Medpor支架在耳廓再造和修复中的应用

目的：探讨Medpor（多孔高密度聚乙烯）支架在耳廓再造和畸形修复中的临床应用价值。方法：先天性小耳畸形和外伤后耳廓部分缺损的病例,采用带血管蒂的颞顶筋膜瓣覆盖Medpor支架,外用皮片移植,一期完成手术;烧伤后耳廓畸形的病例,采用扩张后的头皮瘢痕颞筋膜瓣带血管蒂转移,包裹Medpor支架二期完成修复。结果：共完成23例,前期5例有3例出现支架外露。后期18例手术效果满意,轮廓显现良好,无一例出现支架外露等其它严重并发症。结论：在耳廓再造和畸形修复中应用Medpor支架在临床上是一个可供选择的方法,但要强调各步骤的无张力原则和手术操作方法的相关细节,远期效果尚有待观察。     

应用Medpor支架Ⅰ期耳廓再造

目的：探讨采用Medpor支架行Ⅰ期耳廓再造新术式的临床效果。方法：采用耳廓Medpor支架，外包以筋膜瓣，再以中厚或全厚皮片移植覆盖，手术I期完成。结果：25例(25耳)皆一次成功，再造耳廓大小、外形及细微凹凸结构等，皆与健耳无显著性差异，无毛发生长，无皮肤坏死。结论：采用Medpor支架，覆以筋膜瓣和皮肤的全耳廓再造术式临床效果良好，手术方便。无需扩张皮瓣，免受取材及多次手术的痛苦，是一种较为理想的全耳廓再造方法。     

烧伤后全耳缺损Ⅰ期再造术

目的 探讨颞浅筋膜瓣翻转覆盖Medpor耳支架Ⅰ期全耳再造术在烧伤后全耳缺损修复中的应用效果和操作要点。方法 以Medpor为耳廓支架，掀起颞浅筋膜瓣，翻转包裹Medpor耳支架，筋膜表面游离植皮行Ⅰ期全耳再造术，共修复15例烧伤后全耳廓缺损患者。结果 15例患者再造耳廓外形满意。结论 颞浅筋膜瓣翻转包裹Medpor支架Ⅰ期全耳再造，具有手术时间短，操作步骤少，患者损伤小以及术后耳廓形态满意等优点，是一种适合于修复烧伤后全耳廓缺损畸形的手术方法。     

全耳廓再造术围手术期护理

目的:探讨先天性小耳畸形全耳廓再造术的围手术期护理方法。方法:30例先天性小耳畸形行全耳廓再造术,手术分两期,I期:设计颞顶筋膜瓣转移于残耳乳突区筋膜层下,与耳后筋膜皮瓣进行同期扩张;II期:将扩张耳后联合双层筋膜皮瓣转移包裹Medpor支架,行耳廓再造术。全程实施心理疏导,围手术期进行细致观察和护理。结果:本组再造全耳廓均I期愈合,无皮瓣坏死、感染等并发症发生。术后随访6个月至3年,再造耳廓形态良好,微细结构清晰,无一例支架外露。结论:扩张耳后双层筋膜皮瓣覆盖Medpor支架行全耳廓再造术,全程实施耐心细致的心理疏导,正确的围手术期护理是手术成功的关键。     

颞顶筋膜瓣与扩张皮瓣联合覆盖Medpor支架外耳再造术

目的探讨颞顶筋膜瓣与扩张皮瓣联合覆盖Medpor支架再造外耳的效果。方法手术分两期进行:一期手术在乳突区置入皮肤软组织扩张器,并定时注水扩张;第二期手术将扩张器取出并形成蒂在前的扩张皮瓣、掀起以颞浅血管为蒂的颞顶筋膜瓣,应用颞顶筋膜瓣和乳突区扩张皮瓣双重由里至外覆盖Medpor耳支架完成耳廓再造。结果临床应用22例,随访半年至2年半,无耳支架外露发生,再造的耳廓外形逼真,轮廓分明,肤色与周围正常皮肤一致。结论应用乳突区扩张皮瓣及颞顶筋膜瓣双层组织瓣包被Medpor耳支架,可以提高Medpor耳支架置入的安全性,避免发生外露,又不影响支架外形和轮廓的显现,再造耳表面皮肤的色泽与周围皮肤一致。     

扩张皮瓣联合Medpor耳支架全耳再造的临床研究(附8例报告)

