Intestinal malrotation in patients with situs anomaly: Implication of the relative positions of the superior mesenteric artery and vein.
OBJECTIVE
To assess the usefulness of the relative position of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in diagnosing intestinal malrotation in situs anomaly.


METHODS
From January 2004 to April 2015, 33 patients with situs anomalies were enrolled in this study who underwent abdominal USG, CT or MRI as well as upper gastrointestinal series (UGIS) or surgery: situs inversus (n=16), left isomerism (n=10), and right isomerism (n=7); age 21.2±23.2years (mean±standard deviation), range 0-72 years. The intestinal malrotation was confirmed with UGIS and/or operation in 16 patients. Relative positions of the SMV to the SMA were classified into four groups by reviewing abdominal USG, CT, or MRI: right sided, left sided, ventral sided, and dorsal sided. The incidence of malrotation was analyzed for each group.


RESULTS
In 16 patients with situs inversus, there was reversed SMA-SMV relationship: left sided (n=11) or ventral sided (n=5). One situs inversus patient with ventral sided SMV had intestinal malrotation (6.25%). 17 patients with situs ambiguus showed various SMA-SMV relationships (ventral sided, n=7; left sided, n=5; right sided, n=4; dorsal sided, n=1). Among them, 15 patients (88.2%) had intestinal malrotation. Two patients with normal rotation had either right sided or dorsal sided SMV.


CONCLUSIONS
Situs ambiguus was commonly associated with intestinal malrotation with a variable SMA-SMV relationship. Reversal of the mesenteric vascular relationship was observed in situs inversus with normal rotation, not excluding the possibility of intestinal malrotation.
Department of Radiology, Seoul National University Hospital, Republic of Korea.
Kyu Sung
KS
Choi
Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea. Electronic address: iater@snu.ac.kr.
Young Hun
YH
Choi
Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea; Institute of Radiation Medicine, Seoul National University Medical Research Center, Republic of Korea.
Jung-Eun
JE
Cheon
Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea; Institute of Radiation Medicine, Seoul National University Medical Research Center, Republic of Korea.
Woo Sun
WS
Kim
Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea; Institute of Radiation Medicine, Seoul National University Medical Research Center, Republic of Korea.
In One
IO
Kim
D000328:Adult; D000368:Aged; D004065:Digestive System Abnormalities / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D045822:Intestinal Volvulus / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D017538:Mesenteric Artery, Superior / Q000002:abnormalities / Q000000981:diagnostic imaging*; D008642:Mesenteric Veins / Q000002:abnormalities / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D015203:Reproducibility of Results; D012399:Rotation; D012857:Situs Inversus / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography
Heterotaxy syndrome; Intestinal malrotation; Intestinal volvulus; Situs ambiguus; Superior mesenteric artery