主动脉缩窄的介入治疗

   主动脉缩窄是一种较常见的先天性心脏畸形,1760年由Morgagni尸检时首次发现,并被定义为降主动脉近段管腔局限性狭窄[1]。占各类先天性心脏病的5% ~8%,男女发病比例为3~5∶1。CoA病理生理学改变主要表现为血流动力学异常,左心系统至体动脉血流梗阻,导致缩窄近心端血压升高,左心室继发肥厚劳损,至左心衰竭,缩窄以远血压减低,侧枝循环建立。临床上,如收缩期上下肢之间动脉压力阶差>20 mm Hg(1 mmHg=0.133 kPa),结合相应的影像学改变即可诊断为先天性主动脉缩窄[2-3]。根据CoA发生的部位和范围CoA分为导管前型(婴儿型)和导管后型(成人型)。前者约占10%,缩窄位于动脉导管之前,下半身靠动脉导管供血,有交界性紫绀,除动脉导管常合并其它心内畸形,如不及时手术,多于婴儿期死亡。后者约占90%,缩窄位于动脉导管韧带远侧,动脉导管多数闭合,较少合并心内畸形,如不矫治,平均死亡年龄30岁左右[3]。
   CoA的传统治疗方法: 自从1944年Clarence Crafoord 首次采用“主动脉缩窄段切除端-端吻合术”取得成功后[4],外科手术成为CoA,特别是合并主动脉弓发育不全及心内畸形等患者的首选治疗方法。随着外科手术技术不断改进,包括使用主动脉补片成形术,人工血管植入术、人工血管转流术等,病人的预后不断改善,死亡率由最初的31%降至2.7% [5-7]。但外科手术难度大、并发症相对较多,包括术后再狭窄(3.6% ~33.0%)、动脉瘤形成(13.0%)、术后高血压(8.3% ~43.0%)、喉反神经损伤、膈神经损伤、乳糜胸、感染、缩窄切除后综合症、截瘫等[6-9]。
   CoA的介入治疗方法:自20世纪80年代以来,介入治疗作为治疗主动脉缩窄的一种有效、安全、简便的手段开始崭露头角,并得以迅速推广。从最初的球囊扩张术发展到球囊扩张式血管内裸支架置入术及目前的覆膜支架置入术,介入治疗技术不断改善。
   经皮球囊扩张术:
   1982年经皮球囊扩张术用于治疗主动脉缩窄取得成功[10],由于其方法简单,死亡率低,自此成为主动脉缩窄的一种主要治疗方法。其治疗原理在于[11-14]球囊扩张血管时,是通过使缩窄段血管内膜及中膜局限性撕裂和过度伸展,从而使管腔扩大的,达到治疗效果。但有研究显示这种撕裂可达中膜深层,甚至外膜层,造成狭窄段主动脉壁薄弱,从而引起夹层及动脉瘤。另外,因球囊扩张术后主动脉壁不可避免的有不同程度的弹性回缩[11],以致术后短期再缩窄率较高,在一定程度上妨碍了其在原发主动脉缩窄中的应用。根据文献:对于新生儿及婴儿原发主动脉缩窄,球囊扩张术后再狭窄率达39%~83%,不作为常规治疗方法,仅用于婴儿型CoA 的姑息治疗。对于儿童及成人导管后型CoA,球囊扩张术有显著的即刻疗效,86%-94%的病人术后缩窄有效缓解,术后再缩窄和继发动脉瘤者分别为5%~25%,2%~20%,但这些继发主动脉瘤多为非进展性动脉瘤,需外科手术处理的继发主动脉瘤<1%,可作为外科治疗主动脉缩窄的一种替代手段[11-23]。
   血管支架植入术:
   近几十年,血管内支架植入术被用于外周血管及冠状动脉狭窄的治疗,取得了广泛的成功,血管内支架对血管壁提供了持续的支撑,可以有效降低血管弹性回缩,减少术后再狭窄的发生率,支架能增强动脉壁的强度,有助于减少动脉瘤及夹层的发生,这些理论上的优点使支架很快用于主动脉缩窄的治疗中。1991年,O’Laughlin 等第一次成功使用球囊扩张血管内支架治疗主动脉缩窄取得成功[24]。在随后的十余年,裸支架置入术获得了显著的短期及中期疗效,跨缩窄处收缩压差均明显降低。其术后并发症的发生率亦低于单球囊扩张术[25-28]。
   针对裸支架、及球囊扩张术可引起夹层、动脉瘤甚至动脉破裂等并发症,一些研究将支架与聚四氟乙烯结合生产出一种覆膜支架,可有效的避免上述并发症的发生。1999年Gunn J等第一次使用覆膜支架治疗一例合并动脉瘤的CoA取得成功[29]。2001年Cheatham首次使用覆膜Cheatham–Platinum (CP)支架成功治疗一例重度CoA和一例主动脉弓离断[30]。随后的一系列研究进一步显示CoA覆膜支架植入术近期疗效显著,与裸支架相比,其安全性更高,可用于重度CoA,对于一些复杂的CoA,包括外科术后再狭窄、炎症引起的长段狭窄、裸支架植入术后急性主动脉破裂均可获得良好疗效,特别是伴有动脉导管未闭或动脉瘤时,该支架在解决CoA的同时,可一次性隔绝动脉导管及动脉瘤[31-35]。
