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PubMedDate not supplied

Preparation of donor lamellar tissue for deep lamellar endothelial keratoplasty using a microkeratome and artificial anterior chamber system: endothelial cell loss and predictability of lamellar thickness.

BACKGROUND AND OBJECTIVE: To measure endothelial cell loss and predictability of lamellar thickness after preparing donor tissue for deep keratoplasty with an artificial anterior chamber and microkeratome. MATERIALS AND METHODS: A microkeratome set at a depth of 350 microm and a diameter of 9 mm was used to obtain ten lamellar lenticules from corneoscleral rims mounted in an artificial chamber. A punch trephine then was used to cut the donor tissue 7 mm in diameter. Specular microscopy was performed to evaluate endothelial cell density before the procedure, after cutting with the microkeratome, and after trephination. Pachymetry was performed to determine the predictability of lenticule thickness, before the procedure and after microkeratome incision. RESULTS: Mean post-microkeratome endothelial cell loss was 79 +/- 88 cells/mm2 and post-punch trephination was 85 +/- 94 cells/mm2. This represented a mean percentage loss of 3.2% and 3.5% for the respective steps of this procedure. Nine of the ten lenticules were cut within +/- 75 microm of the intended 350-microm thickness. CONCLUSIONS: Preparing donor lenticules for deep lamellar endothelial keratoplasty with a microkeratome with artificial chamber system caused a relatively small loss of endothelial cells (6.7% of the total) and a reproducible thickness. This may have advantages over manual preparation techniques.

Anterior Chamber↗
PubMed2006

[The role of connective tissue growth factor, transforming growth factor and Smad signaling pathway during corneal wound healing].

OBJECTIVE: To study the expression and location of connective tissue growth factor (CTGF) and transforming growth factor-beta(1) (TGF-beta(1)) protein and mRNA in rabbit cornea during the wound healing process. To assess the interaction between CTGF and TGF-beta(1), as well as the Smad signaling pathway involved. METHODS: Twenty-six Albino white rabbits were used as experimental animals and randomly divided into 4 groups: (1) CONTROL GROUP: two rabbits. (2) Simple corneal injury group: a 3 mm diameter and 0.05 mm depth corneal tissue was excised by a trephine at the anterior central cornea as a corneal wound model in 12 rabbits. Two rabbits were randomly sacrificed at 2 h, 6 h, 1 d, 3 d, 7 d and 21 d after the trauma. (3) TGF-beta(1) antibodies treated group: 6 rabbits were injected with TGF-beta(1) antibodies (15.5 microg) subconjunctivally after corneal trephine. Two rabbits were randomly sacrificed at 3 d, 7 d and 21 d after the injection. (4) Smad4 antibodies treated group: 6 rabbits were injected with Smad4 antibodies (20 microg) subconjunctivally after corneal trephine. Two rabbits were randomly sacrificed at 3 d, 7 d and 21 d after the injection. Protein of CTGF, TGF-beta(1), and FN was assessed with immunohistochemistry. CTGF and type one collagen mRNA were measured in by in situ hybridization. RESULTS: (1) CTGF protein or mRNA did not exist in normal rabbit corneas, but TGF-beta(1) protein was expressed in normal rabbit cornea epithelium. (2) Cornea fibroblasts activated 6 h after the operation. Expression of CTGF, TGF-beta(1), FN protein and mRNA of CTGF and type one collagen were upregulated after cornea injury, and reached the highest level in 3 days. The expression was reduced to the basal level 21 days later. (3) Injection of TGF-beta(1) antibodies reduced the expression of CTGF, TGF-beta(1) and FN in the cornea stroma and down-regulated the expression of CTGF in corneal epithelial cells. (4) Injection of Smad4 antibodies inhibited the expression of TGF in the stroma but did not change the expression of CTGF. CONCLUSIONS: Injury can upregulate the expression of CTGF, TGF-beta(1), FN and type one collagen proteins and mRNA of CTGF and TGF-beta(1). TGF-beta(1) and CTGF affect the wound healing process. TGF can induce the activation of corneal fibroblasts and upregulate the expression of CTGF. CTGF modulates the production of FN and Type one collagen. These data support the hypothesis that TGF-beta(1) and CTGF promote cornea scar formation and imply that the regulation of CTGF and TGF-beta(1) synthesis may be a therapy target for reducing corneal scarring.

