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Myasthenia Gravis
Surgery, London

Thymectomy for myasthenia gravis is now supported by the strongest evidence in the history of this disease — a randomised controlled trial published in the New England Journal of Medicine in 2016. The question is no longer whether surgery works for the right patients. It is whether you are one of those patients — and whether the team managing you has the surgical experience, the specialist neurology partnership, and the perioperative infrastructure to do it safely.

Last reviewed: April 2026 · Dr Lawrence Okiror FRCS(CTh) FRCSEd(CTh) · GMC 6150382

What Is
Myasthenia Gravis?

Myasthenia gravis (MG) is an autoimmune disease in which the body’s immune system produces antibodies that attack the neuromuscular junction — the connection between nerves and muscles. The result is fluctuating skeletal muscle weakness that worsens with activity and improves with rest. In about two thirds of patients, the first symptoms involve the eyes (drooping eyelid, double vision); most go on to develop generalised disease affecting swallowing, speech, breathing, and limb strength.

The most common antibodies target the acetylcholine receptor (AChR), present in approximately 85% of patients with generalised MG. A smaller proportion (~5%) have antibodies to muscle-specific kinase (MuSK). This antibody distinction is clinically critical — it determines whether thymectomy is likely to benefit you. The thymus is directly involved in the immune dysfunction underlying AChR-positive MG, which is why removing it has a therapeutic effect.

About 70% of patients with generalised MG have thymic hyperplasia on histology. A further 10–15% have a thymoma. Thymoma-associated MG has its own specific pathway. See thymoma surgery page →

MGFA Clinical Classification

The MGFA (Myasthenia Gravis Foundation of America) classification is the current international standard, developed specifically to standardise thymectomy trials and MG research. It superseded the earlier Osserman classification, which your neurologist may have mentioned.

  • IOcular muscles only. Any degree of ocular weakness. All other muscle strength normal.
  • IIMild generalised weakness. IIa predominantly limb/axial; IIb predominantly bulbar/respiratory.
  • IIIModerate generalised weakness. IIIa predominantly limb/axial; IIIb predominantly bulbar/respiratory.
  • IVSevere generalised weakness. Same a/b subdivisions as above.
  • VIntubation required. Myasthenic crisis.

MGTX enrolled patients with MGFA Class II to IVb generalised MG. Ocular-only MG (Class I) was excluded.

Why the thymus matters in MG

The thymus is where T cells mature and where immune tolerance is established. In AChR-positive MG, the thymus contains myoid cells and epithelial cells expressing AChR subunits, as well as AChR-reactive B and T cells producing the very antibodies that attack the neuromuscular junction. Removing the thymus removes a major source of this ongoing immune drive — which is why thymectomy produces progressive neurological improvement, not an immediate switch-off of disease.

Seventy-Five Years of Practice —
Settled by One Trial

Thymectomy for myasthenia gravis was first performed in 1939. For seventy-five years it was practised without randomised trial evidence. That changed in 2016.

History · 1939–2015

Practice Before Evidence

Blalock 1939 · Harvey Cushing Award 1944 · Olanow series 1987 · Cumulative observational evidence

Alfred Blalock performed the first thymectomy for MG-associated thymoma in 1939 and extended the observation to non-thymomatous cases by 1944. Over the following seven decades, large institutional series consistently showed benefit — including complete remission in 30–50% of patients. But without a randomised trial, the evidence remained contested. Whether the benefit was real, or the result of selection bias in surgical series, could not be answered definitively.

The controversy lasted 75 years. MGTX ended it.

International · 2016

MGTX Trial

Wolfe et al. · New England Journal of Medicine · 2016 · 126 patients · 36 centres · 16 countries

AChR antibody-positive generalised MG, randomised: extended transsternal thymectomy plus prednisone versus prednisone alone. At three years, the thymectomy group had significantly better QMG (Quantitative Myasthenia Gravis) scores, required over 50% less prednisone, over 50% less azathioprine, over 50% fewer hospitalisations for MG exacerbation, and over 50% less intravenous immunoglobulin. The primary endpoint was met convincingly.

The trial used extended transsternal thymectomy — sternotomy. It did not test minimally invasive approaches. This is the honest limitation the evidence carries. See Section 4 for how robotic thymectomy addresses it.

International · 2019

MGTX Extension

Wolfe et al. · Lancet Neurology · 2019 · 2-year extension through month 60

A two-year extension study enrolled patients from the original MGTX who were willing to continue follow-up through 60 months. The benefits seen at three years were sustained through five years: thymectomy patients continued to show better symptom control and lower medication requirements. This longer-term confirmation strengthened the recommendation for thymectomy in the eligible patient group.

Results available through month 60 provide further evidence to support thymectomy in patients with generalised AChR-positive MG.

