Malperfusion syndromes in aortic dissections

Survival after operative repair of acute type A aortic dissection varies according to the presence and type of preoperative malperfusion

OBJECTIVE

Approximately one-quarter of patients with acute type A aortic dissection (TAAD) present with concomitant malperfusion of coronary arteries, mesenteric circulation, lower extremities, kidneys, brain, and/or coma. It is generally accepted that TAAD patients who present with malperfusion experience higher mortality rates than patients without, although how specific malperfusion syndromes, alone or in combination, affect mortality is not well described.

METHODS

The International Registry of Acute Aortic Dissection database was queried for patients who underwent surgical repair of TAAD. Patients were stratified according to the presence/absence of malperfusion at presentation. Multivariable logistic regression was used to evaluate in-hospital mortality according to malperfusion type. Kaplan-Meier estimates were used to estimate 30-day postoperative survival.

RESULTS

Six thousand four hundred thirty-seven patients underwent surgical repair of acute TAAD, of whom 2642 (41%) had 1 or more preoperative malperfusion syndromes. Mesenteric malperfusion (adjusted odds ratio [AOR], 4.84; P < .001) was associated with the highest odds of in-hospital mortality, followed by coma (AOR, 1.88; P = .007), limb ischemia (AOR, 1.73; P = .008), and coronary malperfusion (AOR, 1.51; P = .02). Renal malperfusion (AOR, 1.37; P = .24) and neurologic deficit (AOR, 1.35; P = .28) were not associated with increased in-hospital mortality. In patients who survived to discharge, there was no difference in 1-year postdischarge survival in the malperfusion and no malperfusion cohorts (P = .36).

CONCLUSIONS

Survival during the index admission after TAAD repair varies according to the presence and type of malperfusion syndromes, with mesenteric malperfusion being associated with the highest odds of in-hospital death. Not only the presence of malperfusion but rather specific malperfusion syndromes should be considered when assessing a patient's risk of undergoing TAAD repair.

Initial Triage and Management of Patients with Acute Aortic Syndromes

The acute aortic syndromes (AAS) are life-threatening vascular compromises within the aortic wall. These include aortic dissection (AD), intramural hematoma (IMH), penetrating aortic ulcer (PAU), and blunt traumatic thoracic aortic injury (BTTAI). While patients classically present with chest pain, the presentation may be highly variable. Timely diagnosis is critical to initiate definitive treatment and maximize chances of survival. In high-risk patients, treatment should begin immediately, even while diagnostic evaluation proceeds. The mainstay of medical therapy is acute reduction of heart rate and blood pressure. Surgical intervention is often required but is informed by patient anatomy and extent of vascular compromise.

A visceral organ function-focused therapeutic strategy using a 6-hour time window for patients with acute type a aortic dissection complicated by mesenteric malperfusion

BACKGROUND

Acute type A aortic dissection (ATAAD) complicated by mesenteric malperfusion is a critical and complicated condition. The optimal treatment strategy remains controversial, debate exists as to whether aortic dissection or mesenteric malperfusion should be addressed first, and the exact time window for mesenteric ischemia intervention is still unclear. To solve this problem, we developed a new concept based on the pathophysiological mechanism of mesenteric ischemia, using a 6-hour time window to divide newly admitted patients by the time from onset to admission, applying different treatment protocols to improve the clinical outcomes of patients with ATAAD complicated by mesenteric malperfusion.

METHODS

This was a retrospective study that covered a five-year period. From July 2018 to December 2020(phase I), all patients underwent emergency open surgery. From January 2021 to June 2023(phase II), patients with an onset within 6 h all underwent open surgical repair, followed by immediately postoperative examination if the malperfusion is suspected, while the restoration of mesenteric perfusion and visceral organ function was performed first, followed by open repair, in patients with an onset beyond 6 h.

RESULTS

There were no significant differences in baseline and surgical data. In phase I, eleven patients with mesenteric malperfusion underwent open surgery, while in phase II, our novel strategy was applied, with sixteen patients with an onset greater than 6 h and eleven patients with an onset less than 6 h. During the waiting period, none died of aortic rupture, but four patients died of organ failure, twelve patients had organ function improvement and underwent surgery successfully survived. The overall mortality rate decreased with the use of this novel strategy (54.55% vs. 18.52%, p = 0.047). Furthermore, the surgical mortality rate between the two periods showed even stronger statistical significance (54.55% vs. 4.35%, p = 0.022). Moreover, the proportions of patients with sepsis and multiorgan failure also showed differences.

CONCLUSIONS

Our novel strategy for patients with ATAAD complicated by mesenteric malperfusion not only improves the surgical success rate but also reduces the overall mortality rate.

Risk factor and correlation between postoperative serum myoglobin and acute kidney injury after pulmonary endarterectomy

Background

Acute kidney injury (AKI) is a common and life-threatening complication following pulmonary endarterectomy (PEA). Our study aimed to investigate the risk factors associated with AKI and evaluate the correlation between serum myoglobin (sMb) levels and postoperative AKI.

Methods

We conducted a retrospective study involving 134 patients who underwent PEA at China-Japan Friendship Hospital. AKI was defined and staged according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

Results

During the study period, the incidence of postoperative AKI was 57.5%, and the associated mortality rate was 6.0%. Severe AKI was found to be significantly associated with worse short-term outcomes (P<0.05). Logarithmically transformed postoperative day (POD) 0 sMb levels were significantly associated with AKI [odds ratio (OR) =5.174; 95% confidence interval (CI), 2.307-11.603; P<0.001] and severe AKI (OR =4.605; 95% CI, 1.510-14.048; P=0.007), also had independent predictive value [area under the curve (AUC) =0.776 in AKI and AUC =0.737 in severe AKI]. The optimal cut-off values were 370.544 ng/mL for AKI and 419.473 ng/mL for severe AKI. Furthermore, albumin concentration was found to play a protective role in the development of severe AKI (OR =0.838; 95% CI, 0.716-0.980; P=0.027) when higher than 40.350 g/L.

Conclusions

Our findings suggest that a high concentration of POD0 sMb may increase the risk of developing AKI following PEA surgery. Increasing albumin concentration could serve as an effective preventive measure against AKI.

