ERCP Using Double-Balloon Enteroscopy in Patients with Roux-en-Y Anatomy

Double-balloon enteroscopy (DBE) is a useful method for endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y anatomy. Depending on the distorted anatomy, endoscopic therapies with conventional scopes were very difficult or impossible before the advent of DBE and patients had to be submitted to a percutaneous or surgical approach. The case of 6 patients with different types of Roux-en-Y-altered anatomy in which DBE-ERCP was performed with 83.3% successful rate (5/6) is reported confirming recent data in the literature on the feasibility of this method. Copyright (C) 2009 S. Karger AG, Basel

Endoscopic Anatomy of the Pterygopalatine Fossa and the Transpterygoid Approach: Development of a Surgical Instruction Model

Introduction: The pterygopalatine fossa (PPF) is a narrow space located between the posterior wall of the antrum and the pterygoid plates. Surgical access to the PPF is difficult because of its protected position and its complex neurovascular anatomy. Endonasal approaches using rod lens endoscopes, however, provide better visualization of this area and are associated with less morbidity than external approaches. Our aim was to develop a simple anatomical model using cadaveric specimens injected with intravascular colored silicone to demonstrate the endoscopic anatomy of the PPF. This model could be used for surgical instruction of the transpterygoid approach. Methods: We dissected six PPF in three cadaveric specimens prepared with intravascular injection of colored material using two different injection techniques. An endoscopic endonasal approach, including a wide nasoantral window and removal of the posterior antrum wall, provided access to the PPF. Results: We produced our best anatomical model injecting colored silicone via the common carotid artery. We found that, using an endoscopic approach, a retrograde dissection of the sphenopalatine artery helped to identify the internal maxillary artery (IMA) and its branches. Neural structures were identified deeper to the vascular elements. Notable anatomical landmarks for the endoscopic surgeon are the vidian nerve and its canal that leads to the petrous portion of the internal carotid artery (ICA), and the foramen rotundum, and V2 that leads to Meckel`s cave in the middle cranial fossa. These two nerves, vidian and V2, are separated by a pyramidal shaped bone and its apex marks the ICA. Conclusion: Our anatomical model provides the means to learn the endoscopic anatomy of the PPF and may be used for the simulation of surgical techniques. An endoscopic endonasal approach provides adequate exposure to all anatomical structures within the PPF. These structures may be used as landmarks to identify and control deeper neurovascular structures. The significance is that an anatomical model facilitates learning the surgical anatomy and the acquisition of surgical skills. A dissection superficial to the vascular structures preserves the neural elements. These nerves and their bony foramina, such as the vidian nerve and V2, are critical anatomical landmarks to identify and control the ICA at the skull base.

Rabbit Retinal Neovascularization Induced by Latex Angiogenic-Derived Fraction: An Experimental Model

Purpose: To create a retinal neovascularization experimental model using intravitreal injection of microspheres loaded with latex-derived angiogenic fraction. Methods: Thirty-two albino New Zealand rabbits, divided in 4 groups of 8 animals, were enrolled in this study. Rabbits in groups I, II, and III received one intravitreal injection of PLGA (L-lactide-co-glycolide) microspheres with 10, 30, and 50 mu g of latex-derived angiogenic fraction into their right eyes, respectively, and group IV received 0.1 ml of microspheres without the angiogenic fraction. Weekly follow-up with ophthalmoscopy and fluorescein angiography was performed; the rabbits were sacrificed in the 4th week and their eyes processed for light microscopy. Results: All eyes from group I demonstrated increased retinal vascular tortuosity, observed from 14 days after injection and maintained for 28 days, otherwise without new vessels detection. All group II eyes showed vascular changes similar to group I. Fifty percent of the eyes from group II rabbits developed retinal neovascularization 21 days after injection. All eyes from group III demonstrated significant vascular tortuosity and retinal new vessels 2 weeks after injection, progressing to fibrovascular proliferation and tractional retinal detachment. No vascular changes or retinal new vessels were observed in group IV eyes. Light microscopy confirmed the existence of new vessels previously seen on fluorescein angiography, in retinal sections adjacent to the optic disc, not observed in sections at the same area in the control group. Conclusion: Thirty- and 50-mu g microspheres containing latex-derived angiogenic fraction injected into the vitreous cavity induced retinal neovascularization in rabbits.

