- Email: [email protected]
Repair of Chronic Type B Dissection With Aortic Arch Involvement Using a Stented Elephant Trunk Procedure
LiZhong Sun, MD,* Xin Zhao, MD,* Qian Chang, MD, JunMing Zhu, MD, YongMin Liu, MD, CunTao Yu, MD, Bin Lv, MD, Jun Zheng, MD, and RuiDong Qi, MD Department of Cardiovascular Surgery and Department of Radiology, Cardiovascular Institute and Fuwai Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing; and Department of Cardiovascular Surgery, Tianjin Cardiovascular Institute and Tianjin Chest Hospital, Tianjin, China
Background. A conventional single-stage procedure, staged procedures, or debranching of the supraaortic vessels, followed by immediate transfemoral stenting of the aortic arch, have been introduced to treat chronic type B dissection with aortic arch involvement. The best method for surgical repair of chronic type B dissection with aortic arch involvement alone or concomitant with proximal aortic lesions is not known. Methods. Between October 2003 and December 2008, 19 patients underwent total arch replacement combined with stented elephant trunk implantation under hypothermic cardiopulmonary bypass and selective cerebral perfusion through a median sternotomy. Thirteen patients had proximal aortic lesions. Postoperative computed tomography was used to evaluate thrombosis and absorption of the false lumen. Results. Concomitant proximal aortic lesions were repaired in all patients. Thirty-day mortality was 5.26%
(1/19). There was one late death at a mean follow-up of 36 ⴞ 12 months. There was no spinal cord injury or visceral malperfusion. One patient with Marfan syndrome with chronic dissection underwent thoracoabdominal aortic replacement 6 months later. Obliteration of the false lumen around the stented elephant trunk was observed in 16 patients (94.1%, 16/17) during follow-up. Conclusions. This technique is safe, effective, and economical. Replacement of aortic arch dissection and thrombosis of the dissected descending aorta was achieved simultaneously. Concomitant proximal aortic lesions were repaired. Favorable surgical outcomes and postoperative results using this technique were obtained in patients with chronic type B dissection with aortic arch involvement alone or concomitant with proximal aortic lesions. (Ann Thorac Surg 2010;90:95–100) © 2010 by The Society of Thoracic Surgeons
P
the supraaortic vessels, followed by immediate transfemoral stenting of the aortic arch for this lesion, is not known. We reviewed our experience of surgical treatment of chronic type B dissection with AAI using total arch replacement combined with stented elephant trunk implantation.
atients with uncomplicated type B dissection are usually treated medically [1, 2], and surgical or endovascular therapy is recommended for complicated type B dissection [2, 3]. Management of type B dissection with aortic arch involvement (AAI) is not specifically addressed in the current Stanford classification. The Stanford group recommended surgical intervention in patients with type B dissection and AAI [4]. Optimal surgical management of type B dissection with AAI alone or concomitant with proximal aortic lesions is controversial. The repair of aortic arch dissection or simultaneous proximal aortic lesions and descending dissection through a median sternotomy or lateral thoracotomy using a conventional single-stage procedure is troublesome. Rupture of the remaining aneurysmal aorta during the interval between the first and second stage of the procedure has been observed, leading to death. Long-term outcome of debranching of
Accepted for publication March 11, 2010. *LiZhong Sun and Xin Zhao contributed equally to this work. Address correspondence to Dr LZ Sun, Beijing Aortic Disease Center, Beijing Anzhen Hospital, Capital Medical University, 2 Anzhen Rd, Beijing 100029, China; e-mail: [email protected].
© 2010 by The Society of Thoracic Surgeons Published by Elsevier Inc
Patients and Methods The procedure described was approved by the Institutional Review Board of the Chinese Academy of Medical Science and Peking Union Medical College in Beijing, China. Informed consent was obtained from each patient.
Patient Data From October 2003 to December 2008, 19 patients (15 men and 4 women) with chronic type B dissection and AAI (Fig 1) underwent total arch replacement combined with stented elephant trunk implantation under hypothermic cardiopulmonary bypass (CPB) and selective cerebral perfusion through a median sternotomy in Fuwai Hospital (Beijing, China). Patients were a mean age of 45 ⫾ 9 years (range, 22 to 59 years). A history of hypertension 0003-4975/$36.00 doi:10.1016/j.athoracsur.2010.03.048
ADULT CARDIAC
Repair of Chronic Type B Dissection With Aortic Arch Involvement Using a Stented Elephant Trunk Procedure
96
SUN ET AL MANAGEMENT FOR TYPE B DISSECTION
Ann Thorac Surg 2010;90:95–100
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Fig 1. Preoperative computed tomography images of a patient with chronic type B dissection with aortic arch involvement show (A, B, and C, black symbol) the left common carotid artery was involved by aortic dissection and was significantly dilated. (B, C, and D) The aortic arch was involved by aortic dissection. (B, C, D, E, and F) The false lumen was remarkably expanded, and (E and F, black symbol) the ascending aorta was normal.
towards the origin of the innominate artery in 7 patients. Presentation of aortic dissection with the intimal tear in the descending aorta with retrograde extension toward the aortic arch was observed in 16 patients. The aortic dissection with the intimal tear in the aortic arch ex-
was observed in 15 patients and Marfan syndrome in 2. Thirteen patients had proximal aortic lesions (Table 1). Aortic dissection extending retrogradely towards the origin of the left common carotid artery was observed in 12 patients, and aortic dissection extending retrogradely
Table 1. Clinical Profiles of Patients With Chronic Type B Dissection With Aortic Arch Involvement Patient
Interval (mon)
Concomitant Procedures
Age
Symptoms and Findings
Location
1
56
PDA
1
AVR ⫹ AAR
Alive
2
40
PDA
2
Septal myectomy
Alive
3
22
PDA
4
Bentall ⫹ AAR
Alive
4 5 6 7 8
42 43 48 49 48
Hypertension, ascending aorta and AA aneurysm, AI, AS Hypertension, hypertrophic cardiomyopathy Marfan syndrome, ascending aorta and AA aneurysm, AI Hypertension
AVR ⫹ AAR
Alive Alive Alive Alive Alive
9
46
24
AAR
Alive
10
30
Unknown
AAR
Alive
11
52
12
37
13 14
33 56
15 16
43 42
17
52
18
59
19
43
Hypertension Hypertension Hypertension, pulmonary infection, ascending aortic aneurysm, AI Hypertension, ascending aortic aneurysm Hypertension, ascending aortic aneurysm Hypertension, ascending aorta and AA aneurysm Marfan syndrome, aortic root, ascending aorta and AA aneurysm Hypertension Hypertension, coronary artery disease, ascending aortic aneurysm, diabetes Ascending aortic aneurysm Hypertension, ascending aortic aneurysm Hypertension, ascending aortic aneurysm Hypertension, ascending aortic aneurysm Hypertension
PDA PDA AA PDA PDA AA PDA
60 1 2 108 Unknown
Result
PDA
2
AAR
Alive
PDA
1
Bentall ⫹ AAR
Alive
PDA PDA
4 1
AAR ⫹ CABG
Alive Follow-up death
PDA PDA
1 1
AAR AAR
In-hospital death Alive
AA
1
AAR
Alive
PDA
3
AAR
Alive
PDA
1
Alive
AA ⫽ aortic arch; AAR ⫽ ascending aortic replacement; AI ⫽ aortic incompetence; AS ⫽ aortic stenosis; AVR ⫽ aortic valve replacement; CABG ⫽ coronary artery bypass grafting; Interval ⫽ interval between the onset of aortic dissection and the operation; Location ⫽ location of the original intimal tear; PDA ⫽ proximal descending aorta.
