Midterm results of endovascular treatment of complicated acute type B aortic dissection

Early and Long-Term Follow-Up for Chronic Type B and Type Non-A Non-B Aortic Dissection Using the Frozen Elephant Trunk Technique

Background: This study aimed to evaluate the early and long-term outcomes of a single center using a frozen elephant trunk (FET) procedure for chronic type B or non-A non-B aortic dissection.

Methods: From February 2009 to December 2019, 79 patients diagnosed with chronic type B or non-A non-B aortic dissection who underwent the FET procedure were included in the present study. We analyzed operation mortality and early and long-term outcomes, including complications, survival and interventions.

Results: The operation mortality rate was 5.1% (4/79). Spinal cord injury occurred in 3.8% (3/79), stroke in 2.5% (2/79), and acute renal failure in 5.1% (4/79). The median follow-up time was 53 months. The overall survival rates were 96.2, 92.3, 88.0, 79.8, and 76.2% at 1/2, 1, 3, 5 and 7 years, respectively. Moreover, 79.3% of patients did not require distal aortic reintervention at 7 years. The overall survival in the subacute group was superior to that in the chronic group (P = 0.047).

Conclusion: The FET technique is a safe and feasible approach for treating chronic type B and non-A non-B aortic dissection in patients who have contraindications for primary endovascular aortic repair. The technique combines the advantages of both open surgical repair and endovascular intervention, providing comparable early and long-term follow-up outcomes and freedom from reintervention.

TEVAR for complicated and uncomplicated type B aortic dissection-Systematic review and meta-analysis

BACKGROUND

Type B aortic dissection (TBAD), is defined as a dissection involving the aorta distal to left subclavian artery with the ascending aorta and the aortic arch not affected. TBAD is classified due to the time frame and presence of complications. Complicated TBAD (co-TBAD) patients have a greater mortality rate than uncomplicated TBAD (un-TBAD) and thoracic endovascular aortic repair (TEVAR) is considered the gold-standard intervention for these clinical challenges.

METHODS

We undertook a systematic review of the literature regarding TEVAR intervention in co-TBAD and un-TBAD. A comprehensive search was undertaken across four major databases and was evaluated and assessed until June 2020.

RESULTS

A total of 16,104 patients were included in the study (7772 patients co-TBAD and 8352 un-TBAD). A significantly higher proportion of comorbidities were seen in co-TBAD patients compared with un-TBAD. Acute dissection was more frequent in the co-TBAD group (73.55% vs. 66.91%), while chronic dissection was more common in un-TBAD patients (33.8% vs. 70.73%). Postprocedure stroke was higher in co-TBAD (5.85% vs. 3.92%; p < .01), while postprocedural renal failure was higher in un-TBAD patients (7.23 vs. 11.38%; p < .01). No difference was observed in in-hospital mortality however the 30 days mortality was higher in the co-TBAD group. One-year survival was higher in the uncomplicated group but this difference was not observed in the 5-year survival.

CONCLUSION

In our analysis we can appreciate that despite significantly higher comorbidities in the co-TBAD cohort, there was no difference in in-hospital mortality between the two groups and the 5-year survival did not have any difference.

Mid-Term Results of Thoracic Endovascular Aortic Repair for Complicated Acute Type B Aortic Dissection at a Single Center

Background

Complicated acute type B aortic dissection is a life-threatening condition with high morbidity and mortality. The aim of this study was to report a single-center experience with endovascular stent-graft repair of acute type B dissection of the thoracic aorta and to evaluate the mid-term outcomes.

Methods

We reviewed 18 patients treated for complicated acute type B aortic dissection by thoracic endovascular aortic repair (TEVAR) from September 2011 to July 2017. The indications for surgery included rupture, impending rupture, limb ischemia, visceral malperfusion, and paraplegia. The median follow-up was 34.50 months (range, 12–80 months).

Results

The median interval from aortic dissection to TEVAR was 5.50 days (range, 0–32 days). There was no in-hospital mortality. All cases of malperfusion improved except for 1 patient. The morbidities included endoleak in 2 patients (11.1%), stroke in 3 patients (16.7%), pneumonia in 2 patients (11.1%), transient ischemia of the left arm in 1 patient (5.6%), and temporary visceral ischemia in 1 patient (5.6%). Postoperative computed tomography angiography at 1 year showed complete thrombosis of the false lumen in 15 patients (83.3%).

Conclusion

TEVAR of complicated type B aortic dissection with a stent-graft was effective, with a low morbidity and mortality rate.

[Treatment of a patient with acute thoracoabdominal aortic dissection complicated by haemothorax]

Total left-sided haemothorax is a rare and severe complication of acute DeBakey type III aortic dissection. The primary aim of treatment is immediate arrest of haemorrhage and stabilization of the haemodynamic status of the patient. Endovascular isolation of the ruptured thoracic portion of the aorta using a stent graft (TEVAR) has recently become the 'gold standard' in treatment of acute, rupture-complicated aortic dissections of this localization. Described in the article is a clinical case report concerning successful endovascular treatment of a seriously ill patient with dissection of the thoracoabdominal portion of the aorta, rupture and massive haemorrhage into the left pleural cavity. The patient underwent endoprosthetic repair of the descending aorta in the setting of a hybrid operating room under local anaesthesia, followed by drainage of the left pleural cavity. The postoperative period was uneventful with no complications. The patient was discharged in a satisfactory condition on day 10 after the emergency surgical intervention. An important advantage of TEVAR for aortic ruptures is a minimally invasive nature of the procedure, consisting in no need to perform either sternothoracotomy or to connect a heart-lung machine, thus decreasing surgical wound, reducing the risk of perioperative life-threatening haemorrhage, and contributing to early activation of the patient.

