Outcomes of Open Repair for Chronic Descending Thoracic Aortic Dissection

Trends in the incidence, surgical management and outcomes of type B aortic dissections in Australia over the last decade

OBJECTIVES

This study aims to investigate the incidence and in-hospital outcomes of surgical repair for type B aortic dissection (TBAD) in Australia.

METHODS

Data were obtained from the Australasian Vascular Audit (AVA) and the Australian Institute of Health and Welfare (AIHW). The former is a total practice audit mandated for all members of the Australian and New Zealand Society for Vascular Surgery (ANZSVS) while the latter is an independent government agency which records all healthcare data in Australia. All cases of TBAD which underwent surgical intervention (endovascular or open repair) between 2010 and 2019 were identified using prospectively recorded data from the AVA (New Zealand data was excluded). The primary outcomes were temporal trends in procedures and hospital mortality; secondary outcomes were complications and risk factors for mortality. All admissions and procedures for, and hospital deaths from, TBAD in Australia were identified in AIHW datasets using the relevant diagnosis and procedure codes, with age-standardized rates calculated for the period 2000-01 to 2018-19.

RESULTS

A total of 567 cases of TBAD underwent vascular surgical intervention (AVA data, Australia). Of these, 96.3% were treated by endovascular repair. There was an increase in the annual procedure number from 45 in 2010 to 88 in 2019. In-hospital mortality was 4.8% for endovascular repair and 19% for open repair (p = 0.021). From 2000-01 to 2018-19, the age-standardized procedure rates for TBAD (Australia) doubled, the proportion of admitted patients undergoing a procedure rose from 28% to 43%, and in-hospital deaths fell by 25%.

CONCLUSION

There has been an increasing incidence of vascular surgical intervention for TBAD in Australia. The majority of patients received endovascular therapy while the mortality from surgically managed TBAD appears to be falling.

Comparison of open thoracoabdominal repair for chronic aortic dissections and aneurysms

OBJECTIVE

Aortic dissection is common in patients undergoing open surgical repair of thoracoabdominal aortic aneurysms (TAAAs). Most often, dissection is chronic and is associated with progressive aortic dilatation. Because contemporary outcomes in chronic dissection are not clearly understood, we compared patient characteristics and outcomes after open TAAA repair between patients with chronic dissection and those with non-dissection aneurysm.

METHODS

We retrospectively analyzed data from 3470 open TAAA repairs performed in a single practice. Operations were for non-dissection aneurysm in 2351 (67.8%) and chronic dissection in 1119 (32.2%). Outcomes included operative mortality and adverse events, a composite variable comprising operative death and persistent (present at discharge) stroke, paraplegia, paraparesis, and renal failure necessitating dialysis. Logistic regression identified predictors of operative mortality and adverse events. Time-to-event analyses examined survival, death, repair failure, subsequent progressive repair, and survival free of failure or subsequent repair.

RESULTS

Compared with patients with non-dissection aneurysm, those with chronic dissection were younger, had fewer atherosclerotic risk factors, and were more likely to have heritable thoracic aortic disease and undergo extent II repair. The operative mortality rate was 8.5% (n = 296) overall and was higher in non-dissection aneurysm patients (n = 217; 9.2%) than in chronic dissection patients (n = 79; 7.1%; P = .03). Adverse events were less frequent (P = .01) in patients with chronic dissection (n = 145; 13.0%), 22 (2.0%) of whom had persistent paraplegia. Chronic dissection was not predictive of operative mortality (P = .5) or adverse events (P = .6). Operative mortality and adverse events, respectively, were independently predicted by emergency repair (odds ratio [OR], 3.46 and 2.87), chronic kidney disease (OR, 1.74 and 1.81), extent II TAAA repair (OR, 1.44 and 1.73), increasing age (OR, 1.04/year and 1.04/year), and increasing aortic cross-clamp time (OR, 1.02/minutes and 1.02/minutes). Patients with chronic dissection had lower 10-year unadjusted mortality (42% vs 69%) but more frequent repair failure (5% vs 3%) and subsequent repair for progressive aortic disease (11% vs 5%) than patients with non-dissection aneurysm (P < .001); these differences were no longer statistically significant after adjustment.

CONCLUSIONS

Outcomes of open TAAA repair vary by aortic disease type. Emergency repairs and atherosclerotic diseases most commonly occur in patients with non-dissection aneurysm and independently predict operative mortality. Repair of chronic dissection is associated with low rates of adverse events, including operative mortality and persistent paraplegia, along with reasonable late survival and good durability. However, patients with chronic dissection tend to more commonly undergo subsequent repair to treat progressive aortic disease, which emphasizes the need for robust long-term imaging surveillance protocols.

