For kidney transplant recipients with persistent or recurrent hyperparathyroidism (HPT), parathyroidectomy is highly effective with a low complication rate.
R.R. Dulfer, MD, of University Medical Centre Rotterdam in The Netherlands, and colleagues performed a systematic review of 47 mostly observational studies on surgery or medical therapy for variably defined tertiary HPT. Based on data from 14 studies including a total of 240 surgical patients, subtotal and total parathyroidectomy (with or without autotransplantation) initially resolved HPT in 98.7% and 100%, respectively. Afterward, HPT recurred in 7.6% and 4%, respectively.
By comparison, off-label treatment with the calcimimetic cinacalcet resolved hypercalcemia with elevated parathyroid hormone in 80.8% of 297 patients from 11 studies. Doses of cinacalcet ranged from 30 to 180 mg daily and treatment periods varied widely.
“Although high-quality evidence is lacking, this systematic review shows that surgical treatment for HPT appears to be more effective than medical treatment,” Dr Dulfer and the team wrote in the British Journal of Surgery. The relative costs of the treatments still need to be assessed.
Persisting hypercalcemia or side effects such as hypocalcemia, gastrointestinal intolerance, or paresthesia prompted 6.4% of an all-inclusive group of cinacalcet users to discontinue the drug. Few complications occurred among surgery patients. Besides hypocalcemia or persistent hypercalcemia, several patients reported vocal cord paralysis, pneumonia, or postoperative hematoma.
Although investigators observed a permanent decline in renal function following surgery, they found no effect on overall graft survival based on limited evidence. Graft survival rates at 3 and 10 years post-transplant were similar for patients who underwent parathyroidectomy and those who did not. Renal graft function seemed relatively stable during cinacalcet therapy.
Substantive research on tertiary HPT, including controlled trials and direct comparisons of treatments, is still needed in many key areas. “Higher-quality data on important clinical endpoints such as cardiovascular morbidity and renal bone disease are lacking,” Dr Dulfer and colleagues noted. “Future research should include randomized trials focusing on clinical endpoints such as quality of life, cardiovascular morbidity and renal bone disease, so that the optimal treatment for an individual patient can be chosen.”
Dulfer R, Franssen G, Hesselink D, et al. Systematic review of surgical and medical treatment for tertiary hyperparathyroidism. Br J Surg. 2017;104:804-813. doi: 10.1002/bjs.10554.