Aortic Dissection Type Research Articles

Successful emergency double valve repair operation during acute aortic dissection type A

Reconstructive valve surgery in acute aortic dissection type A (AADTA) remains challenging. We describe a case of successful combined repair of the aortic and mitral valves, and replacement of the ascending aorta after AADTA with aortic and mitral insufficiency. Mitral valve repair was achieved by quadrangular resection of the posterior leaflet, combined with ring annuloplasty. Aortic valve repair was achieved by Cabrol commissural sutures with resuspension of the annulus. The postoperative clinical course was uneventful and an echocardiogram revealed competent mitral and aortic valves. Mitral and aortic valve repair is an option in AADTA with mitral and aortic valve insufficiency.

EComment. Acute aortic dissection type A: which strategy of the arterial perfusion to choose?

We read with the great interest the report of Conzelmann and colleagues [1], describing the original method of direct aortic cannulation and we congratulate the authors for their excellent results. However, the separation between the adventitial layers of the ascending aorta and the pulmonary artery can lead to rupture of the aorta in this area. In addition, direct cannulation of the true aortic can be complicated by thromboembolism in the case of the false lumen thrombosis. Inadequate organ perfusion is one of the major problems in patients with acute type A aortic dissection (AADA). Until recently, the retrograde perfusion via the femoral artery was the perfusion mode of choice in thoracic aortic surgery [2]. But in some cases, this was marked by a high risk of potential malperfusion and atheroembolic complications associated with retrograde perfusion, especially in dissections. In recent years, subclavian artery cannulation for AADA has become a widely accepted arterial access for antegrade aortic and cerebral perfusion [3,4]. Surgical exposure of the subclavian artery is easy to perform, and if the operative field and the patient are routinely prepared for this procedure, it is rapidly performed. At our institute, 148 patients with AADA underwent surgery. As of 2004, we have been using the subclavian arterial perfusion in the majority of patients. This has led to a significant reduction in the incidence of postoperative multiple organ failure, and has reduced hospital mortality (from 24% to 8-10% in recent years). In our practice, surgical exposure and cannulation of subclavian artery usually require an additional 5-10 minutes, but in any case, it does not affect the outcome of the operation. We have rarely found heavily diseased subclavian arteries and involvement of a subclavian artery by the dissection process is also rare. In addition, the use of this technique facilitates the work of the surgeon at the expense of absence of arterial cannula in a working zone, as well as reduces the risk of embolic complications. All this, in our opinion, makes this method more preferable. However, in emergency situations with highly unstable haemodynamics or in case of dissections extending into the innominate artery, the method described by the authors may be useful [1]. In conclusion, we would like to note that the ascending aortic cannulation of the true lumen under direct vision deserves serious consideration as a safe and rapid way to ensure antegrade arterial perfusion in same unstable patients with acute type A dissection. However, this method requires further study.

Editorial Comment: Moderate aneuryms of the ascending aorta in stenotic bicuspid aortic valve - life threatening or merely an epiphenomenon?