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Open surgical replacement of the descending aorta: single-center experience

Background

This study presents a single center's experience and analyzes clinical outcomes following elective open surgical descending aortic replacement.

Methods

Between January 2000 and August 2019, 96 patients with mean age 64 years (range, 49.5-71 years) (62.5% (n=60) male) underwent elective descending aortic replacement due to aneurysm (n=60) or chronic dissection (n=36). Marfan syndrome was present in 12 patients (12.5%).

Results

In-hospital mortality rate was 3.1% (n= 3. 2 in the aneurysm group, 1 in the dissection group). New-onset renal insufficiency postoperatively with (creatinine ≥ 2.5 mg/dl) manifested in 10 patients (10.8%). One patient (1%) suffered from stroke, and paraplegia developed in 1 pts (1%). The median follow-up time was 7 years (IQR: 2.5-13 years). The 5- and 10-year survival rates were 70.8% and 50.7% respectively. We did not observe any early or late prosthetic graft infection. The Cox proportional hazards regression analysis identified age (HR: 1.044, 95% CI: 1.009-1.080, p-value: 0.014), diabetes (HR: 2.544, 95% CI: 1.009-6.413, p-value: 0.048), and chronic obstructive pulmonary disease (COPD) (HR: 2.259, 95% CI: 1.044-4.890, p-value: 0.039) as risk factors for late mortality.

Conclusions

This study showed that the elective open surgical replacement of the descending aorta can be achieved with excellent outcomes in terms of perioperative mortality and morbidity. Prosthetic graft is not a problem with open surgical descending aortic replacement, even in the long term.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-022-01443-x.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

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

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

Surgical strategies in the management of chronic dissection of the thoracoabdominal aorta

Most operations for dissection of the thoracoabdominal aorta take place in the chronic phase of the disease, because the acutely dissected distal aorta is almost always initially treated non-surgically with aggressive pharmacological anti-impulse therapy. Identifying patients who are no longer responding to medical treatment is the first step in preventing further disease progression and rupture. Symptomatic aneurysms should be promptly repaired. Asymptomatic patients are followed until significant aortic dilation occurs and reaches a threshold of intervention: current guidelines endorse repair once a diameter of 5.5 cm is reached. In patients with heritable thoracic aortic disease (such as Marfan Syndrome), the threshold of intervention is often lowered. Aortic replacement typically centers on the dilatated segment. For all extents of repair, we use passive mild hypothermia, sequential aortic cross-clamping, aggressive reimplantation of intercostal and lumbar arteries, and cold renal perfusion whenever possible. For Crawford extents I and II thoracoabdominal aneurysm repair, we routinely use cerebrospinal fluid drainage, left heart bypass, and selective visceral perfusion. A four-branched graft approach to thoracoabdominal aortic aneurysm repair is frequently used in patients with chronic aortic dissection; this approach facilitates visceral artery perfusion during repair, expedites the distal anastomosis, and prevents subsequent visceral patch aneurysms. Lifelong imaging surveillance is necessary, because the distal aorta often continues to expand; residual aortic dissection commonly remains after repair and may necessitate further repair.

Endovascular Repair of Postdissection Aortic Aneurysms Using Physician-Modified Endografts

BACKGROUND

The purpose of this study was to report our experience and evaluate the technical and clinical outcomes of physician-modified endovascular aortic repair of chronic postdissection thoracoabdominal aortic aneurysms.

METHODS

A retrospective analysis of prospectively collected data of consecutive patients presenting with chronic postdissection aneurysms unfit for open surgery and treated by physician-modified stent grafts between January 2016 and December 2019 was conducted. Outcome data were collected retrospectively. Early outcomes included technical success, perioperative mortality, and major adverse events. Late outcomes included reintervention, false lumen thrombosis rate, aneurysm size regression, and survival.

RESULTS

Sixty-two patients (80.1% men with a mean age of 64 ± 9.9 years) were treated. The technical success was 98.3%. There was 1 (1.6%) death within 30 days. Perioperative major adverse events included respiratory failure (1.6%), spinal cord injury (0%), acute kidney injury (3.2%; 1 dialysis), bowel ischemia (1.6%), myocardial infarction (1.6%), and lower limb ischemia (1.6%). A reintervention was required in 6 (9.8%) patients. The false lumen thrombosis rates were 91.8% (n = 45 of 49) at 1-year follow-up. One patient died during follow-up from an aneurysm-related cause. The estimated overall survival rates were 98.4% and 96.8% at 6 months and 12 months, respectively.

