- Email: [email protected]
Modified and “Reverse” Frozen Elephant Trunk Repairs for Extensive Disease and Complications After Stent Grafting
Brian Lima, MD, Eric E. Roselli, MD, Edward G. Soltesz, MD, MPH, Douglas R. Johnston, MD, Akshat C. Pujara, MD, Jahanzaib Idrees, BS, and Lars G. Svensson, MD, PhD Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio
Background. The frozen elephant trunk (FET) repair technique combines conventional arch repair with the patient under circulatory arrest with stent grafting and is increasingly being used to treat extensive thoracic aortic disease. This surgical approach is evolving, including its use for complications after thoracic aortic stent grafting – the so-called reversed frozen elephant trunk (RFET). We evaluated the safety and efficacy of FET and RFET operations in high-risk patients. Methods. Between July 2001 and December 2010, 31 patients underwent FET and 19 patients underwent RFET for extensive thoracic aortic disease. Causes included aneurysm (n ⴝ 32), acute dissection (n ⴝ 17), and rupture (n ⴝ 1). Twenty-three cases (46%) were for urgent or emergency indications. Patient data and outcomes were collected through a prospectively maintained clinical database and 3-dimensional analysis of computed tomography (CT) scans. Outcomes were assessed using Kaplan-Meier methodology.
Results. In-hospital mortality was 8% (n ⴝ 4, including 1 emergency RFET procedure for aortic rupture and 2 urgent FET procedures for symptomatic degenerative aneurysm). Stroke occurred in 5 patients (10%) and spinal cord injury in 4 patients (8%). Mean hospital stay was 14.3 days (range 4 to 67 days). Five endoleaks were observed (4 type II, 1 type I) requiring 2 endovascular reinterventions. Mean follow-up was 17 months (range, 1 to 76 months) and actuarial survival was 87% at 2 years. Conclusions. Frozen elephant trunk repair is an effective surgical strategy for managing high-risk patients with extensive pathologic conditions of the thoracic aorta. The RFET approach is a feasible option for proximal aortic complications after previous descending stent grafting. Intermediate outcomes are reasonable for both approaches and further evaluation of these techniques is warranted. (Ann Thorac Surg 2012;93:103–9) © 2012 by The Society of Thoracic Surgeons
T
A frequently reported limitation of the 2-stage elephant trunk procedure is that a number of patients do not undergo the second-stage operation [2, 5, 6]. This is primarily attributable to patient comorbid conditions that preclude another major operation. Furthermore, interval mortality between stages can approach 16%, and the cumulative mortality associated with 2 surgical procedures of this magnitude also ranges between 10% and 16%. Svensson and colleagues [2] demonstrated that failure to complete the second stage severely affected long-term survival, with survival of only 34% compared with 75% in patients who successfully underwent second-stage completion. An alternative option, espoused by Kouchoukous and colleagues [7], entails single-stage aortic repair through a bilateral anterior thoracotomy. Outcomes, however, are
he 2-stage elephant trunk procedure has been the preferred surgical technique for multifocal thoracic aortic disease spanning the ascending segments, the arch, and the descending segments. This staged approach classically entails an initial operation through a median sternotomy with prosthetic replacement of the ascending aorta and aortic arch, leaving a free-floating elephant trunk extension of the arch graft within the descending aorta [1, 2]. This graft extension serves as the site of proximal anastomosis during the second-stage operation, facilitating distal repair. The “reversed” elephant trunk modification refers to scenarios in which the descending aortic segment must be repaired first because of disproportionate aneurysm enlargement, refractory symptoms, or imminent rupture [3, 4].
Accepted for publication Aug 11, 2011. Presented at the Fifty-seventh Annual Meeting of the Southern Thoracic Surgical Association, Orlando, FL, Nov 3– 6, 2010. Address correspondence to Dr Roselli, Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic, 9500 Euclid Ave, Desk J4-1, Cleveland, OH 44195-5108; e-mail: [email protected].
© 2012 by The Society of Thoracic Surgeons Published by Elsevier Inc
Dr Roselli discloses that he has financial relationships with Cook and Medtronic.
0003-4975/$36.00 doi:10.1016/j.athoracsur.2011.08.034
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beset with considerable postoperative respiratory and renal failure. In recent years endovascular techniques have emerged as viable treatment strategies for a wide array of thoracic aortic diseases with the potential for reduced morbidity [8]. This has included the hybrid use of endovascular techniques for elephant trunk completion [9]. The frozen elephant trunk (FET) technique is another hybrid procedure performed in a single stage designed to overcome some of the limitations associated with its 2-stage predecessor [10]. Through a median sternotomy an endograft is deployed antegrade through the transected arch with the patient in deep hypothermic circulatory arrest. This stented elephant trunk is thereby fixed or “frozen” in the descending aorta, with proximal suture fixation of the device to the native aorta completed by conventional proximal aortic replacement. A number of published FET case series from Asia and Europe [11–18] have yielded promising early results that substantiate this technique, but the majority of these procedures used the E-vita hybrid prosthesis (JOTEC GmbH, Hechingen, Germany), which is not commercially available in the United States [12]. At our institution, modified FET procedures are being performed with commercially available stent graft devices. This modified FET technique has also been implemented in extended repair of acute aortic dissections. Additionally, the reversed modification of the FET technique (RFET) has been used for the management of proximal aortic complications, such as endoleaks and retrograde dissection, after descending aortic stent grafting. This surgical variation represents the endovascular/ hybrid analog of the reversed modification of the classic open 2-stage elephant trunk technique [2, 3]. The objective of the present study was to evaluate the safety and efficacy of FET and RFET repair in high-risk patients with complex thoracic aortic disease and complications after descending aorta stent grafting.
Patients and Methods Patients From July 2001 through December 2010, 50 patients underwent FET repair for the treatment of extensive aortic disease. Of these patients, 19 had previously placed stent grafts in the descending aorta and underwent RFET repair. Data are prospectively collected into the Cardiovascular Information Registry, which is approved by the Institutional Review Board of the Cleveland Clinic, and the need for informed consent was waived for this study. Relevant preoperative patient characteristics and indications for surgical intervention are summarized in Table 1. Twenty-three (46%) of the 50 patients were treated for emergency or urgent indications, defined as acute dissection (n ⫽ 11), rupture (n ⫽ 1), or impending rupture based on persistent symptoms or radiographic findings indicative of a rapidly enlarging aneurysm, or both. For the RFET patients, median interval from stent grafting to a second-stage procedure (ascending aorta/arch repair) was 2.3 months (interquar-
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Table 1. Preoperative Patient Characteristics Variable Mean age, year (range) Male patients Previous cardiac or aortic surgery Maximum aortic diameter (cm, mean ⫾ SD) Single-stage FET repair Indication for repair Degenerative aneurysm Chronic dissection with aneurysm Acute dissection Postcoarctation repair aneurysm Kommerell’s aneurysm Surgical urgency Elective Urgent/emergency RFET Indication for repair Degenerative aneurysm Chronic dissection with aneurysm Acute dissection Kommerell’s aneurysm Ruptured aneurysm Surgical urgency Elective Urgent/emergency a
No. of Patients (%) N ⫽ 50 61 (29–87) 33 (66) 23 (46) 6.0 ⫾ 1.3 n ⫽ 31 13 (42) 4 (13)a 11 (35) 7 (23) 2 (6) 17 (55) 14 (45) n ⫽ 19 4 (21) 10 (53)a 6 (32) 1 (5)a 1 (5) 10 (53) 9 (47)
Not mutually exclusive of other indications.
FET ⫽ frozen elephant trunk; RFET ⫽ reversed frozen elephant trunk; SD ⫽ standard deviation.
tile range [IQR], 0.23 to 7 months). Eight of the patients undergoing RFET repair either had a planned singlestage procedure (N ⫽ 2) or underwent the second stage during the same hospitalization as the stent grafting.
