A new concept in Dorello's canal microanatomy: the petroclival venous confluence

1997 ◽  
Vol 87 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Christophe Destrieux ◽  
Stéphane Velut ◽  
Médard K. Kakou ◽  
Thierry Lefrancq ◽  
Brigitte Arbeille ◽  
...  
Keyword(s):  
Dura Mater ◽  
Transverse Section ◽  
Sagittal Plane ◽  
Venous Blood ◽  
Vertical Plane ◽  
Petrous Bone ◽  
Inferior Petrosal Sinus ◽  
Content Type ◽  
Dorello’S Canal ◽  
Abducent Nerve

✓ The so-called Dorello's canal was studied in 32 specimens (16 human cadaver heads) injected with colored latex and fixed in formalin (28 specimens) or studied with microscopic and ultrastructural methods (four specimens). To avoid the differences usually encountered in the description of this area, the authors preferred to consider a larger space that they have named the petroclival venous confluence (PVC). It was located between two dural layers: inner (or cerebral) and outer (or osteoperiosteal). The PVC was quadrangular on transverse section. The posterior petroclinoid fold and the axial plane below the dural foramen of the abducent nerve (sixth cranial nerve) limited the PVC at the top and bottom, respectively. Its anteroinferior limit was the posterosuperior aspect of the upper clivus and outer layer of the dura mater. Its anterior limit was the vertical plane containing the posterior petroclinoid fold, and its posterior limit was the inner layer of the dura. The PVC was limited laterally by the medial aspect of the petrous bone apex and medially by the virtual sagittal plane extending the medial limit of the inferior petrosal sinus upward. The PVC was a venous space bordered by endothelium and continuous with the cavernous sinus, the basal sinus of the clivus, and the inferior petrosal sinus. There were trabeculations between the two dural layers. The petrosphenoidal ligament of Grüber may be regarded as a larger trabeculation, and it divided the PVC into a superior and an inferior compartment. The abducent nerve generally ran through the inferior compartment, where it was fixed to the surrounding dura mater. This nerve was only separated from venous blood by a meningeal sheath of varying thinness lined with endothelium. The clinical implications of these findings are discussed.

Usefulness of inferior petrosal sinus venous endocrine markers in Cushing's disease

1988 ◽  
Vol 68 (2) ◽  
pp. 205-210 ◽  
Author(s):  
John Zovickian ◽  
Edward H. Oldfield ◽  
John L. Doppman ◽  
Gordon B. Cutler ◽  
D. Lynn Loriaux
Keyword(s):  
Cushing’S Disease ◽  
Venous Blood ◽  
Pituitary Hormones ◽  
Cushing's Disease ◽  
Ectopic Acth Syndrome ◽  
Inferior Petrosal Sinus ◽  
Ectopic Acth ◽  
Content Type ◽  
Acth Secreting ◽  
Fine Print

✓ Bilateral and simultaneous sampling of the inferior petrosal sinuses in patients with Cushing's disease has been used to establish the presence and laterality of adrenocorticotropic hormone (ACTH)-producing microad-enomas prior to transsphenoidal surgery. Successful preoperative lateralization depends upon equivalent dilution of pituitary venous blood on the two sides since samples which are diluted by unequal amounts of non-pituitary blood may lead to erroneous results. To assure valid sampling results, the use of other pituitary hormones, measured simultaneously, has been proposed to correct the ACTH concentrations from the inferior petrosal sinuses against unequal dilution by non-pituitary venous blood. This proposal presumes that ACTH-secreting microadenomas will not cause unequal delivery of the other pituitary hormones into the two inferior petrosal sinuses. The inferior petrosal sinus concentrations of prolactin (PRL), thyrotropin (TSH), and the alpha subunit of human chorionic gonadotropin (α-HCG) were evaluated as indicators of pituitary venous blood dilution in 11 patients with Cushing's disease. Four patients with ectopic ACTH syndrome served as controls. Blood was withdrawn simultaneously from catheters in both inferior petrosal sinuses and from a peripheral vein for measurement of ACTH, PRL, TSH, and α-HCG. The ACTH concentrations were then corrected for dilution by non-pituitary blood by dividing the ACTH concentration from each side by the ratio of the inferior petrosal sinus to peripheral blood concentrations of PRL, TSH, and α-HCG for that side. At surgery, all 11 patients had ACTH-secreting microadenomas on the side predicted by the uncorrected ACTH concentrations. However, in three patients the corrected ACTH values would have led to erroneous results. Among the 18 sets of corrected inferior petrosal sinus measurements in these three patients, the corrected ACTH values failed to show an inferior petrosal sinus gradient in six and localized the tumor to the side opposite the adenoma in four. Incorrect lateralization was obtained with each of the hormones (PRL, TSH, and α-HCG) used for correction. Furthermore, the ipsilateral (side of tumor)-to-contralateral inferior petrosal sinus gradient of ACTH in patients with Cushing's disease was generally paralleled by a significant inferior petrosal sinus gradient of PRL, TSH, and α-HCG to the side of the tumor, whereas patients with the ectopic ACTH syndrome tended not to exhibit lateralizing (side-to-side) gradients. These findings indicate that the simultaneous measurement of inferior petrosal sinus concentrations of PRL or TSH or of the glycoprotein hormone α subunit does not improve preoperative localization of ACTH-secreting microadenomas and may lead to incorrect lateralization of the tumor. The results also suggest that ACTH-secreting microadenomas cause enhanced delivery of PRL, TSH, and α subunit into the inferior petrosal sinus ipsilateral to the tumor which, in turn, may reflect paracrine stimulation of hormone secretion in the anterior pituitary gland surrounding ACTH-secreting microadenomas.

