快速成型模型佐助胸腰椎椎弓根置钉的研究

目的 探讨快速成型技术佐助胸腰椎椎弓根螺钉置入的准确性和可靠性.方法 将患者分成两组,快速成型组26例,传统手法置钉组26例,由同一位医师分别采用快速成型模型佐助置钉法和传统手法置钉进行胸腰椎椎弓根螺钉置入.术后CT扫描比较两种方法的置钉准确性.结果 快速成型模型佐助置钉156枚,其中3枚穿破皮质,成功率98.08％,绝对风险率0.64％;传统手法置钉121枚,11枚穿破皮质,成功率90.91％,绝对风险率4.13％.两组病例均未出现神经血管损伤并发症,快速成型佐助置钉法准确率明显高于传统手法置钉,安全性提高,差异具有统计学意义(P＜0.05).结论 快速成型模型佐助胸腰椎椎弓根置钉,可提高准确率和安全性,操作简单,符合个体化置钉,为胸腰椎椎弓根螺钉置入提供一种新方法.     

应用个体化椎弓根钉置入技术治疗胸腰椎骨折

目的观察个体化椎弓根钉置入技术治疗胸腰椎骨折的疗效。方法应用个体化椎弓根钉置入技术治疗胸腰椎骨折36例,即传统的定位方法、结合个体影像检查及术中感知体会手感来确定椎弓根钉道位置和方向。结果共144处椎弓根均在术中一次置钉成功,平均随访15个月。临床疗效满意。结论个体化椎弓根钉置入技术具有损伤小、操作精确可靠、置钉准确、一次成功率高等优点,易于被术者所掌握,术中可减少X线机的使用。     

Mimics软件三维建模确定椎弓根钉最佳置入点的临床应用

目的探讨Mimics软件三维建模确定椎弓根钉最佳置入点的临床应用,以提高一次性置入胸腰椎椎弓根钉的成功率。方法回顾性分析自2007-01—2014-05采用后路椎弓根钉内固定术治疗的各类胸腰椎骨折与疾病503例,将患者胸腰椎CT薄层扫描的Dicom数据导入Mimics软件进行三维重建,确定椎弓根钉置入的最佳通道平面,再确定椎弓根钉置入的最佳安全通道,最后确定椎弓根钉置入的最佳入点。结果 503例中共置入2 267枚椎弓根钉,一次性置入1 983枚,2次及2次以上置入284枚,一次性置入成功率达87.5%。采用Rao等的标准评估置钉的准确性:0级2 255枚,1级11枚,2级1枚,椎弓根置入的穿破发生率为0.5%,准确率达99.5%。结论术前利用Mimics软件三维建模寻找椎弓根钉最佳置入点,再指导术中置入椎弓根钉,一次性置入成功率、准确率较传统徒手置钉技术高。     

3D打印技术辅助椎弓根钉内固定治疗退行性腰椎侧弯的疗效分析

目的比较3D打印技术辅助椎弓根钉内固定与传统椎弓根钉内固定治疗退行性腰椎侧弯的临床疗效。方法回顾性分析自2017-01—2019-06诊治的37例退行性腰椎侧弯,22例采用较3D打印椎弓根定位-定向导板辅助椎弓根钉内固定术治疗(观察组),15例采用传统椎弓根钉内固定术治疗(对照组)。比较2组置钉时间、穿刺次数、末次随访置钉优良率与椎弓根钉松动率。结果37例均顺利完成手术且获得完整随访,随访时间3~6个月,平均4.5个月。观察组置钉时间较对照组短,穿刺次数较对照组少,末次随访时弓根钉置钉优良率高于对照组,椎弓根钉松动率低于对照组,差异有统计学意义(P<0.05)。结论3D打印椎弓根定位-定向导板辅助椎弓根钉内固定术治疗退行性腰椎侧弯可以提高椎弓根钉置入的准确度,节约置钉时间,减少术中椎弓根钉穿刺次数,提高置钉优良率,减少术后螺钉松动率。     

胸腰椎骨折椎弓根钉棒固定术后CT扫描MPR重建对置钉准确性的评价

目的 探讨螺旋CT扫描多平面重建技术(MPR)对胸腰椎骨折脱位椎弓根钉棒固定术后置钉准确性的评价.方法 对106例胸腰椎骨折脱位椎弓根钉棒固定术后患者进行置钉节段CT扫描并行MPR,评价置钉准确性.结果 106例共置入椎弓根钉601枚,优秀率83.2%,良好率15.1%,不良率1.7%.腰段置钉能获得更高准确率(P<0.01),置钉准确性与经验有关(P<0.01).结论 术后CT扫描并行MPR能够量化评价椎弓根钉的准确性,帮助临床医师提高置钉技术.     

