Combined Proximal Endografting With Distal Bare-Metal Stenting for Management of Aortic Dissection

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1 Combined Proximal Endografting With Distal Bare-Metal Stenting for Management of Aortic Dissection ADULT CARDIAC Sophie C. Hofferberth, BS, BMedSc, Peter T. Foley, MBBS, FRANZCR, Andrew E. Newcomb, MBBS, FRACS, Kelvin K. Yap, MBBS, FRANZCR, Michael Y. Yii, MBBS, FRACS, Ian K. Nixon, MBBS, FRACS, Andrew M. Wilson, MBBS, FRACP, and Peter J. Mossop, MBBS, FRACR Department of Medicine (St. Vincent s), The University of Melbourne, Fitzroy; and Departments of Cardiac Surgery and Medical Imaging, St. Vincent s Hospital Melbourne, Fitzroy, Victoria, Australia Background. Established endovascular treatments for aortic dissection often result in incomplete aortic repair, potentially leading to late complications involving the distal aorta. To address the problems of incomplete true lumen reconstitution and late aneurysmal change, we report the midterm results of combined proximal endografting with distal true lumen bare-metal stenting (STABLE: Staged Total Aortic and Branch vessel Endovascular reconstruction) in Stanford type A and B aortic dissection. Methods. Between January 2003 and January 2010, 31 patients underwent staged total aortic and branch vessel endovascular reconstruction for management of acute (type A, 13; type B, 11) and chronic (type B, 7) aortic dissection. Proximal endografting was combined with bare-metal Z stent implantation in the distal true lumen. Patients with type A dissection underwent adjunctive treatment at operation. Computed tomography angiography was performed at baseline, 1 year, and annually thereafter to assess aortic remodelling. Results. Primary technical success was 97%. Thirty-day rates of death, stroke, and permanent paraplegia/paresis were 3% (n 1), 0%, and 0%, respectively. Mean follow-up was 57.3 months (range, 5 to 100 months). Overall survival was 60% at 100 months. Aortic-specific survival was 93%. Four patients (13%) underwent device-related reintervention. One (3%) late aortic-related death occurred. Thoracic (p 0.64) and abdominal (p 0.14) aortic dimensions were stable. The true lumen index increased significantly at follow-up. Conclusions. Staged total aortic and branch vessel endovascular reconstruction is a feasible ancillary endovascular technique to address the problems of distal true lumen collapse, incomplete aortic remodelling, and late aneurysm formation in aortic dissection. (Ann Thorac Surg 2012;93:95 102) 2012 by The Society of Thoracic Surgeons Medical therapy is the established treatment for Stanford type B aortic dissection [1, 2], with intervention reserved for complicated cases [1]. However, late complications will develop in up to 50% of medically treated patients, including rupture, aneurysmal dilatation, and organ malperfusion from branch vessel compromise [3 6]. Similarly, many survivors of type A dissection experience late complications related to delamination and ongoing false lumen perfusion of the distal aorta [7 9]. Stent graft coverage of the proximal entry tear in type B dissection was first reported in 1999 [10], with subsequent series detailing initial technical success for descending aortic dissection [11, 12]. This technique aims to decompress the false lumen with resultant thrombosis and remodelling, defined as stabilization of aortic dimensions [13]. Accepted for publication June 29, Address correspondence to Ms Hofferberth, Department of Medicine (St. Vincent s), The University of Melbourne, Level 4, Clinical Sciences Bldg, 29 Regent St, Fitzroy, Melbourne, Victoria, 3065, Australia; s.hofferberth@ugrad.unimelb.edu.au. Endograft closure may result in incomplete repair, with the abdominal aorta failing to remodel in 50% to 80% of patients [14]. This risks late complications such as repeat dissection, aneurysmal change, and rupture. To address this problem, we have augmented proximal endografting with distal