Portal vein thrombosis after splenectomy for hereditary stomatocytosis in childhood

The cation-leaky hereditary stomatocytosis syndromes: A tale of six proteins

This review concerns a series of dominantly inherited haemolytic anaemias in which the membrane of the erythrocyte 'leaks' the univalent cations, compromising the osmotic stability of the cell. The majority of the conditions are explained by mutations in one of six genes, coding for multispanning membrane proteins of different structure and function. These are: RhAG, coding for an ammonium carrier; SLC4A1, coding for the band 3 anion exchanger; PIEZO1, coding for a mechanosensitive cation channel; GLUT1, coding for a glucose transporter; KCNN4, coding for an internal-calcium-activated potassium channel; and ABCB6, coding for a porphyrin transporter. This review describes the five clinical syndromes associated with genetic defects in these genes and their variable genotype/phenotype relationships.

Confounding factors in the diagnosis and clinical course of rare congenital hemolytic anemias

Congenital hemolytic anemias (CHAs) comprise defects of the erythrocyte membrane proteins and of red blood cell enzymes metabolism, along with alterations of erythropoiesis. These rare and heterogeneous conditions may generate several difficulties from the diagnostic point of view. Membrane defects include hereditary spherocytosis and elliptocytosis, and the group of hereditary stomatocytosis; glucose-6-phosphate dehydrogenase and pyruvate kinase, are the most common enzyme deficiencies. Among ultra-rare forms, it is worth reminding other enzyme defects (glucosephosphate isomerase, phosphofructokinase, adenylate kinase, triosephosphate isomerase, phosphoglycerate kinase, hexokinase, and pyrimidine 5′-nucleotidase), and congenital dyserythropoietic anemias. Family history, clinical findings (anemia, hemolysis, splenomegaly, gallstones, and iron overload), red cells morphology, and biochemical tests are well recognized diagnostic tools. Molecular findings are increasingly used, particularly in recessive and de novo cases, and may be fundamental in unraveling the diagnosis. Notably, several confounders may further challenge the diagnostic workup, including concomitant blood loss, nutrients deficiency, alterations of hemolytic markers due to other causes (alloimmunization, infectious agents, rare metabolic disorders), coexistence of other hemolytic disorders (autoimmune hemolytic anemia, paroxysmal nocturnal hemoglobinuria, etc.). Additional factors to be considered are the possible association with bone marrow, renal or hepatic diseases, other causes of iron overload (hereditary hemochromatosis, hemoglobinopathies, metabolic diseases), and the presence of extra-hematological signs/symptoms. In this review we provide some instructive clinical vignettes that highlight the difficulties and confounders encountered in the diagnosis and clinical management of CHAs.

Congenital Hemolytic Anemias: Is There a Role for the Immune System?

Congenital hemolytic anemias (CHAs) are a heterogeneous group of rare hereditary conditions including defects of erythrocyte membrane proteins, red cell enzymes, and disorders due to defective erythropoiesis. They are characterized by variable degree of anemia, chronic extravascular hemolysis, reduced erythrocyte life span, splenomegaly, jaundice, biliary lithiasis, and iron overload. Although few data are reported on the role of the immune system in CHAs, several immune-mediated mechanisms may be involved in the pathogenesis of these rare diseases. We reported in ~60% of patients with hereditary spherocytosis (HS), the presence of naturally-occurring autoantibodies (NAbs) directed against different membrane proteins (α- and β-spectrin, band 3, and dematin). Positive HS subjects showed a more hemolytic pattern and NAbs were more evident in aged erythrocytes. The latter is in line with the function of NAbs in the opsonization of damaged/senescent erythrocytes and their consequent removal in the spleen. Splenectomy, usually performed to reduce erythrocyte catheresis and improve Hb levels, has different efficacy in various CHAs. Median Hb increase is 3 g/dL in HS, 1.6–1.8 g/dL in pyruvate kinase deficiency (PKD), and 1 g/dL in congenital dyserythropoietic anemias (CDA) type II. Consistently with clinical severity, splenectomy is performed in 20% of HS, 45% of CDAII, and in 60% of PKD patients. Importantly, sepsis and thrombotic events have been registered, particularly in PKD with a frequency of ~7% for both. Furthermore, we analyzed the role of pro-inflammatory cytokines and found that interleukin 10 and interferon γ, and to a lesser extent interleukin 6, were increased in all CHAs compared with controls. Moreover, CDAII and enzymatic defects showed increased tumor necrosis factor-α and reduced interleukin 17. Finally, we reported that iron overload occurred in 31% of patients with membrane defects, in ~60% of CDAII cases, and in up to 82% of PKD patients (defined by MRI liver iron concentration >4 mg Fe/gdw). Hepcidin was slightly increased in CHAs compared with controls and positively correlated with ferritin and with the inflammatory cytokines interleukin 6 and interferon γ. Overall the results suggest the existence of a vicious circle between chronic hemolysis, inflammatory response, bone marrow dyserythropoiesis, and iron overload.

