Aortic dissection surgery: experience of 78 cases.

From May 1990 to January 2001, 78 patients underwent surgery for aortic dissection, 68 (87%) of type A. Presentation was acute in 55 patients (71%). For type A dissection, in-hospital mortality was 13% (9 patients) and late mortality was 16%. For type B dissection, in-hospital and late mortality were both 30% (3 patients). The follow-up was complete and medical and imaging controls were performed periodically. Computerized axial tomography has shown persistence of distal aortic dissection in 18 patients, one of whom maintained dissection of the supraaortic trunks with false lumen thrombosis. Six patients maintained signs of dissection in the thoracic and abdominal aorta with patent false lumen. In another eight patients the false lumen was thrombosed. In 3 cases the dissection was located in the abdominal aorta. Two patients developed pseudoaneurysms of the thoracic aorta, one of whom was reoperated due to symptoms of dysphagia and chest pain, with angiographic signs of probable rupture of the aorta. Periodic imaging monitoring is essential, as it allows assessment of the extent of residual aortic disease and its evolution, with early detection of possible complications. This will enable prompt and safe action in those patients who may benefit from reoperation.     

Long-term predictors of descending aorta aneurysmal change in patients with aortic dissection.

OBJECTIVES: We sought to demonstrate the long-term natural course of descending aorta dilation after acute aortic dissection (AD) and identify early predictors for late aneurysmal change. BACKGROUND: Aneurysmal dilation of the aorta is a critical late complication in AD patients. METHODS: Contrast-enhanced computed tomography (CT) was performed during the acute phase in 100 AD patients, comprising 51 type 1 who underwent ascending aorta surgery and 49 type 3 AD patients. Clinical observation was conducted for 53 +/- 26 months, and CT was repeated for 31 +/- 27 months. RESULTS: Aneurysm (diameter > or =60 mm) occurred in 14.4%, 8.2%, 4.1%, and 3.1% of patients at the upper descending thoracic aorta (UT), mid descending thoracic aorta (MT), lower descending thoracic aorta (LT) and abdominal aorta (AA), respectively. Of 53 patients in whom CT was repeated for > or =2 years, the rates of aorta diameter enlargement at the UT, MT, LT, and AA levels were 3.43 +/- 3.66 mm/year, 3.21 +/- 2.70 mm/year, 2.62 +/- 2.19 mm/year, and 1.93 +/- 3.13 mm/year, respectively (p < 0.01), and aneurysm developed in 15 (28%). The initial false lumen diameter at the UT, the aorta diameter at the MT, and Marfan syndrome were independent predictors of late aneurysm. A > or =22-mm initial false lumen diameter at the UT predicted late aneurysm with a sensitivity of 100% and a specificity of 76%. The patients with initial UT false lumen diameter > or =22-mm (n = 42) showed higher event rate (aneurysm or death) than others (n = 58) (p < 0.001). CONCLUSIONS: The UT is the major site of late aneurysmal dilation. A large UT false lumen diameter on the initial CT portends late aneurysm and adverse outcome warranting early intervention.     

Midterm results of aortic diameter outcomes after thoracic stent-graft implantation for aortic dissection: a multicenter study.

PURPOSE: To evaluate aortic diameter outcomes after stent-graft implantation for aortic dissection in the descending thoracic aorta. METHODS: Fifty patients with type A dissection after ascending aortic surgery (n = 10), type B dissection (n = 34), or intramural hematoma (n = 6) underwent stent-graft repair in 3 centers. Thrombosis and aortic diameter were analyzed by computed tomographic angiography at different levels of the aorta before stent-graft implantation, at discharge, and at follow-up. Measurements were standardized. RESULTS: In all, 67 stent-grafts were implanted for acute (n = 18) and chronic (n = 32) dissection. Stent-graft placement was successfully performed with high technical success (100%) despite 4 major complications (iliac thrombosis in 2 cases, aortic rupture, and a type A dissection) in 3 (6%) patients. Complete thrombosis of the thoracic false lumen was observed in 42% and 63% of cases at discharge and at follow-up (mean 15 months), respectively. At follow-up, the diameters of the entire aorta (mean 5 mm, p < 0.05) and the false lumen (mean 11 mm, p < 0.0001) decreased. Diameters of the abdominal aorta remained stable in association with persistent false lumen perfusion at this level. Aortic diameter results were better in the subgroup of patients with intramural hematoma compared to patients with Marfan syndrome. Three early deaths unrelated to the stent-graft procedure occurred; 2 patients with partial thrombosis of the false lumen died in follow-up secondary to aortic diameter growth. CONCLUSION: Complete thrombosis of the false lumen by stent-graft coverage of the entry tear results in decreased diameter of the entire aorta. In patients with partial thrombosis of the false lumen, the aneurysm continues to enlarge.     