主动脉缩窄血管内支架植入术的适应证包括:单纯的主动脉峡部缩窄、主动脉弓及峡部发育不良(狭窄段血管直径与横膈处降主动脉直径之比<0.6)、主动脉缩窄行球囊扩张术后或外科术后再缩窄[36-39]。多用于10岁以上青少年(主动脉直径接近成人水平)及成人患者,是外科手术的一种替代治疗方法。对于低龄患者,主动脉支架植入术后,由于机体生长发育,会造成主动脉支架段相对狭窄,较少使用。
   支架的并发症包括:急性主动脉破裂、广泛的夹层、股动脉的损伤或血栓栓塞、支架移位断裂等[40-49]。这些并发症的发生几率很低,主要见于独立的个案报道,特别是覆膜支架的使用,进一步减少了夹层、动脉瘤等并发症的发生。与球囊扩张术相比,血管内支架植入术最主要的一个缺点是它需要相对较大的鞘,以将球囊支架输送并通过主动脉缩窄处,因此增加了股动脉损伤及血栓栓塞的风险。此外,主动脉植入支架的生物反应包括:血栓形成、内膜增生和再狭窄。实验证明支架植入后,其表面会有薄层新生内膜覆盖,避免局部血栓形成。但如内膜过度增生,则导致支架处管腔再狭窄[50]。Suarez等随访48例主动脉缩窄支架治疗术后的患者2-3年,只有3名患者由于内膜过度增生,发生再狭窄。这一结果表明,由于内膜过度增生导致主动脉再缩窄,是很少见的[41]。主动脉支架术后再缩窄多是由于支架段管径不能随机体生长发育增宽而导致的相对狭窄。
   覆膜支架可能闭塞主动脉供应脊髓的侧枝血管,从而增加了截瘫的风险性。目前,在一个大样本的胸主动脉瘤支架植入术的研究中,截瘫的发病率达3.6%[33],提示理论上存在有这种少见但十分严重的并发症的可能性。供应脊髓的侧枝血管多起源于主动脉峡部以下,所以对峡部以下的主动脉缩窄使用覆膜支架应慎重[36]。
支架及其推送系统的技术进步
   目前,广泛使用的NuMED CP支架硬度及弹性进一步增强,扩张时支架的短缩率明显减低,另外该支架的可扩张直径及长度范围更广泛,确保生长发育期的儿童及青少年患者植入的支架可扩张达到成人主动脉直径水平;对于缩窄段较长的患者,减少了多个支架的使用[44,46]。NuMED CP支架包括球囊扩张式和自膨式支架,前者坚硬度高,可以有效抵抗缩窄段血管的弹性回缩力,故治疗主动脉缩窄多选择该支架。自膨式支架运用较少,但有报道指出二者对主动脉缩窄的疗效及安全性相似,而自膨式支架植入操作简便,对主动脉壁的适应性好,所需输送鞘小,更适宜年龄较小的患者[46]。
正在研究中的生物降解支架虽然尚未在儿科心脏病领域中推广使用,但目前对生物降解支架的研究表明,它不仅能保护受损内膜,限制其过度增生,还能逐渐自动降解,消除金属支架不随生长发育而增大的不足之处,在该支架植入1年后的动物试验中[50],支架已被完全内膜化,无血栓栓塞,仅有轻微的内膜增生,无明显的管腔狭窄。生物降解支架的发展,使支架可以应用于更年幼的患者。
   双球囊导管(Balloon-In-Balloon,BIB catheter)的应用,减少了支架植入过程中的支架移位及支架边缘的张开,从而降低了血管/球囊的损伤几率。现有的支架及推送器为8—12F[36],由于输送鞘的尺寸,婴儿及小的儿童多被排除在支架治疗的适应症之外。即使是年龄较大的病人,该尺寸范围的鞘也会导致股动脉损伤。因此,输送系统的技术改进无疑会扩大支架治疗主动脉缩窄的适应范围。2009 Bruckheimer及其同事提出分次扩张的方法,即先使用小球囊以减小输送系统的尺寸,再以较大球囊扩张支架,他们将支架经9F的输送系统成功置入一体重为21Kg的儿童患者,但这一方法增加了支架脱载移位的可能[51]。2010年,Bruckheimer又报道了2个机构使用新型PTFE覆膜自膨式支架(Advanta V12)治疗CoA的早期经验,支架输送系统缩小至8F,并成功用于一5岁体重20Kg的儿童[52],显示主动脉缩窄覆膜支架置入术有望突破年龄限制,用于较小儿童。
尽管支架植入术获得了显著的近中期疗效,但在主动脉内长期存在支架这样一段缺乏顺应性及弹性的刚性结构,是否对心血管系统功能有影响尚有待进一步观察论证。
   总结
·  外科手术仍是婴幼儿主动脉缩窄的首选治疗方法。支架植入术是治疗青少年(>13岁)及成人主动脉缩窄的安全、有效、微创的外科开发式手术的替代方法;球囊成形术主要用于不适于支架植入术和外科手术的患者,如:早产儿、低体重儿、外科手术后及再狭窄的患者。随着支架及推送系统的不断改进,支架在主动脉缩窄治疗中的应用越来越广泛,不仅可用于严重的、复杂的主动脉缩窄,甚至有望突破年龄限制用于较小儿童。


