Risk of Ascending Aortic Aneurysm in Patients With Autosomal Dominant Polycystic Kidney Disease

Splenic artery aneurysm: a rare complication of autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is an important cause of renal dysfunction. It is the most common genetic disorder leading to end-stage kidney disease requiring dialysis. ADPKD is a multisystem disease and is linked to several extra renal abnormalities. Splenic artery aneurysms are rare in the general population. ADPKD is associated with cerebral artery aneurysms. However, splenic artery aneurysms are not a well-recognised complication of ADPKD. We report an unusual case of a splenic artery aneurysm found incidentally on abdominal CT imaging of a woman with known ADPKD.

Aortic Dilatation in Children and Young People With ADPKD

Introduction

Aortic root dilatation is a reported cardiovascular sequela seen in children and young people (CYP) with chronic kidney disease (CKD) but has yet to be described in those with autosomal dominant polycystic kidney disease (ADPKD).

Methods

Single center, cross-sectional study in a dedicated ADPKD clinic. Echocardiograms were evaluated for the presence of dilatation (defined by a z-score ≥2 [≥99th percentile] SDs from the mean) at 4 standardized locations, namely the aortic valve annulus, sinuses of Valsalva (SoV), sinotubular junction (STJ), and the ascending aorta. Measurements were compared with a control group to assess prevalence, severity, and determinants of aortic dilatation.

Results

Ninety-seven children, median age (interquartile range) of 9.3 (6.1, 13.6) years were compared with 19 controls without ADPKD or other CKD. The prevalence of dilatation ranged from 5.2% to 17% in ADPKD, depending on anatomical location with no aortic dilatation identified in the control group. In multivariable regression, aortic root dilatation was significantly associated with cyst burden at the aortic valve annulus and SoV (β = 0.42 and β = 0.39, both P < 0.001), with age at SoV (β = -0.26, P = 0.02), systolic blood pressure (SBP) z-score at SoV (β = -0.20, P = 0.04) and left ventricular mass index (LVMI) at SoV and STJ (β = 0.24, P = 0.02 and β = 0.25, P = 0.03, respectively) following adjustment for age, sex (male or female), body mass index (BMI) z-score, estimated glomerular filtration rate (eGFR), SBP z-score, and LVMI.

Conclusion

Our data suggests increased prevalence of aortic root and ascending aortic dilatation in CYP with ADPKD compared with controls. Further studies are needed to understand the pathogenesis and its contribution to the high cardiovascular morbidity in ADPKD.

Heritable thoracic aortic disease: a literature review on genetic aortopathies and current surgical management

Heritable thoracic aortic disease puts patients at risk for aortic aneurysms, rupture, and dissections. The diagnosis and management of this heterogenous patient population continues to evolve. Last year, the American Heart Association/American College of Cardiology Joint Committee published diagnosis and management guidelines for aortic disease, which included those with genetic aortopathies. Additionally, evolving research studying the implications of underlying genetic aberrations with new genetic testing continues to become available. In this review, we evaluate the current literature surrounding the diagnosis and management of heritable thoracic aortic disease, as well as novel therapeutic approaches and future directions of research.

Clinical findings, underlying pathogenetic processes and treatment of vascular dysfunction in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder characterized by the development of fluid-filled cysts in the kidneys. The primary cause of ADPKD is mutations in the PKD1 (polycystic kidney disease 1) or PKD2 (polycystic kidney disease 2) gene. Patients with ADPKD often develop a variety of vascular abnormalities, which have a major impact on the structure and function of the blood vessels and can lead to complications such as hypertension, intracranial aneurysm (ICAN), and atherosclerosis. The progression of ADPKD involves intricate molecular and cellular processes that lead to the development of these vascular abnormalities. Our understanding of these processes remains incomplete, and available treatment options are limited. The aim of this review is to delve into the underlying mechanisms of these vascular abnormalities and to explore potential interventions.

Vascular Complications in Autosomal Dominant Polycystic Kidney Disease: Perspectives, Paradigms, and Current State of Play

Autosomal dominant polycystic kidney disease (ADPKD) is the leading cause of inherited kidney disease with significant contributions to CKD and end-stage kidney disease. The underlying polycystin proteins (PC1 and PC2) have widespread tissue expression and complex functional roles making ADPKD a systemic disease. Vascular complications, particularly intracranial aneurysms (ICA) are the most feared due to their potential for devastating neurological complications and sudden death. Intracranial aneurysms occur in 8-12% of all patients with ADPKD, but the risk is intensified 4-5-fold in those with a positive family history. The basis for this genetic risk is not well understood and could conceivably be due to features of the germline mutation with a significant contribution of other genetic modifiers and/or environmental factors. Here we review what is known about the natural history and genetics of unruptured ICA in ADPKD including the prevalence and risk factors for aneurysm formation and subarachnoid hemorrhage. We discuss two alternative screening strategies and recommend a practical algorithm that targets those at highest risk for ICA with a positive family history for screening.

