Episodic attacks of vertigo with hearing loss, tinnitus, and aural fullness all characterize Meniere’s disease. Vertigo is the most disabling symptom of Meniere’s disease; initial therapy consists of medical management with diuretics and low salt diet that controls dizziness in approximately 70 percent to 95 percent of Meniere’s disease patients. Those who fail this therapy, or are unhappy with their level of vertigo control, are candidates for surgery, a more aggressive therapy.
Today, the most commonly performed surgical operations for control of vertigo in Meniere’s patients are: endolymphatic mastoid shunts (EMS) operation, vestibular neurectomy, and labyrinthectomy. EMS, a procedure that establishes communication between the endolymphatic sac and the cerebrospinal fluid space, is a conservative option because hearing is preserved and surgery is generally performed on an outpatient basis. Vestibular neurectomy, a cutting across of the vestibular division of the eighth cranial nerve, also preserves hearing but requires a craniotomy (opening the skull and brain covering) and is generally only offered to patients with disease confined to one ear. These procedures can result in the elimination of vertigo in many patients, and substantial vertigo improvement has been is seen in 95 percent of patients. Labyrinthectomy (TLL), removal of the labyrinth, should only be performed for disease in one ear and has vertigo control rates of approximately 95 percent.
Another option is the use of ototoxic (toxic to the ear) antibiotics designed to destroy vestibular function of the inner ear. Antibiotics such as streptomycin, neomycin, and gentamicin, have been used for this purpose in the treatment of Meniere’s disease since the late 1940’s. Gentamicin is the antibiotic most widely used, specifically through transtympanic injection into the middle ear. The medication is absorbed through the round window and moves into the inner ear where it destroys selected areas of the vestibular apparatus. Gentamicin therapy is an outpatient procedure with a reported success rate of 84 percent in elimination of vertigo with some authors reporting 100 percent improvement of vertigo. Hearing loss is seen in approximately 30 percent of patients, but it is unclear whether this is the result of the therapy or the natural history of the disease.
Transtympanic gentamicin injection is becoming the standard management for medically refractory, i.e. resistant to treatment Meniere’s disease. A team of otologists set out to review various surgical therapies and their relevance as a viable treatment. This retrospective research reports on the results of three surgeries – endolymphatic mastoid shunt (EMS), sub-occipital vestibular nerve section (SOVN), and translabyrinthine labyrinthectomy (TLL), at an otology clinic. The authors of “Surgical Management of Meniere ’s Disease in the Era of Gentamicin,” are David M. Kaylie MD, C. Gary Jackson MD, and Edward K. Gardner MD, all with The Otology Group, Nashville, TN. Their findings are being presented as a poster/paper study at the 107th meeting of The Triological Society http://www.triological.org, being held April 30 - May 3, 2004, at the JW Marriott Desert Ridge Resort & Spa, Phoenix, AZ.
A retrospective chart review was performed for all patients who underwent surgical procedures for translabyrinthine labyrinthectomies, suboccipital vestibular nerve sections and endolymphatic mastoid shunts between 1995 and 2001. A total of 229 surgical procedures were performed for definite Meniere’s disease; 189 patients had sufficient data for review. Patients with bilateral Meniere’s at the time of surgery were excluded from the study; subjects’ mean age at time of surgery was 50.5 years old, ranging from 13.3 to 84.1 years old. Sixty-six patients were male (35 percent) and 123 (65 percent) were female.
Thirty-two patients had translabyrinthine labyrinthectomies (TLL), 83 underwent suboccipital vestibular nerve sections (SOVNS), and 74 elected for an endolymphatic mastoid shunt (EMS). Hearing results, dizziness classification, and functional level score were determined from patient charts and telephone conversations.
These results show that surgery is still a viable option for management of medically refractory Meniere’s disease. The vertigo control rates after shunt surgery were lower than the other surgical options and gentamicin therapy, but had very low acute hearing loss and complication rates. Vestibular nerve section had comparable vertigo control rates to gentamicin, but had fewer incidences of acute hearing loss. Labyrinthectomy had the greatest vertigo control rate and quality of life scores, but should be reserved for patients with very poor hearing. Based on these findings, the authors recommend that shunt and gentamicin injection are reasonable first line therapies for patients with useful hearing. Vestibular nerve section, under certain circumstances, is also a reasonable surgical option for medically refractory patients. Patients with poor quality of life and frequent attacks might benefit more from nerve section or gentamicin instead of shunt, but the patient needs to weigh the surgical risks of nerve section compared to the increased risk of hearing loss associated with gentamicin.
Patients also need to be aware that gentamicin injection is not as beneficial in patients that have undergone prior procedures, and would not be a good option after a failed nerve section or shunt. Patients with no useful hearing are candidates for both gentamicin injection and labyrinthectomy. The vertigo control rates after labyrinthectomy are far superior to gentamicin injection, but gentamicin benefits from being an in office procedure with little discomfort or operative risk.
These findings confirm that surgery should remain a viable option for treatment medically refractory Meniere’s disease. Endolymphatic mastoid shunt is safe and has reasonable vertigo improvement rates with few risks. Suboccipital vestibular nerve section has very good vertigo control rates that are comparable to gentamicin injection. Labyrinthectomy has outstanding vertigo control rates and patient perception of their improvement is also substantial. Acute hearing loss may be more of a risk from gentamicin therapy, but hearing at two years is similar for surgery and gentamicin therapy.