Distal aortic interventions after repair of ascending dissection: The argument for a more aggressive approach

Frozen elephant use in type a dissection: fundamentals, innovations, and pitfalls

INTRODUCTION

Type A acute aortic dissection (TA-AAD) is a great challenge for aortic surgeons. The establishment of a standardized surgical approach, particularly the determination of whether and when to address the aortic arch and the distal aorta in the same operation as the proximal aorta, is still unclear.

AREAS COVERED

Frozen elephant trunk (FET) has emerged as a valuable treatment for TA-AAD over the last decade. Here, we discuss the fundamentals and pitfalls of frozen elephant trunk procedures and present the latest innovations.

EXPERT OPINION

FET has the potential to simplify arch reconstruction in patients with complex arch tears and rupture, optimize perfusion in the distal true lumen for those with a compressed true lumen and malperfusion, address distal reentry tears, and promote false lumen thrombosis and late aortic remodeling. Nevertheless, FET is still associated with non-negligible mortality and morbidity rates. Patient selection, surgical expertise, and postoperative care remain crucial determinants in ensuring successful outcomes. Recent innovations in FET surgery involve the development of techniques to minimize or avoid hypothermic circulatory arrest and new FET devices with different arch branch configurations aiming to facilitate subsequent aortic reinterventions. We believe that both these advancements have the potential to improve patient outcomes.

Three-year outcomes of the Dissected Aorta Repair Through Stent Implantation trial

OBJECTIVE

The study objective was to evaluate the clinical and radiographic outcomes of the Ascyrus Medical Dissection Stent in a prospective, nonrandomized, international study (Dissected Aorta Repair Through Stent Implantation) of patients with acute DeBakey type I aortic dissection.

METHODS

The Ascyrus Medical Dissection Stent was used in combination with the standard surgical management of acute DeBakey type I aortic dissection I to treat patients with (56.5%, 26/46) and without (43.5%, 20/46) preoperative clinical and radiographic malperfusion. All patients had a primary entry tear in the ascending aorta, and 97.8% (45/46) were treated with a hemiarch repair. Median follow-up was 3 years.

RESULTS

All 47 patients underwent emergency surgical repair with successful Ascyrus Medical Dissection Stent implantation. One patient was excluded from analysis due to use in iatrogenic dissection. Overall mortality at 30 days and 3 years was 13.0% (6/46) and 21.7% (10/46), respectively. Overall new stroke rate at 30 days was 15.2% (7/46). No devices were explanted at any time during the 3-year median follow-up. At 3 years, the total aortic diameter in zones 0, 1, and 2 decreased or remained stable in 91.7%, 72.7%, and 75.0%, respectively. The false lumen was completely or partially thrombosed in 90.5% in zone 0, 60.0% in zone 1, and 68.2% in zone 2 at 3 years.

CONCLUSIONS

The use of the Ascyrus Medical Dissection Stent in the treatment of acute DeBakey type I aortic dissection I holds promise as a simple technology that enables repair of the aortic arch and proximal descending aorta, while promoting positive aortic remodeling. Ongoing follow-up of the Dissected Aorta Repair Through Stent Implantation trial will provide long-term, prospective, clinical outcomes and radiographic data on positive remodeling of the aortic arch.

Reinterventions After Repair of Acute Type A Aortic Dissection: Incidence, Outcomes, and Risk Factors

BACKGROUND

This study reports the incidence, outcomes, and risk factors for aortic reinterventions after repair of acute type A aortic dissection (ATAAD).

METHODS

This was an observational study of aortic operations from 2010 to 2021. All patients with ATAAD undergoing open aortic arch reconstruction were included. Patients were dichotomized by the need for reintervention, which included reinterventions proximal to or distal to the index aortic repair. Propensity matching was used to determine the impact of reintervention on long-term outcomes. The cumulative incidence function for reintervention was estimated, and multivariable Fine-Gray analysis was performed to identify variables associated with reintervention, with death treated as a competing event.

RESULTS

We identified 601 patients undergoing surgery for ATAAD. An aortic reintervention was required in 71 (11.8%), comprising a proximal reintervention in 12 patients, a distal reintervention in 56, and both in 3. The cumulative incidence of reintervention was 11.6% (95% CI, 8.9%-14.6%) at 5 years and was 16.0% (95% CI, 12.2%-20.3%) at 10 years, with a median time to reintervention of 4.0 years (interquartile range, 0.9-7.5 years). Multivariable analysis using the Fine-Gray method showed no operative variables were associated with reinterventions. Among the 71 reinterventions, there were 4 (5.6%) operative deaths. After propensity matching, there was no difference in Kaplan-Meier survival estimates across each group (P = .138 by log-rank statistics).

CONCLUSIONS

The cumulative incidence of aortic reintervention after ATAAD repair was reasonably low (16% at 10 years), reinterventions were relatively safe (6% operative mortality), and reinterventions did not significantly impact long-term survival.

