The microscopic features of inflammatory abdominal aortic aneurysms: discriminant analysis

Management of Inflammatory Aortic Aneurysms - A Scoping Review

OBJECTIVE

Inflammatory abdominal aortic aneurysms (InflAAAs) account for 5 - 10% of aortic aneurysms and are characterised by retroperitoneal fibrosis. Diagnosis is often delayed, and doubts remain about the optimal management strategy. This scoping review describes the current state of knowledge on InflAAAs.

METHODS

Medline, PubMed, EMBASE, and Scopus were searched for relevant studies that evaluated the diagnosis and treatment of InflAAAs. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol was followed.

RESULTS

Fifty-seven papers were selected (low level of evidence), which included 1 554 patients, who were mostly male and heavy smokers. A triad of chronic abdominal or back pain, weight loss, and elevated inflammatory markers was highly suggestive of the diagnosis but rarely present, and fever was noted only randomly. A mantle sign was seen on computed tomography angiography (CTA) in 73 - 100% of patients. Open surgical repair (OSR) and endovascular aortic aneurysm repair (EVAR) was reported in 1 376 and 178 patients, respectively. OSR was associated with significant iatrogenic bowel (n = 22), urinary tract system (n = 7), venous (n = 30), pancreatic (n = 6), and splenic (n = 5) injuries, while EVAR was associated with lower 30 day mortality (0 - 5% vs. 0 - 32%). One and two year mortality rates were similar between the two treatment modalities (0 - 20% and 0 - 36%, respectively). EVAR was more often associated with post-operative progression of inflammation (17% vs. 0.4%), and a higher frequency of persistent hydronephrosis (> 50%) and limb occlusion (20%). Used in < 10% of patients, corticosteroids led to complete pain relief and a reduction in peri-aortic inflammation within 6 - 18 months.

CONCLUSION

InflAAAs are characterised by non-specific symptoms, with the mantle sign on CTA being pathognomonic. Corticosteroids may be considered a basic treatment that all patients should receive initially. Low quality data indicate that EVAR (vs. OSR) is associated with fewer intra-operative complications and lower peri-operative mortality but more late fibrosis related adverse events. International multicentre registries are required to gather more insights into this challenging pathology.

Consensus statement on surgical pathology of the aorta from the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology: I. Inflammatory diseases

Inflammatory diseases of the aorta include routine atherosclerosis, aortitis, periaortitis, and atherosclerosis with excessive inflammatory responses, such as inflammatory atherosclerotic aneurysms. The nomenclature and histologic features of these disorders are reviewed and discussed. In addition, diagnostic criteria are provided to distinguish between these disorders in surgical pathology specimens. An initial classification scheme is provided for aortitis and periaortitis based on the pattern of the inflammatory infiltrate: granulomatous/giant cell pattern, lymphoplasmacytic pattern, mixed inflammatory pattern, and the suppurative pattern. These inflammatory patterns are discussed in relation to specific systemic diseases including giant cell arteritis, Takayasu arteritis, granulomatosis with polyangiitis (Wegener's), rheumatoid arthritis, sarcoidosis, ankylosing spondylitis, Cogan syndrome, Behçet's disease, relapsing polychondritis, syphilitic aortitis, and bacterial and fungal infections.

Surgical treatment of inflammatory abdominal aortic aneurysms: outcome and predictors analysis

OBJECTIVES

The aim of this study is to report our experience on the postoperative outcome of surgical treatment of inflammatory abdominal aortic aneurysm (IAAA).

MATERIALS AND METHODS

Between 1997-2014, 35 patients with IAAA underwent surgery. The mean age was 63+/-18years. Chronic renal failure was identified in 11(31.4%)patients and confirmed ischemic heart disease in 15(43%)patients. The mean aortic aneurysm diameter was 68+/-25mm. The abdominal aorta was clamped above the renal arteries in 6 (17%) patients.

