1. Thymectomy for Myasthenia Gravis? YES!
Richard J. Barohn, MD
Chair, Department of Neurology
Gertrude and Dewey Ziegler Professor of Neurology
University Distinguished Professor
Vice Chancellor for Research
University of Kansas Medical Center
Kansas City, KS

2. Thymectomy Rx for MG Perlo, et al 1971
Thymectomy – 267 pts
Complete remission – 34%
Improvement – 41%
Non-thymectomy – 417 pts
Complete remission – 17%
Improvement – 11%
Time to remission in thymectomy pts
25% 1st yr
40% 2nd yr
55% 3rd yr

3. A Treatment Carol: Thymectomy Revisited
Michael P. McQuillen, M.D. and Mary G. Leone, M.D. Neurology 1977; 12:1103 – 1106.

5. Thymectomy Practice Parameter Gronseth and Barohn, Neurology 2000
27 Class II studies
non-random, non-prospective
Surg vs. no-surg
RESULTS: THY pts more likely to do better
RR med free rem 2.1 higher for THY
RR asymp 1.6 higher for THY
RR imp 1.7 higher for THY
PROB: confounding variables:
THYM pts younger, female, more severe
non-random and non-std outcomes
REC – RC trial

6. Randomized Blinded Trial of Thymectomy for MG
Newsom-Davis, Wolfe, Cutter, Kaminski, Jaretski
Randomized/controlled NIH trial
REQ – gen, AChR Ab+
All pts go on prednisone
All get transternal thymectomy
Blinded evaluations
OUTCOME: Pred dose and QMG at 3 yrs
QUESTION: Do THY pts do better than pred alone?
Difficult/slow enrollment but enrollment complete (# 126 patients)
Most subjects outside USA
Wolfe G, et al. NEJM 2016;375:

8. Wolfe et al. Thymectomy in MG
(New England Journal of Medicine 2016;375: )
OMG Score (Mean±SE) by Treatment Group
QMG difference: 2.85 pts (99.5% CI ; p<0.001)
Time-Weighted Average AD Prednisone Dose (Mean±SE) by Treatment Group
Prednisone dose difference: 44 mg vs 60 mg (95% CI 7-25 mg; p<0.001)

9. Secondary Analyses: Wolfe et al. NEJM 2016;375:511-522
Treatment Group
Mean±SD or no./N (%)
Estimated
Difference
(95% CI)
P Value
Prednisone
Alone
Thymectomy
+prednisone
Time-weighted average prescribed AD prednisone dose (mg)a
59.3 ± 28.4
(N=56)
43.4 ± 23.1
(N=62)
16.0 ( )
0.001
Penalized time-weighted average AD prednisone dose (mg; max dose)a,b
72.9 ± 37.4
46.7 ± 24.9
(N=61)
26.3 ( )
< 0.001
Penalized time-weighted AD average prednisone dose (mg; dose at start)a,c
68.1 ± 38.3
45.6 ± 24.3
22.5 ( )
Time-weighted average MG
Activities of Daily Livinga,d
3.41 ± 2.58
(N=55)
2.24 ± 2.09
1.17 ( )
0.008
MG ADL at month 12
3.33 ± 3.40 (N=54)
1.92 ± 2.73 (N=61)
1.42 ( )
0.01
MG ADL at month 24
3.11 ± 2.93 (N=53)
2.02 ± 2.78 (N=59)
1.10 ( )
0.04
MG ADL at month 36
2.69 ± 2.80 (N=51)
2.14 ± 2.92 (N=59)
0.55 ( )
0.32
Azathioprine usee
28/58 (48)
11/65 (17)
31.4% (15.6%,47.1%)
Plasma exchange usee
9/58 (16)
10/65 (15)
0.1% (-12.7%,12.9%) ~1
Intravenous immunoglobulin usee
23/58 (40)
22.7% (7%,38.3%)
0.005
Minimal Manifestation Statuse
at month 12f
20/54 (37)
41/61 (67)
30.2% (12.7%-47.6%)
at month 24f
20/53 (38)
39/59 (66)
28.4% (10.6%-46.2%)
0.003
at month 36f
24/51 (47)
39/58 (67)
20.2% (1.9%-38.5%)
0.03
Hospitalization for MG exacerbation
Months 0-24: # of patientsg
17/60 (28)
6/66 (9)
19.2% (5.9%, 32.6%)
0.006
Cumulative daysh
26.4 ± 28.9
5.5 ± 2.9
0.004
Months 0-36: # of patientsg
22/60 (37)
27.6% (13.6%, 41.6%)
<0.001
22.5± 27.1
8.7 ± 7.7
0.21
Method 1 = maximum dose
Method 2 = Last dose prior to initiation of Prednison

10. Thymectomy for MG Now a Controlled Trials Exists! Positive study!
SUMMARY
Now a Controlled Trials Exists! Positive study!
But Response May Not be Immediate
Measured in Months to Years
No Guarantee of Improvement
Numerous Procedures
Thymoma is an absolute indication
Not rec for:
Ocular
Very young children
Greater than 60, or, ? > 70, or ? > 80
(Depends on how old the Rx Neurologist is)
TYPE
YEAR
Sternal Splitting
Early 1900’s
Maximally Invasive
1980’s
Transcervical
1988
Video-Assisted Thoracoscopic Surgery
Late 90’s
Robotics (DaVinci)
Early 2000’s