Operative Strategy For FET repair, direct aortic stent graft delivery was performed as described previously [9]. Briefly, a 5F sheath is placed in the common femoral artery and retrograde access is obtained into the ascending aorta with a 100-cm catheter placed either by transesophageal echocardiographic guidance alone or transesophageal echocardiography in combination with fluoroscopy. The right axillary artery is the favored site for arterial cannulation through an 8-mm side graft. The patient is placed on cardiopulmonary bypass and cooled to profound hypothermia (⬍20°C). Once adequate cooling is achieved as assessed by electroencephalographic monitoring, the circulation is arrested. Perfusion data are provided in Table 2. Through-and-through wire access is then obtained through the open aorta during the circulatory arrest period through this previously placed catheter. For cases using antegrade or retrograde cerebral perfusion, or both, flow rates were maintained at 750 mL to 1 L/min (pressure 40 to 60 mm Hg) and 200 to 500 mL/min (central venous pressure 25 to 35 mm Hg), respectively. The
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Table 2. Perfusion Data CPB FET (n ⫽ 31) RFET (n ⫽ 19)
CPB (min) Mean ⫾ SD
Circulatory Arrest (min) Mean ⫾ SD
ABP (min) Mean ⫾ SD
RBP No. of Patients (%)
178 ⫾ 31 165 ⫾ 71
33 ⫾ 11 25 ⫾ 13
35 ⫾ 26 40 ⫾ 27
26 (84) 14 (74)
ABP ⫽ antegrade brain perfusion; CPB ⫽ cardiopulmonary bypass; RFET ⫽ reversed frozen elephant trunk; SD ⫽ standard deviation.
commercially available thoracic stent graft device (GORE TAG, W. L. Gore & Associates, Flagstaff, AZ [n ⫽ 23 patients], Zenith TX2, Cook Medical, Bloomington IN [n ⫽ 21 patients], other [n ⫽ 6 patients]) was then directly deployed into the descending aorta. For the majority of cases (⬎80%), a single stent graft was deployed. Proximal suture fixation of the stent to the native aorta was performed after deployment (Fig 1). Left subclavian artery coverage was necessary in 26 patients (50%). Of these patients, 17 (65%) underwent revascularization through a left common carotid artery (n ⫽ 7) or ascending aorta (n ⫽ 10) to left subclavian artery bypass. Subsequent arch and ascending aortic replacement proceeded using open surgical techniques. All cases consisted of total arch replacement, with the majority of supraaortic branch vessel reconstruction using an island or single Y-graft technique. In cases in which significant ostial atherosclerotic plaque of the arch vessels is evident, individual branch reconstruction technique is used. For both single-stage FET and RFET, the graft used for proximal repair was directly anastomosed to the in situ FET stent graft (Fig 1). The majority of patients (n ⫽ 43, 86%) also underwent concomitant cardiac procedures at the time of FET or RFET repair, including ascending aorta/root replacement (n ⫽ 20, 40%), aortic valve repair/ replacement (n ⫽ 16, 32%), coronary artery bypass grafting (n ⫽ 13, 26%), and other procedures (n ⫽ 18, 36%).
FET ⫽ frozen elephant trunk;
RBP ⫽ retrograde brain perfusion;
values were expressed as number (%). The absolute mean difference in maximum aortic diameter between the last available CT scan and the preoperative CT scan was also calculated. Long-term survival was assessed using the Kaplan-Meier methodology.
Outcome Definitions The primary outcomes of this study were hospital mortality and neurologic complications, which were chosen to address the safety of the operation. Neurologic complications included stroke (neurologic deficit ⬎72 hours with CT documentation) and spinal cord injury (transient or permanent paraparesis or paraplegia). Secondary outcomes included morbidities associated with respiratory and renal complications. Respiratory failure was defined as prolonged ventilatory support necessitating eventual tracheostomy. Renal failure was defined as the need for dialysis. Outcomes were stratified according to type and urgency of repair. Intermediate-term outcomes were also assessed and included survival, change in aortic diameter, false lumen patency, and endoleak necessitating endovascular or open surgical reintervention. Aortic morphologic features were assessed with 3-dimensional reconstruction analysis software (TeraRecon, Foster City, CA).
Statistical Analysis Continuous variables were described as mean ⫾ standard deviation (SD) or median IQR and categorical
Fig 1. (A) Intraoperative image. (B) Postoperative volume-rendered computed tomography 3-dimensional reconstruction depicting proximal suture fixation of the in situ FET with direct anastomosis to the graft for arch replacement. (FET ⫽ frozen elephant trunk; LtSC ⫽ left subclavian artery; SVG to PDA ⫽ saphenous vein graft to posterior descending artery.)
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Results Hospital Mortality and Morbidity Three patients died in the hospital after single-stage FET repair: 1. A 68-year-old woman with saccular arch aneurysm and thoracoabdominal aneurysm encroaching the celiac artery underwent concomitant atrial septal defect closure and ascending aorta-to-celiac artery bypass and had a nonrecoverable hemorrhagic stroke. 2. A 60-year-old man presented after previous pulmonic valvotomy at age 11 years with severe pulmonic stenosis, severe right heart failure, and mycotic pseudoaneuryms involving the ascending and descending aorta and died 1 day after surgery. His procedure included homograft implantation with reconstruction of the right ventricular outflow tract, complicated by refractory coagulopathy and massive hemorrhage precipitating cardiac arrest. 3. A 76-year-old woman with an 8-cm ascending aortic aneurysm abutting the sternum and extending into the arch and proximal descending aorta underwent elective FET repair and died secondary to global mesenteric ischemia postoperatively.
Fig 2. Survival after single-stage or reverse frozen elephant trunk repair.
ative proximal aortic root dissection with rupture into the mediastinum and massive hemorrhage. Hemostasis was performed and her aortic root was also successfully repaired. Hospital outcomes are summarized in Table 3.
Intermediate-Term Outcomes
Only 1 patient died among the RFET group: a 74-year-old man who presented more than 2 years after a previous descending aortic stent graft procedure for a ruptured proximal aortic aneurysm. He underwent emergency repair and died secondary to ischemic stroke. Three of the 4 observed hospital deaths occurred after urgent or emergency repair. Overall mean length of hospital stay was 15.3 days (range, 4 to 67 days), with a mean stay of 6 days (range, 1 to 19 days) in the intensive care unit. Length of hospital stay and intensive care unit stay were similar between patients who underwent single-stage repair and those who underwent RFET repair. Adverse neurologic events occurred in 8 patients (16%), including 5 strokes (10%, cause of death in 2 cases described earlier) and 4 cases (8%) of paraparesis, 3 of which were transient after responding favorably to cerebrospinal fluid drainage and permissive hypertension. Of the 3 nonfatal strokes, 1 occurred in a 73 year-old woman with transverse arch and descending aortic aneurysm who suffered intraoper-
At a mean follow-up of 17 months, actuarial survival was 86% at 2 years (Fig 2). Four patients died after discharge secondary to the following: end-stage emphysema in 1 patient 76 months after surgery, hypertensive crisis with multisystem organ failure in 1 patient 3 months after surgery, and death of unknown cause in 2 patients 50 and 57 months, respectively, after RFET repair. Five endoleaks (4 type II, 1 type I) required 2 late reinterventions, including 1 endovascular stent grafting procedure and 1 carotid artery–to–left subclavian artery bypass. In patients undergoing surgery for dissection with imaging available at least 30 days after surgical intervention, the rate of false lumen thrombosis was 67%. Measured diminution in maximal aortic diameter had a mean absolute value of 1.2 cm.
