Immunoglobulin G4-related hepatic artery aneurysm

A 49-year-old man who was a current smoker with a history of hypertension, dyslipidemia, and coronary artery disease after coronary stent placement presented because of abdominal and back pain. Contrast-enhanced computed tomography showed a 30-mm, large hepatic artery aneurysm. Resection of the aneurysm and autogenous vein bypass grafting was performed, which resulted in a successful outcome without any complications. Pathologic examination of the aneurysm confirmed that it was related to immunoglobulin G4 (IgG4). The patient's serum IgG4 level was within the normal range, and no other signs of IgG4-related organ lesions were observed.

Heterogeneous Characteristics of Patients with Inflammatory Abdominal Aortic Aneurysm. Systematic Review of Therapeutic Solutions

BACKGROUND

Endovascular repair of inflammatory abdominal aortic aneurysms (IAAAs) has emerged as an alternative to open surgery, but direct comparisons are limited. The aim of the study was to compare clinical outcomes of endovascular and open repair for IAAA according with specific clinical characteristics.

METHODS

We performed a literature review of reports describing patients who had open or endovascular repair for IAAA. A literature search was performed in June 2022 by 2 investigators who conducted a review of papers reported in PubMed, Embase, MEDLINE, and Cochrane Database. The strings "Inflammatory aneurysm" and "Abdominal Aortic Aneurysms" were used. There was no language restriction and screened reports were published from March 1972 to December 2021. We identified 2,062 patients who had open (1,586) or endovascular repair (476) for IAAA. Primary outcomes were operative mortality and morbidity. Secondary outcomes were complications during follow-up (mean follow-up: 48 months). Propensity score matching was performed between patients who had open or endovascular surgery.

RESULTS

In Western countries, propensity-weighted postoperative mortality (in-hospital) (1.5% endovascular vs. 6% open) and morbidity rates (6% vs. 18%) were significantly lower in patients who had endovascular repair (P < 0.0001); patients with larger aneurysm (more than 7 cm diameter), signs of active inflammation, and retroperitoneal rupture of the aneurysm had better outcomes after endovascular repair than after open surgery. Hydronephrosis was present in 20% of the patients. Hydronephrosis regressed in most patients when signs of active inflammation were present suggesting an acute onset of the hydronephrosis itself (fever, elevated serum C Reactive Protein) either after endovascular or open surgery. Long-standing hydronephrosis as suggested by the absence of signs of active inflammation rarely regressed after endovascular surgery despite associated steroid therapy. During a mean follow-up of 48 months, propensity-weighted graft-related complications were more common in patients who had endovascular repair (20% vs. 8%). For patients from Asia, short-term and medium-term results were similar after open and endovascular repair. IAAAs related with aortitis were more common in Asia. In Western countries, IAAAs were commonly associated with atherosclerosis.

CONCLUSIONS

Patients with IAAA represent a heterogeneous population, suggesting biological differences from continent to continent; conservative therapy and endovascular or open surgery should be chosen according to the patient clinical condition. Endovascular repair presents advantages in patients with signs of active inflammation and contained rupture of the IAAA and larger aneurysms. Hydronephrosis, without signs of active inflammation, rarely regresses after endovascular repair associated with steroid therapy. Further studies are needed to establish the long-term results of endovascular repair.

The Incidence of IgG4-Related and Inflammatory Abdominal Aortic Aneurysm Is Rare in a 101 Patient Cohort