[Hybrid aortic repair in patients with type III aortic dissection and concomitant proximal aortic lesion]

OBJECTIVE

To report our own experience of hybrid treatment using FET technique in patients with type A aortic dissection and concomitant lesion of aortic arch and ascending aorta.

MATERIAL AND METHODS

There were 90 (28,3%) FET procedures for the period from January 2010 to August 2019. Type B aortic dissection was diagnosed in 19 (45,2%) patients. Type B aortic dissection combined with aortic arch aneurysm occurred in 11 (58%) cases, ascending aorta aneurysm - 15 (79%) cases. Patients underwent total arch and ascending aorta replacement via median sternotomy (upper partial J-shaped sternotomy in 3 cases). Valve-sparing interventions were performed in 58% of cases (aortic root repair - 6 (32%) patients, David procedure - 5 (26%) cases). Intraoperative features, early postoperative morbidity and in-hospital mortality were retrospectively analyzed. In long-term period, distal aortic remodeling, survival rate and incidence of redo interventions were evaluated.

RESULTS

Mean CPB time was 166±27 min, aortic cross-clamping time - 93±23 min, duration of circulatory arrest - 43±11 min. Neurological complications and paraplegia were absent. In-hospital mortality was absent. Reversible acute renal failure without need for hemodialysis developed in 2 cases (11%). Two patients underwent repeated intervention (TEVAR) due to dSINE and negative aortic remodeling. Annual survival rate was 100%. Freedom from redo aortic surgery was 89,5%.

CONCLUSION

FET surgery is an adequate alternative treatment for type B aortic dissection combined with lesion of aortic arch and ascending aorta. This approach ensures a one-stage repair in patients with contraindications to TEVAR. Unlike thoracotomy, FET procedure is valuable for simultaneous correction of cardiac and proximal aortic lesion, stabilizing the distal segments of dissected aorta. This is obvious advantage of this technique.

One-Year Single-Center Results of the Multilayer Flow Modulator Stents for the Treatment of Type B Aortic Dissection

Purpose

To report a single-center series of patients with type B aortic dissection treated with the Multilayer Flow Modulator (MFM).

Materials and Methods

Over a 36-month period, 23 patients (median age 53 years; 20 men) with complicated type B aortic dissections (2 acute, 5 subacute, and 16 chronic) were treated with the MFM. Primary endpoints of rupture or dissection-related death, overall mortality, and reintervention were evaluated using the Kaplan-Meier method; estimates for freedom from the endpoints are reported with the 95% confidence interval (CI). Secondary outcomes included technical success, adverse events, and aortic remodeling. Clinical and imaging data were collected preoperatively, directly postoperatively, and annually to 36 months for analysis using computational fluid dynamics (CFD).

Results

Initial technical success was 91.3%. The estimates of the endpoints at 12 months were 100% for freedom from rupture or aortic-related death, 95.7% for freedom from overall mortality, and 91.3% for freedom from reintervention. No device-related neurological or systemic complications occurred, and no additional reinterventions were needed during follow-up. A total of 144 branches overstented by the MFM remained patent. Morphologic analysis of the aortic dissection showed progressive true lumen volume increase (75.9%, p<0.001) with concomitant false lumen volume decrease (42.8%, p<0.001); the CFD analyses showed increased laminar flow.

Conclusion

In the current series, the MFM provided a safe and feasible treatment option for complicated acute, subacute, and chronic type B aortic dissections, with high technical success, low mortality, and active aortic remodeling. Further studies should elucidate the long-term safety of the MFM and its effectiveness in a larger patient cohort.

The surgical management of retrograde type A aortic dissection after thoracic endovascular aortic repair

OBJECTIVES

Our goal was to review the surgical treatment of retrograde type A aortic dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) in our centre.

METHODS

From January 2014 to April 2018, 22 patients with RTAD after TEVAR were operated on in our centre. The mean age at operation was 52.0 ± 8.0 years old. The median interval between the primary TEVAR procedure and RTAD was 4.6 months (range 0-120 months). The postoperative mortality and morbidity rates were calculated to evaluate the early and long-term results.

RESULTS

Twenty patients received total arch replacement with the frozen elephant trunk technique and 2 patients received total arch replacement alone. The mean cardiopulmonary bypass time, aortic cross-clamp time and selective cerebral perfusion time were 172.4 ± 39.3, 100.1 ± 30.3 and 19.7 ± 10.5 min, respectively. The incidence of major adverse events was 18.6% (4/22), including stroke in 1 patient, myocardial dysfunction in 1 patient and renal failure necessitating dialysis in 3 patients. Death within 30 days was 13.6% (3/22 patients). The follow-up data were available for all 19 survivors. The mean follow-up period was 32.2 ± 16.2 months (range 10-62 months). No deaths or aortic-related events occurred during the follow-up period.

