Download Parathyroid carcinoma: Surgical Anatomy and Operative technique

Parathyroid carcinoma: Surgical
Anatomy and Operative technique
Dr R Botha
Moderator: Prof JHR Becker
Parathyroid carcinoma:
• The gold standard therapy of parathyroid cancer is
en bloc resection of the primary lesion:
 Parathyroidectomy
 Ipsilateral thyroid lobectomy
• Prophylactic neck dissection of the central
compartment.
• Modified radical neck dissection only if positive LN.
• Unfortunately the diagnosis is often only made
during or after surgery has been completed.
Central compartment LN dissection:
• Reported incidence of central LN metastasis
during initial treatment of parathyroid cancer
ranges from 8.1 – 17.9% in the literature.
• Due to the absence of alternative curative
approaches a systematic dissection of the
central LN compartment should be
recommended as part of the initial surgery in
all patients with suspected parathyroid cancer.
KM Schulte et al World J Surgery (2010) 34:2611-2620
Lateral compartment neck dissection:
• “ The indication for a lateral compartment
resection must be considered more critically.
In our opinion there is clearly no indication for
lateral neck dissection in parathyroid cancer in
the absence of demonstrable suspicious or
proven findings.”
KM Schulte et al World J Surgery (2010) 34:2611-2620
INCISION:
Skin incision:
• The incision is made through the skin,
subcutaneous tissue and platysma.
Superficial cervical fascia:
• Fatty connective tissue between the dermis
and the investing layer of deep cervical fascia.
• Contents: Cutaneous nerves, blood and
lymphatic vessels, superficial LN, platysma
(anterolateral) and variable amounts of fat.
EXPOSURE:
• Kelly clamps are placed onto the deep dermal
layer with vertical retraction of the flap with
countertraction with the surgeons’ finger to
expose a natural bloodless plane.
• A subplatysmal plane is created superiorly to
the uppermost aspect of thyroid cartilage and
inferiorly to the level of the suprasternal notch
and clavicular heads.
• Avoid injury to the anterior jugular veins.
• Identify the SCM muscles.
Infrahyoid muscles:
• Separate the sternohyoid muscles in the
midline from thyroid cartilage to suprasternal
notch.
• Retract the sternohyoid and sternothyroid
muscles laterally and separate the infrahyoid
muscles from the underlying thyroid lobe
with blunt dissection.
MOBILIZATION:
• The thyroid lobe is mobilized from lateral to
medial.
• Middle thyroid vein is identified and divided
between clamps and tied with 3.0 silk sutures.
• This permits full medial rotation of the thyroid
lobe.
INSPECTION:
Parathyroid gland anatomy:
Parathyroid glands:
• 85% of parathyroid glands are found within
1cm of where the RLN crosses the inferior
thyroid artery.
• Superior parathyroid glands are located
posterior and inferior parathyroid glands are
located anterior to the RLN.
• Carefully inspect and palpate the thyroid,
parathyroid glands and posterior tissue for
abnormalities.
Operative findings of possible
parathyroid carcinoma:
• Lobulated firm to stony hard parathyroid mass.
• Parathyroid gland is surrounded by a dense fibrous
grayish white capsule.
• Capsule adheres to adjacent tissue making it difficult
to separate from surrounding structures.
• Infiltration of the adjacent thyroid, nerve, muscle or
esophagus.
• Cervical lymphadenopathy.
Shane; JCE & M Vol. 86(2):485-493
Frozen section:
• Frozen section is not helpful to distinguish between
benign and malignant disease.
• Excisional biopsy is not recommended due to the risk
of intraoperative seeding of tissue leading to
parathyromatosis.
• Surgeons do not recognize the presence of cancer in
as high as 25% of cases.
• Carcinoma of multiple glands has been documented
in three cases, emphasizing the importance of four
gland exploration at initial operation.
Sharretts et al. Seminars in Oncology 37(6) 580-590
EN BLOC DISSECTION:
Improve exposure:
• Elevate the superior flap in the subplatysmal
plane to the level of the hyoid bone.
• Divide the infrahyoid muscles as high as
possible to improve exposure and avoid injury
to branches of the ansa cervicalis.
• Excise a portion of the infrahyoid muscle with
the specimen, to ensure an adequate margin,
if the parathyroid mass invades or is tightly
adherent to the adjacent muscle.