RESULTS

The hospital mortality was 5.7% (2 patients). Three patients developed an aortic pseudoaneurysm and underwent a redo operation. Another patient developed a femoral anastomotic pseudoaneurysm 7 years after operation and he was treated surgically. The actuarial free-reoperation actuarial survival at 1, 5 and 7 years was 94%, 62% and 50% respectively. The Cox model revealed the delta ESR (p=0.002), ischemic heart disease (p=0.006) and renal failure (p=0.036) as strong predictors for poor overall outcome.

CONCLUSION

Early postoperative outcome in terms of mortality and morbidity seems acceptable, however patients with IAAA have an increased risk for reoperation due to pseudonaneurysm formation. Strong predictors for poor overall outcome seems to be the elevated erythrocyte sedimentation rate, ischemic heart disease and chronic renal failure.

Surgical treatment of inflammatory abdominal aortic aneurysms: Outcome and predictors analysis

OBJECTIVES

The aim of this study is to report our experience on the postoperative outcome of surgical treatment of inflammatory abdominal aortic aneurysm (IAAA).

MATERIALS AND METHODS

Between 1997-2014, 35 patients with IAAA underwent surgery. The mean age was 63 ± 18 years. Chronic renal failure was identified in 11 (31.4%) patients and confirmed ischemic heart disease in 15 (43%) patients. The mean aortic aneurysm diameter was 68 ± 25 mm. The abdominal aorta was clamped above the renal arteries in 6 (17%) patients.

RESULTS

The hospital mortality was 5.7% (2 patients). Three patients developed an aortic pseudoaneurysm and underwent a redo operation. Another patient developed a femoral anastomotic pseudoaneurysm 7 years after operation and he was treated surgically. The actuarial free-reoperation actuarial survival at 1, 5 and 7 years was 94%, 62% and 50%, respectively. The Cox model revealed the delta erythrocyte sedimentation rate (p = 0.002), ischemic heart disease (p = 0.006) and renal failure (p = 0.036) as strong predictors for poor overall outcome.

CONCLUSION

Early postoperative outcome in terms of mortality and morbidity seems acceptable, however, patients with IAAA have an increased risk for reoperation due to pseudonaneurysm formation. Strong predictors for poor overall outcome seem to be the elevated erythrocyte sedimentation rate, ischemic heart disease and chronic renal failure.

Inflammatory aortic aneurysm is associated with increased incidence of autoimmune disease

OBJECTIVE

It has been suggested that certain genetic risk factors indicative of an autoimmune mechanism can be identified in patients with inflammatory aortic aneurysm (IAA). We therefore investigated whether there was a higher incidence of autoimmune diseases in patients with IAA. Further, we explored risk factors, need for in-hospital resources, and early results of treatment, in a case-control study in a university hospital setting. Material and methods From 1983 to 1994, 520 patients were operated because of abdominal aortic aneurysm (AAA). Thirty-one patients had IAA. Control subjects were matched for aneurysm rupture, emergency or elective hospital admission, and date of operation. Two noninflammatory AAA were included for every IAA.

RESULTS

Of the 31 patients with IAA, 6 patients (19%) had autoimmune disease, compared with none of the control subjects (P =.0017). Two patients had rheumatoid arthritis, 2 patients had systemic lupus erythematosus, 1 had giant cell arteritis, and 1 patient had an undifferentiated seronegative polyarthritis diagnosed as rheumatoid arthritis. Nineteen patients (61%) with IAA had involvement of the duodenum, and 8 patients (26%) had hydronephrosis with ureteral involvement. Operating time was longer in the IAA group, which also had a higher need for blood transfusion. Hospital stay, intensive care unit stay, and 30-day mortality were similar in the two groups.