deployment of bare-metal Z stents, a concept termed Staged Total Aortic and Branch vessel Endovascular reconstruction (STABLE). We report the midterm results of this technique for Stanford type A and type B aortic dissection. Patients and Methods The St. Vincent s Hospital Ethics Committee approved this retrospective study and waived the need for individual patient consent. Patient Population Between January 2003 and January 2010, 31 consecutive patients underwent the STABLE procedure for management of acute (13 with type A, 11 with type B) and chronic 2012 by The Society of Thoracic Surgeons /$36.00 Published by Elsevier Inc doi: /j.athoracsur

2 ADULT CARDIAC 96 HOFFERBERTH ET AL Ann Thorac Surg BARE-METAL STENTS FOR AORTIC DISSECTION 2012;93: (7 with type B) aortic dissection at our tertiary referral university hospital. Preoperative patient characteristics are detailed in Table 1. Data Collection and Follow-Up Patient medical records were retrospectively reviewed for baseline characteristics, preoperative comorbidities, details of operative strategy, intraoperative events, and postoperative course. The clinical circumstances and rationale for treatment were obtained from operative reports. Endovascular Prosthesis and Procedure The STABLE procedure involved endograft closure of the primary entry tear and bare-metal Z stenting of the true lumen distally. Patients with type A dissection underwent open surgical intervention as indicated plus adjunctive retrograde proximal endograft deployment with bare-metal Z stents when the dissection extended beyond the resected aorta. The endograft length ranged from 120 to 150 mm. The extent of bare-metal Z stenting was determined by the distal extension of the dissection and any branch vessel or true lumen compromise. The first stage aimed to prevent malperfusion and rupture and was conducted under general anesthesia with surgical femoral arteriotomy. Baseline computed tomography and echocardiography was undertaken within 1 week to assess the extent of false lumen thrombosis and detect any reentry tears. False lumen thrombosis was defined as absence of enhancement of the false lumen with intravenous contrast. If reintervention was required, appropriate endovascular Table 1. Baseline Characteristics of 31 Study Patients Characteristics a Type A (n 13) Type B (n 18) Age, years Male sex 10 (76.9) 12 (66.7) Marfan syndrome 0 1 (5.5) Family history of aortic dissection 0 1 (5.5) Hypertension 9 (69.2) 14 (77.8) Hypercholesterolemia 2 (15.3) 5 (27.8) Bicuspid aortic valve 1 (7.6) 1 (7.6) Diabetes mellitus 1 (7.6) 2 (11.1) Active smoking 3 (23.1) 6 (33.3) Previous Cerebrovascular accident 0 2 (11.1) Aortic dissection 0 2 (11.1) Abdominal aortic aneurysm 0 1 (5.5) Cardiovascular operation 1 (7.6) 4 (22.2) Valve replacement Aortic valve 0 1 (5.5) Mitral valve 1 0 Coronary artery bypass grafting 0 1 (5.5) Type A aortic dissection repair 0 2 (11.1) a Continuous data are presented as mean standard deviation; categoric data as number (%). techniques were used through percutaneous access. If necessary, secondary entry tears were sealed in a secondstage procedure using a variety of endovascular techniques, including covered or bare-metal stents in branch vessels, coil embolization, aortic endografts, or Z stents. The Zenith Dissection Thoracic Endovascular stent (TXD Systems, William Cook Europe, Bjaeverskov, Denmark) Z stent system consists of a 1-piece cylindrical device constructed from self-expanding stainless steel Z stent segments sewn together with polyester sutures in multiple lengths from 70 to 130 mm (4, 6, or 8 stent segments) and preloaded in a 16F introducer sheath. It has an unconstrained diameter of 46 mm [15, 16]. The stent was used as a distal component in combination with the Zenith TX2 Thoracic TAA Endovascular Graft (William Cook Europe) and assists dissection remodelling by supporting delaminated aortic segments. The Z stent has a reduced radial force compared with standard endografts. The aim is to