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Ann Thorac Surg 2007;84:1955-1964. doi:10.1016/j.athoracsur.2007.07.017
© 2007 The Society of Thoracic Surgeons
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Arnar Geirsson
Joseph E. Bavaria
Y. Joseph Woo
Wilson Y. Szeto
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Original Articles: Cardiovascular

Fate of the Residual Distal and Proximal Aorta After Acute Type A Dissection Repair Using a Contemporary Surgical Reconstruction Algorithm

Arnar Geirsson, MDa, Joseph E. Bavaria, MDa, Daniel Swarr, BSa, Martin G. Keane, MDb, Y. Joseph Woo, MDa, Wilson Y. Szeto, MDa, Alberto Pochettino, MDa,*

a Division of Cardiothoracic Surgery, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania
b Cardiovascular Medicine, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania

Accepted for publication July 9, 2007.

* Address correspondence to Dr Pochettino, Division of Cardiothoracic Surgery, Hospital of the University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104-4283 (Email: alberto.pochettino{at}uphs.upenn.edu).

Presented at the Forty-third Annual Meeting of The Society of Thoracic Surgeons, San Diego, CA, Jan 29–31, 2007.


Dr Bavaria discloses that he has a financial relationship with CarboMedics Inc, CryoLife Inc, Medtronic USA Inc, St. Jude Medical Inc, and Vascutek USA Inc.

 

   Abstract
Top
 Abstract
Introduction
 Patients and Methods
 Results
 Comment
 Discussion
 Appendix 1
 Appendix 2
 Acknowledgments
 References
 
Background: In this study, we evaluated the long-term results of our contemporary, standardized surgical management algorithm for repair of acute type A aortic dissections. Prior reports have analyzed heterogeneous techniques and populations.

Methods: From 1993 to 2004, 221 consecutive patients underwent repair of acute type A aortic dissection at our aortic center. Hemiarch repair was performed in 97.7% (216 of 221), and total arch in 2.3% (5 of 221). Of these, 72.9% (161 of 221) underwent aortic valve resuspension, and 27.1% (60 of 221) had aortic root replacement.

Results: In-hospital mortality for a primary operation was 12.7% (28 of 221). Actuarial survival was 79.2% at 1 year, 62.8% at 5 years, and 46.3% at 10 years. Significant risk factors for decreased survival included prior stroke, cerebral malperfusion, and length of cardiopulmonary bypass. Freedom from proximal reoperation after aortic valve resuspension was 94.6% at 5 years and 76.8% at 10 years, with cardiac malperfusion as the main risk factor. Freedom from distal reoperation was 87.6% at 5 years and 76.4% at 10 years, with Marfan syndrome, age, and extent of dissection as significant risk factors for reoperation. In-hospital mortality was 18.2% (2 of 11) after proximal reoperation and 31.2% (5 of 16) after distal reoperation.

Conclusions: We report improved long-term durability of our proximal root repair, with cardiac malperfusion as a significant risk factor. Marfan disease, younger age, and DeBakey type I dissection are risk factors for distal reoperation. To further improve long-term outcome, means to prevent progression of distal aortic disease need to be developed.

Acute type A dissection remains one of the most challenging diseases the cardiothoracic surgeon faces. In 1972, the estimated mortality without surgical treatment for acute aortic dissection was 1% to 2% per hour, with less than 10% surviving 3 days. Patients died from aortic rupture, severe aortic insufficiency, or malperfusion syndrome [1]. In a recent population-based series, the incidence of acute aortic dissection (both Stanford type A and B) was 3.5 per 100,000 person-years, with an overall 5-year survival rate of 32% and a median survival of 3 days [2]. In-hospital mortality after surgical treatment of acute type A aortic dissection is 14% to 32.5% in published series [3–6]. Without surgical treatment, the in-hospital mortality for acute type A aortic dissection is 58% [6]. Expeditious surgical treatment is therefore essential in successful management of patients with acute type A aortic dissection.

When the Thoracic Aortic Disease Center at the University of Pennsylvania Health System was established in 1993, our group initiated a uniform approach in the treatment of type A aortic dissection [7]. Our surgical protocol addresses replacement of the ascending aorta, repair or replacement of the aortic sinus segment to treat or prevent coronary malperfusion, resuspension or replacement of the aortic valve (AV), and replacement of most of the aortic arch to prevent malperfusion of the arch vessels and establish normal true lumen flow down the proximal descending thoracic aorta.

Open arch reconstruction is performed with uniform use of hypothermic circulatory arrest and retrograde cerebral perfusion. Antegrade cerebral perfusion is used selectively when circulatory arrest time is expected to be excessive, mainly for total arch replacement. We believe this approach provides optimal cerebral protection and allows accurate identification and resection of the primary tear site along with ease of arch reconstruction. Status of brain function and arch vessel perfusion are closely monitored by electroencephalography, when available, and bilateral carotid duplex ultrasound interrogation.

Short-term benefits of our standardized approach have been previously described [8]. In this report we wanted to define long-term outcomes of our strategy, focusing primarily on survival and need for proximal or distal reoperations. Prior reports of long-term outcomes include mostly heterogenous techniques and populations.