The current US guidelines for the diagnosis and management of patients with thoracic aortic disease recommend an operation for asymptomatic patients with bicuspid aortic valve (BAV) and aneurysm of the ascending aorta with a diameter of 4-5 cm [1]. With this recommendation, patients with BAV and ascending aortic aneurysms are treated following the same criteria as patients with Marfan syndrome. The guidelines categorize both diseases together as ‘Marfan syndrome or other genetically mediated disorders’. The background for this recommendation is growing evidence that BAV, the most common congenital abnormality, with an incidence of 1–2%, is related to a gene defect. For example, a mutation of the NOTCH1 gene is linked to development of BAV [2]. Therefore, systemically weakened aortic tissue will subsequently lead to an increased incidence of aortic aneurysm formation and aortic dissection in these patients. However, this recommendation carries a grade ‘C’ level of evidence. That means the recommendation is only based on the consensus opinion of experts, case studies or standards of care, but not on more appropriate methods of evidence-based medicine, such as randomized controlled trials. The paucity of studies in the literature to support the recommendation is evident. Girdauskas et al. recently questioned the theory that BAV is predominantly caused by an underlying genetic disorder [3]. In a review of the literature, they convincingly speculated that aneurysm formation in individuals with BAV may be related to abnormal haemodynamics more often than to a genetic disorder. They postulated the re-evaluation of the ‘genetic theory’ and asked for further studies aiming to determine the nature of aneurysm formation. This ‘haemodynamic theory’ would have an important impact on the treatment of this entity, because aortic valve replacement (AVR) aborts the asymmetric flow patterns in BAV, so that further dilatation of the ascending aorta becomes unlikely. However, there are controversial data in the literature demonstrating that acute aortic dissection and sudden death is significantly increased after AVR in patients with BAV compared with patients who have tricuspid aortic valves [4]. In this issue of the European Journal of Cardio-Thoracic Surgery, Girdauskas’s group add another piece of evidence to the puzzle, aiming to determine the best treatment of patients with stenotic BAV and moderate aneurysm of the ascending aorta [5]. They report on 153 consecutive patients with BAV stenosis and ascending aortic dilatation of 4–5 cm who underwent isolated AVR between 1995 and 2000. The concept was rather conservative, because 97% received mechanical valve prostheses and the ascending aorta was not replaced. The 30-day mortality was remarkably low, being 0.7%, and long-term survival was also favourable. Surprisingly, late aortic events were rare, and freedom from aortic intervention was 97 and 94% at 10 and 15 years, respectively, with only five patients (3%) requiring reoperation for progressive ascending aortic aneurysm. No aortic dissection or rupture occurred. Ascending aortic diameter was not found to be a predictor for adverse aortic events. Looking more closely at their report, a group of 21 young (mean age 41 years) and predominantly male (86%) patients with BAV and aortic valve insufficiency were treated in the same way as described. For these patients with the so-called ‘root phenotype’, adverse aortic events were significantly more often observed, at 24%, including two acute aortic dissections type A. These findings support the theory that abnormal haemodynamics are responsible, at least in part, for aortopathy in stenotic biscuspid valve disease. This entity is often called ‘poststenotic dilatation’. From these data, the aortopathy is sufficiently treated by AVR. Consequently, the current guidelines recommending ascending aortic replacement in patients with BAV and aneurysm of the ascending aorta with a diameter of 4– 5c m based on the ‘genetic theory’ need to be re-evaluated, and isolated AVR may be an option. The Bentall procedure with either mechanically or biologically valved conduits is considered a safe operation for BAV combined with an ascending aneurysm, with low early mortality in experienced centres [6]. However, a simple AVR results in better early outcomes than the Bentall procedure, with a 30-day mortality of 3 vs. 8% in Germany in 2010 [7]. Furthermore, adverse events and reoperation after conduit replacement are reported in all long-term studies, especially for biologically valved conduits [8], demonstrating that this strategy also is far from perfect. Supracoronary replacement of the ascending aorta can be an option in older patients with a preserved sinotubular junction and a ‘normal’ appearing aortic wall tissue. However, potentially

Aortic valve sparing operations versus composite graft implantation in acute aortic dissections