Comment The hybrid FET procedure was conceived as an alternative therapy to mitigate the cumulative morbidity and mortality of 2 major operations and to provide definitive
Table 3. Early (30-Day) Postoperative Complications FET
Complication Death Stroke Spinal cord injury Respiratory failure Renal failure FET ⫽ frozen elephant trunk;
RFET
Elective N ⫽ 17 (%)
Urgent/Emergency N ⫽ 14 (%)
Elective N ⫽ 10 (%)
Urgent/Emergency N ⫽ 9 (%)
1 (6) 1 (6) 3 (18) 0 (0) 0 (0
2 (14) 3 (21) 1 (7) 1 (7) 3 (21)
0 (0) 0 (0) 0 (0) 0 (0) 0 (0)
1 (11) 1 (11) 0 (0) 1 (11) 0 (0)
RFET ⫽ reversed frozen elephant trunk.
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Table 4. Early Outcomes of Frozen Elephant Trunk Series Authors Outside United States Di Bartolomeo et al [12] Shimamura et al [15] Baraki et al [11] Liu et al [14] Uchida et al [16] Flores et al [13] In United States Roselli et al [9] Pochettino et al [26] Lima et al (current study) Total
Year
No. Patients
Mortality (%)
Stroke (%)
Spinal Cord Injury (%)
Emergency Procedure (%)
2009 2008 2007 2006 2006 2006
34 126 39 60 35 25
6 3 13 3 6 12
0 6 13 5 0 16
9 6 0 2 0 24
6 25 18 60 100 0
2010 2009 2011
16 36 50
6 14 8
13 3 10
6 9 8
62 100 46
426
6
6
6
...
single-stage repair of multisegment thoracic aortic disease through a median sternotomy. As stent grafts have become more commonly used and the limits of their application extended, more patients are presenting with late proximal aortic complications [19, 20]. Outcomes of the modified FET repair technique using commercially available stent grafts and the salvage procedure RFET observed in this study compare favorably with those reported in other published series of FET repair (Table 4) [11–17]. Overall in-hospital mortality was 8% for this patient cohort, with 3 of the 4 observed deaths occurring in emergency procedures. In-hospital mortality was 2% for electively performed single-stage FET or RFET repairs. Shimamura and associates [15] from Japan published the largest series of single-stage FET repairs (N ⫽ 126) and reported an outstanding 30-day and in-hospital mortality of 3.2% and 5.5%, respectively. The patient population in the current study differed from theirs in that there were a greater proportion of emergency procedures (56% versus 29%), redo sternotomies (24% versus 5%), and concomitant cardiac procedures (84% versus 0%). Additionally at later follow-up the observed mortality rate at 6 months was 19% in their patient cohort compared with 14% in the current series. A number of the later deaths in that study were related to aortic complications, including aneurysm rupture beyond the treated segment (n ⫽ 3) and aortoesophageal fistula (n ⫽ 1). For the survivors of these complex operations, intermediate survival has been excellent, but as is true of any patient with extensive aortic disease or a stent graft in place, or both, close imaging follow-up is paramount. Unfortunately, spinal cord injury was not avoidable in this cohort, but the majority (75%) of the occurrences of paraparesis were transient (8% overall). The incidence of this complication is similar to that found in most other experiences, including that of Shimamura and associates [15, 21] (Table 4). Three of the 4 patients in the current series underwent previous aortic procedures, a known risk for spinal cord injury [22]. The patients who experi-
enced transient paraparesis had all undergone abdominal aneurysm repair in the past. One patient also had previous descending thoracic aneurysm repair several years earlier, 1 patient presented with acute type A dissection, and 1 patient underwent extensive descending aorta coverage, all of which likely rendered their spinal cords increasingly susceptible to ischemia because of compromised collateral flow. Fortunately these 3 patients responded to emergency placement of an intrathecal drainage catheter and induced hypertension in the intensive care unit. The disproportionately elevated incidence of spinal cord injury (24%) noted in the series of Flores and associates [13] may be directly attributable to the greater proportion (40%) of patients with previous aortic repairs in that study. The authors cited previous abdominal aneurysm repair and a distal landing zone below T7 as independent risk factors for spinal cord injury after FET repair. We now place spinal drains the day before surgery for patients at risk because of previous aortic repair so that we can institute these measures immediately after stent graft deployment. Moreover if the aortic coverage will extend into the distal half of the thoracic aorta, we avoid performing the FET procedure. For these patients, our preferred treatment option is a 2-staged repair, with endovascular elephant trunk completion as the second stage [23]. By deferring the descending repair at least until after the perioperative edema has abated, we think that the risk of spinal cord injury is reduced. The stroke rate was higher than anticipated but is comparable to most series [21] (Table 4). Of the 5 strokes, only 1 occurred in the electively performed cases (1 of 27, 3.7%). This patient was a 72-year-old woman with chronic dissection, and preoperative imaging demonstrating chronic small vessel (intracerebral) disease by magnetic resonance imaging and moderate bilateral internal carotid stenosis with heterogeneous plaque by duplex ultrasonography. The other 4 strokes occurred in the setting of emergency operations for acute dissection (n ⫽
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2), aneurysm rupture (n ⫽ 1), and symptomatic aneurysm (n ⫽ 1). Dialysis-dependent renal failure and respiratory failure requiring tracheostomy each occurred in 6% and 4% of patients, respectively. The rates of similarly defined renal and respiratory failure in the study of Shimamura and colleagues [15] were 4.8% and 6.3%, respectively. All 3 patients in whom renal failure developed in our study were undergoing emergency FET repairs performed for acute dissection. One patient had preexisting renal failure and the other 2 patients eventually recovered renal function. Interestingly, all 3 patients with respiratory failure were also emergency cases for acute dissection, including 1 RFET repair. It is also important to relate the incidence of these complications to alternative singlestage approaches in extensive thoracic aortic disease. In the 2 recently published series of electively performed single-stage total aortic repair by bilateral anterior thoracotomy, Kouchoukos and associates [7, 24] reported rates of renal failure and respiratory failure as high as 10% and 18%, respectively.
RFET The RFET was a modification proposed for patients in whom the distal aorta must be replaced first because of refractory symptoms or actual or impending rupture [3, 25]. Advancements in endovascular stent graft technology and operator skill set have ushered in a veritable shift in the treatment paradigm of complex thoracic aortic disease. Increasingly patients are presenting with proximal aortic complications, including proximal endoleaks, migration, and retrograde dissections. These patients with diffuse aortic pathologic conditions can be safely treated with open reconstruction under circulatory arrest by suturing the conventional graft to the previously placed stent graft. In the current study, reasonably low (5%) mortality was observed despite the urgent/ emergency indications for nearly half of the cases. The single early mortality in our RFET series occurred in a patient with a ruptured proximal aneurysm who survived the repair but succumbed to the neurologic sequelae of an ischemic stroke. Based on the successes and refinement of technique in these urgent indications, elective RFET was developed to address patients with small true lumens after chronic dissections. The endovascular facet of the RFET approach offers a readily discernible advantage over the open reversed elephant trunk. Specifically, this initial minimally invasive component facilitates completion of the 2 stages given the markedly reduced period of recovery required compared with a left thoracotomy. In fact most patients could likely have their second stage proximal repair completed during the same hospitalization. Such was the case for 50% of the patients presented in this series. By expanding this approach to a number of patients who eventually require all segments of the thoracic aorta repaired, the RFET approach will play an increasingly important role in this challenging patient population. More long-term studies with larger patient cohorts comparing this approach with
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open techniques will be necessary to assess this operation.
