Abstract
Sudden sensorineural hearing loss following non-otologic surgery is a rare event described in the medical literature. Cardiopulmonary bypass surgery is most commonly associated with this type of hearing loss. Our case report and review of the literature describe two cases with postoperative hearing loss – neither of which are cardiac surgeries – making them exceedingly rare in the medical literature. Regardless of the rarity of this unfortunate event, the possibility for permanent hearing loss is a potentially devastating unanticipated complication and one that all surgeons should be aware.
1
Objective
Sudden sensorineural hearing loss (SNHL) in the post-operative setting has been reported to occur after many different types of non-otologic surgical interventions. Reported cases involve such a diversity of surgical procedures that the exact mechanism(s) by which SNHL occurs is often unclear. There are two categories of surgery that are most commonly related to reports of SNHL in the literature: cardiopulmonary bypass (CPB) surgery and procedures associated with a loss of cerebrospinal fluid (CSF). This report adds to the literature two more cases of SNHL after non-otologic surgery, one of which has previously unreported bilateral involvement, and reviews the literature to postulate mechanisms by which SNHL in this setting might occur.
2
Patients
2.1
Case #1
A 44-year-old female with no prior history of hearing loss underwent a total abdominal hysterectomy and an anterior and posterior repair with abdominoplasty in a combined 10-h surgery with a total blood loss of 700 ml. She noticed significant hearing loss in the right ear the morning after surgery. Her neurologic exam was otherwise normal. An audiogram was first performed three days after surgery by a referring physician demonstrating a severe-to-profound, down-sloping, high frequency predominant right ear SNHL with normal hearing in the left ear. She first presented to our clinic three weeks postoperatively for evaluation and received three .5 cc intratympanic dexamethasone injections over the course of three weeks. Her initial and 18 month postoperative audiograms from our clinic are shown in Fig. 1 showing no significant return of hearing in the right ear. Head and temporal bone MRI and CT scans were normal.
2.2
Case #2
A 63-year-old male underwent a left retrosigmoid craniotomy with microvascular decompression of the trigeminal nerve in the semi-sitting position for intractable trigeminal neuralgia. No known ototoxic medications were given perioperatively. Intra-operative bilateral auditory brainstem response (ABR) monitoring remained stable throughout the course of this two and a half hour procedure.
The day after surgery, the patient reported severe bilateral hearing loss. His neurotologic exam was normal. His preoperative audiogram and those performed on postoperative days (POD) 1, 3 and 10 are compared in Fig. 2 , showing a slowly resolving severe, flat bilateral SNHL. A review of all available MRI and CT scans demonstrated normal labyrinthine, cochlear aqueduct, and vestibular aqueduct anatomy.
2
Patients
2.1
Case #1
A 44-year-old female with no prior history of hearing loss underwent a total abdominal hysterectomy and an anterior and posterior repair with abdominoplasty in a combined 10-h surgery with a total blood loss of 700 ml. She noticed significant hearing loss in the right ear the morning after surgery. Her neurologic exam was otherwise normal. An audiogram was first performed three days after surgery by a referring physician demonstrating a severe-to-profound, down-sloping, high frequency predominant right ear SNHL with normal hearing in the left ear. She first presented to our clinic three weeks postoperatively for evaluation and received three .5 cc intratympanic dexamethasone injections over the course of three weeks. Her initial and 18 month postoperative audiograms from our clinic are shown in Fig. 1 showing no significant return of hearing in the right ear. Head and temporal bone MRI and CT scans were normal.
