AJR Get Involved! Join ARRS Today
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Czermak, B. V.
Right arrow Articles by Jaschke, W. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Czermak, B. V.
Right arrow Articles by Jaschke, W. R.
Social Bookmarking
 Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Hotlight (NEW!)
Right arrow
What's Hotlight?
AJR 2002; 179:337-345
© American Roentgen Ray Society


Placement of Endovascular Stent-Grafts for Emergency Treatment of Acute Disease of the Descending Thoracic Aorta

Benedikt V. Czermak1, Peter Waldenberger1, Reinhold Perkmann2, Michael Rieger1, Iris E. Steingruber1, Ammar Mallouhi1, Gustav Fraedrich2 and Werner R. Jaschke1

1 Department of Radiology, Kurt Amplatz Center, Leopold-Franzens Medical School and University Hospital Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria.
2 Department of Vascular Surgery, Leopold-Franzens Medical School and University Hospital Innsbruck, 6020 Innsbruck, Austria.

Received July 19, 2001; accepted after revision February 11, 2002.

 
Presented at the annual meeting of the Radiological Society of North America, Chicago, November 2000.

Address correspondence to B. V. Czermak.


Abstract
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
OBJECTIVE. The aim of this study was to evaluate the feasibility, safety, and effectiveness of endovascular stent-graft placement for the emergency treatment of acute descending thoracic aortic disease.

MATERIALS AND METHODS. From January 1996 through November 2001, 18 patients underwent emergency endovascular stent-graft placement for various types of acute descending thoracic aortic disease. Five patients had Stanford type B aortic dissection, six had traumatic ruptures of the thoracic aorta, five had ruptured aortic aneurysms, and two had penetrating atherosclerotic aortic ulcers. All patients presented with life-threatening symptoms requiring treatment with stent-grafts from the emergency kit. All were at high surgical risk due to serious comorbidities. The efficacy of the procedure was assessed at follow-up studies before discharge and at 3, 6, and 12 months after intervention and yearly thereafter.

RESULTS. The primary technical success rate was 78%. Four patients had primary perigraft leaks. The secondary technical success rate was 83%. One patient died 20 hr after intervention from stent-graft—related causes. Follow-up studies revealed stent-graft migration in one patient. Progression of disease was observed in one patient treated for dissection and in both patients treated for penetrating ulcers. One patient died 7 months after intervention of unknown reasons; all other patients are alive. The mean follow-up time was 17.4 months (range, 0-38 months).

CONCLUSION. Emergency repair of acute descending thoracic aortic disease with stent-graft placement can be successfully accomplished and may be a promising alternative to open-chest surgery, especially in patients at high risk.


Introduction
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
The traditional treatment for most patients with diseases of the descending aorta is surgical intervention with graft interposition [1]. In elective surgical procedures performed by experienced cardiothoracic and vascular surgeons in patients who are excellent surgical candidates, the surgical mortality rate in thoracic aortic aneurysm repair is relatively low (<=15%) [2]. However, the operative mortality rate is nearly 50% in patients requiring emergency treatment [3,4,5]. The decision for surgical repair becomes increasingly complicated if patients have serious coexisting illnesses such as chronic obstructive pulmonary disease, coronary ischemia, renal failure, or multiorgan trauma [6].

Dake et al. [7] reported excellent short-term and acceptable medium-term results with transcatheter stent-graft treatment of a descending thoracic aortic aneurysm in patients at high risk. Results of several clinical studies [8,9,10,11,12,13] have shown successful emergency repair of acute thoracic aortic disease by endovascular stent-grafting. Compared with elective endovascular repair of thoracic aortic lesions, emergency stent-grafting is more demanding in several respects. Because many emergency procedures must be performed outside regular hospital hours, a team of radiologists, vascular surgeons, anesthesiologists, operating room nurses, and radiographers who can quickly set up the imaging, surgical, and interventional equipment should be on call around the clock. An emergency kit containing stent-grafts of various designs, diameters, and lengths must be on hand. Moreover, success is dependent on the skill and expedience of the operating team, because the prosthesis from the emergency kit does not always have the optimum size or design or both, whereas in elective procedures, individually designed and custom-fabricated grafts can be used.

We have previously reported our preliminary results in endovascular treatment of acute and chronic Stanford type B dissection in seven patients, three of whom were treated on an emergency basis [8]. The purpose of our retrospective study, which comprised 18 patients including the three patients treated as emergencies from our previous study, was to evaluate the feasibility, safety, and effectiveness of endovascular stent-graft placement for emergency repair of acute descending thoracic aortic disease performed immediately after diagnostic workup. We present and evaluate the results of emergency endovascular treatment for a heterogeneous spectrum of acute thoracic aortic abnormalities including traumatic rupture of the thoracic aorta, ruptured aortic aneurysm, Stanford type B dissection, and penetrating atherosclerotic aortic ulcer. We also discuss the advantages and disadvantages of different stent-graft designs. Furthermore, we show the benefit of additional unenhanced helical CT scans of the stent-graft for evaluating time-related changes in shape, position, and structure of the stent-graft during follow-up, and we will present additional statistical data on the patients in whom the left subclavian artery was crossed with the proximal portion of the stent-graft to extend the proximal and distal neck "landing zone."

The results of our study are promising and compare favorably with mortality rates in previously published reports on emergency surgery for acute aortic disease [3,4,5].


Materials and Methods
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
Patient Selection
From January 1996 through November 2001, 54 patients (46 men, eight women) with an age range of 19-80 years (mean, 62 years) underwent endovascular stent-graft placement for descending thoracic aortic disease.

