Influence of K-line on intraoperative and hidden blood loss in patients with ossification of the posterior longitudinal ligament when undergoing unilateral open-door laminoplasty

Abstract

Background The K-line is a virtual straight line that connects the midpoints of the anteroposterior spinal canal diameter from C2 to C7 on a cervical lateral X-ray film. Patients with cervical ossification of the posterior longitudinal ligament (OPLL), in which the peak of the OPLL exceeds the K-line (K-line [-]), are less likely to experience sufficient decompression after laminoplasty compared with patients for whom the OPLL does not exceed the K-line (K-line [+]). This retrospective study investigated the influence of K-line position relative to the OPLL on intraoperative and hidden blood loss during unilateral open-door laminoplasty for OPLL. Methods Data were retrospectively analyzed of 108 patients with OPLL who underwent unilateral open-door laminoplasty between April 2015 and March 2018. Patient cases were categorized as K-line (+) or (-). The evaluated perioperative parameters were haematocrit, haemoglobin, intraoperative and hidden blood loss, surgical time, postoperative drainage, and complications. Radiological parameters included ossification occupancy ratio and C2-7 lordosis. Results The K-line (+) and K-line (-) groups were statistically comparable with regard to age, gender, body mass index, OPLL classification, medication history, C2-7 lordosis, postoperative haemoglobin and haematocrit, postoperative drainage, hidden blood loss, and complications. The occupying ratio of the K-line (-) group was significantly greater than that of the K-line (+) group (49.5 ± 15.3% cf. 42.3 ± 10.1%; P = 0.006), and the intraoperative blood loss was also significantly higher (286 ± 110.5 mL cf. 205.5 ± 98.3 L, P = 0.003). The hidden blood loss of the K-line (-) group was higher than that of the K-line (+), but not significantly (295.5 ± 112.6 mL cf. 265.6 ± 103.8 mL; P = 0.072). Conclusion Intraoperative and hidden blood loss associated with unilateral open-door laminoplasty can be predicted by the spatial relationship of the K-line and osteophyte. This relationship is a simple and practical index that may help surgeons determine the appropriate surgical strategy for patients with OPLL.

Risk factors for perioperative hidden blood loss after one-segment posterior circumferential decompression surgery on thoracic ossification of the posterior longitudinal ligament: a finding of the double-layer sign on CT

“…In this study, we investigated OOR > 60% was an independent risk factor for HBL. High epidural pressure is an important risk factor for intraoperative blood loss [30]. Due to the existence of an ossi ed mass, the local venous re ux is not su cient, high venous pressure leads to thin wall of venous plexus, and the increase in epidural pressure will further lead to an increase in vascular tension in the surrounding tissues, ultimately increasing bleeding of the surrounding tissues during the operation.…”

Risk Factors for Significant Intraoperative Blood Loss during Anterior Cervical Decompression and Fusion for Degenerative Cervical Diseases

“…Demographic data, such as age; sex; smoking and trauma history; BMI; duration of disease; ASA classification; preoperative hemoglobin (Hb), hematocrit (HCT), and thrombocytocrit (PCT); preoperative prothrombin time (PT); INR; thrombin time (TT); activated partial thromboplastin time (APTT); fibrinogen (FIB); and major medical comorbidities, such as diabetes, hypertension, pulmonary and heart disease (arrhythmia and coronary heart disease), were recorded and analyzed according to previous studies. [19][20][21][22][23][24][25][26][27][28][29] Anticoagulant therapy included a history of taking aspirin or low-molecular-weight heparin. Preoperative/postoperative systolic/diastolic pressures were recorded.…”

“…Although cervical spinal surgeries, especially ACF, are thought to be safe and less invasive, SIBL may occasionally occur. [25][26][27][28][29][30] For posterior cervical laminoplasty, independent risk factors for SIBL in previous studies included the Pavlov ratio, OPLL, number of complete hinge fractures, 25 an occupying ratio of 60% or greater, 26 the spatial relationship of the K-line and the osteophyte 27 and thick posterior cervical soft tissue. 28 For ACDF, male sex, fusion with a titanium plate and cage, longer operation time and high INR were independent risk factors for hidden blood loss.…”

“…[25][26][27][28][29][30] For cervical laminoplasty, independent risk factors for SIBL have been well discussed in previous studies. [25][26][27][28] For ACDF, independent risk factors for hidden blood loss included male sex, longer operation time, fusion with a titanium plate and cage and high international normalized ratio (INR). 29 However, to our knowledge, few reports have discussed the incidence and risk factors for SIBL during ACF.…”

The efficacy and safety of thrombin-based flowable hemostatic agents in spine surgery: a protocol for systematic review and meta- analysis

“…Intraspinal venous plexus bleeding is also the leading cause of bleeding during spinal decompression, especially in patients with severe spinal stenosis. Intraspinal venous plexus is more likely to bleeding, due to the blood vessel walls are thinner and the increase of tension in the vessel after a longterm extrusion [5][6][7] . Moreover, vascular stiffening, abnormalities in coagulation, and other factors in elderly patients will increase the di culty of hemostasis, which caused by intraspinal venous plexus.…”