Joshua Sonett, MD

Professor of Surgery

Chief Section of Thoracic Surgery

Columbia University

New-York Presbyterian Hospital

Disclosure

Personal Bias

• Jaretzki Dictum: The less thymus left

behind the better…Tempered by potential

morbidity of Radicality

• Bilateral Thorascopic Thymectomy

• 90% Dissection via left thoracoscopy

• +/- Cervical

MGFA Thymectomy Classification

T-1 Transcervical Thymectomy

a- Basic

b- Extended

c- Extended with Partial Sternal Split

d- Extended with Videoscopic Technology

T-2 Videoscopic Thymectomy

a- Classic VATS (unilateral)

b- VATET (bilateral with neck dissection)

c- Videoscopic with Robotic Technology (unilateral)

d- Videoscopic with Robotic Technology (bilateral)

T-3 Transsternal Thymectomy

a- Standard

b- Extended

T-4 Transcervical and Transsternal Thymectomy

Operative Steps

Thoracoscopic

Thymectomy

3 5mm ports

CO2 Insulflation to 8-10mmhg

Flex Head for Cervical dissection

Cervical Incision as needed ((<5%)

Step

Pericardio-Dia.

Step 2

Sternal release

Step 3

Pericardial Dis.

Step 4

Left Phrenic

Step 5

I. Vein

Step 6

Cervical Dis.

Step 7

A-p window

Right Ph

17% 16% 20%

12%

18%

43%

49%

65% 67%

71% 74%

0%

10%

20%

30%

40%

50%

60%

70%

80%

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Thymectomy: VATS (%) 2001 ~ 2011

Ann Thorac Surg 2012;94974-82

Columbia Experience

Cervical (T-1a)

0

10

20

30

40

50

60

70

80

90

1 2 3 4 5 6 7 8 9 10

Rem

issi

on

s (%

)

Follow-up (years)

Cervical-Sternal (T-4)

VATET (T-2b)

Ext. Sternal (T-3b)

Ext. Cervical (T-1b)

Spontaneous (Children)

VATS (T-2a)

Thymectomy for M.G.- No Thymoma Remissions – Life Table Analysis

Seminars in Neurology 24:49-62, 2004

Joshua Sonett, MD

Professor of Surgery

Chief Section of Thoracic Surgery

Columbia University

New-York Presbyterian Hospital

Thoracoscopic Thymectomy in Myathenias Gravis

hopwood

Limits to the Radicality of Surgery

Follow-up (months)

10 20 30 40 50 60 70 80 90 100 110 120

Cervical-Sternal (T-4)

100

90

80

70

60

50

40

30

20

10

0

Rem

iss

ion

s (

%)

Thymectomy for MG - No Thymoma Reality of Surgical wall

Trans-cervical (T-1a)

Neurology 48(Suppl 5):S52-63, 1997

? Immunologic Adjuvant tx

Rituximib/Alemtuzumab

Thymectomy in Myathenias Gravis

• Extended Transsternal vs. Basic Transsternal

• Krakow , Poland, 1996-1999, 61 cons BTST/58 cons ExTST

• Zielinski et al. Ann Thorac Surg 2004:78:253-8.

Thymectomy in Myathenias Gravis

Estimated

Extent

of the

Thymic

Resections

Seminars in Neurology 24:49-62,

2004

Posterior

Division

Mediastinal

Pleura

A - Vagus Nerve

B - Phrenic Nerve

Open and Minimally Invasive

Thymectomy: Outcome Analysis of

263 Patients

Jeffrey Javidfar, J Jurrado, M Bacchetta, A Newmark, M LaVelle, F D'Ovidio, LA Gorenstein, ME Ginsburg, Joshua R. Sonett

Division of Cardiothoracic Surgery

Columbia University Medical Center, New York-Presbyterian Hospital

Disclosures: None

Thymectomy and VATS

Is there optimal surgical approach to Thymectomy?

Should Thymomas be resected minimally invasively?