CONCLUSIONS

Total arch replacement with or without the frozen elephant trunk technique was suitable for the management of RTAD after TEVAR, with acceptable early and long-term results.

Retrograde stenting of the superior mesenteric artery is the procedure of choice for dissection of the aorta with mesenteric compromise

Acute mesenteric ischemia secondary to aortic dissection in type A and type B is a true vascular surgical emergency. Presentation can be subtle or dramatic, and time to revascularization is limited before irreversible changes occur. The literature recognizes the catastrophic consequences of acute superior mesenteric artery occlusion and the need for urgent revascularization, often before central aortic repair in type A. There is no optimal revascularization technique described in this scenario. We present a case of type A aortic dissection with acute dynamic and static superior mesenteric artery occlusion and describe treatment that resulted in successful salvage of the bowel and the patient's life.

Combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair for complicated type B aortic dissections

BACKGROUND

Aortic dissection is a separation of the aortic wall, caused by blood flowing through a tear in the inner layer of the aorta. Aortic dissection is an infrequent but life-threatening condition. The incidence of aortic dissection is 3 to 6 per 10,000 per year in the Western population, and can be up to 43 per 10,000 per year in the Eastern population. Over 20% of people with an aortic dissection do not reach a hospital alive. After admission, the mortality rates for people with an aortic dissection are between 10% and 20% for those who received endovascular treatment, and between 20% and 30% for those who had open surgery. Thoracic endovascular aortic repair (TEVAR) is the standard endovascular method to treat complicated type B aortic dissection (aortic dissections without involvement of the ascending aorta). Although TEVAR is less invasive than open surgery and has a better long-term aortic remodeling effect than conservative medical treatment, favourable aortic remodelling is usually limited to the thoracic aortic segment. TEVAR cannot be extended into the abdominal aorta because it could cover the ostia of the reno-visceral arteries. Thus, the abdominal aorta is still at risk of progressive aneurysmal degeneration. The PETTICOAT (provisional extension to induce complete attachment) technique, with proximal endograft and distal bare metal stent, was proposed in 2006 to address this issue. The concept of this technique was to implant a distal bare metal stent into the aortic true lumen, distal to the proximal endograft, to stabilize the distal collapsed intimal flap, while allowing blood flow to reno-visceral arteries. Therefore, the PETTICOAT technique was considered to be related to a more extensive aortic remodelling for people with type B aortic dissection, especially in the area of the abdominal aorta. However, it is still unclear whether the PETTICOAT technique is superior to standard TEVAR.

OBJECTIVES

To assess the effects of combined proximal descending aortic endografting plus distal bare metal stenting versus conventional proximal descending aortic stent graft repair for treating complicated type B aortic dissections.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 5 November 2018. We also undertook reference checking and citation searching to identify additional studies.

SELECTION CRITERIA

We considered all randomised controlled trials which compared the outcome of complicated type B aortic dissection, when treated by combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed all references identified by the Cochrane Vascular Information Specialist. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We found no trials that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We identified no randomised controlled trials and therefore cannot draw any definite conclusion on this topic. Evidence from non-randomised studies appears to be favourable in the short-term, for combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) to solve the problem of unfavourable distal aortic remodeling. Randomised controlled trials are warranted to provide solid evidence on this topic. Evidence from cohort studies with large sample sizes would also be helpful in guiding clinical practice.

Proposed classification of endoleaks after endovascular treatment of Stanford type-B aortic dissections

Objectives

Despite two decades of experience, no dedicated classification system exists to document and prognosticate patterns of endoleak encountered after endovascular therapy of type-B aortic dissection. This nomenclature gap has led to inconsistent management and underreporting of significant findings associated with adverse outcomes after endovascular treatment of type-B aortic dissection. Our goal was to propose a reproducible and prognostically relevant classification.

Methods

A multidisciplinary team of seven experienced open and endovascular aortic surgeons was assembled to provide consensus opinion. Extensive literature review was conducted. Deficiencies in the current classification approach of the various patterns of persistent filling of false lumen after endovascular therapy were identified.

Results

Our focus was to categorize high-risk and low-risk subgroups within endoleaks after endovascular treatment of type-B aortic dissection. In this classification, type-Ia endoleak refers to persistent filling of the false lumen in an antegrade manner. Causes include failure to cover the primary entry tear and sizing or technical related proximal seal failure. False lumen filling via distal entry tears is classified as type Ib endoleak, which is further sub-classified into b1 (major branch-related tears), and b2 (multiple small branches related tears). Retrograde ascending aortic dissection and stent graft-induced new entry were classified as type-I endoleaks (type-Ir and type-Is, respectively). Another focus was reclassification type-II endoleaks, with type-IIa endoleak referring to conventional retroleak from one or more posterior branches and type-IIx referring to retroleak from major branches (visceral or left subclavian arteries).

