Multi-detector computed tomography in the diagnosis and management of acute aortic syndromes

Association Between IV Contrast Media Exposure and Acute Kidney Injury in Patients Requiring Emergency Admission: A Nationwide Observational Study in Japan

OBJECTIVE

This study aimed to elucidate the association between IV contrast media CT and acute kidney injury (AKI) and in-hospital mortality among patients requiring emergency admission.

DESIGN

In this retrospective observational study, we examined AKI within 48 hours after CT, renal replacement therapy (RRT) dependence at discharge, and in-hospital mortality in patients undergoing contrast-enhanced CT or nonenhanced CT. We performed 1:1 propensity score matching to adjust for confounders in the association between IV contrast media use and outcomes. Subgroup analyses were performed according to age, sex, diagnosis at admission, ICU admission, and preexisting chronic kidney disease (CKD).

SETTING AND PATIENTS

This study used the Medical Data Vision database between 2008 and 2019. This database is Japan's largest commercially available hospital-based claims database, covering about 45% of acute-care hospitals in Japan, and it also records laboratory results.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The study included 144,149 patients with (49,057) and without (95,092) contrast media exposure, from which 43,367 propensity score-matched pairs were generated. Between the propensity score-matched groups of overall patients, exposure to contrast media showed no significant risk of AKI (4.6% vs. 5.1%; odds ratio [OR], 0.899; 95% CI, 0.845-0.958) or significant risk of RRT dependence (0.6% vs. 0.4%; OR, 1.297; 95% CI, 1.070-1.574) and significant benefit for in-hospital mortality (5.4% vs. 6.5%; OR, 0.821; 95% CI, 0.775-0.869). In subgroup analyses regarding preexisting CKD, exposure to contrast media was a significant risk for AKI in patients with CKD but not in those without CKD.

CONCLUSIONS

In this large-scale observational study, IV contrast media was not associated with an increased risk of AKI but concurrently showed beneficial effects on in-hospital mortality among patients requiring emergency admission.

Recognition and initial management of acute aortic dissection

Acute aortic dissection is a cardiovascular emergency that should be recognised on presentation in the Emergency Department (ED) because clinical outcome is time-dependent. In suspected cases of acute aortic dissection, immediate imaging with chest computed tomography scan followed by transthoracic echocardiography (TTE) is essential to confirm diagnosis. Immediate medical management is aimed at controlling the heart rate (60-80 beats/min), systolic blood pressure (100-120 mmHg) and pain. Patients with Type A acute aortic dissection should immediately be referred to the cardiothoracic surgeons for emergency aortic surgery while those with Type B acute aortic dissection should be referred to the vascular surgeons for surgical/endovascular interventions if indicated.

[Diagnostics and treatment of traumatic aortic injuries]

Hintergrund

Traumatische Aortenverletzungen (TAV) sind seltene Folgen von stumpfen Traumata, die eine hohe Mortalität und Morbidität aufweisen. Die schnelle und akkurate Diagnostik sowie die Wahl der korrekten Therapie sind für das Patientenüberleben elementar.

Fragestellung

Bestimmung des aktuellen Standards der Abklärung von TAV im akuten Trauma-Setting und Evaluation der aktuellen Leitlinien zur Therapie.

Material und Methode

Eine Literaturrecherche wurde durchgeführt, mit der Suche nach Publikationen, die die Abklärung und Diagnostik der TAV beschreiben. Außerdem wurden Leitlinien für die Behandlung und Nachsorge von TAV zusammengefasst.

Ergebnisse

In der Literatur wird trotz geringer Spezifität eine konventionelle Thoraxröntgenaufnahme als Initialdiagnostik genannt. Es sollte primär, als Modalität der Wahl, zur Diagnostik und zur Therapiestratifizierung eine Computertomographie (CT) aufgrund der hohen Sensitivität und Spezifität nachfolgen. In allen Leitlinien ist die thorakale endovaskuläre Aortenrekonstruktion („thoracic endovascular aortic repair“, TEVAR) die Therapie der Wahl bei höhergradigen TAV (Grade II–IV) und hat die offene Chirurgie in dem meisten Fällen abgelöst.

Schlussfolgerung

Nach einer kurzfristig erfolgten CT-Diagnostik und Einteilung wird die TEVAR der offenen Chirurgie bei therapiebedürftigen TAV vorgezogen.

