Long-term outcomes of survival and freedom from reoperation on the aortic root or valve after surgery for acute ascending aorta dissection

Preservation versus replacement of the aortic root for acute type A aortic dissection

OBJECTIVE

To determine the impact of aortic root preservation versus aortic root replacement (ARR) after acute type A aortic dissection (ATAAD) repair.

METHODS

In this observational study of consecutive aortic surgeries between 2007 and 2021, patients with ATAAD were identified via a prospectively maintained institutional database and were stratified by root preservation versus ARR (including valve-sparing and complete ARR). Kaplan-Meier survival estimation and multivariable Cox regression analysis were performed.

RESULTS

Among the 601 patients underwent aortic arch reconstruction for ATAAD, 370 (61.6%) underwent root preservation and the other 231 (38.4%) underwent ARR, with a median follow-up of 6.3 years (interquartile range, 3.8-9.6 years). Cardiopulmonary bypass and ischemic times were longer in the ARR group, but intraoperative variables were otherwise similar between the groups, including cannulation strategy and extent of distal repair. There were no between-group differences in postoperative outcomes, including operative mortality, stroke, mechanical ventilation time, renal failure, reexploration for bleeding, and total length of stay. At a 1-year follow-up, the incidence of aortic regurgitation (moderate or greater) was similar in the 2 groups. On multivariable Cox regression, ARR was not associated with improved long-term survival compared with root preservation (hazard ratio, 1.13; 95% confidence interval, 0.82-1.56; P = .44). Late reinterventions on the aortic root or valve were similar in the 2 groups and was 2.0% for the overall cohort.

CONCLUSIONS

These findings suggest that aortic root preservation may achieve similar midterm outcomes as ARR after ATAAD repair.

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.

Imaging and Surveillance of Chronic Aortic Dissection: A Scientific Statement From the American Heart Association

All patients surviving an acute aortic dissection require continued lifelong surveillance of their diseased aorta. Late complications, driven predominantly by chronic false lumen degeneration and aneurysm formation, often require surgical, endovascular, or hybrid interventions to treat or prevent aortic rupture. Imaging plays a central role in the medical decision-making of patients with chronic aortic dissection. Accurate aortic diameter measurements and rigorous, systematic documentation of diameter changes over time with different imaging equipment and modalities pose a range of practical challenges in these complex patients. Currently, no guidelines or recommendations for imaging surveillance in patients with chronic aortic dissection exist. In this document, we present state-of-the-art imaging and measurement techniques for patients with chronic aortic dissection and clarify the need for standardized measurements and reporting for lifelong surveillance. We also examine the emerging role of imaging and computer simulations to predict aortic false lumen degeneration, remodeling, and biomechanical failure from morphological and hemodynamic features. These insights may improve risk stratification, individualize contemporary treatment options, and potentially aid in the conception of novel treatment strategies in the future.

Type A acute aortic dissection with ≥40-mm aortic root: results of conservative and replacement strategies at long-term follow-up

OBJECTIVES

We evaluated the long-term results of aortic root (AR) preservation and replacement in patients operated on for acute type A aortic dissection.

METHODS

Out of 302 patients discharged after repair of acute aortic dissection (1977-2019), 124 patients had an AR ≥40 mm, which was preserved in 84 (68%, group A) patients and replaced in 40 (32%, group B) patients. Group B patients were younger (mean age 57 ± 12 vs 62 ± 11 years, P = 0.07), with a mean AR of 47 vs 43 mm and ≥moderate aortic insufficiency in 65% vs 30%. Survival, causes of death and reoperations were analysed at mean follow-up of 9 ± 8 years (6 months to 40 years).

RESULTS

Actuarial survival of discharged patients at 5, 10 and 15 years was 97% (0.89-0.99), 78% (0.67-0.90) and 75% (0.64-0.88) in group A, and 85% (0.71-0.95), 62% (0.44-0.78) and 57% (0.39-0.76) in group B (log-rank test P = 0.2). Nine patients in group A (7 patients for aortic insufficiency and dilatation of the root and 2 patients for pseudoaneurysm) and 1 patient of group B (pseudoaneurysm of the right coronary button) required proximal reoperation without deaths. At 5, 10 and 15 years, the cumulative incidence of proximal aortic reoperations was 5%, 9% and 25% in group A, and 0%, 3% and 3% in group B (P = 0.02). At multivariable analysis AR >45 mm [hazard ratio (HR) 6.8, P = 0.026] and age (HR 0.9, P = 0.016) were independently associated with proximal reoperation.

