MDCT findings of aortic branch artery pseudoaneurysms associated with type B intramural haematoma

Prognostic Implications of Initial Focal Contrast Enhancement in Acute Type B Intramural Hematoma

BACKGROUND

The prognostic implication of initial focal contrast enhancement (FCE), including focal intimal disruption (FID) and intramural blood pool (IBP), in acute type B intramural hematoma (IMH) remain unclear.

OBJECTIVES

The purpose of this study was to compare the prognostic implications in IMH with or without FCE.

METHODS

A total of 574 patients were enrolled. FID was defined as an intimal disruption with contrast-filled out-pouching from the aorta lumen with a communicating orifice of >3 mm, and IBP was defined as a localized contrast medium-filled pool inside the IMH.

RESULTS

A total of 207 (36.1%) patients with initial FCE, including 132 (63.8%) FIDs and 75 (36.2%) IBPs, were identified. Patients with FCE accompanying IMH were more likely to have hypertension (P = 0.001), pleural effusion (P = 0.006), fewer aortic segments involved (P < 0.001), more adverse aortic events (AAEs) (P < 0.001), and fewer freedom from intervention (P = 0.002). Pleural effusion (HR: 1.79; 95% CI: 1.25-2.55; P = 0.001) and FCE (HR: 1.51; 95% CI: 1.12-2.02; P = 0.006) were identified to be the independent risk factors of AAEs. In the subgroup analysis, IMH with initial FID were more likely to progress than those with initial IBP (P < 0.001). FIDs located at the proximal descending aorta (HR: 2.95; 95% CI: 1.65-5.29; P < 0.001) were associated with AAEs.

CONCLUSIONS

Patients with FCE accompanying IMH were more likely to progress, especially in those initial FID localized at the proximal descending aorta. (Nature course and predictors of progression of intramural hematoma: A retrospective, multicenter study; ChiCTR2300073829).

Endovascular treatment of traumatic renal artery pseudoaneurysm with a Stanford type A intramural haematoma: A case report

BACKGROUND

Aortic intramural hematoma (IMH) associated with aortic branch tear and intramurally located pseudoaneurysm after blunt trauma has not been reported. Here, we report a case of progressive type A aortic IMH associated with a pseudoaneurysm arising from the injured proximal renal artery after blunt trauma.

CASE SUMMARY

During logging operations, a 66-year-old man experienced blunt force trauma after being injured by a fallen tree. He arrived at our trauma center with a left flank pain complaint. Computed tomography (CT) revealed a pseudoaneurysm arising from the proximal renal artery (localized within the aortic media) and Stanford type A IMH. A covered stent was deployed along the left main renal artery, bridging the pseudoaneurysm and covering the parent artery, successfully excluding the pseudoaneurysm as confirmed using aortography. However, although the degree of the pseudoaneurysm decreased, follow-up CT revealed remnant pseudoaneurysm, likely caused by an endoleak. Subsequently, a covered stent was additionally installed through the previously deployed covered stent. Successful exclusion of the pseudoaneurysm was confirmed using final aortography. In the 7-mo follow-up CT scan, the IMH and pseudoaneurysm completely disappeared with no evidence of stent-related complications.

CONCLUSION

Endovascular treatment such as stent-graft placement can be an effective and safe treatment for traumatic renal artery injury.

Beyond the term penetrating aortic ulcer: A morphologic descriptor covering a constellation of entities with different prognoses

Penetrating aortic ulcer (AU) is defined as localized disruption of the intimal layer of the aortic wall, resulting in a crater-like lesion outpouching from the vessel contour. AU is a generic term which encompasses a constellation of entities with different etiologies and prognoses and may be a complication of infective, inflammatory, traumatic, iatrogenic, atherosclerotic processes or intramural hematoma. One of the most challenging scenarios of AU for a differential diagnosis, but also for treatment implications, is when they are associated with acute aortic syndrome. Despite advances in the field of aortic disease, lack of consensus defining these lesions and the significant semantic confusion in the medical literature of the acronym PAU (for penetrating aortic ulcer but also for penetrating atherosclerotic ulcer) have given rise to controversy in guidelines and expert consensus, leading to the same treatment being recommended for entities with different etiology and prognosis. Moreover, in the medical literature, most diagnoses were mainly based on imaging techniques which identified AU regardless of clinical symptoms, surrounding imaging findings or dynamic morphologic changes. In this Review, we provide the latest insight into the differential diagnosis between AU, also called penetrating aortic ulcers, based on clinical context and the newest imaging characteristics to aid treatment decision-making.

Intramural hematoma and penetrating ulcer in the descending aorta: differences and similarities

Acute aortic syndromes include a variety of overlapping clinical and anatomic diseases. Intramural hematoma (IMH), penetrating atherosclerotic ulcer (PAU), and aortic dissection can occur as isolated processes or can be found in association. All these entities are potentially life threatening, so prompt diagnosis and treatment is of paramount importance. IMH and PAU affect patients with atherosclerotic risk factors and are located in the descending aorta in 60-70% of cases. IMH diagnosis can be correctly made in most cases. Aortic ulcer is a morphologic entity which comprises several entities-the differential diagnosis includes PAU, focal intimal disruptions (FID) in the context of IMH evolution and ulcerated atherosclerotic plaque. The pathophysiologic mechanism, evolution and prognosis differ somewhat between these entities. However, most PAU are diagnosed incidentally outside the acute phase. Persistent pain despite medical treatment, hemodynamic instability, maximum aortic diameter (MAD) >55 mm, significant periaortic hemorrhage and FID in acute phase of IMH are predictors of acute-phase mortality. In these cases, TEVAR or open surgery should be considered. In non-complicated IMH or PAU, without significant aortic enlargement, strict control of cardiovascular risk factors and frequent follow-up imaging appears to be a safe management strategy.

