Pediatric Lung Isolation for Robotic Lobectomy: A Combo Approach for Bronchial Blocker Placement

Abstract

Pediatric one-lung ventilation (OLV) is always challenging for the anesthesiologist. Despite a plethora of options in the present era, there still remains a concern regarding the choice and success of the modality to isolate the lungs in the pediatric age group especially for thoracoscopic procedures. Bronchial blockers provide an effective way to achieve OLV in patients below 6 years. With smaller-sized endotracheal tubes (ETTs) being used in this age group, a physical check of the fit between the equipment (bronchoscope and the blocker inside the ETT) is strongly recommended. In the present case report of a 3.5-year-old child requiring lung isolation for robotic-assisted thoracoscopic surgery, we went a step ahead by using this entire assembly to intubate the patient. This innovative combo approach was chosen considering the anticipated struggle with manoeuvring the two components together. It was quick and safe in terms of decreased airway manipulation of pediatric airway.

INTRODUCTION

Lung isolation in the pediatric population poses a major challenge for an anesthesiologist, especially when the performance of the surgery highly depends on the visual surgical field offered by the successful one-lung ventilation (OLV). We hereby report a case of a 3.5-year-old patient with bronchopulmonary sequestration, posted for lobectomy via robotic-assisted thoracoscopic surgery (RATS), where we were able to achieve OLV by placing a bronchial blocker in a modified way.

CASE REPORT

A 3.5-year-old child, weighing 17 kg, had repeated hospital admissions since birth for recurrent lower respiratory tract infections. He had an antenatal diagnosis of bronchopulmonary dysplasia and was on a regular follow-up. He was asthmatic, on Levosalbutamol and Budesonide nebulization. On examination, the child had asymmetric crying facies, prominent epicanthal folds, anomalous right low-set ear, and a 4-mm ostium secundum atrial septal defect (on transthoracic echocardiography). The CT pulmonary angiogram revealed air trapping in the posterior basal segment of the left lower lobe with the focal air-filled cystic area suggestive of mucocele, secondary to segmental bronchial atresia. Also, a well-circumscribed air-filled lesion measuring 10 × 5 × 12 mm was noted in the subcarinal region [Figure 1]. A minimally invasive RATS procedure was planned to excise the left lower lobe using the Da Vinci Xi robotic system. It was decided to manage the subcarinal lesion conservatively with regular follow-up due to its small size, asymptomatic presentation, and inaccessibility by left thoracoscopy. The parents of the child were counseled about the anesthetic procedure and OLV requirement for robotic lobectomy, and the parental consent was obtained. Regarding the conduct of OLV in the operative room in a pediatric patient with reactive airway, a case conference was done between the anesthesiologist and pediatric surgical team to discuss about the perioperative plan of surgery.

Figure 1.

(a) The CT pulmonary angiogram with an impression of air trapping in the posterior basal segment of the left lower lobe (arrow) secondary to segmental bronchial atresia. (b) A well-circumscribed air-filled lesion (arrow) noted in the subcarinal region

A dry run of complete airway planning was done before hand by the anesthesia team to ensure proper execution on the day of surgery. Considering the age, weight, and airway anatomy of the child, we preoperatively designed an assembly of uncuffed endotracheal tube (ETT) 5.5 mm ID [Figure 2a] already mounted on FOB (Ambu^® aScope^™ 4 RhinoLaryngo Slim) (with a distal tip diameter of 3 mm and a working length of 300 mm), with a 5-Fr Arndt blocker placed in it. Since the FOB was falling short of reaching the ETT tip, the ETT proximal end was cut at 16 cm [Figure 2b]. The beveled end of the ETT was also trimmed accordingly [Figure 2c]. Following this, both the scope and the blocker together protruded just beyond the ETT tip. Since the range of manipulation was restricted, we chose to not couple the guide loop of the blocker with the bronchoscope tip. This whole assembly was kept ready [Figure 2d].

Figure 2.

(a) The uncuffed 5.5 mm ETT, that was cut short from the proximal end (b) – the initial cut segment at 18^th cm mark was insufficient and it was further cut by 2 cm. The distal bevelled end was trimmed (c). The final assembly of ETT, with fiberoptic bronchoscope and bronchial blocker inside, that was introduced after laryngoscopy (d)

The patient was then induced with injection fentanyl 40 µg, midazolam 1 mg, and vecuronium 2 mg, and after ventilating for 3 minutes, laryngoscopy was done. The whole assembly (ETT with FOB and blocker placed within it, but just beyond its tip) was advanced past the vocal cords and further till carina was visualized by Ambuscope in a single attempt. Under the direct bronchoscope guidance, the Arndt blocker was directed in the left mainstem bronchus and balloon placement was clinically confirmed by the conventional auscultation method. The patient maintained 99–100% saturation throughout the airway manoeuvring, and stable hemodynamics and postintubation end tidal carbon dioxide were within normal range.

Invasive lines were then secured (right internal jugular vein, femoral artery) and patient positioned. After insertion of the first robotic port by the open technique, thoracoscopy revealed the left lung to be completely collapsed with adequate intrathoracic space available for manipulation with robotic instruments [Figure 3a]. After insertion of three other robotic ports and two assistant ports, the Da Vinci Xi robotic system was docked on the patient and left lower lobectomy was completed uneventfully. After completion of the procedure, the blocker balloon was deflated and the lungs manually ventilated to check for any leaks. The left upper lobe was seen to re-expand adequately [Figure 3b].

