We found that our novel guidewire instrument has a high agreement reliability in comparison with the gold standard Olympus calibration device. This high agreement reliability is maintained for both expert and novice raters. In addition, no patients demonstrated any complications during the measurement procedures in this sample. These results are important in that the gold standard Olympus device is not only expensive, but of difficult acquisition in developing countries. Our novel device should therefore increase access to this measurement procedure.
In an attempt to avoid weight regain, reducing the diameter of a dilated anastomosis may lead to a reduction of up to 23% in weight [10]. Most studies will recommend a 20 mm diameter, although diameters as small as 12 mm have been proposed [11]. Despite this growing body of evidence regarding the importance of the anastomosis diameter, the literature can be challenged if the measurement process has not been properly validated.
Our results are clinically relevant to clinical practice since approximately 20–30% of all bariatric patients regain weight, many of these being addressed through an endoscopic procedure [12, 13]. The precision in these procedures is essential, in that an anastomosis with a diameter smaller than 5 mm would prevent patients from digesting liquids, a diameter smaller than 10 mm would prevent patients from digesting solid food, while diameters greater than 14 mm are associated with weight regain [11, 14]. The margin for error is therefore small, thus requiring not only measurement precision but also a high degree of reliability across measurements. In addition, it is important for clinicians to communicate with patients so that they can be informed about the current status of their procedure, but also participate in decisions that will affect their ability to eat and drink [15, 16]. In addition, this novel device increases access to this measurement method in countries where the traditional device is either difficult to find or expensive to incorporate into clinical practice.
Although we propose a new and inexpensive and reliable method for measuring dilation, our study does have limitations. First, we evaluated the reliability of videos rather than conducted new endoscopic procedures. While conducting procedures on the same patient by different endoscopists would enhance our methodology, this methodology would pose risks and discomfort to our patients, and was therefore avoided. Second, our sample was small and restricted to a single center. Future studies should therefore further validate our results with more representative samples.
In summary, our study presents a novel, simple, safe, accurate and inexpensive method to measure the outlet diameter. These findings are relevant in that the gold standard Olympus calibration device is not only of difficult access in a number of countries, but also expensive. Given that we have demonstrated equivalent measurement reliability between the Olympus device and our new guidewire, both with experienced endoscopists and trainees, we recommend its use in clinical and research practice.