Posterior Membrane Research Articles

Successful resection of a glomus tumor of the trachea

Extracutaneous glomus tumors are uncommon, and their occurrence in the trachea is rare. We present a case of a surgically resected glomus tumor of the trachea in a 56-year-old woman who presented with worsening dyspnea and cough. Bronchoscopy and computed tomography showed a polypoid tumor arising from the posterior membrane of the lower trachea just above the carina; the tracheal lumen was approximately 80% occluded. The patient underwent successful tracheal sleeve resection with primary reconstruction. The histological characteristics and immunohistochemical profile were typical for this tumor. The clinicopathological features of this unusual neoplasm are discussed, and the literature is reviewed.

Misleading axial length measurements with the IOLMaster due to a dense posterior vitreous surface membrane and a macular edema in a diabetic patient

Misleading axial length measurements with the IOLMaster due to a dense posterior vitreous surface membrane and a macular edema in a diabetic patient

Evaluation des Dresdner Tympanoplastik Modells (DTM)

The training of microsurgical motor skills is essentiell for surgical education if the interests of the patient are to be safeguarded. In otosurgery the complex anatomy of the temporal bone and variations necessitate a special training before performing surgery on a patient. We therefore developed and evaluated a simplified middle ear model for acquiring first microsurgical skills in tympanoplasty.The simplified tympanoplasty model consists of the outer ear canal and a tympanic cavity. A stapes model is placed in projection of the upper posterior tympanic membrane quadrant at the medial wall of the simulated tympanic cavity. To imitate the annular ligament flexibility the stapes is fixed on a soft plastic pad. 41 subjects evaluated the model´s anatomical analogy, the comparability to the real surgical situation and the general model properties the using a special questionnaire.The tympanoplasty model was very well evaluated by all participants. It is a reasonably priced model and a useful tool in microsurgical skills training. Thereby, it closes the gap between theoretical training and real operation conditions.

Spontaneous Corneal Clearing after Descemet's Stripping without Endothelial Replacement

To report spontaneous corneal clearing with improved visual acuity and central endothelial cell repopulation after Descemet's stripping without endothelial replacement. Interventional case report. A 34-year-old woman with bilateral decreased vision secondary to corneal edema from endothelial dysfunction underwent Descemet's stripping endothelial keratoplasty (DSEK) in the right eye and Descemet's stripping only in the left eye. Histopathologic evaluation confirmed a dual diagnosis of Fuchs' endothelial dystrophy and posterior polymorphous membrane dystrophy from Descemet's membrane specimens removed from each eye. After primary graft failure with regraft in the right eye, the second posterior corneal lenticule detached and was removed and not replaced. The cornea cleared, and central endothelial cell repopulation was documented by confocal microscopy. Therefore, Descemet's stripping without endothelial replacement was performed in the left eye. The left cornea also cleared with central endothelial cell repopulation. Postoperative visual acuity and central endothelial cell repopulation. Endothelial migration after Descemet's stripping alone in the left eye, with probable host endothelial cell repopulation in the right eye. Endothelial cell migration after Descemet's stripping procedure without insertion of endothelial graft can occur, resulting from host endothelial cell repopulation with corneal clearing and improved visual acuity.

Histopathology of Behçet’s uveitis

AbstractPurpose To report the histological findings in an eye with severe Behçet’s disease.Methods A 17‐year‐old male had a longstanding history of chronic intraocular inflammation, which was treated with high dose steroids, immunosuppression and biological agents (anti‐TNF therapy). Despite this aggressive treatment, he suffered persistent uveitis, and had also undergone cataract and pars plana vitrectomy with silicone oil tamponade. Eventually the patient underwent enucleation of his left eye, which had become blind and painful. The specimen was sent to the Pathology Dept. RLBUHT, for morphological examination.Results Histological sections of the enucleated eye demonstrated extensive pathological changes. These included: chronic keratitis with associated neovascularisation; severe chronic granulomatous iridocyclitis with the development of anterior synechiae with angle closure, as well as extensive posterior cyclitic membrane formation with ciliary process destruction. The inflammation, which was characterised by dense lymphocytic and plasma cell infiltrates, extended posteriorly into the choroid, focally involving the retina. Chronic vasculitis resulted in a typical “onion‐skinning” appearance of some blood vessels. There was optic disc cupping. Immunohistochemistry was performed to characterise the lymphocytic and plasma cell populations.Conclusion This case is a rare example of end‐stage Behçet’s disease in which the histopathological alterations will be demonstrated.

