Endovascular repair for retrograde type A intramural hematoma with focal intimal disruption in descending aorta

BackgroundThis study aims to report the experience of a single center using thoracic endovascular aortic repair (TEVAR) to treat retrograde type A intramural hematoma (IMH) with focal intimal disruption (FID) in descending aorta.MethodsA total of 24 consecutive patients with retrograde type A IMH and complicated with FID in descending aorta underwent TEVAR in our center from 2015 to 2020. Their clinical data, imaging manifestation and follow-up results were retrospectively reviewed and analyzed.ResultsThe median age of patients was 57.9 years (range, 42–80 years) and 18 were men (75%). As the preoperative CT angiography showed, the 24 patients developed IMH complicated with different kinds of FIDs in descending aorta [5 had intramural blood pool (IBP), 15 had ulcer-like projection (ULP), 2 had penetrating atherosclerotic ulcer (PAU), and 5 had localized dissection]. Successful deployment of aortic stent graft was achieved in all patients. There was no endoleak, stent graft migration, spinal cord ischemia, stroke, or 30-day mortality observed after TEVAR. The median duration of follow-up was 30.0 months (range, 3–60 months). As the last follow-up CT angiography showed, most of the patients (23 in 24, 96%) had favorable aortic remodeling. The maximum hematoma thicknesses and maximum diameters of both ascending and descending aorta were significantly decreased. During follow-up, 1 patient developed retrograde type A aortic dissection (RAAD) and underwent open surgery 3 months after TEVAR. 1 patient died of lung cancer 2 years later. There was no aorta-related death observed.ConclusionsTEVAR provides a safe and effective treatment strategy for selected patients with retrograde type A IMH, and FID developed in descending aorta could be the possible treatment target. However, RAAD remains one of the most serious postoperative complications of concern.     

Open Repair of Acute Type A Intramural Hematoma in 3 Patients

Acute aortic syndrome encompasses classic aortic dissection and less common aortic phenomena, including intramural hematoma (IMH), a hemorrhage within the aortic media that occurs without a discrete intimal tear. We reviewed our experience with treating acute type A IMH to better understand this acute aortic syndrome. A review of our clinical database identified 1,902 proximal aortic repairs that were performed from January 2006 through December 2018; of these, 266 were for acute aortic syndrome, including 3 (1.1%) for acute type A IMH. Operative technique varied considerably. All IMH repairs involved hemiarch or total arch replacement. In all 3 patients, the IMH extended distally into the descending thoracic aorta. There were no operative deaths or major adverse events (stroke, paraplegia, paraparesis, or renal failure necessitating dialysis) that persisted to hospital discharge. Length of hospitalization ranged from 5 to 20 days. All 3 patients were alive at follow-up (range, 2–6 yr) and needed no aortic reintervention after their index or staged repairs. In our experience, repair of acute type A IMH was infrequent and could be either simple or complex. Despite our limited experience with this disease, we found that it can be repaired successfully in urgent and emergency cases. Following treatment guidelines for aortic dissection appears to be a reasonable strategy for treating IMH.     

主动脉右弓右降合并Stanford B型主动脉夹层的外科治疗

目的:总结主动脉右弓右降合并Stanford B型主动脉夹层的外科治疗经验。方法:3例右位主动脉弓、右位降主动脉、迷走左锁骨下动脉(迷走左锁骨下动脉型)合并Stanford B型主动脉夹层的患者经胸部右后外切口行胸降主动脉置换术、迷走左锁骨下动脉缝扎术。结果:3例患者均痊愈出院,住院天数7～10 d,无左上肢缺血症状及神经系统并发症。结论:主动脉右弓右降合并Stanford B型主动脉夹层患者行胸降主动脉置换术方法可行,临床疗效满意,术中判断后行迷走左锁骨下动脉缝扎术,可简化手术方式,但应避免术后左上肢缺血坏死。     

Note the descending aorta: predictors of postoperative major adverse aortic event in pure acute type A intramural hematoma

