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At least 19 recordsLinked to original sources
PubMed1978

Trephination of donor corneal buttons: a scanning electron microscopic study.

Corneal buttons were cut from cat and human donor eyes by anterior trephination (with or without scissor completion) and from excised corneoscleral rims by posterior trephination (with or without a press). Scanning electron microscopy was used to evaluate the slope and quality of the cut edge, the diameter of the section of Descemet's membrane that was actually cut, and the loss of endothelial cells around the cut edge. With anterior trephination, the diameter of the section of Descemet's membrane that is cut was found to be less than that of the trephine because the cut edge slopes inward. Posterior trephination with or without a press consistently produced circular buttons with accurately cut outward-sloping edges. This resulted in a diameter of Descemet's membrane which was greater than in the anteriorly trephinated buttons. There also was less damage to peripheral Descemet's membrane and endothelium with the posterior method, especially when compared to scissor cut buttons. A 360 degree peripheral ring of Descemet's membrnae (0.05 to 0.28 mm in width) was denuded of endothelial cells with all techniques.

Animals↗
PubMed1978

[Comparative studies with scanning electron microscope on the quality of corneal disk incision using various corneal trephine (author's transl)].

The cut surface of corneal stroma from rabbits was studied with a scanning-electron microscope and compared after using a manual trephine, a motor-driven rotor trephine and a rotor trephine with mechanical guidance. It became evident that the cut surface obtained with the motor-driven trephine is clearly smoother than that obtained with manual trephine. A further improvement in the quality of the cut is evident with a mechanically guided trephine.

Animals↗
PubMed1979

Variation in corneal graft size related to trephine technique.

To determine the range of variation in corneal transplant tissue size induced by slight changes in trephination technique, four human corneas that had been stored in McCarey-Kaufman medium and 11 intact human globes were used. Endothelial surface trephination yielded a smaller corneal button than epithelial trephination. In the intact eye, the higher the intraocular pressure was, the larger the resulting corneal diameter. With use of a trephine with a central plunger, the higher the obturator was, the larger the diameter of the resulting tissue. Also, the duller the trephine was, the larger the diameter of the cut, due to difficulty in tissue penetration. Thus, slight variations can markedly affect the match in size between donor and recipient.

Corneal Transplantation↗
PubMed2026

Volumetric bone marrow cellularity (VBMC) assessment from routinely processed trephines using three-dimensional x-ray histology and gaussian peak modelling.

Objective.Bone marrow cellularity is routinely estimated from a small number of two-dimensional histology sections, making assessment sensitive to section representativeness, processing artefacts and observer interpretation. Three-dimensional (3D) x-ray histology (XRH), using x-ray computed microtomography (µCT), enables non-destructive whole-block imaging of trephine biopsies. This study evaluated whether XRH combined with Gaussian peak modelling could provide a pragmatic whole-block volumetric bone marrow cellularity (VBMC) estimate from formalin-fixed paraffin-embedded (FFPE) trephine biopsy blocks.Approach.Six routinely processed FFPE bone marrow trephine blocks were imaged using µCT-based XRH at ∼15 µm spatial resolution. VBMC was defined as the red-marrow (RM) fraction of the marrow soft-tissue compartment, RM/(RM + intra-biopsy wax), with wax serving as the volumetric proxy for adipocyte/yellow marrow space. Whole-volume greyscale histograms were modelled using a three-peak Gaussian approach representing intra-biopsy wax, RM and demineralised trabecular matrix. Peak-height and area-under-the-curve metrics were compared with whole-volume 3D segmentation and clinical two-dimensional (2D) cellularity estimates.Main Results.Gaussian peak modelling successfully approximated the segmented tissue-phase distributions. The peak-height-derived VBMC metric showed the closest agreement with whole-volume 3D segmentation, with an average absolute percentage difference of 9.3%, compared with 18.6% for clinical expert 2D cellularity estimates. The area-under-the-curve metric followed similar trends but consistently overestimated VBMC. Clinical 2D cellularity broadly followed whole-biopsy trends but showed one discordant case not explained by slice-position sampling alone. XRH also enabled unrestricted virtual reslicing and visualisation of sectioning-associated artefacts prior to further microtomy.Significance.Pre-sectioning XRH combined with Gaussian peak modelling provides a rapid, segmentation-free route to volumetric cellularity estimation from intact clinical FFPE trephine blocks. The approach supports objective whole-biopsy assessment while remaining compatible with routine histopathology workflows, reflecting the expected limitations of section-based visual estimation despite its role as the current clinical standard. In the near term, it could provide a non-disruptive adjunct to conventional 2D cellularity reporting, pending larger validation studies.