Conclusions

The majority of endoleaks after endovascular treatment of type-B aortic dissection are related to persistent or new filling of the false lumen. We propose a new false lumen-based classification schema for endoleaks occurring after endovascular therapy of type-B aortic dissection.

Left ventricular remodeling in patients with acute type B aortic dissection after thoracic endovascular aortic repair: Short- and mid-term outcomes

BACKGROUND

Left ventricular (LV) remodeling remains unknown in patients with acute Type B aortic dissection (aTBAD) after thoracic endovascular aortic repair (TEVAR) during follow-up.

METHODS

Between May 2004 and January 2016, 163 consecutive patients (136 males, mean preoperative age: 51.06 ± 10.79 years) with aTBAD underwent TEVAR. A linear mixed model was used to evaluate risk factor influencing on LV remodeling and investigate longitudinal changes in LV thickness, diameter, volume, function and mass at preoperation, postoperation, short- and mid-term follow-up.

RESULTS

Median follow-up time was 48.0 months (quartiles 1-3, 31-84 months, maximum 147 months). LV thickness and mass followed a continuous downward trend over time. Interventricular septal thickness at end-diastole significantly decreased at mid-term follow-up (time, p < 0.001: preoperative 11.59 ± 0.14 mm vs mid-term 10.82 ± 0.15 mm, p < 0.001; postoperative 11.40 ± 0.14 mm vs mid-term 10.82 ± 0.15 mm, p = 0.006). LV posterior wall thickness at end-diastole was markedly reduced at mid-term follow-up (time, p < 0.001: preoperative 10.89 ± 0.11 mm vs mid-term 10.02 ± 0.11 mm, p < 0.001; postoperative 10.78 ± 0.13 mm vs mid-term 10.02 ± 0.11 mm, p < 0.001; short-term 10.56 ± 0.15 mm vs mid-term 10.02 ± 0.11 mm, p = 0.021). LV mass index markedly decreased during follow-up (time, p = 0.001: preoperative 129.60 ± 3.55 g/m² vs short-term 119.26 ± 3.19 g/m², p = 0.009; preoperative 129.60 ± 3.55 g/m² vs mid-term 115.79 ± 3.62 g/m², p = 0.003). LV function was improved, but not significantly so, during follow-up. Strict blood pressure control had no influence on LV remodeling. True lumen followed a continuous enlargement trend in terms of proximal thoracic aorta and celiac trunk level during follow-up.

CONCLUSIONS

TEVAR can reverse LV remodeling and LV hypertrophy in patients with aTBAD during follow-up.

Outcomes of Thoracic Endovascular Aortic Repair for Acute Type B Dissection in Patients With Intractable Pain or Refractory Hypertension

PURPOSE

To compare uncomplicated acute type B aortic dissection (UATBAD) patients with intractable pain/refractory hypertension treated with thoracic endovascular aortic repair (TEVAR) to UATBAD subjects without these features receiving best medical therapy (BMT).

METHODS

Interrogation of the hospital database identified 101 consecutive UATBAD patients admitted between January 2011 and December 2014. Of these, 74 patients (mean age 62±13 years; 44 men) were treated with BMT; the other 27 UATBAD patients (mean age 63±13 years; 17 men) were subsequently treated with TEVAR for intractable pain (24, 89%) and/or refractory hypertension (3, 11%) at a mean 2.4±3.3 days (median 1, range 0-12) after admission. Mixed models were employed to determine differences in centerline measured aortic remodeling. Propensity analysis was employed to mitigate selection bias. Kaplan-Meier methodology was used to estimate reintervention and survival.

RESULTS

The groups were well matched; there was no difference in demographics, comorbidities, or proportion with visceral involvement (70% for TEVAR vs 86% for BMT, p=0.08). There was no significant difference in length of stay (9.6±6.3 for TEVAR vs 10.3±7.8 for BMT, p=0.3), complications (19% for TEVAR vs 24% for BMT, p=0.6), or 30-day mortality (0 for TEVAR vs 7% for BMT, p=0.1). One (4%) TEVAR patient experienced retrograde dissection. BMT resulted in greater mean increase in discharge antihypertensive medications (1.7±1.9 vs 0.7±1.7 for TEVAR, p=0.03), but there was no difference in narcotic utilization. Mean follow-up was greater in the TEVAR group (17.9±16.0 months) compared with BMT patients (11.5±10.8 months, p=0.05). TEVAR significantly improved rates of aortic diameter change (1.5% vs 12.9% for BMT, p=0.007), complete false lumen thrombosis (41% vs 11% for BMT, p=0.004), and true lumen expansion (85% vs 7% for BMT, p<0.01). However, there was no difference in reintervention (25.9% for TEVAR vs 23% for BMT, p=0.2) or survival (log-rank p=0.8).

CONCLUSION

TEVAR for UATBAD with intractable pain/refractory hypertension is safe but offers no short-term outcome advantage when compared to UATBAD patients without these features receiving BMT. A significant improvement in aortic remodeling was identified after TEVAR. The potential long-term reintervention and aorta-related mortality benefits of this favorable remodeling have yet to be defined and randomized trials are warranted.

