Biodistribution of Technetium-99m Pertechnetate after Total Gastrectomy and Roux-en-Y Jejunal Pouch

ABSTRACT

This paper investigates the influence of total gastrectomy, with and without a jejunal pouch, on the biodistribution of the radiopharmaceutical Technetium-99m pertechnetate (^99mTcO₄⁻). A quantitative biodistribution study was performed on the 30th postoperative day in Wistar rats, using the Wizard PerkinElmer gamma counter. The percentage of injected radioactivity of ^99mTcO₄⁻ per gram of tissue (% ATI/g) in Roux-en-Y total gastrectomy rats was lower in the lung, brain, and femur, compared to the sham rats (p <.05). In the jejunal pouch rats, the%ATI/g was higher than in the jejunum of sham rats (p <.05). The biodistribution was higher in the lung, brain, and femur of Roux-en-Y pouch rats than in Roux-en-Y rats (p <.05). Serum levels of cobalamin, phosphorus, and calcium were lower in gastrectomized than in sham rats (p <.05). No significant histological change was observed in the jejunum of Roux-en-Y rats. In the jejunal pouch, we found vascular ingurgitation, inflammation, submucosal, and muscular wall hypertrophy and widening of the villi. In conclusion, total gastrectomy in rats affected the biodistribution of ^99mTcO₄⁻ to important organs, mainly when a Roux-en-Y reconstruction without a pouch was performed. Moreover, the operation caused biodistribution-related metabolic changes.

Keywords: :

• total gastrectomy
• biological availability
• pertechnetate
• jejunal pouch
• rat

ACKNOWLEDGEMENT

This paper was partially funded by a grant from CNPq (470862/07) Brazil.