三种复合补片在污染环境下修补大鼠腹壁缺损的比较研究

目的观察聚丙交己内酯(polylactide-co-caprolactone,PLC)、透明质酸(hyaluronic acid,HA)、胶原蛋白与聚丙烯(polypropylene,PP)网片复合,在污染环境下修补大鼠腹壁缺损后粘连情况和修补效果,比较3种复合补片特点及一期修补可行性。方法成年雄性Wistar大鼠93只,体重150～250 g,随机分为3组(n=31):PP/PLC复合补片组(A组),PP/HA/PLC复合补片组(B组),PP/胶原蛋白/PLC复合补片组(C组)。各组取1只大鼠小肠制备污染源匀浆。其余大鼠制备直径约1 cm的腹壁疝模型后,根据分组将直径1.5 cm的复合补片缝合于腹壁缺损处。术后观察大鼠一般情况;于术后30、60、90 d处死大鼠,大体观察腹腔脏器粘连情况;切取补片及其周围组织进行组织学观察。结果术后10～70 d共6只大鼠死亡,其中A组2只,B组3只,C组1只;死亡原因均与补片修补无关。术后各时间点各组均见腹腔脏器与补片粘连,主要为肠管、网膜、肝。按照修正的Katada粘连评分方法,术后30、60 d各组间粘连评分比较,差异均无统计学意义(P>0.05);90 d时C组粘连评分显著低于A、B组(P<0.05)。组织学观察,术后30 d各组补片周围可见炎性细胞浸润,成纤维细胞出现且胶原分泌增加,可吸收材料残留;60 d时补片周围炎性细胞较前减少,成纤维细胞数量及胶原分泌较前增加,各组仅见PLC残留;90 d时成纤维细胞日趋成熟,可见胶原充填,腹腔面可见间皮层逐渐形成,各组残留PLC较前减少。结论 在污染环境下,PP/胶原蛋白/PLC复合补片在腹腔粘连及局部组织反应方面均优于PP/PLC及PP/HA/PLC复合补片,更适于一期修补大鼠腹壁缺损,但其远期效果及安全性仍待进一步确定。     

纳米仿生防粘连复合补片修复大鼠腹壁缺损中胶原合成功能的研究

目的评估纳米仿生、防粘连复合型疝补片修复腹壁疝的胶原蛋白合成功能的优劣,为临床提供实验依据。 方法选择成年SD雄性大鼠90只,随机分为3组：纳米仿生、防粘连复合型疝补片（nano-bionic and anti-adhesive compound hernia patch,NT）组,聚丙烯补片（polypropylene patch,PP）组及聚酯补片（polyester patch,PE）组,构建腹壁疝模型。根据分组将大小约3 cm× 2 cm的3组补片缝合于腹壁缺损处。术后观察大鼠一般情况,分别于术后4、6、8周处死大鼠各10只,大体观察腹腹壁手术区域胶原组织形成情况;剪取补片及其周围组织进行组织学观察,分析胶原蛋白表达情况,并进行Western bolt分析各组腹壁修复区域Ⅰ型胶原蛋白及Ⅲ型胶原蛋白表达量。 结果各组大鼠术后一般情况均良好,未出现死亡等不良事件;腹壁手术区域,NT组触感柔软,异物感较少,未见明显腹腔脏器突出,纤维组织生长情况良好;PP组触感较僵硬,皮下可见大量新生血管长入,异物感较重,纤维组织生长情况一般;PE组大鼠腹壁修复区触感僵硬,皮下可见较多新生血管长入,纤维组织生长较好。组织学观察：术后各个时间点,NT组修补效果优于PP、PE组,NT组Ⅰ型胶原表达更多,Ⅲ胶原表达更少,比例更加合理,纤维结构更加成熟稳定。组织蛋白含量：随着时间推移,术后各组Ⅰ型胶原蛋白随着时间进展逐步增加,而且NT组在各个时间点明显高于PP组及PE组,差异有统计学意义;术后6周及术后8周NT组的Ⅰ/Ⅲ型胶原蛋白比例基本保持在4∶1左右,较术后4周明显增加,而且在各个时间点上NT组均高于PP、PE组,差异有统计学意义。 结论在常规腹壁缺损无张力修补术过程中,NT补片在组织重构过程中比PP及PE补片更早形成成熟稳定的纤维结构,提供更加稳固的修复效果,适用于目前常规的腹壁疝修补,尤其是巨大腹壁缺损引起的腹壁疝。     

应用人工材料——Marlex网修补腹壁缺损

目的;总结应用人工材料聚丙烯网修补腹壁缺损。方法：通过手术修补腹壁缺损：其中切口疝１３例,腹股沟疝３２例,腹壁肿瘤１９例,结果：术后切口感染１例,皮下积液３例,其余病例切口Ⅰ期愈合,随诊４１例,未发现疝的复发和形成,结论：认为聚丙烯网是一种理想的修补腹壁缺损的材料。     

生物型补片与聚丙烯补片修补家猪腹壁缺损的对比研究

目的通过比较观察生物型补片与聚丙烯补片修补家猪腹壁缺损后的组织病理学变化，进一步探讨此生物型补片在疝修补治疗中应用的可行性。方法分别于10只小猪的腹直肌左右侧腹壁制成-6cm×4cm的肌肉腱膜层缺损区。左侧缺损区用生物型补片进行手术修补，右侧用聚丙烯补片修补。分别于修补术后1、3、6、12个月取材行大体观察及组织病理学检查。结果小猪在修补术后均未发生腹壁切口疝。术后1年内，聚丙烯侧的补片结构不能被吸收而始终存在，局部的炎症反应较明显；生物补片侧在各期的局部炎症反应轻于聚丙烯侧，且补片成分变性吸收，逐步由结缔组织所替代。结论生物型补片的组织相容性较好，能诱导组织再生，实现对缺损的再生性修复，有可能成为一种比较理想的疝修补材料。     

应用合成与生物材料补片修补腹壁切口疝的经验体会

应用各种补片材料进行腹壁疝修补已成为疝外科的一个基本手段,尤其是腹壁切口疝,组织缝合修补手术失败率高达70%,应用补片修补腹壁切口疝可以降低术后复发率已被公认.随着人工材料的植入、手术适应证的扩大和腹壁疝手术量的增多,和补片相关的各种手术并发症问题逐渐引起重视.     

