Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FENESTRATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources

Filtration effect of endothelial fenestrations on chylomicron transport in neonatal rat liver sinusoids.

The function of endothelial fenestrations in the control of the passage of chylomicrons from the blood to the liver parenchymal cells was studied ultrastructurally in neonatal rats. Measurement of circulating chylomicrons and endothelial fenestrations as well as chylomicrons in the space of Disse at 2--20 h after the onset of suckling revealed a substantial filtration effect of endothelial fenestrations on chylomicrons larger than 250 nm in diameter. Direct uptake of chylomicrons by parenchymal cells was observed to occur by pinocytosis; Kupffer cells endocytosed only very few chylomicrons, and endothelial cells were inactive in this respect.

Animals↗

The cell surface of a restrictive fenestrated endothelium. I. Distribution of lectin-receptor monosaccharides on the choriocapillaris.

The choriocapillaris is one example of a capillary bed lined by a fenestrated endothelium that is restrictive to exogenous tracers and endogenous plasma proteins. In this study we have examined the distribution of cell-surface monosaccharides utilizing biotinylated lectin-avidin ferritin cytochemistry. Receptors for wheat germ agglutinin were localized to the plasmalemma and diaphragms of some fenestrae, vesicles, and channels at the luminal endothelial front in amounts greater than seen for the other lectins employed. The absence of labeling following inhibition with N-acetylglucosamine and after tissue digestion with N-acetylhexosaminidase, but not after neuraminidase indicated that this lectin marked N-acetylglucosamine residues and not sialic acid. Wheat germ agglutinin receptors were not affected by pronase E or trypsin digestion, but were partially removed by proteinase K. The latter also removed many fenestral diaphragms. Wheat germ agglutinin receptors were cleaved with endoglycosidase D. The combined results indicate that the wheat germ agglutinin receptor is of the low-mannose type and part of a protein with hydrophobic properties. Receptors for concanavalin A (mannose) and Ricinus communis agglutinin (galactose) were also localized to the plasmalemma and endothelial diaphragms. The examination of sections at different tilt angles revealed that these lectins bound to the endothelium in a non-random distribution, encircling diaphragms of fenestrae and channels. Soybean agglutinin (N-acetylgalactosamine) marked endothelial structures sparsely. Following digestion with pronase E or trypsin, receptor sugars for the latter three lectins were completely removed, indicating their presence on protease susceptible glycoproteins. These findings demonstrate that the endothelium of the choriocapillaris bears carbohydrate moieties that are different than those described for permeable fenestrated endothelia.

Animals↗

Fenestration of the vertebrobasilar junction.

A fenestration of the vertebrobasilar junction was found in an 80-year-old man during autopsy. It was associated with thrombosis of the vertebral arteries which had caused a left Wallenberg syndrome. The left limb of the fenestration presenting the same transverse diameter as that of the remaining part of the basilar artery appeared to be its direct (true) origin. The right limb had a lesser transverse diameter and appeared to bridge the lateral surface of the rostral end of the right vertebral artery and the basilar trunk. According to the authors, this fenestration could have been caused by the persistence of the cranial part of a primitive lateral vertebrobasilar anastomosis, rather then by the usual incomplete fusion of the primitive paired basilar arteries.

Aged↗

Structure and distribution of lymphatic capillaries and fenestrated blood capillaries in the conduction system of the rabbit heart.

The distribution and structure of lymphatic and blood capillaries in the rabbit heart conduction system were investigated by transmission electron microscopy. The sinuatrial node, atrioventricular node, and atrioventricular bundle possessed a rich network of lymphatic capillaries, which were situated not only at the periphery but also in the interior of the conduction system. The fine structure of these lymphatic capillaries was essentially similar to those within the atria and the ventricles. Although blood capillaries within working myocardium were nonfenestrated, the heart conduction system was often supplied by fenestrated blood capillaries. In the atrioventricular node and bundle especially, fenestrated blood capillaries and lymphatic capillaries were topographically associated, forming an extensive microcirculatory system. The presence of fenestrated capillaries suggests that a fast transcapillary passage of metabolites occurs in these regions, while the lymphatic capillaries may play an important role in the removal of macromolecules and excess intercellular fluid.

