诱发电位应用于降主动脉手术的研究

目的 通过比较单纯阻断与左心转流技术在胸降主动脉手术中对脊髓缺血损伤的影响,评价在主动脉手术中应用皮质体感诱发电位监测脊髓缺血的可行性,.方法 12头小型猪随机分为单纯阻断和左心转流组.均采用左胸肋间入路开胸,在左无名动脉以远阻断降主动脉.术中使用诱发电位监测仪连续监测皮质体感诱发电位(CSEP),监测脊髓功能变化.术后每日记录动物行为学评分.术后7 d处死动物,观察脊髓组织细胞的超微结构.结果 单纯阻断组中2头动物后肢轻瘫,其余后肢均截瘫.左心转流组动物恢复顺利,无截瘫发生.单纯阻断组CSEP波幅降低达50%以上,潜伏期延长10%以上,变化与行为学评分一致.阻断平面以下脊髓的超微结构显示,单纯阻断组脊髓髓鞘板层结构破坏严重,线粒体肿胀,破坏.左心转流组与阻断平面以上脊髓比较,变化不明显.结论 在动物模型中,CSEP对脊髓缺血状况的监测及时有效.     

81例胸腹主动脉置换术脊髓保护中肋间动脉重建技术的应用

目的 总结肋间动脉重建在全胸腹主动脉置换术中的脊髓保护作用.方法 2003年8月至2010年8月,81例CrawfordⅡ型胸腹主动脉瘤患者,男61例,女20例;平均年龄(39.4±10.32)岁.采用4分支人工血管进行全胸腹主动脉置换.手术经胸腹联合切口,使用深低温、分段停循环技术,对胸(T)6 ～12肋间动脉和腰(L)1、2动脉进行动脉管法原位重建.腹腔干、肠系膜上动脉、右肾动脉做成一血管片与人工血管主干吻合,左肾动脉或单独与1根分支血管吻合,或与上述3支血管一起吻合在人工血管主干上,双侧髂动脉与人工血管两分支行端端吻合.结果 患者均获随访.术后早期死亡6例;脊髓损伤3例,其中2例截瘫,1例下肢轻瘫,均治愈.出院后20、23、30个月后各有1例患者死亡;术后随访中12例患者重建肋间动脉闭塞,均无截瘫发生,其中2例马方综合征患者重建肋间动脉并发假性动脉瘤.患者平均生存(54.22±3.03)个月(95％ CI:44.37 ～59.90个月),1年生存率为92.37％,2年生存率为89.02％,5年生存率为85.54％.结论 肋间动脉重建对降低术后急性脊髓损伤效果确切,远期生存良好.     

主动脉手术的脊髓保护

脊髓损伤是胸主动脉手术后的严重并发症,影响手术后脊髓并发症发生的因素包括手术过程中脊髓缺血的时间及程度、主动脉修复后脊髓血运的重建状况、多种生化因素、缺血-再灌注损伤等。目前主动脉手术中脊髓的保护手段有:提高手术技术和改进手术方法;增加脊髓的血液供应,包括提供机械性动力的血液灌注和动脉分流,脑脊液分流;利用低温降低脊髓的代谢率;应用药物防止脊髓缺血-再灌注损伤。现就脊髓的血液循环特点、脊髓损伤的发生机制和脊髓保护的最新进展进行综述。     

单纯无名动脉灌注的主动脉弓置换术21例

目的 探讨主动脉弓置换术中使用单纯无名动脉灌注进行脑保护的安全性和有效性.方法 2004年1月至2007年7月,2l例主动脉弓置换者使用单纯无名动脉灌注技术进行脑保护,男19例,女2例;年龄29-72岁,平均(46.5±11.4)岁.A型(Stanford分型)主动脉夹层19例,其中7例合并主动脉瓣关闭不全;升主动脉及主动脉弓真性动脉瘤伴降主动脉受累2例.所有病例均在深低温、使用单纯无名动脉选择性脑灌注下进行升主动脉、主动脉弓置换+降主动脉覆膜支架置入术.同时行Benlall手术6例,David手术1例.结果 升主动脉阻断(109.6.4-29.6)min;体外循环(186.7±56.2)min;最低鼻咽温(19.O±3.3)℃;选择性脑灌注时间(38.3.4-11.5)Ⅲ.m,流量每分钟(6.8±2.6)ml,l‘g.术后无中枢神经系统并发症.呼吸机辅助(38.6±29.O)h.1例因低心排输出量综合征于术后第5 d死亡.术后随访2-45个月,平均(24.0±12.5)个月,无死亡及心脑血管意外发生.结论 深低温、单纯无名动脉选择性脑灌注下行主动脉弓置换是安全、有效的.     