Splenectomy in childhood for non-malignant haematologic disorders - long-term follow-up shows minimal adverse effects

Splenectomy is considered therapeutic in various non-malignant haematologic diseases. Adverse events - specifically infections and thromboembolism - are not extensively documented in the paediatric population, maintaining the concern over risks-versus-benefits of the procedure. We studied a cohort of paediatric haematology patients undergoing splenectomy between 1977 and 2015 to determine short- and long-term complications. We summarised all the patients of the haematology clinic in our major Israeli tertiary centre undergoing splenectomy for therapeutic reasons, capturing infectious and thromboembolic events. The data of 103 patients, comprising 1657 follow-up years, were analysed. The cohort included 33 patients with transfusion-dependent thalassaemia, seven with non-transfusion-dependent thalassaemia, four with sickle-thalassaemia, 41 with hereditary spherocytosis, and 18 with immune thrombocytopenia. Standard presplenectomy vaccinations were noted in most. No typical cases of overwhelming postsplenectomy infection (OPSI) were identified, nor were typical OPSI bacteria isolated. Thalassaemics with central lines were most prone to infection and thrombosis. Beyond this subgroup, thrombotic events were anecdotal. This is the largest study to date to comprehensively analyse infectious and thrombotic complications of childhood splenectomy for the treatment of haematologic diseases. The use of splenectomy appears to be a relatively safe therapeutic option in paediatric patients with proper preoperative vaccination and follow-up care; use of central venous lines or catheters increase the risk in thalassaemic patients and should be avoided if possible.

Dehydrated hereditary stomatocytosis: clinical perspectives

Dehydrated hereditary stomatocytosis (DHSt) is a nonimmune congenital hemolytic disorder characterized by red blood cell (RBC) dehydration and lysis. It has been a recognized diagnostic entity for almost 50 years, and autosomal dominant inheritance has long been suspected, but it was not until 2011 that the first genetic alterations were identified. The current study reviews 73 articles published during 1971–2019 and focuses on clinical perspectives of the disease. All but one of the published clinical data in DHSt were either single case reports or case series. From these, it can be seen that patients with DHSt often have fully or partially compensated hemolysis with few symptoms. Despite this, iron overload is an almost universal finding even in patients without or with only sporadic blood transfusions, and this may lead to organ dysfunction. Other severe complications, such as thrombosis and perinatal fluid effusions unrelated to fetal hemoglobin concentration, may also occur. No specific treatment for symptomatic hemolysis exists, and splenectomy should be avoided as it seems to aggravate the risk of thrombosis. Recently, treatment with senicapoc has shown activity against RBC dehydration in vitro; however, it is not known if this translates into relevant clinical effects. In conclusion, despite recent advances in the understanding of pathophysiology in DHSt, options for clinical management have not improved. Entering data into international registries has the potential to fill gaps in knowledge and eventually care of these rare patients.

Clinical and biological features in PIEZO1-hereditary xerocytosis and Gardos channelopathy: a retrospective series of 126 patients

