Posterior Extension Research Articles

An integrated overview of AV node physiology

The atrioventricular (AV) node generates half of the AV delay needed for blood pumping and filters atrial impulses that could otherwise induce life-threatening ventricular arrhythmias. It is also a pacemaker and a key target in the treatment of cardiac arrhythmias. The special roles of the AV node primarily arise from its slow conduction, long refractory period, and cellular automaticity. However, efforts to establish the dynamics of these properties and their interaction led to many controversies. In fact, the AV node's behavior is so complex that it seems to escape broadly applicable rules. This review summarizes progresses made in resolving these issues and in integrating the multiple roles of the AV node within a common functional model. Presented evidence shows that the rate-dependent conduction and refractory properties of the AV node can be reliably characterized and reconciled from nodal responses to S1 S2 S3 protocols. It also supports the concept that dual pathways constitute a feature of the normal AV node and account for its overall conduction and refractory properties. In this model, the posterior extension and compact node provide the core of the slow and fast pathway, respectively. The transitional tissues and lower nodal bundle provide a common proximal and distal pathway, respectively. These pathways would also support bidirectional conduction. The dual pathway involvement can also be extended to widely variable AV nodal responses, such as Wenckebach cycles, hysteresis, and ventricular response to atrial fibrillation. In brief, the intricate AV nodal behavior may obey a limited set of accessible and definable rules.

Effects of Posterior Extension on the Clinical Characteristics and Surgical Outcomes of Ciliary Body Tumors

Effects of Posterior Extension on the Clinical Characteristics and Surgical Outcomes of Ciliary Body Tumors

Mystacodon selenensis, the earliest known toothed mysticete (Cetacea, Mammalia) from the late Eocene of Peru: anatomy, phylogeny, and feeding adaptations

Mystacodon selenensis Lambert, Martínez-Cáceres, Bianucci, Di Celma, Salas-Gismondi, Steurbaut, Urbina & Muizon, 2017 is a toothed mysticete that represents the earliest member of the suborder in the current state of knowledge. Its holotype is a relatively complete skeleton from the upper Eocene (early Priabonian, c. 36.4 Ma) Yumaque Member of the Paracas Formation from the southern coast of Peru. The thorough description of this specimen is presented here and reveals numerous similarities with the contemporaneous basilosaurids including the retention of an innominate that originally articulated to the unpreserved hind limb. However, several characters of M. selenensis clearly relate this taxon to the mysticetes, such as the large palate with a dorsoventrally flattened rostrum, the posterior extension of the palate with an infraorbital plate of the maxilla, the shortening of the premaxillary part of the rostrum, the zygomatic process of the squamosal being closely apposed to the postorbital process of the frontal, and the humeral head being oriented more proximally than posteriorly. A parsimony analysis retrieves Mystacodon as the earliest diverging branch of the Mysticeti with no close phylogenetic relationship with Llanocetus the second oldest known mysticete (c. 34.2 Ma). The dental formula of M. selenensis is that of basilosaurids (I 3/3, C 1/1, P 4/4, M 2/3). The anterior teeth (incisors and canine) are distinctly proportionally smaller than in basilosaurids, whereas the cheek teeth are very close in relative length, but are relatively larger than in most other toothed mysticetes (except Coronodon). The large cheek teeth of Mystacodon suggest a raptorial feeding strategy, probably assisted with some degree of suction, as indicated by the large size of the palate. The anterior teeth of the holotype display a subhorizontal apical wear facet and the cheek teeth a moderately sloping wear surface, differing from the subvertical attrition facets of basilosaurids. This pattern suggests an efficient dental abrasion resulting from feeding upon abrasive food items or/and from the ingestion of sediment during prey capture, which could indicate some degree of bottom feeding. On the forelimb, the size and orientation of the acromion, the great length of the deltopectoral crest, the massiveness of the olecranon of the ulna, and the strong radial anterior process indicate powerful shoulder movements, which suggest an active use of the forelimb when foraging for food on the sea floor. The robustness of digits and the pachyosteosclerosis of ribs with pestle-like distal end corroborate such a scenario. Mystacodon selenensis represents a first step in the evolutionary history of feeding adaptations of early mysticetes; the latter are likely to have experimented an abundant set of feeding strategies and were probably very eclectic in prey choice and capture before hyperspecialized filter feeding became widespread in the suborder.

