Cell salvage for minimising perioperative allogeneic blood transfusion in adults undergoing elective surgery.

BACKGROUND: Concerns regarding the safety and availability of transfused donor blood have prompted research into a range of techniques to minimise allogeneic transfusion requirements. Cell salvage (CS) describes the recovery of blood from the surgical field, either during or after surgery, for reinfusion back to the patient. OBJECTIVES: To examine the effectiveness of CS in minimising perioperative allogeneic red blood cell transfusion and on other clinical outcomes in adults undergoing elective or non-urgent surgery. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, three other databases and two clinical trials registers for randomised controlled trials (RCTs) and systematic reviews from 2009 (date of previous search) to 19 January 2023, without restrictions on language or publication status. SELECTION CRITERIA: We included RCTs assessing the use of CS compared to no CS in adults (participants aged 18 or over, or using the study's definition of adult) undergoing elective (non-urgent) surgery only. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included 106 RCTs, incorporating data from 14,528 participants, reported in studies conducted in 24 countries. Results were published between 1978 and 2021. We analysed all data according to a single comparison: CS versus no CS. We separated analyses by type of surgery. The certainty of the evidence varied from very low certainty to high certainty. Reasons for downgrading the certainty included imprecision (small sample sizes below the optimal information size required to detect a difference, and wide confidence intervals), inconsistency (high statistical heterogeneity), and risk of bias (high risk from domains including sequence generation, blinding, and baseline imbalances). Aggregate analysis (all surgeries combined: primary outcome only) Very low-certainty evidence means we are uncertain if there is a reduction in the risk of allogeneic transfusion with CS (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.59 to 0.72; 82 RCTs, 12,520 participants). Cancer: 2 RCTs (79 participants) Very low-certainty evidence means we are uncertain whether there is a difference for mortality, blood loss, infection, or deep vein thrombosis (DVT). There were no analysable data reported for the remaining outcomes. Cardiovascular (vascular): 6 RCTs (384 participants) Very low- to low-certainty evidence means we are uncertain whether there is a difference for most outcomes. No data were reported for major adverse cardiovascular events (MACE). Cardiovascular (no bypass): 6 RCTs (372 participants) Moderate-certainty evidence suggests there is probably a reduction in risk of allogeneic transfusion with CS (RR 0.82, 95% CI 0.69 to 0.97; 3 RCTs, 169 participants). Very low- to low-certainty evidence means we are uncertain whether there is a difference for volume transfused, blood loss, mortality, re-operation for bleeding, infection, wound complication, myocardial infarction (MI), stroke, and hospital length of stay (LOS). There were no analysable data reported for thrombosis, DVT, pulmonary embolism (PE), and MACE. Cardiovascular (with bypass): 29 RCTs (2936 participants) Low-certainty evidence suggests there may be a reduction in the risk of allogeneic transfusion with CS, and suggests there may be no difference in risk of infection and hospital LOS. Very low- to moderate-certainty evidence means we are uncertain whether there is a reduction in volume transfused because of CS, or if there is any difference for mortality, blood loss, re-operation for bleeding, wound complication, thrombosis, DVT, PE, MACE, and MI, and probably no difference in risk of stroke. Obstetrics: 1 RCT (1356 participants) High-certainty evidence shows there is no difference between groups for mean volume of allogeneic blood transfused (mean difference (MD) -0.02 units, 95% CI -0.08 to 0.04; 1 RCT, 1349 participants). Low-certainty evidence suggests there may be no difference for risk of allogeneic transfusion. There were no analysable data reported for the remaining outcomes. Orthopaedic (hip only): 17 RCTs (2055 participants) Very low-certainty evidence means we are uncertain if CS reduces the risk of allogeneic transfusion, and the volume transfused, or if there is any difference between groups for mortality, blood loss, re-operation for bleeding, infection, wound complication, prosthetic joint infection (PJI), thrombosis, DVT, PE, stroke, and hospital LOS. There were no analysable data reported for MACE and MI. Orthopaedic (knee only): 26 RCTs (2568 participants) Very low- to low-certainty evidence means we are uncertain if CS reduces the risk of allogeneic transfusion, and the volume transfused, and whether there is a difference for blood loss, re-operation for bleeding, infection, wound complication, PJI, DVT, PE, MI, MACE, stroke, and hospital LOS. There were no analysable data reported for mortality and thrombosis. Orthopaedic (spine only): 6 RCTs (404 participants) Moderate-certainty evidence suggests there is probably a reduction in the need for allogeneic transfusion with CS (RR 0.44, 95% CI 0.31 to 0.63; 3 RCTs, 194 participants). Very low- to moderate-certainty evidence suggests there may be no difference for volume transfused, blood loss, infection, wound complication, and PE. There were no analysable data reported for mortality, re-operation for bleeding, PJI, thrombosis, DVT, MACE, MI, stroke, and hospital LOS. Orthopaedic (mixed): 14 RCTs (4374 participants) Very low- to low-certainty evidence means we are uncertain if there is a reduction in the need for allogeneic transfusion with CS, or if there is any difference between groups for volume transfused, mortality, blood loss, infection, wound complication, PJI, thrombosis, DVT, MI, and hospital LOS. There were no analysable data reported for re-operation for bleeding, MACE, and stroke. AUTHORS' CONCLUSIONS: In some types of elective surgery, cell salvage may reduce the need for and volume of allogeneic transfusion, alongside evidence of no difference in adverse events, when compared to no cell salvage. Further research is required to establish why other surgeries show no benefit from CS, through further analysis of the current evidence. More large RCTs in under-reported specialities are needed to expand the evidence base for exploring the impact of CS.

Multiple iliopsoas tendons: a cadaveric study and treatment implications for internal snapping hip syndrome.

PURPOSE: This cadaveric study aimed at describing the anatomical variations of the iliopsoas complex. METHODS: The iliopsoas complex was dissected unilaterally in 28 formalin-embalmed cadavers-13 males and 15 females with a mean age of 85.6 years. The number, courses and widths of the iliacus and psoas major tendons were determined. Patients with previous hip surgery were excluded. The following measurements were taken from the mid-inguinal point: the distance to the point of union of the psoas major and iliacus tendon; and the distance to the most distal insertion of iliopsoas. RESULTS: The presence of single, double and triple tendon insertions of iliopsoas were found in 12, 12 and 4 of the 28 specimens, respectively. When present, double and triple tendons inserted separately onto the lesser trochanter. The average length of the iliopsoas tendon from the mid-inguinal point to the most distal attachment at the lesser trochanter was 122.3 ± 13.0 mm. The iliacus muscle bulk merged with psoas major at an average distance of 24.9 ± 17.9 mm proximal to the mid-inguinal point. In all cases, the lateral-most fibres of iliacus yielded a non-tendinous, muscular insertion on to the anterior surface of the lesser trochanter and the femoral shaft, rather than joining onto the main iliopsoas tendon(s). The average total width of the psoas major tendon decreased with an increasing number of tendons: 14.6 ± 2.2 mm (single tendon), 8.2 ± 3.0 mm (2 tendons present) and 5.9 ± 1.1 mm (3 tendons present) (P < 0.001). CONCLUSIONS: The results of this study suggest that multiple tendinous insertions of iliopsoas are present as an anatomical variant in more than 50% of the population. The non-tendinous muscular insertion of the iliopsoas on to the anterior surface of the lesser trochanter and femoral shaft found represents a novel anatomical variant not previously described. LEVEL OF EVIDENCE: Level V.