Prevention of pulmonary embolism and intra-abdominal anastomotic leakage after biliary-pancreatic bypass surgery

Intra-abdominal anastomotic fistula

It is difficult to identify peritonitis in patients with morbid obesity.

The high mortality rate caused by intra-abdominal anastomotic leakage is due to delayed diagnosis.

The most important determinant of a patient's survival is a high degree of suspicion and early detection.

Anastomotic leakage can occur at the suture or staple site.

Extensive resection and reconstruction of the intestine in BPD and BPD-DS leads to this complication. Fistulas typically occur at: ① proximal gastrointestinal anastomosis or duodenoileal anastomosis; ② gastric pouch sutures; ③ duodenal stump sutures; ④ distal enteroenterostomy.

Because the surgical learning curve and surgical procedures are relatively more complex, the probability of fistula formation during laparoscopic surgery is relatively high.

Generally, the probability of fistula formation in BPD-DS is higher than in simple BPD because the former has a longer sleeve gastrectomy closure line.

Anastomotic leakage and gastric leakage following open bariatric surgery are associated with 55% of deaths.

In any morbidly obese patient who develops acute respiratory failure postoperatively, peritonitis should be highly suspected.

The clinical symptoms and signs are similar to those of massive pulmonary embolism, including severe tachypnea, tachycardia (heart rate >120 beats/min) and sudden hypotension.

In addition, acute respiratory failure syndrome (ARDS) can also be induced by sepsis.

Occasionally, bile or clear bubbly fluid may be seen in the closed abdominal drainage tube.

Using water-soluble contrast agents, such as meglumine diatrizoate, for upper gastrointestinal radiographic examinations is of diagnostic significance.

If the abdominal drainage tube has not been removed, have the patient drink diluted meglumine blue to check if it can drain from the tube.

For duodenal stumps or distal jejunojejunostomies, the use of contrast radiography is often difficult to diagnose because contrast agents cannot easily reach the site.

The only meaningful detection method for duodenal stump fistula is radionuclide hepatobiliary duct scanning (HIDA), which proves that bile leaks into the peritoneal cavity through the bile-pancreatic-intestinal loop.

However, it is not very specific and is usually difficult to identify.

Laboratory test results are usually normal, but occasionally an elevated white blood cell count may occur.

The drainage fluid can also be examined to determine the presence of amylase and bilirubin.

If a patient's condition worsens, even if imaging and laboratory tests are normal, an abdominal fistula must be considered, and immediate exploratory surgery via laparoscopy or open surgery is necessary.

Treatment of intra-abdominal fistulas depends on the size of the fistula, but more importantly, on the patient's clinical condition.

Fistulas with small proximal anastomotic sites, as revealed by contrast imaging, can be cured with conservative treatments such as drainage, antibacterial therapy, and parenteral nutrition.

However, surgical repair or drainage is indicated when a patient has a large and progressive fistula or when the patient's clinical condition deteriorates.

When the patient is still unable to eat, a jejunal feeding tube should be inserted through a jejunostomy to provide enteral nutritional support.

These procedures can be performed via laparoscopy or open surgery.

Duodenal stump fistula is more difficult to diagnose and more dangerous to treat.

Simple suturing of the stump is insufficient to prevent it from splitting open again.

If the fistula is large, a duodenal drainage tube may be required.

Bleeding

Postoperative bleeding can cause tachycardia, hypotension, oliguria and decreased blood cell volume, bloody drainage, hematemesis or melena.

The incidence rate after open and laparoscopic BPD and BPD-DS surgery is as high as 10%.

During BPD-DS surgery, the staples along the sleeve gastrectomy line are prone to bleeding, which is exacerbated by postoperative subcutaneous administration of heparin.

Therefore, when performing gastrectomy, it is recommended to use a linear stapler with a 3.5mm stapling, as a stapling that is too large can easily lead to bleeding.

Bleeding at the anastomosis site can usually be stopped by using hemostatic titanium clips, sutures, or an ultrasonic scalpel.

Some surgeons use tissue-strengthening agents, such as fibrin glue or bovine pericardial bandage.

Bleeding from the anastomotic sutures is usually self-limiting.

Vomiting blood indicates that bleeding from the mucosal sutures has entered the digestive tract.

Upper gastrointestinal endoscopy allows for direct observation and hemostasis, and can also be used for treatment with adrenaline or cauterization.

Although most surgeons are not very accustomed to performing endoscopic examinations on fresh anastomoses, we have successfully performed esophageal, gastric, and duodenal endoscopy (EGD) examinations of the digestive tract as early as several hours postoperatively, as well as hemostasis of suture bleeding, without any adverse sequelae.

Blood transfusions are usually only given to older patients and those with symptoms.

The only gold standard for diagnosing bleeding is through laparoscopic or open abdominal surgery.

Patients with hemodynamic instability or a persistent decrease in blood cell volume must be returned to the operating room for treatment.

Treatment should be based on the cause of the bleeding.