Apharyngogyliauchen callyodontis Yamaguti, 1942 (Digenea) from a New Host, the Common Parrotfish, Scarus psittacus (Scaridae) with Special Reference to its Morphological Intra-SpecificVariations

As part of an on-going study of the helminth parasites collected from the Red Sea fishes, Apharyngogyliauchen callyodontis Yamaguti, 1942 is reported for the first time parasitizing the middle and lower parts of the intestinal tract of Scarus psittacus (Common parrotfish) (Forsskal), collected from the northern Red Sea of Egypt. The encountered helminth was re-described morphologically and morphometrically based on the light microscope study. The current study demonstrated that some taxonomically important, previously unreported morphological and morphometric features, including the variation in; intestinal ceca length, and their posterior extension, testes position relative to ventral sucker, cirrus-sac shape, pars prostatica shape and its extension inside cirrus, genital pore positions from median to nearly submedian, vitelline follicles distribution and its posterior extension, seminal receptacle shape, ovary shape and posterior extension of the uterus. The diagnostic morphological features were elucidated and discussed to provide correct identification of Apharyngogyliauchen species with very careful consideration to avoid overlapping with the closely related species.

Outcomes After Rheumatic Mitral Valve Repair in Children

It has been shown that mitral valve repair is superior to mechanical replacement in children with rheumatic heart disease; however there are limited data on the factors affecting the long-term durability of repaired mitral valves. This study describes outcomes after rheumatic mitral valve repair, with adaptation of a risk score to clarify some novel predictors of repair instability. A total of 79 children (median age, 11.4 years) with rheumatic heart disease underwent their first mitral valve surgery between 1997 and 2015. Patients with concomitant aortic and tricuspid repair were included. Mean follow-up time was 7.72 years. Mitral valve deterioration (defined as cardiac death, reoperation, or recurrent moderate to severe valvular disease) was used as a key end point. Preoperative echocardiographs were analyzed and graded with respect to valvular mobility, subvalvular apparatus alteration, and function. All patients underwent successful mitral valve repair. Seven patients died during follow-up. Kaplan-Meier analysis demonstrated survival at 15 years to be 83%. A total of 38 patients were deemed to have deterioration in mitral valve function, with a rate of freedom from deterioration at 15 years of 28%. The presence of an immobile anterior mitral leaflet preoperatively and the technique of posterior patch extension were shown to be significant determinants of mitral valve deterioration. The outcomes after mitral repair for rheumatic heart disease in the young were in keeping with those reported in previous studies. Although the survival was high, long-term valve stability was poor. These findings suggest that the preoperative finding of a restricted anterior mitral leaflet is a negative predictor of repair durability.

Finite element analysis of fixation of U-shaped sacral fractures

Finite element method (FEM) was used to investigate the biomechanical properties of three types of surgical fixations of U-shaped sacral fractures. Based on a previously established and validated complete lumbar-pelvic model, three models of surgical fixations of U-shaped sacral fractures were established: ① S1S2 passed through screw (S1S2), ② L4-L5 pedicle screw + screw for wing of ilium (L4L5 + IS), and ③ L4-L5 pedicle screw + S1 passed through screw + screw for wing of ilium (L4L5 + S1 + IS). A 400 N force acting vertically downward, along with torque of 7.5 N·m in different directions (anterior flexion, posterior extension, axial rotation, and axial lateral bending), was exerted on the upper surface of L4. Comparisons were made on differences in separation of the fracture gap and maximum stress in sitting and standing positions among three fixation methods. This study showed that: for values of separation of the fracture gap produced by different operation groups in different positions, L4L5 + S1 + IS was far less than L4L5 + IS and S1S2. For internal fixators, the maximum stress value produced was: L4L5 + IS > L4L5 + S1 + IS > S1S2. For the intervertebral disc, the maximum stress value produced by S1S2 is much larger than that of L4L5 + S1 + IS and L4L5 + IS. In a comprehensive consideration, L4L5 + S1 + IS could be prioritized for fixation of U-shaped sacral fractures. The objective of this research is to compare the biomechanical differences of three different internal fixation methods for U-shaped sacral fractures, for the reference of clinical operation.