   Patients and Methods
Top
 Abstract
 Introduction
 Patients and Methods
Results
 Comment
 Discussion
 Appendix 1
 Appendix 2
 Acknowledgments
 References
 
Patients
This study was approved by the Investigational Review Board of the University of Pennsylvania (#804788), which waived the need for individual patient consent for the study. Patients were included if they had undergone surgical repair for acute type A aortic dissection in the years 1993 to 2004 performed by surgeons of the Thoracic Aortic Disease Center at the University of Pennsylvania who followed a uniform reconstruction algorithm. Patients had to have an open arch reconstruction with the use of hypothermic circulatory arrest (HCA) and retrograde cerebral perfusion (RCP) with or without selective antegrade perfusion. Furthermore, proximal reconstruction had to consist of root replacement or sinus repair with Teflon (DuPont, Wilmington, DE) felt neomedia. A complete medical record had to be available.

During the time period, 244 consecutive patients underwent repair for acute type A aortic dissection at the University of Pennsylvania, of whom 23 were excluded because HCA/RCP and open arch reconstruction were not used (n = 10) and/or a different proximal surgical technique was used (n = 18). These cases occurred in decreasing frequency during the first 5 years of the study because surgeons outside the Thoracic Aortic Program eventually stopped repairing acute type A dissections. The analysis included 221 cases.

Demographics and Clinical Presentation
The demographics and clinical presentation for the 221 patients are summarized in Table 1. Their mean age was 61.6 years (range, 21 to 89 years). Malperfusion syndromes were evident in 59 (26.7%), with myocardial ischemia noted in 7.2% of cases and cerebral malperfusion with evidence of preoperative neurological event in 7.2%. Preoperative aortic insufficiency (AI) evaluated by transesophageal echocardiogram (TEE) was graded 0 in 21.7% of patients, 1 to 2+ in 51.7%, and 3 to 4+ in 25.6%.


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  		Table 1 Patient Characteristics
 
Operative Methods
Our standardized type A dissection algorithm was as follows:
• As soon as notification of a suspected type A aortic dissection was received, rapid transfer to the operating room was arranged. We did not delay operative intervention by obtaining coronary angiography. On occasion, patients had cardiac catheterization at outside institutions before notification.
• A pulmonary artery catheter was placed before the patient was prepared and draped if the patient was hemodynamically stable or at any time during the procedure as feasible.
• Intraoperative TEE was obtained in all patients to confirm the diagnosis, look for any concomitant cardiac abnormalities, plan the proximal repair, and check the effectiveness of the root repair at the completion of the operation. EEG monitoring was obtained whenever possible and was used in 120 of 221 (54.1%) cases.
• Bilateral carotid artery flow was interrogated by duplex ultrasound in all patients at standardized times: induction of anesthesia (baseline), establishment of cardiopulmonary bypass (CPB), placement of the ascending aortic cross-clamp, and at resumption of antegrade CPB after completion of arch reconstruction. If carotid artery malperfusion was detected by duplex ultrasound, often correlated by EEG asymmetry if available, surgical maneuvers were initiated to reverse them: alteration in arterial cannulation, ascending/arch flap fenestration, or revision of the arch reconstruction.
• Arterial cannulation was by femoral artery in 196 of 221 (88.7%) cases, followed by the ascending aorta or aortic arch in 13 (5.9%) and the subclavian or axillary artery in 12 (5.4%). Venous cannulation was achieved with a standard right atrial double-stage cannula and a small right-angle single-stage superior vena cava cannula, unless concomitant cardiac abnormalities dictated the use of bicaval cannulation.
• Core cooling was begun as soon as satisfactory CPB was established and after the left ventricle was vented through the right superior pulmonary vein. Patients who had EEG monitoring were cooled for 3 minutes beyond EEG silence. When EEG monitoring was not available, patients were cooled for 50 minutes or until the nasopharyngeal temperature reached 12°C, whichever occurred first [9].
• Pharmacologic adjuncts included methylprednisolone, magnesium, and lidocaine (to delay cardiac fibrillation).
• As soon as the heart fibrillated, a cross-clamp was placed across the distal ascending aorta, which was then transected at the level of the right pulmonary artery. Myocardial protection was achieved with a combination of intermittent antegrade and retrograde cold blood cardioplegia through the coronary ostia and the coronary sinus, respectively.
• AV resuspension was performed whenever feasible. Feasibility was defined by normal valve leaflets, normal sized sinuses, and intimal tear not extending within the sinuses proper. The aortic root repair consisted of Teflon felt neomedia placed within the dissected portions of the sinuses and a Dacron (DuPont) graft sewn to the mobilized sinotubular junction. When repair was not feasible, root replacement with a biologic or mechanical valved conduit was performed. Indications for root replacement are summarized in Table 1.
• As soon as adequate cooling was achieved, proximal reconstruction was stopped and focus was directed to the aortic arch. HCA was established along with RCP consisting of oxygenated blood at 10° to 12°C infused into the snared superior vena cava cannula at a jugular venous pressure of 20 to 25 mm Hg, usually at flows between 200 and 300 mL/min.
• The primary tear site, all of the ascending aorta, and most (rarely all) of the aortic arch tissue were excised. Residual dissected arch or proximal descending thoracic aortic tissue, or both, was reinforced with Teflon felt neomedia. When it was determined that arch reconstruction would require more than 40 to 50 minutes, selective antegrade cerebral perfusion was used early (within 5 to 10 minutes of HCA after mobilization of arch structures), either by the axillary cannulas or by a balloon-tipped cannula placed in the innominate and left common carotid arteries.
• The excised aortic arch was replaced with Dacron graft, which was always directly cannulated to resume antegrade CPB. Proximal aortic reconstruction was then completed during rewarming. An ascending graft or root replacement conduit-to-arch graft anastomosis completed the repair.

