Comparing intubation techniques of Klippel-Feil syndrome patients in the last 10 years: a systematic review.

Context: Klippel-Feil syndrome (KFS) is a rare congenital abnormality characterized by cervical vertebral fusion. Patients typically present with a triad of short neck, low posterior hairline, and limited cervical range of motion. The location and quantity of vertebral fusions in KFS makes airway management challenging in the field of anesthesia. Anesthesiologists select intubation methods based on perceived difficulty, making this paper essential to the field.

Objectives: The purpose of this study is to analyze first-attempt intubation success rates of KFS patients by intubation technique and stratified by location and quantity of cervical fusions and a Mallampati score if reported.

Methods: This is a systematic review of all case reports on PubMed in the last 10 years utilizing the keywords "KFS," and subsequently screened searching "anesthesia" and "intubation." Examiners reviewed the remaining 27 articles for fusion abnormalities and intubation techniques utilized. The articles detail fiberoptic, direct, laryngeal mask airway (LMA), and video-guided intubation techniques, and the success rates were analyzed.

Results: Of the 1234 KFS articles found, 657 were case reports with 157 being in the last 10 years. After review, 27 case reports presenting 30 cases were included. The average age reported was 25.4 ± 21.6 and 73.3 % were female. Direct (n=10), fiberoptic (n=12), video-guided (n=6), and LMA (n=2) were the chosen first-attempt intubation maneuvers. Fiberoptic and video-guided intubations reported 83 % success, while direct and LMA reported 50 % success. Higher success rates were found in patients with two cervical segment fusions (70 %) when compared to three or more fusions (33 %). Inferior vertebral fusions (C5-T1) reported higher success than midcervical fusions (C3-C5), 100 % and 33 %, respectively. Mallampati class 4 had the highest success (100 %), although further analysis showed fiberoptic intubation was utilized in each of these cases, skewing the data.

Conclusions: Fiberoptic and video-guided intubation in KFS patients offers the highest success rates of intubation. There were limitations in this study due to the number of case reports available. Although there may be confounding variables to consider based on the case presentation and surgery performed, fiberoptic endotracheal intubation should be considered the gold standard when intubating KFS patients.