extensive thrombosis; normal transhepatic pressures with massive debilitating splenomegaly; This case was reported in a literature article and described the occurrence of thrombosis in a 6-year-old patient who received Haemophilus influenzae type b vaccine for prophylaxis.  Co-suspect products included PNEUMOCOCCAL VACCINE (PCV13) for prophylaxis, PPSV23 PNEUMOCOCCAL VACCINE for prophylaxis, piperacillin for prophylaxis and tazobactam for prophylaxis.   The subject's past medical history included varicose veins ligation and splenomegaly. Concurrent medical conditions included portal hypertension (etiology was autoimmune hepatitis ), autoimmune hepatitis, hemorrhage, thrombocytosis,genetic predisposition to myelodysplastic-like syndrome and varicosity.   On an unknown date, the patient received Haemophilus influenzae type b vaccine at an unknown dose, PCV13 at an unknown dose, PPSV23 PNEUMOCOCCAL VACCINE at an unknown dose, piperacillin (intravenous) at an unknown dose and frequency and tazobactam (intravenous) at an unknown dose and frequency. On an unknown date, more than a week after receiving Haemophilus influenzae type b vaccine, the patient experienced thrombosis (serious criteria hospitalization, GSK medically significant and other: serious as per eporter) and splenomegaly (serious criteria hospitalization). The action taken with piperacillin was unknown. The action taken with tazobactam was unknown. On an unknown date, the outcome of the thrombosis and splenomegaly were unknown.   It was unknown if the reporter considered the thrombosis and splenomegaly to be related to Haemophilus influenzae type b vaccine.  Additional details were provided as follows: This case was reported in a literature article and described the occurrence of thrombosis in a 6-year-old female who was vaccinated with unspecified Haemophilus influenzae type B, unspecified meningococcal vaccines and unspecified pneumococcal vaccine (PCV13 followed in 1 month by PPSV23 when feasible) (manufacturer unknown for all) for prophylaxis.   The patient was a part of cohort study that aimed to determine whether Partial Splenic Embolization (PSE) was safe and effective in the pediatric population.  The study was a retrospective review of a single-center experience for all patients ages 0 to 21 who underwent PSE for the management of portal hypertension (PHTN) between January 2010 and August 2017. The study presented the experience with the use of this modality in different pediatric populations with PHTN to better understand the rationale for safe and appropriate application of this treatment. [In this study, [In this study, recommended PSE to patients with bleeding tendencies that were not optimal candidates for an open surgical shunt or repeated endoscopies. This includes the following patient populations: Patients with baseline compromised respiratory function (ie, cystic fibrosis [CF]). 2. Patients with significant synthetic dysfunction that may progress to liver failure after shunting. 3. Patients with early signs of encephalopathy that could potentially worsen with increased portal systemic shunting. 4. Patients with abnormal right heart function that could develop cardiac decompensation or shunt failure. 5. Patients deemed to be marginal candidates for repeated anesthesia. 6. Patients with splenic vein thrombosis. 7. Patients with characteristics predicting poor wound healing or other surgical complications. 8. Patients with unfavorable anatomy, increased transhepatic resistance, or elevated right heart pressures to permit mesoportal shunting (Rex shunt)]. The patient had thrombocytopenia and/or recurrent variceal bleeding.   The patient had portal hypertension, whose etiology was autoimmune hepatitis (AI). The patient also noted to have evidence of varices before PSE. For this, the patient underwent endoscopic variceal ligation (EVL) before PSE. The patient had significant splenomegaly before PSE. This patient was found to have a genetic predisposition to myelodysplastic-like syndrome and thrombocytosis. it was reported that Myelodysplastic-like syndrome has been associated with both thrombotic and hemorrhagic complications. The decision to proceed with PSE was determined by the primary hepatologist and surgeon after careful discussion with both patient and family members regarding alternative approaches. No information on patient's family history or concomitant medication was provided.   On an unspecified date, at least 2 weeks before PSE, the patient received unspecified Haemophilus influenzae type B, unspecified meningococcal vaccines and unspecified pneumococcal vaccine (PCV13 followed in 1 month by PPSV23 when feasible) (administration route and site unspecified, dosage unknown, batch number not provided for all), in order to reduce the risk of future infection by encapsulated organisms, should the procedure lead to a complication necessitating total splenectomy. The age of vaccination was not provided. It was reported that the patient received broad-spectrum intravenous antibiotic prophylaxis, typically with piperacillin/tazobactam, before the procedure to prevent infection of infarcted splenic tissue. This was continued for 5 to 7 days. On an unknown date, before PSE, the patient's platelet count was noted at 153×10E9/L and white blood cells count (WBC) was 1.4×10E9/L (normal range not provided).   On an unspecified date between January 2010 and August 2017, at least 2 weeks after vaccination, the patient underwent PSE by interventional radiology under general anesthesia via percutaneous femoral artery approach under sterile conditions utilizing guidelines based on the Spigos technique to minimize complications. At the time of PSE, the patient was not actively bleeding. Diagnostic angiographies of the celiac axis and splenic arteries were obtained to determine the target splenic arterial branches, to identify accessory branches to other tissues from the splenic artery and to determine baseline splenic volume. Abdominal sonograms with doppler analysis of hepatic and splenic vessels were performed post procedure to assess vessel patency and the degree of intra-abdominal-free fluid. Arteriograms of partial splenic embolization (PSE), pre-embolization with capillary blush demonstrated splenomegaly and post-embolization with capillary blush revealed multiple defects before and after esophageal varices.   