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PubMed2005

Laparoscopic fenestration of a neonatally detected hepatic mesenchymal hamartoma.

We report a case of hepatic mesenchymal hamartoma that was detected neonatally and successfully treated by laparoscopic fenestration. A baby girl was referred to our hospital 9 days after birth with a cystic lesion in her liver. Screening abdominal ultrasonography revealed a sonolucent lesion measuring 65x43x40 mm in the right lobe of the liver with a small solid area. Magnetic resonance imaging depicted the lesion as hyperintense on both T1- and T2-weighted images with no enhancement. A laparoscopic biopsy and fenestration of the lesion was performed. Histologic examination of the cyst wall led to a diagnosis of hepatic mesenchymal hamartoma. The postoperative course was uneventful and the patient is doing well at 4 years' follow-up, with no recurrence.

Diagnosis, Differential↗
PubMed2000

Persistent pain related to root canal filling and apical fenestration: a case report.

Endodontic treatments may give rise to persistent pain whose origin is sometimes difficult to determine. Although it is unusual, pain may occur due to apical fenestrations following endodontic treatment. If this occurs, the solution is surgical intervention. This surgical procedure consists of raising a flap to expose the fenestration, followed by curettage of any overextended canal filling materials that may be potentially irritating to the underlying mucosa, remodeling of the apex, and its repositioning below the level of the cortical bone. A case is described that illustrates this clinical situation. The case also demonstrates information that can be obtained from tomodensitometric films.

Apicoectomy↗
PubMed2001

Effectiveness of adenoidectomy and laser tympanic membrane fenestration.

OBJECTIVE: Adenoidectomy alone or with tonsillectomy (A+/-T) is an effective surgical intervention in the management of otitis media in children, especially when it is performed in conjunction with insertion of pressure equalization tubes (PETs). Otorrhea and persistent tympanic membrane (TM) perforation are frequent complications. This study evaluates the effectiveness of intermediate duration middle ear ventilation using laser tympanic membrane fenestration (LTMF) without tube insertion and as an adjunct to adenoidectomy in resolving middle ear disease within the first 90 days after surgery. STUDY DESIGN: This pilot study was a multicenter, prospective clinical cohort trial. Institutional review board approval and informed consent were obtained. The study involved four tertiary care pediatric otolaryngology departments. Fifty children (96 ears) were treated with LTMF in conjunction with A+/-T from June 1, 1998, through March 30, 1999. Ages ranged from 9 months to 12 years. Patients undergoing A+/-T who would have been recommended for PET insertion instead underwent middle ear ventilation with LTMF using the Oto-LAM device (ESC/Sharplan, Yokneam, Israel). Patients were seen at 30, 60, and 90 days postoperatively. Resolution of otitis media with effusion was determined by clinical examination, which included pneumatic otoscopy, audiometry, and tympanometry. RESULTS: Of the treated ears, 88%, 86%, and 83% had clinical resolution of middle ear disease at 30, 60, and 90 days, respectively. Preoperatively, 45% (n = 85) of ears had normal hearing; 92% (n = 49) had normal hearing at 90 days. Eighty-nine percent (n = 92) had type C2 or B tympanograms preoperatively, and 12% (n = 60) had type C2 or B at 90 days. CONCLUSION: Laser tympanic membrane fenestration in conjunction with adenoidectomy was effective in restoring normal middle ear function at 90 days post-treatment in greater than 80% of children who otherwise may have had placement of PETs.

Adenoids↗
PubMed2001

The role of fenestrations and channels on the transverse motion of a soft contact lens.