ObjectivesType A acute aortic dissection is life threatening disease requiring urgent operation. This type of the operation is often a subject of discussion. In our study we present our first experience with two different types of operations with and without preservation of the aortic valve. Patients and methodsFrom January 2009 to December 2011 fifty six patients underwent the operation due to the acute aortic dissection type A. Ascending aorta was replaced in 32 cases and more complex operation was performed in 24 patients due to the simultaneous severe aortic root damage by dissection (study group). In eleven patients (group A) replacement of aortic valve, aortic root and ascending aorta by composite graft (modified Bentall procedure) was performed and in 13 patients (group B) valve sparing operation (reimplantation according to David) was carried out. ResultsThere were no significant differences between the groups in preoperative variables. The only significant difference was mean duration of hospitalisation; 26.7±13.7 days in group A and 16.4±7.7 days in group B. Hospital mortality was 18.2% (n=2) after Bentall procedure, no patient died in group B. There were no or minimal aortic regurgitation in all patients of group B on echocardiography before discharge. The mean follow-up was 17.6 months (3.6–35.8) in group A, and 23.5 months (7.9–38.9) in group B. During this period of time three patients in group A and one patient in group B died; two of cardiac and two of noncardiac reasons. In group B no patient had aortic regurgitation higher than grade I and all patients were in New York Heart Association functional class I or II. ConclusionAortic valve reimplantation in patients with type A dissection can be performed with excellent early and mid-term results. In the hands of an experienced surgeon it represents a good alternative to the Bentall operation. Its main advantage is the preservation of the native valve without the necessity of anticoagulation therapy.

Invited Commentary

Invited Commentary

Total Arch Replacement With Stented Elephant Trunk Technique for Acute Type B Aortic Dissection Involving the Aortic Arch

Optimal management of patients with acute type aortic dissection is not clear. The clinical experience with total arch replacement combined with stented elephant trunk technique in the treatment of acute type B aortic dissection involving the aortic arch was analyzed. From January 2006 to April 2011, 24 consecutive patients with acute type B aortic dissection involving the aortic arch underwent total aortic arch replacement with stented elephant trunk implantation. Concomitant procedures included the Bentall procedure in 3 patients, David procedure in 1 patient, and ascending aortic replacement in 7 patients. The times of cardiopulmonary bypass and selective cerebral perfusion averaged 168±41 and 21±4 minutes, respectively. One patient died of multiorgan failure 3 days after surgery. Complications occurred in 3 patients (3 of 24; 12.5%), including hoarseness and mediastinal bleeding requiring reoperation, each in 1 patient. One patient experienced transient consciousness dysfunction. The in-hospital mortality was 4.1% (1 of 24). No paraplegia occurred postoperatively. Follow-up was available in 22 patients (22 of 23; 95.7%). During the follow-up, 1 patient died of massive gastrointestinal bleeding 2 months after surgery. Type II endoleak occurred in 1 patient. One patient underwent thoracoabdominal aortic replacement 14 months after surgery. The complete thrombosis ratio of the false lumen was 86.4% (19 of 22) 6 months after surgery. The 5-year survival was 91.7%. Total arch replacement combined with stented elephant trunk technique was safe and feasible for acute type B aortic dissection involving the aortic arch. A low rate of morbidity and mortality and a satisfactory 5-year survival rate were achieved, as well as improved thrombosis of the false lumen.

What makes the difference between the natural course of a remaining type B dissection after type A repair and a primary type B aortic dissection?

To analyse the outcome and need for intervention [surgery or thoracic endovascular aortic repair (TEVAR)] in patients after surgery for remaining type B dissection after type A repair and primary type B aortic dissection. Within a 10-year period, 247 patients with remaining type B after type A, and 112 patients with primary type B aortic dissection were analysed. We assessed the clinical outcome as well as the need for intervention (surgery or TEVAR) within the aortic arch and the thoracoabdominal aorta as well as risk factors. The median follow-up was 23 months (interquartile range 5-52). There was a significant difference with regard to the status of the primary entry tear between patients after surgical repair of an acute type A aortic dissection and primary acute type B aortic dissection (patent vs. non-patent entry 35 vs. 83%, P < 0.001). The overall need for any kind of intervention (surgery or TEVAR) was 19%. Multivariate Cox regression analysis revealed a patent primary entry tear in patients after surgery for acute type A aortic dissection as an independent predictor for intervention (surgery or TEVAR) during follow-up [odds ratio (OR) 6.4; confidence interval (CI) 1.39-29.81, P = 0.017]. Multivariate Cox regression analysis did not reveal a patent primary entry tear in patients after acute type B aortic dissection as an independent predictor for intervention (surgery or TEVAR) during follow-up (OR 0.67; CI 0.27-1.69, P = 0.671). Finally, the thrombosis status of the false lumen was not an independent predictor for intervention (surgery or TEVAR) either in patients after surgery for acute type A aortic dissection (OR 3.46; CI 0.79-15.16, P = 0.100) or in patients after acute type B aortic dissection (OR 0.77; CI 0.31-1.93, P = 0.580). A remaining type B dissection after type A repair and a primary type B aortic dissection represent two distinct pathophysiological entities with regard to late outcome. The need for any kind of intervention in the thoracoabdominal aorta is significantly higher in primary type B aortic dissections. A remaining patent primary entry tear independently predicts the need for intervention (surgery or TEVAR) in patients after surgery for acute type A aortic dissection and, thereby, remains the main target of initial therapy. The thrombosis status of the false lumen seems to be of secondary importance.