oppose the intima and media without producing aortic dilatation. Assessment of Aortic Remodelling Aortic remodelling was assessed with serial computed tomography angiography (CTA) at baseline, 1 year, and at the most recent follow-up (Table 2). The most recent follow-up CTA was assessed for false lumen perfusion and categorized by whether it affected the thoracic aorta, abdominal aorta, or both. Subsequently, asymptomatic patients with stable aortic diameters and significant true lumen expansion were managed conservatively regardless of ongoing false lumen perfusion. Statistical Analysis Data were analyzed with SPSS 17.0 software (SPSS Inc, Chicago, IL). Continuous variables were analyzed using the two-tailed Student t test. Time-to-event curves were calculated with the Kaplan-Meier method and compared by log-rank test. Significance level was set at p Results Procedural (30-Day) Outcomes Procedural characteristics, including device details and indications for the STABLE procedure are presented in Table 3. Procedural outcomes, including hospital morbidity and death are detailed in Table 4. Primary technical success, defined as device deployment in the absence of surgical conversion or death, graft limb obstruction, or type I or III endoleak [13], was achieved in 30 of 31 patients (97%). The mean length of stay was days in the intensive care unit and days in the hospital. There was one operative death, defined as death within 30 days of the procedure or during the same hospital admission (Table 4) [13]. The patient was a 78-year-old man with a known thoracic aortic aneurysm and previous aortic valve replacement who was transferred to our institution with multiorgan failure secondary to acute type B aortic dissection of the thoracic aneurysm. After

3 Ann Thorac Surg HOFFERBERTH ET AL 2012;93: BARE-METAL STENTS FOR AORTIC DISSECTION Table 2. Dimensional Changes of the Thoracic and Abdominal Aorta With Staged Total Aortic and Branch Vessel Endovascular Reconstruction Variable a Baseline 1 Year p Value Most Recent Follow-Up 97 p Value (vs Baseline) ADULT CARDIAC Thoracic aorta (carina) Acute (n 24) Max aortic diameter, mm True lumen index Chronic (n 7) Max aortic diameter, mm True lumen index Abdominal aorta (renal arteries) Acute (n 24) Max aortic diameter, mm True lumen index Chronic (n 7) Max aortic diameter, mm True lumen index a Data are presented in mm standard deviation. coverage of the primary entry tear with a proximal stent graft, a bare-metal stent was deployed; however, this became lodged in the distal aorta necessitating open surgical conversion. The patient died of respiratory failure 24 hours later. Four patients (12.9%) required transient hemofiltration after intervention. Two patients (6.4%) with type B dissection presented in acute renal failure, and both received hemofiltration before the intervention. None required ongoing treatment. A clinically silent myocardial infarction occurred postprocedure in 1 patient (3.2%) with a type A dissection (Table 4). Follow-Up Outcomes Clinical follow-up was completed in all 31 patients. Mean follow-up was 57.3 months (range, 5 to 100 months). Overall survival probability was 60.0% at 100 months, with an aortic-specific survival probability of 93% at 100 months (Fig 1). Late deaths were defined as deaths occurring after 30 days [13]. One death was aortic-related, and 6 patients died of unrelated conditions, including myocardial infarction in 2, disseminated carcinoma in 2, and complications secondary to a fractured femur in 1. Another died 24 hours after pacemaker insertion for complete heart block. At autopsy the aorta was intact. The aortic-related death was a 71-year-old woman with chronic type B dissection causing visceral malperfusion. Her medical history included surgical type A dissection repair. She underwent infrarenal stent graft placement and bare-metal stenting of the upper abdominal aorta. A residual reentry tear in the left renal artery remained because stent deployment was