SUN ET AL MANAGEMENT FOR TYPE B DISSECTION
Table 2. Visceral Arteries: From the True Lumen or the False Lumen? Artery Celiac artery Superior mesenteric artery Right renal artery Left renal artery
False
True
Both
7 1 1 6
10 14 16 8
1 3 1 4
tended antegrade to the descending aorta in 3 patients, the dissection extended into the distal descending thoracic aorta in 1 patient, and into the abdominal aorta in 18. The mean interval between the onset of aortic dissection and repair was 18 ⫾ 29 months (range, 1 to 108 months). The visceral arteries and location of entry and reentry were carefully assessed in 18 of 19 patients (Table 2). Appropriate sizing of the stented elephant trunk was close to the diameter of the proximal descending aorta of healthy individuals matched for age, sex, and height. The diameter of the stent graft was larger than that of the true lumen and was smaller than that of the entire aorta as determined by preoperative computed tomography (CT) and intraoperative judgment. Postoperative CT with contrast enhancement was done routinely to evaluate thrombosis and absorption of the false lumen in all patients who survived to hospital discharge, 3 or 6 months postoperatively, and once yearly after hospital discharge.
Surgical Technique The technique for total arch replacement combined with stented elephant trunk implantation has been described in detail by our research group [5, 6]. An intraoperative stent graft (MicroPort Medical Co Ltd, Shanghai, China) and a Meadox Hemashield Platinum 4 Branch Graft (Boston Scientific Inc, Boston, MA) were used in this technique. The stented graft was only 10-cm long. The proximal and distal ends of the surgical stent graft had 1 cm of extra vascular graft to be used for sewing. In brief, patients underwent median sternotomy and total CPB; cannulation of the right axillary artery was used for CPB and selective cerebral perfusion (SCP). After CPB was established, cooling was initiated. The ascending aorta was clamped, and cardiac arrest was initiated with cold cardioplegic solution. Aortic root procedures were done (if necessary). Circulatory arrest was established when the nasopharyngeal temperature reached 18° to 22°C. SCP was started through the right axillary artery, and the brain was perfused at approximately 5 to 10 mL/kg/min. The transverse arch was opened. The distal aorta was transected circumferentially close to the proximal margin of the origin of the left subclavian artery. The stented elephant trunk was implanted into the descending aorta. The anastomosis between the 4-branched prosthetic graft and the descending aorta was accomplished using the open aortic technique. The stented elephant trunk incor-
97
porating the distal aorta was firmly attached to the distal end of the 4-branched prosthetic graft using the suture line. Antegrade distal aortic perfusion was commenced using the branch graft. Patients were rewarmed after the left common carotid artery was reconstructed. The innominate artery and left subclavian artery were anastomosed end-to-end to the corresponding limbs of the 4-branched prosthetic graft. The proximal anastomosis was then accomplished.
Results Surgical Data All patients with type B dissection underwent total replacement of the aortic arch combined with stented elephant trunk implantation under hypothermic CPB with SCP. The mean CPB time was 173 ⫾ 27 minutes (range, 125 to 227 minutes), the mean aortic cross-clamp time was 87 ⫾ 19 minutes (range, 50 to 118 minutes), and the mean SCP time was 23 ⫾ 7 minutes (range, 15 to 38 minutes). Concomitant proximal aortic lesions were repaired in all patients (Table 1).
Morbidity and Mortality Thirty-day mortality was 5.26% (1/19). The patient suffered from respiratory failure due to severe pneumonia. Unfortunately, he died of multiple organ failure. Transient neurologic dysfunction was observed in 1 patient. No injury to the spinal cord or visceral malperfusion was observed during the procedure or during follow-up. There was one late death due to acute myocardial infarction during a mean follow-up of 36 ⫾ 12 months (range, 18 to 71 months). One patient with Marfan syndrome with chronic dissection underwent thoracoabdominal aortic replacement 6 months postoperatively.
Imaging Seventeen of 18 patients underwent CT during followup. Obliteration of the false lumen around the stented elephant trunk was observed in 16 patients (94.1%, 16/17). Complete thrombus formation at the diaphragmatic level occurred in 41.2% (7/17) patients during follow-up (Fig 2). The preoperative false lumen of the descending aorta was 3.32 ⫾ 0.80 cm. The diameter of the descending aorta was 3.27 ⫾ 0.67 cm preoperatively vs 4.23 ⫾ 0.78 cm postoperatively. The descending aorta returned to normal in 5 of 17 patients (29.4%) during follow-up after remodeling of the aortic wall. Obvious enlargement of the abdominal aorta was not observed at the level of the superior mesenteric artery compared with preoperative imaging.
Comment Optimal surgical management of type B dissection with AAI alone or concomitant with proximal aortic lesions is controversial. A conventional single-stage procedure has been used for type B dissection with AAI alone or concomitant with proximal aortic lesions. Repairing aor-
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Ann Thorac Surg 2010;90:95–100
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SUN ET AL MANAGEMENT FOR TYPE B DISSECTION
Ann Thorac Surg 2010;90:95–100
ADULT CARDIAC Fig 2. Computed tomography images of a patient with chronic type B dissection with aortic arch involvement (A and E) preoperatively, (B and F) 2 weeks, (C and G) 4 months, and (D and H) 13 months after the operation. (A and E) The true lumen was compressed by the false lumen; (B and F) the false lumen was partially filled with thrombus postoperatively; (C and G) the false lumen was obliterated with thrombus; (D and H) the true lumen was resumed completely, and the descending aorta returned to normal during follow-up.
