When and how to replace the aortic root in type A aortic dissection

Acute type A aortic syndromes: outcomes are independent of aortic root/valve management

Purpose

Clinical outcomes following various surgical intervention strategies for aortic root and valve pathology during repair of acute type A aortic syndromes were studied and compared.

Methods

From 2004 to 2019, 634 patients underwent acute type A aortic repair. Patients were divided into 4 groups: Valve Resuspension (n = 456), Isolated Valve Replacement (AVR) (n = 24), Valve and Root Replacement (ROOT) (n = 97), and Valve Sparing Root Replacement (VSRR) (n = 57). The primary endpoint was midterm survival and multivariable risk factor analysis was performed.

Results

The mean age was 55.4 ± 13 years, 424 (67%) were male, and overall early mortality was 12%. Early mortality was 13%, 8%, 11%, and 7% for the Valve Resuspension, AVR, ROOT, and VSRR groups respectively, p = 0.43. Five-year survival was 74%, 86%, 73%, and 84% for the Valve Resuspension, AVR, ROOT, and VSRR groups respectively, p = 0.46. There was no difference in late stroke, renal failure, heart block, and late bleeding (p > 0.05 for all). At late follow-up, AVR and ROOT patients had a higher mean gradient versus Valve Resuspension and VSRR patients, p < 0.0001. For the total cohort, risk factors for late mortality included preoperative peripheral vascular disease (hazard ratio (HR) 2.3, 95% confidence interval (CI) 1.2-4.4, p = 0.009) and preoperative dialysis (HR 2.8, 95% CI 1.3-6.1, p = 0.01).

Conclusion

Mid-term survival following repair of acute type A aortic dissection is not independently associated with a specific type of aortic valve intervention. Native valve preservation leads to acceptable mid-term valve hemodynamics and should be the preferred therapy in this emergent clinical setting.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01602-8.

In-hospital outcomes predictors and trends of redo sternotomy aortic root replacements: insights from a UK registry analysis

Background

Redo sternotomy aortic root surgery is technically demanding, and the evidence on outcomes is mostly from retrospective, small sample, single-centre studies. We report the trend, early clinical results and outcome predictors of redo aortic root replacement over 20 years in the United Kingdom.

Methods

We retrospectively analysed collected data from the UK National Adult Cardiac Surgery Audit (NACSA) on all redo sternotomy aortic root replacements performed between 30th January 1998 and 19th March 2019. We analysed trends in the volume of operations, characteristics of hospital survivors vs. non-survivors, and predictors of in-hospital outcomes.

Results

During the study period, 1,107 redo sternotomy aortic root replacements were performed (median age 59, 26% of patients were females). Eighty-four per cent of cases (N = 931) underwent a composite root replacement, 11% (N = 119) had homograft root replacement and valve-sparing root replacement was performed in 5.1% (N = 57) of cases. There was a steady increase in the volume of redo sternotomy root replacements beyond 2006, from an annual volume of 22 procedures in 2006 to 106 procedures in 2017. Hospital mortality was 17% (n = 192), postoperative stroke or TIA occurred in 5.2% (n = 58), and postoperative dialysis was required in 11% (n = 109) of patients. Return to the theatre for bleeding/tamponade was required in 9% (n = 102) and median in-hospital stay was 9 days. Age >59 (OR: 2.99, CI: 1.92-4.65, P < 0.001), recent myocardial infarction (OR: 6.42, CI: 2.24-18.41, P = 0.001) were associated with increased in-hospital mortality. Emergency surgery (OR: 3.95, 2.27-6.86, P < 0.001), surgery for endocarditis (OR: 2.05, CI: 1.26-3.33, P = 0.001), salvage coronary artery bypass grafting (OR: 2.20, CI: 1.37-3.54, P < 0.001), arch surgery (OR: 2.47, CI: 1.30-3.61, P = 0.018) and aortic cross-clamp longer than 169 min (OR: 2.17, CI: 1.00-1.01, P = 0.003) were associated with increased risk of mortality. We found no effect of the centre or surgeon volume on mortality (P > 0.05).

Conclusions

Redo sternotomy aortic root replacement still carries significant morbidity and mortality and is sporadically performed across surgeons and centres in the UK.

Survival following acute type A aortic dissection: a multicenter study

Background

While surgery is almost always indicated for acute type A aortic dissections (ATAADs), the extent of surgery is often debated, with some surgeons preferring a conservative option and others preferring a more radical option This study aims to assess the outcome after surgery for ATAAD and the prognostic impact of surgical strategy (with vs. without aortic arch replacement).