Animals↗
PubMed1991

[Astigmatism in corneal graft. Prevention and treatment].

The tremendous development of the photokeratoscope and corneal topography analysis explains the development of corneal astigmatism study in corneal graft. Our study consists in a review of the bibliography. The prevention of the astigmatism needs the following: before the trephination, the astigmatism has to be treated (correction of against the rule astigmatism which is usual in the aphake people); during the trephination, to minimize the deformation of the eye ball, to choose a good diameter for the keratoconus case, to use a pneumatic trephine in order to have a perpendicular cut (the use of the laser Excimer seams promising); The suture of the corneal graft can be done with a double running suture 10/0 and 11/0. The 10/0 is removed at the third month, the visual recovery is faster but the average astigmatism is not as good as with the interrupted 10/0 sutures and running suture 11/0. This technique is good for an old patient or a one eyed people specially interested in a faster recovery of visual acuity. The second possibility is to use 16 interrupted sutures with and 11/0 running suture. With this technique, the sutures are removed selectively depending on the keratometry and the photokeratoscopy. The visual recovery is longer but the astigmatism at the end is very low. When all the sutures have been removed, the residual astigmatism can be treated when there is not any misalignement between the cornea and the graft. The keratometry, photokeratoscopy allows to find the meridian which is abnormal and to find out if the astigmatism is symmetrical or asymmetrical. The astigmatism is symmetrical if the deformation is the same at either side of the meridian. When the abnormal meridian is the steepest, the only thing to do is a relaxing incision (one or two if is asymmetric, two if the astigmatism is symmetric). The size of the relaxing incision is determined by the photokeratoscopy and the deepness by the effect obtained during surgery looking at a qualitative keratometer. On the table, the effect must be about 50% of over correction. When, the abnormal meridian is the flattest, the only thing to do is a wedge resection (if the astigmatism is asymmetric) or two wedge resections (if the astigmatism is symmetric). The size of the cuneiform resection is choosen with photokeratoscopy. The study of the literature about the Ruiz incision adapted to corneal graft cannot nowadays conclude to the accuracy and safety of this technique.(ABSTRACT TRUNCATED AT 400 WORDS)

Astigmatism↗
PubMed1990

[Effects of embryonal bone tissue on hemopoiesis].

The influence of human fetal bone (FB) on the hemopoietic and stromal cells were studied in the morphometric assay of the bone marrow trephine biopsy samples after a preliminary cultivation using the Marbrook system for 1-5 weeks. The rat FB effect on the hemopoiesis and survival were also studied in experiment with FB transplantation to rats with prior administration of lethal and sublethal doses of cyclophosphamide. In long-term cultivation of the bone marrow trephine biopsy samples, enhanced proliferation of the fibrous tissue and elimination of hemopoietic elements were seen. Combined cultivation of the trephine biopsy samples of the bone marrow and FB inhibited the fibrous tissue proliferation and enhanced the viability of the hemopoietic and lipid cells. Transplantation of the FB in experiment shortened the leukocytopenia period in rats after sublethal (300 mg/kg) and lethal (500 mg/kg) doses of cyclophosphamide and increased their survival.

Animals↗
PubMed1985

Location of the stress-bearing layers of the cornea.

In order to determine which layers of the corneal stroma bear the stress of the intraocular pressure, 6.0-mm nonpenetrating trephine incisions were made centrally in one eye of each of 16 adult albino rabbits. After epithelial healing, the central corneal thickness was measured over 3 hr at 50 mmHg intraocular pressure in both eyes of the anesthetized rabbits. The animals were then killed and the uniformity and depth of trephine cut determined histologically. The mean differences in swelling rates between the cut and the opposite uncut eyes for trephine incisions of different depths were as follows: 1 +/- 2 micron/hr for 8-20% depth, 5 +/- 2 micron/hr for 21-40% depth, and 14 +/- 3 micron/hr for 41-60% depth (P less than 0.01 for all groups). These results indicate that the intraocular tension is probably distributed across all the corneal stromal lamellae rather than being borne primarily by the anterior or posterior layers.