We describe the clinical, hematologic and genetic characteristics of a retrospective series of 126 subjects from 64 families with hereditary xerocytosis. Twelve patients from six families carried a KCNN4 mutation, five had the recurrent p.Arg352His mutation and one had a new deletion at the exon 7-intron 7 junction. Forty-nine families carried a PIEZO1 mutation, which was a known recurrent mutation in only one-third of the cases and private sequence variation in others; 12 new probably pathogenic missense mutations were identified. The two dominant features leading to diagnosis were hemolysis that persisted after splenectomy and hyperferritinemia, with an inconstant correlation with liver iron content assessed by magnetic resonance imaging. PIEZO1-hereditary xerocytosis was characterized by compensated hemolysis in most cases, perinatal edema of heterogeneous severity in more than 20% of families and a major risk of post-splenectomy thrombotic events, including a high frequency of portal thrombosis. In KCNN4-related disease, the main symptoms were more severe anemia, hemolysis and iron overload, with no clear sign of red cell dehydration; therefore, this disorder would be better described as a ‘Gardos channelopathy’. These data on the largest series to date indicate that PIEZO1-hereditary xerocytosis and Gardos channelopathy are not the same disease although they share hemolysis, a high rate of iron overload and inefficient splenectomy. They demonstrate the high variability in clinical expression as well as genetic bases of PIEZO1-hereditary xerocytosis. These results will help to improve the diagnosis of hereditary xerocytosis and to provide recommendations on the clinical management in terms of splenectomy, iron overload and pregnancy follow-up.

Thrombocytosis and portal vein thrombosis after splenectomy for paediatric haemolytic disorders: How should they be managed?

Splenectomy is indicated in selected children with haemolytic anaemia. Postoperatively, thrombocytosis occurs in at least 80% and is one of the factors implicated in the development of acute portal venous thrombosis after splenectomy in adults. A literature review shows that children are also at risk of this complication, but the incidence is low. The risk is greatest in those with particularly large spleens. Laparoscopic splenectomy does not reduce the risk of this complication. Early detection and anticoagulation usually leads to successful resolution of the thrombosis and can mitigate the risk of developing cavernous transformation of the portal vein and chronic portal hypertension. Any child with severe or unexplained postoperative abdominal pain, fever and/or vomiting after splenectomy demands urgent abdominal imaging to exclude this complication. In asymptomatic individuals, a routine Doppler ultrasound scan 1 week postoperatively is advisable if they had a particularly large spleen, longer than usual duration of surgery and/or have a marked postoperative thrombocytosis. There is no evidence for routine administration of antiplatelet drugs and/or subcutaneous heparin prophylaxis in children after splenectomy, including those who develop postoperative thrombocytosis, but children with particularly large spleens may be a subset that benefit.

Recommendations regarding splenectomy in hereditary hemolytic anemias

Hereditary hemolytic anemias are a group of disorders with a variety of causes, including red cell membrane defects, red blood cell enzyme disorders, congenital dyserythropoietic anemias, thalassemia syndromes and hemoglobinopathies. As damaged red blood cells passing through the red pulp of the spleen are removed by splenic macrophages, splenectomy is one possible therapeutic approach to the management of severely affected patients. However, except for hereditary spherocytosis for which the effectiveness of splenectomy has been well documented, the efficacy of splenectomy in other anemias within this group has yet to be determined and there are concerns regarding short- and long-term infectious and thrombotic complications. In light of the priorities identified by the European Hematology Association Roadmap we generated specific recommendations for each disorder, except thalassemia syndromes for which there are other, recent guidelines. Our recommendations are intended to enable clinicians to achieve better informed decisions on disease management by splenectomy, on the type of splenectomy and the possible consequences. As no randomized clinical trials, case control or cohort studies regarding splenectomy in these disorders were found in the literature, recommendations for each disease were based on expert opinion and were subsequently critically revised and modified by the Splenectomy in Rare Anemias Study Group, which includes hematologists caring for both adults and children.

Alterations in the Coagulation System during Major Visceral Surgery in Children

Purpose. The description of the alterations in the hemostatic system in children undergoing abdominal surgery is sparse. Enhanced clinical outcomes for previously untreatable conditions have led to an increased incidence of venous thromboembolic complications. Alterations in children's coagulation system during major abdominal operations compared to minor procedures were examined. Methods. Children (0–12 years) undergoing either laparotomy, thoracotomy, or minor surgery were included. Participants were divided into two groups: group 1 was open laparotomy including operations for solid abdominal tumours and thoracotomy, while group 2 was minor surgery. Activated partial thromboplastin time (aPTT), D-dimer, INR, and fibrinogen were measured. Results. Both groups had a shorter aPTT, higher INR, and lower fibrinogen concentrations after the operation, while D-dimer was unaltered. The changes were, however, discrete and probably not clinically significant. On day 3, all parameters except aPTT in group 1 (not measured in group 2) indicated a continuous coagulation activity. Conclusion. The tendency for coagulation activity altered based on the length and degree of surgery. A continuously altered activity was observed compatible with the reported increased risk of venous thromboembolism at day 3. However, before introducing thromboprophylaxis guidelines larger series of multicentre studies are needed.

