Can Preoperative Sex-Related Differences in Hemostatic Parameters Predict Bleeding in Orthognathic Surgery?

The use of an ultrasonic curettage device in orthognathic surgery decreases surgery-related blood loss

Objective

This study aimed to compare the use of a powered instrument (PI) and ultrasonic curettage device (ULCD) with intraoperative blood loss (IOBL), drain volume (DV), calculated blood loss (CBL), and hidden blood loss (HBL) in orthognathic surgery.

Methods

We included 163 patients who underwent bimaxillary surgery in our department. CBL was calculated from the preoperative and postoperative hemoglobin levels using the "hemoglobin balance method." CBL is an indicator of the amount of perioperative blood loss. HBL was calculated by subtracting IOBL and DV from CBL.

Results

The PI group consisted of 61 patients (17 males and 44 females, age: 24.9 ± 9.5 years), and the ULCD group consisted of 102 patients (40 males and 62 females, age: 23.1 ± 7.8 years). In the PI group, the median IOBL, DV, CBL, and HBL were 540.0 (interquartile range [IQR] 380.0-670.0), 113.0 (IQR 77.0-147.0), 1000.0 (IQR 751.4-1248.6), and 285.8 (IQR 151.0-476.4) ml, respectively. In the ULCD group, the median IOBL, DV, CBL, and HBL were 327.5 (IQR 200.0-455.0), 105.5 (IQR 75.3-136.0), 759.5 (IQR 594.9-944.2), and 294.2 (IQR 120.8-456.9) ml, respectively. IOBL and CBL were significantly reduced with ULCD use, but no significant differences were observed in DV and HBL.

Conclusions

This study showed that IOBL decreased with ULCD use, resulting in a decrease in CBL. Conversely, bleeding parameters (DV and HBL), which reflect the amount of bleeding that occurs after wound closure, did not show a decrease with ULCD use.

Performance of Artificial Intelligence Models Designed for Diagnosis, Treatment Planning and Predicting Prognosis of Orthognathic Surgery (OGS)—A Scoping Review

The technological advancements in the field of medical science have led to an escalation in the development of artificial intelligence (AI) applications, which are being extensively used in health sciences. This scoping review aims to outline the application and performance of artificial intelligence models used for diagnosing, treatment planning and predicting the prognosis of orthognathic surgery (OGS). Data for this paper was searched through renowned electronic databases such as PubMed, Google Scholar, Scopus, Web of science, Embase and Cochrane for articles related to the research topic that have been published between January 2000 and February 2022. Eighteen articles that met the eligibility criteria were critically analyzed based on QUADAS-2 guidelines and the certainty of evidence of the included studies was assessed using the GRADE approach. AI has been applied for predicting the post-operative facial profiles and facial symmetry, deciding on the need for OGS, predicting perioperative blood loss, planning OGS, segmentation of maxillofacial structures for OGS, and differential diagnosis of OGS. AI models have proven to be efficient and have outperformed the conventional methods. These models are reported to be reliable and reproducible, hence they can be very useful for less experienced practitioners in clinical decision making and in achieving better clinical outcomes.

Gender-specific differences in haemostatic parameters and their influence on blood loss in bimaxillary surgery

Objective

The objectives of this prospective cohort study were to establish gender-related differences in blood loss and haemostatic profiles associated with bimaxillary surgery. In addition, we aimed to identify if any gender differences could be established which might help predict blood loss volume.

Materials and methods

Fifty-four patients (22 males; 32 females) undergoing bimaxillary surgery for skeletal dentofacial deformities were eligible for inclusion. Blood samples were taken 1 day preoperatively and 48 h postoperatively for detailed gender-specific coagulation analysis incorporating global coagulation assays (endogenous thrombin potential) and specific coagulation parameters. Blood loss was measured at two different time points: (1) the end of surgery, visible intraoperative blood loss (IOB) using ‘subtraction method’; and (2) 48 h postoperatively perioperative bleeding volume (CBL-48 h) using ‘haemoglobin-balance method’ and Nadler’s formula. Correlation and regression analyses were performed to identify relevant parameters affecting the amount of blood loss.

Results

Significant differences in IOB and CBL-48 h were observed (p < 0.001). Men had higher IOB versus women, lacking statistical significance (p = 0.056). In contrast, men had significantly higher CLB-48 h (p = 0.019). Reduced CBL-48 h was shown to be most closely associated with the level of Antithrombin-III being decreased in females.