Dorello's canal: a microanatomical study

1991 ◽  
Vol 75 (2) ◽  
pp. 294-298 ◽  
Author(s):  
Felix Umansky ◽  
Josef Elidan ◽  
Alberto Valarezo
Keyword(s):  
Cranial Nerve ◽  
Venous Blood ◽  
Abducens Nerve ◽  
Microsurgical Anatomy ◽  
Sixth Cranial Nerve ◽  
Content Type ◽  
Dorello’S Canal ◽  
Pathological Conditions ◽  
Anatomical Relationship ◽  
Fine Print

✓ The microsurgical anatomy of Dorello's canal has been studied in 20 specimens obtained from 10 cadaver heads fixed in formalin. The bow-shaped canal through which courses the abducens nerve before reaching the cavernous sinus is located inside a venous confluence which occupies the space between the dural leaves of the petroclival area. The petrosphenoidal ligament (Gruber's ligament), which forms the posteromedial wall of the canal, appears as a fibrous trabecula surrounded by venous blood. Canal measurements were performed and its anatomical relationship with the sixth cranial nerve is described. Angulations of variable degrees were observed in the course of the nerve inside and outside the canal. The influence of this relatively tortuous course of the abducens nerve upon its vulnerability in some pathological conditions is discussed.

Detailed magnetic resonance imaging anatomy of the cisternal segment of the abducent nerve: Dorello's canal and neurovascular relationships and landmarks

1999 ◽  
Vol 91 (2) ◽  
pp. 276-283 ◽  
Author(s):  
Indra Yousry ◽  
Salvador Camelio ◽  
Martin Wiesmann ◽  
Urs D. Schmid ◽  
Bernhard Moriggl ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Three Dimensional ◽  
Anterior Inferior Cerebellar Artery ◽  
Content Type ◽  
Dorello’S Canal ◽  
Imaging Sequence ◽  
Cerebellar Artery ◽  
Abducent Nerve ◽  
Fine Print

Object. The goal of this study was to identify reliably the cisternal segment of the abducent nerve by using the three-dimensional Fourier transform constructive interference in steady-state (3-D CISS) magnetic resonance (MR) imaging sequence to define landmarks that assist in the identification of the abducent nerve on MR imaging and to describe the nerve's relationship to the anterior inferior cerebellar artery (AICA).Methods. A total of 26 volunteers underwent 3-D CISS MR imaging, and 10 of these volunteers also underwent MR angiography in which a time-of-flight sequence was used to identify the facial colliculus, the abducent nerve and its apparent origin, Dorello's canal, and the AICA.The authors identified the abducent nerve with certainty in 96% of 3-D CISS sequences obtained in the axial and sagittal planes and in 94% obtained in the coronal plane. The nerve emerged from the pontomedullary sulcus in 94% of cases. The facial colliculus could always be identified, and Dorello's canal was identified in 94% of cases. In 76.6% of cases, the abducent nerve was seen to contact the AICA, which passed inferior to the nerve in 63.8% of cases and superior to it in 29.8%.Conclusions. The anatomical course of the abducent nerve and its relationship to the AICA and other blood vessels can be reliably identified using a 3-D CISS MR sequence with the facial colliculus and Dorello's canal serving as landmarks.

