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Issues in parathyroid surgery
1. ISSUES IN PARATHYROID
SURGERY
Dr Sachin Katyal
Post Graduate Student
Department of General Surgery
MKCG Medical College, Berhampur.
2. AIM OF THE TOPIC
Aim of the topic is to highlight the clinical
features, diagnosis, and treatment of
parathyroid disease which have changed
radically over the past 25 years as a result of
technologic advances in the fields of
laboratory
medicine, radiology, medicine, and surgery.
In particular, there have been many technical
advances in the surgical management of
primary hyperparathyroidism (HPT) and with
these advances have come the issues and
controversies…….
3. A FEW FACTS TO APPRECIATE
There are 4 parathyroid glands, lie on the
posterior surface of the thyroid.
The superior glands are located on the poster
medial aspect of the thyroid near the
tracheoesophageal groove.
The inferior parathyroids are more widely
distributed in the region below the inferior
thyroid artery .
Common sites for ectopic parathyroids are
thyrothymic ligament, superior thyroid
poles, tracheoesophageal
groove, retroesophageal space, carotid sheath
4. A FEW MORE FACTS….
The average weight of a normal PTH gland is
35 to 40 mg; in adults, its color turns to
yellow as the fat content increases.
The inferior PTH originate from the 3rd
branchial pouch, whereas the superior
parathyroids descend from the 4th branchial
pouch.
The superior and inferior parathyroid glands
receive their blood supply from the inferior
thyroid artery in 80% of cases.
5. SOME MORE FACTS TO REMEMBER..
Each parathyroid gland generally receives
a single end-artery blood supply that is
vulnerable to injury during surgical
manipulation.
The glands are made up of chief and
oxyphil cells, as well as fibrovascular
stroma and adipose tissue.
7. 3 PATHOLOGIC LESIONS LEADING TO PRIMARY
PTH
1, PARATHYROID
ADENOMA
2. PARATHYROID
HYPERPALSIA
3. PARATHYROID
CARCINOMA
8. 3 PATHOLOGIC LESIONS LEADING TO PRIMARY
PTH CONTINUED
1.PARATHYROID ADENOMA-benign encapsulated
neoplasm- responsible for 80-90% cases.
2.PTH HYPERPLASIA –proliferation of
parenchymal cells –affects all parathyroid
glands-responsible for 10-15% cases.-
multigland hyperplasia have sporadic disease.
also associated with multiple endocrine
neoplasia(MEN)
type 1 (primary HPT combined with lesions of the
pancreas and pituitary)
type 2A (primary HPT, medullary thyroid
cancer, and pheochromocytoma) syndromes.
PTH HYPERPLASIA is not a part of Type 2B –but includes
9. 3 PATHOLOGIC LESIONS LEADING TO PRIMARY
PTH CONTINUED……
3.PARATHYROID CARCINOMA - a slow-
growing, invasive neoplasm of parenchymal cells
responsible < 1% of cases of primary HPT.
Although fibrosis and mitotic activity are
common, they are not specific for malignancy.
For diagnosis of carcinoma invasion of blood
vessels, perineural spaces, soft tissues, thyroid
gland, or other adjacent structures, or tumors
with documented metastases are must.
It is often difficult for the pathologist to make this
diagnosis, especially if there is only a frozen
section analysis of a resected parathyroid gland.
10. Secondary Hyperparathyroidism-
the pathogenesis of secondary HPT has
multiple contributing factors, like genetic
mutations, altered vitamin D metabolism and
resistance, impaired calcemic response to
PTH, retention of phosphorus, and altered
metabolism of PTH.
In all cases of secondary HPT, the failing
kidney is unable to hydroxylate vitamin D2
to active vitamin D3 (calcitriol)
ROLE OF PARATHYROIDECTOMY IN SECONDARY
HYPERPARATHYROIDISM
11. ROLE OF PTH SURGERY IN SECONDARY HPT
Although secondary HPT is typically
managed initially with non operative
strategies, there are pathophysiologic
sequelae of chronic renal failure that
serve as indications for
parathyroidectomy.
post parathyroidectomy patients have
shown improvement in physical activity
and increase in muscle force
measurements and also improvements in
anemia.
