First thing is to remind that 2D pictures give a surface and not  a good evaluation of volumen. for volumen you need a 3D picture, so a CT scan evaluation. The software existe, used by radiologic team for large hepatic resection. We have published the technique in SOARD and use it monthly every time we discuss a bariatric redo.

Kind regards

Pierre Verhaeghe MD, PhD, FACS, FIFSO

Jean-Baptiste Deguines, Pierre Verhaeghe,& al, Is the residual gastric volume after laparoscopic sleeve gastrectomy an objective criterion for adapting the treatment strategy after failure?, Surgery for Obesity and Related Diseases, Volume 9, Issue 5, September–October 2013, Pages 660-666, ISSN 1550-7289, http://dx.doi.org/10.1016/j.soard.2012.11.010.

Abstract: Background

Causes of failure after laparoscopic sleeve gastrectomy (LSG) are not known but may include a high residual gastric volume (RGV). The aim of this study was to use gastric computed tomography volumetry (GCTV) to investigate the RGV and relate the latter parameter to the outcome of LSG.

Methods

A single-center, prospective study included patients with>24 months of follow-up after LSG. The RGV was measured with a unique GCTV technique. We determined the LSG outcomes according to a variety of criteria and examined potential relationships with the RGV. When the RGV was>250 cc, we offered a repeat LSG (RLSG).

Results

Seventy-six patients were included. The mean RGV was 255 cc but differed significantly when comparing “failure” and “success” subgroups, regardless of whether the latter were defined by a percentage of excess weight loss>50 (309 cc versus 225 cc, respectively; P = .0003), a BAROS score>3 (312 cc versus 234 cc; P = .005), the Reinhold criteria (290 cc versus 235 cc; P = .019), or the Biron criteria (308 cc versus 237 cc; P = .008). The RGV threshold (corresponding to the volume above which the probability of failure after LSG is high) was 225 cc. Fifteen RLSGs were performed during the inclusion period.

Conclusion

A high RGV 34 months after LSG is a risk factor for failure. Knowledge of the RGV can be of value in the management of failure after LSG.

A good quality water soluble contrast study done on day 1 post-op can be used as a baseline. Patients can have the same study later during follow-up if they complain of weight gain and a very good like to like comparison can be made in the outpatient clinic and shown to the patient. I find this as a very helpful tool to prove/ disprove pouch dilatations or sleeve stretch.

Gastric volumetry by tomography

Thank you for your response, CT volumetry may change by intragastric  pressure, if stomach empties too fast, it won't fullfill. Any method should close the gastric outlet and measure intragastric pressure.