粉末冶金注射成型技术制备的新型血管内支架的动物应用研究

目的:通过动物实验评估一种新型血管内支架临床应用的可行性和安全性。方法:将30枚粉末冶金注射成型技术制备新型血管内支架分别植入30只实验犬主动脉内,术后CT血管造影了解其在主动脉内情况,并通过大体肉眼观察、光镜、电镜及免疫组化了解内术后不同时间支架表面新生内膜情况。结果:所有支架均成功植入实验犬主动脉内。术后支架通畅率100%,无支架移位、扭曲、断裂,无支架感染及血栓形成,管腔无狭窄或闭塞;支架的轴向回缩率均2%,径向回缩率均4%。术后1周,支架腔面迅速被一薄层半透明膜状结构覆盖;术后1个月,支架绝大部分表面可见与周围血管正常内膜相延续的新生内膜;术后2个月,新生内膜基本上完整覆盖整个支架腔面(98.83%),其厚度达到峰值(350.00μm);术后3~6个月,新生内膜厚度逐渐降低,管腔内径逐渐增大至植入前大小,最后新生内膜表面被单层完全成熟的内皮细胞覆盖。除术后1周外,其余时间点支架表面新生内膜组织中血管平滑肌细胞α-肌动蛋白染色均呈阳性,而各时间点支架腔面新生内膜组织中血管内皮生长因子染色均呈阳性。结论:粉末冶金注射成型技术制备的新型血管内支架植入后实验犬体内后形态结构稳定,并可迅速完成支架腔面内皮化,保持长期的通畅性,表现出良好的结构及理化稳定性和生物相容性,具有很好的临床应用前景。     

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目的 研究适合升主动脉夹层的支架型血管，探讨支架型血管放置的合理途径和方法；观察支架型血管放置后模型动物的病理生理变化及评估临床腔内治疗升主动脉夹层的可行性。方法 以国产镍钛记忆合金和人造血管为材料制作支架型血管系统，以犬制作升主动脉夹层动物模型，通过输送器在透视下将支架型血管经主动脉弓的头臂分支动脉释放在模型犬升主动脉适当的集团内，使支架型血管覆盖犬升主动脉夹层模型的内膜撕裂处，使夹层内口封闭，再经髂股动脉在降主动脉起始段放置合适的裸支架一枚，用来纠正或预防夹层在远处的产生和蔓延。结果 7例实验动物升主动脉夹层模型均相当于DeBakeyⅡ型；7实验动物中有5例经右锁骨下动脉，1例经头臂干动脉（预先行右颈总动脉、主动脉弓人造血管临时性转流），1例经左锁骨下动脉途径送入输送系统；支架型血管均准确迅速地旋转在升主动脉内，覆盖夹层内破口位置，即刻造影显示，无明确的主动脉瓣关闭不全影象，术后观察7例实验动物，2例由于失血过多等原因术后未能复苏外，另5例均于术后24h内复苏，3天内恢复正常饮食，观察期间内，神态、视听反射正常，四肢动脉搏动正常。术后第一周内尸检观察5只实验动物显示升主动脉内支架型血管完好，有1只支架型血管向远端移位约1cm，夹层内破口被支架型血管完好封闭。结论 此实验设计制作的国产支架型血管系统及选择的输送途径合理、可行；并主动脉夹层动物模型的制作有待进一步完善；选择合适的升主动脉夹层病例进行腔内修复治疗的临床应用应是安全、可行的，交给升主动脉夹层的临床治疗带来新的选择和希望。     