Methods

Data was gathered between 1 January 2005 and 31 December 2021 and retrospectively analyzed with multivariable logistic and Cox regression to ascertain risk factors and survival respectively.

Results

A total of 601 patients underwent type A aortic dissection repair across the recruiting centers with an operative mortality of 24.3% (146 patients) which was considerably linked with the clinical condition at presentation. In-hospital mortality was 23.1% for ascending and root replacement alone vs. 28.7% for arch involvement. Overall survival was 73.3% after the first year, 68.2% at 5 years, and 53.5% at 10 years. The median follow-up period was 2.5 years [interquartile range (IQR), 6.6 years]. Aortic arch replacements were more often carried out in younger patients and those without adverse clinical conditions, although outcomes for patients who underwent either surgical option were comparable throughout apart from a higher rate of cerebrovascular complications in the arch group (7.6% vs. 21.9%) (P=0.01).

Conclusions

Surgery for ATAAD still confers a relatively high mortality. In our study, there was a higher stroke rate associated with patients who underwent arch replacements at the time of dissection despite them being younger. The choice of repair with or without arch replacement should be individualized to the patient and the severity of clinical status presentation.

Aortic root remodeling after surgical repair of acute type A aortic dissection using different anastomosis techniques

Background

After surgical repair of acute type A aortic dissection (aTAAD), remodeling of the residual aortic segments is the key outcome parameter associated with late reoperation or aorta-related adverse events. In this study, we analyzed the surgical outcomes of aTAAD using either a telescopic or continuous anastomosis technique, focusing on their impact on aortic root remodeling during the longitudinal follow-up.

Methods

Between 2012 and 2018, 112 surgical repairs of aTAAD with ascending aorta replacement and without aortic arch or aortic root replacement were performed. The medical records were reviewed retrospectively, and early and late outcomes were compared between the telescopic and continuous anastomosis techniques. The generalized estimating equation method was used to analyze the effects of different anastomosis techniques on serial aortic root remodeling.

Results

The telescopic anastomosis technique was used in 46 cases (41.1%), and the conventional continuous anastomosis technique was used in 66 cases (58.9%). There were no differences in in-hospital mortality or the incidence of major complications between the groups. The telescopic anastomosis group demonstrated stable postoperative regression of the aortic root diameter during follow-up. In contrast, the continuous anastomosis group showed a progressive dilatation of the aortic root. There was a trend toward better aortic root adverse event-free survival rates in the telescopic anastomosis group (P = .081).

Conclusions

The telescopic anastomosis technique is a safe alternative to the continuous anastomosis technique in the surgical repair of aTAAD, with comparable early results. In addition, telescopic anastomosis was associated with beneficial aortic root remodeling in the medium term compared with continuous anastomosis.

Lactate-Based Difference as a Determinant of Outcomes following Surgery for Type A Acute Aortic Dissection: A Multi-Centre Study

Type A acute aortic dissection (TAAAD) is a serious condition within the acute aortic syndromes that demands immediate treatment. Despite advancements in diagnostic and referral pathways, the survival rate post-surgery currently sits at almost 20%. Our objective was to pinpoint clinical indicators for mortality and morbidity, particularly raised arterial lactate as a key factor for negative outcomes.

METHODS

All patients referred to the three cardiovascular centres between January 2005 and December 2022 were included in the study. The inclusion criteria required the presence of a lesion involving the ascending aorta, symptoms within 7 days of surgery, and referral for primary surgical repair of TAAAD based on recommendations, with consideration for other concomitant major cardiac surgical procedures needed during TAAAD and retrograde extension of TAAAD. We conducted an analysis of both continuous and categorical variables and utilised predictive mean matching to fill in missing numeric features. For missing binary variables, we used logistic regression to impute values. We specifically targeted early postoperative mortality and employed LASSO regression to minimise potential collinearity of over-fitting variables and variables measured from the same patient.

RESULTS

A total of 633 patients were recruited for the study, out of which 449 patients had complete preoperative arterial lactate data. The average age of the patients was 64 years, and 304 patients were male (67.6%). The crude early postoperative mortality rate was 24.5% (110 out of 449 patients). The mortality rate did not show any significant difference when comparing conservative and extensive surgeries. However, malperfusion had a significant impact on mortality [48/131 (36.6%) vs. 62/318 (19.5%), p < 0.001]. Preoperative arterial lactates were significantly elevated in patients with malperfusion. The optimal prognostic threshold of arterial lactate for predicting early postoperative mortality in our cohort was ≥2.6 mmol/L.

