Posterior Extension Research Articles

Three echinostome species from wild birds in the Republic of Korea.

Three echinostome species, i.e., Patagifer bilobus, Petasiger neocomense, and Saakotrema metatestis, are newly recorded in the trematode fauna of the Republic of Korea. They were recovered from 3 species of migratory birds (Platalea minor, Podiceps cristatus, and Egretta garzetta), which were donated by the Wildlife Center of Chungbuk (WCC) and the Conservation Genome Resource Bank for Korean Wildlife (CGRB). Only 1 P. bilobus specimen was recovered from the intestine of a black-faced spoonbill (P. minor), and characterized by the bilobed head crown with a deep dorsal incision and 54 collar spines. Twenty P. neocomense were recovered from the intestine of a great crested grebe (P. cristatus), and they had a well-developed head crown with 19 spines and 2 testes obliquely located at the posterior middle of the body. Total 70 S. metatestis were collected from the bursa of Fabricius of 1 little egret (E. garzetta). It is characterized by stout tegumental spines covered in the entire leaf-shaped body, posterior extension of the uterus, presence of the uroproct and a well-developed head crown with 12 pairs of collar spines on each side. By the present study, these 3 echinostome species are newly added to the trematode fauna in Korea.

Fluoroscopic, magnetic resonance imaging, and electrophysiologic assessment of shoulders with massive tears of the rotator cuff

It was the purpose of this paper to analyze structural, functional, and electrophysiologic variables that may determine preserved overhead function for patients with massive rotator cuff tears. Nineteen patients (20 shoulders) were prospectively included in either the pseudoparalytic (n = 9) or the non-pseudoparalytic group (n = 11). Fatty infiltration was graded according to Goutallier, and anterior (subscapularis) and posterior (infraspinatus and teres minor) tear extension was graded 0 (no involvement) to 4 (full tear) on magnetic resonance imaging. Glenohumeral and scapulothoracic rhythm was assessed by fluoroscopic motion analysis, and electromyographic evaluation of the deltoid muscle was performed. We found no significant difference of fatty infiltration of the supraspinatus (3.9 vs 3.6), infraspinatus (3.9 vs 3.8), and teres minor (1.7 vs 0.6) or of the posterior tear extension (2.6 vs 2.0) between pseudoparalytic and non-pseudoparalytic shoulders. Global tear extension in the parasagittal plane (205° vs 163°) and subscapularis involvement (2.6 vs 1.2), however, showed significant differences between the two groups, and no patient with a full-thickness supraspinatus and infraspinatus tear with extension into the inferior half of the subscapularis was able to lift the arm to 90°. Fluoroscopic assessment revealed almost total loss of active glenohumeral abduction in the pseudoparalytic group. Despite global tear extension, the single most important predictor for preserved shoulder function is the integrity of the inferior subscapularis insertion. Furthermore, electromyographic evaluation identifies a well-differentiated deltoid innervation as beneficial for a well-preserved shoulder function, but it does not protect from pseudoparalysis.

Compartment-dependent activities of Wnt3a/β-catenin signaling during vertebrate axial extension

Extension of the vertebrate body results from the concerted activity of many signals in the posterior embryonic end. Among them, Wnt3a has been shown to play relevant roles in the regulation of axial progenitor activity, mesoderm formation and somitogenesis. However, its impact on axial growth remains to be fully understood. Using a transgenic approach in the mouse, we found that the effect of Wnt3a signaling varies depending on the target tissue. High levels of Wnt3a in the epiblast prevented formation of neural tissues, but did not impair axial progenitors from producing different mesodermal lineages. These mesodermal tissues maintained a remarkable degree of organization, even within a severely malformed embryo. However, from the cells that failed to take a neural fate, only those that left the epithelial layer of the epiblast activated a mesodermal program. The remaining tissue accumulated as a folded epithelium that kept some epiblast-like characteristics. Together with previously published observations, our results suggest a dose-dependent role for Wnt3a in regulating the balance between renewal and selection of differentiation fates of axial progenitors in the epiblast. In the paraxial mesoderm, appropriate regulation of Wnt/β-catenin signaling was required not only for somitogenesis, but also for providing proper anterior–posterior polarity to the somites. Both processes seem to rely on mechanisms with different requirements for feedback modulation of Wnt/β-catenin signaling, once segmentation occurred in the presence of high levels of Wnt3a in the presomitic mesoderm, but not after permanent expression of a constitutively active form of β-catenin. Together, our findings suggest that Wnt3a/β-catenin signaling plays sequential roles during posterior extension, which are strongly dependent on the target tissue. This provides an additional example of how much the functional output of signaling systems depends on the competence of the responding cells.

