OLIF技术在腰椎融合术后邻椎退变性疾病中应用的疗效分析

目的 评价斜外侧腰椎椎体间融合术(oblique lateral interbody fusion, OLIF)在腰椎融合术后邻椎退变性疾病(adjacent segment disease, ASD)中的应用价值。方法 回顾性分析2020年10月～2022年10月本院经OLIF技术治疗的18例腰椎融合术后ASD患者,记录术中出血量、手术时间等指标;分析术前、术后1周、随访1个月、3个月及6个月时的疼痛VAS评分及Oswestry功能障碍指数(Oswestry disability index, ODI),评价OLIF的临床疗效。结果 与术前比较,18例患者术后1周、随访1个月、3个月、6个月时的腰痛VAS、下肢痛VAS评分及ODI指数均显著降低,差异有统计学意义(P<0.05);未出现严重的并发症。结论 OLIF技术在脊柱退变性疾病中已被广泛应用,在腰椎融合术后ASD中应用可明显减少手术创伤及出血,缩短住院时间及卧床时间,并发症发生率低,疗效肯定。     

经皮椎间孔入路内镜下治疗老年腰椎融合术后邻椎病

目的讨论经皮椎间孔入路内镜下治疗老年腰椎融合术后邻椎病的临床疗效。 方法回顾性收集2015年1月至2016年8月山东省文登整骨医院脊柱脊髓科收治的老年腰椎融合术后出现邻椎病的患者34例,男性25例,女性9例,年龄61~81岁,平均年龄（66±7）岁。全部患者采用经皮椎间孔入路内镜减压手术。记录手术时间及术中应注意的事项。在术前、术后1、6、12个月及末次随访时,按MacNab标准进行临床疗效的评价,进行腰部及下肢的疼痛视觉模拟评分（VAS）及Oswestry功能障碍指数（ODI）;在6个月随访时,行腰椎MRI检查评估神经根减压状况,并进行腰椎正侧位、动力位片评价本次手术节段的稳定性。 结果34例患者均顺利完成手术,随访时间为24~44个月,平均（32±7）个月。手术时间54~142 min,平均（68±30）min。重复测量的方差分析显示,术后1、6、12个月、末次随访时,ODI较术前明显下降,差异具有统计学意义（F=2008.780,P<0.001）;腰痛VAS评分较术前明显下降,差异具有统计学意义（F=599.821,P<0.001）;下肢痛VAS评分较术前明显下降,差异具有统计学意义（F=601.751,P<0.001）;6个月随访时,改良MacNab标准评估：优27例、良5例、可2例,优良率为94.12%。1例出现置管过程中导丝断裂;1例出现出口神经根外膜的撕裂;1例患者出现出口根刺激症状。末次随访时,3例椎间失稳。未发生神经根及硬膜囊的损伤,未发生手术节段错误。 结论经皮椎间孔入路内镜治疗老年人腰椎融合术后邻椎病,创伤小,临床疗效好。     