Abdominal aortic aneurysms (AAA) are the most frequent aortic dilation, with considerable morbidity and mortality. Inflammatory (infl) and IgG4-positive AAAs represent specific subtypes of unclear incidence and clinical significance. Here, histologic and serologic analyses with retrospective clinical data acquisition are investigated via detailed histology, including morphologic (HE, EvG: inflammatory subtype, angiogenesis, and fibrosis) and immunhistochemic analyses (IgG and IgG4). In addition, complement factors C3/C4 and immunoglobulins IgG, IgG2, IgG4 and IgE were measured in serum samples and clinical data uses patients' metrics, as well as through semi-automated morphometric analysis (diameter, volume, angulation and vessel tortuosity). A total of 101 eligible patients showed five (5%) IgG4 positive (all scored 1) and seven (7%) inflammatory AAAs. An increased degree of inflammation was seen in IgG4 positive and inflAAA, respectively. However, serologic analysis revealed no increased levels of IgG or IgG4. The operative procedure time was not different for those cases and the short-term clinical outcomes were equal for the entire AAA cohort. Overall, the incidence of inflammatory and IgG4-positive AAA samples seems very low based on histologic and serum analyses. Both entities must be considered distinct disease phenotypes. Short-term operative outcomes were not different for both sub-cohorts.

A case of aortoduodenal fistula caused by IgG4-related periaortitis

An 86-year-old man who underwent endovascular aortic repair for impending rupture of an abdominal aortic aneurysm a year ago presented to our hospital because of fatigue and black stools. Multiple bacterial specimens were detected in blood cultures, and computed tomography following oral administration of gastrografin demonstrated gastrografin in the abdominal aorta. The diagnosis of aortic duodenal fistula was confirmed and emergency abdominal aortic replacement was performed. The pathological findings of the aorta included a large number of immunoglobulin G4 (IgG4)-positive plasma cells infiltrating all layers of the aortic wall, with particularly marked thickening of the adventitia. The serum IgG4 level was 241 mg/dl and IgG4-related periaortitis was diagnosed. Aortoduodenal fistula is a rare but fatal complication of IgG4-related periaortitis. Patients should be followed carefully after endovascular aortic repair for inflammatory abdominal aortic aneurysms.

Multidisciplinary diagnosis and management of inflammatory aortic aneurysms

BACKGROUND

Inflammatory abdominal aortic aneurysms (IAAAs) are a variant involving a distinct immunoinflammatory process, with nearly one half believed to be associated with IgG4-related disease (IgG4-RD).

METHODS

MEDLINE and Google Scholar searches were conducted for English-language publications relevant to inflammatory aortic aneurysms from January 1970 onward. The search terms included inflammatory aortic aneurysms, aortitis, periaortitis, IgG4-related disease, and retroperitoneal fibrosis. Relevant studies were selected for review based on their relevance.

RESULTS

Morphologically, IAAAs are characterized by a thickened aneurysm wall often displaying contrast enhancement and elevated metabolic activity on fluorine-18 fluorodeoxyglucose-positron emission tomography imaging. A strong association exists with perianeurysmal and retroperitoneal fibrosis. Although the rupture risk appears lower with IAAAs than with noninflammatory abdominal aortic aneurysms (AAAs), the currently recommended diameter threshold for operative management is the same. Open repair has been associated with increased morbidity compared with noninflammatory AAAs, and a retroperitoneal approach or minimal dissection transperitoneal approach has been recommended to avoid duodenal and retroperitoneal structural injuries. Endovascular aneurysm repair has been increasingly used, especially for patients unfit for open surgery. It is important to exclude an infectious etiology before the initiation of immunosuppressive therapy or operative repair. Multimodality imaging follow-up is critical to monitor disease activity and secondary involvement of retroperitoneal structures by the associated fibrotic process. Maintenance of immunosuppressive therapy will be needed postoperatively for most patients with active systemic disease, especially those with IgG4-RD and those with persistent symptoms. Additional interventions aimed at ureteral decompression could also be required, and lifelong follow-up is mandatory.

CONCLUSIONS

Preoperative multimodality imaging is a diagnostic cornerstone for assessment of the disease extent and activity. IgG4-RD is an increasingly recognized category of IAAAs, with implications for tailoring adjunctive medical therapy. Open surgical repair remains the procedure of choice, although endovascular aneurysm repair is increasingly being offered. Maintenance immunosuppressive therapy can be offered according to the disease activity as assessed by follow-up imaging studies.

