Submission Type
Case Report
Abstract
Introduction: Intestinal nonrotation, a subtype of intestinal malrotation, is a congenital anomaly in which the midgut fails to complete the normal 270-degree counterclockwise rotation around the superior mesenteric vessels. Although often asymptomatic in adults, this anatomic variant can present unique challenges during oncologic colon surgery, where a detailed understanding of intestinal vascular and lymphatic anatomy is essential for safe and oncologically adequate resection.
Clinical Findings: A 78-year-old female presented with a partially obstructing, mismatch repair–proficient cT4b transverse adenocarcinoma with posterior retroperitoneal invasion in the setting of previously unknown intestinal nonrotation anatomy.
Clinical Course: Careful review of cross-sectional imaging identified findings consistent with nonrotation: failure of the duodenum to cross the midline, inverted relationship between the superior mesenteric artery and vein, and abnormal colonic positioning. Following colonic bypass and 6 cycles of folinic acid, fluorouracil, and oxaliplatin combination chemotherapy, the patient underwent an open oncologic subtotal colectomy with ileosigmoid anastomosis and en bloc resection of locally invaded tissues. High ligation of the atypically positioned ileocolic, right colic, and middle colic arteries was carefully performed to achieve an adequate lymphadenectomy while preserving small-intestine blood supply. The final pathology results revealed a 6-cm adenocarcinoma with negative margins and 33 negative lymph nodes.
Conclusions: Intestinal nonrotation is a rare congenital anomaly that presents challenges during oncologic colon surgery due to atypical mesenteric vascular anatomy. This case highlights the importance of preoperative recognition and awareness of this uncommon anatomic variant to preserve bowel perfusion and achieve an oncologically sound resection.
Recommended Citation
Mait, Melanie B.; McKeown, Morgan E.; Keffer, Luke P.; Turner, Christopher; and Mack, Joseph D.
(2026)
"Oncologic Colon Surgery with Intestinal Nonrotation Anatomy: An Illustrated Case Report,"
Journal of Maine Medical Center: Vol. 8
:
Iss.
2
, Article 11.
Available at:
https://doi.org/10.46804/2641-2225.1269
