Labyrinthine fistula: an unreported complication of the Grote prosthesis.

OBJECTIVES: To alert the otological surgeon that labyrinthine fistula is a rare and avoidable complication of the Grote hydroxyapatite ceramic external auditory canal (EAC) prosthesis. The reasons for its causation and strategies to prevent its formation are discussed. STUDY DESIGN: Case study and retrospective review of the literature. METHODS: Labyrinthine fistula that occurred after the use of the Grote hydroxyapatite ceramic EAC prosthesis is presented. The literature is reviewed retrospectively for various methods of reconstruction of the EAC following canal wall down mastoidectomy. Strategies and principles are outlined to avoid complications associated with reconstruction of the mastoid and EAC. RESULTS: The Grote hydroxyapatite (HA) prosthesis is a reliable prosthesis for reconstruction of the external auditory canal (EAC) in the absence of a draining mastoid cavity or cholesteatoma and with adequate soft tissue cover. Contact of the medial end of the prosthesis with the lateral semicircular canal must be avoided. Immobilization or rigid fixation and avoidance of infection are essential for optimal prosthesis stability and osseointegration. Covering the prosthesis with vascularized soft tissue appears to be important for the achievement of a successful reconstruction. CONCLUSION: The Grote prosthesis is safe and effective provided it does not contact the lateral semicircular canal, is stabilized, and covered by vesicular tissue, in the absence of infection.

Model studies on a synthetically facile series of N-substituted phenyl-N'-pyridin-3-yl ureas leading to 1-(3-pyridylcarbamoyl) indolines that are potent and selective 5-HT(2C/2B) receptor antagonists.

A model series of 5-HT2C antagonists have been prepared by rapid parallel synthesis. These N-substituted phenyl-N'-pyridin-3-yl ureas were found to have a range of 5-HT2C receptor affinities and selectivities over the closely related 5-HT2A receptor. Extrapolation of simple SAR, derived from this set of compounds, to the more active but synthetically more complex 1-(3-pyridylcarbamoyl)indoline series allowed us to target optimal substitution patterns and identify potent and selective 5-HT(2C/2B) antagonists.

Extra-abdominal fibromatosis (desmoid tumor) arising in the infratemporal fossa: a case report.

Aggressive fibromatosis (or desmoid tumor) refers to a histologically benign but locally aggressive lesion arising from musculoaponeurotic structures in various anatomic sites. Extra-abdominal desmoids represent about one third of all desmoid tumors; of these only about 11 to 15% arise in the head and neck. Desmoid tumors arising in the infratemporal fossa are exceedingly rare; to our knowledge only one such tumor has been reported in the literature. We present a desmoid tumor arising in the infratemporal fossa with intracranial extension in a twenty-seven year old male and review the literature on this rare condition.

Binding of substituted acetic acids to alpha-cyclodextrin in aqueous solution.

Complex binding constants of 23 aliphatic acids with alpha-cyclodextrin in aqueous solution were measured by potentiometry, solubility, or competitive spectrophotometry at 25 degrees C. All systems formed 1:1 acid:cyclodextrin complexes, and some of them also formed 1:2 complexes. The conjugate acids formed stronger complexes than did the conjugate bases (except for glycine). Empirical correlations of complex stabilities are shown with partition coefficients, surface areas, molar refraction, and other descriptors. Complex stability appears to result from the hydrophobic effect, the dispersion interaction, and interaction of the carboxylic acid group with the cyclodextrin.

Binding of cyclodextrins to alicyclic and aromatic substrates: complex formation of alpha-, beta-, and gamma-cyclodextrins with substituted cyclohexanecarboxylic acids and phenylalkanoic acids.

