Background: Superior mesenteric artery syndrome is a known
complication associated with the correction of spinal deformity. Recent
investigations of this disorder have focused on patient height and weight. We
are not aware of any published study examining the degree of deformity, type
of curve, or magnitude of correction, and to our knowledge all of the reported
literature on this syndrome lacks control data. The purpose of this study was
to examine the relationship between the correction of spinal deformity and the
development of superior mesenteric artery syndrome in patients with scoliosis.
Our hypothesis was that greater correction of spinal deformity would increase
the risk of the development of superior mesenteric artery syndrome.
Methods: A case-control study was performed over a five-year period.
The primary outcome measure was the development of superior mesenteric artery
syndrome. The predictor variables that were considered included demographic
characteristics; preoperative height, weight, and body mass index; aspects of
the deformity, including curve magnitude, Lenke curve classification, and
correction; and operative factors, including surgical approach, estimated
blood loss, and the presence of operative hypotension.
Results: A review of the records on 364 surgical procedures for
scoliosis identified seventeen cases of superior mesenteric artery syndrome.
Thirty-four subjects who had had surgery for scoliosis but no superior
mesenteric artery syndrome were randomly selected as controls. Eight of the
seventeen subjects with superior mesenteric artery syndrome had undergone a
two-stage procedure (compared with one of the thirty-four controls, p <
0.001), nine of the seventeen had had combined anterior and posterior
procedures (compared with two of the thirty-four controls, p < 0.001), and
seven of the seventeen had had a thoracoplasty (compared with two of the
thirty-four controls, p < 0.001). No significant differences were noted
between the groups with regard to demographic factors. Compared with the
controls, the patients in whom superior mesenteric artery syndrome developed
were shorter (by a mean of 7.1 cm, p = 0.03), weighed less (by a mean of 11.5
kg, p = 0.001), had a lower body mass index (p = 0.003), had a greater minimal
thoracic curve magnitude achieved by bending (a mean of 12° greater
[45° for subjects with superior mesenteric artery syndrome and 33° for
controls], p = 0.015), had a lower percent correction of the thoracic curve on
bending (a mean of 11% lower, p = 0.025), and had more lumbar lateralization
(88%, compared with 61% in the control group, had a Lenke lumbar modifier of B
or C instead of A, p = 0.008). Multivariate logistic regression analysis
identified a staged procedure (odds ratio, 31.0), the lumbar modifier (odds
ratio, 9.06), body mass index (odds ratio, 7.75), and thoracic stiffness (odds
ratio, 6.67) as the most predictive of the development of superior mesenteric
Conclusions: Preoperative identification of the risk factors
described above in conjunction with preoperative nutritional maximization
should be considered in order to limit the prevalence of superior mesenteric
artery syndrome in patients undergoing surgical correction of spinal
Level of Evidence: Therapeutic Level III. See
Instructions to Authors for a complete description of levels of evidence.