Comparison of two-lung and one-lung ventilation in bilateral video-assisted thoracoscopic extended thymectomy in myasthenia gravis: a retrospective study

Background: Myasthenia gravis (MG) is an autoimmune disease, and early thymectomy is recommended. Since the introduction of video-assisted thoracoscopic surgery, the safety and effectiveness of carbon dioxide insufflation in the thoracic cavity (capnothorax) has been controversial. This study aimed to compare the safety and effectiveness of ventilation methods in bilateral video-assisted thoracoscopic extended thymectomy (BVET) with capnothorax.Methods: We retrospectively investigated the medical records of patients with MG who underwent BVET between August 2016 and January 2018. Patients were divided into two groups: group D (n = 26) for one-lung ventilation and group S (n = 28) for two-lung ventilation. We set nine anesthesia time points (T0–T8) and collected respiratory and hemodynamic variables, including arterial O2 index (PaO2/FiO2).Results: SpO2 at T1–T3 and T8 was significantly lower in group D than in group S. The FiO2 in group S was lower than that in group D at all time points. The number of PaO2/FiO2 ≤ 300 and PaO2/FiO2 ≤ 200 events was significantly higher in group D than in group S. Hemodynamic variables were not significantly different between the two groups at any time point. The duration of surgery and anesthesia was shorter in group S than in group D. Conclusions: This retrospective study suggests that anesthesia using two-lung ventilation during BVET with capnothorax is a safe and effective method to improve lung oxygenation and reduce anesthesia time.

Non-intubated uniportal subxiphoid thoracoscopic extended thymectomy for thymoma associated with myasthenia gravis

Background To describe a technique of non-intubated uniportal subxiphoid thoracoscopic extended thymectomy. Methods Data were collected retrospectively. A single 3-cm transverse incision was made below the xiphoid process. This method for extended thymectomy entails adoption of uniportal subxiphoid VATS combined with using of non-intubated anesthesia for thymoma associated with myasthenia gravis. Results Ten consecutive patients underwent this procedure successfully. Mean operative time was 102.5 min. Conversion to intubated ventilation or thoracotomy was not required. Mean chest tube duration was 3.5 days. Mean postoperative hospital stay was 4.7 days. Histologic examination showed early-stage thymomas. Side effects were rare. Quantitative MG scores decreased during follow-up. Conclusions Patients were uneventfully discharged with fast recovery. This technique may merge the potential benefits of a subxiphoid incision and the non-intubated anesthesia protocol.

The Safety and Feasibility of Laryngeal Mask Airway (LMA) Management in Non-intubated Subxiphoid-subcostal Thoracoscopic Thymectomy: Preliminary Results

Intubated general anesthesia and single-lung ventilation are considered mandatory for conventional thoracoscopic surgery. Non-intubated thoracoscopic thymectomy is technically challenging. The aim of this article was to present the initial results of non-intubated subxiphoid-subcostal thoracoscopic thymectomy (NI-STT) under LMA management for patients with thymic tumor or myasthenia gravis (MG) and to investigate the feasibility and safety of the procedure. A retrospective analysis of patients undergoing NI-STT for thymic tumor or MG at our department from January 2017 to January 2020 was performed. The clinical characteristics and perioperative outcomes of the patients were reviewed and analyzed. A total of 61 patients were received NI-STT in this analysis, of which 19 patients with MG undergone an extended thymectomy and the rest (n=42) undergone a partial thymectomy. The anesthetic induction duration, surgical duration and global operating room duration were 24.83±12.27 min, 118.75±32.49 min and 173.51±41.80 min, respectively. The lowest SpO2 and peak EtCO2 during operation were 96.15±2.93 mmHg and 41.79±7.53 mmHg, respectively. The mean duration of chest drainage and postoperative hospital stays were 1.87 days, and 2.91 days, respectively. Three cases had sore throat and irritable cough and two cases suffered nausea and vomiting occurred. one patient suffered from an atrial fibrillation, two patients experienced pneumonia, and one patient suffered wound infection, respectively. There were no phrenic nerve paralysis and mortality occurred in the study group. The postoperative pain was low on 1,3, 7, 14, 30, 90 and 180 postoperative days. NI-STT was a technically safe and feasible approach for treating thymic tumors or MG. It could be an alternative to intubated single-lung ventilation for thymectomy in selected patients.

Factors affecting improvement of neurologic status evaluated by Quantitative Myasthenia Gravis Score for patients with thymomatous myasthenia gravis after extended thymectomy

Background The length of time for clinical improvement of patients with thymomatous myasthenia gravis (MG) after extended thymectomy is not clear. The purpose of this study was to determine the length of time after thymectomy in patients with thymomatous MG to achieve a 3-point reduction of Quantitative Myasthenia Gravis Score (QMGS), and identify variables associated with a failure to achieve the reduction. Methods The records of patients with thymomatous MG who underwent extended thymectomy from January 2005 to December 2018 were retrospectively reviewed. The primary end point was a reduction of 3 points of QMGs and the secondary end point was another reduction of 3 points of QMGs. Results A total of 481 patients were included in the analysis, the mean age of the patients was 41.63 ± 8.55 years, and approximately 60% were male. The median time to achieve a 3 point decrease in QMGS was 6 months, and the median time to achieve another 3 point decrease was 30 months. Multivariable analysis indicated that age ≥ 42 years and Masaoka-Koga stage > I were associated with a lower probability of achieving a 3 point decrease in QMGS (HR = 0.55 and 0.65, respectively). Likewise, multivariable analysis indicated that age ≥ 42 years and Masaoka-Koga stage > I were associated with a lower probability of achieving a second 3 point decrease in QMGS (HR = 0.53 and 0.53, respectively). Conclusions In patients with thymomatous MG who receive thymectomy, age ≥ 42 years and Masaoka-Koga stage > I are associated with a worse prognosis and failure to achieve a 3 point decrease in QMGS.

Factors Affecting Improvement of Neurologic Status Evaluated by Quantitative Myasthenia Gravis Score for Patients With Thymomatous Myasthenia Gravis After Extended Thymectomy

Background: The length of time for clinical improvement of patients with thymomatous myasthenia gravis (MG) after extended thymectomy is not clear. The purpose of this study was to determine the length of time after thymectomy in patients with thymomatous MG to achieve a 3-point reduction of Quantitative Myasthenia Gravis Score (QMGS), and identify variables associated with a failure to achieve the reduction. Methods: The records of patients with thymomatous MG who underwent extended thymectomy from January 2005 to December 2018 were retrospectively reviewed. The primary end point was a reduction of 3 points of QMGs and the secondary end point was another reduction of 3 points of QMGs. Results: A total of 481 patients were included in the analysis, the mean age of the patients was 41.63 ± 8.55 years, and approximately 60% were male. The median time to achieve a 3 point decrease in QMGS was 6 months, and the median time to achieve another 3 point decrease was 30 months. Multivariable analysis indicated that age ≥ 42 years and Masaoka-Koga stage > I were associated with a lower probability of achieving a 3 point decrease in QMGS (HR = 0.55 and 0.65, respectively). Likewise, multivariable analysis indicated that age ≥ 42 years and Masaoka-Koga stage > I were associated with a lower probability of achieving a second 3 point decrease in QMGS (HR = 0.53 and 0.53, respectively).Conclusions: In patients with thymomatous MG who receive thymectomy, age ≥ 42 years and Masaoka-Koga stage > I are associated with a worse prognosis and failure to achieve a 3 point decrease in QMGS.