Eighteen patients (all men) presented with life-threatening symptoms, necessitating emergency repair. Their age range was 19-81 years (mean, 55 years). They were not considered candidates for surgery because of serious coexisting illnesses, including severe chronic obstructive pulmonary disease, symptomatic coronary artery disease, hypertension, diabetes, severe obesity, or multiple trauma. The patients were classified as class 3 (severe systemic disease with definite functional limitation, n = 9) or class 4 (severe systemic disease that is a constant threat to life, n = 9) according to the American Society of Anesthesia physical status [14]. They presented with a heterogeneous mix of acute descending thoracic aortic abnormalities. Table 1 lists the baseline clinical characteristics of the patients.


View this table:
[in this window]
[in a new window]

 
TABLE 1 Patient and Stent-Graft Characteristics

 

Patients 2, 3, 11, 12, and 13 (n = 5) had acute Stanford type B aortic dissection. The dissections occurred spontaneously, with the exception of patient 13, in whom a severe thoracic trauma was the initiating event. All dissections extended into the abdominal aorta (n = 1) or the iliac arteries (n = 4), and the entry site in all was within 2 cm of the origin of the left subclavian artery. All five patients presented with life-threatening symptoms necessitating acute treatment and had severe chest or abdominal and back pain. Patients 2, 3, 11, and 13 showed dynamic compromise [15, 16] of visceral arteries involving the celiac (n = 2), the superior mesenteric (n = 2), or the left renal arteries (n = 3). Patients 3 and 11 showed ischemic obstruction of the left iliac artery caused by both static and dynamic components. Patient 12 had intractable pain despite aggressive medical therapy.

Patients 1, 4, 8, 14, 16, and 18 (n = 6) presented with traumatic rupture of the thoracic aorta with the injury limited to the isthmus. In addition, all of them had sustained multiple injuries to the head, chest, abdomen, and skeleton. CT scans obtained at admission showed severe mediastinal hematoma in all six patients. In addition, the scans revealed a large pseudoaneurysm (diameter, 3.2 cm) in patient 8, which was at risk for rupture, and a hemothorax and pericardial effusion in patient 14. In patient 16, the aortic rupture had to be repaired before transabdominal surgical treatment of a ruptured left hemidiaphragm (Fig. 1A,1B,1C,1D), and in patient 1, before major orthopedic surgical therapy of an unstable fracture of T8. Because of the multiple injuries and the need for full ventilatory support, all six patients were at high surgical risk.



View larger version (142K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 1A. 41-year-old man (patient 16) with traumatic rupture of thoracic aorta. CT scan obtained before transfemoral placement of stent-graft shows false aneurysm (arrowheads) and mediastinal hematoma. In addition, peritoneal fat (arrows) is seen in left hemithorax because of ruptured left hemidiaphragm.

 


View larger version (127K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 1B. 41-year-old man (patient 16) with traumatic rupture of thoracic aorta. CT scan obtained after stent-graft placement shows complete exclusion of false aneurysm. Adequate blood flow is seen in descending thoracic aorta.

 


View larger version (110K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 1C. 41-year-old man (patient 16) with traumatic rupture of thoracic aorta. Angiogram obtained before intervention shows isthmic pseudoaneurysm (solid arrows). Mild narrowing of left lateral wall of left common carotid artery is caused by vasospasm (arrowheads). Left vertebral artery arises from aortic arch (open arrows).

 


View larger version (111K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 1D. 41-year-old man (patient 16) with traumatic rupture of thoracic aorta. Angiogram obtained after intervention shows complete exclusion of pseudoaneurysm. Noncovered portion of stent-graft is placed across origin of left subclavian artery. Blood flow in artery (arrows) remains intact.

 

Patients 6, 7, 9, 15, and 17 (n = 5) underwent emergency stent-grafting for acute rupture of a thoracic aortic aneurysm. They had severe chest, midthoracic, and back pain. In patient 7, the aneurysm had ruptured into the pleural space, whereas in patients 6, 9, 15, and 17, it had ruptured into the mediastinum. Patient 6 presented with hemoptysis from an aortobronchial fistula.

In patients 5 and 10 (n = 2), emergency stent-grafting was necessary because of a penetrating ulcer of the descending aorta. Both patients were admitted with collapse associated with central chest pain and dyspnea. Patient 5 had hemoptysis. In patient 10, a CT scan obtained at an outside hospital before transfer to our department showed a hemorrhagic pleural effusion. Preoperative CT performed at our department showed a substantial increase in the size of the effusion.

In each patient the decision for emergency repair by endovascular stent-grafting was made by a team including anesthesiologists, cardiovascular surgeons, and interventional radiologists. Complete written informed consent was obtained from each patient with the exception of those patients (n = 7) who had been treated with intubation before admission.

Diagnostic Workup
In each patient, we performed enhanced helical CT with three-dimensional (3D) vascular reconstruction immediately after admission and diagnostic arteriography using a calibrated catheter at the time of the stent-graft insertion. Helical CT examinations were performed using a scanner (HiSpeed Advantage; General Electric Medical Systems, Milwaukee, WI) with a standardized protocol. After we obtained an anteroposterior scout image, we defined a volume of interest that extended from the level of the carotid bifurcation to the level of the external iliac artery. Scans were obtained using 120 mL of iopromide (Ultravist; Schering, Berlin, Germany) administered IV at a concentration of 300 mg I/mL, a flow rate of 3 mL/sec, and a scanning delay of 25 sec. A collimation of 5.0 mm, table speed of 10 mm/sec (pitch, 2:1), and tube current of 120 kVp were used. Helical CT scans and arteriograms were obtained to assess the length and diameter of the aortic abnormality and "landing zones." In addition, these studies provided the needed information about the anatomic relationships between the abnormality and important aortic branches, especially the left subclavian artery, the celiac artery, and the superior mesenteric artery, and about the diameter and tortuosity of the aorta and the iliac and femoral arteries.