Limitations of the Study The primary objective of this study was to convey our early experience with the modified FET repair as well as with the novel reversed adaptation of this technique. As such the study design was retrospective in nature, with all the implicit biases such methodologies impart. This study was composed of a relatively small group of patients, thus meaningful comparisons with outcomes from other larger series may be deemed scientifically unsound. Interpretation of results from this study is further hampered by the lack of a contemporaneous control group, ie, patients undergoing the classic, 2-stage elephant trunk procedure. Moreover, long-term outcomes were not evaluated in this study and therefore the durability of FET repairs requires ongoing evaluation.
Conclusions Single-stage FET repair represents an alternative surgical strategy for the management of high-risk patients with extensive pathologic conditions of the thoracic aorta who are traditionally offered a 2-stage open approach. Results from the present study suggest that FET using commercially available stent grafts can be successfully performed with reasonably low morbidity and mortality. For patients with multifocal disease of the thoracic aorta necessitating distal aortic repair first or for those who experience proximal aortic complications after descending aortic stent grafting, the reversed modification of the FET repair is a safe and effective strategy that facilitates timely completion of proximal aortic repair.
References 1. Svensson LG. Rationale and technique for replacement of the ascending aorta, arch, and distal aorta using a modified elephant trunk procedure. J Card Surg 1992;7:301–12. 2. Svensson LG, Kim KH, Blackstone EH, et al. Elephant trunk procedure: newer indications and uses. Ann Thorac Surg 2004;78:109 –16. 3. Carrel T, Berdat P, Kipfer B, et al. The reversed and bidirectional elephant trunk technique in the treatment of complex aortic aneurysms. J Thorac Cardiovasc Surg 2001;122:587–91. 4. Coselli JS, LeMaire SA, Carter SA, Conklin LD. The reversed elephant trunk technique used for treatment of complex aneurysms of the entire thoracic aorta. Ann Thorac Surg 2005;80:2166 –72. 5. Karck M, Kamiya H. Progress of the treatment for extended aortic aneurysms; is the frozen elephant trunk technique the next standard in the treatment of complex aortic disease including the arch? Eur J Cardiothorac Surg 2008;33:1007–13. 6. Safi HJ, Miller CC 3rd, Estrera AL, et al. Optimization of aortic arch replacement: two-stage approach. Ann Thorac Surg 2007;83:S815– 8; discussion S824 –31. 7. Kouchoukos NT, Mauney MC, Masetti P, Castner CF. Optimization of aortic arch replacement with a one-stage approach. Ann Thorac Surg 2007;83:S811– 4; discussion S824 –31. 8. Svensson LG, Kouchoukos NT, Miller DC, et al. Expert consensus document on the treatment of descending thoracic aortic disease using endovascular stent-grafts. Ann Thorac Surg 2008;85:S1– 41.
9. Roselli EE, Soltesz EG, Mastracci T, Svensson LG, Lytle BW. Antegrade delivery of stent grafts to treat complex thoracic aortic disease. Ann Thorac Surg 2010;539 – 46. 10. Karck M, Chavan A, Hagl C, Friedrich H, Galanski M, Haverich A. The frozen elephant trunk technique: a new treatment for thoracic aortic aneurysms. J Thorac Cardiovasc Surg 2003;125:1550 –3. 11. Baraki H, Hagl C, Khaladj N, et al. The frozen elephant trunk technique for treatment of thoracic aortic aneurysms. Ann Thorac Surg 2007;83:S819 –23; discussion S824 –31. 12. Di Bartolomeo R, Di Marco L, Armaro A, et al. Treatment of complex disease of the thoracic aorta: the frozen elephant trunk technique with the E-vita open prosthesis. Eur J Cardiothorac Surg 2009;35:671– 6. 13. Flores J, Kunihara T, Shiiya N, Yoshimoto K, Matsuzaki K, Yasuda K. Extensive deployment of the stented elephant trunk is associated with an increased risk of spinal cord injury. J Thorac Cardiovasc Surg 2006;131:336 – 42. 14. 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. 15. Shimamura K, Kuratani T, Matsumiya G, et al. Long-term results of the open stent-grafting technique for extended aortic arch disease. J Thorac Cardiovasc Surg 2008;135: 1261–9. 16. Uchida N, Ishihara H, Shibamura H, Kyo Y, Ozawa M. Midterm results of extensive primary repair of the thoracic aorta by means of total arch replacement with open stent graft placement for an acute type a aortic dissection. J Thorac Cardiovasc Surg 2006;131:862–7. 17. Uchida N, Shibamura H, Katayama A, Shimada N, Sutoh M, Ishihara H. Operative strategy for acute type a aortic dissection:
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ascending aortic or hemiarch versus total arch replacement with frozen elephant trunk. Ann Thorac Surg 2009;87:773–7. Schepens MA. Editorial comment will the elephant trunk become frozen? Eur J Cardiothorac Surg 2011;40:11–2. Dong ZH, Fu WG, Wang YQ, et al. Retrograde type a aortic dissection after endovascular stent graft placement for treatment of type b dissection. Circulation 2009;119:735– 41. Eggebrecht H, Thompson M, Rousseau H, et al. Retrograde ascending aortic dissection during or after thoracic aortic stent graft placement: insight from the European Registry on Endovascular Aortic Repair Complications. Circulation 2009; 120:S276 – 81. Schoder M, Lammer J, Czerny M. Endovascular aortic arch repair: hopes and certainties. Eur J Vasc Endovasc Surg 2009;38:255– 61. Greenberg RK, Lu Q, Roselli EE, et al. Contemporary analysis of descending thoracic and thoracoabdominal aneurysm repair: comparison of endovascular and open techniques. Circulation 2008;118:808 –17. Roselli EE, Subramanian S, Anderson J, et al. Endovascular versus open elephant trunk completion for extensive aortic disease. Presented at the 36th Annual Western Thoracic Surgical Association Meeting, Ojai, California, June 25, 2010. Kouchoukos NT, Masetti P, Mauney MC, Murphy MC, Castner CF. One-stage repair of extensive chronic aortic dissection using the arch-first technique and bilateral anterior thoracotomy. Ann Thorac Surg 2008;86:1502–9. Coselli JS, Oberwalder P. Successful repair of mega aorta using reversed elephant trunk procedure. J Vasc Surg 1998; 27:183– 8. Pochettino A, Brinkman WT, Moeller P, et al. Antegrade thoracic stent grafting during repair of acute Debakey I dissection prevents development of thoracoabdominal aortic aneurysms. Ann Thorac Surg 2009;88:482–90.
DISCUSSION DR TOMAS D. MARTIN (Gainesville, FL): I noticed that you had a 13% stroke rate. Were those embolic in nature? DR LIMA: All 5 were embolic. DR MARTIN: In looking back on this, I know they were emergencies, but was there some reason that these embolic strokes were higher in this group than in the standard TEVAR or even in the elephant trunk group, and is there anything you might think about doing differently? DR LIMA: Well, 1 single stroke that occurred on an elective repair was in an elderly woman with significant intracranial occlusive disease as well as bilateral carotid stenosis. With regard to the other 4 strokes in emergency cases, we didn’t have adequate preoperative imaging for stroke assessment. For elective cases it would be preferable to complete a more thorough preoperative risk assessment before deciding to proceed with a procedure of this complexity.
DR MARTIN: I don’t know if anybody else has any comments, Dr Roselli, anybody have any comments as to perfusion techniques, because you can do all the workup you want, but most of these embolic strokes come from manipulation of the arch or atheroma or debris in your frozen elephant trunk when you are doing it. DR ROSELLI: The strokes that we saw in most of these patients (and part of the reason why we selected this approach for these patients) is because they were the kind of patients who had the very diffusely atherosclerotic aortas. When you open it up, it looks like a bomb went off in there with saccular aneurysms and soft atheromatous debris throughout the aorta. The thought was that by using circulatory arrest and limiting the amount of manipulation of the aorta in these people that we could reduce their stroke risk, but we still had strokes in some of these folks, and so I think some of these patients with just really horrible aortas are better off just letting them be, but not all of the strokes were devastating either. We need to be better able to predict stroke in these patients.
