Factors Related to Late False Lumen Enlargement after Thoracic Stent-Graft Placement for Type B Aortic Dissection

Purpose

To evaluate significant factors related to delayed aortic false lumen (FL) enlargement in patients who have undergone thoracic stent-graft placement for type B aortic dissection.

外伤性主动脉夹层的CT诊断(附2例报告)

目的：探讨外伤性主动脉夹层的早期CT表现。方法：回顾性分析在我院漏诊及确诊的外伤性主动脉夹层的CT表现。2例中1例行3次CT平扫,1例行CT平扫和增强扫描。结果：2例均为DeBakeyIU型主动脉夹层,1例3次CT平扫示降主动脉管腔进行性增宽,伴双侧胸腔积液;此例因漏诊,患者于2周后死亡。另1例CT平扫示降主动脉增粗,CT增强扫描明确诊断,主要表现为降主动脉扩张,可见真腔、假腔及内膜线;此例患者行支架植入术后,患者预后良好。结论：对于胸部外伤患者,CT平扫时应注意观察主动脉的直径,如果降主动脉增粗、尤其是进行性增粗时,应考虑主动脉夹层的可能。     

Morphologic Outcome after Endovascular Treatment of Complicated Type B Aortic Dissection

PurposeTo investigate the long-term morphologic changes of the aorta after thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissection and to analyze whether these changes differed between DeBakey class IIIa and IIIb dissections.Materials and MethodsDuring the period 1999–2009, 58 patients with acute complicated type B aortic dissection were treated with TEVAR. Seven patients lacked follow-up data, leaving 51 patients—17 patients with DeBakey IIIa aortic dissection and 34 patients with DeBakey IIIa aortic dissection IIIb—for inclusion in the study. Computed tomography scans performed before and after TEVAR were evaluated. Maximum thoracic and abdominal aortic diameters and diameters of the true lumen and false lumen at the level of the maximum aortic diameter in the thorax and abdomen were analyzed as well as degree of thrombosis of the false lumen.ResultsThere was an overall significant reduction of the thoracic aortic diameter, increased true lumen diameter, and reduced false lumen diameter (P < .05). Total thrombosis of the false lumen, with or without reintervention, was seen in 53% of all patients, in 41% primarily and in 12% after reintervention. The IIIa group had a higher degree of total false lumen thrombosis. All patients in the IIIb group had total thrombosis of the false lumen along the stent graft.ConclusionsLong-term follow-up showed favorable aortic remodeling after TEVAR for acute complicated type B aortic dissection. Total thrombosis of the false lumen occurred more often in patients with DeBakey IIIa aortic dissection compared with patients with DeBakey IIIb aortic dissection.     

Treatment of chronic aortic dissection by transluminal endovascular stent-graft placement: preliminary results.

PURPOSE: To investigate efficacy of stent-graft repair for the treatment of patients with chronic aortic dissection. MATERIALS AND METHODS: Fifteen patients with chronic aortic dissection were treated with endovascular stent-grafts. Entry tears were located in the descending thoracic aorta in all patients. The mean maximum diameter of the descending thoracic aorta was 47 mm +/- 8. The mean diameter of the true lumen at the same level was 20 mm +/- 5. The mean interval between diagnosis and stent-graft procedure was 32 months +/- 91. Stent-grafts were fabricated from expanded polytetrafluoroethylene and Z-stents. RESULTS: Stent-grafts were placed successfully in all patients. Two stent-grafts were required in one patient. Entry closure and thrombosis of the false lumen of the descending thoracic aorta were also achieved in all patients. No procedure-related complications were observed except for postimplantation syndrome, including fever and leukocytosis. The diameter of the true lumen was significantly increased (mean, 31 mm +/- 6) at the level of the descending thoracic aorta (P <.01) and the diameter of the aorta was significantly decreased (mean, 44 mm +/- 8) at the same level (P <.01). There were no deaths and no instances of aortic rupture during the subsequent average follow-up period of 24 months. Secondary stent-graft procedures were required to treat the abdominal component of dissection during follow-up in one patient. CONCLUSIONS: Stent-graft repair of chronic aortic dissection is a safe and effective method and may be an alternative to surgical graft replacement in selected patients. However, further evaluation is mandatory before this method is widely employed.     

