Parathyroidectomy: Whom and when?
Jofre R, Manuel J, Gomez L et. al. Kidney Intl. 2003; 63 (Suppl.85):S97-S100
To evaluate the surgical outcomes of total parathyroidectomy (PTX) with autotransplantation (AT) into the forearm in dialysis patients.
Study design and study population
This was a retrospective descriptive analysis of 148 patients on dialysis in a single center (Buenos Aires, Argentina) - who were treated with PTX because of severe 20 HPT, refractory to medical management. A brief demographic comparison was made with 309 dialysis patients in the same center, but not undergoing PTX.
Intervention or observation
Total PTX of all 4 PT glands with excision of peri-glandular fatty tissue, excision of thymic remnant tissue, and exploration of the carotid sheaths; AT of a fragment of the least nodular gland into the forearm. The time frame covered 1999 to 2002; the prevalent center dialysis population was approximately 350 patients.
Indications for PTX: persistent serum PTH levels > 70 pmol/L and hypercalcemia and/or hyperphosphatemia; patients refractory to vitamin D sterols – i.e. requiring repeated withdrawal to manage hypercalcemia/hyperphosphatemia; ruptured quadriceps tendon (n=4); calciphylaxis (n=0);
Baseline laboratory values included serum PTH of 140 ± 50 pmol/L and alkaline phosphatase of 737 ± 519 IU/L.
Compared with the Non-PTX group, patients selected for PTX were younger (mean age 45 vs. 62 yrs.), less likely to be diabetic (1% vs. 19%), and had been dialysed for longer (9 vs. 6 yrs.).
All 4 PT glands were identified in 129 patients (88%), and treated with total PTX plus AT. In the remaining 19 patients (12%), partial PTX was performed because the full complement of glands could not be found; of these an ectopic mediastinal PT gland was subsequently discovered by 99mTc-MIBI scanning in 6 (4%).
Immediate post-operative surgical complications were; 1 death (cardiac); significant local bleeding (n=1); permanent hoarseness (n=1); “hungry bone syndrome” (20%).
Within the entire PTX cohort of 148 patients, serum PTH levels were reported over time;
* i.e those remaining on dialysis
Within the original total PTX cohort of 129 patients, recurrence of 20HPT (serum PTH > 25 pmol/L) occurred in 21 patients (16%) by 3.1 ± 2.3 yr; this was treated by removal of the AT remnant in 13 and medical management in 8. Of the remaining 108 patients serum PTH was judged satisfactory (serum PTH < 20 pmol/L)
Within the partial PTX cohort of 19 patients, 4 were re-operated, 7 had satisfactory control of 20 HPT (serum PTH < 25 pmol/L), while 8 had significant persistent 20HPT (serum PTH > 75 pmol/L)
This was an observational study, involving a large cohort of dialysis patients treated for severe 20 HPT within a single South American center. The discussion argues that this surgical outcome is representative of other reports of total PTX with AT. However it does not provide guidance as to which of several existing surgical approaches provides optimal long-term control of 20 HPT, refractory to medical management. These include a) Total PTX, b) 3½ PTX with AT into the forearm, and c) 3½ PTX leaving a small remnant in situ.
Impact on practice
While this report clearly outlines the expected clinical outcomes from total PTX with AT in this dialysis center, there are frequently very large between-center differences in the severity of both CKD-MBD, and local surgical approaches. For example, this center appeared to be performing 10-12 PTX surgeries / yr. from a dialysis population of around 350 patients; the PTX group clearly had significant prevalent bone disease (baseline mean serum alkaline phosphatise 737 IU/L, 20% post operative hungry bone syndrome) This is a succinct and useful report of a very complex issue, but it leaves open the questions still surrounding the management of severe 20 HPT