The Curative Effect of Extended Thymectomy Performed Through Subxiphoid-right VATS Approach With Elevation of Sternum

Study Overview
=================
Brief Summary
-----------------
Extended thymectomy is the main treatment for thymoma and other anterior mediastinal diseases. Video-assisted thoracic surgery(VATS) plays an important role in the surgery of extended thymectomy. Now, VATS thymectomy through intercostal approach has been the commonly used minimally invasive surgical procedure for thymus surgery and is applied worldwide. But the intercostal approach may cause residue of thymus tissue and chronic pain. In 2013, doctor Marcin Zielin´ski form Poland reported a new technique of minimally invasive extended thymectomy performed through the VATS approach with double elevation of the sternum. And their early results proved this technique is probably the least invasive and the most complete technique of VATS thymectomy with excellent cosmetic results. Until now, doctor Jiang Fan form Shanghai Pulmonary Hospital has performed 50 cases extended thymectomy through the subxiphoid approach with double elevation of the sternum by VATS. This study is designed to compare the curative effect between this new method and traditional intercostal VATS.

Detailed Description
-----------------
This study is a prospective multicentre cohort study.The main study content is comparative study of the curative effect of extended thymectomy performed through the subxiphoid-right video-thoracoscopic approach with double elevation of the sternum versus intercostal video-thoracoscopic approach, divided into subxiphoid and intercostal groups. Communicating with the surgeon and patients who meet the inclusion criteria, decide whether to enter the subxiphoid or intercostal group. Subxiphoid group with subxiphoid-right video-thoracoscopic approach under double elevation of the sternum in extended thymectomy , intercostal group with traditional intercostal video-assisted thoracoscopic surgery in extended thymectomy. By collecting personal information of two groups of patients and the corresponding observation indicators to analyze whether the subxiphoid-right VATS approach with double elevation of the sternum is the least invasive and the most complete technique of VATS thymectomy.

Official Title
-----------------
A Prospective Multicenter Comparative Study of the Curative Effect of Extended Thymectomy Performed Through the Subxiphoid VATS Approach With Double Elevation of the Sternum Versus Intercostal VATS Approach

Conditions
-----------------
Thymoma, Myasthenia Gravis, Mediastinal Tumor

Intervention / Treatment
-----------------
* Procedure: Subxiphoid approach extended thymectomy by VATS
* Procedure: Intercostal approach extended thymectomy by VATS


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: MG with thymic hyperplasia, thymoma or other anterior mediastinum disease Masaoka stagingⅠ-Ⅱ Patients with normal cardio-pulmonary function before operation, BMI<30 Exclusion Criteria: Unable to tolerate surgery Masaoka staging Ⅲ-Ⅳ Patients who have undergone previous surgery or radiotherapy Myasthenia crisis Chronic pain or using opioid analgesics before surgery Preoperative mental disorders such as excessive anxiety Patients who underwent previous mediastinal surgery or cardiac surgery Patients with thoracic deformity

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: This study is a prospective multicentre cohort study.The main study content is comparative study of the curative effect of extended thymectomy performed through the subxiphoid-right video-thoracoscopic approach with double elevation of the sternum versus intercostal video-thoracoscopic approach, divided into subxiphoid and intercostal groups. Communicating with the surgeon and patients who meet the inclusion criteria, decide whether to enter the subxiphoid or intercostal group. Subxiphoid group with subxiphoid-right video-thoracoscopic approach under double elevation of the sternum in extended thymectomy , intercostal group with traditional intercostal video-assisted thoracoscopic surgery in extended thymectomy.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Subxiphoid approach<br>The patients in subxiphoid group will get subxiphoid approach extended thymectomy by VATS. Whole dissection was performed through a 4 to 7cm transverse subxiphoid incision, and a single 5-mm port was inserted into the right chest cavity for the video thoracoscope and subsequently for the chest tube. The sternum was elevated with two hooks connected to the sternal frame. The lower hook was inserted through the subxiphoid incision, and the superior hook was inserted percutaneously after the mediastinal tissue including the major mediastinal vessels was dissected from the inner surface of the sternum. The thymus and fatty tissue of the anterior mediastinum and the aorta-pulmonary window was completely removed. | Procedure: Subxiphoid approach extended thymectomy by VATS<br>* Extended thymectomy performed through the subxiphoid-right VATS approach with double elevation of the sternum<br>|
| Experimental: Intercostal approach<br>The patients in intercostal group will get intercostal approach extended thymectomy by VATS. | Procedure: Intercostal approach extended thymectomy by VATS<br>* Extended thymectomy performed through the traditional intercostal VATS approach<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Resection rate of thymus tissue | The thymus tissue resection rate was calculated by comparing the preoperative and postoperative CT images. | 1 month | 
| Acute Pain Score | Visual analogue score (VAS-score) is to asses the development of acute pain after surgery. 11 point numeric rating scale of 0 represented no painand a score of 10 represented worst pain  in patients 24 hours after operation. | 24 hours | 
| Life Quality of Patients | The EuroQol 5 Dimensions (EQ-5D) is used. EQ-5D is a standardized instrument developed by the EuroQol Group as a measure of health-related quality of life that can be used in a wide range of health conditions and treatments. EQ-5D includes self-reported quality of life, where 0 is the worst and 100 is the best imaginable health state. | 6 months | 
| Myasthenia Gravis remission rate | The Quantitative Myasthenia Gravis scale (QMG) is used. It includes 13 items, such as eyelid ptosis, diplopia, eyelid closure, speech, swallowing, vital capacity, lift, grip and lower extremity elevation. QMG can evaluate myasthenia, and total score of the scale is from 0 (no myasthenia) to 39 (the most severe myasthenia). If the difference between the two assessment scores is greater than 3.5, it is considered that the symptoms of myasthenia gravis relieved. | 1 year | 
| Disease-free survival | From grouping to the recurrence of disease or the time of death due to disease progression. | Up to 5 years | 
| Recurrence rate | The rate of patients recurrence after surgery | Up to 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mortality rate | Death caused by operation or complications | Up to 5 years | 
| Overall survival | From grouping to any cause of death | Up to 5 years | 
| Operation time | Time of the surgical operation | 1 week | 
| Length of stay | The time of the patients in hospital | 1 month | 
| Complication rate | The incidence rate of postoperative complications in the two groups | 1 month | 
| Chronic Pain Score | Visual analogue score (VAS-score) is to asses the development of chronic pain after surgery. 11 point numeric rating scale of 0 represented no painand a score of 10 represented worst pain  in patients 6 months after operation. | 6 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
thymoma, thymectomy, Myasthenia Gravis, VATS, subxiphoid, elevation of the sternum, curative effect