Parathyroidectomy after kidney transplantation Ferreira GF et al. The present study aimed to compare acute and long-term renal changes in patients undergoing either total parathyr- oidectomy and immediate autotransplantation or compar- able general surgical operations in a larger subset of kidney transplant patients. METHODS The study was a retrospective case-controlled study of renal allograft recipients at a single institution. This study was part of a project approved by the Institutional Ethical Committee on research. Records from all patients who received a kidney transplant at the University of Sa˜o Paulo, Hospital das Clinicas, between January 2000 and December 2006 were reviewed. A total of 905 patients were analyzed which may be compared to the 715 patients who received kidney transplants in the five year period 2002-2007 covered by the official registry of the Institution.9 Kidney transplant patients who underwent a total parathyroidectomy with autotransplantation for persistent HPT or for HPT devel- oped after transplantation were designated the case group. The control (non-parathyroidectomy) group consisted of renal transplant cases submitted to elective abdominal operations. Figure 1 shows patient selection. The following subjects were excluded from the final analysis: patients with infected abdominal surgeries and patients who received their parathyroid or abdominal surgeries at other centers. The demographic data, cause of renal failure, type of renal pre-transplant replacement therapy, type of donor, immunosuppressive therapy, dialysis duration before trans- plantation, time from transplantation to surgery, serum creatinine levels and estimated creatinine clearance were analyzed. Creatinine clearance was estimated using the Cockroft-Gault equation. Creatinine levels were compared at baseline (i.e., before the operation), in the early post- operative period (i.e., the highest value obtained during the first week after the operation) and in the long-term follow up. All patients were followed until the first occurrence of renal transplant failure (defined as the need for renal replacement therapy or preemptive renal retransplantation), death or 1 January of 2007 (end of study). Statistical analyses for continuous variables are presented as mean ¡ standard deviation in cases in which the CLINICS 2011;66(3):431-435 distribution is parametric. Student’s t test was employed to verify possible differences between groups. Contingency tables were created for qualitative variables and were tested by Fisher’s Exact Test or the chi-square test, as appropriate. RESULTS Between January 2000 and December 2006, 28 of 905 renal transplant patients at our transplant outpatient clinic underwent parathyroidectomy because of persisting hyper- parathyroidism, resulting in a period prevalence of 3.1%. Nine patients were excluded from the evaluation because they underwent parathyroidectomy at other centers. During the same period, 62 patients underwent abdominal surgery. Of those, 26 had non-elective operations, and procedures took place in other centers; these were excluded from the present analysis. The 19 patients with persistent HPT underwent parathyr- oidectomy due to hypercalcemia. The 19 patients in the control group received general and urological operations as follows: herniorrhaphy in 9, radical prostatectomy in 4, transurethral prostatectomy in 2, 1 cholecystectomy, 1 laparoscopic nephrectomy, 1 open nephrectomy plus chole- cystectomy and 1 open herniorrhaphy plus cholecystectomy. Renal replacement therapy before transplantation consisted of hemodialysis in 95% of the parathyroidectomy group and 89% of the control group. None of the cases in the study group underwent peritoneal dialysis before transplantation as compared with 5% of the control group. The remaining patients in both groups had pre-emptive renal transplanta- tion, with no significant differences in mean time on dialysis or mean time of surgery after renal transplantation. The mean time on dialysis before renal transplantation was 86.1 (range 0-204) months in the parathyroidectomy group and 57.2 (range 0-120) months in the control group (p = 0.047). The mean time for surgery after renal transplantation was 34 months (range 7–69 months) for the parathyroidectomy group and 26.9 months (range 3-76) for the control group (p = 0.23). The cause of chronic renal failure was glomerulonephritis or vasculitis in 47% of the patients undergoing parathyr- oidectomy and in 37% of the controls. Hypertensive disease induced renal failure in 26% of the study cases and in 21% of the controls. Cystic, hereditary or congenital diseases were Figure 1 - Patient Selection (PTX = Parathyroidectomy). 432