Medical and surgical management of acute type B aortic intramural hematoma

Natural history and long-term outcomes of medically managed Type B intramural hematoma

OBJECTIVE

Type B intramural hematoma (IMH) is often managed medically, yet may progress to dissection, aneurysmal dilation, or rupture. The aim of this study was to report the natural history of medically managed Type B IMH, and factors associated with progression.

METHODS

We reviewed patients with medically managed Type B IMH between January 1995 to December 2022 at a single center. Any patients with immediate surgical or endovascular intervention were excluded. Demographic profiles, comorbidities, imaging, and follow-up details were reviewed. Patients were divided into two groups: Group 1 had isolated IMH, and Group 2 had IMH along with aneurysm or dissection at the time of presentation. On follow-up, progression was defined as degeneration to aneurysm/dissection or increase in the thickness of IMH in Group 1. In Group 2, progression was an increase in the size of aneurysm or development of new dissection.

RESULTS

Of 104 patients with Type B IMH during the study period, 92 were medically managed. The median age was 77 years, and 45 (48.9%) were females. Comorbidities included hypertension (83.7%), hypercholesterolemia (44.6%), and active smoking (47.8%). Mean Society for Vascular Surger comorbidity score was 6.3. Mean IMH thickness and aortic diameter at presentation were 8.9 mm and 38.3 mm, respectively. Median follow-up was 55 months. Overall survival at 1 year and 5 years was 85.8% and 61.9%, respectively. During follow-up, 19 patients (20.7%) required intervention, more common in Group 2 (Group 1, 8/66; 12.3% vs Group 2, 11/26; 42.3%; P = .001). This resulted in higher freedom from intervention in Group 1 at 1 year (93.5% vs 62.7%) and 5 years (87.5% vs 51.1%; P < .001). Indication for intervention was dissection (n = 4), aneurysm (n = 12), and progression of IMH (n = 3). In Group 1, progression was seen in 25 (37.9%), three (4.5%) remained stable, 29 (43.9%) had complete resolution of IMH, and nine patients were lost to follow-up. In Group 2, 11 patients (42.3%) had progression, seven (26.9%) remained stable, and eight were lost to follow-up. IMH thickness at presentation >7.2 mm is associated with both increased odds of progression (odds ratio, 3.3; 95% confidence interval, 1.2-11.1; P = .03) and intervention (odds ratio, 5.5; 95% confidence interval, 1.3-36.9; P = .03) during the follow-up.

CONCLUSIONS

Although many patients with Type B IMH managed medically stabilize or regress, progression or need for intervention can occur in up to 40% of cases. This is associated with the presence of aneurysm, dissection, and IMH thickness. Long-term follow-up is mandatory as late interventions occur, particularly for higher risk patients.

Five Year Results of Endovascular versus Medical Therapy in Acute Type B Aortic Intramural Haematoma: Meta-Analysis of Reconstructed Time to Event Data

OBJECTIVE

To evaluate outcomes in the follow up of thoracic endovascular aortic repair (TEVAR) vs. medical therapy in patients with acute type B aortic intramural haematoma (IMH).

DATA SOURCES

The following sources were searched for articles meeting the inclusion criteria and published by July 2023: PubMed/MEDLINE, EMBASE, CENTRAL/CCTR (Cochrane Controlled Trials Register).

REVIEW METHODS

This systematic review with pooled meta-analysis of time to event data followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines, and its protocol was registered on the public platform PROSPERO (CRD42023456222). The following were analysed: overall survival (all cause mortality), aortic related mortality, and restricted mean survival time. Certainty of evidence was evaluated through the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool.

RESULTS

Eight studies met the eligibility criteria, including 1 015 patients (440 in the TEVAR group and 575 in the medical therapy group). All studies were observational, and the pooled cohort had a median follow up of 5.1 years. Compared with patients who received medical therapy alone, those who underwent TEVAR had a statistically significantly lower risk of all cause death (HR 0.44, 95% CI 0.30 - 0.65; p < .001; GRADE certainty: low), lower risk of aortic related death (HR 0.04, 95% CI 0.01 - 0.31; p = .002; GRADE certainty: low) and lifetime gain (restricted mean survival time was overall 201 days longer with TEVAR; p < .001).