常温非体外循环下全胸腹主动脉替换术

目的 总结常温非体外循环下全胸腹主动脉替换术(total thoracoabdominal aortic aneurysm repair,tTAAAR)的手术方式和早期治疗效果.方法 2009年2月至2010年12月,共完成41例全胸腹主动脉替换术,其中27例CrawfordⅡ型胸腹主动脉瘤(thoracoabdominal aortic aneurysm,TAAA)患者接受常温非体外循环tTAAAR治疗.男18例,女9例;平均年龄(41.85 ±10.11)岁.手术经左侧胸腹联合切口、腹膜外入路,常温非体外循环下建立降主动脉→双侧髂动脉旁路循环,然后采用分段阻断法,重建T6～T12肋间动脉及内脏血管.结果 所有患者均完成手术,降主动脉阻断(13.78 ±3.77) min.脊髓缺血( 19.19±3.93) min,内脏缺血(25.19 ±5.88) min.1例患者术中死亡,其余患者均生存.术后永久性脊髓损伤2例,呼吸系统并发症3例.结论 中国全胸腹主动脉瘤患者应早期积极治疗,常温非体外循环下的全胸腹主动脉替换术是一种安全、有效的治疗策略.     

主动脉阻断期间脊髓缺血的保护

胸腹主动脉瘤修复手术有5～30%的病人并发截瘫,这取决于主动脉置换的长度。该并发症是由继发于主动脉阻断的脊髓缺血所致。小部分病人麻醉醒后神经功能正常仅在1～5天后发生迟发性截瘫。虽有提示术后低血压或肋间动脉血栓形成是迟发性神经功能缺失的可能原因,但其病理生理先前未曾阐明。作者     

胸腹主动脉瘤术中脊髓功能的保护

胸腹主动脉瘤是危害中老年患者的严重的主动脉疾病 ,临床上虽不常见 ,但自然死亡率极高。最有效的治疗手段是外科手术 ,然而术中阻断降主动脉时间过长 ( >3 0分钟 )或没有恢复主要肋间动脉或腰动脉供血 ,就会发生脊髓缺血性损伤导致脊髓神经系统并发症 ,以截瘫最为严重 ,其发生率为 0 .2 %～2 0 % ,甚至达 40 % [1] 。对于这一迄今尚未完全解决的严重并发症 ,目前脊髓功能保护方法繁多 ,但对主动脉阻断范围广、时间长者 ,现有的保护方法效果仍不理想 ,须进一步探讨。1　发病机理　　目前关于术后截瘫的原因已在器官和细胞水平的很多动物实验…     

不同手术方式行全胸腹主动脉替换的临床研究

目的 比较手术治疗的效果,探讨不同手术方式行全胸腹主动脉替换术的适应证和具体手术方法,明确常温非体外循环下全胸腹主动脉替换的可行性和安全性.方法 2009年2月到2011年5月,46例CrawfordⅡ型胸腹主动脉瘤(thoracoabdominal aortic aneurysm,TAAA)患者行全胸腹主动脉替换术(total thoracoabdominal aortic aneurysm repair,tTAAAR).根据术式不同,分为深低温停循环tTAAAR(A)组15例和常温非体外循环tTAAAR(B)组31例.计数资料采用精确概率的x2检验和计数资料经正态性检验后采用t检验等统计学方法,比较了患者的术前、术中和术后ICU治疗情况以及围术期病死率、并发症发生率等.结果 A组和B组术后早期死亡(26.67％对3.20％,P=0.033)和一过性脑功能障碍发生率(33.30％对3.30％,P=0.018)差异有统计学意义.两组手术时间(P＜0.0001)、降主动脉阻断时间(P ＜0.0001),输注红细胞(P=0.013)差异亦有统计学意义.术前情况、内脏缺血时间、脊髓缺血时间、ICU治疗时间、带气管插管时间、脊髓损伤、肾功能不全等差异无统计学意义,P＞0.05.结论 常温非体外循环全胸腹主动脉替换术安全、可靠.适应证为可在常温下建立降主动脉到髂动脉旁路循环的胸腹主动脉动脉瘤.肋间动脉重建是重要的脊髓保护手段.     

