What is an endocrine gland
An endocrine gland is a specialized organs that are found in different parts of the body that secrete hormones.
What is a hormone
Hormones are chemical substances that are delivered directly into the blood from endocrine organs. Hormones can produce profound effects on many parts of the body. For example insulin is a hormone that controls blood sugar levels. Testosterone is a hormone that causes the development of male sexual characteristics.
What are endocrine tumors
Endocrine tumors are abnormal growths in endocrine glands. Since endocrine glands produce hormones, tumors of endocrine glands also produce hormones. These hormones are produced in excessive amounts by endocrine tumors and then released into the blood.
The excessive amounts of hormones in the blood produce markedly abnormal effects on the body. For example in normal individuals insulin is secreted from pancreatic islet cells in just the right amount to keep your blood sugar levels within normal limits. In patients with insulin producing islet cell tumors of the pancreas, excessive insulin is produced in the blood that cause large decreases in blood sugar levels so that patients suffer from severe effects of low blood sugar also called as hypoglycemia. Many of these tumours can be benign(not cancerous) but the effects of excess hormones from the tumour can be serious leading to conditions like hypoglcaemic coma and death.
Are endocrine tumors benign (non-cancerous) or malignant (cancerous)
Endocrine tumors can be benign or grow as cancers. Often this distinction between cancer and not cancer is very difficult even after removal of the tumors on histopathology. In some patients removal of what was thought to be a benign growth may come back as a cancerous recurrence. All patients with endocrine tumors of the abdomen should be followed carefully to detect early recurrence of the cancer.
What are abdominal endocrine tumors
There are many endocrine glands that found in the abdomen. The three most important are:
- Adrenal gland
- Islet cells in the pancreas
- Carcinoid tumours
Tumors can arise from both these two endocrine glands. Up to half of all tumors produce excess amounts of hormones that produce symptoms in the affected patient.
What are adrenal tumors
The adrenal gland is really two organs in one. The outer part of the adrenal is called the cortex and the inner part of the adrenal medulla. The two parts of the adrenal perform different functions and have different embryological origins.
Tumors of the adrenal glands arise from the cortex or the medulla part of the adrenal gland. Adrenal tumors commonly present because of excess secretion of hormones by the tumor. The tumors that commonly occur in the adrenal gland are
- Tumors of the adrenal cortex that produce excess secretion of steroid hormones: a condition called Cushing’s disease
- Tumors of the adrenal cortex that produce excess secretion of aldosterone: a condition called Conn’s syndrome
- Tumors of the adrenal medulla produce excessive amounts of catecholamines: a condition called pheochromocytoma
Adrenal tumors can be benign (non-cancerous) or malignant (cancer). Often this separation is difficult to make and long term close follow up is necessary after removal to detect recurrences early in patients who have adrenal cancer.
What is the treatment for adrenal tumors
Adrenal tumors should be removed by surgery. Some of the procedures offered for adrenal tumors are:
- Laparoscopic adrenalectomy:This is the treatment of choice for tumors less than 5cm.
- Open adrenalectomy: This is recommended only in patients where there is suspicion of cancer
- Laparoscopic removal of both adrenal glands: Recommended for patients with disease in both adrenal glands causing Cushing’s disease or pheochromocytoma.
What are islet cell tumors of the pancreas
Islet cell tumors of the pancreas are rare tumors. These tumors are often also called pancreatic neuroendocrine tumors.
Islet cell tumors of the pancreas are different from adenocarcinoma of the pancreas. These tumors tend to be slow growing tumors that are treatable even after they have metastasized to other organs like liver or lymphnodes. Islet cell tumors can produce dramatic symptoms since up to half of these tumors may secrete hormones that produce side effects due to excessive secretion of the hormones.
What are the different types of islet cell tumors
The following types of neuroendocrine tumors are recognized:
- Non-functioning islet cell tumors. Patients with non-functioning tumors do not have any symptoms from excess secretion of pancreatic hormones since the tumor does not secrete any hormones into the blood.
- Functional islet cell tumors. These tumors produce dramatic symptoms because of excess secretion of various different hormones from the tumor in the pancreas.
The following types of functional islet cell tumors are recognized
- Insulinoma: a tumor that produces excessive amounts of insulin.
- Gastrinoma: a tumor that produces excessive amounts of gastrin
- Glucagonoma: an extremely rare tumor that produces excessive amounts of Glucagon.
