Right atrium and inferior vena cava leiomyoma

　　Intravenous leiomyomatosis is another rare tumor disease. The tumor originates from the uterus, or the venous wall of the uterus and pelvic cavity, and early manifestations include multiple or pelvic uterus leiomyomas involving the pelvic cavity. The tumor often protrudes into the venous channel of the uterus or pelvic cavity.

　　Right atrium and inferior vena cava leiomyoma may lead to complications such as right heart failure and inferior vena cava obstruction syndrome. Heart failure refers to a pathological condition where the heart's output of blood is insufficient to meet the metabolic needs of tissues under normal venous return. Clinically, it is characterized by insufficient cardiac output, reduced tissue blood flow, and congestion in the pulmonary and (or) systemic circulation, hence also known as congestive heart failure. The inferior vena cava obstruction syndrome is caused by partial or complete obstruction of the inferior vena cava due to invasion, compression by adjacent lesions, or intracavitary thrombosis, resulting in a series of clinical symptoms.

　　Cavernous mucoma between the right atrium and inferior vena cava occurs only in women and is more common in middle-aged women before menopause, with a history of pregnancy. When the tumor is localized to the uterus, parauterine tissue, or pelvis, the clinical manifestations are not much different from those of general uterine fibroids, such as uterine enlargement, increased menstrual flow, pelvic mass, abdominal pain, and other symptoms. If the lesions extend to the inferior vena cava and right atrium, causing circulatory obstruction and resulting in symptoms such as palpitations, shortness of breath, liver enlargement, oliguria, ascites, lower limb edema, pleural effusion, and heart murmurs, it is similar to right heart failure and is also a type of Budd-Chiari syndrome. Some patients may have no symptoms and only discover heart murmurs during physical examinations for other reasons, further ultrasound examinations to find right atrial tumors, and are diagnosed with right atrial tumors while ignoring the tumor in the inferior vena cava and pelvic and uterine lesions. Some patients may experience syncope or sudden death, often due to the movement of the tumor, impaction and obstruction in the tricuspid valve, or pulmonary artery. Many patients have a history of hysterectomy and are misdiagnosed with general uterine smooth muscle tumors, ignoring the intravascular tumor.

　　Increasing awareness and vigilance of this disease, and conducting comprehensive and in-depth examinations for suspicious patients is the key to obtaining an accurate diagnosis. For patients with multiple uterine fibroids, where the lesions involve parauterine tissue or adnexa, further examinations should be conducted to exclude this disease; if the uterus is surgically removed, careful gross and microscopic pathological examinations should be performed to differentiate whether it is this disease. For patients with right cardiac cavity tumors, especially women, a history of uterine fibroids and uterine surgery should be inquired, and gynecological examinations should be conducted; at the same time, a comprehensive examination should be conducted, and attention should be paid to whether there are tumors connected with the heart tumor in the inferior vena cava.

　　Echocardiography, abdominal B-ultrasound, CT examination, MRI examination, inferior vena cava and right atrium angiography, and other examinations are of decisive significance for the diagnosis of this disease, establishing the extent of tumor extension, tumor size, and the evaluation of the degree of circulatory obstruction, as well as the selection of surgical methods.

　　The cavernous mucoma in the inferior vena cava of the right atrium is relatively rare, but it has special clinical and pathological characteristics; this disease occurs only in women, originating from uterine and pelvic lesions, and is a chronic progressive tumor disease that can cause obstruction of the inferior vena cava and right atrium, leading to severe hemodynamic disorders. Since the lesions of this disease are benign, surgical treatment is effective and should not be mistakenly considered as metastasis of intracardiac and inferior vena cava from malignant tumors in the uterus or pelvic cavity, and surgical treatment should not be abandoned. Internists, cardiothoracic surgeons, and obstetricians and gynecologists should increase their awareness and vigilance of this disease, and conduct comprehensive and in-depth examinations for suspicious patients, which is the key to obtaining an accurate diagnosis. Early diagnosis and treatment should be carried out once the disease is diagnosed to prevent the occurrence of complications.

　　The main clinical examination methods for smooth muscle tumors of the right atrium and inferior vena cava are echocardiography, esophageal ultrasound, infrapubic inferior vena cava angiography, CT examination, and magnetic resonance examination.

　　1. Echocardiography:It can clearly determine whether there is a mass in the right heart chamber, the location of the mass, its relationship with the tricuspid valve orifice, pulmonary artery, the displacement, size, and movement state of the mass during the cardiac cycle.

　　2. Esophageal ultrasound:It can clearly show the situation where the tumor extends from the inferior vena cava into the right atrium, and can help differentiate from other tumors, myxomas, and so on.