Management of Hypertension and Associated Cardiovascular Disease in Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease is the most commonly inherited disease of the kidneys affecting an estimated 12,000,000 people in the world. Autosomal dominant polycystic kidney disease is a systemic disease, with a wide range of associated features that includes hypertension, valvular heart diseases, cerebral aneurysms, aortic aneurysms, liver cysts, abdominal hernias, diverticulosis, gross hematuria, urinary tract infections, nephrolithiasis, pancreatic cysts, and seminal vesicle cysts. The cardiovascular anomalies are somewhat different than in the general population and also chronic kidney disease population, with higher morbidity and mortality rates. This review will focus on cardiovascular diseases associated with autosomal dominant polycystic kidney disease and their management.

Marfan Syndrome: Enhanced Diagnostic Tools and Follow-up Management Strategies

Marfan syndrome (MFS) is a rare inherited autosomic disorder, which encompasses a variety of systemic manifestations caused by mutations in the Fibrillin-1 encoding gene (FBN1). Cardinal clinical phenotypes of MFS are highly variable in terms of severity, and commonly involve cardiovascular, ocular, and musculoskeletal systems with a wide range of manifestations, such as ascending aorta aneurysms and dissection, mitral valve prolapse, ectopia lentis and long bone overgrowth, respectively. Of note, an accurate and prompt diagnosis is pivotal in order to provide the best treatment to the patients as early as possible. To date, the diagnosis of the syndrome has relied upon a systemic score calculation as well as DNA mutation identification. The aim of this review is to summarize the latest MFS evidence regarding the definition, differences and similarities with other connective tissue pathologies with severe systemic phenotypes (e.g., Autosomal dominant Weill-Marchesani syndrome, Loeys-Dietz syndrome, Ehlers-Danlos syndrome) and clinical assessment. In this regard, the management of MFS requires a multidisciplinary team in order to accurately control the evolution of the most severe and potentially life-threatening complications. Based on recent findings in the literature and our clinical experience, we propose a multidisciplinary approach involving specialists in different clinical fields (i.e., cardiologists, surgeons, ophthalmologists, orthopedics, pneumologists, neurologists, endocrinologists, geneticists, and psychologists) to comprehensively characterize, treat, and manage MFS patients with a personalized medicine approach.

Wall Tension and Tubular Resistance in Kidney Cystic Conditions

The progressive formation of single or multiple cysts accompanies several renal diseases. Specifically, (i) genetic forms, such as adult dominant polycystic kidney disease (ADPKD), and (ii) acquired cystic kidney disease (ACKD) are probably the most frequent forms of cystic diseases. Adult dominant polycystic kidney disease (ADPKD) is a genetic disorder characterized by multiple kidney cysts and systemic alterations. The genes responsible for the condition are known, and a large amount of literature focuses on the molecular description of the mechanism. The present manuscript shows that a multiscale approach that considers supramolecular physical phenomena captures the characteristics of both ADPKD and acquired cystic kidney disease (ACKD) from the pathogenetic and therapeutical point of view, potentially suggesting future treatments. We first review the hypothesis of cystogenesis in ADPKD and then focus on ACKD, showing that they share essential pathogenetic features, which can be explained by a localized obstruction of a tubule and/or an alteration of the tubular wall tension. The consequent tubular aneurysms (cysts) follow Laplace's law. Reviewing the public databases, we show that ADPKD genes are widely expressed in various organs, and these proteins interact with the extracellular matrix, thus potentially modifying wall tension. At the kidney and liver level, the authors suggest that altered cell polarity/secretion/proliferation produce tubular regions of high resistance to the urine/bile flow. The increased intratubular pressure upstream increases the difference between the inside (Pi) and the outside (Pe) of the tubules (∆P) and is counterbalanced by lower wall tension by a factor depending on the radius. The latter is a function of tubule length. In adult dominant polycystic kidney disease (ADPKD), a minimal reduction in the wall tension may lead to a dilatation in the tubular segments along the nephron over the years. The initial increase in the tubule radius would then facilitate the progressive expansion of the cysts. In this regard, tubular cell proliferation may be, at least partially, a consequence of the progressive cysts' expansion. This theory is discussed in view of other diseases with reduced wall tension and with cysts and the therapeutic effects of vaptans, somatostatin, SGLT2 inhibitors, and potentially other therapeutic targets.