Evaluation of iris and iridociliary body lesions with anterior segment optical coherence tomography versus ultrasound B-scan

AimsTo compare anterior segment optical coherence tomography (AS-OCT) with ultrasound B-scan (USB) in evaluating iris and iridociliary body lesions.MethodsImage features and resolution comparison between AS-OCT and USB in 126 patients...

The Modified Mid-Anterior Portal for Hip Arthroscopy

The modified mid-anterior portal is a utilitarian hip arthroscopy working portal that permits dual-portal comprehensive surgery for femoroacetabular impingement and related chondrolabral procedures without the need for interportal exchange. Its distal location facilitates labral reparative and reconstructive procedures while minimizing iatrogenic acetabular chondral damage. The relatively lateral location permits instrument navigation not only along the anterosuperior acetabular rim and anterolateral proximal femur typically required for acetabuloplasty and femoroplasty but even to the posterior regions of the hip in cases of global pincer femoroacetabular impingement and posterior extensions of cam morphology and the anteromedial proximal femur while avoiding direct injury to the lateral femoral cutaneous nerve.

A new and aberrant species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Madagascar.

In this paper we report a new species of Dugesia of the family Dugesiidae from Madagascar, representing the fourth species of freshwater planarian known from this global biodiversity hotspot. In some respects the new species is aberrant, when compared with its congeners, being characterized by a head with smoothly rounded auricles, a peculiar course of the oviducts, including the presence of a common posterior extension, and by the asymmetrical openings of the vasa deferentia at about halfway along the seminal vesicle. Further, it is characterized by a ventral course of the ejaculatory duct with a terminal opening, very long spermiducal vesicles and unstalked cocoons. Its diploid chromosome complement with 18 chromosomes represents an uncommon feature among fissiparous species of Dugesia.

Pelvic and reproductive structures in placoderms (stem gnathostomes).

Newly discovered pelvic and reproductive structures within placoderms, representing some of the most crownward members of the gnathostome stem group and the most basal jawed vertebrates, challenge established ideas on the origin of the pelvic girdle and reproductive complexity. Here we critically review previous descriptions of the pelvic structures in placoderms and reinterpret the morphology of the pelvic region within the arthrodires and ptyctodonts, in particular the position of the pelvic fin and the relationship of the male clasper to the pelvic girdle. Absence of clear articular surfaces on the clasper and girdle in the Arthrodira, along with evidence from the Ptyctodontida, suggest that these are separate structures along the body. We describe similarities between the pectoral and pelvic girdles and claspers, for example, all these have both dermal and perichondral (cartilaginous) components. Claspers in placoderms and chondrichthyans develop in very different ways; in sharks, claspers develop from the pelvic fin while the claspers in placoderms develop separately, suggesting that their independent development involved a posterior extension of the 'competent stripes' for fin development previously limited to the region between the paired pectoral and pelvic fins. Within this expanded zone, we suggest that clasper position relative to the pelvic fins was determined by genes responsible for limb position. Information on early gnathostome reproductive processes is preserved in both the Ptyctodontida and Arthrodira, including the presence of multiple embryos in pregnant females, embryos of differing sizes and of different sexes (e.g. male claspers preserved in some embyros). By comparison with chondrichthyans, these observations suggest more complex reproductive strategies in placoderms than previously appreciated.

