Journal of Medical and Surgical
Research (JMSR)


Pages: 1247-1254DOI: 10.46327/msrjg.1.000000000000250

Date of Publication: 30-Nov--0001

Predictive Factors of Post- Operative Myasthenic Crisis after Thymectomy In Moroccan Patients with Myasthenia Gravis:

A Retrospective Analysis of 30 Cases.

Author: Fatima Zahra Haddari, Soumaya Touzani, Abderrahim El Bouazzaoui, Nawfal Houari, Brahim Boukatta, Nabil Kanjaa

Category: JMSR Anesthesiology and IC

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Introduction: Myasthenia crisis (MC) occurs in 15 % to 20 % of myasthenia gravis (MG) patients. How to prevent post-operative myasthenic crisis (POMC) is of great importance to the treatment of post-surgery MG patients. Methods: Retrospective study including myasthenia patients who underwent thymectomy and were admitted to our unit from January 2013 to December 2019. Variables analyzed were age, gender, history of MC, duration of disease, diagnostic parameters, preoperative functional muscle and Leventhal scores, Ossermann classification, patient comorbidities, treatment, and outcomes. Results: Thirty patients were included in this study. The mean age was 36.86 years. The sex ratio M/F was 0.30. Twenty percent of the patients had a history of MC. Bulbar symptoms were present in 50 % of cases. Anti-acetylcholine receptor antibodies were positive in 93 % of cases. The functional muscle score varied between 60 and 100 points with a mean of 83.63 points. The mean vital capacity was 3.302 liters. The Leventhal score was greater than 10 in five patients. Curarization was necessary in 25 patients and monitored in four cases. Surgical approach was median sternotomy in 86.67 % of cases and mean surgery duration was 159.83 minutes. The univariate analysis identified 5 variables significantly (p < 0.05) associated with the occurrence of POMC: Leventhal score > 10, weak functional muscle score, low vital capacity, prolonged duration of surgery, and prolonged length of ICU stay. Conclusion : Leventhal score > 10, weak functional muscle score, low vital capacity and prolonged surgery duration were independent risk factors for POMC.

Keywords: Morocco, Myasthenia Crisis, Myasthenia Gravis, Risk Factors, Thymectomy


[1] Gilhus NE. Myasthenia Gravis. N Engl J Med. 2016; 375: 2570-2581.

[2] Wolfe GI, Kaminski HJ, Aban IB, Minisman G, Kuo HC, Marx A, Ströbel P, Mazia C, Oger J, Cea JG, Heckmann JM, Evoli A, Nix W, Ciafaloni E, Antonini G, Witoonpanich R, King JO, Beydoun SR, Chalk CH, Barboi AC, et al. Randomized trial of thymectomy in myasthenia gravis. N Engl J Med. 2016; 375: 511-522.

[3] Taioli E, Paschal PK, Liu B, Kaufman AJ, Flores RM. Comparison of conservative treatment and thymectomy on myasthenia gravis outcome. Ann Thorac Surg. 2016; 102: 1805-1813.

[4] Chigurupati K, Gadhinglajkar S, Sreedhar R, Nair M, Unnikrishnan M; Pillai M. Criteria for postoperative mechanical ventilation after thymectomy in patients with myasthenia gravis: a retrospective analysis. J Cardiothorac Vasc Anesth. 2018; 32: 325-330.

[5] Li Y, Wang H, Chen P, Chen Z, Su C, Luo C, Feng H, Liu W. Clinical outcome and predictive factors of postoperative myasthenic crisis in 173 thymomatous myasthenia gravis patients. Int J Neurosci. 2018; 128: 103-109.

[6] Wong YS, Ong CT, Sung SF, Wu CS, Hsu YC, Su YH, Hung LC. Clinical Profile and outcome of myasthenic crisis in central Taiwan. Acta Neurol Taiwan. 2016; 25: 129-135.