CONCLUSION

The arterial lactate concentration in patients referred for TAAAD is an independent factor for both operative mortality and postoperative complications. In addition to mortality, patients with an upper arterial lactate cut-off of ≥2.6 mmol/L face significant risks of VA ECMO and the need for dialysis within the first 48 h after surgery. To improve recognition and facilitate rapid transfer and surgical treatment protocol, more diligent efforts are required in the management of malperfusion in TAAAD.

Composite aortic root replacement in African patients with type A aortic dissection: report of 12 cases

Type A aortic dissection (TAAD) is associated with high mortality in the absence of appropriate surgical therapy. The involvement of the aortic root by the intimal tear and the presence of severe aortic insufficiency will require a more radical approach with composite root replacement (CRR) in most of the patients. We briefly report our surgical experience following CRR in 12 patients presenting with TAAD in our department. Between November 2009 and January 2022, a total of twelve (n=12) patients diagnosed with TAAD were operated in our institution. Clinical data and surgical outcomes were retrospectively reviewed. The mean age at admission was 51.1 ± 12.43 years (range: 34-72). One patient met the criteria for Marfan´s disease (1/12, 8.3%). The operative mortality was 16.66% (2/12). Composite root replacement with a mechanical valved conduit was performed in the majority (11/12, 91.66%;) whereas a separated supracoronary graft replacement and aortic valve replacement were performed in one patient. Concomitant aortic arch surgery (hemi or total) was done in 9/12 patients (75%). The commonest postoperative complications were: chest re-exploration for bleeding in 2/12 (16.66%), transitory cerebral ischemia in 1/12 (8.33%) and low cardiac output syndrome in 2/12 (16.66%). The mean length of stay in the Intensive Care Unit (ICU) was 4.8±3.8 days (range: 2-17). Delayed referral of patients with TAAD was observed in the majority of patients as they were operated in the subacute or chronic phase. Composite root replacement in these patients is associated with acceptable outcomes despite complex anatomic-pathological lesions.

Combining aortic arch dissection stent implantation and root surgery for aortic dissection type A

BACKGROUND

Acute aortic dissection type A (AADA) is associated with high perioperative morbidity and mortality. A novel non-covered hybrid prosthesis (AMDS, CryoLife, Kennesaw, USA) can be easily implanted to stabilize the true lumen. However, the role of AMDS for patients requiring additional aortic root surgery has not been described.

METHODS

Between 2010 and 2020 a total of n = 370 patients underwent surgery for AADA in our department. Of those, n = 120 underwent treatment for aortic root in addition to proximal arch replacement without resection of the aorta beyond the innominate artery (Control, n = 111) and were compared to patients who received additional AMDS implantation (AMDS, n = 9).

RESULTS

Aortic valve repair was performed in 48.6% (Control) and in 55.6% of AMDS patients. Cardiopulmonary bypass (Control: 248 ± 76 min, AMDS: 313 ± 53 min, P < 0.01) time as well as circulatory arrest time of the lower body (Control: 30 ± 15 min, AMDS: 52 ± 12 min, P < 0.01) was prolonged in the AMDS group. Nevertheless, postoperative in-hospital morbidity such as dialysis (Control: 22.4%, AMDS: 11.1%, P = 0.68) and stroke (Control: 17.0%, AMDS: 22.2%, P = 0.65) were comparable. In-hospital death (Control: 21.8%, AMDS: 11.1%, P = 0.68) and the compound end-point MACCE (Control: 38.7%, AMDS: 44.4%, P = 0.74) did also not differ.

CONCLUSIONS

Addressing the arch by implantation of AMDS prolongs cardiopulmonary bypass and circulatory arrest time, however without relevant impairments of short-term outcome. Combining root surgery with replacement of the proximal aortic arch and AMDS implantation seems feasible and safe as it did not impair the early postoperative outcome.

Managing the Root in Acute Type A Aortic Dissections: Are We Ready for a Standardized Approach?

OBJECTIVES

 Surgical repair of Type A aortic dissection (TAAD) requires exclusion of the primary entry tear and reestablishment of flow into the distal true lumen. Provided that the majority of tears occur within the ascending aorta (AA), replacing only that segment seems a safe option; however, this strategy leaves the root susceptible to dilatation and need for reintervention. We aimed to review the outcomes of the two strategies: aortic root replacement (ARR) and isolated ascending aortic replacement.

METHODS

 Retrospective analysis of prospectively collected data for all consecutive patients who underwent repair of acute TAAD at our institution from 2015 to 2020 was conducted. Patients were divided into two groups: (1) ARR and (2) isolated AA replacement as index operation for TAAD repair. Primary outcomes were mortality and need for reintervention during the follow-up.

