Three Reasons to Sell Intuitive Surgical, Inc. (ISRG)

I’m going to attempt something a little odd today, Fools. Even though Intuitive Surgical, Inc. (NASDAQ:ISRG) makes up 6% of my real-life holdings, and I wrote just last week about why I’m holding my shares, I’m going to be giving you three reasons to consider selling the stock today.

Why am I doing this?

Recently, Nobel Prize winner Daniel Kahneman visited Fool headquarters in Virginia. While visiting, he talked about how a number of different biases can lead us to believe we can predict the future with relative certainty. In reality, he argued, we are just deluding ourselves.

It got me to thinking about how I don’t write enough about the risks of owning the stocks I own. So, though I don’t plan on selling my Intuitive Surgical, Inc. (NASDAQ:ISRG) stock anytime soon, I think it’s healthy for me to practice and model this behavior.

1. Questions from the medical community
Earlier this year,  the Journal of the American Medical Association came out with a paper questioning the benefits of using Intuitive’s da Vinci surgical robot in hysterectomies. Specifically, it found that complication rates for procedures performed robotically stood at 5.5%, while traditional methods had a rate of 5.3%. This was not deemed a statistically significant difference, but given that the da Vinci procedure was much more expensive, JAMA pointed out that the benefits of the da Vinci might not outweigh the costs.

Those worries were echoed a month later by the president of the American Congress of Obstetricians and Gynecologists. His basic argument, which can be read in full here, was that while there were certain benefits of robotic surgery, there were other methods that were cheaper and equally effective from an outcomes perspective.

As hysterectomies and other gynecological procedures make up just less than half of all those performed in 2012, major changes in hysterectomy protocol could significantly change Intuitive’s revenue streams.

2. No room left for growth
As it stands today, urological (mainly prostatectomies) and gynecological (mainly hysterectomies) procedures make up about 70% of all da Vinci procedures. As the da Vinci has continued to gain acceptance in the medical community, it is becoming more commonplace to have robotic surgery for these two operations.

Source: SEC filings.