Stent-Grafts
The dimensions of the stent-grafts were determined on the basis of the findings on contrast-enhanced helical CT and arteriography. Whereas diameter measurements were obtained from CT scans, length measurements were obtained from angiograms using a calibrated catheter. Stent-grafts were selected according to the aortic diameter and length of the lesion (Table 1). In all patients, standard stent-grafts from the emergency kit were used. The tube devices used were the following: Vanguard (Boston Scientific, Natick, MA; three patients) and Talent (World Medical, Sunrise, FL; 15 patients). In one patient an Excluder stent-graft (W. L. Gore, Flagstaff, AZ) to repair a primary endoleak type I was implanted 1 day after primary intervention, during which seven patients received only one stent-graft each, seven received two stent-grafts each, and four patients needed three or more grafts each. Proximal diameters of the endovascular devices were from 24 to 46 mm (mean, 37 mm), distal diameters were from 24 to 44 mm (mean, 35 mm), and their lengths were from 50 to 130 mm (mean, 114 mm). Additional characteristics of the stent-grafts were described previously [8, 17].

Technique
All procedures were performed in an interventional radiology suite by a team of vascular surgeons and interventional radiologists, using general anesthesia administered by tracheal intubation and mechanical ventilation. The patient was supine, and the thorax, abdomen, and pelvis were prepared in a sterile manner for femoral arteriotomy and also for possible conversion to a surgical emergency intervention, if necessary. The arterial access site for introducing the stent-graft was the right (n = 12) or the left (n = 3) femoral artery. We chose the less tortuous of these two arteries or that with the wider lumen. In three instances, the right (n = 2) or left (n = 1) external iliac artery had to be used because of the diameter or length of the introducing sheath.

A surgical cutdown was performed to expose the femoral or external iliac arteries, which was followed by a transverse arteriotomy at the site in which the stent-graft was inserted. After identification of the aortic abnormality and the most appropriate angiographic projection to display the involved aortic segment, metallic markers (25-cm-long needles or clamps) were placed on the patient's skin to mark the proximal and distal levels of the abnormality and the level of the left subclavian artery or the visceral arteries, if necessary. The upper and lower ends of the region of stent-graft placement were marked with angiographic guidance. Next, the delivery system was introduced and positioned at the proximal end of the aortic abnormality. Care was taken to position the proximal end of the endoprosthesis above the aortic abnormality. In four patients, the origin of the left subclavian artery had to be crossed with the uncovered proximal portion of the stent-graft (Talent, FreeFlo design), whereas in seven patients, it was necessary to cross the left subclavian artery with the covered proximal portion of the graft to extend the proximal anchoring zone (Table 2). During deployment, systolic blood pressure was titrated to less than 70 mm Hg by infusion of a sodium nitroprusside solution to ensure precise positioning and prevent downward migration of the graft. Additional technical aspects of stent-graft deployment such as sizing of the graft, technical details of stent-graft insertion, and primary interventional therapy of endoleaks type I and II were described previously [7,8,9, 17,18,19].


View this table:
[in this window]
[in a new window]

 
TABLE 2 Emergency Endovascular Treatment in 18 Patients with Acute Thoracic Aortic Disease

 

Follow-Up Protocol
CT was performed before patients were discharged and at 3, 6, 12, and 24 months after intervention and yearly thereafter. A panel of blood tests to determine complete blood cell count, C-reactive protein level, electrolyte level, creatinine level, blood urea nitrogen level, prothrombin time, partial thromboplastin time, and erythrocyte sedimentation rate and clinical examinations were performed on the same schedule. Hospitalization and short- and long-term complications were registered.

At follow-up, in addition to the standardized preoperative CT protocol, an additional unenhanced helical CT scan was obtained. The volume of interest was limited to the stent, and a collimation of 3 mm, table speed of 6 mm/sec (pitch, 2:0), and a tube current of 140 kVp were used. A standard algorithm was used with secondary augmented reconstruction (field of view, 25 cm).

In all patients in whom the left subclavian artery had to be crossed with the stent-graft, the patency of the artery was evaluated. In addition, blood pressure in the left upper extremity was compared with that in the right one before intervention and postoperatively. Arterial blood pressure values were tabulated in SPSS for Windows version 10.0 (Statistical Package for the Social Sciences, Chicago, IL). The Shapiro-Wilk test revealed that the data were distributed normally. Further statistical evaluation was done by paired t tests. The significance level was set at a p value of less than 0.05. In addition, oscillographic measurements were taken using a pulse-volume recorder. The pulse-volume recorder is a segmental plethysmograph used to monitor extremity pulsatility as an indirect reflection of blood flow. The pulse-volume recorder uses air-filled cuffs placed at different levels around the extremity. Momentary volume changes of the limb are detected by pressure changes in the cuffs and recorded on a strip recorder as arterial pulse contours. The pulse-volume-recorder contour closely corresponds to direct intraarterial pressure waveform recordings at that level. The pulse-volume—recorder tracings supplement Doppler segmental limb pressures and allow assessment of perfusion of the forearm and digits, at which the Doppler unit cannot easily measure pressures. The normal pulse-volume recording becomes progressively flattened and prolonged with increasing stenosis [20]. Endoleaks were classified using the system developed by White et al. [21,22,23]. Migration of the stent-grafts was evaluated by comparing 3D volume-rendering reconstructions of the grafts in different planes. In patients treated for dissections type B, clot formation in the false lumen was evaluated, and volume changes in the false and true lumina were monitored. Measurements were performed by using the summation-of-area technique [24, 25].


