• 제목/요약/키워드: Fenestrations

검색결과 20건 처리시간 0.027초

간소엽내 동모양혈관내피창에 관한 주사전자현미경적 연구 (A Scanning Electron Microscopic Study on the Sinusoidal Fenestrations in the Hepatic Lobule of Normal Rat)

  • 고성은;신영철
    • Applied Microscopy
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    • 제25권4호
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    • pp.62-70
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    • 1995
  • 간소엽에 있는 동모양혈관내피창은 혈관과 간세포사이의 물질교환에 중요한 역할을 하는 부위로 알려져 있다. 그러나 이들 내피창에 관해서는 아직도 검토되어야 할 문제가 많이 남아 있다. 본 연구에서는 동모양혈관내피창 중 특히 큰창의 실재 여부와 창의 소엽내 분포상을 관찰하고 창의 크기와 분포상을 기초로 하여 내피창의 유형과 분포상을 재검토하고자 하였다. 실험동물은 식이조건을 일정하게 하기 위하여 최종 식이 투여 3시간 후에 관류고정하였으며 식에 따라 제작된 모든 조직표본은 주사전자현미경으로 관찰하였다. 그 결과 동모양혈관의 내면에서 여러가지 크기의 내피창이 관찰되었는데 이들은 작은창, 중간창 및 큰창의 3가지 유형으로 구분되었다. 작은 창은 낱개로 나타나거나 여러 개가 모여서 나타났으며 중간창은 낱개로 또는 작은창에 섞여서 나타났다. 큰 창도 낱개로 나타나거나 작은창과 중간창에 둘러싸여 나타났다. 특히 중간창은 소엽의 중심대에 많이 분포하는 경향이 있어 새로운 유형으로 분류하였다. 큰창은 다른 유형의 창과 마찬가지로 그 윤곽이 평탄하였으며 세포질에 의해 분할된 상도 관찰되었으나 파열된 상은 찾아 볼 수 없었기 때문에 인공산물이 아닐 것으로 추정하였다. 소엽은 창의 분포에 따라 주변대, 중간대 및 중심대로 구분되었다. 주변대에서는 작은창만이 보이는 동모양혈관이 많이 관찰되었다. 중심대에서는 중간창과 작은창이 보이는 동모양혈관이 많이 관찰되었다. 중간대에서는 큰창과 중간창 및 작은창이 다 같이 보이는 동모양혈관이 많이 관찰되었다. 이상의 소견으로 미루어 동모양혈관내피창은 소엽의 주변대에서 중간대로 가면서 점차적으로 커지다가 중간대에서 중심대로 가면서 작아지는 경향을 보이지만 중심대의 창은 주변대의 것에 비하면 큰 편이다.

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An Experimental Study on the Biomechanical Effectiveness of Bone Cement-Augmented Pedicle Screw Fixation with Various Types of Fenestrations

  • Yoon, Sang Hoon;Lee, Sang Hyung;Jahng, Tae-Ahn
    • Journal of Korean Neurosurgical Society
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    • 제65권6호
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    • pp.779-789
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    • 2022
  • Objective : To analyze the effects of the number and shape of fenestrations on the mechanical strength of pedicle screws and the effects of bone cement augmentation (BCA) on the pull-out strength (POS) of screws used in conventional BCA. Methods : For the control group, a conventional screw was defined as C1, a screw with cannulated end-holes was defined as C2, a C2 screw with six pinholes was defined as C3, and the control group type was set. Among the experimental screws, T1 was designed using symmetrically placed thru-hole type fenestrations with an elliptical shape, while T2 was designed with half-moon (HM)-shaped asymmetrical fenestrations. T3 and T4 were designed with single HM-shaped fenestrations covering three pitches and five pitches, respectively. T5 and T6 were designed with 0.6-mm and 1-mm wider fenestrations than T3. BCA was performed by injecting 3 mL of commercial bone cement in the screw, and mechanical strength and POS tests were performed according to ASTM F1717 and ASTM F543 standards. Synthetic bone (model #1522-505) made of polyurethane foam was used as a model of osteoporotic bone, and radiographic examinations were performed using computed tomography and fluoroscopy. Results : In the fatigue test, at 75% ultimate load, fractures occurred 7781 and 9189 times; at 50%, they occurred 36122 and 82067 times; and at 25%, no fractures occurred. The mean ultimate load for each screw type was 219.1±52.39 N for T1, 234.74±15.9 N for T2, 220.70±59.23 N for T3, 216.45±32.4 N for T4, 181.55±54.78 N for T5, and 216.47±29.25 N for T6. In comparison with C1, T1, T2, T3, T4, and T6 showed significantly different ultimate load values (p<0.05). However, when the values for C2 and the fenestrated screws were evaluated with an unpaired t test, the ultimate load value of C2 significantly differed only from that of T2 (p=0.025). The ultimate load value of C3 differed significantly from those of T1 and T2 (C3 vs. T1 : p=0.048; C3 vs. T2 : p<0.001). Linear correlation analysis revealed a significant correlation between the fenestration area and the volume of bone cement (Pearson's correlation coefficient r=0.288, p=0.036). The bone cement volume and ultimate load significantly correlated with each other in linear correlation analysis (r=0.403, p=0.003). Conclusion : Fenestration yielded a superior ultimate load in comparison with standard BCA using a conventional screw. In T2 screws with asymmetrical two-way fenestrations showed the maximal increase in ultimate load. The fenestrated screws can be expected to show a stable position for the formation of the cement mass.