参考文献
1. Jenkins NP, Ward C. Coarctation of the aorta: natural history and outcome after surgical treatment. Q J Med. 1999; 92:365-371.
2. 刘玉清,主编.心血管病影像诊断学.第2版.合肥:安徽科学技术出版社,2000;577.
3. 孙立忠,主编. 主动脉外科学. 北京:人民卫生出版社,2012.5.
4. Botta L, Russo V, Oppido G, et al. Role of endovascular repair in the management of late pseudo-aneurysms following open surgery for aortic coarctation. Eur J Cardiothorac Surg.2009; 36: 670-674.
5. Hoimyr H, Christensen TD, Emmertsen K, et al. Surgical repair of coarctation of the aorta: up to 40 years of follow-up. Eur J Cardiothorac Surg.2006; 30: 910-916.
6. Carr JA. The results of catheter based therapy compared with surgical repair of adult aortic coarctation. J Am Coll Cardiol 2006; 47: 1101-1107.
7. Massey R, Shore DF. Surgery for complex coarctation of the aorta. Int J Cardiol. 2004; Suppl 1:67-73.
8. Bouchart F, Dubar A, Tabley A, et al. Coarctation of the aorta in adults: surgical results and long-term follow-up. Ann Thorac Surg. 2000; 70: 1483-1488.
9. Sakurai T, Stickley J, Stumper O, et al. Repair of isolated aortic coarctation over two decades: impact of surgical approach and associated arch hypoplasia. Interact Cardiovasc Thorac Surg. 2012; 15: 865-870.
10. Singer MI, Rowen M, Dorsey TJ, et al. Transluminal aortic balloon angioplasty for coarctation of the aorta in the newborn. Am Heart J. 1982; 103:131-132.
11. Koerselman J, de Vries H, Jaarsma W, et al. Balloon angioplasty of coarctation of the aorta: A safe alternative for surgery in adults: Immediate and mid-term results. Catheter Cardivasc Interv. 2000; 50:28-33
12. Ho SY, Somerville J, Yip WC, et al. Transluminal balloon dilation of resected coarcted segments of thoracic aorta: Histological study and clinical implications. Int J Cardiol. 1988; 19:99-105.