Stanford B型主动脉夹层腔内修复术后早期死亡患者术前多层螺旋CT特征分析

目的探讨术前多层螺旋CT(MSCT)对Stanford B型主动脉夹层血管腔内修复术后早期死亡的预测价值。方法回顾性分析2014年1月至2018年12月采用腔内修复术治疗的158例急性期和亚急性期Stanford B型主动脉夹层患者临床随访资料和术前MSCT图像。测量和记录破口位置、破口大小、降主动脉最大直径、气管分叉平面主动脉直径、气管分叉平面假腔面积占该平面主动脉管腔总面积百分比、重要分支血管受累情况、假腔状态、腹主动脉是否受累等CT参数。分析术前CT各参数与患者术后30 d死亡的关系。结果腔内修复术紧急干预88例,非紧急干预70例,术后30 d死亡率为9.5%(15/158)。术后30 d死亡单因素分析显示,紧急干预患者术后30 d死亡率显著高于非紧急干预患者[13.6%(12/88)对4.3%(3/70),χ2=3.967,P=0.046];术后30 d死亡组患者气管分叉平面假腔面积占该平面主动脉管腔总面积≥50%患者[93.3%(14/15)对0.7%(1/143),χ2=135.581,P<0.001]和重要分支血管受累患者[66.7%(10/15)对32.9%(47/143),χ2=6.725,P=0.010]显著高于术后30 d生存组患者;两组患者破口位置、破口大小、降主动脉最大直径、气管分叉平面主动脉直径、假腔状态、腹主动脉是否受累比较,差异无统计学意义(P>0.05)。Logistic回归多因素分析显示,紧急干预(OR=1.31,95%CI=1.08~3.53,P=0.026)和气管分叉平面假腔面积占该平面主动脉管腔总面积≥50%(OR=9.53,95%CI=3.69~12.47,P<0.001)是Stanford B型主动脉夹层腔内修复术后30 d死亡的独立危险因素。结论术前MSCT对预测Stanford B型主动脉夹层腔内修复术后患者早期死亡具有重要价值,紧急干预和气管分叉平面假腔面积占主动脉管腔总面积≥50%是术后30 d死亡的独立危险因素。     

Endovascular treatment in diseases of the thoracic aorta

PURPOSE: To determine whether endovascular treatment of thoracic aorta conditions can be an effective alternative approach to surgical repair. MATERIAL AND METHODS: July 1997 to February 1999, eighteen patients (16 men and 2 women; 58.6 +/- 14.8 years) presenting with different kinds of descending aorta conditions were selected for the endovascular treatment. All patients exhibited severe comorbid pulmonary and/or cardiovascular medical conditions which increased surgical risk. All implants were performed in the operating room under fluoroscopic and TEE guidance. Clinical and imaging follow-up was performed 1, 3, 6 and 12 months later. RESULTS: The endovascular treatment was successful in 17 cases. No deaths or major complications occurred. No leakage was evident at post-procedure angiography. The patients were discharged after 6 +/- 4 days. MRI or CT study performed before hospital discharge showed aneurysms exclusion in 16 patients. In the four cases of dissection, thrombosis of the false lumen was evident since the first follow-up study. In the group of patients (11 cases) with 6 months follow-up, the diameters of stented aortic segments decreased. No late leakage was observed and thrombosis was complete in all cases. DISCUSSION: The natural history of aortic aneurysms and dissection is progressive toward dilation and aortic rupture. Surgery of descending thoracic aorta is burdened with a mortality of 8-12% in elective cases and over 50% in emergency cases or aortic dissection. The endovascular treatment of aortic conditions was introduced in clinical practice in 1991 and literature data show that it is effective, with lower mortality and morbidity rates than surgical treatment. CONCLUSION: Our results stress the feasibility and effectiveness of endovascular procedure in the treatment of complex thoracic aorta conditions even in high risk patients. Thus, endovascular treatment of thoracic aorta can be considered an effective alternative approach to conventional surgery.     

