Ventilation Strategies in a Pediatric Patient Undergoing Resection and Anastomosis for a Juxta Carinal Tumor

ABSTRACT

Tumors close to the carina pose a unique challenge to the Anesthesiologist in terms of lung isolation and ventilation strategies. We present the case of a 15-year-old patient who was diagnosed with a myofibroblastic tumor in the left main bronchus and carina, posted for a robotic assisted sleeve resection and anastomosis. The surgical approach was from the right side. Hence, the traditional strategies for right lung ventilation could not be employed. A combination of endobronchial intubation, jet ventilation via airway exchange catheter (AEC) and cross field ventilation enabled us to complete the procedure successfully.

INTRODUCTION

Maintaining intraoperative oxygenation and ventilation is an important task in tracheobronchial surgeries.[1] These surgeries were performed under extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass (CPB).[2] There are case reports in adults describing cross field ventilation as an alternate option,[3] but not in pediatric patients.

We report the anesthetic management of a pediatric patient who underwent robotic-assisted thoracoscopic carinal and left main stem bronchus sleeve resection and anastomosis. A written consent was obtained from the parent of the patient for publication. Our institution does not require an ethics committee approval for case reports.

CASE REPORT

A 15-year-old girl presented with persistent respiratory infections despite treatment with inhalational bronchodilators and steroids. On further evaluation, a computerized tomography (CT) scan of the thorax revealed a solid lesion measuring 6.8 mm × 7.3 mm × 8.2 mm involving the distal trachea above the carina, extending into the left main bronchus and causing airway narrowing [Figure 1a and b]. She underwent rigid bronchoscopy and debulking of the tumor one week prior to the surgical procedure [Figure 1c]. She was scheduled to undergo robotic-assisted thoracoscopic sleeve resection and anastomosis of carina and left main stem bronchus.

Figure 1.

Preoperative imaging and bronchoscopy findings; (a) CT image of the tumor at left tracheobronchial angle entering the left proximal bronchus as denoted by the arrow mark; (b) Bronchoscopic image of the tumor prior to de-bulking. Tumor obstructing the left main bronchus at the carinal level is marked with the arrow; (c) Bronchoscopic image of the tumor post de-bulking

General anesthesia was induced with propofol, fentanyl and neuromuscular blockade was provided with atracurium. Airway was secured with a size 3 laryngeal mask airway (LMA). Intra-arterial cannulation and central venous access were established following which an epidural catheter was placed at T8–T9 intervertebral level.

The surgical access to the carina and left main stem bronchus was planned through the right hemithorax as this approach provided more working space for the operating team. Hence, right lung isolation was planned. The LMA was removed. She was intubated with a 5.5 mm internal diameter (ID) wire reinforced flexometallic tube (FMT) which was advanced endobronchially into the left mainstem bronchus under fibreoptic (FOB) guidance to initiate one-lung ventilation (OLV) on the left. After confirming lung isolation on the right side clinically, the patient was positioned in left lateral position and padding of all bony prominences was done.

The patient was maintained on sevoflurane anesthesia with atracurium boluses as required, to ensure adequate muscle relaxation. During resection of the carina and proximal left main bronchus, an airway exchange catheter (AEC) 14Fr was inserted through the FMT. The FMT was withdrawn into the trachea and fixed at the lips. A manual jet ventilator was used to continue ventilation of the left lung through the AEC. Inhalational anesthesia with sevoflurane was discontinued and total intravenous anesthesia (TIVA) was initiated with propofol infusion. Ventilation through AEC was done during the resection phase since the diameter of the AEC is less and it was easier to respect the walls of the trachea and bronchus with AEC in place. The resected specimen was sent for histopathology examination to check if the margins were free of tumor, prior to starting anastomosis. While waiting for the biopsy report, cross-field ventilation was initiated with another 5.5 mm ID cuffed sterile FMT inserted through a separate thoracoscopic port [Figure 2 and 3a]. This tube was placed across the surgical field under vision by the surgeon into the distal end of the left bronchus to ensure adequate oxygenation and ventilation. Cross field ventilation was employed to ventilate the left lung better and provide oxygenation with less airway resistance as compared to the AEC. Once the histopathology report suggested that the margin was free of tumor, decision was to proceed with anastomosis. To facilitate anastomosis and to ensure ventilation, the AEC was reinserted and the cross field FMT was removed [Figure 3b].

