Hematologic diseases and splenectomy
The spleen has hematopoietic functions and is involved in part of the immune response. Diseases of the hematopoietic system are often associated with splenomegaly and hypersplenism. Because of functional or structural defects or because of the influence of antibodies, blood cells or tangible fractions of the blood are often destroyed in the spleen. Since splenectomy can treat or alleviate hematopoietic disorders, the indication of splenectomy for hematopoietic disorders, its preoperative preparation and postoperative management are of common interest to surgeons and hematologists.
I. Immune thrombocytopenic purpura (ITP) used to be called
Idiopathic thrombocytopenic purpura. The main manifestation is persistent thrombocytopenia. The presence of anti-platelet factors in the blood leads to massive destruction of platelets in the reticuloendothelial system of the body. This anti-platelet factor is, overwhelmingly, IgG associated with platelet-associated antigens, but there is insufficient evidence of autoimmunity.
ITP predominates in young women, with a trend toward increased incidence in recent years and an increase in male cases.
The clinical manifestations of ITP: mainly bleeding tendencies due to thrombocytopenia such as spontaneous petechiae and petechiae, gingival and mucosal bleeding, excessive menstruation and prolonged menstruation in female patients, and excessive bleeding after trauma. Intracranial hemorrhage is very rare, but when it occurs, the consequences are serious. The patient is in good general condition except for bleeding symptoms. The bleeding tendency is related to the degree of thrombocytopenia. When the platelet count is >50×109/L, the bleeding is often post-injury; when the platelet count is <20×109/L, the possibility of spontaneous bleeding is high.
Physical examination rarely reveals an enlarged spleen. If the spleen is significantly enlarged, secondary thrombocytopenia should be excluded.
Crosby classifies the disease into two types, dry petechiae and wet petechiae, based on the condition of the petechiae. According to Crosby, patients with wet petechiae have an increased likelihood of concomitant central system hemorrhage and should therefore be treated more aggressively.
Laboratory tests focus on a markedly decreased platelet count and a normal blood cell count. Bone marrow smears show normal red and granulocyte lines and a marked increase in megakaryocytes. Anti-nuclear antibodies in the serum are rarely positive, but autoantibodies can be found in some patients.
The diagnosis of ITP must first exclude other causes of thrombocytopenia, including pharmacologic and collagen vascular diseases.
Hormonal therapy is effective in most patients, and platelets generally rise 3-7 days after administration, peaking in a few weeks, but the effect is not long-lasting, and few patients achieve complete or lasting remission, eventually requiring splenectomy.
Surgical treatment of ITP is 80-90% effective, providing durable or complete relief of clinical symptoms and removing the patient from the risk of bleeding. Complete remission after splenectomy is more likely in patients with effective hormonal therapy. Postoperatively, patients must still receive hormonal therapy for a certain period of time. In a very small number of patients who require emergency surgery for complicated visceral bleeding, the spleen should be explored intraoperatively and removed if there is splenomegaly.
There are several points to consider in estimating the prognosis of splenectomy for the treatment of ITP.
(i) Younger patients have a better prognosis than those aged >60 years;
(ii) The prognosis is better in those with shorter disease duration;
③ The prognosis of platelet count ≥500×109/L after splenectomy is better.
II. Thrombotic thrombocytopenic purpura
Thrombotic thrombocytopenic purpura (TTP), also known as Moschcowitz syndrome, is a syndrome in which the main clinical manifestation is caused by occlusion of small arteries and capillaries, with glassy deposits and aggregation of platelets and fibrin in the subendothelium and lumen of the vessels visible microscopically. The etiology of the disease is not clear, 90% of thrombotic thrombocytopenic purpura is idiopathic and can have several triggers: viral or bacterial infections, pregnancy, certain drugs (oral contraceptives, mitomycin, cyclosporine) and non-specific poisoning.
TTP predominates in the 30 years age group, more in women than in men. Clinical symptoms are similar to those of SLE and other connective tissue diseases, mainly thrombocytopenia, microvascular hemolytic anemia, fluctuating neurological abnormalities, progressive renal impairment and fever, collectively referred to as pentacam. The role of the spleen in this disease is not clear, but splenomegaly is present in approximately 20% of patients.
