Reduction of Blood Loss and Transfusion Requirement by Aprotinin in Posterior Lumbar Spine Fusion

Comparative efficacy and safety of different hemostatic medications during spinal surgery: A network meta-analysis

BACKGROUND

Significant blood loss is still one of the most frequent issues in spinal surgery. There were different hemostatic methods to prevent blood loss during spinal surgery. However, the optimal hemostatic therapy for spinal surgery is controversial. The purpose of this study was to assess the efficacy and safety of different hemostatic therapies in spinal surgery.

METHODS

Two independent reviewers conducted electronic literature searches in 3 electronic databases (PubMed, Embase, and Cochrane library database) as well as a manual search to identify eligible clinical studies from inception to Nov 2022. Studies that including different hemostatic therapy (tranexamic acid [TXA], epsilon-acetyl aminocaproic acid [EACA], and aprotinin [AP]) for spinal surgery were included. The Bayesian network meta-analysis was performed with a random effects model. The surface under the cumulative ranking curve (SUCRA) analysis was performed to determine the ranking order. All analyses were performed by R software and Stata software. P value less than .05 was identified as statistically significant.

RESULTS

Finally, a total of 34 randomized controlled trials met the inclusion criteria and finally included in this network meta-analysis. The SUCRA shows that TXA ranked first (SUCRA, 88.4%), AP ranked second (SUCRA, 71.6%), EACA ranked third (SUCRA, 39.9%), and placebo ranked the last (SUCRA, 0.3%) as for total blood loss. The SUCRA shows that TXA ranked first (SUCRA, 97.7%), AP ranked second (SUCRA, 55.8%), EACA ranked third (SUCRA, 46.2%), and placebo ranked the last (SUCRA, 0.2%) for need for transfusion.

CONCLUSIONS

TXA appears optimal in the reduction of perioperative bleeding and blood transfusion during spinal surgery. However, considering the limitations in this study, more large-scale, well-designed randomized controlled trials are needed to confirm these findings.

Multilevel Arthrodesis for Adult Spinal Deformity: When Should We Anticipate Major Blood Loss?

STUDY DESIGN

Retrospective study.

OBJECTIVES

To analyze predictors of major blood loss (MBL) during multilevel arthrodesis for adult spinal deformity (ASD).

SUMMARY OF BACKGROUND DATA

ASD surgery is associated with substantial blood loss.

METHODS

We identified 237 patients with ASD who underwent spinal arthrodesis of five or more levels by one surgeon and who had complete data on blood loss. MBL was defined as normalized blood loss above the 75th percentile (ie, >49%). Patients with MBL were compared with those without MBL with respect to baseline characteristics, preoperative laboratory values, and surgical factors. Alpha level = 0.05.

RESULTS

A total of 176 patients (74%) had MBL. On univariate analysis, the MBL and non-MBL groups differed with respect to diagnosis of osteoporosis (p = .002), curve type (p = .012), number of levels fused (p < .001), and presence/type of osteotomy (p < .001). The groups were similar in age (p = .605) and proportion of patients undergoing revision surgery (p = .410). Multivariate analysis identified the following predictors of MBL: three-column osteotomy (odds ratio [OR] = 4.1, 95% confidence interval [CI] = 1.7, 9.7), arthrodesis of 11 or more levels (OR = 3.2, 95% CI = 1.4, 7.6), malalignment in both coronal and sagittal planes (OR = 3.2, 95% CI = 1.4, 7.3), and osteoporosis (OR = 2.4, 95% CI = 1.1, 5.4).

CONCLUSION

Patients with ASD undergoing spinal arthrodesis of five or more levels are at risk for MBL. Three-column osteotomy, arthrodesis of ≥11 levels, malalignment in both coronal and sagittal planes, and osteoporosis appear to be risk factors for MBL.

LEVEL OF EVIDENCE

Level III.

Efficacy and Safety of Topical Use of Tranexamic Acid in Reducing Blood Loss During Primary Lumbar Spinal Surgery: A Retrospective Case Control Study

STUDY DESIGN

A retrospective case-control study.

OBJECTIVE

To compare postoperative blood loss, amount of allogeneic blood transfusion, removal time of drainage tube, length of hospital stay, and complications associated with tranexamic acid (TXA).

SUMMARY OF BACKGROUND DATA

Spinal fusion surgery can be associated with significant blood loss. To the best of our knowledge, very few published studies exist reporting the effect of topical use of tranexamic acid (tTXA) on decreasing the blood loss in patients undergoing posterior lumbar spinal fusions.

METHODS

We conducted a retrospective nonrandomized case-control study of 100 adults undergoing posterior lumbar spinal fusion surgery. In the tTXA group (n = 50), wound surface was soaked with TXA (1 g in 100 mL saline solution) for 5 minutes before wound closure. In the control group (n = 50), wound surface was soaked with the same volume of normal saline. The postoperative blood loss, removal time of drainage tube, amount of allogeneic blood transfusion, and length of hospital stay were compared between the two groups. And the complications of TXA were also collected.

RESULTS

In the tTXA group, the postoperative blood loss, removal time of drainage tube, postoperative length of hospital stay were significantly lower than those in the control group (155.2 ± 104.3 mL vs. 278.6 ± 124.1 mL, 2.0 ± 0.6 d vs. 2.4 ± 0.5 d, 4.7 ± 1.4 d vs. 5.6 ± 2.3 d, P < 0.05, respectively). There was no significant difference in blood transfusion between two groups. No significant changes were noticed in terms of coagulation function, and no complications associated with TXA were observed.

CONCLUSION

tTXA can significantly reduce postoperative blood loss, accelerate removal of drainage tube, shorten the duration of hospital stay, while not increasing the complication incidence in patients undergoing posterior lumbar spinal fusion surgery.

LEVEL OF EVIDENCE

3.

Comparison of harmonic blade versus traditional approach in canine patients undergoing spinal decompressive surgery for naturally occurring thoracolumbar disk extrusion

Objectives

To assess feasibility of the harmonic Osteovue blade (HOB) for use in the soft tissue approach for dogs undergoing hemilaminectomy and to compare outcomes between dogs undergoing HOB or traditional approach (TRAD).

Methods

A prospective randomized clinical trial was performed using 20 client-owned dogs with thoracolumbar intervertebral disk extrusion requiring hemilaminectomy. Dogs were randomly assigned to HOB or TRAD. Neurologic function and pain scores were assessed pre-operatively. Intraoperative blood loss and surgical approach time as well as postoperative pain and wound healing scores were recorded. Additionally, neurologic recovery and owner perceived quality of life were recorded at day 10 and 30 postoperative.

Results

There was no significant difference in sex distribution, weight, age, preoperative neurological grade and pain score, and perioperative outcome measures between groups. Intraoperative total blood loss was minimal for HOB and TRAD (median: 0 ml (range 0–9) and 2.2 ml (range 0–6.8), respectively; p = 0.165) and approach times were similar (median: 7 min (range 5–12) and 8 min (range 5–13), respectively; p = 0.315). While changes in wound healing scores were similar, changes in postoperative pain scores and neurological function were significantly improved in the HOB compared to the TRAD group. Postoperative complications in the HOB group consisted of automutilation of part of the incision and development of a small soft, non-painful subcutaneous swelling in 1 dog each.