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目的 探讨支架型人工血管治疗主动脉夹层的临床效果。方法 2001年3月至2003年9月间，应用支架型人工血管治疗Ⅲ型夹层44例和Ⅰ型主动脉夹层1例。45例主动脉夹层共应用56个支架型人工血管行近侧内膜破口封堵，1例同时行远侧内膜破口手术关闭，1例远侧破口以分叉的支架型人工血管封闭。结果 所有病人均获得技术成功。围手术期死亡2例，1例术后12h后死于脑出血，1例术后10d死于假腔破裂；1例手术后半年死于细菌性心内膜炎。结论 支架型人工血管行Ⅲ型主动脉夹层和破口在降主动脉的Ⅰ型主动脉夹层破口封堵术较传统手术安全，其远期疗效需进一步观察。     

Stanford B型主动脉夹层术中主动脉内膜脱套的腔内处理策略

术中主动脉内膜脱套（AII）是胸主动脉腔内修复术（TEVAR）术中一种罕见但致命的并发症，补救处理难度大且易漏诊、误诊、误判，正确识别术中AII并快速有效地给予治疗是一大挑战。术中AII属于继发性AII，具体病因仍不明确，可能与手术操作原因和潜在的主动脉病变等原因相关。本文结合相关文献及临床诊疗经验，对主动脉夹层患者TEVAR术中AII的发生原因、分型、诊断评估要点及紧急腔内处置方法等进行介绍和探讨。首先，笔者提出基于脏器血流灌注的细化分型方案：即在原分型的基础上增加脏器分支缺血严重程度的评价，依据术中数字减影血管造影显示的脏器分支灌注情况细分为a、b两个亚型。新分型法的优势在于除了可以区分脏器缺血严重程度，还可用于指导腔内紧急处置策略。第二，对于疑诊术中AII的患者，需要进行术中详细造影确定分型。笔者建议分三步完成主动脉支架近端、支架远端造影及腹主动脉真腔内造影，这有助于明确近端锚定区的稳定性以及术中AII类型，确定灌注不良的脏器分支、严重程度及缺血阻塞类型，对下一步采取的补救措施至关重要。最后，腔内补救支架治疗效果良好且具备创伤小、术后恢复快等优势，已成为术中AII治疗的首选；腔内补救支架治疗应按照先近端再远端、先主干再分支的顺序进行。针对重建支架远端胸腹主动脉真腔血供，现有主流方案存在一定局限性，笔者推荐采用“两步法”方案重建主动脉真腔血供，该方案可以避免脱套内膜进一步向远端撕脱。     

主动脉腔内支架植入术后的螺旋CT血管成像评价

目的研究螺旋CT血管成像对主动脉腔内支架植入术后的评价意义。方法34例主动脉疾病患者（主动脉夹层16例、腹主动脉瘤18例）腔内支架植入术后行螺旋CT血管成像检查（其中多层螺旋CT检查21例，亚秒级螺旋CT检查13例），以容积再现（vR）、表面遮盖显示（SSD）、多平面重组（MPR）、最大密度投影（MIP）多种方式重建。对支架植入术后（支架的通畅、位置、形态，血栓的大小，术后合并症等）情况进行观察、评估。结果34例患者支架植入术后支架段主动脉均通畅，1例支架变形并右侧髂内动脉闭塞；33例支架外血栓形成，1例支架内血栓形成；8例术后假腔缩小，7例腹主动脉瘤者术后瘤体缩小；5例合并内漏。结论螺旋CT血管成像作为一种方便、快捷、无创的检查方法能够较客观地评价主动脉支架植入术后情况，在主动脉支架植入术随访中起着非常重要的作用。     

3D打印技术在辅助主动脉弓部开窗中的应用

目的 探讨3D打印技术辅助主动脉支架体外开窗在复杂主动脉弓部疾病全腔内治疗中的疗效。方法 回顾性分析2020年12月至2023年3月郑州大学第一附属医院利用3D打印主动脉模型指导主动脉弓部体外开窗联合支架植入治疗的25例复杂主动脉弓部病变患者（包括12例胸主动脉夹层和13例胸主动脉瘤）临床资料。术前利用CTA重建数据制备3D打印主动脉模型,确定手术方案后在3D打印模型的辅助下进行主动脉支架体外开窗并结合束径技术完成胸主动脉腔内修复术。结果 患者均成功完成体外开窗胸主动脉支架置入术。围术期及随访期内弓上分支血流通畅,无严重主动脉相关并发症、脑缺血事件及死亡事件发生。结论 对于解剖复杂的主动脉弓部疾病,利用3D打印模型精准指导主动脉支架体外开窗可提高支架开窗孔与弓上分支血管开口对位的准确率,使主动脉弓部疾病的全腔内治疗更安全有效。     

