SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE MAGNETOMETER FOR DIAGNOSIS OF ISCHEMIA CAUSED BY MESENTERIC VENOUS THROMBOSIS

Although mesenteric venous thrombosis carries a better prognosis than arterial thrombosis, mortality and morbidity are still high, Previous studies have shown that the basic electrical rhythm (BER) of the bowel decreases early after induction of arterial ischemia. Furthermore, ou r studies have shown that these changes occur prior to pathologic chan ges and that they can be recorded noninvasively using a superconductin g quantum interference device (SQUID). SQUIDs measure magnetic fields that are created by the electrical activity of the gastrointestinal sm ooth muscle and have been used to measure the BER of the small intesti ne in human volunteers. This study was conducted to determine if a SQU ID could be used for early noninvasive detection of mesenteric venous ischemia in an animal model. Simultaneous recordings from serosal elec trodes and a SQUID outside the abdomen were taken from anesthetized Ne w Zealand rabbits. Recordings were made for 15 minutes before and 90 m inutes after injection of thrombin into the superior mesenteric vein, The basic electrical rhythm of the small bowel dropped from 16.42 +/- 0.69 to 8.80 +/- 0.74 cycles per minute at 30 minutes and to 6.82 +/- 0.722 after 90 minutes (p < 0.0001, paired t-test). The correlation co efficient between the SQUID and electrical recordings was 0.954 (p < 0 .0001). These data suggest that the ischemia caused by mesenteric veno us thrombosis results in changes in the bioelectrical activity, which can be noninvasively detected using a SQUID.