Value of transesophageal echocardiography combined with computed tomography for assessing repaired type A aortic dissection.

Thirty-two patients with repaired type A aortic dissection were examined by transthoracic echocardiography (TTE) (n = 32), transesophageal echocardiography (TEE) (n = 30), computed tomography (CT) (n = 29), or a combination of all 3, to assess course and complications as a function of the surgical procedure. The mean follow-up period was 55.7 months (range 3 to 132). Surgery consisted of a replacement of the ascending aorta in 25 patients (group 1) with extension to the transverse aorta in 7 (group 2). The transverse diameter of the aorta, the persistence of the false lumen, thrombus formation and flow dynamics in the false lumen were evaluated by TEE. Ten patients (31%) had a dilation in the initial ascending aorta (sinus of Valsalva aneurysm in 6 patients, and a false aneurysm in the other 4). Three of 4 patients with a proximal pseudoaneurysm underwent operation after TEE and CT evaluation. In the descending thoracic aorta, there was good agreement between TEE and CT scan determinations of transverse vessel diameter. Persistence of flow within the false lumen was significantly more frequent in patients with a dilated aorta (p < 0.05), whereas thrombosis was seen more often and false lumen less often in patients with nondilated aorta. No significant differences in vessel status or outcome were observed between the 2 groups, although this may have been due to the small size of group 2. TEE is thus a well-tolerated method for postoperative follow-up of type A aortic dissection whatever the type of surgery. For the upper ascending aorta, CT provided sufficient data.     

Aortic dissection after open repair of an infrarenal aortic aneurysm

INTRODUCTION:

A case of thoracic-abdominal dissection after open surgical exclusion of an infrarenal aortic aneurysm is presented.

CASE PRESENTATION:

A 62-year-old woman was diagnosed with an infrarenal abdominal aortic aneurysm with a rapid increase in maximal diameter. She underwent surgery for aneurysm exclusion by an end-to-end aortoaortic bypass with Dacron collagen (Intervascular; WL Gore & Associates Inc, USA). After 15 days, she was admitted to the emergency department with intense epigastric and lumbar pain. Computed tomography angiography with contrast revealed an aortic dissection with origin in the proximal bypass anastomosis and cranial extension to the thoracic aorta. The true lumen at the level of the eighth thoracic vertebra was practically collapsed by the false lumen. The celiac trunk, and the mesenteric and renal arteries were perfused by the true lumen. After the acute phase of the aortic dissection, surgical repair was planned. Two paths of false lumen were found – one at the thoracic aorta and the second in the proximal bypass anastomosis. Surgical repair comprised two approaches. First, a Valiant Thoracic stent graft (Medtronic Inc, UK) was implanted distal from the left subclavian artery, expanding the collapsed true lumen and covering the false and dissected lumen. Second, an infrarenal Endurant abdominal stent graft (Medtronic Inc) was implanted. This second device was complemented with an aortic infrarenal extension using a Talent abdominal stent graft (Medtronic Inc) in the infrarenal aortic neck to achieve a hermetic seal. The postoperative clinical course was uneventful, and her symptoms were completely resolved in six months.

CONCLUSION:

Arteritis must be taken into account in young patients with high inflammatory markers. Covered stents and endoprosthetic devices seem to be effective methods to seal the dissected lumen.     

Computed tomography of aortic intramural hematoma and thrombosed dissection

A retrospective study was undertaken to evaluate the appearance of the aortic wall on computed tomography for the purpose of developing criteria for differentiating acute aortic intramural hematoma from thrombosed false lumen seen in aortic dissection. Computed tomography angiography findings of the thoracoabdominal aorta in 23 patients with suspected intramural hematoma and 25 with thrombosed false lumen were reviewed. The more common features of an intramural hematoma were hyperattenuation of the aortic wall, wall thickness less than a quarter of the aortic diameter, intrinsic wall calcification, a lesion extending around the entire aortic circumference, and ulcer-like projections that may be precursors of intramural hematoma. Wall thickness less than a quarter of the aortic diameter, lesion extending around the entire aortic circumference, and ulcer-like projections were the most useful indicators for distinguishing intramural hematoma from the thrombosed false lumen in aortic dissection.     

