Stanford B型主动脉夹层动脉瘤腔内隔绝术后截瘫的预防对策

目的 探讨Stanford B型胸主动脉夹层动脉瘤(TAD)腔内隔绝术(EVE)后截瘫或轻瘫的综合防治措施。方法 回顾在1998年至2001年实施的116例TAD EVE。对于可能发生截瘫的高危患者，术后常规给予地塞米松。结果 包括接受脊髓动脉造影者在内，成功释放并固定移植物的115例中，均无截瘫或轻瘫发生。结论 EVE虽避免了长时间主动脉阻断，但仍可因封闭肋间动脉造成脊髓的严重缺血，包括选择性脊髓动脉造影、糖皮质激素在内的综合性预防措施能减小发生截瘫／轻瘫的危险，而选择适当长度的移植物是其关键。     

裸支架在腹主动脉瘤腔内隔绝术后近端内漏治疗中的应用

目的：探讨应用裸支架治疗主动脉瘤腔内隔绝术后近端内漏的价值和安全性。方法：使用裸支架地治疗原发性内漏3例，继发性内漏1例。1例裸支架在肾动脉下固定。3例跨双侧肾动脉开口固定。结果：裸支架均成功置入，近端内漏完全消除，术后未观察到肾功能受损、裸支架移位和近端内漏复发等并发症。结论：使用裸支架法治疗近端内漏，是一种安全、有效、可行的选择。     

Placement of endovascular stent-grafts for emergency repair of acute traumatic aortic rupture: a single-centre experience

The aim of this retrospective study was to evaluate mid- and long-term results of endovascular stent-graft placement for emergency repair of acute traumatic thoracic aortic rupture. From 1996 through 2005, 22 consecutive patients (mean age: 38.7 years) underwent endovascular repair of acute traumatic thoracic aortic rupture located at the aortic isthmus in most cases. All patients were at high surgical risk due to severe associated injuries. The endografts were inserted via femoral or iliac artery access under fluoroscopic guidance. Follow-up was performed postinterventionally, at 6 and 12 months and yearly thereafter, and included clinical examination and computed tomography (CT) scans. Technical and clinical success rates were 86.3%. Mean follow-up was 31.7 months. Three patients developed early type I endoleak due to the inability of the rigid graft to adapt to the curved aortic contour. In two of them conversion to open surgery was necessary. One patient had late type I endoleak and died. No other complications were observed. The outcome was successful in most patients. The mid- and long-term results of our current study are promising. However, early type I endoleak represents a problem, especially in adolescent patients with a marked curvature of the aortic arch.     

Treatment of chronic type B aortic dissection with endovascular stent-graft placement

A 74-year-old man with chronic aortic dissection was treated with an endovascular stent graft, fabricated from expanded polytetrafluoroethylene and a Z-stent. It was placed in the true lumen to close an entry tear. Closure was obtained immediately and thrombosis of the false lumen at the descending thoracic aorta was observed on computed tomography (CT) obtained 1 week later. No procedure-related complications developed. The patient is doing well with no adverse events including aortic rupture or aortic branch ischemia.     

In vitro validation of flow measurements in an aortic nitinol stent graft by velocity-encoded MRI

Purpose

To validate flow measurements within an aortic nickel–titanium (nitinol) stent graft using velocity-encoded cine magnetic resonance imaging (VEC MRI) and to assess intraobserver agreement of repeated flow measurements.

Materials and methods

An elastic tube phantom mimicking the descending aorta was developed with the possibility to insert an aortic nitinol stent graft. Different flow patterns (constant, sinusoidal and pulsatile aortic flow) were applied by a gear pump. A two-dimensional phase-contrast sequence was used to acquire VEC perpendicular cross-sections at six equidistant levels along the phantom. Each acquisition was performed twice with and without stent graft, and each dataset was analysed twice by the same reader. The percental difference of the measured flow volume to the gold standard (pump setting) was defined as the parameter for accuracy. Furthermore, the intraobserver agreement was assessed.

Results

Mean accuracy of flow volume measurements was −0.45 ± 1.63% without stent graft and −0.18 ± 1.45% with stent graft. Slightly lower accuracy was obtained for aortic flow both without (−2.31%) and with (−1.29%) stent graft. Accuracy was neither influenced by the measurement position nor by repeated acquisitions. There was significant intraobserver agreement with an intraclass correlation coefficient of 0.87 (without stent graft, p < 0.001) and 0.80 (with stent graft, p < 0.001). The coefficient of variance was 0.25% without stent graft and 0.28% with stent graft.

