This study found that while the majority of HPVG patients (18/30, 60%) did not have bowel ischemia, it was the most common specific underlying disease in adults with HPVG (12/30, 40%), which is consistent with earlier reports [3, 17]. In view of the outcomes described, bowel ischemia in HPVG patients should still be regarded as an ominous radiologic sign, in contrast to the favorable outcomes in HPVG patients without bowel ischemia. Indeed, the mortality of HPVG patients with bowel ischemia who had undergone surgery was 50% (4/8). In particular, three out of four patients who underwent bowel resection and primary anastomosis suffered from anastomotic leak, which directly lead to mortality, suggesting that the use of a prophylactic stoma should be considered in such patients. Modern surgical techniques, such as fluorescent angiography for the verification of intraoperative vascular perfusion, might have a positive effect on the prognosis of those who are predisposed to postoperative anastomotic leak .
We also found that the peritoneal irritation sign, several laboratory findings on admission (BE, lactate, NLR, and CRP), and IP on CT represented potential prognostic factors for bowel ischemia in the full cohort with HPVG, although this finding was based on univariable analyses, because of the relatively small sample size. In particular, dichotomized BE and lactate remained significant predictors of bowel ischemia, even in HPVG patients without the peritoneal irritation sign (n = 23). Patients who present with obscure symptoms, because of their highly advanced age or impaired consciousness, for example, might benefit from measurement of these variables at diagnosis. These variables, other than NLR, have been already reported to be candidate predictors of bowel ischemia in patients with HPVG [16, 22–27]. However, no previous reports have described an association between high NLR and bowel ischemia in HPVG patients, although some researchers have suggested that NLR might be useful for the identification of, and assessment of the severity of, acute mesenteric ischemia . Therefore, further research regarding the predictive value of NLR in larger groups of patients should be conducted, because some institutions do not routinely measure other variables, such as CRP .
In the present cohort, three of eleven patients (27%) undergoing emergency surgery had an exploratory laparotomy alone, due to intraoperative recognition of the absence of bowel ischemia, and were subsequently managed conservatively. Such over-diagnosis might be justified in the context of the highly unfavorable outcomes in HPVG patients who do have bowel ischemia. However, further refinement of the methods used for the identification of underlying disease in HPVG patients should reduce the need for unnecessary surgery. This might also contribute to more rapid decision-making regarding the necessity for emergency surgery, which could reduce mortality, although in the present study there was a median of only 7.1 hours (range 3.4–34) between arrival and surgery. In addition, the identification, not only of the presence of bowel ischemia in HPVG patients, but also of its severity, would be clinically relevant for the selection of the safest procedure (for example, the creation of a prophylactic stoma or not) during emergency surgery. For instance, previous studies have demonstrated that the type of IP (band-like or bubble-like) is significantly associated with the severity of bowel ischemia [16, 30], but this relationship could not be validated in the present, relatively small cohort.
The present study had a few limitations, including its retrospective nature and the small number of patients with HPVG studied, which meant that multivariable analysis of the potential predictors of bowel ischemia could not be performed. Second, there was a significant proportion of patients (4/30, 13%) who presented with impaired consciousness as their principal complaint, and whose physical findings, including the peritoneal irritation sign, were difficult to establish. Third, eight of the 30 patients (27%) were diagnosed using non-enhanced CT, because of renal functional impairment or drug allergy, but such diagnostic heterogeneity is reflective of general clinical practice and is consistent with previous findings .