PURPOSE: Ineffectual removal of potentially harmful species from the postlens tear film (POLTF) may lead to adverse responses among extended wearers of soft contact lenses. It is apparently important to remove bacteria, cell debris, and metabolic products from the postlens tear film to the outer tear lake; the flushing or dispersion rate of these species is enhanced by increasing fluid movement in the tear film driven by periodic lens motion. The contact lens moves laterally (up-down) and transversally (in-out) due to the action of the eyelid forces during blinking. Viscous drag in the POLTF resists lens motion. Consequently, any design change in the lens that reduces viscous drag increases motion and improves flushing of unwanted species from the POLTF. We investigate quantitatively the effect of channels cut on the back surface of the lens and fenestrations (holes) drilled through the lens on transverse lens motion. METHODS: We model the lens as a curved solid body with a periodic arrangement of channels/holes. The cornea is treated as a flat surface, and the hydrodynamic equations of motion are solved for Newtonian fluid transport in the POLTF assuming lubrication and creeping flow. POLTF pressure profiles, obtained by solving these equations, are integrated to determine the lens settling velocity in the transverse direction for a given amount of applied lid force. Lens settling velocity is then compared with the same velocity in the absence of channels/fenestrations. Further, we calculate the total transverse motion in a blink for lenses with and without channels/fenestrations to estimate the possible enhancement in transverse motion due to the channels/fenestrations. RESULTS: Variables that affect the fluid mixing in the POLTF are the postlens tear film thickness, lens thickness, channel length, depth and spacing, and the hole diameter, location, and spacing. We study the effect of each of these variables on the enhancement of transverse motion for channels and holes of diameters varying from 0.1 to 2 mm with spacing varying from 1 to 5 mm. CONCLUSIONS: We demonstrate that incorporation of channels and holes reduces viscous resistance and increases transverse lens motion, and thus increases fluid mixing and dispersive flushing from the POLTF. The increase in transverse motion depends strongly on the postlens tear film thickness. Enhancement of the transverse motion varies from a factor of about 2 to 20 depending on the particular lens design and the postlens tear film thickness. Because fluid mixing increases up to the square of the transverse motion, channels/holes are expected to render flushing of the POLTF considerably more effective. We find that channels and/or fenestrations, when appropriately designed, can provide significant improvement in flushing from the POLTF. This work provides a new quantitative tool for the efficient design of channels/holes in soft contact lenses.

Biomechanical Phenomena↗
PubMedDate not supplied

Visual outcomes for optic nerve sheath fenestration in pseudotumour cerebri and related conditions.

BACKGROUND: To determine the efficacy and safety of optic nerve sheath fenestration, and to identify factors predicting visual field (VF) and visual acuity (VA) in patients with progressive pseudotumour cerebri syndrome. METHODS: This retrospective observational case series studied 51 eyes of 32 patients with pseudotumour cerebri syndrome, by chart review and comparison of preoperative and postoperative examinations. Main outcome measures included VF, VA and complications. RESULTS: Postoperative VF mean deviation scores improved (P = 0.03) within 6 months when compared with preoperative VF. Multiple regression analysis demonstrated that eyes with mean deviation > or = -20 dB were associated with improved or stabilized VA at 6 months, odds ratio 7.5 and confidence interval (1.2, 46.1), P = 0.03. Eyes with VF defects outside 10 degrees of fixation were associated with improved or stabilized VF at 6 months odds ratio 9.7, 95% confidence interval 1.1, 85.9, P = 0.04. Five patients developed self-limiting complications from surgery. CONCLUSIONS: Optic nerve sheath fenestration is safe and effective in stabilizing or improving VF and VA in the short to medium term. Patients with mild VF loss improved following surgery, and patients with severe VF loss stabilized following surgery.

Adolescent↗
PubMed2005

Effects of bone morphogenetic protein-6 on periodontal wound healing in a fenestration defect of rats.

BACKGROUND: Bone morphogenetic proteins (BMPs) may play significant roles in bone formation. The ability of BMP-6 to promote wound healing has been chosen as the subject of this investigation. In this study, a synthetic rat BMP-6 polypeptide was applied to a periodontal fenestration defect in rats to elucidate the effects of BMP-6 on periodontal wound healing. MATERIAL AND METHODS: Following surgery to create a bony window on the buccal aspects of mandibular molar roots, 24 male Sprague Dawley rats were divided into four groups according to BMP application (0, 1, 3 and 10 microg, respectively). Animals were killed after 28 days and the mandible taken for histological examination. Histometric measurements were performed on sections selected from three levels (coronal, middle and apical levels; with 240 microm apart from the central) of the defect. New bone and cementum formation (including area and thickness) were analyzed and compared. RESULTS: In general, minimal new bone was observed on the surgically created defects in the non-BMP group, whereas a complete osseous healing occurred in all BMP-6 treated animals. New bone formation (both in area and thickness) was significantly influenced by both the dosage and the examining level, whereas new cementum formation was affected by dosage only. An increase in bone and cementum formation was noted in all three BMP groups when compared with the control group at all examined levels. Among the BMP groups, greatest new bone and cementum formation were noted in the 3 microg group. New cementum thickness increased on the cementum surfaces of the defects compared with the dentinal surfaces in all study groups. CONCLUSION: An increase in new bone and cementum formation was noted after applying a synthetic BMP-6 polypeptide to a periodontal fenestration defect in rats. Therefore, we suggest that BMP-6 may play a certain role in periodontal regeneration.

