Data collection & evaluation

Data collection is performed through the Intercontinental Cooperative ITP Registry by its office at the Children’s Hospital Basel, Switzerland. Each patient may be registered using mail, fax, or e-mail, for address and phone/fax numbers see page 3. Patient information is handled anonymously. The evaluation of the data will be performed by the study coordinator. The results will be analyzed and discussed by the Intercontinental Cooperative ITP Study Group at regular scientific meetings.

Splenectomy Background

Prospective, multi-center international study on behalf
of the Intercontinental Childhood ITP Study Group

Splenectomy is a therapeutic tool of the management of both children and adults with chronic immune thrombocytopenic purpura (ITP). It is rarely performed in patients with acute ITP. The spleen is considered as the main organ of antiplatelet antibody production (1 , 2, 3). Moreover the splenic reticuloendothelial system is the major site of clearance of antibody coated platelets.

Splenectomy is an accepted and effective treatment of children with chronic ITP, with a lasting response rate of 60% to 88% (4, 5). Currently, there are no reliable predictors of the effect of splenectomy. Recently, Law et al reported a retrospective study of adults with ITP treated with intravenous immunoglobulins (IVIg) and subsequent splenectomy. Patients with good responses to IVIg were likely to have good responses to splenectomy, whereas patients with poor responses to IVIg were unlikely to benefit from splenectomy (6). The follow-up time of patients who responded well to splenectomy ranged from 12 months (13 of 19 patients) to 8 years. Splenectomy is often delayed in children due to risks associated with this invasive procedure. Overwhelming postsplenectomy infection caused by encapsulated organisms limits its safety and has been reported to have a mortality rate of 1.6% (7). The risk is greatest in patients younger than 5 years of age. There is a potential for spontaneous remission, which is another important reason to delay splenectomy (8).

There are many unresolved questions of the preoperative and operative management of splenectomy. The practice guidelines issued by hematologists on behalf of the American Society of Hematology identified inadequate data to make evidence-based recommendations on the appropriate indications and timing for splenectomy on when the harms of splenectomy might outweigh its potential benefits, and on appropriate preoperative management (9). The technique of splenectomy includes open and laparoscopic approaches, but, the optimal method is still debated (10, 11, 12, 13). There is a need to assess the long-term response rate of children after splenectomy and to identify predictors of splenectomy failure.

References

McMillan R; Longmire RL; Yelenosky R; Lang JE; Heath V; Craddock CG. Inmunoglobulin synthesis in vitro by splenic tissue in idiopathic thrombocytopenic purpura.
N Eno,1 J Med 1972; 286: 681-684

McMillan R; Longmire RL; Yelenosky R; Donnell RL; Armstrong S. Quantitation of platelet-binding IcG produced in vitro by spleens from patients with idiopathic thrombocytopenic purpura.
N Engl J Med 1974; 291: 812-817

Karpatkin S; Strick N; Siskind GW. Detection of splenic antiplatelet antibody synthesis in idiopathic autoimmune thrombocytopenic purpura (ATP).
Br J Haematol 1972; 23:167-176

Robb LG, Tiedeman K. Idiopathic thrombocytopenic purpura: predictors of chronic disease. Arch Dis Child 1990; 65: 502-506

Lammi AT, Lovric VA. Idiopathic thrombocytopenic purpura: an epidemilogic study. J Pediatr 1973; 83: 31-36

Law C, Marcaccio M, Tam P, Heddle N, Kelton JG 1997; 336: 1494-1498

Holdsworth RJ, Irving AD, Cuschieri A. Postsplenectomy sepsis and its mortality rate: actual versus perceived risks. Br J Surg 1991; 78: 1031-1038

Walker RW, Walker W. Idiopathic thrombocytopenia, initial illness and Ion-term follow-up. Arch Dis Child 1984; 59: 316-322

George JN, Woolf SH, Raskob GE, Wasser JS, Aledort LM, Ballem PJ, Blanchette VS, Bussel JB, Cines DB, Kelton JG, Lichtin AE, McMillan R,
Okerbloom JA, Regan DH, Warrier I. Idiopathic thrombocytopenic purpura: a practice guideline developed by explicit methods for the American Society of Hematology.
Blood 1996; 88: 3-40

Yoshida K; Yamazaki Y; Mizuno R; Yamadera H; Hara A; Yoshizawa J; Kanai M. Laparoscopic splenectomy in children: preliminary results and
comparison with the open technique. Surg Endosc 1995; 9: 1279-1282

Fitzgerald PG; Langer JC; Cameron BH; Park AE; Marcaccio MJ; Walton JM; Skinner MA. Pediatric laparoscopic splenectomy using the lateral
approach. Surg Endosc 1996; 10: 859-861

Wamer BW. Laparoscopic versus open splenectomy: How clear is the choice? J Pediatr 1997; 1 31: 6-7

Farah RA, Rogers ZR, Thompson WR, Hicks BA, Guzzetta PC, Buchanan GR. Comparison of laparoscopic and open splenectomy in children with hematologic disorders.
J Pediatr 1997; 131: 41-46