下颌角截骨移植隆颏术

目的探讨利用自体下颌角截骨块同期移植隆颏的手术方法。方法经口腔入路,利用下颌角肥大截骨术的下颌角骨块,塑形为适合颏部的形状,Ⅰ期移植于颏部,且以钛钉坚强内固定。结果本组35例患者行双侧下颌角截骨+下颌骨外板磨削术+自体下颌角移植隆颏术,术后移植骨愈合良好,颏部形态符合美学标准。结论下颌角截骨Ⅰ期移植隆颏术,操作方法简单,预期效果可靠,移植骨块与颏部解剖结合,无排异反应。     

自体下颌骨隆颏术

目的　探讨颏部美容术的一种新方法。方法　口内入路 ,将双侧下颌角骨质或下颌骨外板取出 ,根据颏部具体情况及患者主观意愿 ,将骨块修整成适当形状 ,移植于颏部 ,以钛钉或钛板作坚强内固定。结果　 2 0 0 0年 1月～ 2 0 0 3年 1月我们共收治 30例患者 ,其中 2 0例行双侧下颌角截骨 自体下颌骨移植隆颏术 ,10例行双侧下颌骨外板截骨 自体下颌骨移植隆颏术。术后伤口愈合良好 ,颏部形态满意。结论　自体下颌骨移植隆颏 ,无排异等不良反应 ,移植骨块与颏部能牢固愈合 ,术后效果满意 ,是一种理想的颏部美容手术方法。     

自体下颌角骨质游离移植隆颏术的实验和临床研究

目的:研究应用自体下颌角区骨质游离移植隆颏术的可行性。方法:分为两部分,第一部分动物实验:将小型猪的下颌角截除,并用截除的下颌角骨质移植到颏部,用钛钉固定,术后用三维CT进行效果评定。第二部分,临床应用,在46例应用双侧下颌角截骨术治疗方脸畸形的同时,应用下颌角骨质进行隆颏术,术后随访,观察治疗效果。结果:动物实验中游离移植的骨质完全被吸收。临床病人中73.9%的患者吸收率达到50%以上。结论:通过动物实验和临床应用观察,我们认为临床中应用下颌角截除的自体骨游离移植隆颏术需要谨慎实施。     

自体下颌角骨移植隆颏术

目的:介绍自体下颌角骨隆颏术。方法:在下颌角肥大患者截除下颌角后,根据颏部形态要求,将下颌角骨打磨塑形,用钛钉固定于颏部。结果:自2000年来共完成61例自体下颌角骨移植隆颏术,术后随访3月～2年,形态满意60例,不满意1例。结论:下颌角肥大伴有小颏畸形患者行下颌角骨移植隆颏是一举两得的好方法。     

双侧下颌角突出合并小颏畸形的治疗

目的 提高双侧下颌角突出伴有小颏畸形的手术治疗效果。方法 用口内入路行双侧下颌角连续弧线截骨术，同时行颏部水平骨前徒延长、小夹板坚强内固定、自体下颌角骨质断端间植骨术，不作咬肌部分切除手术。结果 1996－1999年共收治20例，术后下面部宽短畸形明显改善。咬肌虽未行部分切除，但术后随着咬肌附着点的上移、肌张力降低而发生部分萎缩，下颌角部曲线圆滑，形态自然。结论 双侧下颌角突出伴有严重小颏者，只有同时行双侧下颌角有和颏部水平截骨整形，才能达到全面矫治畸形的目的。下颌角连续弧线截骨术截骨设计灵活、向上可达下颌升支后缘、向下可延续至下颌体下缘，截骨量大；一次完成；截央后的下颌角更加圆滑自然；结合颏部截骨整 术，不仅提高了术后的整体效果，而且可利用截除的下颌角骨质充填于颏部水平截骨断端间，可以保证骨质的愈合，一举两得。     

切除肥大下颌角之骨块用于颏成形术

目的：探求隆颏术新方法。方法：12例手术均在切除肥大下颌角的同期,选择较大一侧被截除的下颌角骨块,塑形后植入颏部,行颏成形术,钛针固定。结果：12例术后随访3个月－3年,美容效果良好。结论：该手术利用自体骨移植无排斥反应,并发症少。易塑形,美容效果理想。     

