Anatomically Preserved Research Articles

An Investigation Into Whether the Facial Nerve and Auditory Nerve can be Protected by Removal of the Posterior Wall of the Internal Auditory Canal Under 30° Neuroendoscopy During Vestibular Schwannoma Surgery.

The aim of this study was to evaluate the surgical technique of microresection of vestibular schwannoma by removing the posterior wall of the internal auditory canal (IAC) under neuroelectrophysiological monitoring and 30° neuroendoscopy, with respect to the protection of facial and auditory nerve function. Forty-five cases of microscopic resection of auditory neuromas were performed through a posterior approach to the inferior occipital sigmoid sinus using a 30° neuroendoscope to assist in the removal of the posterior wall of the IAC during surgery. Patients underwent cranial enhancement magnetic resonance imaging examination and functional assessment of the facial and auditory nerves before and after surgery, and clinical data were collected for retrospective analysis. All tumors were removed in 41 patients, and most of the tumors were removed in 4 patients. The facial nerve was anatomically preserved in 43 patients (95.6%), and the percentage of facial nerve function preservation (House-Brackmann grade I-II) was 84.4%. Forty patients (88.9%) had anatomical preservation of the auditory nerve, with a 66.7% functional preservation rate. At 3 to 39 months of follow-up, 45 patients were reviewed with 3.0T-enhanced magnetic resonance imaging, and no tumor recurrence was observed in any of the patients. Microscopic resection of auditory neuroma through the posterior approach of the inferior occipital sigmoid sinus with intraoperative use of 30° neuroendoscopic assistance to abrade the posterior wall of the IAC can eliminate dead space in certain anatomical areas during surgery and minimize surgical damage to the facial and auditory nerves, which is the basis for preservation of facial and auditory nerve function.

Stem diversity of the marattialean tree fern family Psaroniaceae from the earliest Permian Wuda Tuff Flora

This paper investigates the taxonomic diversity of marattialean stems from the family Psaroniaceae preserved in-situ within the Wuda Tuff Flora. Three species of the permineralized stem Psaronius and eight species of the compression/impression stem Caulopteris are documented, but it has not been possible to associate the anatomically preserved species with the compression/impression ones due to preservational limitations. The higher diversity of Caulopteris species may relate to anatomical features that could distinguish additional species of Psaronius not being preserved, or it may reflect the rarity of anatomical preservation in the flora limiting the available dataset and it is also possible that a “generalized” Psaronius anatomy was common to several stem species showing distinct leaf scars (Caulopteris) and distinct leaves (Pecopteris). The eight species of Caulopteris recorded are very close to the previously reported diversity of nine species of the vegetative leaf Pecopteris from the Wuda flora, which also indicates a high diversity within the family. However, intraspecific variation makes the identification of species of Pecopteris and Caulopteris rather difficult, potentially inflating the taxonomic diversity of these genera. We show that Psaronius stems from the Wuda flora include one species from the Psaronius blicklei-group, one species that shares characters with both Psaronius blicklei and Psaronius panxianensis groups, and one species that shares characters with Psaronius blicklei-group but possesses a unique one different from both Psaronius blicklei and Psaronius panxianensis groups. These species appear to represent transitional forms evolved from the Carboniferous–Cisuralian (early Permian) Psaronius blicklei-group that are on the evolutionary lineage leading to the Lopingian (late Permian) Psaronius panxianensis-group. In addition, a single occurrence of a stem of Psaronius in organic attachment to a tri-pinnate frond of Pecopteris orientalis (Schenk) Pot. is documented, representing an important starting point for future Psaroniaceae whole-plant reconstructions within the Cathaysian flora.