Animals↗
PubMed1977

[The consideration of topographic anatomy in ophthalmic surgery (author's transl)].

The fistulizing operations can be classified with regard to their topography to the Schlemm's canal into the precanalicular Elliot's trephining, the trephining in the region of the Schlemm's canal (intercanalicular) or of its next vicinity with scleral flap (goniotrephining with scleral flap), the sclerectomy in the region of the Schlemm's canal (intercanalicular) or of its next vicinity with scleral flap (trabeculectomy). If the trephining is performed retrocanalicularly, the scleral spur and the ciliary muscle are involved. Iridodialysis and haemorrhage from the circulus arteriosus iridis major may occur in the peripheral iridorhexis, which is recommended for the iridencleisis and for the iridectomy in acute glaucoma. The proof for the decompression of the intrascleral optical canal in central vein thrombosis by the surgical procedure reported by Vasco-Posada cannot be deduced when the topographic-anatomical circumstances are taken into consideration.

Eye↗
PubMed1995

Core decompression of the femoral head for avascular necrosis: indications and results.

OBJECTIVE: To evaluate the effectiveness and safety of core decompression in the treatment of avascular necrosis (AVN) of the femoral head. DESIGN: A case study. SETTING: The department of orthopedic surgery in a major university hospital. PATIENTS: All patients with AVN of the femoral head, stages I to IVA, were included regardless of the cause of the necrosis. Three hundred hips were available for analysis. The follow-up ranged from 2 to 12 years. INTERVENTION: Core decompression of the femoral head was performed with an 8-mm Michele trephine inserted from just below the greater trochanter into the centre of the necrotic lesion to within 5 mm of the articular surface. Two more trephine tracts were made with a 5-mm or 6-mm trephine. The normal portion of cancellous bone recovered from the intertrochanteric region was thinned with a rongeur and was placed loosely into the central decompression channel at the end of the procedure to serve as a graft. MAIN OUTCOME MEASURES: Anteroposterior and lateral radiographs, taken immediately before surgery and at the final follow-up, clinical hip evaluation according to the Harris scoring system, and the need for total hip replacement. RESULTS: One patient sustained a subcapital fracture 1 month after surgery due to a fall. There was one case of nonfatal pulmonary embolism, one case of pneumonia and one case of thrombophlebitis of the thigh. Forty-six percent of operatively managed hips showed no radiographic progression of disease compared with only 19% of nonoperatively managed hips. Thirty-five percent of the operatively managed hips required total hip replacement compared with 77% of nonoperatively managed hips. The results in hips with early (stages I and II) AVN were only slightly better than those of hips with advanced (stages III and IVA) disease. However, the results in hips with small areas of necrosis in both stages I and II were much better than those with larger lesions; only 7% of the former group required total hip replacement after decompression and cancellous bone grafting. CONCLUSIONS: Core decompression with cancellous bone grafting is a safe and effective procedure for the treatment of early AVN of the femoral head. Results with this form of treatment are considerably better than those obtained in patients treated nonoperatively. Decompression with or without bone grafting is the author's treatment of choice for patients with early AVN of the femoral head.

Bone Transplantation↗
PubMed1996

[African neurosurgery. 1: Historical outline].