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Background. The frozen elephant trunk (FET) repair technique combines conventional arch repair with the patient under circulatory arrest with stent grafting and is increasingly being used to treat extensive thoracic aortic disease. This surgical approach is evolving, including its use for complications after thoracic aortic stent grafting – the so-called reversed frozen elephant trunk (RFET). We evaluated the safety and efficacy of FET and RFET operations in high-risk patients. Methods. Between July 2001 and December 2010, 31 patients underwent FET and 19 patients underwent RFET for extensive thoracic aortic disease. Causes included aneurysm (n ⴝ 32), acute dissection (n ⴝ 17), and rupture (n ⴝ 1). Twenty-three cases (46%) were for urgent or emergency indications. Patient data and outcomes were collected through a prospectively maintained clinical database and 3-dimensional analysis of computed tomography (CT) scans. Outcomes were assessed using Kaplan-Meier methodology.
Results. In-hospital mortality was 8% (n ⴝ 4, including 1 emergency RFET procedure for aortic rupture and 2 urgent FET procedures for symptomatic degenerative aneurysm). Stroke occurred in 5 patients (10%) and spinal cord injury in 4 patients (8%). Mean hospital stay was 14.3 days (range 4 to 67 days). Five endoleaks were observed (4 type II, 1 type I) requiring 2 endovascular reinterventions. Mean follow-up was 17 months (range, 1 to 76 months) and actuarial survival was 87% at 2 years. Conclusions. Frozen elephant trunk repair is an effective surgical strategy for managing high-risk patients with extensive pathologic conditions of the thoracic aorta. The RFET approach is a feasible option for proximal aortic complications after previous descending stent grafting. Intermediate outcomes are reasonable for both approaches and further evaluation of these techniques is warranted. (Ann Thorac Surg 2012;93:103–9) © 2012 by The Society of Thoracic Surgeons
T
A frequently reported limitation of the 2-stage elephant trunk procedure is that a number of patients do not undergo the second-stage operation [2, 5, 6]. This is primarily attributable to patient comorbid conditions that preclude another major operation. Furthermore, interval mortality between stages can approach 16%, and the cumulative mortality associated with 2 surgical procedures of this magnitude also ranges between 10% and 16%. Svensson and colleagues [2] demonstrated that failure to complete the second stage severely affected long-term survival, with survival of only 34% compared with 75% in patients who successfully underwent second-stage completion. An alternative option, espoused by Kouchoukous and colleagues [7], entails single-stage aortic repair through a bilateral anterior thoracotomy. Outcomes, however, are
he 2-stage elephant trunk procedure has been the preferred surgical technique for multifocal thoracic aortic disease spanning the ascending segments, the arch, and the descending segments. This staged approach classically entails an initial operation through a median sternotomy with prosthetic replacement of the ascending aorta and aortic arch, leaving a free-floating elephant trunk extension of the arch graft within the descending aorta [1, 2]. This graft extension serves as the site of proximal anastomosis during the second-stage operation, facilitating distal repair. The “reversed” elephant trunk modification refers to scenarios in which the descending aortic segment must be repaired first because of disproportionate aneurysm enlargement, refractory symptoms, or imminent rupture [3, 4].
Accepted for publication Aug 11, 2011. Presented at the Fifty-seventh Annual Meeting of the Southern Thoracic Surgical Association, Orlando, FL, Nov 3– 6, 2010. Address correspondence to Dr Roselli, Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic, 9500 Euclid Ave, Desk J4-1, Cleveland, OH 44195-5108; e-mail: [email protected].
© 2012 by The Society of Thoracic Surgeons Published by Elsevier Inc
Dr Roselli discloses that he has financial relationships with Cook and Medtronic.
0003-4975/$36.00 doi:10.1016/j.athoracsur.2011.08.034
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beset with considerable postoperative respiratory and renal failure. In recent years endovascular techniques have emerged as viable treatment strategies for a wide array of thoracic aortic diseases with the potential for reduced morbidity [8]. This has included the hybrid use of endovascular techniques for elephant trunk completion [9]. The frozen elephant trunk (FET) technique is another hybrid procedure performed in a single stage designed to overcome some of the limitations associated with its 2-stage predecessor [10]. Through a median sternotomy an endograft is deployed antegrade through the transected arch with the patient in deep hypothermic circulatory arrest. This stented elephant trunk is thereby fixed or “frozen” in the descending aorta, with proximal suture fixation of the device to the native aorta completed by conventional proximal aortic replacement. A number of published FET case series from Asia and Europe [11–18] have yielded promising early results that substantiate this technique, but the majority of these procedures used the E-vita hybrid prosthesis (JOTEC GmbH, Hechingen, Germany), which is not commercially available in the United States [12]. At our institution, modified FET procedures are being performed with commercially available stent graft devices. This modified FET technique has also been implemented in extended repair of acute aortic dissections. Additionally, the reversed modification of the FET technique (RFET) has been used for the management of proximal aortic complications, such as endoleaks and retrograde dissection, after descending aortic stent grafting. This surgical variation represents the endovascular/ hybrid analog of the reversed modification of the classic open 2-stage elephant trunk technique [2, 3]. The objective of the present study was to evaluate the safety and efficacy of FET and RFET repair in high-risk patients with complex thoracic aortic disease and complications after descending aorta stent grafting.
Patients and Methods Patients From July 2001 through December 2010, 50 patients underwent FET repair for the treatment of extensive aortic disease. Of these patients, 19 had previously placed stent grafts in the descending aorta and underwent RFET repair. Data are prospectively collected into the Cardiovascular Information Registry, which is approved by the Institutional Review Board of the Cleveland Clinic, and the need for informed consent was waived for this study. Relevant preoperative patient characteristics and indications for surgical intervention are summarized in Table 1. Twenty-three (46%) of the 50 patients were treated for emergency or urgent indications, defined as acute dissection (n ⫽ 11), rupture (n ⫽ 1), or impending rupture based on persistent symptoms or radiographic findings indicative of a rapidly enlarging aneurysm, or both. For the RFET patients, median interval from stent grafting to a second-stage procedure (ascending aorta/arch repair) was 2.3 months (interquar-
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Table 1. Preoperative Patient Characteristics Variable Mean age, year (range) Male patients Previous cardiac or aortic surgery Maximum aortic diameter (cm, mean ⫾ SD) Single-stage FET repair Indication for repair Degenerative aneurysm Chronic dissection with aneurysm Acute dissection Postcoarctation repair aneurysm Kommerell’s aneurysm Surgical urgency Elective Urgent/emergency RFET Indication for repair Degenerative aneurysm Chronic dissection with aneurysm Acute dissection Kommerell’s aneurysm Ruptured aneurysm Surgical urgency Elective Urgent/emergency a
No. of Patients (%) N ⫽ 50 61 (29–87) 33 (66) 23 (46) 6.0 ⫾ 1.3 n ⫽ 31 13 (42) 4 (13)a 11 (35) 7 (23) 2 (6) 17 (55) 14 (45) n ⫽ 19 4 (21) 10 (53)a 6 (32) 1 (5)a 1 (5) 10 (53) 9 (47)
Not mutually exclusive of other indications.
FET ⫽ frozen elephant trunk; RFET ⫽ reversed frozen elephant trunk; SD ⫽ standard deviation.
tile range [IQR], 0.23 to 7 months). Eight of the patients undergoing RFET repair either had a planned singlestage procedure (N ⫽ 2) or underwent the second stage during the same hospitalization as the stent grafting.