Conclusions

Male gender is associated with higher IOB and CBL-48 compared with females. Gender does not affect IOB regarding haemostatic profile but does correlate strongly with procedure length. Conversely, CBL-48 is closely associated with gender-specific imbalances in the anticoagulant system.

Clinical relevance

Knowledge of gender-related differences will help clinicians establish predictive factors regarding excessive blood loss in orthognathic surgery and identify at-risk patients.

Predictors of Blood Loss During Orthognathic Surgery and the Need for Pre-Deposit Autologous Blood Donation

ABSTRACT

The aim of this study was to identify the clinico-laboratory predictors of relative blood loss (RBL) during orthognathic surgery and determine the need for predeposit autologous blood donation (PABD) for the surgery. Using a retrospective study design, 297 patients who underwent bimaxillary orthognathic surgery between 2016 and 2020 were enrolled. To investigate patient-specific risk factors, we calculated the allowable blood loss (ABL) for each patient and RBL as the ratio of estimated intraoperative blood loss (EIBL) to ABL. The correlations between the clinico-laboratory variables and EIBL and RBL were analyzed using stepwise multivariate regression analysis, and independent t test and one-way ANOVA were performed.There was no significant difference in transfusion rate between the PABD group (N = 202/279) and non-PABD group (N = 77/279) (P = 0.052). Sex (P < 0.001), body mass index class (P = 0.001), operative time (P < 0.001), and baseline hematocrit (P < 0.001) were significant predictors of EIBL and RBL. EIBL exceeded ABL in only 2 patients. The significant factors of RBL in orthognathic surgery were hematocrit, body mass index, and operative time. Clinicians should be more careful about bleeding in patients with low baseline hematocrit level or high body mass index, or those expected to undergo prolonged surgeries owing to a complicated surgical plan. The need for PABD before orthognathic surgery is low.

Determination of blood loss in bimaxillary surgery: does the formula and the time point affect results?

The amount of blood loss determined in orthognathic surgery differs greatly among studies. This can be attributed to the inhomogeneity in study cohorts analysed, but may also be a result of the varying methodologies used for blood loss determination. However, this has yet to be explored. Thus, the aim of this study was to investigate the extent to which the formula and time point used to measure blood loss affect the blood loss volume, determined in a homogeneous cohort undergoing bimaxillary surgery. Blood loss was calculated at 24 and 48 hours postoperatively using the haemoglobin balance method and the formula of Hurle et al. The estimated total blood volume was established based on the formulae of Nadler et al. and Choi et al. Differences in blood loss volume with respect to time point and formula were analysed and compared. Fifty-four patients were included in the final analysis. Statistically significant differences in blood loss were observed: a significant increase in the blood loss volume from 24 hours to 48 hours postoperatively was detected. When comparing the formulae used, blood loss differed significantly at 24 hours after surgery; however no such difference resulted at 48 hours postoperatively. These findings imply that the time point of measuring blood loss is highly relevant, whereas the formulae applied seem to have less of an impact on the blood loss volumes calculated.

Is there a hidden blood loss in orthognathic surgery and should it be considered? Results of a prospective cohort study

The aim of this prospective observational study was to investigate the parameter 'hidden blood loss' (HBL) in the context of orthognathic surgery, incorporating undetected bleeding volumes occurring intra- and postoperatively. Orthognathic bleeding volumes were recorded at three different time points. At the end of the operation the visible intraoperative blood loss (VBL) was measured. Additionally, the perioperative blood loss was calculated 24 h and 48 h postoperatively using the 'haemoglobin balance method'. Analysis of the HBL was based on the difference between the visible intraoperative blood loss (VBL) and calculated blood loss (CBL), determined 48 h after surgery. 82 patients (male 33, female 49) were included in this study, of whom 41 underwent bimaxillary surgery and of whom 41 underwent Bilateral Sagittal Split Osteotomy (BSSO). Statistically significant differences with reference to the absolute bleeding volumes were found when comparing the two treatment modalities. In terms of HBL, a bleeding volume of 287.2 ml (±265.9) in the bimaxillary group and 346.9 ml (±271.3) in the BSSO cohort was recorded. This accounted for 32.2% (bimaxillary surgery) and 62.6% (BSSO) of the CBL after 48 h (BIMAX vs. BSSO, p < 0.001). HBL is a valuable adjunct to record within the perioperative management of orthognathic surgery to further improve patient safety and postoperative outcomes.