CONCLUSIONS

The report confirmed the feasibility and safety of fenestrated and branched endovascular aortic repair in the setting of postdissection thoracoabdominal aortic aneurysms. Despite the associated perioperative risk and high probability of intended or unintended reintervention, the procedure could lead to favorable aortic remodeling.

Clinical and Morphologic Outcomes of Endovascular Repair for Subacute and Chronic Type B Aortic Dissection

BACKGROUND

The objective of the study was to assess long-term remodeling, survival, and reintervention outcomes after thoracic endovascular aortic repair (TEVAR) for subacute and chronic type B aortic dissection (TBAD).

METHODS

All patients who underwent TEVAR for subacute or chronic TBAD at a tertiary referral center between 1999 and 2015 were included in this cohort study. The primary outcome was aortic remodeling, and secondary outcomes included survival, rate of major complications, and reinterventions.

RESULTS

Fifty patients were included, with mean age of 62.4 years, 10 (20%) DeBakey type IIIA and 40 (80%) DeBakey type IIIB dissection; 45 standard TEVAR, 2 branched TEVAR, 3 TEVAR combined with fenestrated or branched EVAR. Indication for TEVAR was intact (n = 40) or ruptured (n = 1) postdissection aneurysm, hypoperfusion (n = 4), treatment-refractory pain (n = 2), or a combination (n = 3). Mean clinical follow-up was 76 months, and median radiological follow-up was 46 months. Thirty-day survival was 96%, stroke 4%, renal failure 0%, paraplegia 0%. Three- and five-year survival was 92% (95% confidence interval (CI) [79; 97]) and 77% (95% CI [61; 87]), respectively. Of 19 late deaths, 6 were confirmed aorta related. Five-year freedom from reintervention was 69% (95% CI [53-80]). Distal stent graft extension due to aortic dilatation composed most reinterventions. Mean maximal aortic diameter was 58.7 mm preoperatively and 51.9 mm on last follow-up (P = 0.003). On thoracic level, true lumen expanded (+10.0 mm, 95% CI [6.4; 13.6]) (P < 0.001) and false lumen decreased (-11.9 mm, 95% CI [-15.2; -8.5]) (P < 0.001) from baseline to the last computed tomography. In the abdominal aorta, true lumen diameter change was +3.1 mm (95% CI [1.4; 4.8]) (P = 0.001); false lumen diameter change was +1.0 mm (95% CI [-1.8; 3.8]) (P = 0.464).

CONCLUSIONS

TEVAR for subacute and chronic TBAD results in favorable remodeling of the thoracic but not the abdominal aorta. Five-year survival is almost 80%, but late aortic deaths still occur. Aortic dilatation distal to the treated segment requiring reintervention is common, emphasizing the importance of follow-up.

Cause-specific mortality of type B aortic dissection and assessment of competing risks of mortality

OBJECTIVE

Natural history studies of type B aortic dissection (TBAD) commonly report all-cause mortality. Our aim was to determine cause-specific mortality in TBAD and to evaluate the clinical characteristics associated with aorta-related and nonaorta-related mortality.

METHODS

Clinical and administrative records were reviewed for patients with acute TBAD between 1995 and 2017. Demographics, comorbidities, presentation, and initial imaging findings were abstracted. Cause of death was ascertained through a multimodality approach using electronic health records, obituaries, social media, Social Security Death Index, and state mortality records. Causes of death were classified as aorta related, nonaorta related, or unknown. A Fine-Gray multivariate competing risk regression model for subdistribution hazard ratio was employed to analyze the association of clinical characteristics with aorta-related and nonaorta-related mortality.