Results
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
The intraoperative mortality rate was 0%. Patient 9 died postoperatively on day 1. Patient 5 died of unknown causes 7 months after the procedure. All other patients are alive. The mean follow-up time was 17.4 months (range, 0-38 months). Long-term follow-up studies, however, will continue to be performed every 12 months. The primary technical success rate was 78%, and the secondary technical success rate was 83%. (Table 2). Postoperative CT showed no endoleak type II but showed primary endoleak type I in three patients. Patients 9 and 14 had proximal endoleaks type I (attachment zone) because the proximal end of the stent-graft could not be adapted to the curved aortic contour. Patient 9 died of an aortobronchial fistula 20 hr after the intervention, whereas in patient 14, successful secondary endoluminal repair was possible by insertion of an additional custom-fabricated Excluder stent-graft (Fig. 2A,2B). In patient 6, a distal leak type I into the aneurysmal sac could not be treated during primary emergency intervention because only two appropriate stent-grafts were on hand. A third stent was implanted 2 days later, but it was still impossible to seal off the leak completely. Placement of additional stents was also impossible because of the close relationship of the distal aneurysm neck to the origin of the superior mesenteric artery. However, follow-up scans showed thrombosis in the area of the aortic rupture, despite the small distal leakage. Patient 6 is under close surveillance. Follow-up studies are performed at intervals of 6 months. Patient 2 was readmitted with chest and back pain 1 month after discharge. The dissection had propagated into the ascending aorta and required surgery to replace the ascending aorta and the hemiarch; the stent-graft was left in situ and did not interfere with the surgical procedure. Details were described previously [8].



View larger version (126K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 2A. 30-year-old man (patient 14) with traumatic rupture of thoracic aorta. Oblique transverse multiplanar volume reconstruction displayed in average mode of distal thoracic aortic arch obtained after intervention shows primary proximal attachment zone endoleak type I (arrows). Stent-graft is not flexible enough to apply to curve of distal arch.

 


View larger version (117K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 2B. 30-year-old man (patient 14) with traumatic rupture of thoracic aorta. Oblique transverse multiplanar volume reconstruction displayed in average mode of distal thoracic aortic arch obtained after insertion of additional, more flexible stent-graft shows complete sealing of endoleak.

 

No neurologic complications, in particular spinal cord ischemia, were observed. In 11 patients, the stent-graft crossed the ostium of the left subclavian artery. No patients developed signs of upper extremity ischemia or neurologic complications. In all patients in whom the left subclavian artery had to be crossed with the covered portion of the stent-graft, postoperative angiography and duplex scanning during follow-up showed adequate collateral retrograde blood flow via the left vertebral artery.

Before intervention, we noted no significant difference in systolic (p = 0.177) and diastolic (p = 0.356) blood pressures when comparing blood pressure in the left upper extremity with that of the right. However, systolic and diastolic blood pressures in the left upper extremity decreased significantly compared with those in the right upper extremity (systolic, p < 0.001; diastolic, p = 0.036) after crossing the left subclavian artery with the covered portion of the stent-graft. In the right upper extremity, the mean systolic blood pressure was 148 mm Hg (range, 120-200 mm Hg; SD, 29) and the mean diastolic pressure was 84 mm Hg (range, 65-106 mm Hg; SD, 14), whereas in the left upper extremity, mean systolic pressure was 123 mm Hg (range, 90-170 mm Hg; SD, 30) and mean diastolic pressure was 81 mm Hg (range, 65-105; SD, 14). Oscillographic measurements showed substantial decrease of the amplitude. In the patients in whom the left subclavian artery had to be crossed with the uncovered portion of the graft, arterial blood flow remained intact, and no substantial difference in blood pressure was observed when comparing the blood pressure of the left upper extremity with that of the right upper extremity.

Stent-graft migration was observed in patient 3, who had received two grafts. The 3D volume-rendering—reconstruction images of the grafts obtained during follow-up showed alterations in the position of the distal graft, which led to disconnection at 24 months after primary repair. To prevent mechanical instability and aneurysm formation in the area between the disconnected stent-grafts, we decided to perform secondary endovascular repair by the successful insertion of an additional stent-graft (Fig. 3A,3B,3C).



View larger version (83K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 3A. 63-year-old man (patient 3) with acute Stanford type B dissection. Three-dimensional volume-rendering reconstruction image of thoracic stent-graft obtained after intervention shows stent-graft in true lumen.

 


View larger version (73K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 3B. 63-year-old man (patient 3) with acute Stanford type B dissection. Three-dimensional volume-rendering reconstruction image of thoracic stent-graft obtained 24 months after intervention shows expected expansion, resulting in enlargement of true lumen during follow-up. Instability in short overlapping area resulted in disconnection (arrows). Short overlapping area increases risk of migration and caused disconnection.

 


View larger version (88K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 3C. 63-year-old man (patient 3) with acute Stanford type B dissection. Three-dimensional volume-rendering reconstruction image of thoracic stent-graft obtained after successful secondary interventional repair shows that endoluminal therapy was possible by insertion of additional stent-graft.

 

In all patients treated for Stanford type B dissection, closure of the entry tear (Fig. 4A,4B) and thrombosis of the false lumen could be achieved with the exception of patient 2. In those patients who had underperfusion of visceral arteries due to the dissection (n = 4), endovascular stent-graft placement restored adequate blood flow to the compromised visceral branches (Fig. 5A,5B), which was confirmed on postoperative arteriography. No additional maneuvers such as aortic fenestration or insertion of uncovered visceral artery stent-grafts were necessary. In both patients with ischemic obstruction of the iliac artery, endarterectomy and fixation of the distal intimal flap, performed by our team of vascular surgeons, restored adequate blood flow to the lower extremities. In all patients, flow-up imaging studies showed shrinkage of the false lumen and increase of the true lumen, which were due to expansion of the stent-graft. None of the patients treated for traumatic rupture of the thoracic aorta developed complications during follow-up (Table 2).