not deemed technically possible. She was discharged after 8 days in the hospital. Six weeks later she underwent emergency reintervention (stent graft extension and 1 Z stent deployed in the descending thoracic aorta) for an acute increase in the in maximal aortic diameter from 42 to 50 mm. False lumen perfusion persisted despite several embolization procedures. The patient died suddenly 4 months later, and autopsy confirmed aortic rupture. The one late adverse event involved a 58-year-old man. A type A dissection developed 7 years after the STABLE procedure for acute type B dissection and 4 years after coronary artery bypass grafting. The entry tear was identified just superior to the sinotubular junction at operation. He underwent successful surgical repair. Four patients (1 type A, 3 type B, 13%) required reintervention during follow-up for symptoms related to stent graft implantation. One had pain and pulse deficit in the left arm from proximal stent graft migration causing left subclavian artery dissection. A stent graft extension covering the left subclavian artery was deployed uneventfully. One patient presented with fever and hemoptysis secondary to proximal endograft infection causing an aortobronchial fistula 5 weeks postprocedure. Extraanatomic reconstruction with an axillofemoral bypass was performed. The patient then underwent deep hypothermic circulatory arrest through a left thoracotomy to excise the infected aortic aneurysm and oversew the distal descending thoracic aorta. The tracheal component was successfully treated by interposition of a pericardial fat pad between the esophagus and trachea. Another patient had back pain from a type I endoleak, which was embolized with coils. This failed to abolish the endoleak but resulted in immediate amelioration of symptoms. The endoleak was subsequently treated definitively with a further overlapping endograft deployed proximally. A retroperitoneal hematoma developed in 1 patient (3.2%) in the right hemipelvis extending into the inguinal region 1 week after management for acute type B dissection, which included covered stent deployment in the right common iliac artery. Follow-up computed tomog-

4 ADULT CARDIAC 98 HOFFERBERTH ET AL Ann Thorac Surg BARE-METAL STENTS FOR AORTIC DISSECTION 2012;93: Table 3. Procedural Characteristics Variable No. (%) or Median (range) Stent graft devices Cook Zenith TX2 a 29 (93.6) Luminexx Vascular stent b 1 (3.2) Fluency plus Vascular Stent Graft b 1 (3.2) Aortic stent type Cook Zenith Dissection Stent (Z stent) a 31 (100) Indications for STABLE Malperfusion 21 (67.7) Visceral (celiac, mesenteric, renal) 10 (47.6) Iliofemoral 9 (42.6) Visceral and iliofemoral 2 (9.8) Correct true lumen collapse 10 (32.3) Procedural details Average time to intervention, days Acute 2.5 (1 12) Chronic 43.5 ( ) Devices deployed, No. 2.9 (1 5) Coverage left subclavian artery 2 (6.4) Partial coverage 4 (12.9) No coverage 25 (80.7) Supraaortic branch vessel involvement 6 (46) (type A) Adjunctive procedures Distal stent graft extension 6 (19.3) Bare metal stenting 5 (16.1) Renal artery 3 (9.7) Mesenteric artery 1 (3.2) Iliofemoral vasculature 1 (3.2) Length of aortic coverage Suprarenal 10 (32.2) Infrarenal 21 (67.8) a William Cook Europe, Bjaeverskov, Denmark. b C.R. Bard, Murray Hill, New Jersey. STABLE Staged Total Aortic and Branch vessel Endovascular reconstruction. patient (3%) displayed false lumen perfusion of the thoracic aorta only, requiring no further reintervention, and 11 (35%) exhibited persistent false lumen perfusion within the abdominal aorta only. Seven patients (23%) demonstrated complete false lumen thrombosis at the most recent radiologic follow-up but had no long-term device-related complications. Comment For the 18 patients with type B aortic dissection, rates of procedural success (97%), stroke (0%), permanent paraplegia/paresis (0%), and in-hospital mortality (3%) in this series compared favorably with reported outcomes of established endovascular