Presence of simple renal cysts is associated with increased risk of aortic dissection: a common manifestation of connective tissue degeneration?

Association of simple renal cysts to aneurysm sac shrinkage in true thoracic aortic aneurysms after thoracic endovascular aortic repair

BACKGROUND

An increased prevalence of thoracic aortic aneurysms (TAA) has been demonstrated in patients with simple renal cysts (SRC); patients with SRC have a less elastic aortic wall than those without SRC. The purpose of this study was to evaluate aneurysm sac shrinkage after thoracic endovascular aortic repair (TEVAR) for true TAA in patients with and without SRC.

METHODS

One hundred three patients with true aneurysms of the thoracic aorta who underwent TEVAR at our university hospital from November 2013 to December 2021 were included in this study. Aneurysm sac size was compared between that on baseline preoperative computed tomography and that on postoperative computed tomography scans at 1 year. A change in aneurysm sac size ≥5 mm was considered to be significant, whether due to expansion or shrinkage.

RESULTS

The patients were divided into two groups: those with SRC (46 patients [45%]) and those without SRC (57 patients [55%]). At 1 year, there was a significant difference in the proportion of aneurysm sac shrinkage between patients with SRC and those without SRC (23.9% vs 59.6%; P < .001). Patients with SRC showed significantly less aneurysm sac shrinkage than those without SRC (-1.8 ± 5.6 mm vs -5.1 ± 6.6 mm; P = .009). Univariable and multivariable analyses showed that the initial sac diameter (odds ratio, 1.08; 95% confidence interval, 1.03-1.14; P = .002) and the presence of SRC (odds ratio, 0.15; 95% confidence interval, 0.06-0.40; P < .001) were positively and negatively associated with aneurysm sac shrinkage after TEVAR, respectively.

CONCLUSIONS

The presence of a SRC was independently associated with failure of aneurysm sac shrinkage after TEVAR for true TAA. This suggests that the presence of a SRC may be a predictor for the failure of aneurysm sac shrinkage after TEVAR.

The Correlation and Copathogenesis of Coronary Aortic Sandwich and Renal Cysts

Objective

To determine the correlation for aortic occlusion and hydronephrosis and the pathogenesis of copathogenesis.

Methods

A retrospective census was established to probe the correlation with renal cysts by gathering aortic coarctation details concerning generic symptoms, diabetes, and liver and kidney profiles from 244 hospitalized aortic clinographers from April 2014 to December 2021 (study category, SG category), 150 hypertensive clients with primary hypertension attending our institution in the same period (matched category, MG category), and 150 able-bodied volunteers (control category, CG category).

Results

(1) Intercategory discrepancies in regard to aortic occlusion, diabetic malfunction, and kidney and liver abnormality were neither mutually nor predominantly measured (P > 0.05); (2) 244 enrolled SG for aortic occlusion and 150 CG for aortic occlusion were categorized by whether or not aortic occlusion was manifested, and the correlation between maternal age, gender, diabetic malfunction, and kidney and liver abnormality and renal cysts was estimated. The correlation of clogged aorta was demonstrated by a multifactorial logistic regression with gender and the presence of renal cysts (P < 0.05); (3) the correlation of clogged aorta was demonstrated by a multifactorial logistic regression with renal cysts as an independent risk factor for clogged aorta (95% CI: 1.028–10.291;P = 0.031).

Conclusion

As renal cysts are an autonomous risk of aortic coarctation, it is recommendable to strengthen clinical investigations such as monitoring of clinical blood pressures in kidney cyst recipients to assess their aortic function in order to evaluate their prognosis and minimize the prevalence of aortic coarctation.

Association of preoperative pulse wave velocity to aneurysm sac shrinkage after endovascular aneurysm repair

BACKGROUND

Arterial stiffness may be the underlying cause of the divergent sac behavior after endovascular aortic repair (EVAR). We evaluated arterial stiffness using pulse wave velocity (PWV) in patients undergoing EVAR for abdominal aortic aneurysm (AAA) and demonstrated that arterial stiffness is a predictor for determining sac behavior after EVAR.

