Background Patients with uncomplicated acute type B aortic dissection (ABAD) generally can be treated with conservative medical management. However, these patients may develop aortic enlargement ...during follow-up, with the risk for rupture, which necessitates intervention. Several predictors have been studied in recent years to identify ABAD patients at high risk for aortic enlargement who may benefit from early surgical or endovascular intervention. This study systematically reviewed and summarized the current available literature on prognostic variables related to aortic enlargement during follow-up in uncomplicated ABAD patients. Methods Studies were included if they reported predictors of aortic growth in uncomplicated ABAD patients. Studies about type A aortic dissection, aortic aneurysm, intramural hematoma, or ABAD that required acute intervention were excluded. Results A total of 18 full-text articles were selected. The following predictors of aortic growth in ABAD patients were identified: age <60 years, white race, Marfan syndrome, high fibrinogen-fibrin degradation product level (≥20 μg/mL) at admission, aortic diameter ≥40 mm on initial imaging, proximal descending thoracic aorta false lumen (FL) diameter ≥22 mm, elliptic formation of the true lumen, patent FL, partially thrombosed FL, saccular formation of the FL, presence of one entry tear, large entry tear (≥10 mm) located in the proximal part of the dissection, FL located at the inner aortic curvature, fusiform dilated proximal descending aorta, and areas with ulcer-like projections. Tight heart rate control (<60 beats/min), use of calcium-channel blockers, thrombosed FL, two or more entry tears, FL located at the outer aortic curvature, and circular configuration of the true lumen were associated with negative or limited aortic growth. Conclusions Several predictors might be used to identify those ABAD patients at high risk for aortic growth. Although conservative management remains indicated in uncomplicated ABAD, these patients might benefit from closer follow-up or early endovascular intervention.
Background Partial thrombosis of the false lumen has been reported as a significant predictor of mortality during follow-up in patients with acute type B aortic dissection. The purpose of this study ...was to investigate the correlation of false lumen thrombosis and aortic expansion during follow-up in patients with acute type B aortic dissection. Methods All medically treated patients with acute type B aortic dissection observed in 4 cardiovascular referral centers between 1998 and 2011, with admission and follow-up computed tomography or magnetic resonance imaging scans, were included. Aortic diameters of the dissected aortas were measured at 4 levels on the baseline and follow-up scans, and annual growth rates were calculated. Univariate and multivariate regression analyses were used to investigate the effect of false lumen thrombosis on aortic growth rate. Results A total of 84 patients were included, of whom 40 (47.6%) had a partially thrombosed false lumen, 7 (8.3%) had a completely thrombosed false lumen, and 37 (44.0%) had a patent false lumen. A total of 273 of the 336 (81.3%) evaluated aortic levels were dissected segments. Overall, the mean aortic diameter increased significantly at all evaluated levels ( P < .001). Univariate analysis showed that annual aortic growth rates were significantly higher in those segments having a false lumen with partial thrombosis (mean, 4.25 ± 10.2) when compared with the patent group (mean, 2.10 ± 5.56; P = .035). In multivariate analysis, partial lumen thrombosis was an independent predictor of higher aortic growth (adjusted mean difference, 2.05 mm/year; 95% confidence interval, 0.10-4.01; P = .040). Conclusions In patients with acute type B aortic dissection, aortic segments with a partially thrombosed false lumen have a significantly higher annual aortic growth rate when compared with those presenting with patent or complete thrombosis of the false lumen. Therefore, patients with partial thrombosis require more intensive follow-up and may benefit from prophylactic intervention.
Background Conservative management of acute type B aortic dissection (ABAD) is often associated with aortic dilatation during follow-up increasing the risk of aortic rupture. The goal of this study ...was to investigate whether morphologic characteristics of the dissection can predict aortic growth. Methods All conservatively managed ABAD patients from four referral centers were included (2000 to 2010). Aortic diameters were measured at five levels at baseline and at the last follow-up computed tomography angiography, and annual aortic growth rates were calculated for all segments. Linear regression was used to study the influence of aortic morphologic characteristics for aortic dilatation. Results Included were 62 patients (41 men) with a mean age of 60.3 ± 10.7 years. Among the 310 analyzed aortic segments, 248 (80.0%) were dissected, of which 211 (85.1%) showed aortic growth. Overall, the mean diameter increased from 36.1 ± 9.4 to 40.2 ± 11.1 mm ( P < .01), which corresponds with a mean aortic growth rate of 3.1 ± 6.3 mm/y. Multivariate linear regression analysis showed that male sex (95% confidence interval CI, 0.60-4.04; P = .005) and a saccular false lumen (95% CI, 2.07-7.81: P = .001) were associated with a significantly increased aortic growth rate. Increasing age (95% CI, −0.23 to −0.04; P = .005), increased number of entry tears (95% CI, −2.40 to −0.43; P = .005), false lumen located on the aortic outer curvature (95% CI, −4.30 to −0.38; P = .019), and a circular configuration of the true lumen (95% CI, −5.35 to −0.32; P = .027) were associated with a decreased aortic growth rate. Conclusions Multiple morphologic characteristics appear to predict aortic dilatation in ABAD patients treated medically. Early assessment of these morphologic signs may be useful in the selection of ABAD patients who might benefit from closer radiologic surveillance or prophylactic intervention.