Cardiovascular Outcomes in Kidney Transplant Recipients With ADPKD

Introduction

Cardiovascular disease leads to high morbidity and mortality in patients with kidney failure. Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a systemic disease with various cardiac abnormalities. Details on the cardiovascular profile of patients with ADPKD who are undergoing kidney transplantation (KT) and its progression are limited.

Methods

Echocardiographic data within 2 years before KT (1993-2020), and major adverse cardiovascular events (MACEs) after transplantation were retrieved. The primary outcome is to assess cardiovascular abnormalities on echocardiography at the time of transplantation in ADPKD as compared with patients without ADPKD matched by sex (male, 59.4%) and age at transplantation (57.2 ± 8.8 years).

Results

Compared with diabetic nephropathy (DN, n = 271) and nondiabetic, patients without ADPKD (NDNA) (n = 271) at the time of KT, patients with ADPKD (n = 271) had lower rates of left ventricular hypertrophy (LVH) (39.4% vs. 66.4% vs. 48.6%), mitral (2.7% vs. 6.3% vs. 7.45) and tricuspid regurgitations (1.8% vs. 6.6% vs. 7.2%). Patients with ADPKD had less diastolic (25.3%) and systolic (5.6%) dysfunction at time of transplantation. Patients with ADPKD had the most favorable post-transplantation survival (median 18.7 years vs. 12.0 for diabetic nephropathy [DN] and 13.8 years for nondiabetic non-ADPKD [NDNA]; P < 0.01) and the most favorable MACE-free survival rate (hazard ratio = 0.51, P < 0.001). Patients with ADPKD had worsening of their valvular function and an increase in the sinus of Valsalva diameter post-transplantation (38.2 vs. 39.9 mm, P < 0.01).

Conclusion

ADPKD transplant recipients have the most favorable cardiac profile pretransplantation with better patient survival and MACE-free survival rates but worsening valvular function and increasing sinus of Valsalva diameter, as compared with patients with other kidney diseases.

Endovascular repair of abdominal aortic or iliac artery pathologies in patients with autosomal dominant polycystic kidney disease

BACKGROUND

This study aims to evaluate the efficacy and safety of endovascular aneurysm repair (EVAR) of abdominal aortic or iliac artery pathologies in patients with autosomal dominant polycystic kidney disease (ADPKD).

METHODS

From January 2014 to December 2019, fifteen consecutive patients (13 men, mean age 69.3 years, range 56-82 years) with abdominal aortic or iliac artery pathologies coexisting with ADPKD underwent EVAR in our department. Their general data, perioperative results and follow-up outcomes were retrospectively reviewed and analyzed. RESULTS：Among the fifteen patients, eleven had abdominal aortic aneurysms, one had isolated abdominal aortic dissection and the other three had iliac artery aneurysms. Three patients had thoracic penetrating aortic ulcer and two had intracranial aneurysms as the comorbidities. All patients underwent EVAR with the aorto-iliac pathologies successfully excluded. The average operative time was 171±73 minutes and average contrast volume was 87±12mL. The average follow-up time was 38.4 months (range 6-60). Aorta-bi-iliac stent-grafts were deployed in fourteen patients, while one patient received tubular stent-graft. Two patients underwent simultaneous TEVAR and EVAR, and One underwent EVAR 3 months after TEVAR. One patient was found to have a hematoma at the site of femoral access 3 days after EVAR. One patient was found to have a Type Ib endoleak 5 months after EVAR, and he recovered well with a secondary endovascular intervention. Contrast-induced nephropathy was observed in two patients (13%) post EVAR. Another patient developed renal failure 20 months after EVAR, and was treated with regular hemodialysis. All other patients did not have any reported significant deterioration of renal function during follow-up. No other adverse events, such as death, paraplegia, aneurysm rupture, or open surgery conversion occurred during operation and follow-up.

CONCLUSIONS

For patients with abdominal aortic or iliac artery diseases coexisting with ADPKD, EVAR had satisfactory mid-term outcomes, without significantly exacerbating the decline of renal function. However, patients with ADPKD might have multiple vascular lesions, especially intracranial aneurysms, which should be paid enough attention in clinical practice.

[Cardiovascular disorders in autosomal dominant polycystic kidney disease]

Autosomal dominant polycystic kidney disease is the most frequent genetic kidney disease. Cardiovascular disorders associated with autosomal dominant polycystic kidney disease are multiple and may occur early in life. In autosomal dominant polycystic kidney disease cardiovascular morbidity and mortality are related both to the nonspecific consequences of chronic kidney disease and to the particular phenotype of autosomal dominant polycystic kidney disease. Compared to the general population, patients with autosomal dominant polycystic kidney disease present an increased prevalence of hypertension, left ventricular hypertrophy, atrial fibrillation, valvular diseases, aneurisms and arterial dissections. This review article provides an update on cardiovascular disorders associated with autosomal dominant polycystic kidney disease and recent pathophysiological developments.

