Unique mishap following transfacial pin fixated midface distraction and successful management using nasal endoscopy

Abstract

A 2-year-old female child with craniosynostosis was referred to our unit for definitive management. She presented with a turricephalic head, hypoplastic midface and obstructive sleep apnoea. Routine preoperative workup included radiographs, CT and polysomnography. She was provisionally planned for calvarial remodelling and midface advancement using transfacial pin fixated distractor (TPF). This involves insertion of a K-wire from one zygoma to the other, a few millimetres below the orbits, traversing across maxilla and nasal cavity. The ends of K-wire are then connected to the distractor anchored firmly to the temporal bone. During insertion, the K-wire transected the nasogastric tube. This technical disaster was circumvented by endoscopic-guided disengagement prior to recovery. The purpose of this paper is to discuss the probable causes that lead to such untoward instances and strategies to avoid and manage the same.

Background

Craniosynostosis involves premature fusion of one or more calvarial sutures in the child, leading to restricted cranial growth which in-turn restricts the mid-facial growth. Genetic studies reveal polygenic mutations especially FGFR (fibroblast growth factor receptor), TWIST (twist family bHLH transcription factor 1) genes which lead to poly sutural synostosis. Surgical treatment is primarily aimed at two issues namely, prevention of cerebral damage secondary to raised intracranial pressure and morphological correction of mid facial retrusion that could obstruct the airways in addition to exorbitism and ocular damage.¹

Correction of midface retrusion requires large advancements which are better achieved using distraction osteogenesis. The process involves osteotomy at the planned level and fixation of a distractor device. Following a latency period of 2–7 days, the device is activated at a predetermined rhythm which results in incremental advancement of the midface usually at the rate of 1 mm/day. Surgeons are spoilt for choice in terms of devices available and we prefer the transfacial pin fixated distractor (TPF), which is done under general anaesthesia (oro endotracheal intubation) under multiparametric monitoring (Vitals, Temperature probe; nasogastric tube in place). This is often based on the clinical acumen of the surgeon with minimal guidance that can be obtained with intraoperative C-arm.^{2 3} Rarely, the K-wire may transect nasal tubes (Ryle's Tube (RT)) instead of sliding over and by-passing it, leading to unwarranted sequel that necessitate a prompt action. The primary objective of this paper is to describe one such scenario that was managed immediately with C-arm and endoscopic guidance.

Case presentation

A 2-year-old female child with craniosynostosis and midface retrusion was referred to our centre with laboured breathing especially during sleep. She underwent calvarial remodelling at 12 months of age and given options of tracheostomy or early midface advancement but parents refused both options. The child would only sleep at a 45° angulation cuddled by the parent as this eased her airway. There was no relevant social or family history. She presented with a turricephalic (tower-shaped skull secondary to multisutural synostosis) head and retruded midface. Routine preoperative workup was performed including skull X-rays, fundoscopy and polysomnography which confirmed obstructive sleep apnoea. She was provisionally planned for midface distraction advancement using TPF technique. General anaesthesia was administered and as a routine, the transnasal RT and temperature monitoring probe were secured using tapes. Transfacial pin was inserted from the body of one zygoma to the other, maintaining safe distance from the orbits. This was monitored using C-arm imaging (figure 1). At the end of the procedure, while preparing for extubation, an unusual tug was elicited with the RT in the nasal cavity (video 1). An unfavourable penetrative engagement of the tube to the transfacial pin was suspected (figure 2), which was later confirmed using C-arm imaging and nasal endoscopy (figure 3). The exact zone of engagement was identified and the RT was divided precisely, using a no:11 BP blade under transnasal endoscopic guidance (video 2 and figure 4). A new nasogastric tube was inserted while the child remained anaesthetised, although with difficulty and secured using tapes Following this, the child was comfortably extubated and shifted to postanaesthetic care unit (PACU) for monitoring. The recovery was uneventful and distraction was performed as per standard protocol.

Figure 1.

C-arm imaging.

Video 1.

Download video file ^{(3.7MB, mp4)}

DOI: 10.1136/bcr-2019-230940.video01

Figure 2.

Before removal of Ryle’s tube.

Figure 3.

Nasal endoscopy confirming penetrative engagement of the Ryle’s tube.

Video 2.

Download video file ^{(1.9MB, mp4)}

DOI: 10.1136/bcr-2019-230940.video02

Figure 4.

The child after removal of Ryle’s tube.

Investigations

Preoperative investigations included routine skull X-rays, fundoscopy to evaluate elevation in intracranial pressure and polysomnography to confirm obstructive sleep apnoea. As a routine, intraoperative C-arm guidance was utilised to facilitate safe insertion of the transfacial pin. At the time of extubation when the Ryles’ tube was suspected to be engaging the pin, a transnasal endoscope was introduced and the image confirmed the complication.

