Transcript Comparative Study on the Long-Term Effectiveness between

Does the Elecitvie Transcervical Superior
Mediastinal LN Dissection (SMLND) Really
Necessary For Papillary Thyroid Carcinoma ?
– A Prospective Study
Seung Won Lee1, Chan Goo Lee1, Ji Oh Mok2,
Hyun Sook Hong3, Jeong Ja Kwak4,
1Dept.
of Otolaryngology-Head and Neck Surgery, Dept. of
Internal medicine, 2Division of Endocrinology, 3Dept. of Radiology,
4Dept. of Pathology, 5Dept. of Laboratory medicine and genetics,
SoonChunHyang University Hospital, Republic of Korea
Introduction
Superior Mediastinal LN (SMLN)

PTC commonly develop regional LN
metastasis and this is associated with an
increased risk of recurrence

There are consensus for CND of PTC from
the several decades of debates

SMLN - divided by the level VI by the
Imaginary line, not by anatomical Barrier

Para
Inferior portion of level VI-neigboring by the
Pre
pretracheal, paratracheal LN

The possibility of SMLN metastasis when
the neighboring LN metastasis presents
Para
SMLN
Introduction
Superior Mediastinal LN Metastasis

Role preoperative US imaging is limited for SMLN

Recurrences of SMLN, can be life-threatening owing to their
proximity to vital structure


Suggested mechanism SMLN metastasis

Follow the downward lymphatic drainage from the central LN

Direct extension into the SMLN
However, no guideline and consensus for the elective SMLND

The indications and extent of SMLND are not clearly defined
Introduction

Previous study: Small No, retrospective, high variability of positive
LN rates, mixed with CN(-) and CN(+) of SMLN
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5.4% (21/392) of PTC (A Machens Ann Surg Oncol 2009) : transsternal
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5.6% (4/57) of PTMC (JL Roh Annals of Surgery 2008) : transcervical
app
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9% (25/284)PTC (Block MA Am J Surg 1972 ) : transsternal app
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48.1% (10/21) of differentiated thyroid ca (A Sugeonya 1993 Surgery) :
transsternal app
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61.3 % (16/31) T4, poorly differentiated ca. (Y Duric 2009 Am J
Otolaryngol Head&Neck Surg) : transcervical

100% (30/30) CN(+) SMLN PTC (ML Khoo Head &Neck 2003) :
transcervical
Introduction
 Risk factors of SMLN metastasis of previous study

Contrallateral lat neck LN meta (A Sugeonya 1993 Surgery)

CLN meta (Y Duric 2009 Am J Otolaryngol Head&Neck Surg)
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Extensive CLN meta, direct extension to SMLN, contralat CLN
meta (ML Khoo Head &Neck 2003)

Reoperative MTC – PTE, cervical LN meta (A Machens Br J
Surg 2004)

Poorly differentiated Ca, Hurtle cell ca, distant metastasis
(AAJ Mailand Am J Otolaryngol 1997, A Machens Ann Surg
Oncol 2009)
Purpose
The aim of this study
1. To demonstrate the incidence rates and safety of
transcervical elective SMLND
2. To identify risk factors presenting the SMLN
metastasis
3. To clarify the surgical indications when the
SMLND is necessary
Materials and Methods





From Jan 2009 to Jan 2011
Soonchunhyang University Bucheon Hospital.
Preoperative CN0 of SMLN by preoperative imaging study
Over the 1cm sized, 217 patients of PTC including

Total thyroidectomy with CND + SMLND

MRND/ Revional surgery for Rec PTC
Exclusion criteria

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
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No retrieved LN
Inaccurate labeling of level VI, VII during ND
Undifferentiated cancer
Prospective clinical trials : SCHBC_ IRB_ 09_60
Materials and Methods

NO Tie – Harmonic Scalpel Thyroidectomy Techniques (Johnson
& Johnson Ethicon, USA)
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All SMLND were performed transcervically without sternotomy
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The boundaries of SMLND – LN behind the sternal manubrium

sternal notch superiorly, and the left brachiocephalic vein
and innominate artery, inferiorly

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Intraoperative labeling of level VI, VII LN using black No2-0
Following parameters was examined
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Demographic data
Total time of operation
Time of CND + SMLND
Amount of bleeding
Materials and Methods

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Pathology : Tumor size T stage, PTE, lymphovascular invasion,
LN metastasis status of level VI, VII

Complication : Vessel tearing, trachea, esophageal injury,
temporary and permanent hypoparathyroidism
Definition of Postoperative Hypoparathyroidism

Temporary hypoparathyroidism : the PTH level drop down below
10 IU/ml following thyroidectomy or hypoparathyroidism Sx (+)

Permanent hypoparathyroidism : Can not restore the PTH level
above 10 IU/ml until postop1 yr and persisent
hypoparathyroidism Sx

