Bariatric surgery prior to pancreas transplantation: a retrospective matched case-control study

Background: The clinical impact of bariatric surgery (BS) prior to pancreas transplantation (PTx) is unclear.

Setting: University of Minnesota Hospital, Minneapolis, MN.

Methods: This was a single center retrospective case-controlled study of all patients January 1, 1998 and May 1, 2024 with a history of BS prior to PTx. Patients were matched (1:3) with control patients by recipient age, body mass index (BMI) at PTx, type of transplant, primary versus retransplant, and year of PTx.

Results: Among 1542 transplants, 17 patients had a history of BS prior to PTx, with an overall incidence of 1.1%. Eleven patients underwent roux-en-y gastric bypass, 5 underwent sleeve gastrectomy (SG), and one underwent vertical-banded gastroplasty. Eleven underwent simultaneous pancreas kidney transplant, 5 underwent pancreas transplant alone, and one underwent pancreas after kidney transplant. The median time (interquartile range [IQR]) between BS and PTx was 2.9 yrs (4.6) and ranged from .7 to 20.6 yrs. Compared to the non-BS group, patients in the BS group had similar rates of graft thrombosis (5.9% versus 3.9%, P = .76) and rejection (29.4% versus 29.4%, P > .99). Length of stay following PTx (P = .22), number of 30-day readmissions (P = .24), and number of 1-year readmissions (P = .70) were not different between the two groups. Median death-censored graft survival (9.4 yrs versus median not reached, P = .23) and patient survival (9.4 yrs versus median not reached, P = .18) were similar between the BS and non-BS groups. Finally, six patients underwent BS with the specific intention of reaching the acceptable BMI threshold for PTx. Median BMI was reduced from 37.4 prior to BS to 26.4 at time of PTx. Median time from BS to PTx was 2.4 yrs. At 4 yr follow-up, graft and patient survival was 100%.

Conclusions: This represents the largest series of patients with BS prior to PTx. Perioperative complications are not increased in patients undergoing PTx with a history of prior BS and long-term outcomes are equivalent. Patients with a prohibitive BMI for PTx eligibility should be considered for BS without concern for detrimental effect on post-transplant outcomes.