Animals↗

Fenestration of the anterior cerebral artery.

Three cases of angiographically demonstrated fenestration of the anterior cerebral artery are reported. Fenestration occurred at the medial half of the horizontal segment of the anterior cerebral artery in all cases. Its embryology and clinical significance are briefly discussed, and the anatomical and radiological literature on fenestration of the anterior cerebral artery is reviewed.

Adult↗

[Surgical aortic fenestration in acute thoracoabdominal aortic dissection with abdominal malperfusion and end organ ischemia].

Intestinal, renal, spinal or peripheral arterial ischemia or failure of branch artery recanalization following initial prosthetic repair of thoracoabdominal aortic dissection is still a problem, with high morbidity and mortality. Five consecutive patients with acute thoracoabdominal aortic dissection (two type A dissections, three type B dissections) suffering from concomitant intestinal, renal, spinal and acute peripheral arterial ischemia are reported. Considering the anatomical and pathophysiological basis of thoracoabdominal aortic dissection and concomitant organ ischemia, the aortic fenestration procedure as a primary or secondary operative approach succeeded in restoring blood flow in all cases without complications. Assessment of the long-term results after 3 years revealed that all patients are doing well without any residual complaints. We conclude that in the case of persistent or secondary onset of aortic branch artery ischemia following initial prosthetic repair of either type A or type B dissection, aortic fenestration can be recommended immediately as a staged operative approach. Primary abdominal aortic fenestration is justified in acute type B dissection when end-organ ischemia becomes the focus of clinical deterioration.

Acute Disease↗

Basilar artery fenestration in association with aneurysms of the posterior cerebral circulation.

We reviewed all patients over a 3-year period with documented aneurysms of the posterior cerebral circulation, and re-examined the angiograms of 103 patients. There were 9 cases of fenestration of the basilar artery, all associated with aneurysms of the basilar artery. In 6, the aneurysm arose at the site of the fenestration. We believe that the presence of a fenestration predisposes to aneurysm formation, due to the combination of the resulting alteration in flow characteristics and the presence of a defect in the media of the vessel.

Adult↗

The MRI appearance of the optic nerve sheath following fenestration for benign intracranial hypertension.

Optic nerve fenestration is carried out in cases of severe benign intracranial hypertension. This study aimed to monitor the optic nerve sheath appearances and orbital changes that occur following this procedure. The eight patients were all female with an average age of 37.3 years and a range of 20-58 years. The duration of symptoms was 2-6 years. Symptoms included headaches, diplopia and visual obscurations. Examination revealed severe papilledema. All investigations, including MRI, biochemical and immunological tests, were negative. Patients had fenestration of a 2 mm x 3 mm segment of the medial aspect of the optic nerve sheath. Imaging was obtained with a 1 T MRI machine using a head coil. Coronal, axial and sagittal 3 mm contiguous sections using STIR sequences with TR 4900 ms, IT 150 ms and TE 60 ms were obtained. Five patients showed clinical improvement. The post-operative MRI findings in four of these included a decreased volume of cerebrospinal fluid (CSF) around the optic nerve sheaths and a localized collection of fluid within the orbit. There were no MRI changes in the three patients with no clinical improvement. Decreased CSF volume around the optic nerve and a fluid collection within the orbit may indicate a favorable outcome in optic nerve fenestration.

Adult↗

Capillary changes with fenestrations in the contralateral soleus muscle of the rat following unilateral limb immobilization.

