L-lactate in acute mesenteric ischemia: a reliable biomarker for diagnosis and prognosis?

Acute mesenteric ischemia is a life-threatening condition with high mortality, often caused by arterial or venous hypoperfusion of the intestines. Early diagnosis remains challenging due to nonspecific clinical findings and the unreliability of laboratory biomarkers. Serum L-lactate, a marker of tissue hypoperfusion, has been investigated as a potential prognostic and diagnostic indicator in acute mesenteric ischemia. This retrospective study analyzed 75 patients who underwent emergency surgery for acute mesenteric ischemia between 2010 and 2015. Demographic data, comorbidities, preoperative serum L-lactate levels, operative details, intestinal resection length, and survival outcomes were collected and statistically evaluated. ROC analysis was used to assess the diagnostic power of L-lactate in predicting the extent of bowel resection and to define a cut-off value. The overall mortality rate was 62.7%. Mortality was significantly associated with age ≥65 (p=0.011) and the presence of diabetes mellitus (p=0.041). Preoperative serum L-lactate levels were significantly higher in non-survivors than in survivors (median: 4.88 mmol/L vs. 3.00 mmol/L; p=0.011). However, no significant correlation was found between L-lactate levels and bowel resection length (p=0.316). ROC analysis failed to identify a statistically significant cut-off value for L-lactate in predicting resection extent (AUC=0.580; p=0.316). Preoperative serum L-lactate levels are significantly associated with mortality in patients with acute mesenteric ischemia and may serve as a prognostic biomarker. However, they do not reliably predict the extent of intestinal resection. Larger, prospective studies are required to define clinically meaningful diagnostic thresholds for L-lactate in acute mesenteric ischemia.