Splenectomy for people with thalassaemia major or intermedia.

BACKGROUND

Thalassaemia is a genetic disorder of the haemoglobin protein in red blood cells. It has been historically classified into thalassaemia minor, intermedia and major, depending on the genetic defect and severity of the disease. The clinical presentation of β-thalassaemia varies widely from a mild asymptomatic form in thalassaemia minor, to a severe disease in thalassaemia major where individuals are dependant on life-long blood transfusions. The hallmark of thalassaemia syndromes is the production of defective red blood cells that are removed by the spleen resulting in an enlarged hyperfunctioning spleen (splenomegaly). Removal of the spleen may thus prolong red blood cell survival by reducing the amount of red blood cells removed from circulation and may ultimately result in the reduced need for blood transfusions.

OBJECTIVES

To assess the efficacy and safety of splenectomy in people with β-thalassaemia major or intermedia.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Review Group's Haemoglobinopathies Trials Register, compiled from searches of electronic databases and the handsearching of journals and conference abstract books. We also searched online trial registries and the reference lists of relevant articles and reviews (27 July 2018).Date of the most recent search of the Group's trials register: 02 August 2019.

SELECTION CRITERIA

We included randomised controlled and quasi-randomised controlled studies of people of any age with thalassaemia major or intermedia, evaluating splenectomy in comparison to conservative treatment (transfusion therapy and iron chelation) or other forms of splenectomy compared to each other (laparoscopic, open, radio-frequency).

DATA COLLECTION AND ANALYSIS

Two authors independently selected and extracted data from the single included study using a customised data extraction form and assessed the risk of bias. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

One study, including 28 participants was included in the review; the results were described, primarily, in a narrative manner. This study assessed the feasibility of splenectomy using a laparoscopic approach versus open surgery. Given the lack of detail regarding the study methods beyond randomisation, the overall risk of bias for this study was unclear. The study was carried out over a period of 3.5 years, with each participant followed up only until discharge (less than one week after the intervention); it did not assess the majority of the outcomes outlined in this review (including two of the three primary outcomes, frequency of transfusion and quality of life). A total of three serious post-operative adverse events (the review's third primary outcome) were reported in the laparoscopic splenectomy group (one case of atelectasis and two cases of bleeding), compared to two events of atelectasis in the open surgery group; however, there were no significant differences between the groups for either atelectasis, risk ratio (RR) 0.50 (95% confidence interval (CI) 0.05 to 4.90) or for bleeding, RR 5.00 (95% CI 0.26 to 95.61) (very low-quality evidence). In addition, the study also reported three serious cases of intra-operative bleeding in the laparoscopic group which mandated conversion to open surgery, although the difference between groups was not statistically significant, RR 7.00 (95% CI 0.39 to 124.14) (very low-quality evidence). These effect estimates are based on very small numbers and hence are unreliable and imprecise. From this small study, there appeared to be an advantage for the laparoscopic approach, in terms of post-operative hospital stay, although the group difference was not large (median difference of 1.5 days, P = 0.03).

AUTHORS' CONCLUSIONS: The review was unable to find good quality evidence, in the form of randomised controlled studies, regarding the efficacy of splenectomy for treating thalassaemia major or intermedia. The single included study provided little information about the efficacy of splenectomy, and compared open surgery and laparoscopic methods. Further studies need to evaluate the long-term effectiveness of splenectomy and the comparative advantages of surgical methods. Due to a lack of high quality evidence from randomised controlled studies, well-conducted observational studies may be used to answer this question.