RESULTS

A total of 275 individuals met inclusion criteria (61.1 ± 13.7 years, 70.9% male, 68% white). Mean survival after discharge was 6.3 ± 4.7 years. Completeness of follow-up Clark C index was 0.87. All-cause mortality was 50.2% (n = 138; mean age, 70.1 ± 14.6 years) including an in-hospital mortality of 8.4%. Cause-specific mortality was aorta related, nonaorta related, and unknown in 51%, 43%, and 6%, respectively. Compared with patients with nonaorta-related mortality, patients with aorta-related mortality were younger at acute TBAD (69.5 ± 11.2 years vs 61.6 ± 15.5 years; P = .001), underwent more descending thoracic aortic repairs (19.4% vs 45.8%; P = .002), and had a shorter survival duration (5.7 ± 3.9 vs 3.4 ± 4.5 years; P = .002). There was clear variation in cause of death by each decade of life, with higher aorta-related mortality among those younger than 50 years and older than 70 years and a stepwise increase in nonaorta-related mortality with each increasing decade (P < .001). All-cause mortality at 1 year, 3 years, and 10 years was 15%, 24%, and 57%, respectively. After accounting for competing risks, the cumulative incidence of aorta-related mortality at 1 year, 3 years, and 10 years was 8.9%, 16.5%, and 27.2%, respectively, and that of nonaorta-related mortality was 2.7%, 7.2%, and 29%, respectively. A maximum descending thoracic aortic diameter >4 cm was associated with an increase in hazard of aorta-related mortality by 84% (subdistribution hazard ratio, 1.84; 95% confidence interval, 1.03-3.28) on multivariate competing risk regression analysis.

CONCLUSIONS

TBAD is associated with high 10-year mortality. Those at risk for aorta-related mortality have a clinical phenotype different from that of individuals at risk for nonaorta-related mortality. This information is important for building risk prediction models that account for competing mortality risks and to direct optimal and individualized surgical and medical management of TBAD.

Long-term Results of Thoracic Endovascular Aortic Repair for Type B Aortic Dissection and Risk Factors for Survival

Purpose: To compare characteristics of acute, subacute, and chronic type B aortic dissection and their influence on long-term results of thoracic endovascular aortic repair (TEVAR). Materials and Methods: In a single-center, retrospective cohort study, 314 patients (median age 52 years; 244 men) with acute (n=165), subacute (n=115), or chronic (n=34) type B aortic dissection underwent TEVAR between January 2009 and December 2013. Patient demographics, risk factors, and imaging characteristics were compared among the groups. Univariable and multivariable Cox regression analyses were performed to identify any factors influencing survival. Results: The acute and subacute patients exhibited more complications at presentation than chronic patients. However, the chronic patients exhibited more aneurysmal dilatation (p<0.001) and true lumen collapse (p<0.001). Over a mean follow-up of 68.1±22.9 months (range 2–108), subacute patients showed a lower reintervention rate (3.6% vs 12.1% vs 12.1%, p=0.045), a lower major complication rate (14.4% vs 33.1% vs 27.3%, p=0.002), and better cumulative overall survival (p=0.03) than the acute and chronic groups, respectively. Furthermore, acute patients developed more stent-graft–induced distal erosion (p=0.017) and retrograde type A dissection (RTAD) (p=0.036), whereas chronic patients had less aortic remodeling in the stented segment (p<0.001), distal thoracic aorta (p<0.001), and abdominal aorta (p=0.047). Finally, multivariable analysis demonstrated age >52 years, visceral malperfusion, and RTAD as independent factors influencing overall survival; aneurysmal dilatation, rupture/impending rupture, and RTAD were independent factors influencing aorta-specific survival. Conclusion: Acute and subacute patients had increased risks of rupture and complications at presentation, whereas chronic patients had increased risks for aneurysmal dilatation. From a long-term perspective, the subacute phase might be an optimal time for TEVAR in cases of type B aortic dissection that do not need emergent interventions. The risk factors influencing survival should be identified, carefully managed, and possibly prevented.

Replacement of the descending thoracic aortic aneurysm with partial cardiopulmonary bypass in the era of endovascular repair

OBJECTIVES

Although the advent of thoracic endovascular aortic repair (TEVAR) has provided an alternative treatment option for descending thoracic aortic aneurysm (DTAA), open repair still plays a crucial role in DTAA repair. The purpose of this study was to re-evaluate the operative and long-term outcomes of open repair with partial cardiopulmonary bypass, compared to the results of TEVAR with a proximal landing zone of 3 or 4.

METHODS

Between 2007 and 2017, open repair was performed for 44 patients and TEVAR for 282 patients. Acute aortic dissection and open proximal anastomosis under circulatory arrest were excluded. Perioperative and long-term follow-up data were analyzed.

RESULTS

In-hospital mortality rate (4.5% vs 3.2%, p = 0.42), and frequencies of spinal cord injury and neurological deficit showed no significant differences between the open repair and TEVAR groups (p = 0.41, 0.25, respectively). The propensity score-matched analysis showed similar cumulative survival (p = 0.23), but significantly higher reintervention rates for the repaired segment in the TEVAR group than in the open repair group (p = 0.0054). Twenty-two (7.8%) TEVAR patients required re-interventions for the repaired segment. Of those, 17 patients underwent additional TEVAR and 5 patients needed open conversion surgery with partial cardiopulmonary bypass. Reintervention rates for the repaired segment were significantly higher in the TEVAR group than in the open repair group (p = 0.012).

