Abstract
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 trans-cervical 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 irradi-ation, 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 oc-curred. 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 subcutane-ous 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. |