techniques [14, 17, 18]. In a meta-analysis [14] of 39 series reporting results of stent grafting of the proximal reentry tear for all type B dissection, a 30-day mortality of 9.8% was reported. Similarly, the International Registry for Aortic Dissection reported 11% mortality for acute type B dissection [19]. Large studies have reported 2% to 5% stroke, 1% to 5% paraplegia, and 2% retrograde ascending dissection within 30 days [14, 20]. The 16% (n 3) device-related reintervention rate in these type B patients is similar to the 12% reported using established endovascular therapy [14], despite our series having a mean follow-up extending 38 months longer. These results suggest STABLE does not increase morbidity acutely and does not increase complication or reintervention rates. The late aortic-related mortality rate of 3% (n 1) is similar to other published series [14, 18, 19], even with our substantially longer follow-up. The use of stent grafts in type A dissections has been described in hybrid open surgical techniques to address distal aortic complications [21 23]. These studies have reported in-hospital stroke rates up to 9% [22] and 6% to 14% mortality [21 23]. Table 4. In-Hospital and 30-Day Morbidity and Mortality Variable No. (%) or Mean SD raphy 1 month later demonstrated interval resolution of the hematoma. Freedom from reintervention was 90% at 12 months, 90% at 24 months, and 63% at 100 months after the STABLE procedure (Fig 2). Follow-Up Analysis of Aortic Remodelling Table 2 summarizes morphologic evolution and evidence of aortic remodelling over time. Mean radiologic follow-up of surviving patients was 32 months (range, 5 to 100 months). During follow-up, 27 patients (87%) underwent at least one CTA. Three did not return for scheduled follow-up; however, detailed clinical follow-up was collected. The extent of residual false lumen perfusion was assessed from the most recent follow-up CTA. Persistent false lumen perfusion in the thoracic and abdominal aorta was documented in 8 patients (26%), including 1 patient who died of aortic-related complications. One Intraprocedural results 30 (97.0) Deaths 0 Complications 1 (3.2) Morbidity Stroke 0 Ischemia a 0 Acute renal failure 4 (12.9) Permanent dialysis 0 Access vessel repair 1 (3.2) Myocardial infarction 1 (3.2) Length of stay, days Intensive care unit Hospital Mortality (30-day in-hospital) 1 (3.2) a Includes spinal cord ischemia, transient spinal cord ischemia, and limb ischemia. SD standard deviation.

5 Ann Thorac Surg HOFFERBERTH ET AL 2012;93: BARE-METAL STENTS FOR AORTIC DISSECTION Fig 1. Overall survival (dotted line, 60%) and aortic-specific survival (solid line, 93%) are shown to 100 months after the staged thoracoabdominal and branch vessel endoluminal repair. 99 ADULT CARDIAC The STABLE procedure is a safe and potentially highly effective ancillary technique in the emergency surgical setting with no 30-day deaths, a minimal device-related reintervention rate of 7% (n 1), and excellent long-term clinical outcomes (no aortic-related deaths). Midterm results suggest fewer distal aortic complications. Our evolving treatment paradigm has been that management of the distal aorta should be identical for type A and type B dissection. This reflects the idea that the disease process affects the whole aorta and its branches and minimizes our current inability to predict which patients will develop late complications. The major factors predicting long-term outcomes of aortic dissection are aortic diameter [4, 24] and false lumen patency [9, 20, 25, 26]. Stent grafting has been shown to reduce aneurysmal degeneration and to increase true lumen index in the thoracic aorta [27], but late expansion of the thoracoabdominal aorta has been reported [25]. In our series, STABLE prevented late aneurysmal degeneration and significantly increased the true lumen Fig 2. Freedom from reintervention is 63% at 100 months after the staged thoracoabdominal and branch vessel endoluminal repair.

