Download minimal access surgery for benign thyroid diseases

MINIMAL ACCESS SURGERY FOR
BENIGN THYROID DISEASES
Dr Ansari Sana Afreen
PG 2nd yr
Department of General Surgery
ANATOMY OF THYROID GLAND
The thyroid gland has
ØTWO LOBES that are located adjacent to the thyroid
cartilage.
ØLobes are connected in the midline by an ISTHMUS
that is located just inferior to the cricoid cartilage.
ØThyroid Gland extends to the carotid sheaths and
sternocleidomastoid muscles laterally.
ØThyroid gland: Level C5,6,7 & T1 Vertebra.
ØIsthmus : 2nd & 3rd Trachea Rings.
Coverings:
SKIN
PLATYSMA
STRAP MUSCLES
PRETRACHEAL
FASCIA
STRAP MUSCLES: (innervated by- Ansa cervicalis)
1. Sternohyoid
2. Sternothyroid
3. Superior belly of Omhyoid
Pyramidal Lobe:
Normally the thyroglossal duct atrophies,
In about 20-50% of individuals, the distal
end that connects to the thyroid persists
as Pyramidal Lobe.
Tubercle of Zuckerkandl:
It is the most posterior extent of the
thyroid lobe.
It is related to distal course of the RLN.
• Berrys Ligament: The thyroid capsule is condensed into the Berry's ligament
near the cricoid cartilage and upper tracheal rings.
The RLN is most vulnerable to injury in the vicinity of the
ligament of Berry.(25% of patients)
RECURRENT LARYNGEAL NERVE
The nerve often passes through this structure
along with small crossing arterial and venous
branches (Fig).
Any bleeding in this area should be controlled with
gentle pressure before carefully identifying the
vessel and ligating it.
BLOOD SUPPLY:
Each Thyroid Lobe is supplied by:
• Superior Thyroid Artery -First Branch of External Carotid Artery.
• Inferior Thyroid Artery -from Thyrocervical Trunk of Subclavian Artery.
• Thyroid Ima Artery
-from Aorta or Innominte 1-4%
The inferior thyroid artery crosses the recurrent laryngeal nerve (RLN),
necessitating identification of the RLN before it can be ligated.
Venous Drainage is by:
• Superior Thyroid Vein- drains into Internal Jugular vein.
• Middle Thyroid Vein- drains into Internal Jugular vein.
• Inferior Thyroid Vein- drains into Left Brachiocephalic Vein.
BLOOD SUPPLY
OF
THYROID GLAND
LYMPHATIC DRAINAGE:
Intraglandular lymphatic vessels connect both thyroid lobes through the isthmus.
Lymphatics drain to Regional lymph nodes• (LEVEL-6)- Pre-Tracheal and Pre-Laryngeal Lymphnodes -Delphic Nodes
• (Level 7)- downwards into the Superior Mediastinum.
• (LEVEL-2,3,4 & 5)- Deep Cervical Nodes- upper, middle, and lower jugular chain nodes & posterior Triangle Nodes
• others- retropharyngeal, esophageal
NERVE SUPPLY
NERVE
ORIGIN
MOTOR
SENSORY
INJURY
RECURRENT
LARYNGEAL NERVE
VAGUS
All Intrinsic muscles of Larynx
except Cricothyroid
To larynx below vocal U/L: Hoarseness of
cords.
Voice,Ineffective Cough
B/L: Airway Obstruction &
stridor Emergency
Tracheostomy
SUPERIOR LARYNGEAL
NERVE
VAGUS
a)External Laryngeal N
SLN
b)Internal Laryngeal N
SLN
Cricothyroid (tensor of vocal
cords)
Loss of Pitch of Voice.
To Supraglottic
Larynx
NERVE INJURY :
Ø RECURRENT LARYNGEAL NERVE:
• Injury to the RLN may occur by severance, ligation,
or traction (1%)
• It lies in Tracheo-esophageal Groove in relation to
Berrys ligament.
• Rt RLN courses more obliquely than Lt RLN
• The RLN is most vulnerable to injury during the last
2 to 3 cm of its course
• It can be damaged if the surgeon is not alert to
anomalies like Non-recurrent nerve, particularly right side (0.5-1%).
Ø EXTERNAL LARYNGEAL NERVE:
• Risk of injury to the - 20%
• especially if superior pole vessels are ligated en
masse.
RLN hooks around
• ligamentum arteriosum on the left with arch of aorta, and
• Right subclavian artery on the right side.
It runs in the tracheo-oesophageal groove near the posteromedial
surface close to thyroid gland.