CONCLUSIONS

Open repair DTAA using partial cardiopulmonary bypass showed operative outcomes comparable to TEVAR and lower reintervention rates, and thus remains an acceptable procedure for selected patients in this era of endovascular repair.

Open surgical repair of post-dissection thoraco-abdominal aortic aneurysms: early and late outcomes of a single-centre study involving over 200 patients

OBJECTIVES

Chronic, post-dissection thoraco-abdominal aortic aneurysms (TAAAs) are increasingly being treated by (hybrid) endovascular means. Although it is less invasive, thoracic endovascular aortic repair is technically complex with the risk of incomplete aneurysm exclusion, necessitating frequent reinterventions with potentially reduced long-term outcomes. The aim of this study was to evaluate contemporary early and late outcomes after open surgical repair of post-dissection TAAA.

METHODS

At our centre, 633 patients underwent open repair for TAAA over a 20-year period (1994-2015), including 217 (34%) patients for post-dissection TAAA, who were included in this analysis. Circulatory support was obtained by either left heart bypass (173 patients, 79.7%), deep hypothermic circulatory arrest (41 patients, 18.9%) or simple aortic cross-clamping in 3 patients. We analysed all relevant perioperative and intraoperative variables with respect to adverse outcomes. Additionally, long-term survival and the need for aortic reinterventions were studied.

RESULTS

The mean age was 60.2 ± 11.9 years (men 68.2%). We identified 66 Type I (30.4%), 113 Type II (52.1%), 25 Type III (11.5%), 10 Type IV (4.6%) and 3 Type V (1.4%) TAAAs. Early mortality and spinal cord deficit were 5.9% and 5.5%, respectively. Follow-up was 100% complete (mean 6.0 ± 5.8 years), with long-term survival of 71.4% at 10 years, and freedom from death and reoperation was 68.2% at 10 years.

CONCLUSIONS

Although it is more invasive than current endovascular approaches for post-dissection TAAA, open surgical repair can be performed safely with acceptable rates of morbidity and mortality when it is done in a specialized aortic centre. Long-term survival and freedom from aortic reintervention are excellent and should also be taken into account when evaluating less invasive alternatives.

Impact of hybrid thoracoabdominal aortic repair on visceral and spinal cord perfusion: The new and improved SPIDER-graft

OBJECTIVES

SPIDER-graft for thoracoabdominal aortic aneurysm repair avoiding thoracotomy and extracorporeal circulation was modified, enabling reimplantation of lumbar arteries to prevent spinal cord ischemia and compared with open aortic repair (control) in a pig model.

METHODS

Graft implantation was performed in 7 pigs per group (75-85 kg). For SPIDER-graft (groups I and II), the infra-diaphragmatic aorta was exposed through retroperitoneal access. The right iliac branch was first temporarily anastomosed end-to-side to the distal aorta maintaining periprocedural retrograde visceral perfusion. SPIDER-graft was deployed in the descending thoracic aorta via the celiac artery ostium. The celiac, superior mesenteric, and renal arteries were successively connected to the corresponding side branches of the graft. In group II, the lumbar arteries were reimplanted into the former access branch. For control, complete thoracoabdominal exposure of the aorta was required. After crossclamping, proximal anastomosis was performed, and the celiac artery, superior mesenteric artery, renal arteries, and iliac arteries were reattached. Technical feasibility, ischemic times, blood flow, and visceral and spinal cord perfusion in the related organs were evaluated before implantation and 3 and 6 hours after implantation using transit-time flow measurement and fluorescent microspheres.

RESULTS

Technical success was achieved in all animals in all groups. Total aortic clamping time and selective ischemic times of related organs were significantly longer during open aortic repair compared with groups I and II (P < .0001). Fluorescent microspheres confirmed best spinal cord perfusion in group II.

CONCLUSIONS

SPIDER-graft reduced ischemic time, avoided extracorporeal circulation and thoracotomy, and improved spinal cord perfusion during thoracoabdominal aortic aneurysm repair in a pig model.

