Endoresection of large uveal melanoma conserves the eye, vision

With tumors exceeding 9 mm, other types of conservative therapy are not recommended, but internal resection may prevent the need for enucleation.

TAORMINA, Italy — Endoresection may be an effective conservative treatment of large posterior choroidal melanomas, according to a study presented here at the Jules Gonin Club meeting by José Garcia-Arumi, MD, of Barcelona University.

“When the tumor thickness exceeds 9 mm, other forms of conservative treatment are likely to cause severe ocular complications, and enucleation is the choice of most ophthalmologists,” Dr. Garcia-Arumi said. “In our study, we evaluated the safety and efficacy of internal resection and obtained very encouraging results. All 25 of our patients retained their eyes, and most had functional success.”

In young patients, tumors grow faster

The mean age of the 25 patients entering the study was 41 years, younger than the general population with choroidal melanoma, of which the mean age of diagnosis is 55 years. In this young population, the tumor grows faster growing and quickly invades Bruch’s membrane and sometimes the retina. In most cases, it is also thicker than average.

“In our study, we included patients with tumor thickness greater than 9 mm, base diameter less than 15 mm, anterior margin not exceeding the equatorial area and absence of metastatic disease. Preoperative best-corrected visual acuity levels ranged from 20/400 to 20/20 (mean: 20/60). The mean tumor thickness was 10.6 mm, and the mean maximum diameter was 12.1 mm. In each case, the choroidal melanoma had invaded Bruch’s membrane and assumed a mushroom shape. In 11 cases, the tumor infiltrated the retina. Each patient had an exudative retinal detachment,” Dr. Garcia-Arumi explained.

A 43-year-old man with a juxtamacular choroidal melanoma. The tumor measured 11.1 mm in thickness by 12.5 mm in basal diameter. Visual acuity before surgery was 20/100.	Fluorescein angiography.

Surgical maneuvers

Surgical technique varied depending on the degree of retinal involvement. If the tumor had not invaded the retina, a vitrectomy with a panoramic viewing system (a 130º precorneal lens) was performed, followed by posterior hyaloid dissection, 120º anterior retinotomy and 810-nm diode laser endophotocoagulation 2 mm beyond the tumor margins using the continuous mode of the laser and 600 to 800 mW. Laser photocoagulation was followed by removal of the melanoma with the vitrectomy probe using a bimanual technique.

“The retina was lifted with forceps and held away from the vitrectomy probe. When the intraocular pressure (IOP) reached 50 to 60 mm Hg, tumor excision began at the tumoral apex, until the scleral bed inside the circle delineated by the laser was free of tumor tissue. The cellular remnants at the scleral bed were photocoagulated with the endodiode laser probe. Laser retinopexy endophotocoagulation was performed at the limit of the retinotomy, followed by fluid-air exchange and silicone oil-air exchange,” Dr. Garcia-Arumi said.

If the tumor had invaded the retina, the diode laser was applied through the retina, and the retina and tumor were removed together. Adjunctive Ru106 plaque radiotherapy was applied to the episclera at the tumor base when unresectable tumor remnants adhered to the scleral bed. The vitrectomy specimens were sent for pathologic evaluation.

Fundus photograph 1 week after surgery, with silicone oil filling the vitreous cavity.

One month after silicone oil removal. Because the retina was not invaded by the tumor, a peripheral retinotomy was performed, and the inferotemporal retina was detached, creating a retinal flap; the tumor was resected under the retinal flap, and the retina was reattached. The inferotemporal vascular arcade is seen crossing over the resected tumoral area. The patient’s visual acuity still remains 20/200 24 months after surgery.

Successful tumor removal

Patients were instructed to maintain a facedown position for 1 week postoperatively. They were reviewed after 1 week, 1 month and 3 months and then every 6 months for 5 years. Screening for metastasis was performed every 6 months. Mean follow-up was 31 months.

“In all cases, we were able to remove the tumor totally. Increasing the IOP, we controlled the intraoperative choroidal bleeding at the borders of the resected tumor. In 14 patients, a peripheral retinotomy was performed, and the tumor was removed under a retinal flap. In 11 patients, the infiltrated retina and the tumor were removed together. In two patients, adjunctive Ru106 plaque radiotherapy was necessary. Histologic evidence of malignancy was unequivocal in the 25 tumors,” Dr. Garcia-Arumi said.