Promoting False-Lumen Thrombosis after Thoracic Endovascular Aneurysm Repair in Type B Aortic Dissection by Selectively Excluding False-Lumen Distal Entry Tears

PURPOSE

To evaluate the efficacy and clinical outcomes of ancillary endovascular procedures in promoting false-lumen (FL) thrombosis (FLT) and preventing aortic expansion in patients after thoracic endografting for type B dissections.

MATERIALS AND METHODS

This retrospective review included 15 patients (12 men and 3 women; mean age, 59.6 y). Mean aortic diameter at the time of ancillary treatment was 47.4 mm. Different techniques were used as single procedures or sequentially: covered stent occlusion of detached visceral artery entry tears, occlusion of single entry tears with vascular plugs, or aortic endograft occlusion of multiple FL entry tears. FL embolization with ethylene vinyl alcohol copolymer was performed when selective occlusion was considered insufficient to close distal entry tears. Apart from endovascular aneurysm repair, all procedures were performed percutaneously under local anesthesia. If FL diameter increase persisted after 6-month follow-up computed tomographic (CT) angiography, another intervention was planned; otherwise, yearly follow-up was performed.

RESULTS

Mean clinical follow-up duration was 43.8 months (range, 8 d to 86.8 mo), with no in-hospital mortality. Estimated overall survival rates were 93.3%, 86.6%, and 77% at 12, 24, and 48 months, respectively. Three late deaths occurred, one of which was dissection-related at 40 months. Eight surviving patients (53%) had total FLT and 3 had partial FLT with stable aortic diameter on follow-up CT angiography. FL diameter increased in one patient, requiring further intervention.

CONCLUSIONS

Selective exclusion of new distal entry tears remaining after thoracic endovascular aneurysm repair can stabilize abdominal aortic expansion and promote FLT.

Impact of age and urgency on survival after thoracic endovascular aortic repair

OBJECTIVE

Elderly patients are often turned down from receiving treatment for descending thoracic aortic diseases (DTADs) because of the uncertain benefits, especially in acute settings. This study investigated the impact of old age and timing of thoracic endovascular aortic repair (TEVAR) on outcomes of DTAD in patients older than 75 years of age.

METHODS

Patients from a prospective TEVAR database were dichotomized by age (75 and 80 years of age). Older and young patients were compared in three timing scenarios: (1) elective procedures, (2) any emergency (within 15 days from onset), and (3) acute ruptures (any emergency subgroup). Primary outcome was perioperative mortality assessed at 30 and 90 days.

RESULTS

Between 2003 and 2015, 141 consecutive TEVARs (71.6% men) were performed. Fifty-seven patients (40.4%) were older than 75 years of age; 28 were octogenarians. Eighty-three TEVARs were performed electively and 58 emergently. Among overall emergencies, 42 TEVARs were for acute ruptures. In the elective scenario, the 30-day mortality rate was 5.0% vs 0 (odds ratio [OR], 1.1; 95% confidence interval [CI], 0.98-1.1; P = .23), and 90-day mortality was 7.5% vs 0, for patients older than 75 years of age vs those who were younger than 75, respectively (P = .11). No octogenarian died. In the emergency scenario, 30-day mortality was 41.2% vs 9.8%, for patients older than 75 years of age vs those who were younger than 75, respectively (OR, 6.5; 95% CI, 1.6-26.6; P = .01) with unchanged rates at 90 days. The mortality rate was 50% for octogenarians. In the acute rupture scenario, 30-day mortality was 40% vs 11.1% (OR, 5.3; 95% CI, 1.10-25.99; P = .05) for patients older than 75 years of age vs those younger than 75 years of age and 46% vs 10% (OR, 7.5; 95% CI, 1.47-37.46; P = .016) for octogenarians vs younger patients. Rates remained unchanged at 90 days. Patients older than age 75 survived for a mean of 53.98 ± 7.7 months after TEVAR.

CONCLUSIONS

In the elderly patient population with DTAD, mortality risks from TEVAR are strongly related to timing and age. When compared to younger patients, those older than 75 years of age have three to five times the risk of mortality after urgent or emergent TEVAR. However, older patients should still be considered for emergent life-saving treatment, given that the majority survives.

Type A aortic dissection model to improve endovascular research and technologies

OBJECTIVE

Type A aortic dissection is a life-threatening disease requiring immediate surgical treatment. With emerging catheter-based technologies, endovascular stent-graft implantation to treat aneurysms and dissections has become a standardized procedure. However, endovascular treatment of the ascending aorta remains challenging. Thus we designed an ascending aortic dissection model to allow simulation of endovascular treatment.

METHODS

Five formalin-fixed human aortas were prepared. The ascending aorta was opened semicircularly in the middle portion and the medial layer was separated from the intima. The intimal tube was readapted using running monofilament sutures. The preparations were assessed by 128-slice computed tomography. A bare-metal stent was implanted for thoracic endovascular aortic repair in 4 of the aortic dissection models.

RESULTS

Separation of the intimal and medial layer of the aorta was considered to be sufficient because computed tomography showed a clear image of the dissection membrane in each aorta. The dissection was located 3.9 ± 1.4 cm proximally from the aortic annulus, with a length of 4.6 ± 0.9 cm. Before stent implantation, the mean distance from the intimal flap to the aortic wall was measured as 0.63 ± 0.163 cm in the ascending aorta. After stent implantation, this distance decreased to 0.26 ± 0.12 cm.