Conclusion

This study demonstrated high accuracy and excellent intraobserver agreement of flow measurements within an aortic nitinol stent graft using VEC MRI. VEC MRI may give new insights into the haemodynamic consequences of endovascular aortic repair.     

CT appearance of complications related to thoracic endovascular aortic repair (TEVAR): a pictorial essay

Thoracic endovascular aortic repair (TEVAR) is a recognized treatment for various diseases involving the thoracic aorta. Patients treated with TEVAR require lifelong surveillance for potential complications, with CT being highly utilized in most centres. Endoleak is the most common complication and can be detected using CT. However, other complications such as stent strut perforations and end organ ischemia can also be detected on CT. The purpose of this pictorial essay is to illustrate the CT appearance of post-TEVAR complications encountered in our institution and to highlight their significance.     

Prospective, intraindividual comparison of MRI versus MDCT for endoleak detection after endovascular repair of abdominal aortic aneurysms

This study compares MRI and MDCT for endoleak detection after endovascular repair of abdominal aortic aneurysms (EVAR). Forty-three patients with previous EVAR underwent both MRI (2D T1-FFE unenhanced and contrast-enhanced; 3D triphasic contrast-enhanced) and 16-slice MDCT (unenhanced and biphasic contrast-enhanced) within 1 week of each other for endoleak detection. MRI was performed by using a high-relaxivity contrast medium (gadobenate dimeglumine, MultiHance®). Two blinded, independent observers evaluated MRI and MDCT separately. Consensus reading of MRI and MDCT studies was defined as reference standard. Sensitivity, specificity, and accuracy were calculated and Cohen’s k statistics were used to estimate agreement between readers. Twenty endoleaks were detected in 18 patients at consensus reading (12 type II and 8 indeterminate endoleaks). Sensitivity, specificity, and accuracy for endoleak detection were 100%, 92%, and 96%, respectively, for reader 1 (95%, 81%, 87% for reader 2) for MRI and 55%, 100%, and 80% for reader 1 (60%, 100%, 82% for reader 2) for MDCT. Interobserver agreement was excellent for MDCT (k?=?0.96) and good for MRI (k?=?0.81). MRI with the use of a high-relaxivity contrast agent is significantly superior in the detection of endoleaks after EVAR compared with MDCT. MRI may therefore become the preferred technique for patient follow-up after EVAR.     

内支架置入术治疗胸腹主动脉瘤的临床评价

目的：探讨胸腹主动脉瘤的ESG治疗临床疗效。方法：对10例患者分别行CTA、MRA、DSA检查和ESG治疗，其中Stanford B型夹层动脉瘤6例，真性腹主动脉瘤2例，肾动脉开口以下腹主动脉瘤2例（行分体式支架），所有病例均采用带膜支架。结果：8例行一体式支架腔内隔绝术，2例行分体式支架腔内隔绝术，均获成功。顺利植入，术后造影提示动脉瘤消失．无内漏发生。患者症状完全消失，全部患者在随访期间均未出现术前症状，未见相关并发症。结论：应用ESG治疗胸腹主动脉瘤安全、有效、创伤小、术后恢复快，长期疗效尚待进一步观察。     

The role of aortic wall CT attenuation measurements for the diagnosis of acute aortic syndromes

Objectives

To determine if measurements of aortic wall attenuation can improve the CT diagnosis of acute aortic syndromes.

Methods

CT reports from a ten year period were searched for acute aortic syndromes (AAS). Studies with both an unenhanced and a contrast enhanced (CTA) series that had resulted in the diagnosis of intramural hematoma (IMH) were reviewed. Diagnoses were confirmed by medical records. The attenuation of aortic wall abnormalities was measured. The observed attenuation threshold was validated using studies from 39 new subjects with a variety of aortic conditions.

Results

The term “aortic dissection” was identified in 1206, and IMH in 124 patients’ reports. IMH was confirmed in 31 patients, 21 of whom had both unenhanced and contrast enhanced images. All 21 had pathologic CTA findings, and no CTA with IMH was normal. Attenuation of the aortic wall was greater than 45 HUs on the CTA images in all patients with IMH. When this threshold was applied to the new group, sensitivity for diagnosing AAS was 100% (19/19), and specificity 94% (16/17). Addition of unenhanced images did not improve accuracy.

Conclusions

Measurements of aortic wall attenuation in CTA have a high negative predictive value for the diagnosis of acute aortic syndromes.     