The mean ± SD cardiopulmonary bypass time was 238.8 ± 62.1 minutes, cross-clamp time was 169.3 ± 46.6 minutes, and hypothermic circulatory arrest with retrograde cerebral perfusion was 38.2 ± 14.5 minutes. Selective antegrade perfusion, used in the 3 patients with total arch replacement, averaged 43.3 ± 17.1 minutes.

Proximal repairs in the 221 patients included 161 (72.9%) with successful AV resuspension, with 52 (23.5%) requiring root replacement. One patient had valve-sparing root replacement; 4 underwent AV replacement within a nondissected or a repaired root; and 3 had prior well-functioning prosthetic AVs and therefore only had ascending graft replacement. Indications for root replacement are summarized in Table 1. Patients who underwent composite root replacement were more likely to have AI exceeding 2+ than those who underwent AV resuspension: 43.8% and 25.6%, respectively (p = 0.005). Six of 10 Marfan patients had composite root replacement and the other 4 underwent AV resuspension, with most of the diagnoses of Marfan syndrome made after repair (Ghent criteria).

Three of 22 patients with bicuspid AV underwent AV resuspension, and the other 19 had aortic root replacement. Hemiarch replacement was used in all but 3 patients who underwent total arch replacement.

Other associated procedures performed at the same setting included coronary artery bypass grafting (CABG) in 17 (7.7%), mostly for coronary malperfusion or when the right coronary artery could not be reimplanted within a root replacement. One patient (0.5%) had mitral valve repair, and 10 (4.5%) had ileofemoral revascularization.

We started using BioGlue surgical adhesive (CryoLife Inc, Kennesaw, GA) in February 1999, and for the entire series, it was used in 49.8% of cases. Of patients undergoing operation since February 1999, we used BioGlue in 67.5% of cases. We used a small amount of BioGlue in between the dissected layers to secure the Teflon felt neomedia as well as small amount externally for hemostasis.

Follow-Up
Mortality was assessed through medical records and the Social Security Death Index completed for October 30, 2006. Survival data were available for all but 1 patient. Survival follow-up was 904 patient-years, with mean follow-up of 49.1 months. The longest follow-up was 13.1 years. Clinical follow-up was obtained through medical records, telephone calls, and letters. Two patients were lost to clinical follow-up, with completed records in 219 of 221 patients (99%). Eleven patients had less than 1 year of follow-up. Total follow-up was 731 patient-years, with mean follow-up of 39.7 months.

Statistical Analysis
This was a retrospective observational study. Definitions are provided in Appendix 1. Variables are shown in Appendix 2 and were collected by retrospective review of patient hospital charts and office notes, by phone calls, and by using prospectively collected Society of Thoracic Surgeons (STS) data at the University of Pennsylvania. Continuous variables were expressed as the mean ± SD and were compared with an unpaired 2-tailed t test. Categoric variables, expressed as percentage, were analyzed with a {chi}2 test. Survival and freedom from reoperations were analyzed with the Kaplan-Meier actuarial method and compared with the log-rank test. Results at 1 year, 5 years, and 10 years are expressed as percentage ± SD. To analyze risk factors for long-term survival, proximal reoperations, and distal reoperations, univariate analysis was performed on patient demographics, presenting symptoms, intraoperative factors, and postoperative factors by comparing different subsets of patients. Significant or marginally significant (p ≥ 0.20) risk factors were then analyzed by Cox multivariate proportional hazard regression and expressed as a hazard ratio (HR) with the 95% confidence interval (CI).


   Results
Top
 Abstract
 Introduction
 Patients and Methods
 Results
Comment
 Discussion
 Appendix 1
 Appendix 2
 Acknowledgments
 References
 
Morbidity
Morbidity in the 216 patients was significant, with 59.3% experiencing some adverse event. Excluding the five intraoperative deaths, the reexploration rate for bleeding was 8.3% (18 of 216). Postoperative myocardial infarction occurred in 12 patients (5.6%), sepsis in 14 (6.5%), and sternal wound infection in 4 (1.9%). Cerebral complication included new postoperative strokes in 16 patients (7.4%), transient ischemic attack in 6 (2.8%), unresponsiveness for more than 24 hours in 15 (6.9%), and global temporary neurologic dysfunction in 70 (32.7%). Acute renal failure complicated postoperative care in 21 patients (9.7%), with 13 requiring dialysis. More than 24 hours on a ventilator was needed in 50 patients (23.1%), and 26 (12.0%) required tracheostomy. Multisystem organ failure (MSOF) occurred in 12 patients (5.6%).

Survival
The in-hospital mortality was 12.7%, and the 30-day mortality was 11.8%. The in-hospital mortality was 23.1% for root replacement and 8.1% for AV resuspension (p = 0.004). For the 28 patients who died in-hospital, the primary reason was cardiac failure in 7 (25%), exsanguination in 3 (10.7%), MSOF in 11 (39.8%), and neurologic events in 7 (25%). The actuarial survival for all patients was 79.2% ± 2.7% at 1 year, 62.8% ± 3.5% at 5 years, and 46.3% ± 5.1% at 10 years (Fig 1).


Figure 1
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  		Fig 1. Kaplan-Meier estimate of actuarial survival of patients after operative repair of acute type A aortic dissection.