Robotic Evidence · 2024

Robotic vs Open — Equivalent Outcomes

Italian multicentre study · Cancers · 2024 · 213 patients · 6 centres · 2011–2021

A multicentre study of 213 myasthenic patients with thymic neoplasms treated robotically (n=103) versus open (n=110) demonstrated equivalent oncological radicality and neurological outcomes, with faster recovery in the robotic group. Systematic reviews confirm robotic thymectomy achieves significantly lower blood loss, fewer postoperative complications, and shorter hospital stay than open sternotomy, with comparable remission rates.

The robotic evidence specifically in non-thymomatous MG also supports equivalent results to sternotomy in remission and improvement rates, with the recovery advantages of avoiding sternal division.

The arc in one sentence

MGTX settled whether thymectomy works in 2016. The extension study confirmed it lasts in 2019. The robotic evidence now shows that the same benefit can be achieved without sternotomy — with the recovery advantages that matter most to a patient who is already managing a chronic neuromuscular disease.

Who Benefits from Surgery —
and Who Does Not

Thymectomy is not appropriate for every patient with myasthenia gravis. Getting this decision right — based on antibody type, disease severity, and thymic pathology — is as important as the operation itself. Surgery on the wrong patient carries morbidity without benefit.

Surgery recommended

AChR positive · Generalised MG

MGFA Classes II–IV. AChR antibody-positive, generalised disease. This is the group directly enrolled in MGTX. The evidence for benefit is robust. Thymectomy is recommended as part of treatment for patients in this group who are medically fit for surgery.

Always indicated for the tumour

Thymomatous MG

When a thymoma is present alongside MG, surgery is always indicated — for the oncological treatment of the tumour. MG management becomes part of the perioperative pathway rather than the indication for surgery. Neurological outcomes after thymectomy are equivalent in thymomatous and non-thymomatous MG.

Surgery not supported

Anti-MuSK positive · Non-thymomatous

Anti-MuSK positive non-thymomatous MG is a biologically distinct subtype. No thymic pathology is identified in this group. MGTX excluded MuSK-positive patients. Surgery does not have evidence of benefit and is not recommended. Management is medical, in collaboration with neurology.

Ocular MG only (MGFA Class I)

MGTX excluded patients with purely ocular MG. Evidence is insufficient to recommend thymectomy routinely for this group. Management is guided by neurological assessment. If there is uncertainty about classification or if disease is progressing toward generalisation, specialist neurology review is the appropriate first step.

Late-onset MG (>65 years)

MGTX enrolled patients aged 18–65. Evidence in older patients is limited and the balance between surgical morbidity and neurological benefit requires careful individual assessment. Decisions in this group are made jointly with the neurology team on a case-by-case basis.

At consultation, Dr Okiror reviews the antibody type, MGFA classification, disease duration, thymic imaging, and neurological history in collaboration with the specialist neurology team before recommending any surgical intervention. All cases are discussed at multidisciplinary team meeting. Where the indication for surgery is uncertain, that uncertainty is named — not resolved by assumption.

Robotic Thymectomy —
Completeness Without Sternotomy

MGTX used extended transsternal thymectomy — median sternotomy. The authors explicitly acknowledged that the trial did not test minimally invasive approaches. The legitimate concern about non-sternotomy techniques is completeness of thymic tissue removal: ectopic thymic tissue in the mediastinal fat, if not cleared, may limit neurological benefit.

This concern is answered by how the operation is defined, not by how the chest is opened. Extended thymectomy per ITMIG guidelines requires en-bloc removal of the thymic gland with the mediastinal adipose tissue between both phrenic nerves and the innominate vein. This tissue envelope is the same whether the access is via sternotomy or three small robotic incisions. The robotic platform — with magnified 3D vision and wristed instruments in a narrow retrosternal space — facilitates the meticulous dissection of ectopic tissue that this operation demands.

What robotic access then adds is the avoidance of sternotomy: a significantly shorter hospital stay, less post-operative pain, and a faster return to normal activity — outcomes that matter particularly to patients who are already managing a chronic neuromuscular disease that affects their daily function.

What the evidence shows for robotic vs open

Systematic review and meta-analysis (O’Sullivan et al., Annals of Cardiothoracic Surgery) comparing robotic versus open thymectomy across multiple studies showed:

  • Significantly lower blood loss (weighted mean difference −173ml)
  • Fewer postoperative complications (odds ratio 0.37)
  • Shorter hospital stay (mean 2.78 days less)
  • Lower positive margin rate
  • Comparable operative times and equivalent neurological outcomes
MG remission after robotic thymectomy

Published robotic thymectomy series in AChR-positive MG (Marcuse et al., Neuromuscular Disorders 2023, 236 patients) report:

  • 82.4% of patients improved in MG manifestations after surgery
  • 47.8% achieved complete stable or partial remission at mean 26 months
  • No surgical mortality in non-thymomatous patients
  • Mean hospital stay 3.3 days

Remission is typically gradual. Most benefit seen in first 2–3 years after surgery.

