MO414ACUTE KIDNEY INJURY AFTER ELECTIVE ENDOCRINE SURGERY: ARE PATIENTS WITH PRIMARY HYPERPARATHYROIDISM AT RISK?

Abstract

Abstract Background and Aims Development of acute kidney injury (AKI) after elective endocrine surgery is underreported. We aimed to assess the prevalence of AKI among patients underwent surgery for primary hyperparathyroidism (PHPT) and thyroid surgery and compare risk of AKI between these cohorts. Method A retrospective cohort study included 299 patients who underwent successful selective parathyroidectomy (PTx) for PHPT, and 40 patients after thyroid surgery with comparable scope of the intervention (thyroid follicular cells tumor, non-invasive papillary thyroid carcinoma). AKI was defined according to KDIGO-2012 criteria. Results Change of serum creatinine before/after surgery differed significantly between PHPT and thyroid surgery group: type of surgery*time interaction p<0,0001 (repeated measures ANOVA after Box-Cox transformation) – fig.1. 109 patients (36,5%) in the PHPT group and 2 patients (5%) in the thyroid group met AKI criteria after PTx. Most of the patients developed AKI stage 1. Risk of AKI was significantly higher in the PHPT patients: RR=7,3 [2,19; 26,6], OR=10,9 [2,82; 46,6], р<0,0001. Patients in the thyroid surgery group were significantly younger than those in the PHPT group (41,5 [Q1-Q3: 30; 51] years vs 59 [Q1-Q3: 50,8; 67] years, respectively, p<0,0001), had higher mean baseline estimated glomerular filtration rate (eGFR) (91,1 ± 18 vs 78,8 ± 18,6 ml/min/1,73 m2 respectively, p=0,0001) and had less comorbidity index (p<0,0001). Hypertension encountered much more often in PHPT group vs thyroid group (69% and 22,5%, respectively, χ2 p<0,0001). Duration of surgery also differed between groups: 25 min [Q1-Q3: 20; 40] min in PHPT group vs 50 [Q1-Q3: 31; 62,5] min in thyroid group, p<0,0001. We hypothesized that acute decline of parathyroid hormone after PTx increases risk of AKI in the PHPT group. To evaluate whether type of surgery (PTx/thyroid surgery) is independently associated with risk of AKI, we used 1:1 pseudorandomization (Propensity Score Matching, “matchit” package, “nearest” method in R) to balance the baseline characteristics (age, BMI, comorbidity, baseline eGFR, duration of surgery, presence of hypertension). The 40 patients in the thyroid surgery group were matched to 40 patients in the PHPT group according to these confounders. After PSM the prevalence of AKI remained significantly higher in the PHPT group than in the thyroid surgery group (30% vs. 5%, respectively, RR=6 [95%CI: 1,7; 23,1], p=0,006), confirming that PTx is the independent risk factor of AKI. Conclusion We observed higher prevalence of AKI after PTx for PHPT comparing with patients after thyroid surgery. Our data suggests that PTx itself is the main risk factor of AKI development after elective endocrine surgery.