Analysis of risk factors for neurological dysfunction in patients with acute aortic dissection type A: data from the German Registry for Acute Aortic Dissection Type A (GERAADA)

Acute aortic dissection type A (AADA) is associated with major adverse events, such as transient or persistent neurological dysfunction (ND), which may be patient-, disease- or surgery-related. There is a lack of consensus regarding risk factors for ND in AADA patients. The aim of this study was to analyse and identify risk factors for new postoperative ND after aortic repair for AADA. Between July 2006 and June 2010, 2137 AADA patients were enrolled in the multi-centre, prospective German Registry of AADA (GERAADA). Perioperative data were prospectively gathered from 50 institutes in Austria, Switzerland and Germany, and multivariate logistic regression analysis was performed to determine the independent predictors of new onset ND. ND occurred in 20.3% of all patients prior to surgery, 12.6% of which resolved postoperatively and 7.7% persisted. New ND after AADA surgery occurred in 9.5% of patients. Risk factors for an increased rate of postoperative new ND were malperfusion syndrome of three or more territories prior to surgery [odds ratio (OR) = 2.206, P = 0.0065], dissection of the supraaortic vessels (OR = 1.468, P = 0.0103) and longer operating time (OR = 1.002 per min, P = 0.0001). New postoperative ND was associated with an increased rate of mortality (22.5 vs. 16.1%, P = 0.0087). Arterial cannulation site had no statistically significant impact on neurological outcomes. Neurological complications are associated with increased mortality post-AADA repair. New onset ND is associated with extensive malperfusion syndrome, supraaortic vessel dissection and operative time and does not seem to be affected by choice of arterial cannulation site.

How to do it: direct true lumen cannulation technique of the ascending aorta in acute aortic dissection type A†

In acute aortic dissection type A (AADA), direct true lumen cannulation (DTLC) of the ascending aorta is a fast and safe cannulation site providing antegrade perfusion of the supraaortic and visceral vessels. An Overholt clamp is passed around the ascending aorta to place a Mersilene tape for later securing of the arterial cannula. After draining venous blood into the cardiopulmonary bypass system (CPB), the ascending aorta is transected and the aortic lumen inspected. The true lumen is identified and an arterial cannula inserted directly. Finally, the cannula is secured with the previously placed tape and CPB is initiated. DTLC can be used as arterial cannulation standard technique in operations for AADA.

