Trans-Cervical Thymectomy Under Local/Regional Anaesthesia in Treatment of Myasthenia Gravis

Background: Myasthenia Gravis (MG) is an auto-immune neuro-muscular disorder characterized by muscular fatigability and weakness of voluntary muscles. Thymectomy is the preferred method of treatment. Trans-sternal route is the standard approach to thymectomy, however, it necessitates general anaesthesia which is a challenge in MG and sternotomy further restrict the ventillatory function of myasthenics post-operatively.Purpose: Is to reveal the feasibility and safety of transcervical thymectomy (TCT) under local (cervical block) anesthesia with stepwise description of its technique.Patients and Methods: 15 patients with non-thymomatous MG (7 M 3 F) with a mean age of 44.8 y (30-60 y) were included from 2010-2011 and the eligibility criteria were; patients with non-thymomatous mild to moderate MG (Class 1-3 according to a modified Osserman classification) who are motivated to undergo TCT under local anaesthesia. Exclusion criteria were; thymomatous MG, class 4 MG with severe fulminant disease, unduly anxious or uncooperative patient, communication difficulty (language barrier or hearing deficit), associated endemic goiter or autoimmune thyroid disease,concomitant cervical lymphadenopathy, previous neck irradiation, previous neck surgery or sternotomy. All patients underwent bilateral superficial cervical block anaesthesia using 50:50 mixture of 0.5% lidocain and 0.25% bupivicain and TCT is done in the standard way apart from adding the step of intracapsular (intrathymic) injection of the local anaestetic. Post-operative chest X-ray was done for all patients to detect pneumothorax or phrenic nerve injury. Post-operative pain was assessed by visual analogue scale (Range, 0-10 ; 0 = No pain, 10 = Maximal pain).Results: All 15 procedures were successfully performed under loco-regional anaesthesia in a mean time of 59.5 minutes (50-90m, SD±7.97) with no conversion to general anesthesia or trans-sternotomy approach.Intra-operative discomfort was minimal and well tolerated. Intra-operative pleural leak was not observed in any of our patients with no post-operative pneumothorax. None of the patients complained of intra-operative or post-operative dyspnea and neither post-operative ventilation nor admission to intensive care unit was needed. No recurrent laryngeal nerve injury occurred and in only one case transient unilateral phrenic nerve palsy happened. No hypoparathyroidism occurred. A mean post-operative drainage of 53cc (30-100cc, SD±24.2) blood was obtained with no chylous leak in any of the cases. Only one case developed post-operative subcutaneous haematoma which was managed conservatively. Post-operative pain was well tolerated by all with a mean visual analogue scale of 0.4±0.1. All patients were satisfied of the procedure and the mean hospital stay was 39.3 hours (24- 48h, SD±8.28). Gross assessment of the extracted specimen revealed complete glandular lobar resection in all cases with a final histopathology of thymic hyperplasia.Conclusion: TCT under local (superficial cervical block anaesthesia) is feasible and safe, An addition that seems to potentially deserve consideration in the management of MG.