Endoscopic-assisted maxillectomy: Operative technique and control of surgical margins

BackgroundWhen amenable to radical excision, cancer involving the maxilla is typically treated with maxillectomy followed by adjuvant therapy. Posterior tumor extension beyond the maxillary box leads to the invasion of complex areas, where achieving clear margins may be challenging. MethodsPatients undergoing endoscopic-assisted maxillectomy for nasoethmoidal, maxillary, or hard palate cancer between 2007 and 2017 were included in the study. Surgical technique, margin status, and recurrences were analyzed. Extension of posterior resection was classified in 3 types (type 1: resection of the pterygopalatine fossa; type 2: resection of the pterygoid plates and related muscles; type 3: resection of the upper parapharyngeal space). The analysis of putative risk factors for involvement of margins and local recurrence was performed with special focus on the posterior and medial margin. ResultsThe study included 79 patients (75 with available follow-up; mean: 20.6 months, range: 6–101 months), 37 (46.8%) of whom underwent type 1 resection, 34 (43.0%) type 2, and 8 (10.1%) type 3. According to pT category, 57 (72.2%) tumors were classified as T4a/T4b. Posterior and medial clear margins were achieved in 76/79 (96.2%) and 75/79 (94.9%) patients, respectively. T4b category, extension to the ethmoid, sphenoid sinus, pterygoid process, orbital cavity, and premaxillary tissues were significantly associated with a higher rate of margin involvement. None of the factors was significantly associated with medial margin involvement. ConclusionEndoscopic-assisted maxillectomy combines several refinements including the facilitated detachment of the maxilla from the skull base and precise delineation of the posterior and medial margins of resection.

Preliminary analysis on X-ray in youth neck type of cervical spondylosis with upper crossed syndrome

To analyze the X-ray characteristics in youth neck type of cervical spondylosis with upper crossed syndrome(UCS). The patients who had a neck type of cervical spondylosis with or without UCS were selected from January to October 2017, 20 cases in each group, and 10 normal volunteers were chosen in the study. X-ray examination of lateral and hyperextension-hyperflexion of cervical spine were performed to observe cervical spine angle, angular displacement and adjacent vertebral body slip. The cervical spine angle was (-0.40±9.64)° in the UCS group, significantly less than (14.35±9.01)° in the normal group and (12.34±5.65)° in the non-UCS group(P<0.05). The change of angular displacement of the upper cervical vertebra in anterior flexion and posterior extension was (8.18±4.81)° in UCS group, which was also significantly less than (12.14±3.48)° in the normal group and (12.34±5.65)° in the non-UCS group(P<0.05). The slippage of the vertebral posterior margin of the lower cervical spine in the anterior flexion was 15.41±2.21 in the UCS group, which was significantly greater than 13.26±2.42 in normal group(P<0.05), and was not obviously different from 15.64±2.07 in non-UCS group(P>0.05). In young patients who has a neck type of cervical spondylosis with UCS, the cervical curvature prone to straighten or reverse, the upper cervical flexion and extension are limited, while the lower cervical is in a flexion.

Lesser Trochanteric Fragments in Unstable Pertrochanteric Hip Fractures: A Morphological Study Using Three-Dimensional Computed Tomography (3-D CT) Reconstruction.

BackgroundThe lesser trochanter (LT) posterior cortical extension (LTPE) fragment is important for joint stability during reconstruction in unstable pertrochanteric hip fractures. This study aimed to investigate the morphological characteristics of the LT fragments using three-dimensional computed tomography (3-D CT) reconstruction and to compare clinical outcomes in different subgroups of 31A2 fractures.Material/MethodsA retrospective study included CT images of 58 cases of 31A2 type unstable pertrochanteric fractures, using the Arbeitsgemeinschaft für Osteosynthesefragen and Orthopedic Trauma Association (AO/OTA) classification. After 3-D CT reconstruction, all the displaced fragments were reduced and the morphologic parameters of the LT fragments were measured.ResultsAt the mid-level of the LT, the mean cortical extension of the LT fragment was 33.5 mm in the posterior wall (83%), 19.0 mm in the medial wall (53%). The mean distal cortical extension from the lower edge of the LT was 13.0 mm. The LT fragment occupied 38% of the whole cortical circumference. Comparison of the subgroups showed that the LT fragment of A2.3 had a larger cortical extension in the posterior, medial, and distal cortex. The mean fracture collapse was 4.7 mm in A2.2 fractures and 5.4 mm in A2.3 fractures (p=0.311). Despite the increased size of the LT fragment in subtype A2.3 fracture compared with subtype A2.2 fracture, this did not influence the clinical outcome.ConclusionsThe 3-D morphology of the LT fragment from CT imaging provided a better understanding of the characteristics of subgroups of unstable pertrochanteric fractures, which may improve and guide implant choice.

