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At least 91 records · Page 5Linked to original sources
PubMed2004

Adaptation of a hexapod-based robotic system for extended endoscope-assisted transsphenoidal skull base surgery.

OBJECTIVE: To adapt a hexapod-based robotic system for use in extended endoscope-assisted transsphenoidal skull base surgery. METHODS: A robotic system (Evolution 1, Universal Robot Systems, Schwerin, Germany) based on a hexapod design with an attached seventh axis is used as instrument holder. The instrument interface is operated via a joystick control. An endoscope is applied to the instrument interface, which is tracked by a navigation system (Stealth, Medtronic, USA). RESULTS: The instrument holder was modified so that it could be applied in transsphenoidal surgery. Furthermore, translation and pivoting movements of the system were implemented, also a quick change between microscope and robotic-controlled endoscope was made possible. After extensive phantom testing two patients with large invasive pituitary adenomas were operated on using the robotic endoscope assistance during transsphenoidal surgery. The robotic assistance allowed the use of two additional instruments under endoscopic view. For example, drilling, suctioning, application of punches, as well as microsurgical tumor removal could be performed under endoscopic view. CONCLUSION: A robotic system could be adapted for use in endoscope-assisted transsphenoidal skull base surgery allowing simultaneous use of two instruments under endoscopic view. This opens new possibilities to extend transsphenoidal skull base surgery.

Adenoma↗
PubMed2003

Craniofacial and skull base trauma.

BACKGROUND: Traumatic craniofacial and skull base injuries require a multidisciplinary team approach. Trauma physicians must evaluate carefully, triage properly, and maintain a high index of suspicion to improve survival and enhance functional recovery. Frequently, craniofacial and skull base injuries are overlooked while treating more life-threatening injuries. Unnoticed complex craniofacial and skull base fractures, cerebrospinal fluid fistulae, and cranial nerve injuries can result in blindness, diplopia, deafness, facial paralysis, or meningitis. Early recognition of specific craniofacial and skull base injury patterns can lead to identification of associated injuries and allow for more rapid and appropriate management. CONCLUSION: Early detection and treatment of craniofacial and skull base traumatic injuries should lead to decreased morbidity and mortality. This review discusses the most common of these injuries, their possible complications, and treatment.

Accidents, Traffic↗
PubMed2003

[Endoscopic reconstruction of the anterior skull base in cerebrospinal rhinorrhea].

Cerebrospinal rhinorrhea is a discharge of cerebrospinal fluid caused by the break continuity in dura mater and by bone defect in the base of anterior skull base. The pathological connections appear mainly in the regions of the skull base with the weaker bone structure (the roof of the frontal, ethmoid, sphenoid sinus and cribriform plate). The aim of the study was presenting the possibility of the endoscopic-surgical closing the fistula within the ethmoid roof. The E.N.T Department in Poznań treated 5 patients with cerebrospinal rhinorrhea. In four cases, cerebrospinal rhinorrhea was caused by operative trauma. In one case the rhinorrhea could not be established. All patients with traumatic rhinorrhea underwent operation treatment based on covering of the loss in dura mater with a piece of mucous membrane together with perichondrium of nasal septum or lyophilised dura. The material used for the plastic operation was sealed by tissue adhesive. In 2 cases rhinorrhea recurred. Using the endoscopic technique, after the identification the leak of the cerebrospinal fluid within ethmoid roof, the fistula has been reconstructed with use of the adipose tissue and temporal muscle fascia. Both cases led to complete recovery. Easy access, precision and accuracy of performance the surgery, the approach without external incision of the patient, makes the endoscopic technique very valuable method in treating rhinorrhea caused by the loss in ethmoid roof and cribriform plate.

Adult↗
PubMed1998

Anatomo-radiological evaluation of lateral approaches to the skull base.

