Operations involving the pancreas are always considered major surgery. While complicated, an experienced team can perform pancreatic surgery safely and with great benefit to the patient. A better understanding of the operations and reasons behind them will help relieve much of the anxiety that is normal and expected.
Simply stated, the pancreas is an organ that is located deep in the upper abdomen behind the stomach, and surrounded by many important structures. The pancreas is divided into the head, neck, body and tail. The head is that part on the right closest to the liver, bile ducts and the duodenum. The tail is the part of the pancreas toward the left, nearest the spleen. The pancreas has 2 major functions, termed exocrine (digestive) and endocrine (hormonal).
The exocrine function of the pancreas is to produce digestive enzymes that help breakdown fats and starches (carbohydrates). These enzymes are secreted into a system of ducts, all leading to the main pancreatic duct. The pancreatic duct enters the first part of the small intestine (duodenum) where it joins with the bile duct, draining bile produced by the liver. Since the bile duct actually passes through the head of the pancreas, operations on the pancreas or lower bile duct usually require removal of both the pancreas and bile duct together. In addition, the duodenum or first part of the small intestine, shares a common blood supply with the pancreas, so it must also be removed whenever the head of the pancreas or lower bile duct is affected by disease or tumor. That surgery is known as the Whipple procedure or pancreaticoduodenectomy.
Yellow jaundice occurs when tumors or fluid filled cysts in the pancreatic head block the flow of bile from the liver into the intestine.
The endocrine function of the pancreas is to produce hormones that are secreted into the blood stream to regulate important biochemical functions. One of these hormones is insulin, which regulates blood sugar. Diabetes may result when a diseased pancreas must be entirely removed. It is quite possible to live successfully after removal of the entire pancreas, though patients require the use of insulin injections and oral digestive enzyme supplements to replace those that were produced in the pancreas. Patients who are not diabetic can tolerate the loss of up to 80% of their pancreas without requiring insulin.
Tumors can arise in the hormone producing cells of the pancreas and can be functional (producing excess hormone) or nonfunctional. These tumors, formerly known as islet cell tumors, are now called pancreatic neuroendocrine tumors or PNETs. Pancreatic neuroendocrine tumors are far less common than the typical type of pancreas cancer, adenocarcinoma, which arises in the pancreatic duct and accounts for about 85% of pancreatic malignancies. Endocrine tumors are slower in growth, less aggressive and may be benign (non-cancerous). An increasing number of pancreatic endocrine tumors are being discovered incidentally during abdominal CT or MRI scanning, done for other purposes. Often the risk of malignant behavior (uncontrolled growth or spread to other organs) is unpredictable and will require removal of the tumor, regardless of its size.
OperationsWHIPPLE PROCEDURE OR PANCREATICODUODENECTOMY
The Whipple procedure is perhaps the most complex and misunderstood of all abdominal operations. This complexity relates to the need for removal of the pancreatic head, the entire duodenum, the lower bile duct, the gallbladder, and at times, a portion of the stomach. From a surgical technical standpoint, it is complicated by the presence of several important blood vessels and the possibility of blood vessel involvement by tumor. Those blood vessels are the superior mesenteric, splenic, and portal veins returning blood to the liver, as well as the celiac, hepatic, gastric and superior mesenteric arteries providing blood to the liver, stomach and intestine. These major vessels must be protected during surgery, and may need to be removed and reconstructed if involved by tumor. Suspicion of major blood vessel involvement by tumor may be a reason that the Whipple procedure cannot be safely performed with the expectation of complete tumor removal. In some cases, surgery may be delayed until chemotherapy and radiation are administered to shrink the tumor in order to to allow for more complete removal. This treatment strategy is known as neoadjuvant therapy.
Following removal of the pancreas and adjacent organs, Whipple surgery involves reconstruction by creating new connections (anastomoses) between the remaining portion of the pancreas, the bile duct, the stomach and the small intestine. In most cases, Dr. Jury will perform the "pylorus-preserving" Whipple procedure, saving the entire stomach; as compared to a "standard" Whipple procedure, which removes the lower third of the stomach. Removal of a portion of the stomach is only required when the location of a tumor makes this necessary to achieve complete tumor removal. Some have described the pylorus-preserving Whipple procedure as a "mini- Whipple.”
In general, a Whipple procedure or pancreaticoduodenectomy takes an experienced team from 4 to 8 hours to perform, with the average time around 5 hours in the operating room.
Recently there has been growing interest in the performance of minimally invasive or laparoscopic Whipple procedures. Decisions to pursue less invasive surgical techniques will always be considered but should never compromise safety or the chance to achieve the best possible surgical outcomes.
The safety and success of Whipple surgery has improved significantly during the past 10 years. Research has shown that patients achieve the best outcomes at “high volume” hospitals. High volume hospitals are those hospitals that perform at least 10-16 Whipple procedures per year. The experienced surgical teams at these hospitals have been able to significantly reduce patient risk and complication rates. Approximately 80% of Dr. Jury’s surgical practice is dedicated to pancreas cancer patients. He performs over 60 major pancreas operations each year with his team at Beaumont Hospital in Royal Oak. Details of his experience will be openly discussed with you.
Distal pancreatectomy is required for tumors or cysts involving the middle or left side of the pancreas known as the body or tail. Often these masses are found incidentally during a CT or MRI scan and don’t generally cause jaundice. The distal pancreatectomy is somewhat less complex than the Whipple operation because the bile duct and duodenum are not involved and no reconstruction is required. The spleen, located in the left upper abdomen, receives and returns blood supply to a large artery and vein behind the pancreas. Because of this involvement, the spleen often needs to be removed at this time in order to safely remove the diseased portion of the pancreas and avoid leaving any tumor behind.
People can live normally after removal of the spleen but do have a slightly higher risk of surgical infection. Where removal of the spleen is likely, patients are given 3 vaccinations prior to surgery for increased protection against infection. These vaccines include pneumococcal (pneumonia), meningococcal (bacterial meningitis) and Haemophilus influenza. As in the Whipple procedure, every effort is made to preserve as much of the normal pancreas as possible and maintain function without the need for insulin or digestive enzymes.