Intimal disruption in type B aortic intramural hematoma. Does size matter? A systematic review and meta-analysis

BACKGROUND

Type B intramural hematoma (IMH) is considered a low-risk entity for aortic complications if aortic dilation, containing rupture or clinical instability are absent. However, the development of intimal disruptions (ID), present in >40% of cases, poses an unknown risk.

OBJECTIVES

To establish which ID characteristics imply a higher risk of aortic complications and, therefore, merit invasive treatment.

METHODS

A systematic review and a meta-analysis were made following a search in EMBASE, MEDLINE and PsycINFO for articles published between January 1995 and December 2017. The combined endpoint was defined as aortic mortality, invasive treatment for aortic disease and/or increase in maximum aortic diameter ≥55 mm. Lesions with communicating orifice ≤3 mm were defined as tiny ID (TID) and those with >3 mm as focal ID (FID).

RESULTS

Six studies with 564 participants diagnosed of type B IMH were included. Incidence of ID was 54.3% (306 individuals): 27.7% (156 individuals) initially met TID criteria; however, 13.9% of these (21 of 151 with morphologic evolution) evolved to FID within the first 6 months. Ninety-two cases suffered clinical aorta-related events (16.3%; mean follow-up range: 15-85 months; median: 52 months). Patients with TID had a similar risk of aorta-related events to those without ID (RR = 0.904; 95% CI, 0.335-2.440; P = 0.842; I² = 42.5%), but lower than those with FID (RR = 0.299; 95% CI, 0.094-0.952; P = 0.041; I² = 26.9%).

CONCLUSIONS

Tiny intimal disruption in type B IMH evolution is not related to an increased risk of complications and should not be considered an indication for invasive treatment. However, since 14% of TID evolve to FID within the first 6 months, close follow-up with imaging techniques is advisable.

MDCT evaluation of acute aortic syndrome (AAS)

Non-traumatic acute thoracic aortic syndromes (AAS) describe a spectrum of life-threatening aortic pathologies with significant implications on diagnosis, therapy and management. There is a common pathway for the various manifestations of AAS that eventually leads to a breakdown of the aortic intima and media. Improvements in biology and health policy and diffusion of technology into the community resulted in an associated decrease in mortality and morbidity related to aortic therapeutic interventions. Hybrid procedures, branched and fenestrated endografts, and percutaneous aortic valves have emerged as potent and viable alternatives to traditional surgeries. In this context, current state-of-the art multidetector CT (MDCT) is actually the gold standard in the emergency setting because of its intrinsic diagnostic value. Management of acute aortic disease has changed with the increasing realization that endovascular therapies may offer distinct advantages in these situations. This article provides a summary of AAS, focusing especially on the MDCT technique, typical and atypical findings and common pitfalls of AAS, as well as recent concepts regarding the subtypes of AAS, consisting of aortic dissection, intramural haematoma, penetrating atherosclerotic ulcer and unstable aortic aneurysm or contained aortic rupture. MDCT findings will be related to pathophysiology, timing and management options to achieve a definite and timely diagnostic and therapeutic definition. In the present article, we review the aetiology, pathophysiology, clinical presentation, outcomes and therapeutic approaches to acute aortic syndromes.

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.

Aortic branch artery pseudoaneurysms associated with intramural hematoma: when and how to do endovascular embolization

PURPOSE

To describe when and how to perform endovascular embolization of aortic branch artery pseudoaneurysms associated with type A and type B intramural hematoma (IMH) involving the descending thoracic and abdominal aorta (DeBakey I and III) that increased significantly in size during follow-up.

MATERIALS AND METHODS

Sixty-one patients (39 men; mean ± standard deviation age 66.1 ± 11.2 years) with acute IMH undergoing at least two multidetector computed tomographic examinations during follow-up for 12 months or longer were enrolled. Overall, 48 patients (31 men, age 65.9 ± 11.5) had type A and type B IMH involving the descending thoracic and abdominal aorta (DeBakey I and III).

RESULTS

Among the 48 patients, 26 (54 %; 17 men, aged 64.3 ± 11.4 years) had 71 aortic branch artery pseudoaneurysms. Overall, during a mean follow-up of 22.1 ± 9.5 months (range 12-42 months), 31 (44 %) pseudoaneurysms disappeared; 22 (31 %) decreased in size; two (3 %) remained stable; and 16 (22 %) increased in size. Among the 16 pseudoaneurysms with increasing size, five of these (three intercostal arteries, one combined intercostobronchial/intercostal arteries, one renal artery), present in five symptomatic patients, had a significant increase in size (thickness >10 mm; width and length >20 mm). These five patients underwent endovascular embolization with coils and/or Amplatzer Vascular Plug. In all patients, complete thrombosis and exclusion of aortic pseudoaneurysm and relief of back pain were achieved.

CONCLUSION

Aortic branch artery pseudoaneurysms associated with type A and type B IMH involving the descending thoracic and abdominal aorta (DeBakey I and III) may be considered relatively benign lesions. However, a small number may grow in size or extend longitudinally with clinical symptoms during follow-up, and in these cases, endovascular embolization can be an effective and safe procedure.