Superior Placement Risk Factor For Premature Monocanalicular Stent Extrusion

Brian Sajorda, BA

Preliminary results of a statistical analysis showed that superior placement, male sex, and younger age could be risk factors for premature monocanalicular stent extrusion.

Brian Sajorda, BA, and a team of investigators compared retention rates of superiorly versus inferiorly place monocanalicular stents in pediatric patients. The research, published on ARVOLearn due to the cancellation of the 2020 Association for Research in Vision and Ophthalmology (ARVO) annual meeting, aimed to better understand whether superior or inferior placement impacted the risk of early stent extrusion.

Sajorda, a medical student at Howard University College of Medicine, and the team also evaluated whether superior versus inferior stent placement affected rates of additional post-operative complications such as irritation, tearing, and foreign body sensation.

The single site, retrospective review included patients 6 months to 16 years old with monocanalicular stent placement. Patients were included if any type of monocanalicular stent was used. Exclusion criteria included if there was no electronic health record (EHR) or premature extrusion or removal by the surgeon.

A total of 43 eyes of 37 patients met the criteria for study inclusion. A primary analysis demonstrated that premature extrusion occurred in 7 out of 17 superiorly placed stents and 6 out of 26 inferiorly placed stents, Sajorda said.

The data represented an extrusion rate of 41.2% in the superior group versus 23.1% in the inferior group. The difference did not reach statistical significance (P=.31).

A secondary analysis evaluated different risk factors for premature exclusion. The team compared extrusion rates based on stent indication, sex, and patient age at surgery (<5 years old vs >5 years old).

The data showed a slightly higher rate of premature extrusion in patients who had a stent placed for refractory nasolacrimal duct obstruction (35%) compared to those who had a stent placed for canalicular laceration repair (31.3%) (P=1). What’s more, male patients had a higher rate of premature extrusion (37.5%) compared to female patients (21.1%) (P=.32). Patients <5 years old had a higher rate of premature extrusion of 33.3% compared to those >5 years old (P=.74).

None of the factors evaluated reached statistical significance.

When comparing post-operative complications between the superior and inferior group, the investigators found that both groups experienced a total of 16 documented complication events. The most common complications were tearing (superior: 8 vs inferior: 11), discharge (superior: 4 vs inferior: 3), and conjunctival injection (superior: 2 vs inferior: 1) (all P=.21).

“Overall, placement of a monocanalicular stent led to successful outcomes and eventual resolution of tearing,” Sajorda said.

The investigators are continuing the review to further elucidate the findings and to further power the study and to elaborate on factors that influence post-operative outcomes following monocanalicular stent placement in the pediatric population. Future results could provide guidance to help optimize the approach of the common surgical procedure, Sajorda concluded.

The study, “Superior versus inferior monocanalicular stent retention in the pediatric population,” was published online on ARVOLearn.