Correlation of the serum cell division cycle 42 with CD4+ T cell subsets and in-hospital mortality in Stanford type B aortic dissection patients

Objective

Cell division cycle 42 (CDC42) regulates CD4+ T-cell differentiation and participates in vascular stiffness and atherosclerosis and is involved in the progression of Stanford type B aortic dissection (TBAD). This study aimed to explore the correlation between serum CDC42 level and CD4+ T cell subsets and in-hospital mortality in TBAD patients.

Methods

Serum CDC42 and peripheral blood T-helper (Th) 1, Th2, and Th17 cells were detected in 127 TBAD patients by enzyme-linked immunosorbent assay and flow cytometry, respectively. Serum CDC42 was also quantified in 30 healthy controls.

Results

Serum CDC42 was decreased in TBAD patients vs. healthy controls (median [interquartile range (IQR)]: 418.0 (228.0-761.0) pg/ml vs. 992.0 (716.3-1,445.8) pg/ml, P < 0.001). In TBAD patients, serum CDC42 was negatively correlated with Th17 cells (P = 0.001), but not Th1 (P = 0.130) or Th2 cells (P = 0.098). Seven (5.5%) patients experienced in-hospital mortality. Serum CDC42 was reduced in patients who experienced in-hospital mortality vs. those who did not (median (IQR): 191.0 (145.0-345.0) pg/ml vs. 451.5 (298.3-766.8) pg/ml, P = 0.006). By receiver operating characteristic analysis, serum CDC42 showed a good ability for estimating in-hospital mortality [area under curve = 0.809, 95% confidence interval (CI) = 0.662-0.956]. By the multivariate logistic regression analysis, elevated serum CDC42 [odd ratio (OR) = 0.994, 95% CI = 0.998-1.000, P = 0.043] was independently correlated with lower risk of in-hospital mortality, while higher age (OR = 1.157, 95% CI = 1.017-1.316, P = 0.027) was an independent factor for increased risk of in-hospital mortality.

Conclusion

Serum CDC42 negatively associates with Th17 cells and is independently correlated with decreased in-hospital mortality risk in TBAD patients.

A Severe and Fatal Type A Aortic Dissection in an Adult with a Repaired Tetralogy of Fallot

We report a case of a 44-year-old woman surgically treated for tetralogy of Fallot who experienced an acute and extensive Stanford A type aortic dissection despite the meticulous follow-up. While aortic dilatation is prevalent in individuals with repaired tetralogy of Fallot, aortic dissection represents a rare consequence, that when it appears, is progressive and usually detected during the check-up visits. In the case reported, the dissection was unexpected and severe, and the patient's clinical state worsened suddenly, leading to death after a few days. Constant awareness for aortic aneurysms is essential in the Fallot tetralogy population, nevertheless, several causes may contribute to the acute worsening of the clinical condition until the patient's death.

Lactate-Based Difference as a Determinant of Outcomes following Surgery for Type A Acute Aortic Dissection: A Multi-Centre Study

Type A acute aortic dissection (TAAAD) is a serious condition within the acute aortic syndromes that demands immediate treatment. Despite advancements in diagnostic and referral pathways, the survival rate post-surgery currently sits at almost 20%. Our objective was to pinpoint clinical indicators for mortality and morbidity, particularly raised arterial lactate as a key factor for negative outcomes.

METHODS

All patients referred to the three cardiovascular centres between January 2005 and December 2022 were included in the study. The inclusion criteria required the presence of a lesion involving the ascending aorta, symptoms within 7 days of surgery, and referral for primary surgical repair of TAAAD based on recommendations, with consideration for other concomitant major cardiac surgical procedures needed during TAAAD and retrograde extension of TAAAD. We conducted an analysis of both continuous and categorical variables and utilised predictive mean matching to fill in missing numeric features. For missing binary variables, we used logistic regression to impute values. We specifically targeted early postoperative mortality and employed LASSO regression to minimise potential collinearity of over-fitting variables and variables measured from the same patient.

RESULTS

A total of 633 patients were recruited for the study, out of which 449 patients had complete preoperative arterial lactate data. The average age of the patients was 64 years, and 304 patients were male (67.6%). The crude early postoperative mortality rate was 24.5% (110 out of 449 patients). The mortality rate did not show any significant difference when comparing conservative and extensive surgeries. However, malperfusion had a significant impact on mortality [48/131 (36.6%) vs. 62/318 (19.5%), p < 0.001]. Preoperative arterial lactates were significantly elevated in patients with malperfusion. The optimal prognostic threshold of arterial lactate for predicting early postoperative mortality in our cohort was ≥2.6 mmol/L.

CONCLUSION

The arterial lactate concentration in patients referred for TAAAD is an independent factor for both operative mortality and postoperative complications. In addition to mortality, patients with an upper arterial lactate cut-off of ≥2.6 mmol/L face significant risks of VA ECMO and the need for dialysis within the first 48 h after surgery. To improve recognition and facilitate rapid transfer and surgical treatment protocol, more diligent efforts are required in the management of malperfusion in TAAAD.

The role of delayed aortic surgery in type A aortic dissection and mesenteric ischemia: a systematic review and meta-analysis

INTRODUCTION

Approximately one third of patients with Acute Type A Aortic Dissection (ATAAD) present with pre-operative malperfusion syndromes (MPS). Of these, mesenteric malperfusion represents the greatest risk to patients with respect to increased short-term mortality. In select patients, it may be feasible to offer a staged approach by treating the mesenteric malperfusion first, optimizing the patient in the intensive care setting and then, following with a central aortic repair. The aim of this systematic review is to summarize cohort studies assessing the role of pre-operative interventions for mesenteric malperfusion.

METHODS

An electronic literature search of five databases was performed to identify all relevant studies providing studies examining short-term mortality on patients who underwent either endovascular or open revascularisation of mesenteric ischemia prior to central aortic repair. The primary outcome was all-cause, short-term mortality. Secondary outcomes were comparative mortality between a delayed repair vs. aortic repair first strategy, rates of postoperative laparotomy, bowel resection, and mortality following delayed aortic repair.