Complex anatomy of the sphenoid sinus: a radiographic study and literature review.

Objectives Nasal endoscopic approaches to the sphenoid sinus are challenging. Variations in septation, shape, and dimensions have a critical impact on surgical planning of the skull base. Previous anatomical studies have small numbers or a limited description of this complex structure. The present study is a radiographic analysis of the septation and dimensions of the sphenoid sinus. Design and Methods High-resolution surgical-guidance computed tomography images of the sinuses from 90 patients at a tertiary care medical center between 2002 and 2007 were studied. Multiple anatomical measurements from axial and sagittal images were obtained and analyzed with imaging and statistical software. Results Of the 90 patients studied, 9% had presellar, 37% sellar, and 54% postsellar pneumatization. In 34%, the posterior extent of the intersinus septum involved the bony covering of the carotid artery. The average presellar width of the sinus was 1.3 cm, the average midline presellar depth was 1.4 cm, and the average infrasellar midline depth was 2.6 cm. Conclusions Approaching the skull base through the sphenoid sinus requires a tailored process based on anatomy. Septal involvement of the carotid artery occurs frequently. Pneumatization patterns are potentially disorienting, and awareness of the sinus's posterior and lateral extensions is critical.

Cochlear implantation standards – Results of a survey

Results One-hundred and twenty-one responses were recorded, coming from 43 nations in the 5 continents (Fig. 1). Sixty-two otologists (53%) have considerable experience, each having performed more than 100 implantation surgeries. This experienced group of surgeons perform most of the bilateral and sequential operations (P< 0.01 and P< 0.05, respectively). Single-stage bilateral CI surgery is preferred by 54% of surgeons. CI in SSD is seldom performed. Implantation of electric-acoustic stimulation devices is performed by 37% of the respondents. Senior surgeons are more often involved in implantation surgery at extreme ages (P< 0.001). Significant changes in the surgical procedure are recommended for very young children (P< 0.05). No changes in the standard implantation procedure are recommended for the elderly. In the routine radiological assessment of the temporal bone, plain X-rays are performed by 2% of respondents preoperatively and 68% postoperatively. Computed tomography is performed by 91% preoperatively and 12% postoperatively. Seventy-four per cent of surgeons routinely obtain magnetic resonance preoperatively. These results did not vary by the surgeon group. Thirty-five per cent of surgeons are of the opinion that the type and shape of the electrode array, and the insertion technique, can significantly influence CI outcomes. Opinions were expressed about electrode array shape (n= 15), length (n= 14), depth of insertion (n= 11), best technique to preserve residual hearing (n= 10), and position of contacts (n= 8) (Fig. 2). Sixty-four per cent of surgeons always use facial nerve monitoring. Fifteen per cent of surgeons utilize facial nerve monitoring only in selected cases. Almost all surgeons use antibiotic prophylaxis perioperatively (96%). Custom-made instruments are present in 39% of CI surgical kits. Half of the respondents pay attention to a cosmetic hair shave. A small skin incision is preferred (55%) to a standard incision (20%). Minimally invasive incisions are also common (24%). Young surgeons rely more often than senior surgeons on a traditional skin incision with a posterior extension over the receiverstimulator area (P< 0.001). Fifty-five per cent of surgeons utilize a bilayer flap while 40% use a full thickness flap. Mastoidectomy and posterior tympanotomy are preferred by 95% of the respondents. The insertion of the array through the round window (65%) is favoured over a promontory cochleostomy (35%) and is generally preferred by more experienced surgeons (P< 0.05). Half of the respondents, and more often senior surgeons (P< 0.001), rely on soft insertion techniques (Fig. 3). The receiver-stimulator is secured by sutures passed through bone (40%) or periosteum (30%), screws (9%), or by other techniques (23%) (Fig. 4). Correspondence to: Enrico Muzzi, MD Audiology and ENT Unit, Department of Pediatrics, Institute for Maternal and Child Health – IRCCS “Burlo Garofolo”, Via dell’Istria 65/1, 34137 Trieste, Italy. Email: enrico.muzzi@burlo.trieste.it, enr.muz@gmail.com

Finite element analysis of minimal invasive transforaminal lumbar interbody fusion.

