XEN Implant Fracture during Needling Procedure

Sara Olivari, Carlo A. Cutolo, Letizia Negri, Francesca Cappelli, Valeria Testa, Michele Iester, Carlo E. Traverso

Research output: Contribution to journalArticlepeer-review


Purpose: The XEN implant is a small hydrophilic stent designed to be implanted permanently for the treatment of glaucoma. As others bleb forming surgical procedures, needling is part of postoperative care. We describe three cases of XEN fracture of the subconjunctival portion occurred during the needling procedure. Methods: To describe the clinical and anatomical outcomes in three cases of XEN fracture caused by needling procedure. Results: In our case series of XEN procedures (n=170), bleb needling has been performed in 98 cases (57.6%). In three cases (3.1%) we observed unintentional damage to the implant after the procedure. The mean distal segment length of the fractured XEN measured 0.83 (range 0.7 to 1) mm. Despite the adverse event the mean IOP changed from 25.0 (range 21 to 30) mmHg preneedling to 12.0 (range 10 to 14) post-needling with a mean follow-up of 15.3 (range 11 to 18) months. No vision-threatening complications were recorded during the entire follow-up. Conclusions: XEN fracture related to needling procedure should be considered as a possible adverse event of the bleb management. Because XEN is composed of a soft and flexible gelatin material, it could be easily damaged by the needle. The fracture doesn't seem to impair the efficacy of the draining device. As a matter of fact, according to Poiseuille's laws, shortening of the implant's length decreases the resistance while increasing the flow rate. Despite our positive results, it is recommended to preserve the integrity of the implant.

Original languageEnglish
Pages (from-to)1086-1089
Number of pages4
JournalJournal of Glaucoma
Issue number12
Publication statusPublished - Dec 1 2019


  • glaucoma
  • needling
  • surgery
  • XEN implant

ASJC Scopus subject areas

  • Ophthalmology


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