Endovascular repair of growing chronic type B aortic dissection with a vascular plug

We report the successful endovascular repair of a growing chronic type B aortic dissection using an Amplatzer Vascular Plug II. A 44-year-old man, with previous medical history of aortic surgery and stenting complained of vague back pain. An approximately 5-mm entry remained in the stented segment of the aorta on computed tomography (CT). Endovascular closure of the entry with a Vascular Plug was uneventful. A 3-month follow-up CT showed no leak, complete false lumen thrombosis in the thoracic segment, shrinkage of the false lumen, and a reduced diameter of thoracic aorta.     

Superior pericardial recess simulating aortic dissection on computed tomography

Computed tomography is frequently used in the initial workup of patients with suspected aortic dissection to distinguish dissection involving the ascending aorta from dissection limited to the descending aorta. We reviewed CT of 19 patients who were proven by aortography to have normal ascending aortas. In eight patients the superior extension of the pericardium was visualized and thought to be a potential source of a false-positive diagnosis of type A aortic dissection.     

Endovascular treatment of aortic type B dissection and penetrating ulcer using commercially available stent-grafts.

OBJECTIVE: The purpose of our study was to investigate the clinical experience and efficiency of translumenl endovascular stent-graft insertion using commercially available vascular endoprotheses. We studied seven patients with descending aortic dissection (type B) and four patients with penetrating aortic ulcer over a median follow-up period of 254 days during the years 1997-2000, using cross-sectional CT to evaluate the extent of the dissection, the distance between the entry tear and the left subclavian artery, and the diameter of the true lumen and the false lumen. CONCLUSION: Endovascular treatment of acute and chronic aortic type B dissections and penetrating ulcer is a minimally invasive method with a low complication rate that could be considered a feasible alternative to surgical repair. Depending on the length of the dissection, we recommend the placement of two overlapping stent-grafts in the thoracic aorta to stabilize the affected thoracic aorta over a longer distance. This might provide a reliable sealing of the entry tear and should prevent further communication between the true lumen and the false lumen.     

Thoracic Endovascular Aortic Repair for Type B Aortic Dissection Associated with Retrograde Type A Intramural Hematoma

PurposeTo evaluate feasibility and efficacy of thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) associated with retrograde type A intramural hematoma (IMH).Materials and MethodsFrom April 2013 to January 2017, 15 consecutive patients with TBAD associated with retrograde type A IMH who underwent TEVAR were reviewed retrospectively. There was no cardiac tamponade, aortic regurgitation, involvement of coronary artery, or sign of cerebral ischemia in these patients. Enhanced CT was used in 4 patients to diagnose malperfusion of abdominal visceral arteries or lower extremity artery and underwent emergent TEVAR. For the remaining 11 patients, repeated enhanced CT after initial medical treatment within 24 hours from onset of pain showed expansion of IMH in 8 patients or presence of periaortic hematoma in 3 patients. Delayed TEVAR was scheduled for these cases.ResultsSuccessful deployment of the stent graft was achieved in all patients. There were no severe postoperative complications, such as retrograde type A aortic dissection or aortic rupture. Sudden death occurred in 1 patient 3 months after the procedure. Thrombosis of the false lumen, shrinkage of the diameter of the aorta, and complete absorption of the IMH were observed in the remaining patients at a mean follow-up of 19.8 months ± 6.57.ConclusionsTEVAR for treatment of TBAD with retrograde type A IMH is feasible and effective. It represents a treatment option for patients with TBAD associated with type A IMH with a proximal entry tear located in the descending aorta.     

特殊类型主动脉夹层的电子束CT表现及诊断

目的探讨表现特殊的主动脉夹层的电子束CT(EBCT)影像特征及诊断.材料和方法20例表现特殊的主动脉夹层,其中不典型夹层13例,三腔以上夹层动脉瘤3例,合并升主动脉壁内血肿的Stanford B型夹层2例,动脉瘤样夹层1例,外伤性主动脉夹层1例.结果主动脉不典型夹层为主动脉壁新月形或环形的低密度血肿包绕,常可见穿透性溃疡或钙化内移等征象;三腔以上夹层动脉瘤有2～3个内膜片,3～4个腔,瘤体管径较大;合并升主动脉壁内血肿的B型夹层见升主动脉管壁低密度新月形或环形增厚,降主动脉则见内膜片及真假两腔形成;动脉瘤样主动脉夹层见降主动脉局限性瘤样扩张,破口大,内膜片不易发现.1例外伤性夹层于主动脉弓峡部及降部起始见破裂内膜片.结论特殊类型的主动脉夹层表现各具特征,EBCT可清晰显示,是极适用于胸部急症的快速、无创的检查方法.     

