扩张器在修复瘢痕性秃发中的应用

目的探讨扩张器在头部瘢痕性秃发治疗中的应用效果。方法自2011年7月至2015年9月,应用扩张器扩张头皮修复23例瘢痕性秃发患者。一期手术:根据患者的秃发面积、部位及邻近区域毛发生长情况选择扩张器的容量及数量,将其埋置在秃发区周边正常毛发分布区,术后扩张器内注入生理盐水达到额定量。二期手术:切除瘢痕性秃发区皮肤组织,利用扩张的皮肤设计皮瓣来修复瘢痕切除后的创面。结果 18例患者经1次埋置1个或多个扩张器后,一次性修复瘢痕性秃发;5例患者因秃发面积较大经2次埋置扩张器后修复秃发区。扩张皮瓣易成活,切口瘢痕不明显,毛发分布均匀,密度可。结论采用扩张器修复大面积瘢痕性秃发,术后并发症较少,毛发分布均匀,生长良好,是修复较大面积瘢痕性秃发较理想的方法 。     

儿童头皮扩张修复瘢痕性秃发

目的探索儿童瘢痕性秃发的修复方法。方法１９８８年２月～１９９８年２月共收治儿童因烧伤后致瘢痕性秃发４５例，采用软组织扩张器行头皮扩张修复秃发区。介绍了儿童头皮扩张的特点、方法及其手术原则。结果术后效果满意，随访到５例，随访时间１～２年，除毛发生长方向改变外，扩张区和正常区头发无明显差异。结论在烧伤瘢痕性秃发的修复方法中，应首选软组织扩张术。     

应用头皮扩张术治疗小儿瘢痕性秃发

目的探讨小儿瘢痕性秃发的治疗方法.方法自1991年1月至2000年1月,共收治小儿瘢痕性秃发34例.本组均采用皮肤软组织扩张术,切口可据不同情况选择在瘢痕区、瘢痕与正常头皮交界区及正常头皮区,将扩张器植入剥离腔隙后,将帽状腱膜与其下骨膜固定数针,防止扩张器突入切口下而影响切口愈合,注水不宜过急,防止毛囊缺血坏死.Ⅱ期皮瓣转移时,可设计直接推进皮瓣、旋转易位皮瓣等.Ⅱ期手术时采用头皮止血带以减少失血.结果临床治疗34例,均获得近期满意效果.结论皮肤软组织扩张术是修复瘢痕性秃发的最佳方法.     

多只扩张器超量扩张修复大面积瘢痕性秃发

目的 探讨应用多只扩张器超量扩张头皮修复大面积瘢痕性秃发的临床效果.方法 Ⅰ期手术：根据秃发区的形状、面积大小,选择多只扩张器,在肿胀麻醉下,置于头部有发区帽状腱膜下,注射壶外置.超量扩张3～6个月,以获得额外有发头皮.Ⅱ期手术：将扩张器取出,切除瘢痕,将扩张后的有发头皮,采用滑行推进皮瓣、旋转皮瓣与易位皮瓣联合运用的手术方式,修复头皮秃发区.结果 23例患者术后秃发区修复效果良好,外观满意.结论 多只扩张器超量扩张可获得大量额外扩张头皮.合理设计皮瓣转移术,最大限度地提高了扩张皮肤的利用率,可修复大面积瘢痕性秃发,修复效果良好.     

应用皮肤软组织扩张器治疗瘢痕性秃发

目的探讨应用扩张器扩张皮肤软组织治疗瘢痕性秃发的效果。方法对12例瘢痕性秃发患者,Ⅰ期在邻近瘢痕的部位埋置1~3个扩张器,定期注水扩张,Ⅱ期行扩张皮瓣滑行、旋转修复创面。结果12例患者顺利完成二期手术,无明显的并发症发生。8例获0.5~1年随访,头发虽较稀疏,但生长良好。结论应用皮肤软组织扩张器修复瘢痕性秃发可获得良好效果。     

