Inflammatory abdominal aortic aneurysm
Introduction
Introduction to inflammatory abdominal aortic aneurysm In 1972, Walker et al first proposed the concept of inflammatory abdominal aortic aneurysm (inflammatoryabdominalaneurysm), which is characterized by chronic inflammation and obvious fibrosis associated with tissues surrounding the aneurysm, often with duodenum, ureter, left renal vein, and lower Close adhesion of the vena cava. basic knowledge The proportion of sickness: 0.01% Susceptible people: no special people Mode of infection: non-infectious Complications: Arthritis
Cause
Causes of inflammatory abdominal aortic aneurysm
(1) Causes of the disease
At present, the existence of abdominal aortic aneurysm is considered to be the initiating factor of inflammatory process. Almost all atherosclerotic abdominal aortic aneurysms have different degrees of inflammatory reaction. After clinical removal of inflammatory abdominal aortic aneurysm, the inflammatory reaction will subside. Some people think that abdominal aortic aneurysm is caused by lymphatic stasis and post-peritoneal edema in the peritoneal lymphatic vessels, which stimulates fibrosis. It is also believed that inflammatory abdominal aortic aneurysm is a local autoimmune reaction in atherosclerotic plaque. Wax leakage to the surrounding tissue caused by allergens; others believe that embolization of aortic nourishing blood vessels caused mesenteric damage leading to the formation of inflammatory abdominal aortic aneurysm.
(two) pathogenesis
1. Pathological morphology usually shows inflammatory abdominal aortic aneurysm in white, shiny appearance, some people call it "white porcelain" or "iceberg-like" change, obvious fibrosis around the aneurysm, and adjacent twelve The intestine, small mesentery, left renal vein, ureter, inferior vena cava and other close adhesions, the lesion can be extended to the beginning of the superior mesenteric artery, the common iliac artery is placed, the front wall of the aneurysm is thickened, and the posterior wall is often thickened. It does not thicken, is weak and can erode adjacent vertebral bodies, and is a site that is easily broken.
The histological changes were thickened in the adventitia and media, and the intima was often characterized by obvious atherosclerosis. The middle and outer membranes showed acute, chronic inflammatory cell infiltration including giant cells, most of which were activated T lymphocytes. The smooth muscle of the middle membrane disappears and the elastic fiber breaks. The granulation tissue proliferates in the early stage of the adventitia, and contains nerve and vascular components. In the late stage, it can be fibrotic and fuse with the middle membrane and the outer membrane to form obvious fibrotic changes.
2. The pathological type is classified into 2 types according to the morphological characteristics of inflammatory abdominal aortic aneurysm:
Type I (fibrosis type): characterized by obvious fibrosis around the abdominal aortic aneurysm, often causing ureteral involvement and obstruction.
Type II (cystic overhang): characterized by localized cystic protrusion of abdominal aortic aneurysm, almost all pseudoaneurysms, which are prone to rupture compared with type I. The pathological features are inflammatory hypertrophy of the adventitia. Infiltration of inflammatory cells and damage to nourish blood vessels, middle membrane rupture and other manifestations.
Prevention
Inflammatory abdominal aortic aneurysm prevention
First, we should actively prevent the occurrence of atherosclerosis (primary prevention), if it has occurred, should be actively treated, prevent the development of the disease and strive for its reversal (secondary prevention). Complications have occurred, timely treatment, to prevent its deterioration, and to extend the life of patients (third-level prevention).
Complication
Inflammatory abdominal aortic aneurysm Complications
Common arterial embolism of the lower extremity, hydronephrosis caused by compression of the ureter and rupture of the abdominal aortic aneurysm, etc., the rupture of the abdominal aortic aneurysm is the main cause of sudden death, abdominal aorta and abdominal aorta Venous fistula is a rare complication, and the tumor occasionally sticks to adjacent intestinal ducts.
Symptom
Symptoms of inflammatory abdominal aortic aneurysm Common symptoms Low back pain ESR increased ureteral obstruction
Inflammatory abdominal aortic aneurysm has almost all symptoms, mostly abdominal, low back pain, sometimes misdiagnosed as abdominal aortic aneurysm rupture, patients may have weight loss and increased erythrocyte sedimentation rate, ureteral involvement may cause ureteral obstruction, hydronephrosis, Long-term can lead to impaired renal function, increased blood urea nitrogen and inosine levels, and even evolved into uremia, duodenal involvement can cause intestinal obstruction, and anemia, loss of appetite, etc., palpation of the abdomen can be touched In the pulsatile mass, the three clinical manifestations of abdominal aortic aneurysm, ureteral centripetal deviation and erythrocyte sedimentation rate are summarized as "triad" of inflammatory abdominal aortic aneurysm.
Examine
Examination of inflammatory abdominal aortic aneurysm
There may be increased ESR and anemia, in addition to blood BUN, Cr and renal function tests.
1. X-ray plain film abdomen positive, lateral film can be found in the aneurysm wall of eggshell calcification, and common inflammatory abdominal aortic aneurysm has signs of vertebral erosion.
2. B-ultrasound can be found that the abdominal aortic aneurysm wall is significantly thickened, and there is a hypoechoic halo in front and side, which needs to be differentiated from the hematoma around the aneurysm.
3. CT scan is of great value in the diagnosis of inflammatory abdominal aortic aneurysm. The typical appearance of calcified abdominal aortic aneurysm has a ring-shaped soft tissue density in front of and on the side of the wall. It is easily misdiagnosed as a hematoma around the abdominal aortic aneurysm. It can be enhanced, but the density is slightly lower than the blood in the aorta. Some people call this the performance of "Mantle sign".
4. Intravenous pyelography (IVP) can be found in the ureteral centripetal deviation and / or hydronephrosis, such as abdominal aortic aneurysm in patients with this performance should consider the possibility of inflammatory abdominal aortic aneurysm.
5. Aortic angiography sometimes shows an increase in the aortic bifurcation angle and an irregular image of the abdominal aortic aneurysm wall, which is helpful for the diagnosis and determination of the surgical plan.
Diagnosis
Diagnosis and diagnosis of inflammatory abdominal aortic aneurysm
If patients with abdominal aortic aneurysm have increased erythrocyte sedimentation rate, weight loss, abdominal pain and ureteral obstruction, and renal function changes, combined with B-ultrasound, CT and intravenous pyelography (IVP) can often make a diagnosis.
Sometimes it needs to be differentiated from primary retroperitoneal fibrosis: the fibrotic thickening of inflammatory abdominal aortic aneurysm is mostly located in front of and on the side of the aneurysm, often without thickening at the back, and primary retroperitoneal fibrosis is often dominant. The fibrosis of the arteries is thickened throughout the week, and the aorta usually does not expand.
