[Contribution] Why some gastric cancer patients face higher bleeding risk...

Song Kyo-young, Professor of the Department of Gastroenterology at the Catholic University of Korea Seoul St. Mary's Hospital

Professor Song Kyo-young

Gastric cancer surgery is generally considered a safe procedure. However, in rare cases, a serious complication known as postoperative bleeding can occur.

Although the incidence of bleeding after gastric cancer surgery is relatively low — reported in about 1 percent to 4 percent of all cases — it can become life-threatening and therefore requires close attention. The nature of the bleeding differs depending on both its location and timing.

When classified by location, intraluminal bleeding refers to bleeding within the gastrointestinal tract, typically at the anastomosis site where the bowel is reconnected. Extraluminal bleeding, on the other hand, occurs within the abdominal cavity. In terms of timing, bleeding may be categorized as early bleeding, which occurs immediately after surgery, or delayed bleeding, which develops around one week after surgery or later.

Early bleeding usually results from incomplete hemostasis during surgery. Even if no obvious bleeding is observed before the patient leaves the operating room, postoperative increases in blood pressure may trigger bleeding afterward. Patients with underlying conditions such as liver disease or coagulation disorders are particularly susceptible.

Delayed bleeding, however, has a very different mechanism. When complications such as inflammation, anastomotic leakage, pancreatic fluid leakage or intra-abdominal abscesses develop around the surgical site, nearby blood vessels can weaken and rupture, causing sudden massive bleeding. In other words, delayed bleeding is often a consequence of other postoperative complications.

Gastric cancer surgery is underway. (Courtesy of Seoul St. Mary's Hospital)

Numerous studies have identified factors associated with a higher risk of postoperative bleeding. The risk increases in patients with advanced-stage cancer, extensive gastric resection or lymph node dissection, or surgeries involving combined organ resection, all of which increase surgical complexity.

Patient-related factors are also important. Elderly patients and those with multiple underlying diseases face a greater risk of postoperative bleeding. In addition, complications such as anastomotic leakage, pancreatic fistula and intra-abdominal infection significantly increase the likelihood of bleeding.

Bleeding inside the gastrointestinal tract may manifest as blood emerging through the mouth or anus. Vomiting blood is referred to as hematemesis, while black stools or bloody stools may occur when bleeding exits through the anus. Patients may experience dizziness, palpitations, pallor and cold sweats. Rapid heart rate, low blood pressure and decreased hemoglobin levels are also common findings.

When postoperative bleeding is suspected but symptoms are unclear, physicians may insert a nasogastric tube to check for evidence of bleeding. In cases of intra-abdominal bleeding, diagnosis is often made when bright red blood increases through the surgical drain. Associated symptoms may include abdominal distension, severe abdominal pain, hypotension, rapid pulse and reduced urine output.

To identify postoperative bleeding complications, medical teams closely monitor symptoms, drainage output, vital signs such as blood pressure and pulse rate, and urine volume. Blood tests are performed simultaneously to assess hemoglobin levels and coagulation status. Once bleeding is confirmed, aggressive fluid resuscitation is initiated, and blood transfusion is prepared immediately.

Diagnostic approaches vary depending on the bleeding site. If intraluminal bleeding is suspected, endoscopy is the most important tool because it allows physicians to both identify and treat the bleeding source simultaneously. If intra-abdominal bleeding is suspected, contrast-enhanced CT scans are used to identify the bleeding location and determine whether active bleeding is ongoing. In some cases, angiography is performed to locate and treat the bleeding vessel directly.

Two factors are central in determining treatment strategy: the location of the bleeding and whether the patient’s vital signs are stable. If bleeding is limited and the patient remains stable, conservative treatment such as intravenous fluids, transfusion and medication may be sufficient. In particular, early anastomotic bleeding often resolves spontaneously as blood clots form.

However, if bleeding persists or vital signs become unstable, more invasive treatments — including endoscopic intervention, embolization or reoperation — may be necessary.

Most intraluminal bleeding occurs at the anastomosis site and can often be treated endoscopically. Endoscopic clips, hemostatic devices and injection therapies can be used to achieve direct hemostasis.

Management differs for intra-abdominal bleeding. If the patient’s blood pressure drops to dangerous levels, emergency surgery must be considered immediately. In some cases, angiographic embolization — which blocks the bleeding vessel — may also be an option. However, embolization is not always feasible. It may be limited when the bleeding source is unclear or when blocking blood flow carries a high risk of bowel necrosis.

The indications for reoperation are relatively clear. Immediate surgery is required when blood pressure cannot be maintained despite aggressive fluid replacement and transfusion, meaning the patient remains in shock. Surgery is also necessary when endoscopic treatment or embolization fails to control the bleeding. Furthermore, when intra-abdominal infection, anastomotic leakage or abscess formation accompanies the bleeding, surgery is often needed not only to stop the hemorrhage but also to address the underlying cause.

Prognosis varies greatly depending on the type of bleeding. Early anastomotic bleeding generally has a favorable outcome, with most patients recovering after appropriate treatment. Delayed intra-abdominal bleeding, however, is far more dangerous. Mortality rates rise sharply when infection or leakage is present. Some reports indicate that arterial bleeding carries a mortality rate exceeding 30 percent. Ultimately, the most important factor is how quickly the condition is recognized.

Preventing postoperative bleeding begins with meticulous hemostasis during surgery, safe anastomosis techniques and minimizing pancreatic injury. After surgery, reducing complications such as leakage and infection is equally important in preventing bleeding. High-risk patients require especially careful monitoring. Particular caution is warranted in patients with advanced cancer, extensive surgery or combined organ resection. Patients taking anticoagulants or antiplatelet agents should also have their medications carefully adjusted according to individual circumstances.

Bleeding after gastric cancer surgery is a potentially life-threatening complication, but it can be effectively treated when detected early. Patients should immediately notify medical staff if they experience hematemesis, black stools, bloody stools or bright red blood draining from surgical tubes. In postoperative bleeding, the key is rapid recognition and prompt intervention.

Song Kyo-young