CONCLUSION

Thoracic endovascular aortic repair may be associated with lower risk of all cause and aortic related death compared with medical therapy in patients with acute type B IMH; however, the underlying data are not strong enough to draw robust clinical conclusions. Randomised controlled trials with large sample sizes and longer follow up are warranted to elucidate this question.

Acute Type B Intramural Hematoma: Novel Insights in the Endovascular Era

BACKGROUND

The pathophysiology and behavior of acute type B intramural hematoma (TBIMH) is poorly understood. The purpose of this study is to characterize the pathophysiology, fate, and outcomes of TBIMH in the endovascular era.

METHODS

A retrospective analysis of a US Aortic Database identified 70 patients with TBIMH from 2008 to 2022. Patients were divided into groups and analyzed based upon subsequent management: early thoracic endovascular aortic repair (TEVAR; Group 1) or hospital discharge on optimal medical therapy (OMT) (Group 2).

RESULTS

Of 70 total patients, 43% (30/70) underwent TEVAR (Group 1) and 57% (40/70) were discharged on OMT (Group 2). There were no significant differences in age, demographics, or comorbidities between groups. Indications for TEVAR in Group 1 were as follows: 1) Penetrating atheroscletoic ulcer (PAU) or ulcer-like projection (n = 26); 2) Descending thoracic aortic aneurysm (n = 3); or 3) Progression to type B aortic dissection (TBAD) (n = 2). Operative mortality was zero. No patient suffered a stroke or spinal cord ischemia. During the follow-up period, 50% (20/40) of Group 2 patients required delayed surgical intervention, including TEVAR in 14 patients and open repair in 6 patients. Indications for surgical intervention were as follows: 1) Development of a PAU / ulcer-like projection (n = 13); 2) Progression to TBAD (n = 3), or 3) Concomitant aneurysmal disease (n = 4). Twenty patients did not require surgical intervention. Of the initial cohort, 71% of patients required surgery, 9% progressed to TBAD, and 19% had regression or stability of TBIMH with OMT alone.

CONCLUSIONS

The most common etiology of TBIMH is an intimal defect. Progression to TBAD and intramural hematoma regression without an intimal defect occurs in a small percentage of patients. An aggressive strategy with endovascular therapy and close surveillance for TBIMH results in excellent short-term and long-term outcomes.

The Role of Endovascular Repair Timing in Uncomplicated Acute Type B Intramural Hematoma Management

BACKGROUND

With favorable results of thoracic endovascular aortic repair (TEVAR) in patients with uncomplicated acute type B intramural hematoma (uTBIMH), TEVAR is increasingly utilized in the management of patients with uTBIMH. However, optimal timing for intervention has not been decided. This study aimed to compare the efficacy of acute and delayed TEVAR in patients with uTBIMH.

METHODS

We included patients with uTBIMH who underwent TEVAR between October 2014 and December 2021. The participants were divided into the acute TEVAR (aTEVAR) and delayed TEVAR (dTEVAR) groups. We analyzed the total aortic diameter (TAD)/true lumen diameter (TLD) ratio on computed tomography angiography (CTA) and aortic-related adverse events and all-cause mortality (AREM).

RESULTS

We included 34 individuals with uTBIMH, among which 20 underwent aTEVAR and 14 underwent dTEVAR. We observed no significant differences in baseline characteristics between both groups. However, compared with the aTEVAR group, better aortic remodeling was achieved in the dTEVAR group before discharge (1.32 ± 0.11 vs. 1.21 ± 0.09, P = 0.005) and at the 1-year follow-up (1.18 ± 0.09 vs. 1.10 ± 0.04, P = 0.034). Although the 30-day and 1-year follow-up outcomes of AREM were not significantly different, the Kaplan-Meier analysis showed that AREM incidence in the dTEVAR group was significantly lower than that in the aTEVAR group (85.7% for dTEVAR vs. 65.0% for aTEVAR, log-rank P = 0.20). Moreover, subgroup analysis revealed a significant difference in the TAD/TLD ratio between the aTEVAR and dTEVAR groups in individuals without a focal intimal disruption (1.33 ± 0.11 vs. 1.17 ± 0.09, P = 0.008).