CONCLUSIONS

AR preservation in acute type A dissection showed acceptable long-term outcomes. Nevertheless, a more aggressive approach appears a valid option, especially in patients with AR diameter >45 mm.

Effect of Aortic Valve Type on Patients Who Undergo Type A Aortic Dissection Repair

Aortic valve replacement (AVR) is common in the setting of type A aortic dissection (TAAD) repair. Here, we evaluated the association between prosthesis choice and patient outcomes in an international patient cohort. We reviewed data from the International Registry of Acute Aortic Dissection (IRAD) interventional cohort to examine the relationship between valve choice and short- and mid-term patient outcomes. Between January 1996 and March 2016, 1290 surgically treated patients with TAAD were entered into the IRAD interventional cohort. Of those, 364 patients undergoing TAAD repair underwent aortic valve replacement (AVR; mean age, 57 years). The mechanical valve cohort consisted of 189 patients, of which 151 (79.9%) had a root replacement. The nonmechanical valve cohort consisted of 5 patients who received homografts and 160 patients who received a biologic AVR, with a total of 118 (71.5%) patients who underwent root replacements. The mean follow-up time was 2.92 ± 1.75 years overall (2.46 ± 1.69 years for the mechanical valve cohort and 3.48 ± 1.8 years for the nonmechanical valve cohort). After propensity matching, Kaplan-Meier estimates of 4-year survival rates after surgery were 64.8% in the mechanical valve group compared with 74.7% in the nonmechanical valve group (p = 0.921). A stratified Cox model for 4-year mortality showed no difference in hazard between valve types after adjusting for the propensity score (p = 0.854). A biologic valve is a reasonable option in patients with TAAD who require AVR. Although this option avoids the potential risks of anticoagulation, long-term follow up is necessary to assess the effect of reoperations or transcatheter interventions for structural valve degeneration.

Fate of Preserved Aortic Root Following Acute Type A Aortic Dissection Repair

We examined the long-term fate of the preserved aortic root after emergent repair of acute Type A aortic dissection. 144 patients (60% males, mean age 60.5 years) underwent supracoronary ascending aortic replacement for acute Type A aortic dissection. Long-term survival, as well as growth, reoperation, and adverse events of the aortic root (rupture, pseudoaneurysm, and persistent dissection) were retrospectively assessed. Operative mortality was 9%, and overall survival at 1, 5, and 10 years was 87.8%, 76.4%, and 64.6%, respectively. Reoperation on the proximal aorta was performed in 16 patients (12.2%) within a median of 2.45 years post-operatively. Indications were severe aortic insufficiency (AI) (n = 6), aortic root pseudoaneurysm (n = 8), pseudoaneurysm with severe AI (n = 1), and persistent dissection with severe AI (n = 1). The aortic root grew at 0.2mm/year (interquartile range 0-0.8). Among survivors (n = 131), 28 patients (21.3%) reached aortic root diameter ≥ 45 mm (mean diameter 47.6 mm, range 45-54 mm). Survival free from proximal aortic reoperation at 1, 5, and 10 years was 96.6%, 94.5%, and 92.2%, respectively. No non-reoperated patient-despite persistent, unoperated enlargement or distortion or pseudoaneurysm of the aortic root-developed free rupture or fistula to a cardiac chamber. Root-sparing ascending aortic replacement for acute Type-A aortic dissection showed satisfactory long-term outcomes with relatively low rates of re-intervention or serious aortic root adverse events despite dilatation and irregularity of aortic root contour. Dense adhesions from prior surgery, proximal aortic suture line, and Teflon felt seem to discourage free rupture or fistulization.

Outcomes of Liu's aortic root repair and valve preservation in patients with type A dissection and aortic regurgitation

OBJECTIVES

To evaluate short- and medium-term outcomes following Liu's aortic root repair and valve preservation in patients with acute type A aortic dissection complicated by moderate-to-severe aortic regurgitation (AR).