一期全主动脉置换术治疗广泛主动脉瘤样病变早中期结果

目的 总结一期全主动脉置换术治疗广泛主动脉瘤样病变的早、中期结果和单中心临床经验.方法 2004年2月至2011年2月,21例广泛主动脉瘤样病变的患者进行了一期全主动脉或次全主动脉置换术.男16例,女5例;年龄(34±9)岁.病因为高血压10例,马方综合征9例,其他1例;其中20例为主动脉夹层.手术采用深低温停循环顺行脑灌注技术,分段阻断病变主动脉,通过胸部正中切口,应用四分支人工血管依次置换升主动脉、主动脉弓及三支头臂血管.通过胸腹联合切口经腹膜后入路,应用另一四分支人工血管置换全胸腹主动脉至髂动脉分支处.术中对胸(T)6-12肋间动脉和腰(L)1、2动脉行动脉管法原位重建,分别将腹腔干、肠系膜上动脉、左右肾动脉和双侧髂动脉与人工血管主干和分支吻合.结果 无术中死亡.术后早期1例死于肾功能衰竭,2例发生脑梗塞但无脊髓损伤所致截瘫和下肢轻瘫.随访18 -84个月,出院20例患者均生存.3例重建肋间动脉的动脉管发生闭塞,但无截瘫症状.结论 一期全主动脉置换术是治疗广泛主动脉病变安全而有效的方法,患者早、中期生存情况良好.     

胸部降主动脉瘤体外循环方法探讨

目的探讨胸部降主动脉瘤手术中采用不同体外循环方法的临床效果及对大脑的保护作用。方法分析2001年1月至2008年12月我院术前经磁共振成像(MRI)确诊为胸部降主动脉瘤65例患者的临床资料,男56例,女9例;年龄15～71岁,平均年龄48.1岁;病程6d～4个月(19.0±6.5d)。术前临床诊断为DeBakeyⅢ型夹层41例,马凡综合征手术后并存或并发Ⅲ型夹层9例,假性动脉瘤7例,真性动脉瘤8例。施行人工血管补片修补降主动脉破口2例,动脉瘤切除人工血管置换术63例,其中降主动脉置换术+肋间动脉移植术18例。结果 65例患者采用的体外循环方法包括左心转流13例,全心转流12例,深低温停循环(DHCA)全身逆行灌注(TBRP)30例,改良上下半身分离体外循环10例。体外循环时间51～212min,DHCA时间18～75min,逆行灌注时间18～73min,上半身停循环时间21～31min,下半身停循环时间39～67min。所有患者无1例手术死亡;未发生大脑并发症,无1例瘫痪并发症发生。术后早期死亡2例,均死于无尿性肾功能衰竭。结论根据胸部降主动脉瘤发生的解剖部位和范围选择不同的体外循环方法 ,能够取得良好的效果;选择的标准是要有利于手术操作,器官保护效果确实,操作方法简单。     

Reversal of delayed-onset paraplegia with thrombectomy of an interposed graft for the intercostal artery after thoracic descending aortic aneurysm repair

A 78-year-old woman who had previously undergone prosthetic graft replacement of the total aortic arch was admitted to repair a chronic expanding type IIIb dissecting aneurysm. Firstly the patient’s abdominal aorta was replaced with a prosthetic graft without any complications, then the thoracic descending aorta was repaired five months later. Surgery for the thoracic descending aorta was performed with distal perfusion, cerebrospinal fluid drainage, somatosensory evoked potential (SEP) monitoring and reimplantation of three pairs of intercostal arteries. During surgery, SEP showed no significant changes, and the patient awoke without paraplegia three hours after the surgery. However, she developed bilateral complete paraplegia eight hours after the surgery. Reexploration demonstrated thrombo-occlusion of the sidearm graft for reimplantation of the Th10 intercostal artery. After thrombectomy of the sidearm graft, there was gradual neurological recovery and the patient was ambulatory when discharged. Quick treatment to restore the spinal cord blood supply promoted recovery from paraplegia.     