Figure 2.

Diagrammatic representation of the different ventilation methods employed

Figure 3.

Cross field ventilation; (a) Cross field ventilation using flexometallic tube; (b) Cross field flexometallic tube was withdrawn and ventilation maintained by jet ventilation through airway exchange catheter during carinal anastomosis

After the end-to-end tracheobronchial anastomosis was completed, AEC was removed and ventilation resumed with the FMT which was kept in the trachea. The patient was turned supine following completion of the surgery and the anastomotic site was visualized with the FOB to check for airway patency. A saline lavage was given through the FOB and blood and secretions were suctioned out bilaterally. The surgical duration was 5 h and the estimated blood loss was 100 ml. The patient was hemodynamically stable and was extubated fully awake. She was shifted to the Pediatric Intensive Care Unit for postoperative monitoring. She was ambulated on postoperative day 3 and discharged on day 5.

DISCUSSION

In this case report we have demonstrated that, the meticulous planning and the execution of multiple types of ventilation strategies in a pediatric patient undergoing robotic assisted carinal resection surgery, can avert the need for cardiopulmonary bypass or veno-venous extra-corporeal membrane oxygenation for the same.

Robotic-assisted thoracic surgeries challenge the anesthesiologist in terms of difficulty in accessing the patient due to the bulky robot, hemodynamic and respiratory effects of carbon dioxide (CO₂) insufflation and the need for OLV.[4] In addition, maintaining intraoperative oxygenation and ventilation is a major task in tracheobronchial surgeries. ECMO or CPB are instituted during complex procedures involving dissection close to the mediastinal vessels or retraction of heart. Complications of ECMO or CPB include bleeding, stroke and hemolysis.[5,6]

Dissection of the walls of trachea or bronchus may be difficult around a larger-sized conventional endotracheal tube (ETT). For short time periods like during resection and reconstruction of trachea and carina, ETT can be replaced by a smaller diameter catheter through which high frequency jet ventilation can be used. This helps with oxygenation but is not suitable for CO₂ elimination if used for longer periods. In addition to hypercarbia, inappropriate settings can result in hypoxia and high airway pressures can cause barotrauma.[6] Cross table ventilation has been described in literature for adult patients.[7] This involves retraction of the tracheal tube and direct intubation of the distal bronchus across the sterile surgical field. Complications like desaturation, bradycardia, and arrhythmias have been reported.[8]

The goals of anesthesia in our patient were to provide control of the airway, maintain oxygenation and ventilation, and ensure good surgical exposure of the trachea by providing lung isolation during airway surgery. Since the surgeon required the right lung to be collapsed during the surgery, we planned a left endobronchial intubation. Once the carina and the left main bronchus were exposed and the surgeon was ready to respect the tumor, the ETT had to be changed to a smaller airway catheter to facilitate the resection. Following resection of the tumor, we discontinued the jet ventilation through AEC since oxygenation and ventilation is better with a larger size ETT. So, we used the cross-field ventilation technique with an ETT inserted through one of the right robotic ports. Cross field ventilation helped with oxygenation and CO₂ elimination during the time period when we had to wait for the histopathology report. Once the anastomosis started, jet ventilation was resumed through the AEC again.

We faced few challenges during the airway management. Apart from the restricted patient access, the oxygen saturation was around 85–92% when ventilation through AEC was difficult. Hypoxia led to few transient episodes of bradycardia; the lowest heart rate recorded was 30/min that responded to intravenous atropine.

A tailored combination of ventilation strategies in a pediatric patient undergoing robotic assisted carinal resection surgery, can avert the need for CPB or ECMO. Potential pitfalls of using these techniques like hypercarbia, barotrauma, and hypoxia were identified, and strategies to manage them were in place.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.