Biomechanical comparison of percutaneous posterior endoscopic cervical discectomy and anterior cervical decompression and fusion on the treatment of cervical spondylotic radiculopathy

BackgroundCervical spondylotic radiculopathy is a common spinal disease. The traditional surgical treatment consists of anterior cervical decompression and fusion (ACDF), but it presents problems such as trauma and fusion complications. Percutaneous posterior endoscopic cervical discectomy (PPECD) is a new minimally invasive technology that has produced good clinical outcome, but further biomechanical comparisons are needed to guide the clinical work. The goal of this study was to compare the biomechanical characteristics of the two methods by finite element analysis.MethodOn the basis of the computed tomography scanning data of five cases of cervical spondylosis after PPECD surgery, five cases after ACDF surgery, and five non-surgical patients, software (Mimics 15.0, HyperMesh 12.0, and Abaqus 6.13) was adopted to establish a C1–C7 segment 3D finite element model. We also applied 50 N vertical load on the C1 surface and 1.5 Nm torque, simulated the anteflexion, rear protraction, and left and right lateral flexion and rotation, and observed the stability, stress distribution, and Cobb angular change of the surgical section of the cervical vertebra under different working conditions.ResultThe postoperative model under different working conditions demonstrated poorer stability than the non-surgical group, but the stability of the PPECD group was close to that of the non-surgical group. The stability of the ACDF group was the worst, especially when making lateral bending and posterior extension. The ACDF group also showed significant differences. The PPECD group showed uniform stress distribution, whereas the ACDF group was under large stress, which was primarily concentrated in the internal fixation system. In addition, the implant showed the potential for fracture. The Cobb angle of surgery section of the PPECD group was smaller than that of the ACDF group, and the stability of the section was good.ConclusionFrom the perspective of finite element analysis, the cervical vertebrae after PPECD treatment showed good biomechanical performance and stability.

Posterior Mitral Leaflet Extension Using Glutaraldehyde-Treated Autologous Pericardium in Pediatric Patients with Congenital Hypoplastic Posterior Leaflet of the Mitral Valve: Technical Pitfalls and Long-Term Results

Posterior Mitral Leaflet Extension Using Glutaraldehyde-Treated Autologous Pericardium in Pediatric Patients with Congenital Hypoplastic Posterior Leaflet of the Mitral Valve: Technical Pitfalls and Long-Term Results

Fovea-sparing rhegmatogenous retinal detachments: impact of clinical factors including time to surgery on visual and anatomic outcomes.

Evaluate the impact of time to surgery and other clinical factors on visual and anatomic outcomes following surgical repair of fovea-sparing rhegmatogenous retinal detachments (RRD). Visual and anatomic outcomes were analyzed for their association with clinical factors, including lens status, preoperative visual acuity (VA), contralateral RRD, RRD symptom duration, time to surgery, single-operation anatomic success, number of quadrants involved, posterior RRD extent, RRD extent closest to the fovea, number of retinal breaks, quadrants with retinal breaks, and surgery performed Saturday or Sunday versus Monday-Friday. Medical records of 423 eyes with fovea-sparing RRD repaired with pneumatic retinopexy (PR), scleral buckle (SB), pars plana vitrectomy (PPV), and PPV with SB (PPV/SB) were included. Sixty-seven percent and 89% were operated within 24 and 72h of RRD presentation, respectively. Single-operation anatomic success rates were 59%, 89%, 84%, and 92% for PR, SB, PPV, and PPV/SB interventions, respectively. Final anatomic success was 100%. Three clinical factors correlated with faster time to surgery: shorter symptom duration (p < 0.02), RRD superior location (p = 0.001), and posterior extension into the macula (p = 0.01). The time to surgery did not correlate with visual or anatomic outcomes. Two clinical factors positively correlated with postoperative vision: preoperative VA (r > 0.25, p < 0.04) and single-operation anatomic success (p < 0.04). Surgeries performed on Monday through Friday (n = 411) were associated with better anatomic outcomes compared with the limited number performed on Saturday or Sunday (n = 12) (p = 0.005), although a greater proportion of operated cases over the weekend were PR. In the context of the current series, time to surgery did not correlate with visual or anatomic outcomes following the surgical repair of fovea-sparing RRDs. Preoperative VA and single-operation anatomic success correlated with improved visual outcome.