Useful CT findings for predicting the progression of aortic intramural hematoma to overt aortic dissection

PURPOSE: The purpose of this work was to assess useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection. METHOD: We analyzed the CT findings of 29 patients with aortic intramural hematoma with regard to the following: involved site, maximum thickness of hematoma, presence or absence of compression of true lumen, and pericardial and pleural effusion. CT findings were compared with those of the patients who progressed to aortic dissection (Group I) and those who did not (Group II). Each CT finding was evaluated with independent t test and Mann-Whitney U test (p < 0.05). RESULTS: Seven of 8 cases of Type A aortic intramural hematoma and 3 of 21 cases of Type B aortic intramural hematoma progressed to aortic dissection. The type of aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion were significantly different in Groups I and II. CONCLUSION: Type A aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion are the useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection.     

CT diagnosis of acute aortic dissection; clinical importance of acute aortic dissection with non-opacified false lumen

Sixteen (47.5%) of 35 patients with acute aortic dissection showed a non-opacified crescent in the aorta on an initial contrast CT. Seven of these 16 patients underwent cineangiography soon after the initial CT, and in all 7 patients, neither an intimal tear nor an intimal flap was obtained. All but one of above 16 patients were followed by CT. Mean duration of follow-up was 9.6 months. In 10 of 15 patients with non-opacified false lumen, the false lumen remained non-opacified until the last examination. Moreover, in 6 of these 10 patients, the false lumen shrunk, and in the other 3, it disappeared completely on follow-up CT. On the other hand, in remaining 5 of these 15 patients who were initially diagnosed to have non-opacified false lumen, the false lumen became opacified and enlarged in size on follow-up CT performed in the first 14 weeks. Moreover, in 4 of these 5 patients, the false lumen became opacified in the only first 6 weeks. No matter how intensive care should be paid at least for the first 6 weeks, it seems that patients with aortic dissection which have non-opacified false lumen had good prognosis in comparison to patients with ordinary aortic dissections which have opacified false lumen. We believe aortic dissection with non-opacified false lumen may consist of two type of aortic dissection, one has no intimal tear, the other has some intimal tears and a thrombosed false lumen. In conclusion, CT is the most useful modality in diagnosing acute aortic dissection. The reasons are the incidence of acute aortic dissection with non-opacified false lumen was high, patients with non-opacified false lumen had good prognosis, and it was difficult to diagnose aortic dissection with non-opacified false lumen by conventional cineangiography and/or DSA.     

Penetrating atherosclerotic ulcers of the descending thoracic aorta: evaluation with CT and distinction from aortic dissection.

Penetrating atherosclerotic ulceration of the aorta is a poorly understood entity that clinically mimics classic aortic dissection but has imaging features that are distinctly different. In a review of 16 patients with penetrating atherosclerotic ulceration, patients were typically hypertensive (n = 14), and they experienced chest or back pain (n = 13). All patients had an abnormal chest radiograph, with diffuse (n = 14) or focal (n = 2) enlargement of the descending thoracic aorta. Features at contrast material-enhanced computed tomography (CT) included intramural hematoma (n = 16), focal ulcer (n = 15), displaced intimal calcification (n = 13), pleural and/or extrapleural fluid (n = 7), mediastinal fluid (n = 4), and a thick or enhancing aortic wall (n = 6). The chest radiograph and CT findings were compared in patients treated conservatively (n = 9) and surgically (n = 7). These findings did not correlate with the need for surgery. Eight of nine conservatively treated patients were asymptomatic after treatment with antihypertensive medication. Contiguous dynamic contrast-enhanced CT of the aorta enables distinction of ulceration from dissection, which is particularly important in the hemodynamically unstable patient because the surgical management of ulceration is more extensive than that for aortic dissection.     

Diagnosis of acute thoracic aortic dissection using combined echocardiography and computed tomography.

