Search PubMed⌕ Search

Biomedical subjects

T Palva

Publications and source records attributed to T Palva.

At least 37 records · Page 2Linked to original sources
PubMed1996

Prussak's space revisited.

Thirty temporal bones were dissected under the operating microscope, and four whole temporal bone specimens were studied by light microscopy for evaluation of the lateral malleal space and Prussak's space. In all specimens Prussak's space showed a blind end toward the anterior pouch and communicated with the posterior pouch. Its roof consisted of the lateral malleal ligamental fold, which was always strongest in its anterior half and as a rule had a thin area in its posterior portion. In four ears there was a membrane defect connecting Prussak's space to the lateral malleal space. The latter did not contain additional folds and communicated freely with the upper attic. The pathways for spread of an acquired primary cholesteatoma from Prussak's space are outlined.

Culture Techniques↗
PubMed1996

Incudal folds and epitympanic aeration.

Thirty-seven temporal bones were dissected, and the posterior tympanic and epitympanic folds recorded and photographed. Histologic details were documented from four serially sectioned temporal bones, two normal and two inflamed. Of these 41 specimens, 31 were normal, and 10 showed signs of inflammation. The type for the lateral fold was incudomalleal in 16 and incudal in 25 ears. Incus intercrural and incudostapedial folds appeared only exceptionally. Medial and superior incudal folds were not present in normal ears. The anterior tympanic isthmus was a constant, large aeration pathway. In chronically inflamed ears, its partial or total block was caused by polypoid or large sheet-like folds. Inactive sequelae appeared as mature, simple, one-layer or extensive multilayer networks of webs, connected with a deeply indrawn incudomalleal fold. The small posterior isthmus was open to the incudal fossa in 13 ears, and in 28, it was sealed off by a posterior incudal fold. The mastoid air cell tracks were (in ten of 37 dissected ears) open to the incudal fossa, or directly, to the posterior tympanum. Auxiliary pathways due to membrane defects were found in both the horizontal and descending portions of the incudomalleal fold. Excepting the chordal, incudomalleal, and posterior incudal folds, fold-like webs in the posterior tympanum and epitympanum are of inflammatory origin.

Cholesteatoma↗
PubMed1995

Myringoplasty and tympanoplasty--results related to training and experience.

The results of surgery in a series of 452 ears having either myringoplasty (281 ears) or tympanoplasty (171 ears) were studied in relation to the experience of the surgeons. The trainees received an annual course in temporal bone dissection and were given daily surgical instruction in the operating theatre. The 142 ears operated by them showed less disease than those operated upon by the programme chairman (114 ears) and by the faculty (196 ears). The performance of the trainees was safe, and as to healed tympanic membrane and hearing results all studied parameters were statistically equal to those of the faculty. Repair of anterior perforations proved to be the most difficult and the overall results of both the faculty and trainees left place for improvement. On-line recording of surgical data and annual evaluation of an individual surgeon's results is suggested as a necessary means for continuous post-graduate training.

Education↗
PubMed1995

Epitympanic compartment surgical considerations: reevaluation.

The epitympanic compartments and the anatomy of the atticotympanic diaphragm were examined in a pair of serially sectioned temporal bones with secretory otitis media and chronic otitis media, respectively. Findings confirmed reports of 19th century scientists in that Prussak's space has a wide connection to the mesotympanum through the posterior pouch of Tröltsch and may have an additional narrow passage in its roof to the lateral malleal space. The lateral incudomalleal fold regularly separates the upper lateral attic from the lower lateral attic and the mesotympanum. The medial incudal fold as a rule is atrophic already at birth. The anterior tympanic isthmus thus extends from the tensor tympani tendon to the posterior incudal ligament and is the main passage for epitympanic and mastoid aeration. Opening(s) in the tensor fold, when present, are also important. In some ears, the posterior tympanic isthmus may form an auxiliary narrow route for aeration via the incudal fossa. The isthmi may be blocked by middle ear infection, which can lead to chronic mastoid and attic disease. Pathways for cholesteatoma spread in the epitympanum are discussed.