Reinvestigation of the ambient cistern and its related arachnoid membranes: an anatomical study

A precise understanding of the ambient cistern and its associated arachnoid membranes is helpful for accessing perimesencephalic lesions. However, few studies of the arachnoid membranes related to the ambient cistern have been published, and, additionally, some aspects of the ambient cistern also require further examination. The goal of this study was to reinvestigate and expound on the anatomical features of the cistern and membranes. The ambient cisterns and its associated arachnoid membranes were examined in 20 adult cadaveric brains using an operative microscope. The perimesencephalic membrane is a set of inner arachnoid membranes surrounding the midbrain at the level of the tentorial incisura. It arises from the outer arachnoidal membranes covering the tentorial edge and the dorsum sellae and can be subdivided into anterior and posterior portions. The anterior membrane is actually the mesencephalic leaf of Liliequist membrane, which is divided into medial and lateral parts by the oculomotor nerve. The posterior membrane can be divided into horizontal and ascending parts. The ambient cistern is located above the perimesencephalic membrane and contains the anterior choroidal arteries, the posterior cerebral arteries, the basal vein, and sometimes the segments of the superior cerebellar arteries. It communicates with the carotid cistern, the interpeduncular cistern, the oculomotor cistern, the cerebellopontine and cerebellomesencephalic cistern, and the quadrigeminal cistern. This study updates some information about the ambient cistern and its arachnoid membranes. The perimesencephalic membrane was identified and described in detail. The ambient cistern was verified to be a supratentorial cistern above the perimesencephalic membrane. The borders and contents of this cistern, as well as its relationship with adjacent cisterns, were also redefined.

Ichthyosis follicularis, alopecia and photophobia syndrome (IFAP): report of the first case with ocular and cutaneous manifestations in Brazil with a favorable response to treatment

Ichthyosis follicular, alopecia, and photophobia (IFAP) syndrome is a rare disease, with possible X-linked mode of inheritance. The patient presented with ocular findings of photophobia, corneal scarring and erosions, superficial and deep corneal vascularization and myopia. He was treated with artificial tears and punctal occlusion with small improvement of photophobia. After three months using systemic retinoid (Acitretina) and posterior amniotic membrane transplantation in the left eye, there was a significant improvement of photophobia, corneal erosions and neuropsychomotor development.

Descemet-stripping Automated Endothelial Keratoplasty—A Review

Descemet-stripping automated endothelial keratoplasty (DSAEK) has become the procedure of choice to treat corneal endothelial dysfunction. The technique involves replacing the diseased host endothelium with a graft consisting of a thin layer of posterior stroma, Descemet membrane, and endothelium. In comparison to penetrating keratoplasty (PK), DSAEK confers quicker visual and structural recovery with absence of corneal surface incisions or sutures, and limits astigmatism. DSAEK has been proved to successfully achieve favorable visual acuity and graft clarity in bullous keratopathy, posterior polymorphous dystrophy, and failed PK grafts. This article discusses various DSAEK surgical techniques, short- and longterm post-surgical results, complications, and comparisons with other types of keratoplasty. With the advent of Descemet membrane endothelial keratoplasty (DMEK), in which only Descemet membrane is transplanted, visual rehabilitation may be attained sooner.