The purpose of our study is to develop and validate three-dimensional finite element models of transforaminal lumbar interbody fusion, and explore the most appropriate method of fixation and fusion by comparing biomechanical characteristics of different fixation method. We developed four fusion models: bilateral pedicle screws fixation with a single cage insertion model (A), bilateral pedicle screws fixation with two cages insertion model (B), unilateral pedicle screws fixation with a single cage insertion model (C), and unilateral pedicle screws fixation with two cages insertion model (D); the models were subjected to different forces including anterior bending, posterior extension, left bending, right bending, rotation, and axial compressive. The von Mises stress of the fusion segments on the pedicle screw and cages was recorded. Angular variation and stress of pedicle screw and cage were compared. There were differences of Von Mises peak stress among four models, but were within the range of maximum force. The angular variation in A, B, C, and D decreased significantly compared with normal. There was no significant difference of angular variation between A and B, and C and D. Bilateral pedicle screws fixation had more superior biomechanics than unilateral pedicle screws fixation. In conclusion, the lumbar interbody fusion models were established using varying fixation methods, and the results verified that unilateral pedicle screws fixation with a single cage could meet the stability demand in minimal invasive transforaminal interbody fusion.

Symptomatic vertebral hemangiomas during pregnancy

Symptomatic vertebral hemangiomas during pregnancy are rare, as only 27 cases have been reported in the literature since 1948. However, symptomatic vertebral hemangiomas can be responsible for spinal cord compression, in which case they constitute a medical emergency, which raises management difficulties in the context of pregnancy. Pregnancy is a known factor responsible for deterioration of these vascular tumors. In this paper, the authors report 2 clinical cases of symptomatic vertebral hemangiomas during pregnancy, including 1 case of spontaneous fracture that has never been previously reported in the literature. The authors then present a brief review of the literature to discuss emergency management of this condition. The first case was a 28-year-old woman at 35 weeks of gestation, who presented with paraparesis. Spinal cord MRI demonstrated a vertebral hemangioma invading the body and posterior arch of T-3 with posterior epidural extension. Laminectomy and vertebroplasty were performed after cesarean section, allowing neurological recovery. The second case involved a 35-year-old woman who presented with spontaneous fracture of T-7 at 36 weeks of gestation, revealing a vertebral hemangioma with no neurological deficit, but it was responsible for pain and local instability. Treatment consisted of postpartum posterior interbody fusion. With a clinical and radiological follow-up of 2 years, no complications and no modification of the hemangiomas were observed. A review of the literature reveals discordant management of these rare cases, which is why the treatment course must be decided by a multidisciplinary team as a function of fetal gestational age and maternal neurological features.

Two types of lateral extension in juvenile nasopharyngeal angiofibroma: diagnostic and therapeutic management

Juvenile nasopharyngeal angiofibroma is a benign, locally aggressive nasopharyngeal tumor. Apart from anterior lateral extension to the pterygopalatine fossa, it may spread laterally posterior to the pterygoid process, showing posterior lateral growth pattern, which is less common and more difficult to identify during surgery. We analyzed the routes of lateral spread, modalities useful in its diagnosis, the incidence of lateral extension and its influence on outcomes of surgical treatment. The records of 37 patients with laterally extending JNA treated at our institution between 1987 and 2011 were retrospectively evaluated. Computed tomography was performed in all patients and magnetic resonance imaging in 17 (46 %) patients. CT and MRI were evaluated to determine routes and extension of JNA lateral spread. Anterior lateral extension to the pterygopalatine fossa occurred in 36 (97 %) patients and further to the infratemporal fossa in 20 (54 %) patients. In 16 (43 %) cases posterior lateral spread was observed: posterior to the pterygoid process and/or between its plates. The recurrence rate was 29.7 % (11/37). The majority of residual lesions was located behind the pterygoid process (7/11). Recurrent disease occurred in 3/21 patients with anterior lateral extension, in 7/15 patients with both types of lateral extensions and in 1 patient with posterior lateral extension. JNA posterior lateral extension may spread behind the pterygoid process or between its plates. The recurrence rate in patients with anterior and/or posterior lateral extension is significantly higher than in patients with anterior lateral extension only. Both CT and MRI allow identification of the anterior and posterior lateral extensions.