 
No significant difference was found in long-term survival when AV resuspension and composite root replacement were compared (log-rank, 0.50; p = 0.478). In patients who underwent AV replacement and ascending graft replacement with retention of the sinus segment (Wheat), both 5-year and 10-year actuarial survival was 25.0% ± 21.6% (log-rank, 2.72; p = 0.099), with the single current survivor requiring proximal reoperation for prosthetic valve endocarditis. Actuarial survival of patients discharged from the hospital was 90.7% ± 2.1% at 1 year, 71.8% ± 3.6% at 5 years, and 53.0% ± 5.6% at 10 years.

Univariate predictors of decreased long-term survival included peripheral vascular disease (p = 0.026), prior stroke (p = 0.024), coronary artery disease (p = 0.020), hypotension at presentation (p = 0.024), preoperative arrest (p = 0.003), cerebral malperfusion (p = 0.001), and length of CPB (p = 0.036). Multivariate analysis was performed on these additional, marginally significant variables: prior CABG, chronic renal failure, age, sex, and type of proximal reoperation. Multivariate proportional hazard regression analysis revealed that prior stroke, cerebral malperfusion, and length of CPB were significant risk factors for decreased long-term survival (Table 2).


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  		Table 2 Multivariate Analysis of Risk Factors for Decreased Survival a
 
Dependent variables that on univariate analysis were associated with decreased survival included postoperative unresponsiveness exceeding 24 hours (p < 0.001), postoperative renal failure (p < 0.001), need for postoperative dialysis (p < 0.001), ventilatory requirement exceeding 24 hours (p < 0.001), MSOF (p < 0.001), acute limb ischemia (p = 0.047), and need for tracheostomy (p = 0.003).

Reoperations
Twenty-four reoperations were required: 8 patients required proximal reoperation only, 13 required distal reoperation only, and 3 needed both. One of the patients that required both underwent sequential operations: first, an AV replacement for endocarditis, and a year later, repair of 8.5 cm thoracoabdominal aortic aneurysm (TAAA). The other 2 patients had simultaneous operations through sternotomy: a redo ascending and hemiarch grafts for proximal and distal pseudoaneurysm, and aortic root replacement for severe AI and redo hemiarch for distal pseudoaneurysm. Freedom from any reoperation for all cases estimated by actuarial methods was 87.4% ± 3.2% at 5 years and 70.0% ± 7.4% at 10 years.

Proximal Reoperations
Indications for the 11 proximal reoperations (Table 3) included severe AI in 5 patients, pseudoaneurysm in 5, and endocarditis and graft infection in 3. Endocarditis developed in one of the separate AV replacement/valve grafts (Wheat) and in one patient with composite mechanical root replacement. No endocarditis developed in any of the patients who had AV resuspension, but one required reoperation for ascending graft infection.


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  		Table 3 Proximal Reoperations
 
Freedom from proximal reoperation for all patients, estimated by actuarial methods, was 95.1% ± 2.0% at 5 years and 77.8% ± 7.7% at 10 years. When only patients who underwent AV resuspension were analyzed, the freedom from proximal reoperation was 94.6% ± 2.3% at 5 years and 76.8% ± 9.2% at 10 years (Fig 2).


Figure 2
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  		Fig 2. Kaplan-Meier estimate of freedom from proximal reoperation in patients undergoing aortic valve resuspension.

 
Proximal reoperation has not been required in any of the Marfan patients (4 of 10) or bicuspid AV cases (3 of 22) that had AV resuspension. For Marfan patients, the follow-up was 8.78, 6.76, 6.23, and 4.79 years with respective AI of 2+, 4+, 0, and 0. For bicuspid AV patients, the follow-up was 12.26, 3.74, and 0.59 years with respective AI of 2+, 1+, and 0.

Significant univariate risk factors for proximal reoperation in patients who had AV resuspension were cardiac malperfusion (p = 0.007) and ileofemoral malperfusion (p = 0.05). Freedom from proximal reoperations in patients without cardiac malperfusion was 95.7% ± 2.1% at 5 years and 79.7% ± 9.3% at 10 years. In patients with cardiac malperfusion, freedom from proximal reoperations was 75.0% ± 21.6% at 5 years and 37.5% ± 28.7% at 10 years (log-rank, 9.91; p = 0.0016; Fig 3).


Figure 3
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  		Fig 3. Kaplan-Meier estimate of freedom of proximal reoperation of patient undergoing aortic valve resuspension with (dashed line) or without (solid line) cardiac malperfusion.

 
We performed Cox multivariate analysis on cardiac malperfusion, ileofemoral malperfusion, sex, age, and extent of dissection. It revealed that the only significant risk factor for proximal reoperation was cardiac malperfusion (Table 4). There was no association between use of BioGlue, grade of preoperative AI, or postrepair AI and the need for proximal reoperation.


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  		Table 4 Multivariate Analysis of Risk for Reoperation a
 
Distal Reoperations
There were 16 distal reoperations (Table 5). Indications included TAAA in 12 patients, pseudoaneurysm in 4, and graft infection in 1. Freedom from distal reoperation estimated by actuarial methods was 86.5% ± 3.6% at 5 years and 75.4% ± 9.5% at 10 years (Fig 4). None of the five total arch replacements have required reoperations.


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  		Table 5 Distal Reoperations
 

Figure 4
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  		Fig 4. Kaplan-Meier estimate of freedom from distal reoperation in all patients.