scholarly journals Gruber, Gradenigo, Dorello, and Vail: key personalities in the historical evolution and modern-day understanding of Dorello’s canal

2016 ◽  
Vol 124 (1) ◽  
pp. 224-233 ◽  
Author(s):  
Renuka K. Reddy ◽  
Rohit K. Reddy ◽  
Robert W. Jyung ◽  
Jean Anderson Eloy ◽  
James K. Liu
Keyword(s):  
Middle Ear ◽  
English Language ◽  
Critical Role ◽  
Petrous Bone ◽  
Dorello’S Canal ◽  
Gradenigo’S Syndrome ◽  
Abducent Nerve Palsy ◽  
Ear Infections ◽  
Abducent Nerve ◽  
Petrous Apicitis

A century ago an ambitious young anatomist in Rome, Primo Dorello, who sought to understand the cause of abducent nerve palsy that often occurred in patients with severe middle ear infections, conducted intricate studies on the intracranial course of the nerve. In his findings, he identified that the abducent nerve passes through a narrow sinus near the apex of the petrous bone, which formed an osteofibrous canal. Dorello suggested that in this enclosed region the abducent nerve may be particularly vulnerable to compression due to the vascular edema accompanying the infection. Although his work was widely appreciated, it was not well received by all. Interestingly, Giuseppe Gradenigo, one of the most prominent Italian otologists of the early 20th century, who was known for his work on a triad of symptoms (Gradenigo’s syndrome) that accompanies petrous apicitis, a result of severe middle ear infections, was obstinate in his criticism of Dorello’s findings. Thus a scientific duel began, with a series of correspondence between these two academics—one who was relatively new to the otological community (Dorello) and one who was well reputed in that community (Gradenigo). The disagreement ultimately ebbed in 1909, when Dorello published a report in response to Gradenigo’s criticisms and convinced Gradenigo to change his views. Today Dorello’s canal is widely recognized as a key landmark in skull base surgery of the petroclival region and holds clinical significance due to its relation to the abducent nerve and surrounding vascular structures. Yet, although academics such as Dorello and Gradenigo are recognized for their work on the canal, it is important not to forget the others throughout history who have contributed to the modern-day understanding of this anatomical structure. In fact, although the level of anatomical detail found in Dorello’s work was previously unmatched, the first description of the canal was made by the experienced Austrian anatomist Wenzel Leopold Gruber in 1859, almost 50 years prior to Dorello’s landmark publication. Another critical figure in building the understanding of Dorello’s canal was Harris Holmes Vail, a young otolaryngologist from Harvard Medical School, who in 1922 became the first person to describe Dorello’s canal in the English language. Vail conducted his own detailed anatomical studies on cadavers, and his publication not only reaffirmed Dorello’s findings but also immortalized the eponym used today—“Dorello’s canal.” In this article the authors review the life and contributions of Gruber, Dorello, Gradenigo, and Vail, four men who played a critical role in the discovery of Dorello’s canal and paved the way toward the current understanding of the canal as a key clinical and surgical entity.

Superior sagittal sinus thrombosis induced by thyrotoxicosis

2001 ◽  
Vol 94 (1) ◽  
pp. 130-132 ◽  
Author(s):  
Cheng-Shyuan Rau ◽  
Chun-Chung Lui ◽  
Cheng-Loong Liang ◽  
Han-Jung Chen ◽  
Yeh-Lin Kuo ◽  
...  
Keyword(s):  
Intracranial Hemorrhage ◽  
Superior Sagittal Sinus ◽  
Sinus Thrombosis ◽  
Venous Blood ◽  
Fibrinogen Concentration ◽  
Venous Blood Flow ◽  
Content Type ◽  
Sagittal Sinus ◽  
Low Protein ◽  
Diffuse Goiter

✓ There is a wide variety of disorders associated with thrombosis of the superior sagittal sinus (SSS), including infectious disease, noninfectious conditions such as vasculitis and hypercoagulable states, and complications arising from pregnancy or use of oral contraceptive medications. Despite these well-defined associations, approximately 25% of the cases remain idiopathic. In this article the authors describe a patient who was found to have SSS thrombosis while experiencing a thyrotoxic phase of Graves disease. The patient presented with intracerebral hemorrhage, subarachnoid hemorrhage, seizure, coma, a raised fibrinogen concentration, low protein C activity, and atrial fibrillations. Thrombolysis was successfully performed despite the coexistence of thrombosis and intracranial hemorrhage. Patients with thyrotoxicosis and a diffuse goiter may be predisposed to the development of SSS thrombosis, as a result of hypercoagulation and stasis of local venous blood flow. In the present case, a patient in whom thrombosis coexisted with intracranial hemorrhage was successfully treated using thrombolytic therapy.

