Red-cell salvage in urological surgery

Authors


Rebecca S. Hamm, Department of Urology, Royal Devon and Exeter NHS Trust, Exeter, Devon, UK.
e-mail: rebecca.hamm@virgin.net

Significant blood loss during major urological surgery is common and in the UK is usually replaced by transfusion of donated homologous blood. This is not always entirely satisfactory because of the increasingly limited availability and the well-documented risks associated with homologous blood transfusion. Most recently concerns have been raised about possible contamination of donated blood with variant Creuzfeldt-Jakob disease [1] which has caused the Blood Transfusion Service to discontinue donations from those who have received a blood transfusion since 1 January 1980. This is likely to have a significant affect on the stocks of donated blood and means that alternatives to homologous blood transfusion should be actively pursued.

Autologous blood transfusion is the collection of blood from an individual for the purpose of re-infusion into the same individual at a later time. Autologous blood transfusion can be in the form of preoperative autologous blood donation (PABD), intraoperative cell salvage (IOCS) or postoperative cell salvage and acute normovolaemic haemodilution (ANH).

The first PABD was described in 1921 by F.C. Grant in a patient undergoing surgery for a cerebellar tumour. PABD became standard medical practice in the 1920s and 30s and was frequently used by Cushing during cranial surgery. It was not until World War II that transfusion practice changed and homologous products became readily available.

Cell salvage with direct reinfusion was described in haemothorax cases in 1931 by Brown and Debenheim. In 1943 Arnold Griswold developed the first cell salvage auto-transfusion device, collecting blood in a bottle by suction, straining it through a cheese cloth and then re-infusing it. Modern cell salvage techniques still use this basic principle.

In ANH, 1–3 units of whole blood are drawn from the patient after the onset of anaesthesia and the volume is replaced with colloid or crystalloid volume expanders. Any blood lost during surgery is therefore more dilute and the withdrawn blood can be re-infused at the end of the procedure.

In modern cell salvage techniques (IOCS) salvaged blood is aspirated from the surgical field, anticoagulated in the suction device and then collected in a sterile collection container. When an adequate amount of blood has been collected it is pumped into a spinning centrifuge bowl. Red cells, being the heaviest components of blood, collect at the lowest point in the bowl and supernatant containing the other components of blood spill over into a waste bag. Sterile saline solution is pumped through the spinning centrifuge bowl and displaces the lighter remaining contaminants. Once this process is complete the red blood cells are re-suspended and can be transfused, usually immediately, or can be stored under specific conditions for up to 6 h.

IOCS has become the mainstay of many general surgical operations where there is a large volume blood loss, e.g. ruptured aortic aneurysm repair, greatly reducing the need for homologous blood transfusion. However, there has been concern that IOCS is not safe in the presence of malignant disease, because malignant cells may spill into the operative field, be taken into the cell salvage machine, and because they are heavy like red cells, returned to the patient. The use of leukocyte depletion filters can reduce the risk of such occurrence but concerns remain as to whether use of IOCS may compromise surgical cure. Malignant cells have been found in the circulation during surgery even when IOCS is not used [2], but the significance of these circulating cells is not clear. If re-infused cells were clinically significant it would be expected that patients having had IOCS might present with early widespread metastases, or at least unexpected lung metastases. This has not proven to be the case in bladder, renal or prostate cancer. The four reports in Table 1[3–6] illustrate experience of nearly 250 cases of IOCS, with no cases of early unexpected metastasis.

Table 1.  Reports of IOCS in urology
RefDateN patientsOperationOutcomeComment
  1. RC, RP, RN, radical cystectomy, prostatectomy, nephrectomy.

[3]198624RCTwo died from local recurrence, LN metIOCS is safe
10RPOne pelvic recurrence 
13RNTwo lung metastases 
[4]198949RCSix patients died by follow-up mean 23.8 monthsOverlap of patients with above series
[5]200387RPNo difference in outcome for IOCS over pre-donation or no transfusionIOCS is safe
[6]200162RPNo difference in progression-free survival with 101 patients who pre-donated bloodNo increased risk of early biochemical progression

Since 1996 it has been the policy in our unit to have IOCS available at all major open urological surgery. We have experience of >150 cases, including 74 cystectomies, 30 radical nephrectomies and 37 radical prostatectomies, and have transfused over 600 units of salvaged blood. There have been no cases of early lung or diffuse metastases suggestive of spread of malignant disease by IOCS.

The theoretical risk of metastatic spread secondary to IOCS has not become apparent, although the very real risk of spread of viral infection and other complications of homologous transfusion remain.

Ancillary