BackgroundIntramural hematomas (IMHs) may originate from small intimal tears. Although most surgeries for acute type A IMH are conventionally performed solely at the proximal aorta, regardless of the primary intimal tear site, the remnant aortic remodeling stays important during the follow-up period after surgery.MethodsForty-seven patients with “pure” acute type A IMHs who underwent surgery from January 2008 to December 2019 were retrospectively analyzed. Acute type A IMH in the entire region without penetrating aortic ulcer (PAU) and aortic dissection (AD), which upon initial computed tomography (CT), can be considered as an intimal tear site, was defined as “pure” type. The maximal diameter of the aorta, maximal thickness of the IMH, and hematoma thickness ratio (HTR) of the ascending and descending aortae were measured from the preoperative computed tomographic scan. The hematoma thickness index was defined as the HTR of the descending aorta divided by that of the ascending aorta. Major adverse aortic events (MAAEs) were defined as AD, rupture, or newly developed PAU and aortic death. Predictors for postoperative MAAEs were analyzed using preoperative computed tomographic findings.ResultsThe measurements of the descending aorta were larger and those of the ascending aorta were smaller in the MAAEs group, than in the corresponding other. The hematoma thickness index was significantly higher in the group with MAAEs, than in the group without; this variable was an independent predictor of MAAEs. During surgery, intimal tears were found in 16/47 (34%) patients. The hematoma thickness index was significantly smaller in the group with intimal tears than in the group without the tears. The aortic measurement appears to reflect the tear site.ConclusionsHematoma thickness index was an independent predictor of MAAE after acute type A IMH surgery. Long-term periodical follow-up with early reintervention may, therefore, be necessary to improve outcome in these patients. As the optimal treatment method is still controversial, inferring the location of the primary tear through the hematoma thickness index can be helpful in determining the treatment method.     

The usefulness of contrast-enhanced echocardiography in the diagnosis and management of intramural hematoma and aortic dissection: A case report

Contrast-enhanced transthoracic echocardiography (cTTE) plays an important role in the diagnosis of intramural hematoma (IMH) and aortic dissection (AD), and is also necessary for the adequate management from the assessment of findings. We hereby present an interesting case in which cTTE provides additional value over contrast-enhanced computed tomography (CT) in the diagnosis and the morphological characterization of IMH and AD. A 58-year-old man presented to the emergency department with intermittent chest pain. After emergency consultation, an enhanced CT scan showed an acute aortic intramural hematoma involving aortic arch and descending aorta. Nevertheless, the entry tear and false lumen flow direction were identified by cTTE, which suggested an acute type B AD.     

Pathologic variants of thoracic aortic dissections. Penetrating atherosclerotic ulcers and intramural hematomas

This article confirms the existence of two variants of acute aortic pathology, the penetrating atherosclerotic ulcer (PAU) and the intramural hematoma (IMH), which are radiologically distinct from classic aortic dissection. Table 4 reviews the characteristics distinguishing PAU from classic aortic dissection and IMH. We took as a matter of definition that classic aortic dissection involves a flap which traverses the aortic lumen. We defined PAU and IMH as nonflap lesions, with PAU demonstrating a crater extending from the aortic lumen into the space surrounding the aortic lumen. This categorization can be summarized with the expression, "no flap, no dissection." With these definitions made, re-review of the imaging studies for the present report identified 36 such lesions out of 214 cases originally read as aortic dissection. Therefore, these variant lesions accounted for over 1 out of 8 acute aortic pathologies. Besides confirming the existence of the conditions, PAU and IMH, as distinct radiographic lesions, this series strongly suggests that these two conditions constitute distinct clinical entities as well. Table 4 summarizes the clinical patterns of these two entities as apparent from the present study, and contrasts them with classic aortic dissections. In particular, the following observations, some of which are consonant findings in smaller series, can be made regarding the typical patient profiles of PAU and IMH from the present study: The patients with PAU and IMH are distinctly older than those with type A aortic dissection (74.0 and 73.9 versus 56.5 years, P = 0.0001). Although not statistically significant, PAU and IMH patients tend to be older than patients with type B aortic dissections as well. For PAU and IMH, unlike aortic dissection, the concentration in the elderly is manifested in a very small standard deviation of the mean age (see Fig. 13); these two entities, PAU and IMH, are essentially diseases of the seventh, eighth, and ninth decades of life. Patients with PAU and IMH are almost invariably hypertensive (about 94% of cases). The pain of PAU and IMH mimics that of classic aortic dissection, with anterior symptoms in the ascending aortic lesions and intrascapular or back pain with descending aortic lesions. Unlike classic dissection, PAU and IMH do not produce branch vessel compromise or occlusion and do not result in ischemic manifestations in the extremities or visceral organs. PAU and IMH are more focal lesions than classic aortic dissection, which frequently propagates for much or the entire extent of the thoracoabdominal aorta. PAU is uniformly associated with severe aortic arteriosclerosis and calcification, whereas classic dissection often occurs in aortas with minimal arteriosclerosis and calcification. PAU and IMH tend to occur in even larger aortas than classic aortic dissection (6.2 and 5.5 versus 5.2 cm, P = 0.01). PAU and IMH are strongly associated with AAA, which is seen concomitantly in 42.1% of PAU patients and 29.4% of IMH patients. PAU and IMH are largely diseases of the descending aorta (90% for PAU and 71% for IMH). Although our pathology data is limited, we do feel that an inherent difference in the histologic intramural level of the hematoma may underlie the pathophysiologic process that determines which patient develops a typical dissection and which develops an intramural hematoma. In particular, we feel that the level of blood collection is more superficial, closer to the adventitia, in IMH than in typical aortic dissection. This may explain why the inner layer does not prolapse into the aorta on imaging studies or when the aorta is opened in the operating room. This more superficial location would also explain the high rupture rates as compared to classic aortic dissection (Fig. 14, Table 3). We did find PAU and IMH to behave much more malignantly than typical descending aortic dissection. As seen in Figure 6, the rupture rate is much higher than for aortic dissection. Docume     