Complex binding constants of the three native cyclodextrins with seven cyclohexane derivatives (all possessing the carboxylic acid group) and with the series C6H5(CH2)nCOOH (n = 0 to 4) were measured in aqueous solution at 25 degrees C by potentiometry and the solubility method. These results, combined with literature data, indicate that alpha- and gamma-cyclodextrins bind with comparable strength to both the cyclohexyl and phenyl moieties, with beta-cyclodextrin binding significantly more strongly. These acid series are compared with several series CH3(CH2)nX, where X is CH3, COOH, COO-, OH, SO3-, etc., and it is concluded that the X group (for X other than methyl) contributes appreciably to complex stability, perhaps by means of an extracavity interaction. The COOH group provides a further augmentation of complex stability. NMR CIS and ROESY results indicate the presence of isomeric complexes in both the cyclohexyl and phenylalkanoic series, and clearly demonstrate the existence of intracavity inclusion. An NOE study of the alpha-cyclodextrin: cyclohexanecarboxylate system provides evidence for inclusion combined with interaction outside (that is, at the rim of) the cavity.

Venous channels of the petrous apex: their presence and clinical importance.

A methyl methacrylate casting technique was used to make detailed casts of the intracerebral venous system of four human cadaver specimens. Seven of the eight petrous apices studied were diploeic (n = 5), or pneumatic (n = 2) and had venules coursing in the anterior petrous apex. These venules form conduits connecting the cavernous to the inferior petrosal sinus or the jugular bulb and have not been previously described. In addition to the air cell system of the petrous apex, these venules may represent pathways for the spread of infection and the development of petrous apicitis, Gradenigo's syndrome, and the rare otogenic cavernous sinus thrombophlebitis. Their presence also may help explain the location of cholesterol granulomas, which afflict this area of the skull base.

Otolaryngological manifestations of factitious disorders--a case and literature review.

Otolaryngological manifestations of factitious disorders are rare. The case of a health care worker who injected her face and orbits with air in order to masquerade as facial cellulitis is presented. The literature and treatment strategies are reviewed.

Neuralgia-like symptoms in a patient with an airgun pellet in the ethmoid sinus: a case report.

An unusual case of a retained airgun pellet in the ethmoid sinus is presented. The patient's only complaint was a severe neuralgic headache. Anatomical basis for this symptom, imaging and successful endoscopic removal of the foreign body are discussed. The philosophy for removal of innocuous foreign bodies, potential pitfalls in surgical management, and a review of the literature are included in the discussion.

In vivo properties of SB 200646A, a 5-HT2C/2B receptor antagonist.

1. SB 200646A, N-(1-methyl-5-indolyl)-N'-(3-pyridyl) urea hydrochloride, the first reported selective 5-HT2C/2B over 5-HT2A receptor antagonist, (pK1 rat 5-HT2C receptor 6.9, pA2 rat 5-HT2B receptor 7.5, pK1 rat 5-HT2A receptor 5.2) dose-dependently blocked a putative rat model of 5-HT2C receptor activation; 1-(3-chlorophenyl)piperazine (mCPP, 5 mg kg-1, i.p. 20 min pretest)-induced hypolocomotion (estimated ID50 19.2 mg kg-1, p.o.). 2. SB 200646A also blocked another putative in vivo model of 5-HT2C receptor function; mCPP (5 mg kg-1, i.p. 20 min pretest)-induced hypophagia in 23 h food-deprived rats (estimated ID50 18.3 mg kg-1, p.o.). 3. SB 200646A did not antagonize 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI)-induced head shakes in rats at doses up to 200 mg kg-1, p.o., an effect thought to be mediated by 5-HT2A receptors for which SB 200646A has its next highest affinity (50 fold less) after the 5-HT2C and 5-HT2B sites. 4. SB 200646A (20, 40 mg kg-1, p.o., 1 h pretest) also reversed mCPP (0.5 mg kg-1, i.p., 30 min pretest)-induced anxiety in the social interaction test, under low light familiar conditions. 5. When given alone, under high light unfamiliar conditions, SB 200646A (2-40 mg kg-1, p.o.) increased active social interaction without affecting locomotor activity in the rat social interaction test. This is consistent with an anxiolytic action of SB 200646A. 6. These results indicate that SB 200646A has in vivo efficacy and that 5-HT2C or 5-HT2B receptors are indeed likely to mediate mCPP-induced hypolocomotion, hypophagia and anxiogenesis. They also suggest that 5-HT2C,2B receptor blockade induces anxiolysis.

