Article Date: 10/1/2010

A New Paradigm: Shifting to MIVS for Complex Cases
ADVANCEMENTS IN SURGICAL TECHNOLOGY AND EFFICIENCY

A New Paradigm: Shifting to MIVS for Complex Cases

BY MARIA H. BERROCAL, MD

I believe the CONSTELLATION® Vision System together with micro-incision vitrectomy surgery (MIVS) will be the impetus behind a paradigm shift in how we approach complex vitrectomies. In the past, we saw MIVS as ideal only for simple cases. Now, however, with the new features introduced in the CONSTELLATION® System, I believe micro-incision surgery is safe, efficient and optimal for more complex cases.

OPTIMAL FEATURES FOR COMPLEX CASES

I have found the CONSTELLATION® Vision System provides efficient vitreous removal, minimal traction on the detached retina — something that was unthinkable with the previous technology — and safe shaving of the vitreous base. In complex tractional retinal detachments or proliferative vitreoretinopathy (PVR), MIVS with the CONSTELLATION® System has a number of advantages. The port is located closer to the tip of the cutter, so we can get under membranes and use it as a pick, an aspirator or a forceps, and because it is small, we can easily maneuver around membranes.

The ULTRAVIT® high-speed cutter (5,000 cuts per minute) with duty cycle control reduces traction when shaving membranes from the vitreous base. The need for ancillary instruments is reduced, so we are not moving our instruments in and out of the eye in these complex cases. For this reason, we have fewer sclerotomy tears and less vitreous incarceration. In addition, with the CONSTELLATION® System's integrated pressurized infusion with IOP Compensation, we no longer need to keep pressures at very high levels to control bleeding. Therefore, inflammation is reduced and wound problems are minimized.

The CONSTELLATION® Vision System's standard illumination probe is excellent, but the system also has a sapphire wide-angle endoilluminator, which gives a broader view of the entire retina as we are working. This is particularly useful in eyes that have pathology in the far periphery.

Previously, we could not manipulate the globe with 25-gauge, because the instruments were too flexible. With the new 25+ system, we can move the globe around easily to see the periphery and also to perform scleral depression.

Another unique feature is the proportional reflux, which allows us to sweep blood off the retina and then aspirate, all without having to change instruments. This can be done with the vitreous cutter or with a flute-needle. This is what I mean when I say we can do complex cases in a seamless, smooth manner, using mostly the vitreous cutter, and activating all modalities with the foot pedal. The proportional diathermy allows us to graduate the intensity with the foot pedal in a sequential manner.

Returning to 25-Gauge
I started using 25-gauge several years ago when it was first introduced, but I soon switched to 23-gauge because we did not have the optimal machines to use 25-gauge properly. The technology simply was not there.
I have started using the 25+, and every day, I do more cases with 25+ because I think it has some distinct advantages. With the smaller gauge size and the port closer to the tip, I have more control and can be more precise, particularly in complex cases. I can safely peel membranes from the surface of a detached retina and from blood vessels.
I would encourage any surgeon who abandoned 25-gauge in the past to try it again. I think you will be pleasantly surprised with this advanced technology.

CONCLUSION

The CONSTELLATION® Vision System is ideal for micro-incision surgery in complex cases. This machine essentially erases vitreous, without significant movement of the retina underneath.

This system was created to address all of the issues we had with micro-incision surgery in the past. With its ultrahigh cut rate, duty cycle control, IOP compensation, improved lighting and improved trocar entry system, the CONSTELLATION® System provides a platform that has the potential to significantly improve our outcomes and efficiency. In addition, the surgeon-controlled modalities help reduce errors and allow us to work with various personnel. Essentially, this system provides us with safety, beautiful control and efficiency in all gauges.


Maria H. Berrocal, MD, is a professor at the University of Puerto Rico School of Medicine and practices in San Juan.

CASE EXAMPLES BY MARIA H. BERROCAL, MD
CASE 1: Combined tractional rhegmatogenous retinal detachment in a diabetic patient. Using the 25+ for a tractional retinal detachment, I can remove thick blood clots efficiently, something that was not possible with the previous vitrectomy systems. The probe is so small, it can get under the membranes so you can dissect them. You can shave them from the surface of the retina in much the same way you would use vertical scissors. You can almost peel them from blood vessels.
In a recent case (Figures 1a and 1b), I created a space to lift the fibrovascular membrane, which allowed me to remove it with the cutter. I was able to get very close to the retina with almost no movement, which was unthinkable with our previous technology. After removing the tissue, which was quite thick, I applied diathermy to the breaks, performed fluid-air exchange and applied photocoagulation. A nice feature of the laser is that you can control the intensity of the burns with the foot pedal. This type of case can be done efficiently with minimal complications. The IOP control prevents bleeding from a drop in IOP during instrument exchanges. In the past, we would have had to perform a complicated procedure with a multitude of different instruments.



Combined traction and rhegmatogenous retinal detachment 25g removal of membranes.



CASE 2: Proliferative vitreoretinopathy. I treated a PVR case with some fairly thick membranes (Figures 2a and 2b). I injected perfluorocarbon liquid and then peeled the membranes through the perfluorocarbon to stabilize the retina to the periphery. With the smaller probes, we can safely shave the membranes from the surface of the retina, getting quite close. In the past, we probably would have performed this maneuver with scissors.



Retinal detachment with PVR.



Membrane removal with vitrector.



CASE 3: Total rhegmatogenous retinal detachment. I frequently combine scleral buckling with small-gauge vitrectomy. In a recent case of total rhegmatogenous retinal detachment (Figures 3a and 3b), I first did the scleral buckle and then removed the vitreous from the periphery with minimal traction on the retina. The creation of iatrogenic breaks is markedly reduced with this technology. I injected perfluorocarbon liquid and aspirated subretinal fluid. I like to aspirate often with the vitrectomy probe through the break. Next, I applied laser photocoagulation to the break. With the flexible tip laser probe, I find I can treat that entire area in an elegant, quick way, even in phakic


Rhegmatogenous retinal detachment.



Bidirectional laser to breaks.


CASE 4: Tractional detachment in silicone-filled eye. Silicone oil removal and injection can be done beautifully through small gauge with the CONSTELLATION® System. In this case, I entered through the limbus to remove droplets of emulsified silicone oil from the anterior chamber (Figure 4a). Then, I used forceps to lift the membrane that was causing the tractional detachment (Figure 4b). After lifting off the membrane, I was able to remove everything with the cutter (Figure 4c). I still utilize forceps in some cases, but I use them less often with this technology.



Removal of silicone droplets in anterior chamber with cutter.



Removal of membranes.



Final view.

CASE 5: Severe PVR with subretinal membranes. In this case, the eye was filled with silicone oil. The eye already had several surgeries, but the conjunctiva looked good. I removed the oil (Figure 5a) and then went under the retina to remove large sheets of subretinal membrane that had collected all the way around (Figures 5b and 5c). While doing this case, I was impressed with the lighting on the CONSTELLATION® System and how well I could visualize tissue at all times.
I performed a fluid-air exchange and aspirated with the same probe through the retinotomies. After applying laser to the breaks, I injected silicone oil. I performed all of these maneuvers in a smooth, seamless, efficient manner with minimal exchange of instruments and with total IOP control throughout.
These few cases represent the many complex pathologies that can be treated using the CONSTELLATION® Vision System.



Total recurrent retinal detachment with subretinal membranes, oil removal.



Subretinal membrane removal.



After membrane removal.


Retinal Physician, Issue: October 2010