前后路联合一期全椎体切除脊柱重建治疗胸腰椎恶性肿瘤

[目的]探讨前后路联合一期全椎体切除脊柱重建治疗胸腰椎肿瘤的疗效及优越性。[方法]应用前路全椎体切除、钛网植骨或钛网骨水泥椎体重建和后路椎弓根钉系统内固定治疗胸腰椎恶性肿瘤24例。[结果]术后随访9—35个月。所有患者疼痛症状均消除，9例不完全截瘫患者平均恢复1．8级（Frankel分级），2例大小便功能障碍者均恢复，4例远处重要脏器转移死亡，所有随访达6—9个月的病例均骨性融合，无内固定松动断裂，1例术后1年复发。[结论]前后路联合一期全椎体切除脊柱重建治疗胸腰椎恶性肿瘤能有效切除肿瘤、重建脊柱稳定性、提高病人生活质量。     

前路一期病变椎体切除并重建治疗胸腰椎结核并后凸畸形

目的:观察前路一期病变椎体切除、人工椎体或钛网融合器植骨替代、椎体钉板或钉棒系统内固定治疗连续两个及以上节段胸腰椎结核并后凸畸形的疗效。方法:34例病变累及连续两个及两个以上椎节的胸腰椎结核患者,术前后凸Cobb角27.8°￣65.4°(38.6°±10.3°),一期行前路病变椎体切除,椎间撬拔撑开复位,人工椎体或钛网融合器植骨替代,辅以椎体钉板或钉棒系统短节段邻近椎节内固定,重建脊柱稳定性,术后均给予短疗程化疗。观察术后局部疼痛缓解、脊髓神经功能恢复、后凸畸形矫正及脊柱稳定性情况。结果:患者术后局部疼痛缓解,术前伴有脊髓神经损伤的12例患者术后神经功能均有不同程度恢复。影像学检查示脊柱内固定物位置良好,椎体序列恢复良好,椎间高度恢复。后凸Cobb角矫正至2.1°￣14.2°(7.5°±8.3°),平均矫正31.2°±8.5°。随访18￣54个月,平均35个月。末次随访时后凸矫正度丢失4.3°±3.8°,均无结核复发。结论:连续两个及两个以上节段的胸腰椎结核采用前路一期行病变椎体切除有利于病灶彻底清除,减少复发;也有利于椎管彻底减压。前路椎体替代、植骨内固定重建脊柱稳定性可更好地纠正和预防脊柱后凸畸形。     

脊柱转移瘤病椎切除及稳定性重建

目的 探讨脊柱转移瘤切除、融合及稳定性重建在治疗转移性脊柱肿瘤中的必要性和可行性.方法 2002年6月-2007年8月对11例脊柱转移瘤患者行前路病椎切除自体髂骨植骨钛板内固定术或联合后路椎板切除减压术治疗,随访观察患者术后局部疼痛缓解,脊髓神经功能恢复及脊柱稳定性情况.结果 术后颈肩腰背痛及放射痛基本缓解,早期开始肢体功能锻炼,术后3～5周佩戴支具离床活动.随访5个月～2年,患者神经压迫症状明显改善.内固定物无松动、断钉现象,椎体尤塌陷结论前路手术切除病变椎体并自体髂骨植骨前路钛板内固定重建脊柱稳定性或联合后路椎板切除减压治疗脊柱转移瘤是可行性的,可提高患者生存期内的生活质量.     

人工椎体置换治疗胸腰椎结核的临床疗效观察

目的探讨人工椎体置换治疗胸腰椎结核的临床疗效。方法回顾性分析胸腰椎结核28例,其中累及1个椎体5例,2个椎体22例,3个椎体1例。对该组患者行椎体大部切除,撑开复位后行可调式中空笼状钛合金人工椎体植骨置换、前路椎体钉棒系统邻近椎节固定,观察术后局部疼痛缓解、脊柱稳定性及后凸畸形的矫治情况。结果所有患者术后疼痛缓解,切口均一期愈合,随访12～36个月,平均17个月,局部无复发,影像学检查椎体序列恢复良好,椎间高度恢复,达到骨性愈合,后凸畸形基本矫正。结论胸腰椎结核行人工椎体置换,既能彻底切除病灶防止复发,又能矫正畸形,有效重建脊柱稳定性,恢复脊柱支撑功能。     

直视下椎体成形术联合后路内固定治疗胸腰椎肿瘤的临床效果

目的探讨直视下椎体成形术联合脊柱后路减压椎弓根钉棒内固定治疗胸腰椎转移瘤的临床疗效。方法回顾性分析自2010-01—2013-01诊治的胸腰椎肿瘤40例,按手术方法分为直视下经皮椎弓根穿刺椎体成形术联合脊柱后路减压椎弓根钉棒内固定术组及侧前路胸腰椎肿瘤切除钛板内固定术组。结果 2组VAS评分术后较同组术前明显降低,2组间比较差异无统计学意义;2组脊柱后凸角度(Cobb角)较同组术前减少;2组伤椎上下椎体之间的高度较同组术前增大。结论直视下椎体成形术联合后路椎板切除减压椎弓根钉棒内固定治疗胸腰椎转移瘤,能较快缓解疼痛症状,并且止痛效果维持时间久等优点,并可恢复并维持椎体高度及矫正后凸畸形的作用。     