Surgery for Acute Presentation of Thoracoabdominal Aortic Disease

Thoracoabdominal aortic aneurysms are most commonly asymptomatic until there is either an impending aortic catastrophe or one that has already occurred. While open surgery remains the gold-standard method for repair, modern technology has led to the development of less invasive endovascular devices and techniques. We provide an expert review of open and endovascular therapies for 3 highly lethal thoracoabdominal aortic emergencies in order to highlight expectations for both short- and long-term outcomes in an era of evolving technology and improvements in patient evaluation and postoperative care. Open repair of ruptured thoracoabdominal aortic aneurysms is associated with a dramatic increase in all postoperative complications, even in specialized aortic surgery centers. Mycotic thoracic aortic aneurysms are highly lethal if surgical treatment is not initiated quickly as they have a propensity toward rapid growth and fatal rupture. Thoracic endovascular aortic repair is well-suited for the treatment of acute complicated type B aortic dissection with outcomes superior to open repair in some centers. Acute aortic events associated with thoracoabdominal aneurysms represent technically challenging situations that require rapid diagnosis and treatment to avoid a fatal outcome. Endovascular techniques have evolved as a viable alternative therapy for acute complicated type B aortic dissection or as a bridge to more definitive repair in the setting of infection or rupture.

State-of the-art review on the renal and visceral protection during open thoracoabdominal aortic aneurysm repair

During open thoracoabdominal aortic aneurysm repair (OTAAAR), there is an inevitable organ ischemic period that occurs when the abdominal arteries are being reattached to the aortic graft. Despite various protective techniques, the incidence of renal and visceral complications remains substantial. This state-of-the-art review gives an overview of the current and most evidence-based organ protection methods during OTAAAR, based on the most recent publications and personal experience. An electronic search was performed in four medical databases, using the following MeSH terms: thoracoabdominal aneurysm, TAAAR, visceral protection, renal protection, kidney, perfusion, and intestines. Every publication type was considered. The literature search was ended on August 31st, 2017. The left heart bypass (LHB) is currently the most frequent adjunct to provide distal aortic perfusion (DAP) during aortic clamping. Together with systemic hypothermia, it forms the cornerstone in organ protection during aortic clamping. Further renal protection can be obtained by selective renal perfusion (SRP) with cold blood or cold crystalloid solution, the latter enriched with mannitol. The perfusion should be administered in a volume- and pressure-controlled way and, if possible, by use of a pulsatile pump. Selective visceral perfusion (SVP) is not routinely used, as it does not provide adequate blood flow for visceral protection. The best way to protect the intestines is by minimizing the ischemic time. The preservation of renal and visceral function after OTAAAR can only be obtained with specific strategies before, during, and after the operation. This involves a series of measures, including selective digestive decontamination (SDD), avoidance of nephrotoxic drugs, minimizing the renal and intestinal ischemic time, systemic cooling, avoidance of hemodynamic instability, and regional protective perfusion of the kidneys. Future innovations in catheters, cardiac bypass flow types, mechanical components, hybrid vascular grafts, and pharmaceutical protection measures will hopefully further reduce organ complications.

Feasibility Study of a Novel Thoraco-abdominal Aortic Hybrid Device (SPIDER-graft) in a Translational Pig Model

BACKGROUND

The hybrid SPIDER-graft consists of a proximal descending aortic stent graft and a conventional six branched Dacron graft for open abdominal aortic repair. Technical feasibility with regard to avoiding thoracotomy and extracorporeal circulation (ECC) during thoraco-abdominal aortic hybrid repair and peri-procedural safety of this novel device are unknown.

MATERIAL AND METHODS

This was a feasibility and safety study in domestic pigs (75-85 kg). The abdominal aorta including iliac bifurcation, left renal artery, and visceral arteries were exposed via retroperitoneal access. The right iliac branch was first temporarily anastomosed end to side to the distal aorta via partial clamping. During inflow reduction and infra-coeliac cross-clamping, the coeliac trunk (CT) was divided and the proximal stent graft portion of the SPIDER-graft was deployed into the descending aorta via the CT ostium. Retrograde visceral and antegrade aorto-iliac blood flow was maintained via the iliac side branch. The visceral, renal, and iliac arteries were sequentially anastomosed, finally replacing the first iliac end to side anastomosis. Technical success, blood flow, periods of ischaemia, and peri-procedural complications were evaluated after intra-operative completion angiography and post-operative computed tomography angiography.

RESULTS

Six animals underwent successful thoracic stent graft deployment and distal open reconstruction without peri-operative death. The median thoracic graft implantation time was 4.5 min, and the median ischaemia times before reperfusion were 10 min for the CT, 8 min for the superior mesenteric artery, 13 min for the right renal artery, and 22 min for the left renal artery. Angiography demonstrated appropriate graft implantation and blood flow measurements confirmed sufficient blood flow through all side branches.

