主动脉弓部腔内修复术后近端逆撕的预防与处理

<正>Stanford B型主动脉夹层(type B arotic dissection,TBAD)是一种威胁生命的急危重症,目前最常用的手术治疗方法是胸主动脉腔内修复术(thoracic endovascular aortic repair,TEVAR)^[1,2]。经过近20年的临床结果验证,TEVAR已取得理想的治疗效果,且效果更优于药物治疗和开放手术治疗的结果^[3.4]。结合其他腔内技术和复合手术技术时,TEVAR也可解决部分弓部病变;然而,该手术仍有自身缺陷,暂时没有摆脱术后严重并发症的困扰。     

主动脉夹层腔内治疗的中远期疗效和面临的问题

胸主动脉腔内修复术(thoracic endovascular aneurysm repair,TEVAR)最初仅被用于扩张性主动脉瘤的治疗,并获得满意的疗效。而TEVAR首次应用主动脉夹层则是于1999年分别由Dake等[1]和Nienaber等[2]报道,至今已超过10年。Dake对急性夹层TEVAR治疗的病人平均随访13个月,完全性     

胸主动脉腔内隔绝术后脊髓缺血的病因及防治研究进展

<正>自1994年Dake等^[1]应用腔内支架成功治疗胸降主动脉瘤以来，胸主动脉腔内隔绝术(thoracic endovascular aortic repair, TEVAR)彻底改变胸主动脉疾病的治疗方式，现TEVAR主要用于治疗胸主动脉瘤、胸主动脉夹层和胸主动脉损伤、胸主动脉壁内血肿、穿透性溃疡等^[2,3]。与开放修复相比，TEVAR不仅降低围手术期并发症发生率和病死率，而且远期疗效相似^[4],因此成为首选治疗方式。     

血管内超声在主动脉腔内治疗中的应用与进展

<正>胸主动脉腔内修复术(thoracic endovascular aortic repair,TEVAR)和腹主动脉腔内修复术(endovascular aortic repair,EVAR)因创伤小、并发症少等优点而在主动脉疾病治疗中被广泛使用且不断发展。与开放手术相比,TEVAR和EVAR的死亡率和再干预率较低^[1],但手术时仍存在动脉直径测量不准确、图像清晰程度不足等问题,影响术中判断。实践中对于传统DSA和CTA的改进并不能完全满足要求,而血管内超声(intravascular ultrasound,IVUS)作为从“另一个角度”进行检查的辅助手段,可弥补不足^[2,3]。     

主动脉弓上分支血管腔内重建的策略

<正>胸主动脉疾病包括胸主动脉瘤、胸主动脉夹层、壁间血肿、穿透性溃疡及外伤性主动脉损伤等,是血管外科领域常见的危重急症。胸主动脉腔内修复术(thoracic endovascular aortic repair,TEVAR)始于1994年^[1],已逐渐成为主动脉降部疾病的一线治疗方法^[2]。不过,主动脉升弓部疾病的治疗由于涉及到弓上分支动脉重建的问题,仍以开放手术为“金标准”^[3]。虽然结合了开放手术与腔内技术的去分支技术降低了侵入性^[4],但仍具有较高的并发症发生率和死亡率^[5]。     

烟囱技术在主动脉扩张性疾病腔内修复中的应用

腔内微创修复技术是目前主动脉扩张性疾病的重要治疗方法,包括腹主动脉瘤腔内修复术（Endovascular aneurysm repair,EVAR）和胸主动脉病变腔内修复术（Thoracic endovascular aortic repair,TEVAR）两类主要方式。     

胸主动脉夹层腔内修复术中封堵左锁骨下动脉的考量

正随着腔内技术的不断发展,胸主动脉腔内修复术(thoracic endovascular aortic repair,TEVAR)自1991年第一次被报道[1]以来,已逐渐成为治疗胸主动脉病变不可或缺的手段。目前大部分腔内耗材都要求TEVAR近端锚定区长度至少在15 mm,临床上常常通过覆盖主动脉弓的分支动脉来达到延长锚定区的目的[2],其中左锁骨下动脉是最常被累及的分支。有研究显示,大于40%的TEVAR累及主     

胸主动脉腔内修复术后常见并发症的防治

1994年,Dake实施了世界上首例胸主动脉腔内修复术（thoracic endovascular aortic repair,TEVAR）[1]。由于其创伤小、恢复快、死亡率低等优点,TEVAR已逐渐取代传统开胸手术,成为胸主动脉瘤和胸主动脉夹层的首选治疗方案[2]。然而,TEVAR术后的患者仍有可能发生内漏、逆行性主动脉夹层和截瘫等并发症,严重者可致死亡。因此,我们有必要对TEVAR术后并发症的种类和治疗方法进行探讨。     

浅析Stanford B型主动脉夹层胸主动脉腔内修复术后支架远端并发症

胸主动脉腔内修复术（TEVAR）现已逐渐成熟,成为临床治疗胸主动脉夹层的主要手段。腔内治疗拥有创口小,围术期死亡率低的优点,但长期随访结果相比开放手术缺少明显优势。TEVAR术后胸主动脉段虽得到处理,但腹主动脉及其分支在远期随访中会出现瘤样扩张、新发破口以及分支血管支配的器官缺血、功能不全等并发症。为减少该类并发症出现...     

真腔覆膜支架点状植入联合假腔内栓塞技术治疗腔内修复术后主动脉夹层动脉瘤

目的 ：回顾性评价真腔覆膜支架点状植入联合假腔内栓塞技术（spot stenting combined with false lumen endovascular occlusive repair,SS-FLEVOR）治疗腔内修复术后主动脉夹层动脉瘤的中期结果 。方法 ：收集2016年10月至2020年10月间采用SS-FLEVOR治疗胸主动脉腔内修复（thoracic endovascular aortic repair, TEVAR）术后主动脉夹层动脉瘤病人围术期及随访资料。分析病人手术前后胸主动脉、腹主动脉真腔最大径、假腔血栓化及内脏动脉分支支架通畅情况。结果：TEVAR术后远端瘤样扩张病人17例,平均年龄（54.5±14.5）岁,女3例。SS-FLEVOR手术均成功,平均手术时间（151.4±37.9） min。平均随访（24.9±20.7）个月。随访期间内脏动脉分支支架均通畅。胸主动脉和腹主动脉假腔均血栓化10例,胸主动脉假腔血栓化3例,胸主动脉和腹主动脉假腔仍存在部分血流4例。因假腔内血流逐渐减少且瘤体未增大,未予以二次干预。胸主动脉和腹主动脉真腔最大径均较术前增大。术前胸...     

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.