This outline of the history of African Neurosurgery explains the role that North Africa has played in the Middle Ages in the development of Neurosurgery, the origins of the development of the latter in twentieth century, and the delay that African Neurosurgery still shows at the present time in the majority of African countries. On the papyrus of the pharaonic era, we have found the description of some neurosurgical procedures such as trephination and brain aspiration by a transphenoidal approach used before mummification. It is particularly trephination which summarizes the ancient history of African neurosurgery, as it was widely used throughout the continent, practised and taught by healers in African tribes. The technical concepts of trephination are based, to a great extent, on the descriptions of Arab physicians of the Middle Ages. It was at that time (Middle Ages) that several Arab physicians such as Avicenne, Rhazes, and Avenzhoer described many types of nervous system diseases and the techniques to treat them. But it was mainly Abulkassim Al Zahraoui (Abulkassis) who was the pioneer of neurosurgery as he devoted one volume of his treatise (made up of 30 volumes) to neurosurgery, a precise description of many aspects of neurosurgical pathology, its treatment, instruments and neurosurgical techniques. We have reported in this article five original extracts in Arabic which deal with skull fractures and their treatment, vertebro-medullary traumas and their treatment, hydrocephalus and its treatment, tumors of the skull vault and their treatment, and finally the basic knowledge of anatomy which is of great interest for a surgeon. The medical knowledge of that time which gave birth to medical schools and hospitals was transmitted progressively to Europe and played an important role in the development of medicine during the European Renaissance in the fifteenth and sixteenth centuries. During colonization, neurosurgical practice started and developed in many African countries, together with the development of the health system that the colonial forces initiated in general as soon as they had come to these countries. This neurosurgery practised in the departments of general surgery either by neurosurgeons or general surgeons took part in the birth and development of neurosurgery as an independent specialty, thanks to the combined efforts of some European and African pioneers. Modern neurosurgery was introduced and started to develop in African countries from 1960, and the teaching of this specialty in many African universities began between 1960 and 1970.

Africa↗
PubMed1997

[Treatment outcome in patients with chronic subdural hematoma with reference to age and concurrent internal diseases].

The chronic subdural hematoma (CSH) is a disease in elderly patients beyond the 5th decade. Treatment of CSH is normally a burr hole trephination and subdural drainage. Although this technique is simple, lethality is reported to be up to 20% in literature. The records of 314 patients with CSH were analyzed. Attention was focussed on complicating diseases and distribution of age. Patients were categorized neurologically before and after trephination using the Bender scale. The portion of patients suffering from cardiological diseases was 14.3%, 6.7% were treated by anticoagulants because of cardiac valve implant. Alcoholics were found in 15.9% of patients and hypertension in 12.8%. Complicating diseases were found in 51.3% of patients. Multiple internal diseases are likely to affect prognosis more than hematoma thickness. These patients also brought about a higher rate of infection (4.8%), secondary hemorrhages (2.5%), pneumonia (3%) and seizures (5%) after trephination. Lethality was highest in patients with diabetes mellitus, cardiogenic diseases and hypertension as well as in elderly patients. The latter have also a poor post-operative outcome: 22 patients died. In contrast to hematoma thickness and midline shift, which do not have any influence on outcome, prognosis is mainly determined by age, complicating diseases, hypertension and diabetes mellitus. The chronic subdural hematoma is often found in multi-morbid patients.

Adult↗
PubMed1996

[A study on neural regeneration after experimental epikeratophakia].

OBJECTIVE: To assess the effect of epikeratophakia (EKP) on corneal nerve regeneration and the recovery of corneal sensitivity. METHODS: 36 adult rabbits underwent epikeratophakia with either 0.2 mm or 0.3-0.35 mm circular trephination. A histochemical technique (acetylcholine esterase staining) was used to investigate the process of corneal nerve regeneration, and the recovery of corneal sensitivity was determined in 36 rabbits at various intervals after EKP. RESULTS: The corneal sensory nerves began to regenerate just peripheral to the host-donor interface 3 weeks following EKP, the nerve fibers traveled toward the stroma of the lenticules at 2 months, and formed a sparse subepithelial plexus at 8 months after surgery. A relative hyposthesia was found in the central zone of the lenticule when compared with its peripheral zone 4 months postoperatively. The sensitivity of the central zone remained lower at 5-8 months after EKP though it had remarkably increased. The density of re-innervated fibers was higher in the shallow incision than that in deeper one. CONCLUSION: It is suggested that the factors affecting the corneal innervation and the recovery of corneal sensitivity following EKP include; (1) the scar formation as a barrier; (2) the adaptation to the micro-environment around the lenticule; and (3) the depth of trephine cut. Therefore, a 0.2-0.25 mm depth of trephine incision is advantageous to the lamellar dissection, graft suturation and corneal nerve regeneration.

Animals↗
PubMed1989

Low cost device for removing human and small primate temporal bone plugs.

Previously, only the expensive oscillating saw and Schuknecht temporal trephine were available for removing human temporal bone plugs and no trephines were made for smaller research primates. An inexpensive hole saw has been modified for removing such plugs with an electric drill. This device is less expensive, easier to use, causes less potential impact damage to the plug, and the size of the hole saw can be varied for the size of the skull.