Operative Strategy For FET repair, direct aortic stent graft delivery was performed as described previously [9]. Briefly, a 5F sheath is placed in the common femoral artery and retrograde access is obtained into the ascending aorta with a 100-cm catheter placed either by transesophageal echocardiographic guidance alone or transesophageal echocardiography in combination with fluoroscopy. The right axillary artery is the favored site for arterial cannulation through an 8-mm side graft. The patient is placed on cardiopulmonary bypass and cooled to profound hypothermia (⬍20°C). Once adequate cooling is achieved as assessed by electroencephalographic monitoring, the circulation is arrested. Perfusion data are provided in Table 2. Through-and-through wire access is then obtained through the open aorta during the circulatory arrest period through this previously placed catheter. For cases using antegrade or retrograde cerebral perfusion, or both, flow rates were maintained at 750 mL to 1 L/min (pressure 40 to 60 mm Hg) and 200 to 500 mL/min (central venous pressure 25 to 35 mm Hg), respectively. The
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Table 2. Perfusion Data CPB FET (n ⫽ 31) RFET (n ⫽ 19)
CPB (min) Mean ⫾ SD
Circulatory Arrest (min) Mean ⫾ SD
ABP (min) Mean ⫾ SD
RBP No. of Patients (%)
178 ⫾ 31 165 ⫾ 71
33 ⫾ 11 25 ⫾ 13
35 ⫾ 26 40 ⫾ 27
26 (84) 14 (74)
ABP ⫽ antegrade brain perfusion; CPB ⫽ cardiopulmonary bypass; RFET ⫽ reversed frozen elephant trunk; SD ⫽ standard deviation.
commercially available thoracic stent graft device (GORE TAG, W. L. Gore & Associates, Flagstaff, AZ [n ⫽ 23 patients], Zenith TX2, Cook Medical, Bloomington IN [n ⫽ 21 patients], other [n ⫽ 6 patients]) was then directly deployed into the descending aorta. For the majority of cases (⬎80%), a single stent graft was deployed. Proximal suture fixation of the stent to the native aorta was performed after deployment (Fig 1). Left subclavian artery coverage was necessary in 26 patients (50%). Of these patients, 17 (65%) underwent revascularization through a left common carotid artery (n ⫽ 7) or ascending aorta (n ⫽ 10) to left subclavian artery bypass. Subsequent arch and ascending aortic replacement proceeded using open surgical techniques. All cases consisted of total arch replacement, with the majority of supraaortic branch vessel reconstruction using an island or single Y-graft technique. In cases in which significant ostial atherosclerotic plaque of the arch vessels is evident, individual branch reconstruction technique is used. For both single-stage FET and RFET, the graft used for proximal repair was directly anastomosed to the in situ FET stent graft (Fig 1). The majority of patients (n ⫽ 43, 86%) also underwent concomitant cardiac procedures at the time of FET or RFET repair, including ascending aorta/root replacement (n ⫽ 20, 40%), aortic valve repair/ replacement (n ⫽ 16, 32%), coronary artery bypass grafting (n ⫽ 13, 26%), and other procedures (n ⫽ 18, 36%).
FET ⫽ frozen elephant trunk;
RBP ⫽ retrograde brain perfusion;
values were expressed as number (%). The absolute mean difference in maximum aortic diameter between the last available CT scan and the preoperative CT scan was also calculated. Long-term survival was assessed using the Kaplan-Meier methodology.
Outcome Definitions The primary outcomes of this study were hospital mortality and neurologic complications, which were chosen to address the safety of the operation. Neurologic complications included stroke (neurologic deficit ⬎72 hours with CT documentation) and spinal cord injury (transient or permanent paraparesis or paraplegia). Secondary outcomes included morbidities associated with respiratory and renal complications. Respiratory failure was defined as prolonged ventilatory support necessitating eventual tracheostomy. Renal failure was defined as the need for dialysis. Outcomes were stratified according to type and urgency of repair. Intermediate-term outcomes were also assessed and included survival, change in aortic diameter, false lumen patency, and endoleak necessitating endovascular or open surgical reintervention. Aortic morphologic features were assessed with 3-dimensional reconstruction analysis software (TeraRecon, Foster City, CA).
Statistical Analysis Continuous variables were described as mean ⫾ standard deviation (SD) or median IQR and categorical
Fig 1. (A) Intraoperative image. (B) Postoperative volume-rendered computed tomography 3-dimensional reconstruction depicting proximal suture fixation of the in situ FET with direct anastomosis to the graft for arch replacement. (FET ⫽ frozen elephant trunk; LtSC ⫽ left subclavian artery; SVG to PDA ⫽ saphenous vein graft to posterior descending artery.)
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Results Hospital Mortality and Morbidity Three patients died in the hospital after single-stage FET repair: 1. A 68-year-old woman with saccular arch aneurysm and thoracoabdominal aneurysm encroaching the celiac artery underwent concomitant atrial septal defect closure and ascending aorta-to-celiac artery bypass and had a nonrecoverable hemorrhagic stroke. 2. A 60-year-old man presented after previous pulmonic valvotomy at age 11 years with severe pulmonic stenosis, severe right heart failure, and mycotic pseudoaneuryms involving the ascending and descending aorta and died 1 day after surgery. His procedure included homograft implantation with reconstruction of the right ventricular outflow tract, complicated by refractory coagulopathy and massive hemorrhage precipitating cardiac arrest. 3. A 76-year-old woman with an 8-cm ascending aortic aneurysm abutting the sternum and extending into the arch and proximal descending aorta underwent elective FET repair and died secondary to global mesenteric ischemia postoperatively.
Fig 2. Survival after single-stage or reverse frozen elephant trunk repair.
ative proximal aortic root dissection with rupture into the mediastinum and massive hemorrhage. Hemostasis was performed and her aortic root was also successfully repaired. Hospital outcomes are summarized in Table 3.
Intermediate-Term Outcomes
Only 1 patient died among the RFET group: a 74-year-old man who presented more than 2 years after a previous descending aortic stent graft procedure for a ruptured proximal aortic aneurysm. He underwent emergency repair and died secondary to ischemic stroke. Three of the 4 observed hospital deaths occurred after urgent or emergency repair. Overall mean length of hospital stay was 15.3 days (range, 4 to 67 days), with a mean stay of 6 days (range, 1 to 19 days) in the intensive care unit. Length of hospital stay and intensive care unit stay were similar between patients who underwent single-stage repair and those who underwent RFET repair. Adverse neurologic events occurred in 8 patients (16%), including 5 strokes (10%, cause of death in 2 cases described earlier) and 4 cases (8%) of paraparesis, 3 of which were transient after responding favorably to cerebrospinal fluid drainage and permissive hypertension. Of the 3 nonfatal strokes, 1 occurred in a 73 year-old woman with transverse arch and descending aortic aneurysm who suffered intraoper-
At a mean follow-up of 17 months, actuarial survival was 86% at 2 years (Fig 2). Four patients died after discharge secondary to the following: end-stage emphysema in 1 patient 76 months after surgery, hypertensive crisis with multisystem organ failure in 1 patient 3 months after surgery, and death of unknown cause in 2 patients 50 and 57 months, respectively, after RFET repair. Five endoleaks (4 type II, 1 type I) required 2 late reinterventions, including 1 endovascular stent grafting procedure and 1 carotid artery–to–left subclavian artery bypass. In patients undergoing surgery for dissection with imaging available at least 30 days after surgical intervention, the rate of false lumen thrombosis was 67%. Measured diminution in maximal aortic diameter had a mean absolute value of 1.2 cm.
