AbstractPurposeRemoval of the current calcium alginate packing materials to the middle meatus in endoscopic sinus surgery (ESS) is usually accompanied by discomfort or pain owing to the hard and brittle nature of these materials. Plus moist HS-W® is a new calcium alginate packing material released in 2022 developed to overcome this issue by changing the uronic acid component. We aimed to compare the discomfort/pain during the removal of Plus moist HS-W® with Kaltostat®, as well as their suitability as packing materials in ESS.MethodsKaltostat® and Plus moist HS-W® were used as packing materials in 22 and 21 patients who underwent ESS in 2021 and 2022, respectively. Patients were asked to rate the pain during the packing removal 10 days after ESS using the Numerical Rating Scale (NRS). The ratio of residual packing materials, number of suctions (insertions/extractions of the suction cannula), and time required to remove packing materials were measured. Postoperative complications such as hemorrhage, local infection, lateralization of the middle turbinate, and synechia of the middle meatus were also evaluated.ResultsThe Plus moist HS-W® group exhibited significantly lower NRS pain scores, a lower ratio of residual packing materials, a reduced number of suctions, and a shorter time required to remove the packing. No obvious postoperative complications occurred in both groups except for one suspicious case of a slight infection in the Kaltostat® group.ConclusionCompared with Kaltostat®, Plus moist HS-W®, characterized by better gelatinization than Kaltostat®, benefits patients by minimizing discomfort/pain during removal.Level of evidenceLevel 3.