12. ROLE OF PARATHYROIDECTOMY IN TERTIARY
HYPERPARATHYROIDISM
TERTIARY.-
Tertiary HPT occurs in a subset of patients with
secondary HPT in whom the parathyroid glands
become autonomous and hypercalcemia
develops.
Can occur even post transplantation, when
secondary HPT persists.
13. ROLE OF PTH SURGERY IN TERTIARY HPT
CONTINUED
Surgical treatment of tertiary HPT is
reserved for patients without resolution of
symptoms, for those with hormonal and
chemical abnormalities such as elevated or
increasing iPTH(intact PTH) levels and an
increase in serum calcium levels to higher
than 12.0 mg/dL that persists more than 1
year after transplantation
for those with acute hypercalcemia (calcium
level >12.5 mg/dL) in the immediate post-
renal transplant period.
14. ROLE OF PARATHYROID SURGERY IN MEN-1
ASSOCIATED HYPERPLASIA
Parathyroid surgery in patients with MEN1 is
thought of as a debulking or palliative
procedure because recurrence is
inevitable, because it is indicated to treat and
prevent the complications of HPT.
The initial surgical procedure of choice in a
patient with MEN1 and HPT is subtotal
parathyroidectomy or total parathyroidectomy
with heterotopic auto transplantation of
resected parathyroid tissue; transcervical
thymectomy is also performed at the initial
operation
15. ROLE OF PARATHYROID SURGERY IN MEN-2A
When compared with HPT in MEN1, HPT in
MEN2A tends to be milder and more often
asymptomatic because of a single
adenoma, although multiglandular hyperplasia
does occur. Therefore, curative resection can be
less aggressive.
Enlarged parathyroids encountered during
thyroidectomy for medullary thyroid cancer in a
normocalcemic patient are resected.
Most, but not all endocrine surgeons leave
normal appearing parathyroids in situ, although
total parathyroidectomy with auto transplantation
to the forearm has been advocated by some.
16. WHAT ARE THE ISSUES IN PARATHYROID
SURGERY?
Controversy regarding patient selection.
Controversy regarding if surgery is
providing a substantial benefit.
Controversy regarding the need for pre-
op localization.
Controversy regarding the superiority of
intra-operative localization over pre-
operative localization.
17. PATIENT SELECTION- WHO REALLY NEEDS IT?
Even though a National institutes of
health consensus conference was held in
1990, another workshop in 2002 and the
latest one in 2008,there is still no
consensus among endocrinologist and
endocrine surgeons about whether to
administer non-operative medical therapy
and monitor or to refer them for early
parathyroidectomy.
However, because of long term
deleterious effects of bone
mineralization, the pendulum has shifted
to surgical intervention.
18. CRITERIA FOR SURGICAL REFERRAL
Criteria for surgery has been established according
to the best evidence to date……
Serum calcium concentration >1 mg/dl above
upper limits of normal.
Bone density at lumbar spine, hip, or distal end of
radius that is > 2SD below peak bone mass
(T- score<-2.5)
All individuals with primary hyperparathyroidism
and <50yr
Patients for whom medical surveillance is
undesirable or impossible.
19. IS THERE A SUBSTANTIAL BENEFIT OF
PARATHYROIDECTOMY?
Good response to parathyroidectomy has been shown in
following:
1.Neuromuscular symptoms of primary PTH
Proximal muscle weakness
Respiratory muscle capacity.
2.Psychiatric symptoms
Mental dullness
Confusion
Depression.
3.Significant and durable increase in bone mineral density in
the lumbar spine and hip apparent within 6 months of
surgery.
4.Urinary ca excretion and nephrolithiasis reduced by surgery
However No effect of successful surgery noted on HTN or renal
impairment.
20. PRE-OP LOCALIZATION-REALLY NEEDED?
Dopmann, a radiologist…once said
“only localization test necessary was to locate a
good endocrine surgeon” but this maxim has been
proved outdated as image –guided targeted
approach has reduced morbidity in a big way.
There has been a paradigm shift in use of
preoperative imaging in primary
hyperparathyroidism
Major advances in imaging studies has led to
development of more localized surgery, with the
opportunity for shorter operation times, the use
of local or regional anesthesia, and limited or no
hospital stay.
