Postoperative hemorrhage manifests with blood loss from drains or nasogastric tube, and/or clinical signs of hypovolemia (loss of blood volume). Unless the bleeding requires emergency treatment, all patients should be initially monitored (hemoglobin, red blood cell count, hematocrit, blood pressure, pulse, urine output). A CT-scan may be able to demonstrate the bleeding site and the associated abdominal collections. 

Early post-pancreatectomy hemorrhage occurs in the first 24 hours postoperatively. It is caused most likely by technical failure of appropriate hemostasis during the index operation or an underlying perioperative coagulopathy. If feasible, it can be treated by blood transfusions; otherwise, re-exploraton and hemostasis are required. Re-exploration within 24 hours from the index operation does not modify substantially the post-operative course.

Late post-pancreatectomy hemorrhage occurs typically from complications of the operation, with a usual delay of several days or even weeks (eg, after intraabdominal abscesses, erosion of a peripancreatic vessel secondary to pancreatic fistula or intraabdominal drains, ulceration at the site of an anastomosis, or in association with an arterial pseudoaneurysm that has developed). A so-called “sentinel bleeding”, a small amount of blood loss via abdominal drains or nasogastric tube several hours before massive hemorrhage, may be present (30% to 100%). Diagnostic angiography may localize the bleeding site, and embolization can be performed. Otherwise, surgical re-exploration may be needed, especially to treat a massive bleeding or to treat a concomitant complication (e.g. pancreatic fistula). Endoscopy may play a role in intraluminal bleeding.  Late hemorrhage is a serious event associated with mortality rates of 15-20%.

Intraluminal bleeding occurs into the bowel lumen. In pancreaticoduodenectomy and middle segment pancreatectomy bleeding may originate suture lines of the pancreato-enteric anastomosis because of enzymatic digestion of the blood vessel wall on the pancreatic stump surface by pancreatic exocrine enzymes secondary to a pancreatic leak. Other sites of intraluminal bleeding include the gastro-enteric or the duodeno-enteric anastomosis. Such bleedings usually depend on gastric/duodenal ulcer or diffuse gastritis. Intraluminal bleeding presents with dark blood in the nasogastric tube (if present), or with hematemesis and/or melena (black stools), and/or signs of hypovolemic shock. The treatment of bleeding from the enteric anastomosis is endoscopic, while bleeding from the pancreatic anastomosis may require surgical re-exploration.

Extraluminal bleeding occurs in the abdomimal cavity, and may originate from arterial or venous vessels in the areas of resection (especially retroportal lamina), or eroded and ruptured pseudoaneurysms, that are secondary to intra-abdominal infection with involvement of peripancreatic vessels, or vascular injury during resection. Intraluminal bleeding presents withblood loss from intra-abdominal drains and/or signs of hypovolemic shock. The treatment may be either surgical or angiographic. 

The severity of bleeding can be differentiated into 2 categories based on the amount of blood loss or transfusion requirements: mild bleeding involves no clinical impairment, drop of hemoglobin level by <3 g/dl, and transfusion <3 units of packed red blood cells within 24 hours. Severe bleeding involves a large volume blood loss (drop of hemoglobin level by >3 g/dl), clinically significant impairment (eg, tachycardia, hypotension, oliguria, hypovolemic shock), need for blood transfusion >3 units of packed red blood cells within 24 hours, and need for invasive treatment (interventional angiographic embolization, or relaparotomy).