Thoracic endovascular aortic repair (TEVAR) has been shown to lead to increased aortic stiffness. The aim of this study was to investigate the effect of stent graft type and stent graft length on ...aortic stiffness in a controlled, experimental setting.
Twenty porcine thoracic aortas were connected to a pulsatile mock loop system. Intraluminal pressure was recorded at two sites in order to measure pulse wave velocity (PWV) for each aorta: before stent graft deployment (t1); after deployment of a 100-mm long stent graft (t2); and after distal extension through deployment of a second 100-mm long stent graft (t3). Four different types of stent grafts (Conformable Gore® TAG® Device, Bolton Relay® Device, Cook Zenith Alpha™, and Medtronic Valiant®) were evaluated.
For the total cohort of 20 aortas, PWV increased by a mean 0.6 m/s or 8.9% of baseline PWV after deployment of a 100-mm proximal stent graft (P<0.001), and by a mean 1.4 m/s or 23.0% of baseline PWV after distal extension of the stent graft (P<0.001). Univariable regression analysis showed a significant correlation between aortic PWV and extent of stent graft coverage, (P<0.001), but no significant effect of baseline aortic length, baseline aortic PWV, or stent graft type on the percentual increase in PWV at t2 or at t3.
In this experimental set-up, aortic stiffness increased significantly after stent graft deployment with each of the four types of stent graft, with the increase in aortic stiffness depending on the extent of stent graft coverage.
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.
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.
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.
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.
Objective Isolated renal artery aneurysms are rare, and controversy remains about indications for surgical repair. Little is known about the impact of endovascular therapy on selection of patients ...and outcomes of renal artery aneurysms. Methods We identified all patients undergoing open or endovascular repair of isolated renal artery aneurysms in the Nationwide Inpatient Sample from 1988 to 2011 for epidemiologic analysis. Elective cases were selected from the period 2000 to 2011 to create comparable cohorts for outcome comparison. We identified all patients with a primary diagnosis of renal artery aneurysms undergoing open surgery (reconstruction or nephrectomy) or endovascular repair (coil or stent). Patients with concomitant aortic aneurysms or dissections were excluded. We evaluated patient characteristics, management, and in-hospital outcomes for open and endovascular repair, and we examined changes in management and outcomes over time. Results We identified 6234 renal artery aneurysm repairs between 1988 and 2011. Total repairs increased after the introduction of endovascular repair (8.4 in 1988 to 13.8 in 2011 per 10 million U.S. population; P = .03). Endovascular repair increased from 0 in 1988 to 6.4 in 2011 per 10 million U.S. population ( P < .0001). However, there was no concomitant decrease in open surgery (5.5 in 1988 to 7.4 in 2011 per 10 million U.S. population; P = .28). From 2000 to 2011, there were 1627 open and 1082 endovascular elective repairs. Patients undergoing endovascular repair were more likely to have a history of coronary artery disease (18% vs 11%; P < .001), prior myocardial infarction (5.2% vs 1.8%; P < .001), and renal failure (7.7% vs 3.3%; P < .001). In-hospital mortality was 1.8% for endovascular repair, 0.9% for open reconstruction ( P = .037), and 5.4% for nephrectomy ( P < .001 compared with all revascularization). Complication rates were 12.4% for open repair vs 10.5% for endovascular repair ( P = .134), including more cardiac (2.2% vs 0.6%; P = .001) and peripheral vascular complications (0.6% vs 0.0%; P = .014) with open repair. Open repair had a longer length of stay (6.0 vs 4.6 days; P < .001). After adjustment for other predictors of mortality, including age (odds ratio OR, 1.05 per decade; 95% confidence interval CI, 1.0-1.1; P = .001), heart failure (OR, 7.0; 95% CI, 3.1-16.0; P < .001), and dysrhythmia (OR, 5.9; 95% CI, 2.0-16.8; P = .005), endovascular repair was still not protective (OR, 1.6; 95% CI, 0.8-3.2; P = .145). Conclusions More renal artery aneurysms are being treated with the advent of endovascular techniques, without a reduction in operative mortality or a reduction in open surgery. Indications for repair of renal artery aneurysms should be re-evaluated.