Selective intercostal arterial perfusion during thoracoabdominal aortic aneurysm surgery

BACKGROUND: This clinical study evaluated changes in motor evoked potentials (MEP) elicited by direct cerebral cortical stimulation and evoked spinal cord potentials (ESCPs) elicited by direct spinal cord stimulation during selective intercostal arterial perfusion for thoracoabdominal aortic aneurysm (TAAA) repair. We also determined the efficacy of this perfusion method for prevention of paraplegia. METHODS: Two kinds of ESCPs and MEPs were monitored during the prosthetic replacement step for TAAA surgeries. We performed selective intercostal arterial perfusion from the T7 intercostal artery to the L1 intercostal artery through a small piece of Dacron graft while monitoring spinal cord potentials in five cases of TAAA. RESULTS: The MEP amplitude decreased after clamping the aorta but quickly recovered after selective perfusion of intercostal arteries. Other spinal cord potentials did not change during the reconstruction of intercostal arteries. Postoperative paraplegia or parapalesis did not occur in any of the patients. CONCLUSIONS: Monitoring of MEPs during selective intercostal arterial perfusion was a useful adjunct to prevent postoperative paraplegia in TAAA surgery.     

Spinal Cord Protection During Thoracoabdominal Aneurysm Repair

Spinal cord injury after thoracoabdominal aortic surgery remains a devastating and unpredictable complication, caused by clamping of the thoracoabdominal aorta, resulting in exclusion of blood flow in critical and essential intercostal arteries. Various protective methods against spinal cord ischemia have been proposed and performed clinically. These include preoperative spinal angiography, distal aortic perfusion, hypothermia, reattachment of the intercostal artery, cerebrospinal fluid drainage, administration of neuroprotective agents, and monitoring of somatosensory and motor-evoked potentials. The information to date suggests that multimodality approaches should be used to prevent spinal cord injury after thoracic and thoracoabdominal aneurysm repair.     

A case report of a patient who developed hemiparaplegia with multiple cerebral infarction during thoracoabdominal aortic aneurysm repair

To protect the spinal cord during thoracoabdominal aortic aneurysm repair, motor evoked potentials (MEP) monitoring and cerebrospinal fluid drainage are often employed. Herein, we report a case, where intraoperative diminishment of motor evoked potentials was accompanied by multiple cerebral infarction. A 63-year-old man underwent elective surgery for both thoracoabdominal aortic aneurysm and abdominal aortic aneurysm. He had a past history of cerebral infarction, resulting in Wernicke aphasia but no paralysis. Preoperative magnetic resonance angiography and echocardiography revealed occlusion of the intercostal and lumbar arteries, mild aortic regurgitation, and atherosclerotic lesions at the aortic arch as well as descending aorta. Anesthesia and muscular relaxation were maintained with fentanyl, propofol, and continuous administration of vecuronium at 0.5 mg x kg(-1) x h(-1). The thoracoabdominal aortic aneurysm was repaired under distal aortic perfusion with femorofemoral bypass. After terminating the bypass, we found that the MEP at the lower limb had disappeared. Although we reconstructed intercostal arteries under mild hypothermia and partial bypass, the amplitude of MEP remained very low. Suspecting spinal cord ischemia, we performed cerebrospinal fluid drainage immediately after the operation. On the postoperative day 4, when we stopped the cerebrospinal fluid drainage and propofol administration, his level of consciousness was poor and brain CT revealed multiple cerebral infarction. On the postoperative day 30, he was discharged from an intensive care unit with complications of hemiplagia and paraplegia. Although cerebrospinal fluid drainage may be recommended to protect spinal cord during thoracoabdominal aortic aneurysm repair, we should consider performing brain CT to exclude a risk of brain herniation secondary to cerebrospinal fluid drainage if there is a possibility of cerebral incidents.     