Intraoperative bleeding during vitrectomy for diabetic tractional retinal detachment with versus without preoperative intravitreal bevacizumab (IBeTra study)

Aims: To compare the amount of intraoperative intraocular bleeding in patients with diabetes with macula-involving tractional retinal detachment (TRD) undergoing pars plana vitrectomy (PPV) with and without preoperative intravitreal bevacizumab (IVB) injection. Methods: An institutional study was carried out with consecutive patients with diabetic retinopathy and macula-involving TRD of recent (3 months) onset who were randomly assigned to PPV only (PPV group) or PPV combined with one IVB (1.5 mg/0.06 ml) injection 2 weeks prior to surgery (bevacizumab (BEV)/PPV group). All patients underwent 23-gauge PPV 3 weeks after baseline. The main outcome measure was erythrocyte count in the fluid retrieved from the vitrectomy cassette using a Neubauer counting chamber. Results: The study included 20 patients. The mean erythrocyte count was 14865x10(3) (SD 19332x10(3); median 4500x10(3)) cells in the BEV/PPV group, and 176240x10(3) (SD 108375x10(3); median 166600x10(3)) cells in the PPV group. The mean erythrocyte count was significantly lower in the BEV/PPV group than in the PPV group (p < 0.0001). No major adverse events were identified. Conclusion: Preoperative IVB injection was associated with reduced intraocular bleeding during 23-gauge PPV for diabetic macula-involving TRD. Further studies are needed to confirm our preliminary findings.

INTRAVITREAL INJECTION OF AUTOLOGOUS BONE MARROW-DERIVED MONONUCLEAR CELLS FOR HEREDITARY RETINAL DYSTROPHY A Phase I Trial

Purpose: To evaluate the short-term (10 months) safety of a single intravitreal injection of autologous bone marrow-derived mononuclear cells in patients with retinitis pigmentosa or cone-rod dystrophy. Methods: A prospective, Phase I, nonrandomized, open-label study including 3 patients with retinitis pigmentosa and 2 patients with cone-rod dystrophy and an Early Treatment Diabetic Retinopathy Study best-corrected visual acuity of 20/200 or worse. Evaluations including best-corrected visual acuity, full-field electroretinography, kinetic visual field (Goldman), fluorescein and indocyanine green angiography, and optical coherence tomography were performed at baseline and 1, 7, 13, 18, 22, and 40 weeks after intravitreal injection of 10 X 10(6) autologous bone marrow-derived mononuclear cells (0.1 mL) into 1 study eye of each patient. Results: No adverse event associated with the injection was observed. A 1-line improvement in best-corrected visual acuity was measured in 4 patients 1 week after injection and was maintained throughout follow-up. Three patients showed undetectable electroretinography responses at all study visits, while 1 patient demonstrated residual responses for dark-adapted standard flash stimulus (a wave amplitude approximately 35 mu V), which remained recordable throughout follow-up, and 1 patient showed a small response (a wave amplitude approximately 20 mu V) recordable only at Weeks 7, 13, 22, and 40. Visual fields showed no reduction (with a Goldman Standard V5e stimulus) for any patient at any visit. No other changes were observed on optical coherence tomography or fluorescein and indocyanine green angiograms. Conclusion: Intravitreal injection of autologous bone marrow-derived mononuclear cells in eyes with advanced retinitis pigmentosa or cone-rod dystrophy was associated with no detectable structural or functional toxicity over a period of 10 months. Further studies are required to investigate the role, if any, of autologous bone marrow-derived mononuclear cell therapy in the management of retinal dystrophies. RETINA 31: 1207-1214, 2011

A Simple and Efficient Device for Demonstrating Cross-sectional Anatomy of the Head

