Analysis of risk factors for hidden blood loss in unilateral biportal endoscopic transforaminal lumbar interbody fusion

English Keywords:Lumbar degenerative diseases  Endoscopic fusion  Unilateral biportal endoscopic  Hidden blood loss  Risk factors

English Abstract:

  【Abstract】 Objectives: To observe the hidden blood loss after unilateral biportal endoscopic transforaminal lumbar interbody fusion(UBE-TLIF) and analyze its related risk factors. Methods: The clinical data of 59 patients who underwent UBE-TLIF for lumbar degenerative diseases(LDD) in our hospital from January 2020 to June 2021 were retrospectively analyzed. Data of general information such as age, gender, body mass index(BMI), learning curve, type of disease, and presence of hypertension and diabetes; surgery-related information such as lesion segment, operative time, visible blood loss, and American Society of Anesthesiologists(ASA) classification; and laboratory test data such as prothrombin time, activated partial thromboplastin time, platelets, fibrinogen, hemoglobin(Hb), and hematocrit(Hct) were collected. The total blood loss was calculated according to the Gross formula, and the hidden blood loss was calculated accordingly. One-way analysis of variance and Pearson correlation test were used to explore the correlation between patient characteristics and postoperative hidden blood loss. Multivariate linear regression analysis was used to determine the independent risk factors for postoperative hidden blood loss, and the receiver operating characteristic(ROC) curve of risk factors was constructed to analyze the predictive values of risk factors. Results: The operative time was 128.22±22.88min, total blood loss was 607.32±186.78ml, and the hidden blood loss was 393.83±173.42ml, accounting for (62.13±11.73)% of the total blood loss. Postoperative Hb and Hct were significantly lower than those before operation(P<0.05). One-way analysis of variance showed gender, (with or without)hypertension, (with or without)diabetes, surgical segment, and disease type were not significantly correlated with hidden blood loss(P>0.05), and the learning curve and ASA calssification were correlated with hidden blood loss(P<0.001). Pearson correlation analysis showed that age, BMI, prothrombin time, activated partial thromboplastin time, and platelets had no correlations with hidden blood loss(P>0.05), while operative time, and fibrinogen had correlations with hidden blood loss(P<0.001). Multiple linear regression analysis indicated that operative time(B=2.236, P<0.01), learning curve(B=-109.781, P<0.01), ASA classification(B=77.589, P<0.01), and fibrinogen(B=81.762, P<0.01) were independent risk factors for hidden blood loss. ROC curve displayed that the area under the ROC curve(AUC) of operative time for predicting severe hidden blood loss was 0.813(95%CI: 0.688-0.938, P<0.001), and the best cut-off point was 139.5min. The AUC of fibrinogen was 0.794(95%CI: 0.654-0.934, P<0.001), and the optimal cut-off point was 2.65g/L. Conclusions: There is a large hidden blood loss risk in the treatment of LDD by UBE-TLIF, which should be paid attention to in clinical practice. Operative time, learning curve, ASA classification, and fibrinogen are independent risk factors for postoperative hidden blood loss.