Alveolar Bone Loss↗
PubMed1982

Permeability of fenestrated capillaries in the isolated pig pancreas, with effects of bradykinin and histamine, as studied by simultaneous registration of filtration and diffusion capacities.

Combining an isogravimetric technique and a colorimetric 'on-line' method (Rippe & Stage 1978), filtration capacity (CFC) and diffusion capacity (PS) were simultaneously measured in the maximally vasodilated 'fenestrated' capillary bed of isolated, artificially perfused pancreatic glands in 12 juvenile pigs. Both CFC and PS for Cr-EDTA were about 20 times greater than in the 'continuous' capillary bed of skeletal muscle. With perfusate flow rates of 250 ml/min x 100 g during isogravimetry, PS-Cr-EDTA averaged 110 +/- 10.0 (S.E.) ml/min X 100 g, and diffusion limitation occurred first at flow rates above 300 ml/min X 100 g. CFC was independent of flow rate and averaged 0.641 +/- 0.027 ml/min X 100 g X mmHg. The parallel augmentation of PS-Cr-EDTA and CFC in the fenestrated capillary bed compared with continuous ones seems to reflect both a higher number of capillaries per unit tissue and an increased number of 'small pores' per unit capillary surface, whilst the 'large pore system' appears to be similar. Following bradykinin or histamine infusion, results were similar to those for continuous capillaries (e.g. Rippe, Kamiya & Folkow 1978). Thus, without further vasodilatation CFC increased 3-fold While PS-Cr-EDTA increased only some 25%, and subsequent isoprenaline infusion reversed these effects. Previous studies on continuous capillaries indicate that histamine-type agents act by opening additional 'large pores' in the venular exchange sections (cf. Rippe & Grega (1978, Svensjö 1978), while beta-adrenergic agonists block this effect. The results further suggest that the fenestrae are not involved in these bradykinin-histamine effects, but rather function as a high-density, small pore population.

Animals↗
PubMed1981

Fenestrated sheen macular dystrophy. A new autosomal dominant maculopathy.

A family is described showing small, grouped, red fenestrations of the macular region surrounding an intact foveolar reflex. The disease affected a father and his 2 daughters, and seems to be an autosomal dominant maculopathy. No functional abnormalities were disclosed and fluorescein angiography was normal. This family may represent the second family described with fenestrated sheen macular dystrophy.

Adolescent↗
PubMed1986

Benign intracranial hypertension: visual loss and optic nerve sheath fenestration.

Five patients with serious ocular complications of benign intracranial hypertension are described. Optic nerve sheath fenestration resulted in resolution of papilloedema with, in three instances, improvement in vision. Benign intracranial hypertension may not always be benign for vision and fenestration operations may prevent or reverse visual deterioration by an effect on the optic nerve rather than by reducing intra-cranial pressure.

Adult↗
PubMed1979

Treatment of postpneumonectomy empyema: the case for fenestration.

In Mearnskirk Hospital, Glasgow, 29 patients with postpneumonectomy empyema were treated by fenestration in a 12-year-period. Seven of these were not considered fit enough for definitive closure and died of continuing disease or respiratory infection. Twenty-two patients went on to closure of their fenestra, and in 17 (77%) the pneumonectomy space was rendered permanently sterile. If the empyema recurred treatment was repeated but proved less successful. Fenestration is an effective method of dealing with postpneumonectomy empyema, but also has several other advantages, particularly if the empyema is associated with a bronchopleural fistula.