CONCLUSION

Except for longer operating time and more need for blood transfusions in the IAA group, use of hospital resources was similar after operations to treat IAA or noninflammatory AAA. The study findings indicate an association between IAA and autoimmune disease. This is in accordance with other reports that showed a genetic risk determinant mapped to the human leukocyte antigen (HLA) molecule in these patients. Further research is necessary to explore whether IAA might be a separate entity with a role of antigen binding in the origin of the disease.

Management and course of hydronephrosis secondary to inflammatory aneurysms of the abdominal aorta

The objective of this study was to evaluate the management and course of obstructive uropathy secondary to inflammatory aneurysms. From January 1981 to December 2000 a total of 52 patients underwent surgical intervention for inflammatory aneurysms of the abdominal aorta. Eleven of these cases (21%) had obstructive uropathy, which was bilateral in five cases. Preoperative drainage of the urinary tract was done in five ureters in three patients with four double J catheters and one percutaneous nephrostomy; surgical ureterolysis was also carried out in one case. Endoaneurysmorraphy and placement of an aortic graft were performed in all 11 patients. Operative mortality was zero. There was no recurrence of hydronephrosis in seven patients during a mean follow-up of 55 months. Three patients were lost to follow-up and one died. When compared with 41 inflammatory aneurysms in which hydronephrosis did not develop, there were statistically significant differences with respect to lumbar pain and renal insufficiency. The ureter is a structure adjacent to the aorta that is trapped by fibrosis in 21% of patients with inflammatory abdominal aortic aneurysms. The natural tendency of the periaortic fibrosis is to remit following surgery to correct the aneurysm. This results in spontaneous remission of the hydronephrosis, making routine intraoperative manipulation of the ureter unnecessary.

Inflammatory aneurysm in the infrarenal portion of thoracoabdominal aneurysms: an uncommon variant

INTRODUCTION

We present an unusual variant of type IV thoracoabdominal aneurysm with inflammatory changes in part of the aortic wall.

MATERIAL AND METHODS

Between January 1990 and December 2000, 5 male patients (mean age, 68 years) with inflammatory aneurysms of 29 with type IV thoracoabdominal aneurysms (17.2%) underwent surgery. All five had arterial hypertension. The diagnosis of inflammatory aneurysm was made on the basis of clinical suspicion supported by characteristic features on CT scans. Endoaneurysmorraphy was performed in all cases; a tube graft was inserted in three cases, and bifurcation was performed in 2. The macroscopic appearance of periaortic fibrosis was detected at the infrarrenal portion of the aneurysm in the 5 patients, but no retroperitoneal fibrosis was found at the level of the distal thoracic aorta in any case.

RESULTS

There was no operative mortality. Paraparesis was not detected in any patient. One patient had acute kidney failure, and another required an extended stay in the intensive care unit because of respiratory insufficiency. Pathologic examination confirmed the diagnosis of inflammatory aneurysm in all 5 patients, with characteristic adventitial thickening caused by lymphoplasmacytic infiltrate and fibrosis around the ganglionic and nerve structures.

CONCLUSIONS

Type IV thoracoabdominal aneurysm with inflammatory changes can be treated at surgery with a retroperitoneal approach. Usually the fibrotic response is confined to the infrarenal portion of the aneurysm.

Obstructive ARF caused by an inflammatory abdominal aortic aneurysm

Inflammatory abdominal aortic aneurysms are rare entities characterized by dense fibrosis typically enveloping the aortic wall and adjacent structures with distinctive clinical features that differentiate them from typical atherosclerotic aneurysms. The inflammatory process can involve the renal excretory pathways, causing ureteral obstruction in 20% of cases. The authors report 2 cases of complete obstructive anuria secondary to inflammatory aneurysms and discuss the most appropriate management for these situations of hydronephrosis. Surgical repair of the aneurysm usually leads to regression of the inflammatory reaction.