tic arch dissection or simultaneous proximal aortic lesions and descending dissection through a median sternotomy or lateral thoracotomy is troublesome. Protecting the myocardium and cerebrum through a lateral thoracotomy is also difficult. Bilateral anterior thoracotomy [7] or a median sternotomy combined with lateral thoracotomy [8] may be an option. Despite acceptable early results, these procedures may be too invasive [7, 8]. A staged procedure may be used for type B dissection with AAI. To facilitate subsequent operations after a lateral thoracotomy, elephant trunk implantation has been used as a staged procedure for treatment of this lesion, but complications such as kinking and obstruction of the graft, embolization, and paraplegia have been observed [9]. Deaths due to rupture of the remaining aneurysmal aorta during the interval between the first and second stage of the procedure were recorded. Selecting an appropriated interval between the two procedures was problematic. Some patients failed to return for the second stage of the operation [10]. The technique is also associated with high hospital expenses, and the secondstage procedure is associated with high morbidity and mortality. Debranching of the supraaortic vessels, followed by immediate transfemoral stenting of the aortic arch, has also been recommended for type B dissection with AAI [11], but several factors have to be considered. First, attachment of the endograft to the aortic wall is achieved by the radial force of the stent graft. This increases injury to the aortic wall, particularly in patients with Marfan syndrome. Endoleaks due to the dilatation of fixation zones for endografts can occur. Second, the maneuver is potentially difficult in the aortic arch because of its curvature, movement, and high flow. A higher prevalence of cerebrovascular accidents by embolization of atherosclerotic debris or detachment of soft plaques can occur due to brisk manipulation of the
stent graft introducer in the aortic arch. The mortality rate associated with this hybrid procedure was high due to cerebrovascular events and the greater frequency of type I endoleaks [12–14]. Third, the long-time durability of an end-to-side anastomosis of a graft to the ascending aorta is uncertain. An end-to-side anastomosis has poor hemodynamics compared with an end-to-end anastomosis. Fourth, some patients were unsuitable for this procedure because of small or diseased access iliac arteries. Most importantly, lesions located in the aortic root and the ascending aorta could not been repaired concomitantly. The entire diseased aortic arch is preserved with debranching of the supraaortic vessels. Meanwhile, severe complications were reported during supraaortic debranching and endovascular stenting of the aortic arch and the descending aorta in patients with type B dissection [15]. So we thought this method should be limited to patients who cannot tolerate open operations. Management of type B dissection with AAI was not specifically addressed in the current Stanford classification. In our center, aortic dissection with the intimal tear in the descending aorta, with retrograde extension towards the aortic arch or with the intimal tear in the aortic arch extending antegrade to the descending aorta, was called Stanford type B aortic dissection with aortic arch involvement. To determine the indication and optimal surgical procedure, Stanford type B dissection was divided into subgroup C (complex type with AAI) and subgroup S (simple type without aortic-arch involvement) by Sun and colleagues. The stented elephant trunk has been developed to successfully treat acute [5, 6, 16, 17] and chronic [5, 18] type A dissection by our research group. To avoid development of a retrograde type A dissection, extensive dilatation of the thoracoabdominal aorta, or late recurrence of proximal aortic dissection, we introduced total arch replacement combined with a
stented elephant trunk to treat patients with type B dissection with AAI (subgroup C) alone or concomitant with proximal aortic lesions. Compared with the technique described above, total arch replacement combined with stented elephant trunk implantation for treatment of type B dissection with AAI (subgroup C) alone or concomitant with proximal aortic lesions had several advantages. The biggest advantage of this technique was that it had the characteristics of open surgical treatment and an interventional approach. Replacement of aortic arch dissection and thrombosis of the dissected descending aorta were achieved simultaneously through a median sternotomy. Concomitant proximal aortic lesions were repaired, and protecting the myocardium and cerebrum through a median sternotomy was easy. There were no severe cerebral complications in this group. Complications related to the endografting procedure (eg, cerebrovascular accident, endoleak) could be avoided due to fixation of the stented elephant trunk to the prosthetic graft using the suture line. Death associated with cerebrovascular accidents and endoleaks could also be avoided. The lesions from the heart to the aortic arch were completely removed with this technique. The diameter of the stented elephant trunk was close to the diameter of the proximal descending aorta of healthy individuals matched for age, sex, and height. The radial force exerted by the stented elephant trunk was relatively low, and injury to the aortic wall caused by the stented elephant trunk was small. The use of deep hypothermic circulatory arrest with SCP avoided injury to the aortic wall due to endografting under aortic pulsation. In addition, the patients tended to be younger in this group (mean age, 45 ⫾ 9 years) and would survive longer after a successful operation. So this more aggressive approach might be justified for this group. Accepted surgical outcomes were obtained in this group. Thirty-day mortality was 5.26%. However, surgical treatment of chronic aortic dissection using the stented elephant trunk procedure was controversial due to the visceral arteries and intercostal arteries originating from the false lumen. With respect to spinal cord injury, no paraplegia or paralysis was observed. In our opinion, ischemia in the chronic phase of chronic aortic dissection enhances spinal cord tolerance to subsequent surgical ischemia by collateral circulation in patients with intercostal arteries from the false lumen [18]. In addition, the speed of thrombosis of the false lumen was low in patients with chronic dissection due to the rigid chronic dissected membrane. Collateral circulation of the spinal cord also formed after implantation of the stented elephant trunk into the true lumen of the distal aorta. Also, no visceral ischemia was observed in this group. This may be because reentry must be near the origin of the visceral artery when the visceral artery originated from the false lumen. The reentry was sufficiently large to supply to the visceral artery. Otherwise, symptoms of visceral organ ischemia must occur in the acute phase if insufficient blood flow through the reentry was supplied
SUN ET AL MANAGEMENT FOR TYPE B DISSECTION
99
to visceral organs from the false lumen. Collateral arteries also have an important role in this situation [18]. With regard to cerebral injury, no stroke occurred in this study. This may be because SCP had an effective role in brain protection and because of our experience with surgical treatment for type A dissection [5, 6, 16 –18]. Acceptable postoperative results were also obtained. Thrombosis of the false lumen around the stented elephant trunk was observed in most patients. Thrombosis of the false lumen extended gradually to the diaphragmatic level along with extension of follow-up time. Only 1 patient with Marfan syndrome, who had chronic dissection, underwent late thoracoabdominal aortic replacement. The preoperative diameter of the descending aorta exceeded 60 mm in this patient, and the stent graft was used to facilitate staged aortic replacement. Weakness and fragility of the aortic wall also disturb thrombotic closure of the false lumen in the descending aorta in patients with Marfan syndrome. Thrombus formation in the false lumen reduced stress in the aortic wall, preventing subsequent growth of the distal aorta. This retrospective study had limitations. First, the number of patients may be too small to reach definitive conclusions. Second, the follow-up for patients with type B dissection and AAI was limited to a mean of 36 ⫾ 12 months. Longer follow-up is required to validate the effectiveness of this technique for chronic type B dissection with AAI. In conclusion, this technique is safe, effective, and economical. Replacement of aortic arch dissection and thrombosis of the dissected descending aorta was achieved simultaneously. Concomitant proximal aortic lesions were repaired. It enabled protection of the myocardium and cerebrum via a median sternotomy. Favorable surgical outcomes and postoperative results using this technique were obtained in patients with chronic type B dissection and AAI.