Influence of intravitreous silicone oil on refractive state of eye and its relevant factors

目的 评估有晶状体或无晶状体囊膜是否保留的不同状态下硅油填充对眼屈光状态的影响,进一步探讨可能影响硅油填充眼屈光度改变的相关因素.方法 将行玻璃体硅油填充并拟行硅油取出的69眼依据晶状体的情况分为有晶状体眼组(n=34)、无晶状体囊膜保留完整组(n=22)和无晶状体无囊膜组(n=13).硅油取出前后行屈光度、视力、眼压、B型超声和超声生物显微镜(UBM)检查.采用多元回归法分析硅油取出前后术眼的屈光度差值与患者年龄、性别、眼别、术前屈光度、硅油填充时间和眼压的相关性.结果 有晶状体组、无晶状体囊膜(前或后)保留完整组及无晶状体无囊膜组硅油取出后屈光度的改变量分别为(-9.23±2.82)、(+1.09±2.50)、(+5.47±2.97)D,3组间屈光差值的差异有统计学意义(F=160.89,P=0.000).在有晶状体组中,硅油取出术后屈光度的改变量与年龄(r=-0.140,P=1.000)、性别(r=-0.164,P=0.982)、眼别(r=-0.008,P=0.981)、硅油填充时间(r=-289,P=0.997)和眼压(r=-0.038,P=1.000)间均无明显相关,但与硅油填充前屈光度呈负相关(r=-0.558,P=0.000).B型超声检查显示,坐位时硅油泡完全与后极部视网膜贴伏.UBM检查显示,在有晶状体眼及无晶状体眼中囊膜后均有玻璃体残留.结论 在晶状体、囊膜的不同状态下硅油取出术后的屈光度改变量各不相同.在有晶状体眼中,屈光度改变与硅油填充前术眼的屈光度有关.囊膜后玻璃体残留、囊膜的自身状态影响了硅油泡前表面的形态,导致个体差异性的产生。

Interfascial Technique for Vertebral Artery Exposure in the Suboccipital Triangle: The Road Map

The extradural portion of the vertebral artery (VA-V3) has a unique anatomy at the craniovertebral junction. The exposure of V3 can be accompanied by profuse bleeding from the venous plexus in addition to the potential risk of inadvertent injury of the VA during surgery at the craniovertebral junction. The natural tissue planes represent a road map to the safe exposure of the VA in the suboccipital triangle. To describe the microsurgical anatomy of the tissue planes in the suboccipital region. The suboccipital region was bilaterally dissected in 6 fresh silicone-injected cadaver heads. An interfascial technique was used to expose the VA-V3 following a tissue plane between the deep suboccipital muscular fascia dorsally and posterior atlantooccipital membrane, the C1 periosteal membrane, and the membrane covering the VA and venous plexus ventrally. The craniovertebral junction was harvested from 2 heads and prepared for histological sections. The same technique was applied in 25 operative cases. The anatomic dissections confirmed the existence of an interfascial plane that can be dissected in a blunt fashion to reach as far lateral as the transverse processes of C1 and C2. Application of the dissection technique did not require diathermy coagulation in the operating room. In 25 cases, there was no injury of the VA or bleeding from the venous plexus. Vertebral artery exposure in the suboccipital triangle (V3) can be achieved safely with minimal blood loss using a technique that follows the natural tissue plane between the deep suboccipital muscle fascia, the posterior atlantooccipital membrane, the membrane covering VA/venous plexus, and the periosteum of the C1 and C2 laminae.

S56 Flat Trachea Syndrome: an under-diagnosed and under-treated condition?

ObjectivesFlat Trachea Syndrome (Tracheobronchomalacia) is a central airway disease characterised by weakness of the wall and dynamic decrease in the tracheal lumen and the large bronchi, particularly while exhaling. It...