Aortic elastic fiber degeneration during acute type a aortic dissection and reverse aortic remodeling

BACKGROUND

Progression of proximal or distal aortic dilatation is defined as reverse aortic remodeling after surgery for acute type A aortic dissection (ATAAD) that may be dependent on aortic wall degeneration.

METHODS

We investigated whether aortic wall degeneration is associated with reverse aortic remodeling leading to aortic reoperation after surgery for ATAAD. Altogether, 141 consecutive patients undergoing surgery for ATAAD at Tampere were evaluated. The resected ascending aortic wall at surgery was processed for 42 degenerative, atherosclerotic and inflammatory histological variables. Patients undergoing aortic reoperations (Redos) were compared with those without aortic reoperations (Controls) during a mean 4.9-year follow-up.

RESULTS

Redos were younger than Controls (56 and 66 years, respectively, P < 0.001), and had less frequently previous cardiac surgery prior to ATAAD. Initial surgery encompassed replacement of the ascending aorta in the majority. There were 21 Redos in which one patient died during follow-up as compared with 51 deaths in Controls (log Rank P = 0.002). Histology of the aortic wall revealed increased elastic fiber fragmentation, loss, and disorganization in Redos as compared with Controls (2.1 ± 0.5 vs. 1.9 ± 0.5, Point score unit (PSU), P = 0.043 and 1.7 ± 0.8 vs. 1.2 ± 0.8, PSU, P = 0.016, respectively). Moderate atherosclerosis occurred less often in Redos vs. Controls (9.5% vs. 33%, PSU, P = 0.037, respectively).

CONCLUSIONS

According to this exploratory study, histopathology reveals distinctive aortic wall degeneration during ATAAD. Reverse aortic remodeling after ATAAD is associated with the presence of ascending aortic wall elastic fiber fragmentation, loss and disorganization during ATAAD.

Zone 2 arch repair for acute type A dissection: Evolution from arch-first to proximal-first repair

Objective

With growing experience of acute type A aortic dissection repair, Zone 2 arch repair has been advocated. The aim of this study is to compare the outcome between "proximal-first" and "arch-first" Zone 2 repair.

Methods

From January 2015 to March 2023, 45 patients underwent Zone 2 arch repair out of 208 acute type A aortic dissection repairs: arch-first, N = 19, and proximal-first technique, N = 26, since January 2021. Indications were aortic arch or descending tear, complex dissection in neck vessels, cerebral malperfusion, or aneurysm of the aortic arch.

Results

The lowest bladder temperature was higher in the proximal-first technique (24.9 °C vs 19.7 °C, P < .001). Cardiopulmonary bypass (230 vs 177.5 minutes, P < .001), myocardial ischemic (124 vs 91 minutes, P < .001), and lower-body circulatory arrest (87 vs 28 minutes, P < .001) times were shorter in the proximal-first technique. The arch-first group required more packed red blood cells (arch-first, 2 units vs proximal-first, 0 units, P = .048), platelets (arch-first, 4 units vs proximal-first, 2 units, P = .003), and cryoprecipitates (arch-first, 2 units vs proximal-first, 1 unit, P = .024). Operative mortality and major morbidities were higher in the arch-first group (57.9% vs 11.5%, P = .001). One-year survival was comparable (arch-first, 89.5% ± 7.0% vs proximal-first, 92.0% ± 5.5%, P = .739). Distal intervention was successfully performed in 5 patients (endovascular, N = 3, and open repair, N = 2).

Conclusions

Zone 2 arch repair using the proximal-first technique for acute type A aortic dissection repair yields shorter lower-body ischemic time with a warmer core temperature, resulting in shorter cardiopulmonary bypass time, less blood product use, and fewer morbidities when compared with the arch-first technique.

Early endovascular intervention for unfavorable remodeling of the thoracic aorta after open surgery for acute DeBakey type I aortic dissection: study protocol for a multicenter, randomized, controlled trial

BACKGROUND

Total arch replacement with frozen elephant trunk has been developed with promising results for DeBakey type I aortic dissection. However, several problems, such as continuous perfusion of distal false lumen and unfavorable remodeling of distal aorta postoperatively, can seriously affect the long-term outcome. This trial aims to assess the effects of early minimally invasive endovascular repair on distal aortic remodeling and long-term clinical outcomes in patients with dominant false lumen and residual tears in the descending thoracic aorta after total arch replacement and frozen elephant trunk procedure.

METHODS

This is a protocol for a two-arm, parallel, multicenter, randomized controlled trial. A total of 154 eligible patients will be recruited from four hospitals in China and randomized on a 1:1 basis either to the experiment group (endovascular repair in addition to routine antihypertensive therapy) or the control group (routine antihypertensive therapy without early surgical treatment). The primary outcome will be the five-year all-cause mortality. The secondary outcomes will include re-intervention, ischemic symptoms, organ dysfunction, and stent-related adverse events.