Role of contrast-enhanced helical CT in the evaluation of acute thoracic aortic injuries after blunt chest trauma

The purpose of this retrospective study was to determine the value of contrast-enhanced helical CT for detecting and managing acute thoracic aortic injury (ATAI). Between June 1995 and February 2000, 1419 consecutive chest CT examinations were performed in the setting of major blunt trauma. The following CT findings were considered indicative of ATAI: intimal flap; pseudoaneurysm; contour irregularity; lumen abnormality; and extravasation of contrast material. On the basis of these direct findings no further diagnostic investigations were performed. Isolated mediastinal hematoma on CT scans was considered an indirect sign of ATAI: In these cases, thoracic aortography was performed even if CT indicated normal aorta. Seventy-seven patients had abnormal CT scans: Among the 23 patients with direct CT signs, acute thoracic aortic injuries was confirmed at thoracotomy in 21. Two false-positive cases were observed. The 54 remaining patients had isolated mediastinal hematoma without aortic injuries at CT and corresponding negative angiograms. The 1342 patients with negative CT scans were included in the 8-month follow-up program and did not show any adverse sequela based on clinical and radiographic criteria. Contrast-enhanced helical CT has a critical role in the exclusion of thoracic aortic injuries in patient with major blunt chest trauma and prevents unnecessary thoracic aortography. Direct CT signs of ATAI do not require further diagnostic investigations to confirm the diagnosis: Isolated aortic bands or contour vessel abnormalities should be first considered as possible artifacts or related to non-traumatic etiologies especially when mediastinal hematoma is absent. In cases of isolated mediastinal hematoma other possible sources of bleeding should be considered before directing patients to thoracic aortography.     

多层螺旋CT造影在主动脉病变腔内修复术后随访的价值

目的:探讨多层螺旋CT血管造影(multi-detector rowspiral computed tomography angiography,MDCTA)及后处理技术在主动脉覆膜支架腔内修复术(transluminal stent-graft placement,TSGP)术后随访的临床应用价值。方法:21例接受TSGP主动脉疾病患者,包括:Stanford B型夹层13例,真性动脉瘤3例,假性动脉瘤2例,弓降部穿透性溃疡1例,胸主动脉瘤合并局限性夹层1例,胸主动脉瘤合并Stanford B型夹层1例,术后采用MDCTA进行随访,平均随访13个月(1~24个月)。采用轴位图像与多种重建图像相结合来显示支架形态、术前术后主动脉管腔情况的变化和有无并发症。结果:13例主动脉夹层覆膜支架置入后:所有患者均真腔扩大,假腔减小或消失并伴血栓形成,支架未发现移位或断裂;共3例(14%)随访中发现内漏,1例Ⅱ型内漏,建议随访观察;1例术后8个月复查新发现支架近端Ⅰ型内漏,密切随访2个月后患者出现胸痛,复查CT内漏增多,转外科治疗。1例腹主动脉瘤术后1月复查发现Ⅲ型内漏。所有患者介入术后CT随访图像均满足临床诊断需要。结论:MDCTA对主动脉覆膜支架置入术后随访较其他检查手段具有多方面的优越性,能及时观察术后疗效、发现并发症,对主动脉疾病覆膜支架腔内修复术后随访具有重要价值。     

螺旋CT在主动脉夹层腔内隔绝术治疗中的应用价值

目的 探讨螺旋CT血管成像在主动脉夹层动脉瘤腔内隔绝术后评估中的应用价值。方法 31例StanfordB型夹层动脉瘤腔内隔绝术采用螺旋CT评估,26例单用螺旋CT评估,5例加做MR血管造影（MRA）,判断裂口位置、夹层真假腔、夹层范围。结果 螺旋CT显示近端裂口的敏感性为100％,夹层动脉瘤真假腔的识别率为100％;近端裂口位置与术中DSA所见相符合者29例,准确性为93．54％,2例与DSA不符合者,未影响手术方案以及移植物的选择。夹层范围识别的准确性为100％,基于CT结果选择移植物的准确性为100％。结论 CT增强像适合裂口的评判、相关数据的采集。其他多种方式的重建有利于整体解剖形态、夹层范围的观察。模拟内窥镜成像对裂口观察有较大帮助。螺旋CT在腔内隔绝术的术前评估中有重要价值,可作为常规术前检查。     

ⅡC型腹主动脉瘤腔内隔绝术中髂内动脉的处理

目的：总结累及髂动脉分叉的ⅡC型腹主动脉瘤（AAA）的处理方法。方法：自1997年3月至2002年10月共对42例ⅡC型AAA实施了腔内隔绝术，其中包括单侧髂动脉分叉受累者19例，双侧髂动脉分叉受累者23例。针对髂总动脉不同的病变情况，采取了保留健侧髂内动脉、一侧髂内动脉重建、髂总动脉外绑扎等不同的处理方法。结果：即时操作成功41例（97.6％），手术结束时无Ⅰ型内漏存在。术后出现臀、股部疼痛3例（7.5％），便血2例（5.0％），未发生臀、股部和结、直肠坏死。结论：通过对髂内动脉作不同的处理，应用腔内隔绝术治疗ⅡC型AAA完全可以取得满意疗效。术中应尽可能保留一侧髂骨动脉，避免同时封闭双侧髂内动脉。     

