Two case reports of soft palate perforation as a complication of video laryngoscope-assisted tracheal intubation: mechanism analysis and preventative strategies

Abstract

Background

Video laryngoscopes have gradually replaced direct laryngoscopes as an aid for tracheal intubation in various scenarios, increasing intubation success rates and facilitating difficult airway management. Unlike direct laryngoscopy, video laryngoscopy carries specific risks during the intubation process.

Case presentation

We report two cases of soft palate perforation, a rare oropharyngeal complication associated with video laryngoscopy. In the first case, video laryngoscopy was used for teaching endotracheal intubation during otolaryngology nasal bone fracture surgery, and soft palate perforation was detected via video laryngoscopy on the third intubation attempt. In the second case, video laryngoscopy was used for routine tracheal intubation in spinal surgery, and soft palate perforation was identified before extubation at the end of surgery.

Conclusions

Current teaching curricula for video laryngoscopic tracheal intubation focus primarily on glottic visualization, yet emphasis should also be placed on the blind spot of endotracheal tube trajectory within the oral cavity under video laryngoscopy. Warnings regarding injury to oral soft tissues should be incorporated into training exercises.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-026-03683-5.

Introduction

Video laryngoscope-assisted tracheal intubation enhances visualization of the glottis, thereby reducing intubation difficulty [1]. However, due to blind spots in the oropharyngeal pathway traversed by the endotracheal tube, soft palate perforation occasionally occurs [2]. This article reports two cases of soft palate perforation following visualized intubation under Insigters video laryngoscope (with Disposable M-size Laryngoscope Blade for Insight Airway Explorer, Shenzhen Insighters Medical Technology Co., Ltd, China.) and analyzes their causative mechanisms. Novel perspectives on training protocols for this technique are proposed.

Case report 1

A 66-year-old woman was scheduled for closed reduction of nasal fracture. Her medical history was unremarkable. Physical examination revealed a Mallampati class 1 airway.

Anesthesia was induced with standard protocol. Tracheal intubation was attempted using a size 7.0 wire-reinforced endotracheal tube with the Insighters video laryngoscope (Disposable M-size Laryngoscope Blade for Insight Airway Explorer, Shenzhen Insighters Medical Technology Co., Ltd, China.). A Student Registered Nurse Anesthetist (SRNA) performed the first attempt. Despite adequate glottic exposure, the tube tip position was not visualized during insertion. The tube was withdrawn, its curvature adjusted, and reinserted. During the second attempt, the tube tip remained invisible in the laryngoscopic view. The attending anesthesiologist immediately instructed removal of both devices and took over the procedure. During slow reinsertion of the laryngoscope, a 0.5 × 0.5 cm laceration with active bleeding was identified on the soft palate (Fig. 1).

Fig. 1.

A 0.5 × 0.5 cm laceration with active bleeding on the soft palate

The otolaryngologist was immediately consulted. Nasopharyngoscopy reveals a transoral pharyngeal injury, with the wound originating posterior to the glossopalatine arch near the tonsillar fossa, penetrating through the soft palate into the nasopharynx where the posterior choanae are visible. The wound was surgically repaired. The patient reported no discomfort by postoperative day 3 and was discharged uneventfully. One week postoperatively, a follow-up examination in the otolaryngology clinic revealed intact and smooth mucosa on both the anterior and posterior surfaces of the soft palate, as well as intact and smooth mucosa in the nasopharynx under electronic nasopharyngolaryngoscopy (Fig. 2). At the 1-month follow-up, she continued to deny any symptoms.

Fig. 2.

Soft palate anterior surface sutures intact with mucosal healing

Case report 2

A 53-year-old female patient, height 163 cm, weight 81 kg, BMI 30.49 kg/m², ASA physical status II, with hypertension, underwent transforaminal lumbar interbody fusion (TLIF). Physical examination for airway assessment revealed a neck circumference exceeding 42 cm, with no signs of difficult airway indicated by thyromental distance, thyromental height, interincisor distance, or temporomandibular joint mobility. Physical examination revealed a Mallampati class 1 airway.

Standard anesthetic induction was performed. Tracheal intubation was successfully achieved with a 7.0 reinforced tube under video laryngoscope guidance (Insighters video laryngoscope with Disposable M-size Laryngoscope Blade for Insight Airway Explorer, Shenzhen Insighters Medical Technology Co., Ltd, China.), with optimal glottic exposure by the SRNA and smooth tube placement.