Surgical strategy of IgG4-related inflammatory abdominal aortic aneurysm with preoperative steroid therapy: A case report

Immunoglobulin G4 (IgG4)-related disease, characterized by high serum IgG4 concentrations and IgG4-positive plasma cell infiltration, often presents as an inflammatory aneurysm. We herein report the case of a 78 year-old man, presenting with elevated inflammatory markers and IgG4 concentrations, who was diagnosed with IgG4-related inflammatory abdominal aortic aneurysm with dense perianeurysmal fibrosis. Before the surgical intervention, steroid therapy was administered to resolve his perianeurysmal inflammatory fibrosis. Half a year after the initiation of steroid therapy, there was an improvement in serum inflammatory markers and IgG4 concentrations, and the perianeurysmal fibrosis had regressed. Thus, we performed a surgical intervention including resection of the aneurysm and interposition with a prosthetic graft. Histopathological examination demonstrated few IgG4-positive plasma cells were distributed in the adventitia, which was suspected to be associated with the preoperative steroid therapy. This case study suggests preoperative steroid therapy is a useful therapeutic strategy for IgG4-related abdominal aortic aneurysm because it allows the use of open surgical procedures with reduced surgical risk.

A rare case of ulcerative colitis in a patient who developed acute ischemic colitis associated with Takayasu arteritis

Intestinal ischemia is a rare complication of Takayasu arteritis (TAK), which often requires colectomy. We report the case of a 27 year-old man with ulcerative colitis (UC), who was admitted to our hospital due to abdominal pain. Computed tomography revealed an edematous wall of the ascending colon with ascites and a thickened aortic wall with mild stenosis of the superior mesenteric artery (SMA), suggesting large vessel vasculitis, especially TAK. Colonoscopy revealed acute ischemic colitis associated with mild stenosis of the SMA caused by TAK, but there was no worsening of UC. The patient was successfully treated with conservative therapy.

Hybrid treatment of a giant coronary artery aneurysm in a patient with immunoglobulin G4-related disease

A 62-year-old man was diagnosed with a giant coronary artery aneurysm associated with immunoglobulin G4 (IgG4)-related disease. He had previously undergone two thoracic operations with sternotomies and abdominal aortic aneurysm repair for IgG4-related aortopathy. We opted for hybrid open and endovascular repair to reduce risk and avoid complications of a resternotomy and extracorporeal circulation. This first successful case of hybrid repair of a giant coronary artery aneurysm shows that the procedure is safe and feasible in patients with IgG4-related vasculopathy. It is critical to carefully monitor these patients for the occurrence of new IgG4-related aneurysms and other manifestations of vasculopathy.

Exacerbation of immunoglobulin G4-related inflammatory abdominal aortic aneurysm after endovascular repair

A 78-year-old male was admitted to our hospital with lumbar pain and was found to have an abdominal aortic aneurysm (AAA) and femoral artery aneurysm (FAA). Initially, the patient underwent endovascular aneurysm repair (EVAR) for the AAA and aneurysmectomy for the FAA. The FAA was diagnosed by histology as immunoglobulin G4-related disease (IgG4-RD). The preoperative serum IgG4 level was within the normal range, although a slight serum interleukin-6 (IL-6) elevation was observed. Four years later, the AAA-sac diameter had expanded and the serum levels of both IgG4 and IL-6 levels had increased. Six years after the initial EVAR, aneurysmorrhaphy of AAA-sac was performed. The resected specimen revealed adventitial fibrosis and prominent lymphoplasmacytic infiltrate with regulatory T cells, satisfying histological diagnostic criteria for IgG4-RD. Immunoreactive matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, and IL-6 were detected within numerous spindle cells in the adventitia of both the FAA and the AAA-sac. Five months after the aneurysmorrhaphy, the residual AAA-sac was again enlarged with a thickened wall that accumulated [¹⁸ F] fluoro-2-deoxy-D-glucose (FDG-PET) on positron emission tomography; these findings were paralleled by increased levels of serum IgG4 and IL-6. Therefore, persistent inflammation after EVAR may be attributed to the inflammatory sequelae of IgG4-RD.