Outcomes for Acute Type A Aortic Dissection: Effects of Previous Cardiac Surgery

The standard of performing emergent surgical repair for acute aortic dissection type A has been questioned in patients with previous cardiac surgery. The effects of previous cardiac surgery on the presentation and operative outcome of these patients is understudied. Between 1998 and 2010, 190 patients were operated on for acute type A aortic dissection; there were 159 first cardiac operations (FCO) and 31 redo operations (REDO). Stepwise logistic regression analysis identified independent predictors of hospital mortality. Propensity score-matching yielded 31 FCOs who matched the REDOs with respect to age, sex, hypertension history, chronic obstructive pulmonary disease, and renal failure. The presentation, operative outcome, and complications were compared between the two groups. Hospital mortality rate was 16.8% (32 of 190). Regression analysis identified mental status change (odds ratio [OR] = 5.9), hypertension (OR = 4.6), concomitant coronary artery bypass grafting (OR = 3), reoperation (OR = 2.9), and age of 70 years or older (OR = 2.8) as predictors of hospital mortality. After matching there was no difference between REDO and FCO groups in the presenting symptoms, but REDOs had a higher incidence of aortic rupture (29% [9 of 31] versus 3.2% [1 of 31]; p = 0.012). Cardiac tamponade was present in 3.2% (1 of 31) of REDOs versus 16.1% of FCOs (5 of 31; p = 0.195). Patients in the REDO group required more intraoperative blood transfusion, and had longer cardiopulmonary bypass time. Major complications occurred similarly between the two groups, except REDOs had worse renal function and a higher rate of sudden cardiac arrest (14.3% [4 of 28] versus 0; p = 0.045). Although hospital mortality is higher among REDOs, it is still lower than the reported mortality for medical management, and major complications occurred at a rate similar to that of FCOs; hence, emergent surgery remains the prudent treatment.

Repair of stent graft-induced retrograde type A aortic dissection using the E-vita open prosthesis

Stent graft-induced retrograde type A dissection is a life-threatening complication after endovascular treatment of acute aortic type B dissections. From August 2005 to February 2011, retrograde aortic dissection occurred in 4 of 29 patients (13.8%) undergoing thoracic endovascular aortic repair (TEVAR) for acute complicated aortic type B dissection. Three patients underwent emergent surgical conversion immediately after TEVAR. The operative strategy was a combined surgical and endovascular approach (frozen elephant trunk technique) using a specially designed hybrid prosthesis (Jotec E-vita open). All operations were performed under moderate hypothermia (25-28°C) and selective bilateral antegrade cerebral perfusion. The mean duration of circulatory arrest was 56 ± 7 min. Operative data and the outcome of surgery were analysed retrospectively. Data were analysed retrospectively in the limited number of patients. All patients survived the surgical procedure. No stroke, paraplegia, renal failure or other major complications occurred. Postoperative CT scans revealed perigraft thrombus formation and stable aortic dimensions in all patients after 6 months. In one patient, the retrograde dissection remained primarily undetected and untreated. The patient died suddenly, with no clinical signs, within 7 days after stent graft implantation. Autopsy revealed cardiac tamponade due to retrograde type A aortic dissection. Retrograde aortic dissection type A is a serious complication of thoracic endovascular repair of acute aortic type B dissection. Despite the small number of patients investigated in this study, the frozen elephant trunk technique appears to be a feasible bail-out strategy for the treatment of these acute aortic events.

The glue crisis in surgery of acute aortic dissection type A is ongoing

have two questions. The first question refers to the cannulation. You cannulated all patients through the ascending aorta using the Seldinger technique and epiaortic echo. Could you explain how you managed to reach the true lumen and whether you had problems? Your data showed an increase in the percentage of patients with moderate aortic regurgitation, from 3% post-operatively to 19% at follow-up. Thirty-eight percent of the patients with pre-operative moderate or severe aortic regurgitation had moderate aortic regurgitation again at follow-up, which reflects the data in the literature for such patients. The average age of the patients was 68 years. And because of that, I would like to ask whether it would be an option for you, looking at your data now, to replace these valves intraoperatively? Dr Yamanaka: I would like to answer the first question. In our series, we used central cannulation in more than 80% of patients; the other sites for cannulation were the right axillary artery or the femoral artery. We usually perform central cannulation guided by epiaortic and transoesophageal echo. We initially check the ascending aorta by epiaortic echo and decide the site of puncture and we insert a guidewire and check whether it is located in the true lumen using both epiaortic and transoesophageal echo. Finally we insert a cannula using Seldinger’s method. We try central cannulation wherever possible in all patients. If the patients’ haemodynamics are unstable, we alternatively use apex cannulation. And once again the second question? Dr Pfannmueller: Would you replace the valves now if you know that 38% of the patients with previous moderate or severe aortic regurgitation have moderate aortic regurgitation again and the average age of the patients is 68 years? Dr Yamanaka: Usually, we don’t replace the aortic valve in cases of moderate aortic regurgitation. I think most of the patients had normal valvular function previously, but the proximal extension of the dissection process caused acute aortic regurgitation as a result of the loss of the commissure support, so I think it’s not related to the severity of the aortic regurgitation perioperatively. Accordingly, we try to save the aortic valve whenever possible except for pathological dilated aorta.