METHODS

From October 2011 to July 2018, a total of 324 consecutive patients underwent emergency surgery for acute type A aortic dissection. There were 122 patients (38%) with moderate-to-severe AR, of whom 82 (67%) underwent Liu's aortic root repair and valve preservation. Aortic computed tomography angiography and echocardiography were performed at discharge, 6 and 12 months postoperatively, and annually thereafter. We focused on assessing the survival and aortic root and valve durability in the 82 patients.

RESULTS

The 30-day, 1-year, 3-year and 6-year survival estimates were 94%, 90%, 85% and 81%, respectively. At a median follow-up of 36.5 (interquartile range 24.9-50.9) months, all patients were free from reoperation. No residual false lumens in the aortic root, recurrent aortic root dissections or aortic root pseudoaneurysms were observed during the follow-up period. Only 1 patient (1%) presented with moderate AR at 6 months, which remained asymptomatic with no significant changes over a 3-year period. The remaining patients showed satisfactory valve function with an AR grade of mild (27%) or trace or none (72%). In the competing risk analysis, the incidence of recurrence of AR was 2% at 8 years.

CONCLUSIONS

Liu's aortic root repair and valve preservation is a safe and effective operative strategy that achieves favourable short- and medium-term outcomes for acute type A aortic dissection with moderate-to-severe AR.

A tailored strategy for repair of acute type A aortic dissection

OBJECTIVE

Innumerable surgical techniques are currently deployed for repairing acute type A aortic dissection (ATAAD). We analyzed our results using a conservative approach of root-sparing and hemiarch techniques in higher-risk patients and root and total arch replacement for lower-risk patients.

METHODS

We queried our aortic database for consecutive patients who underwent ATAAD repair. Patients who underwent conservative repair (group 1) were compared with those who underwent extensive repair (group 2) using univariable and multivariable analysis.

RESULTS

From 1997 to 2019, 343 patients underwent ATAAD repair. Two hundred forty had conservative repair (root-sparing, hemiarch) whereas 103 had extensive repair (root replacement and/or total arch). Group 1 was older with more comorbidities such as hypertension, previous myocardial infarction, and renal dysfunction. Group 2 had more connective tissue disease (2.1% vs 12.6%; P < .01), aortic insufficiency, and longer intraoperative times. The incidence of individual postoperative complications was similar regardless of approach. A composite of major adverse events (operative mortality, myocardial infarction, stroke, dialysis, or tracheostomy) was higher in the conservative group (15.1% vs 5.9%; P = .03). Operative mortality was 5.6% and not different between groups. Ten-year survival was similar with either surgical approach. Ten-year cumulative risk of reintervention was greater in group 2 (5.6% vs 21% at 10 years; P < .01). In multivariable analysis, ejection fraction and diabetes were predictors of major adverse events but not extensive approach. Extensive approach was a predictor of late reoperation (odds ratio, 3.03 [95% confidence interval, 1.29-7.2]; P = .01).

CONCLUSIONS

A tailored conservative approach to ATAAD leads to favorable operative outcomes without compromising durability.

Contemporary Surgical Strategies for Acute Type A Aortic Dissection

Surgical techniques and organ protection strategies for acute type A aortic dissection (ATAAD) have evolved considerably over the years. Nonetheless, open surgical repair remains a complex procedure, and there is a lack of consensus regarding many aspects of repair. In patients with dissection limited to the ascending aorta (DeBakey type II), repair typically involves replacement of only the affected segment, barring substantial aortic dilation to address elsewhere. In contrast, most patients with ATAAD have dissection extending into the thoracoabdominal aorta (DeBakey type I); in these cases, consideration must be given as to how much of the aortic arch and distal aorta to incorporate into the index repair, and several open and hybrid options exist. Herein, we review contemporary surgical strategies for ATAAD and clarify specific areas of controversy, in an effort to elucidate the optimal operative approach. In general, a limited index repair aimed at ensuring operative survival is typically the best option, whereas extended repair should be reserved for carefully selected patients who are most likely to benefit.

