Aortic Root Surgery: Does High Surgical Volume and a Consistent Perioperative Approach Improve Outcome?

Adverse Technical Events During Aortic Root Replacement

BACKGROUND

Although adverse technical events during aortic root replacement (ARR) are not uncommon and are extremely challenging, there is scant literature to help surgeons prepare for such situations. We describe our experience of outstanding technical events during ARR.

METHODS

This is a retrospective study of 830 consecutive ARRs at a single center from 2012 to 2022. Technical events were defined as intraoperative events that led to an unplanned cardiac procedure, need for mechanical circulatory support, or additional aortic cross-clamping. Logistic regression identified factors associated with operative mortality and technical events.

RESULTS

Technical events occurred in 90 patients (10.8%) and were attributed to bleeding (n = 26), nonischemic ventricular dysfunction (n = 23), residual valve disease (n = 20), myocardial ischemia (n = 19), and iatrogenic dissection (n = 2). Prior sternotomy (odds ratio [OR], 2.38; 95% CI, 1.36-4.19; P = .002) and complex aortic valve disease (OR, 3.09; 95% CI, 1.09-8.75; P = .03) were associated with technical events. Patients with technical events had higher rates of operative mortality (6.7% vs 2.3%, P = .03) and all major postoperative complications. Surgical indications of dissection (OR, 13.57; 95% CI, 4.95-37.23; P < .001) and complex aortic valve disease (OR, 14.09; 95% CI, 3.67-54.02; P < .001) but not adverse technical events (OR, 2.42; 95% CI, 0.81-7.26; P = .11) were associated with operative mortality.

CONCLUSIONS

Adverse technical events occurred in 10.8% of ARRs and were associated with reoperative sternotomies. Technical events are associated with increased postoperative complications.

Importance of surgeon's experience in practicing valve-sparing aortic root replacement

Background

Valve-sparing root replacement (VSRR) requires a unique skill set. This study aimed to examine the influence of surgeon's procedural volume on outcomes of VSRR.

Methods

This retrospective study included 1697 patients from 2 large, high-volume aortic centers who underwent aortic root replacement (ARR) between 2004 and 2021 and were potentially eligible for VSRR. Surgeons were classified as performing <5 ARRs or ≥5 ARRs annually. Multivariable logistic regression was used to examine the independent association of surgeon volume and the decision to perform VSRR. Inverse probability treatment weighting (IPTW) was used to match patients who were operated on by <5 ARR surgeons or ≥5 ARR surgeons and compare long-term survival probability. Cumulative incidence curves with mortality as a competing risk were plotted to compare the rate of aortic valve reoperation.

Results

Of 1697 patients who met the study inclusion criteria, 944 underwent composite-valve conduit ARR and 753 underwent VSRR. The median age of the cohort was 57 years (interquartile range, 45-66 years), and 268 (15.8%) were female. Aortic insufficiency was present in 1105 patients (65.1%), and 200 of the procedures (11.8%) were reoperations. The indication for surgery was aneurysm in 1496 patients (88.2%) and dissection in 201 (11.8%). Among the 743 patients who underwent VSRR, 691 (92%) were operated on by ≥ 5 ARR surgeons and 62 (8%) were operated on by <5 ARR surgeons. In multivariable logistic regression, ≥5 ARRs (odds ratio, 3.33; 95% confidence interval, 2.34-4.73; P < .001) was associated with VSRR as the procedure of choice. Following IPTW, there was no significant difference between <5 ARR and ≥5 ARR surgeons in survival probability after VSRR (P = .59) or in the rate of aortic valve reoperation (P = .60).

Conclusions

In the setting of a high-volume aortic center, patients who undergo ARR are less likely to receive VSRR if operated on by a <5 ARR surgeon; however, VSRR may be safely performed by <5 ARR surgeons.

The Year in Aortic Surgery: Selected Highlights From 2023

This article reviews the recent and relevant literature to the field of aortic surgery. Specific areas highlighted include outcomes of Stanford type A dissection, management of acute aortic syndromes, management of aortic aneurysms, and traumatic aortic injury. Although the focus was on articles from 2023, literature from prior years also was included, given that this article is the first of a series. Notably, the pertinent sections from the 2022 American College of Cardiology/American Heart Association Guidelines for the Diagnosis and Management Aortic Disease are discussed.