Anatomical preservation of silicified Corylites J.S.Gardner leaves from the Paleocene maar lake of Menat (Puy-de-Dôme, France)

Uhl D., Jasper A. & Wuttke M. 2020. — Anatomical preservation of silicified corylites J.S.Gardner leaves from the Paleocene maar lake of Menat (Puy-de-Dôme, France). geodiversitas 42 (26): 485-492. http://geodiversitas.com/42/26The late Paleocene fossil lagerstätte Menat in France is well known for its wealth of excellently preserved fossil plants and insects. Although the flora from this locality is regarded as characteristic for the late Thanetian in Western and Central Europe, there is a noteworthy lack of modern paleobotanical studies on this locality. The few existing studies on plant megafossils utilized only the gross morphology of leaves and carpological material for taxonomic questions, whereas anatomical data (i.e. from cuticles and permineralizations) have been completely neglected. The present study provides the first data on anatomically preserved internal tissues of leaves assigned to Corylites macquarrii (Forbes) Heer from this locality. Cell walls are preserved as silicates, whereas cell lumina are mostly empty. On occasion, cell lumina are filled with foam-like, porous silica. Anatomical preservation of these tissues is probably related to early diagenetic silicification of plant cell walls. Although at the moment nothing can be said about the source of the SiO2 it is likely that it is related to the volcanic origin of the Menat maar and/or volcanic activities in the vicinity of the lake during deposition of the sediments.

Classification and surgical strategy of Work Ⅰ congenital first branchial cleft anomaly based on adjacent anatomy

Objective:To explore the adjacent anatomic relationship and classification of Work Ⅰ congenital first branchial cleft anomaly（CFBCA） in order to guide clinical practice. Method:The data of 48 cases of Work Ⅰ CFBCA with complete data were analyzed retrospectively. Result:All 48 lesions were completely resected. 48 sides（100.0%） were anatomically preserved facial nerve, partial parotidectomy was performed on 33 sides（68.8%）, superficial lobe+deep lobe partial parotidectomy was performed on 9 sides（18.8%）, and 6 sides（12.5%） was not performed parotidectomy. External auditory canal reconstruction was performed on 32 sides（66.7%）; 43 sides（89.6%） underwent the anatomical preservation of the auricular lobe branch of the great auricular nerve; 9 sides（18.8%） was performed selective cervical lymphadenectomy at the same time. 45 sides of Work Ⅰ CFBCA presented irregular cystic or lobulated structure, the lesion was located below and behind the junction of the external auditory meatus bone and cartilage and distributed along the longitudinal axis of the external auditory canal; 3 sides were isolated in superficial lobe parenchyma of parotid gland. All lesions were located on the superficial surface of the main trunk and branches of the facial nerve. The average value of the shortest vertical distance between the lower edge of the lesion and the outlet of the main trunk of the facial nerve at the stylomastoid foramen was 7.2 （0-13.4 ）mm. Based on preoperative images and intraoperative findings, according to the adjacent relation with external auditory meatus , parotid gland and facial nerve, the classification of Work Ⅰ congenital first branchial cleft anomaly is proposed, which is specifically divided into 4 types: C1（posterior wall of the external auditory meatus） 17 cases（35.4%）, C2（inferior wall of the external auditory meatus） 13 cases（27.1%）, C3 （multi wall of the external auditory meatus） 15 cases（31.3%）, C4（isolated from parotid gland parenchyma） 3 cases（6.3%）. Conclusion:Work Ⅰ CFBCA has a close relationship with the adjacent anatomy of the region, and familiar with the classification of Work Ⅰ congenital first branchial cleft anomaly is helpful for the treatment of type and accurate resection.

A new anatomically preserved Alloiopteris fern from Moscovian (Bolsovian) volcanoclastics of Flöha (Flöha Basin, SE Germany)

The morphology and anatomy of a new zygopterid fern are described from the Middle Pennsylvanian (Bolsovian) of Floha, SE Germany. The fossils occur as allochthonous remains within the basal Schweddey Ignimbrite, which preserves a diverse wetland plant community of cordaitaleans, ferns, pteridosperms, calamitaleans, and lycophytes. Pinnae of Alloiopteris loecsei sp. nov. exhibit a combined carbonized and anatomical preservation type due to rapid entombment in fine-grained pyroclastics. The newly collected Alloiopteris fossils show typical gross morphology, but also reveal the anatomy of penultimate and ultimate rachides. The affinity of the new fern is discussed amongst zygopterids in general and the famous zygopterid stems Zygopteris primaria (von Cotta) Corda and Asterochlaena laxa Stenzel from the Floha site in particular. Our investigation highlights the striking potential of pyroclastic deposits for preserving and yielding both morphological and three-dimensional anatomical aspects of plant fossils.

The anatomy of the perineal branch of the sciatic nerve.