DISCUSSION

If early minimally invasive endovascular repair could safely and effectively promote distal aortic remodeling and bring favorable long-term outcomes for patients with dominant false lumen and residual tears in the descending thoracic aorta after total arch replacement and frozen elephant trunk technique, it would improve the treatment strategy for DeBakey type I aortic dissection.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, CHiCTR2000030050. Registered on 11 March 2020.

Aortic Reoperation After Prior Acute Type A Aortic Dissection Repair: Don't Despair the Repair

BACKGROUND

There is paucity of data regarding reoperation after acute type A aortic dissection (ATAD) repair.

METHODS

From October 2006 to March 2022, 75 patients received 123 reoperations after ATAD (proximal, n = 17; distal, n = 103; and both, n = 3) utilizing redo sternotomy (RS, n = 68), left thoracotomy (LT, n = 44), and endovascular approach (TEVAR, n = 11). The axillary artery cannulation was utilized in 97.1% of the RS cases. A classic elephant trunk technique was used as a 2-staged procedure for distal pathology. Most LT repairs (95.5%) were completed above the celiac axis.

RESULTS

Index ATAD repairs were predominantly ascending/hemiarch repair (73.3%). The median duration from the index repair was 2.0 years. Most reoperations were elective procedures (82.1%). Hospital mortality was 2.4% (RS, 1.5%; LT, 4.5%; TEVAR, 0%), and the stroke rate was 1.6%. There was no spinal cord ischemia. The 5-year overall survival and freedom from aortic mortality or procedure were 85.2% ± 5.6% and 80.6% ± 6.1%, respectively. There were 7 distal reinterventions (prior TEVAR, n = 3; prior LT, n = 4). Two patients required LT repair after prior TEVAR and 3 patients received infrarenal aortic repair after prior LT repair. Computed tomography after completion of the distal repair (n = 45) showed an increase of distal aorta at each level as follows: celiac axis 1.2 mm/y; renal artery 1.0 mm/y; and terminal aorta 1.2 mm/y.

CONCLUSIONS

Reoperation after ATAD repair can be safely performed as an elective procedure at experienced centers. Staged distal interventions utilizing classic elephant trunk insertion and open repair above the celiac axis showed durable outcomes.

Effects of Residual Arch Tears on Late Outcomes After Hemiarch Replacement for DeBakey I Dissection

BACKGROUND

This study evaluated the effect of residual arch tears on late reinterventions and arch dilatation after hemiarch replacement for patients with acute DeBakey type I aortic dissection.

METHODS

Between January 1995 and October 2018, 160 consecutive patients who underwent hemiarch replacement for DeBakey type I dissection were retrospectively enrolled. They were divided into patients with (n = 73) and without (n = 87) residual arch tears. The arch tears group was subdivided into the proximal/middle arch (n = 26) and distal arch (n = 47) groups to evaluate arch growth rates according to the locations of residual arch tears. The endpoints were arch growth rate and late arch and composite events.

RESULTS

The arch diameter increased significantly over time in patients with residual arch tears (1.620 mm/y, P < .001). The increase occurred more rapidly when residual tears occurred at the distal arch than at the proximal/middle arch level (2.101 vs 1.001 mm/y). In the adjusted linear mixed model, residual arch tears or luminal communications at the distal arch level were significant factors associated with increases in the arch diameter over time. The 10-year freedom from late arch and composite event rate was significantly lower for patients with residual arch tears than for those without (82.4% vs 95.5%, P = .001; and 68.0% vs 89.3%, P = .002, respectively).

CONCLUSIONS

Residual arch tears are significant factors associated with late arch dilatation and reinterventions, especially for patients with distal arch tears. Extensive arch replacement during the initial surgery to avoid residual arch tears may improve long-term outcomes.

Acute aortic dissection

Although substantial progress has been made in the prevention, diagnosis, and treatment of acute aortic dissection, it remains a complex cardiovascular event, with a high immediate mortality and substantial morbidity in individuals surviving the acute period. The past decade has allowed a leap forward in understanding the pathophysiology of this disease; the existing classifications have been challenged, and the scientific community moves towards a nomenclature that is likely to unify the current definitions according to morphology and function. The most important pathophysiological pathway, namely the location and extension of the initial intimal tear, which causes a disruption of the media layer of the aortic wall, together with the size of the affected aortic segments, determines whether the patient should undergo emergency surgery, an endovascular intervention, or receive optimal medical treatment. The scientific evidence for the management and follow-up of acute aortic dissection continues to evolve. This Seminar provides a clinically relevant overview of potential prevention, diagnosis, and management of acute aortic dissection, which is the most severe acute aortic syndrome.

Long-term outcomes of total arch replacement versus proximal aortic replacement in acute type A aortic dissection: Meta-analysis of Kaplan-Meier-derived individual patient data

OBJECTIVES

To evaluate the long-term outcomes of a conservative approach (with proximal aortic replacement with or without hemiarch replacement) versus an aggressive approach (with total aortic arch replacement) in the treatment of acute type A aortic dissection (ATAAD).