En bloc petrosectomy using a Gigli saw for petroclival lesions

1995 ◽  
Vol 83 (3) ◽  
pp. 559-560 ◽  
Author(s):  
Tomio Sasaki ◽  
Makoto Taniguchi ◽  
Ichiro Suzuki ◽  
Takaaki Kirino
Keyword(s):  
Facial Nerve ◽  
Semicircular Canals ◽  
Petrous Bone ◽  
New Technique ◽  
En Bloc ◽  
Content Type ◽  
A New Technique ◽  
Transtentorial Approach ◽  
Fine Print

✓ The authors report a new technique for en bloc petrosectomy using a Gigli saw as an alternative to drilling the petrous bone in the combined supra- and infratentorial approach or the transpetrosal—transtentorial approach. It is simple and easy and avoids postoperative cosmetic deformity. This technique has been performed in 11 petroclival lesions without injuring the semicircular canals, the cochlea, or the facial nerve.

Advanced aircraft performance analysis

2018 ◽  
Vol 90 (4) ◽  
pp. 627-638 ◽  
Author(s):  
Marc Immer ◽  
Philipp Georg Juretzko
Keyword(s):  
Performance Analysis ◽  
Design Process ◽  
Performance Optimization ◽  
Electric Propulsion ◽  
Vertical Plane ◽  
Aircraft Design ◽  
Efficient Design ◽  
Content Type ◽  
Aircraft Performance ◽  
Hybrid Electric

Purpose The preliminary aircraft design process comprises multiple disciplines. During performance analysis, parameters of the design mission have to be optimized. Mission performance optimization is often challenging, especially for complex mission profiles (e.g. for unmanned aerial vehicles [UAVs]) or hybrid-electric propulsion. Therefore, the purpose of this study is to find a methodology that supports aircraft performance analysis and that is applicable to complex profiles and to novel designs. Design/methodology/approach As its core element, the developed method uses a computationally efficient C++ software “Aircraft Performance Program” (APP), which performs a segment-based mission computation. APP performs a time integration of the equations of motion of a point mass in the vertical plane. APP is called via a command line interface from a flexible scripting language (Python). On top of APP’s internal radius of action optimization, state-of-the-art optimization packages (SciPy) are used. Findings The application of the method to a conventional climb schedule shows that the definition of the top of climb has a significant influence on the resulting optimum. Application of the method to a complex UAV mission optimization, which included maximizing the radius of action, was successful. Low computation time enables to perform large parametric studies. This greatly improves the interpretation of the results. Research limitations/implications The scope of the paper is limited to the methodology that allows for advanced performance analysis at the conceptual and preliminary design stages with an emphasis on novel propulsion concepts. The methodology is developed using existing, validated methods, and therefore, this paper does not contain comprehensive validation. Other disciplines, such as cost analysis, life-cycle assessment or market analysis, are not considered. Practical implications With the proposed method, it is possible to obtain not only the desired optimum mission performance but also off-design performance of the investigated design. A thorough analysis of the mission performance provides insight into the design’s capabilities and shortcomings, ultimately aiding in obtaining a more efficient design. Originality/value Recent developments in the area of hybrid or hybrid-electric propulsion systems have shown the need for performance computation tools aiding the related design process. The presented method is especially valuable when novel design concepts with complex mission profiles are investigated.

