Robotic excision of paraesophageal bronchogenic cyst in a 9-year-old child.

Bronchogenic cysts are often asymptomatic and discovered as an incidental finding. They may become symptomatic due to esophageal compression as they increase in size or from development of infection. We report a case of a 9-year-old male with an asymptomatic bronchogenic cyst who underwent successful robotic assisted thoracoscopic excision.

INTRODUCTION

Majority of the bronchogenic cysts are often asymptomatic and are usually discovered as an incidental finding. They may become symptomatic due to pressure on the surrounding structures such as trachea and esophagus, as they increase in size or develop infection. We report the case of a 9-year-old male with a paraesophageal bronchogenic cyst who underwent successful robotic assisted thoracoscopic excision. To the best of our knowledge, this is the first report of use of the da Vinci Surgical System (Intuitive Surgical, Sunnyvale CA) for thoracoscopic excision of bronchogenic cyst in the pediatric age group from India.

CASE REPORT

A 9-year-old boy was detected to have a retrocardiac mass lesion on the left side, which was detected incidentally on a chest X-ray done for fever. The child had no history of stridor, dysphagia, hemoptysis, or chest pain. His examination revealed no abnormalities, and the laboratory work up was within normal limits at the time of presentation.

Computed tomography (CT) scan of the chest [Figure 1] revealed a well-circumscribed unilocular and homogenous cyst in the left chest measuring approximately 4.6 cm × 3.4 cm directly adjacent to the esophagus just above the hiatus. No air fluid level or mediastinal adenopathy. An upper gastrointestinal endoscopy was normal. With these findings, the diagnosis of either an esophageal duplication cyst or bronchogenic cyst was kept in mind. A robotic assisted thoracoscopic approach was utilized to remove the lesion.

Figure 1

Computed tomographic scan image of the paraesophageal bronchogenic cyst

Operative details

General anesthesia with 26 Fr left sided double lumen endobronchial tube was used. We prefer the placement of a double lumen endobrochial tube wherever feasible. A uninvent tube with a bronchial blocker may be used as an alternative. However, it results in a slow collapse of the lung. Only as a last resort a normal endotracheal tube may be inserted into the right bronchus to achieve a left sided collapse. However, it sometimes leads to ineffective right upper lobe ventilation due to blockade of right upper lobe bronchus and may lead to hypoxia during the surgery. We do not routinely advocate the use of central line and arterial line for intraoperative monitoring.

The patient was placed in a semi-prone position with left side up. Three ports were placed triangulating toward the target anatomy. One 12 mm port was used for the robotic camera and two 8 mm ports were used for robotic arm one and two. A 5 mm port was placed between the camera and arm two, to be used as an assistant port. The cyst was seen in the retrocardiac area overlying the posterior pericardium with its medial aspect applied closely to esophagus for a short segment. The left lower lobe was moderately adherent to the cyst and was freed using bipolar cautery [Figure 2]. All around mobilization was done and a complete excision of the cyst was achieved. The ports were closed with a single chest tube. The overall operating time was 120 min with actual console time of 60 min. The chest tube was removed on postoperative day 1. And the patient discharged the following day. He was seen at follow-up 2 weeks and then 3 months after surgery which revealed a normal chest X-ray with no symptoms. Final pathology revealed a bronchogenic cyst without signs of malignant degeneration or infection.

Figure 2

Intra-operative view of the cyst

DISCUSSION

Mediastinal primary cysts represent 15-20% of all primary mediastinal masses.[12] Bronchogenic cysts comprise approximately 6% of all mediastinal masses in children, while foregut cysts as a group account for 15%.[3] They have been found to account for 18% of all mediastinal tumors in adults.[4] Bronchogenic cysts are embryological remnants that are isolated from the normal development of the foregut. They are lined by respiratory epithelium and their capsule contains cartilage, smooth muscle, and mucous gland tissue. Common locations are near carina (52%) and in the paratracheal region (19%).[5] Air within the cyst is suggestive of secondary infection and communication with the tracheobronchial tree.

Approximately, 40% of bronchogenic cysts are symptomatic, resulting in cough, dyspnea or chest pain[6] while most others are detected incidentally. The treatment is excision because continued growth may lead to compression of surrounding structures. There is also the risk of rare but reported possibility of malignant degeneration.[7] Differential diagnosis is difficult with several entities including congenital cystic adenomatoid malformations, esophageal duplication, neurenteric cyst, pericardial cysts, and lymphangioma. Duplication cysts are detected adjacent to or within the esophageal wall and are indistinguishable from bronchogenic cysts on CT and magnetic resonance imaging. Mediastinal neuroenteric cysts are associated with multiple vertebral anomalies and with neurofibromatosis. Pericardial cysts on the other hand are unilocular and commonly located in the right cardiophrenic space. However, they may occur anywhere in relation to the pericardium.

Traditionally, open thoracotomy has been the method of choice for bronchogenic cysts excision. In children however, it may lead to scoliosis and has a lot of morbidity.[8] Video-assisted thoracoscopic surgery (VATS) may be considered as an alternative to thoracotomy to prevent scoliosis, although no study demonstrated this finding yet. Several reports claim that VATS is superior to the open approach with low complication rates and shorter postoperative hospital stay[9] but are not enough to demonstrate VATS as the first line tool for bronchogenic cyst resections in pediatric patients, especially in those who are in the first decade of their life.[910] Bronchogenic cysts are usually adherent to adjacent structures, which makes a complete resection by conventional thoracoscopy difficult. The three-dimensional visualization and endo-wristed instruments offering greater maneuverability may prove robotic system to be ideally suited for resection of mediastinal cysts without the morbidity of a thoracotomy. In terms of cosmesis however Robotic offers minimal or no advantage over VATS.

Toker et al.,[11] reported their experience with robotic assisted excision of a sub-carinal bronchogenic cyst. They concluded the da Vinci Surgical System for such indications, especially for patients who are in the first decade of their life, may provide higher technical capabilities in a smaller room when compared with VATS. We believe that anything that can be approached by VATS can be better addressed using robotic assistance due to improved visualization and better maneuverability of instruments.

The major limitation in using robotic assistance in pediatric thoracic surgery is the size of robotic instruments in relation to the patient's size. Moreover the narrow intercostal spaces in pediatric age group make it difficult and traumatic to place 8 mm or 12 mm ports for robotic instruments and camera respectively. However, a range of 5 mm robotic instruments and even an 8 mm telescope are available for pediatric cases. In this particular case, we believe that the robotic approach gave us a lot more confidence because of the extended dexterity offered by the articulating robotic instruments leading to a more efficient utilization of a tight space in the retrocardiac area where long rigid nonarticulated VATS instruments would have been more tedious. The loss of tactile feedback when using the robotic system is another major concern. However, till date, we have not encountered any injuries or complications as a direct result of lack of haptic feedback.

The most important limitation of the use of robotic system is the cost involved. There is an initial cost of approximately 1.5-2.0 million dollars for purchasing the robot. There is also a recurring cost of instruments, drapes, and annual maintenance. In our hospital, the initial cost has been absorbed by the hospital and only the cost of consumables is transferred to the patients.

CONCLUSIONS

We strongly believe that robotic assisted thoracoscopic excision of paraesophageal bronchogenic cyst is a safe and effective method to deal with bronchogenic cysts particularly in difficult areas and involves considerably less morbidity than thoracotomy does and may be better suited than VATS for this indication. With more experience in robotic pediatric thoracic surgery its acceptance as a superior alternative to VATS in most cases of bronchogenic cysts will become more widespread.