Expanding false lumen in the abdominal aorta 5 years after endovascular repair of a type B aortic dissection: successful exclusion of 3 distal re-entry sites.

PURPOSE: To report endovascular treatment of an expanding aneurysmal false lumen several years after successful stent-graft deployment in the descending thoracic aorta for type B aortic dissection. CASE REPORT: A 54-year-old woman who had a stent-graft placed at the entry site of a type B aortic dissection 5 years prior presented with abdominal discomfort and palpable abdominal mass. Successful remodeling of the thoracic aorta was demonstrated by computed tomography; however, a false lumen aneurysm in the abdominal aorta had expanded from 4.8 to 6.5 cm and caused symptoms. She was successfully treated with 3 additional stent-grafts at 3 re-entry sites. Six months after the procedure, the false lumen aneurysm was completely excluded. CONCLUSIONS: Endovascular repair of the re-entry sites can prevent further expansion of false lumen aneurysm, which occurs in some patients with type B dissection treated with stent-grafts.     

Long-term prognosis of acute aortic dissection with medical treatment: a survey of 263 unoperated patients

Between 1973 and 1998, 263 patients with acute aortic dissection were medically treated only. They were divided into 4 groups: Stanford type A and B with open false lumen (open) or with early thrombosed false lumen (thrombosed). An event was defined as death by dissection or re-dissection. Gender, age, maximum diameter of dissected aorta and presence of shock at onset were examined as risk factors. In the open false lumen group, the presence of shock was associated with the event. During the chronic period, the diameter of the aorta was associated with prognosis in open type B dissection. The rate of event was higher in the open type A and B groups than in the thrombosed type A and B groups; however, there was no difference in the event-free rate between types A and B in patients surviving the acute period. The prognosis of medically treated dissecting aorta was not poor in patients with type B or with early thrombosed false lumen. The presence of shock at onset with open false lumen and the diameter of the aorta (> or =40 mm) in type B were significantly correlated with a poor prognosis.     

Clinical features of aortic dissection with early thrombosis of the false lumen]

There are cases of dissecting aortic aneurysm in which thrombotic formation occurs in the false lumen at an early stage, preventing dissection of the vessel wall and enlargement of the aneurysm. We studied such early thrombotic obliteration of false lumina in 12 (28.6%) of 42 patients with dissecting aortic aneurysm who underwent transesophageal two-dimensional echocardiography in the acute phase from June 1986 to October 1989. It was the first employment of a transesophageal approach at our hospital. In this study, we examined the clinical profiles of these patients as well as the usefulness of transesophageal two-dimensional echocardiography in establishing the diagnosis of dissecting aortic aneurysm and characterizing the disease. The patients were classified as Type I (2 patients) and Type III (10 patients; 6 Type IIIa and 4 Type IIIb) according to DeBakey's classification. The minimum and mean intervals from the onset of symptoms to transesophageal two-dimensional echocardiography were 1.5 hours and a mean of 38.2 hours, respectively. These results indicated that thrombotic obliteration of the false lumen had already occurred at a very early stage in some patients. The maximum diameter of the descending aorta was mean 37.6 mm with only 2 patients having that of 40 mm or more. Since left intrapleural hemorrhage was observed in these 2 patients (1 received emergent replacement of the descending aorta), enlargement of the aortic diameter may be indicative of unpredictable outcome, even in patients with early thrombotic obliteration of the false lumen. The long-term clinical course was favorable in all patients, including those who were treated surgically, over a mean follow-up period of 14.5 months.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endovascular stent-graft repair of aortic dissection

Between October 2000 and January 2002, 9 consecutive male patients with subacute or chronic aortic dissection underwent stent-graft placement. The indication for surgery was continuous pain or aneurysm development. One patient had a type A dissecting aortic aneurysm with a primary tear in the ascending thoracic aorta; the other 8 had type B dissection. Placement of an endovascular stent-graft was technically successful in 8 patients, and one underwent an open procedure for abdominal aortic fenestration. The entry site was sealed and the false lumen disappeared in 8 cases, and thrombosis of the false lumen was obtained. Rupture of an iliac artery dissecting aneurysm occurred in one patient 2 days after stent-graft placement; abdominal aortic fenestration with prosthetic replacement of the distal abdominal aorta was performed. One patient died of myocardial infarction 3 days after the stent-graft procedure. During a mean follow-up period of 7 months (1-16 months), one patient died of acute myocardial infarction at 11 months. It was concluded on the basis of these short-term results that endovascular repair of aortic dissection is a promising treatment, and abdominal aortic fenestration is a useful adjuvant procedure.     