22. Physiologic areas of increased tracer
uptake include the thyroid, salivary
glands, heart and liver
SESTAMIBI SCAN DEMONSTRATING LEFT INFERIOR
PARATHYROID ADENOMA.
23. SESTAMIBI SCAN
1- works by mitochondrial uptake of 99mTc
sestamibi,and parathyroid cells typically have a
large number of mitochondria.
2- Sestamibi, a monovalent lipophilic cation, is
preferentially concentrated in adenomatous
and hyperplastic parathyroid tissue because of
increased blood supply, higher metabolic
activity, and absence of P-glycoprotein on the
cell membrane
.
24. SESTAMIBI SCAN CONTINUED….
3-Sestamibi imaging can be performed
preop. for Minimally Invasive
Parathyroidectomy planning , or in the
morning of surgery in the operating room
in conjunction with the use of a gamma
probe to guide the surgeon during
surgery
25. LIMITATIONS OF SESTAMIBI
false-positive results on sestamibi scans.
overcome in part by using the double-tracer
subtraction technique of sestamibi, in which
both thyroid and parathyroid nodular
abnormalities can be diagnosed
simultaneously, or in combination with neck
ultrasonography to distinguish thyroid
lesions and parathyroid adenomas
preoperatively.
Sestamibi scans are now being performed
with simultaneous CT imaging to yield
correlative functional and anatomic
27. 4D CT
4 dimensional CT , a novel imaging
modality similar to CT angiography, is
derived from 3 dimensional CT scanning
with added changes in perfusion of
contrast over time.
It generates detailed multi-planar images
of the neck and allows the visualization of
differences in perfusion characteristics of
hyper functioning parathyroid gland.
4D CT images provide anatomic and
29. ULTRASOUND IMAGE OF A HYPOECHOIC PARATHYROID ADENOMA
Ultrasound is effective, noninvasive, and inexpensive, but
its limitations include operator dependency and restriction
to application in the neck because it cannot image
mediastinal parathyroid lesions
30. ANGIOGRAM SHOWING THE ADENOMA AS A CLASSIC
BLUSH IN THE RIGHT POSTERIOR POSITION(ARROW)
31. ANGIOGRAPHY
Meant for patients who require re-exploration—
noninvasive localization studies will have
negative, discordant, or non-convincing results
This technique requires catheterization of multiple
veins in the neck and mediastinum, from which blood
samples are obtained.
Since results of PTH measurement performed in the
angiography suite are available quickly,interventional
radiologists can obtain additional samples from a
region in which a subtle, but potentially
significant, PTH gradient is detected.
32. ANGIOGRAPHY CONTINUED……
Because parathyroid adenomas have
increased vascularity, they have a
characteristic blush on arteriography.
This use of interventional radiology
rarely causes serious complications such
as visual field defects or other
cerebrovascular events, but such studies
are time-consuming and expensive .
33. USG GUIDED FINE NEEDLE ASPIRATION OF
SUSPICIOUS LESION
ultrasound localization can be used to guide
fine-needle aspiration of a lesion suspicious
for a parathyroid adenoma.
This technique can be used with rapid PTH
measurement of the parathyroid aspirate in
the ultrasound suite to give
ultrasonographers immediate feedback so
that they can continue searching for an
abnormal parathyroid gland if the aspirate of
the suspicious lesion is negative.
35. INTRAOPERATIVE PTH ASSAY
The rapid intraoperative PTH assay can be
used to confirm adequate removal of hyper
secreting parathyroid
A peripheral blood specimen is obtained
immediately before surgery.
Repeat blood samples are then drawn
intraoperatively immediately after resection
of the enlarged gland(s) to capture a
potential hormone spike caused by
manipulation of the gland during
extirpation, and then 5 and 10 minutes after
excision.
36. INTRAOPERATIVE PTH ASSAY
A 50% reduction in the PTH level from
baseline is used as an indication that the
exploration has been successful..
The rapid PTH assay is especially helpful
when the surgeon has difficulty
distinguishing between thyroid
tissue, lymph nodes, or a parathyroid
adenoma.