The fate of residual aortic regurgitation after ascending aorta replacement in type A aortic dissection

OBJECTIVE

This study aimed to evaluate the changes in postoperative aortic regurgitation (AR) and determine the predictors of significant AR and root reoperation after ascending aortic replacement (AAR) in patients with acute type A aortic dissection.

METHODS

From January 1995 to December 2017, 271 consecutive patients underwent valve/root-preserving AAR (n = 225) and root replacement (n = 46). AR grade trend over time was analyzed by the ordinal mixed-effects model. Significant AR was defined as AR grade ≥3+ during the follow-up period. Predischarge and follow-up echocardiograms were obtained in 95.6% and 88.8% of enrolled patients, respectively.

RESULTS

At predischarge, postoperative ≥2+ AR was present in 20 (9.3%) and 1 (2.3%) patients in the AAR and root replacement groups, respectively. With increasing time after surgery, the grade of AR increased. At 10 years, 4.6% of patients had developed 3+ or 4+ AR. Considering death as the competing risk, the 10-year cumulative incidence of significant AR was significantly higher in the AAR than in the root replacement group (12.3% vs 2.2%; P = .047). The risk of root reoperation at 10 years was not different between the groups (P = .118). On Cox analysis, preoperative ≥3+ AR (P = .002), postoperative ≥2+ AR (P = .040), and false to true lumen ratio (P = .005) were associated predictors of significant AR.

CONCLUSIONS

Although valve/root-preserving AAR demonstrated reasonable long-term outcomes when compared with root replacement, preoperative ≥3+ AR, postoperative ≥2+ AR, and high false to true lumen ratio significantly increased the risk of significant AR. Therefore, careful echocardiographic surveillance may be warranted in patients with postoperative ≥2+ AR and small true lumen.

Fate of the Preserved Sinuses of Valsalva After Emergency Repair for Acute Type A Aortic Dissection

BACKGROUND

Patients with acute type A aortic dissection (ATAAD) present with heterogeneous involvement of the aortic root complex. Despite this variation, the aortic root can usually be preserved the majority of the time by Teflon (WL Gore, Newark, DE) inlay patch reconstruction of the dissected sinuses of Valsalva (SOV). In this study, we report the long term anatomic, functional, and clinical outcomes associated with the preserved SOV after surgery for ATAAD.

METHODS

From 2002-2017, of 776 emergency ATAAD operations at a single institution, 558 (71.9%) underwent valve resuspension with SOV preservation. Echocardiography reports were reviewed to obtain postoperative SOV dimensions. Cumulative incidence of SOV dilation ≥ 4 5mm was calculated using the Fine-Gray method with death as a competing risk. Repeated-measures linear mixed effects model was used to determine risk factors for SOV growth over time.

RESULTS

During the follow-up period, 62 of 558 (11.1%) patients developed SOV diameter ≥ 45 mm. Cumulative incidence of SOV dilation ≥ 45 mm at 1, 5, and 10 years was 5.5%, 12.4%, and 18.9% respectively. In a multivariable Cox regression model, preoperative SOV diameter ≥ 45 mm was associated with a hazard ratio of 14.11 (95% confidence interval 7.03-31.62) for postoperative SOV dilation ≥ 45 mm. In a repeated-measures linear mixed effects model, preoperative and discharge SOV diameter were significant predictors of SOV dilation. Postoperative time course was also identified as significant indicating growth over time.

CONCLUSIONS

The preserved sinuses of Valsalva after surgery for ATAAD may be prone to progressive dilatation over time. Closer echocardiographic surveillance may be warranted in these patients.

Limited root repair in acute type A aortic dissection is safe but results in increased risk of reoperation

OBJECTIVE

Management of the aortic root is a challenge for surgeons treating acute type A aortic dissection.

METHODS

We performed a retrospective review of the acute type A aortic dissection experience at Stanford Hospital between 2005 and 2015 and identified patients who underwent either limited root repair or aortic root replacement. Differences in baseline characteristics were balanced with inverse probability weighting to estimate the average treatment effect on the controls. Weighted logistic regression was used to evaluate in-hospital mortality. Weighted Cox proportional hazards regression was used to evaluate differences in the hazard for mid-term death. Reoperation was evaluated with death as a competing risk with the Fine-Gray subdistribution hazard.