RESULTS

The search strategy identified 8 studies qualifying for inclusion, with a total of 180 patients who underwent delayed aortic surgery in the setting of mesenteric MPS. The weighted short-term mortality following a mesenteric revascularisation first, delayed aortic surgery strategy was 22.5%. This strategy was also associated with a significantly lower mortality than a central repair first strategy (OR 0.07, 95% CI 0.02-0.27), and a significantly lower rate of postoperative laparotomy/bowel resection (OR 0.05, 95% CI 0.02-0.14). If patients survive to receive central repair, the weighted short-term mortality postoperatively is low (2.1%).

CONCLUSION

A summary of this evidence reveals a lower short-term mortality in hemodynamically stable patients with mesenteric malperfusion, along with a reduction in postoperative laparotomy/bowel resections. Of those patients who survive to receive central repair, short-term mortality remains very low in the select group of hemodynamically stable patients. Further high-quality studies with randomized or propensity matched data are required to verify these results.

Thoracic Aortic Aneurysms and Arch Disease

Aortic arch and descending thoracic pathology have historically remained in the realm of open surgical repair. Technology is quickly pushing to bring these under the endovascular umbrella, with lower morbidity repairs proving safe in their early experience. Much work remains particularly for acute aortic syndromes, however, to understand who is best treated medically, surgically, endovascularly, or with hybrid approaches.

Calibration of patient-specific boundary conditions for coupled CFD models of the aorta derived from 4D Flow-MRI

Introduction: Patient-specific computational fluid dynamics (CFD) models permit analysis of complex intra-aortic hemodynamics in patients with aortic dissection (AD), where vessel morphology and disease severity are highly individualized. The simulated blood flow regime within these models is sensitive to the prescribed boundary conditions (BCs), so accurate BC selection is fundamental to achieve clinically relevant results. Methods: This study presents a novel reduced-order computational framework for the iterative flow-based calibration of 3-Element Windkessel Model (3EWM) parameters to generate patient-specific BCs. These parameters were calibrated using time-resolved flow information derived from retrospective four-dimensional flow magnetic resonance imaging (4D Flow-MRI). For a healthy and dissected case, blood flow was then investigated numerically in a fully coupled zero dimensional-three dimensional (0D-3D) numerical framework, where the vessel geometries were reconstructed from medical images. Calibration of the 3EWM parameters was automated and required ~3.5 min per branch. Results: With prescription of the calibrated BCs, the computed near-wall hemodynamics (time-averaged wall shear stress, oscillatory shear index) and perfusion distribution were consistent with clinical measurements and previous literature, yielding physiologically relevant results. BC calibration was particularly important in the AD case, where the complex flow regime was captured only after BC calibration. Discussion: This calibration methodology can therefore be applied in clinical cases where branch flow rates are known, for example, via 4D Flow-MRI or ultrasound, to generate patient-specific BCs for CFD models. It is then possible to elucidate, on a case-by-case basis, the highly individualized hemodynamics which occur due to geometric variations in aortic pathology high spatiotemporal resolution through CFD.

Acute aortic dissection

Although substantial progress has been made in the prevention, diagnosis, and treatment of acute aortic dissection, it remains a complex cardiovascular event, with a high immediate mortality and substantial morbidity in individuals surviving the acute period. The past decade has allowed a leap forward in understanding the pathophysiology of this disease; the existing classifications have been challenged, and the scientific community moves towards a nomenclature that is likely to unify the current definitions according to morphology and function. The most important pathophysiological pathway, namely the location and extension of the initial intimal tear, which causes a disruption of the media layer of the aortic wall, together with the size of the affected aortic segments, determines whether the patient should undergo emergency surgery, an endovascular intervention, or receive optimal medical treatment. The scientific evidence for the management and follow-up of acute aortic dissection continues to evolve. This Seminar provides a clinically relevant overview of potential prevention, diagnosis, and management of acute aortic dissection, which is the most severe acute aortic syndrome.

Association between preoperative serum myoglobin and acute kidney injury after Stanford Type A aortic dissection surgery

BACKGROUND

Acute kidney injury (AKI) is a common complication after Type A aortic dissection (TAAD) surgery, and it is associated with poor outcomes. The nephrotoxic effect of myoglobin was established, but its correlation with AKI following TAAD repair still lacks sufficient evidence. We clarified the correlation between preoperative serum myoglobin (pre-sMyo) concentrations and AKI after TAAD surgery.

METHOD

A retrospective analysis was performed on the perioperative data of 382 patients treated with TAAD surgery at Beijing Anzhen Hospital. AKI was defined and classified according to the criteria established by the Kidney Disease: Improving Global Outcomes Acute Kidney Injury Work Group. We attempted to determine the correlation between pre-sMyo concentrations and postoperative AKI.

RESULTS

The incidences of Stage 1, 2, and 3 AKI were 37.3 % (57/153), 23.5 % (36/153), and 39.2 % (60/153), respectively. The pre-sMyo concentrations of the AKI group were significantly increased than the non-AKI group [43.1 (21.4, 107.5) vs 26.4 (18.0, 37.2), P < 0.001]. Pre-sMyo concentrations have a linear correlation with preoperative renal function-related indicators. The multivariable logistic regression analysis showed that Ln (pre-sMyo) was an independent risk factor for AKI. When the pre-sMyo concentration was at the fourth quartile [109.3 (64.8, 213.4) ng/ml], the risk of developing any-stage and severe AKI was significantly increased (OR = 4.333, 95 % CI: 2.364-7.943, P < 0.001; OR = 3.862, 95 %, CI: 2.011-7.419, P < 0.001). This difference persisted after adjustment (OR = 3.830, 95 % CI: 1.848-7.936, P < 0.001; OR = 2.330, 95 % CI: 1.045-5.199, P = 0.039). Furthermore, pre-sMyo concentrations were not affected by lower limb malperfusion, myocardial malperfusion, and cardiac tamponade.

CONCLUSIONS

Increased pre-sMyo concentrations correlated with postoperative AKI in TAAD, which may increase the risk of developing any-stage AKI and severe AKI after TAAD surgery.