In Vitro Evaluation of Endotracheal Tubes With Intrinsic Suction

Endotracheal tube (ETT) intubation impairs mucus clearance, which can lead to respiratory compromise. We compared three ETTs that have intrinsic capacity to aspirate secretions pooling above the cuff. We evaluated the ability of three ETTs with suction, Hi-Lo Evac, Teleflex ISIS, and Portex Blue Line SACETT, to aspirate saliva and mucus simulants at continuous or intermittent vacuum pressures. We also evaluated the potential for a flexible tracheal membrane to obstruct the ETT suction port with applied vacuum. We measured the dimensions of the suction tubing at critical points to calculate differences in flow. In a rigid tracheal model, the ISIS aspirated saliva simulant more quickly with continuous low pressure suction than Evac (P = .0006) and SACETT (P < .0001) as well as with intermittent high pressure suction (P < .0001). For mucus simulant, the ISIS aspirated stimulant better than the other ETTs at high intermittent suction (P < .0001); the Evac was more effective than the SACETT (P = .0019). For low and continuous suction, suction ports in all ETTs occluded with mucus, except for ISIS, at the highest continuous suction tested. In a trachea model with a flexible posterior membrane, this membrane either partially or completely occluded the suction port of all tubes at high continuous or intermittent suction. The ISIS was more prone to obstruction by the flexible membrane than the Evac. We found large differences in suction tubing cross-sectional area between the ISIS and the other tubes, and flow calculations using the Hagen-Poiseuille equation can explain the observed differences in volumes aspirated and tendency toward lumen obstruction. The ISIS transmits suction pressure to the tube orifice more powerfully than the Evac and SACETT. This feature makes the ISIS less prone to obstruction by mucus but more likely to obstruct by tissue suction.

Posterior capsule surgery and posterior capsulorhexis

Abstract Purpose To review the available intraoperative maneuvers to reduce the occurrence of posterior capsule opacification (PCO) after cataract surgery, including lens epithelial cell aspiration (LECA), posterior capsular membrane removal (PCMR), and posterior capsulorhexis (PCRX). Methods Review of the literature and of the available techniques to prevent PCO. Case‐control retrospective studies on the efficacy of LECA for PCO prevention and on the safety of PCRX, namely its influence on vitreoretinal complications. Results To reduce PCO, a number of surgical maneuvers have been described, including LECA, PCMR and PCRX, with variable results. In a series of consecutive 1574 eyes of 1147 patients followed‐up a minimum of 3 years, performing a meticulous LECA following phacoemulsification (PE) reduced PCO occurrence from 36.6% to 17.2% (p&gt;0.01). In another series of consecutive 2.441 eyes operated of PE with or without PCRX, the rate of retinal detachment and cystoid macula edema was nonsignificantly higher after PCRX than cases with an intact capsule (respectively p=0.065 and p=0.32), while comparing favorably to Nd:YAG laser capsulotomy and with unplanned capsule tears. Conclusion Intraoperative capsular techniques such as LECA, PCMR and PCRX may effectively and safely reduce PCO. The variability of the results in the literature may be due to the multiple nonsurgical factors involved (lens design and materials, associated conditions, etc.), as well as minor surgical details indicating that the surgeon factor should not be understated.

Vitreoretinal Surgery for Severe Retinal Capillary Hemangiomas in Von Hippel–Lindau Disease