Information regarding patient's blood transfusions was not available. The patient was admitted to hospital after PSE for further observation and management. [In this study, patients received patient-controlled analgesia for pain control and to prevent splinting and associated pulmonary complications such as atelectasis and pneumonia]. The patient underwent EVL intervention post PSE. The patient did not develop infection with encapsulated organisms. Post-PSE, the patient's platelet count was 1335×10E9/L. the antibiotics were converted to an oral regimen before hospital discharge. [In this study, criteria for hospital discharge included adequate control of abdominal pain with oral medications, adequate oral intake/hydration, and absence of post procedure infection. Magnetic resonance imaging (MRI) showed splenomegaly and postembolization with necrotic areas surrounding the spleen. Three patients demonstrated complete resolution of varices. An additional 7 patients were noted to have a decrease in variceal grade].  On an unknown date, the patient was discharged fulfilling the criteria for hospital discharge that included (adequate control of abdominal pain with oral medications), adequate oral intake/hydration, and absence of post procedure infection. The patient was followed-up in the outpatient hepatology clinic. Hematologic indices including white blood cell (WBC) and platelet counts were monitored. Imaging was repeated as indicated. The patient developed extensive thrombosis and re-admitted to hospital. The extensive thrombosis of her splenic vein, portal vein, and inferior vena-cava (IVC) at the level of the renal veins necessitating thrombectomy and urgent splenectomy 9 days after PSE. This patient had normal transhepatic pressures with massive debilitating splenomegaly. The procedure was performed for compassionate reasons and an estimated 80% of the spleen was infarcted in a single procedure. Platelet levels peaked at an astonishing 2484×E109/L in this patient after PSE necessitating chronic antiplatelet therapy.  [In this study, 7 patients required readmission after initial discharge 2 of these patients were discharged only 1 day after PSE and returned the following day with fevers and abdominal pain with an unremarkable diagnostic evaluation]. Surveillance endoscopy was also performed 3 months after PSE to evaluate for persistent varices. Splenic function appeared to be preserved during years of follow-up in patient without increased incidence of infection.  This case has been considered as serious due to hospitalization/serious per reporter. [In this study, Thrombosis included splenic vein, portal vein, and inferior vena cava at the level of the renal veins reported by the Institute.  The outcome of the event was not reported.  The author did not comment on the relationship between the event of thrombosis and Unspecified Haemophilus influenza type B vaccine, unspecified meningococcal vaccine and unspecified pneumococcal (PCV13 followed by PPSV23) vaccine. The author stated "The Centers for Disease Control and Prevention recommends immunoprophylaxis against Streptococcus pneumoniae, H influenzae and Neisseria meningitidis in all splenectomized patients. Complications of PHTN such as hypersplenism, variceal hemorrhage, and ascites can lead to significant morbidity and mortality in children. Surgical interventions include shunting or splenectomy; however, overwhelming sepsis postsplenectomy is a pressing concern. PSE addresses portal hypertension regardless of etiology as definitive therapy. Most adverse effects following PSE are expected and can be managed conservatively. In our cohort we commonly observed fever, abdominal pain, and leukocytosis without evidence of infection. Pain was effectively controlled with intravenous and oral analgesics. Nonsteroidal anti-inflammatory drugs were avoided to minimize hemorrhage. In our experience, prophylactic antibiotics and limiting splenic reduction to no greater than 70% have avoided serious morbidity and mortality. In particular, there was no significant difference in the preprocedure platelet count between patients with and without recurrent thrombocytopenia. After PSE we noted a significant increase in platelets but to a lesser degree in patients who had recurrent hypersplenism. In our patients with esophageal varices, the combination of endoscopic ligation and PSE has been successful in controlling the progression of varices and decreasing the incidence of variceal hemorrhage."  The author concluded "our study supports that PSE is a safe, effective, semi-invasive alternative to splenectomy in pediatric patients with PHTN. The combination of EVL and PSE is effective treatment for esophageal and gastric varices (not amenable to simple band ligation). Reduced splenic volume and splenic venous return effectively decreased portal flow and pressure. PSE can be successfully performed in pre- and post-transplant transplant patients, and select cirrhotic and noncirrhotic pediatric patients. PSE appears to preserve functional spleen mass and avoids postprocedure accelerated liver disease or encephalopathy. In contrast to shunting, PSE can be effective even in the setting of elevated right-sided heart pressures. Further multicenter collaborative studies with larger and varied patient populations will need to be performed to substantiate our approach and better define patient populations that would benefit most from PSE, sequential PSE or combined interventions. Liver transplantation remains the ideal intervention for anyone with significant decompensated PHTN or advanced hepatic dysfunction".  This is 1 of the 9 valid cases reported in this article.      Lab Comments: Lab test were performed on an unspecified date, The patient's hematologic indices including white blood cell (WBC) and platelet counts were monitored (result not provided). Imaging was repeated as indicated  (result not provided). Surveillance endoscopy was also performed 3 months after PSE to evaluate for persistent varices. Splenic function appeared to be preserved during years of follow-up in patient without increased incidence of infection.