Using electron microscopy, we examined structural changes in the capillaries of the immobilized and contralateral soleus muscles in the rat after the unilateral limb had been immobilized for 4 weeks. Individual contralateral muscle fibers showed a normal structure, compared with the structure in the immobilized muscle fibers. Most capillaries in the contralateral muscle were of the continuous type. However, about 5% of the examined capillaries in these muscles in each rat had fenestrations. The non-nuclear portions of the endothelial cells in these capillaries were extremely thin and were perforated by several fenestrations that were bridged by a single-layered diaphragm. The fenestration of capillaries in the contralateral muscle may have been caused by some the unilateral limb immobilization.

Animals↗

Endovascular treatment of basilar trunk aneurysm associated with fenestration of the basilar artery.

Basilar trunk saccular aneurysms associated with fenestration are infrequent, especially in the middle or distal portion of the basilar artery. Surgical treatment of the basilar trunk aneurysm is difficult, due to its anatomical environment and the complicated surgical exposure. A 46-year-old woman presenting with Hunt and Kosnik grade II subarachnoid hemorrhage was found to have a ruptured aneurysm arising at the proximal corner of the associated fenestration in the middle portion of the basilar artery. Because of surgical difficulties anticipated in approaching the aneurysm, it was decided to treat it with endovascular embolization utilizing the Guglielmi detachable coil; and complete occlusion of the aneurysm was obtained. The efficacy of endovascular treatment for the basilar trunk aneurysm with associated fenestration is discussed from anatomical and embryological points of view, and relevant literature is reviewed.

Basilar Artery↗

Percutaneous balloon fenestration and stent placement for lower limb ischemia complicated with type B aortic dissection.

We report a case of lower limb ischemia secondary to type B aortic dissection, which was successfully treated with endovascular aortic fenestration and stent placement. In this case, we were not able to restore adequate flow to the ischemic limb by means of aortic balloon fenestration alone, so additional stent placement was required to buttress the true lumen and fenestra. There was no recurrence of lower limb ischemia complications during the follow-up period. Aortic balloon fenestration with stent placement seems to be a safe and effective technique to salvage an ischemic lower limb complicated by acute aortic dissection.

Aortic Dissection↗

Fenestrated duodenal membranes: an analysis of symptoms, signs, diagnosis, and treatment.

Duodenal obstruction typically occurs in the ampullary region and presents in the early neonatal period. If the obstruction is incomplete, as with a fenestrated duodenal membrane, the presentation may be delayed and the diagnosis overlooked. Sixteen patients with fenestrated duodenal membranes presented over a 23-year period. Six presented in the neonatal period, with vomiting; an abdominal x-ray was diagnostic in four. Ten presented later (5 weeks to 14 years) with nonspecific symptoms, ie, failure to thrive, postprandial epigastric distension, and recurrent chest infections. Vomiting occurred in all, but was of short duration (< 1 week). Two patients in the delayed group had Down's syndrome. Diagnosis was confirmed on barium meal, and optimal surgical treatment was a bypass duodeno-duodenostomy. The diagnosis of fenestrated duodenal membrane must be considered in all cases with symptoms and signs suggestive of upper gastrointestinal tract obstruction, and excluded by contrast radiology.

Adolescent↗

Multiple aneurysms of the vertebrobasilar system associated with fenestration of the vertebral artery.

A rare case of multiple aneurysms of the vertebrobasilar system associated with fenestration of the intracranial vertebral artery is reported. A search of the world literature revealed 56 other cases of the vertebral artery fenestration, mainly in reports from Japan. Only 11 cases of this association with intracranial aneurysms were reported, and none of these aneurysms were located on the posterior circulation. Association of multiple vertebrobasilar aneurysms and vertebral artery fenestration is rare.

Basilar Artery↗

Laparoscopic fenestration for the treatment of patients with severe adult polycystic liver disease.

