retroperitoneal fibrosis
Introduction
Introduction to retroperitoneal fibrosis Retroperitoneal fibrosis (RPF) was first reported by French urology surgeon Albrran in 1905 and used the concept of retroperitoneal fibrosis until 2948, after Ormond reported 2 cases of retroperitoneal fibrosis, the case of this disease The report has gradually increased and is being recognized by more and more clinicians. The pathological changes of the disease are characterized by retroperitoneal fibrous tissue hyperplasia and extensive peritoneal fibrosis. The clinical manifestations are closely related to the degree of compression of retroperitoneal tissues or organs (such as ureters). basic knowledge The proportion of illness: the incidence rate is about 0.003%-0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: high blood pressure, headache
Cause
Retroperitoneal fibrosis
(1) Causes of the disease
About 2/3 of the causes of retroperitoneal fibrosis are unknown, which is called idiopathic retroperitoneal fibrosis in clinical practice; the other 1/3 of the cases may be related to certain drugs, tumors, trauma or Surgery, hemorrhage, extravasation, radiation, non-specific gastrointestinal inflammation (such as Crohn's disease), appendicitis, diverticulitis, various infections (such as tuberculosis, histoplasmosis, syphilis, actinomycosis) and other factors, It is called secondary retroperitoneal fibrosis.
(two) pathogenesis
1. Pathogenic factors A large number of clinical studies have found that the following factors may be related to retroperitoneal fibrosis,
(1) autoimmune deficiency: clinical data show that 8% to 15% of patients with idiopathic retroperitoneal fibrosis can be accompanied by fibrosis other than retroperitoneal, with a history of scleroderma, eosinophilia , nodular arteritis, systemic lupus erythematosus, glomerulonephritis, Riedle thyroiditis, sclerosing cholangitis, mediastinal fibrosis and posterior fibrotic pseudotumor, suggesting that retroperitoneal fibrosis may be a systemic sclerosing disease a partial manifestation of the disease, may also indicate that the disease may be related to immune defects,
(2) Side effects of drugs: Since 1964, Grahacn reported that patients with methyl methionine butanolide have developed retroperitoneal fibrosis, similar cases have been reported in the literature, long-term users, their retroperitoneal fibrosis The incidence can reach 10% to 12.4%, in addition, beta blockers (propranolol), antihypertensive drugs (methyldopa, reserpine, hydralazine), analgesics (aspirin) Drugs such as phenacetin can also induce the disease, but their causal relationship with retroperitoneal fibrosis needs further study.
(3) Infection and inflammation: As early as 1948, Ormond considered the disease to be a type of retroperitoneal inflammation, while Mathisen et al. suggested that retroperitoneal fibrosis may be associated with infection of the abdominal and lower extremity viruses, as reported in the literature, with the peritoneum. Post-fibrosis-related infections and inflammation include: tuberculosis, syphilis, actinomycosis and various fungal infections; non-specific infections such as diverticulitis, appendicitis; ulcerative colitis, Crohn's disease, blood vessels of skin and subcutaneous tissue Inflammatory diseases such as inflammation and other immune factors; inflammatory lung injury, thrombophlebitis, pancreatitis and other inflammatory diseases can also cause retroperitoneal fibrosis.
(4) Malignant tumors: retroperitoneal fibrosis induced by malignant tumors accounts for 8% to 10% of all cases. It has been reported that malignant tumors that cause connective tissue hyperplasia and fibrosis include: breast cancer, lung cancer, thyroid cancer, Gastric cancer, colon cancer, genitourinary cancer (kidney cancer, bladder cancer, prostate cancer and uterine cancer), Hodgkin's disease and other malignant lymphomas, certain sarcomas, carcinoids, etc.
(5) aortic aneurysm: a common type of retroperitoneal fibrosis is reported in the literature around the aneurysm fibrosis, fibrosis can only be around the aneurysm, may also laterally wrapped around the ureter and cause obstruction, according to reports, The incidence of fibrosis around the aorta or aortic aneurysm is 5% to 23%.
(6) Injury: Clinical data show that trauma, retroperitoneal hematoma and radiation damage can lead to retroperitoneal fibrosis.
(7) Asbestos: Boulard and Sauni et al reported in 1995 and 1998 that 2 patients and 7 patients with retroperitoneal fibrosis had a history of close exposure to asbestos, and their chest X-ray showed pleural plaque or calcification. Circular lung insufficiency, etc., autopsy also found asbestos bodies behind the retroperitoneum, suggesting that asbestos may be one of the causes of retroperitoneal fibrosis.