- VIPoma: an extremely rare neuroendocrine tumor the produces excessive amounts of VIP(Vasoactive intestinal polypeptide).
- Somatostatinoma: an extremely rare tumor that produces excessive amounts of somatostatin.
Treatment for non-functioning islet cell tumors
Surgical removal of non-functioning islet cell tumors is often curative. These tumors typically tend to be large and therefore enucleation of the tumor is usually not possible.
Our approach is to remove these tumors preferentially laparoscopically. An open procedure is usually offered to the patient if there is metastases, for large tumors, if there is invasion of the major blood vessels around the pancreas by the tumor, and by patient preference. For all other patients, the laparoscopic procedure is offered as the treatment of choice.
We offer the following laparoscopic procedures for removal of non-functioning islet cell tumors of the pancreas:
- Enucleation
- Distal Pancreatectomy
- Spleen Preserving Distal Pancreatectomy
- Central Pancreatectomy
- Whipple Operation
Functioning islet cell tumors
Functional islet cell tumors often present in a dramatic fashion due to secretion of excessive amounts of hormones such as insulin, gastrin, or glucagon. These tumors tend to present at a very early stage when the tumor is tiny and is often not readily detectable.
Localization of these tumors in the pancreas is an important consideration since the tumors may be very small, only a few millimeters in size, when the patient presents with major symptoms.
Treatment of functioning islet cell tumors
The different types of functioning islet cell tumors require special consideration for surgery. Surgery is tailored to the type of the tumor.
- Insulinoma
- Gastrinoma
Other functioning neuroendocrine tumors
Whipple operation
The Whipple operation was first described in the 1930’s by Allan Whipple. In the 1960’s and 1970’s the mortality rate for the Whipple operation was very high. Up to 25% of patients died from the surgery. This experience of the 1970’s is still remembered by some physicians who are reluctant to recommend the Whipple operation.
Today the Whipple operation has become an extremely safe operation. At tertiary care centers where a large numbers of these procedures are performed by a selected few surgeons, the mortality rate from the operation is less than 4%. Studies have shown that for good outcomes from the Whipple surgery, the experience of the center and the surgeon is important. Personally over the last 4 years I have done whipple operation with a nil 30 day mortality.
What is a Whipple operation
In the Whipple operation the head of the pancreas, a portion of the bile duct, the gallbladder and the duodenum is removed as appropriate with surrounding lymphnodes. Occasionally a portion of the stomach may also be removed. After removal of these structures the remaining pancreas, bile duct and the intestine is sutured back into the intestine to direct the gastrointestinal secretions back into the gut.
When is a Whipple operation required
A Whipple operation is performed for
- cancer of the head of the pancreas
- cancer of the duodenum
- cholangiocarcinoma (cancer of the the bottom end of the bile duct)
- cancer of the ampulla of vater – an area where the bile and pancreatic duct enter into the duodenum.
- whipple operation may also sometimes be performed for patients with benign (non-cancerous) disorders such as chronic pancreatitis and benign tumors of the head of the pancreas.
What is the results of the Whipple surgery
Over the last 15 years major pancreatic centers developed excellent results for the Whipple surgery. In almost all the major centers the death rate from this surgery is now less than 5%. Personally over the last 4 years I have done whipple operation with a nil 30 day mortality.
Will the Whipple operation improve my survival
The overall survival after the whipple operation for pancreatic adenocarcinoma is about 20% at five years after surgery. Patients without spread of cancer into their lymph nodes may have up to a 40% survival. The actuarial survival is less than 5% at five years for patients with pancreatic adenocarcinoma who are treated with chemotherapy alone.
The operation is usually curative in patients with benign or low grade cancers of the pancreas.
Will I require any further treatment for my cancer after the Whipple operation
We recommend that all patients with pancreatic cancer should have chemotherapy and radiation therapy after the operation. Recent studies from Johns HopkinsUniversity have shown that the survival rate can be increased by as much as 10% by adding chemotherapy and radiation therapy to the surgery for patients with pancreatic adenocarcinoma. This will be discussed with the patient after surgery based on spread of tumour to the lymph nodes, surrounding tissues and margin of clearance along with vascular and perineural invasion.
We do not recommend any further treatment for patients who have benign tumors of the pancreas and in patients with neuroendocrine tumors of the pancreas.
