The risk of hyperparathyroidism after the duodenal switch operation is related to the length of the common channel.
A retrospective analysis of patients following the duodenal switch operation from october 2, 2000, through february 1, 2002.
Academic tertiary referral hospital.
One hundred sixty-five consecutive patients underwent the duodenal switch operation, performed for morbid obesity, with common channel lengths of 75 cm (n = 103 [group a]) and 100 cm (n = 62 [group b]).
Main outcome measures
Weight loss and parathyroid hormone, corrected calcium, and 25-hydroxyvitamin d (25-oh d) levels were compared between groups a and b. values were determined preoperatively, early postoperatively (3-6 months), and late postoperatively (9-18 months).
Both groups exhibited a slight reduction in serum calcium concentration, with one quarter decreasing below the normal range. hyperparathyroidism was more common in group a than group b preoperatively (38.9% vs 14.9%), reflecting the higher body mass index of patients in group a. hyperparathyroidism was also more frequent in the early (54.9% vs 30.9%) and late (49.4% vs 20.5%) postoperative periods in group a vs group b. new-onset hyperparathyroidism was also more common in group a than group b (42.0% vs 13.3%). after 1 year, subnormal 25-oh d levels were found in 17.0% of the patients in group a and in 10.0% of the patients in group b. median 25-oh d levels increased in both groups, but tended to be higher in group b.
Patients with shorter common channels had a higher risk of developing hyperparathyroidism. this may be related to limited 25-oh d absorption.