2. Pathogenic process Many causes can cause retroperitoneal fibrosis, and the pathological process is:
(1) Drug-induced retroperitoneal fibrosis: common is methyl lysergic acid butanamide, which is a semi-synthetic ergot derivative, a serotonin antagonist, which can competitively inhibit serotonin receptors when taken for a long time. Increased endogenous serotonin (serotonin), in patients with carcinoid syndrome, elevated serotonin can cause fibrosis in the retroperitoneal, lung, pleural and gastrointestinal tract tissues, comprehensive literature reports, The following points may be related to the cause of retroperitoneal fibrosis:
1 endogenous serotonin elevation, causing a carcinoid syndrome-like abnormal fibrosis reaction in susceptible patients.
2 Degranulation of mast cells, release of serotonin and cause local inflammatory reaction.
3 may cause prolonged aortic palsy and ischemia, thereby causing inflammation and fibrosis around the aorta.
4 ergot alkaloids may cause disease as a hapten causing autoimmunity or hypersensitivity in the body.
(2) Infection-induced retroperitoneal fibrosis: Mathisen et al believe that certain specific and non-specific infections can cause retroperitoneal fibrosis, because viral infection causes inflammation and blockage of lymphatic vessels, and lymphocytes and plasma cells enter the interstitial space. , causing protein deposition and fibroblast release, which in turn leads to collagenation.
(3) retrograde retrograde fibrosis caused by malignant tumor: It is speculated that the mechanism may be that the malignant tumor cells stimulate the peritoneum after small metastases, induce a strong reaction of the peritoneum, cause connective tissue reaction and hyperplasia, form a fibrous mass, and this small metastasis The lesion and its induced retroperitoneal fibrosis should be differentiated from retroperitoneal metastatic lymph nodes and some primary malignant tumors.
(4) retroperitoneal fibrosis caused by aneurysm: the mechanism of fibrosis around the aneurysm is unknown. It is believed that the "leakage" of aortic aneurysm may be the cause of fibrosis around the aneurysm, but it is not found in the fibrotic plate. Blood deposition, about 10% of aortic aneurysms are inflammatory, also known as inflammatory aneurysms, so it is believed that inflammatory infiltration around the aortic aneurysm may be related to it. In recent years, it has been found that inflammation and infiltration around the aortic aneurysm Post-fibrosis leads to periarteritis, and there is no difference in histopathology, the difference being whether the aorta is dilated or not.
(5) retroperitoneal fibrosis in the atherosclerotic region: in recent years, retroperitoneal fibrosis has been found in the aortic region where the arterial wall has severe atherosclerosis and weakened arterial layer. The pathogenesis is unknown. At present, most scholars believe that this Disease is an autoimmune disease that is highly sensitive to the body's waxy antigens of aortic atherosclerotic plaques and induces immune responses. Bullock and Zdrojewski et al., when atherosclerotic plaque ruptures, its wax The sample (an insoluble polymer of oxidized lipids and proteins) leaks out into the peritoneal aorta surrounding tissue through the thinned arterial wall. The waxy substance acts as an antigen to cause an autoimmune reaction, and chronic inflammation occurs in the surrounding tissues. The reaction, which in turn induces fibrous tissue hyperplasia and forms a fibrotic plate, Hughes et al. found in the study that a large number of macrophages accumulate around the blood vessels and their walls of atherosclerosis, lymphocytes and related antibodies, in macrophages Wax-like substance is visible in the inner and adjacent reactive lymphoid nodules. Immunohistochemistry also found a large number of tissue macrophage immunophenotypes and fine Cytokines, histopathology showed that the pathological changes of aortic atherosclerosis are similar to those of aortitis, so it is also called "chronic aortic periarthritis". Ramshaw is found in the specimens of the aortic adventitial tissue with chronic periarteritis. mRNA expression of IL-1, IL-2, IL-2 receptor and IL-4 increased with the degree of inflammation of the outer membrane, and the expression of -IFN mRNA was also increased. However, this theory cannot Explain the causes of retroperitoneal fibrosis in children without atherosclerotic disease.