Conclusions

The HOB is a safe and effective tool for the soft tissue approach for routine spinal surgery in dogs and is associated with decreased pain and increased neurological function post-surgery.

Effectiveness and Safety of Tranexamic Acid in Spinal Deformity Surgery

Objective

Spinal deformity surgery has the potential risk of massive blood loss. To reduce surgical bleeding, the use of tranexamic acid (TXA) became popular in spinal surgery, recently. The purpose of this study was to determine the effectiveness of intra-operative TXA use to reduce surgical bleeding and transfusion requirements in spinal deformity surgery.

Methods

A total of 132 consecutive patients undergoing multi-level posterior spinal segmental instrumented fusion (≥5 levels) were analyzed retrospectively. Primary outcome measures included intraoperative estimated blood loss (EBL), transfusion amount and rate of transfusion. Secondary outcome measures included postoperative transfusion amount, rate of transfusion, and complications associated with TXA or allogeneic blood transfusions.

Results

The number of patients was 89 in TXA group and 43 in non-TXA group. There were no significant differences in demographic or surgical traits between the groups except hypertension. The EBL was significantly lower in TXA group than non-TXA group (841 vs. 1336 mL, p=0.002). TXA group also showed less intra-operative and postoperative transfusion requirements (544 vs. 812 mL, p=0.012; 193 vs. 359 mL, p=0.034). Based on multiple regression analysis, TXA use could reduce surgical bleeding by 371 mL (37 % of mean EBL). Complication rate was not different between the groups.

Conclusion

TXA use can effectively reduce the amount of intra-operative bleeding and transfusion requirements in spinal deformity surgery. Future randomized controlled study could confirm the routine use of TXA in major spinal surgery.

Antifibrinolytic agents for reducing blood loss in scoliosis surgery in children

BACKGROUND

This is an updated version of the original Cochrane review first published in 2008. Scoliosis surgery is often associated with substantial blood loss and potentially detrimental effects in children. Antifibrinolytic agents are often used to reduce perioperative blood loss. Clinical trials have evaluated their efficacy in children undergoing surgical correction of scoliosis, but no systematic review has been published. This review was first published in 2008 and was updated in 2016.

OBJECTIVES

To assess the efficacy and safety of aprotinin, tranexamic acid and aminocaproic acid in reducing blood loss and transfusion requirements in children undergoing surgery for correction of idiopathic or secondary scoliosis.

SEARCH METHODS

We ran the search for the previous review in June 2007. For this updated version, we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 7), MEDLINE (1946 to August week 1 2015), Embase (1947 to 2015 week 38), Latin American Caribbean Health Sciences Literature (LILACS) (1982 to 14 August 2015), Database of Abstracts of Reviews of Effects (DARE; 2015, Issue 2) and reference lists of reviews and retrieved articles for randomized controlled trials in any language. We also checked the clinical trial registry at http://www.clinicaltrials.gov on 8 October 2015.

SELECTION CRITERIA

We included blinded and unblinded randomized controlled trials (RCTs) that evaluated the effects of antifibrinolytics on perioperative blood loss in children 18 years of age or younger and undergoing scoliosis surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. The primary outcome was total blood loss (intraoperative and postoperative combined). Secondary efficacy outcomes were the number of participants receiving blood transfusion (both autologous and allogeneic) or receiving allogeneic blood transfusion alone, and the total amount of blood transfused. Safety outcomes included the number of deaths, the number of participants reporting any adverse event or a serious adverse event, withdrawals due to adverse events and the number of participants experiencing a specific adverse event (i.e. renal insufficiency, hypersensitivity or thrombosis). We assessed methodological risk of bias for each included study and employed the GRADE approach to assess the overall quality of the evidence.

MAIN RESULTS

We included three new studies (201 participants) in this updated review, for a total of nine studies (455 participants). All but one study employed placebo as the control group intervention. For the primary outcome, antifibrinolytic drugs decreased the amount of perioperative blood loss by 427 mL (95% confidence interval (CI) 251 to 603 mL), for a reduction of over 20% versus placebo. We rated the quality of evidence for our primary outcome as low on the basis of unclear risk of bias for several domains in most studies and the small total number of participants.For secondary outcomes, fewer participants receiving antifibrinolytic drugs received transfusion (allogeneic or autologous) versus those receiving placebo (risk ratio (RR) 0.65, 95% CI 0.50 to 0.85, number needed to treat to prevent one additional harmful outcome (NNTp) 5; very low-quality evidence). Only two studies specifically evaluated the number of participants transfused with only allogeneic blood (risk difference (RD) -0.15, 95% CI -0.26 to -0.03, NNTp 7; very low-quality evidence). Antifibrinolytic drugs decreased the volume of blood transfused by 327 mL (95% CI -186 to -469 mL; low-quality evidence).No study reported deaths in active or control groups. Data were insufficient to allow performance of meta-analysis for any safety outcome. No studies adequately described their methods in assessing safety. The only adverse event of note occurred in one study, when three participants in the placebo group developed postoperative deep vein thrombosis.

AUTHORS' CONCLUSIONS

Since the last published version of this review (2008), we have found three new studies. Additional evidence shows that antifibrinolytics reduce the requirement for both autologous and allogeneic blood transfusion. Limited evidence of low to very low quality supports the use of antifibrinolytic drugs for reducing blood loss and decreasing the risk, and volume, of transfusion in children undergoing scoliosis surgery. Evidence is insufficient to support the use of a particular agent, although tranexamic acid may be preferred, given its widespread availability. The optimal dose regimen for any of these three agents has not been established. Although adverse events appear to occur infrequently, evidence is insufficient to confirm the safety of these agents, particularly for rare but potentially catastrophic events. No long-term safety data are available.

Efficacy and Safety of Antifibrinolytic Agents in Reducing Perioperative Blood Loss and Transfusion Requirements in Scoliosis Surgery: A Systematic Review and Meta-Analysis

Background

Routine use of antifibrinolytic agents in spine surgery is still an issue of debate.

Objective

To gather scientific evidence for the efficacy and safety of antifibrinolytic agents including aprotinin, tranexamic acid (TXA) and epsilon aminocaproic acid (EACA, traditionally known as Amicar) in reducing perioperative blood loss and transfusion requirements in scoliosis surgery.

Methods

We conducted a systematic review and meta-analysis for randomized controlled trials (RCTs), retrospective case-control studies, and retrospective cohort studies on the use of antifibrinolytic agents in scoliosis surgery by searching in the MEDLINE and EMBASE databases and the Cochrane Database of Systematic Reviews and Controlled Trials of papers published from January 1980 through July 2014. Safety of the antifibrinolytic agents was evaluated in all included studies, while efficacy was evaluated in RCTs.