The impact of reoperative surgery on aortic root replacement in the United States

OBJECTIVE

Reoperative sternotomy is associated with poor outcomes after cardiac surgery. We aimed to investigate the impact of reoperative sternotomy on the outcomes after aortic root replacement.

METHODS

All patients who underwent aortic root replacement from January 2011 to June 2020 were identified using the Society of Thoracic Surgeons Adult Cardiac Surgery Database. We compared outcomes between patients who underwent first-time aortic root replacement with those with a history of sternotomy undergoing reoperative sternotomy aortic root replacement using propensity score matching. Subgroup analysis was performed among the reoperative sternotomy aortic root replacement group.

RESULTS

A total of 56,447 patients underwent aortic root replacement. Among them, 14,935 (26.5%) underwent reoperative sternotomy aortic root replacement. The annual incidence of reoperative sternotomy aortic root replacement increased from 542 in 2011 to 2300 in 2019. Aneurysm and dissection were more frequently observed in the first-time aortic root replacement group, whereas infective endocarditis was more common in the reoperative sternotomy aortic root replacement group. Propensity score matching yielded 9568 pairs in each group. Cardiopulmonary bypass time was longer in the reoperative sternotomy aortic root replacement group (215 vs 179 minutes, standardized mean difference = 0.43). Operative mortality was higher in the reoperative sternotomy aortic root replacement group (10.8% vs 6.2%, standardized mean difference = 0.17). In the subgroup analysis, logistic regression demonstrated that individual patient repetition of (second or more resternotomy) surgery and annual institutional volume of aortic root replacement were independently associated with operative mortality.

CONCLUSIONS

The incidence of reoperative sternotomy aortic root replacement might have increased over time. Reoperative sternotomy is a significant risk factor for morbidity and mortality in aortic root replacement. Referral to high-volume aortic centers should be considered in patients undergoing reoperative sternotomy aortic root replacement.

Hemiarch versus extended arch repair for acute type A dissection: Results from a multicenter national registry

OBJECTIVE

We compared perioperative outcomes of patients with acute type A aortic dissection undergoing hemiarch (HA) versus extended arch (EA) repair with or without descending aortic intervention.

METHODS

Nine hundred twenty-nine patients underwent acute type A aortic dissection repair (2002-2021, 9 centers) including open distal repair (HA) with or without additional EA repair. EA with intervention on the descending aorta (EAD) included elephant trunk, antegrade thoracic endovascular aortic replacement, or uncovered dissection stent. EA with no descending intervention (EAND), included unstented suture-only methods. Primary outcomes were in-hospital mortality, permanent neurologic deficit, computed tomography malperfusion resolution, and a composite. Multivariable logistic regression was also performed.

RESULTS

Mean age was 66 ± 18 years, 30% (278 out of 929) were women, and HA was performed more frequently (75% [n = 695]) than EA (25% [n = 234]). EAD techniques included: dissection stent (39 out of 234 [17%]), thoracic endovascular aortic replacement (18 out of 234 [7.7%]), and elephant trunk (87 out of 234 [37%]). In-hospital mortality (EA: n = 49 [21%] and HA: n = 129 [19%]; P = .42), and neurological deficit (EA: n = 43 [18%] and HA: n = 121 [17%]; P = .74) were similar. EA was not independently associated with death (EA vs HA odds ratio, 1.09; 95% CI, 0.77-1.54; P = .63) or neurologic deficit (EA vs HA odds ratio, 0.85; 95% CI, 0.47-1.55; P = .59). Composite adverse events differed significantly (EA vs HA odds ratio, 1.47; 95% CI, 1.16-1.87; P = .001). Malperfusion resolved more frequently after EAD (EAD: n = 32 [80%], EAND: n = 18 [56%], HA: n = 71 [50%]; P = .004), although multivariable analysis was not significant (EAD vs HA odds ratio, 2.17; 95% CI, 0.83-5.66; P = .10).

CONCLUSIONS

Extended arch interventions pose similar perioperative mortality and neurologic risks as Hemiarch. Descending aortic reinforcement may promote malperfusion restoration. Extended techniques should be approached with caution in acute dissection due to increased risk of adverse events.

