Jejunoileal bypass for morbid obesity: studies of the long-term effects
1995 (English)Doctoral thesis, comprehensive summary (Other academic)
This study was aimed at investigating adverse and beneficial long-term effects of jejunoileal bypass (JIB) sugery in obese patients. The JIB was the first widly used surgical procedure for treatment of morbid obesity. The weight loss was remarkable, but the procedure was declared not appropiate for obesity surgery in the late 1970's. Serious late adverse effects such as liver cirrhosis and malignancies, have been postulated. Unexpectedly few studies have adressed these problems.
In the long-term follow-up of 87 uniformly operated patients, several persisting beneficial effects were found. The mean Body Mass Index was 41.5 kg/m2 at the time of operation and 29.7 kg/m2 sixteen years after the operation. Diabetes type II and hyperlipidemia, common in an obese population, was not found in this group. Reversals were performed in 3% of the patients in contrast to 20-30% in many earlier studies. Revisions performed in 8% of the patients due to excessive weight loss could have contributed to the good long-term outcome.
Percutaneous liver biopsies from 44 patients taken 14-20 (mean 17) years after JIB revealed normal or fatty liver, a lower degree of histological abnormalities than in 11 biopsies taken at the time of operations 1-14 (mean 6) years postoperatively. Liver cirrhosis seen early in one patient could not be found in the late biopsies.
Reduced activity of the fibrinolytic system has been shown to be a new cardiovacular risk factor. In 45 patients studied 14-20 years after JIB, the levels of both plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (tPA) were significantly lower than in a control group of 10 morbidly obese patients ( PAI-1: 8.4 vs 32 U/mL, tPA: 7.2 vs 12 pg/L).
Bile acids are regarded as cofactors in the carcinogenesis in the colon and experimentally an increased frequency of malignant tumors has been demonstated after JIB in carcinogen-induced rats. In 30 of the operated patients, colonoscopy with biopsy was performed 11-17 yeras after the operation. No evidence for malignant transformation was found as reflected by an abscense of polyp formation, histologic dysplasia or aneuploidia in flow cytometric DNA analysis.
Eight hundred and thirty patients from 10 hospitals subjected to JIB were compared to 1660 controls with respect to malignant diagnosis over a 20 years period. No significantly increased risk for colorectal carcinoma could be demonstrated. However the overall risk for malignant disease was increased in the operated patients. The frequency of endometrial carcinoma was significantly elevated up to five years after the operation but was normal after that time.
In conclusion the postulated progress of serious adverse effects of JIB such as liver cirrhosis and malignant disease has not been possible to demonstrate. Several beneficial effects such as weight loss and reduction of cardiovascular risk factors have been found a long time after the operation.
Place, publisher, year, edition, pages
Umeå: Umeå Universitet , 1995. , 53 p.
Umeå University medical dissertations, ISSN 0346-6612 ; 445
Jejunoileal bypass, Obesity, Surgery, Liver biopsy, Fibrinolytic system, Colonoscopy, Flow cytometry, Cancer risk
IdentifiersURN: urn:nbn:se:umu:diva-101354ISBN: 91-7191-121-9OAI: oai:DiVA.org:umu-101354DiVA: diva2:799850
1995-12-15, Sal D, byggnad ID, 9 tr (Tandläkarhögskolan), Norrlands Universitetssjukhus, Umeå universitet, Umeå, 09:00
Diss. (sammanfattning) Umeå : Umeå universitet, 1995, härtill 5 uppsatser.2015-04-222015-03-272015-04-22Bibliographically approved