Our objective is to correlate the anatomical exposure provided by complex skull base approaches to the lateral skull base with their CT and MRI scans counterparts and to introduce a modular concept emphasizing the derivation of complex skull base approaches from simpler ones.We executed 10 lateral approaches to the skull base in 20 embalmed cadaveric heads (40 sides). Each approach was executed a minimum of three times on each specimen. These approaches were the pterional and its modifications, the subtemporal and its modifications, and the suboccipital and its modifications. We correlated the approaches and the areas of the skull base exposed by scanning the surgical cavity filled with material imageable by CT and MRI and throughly surveying the operative field.Visualization of the area of the skull base exposed was excellent using our CT-MRI imageable cadaveric preparation. The topographic areas of the skull base exposed correlated well with their radiological counterparts.The areas of the skull base exposed by each of the complex surgical approaches to the skull base were clearly delineated by using our anatomo-radiological correlation. Complex approaches to the skull base are formed by simple neurosurgical approaches (building blocks) to which different modules are added.

Journal Article↗
PubMed2005

Trans-eyebrow mini-orbitozygomatic pterional approach for minimally invasive skull base surgery.

Surgical treatment of skull base pathologies remains one of the most challenging tasks to neurosurgeons. Advances in neuroimaging as well as the evolution of modern techniques and neurosurgical equipment have paved the way for a more precise diagnosis, a better selection of the surgical approach and have prompted the adaptation of minimally invasive concepts to different aspects of modern neurosurgical practice. The trans-eyebrow mini orbitozygomatic pterional approach is a tailored approach that provides multiple avenues to the target, minimizing retraction of the brain and affords better exposure of the pathology. It was performed on 16 patients with frontobasal or suprasellar tumors. The post-operative clinical outcome was excellent with smooth and fast recovery as well as satisfactory cosmetic results. It should be considered as part of the armamentarium to manage skull base lesions when indicated and not to replace other well recognized skull base approaches.

Brain Diseases↗
PubMed2004

Contemporary skull base reconstruction.

PURPOSE OF REVIEW: Tumors of the skull base that would have been considered inoperable thirty or forty years ago are now routinely resected with reliable results due to the advancement of modern reconstructive techniques. High mortality rates were common prior to the use of vascularized tissue for skull base repair. However, the advent of local flap reconstruction for skull base defects in the 1960s revolutionized skull base surgery. The use of regional flaps in the 1970s and 1980s allowed skull base surgeons to perform more extensive surgeries, but complication rates were still quite high. RECENT FINDINGS: Experience with free tissue reconstruction increased through the 1980s and 1990s and has become a reliable method to separate the intracranial from extracranial environments. Free tissue transfer has allowed surgeons to address the large volume defects created by extensive skull base resections and has provided dependable, vascularized tissue that is relatively resistant to adjuvant radiation. Local flaps have also become a powerful reconstructive tool in conjunction with free tissue transfer, and in some select cases, may be sufficient alone for reconstruction. SUMMARY: The prevention of serious complications after skull surgery has improved with the use of vascularized tissue. Depending on the anatomic site, the extent of the defect, and the quality of local tissues, either free tissue transfer and/or local flap reconstruction is preferred. Regional flap reconstruction should be reserved for cases where alternative reconstructive techniques are not available.

Bone Transplantation↗
PubMed1991

Radiographic evaluation of the skull base.

The anatomic complexities of the skull base and the variable clinical presentation of skull base tumors often precludes accurate determination of tumor boundaries by history and physical alone. Imaging, employing computed tomography (CT) and magnetic resonance imaging (MR) allows for accurate tumor mapping and planning of appropriate therapeutic intervention. Calvarium floor involvement and extracranial lesions are well delineated by CT. While multiplanar MR is unparalleled in demonstrating tumor boundaries and extension through the skull base. In order to employ these imaging modalities in an efficient way, it is important to understand the limitations and capabilities of these modalities as well as the imaging characteristics of common skull base lesions.

Brain Neoplasms↗
PubMed2003

Use of the free vastus lateralis flap in skull base reconstruction.

