Renal malperfusion: spontaneous renal artery dissection and with aortic dissection

Prediction of acute kidney injury after total aortic arch replacement with serum cystatin C and urine N-acetyl-β-d-glucosaminidase: A prospective observational study

BACKGROUND

Acute kidney injury (AKI) after total aortic arch replacement (TAAR) is frequent and associated with adverse outcomes, whereas its early detection remains a challenge. Serum cystatin C (sCysC) and urinary N-acetyl-β-d-glucosaminidase (uNAG) are clinically available renal biomarkers, but their combination for AKI detection requires more evidence. This study aimed to assess the discriminative abilities of these biomarkers in AKI after TAAR.

MATERIALS AND METHODS

Patients undergoing TAAR were included in this prospective observational study. The AKI prediction model was developed and internal verificated, and the significance of each variable was analyzed by random forest (RF). Finally, the best predictive critical values of sCysC and uNAG were explored by the AUC-ROC curve.

RESULTS

The AUC-ROC of the prediction model was substantially enhanced by adding sCysC and uNAG (0.909 vs 0.844, p < 0.001), and the clinical utility and risk reclassification were significantly improved. Additionally, the RF showed that sCysC and uNAG ranked first and second. The AUC-ROC for each were 0.864 and 0.802 respectively, and the cut-off values were 1.395 mg/L and 31.90 U/g Cre respectively.

CONCLUSION

The prediction model incorporating functional marker sCysC and tubular injury marker uNAG can improve the discriminative abilities of AKI after TAAR.

Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) Reporting Standards for Type B Aortic Dissections

This Society for Vascular Surgery/Society of Thoracic Surgeons (SVS/STS) document illustrates and defines the overall nomenclature associated with type B aortic dissection. The contents describe a new classification system for practical use and reporting that includes the aortic arch. Chronicity of aortic dissection is also defined along with nomenclature in patients with prior aortic repair and other aortic pathologic processes, such as intramural hematoma and penetrating atherosclerotic ulcer. Complicated vs uncomplicated dissections are clearly defined with a new high-risk grouping that will undoubtedly grow in reporting and controversy. Follow-up criteria are also discussed with nomenclature for false lumen status in addition to measurement criteria and definitions of aortic remodeling. Overall, the document provides a facile framework of language that will allow more granular discussions and reporting of aortic dissection in the future.

Diagnostic value of color Doppler sonography for spontaneous isolated superior mesenteric artery dissection

The present study aimed to evaluate the clinical significance of color Doppler sonography (CDS) in the diagnosis of spontaneous isolated superior mesenteric artery dissection (SISMAD). The ultrasonographic images of 19 patients with SISMAD confirmed by computed tomography angiography (CTA) were retrospectively analyzed and the ultrasonographic features were summarized. The paired t-test was used to statistically analyze the differences in parameters determined by CTA vs. CDS, including the minimal inner diameter (MID), cross-sectional area (CSA), diameter and area stenosis rate, and flow rate of the true lumen. Of the 19 patients, 18 (94.7%) were diagnosed with SISMAD with correct classification by CDS. There was no significant difference between CTA and CDS with regard to minimal ID, CSA, diameter stenosis and area stenosis rate, and flow rate of the true lumen (all P>0.05). CDS was indicated to be an effective imaging modality for the diagnosis of SISMAD.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

[Complicated acute type B aortic dissection-what does endovascular therapy contribute?]

BACKGROUND

Acute aortic dissection type B is a severe and life-threatening vascular emergency. Complications such as rupture and/or malperfusion of organs are the main reasons for early mortality.

OBJECTIVES

The aim is to provide an overview on important diagnostic radiological findings, conservative as well as endovascular therapeutic options for patients presenting with rupture or malperfusion syndromes.

RESULTS

Medical treatment consisting of blood pressure and heart rate control as well las adequate analgesia remains the cornerstone therapy of all type B aortic dissections. In case of organ malperfusion, various endovascular therapies, e. g., endoluminal fenestration of dissection flap, thoracic stent-graft implantation (TEVAR) or branch vessel stenting, are available. In the case of aortic rupture, TEVAR has become the standard owing to its lower mortality compared to open surgical repair.

DISCUSSION

For the treatment of complicated type B aortic dissection, a number of endovascular options are available. For optimal treatment, profound knowledge of the disease, of the diagnostic workup, and of the interventional procedures is mandatory.

Renovascular hypertension: endovascular therapy in complicated aortic Stanford type B dissection

A 63 years old male with a history of arterial hypertension presented with a current onset of chest pain and discrete headaches accompanied with dizziness. His blood pressure, 210/110 mmHg, had worsened and showed a reversed circadian rhythm with an average of 150/90 mmHg during night time. A CT angiography of the aorta demonstrated a type B dissection involving the right renal artery causing reduced perfusion of the right kidney. Subsequent invasive aortic angiography showed a continuously moving aortic dissection flap resulting in a dynamic stenosis proven by varying pressure gradients of between 5 and 35 mmHg. Stent placement of the renal artery ostium kept the vessel open and fixed the reno-aortic dissection flap in order to prevent it from progressing into the right kidney. Follow-up examinations revealed improved blood pressure control allowing for physiologic drop of blood pressure during night-time.

Clinical Outcomes of Conservative Treatment in Patients with Symptomatic Isolated Spontaneous Renal Artery Dissection and Comparison with Superior Mesenteric Artery Dissection

OBJECTIVES

The aims of this study were to report the clinical outcomes of conservative medical treatment in patients with symptomatic isolated spontaneous renal artery dissection (SRAD) and compare them with those of spontaneous superior mesenteric artery dissection (SSMAD).

METHODS

This was a single centre, observational comparative study between SRAD and SSMAD. Data from a prospective visceral artery dissection registry were analysed retrospectively. Between June 2010 and December 2016, 23 consecutive patients with symptomatic isolated SRAD who initially received conservative medical treatment were included. The primary outcomes were the aggravation of dissection requiring intervention and dissection related mortality. To evaluate the prognosis of symptomatic isolated SRAD, the clinical outcomes of isolated SRAD were compared with those of symptomatic isolated SSMAD (n = 40) during the same study period.

RESULTS

The primary outcome incidence was 39% (9/23) in patients with symptomatic isolated SRAD during the median follow up period of 20 months (range 0-63 months). The dissection related mortality rate was 17% (4/23), and the cause of death in all cases was an abrupt rupture of the dissecting aneurysm with significant true lumen stenosis. None of the patients without aneurysm or with true lumen occlusion had dissection related mortality. During the same study period, compared with the patients with symptomatic isolated SSMAD who initially received conservative medical treatment, the primary outcome incidence (39% vs. 10%, p = .009) and dissection related mortality rate (17% vs. 0%, p = .016) were statistically significantly higher in patients with symptomatic isolated SRAD.

CONCLUSIONS

Although the present analysis involved only a small number of patients, it revealed that symptomatic isolated SRAD with dissection related aneurysm and true lumen stenosis is a potentially life threatening condition and that aggressive surgical or endovascular interventions should be considered in these patients, who are refractory to conservative medical treatment.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Spontaneous dissections of multiple visceral arteries: an extremely rare case

Spontaneous dissections of visceral arteries without aortic involvement are very rare. The etiologies of these entities are unclear and their clinical managements remain controversial. We report a case of spontaneous multiple dissections affecting 4 visceral arteries including the superior mesenteric artery, the celiac artery and the bilateral renal arteries. The patient was managed conservatively and endovascularly. The clinical manifestation markedly improved and laboratory tests returned to normal limits within 1 week. The regular follow-up suggested a good clinical and radiological outcome until 84 months.