RESULTS

 A total of 194 patients were included in the study; 68 (35%) in the ARR group and 126 (65%) in the AA group. There were no significant differences in postoperative complications or in-hospital mortality (23%; p = 0.51) between groups. Seven patients (4.7%) died during follow-up and eight patients underwent aortic reinterventions, including proximal aortic segments (two patients) and distal procedures (six patients).

CONCLUSION

 Both aortic root and AA replacement are acceptable and safe techniques. The growth of an untouched root is slow, and reintervention in this aortic segment is infrequent compared with distal aortic segments, hence preserving the root could be an option for older patients provided that there is no primary tear within the root.

Comparison of outcomes between aortic root replacement and supra-coronary interposition graft for type A aortic dissection: A retrospective case series

BACKGROUND

The decision to conserve or replace the native aortic valve following acute type-A aortic dissection (ATAAD) is an area of cardiac surgery without standardized practice. This single-center retrospective study analysed the long-term performance of the native aortic valve and root following surgery for ATAAD.

METHODS

Between 2009 and 2018 all cases ATAAD treated at Royal Brompton and Harefield NHS Foundation Trust were analysed. Patients were divided into two groups: (a) ascending aorta (interposition) graft (AAG) without valve replacement and (b) nonvalve-sparing aortic root replacement (ARR). Preoperative covariates were compared, as well as operative characteristics and postoperative complications. Long-term survival and echocardiographic outcomes were analysed using regression analysis.

RESULTS

In total, 116 patients were included: 63 patients in the AAG group and 53 patients in the ARR group. In patients where the native aortic valve was conserved, nine developed severe aortic regurgitation and two patients developed dilation of the aortic root requiring subsequent replacement during the follow-up period. Aortic regurgitation at presentation was not found to be associated with subsequent risk of developing severe aortic regurgitation or reintervention on the aortic valve. Overall mortality was observed to be significantly lower in patients undergoing AAG (17.5% vs. 41.5%, p = .004).

CONCLUSIONS

With careful patient selection, the native aortic root shows good long-term durability both in terms of valve competence and stable root dimensions after surgery for ATAAD. This study supports the consideration of conservation of the aortic valve during emergency surgery for type-A dissection, in the absence of a definitive indication for root replacement, including in cases where aortic regurgitation complicates the presentation.

Early and midterm results of valve-sparing aortic root reconstruction with a bovine pericardium patch for patients with acute type a aortic dissection

Objectives

We evaluated the feasibility, effectiveness, and safety of valve-sparing aortic root reconstruction with a bovine pericardium patch for patients with acute type A aortic dissection (ATAAD).

Methods

From January 2016 to January 2021, 895 consecutive patients with ATAAD received surgical treatment at our hospital. After applying our exclusion criteria, 508 patients were included in this research. Based on the attending surgeon's judgment and preference, 192 patients underwent our novel surgical novel surgical technique of valve-sparing aortic root reconstruction (repair group [RG]) and 316 patients underwent the Bentall procedure (Bentall group [BG]).

Results

In the RG, the early mortality rate was 4.2% (8/192). In the BG, the early mortality rate was 5.1% (16/316). There were no significant differences between groups. The incidence of postoperative renal failure in the BG was significantly higher than that in the RG. The mean follow-up time was 2.93 years (standard deviation, ±1.38 years). There were no significant differences between groups regarding ATAAD-related mortality and reoperation. In the RG, the rate of freedom from aortic root reoperation at 5 years was 98.2%, and the grade of aortic regurgitation 6 months later was significant less than that before surgery, and it did not worsen during later follow-up.

Conclusions

Valve-sparing aortic root reconstruction with a bovine pericardium patch can be successfully performed for selected patients with ATAAD and is associated with low in-hospital and late mortality rates and low root reoperation rates during early and midterm follow-up.

Distal Reoperations after Repair of Acute Type A Aortic Dissection-Incidence, Causes and Outcomes

Background and Aim of the Study

In patients with acute type A aortic dissection (A-AAD) whether initial repair should include also aortic arch replacement is still debated. We aimed to assess if extensive aortic repair prevents from reoperations patients with A-AAD.

Methods

Outcomes after distal reoperation following repair of A-AAD (n = 285; 1977 to 2018) were analysed in 22 of 226 who underwent ascending aorta/hemiarch replacement (Group 1 R ) and 7 of 59 who had ascending aorta/arch replacement (Group 2 R ).