TEVAR for non‐aneurysmal thoracic aortic pathology

Objective : Management of penetrating atherosclerotic ulcers (PAU), intramural hematomas (IMH), and acute aortic dissections (AD) of the thoracic aorta remain controversial in the endovascular era. Methods : Between 2001 and 2007, patients with PAU (13 patients), and/or IMH (7 patients) were treated with thoracic endografts (TEVAR) in the endovascular suite under general anesthesia. Indications for intervention were intractable chest pain, expanding hematoma or contained rupture, or distal malperfusion. End‐points were early morbidity and mortality, incidence of endoleak, device‐related complications, and secondary interventions. Results : Of the 20 patients with a median age of 67 (25–83), 13 (65%) were men, 2 (10%) had contained aortic rupture, and 10 were symptomatic. One patient had carotid‐subclavian bypass debranching before endograft implantation. Ten patients had cerebrospinal fluid drainage. Mean length of aorta treated was 122.1 mm (range 36–300). All endografts were technically successful. Average blood loss was 50 mL. Thirty‐day mortality was 0%. Symptoms resolved in all patients; there were no neurologic complications. Average length of stay was 5 days. Mean follow‐up was 2.0 years (range 0.1–5.8). All patients remained asymptomatic. Three had early (<180 days) endoleaks: Two type II and 1 type I treated successfully with an additional cuff, which was the only patient requiring reintervention. Two patients had late (>180 days) endoleaks (type 2) observed with no aortic expansion. Two deaths at 5.4 and 5.8 years were due to severe aortic valve stenosis and metastatic lung cancer. Conclusion : TEVAR is a feasible option for repair of non‐aneurysmal thoracic aortic pathology with resolution of symptoms, no mortality, and no neurologic complications. © 2009 Wiley‐Liss, Inc.     

Different clinical features of aortic intramural hematoma versus dissection involving the ascending aorta

OBJECTIVES: The goal of this study was to test the hypothesis that the absence of direct flow communication through intimal tear in aortic intramural hematoma (AIH) involving the ascending aorta has different clinical impact on clinical course compared with typical aortic dissection (AD). BACKGROUND: Although emergent surgical repair has been applied for patients with proximal AIH as if it was typical AD, the natural history of proximal AIH is not known clearly yet. METHODS: Direct comparison of the clinical data of 81 patients with proximal AD and 24 patients with AIH was performed retrospectively. RESULTS: Patients with AIH were older (67 +/- 10 vs. 50 +/- 13, p = 0.001), and female gender was more predominant in AIH (19/24 vs. 29/81, p = 0.001). The development of mediastinal hemorrhage and pericardial and pleural effusion was more frequent in patients with AIH than it was in patients with AD. Although medical treatment was more frequently selected in the AIH group (75% vs. 15%, p = 0.001) due to old age and other associated medical diseases, the mortality rate with medical treatment was much lower in patients with AIH than it was in patients with AD (6% vs. 58%, p = 0.003). In follow-up imaging studies of 13 patients who survived AIH without surgical repair, seven patients showed complete resolution. Typical AD developed in three patients, and the other three patients showed focal AD only in the descending aorta. The two-year survival rate did not show significant difference (84% +/- 6% in AIH vs. 76% +/- 17% in AD, p = 0.47). CONCLUSIONS: Absence of continuous flow communication can explain a more favorable clinical course of AIH than for AD, and medical treatment with frequent imaging follow-up and timed elective surgery in cases with complications can be a rational option for patients with proximal AIH.     