The Incidence and Clinical Significance of Fenestrations in the Horizontal Segment of the Anterior Cerebral Artery Detected by Conventional Angiography and Magnetic Resonance Angiography

  • Kim, Tae-Ho;Lee, Hyun-Koo;Rhee, Jong-Joo;Lee, Seung-Jun;Lee, Chae-Heuck;Kim, Myoung-Soo
    • Journal of Korean Neurosurgical Society
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    • 제40권2호
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    • pp.74-78
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    • 2006
  • Objective : We examined the incidence of fenestration in the proximal segment of the anterior cerebral artery[ACA] and reviewed its clinical significance. Methods : Cerebral angiography was performed in 843 patients and magnetic resonance angiography[MRA] in 1,787; all patients had, or were suspected to have, cerebrovascular disease. We subsequently reviewed the angiography and MRA data. Results : Fourteen patients [six men and eight women, $35{\sim}81$ years of age, median age = 67 years] had proximal ACA fenestrations. Three of the 843 patients [0.36%] undergoing cerebral angiography had fenestrations of proximal ACA as did eleven of the 1,787 MRA patients [0.62%]. Seven fenestrations were located on the right side and seven fenestrations were located on the left side. The fenestrated ACA in one patient was associated with a saccular aneurysm at its proximal end. None of the 120 patients who underwent both conventional cerebral angiography and cranial MRA showed fenestration of proximal ACA. Conclusion : Although fenestration of ACA has little clinical significance, knowledge and recognition of this condition is important in the interpretation of cerebral images, especially during neurosurgical procedures.

교정 치료와 관련된 하악 전치부 협측 치은 퇴축의 위험성을 최소화하기 위한 골이식 : 증례보고 (Hard tissue augmentation to minimize a risk of buccal gingival recession in lower anterior teeth associated with orthodontic treatment: case report)

  • 유지수;백승진;정재숙;지숙
    • 대한치과의사협회지
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    • 제56권4호
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    • pp.208-216
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    • 2018
  • Patients with malocclusion may present with preexisting mucogingival problems susceptible to attachment loss during or after orthodontic treatment. Lower anterior teeth especially show a high prevalence of gingival recession following orthodontic treatment. This case report demonstrates hard tissue augmentation of labially thin or deficient alveolar bone (dehiscences and fenestrations) to prevent attachment loss during or after orthodontic treatment. Three patients presented clinically prominent root surfaces and dehiscences and fenestrations on cone-beam computed tomography (CBCT) in lower anterior teeth. Labial hard tissue augmentation of lower anterior teeth was performed with deproteinized bovine bone mineral and collagen membrane. Six months later, hard tissue augmentation reduced root prominence and created a greater volume of hard tissue on lower anterior area in clinical and radiographic findings. Hard tissue augmentation using xenograft could prevent attachment loss associated with orthodontic treatment and maintain stability of healthy periodontium.

