case_images: PMC11442532_01
case_images: Flow chart of stent implantation. (A-C), red arrows indicate anastomotic fistula; (D), yellow arrows indicate the stent guidewire; (E, F) denote the release of the stent under colonoscopy. This stent is a nickel-titanium memory alloy self-expanding stent, which is modified from a nickel-titanium memory alloy esophageal stent and is a coated stent. It is 10cm in length with a diameter of 32 to 35mm on the proximal port side and 28 to 30mm on the distal anal side.
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case_images: A leak of approximately 1.5 cm was detected at 10-1 o'clock at the lithotomy position (red arrows in  Figures 1A, B ). The anastomosis site and the intestinal cavity were rinsed repeatedly, and a necrotic tissue was observed (red arrows in  Figures 1B, C ). By using an endoscope, a guidewire was passed to the proximal end of the anastomotic mouth ( Figure 1D , the yellow arrow represents the stent guidewire). Subsequently, a nickel-titanium memory alloy self-expanding stent was placed, with the proximal and distal ends of the stent at approximately 15 and 5 cm from the anus, respectively ( Figures 1E, F ). The anastomotic stent and the transanal intestinal obstruction catheter were placed again according to the previous steps ( Figures 1 ,  2 ).
case_images: Flowchart of ileus catheter insertion. (A, B), the red arrow refers to ileus catheter insertion under the colonoscope; (C, D), the yellow arrow shows the ileus catheter injection of a 15 mL water sac to fix the ileus catheter to avoid slippage; (E), the green arrow shows stent fixation with 3 titanium clips at the distal end to prevent slipping of the stent. (F), is the modified intestinal obstruction catheter, and the material is the intestinal obstruction catheter material. It is a three-chamber capsule catheter. The length is 50cm, and the purple arrow indicates the flushing tube (internal diameter of 3mm), which is continuously flushed; The sky blue arrow indicates the drained stool (model 24Fr, 8 mm in diameter), which can be connected to the outside of the urine bag. The sky blue color arrow is the water injection tube (5 to 25 mL of normal saline can be injected according to the size of the intestinal wall). However, the black color of the tip refers to the position of the water sac, which is the water sac filled with water and the water sac without water, and the white color is the side hole of the tip, which can avoid the obstruction of the lumen by stool and enhance drainage. While there is a white protective cap at the tip, which is removed when used.
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case_images: An endoscopically guided transanal obstruction catheter ( Figure 2F ) of approximately 20 cm was then inserted ( Figures 2A, B , the red arrow indicates the intestinal obstruction catheter), followed by injection of a 15 mL balloon water to fix the catheter ( Figures 2C, D ). Figure 2E , green arrow). Finally, the intestinal obstruction catheter was fixed to the skin of the anal border. The anastomotic stent and the transanal intestinal obstruction catheter were placed again according to the previous steps ( Figures 1 ,  2 ).
case_images: (A, B), the red arrows indicate the stent at the anastomosis site. (C), the yellow arrow indicates air accumulation around the anastomosis site. (C, D), the sky-blue arrows in the middle indicate the abdominal drainage tube. (D, E), the green arrows indicate excessive exudation in the pelvic cavity with mesenterial thickening. (F), the arrows indicate the sagittal position.
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case_images: The pelvic cavity showed more exudation, with the thickening of the peritoneum and mesangium ( Figure 3 ).
case_images: Reexamination of colonoscopy. (A, B), the red arrow refers to the titanium clip under the intestinal stent, the orange arrow indicates the intestinal obstruction catheter, and the yellow arrow shows the anastomotic stent. (C, D), the green arrows show the intestinal mucosa proximal to the scaffold. (E) Yellow is the ileus catheter, draining the stool. (F), the dark blue color represents the water sac of the intestinal obstruction catheter. No significant fecal residue was detected in the intestinal cavity distal to the obstruction water sac.
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case_images: Nine days after the intervention, a colonoscopy re-examination revealed no displacement of the stent or ileus catheter ( Figure 4 ). First, we confirmed that there was no displacement of the stent or the ileus catheter (similar to  Figure 4 ).
case_images: Flowchart of removing the ileus catheter and stent. (A), the red arrow indicates extracting water from the effluent sac and removing the ileus catheter. (B, C), the orange arrows show the titanium clips below the support. (D, E), the green arrows indicate the anastomotic leakage, which was smaller than before, with a smooth mucosa. Panel (F) shows the anastomosis in dark blue.
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case_images: Next, the ileus catheter was removed ( Figure 5A ). All clips were then removed endoscopically ( Figure 5B ). Finally, at the 11 o'clock position of the anastomosis site (lithotomy position), a leakage of approximately 0.5 cm was detected, which was significantly smaller than that observed before; the surrounding mucosa was smooth ( Figures 5D, E ). Twenty-four days after the intervention, a repeat colonoscopy was performed, and the stent and the transanal intestinal obstruction catheter were removed ( Figure 5  in sequence).
case_images: (A, B), the anastomosis site indicated by the red arrows showed intact smooth mucosa with visible granulomas and no leakage. (C), the green arrow indicates the anastomosis.
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case_images: The anastomosis site showed good healing, and the surrounding mucosa was reddish ( Figure 6 ). More than 5 months after the intervention, a review colonoscopy was performed, and the anastomosis site was found to be smooth and complete, as shown in  Figure 6C .
case_images: (A-C), the red arrows indicate the anastomosis. Compared to the results obtained for the examination on May 22, 2023, no fluid or gas accumulation was observed, and the seepage was significantly reduced.
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case_images: A CT scan revealed no anastomotic abnormalities ( Figure 7 ).