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21 Parathyroidectomy: Surgical Techniques
Fig. 21.13 Dissection in
tracheoesophageal grove
Fig. 21.14 The RLN
exposed and the large
parathyroid lesion exposed
299
Fig. 21.15 The soft tissue
is gently separated
300
Fig. 21.16 Dissection
continues
Fig. 21.17 A large
parathyroid lesion being
removed
C. G. Nair and R. Ramachandran
The parathyroid lesion is identied in the 1–2cm vicinity of the lower pole of
the thyroid lobe usually anterior to RLN.The lesion traditionally appears as a
brown colored soft vascular nodule. Instruments applied to the lesion may rupture it. Tumor tissues thrown off to soft tissue may lead to parathyromatosis
which is a rare intractable cause of recurrence. The neighboring soft tissue is
separated from the lesion rather than the lesion is separated from the soft tissue.
DeBakey forceps applied to a tuft of soft close to adenoma helps to steady the
lesion while dissection is continued (Figs.21.16, 21.17, 21.18, and 21.19).
The inferior gland is highly variable in position and may extend to the superior
mediastinum. Lesions placed below the level of innominate vessels may require
median sternotomy.
Occasionally the lesion is felt rm and adherent to neighboring soft tissue and
or to the thyroid gland. Preoperative clinical features such as palpable neck
21 Parathyroidectomy: Surgical Techniques
Fig. 21.18 Inspection of
the eld for bleeding
Fig. 21.19 Exposure of a
lesion inside the carotid
sheath.
301
Fig. 21.20 Parathyroid
lesion at the origin of
carotid artery right side
302
Fig. 21.21 Right inferior
parathyroid adherent to
thyroid gland
Fig. 21.22 Right
hemithyroidectomy with
adherent parathyroid lesion
C. G. Nair and R. Ramachandran
swelling, high disease severity indices, and operative features such as a rm or
hard adherent lesion favor diagnosis of carcinoma. The only effective treatment
of parathyroid carcinoma is wide excision. So wide excision with ipsilateral
thyroid lobe is recommended when PC is suspected (Figs.21.21 and 21.22).
12. Superior parathyroid gland is more constant in a position close to the posterior
border of the thyroid gland. But the recurrent laryngeal nerve is in a closer relationship with it. Lesions of superior glands dissect deep into the trachea-esophageal groove and maybe occasionally hidden. The recurrent laryngeal nerve is
closely followed towards its entry to the larynx and is safeguarded. The thyroid
lobe is rotated medially exposing the trachea-esophageal grove. The rst assistant on the opposite side holds the thyroid lobe but should be cautious to avoid
bleeding from the surface. The major source of blood supply is from the inferior
thyroid artery or the posterior anastomotic plexus. Careful dissection is necessary to avoid injury to the vascular plexus and troublesome bleeding. The terminal cervical portion of the recurrent laryngeal nerve is closely applied to
superior parathyroid lesions (Figs.21.23, 21.24, 21.25).
21 Parathyroidectomy: Surgical Techniques
Fig. 21.23 Superior
parathyroid adenoma close
to the superior pole of
thyroid
Fig. 21.24 Superior
parathyroid lesion
and RLN
303
Fig. 21.25 The superior
parathyroid adenoma
delivered from
tracheoesophageal grove
304
Fig. 21.26 Mediastinal
parathyroid removed by
sternotomy
Fig. 21.27 Total
parathyroidectomy with
cervical thymectomy
C. G. Nair and R. Ramachandran
13. Ectopic parathyroid adenomas are not infrequent. Mediastinum, carotid sheath
retropharyngeal location are frequent locations for ectopic adenoma (Figs.21.19
and 21.26).
14. When imaging fails to localize parathyroid lesion total neck exploration is the
procedure of choice (Fig.21.27). Systematic exposure of the normal position of
the parathyroid is essential. The unusual locations such as carotid sheath, retroesophageal areas, and nally mediastinum are explored. Intra-thyroid parathyroid lesions are usually identied by ultrasound.
15. The neck wound is closed without inserting a drain (Fig.21.28). The divided
strap muscles are approximated after ensuring hemostasis from the cut edges of
the muscles. The cut edges are better approximated using horizontal mattress
sutures using 3 “O” polylactic acid sutures.
21 Parathyroidectomy: Surgical Techniques
Fig. 21.28 The neck
incision closed without a
drain
305
21.2 Parathyroidectomy inPatients withMultiple Endocrine
Neoplasia Type-1
Total parathyroidectomy with cervical thymectomy or sub-total parathyroidectomy with cervical thymectomy is the surgical option for Multiple Endocrine
Neoplasia type-1. Bilateral neck exploration is mandatory. Prior imaging is not
always supportive since only the most active lesion is lighted up in Scintigraphy.
But preoperative and intra-operative ultrasounds are helpful to remove ectopic
parathyroid lesions. Tracheo-esophageal grove is dened by mobilizing the thyroid lobe. The middle thyroid vein may have to be ligated for proper exposure.
The recurrent laryngeal nerve is and traced down towards the mediastinum. The
inferior parathyroid is lesion is very commonly encountered at this position.
Traditionally all parathyroid glands are removed and a bit of relatively normallooking gland removed for frozen section biopsy. After conrmation, the residual
portion is minced and implanted in the non-dominant forearm muscle (preferably
in brachioradialis). An alternate approach is to preserve in situ part of the relatively normal-looking gland (subtotal parathyroidectomy) (Fig.21.29).