View larger version (145K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 4A. 70-year-old man (patient 12) with acute Stanford type B dissection. Angiogram obtained before intervention shows blood flow in true and false lumina (arrowheads) of thoracic aorta.

 


View larger version (153K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 4B. 70-year-old man (patient 12) with acute Stanford type B dissection. Angiogram obtained after stent-graft deployment shows complete closure of entry site (arrow).

 


View larger version (146K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 5A. 45-year-old man (patient 11) with acute Stanford type B dissection. Angiogram obtained before intervention shows "floating viscera sign" representing severe underperfusion of visceral arteries because dissection spares vessel origin, but dissection flap appears to compress true lumen at or above origin and covers origin. During angiography of true lumen, aorta fills minimally or not at all, but branch arteries fill and appear to arise out of nowhere.

 


View larger version (139K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 5B. 45-year-old man (patient 11) with acute Stanford type B dissection. Angiogram obtained after stent-graft deployment shows normal blood flow in visceral arteries.

 

In both patients treated for penetrating ulcer, we observed progression of disease. Patient 5 was readmitted 2 months after primary therapy for acute intramural hemorrhage in the aortic wall proximal and distal to the stent-graft. The patient presented with severe chest pain and hemoptysis. Secondary repair was successfully performed by insertion of two additional stent-grafts. In patient 10, the 6-month follow-up revealed formation of aneurysms proximal and distal to the stent-graft (Fig. 6A,6B). However, no further therapy was performed because the patient was in poor physical condition.



View larger version (85K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 6A. 72-year-old man (patient 10) with penetrating ulcer of thoracic aorta. Posterior oblique volume-rendering reconstruction obtained after stent-graft deployment shows normal diameter of thoracic aorta proximal and distal to stent-graft.

 


View larger version (90K):
[in this window]
[in a new window]
[as a PowerPoint slide]
 
Fig. 6B. 72-year-old man (patient 10) with penetrating ulcer of thoracic aorta. Posterior oblique volume-rendering reconstruction obtained 6 months after intervention shows formation of aneurysms (arrows) proximal and distal to stent-graft. Dilatation of proximal and distal ends of stent-graft caused by pressure of aneurysms is evident.

 


Discussion
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
Emergency surgery for acute thoracic aortic disease is associated with substantial morbidity and with perioperative mortality rates between 25% and 50% [4, 5, 9], mainly owing to hemorrhage, heart or renal failure, or spinal cord injury. The decision for surgical repair of acute thoracic aortic disease becomes increasingly complex when patients have serious coexisting illnesses. All patients included in this feasibility study were at high surgical risk because of coronary disease, severe chronic obstructive pulmonary disease, or multiple trauma. Endoluminal repair offers several major advantages. Thoracotomy is avoided in the critically ill patient. The perioperative mortality rate in emergency endovascular repair of thoracic aortic aneurysms reported in the literature is 16-18% [9, 12]. In our series, the hospital mortality rate was 6.7%, which is considerably lower. However, these figures must be interpreted with caution because of the heterogeneous spectrum of aortic lesions and the small number of patients included in our study compared with surgical series conducted by other groups.

Another advantage of the stent-graft procedure over conventional surgery is the absence of aortic clamping. Moreover, the aortic leak can be sealed rapidly. Thus, stent-grafting techniques hold tremendous promise for the high-risk patient, but several limitations should be discussed. One key issue is proper device fixation. Aneurysms, dissections, and traumatic thoracic aortic injuries frequently originate just beyond the left subclavian artery where the proximal anchoring length is insufficient to provide safe support of the stent-graft in a healthy segment of the aortic wall. In our series, we had to overcome this problem in 11 patients. To provide secure proximal fixation of the graft, we placed its uncovered (n = 4) or covered (n = 7) proximal portion across the origin of the left subclavian artery. None of the patients developed signs of upper extremity ischemia or neurologic complications. In all patients in whom the left subclavian artery was crossed with the covered portion of the stent-graft, systolic and diastolic blood pressures in the left upper extremity decreased significantly. However, in all patients, postoperative angiography and duplex scanning during follow-up showed adequate collateral retrograde blood flow via the left vertebral artery. Therefore, stenoses that would interfere with collateralization in the carotid or vertebral arteries must be excluded before graft placement. In patient 9, who had earlier undergone mammary-to-coronary artery grafting, we performed subclavian carotid artery transposition to ensure blood supply to the heart. However, contrary to other groups [26, 27], we do not perform this procedure routinely because, in our experience, crossing of the left subclavian artery with the covered or uncovered portion of the stent-graft is well tolerated. Hausegger et al. [28] reported similar experiences.

Endoleaks are a common complication of endovascular repair of aortic disease and represent one of the major causes of failure [29, 30]. The percentage of endoleaks reported in the literature ranges from 0% to 44% [30]. In our series, primary endoleaks type I were observed in three patients (17%), including one distal and two proximal attachment zone endoleaks. In the two patients with proximal perigraft leaks, it was impossible to adapt the Talent graft to the curved aortic contour, because it was not flexible enough to apply to the curve of the distal arch. Several authors have emphasized that endoleaks type I observed after endovascular aneurysm repair should be treated aggressively because of the high risk for aneurysm rupture [24, 30, 31]. In patient 9, who was treated for a ruptured thoracic aortic aneurysm, primary hemodynamic stabilization was achieved despite endoleak type I. However, 20 hr after intervention persistent perfusion of the thrombus resulted in an aortobronchial fistula associated with a hemorrhage from the endotracheal tube, which led to prolonged shock and pulmonary failure. Despite therapy with catecholamines, the patient's blood pressure could not be stabilized; therefore, secondary interventional therapy was not possible. Unfortunately the patient died. In patient 14, secondary endoluminal repair was possible by insertion of an additional, more flexible stent-graft (Excluder) (Fig. 2A,2B).