References 1. Daily PO, Trueblood HW, Stinson EB, Wuerflein RD, Shumway NE. Management of acute aortic dissections. Ann Thorac Surg 1970;10:237– 47. 2. Elefteriades JA, Lovoulos CJ, Coady MA, Tellides G, Kopf GS, Rizzo JA. Management of descending aortic dissection. Ann Thorac Surg 1999;67:2002–5; discussion 14 –9. 3. Crawford ES, Svensson LG, Coselli JS, Safi HJ, Hess KR. Aortic dissection and dissecting aortic aneurysms. Ann Surg 1988;208:254 –73. 4. Yun KL, Glower DD, Miller DC, et al. Aortic dissection resulting from tear of transverse arch: is concomitant arch repair warranted? J Thorac Cardiovasc Surg 1991;102:355– 68; discussion 68 –70. 5. Liu ZG, Sun LZ, Chang Q, et al. Should the “elephant trunk” be skeletonized? Total arch replacement combined with stented elephant trunk implantation for Stanford type A aortic dissection. J Thorac Cardiovasc Surg 2006;131:107–13. 6. Sun L, Qi R, Chang Q, et al. Surgery for Marfan patients with acute type a dissection using a stented elephant trunk procedure. Ann Thorac Surg 2008;86:1821–5. 7. Kouchoukos NT, Mauney MC, Masetti P, Castner CF. Single-stage repair of extensive thoracic aortic aneurysms: experience with the arch-first technique and bilateral anterior thoracotomy. J Thorac Cardiovasc Surg 2004;128:669 –76.
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8. Hu XP, Chang Q, Zhu JM, Yu CT, Liu ZG, Sun LZ. One-stage total or subtotal aortic replacement. Ann Thorac Surg 2006; 82:542– 6. 9. Crawford ES, Coselli JS, Svensson LG, Safi HJ, Hess KR. Diffuse aneurysmal disease (chronic aortic dissection, Marfan, and mega aorta syndromes) and multiple aneurysm. Treatment by subtotal and total aortic replacement emphasizing the elephant trunk operation. Ann Surg 1990; 211:521–37. 10. Safi HJ, Miller CC, 3rd, Estrera AL, et al. Staged repair of extensive aortic aneurysms: morbidity and mortality in the elephant trunk technique. Circulation 2001;104:2938 – 42. 11. Iannelli G, Monaco M, Di Tommaso L, Piscione F. Complicated acute type B aortic dissection involving the arch: treatment by simultaneous hybrid approach under local anesthesia. J Thorac Cardiovasc Surg 2008;135:1380 –2. 12. Melissano G, Bertoglio L, Civilini E, et al. Results of thoracic endovascular grafting in different aortic segments. J Endovasc Ther 2007;14:150 –7.
Ann Thorac Surg 2010;90:95–100
13. Melissano G, Civilini E, Bertoglio L, et al. Results of endografting of the aortic arch in different landing zones. Eur J Vasc Endovasc Surg 2007;33:561– 6. 14. Saleh HM, Inglese L. Combined surgical and endovascular treatment of aortic arch aneurysms. J Vasc Surg 2006;44:460–6. 15. Akhyari P, Kamiya H, Heye T, Lichtenberg A, Karck M. Aortic dissection type A after supra-aortic debranching and implantation of an endovascular stent-graft for type B dissection: A word of caution. J Thorac Cardiovasc Surg 2009;137:1290 –2. 16. Sun L, Qi R, Chang Q, et al. Surgery for acute type A dissection with the tear in the descending aorta using a stented elephant trunk procedure. Ann Thorac Surg 2009;87:1177–80. 17. Sun L, Qi R, Chang Q, et al. Surgery for acute type A dissection using total arch replacement combined with stented elephant trunk implantation: experience with 107 patients. J Thorac Cardiovasc Surg 2009;138:1358 – 62. 18. Sun L, Qi R, Chang Q, et al. Is total arch replacement combined with stented elephant trunk implantation justified for patients with chronic Stanford type A aortic dissection? J Thorac Cardiovasc Surg 2009;138:892– 6.
INVITED COMMENTARY The combination of aortic arch involvement with a chronic type B aortic dissection is a relatively common scenario whose treatment remains somewhat problematic. Management of the aortic arch or more proximal lesions may be difficult from a thoracotomy exposure, and treatment of the dilated proximal descending thoracic aorta by performing a sternotomy can also be challenging. Combined incisions (thoracosternotomy or bilateral anterior thoracotomy) are associated with increased morbidity. Arch debranching with stent grafting seems to require a similar arch exposure with compromised durability. The authors’ approach [1] seems to provide many advantages. Sternotomy incisions are reasonably well tolerated, more proximal lesions can be managed simultaneously, and the stented elephant trunk appears to stabilize downstream pathology in the majority of patients. One exception would be in Marfan or other syndromic patients, in which the stent grafts are known to function poorly. Implantation of a 10-cm long elephant trunk was not associated with paraplegia or malperfusion syndromes, and promoted false lumen thrombosis for the length of the stent graft in 16 of 17 patients, and thrombosis of the entire thoracic aortic false lumen in 7 of 17. This may then obviate the necessity for further surgical management of the chronic dissection in a substantial proportion of these problematic patients. The only difficulty with this approach is that it requires a stent graft with an extra centimeter of attached regular vascular graft, proximally and distally, to which a conventional hand-sewn anastomosis can be performed. No such graft is available in North America. We have ap-
© 2010 by The Society of Thoracic Surgeons Published by Elsevier Inc
proached these patients in a very similar manner, but have used a long elephant trunk instead of a stent graft. We then compress the elephant trunk within an endoluminal snare threaded into the arch through the true lumen from a femoral puncture, and we pull it distally into the true lumen of the descending thoracic aorta under direct vision. Then this can be easily sewn to a triple-branched arch graft in the conventional manner. Although an unstented elephant trunk may not be as effective in stabilizing the dissection septum and promoting false lumen thrombosis, this procedure has promoted false lumen thrombosis in the majority of cases, and it can be further expanded or lengthened with a transfemorally placed stent graft at a later date, if necessary. The authors [1] are to be congratulated for their combined approach in the management of a difficult patient population. Robert Scott Mitchell, MD Department of Cardiothoracic Surgery Stanford University Medical Center Falk CVRC 300 Pasteur Dr Stanford, CA 94305 e-mail: [email protected]
Reference 1. Sun LZ, Zhao X, Chang Q, et al. Repair of chronic type B dissection with aortic arch involvement using a stented elephant trunk procedure. Ann Thorac Surg 2010;90:95–100.