Open surgery of thoracoabdominal aortic aneurysm

Postoperative paraplegia is a serious complication of reconstructive surgery on the thoracoabdominal or descending thoracic aorta, and the major cause is thought to be spinal cord ischemia during and after the procedure. Due to advances in anesthetic and surgical techniques, the incidence of intractable neurological complications has declined, but the rate of paraplegia or paraparesis is still within the range of 5-16%. Many methods have been devised to prevent this complication, such as 1) distal perfusion, 2) reimplantation of segmental arteries, 3) detection of the Adamkiewicz artery, 4) hypothermia, 5) cerebrospinal fluid drainage, 6) multisegmental aortic clamping, 7) motor-evoked potential monitoring, 8) epidural perfusion cooling, and 9) selective perfusion of the intercostal arteries and they can be utilized in combination.     

How to prevent spinal cord injury during endovascular repair of thoracic aortic disease

The incidence of spinal cord injury in thoracic endovascular aortic repair (TEVAR) has been 3–5 % from recent major papers where sacrifice of the critical intercostal arteries is inevitable by a stent graft. Hemodynamic stability, which depends on a network of blood vessels around the cord is most important not only during but also after stent-graft deployment. High risk factors of spinal cord injury during endovascular aortic repair are (1) coverage of the left subclavian artery, (2) extensive coverage of long segments of the thoracic aorta, (3) prior downstream aortic repair, (4) compromising important intercostal (T8–L1), vertebral, pelvic and hypogastric collaterals, and (5) shaggy aorta. Preoperative, intraoperative, and postoperative managements have been required to prevent spinal cord injury with TEVAR. For imaging assessment of blood supply to spinal cord including Adamkiewicz artery, prophylactic cerebrospinal fluid drainage is mandatory, and monitoring motor-evoked potential is recommended for high risk factors of spinal cord injury. Mean arterial pressure should be maintained over 90 mmHg after stent-graft placement for a while to prevent delayed spinal cord ischemia in high-risk patients of spinal cord ischemia. Finally, because spinal cord injury during TEVAR is not rare and negligible, perioperative care during TEVAR should be strictly performed according to the protocol proposed by each cardiovascular team.     

Novel strategy for thoracoabdomianl aortic aneurysm repair; intraoperative selective perfusion of the Adamkiewicz artery

We report our method for delineating the Adamkiewicz artery using multidetector row computed tomography (MDCT) with selective perfusion using a distal perfusion cannula that is clinically available for off-pump coronary artery bypass (OPCAB). The tip of a distal perfusion catheter (Medtronic Quickflow, Minneapolis) designed for OPCAB was applicable for selective perfusion of the segmental arteries. The femoro-femoral venoarterial bypass was branched off into selective perfusion of the segmental arteries, using an independent roller pump and heat exchanger. Our method of visualization of the Adamkiewicz artery was MDCT scanning with injection of contrast medium directly into the proximal descending aorta: namely, "CT during aortography". Lower descending aorta to abdominal aorta (the range involving the aneurysm) was scanned in a cephalad-to-caudal direction using a detector collimation of 4 x 1.25 mm with a table speed of 9.4 mm/sec, pitch of 6, and image thickness of 1.25 mm. All images were reviewed on a workstation to investigate the continuity between the Adamkiewicz artery and its proximal segmental artery with paging, mulitplanar reformation and curved planar reformation. Distal perfusion cannulae of 2.0 mm in diameter were inserted into the respective intercostal arteries. 4-0 polyethylene sutures were placed to tourniquet the catheters. Segmental arteries were perfused with total flow of approximately 80 ml/min at a circuit pressure of 120 mmHg. Reattachment of the ninth intercostal arteries related to the Adamkiewicz artery was carried out. A total of 6 consecutive 6 patients with thoracoabdominal aortic aneurysm (TAAA) have undergone graft replacement by the methods described, since April 2002. All patients survived surgery without any neurological complications. This method is expected to minimize the ischemic time of the spinal cord and attenuate the reperfusion injury.     