Free flaps in skull base reconstruction are indicated for providing an effective separation of the intracranial cavity from the oronasal space, for eliminating a dead space, and for the treatment of established wound complications such as dural exposures and cerebrospinal fluid leaks. Seven patients with cranial base defects underwent reconstructions using a free vastus lateralis muscle flap. In two cases, a vastus lateralis flap was raised to incorporate the anterolateral thigh skin as a myocutaneous flap. In four cases, a free flap was indicated for reconstruction following tumor ablation, and in three cases, for the resolution of wound or cerebrospinal fluid leak complications following previous cranial base surgery. All flaps were successful, with no partial failures. In those patients undergoing tumor ablative surgery, the cranial cavity was effectively sealed from the oronasal cavity. Patients with established wound complications following previous cranial base surgery had a complete resolution of their symptoms. This report discusses the suitability of the vastus lateralis flap for skull base reconstruction in terms of the availability of adequate muscle volume to fill dead space, vascularized fascia to augment dural repairs, and the freedom to use skin if required for internal lining or external skin cover. This flap also provides an extremely long pedicle, allows simultaneous flap harvest, and has low donor site morbidity.

Adult↗
PubMed1998

Treatment of posterior skull base tumors.

Surgery for posterior skull base tumors may be associated with high morbidity and mortality because of the complex anatomy, irregular bony topography, and vital neurovascular structures in this region. We experienced three benign posterior skull base tumors. These were petroclival and foramen magnum meningiomas and a jugular formen neurinoma. Three dimensional computed tomography (3 D-CT) in addition to the conventional CT, magnetic resonance imaging (MRI), and cerebral angiography were performed preoperatively. Preoperative embolizations for the tumors were also done, and intraoperative neurophysiological monitorings were performed. The tumors could be subtotally removed with no damage to the brainstem, cranial nerves, and vessels. No newly developed postoperative neurological symptoms were observed. As to the remaining tumors, gamma knife (gamma-knife) therapy was planned. 3 D-CT was very useful in the preoperative evaluation of the surgical approach, and the intraoperative neurophysiological monitoring was considered to be necessary to prevent permanent damage. gamma-knife after direct approach was recommended for the benign posterior skull base tumors.

Adult↗
PubMed2002

Malignant tumors of the skull base.

Malignant tumors of the skull base have traditionally been difficult to control because of adjacent crucial anatomical structures and because of the inherent difficulty in accessing/resecting tumors and reconstructing surgical defects. Techniques in craniofacial surgery for malignant tumors of the skull base have advanced significantly since their first description. Advances in neuroimaging, surgical technique, perioperative care, and adjuvant treatment have contributed to improved results. Because the majority of malignant tumors requiring craniofacial resection involve the anterior skull base, this review focuses mainly on state-of-the-art surgical techniques as well as pertinent variations, complications and results.

Cranial Fossa, Anterior↗
PubMed1999

Skull base growth in childhood.

While studying skull base changes in craniosynostosis, it became apparent that there is a lack of reference studies quantifying the changes of three-dimensional (3D) parameters of the normal skull base throughout childhood. Using advanced 3D visualisation techniques, 34 points of the skull base were identified on MRI scans of 66 normal children, aged 1 month to 15 years. Several distances and angles between the various landmarks were measured in an attempt to quantify the growth of skull fossae with age. Two main growth periods were observed: before and after the first 5 years of life. Most change occurred in the first period. Anatomical regional differences were identified between the two sexes. During the first 5 years of life, the anterior fossa showed rapid growth rate with respect to its anterior projection in males, whereas in the females there was a more concentric growth pattern. The body of the sphenoid bone and the middle fossa showed a rapid growth rate in both sexes which was greater in the females. The posterior fossa showed a concentric pattern of growth in both sexes with a greater growth rate in the females. These findings provide new insight into the pattern of growth of the various parts of the skull base and can be used for comparative study of deformities that affect such growth.

Adolescent↗
PubMed1993

Preparation of the human skull for skull base anatomic study.

Human skulls are unsurpassed in the ability to provide three-dimensional instruction in osteology as well as understanding the sites of soft tissue insertion and the intricate course of neurovascular structures in the skull base. Recent geopolitical developments in Asia have led to extreme difficulty in obtaining human skull specimens. The purpose of this article is to present a method for the preparation of dried human skulls from fresh and frozen cadavers using commonly available chemicals. The technique, requiring about 8 weeks total time and basic equipment, consists of maceration accelerated by several enzymes followed by defatting, washing, and bleaching. The skulls produced are of excellent quality and durability with no preparation artifacts. An economical source of skulls has now been reestablished to facilitate learning of the intricate relationships of the skull base.