Results

Eighteen papers with a total of 1,158 patients were eligible for inclusion in this study. Among them, 8 RCTs with 450 patients were included for evaluation of pharmacologic efficacy (1 RCT was excluded because of a lack of standard deviation data). Mean blood loss was reduced in patients with perioperative use of antifibrinolytic agents by 409.25 ml intraoperatively (95% confidence interval [CI], 196.57–621.94 ml), 250.30 ml postoperatively (95% CI, 35.31–465.30), and 601.40 ml overall (95% CI, 306.64–896.16 ml). The mean volume of blood transfusion was reduced by 474.98 ml (95% CI, 195.30–754.67 ml). The transfusion rate was 44.6% (108/242) in the patients with antifibrinolytic agents and 68.3% (142/208) in the patients with placebo. (OR 0.38; 95% CI; 0.25–0.58; P<0.00001, I² = 9%). All studies were included for evaluation of safety, with a total of 8 adverse events reported overall (4 in the experimental group and 4 in the control group).

Conclusion

The systematic review and meta-analysis indicated that aprotinin, TXA, and EACA all significantly reduced perioperative blood loss and transfusion requirements in scoliosis surgery. There was no evidence that the use of antifibrinolytic agents was a risk factor for adverse events, especially thromboembolism, in scoliosis surgery.

Use of aprotinin to reduce blood loss and transfusion in major orthopedic surgery: a meta-analysis

BACKGROUD

Conflicting reports have been published regarding the effectiveness and safety of aprotinin in reducing blood loss and transfusion in patients undergoing orthopedic surgery. We performed a meta-analysis to evaluate the effectiveness and safety of aprotinin in reducing blood loss and transfusion in major orthopedic surgery.

MATERIALS AND METHODS

MEDLINE, PubMed, EMBASE and Cochrane databases were searched for relevant studies. Only randomized controlled trials were eligible for this study. The weighted mean difference in blood loss, and number of transfusions per patient and the summary risk ratio of transfusion requirements, and deep-vein thrombosis (DVT) were calculated in the aprotinin-treated group and the control group.

RESULTS

Eighteen randomized controlled trials involving 1276 patients were included. The use of aprotinin reduced total blood loss by a mean of 498.88 ml (95% confidence interval [CI]; -735.03 to -262.72), intra-operative blood loss by a mean of 246.11 ml (95% CI; -352.11 to -140.11), post-operative blood loss by a mean of 169.11 ml (95% CI; -234.06 to -105.55), the number of blood transfusions per patient by 0.93 units (95% CI; -1.36 to -0.51). Aprotinin led to a signficant reduction in transfusion requirements (RR 0.59; 95% CI; 0.51 to 0.69) and no increase in the risk of DVT (RR 0.58; 95% CI; 0.38 to 1.08).

CONCLUSION

The meta-analysis shows that aprotinin could significantly reduce blood loss and blood transfusion requirements in patients undergoing orthopedic surgery, and it did not appear to increase the risk of DVT.

Volume replacement therapy during hip arthroplasty using hydroxyethyl starch (130/0.4) compared to lactated Ringer decreases allogeneic blood transfusion and postoperative infection

BACKGROUND AND OBJECTIVES

Hydroxyethyl starch (HES) 130/0.4 is considered an effective plasma expander when compared to crystalloids. There is controversy around its superiority regarding hemodynamic optimization and about possible detrimental effects on coagulation. The aim of this study was to compare the effects of HES 130/0.4 to lactated Ringer solution during hip arthroplasty in adult patients under spinal anesthesia regarding intraoperative bleeding, hemodynamic parameters, coagulation profile, transfusion requirements and clinical outcomes.

METHODS

In this randomized, controlled trial, 48 patients scheduled for hip arthroplasty with spinal anesthesia were randomized into two groups: 24 patients were allocated to receive a preload of 15 mL.kg(-1) of HES 130/0.4 and 24 patients received a preload of 30 mL.kg(-1) lactated Ringer solution before surgery. Hemodynamic measurements, hemoglobin concentrations, biochemical parameters and coagulation tests were evaluated in three periods during surgical procedure. Patients received medical follow-up during their hospital stay and up to postoperative 30 days. Primary outcome was the requirement of red blood cell transfusion between groups during hospital stay. Secondary outcome were hemodynamic parameters, length of hospital stay, mortality and occurrence of clinical postoperative complications.

RESULTS

Red blood cell transfusion was required in 17% of patients in the HES group and in 46% in the Ringer group (p = .029). Postoperative infections were more frequently observed in the Ringer group (17%) compared to the HES group (0), p = .037. There were no significant differences between groups in mortality, hospital length of stay and clinical complications other than infection.

CONCLUSIONS

During hip arthroplasty, patients treated with hypervolemic hemodilution with hydroxyethyl starch 130/0.4 required less transfusion and presented lower infection rate compared to patients who received lactated Ringer.

Predictive factors for the use of autologous cell saver transfusion in lumbar spinal surgery

STUDY DESIGN

Retrospective review.

OBJECTIVE

To identify risk factors for cell saver transfusion in lumbar spinal surgery and determine if cell saver transfusions affected intraoperative or postoperative transfusion rates.

SUMMARY OF BACKGROUND DATA

Cell saver has been used to minimize allogeneic blood transfusion in lumbar spinal surgery. Conflicting reports exist, which call into question the efficacy of cell saver use.

METHODS

We reviewed medical records of randomly selected patients who underwent posterolateral fusion with or without transforaminal interbody fusion from July 2010 to June 2011. Transfusion rates and transfusion-related complications were determined. Binary logistic regression was performed to identify risk factors for use of autologous cell saver transfusion.

RESULTS

There were 178 females and 107 males, with a mean age of 57.2 years. Of the 285 cases, 39 had no cell saver available, 147 had cell saver available but no autologous blood was recovered or transfused and 99 had an autologous cell saver transfusion. Patients who had cell saver transfusion had a higher rate of intraoperative allogeneic blood transfusion (52%) compared with those who did not (22%). There was no significant difference in the rate of postoperative transfusions or transfusion-related reactions between patients who did and did not have cell saver transfusion. Patient's age, smoking status, American Society of Anesthesiologists grade, use of anticoagulants preoperatively, primary or revision surgery, iliac crest bone graft harvest, anesthesiologist, or surgeon had no significant effect on cell saver infusion. Body mass index (odds ratio [OR] = 1.06), number of posterolateral fusion levels fused (OR = 2.50), and number of transforaminal interbody fusions performed (OR = 2.41) were independent risk factors for the use of autologous cell saver transfusion.

CONCLUSION

Body mass index, multi-level fusion and transforaminal interbody fusion result in increased use of autologous cell saver transfusion in lumbar spinal surgery. Use of autologous cell saver transfusion did not reduce the requirement for intraoperative or postoperative allogeneic blood transfusion.

LEVEL OF EVIDENCE

2.