Results

Distal reoperation was more common in Group 1 R (n = 22) than in Group 2 R (n = 0) (p < 0.001) while thoracic endovascular stenting was more frequent in Group 2 R (7 vs 3, p < 0.001). Indications for reoperation were pseudoaneurysm at distal anastomosis (n = 4, 18%) and progression of aortic dissection (n = 18, 82%) in Group 1 R . Indication for thoracic endovascular stenting was progressive aortic dissection in 3 patients of Group 1 R and in 6 of Group 2 R . Second reoperation was required in 2 patients from Group 1 R (2%) during a mean follow-up of 5 years. Median follow-up was 4 years in Group 1 R and 7 years in Group 2 R (p = 0.36). Hospital mortality was 14% in Group 1 R and 0% in Group 2 R (p = 0.3). Actuarial survival is 68 ± 10%, and 62 ± 11% for Group 1 R and 100% for Group 2 R at 5 and 10 years (p = 0.076).

Conclusions

Distal reoperations after A-AAD repair have an acceptable mortality. An extensive initial repair has lower rate of reoperation and better mid-term survival and should be indicated especially for young patients in experienced centers.

To repair or replace-the root dilemma in aortic dissections

Significant dilemma exists regarding the management of the aortic root pathology in acute aortic dissections. Several strategies for both repair and replacement exist and there is a lack of clarity on the superiority of one over the other. Important factors that influence management strategies include involvement of the sinuses, the competence of the aortic valve, the presence of Marfans syndrome, and connective tissue disorders, as well as availability of surgical expertise. The wide variability in these factors makes it unlikely for any one technique to be suitable for the management of all aortic roots pathology.

Hemiarch Versus Arch Replacement in Acute Type A Aortic Dissection: Is the Occam's Razor Principle Applicable?

BACKGROUND AND AIM OF THE STUDY

In patients with acute Type A aortic dissection (A-AAD) whether repair should be limited to ascending aorta/hemiarch replacement or extended to include the aortic arch is still debated. We have analyzed our experience to compare outcomes of patients with A-AAD treated with these 2 different surgical strategies.

METHODS

From 2006 to 2020, a total of 213 patients have undergone repair of A-AAD at our Center; in 163 of them ascending aorta/hemiarch replacement (Group 1) and in 75 ascending aorta and arch replacement (Group 2) were performed. The primary endpoint was early survival and secondary endpoints late survival, freedom from late complications and reoperations. Patients were compared according to era of operation: 2006 to 2013 (Era 1) and 2014 to 2020 (Era 2).

RESULTS

Overall hospital mortality was 12% and 5% in Group 1 and 2; mortality remained stable in Era 1 and 2 for Group 1 (15%), while it decreased from 8% to 1% in Group 2 patients (p = 0.24). Actuarial survival at 5 and 10 years is 72 ± 4% and 49 ± 5% in Group 1 and 77 ± 6% and 66 ± 9% in Group 2 (p = 0.073). Actuarial freedom from reoperation in the entire series is 94 ± 2% and 92 ± 3% at 5 and 10 years. Freedom from reoperation at 5 and 10 years is 92 ± 2% and 89 ± 3% in Group 1 and 98 ± 1% at all intervals in Group 2 (p = 0.068).

CONCLUSIONS

An aggressive approach to A-AAD provides superior long-term results without increasing mortality. Furthermore, arch replacement during A-AAD repair represents a more stable solution with lower incidence of late aortic-related complications. Immediate aortic arch replacement should be considered in the treatment of A-AAD especially in experienced centers.

Histological regional analysis of the aortic root and thoracic ascending aorta: a complete analysis of aneurysms from root to arch

Background

Although aortic root and ascending aortic aneurysms are treated the same, they differ in embryological development and pathological processes. This study examines the microscopic structural differences between aortic root and ascending aortic aneurysms, correlating these features to the macroscopic pathophysiological processes.

Methods

We obtained surgical samples from ascending aortic aneurysms (n = 11), aortic root aneurysms (n = 3), and non-aneurysmal patients (n = 7), Aortic collagen and elastin content were examined via histological analysis, and immunohistochemistry techniques used to determine collagen I, III, and IV subtypes. Analysis was via observational features, and colour deconvolution quantification techniques.

Results

Elastin fiber disruption and fragmentation was the most extensive in the proximal aneurysmal regions. Medial fibrosis and collagen density increased in proximal aneurysmal regions and aortic root aneurysms (p < 0.005). Collagen I was seen in highest quantity in aortic root aneurysms. Collagen I content was greatest in the sinus tissue regions compared to the valvular and ostial regions (p < 0.005) Collagen III and IV quantification did not vary greatly. The most susceptible regions to ultrastructural changes in disease are the proximal ascending aorta and aortic root.

Conclusions

The aortic root differs histologically from the ascending aorta confirming its unique composition in aneurysm pathology. These findings should prompt further evaluation on the influence of this altered structure on function which could potentially guide clinical management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01641-5.

