Lee P. Smith

Operating room fires in otolaryngology: risk factors and prevention

PURPOSE The aim of the study was to characterize the causes of operating room (OR) fires in otolaryngology. MATERIALS AND METHODS A questionnaire was designed to elicit the characteristics of OR fires experienced by otolaryngologists. The survey was advertised to 8523 members of the American Academy of Otolaryngology-Head and Neck Surgery. RESULTS Three hundred forty-nine questionnaires were completed. Eighty-eight surgeons (25.2%) witnessed at least one OR fire in their career, 10 experienced 2 fires each, and 2 reported 5 fires each. Of 106 reported fires, details were available for 100. The most common ignition sources were an electrosurgical unit (59%), a laser (32%), and a light cord (7%). Twenty-seven percent of fires occurred during endoscopic airway surgery, 24% during oropharyngeal surgery, 23% during cutaneous or transcutaneous surgery of the head and neck, and 18% during tracheostomy; 7% were related to a light cord, and 1% was related to an anesthesia machine. Eighty-one percent of fires occurred while supplemental oxygen was in use. Common fuels included an endotracheal tube (31%), OR drapes/towels (18%), and flash fire (where no substrate burned) (11%). Less common fuels included alcohol-based preparation solution, gauze sponges, patients hair or skin, electrosurgical unit with retrofitted insulation over the tip, tracheostomy tube, tonsil sponge, suction tubing, a cottonoid pledget, and a red rubber catheter. CONCLUSIONS OR fire may occur in a wide variety of clinical settings; endoscopic airway surgery, oropharyngeal surgery, cutaneous surgery, and tracheostomy present the highest risk for otolaryngologists. Electrosurgical devices and lasers are the most likely to produce ignition.

What does it take to start an oropharyngeal fire? Oxygen requirements to start fires in the operating room☆

INTRODUCTION Airway fires are a well-described and potentially devastating complication of oropharyngeal surgery. However, the actual factors required to ignite the fire have never been well-delineated in the medical literature. In this study, we used a mechanical model to assess the oxygen parameters necessary to cause an oropharyngeal fire. METHODS An electrosurgical unit (Bovie) was grounded to a whole raw chicken and a 6.0 endotracheal tube (ETT) was inserted into the cranial end of the degutted central cavity. Oxygen (O(2)) was then titrated through the ETT tube at varying concentrations, with flow rates varying from 10 to 15L/min. Electrocautery (at a setting of 15W) was performed on tissue in the central cavity of the chicken near the ETT. All trials were repeated twice to ensure accuracy. Positive test results were quantified by the time required to obtain ignition of any part of the mechanical setup and time required to produce a sustained flame. A test was considered negative if no ignition could be obtained after four minutes of direct electrocautery. RESULTS At an O(2) concentration of 100% and a flow rate of 15L/min, ignition with a sustained flame was obtained between 15 and 30s after initiation of electrocautery. At 100% O(2) at 10L/min, ignition was obtained at 70s with immediate sustained flame. At an O(2) concentration of 60%, ignition occurred at 25s and sustained fire after 60s. At an O(2) concentration of 50% ignition with a sustained flame occurred between 128 and 184s. At an O(2) concentration of 45%, neither ignition nor sustained flames could be obtained in any trial. CONCLUSIONS Operating room fires remain a genuine danger when performing oropharyngeal surgery where electrocautery is performed in an oxygen-enriched environment. In our study, higher O(2) flow rates with higher FiO(2) correlated with quicker ignition in the chicken cavity. A fire was easily obtained when using 100% O(2); as the O(2) concentration decreases, longer exposure to electrocautery is required for ignition. Below 50% O(2) we were unable to obtain ignition. Our study is the first to examine the relative risk of ignition and sustained fire in a mechanical model of oropharyngeal surgery. Decreasing the fraction of inspired O(2) (FiO(2)) to less than 50% may substantially decrease the risk of airway fire during oropharyngeal surgery.

Bipolar radiofrequency plasma ablation (Coblation) of lymphatic malformations of the tongue

OBJECTIVE To describe the removal of lymphatic malformations of the tongue using bipolar radiofrequency plasma ablation. METHODS We report a retrospective case series at a tertiary care academic childrens hospital. Three children with lymphatic malformations of the tongue causing symptomatic pain, bleeding and difficulty eating were treated with bipolar radiofrequency plasma ablation (Coblation). Two children had previously undergone wide local excision, both of whom experienced rapid multifocal recurrences. Using the bipolar radiofrequency plasma ablation wand, each lymphatic malformation was ablated to the submucosal surface of the tongue. In all three children, healing occurred by secondary intention. RESULTS All three children were able to resume a regular diet and were discharged from the hospital by post-operative day 1. After a minimum 6 months follow-up, none of the lesions have recurred and none have required additional treatment. One child has a palpable scar in the central portion of the tongue, where the previous wide local excision had been closed with sutures. She remains asymptomatic without complaints. There were no complications in any child. CONCLUSIONS Bipolar radiofrequency plasma ablation (Coblation) may provide a safe, simple and effective technique for removal of lymphatic malformations of the tongue in children.