Adventitial matrix metalloproteinase production and distribution of immunoglobulin G4-related abdominal aortic aneurysms

Objective

IgG4-related diseases are systemic inflammatory fibrous lesions characterized by elevated serum IgG4 and infiltration of IgG4-positive plasmacytes. They can manifest in vascular lesions as frequently formed aneurysms with prominent thickening of the adventitia (IgG4-related abdominal aortic aneurysm; IgG4-AAA). Matrix metalloproteinases (MMPs) degrade the extracellular matrix, mainly in the tunica media, resulting in destruction of aortic structures to cause enlargement of the aneurysm. However, the expression of adventitial MMPs in IgG4-AAAs is poorly understood.

Methods

MMPs and MMPs-presenting cells in the adventitia of IgG4-AAAs (n = 19) of human surgical specimens were evaluated by immunohistochemistry and dual messenger RNA in situ hybridization. The results were compared with those from control groups of non-IgG4-related inflammatory AAA (n = 18), atherosclerotic AAA (aAAA; n = 11), and autopsy cases (n = 11). Preoperative serum MMPs levels of these groups were compared with the histologic data.

Results

Expression of MMP-9, MMP-2, and MMP-14 at the protein and messenger RNA levels in the adventitia was significantly higher in IgG4-AAAs than in controls. Other MMPs were scarce. The total number of MMP-9-positive cells was positively correlated with the diameter of the aneurysm (R = 0.461; P = .031), the adventitial thickness (R = 0.688; P < .001), and the number of IgG4-positive cells (R = 0.764; P < .001). Within lymphoid follicles, MMP-9-presenting cells were predominantly detected in large follicular dendritic cells, followed by histiocytes, fibroblasts, and plasmacytic dendritic cells. Outside lymphoid follicles, fibroblasts, and histiocytes mainly expressed MMP-9, and tissue dendritic cells also produced MMP-9. The levels of MMP-9 derived from follicular dendritic cells and histiocytes and plasmacytic dendritic cells outside lymphoid follicles were significantly higher in IgG4-AAA group than in other groups. Expression of adventitial MMP-2 and MMP-14 by histiocytes and fibroblasts was predominantly detected outside lymphoid follicles. Serum MMP-9 levels were significantly higher in IgG4-AAAs (835 ng/mL) than in controls, and correlated with serum IgG4 levels and the total numbers of adventitial MMP-9-positive cells, whereas serum MMP-2 levels did not differ among the three aneurysmal groups.

Conclusions

MMP-9 production in adventitial immune cells concerning lymphoid follicles was characteristic of IgG4-AAAs and might work in its activity with aneurysmal dilatation and adventitial thickening. Expressions of adventitial MMP-2 and MMP-14 were detected in histiocytes and fibroblasts outside lymphoid follicles, and were less concerned with the activity of IgG4-AAAs.

This retrospective multicenter study analyzed adventitial matrix metalloproteinases (MMPs) production in 19 patients with IgG4-related abdominal aortic aneurysms (AAAs) and 40 control cases. Adventitial MMP-9 production by various kinds of immune cells was increased in patients with IgG4-related AAAs and concerned with IgG4-AAA activity to cause aneurysmal progression and adventitial fibrosis, compared with aAAA. Serum MMP-9 levels reflected histologic MMP-9. Adventitial MMP-2 and MMP-14 were less concerned with IgG4-AAA activity. Thus, for IgG4-AAA patients, monitoring serum MMP-9 level might be the exacerbating factors related to adverse events during the treatment course.

Arterial-bronchial fistula from ruptured immunoglobulin G4-related subclavian artery aneurysm

Immunoglobulin G4 (IgG4)-related disease is a systemic chronic inflammatory disease caused by infiltration of IgG4-positive plasma cells into the systemic organs. IgG4-related arterial disease is relatively rare not only in the aorta but also in the small to medium-sized arteries. If IgG4-related vasculitis is suspected on the basis of the preoperative medical history and radiologic and serologic examination findings, a definitive diagnosis can be obtained by open repair and pathologic examination to determine the prognosis and need for additional treatment. Here, we report the successful treatment of arterial-bronchial fistula caused by a ruptured IgG4-related subclavian artery aneurysm.