6 ADULT CARDIAC 100 HOFFERBERTH ET AL Ann Thorac Surg BARE-METAL STENTS FOR AORTIC DISSECTION 2012;93: compounds the risks of multiple procedures, cumulative radiation dose, and contrast exposure. Our treatment paradigm was driven primarily by the clinical status of the patient and secondarily by the aortic dimensions at follow-up. We therefore frequently managed residual false lumen perfusion conservatively in stable patients. Persistent false lumen perfusion was evident in the 74% of patients with radiologic follow-up in our series, yet was not associated with increasing aortic diameter or worsening true lumen index. Nonetheless, it is noteworthy that the group with persistent false lumen perfusion included 4 patients with device-related complications and the solitary aortic-related death. Persistent false lumen perfusion may be a marker of increased risk in affected patients, reflecting a more recalcitrant form of the disease. Our impression is that a balance can be struck by careful radiologic follow-up assessing for changing aortic dimensions to predict impending complications. This allows tolerance of residual false lumen perfusion in patients with stable aortic dimensions, whilst permitting timely intervention where necessary. In practice we found that bare-metal stenting did not compromise vessels perfused from the false lumen. Fig 3. The staged thoracoabdominal and branch vessel endoluminal repair technique adjunctive to surgical intervention for type A aortic dissection. (A) Computed tomography angiography (i to iv) and angiography (v and vi) demonstrate intramural hematoma with dissection flap in the descending aorta perfused by a reentry tear at the left renal artery. The celiac axis was perfused from the false lumen (iv). (B) A dissection stent was placed to cover the intimal tear, reducing false lumen perfusion (i, ii). index of the thoracic and abdominal aorta, with longer follow-up data (Figs 3 and 4). Early studies established that false lumen thrombosis should be a primary therapeutic goal [7, 20, 25, 26], with continued false lumen patency found to predict late death [26]. Complete false lumen thrombosis may not be achievable in some patients, and pursuing this goal Fig 4. (A, i; B, i, ii) Computed tomography angiography 4 years after staged thoracoabdominal and branch vessel endoluminal repair demonstrates complete remodelling of the descending thoracic aorta. There was residual false lumen perfusion, but improved true lumen index without dilatation. (B, iii) Celiac axis perfusion was not compromised.

7 Ann Thorac Surg HOFFERBERTH ET AL 2012;93: BARE-METAL STENTS FOR AORTIC DISSECTION There was no stroke or paraplegia, which may be due to using shorter stent grafts with less compromise of anterior spinal vessels. This corroborates previous reports that adjunctive bare-metal stenting successfully induces aortic remodelling without compromising branch vessel perfusion [15, 16, 26, 28, 29]. Nienaber and colleagues [29] used adjunctive or staged implantation of bare-metal stents in 12 patients with complicated type B dissection, and likewise reported favorable results, albeit with shorter follow-up. In 2008 Melissano and colleagues [28] reported early outcomes using the same Zenith Dissection stent as used in our cohort in 11 selected patients with chronic type B dissection. They reported a clinical success rate of 91% at 12 months, with no death, stroke, or paraplegia [28]. The encouraging outcomes we report are limited by the retrospective nature of this series and the small number of patients. Nevertheless, our periprocedural and follow-up outcomes compare favorably with established techniques. The complete clinical data and significant length of follow-up in this series adds valuable information to previous reports using a similar technique because we were able to assess the efficacy of this approach in preventing late complications in the distal aorta. In summary, STABLE is a feasible ancillary technique to reduce distal true lumen collapse, enhance aortic remodelling, and prevent late aneurysm formation in type A and type B aortic dissection. It appears to address late distal aortic complications not prevented by existing techniques. Controlled trials with longer follow-up are required to introduce STABLE into the broader clinical arena. We thank Prof Raymond C. Boston for his statistical support. References 1. MacKenzie KS, LeGuillan MP, Steinmetz OK, Montreuil B. Management trends and early mortality rates for acute type B aortic dissection: a 10-year single-institution experience. Ann Vasc Surg 2004;18: Miller DC, Stinson EB, Oyer PE, et al. Operative treatment of aortic dissections. Experience with 125 patients over a sixteen-year period. J Thorac Cardiovasc Surg 1979;78: Umana JP, Lai DT, Mitchell RS, et al. Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections? J Thorac Cardiovasc Surg 2002;124: 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 Winnerkvist A, Lockowandt U, Rasmussen E, Radegran K. A prospective study of medically treated acute type B aortic dissection. Eur J Vasc Endovasc Surg 2006;32: Marui A, Mochizuki T, Mitsui N, Koyama T, Kimura F, Horibe M. Toward the best treatment for uncomplicated patients with type B acute aortic dissection: a consideration 101 for sound surgical indication. Circulation 1999;100(19 Suppl): II Halstead JC, Meier M, Etz C, et al. The fate of the distal aorta after repair of acute type A aortic dissection. J Thorac Cardiovasc Surg 2007;133: Kirsch M, Soustelle C, Houel R, Hillion ML, Loisance D. Risk factor analysis for proximal and distal reoperations after surgery for acute type A aortic dissection. J Thorac Cardiovasc Surg 2002;123: Ergin MA, Phillips RA, Galla JD, et al. Significance of distal false lumen after type A dissection repair. Ann Thorac Surg 1994;57:820 4; discussion Dake MD, Kato N, Mitchell RS, et al. Endovascular stentgraft placement for the treatment of acute aortic dissection. N Engl J Med 1999;340: Cambria RP, Brewster DC, Lauterbach SR, et al. Evolving experience with thoracic aortic stent graft repair. J Vasc Surg 2002;35: Nienaber CA, Fattori R, Lund G, et al. Nonsurgical reconstruction of thoracic aortic dissection by stent-graft placement. N Engl J Med 1999;340: Chaikof EL, Blankensteijn JD, Harris PL, et al. Reporting standards for endovascular aortic aneurysm repair. J Vasc Surg 2002;35: Eggebrecht H, Nienaber CA, Neuhauser M, et al. Endovascular stent-graft placement in aortic dissection: a metaanalysis. Eur Heart J 2006;27: Mossop P, Nixon I, Oakes J, Devine TJ, McLachlan CS. Immediate total aortic true lumen expansion in type A and B acute aortic dissection after endovascular aortic endografting and GZSD bare stenting. J Thorac Cardiovasc Surg 2007;134: Mossop PJ, McLachlan CS, Amukotuwa SA, Nixon IK. Staged endovascular treatment for complicated type B aortic dissection. Nat Clin Pract Cardiovasc Med 2005;2:316 21; quiz Chaikof EL, Mutrie C, Kasirajan K, et al. Endovascular repair for diverse pathologies of the thoracic aorta: an initial decade of experience. J Am Coll Surg 2009;208: Szeto WY, McGarvey M, Pochettino A, et al. Results of a new surgical paradigm: endovascular repair for acute complicated type B aortic dissection. Ann Thorac Surg 2008;86: Tsai TT, Evangelista A, Nienaber CA, et al. Long-term survival in patients presenting with type A acute aortic dissection: insights from the International Registry of Acute Aortic Dissection (IRAD). Circulation 2006;114(1 Suppl): I Rodriguez JA, Olsen DM, Lucas L, Wheatley G, Ramaiah V, Diethrich EB. Aortic remodeling after endografting of thoracoabdominal aortic dissection. J Vasc Surg 2008;47: 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: Jakob H, Tsagakis K, Tossios P, et al. Combining classic surgery with descending stent grafting for acute DeBakey type I dissection. Ann Thorac Surg 2008;86: 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: Davies RR, Gallo A, Coady MA, et al. Novel measurement of relative aortic size predicts rupture of thoracic aortic aneurysms. Ann Thorac Surg 2006;81: Schoder M, Czerny M, Cejna M, et al. Endovascular repair of acute type B aortic dissection: long-term follow-up of true ADULT CARDIAC

8 ADULT CARDIAC 102 HOFFERBERTH ET AL Ann Thorac Surg BARE-METAL STENTS FOR AORTIC DISSECTION 2012;93: and false lumen diameter changes. Ann Thorac Surg 2007;83: Bernard Y, Zimmermann H, Chocron S, et al. False lumen patency as a predictor of late outcome in aortic dissection. Am J Cardiol 2001;87: Nathanson DR, Rodriguez-Lopez JA, Ramaiah VG, et al. Endoluminal stent-graft stabilization for thoracic aortic dissection. J Endovasc Ther 2005;12: Melissano G, Bertoglio L, Kahlberg A, et al. Evaluation of a new disease-specific endovascular device for type B aortic dissection. J Thorac Cardiovasc Surg 2008;136: Nienaber CA, Kische S, Zeller T, et al. Provisional extension to induce complete attachment after stent-graft placement in type B aortic dissection: the PETTICOAT concept. J Endovasc Ther 2006;13: INVITED COMMENTARY Endovascular repair is well described in the literature as primary treatment for acute type B dissection or as an adjunct to surgically repaired acute type A dissection. The goal of therapy is to maximize aortic true lumen diameter, enhance the opportunity for