3. Histopathological retroperitoneal fibrotic lesions mainly centered on the abdominal aorta, mostly in the lumbosacral retroperitoneum, the upper edge can reach the adrenal gland, the lower edge extends to the pelvic wall, and the diaphragm can be integrated into the mediastinal fibrosis. It has been reported that the largest range from the aortic root to the bifurcation, fibrosis usually begins in the aortic bifurcation or below near the humeral condyle, asymmetrical growth from the midline to one or both sides, and then along the retroperitoneal The arteries and bifurcations grow to the periphery, and the pelvic vessels can reach the pelvic vessels. The upper pedicles, the abdominal aorta, the inferior vena cava, and the common iliac vessels are surrounded by them. The fibrosis extends to both sides, the ureter, the kidney pedicle, and the gonads. Blood vessels can also be involved, the inferior vena cava is beaded, the lumen is narrowed with thrombosis or shedding, the fibrous tissue is wrapped and the ureter is pulled toward the midline, causing the ureter to fold, twist and pressure obstruction, causing hydronephrosis, Lateral or bilateral ureters can be affected in the entire length of the ureter, but the most common is the middle 1/3 segment, a few atypical cases can involve the psoas muscle, duodenum, colon, bladder and upper abdomen, front Area Mesenteric, bile duct, pancreas and spleen and liver and blood vessels may also be invaded, but less.
The fiber plate formed by fibrosis is fine grayish white, the boundary is unclear, and there is no envelope. The thickness varies from 2 to 6 cm. Under the microscope, there are mainly different degrees of inflammatory reaction changes. Early manifestations of chronic periarteritis, fat lobule around the aorta Peripheral multifocal adipocytes degeneration and necrosis, fat cell disintegration disappears, free fat and cholesterol crystals can appear in the interstitial, followed by a large number of lymphocytes, plasma cells, monocytes, eosinophils and macrophage infiltration, there are In the case of the plasma cells, there are Rousseau bodies, and the inflammatory cells in the metaphase are reduced. There are more fibroblasts around the adipose tissue necrosis, collagen fibers and capillary proliferation, forming granulation tissue and gradually absorbing the necrotic tissue, fibroblasts and Collagen bundles still contain lymphocytes, plasma cells, monocytes, etc., but often lack neutrophils, tissues are filled with small blood vessels, late inflammatory cells, fibroblasts and new blood vessels disappear, granuloma formation And machined, and formed a large number of dense fiber scars, there are glassy changes and calcification, inflammation is greatly reduced, only See lymphatic infiltration around the perivascular, the above different pathological changes can exist in some cases (Figure 1).
Malignant retroperitoneal fibrosis is characterized by inflammatory infiltration and scattered malignant cell nests. Malignant cells are often well differentiated and present with low malignancy.
The aorta has severe pathological changes of atherosclerosis. In some cases, the aorta is chronically inflammatory. There is chronic inflammatory cell infiltration in the aortic wall. In a few cases, chronic active arteritis can occur in the middle arteries. It is characterized by arteritis, changes similar to nodular arteritis, large veins can be affected, thickening of the intima, and even blockage, venules can also be affected, inflammatory cells infiltrate, followed by fibrosis and occlusion, aorta The surrounding lymphatic vessels may also be occluded. The muscular layer of the ureteral wall is separated by fibrotic lesions. Although it is still unobstructed, it often has edema and lymphatic infiltration under the mucosa.
Prevention
Retroperitoneal fibrosis prevention
In addition to immune factors, certain drugs (such as methyl ergots, various anesthetics, painkillers, etc.) are also the cause of the disease, therefore, effective prevention should be targeted for the cause.
Complication
Retroperitoneal fibrosis complications Complications, high blood pressure, headache
1. Due to fibrosis, the posterior peritoneal or mesenteric lymphatic drainage is blocked, causing protein-losing enteropathy or malabsorption.
2. Causes high blood pressure and high blood pressure headache due to renal obstruction.
Symptom
Retroperitoneal fibrosis symptoms Common symptoms Back pain Lower abdominal pain Fatigue Low heat pain Anorexia nausea
The disease can occur at any age, but it is more common in people aged 40-60 years, accounting for 2/3. The incidence of males is more common, which is 2 to 3 times that of females. It is clinically divided into early stage, active stage and fiber plate. Systolic phase 3.
1. Pain can be asymptomatic at first, and pain can occur later. It occurs mostly in the lower back or lower back and radiates to the lower abdomen. The groin area, the anterior medial part of the external genital or thigh, the pain is blunt pain, starting with one side, with Symptoms can develop bilateral pain.
2. Subacute inflammatory manifestations include abdominal pain, tenderness in the kidney, hypothermia, increased white blood cell count, increased erythrocyte sedimentation rate and fatigue, anorexia, nausea and vomiting, and weight loss.