Outcome and follow-up

The patient has been in follow-up for the last 4 months with no events related to this particular intraoperative complication. She is currently on her consolidation phase as a part of routine distraction protocol. She has been planned for distractor removal in 2 months.

Discussion

Elevated intracranial pressure and airway compromise are highly probable consequences of craniosynostosis apart from the compromised facial aesthetics. Routine workup in these patients should be accompanied by evaluation for episodes of hypoxemia and sleep apneas to determine treatment modalities. In the recent era, high-level midface distraction has gained popularity as it corrects the midface and its associated sleep apnea negating the need of tracheostomy. Earlier midfacial distraction also aids in earlier decannulation in patients with tracheostomy. Timing of midface advancement varies for each individual depending on the magnitude of deformity, along with its cosmetic and functional sequelae.¹

Among the wide variety of distraction techniques available, the authors prefer the transfacial pin fixated type which was originally described by Pellerin et al.² We find the construct to be robust and offering good control of the midface segment helping in successful distraction. Additionally, the device assembly is much simpler making distractor removal surgery less cumbersome.

Although simpler than other midface distraction methods, the TPF does present with complications that could be specific to this technique.^{3 4} Sphenopetrous luxation has been quoted in a few cases, probably due to stretching of the cavernous sinus. This had resulted in transient oculomotor paresis which was reversed by stoppage of distraction earlier than planned. Device dissembling is quite possible with any device involved in distraction, more so with external distractors.

Squamopetrous distraction has been described as a serious complication and the reason for this pattern remains difficult to understand, but as expected, premature abandoning of distraction rectified the problem to a certain extent.

Transection of intranasal endotracheal tube during maxillofacial procedures is one of the complications that has been reported in literature. Such mishaps are life-threatening and need to be addressed immediately using fibre-optic bronchoscope/tube exchanger and so on.^5–7 However, perforation of the nasogastric tube has never been reported to the best of our literature search. This could primarily be due to the fact that nasogastric tubes are usually placed at the postoperative phase in the Intensive Care Unit (ICU) or wards. The scenario is quite different for a paediatric craniofacial patient, especially the one who has a transfacial pin traversing across their already hypoplastic nasal cavity. We do realise that hypoplastic nasal cavities allow the transfacial pin to slide along a nasogastric tube in situ but not the other way round. Placing the RT after extubation in the PACU or ward was an option that our team was not willing to avail, considering the fact that very young children are difficult to deal with, in this regard, when they are awake. This is the reason our patients have nasogastric tubes inserted under anaesthesia before commencement of surgery.

Analysing the mid facial anatomy in patients with craniostenosis gives a cue for the incidence of such mishaps. The midface in these paediatric patients is retrognathic with associated nasomaxillary hypoplasia. This condition considerably reduces the space available in the nasal (inferior meatus) / paranasal regions paving way to the incidence of such unwarranted mishaps. The novelty of the technique is one of the primary reasons that not much literature is available assessing its complications.

Penetrative engagement of the K-wire to a RT was an intraoperative mishap that we recognised moments before extubation, when the anaesthetist perceived an unusually resistant tug of the tube. Our reaction, immediately after identifying the complication was to ascertain the exact geometry of engagement, which was done using C-arm imaging and nasal endoscopy. Once the position was confirmed, a 11 blade was introduced alongside the endoscope and the tube was severed at the intersection, allowing removal of the RT in two parts. The child was then comfortably extubated as planned and recovered well to undergo postoperative distraction as per protocol.

Distraction involves gradual advancement of the midface at a rate of 1 mm/day, and hence according to the magnitude of deficiency, improvement of obstructive sleep apnoea can be visible as soon as the desired length is achieved, usually in about a week. Surgeons still try to over-correct the deformity anticipating some relapse.

To conclude, penetrative engagement of a K-wire with the nasogastric tube has never been reported so far and requires documentation to avoid future occurrence. Retrieval of tethered nasogastric tube is essential without disrupting the TPS assembly and to achieve this endoscopy seems to be the only reasonable option.

Learning points.

• Transfacial K-wire insertion carries with it a risk of penetrative engagement with any transnasal tube or probe.

• The surgeons could consider insertion of Ryle’s tube after K-wire just before extubation but it is unpredictable since one cannot be sure of the positioning of K-wire and the amount of space it has occupied being almost a blind procedure.

• When confronted with such a situation, it is always prudent to select the safest option without compromising on the results, in the interest of the patient.