CONCLUSIONS

For individuals with uTBIMH, delaying TEVAR by >7 days improved aortic remodeling and lowered the incidence of early AREM. Additionally, the absence of focal intimal disruption on preoperative CTA supports delayed intervention.

Postoperative acute kidney injury after thoracic endovascular aortic repair for acute type B aortic dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) has evolved as the standard for treating complicated acute type B aortic dissection (ATBAD). Acute kidney injury (AKI) is a common complication in critically ill patients and is commonly observed in patients with ATBAD. The purpose of the study was to characterize AKI after TEVAR.

METHODS

All patients who underwent TEVAR for ATBAD from 2011 through 2021 were identified using the International Registry of Acute Aortic Dissection. The primary end point was AKI. A generalized linear model analysis was performed to identify a factor associated with postoperative AKI.

RESULTS

A total of 630 patients presented with ATBAD and underwent TEVAR. The indication for TEVAR was complicated ATBAD in 64.3%, high-risk uncomplicated ATBAD in 27.6%, and uncomplicated ATBAD in 8.1%. Of 630 patients, 102 (16.2%) developed postoperative AKI (AKI group) and 528 patients (83.8%) did not (non-AKI group). The most common indication for TEVAR was malperfusion (37.5%). In-hospital mortality was significantly higher in the AKI group (18.6% vs 4%; P < .001). Postoperatively, cerebrovascular accident, spinal cord ischemia, limb ischemia, and prolonged ventilation were more commonly observed in the AKI group. The expected mortality was similar at 2 years between the two groups (P = .51). Overall, the preoperative AKI was observed in 95 (15.7%) in the entire cohort consisting of 60 (64.5%) in the AKI group and 35 (6.8%) in the non-AKI group. A history of CKD (odds ratio, 4.6; 95% confidence interval, 1.5-14.1; P = .01) and preoperative AKI (odds ratio, 24.1; 95% confidence interval, 10.6-55.0; P < .001) were independently associated with postoperative AKI.

CONCLUSIONS

The incidence of postoperative AKI was 16.2% in patients undergoing TEVAR for ATBAD. Patients with postoperative AKI had a higher rate of in-hospital morbidities and mortality than those without. A history of CKD and preoperative AKI were independently associated with postoperative AKI.

Thoracic Endovascular Aortic Repair versus Optimal Medical Treatment in Patients with Type B Intramural Hematoma: A Meta-Analysis

PURPOSE

We intended to study the effect of thoracic endovascular aortic repair (TEVAR) and optimal medical treatment (OMT) on type B intramural hematoma (BIMH).

METHODS

We searched PubMed, EMbase, Cochrane Library, and China National Knowledge Infrastructure databases that compared TEVAR and OMT in patients with BIMH. Two authors independently assessed the risk of bias using the Newcastle-Ottawa Scale. The rate ratio (RR) and 95% confidence interval were used to calculate the outcome. The primary endpoints were aortic-related death and regression/resolution. Secondary endpoints were all-cause death, progression to dissection, and secondary intervention.

RESULTS

Eight observational studies were included in the analysis. TEVAR reduced aortic-related death (RR 0.22, 95% CI 0.08-0.56, P = 0.002, I² = 24%) and promoted hematoma regression/resolution (RR 1.48, 95% CI 1.05-2.10, P <0.05, I² = 71%) compared to OMT. Moreover, TEVAR was associated with a reduction in progression to dissection (RR 0.32, 95% CI 0.13-0.81, P <0.02, I² = 39%) and secondary intervention (RR 0.18, 95% CI 0.09-0.37, P <0.00001, I² = 38%) compared to OMT. However, all-cause death has no significant difference between the two groups (RR 0.45, 95% CI 0.17-1.19, P = 0.11, I² = 58%).

CONCLUSIONS

The results of this meta-analysis suggested that TEVAR is an effective treatment for BIMH, which can delay the progression of intramural hematoma and promotes regression/resolution. More research about indications of TEVAR is still needed.

