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PubMed2001

Closed-system and open-sky capsulorhexis for combined cataract extraction and corneal transplantation.

We describe a triple procedure combining corneal transplantation, cataract extraction, and intraocular lens implantation in which the continuous curvilinear capsulorhexis (CCC) is performed in a closed system when corneal transparency is sufficient or using an open-sky method when corneal transparency is poor. With the closed system, the CCC is performed first followed by trephination and hydroexpulsion of the nucleus. A Caporossi coaxial forceps is used to reduce the corneal incision to 1.2 mm, preventing the need for sutures. Tunnel formation, which could limit the size of trephination, is avoided. In addition, endothelial cell loss at the periphery of the recipient cornea is reduced. This technique was performed in 10 eyes without intraoperative complications. With the open-sky method, the CCC is created while counterpressure is applied to the center of the lens with a large spatula, reducing posterior pressure and thus the risk of capsule tear. This technique was performed in 9 eyes without intraoperative complications.

Capsulorhexis↗
PubMed2002

Healon5 tamponade of corneal perforation during transplantation surgery.

In "a chaud" keratoplasty in cases of corneal perforation, the main difficulty is the trephination of the recipient cornea in a soft eye. A temporary tamponade of the perforation can be provided by filling the anterior chamber with sodium hyaluronate 2.3% (Healon5). The cornea can then be grasped with vacuum and trephinated.

Aged↗
PubMed1993

Temporary keratoprosthesis for transscleral fixation of posterior chamber intraocular lenses with penetrating keratoplasty.

In the absence of zonular and capsular support, cataract surgeons increasingly prefer suture-fixated posterior chamber intraocular lenses (IOLs) to angle-supported anterior chamber lenses as a secondary IOL. Various suturing techniques have been proposed for fixating the posterior chamber IOL. Transscleral suture fixation appears advantageous but problematic when performed on an open globe. Moreover, excision of the vitreous base is impeded by the iris and the dark, unstable image. This article describes a technique that takes advantage of a temporary keratoprosthesis (TKP). When sutured onto the trephination opening, the TKP provides a bright, stable image and permits peripheral indentation of the globe, allowing for controlled, thorough vitrectomy. With the infusion pressure supplying adequate eye tone, ab externo transfixation, and thus a targeted passage of the sulcus, is possible. If the cornea permits transfixation, TKP may be used to tamponade after trephination and as a lens rest while the surgeon ties the sutures to the haptics.

Aged↗
PubMed1989

Epikeratophakia: technique modifications and visual results compared to the national study.

Twenty-eight epikeratophakia procedures have been performed at the University of Minnesota since December 1985. This report describes several technique modifications and compares the refractive and visual outcome of these cases with the national results. There have been 17 aphakic cases (13 adult and four pediatric), seven myopic procedures, and four keratoconus cases. Of the adult aphakic cases, 80% were within 3 diopters of emmetropia at six months, with four cases showing an undercorrection. In the myopic group, five cases showed an overcorrection at six months and all patients were within two Snellen lines or better than their preoperative best corrected vision. The major complications included one graft removal for failure to epithelialize, an interface hematoma, and a severe overcorrection to +9.37 diopters in a myopic patient. A no-keratectomy technique was used in the aphakic and myopic groups. A variation on centering the Hessburg-Barron trephine and removing the epithelium was performed and allowed for more accurate trephine placement.

Adult↗
PubMed1997

Low dosage of native allogeneic bone morphogenetic protein in repair of sheep calvarial defects.

A sheep skull trephine defect model was used to test the efficacy of allogeneic partially purified sheep bone morphogenetic protein (sBMP), extracted using a low-cost alternative technique based on 60% ammonium sulphate saturation of the guanethidine-HCI extract of pulverized bone matrix. Eight mg of partially purified sBMP was implanted in six 22-mm right-side sheep calvarial critical-size defects trephined in the diploë area using a midline incision; left-side defects implanted with an equal amount of type IV collagen served as controls. After 16 weeks the sheep were killed and the defects removed. Formation of new bone was evaluated using radiomorphometry and histomorphometry. The healing percentage in sBMP-implanted defects was 60.8 +/- 8.1% and in controls 49.8 +/- 6.7% (P < 0.05) as assessed by radiomorphometry. In cross-sectional histomorphometry, newly formed bone regenerated 50.9 +/- 15.1% in the defects with sBMP and 16.1 +/- 10.6% in controls (P < 0.01). The good result, considering the low dosage of sBMP, can be explained by the strong osteoinductivity and low immunogenicity of native allogeneic sBMP.

