0000000000184144
AUTHOR
Jens Conrad
showing 15 related works from this author
Inflammatory pituitary lesions
2021
Abstract Inflammatory pituitary lesions are rare but important differential diagnoses of nonfunctioning pituitary masses. Primary hypophysitis as an autoimmune disorder has received increasing attention over the past decades. In the last decade, immune checkpoint inhibitor–induced hypophysitis has emerged as a new type of secondary hypophysitis. Various pituitary tumors may also cause secondary hypophysitis. Systemic, noninfectious granulomatous diseases that can involve the pituitary region include sarcoidosis, granulomatosis with polyangiitis, Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai-Dorfman disease. Furthermore, infectious diseases can affect the pituitary gland.…
Simple endoscopic decompression of cubital tunnel syndrome with the Agee system: anatomic study and first clinical results.
2010
BACKGROUND Simple decompression in ulnar nerve compression syndromes offers options for endoscopic applications. OBJECTIVE The authors present their initial experience with the Agee device. PATIENTS AND METHODS The monoportal endoscopic technique (Agee system) was evaluated on 10 cadaveric arms. Subsequently, 32 arms of 29 patients were operated on between January 2006 and March 2009. All patients presented with typical clinical signs and neurophysiologic studies. Long-term follow-up examinations were obtained in 27 of 32 arms. RESULTS In the cadaver study, the ulnar nerve was always correctly identified. No nerve damage occurred, and sufficient decompression of the ulnar nerve was always a…
TUMORS OF THE LATERAL AND THIRD VENTRICLE
2005
Abstract OBJECTIVE: Intraventricular tumors usually are managed by approaches and microsurgical techniques that need retraction and dissection of important brain structures. Minimally invasive endoscopic procedures achieve a remarkable alternative to conventional microneurosurgical techniques. Endoscope-assisted microneurosurgery may be a minimally invasive technique with maximally effective treatment. Using the keyhole concept for planning the surgical strategy, the reduction of the brain retraction is achieved, which is one of the main benefits of this technique. METHODS: We treated 35 patients (16 female patients and 19 male patients) with tumors in the lateral (n = 8) and the third (n =…
Mesencephalic ependymal cysts: treatment under pure endoscopic or endoscope–assisted keyhole conditions
2008
Object Primary intracranial ependymal cysts are extremely rare. Similar to congenital intraparenchymal cysts in the mesencephalon they usually occur with symptoms of an occlusive hydrocephalus or symptoms like Parinaud syndrome, dizziness, or gait disturbance. The objective of this study was to evaluate the surgical methods for the treatment of these cysts and the clinical outcome of the patients. Methods The authors present the clinical records of 8 patients who were treated in their department for symptomatic mesencephalic ependymal cysts in the past 10 years. The patient age ranged from 22 to 60 years with a mean age of 44 years. In 4 cases the authors performed a suboccipital infratent…
Evaluation of robot-guided minimally invasive implantation of 2067 pedicle screws
2017
ObjectiveRecent studies have investigated the role of spinal image guidance for pedicle screw placement. Many authors have observed an elevated placement accuracy and overall improvement of outcome measures. This study assessed a bi-institutional experience following introduction of the Renaissance miniature robot for spinal image guidance in Europe.MethodsThe medical records and radiographs of all patients who underwent robot-guided implantation of spinal instrumentation using the novel system (between October 2011 and March 2015 in Mainz and February 2014 and February 2016 in Regensburg) were reviewed to determine the efficacy and safety of the newly introduced robotic system. Screw posit…
High-definition imaging in endoscopic transsphenoidal pituitary surgery.
2011
Background The transsphenoidal approach to sellar lesions has evolved enormously since its first description in the early 20th century. Endoscopic surgical strategies have become an integral part of the surgical armamentarium. More recently, high-definition (HD) digital cameras with better image resolution were introduced, although their value for the surgical procedure remains equivocal. The purpose of this study was to compare the image quality of a standard-definition (SD) camera with a new HD camera. Methods A transsphenoidal pituitary adenomectomy was recorded simultaneously in HD and SD resolution. Eight experienced neurosurgeons were asked to identify predefined as well as not predef…
Positioning of the Patient and Related Complications
2019
Optimal positioning of patients for spine surgery is crucial for ideal surgical conditions and operative-site exposure. During surgery of the spine patients are placed in non-physiological conditions already in anesthesia which lead to complications as patients are not able react to an unpleasant tissue damaging position. The factors duration of a surgical procedure, mechanical pressure and immobility increase the risk for positioning related complications and rare complications such as postoperative visual loss (POVL) or perioperative peripheral nerve injury (PPNI) result in significant patient disability and functional restrictions.