METHODS AND RESULTS

One hundred nineteen patients with infrarenal AAA undergoing EVAR between November 2013 and July 2019 were included in this study. Preoperative brachial-ankle PWV was measured using an automated oscillometric method at our vascular laboratory. PWV and other risk factors were assessed with respect to being a risk factor for sac shrinkage at 2 years postoperatively. Univariate and multivariable analyses revealed preoperative PWV (odds ratio [OR] 0.87; 95% confidence interval [CI] 0.79-0.98; p = 0.045) and the incidence of operative type II endoleak (OR 0.68; 95% CI 0.10-0.81; p = 0.048) as an independent risk factor for sac shrinkage at 2 year postoperatively. The receiver-operating characteristic curve analysis showed that the optimal cutoff value for predicting sac shrinkage was 17.79 m/s, and significantly predicted sac shrinkage.

CONCLUSIONS

Preoperative PWV was independently associated with sac shrinkage after EVAR, suggesting that arterial stiffness may be one of the key factors for determining sac behavior after EVAR.

3D Mapping Reveals a Complex and Transient Interstitial Matrix During Murine Kidney Development

BACKGROUND

The extracellular matrix (ECM) is a network of proteins and glycosaminoglycans that provides structural and biochemical cues to cells. In the kidney, the ECM is critical for nephrogenesis; however, the dynamics of ECM composition and how it relates to 3D structure during development is unknown.

METHODS

Using embryonic day 14.5 (E14.5), E18.5, postnatal day 3 (P3), and adult kidneys, we fractionated proteins based on differential solubilities, performed liquid chromatography-tandem mass spectrometry, and identified changes in ECM protein content (matrisome). Decellularized kidneys were stained for ECM proteins and imaged in 3D using confocal microscopy.

RESULTS

We observed an increase in interstitial ECM that connects the stromal mesenchyme to the basement membrane (TNXB, COL6A1, COL6A2, COL6A3) between the embryo and adult, and a transient elevation of interstitial matrix proteins (COL5A2, COL12A1, COL26A1, ELN, EMID1, FBN1, LTBP4, THSD4) at perinatal time points. Basement membrane proteins critical for metanephric induction (FRAS1, FREM2) were highest in abundance in the embryo, whereas proteins necessary for integrity of the glomerular basement membrane (COL4A3, COL4A4, COL4A5, LAMB2) were more abundant in the adult. 3D visualization revealed a complex interstitial matrix that dramatically changed over development, including the perinatal formation of fibrillar structures that appear to support the medullary rays.

CONCLUSION

By correlating 3D ECM spatiotemporal organization with global protein abundance, we revealed novel changes in the interstitial matrix during kidney development. This new information regarding the ECM in developing kidneys offers the potential to inform the design of regenerative scaffolds that can guide nephrogenesis in vitro.

Association of Abdominal Aortic Aneurysm and Simple Renal Cysts: A Systematic Review and Meta-Analysis

BACKGROUND-OBJECTIVE

Prior studies have suggested a higher prevalence of simple renal cysts (SRC) among patients with aortic disease, including abdominal aortic aneurysms (AAA). Thus, the aim of this study was to systematically review all currently available literature and investigate whether patients with AAA are more likely to have SRC.

METHODS

This study was performed according to the PRISMA guidelines. A meta-analysis was conducted with the use of random effects modeling and the I-square was used to assess heterogeneity. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were synthesized to compare the prevalence of several patients' characteristics between AAA vs. no-AAA cases.

RESULTS

Eleven retrospective studies, 9 comparative (AAA vs. no-AAA groups) and 3 single-arm (AAA group), were included in this meta-analysis, enrolling patients (AAA: N = 2,297 vs. no-AAA: N = 35,873) who underwent computed tomography angiography as part of screening or preoperative evaluation for reasons other than AAA. The cumulative incidence of SRC among patients with AAA and no-AAA was 55% (95% CI: 49%-61%) and 32% (95% CI: 22%-42%) respectively, with a statistically higher odds of SRC among patients with AAA (OR: 3.02; 95% CI: 2.01-4.56; P< 0.001). The difference in SRC prevalence remained statistically significant in a sensitivity analysis, after excluding the study with the largest sample size (OR: 2.71; 95% CI: 1.91-3.84; P< 0.001).

