Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Schwaiger, M.
Gender-related differences in blood parameters and their influence on the intraoperative blood loss in orthognathic surgery
Doktoratsstudium der Medizinischen Wissenschaft; Humanmedizin; [ Dissertation ] Medical University of Graz; 2021. pp. 148
[OPEN ACCESS]
FullText
- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Gary Thomas
- Wallner Jürgen
- Zemann Wolfgang
- Altmetrics:
- Abstract:
- Orthognathic surgical interventions are common maxillofacial procedures that aim to correct complex dentofacial deformities and concomitant skeletal malocclusion. These elective procedures follow highly standardised intraoperative protocols, which optimise patient safety and help to accurately administer a surgical plan. However, owing to the well-vascularised anatomy of the midface, blood loss remains among the major issues associated with orthognathic surgery. In this context, patient gender has frequently been highlighted as a crucial factor, with males associated with a higher surgical blood loss. Specific underlying mechanisms leading to these gender-related differences in orthognathic bleeding volumes have scarcely been investigated. Hence, the aim of this study was to analyse blood loss related to standardised orthognathic procedures with a special emphasis on patient gender. An additional aim was to ascertain gender-based differences in blood and haemostatic parameters and subsequently correlate these parameters with orthognathic blood loss. Healthy male and female individuals, scheduled to undergo bimaxillary surgery or bilateral sagittal split osteotomy (BSSO), were considered eligible for this study. Blood loss was standardly measured at three time points by two well-established approaches in the field of orthognathic surgery. Intraoperative blood loss (IOB) was determined using the subtraction method; perioperative blood loss was calculated 24- and 48-hours after surgery (CBL-24h; CBL-48h) by means of the ‘haemoglobin balance method’. All bleeding volumes determined were analysed according to the treatment modality applied and patient gender. Prior to surgery, a detailed coagulation analysis was performed comprising routine coagulation assays, global coagulation assays (endogenous thrombin potential) and specific haemostatic parameters. Relevant parameters were correlated with the intra- and perioperative blood loss (IOB and CBL-48h) to investigate the effect of gender-related differences in the haemostatic profile on a patient’s blood loss. A total of 103 patients (38 male, 65 female) were included in the final analysis, 54 of whom underwent bimaxillary surgery and on 49 of whom BSSO was performed. Regarding patient sex, no gender-specific differences in terms of the intraoperative blood loss (IOB) were detected. With reference to CBL-24h and CBL-48h, however, statistically significant differences in terms of the bleeding volumes were found, but, were confined to the bimaxillary-cohort. In more detail, CBL-48h in males was found to significantly outreach that associated with females (male 907.7ml ± 246.1 vs female: 730.8ml ± 274.5; p=0.019). Regarding the haemostatic parameters analysed, few significant gender-related differences were detected including the parameters 'activated partial thromboplastin time (aPTT)', 'Antithrombin III', 'endogenous thrombin potential (ETP-auc)' and 'coagulation factor IX'. A significant correlation between the level of Antithrombin III and CBL-48h in the bimaxillary-cohort (r=0.474; p=0.001) was found. Regarding the IOB, the length of the procedure was identified as most significantly affecting the amount of blood loss. Several parameters were identified as responsible for affecting the amount of blood loss, whereby patient gender was found to be less of a contributing factor than previously suggested. While the amount of intraoperative blood loss (IOB) related to orthognathic surgical procedures appeared to be significantly affected by the treatment modality applied together with the length of the procedure, patient gender and associated differences in the haemostatic profile were irrelevant in this context. In contrast, our findings indicate that gender-related peculiarities in the haemostatic cascade are most visible in the immediate postoperative period, where bleeding into tissue spaces as well as the maxillary sinuses is likely to pertain.