实时三维CT导航引导脊柱内镜下腰椎椎间融合术的临床研究北大核心CSCD

目的 探讨实时三维CT导航引导脊柱内镜下腰椎椎间融合术的疗效,总结手术技术要点及存在问题。方法 2020年4月—2021年10月,27例腰椎疾病患者接受实时三维CT导航引导脊柱内镜下腰椎椎间融合术。男18例,女9例;年龄48~84岁,平均63.2岁。疾病类型:单纯腰椎管狭窄症6例,单纯腰椎失稳症1例,腰椎管狭窄合并腰椎失稳症9例,退行性腰椎滑脱症3例,峡部裂性腰椎滑脱症6例,复发性腰椎间盘突出症2例。患者均存在下肢神经症状,其中单侧15例、双侧12例。病程1~300个月,中位数24个月。术中经椎间孔入路8例、经关节突入路18例、联合入路1例;共32个节段融合,其中单节段融合23例、双节段融合3例、三节段融合1例;L_(2、3) 1例、L_(3、4) 4例、L_(4、5) 20例及L_(5)、S_(1) 7例。记录手术时间、术中估计失血量(intraoperative estimated blood loss,IEBL)及围术期并发症;术后1周CT测量手术节段椎间隙高度改善情况,评价经皮椎弓根螺钉及Cage植入的准确性;评估术前及术后1周、末次随访时腰腿部疼痛视觉模拟评分(VAS)、日本骨科学会(JOA)评分、Oswestry功能障碍指数(ODI),末次随访时采用改良MacNab标准评价患者对手术疗效的满意度。结果 手术时间255~805 min,平均424.9 min;IEBL为150~290 mL,平均219.3 mL。患者均获随访,随访时间4~22个月,平均12.4个月。术后1周及末次随访时,患者腰痛VAS评分、腿痛VAS评分、ODI均较术前下降,JOA评分升高,差异有统计学意义(P<0.05);末次随访时与术后1周比较差异无统计学意义(P>0.05)。末次随访时,根据改良MacNab标准,患者对疗效满意度达优26例、中1例,优良率96.3%。1例术中L_(5)神经根束支部分损伤,对症治疗3个月后部分恢复。术中共植入118枚经皮椎弓根螺钉(其中116枚经导航引导下植入)、33枚Cage(均经导航引导下植入),术后1周复查CT评判导航引导下植钉准确率99.1%、Cage植入准确率97.0%,手术节段椎间隙高度较术前提升(P<0.05)。1例患者随访期间Cage出现轻度下沉,但所有患者内固定物未见明显松动。结论 实时三维CT导航引导脊柱内镜下腰椎椎间融合术安全可靠、初步应用疗效满意,存在的技术难点问题有待工具设备进一步研发与优化加以解决。     

单节段腰椎退行病内镜下经椎间孔腰椎体间融合

[目的]探讨经皮全内镜下经椎间孔椎体间融合术治疗单节段腰椎疾病的疗效。[方法] 2015年6月—2019年5月,对24例单节段腰椎疾病患者采用经皮全内镜下经椎间孔椎体间融合术治疗。评价临床与影像资料。[结果] 24例患者均顺利完成手术,无严重并发症。随时间推移,腰痛VAS评分、腿痛VAS评分、ODI评分均显著减少(P<0.05)。影像方面,术后3个月及末次随访时,椎间隙高度较术前显著增加(P<0.05),L₂S₁前凸角略有增加,但差异无统计学意义(P>0.05)。所有患者均获得椎间融合,无椎间融合器移位、螺钉及连接棒移位断裂等发生。[结论]采用经皮全内镜下经椎间孔椎体间融合术治疗单节段腰椎疾病疗效满意。     

单边双通道内镜与单通道Delta内镜腰椎融合术治疗腰椎退行性疾病的对比

目的 比较单边双通道内镜(unilateral biportal endoscopy, UBE)与单通道Delta内镜腰椎融合术治疗腰椎退行性疾病的早期疗效及安全性。方法 回顾性分析我院2020年10月～2021年10月46例内镜下腰椎椎间融合术治疗单节段腰椎退行性疾病的资料，其中19例采用UBE,27例采用Delta内镜。比较2组手术时间、术中出血量、术中透视次数、术后住院时间及术后并发症，以及术前和术后1个月、3个月、末次随访时疼痛视觉模拟评分(Visual Analogue Scale, VAS)、Oswestry功能障碍指数(Oswestry Disability Index, ODI)、日本骨科协会(Japanese Orthopedic Association, JOA)评分，末次随访采用改良MacNab标准评估疗效。结果 2组手术顺利完成，未出现严重并发症。UBE组手术时间短[(158.4±13.6)min vs.(196.6±17.3)min,t=-7.996,P=0.000],2组术中出血量、透视次数、术后住院时间、术后并发症等差异无统计学意义(P>0.05)。...     

