Cochlear implantation standards – Results of a survey

Abstract

Results One-hundred and twenty-one responses were recorded, coming from 43 nations in the 5 continents (Fig. 1). Sixty-two otologists (53%) have considerable experience, each having performed more than 100 implantation surgeries. This experienced group of surgeons perform most of the bilateral and sequential operations (P< 0.01 and P< 0.05, respectively). Single-stage bilateral CI surgery is preferred by 54% of surgeons. CI in SSD is seldom performed. Implantation of electric-acoustic stimulation devices is performed by 37% of the respondents. Senior surgeons are more often involved in implantation surgery at extreme ages (P< 0.001). Significant changes in the surgical procedure are recommended for very young children (P< 0.05). No changes in the standard implantation procedure are recommended for the elderly. In the routine radiological assessment of the temporal bone, plain X-rays are performed by 2% of respondents preoperatively and 68% postoperatively. Computed tomography is performed by 91% preoperatively and 12% postoperatively. Seventy-four per cent of surgeons routinely obtain magnetic resonance preoperatively. These results did not vary by the surgeon group. Thirty-five per cent of surgeons are of the opinion that the type and shape of the electrode array, and the insertion technique, can significantly influence CI outcomes. Opinions were expressed about electrode array shape (n= 15), length (n= 14), depth of insertion (n= 11), best technique to preserve residual hearing (n= 10), and position of contacts (n= 8) (Fig. 2). Sixty-four per cent of surgeons always use facial nerve monitoring. Fifteen per cent of surgeons utilize facial nerve monitoring only in selected cases. Almost all surgeons use antibiotic prophylaxis perioperatively (96%). Custom-made instruments are present in 39% of CI surgical kits. Half of the respondents pay attention to a cosmetic hair shave. A small skin incision is preferred (55%) to a standard incision (20%). Minimally invasive incisions are also common (24%). Young surgeons rely more often than senior surgeons on a traditional skin incision with a posterior extension over the receiverstimulator area (P< 0.001). Fifty-five per cent of surgeons utilize a bilayer flap while 40% use a full thickness flap. Mastoidectomy and posterior tympanotomy are preferred by 95% of the respondents. The insertion of the array through the round window (65%) is favoured over a promontory cochleostomy (35%) and is generally preferred by more experienced surgeons (P< 0.05). Half of the respondents, and more often senior surgeons (P< 0.001), rely on soft insertion techniques (Fig. 3). The receiver-stimulator is secured by sutures passed through bone (40%) or periosteum (30%), screws (9%), or by other techniques (23%) (Fig. 4). Correspondence to: Enrico Muzzi, MD Audiology and ENT Unit, Department of Pediatrics, Institute for Maternal and Child Health – IRCCS “Burlo Garofolo”, Via dell’Istria 65/1, 34137 Trieste, Italy. Email: enrico.muzzi@burlo.trieste.it, enr.muz@gmail.com