RESULTS

After we excluded patients managed either nonoperatively or with definitive endovascular repair, there were 293 patients without connective tissue disease who underwent either limited root repair or aortic root replacement. There was no difference in weighted perioperative mortality, odds ratio 0.89 (95% confidence interval [CI], 0.44-1.76, P = .7), and there was no difference in weighted survival, hazard ratio 1.12 (95% CI, 0.54-2.31, P = .8). Risk of reoperation was greater in limited root repair (11.8%, 95% CI, 0.0%-23.8%) than for root replacement (0%), P < .001.

CONCLUSIONS

Limited root repair was associated with increased risk of late reoperation after repair of acute type A aortic dissection. Surgeons with adequate experience may consider aortic root replacement in well-selected patients. However, given good outcomes after limited root repair, surgeons should not feel compelled to perform this more-complex operation.

Evolution of surgical therapy for Stanford acute type A aortic dissection

Acute type A aortic dissection (AcA-AoD) is a surgical emergency associated with very high morbidity and mortality. Unfortunately, the early outcome of emergency surgical repair has not improved substantially over the last 20 years. Many of the same debates occur repeatedly regarding operative extent and optimal conduct of the operation. The question remains: are patients suffering from too large an operation or too small? The pendulum favoring routine aortic valve resuspension, when feasible, has swung towards frequent aortic root replacement. This already aggressive approach is now being challenged with the even more extensive valve-sparing aortic root replacement (V-SARR) in selected patients. Distally, open replacement of most of the transverse arch is best in most patients. The need for late aortic re-intervention has not been shown to be affected by more extensive distal operative procedures, but the contemporary enthusiasm for a distal frozen elephant trunk (FET) only seems to build. It must be remembered that the first and foremost goal of the operation is to have an operative survivor; additional measures to reduce late morbidity are secondary aspirations. With increasing experience, true contraindications to emergency surgical operation have dwindled, but patients with advanced age, multiple comorbidities, and major neurological deficits do not fare well. The endovascular revolution, moreover, has spawned innovative options for modern practice, including ascending stent graft and adaptations of the old flap fenestration technique. Despite the increasingly complex operations and ever expanding therapies, this life-threatening disease remains a stubborn challenge for all cardiovascular surgeons. Development of specialized thoracic aortic teams and regionalization of care for patients with AcA-AoD offers the most promise to improve overall results.

Comparison of Left Ventricular Volume and Ejection Fraction and Frequency and Extent of Aortic Regurgitation After Operative Repair of Type A Aortic Dissection Among Three Different Surgical Techniques

Differences in recurrence rate of aortic regurgitation (AR) and extent of left ventricular (LV) remodeling across the different surgical options in patients operated for type A aortic dissection remain unknown. The present evaluation compared the AR recurrence rate and changes in LV volumes and systolic function in valve-sparing aorta replacement (VSAR), supracoronary ascending aorta replacement (SCAR), and aortic valve and aorta replacement (AVAR). A total of 97 patients (58 ± 12 years, 62% men) with acute type A aortic dissection who underwent VSAR (n = 24), SCAR (n = 43), or AVAR (n = 30) were evaluated. Changes in LV volumes and function between postoperative and follow-up were compared using linear mixed models. Postoperative AR grades were not significantly different between groups. However, after median follow-up of 47 months, AR grade ≥2 was significantly more often observed in SCAR (55%) and VSAR (25%) compared to AVAR (0%, p <0.001). LV volumes remained stable in VSAR and AVAR but increased significantly in SCAR (LV end-diastolic volume: from 99 ± 4 to 131 ± 6 ml; p <0.001; LV end-systolic volume: from 49 ± 3 to 66 ± 5 ml; p = 0.002). In patients with recurrent AR grade ≥2 at follow-up, LV volumes increased, whereas patients without recurrent AR did not show significant LV dilatation. In conclusion, patients with acute type A aortic dissection who underwent SCAR or VSAR showed more frequently AR grade ≥2 recurrence compared to AVAR. However, only patients who underwent SCAR experienced adverse LV remodeling at follow-up. Recurrence of AR grade ≥2 was associated with adverse LV remodeling.