 
Univariate analysis revealed that risk factors for distal reoperation were younger age (p = 0.004), Marfan syndrome (p = 0.004), and DeBakey type I dissection (p = 0.044). By Cox multivariate analysis including sex and these variables, younger age and extent of dissection were significant risk factors (Table 4). Age younger than 45 years was associated with significant higher risk of distal reoperation when analyzed by Kaplan-Meier methods (log-rank, 6.33; p = 0.012; Fig 5). Freedom from distal reoperation for patients younger than 45 was 66.7% ± 13.4% at 5 years and 50.1% ± 17.6% at 10 years, whereas for age 45 and older, it was 89.5 ± 3.5% at 5 years and 87.5 ± 4.0% at 10 years. There was no association between use of BioGlue and the need for distal reoperation.


Figure 5
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  		Fig 5. Kaplan-Meier estimate of freedom from distal reoperation patients aged younger than 45 years (dashed line) compared with patients 45 years and older (solid line).

 
Survival After Reoperations
The in-hospital mortality after reoperation was significant. Two patients (18.2%) died after proximal reoperation. Patient 4 (Table 3) died of MSOF after aspiration. Patient 8 (Table 3) was an intravenous drug abuser with graft infection, proximal pseudoaneurysm, aortic–right atrial fistula, right ventricular failure, and liver failure who died intraoperatively after an attempted repair. Five patients (31.2%) died after distal reoperation. Patient 4 (Table 5) had Marfan syndrome and died of MSOF after repair of a TAAA complicated by bleeding. Patient 5 (Table 5) died of MSOF after repair of a TAAA complicated by cardiac arrest due to protamine reaction. Patient 6 (Table 5) died of MSOF after repair of TAAA. Patient 11 (Table 5) had Marfan syndrome and died of descending aortic rupture after total arch replacement for distal pseudoaneurysm and graft infection. Patient 13 (Table 5) presented with contained rupture of a 5.5 cm TAAA and underwent emergency operative repair but died few days later of MSOF.


   Comment
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
Discussion
 Appendix 1
 Appendix 2
 Acknowledgments
 References
 
Acute type A dissection remains one of the most challenging diseases facing cardiothoracic surgeons and is associated with high mortality and morbidity. Prevention of disease process progression in the residual dissected aorta is an important aspect of the patient’s long-term outcome. In an attempt to improve overall outcome in these complex patients, our Thoracic Aortic Surgery group established guidelines in the treatment of acute type A aortic dissection. We felt that no single therapeutic advance would significantly impact outcome, but we hoped that a standardized perioperative approach would lead to an improvement in overall results.

Our practice is immediate operative repair, regardless of the patient’s condition and the time of the day. We do not delay operative intervention with additional preoperative workup, including coronary and cerebral imaging. The patient is directly admitted to the operating room.

Our operative approach consists of replacing the entire ascending aorta, resuspension of the AV with repair or replacement of the sinus segment, and routine open replacement of the arch. This replacement is done under hypothermic circulatory arrest with retrograde cerebral perfusion. The false lumen is obliterated at the distal arch/proximal descending thoracic aorta, thus reestablishing normal flow in the descending thoracic true lumen. We use root replacement and total arch replacement selectively. Although this is a case series, the strength of the study is that the surgical techniques and the perfusion strategy are standardized, which results in a homogenous cohort.

Our hope was that our approach might result in improved freedom from proximal and distal reoperations and increased long-term survival. Our patients have characteristics similar to previous reports, including the International Registry of Acute Aortic Dissection database [6]. This study confirms that we substantially improved short-term survival, as measured by in-hospital mortality rate of 12.7%, compared with other reports. It is important to point out that all patients who arrived in the operating room with vital signs were included in our mortality analysis. Other series report an in-hospital mortality rate of 14% to 32.5% [3, 4, 6].

Complications after operative repair for acute type A dissection were significant. New postoperative strokes occurred in 7.4% of patients, which is comparable to stroke rates after elective aortic surgery of 8.1% to 8.7% at our institution as well as others [10, 11].

Long-term survival in our series was 79.2% at 1 year, 62.8% at 5 years, and 46.3% at 10 years. These finding are very similar to other reports, which range from 60% to 84% at 1 year [4, 12–16], 45% to 72% at 5 years [3, 4, 12–17], and 37% to 56% at 10 years [3, 4, 13, 15–17]. In the 4 patients who underwent separate AV replacement and ascending graft replacement with retention of the sinus segment, there was a trend toward worse long-term outcome both in survival and need for proximal reoperations. We believe that procedure should only be preformed in compromised patients in whom AV resuspension has failed yet sinus repair is successful.

On univariate analysis, long-term survival is primarily dependent on patient substrate and underlying diseases, agreeing with other reports [12]. Multivariate analysis found the strongest risk factors associated with decreased survival were perioperative neurologic status, including prior history of stroke and cerebral malperfusion. The length of CPB was also a significant but weaker risk factor. The use of composite valve graft has been associated with decreased early survival [3]. Our data confirm that in-hospital mortality is significantly higher for patient who underwent composite root replacement compared with AV resuspension. The reason remains unclear, even though requirement for root replacement may be a marker for more severe dissection and clearly lengthens the operative time. The long-term survival for these two groups, however, was not different.