Diagnosis should be differentiated from hemolytic uremic syndrome, diffuse intravascular coagulation (DIC), drug reactions, immune thrombocytopenic purpura, and aplastic anemia.
The prognosis of untreated TTP is poor, with approximately 10% of patients having a natural course of disease of less than one year. Transfusion of fresh dried frozen plasma has good efficacy in most patients, with an efficiency rate of 70%-90%. Immunosuppressants are also effective as adjuvant drugs in combination with other drugs.
Splenectomy is not the treatment of choice for TTP. For refractory cases, a combination of splenectomy plus glucocorticoids and anti-platelet drugs can be considered. The mechanism of splenectomy in the treatment of thrombocytopenic purpura is not clear, but clinical trials have confirmed that splenectomy is performed in more than 70% of long-term surviving patients.
III. Hereditary spherocytosis
In hereditary spherocytosis (HS), the red blood cell membrane is abnormal; in sickle cell anemia, the structure of hemoglobin is abnormal; in thalassemia, the peptide chain of hemoglobin is abnormal. HS is the most common of the hemolytic anemias and the one most associated with surgery.
HS is a congenital familial disorder, inherited through autosomal dominant inheritance, that results in anemia due to a defect in the red blood cell membrane. This membrane abnormality causes the red blood cells to lose their elasticity, become small and spherical, and have increased osmotic fragility. When the spherical red blood cells enter the spleen, they are blocked in the splenic medulla and eventually destroyed by reticuloendothelial cells. Its incidence is 25% – 30% and is sporadic.
The clinical manifestations of the disease vary in severity depending on the degree of hemolysis, mainly symptoms of anemia and jaundice due to anemia, as well as symptoms due to cholelithiasis. Mild splenomegaly may also be present. Severe anemia requires repeated blood transfusions to maintain hemoglobin levels, while milder cases are asymptomatic in childhood and are not detected until adulthood due to cholelithiasis. Hemolytic jaundice is very common and the prevalence of pigmented cholelithiasis is high, ranging from 20% to 55%. Cholelithiasis is related to the degree of hemolysis and age, and rarely occurs before the age of 10 years.
The diagnosis of HS relies mainly on information from laboratory tests. The diagnosis is established when spherical red blood cells are seen in the peripheral blood smear. Active reticulocyte proliferation may also be seen. The erythrocyte fragility test shows increased osmotic fragility of erythrocytes, but the Coombs test is negative.
Splenectomy has a definite therapeutic effect on HS, and hemolysis ceases in almost all patients after splenectomy. However, splenectomy is contraindicated in children before the age of six because the spleen still plays an important role in the immune function of the body at this time and splenectomy may increase the risk of infection. Patients with severe anemia requiring repeated blood transfusion should be operated as early as possible because of the potential risk of regenerative crisis caused by long-term hemolysis. Ultrasound examination of the biliary tract should be routinely performed before surgery, and if gallstone disease is found, it should be treated together with surgery.
Splenectomy cannot change the shape of spherical red blood cells. After splenectomy, spherical red blood cells still exist, but they are no longer damaged in the body and can maintain normal function. After splenectomy, most patients’ anemia is corrected, hemolytic jaundice subsides, and the possibility of cholelithiasis caused by hemolysis is reduced.
Hodgkin’s disease
Hodgkin disease (HD) is a systemic disease, and splenectomy has no direct therapeutic effect on it. The main reasons for applying surgery to HD are.
(i) The onset of HD is often located at a single site and there is a constant pathway and pattern of initial dissemination;
(ii) the choice of treatment depends on the pathological staging;
③Staging according to clinical criteria is often deviated, and the preoperative staging is revised after surgery in 30% – 45% of cases;
(iv) The prognosis of the disease is related to the staging. In general, surgery is only exploratory and contributes only to clinical staging. Also, it has been reported in the literature that there is a significant improvement in patient tolerance to radiotherapy and chemotherapy after splenectomy.
However, with the further recognition of the natural course of HD, the widespread use of combination chemotherapy regimens and their success, and the fact that CT findings have become useful for clinical staging, surgical exploration for clinical staging has been used less and less often. Exploratory surgery is only performed when the results of the exploration have an impact on the treatment plan. In addition, if splenomegaly is significant or tends to increase progressively, splenectomy may relieve clinical symptoms due to splenomegaly and also help to control thrombocytopenia, while also reducing the tumor load of the diseased body.