Introducing a 3-dimensionally Printed, Tissue-Engineered Graft for Airway Reconstruction: A Pilot Study.

Objective: To use 3-dimensional (3D) printing and tissue engineering to create a graft for laryngotracheal reconstruction (LTR). Study Design: In vitro and in vivo pilot animal study. Setting: Large tertiary care academic medical center. Subjects and Methods: A 3D computer model of an anterior LTR graft was designed. That design was printed with polylactic acid on a commercially available 3D printer. The scaffolds were seeded with mature chondrocytes and collagen gel and cultured in vitro for up to 3 weeks. Scaffolds were evaluated in vitro for cell viability and proliferation. Anterior graft LTR was performed on 9 New Zealand white rabbits with the newly created scaffolds. Three animals were sacrificed at each time point (4, 8, and 12 weeks). The in vivo graft sites were assessed via bronchoscopy and histology. Results: The in vitro cell proliferation assay demonstrated initial viability of 87.5%. The cells proliferated during the study period, doubling over the first 7 days. Histology revealed that the cells retained their cartilaginous properties during the 21-day study period. In vivo testing showed that all animals survived for the duration of the study. Bronchoscopy revealed a well-mucosalized tracheal lumen with no evidence of scarring or granulation tissue. Histology indicated the presence of newly formed cartilage in the region where the graft was present. Conclusions: Our results indicate that it is possible to produce a custom-designed, 3D-printed, tissue-engineered graft for airway reconstruction.

Fire/burn risk with electrosurgical devices and endoscopy fiberoptic cables.

PURPOSE The purpose of the study was to systematically explore the fire and burn risk associated with fiberoptic cables and electrosurgical devices. MATERIALS AND METHODS A 300-W light source was connected to a standard gray fiberoptic light cable. The end of the cable was either rested atop or buried within a cotton towel or polypropylene drape in the presence or absence of 100% oxygen for up to 10 minutes. A monopolar electrosurgical device set at 1 W, 10 W, or 30 W was tested on a cotton towel or polypropylene drape for a period of 30 seconds. All trials were repeated. RESULTS Resting the light cable on top of the cotton towel or polypropylene drape with or without oxygen produced no result. Burying the end of the cable within the drape produced a hole in the drape within 15 seconds both with and without oxygen. Burying the end of the cable within the cotton towel produced a yellow discoloration after 2 minutes both with and without oxygen. The monopolar electrosurgical device set at 30 W burned immediately through the polypropylene drape, producing a skin burn. All other trials with monopolar electrocautery produced no result. No flame or fire was produced in any trial. CONCLUSIONS Fiberoptic cables and electrosurgical generators represent a serious burn risk for surgical patients, with operating room drapes and towels affording only limited protection. Otolaryngologists should be keenly aware of the risks that these devices represent because our specialty uses them frequently.

Single- vs Double-Stage Laryngotracheal Reconstruction

OBJECTIVE To compare single-stage laryngotracheal reconstruction (ssLTR) and double-stage LTR (dsLTR). DESIGN Retrospective medical record review. SETTING Tertiary care childrens hospital. PATIENTS Seventy-one patients underwent 84 procedures (22 ssLTRs and 62 dsLTRs). INTERVENTION Review of preoperative disease severity and surgical outcomes for patients who underwent ssLTR vs dsLTR. MAIN OUTCOME MEASURE Operation-specific and overall decannulation rates. RESULTS Regarding ssLTRs, the mean grade of subglottic stenosis was 2.1 and the overall and operation-specific decannulation rates were 100% and 91%, respectively. The mean grade of subglottic stenosis for double-stage procedures was 2.9, and the overall and operation-specific decannulation rates were 93% and 68%, respectively. Patients who underwent ssLTR and dsLTR were further divided into early and late groups based on whether the posterior graft was sutured in place (early) or not (late). Overall and operation-specific decannulation rates were 100% and 89%, respectively, for the early single-stage group and 100% and 92% for the late group. Regarding the dsLTR group, overall and operation-specific decannulation rates were 88% and 42%, respectively, for the early group and 95% and 79% for the late group. Among all groups, there was no significant difference in overall decannulation rates (P > .05). Single-stage LTR offered an increased rate of operation-specific decannulation over dsLTR (P < .05). However, that difference was not significant between the late ssLTR and the late dsLTR groups (P > .05). CONCLUSION Careful assessment of preoperative disease severity and overall medical status will help surgeons choose between ssLTR and dsLTR, maximizing patient outcomes for both modalities.