Ammonium Sulfate↗
PubMed1995

Bone marrow infiltration by a parietal lobe grade III oligodendroglioma.

We report a patient with oligodendroglioma metastases 1 year after tumour debulking and postoperative radiotherapy to the parietal lobe primary. This treatment controlled the patient's tumour locally. Distant recurrence was manifest by back pain, weight loss and malaise. The serum alkaline phosphatase was raised and a bone scan showed generalized increased uptake. Bone marrow trephine revealed infiltration by oligodendroglioma. Bone marrow infiltration by gliomas is very rare. If the trephine had not been performed it might have been assumed that he had a disseminated second primary tumour.

Bone Marrow Neoplasms↗
PubMed2004

Observations on healing of human tooth extraction sockets implanted with bioabsorbable polylactic-polyglycolic acids (PLGA) copolymer root replicas: a clinical, radiographic, and histologic follow-up report of 8 cases.

OBJECTIVE: The objective was to conduct a clinical, radiographic, and histologic follow-up of alveolar socket healing in 8 human cases in which the extraction sockets of the involved teeth were treated with biodegradable root replicas before metallic implants were placed. STUDY DESIGN: Chair side prepared solid and porous forms of root replicas made out of polylactic-polyglycolic acids (PLGA) copolymer were utilized. Five patients were treated with the solid form and 3 with the porous form of the replicas. The cases were followed up at regular intervals postoperatively, and standardized photographs and radiographs were taken. The cylindrical core of biopsies that were removed with trephine for placement of titanium implants were processed and examined by light and transmission-electron microscopy. RESULTS: Both forms of the root replicas were well tolerated and biodegraded by the body. There were no histologically observable pathological tissue reactions at the time of implant application. However, the solid form seemed to cause an initial decalcification of the bone surrounding the extraction sockets that was subsequently repaired along with the bone healing of the extraction sockets. Such initial decalcification of the alveolar process was not observed in the cases that were treated with the porous form of root replicas. There was wide variation in the osseous component of the trephine-harvested biopsies in both treatment groups that suggests inconsistency in bone healing of the alveolar sockets. CONCLUSION: The 2 forms of root replicas under investigation were found to be biocompatible and biodegradable. But the compact solid form may cause an initial temporary lactic acid induced decalcification of the alveolar process, which makes it unsuitable for regular clinical application as compared to the granular porous form. The observed inconsistent and unpredictable bone regeneration calls for further research to develop more optimal replica materials.

Absorbable Implants↗
PubMed2004

Irradiation after surgically induced brain injury in the rat: timing in relation to severity of radiation damage.

The aim of this study was to evaluate how timing of irradiation after brain surgery in rats relates to overall extent of brain radiation damage. Extent of injury was determined according to lipid peroxidation (malondialdehyde; MDA) levels in brain tissue. Thirty female rats were randomly assigned to five equal groups (Groups A-E). Four groups underwent trephination and scalpel hemisection of right frontal lobe. Rats in Groups B and D received 25 Gy cranial irradiation in a LINAC system at 10 and 20 days after surgery, respectively. Twenty-four hours later they were killed and their right frontal lobes were removed for lipid peroxidation determination. Groups A and C were not irradiated; these groups were killed and had their frontal lobes removed on day 11 and day 21 post-surgery, respectively. The remaining six animals (Group E, sham surgery) underwent trephination only, and were killed and had their frontal lobes removed 24 h later. There was a significant difference between the mean MDA levels in the control group and Group D, and between the levels in Group B and Group D (P < 0.05 for both). The difference between the mean for Group A and the mean for Group B was even more significant (P < 0.01). The most striking differences were between the control group and Group B, and between Group B and Group C (P < 0.001 for both). The data from this rat model suggest that, in humans, starting radiotherapy early (1-2 weeks) after debulking of a brain tumor may result in significantly higher levels of tissue damage than if the radiation is started 3 weeks or more postoperatively. Further experimental research is needed to project these findings in rats to human subjects.