Cholesteatoma, Middle Ear↗
PubMed1994

Recovery of the sutured facial nerve after removal of acoustic neuroma in patients with neurofibromatosis-2.

The authors compared the long-term recovery of sutured facial nerves after the removal of 8 neurofibromatosis-2 (NF2)-associated and 22 non-NF2 acoustic neuromas. The patients were from a series of 270 patients operated on for an acoustic neuroma between 1979 and 1989. The assessment was done with a modified House and Brackmann scale from video recordings. At least some facial movement or tone was achieved (Grade 5 or better) in all but three patients, but in none was the recovery excellent. The facial function, judged by the overall appearance in movement, recovered less in patients with NF2 (P = 0.048); a moderately good recovery (Grade 3 or better) was seen in one patient of eight with NF2, as compared with 13 of 22 with non-NF2. In conclusion, if the tumor cannot be peeled off easily from the facial nerve in patients with NF2, leaving a fragment of tumor behind is preferable to cutting and suturing the facial nerve.

Adolescent↗
PubMed1994

Interface between the facial nerve and large acoustic neurinomas. Immunohistochemical study of the cleavage plane in NF2 and non-NF2 cases.

In acoustic neurinoma surgery, the surgeon is required to find a cleavage plane between the facial nerve and the tumor, and with the aid of the operating microscope this is usually achieved by fine dissection. A histological specimen of the nerve-tumor interface is available only if the facial nerve was hopelessly adherent to the tumor (usually a large or giant neoplasm) and the surgeon decided to sever the nerve to obtain a complete removal. The authors have examined immunohistochemically the nerve-tumor interface of 20 such facial nerves (six cases of neurofibromatosis 2 (NF2) and 14 of non-NF2) in a series of 351 acoustic neurinomas. The largest extrameatal dimension of the 20 tumors ranged from 20 to 51 mm (median 39 mm). In all of these 20 instances the nerve-tumor contact area was at least partially devoid of a clear-cut histological cleavage plane. Where the facial nerve trunk was attached to the surface of the tumor, nerve fibers of the contact areas either abutted directly against tumor cells or nerve fibers were seen to penetrate into the tumor tissue. Frank embedding of nerve fibers was more frequent in NF2.

Adult↗
PubMed1993

Cholesteatoma surgery today.

Four present-day surgical techniques are reviewed to assess their respective merits in surgery for cholesteatoma. The oldest method with an open cavity in ears with mastoid extension of cholesteatoma if combined with partial obliteration is still suitable for less experienced surgeons. Transcanal atticotympanotomy is suitable for limited epitympanic and tympanic cholesteatomas as long as it provides a direct view of the operative field. In similar ears, canal wall up surgery is employed if, additionally, mastoidectomy is needed because of chronic inflammation. Canal wall down surgery with full cavity obliteration with a musculoperiosteal flap, bone chips and bone pate should be the method of choice for all cholesteatomas extending beyond the facial nerve canal. The canal skin is kept as an intact tube and provides quick healing. Open cavities should be revised using similar obliteration techniques but, because of the lack of an intact canal skin tube, making use of a large modified Körner skin flap.

Cholesteatoma, Middle Ear↗
PubMed1993

Surgery for epitympanic cholesteatoma: evaluation of training and experience.

Results of surgery in a series of 175 ears with attic cholesteatoma were studied in relation to the experience of the surgeons. Residents receive an annual course in temporal bone dissection and are given daily surgical instruction in the operating theater. Their performance as to hearing results, healed tympanic membrane, postoperative discharge, and number of recurrences were statistically not different from those of the faculty. The method of intact canal skin surgery is described in detail because training in this type of surgery develops skill in soft tissue conservation. Continuous clinical instruction and frequent evaluation of progress are necessary to guarantee specialist-level results.

