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Thoracoscopy 1166.e1

Thoracoscopy
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• Basic surgical supplies (towels, drapes, towel
Difficulty level: ♦♦♦
clamps, bowl, sterile saline, suction tubing) overinsufflation causing inadequate oxygen
saturation/hypoxemia).
Synonyms • Basic surgical instruments (#12 scalpel blade, Pericardial window:
Thoroscopy, video-assisted minimally invasive Brown-Adson forceps, needle holders) • The long (≥ 15 cm) trocar is introduced
thoracic surgery • Suture (3-0 absorbable monofilament suture, through an approximately 8-mm stab inci-
2-0 nonabsorbable monofilament suture) sion through the skin and subcutaneous
Overview and Goals Anesthesia: tissues approximately 5 cm caudal and to
• Endoscopic exploration, biopsy, and surgical • Premedication with opioid (e.g., fentanyl) the left of the xiphoid process. The trocar
procedures of the thorax (pericardial window, and benzodiazepine (e.g., midazolam is introduced at a downward angle (i.e.,
vascular ring surgery, patient ductus arte- 0.2-0.4 mg/kg IV or IM); anticholinergic craniodorsally) and then positioned paral-
riosus ligation, thoracic duct ligation, lung agents administered only as needed lel to the abdominal body wall and aimed Procedures and Techniques
lobectomy) • Anesthetic induction with either propofol toward the left shoulder joint. The trocar is
• Thoracoscopy is performed almost exclusively (e.g., 3-6 mg/kg slow IV to effect) or removed and the endoscope placed through
on dogs; size constraints limit visualization etomidate the trocar when the sensation of crossing the
and safe manipulation in patients < 7 kg. • Anesthetic maintenance with oxygen/ diaphragm is felt or at any point to monitor
• Most commonly used for creating a pericar- isoflurane inhalation progress. The trocar is almost fully inserted
dial window, allowing pericardial biopsy and • Anesthetic monitoring including pulse when traversing the diaphragm of large dogs.
alleviating recurrent cardiac tamponade, and oximetry, capnography, blood pressure, and • Two additional instrument ports are placed
for performing pleural biopsies (idiopathic electrocardiographic (ECG) monitoring on the left hemithorax in a triangulated
pleural effusion) orientation, approximately at the eighth ICS
Anticipated Time 5-10 cm below (dorsal to) the costochondral
Indications 30 minutes or more, depending on procedure, junction and the seventh ICS 2-5 cm below
• Recurrent pericardial effusion (p. 773): experience of endoscopic team the costochondral junction. Exact location
common depends on chest conformation and heart
• Idiopathic pleural effusion (p. 791): Preparation: Important size. Before introduction of the trocars, the
occasional Checkpoints selected intercostal locations are palpated
• Idiopathic pneumothorax (p. 797): rarely • The entire ventral and lateral thorax and and visualized internally with the endoscope
done, may be done as adjunctive step for abdomen should be clipped and aseptically to decide if they are suitable, considering
surgical planning for thoracotomy prepared to facilitate quick conversion to heart and lesion location. If so, an 8-cm
• Vascular ring anomaly: done in certain an open thoracotomy or laparotomy in an stab wound is made into the skin to allow
centers emergency setting. placement of a 5-mm endoscopic trocar with
• Patent ductus arteriosus (p. 764): rarely done • Be sure all video equipment is working a closed valve.
• Idiopathic chylothorax (p. 172): done in properly before anesthetizing the patient. • With ports created and instruments in place,
certain centers the heart is visualized, and the forceps (in the
• Primary pulmonary disease: uncommonly Possible Complications and cranial port) and scissors (in the caudal port)
done Common Errors to Avoid are visualized in the thorax. The pericardium
• Biopsy of mediastinal, pulmonary masses: • Main complication is hemothorax. is grasped. This may be difficult in patients
uncommonly done • Inadvertent puncture of intraabdominal or with pericardial effusion at the time of the
intrathoracic structures procedure or in patients with a very thick
Contraindications • Insufficient procedural analgesia results in pericardial sac. The pericardial sac must be
• Clotting hemothorax bucking of the ventilator (voluntary breaths, grasped—not just the fatty layer adjacent to
• Uncorrected bleeding tendencies not coordinated with mechanical ventilation). it—to allow for adequate manipulation. One
• Small patients < 7 kg (approximately) This results in rapid oxygen desaturation. clue is the apex beat of the heart that can be
• The rigid endoscopic telescope should be felt on the forceps when the pericardium, but
Equipment, Anesthesia prewarmed in very warm saline for > 5 not pericardial fat, is contacted. Drainage of
Equipment needs: minutes to avoid fogging of the lens. the pericardial sac with a Veress needle may
• Mechanical respirator (desirable but not allow easier manipulation of the pericardial
absolutely required) Procedure sac if pericardial effusion is present.
• Rigid endoscopic telescope (0°, 5-mm Anesthetic induction and maintenance, dorsal • When the pericardium is grasped, a small
diameter scope) recumbency, aseptic preparation of the whole incision should be made into it, close to the
• Endoscopic camera ventral and lateral thorax, mechanical ventila- tips of the forceps and with the pericardium
• Light source tion. The following describes the procedures tented up and away from the underlying
• Video display using typical (nonselective two-lung ventilation) heart. Care should be taken to not inad-
• Endoscopic trocars (5-mm diameter, one intubation: vertently clip any pulmonary tissue. On
needs to be a minimum of 15 cm long) • A Duke’s trocar is used for inducing pneu- successful entry of the pericardium, fluid is
• 12-Fr, soft suction tubing (to use as chest mothorax and to allow the threading of a released in patients with pericardial effusion.
tube) 12-Fr suction tube into the left approximately The pericardium can then be repositioned
• Endoscopic instruments for basic pericardial 10th intercostal space (ICS) just dorsal to with one jaw of the forceps within the peri-
window or pleural biopsy: 360°, rotatable the mid-left thorax. cardial sac for better control. The goal with
Metzenbaum scissors, Babcock atraumatic • After placing a 3-way stopcock, additional a pericardial window is to make an opening
grasping forceps, cup biopsy instrument room air is introduced into the thorax approximately 4-5 cm in diameter for a
• Cautery (administered by the endoscopic (≈10-20 mL/kg) to create a space in which large-breed dog. This results from a small
instruments) to work, being mindful of excess (e.g., incision in a normal elastic pericardium or a

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