RELATIONSHIP OF
RLN & INFERIOR
THYROID ARTERY
Along their course in the neck, the RLNs
may branch & pass
• Anterior,
• Posterior, Or
• Interdigitate
with branches of the Inferior
Thyroid Artery
Inferior thyroid artery may be absent in
1-3% cases.
Relationship of the External Laryngeal Nerve And Superior Thyroid Artery originally
described by Cernea and colleagues.
Type 1- the nerve crosses the artery
=1 cm above the superior aspect of
the thyroid lobe.
Type 2,
ØType 2a- the nerve crosses the
artery <1 cm above the thyroid
pole
ØType 2b- it crosses <1cm below it.
This space in front of cricothyroid is called as cricothyroid SPACE OF REEVES.
In this space external laryngeal nerve which is just proximal to superior pole deviates towards cricothyroid muscle.
The superior pole vessels should not be ligated en masse, but should be individually
divided, low on the thyroid gland
Steps followed in conventional thyroid surgeries,
ØLigation of superior pole vessels:
• the superior pole vessels are individually identified, ligated and divided low on the
thyroid gland to avoid injury to the external branch of the superior laryngeal nerve
ØLigation of inferior pole vessels:
• The inferior thyroid vessels are dissected, ligated, and divided as close to the
surface of the thyroid gland as possible to minimize devascularization of the
parathyroids (extra capsular dissection) & injury to the RLN.
The goal for the surgeon is ü to remove the whole gland or its specific part,
ü preserving inferior and superior laryngeal nerves and Parathyroid glands,
ü achieving safe hemostasis mainly by ligating superior and inferior
thyroid arteries.
The parathyroids usually can be identified within 1 cm of the crossing of the inferior thyroid artery
and the RLN, although they also may be ectopic in location
SUPERIOR
PARATHYROID
INFERIOR
PARATHYROID
• Father of thyroid surgery
• Nobel prize in physiology or medicine
(1909) for work on Thyroid.
Emil theodor kocher (1841-1917)
Swiss surgeon
• Kocher's test
Kocher's vein
Kocher's incision
Kocher’s Forceps
Kocherisation
Kocher's method of reduction of
dislocation of shoulder
HISTORY OF MINIMAL ACCESS SURGERY FOR THYROID
q Thyroid surgery has evolved considerably from the times of Billroth and Kocher.
q Kocher, in 1909, pioneered what is today known as the Conventional Thyroidectomy. It has remained the standard
approach to the thyroid gland and is still the most widely used technique world-wide.
q A recent advance is Minimal Access Thyroid Surgery (MITS).
q The first completely endoscopic thyroidectomy was performed by
Huscher et al. in 1997.
q Since Gagner et al. (2001) reported an endoscopic approach to the
parathyroid glands, various techniques have been described and
popularised for thyroid surgery as well.
q Minimally invasive video assisted thyroidectomy(MIVAT) was
introduced by Miccoli et al.
q Ferzli et al first reported MINET with 2.5 cm. cervical incision, using
head light for visualization.
Minimally invasive non-endoscopic thyroidectomy (MINET) is also known as Small Incision Thyroidetomy and do not require
specialized instruments like endoscopes and video- assistance.
RECENT ADVANCES:
The introduction of new technologies during the late 20th century,
such as Intra-Operative Neuro-monitoring & Harmonic Scalpel
can be considered as innovative aspects that improved safety in
thyroid resection with mortality rates
Types of Minimal Access Surgery for Thyroid
MINIMALLY
INVASIVE
THYROIDECTOMY
MIVAT
1.5cm Skin crease incision
MINI OPEN
THYROIDECTOMY
COMPLETE ENDOSCOPIC
THYROIDECTOMY
With CO2 insufflation
5mm 30 Endoscopes
MINIMALLY INVASIVE
VIDEO ASSISTED
THYROIDECTOMY
Remote Access Surgery for Thyroid
CO2 Gas Insufflation
Pressure – 4mm of Hg
2000
30mm skin incision
2011.
postauricular incision.
