Thyroidectomy and cholesterol are related...although not strongly so. I would encourage you to talk to your primary doctor
regarding this. In addition, an endocrinologist
can and should be involved if you are considering a thyroid surgery
Removing the thyroid gland itself should not effect your cholesterol. However, removing the thyroid gland will cause hypothyroidism (or low levels of the thyroid hormone). This is an expected consequence. In some people, hypothyroidism can cause an elevation in cholesterol. This is because the thyroid hormone is the hormone of metabolism--so decreasing its level decreases metabolism and clearance of cholesterol. There are even some people who have small changes in the thyroid hormone (subclinical hypothyroidism) and get abnormal cholesterol levels.
That being said, everyone after a thyroidectomy gets placed on thyroid replacement medication. If this medication is given at the right dose (which sometimes takes time to find) then you do not develop hypothyroidism. If that is the case, then you should not have any effect on cholesterol.
Another consideration, high cholesterol (as I'm sure you know) increases your risk for heart disease. Stressful situations such as surgery put strain on your heart. You should see your primary doctor before any surgery to ensure your heart is "optimized" for surgery.