Stent-graft migration and alterations in the shape and structure of the grafts are recognized complications of endovascular stent-grafting for abdominal aortic aneurysms [30, 32]. Therefore, at follow-up, we routinely obtain an additional unenhanced helical CT scan before obtaining the enhanced CT scan. The volume of interest is limited to the stent. Three-dimensional volume-rendering reconstructions of the stent-graft are performed and compared with each other in all planes. Because the struts can be delineated clearly, the 3D reconstructions allow exact evaluation of time-related changes in shape, position, and structure of the stent-grafts, The stent-graft can be isolated by segmentation and displayed and studied in all planes, whereas with conventional radiographs, exact diagnosis of changes in the structure of the graft may be difficult because conventional radiographs allow only two-dimensional images of the graft, and superimposing structures such as bones might obscure the struts. Moreover, in obese patients, delineation of the graft might be poor. Many changes may be recognized in conventional two-dimensional axial images; however, volume-rendering reconstructions provide additional 3D information regarding time-related changes of the graft. The results are important for both clinical application and research. We believe that the use of the unenhanced stent protocol has substantial advantages over conventional radiography or conventional axial CT.

In patient 3, who had received two grafts, the follow-up scans revealed alterations in the position of the distal device, resulting in disconnection of the two grafts in the overlapping area. This area seems to be particularly unstable, because we observed instability in this area in two more patients treated electively for atherosclerotic aneurysms. Therefore, it seems advisable to increase the overlapping area or to use only one graft that is long enough to cover the total length of the abnormality. However, stent-grafts are not always available in optimal lengths, especially in emergency procedures, in which standard grafts from the emergency kit have to be used. In elective procedures, individually designed and custom-fabricated grafts are used to meet the specifications derived from the preoperative imaging studies. These grafts should be fabricated well in advance of the procedure. Because in emergency cases even a delay of 30 hr is unacceptable and diminishes the usefulness of endovascular treatment, we store an emergency kit containing Talent stent-grafts of various sizes (130 mm in length and 26, 28, 38, 42, 44, and 46 mm in diameter). We keep two of each size. Talent grafts are available in large diameters (<=46 mm), and their FreeFlo design permits crossing the ostium of the left subclavian artery or the left carotid artery with the proximal uncovered portion of the stent-graft. Thus, the proximal anchoring site can be extended into a normal aortic segment if necessary. However, because of its semirigid design, the device is not flexible enough to apply to the curve of the distal arch or the proximal descending aorta in all cases. This feature may cause perigraft leaks, as observed in our study. Moreover, the covered portion of the grafts currently available has a maximal length of only 120 mm, which is not sufficient to cover the total length of large aortic segments in patients with diffuse aortic abnormalities. In these patients, two or more grafts are needed; this requirement causes additional costs and carries the risk for instability and graft migration in the overlapping area, as described previously. To improve emergency treatment in the future, we also store Excluder stent-grafts of various sizes. (100, 150, and 200 mm in length and 26, 28, 37, and 40 mm in diameter). We also keep two of each size. Excluder stent-grafts show a better longitudinal flexibility and are available with covered portions of 190 mm in length. However, maximal available graft diameter is only less than or equal to 40 mm. Therefore, we recommend the use of the Talent stent-graft (FreeFlo design) in patients with a proximal aortic neck greater than or equal to 36 mm or a short landing zone or both, whereas in patients with a proximal aortic neck less than or equal to 36 mm or a tortuous aortic arch or both, we recommend the use of the Excluder stent-graft. The Vanguard device is no longer used. It was withdrawn from the market because of frequent complications such as migration and suture breakage. In our series, we used the Vanguard device to treat traumatic rupture of the thoracic aorta in patients 1, 4, and 8 because we had no appropriate, small-sized Talent or Excluder stent-graft on hand. We have not observed any complications in these patients. Maintaining an in-hospital stock of various stent-grafts is expensive, but it is vital for the success of emergency stent-grafting.

Patients with a penetrating ulcer may have an even poorer prognosis than those with classic dissection type A or B. Coady et al. [33] described a higher risk for aortic rupture in penetrating ulcer (40%) than in type A (7%) or type B (3.6%) aortic dissection (p = 0.0001). Cooke et al. [34] recommended immediate repair of penetrating ulcers in symptomatic patients. Successful endoluminal repair of penetrating ulcers has been described by other groups [11, 35]. In our series, we observed progression of the disease in both patients treated for penetrating aortic ulcers, although primary repair was technically and clinically successful. Patient 5 underwent secondary repair for propagation of intramural hematoma proximal and distal to the stent-graft. Therapy was possible by insertion of an additional stent-graft. In patient 10, follow-up CT showed the formation of aneurysms proximal and distal to the stent-graft. This complication may indicate that stent-grafts cause changes in the wall stress in the aortic segments immediately adjacent to the graft. These changes may result in morphologic changes of the aorta, especially in diseased vessels. However, considering the high mortality rates in untreated patients, we will continue to perform endovascular therapy in patients at high surgical risk with penetrating ulcers and life-threatening symptoms. Reports on successful endoluminal therapy of penetrating ulcers support our view [11, 35].

In conclusion, in our limited experience, emergency repair of acute descending aortic disease by means of endovascular stent-graft placement can be successfully accomplished by an interdisciplinary team approach of radiologists and vascular surgeons. Given the high mortality and morbidity rates in emergency surgical treatment of acute aortic disease, it may represent an adequate and safe alternative to open-chest repair, especially in patients at high surgical risk. An emergency kit containing several stent-grafts of various diameters and lengths must be on hand, and close follow-up with CT is essential.

