Multidetector CT findings of complications of surgical and endovascular treatment of aortic aneurysms

Usefulness of the patient-specific contrast enhancement optimizer simulation software during the whole-body computed tomography angiography

To evaluate whether the patient-specific contrast enhancement optimizer simulation software (p-COP) is useful for predicting contrast enhancement during whole-body computed tomography angiography (WBCTA). We randomly divided the patients into two groups using a random number table. We used the contrast material (CM) injection protocol selected by p-COP in group A (n = 52). The p-COP used an algorithm including data on the individual patient's cardiac output. Group B (n = 50) was assigned to the conventional CM injection protocol based on body weight. We compared the CT number in the abdominal aorta at the celiac artery level between the two groups and classified them as acceptable (> 280 HU) and unacceptable (< 279 HU) based on the optimal CT number for the WBCTA scans. To evaluate the difference in both injection protocols, we compared the visual inspection of the images of the artery of Adamkiewicz in both protocols. The CM dosage and injection rate in group A were significantly lower than those in group B (480.8 vs. 501.1 mg I/kg and 3.1 vs. 3.3 ml/s, p < 0.05). The CT number of the abdominal aorta at the celiac level was 382.4 ± 62.3 HU in group A and 363.8 ± 71.3 HU in group B (p = 0.23). CM dosage and injection rate were positively correlated to cardiac output for group A (r = 0.80, p < 0.05) and group B (r = 0.16, p < 0.05). The number of patients with an acceptable CT number was higher in group A [46/6 (86.7%)] than in group B [43/7 (71.4%)], but not significant (p = 0.71). The visualization rate for the Adamkiewicz artery was not significantly different between groups A and B (p = 0.89). The p-COP was useful for predicting contrast enhancement during WBCTA with a lower CM dosage and a lower contrast injection rate than that based on the body weight protocol. In patients with lower cardiac output a reduction in contrast injection rate and CM dosage did not lead to a reduced imaging quality, thus particularly in this group CM dosage can be reduced by p-COP.

Post-Endovascular Abdominal Aortic Aneurysm Repair Abdominal Pain: A Learning Experience

Abdominal aortic aneurysm (AAA) is one of the important pathologies involving the abdominal aorta, as it can have adverse consequences if it goes unnoticed or untreated. AAA is defined as an abnormal dilation of the abdominal aorta 3 cm or greater. Endovascular abdominal aortic aneurysm repair (EVAR) has recently emerged as a treatment modality for AAA. It does have a few inherent complications that include endoleak, endograft migration, bleeding, ischemia, and compartment syndrome. This case report discusses a patient who came in with abdominal pain and a pulsatile mass, which raised concerns regarding endoleak. The patient had a 9.9-cm AAA, which was repaired in the past, as was made evident by computed tomography findings of the stent graft in the aneurysmal segment. This case stands out because it highlights the importance of comparing the size of the AAA at the time of the EVAR to the current scenario where the patient presents with abdominal pain of unknown etiology. Also, this case report highlights the importance of computed tomography and other imaging forms in following-up with patients who have EVAR for AAAs.

Aortopulmonary fistula related death - forensic implications

A 79-year-old man with a history of arterial hypertension, insulin-dependent diabetes mellitus, renal insufficiency and thoracic endovascular aortic repair (TEVAR) was brought to the emergency department, following an episode of oliguria and urine retention. During chest X-ray he suddenly collapsed and died. Autopsy revealed a large atherosclerotic saccular thoracic aortic aneurysm whose right lateral wall firmly adhered to the right lung. There was more than 2.5 l of blood with fibrin deposits in the right part of the thoracic cavity. The right bronchus contained a cast of blood; blood was also present in the trachea and the distal airways of the right lung. Further dissection revealed that the aneurysm had eroded the tissue surrounding it and made a fistulous canal into the lower lobe of the right lung, causing the lung to fill with fluid blood. The cause of death was hemorrhage from the aortopulmonary fistula caused by pressure necrosis from the thoracic aortic aneurysm.

Aortopulmonary Fistula Presenting without an Endoleak after Thoracic Endovascular Aortic Repair

Herein, we report the case of a 60-year-old man, a smoker with a history of arterial hypertension and diabetes mellitus. After computed tomography (CT) for an episode of hemoptysis, the patient underwent elective thoracic endovascular aortic repair (TEVAR) because of a degenerative aneurysm of the descending thoracic aorta. The area of perianeurysmal pulmonary atelectasis reported on the CT scan was not considered. Three months later, he developed an aortopulmonary fistula without endoleaks. Although TEVAR is a relatively safe procedure, no detail should be overlooked in the preoperative evaluation in order to avoid life-threatening complications. Further, the effectiveness and modality of prolonged antibiotic prophylaxis and/or preoperative respiratory physiotherapy should be assessed in such cases.

MDCT distinguishing features of focal aortic projections (FAP) in acute clinical settings

Focal aortic projections (FAP) are protrusion images of the contrast medium (focal contour irregularity, breaks in the intimal contour, outward lumen bulging or localized blood-filled outpouching) projecting beyond the aortic lumen in the aortic wall and are commonly seen on multidetector computed tomography (MDCT) scans of the chest and abdomen. FAP include several common and uncommon etiologies, which can be demonstrated both in the native aorta, mainly in acute aortic syndromes, and in the post-surgical aorta or after endovascular therapy. They are also found in some types of post-traumatic injuries and in impending rupture of the aneurysms. The expanding, routine use of millimetric or submillimetric collimation of current state-of-the-art MDCT scanners (16 rows and higher) all the time allows the identification and characterization of these small ulcer-like lesions or irregularities in the entire aorta, as either an incidental or expected finding, and provides detailed three-dimensional pictures of these pathologic findings. In this pictorial review, we illustrate the possible significance of FAP and the discriminating MDCT features that help to distinguish among different types of aortic protrusions and their possible evolution. Awareness of some related and distinctive radiologic features in FAP may improve our understanding of aortic diseases, provide further insight into the pathophysiology and natural history, and guide the appropriate management of these lesions.