Surgical Strategy and Outcome for Aortic Root in Patients Undergoing Repair of Acute Type A Aortic Dissection

BACKGROUND

This study evaluated the relevance of our indication of aortic root operations for acute type A aortic dissection and compared early and long-term outcomes of emergency type A aortic dissection operations between patients who underwent aortic root operations and those who did not.

METHODS

We retrospectively reviewed 316 consecutive patients who underwent emergency aortic operations for acute type A aortic dissection between January 2009 and September 2013. We performed simultaneous aortic root operations when the aortic root diameter was greater than 45 mm or an intimal tear was present in the aortic root, or both. After this indication, we performed aortic repair involving the aortic root in 40 patients (aortic root replacement [ARR] group, 12.7%) and not involving the aortic root in 276 patients (non-ARR group, 87.3%). We analyzed early and long-term outcomes, including late aortic root events.

RESULTS

In-hospital mortality was 12.5% (5 of 40) in the ARR group and 4.7% (13 of 276) in non-ARR group (p = 0.05). Overall survival at 3 and 5 years was 84.8% and 84.8%, respectively in ARR group and was 91.9% and 91.9%, respectively, in the non-ARR group (p = 0.078). Late aortic root events, defined as aortic root dilatation (≥ 3 mm/y), reoperation of the aortic root, aortic regurgitation (moderate or higher), and pseudoaneurysm, were observed in no patients in the ARR group and in 32 patients (11.6%) in the non-ARR group (p = 0.029). In the non-AAR group, dissection of 2 or more aortic sinuses was the only independent predictor of a late aortic root event (hazard ratio, 2.20; 95% confidence interval, 1.08 to 4.61; p = 0.03).

CONCLUSIONS

Simultaneous aortic root operations significantly reduced the incidence of late aortic root events. The dissection of 2 or more sinuses of Valsalva was associated with a late aortic root event in patients who did not undergo aortic root operations.

Italian multicentre study on type A acute aortic dissection: a 33-year follow-up†

OBJECTIVES

Despite substantial progress in surgical techniques and perioperative management, the treatment and long-term follow-up of type A acute aortic dissection (AAD) still remain a major challenge. The objective of this retrospective, multicentre study was to assess in a large series of patients the early and long-term results after surgery for type A AAD.

METHODS

We analysed the preoperative, intraoperative and postoperative conditions of 1.148 consecutive patients surgically treated in seven large referral centres from 1981 to 2013. We applied to each patient three different multi-parameter risk profiles (preadmission risk, admission risk and post-surgery risk) in order to compare risk factors and outcome. Long-term Kaplan-Meier survival was evaluated.

RESULTS

The median age was 64 years and the male population was predominant (66%). Identified diagnosis of collagen disease was present in 9%, and Marfan syndrome in 5%. Bicuspid aortic valve was present in 69 patients (6%). Previous cardiac surgery was identified in 10% of the patients. During surgery, the native aortic valve was preserved in 72% of the cases, including leaflet resuspension in 23% and David operation in 1.2%. Considering aortic valve replacement (AVR: 28%), bioprosthesis implantation was performed in 14.7% of the subjects. Neurological impairment at discharge was shown in 23% of the cases among which 21% of patients had new neurological impairment versus preoperative conditions. The overall 30-day mortality rate was 25.7%. All risk profiles remained independently associated with in-hospital mortality. During the available follow-up of hospital survivors (median: 70 months, interquartile range: 34-113, maximum: 396), cardiac-related death occurred in 7.9% of the subjects. The cumulative survival rate for cardiac death was 95.3% at 5 years, 92.8% at 10 years and 52.8% at 20 years. Severe aortic regurgitation (AR) (grade 3-4) at the time of surgery showed to be a significant risk factor for reintervention during the follow-up (P < 0.001). Among risk profiles, only the preadmission risk was independently associated with late mortality after multivariate analysis. Unexpectedly, there was no difference in freedom from cardiac death between patients with and without AVR.

CONCLUSIONS

Although surgery for type A has remained challenging over more than three decades, there is a positive trend in terms of hospital mortality and long-term follow-up. About 90% of patients were free from reoperation in the long term, although late AR remains a critical issue, suggesting that a thorough debate on surgical options, assessment and results of a conservative approach should be considered.