Regression of perianeurysmal fibrosis and ureteral dilation following endovascular repair of inflammatory abdominal aortic aneurysm

An inflammatory component to abdominal aortic aneurysms (AAA) is thought to occur in approximately 5% of cases. Accompanying ureteral entrapment may be involved in 20% of these. Transabdominal repair of inflammatory AAA with ureterolysis may result in increased complications. Many authorities have recommended a retroperitoneal approach to decrease dissection. Similarly, an endovascular approach has been utilized. We report here the results of a patient with an inflammatory AAA with bilateral ureteral obstruction successfully treated with endovascular stent graft repair and bilateral ureteral stents with exclusion of the aneurysm and resolution of hydronephrosis.

Intramural sarcoma of the carotid artery with adventitial inflammation and fibrosis resembling 'inflammatory aneurysm'

A rare case is described of an intramural sarcoma of the right common carotid artery coexisting with adventitial inflammation and fibrosis, resembling 'inflammatory aneurysm', which was resected from a 33-year-old Japanese woman who had presented with a pulsatile mass on the right side of the anterior neck. Grossly, the wall of the carotid artery showed an intimal tear with dissection of the media filled with thrombus. A grayish area, abutting directly onto the dissected space and involving the media and inner adventitia, was composed of alpha-smooth muscle actin-positive and desmin-negative polygonal and spindle cells with large blunt-ended nuclei and coarse granular chromatin arranged into a well-organized interlacing bundle pattern. This portion was thus considered to represent leiomyosarcoma. White to yellow-tan fibrotic tissue present in the adventitial area consisted of extensive lamellar fibrosis with scattered foci of lymphoplasmacytic aggregates and obliterated arteries, and lacked atypical spindle and polygonal cells. These changes accorded with the histopathological findings hitherto described in cases of 'inflammatory aneurysm', which is known to almost exclusively involve the abdominal aorta. We consider this case unique in that the leiomyosarcoma involved an artery other than the aorta, with an 'inflammatory aneurysm'-like reaction in the same site. The possible relationship between these two conditions is discussed.

Inflammatory aortic aneurysms: regression of fibrosis after aneurysm surgery

OBJECTIVES

To evaluate the fate of perianeurysmal fibrosis (PF) following aneurysm surgery.

METHODS

In this single centre study, pre- and postoperative abdominal CT-scans on 21 consecutive patients with inflammatory abdominal aortic aneurysms were compared. CT-scans of 10 randomly chosen patients operated on for abdominal aortic aneurysms without PF in the same period, served as reference group.

RESULTS

Preoperative thickness of PF was assessed as > 1 cm in 11 and < 1 cm in 10 patients. Ureterolysis was performed in seven patients where the fibrosis caused ureteral obstruction. Postoperative CT-scans performed at a median of 24 (range 3-108) months after surgery showed complete regression of the fibrosis in 29%, partial regression in 57% and no change in 14% of the patients. Progression of the fibrosis or persistence of hydronephrosis was not seen. No sign of fibrosis were seen in the 10 controls.

CONCLUSION

This study supports the findings that PF tends to regress after repair of the abdominal aortic aneurysm.

Significance of radiological diagnosis for detection and staging of inflammatory abdominal aortic aneurysm

Operative morbidity and mortality are elevated in patients with inflammatory abdominal aortic aneurysm. Preoperative identification of inflammatory abdominal aortic aneurysm. the detection of the proximal level and of adhesions to adjacent structures are important for surgical management. The sensitivity and specificity of ultrasonography and computed tomography (CT) for identification and staging in 13 patients with inflammatory abdominal aortic aneurysm were studied. Preoperative radiological diagnoses were validated by intraoperative findings. Correct identification of inflammatory abdominal aortic aneurysm could be achieved in 85% by the use of CT and in 62% by ultrasonography. The proximal level of inflammatory abdominal aortic aneurysm was correctly determined by CT in all patients and by ultrasonography in 62%. Using a transperitoneal approach, the condition was considered inoperable in two patients as a result of the suprarenal extent of the aneurysm and because of unremovable adhesions in two other cases. In the latter pair, it was impossible to predict inoperability by radiological findings. Sensitivity (85%) and specificity (100%) of standard radiological techniques to identify inflammatory changes are high. Inoperability caused by suprarenal extent could be detected correctly by routine radiological procedures. However, identification of dense adhesions appears uncertain.