Animals↗
PubMed2000

Predetermined implant positioning by means of a novel guide template technique.

This paper presents a novel guide template technique for implant placement. In esthetic implant dentistry with its restoration-driven implant placement as well as in complete-arch cases with multiple implants, the precise positioning and angulation of dental implants is crucial for achieving the desired prosthetic results. Difficulties in implant positioning may arise especially with grafted jaws resulting from communication problems between surgeon and prosthodontist. This method may alleviate some of the problems common to conventional template techniques, where the drill is usually directly guided by the template. The key idea is to fixate the implant position and angulation by the help of Kirschner wires which are inserted in the alveolar ridge right through the mucosa before elevation of a mucoperiosteal flap. Thanks to this sequence, the template for guiding the wires may be positioned precisely, even on grafted edentulous ridges. After the insertion of the wires, the bone is exposed and the implant cavities prepared with a trephine drill guided over the wires alone or over wires combined with a special guidance cylinder fitting the trephine drill. The method may be combined with different planning and radiological techniques. Since the use of the template is detached from the actual drilling process, the danger of introducing debris of plastic or metal into the preparation site may be avoided. The present technique might be helpful for difficult cases by improving communication between prosthodontist and surgeon and also render additional security to the surgeon with less routine in dental implant insertion.

Dental Implantation, Endosseous↗
PubMed2002

Localisation and distribution of hyaluronan in normal bone marrow matrix: a novel method to evaluate impending fibrosis?

Bone marrow trephine biopsies from 30 healthy volunteers, 10 men and 20 women aged 18-60 yr were obtained for identification and localisation of hyaluronan (HYA). Fixation, decalcification and embedding were performed by two different methods, with identical results in both. For comparison bone marrow trephine biopsies from three patients with different haematological diseases and known fibrosis were studied. All bone marrow specimens were also stained for reticulin grading. HYA was found in the bone marrow specimens from healthy individuals in a pattern that was concordant with the reticulin staining, the common way of visualising bone marrow fibrosis. In bone marrow from the patients with known fibrosis the HYA and reticulin staining were both more intense and abundant. Interestingly, HYA was also found intracellularly in eosinophilic cells in normal bone marrow. HYA is a polysaccharide unique both in structural and biological properties, and in excess it may predict bone marrow fibrosis.

Adolescent↗
PubMed2003

Enzyme replacement therapy reduces Gaucher cell burden but may accelerate osteopenia in patients with type I disease - a histological study.

Enzyme replacement treatment (ERT) is effective in controlling the clinical and biochemical manifestation of type I Gaucher disease. Little is known on the evolution of bone marrow histology caused by ERT. We compared the pretreatment trephine bone marrow biopsies in five patients (F32, F41, F50, M55, and M46) with the control biopsies performed after 26-32 months of imiglucerase treatment. The planimetric estimates revealed significant decrease in Gaucher cell burden in all the patients. The post-ERT values ranged from 24% to 65% of the initial total volumes occupied by the Gaucher cells. This resulted mainly from disappearance of Gaucher cells, and to a lesser extent from their shrinkage. Normal hemopoiesis was markedly increased in four of five patients, fat tissue in all the five patients. Surprisingly, the estimated volumes of trabecular bone in the control biopsies were significantly smaller than in the pre-ERT trephines (0.61%, 0.64%, 0.64%, 0.97%, and 0.22% of the initial volumes, P = 0.043). The bone loss correlated rather with the degree of reconstitution of normal hemopoiesis than with the decrease in the Gaucher cell burden. The histological response did not correlate strictly with initial clinical parameters and the genotype, with different reactions to ERT in two sibs (cases 3 and 4). Particularly, ERT alleviated bone manifestations in all four patients with previous bone pains or fractures. ERT may accelerate progress of osteopenia in men and premenopausal women. The clinical significance of this phenomenon remains to be established. Its mechanism may be linked to increased osteolytic activity exerted directly or indirectly by regenerating hemopoietic cells.