Natural history of moderate aortic stenosis and predictors for mortality: Systematic review and Meta-analysis

Although the current guidelines advocate imaging surveillance for moderate aortic stenosis (AS), recent studies suggest a worse prognosis associated with moderate AS than previously reported. Considering the recent paradigm shift in AS management, the risk/benefit profile of aortic valve replacement (AVR) for moderate AS needs to be re-evaluated. Herein, we conducted meta-analyses of natural history and risk predictors in patients with moderate AS. PubMed and EMBASE were searched through May 2022 to identify studies that investigated the natural history of patients with moderate AS. Meta-analyses with random effects model were conducted. Our analysis included 20 observational studies which enrolled a total of 11,114 patients with moderate AS. The rate of all-cause death was 11.0 [95 % confidence interval (CI), 7.6-14.4] per 100 patients per year. Surgical or transcatheter AVR occurred at a rate of 8.5 (95 % CI, 6.2-10.8; I², 98.9 %) per 100 patients per year. Occurrence of AVR during follow-up [hazard ratio (HR) (95 % CI) =0.56 (0.42-0.75), p < 0.001] and early AVR for moderate AS [HR (95 % CI) = 0.47 (0.25-0.90), p = 0.02] were associated with significantly lower all-cause mortality, while left ventricular ejection fraction <50 % [HR (95 % CI) =1.84 (1.33-2.57), p = 0.0003] and symptomatic status [HR (95 % CI) = 1.52 (1.32-1.75), p < 0.0001] were associated with increased all-cause mortality. Sex difference was not related to all-cause mortality. Our meta-analysis suggested that moderate AS was associated with high mortality, especially in low left ventricular systolic function or symptomatic patients. In addition, significant portion of the patients underwent AVR during follow-up.

Early and long-term outcomes of conventional and valve-sparing aortic root replacement

OBJECTIVE

To determine the early and long-term outcomes of conventional aortic root (ARR) and valve-sparing root replacement (VSRR) using a standard perioperative and operative approach.

METHODS

We present prospectively collected data of 609 consecutive patients undergoing elective and urgent aortic root surgery (470 ARR, 139 VSRR) between 2006 and 2020. Primary outcomes were operative mortality and incidence of postoperative complications. Secondary outcomes were long-term survival and requirement for reintervention. Median follow-up was 7.6 years (range 0.5-14.5).

RESULTS

189 patients (31%) had bicuspid aortic valves and 17 (6.9%) underwent redo procedures. Median cross-clamp time was 88 (range 54-208) min with cardiopulmonary bypass of 108 (range 75-296) min. In-hospital mortality was 10 (1.6%), with transient ischaemic attacks/strokes occurring in 1.1%. In-hospital mortality for VSRR was 0.7%. 12 patients (2.0%) required a resternotomy for bleeding and 14 (2.3%) received haemofiltration. Intensive care unit and hospital stay were 1.7 and 7.0 days, respectively. During follow-up, redo surgery for native aortic valve replacement was required in 1.4% of the VSRR group. Overall survival was 95.1% at 3 years, 93.1% at 5 years, 91.2% at 7 years and 88.6% at 10 years.

CONCLUSIONS

ARR and VSRR can be performed with low mortality and morbidity as well as a low rate of reintervention during the period of long-term follow-up, if performed by an experienced team with a consistent perioperative approach. This series provides contemporary evidence to balance the risks of aortic aneurysms and their rupture at diameters of <5.5 cm against the risks and benefits of surgery.

Transfusion in Root Replacement for Aortic Dissection: STS Adult Cardiac Surgery Database Analysis

BACKGROUND

Transfusion in acute aortic syndromes has been studied in a limited fashion. We sought to describe contemporary transfusion practice for root replacement in acute (Stanford) type A aortic dissection (ATAAD).

METHODS

The STS Adult Cardiac Surgery Database was interrogated to identify patients who underwent primary aortic root replacement for ATAAD (July 2014 - June 2017). Patients (n = 1558) were stratified by type of root replacement. Multivariate regression was used to determine those variables associated with transfusion and postoperative morbidity.