Vascular complications after splenectomy for hematologic disorders

The most widely recognized long-term risk of splenectomy is overwhelming bacterial infection. More recently, thrombosis has become appreciated as another potential complication of the procedure. Because of these long-term risks, the indications for and timing of splenectomy are debated in the medical community. Accordingly, the adverse effects and benefits of splenectomy for hematologic disorders and other conditions demand further study. This comprehensive review summarizes the existing literature pertaining to vascular complications after splenectomy for hematologic conditions and attempts to define the potential pathophysiologic mechanisms involved. This complex topic encompasses diverse underlying conditions for which splenectomy is performed, diverse thrombotic complications, and multiple pathophysiologic mechanisms.

Aetiology and management of extrahepatic portal vein obstruction in children: King's College Hospital experience

OBJECTIVE

To study a single-centre experience of the management of extrahepatic portal vein obstruction (EHPVO) in children during the last 3 decades.

MATERIALS AND METHODS

The medical records of 108 children (67 male, median age 4.75 years, range = 1 day-16.3 years) presenting with EHPVO between 1979 and 2005 were reviewed retrospectively.

RESULTS

Extended prothrombotic screening performed in 30 patients revealed low protein C activity (6 patients), low free protein S (2), and a positive lupus anticoagulant (1); factor V Leiden mutations and the JAK2V617F mutation were not identified. Associated congenital anomalies were found in 26 of the 108 children (24%). Clinical presentation included splenomegaly in 98 (91%) and ascites in 3 (3%). Elevation of liver enzymes and prolonged international normalized ratio were seen in 13 (12%) and 14 (13%) children, respectively. Haematological parameters of hypersplenism were present in 13 (12%). Bleeding occurred in 83 (77%) patients with a median age of 4.58 (0.02-16.37) years. On first endoscopy, oesophageal varices were present in 92 patients; of those subjects, 70 (76%) received sclerotherapy, 5 (5%) had band ligation, and 16 (17%) received both. Complications of endoscopy occurred in 34 (37%) patients: oesophageal ulcers in 16, oesophageal stricture in 10, both in 7, and erosive gastritis in 1. Seventeen (16%) children underwent shunt surgery for uncontrolled bleeding at a median age of 9.7 (5.2-23.7) years.

CONCLUSIONS

The aetiology of EHPVO in the majority of patients remains unknown. Sclerotherapy and banding are effective treatments for bleeding varices with good long-term outcome. Procoagulant state is an infrequent cause of EHPVO in children.

A case of portal vein thrombosis after laparoscopy-assisted splenectomy and cholecystectomy in a child

We report the case of an 8-year-old boy with a red cell membrane disorder who developed, soon after undergoing laparoscopic cholecystectomy and splenectomy, complete thrombosis of the right branch and a partial occlusion of the left branch of the portal vein. The child was affected by a right hemiparesis because of a hypoxic-ischemic disorder that occurred in the first hours of life and was heterozygous for the methylenetetrahydrofolate reductase gene mutation 677C-T. Intravenous heparin and aspirin were initiated on postoperative day 7. Heparin treatment was switched to the subcutaneous route after the first 24 hours. The symptoms subsided 3 days after the beginning of treatment, whereas complete resolution of portal vein thrombosis was observed 2 months later. A review of the literature is reported, and the possible pathogenetic mechanisms underlying portal vein thrombosis are discussed.

Portal vein thrombosis after splenectomy in pediatric hematologic disease: risk factors, clinical features, and outcome

BACKGROUND/PURPOSE

A retrospective study was performed to evaluate risk factors, clinical features, and treatment modalities of portal vein thrombosis (PVT) after splenectomy in pediatric hematologic disease.

METHODS

Sixty-eight patients who underwent splenectomy for various hematologic diseases were evaluated with regard to age, sex, blood count, and splenic mass. Patients who developed PVT were also reviewed for clinical features, treatment modalities, and outcome.