A "perineal" branch of the sciatic nerve has been visualized during surgery, but there is currently no description of this nerve branch in the literature. Our study investigates the presence and frequency of occurrence of perineal innervation by the sciatic nerve and characterizes its anatomy in the posterior thigh. Fifteen cadavers were obtained for dissection. Descriptive results were recorded and analyzed statistically. Twenty-one sciatic nerves were adequately anatomically preserved. Six sciatic nerves contained a perineal branch. Five sciatic nerves had a branch contributing to the perineal branch of the posterior femoral cutaneous (PFC) nerve. In specimens with adequate anatomical preservation, the perineal branch of the sciatic nerve passed posterior to the ischial tuberosity in three specimens and posterior to the conjoint tendon of the long head of biceps femoris and semitendinosus muscles (conjoint tendon) in one. In specimens in which the perineal branch of the PFC nerve received a contribution from the sciatic nerve, the branch passed posterior to the sacrotuberous ligament in one case and posterior to the conjoint tendon in three. Unilateral nerve anatomy was found to be a poor predictor of contralateral anatomy (Cohen's kappa = 0.06). Our study demonstrates for the first time the presence and frequency of occurrence of the perineal branch of the sciatic nerve and a sciatic contribution to the perineal branch of the PFC nerve. Clinicians should be cognizant of this nerve and its varying anatomy so their practice is better informed. Clin. Anat. 31:357-363, 2018. © 2018 Wiley Periodicals, Inc.

Facial Nerve Function and Quality of Resection in Large and Giant Vestibular Schwannomas Surgery Operated By Retrosigmoid Transmeatal Approach in Semi-sitting Position with Intraoperative Facial Nerve Monitoring.

Large and giant vestibular schwannomas pose a real problem in their management. The preservation of facial nerve function may limit tumor resection despite the use of intraoperative monitoring of the facial nerve. In Algeria, vestibular schwannomas represent 5% of all intracranial tumors operated on, 80.5% of which are large or giant. From January 2010 to December 2015, 151 large and giant vestibular schwannomas were operated in our department. Tumor diameter was between 30 and 60mm. The most common presenting symptom was hearing loss, which was observed in 41.66% of all our patients. All patients were operated in the semi-sitting position with opening of the posterior wall of the internal auditory canal and under continuous intraoperative facial nerve function monitoring. Tumor resection was total in 126 patients. Anatomic preservation of the facial nerve was the reason for nontotal resection in 25 patients. The facial nerve was anatomically preserved in 149 patients. Two years after surgery, the facial nerve function was grade I-II House-Brackmann (H-B) score in 124 cases (82%),grade III-IV H-B score in 21 cases (14%), and grade V-VI H-B score in 06 cases (04%). The status and the improvement of postoperative facial nerve function depend on 4 factors: anatomic preservation of nerve,stimulation threshold, cystic form, and the presence of train activity. The development of anesthesia techniques and microsurgery and the systematic use of intraoperative monitoring of the facial nerve have allowed us to move from a life preservation era to another era of preservation of function.

Anatomically preserved "strobili" and leaves from the Permian of China (Dorsalistachyaceae, fam. nov.) broaden knowledge of Noeggerathiales and constrain their possible taxonomic affinities.

Noeggerathiales are an extinct group of heterosporous shrubs and trees that were widespread and diverse during the Pennsylvanian-Permian Epochs (323-252 Ma) but are of controversial taxonomic affinity. Groups proposed as close relatives include leptosporangiate ferns, sphenopsids, progymnosperms, or the extant eusporangiate fern Tmesipteris. Previously identified noeggerathialeans lacked anatomical preservation, limiting taxonomic comparisons to their external morphology and spore structure. We here document from the upper Permian of China the first anatomically preserved noeggerathialeans, which enhance the perceived distinctiveness of the group and better indicate its systematic affinity. We describe in detail the newly discovered, anatomically preserved heterosporous strobilus Dorsalistachya quadrisegmentorum, gen. et sp. nov., and redescribe its suspected foliar correlate, the pinnate leaf Plagiozamites oblongifolius. Plagiozamites possesses an omega (Ω)-shaped vascular trace and prominent cortical secretory cavities-a distinctive anatomical organization that is echoed in the newly discovered strobili. Dorsalistachya strobili bear highly dissected sporophylls alternately in two vertical rows, suggesting that they are homologs of leaf pinnae. If so, the "strobilus" is strictly a pseudostrobilus and consists of sporangium-bearing units that are one hierarchical level below true sporophylls. The "sporophylls" bear four microsporangia on the lower (abaxial) surface, occasionally interspersed with short longitudinal rows of megasporangia. A single functional megaspore develops within each winged megasporangium, suggesting adaptation for dispersal as a single unit. Dorsalistachya presents a unique combination of reproductive features that amply justifies establishment of a new family, Dorsalistachyaceae. Noeggerathiales represent a distinct taxonomic Order of free-sporing plants that most resembles early-divergent eusporangiate ferns and the more derived among the extinct progymnosperms. By the early Permian, noeggerathialeans had attained levels of reproductive sophistication similar to the most derived among the Paleozoic sphenophytes and lycophytes, but their heterosporous life history may have contributed to their extinction during the Triassic climatic aridification.