At the final visit, the 25 patients still retained their eyes. The final visual acuity levels ranged between hand motions and 20/30.

---Preoperative fundus of the right eye of a 35-year-old woman. A high temporal choroidal melanoma can be observed.	Preoperative fluorescein angiography.

Complications

The main postoperative complications were bleeding at the scleral bed (100%), cataract (40%), ocular hypertension (32%), retinal detachment (16%), macular traction produced by the chorioretinal scarring at the limits of the resected area (16%), epiretinal macular proliferation (8%), branch vein occlusion (4%) and submacular hemorrhage (4%).

“The causes of the retinal detachment were inadequate retinopexy around the colobomatous area (two cases), entry site tears (one case) and a retinal break in the peripheral inferior retina far from the resected area. The retinal detachment appeared following silicone oil removal in three cases, and 6 months after silicone oil removal in one case,” Dr. Garcia-Arumi explained.

Retinal detachment surgery was successfully performed in the four cases.

Cataract occurred in 10 patients (40%), mostly as a result of the use of silicone oil. Phacoemulsification with foldable IOL implantation was performed without complications about 12 months after silicone oil removal.

In two patients, an epiretinal proliferation involving the macular area was observed 6 and 9 months after the surgery. Because decreased visual acuity and metamorphopsia were observed, vitreoretinal surgery with membrane removal was performed.

In one patient with a juxtapapillary nasal melanoma, a submacular hemorrhage was observed in the postoperative period. The hemorrhage resolved in 1 month, and the patient achieved 20/60 vision after 6 months of follow-up.

“Neither local recurrences nor metastatic complications were observed by the end of the study, and this is, of course, very encouraging,” Dr. Garcia-Arumi said. “However, our follow-up is too short to comment on local tumor control and metastasis, and it is inevitable that these complications will eventually occur in some patients, as with any other form of conservative treatment. Our preliminary results, however, appear to be no worse than those achieved with other treatment modalities.”

Postoperative fundus after silicone oil removal with temporal chorioretinal atrophy and conservation of the rest of the structures.	Superior choroidal melanoma with rupture of Bruch’s membrane.

Minimizing the risk of metastasis

“Although recent studies do not support the opinion that surgical manipulation of malignant uveal melanoma promotes metastases, we adopted some surgical measures to minimize the risk of local recurrence and metastasis,” Dr. Garcia-Arumi said.

Before tumor resection, 810-nm diode laser endophotocoagulation was applied 2 mm beyond the tumor margins to close the tumor feeding vessels and decrease the risk of hematogenous dissemination and bleeding during the removal of the melanoma. “We blocked choroidal circulation by increasing the IOP and applied diode laser photocoagulation to the bed of the coloboma to destroy residual tumor cells,” he explained.

Fluid-air exchange was performed after tumor removal to eliminate residual cells in the vitreous cavity. The IOP was lowered when removing instruments, and the conjunctiva and sclera were examined and washed after the procedure to eliminate any seeded cells.

“The use of a panoramic viewing system was helpful in controlling the whole tumor during resection, repositioning the retinal flap after tumor removal, applying laser retinopexy and providing good visualization during PFL-air exchange. When the tumor was resected under a retinal flap, a bimanual technique was used. One hand held the retina away from the tumor with a microsurgical forceps, while the other resected the tumor with the vitrectomy probe. The everted retina was very mobile, and this maneuver lowered the risk of retinal damage during tumor resection. This technique warrants further study and investigation and requires a well-trained vitreoretinal surgeon,” Dr. Garcia-Arumi said.

Fluorescein angiography showing the limit of the retinal vessels and the tumor in contact with the vitreous cavity.	Postoperative appearance of the fundus. The limit of tumor resection is clearly demarcated.

For Your Information:

• José Garcia-Arumi, MD, can be reached at Instituto de Microcirurgia Ocular, C/Munner n.10, 08022 Barcelona, Spain; (34) 93-2531500; fax: (34) 93-4161131; e-mail: 17215jga@comb.es. Dr. Garcia-Arumi has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.