Partial Splenectomy for Hereditary Spherocytosis

Abstract

Source: Buesing KL, Tracy ET, Kiernan C, et al. Partial splenectomy for hereditary spherocytosis: a multi-institutional review. J Pediatr Surg. 2011; 46(1): 178– 183; doi: 10.1016/j.jpedsurg.2010.09.090Investigators from five large North American children’s hospitals reviewed the medical records of patients who underwent partial splenectomy (PS) for the treatment of hereditary spherocytosis (HS) between 1990 and 2008, to assess the efficacy and safety of this procedure. PS allows salvage of a fraction of the splenic mass (15% is the goal) in hopes of reducing the risk of overwhelming postsplenectomy sepsis (OPSS). Data pre- and postoperatively were abstracted from the records of study children including laboratory values, abdominal pain, exercise tolerance, and need for transfusion. In addition, information on subsequent completion splenectomy was reviewed and episodes of OPSS identified.Data on 62 children who underwent 24 laparoscopic PS and 38 open PS were analyzed; mean length of follow-up was 36 months. At one year following PS, mean hemoglobin values had increased in study patients by 3.0 g/dL (P<.001; n=52), and bilirubin levels decreased by 1.26 mg/dL (P<.001; n=25). Preoperative transfusion was needed in 30 of 54 patients (55.6%); postoperatively, only 4 of 54 patients (7.4%) required transfusion. Overall, abdominal pain decreased and exercise tolerance increased in study participants after PS.Clinically significant recurrence of anemia or abdominal pain occurred in about 10% of patients, and completion splenectomy was performed in 3 of 62 patients (4.8%) at a mean of nearly five years postoperatively. Some splenic regrowth was noted overall; however, children who failed to achieve a postoperative hemoglobin of at least 11.5 g/dL had anatomic evidence of increased splenic regeneration compared to those who had a good hematologic response. Preoperative hemoglobin, reticulocyte, and bilirubin levels did not predict recurrence of clinical symptoms or need for completion splenectomy.Comparison of children undergoing laparoscopic and open PS revealed few differences; those in the open group tended to have larger spleens (very large splenic size is a relative contraindication to laparoscopic splenectomy), and a larger remnant was left after laparoscopic PS. Overall, 35% of the children underwent concomitant cholecystectomy. No patients developed OPSS, and there were no deaths.The authors conclude that PS results in improvement of the hematologic abnormalities associated with HS and resolution of clinical symptoms, with a low rate (approximately 5%) of completion splenectomy, and should be considered a viable option for selected children with HS.Dr Snyder has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.Animal studies have suggested that preservation of 25% to 50% of the splenic mass is necessary to prevent OPSS.1,2 PS is intentionally designed to preserve only 15% of the splenic mass. However, the spleen is usually enlarged in HS patients, and this “corrective factor” may result in salvage of 25% of a normal-sized spleen. Whether this is sufficient to diminish or prevent OPSS (or any of the other complications) remains unknown, and will require larger series with long-term follow-up. As the data in the current study suggest, PS does appear to preserve some phagocytic function; however, the ability of PS patients to produce antipolysaccharide antibodies synthesized by a splenic B-lymphocyte subpopulation for humoral defense against encapsulated bacteria remains unknown.Complications specific to PS may become evident in larger patient populations. For example, early postoperative or delayed bleeding is a concern in patients undergoing splenic salvage procedures for trauma, with a reported incidence of approximately 1%.3 An earlier report4 from one of the institutions participating in this collaborative study demonstrated longer hospitalization times and increased postoperative pain in the laparoscopic PS cohort compared to standard laparoscopic total splenectomy. Since the current study only compared two groups of PS patients, data regarding the outcome of PS versus complete splenectomy (length of stay, time to feedings, complications) are not known.An alternative to splenectomy or PS is splenic embolization.5,6 This avoids an incision while still preserving splenic mass. However, fever and significant abdominal pain have been noted postembolization, and control of the amount of residual splenic tissue is problematic.The long-term efficacy of PS remains unclear; current evidence suggests the protection against hemolysis is persistent.7 Some reports have suggested that total splenectomy is slightly more effective, with persistence of a mild hemolytic state and increased risk of gallstone formation in patients who underwent PS.8 Moreover, PS does not appear to protect against the development of aplastic crisis. Nevertheless, PS does present a reasonable alternative to total splenectomy in children with hereditary spherocytosis.Both the benefits and risks associated with partial (or complete) splenectomy are life-long. Recommendations on how best to reduce the risk of OPSS will continue to evolve as new vaccines are developed, eg, PCV 13. Therefore there is a need for registries to facilitate long-term follow-up of these patients. Surely if the auto industry is able to recall autos for needed updates years after they are produced, the health care industry can find a way to develop such registries.