下颌截骨整体塑形术

目的　为使不同类型“方形脸”者达到下颌截骨术后下颌整体形态的协调美观。方法根据不同类型的下颌角肥大 ,在下颌骨截骨的基础上联合应用下颌缘截骨、下颌骨半环形截骨以及下颌自体骨隆颏等综合手术方法改善下颌整体形态。结果　自 1996年以来共收治 312例 ,其中下颌角联合下颌缘截骨 2 0 0例 ,单纯下颌缘截骨 2 3例 ,下颌骨半环形截骨 15例 ,下颏修尖 9例 ,下颌自体骨隆颏 32例。对其中 15 0例随访 1～ 12个月 ,满意率 97%。结论　综合的下颌截骨方法可使方形脸术后下颌整体效果协调美观。     

下颌骨分区截骨术重塑面下部轮廓

目的将下颌骨以美学观为准分为升支下区、下领角区、下颌体区、颏区。通过分区截骨术，矫正面下部前份、中份、后份宽大的不良形态。方法结合下颌骨外板矢状劈开和下颌骨角部和下颌骨下缘的全层截骨术和隆颏术，对下颌骨角部、体部和颏部进行分别截骨重塑，同时矫正面下部正面和侧面的欠美外形。结果于2003年5月至2005年8月，共开展此类手术23例，下颌角、升支下部、体部截骨18例，颏部截骨5例。隆颏术的方式有固体硅胶假体置入12例，膨化聚四氟乙烯假体置入3例，自体下颌骨外板移植5例。术后外形均得到明显改善，外观满意，未发生颏神经断裂并发症，3例口唇麻木于1～3个月后自然恢复。结论对下颌骨进行分区截骨可以更全面的矫正面下部过宽，重塑面下部的轮廓以美化面型。     

双侧颧骨过高合并小颏畸形的治疗

目的：探讨同时解决颧骨过高和颏部短小的一种新方法。方法：口内入路，行L形颧骨截骨降低术，同时行颏部水平截骨术，将颧部骨质移植于颏部，以钛板钛钉做坚强内固定。结果：2000年1月～2007年1月，共18例患者采用如上方法治疗。术后颏部形态满意。结论：L形颧骨截骨降低术同时行颏部水平截骨自体移植隆颏术是一种理想的美容手术方法。     

自体骨屑颏部填充动物模型的动态观察

目的 设计及建立自体骨屑颏部填充的动物模型,寻求一种创伤小、简便易行的隆颏手术方法,为临床应用提供实验资料和理论依据.方法 同窝10个月龄杂种犬4只,自下颌角区切口,分离咬肌,暴露下颌角,切取部分下颌角区下颌骨,用电动打磨机磨碎成骨屑,移植至下颏部下颌骨处,建立动物模型.术后观察动物进食活动.并于术后2、4、8、12周取材,行电镜检查,观察骨屑与颏部下颌骨融合的情况.结果 手术后动物进食活动仍正常.术后2、4、8、12周,电镜检奁显示,自体骨屑通过吸收、血管及其周围组织长人,新生骨从颏部下颌骨逐渐向内生长替代移植骨屑,骨屑完成支架作用.结论 自体骨屑颏部填充,损伤小,与颏部下颌骨融合良好,术后塑形好,成骨愈合期加快,塑形稳定,无排斥,不影响实验动物的进食活动. 区切口,分离咬肌,暴露下颌角,切取部分下颌角区下颌骨,用电动打磨机磨碎成骨屑,移植至下颏部下颌骨处,建立动物模型.术后观察动物进食活动.并于术后2、4、8、12周取材,行电镜检查,观察骨屑与颏部下颌骨融合的情况.结果 手术后动物进食活动仍正常.术后2、4、8、12周,电镜检查显示,自体骨屑通过吸收、血管及其周围组织长人,新生骨从颏部下颌骨逐渐向内生长替 移植骨屑,骨屑完成支架作用.结论 自体骨屑颏部填充,损伤小,与颏部下颌骨融合良好,术后塑形好,成骨愈合期加快,塑形稳定,无排斥,不影响实验动物的进食活动. 区切口,分离咬肌,暴露下颌角,切取部分下颌角区下颌骨,用电动打     

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.     

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.     

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.