Adult↗
PubMed2000

Erythropoietic reconstitution, macrophages and reticulin fibrosis in bone marrow specimens of CML patients following allogeneic transplantation.

A clinicopathological study was conducted on 351 bone marrow trephine biopsies derived from 124 patients with chronic myeloid leukemia (CML) at standardized endpoints before and after allogeneic bone marrow transplantation (BMT). The purpose was to investigate quantitative changes of the nucleated erythroid precursor cell population and other associated features such as resident bone marrow macrophages and myelofibrosis and to elucidate their relevance on engraftment parameters. Monoclonal antibodies were applied for the identification of erythroid precursors and the labeling of mature macrophages; argyrophilic (reticulin-collagen) fibers were demonstrated by a silver impregnation technique. Following morphometric analysis of the pregraft bone marrow specimens statistical evaluation was in line with an adverse correlation between early to moderate reticulin fibrosis and amount of erythropoiesis. Moreover, a significant relationship was calculable between numbers of erythroid precursors and CD68+ macrophages. After myelo-ablative therapy and BMT a pronounced decrease in cellularity and in the quantity of erythropoiesis was found. Comparable with the pregraft samples, a significant association between erythroid precursors and macrophages could be determined in the regenerating donor bone marrow. A pretransplant relevant reduction of the red cell lineage and a manifest (reticulin) myelofibrosis indicating an advanced stage of disease were accompanied by a significant delay to reach transfusion independence. This result was further supported by comparable findings in trephine biopsies performed in the early post-transplant period (second month after BMT). Corresponding examinations revealed an enhancement of fiber density and a decrease in erythropoiesis in those patients who did not conform with the usually accepted criteria for successful engraftment. In conclusion, compelling evidence has been produced that a significantly reduced amount of erythroid precursors, which is usually associated with myelofibrosis in the pretransplant bone marrow, exerts an impairment to undisturbed hematopoietic reconstitution. Moreover, a close spatial and numerical relationship between the erythroid lineage and resident (mature) macrophages is observable, in particular in the state of regeneration after BMT.

Adolescent↗
PubMed2003

Efficacy of bovine bone mineral for alveolar augmentation: a human histologic study.

The purpose of this study was to evaluate the osteoconductivity of bovine bone mineral in humans. Fifteen patients referred to a private specialist surgical practice were treated consecutively for the repair of alveolar defects, and/or ridge maintenance at the site of extraction sockets, prior to implantation. Bio-Oss xenograft (Geistlich Pharma, Wolhusen, Switzerland) was utilized as the principal grafting material. Bone cores were trephined out at the time of implant placement and processed and examined to evaluate the tissue response under the light microscope. A total of 22 trephines were processed for histomorphometric evaluation to calculate the mean percentage of bone, residual graft and connective tissue by area. In addition, the mean percentage bone-to-graft contact was also calculated. The mean percentage area of new bone formation was 26.9%, and the percentage of residual graft and connective tissue as 25.6% and 47.4% respectively. The mean percentage contact length between bone and residual graft was 34%. One implant placed into a site, which was histologically identified as having little new bone and, unusually, an inflammatory infiltrate, failed with mobility at abutment connection. All other implants were restored into function, with a survival rate at baseline of 97%.

Adult↗
PubMed2002

Increased angiogenesis in bone marrow of children with acute lymphoblastic leukaemia has no prognostic significance.

The importance of angiogenesis for the growth and viability of solid tumours has been established. Similarly, prognostic information may be gained from the extent of angiogenesis in these tumours. Haematopoietic malignancies should have equal requirements for angiogenesis and important prognostic information may be derived from quantification of bone marrow angiogenic activity. We retrospectively investigated 82 bone marrow trephine biopsies from 41 children with acute lymphoblastic leukaemia (ALL) at diagnosis and following treatment. Nine normal bone marrow trephines from age-matched children were also analysed as controls. The microvessels were stained immunohistochemically with anti-Factor VIII-related antigen (antivWF) and antithrombomodulin (anti-THR). Angiogenesis was quantified manually by two independent observers and was highly reproducible (Pearson's r = 0.91). Staining with anti-vWF and anti-THR was highly specific for microvessels and thetwo stains closely correlated (r = 0.68). Microvessel densities (MVD) at presentation were significantly increased in the majority of patients in comparison with controls (P < 0.0001) and MVD dropped towards normal in remission (P < 0.0001). Of interest, the difference in total vessel counts between leukaemic and normal/remission marrows was contributed solely by small microvessels. There was no significant difference in MVD at presentation or remission from children in poor prognostic groups or those who subsequently relapsed. Similarly, we could not find an association with age, sex, cytogenetic abnormality or disease phenotype.