False lumen patency as a predictor of late outcome in aortic dissection

Aortic dissection (AD) is a disease with a high-risk of mortality. Late deaths are often related to complications in nonoperated aortic segments. Between 1984 and 1996, we retrospectively analyzed the data of 109 patients with acute AD (81 men and 28 women; average age 61 ± 14 years). All imaging examinations were reviewed, and a magnetic resonance imaging examination was performed at the time of the study. Aortic diameters were measured on each aortic segment. Predictive factors of mortality were determined by Cox’s proportional hazard model, in univariate and multivariate analyses, using BMDP statistical software. Follow-up was an average of 44 ± 46 months (range 24 to 164). Actuarial survival rates were 52%, 46%, and 37% at 1, 5, and 10 years, respectively, for type A AD versus 76%, 72%, and 46% for type B AD. Predictors of late mortality were age >70 years and postoperative false lumen patency of the thoracic descending aorta (RR 3.4, 95% confidence intervals 1.20 to 9.8). Descending aorta diameter was larger when false lumen was patent (31 vs 44 mm; P = 0.02) in type A AD. Furthermore, patency was less frequent in operated type A AD when surgery had been extended to the aortic arch. Thus, patency of descending aorta false lumen is responsible for progressive aortic dilation. In type A AD, open distal repair makes it possible to check the aortic arch and replace it when necessary, decreases the false lumen patency rate, and improves late survival.     

Risk factors for descending aortic aneurysm formation in medium-term follow-up of patients with type A aortic dissection

BACKGROUND: After surgery to repair a type A aortic dissection, most late complications and mortality result from descending aorta-related problems. This study was performed to determine the risk factors leading to descending aortic aneurysm formation and late mortality in patients undergoing the type A aortic dissection operation. METHODS: The medical records of patients who survived the operation for type A aortic dissection between 1984 and 1998 were reviewed. There were 144 patients (95 men and 49 women), ranging in age from 24 to 78 years (mean age, 52 years). Most patients were acutely ill, 15 patients were in shock, and 54 patients had cardiac tamponade at the time of the surgical procedure. One hundred thirty-seven patients had ascending aortic replacement only, and of the other 6 patients 2 had hemiarch and 4 had total arch replacement using the elephant trunk technique. The aortic valve was replaced in 23 patients, resuspended in 100, and untouched in 21. Twenty-four risk factors were evaluated in statistical analyses for the prediction of descending aortic aneurysm formation and 3-year mortality. Risk factors were investigated using univariate and multiple logistic regression and survival analyses. RESULTS: The 3-year, 5-year, and 8-year cumulative survival rates were 96.2%, 89.1%, and 80.0%, respectively. The 3-year, 5-year, and 8-year cumulative survival rates, free from descending aortic aneurysm formation or descending aorta operation, were 74.7%, 58.6%, and 43.0%, respectively. Multivariate analysis confirmed that patent false lumen and initial descending aortic diameter were statistically significant risk factors for descending aortic aneurysm formation. CONCLUSIONS: The medium-term survival rate of patients who received operations for type A aortic dissection was satisfactory, despite the high incidence of descending aortic aneurysm formation. The intimal entry site over the aortic arch that was resected during the first operation could decrease the patency rate of a false lumen over the descending aorta. In the absence of a patent false lumen over the descending aorta, the chance of descending aortic aneurysm formation or operation is lessened, and the late survival rate is increased.     

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.     