Comment The hybrid FET procedure was conceived as an alternative therapy to mitigate the cumulative morbidity and mortality of 2 major operations and to provide definitive
Table 3. Early (30-Day) Postoperative Complications FET
Complication Death Stroke Spinal cord injury Respiratory failure Renal failure FET ⫽ frozen elephant trunk;
RFET
Elective N ⫽ 17 (%)
Urgent/Emergency N ⫽ 14 (%)
Elective N ⫽ 10 (%)
Urgent/Emergency N ⫽ 9 (%)
1 (6) 1 (6) 3 (18) 0 (0) 0 (0
2 (14) 3 (21) 1 (7) 1 (7) 3 (21)
0 (0) 0 (0) 0 (0) 0 (0) 0 (0)
1 (11) 1 (11) 0 (0) 1 (11) 0 (0)
RFET ⫽ reversed frozen elephant trunk.
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Table 4. Early Outcomes of Frozen Elephant Trunk Series Authors Outside United States Di Bartolomeo et al [12] Shimamura et al [15] Baraki et al [11] Liu et al [14] Uchida et al [16] Flores et al [13] In United States Roselli et al [9] Pochettino et al [26] Lima et al (current study) Total
Year
No. Patients
Mortality (%)
Stroke (%)
Spinal Cord Injury (%)
Emergency Procedure (%)
2009 2008 2007 2006 2006 2006
34 126 39 60 35 25
6 3 13 3 6 12
0 6 13 5 0 16
9 6 0 2 0 24
6 25 18 60 100 0
2010 2009 2011
16 36 50
6 14 8
13 3 10
6 9 8
62 100 46
426
6
6
6
...
single-stage repair of multisegment thoracic aortic disease through a median sternotomy. As stent grafts have become more commonly used and the limits of their application extended, more patients are presenting with late proximal aortic complications [19, 20]. Outcomes of the modified FET repair technique using commercially available stent grafts and the salvage procedure RFET observed in this study compare favorably with those reported in other published series of FET repair (Table 4) [11–17]. Overall in-hospital mortality was 8% for this patient cohort, with 3 of the 4 observed deaths occurring in emergency procedures. In-hospital mortality was 2% for electively performed single-stage FET or RFET repairs. Shimamura and associates [15] from Japan published the largest series of single-stage FET repairs (N ⫽ 126) and reported an outstanding 30-day and in-hospital mortality of 3.2% and 5.5%, respectively. The patient population in the current study differed from theirs in that there were a greater proportion of emergency procedures (56% versus 29%), redo sternotomies (24% versus 5%), and concomitant cardiac procedures (84% versus 0%). Additionally at later follow-up the observed mortality rate at 6 months was 19% in their patient cohort compared with 14% in the current series. A number of the later deaths in that study were related to aortic complications, including aneurysm rupture beyond the treated segment (n ⫽ 3) and aortoesophageal fistula (n ⫽ 1). For the survivors of these complex operations, intermediate survival has been excellent, but as is true of any patient with extensive aortic disease or a stent graft in place, or both, close imaging follow-up is paramount. Unfortunately, spinal cord injury was not avoidable in this cohort, but the majority (75%) of the occurrences of paraparesis were transient (8% overall). The incidence of this complication is similar to that found in most other experiences, including that of Shimamura and associates [15, 21] (Table 4). Three of the 4 patients in the current series underwent previous aortic procedures, a known risk for spinal cord injury [22]. The patients who experi-
enced transient paraparesis had all undergone abdominal aneurysm repair in the past. One patient also had previous descending thoracic aneurysm repair several years earlier, 1 patient presented with acute type A dissection, and 1 patient underwent extensive descending aorta coverage, all of which likely rendered their spinal cords increasingly susceptible to ischemia because of compromised collateral flow. Fortunately these 3 patients responded to emergency placement of an intrathecal drainage catheter and induced hypertension in the intensive care unit. The disproportionately elevated incidence of spinal cord injury (24%) noted in the series of Flores and associates [13] may be directly attributable to the greater proportion (40%) of patients with previous aortic repairs in that study. The authors cited previous abdominal aneurysm repair and a distal landing zone below T7 as independent risk factors for spinal cord injury after FET repair. We now place spinal drains the day before surgery for patients at risk because of previous aortic repair so that we can institute these measures immediately after stent graft deployment. Moreover if the aortic coverage will extend into the distal half of the thoracic aorta, we avoid performing the FET procedure. For these patients, our preferred treatment option is a 2-staged repair, with endovascular elephant trunk completion as the second stage [23]. By deferring the descending repair at least until after the perioperative edema has abated, we think that the risk of spinal cord injury is reduced. The stroke rate was higher than anticipated but is comparable to most series [21] (Table 4). Of the 5 strokes, only 1 occurred in the electively performed cases (1 of 27, 3.7%). This patient was a 72-year-old woman with chronic dissection, and preoperative imaging demonstrating chronic small vessel (intracerebral) disease by magnetic resonance imaging and moderate bilateral internal carotid stenosis with heterogeneous plaque by duplex ultrasonography. The other 4 strokes occurred in the setting of emergency operations for acute dissection (n ⫽
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2), aneurysm rupture (n ⫽ 1), and symptomatic aneurysm (n ⫽ 1). Dialysis-dependent renal failure and respiratory failure requiring tracheostomy each occurred in 6% and 4% of patients, respectively. The rates of similarly defined renal and respiratory failure in the study of Shimamura and colleagues [15] were 4.8% and 6.3%, respectively. All 3 patients in whom renal failure developed in our study were undergoing emergency FET repairs performed for acute dissection. One patient had preexisting renal failure and the other 2 patients eventually recovered renal function. Interestingly, all 3 patients with respiratory failure were also emergency cases for acute dissection, including 1 RFET repair. It is also important to relate the incidence of these complications to alternative singlestage approaches in extensive thoracic aortic disease. In the 2 recently published series of electively performed single-stage total aortic repair by bilateral anterior thoracotomy, Kouchoukos and associates [7, 24] reported rates of renal failure and respiratory failure as high as 10% and 18%, respectively.
RFET The RFET was a modification proposed for patients in whom the distal aorta must be replaced first because of refractory symptoms or actual or impending rupture [3, 25]. Advancements in endovascular stent graft technology and operator skill set have ushered in a veritable shift in the treatment paradigm of complex thoracic aortic disease. Increasingly patients are presenting with proximal aortic complications, including proximal endoleaks, migration, and retrograde dissections. These patients with diffuse aortic pathologic conditions can be safely treated with open reconstruction under circulatory arrest by suturing the conventional graft to the previously placed stent graft. In the current study, reasonably low (5%) mortality was observed despite the urgent/ emergency indications for nearly half of the cases. The single early mortality in our RFET series occurred in a patient with a ruptured proximal aneurysm who survived the repair but succumbed to the neurologic sequelae of an ischemic stroke. Based on the successes and refinement of technique in these urgent indications, elective RFET was developed to address patients with small true lumens after chronic dissections. The endovascular facet of the RFET approach offers a readily discernible advantage over the open reversed elephant trunk. Specifically, this initial minimally invasive component facilitates completion of the 2 stages given the markedly reduced period of recovery required compared with a left thoracotomy. In fact most patients could likely have their second stage proximal repair completed during the same hospitalization. Such was the case for 50% of the patients presented in this series. By expanding this approach to a number of patients who eventually require all segments of the thoracic aorta repaired, the RFET approach will play an increasingly important role in this challenging patient population. More long-term studies with larger patient cohorts comparing this approach with
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open techniques will be necessary to assess this operation.
Limitations of the Study The primary objective of this study was to convey our early experience with the modified FET repair as well as with the novel reversed adaptation of this technique. As such the study design was retrospective in nature, with all the implicit biases such methodologies impart. This study was composed of a relatively small group of patients, thus meaningful comparisons with outcomes from other larger series may be deemed scientifically unsound. Interpretation of results from this study is further hampered by the lack of a contemporaneous control group, ie, patients undergoing the classic, 2-stage elephant trunk procedure. Moreover, long-term outcomes were not evaluated in this study and therefore the durability of FET repairs requires ongoing evaluation.