Adolescent↗
PubMed2001

Intracranial bleeding rates associated with two methods of external ventricular drainage.

We investigated the risk of intracranial haemorrhage with two frequently performed methods of external ventricular drainage (EVD). Haemorrhage is believed to be a rare complication of such procedures, although in most studies reported in the literature standardised evaluation of computed tomography (CT) scans was not performed in all cases. Data were analysed retrospectively for 82 patients who had undergone percutaneous needle trephination and 92 who had undergone classic ventriculostomy. We found an overall bleeding risk with EVD of 9.4%. Most haematomas were small, and only one caused neurological symptoms. Therefore, the risk of symptomatic haemorrhage in this study was low (0.5%). Percutaneous needle trephination was associated with a higher risk of haemorrhage (12.2%) than classic ventriculostomy (6.5%), although differences were not statistically significant. We conclude from our results that small asymptomatic haemorrhages occur far more often after EVD than has generally been suspected. To compare the true risk of bleeding associated with different drainage methods requires controlled studies in which CT scans are evaluated in a standardised way.

Adolescent↗
PubMed2004

[The use of intracorneal rings in penetrating keratoplasty].

BACKGROUND: The visual rehabilitation after penetrating keratoplasty (PKP) is affected by postoperative corneal astigmatism. Up to now studies were focused on different trephine systems as well as the suture techniques. A new option for reducing postoperative corneal astigmatism could be the implantation of an intracorneal ring. PATIENTS AND METHODS: Over a period of 2 years we implanted in 20 patients, who were suffering from keratoconus, Fuchs' dystrophy or bullous keratopathy, an 8-mm cobalt-molybdenum-titanium intracorneal ring in a prospective clinical trial. We used the guided trephine system (GTS) for preparation and a 10-0 nylon double running suture. The mean follow-up period was 16.2 months. A control group of 20 additional patients who underwent PKP was randomized. Topographic astigmatism as well as the spherical equivalent was evaluated after 1, 3, 6 and 12 months, respectively. RESULTS: Although a lower topographic astigmatism in the intracorneal ring group was reached 12 months postoperatively (3.0 dptr., SD 1.2 versus 4.0 dptr., SD 1.8) no statistical significance was found. The spherical equivalent in that group was lower during the complete evaluation period with a hyperopization in both groups as well. We did not see any immunological reactions caused by the ring. CONCLUSIONS: Whether the intracorneal ring could be a useful addition to PKP is not yet clear. Therefore more patients need to be enrolled and further studies established.

Alloys↗
PubMed1998

[Interpretation of corneal topography after penetrating keratoplasty with wave-front parameters--comparison between non-mechanical trepanation with excimer laser and motor trepanation].