Acute Kidney Injury in Patients with Acute Type B Aortic Dissection

OBJECTIVE

Acute kidney injury (AKI) is common in patients with aortic diseases; however, it has not been extensively studied in acute type B aortic dissection (TBAD). AKI is known to be associated with adverse kidney outcomes and premature death. This study investigated the incidence and impact of AKI in patients with acute TBAD.

METHODS

This was a retrospective study including data from two tertiary vascular centres in the UK. Case notes and electronic records were reviewed for consecutive patients presenting with acute symptomatic TBAD. Patients were managed according to a uniform clinical protocol; both patients who underwent surgery and those managed conservatively were included in this analysis. Serum creatinine values were used to calculate the number of patients who developed AKI, based on validated Kidney Disease Improving Global Outcomes definitions. Associations between incidence of AKI, death, and Major Adverse Kidney Events (MAKE; defined as death, dialysis and/or drop in estimated glomerular filtration rate > 25%) were explored.

RESULTS

Overall, 66 (42.6%) of 155 patients developed AKI within one week of presenting with TBAD. Of these, 23 patients (34.8%) had stage 1, 26 patients (39.4%) stage 2, and 17 patients (25.8%) stage 3 AKI. MAKE at 30 and 90 days occurred in 17 (11.0%) and 12 patients (7.7%), respectively. AKI was associated with significantly worse outcomes, with a 24.2% mortality rate in the AKI group compared with 7.8% among those with no AKI (p <.001); this association was also significant in adjusted analyses, both in patients who did and did not undergo surgery.

CONCLUSION

AKI is very common among patients presenting with acute TBAD, even in clinically uncomplicated disease. There was a significant association with mortality and MAKE, whether patients underwent surgery or not. This warrants further investigation to better understand the underlying causes of the AKI and investigate management strategies which may improve outcomes.

Fluid-structure interaction simulation of visceral perfusion and impact of different cannulation methods on aortic dissection

Hemodynamics in aortic dissection (AD) is closely associated with the risk of aortic aneurysm, rupture, and malperfusion. Altered blood flow in patients with AD can lead to severe complications such as visceral malperfusion. In this study, we aimed to investigate the effect of cannulation flow on hemodynamics in AD using a fluid-structure interaction simulation. We developed a specific-idealized AD model that included an intimal tear in the descending thoracic aorta, a re-entry tear in the left iliac artery, and nine branches. Two different cannulation methods were tested: (1) axillary cannulation (AC) only through the brachiocephalic trunk and (2) combined axillary and femoral cannulation (AFC) through the brachiocephalic trunk and the right common iliac artery. AC was found to result in the development of a pressure difference between the true lumen and false lumen, owing to the difference in the flow rate through each lumen. This pressure difference collapsed the true lumen, disturbing blood flow to the celiac and superior mesenteric arteries. However, in AFC, the pressure levels between the two lumens were similar, and no collapse occurred. Moreover, the visceral flow was higher than that in AC. Lastly, the stiffness of the intimal flap affected the true lumen's collapse.

Predictive value of admission CO2 combining power combined with serum sodium for the prognosis in acute Stanford type A aortic dissection patients

Acute Stanford type A aortic dissection (ATAAD) with sudden onset and high mortality requiries a standard Bentall operation and a accurate prognosis in common, together with alteration of CO₂ combining power (CO₂CP) and serum sodium rase concern, hence, we evaluated the prognostic value of CO₂CP combined with serum sodium in ATAAD patients. This retrospective study included 183 patients who underwent Bentall operation for ATAAD from 2015 to 2021 in the Fourth Hospital of Hebei Medical University, subsequently followed grouping by the levels of CO₂CP and serum sodium. The study endpoint was 30-day all-cause mortality, and the prognostic value of CO₂CP combined with serum sodium levels in ATAAD patients were evaluated with multivariate logistic regression method. The postoperative incidence of in-hospital death and adverse events in patients with ATAAD were 18% and 25.7%, respectively. Combination of CO₂CP and serum sodium for predicting ATAAD death and adverse events presented a higher predictive value than each single indicator with ROC curve analysis (the AUC of CO₂CP combined with serum sodium was 0.786, 95% CI 0.706-0.869, P < 0.001), along with CO₂CP < 22.5 mmol/L + serum sodium > 138.5 mmol/L group had the worst prognostic. Multivariate regression analyse showed that CO₂CP < 22.5 mmol/L combined with serum sodium > 138.5 mmol/L preferably predicted the prognosis of ATAAD (OR =6.073, 95% CI 2.557-14.425, P < 0.001). Consistently, the cumulative 30-day survival after surgery in ATAAD patients with the low CO₂CP and high serum sodium simultaneously was the worst (log-rank P < 0.05). The combination of CO₂CP and serum sodium increases the predictive value of prognosis, which is conducive to risk stratification of patients with ATAAD.

Open aortic septectomy for complicated type B aortic dissection

Malperfusion is a complication of acute aortic dissection associated with substantially increased morbidity and mortality. Although endovascular treatment of the dissection with a stent graft to cover the intimal tear and reexpand the true lumen will often be sufficient to treat distal malperfusion, persistent or delayed malperfusion will necessitate additional interventions. Endovascular strategies to increase true lumen expansion include bare metal dissection stent placement and percutaneous fenestration. However, for patients with anatomy not amenable to an endovascular approach, alternative techniques are required. We describe two cases of complicated acute aortic dissection due to partial false lumen thrombosis treated with open aortic septectomy. Although an uncommon procedure, open septectomy can be useful for patients with malperfusion syndromes without appropriate endovascular options.

Changing Management of Type B Aortic Dissections

The purpose of this manuscript is to review recent trends in the management of acute type B aortic dissection. Due to its efficacy and low morbidity, thoracic endografting has rapidly been adopted as the treatment of choice for most patients with malperfusion or rupture as a consequence of acute aortic dissection. This technology is increasingly applied to patients without rupture or malperfusion, so-called "uncomplicated" dissections, to reduce the incidence of late aneurysmal degeneration in the ungrafted segments of the thoracoabdominal aorta. A variety of techniques have been proposed, including intentional rupture of the dissection membrane to obliterate the false lumen as well as the candy-plug technique to eliminate retrograde flow in the false lumen.

