胸腰椎结核的一期手术入路与方式的选择

目的探讨胸腰椎结核一期手术入路与手术方式的选择。方法对22例胸腰椎结核患者采用3种不同术式:胸、腰椎前路病灶清除植骨,同期钢板内固定;胸椎后路病灶清除植骨,同期经椎弓根内固定后凸畸形矫正;腰椎前路病灶清除植骨,同期后路经椎弓根内固定。结果通过8～12个月的随防,内固定无松动、断裂,植骨融合,后凸畸形矫正无丢失。结论采用合理的手术入路,彻底清除病灶,正确地使用内固定,一期手术可以提高胸腰椎结核的治疗效果。     

椎弓根系统内固定前路植骨融合治疗脊柱结核合并后凸畸形

目的 :总结应用椎弓根系统内固定加前路植骨融合术治疗脊柱结核合并后凸畸形的临床效果。方法 :回顾分析 1997年 3月～ 2 0 0 0年 10月行椎弓根系统内固定加前路植骨融合术治疗的脊柱结核合并后凸畸形患者 44例 ,对于胸椎或胸腰椎结核 ,采用单切口双入路 ,以使病灶和内固定器隔开。观察内容包括植骨融合率、后凸畸形矫正状况及截瘫恢复情况。随访时间 1.5～ 4.5年 ,平均 3 .0年。结果 :术后 1年患者均显示骨性融合 ;术后后凸畸形平均矫正 2 6 .7°。1.5～ 4.5年后随访 ,后凸角度平均丢失 3 .0° ;2 8例合并截瘫患者中 ,症状改善 2 5例 ,改善率 89.3 %。结论 :后路椎弓根系统内固定加前路植骨融合能矫正后凸畸形 ,阻止后凸畸形进一步发展 ,加强脊柱的稳定性 ,促进截瘫恢复。     

后路病灶清除椎弓根内固定治疗胸腰椎结核后凸畸形

目的 探讨经后路病灶清除椎问植骨椎弓根螺钉内固定治疗胸腰椎结核后凸畸形的疗效。方法 采用经后路病灶清除椎问植骨椎弓根螺钉内固定治疗23例胸腰椎结核后凸畸形患者。结果 术后随访1,5～3年,23例患者胸腰椎结核全部治愈,无复发病例,X线片显示椎问植骨全部融合,后凸矫正度无明显丢失。结论 该术式可在一次手术中同一切口内达到椎管内减压、脊柱矫形、融合和脊柱恢复稳定的目的,能获得满意效果。     

椎弓根系统内固定同期前路植骨治疗胸腰椎结核

目的　探讨应用椎弓根系统内固定同期前路植骨融合术治疗胸腰椎结核的临床效果。方法　 1998年 2月至2 0 0 3年 2月采用后路椎弓根系统内固定同期前路植骨融合的胸腰椎结核患者 36例 ,包括植骨融合率 ,截瘫恢复情况和后凸畸形矫正情况。随访时间 1～ 4 a,平均 2 .6 a。结果　所有患者均显示骨性融合 ,融合时间平均 7.9个月 ;2 4例合并截瘫患者中 ,症状改善 2 2例 ,改善率 91.7% ;术后后凸畸形平均矫正 2 9.4°,1～ 4 a后随访 ,后凸角度平均丢失 2 .1°。结论　后路椎弓根系统内固定同期前路植骨融合能加强脊柱的稳定性 ,促进骨融合和截瘫恢复 ,矫正后凸畸形。     

侧前方病灶清除椎弓根内固定治疗胸椎结核后凸畸形

目的观察侧前方病灶清除椎间植骨经椎弓根内固定术治疗脊柱结核并后凸畸形的疗效。方法胸椎结核并后凸畸形患者17例,男11例,女6例;年龄23～56岁,平均36.4岁。结核病损位于下胸椎,累及两或三个椎体。后凸成角15°～34°,平均25°。5例患者合并脊髓损伤,Frankel分级为C级2例、D级3例。手术方法为一期侧前方病灶清除椎间植骨经椎弓根内固定,抗结核药物治疗9个月。结果术后随访2~4年,切口一期愈合,椎间植骨全部融合,脊柱结核全部治愈,脊髓功能损害患者术后1年内完全恢复。术后后凸成角平均为7°,平均矫正18°,随访期间畸形矫正无明显丢失。结论侧前方病灶清除椎弓根内固定术治疗脊柱结核并后凸畸形,能够一期完成病灶清除、脊髓减压、脊柱稳定性重建和后凸畸形矫正。坚强的内固定可促进病椎植骨融合,有助于缩短术后药物治疗时间和提高脊柱结核治愈率。     