However, continued improvement of stent-graft design and long-term follow-up in large patient populations are mandatory before we would recommend this alternative method for wider use. At present, indications should be restricted to patients contraindicated for standard operative treatment because of relevant comorbidity.


References
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 

  1. Lindsay J, de Bakey ME, Beall AC. Diagnosis and treatment of diseases of the aorta. In: Schlant RC, Alexander RW, eds. The Heart. New York: McGraw Hill, 1994:2163 -2180
  2. de Bakey ME, McCollum CH, Graham JM. Surgical treatment of aneurysms of the descending thoracic aorta: long-term results in 500 patients. J Cardiovasc Surg 1978;19:571 -576[Medline]
  3. Mastroroberto P, Chello M. Emergency thoracoab-dominal aortic aneurysm repair: clinical outcome. J Thorac Cardiovasc Surg 1999;118:477 -481[Abstract/Free Full Text]
  4. Moreno-Cabral CE, Miller DC, Mitchell RS, et al. Degenerative and atherosclerotic aneurysms of the thoracic aorta: determinants of early and late surgical outcome. J Thorac Cardiovasc Surg 1984;88:1020 -1032[Abstract]
  5. Crawford ES, Hess KR, Cohen ES, Coselli JS, Safi HJ. Ruptured aneurysm of the descending thoracic and thoracoabdominal aorta: analysis according to size and treatment. Ann Surg 1991;213:417 -425[Medline]
  6. Pressler V, McNamara JJ. Thoracic aortic aneurysm: natural history and treatment. J Thorac Cardiovasc Surg 1980;79:489 -498[Medline]
  7. Dake MD, Miller DC, Semba CP, Mitchell RS, Walker PJ, Liddell RP. Transluminal placement of endovascular stent-grafts for the treatment of descending thoracic aortic aneurysms. N Engl J Med 1994;331:1729 -1734[Abstract/Free Full Text]
  8. Czermak BV, Waldenberger P, Fraedrich G, et al. Treatment of Stanford type B aortic dissection with stent-grafts: preliminary results. Radiology 2000;217:544 -550[Abstract/Free Full Text]
  9. Semba CP, Kato N, Kee ST, et al. Acute rupture of the descending thoracic aorta: repair with use of endovascular stent-grafts. J Vasc Interv Radiol 1997;8:337 -342[Medline]
  10. Nienaber CA, Fattori R, Lund G, et al. Nonsurgical reconstruction of thoracic aortic dissection by stent-graft placement. N Engl J Med 1999;340:1539 -1545[Abstract/Free Full Text]
  11. Murgo S, Dussaussois L, Golzarian J, et al. Penetrating atherosclerotic ulcer of the descending thoracic aorta: treatment by endovascular stent-graft. Cardiovasc Interv Radiol 1998;21:454 -458[Medline]
  12. Dake MD, Kato N, Mitchell RS, et al. Endovascular stent-graft placement for the treatment of acute aortic dissection. N Engl J Med 1999;340:1546 -1552[Abstract/Free Full Text]
  13. Kato N, Dake MD, Miller DC, et al. Traumatic thoracic aortic aneurysm: treatment with endovascular stent-grafts. Radiology 1997;205:657 -662[Abstract/Free Full Text]
  14. Schneider AJ. Assessment of risk factors and surgical outcome. Surg Clin North Am 1983;63:1113 -1126[Medline]
  15. Williams DM, Lee DY, Hamilton BH, et al. The dissected aorta. III. Anatomy and radiologic diagnosis of branch-vessel compromise. Radiology 1997;203:37 -44[Abstract/Free Full Text]
  16. Williams DM, Lee DY, Hamilton BH, et al. The dissected aorta: percutaneous treatment of ischemic complications—principles and results. J Vasc Interv Radiol 1997;8:605 -625[Medline]
  17. Dorffner R, Thurnher S, Polterauer P, Kretschmer G, Lammer J. Treatment of abdominal aortic aneurysms with transfemoral placement of stent-grafts: complications and secondary radiologic intervention. Radiology 1997;204:79 -86[Abstract/Free Full Text]
  18. Mitchell RS, Dake MD, Sembra CP, et al. Endovascular stent-graft repair of thoracic aortic aneurysms. J Thorac Cardiovasc Surg 1996;111:1054 -1062[Abstract/Free Full Text]
  19. Dake MD. Endovascular stent-graft management of thoracic aortic diseases. Eur J Radiol 2001;39:42 -49[Medline]
  20. Hallett JW Jr, Brewster DC, Rasmussen TE. Noninvasive vascular testing. In: Hallett JW Jr, Brewster DC, Rasmussen TE, eds. Handbook of patient care in vascular diseases. Philadelphia: Lippincott Williams & Wilkins, 2001:31 -35
  21. White GH, Yu W, May J, Chaufour X, Stephen MS. Endoleak as a complication of endoluminal grafting of abdominal aortic aneurysms: classification, incidence, diagnosis, and management. J Endovasc Surg 1997;4:152 -168[Medline]
  22. White GH, May J, Waugh RC, Chaufour X, Yu W. Type III and type IV endoleak: toward a complete definition of blood flow in the sac after endoluminal AAA repair. J Endovasc Surg 1998;5:305 -309[Medline]
  23. White GH, Yu W, May J. Endoleak: a proposed new terminology to describe incomplete aneurysm exclusion by an endoluminal graft. J Endovasc Surg 1996;3:124 -125
  24. Czermak BV, Fraedrich G, Schocke MF, et al. Serial CT volume measurements after endovascular aortic aneurysm repair. J Endovasc Ther 2001;8:380 -389[Medline]
  25. Breiman RS, Beck JW, Korobkin M, et al. Volume determinations using computed tomography. AJR 1982;138:329 -333[Abstract/Free Full Text]
  26. Dake MD, Miller DC, Mitchell RS, Semba CP, Moore KA, Sakai T. The "first generation" of endovascular stent-grafts for patietns with aneurysms of the descending thoracic aorta. J Thorac Cardiovasc Surg 1998;11:689 -703
  27. Ehrlich M, Grabenwoeger M, Cartes-Zumelzu F, et al. Endovascular stent-graft repair for aneurysms on the descending thoracic aorta. Ann Thorac Surg 1998;66:19 -24[Abstract/Free Full Text]
  28. Hausegger KA, Oberwalder P, Tiesenhausen K, et al. Intentional left subclavian artery occlusion by thoracic aortic stent-grafts without surgical transposition. J Endovasc Ther 2001;8:472 -476[Medline]
  29. Fann JI, Miller DC. Endovascular treatment of descending thoracic aortic aneurysms and dissections. Surg Clin North Am 1999;79:551 -574[Medline]
  30. D'Ayala M, Hollier LH, Marin ML. Endovascular grafting for abdominal aortic aneurysms. Surg Clin North Am 1998;78:845 -862[Medline]
  31. Harris PL, Vallabhaneni SR, Desgranges P, Becquemin JP, Van Marrewijk C, Laheij RJ. Incidence and risk factors of late rupture, conversion, and death after endovascular repair of infrarenal aortic aneurysms: the EUROSTAR experience. J Vasc Surg 2000;32:739 -749[Medline]
  32. Resch T, Ivancev K, Brunkwall J, Nyman U, Malina M, Lindblad B. Distal migration of stent-grafts after endovascular repair of abdominal aortic aneurysms. J Vasc Interv Radiol 1999;10:257 -264[Medline]
  33. Coady MA, Rizzo JA, Hammond GL, Pierce JG, Kopf GS, Elefteriades JA. Penetrating ulcer of the thoracic aorta: what is it? How do we recognize it? How do we manage it? J Vasc Surg 1998;27:1006 -1015[Medline]
  34. Cooke JP, Kazmier FJ, Orszulak TA. The penetrating aortic ulcer: pathologic manifestations, diagnosis, and management. Mayo Clin Proc 1988;63:718 -725[Medline]
  35. Brittenden J, McBride K, McInnes G, Gillespie IN, Bradbury AW. The use of endovascular stents in the treatment of penetrating ulcers of the thoracic aorta. J Vasc Surg 1999;30:946 -949[Medline]