BACKGROUND: The purpose of this study was to present our experience in laparoscopic fenestration for patients with severe symptomatic adult polycystic liver disease (APLD), analyze its feasibility, and evaluate its immediate and mid-term outcome. METHODS: Between January 2000 and January 2002, 9 patients underwent laparoscopic fenestration for symptomatic APLD in our laparoendoscopic unit. All patients had both liver lobes affected with multiple cysts, whereas type II disease (present in 8 patients) was not a contraindication for the procedure. The results were retrospectively evaluated. RESULTS: Conversion to laparotomy was required in 1 patient who was submitted to a second laparoscopic procedure (2 years postoperatively) after being admitted to our department with sepsis. Complete regression of symptoms was achieved in 7 of our patients (77.8%). One death occurred because of acute renal failure established 5 weeks after the patient was discharged. During a mean follow-up of 25.8 months, 2 patients presented with recurrence of their symptoms (22.2%). One of them was reoperated on; both of them remain symptom free 14 months postoperatively. CONCLUSIONS: Laparoscopic fenestration appears to be a useful and effective approach for severe APLD. It is associated with short hospital stay and a significant symptom-free period. Despite the reported morbidity, aggressive and meticulous deroofing of as many cysts as possible can be successfully applied for carefully selected patients with type II disease.

Adult↗

Navigator system-assisted endoscopic fenestration of a symptomatic cyst in the septum pellucidum--technique and cases report.

Expanding cysts of the septum pellucidum are rare and frequently manifest as intermittent headaches. Although the technique of endoscopic fenestration has been used since 1999, only a limited number of cases have been reported. We have added the use of a navigator system to guide keyhole creation and endoscopic access. To provide experience in navigator endoscopic treatment of symptomatic cyst of septum pellucidum and long-term follow-up of the surgical result. Under the guidance of the navigator system, a burr hole was made and rigid endoscope was inserted into the lateral ventricle through a working sheath. With direct visualization, only one side of the lateral wall of the cyst was fenestrated. And a grasping basket was used to further dilate the perforated hole. Patient A, a 14-year-old male adolescent, had an acute onset of severe headache with increased intracranial pressure. Patient B was a 37-year-old woman with a diagnosis of medically intractable migraine. Both patients experienced dramatic symptomatic relief after surgery at 4.5- and 2-year follow-up exams, respectively. The technique of navigator-assisted endoscopic fenestration in the treatment of a symptomatic cyst of the septum pellucidum might be a safe and effective method. It achieved satisfactory results in our two patients.

Adolescent↗

Fenestrated and branched stent-grafting after previous surgery provides a good alternative to open redo surgery.

OBJECTIVE: To present our experience using fenestrated and branched endoluminal grafts for Para-anastomotic aneurysms (PAA) following prior open aneurysm surgery, and after previous endovascular aneurysm repair (EVAR) complicated by proximal type I endoleak. METHODS: Fenestrated and/or branched EVAR was performed on eleven patients. Indications included proximal type I endoleak after EVAR and short infrarenal neck (n=4), suprarenal aneurysm after open AAA (n=4), distal type I endoleak after endovascular TAA (n=1), proximal anastomotic aneurysm after open AAA (n=1), and an aborted open AAA repair due to bleeding around a short infrarenal neck. RESULTS: The operative target vessel success rate was 100% (28/28) with aneurysm exclusion in all patients. Mean hospital stay was 6.0 days (range 2-12 days, SD 3.5 days). Thirty day mortality was 0%. All cause mortality during 18 months mean follow-up (range 5-44 months, SD 16.7 months) was 18% (2/11) with no deaths from aneurysm rupture. Cumulative visceral branch patency was 96% (27/28) at 42 months. Average renal function remained unchanged during the follow-up period. CONCLUSIONS: Our report highlights the potential of fenestrated and branched technology to improve re-operative aortic surgical outcomes. The unique difficulties of increased graft on graft friction hindering placement, short working distance, and increased patient co-morbidities should be recognized.

Angioplasty↗

Laparoscopic fenestration of posttransplant lymphoceles in children.