显微内窥镜下椎管减压椎间融合治疗腰椎失稳症的近期疗效观察

目的:探讨显微内窥镜下椎管减压、椎间植骨融合治疗腰椎失稳症的临床疗效。方法:2006年7月～2008年12月共收治退变性腰椎失稳症患者48例,患者均有持续性腰痛,伴有双侧臀部、双侧或一侧下肢疼痛、麻木,均有间歇性跛行、腰部屈伸活动受限。腰椎动力位X线片示均为单节段失稳,椎间水平移位≥4mm或椎间角度变化≥11°,但滑移不超过Ⅰ度。均采用显微内窥镜下经椎板间隙入路椎管减压、经椎间孔入路椎体间自体骨粒、椎间融合器置入椎体间融合术。术后2周(出院时)拍腰椎正侧位X线片,术后每3个月复查X线片。按照Macnab标准评价疗效,随访观察近期治疗效果。结果:手术时间70～150min,平均95min;出血量110～210ml,平均150ml。随访6～18个月,平均12个月。术后症状及体征均有不同程度缓解,术中、术后均无任何并发症发生。末次随访时按照Macnab标准,优24例,良20例,可4例。X线检查未见cage移位、下沉,37例随访超过9个月的患者均见椎间隙变模糊,过伸过屈侧位X线片示椎体间无移位,但所有患者均未观察到椎间隙消失和骨小梁完全通过椎体间上下终板。结论:显微内窥镜下椎管减压及椎间融合术治疗退变性椎间失稳症具有创伤小、早期疗效满意等优点,长期疗效及融合情况需进一步随访观察。     

年龄及融合术式与腰椎后路融合术后邻近节段退变性疾病再手术的关系

目的:探讨患者初次手术时年龄及融合术式与腰椎后路融合术后邻近节段退变性疾病再手术的关系。方法:从2013年3月～2017年3月在我院脊柱外科接受腰椎后路融合术治疗的患者中,选取腰椎后路融合术后发生邻近节段退变性疾病且再次进行手术治疗的113例患者作为再手术组,初次手术时年龄49～79岁(56.4±2.1岁),其中接受后路椎体间融合术(PLIF)67例,后外侧腰椎融合术(PLF)23例,经椎间孔椎体间融合术(TLIF)21例;随访时间9～42个月(24.6±1.1个月)。同时,匹配226例腰椎后路融合术后未发生邻近节段退变性疾病的患者作为对照组,初次手术时年龄46～82岁(57.1±1.1岁),其中接受PLIF 97例,PLF 45例,TLIF84例,随访时间为9～48个月(24.9±0.6个月)。对两组患者接受融合术前和末次随访时(2017年12月)进行腰痛VAS和腰椎JOA评分。应用卡方检验、t检验比较两组患者的初次手术时年龄、性别分布、婚姻情况、文化程度、体质指数(BMI)、融合术式、融合节段个数、椎板是否切除及是否悬浮固定的分布差异,利用Logistic回归分析初次手术时年龄及融合术式与腰椎后路融合术后邻近节段退变性疾病再手术的关系。结果:单因素分析结果显示,两组间性别分布、婚姻情况、文化程度、BMI的差异无统计学意义(P0.05),但初次手术时年龄、融合术式、融合节段个数、椎板是否切除及是否悬浮固定的差异有统计学意义(P0.05)。Logistic回归分析显示,两组患者的年龄分布差异有统计学意义,其OR值为1.23,95%CI为1.12～3.56;两组患者接受PLF、TLIF对比接受PLIF的分布的差异有统计学意义,其OR值及95%CI分别为0.76(0.34～0.89)、0.68(0.25～0.82)。调整融合术式、融合节段个数、椎板是否切除及是否悬浮固定等变量后,初次手术时年龄≥60岁对比60岁的患者,a OR值为2.54,95%CI为1.23～3.56;调整年龄、融合节段个数、椎板是否切除及是否悬浮固定等变量后,接受PLF、TLIF的患者对比接受PLIF的患者,融合术后发生邻近节段退变性疾病需要再次手术的风险均明显降低,其a OR值及95%CI分别为0.54(0.42～0.77)、0.47(0.34～0.83)。再手术组和对照组末次随访时的腰痛VAS评分、腰椎JOA评分与术前比较均有统计学差异(P0.05),且再手术组末次随访时腰痛VAS评分和腰椎JOA评分均优于对照组,差异有统计学意义(P0.05)。结论:接受腰椎后路融合术治疗的患者年龄越大,术后发生邻近节段退变性疾病需要再次接受手术治疗的可能性也越大。同时,接受PILF比PLF、TLIF更可能导致术后邻近节段退变性疾病再手术。     