[7] Nam TS, Lee SH, Kim BC, Choi KH, Kim JT, Kim MK, Cho KH, Lee MC. Clinical characteristics and predictive factors of myasthenic crisis after thymectomy. J Clin Neurosci 2011; 18: 1185–8.

[8] Kanai T, Uzawa A, Sato Y, Suzuki S, Kawaguchi N, Himuro K, Oda F, Ozawa Y, Nakahara J, Suzuki N, Takahashi YK, Ishibashi S, Yokota T, Ogawa T, Yokoyama K, Hattori N, Izaki S, Oji S, Nomura K, Kaneko J, et al. A clinical predictive score for postoperative myasthenic crisis. Ann Neurol 2017; 82: 841–9.

[9] Yu S, Lin J, Fu X, Li J, Li Y, Chen B, Yang M, Zhang M, Bu B. Risk factors of myasthenic crisis after thymectomy in 178 generalized myasthenia gravis patients in a five-year follow-up study. Int J Neurosci. 2014; 124: 792-798.

[10] Xue L, Wang L, Dong J, Yuan Y, Fan H, Zhang Y, Wang Q, Ding J. Risk factors of myasthenic crisis after thymectomy for thymoma patients with myasthenia gravis. Eur J Cardiothorac Surg. 2017; 52: 692-697.

[11] Chu XY, Xue ZQ, Wang RW, Tan QY. Predictors of postoperative myasthenic crisis in patients with myasthenia gravis after thymectomy. Chin Med J (Engl). 2011; 124: 1246-1250.

[12] Watanabe A, Watanabe T, Obama T, Mawatari T, Ohsawa H, Ichimiya Y, Takahashi N, Kusajima K, Abe T. Prognostic factors for myasthenic crisis after transsternal thymectomy in patients with myasthenia gravis. J Thorac Cardiovasc Surg 2004; 127: 868–76.

[13] Ciafaloni E, Sanders DB. Advances in myasthenia gravis. Curr Neurol Neurosci Rep 2002; 2: 89–95.

[14] S. Lammens, B. Eymard, B. Plaud. Anesthésie et myasthénie. EMC (Elsevier Masson SAS, Paris), Anesthésie-Réanimation, 36-657-C-10, 2010.

[15] Ying Huang, Lei Su, Yi Zhang, Julong Guo, Chunmei Wang. Risk Factors for Postoperative Myasthenic Crisis After Thymectomy in Patients With Myasthenia Gravis. Journal of surgical research. 2021; 262: 1-5.

[16] Liu Z, Yao S, Zhou Q, Deng Z, Zou J, Feng H, Zhu H, Cheng C. Predictors of extubation outcomes following myasthenic crisis. J Int Med Res. 2016; 44: 1524-1533.

[17] Ando T, Omasa M, Kondo T, Yamada T, Sato M, Menju T, Aoyama A, Sato T, Chen F, Sonobe M, Date H. Predictive factors of myasthenic crisis after extended thymectomy for patients with myasthenia gravis. Eur J Cardiothorac Surg. 2015; 48: 705-709. discussion 709.

[18] Li KK, Qian K, Feng YG, Guo W, Tan QY, Deng B. Predictive factors of prolonged mechanical ventilation, overall survival, and quality of life in patients with post-thymectomy myasthenic crisis. World J Surg Oncol. 2017; 15: 150.

[19] Geng Y, Zhang H, Wang Y. Risk factors of myasthenia crisis after thymectomy among myasthenia gravis patients: a meta-analysis. Medicine (Baltimore). 2020; 99: e18622.

[20] Akaishi T, Motomura M, Shiraishi H, Yoshimura S, Abe M, Ishii T, Aoki M. Preoperative risks of post-operative myasthenic crisis (POMC): a meta-analysis. J Neurol Sci. 2019; 407: 116530.

[21] Kirsch JR, Diringer MN, Borel CO, Hanley DF, Merritt WT, Bulkley GB. Preoperative lumbar epidural morphine improves postoperative analgesia and ventilatory function after transsternal thymectomy in patients with myasthenia gravis. Crit Care Med 1991; 19: 1474–9.

