title: Predictors of response after laparoscopic splenectomy for immune thrombocytopenic purpura.
abstract: BACKGROUND
  Splenectomy has been shown to produce long term remission in patients with immune thrombocytopenic purpura (ITP). With the development of laparoscopic splenectomy, there is renewed interest in the surgical treatment of ITP. The aim of this study was to identify factors that are predictive of outcome after laparoscopic splenectomy for ITP.
  
  
  METHODS
  A case series of 67 consecutive patients with ITP undergoing laparoscopic splenectomy was reviewed. A positive response was defined as a postoperative platelet count greater than 150,000/ml requiring no maintenance medical therapy on follow-up evaluation. A chi-square test and a stepwise logistic regression analysis were performed for the following variables: age, gender, preoperative response to steroids, duration of disease, severity of preoperative bleeding, accessory spleens, and thrombocytosis on discharge.
  
  
  RESULTS
  At a median follow-up period of 38 months (range, 2-56 months), 52 patients (78%) had a positive response to laparoscopic splenectomy. Of the 15 patients (22%) who did not have a positive response, 11 were refractory and 4 relapsed. All relapses occurred in patients with a platelet count less than 150,000/microl at discharge. Patient age was the most significant predictive factor for success or failure of the operation. The median age of the responders (31 years; range, 19-71 years) was significantly lower than the median age of the nonresponders (49 years; range, 24-62; p < 0.001). Only 5.6% of those younger than 40 years did not have a positive response, compared with 42% of patients older than 40 years (p < 0.05). Patient age was significantly associated with outcome on univariable chi-square analysis (p = 0.001), and was the only significant factor on multivariable analysis (odds ratio, 2.65; 95% confidence interval, 1.71-4.1). Other significant predictors of outcome on univariable analysis were preoperative response to corticosteroids and platelet count on discharge.
  
  
  CONCLUSIONS
  A long-lasting response after splenectomy for ITP is more likely to occur in patients younger than 40 years of age. To avoid the long-term side effects of corticosteroid use, early surgical referral of younger patients with ITP should be considered.
authors.affiliation: Department of Surgery, Division of Emergency Non Trauma and Minimally Invasive Surgery, University of Southern California School of Medicine, Health Care Consultation Center 514, 1510 San Pablo Street, Los Angeles, CA 90033, USA. nkatkhouda@surgery.usc.edu
authors.forename: N
authors.initials: N
authors.lastname: Katkhouda
authors.forename: S W
authors.initials: SW
authors.lastname: Grant
authors.forename: E
authors.initials: E
authors.lastname: Mavor
authors.forename: M H
authors.initials: MH
authors.lastname: Friedlander
authors.forename: R V
authors.initials: RV
authors.lastname: Lord
authors.forename: K
authors.initials: K
authors.lastname: Achanta
authors.forename: R
authors.initials: R
authors.lastname: Essani
authors.forename: R
authors.initials: R
authors.lastname: Mason
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000601:surgery*; D013156:Splenectomy / Q000379:methods*