Efficacy of tranexamic acid in reducing blood loss in posterior lumbar spine surgery for degenerative spinal stenosis with instability: a retrospective case control study

BACKGROUND

Degenerative spinal stenosis and instability requiring multilevel spine surgery has been associated with large blood losses. Factors that affect perioperative blood loss include time of surgery, surgical procedure, patient height, combined anterior/posterior approaches, number of levels fused, blood salvage techniques, and the use of anti-fibrinolytic medications. This study was done to evaluate the efficacy of tranexamic acid in reducing blood loss in spine surgery.

METHODS

This retrospective case control study includes 97 patients who had to undergo surgery because of degenerative lumbar spinal stenosis and instability. All operations included spinal decompression, interbody fusion and posterior instrumentation (4-5 segments). Forty-six patients received 1 g tranexamic acid intravenous, preoperative and six hours and twelve hours postoperative; 51 patients without tranexamic acid administration were evaluated as a control group. Based on the records, the intra- and postoperative blood losses were measured by evaluating the drainage and cell saver systems 6, 12 and 24 hours post operation. Additionally, hemoglobin concentration and platelet concentration were reviewed. Furthermore, the number of red cell transfusions given and complications associated with tranexamic acid were assessed.

RESULTS

The postoperative hemoglobin concentration demonstrated a statistically significant difference with a p value of 0.0130 showing superiority for tranexamic acid use (tranexamic acid group: 11.08 g/dl, SD: 1.68; control group: 10.29 g/dl, SD: 1.39). The intraoperative cell saver volume and drainage volume after 24 h demonstrated a significant difference as well, which indicates a less blood loss in the tranexamic acid group than the control group. The postoperative drainage volume at12 hours showed no significant differences; nor did the platelet concentration Allogenic blood transfusion (two red cell units) was needed for eight patients in the tranexamic acid group and nine in the control group because of postoperative anemia. Complications associated with the administration of tranexamic acid, e.g. renal failure, deep vein thrombosis or pulmonary embolism did not occur.

CONCLUSIONS

This study suggests a less blood loss when administering tranexamic acid in posterior lumbar spine surgery as demonstrated by the higher postoperative hemoglobin concentration and the less blood loss. But given the relatively small volume of blood loss in the patients of this study it is underpowered to show a difference in transfusion rates.

Reducing perioperative blood loss and allogeneic blood transfusion in patients undergoing major spine surgery

At present, individual techniques, including intraoperative acute normovolemic hemodilution, use of tranexamic acid, use of intrathecal morphine, proper positioning, and modification of operative techniques, seem most promising for reducing perioperative blood loss and allogeneic blood transfusion in patients undergoing major spine surgery. Other techniques including preoperative autologous predonation; mandatory discontinuation of use of antiplatelet agents; intraoperative and postoperative red-blood-cell salvage; use of aprotinin, epsilon-aminocaproic acid, recombinant factor VIIa, or desmopressin; induced hypotension; avoidance of hypothermia; and minimally invasive operative techniques require additional studies to either establish their effectiveness or address safety considerations.

Anti-fibrinolytic use for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood have led to the development of a range of interventions to minimise blood loss during major surgery. Anti-fibrinolytic drugs are widely used, particularly in cardiac surgery, and previous reviews have found them to be effective in reducing blood loss, the need for transfusion, and the need for re-operation due to continued or recurrent bleeding. In the last few years questions have been raised regarding the comparative performance of the drugs. The safety of the most popular agent, aprotinin, has been challenged, and it was withdrawn from world markets in May 2008 because of concerns that it increased the risk of cardiovascular complications and death.

OBJECTIVES

To assess the comparative effects of the anti-fibrinolytic drugs aprotinin, tranexamic acid (TXA), and epsilon aminocaproic acid (EACA) on blood loss during surgery, the need for red blood cell (RBC) transfusion, and adverse events, particularly vascular occlusion, renal dysfunction, and death.

SEARCH STRATEGY

We searched: the Cochrane Injuries Group's Specialised Register (July 2010), Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 3), MEDLINE (Ovid SP) 1950 to July 2010, EMBASE (Ovid SP) 1980 to July 2010. References in identified trials and review articles were checked and trial authors were contacted to identify any additional studies. The searches were last updated in July 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of anti-fibrinolytic drugs in adults scheduled for non-urgent surgery. Eligible trials compared anti-fibrinolytic drugs with placebo (or no treatment), or with each other.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

This review summarises data from 252 RCTs that recruited over 25,000 participants. Data from the head-to-head trials suggest an advantage of aprotinin over the lysine analogues TXA and EACA in terms of reducing perioperative blood loss, but the differences were small. Compared to control, aprotinin reduced the probability of requiring RBC transfusion by a relative 34% (relative risk [RR] 0.66, 95% confidence interval [CI] 0.60 to 0.72). The RR for RBC transfusion with TXA was 0.61 (95% CI 0.53 to 0.70) and was 0.81 (95% CI 0.67 to 0.99) with EACA. When the pooled estimates from the head-to-head trials of the two lysine analogues were combined and compared to aprotinin alone, aprotinin appeared more effective in reducing the need for RBC transfusion (RR 0.90; 95% CI 0.81 to 0.99).Aprotinin reduced the need for re-operation due to bleeding by a relative 54% (RR 0.46, 95% CI 0.34 to 0.62). This translates into an absolute risk reduction of 2% and a number needed-to-treat (NNT) of 50 (95% CI 33 to 100). A similar trend was seen with EACA (RR 0.32, 95% CI 0.11 to 0.99) but not TXA (RR 0.80, 95% CI 0.55 to 1.17). The blood transfusion data were heterogeneous and funnel plots indicate that trials of aprotinin and the lysine analogues may be subject to publication bias.When compared with no treatment aprotinin did not increase the risk of myocardial infarction (RR 0.87, 95% CI 0.69 to 1.11), stroke (RR 0.82, 95% CI 0.44 to 1.52), renal dysfunction (RR 1.10, 95% CI 0.79 to 1.54) or overall mortality (RR 0.81, 95% CI 0.63 to 1.06). Similar trends were seen with the lysine analogues, but data were sparse. These data conflict with the results of recently published non-randomised studies, which found increased risk of cardiovascular complications and death with aprotinin. There are concerns about the adequacy of reporting of uncommon events in the small clinical trials included in this review.When aprotinin was compared directly with either, or both, of the two lysine analogues it resulted in a significant increase in the risk of death (RR 1.39, 95% CI 1.02, 1.89), and a non-significant increase in the risk of myocardial infarction (RR 1.11 95% CI 0.82, 1.50). Most of the data contributing to this added risk came from a single study - the BART trial (2008).

AUTHORS' CONCLUSIONS

Anti-fibrinolytic drugs provide worthwhile reductions in blood loss and the receipt of allogeneic red cell transfusion. Aprotinin appears to be slightly more effective than the lysine analogues in reducing blood loss and the receipt of blood transfusion. However, head to head comparisons show a lower risk of death with lysine analogues when compared with aprotinin. The lysine analogues are effective in reducing blood loss during and after surgery, and appear to be free of serious adverse effects.

Blood loss in major spine surgery: are there effective measures to decrease massive hemorrhage in major spine fusion surgery?

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine the definition and incidence of significant hemorrhage in adult spine fusion surgery, and to assess whether measures to decrease hemorrhage are effective.

SUMMARY OF BACKGROUND DATA

Significant hemorrhage and associated comorbidities in spine fusion surgery have not yet been clearly identified. Several preoperative and intraoperative techniques are currently available to reduce blood loss and transfusion requirements such as cell saver (CS), recombinant factor VIIa, and perioperative antifibrinolytic agents, such as aprotinin, tranexamic acid, and epsilon-aminocaproic acid. Their effectiveness and safety in spine surgery is uncertain.

METHODS

A systematic review of the English-language literature was undertaken for articles published between January 1990 and April 2009. Electronic databases and reference lists of key articles were searched to identify published studies examining blood loss in major spine surgery. Two independent reviewers assessed the quality of the literature using the Grading of Recommendations Assessment, Development, and Evaluation criteria. Disagreements were resolved by consensus.

RESULTS

A total of 90 articles were initially screened, and 17 ultimately met the predetermined inclusion criteria. No studies were found that attempted to define significant hemorrhage in adult spine surgery. We found that there is a high level of evidence that antifibrinolytic agents reduce blood loss and the need of transfusion in adult spine surgery; however, the safety profile of these agents is unclear. There is very low evidence to support the use of CS, recombinant factor VIIa, activated growth factor platelet gel, or normovolemic hemodilution as a method to prevent massive hemorrhage in spine fusion surgery.

CONCLUSION

There is no consensus definition of significant hemorrhage in adult spine fusion surgery. However, definition in the anesthesiology literature of massive blood loss is somewhat arbitrary but is commonly accepted to entail loss of 1 volume of the patient's total blood (60 mL/kg in adults) in <24 hours. On the basis of the current literature, there is little support for routine use of CS during elective spinal surgery. Concerns related to the use of aprotinin were such that our panel of experts unanimously recommended against its use in spine surgery on the basis of the reports of increased complications. With respect to the antifibrinolytics of the lysine analog class (tranexamic acid and aminocaproic acid), on the basis of the available efficacy and safety data, we recommend that they be considered as possible agents to help reduce major hemorrhage in adult spine surgery.

Can we safely reduce blood loss during lumbar pedicle subtraction osteotomy procedures using tranexamic acid or aprotinin? A comparative study with controls

STUDY DESIGN

Retrospective, observational study.

OBJECTIVE

To compare the safety and efficacy of 2 pharmaceutical antifibrinolytic agents, aprotinin and tranexamic acid, in controlling blood loss during lumbar pedicle subtraction osteotomy (PSO) in adults.

SUMMARY OF BACKGROUND DATA

Reconstructive spinal surgeries, in particular lumbar PSOs, have been associated with large blood losses despite interventions (intraoperative blood salvaging, controlled hypotensive anesthesia). Since the 1990s, intraoperative administration of antifibrinolytics (aprotinin, tranexamic acid, e-aminocaproic acid) has gained popularity. This study assesses the safety and efficacy of 2 antifibrinolytics, aprotinin and tranexamic acid, during adult lumbar PSO procedures at one institution.

METHODS

A retrospective comparative analysis of 44 consecutive adults undergoing posterior spinal fusion procedures with lumbar PSO at one institution was performed. Patients were analyzed according to treatment group: controls (10), aprotinin (14), and tranexamic acid (20). There were no significant differences in demographic (gender, age, comorbidities) or surgical traits (length of surgery, levels fused/exposed, preoperative hematocrit, bone graft source, primary/revision) between the 3 groups.

RESULTS

The aprotinin group had significantly less intraoperative blood loss (1114 +/- 992 mL; P < 0.01) than the tranexamic acid and control group (2102 +/- 1076 mL and 2260 +/- 1580 mL, respectively). The aprotinin group received significantly less blood (577 +/- 806 mL; P < 0.002) during the surgical procedure than the tranexamic acid (1838 +/- 1096 mL) and the control group (1502 +/- 1241 mL). There were no major intraoperative complications for any of the treatment groups. There were no postoperative cases of seizures, MI, CVA, DVT, or PE with any of the treatment groups. There was one acute tubular necrosis event in the aprotinin group, which resolved before discharge but did required several days of dialysis.

CONCLUSION

The aprotinin treatment group lost significantly less blood and received significantly fewer blood transfusions than both the tranexamic acid and control groups without significant differences in intra- and postoperative complications. These results may justify further study of aprotinin and other antifibrinolytics for this specific indication (3-column lumbar osteotomies in the adult spinal deformity population). A multicenter randomized comparative analysis would be ideal.

Epidural spinal cord compression with neurologic deficit associated with intrapedicular application of hemostatic gelatin matrix during pedicle screw insertion

STUDY DESIGN

Case report.

OBJECTIVE

In order to demonstrate the dangers of intrapedicular application of a hemostatic gelatin matrix to decrease blood loss during pedicle screw insertion, we present 2 patients who--as a result of inadvertent extravasation of the matrix into the spinal canal--developed epidural spinal cord compression (ESCC) requiring emergent decompression.

SUMMARY OF BACKGROUND DATA

Variety of hemostatic agents can control bleeding during pedicle screw insertion. We have often used a hemostatic gelatin matrix to decrease bleeding from cannulated pedicles by injecting the material into the pedicle after manually palpating the pedicle.

METHODS

Medical records and radiographic studies of 2 patients with AIS who underwent surgical treatment of their deformity and developed a neurologic deficit due to extravasation of FloSeal were reviewed.

RESULTS

A 15 year-old male underwent T4 to L2 posterior spinal fusion (PSF). During pedicle screw insertion, a change in NMEPs and SSEPs was noted. A wake-up test confirmed bilateral LE paraplegia. Screws were removed and no perforations were noted on manual palpation. MRI showed T7 to T10 ESCC. He underwent a T5 to T10 laminectomy and hemostatic gelatin matrix noted in the canal and was evacuated. He was ambulatory at 2 weeks and by 3 months he had complete recovery. The second patient was a 15 year-old female who underwent T4 to L1 PSF. Following screw insertion, deterioration in NMEPs and SSEPs was noted. Screws were removed and SCM data returned to baseline. Except for 3 screws that had an inferior breach (Left T7 and Bilateral T8), screws were reinserted and remainder of the surgery was uneventful. Postoperative examination was normal initially but 2 days later, she developed left LE numbness/weakness. Implants were removed and MRI showed T4 to T9 ESCC.She underwent a left (concave) T4 to T9 hemilaminectomy. Hemostatic gelatin matrix was noted and was evacuated. Six weeks following surgery, she had a complete neurologic recovery.

CONCLUSIONS

The use of a hemostatic gelatin matrix to decrease bleeding from cannulated pedicles during pedicle screw insertion can result in inadvertent extravasation into the spinal canal resulting in ESCC even in the absence of an apparent medial pedicle breach. Given the dangers associated with the technique, we recommend that gelatin matrix products be used judiciously during pedicle screw insertion.

Role of Amicar in surgery for neuromuscular scoliosis

STUDY DESIGN

A retrospective case-control study.

OBJECTIVE

Evaluate the effectiveness of Amicar in decreasing perioperative blood loss in patients with neuromuscular scoliosis undergoing posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI).

SUMMARY OF BACKGROUND DATA

Previously, a preliminary prospective; prospective randomized double-blind; same-day anterior and posterior spinal fusion; and fibrinogen studies have demonstrated Amicar to be effective in decreasing total perioperative blood loss and transfusion requirements in surgery for idiopathic scoliosis. Increased fibrinogen secretion is a possible explanation. We are now analyzing its effectiveness in neuromuscular scoliosis.

METHODS

Amicar was administered at 100 mg/kg over 15 minute not to exceed 5 g after anesthesia induction. Maintenance is 10 mg/kg/h until wound closure. There were 2 study groups: group 1 (n = 34), no Amicar and group 2 (n = 62) who received Amicar. The majority of patients in both groups had cerebral palsy. Total perioperative blood loss was determined from the estimated intraoperative blood loss and measured postoperative suction drainage. Total perioperative blood loss and transfusion requirements (cell saver and allogeneic) were compared using chi or Fisher exact test.

RESULTS

There was statistically less estimated intraoperative blood loss, total perioperative blood loss, and transfusion requirements in group 2. Postoperative suction drainage was also less but did not reach statistical significance. In group 1, estimated intraoperative blood loss, measured postoperative suction drainage, and total perioperative blood loss were 2194 +/- 1626 mL, 903 +/- 547 mL, and 3055 +/- 1852 mL, whereas in group 2, it was 1125 +/- 715 mL, 695 +/- 489 mL, and 1805 +/- 940 mL. Transfusion requirements were 1548 +/- 962 mL in group 1 but only 660 +/- 589 mL in group 2 (P < 0.0001). Amicar was equally effective in all diagnoses. There were no complications related to the use of Amicar.

CONCLUSION

Amicar was highly effective in decreasing perioperative blood loss and transfusion requirements in patients with neuromuscular scoliosis undergoing PSF and SSI. It was most effective in decreasing estimated intraoperative blood loss. This results in decreased transfusion requirements, costs, and potential transfusion-related complications.

Efficacy and safety of prophylactic large dose of tranexamic acid in spine surgery: a prospective, randomized, double-blind, placebo-controlled study

STUDY DESIGN

This is a double blind randomized placebo controlled study, after obtaining approval of ethics committee in the hospital and informed written consent, 64 patients were randomized equally into 2 groups (tranexamic acid (TA) and placebo).

OBJECTIVE

To evaluate efficacy and safety of large doses of TA on blood loss during spinal operations.

SUMMARY OF BACKGROUND DATA

Blood loss associated with spinal operations is a common potential cause of morbidity and often requires blood transfusion which subject patients to the known risks of blood transfusion including transmission of diseases. TA is used routinely to reduce bleeding in cardiac, orthopaedic, and hepatic surgery, however, its use in neurosurgery is uncommon and only few studies reported the use of antifibrinolytic drugs in spine surgery.

METHODS

Sixty-four consecutive patients undergoing spinal surgery with expected significant blood loss at King Khalid University Hospital between June 2005 and December 2006 were randomly assigned to 2 groups, TA and placebo. Shortly after the induction of anesthesia, patients received either TA or placebo as a loading dose of 2 g (for adults) or 30 mg/kg (for children), followed immediately by continuous infusion of 100 mg/h (for adults) or 1 mg/kg/h (for children) during surgery and for 5 hours after the operation. Outcome measures included total (i.e., intraoperative and postoperative) blood loss, amount of blood transfusion, as well as postoperative hemoglobin, and hematocrite levels. The data were analyzed by means of Statistical Package for the Social Science Version 12.0. The results were presented as mean +/- SD. Independent Student t test was used to compare the 2 groups and differences were considered significant if the P-value was <0.05.

RESULTS

There were 39 males and 25 females, ranging in age from 4 to 86 years with a mean of 51 and median of 56 years. Eighteen patients had multilevel anterior cervical discectomies with or without internal fixation, 22 patients had decompressive surgery (12 laminectomies and 10 intersegmental decompressions) for multiseg- ment spinal stenosis, 15 patients had laminectomy with posterior spinal fixation, and remaining 9 patients had laminectomy and excision of spinal tumor. Statistical analysis showed no significant differences between the 2 study groups with regard to age, sex, weight, preoperative hemoglobin, and hematocrite levels, type of surgery, as well as operative time. In contrast, patients who received TA had 49% reduction of blood loss (P < 0.007) and required 80% less blood transfusion (P < 0.008) than patients who received placebo. The hospital stay was shorter in the TA group, but it did not achieve statistical significance. There were no complications related to the use of large doses of TA in this study.

CONCLUSIONS

Prophylactic use of large doses of TA provides an effective, safe, and cheap method for reducing blood loss during and after spinal operations. Hence, TAmay help in reducing not only transfusion related complications but also operative expenses. Considering the limited number of patients in this study, our results need, however, to be validated on a larger number of patients, probably in a multicenter study.

The use of antifibrinolytic agents in spine surgery. A meta-analysis

BACKGROUND

Antifibrinolytic agents have been shown to decrease the blood loss associated with major orthopaedic surgical procedures. Spine surgery, particularly procedures performed for deformity correction and procedures involving long arthrodesis constructs, can be associated with a large amount of blood loss requiring blood transfusions. The purpose of the present study was to determine if antifibrinolytic agents reduced blood transfusions in patients managed with spine surgery and to see if one agent had a greater effect than another.

METHODS

A systematic review and meta-analysis of the available literature were performed to investigate the efficacy of aprotinin, tranexamic acid, and epsilon-aminocaproic acid in terms of reducing blood loss and blood transfusions in patients undergoing spine surgery. This meta-analysis was focused on the role of these agents in major spine operations as reported in eighteen clinical trials that included information on the drug dosage, the age of the patient, blood loss, blood transfusions, surgery complexity, and complications.

RESULTS

Compared with control groups, the treatment groups for all three antifibrinolytic agents maintained lower levels of total blood loss and transfusions associated with spine surgery. The effect size (d) of the differences in total blood loss between the treatment and control groups ranged from -0.668 (95% confidence interval, -0.971 to -0.365) to -0.936 (95% confidence interval, -1.240 to -0.632) across all three agents. The effect size (d) of the differences in total blood transfusions between the treatment and control groups ranged from -0.466 (95% confidence interval, -0.764 to -0.167) to -0.749 (95% confidence interval, -1.046 to -0.453) across all three agents.

CONCLUSIONS

Aprotinin, tranexamic acid, and epsilon-aminocaproic acid are effective for reducing blood loss and transfusions in patients managed with spine surgery. With the exception of aprotinin, the side-effect profiles of these agents have not been shown to cause any substantial morbidity or to increase the rate of thromboembolic events. Epsilon-aminocaproic acid had a greater effect on reducing blood transfusions as the complexity of surgery increased. The surgeon and/or the anesthesiologist should consider the use of antifibrinolytic agents for patients undergoing spinal procedures in which a large amount of blood loss can be expected; however, at the present time, this is not a United States Food and Drug Administration-approved indication for these agents.