The freedom from reoperations after AV resuspension has not been clearly established:

• Kirsch and colleagues [4] reported 130 patients who underwent AV resuspension. Freedom from proximal reoperation for all cases (AV resuspension and root procedures) was 81.7% at 5 years and 71.3% at 10 years. The degree of preoperative AI was a risk factor for reoperation.
• Sabik and colleagues [3] reported 208 patients with acute and chronic dissections and found freedom from proximal reoperation was 96% at 5 years and 93% at 10 years.
• Casselman and colleagues [18] reported 246 cases in 25 years where 121 had AV resuspension. Freedom from aortic root reoperation was 89% at 5 years and 69% at 10 years. Annular diameter exceeding 27 mm was a risk factor.
• Von Segesser and colleagues [13] reported 200 patients where 114 had a preserved aortic root. Freedom from late events (valve dysfunction, thrombotic and bleeding complications and endocarditis) was 88.3% at 5 years and 81.3% at 10 years.

We put significant effort in obtaining a complete follow-up, and only 2 patients were lost to follow-up. Eleven patients (9 had AV resuspension) required proximal reoperation, most commonly due to severe AI or pseudoaneurysm at the proximal suture line. The freedom from proximal reoperation after all operations was 95.1% at 5 years and 77.8% at 10 years. The freedom from proximal reoperation in the patients that underwent AV resuspension was 94.6% at 5 years and 76.8% at 10 years.

Preoperative AI was present in 78% of patients. Worse AI (3 to 4+) resulted in more root replacements. However, preoperative AI grade exceeding 2+ in patients who underwent AV resuspension was not a predictor for proximal reoperation, contrary to other reports [4, 19], demonstrating that in properly selected patients with severe AI, AV resuspension results in acceptable long-term durability. Grade of AI after repair was never more than 2+ in our series. Furthermore, the grade of AI immediately after repair did not predict need for proximal reoperation.

Coronary malperfusion was associated with higher need for reoperation after AV resuspension on both univariate and multivariate analysis. The results of this study indicate that this patient population should undergo root replacement because coronary malperfusion appears to be a marker of severity of destruction of the root. The role of valve-sparing root replacement in type A dissection is an attractive option with short-term and mid-term outcomes comparable with AV resuspension techniques [20], but the long-term outcome is far from clear.

The fate of the aorta distal to the replaced segment after acute type A dissection repair has also not been defined in the current era:

• Kirsch and colleagues [4] reported 160 patients, where freedom from distal reoperations was 92.5% at 5 years and 77.0% at 10 years. Only 11.3% of patients in their series underwent open aortic arch repair under HCA. Risk factors for reoperations were young age, DeBakey type I dissection, and recent operative date.
• Sabik and colleagues [3] reported 208 patients, with freedom from distal reoperation of 95% at 5 years and 91% at 10 years, but one-third had chronic dissection.
• Kasui and colleagues [21] reported 138 cases of acute dissection, where most underwent total arch replacement. Freedom from reoperation was 77.2% at 10 years, with no difference in need for reoperation between total arch and hemiarch replacement.

In our series, 16 patients required distal reoperation, most commonly due to aneurysmal dilatation of residual descending aortic dissection but also for pseudoaneurysm at the distal suture line. The freedom from distal reoperation was 86.5% at 5 years and 75.4% at 10 years. Younger age (<45 years) and DeBakey type I dissection were significant risk factors for distal reoperation by multivariate analysis, and Marfan syndrome was a significant risk factor on univariate analysis.

It is difficult to compare these reports owing to potential differences in selection of patients that undergo replacement of thoracoabdominal aorta, a procedure generally associated with a high incidence of complications and often performed only as a last resort. We have followed up all of our residual dissections with serial imaging at least yearly and have offered surgery if yearly growth exceeds 0.75 cm or when the absolute maximal diameter exceeds 6.5 cm. Six of the distal reoperations, however, were performed to treat symptomatic distal suture line pseudoaneurysm or ruptures.

The high reoperation rate in this and other series is of concern, as is the high mortality rate of 31.2% after distal reoperations. Our results support a change toward more frequent use of total arch replacement with elephant trunk in patients younger than 45 and in patients with Marfan disease. Our database did not allow us to assess for the presence of persistent false lumen in the residual aorta or quantify size or growth rate of the descending aneurysms in our patients.

In addition to a greater use of total arch replacement in younger patients or those identified with collagen-vascular disease, we have started to address the residual dissection in the aorta distal to the replaced arch by deploying a covered stent graft into the distal arch/proximal descending thoracic aorta during open arch repair. The long-term outcome of stenting the residual dissected proximal descending aorta remains to be seen, and we plan to report our data as they become available. Our hypothesis is that acute stenting of the descending thoracic aorta in DeBakey I dissections will significantly decrease the need for distal reoperations.

In conclusion, we report improved in-hospital and long-term survival after our operative approach for acute type A aortic dissection. Significant risk factors for mortality include history of stroke, cerebral malperfusion, and length of CPB. Our standardized technique has improved long-term durability of the repaired residual proximal aorta and root, resulting in improved freedom from proximal reoperation.

Our data support that AV resuspension techniques are durable and have the same long-term survival as root replacement. The selection of the type of proximal operation during initial repair should depend on the condition of the valve leaflets and the extent of root involvement. Patients with coronary malperfusion have higher risk of root reoperation and should generally have root replacement.