Comparison of population characteristics and clinical outcomes of patients with type B aortic dissection or aortic intramural hematoma underwent thoracic endovascular aortic repair: a propensity score-matched analysis

BACKGROUNDS

Survival and aortic-related adverse events after thoracic endovascular aortic repair (TEVAR) for aortic intramural hematoma (IMH) and aortic dissection (AD) are controversial. We aimed to assess the preoperative characteristics and to evaluate TEVAR outcomes of acute type B IMH and AD.

METHODS

Between June 2002 and May 2021, 83 patients with acute type B IMH and 755 patients with acute type B AD underwent TEVAR at the General Hospital of Northern Theater Command. We retrospectively analyzed data from these patients, including clinical characteristics and follow-up outcomes.

RESULTS

The patients with IMH were significantly older than the ones with AD (P < 0.001). Diabetes mellitus (P = 0.035) and ischemic cerebrovascular disease (P = 0.017) were more common in the IMH group than in the AD group. The results demonstrated a less long-term aortic-related death-free survival rate in the IMH group than the AD group for all the patients (P = 0.014) and the matched patients (P = 0.027). It also presents a lower long-term overall survival rate (P = 0.047) and aortic-related event-free rate (P = 0.048) in the IMH group than in the matched patients.

CONCLUSIONS

Compared with AD patients, patients with IMH who underwent TEVAR had a worse long-term outcome of aortic-related survival in all and matched patients.

Acute Kidney Injury in Patients Undergoing Surgery for Type A Acute Aortic Dissection

BACKGROUND

Acute kidney injury (AKI) after repair of type A acute aortic dissection (TAAAD) has been shown to affect both short- and long-term outcomes. This study aimed to validate the impact of postoperative AKI on in-hospital and long-term outcomes in a large population of dissection patients presenting to multinational aortic centers. Additionally, we assessed risk factors for AKI including surgical details.

METHODS

Patients undergoing surgical repair for TAAAD enrolled in the International Registry of Acute Aortic Dissection database were evaluated to determine the incidence and risk factors for the development of AKI.

RESULTS

A total of 3307 patients were identified. There were 761 (23%) patients with postoperative AKI (AKI group) vs 2546 patients without (77%, non-AKI group). The AKI group had a higher rate of in-hospital mortality (n = 193, 25.4% vs n = 122, 4.8% in the non-AKI group, P < .001). Additional postoperative complications were also more common in the AKI group including postoperative cerebrovascular accident, reexploration for bleeding, and prolonged ventilation. Independent baseline characteristics associated with AKI included a history of hypertension, diabetes, chronic kidney disease, evidence of malperfusion on presentation, distal extent of dissection to abdominal aorta, and longer cardiopulmonary bypass time. Kaplan-Meier survival curves revealed decreased 5-year survival among the AKI group (P < .001).

CONCLUSIONS

AKI occurs commonly after TAAAD repair and is associated with a significantly increased risk of operative and long-term mortality. In this large study using the International Registry of Acute Aortic Dissection database, several factors were elucidated that may affect risk of AKI.

Association of Thoracic Aortic Aneurysm Versus Aortic Dissection on Outcomes After Thoracic Endovascular Aortic Repair

