|LETTER TO EDITOR
|Year : 2020 | Volume
| Issue : 2 | Page : 102-104
J stylet-A preliminary report
Jitin N Trivedi
Consultant Anesthesiologist, 12, “Swastik”, Vrundavan Bunglows, Behind GEB Office, Ankleshwar, Gujarat, India
|Date of Submission||02-Jun-2020|
|Date of Acceptance||06-Aug-2020|
|Date of Web Publication||30-Aug-2020|
Dr. Jitin N Trivedi
12, ‘Swastik’, Vrundavan Bunglows, Behind GEB Office, Ankleshwar - 393 001, Gujarat
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Trivedi JN. J stylet-A preliminary report. Airway 2020;3:102-4
Airway management is one of the most important skills in anaesthesiology, and inability to secure the airway can lead to catastrophic results. The author has developed a J-shaped stylet from nitinol alloy, a superelastic biocompatible material, to assist in difficult intubations. This stylet reaches the larynx without much manipulation, thereby providing quick control of the airway.
The J-stylet is made up of medical-grade nitinol and is dispensed as a disposable product with a diameter of 0.5/0.7 mm for adults. It is 78–80 cm in length with a straight length of 65 cm and a curved length of 13 cm and 15 cm in the oral and nasal versions, respectively [Figure 1] and [Figure 2]. The J-arch attains an anatomical advantage such that when introduced through the nose, it comes out of the nasopharynx into the oropharynx posteriorly and then naturally moves as it is advanced towards the hypopharynx into the laryngopharynx. It aligns to the base of the tongue and the wire tip rests very near to the vocal cords or in either pyriform fossa. The distal tip of the nasal stylet has a 30° to 45° anterior curve which points the wire towards the laryngeal inlet and also helps in lifting the epiglottis. The small diameter of the wire allows passage through the narrow orifices and railroad/exchange different-sized endotracheal tubes. The J-stylet is integrated in a dual-lumen silicone tube, where it is embedded in one tube and the other hollow tube can work as an oxygen-supplying cannula.
|Figure 1: Oral J-stylet (0.5/0.7 mm medical-grade Nitinol). The total length of the stylet (part A to part C) is 78 cm; part A: oxygen-supplying or carbon dioxide-measuring port; part B: nitinol wire in other lumen; part C: oxygen-supplying or carbon dioxide-measuring hollow lumen in one tube and blunt tip of the nitinol wire in another lumen|
Click here to view
|Figure 2: Nasal J-stylet (0.5/0.7 mm medical-grade Nitinol). The total length of the stylet (part A to part C) is 80 cm; distal tip of the stylet (Q) 30° to 45° anterior curve, angled tip for smooth entry; part A: oxygen-supplying or carbon dioxide-measuring port; part B: nitinol wire in other lumen; part C: oxygen-supplying or carbon dioxide-measuring hollow lumen in one tube and blunt tip of the nitinol wire in another lumen|
Click here to view
The J-stylet can be introduced without the use of a laryngoscope or muscle relaxant. It can be introduced by nasal (preferred) or oral route, and the outer diameter of the stylet permits its use with a laryngoscope, airway and supraglottic airway device (SAD). With direct laryngoscope/videolaryngoscope, one can visualise the passage of the J-stylet into the trachea. It can be used in supine, sitting and semi-sitting positions.
With the patient lying supine, the J-stylet is introduced, with its arch facing caudally through the external nare. It will align to the airway anatomy and abut on to the hard palate followed by the soft palate and thereafter curve down behind to emerge from the posterior part of the oropharynx. Subsequently, due to its superelasticity, the J-curve tries to revert to its original shape in the posterior oropharyngeal space. This acute recoil lifts the tip of the stylet in the hypopharyngeal area, making it reach towards the epiglottis and the laryngeal inlet. It can also be passed through a nasopharyngeal airway. In studies on manikins, it was consistently positioned over the laryngeal inlet and mostly negotiated into the trachea as confirmed by endoscopy and also facilitated endotracheal intubation. With frequent use and familiarisation with this stylet, one may need to use the Magill's forceps less often for directing the tube into the larynx.
Oral J-stylet can be used through the Guedel airway or an SAD. When the stylet exits from the distal end of the oral airway, it recoils upwards and abuts onto the base of the tongue and epiglottis and enters the larynx.
It has the potential for usage in difficult airway management, emergency intubations in intensive care unit, ambulances or outside the operation room. It can act as an airway conduit in cardiopulmonary resuscitation and apnoeic oxygenation therapy; as an airway exchange catheter and as a conduit device for difficult extubation. Due to its small diameter, it will be very useful in cases of severe laryngeal oedema/tracheal stenosis for maintaining oxygenation till an ideal airway is secured. The usage could be limited or contraindicated by the presence of oral or nasal pathologies, basal skull fractures and maxillary fractures (especially involving hard palate) and retro/parapharyngeal abscess.
The unique design and material characteristics of the J-stylet impart it 'a quick chance of reaching the laryngeal inlet without highly skilled expertise'. The stylet is available as an inexpensive urology guide wire.
The compliance of nitinol allows its bending to suit the airway anatomy and contours in the lumen of various airway devices. The superelastic property of nitinol allows its large deformation compaction into a small diameter airway, SAD or endotracheal tube for minimally invasive deployment in vivo. It causes minimal tissue compression and thereby minimal cardiorespiratory disturbance. Due to its superelasticity and small diameter, it is least likely to create a false passage or tissue trauma when introduced blindly. The various attributes allow for easy and successful use by novice operators in many situations, including in difficult airway management. It can work both as a ventilatory device and as a conduit for endotracheal intubation and has a potential for use with different laryngoscopes. Direct blind intubation has 55% success rate with the laryngeal mask airway (LMA), which could improve with the use of a J-wire through the LMA. Removing an endotracheal tube over the J-stylet during extubation could help to maintain a patent, stiff and less irritable conduit for the anaesthesiologist when reintubation is anticipated. Even in the ICU, it will be a good practice to extubate over the J-stylet. It can also potentially be used to secure the airway via emergency cricothyroidotomy (where it can be threaded through the cricothyroid needle into the trachea). Thereafter, an endotracheal tube can be railroaded over it. It can also be used in retrograde intubation or digital intubation.
The J-stylet is a unique guidewire that has the potential to be useful as an adjunct for intubation (oral/nasal) by various techniques and devices. It can be useful in all the steps of the difficult airway algorithm and also in extubation algorithms. It can also be used in emergency room, ICU and nonanaesthesia settings.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Sood J. Laryngeal mask airway and its variants. Indian J Anaesth 2005;49:275-80. [Full text]
Poncet PP. Applications of Superelastic Nitinol Tubing. USA: MEMRY Corporation, Engineering and Technology (IJMET) 2016;7-1: 119-130.
Duerig T, Pelton A, Stockel D. An overview of nitinol medical applications. Materials Sci Eng 1999;A273-5:149-60.
Kannaujia A, Srivastava U, Saraswat N, Mishra A, Kumar A, Saxena S. A preliminary study of I-gel: A new supraglottic airway device. Indian J Anaesth 2009;53:52-6.
] [Full text]
Tarniţă D, Tarniţă DN, Bîzdoacă N, Mîndrilă I, Vasilescu M. Properties and medical applications of shape memory alloys. Rom J Morphol Embryol 2009;50:15-21.
Henderson E, Nash DH, Dempster WM. On the experimental testing of fine Nitinol wires for medical devices. J Mech Behav Biomed Mater 2011;4:261-8.
[Figure 1], [Figure 2]