Aortic dissection type A: Perioperative impact of abdominal extent

Aortic dissection type A: Perioperative impact of abdominal extent

Outcome after surgery for acute aortic dissection type A in young patients: Results from the German Registry for Acute Aortic Dissection type A (GERAADA)

Outcome after surgery for acute aortic dissection type A in young patients: Results from the German Registry for Acute Aortic Dissection type A (GERAADA)

Endovascular treatment of persistent true lumen collapse of the descending aorta after open surgery for acute aortic dissection type A

Endovascular treatment of persistent true lumen collapse of the descending aorta after open surgery for acute aortic dissection type A

Adventitial Inversion with Graft Telescopic Insertion for Distal Anastomosis in Acute Type A Aortic Dissection

One current method of anastomosis in aortic dissection type A is the adventitial inversion technique. To improve hemostasis at the anastomotic site, we have developed a novel technique for distal anastomosis involving adventitial inversion employing graft telescopic insertion. The adventitia was inverted into the aortic lumen and the anastomosis with a Dacron tube-graft was made in a telescopic method, covering the inverted adventitia. Five patients have undergone emergency ascending aortic replacement for aortic dissection by one surgeon using this technique. There have been no reoperations for bleeding or false aneurysm. Complete coverage of the inverted adventitia eliminated the potential risk of thrombus formation. Graft telescopic insertion lead to complete hemostasis.

Clinical application of 640-slice volume CT angiography in follow-up observation of Stanford B type aortic dissection after endovascular exclusion

Clinical application of 640-slice volume CT angiography in follow-up observation of Stanford B type aortic dissection after endovascular exclusion

Cerebral Protection During Surgery for Acute Aortic Dissection Type A: Results of the German Registry for Acute Aortic Dissection Type A (GERAADA)

Cerebral Protection During Surgery for Acute Aortic Dissection Type A: Results of the German Registry for Acute Aortic Dissection Type A (GERAADA)

Endovascular correction of abdominal aortic aneurysm as a late complication of type A aortic dissection

Aortic dissection type A has a great mortality in its acute phase with low annual survival without surgical treatment. Although the chronic cases are exceptions the late complications exist and should be treated.

Ischemic stroke with left hemiparesis or shock should be evaluated by computed tomography for aortic dissection

An 82-year-old woman with consciousness disturbance, left hemeparesis, and dysarthria was discovered at home by her family and was transported to a hospital. On arrival, she remained in a sleepy and disorientated and shock state. She complained of nausea but no chest or back pain. She obtained stable circulation after infusion. Her chest roentgen results showed widening of the mediastinum and the existence of a separation of the intimal calcification from the outer aortic soft tissue border, thus suggesting a Stanford A–type aortic dissection. Her head computed tomography depicted no signs of cerebral infarction. Because she did not complain of any pain, the possibility of acute phase aortic dissection was rejected. A permissive hypertensive therapy was initiated. Next day, she suddenly died. We diagnosed that she had died of a Stanford A–type aortic dissection based on the following facts: (1) patients presenting with stroke due to a Stanford A–type aortic dissection tend to have left hemiparesis because of malcirculation of the innominate artery and (2) a patient presenting with stroke by aortic dissection may have hypotension, which is unusual in standard stoke cases. Ischemic stroke induced by aortic dissection is not common among the patients with aortic dissection. However, given the high morbidity and mortality after misdiagnosis of aortic dissection, patients with ischemic stroke with left hemiparesis or shock should be evaluated by enhanced truncal computed tomography.