Underlying aortic pathology and clinical health status determine success of endovascular stent-grafting for descending thoracic aortic disease.

Despite advances in medical and surgical treatment, acute as well as chronic diseases of the thoracic aorta are still associated with a high mortality. For the descending thoracic aorta, endovascular stent-graft placement competes with surgical therapy for clinical outcome. From July 1999 till December 2004, a total of 84 patients (64 +/- 14 years) with aortic disease of the descending thoracic aorta were treated. Nine patients had acute (AAD) and 35 chronic aortic dissection (AD), 16 had thoracic aortic aneurysms (TAA), 21 had penetrating aortic ulcer (PAU), and 3 patients had traumatic dissection (trans). Initial clinical status was assessed using the American Society of Anesthesiologists (ASA) classification. Fifty-three patients were in class 2, 16 in class 3, 8 in class 4, and 7 in class 5. Stent-graft placement was performed in the cardiac catheterization laboratory with the patient under general anesthesia. Technical success was obtained in 81/84 patients (96%). Within 30 days, seven patients (8%) died, four of them due to aortic rupture. In 14 patients, additional stent-grafts had to be implanted due to type I endovascular leakage (n = 5) or additional entry site adding up to a total of 107 implanted stent-grafts. During a follow-up period of 21 +/- 18 months, 17 additional patients died (22%). In 10 patients, death was disease- or procedure-related (13%). This long-term mortality depended on the underlying disease and was highest in the group with TAA (45%) followed by AAD (38%) and AD (18%). Patients in ASA class 4 and 5 had a significantly worse outcome. No aortic-related death occurred among patients with PAU or traumatic transsections. Overall, there was only one transient neurological deficit. Endovascular stent-graft placement has acceptable results in the treatment of patients with disease of the descending thoracic aorta. The outcome strongly depends on the underlying aortic pathology and the clinical health status of the patients. Randomized trials are necessary in order to establish the exact value of this new therapeutic option.     

Type A aortic intramural hematoma: clinical features and outcomes in Chinese patients

Background

The purpose of this study was to describe the clinical characteristics and clinical outcomes for Chinese patients with type A intramural hematoma (IMH).

Methods and Results

We studied 90 patients with Stanford type A acute aortic syndrome who presented to our institution from 1998 to 2005 and evaluated the presentation, management, and clinical outcomes of acute IMH by comparing these patients with those diagnosed with classical aortic dissection (AD). A total of 34 patients had IMH and they tended to be older (69.7 ± 12.4 versus 60.5 ± 16.2 years; p = 0.006). The development of pericardial effusion was more frequent in patients with IMH than in patients with AD. They were also less likely to receive surgery as compared to AD patients (26.5% versus 73.2%; p < 0.0001). Overall mortality of IMH was not significantly higher than that of classic AD (29.4% versus 21.4%; p = 0.45). For IMH patients, the mortality rate with medical treatment was 32%. Ten (40%) of the 25 medically treated patients developed adverse outcomes. However, no independent predictors of adverse outcomes were identified in the study. In follow‐up imaging studies of 15 patients who survived IMH without surgical repair, 14 patients showed complete resolution of IMH and 1 progressed into classical AD.

Conclusion

Acute type A IMH in Chinese patients showed a high mortality rate with medical treatment. It has a highly unpredictable course with no reliable clinical and anatomical predictors. Surgical therapy should be the treatment of choice for Chinese patients with acute IMH, especially those who are younger and have less comorbidities. © 2011 Wiley Periodicals, Inc.     

