A biomagnetic assessment of colonic electrical activity in pigs.

The electrical control activity of the large intestine was recorded in six pigs using a SQUID magnetometer. The study was performed in pre- and post-colectomy/sham-colectomy conditions. The biomagnetic field associated with colonic ECA changed drastically in subjects that underwent the colectomy procedure, whereas the signal for the control animals was nearly unchanged. Power spectral analysis was used to determine the average changes of dominant frequency and amplitude between baseline versus colectomy and sham-colectomy conditions. The dominant frequency was increased by 68 +/- 24% (versus 2 +/- 3% in control). The amplitude was decreased by 69 +/- 24% (versus 13 +/- 17% in control). This is the first study of transabdominal magnetic fields associated with colonic ECA, suggests some of the side effects generated in colectomy surgery and shows the utility of the biomagnetic technique in studies of the large intestine.

Selection criteria for laparoscopic cholecystectomy in an ambulatory care setting.

BACKGROUND: The ambulatory care center offers patient convenience and reduced costs after uneventful laparoscopic cholecystectomy. METHODS: A prospectively accumulated database of 1,750 cholecystectomies performed by one surgeon in a hospital setting was analyzed to test criteria for ambulatory cholecystectomy. Proposed criteria included age less than 65, absence of upper abdominal operations, and elective operations in healthy patients at low risk for common bile duct stones. RESULTS: Of 1,750 cholecystectomies, only 605 patients met all criteria for outpatient care. Discharge (from the in-hospital setting) was accomplished within 24 h of operation in 92% (first 3 years) and 98% (last 4 years) of selected cases. Only one patient (0.2%, 1/605) was converted to an open procedure; another was readmitted 30 h postoperatively with hemorrhage from the liver bed. CONCLUSIONS: Laparoscopic cholecystectomy can be performed safely in an ambulatory care setting, given careful selection and education of patients and documented experience of the surgical team.