Onset of pain to surgery time in acute aortic dissections type A: a mandatory factor for evaluating surgical results?

Objective

An acute aortic dissection type A (AADA) is a rare but life-threatening event. The mortality rate ranges between 18% to 28% and mortality is often within the first 24 h and up to 1%-2% per hour. Although the onset of pain to surgery time has not been a relevant factor in terms of research in the field of AADA, we hypothesize that a patient's preoperative conditions depend on the length of this time.

Methods

Between January 2000 and January 2018, 430 patients received surgical treatment for acute aortic dissection DeBakey type I at our tertiary referral hospital. In 11 patients, the exact time point of initial onset of pain was retrospectively not detectable. Accordingly, a total of 419 patients were included in the study. The cohort was categorized into two groups: Group A with an onset of pain to surgery time < 6 h (n = 211) and Group B > 6 h (n = 208), respectively.

Results

Median age was 63.5 years (y) ((IQR: 53.3-71.4 y); (67.5% male)). Preoperative conditions differed significantly between the cohorts. Differences were detected in terms of malperfusion (A: 39.3%; B: 23.6%; P: 0.001), neurological symptoms (A: 24.2%; B: 15.4%; P: 0.024), and the dissection of supra-aortic arteries (A: 25.1%; B: 16.8%; P: 0.037). In particular, cerebral malperfusion (A 15.2%: B: 8.2%; P: 0.026) and limb malperfusion (A: 18%, B: 10.1%; P: 0.020) were significantly increased in Group A. Furthermore, Group A showed a decreased median survival time (A: 1,359.0 d; B: 2,247.5 d; P: 0.001), extended ventilation time (A: 53.0 h; B: 44.0 h; P: 0.249) and higher 30-day mortality rate (A: 25.1%; B: 17.3%; P: 0.051).

Conclusions

Patients with a short onset of pain to surgery time in cases of AADA present themselves not only with more severe preoperative symptoms but are also the more compromised cohort. Despite early presentation and emergency aortic repair, these patients show increased chances of early mortality. The "onset of pain to surgery time" should become a mandatory factor when making comparable surgical evaluations in the field of AADA.

Acute aortic syndromes: An internist's guide to the galaxy

Acute aortic syndromes (AASs) are severe conditions defined by dissection, hemorrhage, ulceration or rupture of the thoracic aorta. AASs share etiological and pathophysiological features, including long-term aortic tissue degeneration and mechanisms of acute aortic damage. The clinical signs and symptoms of AASs are unspecific and heterogeneous, requiring large differential diagnosis. When evaluating a patient with AAS-compatible symptoms, physicians need to integrate clinical probability assessment, bedside imaging techniques such as point-of-care ultrasound, and blood test results such as d-dimer. The natural history of AASs is dominated by engagement of ischemic, coagulative and inflammatory pathways at large, causing multiorgan damage. Medical treatment, multiorgan monitoring and outcome prognostication are therefore paramount, with internal medicine playing a key role in non-surgical management of AASs.

Staged Hybrid Repair of a Complex Type B Aortic Dissection

Due to its heterogeneous clinical picture and lengthy evolution, the management of type B aortic dissection represents a clinical challenge, often calling for complex strategies combining medical, endovascular, and open surgical strategies. We present the case of a 45-year-old female who had previously suffered a complicated type B aortic dissection requiring a femoro-femoral crossover bypass and further conservative treatment. Seven years later, due to an aneurysmal development, a staged descending aortic management was strategized, beginning with the implantation of a frozen elephant trunk device due to an insufficient proximal landing zone for endovascular repair. However, the development of a distal stent graft-induced new entry complicated the dissection and led to the formation of a second false lumen, thus prompting an expedited hybrid reconstruction. We describe a hybrid repair strategy tailored to the patient’s particular aortic anatomic conformation, combining ilio-visceral debranching and thoracic endovascular aortic repair. Due to a lack of consensus on the ideal management strategy for type B aortic dissection, an individualized approach conducted by an experienced aortic team may generate the best outcome. The appropriate timing and planning of the intervention are the keys to successful results in complex type B aortic dissection cases with an elaborate anatomic conformation.

Malperfusion syndrome in acute type A aortic dissection: Thinking beyond the proximal repair

BACKGROUND AND OBJECTIVE

Malperfusion syndrome (MPS) is associated with the highest mortality and major morbidity risk in patients with acute Type A aortic dissection (TAAD). The timing of the open proximal aortic repair in the presence of MPS remains debatable given variability in clinical presentation and different local treatment algorithms. This paper provides an up to date and comprehensive overview of published outcomes and available techniques for addressing malperfusion in the setting of acute TAAD.

METHODS

We have reviewed published data from the major aortic dissection registries including the International Registry of Acute Aortic Dissection, the German Registry for Acute Aortic Dissection In Type A, and the Nordic Consortium for Acute Type A Aortic Dissection, as well as the most up to date literature involving malperfusion in the setting of acute TAAD. This data highlights unique strategies that have been adopted at aortic centers internationally to address malperfusion in this setting pre-, intra-, and postoperatively, which are summarized here and may be of great clinical benefit to other centers treating this disease with more traditional methods.

RESULTS

The review of the available data has definitively shown an increased mortality up to 43% and morbidity in patients presenting with MPS in the setting of acute TAAD. More specifically, preoperative MPS has been shown to be an independent predictor of mortality with mesenteric malperfusion associated with the worst mortality outcomes from 70% to 100%. Addressing MPS pre or intraoperatively is associated with significantly reduced mortality outcomes down to 4%-13%.

CONCLUSION

Adapting a dynamic and easily accessible diagnostic method for the comprehensive assessment of different forms of malperfusion (dynamic/static) and incorporating it within the surgical plan is the first step toward early diagnosis and prevention of malperfusion related complications.

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 of patients with acute type A aortic dissection and concomitant lower extremity malperfusion

OBJECTIVE

The occurrence of acute lower limb ischemia (ALLI) is a serious risk within the context of aortic dissection repair. The aim of the present study was to examine the outcomes of patients with acute type A aortic dissection (ATAD) and concomitant lower extremity malperfusion.

