AIM: Decreasing intraoperative blood loss is one reported advantage of laparoscopic surgery compared with open surgery. However, several reports indicate that blood loss during laparoscopic surgery may be underestimated. No studies have evaluated this possibility in laparoscopic distal pancreatectomy (LDP). Here we evaluated estimated blood loss (e-BL) compared to intraoperative blood loss (i-BL) during distal pancreatectomy (DP). METHODS: This study included 114 patients undergoing DP in our institution during the study period. We examined the relationship between i-BL and e-BL. Based on these results, we further investigated the relationship with LDP. RESULTS: The laparoscopic approach was used in a significantly higher percentage of patients in e-BL >
i-BL group compared to e-BL <
i-BL group (55.9% vs 10.9%, CONCLUSION: During LDP, e-BL was significantly more than i-BL. During ODP, e-BL was significantly less than i-BL, only in patients with pancreatic cancer. These results suggested the possibility of i-BL underestimation during LDP, and overestimation during ODP in cases with pancreatic cancer.