新型纳米仿生补片修复兔腹壁疝模型的实验研究

目的探讨新型纳米仿生补片在腹壁疝修补治疗中应用的可行性。方法选择新西兰大白兔25只,通过建立兔腹壁肌肉缺损区的疝模型,术后1周观察动物腹壁突出情况。采用一期修补的方式,使用新型纳米仿生补片无张力修补腹壁疝,观察术后切口感染、疝复发等并发症。取出包括网片在内的腹壁全层,做组织学观察和免疫组化研究。结果未发现手术及麻醉并发症,也未发现补片感染的案例,所有修补模型未发现复发。新型纳米补片几乎不引起腹腔粘连,术后6个月内新型纳米仿生补片变性吸收,胶原纤维增生,被结缔组织所替代,逐渐形成一致密结缔组织层。结论我们可以通过切除腹壁2 cm×3 cm全层腹壁组织结构获得稳定的动物疝模型,此新型纳米仿生补片可能是一种较为理想的腹外疝修补材料。     

游离上极腹直肌前鞘修补TRAM腹壁供区缺损——自体组织制作补片的尝试

目的 探索在带蒂横行腹直肌肌皮瓣（TRAM）手术中尝试运用自体组织制作补片——游离上极腹直肌前鞘以修补腹壁供区缺损的临床效果。方法 将TRAM手术的供区用自体游离上极腹直前鞘进行修补,而非人工补片。应用自体腹直肌前鞘进行修复与传统的人工补片修补手术用时相同,但为患者节省了相应的人工补片费用。结果 手术后,腹部供区恢复良好。术后6个月并未出现腹壁膨隆、腹壁疝和脐周坏死等并发症,患者对结果满意。结论 使用自体组织制作补片,不增加手术时间与难度,可为修补腹壁供区缺损提供一种新的方法。     

自体组织移植修补腹壁巨大缺损

腹壁缺损可由创伤或腹壁肿瘤切除造成的原发性大面积腹壁缺失,也可由手术切口或肠造口造成疝,以及疝修补失败、合成材料修补术后感染、复发等继发形成[1,2],其发生率约为2%～11%[3]。如缺损大(巨大切口疝:疝环最大距离≥10cm),可用自体组织移植或人工合成材料修补,目前临床上广     

猪切口疝模型的建立及使用生物型补片修补的研究

目的 建立小猪切口疝模型并探讨生物型疝补片在切口疝修补治疗中应用的可行性.方法 通过在小猪上腹部制作一个肌肉筋膜层缺损区的方法 建立切口疝模型,分别采用二期修补和一期修补的方式,使用生物型补片无张力修补切口疝.观察术后切口感染、疝复发等并发症及补片组织的病理学变化.结果 术后1周时可获得典型的切口疝模型;一期修补组未发生切口疝,二期修补组6只小猪成功,2只因切口感染、补片排出而失败.术后6个月内观察,生物补片的胶原变性吸收,逐渐被结缔组织所替代,大体上逐渐形成一致密结缔组织层并自体腱膜化.结论 本研究所采用的切口疝模型制作方法 成功率高、可重复性好.用生物型疝补片修补小猪切口疝可行,并预示着此生物补片可能是一种较为理想的腹外疝修补材料.     

一种新型注射型骨修复材料对犬桡骨骨缺损修复的实验研究

目的 探讨以纤维蛋白胶(fibrin sealant,FS)为载体复合牛骨形态发生蛋白(bBMP)和碱性成纤维细胞生长因子(bFGF)的注射型骨修复材料修复犬桡骨节段性缺损的效果. 方法 12只家犬随机分为实验组和对照组,每组6只.12只成年健康家犬右侧桡骨中上段造成2.0 cm缺损,制成犬桡骨2.0 cm骨缺损实验模型,然后严密缝合皮下组织及皮肤.对照组和实验组分别经切口周围正常皮肤注射FS和FS bFGF bBMP到骨缺损处,术后4、8、16、24周进行放射学检查,术后24周取标本进行组织学和骨密度检查,研究其成骨效应. 结果 ①影像学:实验组术后4周缺损区有密度较低的骨痂形成;术后24周,皮质完全连接,髓腔再通.对照组术后24周内缺损区均无骨痂生长,骨缺损未得到修复.②骨密度测定:术后24周时实验组的骨密度(456.33±13.74)mg/cm2显著高于健侧(433.33±6.77)mg/cm2(t=2.57,P=0.00)及对照组(0mg/cm2)的骨密度.③组织形态学:术后24周实验组新生皮质骨十分致密,骨皮质连接完整,髓腔完全再通;对照组无新生骨形成,缺损处完全为结缔组织修复. 结论 以FS为载体复合bBMP和bFGF的注射型骨修复材料具有高效的骨修复能力,对家犬的骨缺损有良好的修复效果.     

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.     

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.     

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.