METHODS

We performed a retrospective medical record review at our tertiary referral center of patients who underwent ATAD repair from January 2002 to June 2018. We used univariate and multivariate analyses to compare the outcomes of patients with and without lower extremity malperfusion. The primary outcomes were 30-day and 1-year mortality.

RESULTS

A total of 378 patients underwent ATAD repair during the study period. Their mean age was 57 years, 68% were men, and 51% were White. A total of 62 patients (16%) presented with concomitant ALLI, including 35 (9%) who presented with isolated ALLI and 27 (7%) who presented with ALLI and concomitant malperfusion of at least one other organ. Of the 62 patients with ALLI, 46 underwent only proximal aortic repair. Of the 378 patients, 6 died within the first 24 hours, and their limb perfusion was not assessed. Among the 40 patients who underwent isolated proximal repair and survived >24 hours, 34 (85%) had resolution of their ALLI. Of the 16 patients who underwent concomitant lower extremity peripheral vascular procedures, 10 had bypass procedures and 1 died within 24 hours due to refractory coagulopathy and hypotension. All six patients with adequate follow-up imaging studies had asymptomatic occlusion of the bypass graft with recanalization of the occluded native arteries. Patients who presented with any organ malperfusion had increased 30-day (odds ratio, 1.8; P = .04) and 1-year (odds ratio, 1.8; P = .04) mortality and decreased overall survival (P < .01). For the patients with isolated ALLI, no significant differences were found in 30-day or 1-year mortality or overall survival (P = .57).

CONCLUSIONS

Proximal repair of ATAD resolves most cases of associated ALLI, and isolated ALLI does not affect short- or long-term survival. All patients with follow-up in our study who underwent extra-anatomic bypass developed asymptomatic graft occlusion, which could be attributed to competitive flow from the remodeled native arterial system. We believe that rapid and aggressive restoration of flow to the lower extremity is the best method to treat ALLI malperfusion syndrome. Close monitoring for the development of compartment syndrome is recommended.

[Acute Aortic Dissection: A Life-Threatening Disease Also in Neurological Emergency Medicine]

Acute aortic dissection is rare but life-threatening. The symptoms depend on the localization and reduced perfusion of the downstream organs or limbs and are therefore variable. Neurological symptoms may occur that do not immediately lead to a diagnosis and thus delay the necessary therapy. Knowing the early symptoms and warning signs of aortic dissection is therefore also crucial in neurological emergency care for quickly identifying the affected patients and for providing acute therapy. A misdiagnosis with delayed initiation of therapy can significantly worsen the patient's outcome. This study aims to establish a standardized diagnostic and therapeutic algorithm for suspected acute aortic dissection in neurological emergency care. Close interdisciplinary cooperation is mandatory.

Evaluation of Remodeling of Visceral Arteries and Impact on Renal Function Post-endovascular Repair of Type B Aortic Dissection Vis-A-Vis Baseline Visceral Artery Morphology

PURPOSE

To evaluate the remodeling of visceral arteries post-endovascular repair (TEVAR) of type B aortic dissection and to investigate interval change in renal volume and estimated glomerular filtration rate (eGFR) vis-a-vis baseline visceral artery morphology.

MATERIALS AND METHODS

All patients of type B aortic dissection who underwent TEVAR with a baseline and follow-up CT during the study period were included. Baseline morphology of visceral arteries (celiac, superior, and inferior mesenteric artery and bilateral renal artery) were classified into 7 patterns depending upon the origin of the artery (from true/false lumen) and the extension of dissection flap, while occluded vessels were categorized as pattern 8.

RESULTS

One hundred and thirty-two branches were analyzed in 25 patients (23 males; mean age: 50.1 years) with a mean follow-up of 386 days. 51 visceral branches were arising from the true lumen without any stenosis. Of the remaining 81 branches, 48 showed favorable remodeling (P = .0001). The highest incidence of favorable remodeling was observed in arteries arising from the true lumen (pattern 2,3: 44/48; 91.6%) whereas only one thrombosed and artery arising from the false lumen each (pattern 5 and 8) showed favorable remodeling. Kidneys perfused by false lumen or occluded renal artery suffered statistically significant volume loss compared to kidneys perfused by true or both lumens (-16.5% vs .2%; P = .01); however, the change in eGFR failed to reach statistical significance.

CONCLUSION

Visceral arteries arising from the true lumen are more likely to undergo favorable remodeling. The kidneys supplied by false lumen or by occluded renal artery suffer significantly more volume loss after TEVAR.

Recovery of neurological function following type B aortic dissection complicated by paraplegia

A woman in her 50s presented with uncontrolled hypertension, chest/back pain, paraplegia, right lower limb ischaemia and acute kidney injury. A CT angiogram demonstrated a type B aortic dissection originating distal to the left subclavian artery to bilateral common iliac arteries complicated by occlusion of the right renal artery and right common iliac artery. She was started on intravenous antihypertensive therapy and transferred to our institution for emergent thoracic endovascular aortic repair. Due to bleeding risk from coagulopathy, a spinal drain was not placed immediately post-operatively but instead was inserted after 24 hours while maintaining a mean arterial pressure of 80-100 mm Hg. Postoperatively, her right lower extremity perfusion was re-established, and her renal function recovered following temporary dialysis. At discharge on postoperative day 13, she regained full neurological function.

Impact of true or false lumen renal perfusion after type B aortic dissection on renal volume

BACKGROUND

The aim of this study was to analyse the influence of true, false, and combined lumen perfusion of renal arteries on mid- and long-term kidney volume in patients with type B aortic dissection (TBAD).

METHODS

Retrospective analysis of patients diagnosed with a TBAD between 2008 and 2015 in a single high-volume European center. The origin of the renal arteries was evaluated on a dedicated 3D workstation (TeraRecon Inc., San Mateo, CA, USA) and coded as either arising from the true lumen (TL), false lumen (FL) or from a combination of both (CL). Additional evaluated anatomical parameters were renal volume, length, width, and depth of the kidneys. Measurements were recorded at the time of diagnosis (T0) and at 1-month (T1), 6-months (T2), 18-months (T3) and 36-month of follow-up time (T4).