CONCLUSIONS

Our meta-analysis demonstrated a 3-fold increased prevalence of SRC in patients with AAA compared to no-AAA cases, indicating that the pathogenic processes underlying SRC and AAA could share a common pathophysiologic mechanism. Thus, patients with SRC could be considered at high risk for AAA formation, potentially warranting an earlier AAA screening.

Association of renal cyst and type A acute aortic dissection with hypertension

Background

Type A acute aortic dissection (TA-AAD) has high mortality, with 50% of patients dying before hospital admission. Hypertension is the most common comorbidity for acute aortic dissection, and effective antihypertensive therapy is still unable to predict the risk of aortic rupture at the medium- and long-term stages. While the presence of renal cyst has been found to increases the risk of thoracic aortic disease, the correlation between renal cyst and TA-AAD with hypertension remains poorly understood. Thus, this study aimed to determine the relationship of renal cyst and TA-AAD with hypertension.

Methods

A retrospective analysis was performed in 464 hypertension patients from August 2014 to August 2019. A total of 230 TA-AAD patients were enrolled in the AD with hypertension group (age 53.79±11.31 years, male 90.87%), and matched by age, sex, and hypertension control to 234 patients without TA-AAD who were enrolled in the non-AD with hypertension group. Patients were divided into three subgroups according to the numbers of renal cysts: no renal cyst, single renal cyst, and multiple renal cysts.

Results

In this study, the AD with hypertension group had significantly more single renal cyst and multiple renal cyst cases than did the non-AD with hypertension group. The mean age of the multiple renal cyst subgroup was significantly older than that of the single renal cyst subgroup (57.25±13.00 vs. 51.57±10.75 years) in the AD with hypertension group. There was significantly different distribution of dissection starting points and dissection ending points across three renal cyst subgroups. Multivariate logistic regression analysis indicated that having no renal cyst significantly decreased the risk of TA-AAD in middle-aged and elderly patents, but showed no correlations with those of younger ages. Single renal cyst status also significantly decreased the risk of TA-AAD in elderly patients [odds ratio (OR) =0.129, 95% confidence interval (CI): 0.029–0.575, P=0.007].

Conclusions

Renal cyst status correlates with the risk of TA-AAD with hypertension in middle-aged and elderly patients, and exhibits different degrees of vascular lesion in aortic dissection. We therefore suggest that different antihypertensive standards should be adopted in different renal cyst status to more effectively prevent aortic dissection.

The association between simple renal cyst and aortic diseases: A systematic review and meta-analysis of observational studies

OBJECTIVE

The objective of this meta-analysis of observational studies was to evaluate the association between simple renal cysts (SRC) and presence of aortic pathology such as aortic aneurysms and dissection.

METHODS

We conducted searches in Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials from January 1960 to August 2019 to identify observational studies that examined the association between SRCs and any aortic diseases, including aortic aneurysms and dissection. Two reviewers independently extracted the data and assessed the risk of bias. The meta-analysis was performed by STATA 14.1.

RESULTS

In total, 11 observational studies with 19 719 participants were included in this meta-analysis. Compared to individuals without SRCs, patients with SRCs had higher odds of abdominal aortic aneurysm (AAA) (adjusted OR = 2.61, 95% CI 2.34-2.91, P < 0.001, I²   = 0%), ascending thoracic aortic aneurysm (TAA) (adjusted OR = 1.98, 95% CI 1.09-3.63, P = 0.03, I²   = 90.1%), descending TAA (adjusted OR = 3.44, 95% CI, 2.67-4.43, P < 0.001, I²   = 0%), type A aortic dissection (AD) (adjusted OR = 1.98, 95% CI 1.32-2.96, P = 0.001, I²   = 12.9%), and type B AD (adjusted OR = 2.55, 95% CI, 1.31-4.96, P = 0.006, I²   = 76.2%). There was a higher average in the sum of diameter of SRCs among AAA compared to patients without AAA (WMD = 19.80 mm, 95% CI 13.92-25.67, P < 0.001, I²   = 63.8%).

CONCLUSION

SRC is associated with higher odds of aortic diseases including AAA, ascending and descending TAA, type A and type B dissection even after adjusting for confounders.

