Endovascular Treatment of Acute Complicated Aortic Dissection: Long-term Follow-up of Clinical Outcomes and CT Findings

Endovascular interventions in main renal artery pathologies: an overview and update

Renal arteries are involved in a wide spectrum of pathologies including atherosclerosis, fibromuscular dysplasia, Takayasu arteritis, aneurysms, and aortic type B dissections extending into main renal arteries. They manifest as renovascular hypertension, renal ischemia, and cardiovascular dysfunction. The location of the renal arteries in relation to the abdominal aortic aneurysm is a critical determinant of interventional options and long-term prognosis. This article provides a comprehensive review of the role of interventional radiologists in transcatheter interventions in various pathologies involving the main renal arteries with analysis of epidemiology, pathophysiology, newer interventional techniques, and management options.

Outcomes and Predictors of Endovascular Treatment for Type B Aortic Dissection Complicated by Unilateral Renal Ischemia

PURPOSE

This study investigated the outcomes of endovascular treatment for type B aortic dissection (TBAD) complicated by unilateral renal ischemia and determined the associated predictors.

MATERIALS AND METHODS

From January 2010 to December 2016, 44 patients (mean : 54 years of age) with TBAD complicated by a clearly involved unilateral renal artery and a decreased mean density of the unilateral renal parenchyma were enrolled. The volumes and mean densities of each kidney were generated with postprocessing software based on computed tomography angiography. The degree of renal malperfusion (RMD) was defined as the bilateral density difference-to-the mean density ratio of the healthy kidney. The primary outcomes were renal atrophy and renal dysfunction; the secondary outcomes were aorta-related complications.

RESULTS

The median follow-up time was 51 months (range: 12-102 months). During follow-up, unilateral renal atrophy and renal dysfunction were observed in 12 patients (27.3%) and 7 patients (15.9%), respectively. RMD showed a moderate predictive value for renal atrophy, with an area under the characteristic curve (AUC) of 0.78. The optimal cutoff value was 27% for RMD in terms of predicting renal atrophy (sensitivity: 91.7%; specificity: 56.2%). Moreover, aorta-related adverse events occurred in 14 patients (31.8%). Preoperative abnormal creatinine level was an independent risk factor for aorta-related complications (odds ratio [OR]: 17.5; P = 0.022) and renal dysfunction (OR: 14.2; P = 0.02).

CONCLUSIONS

Preoperative serum creatinine was an effective index used to predict renal and aortic outcomes in this patient cohort. Active imaging follow-up and aggressive endovascular intervention are suggested in patients with RMD >27%.

Renal artery involvement in acute aortic dissection: Prevalence and impact on renal atrophy in non-interventional treatment patients

BACKGROUND

To evaluate the frequency of renal artery dissection (RAD) and renal hypoperfusion in aortic dissection (AD) and its effect on subsequent renal atrophy in patients who did not undergo therapeutic intervention.

METHODS

Initial CT data of 155 patients with acute AD (Stanford type A = 88, B = 67) were retrospectively analyzed. The false lumen statuses were patent (n = 94), partially thrombosed (n = 25), and completely thrombosed (n = 36) (also called as intramural hematoma (IMH)). Follow-up CT images of the surviving 122 patients (6-62.6 months, median, 28.9 months) were reviewed for analysis of sequential changes in renal volume. A regional decrease of ≧20 Hounsfield units in the renal cortex was defined as a renal hypo-enhancement sign (RHS). Simplified CT estimations of renal volume and estimated glomerular filtration rates (eGFR) were calculated. The generalized estimating equations (GEE) method was used to predict renal atrophy.

RESULTS

Fifty of the 122 patients presented with 59 RAD in the current study, and a positive RHS was noted in 33.9% (20/59) of these involved kidneys. GEE analysis showed hypertension, surgical treatment for AD, presence of RAD, and positive RHS as significant risk factors for renal atrophy. Patients with RHS had the most severe form of renal atrophy. The severity of renal atrophy was mildly correlated with GFR change (γ2 = 0.044, p < 0.001).

CONCLUSION

Renal atrophy in AD was predicted by the CT findings of RAD and RHS. The severity of renal atrophy was weakly reflected by eGFR.

Frequency of abdominal aortic expansion after thoracic endovascular repair of type B aortic dissection

Purpose

To determine abdominal aortic expansion after thoracic endovascular aortic repair (TEVAR) in patients with aortic dissection type B and 36 months minimum follow-up.

Methods

Retrospective study of 18 TEVAR patients with follow-up >36 months. Abdominal aortic diameters at celiac trunk (location B) and infrarenal aorta (location C) were recorded on the first and last imaging after TEVAR. False lumen thrombosis was determined at level of endograft (A) and at B and C. Aortic expansion was defined as diameter increase of 5 mm or 15%. Correlation analyses were performed to investigate potential determinants of expansion.

Results

Median follow-up was 75.2 months. Sixteen of 18 patients (88.9%) demonstrated abdominal expansion. Mean expansion was 9.9 ± 6.1 mm at B and 11.7 ± 6.5 mm at C, without a difference between acute and chronic dissections. Critical diameters of 55 mm were reached in two patients treated for chronic dissection (11.1%). Annual diameter increase was significantly greater at locations with baseline diameters >30 mm (2.1 ± 1.1 mm vs. 1.0 ± 0.6 mm, p = 0.009). Baseline diameters were greater in patients with chronic dissections.