Diagnosis and treatment of pediatric vallecular cysts and pseudocysts

OBJECTIVE To review the experience at a childrens hospital diagnosing and treating vallecular cysts. SECONDARY OBJECTIVES To determine if cyst type, operative mode, or ages are risk factor(s) for recurrence. METHODS Chart review of eleven children with vallecular cysts and pseudocysts from 1997 to 2009. RESULTS The most common presenting symptoms were stridor (8/12, 67%), respiratory distress (7/12, 58%), and feeding difficulties (4/12, 33%). Symptoms of gastroesophageal reflux disease were present in 67% of patients and 17% carried a concurrent diagnosis of laryngomalacia. Eleven of twelve patients required operative intervention, the majority of which were transoral endoscopic procedures. Three patients (3/11, 27%) had recurrences. Two of these patients required only a second procedure, but one patient required multiple procedures. Fifty percent (2/4) of the patients 2 years or older experienced a recurrence, whereas only 14% (1/7) of the patients less than 2 years old had a recurrence, a difference which was not statistically significant (p=0.49). Pseudocysts tended to recur more frequently than vallecular cysts. (p=0.13). Surgical approach (marsupialization versus total excision) did not affect recurrence rate. One patient with a small, asymptomatic cyst was observed and continues to be symptom-free. There were no surgical complications. CONCLUSIONS Vallecular cysts and pseudocysts are rare congenital lesions of the upper aerodigestive tract. Vallecular pseudocysts tended to recur more than vallecular cysts in our series. Surgery is the treatment of choice for symptomatic patients; smaller cysts may be followed closely.

Otolaryngologists may not be doing enough to diagnose pediatric eosinophilic esophagitis

OBJECTIVE To systematically evaluate the diagnosis of eosinophilic esophagitis (EE). METHODS A retrospective review of 657 patients seen at the EE center of a tertiary care childrens hospital between 1994 and 2007 was performed. Charts were reviewed for the 144 patients who were also seen by the otolaryngology service. RESULTS One hundred forty-four patients received 193 otolaryngology-related diagnoses. Eustachian tube dysfunction (27.5%) and sleep disordered breathing (24.9%) were the most common, followed by dysphagia (13.0%), rhinosinusitis/nasal congestion (9.3%) and airway stenosis (5.2%). Seventy-nine patients (54.9%) had a pre-existing diagnosis of EE at the time of their otolaryngology consultation. Twenty-one patients (14.6%) were referred to the gastroenterology service for evaluation for EE. Forty-four patients (30.5%) remained undiagnosed. Twenty-five of these patients presented with dysphagia, 16 of whom were not previously diagnosed with EE; only 4 of these 16 patients were referred for evaluation for EE. In one case, a child with moderate sized tonsils underwent adenotonsillectomy for dysphagia and failure to thrive; this patient was diagnosed with EE 1 month post-operatively. CONCLUSIONS Twenty percent of patients with EE may require care by an otolaryngologist for a myriad of complaints. Even experienced pediatric otolaryngologists may not recognize this condition. Otolaryngologists should consider EE in patients presenting with dysphagia. A careful gastroenterology review of symptoms may also allow otolaryngologists to identify EE in patients with allergy mediated nasal complaints, or laryngeal/airway disorders.

Three dimensional printing: A review on the utility within medicine and otolaryngology

Three dimensional (3D) printing is a novel technique that has evolved over the past 35 years and has the potential to revolutionize the field of medicine with its inherent advantages of customizability and the ability to create complex shapes with precision. It has been used extensively within the fields of orthopedics, dentistry, and craniofacial reconstruction with wide ranging utility including, medical modeling, surgical planning and the production of custom plates, screws and surgical guides. Furthermore, it has been used for similar means in the field of Otorhinolaryngology and also has potential to revolutionize the treatment of airway malacia. In fact, 3D printed external tracheal splints have already been studied in several pediatric patients with very promising results. The emerging field of 3D bioprinting, which integrates tissue engineering with 3D printing, may produce a paradigm shift with the potential introduction of customized functional biologic replacements.

Patient selection in congenital pyriform aperture stenosis repair – 14 year experience and systematic review of literature

PURPOSE Congenital nasal pyriform aperture stenosis (CNPAS) is a rare cause of respiratory distress in neonates that may necessitate early surgical intervention. Restenosis and granulation are postoperative concerns that may prompt a return to the operating room. Reoperation places children at increased risk of perioperative complications and prolonged hospital stays. We are presenting a review of our institutional experience of 16 patients treated for CNPAS over a 14 year period and a systematic review with pooled data analysis to determine the effect of craniofacial and neurologic anomalies on surgical success. METHODS Retrospective chart review of all cases of CNPAS treated at our tertiary childrens hospital between 1999 and 2013. Systematic review of English language literature was conducted adhering to the PRISMA statement to determine the effect of neurologic anomalies and craniofacial dysmorphism (CFD) on surgical failure for CNPAS treatment. Univariate and exact multiple logistic regression were used for analysis of an individual patient data analysis. RESULTS 10 patients had surgery and 6 were treated medically. Average pyriform apertures were 5.71±1.72mm for the surgical group and 4.83±1.26mm for the medical group (p=0.38). 31% had neurological impairments. 31% had craniofacial dysmorphisms (CFD). 2 patients developed restenosis and 1 required tracheotomy. Both of these patients had other CFDs. Literature review captured 63 surgical patients and 9 failures in 6 series of CNPAS. 4.6% of patients without CFD and 36.8% of patients with CFD required surgical revision (p=0.023, OR13.8). CONCLUSION When repairing CNPAS, co-morbidities must be considered. Impaired respiration, central neurologic deficits and extensive craniofacial anomalies may require additional surgeries or an alternative approach.