椎弓根钉内固定治疗多节段胸腰椎骨折

目的探讨多节段胸腰椎复杂骨折手术治疗效果。方法采用后路长节段椎弓根钉系统复位固定方法,恢复伤椎高度及脊柱生理弯曲,使后纵韧带复张,椎管间接减压或有限椎板切除减压、植骨融合治疗胸腰椎多节段骨折21例。结果术后椎体高度、脊柱生理弧度明显恢复。21例均获随访,时间3个月～6年。椎体高度无明显丢失,无断钉、断棒。Frankel分级：A级2例恢复至B级1例、1例无恢复;B级3例恢复至C级1例、D级1例、1例无恢复;C级5例恢复至D级3例、E级2例;D级5例恢复至E级3例、2例无恢复;E级6例仍为E级。结论多节段胸腰椎骨折影响脊柱稳定性,后路长节段椎弓根钉系统复位固定能够恢复脊柱稳定性及生理弧度,为改善神经功能提供条件。     

选择性增加伤椎单侧置钉内固定治疗胸腰段椎体骨折

目的探讨选择性增加经伤椎椎弓根置钉短节段钉棒内固定治疗胸腰段椎体骨折的临床效果。方法选择22例胸腰段椎体骨折,采用增加经伤椎椎弓根置钉短节段钉棒内固定,观察患者术前、术后伤椎前缘高度、脊柱Cobb角、神经恢复情况。结果术后伤椎前缘高度、脊柱Cobb角较术前明显恢复(P<0.01),无断钉、断棒。结论选择性增加经伤椎椎弓根置钉短节段钉棒内固定治疗胸腰椎严重骨折,术中伤椎复位满意、术后固定牢固、脊柱稳定性好,有利于伤椎骨折愈合和患者早期功能锻炼与康复。     

人工椎体在胸腰椎病变中的应用

[目的]观察人工椎体在胸腰椎肿瘤、结核及骨折治疗中的外科疗效。[方法]对169例胸腰椎患者(其中包括64例肿瘤、66例结核、39例爆裂性骨折)的外科疗效进行回顾性分析。其中有57例伴有胸腰椎后凸畸形,术前Cobb s角27.1°~65.4°,平均(38.5±10.7)°。对所有患者进行病变椎体大部或完整切除,椎间撬拔撑开复位,可调式中空笼状钛合金人工椎体植骨替代,辅以前路椎体钉板(棒)系统或后路椎弓根钉系统行邻近椎节固定,Ⅰ期重建脊柱稳定性,观察术后局部疼痛缓解,脊髓神经功能恢复、脊柱椎节的稳定性及后凸畸形的矫治情况。[结果]随访12~46个月,平均32个月。所有患者术后疼痛缓解,肿瘤、结核病人术后局部均无复发,脊髓神经功能无加重损伤,73例患者脊髓神经功能得到不同程度恢复。术后影像学检查提示:脊柱内固定物在位,椎体序列恢复良好,椎间高度恢复。后凸畸形者术后矫正角度(31.6±8.3),°最后随访时矫正角度丢失(4.1±3.8)°。[结论]胸腰椎病椎切除、人工椎体植骨替代并内固定,能彻底减压、缓解疼痛,能有效重建脊柱稳定,恢复脊柱序列。     

多节段胸腰椎骨折的手术治疗

目的探讨胸腰椎多节段骨折手术方式。方法采用长节段椎弓根钉系统复位固定方法,恢复伤椎高度及脊柱生理弯曲,使后纵韧带复张,椎管间接减压或加用椎板切除减压,同时用神经剥离子将椎管前方骨块向前推压,治疗胸腰椎多节段骨折共17例。Ⅰ型（相邻型）12例,其中累及2个椎体10例,累及3个椎体2例;Ⅱ型（非相邻型）5例,损伤间隔1个正常椎体3例,间隔2个正常椎体2例。结果术后椎体高度、脊柱生理弧度明显恢复,经3个月～6年随访,复位后椎体高度无明显丢失,无断钉、断棒,F ranke l分级获1～3级恢复。结论多节段胸腰椎骨折影响脊柱稳定性,后路长节段椎弓根钉系统复位固定能够恢复脊柱稳定性及生理弧度,为改善神经功能提供条件。     

全脊椎整块切除术治疗胸腰椎肿瘤的疗效分析

目的探讨全脊椎整块切除术治疗胸腰椎肿瘤的临床疗效。方法回顾性分析自2012-03—2018-03采用全脊椎整块切除术治疗的11例胸腰椎肿瘤,观察术后肿瘤转移以及并发症情况。结果 11例均顺利完成手术并获得随访,随访时间1~7年,平均4.5年。术后9例疼痛明显好转,2例术后疼痛症状未缓解;1例因原发性肿瘤术后6个月死亡,1例因截瘫长期卧床导致术后18个月出现肺部感染死亡,1例术后3年发现相邻椎体肿瘤转移并术后5年出现钉棒断裂,再行Adena双头钉翻修取得良好效果;其余8例椎间融合良好,未出现钛笼塌陷、人工椎体移位、脊柱失稳、断钉、断棒等并发症。结论全脊椎整块切除术治疗胸腰椎肿瘤能提高患者生存率并改善脊柱局部疼痛症状,但无法避免肿瘤相邻椎体转移,可能出现植骨不愈合、钉棒断裂的现象,二次行Adena双头钉翻修术可取得良好效果。     

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.     

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.     

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.     

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.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.