Imaging, Three-Dimensional↗
PubMed1979

Bilateral trephine bone marrow biopsies in Hodgkin's and non-Hodgkin's lymphoma.

This study was undertaken to investigate the usefulness of bilateral rather than unilateral iliac trephine biopsies in demonstrating Hodgkin's disease and non-Hodgkin's lymphoma in the bone marrow. One hundred and seventy adequate bilateral biopsies were obtained from 145 patients. Among 76 bilateral trephine biopsies from 65 patients with Hodgkin's disease, tumour was found bilaterally in 3 cases and on only one side in 2 cases. Among 94 bilateral biopsies from 80 patients with non-Hodgkin's lymphoma, tumour was found bilaterally in 17 cases and on only one side in 12. Considering all of the cases in the series, the performance of bilateral biopsy increased the yield of positive marrows from an estimate of 27 to 34, an increase of 26%. We conclude that bilateral trephine biopsy is superior to unilateral biopsy for the demonstration of bone marrow involvement by Hodgkin's disease or non-Hodgkin's lymphoma and recommend that bilateral trephine biopsies be performed when a knowledge of the state of the bone marrow is important for clinical decision making.

Biopsy↗
PubMed1979

A bone-fixing trephine for large-diameter iliac biopsies in dogs.

For experimental studies of bone in dogs it may be necessary to collect from the iliac crest biopsies of a larger diameter than is usually obtainable. A disadvantage of using a trephine with a large bore is that the biopsy may be pulled out of the trephine by the forces exerted by tendons inserted in the medial cortex of the ilium. To overcome this difficulty we developed a trephine with an internal bore of 10 mm combined with a biopsy-fixing attachment.

Animals↗
PubMed1979

Trephine biopsy of the bone marrow in disseminated histoplasmosis.

Twenty-two patients had bone marrow aspirates for culture and marrow trephine biopsies for histologic examination during the evaluation of an illness eventually proved to be disseminated histoplasmosis. These procedures provided evidence of involvement of the bone marrow with Histoplasma capsulatum in 19 cases. Fungi were demonstrated in trephine biopsy sections in 15 of the patients, permitting a rapid specific diagnosis. Three patterns of bone marrow morphology were observed; each reflected a variation of macrophage proliferation. In two of the patterns, diffuse macrophage proliferation and loose aggregates of macrophages, typical 2 to 4 microns intracellular hisoplasma organisms were numerous and obvious in hematoxylin and eosin-stained sections, were infrequent and were often relatively large (6 to 12 microns). There were four patients from whom H. capsulatum was cultured when organisms could not be demonstrated in either hematoxylin and eosin- or silver-stained sections. The patients with diffuse proliferation of macrophages in the marrow comprised a distinct clinical group associated with immunosuppression, a fulminant course and a fatal outcome despite therapy. Patients in the other two morphologic groups responded well to therapy even though the immune responses on many were also suppressed. Bone marrow examination is an excellent diagnostic procedure in disseminated histoplasmosis. Trephine biopsies permit a rapid diagnosis in most cases and may be of prognostic significance.

Adolescent↗
PubMed1977

[Combined trephining with scleral flap (Elliot-Fronimopoulos) and intracapsular cataract extraction (author's transl)].

68 eyes of 51 non-selected patients on which a combined cataract extraction and Elliot's trephining with scleral flap (Fronimopoulos) had been performed between 1972 and september 1976, were re-examined between 6 and 48 months following operation. Postoperative complications were rare: there was one persistent shallow anterior chamber following excessive filtration, one increase of tension floowing a block of the trephine canal by vitreous, and one increase of tension following too tight suturing of the scleral flap which necessitated re-operation. Tension was compensated without therapy in 42 eyes (61,7%) and with local therapy in 24 eyes (35,3%). Only in 2 eyes (3%) normal intra-ocular pressure was not achieved. Altogether 97% of the eyes were compensated, some with additional local therapy. The combined cataract extraction and Elliot's trephining with scleral flap (Fronimopoulos) is an effective and low risk technique that is recommended in cases of cataract with raised intraocular pressure not controlled by medical treatment.

Adult↗
PubMed1977

Comparing radioactive and trephine-disk bioassays of dicloxacillin and gentamicin in ocular tissues in vitro.