METHODS

We performed a pooled analysis of Kaplan-Meier-derived individual patient data from studies with follow-up comparing the aforementioned approaches to treat patients with ATAAD.

RESULTS

Eighteen studies met our eligibility criteria, comprising 5243 patients with follow-up (Conservative: 3676 patients; Aggressive: 1567 patients). We observed a statistically significant difference in overall survival favoring the aggressive approach (hazard ratios [HR] 0.86, 95% confidence interval [CI] 0.76-0.98, p = .022), but no statistically significant difference in the risk of reoperation (HR 0.89, 95% CI 0.66-1.2, p = .439) in the overall follow-up. Landmark analyses revealed that, in the first 3 months after the procedure, mortality rates were comparable between conservative and aggressive approaches (HR 1.04, 95% CI 0.88-1.24, p = .627), but the results beyond 3 months showed improved survival in patients undergoing the aggressive surgical procedure (HR 0.71, 95% CI 0.59-0.85, p < .001). The landmark analyses also revealed that, in the first 7 years after the procedure, reoperation rates were comparable between the approaches (HR 1.03, 95% CI 0.76-1.40, p = .848), but the results beyond 7 years showed a lower risk of reoperation in patients undergoing the aggressive surgical procedure (HR 0.10, 95% CI 0.01-0.75, p = .025).

CONCLUSION

The aggressive approach seems to confer better long-term survival and lower risk of the need for reoperation in the follow-up of patients treated for ATAAD.

Left Subclavian Artery Sacrifice in Acute Aortic Dissection Repair using the Frozen Elephant Trunk

OBJECTIVE

Surgery of acute aortic dissection using the frozen elephant trunk (FET) can be complicated when the origin of the left subclavian artery (LSA) is dissected and sacrifice by ligation is a viable option. However, the LSA is supposed to play a role in neuroprotection as a major collateral. We, therefore, analyzed our results of LSA sacrifice in this cohort.

METHODS

We identified a total of 84 patients from our prospectively collected database who underwent FET repair of acute aortic dissection between October 2009 and April 2018. LSA was sacrificed in 19 patients (22.6%). Results were analyzed and compared with regard to neurological outcomes.

RESULTS

New postoperative stroke was seen in two patients (2.4%) and spinal cord injury in three patients (3.6%) overall, none in the LSA-sacrifice group. We observed a temporary neurological deficit in five patients (6.0%) overall, none in the LSA-sacrifice group. None of the patients developed acute ischemia of the left arm. Only two patients (12.5%) came back for carotid-subclavian artery bypass due to exertion-induced weakness of the left arm 3 to 4 months after the initial surgery. In-hospital mortality was 15.5% overall, with no difference between groups.

CONCLUSION

LSA sacrifice was not associated with elevated postoperative risk of either central or spinal neurological injury. Thus, it can facilitate FET repair of acute aortic dissection in selected cases when the left subclavian origin cannot be preserved. Carotid-subclavian artery bypass became necessary in only a small fraction of these patients and can be performed as a second-stage procedure.

Valve-Preserving Root Reimplantation Combined with Arch Procedure: Optimizing Patient Selection

OBJECTIVE

Patients with thoracic aortic disease commonly present with concomitant multisegment pathology. We describe the patient population, analyze outcomes, and define the patient selection strategy for valve-preserving aortic root reimplantation (VPARR) combined with the arch procedure. Methods: From 2008 to 2018, 98 patients underwent VPARR combined with the aortic arch procedure (hemi-arch, 50% [n = 49, limited repair]; total arch, 50% [n = 49, complete repair] including 39 with elephant trunk). Indications for surgery were aneurysmal disease (61%) and aortic dissection (39%). The median follow-up was 17 months (IQR, 8 to 60 months). Results: There were no operative deaths or paraplegia, and 5 patients underwent re-exploration for bleeding. During follow-up, 2 patients required aortic valve replacement for severe aortic insufficiency at 1 and 5 years, and 4 patients died. In the limited repair group, 1 patient underwent reintervention for aortic arch replacement, whereas 4 patients underwent planned intervention (1 endovascular and 3 open thoracoabdominal aortic repair). In the complete repair group, 23 patients underwent planned intervention (15 endovascular and 8 open thoracoabdominal repair). Conclusions: Single-stage, complete, proximal aortic repair including VPARR combined with total aortic arch replacement is as safe and feasible to perform as limited arch repair and facilitates further intervention in carefully selected patients with diffuse aortic pathology at centers of expertise.

Ulcer-like projections into the dilated false lumen after stent-graft placement for aortic dissection: A case report

RATIONALE

Acute type A aortic dissection and chronic type B aortic dissection (TBAD) occurs simultaneously in rare cases. Although the development of ulcer-like projection (ULP) is associated with an increase in adverse aorta-related events, the false-lumen enlargement caused by the ULP progression is uncommon.