3. Abdominal mass About 1/3 of patients can reach the mass in the lower abdomen or pelvic cavity.
4. Patients with compression symptoms 75% to 80% have partial or complete obstruction of the ureter, such as hydronephrosis, urinary tract irritation, oliguria or anuria, chronic renal failure and azotemia, etc., compression of lymphatic vessels And the inferior vena cava can cause edema of the lower extremities, but it is rare, occasionally the intestinal obstruction occurs when the small intestine or colon is compressed.
Intravenous pyelography is the most diagnostic method and can be expressed as a typical triad:
1 hydronephrosis accompanied by upper ureteral dilation,
2 the ureter is displaced to the center,
3 The ureter is affected by external compression, and the late kidneys are not developed.
Examine
Retroperitoneal fibrosis
1. Blood routine There may be red blood cells, hemoglobin is reduced; eosinophils are elevated, and hematocrit is less than 33%.
2. One third of patients with urine routine have proteinuria.
3. ESR was 94% of patients with initial increase in erythrocyte sedimentation rate.
4. Renal function Clinically, 75% of patients have varying degrees of renal dysfunction, manifested as oliguria, azotemia, such as serum creatinine, elevated urea nitrogen.
5. Alkaline phosphatase In recent years, alkaline phosphatase is considered to be a marker of the disease, and elevated alkaline phosphatase is important for the diagnosis of this disease.
6. Ultrasound examination This test is non-invasive, non-radioactive, cheap and convenient, and can be used as one of the screening and diagnosis methods for the disease.
(1) B-ultrasound: retroperitoneal fibrotic plaque can be found, suggesting the degree of hydronephrosis and ureteral hydrops, and can exclude common causes such as stones that cause hydronephrosis.
The typical ultrasonographic features of retroperitoneal fibrosis are characterized by a clear echogenic mass from the level of the bilateral renal arteries to the anterior border of the lower lumbar vertebrae or humerus. The internal echo is relatively uniform, and the anterior and bilateral sides of the abdominal aorta are lamellae. Around the abdominal aorta wall, there is sometimes a strong echo of calcified plaque. The border of the lesion is relatively clear, and the posterior border is inseparable from the anterior wall of the abdominal aorta. Both sides are in contact with the posterior wall of the posterior peritoneal cavity and are not affected by intestinal gas. Good, tired of pyelone and ureteral dilatation above the ureter, early retroperitoneal fibrosis, due to mild changes and by the influence of intestinal gas or intestinal fluid is easily missed.
(2) Color Doppler: The blood flow signals of the abdominal aorta and the iliac vessels can be observed and the stenosis and stenosis degree can be determined.
(3) Ultrasound identification: attention should be paid to the differentiation of abdominal aortic aneurysm with thrombosis and retroperitoneal malignancy.
1 Identification of abdominal aortic aneurysm with thrombosis: retroperitoneal fibrosis of the abdominal aorta is clear and flat, there may be calcification, low echo is mostly located in front of and on both sides of the abdominal aorta, the range is large, it is difficult to explore the boundary The abdominal aortic aneurysm is characterized by a fusiform bulging of the arterial wall, the intima is not smooth, and the hypoechoic echo is located in the wall of the tube and is irregular, which can detect the boundary of the aneurysm.
2 Identification of retroperitoneal malignant tumors: retroperitoneal fibrosis is mainly distributed in front of and on both sides of the aorta. The mass of the tumor is extensive, the boundary is unclear, but it is non-fused or lobulated, and the internal echo is relatively uniform, rarely causing the main Arterial shift, no mesenteric lymph node metastasis and abdominal cavity implantation.
7. X-ray inspection
(1) intravenous urography (IVU): Because the most common symptom of this disease is caused by compression of the ureter, once the disease is suspected, intravenous urography should be selected. It has been reported in the literature that more than 90% of patients can show abnormalities. Two-thirds of adult cases and two-thirds of children with bilateral ureteral involvement (Figure 2) are the most diagnostic methods.
1 Image features: The typical sign of intravenous urography is the "triple sign."
A. Hydronephrosis with upper ureteral dilatation distortion.
B. The ureter is displaced to the center.
C. The ureter is affected by external compression, and the late kidneys are not developed.
2 image identification: primary ureteral tumor, ureteral lymphadenopathy, ureteral or inflammatory stenosis patients with intravenous urography may have similar signs, should be identified.