A scanning electron microscope study of the human cervical lymph node.

Arterial casts of human cervical lymph nodes were studied using scanning electron microscopy. Human cervical lymph nodes appear to be much more complex and dense than their animal counterparts. Human lymph nodes have a separate medulla arising from the hilar artery complex and cortical structure derived from capillaries. Also present is a previously unknown rosette formation of blood vessels. The possible implications of these findings for inflammatory and neoplastic diseases are discussed.

Cartilage tympanoplasty for management of retraction pockets and cholesteatomas.

Retraction pockets of the tympanic membrane, often associated with dysfunction of the eustachian tube, can be destructive, leading to loss of hearing, ossicular erosion, and development of cholesteatomas. This retrospective study reviews results from 35 patients (38 ears) operated on from January 1988 to June 1991 whose composite cartilage-perichondrial grafts harvested from the tragus were used to reconstruct the tympanic membrane. Early grafts reinforcing the posterosuperior quadrant of the pars tensa showed some failures, with recurrent retraction in the attic. In later grafts, additional placing of cartilage under the pars flaccida prevented failures in the attic. Our indications, initial technique and refinements to the present form, and hearing results are discussed.

Translabyrinthine drillout from suboccipital approach to acoustic neuroma.

The suboccipital approach to acoustic neuroma surgery is used when preservation of hearing is desired or when the surgeon prefers the approach even when hearing cannot be saved. its major disadvantages are poor exposure of the lateral internal auditory canal and lack of precise bony landmarks to identify the facial nerve. When hopes for preservation of hearing are abandoned and complete removal of tumor is considered paramount, a wider drillout of the posterior temporal bone may be accomplished through the suboccipital approach. The posterior semicircular canal may be opened and followed into the vestibule. A translabyrinthine exposure of the vertical crest and full length of the internal auditory canal is readily obtained. Translabyrinthine drillout procedures were performed in 14 patients, and the technique was expedient and yielded excellent exposure. An abdominal fat graft was not required, and only one instance of leakage of cerebrospinal fluid occurred. Translabyrinthine drillout from the suboccipital approach is a useful adjunct when sacrifice of hearing is indicated.

Arterial supply of the human endolymphatic duct and sac.

The arterial anatomy of the endolymphatic duct and sac was studied in vascular casts of methyl methacrylate of six human heads. The chief source of arterial blood supply to the endolymphatic duct and sac appeared to be the occipital artery. Arterioles entered the bone of the mastoid process. Arterioles in bone, the walls of the sigmoid sinus, and the posterior fossa dura coursed medially to supply the endolymphatic sac. The orientation of arterioles tended to be along the long axis of the endolymphatic duct and sac, whereas venules were more likely to be circumferentially oriented. Arterioles arising from dural vessels divided into deeper branches, which supplied periductal connective tissue, and superficial branches, which entered canaliculi of the vestibular aqueduct. Gross anatomic findings were confirmed by histologic examination of temporal bones.

Intravenous fluorescein for detection of perilymphatic fistulas.

It has been reported, in animal models and recently in human beings, that intravenous fluorescein is taken up in perilymph and may be useful as a tracer for the detection of perilymphatic fistulas. We attempted to reproduce the results of these animal experiments. Twenty-one middle ears of eight cats and four dogs were exposed. Fluorescein was given intravenously. Fluorescence was initially noted in transudates pooling in the oval and round window niches. Fistulas created with a straight pick produced a bright fluorescence in the leaking fluids, possibly from a ruptured small membrane vessel. Fistulas created with the carbon dioxide laser and with complete hemostasis demonstrated no fluorescence. We concluded that intravenously administered fluorescein causes dramatic fluorescence of vessels and transudates that may be interpreted falsely as fluorescence of perilymph. Fluorescence was not evident in perilymph when complete hemostasis was obtained.