CONCLUSION

In this translational pig model, thoraco-abdominal hybrid repair using the novel SPIDER-graft was successful in avoiding thoracotomy and ECC. Technical feasibility and safety appear promising, but need to be reassessed in humans.

Risk Modeling to Optimize Patient Selection for Management of the Descending Thoracic Aortic Aneurysm

BACKGROUND

A single-institutional study comparing early and long-term outcomes of thoracic endovascular aortic repair (TEVAR) and open surgical repair (OSR) was performed to determine the appropriate treatment option for descending thoracic aortic aneurysm (DTAA).

METHODS

Between 2005 and 2014, 438 DTAA patients were treated (TEVAR, 88; OSR, 350). Acute dissection and traumatic injury were excluded. Perioperative and follow-up data were reviewed. Stratified analyses were conducted to identify patients most likely to benefit from TEVAR. A propensity score for TEVAR was developed by logistic regression, and predictive logistic and Cox regression models for death were adjusted for propensity score.

RESULTS

TEVAR patients were frequently older women with emergent status, chronic obstructive pulmonary disease, or coronary artery disease. TEVAR had similar immediate (0% vs 1%; p = 0.588) and delayed (5% vs 6%, p = 1.000) motor deficits and early mortality (6% vs 12%, p = 0.121) but lower dialysis (3% vs 18%, p < 0.001), respiratory failure (10% vs 34%, p < 0.001), and intensive care unit stay (2.0 vs 5.0 days, p < 0.001). Early mortality after TEVAR was lower in septuagenarians (3% vs 16%, p < 0.02), glomerular filtration rate of less than 60 mL/min (8% vs 32%, p < 0.049), chronic obstructive pulmonary disease (6% vs 21%, p < 0.02), defined as target population that had fourfold mortality reduction (p < 0.006) attributable to TEVAR. Propensity-adjusted predictors of early mortality predictors included OSR (odds ratio [OR], 4.3; p < 0.024), target population (OR, 7.7; p < 0.001), diabetes (OR, 3; p < 0.009), peripheral vascular disease (OR, 4.7; p < 0.001), and emergent status (OR, 4.6; p < 0.001). Propensity-adjusted determinants of survival were age, glomerular filtration rate of less than 60 mL/min, peripheral vascular disease, chronic obstructive pulmonary disease, and emergent status.

CONCLUSIONS

In older patients with significant comorbidities, TEVAR demonstrated superior results compared with OSR and may be preferable in this target population.

Prognostic significance of early aortic remodeling in acute uncomplicated type B aortic dissection and intramural hematoma

BACKGROUND

Patients with Stanford type B aortic dissections (ADs) are at risk of long-term disease progression and late complications. The aim of this study was to evaluate the natural course and evolution of acute type B AD and intramural hematomas (IMHs) in patients who presented without complications during their initial hospital admission and who were treated with optimal medical management (MM).

METHODS

Databases from 2 aortic centers in Europe and the United States were used to identify 136 patients with acute type B AD (n = 92) and acute type B IMH (n = 44) who presented without complications during their index admission and were treated with MM. Computed tomography angiography scans were available at onset (≤14 days) and during follow-up for those patients. Relevant data, including evidence of adverse events during follow-up (AE; defined according to current guidelines), were retrieved from medical records and by reviewing computed tomography scan images. Aortic diameters were measured with dedicated 3-dimensional software.

RESULTS

The 1-, 2-, and 5-year event-free survival rates of patients with type B AD were 84.3% (95% confidence interval [CI], 74.4-90.6), 75.4% (95% CI, 64.0-83.7), and 62.6% (95% CI, 68.9-73.6), respectively. Corresponding estimates for IMH were 76.5% (95% CI, 57.8-87.8), 76.5% (95% CI, 57.8-87.8), and 68.9% (95% CI, 45.2-83.9), respectively. In patients with type B AD, risk of an AE increased with aortic growth within the first 6 months after onset. A diameter increase of 5 mm in the first half year was associated with a relative risk for AE of 2.29 (95% CI, 1.70-3.09) compared with the median 6 months' growth of 2.4 mm. In approximately 60% of patients with IMH, the abnormality resolved within 12 months and in the patients with nonresolving IMH, risk of an adverse event was greatest in the first year after onset and remained stable thereafter.

CONCLUSIONS

More than one third of patients with initially uncomplicated type B AD suffer an AE under MM within 5 years of initial diagnosis. In patients with nonresolving IMH, most adverse events are observed in the first year after onset. In patients with type B AD an early aortic growth is associated with a greater risk of AE.