0003-4975/$36.00 doi:10.1016/j.athoracsur.2010.03.089
Background. A conventional single-stage procedure, staged procedures, or debranching of the supraaortic vessels, followed by immediate transfemoral stenting of the aortic arch, have been introduced to treat chronic type B dissection with aortic arch involvement. The best method for surgical repair of chronic type B dissection with aortic arch involvement alone or concomitant with proximal aortic lesions is not known. Methods. Between October 2003 and December 2008, 19 patients underwent total arch replacement combined with stented elephant trunk implantation under hypothermic cardiopulmonary bypass and selective cerebral perfusion through a median sternotomy. Thirteen patients had proximal aortic lesions. Postoperative computed tomography was used to evaluate thrombosis and absorption of the false lumen. Results. Concomitant proximal aortic lesions were repaired in all patients. Thirty-day mortality was 5.26%
(1/19). There was one late death at a mean follow-up of 36 ⴞ 12 months. There was no spinal cord injury or visceral malperfusion. One patient with Marfan syndrome with chronic dissection underwent thoracoabdominal aortic replacement 6 months later. Obliteration of the false lumen around the stented elephant trunk was observed in 16 patients (94.1%, 16/17) during follow-up. Conclusions. This technique is safe, effective, and economical. Replacement of aortic arch dissection and thrombosis of the dissected descending aorta was achieved simultaneously. Concomitant proximal aortic lesions were repaired. Favorable surgical outcomes and postoperative results using this technique were obtained in patients with chronic type B dissection with aortic arch involvement alone or concomitant with proximal aortic lesions. (Ann Thorac Surg 2010;90:95–100) © 2010 by The Society of Thoracic Surgeons
P
the supraaortic vessels, followed by immediate transfemoral stenting of the aortic arch for this lesion, is not known. We reviewed our experience of surgical treatment of chronic type B dissection with AAI using total arch replacement combined with stented elephant trunk implantation.
atients with uncomplicated type B dissection are usually treated medically [1, 2], and surgical or endovascular therapy is recommended for complicated type B dissection [2, 3]. Management of type B dissection with aortic arch involvement (AAI) is not specifically addressed in the current Stanford classification. The Stanford group recommended surgical intervention in patients with type B dissection and AAI [4]. Optimal surgical management of type B dissection with AAI alone or concomitant with proximal aortic lesions is controversial. The repair of aortic arch dissection or simultaneous proximal aortic lesions and descending dissection through a median sternotomy or lateral thoracotomy using a conventional single-stage procedure is troublesome. Rupture of the remaining aneurysmal aorta during the interval between the first and second stage of the procedure has been observed, leading to death. Long-term outcome of debranching of
Accepted for publication March 11, 2010. *LiZhong Sun and Xin Zhao contributed equally to this work. Address correspondence to Dr LZ Sun, Beijing Aortic Disease Center, Beijing Anzhen Hospital, Capital Medical University, 2 Anzhen Rd, Beijing 100029, China; e-mail: [email protected].
© 2010 by The Society of Thoracic Surgeons Published by Elsevier Inc
Patients and Methods The procedure described was approved by the Institutional Review Board of the Chinese Academy of Medical Science and Peking Union Medical College in Beijing, China. Informed consent was obtained from each patient.
Patient Data From October 2003 to December 2008, 19 patients (15 men and 4 women) with chronic type B dissection and AAI (Fig 1) underwent total arch replacement combined with stented elephant trunk implantation under hypothermic cardiopulmonary bypass (CPB) and selective cerebral perfusion through a median sternotomy in Fuwai Hospital (Beijing, China). Patients were a mean age of 45 ⫾ 9 years (range, 22 to 59 years). A history of hypertension 0003-4975/$36.00 doi:10.1016/j.athoracsur.2010.03.048
ADULT CARDIAC
Repair of Chronic Type B Dissection With Aortic Arch Involvement Using a Stented Elephant Trunk Procedure
96
SUN ET AL MANAGEMENT FOR TYPE B DISSECTION
Ann Thorac Surg 2010;90:95–100
ADULT CARDIAC
Fig 1. Preoperative computed tomography images of a patient with chronic type B dissection with aortic arch involvement show (A, B, and C, black symbol) the left common carotid artery was involved by aortic dissection and was significantly dilated. (B, C, and D) The aortic arch was involved by aortic dissection. (B, C, D, E, and F) The false lumen was remarkably expanded, and (E and F, black symbol) the ascending aorta was normal.
towards the origin of the innominate artery in 7 patients. Presentation of aortic dissection with the intimal tear in the descending aorta with retrograde extension toward the aortic arch was observed in 16 patients. The aortic dissection with the intimal tear in the aortic arch ex-
was observed in 15 patients and Marfan syndrome in 2. Thirteen patients had proximal aortic lesions (Table 1). Aortic dissection extending retrogradely towards the origin of the left common carotid artery was observed in 12 patients, and aortic dissection extending retrogradely
Table 1. Clinical Profiles of Patients With Chronic Type B Dissection With Aortic Arch Involvement Patient
Interval (mon)
Concomitant Procedures
Age
Symptoms and Findings
Location
1
56
PDA
1
AVR ⫹ AAR
Alive
2
40
PDA
2
Septal myectomy
Alive
3
22
PDA
4
Bentall ⫹ AAR
Alive
4 5 6 7 8
42 43 48 49 48
Hypertension, ascending aorta and AA aneurysm, AI, AS Hypertension, hypertrophic cardiomyopathy Marfan syndrome, ascending aorta and AA aneurysm, AI Hypertension
AVR ⫹ AAR
Alive Alive Alive Alive Alive
9
46
24
AAR
Alive
10
30
Unknown
AAR
Alive
11
52
12
37
13 14
33 56
15 16
43 42
17
52
18
59
19
43
Hypertension Hypertension Hypertension, pulmonary infection, ascending aortic aneurysm, AI Hypertension, ascending aortic aneurysm Hypertension, ascending aortic aneurysm Hypertension, ascending aorta and AA aneurysm Marfan syndrome, aortic root, ascending aorta and AA aneurysm Hypertension Hypertension, coronary artery disease, ascending aortic aneurysm, diabetes Ascending aortic aneurysm Hypertension, ascending aortic aneurysm Hypertension, ascending aortic aneurysm Hypertension, ascending aortic aneurysm Hypertension
PDA PDA AA PDA PDA AA PDA
60 1 2 108 Unknown
Result
PDA
2
AAR
Alive
PDA
1
Bentall ⫹ AAR
Alive
PDA PDA
4 1
AAR ⫹ CABG
Alive Follow-up death
PDA PDA
1 1
AAR AAR
In-hospital death Alive
AA
1
AAR
Alive
PDA
3
AAR
Alive
PDA
1
Alive
AA ⫽ aortic arch; AAR ⫽ ascending aortic replacement; AI ⫽ aortic incompetence; AS ⫽ aortic stenosis; AVR ⫽ aortic valve replacement; CABG ⫽ coronary artery bypass grafting; Interval ⫽ interval between the onset of aortic dissection and the operation; Location ⫽ location of the original intimal tear; PDA ⫽ proximal descending aorta.