CONCLUSION

This model of aortic dissection of the ascending human aorta was reproducible with a comparable pathological and morphological appearance. The technique and model can be used to evaluate new stent-graft technologies to treat type A dissection and facilitate training for surgeons.

Management of aortic dissection: medical therapy and intervention. Is there a growing role for endovascular techniques?

OPINION STATEMENT

Historically, type B aortic dissection was managed as a medical condition with limited surgical intervention unless aortic rupture occurred. Today, however, evidence is building that highlights the importance of strict medical management, timely surveillance, and windows of opportunity for surgical intervention to address both early and late aortic-based morbidities.

Delayed visceral and spinal cord malperfusion after axillo-bifemoral bypass for complicated acute type B aortic dissection

We describe a successfully treated case of acute type B aortic dissection complicated with lower extremity, visceral, and spinal cord malperfusion. To restore perfusion to both lower extremities, we performed an emergency right axillo-bifemoral bypass. Furthermore, we performed total arch replacement, including primary entry closure, because of delayed visceral organ ischemia. Unexpectedly, delayed paraplegia occurred after hospital discharge; however, the patient recovered without any neurologic sequelae after early introduction of hyperbaric oxygen therapy. Because another episode of organ malperfusion in the long term cannot be anticipated, and even though the previous organ malperfusion episode was treated successfully, close observation is mandatory for detecting clinical manifestations in combination with the availability of imaging modalities.

Emergency endovascular stent grafting in acute complicated type B dissection

OBJECTIVE

The objective of this study was to assess midterm results of emergency endovascular stent grafting for patients with life-threatening complications of acute type B aortic dissection.

METHODS

Between March 1999 and November 2011, 110 patients (86 men, 24 women) with complications of acute type B aortic dissection (mean age, 61 years; range, 19-87 years) were treated with thoracic endovascular aortic repair for malperfusion (55.5%) or aortic rupture (53.6%) in five major European referral centers and one U.S. referral center. Additional comorbidities included hypertension in 90 patients (82%), diabetes in 14 patients (13%), and chronic obstructive pulmonary disease in six patients (6%). Eleven patients (10%) had undergone previous aortic surgery.

RESULTS

Overall hospital mortality was 12% (n = 13), with 14 late deaths after hospital discharge. In-hospital complications occurred in 32 patients (36%); 10 patients developed postoperative renal failure, five patients experienced new permanent neurologic symptoms, and six patients (5.4%) experienced retrograde type A aortic dissection. Furthermore, nine patients (8%) developed an early type I endoleak. Actuarial survival at 1 and 5 years was 85% and 73%, respectively. Postprocedural computed tomography angiography showed complete or partial thrombosis of the false lumen at the stent graft level in 61% and 23% of all patients, respectively. Freedom from treatment failure according to the Stanford classification was 82%, 75%, and 59% at 1, 3, and 5 years.

CONCLUSIONS

Endovascular repair of complicated acute type B aortic dissection is proven to be a technically feasible and effective treatment modality in this relatively difficult patient cohort. Short-term and midterm results are persuasive; however, the long-term efficacy needs to be further evaluated.

Systematic review of outcomes of combined proximal stent-grafting with distal bare stenting for management of aortic dissection

OBJECTIVE

Available data on outcomes of combined proximal stent-grafting with distal bare stenting for management of aortic dissection are limited. The objective of this study was to provide a systematic review of outcomes of this approach.

METHODS

Studies involving combined proximal stent-grafting with distal bare stenting for management of aortic dissection were systematically searched and reviewed through MEDLINE databases.

RESULTS

A TOTAL OF FOUR STUDIES WERE INCLUDED: 108 patients treated for management of acute (n=54) and chronic (n=54) aortic dissection. The technical success rate was 95.3% (range, 84-100%). The 30-day mortality rate was 2.7% (range from 0% to 5%). The morbidity rate occurring within 30 days was 51.8% (range from 0% to 65%) and included stroke (2.7%), paraplegia (2.7%), retrograde dissection (1.8%), renal failure (14.8%), severe cardiopulmonary complications (5.5%) and bowel ischemia (0.9%). The incidence of type I endoleak was 9.2% (10/108). During follow-up, 5 (4.6%) deaths were related to aortic rupture or aortic repair. Mean re-intervention rate was 12.9%. Two cases (1.9%) of delayed retrograde type A dissection and one case of aortobronchial fistula (0.9%) were reported. The most common delayed complication was thoracic stent-graft migration (4.7%). The rate of device failure was 9.2%. Favorable aortic remodeling was observed: studies reporting midterm follow-up of the true lumen demonstrated a high rate of both false lumen regression and true lumen expansion. At 12 months, complete false lumen thrombosis was observed at the thoracic level in 70.4% and at the abdominal level in 13.5% of patients.

CONCLUSIONS

Combined proximal stent-grafting with distal bare stenting appears to be a feasible approach for the management of Type B aortic dissection. Although this approach clearly improved true lumen perfusion and diameter, it failed to completely suppress false lumen patency. However, it should be acknowledged that contemporary data on this approach is limited to small studies with variable results.