PATIENT CONCERNS

A 72-year-old female with chronic TBAD was admitted to our unit with back and chest pain. Computed tomography revealed acute type A aortic dissection and a hematoma caused by rupturing of the descending aorta due to chronic TBAD. After endovascular intervention, the false lumen thrombosed and shrunk.

DIAGNOSIS

After 9 months, a developing ULP, which projected into a dilating false lumen, was found. An impending ruptured descending aortic aneurysm was confirmed.

INTERVENTIONS

Emergency Total arch replacement and thoracic endovascular aortic repair (TEVAR) was performed.

OUTCOMES

The procedure was successful. One year later, regular follow-up showed that the false lumen had completely shrunk.

LESSONS

ULP can arise and cause progressive dilation of false lumen after TEVAR. Careful and regular computed tomography examinations are required for early diagnosis of false lumen becoming thrombosed after TEVAR. Close follow-up and timely intervention, including TEVAR, should be considered in cases of aortic enlargement due to a newly developed ULP.

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.

Outcome Comparison Between Open and Endovascular Aortic Repair for Retrograde Type A Intramural Hematoma With Intimal Tear in the Descending Thoracic Aorta: A Retrospective Observational Study

Objective: The optimal treatment modality for retrograde type A intramural hematoma (IMH) remains debatable. This study evaluated and compared surgical outcomes and aortic remodeling after open aortic repair and thoracic endovascular aortic repair (TEVAR) in patients with retrograde type A IMH with a primary intimal tear or ulcer like projection in the descending aorta.

Methods: A single center, retrospective observational study was performed on patients with retrograde type A IMH undergoing either open aortic repair and TEVAR. From June 2009 and November 2019, 46 patients with retrograde type A IMH who received either open aortic repair or TEVAR at our institution were reviewed for clinical outcomes, including post-operative mortality/morbidity, re-intervention rate and aortic remodeling.

Results: 33 patients underwent open aortic repair and 13 underwent TEVAR. Median age was 68 years (interquartile range [IQR] 15.2 years) and 63 years (IQR 22.5 years) for the open repair group and TEVAR group, respectively. The median duration of follow-up for TEVAR patients was 37.6 months and 40.3 months for open aortic repair. No difference in the 5-year estimated freedom from all-cause mortality (82.1 vs. 87.8%, p = 0.34), re-intervention (82.5 vs. 93.8%, p = 0.08), and aortic-related mortality (88.9 vs. 90.9%, p = 0.88) were observed between the TEVAR and open repair group, respectively; however, the open repair group had a significantly higher 30-day composite morbidity (39.4 vs. 7.7%, p = 0.037). All patients from both treatment groups had complete resolution of the IMH in the ascending aorta. With regard to the descending thoracic aorta, TEVAR group had a significantly greater regression in the diameter of the false lumen or IMH thickness when compared to the open repair group [median 14mm (IQR 10.1) vs. 5mm (IQR 9.5), p < 0.001].

Conclusion: TEVAR and open aortic repair were both effective treatments for retrograde type A IMH, in which no residual ascending aortic IMH was observed during follow-up. TEVAR was also associated with lower post-operative composite morbidities and better descending aortic remodeling. In selected patients with retrograde type A IMH, TEVAR might be a safe, effective alternative treatment modality.

Simplified Zone 2 Arch Repair using a Trifurcated Graft for Acute Type A Dissection

We report a simplified Zone 2 arch repair using a trifurcated graft for acute type A aortic dissection. The right axillary artery is cannulated. After completion of proximal aortic repair using a one-branched graft, a trifurcated graft is anastomosed to the ascending graft just above the proximal suture line or coronary buttons in case of Bentall procedure. Distal aortic anastomosis is performed at the Zone 2 level under unilateral antegrade cerebral perfusion. Full cardiopulmonary bypass flow is resumed via the right axillary and ascending graft using both Y-shaped arterial limbs. The left common carotid and innominate artery are sequentially anastomosed.

Note the descending aorta: predictors of postoperative major adverse aortic event in pure acute type A intramural hematoma

Background

Intramural hematomas (IMHs) may originate from small intimal tears. Although most surgeries for acute type A IMH are conventionally performed solely at the proximal aorta, regardless of the primary intimal tear site, the remnant aortic remodeling stays important during the follow-up period after surgery.

Methods

Forty-seven patients with “pure” acute type A IMHs who underwent surgery from January 2008 to December 2019 were retrospectively analyzed. Acute type A IMH in the entire region without penetrating aortic ulcer (PAU) and aortic dissection (AD), which upon initial computed tomography (CT), can be considered as an intimal tear site, was defined as “pure” type. The maximal diameter of the aorta, maximal thickness of the IMH, and hematoma thickness ratio (HTR) of the ascending and descending aortae were measured from the preoperative computed tomographic scan. The hematoma thickness index was defined as the HTR of the descending aorta divided by that of the ascending aorta. Major adverse aortic events (MAAEs) were defined as AD, rupture, or newly developed PAU and aortic death. Predictors for postoperative MAAEs were analyzed using preoperative computed tomographic findings.