Determinants of outcomes following surgery for type A acute aortic dissection: the UK National Adult Cardiac Surgical Audit

Aims 

Operability of type A acute aortic dissections (TAAAD) is currently based on non-standardized decision-making process, and it lacks a disease-specific risk evaluation model that can predict mortality. We investigated patient, intraoperative data, surgeon, and centre-related variables for patients who underwent TAAAD in the UK.

Methods and results

We identified 4203 patients undergoing TAAAD surgery in the UK (2009–18), who were enrolled into the UK National Adult Cardiac Surgical Audit dataset. The primary outcome was operative mortality. A multivariable logistic regression analysis was performed with fast backward elimination of variables and the bootstrap-based optimism-correction was adopted to assess model performance. Variation related to hospital or surgeon effects were quantified by a generalized mixed linear model and risk-adjusted funnel plots by displaying the individual standardized mortality ratio against expected deaths. Final variables retained in the model were: age [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.02–1.03; P < 0.001]; malperfusion (OR 1.79, 95% CI 1.51–2.12; P < 0.001); left ventricular ejection fraction (moderate: OR 1.40, 95% CI 1.14–1.71; P = 0.001; poor: OR 2.83, 95% CI 1.90–4.21; P < 0.001); previous cardiac surgery (OR 2.29, 95% CI 1.71–3.07; P < 0.001); preoperative mechanical ventilation (OR 2.76, 95% CI 2.00–3.80; P < 0.001); preoperative resuscitation (OR 3.36, 95% CI 1.14–9.87; P = 0.028); and concomitant coronary artery bypass grafting (OR 2.29, 95% CI 1.86–2.83; P < 0.001). We found a significant inverse relationship between surgeons but not centre annual volume with outcomes.

Conclusions 

Patient characteristics, intraoperative factors, cardiac centre, and high-volume surgeons are strong determinants of outcomes following TAAAD surgery. These findings may help refining clinical decision-making, supporting patient counselling and be used by policy makers for quality assurance and service provision improvement.

Distal Aortic Remodeling after Type A Dissection Repair: An Ongoing Mirage

Remodeling is a commonly encountered term in the field of cardiothoracic surgery that is often used to describe various pathophysiological changes in the dimension, structure, and function of various cardiac chambers, including the aorta. Stanford type A or DeBakey type 1 aortic dissection (TAAD) is a perplexing pathologic condition that can present surgical teams with the need to navigate a maze of complex decision-making. Ascending or hemi-arch replacement leaves behind a significant amount of distal diseased aortic tissue, which might have a persistent false lumen or primary or secondary intimal tears (or communications between lumina), which can lead to dilatation of the aortic arch. Unfavorable aortic remodeling is a major cause of distal aortic deterioration after the index surgery. Cardiac surgeons are aware of post-surgical cardiac chamber remodeling, but the concept of distal aortic remodeling is still idealized. The contemporary literature from established aortic centers supports aggressive management of the residual aortic pathology during the index surgery, and with continuing technical advancements, endovascular stenting options are readily available for patients with TAAD or for complicated type B aortic dissection cases. This review discusses the pathophysiology and treatment options for favorable distal aortic remodeling, as well as its impact on mid- to long-term outcomes following TAAD repair.

Survival after aortic root replacement with a stentless xenograft is determined by patient characteristics

OBJECTIVES

Our objective was to examine intermediate-term survival and reinterventions in unselected patients, stratified according to indication, who received a Freestyle (Medtronic Inc, Minneapolis, Minn) bioprosthesis as a full aortic root replacement.

METHODS

Data from medical records were retrospectively collected for patients who had aortic root replacement using Freestyle bioprostheses between 1999 and 2018 at 6 North-Atlantic centers. Survival status was extracted from national registries and results stratified according to indication for surgery.

RESULTS

We included 1030 implantations in 1008 patients with elective indications for surgery: aneurysm (39.8%), small root (8.3%), and other (13.8%), and urgent/emergent indications: endocarditis (26.7%) and Stanford type A aortic dissection (11.4%). Across indications, 46.3% were nonelective cases and 34.0% were reoperations. Median age was 66.0 (interquartile range, 58.0-71.8) years and median follow-up was 5.0 (interquartile range, 2.6-7.9) years. Thirty-day mortality varied from 2.9% to 27.4% depending on indication. Intermediate survival for 90-day survivors with elective indications were not different from the general population standardized for age and sex (P = .95, .83, and .16 for aneurysms, small roots, and other, respectively). In contrast, patients with endocarditis and type A dissection had excess mortality (P < .001). Freedom from valve reinterventions was 95.0% and 94.4% at 5 and 8 years, respectively. In all, 52 patients (5.2%) underwent reinterventions, most because of endocarditis.