BACKGROUND/PURPOSE: Lymphoceles are frequently observed as a surgical complication after renal transplantation. Whereas the frequency, pathogenesis, diagnosis, and treatment of lymphoceles has been well described in adult patients, no data are available for the pediatric age group. METHODS: Since December 2000; 5 children (2 boys and 3 girls; median age, 6 years; range, 6 to 15 years) of a total of 21 (10 boys and 11 girls; median age, 13 years; range, 2 to 19 years) children undergoing kidney transplantation had a posttransplant lymphocele. The clinical course, renal function, and ultrasonographic appearance of the transplanted kidney of all children were observed in a prospective manner. RESULTS: The lymphoceles became obvious between day 13 and 48 (median, 20 days) posttransplantation. Lymphocele size ranged from 2.0 x 3.0 cm to 11.0 x 15.0 cm. They were localized at any site (superior, inferior, lateral, medial, and dorsal) around the transplanted kidney. Four patients had a significant decrease of renal function, in 2 children mild urinary tract obstruction occurred, and 1 patient suffered from considerable abdominal pain. Diagnosis was established by ultrasound scan in all cases. All patients were treated by laparoscopic fenestration of the lymphocele immediately after diagnosis, except 1 patient, in whom fenestration was not done until 10 months later. Operating time ranged from 45 to 90 minutes (median, 62 minutes). No intraoperative or postoperative complication occurred. Renal function, urinary tract obstruction, and pain recovered soon after operation in all patients. After 3 to 10 months (median, 8 months) postoperatively, no relapse has been observed. CONCLUSIONS: Our data emphasize laparoscopic fenestration as the treatment of choice for children with posttransplant lymphoceles, because it is safe, effective, and technically easy to perform. If done early after diagnosis, renal function will recover immediately.

Adolescent↗

Fenestrated endovascular grafting: The renal side of the story.

BACKGROUND: Fenestrated endovascular aneurysm repair uses the visceral aortic segment, in the setting of a suboptimal proximal neck, for sealing and fixation. This technique requires the placement of visceral stents and might be hampered by the deleterious effects of such interventions. This study was performed to define outcomes related to renal events. MATERIALS AND METHODS: Consecutive clinical records and radiographic studies of patients treated primarily with an endovascular approach with a fenestrated endograft were reviewed. The population was divided into groups with and without baseline renal dysfunction based on the National Kidney Foundation definition of chronic kidney disease. Morphologic measurements and the detection of postoperative renal events such as renal artery stenosis or occlusion, need for dialysis, deterioration of renal function by using estimated glomerular filtration rate (GFR), and secondary interventions related to the renal arteries were assessed. Preoperative and postprocedural factors predictive for the development of renal dysfunction were assessed by using a Fisher exact test, t test, and logistic regression. RESULTS: A total of 72 patients were treated between 2001 and 2004 with a mean age, aneurysm size, and follow-up of 75 years, 6.2 cm, and 6 months (range, 1 to 24 months), respectively. No ruptures and five deaths (two procedure-related) were observed. There were 23 patients with baseline renal insufficiency and 49 patients without insufficiency. Twenty-four patients had deterioration in GFR >30% during the follow-up period, and 17 patients experienced 19 renal-related events (more common in patients with baseline insufficiency, 39% vs 16.3%; P = .04; relative risk, 2.4). Four patients required dialysis (two permanent), and all had preoperative renal dysfunction ( P = .002); similarly, death was also more common in this group (17.4% vs 2%; P = .02; relative risk, 8.52). Renal events in most patients occurred within the first postoperative month (59%). However, mean GFR stabilized after 6 months. CONCLUSION: Aneurysm repair with fenestrated endovascular grafts is associated with a significant risk for adverse renal events (16% in those without renal dysfunction, although none developed a creatinine >2 mg/dL, and 39% for patients with preoperative renal dysfunction). These patients must be meticulously followed, particularly within the first month after such a procedure. When renal artery restenosis is suspected or diagnosed, aggressive approach might be warranted to limit the extent of late renal dysfunction.

Aged↗