Results

The measurements of the descending aorta were larger and those of the ascending aorta were smaller in the MAAEs group, than in the corresponding other. The hematoma thickness index was significantly higher in the group with MAAEs, than in the group without; this variable was an independent predictor of MAAEs. During surgery, intimal tears were found in 16/47 (34%) patients. The hematoma thickness index was significantly smaller in the group with intimal tears than in the group without the tears. The aortic measurement appears to reflect the tear site.

Conclusions

Hematoma thickness index was an independent predictor of MAAE after acute type A IMH surgery. Long-term periodical follow-up with early reintervention may, therefore, be necessary to improve outcome in these patients. As the optimal treatment method is still controversial, inferring the location of the primary tear through the hematoma thickness index can be helpful in determining the treatment method.

Outcomes of long versus short stent cronus hybrid prosthesis in type A aortic dissection: A single centre experience

OBJECTIVES

The frozen elephant trunk (FET) technique has become an important tool in the treatment of acute type A aortic dissection. The aim of this study was to evaluate the effect of long FET on spinal cord injury (SCI) and distal aortic remodeling after acute type A aortic dissection based on clinical and radiological outcomes.

METHODS

From January 2018 to November 2019, 158 patients (mean age 51.8 years [range: 32-78 years], 88.6% male) with acute type A aortic dissection were treated by FET with 100 mm (n = 113) or 150 mm (n = 45) open hybrid stent graft prosthesis. Patients were divided into two groups according to the length of FET. The clinical and radiological outcomes of the patients were reviewed retrospectively.

RESULTS

Postoperative outcomes did not differ significantly: in-hospital mortality (9.7% vs. 6.7%, p = .758) and SCI (5.3% vs. 2.2%, p = .674). Aortic remodeling, which was evaluated by aortic diameter, true lumen diameter, false lumen (FL) diameter and the rate of FL complete thrombosis, was more positive in long FET group in the descending thoracic aorta during the follow-up period. At the abdominal level, there was no statistically significant difference between the two groups.

CONCLUSIONS

The long version of FET does not increase the risk of SCI in patients with acute type A aortic dissection. The application of long FET can achieve better results in terms of remodeling of the thoracic aorta in the short- and medium-term follow-up.

The frozen elephant trunk technique for aortic dissection is safe after previous aortic repair

OBJECTIVES

The goal of this study was to evaluate outcomes of aortic arch replacement using the frozen elephant trunk (FET) technique after previous proximal and/or distal open or endovascular thoracic aortic repair.

METHODS

Sixty-three patients [median age: 63 (55-74) years; 65% men] were operated on for acute or chronic aortic dissection after previous proximal and/or distal open or endovascular thoracic aortic repair. Intraoperative details, clinical outcome and follow-up results were evaluated.

RESULTS

The median time between the index and the FET procedure was 81 (40-113) months. Fifty-eight (92%) patients had already undergone proximal aortic surgery; supracoronary ascending aortic replacement was the most frequent index procedure [n = 25 (40%)]. Distal aortic interventions had been done in 8 (13%) patients including endovascular thoracic aortic repair in 6 patients (10%). In-hospital mortality was 3% (n = 2). Postoperative strokes occurred in 5 patients (8%); of those, 1 stroke was dissection-related (2%). Subsequent aortic reinterventions after the FET procedure had to be done in 33% (n = 21).

CONCLUSIONS

Outcomes of aortic arch replacement using the FET technique after previous proximal and/or distal open or endovascular thoracic aortic repair are associated with low mortality and morbidity. Still, postoperative stroke remains an issue. After the successful accomplishments, the approach serves as an ideal platform for the secondary surgical or endovascular downstream aortic procedures, which are frequently needed.

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.

Acute Kidney Injury After Acute Repair of Type A Aortic Dissection

BACKGROUND

The aim of this study was to examine the incidence, risk factors, and outcomes of patients with acute kidney injury (AKI) after surgery for acute type A aortic dissection (ATAAD) using the Nordic Consortium for Acute Type A Aortic Dissection registry.

METHODS

Patients who underwent ATAAD surgery at 8 Nordic centers from 2005 to 2014 were analyzed for AKI according to the RIFLE criteria. Patients who died intraoperatively, those who had missing baseline or postoperative serum creatinine, and patients on preoperative renal replacement therapy were excluded.

RESULTS

AKI occurred in 382 of 941 patients (40.6%), and postoperative dialysis was required for 105 patients (11.0%). Renal malperfusion was present preoperatively in 42 patients (5.1%), of whom 69.0% developed postoperative AKI. In multivariable analysis patient-related predictors of AKI included age (per 10 years; odds ratio [OR], 1.30; 95% confidence interval [CI], 1.15-1.48), body mass index >30 kg/m² (OR, 2.16; 95% CI, 1.51-3.09), renal malperfusion (OR, 4.39; 95% CI, 2.23-9.07), and other malperfusion (OR, 2.10; 95% CI, 1.55-2.86). Perioperative predictors were cardiopulmonary bypass time (per 10 minutes; OR, 1.04; 95% CI, 1.02-1.07) and red blood cell transfusion (OR per transfused unit, 1.08; 95% CI, 1.06-1.10). Rates of 30-day mortality were 17.0% in the AKI group compared with 6.6% in the non-AKI group (P < .001). In 30-day survivors AKI was an independent predictor of long-term mortality (hazard ratio, 1.86; 95% CI; 1.24-2.79).