Journal Article↗
PubMed2006

Comparison of linac based fractionated stereotactic radiotherapy and tomotherapy treatment plans for skull-base tumors.

BACKGROUND AND PURPOSE: To compare and evaluate helical tomotherapy and linac based fractionated stereotactic radiotherapy (FSRT) techniques in the treatment of skull-base tumors. PATIENTS AND METHODS: Ten patients diagnosed with skull-base tumors, originally planned for optically guided FSRT to prescribed doses of 50.4-54 Gy were replanned for treatment with clinically deliverable helical tomotherapy. All original CT scans, MR-CT fusion defined target and normal structure contours, and PTV margins were used for helical tomotherapy planning. Linac based plans utilized one of the following FSRT planning techniques: non-coplanar or coplanar intensity modulated radiation therapy (IMRT), multiple non-coplanar conformal arcs, and non-coplanar conformal radiation therapy (CRT). These plans were used as the standard to which the subsequent tomotherapy plans were compared, using the following criteria: prescription isodose to target volume (PITV) ratios, an inhomogeneity index (II), equivalent uniform dose (EUD) for PTV volumes, mean normalized total doses (NTDmean) for critical structures, and size of 10, 20, and 30 Gy isodose volumes. RESULTS: Use of both linac based FSRT techniques and helical tomotherapy generated highly conformal treatment plans. Tomotherapy plans, which are predominantly coplanar in nature, compared to non-coplanar linac based plans exhibited increased PITV ratios, variable change in II, similar EUD values, and generally comparable NTD(mean) values for organs at risk. When compared to non-coplanar field arrangements, deliverable (as opposed to idealized) tomotherapy plans also resulted in 13-540% increases in low dose isodose volumes. All criteria except for the II, which was generally improved with tomotherapy, were found to be similar when coplanar linac based plans were compared to helical tomotherapy plans. CONCLUSIONS: Results show a distinct advantage in using non-coplanar beam arrangements for treatment of skull-base tumors. In the case where disease spreads far inferiorly, limiting the ability to use non-coplanar arrangements, helical tomotherapy can be used to generate a comparable treatment plan, with potentially superior homogeneity.

Algorithms↗
PubMed1996

Open transnasal approach to the midline skull base.

Surgical access to the anterior skull base for resection of midline tumors is commonly performed through a transfacial approach. We describe a new, open transnasal approach to the midline skull base and adjacent pituitary region. This technique, devised through our experience with open septorhinoplasty, was initially studied on fresh cadaver heads. It has subsequently been used in 28 consecutive patients for the resection of a variety of midline skull base tumors. We believe that this approach is superior to the traditional rhinal and sublabial transfacial techniques because of the wider exposure and true midline orientation that it offers. In addition, no mucosal membrane is violated, therefore providing a greater seal of the dissection postoperatively. A detailed description of the technique and the results of its clinical use are presented.

Adenoma↗
PubMed1991

Salmonella osteomyelitis of the skull base.

A case of skull base osteomyelitis caused by Salmonella is reported. The patient, a diabetic immunosuppressed man, had a insidious presentation of nasopharyngeal and cranial nerve findings. His radiologic studies showed a striking destruction of the skull base. He died despite antibiotic therapy. Relevant literature is discussed.

Azathioprine↗
PubMed1995

Clinical experience of neurosurgical reconstruction in anterior skull base lesions.