BACKGROUND: Besides irregular astigmatism characterized by the asymmetric components of the corneal surface, the aberration of the cornea from an ideal sphere degrades the optical performance of the "optical system eye". Best-corrected visual acuity may be markedly decreased with an increasing aperture diameter. The purpose of this study was to evaluate the time course of the symmetrical part of the aberration from an ideal sphere and to correlate it with functional results after penetrating keratoplasty (PK). PATIENTS AND METHODS: Fifty patients each (20 primary dystrophies, 30 keratoconus) underwent nonmechanical trephination (NMT) (excimer laser MEL60, Aesculap-Meditec, Heroldsberg, Germany) or mechanical motor trephination (MT) in penetrating keratoplasty. All procedures (7.5 mm in dystrophies, 8.0 mm in keratoconus, 8 orientation teeth in NMT, double-running 10-0 nylon suture) were performed by one surgeon (GOHN). At a postoperative gate of 6 weeks, 6 months, before partial suture removal and after complete suture removal, corneal topography analysis (TMS-1, Tomey, Tennenlohe, Germany) was performed. After a Gram-Schmidt-orthogonalization, corneal topography height data of 25 noncentric rings in 256 hemimeridians were decomposed into Zernike components of radial order n = 16 in the sense of minimizing the root mean square error. The symmetrical part of the deviation from an ideal spherical surface was calculated from the Zernike components Z4(0), Z6(0), ..., Z16(0). From the Zernike components, the longitudinal focus distribution and its standard deviation (SDF) was determined. SDF was correlated with the surface asymmetry index (SAI), the surface regularity index (SRI), the potential visual acuity (PVA) of the TMS-1 and the spectacle-corrected visual acuity. RESULTS: In the time course after PK, SDF decreased from the 6 weeks follow-up examination to the end of the follow-up from 1.27 mm to 0.77 mm in NMT (p = 0.01) and from 1.29 mm to 1.20 mm following MT (p = 0.24) within the central corneal region of 3 mm in diameter. The SAI did not depend on SDF, whereas the SRI correlated significantly inversely with the SDF within the 3 mm zone immediately before (p = 0.01 and p = 0.02) and after suture removal (p = 0.01 each) after NMT. After MT, only a mild inverse correlation was observed before (p = 0.05) and after suture removal (p = 0.04). In the time course after the 6 months follow-up the SDF within the 3 mm central area correlated inversely with the best-corrected visual acuity, more with NMT than with MT (p = 0.005 and p = 0.04 after suture removal). Best-corrected visual acuity was approximately 2 decimal lines better following NMT. CONCLUSIONS: Zernike decomposition of corneal topography height data allows a separation and quantification of aberration of corneal graft surface from an ideal sphere. Although corneal surfaces with a high degree of local irregularities can be decomposed due to the orthogonality condition. Following NMT, SDF was markedly lower after suture removal.

Adult↗
PubMed1998

[Outcomes after penetrating keratoplasty in congenital hereditary corneal endothelial dystrophy (CHED). Report on 13 eyes].

BACKGROUND: Congenital hereditary endothelial dystrophy (CHED) is a rare bilateral corneal disease. The stromal opacity is supposed to result from terminal misdifferentiation of the endothelial cells. In this study we present the morphological and functional results after penetrating keratoplasty in children with CHED who were operated in our department between 1981 and 1997. PATIENTS AND METHODS: In a retrospective clinical cross-sectional study we looked up case histories of 13 eyes from 8 children (7 female, 1 male) with a mean age of 6.0 +/- 3.1 years (ranged from 3 to 14 years). In all children penetrating keratoplasty was performed by one surgeon (GOHN), in 3 eyes using nonmechanical excimer laser trephination. The graft-diameter was in 7 eyes 7.0/7.1 mm, in 2 eyes 7.0/7.2 mm, in 2 eyes 6.5/6.6 mm (resp. 6.8 mm), in 2 eyes 6.0/6.1 mm (resp. 6.2 mm). Fixation of grafts was achieved in 2 eyes by single running suture, in 8 eyes by double running suture and in 3 eyes by multiple interrupted sutures. RESULTS: During a mean follow-up of 4.0 +/- 2.4 years visual acuity increased in all patients (from light perception to 6/20 preoperatively to 2/200 to 14/20 postoperatively). In one patient corneal endothelial-epithelial-decompensation occured (both eyes unterwent previous antiglaucomatous surgery elsewhere), and in 1 patient loosening of one suture happened after 10 month. No immunological graft reaction occurred during follow-up. After excimer laser trephination (3 eyes from 2 patients) visual acuity and corneal astigmatism after surgery was favorable in comparison to all other patients. CONCLUSION: In children with CHED penetrating keratoplasty results not only in a clear cornea but also in a satisfactory functional outcome. Postoperatively periodical morphological controls and assessment of refraction as well as means to prevent amblyopia are indispensable before age 7.

Adolescent↗