Intraoperative mechanical failure of a 25-gauge vitreous cutter

Mechanical Property Comparison of 23-, 25-, and 27-Gauge Vitrectors across Vitrectomy Systems

OBJECTIVE

To investigate the mechanical properties of 23-, 25-, and 27-gauge vitrectomy vitrectors across 3 different vitrectomy systems to inform surgical techniques.

DESIGN

An experimental study that did not involve any human subjects.

METHODS

Nine vitrectors (3 each of 23-, 25-, and 27 gauge) from Alcon, Dutch Ophthalmic Research Center (DORC), and Bausch & Lomb (B/L) were measured. Measurements were performed using electroforce displacement at the tip and 15 mm from the tip. Five measurements were performed at each location, and fully elastic deformation was ensured.

MAIN OUTCOME MEASURES

The main parameter being measured was the force in grams (gf) necessary to deflect the vitrectors vertically downward by 1 mm, either at the tip of the vitrector or 15 mm from the tip.

RESULTS

A total of 90 measurements were performed. Across brands, B/L demonstrated the least stiffness at both the tip and at the 15-mm point for 23-gauge (8.0±0.3gf, 67.3±1.0gf), 25-gauge (6.8±0.3gf, 60.5±0.4gf), and 27-gauge (3.3±0.1gf, 33.9±0.5gf) vitrectors. Although there was only a small decrease in the stiffness in the 25-gauge vitrector compared with the 23-gauge vitrector at the 15-mm point, this difference was statistically significant for Alcon (P < 0.001), DORC (P < 0.001), and B/L (P < 0.001).

CONCLUSIONS

Based on this study, 25-gauge vitrectors, although larger than the 27-gauge vitrectors and less stiff than the 23-gauge vitrectors, may offer favorable compromise between stiffness and gauge size. However, surgeon experience, preference, and the type of surgery being performed should be paramount when making the final vitrector selection. Knowledge of these mechanical properties may aid surgeons in choosing between gauge size and vitrectomy system to optimize their comfort and efficiency.

Bacterial endophthalmitis associated with a broken and retained small-gauge vitrectomy cannula

PURPOSE

To report a case of bacterial endophthalmitis associated with a retained small-gauge vitrectomy trocar.

METHODS

Retrospective case report of a 66-year-old woman who underwent 25-gauge vitrectomy surgery for an epiretinal membrane who presented with postoperative bacterial endophthalmitis and hand motions vision 3 weeks later.

RESULTS

Aqueous and vitreous biopsy revealed Corynebacterium species sensitive to vancomycin. The patient was initially treated with intravitreal and subconjunctival injections of vancomycin, ceftazidime, and dexamethasone. Surgical exploration during a subsequent vitrectomy surgery revealed a retained, transscleral 25-gauge cannula beneath a subconjunctival abscess. The cannula was removed, and the patient was treated with vitrectomy, debridement and closure of the transscleral wound, and injection of intravitreal antibiotics. Fifteen months of follow-up revealed no recurrence of infection and improvement of vision to 20/150.

CONCLUSION

Although rare, retained small-gauge vitrectomy cannulas may lead to vision threatening ocular infection. Care should be taken to inspect both the wound and the removed trocar system to ensure complete removal of this surgical device. Detailed counts of all surgical equipment should be routinely performed at the conclusion of vitrectomy surgery.