Our distal reoperation rate is still significant and, furthermore, distal reoperations remain highly morbid procedures. Patients younger than 45, with DeBakey type I dissection and Marfan syndrome, have a higher risk of distal reoperation and therefore should be considered for total arch replacement. To further improve outcomes, means to prevent progression of distal aortic disease need to be developed, possibly consisting of stent graft deployment.


   Discussion
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Discussion
Appendix 1
 Appendix 2
 Acknowledgments
 References
 
DR GRAYSON H. WHEATLEY (Phoenix, AZ): Dr Pochettino, that was a very thorough presentation. I had a question about your neurologic events and how you assessed them in terms of what was your algorithm for assessing? Was it gross motor function along with a CT scan demonstration, or was it more controlled? What was your algorithm? And then also, what is your strategy for monitoring the descending thoracic aorta in terms of frequency of CT scans post-procedure?

DR POCHETTINO: We have a neurologist involved in all of our patients. Sixty percent of the patients were monitored intraoperatively. At present our neurologists can monitor the intraoperative EEG from home via a Web-based system. The same neurologists who perform the intraoperative monitoring follow all patients and make the clinical call whether a given patient has had a stroke. Any patient who has a clinical change detected by our neurologic team undergoes a CT scan. If there is no neurologic change, a CT scan is not necessarily performed.

Regarding long-term aortic surveillance, our intent is to follow all patients. Some patients do not come back to us. The vast majority do come back and are seen at 3, 6, and 12 months post-op with CT scans and echos. Thereafter, if their aorta is stable, we follow them once per year with CT scans and echos for life.


   Appendix 1
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Discussion
 Appendix 1
Appendix 2
 Acknowledgments
 References
 
Definitions

• Aortic dissection was classified according to the Stanford system where type A dissection involves the ascending aorta. We further subclassified the distal extent of the dissection according to the DeBakey system where type I involves the arch and the descending aorta and type II involves the ascending aorta up to the arch only.
• Acute dissection was defined by onset of symptoms within 14 days of operative treatment.
• We defined proximal procedure as: aortic valve preserving procedure including AV resuspension, aortic root procedures which included composite root replacement (either mechanical or biological), valve sparing root replacement, separate aortic valve replacement and ascending graft (Wheat) and ascending graft only where patient had undergone prior aortic valve replacement.
• Thoracoabdominal aneurysms were classified according to the Crawford system where extent I involves the distal arch, descending aorta and the abdominal aorta down to the renal vessels. Extent II involves the distal arch, descending aorta and the abdominal aorta down to iliac vessels.
• Malperfusion syndromes were defined according to symptoms from each arterial system. Evidence of dissection flap without symptoms of malperfusion was not included.
• Proximal reoperations were defined as any procedure involving aortic root, aortic valve or proximal anastomosis and indications were classified as severe aortic insufficiency (AI), proximal anastomosis pseudoaneurysm, endocarditis of prosthetic valve, and graft infection.
• Distal reoperations were defined as any procedure of the aortic arch or descending thoracic aorta and indications were classified as thoracoabdominal aneurysm (subclassified according to Crawford), distal anastomosis pseudoaneurysm and graft infection. We did not include operations for abdominal aortic aneurysm or ileofemoral revascularization.


   Appendix 2
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Discussion
 Appendix 1
 Appendix 2
Acknowledgments
 References
 
Variables

• Independent variables used were patient demographic variables, including age, sex, hypertension, coronary artery disease, diabetes mellitus, peripheral vascular disease, chronic obstructive lung disease, chronic renal failure, history of stroke or transient ischemic attacks, bicuspid aortic valve, connective tissue disease (Marfan disease and Ehlers-Danlos disease), prior cardiac operations (coronary artery bypass, aortic valve replacement, mitral valve operation, other).
• Symptoms at presentation included acute chest pain, hypotension, loss of consciousness, preoperative cardiac arrest, hemopericardium, pericardial tamponade, malperfusion (overall, cardiac, cerebral, spinal, renal, mesenteric, iliofemoral, innominate), extent of dissection (DeBakey I, DeBakey II).
• Operative repair variables included:

Type of proximal repair: aortic valve resuspension with ascending graft, aortic valve replacement with ascending graft, valve sparing root replacement with ascending graft, composite root replacement (mechanical or biologic) and ascending graft only;

Type of distal arch repair: hemiarch or total arch replacement.

• Additional operative variable included aortic insufficiency (AI grade 0 to 4+) before and after repair, use of BioGlue (CryoLife, Kennesaw, GA), use of felt neomedia, type of arterial cannulation (femoral artery, axillary artery and ascending aorta), length of cardiopulmonary bypass, length of cross-clamp time, length of hypothermic circulatory arrest, length of RCP, use of cerebral neuromonitoring, and redo sternotomy.
• Reason for root replacement included annuloaortic ectasia, connective tissue disorder, destroyed by dissection (tear into sinus segment), aortic stenosis, bicuspid valve, mechanical valve dysfunction.
• Dependent outcome variables included postoperative complications, consisting of reoperation for bleeding, perioperative myocardial infarction, sternal wound infection, sepsis, cerebral complications (stroke, transient ischemic attack, unresponsiveness >24 hours, delirium), acute renal failure, need for dialysis, more than 24 hours on ventilator, pneumonia, acute limb ischemia, need for peripheral revascularization, multisystem organ failure, atrial fibrillation, tracheostomy.
• Mortality variables included overall mortality, intraoperative mortality, 30-day mortality, in-hospital mortality.
• Reoperation variables included proximal reoperations (type, indication), distal reoperation (type, indication), reoperative mortality.