Adult↗
PubMed1992

A comparison of hemilaminectomy (with concomitant disc fenestration) and dorsal laminectomy for the treatment of thoracolumbar disc protrusion in dogs.

The techniques of hemilaminectomy (with concomitant disc fenestration) and dorsal laminectomy were compared statistically in two groups of 30 dogs with thoracolumbar disc disease. On presentation all the dogs were unable to walk and were graded 1 to 3 according to their degree of neurological dysfunction. Nineteen had a previous history of thoracolumbar pain or hindlimb paresis. Radiography showed a narrowed disc space or extruded calcified disc material in 52 of the dogs and lumbar myelography revealed an extradural mass in 57; 24 of the dogs had clinical or myelographic lateralisation of signs. Hemilaminectomy significantly improved the ability to retrieve protruded disc material compared with dorsal laminectomy, and the removal of protruded disc material significantly improved the degree of recovery. Fenestration significantly reduced the recurrence of thoracolumbar disc disease.

Animals↗
PubMed1983

Are enlarged fenestrations in the internal elastic lamina of the rabbit thoracic aorta associated with poststenotic dilatation?

A stenosis amounting to 45-60% of the luminal diameter was made in the thoracic aorta of six New Zealand White rabbits. The progress of the ensuing poststenotic dilatation (PSD) was followed by daily X-ray analysis after which angiograms were taken for the calculation of luminal diameters. Specimens of the aorta proximal and distal (PSD) to the stenosis were digested to expose the internal elastic lamina (IEL) and viewed using a scanning electron microscope. The dilatations, which ranged between 7 and 30% reached their maximum diameter after only 8-10 days. The average diameter of the fenestrations distal (2.30 +/- 0.53 SEM) to the stenosis were significantly larger (p less than 0.01) than proximal (1.33 +/- 0.16 SEM) and covered a significantly larger (p less than 0.005) percent of the surface area of the IEL. It is suggested that the enlarged fenestrations may result in changes to the mechanical properties of the IEL which would play an important role in the genesis of PSDs.

Animals↗
PubMedDate not supplied

Aortic fenestration: a why, when, and how-to guide.

The management of aortic dissection can be challenging. Most cases of acute type A dissection are managed surgically. Most cases of acute type B dissection are managed medically, although open surgery or stent-graft placement is sometimes performed. Patients with type B or surgically treated type A dissection may develop vascular complications such as mesenteric or peripheral ischemia, which cannot be managed medically. Aortic fenestration is a method for decompressing the hypertensive false lumen by creating a hole in the distal part of the dissection flap. This procedure allows outflow from the false lumen, thereby reducing intraluminal pressure, relieving branch vessel obstruction, and reducing the risk of extension of the dissection. Urgent revascularization is required to correct mesenteric and renal ischemia and to reestablish distal perfusion if there is resting ischemia. Few operators will acquire extensive personal experience with percutaneous aortic fenestration. Nevertheless, with a good understanding of the pathologic condition, careful demonstration of the anatomy, good technical skills, and access to high-quality imaging (including intravascular ultrasonography) and the requisite equipment, most interventional radiologists skilled in arterial interventions should be capable of performing this procedure. However, because further interventions are frequently required, the radiologist needs to maintain contact with the patient to ensure timely treatment of any subsequent complications.

Aortic Dissection↗
PubMed2003

Multiple PV1 dimers reside in the same stomatal or fenestral diaphragm.

Several of the endothelium-specific structures that have been involved in microvascular permeability [such as caveolae, transendothelial channels (TECs), vesiculovacuolar organelles (VVOs), and fenestrae] can be provided with either a stomatal or fenestral diaphragm. In the case of fenestrae, the diaphragm has the presumed function of creating a permselective barrier for solutes from blood plasma and interstitium. PV1 is an endothelium-specific integral membrane glycoprotein that is associated with both the stomatal diaphragms of caveolae, TECs, and VVOs as well as the diaphragms of endothelial fenestrae. The intimate structure of these diaphragms has been shown to consist of a meshwork formed by radial fibrils. We have recently shown that PV1 is a key structural element of both types of diaphragms, with its expression being sufficient to form de novo stomatal and fenestral diaphragms in both endothelial and nonendothelial cell types in culture. We have further tested the role of PV1 in the structure of the diaphragms and demonstrate here that multiple PV1 homodimers reside in close proximity within the same diaphragm. Our data bring further support to the paradigm by which PV1 dimers would form the fibrils of the diaphragms with a function in the microvascular permeability.