Simple Renal Cysts Are Associated With 24-Month Prognosis of Patients With Type B Aortic Dissection and Hypertension

BACKGROUND

The association of simple renal cyst (SRC) with type B aortic dissection (BAD) has recently been established. However, no studies have examined adverse events after BAD hospitalization among patients with SRC. In this study, we assessed the prognostic value of SRC in BAD patients with hypertension after thoracic endovascular aortic repair (TEVAR).

METHODS

We studied all BAD patients with hypertension who were admitted for TEVAR (n = 238; age 56.1 ± 9.8 years, 84.0% male). Aortic-related adverse events (ARAE) were evaluated as outcomes at 3 months and 24 months after TEVAR.

RESULTS

Among the total number of patients, 104 (43.7%) had at least 1 SRC. Patients with SRC were significantly older than those without (59.6 ± 8.8 vs 53.3 ± 9.7; P < 0.001). Patients with SRC were also more likely to suffer from peripheral arterial disease (55.8% vs 40.3%; P = 0.018) and cerebrovascular accidents (47.1% vs 29.9%; P = 0.006) than those without. Median follow-up for the 238 patients was 18.5 (range 6.4-24.0) months. Cumulative ARAE-free rates were 94.5 ± 1.5% at the 3-month follow-up and 81.5 ± 2.8% at the 24-month follow-up. Independent predictors of 3-month ARAE were found to be insertion of ≥ 2 stents (hazard ratio [HR] 3.977, 95% confidence interval [CI] 1.224-12.920; P = 0.022). For 24-month follow-up, SRC (HR 1.962, 95% CI 1.023-3.764; P = 0.043) was evaluated as the only independent predictive factor. SRC (HR 8.841, 95% CI 1.726-45.294; P = 0.009) was also evaluated as an independent predictive factor for 24-month ARAEs in the chronic group, but not in the acute or the subacute group.

CONCLUSIONS

SRC could predict 24-month ARAE in BAD patients with hypertension after TEVAR, especially in the chronic group.

Aortic root and ascending aorta dimensions in acute aortic dissection

Objectives:

Aim of this study was to evaluate ascending aorta and aortic root dimension at acute type A dissection (acute aortic dissection) and to identify demographics elements being allied to the acute event.

Methods:

In a period between 2009 and 2017, 225 (n = 71, 32% female, mean age = 63 ± 12 years) patients eligible for analysis of ascending aorta and 223 (n = 70, 31% female, mean age = 63 ± 13 years) of aortic root were included in this study. Aortic diameter was assessed in preoperative computed tomography scan. The predissection diameters were modeled from the diameters obtained at diagnosis, assuming 30% augmentation of the diameter at acute event.

Results:

The mean diameter of the ascending aorta at dissection was 46 ± 8 mm and the modeled diameter was 32.3 ± 5.7 mm. The diameter of the aortic root at dissection was 42 ± 8 mm and modeled diameter was 29.5 ± 5.6 mm. In multivariate analysis, female gender (p = 0.026) and history of cerebrovascular event (p = 0.001) were associated with acute aortic dissection in small aortic root. Patient age (p < 0.001) and history of inguinal hernia (p = 0.001) in ascending aorta <55 mm correlated with acute aortic dissection.

Conclusion:

Modeling indicates that more than 90% of patients had aortic root and ascending aorta diameter <45 mm. It seems that the aortic diameter expansion over the 55 mm in development of acute aortic dissection is overestimated. Parameters other than aortic size were identified, which may be considered when patients at high risk for dissection were identified.

A machine learning model to classify aortic dissection patients in the early diagnosis phase

Aortic dissection is one of the most clinical-challenging and life-threatening cardiovascular diseases associated with high morbidity and mortality. Aortic dissection requires fast diagnosis and timely therapy. Any delay or misdiagnosis can cause severe consequence to aortic dissection patients with even higher mortality. To better help physicians identify the potential dissection within the scope of all misdiagnosed patients, this paper describes a method which is developed with data mining methods for aortic dissection patient classification and prediction in the phase of early diagnosis. Various machine learning algorithms were used to build the models which were all trained and tested on the patient dataset with cross validation. Among them, Bayesian Network model achieved the best performance by predicting at a precision rate of 84.55% with Area Under the Curve (AUC) value of 0.857. On this basis, the Bayesian Network model can help physicians better with early diagnosis of aortic dissection in clinical practice. Beyond this study, more data from diverse regions and the internal pathology can be crucial to further build a universal model with broader predictive power.