Conclusions Single-stage FET repair represents an alternative surgical strategy for the management of high-risk patients with extensive pathologic conditions of the thoracic aorta who are traditionally offered a 2-stage open approach. Results from the present study suggest that FET using commercially available stent grafts can be successfully performed with reasonably low morbidity and mortality. For patients with multifocal disease of the thoracic aorta necessitating distal aortic repair first or for those who experience proximal aortic complications after descending aortic stent grafting, the reversed modification of the FET repair is a safe and effective strategy that facilitates timely completion of proximal aortic repair.
References 1. Svensson LG. Rationale and technique for replacement of the ascending aorta, arch, and distal aorta using a modified elephant trunk procedure. J Card Surg 1992;7:301–12. 2. Svensson LG, Kim KH, Blackstone EH, et al. Elephant trunk procedure: newer indications and uses. Ann Thorac Surg 2004;78:109 –16. 3. Carrel T, Berdat P, Kipfer B, et al. The reversed and bidirectional elephant trunk technique in the treatment of complex aortic aneurysms. J Thorac Cardiovasc Surg 2001;122:587–91. 4. Coselli JS, LeMaire SA, Carter SA, Conklin LD. The reversed elephant trunk technique used for treatment of complex aneurysms of the entire thoracic aorta. Ann Thorac Surg 2005;80:2166 –72. 5. Karck M, Kamiya H. Progress of the treatment for extended aortic aneurysms; is the frozen elephant trunk technique the next standard in the treatment of complex aortic disease including the arch? Eur J Cardiothorac Surg 2008;33:1007–13. 6. Safi HJ, Miller CC 3rd, Estrera AL, et al. Optimization of aortic arch replacement: two-stage approach. Ann Thorac Surg 2007;83:S815– 8; discussion S824 –31. 7. Kouchoukos NT, Mauney MC, Masetti P, Castner CF. Optimization of aortic arch replacement with a one-stage approach. Ann Thorac Surg 2007;83:S811– 4; discussion S824 –31. 8. Svensson LG, Kouchoukos NT, Miller DC, et al. Expert consensus document on the treatment of descending thoracic aortic disease using endovascular stent-grafts. Ann Thorac Surg 2008;85:S1– 41.
9. Roselli EE, Soltesz EG, Mastracci T, Svensson LG, Lytle BW. Antegrade delivery of stent grafts to treat complex thoracic aortic disease. Ann Thorac Surg 2010;539 – 46. 10. Karck M, Chavan A, Hagl C, Friedrich H, Galanski M, Haverich A. The frozen elephant trunk technique: a new treatment for thoracic aortic aneurysms. J Thorac Cardiovasc Surg 2003;125:1550 –3. 11. Baraki H, Hagl C, Khaladj N, et al. The frozen elephant trunk technique for treatment of thoracic aortic aneurysms. Ann Thorac Surg 2007;83:S819 –23; discussion S824 –31. 12. Di Bartolomeo R, Di Marco L, Armaro A, et al. Treatment of complex disease of the thoracic aorta: the frozen elephant trunk technique with the E-vita open prosthesis. Eur J Cardiothorac Surg 2009;35:671– 6. 13. Flores J, Kunihara T, Shiiya N, Yoshimoto K, Matsuzaki K, Yasuda K. Extensive deployment of the stented elephant trunk is associated with an increased risk of spinal cord injury. J Thorac Cardiovasc Surg 2006;131:336 – 42. 14. 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. 15. Shimamura K, Kuratani T, Matsumiya G, et al. Long-term results of the open stent-grafting technique for extended aortic arch disease. J Thorac Cardiovasc Surg 2008;135: 1261–9. 16. Uchida N, Ishihara H, Shibamura H, Kyo Y, Ozawa M. Midterm results of extensive primary repair of the thoracic aorta by means of total arch replacement with open stent graft placement for an acute type a aortic dissection. J Thorac Cardiovasc Surg 2006;131:862–7. 17. Uchida N, Shibamura H, Katayama A, Shimada N, Sutoh M, Ishihara H. Operative strategy for acute type a aortic dissection:
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ascending aortic or hemiarch versus total arch replacement with frozen elephant trunk. Ann Thorac Surg 2009;87:773–7. Schepens MA. Editorial comment will the elephant trunk become frozen? Eur J Cardiothorac Surg 2011;40:11–2. Dong ZH, Fu WG, Wang YQ, et al. Retrograde type a aortic dissection after endovascular stent graft placement for treatment of type b dissection. Circulation 2009;119:735– 41. Eggebrecht H, Thompson M, Rousseau H, et al. Retrograde ascending aortic dissection during or after thoracic aortic stent graft placement: insight from the European Registry on Endovascular Aortic Repair Complications. Circulation 2009; 120:S276 – 81. Schoder M, Lammer J, Czerny M. Endovascular aortic arch repair: hopes and certainties. Eur J Vasc Endovasc Surg 2009;38:255– 61. Greenberg RK, Lu Q, Roselli EE, et al. Contemporary analysis of descending thoracic and thoracoabdominal aneurysm repair: comparison of endovascular and open techniques. Circulation 2008;118:808 –17. Roselli EE, Subramanian S, Anderson J, et al. Endovascular versus open elephant trunk completion for extensive aortic disease. Presented at the 36th Annual Western Thoracic Surgical Association Meeting, Ojai, California, June 25, 2010. Kouchoukos NT, Masetti P, Mauney MC, Murphy MC, Castner CF. One-stage repair of extensive chronic aortic dissection using the arch-first technique and bilateral anterior thoracotomy. Ann Thorac Surg 2008;86:1502–9. Coselli JS, Oberwalder P. Successful repair of mega aorta using reversed elephant trunk procedure. J Vasc Surg 1998; 27:183– 8. Pochettino A, Brinkman WT, Moeller P, et al. Antegrade thoracic stent grafting during repair of acute Debakey I dissection prevents development of thoracoabdominal aortic aneurysms. Ann Thorac Surg 2009;88:482–90.
DISCUSSION DR TOMAS D. MARTIN (Gainesville, FL): I noticed that you had a 13% stroke rate. Were those embolic in nature? DR LIMA: All 5 were embolic. DR MARTIN: In looking back on this, I know they were emergencies, but was there some reason that these embolic strokes were higher in this group than in the standard TEVAR or even in the elephant trunk group, and is there anything you might think about doing differently? DR LIMA: Well, 1 single stroke that occurred on an elective repair was in an elderly woman with significant intracranial occlusive disease as well as bilateral carotid stenosis. With regard to the other 4 strokes in emergency cases, we didn’t have adequate preoperative imaging for stroke assessment. For elective cases it would be preferable to complete a more thorough preoperative risk assessment before deciding to proceed with a procedure of this complexity.
DR MARTIN: I don’t know if anybody else has any comments, Dr Roselli, anybody have any comments as to perfusion techniques, because you can do all the workup you want, but most of these embolic strokes come from manipulation of the arch or atheroma or debris in your frozen elephant trunk when you are doing it. DR ROSELLI: The strokes that we saw in most of these patients (and part of the reason why we selected this approach for these patients) is because they were the kind of patients who had the very diffusely atherosclerotic aortas. When you open it up, it looks like a bomb went off in there with saccular aneurysms and soft atheromatous debris throughout the aorta. The thought was that by using circulatory arrest and limiting the amount of manipulation of the aorta in these people that we could reduce their stroke risk, but we still had strokes in some of these folks, and so I think some of these patients with just really horrible aortas are better off just letting them be, but not all of the strokes were devastating either. We need to be better able to predict stroke in these patients.
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