Video-assisted thoracoscopic resection of a bronchogenic esophageal cyst.

Bronchogenic cysts are lesions of congenital origin derived from the primitive foregut. The usual presentation of bronchogenic cyst in the mediastinum is related to cyst infection or adjacent organs compression. A case of a bronchogenic esophageal cyst presenting with progressive dysphagia in a 46-year-old man is described. A video-assisted thoracoscopic excision was performed successfully. Details of the procedure are discussed.

INTRODUCTION

Benign cysts of the esophagus are rare and account for less than 20% of all benign esophageal tumors. Such cysts may be of congenital or acquired origin. Three theories of origin have been proposed for the congenital lesions. These theories postulate neurenteric, bronchogenic and intramural duplication origins. The lack of agreement between authors confirms that the aetiology remains uncertain.[1] A case of a bronchogenic esophageal cyst presenting with progressive dysphagia in a 46-year-old man is described. He was investigated by barium meal [Figure 1] and endoscopy, demonstrating a smooth ovoid swelling within the wall of distal esophagus. Transesophageal endoscopic ultrasound revealed benign ultrasonographic characteristics [Figure 2]. A chest CT scan showed a paraesophageal cystic mass in the posterior mediastinum with a well-defined capsule and lack of enhancement after intravenous contrast injection [Figure 3]. Preoperative bronchoscopy excluded any communication between the cyst and the tracheobronchial tree. Complete staging (abdominal and brain CTs) and bone scan were negative for possible malignancy. The patient was considered eligible for surgical treatment by means of minimally invasive technique. A video-assisted thoracoscopic excision (VATS) was performed successfully.

Figure 1

The barium meal revealing esophageal compression by the lesion

Figure 2

Transesophageal ultrasound was consistent with a lesion with benign characteristics

Figure 3

Chest CT scan showing a paraesophageal cystic mass with a well-defi ned capsule and lack of enhancement after intravenous contrast injection

PREOPERATIVE PREPARATION

The usual preoperative preparation for a right thoracotomy was performed.

Positioning of patient and ports

After induction of general anesthesia, double-lumen endotracheal intubation, nasogastric tube placement, central venous and arterial catheter insertion, the patient is placed in the left lateral decubitus position. Three ports are placed through three 5- or 10-mm incisions. One on the fifth intercostal space along the anterior axillary line; one on the fifth intercostal space along the posterior axillary line and the last one on the seventh intercostal space along the midaxillary line [Figure 4].

Figure 4

Incisions for the port placement

OPERATIVE STEPS

The surgical technique consists of four steps: 1. trocar placement and exposure, 2. dissection and excision of the lesion, 3. control of integrity of esophageal mucosa, 4. reconstruction of the esophageal wall, 5. drain placement and closure.

The three ports were placed as mentioned above. The 0o thoracoscope provided an excellent view of the posterior mediastinum and esophagus. Following the port placement, the swelling was easily seen in the lower esophagus through the intact mediastinal pleura [Figure 5]. Mild retraction of the right lower lobe and dissection of the inferior pulmonary ligament made the cyst to be easily exposed. Mediastinal pleura were divided to expose fully the cystic lesion and the distal esophagus [Figure 6]. The cystic lesion was readily separated from the adjacent muscle and intact underlying mucosa by a combination of diathermy, endopeanut dissection and endoscissors dissection. The specimen was easily retrieved through an endo-catch bag [Figure 7].

Figure 5

The bronchogenic esophageal cyst exposed well following inferior pulmonary ligament dissection

Figure 6

Endoscissors dissection of the muscular esophageal layer

Figure 7

Retrieval of the specimen through an endo-catch bag

The integrity of esophageal mucosa was controlled with absence of leaks by insufflating air into the esophageal lumen through the nasogastric tube. The dissected esophageal muscular layer was reapproximated with separate endo-stiches (Vicryl 3-0) in order to avoid pseudodiverticula formation.

One thoracic drain was placed along the mediastinal pleura over the esophageal reconstruction and the right lung was fully re-expanded.

POSTOPERATIVE CARE

The nasogastric tube was removed 24 h later and on postoperative day 3, fluids were started and normal diet was resumed soon thereafter. The chest drain was removed on postoperative day 4. The patient was discharged home on postoperative day 5, in an excellent condition.

DISCUSSION

Although chest pain, cough, dyspnea, dysphagia, hemoptysis, infection, or other nonspecific symptoms may lead to diagnosis, many mediastinal bronchogenic cysts are encountered incidentally during routine chest roentgenogram for other reasons. Thus a considerable proportion of asymptomatic cysts will remain undetected and the true incidence of this rare anomaly and the significance of nonspecific clinical symptoms are elusive. However, once the condition is diagnosed surgical excision is frequently indicated, either to relieve clinical symptoms or to prevent possible complications.[23] Complications include infection, hemoptysis, trachea or superior vena cava compression, intracystic haemorrhage, rupture, bronchial fistula, pneumothorax, and malignant changes, which have all been reported.[4]

Mediastinal bronchogenic cysts are usually unilocular, rarely multilocular. Their wall is represented by a ciliated columnar epithelium lining, cartilage structure and occasionally may contain a mucinoid filling.

The diagnosis is made radiologically, beginning with barium esophagogram. Chest computed tomography (CT) can provide valuable data for surgical planning, i.e. anatomical location of the tumor and its relationship to other organs in the chest. Endoscopy and endoscopic ultrasound (EUS) may also aid in diagnosis. Endoscopy will reveal a submucosal lesion and EUS will show benign ultrasonographic characteristics. Biopsy is generally not recommended, since the bleeding and trauma associated can cause mucosal adhesions, which complicate the resection and increase the possibility of mucosal rupture. Moreover, biopsies will only reveal overlying mucosal tissue on pathological examination.

Treatment of mediastinal bronchogenic cysts, particularly for asymptomatic patients, remains controversial. Some authors recommend surgical resection when symptoms exist or when a malignant cyst is suspected.[5] For others, excision is advocated in all cases to confirm the diagnosis and prevent complications. Standard surgical treatment consists of excision by thoracotomy. Percutaneous or transbronchial aspirations, injection of sclerosing agents, and excision via mediastinoscopy have also been reported.[6] Video-assisted thoracic surgery (VATS) gradually became the first option. However, the presence of bronchogenic mediastinal cysts with major adhesion to vital structures has been considered as an unfavorable condition for VATS treatment.[7]

Reviewing the English literature, several cases of mediastinal lesions which were resected thoracoscopically came to light. In a multicenter study by Demmy et al., the main conclusion was that VATS is a safe technique for benign mediastinal tumors, typically those in the middle and posterior mediastinum.[8] Other authors came to the same conclusion, while they tried to establish some of the first indications. Kitami et al., reported that VATS is an effective and reliable approach for managing mediastinal diseases. Cases of small lesions surrounded by thymic tissue, cystic lesions excluding lymphatic duct origin, and neurogenic tumors without evidence of intraspinal invasion are good indications for VATS.[9] Finally, with experience and use of appropriate instrumentation, resection of bulky intrathoracic lesions by VATS is feasible and safe. It should be considered as a reliable alternate for tumors that are benign and most often asymptomatic.[1011]