Robotic-Assisted Thymectomy in Myasthenia Gravis

Iskander Al-Githmi, MD, FRCSC, FRCSC (Ts&CDs), FACS, FCCPDepartment of Surgery. Division of Cardiothoracic SurgeryKing Abdulaziz University Hospital

Objectives

General Robotic Considerations Anatomy of Thymus Robotic Technique Outcomes Myasthenia Gravis over view Our early experience of RATS

Da Vinci Robotic Surgical System

B

A

C

General Robotic Consideration

Provide a stable camera platform Three- dimensional imaging Simulate motions of surgeon’s wrist to overcome motion limitation of straight thoracoscopic instruments Offer the surgeon a comfortable, ergonomically operating position Magnified and computer enhanced video imaging provide superior exposure and visualization

General Robotic Consideration

Telecast the surgeon hand motions to the remote operating room ( telepresence)-- Transatlantic cholecystectomy (Marescaux) Telementoring of surgeons Why have surgeons failed to embrace minimal invasive cardiothoracic surgery?

Factors Influencing Decision

Anatomy

Pathology

patient

Technology

Balance of Outcomes

Dissection required

Propensity of complications

Reduction in organ reserve

Approach

Selection/ preparation

Complication avoidance

Anesthesia

Anatomy

Anatomy

Thymic Tissue Distribution

Jaretzki 3d , et al. Journal of Thoracic and Cardiovascular Surgery, Vol 95, 747-757, Copyright © 1988

Potential sites for ectopic thymic tissue

Ann Thorac Surg 2000;69:1537-41

Imaging

Surgical Approach

Robotic Thymectomy Technique

Robotic Thymectomy

Robotic Thymectomy

Mack M .J. etal; J Thorac Cardivasc Surg 1996;112:1352-1360

Robotic Thymectomy

Surgical therapy of MG necessitate a complete removal of all thymic and fatty tissues in the anterior mediastinum Is this achievable ? Which surgical approach?, So what! Balance between extent of resection, morbidity, patients acceptance and results

Goals

VATS Vs Open

M.-W. Lin et al Eur J CT Surgery 37 (2010) 7-12

VATS Vs Open

M.-W. Lin et al Eur J CT Surgery 37 (2010) 7-12

OR Time

Ann Thorac Surg 2008;85:7688-771

Blood Loss

Ann Thorac Surg 2008;85:7688-771

Hospital Stay (days)

Ann Thorac Surg 2008;85:7688-771

Myasthenia Improvement

Ann Thorac Surg 2008;85:7688-771

Myasthenia improvement

CHEST 2005;128:3454-3460

VATS Vs Open

Ann Thorac Surg 2009;87:385-391

Robotic Thymectomy Costs

Osserman Classifications

J Thorac Cardiovasc Surg 1996;112:1352-13560

De Filippi post operative classifications

J Thorac Cardiovasc Surg 1996;112:1352-13560

Our early experienceDesign:It is a prospective study of RATS for NTMG in KAUH. Data were collected from medical records & supplemented with telephone survey

Methods: Jan 2008- Oct 2010 Patients (n) = 8Gender : Female = 8 Male= 0Mean age = 28 yr (16-46) All with non thymomatous Masthenia Gravis Left side (3 ports) robotic thymectomies (Da Vinci system)

Our early experience

Results: Complete stable remission = 25% Clinical improvement = 87.5% Mortality = 0 Left phrenic nerve injury ( n=1) No significant correlation between age and symptom duration (p=0.51) No significant correlation between pre-op CT scan and histopathology finding (p= 0.85)

Patient Characteristics

Mean age (Yr) 28 (16-46)

Mean symptom duration (month) 7.75 (3-12)

CT scan chest

• Hyperplasia • Normal

3 (37.5%)5 (62.5%)

Acetylcholine receptors Ab

• Positive• Negative

5 (62.5%)3 (37.5%)

Osserman stage

• Stage I• Stage IIa• Stage IIb• Stabe III• Stage IV

0 ( 0%)2 (25%)5 (37.5%)0 (0%)1 (12.5%)

Al-Githmi, Surgical Science J 2011;2:393-396

Pt. No Age

(y)

Osserman

classification

Symptoms

duration

(month)

Preop CT

chest

Histopathology Follow-up /De Filippi

Classification

6

months

12

months

18 months

1 16 IIb 12 Hyperplasia Thymic

involution

Class 4 Class 3 Class 2

2 19 IIb 3 Normal Normal Class 4 Class 2 Class 3

3 23 IIa 12 Normal Normal Class 4 Class 3 Class 3

4 26 IIb 12 Hyperplasia Normal Class 4 Class 4 Class 3

5 28 IIb 5 Hyperplasia Hyperplasia Class 3 Class 3 Class 2

6 30 IV 3 Normal Hyperplasia Class 3 Class 2 Class 1

7 36 IIb 7 Normal Hyperplasia Class 3 Class 3 Class 2

8 46 IIb 8 Normal Thymic

involution

Class 3 Class 2 Class 1

Selected preoperative variables and patient outcome

Post operative status after 12 months follow up

Class I N = 1 12.5%

Class II N = 3 37.5%

Class III N = 4 50%

Class IV N = 0 0%

Class V N = 0 0%

Post operative status after 18 months follow up

Class I N= 2 25%

Class II N = 3 37.5%

Class III N = 3 37.5%

Class IV N = 0 0%

Class V N = 0 0%

Class V N = 0 0%

Preoperative CT chest & Histopathology

Preoperative CT Chest Histopathology Positive diagnostic yield(%)

Normal ( n= 5) • Normal (n= 2)• Hyperplasia (n= 2)• Thymic involution (n = 1)

40

Hyperplasia (n= 3) • Normal (n=1)• Hyperplasia (n = 1)• Thymic involution (n = 1)

33.3

Our early experience

Conclusions: Robotic thymectomy is promising procedure, safe and effective Long-term results are comparable to conventional methods Global clinical improvement demonstrated in 87.5% after 12 months follow- up

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