Distal insertions of the semimembranosus tendon: MR imaging with anatomic correlation

The purpose of this study is to investigate the distal insertions of the semimembranosus tendon with MR imaging, correlated with findings in cadavers. Four fresh cadaveric specimens were studied with 3-T MR imaging. Sequences included proton density (PD) sequences (TE, 13; TR, 4957; FOV, 170 × 170; matrix, 424 × 413; NA, 2; slice thickness, 2.5 mm) in the axial, coronal, and sagittal planes and 3D fast field echo (FFE) sequences (TR 9.4; TE 6.9; FOV, 159 × 105; matrix, 200 × 211; NA, 2; slice thickness, 0.57 mm). One specimen was dissected and three specimens were sectioned with a bandsaw in the axial, coronal, and sagittal plane. The sections were photographed and correlated with MR images. To standardize the analysis, the semimembranosus muscle and tendon were assessed at seven levels for the axial sections, and at three levels for the coronal and sagittal sections. Anatomic dissection revealed six insertions of the distal semimembranosus tendon: direct arm, anterior arm, posterior oblique ligament extension, oblique popliteal ligament extension, distal tibial expansion (popliteus aponeurosis), and meniscal arm. Axial MR images showed five of six insertions: direct arm, anterior arm, oblique popliteal ligament extension, posterior oblique ligament extension, and distal tibial expansion. Sagittal MR images showed four of six insertions: direct arm, anterior arm, oblique popliteal ligament arm, and distal tibial expansion. Sagittal MR images were ideal for showing the direct arm insertion, but were less optimal than the axial images for showing the other insertions. The anterior arm was seen but volume averaging was present with the gracilis tendon. Coronal MR images optimally revealed the anterior arm, although magic angle artifact was present at its posterior aspect. The common semimembranosus tendon and meniscal arm were also well depicted. The division in anterior arm, direct arm, and oblique popliteal ligament arm was poorly seen on coronal images due to volume averaging. Although the anatomy of the distal semimembranosus tendon is complex, six different semimembranosus insertions can be identified on routine proton density and FFE sequences at 3 T. Analysis of images at defined levels in the three imaging planes simplifies MR interpretation of the anatomy of the distal semimembranosus tendon.

Biomechanical comparison of different nailing angles in pedicle screw fixation plus intervertebral fusion in lumbosacral finite element models