Figure 3.

(a) Thoracoscopic images of deflated left lung (white arrows) during robotic-assisted lobectomy procedure, providing good surgical exposure. (b) The left upper lobe seen to re-expand after completion of the procedure

After successful completion of the surgical procedure, trachea was extubated. The child was then shifted to PACU and discharged on postoperative day 3.

DISCUSSION

With widespread interest in minimally invasive surgical interventions due to improved clinical outcomes, the scope of robotic-assisted surgeries is expanding in the field of pediatric surgery. Despite the existing technical challenges, size constraints, and the limited availability of pediatric-appropriate instruments,[1] the RATS in infants and children is gradually gaining momentum. Indication for the majority of the pediatric RATS includes lung resection like lobectomy or segmentectomy (25.5%),[2] and the success of these procedures depends on reliable OLV for improved surgical exposure as in video-assisted thoracoscopic surgeries (VATS).[3] OLV can be achieved with mainstem endobronchial intubation using a single lumen tracheal tube, bronchial blockers, or double-lumen tubes (DLTs) depending on the patient’s age and weight.[1] However, balloon-tipped bronchial blockers (BBs) remain the ‘technique of choice’ in pediatric patients, under the age of 6 years.[4]

Integrating anatomical knowledge, sizing, and modification of available equipment and innovation helps provide a safe approach to providing one-lung ventilation for pediatric patients.[5] Navigating our options for lung isolation based on recommendations, availability, and familiarity, we chose a 5-Fr Arndt blocker in our case. The other specific balloon-tipped bronchial blocker, EZ-blocker, is approved by FDA but only in adults.[6] Moreover, with its distal end anchoring onto carina, it carried the risk of rupture of the air-filled lesion at the subcarinal region in our patient.

To address our basic concern of being able to accommodate the FOB and BB together in the ETT, a physical check of the fit between the equipment (ETT, FOB, and BB) was done before hand. The general recommendations for predicting the fit of FOB inside the ETT as per recent literature are mentioned below [Table 1].[7,8,9] The dimensions of the equipment we used were an FOB with a 3 mm OD working channel and 5 Fr OD BB (OD = 1.67 mm). The decision to use an uncuffed ETT was taken in favor of its wider internal diameter which provided more working space to accommodate both the bronchoscope and the bronchial blocker with lesser friction. The ETT was cut short, and the bevelled end was trimmed to prevent any inadvertent injury to the subcarinal cyst and also allowing better BB manoeuvrability. However, in our case, the (OD_{B + BB})/(ID_TT) ≈ 0.85 implied that the (FOB + BB) assembly will physically fit inside the ETT, but no adequate ventilation will be able to occur.

Table 1.

General recommendations for selecting bronchoscope sizes relative to endotracheal tube

Size of FOB relative to ETT	Ratio	Predicted fit or ventilation feasibility
OD of the FOB (ODB)/ID of the ETT (IDTT)	<0.9	For adequate fit of FOB in ETT
CSA of the FOB (CSAB)/CSA of ETT lumen (CSATT)	<0.5	To allow some ventilation during the time of bronchoscopy
OD of the FOB (ODB)/ID of the ETT (IDTT)	<0.7

OD=Outer Diameter, ID=Inner Diameter, FOB=Fiberoptic Bronchoscope, ETT=Endotracheal tube

After confirmation, we used the combo approach (whole assembly preloaded in the ETT) for intubation in this case to shorten the apnoea time in our asthmatic patient and minimize the airway manipulation. The blocker was successfully placed in the first attempt with ease and the precise time taken with this approach was observed to be less than the conventional method, although the exact comparison of the time taken was not made. Fiberoptic bronchoscope-guided intubation ensured minimum injury and accurate placement of ETT away from the subcarinal lesion. Surgical intervention for the small, asymptomatic, and uncomplicated subcarinal air cyst was not indicated, and a routine follow-up was planned.[10]

This modification in the practice of inserting ETT, mounted on FOB with the bronchial blocker in situ, can hold immense value in sick pediatric patients who are at high risk of desaturation during apnoeic periods[8] and in patients with subcarinal lesions. Such a technical modification has not been reported in the pediatric age group in the best of our literature search. Although it proved effective during both planning and execution, we recommend that such innovations undergo thorough testing prior to real-time application. Future case series are warranted to evaluate the proposed modifications and draw definitive conclusions regarding their comparative efficacy. Further, to avoid the risk of airway injury as a result of trimmed distal end of ETT, we recommend bronchoscopic-guided intubation or advanced imaging to better understand the lesion’s location and relationship to the airway.

Successful lung isolation is the major determinant for successful VATS/RATS procedure but is still evolving in pediatric patients. Considering the anticipated difficulty with manoeuvring the bronchoscope and blocker together in the ETT, we advocate confirming their physical fit prior to induction and then using the entire assembly for intubation. This creative combo technique ensures successful blocker placement with minimum impairment of intraoperative ventilation.

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.