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
Circ Cardiovasc InterventHome page
D. Y. Sze, M. A.A.J. van den Bosch, M. D. Dake, D. C. Miller, L. V. Hofmann, R. Varghese, S. C. Malaisrie, P. J.A. van der Starre, J. Rosenberg, and R. S. Mitchell
Factors Portending Endoleak Formation After Thoracic Aortic Stent-Graft Repair of Complicated Aortic Dissection
Circ Cardiovasc Intervent, April 1, 2009; 2(2): 105 - 112.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
Z. H. Dong, W. G. Fu, Y. Q. Wang, D. Q. Guo, X. Xu, Y. Ji, B. Chen, J. H. Jiang, J. Yang, Z. Y. Shi, et al.
Retrograde Type A Aortic Dissection After Endovascular Stent Graft Placement for Treatment of Type B Dissection
Circulation, February 10, 2009; 119(5): 735 - 741.
[Abstract] [Full Text] [PDF]


Home page
Card Surg AdultHome page
T. G. Gleason and J. E. Bavaria
Trauma to the Great Vessels
Card. Surg. Adult, January 1, 2008; 3(2008): 1333 - 1354.
[Full Text]


Home page
J. Thorac. Cardiovasc. Surg.Home page
B. Marcheix, C. Dambrin, J.-P. Bolduc, C. Arnaud, C. Cron, L. Hollington, A. Mugniot, P. Soula, M. Bennaceur, V. Chabbert, et al.
Midterm results of endovascular treatment of atherosclerotic aneurysms of the descending thoracic aorta.
J. Thorac. Cardiovasc. Surg., November 1, 2006; 132(5): 1030 - 1036.
[Abstract] [Full Text] [PDF]


Home page
Arch SurgHome page
D. R. Lebl, R. A. Dicker, D. A. Spain, and S. I. Brundage
Dramatic shift in the primary management of traumatic thoracic aortic rupture.
Arch Surg, February 1, 2006; 141(2): 177 - 180.
[Abstract] [Full Text] [PDF]


Home page
RadioGraphicsHome page
G. Garzon, M. Fernandez-Velilla, M. Marti, I. Acitores, F. Ybanez, and L. Riera
Endovascular Stent-Graft Treatment of Thoracic Aortic Disease
RadioGraphics, October 1, 2005; 25(suppl_1): S229 - S244.
[Abstract] [Full Text] [PDF]


Home page
RadioGraphicsHome page
E. Therasse, G. Soulez, M.-F. Giroux, P. Perreault, L. Bouchard, J.-F. Blair, N. Beaudoin, A. Benko, and V. L. Oliva
Stent-Graft Placement for the Treatment of Thoracic Aortic Diseases
RadioGraphics, January 1, 2005; 25(1): 157 - 173.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
J. Timperley and A. P. Banning
Prognosis of Aortic Intramural Hematoma With and Without Penetrating Atherosclerotic Ulcer: A Clinical and Radiological Analysis
Circulation, March 11, 2003; 107 (9): e63 - e63.
[Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Czermak, B. V.
Right arrow Articles by Jaschke, W. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Czermak, B. V.
Right arrow Articles by Jaschke, W. R.
Social Bookmarking
 Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Hotlight (NEW!)
Right arrow
What's Hotlight?


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS