Pre Incision HCT

        Pre-donation of autologous blood prior to spine fusion for adolescent idiopathic scoliosis (AIS) has been used in deformity surgery. The eRect of pre-donation on pre-operative hematocrit (Hct) remains debated. Multiple factors may inQuence pre-operative Hct including intravascular volume status, patient factors, and timing of pre-operative blood donation. The purpose of this study was to determine if pre-donation signiPcantly lowers pre-incision Hct in AIS patients.

        A retrospective cohort study of a Level-1 prospective randomized trial was conducted. 125 patients from the ho-mogeneous population were included. AIS patients undergoing a posterior only spinal fusion for AIS were separat-ed into two groups based on their pre-operative blood donation history. Demographic variables, pre-incision Hct, and transfusion rates were compared between the two groups using the Student's T-test. Pre-donation and non pre-donation groups had 28 and 97 patients, respectively. Pre-donation group was 75% fe-male (21F, 7M) and non pre-donation group was 78% female (76F, 21M). There was no diRerence between pre-donation and non pre-donation groups in mean age (15.6 ± 2.2 vs 14.8 ± 2.2, p=0.081), BMI (23.1 ± 4.2 vs 21.7 ±5.3, p=0.219), and pre-incision Hct (32.8 ± 3.4 vs 33.8 ± 3.1, p=0.628). The overall transfusion rates were equiva-lent (32.1± 48.0% vs 25.8 ± 44.0%, p=0.509), however, the rate of allogenic transfusion for the pre-donation group was signiPcantly lower (3.6 ± 18.9% vs 25.8 ± 44.0%, p=0.011).

        This study supports the use of pre-donation for AIS, without a signiPcant drop in pre-incision Hct. Patients that donate are also much less likely to be exposed to allogenic blood. There may be a surgeon bias to recommend pre-donation in patients with a larger BMI and older age. Future studies are needed from a larger population of pa-tients including those with non-AIS pathology. Level of evidence: Level III.

keywords: autologous blood, adolescent idiopathic scoliosis, spine surgery, blood transfusion, hematocrit

volume 10 article 27 doi: 10.14444/3027

        Pre-donation of autologous blood (PD) prior to spine fusion for adolescent idiopathic scoliosis (AIS) in conjunction with other blood conservation tech- niques have been frequently used in spinal deformity surgery. PD has been extensively studied in non-spinal orthopaedic procedures and found to lower the risk of allogenic blood transfusions in hip and knee replacement surgeries.1-3 PD has become increasingly common for elective spine surgery patients and can lead to a decrease in the likelihood of homologous blood transfusion.4-6

       Despite this in-creasing use, there exists a paucity of research on its
eScacy and indications,7 particularly with AIS surgery. In addition, parents of AIS patients are especially interested in reducing the potential for allogenic blood transfusion. In recent years this has driven surgeons to have greater focus on minimizing this risk through a variety of techniques including reduction of mean arterial pressure, meticulous surgical technique in conjunction with reduced operative
time, and utilization of antiPbrinolytic medications.8 Various viruses such as HIV and Hepatitis B and C progressively contaminated donated allogenic blood in the 1980s. Therefore, healthcare professions sought to decrease the risk of exposure to contaminated products and in the late 1980s and 1990s many surgeons used PD for surgical procedures with large volumes of expected blood loss, such as in spinal
surgery. 9-12 Due to prohibitive costs of PD programs and decreased exposure risks from implementation of screening protocols PD began to fall out of favor. Consequently, the practice of autologous blood transfusion for spine surgeries decreased in many prac- tices. However many of these conclusions have been based on cost analyses studies from the 1990s.11 Pediatric spinal surgery is associated with signiPcant blood loss; reported to vary from 57 to 350 mL/level fused, depending on surgical technique and instrumentation utilized.13

         Greater blood loss increases the necessity for transfusion, and consequently the exposure to more blood products with the potential for disease transmission or transfusion reactions and increased surgical site infections.14,15 Using the National Inpatient Database it is estimated that 2.71 million spinal fusions were performed in the United States from 2002 to 2009,16 of which 30% received blood transfusions.4,17 Although serious complications of allogenic transfusions are uncommon, the high rate of blood transfusions necessitate investigating alternative options. The eRect of autologous donation on pre- and post-operative hematocrit (Hct), and transfusion rates remains debated in the setting of AIS fusion surgery.Universally accepted indications to pre-donate in spine patients do not exist, particularly with AIS patients. Multiple factors may inQuence preoperative Hct including intravascular volume status, patient factors, and timing of pre-operative donation. This study aims to determine if AIS patients that predonate autologous blood have a signiPcantly lower pre-incision Hct, post surgical Hct, and transfusion rates compared to AIS patients that did not pre-donate blood. We retrospectively examined a cohort of AIS patients undergoing a posterior only spinal fusion from a prospective randomized trial (Figure 1).During the prospective trial 125 patients were randomized to Tranexamic acid (TXA), Aminocaproic acid (EA-CA), or Saline (control) for surgery from January 2009 to January 2011.

        Level-1 data from this homogeneous population minimizes the eRect of confounding variables. For the current study the 125 patients were separated into two groups based on their pre-operative blood donation history and compared in terms of their pre-incision Hct. All patients in the prospective study had a complete blood count drawn just prior to incision.8 Of the 125 patients enrolled in that study: 28 patients donated blood prior to surgery (PD group), 97 patients did not pre-donate blood (Non-PD group). doi: 10.14444/3027 International Journal of Spine Surgery 2 / 7 There is no age limitation to pre-donate blood at the study institution. Absoluteexclusion criteria for pre- donations include: active infection and weight less than 100 lbs. Relative exclusion criteria include: cardiac conditions, pulmonary disease, current antico-agulant therapy, and a history of cerebrovascular disease, or seizures. Relative exclusion criteria are considered on a case-by-case basis. Patients may donate blood every four to seven days, and up to three days before surgery with up to two units donated in the month prior to surgery. Patients are instructed to avoid acetaminophen, aspirin and alcohol consumption for 48 hours prior to donation.

        Posterior spinal fusion was achieved by careful dissection of the paraspinal musculature from the spinous process, lamina, and facet. Soft tissue releases and ponte osteotomies on the concavity were performed to increase Qexibility followed by pedicle screw Pxation. (Figure 1 and Figure 2) Local autologous and allograft bone graft was used to achieve bony fusion. Sub-fascial hemovac drains were routinely placed at the wound site during closure and uniformly removed post-operatively when wound drainage was less than 40 ml per eight-hour shift. Transfusion was performed intraoperatively if a patient had a measured Hct of less than 25 with ongoing bleeding, and post-operatively if a symptomatic patient had a Hct of less than 22. Demographic variables analyzed include age, BMI, gender, and estimated blood volume. Estimated blood volume was approximated as 80 mL/kg.18 The primary outcome measure was pre-incisional Hct. To insure the proportion of patients assigned to EACA, TXA and/or saline did not diRer between PD and non-PD groups a Pearson chi-squared test was performed. Additional outcome measures analyzed include peri-operative transfusion rate, length of hospitalization, estimated blood loss (EBL), and Hct on post-operative day (POD) 1 and 2. The eRects of Tranexamic acid (TXA), Aminocaproic acid (EA-CA), and Saline (control) were not analyzed as the primary outcome was pre-incisional Hct, and there were too few subjects to do a sub-analyses on secondary outcome measures. Outcome variables were statistically analyzed using SPSS software (SPSS, Inc.). Demographic variables and study outcomes were compared between the two groups using the Student’s T-test with statistical signiPcance was dePned as p < 0.05. The proportion of patients assigned to EACA, TXA and/or saline did not diRer between PD and non-PD groups (p=0.26). The PD group was 75% female (21F, 7M), and Non-PD group was 78% female (76F, 21M).

        The mean age of the PD group trends to a higher age (15.6 ± 2.2 vs 14.8 ± 2.2 years, p=0.081), although this was not statistically signiPcant. The BMI of the PD was slightly higher than Non-PD (23.1 ± 4.2 versus 21.7 ± 5.3, p=0.219), although this diRerence was not statistically signiPcant. The estimated blood volume for the patients that pre-donated was signiPcantly higher (4444 ± 1142 vs 3881 ± 1060, p=0.017). (Table 1) doi: 10.14444/3027 International Journal of Spine Surgery 3 / 7 Hct between the two groups (PD vs Non-PD) were equivalent at the three time points measured: The pre-incision Hct (32.8 ± 3.4 vs 33.8 ± 3.1, p=0.167), POD1 Hct (29.3 ± 4.7 vs 28.5 ± 3.4, p=0.333), POD2 Hct (28.2 ± 4.4 vs 27.3 ± 3.6, p=0.309), and change in Hct from pre-incision to POD2 (-3.6 ± 3.6 vs -5.3 ± 5.9, p=0.154) did not diRer signiPcantly (Table 2). The overall transfusion rate between the PD and Non-PD did not diRer signiPcantly (32.1 ± 48.0% vs 25.8 ± 44.0%, p=0.509). However, the rate of allogenic transfusion for the PD group was signiPcantly lower than the Non-PD group (3.6 ± 18.9% vs 25.8 ± 44.0%, p=0.011). Length of hospitalization did not diRer signiPcantly between PD and Non-PD (5.2 ± 0.8 days vs 5.5 ± 1.1, p=0.225).

        Therefore, patients who pre-donate blood are less likely to be exposed to allogenic blood, without increasing the risk of overall transfusion and without an increased length of hospitalization (Table 3). Patients who pre-donated blood trended towards losing less total blood intra-operatively (734 ± 734cc vs 938 ± 742cc, p=0.180), and less blood loss per level fused (77.8 ± 62.1cc vs 102.5 ± 65.7cc, p=0.079), although these trends were not statistically signiPcant. Interestingly, patients that pre-donated lost a signiPcantly smaller portion of their total estimated blood volume (17 ± 13% vs 25 ± 19%, p=0.012). (Table 4) Pre-donation prior to surgical procedures has the potential to minimize the risks of allogenic blood transfusions.4

         Allogenic transfusion is associated with potentially serious complications such as; incorrect blood component transfused (CMV+ blood to a CMV- patient), acute transfusion reactions, as well as transfusion-related acute lung injury. 19 Allogenic transfusion also increase the risk of infectious disease such as hepatitis B and C, HIV and nvCJD.19 Pre-donation has several limitation in major spinal surgery such as diSculty of predicting which patients require blood tranfusion,20,21 the high potential for wastage (up to 40% discarded autologous blood products),20 a high level of communication across a variety of specialties necessary for successful implementation, and its inavailability in emergency surgeries.4 With the exception of the estimated blood volume, the baseline demographic variables between the PD and non-PD groups were similar. Due to institutional policy, patients were excluded from pre-donation if they weighed less than 100 lbs. The signiPcantly larger estimated blood volume in the pre-donation group is therefore not surprising. Similarly, this exclusion criterion likely explains the trend towards larger BMI Group N Mean Age

BMI Gender (%female)
PD 28 15.6 ± 2.2 23.1 ± 4.2 75
NON-PD 97 14.8 ± 2.2 21.7 ± 5.3 78
p - 0.081 0.219 -

Group Pre-Incision
Hct
POD1
Hct
POD2
Hct

Change in Hct (Incision to POD2)
PD 32.8 ± 3.4 29.3 ± 4.7 28.2 ± 4.4 -3.6 ± 3.6
NON-
PD 33.8 ± 3.1 28.5 ± 3.4 27.3 ± 3.6 -5.3 ± 5.9
p 0.167 0.333 0.309 0.154

Group
Transfusion
Rate (%)
Allogenic Blood
Transfusion Rate (%) LOH (days)
PD 32.1 ± 48.0 3.6 ± 18.9 5.2 ± 0.8
NON-PD 25.8 ± 44.0 25.8 ± 44.0 5.5 ± 1.1
p 0.509 0.011 0.225

Group EBL (mL) EBV (mL) EBL/Levels fused EBL/EBV
PD 734 ± 734 4444 ± 1142 77.8 ± 62.1 0.17 ± 0.13
Non-PD 938 ± 742 3881 ± 1060 102.5 ± 65.7 0.25 ± 0.19
p 0.180 0.017 0.079 0.012
doi: 10.14444/3027

        International Journal of Spine Surgery 4 / 7 and age in the PD group. This data suggests that PD patients were comparable to Non-PD. One study by BrookPeld et al. has found the greatest drawback to the use of PD in major spine surgery is that it lowers preoperative hemoglobin level.20 Similarly, Kennedy et al. examined elective posterior lumbar spine surgery in adult patients and found PD induced preoperative anemia.7 The authors found preoperative Hct in patients who pre-donated was signiPcantly lower (39.8 ± 4.5 vs 41.6 ± 4.6, p<0.001).7 The PD group in the present study had an equivalent pre-incision Hct as compared to the Non-PD group. The predonation program, and mean time from pre-donation was unfortunately not available to compare among the present study, and Kennedy et al. and BrookPeld et al. While our study shows a contrasting result, it is important to recognize that AIS patients are a
generally healthy uniform population that is likely better able to compensate for the blood loss necessary for predonation. Perhaps these contrasting Pndings represent
an inherent diRerence in the populations analyzed. Kennedy et al. and BrookPeld et al. studied older populations. Therefore, the results of this study are best applied to a healthy population of adolescents or young adults. In the setting of posterior lumbar surgery Kennedy etal. found a lower transfusion threshold in PD than allogenic blood, likely due to the higher rate of preoperative anemia in the studied patient population or the belief that potential infectious complications from contaminated blood would be negligibile.7 This study found that PD group patients who donated oneand two units of blood were, respectively, 7.5 and 9 times more likely to be transfused within the Prst 24 hours than Non-PD patients.7 Conversely, a retrospective study by Solves et al. of patients undergoing major elective spine surgery found that pre-donation was eRective for reducing allogeneic transfusion rates in mostly young patients undergoing major elective spinal surgery (Odds Ratio = 0.077; 95% CI = 0.043-0.140).6 The present study found that pre-donation did not increase the risk of transfusion in the peri-operative period.

        The drastic reduction in the risk of allogenic transfusion seen as well is a result of the use of autogenic prior to the use of allogenic blood. These Pndings coincide with the Pnd-ings by Solves et al.6 This reduced rate of allogenic transfusion in patients who pre-donate, with no increased risk of overall transfusion risk eRectively reduces the potential for disease transmission or transfusion reactions.14 The present study did not investigate the eRects of instrumentation on transfusion rates or Hct, however Kennedy et al. found that pre-donation was signiPcantly more eScient in patients who underwent instrumented lumbar fusion than in patients with less complex surgery. 7 Cha et al. found that pre-donation decreased their risk of receiving allogeneic blood by 75% for non-instrumented fusions, and 50% for instrumented fusions in posterior lumbar decompression with fusion of up to three levels.21 This study concluded PD signiPcantly diminishes allogeneic blood usage in patients undergoing spinal fusion.21 This study is limited by its small sample size and inclusion of relatively few surgical and patient factors likely to inQuence blood loss including timing of predonation, and curve type. Furthermore, the diRerence in BMI between the two groups suggests there may be a surgeon bias to recommend pre-donation in patients with a larger BMI, although this diRerence was not signiPcant. This bias may be a function of longer surgery times required for patients with larger BMIs.

        Additionally the study did not track peri- and post-operative complications, and therefore dePnitive conclusions concerning reducing the rate of transfusion reactions and exposure to infectious diseases cannot be made. Another limitation of the current study is cost-analysis. Unfortunately the cost incurred for one unit of PD was not available at the studied institution. The cost eRectiveness of pre-donation has been previously discussed, however much of the literature that may have contributed to the decreased use of PD are cost analyses studies from the 1990s and early 2000s.11,21 For example, in 2002 Cha et al. concluded routine preoperative collection of autologous blood is not necessary before simple lumbar laminectomy without fusion despite reducing allogenic transfusionrate in lumbar laminectomy procedures because the donated blood is discarded in 80% of cases.21 Since Medicare does not reimburse for pre-donation22 the doi: 10.14444/3027 International Journal of Spine Surgery 5 / 7 cost of the surgery must be covered by insurance, or more frequently by the patient. One 2003 study analyzed the use of autologous pre-donated blood transfusion in surgery for scoliosis in 45 patients at one hospital in England.23 The authors concluded that autologous blood transfusion required extra time, personnel, resources and cost £28.88 ($47.15 USD) per patient more than allogenic transfusion.23 Additional concerns about unused autologous blood adding an unnecessary expense has been raised as well.21,24 To date the cost of a unit of allogenic blood is variable and institution dependent. The cost is also increased by the various tests and processing necessary for minimize patient risk. More recent literature supports the use of PD as a cost-eRective method. In 2004 Hardwhick et al. concluded PD to be similar in cost to allogenic blood in orthopaedic procedures, speciPcally in total hip replacement procedures.

        This study found the mean cost of one unit of PD to be $391 and one unit of allogeneic blood to be $514.25 These Pndings highlight the need for further research on the cost-eRectiveness of PD programs, particularly in the AIS population. This study’s strength is its inclusion of a homogenous population of AIS patients participating in a level-one study with a very speciPc transfusion trigger. Future studies are needed from a larger population of patients, including those with non-AIS pathology, to make more dePnitive suggestions on optimal protocol (timing, frequency and indications). Future studies will also be necessary to develop guidelines based on volume status, curve type and magnitude, planned procedure, and BMI. Queries of multi-center databases may oRer additional supportive evidence. Based on the Pndings of the current study, surgeons can consider pre-operative donation of autologous blood in patients undergoing planned AIS spine surgery without fear of signiPcantly decreasing the patient’s Hct at incision, or increasing the rate of overall transfusions. The decreased rate of allogenic transfusions would make this a safe and eRective alternative in patients that meet inclusion criteria for pre-donation programs. However the potential risks of allogenic or autologous blood transfusion, benePts and cost of PD must be thoroughly discussed with the patient prior to its utilization.

1. Bou Monsef J, Buckup J, Mayman D, Marx R, Ranawat A, Boettner F. Targeted preoperative autologous blood donation in total knee arthroplasty reduces the need for postoperative transfusion. HSS J. 2013;9(3):214-217. doi:10.1007/s11420-013-9346-8.

2. Oberhofer D, Sakić K, Janković S, Tonković D, Vrgoc G. [How to improve perioperative blood management in patients undergoing total hip or knee replacement surgery?]. Lijec̆nic̆ki Vjesn. 134(11-12):322-327. http://www.ncbi.nlm.nih.gov/
pubmed/23401978. Accessed January 20, 2016.

3. Billote DB, Glisson SN, Green D, Wixson RL. EScacy of preoperative autologous blood donation: analysis of blood loss and transfusion practice in total hip replacement. J Clin Anesth. 2000;12(7):537-542. doi:10.1016/S0952-8180(00)00213-0.

4. Kumar N, Chen Y, Nath C, Liu EHC. What is the role of autologous blood transfusion in major spine surgery? Am J Orthop (Belle Mead NJ). 2012;41(6):E89-E95.

5. Goodnough L, Marcus R. ERect of autologous blood donation in patients undergoing elective spine surgery. Spine (Phila Pa 1976). 1992.

6. Solves P, Carpio N, Moscardo F, et al. Results of a preoperative autologous blood donation program for patients undergoing elective major spine surgery. Transfus Apher Sci. July 2013:4-7. doi:10.1016/ j.transci.2013.06.016.

7. Kennedy C, Leonard M, Devitt A, Girardi FP, Cammisa FP. EScacy of preoperative autologous blood donation for elective posterior lumbar spinal surgery. Spine (Phila Pa 1976). 2011;36(26):E1736-E1743. doi:10.1097/BRS.0b013e3182194a42.

8. Verma K, Errico TJ, Vaz KM, Lonner BS. A prospective, randomized, double-blinded single-site control study comparing blood loss prevention of tranexamic acid (TXA) to epsilon aminocaproic acid (EACA) for corrective spinal surgery. BMC Surg. 2010;10:13. doi:10.1186/1471-2482-10-13.

9. Goodnough LT, Brecher ME. Autologous blood doi: 10.14444/3027 International Journal of Spine Surgery 6 / 7 transfusion. Intern Med. 1998;37(3):238-245.