Background Because thoracic endovascular aortic repair (TEVAR) has become the standard of care for complicated type B aortic dissection (TBAD) and descending thoracic aortic (DTA) aneurysm, it is important to understand outcomes and use of TEVAR across thoracic aortic pathologies. Methods and Results This was an observational study of patients with TBAD or DTA undergoing TEVAR from 2010 to 2018, using the Nationwide Readmissions Database. In-hospital mortality, postoperative complications, admission costs, and 30- and 90-day readmissions were compared between the groups. Mixed model logistic regression was used to identify variables associated with mortality. An estimated total of 12 824 patients underwent TEVAR nationally, of which 6043 had an indication of TBAD and 6781 of DTA. Patients with aneurysms were more likely to be older, women, have cardiovascular disease, and have chronic pulmonary disease compared with patients with TBAD. Weighted in-hospital mortality was higher for TBAD (8% [1054/12 711] versus 3% [433/14 407], P<0.001), compared with DTA, as were all postoperative complications. Patients with TBAD had a higher cost of care during their index admission (57.3 versus 38.8 × $1000, P<0.001), compared with DTA. The 30-day and 90-day weighted readmissions were more frequent for the TBAD group compared with DTA (20% [1867/12 711] and 30% [2924/12 711] versus 15% [1603/14 407] and 25% [2695/14 407], respectively, P<0.001). On multivariable adjustment, TBAD was independently associated with mortality (odds ratio, 2.06 [95% CI, 1.68-2.52]; P<0.001). Conclusions After TEVAR, patients who presented with TBAD had higher rates of postoperative complications, in-hospital mortality, and cost compared with DTA. The incidence of early readmission was substantial for patients undergoing TEVAR, faring worse for those undergoing TEVAR for TBAD as compared with DTA.

Sex-Related Differences in Clinical Outcomes After Thoracic Endovascular Aortic Repair

Background Thoracic endovascular aortic repair (TEVAR) has been increasingly used for the treatment of descending thoracic aortic aneurysms and dissections. This study sought to evaluate the influence of sex on outcomes after TEVAR. Methods and Results This was an observational study from the Nationwide Readmissions Database analyzing all patients who underwent TEVAR from 2010 to 2018. Sampling weights were used to generate national estimates. International Classification of Diseases-Clinical Modification codes were used to identify patients with thoracic aortic aneurysms or dissections who underwent TEVAR. Patients were dichotomized according to sex, and 1:1 propensity score matching was applied. Mixed model regression for in-hospital mortality and weighted logistic regression with bootstrapping for 30-day readmissions were performed. A supplemental analysis was performed according to pathology (aneurysm or dissection). A weighted total of 27 118 patients were identified. Propensity-matching yielded 5026 risk-adjusted pairs. Men were more likely to undergo TEVAR for type B aortic dissection, whereas women were more likely to undergo TEVAR for aneurysm. In-hospital mortality was roughly 5% and was equivalent in the matched groups. Men were more likely to have paraplegia, acute kidney injury, and arrhythmias, while women were more likely to require transfusions after TEVAR. There were no significant differences in myocardial infarction, heart failure, respiratory failure, spinal cord ischemia, mesenteric ischemia, stroke, or 30-day readmission between the matched groups. On regression analysis, sex was not an independent risk factor for in-hospital mortality. Female sex was, however, significantly associated with a decreased odds of 30-day readmission (odds ratio, 0.90 [95% CI, 0.87-0.92]; P<0.001). Conclusions Women are more likely to undergo TEVAR for aneurysms, while men are more likely to undergo TEVAR for type B aortic dissection. In-hospital mortality after TEVAR is comparable among men and women irrespective of indication. Female sex is independently associated with a reduced odds of 30-day readmission after TEVAR.

Clinical characteristics and outcomes of Stanford type B aortic intramural hematoma: A single centre experience

Objective

To compare the clinical characteristics of Stanford type B aortic intramural hematoma (IMH) and Stanford type B aortic dissection (AD), and to identify the differences between thoracic endovascular aortic repair (TEVAR) and medical management (MM) in the Stanford type B IMH patients.

Methods

A retrospective observational study was conducted in patients treated between January 2015 and December 2016. The clinical characteristics and CT images of patients with type B IMH and type B AD were compared, and the clinical characteristics and CT images of patients in the type B IMH group who were treated with TEVAR and MM were compared.

Results

A total of 176 patients were included in this study, including 62 patients of type B IMH and 114 patients of type B AD. Five patients died in the IMH group and three in the AD group. The proximal hematoma or entry tear in both groups was mainly located in the descending aorta, and the proportion of the iliac artery involved in the AD group was significantly higher than that in the IMH group (31.6% vs. 8.1% P < 0.05). There were 50 MM patients and 12 TEVAR patients in the IMH group. No death occurred in the TEVAR group, while five patients in the MM group died. Seven patients in the MM group had disease progression vs. 12 in the TEVAR group (P < 0.05). The patients in the TEVAR group had more intima lesions than those in the MM group (83.3% vs. 30.0%, P < 0.05). TEVAR group involved more iliac artery hematoma than MM group (33.3% vs. 2.0%, P < 0.05). The maximum thickness of hematoma in TEVAR group was 14.9 ± 3.4 mm, which was significantly larger than that of MM group (10.2 ± 2.8 mm) (P < 0.05).