Endovascular management of chronic post-dissection aneurysms

Open repair is still the gold standard in acute type A dissection. Endovascular repair is advocated for complicated acute type B dissections. Recent evidence also supports the role of endovascular repair in a larger proportion of uncomplicated acute type B dissections. The role of endovascular repair in chronic post-dissection aneurysms, however, is still unclear. Most commonly, post-dissection aneurysms involve the thoracoabdominal aorta, making the use of fenestrated/branched stent-grafts to achieve complete aneurysm exclusion mandatory. These fenestrated/branched stent-grafts have been used with success in atherosclerotic thoracoabdominal aortic aneurysms (TAAAs). In chronic post-dissection aneurysms, however, additional technical challenges arise. The usually narrow true lumen makes the use of branches more tedious and overall planning difficult. A second technical challenge relates to the fact that visceral branches can also originate from the false lumen. In such cases, perforation of the stiff chronic dissection flap is required to obtain access to the vessel. During the period January 2010 to November 2013, 17 patients (13 males, mean age 65±7.8 years) with chronic thoracoabdominal aneurismal degeneration following acute dissection were treated in our department with the use of fenestrated/branched stent-grafts. Technical success was achieved in all cases (100%). Perioperative mortality was two (11.8%) patients. One patient died due to multiple organ failure and one due to cardiac failure. No case of paraplegia was observed. During a 12-month median follow-up (range, 4-28 months) no aneurysm-related deaths were observed. Reintervention was required in three cases to repair a type Ib endoleak from a side branch. Endovascular treatment with fenestrated/branched stent-grafts is feasible for chronic post-dissection aneurysms. Standard thoracic stent-grafting is an option in a minority of patients, when the aneurysm is limited to the thoracic segment. Fenestrated and branched devices can successfully be used for aneurysms extending to the thoracoabdominal aorta.

Evaluation of the hemodynamic effectiveness of aortic dissection treatments via virtual stenting

Aortic dissection treatment varies for each patient and stenting is one of a number of approaches that are utilized to Stabilize the condition. Information regarding the hemodynamic forces in the aorta in dissected and virtually stented cases could support clinicians in their choices of treatment prior to medical intervention. Computational fluid dynamics coupled with lumped parameter models have shown promise in providing detailed information that could be used in the clinic; for this, it is necessary to develop personalized workflows in order to produce patient-specific simulations. In the present study, a case of pre- and post-stenting (virtual stent-graft) of an aortic dissection is investigated with a particular focus on the role of personalized boundary conditions. For each virtual case, velocity, pressure, energy loss, and wall shear stress values are evaluated and compared. The simulated single stent-graft only marginally reduced the pulse pressure and systemic energy loss. The double stent-graft results showed a larger reduction in pulse pressure and a 40% reduction in energy loss as well as a more physiological wall shear stress distribution.Regions of potential risk were highlighted. The methodology applied in the present study revealed detailed information about two possible surgical outcome cases and shows promise as both a diagnostic and an interventional tool.

Prognostic factors in patients with uncomplicated acute type B aortic dissection

BACKGROUND

The benefit of thoracic endovascular aortic repair (TEVAR) for uncomplicated acute type B aortic dissection is unclear. Reliable prognostic factors are needed to identify candidates for prophylactic TEVAR. The aim of this study was to detect prognostic factors in patients with uncomplicated acute type B aortic dissection.

METHODS

From January 2003 to April 2012, a total of 228 patients with uncomplicated acute type B aortic dissection were admitted to our institute. Cox proportional hazards analysis was performed to identify risk factors for death, dissection-related death, and aortic events.

RESULTS

Independent predictors of mortality were age (hazard ratio [HR], 1.08; p < 0.001) and false lumen thickness (mm) (HR, 1.10; p = 0.013), and the risk factor for dissection-related death was false lumen thickness (mm) (HR, 1.14; p < 0.001). Independent risk factors for aortic events were diameter of the descending aorta (mm) (HR, 1.14; p < 0.001) and entry in a proximal site (HR, 2.90; p = 0.02). The actuarial freedom from aortic events in patients with a descending aortic diameter of less than 40 mm and no entry in a proximal site at 1, 3, and 5 years was 96.6%, 90.8%, and 82.5%, respectively, whereas in patients with 1 of these 2 factors, it was 80.1%, 66.8%, and 53.5%, respectively.

CONCLUSIONS

In uncomplicated acute type B aortic dissection, the diameter of the descending aorta and entry in a proximal site were independent prognostic factors for aortic events. Prophylactic TEVAR should be considered for patients with these risk factors.

Debate: Whether level I evidence comparing thoracic endovascular repair and medical management is necessary for uncomplicated type B aortic dissections

Type B aortic dissections continue to be one of the most challenging clinical scenarios confronting vascular surgeons. In the era of open surgery, the therapeutic options were limited to medical management of hypertension and large open thoracoabdominal operations. In the current endovascular era, the operative strategies have become less invasive but the questions regarding therapeutic approaches have become more numerous and complex. In patients with acute uncomplicated type B aortic dissections, we are still unsure as to which patients are best treated with medical therapy alone or with the addition of early endovascular repair. Data from single centers and registries have provided some guidance; however, questions remain. Perhaps level 1 evidence from well-designed randomized controlled trials will answer all of our questions. This is the topic of the current debate.

