Keywords
Parathyroidectomy, Primary Hyperparathyroidism, Intra-Operative
Parathyroid Hormone Monitoring, Parathyroid Adenoma, Operative Time
KEY POINTS
- IOPTH monitoring is a long-debated topic. Some advocate its use only
in specific clinical scenarios, while others advocate its use in every
focused parathyroidectomy.
- There was no significant difference in surgical success rates between
the ”IOPTH used” and the ”IOPTH not used” groups.
- Operating room time was significantly shorter in the ”IOPTH not used”
group.
- When two imaging modalities are concordant for the location of a
single adenoma, it appears that a focused parathyroidectomy without
IOPTH monitoring can be used safely.
- IOPTH monitoring should be used only in select cases.
INTRODUCTION
Primary Hyperparathyroidism (PHPT), a benign hormonal disorder
characterized by a high serum calcium concentration and an
inappropriately increased parathyroid hormone, is a relatively common
medical condition, with prevalence of 233 to 100,000 in women, and 85 to
100,000 in men.(1) Approximately 88% of cases are due
to single adenoma.(2)
The treatment of choice for PHPT is parathyroidectomy with a cure rate
of up to 99%.(3–7)
Over the last few decades, the minimally invasive parathyroidectomy has
gradually replaced the standard procedure – bilateral neck
exploration(8) – due to preoperative localization
techniques and intraoperative parathyroid hormone monitoring (IOPTH).
Although preoperative localization techniques vary, Ultrasonography (US)
and technetium Sestamibi scintigraphy (Sestamibi) reach a high
sensitivity rate of up to 90%.(6,9–11) Other imaging
modalities, such as Computed Tomography (CT) and MRI, are acceptable as
well.
The definitive treatment for PHPT due to single adenoma, is resection of
the affected gland. Cure is defined as a decline in calcium levels to
normal (8.4-10.5 mg/dL), six months post-surgery.
Pre-operative imaging for adenoma localization varies between centers
worldwide.
The routine use of IOPTH is a long-debated topic in the literature. In a
recent survey in the United States, 74% of surgeons responded they
always use IOPTH, regardless of the clinical
setting.(12)
The American Association of Endocrine Surgeons recommends performing
IOPTH in all parathyroidectomies.(13) Several studies
have shown that the use of IOPTH results in cure rates of
97-99%.(3–5) Furthermore, studies have also shown
that when IOPTH is not performed, there is a decline in operative
success.(5,13,14)
Notwithstanding the above, the European Society of Endocrine Surgeons
(ESES) recommends that when pre-operative localization with Sestamibi
and US is concordant for single gland disease, the use of IOPTH is of
little added value (evidence at levels Ib-III, recommendation grades
A/B).(15) Other studies have shown that when two
imaging modalities are concordant pre-operatively, there is no
difference in cure rates when IOPTH is not
used.(6,16,17) In addition, some studies have shown
that unrelated to imaging modalities, IOPTH usage does not change the
surgical success rates.(18–20) Furthermore, in a
study that examined 15,000 parathyroidectomies, the authors argue that
even 90% decline in IOPTH monitoring during surgery, cannot assure
cure. They suggest that all parathyroidectomies should be done with
bilateral exploration, without IOPTH monitoring.(21)
Regarding operating room time and operating room economics, a
comprehensive cost analysis published in 2010 showed that many
parameters should be taken into consideration when assessing the
cost-benefit of using IOPTH, the most important of which is the rate of
multi-glandular disease.(22)
A decade ago, a study published by our group demonstrated no added value
for IOPTH when US and MIBI are concordant.(6) Since
then, we have changed our practice and utilized IOPTH only in selected
cases (pre-operative imaging is not concordant; suspected multiglandular
disease; secondary or tertiary hyperparathyroidism; patients with a
diagnosis of MEN1 or MEN2A; revision surgery).
The main goal of the present study was to revisit our protocol following
10 years of experience, by investigating the cure rates of primary
hyperparathyroidism since the protocol had changed, compared to the
period when IOPTH was used routinely. The secondary goal was to
investigate if operating room time can be saved when IOPTH is not used.
MATERIALS AND METHODS