BACKGROUND: Surgery of the anterior skull base confronts with the life-threatening risks of infection and cerebrospinal fluid (CSF) leakage, especially after extensive tumor resection. Avoidance of these complications demands a good intraoperative reconstruction. The technical feasibility has been demonstrated in previous reports. A judicious rationale of surgical principle is investigated in review of our patients and other series. METHODS: Fourteen cases underwent neurosurgical procedures involving the anterior skull base by the authors between June 1992 and January 1994. Five patients with trauma, 1 with inflammation, and 8 with space-occupying lesion were included. The modality of skull base reconstruction and patients' outcome were evaluated. RESULTS: Eleven of these cases accepted reconstructive procedures to some extent including pericranium, lyodura, tissue glue, bone graft and muscle flaps. Four cases of traumatic CSF leakage were successfully repaired after anterior skull base reconstruction. One case with traumatic optic neuropathy restored vision after surgical optic nerve decompression. A rhinogenic infected discharging sinus was cured with pedicle island flap obliteration. Space-occupying lesions in 8 cases were totally removed without postoperative wound infection, CSF leakage, or meningitis, of which 2 cases of malignancy recurred 7 and 5 months after operation respectively. The follow-up period was from 5 to 26 months with a mean of 14 months. CONCLUSIONS: Meticulous reconstruction with different possibilities of closure is the cornerstone of anterior skull base surgery, in spite of its difficulties and needs for extensive resection. Combined craniofacial resection could achieve "en bloc" or radical excision of "inoperable" anterior skull base lesions confidently with low morbidity and mortality based on skillful reconstructive techniques.

Adolescent↗
PubMedDate not supplied

[Skull base meningiomas spreading into the infratemporal fossa: clinical picture, diagnosis, and treatment policy].

From 1997 to 2004, the Academician N. N. Burdenko Research Institute of Neurosurgery has operated on 54 patients with intracranial meningiomas spreading into the infratemporal fossa. Fifteen patients were operated on for the first time. Thirty-nine patients had undergone surgical interventions on the average 3 times (from 2 to 8). All the patients were operated on via different orbitozygomatic approaches depending on the extent of the process. Opening the upper and lower palpebral fissures and the round foramen with resection, if required, the pterygoid processes suffice to remove tumors from the areas of the upper and lower palpebral fissures, which spread into the sphenoid and maxillary sinuses. If there are tumors at the site of the base of the anterior surface of the pyramid, and the articular bursa, it is expedient to open the oval and spinous foramens, to resect the external portions of the fundus of the middle cranial fossa and, if required, the articular process of the lower jaw. By taking into account the X-ray and histological patterns, it may be stated that invasion of meningiomas is not always accompanied by the development of hyperostosis. According to our findings, extracranial growth of meningiomas points to the invasion of osseous structures of the middle cranial fossa. Furthermore, if meningiomas grow into the infratemporal fossa, they frequently involve the muscles, nerves, and mucosa. After removing the tumors spreading to the infratemporal fossa, the optimum plastic repairs of defects of the base of the skull are as follows: hermetic closure of basal defect of the dura mater with a free fat flap, by fixing it with sutures and fibrin-thrombin glue with additional plastic repair of skull base defect with local displaced tissues on a pedicle (with a temporal muscular fascioperiosteal flap, a Bisch fat flap). Further policy of management of these patients is a complicated problem. It depends on the radicalism of an operation and the invasiveness of the process. The histobiological features of infiltrative meningiomas should be studied and this will determine management policy. Conceivably, the use of postoperative radiation therapy will be substantiated in a definite group of patients.

Cerebral Angiography↗
PubMed2000

Advanced image-guided skull base surgery.

BACKGROUND: Tumors of the skull base frequently encase or extend into normal neural and vascular structures. Preoperative planning and intraoperative identification of anatomic landmarks is especially important in complex tumors since it helps avoid or minimize surgical morbidity. METHODS: By creating a surgical plan the image guidance software offers help in the establishment of a surgical approach. During surgery, the neuronavigation system displays the location of anatomic landmarks of the skull base regardless of any erosion or displacement. RESULTS: A series of 10 patients with complex tumors in various skull base locations is reported. Osseous structures are easily identified using the CT-based image guidance since these landmarks do not shift due to CSF loss. Image fusion of CT and MRI data gives additional information on the displacement of soft tissue structures. Image fusion in a substraction mode is helpful when a tumor has invaded bony structures or when the encasement of major vessels has to be visualized. CONCLUSION: The preoperative data preparation (planning of the approach, image fusion) plays a vital role in modern neuronavigation and contributes useful information during surgery for complex skull base tumors. Such advanced neuronavigation increases the efficacy and safety of intraoperative maneuvers. Eroded and distorted anatomic landmarks are not subject to a significant amount of intraoperative shift throughout the surgical procedure.

Adult↗