10. Bernstein LH, Coles M, Viner N. Bridgeport Hospital autologous blood donation experience from 1992 to 1996. Yale J Biol Med. 1996;68(5-6):207-213. http://www.pubmedcentral.nih.gov/articleren-der.fcgi?artid=2588941&tool=p....

11. Roberts W a, Kirkley S a, Newby M. A cost comparison of allogeneic and preoperatively or intra-operatively donated autologous blood. Anesth Analg.
1996;83(1):129-133. http://www.ncbi.nlm.nih.gov/
pubmed/8659723.

12. Tulloh BR, Brakespear CP, Bates SC, et al. Autologous predonation, haemodilution and intraoperative blood salvage in elective abdominal aortic
aneurysm repair. Br J Surg. 1993;80(3):313-315.

13. Shapiro F, Sethna N. Blood loss in pediatric spine surgery. Eur Spine J. 2004;13 Suppl 1:S6-S17. doi:10.1007/s00586-004-0760-y.

14. Hu SS. Blood loss in adult spinal surgery. Eur Spine J. 2004;13 Suppl 1:S3-S5. doi:10.1007/s00586-004-0753-x.

15. Schwarzkopf R, Chung C, Park JJ, Walsh M, Spivak JM, Steiger D. ERects of perioperative blood product use on surgical site infection following thoracic and lumbar spinal surgery. Spine (Phila Pa1976). 2010;35(3):340-346. doi:10.1097/
BRS.0b013e3181b86eda.

16. Nandyala S V, Marquez-Lara A, Fineberg SJ, Singh R, Singh K. Incidence and risk factors for peri=operative visual loss after spinal fusion. Spine J. November 2013. doi:10.1016/j.spinee.2013.10.026.

17. Berenholtz SM, Pronovost PJ, Mullany D, et al. Predictors of transfusion for spinal surgery in Maryland, 1997 to 2000. Transfusion. 2002;42(2):183-189.

18. Yamamoto LG. Case Based Pediatrics for Medical Students and Residents. AuthorHouse; 2004.

19. Harrison E, Bolton P. Serious hazards of transfusion in children (SHOT). Paediatr Anaesth. 2011;21(1):10-13. doi:10.1111/j.1460-9592.2010.03474.x.

20. BrookPeld KF, Brown MD, Henriques SM, Buttacavoli FA, Seitz AP. Allogeneic transfusion after predonation of blood for elective spine surgery. Clin Orthop Relat Res. 2008;466(8):1949-1953. doi:10.1007/s11999-008-0306-4.

21. Cha CW, Deible C, Muzzonigro T, Lopez-Plaza I, Vogt M, Kang JD. Allogeneic transfusion require ments after autologous donations in posterior lumbar
surgeries. Spine (Phila Pa 1976). 2002;27(1):99-104.

22. American Medical Association. CPT® 2014 Professional Edition: Spiralbound. American Medical Association; 2014.

23. Ridgeway S, Tai C, Alton P, Barnardo P, Harrison DJ. Pre-donated autologous blood transfusion inscoliosis surgery. J Bone Jt Surg. 2003;85(7):1032-1036. doi:10.1302/
0301-620X.85B7.13466.

24. Lenke LGBKHS-MKHM. Wasting of preoperatively donated autologous blood in the surgical treatment of adolescent idiopathic scoliosis. Spine (PhilaPa 1976). 2006;31(20):2375-2380.

25. Hardwick ME, Morris BM, Colwell CW. Two-dose Epoetin Alfa Reduces Blood Transfusions Compared with Autologous Donation. Clin Orthop Relat Res. 2004;423(423):240-244. doi:10.1097/01.blo.0000130206.58617.9e. Anthony Boniello reports no relevant disclosures or COI; Thomas Errico reports no relevant disclosures
or COI; Baron Lonner reports no relevant disclosures or COI; Austin Peters reports no relevant disclosures or COI; Kushagra Verma reports no relevant disclosures or COI.
Anthony Boniello, Department of Orthopedic Surgery, Drexel College of Medicine, Hahnemann University Hospital, Philadelphia, PA. anthony.boniello@gmail.com
Published 16 August 2016.This manuscript is generously published free of
charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2016 ISASS. To see more or order reprints or permissions,
see http://ijssurgery.com.