ABSTRACT
The starting point for the study is the idea that many practices rely on specific methods that regularly evade formalized accounts. Some techniques are considered too trivial or idiosyncratic even when providing descriptions of the work intended as instructions. This chapter analyzes such a case taken from endovascular surgery: a form of image-guided intervention that relies on angiography and fluoroscopy imaging modalities. In this practice, surgeons must repeatedly move between different images while still remembering certain visualized features that are now lost from view. Some procedures to overcome this challenge have been outlined in the medical literature. We describe an additional method, which is de facto used in practice while still residing outside of the formally recognized methods of that practice. The technique relies on the creative use of a computer cursor as a visual aid for marking locations in the images. This workaround is built on local practices and technologies and is now an integral part of how the work gets done. It operates as a form of instructed action: a series of activities prospectively oriented to creating a shared phenomenal field by and for the collaborating surgeons.