后路椎弓根系统内固定加前路植骨融合治疗胸腰椎结核

目的 :探讨应用后路椎弓根系统内固定加前路植骨融合术治疗胸腰椎结核的临床效果。方法 :回顾总结1 995年 3月至 2 0 0 0年 3月行后路椎弓根系统内固定同期前路植骨融合的胸腰椎结核患者 35例 ,包括植骨融合率、截瘫恢复情况和后凸畸形矫正状况。随访时间 1 5～ 5年 ,平均 3 4年。结果 :术后 1～ 1 5年所有患者均显示骨性融合 ;2 8例合并截瘫患者中 ,症状改善 2 6例 ,改善率 92 9% ;术后后凸畸形平均矫正 2 9 7° ,1 5～ 5年后随访 ,后凸角度平均丢失 2 9°。结论 :后路椎弓根系统内固定加前路植骨融合能加强脊柱的稳定性 ,促进骨融合和截瘫恢复 ,矫正后凸畸形     

同一切口椎弓根内固定侧前方病灶清除术治疗胸椎结核

目的探讨胸椎结核的手术方法和治疗效果。方法采用一期同一切口椎弓根内固定、后凸畸形矫形、病灶清除、椎体间自体骨植骨术21例。结果随访9个月~6年,患者切口愈合植骨全部融合,结核治愈无复发。后凸矫正16°。结论一期同一切口椎弓根固定、侧前方病灶清除、自体骨植骨手术治疗胸椎结核是可行的治疗方法。     

一期前路病灶清除后路椎弓根螺钉内固定治疗胸腰椎结核

目的探讨一期前路病灶清除植骨内固定治疗胸腰椎结核的疗效。方法23例胸腰椎结核患者采用一期前路或侧前方入路病灶清除、植骨,后路椎弓根螺钉固定、椎板间植骨融合。根据术前、术后X线片和MRI分析脊柱后凸畸形的矫正、植骨融合以及脊髓损害的恢复情况。结果23例均获得随访,时间12～24个月,患者均未出现结核播散,植骨全部融合,在3—6个月均获得牢固愈合,后凸畸形得到矫正,无侧弯畸形,Cobb角术前平均为（37±11）°,术后为（17±5）°。患者全身状况良好,受损神经均有不同程度的恢复。结论对有明显椎体破坏及脊髓受损的胸腰椎结核患者行一期前路病灶清除植骨内固定术,能有效防止远期手术矫正脊柱后凸畸形不理想以及早期阻止脊髓的不可逆损害,为脊柱融合提供一个稳定的力学环埔。     

经后路病灶清除RF矫形固定植骨治疗脊柱结核

目的　探讨治疗脊柱结核一期完成病灶清除、矫正脊柱后凸畸形、前后同时植骨融合的效果。方法　俯卧位 ,以病椎为中心作后正中切口 ,从病椎左右椎弓根骨膜下分离病灶 (在胸椎段 ,先切取左右肋骨后段 ) ,椎弓根短节段固定器 (RF系统 )矫正脊柱后凸畸形和椎体间高度 ,彻底清除结核病灶 ,前后同时植骨。结果　 15例患者结核病灶清除彻底 ,脊柱畸形矫正角由术前 18°～ 45°矫正到术后 3 4° ,椎体间高度由术前 62 6 %恢复到术后 98 2 % ,植骨块无移位。结论　该手术入路简捷 ,病灶清除彻底 ,畸形矫正满意 ,三柱固定植骨融合 ,后期脊柱稳定 ,缩短了卧床时间 ,减少了相应的并发症。     

一期后路内固定侧前方病灶清除植骨治疗胸腰椎结核

目的：观察椎弓根钉系统内固定加侧前方病灶清除治疗胸腰椎结核的疗效。方法：14例均采用椎弓根钉系统后路内固定加侧前方病灶清除植骨融合与脊髓减压术。结果：随访6个月～4．5年，结核全部治愈，植骨均融合，纠正后凸角度平均25．2°，丢失角度平均2．8°。结论：后路椎弓根系统内固定能有效矫正脊柱后凸畸形，稳定脊柱，促进植骨融合。     

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 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.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.