CONCLUSIONS

AKI is a common complication after surgery for ATAAD and independently predicts adverse long-term outcome. Of note one-third of patients presenting with renal malperfusion did not develop postoperative AKI, possibly because of restoration of renal blood flow with surgical repair. Mortality risk persists beyond the perioperative period, indicating that close clinical follow-up of these patients is required.

A Review on the Surgical Management of Intramural Haematoma of the Aorta

Intramural haematoma (IMH) of the aorta is one of the causes of acute aortic syndrome which often requires emergency or urgent life-saving surgery. In this review, we discuss the pathophysiology, epidemiology, clinical presentation, diagnostic imaging, surgery and clinical outcomes associated with IMH.

Midterm Outcomes of the Dissected Aorta Repair Through Stent Implantation Trial

BACKGROUND

The intimal flap at the distal aortic anastomosis after standard aortic dissection repair creates distal anastomotic new entry, leading to false lumen (FL) pressurization and true lumen (TL) collapse and resulting in increased mortality, malperfusion, aortic growth, and reinterventions. The Ascyrus Medical Dissection Stent (AMDS; Ascyrus Medical, Boca Raton, FL) is a hybrid prosthesis that seals and depressurizes the FL at the distal anastomosis while expanding and pressurizing the TL.

METHODS

The Dissected Aorta Repair Through Stent Implantation trial is a prospective, nonrandomized, international type A dissection trial where patients with acute DeBakey I dissections were enrolled between March 2017 and January 2019. Forty-seven patients were enrolled (median age, 62.5; 67.4% men) with a median follow-up of 631 days.

RESULTS

All patients underwent emergent surgical repair with successful AMDS implantation. One patient was excluded because of use in iatrogenic dissection. Overall mortality at 30 days and 1 year was 13.0% (6/46) and 19.6% (9/46), whereas new strokes occurred in 6.5% (3/46). Over 95% of vessel malperfusions resolved because of AMDS-induced TL expansion, including 3 patients with preoperative paralysis. Positive remodeling of the aortic arch occurred in 100% of cases with complete obliteration or thrombosis of the FL in 74%. In the proximal descending thoracic aorta positive remodeling occurred in 77% and complete obliteration or FL thrombosis in 53% of cases.

CONCLUSIONS

AMDS facilitates single-stage management of malperfusion and induces positive remodeling of the aortic arch through effective sealing of the distal anastomotic FL, depressurization of the FL with expansion, and pressurization of the TL. Importantly the use of AMDS is safe and reproducible.

The frozen elephant trunk technique in acute DeBakey type I aortic dissection

Although advances in the field of cardiovascular surgery have improved outcomes for patients with acute DeBakey type I aortic dissection, postoperative in-hospital mortality and morbidity remain substantial. The frozen elephant trunk technique has become a treatment option for this disease and was developed primarily to extend repair into the proximal descending thoracic aorta during aortic arch repair (because the descending thoracic aorta is largely inaccessible via median sternotomy), thus avoiding, delaying, or facilitating subsequent repair of residual native aorta. In this review, we discuss the evidence for and future development of frozen elephant trunk reconstruction for acute DeBakey type I aortic dissection.

Endovascular Aortic Repair After Proximal Stent Graft Migration of a Modified Frozen Elephant Trunk

We describe the endovascular repair for a proximal endograft migration following a modified frozen elephant trunk (mFET) repair for a retrograde type A dissection (retro-A AD). A 40-year-old man presented with a type B aortic dissection that progressed to a retro-A AD. He was emergently taken to the operating room for an mFET repair. Computed tomography (CT) angiogram on the day of discharge revealed that the proximal end of the endograft migrated through the primary intimal tear resulting in obstruction of true lumen flow. The patient returned to the catheterization lab for endovascular repair utilizing a through-and-through wire to extend the endograft proximally and a left carotid-subclavian artery bypass. This complication highlights the importance of postoperative CT surveillance and the endovascular technique utilized to restore aortic true lumen flow.

Factors associated with acute stroke after type A aortic dissection repair: An analysis of the Society of Thoracic Surgeons National Adult Cardiac Surgery Database

OBJECTIVES

Data from the Society of Thoracic Surgeons Adult Cardiac Surgery Database was used to examine the incidence and factors associated with acute stroke following type A repair.