37. CONTROVERSY REGARDING INTRAOP PTH
MEASUREMENTS
false negative predictions from the test lead
to unnecessary exploration.
Cost factor
although there continues to be some
controversy, the largest endocrine surgery
centers use the assay as an important
adjunct to MIP.
In patients with multigland disease in
particular intraoperative PTH testing has
been shown to be essential
38. RADIOGUIDED PARATHYROIDECTOMY
Hand held Gamma
counter with a
probe
In radio guided
parathyroidectomy,10 to 20 mCi
of 99mTc-sestamibi is injected
IV 2 to 4 hours before
surgery, and the adenoma is
localized intraoperatively with a
hand-held quantitative gamma
counter with a 9- to 14-
mmprobe.
Gamma counts are obtained at
the start of the operation in all
four quadrants of the
neck, through the skin, and
after the incision, under the
strap muscles.
.
39. RADIOGUIDED PARATHYROIDECTOMY CONT.
Exploration in which counts are highest
focuses surgery and reduces operative time.
The activity of the removed parathyroid is
checked with the gamma probe to confirm
cure.
The excised adenoma emits radioactivity at
least 20% and often 50% in excess of the
post excision background.
Finally, the post excision radioactivity in all
four quadrants of the neck should equalize.
40. CONTROVERSY REGARDING RADIOGUIDED
PARATHYROIDECTOMY
gamma probe provides functional feedback to
the surgeon helping in intraoperative decision
making.
particularly helpful in the setting of false-
positive sestamibi scans, ectopic parathyroid
adenomas, and remedial parathyroidectomy in
which attempts at localization have been
suboptimal.
Still, intraoperative use of the gamma probe has
not been embraced by most experienced
endocrine surgeons because it yields little
additional information over that obtained by
41. PTH SURGERIES BROADLY CLASSIFIED INTO
TRADITIONAL AND MINIMALLY INVASIVE
Traditional
Bilateral neck exploration
General anesthesia
All parathyroid glands are
identified
Intraop frozen section
Patients admitted for 1-2
days
Minimally invasive
Unilateral neck
exploration
Regional or local
anesthesia
Excision of culprit gland
Preoperative localization
Ambulatory patient
42. MINIMALLY INVASIVE PARATHYROIDECTOMY
A focused exploration is performed according
to the results of the preoperative imaging
study, and the intraoperative PTH assay is used
to confirm the adequacy of resection in the
operating room.
MIP was associated with a 50% reduction in
operating time and 7fold reduction in length of
hospital stay which represents a reduction in
total hospital charges by almost 50%.
43. TECHNIQUE OF MINIMALLY INVASIVE
PARATHYROIDECTOMY
Unilateral neck exploration under local or
regional anesthesia
A, A small transverse cervical skin incision is
made, the platysma is divided, and the anterior
jugular veins are preserved.
B, The raphe between the strap muscles is
divided in the midline.
C, The parathyroid adenoma is excised, with
care taken to preserve the recurrent laryngeal
nerve and minimize manipulation of the tumor
during ligation of the end artery.
44. VIDEO-ASSISTED PARATHYROIDECTOMY
It does not require steady gas flow, but rather a
brief insufflation of carbon dioxide to establish
the operative space, which is then maintained
by external retraction.
Preoperative localization is essential and
general anesthesia is typically used, although
local anesthesia might be feasible.
A 15-mm skin incision is created 1 cm above
the sternal notch to accommodate tactile
assessment, suction irrigation, and dissection
and retraction equipment.
45. VIDEO ASSISTED PARATHYROIDECTOMY
CONTINUED……
Another 10-mm trocar site is made
vertically in the midline below the strap
muscles and above the thyroid gland on
the ipsilateral side of the suspected
adenoma to accommodate the insufflator
at the start of the case;
a 30-degree, 5-mm endoscope is then
inserted with two retractors for moving
the thyroid medially and the strap
muscles laterally.
46. ENDOSCOPIC PARATHYROIDECTOMY
Patients with mediastinal parathyroid
adenomas can undergo thoracoscopic removal.