Hypoplastic endolymphatic sac, hydrops, and Mondini deformity: a case report.

The Mondini deformity of the inner ear is usually associated with a large vestibular aqueduct and endolymphatic sac. The authors present a case with a hypoplastic sac and endolymphatic hydrops, which are presumed to be the cause of the Meniere's syndrome symptoms that occurred in mid-life.

The lateral skull base: a vascular perspective with clinical implications.

The growing number of options in the surgical management of skull base disease has renewed interest in the microvascular anatomy of the lateral temporal region. We studied this anatomy by injecting colored solutions of methyl methacrylate into the major blood vessels of six human cadaver heads or selectively into their major branches. We used several techniques to see the vascular anatomy and to study its relationship to the layers of the scalp. Results revealed that every anatomically named blood vessel was accompanied by a finer, deeper blood vessel supplying the periosteum and outer table of the skull. These vessels arborized into a network of capillaries in the periosteum adherent to the outer bony cortex, from which we saw tiny perforators entering bone. This layered blood supply has direct implications for both ablative and reconstructive surgery for skull base disease. We also saw a previously undescribed arterial plexus accompanying the commonly described venous plexus in the infratemporal fossa.

Chondrogenic potential of tragal perichondrium: a cause of hearing loss following stapedectomy.

Tragal perichondrium is a widely used tissue seal in the oval window following stapes surgery. Autogenous and easily accessible, it is a suitable substance to cover the vestibule in total stapedectomy, and to seal around the prosthesis in small-fenestra stapedotomy. The incidence of complications from the use of perichondrium in this manner is exceedingly low. We report a case where tragal perichondrium in the oval window resulted in the proliferation of cartilage. The cartilage displaced the stapes prosthesis, resulting in a conductive loss. Although the chondrogenic potential of perichondrium is known, we are not aware of other reports implicating this as a cause of failure in stapes surgery. The pertinent clinical and experimental literature regarding chondrogenesis is reviewed. This information suggests that the formation of cartilage from perichondrium in the oval window might be influenced by mechanical trauma and tissue orientation.

Middle fossa decompression of the internal auditory canal in acoustic neuroma surgery: a therapeutic alternative.

Unilateral acoustic neuromas in only-hearing ears and bilateral acoustic neuromas (NF-2) are separate entities, but both pose a common problem because surgical removal has the potential to leave the patient totally deafened. A middle fossa decompression of the internal auditory canal (IAC) was performed in 8 patients (5 with NF-2 tumors and 3 with neuromas in an only-hearing ear). In 5 of the 8, the speech discrimination scores at the 6-month follow-up were better than preoperative scores. After 6 months, however, hearing regressed at variable rates. Although not a definitive therapeutic treatment, decompression of the IAC appears to improve and perhaps prolong useful hearing, which gains valuable time for rehabilitation. Rigid follow-up by computed tomography scans or magnetic resonance imaging is essential.

Ultrastructural characterization of otospongiotic lesions in re-embedded celloidin sections.

A technique of using re-embedded celloidin sections for ultrastructural analysis was used for the study of otospongiosis in human temporal bones. Celloidin sections stored in 80% alcohol with active lesions of cochlear otospongiosis were processed and re-embedded in epoxy resin. Semithin and thin sections were cut and analysed for a characterization of the ultrastructural cellular histopathology. The predominant cell types were found to be osteoblasts/osteocytes and macrophages. Lymphocytes were also noted but were rare. Several osteoblasts showed signs of active collagen and bone matrix production, indicative of ongoing new bone formation and repair. Macrophages often interacted physically to form cell clusters. The macrophages were frequently observed to endocytose the non-mineralized bone matrix as well as to degrade mononuclear cells presumed to represent osteoblasts. The observations may support the notion that increased osteolysis in active ostospongiosis is partly caused by a recruited osteoclast activity and partly by an impaired bone repair mechanism due to a macrophage digestion of osteoblast-deposited non-mineralized bone matrix. These two conditions may act in concert with cellular degradation of bone-producing cells.