Reply to the Letter to the Editor: “CT diagnosis of closed loop bowel obstruction mechanism is not sufficient to indicate emergent surgery”

by Camille Rondenet, Ingrid Millet, Lucie Corno, Wassef Khaled, Isabelle Boulay-Coletta, Patrice Taourel, Marc Zins

CT diagnosis of closed loop bowel obstruction mechanism is not sufficient to indicate emergent surgery

Dear Editor,

We thank our colleagues for their relevant comments addressed on our article [1].

We acknowledge that this article could be a significant shift to the paradigm that all closed-loop small bowel obstructions (CLO) should benefit from emergency surgery. As our study is a retrospective one, surgeons were not asked to manage CLO conservatively as it is questioned. Many CLO are missed in daily practice and that is precisely the rational of our study; i.e., some CLO do not benefit from prompt surgery because they are missed on CT scan, particularly when there is no sign of ischemia nor clinical criteria of severity. In our country, surgeons are used to follow Bologna’s guidelines [2] for surgical decision making. Then, only the patients with suspected ischemia or necrosis at CT, or those with peritonitis or perforation, are send urgently to the OR. A CLO mechanism, if isolated, does not belong to the criteria used to indicate surgery, as some surgeons do not really believe in this mechanism. It probably remains still far (too much?) a radiological issue. Anyhow, we fully agree that CLO with CT and/or clinical signs of ischemia should undergo surgery without delay.

We already published how to differentiate reversible ischemia and transmural necrosis using CT in the specific context of CLO [3], and more generally the impact of un-enhanced CT to reach this goal [4, 5]. Increased un-enhanced bowel-wall attenuation is the only CT finding associated with necrosis in the CLO context.

We agree that, in the end, we would have operated the majority of CLO (about 80%) and that patients should undergo surgery from the onset, especially when the distance between the 2 transitional zones is small (< 8mm) as we said in our article [1]. But when CLO is uncomplicated at onset, no one can predict what will be the course of the ischemic process. Indeed, we could expect a decrease of the intraluminal pressure in the small bowel with respect to the naso-gastric decompression tube leading to less pressure at the transition point and then a possible spontaneous resolution of the incarceration. We guess that this hypothesis could probably be more realistic when the distance between the 2 transition zones is large. In our article, among the 19/43 (44%) patients that were finally operated after initial conservative management, 12 had a complete bowel wall necrosis needing resection and 7 a reversible ischemia without any resection. We assume that we do not have a large enough cohort to assess the difference in mortality and morbidity between surgery of CLO at an uncomplicated stage and surgery of CLO complicated with bowel ischemia, but all the patients that underwent “delayed” surgery in our study did not have any adverse event during follow-up. The long-term impact of such a strategy is still unanswered.

Evidence is still moving, the management of SBO today is more conservative and it is likely that management tomorrow won’t be the same as nowadays. Recently, a very interesting article suggested that surgery should be done for all patients with small bowel obstruction due to an adhesive band, regardless of ischemic status and obstruction mechanism (single transition zone or closed-loop mechanism). Indeed, nonoperative management would be associated with higher recurrence rates and lower disease-free intervals compared with surgery [6]. Yet, it seems quite uncommon to go for surgery when there is a CLO without any CT or clinical signs of severity.