Staged implantation of active transcutaneous bone conduction hearing devices (BCHD) after explantation of older generation bone anchored hearing aids (BAHAs): Surgical outcomes and approach to management.

PURPOSE: To evaluate outcomes following explantation of percutaneous or transcutaneous bone conduction implants (pBCIs or tBCIs) and subsequent implantation of transcutaneous active bone conduction hearing devices (BCHDs); to provide guidance regarding staging of surgery and adjunctive procedures. MATERIALS AND METHODS: Retrospective chart review of eight adult subjects (ten ears) with pBCIs or tBCIs who underwent explantation of their device and subsequent implantation with a BCHD [MED-EL BONEBRIDGE™ (n = 7, 70 %) or Cochlear™ Osia® (n = 3, 30 %)]. RESULTS: Reasons for pBCI or tBCI explantation were pain (60 %, 6/10), infection (60 %, 6/10), skin overgrowth (50 %, 5/10), and inability to obtain new processors (20 %, 2/10). Median time between pBCI or tBCI removal and BCHD staged implant was 4.7 (IQR 2.2-8.1) months. Two subjects developed complications following BCHD implantation. One had a persistent wound overlying the osseointegrated screw after removal of the pBCI abutment, requiring removal and temporalis rotational flap. Staged Osia® implantation was performed, but ultimately wound dehiscence developed over the device. The second subject experienced an infection after BONEBRIDGE™ implantation (32 days after pBCI explant), necessitating washout and treatment with intravenous antibiotics. There was subsequent device failure. CONCLUSION: The transition from a pBCI or tBCI to a novel transcutaneous device is nuanced. Staged pBCI or tBCI explantation and novel BCHD implantation with sufficient time for wound healing is vital. Adjunctive procedures to augment soft tissue in cases of prior attenuation may be required to avoid complications with larger internal devices.

Epidemiology and Risk Factors for Development of Sporadic Vestibular Schwannoma.

Vestibular schwannomas (VSs) are benign, slow-growing tumors of the eighth cranial nerve. Sporadic unilateral VSs constitute approximately 95% of all newly diagnosed tumors. There is little known about risk factors for developing sporadic unilateral VS. Potential risk factors that have been reported are familial or genetic risk, noise exposure, cell phone use, and ionizing radiation, whereas protective factors may include smoking and aspirin use. More research is needed to elucidate the risk factors for development of these rare tumors.

Immune Correlates of Disease Progression in Linked HIV-1 Infection.

Genetic and immunologic analyses of epidemiologically-linked HIV transmission enable insights into the impact of immune responses on clinical outcomes. Human vaccine trials and animal studies of HIV-1 infection have suggested immune correlates of protection; however, their role in natural infection in terms of protection from disease progression is mostly unknown. Four HIV-1+ Cameroonian individuals, three of them epidemiologically-linked in a polygamous heterosexual relationship and one incidence-matched case, were studied over 15 years for heterologous and cross-neutralizing antibody responses, antibody binding, IgA/IgG levels, antibody-dependent cellular cytotoxicity (ADCC) against cells expressing wild-type or CD4-bound Env, viral evolution, Env epitopes, and host factors including HLA-I alleles. Despite viral infection with related strains, the members of the transmission cluster experienced contrasting clinical outcomes including cases of rapid progression and long-term non-progression in the absence of strongly protective HLA-I or CCR5Δ32 alleles. Slower progression and higher CD4/CD8 ratios were associated with enhanced IgG antibody binding to native Env and stronger V1V2 antibody binding responses in the presence of viruses with residue K169 in V2. ADCC against cells expressing Env in the CD4-bound conformation in combination with low Env-specific IgA/IgG ratios correlated with better clinical outcome. This data set highlights for the first time that V1V2-directed antibody responses and ADCC against cells expressing open, CD4-exposed Env, in the presence of low plasma IgA/IgG ratios, can correlate with clinical outcome in natural infection. These parameters are comparable to the major correlates of protection, identified post-hoc in the RV144 vaccine trial; thus, they may also modulate the rate of clinical progression once infected. The findings illustrate the potential of immune correlate analysis in natural infection to guide vaccine development.