En Bloc Resection with Partial Sacrectomy Helps to Achieve R0 Resection in Locally Advanced Rectal Cancer, Experience from a Tertiary Cancer Center.

Partial sacrectomy is a radical procedure that benefits a select group of patients with locally advanced primary or recurrent rectal cancer with posterior extension and carries potential for significant morbidity. This study was done to evaluate the morbidity and oncological outcome of patients who underwent partial sacral resection for rectal cancer in a tertiary cancer center. Seventeen patients underwent partial sacrectomy during the period from 2011 to 2015. Eleven patients had primary and six had recurrent rectal cancer. All patients were evaluated with MRI pelvis and metastatic evaluation with CT scan of the chest and abdomen and PET scan in patients with recurrent cancer. All patients had resection below the level of S2/S3 junction or lower. Three patients were females and the remaining were males. Median age was 56years. Overall morbidity was 76% and most common morbidity was wound related. The mean estimated relapse-free survival (RFS) for patients treated for primary rectal cancer was 20.3months (95% confidence interval (CI), 12.8-27.9) and the mean estimated overall survival (OS) 23.9months. Estimated mean RFS for patients who were operated for recurrent rectal cancer was 25.6months (95% CI, 17.7-33.5) and the median RFS was yet to reach. Estimated mean OS was 29.7months (95% CI, 15.5-43.8) and the median OS was 39.6months. Partial sacrectomy below the level of S2/S3 junction is a safe approach to facilitate en bloc resection of locally advanced primary and recurrent rectal cancer extending posteriorly with loss of plane with sacrum. In selected patients, this approach can improve survival at the cost of high morbidity.

Anatomic variations associated with antrochoanal polyps.

Although more than a century has passed since antrochoanal polyps (ACPs) were first defined, etiopathogenesis still remains unclear. The aim of this study was to investigate the relationship between ACPs and sinonasal cavity variations. One hundred and forty-four patients with ACP on paranasal sinus computed tomography scans (ACP group) and 160 paranasal sinuses without ACP (control group) were included into the study. The study group was evaluated in respect of the presence of retention cyst in the contralateral maxillary sinus and sinus bone wall sclerosis thickening. Both groups were also compared with respect to the frequency of sinonasal anatomic variations, nasal septal deviation, variations of the uncinate process insertion, concha bullosa, paradoxical middle turbinate, and accessory maxillary sinus ostium. In the ACP group, the cases with septal deviation (SD) were also evaluated whether the deviation convexity was towards the polyp side or the opposite side. In addition, the posterior extension of ACPs were evaluated in three groups as middle meatus, nasopharynx, and oropharynx extension. The prevalence of retention cyst, sinus wall sclerosis thickening, SD, and accessory maxillary ostium was significantly higher in the ACP group. A negative directional correlation was determined between the SD side and ACP side. When the ACP extensions were examined, middle meatus extension was seen in 32.6%, nasopharynx in 56.3%, and oropharynx in 11.1%. Accessory ostium may be an accelerating factor in the transformation of retention cyst to ACP. Furthermore, the changes in the nasal passage airflow on the opposite side suggest that SD contributes to this process.

Molecular and morphological characterization of Paurodontella composticola n. sp. (Nematoda: Hexatylina, Sphaerulariidae) from Iran.

A new species of the genus Paurodontella, P. composticola n. sp., collected from Nazar Abad City, Alborz Province, Iran, is described and illustrated. The new species has a body length of 803–1053 μm (females n = 10) and 620 and 739 μm (males n = 2). The cuticle is weakly annulated with four lateral lines. Cephalic region is annulated and continuous with body contour. The stylet is 8.0 to 9.0 μm long with asymmetrical knobs. Esophageal basal bulb is present with a small posterior extension projecting into the intestine. Excretory pore is situated at the level of esophageal basal bulb region. Post-uterine sac is 5 to 8 μm long and uterus is without diverticulum. Tails of both sexes are similar, short and sub-cylindrical. Males have 24 to 25 μm long bursa leptoderan and spicules 24 or 25 µm long. A non-branching oviduct is present to form a uterine diverticulum; the new species is closely related to five known species of the genus, namely P. asymmetrica, P. balochistanica, P. densa, P. iranica and P. niger. It most closely resembles P. iranica, but differs from it morphologically by a shorter stem-like extension projecting into lumen of intestine and male with sub-cylindrical tail vs conoid. In addition to morphological comparisons, the molecular phylogenetic analyses based on 733 bp of the partial sequence of 28S D2/D3 expansion segments of the large subunit rDNA gene (LSU) revealed this as a new species.