13. Hijazi ZM, Fahey JT, Kleinman Cs, et al. Balloon angioplasty for recurrent coarctation of the aorta: immediate and long term results. Circulation. 1991; 84:1150-1156.
14. Fawzy ME, Awad M, Hassan W, et al. Long-term outcome (up to 15 years) of balloon angioplasty of discrete native coarctation of the aorta in adolescents and adults. J Am Coll Cardiol. 2004; 43:1062-1067.
15. Ovaert C, McCrindle BW, Nykanen D, et al. Balloon angioplasty of native coarctation: clinical outcomes and predictors of success. J Am Coll Cardiol. 2000; 35:988-996.
16. Rao PS, Galal O, Smith PA, et al. Five-to nin-year follow-up results of balloon angioplasty of native aortic coarctation in infants and children. J Am Coll Cardiol. 1996; 27:462-470.
17. Fletcher SE, Nihill MR, Grifka RG, et al. Balloon angioplasty of native coarctation of the aorta: Midterm follow-up and prognostic factors. J Am Coll Cardiol.1995; 25:730-734.
18. Shaddy RE, Boucek MM, Sturtevant JE, et al. Comparison of angioplasty and surgery for unoperated coarctation of the aorta. Circulation. 1993; 87:793-799
19. Fawzy ME, Dunn B, Galal O, et al. Balloon coarctation angioplasty in adolescents and adults: Early and intermediate results. Am Heart J.1992; 124:167-171.
20. Ino T, Kishiro M, Okubo M, et, al. Dilatation mechanism of balloon angioplasty in children: Assessment by angiography and intravascular ultrasound. Cardiovasc Intervent Radiol 1998;21:102-108
21. Ovaert C, Benson LN, Nykanen D, et al. Transcatheter treatment of coarctation of the aorta: Pediatr Cardiol. 1998; 19:27-44; discussion 45-47.
22. Pedra CA, Fontes VF, Esteves CA,et al. Stenting vs. balloon angioplasty for discrete unoperated coarctation of the aorta in adolescents and adults. Catheter Cardiovasc Interv. 2005; 64:495-506.
23. Macdonald S, Thomas SM, Cleveland TJ, et al. Angioplasty or stenting in adult coarctation of the aorta? A retrospective single center analysis over a decade. Cardiovasc Intervent Radiol. 2003; 26:357-364.
24. O’Laughlin MP, Perry SB, Lock JE, et al. Use of endovascular stents in congenital heart disease. Circulation. 1991; 83:1923-1939.
25. Ledesma M, Díaz y Díaz E, Alva Espinosa C, et al. Stents in aortic coarctation. Immediate results. Arch Inst Cardiol Mex. 1997; 67: 399-404.
26. Redington AN, Hayes AM, Ho SY. Transcatheter stent implantation to treat aortic coarctation in infancy. Br Heart J. 1993; 69: 80-82.
27. Ebeid MR, Prieto LR, Latson LA, et al. Use of balloon-expandable stents for coarctation of the aorta: initial results and intermediate-term follow-up. J. Am. Coll. Cardiol. 1997; 30: 1847–1852.
28. Alcibar J, Peña N, Oñate A, Cabrera A, et al. Primary stent implantation in aortic coarctation. mid-term follow-up. Rev Esp Cardiol. 2000; 52: 797-804.
29. Gunn J, Cleveland T, Gaines P, et al. Covered stent to treat co-existent coarctation and aneurysm of the aorta in a young man. Heart.1999; 82:351-355.
30. Cheatham JP. Stenting of coarctation of the aorta. Catheter Cardiovasc. Interv. 2001; 54:112–125.
31. 黄连军,俞飞成,蒋世良,等。覆膜Cheatham-Platinum支架置入治疗主动脉缩窄的疗效评价。中华放射学杂志。2006,40:1195-1197.
32. Forbes T, Matisoff D, Dysart J, et al. Treatment of coexistent coarctation and aneurysm of the aorta with covered stent in a pediatric patient. Pediatr Cardiol. 2003;24:289-91.