Conclusion

In the diagnosis of IMH, patients' symptoms and high-risk signs of CTA should be paid attention to. TEVAR therapy should be actively considered on the basis of effective medical management when there are intima lesions (ULP/PAU), increased aortic diameter and hematoma thickness, extensive hematoma involvement, and pleural effusion.

A Rare Initial Presentation of Aortic Intramural Hematoma: A Case Report and Literature Review

Aortic intramural hematoma (AIH) is a life-threatening emergency that involves aortic wall integrity and is characterized by either a direct rupture of the vasa vasorum or spontaneous bleeding of an arterial plaque located in the tunica media of the aortic wall. A notable difference between AIH and acute aortic dissection is the absence of an intimal flap, a finding discernable on computed tomography angiography (CTA). Follow-up imaging allows for the monitoring of disease progression or early findings of impending complications. While some patients may require surgical intervention, medical management with blood pressure control remains the mainstay in treatment. Our case describes a patient who was found to be in cardiac arrest secondary to ventricular fibrillation and was then found to have presumed Stanford Type A aortic dissection on CTA. After reviewing the scans, the diagnosis was reclassified to AIH due to the absence of an intimal flap, the patient was then managed medically for AIH with antihypertensive medications.

Successful medical treatment of aortic intramural hematoma (Stanford type B) in a patient with aberrant right subclavian artery: A case report

Intramural Hematoma (IMH) forms part of the acute aortic syndrome, aortic dissection, and penetrating aortic ulcer. It is a life-threatening aortic disease that warrants prompt diagnosis and management. Like aortic dissections, it is classified using the Stanford classification system as type A (proximal to the origin of the left subclavian artery) and type B (distal to the origin of the left subclavian artery). Patients with type A IMH is generally managed surgically, and uncomplicated type B IMH is managed medically. The right subclavian artery arises typically from the brachiocephalic trunk. Aberrant right subclavian arteries (ARSA) are rare and derive directly from the aortic arch distal to the left subclavian artery. In this case report, a 73-year-old female presented with right-sided chest pain and shortness of breath. On examination, her heart rate was 100 bpm and blood Pressure was 185/85 and her ECG showed sinus rhythm. Following a CT scan, she was found to have a type B Aortic IMH with an ARSA. She was medically managed with vigorous blood pressure control. After a period of intravenous blood pressure treatment, she was treated with oral medication. Her subsequent CT scan showed that the hematoma was stable. She was followed up with MRI scanning 1 year later, which showed complete healing of the aorta with no changes in diameter. This case illustrates the importance of strict blood pressure management and follow-up imaging in patients presenting with type B IMH. It is important to monitor these patients regularly and where blood pressure control alone is not sufficient, further intervention may be required. Even though the complete resolution may be achieved as in this case, these patients will need to be kept under surveillance with repeated scans to monitor for any changes.

Misdiagnosis of Thoracic Aortic Emergencies Occurs Frequently Among Transfers to Aortic Referral Centers: An Analysis of Over 3700 Patients