In a few cases, when the fibrosis range is extensively involved in the pelvic cavity, the bladder may have a teardrop shape due to annular compression. It should be associated with pelvic hyperlipidemia, pelvic hematoma, bilateral pelvic lymphadenopathy, and pelvic side after inferior vena cava occlusion. The vascular formation is differentiated.
(2) angiography:
1 Inferior vena cava angiography: It can show that the inferior vena cava segment of the lumbosacral region is smooth and gradually narrow, and in a few cases, the inferior vena cava can be completely obstructed.
2 aortic angiography: the affected aorta and the common iliac artery can show smooth or irregular stenosis changes.
(3) lymphangiography: the lymphatic vessels are dilated, the distortion is changed, and the contrast agent is delayed by the aortic lymph node emptying, but sometimes lymphangiography may be normal.
(4) Digestive tract barium angiography: When the digestive tract is involved, it can show that the external pressure of the lumen is gradually narrowed. When the rectum and sigmoid colon are compressed, it should be differentiated from pelvic hyperlipidemia and radiation enteritis (Fig. 3).
(5) CT scan: CT can not only understand the extent of retroperitoneal fibrosis, but also can detect obvious lesions before urinary tract obstruction, which is one of the main means of diagnosis and follow-up of this disease.
1 Image features: CT findings of retroperitoneal fibrosis are various, usually manifested as single or multiple uniform density of soft tissue mass, the leading edge is clear and the trailing edge is unclear, wrapping the aorta and inferior vena cava, from The renal ventricle to the humeral condyle surrounds the ureter and has varying degrees of hydronephrosis. The mass does not only extend in front of the aorta, but also causes occlusion of the fat pad between the mass and the nearby psoas muscle. Early retroperitoneal Fibrotic angiogenesis is active, and plate blood supply is abundant. Therefore, after intravenous injection of contrast agent, the mass is obviously strengthened, and in the late stage, the degree of enhancement is very weak. It should be noted that CT can be found in a few cases (Fig. 4).
2 image identification: CT value of retroperitoneal fibrosis is similar to muscle or substantial organ density, and it is not easy to distinguish from new organisms or swollen lymph node mass on CT. Therefore, attention should be paid to the following diseases:
A. Lymphoma, primary sarcoma and other malignant metastases: There is a characteristic strip-like shadow in the retroperitoneal fibrotic mass, which may be calcified. The lesion does not penetrate the peritoneum and does not produce local bone destruction. For the adjacent aorta, the inferior vena cava tends to be wrapped around rather than displaced, and the malignant tumors that metastasize to the retroperitoneum are mostly aortic and vena cava lumps, lymphomas, primary sarcomas and Other malignant lymphadenopathy often raises the aorta away from the vertebral body.
B. Aneurysm: Although the fibrosis around the aneurysm is also enhanced, the surrounding tissue around the aorta is similar to the retroperitoneal fibrosis, but the fiber-wound aorta expands like a tumor.
C. Other diseases: such as amyloidosis, retroperitoneal hematoma, cervical cancer, pancreatic cancer, etc.
8. Magnetic Resonance Imaging (MRI) Compared with CT , the advantages of MRI can not only show the shape of the mass formed by retroperitoneal fibrosis, but also show the degree of vascular stenosis and the normal hardening area on CT, which can pass through the blood vessels. The phenomenon of airflow is used to determine the relationship between the mass and these large blood vessels. In addition, its T2-weighted image can provide a basis for identifying the benign and malignant lesions. Arrive et al believe that the increase of T2 signal intensity is important for the diagnosis of malignancy. There was no significant difference in upper, benign, and malignant retroperitoneal fibrosis. Both benign retroperitoneal fibrosis and malignant retroperitoneal fibrosis showed low-to-medium signal intensity, but the masses formed by benign fibrosis were in T1 and T2-weighted images. Both of them showed uniform low signal intensity, sharp edges, and the mass formed by malignant retroperitoneal fibrosis was characterized by a high signal with uneven density and a blurred edge (Fig. 5).
9. Radionuclide scanning Hillebrand et al reported that 67 cases of retroperitoneal fibrosis were scanned by 67Ga citrate scintigraphy. Compared with CT, MRI can better reflect the severity and activity of lesions in retroperitoneal fibrotic diseases.