Exploratory surgery should include.
① A comprehensive abdominal examination ;
② Splenectomy;
(iii) liver biopsy;
(iv) biopsy of the abdominal cavity and retroperitoneal lymph nodes. The surgery should be performed with a median abdominal incision to avoid excessive bleeding.
The treatment for HD is mainly combined chemotherapy. The efficacy of combination chemotherapy for each stage of HD is: 80% for stage I and IIa by radiation therapy without progression (free from progression, FFP), up to 94% for stage IIIa by MOPP (M: nitrogen mustard, O: vincristine, P: methylphenidate, P: prednisone), and up to 94% for stage IVa by MOPP or ABD (A: doxorubicin, B: bleomycin, D: doxycycline). B: bleomycin, D: methacholine) regimen resulted in approximately 80% remission. It can be seen that diagnostic exploratory surgery and splenectomy have become less and less relevant in HD.
V. Non-Hodgkin’s lymphoma
Patients with non-Hodgkin lymphoma (NHL) are older and often advanced at the time of diagnosis, so diagnostic dissection is not a strong indication. In malignant lymphoma, splenectomy is indicated only for blood suppression secondary to hypersplenism, and discomfort due to splenomegaly or splenic infarction. Since almost all patients have received chemotherapy or radiotherapy before splenectomy, the true cause of hemoglobin suppression can only be clarified after splenectomy. Red blood cells and platelets should be transfused before surgery. In progressive lymphoma (including HD and NHL), the efficacy of splenectomy can be 80-90%.
VI. Hypersplenism
Hypersplenism is a syndrome in which red blood cells, white blood cells and platelets are reduced due to various causes. Hypersplenism can be divided into primary and secondary hypersplenism.
(a) Primary hypersplenism: Primary hypersplenism refers to unexplained hypersplenism. Due to advances in diagnostics and modern medicine, some hypersplenism that used to be considered primary has now been found to have a cause. Therefore, true primary hypersplenism is becoming less and less common. The diagnosis of primary hypersplenism must exclude all other organic diseases that cause hypersplenism. Therefore, the diagnosis of this disease is an exclusionary process.
(b) Secondary hypersplenism: Secondary hypersplenism is hypersplenism caused by a group of diseases. These include infectious diseases such as malaria, typhoid fever and schistosomiasis; tumors such as lymphoma and chronic lymphocytic leukemia; and congestion such as portal hypertension caused by various causes (mainly cirrhosis). In addition, many of the aforementioned diseases of the hematopoietic system and immune hemolytic anemia, etc. also lead to different degrees of hypersplenism.
(C) Diagnostic criteria: The diagnostic criteria for hypersplenism are.
(i) Anemia, leukopenia and thrombocytopenia, which may exist separately or simultaneously. Generally, in the early stage of the disease, leukocytopenia or thrombocytopenia is more obvious, and in the late stage, all blood cells are decreased.
(ii) There is compensatory hyperplasia in the bone marrow, and on bone marrow smear, hyperplasia is seen in all three lines.
③ Splenomegaly. Generally, hypersplenism is directly proportional to splenomegaly, but in a few cases, platelets or white blood cells are already reduced in the blood picture when splenomegaly is not yet obvious.
(iv) Splenectomy is effective, and splenectomy can restore or approach normal blood counts.
(iv) Clinical manifestations: Clinical manifestations vary depending on the degree of trilineage reduction, and may include anemia, fever, recurrent infections, petechiae, petechiae, oral ulcers and splenomegaly.
(V) Treatment: Secondary hypersplenism is mainly treated for its primary disease. Most of the clinical manifestations of hypersplenism can be relieved, and splenectomy is rarely required. Once the diagnosis of primary hypersplenism is established, splenectomy should be performed with obvious efficacy. Hormonal therapy is often ineffective.
It must be emphasized that splenomegaly is not necessarily accompanied by hypersplenism, such as splenic cysts and splenic tumors; conversely, various types of hematocrit that coexist with splenomegaly are not necessarily caused by splenomegaly, and the true cause should be identified first. It is not wise to perform splenectomy when the cause is not clear.