   Acknowledgments
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Discussion
 Appendix 1
 Appendix 2
 Acknowledgments
References
 
We appreciate the database management provided by Katherine Cornelius, BSN, RN, and statistical expertise contributed by Sonnad Seena, PhD.


   References
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 Discussion
 Appendix 1
 Appendix 2
 Acknowledgments
 References
 

  1. Anagnopoulos CE, Prabhakar MJS, Kittle CF. Aortic dissections and dissecting aneurysms Am J Cardiol 1972;30:263-273.[Medline]
  2. Clouse WD, Hallett JW, Schaff HV, et al. Acute aortic dissection: population-based incidence compared with degenerative aortic aneurysm rupture Mayo Clin Proc 2004;79:176-180.[Abstract/Free Full Text]
  3. Sabik JF, Lytle BW, Blackstone EH, McCarthy PM, Loop FD, Cosgrove DM. Long-term effectiveness of operations for ascending aortic dissections J Thorac Cardiovasc Surg 2000;119:946-962.[Abstract/Free Full Text]
  4. 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;123:318-325.[Abstract/Free Full Text]
  5. Erasmi AW, Stierle U, Bechtel JFM, Schmidtke C, Sievers HH, Kraatz EG. Up to 7 years’ experience with valve-sparing aortic root remodeling/reimplantation for acute type A dissection Ann Thorac Surg 2003;76:99-104.[Abstract/Free Full Text]
  6. Hagan PG, Nienaber CA, Isselbacher EM, et al. The international registry of acute aortic dissection (IRAD) JAMA 2000;283:897-903.[Abstract/Free Full Text]
  7. Bavaria JE, Brinster DR, Gorman RC, Woo YJ, Gleason T, Pochettino. Advances in the treatment of acute type A dissection: an integrated approach Ann Thorac Surg 2002;74:S1848-S1852).[Abstract/Free Full Text]
  8. Bavaria JE, Woo YJ, Hall RA, Wahl PM, Acker MA, Gardner TJ. Circulatory management with retrograde cerebral perfusion for acute type A aortic dissection Circulation 1996;94(suppl II):II-173-II-176.[Medline]
  9. Stecker MM, Cheung AT, Pochettino A, et al. Deep hypothermic circulatory arrest: IEffects of cooling on electroencephalogram and evoked potentials. Ann Thorac Surg 2001;71:14-21.[Abstract/Free Full Text]
  10. Augoustides JG, Floyd TF, McGarvey ML, et al. Major clinical outcomes in adults undergoing thoracic aortic surgery requiring deep hypothermic circulatory arrest: quantification of organ-based perioperative outcome and detection of opportunities for perioperative intervention J Cardiothorac Vasc Anast 2005;19:446-452.
  11. McKhann GM, Grega MA, Borowicz Jr LM, et al. Stroke and encephalopathy after cardiac surgery: an update Stroke 2006;37:562-571.[Abstract/Free Full Text]
  12. Lai DT, Miller DC, Mitchell RS, et al. Acute type A dissection complicated by aortic regurgitation: composite valve graft versus separate valve graft versus conservative valve repair J Thorac Cardiovasc Surg 2003;126:1978-1986.[Abstract/Free Full Text]
  13. Von Segesser LK, Lorenzetti E, Lachat M. Aortic valve preservation in acute type A dissection: is it sound? J Thorac Cardiovasc Surg 1996;111:381-391.[Abstract/Free Full Text]
  14. Kawahito K, Adachi H, Yamaguchi A, Ino T. Preoperative risk factors for hospital mortality in acute type A aortic dissection Ann Thorac Surg 2001;71:1239-1243.[Abstract/Free Full Text]
  15. Pansini S, Gagliardotto PV, Pompei E, et al. Early and late risk factors in surgical treatment of acute type A aortic dissection Ann Thorac Surg 1998;66:779-784.[Abstract/Free Full Text]
  16. Bachet J, Goudot B, Dreyfus GD, et al. Surgery for acute type A dissection: the Hospital Foch experience (1977–1998) Ann Thorac Surg 1999;67:2006-2009.[Abstract/Free Full Text]
  17. Moon MR, Sundt TM, Pasque MK, et al. Does the extent of proximal or distal resection influence outcome for type A dissections? Ann Thorac Surg 2001;71:1244-1250.[Abstract/Free Full Text]
  18. Casselman FP, Tan EH, Vermaulen FE, Kelder JC, Morshuis WJ, Schepens MM. Durability of aortic valve preservation an root reconstruction in acute type A dissection Ann Thorac Surg 2000;70:1227-1233.[Abstract/Free Full Text]
  19. Pessotto R, Santini F, Pugliese P, et al. Preservation of the aortic valve in acute type A dissection complicated by aortic regurgitation Ann Thorac Surg 1999;67:2010-2013.[Abstract/Free Full Text]
  20. Erasmi AW, Stierle U, Bechtel JFM, Schmidtke C, Sievers HH, Kraatz EG. Up to 7 years’ experience with valve-sparing aortic root remodeling/reimplantation for acute type A dissection Ann Thorac Surg 2003;76:99-104.[Abstract/Free Full Text]
  21. Kazui T, Yamashita K, Washiyama N, et al. Impact of an aggressive surgical approach on surgical outcome in type A aortic dissection Ann Thorac Surg 2002;74:S1844-S1847.[Abstract/Free Full Text]



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