Access for the endoscope is obtained at the
manubrium and two additional ports are
inserted laterally in the neck, anterior to the
sternocleidomastoid muscle and ipsilateral to
the parathyroid tumor
The operative space is created between the
platysma and strap muscles by using
insufflation at low pressure (5 to 8 mm Hg), and
the strap muscles and thyroid are mobilized to
expose the parathyroid
47. PROBLEMS WITH VIDEO ASSISTED
PARATHYROIDECTOMY
there is a significant learning curve
associated with endoscopic
parathyroidectomy.
Even with low insufflation pressure, there
can still be problems with small amounts
of blood obscuring the field of
view, metabolic disturbances from carbon
dioxide absorption, subcutaneous
emphysema.
the operative space can be lost during
suction
48. REMEDIAL PARATHYROIDECTOMY
Remedial parathyroidectomy is often
required for symptomatic persistent and
recurrent HPT.
Persistent HPT is defined by an inability
to achieve normalization of the serum
calcium level after initial exploration and
represents an immediate technical failure.
Recurrent disease is defined by initial
normalization of the serum calcium level
but then delayed hypercalcemia after 6
49. REMEDIAL PARATHYROIDECTOMY CONT.
Preoperative localization and use of the
rapid intraoperative PTH assay are
important adjuncts for enhancing success
rates during remedial parathyroid surgery.
Perhaps the best indication for 4D-CT is
in the setting of remedial neck surgery.
In cases of reexploration,it can be useful
to have cryopreservation available
because the only remaining parathyroid
tissue might be the site of persistent or
50. POSTOPERATIVE COMPLICATIONS
The rate of persistent HPT can be as high as
30% in less experienced hands.
Injury to the RLN or nerves, leading to
hoarseness or frank airway compromise if both
nerves are injured .
Superior laryngeal nerve injury results in
subtle voice changes, which can have profound
deleterious effects in professional singers or
speakers.
Intraoperative monitoring of the RLN using
specialized equipment allowing for recording
and documenting of electromyography signals
of vocal cord function have been introduced.
51. PARATHYROID ADENOMA WITH THE THYROID GLAND
ABOVE AND THE RECURRENT LARYNGEAL NERVE
SPLAYED AROUND IT (TIP OF THE FORCEP)
52. COMPLICATIONS CONTINUED……
Hematomas and wound infections are
uncommon. The risk for these
complications is theoretically less when
exploration is confined to one side of the
neck.
Hypoparathyroidism from injury to or
removal or devascularization of the
remaining parathyroids can occur and
result in hypocalcaemia.
53. CONTROVERSY REGARDING ASYSMPTOMATIC
HPT
The principal debate is whether patients should
be treated with early surgery or whether
surveillance or medical therapy can be used
safely until symptoms develop.
Patients with elevated PTH levels and
consistently normal serum calcium levels, in
whom secondary causes of
hyperparathyroidism have been excluded, may
represent the earliest presentation of primary
HPT.
It is believed that during this early
phase, termed normocalcemic
hyperparathyroidism, elevated serum PTH
54. CONTROVERSY REGARDING ASYMPTOMATIC
PTH
many of such patients had a history of
kidney stones (14%),fragility fractures
(11%), and osteoporosis (57%) over the
course of up to 8 years.
During follow-up, 40% developed further
signs of primary HPT, such as
hypercalcemia, renal stones, fractures, or
bone loss.
normocalcemic HPT can have substantial
skeletal involvement and may represent an
early form of symptomatic, rather than
asymptomatic, primary HPT.
55. CARRY HOME MESSAGE
Hyperparathyroidism is increasingly being
recognized as a result of the detection of
hypercalcemia by widespread use of multiphasic
screening.
symptoms in patients are subtle or absent.
Parathyroidectomy is a highly successful treatment
for some patients with asymptomatic primary
hyperparathyroidism may have a prolonged benign
course.
Significant and durable increase in bone mineral
density in the lumbar spine and hip apparent within 6
months of surgery.
Pre-operative as well intra-operative localization
have a role to play in successful surgery proving the
dictum wrong that only localization necessary is a
good endocrine surgeon .
57. THANK
YOU……..
Special thanks to Prof Dr SK Das Sir for giving
his precious time and moderating the
presentation and my Sir Dr S.S. Mohanty for
being a guiding force in everything that I am
able to do…….