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Table 2. Visceral Arteries: From the True Lumen or the False Lumen? Artery Celiac artery Superior mesenteric artery Right renal artery Left renal artery
False
True
Both
7 1 1 6
10 14 16 8
1 3 1 4
tended antegrade to the descending aorta in 3 patients, the dissection extended into the distal descending thoracic aorta in 1 patient, and into the abdominal aorta in 18. The mean interval between the onset of aortic dissection and repair was 18 ⫾ 29 months (range, 1 to 108 months). The visceral arteries and location of entry and reentry were carefully assessed in 18 of 19 patients (Table 2). Appropriate sizing of the stented elephant trunk was close to the diameter of the proximal descending aorta of healthy individuals matched for age, sex, and height. The diameter of the stent graft was larger than that of the true lumen and was smaller than that of the entire aorta as determined by preoperative computed tomography (CT) and intraoperative judgment. Postoperative CT with contrast enhancement was done routinely to evaluate thrombosis and absorption of the false lumen in all patients who survived to hospital discharge, 3 or 6 months postoperatively, and once yearly after hospital discharge.
Surgical Technique The technique for total arch replacement combined with stented elephant trunk implantation has been described in detail by our research group [5, 6]. An intraoperative stent graft (MicroPort Medical Co Ltd, Shanghai, China) and a Meadox Hemashield Platinum 4 Branch Graft (Boston Scientific Inc, Boston, MA) were used in this technique. The stented graft was only 10-cm long. The proximal and distal ends of the surgical stent graft had 1 cm of extra vascular graft to be used for sewing. In brief, patients underwent median sternotomy and total CPB; cannulation of the right axillary artery was used for CPB and selective cerebral perfusion (SCP). After CPB was established, cooling was initiated. The ascending aorta was clamped, and cardiac arrest was initiated with cold cardioplegic solution. Aortic root procedures were done (if necessary). Circulatory arrest was established when the nasopharyngeal temperature reached 18° to 22°C. SCP was started through the right axillary artery, and the brain was perfused at approximately 5 to 10 mL/kg/min. The transverse arch was opened. The distal aorta was transected circumferentially close to the proximal margin of the origin of the left subclavian artery. The stented elephant trunk was implanted into the descending aorta. The anastomosis between the 4-branched prosthetic graft and the descending aorta was accomplished using the open aortic technique. The stented elephant trunk incor-
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porating the distal aorta was firmly attached to the distal end of the 4-branched prosthetic graft using the suture line. Antegrade distal aortic perfusion was commenced using the branch graft. Patients were rewarmed after the left common carotid artery was reconstructed. The innominate artery and left subclavian artery were anastomosed end-to-end to the corresponding limbs of the 4-branched prosthetic graft. The proximal anastomosis was then accomplished.
Results Surgical Data All patients with type B dissection underwent total replacement of the aortic arch combined with stented elephant trunk implantation under hypothermic CPB with SCP. The mean CPB time was 173 ⫾ 27 minutes (range, 125 to 227 minutes), the mean aortic cross-clamp time was 87 ⫾ 19 minutes (range, 50 to 118 minutes), and the mean SCP time was 23 ⫾ 7 minutes (range, 15 to 38 minutes). Concomitant proximal aortic lesions were repaired in all patients (Table 1).
Morbidity and Mortality Thirty-day mortality was 5.26% (1/19). The patient suffered from respiratory failure due to severe pneumonia. Unfortunately, he died of multiple organ failure. Transient neurologic dysfunction was observed in 1 patient. No injury to the spinal cord or visceral malperfusion was observed during the procedure or during follow-up. There was one late death due to acute myocardial infarction during a mean follow-up of 36 ⫾ 12 months (range, 18 to 71 months). One patient with Marfan syndrome with chronic dissection underwent thoracoabdominal aortic replacement 6 months postoperatively.
Imaging Seventeen of 18 patients underwent CT during followup. Obliteration of the false lumen around the stented elephant trunk was observed in 16 patients (94.1%, 16/17). Complete thrombus formation at the diaphragmatic level occurred in 41.2% (7/17) patients during follow-up (Fig 2). The preoperative false lumen of the descending aorta was 3.32 ⫾ 0.80 cm. The diameter of the descending aorta was 3.27 ⫾ 0.67 cm preoperatively vs 4.23 ⫾ 0.78 cm postoperatively. The descending aorta returned to normal in 5 of 17 patients (29.4%) during follow-up after remodeling of the aortic wall. Obvious enlargement of the abdominal aorta was not observed at the level of the superior mesenteric artery compared with preoperative imaging.
Comment Optimal surgical management of type B dissection with AAI alone or concomitant with proximal aortic lesions is controversial. A conventional single-stage procedure has been used for type B dissection with AAI alone or concomitant with proximal aortic lesions. Repairing aor-
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Ann Thorac Surg 2010;90:95–100
ADULT CARDIAC Fig 2. Computed tomography images of a patient with chronic type B dissection with aortic arch involvement (A and E) preoperatively, (B and F) 2 weeks, (C and G) 4 months, and (D and H) 13 months after the operation. (A and E) The true lumen was compressed by the false lumen; (B and F) the false lumen was partially filled with thrombus postoperatively; (C and G) the false lumen was obliterated with thrombus; (D and H) the true lumen was resumed completely, and the descending aorta returned to normal during follow-up.