Molecular phylogenetic study of Bealius Massey &amp; Hinds, 1970 (Nematoda: Hexatylina: Sphaerulariidae), with description of B. pinus n. sp. from Iran

Summary Bealius pinus n. sp. is described and illustrated based on its morphological, morphometric, and molecular characters. The new species is characterised by a body length of 1040 (920-1124) μm (females) and 985 (990-1043) μm (males), lip region continuous, 7.2 (7.0-8.0) μm broad, 3.3 (3.0-4.0) μm high, stylet length 8.4 (7.0-9.0) μm or ca 1.0-1.3 times the lip region diam., lateral fields with five or six incisures, the outer incisures crenate and inner incisures weakly crenate, and excretory pore situated 156 (141-170) μm from the anterior end. The basal pharyngeal bulb has a short posterior extension projecting dorsally into the intestine. Post-uterine sac absent. Functional males common in the population, spicules 29 (28-30) μm long. Tail cylindrical with broadly rounded terminus in the female and conical, arcuate, completely enveloped by a well-developed bursa in the male. The new species is compared with two known species of the genus, B. bisulcus and B. pissodi. Molecular phylogenetic studies of the new species using partial sequences of small subunit (SSU) rDNA revealed that it forms a clade with several nematode species belonging to genera in the Sphaerularioidea, namely: Sphaerularia, Paurodontella, Nothotylenchus, and Deladenus.

Molecular control of macroscopic forces drives formation of the vertebrate hindgut.

The embryonic gut tube is a cylindrical structure from which the respiratory and gastrointestinal tracts develop1. Although the early emergence of the endoderm as an epithelial sheet2,3 and later morphogenesis of the definitive digestive and respiratory organs4-6 have been investigated, the intervening process of gut tube formation remains relatively understudied7,8. Here we investigate the molecular control of macroscopic forces underlying early morphogenesis of the gut tube in the chick embryo. The gut tube has been described as forming from two endodermal invaginations-the anterior intestinal portal (AIP) towards the rostral end of the embryo and the caudal intestinal portal (CIP) at the caudal end-that migrate towards one another, internalizing the endoderm until they meet at the yolk stalk (umbilicus in mammals)1,6. Migration of the AIP to form foregut has been descriptively characterized8,9, but the hindgut is likely to form by a distinct mechanism that has not been fully explained10. We find that the hindgut is formed by collective cell movements through a stationary CIP, rather than by movement of the CIP itself. Further, combining in vivo imaging, biophysics and mathematical modelling with molecular and embryological approaches, we identify a contractile force gradient that drives cell movements in the hindgut-forming endoderm, enabling tissue-scale posterior extension of the forming hindgut tube. The force gradient, in turn, is established in response to a morphogenic gradient of fibroblast growth factor signalling. As a result, we propose that an important positive feedback arises, whereby contracting cells draw passive cells from low to high fibroblast growth factor levels, recruiting them to contract and pull more cells into the elongating hindgut. In addition to providing insight into the early gut development, these findings illustrate how large-scale tissue level forces can be traced to developmental signals during vertebrate morphogenesis.