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Three-Dimensional Angiographic Demonstration of Plexiform Fenestrations of the Proximal Anterior Cerebral Artery Associated with a Ruptured Aneurysm

  • Koh, Jun-Seok;Lee, Seung-Hwan;Bang, Jae-Seung;Kim, Gook-Ki
    • Journal of Korean Neurosurgical Society
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    • 제44권5호
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    • pp.338-340
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    • 2008
  • A rare case of ruptured aneurysm associated with multiple $A_1$ fenestrations resembling plexiform network was demonstrated by 3D angiography. A 56-year-old female presented with a ruptured aneurysm in the $A_2$ segment of the left distal anterior cerebral artery associated with the right $A_1$ fenestration. The ruptured aneurysm was occluded with surgical neck clipping via interhemispheric approach without neurological deficit. Plexiform fenestrations of the right distal $A_1$. opposite side to the left ruptured $A_2$ aneurysm, were clearly visible on postoperative 3D angiography. Our case may strongly support the theory described by Paget, namely that a remnant of the plexiform anastomosis between the primitive olfactory artery and $A_1$ segment is the source of such fenestration.

Alveolar bone thickness and fenestration of incisors in untreated Korean patients with skeletal class III malocclusion: A retrospective 3-dimensional cone-beam computed tomography study

  • Oh, Song Hee;Nahm, Kyung-Yen;Kim, Seong-Hun;Nelson, Gerald
    • Imaging Science in Dentistry
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    • 제50권1호
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    • pp.9-14
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    • 2020
  • Purpose: The purpose of this study was to evaluate vertical bone loss and alveolar bone thickness in the maxillary and mandibular incisors of patients with skeletal class III malocclusion. This study also aimed to evaluate the periodontal condition of class III malocclusion patients who had not undergone orthodontic treatment. Materials and Methods: The sample included cone-beam computed tomography scans of 24 Korean subjects (3 male and 21 female). Alveolar bone thickness (ABT), alveolar bone area (ABA), alveolar bone loss (ABL), and fenestration of the maxillary and mandibular incisors were measured using 3-dimensional imaging software. Results: All incisors displayed an ABT of less than 1.0 mm from the labial surface to root level 7 (70% of the root length). A statistically significant difference was observed between the mandibular labial and lingual ABAs and between the maxillary labial and mandibular labial ABAs. The lingual ABA of the mandibular lateral incisors was larger than that of the mandibular central incisors. ABL was severe on the labial surface. A statistically significant difference was observed between the maxillary and mandibular labial ABL values(21.8% and 34.4%, respectively). Mandibular lingual ABL (27.6%) was significantly more severe than maxillary lingual ABL (18.3%) (P<0.05). Eighty-two fenestrations were found on the labial surfaces of the incisors, while only 2 fenestrations were observed on the lingual surfaces. Fenestrations were most commonly observed at root level 6. Conclusion: Careful evaluation is needed before orthodontic treatment to avoid iatrogenic damage of periodontal support when treating patients with class III malocclusion.

Fenestration and Duplication of the Vertebrobasilar Artery Detected by Conventional Angiography and Magnetic Resonance Angiography

  • Ahn, Jae-Heung;Kim, Myoung-Soo;Lee, Hyun-Koo;Lee, Seung-Jun;Park, Hyo-Il;Lee, Chae-Heuck
    • Journal of Korean Neurosurgical Society
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    • 제39권5호
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    • pp.355-359
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    • 2006
  • Objective : The purpose of our study is to examine the clinical significance of vertebrobasilar artery[VBA] fenestration and duplication. In addition, we review its incidence and pathogenesis. Methods : Cerebral angiography was performed in 803 patients and magnetic resonance angiography[MRA] in 880; the patients had or were suspected to have cerebrovascular disease. We retrospectively reviewed angiography and MRA. Results : Fifteen patients [eight men, seven women, 3 to 77 years of age, median age = 58 years] had a VBA fenestration and duplication. Seven [7/803 = 0.87%] of the patients undergoing cerebral angiography revealed fenestrations and one duplication of VBA. Ten patients [10/880 = 114%] among 880 patients that underwent MRA demonstrated fenestration of basilar artery[BA]. Two of 66 patients that underwent both conventional cerebral angiography and cranial MRA showed a fenestration of BA. Twelve fenestrations were located in the proximal portion of the BA and one was in the mid portion of the BA. One vertebral artery[VA] fenestration was located in the intracranial portion of the right VA, and one VA duplication was at the level of $C_{1-2}$ in the left VA. Conclusion : In addition to medial defects, flow phenomena at the proximal end of fenestrations, where hemodynamic stress and increased turbulence are present, may contribute to aneurysm formation. And arterial fenestration is a predisposing factor in vascular injury and cerebral ischemia.