Objective This study was conducted to provide insight into the safety, applicability, and outcomes of thoracic endovascular aortic repair (TEVAR) with the chimney graft technique. Methods Original ...data regarding the chimney technique in TEVAR in the emergent and elective setting were collected from MEDLINE, Embase, and Scopus databases. All variables were systematically extracted and included in a database. Patient and procedural characteristics, details, and outcomes were analyzed. Results In total, 94 patients with 101 chimney-stented aortic arch branches were analyzed, consisting of the brachiocephalic artery in 20, the left common carotid artery in 48, and the left subclavian artery in 33. Balloon-expandable stents were used in 36% and self-expandable stents in 64% for the aortic side branch. The interventions were elective in 72% and emergent in 28%. Technical success was achieved in 98% in elective and emergent settings combined. Endoleaks were described in 18%; with type Ia being most frequently reported in 6.4% overall and in 6.5% in the elective setting. Stroke was reported in 5.3% of the patients, of which 40% were fatal. The overall perioperative mortality was 3.2%. Median follow-up time was 11 months, and chimney stents remained patent in all patients. Conclusions TEVAR with the chimney technique is a viable treatment option and may expand treatment strategies for patients with challenging thoracic aortic pathology and anatomy in the emergent and elective setting. Patency of the thoracic chimney stents appears to be good during short-term follow-up. Other complications, such as endoleak and stroke, deserve attention by future research to further improve treatment strategies and the prognosis of these patients.
This study assessed whether the additional use of the aortic arch classification in type I, II, and III may complement Ishimaru's aortic arch map and provide valuable information on the geometry and ...suitability of proximal landing zones for thoracic endovascular aortic repair.
Anonymized thoracic computed tomography scans of healthy aortas were reviewed and stratified according to the aortic arch classification, and 20 of each type of arch were selected. Further processing allowed calculation of angulation and tortuosity of each proximal landing zone. Data were described indicating both proximal landing zone and type of arch (eg, 0/I).
Angulation was severe (>60°) in 2/III and in 3/III. Comparisons among the types of arch showed an increase in proximal landing zones angulation (P < .001) and tortuosity (P = .009) depending on the type of arch. Comparisons within type of arch showed no change in angulation and tortuosity across proximal landing zones within type I arch (P = .349 and P = .409), and increases in angulation and tortuosity toward more distal proximal landing zones within type II (P = .003 and P = .043) and type III (P < .001 in both).
The aortic arch classification is associated with a consistent geometric pattern of the aortic arch map, which identifies specific proximal landing zones with suboptimal angulation for stent graft deployment. Arches II and III also appear to have progressively less favorable anatomy for thoracic endovascular aortic repair compared with arch I.
Objective Prior studies suggest that percutaneous access for endovascular abdominal aortic aneurysm repair (pEVAR) offers significant operative and postoperative benefits compared with femoral ...cutdown (cEVAR). National data on this topic, however, are limited. We compared patient selection and outcomes for elective pEVAR and cEVAR. Methods We identified all patients undergoing either pEVAR (bilateral percutaneous access, whether successful or not) or cEVAR (at least one planned groin cutdown) for abdominal aortic aneurysms from January 2011 to December 2013 in the Targeted Vascular data set from the American College of Surgeons National Surgical Quality Improvement Program database. Emergent cases, ruptures, cases with an iliac conduit, and cases with a preoperative wound infection were excluded. Groups were compared by χ2 test or t-test or the Mann-Whitney test where appropriate. Results We identified 4112 patients undergoing elective EVAR, 3004 cEVAR patients (73%) and 1108 pEVAR patients (27%). Of all EVAR patients, 26% had bilateral percutaneous access; 1.0% had attempted percutaneous access converted to cutdown (4% of pEVARs); and the remainder had a planned cutdown, 63.9% bilateral and 9.1% unilateral. There were no significant differences in age, gender, aneurysm diameter, or prior open abdominal surgery. Patients undergoing cEVAR were less likely to have congestive heart failure (1.5% vs 2.4%; P = .04) but more likely to undergo any concomitant procedure during surgery (32% vs 26%; P < .01) than patients undergoing pEVAR. Postoperatively, pEVAR patients had shorter operative time (mean, 135 vs 152 minutes; P < .01), shorter length of stay (median, 1 day vs 2 days; P < .01), and fewer wound complications (2.1% vs 1.0%; P = .02). On multivariable analysis, the only predictor of percutaneous access failure was performance of any concomitant procedure (odds ratio, 2.0; 95% confidence interval, 1.0-4.0; P = .04). Conclusions Currently, one in four patients treated at Targeted Vascular National Surgical Quality Improvement Program centers are getting pEVAR, which is associated with a high success rate, shorter operation time, shorter length of stay, and fewer wound complications compared with cEVAR.
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