• Avoid intraoperative rupture of the capsule
which increases the likelihood of seeding.
Superior pole:
• Pull superior pole anteriorly and inferiorly.
• Sweep areolar tissue away on lateral and medial side
of the superior pole.
• Isolate superior pole vessels, clamp and ligate.
• Avoid injury to external branch of the superior
laryngeal nerve.
Superior laryngeal nerve:
Cernea classification:
Inferior pole:
• Usually the inferior pole blood vessels must be
divided as close as possible to the thyroid to
prevent injuring the blood supply to the
parathyroid glands.
• When performing an en bloc dissection the
ipsilateral superior and inferior parathyroid
glands will be removed with the specimen.
Recurrent laryngeal nerve:
Recurrent laryngeal nerve:
Recurrent laryngeal nerve:
• The most consistent position of RLN is where
it enters the larynx on the posterolateral
aspect of the cricothyroid muscle at the level
of the cricoid cartilage.
• If associated scarring and inflammation
around the thyroid is present: identify nerve in
inferior aspect of neck.
• Sacrifice RLN if involvement with carcinoma.
Recurrent laryngeal nerve:
• Do not use electrocautery near the RLN as it
may arc and injure the nerve.
• Perform the dissection from the anterolateral
surface of the trachea, through Berry’s
ligament, carefully as this is the most common
site if injury to the RLN.
Isthmus:
• Create a plane between the isthmus and anterior
surface of the trachea.
• Divide isthmus on medial border of the contralateral
lobe between two Dandy clamps.
• Obtain haemostasis of the isthmus with a running
suture.
CENTRAL NECK LYMPHNODE
DISSECTION:
• Landmarks: Hyoid bone superiorly,
suprasternal notch inferiorly, carotid sheath
laterally with trachea medially.
• Remove all tracheoesophageal, paratracheal and
upper mediastinal lymph nodes in a systematic
manner.
• Expose entire length of RLN removing adjacent LN.
• Only remove RLN or superior laryngeal nerve if
involved.
HAEMOSTASIS:
• Irrigate operative field and obtain
haemostasis.
• Do not use electrocautery near the RLN.
• Be careful not to incooperate the RLN into a
tie.
• Always visualize the RLN before ligation of a
bleeding vessel.
• Drain
CLOSURE:
• Reapproximate the sternohyoid muscles with
interrupted sutures.
• Close platysma with absorbable 4.0 sutures.
• Closure of skin.
Role of LN dissection in diagnosis during
the early postoperative period:
• Re-exploration is indicated if:
Gross characteristics of lesion were typical of
parathyroid carcinoma
Pathology appears to be aggressive with
extensive vascular or capsular invasion or
The patient remains hypercalcaemic
Shane; JCE & M Vol. 86(2):485-493
Role of LN dissection in diagnosis
during the early postoperative period:
• Simple resection may be curative (no reexploration indicated) if:
Absence of above signs
Diagnosis is made on microscopic
characteristics
Carefully observe these patients with PTH and
serum calcium levels.
Shane; JCE & M Vol. 86(2):485-493
References:
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Clinical presentation, staging and long-term evolution of parathyroid cancer. Talat
et al. Ann Surg Oncol (2010) 17:2156-2174.
The influence of intraoperative parathyroid hormone monitoring on the surgical
management of hyperparathyroidism. Mandell et al. Arch Otolaryngol Head Neck
Surg Vol 127 July 2001.
Lymph Node involvement and surgical approach in parathyroid cancer. Schulte et
al. World journal of Surgery (2010) 34:2611 – 2620.
Parathyroid cancer. Sharretts et al. Seminars in oncology, Vol 37(6) Dec 2010, 580590.
Parathyroid carcinoma encountered after minimally invasive focused
parathyroidectomy may not require further radical surgery. O’Neill et al. Worl
Journal of Surgery (2011) 35:147-153.
Parathyroid carcinoma. Clinical review 122. Shane et al; The Journal of Clinical
Endocrinology and Metabolism Vol. 86(2):485- 493.
The surgical strategy and the molecular analysis of patients with parathyroid
cancer. Keisuke et al. World Journal of Surgery (2010) 34:2604 – 2610.