Simple renal cysts and bovine aortic arch: markers for aortic disease

Objective

This study aimed to assess the prevalence of thoracic aortic disease (TAD) and abdominal aortic aneurysms (AAA) among patients with simple renal cyst (SRC) and bovine aortic arch (BAA).

Methods

Through a retrospective search for patients who underwent both chest and abdominal CT imaging at our institution from 2012 to 2016, we identified patients with SRC and BAA and propensity score matched them to those without these features by age, gender and presence of hypertension, hyperlipidaemia, diabetes and chronic kidney disease.

Results

Of a total of 35 498 patients, 6366 were found to have SRC. Compared with the matched population without SRC, individuals with SRC were significantly more likely to have TAD (10.1% vs 3.9%), ascending aortic aneurysm (8.0% vs 3.2%), descending aortic aneurysm (3.3% vs 0.9%), type A aortic dissection (0.6% vs 0.2%), type B aortic dissection (1.1% vs 0.3%) and AAA (7.9% vs 3.3%). The 920 patients identified with BAA were significantly more likely to have TAD (21.8% vs 4.5%), ascending aortic aneurysm (18.4% vs 3.2%), descending aortic aneurysm (6.5% vs 2.0%), type A aortic dissection (1.4% vs 0.4%) and type B aortic dissection (2.4% vs 0.7%) than the matched population without BAA. SRC and BAA were found to be significantly associated with the presence of TAD (OR=2.57 and 7.69, respectively) and AAA (OR=2.81 and 2.56, respectively) on multivariable analysis.

Conclusions

This study establishes a substantial increased prevalence of aortic disease among patients with SRC and BAA. SRC and BAA should be considered markers for aortic aneurysm development.

Development and validation of a nomogram predicting the probability of type a aortic dissection at a diameter below 55 mm: A retrospective cohort study

INTRODUCTION

The study aims to build and validate a nomogram for estimating the probability of patients developing type A aortic dissection at a diameter less than 55 mm.

METHODS

A primary cohort of 896 patients diagnosed with acute type A aortic dissection by computed tomography angiography (CTA) were used for model development, with data collected between January 2005 and March 2012. The subjects were assigned to two groups based on ascending aorta diameter (group A<55 mm, Group B ≥ 60 mm). Univariate and multivariate logistic regression analyses were employed for the development of the prediction model. Demographic factors, as well as clinical and imaging characteristics were taken into account. The resulting nomogram was evaluated for performance traits, e.g. calibration, discrimination and clinical usefulness. After internal validation, the nomogram was further assessed in a different cohort containing 385 consecutive subjects examined between January 2013 and December 2015.

RESULTS

The individualized prediction nomogram included 9 predictors derived from univariate and multivariable analyses, including gender, age, weight, hypertension, liver cyst, renal cyst, bicuspid aortic valve, and bovine arch. Those predictors were double confirmed with Lasso regression. Internal validation showed good discrimination of the model with area under the curve (AUC) of 0.854 and good calibration (Hosmer-Lemeshow test, P = 0.876). Application of the nomogram in the validation cohort still revealed good discrimination (AUC = 0.802) and good calibration (Hosmer-Lemeshow test, P = 0.398). Decision curve analysis demonstrated that the prediction nomogram was clinically useful.

CONCLUSIONS

The current work presents a prediction nomogram incorporating demographical data as well as clinical and imaging characteristics that could help identify patients who might develop type A aortic dissection at a diameter less than 55 mm with convenience.

Increased risk of kidney damage among Chinese adults with simple renal cyst

BACKGROUND

The presence of simple renal cyst (SRC) has been related to hypertension, the early and long-term allograft function, and aortic disease, but the relationship with kidney damage was still controversial. Accordingly, we conducted a large sample cross-sectional study to explore the association of SRC with indicators of kidney damage among Chinese adults.