Before, During, and After —
What the Pathway Looks Like

Thymectomy for MG is not a straightforward thoracic surgical list case. The perioperative period requires coordinated planning between the surgical team, a specialist neurology team experienced in MG, and anaesthetists with specific expertise in neuromuscular disease.

Before surgery

Neurological optimisation

Acetylcholinesterase inhibitor dosing (pyridostigmine) is reviewed and adjusted. Immunosuppressant medications are managed in collaboration with the neurology team. For patients with poorly controlled or refractory MG — particularly those with significant bulbar or respiratory involvement — pre-operative stabilisation may require plasma exchange (plasmapheresis) or intravenous immunoglobulin (IVIg) in the weeks before surgery. Both reduce circulating AChR antibody levels and lower the risk of post-operative myasthenic crisis. The choice between them depends on disease severity, access, and the patient’s prior response. Baseline respiratory function (FVC/spirometry) is recorded before surgery as part of the monitoring framework.

Anaesthesia

Specialist anaesthetic expertise

Anaesthesia for MG thymectomy requires specific expertise. Depolarising neuromuscular blocking agents (suxamethonium) are contraindicated. Non-depolarising agents are used cautiously and at reduced doses because MG patients are sensitive to their effects. Volatile anaesthetic agents and certain antibiotics can potentiate neuromuscular blockade. Total intravenous anaesthesia (TIVA) is often preferred. The goal is to minimise residual neuromuscular blockade at the end of the procedure to facilitate early extubation and avoid post-operative ventilatory support. Dr Okiror works with anaesthetists who have specific experience in neuromuscular disease at London Bridge Hospital and The Lister Chelsea.

Surgery

Robotic extended thymectomy — ITMIG standard

The operation is a robotic extended thymectomy performed to ITMIG standard: en-bloc removal of the thymic gland with the anterior mediastinal adipose tissue between both phrenic nerves and the innominate vein. This tissue envelope captures both the main thymic body and the ectopic thymic tissue in the mediastinal fat — the completeness argument that sternotomy supporters have raised against minimally invasive approaches. Three small incisions. No sternotomy. Operating at London Bridge Hospital and The Lister Hospital Chelsea.

After surgery

Respiratory monitoring and neurological follow-up

Post-operative respiratory function is monitored systematically using a structured spirometry/FVC framework developed with the specialist MG team. Serial FVC measurements help detect early respiratory compromise that may precede a myasthenic crisis — the most serious post-operative risk. Most patients remain in hospital two to three days after robotic thymectomy. Pyridostigmine dosing is managed carefully in the post-operative period; MG can temporarily worsen in the weeks after surgery before neurological improvement begins. Follow-up with both the surgical and neurology teams is routine.

A High-Volume
Thymectomy Practice

Thymectomy for myasthenia gravis is not a high-volume operation in most thoracic units. Many surgeons perform only a handful per year. Volume matters here for the same reason it matters in any specialised surgery — familiarity with the perioperative neurology, the anaesthetic considerations, the completeness of dissection, and the post-operative monitoring.

The 2024 SCTS national audit reports that the thoracic surgical unit at Dr Okiror’s NHS base performs over 10% of all thymectomies across the United Kingdom and Ireland — the highest single-centre volume of thymic surgery in the country. This is published audit data from the Society for Cardiothoracic Surgery, not an internal claim. The same operative approach, the same perioperative framework, and the same standard of care apply to private patients seen at London Bridge Hospital and The Lister Hospital Chelsea.

Dr Okiror’s practice covers the full spectrum of thymectomy — from robotic thymectomy for non-thymomatous AChR-positive generalised MG, through to thymectomy for thymomatous MG, including international referrals for second opinion. As Clinical Audit Lead for Thoracic Surgery, he is responsible for the submission and verification of the unit data referenced above.

Where Surgery
Takes Place

Robotic thymectomy for myasthenia gravis is performed at London Bridge Hospital and The Lister Hospital Chelsea. Both hold the da Vinci Xi robotic platform and have access to anaesthetists experienced in neuromuscular disease. The choice between the two is usually a question of geography and convenience, discussed at consultation.

For patients with severe or refractory MG who require pre-operative plasma exchange or extended IVIg infusions, the perioperative pathway is most easily co-ordinated at London Bridge Hospital, which has the appropriate level of medical and neurology infrastructure on site.

Outpatient consultations are also available at HCA clinics in Canary Wharf and the City of London. International patients travelling specifically for MG thymectomy can be accommodated, with remote review of imaging and antibody panels arranged before travel.

