Risk factor analysis and decision making of surgical strategy for V3 segment anomaly: significance of preoperative CT angiography for posterior C1 instrumentation

• Published in: The spine journal 2016-09, Vol.16 (9), p.1055-1061
• Main Authors: Hong, Jae Taek, M.D., Ph.D, Kim, Il Sup, M.D, Kim, Jun Young, M.D, Lee, Ho Jin, M.D, Kwon, Jae Yeol, M.D, Kim, Moon Seok, M.D, Sung, Jae Hoon, M.D
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Anatomic variation; Bone Screws - adverse effects; Child; Clinical Decision-Making; Computed Tomography Angiography; Female; Humans; Male; Middle Aged; Neurosurgical Procedures - adverse effects; Neurosurgical Procedures - methods; Orthopedics; Postoperative Complications - epidemiology; Postoperative Complications - prevention & control; Retrospective Studies; Risk factor; Screw fixation; Spinal Diseases - complications; Spinal Diseases - diagnostic imaging; Spinal Diseases - surgery; V3 segment; Vertebral artery; Vertebral Artery - diagnostic imaging; Vertebral Artery - pathology
• ISSN: 1529-9430; 1878-1632
• DOI: 10.1016/j.spinee.2016.04.019

Abstract Background Context Awareness of vascular anomalies is crucial to avoid iatrogenic injuries during surgical procedure. Although V3 segment anomaly has been well described, the incidence of V3 segment anomaly has been rather variable in the literature and there are few reports regarding the adequate surgical strategy for each type of V3 segment anomaly Purpose To analyze the incidence of V3 segment anomaly and demonstrate the importance of recognizing vertebral artery anomaly in deciding the surgical strategy for C1 screw placement. Study Design A retrospective cohort study Patient Sample One hundred forty seven patients who underwent C1 posterior instrumentation and preoperative three dimensional computed tomography angiography (3D CTA) included. Outcome Measures Primary outcome was the incidence of V3 segment anomaly using preoperative CTA and secondary outcome was the risk factor analysis of the V3 segment anomaly Methods One hundred forty seven patients underwent C1 posterior instrumentation to treat various kinds of upper cervical disease. The patients were assessed the three dimensional computed tomographic angiography (3D CTA) preoperatively to identify the anomaly of the vertebral artery (VA). Each surgical technique of C1 posterior instrumentation was decided upon the shape and the course of the VA around the atlas. Results; Eleven cases of V3 segment anomaly (7.5%) was found on 3D CTA during the study period. Persistent intersegment artery was found in nine cases and was most common variant of VA anomaly. Early branch of PICA was found in three cases. Most of V3 segment anomaly was found unilaterally but there were two cases with bilateral V3 anomaly. Seven cases (63.6%) were associated with congenital bony abnormality around craniovertebral junction (CVJ) such as occipital assimilation, Klippel-Feil syndrome and os odontoideum. V3 segment anomaly was significantly common in the cases with bony abnormality (29.2% (7/24) vs 3.6% (4/123), p