METHODS

A total of 42,369 adults (aged 45.8 ± 13.67 years, 70.6% males) who visited the Health Checkup Clinic were consecutively enrolled. SRC was assessed by ultrasonography according to Bosniak category. Multiple regression models were applied to explore the relationships between SRC and indicators of kidney damage [proteinuria (dipstick urine protein ≥ 1+) and decreased estimated glomerular filtration rate (DeGFR) < 60 ml/min/1.73 m²].

RESULTS

Among all participants in the study, the prevalence of SRC was 10.5%. As a categorical outcome, participants with more 1 cyst and with 1 cyst had higher percentage of proteinuria [53 (5.3%) and 93 (2.7%) vs. 596 (1.6%), p < 0.001] and DeGFR [57 (5.7%) and 85 (2.5%) vs. 278 (0.7%), p < 0.001] compared with participants with no cyst. SRC significantly correlated with proteinuria [OR 1.59 (95% CI 1.30-1.95)] and DeGFR [OR 1.97 (95% CI 1.56-2.47)] after adjusting for potential confounders. Furthermore, the results also demonstrated that maximum diameter (per 1 cm increase), bilateral location, and multiple cysts significantly correlated with DeGFR in the multiple logistic regression analysis.

CONCLUSIONS

The study revealed that SRC significantly correlated with kidney damage and special attention should be paid among Chinese adults with SRC.

Guilt by association: a paradigm for detection of silent aortic disease

Detection of clinically silent thoracic aortic aneurysm (TAA) is challenging due to the lack of symptoms (until aortic rupture or dissection occurs). A large proportion of TAA are identified incidentally while imaging a patient for other reasons. However, recently several clinical "associates" of TAA have been described that can aid in identification of silent TAA. These "associates" include intracranial aneurysm, aortic arch anomalies, abdominal aortic aneurysm (AAA), simple renal cysts (SRC), bicuspid aortic valve, temporal arteritis, a positive family history of aneurysm disease, and a positive thumb-palm sign. In this article we examine these associates of TAA and the data supporting their involvement with asymptomatic TAA.

Simple Renal Cysts as Markers of Thoracic Aortic Disease

Background

Thoracic aortic aneurysm is usually a clinically silent disease; timely detection is largely dependent upon identification of clinical markers of thoracic aortic disease (TAD); (bicuspid aortic valve, intracranial aortic aneurysm, bovine aortic arch, or positive family history). Recently, an association of simple renal cysts (SRC) with abdominal aortic aneurysm and aortic dissection was established. The aim of our study was to evaluate the prevalence of SRC in patients with TAD in order to assess whether the presence of SRC can be used as a predictor of TAD.

Methods and Results

We evaluated the prevalence of SRC in 842 patients with TAD (64.0% males) treated at our institution from 2004 to 2013 and compared to a control group of patients (n=543; 56.2% males). Patients were divided into 4 groups: ascending aortic aneurysm (456; 54.2%); descending aortic aneurysm (86; 10.2%); type A aortic dissection (118; 14.0%); and type B aortic dissection (182; 21.6%). SRC were identified by abdominal computed tomography or magnetic resonance imaging of these patients. Prevalence of SRC is 37.5%, 57.0%, 44.1%, and 47.3% for patients with ascending aneurysm, descending aneurysm, type A dissection, and type B dissection, respectively. Prevalence of SRC in the control group was 15.3%. Prevalence of SRC was not significantly different between male and female aortic disease patients, despite reported general male predominance (2:1), which was also observed in our control group (1.7:1).

Conclusions

This study establishes an increased prevalence of SRC in patients with TAD. SRC can potentially be used as a marker for timely detection of patients at risk of TAD.

