Removal of the spleen in people with thalassaemia major and intermedia

Review question

We reviewed the evidence comparing the removal of the spleen (splenectomy) to other treatments (such as blood transfusion and chelation (removal of excess iron) in people with thalassaemia major and intermedia.

Background

Thalassemia is a genetic disease, causing a defect in haemoglobin, which carries oxygen in red blood cells. The disease is grouped into thalassaemia minor, intermedia and major, depending on the severity and the genetic defect. People with thalassaemia major, and often people with thalassaemia intermedia, require frequent blood transfusions to compensate for the poor quality red blood cells.

The defect results in mis-shapen red blood cells, which are removed by the spleen. The spleen in turn becomes overloaded and enlarged. Removing the spleen can lengthen red blood cell survival and reduce the need for transfusion.

We wanted to see whether current evidence showed that removing the spleen was safe and effective in the long term; and compare the advantages and disadvantages of different types of surgical techniques for splenectomy.

Search date

The evidence is current to: 25 April 2016.

Study characteristics

One study with a total of 28 participant was included in the review. The study compared two methods of splenectomy - laparoscopic (keyhole) versus an open surgical approach. Study participants were recruited over a period of 3.5 years, but participants were only followed up to the end of their hospital stay (usually less than one week).

Key results

The study evaluated the two types of surgery and was not intended to assess the effectiveness of operation itself. Only one of our three primary outcomes were reported, the number of people experiencing major adverse events (bleeding during and after the operation and complete or partial collapse of a lung). However, the amount of information available is not sufficient enough to draw any reliable conclusions. Hence, we were unable to provide recommendations regarding the use of splenectomy in people with thalassaemia. Appropriate clinical judgement, in view of the various risks and benefits described by other lower quality sources of evidence (e.g. observational studies), may be necessary when considering splenectomy in people with thalassaemia.

Quality of the evidence

While we are satisfied that the participants had equal chances of undergoing either type of surgery, there is not enough information on other aspects of the study to make any overall judgement on its quality.

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.

Read the full abstract...
Background: 

Thalassaemia is a genetic disease of the haemoglobin protein in red blood cells. It is classified into thalassaemia minor, intermedia and major, depending on the severity of the disease and the genetic defect. Thalassaemia major and intermedia require frequent blood transfusions to compensate for the lack of well-functioning red blood cells, although this need is significantly less in thalassaemia intermedia.

Damaged or defective red blood cells are normally eliminated in the spleen. In people with thalassaemia there is a large quantity of defective red blood cells which results 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 beta-thalassaemia major or intermedia.

Search strategy: 

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 the reference lists of relevant articles and reviews.

Date of the most recent search: 25 April 2016.

Selection criteria: 

We included randomised controlled studies 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.

Main results: 

One study, including 28 participants was included in the review; the results were described, primarily, in a narrative manner. The study assessed the feasibility of splenectomy using laparoscopy in comparison to 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 0.50 (95% confidence interval 0.05 to 4.90) or for bleeding, risk ratio 5.00 (95% confidence interval 0.26 to 95.61). 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, risk ratio 7.00 (95% confidence interval 0.39 to 124.14). 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).

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