33. Rajan L, Dougherty K, Krajcer Z, et al. Endoluminal stent-graft repair in a patient with coarctation of the aorta and previous iatrogenic type B aortic dissection and expanding pseudoaneurysm. J Endovasc Ther. 2008;15:558-565.
34. Hussein H, Walsh K. First in man use of the Advanta trademark V12 ePTFE-coated stent in aortic. Catheter Cardiovasc Interv. 2009;74:101-102.
35. Kay JD, Chan KC. Aortic pseudo aneurysm complicating coarctation stenting successfully treated with a PTFE balloon expandable covered stent. Congenit Heart Dis. 2008; 3:209-212.
36. Duke C, Qureshi SA. Aortic coarctation and recoarctation: to stent or not to stent? J Interv Cardiol. 2001; 14:283-298.
37. Haji-Zeinali AM, Ghazi P, Alidoosti M, et al. Self-expanding nitinol stent implantation for treatment of aortic coarctation. J Endovasc Ther. 2009; 16:224-232.
38. Thanopoulos BD, Hadjinikolaou L, Konstadopoulou GN, et al. Stent treatment for coarctation of the aorta: intermediate term follow up and technical considerations. Heart. 2000; 84:65-70.
39. Tzifa A, Ewert P, Brzezinska-Rajszys G, et al. Covered Cheatham-platinum stents for aortic coarctation: early and intermediate-term results. J Am Coll Cardiol 2006; 47:1457-1463.
40. Magee AG, Brzezinska-Rajszys G, Qureshi SA, et al. Stent implantation for aortic coarctation and recoarctation. Heart. 1999; 82:600-606.
41. Suarez de Lezo J,Pan M,Romero M,et a1.Immediate and follow-up findings after stent treatment for severe coarctation of aorta.Am J Cardiol,l999; 83:400-406.
42. Akowuah E, Wilde P, Bryan AJ. Aortic coarctation secondary to in-stent stenosis of a covered aortic endoprosthesis. Ann Thorac Surg. 2008; 85:2142.
43. Thanopoulos BD, Hadjinikolaou L, Konstadopoulou GN, et al. Stent treatment for coarctation of the aorta: intermediate term follow up and technical considerations. Heart. 2000; 84: 65-70.
44. Marshall AC, Perry SB, Keane JF, et al. Early results and medium-term follow-up of stent implantation for mild residual or recurrent aortic coarctation. Am Heart J. 2000; 139:1054-1060.
45. Harrison DA, McLaughlin PR, Lazzam C, et al. Endovascular stents in the management of coarctation of the aorta in the adolescent and adult: one year follow up. Heart. 2001; 85:561-566.
46. Kenny D, Margey R, Turner MS, et al. Self-expanding and balloon expandable covered stents in the treatment of aortic coarctation with or without aneurysm formation. Catheter Cardiovasc Interv. 2008; 72:72-73.
47. Pedra CA, Fontes VF, Esteves CA, et al. Use of Covered Stents in the Management of Coarctation of the Aorta. Pediatr Cardiol. 2005; 26: 431-439.
48. Ohkubo M, Takahashi K, Kishiro M, et al. Histological findings after angioplasty using conventional balloon, radiofrequency thermal balloon, and stent for experimental aortic coarctation. Pediatr Int. 2004; 46:39-47.
49. Sadiq M, Malick NH, Qureshi SA et al. Simultaneous treatment of native coarctation of the aorta combined with patent ductus arteriosus using a covered stent. Catheter Cardiovasc Interv. 2003; 59:387-90.
50. Peuster M, Wohlsein P, Brugmannn M, et al. Long-term results after implantation of NOR-I biodegradable metal stents into the descending aorta of New Zealand white rabbits (Abstract). Cardiol Young 2000;10(Supple.2):3
51. Bruckheimer E, Dagan T, Amir G, Birk E, et al. Covered Cheatham–Platinum stents for serial dilation of severe native aortic coarctation. Catheter Cardiovasc. Interv. 2009; 74:117–123.
52. Bruckheimer E, Birk E, Santiago R, et al. Coarctation of the aorta treated with the Advanta V12 large diameter stent: acute results. Catheter Cardiovasc. Interv. 2010; 75:402–406.

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