2010 sublingual
incision
12mm incision
HYBRID APPROACHES
2003
2007
BILATERAL AXILLO-BREAST APPROACH
Indications:
Thyroid Nodules within specific size limits and for low stage papillary carcinoma of the thyroid (PCT)
The most widely accepted criteria:
Ø A thyroid nodule size less than or equal to 30 mm in diameter
Ø Stage T1 or small T2 PCT
Ø Total thyroid volume less than 30 mL
Ø No history of thyroiditis or neck radiation
Recent studies have demonstrated that MIVAT can be safely used with patients who have histories of
prior thyroiditis,
Prior MIVAT, and
a thyroid volume up to 50mL
The following are causes of thyroid nodules:
Benign causes
Multinodular goiter (MNG)
Hashimoto thyroiditis
Thyroid cyst
Follicular adenoma
Subacute thyroiditis
After FNAC, the majority of nodules can be
categorized into the following groups:
Benign (65%),
Suspicious (20%),
Malignant (5%),
Nondiagnostic (10%)  repeat FNAC
Benign lesions : cysts and colloid nodules.
Risk of malignancy  <3%.
Suspicious cytology: follicular or Hrthle cell
neoplasms
Risk of malignancy  20%
Here diagnosis of malignancy capsular or
vascular invasion, that cannot be determined via
FNAB.
• Preoperative IDL to examine movement
of Vocal cords.
• ANAESTHESIA: General anaesthesia
• POSITION: supine, with a sandbag
between the scapulae.
The head is placed on a donut
cushion and the neck is extended to
provide maximal exposure.
Conventional thyroidectomy
•
•
•
•
•
•
Mini Open Thyroidectomy
•
•
•
•
•
•
• Upper pole - mobilized inferiorly & laterally ligate
superior pole vessels individually
Transverse Incision Lateral / Central
Incision length: 1.5-2.5cm
Skin crease above isthmus/ over swelling (lateral/central)
Platysma is divided- but no flap creation
Deep Fascia division not needed.
Central incision: approach b/w strap muscles
Lateral incision: approach b/w Strap muscles & SCM
• Middle thyroid vein can be ligated if seen (present 0nly in
15%)
• Upper pole – pulled upsuperior vessels are ligated
individually ligated.
• RLN & Parathyroid identification.
• RLN & parathyroid identification
Kochers Incision-along skin crease
Incision length: 5-7cm
Skin crease, 1cm below cricoid cartilage
Subplatysmal flap creation.
Deep Fascia divided vertically
Strap muscles retracted laterally.
• Lobe is retracted medially- Middle Thyroid Vein
ligated 1st.
• Lower pole is mobilised by gently sweeping all
tissues dorsally.
• Inferior thyroid vessels ligated and divided close to
Thyroid Gland.
• Divide Berrys ligament & separate thyroid gland
from trachea by sharp dissection.
• Space is created over surface of gland with fingers
towards lower pole, slip finger behind lower pole,
do gentle dissection.
• Same procedure for Inferior Thyroid vessels and RLN.
• Same procedure followed by gentle retraction of wound
& specimen
BENEFITS
Mini Open Thyroidectomy
• Both sides can be explored by
retraction or two separate
incisions.
• Easy to convert to total
thyroidectomy
• Most of the times drain not
necessary
• Short operative time
• Low cost
Conventional thyroidectomy
• Good exposure
• Ease of Lymphnode dissection
(if needed)
• Most of the times drain is kept.
• Easy to teach /learn
DRAWBACKS
• Difficult in obese
• Limited to thyroid lobes <7cm
size.
• Long incision
• Unneccesary B/L exploration
NO significant difference seen in number of complications encountered during both procedures
Conventional thyroidectomy
Mini Open Thyroidectomy
Advantages with MITS:
•
•
•
•
Reduced tissue trauma
shorter hospital stay
better cosmetic results
minimal postoperative pain
Disadvantages with ENDOSCOPIC THYROIDECTOMY:
• More invasive
• More operation time
MINIMALLY INVASIVE HEMITHYROIDECTOMY USING A MINI INCISION OVER THE
UPPER POLE OF THYROID SWELLING
Journal of Surgery
Volume 3, Issue 3, June 2015, Pages: 21-25
Authors :Dr. M. Subrahmanyam*, R. Sirisha, A. Deepthi, S. N. Mishra
Department of General surgery, Kamineni Institute of Medical Sciences, Narketpally
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Thyroid surgery using a mini-incision over the Upper Pole of the thyroid, as a new technique is presented here.
Methods: The study group comprised of 52 patients undergoing minimally invasive thyroid surgery by open method.
Time period: May 2005-May 2013.
Data regarding patient demographics, indication for surgery, operation performed, nodule size, final pathology, and
complications were recorded.
The operation was carried out through a 1.5-2-cm incision placed directly over the upper pole of the swelling.
Conclusion:
Minimally invasive thyroid surgery with a minimal incision over the upper
pole of thyroid swelling as an alternative to open thyroid surgery, using a
standard cervical collar incision, is safe and feasible.
It is easy to perform with a small learning curve.
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