两种腰椎椎弓根螺钉置入方法对比

目的比较腰椎两种椎弓根螺钉置入方法:Magerl法和人字嵴法。方法回顾性研究了2009-2011间行腰椎后路PLIF手术36例患者,其中16例(64枚椎弓根螺钉)为Magerl置钉法,20例(80枚椎弓根螺钉)为人字嵴置钉法。对比了两种置钉法二次置钉比率、置钉前切口显露时间、螺钉内倾角度、临床效果。结果两种置钉方法二次置钉比率、临床效果无统计学差异,两种置钉方法的置钉前切口显露时间、螺钉内倾角度存在统计学差异。结论腰椎椎弓根螺钉置入时,建议采用人字嵴置钉法。     

微创经皮椎弓根置钉内固定治疗胸腰椎压缩性骨折简

目的探讨微创经皮椎弓根置钉内固定治疗胸腰椎压缩性骨折的临床疗效。方法回顾性分析采用微创经皮椎弓根置钉内固定治疗的12例胸腰椎压缩性骨折的治疗及恢复情况。结果本组获随访12～24个月,患者恢复良好,未出现切口感染、神经副损伤,未出现断钉、断棒等并发症。结论微创经皮椎弓根置钉内固定治疗不伴有神经损伤的胸腰椎压缩性骨折．是一种有效的方法。     

O形臂导航辅助、C形臂辅助与常规徒手置入胸腰椎椎弓根螺钉准确性的定量比较

目的 比较O形臂导航辅助、C形臂辅助与常规徒手置入胸腰椎椎弓根螺钉的准确性。方法回顾性分析2015年2月-2018年12月应用椎弓根螺钉系统辅助融合治疗的129例胸腰椎置钉患者术后CT资料,其中胸腰段以下脊柱骨折41例,退行性疾病88例。常规开放手术直视下徒手置钉(徒手组)42例,C形臂辅助下经皮置钉(C形臂组)46例,开放手术O形臂导航辅助下置钉(O形臂组)41例。从螺钉长度、横断面进钉角度、矢状位进钉角度、椎弓根内侧壁、椎弓根上下壁、椎弓根外侧壁6个方面,采用10分制定量评估椎弓根螺钉置钉准确性,记录得分情况并进行组间比较。结果共置钉712枚。徒手组置钉准确性评分为7.79±0.93,满分比例为7.7%(16/208);C形臂组评分为9.13±0.59,满分比例为51.0%(101/198);O形臂组评分为9.27±0.65,满分比例为62.1%(190/306)。C形臂组和O形臂组置钉准确性评分差异无统计学意义(P > 0.05),但均高于徒手组,差异有统计学意义(P < 0.05)。结论 C形臂辅助经皮置钉和O形臂导航辅助置钉的准确性优于传统徒手置钉,C形臂辅助经皮置钉与O形臂导航辅助置钉准确性相当。     

经皮椎弓根钉内固定治疗胸腰椎压缩骨折的早期并发症及对策

目的 探讨经皮椎弓根钉内固定治疗胸腰椎压缩骨折的早期并发症并分析相关对策.方法 回顾性分析自2018-01-2020-06采用经皮椎弓根钉内固定治疗的94例胸腰椎骨折,比较术前与末次随时的疼痛VAS评分、ODI指数,记录相关并发症情况.结果 94例均顺利完成手术,共置入376枚螺钉,随访时间6～22个月,平均11.2个...     

椎弓根钉内固定联合椎体成形术治疗骨质疏松性胸腰椎爆裂骨折的三维有限元研究

目的 采用有限元方法比较骨质疏松性胸腰椎爆裂骨折在椎弓根钉内固定联合椎体成形术与椎弓根钉结合伤椎置钉内固定术后的生物力学稳定性.方法 建立骨质疏松性L1椎体爆裂骨折有限元模型,模拟短节段椎弓根钉联合椎体成形术(A组)以及椎弓根钉结合伤椎置钉内固定术(B组),比较2组前屈、后伸、侧屈、旋转载荷下L1椎体最大位移及内固定物...     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.