Surgical treatment of the retethered spinal cord after repair of lipomyelomeningocele

1991 ◽  
Vol 74 (5) ◽  
pp. 709-714 ◽  
Author(s):  
Hiroaki Sakamoto ◽  
Akira Hakuba ◽  
Ken Fujitani ◽  
Shuro Nishimura
Keyword(s):  
Spinal Cord ◽  
Dura Mater ◽  
Conus Medullaris ◽  
Posterior Arch ◽  
Pia Mater ◽  
Dense Adhesion ◽  
Content Type ◽  
Dural Sac ◽  
Long Term Observation

✓ In a series of 75 patients with surgically treated lipomyelomeningoceles, the neurological condition of six patients deteriorated 6 months to 14 years after the operation due to repeat tethering of the spinal cord. The tethering resulted from postoperative dense adhesion between the cord and the overlying dura mater. Two of the six patients underwent conventional repeat untethering procedures, and the remaining four were successfully treated with a new surgical technique developed by the authors to prevent such dural adhesion. For this procedure, after complete untethering of the spinal cord, the lumbosacral cord is retained in the center of the dural sac by fine stay sutures between the pia mater of the conus medullaris and the ventral dura mater. In addition, the dura mater is tacked to the posterior arch which is reconstructed with bone grafts at one or two bifid vertebral levels. During a postoperative follow-up period of 1 to 3 years, no further deterioration has been observed and magnetic resonance studies have demonstrated a space filled with cerebrospinal fluid (CSF) around the lumbosacral cord. The authors conclude that long-term observation, both neurological and radiological, is essential even after successful repair of a lipomyelomeningocele. This new surgical procedure can maintain a CSF bath around the lumbosacral cord, thus preventing dural adhesion. Application of this technique will hopefully be beneficial in lipomyelomeningocele patients with a high risk of cord retethering after initial repair.

Posterior petrous meningiomas: 82 cases

2005 ◽  
Vol 102 (2) ◽  
pp. 284-289 ◽  
Author(s):  
Zhe Bao Wu ◽  
Chun Jiang Yu ◽  
Shu Sen Guan
Keyword(s):  
Facial Nerve ◽  
Clinical Manifestations ◽  
Petrous Bone ◽  
Type I ◽  
Type Ii ◽  
Posterior Surface ◽  
Total Resection ◽  
Content Type ◽  
Functional Preservation ◽  
Fine Print

Object. The aim of this study was to discuss posterior petrous meningiomas—their classification, clinical manifestations, surgical treatments, and patient outcomes. Methods. A retrospective analysis was performed in 82 patients with posterior petrous meningiomas for microsurgery. According to the anatomical relationship with the posterior surface of the petrous bone and with special reference to the internal auditory canal (IAC), posterior petrous meningiomas were classified into three types: Type I, located laterally to the IAC (28 cases); Type II, located medially to the IAC, which might extend to the cavernous sinus and clivus (32 cases); and Type III, extensively attached to the posterior surface of the petrous bone, which might envelop the seventh and eighth cranial nerves (22 cases). Sixty-eight (83%) of 82 cases involved total resection. The rate of anatomical preservation of facial nerve was 97.5%, whereas the functional preservation rate was 81%. The rate of hearing preservation was 67%. All Type I tumors were completely resected, and the rate of anatomical preservation of facial nerve was 100% and functional preservation was 93%. Regarding Type II lesions, 75% of 32 cases involved total resection; the rate of anatomical preservation of facial nerve was 97% and functional preservation was 75%. For Type III lesions, 73% of 22 cases were totally resected. The rate of anatomical preservation of facial nerve in patients with this tumor type was 95%, whereas functional preservation was 73%. Conclusions. Clinical manifestations and surgical prognoses are different among the various types of posterior petrous meningiomas. It is more difficult for Types II and III tumors to be resected radically than Type I lesions, and postoperative functional outcomes are significantly worse accordingly. The primary principles in dealing with this disease entity include preservation of vital vascular and central nervous system structures and total resection of the tumor as much as possible.

Brain and bone scans in primary Ewing's sarcoma of the petrous bone

1976 ◽  
Vol 44 (5) ◽  
pp. 608-612 ◽  
Author(s):  
Pete M. Fitzer ◽  
William R. Steffey
Keyword(s):  
Bone Scan ◽  
Ewing’S Sarcoma ◽  
Ewing's Sarcoma ◽  
Petrous Bone ◽  
Diagnosis And Treatment ◽  
Content Type ◽  
Brain Scan ◽  
Bone Scans ◽  
The Right ◽  
Fine Print

✓ The authors present a case in which primary Ewing's sarcoma of the right petrous pyramid in a 9-year-old girl showed no uptake on a 99mTc-pertechnetate nuclide angiogram. Intense uptake was present on a 99mTc-polyphosphate bone scan, but a static brain scan was only minimally abnormal. The diagnosis and treatment of Ewing's sarcoma are reviewed.

Sign in / Sign up

Export Citation Format

Share Document