Described in this article is a novel device that facilitates study of the cross-sectional anatomy of the human head. In designing our device, we aimed to protect sections of the head from the destructive action of handling during anatomy laboratory while also ensuring excellent visualization of the anatomic structures. We used an electric saw to create 15-mm sections of three cadaver heads in the three traditional anatomic planes and inserted each section into a thin, perforated display box made of transparent acrylic material. The thin display boxes with head sections are kept in anatomical order in a larger transparent acrylic storage box containing formaldehyde solution, which preserves the specimens but also permits direct observation of the structures and their anatomic relationships to each other. This box-within-box design allows students to easily view sections of a head in its anatomical position as well as to examine internal structures by manipulating individual display boxes without altering the integrity of the preparations. This methodology for demonstrating cross-section anatomy allows efficient use of cadaveric material and technician time while also giving learners the best possible handling and visualization of complex anatomic structures. Our approach to teaching cross-sectional anatomy of the head can be applied to any part of human body, and the value of our device design will only increase as more complicated understandings of cross-sectional anatomy are required by advances and proliferation of imaging technology. Anat Sci Educ 3: 141-143, 2010. (C) 2010 American Association of Anatomists.

Macroscopic and microscopic anatomy of the oviduct in the sexually mature rhea (Rhea americana)

The morphological characteristics of the oviduct of 12 sexually mature rheas (Rhea americana) were studied. Only the left oviduct is developed as a long tube with a length of 122 +/- 23.1 cm, and is subdivided into infundibulum (15.2 +/- 4.0 cm), magnum (63.3 +/- 9.4 cm), isthmus (5.6 +/- 3.1 cm), uterus (16.0 +/- 4.2 cm) and vagina (11.5 +/- 1.4 cm). The mucous membrane of the oviduct, as a whole, possesses luminal folds covered by ciliated columnar epithelium with secretory cells. The infundibulum part presents a cranial opening with thin and long fimbriae with few tubular glands in caudal tubular portion. In the magnum, the largest portion of the oviduct, the folds are thicker and are filled with tubular glands. The isthmus is short and presents less bulky folds and a few tubular glands. A bag-shaped uterus in the cranial area shows thin folds, and in the caudal region (shell gland) more ramified folds with few tubular glands. The vagina has long luminal folds and a thick muscular tunic; no glands with sperm-storage characteristics have been observed. In conclusion, the oviduct in sexually mature rhea has morphological similarities with the other species of birds already described; however it presents its own characteristics to produce a big egg.

PRECLINICAL INVESTIGATION OF THE RETINAL BIOCOMPATIBILITY OF SIX NOVEL VITAL DYES FOR CHROMOVITRECTOMY

Purpose: To investigate the retinal biocompatibility of six novel vital dyes for chromovitrectomy. Methods: An amount of 0.05 mL of 0.5% and 0.05% light green (LG), fast green (FG), Evans blue (EB), brilliant blue (BriB), bromophenol blue (BroB), or indigo carmine (IC) was injected intravitreally in the right eye, whereas in the left eye balanced salt solution was applied for control in rabbits` eyes. Clinical examination, fluorescein angiography, histology with light microscopy, and transmission electron microscopy were performed after 1 and 7 days. Retinal cell layers were evaluated for morphologic alterations and number of cells. The electroretinographic changes were assessed at baseline, 24 hours and 7 days. Results: Fluorescein angiography disclosed hypofluorescent spots only in the 0.5% EB group. Light microscopy and transmission electron microscopy disclosed slight focal morphologic changes in eyes exposed to 0.05% IC, FG, BriB, similar to the control at 1 and 7 days. In the lower dose groups, EB, LG, and BroB caused substantial retinal alterations by light microscopy. At the higher dose, BroB and EB produced diffuse cellular edema and vacuolization within the ganglion cells, bipolar cells, and photoreceptors. FG and IC at 0.5% caused slight retinal alterations similar to balanced salt solution injection. LG at 0.5% caused diffuse vacuolization of bipolar cells after 1 and 7 days. Injection of 0.5% EB caused a significant decrease in neuroretinal cell counts in comparison to control eyes in the 7-day examination (P < 0.05). Electroretinography revealed intermittent prolonged latency and decreased amplitude in eyes injected with 0.5% EB, LG, BriB, and BroB, while at the lower dose, only LG and EB induced few functional changes. Conclusion: The progressive order of retinal biocompatibility, from safest to most toxic, was IC, FG, BriB, BroB, LG, EB.

