Sunday, November 2, 2014

A Sense of Where You Are

Years ago I read a book about former US Senator and basketball great Bill Bradley which was titled “A Sense of Where You Are.”
The title derived from a basketball move he could perform which had him drive along the baseline to blindly shoot a reverse layup. He described how  he had developed a sort of sixth sense which allowed him to make this shot, even though he couldn’t see the basket. He had played so much basketball and knew the court so well that he had developed “a sense of where you are.”

This saying popped into my head the other day as I was doing a parathyroidectomy. Now don’t get the idea that I perform surgery blindly. But, parathyroid surgery sometimes requires this sixth sense to track down these pesky little glands. For those of you unfamiliar with the anatomy of the human neck, the parathyroids are four separate glands which hide behind the thyroid gland. A normal parathyroid is about 4-5 millimeters in diameter. Each gland is described relative to its position to the thyroid gland, which is a butterfly shaped organ sitting in the middle of the neck. Thus, there are right and left, upper and lower parathyroid glands, depending on their position behind or adjacent to the thyroid gland. Sometimes, (often) these parathyroids like to hide. They may be lower in the neck closer to the carotid artery or even lower, in the mediastinum (behind the breast bone). It’s sort of like they know someone is searching for them and they don’t want to be found, so, decide to take shelter away from their usual residence.

I’ve done a lot of parathyroid surgeries over the years. Most of the time preoperative testing provides some guidance as to where the abnormal gland is residing. But, these preop scans usually only tell me right or left, upper of lower. I still have to find the offending little beast. This is where it is helpful to have a good sense of where one is.

So, I start by getting the thyroid out of the way which requires dividing a few veins which are collectively called the middle thyroid vein. Then it’s time to look, first for “the nerve”, but also for bulges rising from beneath fat which don’t look like they belong or send a signal which says, “there’s something hiding under here.” The vast majority of the time it is this “something looks out of place” sense that leads me straight to the offending parathyroid gland. After that, it is relatively simple to remove the gland and have a friendly neighborhood Pathologist confirm it is abnormal.

Unfortunately, it’s not always easy.

Vince was in his sixties when he came to me with long standing hypercalcemia and very elevated parathyroid hormone levels, lab tests which led to the diagnosis of primary hyperparathyroidism. Surgery was recommended. His pre operative imaging studies were all normal. Despite this, he still needed surgery, only with him I had nothing to tell me where to look. So I started, first in the left lower position, which is the easiest area to explore. I was heartened as I saw a nodule that appeared to be separate from the thyroid gland. However, as my dissection continued it became clear that this nodule was part of the thyroid itself. Onward went the dissection. In the left upper thyroid I found a tiny, normal appearing parathyroid, about 2 mm in diameter. I looked at the right side and saw a tiny gland behind the lower pole of the thyroid. I didn’t find anything that looked like parathyroid on the upper end. I did identify the recurrent laryngeal nerves and both carotid arteries on both sides. I went back to searching. Perhaps behind the mound of fat next to the right carotid. There was something there. As I removed it my heart sank. It looked more like a lymph node. I sent it off anyway and was not surprised when the Pathologist confirmed that it was a lymph node and not parathyroid.

Where are you, you irritating, mischievous sprite?

Well, maybe down in the mediastinum, which is behind the sternum. So I start pulling tissue, mostly fat, out of the upper chest. Nothing, nothing and more nothing. I had been searching for more than two hours without success.

Maybe it’s time to give up, do more tests, perhaps?

I looked a bit more, farther down in the chest, more towards the middle. I found something. It looked like a parathyroid, kidney bean size, shape and color. Out it came and off it went to the lab.

“Hyperplastic parathyroid.”

Thank you, Pathologist.

Vince’s parathyroid hormone was checked before we woke him up. It fell from a preop level of 2200 down to 500 and then to 40 prior to discharge. His calcium levels dropped to normal. He was cured.

This “sense of where you are” is important in surgeries beside parathyroidectomy. Every operation requires knowledge of anatomy, with all its variants. Plus, normal anatomy is often distorted by cancer or inflammation or trauma.

Operations require dissection and cutting and more dissection, all the time knowing that an important structures may be lurking nearby. Colon surgery requires the surgeon to be aware that the ureter and iliac artery and vein are just behind the bowel; biliary tract surgery requires cognizance of the proximity of the common bile duct, hepatic artery, inferior vena cava, portal vein, duodenum and pancreas. The spleen is always hanging around gastric and pancreatic surgery. A sense of where you are becomes important in almost all operations.

All surgeons must be aware of the potential pitfalls of each operation they perform. Some surgeons have this “sixth sense” that tells them to be careful, to dissect gingerly as catastrophe and disaster may be only a small snip away.
This “sense of where you are” is honed by experience. It isn’t “evidence based,” but it is real and helps make surgery cleaner, quicker and safer.