Emergency surgery for malignant large bowel obstruction has high morbidity and mortality
[1]. Alternatively, SEMSs may palliate an obstruction or act as a “bridge to surgery”
[2]. Stent placement has a complication rate of around 25 % [3]; complications include perforation, migration, and blockage [4]
[5].
An 84-year-old woman was referred with constipation. A computed tomography (CT) scan
demonstrated a sigmoid tumor with metastases ([Fig. 1]). Flexible sigmoidoscopy and biopsies demonstrated a rectosigmoid adenocarcinoma.
She subsequently developed acute bowel obstruction. A gastrograffin enema demonstrated
that the tumor was amenable for stenting ([Fig. 2]). Under colonoscopic and fluoroscopic guidance, a self-expandable metal stent (SEMS)
(24 × 120 mm Niti-S colonic uncovered stent; Taewoong Medical, Korea) was positioned
across the tumor ([Fig. 3]).
Fig. 1 Contrast-enhanced computed tomography (CT) scan of the abdomen and pelvis, demonstrating
extensive mucosal thickening of the sigmoid colon (arrow) causing narrowing of the
bowel lumen.
Fig. 2 Lateral view of water-soluble contrast enema. There is a stricturing lesion in the
sigmoid colon (arrow).
Fig. 3 Fluoroscopic screening of colonic stent insertion with satisfactory stent placement
across the level of obstruction. Free passage of contrast through the stent is opacifying
the presumed more-proximal sigmoid colon.
Following the stenting procedure, the patient’s symptoms were unresolved. A gastrograffin
enema demonstrated contrast failing to pass proximal to the stent ([Fig. 4] and [Fig. 5]). Flexible sigmoidoscopy was then performed; the stent appeared correctly situated
but blocked with feces, which was endoscopically irrigated and cleared. However, the
patient’s condition worsened and she proceeded to laparotomy 5 days after stent placement.
Fig. 4 Plain abdominal X-ray showing significantly dilatated large bowel loops (black arrow)
proximal to the sigmoid colon stent (white arrow), which appears to remain in a satisfactory
position, fully opened out.
Fig. 5 Lateral view of water-soluble contrast enema with stent in situ. There is no passage
of contrast through the stent (arrow), and there is dilatation of more-proximal large
bowel loops, in keeping with complete obstruction.
At laparotomy, there was gross colonic distension with cecal necrosis and perforation.
The tumor was fistulating from the rectosigmoid into proximal sigmoid, with the stent
lying into the closed loop of distal sigmoid colon. A palliative subtotal colectomy
and end-ileostomy was performed. Remarkably, the patient’s post-operative course was
without complication, and she died at home 4 months later.
The staging gastrograffin enema failed to delineate the fistula. Contrast must be
seen to enter the proximal bowel before proceeding. Here the guide wire was passed
only into the distal sigmoid, thereby into the blind loop. Fluoroscopic visualisation
of the guide wire passing to the splenic flexure would ensure the stent was deployed
into the true lumen. Colonic fistulae should be an indication for stenting, and a
correctly deployed stent within the true lumen of the proximal colon will lead to
successful management.
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