No abstract

Introduction: Several pre and post-transplant factors are known to contribute for the higher incidence of osteopenia-relatedfractures in both trabecular and cortical bone after simultaneouspancreas-kidney (SPK) recipients, including diabetic condition,dialysis, renal insuffi ciency, hyperparathyroidism, low boneturnover and steroid use; however, the infl uence of chronicmetabolic acidosis and its related calcium metabolism derangementsecondary to bladder drainage of the duodenopancreatic graft hasnot been reported as a risk factor. Patients and Methods: To support our observation, we performed aretrospective study with all 80 SPKs performed at our institution from1992 to 2005. 37 cases were bladder-drained (BD) with a conventional sideto side extraperitoneal duodenocystostomy for control of pancreaticexocrine fl uid and 43 had an enteric drainage (ED) through aduodenoileostomy. Both groups had comparative demographic features interm of sex, age, time in dyalisis, length of the diabetic condition.There were not patients treated with biphosphonates post-transplant. Allcases received a calcineurin-inhibitor based quadruple immunosupressivetherapy. Results: Four recipients with bone fractures were identifi ed in the ED group (9.3%) and ten cases in the BD group (27%) with a statisticalsignifi cance. Comparable patient and graft survival were found in bothgroups. All pancreas grafts except one had endocrine function at the timeof the fracture, and all BD recipients were on oral sodium bicarbonatereplacement. The average from the time of the transplant to the time ofthe fracture was 62.1 months (12-120) for the BD group compared to 15months (12-24) for the ED group. The most common site for fractures wasankle long bone (30%) followed by radius (20%). femur (20%). calcaneus (10%). middle foot (10%) and forefoot (10%) in the BD group; the mostcommon fractured bone in the ED group was the femur (50%). followed bythe ankle (25%) and the middle foot (25%). Conclusions: We found bladder-drained SPKs to have a triple-foldincidence of bone fractures when compared to enteric drained recipients.Osteoporosis is prevalent in the pre-transplant population waiting for akidney or a SPK and in the post-transplant population regardless of theorgan involved, thus they are at increased risk of bone loss. Acceleratedosteopenia post-transplant is therefore expected as the cause for a highfracture rate in SPK recipients (as high as 49% in some series). Withcomparable demographics and immunosuppressive regimes employed for bothSPK recipient groups, we found statistically and clinically signifi cantthe higher incidence of bone fractures in the BD group, making thissubset of patients at particular risk for this condition and thereforefor the need of increased surveillance. Attention must be paid tostrictly correct both metabolic acidosis and to improve bone fi tness bothpharmacologically and with physiotherapy in this fragile population.