Descending endografts for type A dissections: con

An important goal of surgical repair of type A aortic dissection is to resect the intimal tear. Studies on the fate of residual dissection after acute type A aortic dissection repair in the past decade have driven surgeons to seek procedures to avoid distal reoperation. Aggressive surgical approach with total arch replacement in acute type A dissection has demonstrated lower incidence of distal reoperation and slower aortic growth rate compared to less aggressive ascending/hemiarch repair. Recently, successful results of thoracic endovascular aortic repair (TEVAR) in type B aortic dissection have encouraged surgeons to further attack acute type A aortic dissection with hybrid approach: antegrade endografting in the descending thoracic true lumen as an adjunct to hemiarch or total arch repair. However, is the hybrid approach with simultaneous descending endografting justified in all the acute type A aortic dissection cases? The outcomes of the hybrid approach reported by the several groups have demonstrated 80-100% of false lumen thrombus formation in the proximal descending aorta (stented segment); however, the complete obliteration of the false lumen is only 17-50%. The incidence of distal reoperation/reintervention after hybrid approach is as high as 14% and an adjunctive procedure is often performed. Moreover, there are concerns about additional risks associated with the hybrid procedures, such as spinal cord injury (SCI), stent graft induced new entry and stroke. The data on this new approach are still very limited. Hence, further study is warranted to prove its safety and durability.

Contemporary Management Strategies for Chronic Type B Aortic Dissections: A Systematic Review

Background

Currently, the optimal management strategy for chronic type B aortic dissections (CBAD) is unknown. Therefore, we systematically reviewed the literature to compare results of open surgical repair (OSR), standard thoracic endovascular aortic repair (TEVAR) or branched and fenestrated TEVAR (BEVAR/FEVAR) for CBAD.

Methods

EMBASE and MEDLINE databases were searched for eligible studies between January 2000 and October 2015. Studies describing outcomes of OSR, TEVAR, B/FEVAR, or all, for CBAD patients initially treated with medical therapy, were included. Primary endpoints were early mortality, and one-year and five-year survival. Secondary endpoints included occurrence of complications. Furthermore, a Time until Treatment Equipoise (TUTE) graph was constructed.

Results

Thirty-five articles were selected for systematic review. A total of 1081 OSR patients, 1397 TEVAR patients and 61 B/FEVAR patients were identified. Early mortality ranged from 5.6% to 21.0% for OSR, 0.0% to 13.7% for TEVAR, and 0.0% to 9.7% for B/FEVAR. For OSR, one-year and five-year survival ranged 72.0%-92.0% and 53.0%-86.7%, respectively. For TEVAR, one-year survival was 82.9%-100.0% and five-year survival 70.0%-88.9%. For B/FEVAR only one-year survival was available, ranging between 76.4% and 100.0%. Most common postoperative complications included stroke (OSR 0.0%-13.3%, TEVAR 0.0%-11.8%), spinal cord ischemia (OSR 0.0%-16.4%, TEVAR 0.0%-12.5%, B/FEVAR 0.0%-12.9%) and acute renal failure (OSR 0.0%-33.3%, TEVAR 0.0%-34.4%, B/FEVAR 0.0%-3.2%). Most common long-term complications after OSR included aneurysm formation (5.8%-20.0%) and new type A dissection (1.7–2.2%). Early complications after TEVAR included retrograde dissection (0.0%-7.1%), malperfusion (1.3%–9.4%), cardiac complications (0.0%–5.9%) and rupture (0.5%–5.0%). Most common long-term complications after TEVAR were rupture (0.5%–7.1%), endoleaks (0.0%–15.8%) and cardiac complications (5.9%-7.1%). No short-term aortic rupture or malperfusion was observed after B/FEVAR. Long-term complications included malperfusion (6.5%) and endoleaks (0.0%-66.7%). Reintervention rates after OSR, TEVAR and B/FEVAR were 5.8%-29.0%, 4.3%-47.4% and 0.0%-53.3%, respectively. TUTE for OSR was 2.7 years, for TEVAR 9.9 months and for B/FEVAR 10.3 months.

Conclusion

We found a limited early survival benefit of standard TEVAR over OSR for CBAD. Complication rates after TEVAR are higher, but complications after OSR are usually more serious. Initial experiences with B/FEVAR show its feasibility, but long-term results are needed to compare it to OSR and standard TEVAR. We conclude that optimal treatment of CBAD remains debatable and merits a patient specific decision. TUTE seems a feasible and useful tool to better understand management outcomes of CBAD.