Objective To determine the optimal nailing angle by comparing the biomechanical properties of different nailing angles in pedicle screw fixation plus intervertebral fusion in lumbosacral finite element models. Methods We established the finite element models of normal lumbosacral vertebral IA-SI segments whose intervertebral disc of L5-SI was removed using CT scan, three-dimensional recon- struction by software Mimicsl3.0, surface treatment by software Freeform6.0 and preprocessing by software Ansysl0. O, respectively. Fixation with posterior pedicle screws and intervertebral fusion was simulated in the finite element models. The models were divided into 3 groups according to the different nailing angles. Model 1： the screws above and below were inserted by angle of 0~ transversely with the sagittal view parallel to the end plate. Model 2： the screws above and below were inserted by an angle of 15° transversely with the sagittal view parallel to the end plate. Model 3： the screw above was inserted by an angle of 0° transversely with the sagittal view uplifted by an angle of 15° while the screw below was inserted by an angle of 0° transversely with the sagittal view parallel to the end plate. Then all the models were subjected to torque loads of 5 N · m at anteflexion, posterior extension, left bending and left rotation respectively. The stress distributions ofscrew-rod system, cage, L4. i,5 and S1 were analyzed and compared between the 3 groups. Results The stress distributions of screw-rod system, cage, L4, L5 and SI at anteflexion, posterior extension, left bending and left rotation were the lowest in Model 2. The stress distributions of screw-rod system, cage, 1,4, L5 and SI were respectively 2.96 x 107, 5.65 x l06, 5.76 x 106, 8.06 10 aod 8.51 x 106 N/m2 at anteflexion, re- spectively 2. 98x107, 6. 08x106, 6.49x106, 8.63x106 and 9. 17x106 N/m2 at posterinr extension, respectively 3.06 x 107. 9.71 x 106, 2.39 x 106, 1. 14 x 106 and 8.61 x 106 N/m-＇ at left bending, and re- spectively 2. 96 x 107, 1.00 x 106, 5.76 x 106, 8.06 x 106 and 8.51 x 106 N/m2 at left rotation. The max- imum stresses of screw-rod system and cage in Model l were lower than in Model 3 at anteflexion, posterior extension and left bending. Conclusion In fixation of lumbosacral posterior pedicle screw and interver- tebral fusion, screws parallel to the end plate in the sagittal view and inserted by an inclined inward angle in the transverse position can improve the stress of the whole structure and ease the concentrated stress on screws and vertebral body, preventing breaking and loosening of screw-rod system. Key words: Intervertebral disk; Bone nails; Finite element analysis; Nailing angle

Biomechanical stability of combined use of multiaxial and monoaxial screws in fixation of thoracolumbar burst fractures

Objective To investigate the biomechanical stability of general pedicle screw (monoaxial screw) and multixial screws in treatment of thoracolumbar burst fractures.Methods Six calf fresh-frozen lumbar spines (L1-L5) were selected to produce models of L3 burst fractures.The specimens were assigned to none fracture fixation group,multiaxial screw group (fixation of the fractured vertebra and upper and lower adjacent vertebral bodies with monoaxial screws,) and combined screw group (fixation of the upper adjacent vertebral body with monoaxial screws and of the fractured vertebra and lower adjacent vertebral body with multiaxia[screw).Differences in range of motion and neutral zone at level of L2-L4 at six movement directions were compared between groups.Results Range of motion and neutral zone had insignificant differences between the two groups under anterior flexion,posterior extension,lateral bending,and rotation (P ＞ 0.05),but significant difference in comparison with none fracture fixation group (P ＜ 0.01).Conclusions Combined use of multixial and monoaxial screws produces no effect on biomechanical stability of the internal fixation.Multiaxial plus monoaxial screw fixation and monoaxial screw fixation can both provide reliable biomechanical stability. Key words: Spinal fractures ; Internal fixators ; Joint instability

Phylogeny and diversity of Timiriaseviinae ostracods (Podocopida, Cytheroidea) with description of one new species from arid Western Australia

Gomphodella De Deckker, 1981 belongs to the subfamily Timiriaseviinae, and it inhabits almost exclusively subterranean waters of Western Australia. We describe the ninth species of the genus, G. alexanderi sp. nov., from bore-holes in the Pilbara region. The species is closely related to G. yandii Karanovic, 2009 and G. quasihirsuta Karanovic, 2009, but can be distinguished by its shell morphology, appearance of the hemipenis, and chaetotaxy of the antenna. We also report on G. yandii and G. cf. martensi Karanovic, 2009, collected sympatrically with the new species, indicating some new characters not mentioned in the original descriptions. We show for the first time that Gomphodella has an inverse lophodont hinge, instead of a lophodont one as previously believed. The significance of the hinge structure, sulci, and other shell characters in the systematics of Timiriaseviinae are discussed. In addition, the posterior extension on the female body, the so-called ‘forked organ’, is here reported for the first time in the genus Gomphodella. Because these characters provide a new insight into the phylogenetic relationships of Timiriaseviinae we performed two cladistic analyses: one including only nine genera with living representatives, the other including 17 genera. They resulted in one and 23 equally parsimonious trees respectively. Inclusion of the fossil taxa significantly changes the tree topology, but on both trees the Gondwanan lineage, Cytheridella Daday, 1905/Gomphocythere Sars, 1924/Gomphodella is strongly supported, as well as a close connection between the South American semi-terrestrial and some fossil genera. Another well-supported clade is formed by the genera Kovalevskiella Klein, 1963, Frambocythere Colin, 1980 and Rosacythere Colin, 1980. Maps of distribution of Recent genera and geological age of Timiriaseviinae are also presented here.http://zoobank.org/urn:lsid:zoobank.org:pub:E3041FDD-7233-4733-841C-98549108FE61