Exploring the fossil history of pleurocarpous mosses: Tricostaceae fam. nov. from the Cretaceous of Vancouver Island, Canada.

Mosses, very diverse in modern ecosystems, are currently underrepresented in the fossil record. For the pre-Cenozoic, fossil mosses are known almost exclusively from compression fossils, while anatomical preservation, which is much more taxonomically informative, is rare. The Lower Cretaceous of Vancouver Island (British Columbia, Canada) hosts a diverse anatomically preserved flora at Apple Bay. While the vascular plant component of the Apple Bay flora has received much attention, the numerous bryophytes identified at the locality have yet to be characterized. Fossil moss gametophytes in more than 20 carbonate concretions collected from the Apple Bay locality on Vancouver Island were studied in serial sections prepared using the cellulose acetate peel technique. We describe Tricosta plicata gen. et sp. nov., a pleurocarpous moss with much-branched gametophytes, tricostate plicate leaves, rhizoid-bearing bases, and delicate gametangia (antheridia and archegonia) borne on specialized branches. A new family of hypnanaean mosses, Tricostaceae fam. nov., is recognized based on the novel combination of characters of T. plicata. Tricosta plicata reveals pleurocarpous moss diversity unaccounted for in extant floras. This new moss adds the first bryophyte component to an already diverse assemblage of vascular plants described from the Early Cretaceous at Apple Bay and, as the oldest representative of the Hypnanae, provides a hard minimum age for the group (136 Ma).

Fruits of Icacinaceae (Tribe Iodeae) from the Late Paleocene of western North America

The Icacinaceae occur pantropically today, but are well represented by fossil fruits of the warm Early Middle Eocene, when tropical plants that currently occupy low latitudes were more widely distributed in higher latitudes. Members of this family are first known in the Late Cretaceous; however, fossil fruits of tribe Iodeae are quite rare before the Eocene. In this paper we describe the first formally recognized Late Paleocene icacinaceous taxa from western North America. We name two new species of Icacinicarya based on anatomically preserved fruits and establish a new genus, Icacinicaryites, for impressions with a strong similarity to Icacinicarya that lack anatomical preservation. These new records from the Almont/Beicegel Creek flora in North Dakota and several localities in Wyoming, Colorado, and Montana complement records known from the Early Eocene of England and document an increased diversity of Iodeae and related forms in the Paleogene of western North America.

Systematics, Ontogeny, and Phylogenetic Implications of Exceptional Anatomically Preserved Cycadophyte Leaves from the Middle Jurassic of Bearreraig Bay, Skye, Northwest Scotland

The Middle Jurassic (Aalenian-Bajocian) shallow marine deposits of Bearreraig Bay, Skye, northwest Scotland, have yielded calcite-permineralized leaves of cycadophytes showing unusually well preserved anatomy. Morphological characters identify the leaves asNilssonia cf.tenuinervis Seward (Cycadales),Otozamites mortonii sp. nov. (Bennettitales), a putative juvenile leaf showing imbricate, recurved pinnae, andOtozamites sp. Permineralized Jurassic cycadophytes occur in only four other localities worldwide; the better-known coeval adpression flora of Yorkshire lacks anatomical preservation. Past studies of fossil cycadophyte species have therefore emphasized morphology, whereas the Skye specimens reveal details of anatomy greatly exceeding published descriptions of similar species. The arrangement of vascular tissues in the rachis ofOtozamites resembles that described forPtilophyllum cutchense Morris (Bennettitales) from India. Stomata observed in the preserved cuticle of theNilssonia leaf superficially resemble those of the extant cycadMacrozamia Miquel. Given the 180 million years separating these two genera, and the fragmentary preservation and equivocal phylogenetic position ofNilssonia, comparative interpretations remain tentative. Leaf characters have been little used in phylogenetic analyses, reflecting exaggerated fears of anatomical and morphological convergence; these characters therefore require particular attention when comparing fossil cycadophytes with their living relatives.