Antifibrinolytic agents for reducing blood loss in scoliosis surgery in children

BACKGROUND

Scoliosis surgery is often associated with substantial blood loss and potential detrimental effects in children. Antifibrinolytic agents are often used to reduce perioperative blood loss. Clinical trials have evaluated their effect in children undergoing surgical correction of scoliosis but no systematic review has been published. We performed a systematic review on the efficacy and safety of antifibrinolytic drugs in children undergoing scoliosis surgery.

OBJECTIVES

To assess the efficacy and safety of aprotinin, tranexamic acid and aminocaproic acid in reducing blood loss and transfusion requirements in children undergoing scoliosis surgery.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2007, Issue 3), OVID MEDLINE (1950 to September 3rd 2007), LILACS (1992 to June 20th 2007) and EMBASE (1980 to July 23rd 2007). We also searched conference proceedings from 2003 to 2007 and the clinicaltrials.gov registry. No language restriction was applied.

SELECTION CRITERIA

We included blinded or unblinded randomized controlled trials that evaluated the effect of antifibrinolytics on perioperative blood loss in children that were 18 years of age or younger and undergoing scoliosis surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently performed the data extraction. Primary outcomes were mortality and number of patients transfused. Secondary outcomes were number of patients transfused with allogeneic blood, amount of total blood transfused, total blood loss and adverse events. To assess heterogeneity we used the I(2) test and for the quantitative analysis we used a fixed-effect model.

MAIN RESULTS

Six studies fulfilled the inclusion criteria. The total number of participants was 254, of whom 127 were allocated to placebo and 127 to antifibrinolytic drugs. Aprotinin, tranexamic acid and aminocaproic acid were evaluated in two studies each. All studies had placebo as the control group intervention. There were no deaths or any serious adverse events in any study, in either the active or the control group. The risk of being transfused was similar in patients receiving antifibrinolytic drugs or placebo. Antifibrinolytics drugs decreased the amount of blood transfused by 327 ml (95% CI -469.04 to -185.78) and the amount of blood loss by 427 ml (95% CI -602.51 to -250.56). There was no indication of publication bias, however, we cannot rule it out due to the small number of studies included.

AUTHORS' CONCLUSIONS

The effect of antifibrinolytic drugs on mortality could not be assessed. Antifibrinolytic drugs reduced blood loss and the amount of blood transfused in children undergoing scoliosis surgery; however, their effect on the number of children requiring blood transfusion remains unclear. Aprotinin, tranexamic acid and aminocaproic acid seem to be similarly effective.

Efficacy of aprotinin as a blood conservation technique for adult deformity spinal surgery: a retrospective study

STUDY DESIGN

A retrospective study that involved a total of 82 adult deformity patients who underwent spinal fusion surgery with instrumentation of 6 or more levels.

OBJECTIVE

The purpose of this study is to assess the efficacy and safety of aprotinin in reducing blood loss in adult spinal deformity patients.

SUMMARY OF BACKGROUND DATA

Aprotinin is an antifibrinolytic agent, which has been proven to be effective as a blood-conserving agent in cardiac surgery. This study focused specifically on adult spine deformity patients.

METHODS

This retrospective study analyzed a total of 82 adult deformity patients (patients with diagnosis of adult scoliosis and kyphosis) who underwent spinal fusion surgery with instrumentation of 6 or more levels. Forty-one patients who received aprotinin were compared with a control group of 41 patients who did not receive aprotinin. Specific surgical outcome parameters and postoperative complications were assessed.

RESULTS

The average age of the patients was 47 years and 41 years for the aprotinin group and the control group respectively. Thirty-nine percent of cases and 44% of controls had staged anterior/posterior fusion surgery, 39% of cases and 41% of controls underwent single stage posterior fusion surgery and the remaining 27% of cases and 15% of controls had same day anterior and posterior fusion surgery. The average number of levels fused and instrumented was 11.2 for the aprotinin group and 10.7 for the control group. The differences in mean blood loss and blood returned by cell-saver were statistically significantly lower in the aprotinin group (1324 mL vs. 2113 mL; P = 0.005 and 390 mL vs. 657 mL; P = 0.003). The amount of drainage after surgery was similar (1421 mL vs. 1388 mL; P = 0.982). The aprotinin group received an average of 2.73 units of blood. This was significantly lower than the average 5.02 units that the controls received (P = 0.003). The rate of complications was comparable and no allergic reaction to aprotinin was noted. One case exhibited a transitory elevation of blood urea nitrogen/creatinine which resolved before discharge.

CONCLUSION

The results of our study suggest that the administration of aprotinin is a safe and effective method to reduce blood loss and to decrease the need for transfusions without increasing risk of complication in the younger patients in relatively good general health undergoing spinal deformity surgery requiring 6 or more levels of fusion.

Effect of fibrin sealant on drain output and duration of hospitalization after multilevel anterior cervical fusion: a retrospective matched pair analysis

STUDY DESIGN

Retrospective matched pair analysis.

OBJECTIVE

To determine if fibrin sealant can decrease postoperative drain output and length of stay (LOS) after multilevel anterior cervical fusions.

SUMMARY OF BACKGROUND DATA

Despite careful hemostasis, bleeding after anterior cervical fusion can occur and may be life threatening. Although fibrin sealants are commonly used for hemostasis, no studies have been published on the efficacy of these products in achieving hemostasis after anterior cervical surgery.

METHODS

A retrospective age-, gender-, and fusion level-matched pair analysis was performed on 30 pairs of patients who underwent anterior cervical fusion >or= 3 levels. In the study group, after adequate hemostasis was obtained, before wound closure 2.0 mL of fibrin sealant was applied as a fine aerosolized spray over and around the plate/fusion sites and the soft tissues to seal the main operative field. A deep drain was used in all patients. Total drain output, time for the drainage to decrease to <or=20 mL per 8 hours shift, LOS, and number of readmissions were determined and analyzed by experienced and independent spine surgeons.

RESULTS

Total drain output averaged 47 mL in the study group and 98 mL in the control group (P < 0.0001). Time for the drainage to decrease to <or=20 mL per shift averaged 17 hours (range, 8-29 hours) in the study group and 24 hours (range, 7-43 hours) in the control group (P = 0.0054). LOS averaged 1.2 days (range, 1-4 days) in the study group and 2.1 day (range, 1-5 days) in the control group (P < 0.0001). Two patients were readmitted within 4 days of discharge in each group because of swallowing difficulty, dyspnea, or pneumonia (P = 1.000). There were no adverse reactions attributable to the fibrin sealant.

CONCLUSION

Application of fibrin sealant at the end of multilevel anterior cervical fusion can significantly decrease postoperative drain output and LOS.

Efficacy of preoperative erythropoietin administration in pediatric neuromuscular scoliosis patients

STUDY DESIGN

This is a retrospective cohort study examining 61 patients with neurogenic scoliosis who underwent anterior and/or posterior spinal instrumentation at the age of 18 and younger.