The anatomy of two-rooted mandibular canines determined using micro-computed tomography

P>Aim To investigate the internal and external anatomy of extracted human mandibular canines with two roots and two distinct canals using micro-computed tomography (mu CT). Methodology Fourteen two-rooted human mandibular canines were scanned using a high-resolution mu CT system (SkyScan 1174v2; SkyScan N.V., Kontich, Belgium). The images were processed to evaluate the size of the roots, the furcation regions, the presence of accessory canals, the mean distances between several anatomical landmarks, the position of the apical foramina, the direction of root curvatures, the cross-sectional appearances (SMI index), the volume and surface areas of the root canals. Results Root bifurcation was located in both apical (44%, n = 6) and middle (58%, n = 8) thirds of the root. The size of the buccal and lingual roots was similar in 29% of the sample. From a buccal view, no curvature towards the lingual or buccal direction occurred in either roots. From a proximal view, no straight lingual root occurred. In both views, S-shaped roots were found in 21% of the specimens. Location of the apical foramen varied considerably, tending to the mesio-buccal aspect of both roots. Lateral and furcation canals were observed mostly in the cervical third in 29% and 65% of the sample, respectively. The structure model index (SMI) index ranged from 1.87 to 3.86, with a mean value of 2.93 +/- 0.46. Mean volume and area of the root canals were 11.52 +/- 3.44 mm3 and 71.16 +/- 11.83 mm2, respectively. Conclusions The evaluation of two-rooted mandibular canines revealed that bifurcations occurred in the apical and middle third. S-shaped roots were found in 21% of the specimens. Mean volume, surface area and SMI index of the root canals were 11.52 mm3, 71.16 mm2 and 2.93, respectively.

Differential perturbation of neuronal and glial glutamate transport systems in retinal ischaemia

Glutamate is the major excitatory neurotransmitter in the retina and is removed from the extracellular space by an energy-dependent process involving neuronal and glial cell transporters. The radial glial Muller cells express the glutamate transporter, GLAST, and preferentially accumulate glutamate. However, during an ischaemic episode, extracellular glutamate concentrations may rise to excitotoxic levels. Is this catastrophic rise in extracellular glutamate due to a failure of GLAST? Using immunocytochemistry, we monitored the transport of the glutamate transporter substrate, D-aspartate, in the retina under normal and ischaemic conditions. Two models of compromised retinal perfusion were compared: (1) Anaesthetised rats had their carotid arteries occluded for 7 days to produce a chronic reduction in retinal blood flow. Retinal function was assessed by electroretinography. D-aspartate was injected into the eye for 45 min, Following euthanasia, the retina was processed for D-aspartate. GLAST and glutamate immunocytochemistry. Although reduced retinal perfusion suppresses the electroretinogram b-wave, neither retinal histology, GLAST expression, nor the ability of Muller cells to uptake D-aspartate is affected. As this insult does not appear to cause excitotoxic neuronal damage, these data suggest that GLAST function and glutamate clearance are maintained during periods of reduced retinal perfusion. (2) Occlusion of the central retinal artery for 60 min abolishes retinal perfusion, inducing histological damage and electroretinogram suppression. Although GLAST expression appears to be normal. its ability to transport D-aspartate into Muller cells is greatly reduced. Interestingly, D-aspartate is transported into neuronal cells, i.e. photoreceptors, bipolar and ganglion cells. This suggests that while GLAST is vitally important for the clearance of excess extracellular glutamate, its capability to sustain inward transport is particularly susceptible to an acute ischaemic attack. Manipulation of GLAST function could alleviate the degeneration and blindness that result from ischaemic retinal disease. (C) 2001 Elsevier Science Ltd, All rights reserved.