Effect of Anatomic Variability and Level of Approach on Perioperative Vascular Complications With Anterior Lumbar Interbody Fusion.
METHODS
Retrospective review of prospectively collected data.


OBJECTIVE
The study aim was to determine the prevalence of vascular complications associated with anterior lumbar interbody fusion (ALIF) as a function of anatomic variation and the number of levels fused.


BACKGROUND
ALIF often requires mobilization of the great vessels, particularly when exposing levels above L5-S1. The exposure can be more challenging in the setting of spondylolisthesis or transitional anatomy.


METHODS
This retrospective review of prospectively collected data from our spine database identified 204 patients who had undergone single level (n = 142) or multilevel (n = 62) ALIF from 2008 to 2013 with minimum 6-month follow-up. Average age was 58 years; 57% were female. Preoperative radiographic assessment for spondylolisthesis and transitional anatomy was performed. Body mass index, estimated blood loss, and levels of ALIF were recorded. Intraoperative vascular injury, postoperative deep venous thrombosis, and pulmonary embolism events were noted.


RESULTS
Eleven patients experienced postoperative thromboembolic events and were more likely to have had intraoperative vascular injury compared with patients who did not develop a vascular complication (36% and 5%, respectively; P = 0.004). Estimated blood loss was significantly higher in patients with spondylolisthesis when compared to patients without spondylolisthesis (520 cc vs. 103 cc, respectively; P = 0.017) or transitional anatomy (347 cc vs. 262 cc, respectively; P = 0.022). Patients undergoing multilevel ALIF had significantly higher blood loss than patients undergoing a single level procedure (684 cc vs. 107 cc; P < 0.001). Patient characteristics, blood loss, anatomic variation, and level of approach were not associated with the development of postoperative thromboembolic complications.


CONCLUSIONS
Performing ALIF in the setting of spondylolisthesis or transitional anatomy resulted in higher blood loss. Patients undergoing multilevel rather than single level ALIF experienced greater blood loss. Because patients with intraoperative vascular injury had increased likelihood of postoperative thromboembolic event, thrombosis prophylaxis should be considered in these patients.


METHODS
4.
*Division of Orthopaedics, Scripps Clinic, 10666 N. Torrey Pines Rd, La Jolla, CA, 92037†Shiley Center for Orthopedic Research and Education/Education at Scripps Clinic Scripps Health, 11025 N. Torrey Pines Rd, Suite 200, La Jolla, CA, 92037‡San Diego Center for Spinal Disorders, 10666 N 4130 La Jolla Village Dr #300, La Jolla, CA, 92037.
Ardalan Alen
AA
Nourian
Christine M
CM
Cunningham
Ali
A
Bagheri
James D
JD
Bruffey
Robert K
RK
Eastlack
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016063:Blood Loss, Surgical; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011655:Pulmonary Embolism / Q000175:diagnosis / Q000453:epidemiology*; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D013123:Spinal Fusion / Q000009:adverse effects*; D013168:Spondylolisthesis / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D057772:Vascular System Injuries / Q000175:diagnosis / Q000453:epidemiology*; D020246:Venous Thrombosis / Q000175:diagnosis / Q000453:epidemiology*; D055815:Young Adult