Total graft replacement of the thoracoabdominal aorta with reconstruction of visceral branches, intercostal and lumbar arteries in expanding chronic dissecting aneurysms of the thoracoabdominal aorta

Four patients with expanding chronic dissecting thoracoabdominal aneurysm underwent total replacement of the thoracoabdominal aorta with reconstruction of all visceral branches, intercostal and lumbar arteries with the aid of femoro-femoral bypass. During aortic cross-clamping, selective celiac and both renal arteries perfusion was performed to prevent the organ ischemia. Somatosensory evoked potentials monitoring or spinal cord evoked potentials monitoring was also performed to detect the spinal cord ischemia. Surgical technique employed in this series was direct anastomosis of onlay patch graft to the normal true lumen from which visceral branches and intercostal and lumbar arteries arise. The celiac artery and left renal artery arise from the false lumen in some cases were reconstructed with graft interposition or direct anastomosis to an opening made in the onlay patch graft. All patients survived the operation, and are leading normal life late in the postoperative period except one who developed partial paraplegia. Total graft replacement of the thoracoabdominal aorta may be a valid technique for the treatment of expanding aneurysms of the dissecting thoracoabdominal aorta.     

马方综合征主动脉根部手术后远端主动脉病变再次外科治疗

目的 总结马方综合征主动脉根部手术后远端主动脉病变的再次外科治疗结果,探讨相关治疗策略。方法 2000年1月至2010年1月,28例马方综合征主动脉根部手术后远端主动脉病变患者进行再次手术治疗。其中男20例,女8例;年龄23～52岁,平均(38.5±8.7)岁。首次手术包括Bentall手术24例,David手术4例。Stanford A型夹层8例,主动脉根部瘤20例。再次手术包括：胸腹主动脉置换术10例,全主动脉弓置换及支架象鼻术7例,胸降主动脉置换术6例,全主动脉置换术2例,全主动脉弓置换术2例,部分主动脉弓置换术1例。两次手术间隔1 ～12年,平均(6.43 ±3.07)年。结果 术后发生神经系统并发症4例(17％),包括脑卒中1例,截瘫1例,单侧下肢一过性运动障碍2例。二次开胸止血3例,急性肾功能衰竭接受血滤治疗1例。3例因术后呼吸机辅助时间延迟接受气管切开术。术后全部随访,随访时间10～ 118个月,平均(40.8±29.5)个月。住院死亡2例(7.1％),术后1年、5年实际生存率分别为(94.5±1.3)％、(90.6±1.4)％。结论 马方综合征行主动脉根部手术后因远端主动脉病变再次外科治疗临床结果满意。对于患主动脉A型夹层的马方综合征,首次手术即采用积极的主动脉全弓置换及象鼻手术更好。     

Prevention of spinal cord ischemia after cross-clamping of the thoracic aorta--monitoring of spinal cord perfusion pressure and somatosensory evoked potentials

The pressure difference between the mean distal aortic pressure (MDAP) and the cerebrospinal fluid pressure (CSFP), defined as the spinal cord perfusion pressure (SCPP), as well as somatosensory evoked potentials (SEP) were monitored intraoperatively to detect and prevent intraoperative spinal cord ischemia in 24 patients who required cross-clamping of the descending thoracic aorta. A temporary axillo-femoral shunt, utilizing a 10 mm woven Dacron tube graft, was employed in 10 patients and partial cardiopulmonary bypass was employed in fourteen. Ischemic SEP changes were seen in six patients. Two patients, whose SCPPs were 32 and 35 mmHg, showed a complete loss of SEP and subsequently developed paraplegia. In the other four cases, increase of the MDAP and/or withdrawal of cerebrospinal fluid were performed to increase the SCPP to more than 60 mmHg when ischemic SEP changes occurred. The SEP gradually recovered in two of these cases. The ischemic SEP changes seen in one patient, who had the longest aortic cross-clamping time, (175 minutes) returned to normal immediately after unclamping. In another case, who had a thoracoabdominal aortic aneurysm, the intercostal arteries were reimplanted since the ischemic SEP changes did not revert. These four patients recovered without any neurological deficit. In the other 18 cases without ischemic SEP change, SCPP was kept at more than 40 mmHg during aortic cross-clamping. We conclude that the SCPP should be maintained at more than 40 mmHg during aortic occlusion, and increased to more than 60 mmHg when ischemic SEP changes occur, by increasing MDAP and/or withdrawing cerebrospinal fluid in order to prevent postoperative paraplegia.