10. Positron emission tomography (PET) has a positive effect on the differential diagnosis of benign and malignant lesions. Kubota et al reported that positron emission tomography showed radioactivity of lumps/muscles in retroperitoneal fibrotic lesions. The ratio is slightly elevated, and the proportion of malignant lymph node diseases is significantly increased.
Diagnosis
Diagnostic diagnosis of retroperitoneal fibrosis
Diagnostic criteria
The disease lacks specific clinical manifestations, and it is easily misdiagnosed in the early stage. The diagnosis is often made several months or even years after the appearance of some vague symptoms. Patients often have extensive fibrosis after the retroperitoneum, and hydronephrosis or kidney occurs in the ureter and large blood vessels. When the function is incomplete, the doctor will be treated, and if the treatment is delayed, when there is unexplained middle and lower abdominal pain, low back pain, renal pelvis, ureteral hydrops or impaired renal function, the possibility of the disease should be considered, and the imaging examination should be carried out in time. In the early diagnosis, the diagnosis depends on the histopathological examination. CT-guided fine needle aspiration has been used to diagnose the success of the disease. Laparoscopic biopsy or laparotomy can also be performed.
In addition, there are two points to note when diagnosing this disease:
1. Whether it is a local manifestation of systemic sclerosis, retroperitoneal fibrosis can be part of systemic sclerosis, 8% to 15% of patients are accompanied by fibrosis and related diseases in other parts, such as: pelvic fibrosis, Contracture mesenteric inflammation, Riedel thyroiditis, fibrous pseudotumor after sacral, sclerosing cholangitis, mediastinal fibrosis, etc.
2. Whether it is benign retroperitoneal fibrosis or malignant retroperitoneal fibrosis. Combined with the imaging features and histopathological examination described above, benign and malignant lesions can generally be identified. It should be noted that biopsy should be more clinically linked. According to the history and surgery, the tissue should be cut at several different sites, and should be cut slightly to determine whether it is benign retroperitoneal fibrosis or malignant retroperitoneal fibrosis, and exclude other malignant tumors (such as malignant lymphoma, metastatic carcinoma). Etc.) Otherwise, even histopathological examination may be misdiagnosed or missed.
Differential diagnosis
1. Identification of diseases associated with susceptible organs or tissues
(1) ureteral disease: this disease and ureteral tumor, inflammatory stenosis can cause renal pelvis and ureteral water, should pay attention to the identification of the two.
(2) Pancreatic cancer: retroperitoneal fibrosis involving and leading to occlusion of fat pad around the pancreas is often misdiagnosed as pancreatic cancer, attention should be paid to their clinical and imaging characteristics.
(3) common bile duct disease or sclerosing cholangitis: the disease involving the common bile duct can cause jaundice and other manifestations, should pay attention to exclude biliary tract caused by diseases such as common bile duct disease or sclerosing cholangitis, but retroperitoneal fibrosis can be combined with sclerosing bile duct Yan is an integral part of systemic sclerosis, and it is necessary to think about the possibility of both being present.
(4) knot, rectal disease: retroperitoneal fibrosis involving the knot, rectal, patients may have diarrhea, constipation, and even obstructive symptoms, easily misdiagnosed as a knot, rectal tumor or inflammatory disease, and the two can be mutually causal, clinical Patients with diarrhea, constipation, and even obstruction should consider the possibility of retroperitoneal fibrosis after excluding the disease of the intestine itself.
(5) Chronic incomplete obstruction and dysfunction of the small intestine: This disease can cause chronic obstruction and motility disorder of the small intestine after involving the mesentery. It is often misdiagnosed as chronic incomplete obstruction or dysfunction of the small intestine. Therefore, when the cause of chronic intestinal insufficiency is unknown, This disease should be thought of when obstruction or dysfunction.
2. Identification of certain primary diseases following the retroperitoneum
Such as retroperitoneal yellow granuloma, retroperitoneal hematoma, primary retroperitoneal tumors (including liposarcoma, fibrosarcoma, malignant lymphoma, fibroids, lymphangioma, leiomyoma, etc.) retroperitoneal amyloidosis.
3. Identification of retroperitoneal malignant metastases
In general, retroperitoneal malignant metastases can be identified on the outside of the ureter.
4. Identification of aneurysms
Aortic aneurysm or aortic aneurysm can form a fibrotic ring around the aneurysm or lateral growth and cause ureteral obstruction. Imaging shows that the wrapped aorta is tumor-like dilatation, and retroperitoneal fibrosis The affected aorta and common iliac artery showed smooth, irregular stenosis changes.
