Management of Pancreatic Fistula in Older People

Introduction

An abnormal passage or a connection between an organ and a blood vessel or any two body parts is called a fistula. It can be caused due to infection or inflammation or due to trauma and can occur in any part of the body, such as between an artery and vein, pancreatic duct and skin surface, the stomach, and the skin surface, the navel, and the gut, etc. In some cases, fistulas can be surgically created as a part of the treatment procedure. Fistulas can be of different types, such as blind (open at one end), complete (internal and external openings), and incomplete fistulas (an external opening that is not connected to any internal organ); they may also be described by their location. Treatment of the fistulas is through surgical intervention along with antibiotics depending on the cause and extent.

What Is a Pancreatic Fistula?

An abnormal connection or passage between the pancreatic ductal epithelium and another epithelial surface is called a pancreatic fistula. It occurs mainly due to damage to the pancreatic duct due to trauma or due to acute or chronic pancreatitis, which leads to the leak of pancreatic fluid into other organs of the body. Damage or a disruption of the pancreatic duct causes the pancreatic fluid to leak, producing an erosion and leading to different pathways depending on the location of the disruption. Around 40 percent of patients with acute pancreatitis may develop an acute collection of fluid, and of this, few patients may experience the development of a pancreatic fistula.

What Are the Types of Pancreatic Fistula?

Pancreatic fistulas can be classified into internal and external types.

• Internal Pancreatic Fistula - An internal pancreatic fistula occurs due to disruption in the pancreatic duct, which results in its communication between the pancreatic duct with the peritoneal or pleural cavities, which leads to the leakage of the pancreatic fluid to other organs or abdominal spaces.

• External Pancreatic Fistula - An external pancreatic fistula is also called a pancreaticocutaneous fistula. It is a communication between the pancreatic duct and the skin surface, which leads to the drainage of the pancreatic fluid. It can also occur following surgical treatment.

Pancreatic fistulas can also be categorized depending on their clinical course as high-impact and low-impact fistulas.

• Low Impact Fistulas - Low-impact fistulas are not associated with any other medical conditions and do not require further intervention. They can be treated in an outpatient setting without hospitalization.

• High Impact Fistulas - Fistulas resulting in abscesses associated with bleeding or delayed gastric emptying are considered high-impact fistulas. These require radiology-guided intervention and drainage, administration of intravenous fluids for nutrition, repetition of surgery, and prolonged hospitalization.

What Are the Causes of Pancreatic Fistula?

Pancreatic fistulas can occur due to iatrogenic or non-iatrogenic causes; however, most of the external pancreatic fistula cases are due to iatrogenic causes, which may be due to trauma during the surgical treatment, a biopsy or resection of pancreatic tissue, or complications due to an endoscopy procedure. Around 5 to 29 percent of pancreatic fistula cases occur as a result of complications during pancreatic resection. It may also occur due to percutaneous drainage or collection of pancreatic fluid in a cavity space and is known as a pancreatic pseudocyst.

Non-iatrogenic causes of pancreatic fistulas include abdominal trauma and acute or chronic pancreatitis. Disruption of the pancreatic duct in the anterior portion communicates with the peritoneal cavity, and the posterior disruption communicates with the pleural space and the mediastinum.

What Are the Signs and Symptoms of Pancreatic Fistula?

The clinical features of pancreatic fistulas vary depending on the size of the disruption of the pancreatic duct, its location, and the pathway. However, some patients may remain asymptomatic. Some of the signs and symptoms include:

• Abdominal pain.

• Nausea and vomiting.

• Fever.

• Lack of appetite.

• Unable to pass stools.

• Weight loss.

• Distended abdomen.

As the fluid collection increases, it may affect other organs, especially the thorax leading to pleural effusion. It causes symptoms such as cough, wheezing, chest pain, and dyspnea. External fistulas can be noticed from the wound on the abdominal skin and can cause dehydration and weight loss due to malnourishment.

How Is Pancreatic Fistula Diagnosed?