头皮扩张皮瓣移植分期修复跨发际的头面部大面积缺损

目的 总结应用头皮扩张皮瓣移植分期修复跨发际的头面部大面积缺损的经验和策略.方法 跨发际的头面部组织缺损5例,包括烧伤后头面部瘢痕并秃发3例、色素痣2例,采用皮肤扩张皮瓣移植分二期或三期修复.二期手术共2例,Ⅰ期于头部植入扩张器,同时施行脐旁皮瓣或肩胛皮瓣游离移植修复面部缺损;Ⅱ期行扩张头皮转移修复秃发区.三期手术3例,Ⅰ期于头部和肩背部同时植入扩张器,Ⅱ期行扩张头皮转移,Ⅲ期行预扩张颈浅血管蒂肩背皮瓣岛状转移修复面部.结果 5例皮瓣均全部成活.术后随访6～36个月,秃发区95％以上得到覆盖,面部外观良好. 结论 跨发际的头面部大面积缺损需修复头部秃发区和面部,应用头皮扩张术和皮瓣移植术的分期修复方法能获得良好的外观并缩短治疗周期.     

应用多处头皮扩张器修复瘢痕性秃发

目的:探讨头部多处皮肤扩张器修复瘢痕性秃发有效的方法.方法:采用多个皮肤扩张器进行头皮扩张,利用扩张皮瓣修复瘢痕性脱发.结果:修复瘢痕性秃发2 3例,扩张皮瓣全部成活,头皮瓣毛发分布均匀,随访半年至2年,效果满意.结论:该手术方法并发症发生率低,皮瓣张力小,毛发分布均匀,应为同类病例治疗的首选方法,值得推广.     

头皮扩张术治疗大面积瘢痕性秃发

目的:总结扩张术治疗大面积瘢痕性秃发的临床经验。方法:自2005年1月～2010年12月,应用皮肤软组织扩张术治疗因火焰烧伤、化学烧伤、撕脱伤愈合后遗留的大面积瘢痕性秃发,共18例。根据秃发及正常头皮的面积选择扩张器大小,将扩张器置入帽状腱膜下,放置引流管,3天后开始向扩张囊注液,注液总量据瘢痕秃发面积而定,一般修复1cm头皮,需要注水4.0～4.5ml。行扩张器取出、瘢痕秃发切除、头皮皮瓣转移术。结果:临床治疗18例大面积瘢痕性秃发病人,均取得满意效果。结论:皮肤软组织扩张术是修复大面积瘢痕性秃发的理想方法。     

头皮扩张术治疗大面积瘢痕性秃发

目的:总结扩张术治疗大面积瘢痕性秃发的临床经验。方法:自2005年1月～2010年12月,应用皮肤软组织扩张术治疗因火焰烧伤、化学烧伤、撕脱伤愈合后遗留的大面积瘢痕性秃发,共18例。根据秃发及正常头皮的面积选择扩张器大小,将扩张器置入帽状腱膜下,放置引流管,3天后开始向扩张囊注液,注液总量据瘢痕秃发面积而定,一般修复1cm头皮,需要注水4.0～4.5ml。行扩张器取出、瘢痕秃发切除、头皮皮瓣转移术。结果:临床治疗18例大面积瘢痕性秃发病人,均取得满意效果。结论:皮肤软组织扩张术是修复大面积瘢痕性秃发的理想方法。     

扩张术治疗瘢痕性秃发的手术设计

目的:探讨头部扩张器修复瘢痕性秃发手术设计的重要性.方法:采用AutoCAD软件测量秃发面积,用一个或多个扩张器进行头皮扩张,利用扩张皮瓣修复瘢痕性秃发.结果:修复瘢痕性秃发18例,扩张皮瓣全部成活,头皮瓣毛发分布均匀,随访半年～1年,效果满意.结论:该方法的手术设计,是手术成败的关键,扩张术修复瘢痕性秃发并发症发生率低,毛发分布均匀,是目前治疗此类疾病的首选方法,值得推广.     

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.     

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.