Mobility of the Intimal Flap and Thrombus Formation in Aortic Dissection: A Transesophageal Echocardiographic Study

The mechanisms of the motion of the intimal flap and of thrombus formation in acute or chronic aortic dissection are not definitively elucidated. Transesophageal echocardiography seems to be a technique of choice to analyze the flow in the true and false lumina. Twenty-one consecutive patients were studied in order to define the mobility of the intimal flap, the color Doppler flow patterns, the presence of spontaneous echocardiographic contrast, and thrombus formation at different levels of the aorta. The results suggest that clotted false lumen is more often seen in chronic aortic dissection at the level of the descending thoracic aorta. However, thrombosed false lumen in the aortic arch is suggestive of a retrograde aortic dissection. In cases of complete obliteration of the false lumen, the differentiation between aortic dissection and aortic ectasia with mural thrombus may be extremely difficult.     

Rapid progression of discrete type A intramural hematoma: prevention of a "procedure-related" complication by intraoperative transesophageal echocardiography.

PURPOSE: To report a case illustrating the utility of transesophageal echocardiography (TEE) before planned stent-graft placement for chronic type B aortic dissection. CASE REPORT: A 64-year-old man with acute aortic syndrome and an 8-year-old interposition graft in the distal aortic arch for acute type B dissection was referred for dissection of the descending thoracic aorta down to the aortic bifurcation; the false lumen was dilated to 65 mm and was partially thrombosed. The ascending aorta showed discrete, eccentric, 4-mm wall thickening that was not considered clinically significant. Stent-graft closure of the entry tear in the proximal descending thoracic aorta was elected. However, as the endovascular procedure was about to commence, TEE showed striking eccentric thickening of the aortic wall of up to 18 mm. The endovascular procedure was stopped, as it was decided to urgently replace the ascending aorta. The next day, the patient underwent successful ascending aortic replacement and simultaneous antegrade stent-graft implantation over the descending thoracic aortic entry tear via the open aortic arch. The postoperative course was uncomplicated, and the patient was discharged 19 days after surgery. He remains well at 6 months after the procedure. CONCLUSIONS: Our case demonstrates that dissection of the ascending aorta may occur not only due to endograft-induced intimal injury, but may also occur due to underlying but undiagnosed or underestimated disease of the ascending aorta or arch. Besides procedural guidance, intraoperative TEE is a useful tool to detect such disease to avoid subsequent "procedure-related" complications.     

Acute and subacute dissection of the thoracic aorta: diagnostic importance of magnetic resonance tomography]

The purpose of this study was to retrospectively assess the reliability of ECG-triggered magnetic resonance imaging (MRI) for the diagnosis of acute and subacute thoracic aortic dissection and associated clinical epiphenomena. 67 patients were subjected to MRI; the diagnostic results were compared with morphological standards. 25 patients had type A, 12 patients type B dissection. In 30 cases a dissection was excluded. 17 patients with aortic dissection had acute onset of symptoms, 10 patients had subacute onset of symptoms. 17 patients revealed thrombosis of the false lumen, which was found in the descending aorta in 59% of the cases. Aortic regurgitation and pericardial effusion was most often associated with type A dissection (Table 1). Three patients were studied while on mechanical ventilation. Scan time for MRI ranged from 15 to 71 minutes with an average of 46 +/- 18 minutes. In this series no deleterious events were encountered related to MRI diagnostics. In contrast to previously published data using other noninvasive techniques the sensitivity of MRI was 100% for detecting a dissection in the ascending segment of the thoracic aorta. Moreover, the specificity of MRI for a dissection was 100% and thus higher than previously published data using transesophageal echocardiography. Sensitivity and specificity for detection and correct classification of type B dissection was 100% and 100% respectively (Table 2). In addition, MRI proved to be sensitive in detecting the formation of thrombus material in the false lumen of the ascending aorta (92%), the aortic arch (100%) and the descending segment (88%). Specificity for exclusion of suspected thrombus material even proved to be slightly higher with 100% in the ascending and descending aorta and 96.1% in the aortic arch (Table 3). The site of entry to a dissection was detected in 78%, with a sensitivity of 76% in the ascending and 92% in the descending aorta. The involvement of side branches in the dissecting process was identified in 60%. There were no false positive findings concerning side branch involvement. Aortic regurgitation and pericardial effusion were detected in 100% and 100%, respectively (Tables 1 and 2). MRI performed even in acute cases proved to be a atraumatic, safe and highly sensitive method to identify and classify acute and subacute dissections of the entire thoracic aorta. Limited patient access was not associated with an increased risk and mechanical ventilation did not interfere with MRI. These results may establish MRI as a valid and promising noninvasive technique to establish the diagnosis in patients with thoracic aortic dissection.(ABSTRACT TRUNCATED AT 400 WORDS)     