Multidetector Computed Tomography in Traumatic and Nontraumatic Aortic Emergencies: Emphasis on Acute Aortic Syndromes

Aortic emergencies comprise of a list of conditions which are uncommon but are potentially fatal. Prognosis is usually determined by emergent diagnosis and treatment and hence radiology plays a key role in patient management. In this article, we aim to review the various causes of aortic emergencies and the relevant imaging findings placing special emphasis on acute aortic syndromes.

Significance of an additional unenhanced scan in computed tomography angiography of patients with suspected acute aortic syndrome

AIM

To assess potential benefits of an additional unenhanced acquisition in computed tomography angiography (CTA) in patients with suspected acute aortic syndrome (AAS).

METHODS

A total of 103 aortic CTA (non-electrocardiography-gated, 128 slices) performed due to suspected AAS were retrospectively evaluated for acute aortic dissection (AAD), intramural hematoma (IMH), or penetrating aortic ulcer (PAU). Spiral CTA protocol consisted of an unenhanced acquisition and an arterial phase. If AAS was detected, a venous phase (delay, 90 s) was added. Images were evaluated for the presence and extent of AAD, IMH, PAU, and related complications. The diagnostic benefit of the unenhanced acquisition was evaluated concerning detection of IMH.

RESULTS

Fifty-six (30% women; mean age, 67 years; median, 68 years) of the screened individuals had AAD or IMH. A triphasic CT scan was conducted in 76.8% (n = 43). 56% of the detected AAD were classified as Stanford type A, 44% as Stanford type B. 53.8% of the detected IMH were classified as Stanford type A, 46.2% as Stanford type B. There was no significant difference in the involvement of the ascending aorta between AAD and IMH (P = 1.0) or in the average age between AAD and IMH (P = 0.548), between Stanford type A and Stanford type B in general (P = 0.650) and between Stanford type A and Stanford type B within the entities of AAD and IMH (AAD: P = 0.785; IMH: P = 0.146). Only the unenhanced acquisitions showed a significant density difference between the adjacent lumen and the IMH (P = 0.035). Subadventitial hematoma involving the pulmonary trunk was present in 5 patients (16%) with Stanford A AAD. The difference between the median radiation exposure of a triphasic (2737 mGy*cm) compared to a biphasic CT scan (2135 mGy*cm) was not significant (P = 0.135).

CONCLUSION

IMH is a common and difficult to detect entity of AAS. An additional unenhanced acquisition within an aortic CTA protocol facilitates the detection of IMH.

Multislice spiral CT angiography for evaluation of acute aortic syndrome

OBJECTIVE

To discuss the diagnostic value of multislice CT angiography (MSCTA) in acute aortic syndrome (AAS).

MATERIALS AND METHODS

The clinical and imaging data of 36 cases diagnosed as AAS by MSCTA were collected. The manifestations of the MSCTA images were reviewed retrospectively, and the average x-ray dose was calculated.

RESULTS

Among 36 AAS cases, 16 cases had aortic dissection (AD), 8 cases had penetrating atherosclerotic ulcer (PAU), 7 cases had intramural hematoma (IMH), and 5 cases had unstable thoracic aneurysm (UTA). Of 16 cases with AD, type A and type B accounted for 43.7% (7/16) and 56.3% (9/16), respectively. Of 7 cases with IMH, type A and type B accounted for 42.9% (3/7) and 57.1% (4/7), respectively.

CONCLUSION

In spite of the x-ray radiation, MSCTA proves to be a rapid and noninvasive imaging technique for the diagnosis of AAS.

Emergent Endovascular Stent Grafts for Ruptured Aortic Aneurysms

Ruptured aortic aneurysms uniformly require emergent attention. Historically, urgent surgical repair or medical management was the only treatment options. The development of covered stent grafts has introduced a third approach in the care of these critical patients. The clinical status of the patient and local physician expertise drive the treatment modalities in the majority of cases. The goal of therapy in these patients is to stabilize the patient as quickly as possible, establish maximum survival with minimum morbidity, and provide a long lasting result. The endovascular approach has become an acceptable treatment option in an increasing number of patients presenting with ruptured aneurysmal disease of both the descending thoracic and abdominal aorta. Major factors influencing treatment include patient clinical status, characteristics of the aorta, physician preference, institutional experience, and availability of appropriate equipment. Planning, experience, and the ability to improvise effective solutions are keys to the success of the procedure when endovascular techniques are utilized. Three separate cases, requiring intraprocedural improvisation, are presented followed by a review of the literature.