Mediastinal Thymic Disbursement

Operative Approach for Minimally Invasive

Thymectomy • Bilateral VATS

• Identify and visualize entire phrenic nerve

– Facilitates more complete resection

• “Jeretzki” Thymectomy:

– Resect all thymic tissue and mediastinal fat

– Complete, radical excision with negative margins

– Take pericardium and/or phrenic nerve if needed

• “Touch-Free” policy: care is take to not violate thymoma capsule – Any violation would degrade curative

intent

Study Design

• Single-center, retrospective study

• 263 patients over 11 years

– 77 Minimally invasive thymectomy

– 186 Open thymectomy

• Three approaches

– Transsternal (N=186)

– Video Assisted Thoracoscopic Surgery (N=75)

– Robotic (N=2)

14%

31% 55%

Pre-Operative Minimally Invasive Diagnosis (n=77)

2%

47% 51%

Pre-Operative Open Diagnosis (n=186)

HYPERPARATHYROIDISM

MEDIASTINAL MASS

MYASTHENIA GRAVIS

Baseline Characteristics

Thymectomy

Minimally Invasive* Open* p-value

Sample Size (n=263) 77 186 0.36

Sex (Male) 24 69 0.89

(Female) 53 117

Age, years 46 (36-54) 52 (38-61) 0.02

BMI, kilogram/meter2 26.9 (23-29) 25.7 (23-30) 0.77

Comorbid Condition

Hypertension 20 53 0.68

Coronary Artery Disease 4 14 0.50

Diabetes 1 16 0.03

Hyperlipidemia 6 33 0.04

Atrial Fibrillation 1 6 0.38

COPD 0 8 0.07

Asthma 7 16 0.90

Autoimmune Disease 4 16 0.34

*Median Values with Interquartile Range Where Appropriate

Myasthenia Gravis

Characteristics

Myasthenia Gravis Foundation of America Preoperative Staging Thymectomy

Grade Frequency Percent Minimally Invasive Open p-value

p= 0.71

1 27 19.42 5 22

2a 49 35.25 14 35

2b 33 23.74 11 22

3a 6 4.32 2 4

3b 11 7.91 2 9

4 4 2.88 0 4

4b 1 0.72 1 0

5 8 5.76 2 6

MIT: Minimally Invasive Thymectomy; OT: Open Thymectomy

Temporal Distribution of

Surgical Technique

Results: All Patients

Thymectomy

Minimally Invasive Open p-value

ICU LOS, days 0 (0-1) 1 (0-2) <0.01

Hospital LOS, days 3 (3-4) 5 (4-7) <0.01

Estimated blood loss 20 mL (0-25) 100 mL (20-200) <0.01

Duration of Surgery 2 hrs 47 min (1:17-3:33) 2 hrs 24 min (1:44-3:09) 0.88

Complications 0.60

Vocal Cord Paralysis 1 0

Cardiac 2 11

Respiratory 3 9

Other 1 5

None 70 161

LOS: Length of Stay; ICU: Intensive Care Unit; mL: milliliters; hrs: hours

*Median Values with Interquartile Range Where Appropriate

Myasthenia Gravis Results

• Remission* from symptoms

– Incomplete data, representative sample

– Equal remission rate between MIT and OT: 64% (p=0.59)