Trephined disks of tissue (6 mm diameter) from fresh rabbit eyes were immersed overnight in solutions of radioactive carbon (14C)-dicloxacillin or gentamicin, then assayed by one of two methods: agar-diffusion bioassay, using filter-paper disks immersed in known concentrations of antibiotic as standards, or radioactive assay. The bioassay underestimated the concentrations of antibiotic in sclera and iris by 38 to 72%, and slightly overestimated those in the cornea. A corrected bioassay was calculated, based on the differences in fluid mass between tissue specimens and filter-paper disks; this value was within 20% of the radioactive assay in 18 of 24 experiments with dicloxacillin, and in 14 of 24 with gentamicin. There was evidence of pronounced binding of gentamicin to ocular tissues (iris greater than sclera greater than cornea); this appeared to be a saturable and reversible phenomenon. Less marked binding of dicloxacillin to iris and sclera was noted. The results indicated that, depending on the degree of accuracy required, the corrected trephine-disk agar-diffusion bioassay provides a reasonable estimate of the antibiotic content of ocular tissues.

Animals↗
PubMed1976

Comparison of the efficacies of closed trephine needle biopsy, aspirated paraffin-embedded clot section, and smear preparation in the diagnosis of bone-marrow involvement by lymphoma.

Bone marrow aspirates totaling 1,024 and trephine biopsies totaling 386 were obtained from 234 patients with various diagnoses of lymphoma. The study analyzed the morphologic patterns of bone-marrow involvement by each entity and compared the sensitivity of aspiration versus biopsy for detecting lymphomatous involvement of bone marrow. Lymphoma may appear in one of three forms: nodular, diffuse (packed bone marrow), and diffusely infiltrative. Trephine biopsy was superior to aspiration in most instances, especially for the nodular form. In some cases, however, examination of paraffin-embedded clot sections and smears was diagnostic of lymphoma whereas the biopsy section appeared negative.

Biopsy, Needle↗
PubMed1978

Bone marrow aspiration and trephine biopsy. An approach to a thorough study.

Recent advances in the treatment of hematologic malignancies have been paralleled by renewed interest on the part of pathologists and hematologists in methods of obtaining and preparing bone marrow for diagnostic studies. A thorough bone marrow morphologic study involves examination of peripheral blood smears, direct, particle, and buffy coat bone marrow smears, trephine biopsy imprints, particle and trephine biopsy sections, and marrow volumetric data. The information obtained from the study of these various specimens is complementary. Frequently it is a combination of clues gathered from examination of several different preparations that leads to a correct diagnosis. Utilization of biopsy material by the methods described provides complete, accurate and reproducible information and minimizes the necessity for repeating a biopsy for morphologic diagnosis or ancillary studies.

Anemia, Aplastic↗
PubMed1977

[Express method of histological processing of trephined bone marrow].

A method for histological treatment of the trephined bone marrow is suggested; it makes it possible to simplify the manipulation and to shorten the time of treatment of biopsy material by more than 24 hours, thereby enabling the investigator to give the conclusion about the state of the medullar hemopoiesis on the same day. The principle of the method consists in combining the stages of fixation and decalcification and also in acceleration of the final stage of treatment of the trephined bone marrow due to electrodecalcification of the osseous tissue.

Biopsy↗
PubMed1979

Skin tumors and trephines.

Outmoded glaucoma and corneal trephines may be used to obtain incisional and excisional biopsies from eyelid lesions. The wounds created in doing the incisional biopsy are ignored and those created by doing excisions are closed by grafts using the same trephine.

Biopsy↗
PubMed1979

A new microsurgical corneal trephine.

A new corneal trephine has been described which allows the surgeon to see the circumference of the cutting edge, as well as most of the cornea, lens and iris, while looking through the operating microscope. The trephine has a 3-mm cutting ring supported by an open "branding iron" structure.

Cataract Extraction↗
PubMed1976

A new corneal trephine.

A new corneal trephine, using suction and disposable razor blades, comprised two cones, one revolving inside the other. A slide mechanism was attached to the inner cone that inclined a disposable razor blade either vertically or at 20 degrees, assuring clear view of either side of the incision and more accurate centering. The effective diameter of the cut was varied continuously from 8.5 to 2.0 mm.

Corneal Transplantation↗
PubMed1978

Chalazion management by tarsus trephination.

The use of a small trephine for chalazion surgery or tarsal biopsy is described. Over 1,000 cases have been treated in this manner with minimal recurrences and complications.

Cysts↗