Background: Ileal dysfunction, and resection or exclusion may affect intestinal bile acid resorption resulting in alterations in serum lipid concentration. In restorative proctocolectomy, the different procedures may involve the ileum in all three ways.
Aim: The aim of the present study was to analyse possible changes of the blood lipid profile during the different steps of restorative proctocolectomy operative procedure.
Method: There were nineteen elective patients on their ordinary diet and 19 emergency patients on total parenteral nutrition. The former group were primarily operated on with colectomy; ileoanal pouch and loop ileostomy while the later group had had an emergency colectomy and terminal ileostomy before the pouch operation. Thirty five of the patients had ulcerative colitis, 2 had familial colon polyposis and 1 familial cancer syndrome. Blood specimens were collected in the mornings with the patients in a fasting state. The emergency patients were on unchanged ordinary diet during the preoperative period. Serum cholesterol and triglyceride were determined by enzymatic methods. Lipoproteins, studied only in the elective patients, were analysed by a combination of ultracentrifugation and precipitation. Student's t-test with Bonferroni's correction for multiple comparisons was used for statistic calculations.
Results: Preoperatively, the emergency group had significantly lower serum cholesterol but not serum triglycerides values compared to the elective group. This finding is probably due to difference in the preoperative nutrition. The cholesterol levels among patients who received steroids in the two groups were compared and found to be significantly lower in the emergency group. Later, no significant differences concerning cholesterol and triglycerides were found between the groups. The cholesterol level was not significantly different in the elective group between patients who receive hydrocortisone and those who did not. During the period with loop ileostomy cholesterol was significantly lowered while the triglycerides were significantly increased compared to the preoperative values of the elective group. The decrease of serum cholesterol levels was correlated to the length of the excluded ileum. During the same period alpha-lipoprotein decreased significantly and reached values below the normal of the reference material. Beta-lipoproteins, which were subnormal already preoperatively, increased but not significantly. Pre-beta-lipoproteins were at the same level at all stations. At 12 months with functioning pouches all analysed values, with the exception of beta-lipoproteins. were within the normal limits set by the reference material. In the emergency group the patterns for triglycerides and cholesterol were similar but for the preoperatively depressed cholesterol values. After 12 months with functioning pouch the serum cholesterol and triglycerides were at the same level as for the elective patients.
Conclusion: A serum lipid profile was studied in patients undergoing restorative proctocolectomy. Serum cholesterol and alpha-lipoprotein decreased and triglycerides increased when the patients had a diverting loop ileostomy. At 12 months after it's closure and with a functioning pouch, the patients had the same profile as the elective patients preoperatively, and with exception of beta-lipoproteins within normal limits in spite of the loss of the colon and the construction of a pouch of the distal ileum.