• * Did not require any medications to treat Myasthenia Gravis symptoms

Suspicious Mediastinal Mass Pathology

Pathology Frequency Percent Thymectomy

Minimally Invasive Open

Dermoid Cyst 1 0.93 1 0

Ectopic tissue 4 3.70 3 1

Liposarcoma 1 0.93 0 1

Lymphoma 2 1.85 0 2

Metastatic 3 2.78 1 2

Teratoma 1 0.93 1 0

Pseudotumor 1 0.93 0 1

Thymic Remnant 2 1.85 1 1

Thymic Cyst 16 14.81 4 12

Thymic Carcinoma 6 5.56 1 5

Thymoma 71 65.74 9 62

Positive Margin 5 7.00# 0 5

Extended resection 39 55.00# 6 33

*Final Pathology # Percentage of thymoma subgroup

Ruckert J, Swierzy M, Ismail M

Comparison of robotic and nonrobotic thoracoscopic

thymectomy: A cohort study

JTCVS volume 141, Issue 3 2011 673-677

Thymectomy for Thymoma

Minimally Invasive * Open * p-value

Sample size (n=71) 9 62 0.5

Sex Male 3 28 0.64

Female 6 34

Age, years 47 (40-48) 58 (46-65) 0.10

BMI, kilograms/meter2 25.9 (24.9-26.9) 26 (23.5-30.1) 0.82

ICU LOS, days 0 (0-0) 1 (0-2) <0.01

Hospital LOS, days 4 (3-4) 5 (4-7) <0.01

Estimated blood loss 7.5 mL (0-17.5) 200 mL (20-250) <0.01

Duration of Surgery 3 hrs 46 min (3:33-4:53) 2 hrs 10 min (1:44-3:13) 0.03

Total mortality 0 9 0.59

Masaoka Stage 0.50

I 4 16

II 5 41

III 0 5

BMI: Body Mass Index; LOS: Length of Stay; ICU: Intensive Care Unit; mL: milliliters; hrs: hours; min: minutes

*Median Values with Interquartile Range Where Appropriate # Patients with a pathological diagnosis of thymoma

Results

14%

31% 55%

Pre-Operative Minimally Invasive Diagnosis (n=77)

2%

47% 51%

Pre-Operative Open Diagnosis (n=186)

HYPERPARATHYROIDISM

MEDIASTINAL MASS

MYASTHENIA GRAVIS

Thymoma Pathology and Margins

Thymectomy for Thymoma

Minimally Invasive * Open * p-value

Sample size (n=71) 9 62 0.5

Specimen Size 4.45 cm (3-6) 6.5 cm (4.3-8.5) 0.09

Involved Surgical Margins 0 5

Extended Resection (n=38) 0.11

Lung (n=8) 0 8

Pericardium (n=12) 4 8

Lung & pericardium (n=13) 3 10

Pleura (n=3) 0 3

Innominate Vein/ SVC (n=2) 0 2

Masaoka Stage 0.50

I 4 16

II 5 41

III 0 5

*Median Values with Interquartile Range Where Appropriate # Patients with a pathological diagnosis of thymoma

Conclusion

• Minimally Invasive Thymectomy

– Can be safely performed

– May have clinical advantages

• Equivalent Surgical Tenets

• Can be used in all indications, including thymoma

– Selective cases

– Long-term follow up necessary

New York-Presbyterian Hospital

Columbia Universtiy

Sharp Dissection

on Pericardium

Note Relation of

Nerves to Thymus

The Real Issues

• Is Complete Total thymectomy important?

– Does a more extensive resection improve

results?

• Are all Thymectomy approaches equal?

– Extent vs. Morbidity

Thymectomy in Myathenias Gravis

Prospective study of the role of

thymectomy in Myathenias Gravis

• Multi-Center, International, Single–Blind,

Randomized Study comparing thymectomy to no

hymectomy in Non-thymomatous MG patients

receiving prednisone.

• Accrual goal: 200. MGFA class II-IV, Ab +

• NIH supported

• John Newsome-Davis, MD Study chair Clinical

Coordinator.

Thymecotmy in Myathenias Gravis

• Gronseth et al., evidenced base review, 1953-1998

• 310 articles, 28 articles with 8490 patietns consistent with class II evidence

• Broadly favorable effect of surgery vs. no surgery, with remission rate of 2.1,

• Benefis ascribed to thymectomy blurred due to multiple confounding variables

“The benefits of thymectomy in MG remain unproven”

Right

Phrenic

nerve

release

Right Mammary

vein release

Release from

Left

Brachiocephalic

vein

Cervical neck

dissection

Anterior

Division

Mediastinal

Pleura

Surgical resection of persistent thymic Tissue

after intial Thymectomy

Author/series

Patients Original

Procedure

Pathologic

Thymus Found at

Resection

Myasthenia

Improvement

Henze A et al.

Masaoka A et al.

Miller RG et al.

Rosenberg M et al.

20

6

6

13

Transcervical

Transcervical

Tanscervical

3

Basic

Transternal

3

Transcervical

20/20

6/6

5/6

11/13

19/20

3/6

5/6

6/13

Extent of Thymic Tissue Recoverd

in Peri-thymic mediastinal fat tissue

Author/Series. Surgical

Approach

Extracapsular

Thymic tissue

Jaretzki et al.

Masaoka et al.

Zielinski et al.

Ashour

Scelsci et al.

Mineo et al.

Maximal

Extended

Extended

Extended

VATET

VATS

50 pts 98%

18 pts 72%

58 pts 56.0%

38 pts 39.5%

27 pts 37%

31 pts 32%