Commentary: Use of phacofragmentome to remove thick organized blood clots.

Diabetic vitrectomy is one of the most complicated vitreoretinal surgeries as it is associated with multiple intraoperative challenges and surprises. One such challenge is the management of the organized blood clots that are hard and rubbery in consistency. It is a tedious job to remove these clots with the vitrector and may take a long time. The process can cause damage to the various ocular structures as well as the instrument(s) due to the prolonged and multiple manipulations.

We congratulate the authors for describing their technique of using ultrasonic fragmentation to remove these thick organized blood clots.[1] The phacofragmatome is usually used to emulsify the nucleus in the vitreous cavity. The luminal diameter of a 20G phacofragmatome is nearly 4 times larger than the lumen of a 25G vitrector.[2] This enhances the flow and followability of the nuclear material into the fragmatome. Similarly, the ultrasonic energy can be used to fragment the organized blood clots into small pieces with lesser manipulations and makes the process quick, efficient, less traumatic, and less prone to intraoperative complications.

We have been using a similar technique to remove the subretinal blood clots from the eyes with age-related macular degeneration and polypoidal choroidal vasculopathy. A combination 23G and 20G instruments are used. Initially, three 23G sclerostomises are made. Core vitrectomy is followed by induction of posterior vitreous detachment till the periphery with the help of triamcinolone. The peripheral vitreous is trimmed, and nearly 180° peripheral retina is diathermized and incised with the vitrector. The retina is then folded posteriorly to expose the subretinal space, and the subretinal blood clot is removed using the suction of a vitrector. Perfluorocarbon liquid is injected to stabilize the retina and float the blood clot to mid-vitreous cavity. One 23G sclerostomy is then replaced with 20G sclerostomy after localized conjunctival peritomy. The blood clot is then removed with the help of a fragmatome. Similar technique has also been described by Chen et al.[3] Other uses of a fragmatome include the removal of intraocular lens and nonmetallic foreign body without the use of intraocular forceps or other grasping instruments.[4] It is imperative to mention that a thorough vitrectomy is necessary before introducing the phacofragmatome into the vitreous cavity as aspiration of the peripheral vitreous into the phacofragmatome can lead to iatrogenic retinal break(s) and consequent retinal detachment.

The microincisional vitrectomy surgery (MIVS) and narrow-gauge instruments have multiple advantages over the traditional 20G surgery. They are associated with better patient comfort, decreased postoperative inflammation, and decreased incidence of sclerotomy-related retinal breaks. However, the efficiency of vitreous removal is reduced. Hybrid vitrectomy is used to tackle the situations where a wider gauge instrument is required during the surgery, like fragmatome for dropped nucleus, scissors for diabetic tractional retinal detachment, forceps for intraocular foreign body removal.[567]

Hybrid-gauge vitrectomy refers to the use of multiple different gauge sclerotomies. Similarly, mixed-gauge vitrectomy is also performed. It refers to the use of narrower gauge instruments through wider gauge cannulas. A standardized nomenclature has been proposed to specify the gauges in hybrid- and mixed-gauge MIVS. The first number refers to the gauge of the ancillary instrument(s), and the second number refers to the gauge of the infusion system. For example, hybrid 20/25G vitrectomy refers to the use of a 20-G instrument (like fragmatome) along with a 25G infusion line. Similarly, mixed 25/23G vitrectomy refers to the use of 25G instrument(s) through a 23G cannula.[7]

One of the major problems encountered during hybrid vitrectomy is the infusion inflow/outflow mismatch, which can lead to hypotony, retinal breaks, retinal detachment, and choroidal detachment. This happens because the infusion cannula is smaller than the outflow cannulas. To compensate this inflow/outflow mismatch, the infusion pressure during the surgery should be fixed at a high level.[7]

The authors also described the use of a 20/25G hybrid vitrectomy for removing the organized blood clots during diabetic vitrectomy.[1] Hybrid vitrectomy combines the best of both the worlds and expands the surgeon’s armamentarium while dealing with complex vitreoretinal cases.