METHODS

Acute type A aortic dissection repairs performed from 2014 to 2017 were identified from the Society of Thoracic Surgeons Adult Cardiac Surgery Database. The effect of cannulation strategy (eg, axillary, femoral, direct, or innominate), lowest temperature, cerebral protection techniques (antegrade cerebral profusion, retrograde cerebral perfusion, both, or none), repair technique, and institutional volume on postoperative stroke was investigated.

RESULTS

Acute type A repair was performed on 8937 patients at 772 centers, of which 7353 met inclusion criteria. Operative mortality was 17% and incidence of postoperative stroke was 13%. Axillary cannulation was associated with lower risk of stroke versus femoral (odds ratio, 0.60; P < .001). Retrograde cerebral perfusion was associated with reduced risk for stroke compared with no cerebral perfusion (odds ratio, 0.75; P = .008) or antegrade cerebral perfusion (odds ratio, 0.75; P = .007). Total arch replacement was associated with greater risk for stroke versus hemiarch technique (odds ratio, 1.30; P = .013). Longer circulatory arrest time, cerebral perfusion time, and cardiopulmonary bypass time were all related to higher risk of postoperative stroke.

CONCLUSIONS

Stroke is a common complication after type A repair. Axillary cannulation was associated with lower incidence of stroke, whereas femoral cannulation significantly increased the risk of stroke regardless of the cerebral perfusion strategy or the degree of hypothermia. Retrograde cerebral profusion was found to have reduced risk for postoperative stroke. Degree of hypothermia and center volume were not related to stroke incidence.

Are We There Yet? Emerging Milestones in Aortic Dissection Care

See Article Reutersberg et al.

One-stage hybrid aortic repair using the frozen elephant trunk in acute DeBakey type I aortic dissection

Background

The extent of emergent surgery for acute DeBakey type I aortic dissection is discussed controversial. The frozen elephant trunk (FET) technique in addition to ascending and arch repair promotes aortic remodelling in the descending aorta and thus may provide superior long-term results in terms of less secondary re-interventions and reduced mortality linked to the downstream aorta.

Methods

Between October 2009 and December 2016, a total of 72 patients underwent emergent hybrid aortic repair using the FET for acute DeBakey type I aortic dissection at our centre. Data were analysed from our prospectively collected database and clinical and imaging mid-term follow-up was obtained.

Results

Implant success was 98.6% with an overall 30-day-mortality of 15.3%. New postoperative stroke was seen in 2.8%, new spinal cord injury in 4.2%. In follow-up (mean 37.8±21.2 months) cumulative survival was 75.0% with freedom from distal reintervention in 96.7% and aortic remodelling rate in the descending aorta in 96.5%.

Conclusions

Hybrid aortic repair using the FET in acute DeBakey type I aortic dissection does not elevate the perioperative risk of mortality and provides excellent aortic remodelling with low distal re-intervention rate in mid-term follow-up.

Techniques and outcomes of secondary open repair for chronic dissection after acute repair of type A aortic dissection

Despite successful repair of acute type A aortic dissection (TAAD), the distal false lumen may remain patent resulting in progressive degeneration of the remaining distal aorta. This can lead to aneurysmal dilatation and risk of rupture. Open distal reoperation to replace the residually dissected thoraco-abdominal aorta may be accomplished with acceptable morbidity and mortality in experienced hands. This can be facilitated when the index operation for acute TAAD is tailored to exclude all primary tears and set the arch and descending aorta for a subsequent open, endovascular or hybrid procedure.

Simplifying aortic arch surgery: open zone 2 arch with single branched thoracic endovascular aortic repair completion

Background

Distal aortic complications from acute DeBakey I dissection repair are an important source of late morbidity and mortality. We present an early experience of using a novel single-branched thoracic aortic endograft in conjunction with open techniques to treat acute DeBakey I aortic dissection.

Methods

The patients in this series include five hyperacute dissections managed with a combined zone 2 partial arch replacement and placement of a zone 2 single subclavian branch endograft.

Results

There were no perioperative mortalities, strokes, or spinal cord ischemia in any patients at either stage of the procedure. At follow-up imaging, no patients had anterograde flow into the false lumen. All patients experienced false lumen thrombosis in the stented portion of the aorta.

Conclusions

This combination of open repair techniques and the use of a novel branched endograft resulted in excellent early outcomes in this pioneer series. Further investigation of these techniques in a prospective fashion is warranted.

Protecting the brain and spinal cord in aortic arch surgery

Protection of the central nervous system-either the brain or the spinal cord-during aortic surgery has been the subject of intense research over the past several decades. While it took some 30 years to prove that some of the techniques first practiced in animals are valuable, surgeons can now take courage from 50 years of research that has resulted in superb outcomes, particularly when compared with historical results. Complex total arch operations and descending aortic operations can now be performed with less than a 2% rate of stroke, spinal cord injury, or death. Thoracoabdominal aortic operations and endovascular procedures have also become considerably safer with excellent results reported. The following review will discuss some of the historical outcomes, innovations, iterations, current techniques, and outcomes.