Benefit of adaptive CT-based treatment planning in high-dose-rate endorectal brachytherapy for rectal cancer

PurposeIn this planning study, we investigated the dosimetric benefit of repeat CT-based treatment planning at each fraction vs. the use of a single CT-based treatment plan for all fractions for high-dose-rate endorectal brachytherapy (HDREBT) for rectal cancer.Methods and MaterialsWe included 11 patients that received a CT scan with applicator in situ for all three fractions. The treatment plan of the first fraction was projected on the repeat CT scans to simulate the use of a single treatment plan. In addition, replanning was performed on the repeat CT scans, and these were compared to the corresponding projected treatment plans.ResultsRepeat CT-based treatment planning resulted on average in a 21% higher (p = 0.01) conformity index compared to single CT-based treatment planning. Projecting the initial treatment plan to the repeat CT scans of fraction two and three, 12/22 fractions reached a CTV D98 of 85% of the prescribed dose of 7 Gy, which increased to 14/22 using replanning. For the remaining fractions, median CTV D98 was 4.2 Gy, and an intervention would be necessary to correct applicator balloon setup or to remove remaining air and/or feces between the CTV and the applicator.ConclusionsUsing a single CT-based treatment plan for all fractions may result in a suboptimal treatment at later fractions. Therefore, repeat CT imaging should be the minimal standard practice in HDREBT for rectal cancer to determine whether an intervention would be necessary. Replanning based on repeat CT imaging resulted in more conformal treatment plans and is therefore recommended.     

Stanford B型主动脉夹层腔内修复术后死亡原因分析

目的分析Stanford B型主动脉夹层行腔内修复术(EVAR)治疗后死亡原因。方法回顾性分析2002年4月至2014年12月沈阳军区总医院心内科收治的Stanford B型主动脉夹层行EVAR治疗554例患者的临床资料,通过统计筛选出术后死亡患者,分析死亡原因及相关特征。结果本组554例患者中,47例患者术后死亡,占8.5%。其中,12例患者术后1个月死亡,占总死亡患者的25.5%;35例患者于术后中远期死亡。31例(66.0%)患者为急性期主动脉夹层,16例(34.0%)患者为慢性期主动脉夹层。24例患者死于AD破裂占51.1%;7例患者为心源性死亡,占14.9%;6例为脑源性死亡,占12.8%;4例为肿瘤源性死亡,占8.5%,其他原因死亡患者6例,占12.8%。结论主动脉破裂是Stanford B型降AD患者行EVAR治疗后死亡的主要原因,注重术中操作、术后近期患者管理有利于降低术后近期病死率,长期血压控制及影像随访有利于改善远期预后。     

MR angiography vs CT angiography in the follow-up of nitinol stent grafts in endoluminally treated aortic aneurysms

Our objective was to evaluate the accuracy of contrast-enhanced 3D MR angiography (MRA) in the follow-up of patients with endoluminally treated aortic aneurysms and correlate these findings with uni- or biphasic CT angiography (CTA). Forty MR angiograms in 32 patients with implanted aortic nitinol stent grafts were compared to CTA. Twenty-two MR examinations were correlated with arterial-phase CTA (uniphasic), and 18 MR examinations were correlated with biphasic CTA. Uniphasic CTA demonstrated three type-1/type-3 endoleaks and four reperfusion (type-2) endoleaks. In addition, MRA depicted two type-2 reperfusion endoleaks that were missed by CTA. Using biphasic CTA, two type-1/type-3 endoleaks and three reperfusion (type-2) endoleaks were detected; of those, delayed scanning detected three reperfusion (type-2) endoleaks missed during arterial-phase CTA. In addition to the findings by CTA, MRA depicted another type-2 reperfusion endoleak. Magnetic resonance angiography is at least as sensitive as uni- or biphasic CTA for detecting endoleaks and may consequently offer advantages in patients with contraindications to iodinated contrast agents.     