Treatment of acute type-B aortic dissection: thoracic endovascular aortic repair or medical management alone?

OBJECTIVES

This study sought to evaluate the early and long-term effect of thoracic endovascular aortic repair (TEVAR) on type-B acute aortic dissection (AAD).

BACKGROUND

Uncomplicated type-B AAD is generally treated with medical management; complicated dissections require surgery or TEVAR. Studies have demonstrated that long-term outcomes with medical management are suboptimal. Therefore, we sought to determine the long-term effect of TEVAR compared with medical management alone on type-B AAD.

METHODS

From January 2004 to May 2008, 193 consecutive patients in 2 hospitals were treated and retrospectively placed into 1 of 2 groups: 1) the TEVAR group-type-B AAD treated with TEVAR and antihypertensive medications (n = 152); and the 2) medicine group-uncomplicated type-B AAD treated medically alone (n = 41). All TEVAR procedures were performed in the acute phase.

RESULTS

There were no significant differences in demographics, comorbidity profiles, or early events between groups. The cumulative freedom from all late adverse events at 1, 3, and 5 years was 97%, 89%, and 67% in the TEVAR group and 97%, 63%, and 34% in the medicine group. Log-rank tests showed that medically treated patients had more late adverse events than TEVAR-treated patients did (p = 0.003). The 5-year cumulative survival rate from all-cause death was not significantly different between the 2 groups.

CONCLUSIONS

Patients with type-B AAD treated with TEVAR experienced fewer late adverse events than those treated with medical management, but there was no significant difference among the groups in 5-year mortality rates. Further studies of longer-term survival rates are needed to determine whether TEVAR could be an effective treatment for type-B AAD.

Endovascular Versus Medical Therapy for Uncomplicated Type B Aortic Dissection

Background:

Uncomplicated type B dissections have been traditionally managed with antihypertensive therapy. In the endovascular era, this dictum has been revisited. This review pooled the available studies to compare the outcomes of best medical therapy (BMT) to thoracic endovascular aortic repair (TEVAR) for uncomplicated type B dissections.

Methods:

A literature search was performed to identify studies on uncomplicated type B dissections managed with BMT with and without TEVAR. The primary outcome measures were mortality rates at 30 days and at 2 years following intervention.

Results:

A total of 6 studies included 123 patients who underwent TEVAR/BMT, and 566 patients who had BMT alone. The mortality rates at 30 days (6.5% TEVAR/BMT vs 4.8% BMT, P = .21) and at 2 years (9.7% vs 11.9%, P = .32) were similar. Renal failure was greater in TEVAR/BMT (15.4% vs 2.1%, P < .01). Rates of surgical reintervention/intervention were similar (17.6% vs 20.1%, P = .31).

Conclusion:

The TEVAR with BMT does not provide survival benefit compared to BMT alone, 2 years following uncomplicated type B aortic dissection.

[Stent graft of the thoracic aorta]

Considering the demographic changes in our society and the proliferation of imaging-based improved diagnostics, both acute and chronic aortic diseases attract increasing attention and require dedicated care. Cardiac as well as vascular surgery used to represent the gold standards for therapeutic management of pathologies of the ascending aorta and the arch; however, the technological evolution of endoluminal strategies has had a serious impact on the treatment of the descending aorta, the aortic arch in combination with vascular debranching or bypass, and in selected cases even on managing pathologies of the ascending aorta. Although several case series and meta-analyses of published observations hint towards superiority of endografting in comparison to open surgical repair, the affected usually multimorbid patients with highly complex aortic disease should be subjected to an individual evaluation by a team of cardiologists, cardiac and vascular surgeons as well as imaging specialists; a dedicated individualized treatment concept in highly experienced centers of excellence is likely to provide the best results for such challenging patients.

Early malperfusion, ischemia reperfusion injury, and respiratory failure in acute complicated type B aortic dissection after thoracic endovascular repair

BACKGROUND

The aim of this study was to determine the early mortality and major complications of acute complicated type B aortic dissection (ACBD) after thoracic endovascular aortic repair (TEVAR).

METHODS

Twenty-six consecutive patients with ACBD who underwent TEVAR were included. Clinical indications before TEVAR and in-hospital mortality and major complications after TEVAR were analyzed and compared with similar reports.

RESULTS

TEVAR was technically successful in all cases. In-hospital mortality occurred in four patients (15%), and major complications occurred in an additional four patients (15%). Three of the four (75%) of the deaths were associated with malperfusion and ischemia reperfusion injury (IRI), and 3/4 (75%) of the major complications were caused by respiratory failure (RF).

CONCLUSIONS

In-hospital mortality associated strongly with severe end-organ malperfusion and IRI, while major complications associated with RF, during TEVAR. Our results indicate that malperfusion, IRI and respiratory failure during TEVAR should be carefully monitored and aggressively treated.