RESULTS

A total of 131 renal arteries and kidneys were evaluated in 69 patients. Mean age was 64±13 years and 77% were male. The absolute number and percentage of assessed renal arteries/kidneys was 131 (100%) at T0, 89 (68%) at T1, 73 (56%) at T2, 57 (44%) at T3 and 43 (44%) at T4. At the time of diagnosis, 71.6% renal arteries originated from the TL, 19.1% from the FL and 9.2% from a CL. TEVAR was performed in 92.7% patients and nine patients had additional renal artery stenting. At T0 the mean renal volume was 212.1±70.9cm³, 178±61.2 in women versus 222.2±70.6 in men (P=0.002). Forty-three percent of the patients had a renal volume reduction ≥15% from T0 to their last available CTA. Mixed model analysis showed a significant overall renal volume reduction of 13.7cm³ from T0 to T4 (P<0.05). No significant differences in renal-volume reduction were observed depending on origin of the renal artery, though an estimated reduction of renal volume from T0 to T4 of 40.8 cm³ was seen when the kidneys were perfused by a CL, while TL perfusion only caused a reduction of 15.6 cm³ and no relevant volume change over time was observed when the renal artery originated from FL. Alongside a renal volume reduction, mixed model analysis also showed a significant serum-creatinine increase, from 0.8618mg/at T0 to 1.38±0.56 mg/dL at T4 (P<0.001), as well as a significant glomerular filtration rate reduction over time, from > 60mL/min at T0 to 49±13 mL/min at T4 (P<0.001). A negative correlation was observed between creatinine values and renal volume change, while a positive correlation was observed between GFR and renal volume change (P<0.001).

CONCLUSIONS

There is a significant mid-term renal-volume reduction in patients with TBAD, independent of the origin of the renal arteries. Albeit not statistically significant, combined renal artery perfusion may lead to a greater volume reduction, potentially secondary to a relevant dynamic compression by the dissection membrane. Further multicentre studies are warranted to determine the effect on long-term renal function and on possible preventive strategies.

"Time is aorta?": Timeliness of surgical repair in type A aortic dissection

Acute type A aortic dissection is a life‐threatening event that requires prompt management, a complex interaction among the timing of aortic surgical repair, presence or absence of organ malperfusion, and surgical outcomes exists. Whether resection of intimal entry tear should be deferred after reversal of malperfusion and end‐organ ischemia is a matter of controversy. In fact, the timing of aortic repair should be considered within the clinical presentation and baseline characteristics of each patient. Moreover, every effort should be made to minimize times between symptom onset, diagnosis, and surgery.

Hemodynamic Study of Stanford Type B Aortic Dissection Based on Ex Vivo Porcine Aorta Models

Background:

In this study, we aimed to evaluate hemodynamic influence of the dissected aortic system via various ex vivo type B aortic dissection (AD) models.

Methods:

Twenty-four raw porcine aortas were harvested and randomly divided into 4 groups to create various aortic models. Model A was the control group, while models B to D indicated the AD group, where models B and C presented a proximal primary entry with the false lumen (FL) lengths of 15 and 20 cm, respectively, and model D presented a 20 cm FL with a proximal primary entry and a distal reentry. All the aortic models were connected to a mock circulation loop to attain the realistic flow and pressure status. The flow distribution rate (FDR) of the aortic branches was calculated. Doppler ultrasound was applied to visualize the AD structure and to attain the velocity of flow in both the true and false lumens. Several sections of the AD were stained with hematoxylin and eosin for histologic evaluation after the experiment.

Results:

This study demonstrated that higher pressures were found for the AD group compared with the control group. The mean systolic pressures at the inlet of models A to D were 113.34±0.81, 120.58±0.52, 117.76±0.82, and 115.87±0.42 mm Hg, respectively. The FDRs of the celiac artery in models A to D were 8.65%, 8.32%±0.15%, 7.87%±0.13%, and 8.03%±0.21%, respectively. By ultrasound visualization, the velocity of the flow at the entry to the FL in the AD group ranged in 10 to 92 cm/s. The dissection flap presented pulsatile movement, especially in the models B and C which contained 1 primary entry without distal reentries. Histological examinations indicated that AD was located between the intimal and medial layers.

Conclusions:

Our ex vivo models demonstrated that the configuration of the dissected aorta influenced the pressure distribution. Moreover, the dissection flap affected the FDR of the aortic branches that possibly inducing malperfusion syndrome.

Malperfusion in acute type A aortic dissection: how we handle the challenge?

Malperfusion syndrome (MPS) complicating acute type A aortic dissection (ATAAD) poses a continuing challenge and management dilemma for cardiovascular surgeons. MPS may involve any of the major arterial side branches resulting in myocardial, cerebral, spinal cord, visceral, and/or limb ischemia with varying frequency and severity. Despite the continuous improvement in diagnosis and management strategies for MPS with ATAAD, clinical outcomes remain poor and the optimal therapy is still debatable. The present review aimed to assess current evidence on ATAAD patients with MPS and how best to handle the challenge.

Imaging features of renal malperfusion in aortic dissection

OBJECTIVES

Malperfusion syndrome accompanying aortic dissection is an independent predictor of death with in-hospital mortality rates >60%. Asymmetrically decreased renal enhancement on computed tomography angiography is often considered evidence of renal malperfusion. We investigated the associations between renal enhancement, baseline laboratory values and the diagnosis of renal malperfusion, as defined by invasive manometry, among patients with aortic dissection.

METHODS

In this retrospective cohort study, we included all patients who were referred to our institution with acute dissection and suspected visceral malperfusion between 2010 and 2020. We determined asymmetric renal enhancement by visual assessment and quantitative density measurements of the renal cortex. We collected invasive renal artery pressures during invasive angiography at the aortic root and in the renal arteries. Logistic regression was performed to evaluate independent predictors of renal malperfusion.