[22] Liu XZ, Wei CW, Wang HY, Ge YH, Chen J, Wang J, Zhang Y. Effects of general-epidural anaesthesia on haemodynamics in patients with myasthenia gravis. West Indian Med J 2015; 64: 99–103.

[23] Itoh H, Shibata K, Nitta S. Difference in sensitivity to vecuronium between patients with ocular and generalized myasthenia gravis. Br J Anaesth 2001; 87: 885-9.

[24] Sungur Ulke Z, Yavru A, Camci E, Ozkan B, Toker A, Senturk M. Rocuronium and sugammadex in patients with myasthenia gravis undergoing thymectomy. Acta Anaesthesiol Scand 2013; 57: 745–8.

[25] Murray MJ, DeBlock HF, Erstad BL, Gray Jr AW, Jacobi J, Jordan CJ, McGee WT, McManus C, Meade MO, Nix SA, Patterson AJ, Sands K, Pino RM, Tescher AN, Arbour R, Rochwerg B, Murray CF, Mehta S. Clinical practice guidelines for sustained neuromuscular blockade in the adult critically ill patient: 2016 update—executive summary. Am J Health-Syst Pharm 2017; 74: 76–8.

[26] Cata JP, Lasala JD, Williams W, Mena GE. Myasthenia Gravis and Thymoma Surgery: A Clinical Update for the Cardiothoracic Anesthesiologist. Journal of Cardiothoracic and Vascular Anesthesia 2019; 33: 2537- 2545.

[27] Burt BM, Yao X, Shrager J, Antonicelli A, Padda S, Reiss J, Wakelee H, Su S, Huang J, Scott W. Determinants of complete resection of thymoma by minimally invasive and open thymectomy: analysis of an international registry. J Thorac Oncol 2017; 12: 129–36.

[28] Lee CY, Kim DJ, Lee JG, Park IK, Bae MK, Chung KY. Bilateral video-assisted thoracoscopic thymectomy has a surgical extent similar to that of transsternal extended thymectomy with more favorable early surgical outcomes for myasthenia gravis patients. Surg Endosc 2011; 25: 849–54.

[29] He Z, Zhu Q, Wen W, Chen L, Xu H, Li H. Surgical approaches for stage I and II thymoma-associated myasthenia gravis: feasibility of complete videoassisted thoracoscopic surgery (VATS) thymectomy in comparison with trans-sternal resection. J Biomed Res 2013; 27: 62–70.

[30] Gung Y, Zhang H, Li S. Sternotomy versus video-assisted thoracoscopic surgery for thymectomy of myasthenia gravis patients: a meta-analysis 2016; 9: 285–94.

[31] Zou J, Su C, Lun X, Liu W, Yang W, Zhong B, Zhu H, Lei Y, Luo H, Chen Z. Preoperative anxiety in patients with myasthenia gravis and risk for myasthenic crisis after extended transsternal thymectomy: a CONSORT study. Medicine (Baltimore) 2016; 95: e2828.

[32] Leuzzi G, Meacci E, Cusumano G, Cesario A, Chiappetta M, Dall'armi V, Evoli A, Costa R, Lococo F, Primieri P, Margaritora S, Granone P. Thymectomy in myasthenia gravis: proposal for a predictive score of postoperative myasthenic crisis. Eur J Cardiothorac Surg 2014; 45: e76–88. discussion e88.

[33] Wu Y, Chen Y, Liu H, Zou S. Risk factors for developing postthymectomy myasthenic crisis in Thymoma Patients. J Cancer Res Ther 2015; 11 Suppl 1:C115–117.

[34] Yamada Y, Yoshida S, Suzuki H, Tagawa T, Iwata T, Mizobuchi T, Kawaguchi N, Yoshino I. Efficacy of perioperative highdose prednisolone therapy during thymectomy in myasthenia gravis patients. J Cardiothorac Surg 2013; 8: 226.