血管腔内治疗DeBakeyⅢ型动脉夹层动脉瘤（附15例报告）

目的 探讨带膜支架植入治疗降主动脉夹层动脉瘤的经验。方法 我科1999年5月至2005年12月为15例DeBakeyⅢ型的主动脉夹层动脉瘤患者作血管腔内带膜支架植入治疗，并分析其临床资料。结果 15例病人共用带膜支架22个，手术技术成功率100％。6例患者术中出现内漏，植入第二枚支架后漏口封闭。1例术后3月复查发现支架移位，再植入带膜支架后治愈。3例术后死亡，死因为心律失常，呼吸功能衰竭。治愈12例，平均随访20个月。所有患者内膜破裂口全部完全封闭，假腔内血栓形成无内漏，假腔均明显缩小。结论 带膜支架血管腔植入术治疗主动脉夹层动脉瘤具有良好的近期疗效，长期效果还有待进一步的研究。     

逆向烟囱技术和升主动脉包裹术治疗急性A型主动脉夹层

目的 :研究逆向烟囱技术的胸主动脉腔内修复术和升主动脉包裹术治疗急性A型主动脉夹层。方法 :从2013年2月至2017年4月,对17例传统外科治疗高风险的病人,应用逆向烟囱技术行胸主动脉腔内修复术。用潜望镜结构对主动脉弓上分支供血。如升主动脉扩张40 mm,则开胸行升主动脉包裹术以保护近端锚定区,适配主动脉支架。结果:所有病人均成功施行手术。其中16例行逆向烟囱技术保留主动脉分支腔内修复术,9例腔内修复外加行升主动脉包裹术,7例行弓上动脉旁路术。围手术期死亡率为12%(2/17)。未出现支架内血栓、脑血管意外或外周动脉栓塞等并发症。术后有创血压正常。所有病人随访期间血压均在正常范围。结论:通过尽量避免长时间体外循环的生理干扰,利用逆向烟囱技术腔内修复并选择性加强升主动脉支架锚定区,可提高急性A型主动脉夹层病人的抢救成功率。     

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目的 开展带膜支架腔内植入升主动脉治疗DeBakey Ⅰ型主动脉夹层的临床研究。方法 报告采用带膜支架腔内植入治愈DeBakey Ⅰ型主动脉夹层1例。结果 从左颈总动脉送入导丝和带膜支架至升主动脉封闭撕裂口。此前先建立左锁骨下动脉至左颈总动脉的内转流通道。二枚带膜支架重叠放置成功封闭升主动脉撕裂口，术后复查彩超示胸腹主动脉夹层消失，假腔内血栓形成，病人痊愈出院。结论 带膜支架腔内植入是治疗DeBakey Ⅰ型主动脉夹层的有效方法。通过颈总动脉送入支架和预先建立颈总动脉内转流通道可保证手术的成功进行。     

主动脉夹层动脉瘤腔内支架血管隔绝术的麻醉处理

腔内支架血管隔绝术是近10年开展的治疗主动脉瘤的新技术。与传统的开放式深低温停循环主动脉重建术相比，这种手术不仅具有创伤小、恢复快、并发症和致死率低等优点，而且使一些老年和合并全身严重并存疾病的病人有了新的救治机会。近年我院用介人性胸主动脉腔内支架血管隔绝术成功治疗了5例胸主动脉夹层动脉瘤病人，现报告如下。     

Intraoperative transoesophageal echocardiography as an adjuvant to fluoroscopy during endovascular thoracic aortic repair.