　　3. CT examination and magnetic resonance examination:It can reveal the location, size, obstruction range, and nature of the mass in the inferior vena cava.

　　4. Infrapubic inferior vena cava angiography:It can clearly determine the size, length, and degree of obstruction of the mass, and can provide a complete and continuous image.

　　Patients with smooth muscle tumors of the right atrium and inferior vena cava should eat light and bland foods as the main diet, pay attention to dietary regularity. It is recommended to eat high-protein, nutritious, vitamin and mineral-rich, and high-calorie and easily digestible foods. It is forbidden to eat greasy and difficult-to-digest, fried, smoked, grilled, cold, spicy, and high-salt and high-fat foods.

　　When the smooth muscle tumor of the right atrium and inferior vena cava extends to the inferior vena cava and right atrium, the lesion is long, the range is wide, and it is often multiple. If the obstruction symptoms are significant, the patient's hemodynamic disorders are severe, and multiple organ functions are impaired. Due to the obstruction of the inferior vena cava, it affects the insertion of extracorporeal circulation catheters, and surgical treatment is very difficult. The uterine and pelvic lesions of this disease are often extensive, and complete resection is also difficult, and recurrence is easy.

　　First, the principles to be followed in surgical treatment:

　　1. Before surgery, a comprehensive assessment of the patient's general condition and important organ functions should be made based on sufficient preoperative examination data, especially the size and location of the tumor in the inferior vena cava and right atrium. Careful study is required to select appropriate extracorporeal circulation methods and surgical techniques.

　　2. Since the tumor of this disease is often multiple, sometimes with multiple attachment points, it is easy to miss the lesions during resection, leading to recurrence. Therefore, careful exploration and complete resection of all lesions and their attachment points are required.

　　3. For uterine and pelvic lesions, total hysterectomy should be performed, along with the removal of ovaries and pelvic lesions, to avoid recurrence.

　　4. The surgery for this disease has a large trauma, many complications, and postoperative close monitoring and proper treatment are required to prevent and treat complications of important organs, such as low cardiac output syndrome, respiratory distress syndrome, liver and kidney dysfunction, and hemorrhage.

　　Second, surgical methods

　　1. Primary radical surgery: Applicable to patients with good general condition and mild circulatory disorders. Tracheal intubation and general anesthesia, using a combined thoracoabdominal incision from the sternal notch to the upper midline of the pubic symphysis. Expose the heart, inferior vena cava, and bilateral iliac veins. Under deep hypothermic low-flow extracorporeal circulation or circulatory arrest, incise the inferior vena cava, incise or not incise the right atrium, push the tumor into the inferior vena cava, pull out the tumor from the inferior vena cava, find the attachment point, and resect the tumor together with the vascular endothelium. Suture the incision of the inferior vena cava. After recovery, gradually warm up and wean from extracorporeal circulation. Remove the tube, neutralize heparin, and resect the uterus, adnexa, and parauterine lesions when the circulation is stable and the general condition is good. This method can completely resect the lesions in one stage, but the operation time is long, the trauma is large, and there are many postoperative complications.

　　2. Stage surgery: There are many methods of this kind, and the reports are not the same. There are reports that the right atrium is incised first under extracorporeal circulation by inserting tubes into the superior vena cava and femoral vein, and the tumor is pulled as much as possible into the right atrium for resection. This method necessarily breaks the tumor, so the length of the resected tumor should be measured, and the length and position of the remaining tumor in the inferior vena cava or iliac vein should be estimated, and then the tumor, uterus, adnexa, and parauterine lesions in the inferior vena cava or iliac vein should be resected in the second stage. There are also reports that a combined thoracoabdominal incision is made first, and the tumor inside the heart, inferior vena cava, and iliac vein is resected, and then the uterus, adnexa, and uterine lesions are resected in the second stage, and pelvic cleaning is performed.

　　3. Other surgical methods: First, resect the right atrial tumor, then use the snare of the endoscope to resect the tumor inside the inferior vena cava, avoiding simultaneous laparotomy; there are also reports that due to the tumor being mostly free in the inferior vena cava and right atrium, the tumor can be pulled out and resected by simply incising the inferior vena cava.

　　Early postoperative mechanical ventilation and circulatory support should be provided to prevent the occurrence of important complications such as low cardiac output syndrome, respiratory distress syndrome, liver and kidney dysfunction, and bleeding. Some people have found that there are estrogen receptors in the tumor cells of the right atrium, and estrogen plays an important role in the occurrence, development, and recurrence of the disease. Therefore, appropriate anti-estrogen preparations such as tamoxifen (triphenoxyamine) should be used after surgery to prevent tumor recurrence, and it also has certain therapeutic value for patients whose tumors have not been completely resected.