Robotic Approach to Patent Ductus Arteriosus or Vascular Rings

After general anesthesia and single-lumen endotracheal intubation with a bronchial blocker in the left mainstem brochus, the patient is positioned in a right lateral decubitus position (15 to 20°, slightly prone) to allow easier retraction of the left lung and better visualization of the surgical field. The left lung is retracted with an endoscopic fan retractor. It is important to retract the left upper lobe and the superior segment of the left lower lobe. Routine monitoring includes transcutaneous oxygen saturation, continuous end-tidal carbon dioxide, blood pressure, and an electrocardiogram. The robotic surgical cart is positioned at the cranial end of the operating table, angled 30° to the patient’s left side. The operating surgeon then sits at the master console, and, after surveying the anatomy, typically begins the dissection using Debakey forceps as a left instrument and an electrocautery spatula as a right instrument. It helps to have a first assistant with robotic experience.

(A) Three thoracoscopic trocars are placed in the left hemithorax to accommodate the camera and the two robotic manipulators. The left and right instrument ports are placed in the third intercostal space along the anterior axillary line and in the posterior sixth intercostal space behind the scapula, respectively. The camera port is placed in the fifth intercostal space. (B) An additional small utility incision is placed between the left instrument and camera incisions to allow insertion of an endoscopic lung fan retractor. After thoracoscopic verification of the anatomy, the 30° camera is attached to the robotic cart, and the robotic surgical instruments are placed through the left and right trocars. In smaller children, because of the short distance between ports and the dissection area, free motion of the instrument heads can be restricted. This can be compensated for by moving the anterior and posterior instrument ports caudally by 3 to 4 cm. This allows for passage of a longer portion of instrument shaft inside the thoracic cavity, thus freeing up the entire instrument tip. The proximal joint (“micro-wrist”) can be simply kept bent at 90°, resulting in the same instrument head orientation as if coming in from a port located just above the dissection area.

(A) The mediastinal pleura over the base of the left subclavian artery is opened first, leading to exposure of the other components of the vascular ring. The vagus nerve should be visualized before dissection, and the presumed course of the recurrent laryngeal nerve should also be kept in mind. (B) In cases of double aortic arch with an atretic left arch, both the ligamentum and the distal atretic left arch should be dissected out and divided. ao. = aorta; L = left; LA = left atrium; LCCA = left common carotid artery; LSCA = left subclavian artery; RCCA = right common carotid artery; RSCA = right subclavian artery; v. = vein.

(A) A hemi-azygous vein frequently courses over the dissection site. This can be electrocauterized and divided, or clipped and divided. (B) Circumferential and wide dissection of the ligamentum is essential to ensure complete retraction of the ring components after division.

Once the dissection is completed, an endoscopic clip is applied on each side (A) and the ring is divided sharply with scissors or with electrocautery (B).

Once the ring is divided, both ends should retract briskly, and the esophagus should be visible underneath. If additional fibrous strands are crossing the esophagus, they should also be divided.

In cases where a prominent diverticulum is present and might lead to recurrent symptoms, the diverticulum can be robotically tacked to the posterior spine periostium using 4-0 Gore-Tex (W.L. Gore, Inc., Flagstaff, AZ) sutures.