CONCLUSIONS

At intermediate term follow-up this retrospective study provides further support for the use of the Freestyle bioprosthesis in the real-world setting of diverse, complex, and often high-risk aortic root replacement and suggests that outcome is determined by patient and disease, rather than by prosthesis, characteristics.

State of the Art Review: Surgical Treatment of Acute Type A Aortic Dissection

Acute type A aortic dissection (ATAAD) is a life-threatening event that requires immediate surgical treatment. Improvements in surgical treatment, graft technology, organ protection and imaging techniques have led to improved clinical outcomes. Individualized treatment concepts have emerged based on more advanced planning tools that allow for a tailored approach even in complex situations such as multi-level malperfusion. This review provides an overview of the current surgical treatment of ATAAD, focusing on new disease classifications, preoperative computed tomography angiography (CTA) assessment, new prosthesis and stent technologies, and organ-protection strategies.

The Role of Thoracic Endovascular Aortic Repair (TEVAR) of Thoracic Aortic Diseases in Patients with Connective Tissue Disorders - A Literature Review

OBJECTIVE

To review the currently available literature to define the role of thoracic endovascular aortic repair (TEVAR) in patients with connective tissue disorders (CTD).

METHODS

A comprehensive electronic database search was performed in PubMed, SCOPUS, Embase, Google scholar, and OVID to identify all the articles that reported on outcomes of utilizing TEVAR in patients with CTD during elective and emergency settings. The search was not limited to time or language of the published study.

RESULTS

All the relevant studies have been summarized in its correspondence section. The outcomes were analyzed in narrative format. The role of TEVAR has been elaborated as per each study. Currently, there is limited large cohort size studies outlining the use of TEVAR in patients with CTD. The use of endovascular repair in patients with CTD is limited due to progressive aortic dilatations and high possibility of further reinterventions at later stage of life.

CONCLUSION

Open repair remains the gold standard method of intervention in young patients with progressive CTD, especially in the setting of acute type A aortic dissection. However, TEVAR can be sought as a reliable alternative in emergency setting of diseases involving the descending thoracic aorta; yet the long-term data needs to be published to support such practice.

The functional limits of the aneurysmal aortic root. A unique pressure testing apparatus

BACKGROUND

The aortic root has unique embryological development and is a highly sophisticated and complex structure. In studies that report on the biomechanical characteristics of the thoracic aorta, distinction between the aortic root and ascending aorta regions is nonexistent. Our objective is to determine the maximal pressures at which dissection occurs or tissue failure occurs in the aortic root compared to that of the ascending aorta in the presence of aortic aneurysms. This may help guide preoperative monitoring, diagnosis and the decision for operative intervention for aortic root aneurysms in the normal and susceptible populations.

METHODS

We developed a simple aortic root and ascending aorta pressure testing unit in series. Ten fresh porcine hearts were obtained from the local abattoir (n = 5 aortic root and n = 5 ascending aorta for comparison). Using a saline filled needle and syringe, artificial fluid-filled aneurysms were created between the intima and medial layers of the aortic root. The aorta lumen was then progressively filled with saline solution. Pressure measurement was taken at time of loss of tissue integrity, obvious tissue dissection or aneurysm rupture, and the tissue structure was then visually examined.

RESULTS

In the aortic root, mean maximal pressure (mmHg) at tissue failure was 208 mmHg. Macroscopic examination revealed luminal tears around the coronary ostia in 2/5 specimens, and in all specimens, there was propagation of the dissection in the aortic root in a circumferential direction. In all ascending aorta specimens, the maximal aortic pressures exceeded 300 mmHg without tissue failure or dissection, and eventual apparatus failure.

CONCLUSION

Our results indicate that the aneurysmal aortic root tissues are at greater risk of rupture and dissection propagation at lower aortic pressure. With further analysis, this could guide clinical and surgical management.

Short- and long-term outcomes of aortic root repair and replacement in patients undergoing acute type A aortic dissection repair: Twenty-year experience

OBJECTIVE

The study objective was to evaluate the perioperative and long-term outcomes of aortic root repair and aortic root replacement and provide evidence for root management in acute type A aortic dissection.

METHODS

From 1996 to 2017, 491 patients underwent aortic root repair (n = 307) or aortic root replacement (n = 184) (62% bioprosthesis) for acute type A aortic dissection. Indications for aortic root replacement were intimal tear at the aortic root, root measuring 4.5 cm or more, connective tissue disease, or unrepairable aortic valvulopathy. Primary outcomes were in-hospital mortality, long-term survival, and reoperation rate for root pathology.