目的:应用扩张皮瓣联合Medpor耳支架行全耳再造术,使耳再造成形逼真,立体感强,手术时间缩短,减少创伤,探讨如何防治Medpor耳支架外露。方法:先在耳缺损区埋置扩张器,定期注水,扩张两个月后,取出扩张器。将Medpor耳支架依照健侧耳廓为模型进行雕刻,塑形后,置入耳缺损区扩张皮瓣后面(耳后乳突区),耳支架后缘用颞浅筋膜瓣及耳后筋膜瓣包埋,植皮,全耳再造成功。结果:共完成此手术8例(男6例,女2例),耳成形良好,手术效果满意,扩张皮瓣覆盖组织与Medpor耳支架贴合紧密,且外形显现良好,耳廓形态逼真。其中仅1例耳支架后方绿豆大小外露,经局部修复痊愈。结论:扩张皮瓣联合Medpro耳支架全耳再造术,形态逼真,立体感强,耳廓形态稳定,远期不易变形,与使用肋软骨支架相比,无切取肋软骨之苦,且手术时间明显缩短。不足:MedPor耳支架价格昂贵,弹性较差,易外露。     

颞浅筋膜瓣结合头皮刃厚皮片移植修复耳廓再造术后软骨支架外露

目的:探讨应用颞浅筋膜瓣结合头皮刃厚皮片游离移植修复耳廓再造术后软骨支架外露的疗效。方法:9例行Nagata法耳廓再造术的患者,一期术后出现皮瓣缺血、坏死、软骨支架外露,清除坏死组织,切除失去活力的软骨,行颞浅筋膜瓣结合头皮刃厚皮片移植修复。结果:9例移植皮片全部成活,稍有色素沉着,再造耳廓形态逼真,轮廓清晰,效果满意。结论:颞浅筋膜瓣结合头皮刃厚皮片移植术是Nagata法耳廓再造过程中发生软骨支架外露后的一种较好的补救方法。     

应用Medpor支架Ⅰ期全耳再造术

目的 探讨Medpor支架在Ⅰ期全耳再造术中的应用.方法 自2004年6月至2008年12月,收治先天性小耳畸形患者18例,外伤性外耳缺损2例.均应用Medpor支架行Ⅰ期全耳再造.术中根据健侧耳模型雕刻Medpor支架,游离颢浅筋膜瓣覆盖耳支架,形成颞区的超薄皮瓣覆盖外耳前方的颞筋膜瓣表面,残余创面采用对侧耳后全厚皮片移植修复,腹部皮片修复健侧耳的供皮区.结果 20例耳再造术切口均Ⅰ期愈合.随访3～36个月,17例再造耳外形佳;1例术后半年因外伤致耳支架外露,采用对侧颞浅筋膜瓣吻合血管游离移植修复成功;2例外形欠佳.结论 Ⅰ期Medpor支架全耳再造术一次成形,创伤小,采用健侧耳后全厚皮肤移植再造耳颜色匹配.耳精细轮廓显露好.不足之处是弹性较差,价格较昂贵,一旦支架外露须再次手术修复.     

乳突区超量扩张皮瓣与颞浅筋膜瓣联合包裹多孔高密度聚乙烯支架全耳廓成形术

目的 探讨应用乳突区超量扩张皮瓣联合颞浅筋膜瓣包裹多孔高密度聚乙烯( Medpor)支架行全耳廓成形术的效果.方法 手术分三期进行:第Ⅰ期在乳突区置入皮肤软组织扩张器,并超量注水扩张;第Ⅱ期将扩张器取出并形成蒂在前的扩张皮瓣、掀起以颞浅血管为蒂的颞浅筋膜瓣,应用乳突区超量扩张皮瓣与颞浅筋膜瓣联合由里至外包裹Medpor耳支架完成全耳廓成形术,第Ⅲ期为残耳处理及耳垂再造.结果 临床应用12例,随访3个月至1年,耳支架外露发生1例,形成的耳廓外形逼真,轮廓分明,肤色与周围正常皮肤一致.结论 应用乳突区超量扩张皮瓣与颞浅筋膜瓣双层组织瓣联合包裹Medpor耳支架,可以获得更多的皮肤面积并提高Medpor耳支架置入的安全性,避免发生外露,又不影响支架外形和轮廓的显现,制作的耳廓表面皮肤的色泽与周围皮肤一致.     

预制扩张耳后乳突区复合筋膜皮瓣在全耳再造中的应用研究

目的：研究采用预制扩张耳后乳突区复合筋膜皮瓣行全耳廓再造的方法和效果。方法：手术分二期完成。I期手术：设计带有颞浅动静脉蒂的颞顶筋膜瓣,移植入残耳乳突区皮下腔穴,然后置入皮肤扩张器,与耳后皮瓣进行同时同步扩张I;I期手术：将预制扩张的耳后乳突区复合筋膜皮瓣掀起,覆盖于Medpor支架上,进行全耳廓再造术。结果：36例患者经6个月～3年的随访,再造耳廓外形逼真,立体感强,与周围皮肤颜色相同,微细结构清晰。结论：采用预制扩张的耳后乳突区复合筋膜皮瓣＋Medpor支架行全耳再造,具有创伤小,操作方便,效果满意。既可避免支架外露,又可避免取自体肋软骨增加的创伤和痛苦或肤色差异等优点,是目前全耳廓再造术较为理想的选择方法。     

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.     

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.     

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.