Refractory MH remains challenging for vitreoretinal surgeons and may progress to MHRD, which is a vision-threatening complication. Several methods, including extended ILM peeling, autologous free ILM flap transplantation, lens capsular flap transplantation, subretinal balanced salt solution injection to create macular detachment, and revitrectomy with autologous platelet concentrate (APC)/whole blood and gas tamponade, have been reported for refractory MH repair [5, 8, 9]. All these methods facilitate the closure of most MHs. However, a few patients still have a persistent MH even after multiple surgeries, and a free ILM flap may not be available. Furthermore, a lens capsular flap cannot be harvested in pseudophakic patients. Therefore, neurosensory retinal free flap transplantation becomes a reasonable and feasible method for the repair of a refractory MH.
Grewal and Mahmoud reported a novel method for the treatment of refractory MH with an autologous neurosensory retinal free flap with a 2-disc diameter under PFC assistance and silicone oil tamponade [7]. Parolini et al. then introduced another method involving an autologous choroid-retinal pigment epithelium-neurosensory retinal graft to treat end-stage exudative age-related macular degeneration [10]. Both methods provide potential surgical alternatives for the treatment of refractory MH. In the technique, the surgeons use both PFC and silicone oil to stabilize the retinal free flap. However, the stability of the transplanted retinal flap after removal of the silicone oil is unknown. Recurrent neurosensory retinal flap dislocation may occur.
Purtskhvanidze et al. reported the use of APC or whole blood with gas tamponade for refractory MH repair [8]. In their report, revitrectomy with whole blood and gas achieved a lower closure rate than that with APC and gas (7.1% versus 85.2%, respectively). In addition, the retinal free flap was noted on OCT (Fig. 2b). Therefore, we speculate that closure of the refractory MH in this case was not from the effect of whole blood.
Whole blood contains serum, coagulants, albumin, and globulin and can be prepared as blood glue [11]. Therefore, it is reasonable to use whole blood as an adhesive to fix a neurosensory retinal free flap at a MH under gas tamponade. However, the relatively large size (2 disc diameters) of the retinal free flap may result in neurosensory retinal overlap. Therefore, we modified the size to 2 MH diameters to prevent neurosensory retinal overlap. Similar to the case reported by Grewal and Mahmoud, the restoration of retinal stratification with a corresponding increase in BCVA suggests that the autologous neurosensory retinal free flap may partially maintain retinal function in addition to acting as a scaffold for glial cell proliferation.
There are still several limitations to this technique. First, the most appropriate size of the neurosensory retinal free flap remains unclear since the free flap may contract after implantation into the MH. Second, due to the limited number of cases and relatively short follow-up times, the long-term outcomes and possible complications are unknown. We would like to emphasize that harvesting a neurosensory retinal free flap for transplantation remains the last resort in difficult cases to repair refractory MHs that fail to close after repeated surgeries. Third, a better adhesive or tissue glue for the fixation of the retinal free flap may improve the outcome. Additional experience may help refine the technique and clarify the anatomical and functional results.