RESULTS

Patients' median age was 61 years and 56 years in the aortic root repair group and aortic root replacement group, respectively. The aortic root replacement group had more renal failure requiring dialysis, previous cardiac intervention or surgery, heart failure, coronary malperfusion syndrome, acute myocardial infarction, and severe aortic insufficiency, as well as concomitant coronary artery bypass grafting, tricuspid valve repair, and longer cardiopulmonary bypass and aortic crossclamp times but similar arch procedures. Perioperative outcomes were similar in the aortic root repair and aortic root replacement groups, including in-hospital mortality (8.5% and 8.2%), new-onset renal failure requiring permanent dialysis, stroke, myocardial infarction, and sepsis. Kaplan-Meier 10-year survival was 62% and 65%, and the 15-year cumulative incidence of reoperation was 11% and 7% in the aortic root repair and aortic root replacement groups, respectively. The primary indication for root reoperation was aortic root aneurysm in the aortic root repair group and bioprosthetic valve deterioration in the aortic root replacement group.

CONCLUSIONS

Aortic root repair and aortic root replacement are appropriate surgical options for acute type A aortic dissection repair with favorable short- and long-term outcomes. Aortic root replacement should be performed for patients with acute type A aortic dissection presenting with an intimal tear at the aortic root, root aneurysm 4.5 cm or greater, connective tissue disease, or unrepairable aortic valvulopathy.

A New Root-Strengthening Technique for Acute Aortic Dissection with a Weakened Aortic Root: The Neo-Adventitia Technique

Background

Dissection flaps in acute type A aortic dissection typically extend into the root, most frequently into the non-coronary sinus (NCS). The weakened root can be susceptible not only to surgical trauma, but also to future dilatation because of its thinner layers. Herein, we describe a new technique that we named the “neo-adventitia” technique to strengthen the weakened aortic root.

Methods

From 2012 to 2016, 27 patients with acute type A aortic dissection underwent supracommissural graft replacement using our neo-adventitia technique. After we applied biologic glue between the dissected layers, we wrapped the entire NCS and the partial left and right coronary sinuses on the outside using a rectangular Dacron tube graft that served as neo-adventitia to reinforce the dissected weakened wall. Then, fixation with subannular stitches stabilized the annulus of the NCS.

Results

There were 4 cases of operative mortality, but all survivors were discharged with aortic regurgitation (AR) classified as mild or less. Follow-up echocardiograms were performed in 10 patients. Of these, 9 showed mild or less AR, and 1 had moderate AR without root dilatation. There were no significant differences in the size of the aortic annulus (p=0.57) or root (p=0.10) between before discharge and the last follow-up echocardiograms, and no reoperations on the aortic roots were required during the follow-up period.

Conclusion

This technique is easy and efficient for reinforcing and stabilizing weakened roots. Furthermore, this technique may be an alternative for restoring and maintaining the geometry of the aortic root. An externally reinforced NCS could be expected to resist future dilatation.

Selective Aortic Arch and Root Replacement in Repair of Acute Type A Aortic Dissection

BACKGROUND

Controversy exists regarding the optimal extent of repair for type A aortic dissection. Our approach is to replace the ascending aorta, and only replace the aortic root or arch when intimal tears are present in those areas. We examined intermediate outcomes with this approach to acute type A aortic dissection repair.

METHODS

Between March 2005 and October 2016, 195 patients underwent repair of acute type A aortic dissection. Repair was categorized by site of proximal and distal anastomosis and extent of repair. Mean follow-up was 31.0 ± 30.9 months. Kaplan-Meier analysis was used to assess survival. Multiple variable Cox proportional hazards modeling was utilized to identify factors associated with overall mortality.

RESULTS

Overall survival was 85.1%, 83.9%, 79.1%, and 74.4% at 6, 12, 36, and 60 months, respectively. Eight patients required reintervention. The cumulative incidence of aortic reintervention at 1 year with death as a competing outcome was 3.95%. Multiple variable regression analysis identified factors such as age, preoperative renal failure, concomitant thoracic endograft, postoperative myocardial infarction and sepsis, and need for extracorporeal membrane oxygenation as predictive of overall mortality. Neither proximal or distal extent of repair, nor need for reintervention affected overall survival (proximal: hazard ratio 1.63, 95% confidence interval: 0.75 to 3.51, p = 0.22; distal: hazard ratio 1.12, 95% confidence interval: 0.43 to 2.97, p = 0.81; reintervention: hazard ratio 0.03, 95% confidence interval: 0.002 to 0.490, p < 0.01).

CONCLUSIONS

A selective approach to root and arch repair in acute type A aortic dissection is safe. If aortic reintervention is needed, survival does not appear to be affected.