Modified Hidden Blood Loss Based on Drainage in Posterior Surgery on Lumbar Stenosis Syndrome with Rheumatoid Arthritis

Assessment of Hidden Blood Loss in Spinal Metastasis Surgery: A Comprehensive Approach with MRI-Based Radiomics Models

BACKGROUND

Patients undergoing surgery for spinal metastasis are predisposed to hidden blood loss (HBL), which is associated with poor surgical outcomes but unpredictable.

PURPOSE

To evaluate the role of MRI-based radiomics models for assess the risk of HBL in patients undergoing spinal metastasis surgery.

STUDY TYPE

Retrospective.

SUBJECTS

202 patients (42.6% female) operated on for spinal metastasis with a mean age of 58 ± 11 years were divided into a training (n = 162) and a validation cohort (n = 40).

FIELD STRENGTH/SEQUENCE

1.5T or 3.0T scanners. Sagittal T1-weighted and fat-suppressed T2-weighted imaging sequences.

ASSESSMENT

HBL was calculated using the Gross formula. Patients were classified as low and high HBL group, with 1000 mL as the threshold. Radiomics models were constructed with radiomics features. The radiomics score (Radscore) was obtained from the optimal radiomics model. Clinical variables were accessed using univariate and multivariate logistic regression analyses. Independent risk variables were used to build a clinical model. Clinical variables combined with Radscore were used to establish a combined model.

STATISTICAL TESTS

Predictive performance was evaluated using area under the curve (AUC), accuracy, sensitivity, specificity, and F1 score. Calibration curves and decision curves analyses were produced to evaluate the accuracy and clinical utility.

RESULTS

Among the radiomics models, the fusion (T1WI + FS-T2WI) model demonstrated the highest predictive efficacy (AUC: 0.744, 95% confidence interval [CI]: 0.576-0.914). The Radscore model (AUC: 0.809, 95% CI: 0.664-0.954) performs slightly better than the clinical model (AUC: 0.721, 95% CI: 0.524-0.918; P = 0.418) and the combined model (AUC: 0.752, 95% CI: 0.593-0.911; P = 0.178).

DATA CONCLUSION

A radiomics model may serve as a promising assessment tool for the risk of HBL in patients undergoing spinal metastasis surgery, and guide perioperative planning to improve surgical outcomes.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Utility of postoperative laboratory testing after posterior spinal fusion for adolescent idiopathic scoliosis

PURPOSE

With advancements to blood management strategies, risk of perioperative transfusion following surgical treatment of adolescent idiopathic scoliosis (AIS) has diminished. We hypothesize that routine laboratory testing on postoperative-day 1 (POD1) and beyond is unnecessary. The purpose of this study is to determine necessity of POD1 labs, particularly hematocrit and hemoglobin levels, following surgical management of AIS.

METHODS

We performed a retrospective cohort study of consecutive AIS patients aged 11-19 who underwent posterior spinal fusion (PSF) at a single institution. Univariable logistic regression was utilized to determine factors associated with hematocrit ≤ 22% on POD1 or a postoperative transfusion. Firth's penalized logistic regression was used for any separation in data. Youden's index was utilized to determine the optimal point on the ROC curve that maximizes both sensitivity and specificity.

RESULTS

527 patients qualified for this study. Among the eight total patients with POD1 hematocrit ≤ 22, none underwent transfusion. These patients had lower last intraoperative hematocrit levels compared to patients with POD1 hematocrit > 22% (24.1% vs 31.5%, p < 0.001), and these groups showed no difference in preoperative hematocrit levels (38.2% vs 39.8%, p = 0.11). Four patients underwent postoperative transfusion. Both preoperative hematocrit levels (34.0% vs 39.9%, p = 0.001) and last intraoperative hematocrit levels (25.1% vs 31.4%, p = 0.002) were lower compared to patients without transfusion. Intraoperative hematocrit < 26.2%, operative time of more than 35.8 min per level fused, or cell salvage > 241 cc were significant risk factors for postoperative transfusion.

CONCLUSION

Transfusion after PSF for AIS is exceedingly rare. POD1 labs should be considered when last intraoperative hematocrit < 26%, operative time per level fused > 35 min, or cell salvage amount > 241 cc. Otherwise, unless symptomatic, patients do not benefit from postoperative laboratory screening.

Risk Factors of Total Blood Loss and Hidden Blood Loss in Patients with Adolescent Idiopathic Scoliosis: A Retrospective Study

Objectives

To investigate the risk factors of total blood loss (TBL) and hidden blood loss (HBL) in adolescent idiopathic scoliosis (AIS) patients undergoing posterior orthopedic surgery.

Methods

The AIS patients who visited department of spine surgery between January 2015 and December 2020 were retrospectively reviewed. Those with a history of posterior orthopedic surgery for AIS were identified, and their clinical data were collected. Gross formula was used to calculate the TBL and HBL. SPSS 20.0 was used for statistical analysis. The potential risk factors of TBL and HBL were assessed by independent t-test or univariate analysis. The risk factors of TBL and HBL were determined by multiple linear regression.

Results

A total of 114 patients were included in this study. Operative time (P < 0.001), postoperative platelets (PLT) (P = 0.001), the number of surgical fixation segments (P < 0.001), implanted screws (P < 0.001), hospital stay (P = 0.006), type of scoliosis (P < 0.001), and correction angle of scoliosis (P = 0.063) were the potential risk factors of TBL. Operative time (P < 0.000), postoperative PLT (P = 0.095), the number of surgical fixation segments (P < 0.001), implanted screws (P < 0.001), type of scoliosis (P < 0.001), correction angle of scoliosis (P = 0.073), and total blood volume (P = 0.098) were the potential risk factors of HBL. Multiple linear regression analysis showed that operative time (P = 0.003) and the number of surgical fixation segments (P = 0.014) were risk factors of TBL, while the number of surgical fixation segments (P = 0.004) was a risk factor of HBL.

Conclusions

In AIS patients undergoing posterior internal fixation surgery, the operative time and the number of surgical fixation segments are risk factors of TBL, and the number of surgical fixation segments is a risk factor of HBL. Surgeons need to consider these factors when making surgical strategies for AIS patients.