Will I become diabetic after a Whipple operation
During the Whipple operation part of the pancreas, i.e., the head of the pancreas, is removed. Pancreatic tissue produces insulin that is required for blood sugar control. The islets of Langerhans, i.e., insulin producing cells are concentrated in the tail of pancreas. However when pancreatic tissue is removed the body’s insulin releasing capacity is reduced and thus the risk of developing diabetes is present.
Our experience has been that patients who are diabetic at the time of surgery or who have an abnormal blood sugar level that is controlled on a diet prior to surgery have a high chance for the severity of the diabetes becoming worse after the surgery. On the other hand patients who have completely normal blood sugar prior to surgery with no history of diabetes and do not have chronic pancreatitis have a low probability of developing diabetes after the Whipple operation.
What can I eat after the surgery
There is no restriction of your diet after the operation. Some patients may not tolerate very sweet foods and may need to avoid this.
Will my life be altered very much after the Whipple operation? Will I be able to do all the things that I can do now
There is acceptable alteration of lifestyle after the Whipple operation. Most patients are able to go back to their normal functional levels.
Researchers at John Hopkins University mailed surveys to Whipple operation survivors who had been operated on at Hopkins between 1981 and 1997. The questionnaire was broken down into sections that looked at physical abilities, psychological issues and social issues; an additional section evaluated functional capabilities and disabilities. Scores were reported as a percentile, with 100 percent being the highest possible score. The same questionnaire was then sent to a group of healthy individuals and a group of patients who had laparoscopic gallbladder removal.
Responses from this study at Johns hopkins were tallied from 188 Whipple survivors, 37 laparoscopic gallbladder surgery patients and 31 healthy individuals. Whipple survivors on average rated their physical quality of life a 79, compared with an 83 among laparoscopic surgery patients and an 86 among healthy people. For psychological issues, Whipple survivors rated their quality of life to be a 79, compared with an 82 for laparoscopic surgery patients and an 83 among healthy people. Looking at social issues, Whipple survivors ranked their quality of life at an 81, compared with an 84 among laparoscopic surgery patients and an 83 among healthy individuals. There were no statistical difference amongst these groups.
What are the complications that are likely to happen immediately after surgery for the Whipple operation
The Whipple operation is a complex operation with a high chance of developing complications In the hands of surgeons who are experienced with this surgical operation the complication rate is usually very low.
The problems and complications that may be seen after this operation include:
Pancreatic fistula:
After the tumor is removed from the pancreas the cut end of the pancreas is sutured back into to the intestine so that pancreatic juices can go back into the intestine. The pancreas is a very soft organ and in some patients this suture line may not heal very well. If this happens then patients develop leakage of pancreatic juice. Usually the surgeon leaves behind a drainage catheter in the abdomen during the surgery. Any leakage of pancreatic juice after the surgery is usually removed from the body by this drainage catheter. In almost all patients who develop leakage of pancreatic juice after the surgery, the leakage heals on its own. It is uncommon for patients to be re-operated for this complication.
Gastroparesis ( paralysis of the stomach):
The first five to six days after the surgery, you will be provided with intravenous fluids until your bowel function returns. After your bowel function have returned you will begin on a diet of clear liquids and your diet will progress to a regular diet as you tolerate it.
In up to 25% of patients, the stomach may remain paralyzed after the surgery and it may take up to 4 to 6 weeks for the stomach to adapt to the changes after the surgery to function normally. During this period you may not a tolerate a diet very well. If you fall in this category then you will be provided with nutrition through a small feeding tube that your surgeon has placed into the intestine at the time of surgery. In almost all patients the stomach function returns to normal after this 4 to 6 week period after the surgery
What are the long-term complications of the Whipple operation
Some of the long-term consequences of the Whipple operation include the following:
Mal-absorption:
The pancreas produces enzymes required for digestion of food. In some patients removal of part of the pancreas during the Whipple operation can lead to a diminished production of these enzymes. Patients complain of bulky diarrhea type of stool that is very oily. Long-term treatment with oral pancreatic enzyme supplementation usually provides relief from this problem.
Alteration in diet:
After the Whipple operation we generally recommend that the patients ingest smaller meals and snack between meals to allow better absorption of the food and to minimize symptoms of feeling of being bloated or getting too full.
Loss of weight:
It is common for patients to lose up to 5 to 10% of their body weight compared to their weight prior to their illness. The weight loss usually stabilizes very rapidly and most patients after a small amount of initial weight loss are able to maintain their weight and do well.