false lumen thrombosis, prevent late aortic dilatation, reduce the need for future open or endovascular surgical repair, and improve long-term patient survival. For the subgroup of patients presenting with acute type B dissection complicated by aortic rupture or malperfusion, there may be an improvement in perioperative mortality rates and 1-year survival when endovascular repair is compared with traditional open intervention [1]. However, the support for using stent graft therapy for any other type of aortic dissection is less convincing. The data presented by Hofferberth and colleagues [2] do not advance the case for endovascular intervention in uncomplicated aortic dissections. Rather, these results generate as many questions as answers about the appropriate approach to this highly lethal disease. It suggests that perhaps our treatment algorithms are becoming too complicated given the excellent outcomes we currently obtain using more established surgical and medical therapy. The staged thoracoabdominal and branch vessel endoluminal procedure (STABLE) is a tour de force of endovascular aortic therapy. This technique eliminates the entry tear (with a covered stent graft for type B or with surgical reconstruction for type A) and increases the true luminal diameter in the distal aorta through a combination of stent grafting and bare-metal stenting of the visceral and infrarenal segments. The authors are to be commended for completing this extremely complex procedure 97% of the time with minimal procedurally related mortality (3.2%) and impressively low rates of neurologic complications. However, although the staged thoracoabdominal and branch vessel endoluminal repair clearly improved true lumen perfusion and diameter, it failed to adequately suppress false lumen patency. Perfusion of the abdominal or thoracic aortic false lumen was still present in 74% of the patients who had this extensive procedure. At the 1-year follow-up, aortic diameters in the chest were not reduced, and those in the abdomen continued to expand. Data on patients having complete imaging beyond this time period were limited. In addition, the goal of minimizing additional procedures was not achieved. Adjunctive procedures were required in 40% of patients before discharge. An additional 15% required branch vessel intervention, and 5 patients (17%) required a late aortic procedure for stentrelated complications, including aortic rupture. Most important, a patent false lumen was present in all of the patients who needed aortic reintervention and in the one aortic-related death. In the current era, patients presenting with acute aortic dissection can expect excellent short-term and long-term survival using established methods of treatment. The operative mortality rate for acute type A dissection repair continues to decline and is associated with a 10-year survival of 88% [3]. Encouraging results can also be achieved for patients with uncomplicated type B dissections. A recent trial randomized 140 patients to optimal medical therapy alone or to optimal medical therapy and adjunctive stent grafting [4]. There was no significant difference between the groups in 2-year cumulative survival (95% without stenting, 89% with), need for late endovascular or open repair, or aortic-related death. Surgical innovation using evolving technology is the cornerstone of cardiovascular surgery. However, before we adopt complex treatment algorithms, such as staged thoracoabdominal and branch vessel endoluminal repair, into our surgical armamentarium for aortic dissections, we must first rigorously analyze the results to ensure our patients the best opportunity to survive this lethal disease. Leonard N. Girardi, MD Department of Cardiothoracic Surgery Weill Cornell Medical College 525 E 68th St, M-424 New York, NY lngirard@med.cornell.edu References 1. Szeto WY, McGarvey M, Pochettino A, et al. Results of a new surgical paradigm: endovascular repair for acute complicated type B aortic dissection. Ann Thorac Surg 2008;86: Hofferberth SC, Foley PT, Newcomb AE, et al. Combined proximal endografting with distal bare-metal stenting for management of aortic dissection. Ann Thorac Surg 2012;93: Chiappini B, Schepens M, Tan E, et al. Early and late outcomes of acute type A aortic dissection: analysis of risk factors in 487 consecutive patients. Eur Heart J 2005;26: Nienaber CA, Rousseau H, Eggerbrecht H, et al. Randomized comparison of strategies for type B aortic dissection: The Investigation of stent-grafts in aortic dissection (INSTEAD) trial. Circulation 2009;120; by The Society of Thoracic Surgeons /$36.00 Published by Elsevier Inc doi: /j.athoracsur