Clinical characteristics and management of primary mediastinal cysts: A single-center experience

Abstract

Background: In this study we aimed to assess the clinical outcomes of performing video-assisted thoracic surgery (VATS) to treat primary mediastinal cysts (PMCs) and investigate the clinical factors which increase the difficulties associated with VATS.

Methods: The medical records of all consecutive PMC patients, who underwent surgical resection from April 2001 to July 2016, were reviewed and 282 patients were included. Clinical characteristics, imaging features, and surgical outcomes were analyzed. Follow-up data were successfully obtained from 230 PMC patients by telephone or outpatient clinic annually. The latest follow-up was July 2019.

Results: VATS was performed in 278 patients and four patients were converted into thoracotomy. The mean operation time and intraoperative bleeding were 102.4 ± 40.9 minutes (range 25-360 minutes) and 52.4 ± 75.1 mL (range 5-600 mL), respectively. The intra- and postoperative complication rates were 2.8 and 5.7%, respectively. Seven patients with bronchogenic cysts showed severe cyst adhesion to vital mediastinal structures and thus had incomplete resection. Multivariable logistic analysis revealed that a maximal cyst diameter greater than 5 cm was significantly associated with increased risks of operation time extension (OR = 2.106; 95% CI: 1.147-3.865, P = 0.016) and intraoperative blood loss increase (OR = 4.428; 95% CI: 1.243-16.489, P = 0.022). A total of 230 patients had follow-up data. The median follow-up time was 70 months (range, 36-210 months). No local recurrence was observed.

Conclusions: Surgical resection by VATS may be recommended for PMC management as a primary therapeutic strategy. Cysts with a maximum diameter greater than 5 cm or cysts adjacent to vital mediastinal structures can increase the surgical difficulties.

Key points: • Significant findings of the study A diameter >5 cm and adhesions significantly increased the risk of operation time extension together with increased blood loss. • What this study adds Cysts with a diameter >5 cm or those adjacent to vital mediastinal structures increased the potential for surgical difficulties.

Keywords: Bronchogenic cyst; primary mediastinal cyst; thymic cyst; video-assisted thoracic surgery (VATS).

Figure 1

Flow diagram for the patient selection included in this study.

Figure 2

The number of operations, operative duration and intraoperative bleeding of each year (2001–2016). () Number of operation, () Intraoperative bleeding (mL), and () Operation time (minutes).

Figure 3

Chest CT showed two primary mediastinal cysts with serious complications caused by the compression of the cysts. (a) A giant mediastinal bronchogenic cyst compressed the right thoracic cavity severely and led to the deformity of the trachea. (b) Compression of the esophagus by an esophageal cyst which led to dysphagia (arrow).

Figure 4

Chest CT and the resected specimen performance of pericardial cysts with severe adhesion to the left lung and chest wall which caused a severe inflammatory reaction around the cyst (arrow).