Endovascular stent-grafts for acute and chronic type B aortic dissection: comparison of clinical outcomes

Within the recent months, endovascular repair of aor- tic aneurysms has become a rather interesting alternative to patients considering open surgery. In the past, the proce- dure was typically and more solely reserved to a selected group of elderly patients with several co-morbidities. Currently, there are a number of ongoing trials that are com-     

Spontaneous echo contrast in the descending aorta in patients without aortic dissection: associated clinical and echocardiographic characteristics

The objective of the study was to evaluate the frequency, clinical and echocardiographic correlates of spontaneous echo contrast in the descending aorta in the absence of dissection. Prevalence of spontaneous echo contrast in the descending aorta in the absence of dissection, and its clinical and echocardiographic correlates were investigated in 1199 consecutive patients who underwent transesophageal echocardiography. Spontaneous echo contrast in the descending aorta was detected in 54 (4.5%) patients. Patients with spontaneous echo contrast in the descending aorta had an older age (60.6±8 vs. 40.6±14.2 years, P=0.0001), an increased prevalence of male gender (66.7 vs. 43.9%, P=0.001), an increased diameter of ascending aorta (4.2±1.0 vs. 3.3±1.1 cm, P=0.0001), an increased diameter of descending aorta (3.1±0.9 vs. 2.1±0.4 cm, P=0.0001), a higher prevalence of aortic wall calcification (9.3 vs. 0.5%, P=0.00001), complex plaque in the descending aorta (13 vs. 0.7%, P=0.0001), left ventricular dysfunction (7.4 vs. 2.1%, P<0.05), a lower incidence of severe aortic regurgitation (0 vs. 3.5%, P<0.05), a lower peak flow velocity in the descending aorta (28±9 vs. 51±21 cm/s, P<0.00001), and a lower maximal shear rate in the descending aorta (51±29 vs. 105±47 s⁻¹, P<0.00001) compared with patients without spontaneous echo contrast in the descending aorta. However, prevalence of atrial fibrillation, mitral valve disease, intracardiac spontaneous echo contrast and/or thrombus and embolic event were not different between patients with and without spontaneous echo contrast in the descending aorta (P>0.05). Shear rate, diameter of the descending aorta, aortic wall calcification, complex plaque in the descending aorta, absence of severe aortic regurgitation and male gender were independent variables of spontaneous echo contrast in the descending aorta. Spontaneous echo contrast in the descending aorta is a local and flow-dependent phenomenon related to aortic dilation, atherosclerosis, and decreased shear rates in the descending aorta. However, in this study, spontaneous echo contrast in the descending aorta was not found to be associated with embolic events.     

Hématome intramural de l’aorte thoracique : traitement médical ou chirurgie ?

Intramural hematoma (IMH) of the aorta is an uncommon entity. This disease shares many characteristics with acute aortic dissection. Treatment of IMH remains controversial. We report the case of a 58 years old man with hypertension disease who was admitted in emergency department with suspicion of acute aortic dissection. Transoesophageal echocardiography showed IMH involving the descending aorta which spred afterwards to the ascending aorta. Patient was treated medically and echocardiographic follow-up showed that aortic hematoma remains stable. Two years later, patient is alive and the last TEE reveals disappearance of hematoma in ascending aorta and decrease of it in descending aorta.     

Mild Thickening of the Aortic Wall: Subtle Intramural Hematoma?

Recently published criteria for the diagnosis of intramural hematoma (IMH) of the ascending aorta by transesophageal echocardiogram (TEE) include the presence of a crescent-shaped thickening of the aortic wall of more than 7 mm with an echolucent space. We report a patient whose clinical presentation suggested aortic dissection but whose TEE failed to meet the conventional criteria for such a diagnosis. TEE showed a uniform intimal thickening suspicious of IMH but less than 7 mm in thickness and with no echofree space. One week later, the patient developed frank aortic dissection. CONCLUSION: IMH can present with a subtle echo appearance. The diagnosis should not be totally discounted in the absence of a 7-mm crescentic wall thickness and an echofree space if the clinical presentation is suggestive of dissection.     