To evaluate the long-term success rate of vitreoretinal surgery for severe cases of retinal capillary hemangiomas (RCHs) caused by von Hippel-Lindau (VHL) disease. Retrospective case series. Twenty-three eyes of 21 patients with severe exudative or tractional retinal detachment caused by RCH, who had undergone vitreoretinal surgery. Patients' age at initial surgery ranged from 12 to 47 years (median, 27 years), and the fellow eye was already blind in 6 of 21 patients. All eyes underwent pars plana vitrectomy with posterior hyaloid detachment epiretinal membrane dissection and silicone oil or gas injection. In 9 eyes, retinectomy was performed to remove the RCH (group R). In the other 14 eyes, the RCH was treated by laser endophotocoagulation alone or combined with transscleral cryotherapy (group L). Visual acuity (preoperative, 6 and 18 months postoperatively), rate of RCH recurrence, and postoperative complications. In group R, an average of 2 operations per patient was needed. Six months after surgery, the retina was flat in 8 eyes. Mean follow-up was 8 years. Long-term complications included RCH reproliferation and neovascular glaucoma in 4 eyes, 4 to 8 years after initial surgery. In the remaining 5 eyes, visual acuity ranged from 20/320 to counting fingers 18 months postoperatively. In group L, an average of 1.7 operations was needed. Six months after surgery, the retina was flat in 13 of 14 eyes. Mean follow-up was 4 years. New RCH occurred in 10 eyes and required laser treatment. In the long term, 1 eye became blind after 5 years because of aggressive RCH reproliferation and neovascular glaucoma, and 2 eyes became blind after 10 years because of exudative retinal detachment. In the 11 remaining eyes, visual acuity ranged from 20/320 to 20/20 (median: 20/50) 18 months postoperatively. Vitreoretinal surgery is an effective treatment for severe VHL retinal hemangiomas. Large RCHs were satisfactorily treated by (1) vitrectomy with epiretinal dissection and endolaser photocoagulation or (2) retinectomy for RCH resection, although a high rate of vision-threatening RCH recurrence was observed in the long term. However in most cases, surgery improved or prolonged visual function in these eyes.

Anatomic study of the suboccipital artery of Salmon with surgical significance

The anatomy of the muscular branches of the vertebral arteries has clinical relevance during surgical procedures, suboccipital injections, and manual therapies. Each vertebral artery is divided into four segments. Segment V3, found in the suboccipital triangle, courses posteromedially around the lateral mass to lie in a groove on the posterior arch of the atlas, ultimately coursing beneath the posterior atlanto-occipital membrane to enter the skull. Although not always present, any muscular branch that emanates from this segment to supply the suboccipital muscles is called the suboccipital artery of Salmon. There is a paucity of literature on this artery despite its clinical relevancy. We found the suboccipital artery of Salmon in 10 (67%) of 15 embalmed adult cadavers. This frequency is considerably higher than that in previous reports. Two (20%) of the 10 cadavers demonstrated bilateral and symmetrical suboccipital arteries of Salmon (one artery on each side). Four (40%) of the 10 cadavers had an arrangement of two parallel suboccipital arteries of Salmon on one side, and one on the contralateral side. Three (30%) of the 10 cadavers displayed an asymmetrical unilateral arrangement (only one artery). One (10%) of the 10 cadavers displayed the unique arrangement of three arteries of Salmon on one side and one artery on the contralateral side. This study adds to a limited, but growing, body of knowledge by providing photographic evidence of the course and arrangement of these arteries and, therefore, can be of value to surgeons and other clinicians whose procedures focus on the suboccipital region.

A New Genus and Species of Gyrodactylid (Monogenea) From Silver Hake, Merluccius Bilinearis, in the Bay of Fundy, New Brunswick, Canada

Gyrocerviceanseris passamaquoddyensis n. gen., n. sp. is described from the gills of silver hake, Merluccius bilinearis , in Passamaquoddy Bay, southwestern New Brunswick, Canada. Diagnostic features include an oval haptor with asymmetrically distributed marginal hooks (3 pairs anterior, 5 pairs posterior) and a prominent muscular flange on the lateral margins, between the anterior and posterior groups of hooks. The hamuli are well developed, with a straight point, a short shaft, and an elongate, blade-like ventral root having a ventrally directed, gooseneck-shaped tip. The ventral bar is rectangular, with a small, hourglass-shaped posterior membrane. There is no dorsal bar. The marginal hook sickle is sharply curved, with a long fine point, an upturned toe, a small heel, and a straight handle. A partial DNA sequence from 18S rDNA was generated and found to be over 11% divergent from its closest matches in GenBank. However, it was less divergent (7.8%) from a previously unpublished sequence of Gyrodactylus emembranatus Malmberg, 1970 , suggesting this species is its closest known relative. Interestingly, both species have almost identical marginal hook sickles and a male copulatory organ (MCO) with small spines in multiple arched rows. Gyrocerviceanseris n. gen. is the sixth genus of viviparous monogeneans to be described from marine and estuarine fishes of the northwestern Atlantic Ocean.