全内镜下和可扩张通道下微创经椎间孔腰椎融合术治疗单节段腰椎退行性疾病

目的比较全内镜下微创经椎间孔入路腰椎融合术(MIS-TLIF)和可扩张通道下MIS-TLIF治疗单节段腰椎退行性疾病的临床疗效。方法对40例单节段腰椎退行性疾病患者分别采用全内镜下MIS-TLIF(内镜组,20例)和可扩张通道下MIS-TLIF(通道组,20例)治疗。比较两组手术指标、疼痛VAS评分、JOA评分、融合情况,术后12个月采用腰椎功能MacNab标准评价疗效优良率。结果患者均获得随访,时间12～20个月。与通道组相比,内镜组手术时间长、切口长度短、术中出血量少、术后引流量少、术后下地时间短,差异均有统计学意义(P=0.001)。术后3个月JOA评分内镜组高于通道组(P=0.001),术后3 d和3个月VAS评分内镜组低于通道组(P=0.001)。术后12个月,疗效优良率内镜组为18/20,通道组为17/20,两组比较差异无统计学意义(P=0.691)。结论全内镜下MIS-TLIF与可扩张通道下MIS-TLIF治疗单节段腰椎退行性疾病均可取得较好的临床疗效,但全内镜下MIS-TLIF具有创伤小、出血少、功能恢复快等优势。     

退行性腰椎侧凸的手术治疗选择

[目的]探讨退行性腰椎侧凸手术治疗的选择,观察手术治疗的疗效。[方法]回顾分析2010年10月²013年05月,本院收治的26例经手术治疗的退变性腰椎侧凸病例,根据临床症状、体征和影像学资料,结合患者的身体条件和基础疾病,分别采用单纯减压,后路椎管减压、椎弓根螺钉内固定、椎间植骨融合术治疗退变性腰椎侧凸。观察患者术后症状缓解和功能改善情况。[结果]26例患者均获得随访,术后平均随访27.5个月(242013年05月,本院收治的26例经手术治疗的退变性腰椎侧凸病例,根据临床症状、体征和影像学资料,结合患者的身体条件和基础疾病,分别采用单纯减压,后路椎管减压、椎弓根螺钉内固定、椎间植骨融合术治疗退变性腰椎侧凸。观察患者术后症状缓解和功能改善情况。[结果]26例患者均获得随访,术后平均随访27.5个月(24⁴3个月),术后疼痛VAS评分和Oswestry功能障碍指数的改善率分别为(68.9±2.4)%和(80.5±4.1)%。侧凸平均矫正率(60.4±3.7)%,随访无断钉、断棒发生。[结论]对于退变性腰椎侧凸,应采取个体化治疗,严格掌握手术适应证,治疗以缓解患者症状为主要目的。     

腰椎手术失败综合征的再手术治疗

目的: 探讨下腰椎手术失败综合征 (FailedBackSurgerySyndrom, 简称FBSS) 再次手术的手术方案。方法: 回顾二院再次手术确诊资料完整的腰椎手术失败综合征患者 42例, 综合临床、影像学表现及手术后结果进行分析。再手术方法: 半椎板切除减压 16例; 全椎板切除减压椎弓根钉系统内固定椎体间植骨术 26例, 其中椎间Cage植骨融合术 8例。结果: 全组病例经 3年~8年5个月, 平均 5年以上随访, 疗效优者 19例, 良 14例, 可 7例, 差者 2例, 优良率 78. 57%。结论: 严格再次腰椎手术指征、正确的术式选择、精细的手术技巧及术后综合预防是提高FBSS手术疗效的关键。     

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.