急性和慢性B型主动脉夹层介入疗效的对比研究

目的 比较急慢性期主动脉夹层行腔内隔绝术的临床疗效.方法 分析B型主动脉夹层住院患者的临床和影像资料,经股动脉置入覆膜支架封堵胸主动脉破裂口的临床特点、近期及远期疗效.结果 与慢性主动脉夹层组(慢性组)40例相比,急性主动脉夹层组(急性组)42例胸腔积液(16.7%比0,P=0.01),肢体或内脏缺血(23.8%比2.5%,P=0.01)发生率较高.与慢性组相比,急性组近期并发症发生率较高(38.1%比15.0%,P=0.02),出院后对患者进行了(18.7±17.3)个月随访,急性组远期并发症较慢性组发生率较高(21.4%比5.0%,P=0.03).Kaplan-Meier曲线提示两组长期生存率差异无统计学意义(P=0.38),急性组和慢性组5年生存率分别为90.0%、92.5%.慢性组长期无事件生存率显著高于急性组(P=0.04).结论 腔内隔绝术治疗B型主动脉夹层安全有效,但急性组较慢性组并发症增多.     

Impact of shear stress and atherosclerosis on entrance-tear formation in patients with acute aortic syndromes

Weak aortic media layers can lead to intimal tear (IT) in patients with overt aortic dissection (AD), and aortic plaque rupture is thought to progress to penetrating atherosclerotic ulcer (PAU) with intramural hematoma (IMH). However, the influences of shear stress and atherosclerosis on IT and PAU have not been fully examined. Ninety-eight patients with overt AD and 30 patients with IMH and PAU admitted to our hospital from 2002 to 2007 were enrolled. The greater curvatures of the aorta, including the anterior and right portions of the ascending aorta and anterior portion of the aortic arch, were defined as sites of high shear stress. The other portions of the aorta were defined as sites of low shear stress based on anatomic and hydrodynamic theories. Aortic calcified points (ACPs) were manually counted on computed tomography slices of the whole aorta every 10 mm from the top of the arch to the abdominal bifurcation point. IT was more often observed at sites of high shear stress in overt AD than in PAU (73.5 vs 20.0 %, P < 0.0001). Significantly more ACPs were present in PAU than in overt AD (18.6 ± 8 vs 13.3 ± 10, P = 0.007). The present study suggests that high shear stress and less severe atherosclerosis could induce the occurrence of an IT, thereafter progressing to overt AD, and that low shear stress and more severe atherosclerosis could proceed to PAU with IMH. These findings may help to identify the entrance-tear site.     

Different remodeling of descending thoracic aorta after acute event in aortic intramural hemorrhage versus aortic dissection

The natural healing process of medically treated aortic dissection (AD) and aortic intramural hemorrhage (AIH) developed in the descending thoracic aorta was compared to test the hypothesis that absence of intimal tear and flow communication in AIH may have different impact on the remodeling of the affected aorta after the acute event. In 25 patients with AD and 20 with AIH involving distal descending thoracic aorta stabilized with medical treatment, follow-up (mean 9 months) transesophageal echocardiography was performed to measure the maximal dimensions of aorta, true lumen, false lumen in AD, and abnormal wall thickening in AIH. The sex ratio, prevalence of hypertension, baseline maximal dimension, and longitudinal extent of the affected aorta did not show any significant difference in both groups. Patients with AIH were older than those with AD (63 +/- 10 vs 50 +/- 9, p <0.01). Disappearance of abnormal wall thickening with complete restoration of the aorta occurred in 70% (14 of 20) patients with AIH, which was significantly more frequent than in AD (8%, p <0.01). In AD, progressive dilatation of the aorta with continuous flow communication in the false lumen resulted in larger dimension of the aorta than in AIH (44 +/- 13 vs 35 +/- 7 mm, p <0.01). Absence of persistent flow communication resulted in a favorable remodeling process in AIH affecting distal descending aorta. This finding, along with different mean age in AIH and AD, may suggest that AIH is not just a precursor of overt AD but a distinct disease entity with different pathophysiology.     

Endovascular treatment of thoracic aortic disease: mid-term follow-up.