Patients usually present with severe abdominal pain and difficulty in breathing; severe pancreatic fistulas can deteriorate the patient’s condition, and hence the patient is stabilized before differentiating the cause or conducting any diagnostic tests or imaging procedures. Pancreatic fistulas leading to large pleural effusion can be diagnosed by reduced breathing sounds and dullness of percussion in the affected chest area. In external fistulas, a wound can be seen in the skin of the abdominal area, which is warm and erythematous, showing signs of skin breakdown. The fluid samples are collected and sent to the lab for analysis; blood samples are also taken to determine the blood count and a complete metabolic panel that includes the estimation of calcium, albumin, bilirubin, and liver enzyme levels. In the case of patients with ascites, the ascitic fluid is also collected and sent to the laboratory for gram stain tests, cell count, culture, etc. Some of the investigations recommended include:

• A chest X-ray can provide immediate information on the condition; however, a computed tomography (CT scan) helps to determine the cause of the abdominal pain and identify the changes in the pancreas and the presence of fluid collections.

• Magnetic resonance cholangiopancreatography (MRCP) or fistulography, or endoscopic retrograde cholangiopancreatography (ERCP) may be advised to clearly visualize and evaluate the cause of pancreatic fistula. ERCP provides a better view and helps to identify the site of disruption of the pancreatic duct, whereas a fistulography helps identify the location along with the surrounding structures.

How Is Pancreatic Fistula Managed in Older People?

Pancreatic fistula management is carried out by a team of doctors, including surgeons, primary care doctors, radiologists, nutritionists, gastroenterologists, and nurses. Mild cases usually respond well to conservative and supportive management; however, severe cases require surgical intervention. Pancreatic fistulas in older patients are managed by supportive and conservative treatment, along with endoscopic therapy, and in some severe cases, by surgical treatments.

• Supportive and conservative management involves control of the fistula progression and proper nutrition prior to definitive intervention. It involves controlling pancreatic exocrine secretion. This is done by postpyloric feeding (supplying food in a liquid form through a tube that is placed in the mouth or the nose of the patient, extending to the stomach or intestine) or temporary parenteral nutrition by intravenous fluids. It can also be further controlled by somatostatin analog drugs such as Octreotide. Correction of fluid and electrolyte imbalance is an important factor as the patients are at an increased risk of metabolic acidosis due to pancreatic fluid loss, which is rich in bicarbonates. The surrounding skin around the external fistula must be protected to prevent further damage.

• Along with conservative management, some patients may require further intervention in the management of pancreatic fistula. Endoscopic therapy is preferred in case of multiple fistulas, during which a pancreatic stent is placed to facilitate the flow of the pancreatic secretions into an internal drainage pathway.

• Surgical management of the pancreatic fistula depends on the anatomy of the pancreatic duct and the location of the fistula. Pancreaticojejunostomy is the treatment of choice in patients with large duct disease. In case the injury or the disruption is at the pancreatic tail, a caudal pancreatectomy is preferred, along with the drainage of the pancreatic fluid. If the pancreatic disruption is along the body of the duct, a distal pancreatectomy is performed. Through surgical treatment, the majority of pancreatic fistula cases (about 92 percent) can be successfully managed.

What Are the Complications of Pancreatic Fistula?

Pancreatic fistulas require immediate care and management to avoid further complications. Some of the complications include;

• Severe acute pancreatitis may result in reduced blood supply and, in the presence of infection, pancreatic necrosis can occur.

• Acute bleeding associated with pancreatic fistula can lead to erosion of a major blood vessel resulting in Intra-abdominal hemorrhage.

• Leaking of the pancreatic fluid leads to its collection, resulting in the formation of a pseudocyst.

• Continuous leaking of the pancreatic fluid into the peritoneum can result in the formation of pancreatic ascites.

• Pancreatic fluid can get accumulated in the layers of the membrane lining the lung and the chest cavity, called pancreatic pleural effusion.

Conclusion

An abnormal passage between the pancreatic ductal epithelium and another epithelial surface occurring due to disruption is called a pancreatic fistula. It is associated with severe abdominal pain, fever, dyspnea, chest pain, loss of appetite, and weight loss. It is usually managed by surgical intervention along with supportive care. Continued wound care to prevent further damage, regular follow-up appointments with the healthcare team, along with a healthy lifestyle can help manage pancreatic fistula.