노인 급성 외상성 경막하출혈 환자에서 시행한 다발성 경막천공술의 이용 (The Use of Multiple Fenestrations of the Dura in Acute Traumatic Subdural Hematoma in Elderly)

  • 박종태;윤지광
    • Journal of Trauma and Injury
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    • 제26권3호
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    • pp.226-228
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    • 2013
  • Elderly patients with acute subdural hematomas have higher mortality and lower functional recovery rates compared with those of other head-injured patients. Early and widely surgical decompression and active intensive care represent the best way to assist these patients. However, abrupt decompression of the hematoma can lead to brain disruption and secondary ischemia in the brain surrounding the craniectomy site. Acute brain swelling and brain extrusion, which take place shortly after decompression, can lead to a catastrophic situation during the operation due to the impossibility of appropriate closure of the dura and scalp. To avoid the deleterious consequences of disruption of brain tissue, we have adopted multiple fenestrations of the dura in a mesh-like fashion and gradual release of subdural clots through the small dural openings that are left open. This is especially important in cases in which there are massive amount of subdural hematomas with small parenchymal lesion and severe midline shifts in elderly patients. Further clinical experiences should be conducted in a more selected series patients to estimate the impact of this technique on morbidity and mortality rates.

Clinical and Neuroimaging Outcomes of Surgically Treated Intracranial Cysts in 110 Children

  • Lee, Eun-Jung;Ra, Young-Shin
    • Journal of Korean Neurosurgical Society
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    • 제52권4호
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    • pp.325-333
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    • 2012
  • Objective : The indications and optimal surgical treatments for intracranial cysts are controversial. In the present study, we describe long-term clinical and neuroimaging results of surgically treated intracranial cysts in children. The goal of this study is to contribute to the discussion of the debate. Methods : This study included 110 pediatric patients that underwent surgeries to treat intracranial cysts. Endoscopic cyst fenestrations were performed in 71 cases, while craniotomies and cyst excisions (with or without fenestrations) were performed in 30 patients. Cystoperitoneal shunts were necessary for nine patients. Long-term results were retrospectively assessed with medical and neuroimaging records. Results : Clinical and radiological improvement was reported in 87.3% and 92.8% of cases, respectively, after endoscopic neurosurgery, and in 93.3% and 100% using open microsurgery whereas 88.9% and 85.7% after shunt operation. There were no statistical differences in clinical outcomes (p=0.710) or volume reductions (p=0.177) among the different surgeries. There were no mortalities or permanent morbidities, but complications such as shunt malfunctions, infections, and subdural hematomas were observed in 56% of the patients that had shunt operations. A total of 13 patients (11.8%) underwent additional surgeries due to recurrences or treatment failures. The type of surgery performed did not influence the recurrence rate (p=0.662) or the failure rate (p=0.247). Conclusion : Endoscopic neurosurgeries are less invasive than microsurgeries and are at least as effective as open surgeries. Thus, given the advantages and complications of these surgical techniques, we suggest that endoscopic fenestration should be the first treatment attempted in children with intracranial cysts.

삼중방심 치험 1례 (Cor Triatriatum A Case Report)

  • 노중기;이길노
    • Journal of Chest Surgery
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    • 제18권1호
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    • pp.13-18
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    • 1985
  • Cortriatriatum is rare congenital heart disease characterized by the presence of a fibromuscular diaphragm that subdivides the left atrium into a proximal or "accessory" and a distal or "true" left atrial chamber. A 15 year old girl with cortriatriatum underwent surgical correction at the department of Thoracic and Cardiovascular Surgery, Soonchunhyang College in November, 1984. This case was preoperatively diagnosed as a single atrium with functional tricuspid regurgitation But on operation, we found that there were transverse septum in the left atrium through large ASD, low chamber receives the pulmonary veins, and the upper chamber gives rise to the left atrial appendage and leads to the mitral valve. And the anomalous membrane has no fenestrations. We excised completely the anomalous septum, reconstructed atrial septal defect with dacron patch and performed the tricuspid annuloplasty with DeVega method. Postoperative course was uneventful during follow up, during follow up.

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