OBJECTIVE: The aim of this study was to evaluate the mid-term follow-up in a cohort of patients with acute or chronic descending aortic disease treated by stent-graft repair. BACKGROUND: Since 1999, endovascular stent-graft placement has been reported as an alternative treatment to surgical approach for a variety of thoracic aortic diseases; however, results beyond initial short-term follow-up are not widely available for the broad range of applications. METHODS: From March 2001, 43 consecutive patients with traumatic aortic transection (group A = 16) and complicated type B aortic dissection or aneurysm (group B = 27) underwent stent-graft implantation. All patients underwent computed tomography (CT) scan as preoperative assessment and in 26 a transesophageal echo (TEE) exam was performed. RESULTS: Technically successful stent-graft deployment was achieved in all patients. No patient required surgical conversion and no cases of paraplegia occurred. The overall in-hospital mortality was 9.3%. A residual endoleak (type II) was detected in one group B patient who was managed conservatively. The mean follow-up was 29 +/- 8 months (range 10-48 months). No patient died during late follow-up after hospital discharge. At 12 months, one patient (2.5%) who had stent graft repair of an aortic dissection developed an asymptomatic type I endoleak. Three asymptomatic patients with chronic dissection had a persistent retrograde perfusion of the thoracic false lumen via a distal tear(s) in the dissection septum. CONCLUSION: Our results of stent-graft treatment of complicated and uncomplicated diseases of the descending aorta confirms that this alternative to open repair is a safe, less invasive, and relatively low risk approach. Medium-term follow-up results suggest that it is effective and durable therapy with low associated mortality and morbidity rates.     

主动脉夹层54例16层螺旋CT表现特征及其解剖、病理基础

目的明确主动脉夹层的16层螺旋CT及其图像后处理（即三维重建）的影像表现特征与其解剖、病理基础的相关性。方法54例经临床影像证实的主动脉夹层患者（典型夹层42例,壁内血肿12例）行16层螺旋CT平扫、增强扫描及三维重建。重点观察和评价夹层真假腔、内膜片、内膜破口以及重要分支血管的受累情况。结果（1）42例夹层真假腔、内膜片、内膜破口的显示率分别为100％、100％、97．6％。夹层真假腔及内膜片呈螺旋形走行41例（97．6％）。左肾动脉及右髂总动脉最易受夹层累及,均为20例（47．6％）。（2）12例壁内血肿、无内膜撕裂,10例（83．3％）平扫表现为主动脉壁呈新月形或环形稍高密度影,2例（16．7％）呈低密度改变;增强扫描均无强化。12例壁内血肿合并穿通性溃疡9例（75％）。结论16层螺旋CT横断面及其三维图像,能快速、准确显示主动脉夹层的病理解剖改变,为临床提供精细信息,对治疗方案的选择具有重要临床实用价值。     

Accuracy of M-mode and two-dimensional echocardiography in the diagnosis of aortic dissection: an experience with 128 cases

The accuracy of combined M-mode and two-dimensional echocardiography in the diagnosis of aortic dissection was evaluated in 673 patients with a clinical suspicion of aortic dissection, over a six-year period. In 128 cases, the diagnosis of aortic dissection was confirmed by angiographic, tomographic (CT scan), or autopsy findings, or during surgery. Two echocardiographic features were found to support a diagnosis of aortic dissection: a dilation of at least one segment of the aorta (sensitivity 95%, specificity 51%) and a typical abnormal linear intraluminal echo corresponding to the intimal flap (sensitivity 67%, specificity 100%). This pathognomonic intimal flap was observed in 86 cases, of which three types could be distinguished: (1) a long oscillating flap (n = 15), (2) a long but minimally mobile linear echo which was duplicated and parallel to one or two aortic walls (n = 64), (3) a short, double linear image with a rapid systolic motion and high frequency oscillations. These features were found to have a high sensitivity in type I aortic dissection (88%), although in types II and III the sensitivity was much lower. In some cases, a fourth type of abnormal image could be detected: a small intraluminal echo moving in parallel to the aortic wall. This feature should be interpreted with caution since its predictive value for a positive examination was low (48%). Out of 23 cases in which the diagnosis of aortic dissection was suspected on the basis of this doubtful abnormal echo, it was confirmed in only 11 patients. The results in these 128 cases of aortic dissection indicate that two-dimensional echocardiography, which is easily performed at the patient's bedside, could take priority in investigations of this condition. It is extremely sensitive in the diagnosis of ascending aortic dissection, but much less so in the diagnosis of descending aortic dissection.