Animals↗
PubMed1988

Technique, indications, and complications of percutaneous needle puncture.

One hundred and forty-five percutaneous needle punctures (PNP) of the brain and ventricles in 100 consecutive patients were retrospectively re-evaluated. This was to elucidate technical problems and complications of this method, which presents an alternative to the classical burr hole trephination with the insertion of a catheter. In 61% percutaneous needle trephinations (PNT) were performed, in 27% a pre-existing burr hole was used, and in 12% the open fontanelle. The method proved to be simple and effective, especially in emergency cases, and it had a very low rate of serious complications with 1.4% infections and 0.7% symptomatic bleedings, which had no permanent consequences.

Adolescent↗
PubMed1991

Prognostic value of immunocytologic detection of bone marrow metastases in neuroblastoma.

BACKGROUND: Morphologic evaluation of bone marrow for neuroblastoma cells is a routine and important component of clinical staging. Specific immunostaining of malignant cells with monoclonal antibodies should be more sensitive, however, and may improve the detection of metastases and provide additional prognostic information. METHODS: We looked for tumor cells in bone marrow from 197 patients with newly diagnosed neuroblastoma, using immunoperoxidase staining with monoclonal antibodies (immunocytologic analysis) and examination of smears and specimens obtained by trephine biopsy (conventional analysis). RESULTS: Routine smears and trephine-biopsy specimens were positive for tumor cells in 46 percent of the patients, whereas 67 percent were positive on immunocytologic analysis (P less than 0.0001). Immunocytologic analysis detected bone marrow metastases in 34 percent of patients considered to have only localized or regional disease (Stage I, II, or III). It also identified tumor cells that were not detected by conventional analysis in patients with widespread disease (Stage IV or IVS). Tumor content, as determined by immunocytologic analysis, predicted clinical outcome in relation to the age of the patient at diagnosis. Patients with Stage II or III disease diagnosed after one year of age who did not have occult marrow metastases did well, whereas those with metastases did poorly (P = 0.006). Patients in whom Stage IV disease was diagnosed before they were one year of age did well if bone marrow metastases were few or absent, but had poor survival if the marrow contained more than 0.02 percent tumor cells (P = 0.03). CONCLUSIONS: Immunocytologic analysis of bone marrow aspirates is more sensitive than conventional analysis in detecting tumor cells and provides prognostic information. The relations among marrow metastases, age at diagnosis, and clinical outcome illustrate the biologic heterogeneity of neuroblastoma.

Age Factors↗
PubMed2004

Concepts of neurosurgical management of chronic subdural haematoma: historical perspectives.

The history of chronic subdural haematoma (CSH), spanning from its possibly earliest beginnings throughout the centuries until the early 1980s, was investigated within the context of four different epochs. In the 'era of uncertainty', successful trephination, the modem method of choice for the treatment of CSH, was developed by neolithic men. Various historical sources indicate that patients with CSH might have undergone surgery at that time. CSH might have been one of the ailments that had spectacular courses of salvation after trephination. The entity of CSH was first described in the 'era of pioneers' in the seventeenth century by Johann Jacob Wepfer. The misconception of 'pachymeningitis hemorrhagica interna' was introduced by Rudolf Virchow in 1857. By the end of the nineteenth century it became more widely accepted that trauma was a possible cause of CSH. Successful neurosurgical treatment of CSH was first reported by Hulke in 1883. Putnam and Cushing, in 1925, focused on surgery as the treatment of choice for CSH. In the 'era of diagnostic refinement', the introduction of pneumencephalography and angiography allowed the diagnosis of CSH much earlier. Subsequently, the typical signs and symptoms of patients suffering from CSH changed from apathy and coma to headaches and discrete focal neurological symptoms. In the 'era of surgical routine', neurosurgical approaches became smaller and less invasive. Removal of the haematoma was identified as the primary goal of surgery. The use of closed system drainage markedly improved reexpansion of the brain after surgery. Burr hole craniostomy and twist drill craniostomy became the surgical treatment of first choice because of their low morbidity and mortality. There is growing evidence, however, that the neurosurgical learning curve has reached a plateau.

