Swallow Magnetic Resonance Imaging Compared to 3D-Computed Tomography for Pouch Assessment and Hiatal Hernias After Roux-en-Y Gastric Bypass

Introduction/Purpose Weight regain and weight loss failure after bariatric surgery are important issues that may require a weight regain procedure. Three-dimensional-computed tomography (3D-CT) is a well-established method allowing exact measurements of pouch volume. The aims of this study were to prove the applicability of swallow MRI as a non-ionizing procedure and compare it to 3D-CT in patients after weight regain procedures following RYGB. Materials and Methods Twelve post-RYGB patients who had a follow-up operation for weight regain before 12/2017 were included in this prospective study. Swallow MRI and 3D-CT were performed in each patient to evaluate the size of the anastomosis, pouch volume, and intrathoracic pouch migration (ITM). Results Mean pouch volume in swallow MRI and 3D-CT were 40.4 ± 21.0 ml and 43.5 ± 30.2 ml, respectively (p = 0.83), and pouch diameter at the maximal distention was 35.3 ± 5.9 ml (MRI) and 31.0 ± 10.0 ml (CT) (p = 0.16). The rate of ITM was 75% in both examinations (p = 1.0). Conclusion Swallow MRI is a valid method for the assessment of pouch volume in different phases of the swallowing process and is comparable to 3D-CT. The diagnosis of ITM using swallow MRI was equal to 3D-CT.

Ex Vivo Anatomical Characterization of Handsewn or Stapled Jejunocecal Anastomosis in Horses by Computed Tomography Scan

The aim of this study is to compare handsewn and stapled jejunocecal anastomosis with different stomal lengths in terms of anatomical differences. Group 1 underwent a two-layer handsewn jejunocecal side-to-side anastomosis (HS); Group 2 received a stapled jejunocecal side-to-side anastomosis (GIA). Each group was divided into two subgroups (HS80 and HS100, GIA80 and GIA100). Specimens were inflated and CT scanned. The stomal/jejunal area ratio and blind end pouch volume/area were measured and compared. Effective length of the stoma was measured and compared with the initial length. Stomal/jejunal area ratio was 1.1 for both 80 techniques, 1.6 for the GIA100, and 1.9 for the HS100 technique. Both HS and GIA techniques produced a blind end pouch and exhibited a mean increase of the final stomal length ranging from 6 to 11% greater than the original stomal length. All techniques will exhibit a length increase of the final stomal length compared to the intended stomal length, with a consequent increase in stomal area. Stapled techniques consistently produced a large distal blind end pouch. Length of a jejunocecal anastomosis should be selected in accordance with the diameter of afferent jejunum, and the 80 mm stomal length could be deemed sufficient in horses.

The gular pouch in northern hemisphere parasitic lampreys (Petromyzontidae)

The gular pouch is a large structure, of unknown function, that is present in sexually mature males of two parasitic species of southern-hemisphere lampreys. Our study showed the presence of a similar structure, of much smaller size, in both spawning and prespawning males and females in seven parasitic species of northern-hemisphere lampreys. Homology between the structure present in southern-hemisphere and northern-hemisphere lampreys was established based on the position of the pouch in the gular region and the fact that northern-hemisphere and southern-hemisphere lampreys have a sister-group relationship. The presence of lipids in the gular pouch was established in prespawning specimens of Entosphenus tridentatus (Gairdner in Richardson, 1836) and Petromyzon marinus L., 1758. The proposed hypothesis is that these lipids act as an energy source to sustain these two anadromous species during their protracted spawning migration. The hypothesis that the gular pouch is used to help carry stones for nest building was tentatively rejected pending further testing, because despite having a much smaller gular pouch, P. marinus has been observed carrying much larger stones than those carried by Geotria australis Gray, 1851. The statistically significant difference in gular-pouch volume between spawning males and females of P. marinus suggests that males use their larger pouch for courtship display. The gular pouch possessed a single lumen in the genera Ichthyomyzon Girard, 1858, Petromyzon L., 1758, and Caspiomyzon Berg, 1906, as in southern-hemisphere lampreys, whereas it comprised two lumens in the genera Entosphenus Gill, 1862 and Lampetra Bonnaterre, 1788. This is phylogenetically significant, as the two lumen gular pouch, interpreted as the derived condition, identifies a major clade of northern-hemisphere lampreys.