A New Gyrodactylid Species From Cobitis granoei (Rendahl) (Cobitidae) in Central China

Gyrodactylus granoei n. sp. (Monogenea: Gyrodactylidae) is described from the fins and body surface of the spine loach, Cobitis granoei (Rendahl) (Cobitidae), in central China. It resembles a suite of species from cyprinid and cobitid fishes that have short, compact hamuli, a ventral bar with no obvious anterolateral projections, a linguiform posterior membrane, a male copulatory organ with small hooks in multiple rows, a simple cylindrical dorsal bar, and short marginal hooks, with an expanded sickle heel. Of these, the new species resembles most closely Gyrodactylus micracanthus Hukuda, 1940 from Misgurnus anguillicaudatus (Cantor) (Cobitidae), but it is identified by the length of the hamuli and the morphology of dorsal and ventral bars. When searched using BLAST, sequence data (829 bp) spanning the ITS1, 5.8s, and ITS2 region did not return an identical match; close similarity (82-88%) was found with sequenced members of the subgenus Gyrodactylus. It is suggested that the new species is part of a freshwater lineage that has radiated successfully among cyprinid fishes in North America, Europe, and Asia, and some of their predator and amphibian neighbors.

Rapid, bloody, and blinding diabetic retinopathy

Rapid, bloody, and blinding diabetic retinopathy

Kimmerle's Anomaly as a Possible Causative Factor of Chronic Tension-Type Headaches and Neurosensory Hearing Loss: Case Report and Literature Review

ABSTRACTKimmerle's anomaly also known as ponticulus posticus is a common anatomical variation of the atlas, the first cervical vertebra. It is the product of the complete or incomplete ossification of the posterior atlanto-occipital membrane over the vertebral artery groove resulting in the formation of a foramen (arcuate foramen) containing the vertebral artery and the posterior branch of the C-1 spinal nerve. This variation has been associated with vertebro-basilar insufficiency symptoms, various types of headaches, and acute hearing loss. The aim of the present study is to substantiate whether Kimmerle's anomaly is the possible cause of chronic tension-type headaches and neurosensory-type hearing loss in a patient with a known history of headaches and accompanied unilateral hearing loss. The headaches demonstrated the characteristics of the chronic tension-type; the audiometric investigation concluded the hearing loss to be of the neurosensory type; whereas, the imaging examinations revealed the existence of a partial osseous bridge, that is an incomplete arcuate foramen (ponticulus posticus or Kimmerle's anomaly) on the upper surface of atlas. Both the clinical and the radiological findings of this case are indicative of a possible connection between Kimmerle's anomaly and the manifestation of chronic tension-type headaches and neurosensory-type hearing loss.

Vangl2 directs the posterior tilting and asymmetric localization of motile primary cilia

Cilia are microtubule-based organelles that project into the extracellular space, function in the perception and integration of environmental cues, and regulate Hedgehog signal transduction. The emergent association of ciliary defects with diverse and pleiotropic human disorders has fuelled investigations into the molecular genetic regulation of ciliogenesis. Although recent studies implicate planar cell polarity (PCP) in cilia formation, this conclusion is based on analyses of proteins that are not specific to, or downstream effectors of PCP signal transduction. Here we characterize zebrafish embryos devoid of all Vangl2 function, a core and specific component of the PCP signalling pathway. Using Arl13b-GFP as a live marker of the ciliary axoneme, we demonstrate that Vangl2 is not required for ciliogenesis. Instead, Vangl2 controls the posterior tilting of primary motile cilia lining the neurocoel, Kupffer's vesicle and pronephric duct. Furthermore, we show that Vangl2 is required for asymmetric localization of cilia to the posterior apical membrane of neuroepithelial cells. Our results indicate a broad and essential role for PCP in the asymmetric localization and orientation of motile primary cilia, establishing directional fluid flow implicated in normal embryonic development and disease.