Impact of surgical parathyroidectomy on chronic kidney disease-mineral and bone disorder (CKD-MBD) – A systematic review and meta-analysis

For more than 6 decades, many patients with advanced chronic kidney disease (CKD) have undergone surgical parathyroidectomy (sPTX) for severe secondary hyperparathyroidism (SHPT) mainly based historical clinical practice patterns, but not on evidence of outcome.We aimed in this meta-analysis to evaluate the benefits and harms of sPTX in patients with SHPT. We searched MEDLINE (inception to October 2016), EMBASE and Cochrane Library (through Issue 10 of 12, October 2016) and website clinicaltrials.gov (October 2016) without language restriction. Eligible studies evaluated patients reduced glomerular filtration rate (GFR), below 60 mL/min/1.73 m(2) (CKD 3–5 stages) with hyperparathyroidism who underwent sPTX. Reviewers working independently and in duplicate extracted data and assessed the risk of bias. The final analysis included 15 cohort studies, comprising 24,048 participants. Compared with standard treatment, sPTX significantly decreased all-cause mortality (RR 0.74 [95% CI, 0.66 to 0.83]) in End Stage Kidney Disease (ESKD) patients with biochemical and / or clinical evidence of SHPT. sPTX was also associated with decreased cardiovascular mortality (RR 0.59 [95% CI, 0.46 to 0.76]) in 6 observational studies that included almost 10,000 patients. The available evidence, mostly observational, is at moderate risk of bias, and limited by indirect comparisons and inconsistency in reporting for some outcomes (eg. short term adverse events, including documented voice change or episodes of severe hypocalcaemia needing admission or long-term adverse events, including undetectable PTH levels, risk of fractures etc.). Taken together, the results of this meta-analysis would suggest a clinically significant beneficial effect of sPTX on all-cause and cardiovascular mortality in CKD patients with SHPT. However, given the observational nature of the included studies, the case for a properly conducted, independent randomised controlled trial comparing surgery with medical therapy and featuring many different outcomes from mortality to quality of life (QoL) is now very strong.