Paradigm for Detecting Silent Thoracic Aneurysm Disease

Thoracic aortic aneurysms (TAA) pose a serious detection challenge owing to their clinically silent nature. Only a small fraction of TAAs cause symptoms in patients. However, the mortality burden of this disease in the population is significant, given the high lethality of such complications as aortic rupture and dissection. Widespread screening for TAA has not been shown to be cost-effective. Therefore, currently most patients with a TAA are identified incidentally during an imaging study conducted for other reasons. Once a TAA diagnosis is established, prophylactic surgical treatment can safely be performed for aneurysms of the ascending aorta, aortic arch, and descending or thoracoabdominal aorta, thus preventing aneurysm-related death. To facilitate early detection of TAA, recent studies have identified several "associates" of TAA that may be useful in making a timely diagnosis. These "associates" include intracranial aneurysm, aortic arch anomalies, abdominal aortic aneurysm, simple renal cysts, bicuspid aortic valve, temporal arteritis, a positive family history of aneurysm disease, and a positive thumb-palm sign, among others. Although for many of these "associates" the underlying mechanism that would explain the association remains to be elucidated, the clinical correlation is strong enough to suggest screening patients with these findings for TAA. This article introduces the "Guilt by Association" paradigm for detection of silent thoracic aortic disease based on detection of clinical markers associated with this condition.

Presence of Renal Simple Cysts Is Associated With Increased Risk of Abdominal Aortic Aneurysms

We compared the incidence of renal simple cysts in 271 patients with abdominal aortic aneurysm (AAA) and 1387 patients without AAA (controls) using computed tomography (CT) angiography and abdominal CT, as a health screening program. The AAA group had significantly higher prevalence of renal simple cysts (55% vs 19%, P = .001) and chronic obstructive pulmonary disease (COPD; 12% vs 1%, P = .011) than the controls. After propensity score matching (n = 164), the prevalence of renal simple cysts was still significantly higher in the AAA group. In multivariate analysis, independent predictors of AAA were age, male gender, smoking history, hypertension, high-sensitivity C-reactive protein, creatinine, COPD, and renal simple cysts. The structural weakness predisposing for renal simple cysts may be associated with the initiation of AAA formation. More studies are needed to determine whether the presence of renal simple cysts can be considered as a risk factor for AAA.

Correlation between number of renal cysts and aortic circumferences measured using autopsy material

Although the presence of renal cysts has been reported to be associated with aortic aneurysm or dissection by imaging studies, an autopsy study has not been performed. Therefore, in our institute, recent consecutive adult autopsy cases (n=108, 64 males and 44 females) were reviewed. The circumferences and atherosclerosis ratios of both thoracic and abdominal aorta were individually measured and graded. The number of renal cysts was scored and graded. Age of subjects along with histories of smoking, hypertension, and diabetes mellitus were confirmed. Multiple linear regression analyses demonstrated that severity of atherosclerosis and the number of renal cysts were correlated with thoracic aortic circumference, while only the number of renal cysts was correlated with abdominal aortic circumference (p<0.05), which was more predominant in female subjects (p<0.05). Microscopically, significantly more dilated renal tubules (by Student's t-test, p<0.05) along with decreased stainability of basement membrane by Periodic acid-Schiff staining and immunostaining of type IV collagen were noted in background renal tissues in cases with numerous renal cysts than in age- and sex-matched controls without renal cysts (n=10 vs. 10). The present study suggests that a syndrome that affects both aorta and renal tubules may exist.

Cysts and swellings: a systematic review of the association between polycystic kidney disease and abdominal aortic aneurysm

BACKGROUND

Whether abdominal aortic aneurysm (AAA) forms part of the extrarenal manifestations of autosomal-dominant polycystic kidney disease (ADPKD) is unclear. We set out to review the evidence for an association.

MATERIALS AND METHODS

PubMed, Medline, Embase, and Web of Science databases 1960-2011 were searched [abdominal aortic aneurysm OR AAA OR triple A] AND [polycystic kidney disease OR PKD OR ADPKD OR Renal Cysts]. No limitations were placed on article type or language. Reference lists were recursively searched as were pertinent journal contents.

RESULTS

Eighteen papers were included. Since the first documented case of ADPKD and AAA in 1980, there have been 23 case reports. The voluminous kidneys make AAA diagnosis challenging and surgical exposure difficult. Two studies have assessed aortic diameter in patients with ADPKD and controls, one finding increased aortic diameter in ADPKD (2.7 cm vs. 2.3 cm, P < 0.02) and the other finding no difference. A further study identified a higher incidence of renal cysts in patients with AAA compared to controls (54% vs. 30%, P = 0.0006).

CONCLUSION

There is not enough clinical evidence to determine if ADPKD and AAA share a common pathology. Larger multicenter trials are required to determine if a link exists.