RESULTS

Patients with PVT (n = 4, 5.88%) and without PVT (n = 64, 94.2%) had a mean age and female/male ratio of 13.2 years (range, 10-16 years) and 4:0, and 10.2 years (range, 1-16 years) and 29:35, respectively. Postoperative thrombocyte levels and splenic mass with and without PVT was 804 x 10(3)/mm(3) and 752.5 g, and 465.2 x 10(3)/mm(3) and 441g, respectively. Three patients with PVT presented with abdominal pain, fever, and vomiting. The diagnosis of PVT was made by Doppler ultrasonography in all patients including the asymptomatic case. Protein C, protein S, and antithrombin III levels were mostly decreased and/or normal and di-dimer levels were increased and/or normal after the development of PVT. Antiplatelet (acetylsalicylic acid) and antithrombotic therapy (low molecular weight heparin) were treatment agents. None of the patients needed surgery. During a mean follow-up period of 55.5 months, by Doppler ultrasonography, 1 patient was found to be free of thrombosis, whereas 1 had partial thrombosis. Two patients developed cavernomatous transformation leading to portal hypertension.

CONCLUSIONS

Portal vein thrombosis is a rare but significant complication of splenectomy done for hematologic diseases. According to our results, female gender and decreased levels of coagulation inhibitors seem to be risk factors in addition to previously mentioned thrombocytosis and greater splenic mass. Doppler ultrasonography may be performed in all patients after splenectomy to screen PVT. In the presence of well-known risk factors, prophylactic antiplatelet and antithrombotic therapy should be considered after splenectomy.

Recent concepts regarding extra-hepatic portal hypertension

Extra-hepatic portal hypertension (EHPH) defined as non cirrhotic, presinusoidal and prehepatic portal hypertension, with obstruction and cavernomatous transformation of the main portal vein, entails a high, early and prolonged risk of gastro-intestinal bleeding (GIB) mainly from esophageal and/or gastric varices, and less often a risk of cholangiopathy or protein-losing enteropathy. Diagnosis of EHPH may be done with non invasive imaging techniques. Assessment of bleeding risk is based on results of endoscopic examination. Occurence of a bleeding episode or onset during follow-up of endoscopic signs of high risk of GIB require radical eradication of varices. Radical cure of EHPH is achieved at best by bypass surgery restoring a physiological portal flow, and as a second choice by shunt surgery. Endoscopic therapy has a place as first line treatment of GIB episodes, and also in a few cases with poor extrahepatic portal network contra-indicating efficient vascular surgery.

[Congenital xerocytosis]

Hereditary xerocytosis is a genetic disease inherited as an autosomal dominant trait and is a rare cause of hemolytic anemia. It is caused by abnormal erythrocyte membrane permeability: monovalent cation pump activity is increased and the Na/K pump cannot compensate for the K lost. As a consequence, xerocytes dehydrate, becoming rigid and sensitive to metabolic stress and oxidation. Morbility depends on the severity of the hemolytic anemia. Periodic episodes of jaundice are common during mild infections; most patients remain asymptomatic but experience mild-to-moderate hemolytic anemia, which is generally well compensated. The diagnostic clues are a markedly increased flow through the Na/K pump with a decrease in total intracellular cation content and subsequent red cell dehydration. Treatment is based on monitoring for eventual complications and careful observation during infections, which may worsen the anemia. Splenectomy is not useful and for some authors may even be contraindicated. The prognosis is generally very good. We report the case of a patient with episodes of hemolytic anemia during intercurrent infections and positive diagnostic tests for hereditary xerocytosis.

Portal vein thrombosis during antineoplastic chemotherapy in children: Report of five cases and review of the literature

We report five paediatric cases of portal vein thrombosis (PVT) occurring during chemotherapy, observed in two institutions over an 8-year time period. These children aged 2.5-15 years were treated for Burkitt's lymphoma, Ewing's tumour, small cell bone tumour or medulloblastoma. PVT was diagnosed on colour Doppler ultrasonography (US). In four patients, thrombosis occurred 2-45 days after severe hepatic veno-occlusive disease (HVOD) secondary to intensive chemotherapy containing busulfan. In one case, PVT occurred in the absence of HVOD in a patient with pre-existing periportal lymphomatous infiltration. Four patients experienced persistent portal hypertension, which resulted in death in one. PVT during chemotherapy in children is a rare event and appears to be closely related to intensive chemotherapy containing busulfan and to be associated with HVOD.