Prevalence of Inferior Vena Cava Compression in ADPKD

Introduction

Kidney and liver cysts in autosomal dominant polycystic kidney disease (ADPKD) can compress the inferior vena cava (IVC), but IVC compression prevalence and its risk factors are unknown.

Methods

Patients who have ADPKD (n = 216) with abdominal magnetic resonance imaging (MRI) studies and age-/sex-matched controls (n = 216) were evaluated for IVC compression as well as azygous vein diameter (a marker of collateral blood flow) and IVC aspect ratio (left-to-right dimension divided by anterior-to-posterior dimension with a value of 1 corresponding to a circular (high pressure) IVC caudal to compression.

Results

Severe IVC compression (≥70%) was observed in 33 (15%) ADPKD subjects and mild compression (≥50% to <70%) was observed in 33 (15%) subjects; whereas controls had no IVC compression (P < 0.001). Severe IVC compression was associated with larger azygous vein (4.0 ± 1.3 mm versus 2.3 ± 0.8 mm without IVC compression; P < 0.001) and a more circular IVC cross-section upstream (mean IVC aspect ratio: 1.16 ± 0.27 vs. 1.69 ± 0.67, P < 0.001), suggesting higher pressure upstream from the compression. IVC compression was associated with older age, lower estimated glomerular filtration rate (eGFR), greater height-adjusted total kidney volumes, greater height-adjusted liver volume (ht-LV), and greater liver and renal cyst fractions (P < 0.001). No subject younger than 30 years had IVC compression, but ADPKD subjects ≥40 years old had 12-fold higher risk of IVC compression (95% confidence interval [CI]: 4.2–42.4), with highest predicted probability for Mayo Clinic classes 1D (59%; 95% CI: 39%–76%) and 1E (74%; 95% CI: 49%–90%) after adjustment (P < 0.001). Women with ht-LV ≥ 2000 ml/m had 83% (95% CI: 59%–95%) prevalence of IVC compression. Complications of IVC compression included deep vein thrombosis (DVT) and symptomatic hypotension.

Conclusions

IVC compression is common in ADPKD patients >40 years old, with Mayo Clinic class 1D/E, and in females with ht-LV > 2000 ml/m.

Novel non-cystic features of polycystic kidney disease: having new eyes or seeking new landscapes

For decades, researchers have been trying to decipher the complex pathophysiology of autosomal dominant polycystic kidney disease (ADPKD). So far these efforts have led to clinical trials with different candidate treatments, with tolvaptan being the only molecule that has gained approval for this indication. As end-stage kidney disease due to ADPKD has a substantial impact on health expenditures worldwide, it is likely that new drugs targeting kidney function will be developed. On the other hand, recent clinical observations and experimental data, including PKD knockout models in various cell types, have revealed unexpected involvement of many other organs and cell systems of variable severity. These novel non-cystic features, some of which, such as lymphopenia and an increased risk to develop infections, should be validated or further explored and might open new avenues for better risk stratification and a more tailored approach. New insights into the aberrant pathways involved with abnormal expression of PKD gene products polycystin-1 and -2 could, for instance, lead to a more directed approach towards early-onset endothelial dysfunction and subsequent cardiovascular disease. Furthermore, a better understanding of cellular pathways in PKD that can explain the propensity to develop certain types of cancer can guide post-transplant immunosuppressive and prophylactic strategies. In the following review article we will systematically discuss recently discovered non-cystic features of PKD and not well-established characteristics. Overall, this knowledge could enable us to improve the outcome of PKD patients apart from ongoing efforts to slow down cyst growth and attenuate kidney function decline.

Diagnostic approach and management of genetic aortopathies

Aortic aneurysms were the primary cause of nearly 10,000 deaths in 2014 according to data from the Centers for Disease Control and may involve segments of the thoracic or abdominal aorta. Thoracic aortic aneurysms and dissections are more commonly associated with an underlying genetic etiology. In the past several decades, in parallel with the burst of new genome sequencing technologies, a number of genetic aortopathies have been identified. These have provided important insights into the molecular mechanisms of aneurysmal disease, but pose challenges in clinical practice as there are limited consensus recommendations at this time. In this review, we aim to address the pathophysiology, clinical presentation, and treatment considerations in the key heritable thoracic aortopathies.