Cholesteatoma↗
PubMed1991

Myxoma of the external auditory meatus.

A case of myxoma of the external auditory meatus is described. The patient presented with a recurring tumour which had not been correctly diagnosed although the growth had been removed ten times over a period of two years. The tumour was skin covered, contained gelatinous material and was attached to the tympanic membrane and anterior canal wall. Following recognition of the tumour as myxoma, removal was performed with sufficiently wide margins and there has been no recurrence during follow-up for one year.

Adult↗
PubMed1991

Mast cells and histamine in adenoid tissue and middle ear.

Biopsy specimens from middle ear mucosa of patients with secretory (SOM) and chronic (COM) otitis media as well as specimens of adenoid and tonsil tissue were studied for mast cells. Effusion fluid, nasopharyngeal secretion and supernatant of crushed adenoid tissue were analyzed for histamine with a radioenzymatic method. Astra blue (AB) safranine stained highly significantly more mast cells than did toluidine blue. Mast cell counts in SOM and COM were similar. There were significantly more mast cells in adenoid subepithelial tissue than in middle ear mucosal subepithelial layer. For epithelium the counts were within the same range in adenoids and middle ear mucosa. Histamine concentrations were significantly higher than plasma levels for SOM fluid and nasopharyngeal secretion. Crushed adenoid tissue showed values over 100 times higher than the histamine level in the secretion.

Adenoids↗
PubMed1990

Functional results of facial nerve suture after removal of acoustic neurinoma: analysis of 25 cases.

The facial nerve is sometimes severed during the removal of acoustic neurinomas, either intentionally to ensure complete removal, or unintentionally because of difficulties in identification. In such cases we have, if possible, sutured the nerve stumps microsurgically, either end to end or by use of an intervening nerve graft. We analyzed the outcome of 25 instances of facial nerve suturing in a series of 219 patients operated on for acoustic neurinoma from 1979 to 1987. The first signs of recovery appeared at an average of 12 months, and there was continued improvement for several years. Recovery was graded from 1 to 6. The anastomosis was successful in 24 of the 25 sutured nerves, in that at least some facial movement and tone were restored (Grade 5 or higher). In 11 of the 25 cases, facial appearance at rest and with movement was moderately good (Grade 2 or 3). A Grade 1 result, with no perceivable facial dysfunction, was never achieved. Typically, oral muscles showed the most improvement and frontal muscles the least. Facial appearance was better at rest than with movement, which was always complicated by some degree of synkinesis. Closure of the eye was so good in 13 of the 25 cases that neither tarsorrhaphy nor an eyelid spring was necessary. When the facial nerve is severed, intraoperative suture is recommended, because it provides a chance for moderately good restoration of facial appearance.

Evaluation Studies as Topic↗
PubMed1990

Cochlear implants, vibrators and hearing aids in the rehabilitation of postlingual deafness.

Three groups of postlingually deaf adults were formed by non-random selection. The subjects with some residual hearing were fitted with a powerful hearing aid (HA group, n = 10). The others received either a single-channel vibrotactile aid (V group, n = 8) or a single-channel intracochlear implant (CI group, n = 10). Training containing individual counselling and rehearsal in small groups was arranged. During the follow-up (CI group 2.0 yrs, V group 1.8 yrs, HA group 2.6 yrs), the subject's achievement was assessed by a repetition of audiological testing and written questionnaires. Whereas the HA group obtained the highest scores in the audiological tests, the CI group found the implant most beneficial in everyday life. No significant improvement in the test scores was observed during the follow-up. The extent of personal training, after an initial training period and motivation of the user, did not affect the test scores or the subjective evaluation.

Adult↗
PubMed1989

Plasmin and fibronectin degradation in chronic secretory otitis media.

