Adverse effects of jejunoileal bypass on growth and development.

Ninety percent jejunoileal bypass was performed in 20 growing (100 gram) male Sprague-Dawley (SD) and 15 male, genetically obese, growing (125 gram) Zucker "fat rats" (FR). Twenty SD and 15 FR unoperated rats of similar age and weight served as controls. Animals were evaluated for weight gain or loss, complications, and survival. At death (4 months), caliper measurements of long bones, vertebral column, pelvis, and skull were obtained, and brain, liver, spleen, and kidneys were excised and weighed. Liver and gonadal histology were obtained. The "fat fat" was more fragile, with a 20 percent anastomotic leak rate and a 33 percent mortality rate. The mortality rate was 5 percent (SD) and zero in controls. Bypassed animals showed growth retardation with weight of SD rats 31 percent (p less than 0.05) and FR's 19 percent of controls (p less than 0.05). Organ weights (liver, spleen, kidneys) were similar, except for a smaller brain in bypassed rats [SD 1.06 +/- 0.08 to 1.83 +/- 0.08 Gm. control (p less than 0.05), FR 1.2 +/- 0.12 to 1.68 +/- 0.09 control (p less than 0.025)]. Skeletal development was retarded significantly in bypassed rats [vertebral column, 125.9 +/- 3.5 to 138.3 +/- 3.9 mm. in controls (p less than .025); ilium, 39.4 +/- 1.1 to 46.2 +/- 1.5 mm. in controls (p less than 0.05); skull circumference, 20.2 +/- 0.03 to 22.5 +/- 0.05 mm. in controls (p less than 0.025)]. No increase in fatty infiltration of liver was observed. Spermatogenesis was diminished 30 percent (p less than 0.05) in bypassed (SD) animals. The data document significant morbidity and mortality rates, growth retardation, and diminished spermatogenesis in bypassed "adolescent" rats. These results imply that jejunoileal bypass may affect intellectual, skeletal, and reproductive development adversely and question the advisability of these procedures in growing subjects.