Author: Chase Doyle
A new fiber-optic–guided system has been shown to improve the performance of percutaneous dilational tracheostomy (PDT) by facilitating faster and more accurate needle puncture.
“This new fiber-optic–guided technique is a reliable method to facilitate quicker and safer needle-guided puncture,” said Pin-Tarng Chen, MD, attending anesthesiologist at Taipei Veterans General Hospital and associate professor at National Yang-Ming University School of Medicine, in Taipei, Taiwan. “Based on the results of this study, the fiber-optic–guided system improves the accuracy and performance of bedside PDT.”
The results of the randomized controlled trial showed that patients assigned to the fiber-optic technique had significantly faster navigation time, needle puncture time, total puncture time and total PDT time than the control group. Moreover, with the fiber-optic–guided system, first-puncture attempts were successful 100% of the time, compared with 75% using the conventional approach.
Accurate needle-guided puncture of the trachea is one of the most critical and dangerous steps during bedside PDT, according to Dr. Chen. He added that severe complications can occur, including cardiopulmonary arrest, hemorrhage, tube obstruction or displacement, pneumothorax, pneumomediastinum, aspiration, posterior tracheal wall lesion, fracture of tracheal rings, false passage, difficult tube placement and subcutaneous emphysema.
“Although instruments such as forceps are traditionally used to lightly compress the trachea wall to locate the puncture site under bronchoscopy, there are still many potential problems with this approach,” Dr. Chen said. “In order to reduce the risk of complication, we invented a new guiding system to facilitate the needle puncture and improve the safety and quality of PDT.”
The fiber-optic–guided needle consists of an infrared light source, ejection assembly and optic fiber. The basic purpose of the new device, Dr. Chen said, is the transmission of light across the trachea to illuminate a large spot, which is punctured simultaneously under bronchoscopy. A previous study done in porcine models confirmed the safety and efficacy of the device.
Fiber-optic Versus Conventional
Following IRB approval, Dr. Chen and colleagues randomly assigned patients undergoing PDT to a control group (n=20) or fiber-optic group (n=20). After incision of the anterior neck, patients in the control group received standard of care. In the fiber-optic group, following incision and subcutaneous dissection of the lower neck, a wireless endoscope was introduced into the trachea with its tip located between the first and second tracheal rings. Under direct vision of the spotlight, the new puncture needle device was gently inserted through the skin incision site to ensure that the intended puncture was only on the middle upper surface of the trachea.
“The projection path of the light should be vertical to the midline of the anterior trachea wall,” Dr. Chen said. “The target we’re looking for under endoscopy is a clear spotlight instead of a blurry one; it implies the optimal direction of the optic fiber has been found. The ejection sleeve is then activated to push the guiding needle into the trachea. Finally, once the guiding needle appears in the trachea, the catheter is inserted into the trachea, under direct vision.”
The investigators recorded the following outcomes: number of puncture attempts, navigation time, puncture time, total puncture time, total PDT time and complications associated with the procedure.
As Dr. Chen reported at the 2017 annual meeting of the Society of Airway Management, with the guidance of the fiber-optic needle, all punctures in the fiber-optic group were performed successfully in the first attempt. In contrast, in the control group, five patients required a second attempt. Moreover, Dr. Chen said, when compared with the conventional approach, the fiber-optic group tended to have faster navigation time (8.5±0.6 vs. 16.3±3.9 seconds), needle puncture time (9.1±0.9 vs. 25.2±4.9 seconds), total puncture time (18.2±2.1 vs. 40.2±6.7 seconds) and total PDT time (75.2±4.1 vs. 111.1±8.2 seconds). Finally, puncture sites in the control group were accurately located only 50% of the time, compared with a 100% accuracy rate in the fiber-optic group.
No demographic differences were observed between the control and fiber-optic groups, and there were no late complications in either group, the authors noted.
David Wong, MD, professor of anesthesiology at the University of Toronto, and the moderator of the session, noted the relatively low average body mass index (BMI) of patients enrolled in the study.
“The BMI was approximately 24 for both the control and fiber-optic groups, which would be rare for patients in the United States. Did you exclude patients with higher BMI?” Dr. Wong asked.
“BMI was not part of the enrollment criteria,” Dr. Chen said. “These patients just happened to not be obese.”
“Did you use light from the bronchoscope to identify the needle puncture spot or guide the needle puncture in the control group?” Dr. Wong asked.
“Conventionally, muscular forceps are used to compress the trachea and locate the second and third tracheal ring,” Dr. Chen said. “We then remove the forceps and use the needle to puncture the trachea, but accuracy can be impaired without the forceps to guide us, and multiple attempts are often required. Because of this, we’ve tried to invent a new device that enables real-time guidance for percutaneous puncture.”