Anatomske varijacije pneumatizacije klinastog sinusa u vojvođanskoj populaciji

Introduction: The sphenoid sinus is considered to be morphologically one of the most variable structures in the human body. Aim: The aim of this study was to analyse the variants of pneumatisation of sphenoid bone and to determine differences in relation to the gender and body side in the population of Vojvodina. Material and methods: This retrospective study included 60 patients (30 males and 30 females), mean age 39.92 years, who underwent a CT scan of paranasal sinuses in the Center of Radiology, Clinical Center of Vojvodina, Novi Sad. The total number of analysed sinuses was 120. The CT scan images were presented in coronal, sagittal and axial planes. The types and the extensions of sinus were analysed. Results: The most common type of the sphenoid sinus was sellar (83.33%), followed by presellar (15.83%). The conchal type was found in only one case (0.83%). The most frequent subtype of the posterior extension in males was subdorsal (48%) and in females subtype body (42%). The presence of both lateral and anterior extensions was found in 18.33% cases, only lateral extension in 45% cases and only anterior in 10%. Conclusion: The most common type of sphenoid sinus was sellar, while the conchal type was the rarest one. The most frequent subtype was subdorsal in males and subtype body in females. The lateral extension was observed more often in comparison to the anterior extension.

Molecular and morphological characterization of Paurodontoides siddiqii n. sp. (Nematoda: Hexatylina, Sphaerulariidae) associated with bark samples of Pinus eldarica from western Iran.

A new species of Paurodontoides, P. siddiqii n. sp., is described and illustrated based on its morphological, morphometric, and molecular characters. The new species is characterized by a female 550-729 μm long, lip region continuous with body contour, stylet length 7.0-8.0 μm long or c. 1.0-1.2 times the lip region diameter, lateral fields with four smooth incisures, excretory pore at 85-125 μm from anterior end located at the base of the pharyngeal bulb or posterior to it, basal pharyngeal bulb with a short posterior extension projecting into the intestine, monodelphic-prodelphic reproductive system with prominent 19-22 μm long post-uterine sac, and elongate conoid tail with a filiform terminus. The new species is compared with two known species of the genus. It differs from the type species of the genus, P. linfordi, by having slightly shorter stylet, lateral field with smooth incisures, different position of the excretory pore, and absence of male. Compared to P. latus, the new species has a shorter body, shorter stylet, different position of the excretory pore, female tail shape and absence of male. The new species was also compared with close species of the genus Paurodontus because of lateral field marked with four lines, asymmetrical stylet knobs and absence of male. Molecular phylogenetic studies of the new species using partial sequences of 18S rDNA revealed that it forms a clade with a species of the genus Ficotylus. In phylogenetic analyses using partial sequences of the 28S rDNA D2-D3 domain, the new species formed a monophyletic group with a species of the genus Veleshkinema and Sphaerularia spp. (Sphaerulariinae).

Rare case of neglected large sacral Chordoma in a young female treated by wide En bloc resection and Sacrectomy

BackgroundSacral chordoma is a locally aggressive malignant tumour originating from ectopic notochordal cells. The natural history of sacral chordoma is a slow growing tumour arising at the midline of the lower sacrum that can invade the sacrum and progressively increase in size expanding cranially and anteriorly. Metastasis is very rare even when the tumour is large. Sacral chordoma affects males more than females and is more commonly found in middle age and elderly patients.Case presentationA 25 years old female had neglected an extremely large midline sacral mass for 2 years. On presentation to hospital, she had been bed bound for the past 2 years. The sacral mass was so large that it prevented her from lying down supine and sitting on the wheelchair comfortably. Clinical examination showed a 40 cm × 30 cm × 20 cm hard mass over the sacrum that involved both buttocks and the gluteal fold. Neurological exam of bilateral lower limb was normal. Computed Tomography Scan of the Pelvis showed a large destructive sacrococcygeal mass measuring 43 cm × 38 cm × 27 cm with extension into the presacral space resulting in anterior displacement of the rectum, urinary bladder and uterus; and posterior extension into the dorsal soft tissue with involvement of the gluteus, piriformis, and left erector spinae muscles. Biopsy taken confirmed Chordoma. This patient was managed by a multidisciplinary team in an Oncology referral centre. The patient had undergone Wide En Bloc Resection and Sacrectomy, a complex surgery that was associated with complications namely bleeding, surgical site infection and neurogenic bowel and bladder. Six months post operatively the patient was able to lie supine and sit on wheelchair comfortably. She required extensive rehabilitation to help her ambulate in future.ConclusionThis is a rare case of neglected sacral chordoma in a young female treated with Wide En Bloc Resection and Sacrectomy associated with complications of this complex surgery. Nevertheless, surgery is still worthwhile to improve the quality of life and to prevent complications secondary to prolonged immobilization. A multidisciplinary approach is ideal and team members need to be prepared to address the complications once they arise.