Intra-operative cell salvage in urological surgery: a systematic review and meta-analysis of comparative studies

OBJECTIVE

To evaluate systematically the safety and efficacy of intra-operative cell salvage (ICS) in urology.

METHODS

A search of Medline, Embase and Cochrane Library to August 2017 was performed using methods pre-published on PROSPERO. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. Eligible titles were comparative studies published in English that used ICS in urology. Primary outcomes were allogeneic transfusion rates (ATRs) and tumour recurrence. Secondary outcomes were complications and cost.

RESULTS

Fourteen observational studies were identified, with a total of 4 536 patients. ICS was compared with no the blood conservation technique (seven studies), preoperative autologous donation (PAD; five studies) or both (two studies). Cohorts underwent open prostatectomy (11 studies), open cystectomy (two studies) or open partial nephrectomy (one study). Meta-analysis was possible only for ATRs within prostatectomy studies. In this setting, ICS reduced ATR compared with no the blood conservation technique (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.15-0.76) but not PAD (OR 0.76, 95% CI 0.39-1.31). In the non-prostatectomy setting, ATRs amongst patients who underwent ICS were significantly higher or similar in one and two studies, respectively. Tumour recurrence was found to be significantly less common (two studies), similar (eight studies) or not measured (four studies). All six studies reporting complications found no difference in their ICS cohorts. Regarding cost, one study from 1995 found ICS more expensive than PAD, while two more recent studies found ICS to be cheaper than no blood conservation technique. As a result of inter-study heterogeneity, meta-analyses were not possible for recurrence, complications or cost.

CONCLUSION

Low-level evidence exists that, compared with other blood conservation techniques, ICS reduces ATR and cost while not affecting complications. It does not appear to increase tumour recurrence post-prostatectomy, although follow-up durations were short. Small study sizes and short follow-ups mean conclusions cannot be drawn with regard to recurrence after nephrectomy or cystectomy. Randomized trials with long-term follow-up evaluating ICS in urology are required.

Lactate dehydrogenase and Haemolysis Index as quality control markers of haemolysis in intra-operative cell salvage

OBJECTIVES

The aim of this investigation was to explore the potential use of the tests lactate dehydrogenase (LDH) and Haemolysis Index as haemolysis markers in intra-operative cell salvage (ICS) blood in comparison to plasma free haemoglobin levels.

BACKGROUND

Quality control (QC) should be seen as a fundamental part of any ICS blood conservation programme, however, due to lack of available knowledge, familiarity and experience, QC is still a comparatively new subject. A QC pilot scheme is currently being undertaken by the Royal Cornwall Hospital in association with the UK Cell Salvage Action Group to explore potential markers that can be used to assess the quality of blood obtained from ICS. This test list should be available to all ICS users and achievable within financial budgets. Currently this proposed test list includes a full blood count, a protein marker such as urine albumin/microalbumin and heparin monitoring. Haemolysis testing is another key marker.

METHODS/MATERIALS

Samples were collected from ICS processed blood and allogeneic SAGM leucodepleted red cell units and processed for plasma free haemoglobin, LDH and Haemolysis Index.

RESULTS

There was a very strong correlation between plasma free haemoglobin and LDH (0.960), and plasma free haemoglobin and the Haemolysis Index (0.944).

CONCLUSION

We have shown that the LDH and Haemolysis Index tests are suitable and reliable alternatives for measuring haemolysis from samples obtained from ICS or allogeneic blood. We have incorporated the LDH test into our Hospital's ICS QC package and recommend that this test is considered for all ICS QC samples.