The patient was positioned prone for surgery, and the procedure proceeded uneventfully. However, during repositioning for tracheal extubation, the tracheal tube was observed traversing through the superior pole of the right tonsil and soft palate (Fig. 3), after blood stain was found on the tube surface. An immediate intraoperative consultation was requested. The otolaryngologist diagnosed an iatrogenic soft palate perforation caused by the endotracheal tube and recommended urgent suturing. After tube removal, successful reintubation was achieved, and definitive extubation was performed post-repair.

Fig. 3.

A perforation 1 cm right lateral to the palatoglossal arch

Postoperatively, the patient reported a foreign body sensation in the throat but no other special discomfort. The patient was discharged on postoperative day 7. At the one-month follow-up in the ENT (Ear, Nose and Throat) clinic, pseudomembrane was noted over the soft palate at the superior pole of the right tonsil. After removal, a small ulcer was visualized at the site. The patient was advised to maintain a light diet and return if symptoms occurred.

Discussion

Soft palate perforation is a rare complication during tracheal intubation. However, with the widespread adoption of video laryngoscopes, this uncommon adverse event has become increasingly prevalent [3]. Soft palate perforation is a manifestation of palatal injury. To our knowledge, this is the first reported soft palate injury with video laryngoscope of Insighters. After insertion and exposure of the video laryngoscope, the trajectory of the endotracheal tube within the oral cavity remains a visual blind spot. In cases where operators lack sufficient clinical experience, the tip of the endotracheal tube is prone to traumatizing the delicate oral soft tissues.

There are several common contributing factors may lead to soft palate injury.

1. Some patients have an oral cavity narrower than that of the general population, resulting in limited operative space for laryngoscope placement and endotracheal tube manipulation [3]

2. When operators with insufficient clinical experience encounter resistance during tube advancement, persisting in advancing the endotracheal tube can lead to soft palate injury [4, 5]

3. Some video laryngoscopes with distict blade design may predispose this kind of injury (Fig. 4, Table 1) [6]

4. The endotracheal tube’s rigid stylet shapes the catheter and shortens intubation time. Protruding beyond the tip or penetrating side vents, it poses a high risk of soft palate injury [7, 8]

5. A visual blind spot persists during tube adjustment, ultimately resulting in soft palate injury [3, 6, 9]

Fig. 4.

Four commonly used adult laryngoscope blade models from four different manufacturers. (A) Front views of the four laryngoscope blades. (B) Side views of the four laryngoscope blades. a. Mac 3 Curved Laryngoscope Blade, Truphatek International Ltd., Israel. b. TDC-3 Disposable Laryngoscope Blade, Zhejiang Youyi Medical Instrument Co., Ltd, China. c. Disposable M-size Laryngoscope Blade for Insight Airway Explorer, Shenzhen Insighters Medical Technology Co., Ltd, China. d. GVL 3 Stat Disposable Video Laryngoscope Blade, Verathon Inc., USA

Table 1.

Comparative parameters across laryngoscope blade from distinct manufacturers

	Direct laryngoscope a	UE video laryngoscope b	Insighters video laryngoscope c	Glidescope video laryngoscope d
Laryngoscopic blade curvature (°)	42	42	62	60
Insertable length (mm)	105	108	100	80
Width of blade tip (mm)	15	21	20.6	16
Height of blade tip (mm)	13	12.5	13.5	16

^a Mac 3 Curved Laryngoscope Blade, Truphatek International Ltd., Israel

^b TDC-3 Disposable Laryngoscope Blade, Zhejiang Youyi Medical Instrument Co., Ltd, China

^c Disposable M-size Laryngoscope Blade for Insight Airway Explorer, Shenzhen Insighters Medical Technology Co., Ltd, China

^d GVL 3 Stat Disposable Video Laryngoscope Blade, Verathon Inc., USA

Typically, during endotracheal intubation under video laryngoscope guidance, after visualizing glottis exposure on the video display, the endotracheal tube is inserted through one corner of the mouth [10]. Once the tip of the endotracheal tube is visualized on the video laryngoscope screen, the tube is advanced through the glottis into the trachea. However, during this procedure, operators tend to focus their visual attention exclusively on the area around the glottis displayed on the video laryngoscope, overlooking the trajectory of the endotracheal tube within the oral cavity [3].