Content and turnover of extracellular matrix protein in human "nonspecific" and inflammatory abdominal aortic aneurysms

Inflammatory aneurysms (IAs) have peculiar macroscopic and histological aspects which make them very different from nonspecific aneurysms (NSAs). These morphological differences seem to be determined by significant modifications of the extracellular matrix. Extracellular matrix protein component concentrations were determined biochemically in infrarenal aortic biopsies from 10 NSAs, five IAs and five non-aneurysmal aortic controls. The concentration of each wall component was expressed in % w/w (relative concentration) and in mg/wall longitudinal cm (absolute concentration) with reference to total protein recovered after hydrolysis and amino acid analysis. The biochemical results were correlated with the histological and ultrastructural features of the specimens. A significant increase in total collagen was observed in the two groups of aneurysms, with respect to the controls (NSA = 285%, IA = 382%). In contrast the 80-90% decrease in the relative concentration of elastin observed in both types of aneurysm was less marked (NSA = 55%, IA = 39%). This fall was not significant when expressed in mg/cm, although elastin derived peptide (EDP) levels in the plasma of these patients was significantly higher than in age-matched controls. The concentration of the soluble collagen fraction appeared significantly higher (Mann-Whitney, p < 0.05) in the IAs with respect to the NSAs, whilst no differences were observed between the two groups regarding the concentration of insoluble elastin and of wall and plasma EDPs. As well as providing evidence of increased elastin turnover, this study emphasises the conspicuous modifications of collagen deposition in the wall of abdominal aortic aneurysms which appeared more marked in the inflammatory group.(ABSTRACT TRUNCATED AT 250 WORDS)

Postoperative course of inflammatory abdominal aortic aneurysms

Of 779 patients undergoing repair of abdominal aortic aneurysms over a 7-year period (1984-1990), 40 (5.1%) had gross features of inflammatory abdominal aortic aneurysms (IAAAs). Twenty IAAAs were assessed by CT scan preoperatively and postoperatively to evaluate the outcome of the inflammatory layer of the aneurysm in 19 cases. Complete postoperative regression was observed in nine cases (47.3%), partial regression in four (21%), and stable lesions in six (31.7%). No roentgenographic progression was found. The comparison between the roentgenologic outcome and preoperative clinical features (age, sex, erythrocyte sedimentation rate, and abdominal lumbar pain), pathologic findings, and follow-up time revealed a significant correlation (p < 0.05) between the postoperative outcome and the histologic findings in the wall (cell density and cell/fibrosis ratio). Complete regression of inflammation was observed when high cell density (16 +/- 0.7 cells/2116 microns 2) and a cell/fibrosis ratio > 1 were found. On the contrary, little or no regression of inflammation occurred when a low cell density (3.4 +/- 0.3 cells/2116 microns 2) and a cell/fibrosis ratio < 1 were found. Although it is generally thought that inflammation in IAAAs regresses after surgical repair, in our study, 31.7% of the postoperative CT scans showed no change. Histologically, the variability of morphologic aspects seemed to correlate with the relative proportions of cellular infiltrate and interstitial fibrosis in the aneurysmal wall. These proportions determine the postoperative course of the inflammation layer and, most likely, the response of the latter to steroid therapy as well.