OBJECTIVES: To define the utility of intraoperative transeophageal echocardiography (TEE) during endovascular thoracic aortic repair. DESIGN: Retrospective study. MATERIALS: Five patients underwent six transluminal endovascular stent-graft procedures for repair of thoracic aortic disease. METHODS: After induction of anaesthesia, a multiplane or biplane TEE probe was placed to obtain views of the diseased aorta. Both transverse and longitudinal planes of the aortic arch and descending thoracic aortic segments were imaged. The aortic pathology was confirmed by TEE and the proximal and distal extents of the intrathoracic lesion were defined. Doppler and colour-flow imaging was used to identify flow patterns through the aorta before and after stent-graft deployment. RESULTS: Visualisation and confirmation of the aortic pathology by ultrasonography was accomplished in all patients. TEE was able to confirm proper placement of the endograft relative to the aortic lesion after deployment and was able to confirm exclusion of blood flow into the aneurysm sacs. CONCLUSIONS: TEE may facilitate repair by confirming aortic pathology, identifying endograft placement, assessment of the adequacy of aneurysm sack isolation, as well as dynamic intraoperative cardiac assessment.     

The importance of intraoperative transesophageal echocardiography in endovascular repair of thoracic aortic aneurysms

Endovascular repair of the aorta (EVAR) is a promising alternative to open repair. Transesophageal echocardiography (TEE) is a sensitive imaging modality for aortic disease. We reviewed our experience with TEE in thoracic EVAR. Seven patients underwent thoracic EVAR under general anesthesia. Intraoperative angiography and TEE were used to identify the extent of the aneurysm and guide placement of the stent. Doppler color flow was used to supplement angiography to detect flow within the aneurysmal sac after stent placement. The endograft was successfully deployed in six patients. Endoleak was identified by TEE in three patients and confirmed by angiography in two of them. EVAR was abandoned in one patient on the basis of TEE findings of extensive aortic dissection. We found TEE to be a valuable intraoperative tool for 1) identifying aortic pathology, 2) confirming that the guidewire is in the true lumen, 3) aiding stent graft positioning, and 4) supplementing angiography for detecting endoleaks. TEE can supplement information obtained by angiography to enhance the accuracy of EVAR and potentially improve outcomes. The anesthesiologist is ideally positioned to provide the endovascular team with vital information regarding stent positioning, endoleaks, and cardiac performance with a single imaging modality. IMPLICATIONS: Endovascular repair is an emerging alternative to open surgery for aortic aneurysms. We found transesophageal echocardiography to be a valuable imaging tool for guiding placement of the endograft, detecting leaks around the endograft, and supplementing information derived from angiography during endograft deployment.     

Usefulness of intraoperative transesophageal echocardiography in stent graft implantation for thoracic descending aorta

BACKGROUND: Stent graft implantation for thoracic descending aorta is a promising alternative to open repair. Transesophageal echocardiography (TEE) is a sensitive imaging modality for aortic disease. We reviewed our experience with TEE in stent graft implantation for thoracic descending aorta. METHOD: Five patients underwent stent graft implantation for thoracic descending aorta under general anesthesia. Intraoperative angiography and TEE were used to identify the extent of the aneurysm and the placement of the stent. RESULTS: TEE showed stent graft configuration and presence of leakage in all cases. In three cases, additional stent graft placement or bypass was performed. CONCLUSIONS: Useful information was obtained by TEE in enhancing the accuracy of stent graft positioning potentially improving outcomes. TEE may facilitate repair by confirming aortic pathology, identifying endograft placement, and assessing the adequacy of aneurysm sack isolation, presence of leakage, as well as dynamic intraoperative cardiac performance.     

