Intraoperative fracture of phacoemulsification tip.

Phacoemulsification (phaco) is an established procedure for cataract extraction and has undergone a significant advances in techniques, machines and phaco tips. The Aspiration Bypass System (ABS) phaco tip was introduced for phacoemulsification in 1998. The ABS tip allows fluid to be drawn through the opening when the phaco tip is occluded by nuclear material. The ABS tip allowed the safe use of high vacuum and flow rates and improved chamber stability by decreasing surge and therefore reducing intraoperative complications. To date, no disadvantages of ABS tips have been reported. We report a unique case of an intraoperative break of an ABS phaco tip during routine cataract surgery.

INTRODUCTION

Phacoemulsification is the most commonly used surgical technique for cataract extraction. Advantages of phacoemulsification include a small incision, minimally induced astigmatism and fast healing.1 As with other surgeries, complications can occur during phacoemulsification (phaco). Posterior capsule rupture is likely the most common complication encountered by surgeons learning phaco.

Instrument breakage during phaco may occur and can have a detrimental effect on the eye.12 To our knowledge, an intraoperative fracture of a phaco titanium needle tip has not been reported in the peer review literature. In this case report, we present a unique case of intraoperative phaco tip fracture.

CASE REPORT

Phacoemulsification with intraocular lens (IOL) implantation in the left eye was performed in a 61-year-old female. Preoperatively, the best-corrected visual acuity (BCVA) was 20/200. The patient had grade II nuclear sclerosis with grade II cortical cataract in the left eye. Intraocular pressure (IOP) was 14 mmHg, and no other significant ocular abnormality was noted.

Surgery was performed under topical anesthesia with 2% Xylocaine gel. A 2.75 mm temporal clear corneal incision was made with a keratome. Continuous curvilinear capsulorrhexis, hydrodissection and hydrodelineation were performed without complications. Phacoemulsification was then performed using a standard 20-gauge ABS (Aspiration Bypass System) phaco tip (Infiniti, Alcon laboratories, Inc., Fort Worth, TX, USA). As soon as the phaco tip was inserted into the nucleus, the surgeon realized there was no vacuum build up and carefully evaluated the problem. The phaco parameters were verified to be appropriate. The same steps were repeated, however it was noted that a segment of the titanium tip was broken. The broken fragment remained inside the silicone sleeve [Figure 1]. The phaco probe was carefully taken out ensuring the removal of the phaco needle with the broken end in toto. The anterior chamber (AC) was reformed with viscoelastic and a thorough search for any potential fragments under the operating microscope did not reveal any residual material. The surgery was completed uneventfully with a new titanium tip. Thereafter, we meticulously examined the broken tip under the operating microscope [Figure 2a-c]. The broken ends matched perfectly with no missing fragments, thus confirming no retained foreign body within the AC. It was noted that the tip had broken in the area where the ABS microhole was present (i.e., 3 mm from the distal open end). Electron microscopy (EM) of the broken ends revealed a smooth break near the microhole of the ABS tip [Figure 3a-d]. The postoperative course was uneventful, and the patient achieved BCVA of 20/25 with normal IOP and a quiet AC at 3 months postoperatively.

Figure 1

The fractured ABS phaco tip within the silicone sleeve inside the anterior chamber (red arrow)

Figure 2

(a) The broken ends of the phaco tip without the sleeve (b and c): Apposition of the broken ends, thus ensuring no missing fragments inside the anterior chamber

Figure 3

(a) Electron microscopy of the distal end of the titanium tip, which reveals a smooth break near the microhole of the ABS tip (b) Magnified view (electron microscopy) of the distal fragment (c and d) Magnified view (electron microscopy) of the proximal fragment with a smooth break near the microhole of the ABS tip

DISCUSSION

Breakage of instruments during phacoemulsification can lead to retained intraocular foreign bodies (RIOFB). These commonly arise from second instrument tips, irrigation tubing and chipping of phaco probe.23456 These retained fragments can potentially lead to an increase in postoperative inflammation and damage to the intraocular tissue. The fragments have been presumed to be associated with contact between an instrument such as a chopper or spatula and the vibrating phaco tip.7 Other reports blame metal fatigue of the hand-piece or adherence (annealing) of a fragment to a new phaco tip that can be shaken loose with vibration.8

Fracture of the phaco tip could give rise to various complications apart from RIOFB depending on the stage of the surgery it occurred like damage to corneal endothelium, iris, trabecular meshwork, posterior capsule or ciliary zonules, which may lead to corneal edema, hyphema, posterior capsular or zonular dehiscence, vitreous loss, prolonged surgical time, postoperatively prolonged inflammation and discomfort and ultimately poor visual outcome. We were fortunate that the fracture of the phaco tip did not result in multiple fragments. Moreover, since the broken fragment was still inside the silicone sleeve, it was possible to remove the needle with the broken ends in toto without enlarging the corneal incision or causing further damage. Therefore early identification of this condition is important.

In our case, the fracture of the phaco tip was noted at the ABS microhole site. We postulate that this could be due to the inherent weakness created at this site as EM revealed a smooth break near the microhole. It may also be due to a manufacturing defect which would require further investigation. Trauma to the phaco tip either by the second instrument or any inadvertent cause is unlikely as in this case the broken ends should be ragged rather than smooth.

The ABS technology developed by Cavitron was first used in neurosurgical and general surgical units for more efficient aspiration of tumor masses. Since 1985, all Cavitron ultrasonic surgical aspirator tips have been equipped with these apertures.

More recently (1998), Alcon Laboratories introduced the ABS tip, a single 175 μm hole drilled into the shaft of the tip 3.0 mm from the open end.9 The purpose was to allow fluid to be drawn through the opening when the phaco tip was occluded by nuclear material. The ABS tip uses high vacuum and flow rates, safe and improved chamber stability by decreasing surge during occlusion, cools the incision site, and protects the wound from thermal injury with continuous fluid movement.9101112 One should therefore bear in mind that the phaco tip develops an inherent weakness in the microhole region. It is anticipated that they may be more prone to damage, and manufacturing defects. We therefore advise careful inspection of all instruments before introducing them into the eye. Inspection must include the phaco tip and sleeve separately for any breaks or cracks, which tends to be overlooked due to their complementary nature.

It was the first time that we noted such a complication in our 12 years of surgical experience with the ABS phaco tips. In summary, the ABS phaco tip fracture is an uncommon complication and with early identification of this condition and proper management, major complications can be avoided.