tic arch dissection or simultaneous proximal aortic lesions and descending dissection through a median sternotomy or lateral thoracotomy is troublesome. Protecting the myocardium and cerebrum through a lateral thoracotomy is also difficult. Bilateral anterior thoracotomy [7] or a median sternotomy combined with lateral thoracotomy [8] may be an option. Despite acceptable early results, these procedures may be too invasive [7, 8]. A staged procedure may be used for type B dissection with AAI. To facilitate subsequent operations after a lateral thoracotomy, elephant trunk implantation has been used as a staged procedure for treatment of this lesion, but complications such as kinking and obstruction of the graft, embolization, and paraplegia have been observed [9]. Deaths due to rupture of the remaining aneurysmal aorta during the interval between the first and second stage of the procedure were recorded. Selecting an appropriated interval between the two procedures was problematic. Some patients failed to return for the second stage of the operation [10]. The technique is also associated with high hospital expenses, and the secondstage procedure is associated with high morbidity and mortality. Debranching of the supraaortic vessels, followed by immediate transfemoral stenting of the aortic arch, has also been recommended for type B dissection with AAI [11], but several factors have to be considered. First, attachment of the endograft to the aortic wall is achieved by the radial force of the stent graft. This increases injury to the aortic wall, particularly in patients with Marfan syndrome. Endoleaks due to the dilatation of fixation zones for endografts can occur. Second, the maneuver is potentially difficult in the aortic arch because of its curvature, movement, and high flow. A higher prevalence of cerebrovascular accidents by embolization of atherosclerotic debris or detachment of soft plaques can occur due to brisk manipulation of the
stent graft introducer in the aortic arch. The mortality rate associated with this hybrid procedure was high due to cerebrovascular events and the greater frequency of type I endoleaks [12–14]. Third, the long-time durability of an end-to-side anastomosis of a graft to the ascending aorta is uncertain. An end-to-side anastomosis has poor hemodynamics compared with an end-to-end anastomosis. Fourth, some patients were unsuitable for this procedure because of small or diseased access iliac arteries. Most importantly, lesions located in the aortic root and the ascending aorta could not been repaired concomitantly. The entire diseased aortic arch is preserved with debranching of the supraaortic vessels. Meanwhile, severe complications were reported during supraaortic debranching and endovascular stenting of the aortic arch and the descending aorta in patients with type B dissection [15]. So we thought this method should be limited to patients who cannot tolerate open operations. Management of type B dissection with AAI was not specifically addressed in the current Stanford classification. In our center, aortic dissection with the intimal tear in the descending aorta, with retrograde extension towards the aortic arch or with the intimal tear in the aortic arch extending antegrade to the descending aorta, was called Stanford type B aortic dissection with aortic arch involvement. To determine the indication and optimal surgical procedure, Stanford type B dissection was divided into subgroup C (complex type with AAI) and subgroup S (simple type without aortic-arch involvement) by Sun and colleagues. The stented elephant trunk has been developed to successfully treat acute [5, 6, 16, 17] and chronic [5, 18] type A dissection by our research group. To avoid development of a retrograde type A dissection, extensive dilatation of the thoracoabdominal aorta, or late recurrence of proximal aortic dissection, we introduced total arch replacement combined with a
stented elephant trunk to treat patients with type B dissection with AAI (subgroup C) alone or concomitant with proximal aortic lesions. Compared with the technique described above, total arch replacement combined with stented elephant trunk implantation for treatment of type B dissection with AAI (subgroup C) alone or concomitant with proximal aortic lesions had several advantages. The biggest advantage of this technique was that it had the characteristics of open surgical treatment and an interventional approach. Replacement of aortic arch dissection and thrombosis of the dissected descending aorta were achieved simultaneously through a median sternotomy. Concomitant proximal aortic lesions were repaired, and protecting the myocardium and cerebrum through a median sternotomy was easy. There were no severe cerebral complications in this group. Complications related to the endografting procedure (eg, cerebrovascular accident, endoleak) could be avoided due to fixation of the stented elephant trunk to the prosthetic graft using the suture line. Death associated with cerebrovascular accidents and endoleaks could also be avoided. The lesions from the heart to the aortic arch were completely removed with this technique. The diameter of the stented elephant trunk was close to the diameter of the proximal descending aorta of healthy individuals matched for age, sex, and height. The radial force exerted by the stented elephant trunk was relatively low, and injury to the aortic wall caused by the stented elephant trunk was small. The use of deep hypothermic circulatory arrest with SCP avoided injury to the aortic wall due to endografting under aortic pulsation. In addition, the patients tended to be younger in this group (mean age, 45 ⫾ 9 years) and would survive longer after a successful operation. So this more aggressive approach might be justified for this group. Accepted surgical outcomes were obtained in this group. Thirty-day mortality was 5.26%. However, surgical treatment of chronic aortic dissection using the stented elephant trunk procedure was controversial due to the visceral arteries and intercostal arteries originating from the false lumen. With respect to spinal cord injury, no paraplegia or paralysis was observed. In our opinion, ischemia in the chronic phase of chronic aortic dissection enhances spinal cord tolerance to subsequent surgical ischemia by collateral circulation in patients with intercostal arteries from the false lumen [18]. In addition, the speed of thrombosis of the false lumen was low in patients with chronic dissection due to the rigid chronic dissected membrane. Collateral circulation of the spinal cord also formed after implantation of the stented elephant trunk into the true lumen of the distal aorta. Also, no visceral ischemia was observed in this group. This may be because reentry must be near the origin of the visceral artery when the visceral artery originated from the false lumen. The reentry was sufficiently large to supply to the visceral artery. Otherwise, symptoms of visceral organ ischemia must occur in the acute phase if insufficient blood flow through the reentry was supplied
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to visceral organs from the false lumen. Collateral arteries also have an important role in this situation [18]. With regard to cerebral injury, no stroke occurred in this study. This may be because SCP had an effective role in brain protection and because of our experience with surgical treatment for type A dissection [5, 6, 16 –18]. Acceptable postoperative results were also obtained. Thrombosis of the false lumen around the stented elephant trunk was observed in most patients. Thrombosis of the false lumen extended gradually to the diaphragmatic level along with extension of follow-up time. Only 1 patient with Marfan syndrome, who had chronic dissection, underwent late thoracoabdominal aortic replacement. The preoperative diameter of the descending aorta exceeded 60 mm in this patient, and the stent graft was used to facilitate staged aortic replacement. Weakness and fragility of the aortic wall also disturb thrombotic closure of the false lumen in the descending aorta in patients with Marfan syndrome. Thrombus formation in the false lumen reduced stress in the aortic wall, preventing subsequent growth of the distal aorta. This retrospective study had limitations. First, the number of patients may be too small to reach definitive conclusions. Second, the follow-up for patients with type B dissection and AAI was limited to a mean of 36 ⫾ 12 months. Longer follow-up is required to validate the effectiveness of this technique for chronic type B dissection with AAI. In conclusion, this technique is safe, effective, and economical. Replacement of aortic arch dissection and thrombosis of the dissected descending aorta was achieved simultaneously. Concomitant proximal aortic lesions were repaired. It enabled protection of the myocardium and cerebrum via a median sternotomy. Favorable surgical outcomes and postoperative results using this technique were obtained in patients with chronic type B dissection and AAI.