Mucoid effusions from 39 children with secretory otitis media, altogether 42 specimens, were analyzed for proteolytic activity using radial caseinolysis procedures, for fibronectin using a solid-phase enzyme immunoassay, and for fibronectin fragmentation using immunoblotting. All samples contained proteolytic activity, tentatively identified as plasmin on the basis of comigration with purified human plasmin in zymographic analysis. In 19 specimens the plasmin level exceeded 1 microgram/mg of protein; the highest value recorded was 18.7 micrograms/mg. Low levels of net plasminogen activator activity were found in 12 specimens and identified as urokinase according to comigration with the urokinase standard in zymography. Fibronectin was detected in all but one of the 42 specimens; in seven specimens the levels exceeded those in normal plasma, calculated per milligram of total protein. Extensive fragmentation of fibronectin was found in 19 specimens, correlating with high plasmin levels. The results are indicative of an ongoing proteolytic process in secretory otitis media and suggest that plasmin-caused degradation of the fibronectin-containing basement membrane and subsequent formation of granulation tissue may be involved in the development of adhesive middle ears.

Child↗
PubMed1989

Treatment of labyrinthine fistula.

This cholesteatoma series comprises 84 ears, 81 of which had a labyrinthine fistula and 3 a horizontal semicircular canal opening that arose as a surgical complication. In 49 ears (58.3%), the operation was a primary one; in 35 ears (41.7%), it was a revision. Of all ears, 21 (25%) were deaf preoperatively. The fistula was located in the horizontal canal in 76 ears (90.4%). The matrix was removed in all these ears, and the fistula was covered with fibrin glue and fascia or periosteum. Hearing was preserved in all 57 ears in which matrix removal was carried out as the planned last stage. These included three ears in which the membranous canal was cut deliberately. Surgery that was performed against established rules caused deafness in three ears. Accidental opening of the horizontal canal caused no sensorineural loss in two ears as the fistulas were sealed immediately, while one ear in which the opening was not immediately recognized became deaf.

Cholesteatoma↗
PubMed1989

Surgical control of the mastoid segment in chronic ear disease in 1988.

The basic surgical guidelines for mastoid segment control are described in chronic ear disease. Dense cortical bone paté and mastoid tip bone chips are collected for possible obliteration of the surgical cavity produced. A meatally based musculoperiosteal flap is raised if "canal wall-down" surgery is anticipated. Mastoid bone surgery must be meticulous and the sigmoid, cerebellar and dural plates are first exposed. This is followed by a perilabyrinthine dissection. Tympanic or epitympanic surgery is connected with mastoidectomy as needed. All cavities are then obliterated.

Cholesteatoma↗
PubMed1988

Surgery related to histopathology in chronic inflammatory middle-ear disease.

The world in which Toynbee carried out his clinical and scientific work, from 1838 to his death in 1866, was an entirely different one to our own, lacking all the means of treatment, that we have at our disposal today. Toynbee is remembered above all as a scientist. Systematically he set out to gather histological information in order to penetrate to the depth of the disease processes. He was the first person to conduct extensive temporal bone studies, starting by sectioning and examining a series of 41 bones (Toynbee, 1841) and progressing to a final report in the 1860's when his collection comprised well over 2,000 temporal bones. He described alterations in the inner ear; he demonstrated the otosclerotic fixation of the stapes and, in a large series of bones, he depicted the multitude of histopathological changes seen in the middle ear in chronic otitis media.

Cholesteatoma↗
PubMed1988

The Otorhinolaryngology Department in Helsinki: organization and otologic research.

The organization and the otologic research in the Otorhinolaryngology Department of the University of Helsinki are described. The department has 4 surgical wards, each with 22 beds, and a new surgical wing with 6 full-sized operating rooms. The ear research is centered on middle ear histopathology and immunology, focusing especially on secretory and chronic otitis media. There is an audiological and vestibular unit, the latter is expanding rapidly. Acoustic neuroma surgery is performed as team work with a neurosurgeon. The department takes part in a cochlear implant and Audiant prosthesis program.

Audiology↗