RESULTS

Transfusion was required in 90.5% of cases (n = 1410). Operative mortality for all patients was 17.3% (261 deaths). Intraoperative red blood cell (RBC) transfusion portended reduced short-term survival (odds ratio {OR} 2.00, p = 0.025). Massive postoperative transfusion was associated with prolonged ventilation (OR 13.47, p < 0.001), sepsis (OR 4.13, p < 0.001), and new dialysis-dependent renal-failure (OR 2.43, p < 0.001). Females were more likely to require transfusion (OR 3.03, p < 0.001), as were patients who had coronary bypass (OR 1.57, p = 0.009), and those in shock (OR 2.27, p < 0.001). Valve-sparing aortic root replacement (VSARR) was associated with reduced transfusion requirements vs. composite roots. Institutional case volume was not appreciably correlated with transfusion.

CONCLUSIONS

Most patients undergoing root replacement for aortic dissection require blood products. Composite root replacement is associated with a greater likelihood of transfusion than a valve-sparing operation. Transfusion independently foreshadows greater operative mortality.

Acute Type A Aortic Dissection Repair After Hours: Does It Influence Outcomes?

BACKGROUND

Time of day has been associated with adverse outcomes in certain surgical pathologies. Because acute type A aortic dissection typically mandates immediate repair, relatively little attention has been paid to the potential impact of the day-night timing of the operation itself. We sought to determine whether patients with acute dissection treated during typical working hours demonstrated a difference in outcomes compared with those who required surgery after hours.

METHODS

We undertook a comprehensive review of our prospectively collected database from July 2014 to October 2018. A total of 164 consecutive patients underwent primary repair of an acute type A dissection. Based on the procedure start time, patients were divided into 2 groups: working hours (7 am to 4 pm, Monday to Friday; n = 60), and after hours (all other times, including weekends and holidays; n = 104). We propensity-matched 58 pairs of patients and analyzed perioperative data and short-term clinical outcomes.

RESULTS

Thirty-day mortality for all 164 patients was 10.4% (17 deaths), which was not significantly different between the matched groups (working-hours: 8 deaths [13.8%] versus after hours: 4 deaths [6.9%]; P = .36). Perfusion, cross-clamp, and circulatory arrest times did not differ between groups, nor did the types of aortic repairs performed. Postoperative complications were also comparable, including stroke, reoperation for bleeding, and new-onset renal failure requiring dialysis.

CONCLUSIONS

Thirty-day mortality and major morbidity after acute type A dissection repair are independent of when the operation is performed. Expeditious surgical intervention is recommended for all primary acute type A dissection, irrespective of time of day.

Does the Aortic Annulus Dilate After Aortic Root Remodeling?

BACKGROUND

The 2 main techniques of valve-sparing aortic root replacement (VSRR) are remodeling and reimplantation. There is concern that the aortic annulus, which is not stabilized in remodeling technique, may dilate over time and cause aortic regurgitation. Our aim was to assess whether the aortic annulus dilates after VSRR with remodeling technique without aortic annuloplasty.

METHODS

Data on patients undergoing elective or urgent VSRR remodeling technique between 2005 and 2018 were collected. Patients undergoing arch and emergency surgery for acute type A aortic dissection were excluded. Preoperative aortic annulus diameter was measured by transthoracic echocardiography, and this was compared with the annulus diameter measured from the most recently available transthoracic echocardiography. The requirement for reintervention during follow-up was recorded.

RESULTS

Between 2005 and 2018, 98 patients underwent VSRR. Sixty-six (67.3%) had Marfan syndrome or Loeys-Dietz syndrome. Median age was 60 (interquartile range, 18-68) years and 71 (72.4%) were men. Median cross-clamp and cardiopulmonary bypass times were 122 (interquartile range, 104-164) minutes and 138 (interquartile range, 121-198) minutes, respectively. Median intensive care unit and hospital stay were 1 day and 6 days, respectively. No patients suffered perioperative stroke. There was no in-hospital mortality. At median follow-up of 7.1 years (interquartile range, 5-129 months), mean postoperative annular diameter was 25.7 mm, from 24.2 mm preoperatively (P = .403). One patient required aortic valve replacement during follow-up. Freedom from moderate or severe aortic regurgitation was 97%.

CONCLUSIONS

There was no significant aortic annular dilatation in selected patients undergoing remodeling VSRR. Our data do not support routine use of annuloplasty in patients with annular diameter less than or equal to 25 mm.