The thymus and inferior parathyroid glands share the embryological site of origin from the third pharyngeal pouch. The thymus occasionally harbors parathyroid
remnants which gain signicance in MEN. So cervical thymectomy is also performed along with parathyroidectomy. RLN is traced to the thoracic inlet on both
sides and vestigial remnants of the thymus are removed. The inferior thyroid veins
are secured carefully since cut ends may slip to the superior mediastinum causing
troublesome bleeding.
306
Fig. 21.29 Total neck
exploration for multiple
endocrine neoplasia
C. G. Nair and R. Ramachandran
21.3 Parathyroidectomy: Secondary Hyperparathyroidism
ofRenal Origin
Hyperparathyroidism of renal origin is seen in end-stage renal disease patients on
maintenance hemodialysis. Reversible changes in parathyroid glands, which are
known as secondary hyperparathyroidism, are treated conservatively with diet regulations and medications such as vitamin D analogs and calcimimetics [3].
Parathyroidectomy is required in about 15% of patients after 10 years and 38% of
patients after 20 years of ongoing dialysis therapy. Persistently elevated PTH values
>800pg/ml (>6 months) that remain nonresponsive to pharmacologic therapy are
generally accepted as a criterion for parathyroidectomy [3, 4]. Persistent hypercalcemia or hyperphosphatemia (corrected serum calcium >10.2mg/dl [>2.5mmol/L] or
phosphorus >5.5mg/dl [>1.8mmol/L]) despite patient compliance to diet and optimized medications is also considered indication for parathyroidectomy [5].
Four different approaches were reported for the surgical treatment of renal
HPT [6]:
1. subtotal PTX with bilateral cervical thymectomy (3.5 parathyroid gland resec-
tion; subtotal PTX)
2. total PTX (TPTX) with auto-transplantation and bilateral cervical thymectomy
(TPTX+AT)
3. TPTX without auto-transplantation and without thymectomy
4. TPTX without auto-transplantation and with bilateral cervical thymectomy
(TPTX+BCT)
The rst three procedures aim to maintain a long-standing residual production of
PTH, whereas the goal of the fourth option is the complete elimination of PTH production. However, most experts recommend subtotal PTX and TPTX + AT as standard procedures. Thymectomy is indicated in conditions like MEN-1 and secondary
hyperparathyroidism since the frequency of intrathymic parathyroid glands or parathyroid cells rests varies considerably between 14.8% and 45.3% [7].
21 Parathyroidectomy: Surgical Techniques
307
21.4 Tertiary Hyperparathyroidism
The secondary hyperparathyroidism is reversible and when the stimulus ceases to
exist reverts to normality or near normality. But a few progress to an irreversible
condition known as tertiary hyperparathyroidism. One or two glands become autonomous and are usually diagnosed after a renal transplant.
Tertiary hyperparathyroidism is an absolute indication for parathyroidectomy
and the procedure is similar to parathyroid adenoma.
21.4.1 Parathyroid Auto-transplantation
Auto-transplantation of parathyroid tissue is done following total parathyroidectomy. The genetic mutation in MEN-1 predisposes growth of implanted parathyroid tissue also and so an easily accessible location is preferred. The usual site for
auto-transplantation is brachioradialis muscle mass. After conrming parathyroid
tissue by frozen section biopsy, the remaining tissue is sliced into small pieces of
<1mm size. The muscle is exposed and using a 2cm incision in Langer’s line. The
deep fascia is opened muscle ber is split using blunt dissection. Five to six pieces
of parathyroid tissue is implanted in a single pouch and the deep fascia is closed
with 3-0 polyglactic acid sutures. Three or four pouches are made in a single
incision.
21.4.2 Intraoperative PTH Assay
Intraoperative PTH assay is a very valuable tool to assess the successful removal of
parathyroid lesions. But the usefulness in patients with MEN-1 is not established.
But authors observed 10min decline of serum PTH level below the lower limit of
reference ranges ensures completeness and indicates hypocalcemia during the postoperative period.
21.4.3 Intraoperative Localization
Most of the operation theatres are equipped with a facility for ultrasound scanners
and are used when exploration fails to identify the lesion.
A handheld gamma probe is an adjunct used usually when MIBI imaging indicates positive results but is not supported by ultrasound imaging (Fig.21.30). The
gamma probe is also helpful adenoma is suspected in an ectopic location (Fig.21.31).
21.4.4 Radio-guided Parathyroidectomy
The widely used radiotracer is TC99 MIBI which gets concentrated in both thyroid
and hyperfunctioning parathyroid glands. The washout from the thyroid gland is
308
a
C. G. Nair and R. Ramachandran
b
c
Fig. 21.30 The Gama probe used for intraoperative use
Fig. 21.31 Planning the
incision with the Gama
probe
d
quicker than parathyroid lesions and so 740Mbq of MIBI is given as intravenous
infusion 90–120min before the start of the procedure.
It is advisable to do an intraoperative PTH assay to ensure completeness of
removal of all hyperactive glands. The patient is anesthetized and positioned for a
routine procedure. The incision is planned based on-site showing maximum count
in the hand-held probe (Figs.21.32 and 21.33).
A two to three-cm incision is made and dissected to expose the thyroid gland and
proceed to mobilize the thyroid lobe. The probe is introduced to identify and locate
the lesion. The activity measured over the hyperactive parathyroid gland is higher
than thyroid and background activity. Targeted tissue demonstrates elevated count