Long-term outcome and factors influencing the outcome of thymectomy for myasthenia gravis.

Thymectomy has gained widespread acceptance as a treatment for patients with myasthenia gravis (MG). Patients with myasthenia gravis who had undergone thymectomy by extended transsternal approach between 1981 and 1987 were retrospectively reviewed to evaluate the result of thymectomy, time to remission, time to maximum improvement and factors influencing remission after thymectomy. There were 128 patients, 45 men and 83 women and the mean ages at the time of thymectomy were 35.7 and 32.2 years respectively. After thymectomy, 41.2% of the patients were in remission, 53% improved and 5.8% had no response. The remission rates at 1, 2, 5 and 10 years after thymectomy were 9%, 17%, 37% and 53% respectively and the median time to remission was 9 years. The maximum improvement rates at 1, 2, 5 and 10 years after thymectomy were estimated to be 30%, 40%, 57% and 78% respectively and the median time to maximum improvement was 3.6 years. Patients with ocular MG, longer duration of symptoms before thymectomy and atrophic thymus gland appeared to take longer to achieve remission although none of the factors was significantly associated with the time to remission. Thymectomy is beneficialfor MG patients with satisfactory remission and improvement rates. It is recommended that thymectomy should be advocatedfor these patients early in the course of the disease because the duration of the symptoms appeared to be the main determinant of the outcome.

Modified cox maze procedure for atrial fibrillation with mitral valve diseaset.

OBJECTIVE: To determine early term results of the modified Cox maze procedure for curing atrial fibrillation (AF) associated with mitral valve disease. METHOD: Between January and December 2000, 10 consecutive patients with AF underwent the modified Cox maze procedure with mitral valve repair in 2 and replacement in 8. The associated procedure included 3 aortic valve replacements, 1 tricuspid annuloplasty, and 2 atrial septal defect closures. There were 5 males and 5 females, with ages ranging from 19 to 52 years (mean = 38.3 years). Pre-operative-existing AF time varied from 4 to 146 months (mean = 41.1 months), and left atrial dimension varied from 4.50 to 6.89 cm (mean 5.51 cm). The authors modified the maze atriotomies to preserve the sinus node artery and used cryoablation, incision and suture to simplify the procedures. RESULTS: Seven cases (70%) regained sinus rhythm and 3 cases (30%) still remained in AF. Two cases (double valve replacement) needed intraaortic balloon pump. Two of them developed cardiac tamponade 1 month post-operatively, (one in sinus rhythm case and another one in AF). Those 3 patients who remained in AF had a longer pre-operative existing AF-time and larger left atrial dimension but it was insignificant (p = 0.227 and p = 0.187 respectively). There was no early or late mortality. CONCLUSION: The pertaining results suggest that the modified Cox maze procedure has satisfactory effectiveness to cure atrial fibrillation, restore atrioventricular synchrony and preserve atrial transport function in the patients having AF associated with mitral valve disease.