Acute dissection of the thoracic aorta is a life-threatening emergency requiring a diagnosis which is rapid, accurate and safe, and which will distinguish between dissections involving the ascending and descending aorta. In the absence of any general agreement on the best method of making this diagnosis we studied the use of combined echocardiography and contrast-enhanced computed tomography (CT) to diagnose acute aortic dissection. Over a 3 year period 23 patients were investigated in this way. Aortic dissection was demonstrated in 18 cases, involving the ascending aorta in 15, and the descending aorta alone in three. The diagnosis of aortic dissection was confirmed in 13 patients at surgery, in one at aortography and in one at autopsy. Three patients died without surgery or autopsy being performed to confirm the diagnosis and the subsequently which accounted for their symptoms. This combined approach has proved a valuable and safe means of investigating aortic dissection.     

超声、MR、CT、X线诊断主动脉夹层的比较

目的：比较超声、MR、CT及X线对主动脉夹层的诊断价值。方法：2005—01～2008—09经手术病理证实的26例主动脉夹层患者,26例均经超声、X线检查,17例经MR及CT检查,重点观察超声主动脉声像,内膜有无撕裂及撕裂部位,真假腔血流情况,主动脉瓣有无受累及瓣膜反流情况、心包积液、左室收缩功能等。结果．26例超声诊断25例,其中12例为DeB—bakeyI型,占46．2％,5例为Ⅱ型,占19．2％,9例为Ⅲ型,占34．6％,I型最常见。19例中量以上主动脉瓣反流,7例少量主动脉瓣反流,9例少一中量心包积液。16例LVEF％及LVFS％降低。17例经MR及CT检查诊断15例,26例胸片提示主动脉增宽,心影增大。结论：超声可作为诊断主动脉夹层的首选检查项目。     

Relay NBS Graft with the Plus Delivery System to Improve Deployment in Aortic Arch with Small Radius Curve

The purpose of this report is to describe deployment of the Relay NBS Thoracic Stent Graft with the Plus Delivery System (Bolton Medical, Sunrise, FL) in a flexible resin arch model with a 15-mm radius curve as well as our preliminary clinical results. The Relay NBS graft with the Plus Delivery System was evaluated by way of bench testing, which was performed with stent grafts with diameters ranging from 24 to 46 mm and lengths ranging from 100 to 250 mm in flexible resin arch models with a 15-mm arch radius of curvature. The deployment sequence was analyzed. The Relay NBS graft with the Plus Delivery System was deployed in two patients, respectively, having a 6.5-cm penetrating aortic ulcer of the proximal third of the descending thoracic aorta and a DeBakey type-I aortic dissection with chronic false lumen dilatation after surgery due to an entry site at the distal thoracic aorta. Bench tests showed proper conformation and apposition of the Relay NBS graft with the Plus Delivery System in the flexible resin model. This stent graft was deployed successfully into the two patients with a correct orientation of the first stent and without early or late complications. The Relay NBS graft with the Plus Delivery System ensures an optimal conformation and apposition of the first stent in the aortic arch with a small radius of curvature.     

64层螺旋CT对主动脉夹层的应用价值

目的:探讨64层螺旋CT诊断主动脉夹层的临床价值。方法:39例拟诊为主动脉病变的患者作为本组研究对象,对所有患者行CT平扫及增强扫描。CT平扫图像上观察内膜钙化的移位、主动脉直径扩大、心包和/或纵隔积血、胸腔积液/血。并对A型和B型主动脉夹层的平扫征象进行统计学比较。CT增强图像上观察低密度的内膜瓣、破口(入口和再入口)、真假腔及主要动脉分支受累情况。结果:21例主动脉夹层中,CT平扫观察到钙化的内膜瓣移位9例(42.9%),主动脉直径增宽8例(38.1%),心包和/或纵隔积血8例(38.1%),胸腔积液/血5例(19.0%)。CT增强扫描对主动脉夹层内膜瓣的显示率达100%(21/21),对真、假腔的显示率为100%(21/21),对破口的显示率为85.7%(18/21)。8例(38.1%)弓上血管受累,5例(19.0%)内脏血管受累。结论:64层螺旋CT对主动脉夹层有较高的诊断价值,能较好的显示夹层的真假腔、内膜瓣及破口,并且可以显示主要动脉受累情况,为外科的手术治疗提供重要信息。     