Compared with video laryngoscopes, classic Macintosh laryngoscope blades offer direct visualization of the endotracheal tube’s entire oral trajectory [11]. They occupy less oral operational space. This may reduce the risk of soft palate injury from tube path blind spots. However, video laryngoscopes improve intubation success rates [11]. They also provide advantages in emergency difficult airway scenarios [12]. Thus, in clinical practice, integrate the full-visualization experience of classic Macintosh blades when using video laryngoscopes for intubation.

Therefore, we propose a concise strategy framework and complementary training protocols for video laryngoscope-assisted endotracheal intubation, targeting the reduction of soft palatal injury.

1. Dual-vision Tube Trajectory Confirmation: After glottic visualization and before tube insertion, concurrently monitor the video laryngoscope screen and directly observe the tube’s oral trajectory until the tube tip is visualized on the monitor [4, 5]

2. Rigid Stylet Standardization: Prohibit stylet protrusion beyond the tube tip or penetration through side vents; retract the stylet immediately after the tube enters the glottis [7, 8]

3. Resistance Response Protocol: Cease tube advancement at unexpected resistance, reassess tube/blade position, and reattempt only after eliminating blind-zone trauma risks

4. Trainee Supervision Thresholds: Achieving a ≥90% manikin intubation [13, 14] success rate without causing soft tissue damage to the manikin may represent an appropriate proficiency threshold for novice tracheal intubation trainees

Traditional intubation training prioritizes anatomical identification and glottic exposure skills [15], with tube manipulation before glottis entry remaining an overlooked domain. Future curricula should integrate direct and video laryngoscopy training, emphasizing that blind zones distal to the blade tip necessitate complementary direct visual guidance for tube advancement. Competency assessments should incorporate dedicated scoring metrics for under-vision tube delivery, with position sensors on simulation manikins to trigger alarms upon oral soft tissue compression. Mandatory manikin training for novices is recommended to solidify these operational key points, thereby translating simulation-based proficiency into reduced soft palatal injury incidence in clinical practice.

Once palatal perforation occurs, an otolaryngologist should be promptly consulted for management. The treatment approach is determined by the size of the wound and the patient’s clinical condition. The intervention measures for such injuries are roughly categorized into five types [3]: “primary repair” (single-layer mucosal suturing), “complex repair” (multilayer closure), “cauterization” (cautery required prior to wound closure), “none” (no intervention needed), and “pharmacological treatment” (patients receive steroids or antibiotics as intervention). 45% of cases require simple primary repair without the need for any long-term follow-up care. Another 27% of patients require no intervention at all, while 5% only need pharmacological treatment [3]. For patients with long-term intubation, surgical intervention should be promptly performed if soft palate injury is detected. Conservative treatments cannot achieve complete healing and may even lead to soft tissue necrosis [16].

Limitation

Notably, this analysis is limited by device heterogeneity and small sample size. The exclusive focus on a single video laryngoscope type restricts generalizability across different video laryngoscope brands/models due to design variations in blade angle, curvature, and camera positioning. Comparative investigations across multiple video laryngoscope types and broader cohorts are needed for definitive safety conclusions.

Conclusion

Video laryngoscopes benefit anesthesiologists by enhancing glottis visualization during tracheal intubation, yet they pose a unique risk of soft palate injury unreported with traditional direct laryngoscopes. Mitigating this risk depends on integrating direct and video laryngoscopy training, with full-visualization tube advancement and blind-spot elimination embedded in competency assessments. Ultimately, strict adherence to the full-visualization principle is mandatory for all intubation devices to prevent such injuries.

Abbreviations

cm

Centimetre

kg

Kilogram

ASA

American society of anesthesiologists physical status classification

SRNA

Student registered nurse anesthetist

TLIF

Transforaminal lumbar interbody fusion

ENT

Ear, Nose and Throat

Authors’ contributions

Fang Zhang, Mo-min Hua and Xi-Hao Hu collected the data of the patient. Hong-qing Huang contributed to writing the manuscript. Fang Zhang and Yue Xie contributed to performing of anesthesia. Hong Zhang revised the manuscript. All authors read and approved the final manuscript.

Funding

Not applicable.

Data availability

All data related to this case report are contained within the manuscript.

Declarations

Ethics approval and consent to participate

The patient had signed the informed consent for this anesthesia procedure.

Consent for publication

Written informed consent was obtained from the patient for publication of article and any accompanying images.

Competing interests

The authors declare no competing interests.