腹主动脉瘤腔内隔绝术中肱股导丝牵张技术的应用

目的　探讨肱股导丝牵张技术在腔内隔绝术 (EVE)治疗腹主动脉瘤 (AAA)中的操作要点和应用价值。方法　对本中心自 1997年 3月至 2 0 0 2年 10月间施行的 136例AAAEVE进行了回顾性研究。选用主体 单肢对接型移植物者 118例 (Vanguard 6例 ,Talent 86例 ,Aneurx 2例 ,Zenith 3例 ,国产 2 1例 )。使用肱股导丝牵张技术完成操作的共 12例。均使用 0 .0 38英寸的 2 6 0cm长泥鳅导丝经左肱动脉穿刺导入。结果　 12例采用肱股导丝牵张技术的手术全部实现移植物顺利导入、连接、释放 ,1例术后出现肱动脉血栓形成 ,1例出现左前臂内侧皮神经损伤 ,未发生左上肢及左侧椎动脉系统的血管并发症和其他切口并发症。其中 9例从手术开始即采用肱股导丝牵张技术 ,从移植物主体导鞘退出到短肢释放完成的时间为 5～ 11min ,平均 7.7min ,明显短于使用其他方法连接移植物短肢所消耗的时间。结论　对于瘤体直径 >6cm且与髂总动脉轴线成角 >4 5°、瘤颈扭曲 >30°或髂动脉扭曲 >4 5°、患者年龄超过 75岁合并一个以上重要脏器功能不全 ,不能耐受长时间手术的AAA患者 ,肱股导丝牵张技术有明显优势。     

双源CT大螺距联合智能调制及迭代重建技术在主动脉夹层成像中的应用

目的 探讨第2代双源CT大螺距扫描联合智能调制技术及迭代重建技术在急诊主动脉夹层成像中的临床应用价值。方法 连续纳入临床怀疑主动脉夹层成像的急诊患者40例,按随机数表法分为对照组和试验组,每组各20例。对照组行常规扫描,试验组行大螺距联合智能调制技术及迭代重建技术扫描。对主动脉平均CT值、平均噪声、信噪比（SNR）、对比噪声比（CNR）、有效剂量,图像整体质量和主动脉根部图像质量进行评价和分析。结果 40例患者均成功完成CT主动脉夹层成像。对照组与试验组的图像整体质量无差异（P>0.05）;但试验组主动脉根部图像质量比对照组好,差异有统计学意义（χ²=22.556,P<0.05）。对照组主动脉平均CT值、平均噪声略高于试验组,但试验组的SNR、CNR高于对照组,差异有统计学意义（t=-21.042、-15.924、8.530、11.495,P<0.05）。对照组有效剂量（10.59±3.89）mSv明显高于试验组的（6.39±0.81）mSv,差异有统计学意义（t=-12.327,P<0.05）。结论 双源CT大螺距扫描联合智能调制技术及迭代重建技术能保证图像整体质量,降低有效剂量,可作为急诊CT主动脉夹层的对照成像方法。     

腹主动脉瘤腔内隔绝术导入动脉相关并发症的认识和处理

目的：探讨腹主动脉瘤（AAA）腔内隔绝术（EVE）中导入动脉相关并发症的处理方法。方法：自1997年3月至2002年10月共对136例AAA实施了EVE，导入动脉主要相关并发症有导入动脉不良（包括动脉冗和扭曲、直径过细、局部狭窄或闭塞）、导入动脉阻控过久、导入动脉毁损或破裂等。针对不同情况采用了经髂动脉导入、导丝牵引技术、球囊扩张、主-单髂型移植物、不完全导入动脉阻断法、导入动脉修复重建等多种技术和处理方法。结果：41例导入动脉不良者均顺利完成手术；123例采用动脉不完全阻断法，未发生下肢缺血并发症；全组因导入动脉相关并发症死亡2例。结论：重视术前对导入动脉的评估，采用针对性的处理方法，有助于正确认识和克服导入动脉相关并发症带来的不利影响。     

腹主动脉瘤腔内隔绝术后迟发型远端内漏Ⅱ期腔内治疗

目的：探讨腹主动脉瘤（AAA）腔内隔绝术EVE后迟发型远端内漏的Ⅱ期腔内治疗方法的价值。方法：为3例AAA EVE3年以后迟发型远端内漏患者进行了Ⅱ期延伸移植物置入治疗，2例经双侧动脉切开、两侧各置入1枚延伸移植物，1例经腹膜后径路和股动脉径路完成3枚延伸移植物置入。结果：3例均应用了贯穿导丝牵张技术，延伸移植物置入完成后均将内漏消除。结论：Vanguard支架-人造血管系统的结构特点可能是导致远期远端内漏的原因；延伸移植物是治疗的有效方法。导丝牵张技术有助于手术成功并节约手术时间。