Elective endovascular treatment of descending thoracic aortic aneurysms and chronic dissections with stent-grafts

PURPOSE: To report our experience of endovascular stent-graft placement in patients with descending thoracic aortic dissections and aneurysms and to evaluate the feasibility, safety, and clinical outcomes of the treatment. MATERIALS AND METHODS: Stent-grafts were placed in the descending thoracic aortas of 23 patients with saccular aneurysms (n = 11) and Stanford type B chronic aortic dissections of the descending thoracic and abdominal aorta (n = 12). All stent-grafts were individually constructed of self-expandable stainless steel stents covered with polytetrafluoroethylene. Vascular access was achieved through the femoral artery in all patients. Clinical status of each patient was monitored and postoperative CT was performed within 1 month of the procedure and at 3-12-month intervals after the procedures. RESULTS: Successful exclusion of the primary entry tears of dissections and the inlets of saccular aneurysms was achieved in all but two patients with aortic dissection. The overall technical success rate was 91.3% (dissection: 10 of 12 = 83%; aneurysm: 11 of 11 = 100%). All patients in whom technical success was achieved showed complete thrombosis and significant decrease in diameter of the thoracic false lumen (preoperative: 5.3 cm +/- 0.9; postoperative: 4.3 cm +/- 0.9; P = .004) or aneurysm sac (preoperative: 5.3 cm +/- 1.7; postoperative: 2.8 cm +/- 2.5; P = .001). In addition, five patients demonstrated complete resolution of the dissected thoracic false lumen (n = 2) and aneurysm sac (n = 3). However, in all patients with aortic dissection, the abdominal aorta was not significantly changed in size (P = .302) and shape and their false lumen flows remained persistent. Immediate postoperative complications were detected in 12 patients (52%); 10 had fever, leukocytosis, and elevation of C-reactive protein, another had wound infection, and another had transient abdominal pain. Three patients died 2, 3, and 12 months after the procedure: one from septic shock, another from underlying mediastinitis, and the other from an unexplained cause. The remaining 20 patients were well after the procedure (1-9 days; mean, 3 days), without any stent-graft-related complications or discomfort (follow up period: 10-65 mo; mean: 25.1 mo +/- 15.6). The cumulative survival rate after the stent graft was 100% at 30 days and 91% at 12 months. CONCLUSIONS: For treatment of aortic dissection and saccular aneurysm of the descending thoracic aorta, endovascular stent-graft repair may be a technically feasible and effective treatment modality.     

False Lumen Stent-Grafts for Repair of Postdissection Aortic Aneurysms

PurposeTo evaluate the safety and efficacy of false lumen (FL) stent-grafts in the treatment of postdissection aortic aneurysms.Materials and MethodsEleven patients who underwent endovascular repair using FL stent-grafts from January 2016 to June 2019 were included. Among them, 2 patients had a prior history of type A aortic dissection, whereas 9 had undergone a prior endovascular repair for type B aortic dissection. Computed tomography angiography was performed to evaluate the reintervention and technical success rate, aortic remodeling, and other related aortic complications.ResultsThe mean age of patients was 55.6 ± 10.4 years. Technical success was achieved in all patients, and neither early mortality nor paralysis occurred. In total, 8 visceral branch arteries originating from the FL were reconstructed. The true lumen areas at the celiac axis, superior mesenteric artery, renal artery, and abdominal aortic bifurcation were significantly increased from 230.1 mm² to 312.3 mm², 212.1 mm² to 277.5 mm², 209.1 mm² to 291.6 mm², and 214.4 mm² to 300.6 mm², respectively (P < .05). The total diameter of the aorta at the 4 designated levels was stable or had shrunk in all patients. At a mean follow-up of 18.9 ± 7.6 months, 1 patient received re-intervention owing to iliac stent-graft occlusion. No aortic-related mortality occurred.ConclusionsFL stent-grafts can safely and effectively treat patients with postdissection aortic aneurysms. This strategy can be used to promote thrombosis of the FL and aortic remodeling. A larger sample and an extended follow-up period are needed to produce more conclusive results.