References 1. Daily PO, Trueblood HW, Stinson EB, Wuerflein RD, Shumway NE. Management of acute aortic dissections. Ann Thorac Surg 1970;10:237– 47. 2. Elefteriades JA, Lovoulos CJ, Coady MA, Tellides G, Kopf GS, Rizzo JA. Management of descending aortic dissection. Ann Thorac Surg 1999;67:2002–5; discussion 14 –9. 3. Crawford ES, Svensson LG, Coselli JS, Safi HJ, Hess KR. Aortic dissection and dissecting aortic aneurysms. Ann Surg 1988;208:254 –73. 4. Yun KL, Glower DD, Miller DC, et al. Aortic dissection resulting from tear of transverse arch: is concomitant arch repair warranted? J Thorac Cardiovasc Surg 1991;102:355– 68; discussion 68 –70. 5. Liu ZG, Sun LZ, Chang Q, et al. Should the “elephant trunk” be skeletonized? Total arch replacement combined with stented elephant trunk implantation for Stanford type A aortic dissection. J Thorac Cardiovasc Surg 2006;131:107–13. 6. Sun L, Qi R, Chang Q, et al. Surgery for Marfan patients with acute type a dissection using a stented elephant trunk procedure. Ann Thorac Surg 2008;86:1821–5. 7. Kouchoukos NT, Mauney MC, Masetti P, Castner CF. Single-stage repair of extensive thoracic aortic aneurysms: experience with the arch-first technique and bilateral anterior thoracotomy. J Thorac Cardiovasc Surg 2004;128:669 –76.
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8. Hu XP, Chang Q, Zhu JM, Yu CT, Liu ZG, Sun LZ. One-stage total or subtotal aortic replacement. Ann Thorac Surg 2006; 82:542– 6. 9. Crawford ES, Coselli JS, Svensson LG, Safi HJ, Hess KR. Diffuse aneurysmal disease (chronic aortic dissection, Marfan, and mega aorta syndromes) and multiple aneurysm. Treatment by subtotal and total aortic replacement emphasizing the elephant trunk operation. Ann Surg 1990; 211:521–37. 10. Safi HJ, Miller CC, 3rd, Estrera AL, et al. Staged repair of extensive aortic aneurysms: morbidity and mortality in the elephant trunk technique. Circulation 2001;104:2938 – 42. 11. Iannelli G, Monaco M, Di Tommaso L, Piscione F. Complicated acute type B aortic dissection involving the arch: treatment by simultaneous hybrid approach under local anesthesia. J Thorac Cardiovasc Surg 2008;135:1380 –2. 12. Melissano G, Bertoglio L, Civilini E, et al. Results of thoracic endovascular grafting in different aortic segments. J Endovasc Ther 2007;14:150 –7.
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13. Melissano G, Civilini E, Bertoglio L, et al. Results of endografting of the aortic arch in different landing zones. Eur J Vasc Endovasc Surg 2007;33:561– 6. 14. Saleh HM, Inglese L. Combined surgical and endovascular treatment of aortic arch aneurysms. J Vasc Surg 2006;44:460–6. 15. Akhyari P, Kamiya H, Heye T, Lichtenberg A, Karck M. Aortic dissection type A after supra-aortic debranching and implantation of an endovascular stent-graft for type B dissection: A word of caution. J Thorac Cardiovasc Surg 2009;137:1290 –2. 16. Sun L, Qi R, Chang Q, et al. Surgery for acute type A dissection with the tear in the descending aorta using a stented elephant trunk procedure. Ann Thorac Surg 2009;87:1177–80. 17. Sun L, Qi R, Chang Q, et al. Surgery for acute type A dissection using total arch replacement combined with stented elephant trunk implantation: experience with 107 patients. J Thorac Cardiovasc Surg 2009;138:1358 – 62. 18. Sun L, Qi R, Chang Q, et al. Is total arch replacement combined with stented elephant trunk implantation justified for patients with chronic Stanford type A aortic dissection? J Thorac Cardiovasc Surg 2009;138:892– 6.
INVITED COMMENTARY The combination of aortic arch involvement with a chronic type B aortic dissection is a relatively common scenario whose treatment remains somewhat problematic. Management of the aortic arch or more proximal lesions may be difficult from a thoracotomy exposure, and treatment of the dilated proximal descending thoracic aorta by performing a sternotomy can also be challenging. Combined incisions (thoracosternotomy or bilateral anterior thoracotomy) are associated with increased morbidity. Arch debranching with stent grafting seems to require a similar arch exposure with compromised durability. The authors’ approach [1] seems to provide many advantages. Sternotomy incisions are reasonably well tolerated, more proximal lesions can be managed simultaneously, and the stented elephant trunk appears to stabilize downstream pathology in the majority of patients. One exception would be in Marfan or other syndromic patients, in which the stent grafts are known to function poorly. Implantation of a 10-cm long elephant trunk was not associated with paraplegia or malperfusion syndromes, and promoted false lumen thrombosis for the length of the stent graft in 16 of 17 patients, and thrombosis of the entire thoracic aortic false lumen in 7 of 17. This may then obviate the necessity for further surgical management of the chronic dissection in a substantial proportion of these problematic patients. The only difficulty with this approach is that it requires a stent graft with an extra centimeter of attached regular vascular graft, proximally and distally, to which a conventional hand-sewn anastomosis can be performed. No such graft is available in North America. We have ap-
© 2010 by The Society of Thoracic Surgeons Published by Elsevier Inc
proached these patients in a very similar manner, but have used a long elephant trunk instead of a stent graft. We then compress the elephant trunk within an endoluminal snare threaded into the arch through the true lumen from a femoral puncture, and we pull it distally into the true lumen of the descending thoracic aorta under direct vision. Then this can be easily sewn to a triple-branched arch graft in the conventional manner. Although an unstented elephant trunk may not be as effective in stabilizing the dissection septum and promoting false lumen thrombosis, this procedure has promoted false lumen thrombosis in the majority of cases, and it can be further expanded or lengthened with a transfemorally placed stent graft at a later date, if necessary. The authors [1] are to be congratulated for their combined approach in the management of a difficult patient population. Robert Scott Mitchell, MD Department of Cardiothoracic Surgery Stanford University Medical Center Falk CVRC 300 Pasteur Dr Stanford, CA 94305 e-mail: [email protected]
Reference 1. Sun LZ, Zhao X, Chang Q, et al. Repair of chronic type B dissection with aortic arch involvement using a stented elephant trunk procedure. Ann Thorac Surg 2010;90:95–100.
0003-4975/$36.00 doi:10.1016/j.athoracsur.2010.03.089