Review of the scientific literature dedicated to investigating how residual structures impact surgical outcomes in chronic rhinosinusitis (CRS) patients, providing information on the frequency of anatomical remnants after endoscopic sinus surgery (ESS).

This review has been reported following the recommendations of the SWiM guideline. PubMed, Cochrane Library, Embase, and Web of Science were searched until April 2024. Studies selected for the systematic review were assessed about quality and risk of bias using the Oxford Centre for Evidence-Based Medicine Levels of Evidence and STROBE. The findings were analyzed descriptively and qualitatively, aligning with EPOS and ICAR guidelines.

Fourteen relevant studies met the inclusion criteria for qualitative synthesis. Prospective and retrospective cross-sectional designs, focusing on revision ESS, were included. Four studies examined full-house functional ESS (FESS), three focused on frontal sinus surgery, four on conventional FESS and three did not specify the surgery type. The risk of bias was assessed, revealing significant variability in study quality and a low level of evidence. Wide variability was found in anatomical structures remaining after ESS, most notably in retained uncinate process (29.6–64%), agger nasi cell (4.5–83.33%) and frontoethmoidal cells (40.7–96.8%). Observations on concha bullosa, septal deviation and lateralization of the middle turbinate revealed distinct patterns among the included studies.

This systematic review underscores the persistent challenge of incomplete resection of anatomical structures in revision surgeries for CRS. The variability in the retention of key structures highlights the complexity of surgical outcomes and the need for further refinement in surgical techniques.