Conclusion

Abdominal aortic expansion can be frequently recognized after TEVAR for aortic dissection type B and occurs independently from thoracic false lumen thrombosis. Clinical significant abdominal aortic expansion may occur more frequently in patients treated with TEVAR for chronic dissection.

Endovascular repair of acute uncomplicated aortic type B dissection promotes aortic remodelling: 1 year results of the ADSORB trial

OBJECTIVES

Uncomplicated acute type B aortic dissection (AD) treated conservatively has a 10% 30-day mortality and up to 25% need intervention within 4 years. In complicated AD, stent grafts have been encouraging. The aim of the present prospective randomised trial was to compare best medical treatment (BMT) with BMT and Gore TAG stent graft in patients with uncomplicated AD. The primary endpoint was a combination of incomplete/no false lumen thrombosis, aortic dilatation, or aortic rupture at 1 year.

METHODS

The AD history had to be less than 14 days, and exclusion criteria were rupture, impending rupture, malperfusion. Of the 61 patients randomised, 80% were DeBakey type IIIB.

RESULTS

Thirty-one patients were randomised to the BMT group and 30 to the BMT+TAG group. Mean age was 63 years for both groups. The left subclavian artery was completely covered in 47% and in part in 17% of the cases. During the first 30 days, no deaths occurred in either group, but there were three crossovers from the BMT to the BMT+TAG group, all due to progression of disease within 1 week. There were two withdrawals from the BMT+TAG group. At the 1-year follow up there had been another two failures in the BMT group: one malperfusion and one aneurysm formation (p = .056 for all). One death occurred in the BMT+TAG group. For the overall endpoint BMT+TAG was significantly different from BMT only (p < .001). Incomplete false lumen thrombosis, was found in 13 (43%) of the TAG+BMT group and 30 (97%) of the BMT group (p < .001). The false lumen reduced in size in the BMT+TAG group (p < .001) whereas in the BMT group it increased. The true lumen increased in the BMT+TAG (p < .001) whereas in the BMT group it remained unchanged. The overall transverse diameter was the same at the beginning and after 1 year in the BMT group (42.1 mm), but in the BMT+TAG it decreased (38.8 mm; p = .062).

CONCLUSIONS

Uncomplicated AD can be safely treated with the Gore TAG device. Remodelling with thrombosis of the false lumen and reduction of its diameter is induced by the stent graft, but long term results are needed.

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.

Role of the femorofemoral crossover graft in acute lower limb ischemia due to acute type B aortic dissection

Acute limb ischemia due to type B aortic dissection is rare and continues to be a management challenge. A case series is presented here with the aim of assessing the outcomes of treatment with a femorofemoral crossover graft with or without thoracic stent graft insertion. This is a combined retrospective and prospective review of nine cases of acute lower limb ischemia secondary to acute type B aortic dissection. The presenting features, radiological findings, treatment and outcomes were reviewed. Five patients had a femorofemoral crossover graft (FFXO) alone, two an FFXO with a thoracic stent graft and the eighth a thoracic and iliac stent. The other case was initially treated conservatively but subsequently required an FFXO. The mean follow-up was 16 (3-51) months. A further two thoracic stents were placed during the follow-up period. Thus five out of nine patients (56%) required aortic stenting. This series suggests that an FFXO is a reliable treatment for acute limb ischemia due to type B aortic dissection. However, these patients are often complex with ischemia in other vascular beds and are at risk of subsequent aneurysmal dilation.

Endovascular approaches and perioperative considerations in acute aortic dissection

Aortic dissections remain complicated management issues both in the acute setting and in the chronic setting. Acute problems revolve around malperfusion syndromes or rupture, whereas chronic issues progress from the development of aneurysms in the residual dissected aorta. Endovascular approaches to dealing with these difficult situations are being used more frequently to treat acute issues in type B dissections and prevent secondary complications in type A dissections that may require significant intervention in the future. This article discusses the endovascular approaches employed in the care of acute dissections with particular attention toward the anesthetic considerations involved in these challenging cases.

[Acute visceral ischaemia, early complication of the aortic syndrome: how to detect and manage it?]

Visceral malperfusion as a complication of aortic dissection represent 20 % of all type A or B aortic dissections. Visceral ischaemia is a factor of poor prognosis resulting in a higher mortality for these patients, yet, its clinical diagnosis is often underestimated. In all cases, the cross-sectional imaging, especially computed tomography, is needed to precise the mechanism of ischaemia. It allows differentiating dynamic from static ischaemia and thus to adapt its management. Endovascular treatment of ischaemia has been developed because it allows to a rapid treatment with a high success and low complication rates. Early results of aortic stentgrafting and aortic fenestration are up to 96 %, but late changes on the morphology or function reperfused gut was not studied.

Acute complicated and uncomplicated type III aortic dissection: an endovascular perspective

Type III aortic dissection is associated with high morbidity and mortality. There is a shifting paradigm in the treatment of complicated and uncomplicated acute type III aortic dissection toward earlier endovascular repair. In this review, the authors present the current perspective on the endovascular management of acute complicated and uncomplicated type III aortic dissection.