The following is a summary of “Preoperative CT Indices Predict Nonreach Before IPAA,” published in the November 2023 issue of Gastroenterology by Adams, et al.
The goal of IPAA is to help people who have had total proctocolectomy regain their continence. But some people don’t have enough small-bowel mesenteric length for repair. There were no native anatomy risk assessment tools available before surgery. The Researchers reported readings of anatomical features using CT scans to identify non-reach before IPAA. The study looked at people with IBD who were going to have a 2- or 3-stage IPAA and an abdominal CT scan before the surgery. The CT scan could use either an enterography procedure or IV contrast that was strong enough to show the mesenteric vessels.
They looked at three CT mesenteric indices: total length (the distance the pouch needs to travel to reach the anal canal), mesenteric length (the natural length of the small intestine mesentery), and mobilization length (the difference between total length and mesenteric length). The main result was IPAA nonreach. The second results were the links between clinical factors and CT mesenteric indices. Six out of 59 cases (10%) had nonreach. There was a 5.8-cm difference in mobilization length and a 3.5-cm difference in mesenteric length between the reach and nonreach groups (P = 0.01). A mobilization length of 17 cm or more showed 100% sensitivity and 69% specificity for nonreach (OR 1.46, area under the curve 0.84, P = 0.004).
Also, a mesenteric length of less than 14.6 cm showed 100% sensitivity and 49% specificity for IPAA nonreach (area under the curve = 0.75, P = 0.03). Because the study looked back, there was no way to make a normal scan procedure. There will need to be external confirmation because the sample size is so small. Measurements of length taken with a CT scan, especially mesenteric and mobilization length, show that there will be no reach before IPAA. This method is easy to get, doesn’t hurt the patient, and might be useful for coaching patients before surgery and planning it.