Esophageal submucosal tumor-a red flag in patients receiving thoracic aortic aneurysmal stent-graft.

A 75-year-old man presented to our hospital with symptoms of fever, abdominal pain, intermittent hematemesis and melena for 2 days. The patient underwent stent-graft placement for a thoracic aortic aneurysm (TAA) 6 months prior to this presentation. Seven days ago, he suffered from dyspepsia; an upper gastrointestinal (UGI) endoscopy indicated a submucosal tumor (Fig. 1A, arrow) in the middle portion of the esophagus. Endoscopic biopsy was then conducted, which disclosed inflammatory cells. Upon hospitalization, laboratory data indicated marked anemia with a hemoglobin of 6 g/dL. Chest radiography revealed a widening of the mediastinum and a TAA stent-graft (Fig. 1B, arrow) in place without unusual mediastinal air. Emergent UGI endoscopy was performed due to intermittent hematemesis and anemia. It demonstrated an ulcerative hole located in the middle portion of the esophagus (Fig. 1C, arrow indicates the ulcerative hole). Due to fever of an unknown focus, contrast-enhanced computed tomography (CT) of chest was done in order to rule out any occult infectious process associated with the stent-graft, showing a gas-forming peri-stent-graft abscess formation with posterior mediastinal extension (Fig. 1D, pre-contrast CT; Fig. 1E early-phase CT; Fig. 1F, reconstructed image; Fig. 1E to F, white star indicates the abscess and white arrow indicates the nasogastric tube). The radiographic and endoscopic findings were consistent with an aortoesophageal fistula formation (AEF). The patient was put on broad-spectrum antibiotics, but succumbed to sepsis before emergent operation. Fig. 1 Aortoesophageal fistula is a rare complication after thoracic endovascular aortic repair. The rate of incidence is around 1.9%.1) AEF formation after thoracic endovascular aortic repair is probably associated with the erosion of the esophageal wall by an infected stent-graft, pressure necrosis caused by the direct compression of a self-expanding stent-graft, or a compromised blood supply of the esophageal wall.1),2) Presentations of AEF include new-onset fever, chest pain or symptoms of UGI bleeding, such as hematemesis or melena.3) Contrast-enhanced CT is a useful imaging modality if AEF is suspected clinically. When a new heterogeneous mass with some air bubbles inside is found on the CT, subsequent UGI endoscopy can be performed to confirm the diagnosis. Endoscopic findings vary from submucosal tumor, ulceration, small defect of esophagus or direct visualization of a stent-graft. The mortality rate of AEF is extremely high if treated conservatively.3) Surgical intervention is challenging and important for the management of this devastating complication.

A suggestion of modified classification of trigeminal schwannomas according to location, shape, and extension.