Inflammatory aortic aneurysms: characteristic appearance on magnetic resonance imaging

Ten to 15% of all aortic aneurysms show inflammatory change. They are characteristically covered on their anterior and lateral sides with thick white fibrous tissue. Peri-aortic fibrosis may spread into the retroperitoneum to encase and obstruct adjacent organs making operative treatment more difficult and increasing the operative morbidity and mortality. Fifteen patients with inflammatory aneurysms and 46 patients with simple non-inflammatory aneurysms were studied prospectively. Each patient underwent magnetic resonance imaging (MRI) using a Picker Vista MR2055 scanner operating at 0.5 tesla. Each scan was reviewed by a radiologist (G.G.H.) preoperatively and a diagnosis of inflammatory or non-inflammatory aneurysm made. At operation, the diagnosis of aneurysm type was made on macroscopic features of inflammatory change, and confirmed histologically using previously published criteria. The radiological diagnosis was found to correspond to the surgical and pathological diagnosis in all cases. In cases of inflammatory aortic aneurysm the aneurysm wall appeared laminated on MRI scan, showing three or more bright, high-signal layers. These appearances of inflammatory change are characteristic, and were present in all 15 patients with such aneurysms. There were no false positives among those patients with simple aneurysms, and no false negatives. Operative specimens of aortic wall were taken from four patients with inflammatory aortic aneurysms and four patients with simple non-inflammatory aortic aneurysms, and subjected to MRI scanning. The characteristic banding appeared only in the inflammatory aneurysm wall samples. Magnetic resonance imaging is a highly sensitive investigative technique for the detection of inflammatory aneurysms, showing characteristic changes. These changes are also seen in in vitro scans of wall samples from inflammatory aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic activity in inflammatory and non-inflammatory aneurysms of the abdominal aorta

Inflammatory aneurysms of the abdominal aorta (IAA) comprise 10-15% of all aortic aneurysms (AA) but their aetiology and pathogenesis are obscure. Destruction of mural elastin is a prominent feature of IAA, and both increased elastolysis and decreased inhibition of elastolysis have been implicated. In order to study these factors, we have examined the peripheral blood of three groups of patients; 15 with inflammatory aortic aneurysms (IAA), 61 with simple aortic aneurysms (SAA) and 35 with aorto-iliac occlusive disease (OD). In all cases, alpha-1-anti-trypsin (A-1-AT), alpha-2-macroglobulin (A-2-MG), elastase inhibitory activity (E.I.A.), elastase-anti-trypsin complex, C-reactive protein (CRP), caeruloplasmin (CP) and plasma viscosity were measured. Patients with IAA had a significantly higher plasma viscosity (Mann-Whitney, p less than 0.05), E.I.A. (Mann-Whitney, p less than 0.01) and levels of A-1-AT, CRP, CP and elastase/anti-trypsin complex (Mann-Whitney, all p less than 0.05) than patients in the other two groups. There was no difference in the levels of A-2-MG between any of the groups. This study refutes the theory that reduced inhibition of elastase activity predisposes to the formation of SAA. In patients with IAA, raised marker levels indicate ongoing destruction of elastin, and suggest a difference in pathogenesis between IAA and SAA. The study also suggests that IAA are highly active metabolically, as opposed to the more degenerative SAA.

The cellular component in the parietal infiltrate of inflammatory abdominal aortic aneurysms (IAAA)

Eight cases of inflammatory abdominal aortic aneurysm (IAAA) (group I) and a control group of ten cases of atherosclerotic abdominal aortic aneurysm (AAA) with little or no parietal inflammatory infiltrate (group II) were studied; using light microscopy, transmission electron microscopy (TEM), and immunohistochemistry. These were used to define cell composition in the inflammatory process, the degree of cell activation and alteration of connective tissue. Large numbers of B lymphocytes were present in IAAA with preservation of the T4/T8 ratio. In addition, HLA-DR and the IL2-R antigen (specific for activated cells) were widely expressed in the cell population. The interstitial matrix contained deposits of IgG, IgM and C3c together with an increase in type III collagen and a reduction in elastin which appeared fragmented and swollen. This study, therefore, characterised the cellular component of the parietal inflammatory infiltrate in IAAA. The degree of activation shown by these cell elements and the activation of complement suggest that the relevant antigen may have been localised in the aneurysm wall at the time of observation.