(1)
Department of Paediatric Surgery, Birmingham Children’s Hospital, Birmingham, UK
(2)
Department of Paediatric Surgery, Birmingham Children’s Hospital NHS Foundation, Birmingham, UK
Abstract
Thymectomy in children is performed most commonly for autoimmune myasthenia gravis. Although there are no randomized controlled trials, there is evidence to show that selected patients undergoing thymectomy are more likely to improve, become asymptomatic, or achieve medicine-free remission compared with those who do not [1]. Advances in thoracoscopy have allowed this procedure to be carried out with reduced morbidity compared with open thymectomy.
Keywords
ThoracoscopyThymusMyasthenia gravis7.1 General Information
Thymectomy in children is performed most commonly for autoimmune myasthenia gravis. Although there are no randomized controlled trials, there is evidence to show that selected patients undergoing thymectomy are more likely to improve, become asymptomatic, or achieve medicine-free remission compared with those who do not [1]. Advances in thoracoscopy have allowed this procedure to be carried out with reduced morbidity compared with open thymectomy.
7.2 Relevant Anatomy
The thymus sits in the anterior mediastinum. It has two upper poles that extend into the neck and lower poles that drape over the pericardium of the heart, connected by a small isthmus in the middle. The thymus receives its arterial supply from the internal mammary artery and/or inferior thyroidal artery. A significant variation in size, shape, and extent exists, and the knowledge of the thymus’s anatomic variations is vitally important for surgery [2]. We therefore recommend a preoperative CT scan with intravenous (IV) contrast before thymectomy (Fig. 7.1).
Fig. 7.1
Preoperative CT scan with IV contrast. The scan is obtained to delineate the thymus and to identify any anomalous blood supply or, rarely, associated thymic pathology. There is no ectopic tissue in this scan
7.3 Working Instruments
30° scope
Three ports (5 mm): one camera port and two working ports
The ultrasonic surgical system is preferred over bipolar electrocoagulation sealing devices
Monopolar diathermy
7.4 Surgical Technique
7.4.1 Port Positioning with Ergonomic Considerations
Single-lung anaesthesia helps but is not absolutely essential. For right thoracoscopy:
The patient is supine with a sandbag under the right hemithorax (Fig. 7.2).
The right arm is abducted to 90°
The camera port is placed in the mid- or posterior axillary line at approximately the fourth or fifth intercostal space.
The two working ports are placed at the anterior axillary line, one at approximately the third intercostal space and the other at approximately the fifth or sixth intercostal space (Fig. 7.3).
Pressures should be 4–6 mmHg and the flow 2 L/min. (If single-lung anaesthesia is used, CO2 insufflation may be stopped once the lung has collapsed on the right side.)
Antibiotics should be given prophylactically and in three doses postoperatively; however, antibiotics thought to exacerbate myasthenia gravis, such as aminoglycosides, quinolones, telithromycin, azithromycin, erythromycin, clindamycin, ampicillin, imipenem, vancomycin, and metronidazole, should be avoided [3].
Dissection is commenced by lifting the inferior pole overlying the pericardium using either the monopolar diathermy hook or scissors to divide the visceral pleura and loose areolar tissue around the thymic capsule (Fig. 7.4).
The posterior surface is dissected off the pericardium gradually with cephalad progression (Fig. 7.5).
The short thymic vein or veins draining into the bracheocephalic vein should be identified next and isolated (Fig. 7.6).
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