BackgroundComprehensive knowledge of the anatomical features of trigeminal schwannomas (TSs) is essential in planning surgery to achieve complete tumor resection. In the current report, we propose a modified classification of TSs according to their location of origin, shape, and extension into the adjacent compartment, and discuss appropriate surgical strategies with this classification.MethodsWe retrospectively analyzed 49 patients with TS who were treated surgically by a single neurosurgeon at the Asan Medical Center between 1993 and 2013.ResultsThere were 22 males and 27 females, with the median age of 40 years (range, 21-75 years). Median tumor size was 4.0 cm in diameter (2.0-7.0 cm). Tumors were classified as follows: Type M (confined to the middle fossa; 8 cases, 19.0%), P (confined to the posterior fossa; 2 cases, 4.8%), MP (involving equally both middle and posterior fossae; 5 cases, 11.9%), Mp (predominantly middle fossa with posterior fossa extension; 6 cases, 14.3%), Pm (predominantly posterior fossa with middle fossa extension; 16 cases, 38.1%), Me (predominantly middle fossa with extracranial extension; 4 cases, 9.5%). Surgical approach was chosen depending on the tumor classification. More specifically, a frontotemporal craniotomy and extradural approach with or without zygomatic or orbitozygomatic osteotomy was applied to M- or Mp-type tumors; a lateral suboccipital craniotomy with or without suprameatal approach was applied to the majority of P- or Pm-type tumors; and a posterior transpetrosal approach was used in four tumors (three Pm and one MP). Gross total resection was achieved in 95.9% of patients, and the overall recurrence rate was 4.1% (2 patients). Postoperatively, trigeminal symptoms were improved or unchanged in 51.0% of cases (25 patients). Surgical complications included meningitis (5 patients) and cerebrospinal fluid leakage (3 patients). There was no mortality.ConclusionTSs are well to be classified with our modified classification and able to be removed effectively and safely by selecting appropriate surgical approaches.

Growth Patterns of Pituitary Adenomas and Histopathological Correlates

The factors associated with pituitary adenoma (PA) growth rate remain unclear. The objective of the study was to establish whether the preoperative growth and extension pattern of PA can predict postoperative growth rate and recurrence in addition to whether the PA growth rate correlates with proliferation and growth factor expression. One hundred fifty-three consecutive patients who underwent surgery for pituitary adenoma from 1999 to 2011 at Toronto Western Hospital were identified. The PA growth rate was measured both pre- and postoperatively, and its association with patient demographics, magnetic resonance imaging, and histolopathological parameters was determined. The preoperative growth rate was associated with age (P = .0001), suprasellar growth (P = .003), the presence of a cyst/hemorrhage (P = .004), the mindbomb homolog-1 (P = .005), fibroblast growth factor receptor-4 positivity (P = .047), and p27 negativity (P = .007). After surgery, there were 34.6% residual volumes, which were associated with older age (P = .038) and also with growth patterns including anterior, posterior, suprasellar, and cavernous sinus extension (P = .001); 43.3% of these residuals grew and postoperative growth rate was calculated. Pre- and postoperative growth rates were correlated (r = 0.497, P = .026). Postoperative growth rate was associated with age (P = .015) and gender (P = .017). Our data suggest that the growth rate of PAs are influenced by various patient- and tumor-specific characteristics including the age and sex of the patient, the specific subtype of PA, its hormonal activity, its immunohistochemical profile including the mindbomb homolog 1 labeling index status, and its preponderance for different growth directions relative to the pituitary fossa. Furthermore, the pre- and postoperative PA growth rates were correlated, suggesting that postoperative PA growth rates can be predicted, in part, by preoperative growth rates, thus better informing postoperative outcome.

Management of Vascular Malformations in Dangerous Area of Oral Cavity: The Iranian Experience and Review of Treatment Modalities

Aim: To evaluate the effect of a highly potent corticosteroid (dexamethasone) in the treatment of vascular malformation when the location is difficult to reach and complications such as uncontrolled bleeding is predictable in surgery. Background: Vascular malformation is not a common lesion in oral cavity especially in alveolar ridge with extension to the pillar uvula. These lesions arise from capillary or venous malformations with various surgical or non-surgical treatment modalities. Case Description: We performed weekly intralesional injection of dexamethasone in a patient with a vascular malformation in alveolar ridge extending to the lingual side of alveolar ridge and posterior extension to the uvula. Complete resolution of lesion was observed after 6th injection. Conclusion: Intralesional injection of dexamethasone is a potentially curative method to treat oral vascular malformation. Clinical Significance: Injection of dexamethasone is a simple and cost-effective therapy that can be used as a safe treatment for vascular malformations prior to or as a substitute for surgery.