The comparison of modified minimally invasive and open surgical approaches in the treatment of epithelial thymic tumours.

Abstract

Exploring the efficacy of a modified combined minimally invasive approach in patients with thymoma regardless of myasthenia gravis involvement in contrast to open surgery as the mainstay of treatment. Primary epithelial thymic tumours are rare malignancies of the anterior mediastinum, often present with myasthenia gravis, and with good prognosis when assuming complete surgical resection. We present amodified mini-invasive technique (MIT) that is unique in its extent. Fifty-two patients were included in this retrospective study. Two groups of patients who had undergone different types of surgery were compared using the Mann-Whitney test (ordinal variables) and Fisher's exact test (binary variables). Changes after completing the surgical learning curve were observed. There was astatistical difference when comparing early Masaoka stages (I‒II) with later stages in favour of the mini-invasive method (p=0.013). The duration of surgery was longer in the mini‑invasive group with amedian value of 260 vs 133 min (p=0.001). The analysis of operation times revealed that after overcoming the learning curve period, the duration of surgery decreased (2008‒2012: 297 min; 2013‒2018: 199 min; p=0.005). The systemic complication rate was lower in the mini‑invasive method (26.1 % vs 3.4 %; p=0.035). Our results showed the modified maximal minimally invasive thymectomy to be an effective and safe method, and after overcoming the learning curve, even superior to open surgery in cases with lower tumour stages in terms of its extent (Tab. 3, Fig. 1, Ref. 49).