Transition from classic aortic dissection to aortic intramural hemorrhage--a case report

A 64-year-old man was hospitalized with chief complaints of chest and back pain. A diagnosis of Stanford type A aortic dissection with a false lumen extending from the ascending to the descending aorta was made based on the results of computed tomography (CT). A CT obtained the following day showed resolution of the false lumen and increased brightness of the aortic wall, typical of aortic dissection with intramural hemorrhage. Although previous studies have described a gradual transition from aortic intramural hemorrhage to aortic dissection with a false lumen, there are no reports of the transition from an aortic dissection with a false lumen to the intramural hemorrhage type of aortic dissection. This patient is of interest when considering the pathogenesis of aortic dissection with intramural hemorrhage and the relationship between the intramural hemorrhage and false-lumen types of aortic dissection.     

Follow-up of patients undergoing surgery for aortic dissection: evaluation with transesophageal echocardiography]

BACKGROUND. Transesophageal echocardiography (TEE) is a useful means in the diagnosis of acute aortic dissection (AD), owing to its very high sensibility and specificity. In this study, TEE was performed to assess post-surgical evolution. PATIENTS. Between 1982 and 1991, 119 pts. were operated on in our institution for AD (De Bakey I and II type): 87 pts. underwent replacement of the ascending aorta with a composite tubular graft bearing a mechanical valve; 26 had a simple tubular graft and 6 had aortic reconstruction. Sixty-eight of 72 discharged pts. were followed for up to 9.5 years (mean 4.5 +/- 2.6). Nine years after surgery actuarial survival of discharged pts. was 75%. Seven pts. died after a mean period of 3.4 years from surgery: only one died from postoperative complication (dehiscence of proximal anastomosis), none for aortic rupture distal to the graft. TEE was performed in 32 of these pts. and in other two operated on elsewhere, after 4.4 +/- 2.7 years from surgery; before the operation, type I AD was diagnosed in 23 pts. and type II in 11 pts. RESULTS. In 10/11 pts. with type II AD the aortic arch and the descending aorta looked normal; in one patient a localized intimal flap was found up to the arch. The descending aorta diameter was somewhat higher than in normal subjects (25.2 +/- 2.8 vs 21.9 +/- 3.7 mm), but in only one case was it beyond 2DS (32 mm). In all type I pts. an intimal flap persisted distal to the graft, along the whole thoracic aorta. Within the false lumen a flow was detected by color-Doppler in 14/23 pts. (61%), and spontaneous echo-contrast was noted in 14 pts. (61%). A thrombus was observed in 7 pts. (30%) and it was generally localized; in only one case it was extensive with total obliteration of the false lumen. In 16 pts. (70%) communications between the two lumina were found. The descending aorta diameter ranged from 25 to 53 mm, and mean value was higher than in normal subjects (34.2 +/- 6.2 vs 21.9 +/- 3.7 mm). CONCLUSIONS. In most pts. with type II AD, surgery can be a definitive treatment, as the remaining aorta keeps to normal size and appearance. In type I AD, operation is only palliative, as the dissection persists: the false lumen is often perfused through one or more communications with the true lumen and seldom its obliteration is noted. The persistence of dissection does not necessarily seem to be an ominous finding, as the survival of the study population was high and no patient died from aortic rupture. Nevertheless, long-term prognosis can be affected by aorta dilation that often (but not always) follows the persistence of wall dissection. For its high reliability, easy feasibility and low cost TEE is a very useful method for following up patients operated on for AD and for detecting those who are at higher risk of aortic rupture because of lumen dilation.     

管腔内支架人工血管治疗急性胸降主动脉夹层动脉瘤

目的 探讨管腔内支架替代传统手术治疗急性胸降主动脉夹层动脉瘤的可行性及效果.方法 从2003年6月至2005年6月,12例急性胸降主动脉夹层动脉瘤患者接受管腔内支架人工血管治疗.结果 12例患者无死亡.共放支架12支,胸降主动脉受压夹层真腔全部恢复正常管径,无中转手术.术后3个月、1年随访,行CTA检查未发现与支架有关的并发症.结论管腔内支架人工血管治疗急性胸降主动脉夹层动脉瘤是一种有效的治疗方法.