OBJECTIVE

The purpose of this study is to investigate this finding further by analyzing the effect of recombinant human erythropoietin (rhEPO) on hematocrit, transfusion and complication rates, and the length of intensive care unit (ICU) days in patients with neurogenic scoliosis.

SUMMARY OF BACKGROUND DATA

The preoperative use of rhEPO has been shown to decrease perioperative transfusion requirements in many adult and pediatric patients. A recent study at our institution demonstrated the efficacy of rhEPO in pediatric idiopathic scoliosis patients, but suggested the possibility of an "erythropoietin resistance" in the pediatric neurogenic scoliosis population.

METHODS

The patients' age at the time of surgery, gender, Cobb angle, erythropoietin administration and dosage, hematocrit levels, type of surgery, intraoperative blood loss, duration of surgery, number of vertebrae fused, comorbidities, complications, transfusion status, and the length of ICU days were collected.

RESULTS

Thirty-five (57.3%) children received preoperative rhEPO, whereas 26 patients (42.7%) did not receive rhEPO. The mean preoperative and discharge hematocrit levels in the patients treated with rhEPO were significantly higher than the non-rhEPO group (P = 0.05). There were no significant difference in likelihood of transfusion, complications, and the length of ICU days between the rhEPO and the non-rhEPO groups. A multivariate analysis demonstrated that the number of fused vertebral levels maintained its significance (P = 0.044) and surgical time had a trend toward significance (P = 0.051) in predicting likelihood of transfusion.

CONCLUSION

The use of rhEPO effectively stimulated erythropoiesis in these patients and yet demonstrated no significant clinical benefit in reducing the likelihood of transfusion in neurogenic patients in this study. More research is necessary to design a transfusion risk reduction protocols that will minimize the exposure of neurogenic scoliosis patients to allogeneic blood products.

Aprotinin may decrease blood loss in complex adult spinal deformity surgery, but it may also increase the risk of acute renal failure

STUDY DESIGN

Matched cohort comparison.

OBJECTIVE

This study examines the potential for aprotinin to conserve blood in adults undergoing long thoracolumbar deformity procedures and characterizes patients at risk for acute renal failure.

SUMMARY OF BACKGROUND DATA

Aprotinin has been shown to reduce intraoperative blood loss and reduce transfusion requirement in pediatric spine and cardiac surgery populations. Previous literature (before 2006) has not reported acute renal failure as a potential complication. This study was designed to examine the efficacy of aprotinin in reducing operative blood loss following long spinal arthrodesis in adult spinal deformity patients and to analyze complications.

METHODS

Adult spinal deformity patients undergoing long spinal arthrodesis at 1 institution between 2001 and 2005 were analyzed. Patients were matched according to age and type of procedure performed. Forty patients received high-dose aprotinin (Group A) intraoperatively, and 41 patients matched as controls (Group NA) received no aprotinin. Outcome variables included intraoperative blood loss, intraoperative transfusion requirement, early postoperative blood loss and transfusion requirement, and postoperative complications.

RESULTS

Average blood loss for Group A was 906 mL and 1.3 L for Group NA. The difference was statistically significant with a P < 0.05. Complications seen in Group A included 4 cases of acute renal failure requiring dialysis and 1 deep venous thrombosis. In Group NA, there was only 1 case of acute renal failure (presumed to be secondary to inadvertent gentamycin overdose) and 1 case of pulmonary embolus. The 4 Group A patients with acute renal failure were female, 61 to 73 years of age, with various comorbidities. All required inpatient hemodialysis. Three averaged 2 months of continued outpatient dialysis before resolution of renal compromise while 1 patient is on chronic dialysis.

CONCLUSION

In long spinal arthrodesis for complex adult spinal deformity surgery, aprotinin does reduce intraoperative blood loss, but may increase the risk of acute renal failure, especially in women over the age of 60.

Aprotinin in Major Orthopedic Surgery: A Systematic Review of Randomized Controlled Trials

Aprotinin therapy is a promising strategy for reducing blood loss and blood transfusion requirements. The efficacy and safety of aprotinin in orthopedic surgery, however, remain controversial. We searched electronic databases for randomized controlled trials on the efficacy and safety of the use of aprotinin in orthopedic surgery. Thirteen trials that included a total of 506 patients who underwent major orthopedic surgery were analyzed. The pooled intraoperative and perioperative blood loss was significantly less in the aprotinin-treated patients than in the control patients (weighted mean difference [WMD] for intraoperative blood loss = -229 mL, 95% confidence interval [CI] = -367 to -91 mL, P = 0.0011; WMD for perioperative blood loss = -557 mL; 95% CI = -860 to -254 mL; P < 0.0001). The pooled amounts of red blood cell (RBC) units (U) transfused intraoperatively and perioperatively were significantly less in the aprotinin-treated patients than in the control patients (WMD for intraoperative RBC U = -1.1 U; 95% CI = -1.7 to -0.4 U; P = 0.0001; WMD for perioperative RBC U = -1.1 U; 95% CI = -1.7 to -0.5 U; P < 0.0001). Aprotinin was not associated with an increased incidence of deep vein thrombosis (odds ratio = 0.39; 95% CI = 0.14 to 1.05, P = 0.061). The authors conclude that aprotinin reduces the intraoperative and perioperative blood loss and allogeneic blood transfusion requirement and may not be associated with increased risk of deep vein thrombosis in the presence of pharmacological or mechanical prophylaxis in patients undergoing major orthopedic surgery.

A direct antifibrinolytic agent in major orthopedic surgery

Aprotinin is a potent pharmacological agent that reduces bleeding. In current surgical practices, the rate of blood transfusions has decreased with the use of aprotinin. Recently, studies using aprotinin have been conducted in orthopedic surgery. Several trials have been performed in patients undergoing total hip replacement and total knee replacement. Aprotinin moderately decreased blood loss in these patients. When aprotinin was used in patients with a high-risk of bleeding (ie, patients with cancer, sepsis, or undergoing reoperation), potent hemostatic activity occurred and the rate of blood transfusions significantly decreased. No increase in deep vein thrombosis and pulmonary embolism was observed. One adverse effect was the potential occurrence of an anaphylactoid reaction. Prophylactic administration of aprotinin should be considered in extensive spine surgery and in high-risk orthopedic operations. The decision to use aprotinin can be guided by a risk/benefit analysis.

Aprotinin in spine surgery: review of the literature

Based on a literature review, this article evaluates the efficacy of aprotinin to limit blood transfusion during spine surgery. Most prospective studies confirm this effect. However, broader studies are required to evaluate adverse effects. Severe complications are rarely, if ever, reported. Given the small size of most samples, complications are expected because of the widespread use of the drug. The cost of the medication has to be balanced with the cost of blood transfusion. A careful use of aprotinin allows a surgeon dealing with high-risk patients to avoid or limit the use of transfusions. For patients who are not high-risk, aprotinin should be avoided until other questions are answered.