Background Acute aortic syndromes may be prone to misdiagnosis by nonreferral aortic centers with less diagnostic experience. We evaluated regional variability in these misdiagnosis trends among patients transferred to different regional quaternary care centers with presumed acute aortic syndromes. Methods and Results Two institutional aortic center databases were retrospectively reviewed for emergency transfers in patients diagnosed with acute aortic dissection, intramural hematoma, penetrating aortic ulcer, thoracic aortic aneurysm, or aortic pseudoaneurysm between 2008 and 2020. Transferring diagnoses versus actual diagnoses were reviewed using physician notes and radiology reports. Misdiagnoses were confirmed by a board-certified cardiothoracic surgeon. A total of 3772 inpatient transfers were identified, of which 1762 patients were classified as emergency transfers. The mean age was 64 years (58% male). Patients were transferred from 203 medical centers by ground (51%) or air (49%). Differences in transfer diagnosis and actual diagnosis were identified in 188 (10.7%) patients. Of those, incorrect classification of Type A versus B dissections was identified among 23%, and 30% of patients with a referring diagnosis of an acute aortic dissection did not have one. In addition, 14% transferred for contained/impending rupture did not have signs of rupture. All misdiagnoses were secondary to misinterpretation of imaging, with motion artifacts (n=32, 17%) and postsurgical changes (n=44, 23%) being common sources of diagnostic error. Conclusions Misdiagnosis of acute aortic syndromes commonly occurred in patients transferred to 2 separate large aortic referral centers. Although diagnostic accuracy may be improving, there are opportunities for improved physician awareness through standardized web-based imaging education.

Endovascular repair of the aortic arch: State of the art

BACKGROUND

Open total arch replacement remains the gold standard treatment for aneurysms and dissections involving the aortic arch. However, high-risk surgical candidates may benefit from endovascular techniques to reduce the risk of perioperative mortality and morbidity, especially neurologic complications. Numerous endografts are available for investigational use in the aortic arch as part of investigational device exemption (IDE) programs. Some devices are fenestrated or scalloped, while others are branched, ranging from single branch to triple branch stent-grafts. Furthermore, chimney techniques and in situ fenestration may be utilized in bailout or emergent situations.

RESULTS

Initial results describing outcomes of complete endovascular repair of the aortic arch are encouraging, with current data estimating that technical success ranges from 84.2% to 100%. Moreover, operative mortality may be as high as 13.2%, while neurologic complications also remain common, with stroke rates being as high as 20% and spinal cord ischemia being as high as 3.1%. However, more data are necessary to determine the comparative treatment effect of endovascular stent-grafting of the aortic arch, compared with conventional open and hybrid repairs. Longitudinal follow-up is also lacking, which will determine the long-term durability of endografts in the aortic arch. Nevertheless, endovascular repair represents an important opportunity for improving outcomes in patients with complex and potentially devastating pathologies of the aortic arch.

Intraoperative neurophysiologic monitoring during aortic arch surgery

OBJECTIVE

To evaluate the ability of intraoperative neurophysiologic monitoring (IONM) during aortic arch reconstruction with hypothermic circulatory arrest (HCA) to predict early (<48 hours) adverse neurologic events (ANE; stroke or transient ischemic attack) and operative mortality.

METHODS

This was an observational study of aortic arch surgeries requiring HCA from 2010 to 2018. Patients were monitored with electroencephalogram (EEG) and somatosensory evoked potentials (SSEP). Baseline characteristics and postoperative outcomes were compared according to presence or absence of IONM changes, which were defined as any acute variation in SSEP or EEG, compared with baseline. Multivariable logistic regression analysis was used to assess the association of IONM changes with operative mortality and early ANE.

RESULTS

A total of 563 patients underwent aortic arch reconstruction with HCA and IONM. Of these, 119 (21.1%) patients had an IONM change, whereas 444 (78.9%) did not. Patients with IONM changes had increased operative mortality (22.7% vs 4.3%) and increased early ANE (10.9% vs 2.9%). In multivariable analysis, SSEP changes were correlated with early ANE (odds ratio [OR], 4.68; 95% confidence interval [CI], 1.51-14.56; P = .008), whereas EEG changes were not (P = .532). Permanent SSEP changes were correlated with early ANE (OR, 4.56; 95% CI, 1.51-13.77; P = .007), whereas temperature-related SSEP changes were not (P = .997). Finally, any IONM change (either SSEP or EEG) was correlated with operative mortality (OR, 5.82; 95% CI, 2.72-12.49; P < .001).

CONCLUSIONS

Abnormal IONM events during aortic arch reconstruction with HCA portend worse neurologic outcomes and operative mortality and have a negative predictive value of 97.1%. SSEP might be more sensitive than EEG for predicting early ANE, especially when SSEP changes are permanent.