Epicardial echocardiography: diagnostic utility for evaluating aortic valve disease during coronary surgery

Intraoperative epicardial echocardiography is commonly used to evaluate the ascending aorta for atheromatous disease before cannulation and cross clamping. In addition, it may serve as a cardiac imaging technique in patients where placement of a transesophageal echocardiography (TEE) probe is contraindicated, probe advancement is difficult, or a TEE probe is not available. We report a patient who was taken to the OR for coronary artery bypass grafting. Intraoperative TEE was planned to evaluate aortic valve function. However, attempts to place a TEE probe were abandoned due to high resistance on probe insertion. Epicardial echocardiography revealed previously undiagnosed aortic valve disease resulting in replacement of this valve.     

The use of transesophageal echocardiography in the evaluation of chest trauma.

Transesophageal echocardiography (TEE) has been used over the last 10 years (1982-1992) to study the heart and thoracic aorta. We set out to evaluate the diagnostic applications of TEE in patients with thoracic trauma. Specifically, TEE was performed on patients suspected of having either a cardiac contusion or an injury of the thoracic aorta. Fifty-eight patients admitted with thoracic trauma underwent TEE. Fifty of those patients suspected of having a cardiac contusion also underwent transthoracic echocardiography (TTE). The two diagnostic modalities were compared. In 21 of these patients a wide mediastinum was apparent on admission chest x-ray films. Nineteen of this latter group underwent thoracic angiography in addition to TEE. Two patients underwent post-mortem examination. Of the 50 patients undergoing both TEE and TTE, a cardiac contusion was detected by TEE in 26 patients. Transthoracic echocardiography detected only six contusions in this group. Of the 21 patients with a wide mediastinum, TEE detected three obvious aortic disruptions. These findings were confirmed in each case by angiography. In 16 cases TEE showed the aorta to be normal. This was confirmed on the angiogram in 14 cases and by autopsy in two cases. Transesophageal echocardiography revealed an aortic intimal irregularity distal to the left subclavian artery in two cases. The results of aortography were normal in these last two cases. As a diagnostic modality, TEE more accurately detected cardiac contusions than TTE (p less than 0.001) and was a very sensitive screening tool in the early evaluation of patients with a wide mediastinum.     

Diagnosis of progressive compression of the aortic true lumen with intraoperative transesophageal echocardiography during repair of dissection of thoracic aorta--a case report

We report an incident of progressive compression of the true lumen of aorta which happened immediately after cardiopulmonary bypass (CPB) and was diagnosed with intraoperative transesophageal echocardiography (TEE) in a patient undergoing an emergent repair of type A aortic dissection under femoral perfusion. During the CPB period, intraoperative TEE revealed gradual expansion of the false lumen which nearly obstructed the true lumen of the dissected aorta. The possible mechanism was related with distension of the false lumen by a dominant flow from retrograde femoral perfusion of CPB. With the application of intraoperative TEE, we could easily detect the hemodynamic changes of thoracic aorta and find the real causes so as to solve the perfusion abnormalities.     

Comparison of multiplane transesophageal echocardiography and contrast-enhanced helical CT in the diagnosis of blunt traumatic cardiovascular injuries

BACKGROUND: Multiplane transesophageal echocardiography (TEE) and helical computed tomography (CT) of the chest have been validated separately against aortography for the diagnosis of acute traumatic aortic injuries (ATAI). However, their respective diagnostic accuracy in identifying blunt traumatic cardiovascular lesions has not been compared. METHODS: During a 3-yr period, 110 consecutive patients with severe blunt chest trauma (age: 41 +/- 17 yr; injury severity score: 34 +/- 14) prospectively underwent TEE and chest CT as part of their initial evaluation. Results of both imaging methods were interpreted independently by experienced investigators and subsequently compared. All cases of subadventitial acute traumatic aortic injury were surgically confirmed. RESULTS: Seventeen patients had vascular injury and 11 had cardiac lesions. TEE and CT identified all subadventitial disruptions involving the aortic isthmus (n = 10) or the ascending aorta (n = 1) that necessitated surgical repair. In contrast, CT only depicted one disruption of the innominate artery. TEE detected injuries involving the intimal or medial layer, or both, of the aortic isthmus in four patients with apparently normal CT results who underwent successful conservative treatment. All cardiac injuries but two were identified only by TEE. CONCLUSIONS: In patients with severe blunt chest trauma, TEE and CT have similar diagnostic accuracy for the identification of surgical acute traumatic aortic injuy. TEE also allows the diagnosis of associated cardiac injuries and is more sensitive than CT for the identification of intimal or medial lesions of the thoracic aorta.     

