Background: The subtotal petrosectomy procedure may be useful for cochlear implantation in selected patient groups. Although it is highly effective, complications can arise, which may have economic implications for the patient due to the high cost of the device. Therefore, several authors have attempted to identify the most effective concept for obliteration. Methods: We present a pilot descriptive study of application techniques for obliterating cavities after subtotal petrosectomy using a temporoparietal fascial flap (TPFF) modified with injectable platelet-rich fibrin (IPRF+) for three cochlear implant (CI) patients. Results: Our concept preserves important anatomical structures, such as the temporalis muscle, which covers the CI receiver–stimulator. Injection of IPRF+ also increases the available tissue volume for obliteration and enhances its anti-inflammatory and regenerative potential. Conclusions: To the best of our knowledge, the use of TPFF for filling the cavity has not been adopted for CI with SP and for blind sac closure. Our literature review and our experience with this small group of patients suggest that this procedure, when combined with IPRF+ injections, may reduce the risk of potential infection in the obliterated cavity, particularly when used with CI. This technique is applicable only in cases when the surgeons are convinced that the middle ear cavity is purged of cholesteatoma.