Pulmonary thromboendarterectomy in a case of hereditary stomatocytosis

We present a case of pulmonary thromboendarterectomy performed successfully in a patient with stomatocytosis. Stomatocytosis is a rare condition of abnormal erythrocyte morphology in which haemolysis and hyperkalaemia occur at cooler temperatures. A 35-yr-old male with stomatocytosis was referred for pulmonary thromboendarterectomy in the context of chronic thromboembolic pulmonary hypertension. He had undergone splenectomy as a child, which rendered him hypercoagulable as the spleen normally removes the haemolysed red cell fragments from blood. By constantly monitoring urine for macroscopic haematuria, arterial and mixed venous blood gas analysis perioperatively and by limiting the period of deep hypothermic circulatory arrest that is normally required for this operation, we were able to perform the operation successfully.

An extreme consequence of splenectomy in dehydrated hereditary stomatocytosis: gradual thrombo-embolic pulmonary hypertension and lung-heart transplantation

Dehydrated hereditary stomatocytosis (DHS) belongs to the heterogeneous class of hemolytic anemias with leaky red cell membranes. Splenectomy is a highly deleterious treatment, because it favors, with virtually no exception, the occurrence of thromboembolic disease. We describe here the extreme case of a patient with DHS and an associated sickle cell trait. Splenectomy was carried out due to a splenic infarction that occurred during an airplane journey. About 12 years later, the patient noticed an exertional dyspnea, which gradually worsened to such a degree that she became severely incapacitated within 5 years. Eventually, the patient developed a cor pulmonale associated with chronic thromboembolic pulmonary hypertension (CTEPH) and successfully underwent a heart-lung transplant operation. This case ranks as one of the most severe examples ever recorded of the effect that splenectomy may have in DHS patients. Nonetheless, it represents the first case to receive a heart-lung transplant.

Allogeneic bone marrow transplantation for severe post-splenectomy thrombophilic state in leaky red cell membrane haemolytic anaemia of the stomatocytosis class

The tendency for thrombosis to occur if haemolysis persists after splenectomy is especially marked in "hereditary stomatocytosis", in which the red cell membrane "leaks" Na and K. A 21-year-old woman, who was splenectomized in childhood for a congenital haemolytic state, presented with major pulmonary embolism that recurred despite anticoagulation. Tests showed a significant cation leak with a "shallow-slope" abnormality in temperature dependence. Allogeneic bone marrow transplantation caused the thrombophilic state to cease and subsequently anticoagulation was stopped without recurrence of thromboembolism. However, she died 9 months after transplantation: iron overload, intensified by the transfusion demands of the transplant, was a major factor.

Portal vein thrombosis after laparoscopy-assisted splenectomy and cholecystectomy

A 12-year-old girl underwent laparoscopy-assisted splenectomy and cholecystectomy with removal of her spleen through a small Pfannenstiel incision. She had an unremarkable postoperative course but returned 16 days later because of increasing right-sided abdominal pain. The pain was constant, sharp, and stabbing without radiation. Abdominal examination showed diffuse right upper quadrant and epigastric tenderness without peritoneal irritation. Laboratory test results included white blood cell count, 14.4 x 10(9)/mm3; hemoglobin, 8.5 g/dL; platelets, 1,483,000; and normal values for lipase, amylase, aspartate transaminase, and alanine transaminase. Evaluation with ultrasonography and vessel Doppler studies showed an occlusive thrombus throughout the portal and splenic veins. The patient underwent intravenous heparin anticoagulation therapy. Her symptoms resolved completely over the next 2 days. The patient is currently receiving warfarin and anagrelide as an outpatient (international normalized ratio, 2). There were no long-term complications caused by portal vein thrombosis. This is the first reported case of portal vein thrombosis after laparoscopic splenectomy in the pediatric population.

The diagnosis and management of hereditary spherocytosis

Hereditary spherocytosis (HS) is relatively common in Caucasian populations; most individuals have mild or only moderate disease. There is commonly a family history and a typical clinical and laboratory picture so that the diagnosis is usually easily made without additional laboratory tests. Atypical cases may require measurement of membrane proteins and molecular genetics to clarify the nature of the membrane disorder. It is particularly important to rule out stomatocytosis because splenectomy is contraindicated because of the thrombotic risk. Mild HS can be managed without folate supplements and does not require splenectomy. Moderately and severely affected individuals are likely to benefit from splenectomy, which should be performed after the age of 6 and with appropriate counselling about the risk of infection. In all cases careful dialogue between physician, child and the family is essential. Laparoscopic surgery can result in shorter hospital stay and less pain.