667%）,观察组术后Harris评分为（86.1±5.0）分,对照组为（85.9±5.5）分,差异无统计学意义（t=1.416,P=0.092）。结论 在后外侧入路THA过程中行后外侧结构重建的手术方式早期脱位率低,修补关节囊及外旋肌群对维持髋关节软组织平衡有一定意义。     

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.