Anesthetic management for distal aortic arch aneurysm stent grafting

A 76-year-old woman with thoracic aortic aneurysm involving distal aortic arch was scheduled for graft replacement from ascending to proximal aortic arch with endovascular stent graft to descending aorta. Surgical procedures were performed under median sternotomy with hypothermic systemic circulation arrest and selective cerebral perfusion. The stent graft composed of 30 mm Gianturco Z stent and 27.5 mm woven Dacron graft was introduced into the descending aorta under the guidance of transesophageal echocardiography (TEE) and fluoroscopy. Ascending and proximal aortic arch replacement was then performed with four branched woven Dacron graft. The aortic pathology was confirmed by TEE and the extent of the aneurysmal lesion was defined. TEE was also useful to find the dislodgement of the stent graft after deployment. This surgical technique, being less invasive than conventional thoracotomy, would be indicated for elderly patients with distal aortic arch aneurysm. TEE is the vital imaging technique for placement of the stent graft, as well as for intraoperative cardiac monitoring.     

Cardiovascular evaluation in blunt thoracic trauma using transesophageal echocardiography (TEE)

Blunt chest trauma can result in significant cardiothoracic injury, which can include cardiac contusion, aortic injury, and myocardial valvular injury. Nineteen patients with no prior history of cardiac abnormalities who sustained severe blunt chest trauma and had widening of the mediastinum on chest radiographs were prospectively evaluated using transesophageal echocardiography (TEE). In each instance TEE was performed without difficulty, excellent images were obtained of the aorta and heart, and no complications were noted. Abnormalities were seen in 12 (63%) patients, with hypokinetic regional wall motion consistent with cardiac contusion demonstrated in five (26%) patients. Tricuspid regurgitation was found in three (16%) patients, and aortic and mitral regurgitation in one (5%) patient each. Aortic wall hematomas were seen in two patients, one of whom had an intimal tear on aortography, and a pericardial effusion was seen in one patient with an aortic intimal tear confirmed angiographically. Thus TEE can be performed safely in the acute setting of patients sustaining severe blunt chest trauma and yield useful information with respect to cardiovascular function and the aorta.     

A case of intraoperative acute aortic dissection caused by cannulation into an axillary artery.

Severe atherosclerotic disease of the ascending aorta is one of the risk factors of dissection of the ascending aorta and cerebral embolism during cardiac operations with cardiopulmonary bypass. Aortic dissection is rare, but once it happens, the mortality rate is high. For the patient with severely atherosclerotic or strongly calcified aorta, we should avoid cannulation into the aorta or clamping of it. In this case, we experienced aortic dissection although we chose the arterial cannulations into the axillary arteries because of the strong calcification of the ascending aorta and the abdominal aorta. The dissection was caused by the cannulation into the axillary artery. Transesophageal echocardiography (TEE) showed the dissection during the operation and the ascending aorta was replaced soon. Early diagnosis and treatment saved the patient. This case showed the following points: 1) cannulation into an axillary artery is not always safe; 2) TEE is very useful to detect the complicated dissection during operation; 3) replacement of the ascending aorta alone can be one of the choices for the treatment of aortic dissection caused by cannulation into an axillary artery.