Facial Nerve Outcome after Acoustic Neuroma Surgery: A Study from the Era of Cranial Nerve Monitoring

The introduction of intraoperative cranial nerve monitoring in posterior fossa surgery has greatly aided the surgeon in identification and anatomic preservation of cranial nerves. As a result, the long-term function of the facial nerve continues to improve after removal of acoustic neuroma. Herein, we report our long-term (1 year or greater) facial nerve outcome in 129 patients who underwent surgical removal of their acoustic neuromas with the aid of intraoperative neurophysiologic monitoring between 1986 and 1990. The facial nerve was anatomically preserved in 99.2% of the patients, and 90% of all the patients had grade 1 or 2 facial nerve function 1 year after surgery. Long-term facial function was inversely correlated with the size of tumor (chi-squared, p < 0.02) and was not related to the side of tumor, the age and sex of the patient, or the surgical approach. In a comparison among tumor groups matched for size, no statistically significant difference in facial nerve outcome between the translabyrinthine and retrosigmoid approaches was detected. The proximal facial nerve stimulation threshold at the end of surgical removal was predictive of long-term facial nerve function (analysis of variance, p < 0.02). At 1 year, 98% (87 of 89) of the patients with electrical thresholds of 0.2 V or less had grade 1 or 2 facial nerve function compared with only 50% (8 of 16) of those with thresholds between 0.21 and 0.6 V. In the era of cranial nerve monitoring, patients can be better advised about long-term facial nerve outcome after surgical intervention. Preoperatively, the size of the tumor is the most critical factor in predicting long-term facial function. Postoperatively, the proximal seventh nerve stimulation threshold at the end of the surgical procedure can be used as one prognostic measure of long-term facial nerve function.

Facial nerve function after surgery for removal of acoustic neuroma by the extended middle cranial fossa approach.

Postoperative facial nerve function was evaluated in 98 patients operated on by the middle cranial fossa approach or the extended middle cranial fossa approach from June 1976 to April 1985. In this series, the smaller the tumor size at the time of the initial surgery, the better the postoperative facial nerve function was. The facial nerve was preserved in 83.4% of the 79 patients who were subjected only to the initial surgery. However, total removal of the tumor along with facial nerve preservation was achieved only in 70.8%. Anatomical preservation of the facial nerve was possible in 78% of 87 patients. The postoperative functional results among patients in whom facial nerves were anatomically preserved were satisfactory (facial expression score of 75% or higher, i.e., 30 points or more out of a possible 40 points) in 70-80% of the patients with small size or intracanalicular tumors, but, in less than 50% of the patients with tumors of medium size or larger. There is a need to obtain higher rates of functional preservation as well as higher rates of satisfactory functional results. At the present stage, we must strive to achieve earlier diagnosis so that surgery can be performed while the tumor is still medium-sized or small.

Anatomically preserved plants from the Middle Eocene (Allenby Formation) of British Columbia

Well preserved, permineralized plant material from the Middle Eocene, Allenby Formation of British Columbia provides the basis for this description of an extensive Tertiary flora. The flora comprises a diverse assemblage of abundant plant remains in a chert matrix which outcrops south of Princeton, B.C., Canada. Preliminary examination of this material reveals numerous fertile and vegetative organs of angiosperms, conifers, ferns, bryophytes, and fungi, most of which represent presently unknown taxa. Initial studies indicate that we are dealing with the most diverse Eocene permineralization flora ever discovered. Superb anatomical preservation, including developmental stages of various organs, characterize many of the taxa and promise to significantly increase our knowledge of early Tertiary plants.