Stasticaly Analyses : Chi square test, fisher’s exact test, multiple
logistic regression test
Operative Techniques
Caudal
cephalad
Operative Techniques
Para
Pre
SMLN
Para
Results
Demographic data (N = 217)
Mean + SD
Female: male
Minimal Maximum
181 : 37
Age (yrs)
48.7 ± 13.1
(12 -81)
Tumor size (mm)
16.3 ± 0.9
(1.1 – 6.0)
T Stage
2.53 ± 0.4
(1 -4)
Total operating time (mins)
Time of CND +SMLND (mins)
Amounts of bleeding (ml)
109.8 ± 69.1
(40 – 780)
18.2 ± 4.3
(10 -30)
23.1 ± 14.1
(5 -100)
Results
LN data for Level VI, VII
Mean + SD
% of positive SMLND
15.7% (34/217)
No of Positive LN of SMLND
1.5 ± 2.1
Total No retrieved LN of CND
8.4 ± 6.6
No of positive LN of CND
1.7 ± 1.8
Results : univariate
Clinico-pathologic factors related to PTC with positive SMLN
metastasis
Variables
No. of pts with positive SMLN (%)
Size of tumor
Small /Large
25/182 (13.7%) / 7/32 (21.9%)
T Stage
Early/ Advanced
5/59 (8.5% )/ 29/158 (18.4%)
PTE
No/Yes
7/71 (9.9%) / 26/145 (17.9%)
P value
0.280
0.093
0.159
LV invasion
No/Yes
31/201 (15.4%) / 3/15 (20.0%)
Multifocality
No/ Yes
22/166 (13.3%) / 10/49 (20.4%)
Rev Surgery
No/ Yes
22/194 (11.3%) / 12/23 (52.2%)
0.711
0.253
0.000
Small tumor ≤ 2cm / large tumor > 2cm/ Early T stage : I, II / AdvancedT stage : III, IV /PTE :
perithyroidal extension (excluding microscopic PTE) * P < 0.05 Chi square test
Results : univariate II
Clinico-pathologic factors related to PTC with positive
SMLN metastasis
Variables
No. of pts with positive SMLN (%)
P value
Ipsilateral central pN (+)
No/ Yes
17/143 (11.9%) / 15/66 (22.7%)
Contralateral central pN(+)
No/ Yes
17/155 (11.0%) / 14/40 (35.0%)
Multiple central pN(+)
No/Yes
19/167 (11.4%) / 15/50 (30.0%)
Pretracheal central pN(+)
No/Yes
12/147 (8.2%) / 22/70 (31.4%)
Mutiple lateral pN(+)
No/Yes
17/180 (9.4%) / 17/37 (45.9%)
0.061
0.001
0.003
0.000
0.000
Results : multivariate
Multivariate logistic regression test for pathologic findings in relation to
PTC with positve SMLN Metastasis
Variables
ß (SE)
P value
Rev.Surgery
1.666 (0.659)
0.011
Mutiple lateral pN(+)
1.064 (0.532)
Pretracheal central pN(+)
Exp (ß)
95% CI Exp (ß)
Lower
Upper
5.290
1.454
19.250
0.045
2.899
1.022
8.222
1.293 (0.580)
0.026
3.644
1.169
11.360
Contralateral central pN(+)
0.834 (0.561)
0.137
2.302
0.766
6.918
Multiple central pN(+)
0.119 (0.652)
0.855
1.127
0.314
4.047
Rev Surg : Revisional surgery for recurrent PTC / SE : standard errror
Exp (ß) : exponential (ß) CI : confidence interval
Complications
Caudal

No major adverse effects – No major vessel injury,
pneumothorax, trachea, esophageal injury
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Minor complications
 Transient hypoparathyroidism : 31.8% (69/217)
 Permanent hypoparathyroidism : 3.6% (8/217)
 Tearing of the brachicephalic vein branch : 0.9% (2/217)
Cephalad
Summary I

A elective transcervical SMLND may be safely
performed without sternotomy and morbidity

SMLN metastasis were present 15.7% (34/217) of
clinically N0 SMLN region
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Univariate analysis showed that the rate of SMLN
metastasis was significantly higher in patients with
multiple lat. LN , pretracheal, contralat. central LN
metastasis, multiple central LN metastasis and
revisional cases for recurrent PTC patients (P < 0.05)
Summary II

Multivariate analysis showed that the pretracheal central LN,
multiple lateral LN meta, revision cases for level VI recurrent
PTC patients were the risk factor the SMLN mestasis (P < 0.05)

The elective transcervical SMLND is not necessary for the
routine thyroidectomy procedures

The elective transcervical SMLND is recommended for patients
with pretracheal central LN, mutiple lat. LN metastasis and
revisional surgery for level VI cases although SMLN is cN0
by preoperative imaging study

Long term follow up is necessary to evaluate the impact of
SMLND on the locoregional control and disease free survival
8th EACP at Jeju Island Nov 30th - Dec 1st 2012
Thank you for your attention