Transmitted Light Tissue Thickness Analysis (TiLTT)

The most common surgical procedure for weight loss is the sleeve gastrectomy. The
laparoscopic sleeve gastrectomy (LSG) involves the linear stapling of the stomach using a
stapling device [e.g. Echelon (Ethicon Somerset NJ)] fired multiple times along the length
of the stomach thereby excising 80-90% of the stomach leaving the patient with a "sleeve" of
stomach rather than the normal anatomical pouch. The gastric wall varies in thickness and
thus there are a varied staple sizes available for this use. Staple sizes range from
2.0mm-5.0mm in height. In standard surgical practice the surgeon chooses the size of staple
cartridge for each subsequent firing based on his experience and estimations about the
thickness of the stomach tissue in any given region. The drawback of this technique is that
it is highly inaccurate. If the surgeon's estimation is in error, the staple height chosen
may be either too tall or too short leading to bleeding or leakage from between the staples
or malformed/unformed staples leading to staple line failure. Any of these errors can lead
to devastating complications such as hemorrhage, leak, sepsis and death. To date there is no
objective way to measure the thickness of the tissue being stapled and thus staple choice
relies entirely on surgeon estimation which is inherently inaccurate. The investigators
hypothesize that a light source placed in the stomach lumen will transmit light through the
gastric wall. The amount of light transmitted, i.e. visible to an imaging device arrayed
external to the stomach, will be directly proportionate to the thickness of the stomach.
This study will take advantage of the fact that during routine procedures in the sleeve
gastrectomy procedure a lighted tube is placed into the gastric lumen via the mouth. This
device is called the Gastrisail and has 10 separate LED lights arrayed along its length.
This allows for the measurement of transmitted light intensity through the gastric wall at
10 individual locations along the length f the stomach. In addition this study will take
advantage of the fact that during standard practice in a sleeve gastrectomy a section of the
stomach corresponding to the location of the lights is excised and sent for pathological
evaluation. This will allow us to measure the actual thickness of the stomach at 10 points
corresponding to he locations of the transmitted light intensity. For this measurement The
investigators will use a standardized and validated measurement tool/calipers. Now with two
sets of numbers the investigators plan to correlate the degree of transmitted light
intensity with actual thickness measurements and thereby reach an algorithm which will allow
the transmitted light intensity data alone to predict gastric wall thickness. This will
provide the surgeon with an entirely non-invasive objective measure of gastric wall
thickness and hopefully improve his/her choice of staple size during these surgical
procedures thus improving safety.

Inclusion Criteria:

- Subject has provided informed consent

- Subject is between the ages of 18 and 80 years of age

- Subject is scheduled for and undergoes primary sleeve gastrectomy

Exclusion Criteria:

- Revisional Bariatric Surgery