Insurance and self-pay: Dr Okiror is recognised by all major UK private medical insurers including AXA, BUPA, WPA, Vitality, Cigna, and Aviva. Self-pay and international patients are equally welcome. Transparent estimates covering surgical, hospital, anaesthetic, and where relevant pre-operative plasma exchange or IVIg costs are provided by Jo Mitchelson before any commitment is made — 020 7952 2882 or pa@lungsurgeon.co.uk.

Thymoma and Myasthenia Gravis

Has a thymoma been found alongside your MG diagnosis?

When thymoma and MG coexist, surgery is always indicated for the oncological management of the tumour. The MG pathway described on this page forms the perioperative framework around that oncological decision. See the dedicated thymoma surgery page for staging, histological classification, and multimodality treatment options.

Thymoma Surgery →

Questions About
MG Surgery

Common questions from patients and families navigating a myasthenia gravis diagnosis and considering whether thymectomy is appropriate.

Book a Consultation →

Or call Jo Mitchelson:
020 7952 2882

What is myasthenia gravis?
Myasthenia gravis is an autoimmune disease in which antibodies attack the neuromuscular junction, causing fluctuating skeletal muscle weakness. The most common antibodies target the acetylcholine receptor (AChR), present in about 85% of generalised MG cases. About 70% of patients have thymic hyperplasia and 10-15% have a thymoma. The thymus is directly involved in the immune dysfunction, which is why removing it has a therapeutic effect in the right patients.
Does everyone with MG need surgery?
No. Surgery is supported by MGTX trial evidence for AChR antibody-positive generalised MG (MGFA Classes II-IV). It is always indicated when a thymoma is present. It is not recommended for anti-MuSK positive non-thymomatous MG or for purely ocular MG (MGFA Class I). Getting the patient selection right — based on antibody type, disease severity, and thymic pathology — is as important as the operation itself.
What is the MGTX trial?
The MGTX trial (Wolfe et al., NEJM 2016) was the first randomised controlled trial of thymectomy in non-thymomatous MG. 126 patients across 36 centres in 16 countries were randomised to extended transsternal thymectomy plus prednisone versus prednisone alone. At three years, the thymectomy group required over 50% less prednisone and azathioprine, had over 50% fewer hospitalisations, and showed significantly better disease scores. A 2019 extension study confirmed benefits were sustained through 60 months.
Why does the antibody type matter?
The antibody type determines whether thymectomy is likely to benefit you. AChR positive generalised MG is the group for whom MGTX demonstrated benefit. Anti-MuSK positive non-thymomatous MG is biologically distinct — no thymic pathology is found in this group and surgery has no evidence of benefit. Operating on the wrong patient carries morbidity without benefit. Accurate antibody testing before any surgical decision is essential.
Is robotic thymectomy as effective as sternotomy for MG?
MGTX used sternotomy and did not test robotic approaches. The legitimate concern is completeness of thymic tissue removal. Robotic extended thymectomy per ITMIG guidelines — en-bloc removal of thymus with mediastinal fat between both phrenic nerves — achieves the same tissue envelope as sternotomy. A 2024 multicentre Italian study (213 patients) showed equivalent neurological and oncological outcomes with faster recovery robotically. Systematic reviews confirm robotic thymectomy has lower blood loss, fewer complications, and shorter hospital stay than open surgery with comparable remission rates.
What happens if my MG is severe before surgery?
Patients with poorly controlled or refractory MG before surgery require neurological optimisation first. This may include review of acetylcholinesterase inhibitor dosing and, for severe or unstable disease, plasma exchange (plasmapheresis) or intravenous immunoglobulin (IVIg) pre-operatively. These reduce circulating AChR antibodies and lower the risk of post-operative myasthenic crisis. These decisions are made jointly between the surgical and specialist neurology teams.
What does remission from MG look like after surgery?
Remission is classified using MGFA Post-Intervention Status (PIS). Complete stable remission means no signs or symptoms for at least one year without medication. Pharmacological remission means no symptoms but some medication continues. Minimal manifestation status means very mild residual symptoms. Published robotic thymectomy series report improvement in over 80% of patients, with complete or partial remission in approximately 47-50% at 26 months. Remission is gradual — most benefit appears in the first two to three years after surgery.
Do I need a GP referral for a private MG surgery consultation?
No. Self-referrals are welcome. Appointments are typically available within 2–3 days at London Bridge Hospital, The Lister Hospital Chelsea, or Canary Wharf outpatients. If you have been diagnosed with MG and want to understand whether thymectomy is appropriate for your antibody type and disease pattern, contact Jo Mitchelson directly on 020 7952 2882 or pa@lungsurgeon.co.uk.

Book a Consultation

Appointments within 2–3 days. Self-referrals welcome. Surgery at London Bridge Hospital and The Lister Hospital Chelsea. No GP referral required.

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Jo Mitchelson, Private PA  · 020 7952 2882 · pa@lungsurgeon.co.uk

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