Cerebral Angiography↗
PubMed1997

Repairing holes in the head: a history of cranioplasty.

Cranioplasty is almost as ancient as trephination, yet its fascinating history has been neglected. There is strong evidence that Incan surgeons were performing cranioplasty using precious metals and gourds. Interestingly, early surgical authors, such as Hippocrates and Galen, do not discuss cranioplasty and it was not until the 16th century that cranioplasty in the form of a gold plate was mentioned by Fallopius. The first bone graft was recorded by Meekeren, who in 1668 noted that canine bone was used to repair a cranial defect in a Russian man. The next advance in cranioplasty was the experimental groundwork in bone grafting, performed in the late 19th century. The use of autografts for cranioplasty became popular in the early 20th century. The destructive nature of 20th century warfare provided an impetus to search for alternative metals and plastics to cover large cranial defects. The metallic bone substitutes have largely been replaced by modern plastics. Methyl methacrylate was introduced in 1940 and is currently the most common material used. Research in cranioplasty is now directed at improving the ability of the host to regenerate bone. As modern day trephiners, neurosurgeons should be cognizant of how the technique of repairing a hole in the head has evolved.

Animals↗
PubMed1999

[Autogenic bone plug to seal burr holes: technical note].

Many neurosurgical procedures can be performed by a single burr hole: neuro-endoscopy, microvascular decompression, stereotactic procedures, chronic subdural haematomas. It is technically difficult to suture and close the dura, located at the bottom of such holes, which can lately lead to CSF leakage. On the other hand, the surgical material used to seal the burr holes can be divided in heterogenic (metal screws, silicon plugs, gelfoam, bone wax, metilmetacrilate, hydroxyapatite), and autogenic (fat, aponeurosis, muscle, and bone dust from trephination). The heterogenic group always brings the possibility of foreign body reaction, which can complicate the procedure lately, ensuing a new surgical procedure to clean up the area. It also favors infection. We present a simple, economic, and biologically compatible "autogenic bone plug" to seal burr holes using the bone dust from the original trephination packed with surgical. The incidence of CSF fistulae on that procedures performed by a single burr hole lowered to almost zero, and foreign body reaction was not observed to present.

Biocompatible Materials↗
PubMed1997

Operative treatment of frontal sinusitis.

When the medical therapy fails trephination is the primary operation indicated in acute eroding sinusitis when drainage is necessary to avoid severe complications. In recent years also endoscopic transnasal surgery has been recommended for exenteration of the underlying disease in the ostiomeatal unit as well as for opening of the obstructed nasofrontal duct in acute phase of the disease. In Turku University Central Hospital endoscopic frontal sinus surgery is still reserved for cases with prolonged or delayed disease performed as a secondary operation after trephination and CT examination. Failures are common after these operations and both types of surgical treatment may be needed. Three percent of our patients developed a persistent chronic infection inside the frontal sinus. In these cases external osteoplastic approach is recommended. In these operations we have used bioactive glass as obliteration material with promising clinical results.

Biocompatible Materials↗
PubMed2004

Transcranial echo-guided transsphenoidal surgical approach for the removal of large macroadenomas.

OBJECT: Transsphenoidal surgery for the removal of macroadenomas has some disadvantages, including the risk of performing procedures without adequate visualization, difficulties in estimating the amount of residual tumor, and the risk of injuring major vessels. To overcome these disadvantages, the authors have developed transcranial echo-guided transsphenoidal surgery. METHODS: Three patients with large macroadenomas and two patients with irregularly shaped macroadenomas were selected for this operation. In addition to standard preparations for transsphenoidal surgery, in each case the right frontal bone was trephined and an echo probe was inserted transdurally through the trephination hole. During tumor removal, brightness-mode echo images and Doppler color flow images were obtained. The echo images allowed for real-time visualization of the tumor and surrounding brain structures including major arteries and the cisterns; histological heterogeneities of the tumor could also be appreciated. The tumors were removed safely and maximal tumor removal was achieved. CONCLUSIONS: Transcranial echo-guided transsphenoidal surgery provides real-time visualization of tumor removal. The method enhances the safety of this surgery, maximizes the removal of the tumor, and is inexpensive.

Adenoma↗