In a perfect world, cataract surgeries would be without complication, and any resulting displacement of nuclear fragments into the vitreous cavity would be a thing of the past. Despite improvements in surgical technique and platforms, our reality is that the incidence of posteriorly displaced lens fragments after phacoemulsification ranges between 0.3 and 1.1%. These retained nuclear fragments (especially those 2mm or larger), can go on an inflammation spree, causing lens-induced uveitis or secondary glaucoma and a cascade of ocular issues. So, they must be removed . . . which is easier said than done.
Although some small fragments can be absorbed, more significant material must be removed via pars plana vitrectomy (PPV). The usual approach for retrieving nuclear fragments in the posterior segment is a standard 3-port PPV and release of vitreous adhesions to the dropped nucleus, followed by fragmentation and removal of nuclear material using a phacofragmatome. Dr. Sharon Fekrat, Associate Professor of Ophthalmology and Surgery at Duke University School of Medicine had been thinking about this technique for many years and knew that there had to be a better way.
Particularly in this era of smaller-gauge vitreous surgery, Dr. Fekrat felt that enlarging one or more sclerotomies to accommodate the 20-gauge phacofragmatome, increasing the likelihood of complications, didn’t make sense. As well, repeated retrieval of retained lens material from the retinal surface increased the risk of iatrogenic retinal injury. She wondered: “Wouldn’t it be so much easier if we could hold on to the lens material, rather than chasing it?” Retina colleagues from around the world – including Dr. Srinivasan in India, Dr. Mura in Saudi Arabia and others – had also been searching for a similar solution and a better way to address retained dislocated cataract material. Great minds must think alike!
As the saying goes, necessity is the mother of invention – and apparently having a family member with insight into urology techniques doesn’t hurt either. For years, Dr. Fekrat had been talking about designing a solution to this problem when a close family member (a urologist), finally mentioned, “Oh yes, we’ve been using a basket like that to retrieve kidney stones through the urethra for ages.” Her reply was a combination of joy and exasperation: “Where have you been all my life?!”
Dr. Fekrat and her colleagues Dr. Duncan Berry and Dr. Scott Walter repurposed a 1.5 French N-Circle Nitinol Tipless Stone Extractor (Cook Medical, Bloomington, IN) from the urology operating room. With the basket retracted, the external guidewire fits easily through a 23-gauge valved cannula and the extendible basket, controlled by an external handpiece, expands to a 1 cm diameter, large enough to accommodate the entire crystalline lens. “Despite being a urologic instrument, the Frag Bag is surprisingly well suited to intraocular use,” explained Dr. Walter.
The team at Duke recently published this novel technique in a recent issue of Ophthalmic Surgery, Lasers & Imaging Retina. The report includes a case of an 80-year-old who had posterior capsule rupture with loss of a large nuclear fragment and the Fekrat Frag Bag, as it is sometimes called, was used to remove it. The preoperative visual acuity was 20/100 and after one month was 20/40 with an attached retina and no macular edema. There were no intraoperative or postoperative complications.
The team at Duke has continued to use the technique and are excited to see the Frag Bag extractor further modified to be even more user friendly for retina surgery. “The instrument enhances surgeon control, allowing simultaneous stabilization and softening of the lens nucleus with an adjustable snare,” added Dr. Walter. The response from the vitreoretinal community has been overwhelmingly positive. The video, Frag Bag: A Novel Technique For Removal of Retained Lens Material, was presented at the 2017 ASRS Film Festival, where it received the prestigious Rhett Buckler Award and was featured as an AAO Editors Choice Video.
Reference:
Berry DE, Walter SD, Fekrat S. A Frag Bag for Efficient Removal of Dislocated Nuclear Material. Ophthalmic Surg Lasers Imaging Retina. 2017;48(12):1006-1008.
