Magnetic resonance imaging in a guinea pig model of inner ear decompression sickness and barotrauma.

OBJECTIVES/HYPOTHESIS: Scuba diving may cause severe hearing loss and vertigo due to inner ear barotrauma and decompression sickness. These may be difficult to differentiate clinically. Decompression sickness requires costly and potentially dangerous hyperbaric therapy, whereas such treatment may worsen barotrauma. The objective of this study was to assess the potential utility of magnetic resonance imaging to identify and distinguish blood from air in the inner ear, manifestations of barotrauma and decompression sickness, using a guinea pig model. STUDY DESIGN: Prospective animal trial. METHODS: Magnetic resonance of the head was performed at 3 Tesla, pre- and postinjection of 2, 4, or 10 µL of air or blood through the round window into the perilymph. With this model, 2 µL has been shown to cause hearing loss. Images were reviewed by a neuroradiologist blinded to the treatment. RESULTS: All 14 normal ears, five of seven blood- and five of seven air-injected ears, were correctly interpreted. Two blood- and one air-injected ear were interpreted as indeterminate. One air-injected ear was incorrectly interpreted as blood. CONCLUSIONS: Magnetic resonance reliably distinguishes small volumes of air and blood in the guinea pig inner ear. Magnetic resonance should be evaluated for its utility in the diagnosis of inner ear barotrauma and decompression sickness in scuba divers. LEVEL OF EVIDENCE: NA Laryngoscope, 126:2106-2109, 2016.

Comparison of absorbable with nonabsorbable sutures in closure of facial skin wounds.

BACKGROUND: There is long-standing disagreement among facial plastic surgeons as to the ideal suture material for closing skin wounds of the face. Many surgeons believe that nonabsorbable suture material is preferable, as it is easier to tie, is unlikely to break prematurely, and elicits a minimal inflammatory response. Others feel that these issues are of minor importance and prefer absorbable sutures because they do not have to be removed, thus saving the surgeon time and decreasing patient anxiety and discomfort. PATIENTS AND METHODS: Facial skin cancers were removed from 41 patients. The length of closure ranged from 3.5 to 12.0 cm. All wounds were closed with rotational advancement flaps. Deep tissues were closed with 4-0 poliglecaprone 25 (Monocryl; Ethicon Inc, Somerville, NJ). One half of each wound was randomly closed with 5-0 coated polypropylene (Prolene; Ethicon Inc), while the other half was closed with 5-0 coated irradiated polyglactin 910 (Vicryl Rapide; Ethicon Inc). No wound infections or premature rupture of sutures occurred. All patients were followed up for 6 months after surgery. The photographs of the results were reviewed, and no difference was noted in scar formation. CONCLUSIONS: In adults with clean wounds of the face or neck, there is no difference in long-term cosmetic results of repairs with permanent or absorbable suture material. We prefer absorbable sutures, as they do not have to be removed, saving the surgeon time and lessening patient anxiety and discomfort.

Hyperbaric compression in the guinea pig with perilymph fistula.

OBJECTIVE: The study goal was to evaluate the effects of hyperbaric therapy on the auditory and vestibular function of guinea pigs compromised by perilymph fistula (PLF). METHODS: Twenty-four pigmented guinea pigs underwent induction of bilateral eustachian tube dysfunction before the creation of a unilateral PLF. Half of the animals were randomly assigned to receive immediate hyperbaric compression treatment of 4 "dives" each. Hearing was tested electrocochleographically, and signs of vestibulopathy were recorded before and after compression. RESULTS: After accounting for the effects of PLF, compression was not associated with significant hearing loss (P = 0.5411). Vestibulopathy was seen only in ears with PLF, and its incidence was similar for compression and noncompression groups. CONCLUSION: Hyperbaric compression does not compromise auditory or vestibular function in guinea pig ears with experimental PLF. SIGNIFICANCE: Our observations support the relative safety of recompression in patients with PLF.