Surgical Pancreas / fetch dvm360 conference March 2023 / Dr. Shadi Ireifej / VetTriage скачать в хорошем качестве

Surgical Pancreas / fetch dvm360 conference March 2023 / Dr. Shadi Ireifej / VetTriage

PANCREATIC INSULINOMA Insulin-secreting beta cell tumors are also called insulinomas, adenomas, or adenocarcinomas. They arise from the pancreatic islet cells. The canine insulinoma is a malignant, slow growing, well-differentiated, rarely depicting mitotic figures tumor. Although rare to uncommon in their incidence, insulinomas are the most common pancreatic endocrine tumor reported in dogs. They are rare in cats.13, 24 They are commonly seen in the ferret. Insulinomas are a functional tumor of pancreatic beta cells that causes a decrease in glucose production and an increase in glucose utilization via excessive production of either insulin or proinsulin. Insulin production and release is independent of the normal negative feedback effects of hypoglycemia. Insulinoma-affected patients are middle to older aged, medium to large breed dogs. The mean age is 9 years, ranging from 3.5 to 15 years. The mean weight of affected dogs is 27 kg, ranging from 6 to 52 kg, with 73 to 75% of dogs weighing greater than 25 kg and 48% of dogs weighing greater than 35 kg. Representative canine breeds include mixed breeds (22% of cases), Irish setters (10%), German shepherd dogs (10%), boxers (8%), golden retrievers (6%), poodles (6%), and Labrador retrievers (5%). Affected cats are 12 to 15 years of age with Siamese and Persian cats being most commonly represented. There is no gender predilection for both dogs and cats.   The goal of surgery is to diagnose the condition, stage the disease process, and debulk or remove the tumor. Treatment is primarily palliative in all affected patients.24   Post-operative hypoglycemia is seen in 15% to 26% of patients, due to either nonresectable disease or functional metastatic disease, and is treated with intravenous fluids and 2.5 to 5% dextrose for 48 to 72 hours. The goal is to reach a blood glucose value of 75 to 100 mg/dL.13,24 Post-operative hyperglycemia (greater than 180 mg/dL) is seen in 8 to 35% of patients due to residual normal beta cell insulin suppression. If this persists with glucosuria for more than 48 to 72 hours then treatment with insulin is initiated for 3 to 5 days post-operatively.13,24 This transient diabetes mellitus can last anywhere between days to months post-operatively.24   Pancreatitis, characterized by vomiting and abdominal pain, is another complication of surgery, seen in 10 to 43% of patients. Prevention is seen good surgical technique, the administration of intravenous fluids pre-operatively and with feeding a quality. Affected patients are withheld from food and water for 24 to 48 hours post-operatively and kept on a continuous rate infusion of intravenous fluids.24 If seizures due to hypoglycemia are seen, then Karo syrup is applied on the dog’s gums and/or 1 to 5 ml of 25% to 50% dextrose (or 0.5 g/kg) is given intravenously over 10 to 60 minutes (rapid administration risks a rebound hypoglycemia).24,42 Anticonvulsants may also be initiated in cases suffering from intractable seizure activity. 24   Frequent feedings of small meals that contain high protein, fat, and complex carbohydrates is given 3 to 6 times daily.24   Glucocorticoids can be given, especially if a strict diet has no effect. The long term prognosis is poor with recurrence of disease and recurrent disease or hypoglycemia being seen in 100% of affected patients.24 Prognostic factors include method of treatment, stage of disease, age of the affected patient, higher insulin pre-operatively, glucose levels post-operatively, and the presence of a peripheral neuropathy (which may improve post-operatively and with use of steroids). The prognosis may also relate to the mitotic rate present.           Survival with partial pancreatectomy and without metastatic disease is a median of 381 to 785 days, ranging from 20 days to 1758 days, and normoglycemia being maintained for 14 months. This is significantly longer than the survival of 74 days (ranging from 8 days to 508 days) with medical therapy.24 When comparing enucleation to partial pancreatectomy, mean survival is 11 to 11.5 months and 17.9 to 18 months, respectively.13,24   Survival for stage 1 or 2 patients is a median of 8 months to 18 months.13,42 Stage 3 patients survive a median of less than 6 months. Stage 1 patients maintain normoglycemia for a median of 14 months. Stage 2 or 3 patients maintain normoglycemia for a median of one month. Normoglycemia post-operatively results in a median of 680 day survival and hyperglycemia results in a 90 day median survival. The majority of stage I patients (80%) maintain euglycemia for 14 months, while stage II maintain euglycemia for 8 to 9 months, and stage III for 6 months.   The long term recurrence rate of hypoglycemia post-operatively will eventually be 100%.