Animals↗
PubMed1998

Avoiding complicated shunt systems by open fenestration of symptomatic fourth ventricular cysts associated with hydrocephalus.

Optimal treatment of the hydrocephalic patient with symptomatic Dandy-Walker malformation or trapped fourth ventricle remains controversial. We describe 6 patients with symptomatic Dandy-Walker malformation or trapped fourth ventricle and hydrocephalus that were treated with an aggressive cyst fenestration. Four of the 6 patients had previously undergone five or more failed shunt procedures. There were no complications associated with surgery, and 5 of the 6 patients (83%) have remained asymptomatic with respect to their posterior fossa cysts. One patient has required subsequent fourth ventricular shunt placement. Median follow-up was 26 months (range 12-66 months). We suggest that suboccipital craniectomy and open fenestration is a valid treatment option in hydrocephalic patients with symptomatic Dandy-Walker malformation or trapped fourth ventricle. Although the associated lateral ventriculomegaly will probably still require a ventriculoperitoneal shunt, the absence of a cystoperitoneal shunt system seems to minimize the incidence of complications and reoperation.

Adolescent↗
PubMedDate not supplied

Cell-mediated delivery of fibroblast growth factor-2 and vascular endothelial growth factor onto the chick chorioallantoic membrane: endothelial fenestration and angiogenesis.

Fibroblast growth factor-2 (FGF2) and vascular endothelial growth factor (VEGF) exert their angiogenic activity by interacting with endothelial cells in a distinct manner. In this study, we investigated the morphological features of endothelial cells of the chick embryo chorioallantoic membrane (CAM) microvasculature after stimulation with FGF2 or VEGF. In order to provide a continuous delivery of the growth factor, we utilized a recently developed gelatin sponge/CAM assay in which a limited number of FGF2- or VEGF-transfected cells were adsorbed onto gelatin sponges and applied on the top of the CAM on day 8 of development. Their angiogenic activity was compared to that exerted by a single bolus of the corresponding growth factor. All the angiogenic stimuli induced a comparable vasoproliferative response, as demonstrated by the appearance of similar numbers of immature blood vessels within the sponge on day 12. No angiogenic response was observed in CAMs implanted with the corresponding parental cell lines or vehicle. Electron microscopy demonstrated that VEGF-overexpressing cells modified the phenotype of the endothelium of the blood vessels at the boundary between the implant and the surrounding CAM mesenchyme. The endothelial lining of 30% of these vessels showed segmental attenuations, was frequently interrupted and became fenestrated, mimicking what is observed in tumor vasculature. In contrast, the vessels consisted of continuous endothelium sealed by tight junctions in all the other experimental conditions. These results indicate that FGF2 and VEGF interact with endothelial cells of the CAM in a distinct manner. Both growth factors induce a potent angiogenic response, but only VEGF delivered in a continuous manner by its transfectants can modify the phenotype of the otherwise quiescent endothelium of CAM blood microvessels. The gelatin sponge/CAM assay may constitute a new model to study the mechanisms leading to endothelial fenestration in tumor growth.

Adsorption↗
PubMedDate not supplied

Endoscopic cyst fenestration outcomes in children one year of age or less.

The use of endoscopic fenestration (EF) is becoming an increasingly common treatment for symptomatic intracranial cysts. Very little data exist regarding outcomes for this procedure in children 1 year of age or younger. We retrospectively reviewed the clinical outcomes of 8 children 1 year of age or less treated at our institution with endoscopic cyst fenestration. The mean follow-up was roughly 2.5 years. These data were combined with 17 other cases obtained from the published literature. EF was successful in rendering patients shunt-free or minimizing the number of ventricular catheters in 18 of 26 operations. There were 8 outright failures -- two in 1 patient. Given the risks and complications of cerebrospinal fluid shunting in children less than 1 year of age, we advocate the consideration of EF as initial treatment of symptomatic intracranial cysts.

Brain↗