RESULTS

Among the 161 patients analysed, the majority of patients were male (78%) and had type A dissection (52%). Invasive angiography confirmed suspected renal malperfusion in 83% of patients. Global asymmetric renal enhancement was seen in 42% of patients who did not have renal malperfusion during invasive angiography. Asymmetrically decreased renal enhancement was 65% sensitive and 58% specific for renal malperfusion. Both global [odds ratio (OR) 4.43; 1.20-16.41, P = 0.03] and focal (OR 11.23; 1.12-112.90, P = 0.04) enhancement defects were independent predictors for renal malperfusion.

CONCLUSIONS

In patients with aortic dissection, we found that differential enhancement of the kidney as seen on the computed tomography angiography is predictive, but not prescriptive for renal malperfusion. While detection of renal malperfusion is aided by computed tomography angiography, its diagnosis requires close monitoring and often invasive assessment.

Renal Artery Partial Occlusion After Aortic Dissection Is Associated With Impaired Renal Function in the Affected Kidney

BACKGROUND

The renal artery is often involved in aortic dissection, leading to kidney ischaemia and renal dysfunction. However, some patients with aortic dissection with combined renal artery involvement do not show clinical renal dysfunction. This study aimed to analyse the relationship between renal artery involvement and renal function.

METHODS

Data and images were collected from 79 patients (Group A), in Beijing Anzhen hospital between January 2015 and December 2017, who had type A aortic dissection, in order to analyse the relationship between renal artery involvement and serum creatinine. In order to further analyse the relationship between renal artery involvement and single kidney function, data from 27 patients (Group B) with aortic dissection from August 2018 to October 2018 were collected. Renal dynamic imaging was conducted, and clinical and image data were recorded.

RESULTS

Results showed that patients with one partially occluded renal artery had higher variance of serum creatinine after surgery compared with patients with one false-lumen renal artery (5.8±22.7 umol/L versus -18.7±22.7 umol/L; p=0.003). The glomerular filtration rate of a single kidney that had a partially occluded renal artery was lower than that of a single kidney with a normal renal artery (37.77±9.57 versus 42.73±10.54; p=0.04).

CONCLUSIONS

A partially occluded renal artery in aortic dissection was associated with impaired renal function after surgery, even though patients did not present high serum creatinine. More attention should be paid to those experiencing aortic dissection.

Risk factors of acute kidney injury in patients with Stanford type B aortic dissection involving the renal artery who underwent thoracic endovascular aortic repair

Background

Acute kidney injury (AKI) is one of the most common and serious complications in patients with type B aortic dissection (TBAD). This study aimed at investigating the incidence and risk factors of in-hospital AKI in TBAD patients involving the renal artery who underwent thoracic endovascular aortic repair (TEVAR) only.

Methods

A total of 256 patients who were diagnosed as TBAD combined with renal artery involvement were included in this retrospective study. All patients were divided into the AKI group and the non-AKI group according to the KDIGO criteria. The risk factors for AKI were identified using a multivariate logistic regression model.

Results

A total of 256 patients were included in this study, and the incidence of AKI was 18% (46/256). Patients in the AKI group were more likely to have a higher proportion of the youth, a higher level of body mass index, and a shorter time from onset to admission. Multivariate logistic regression analysis revealed that the youth (age ≤40 years) (OR: 2.853, 95%CI: 1.061–7.668, p = .038) were prone to AKI, and lower estimated glomerular filtration rate (eGFR) (OR: 1.526, per 15-ml/min/1.73 m² decrease, 95%CI: 1.114–2.092; p = .009), higher diastolic blood pressure (DBP) (OR: 1.418, per 10-mmHg increase; 95%CI: 1.070–1.879; p = .015), and fasting blood glucose (FBG) ≥7 mmol/L on admission (OR: 2.592; 95%CI: 1.299–5.174; p = .007) were independent risk factors for AKI.

Conclusions

Higher incidence of AKI had been perceived in this study, most of them were young and middle-aged patients. Renopreventive measures should be considered in those high-risk patients with younger age, lower eGFR, higher DBP, and higher FBG on admission.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Endovascular therapies for Type B Aortic Dissection

Aortic dissection is a life-threatening condition resulting from a tear in the intimal layer of the aorta, requiring emergent diagnosis and prompt multi-disciplinary management strategy for best patient outcomes. While type A dissection involving ascending aorta is best managed surgically due to high early mortality, type B aortic dissection (TBAD) involving descending aorta generally has better outcomes with conservative management and medical therapy as primary strategy is favored. However, there has been a recent paradigm shift in management of TBAD due to late aneurysmal degeneration of TBAD increasing morbidity and mortality at longer-term. Late surgical intervention can be prevented by early endovascular intervention when combined with optimal medical therapy. In this narrative review, we explore available literature on different endovascular therapies for TBAD in different populations of patients.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.

Beyond Atherosclerosis and Fibromuscular Dysplasia: Rare Causes of Renovascular Hypertension

Renovascular hypertension is one of the most common forms of secondary hypertension. Over 95% of cases of renovascular hypertension are due either to atherosclerosis of the main renal artery trunks or to fibromuscular dysplasia. These two causes of renal artery stenosis have been extensively discussed in recent reviews and consensus. The aim of the current article is to provide comprehensive and up-to-date information on the remaining causes. While these causes are rare or extremely rare, etiologic and differential diagnosis matters both for prognosis and management. Therefore, the clinician cannot ignore them. For didactic reasons, we have grouped these different entities into stenotic lesions (neurofibromatosis type 1 and other rare syndromes, dissection, arteritis, and segmental arterial mediolysis) often associated with aortic coarctation and other arterial abnormalities, and nonstenotic lesions, where hypertension is secondary to compression of adjacent arteries and changes in arterial pulsatility (aneurysm) or to the formation of a shunt, leading to kidney ischemia (arteriovenous fistula). Finally, thrombotic disorders of the renal artery may also be responsible for renovascular hypertension. Although thrombotic/embolic lesions do not represent primary vessel wall disease, they are characterized by frequent macrovascular involvement. In this review, we illustrate the most characteristic aspects of these different entities responsible for renovascular hypertension and discuss their prevalence, pathophysiology, clinical presentation, management, and prognosis.