Consensus on Postoperative Recommendations After Transsphenoidal Surgery
2018
Abstract Background Guidelines for patient behavior following transsphenoidal surgery do not exist. To gain generally recommendations, the German pituitary working group conducted a study among pituitary surgeons to elucidate their opinions and customs of patients’ counselling. Methods Questions concerning daily activities, exertion of sports and work life were addressed. It was asked to provide the postoperative time interval after which specific activities can be resumed both after a routine or an extended approach. Results Fourteen pituitary surgeons returned the completed questionnaire. Following routine operations, washing the hair was allowed within one week, blowing the nose after 3,…
Multicolor 3D Printing of Complex Intracranial Tumors in Neurosurgery.
2020
Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. The model can be used for planning and simulating critical steps of a surgical approach. Therefore, it is important that anatomical structures such as blood vessels inside a tumor can be printed to be colored not only on their surface, but throughout their whole volume. During simulation this allows for the removal of certain parts (e.g., with a high-speed drill) and revealing internally located structures of a different color. Thus, diagnostic information from various imaging modalities (e.g., CT, MRI) can be combined in a single compact …
Autostereoscopic Three-Dimensional Neuronavigation to the Sella: Technical Note.
2017
Background A drawback of conventional neuronavigation is the necessity of focusing on two-dimensional images in 3 planes at the same time to determine one's position in the operating field. A solution would be to merge the images into a single three-dimensional (3D) image that mirrors the actual anatomy. The introduction of holographic glassless 3D monitors paved the way to 3D navigation. We present our experience with 3D neuronavigation as exemplified by navigation to and within the sella. Methods Operative planning was conducted with a navigation system using cranial computed tomography and magnetic resonance imaging. The image data sets were processed by the prototype Clariti 3D system t…
Use of a clinicoradiological score to determine the presurgical diagnosis of autoimmune hypophysitis in a teenage girl.
2013
The distinction between autoimmune hypophysitis and other non–hormone secreting pituitary masses is often difficult to determine with certainty without pituitary biopsy and pathological examination. To aid in this distinction, the authors recently published a clinicoradiological scoring system, which they used in the case of a 15-year-old girl presented here. The patient presented with headache, visual field defects, polydipsia, and polyuria, and she was found to have secondary hypogonadism and hypoadrenalism. Magnetic resonance imaging showed a pituitary mass of approximately 2 cm in diameter. Application of the clinicoradiological parameters gave a score of −6, which favored a diagnosis o…
Binostril versus mononostril approaches in endoscopic transsphenoidal pituitary surgery: clinical evaluation and cadaver study.
2016
OBJECTIVE Over the past 2 decades, endoscopy has become an integral part of the surgical repertoire for skull base procedures. The present clinical evaluation and cadaver study compare binostril and mononostril endoscopic transnasal approaches and the surgical techniques involved. METHODS Forty patients with pituitary adenomas were treated with either binostril or mononostril endoscopic surgery. Neurosurgical, endocrinological, ophthalmological, and neuroradiological examinations were performed. Ten cadaver specimens were prepared, and surgical aspects of the preparation and neuroradiological examination were documented. RESULTS In the clinical evaluation, 0° optics were optimal in the nas…
Three-dimensional Cross-Platform Planning for Complex Spinal Procedures
2017
STUDY DESIGN A feasibility study. OBJECTIVE To develop a method based on the DICOM standard which transfers complex 3-dimensional (3D) trajectories and objects from external planning software to any navigation system for planning and intraoperative guidance of complex spinal procedures. SUMMARY OF BACKGROUND DATA There have been many reports about navigation systems with embedded planning solutions but only few on how to transfer planning data generated in external software. MATERIALS AND METHODS Patients computerized tomography and/or magnetic resonance volume data sets of the affected spinal segments were imported to Amira software, reconstructed to 3D images and fused with magnetic reson…
Endoscopic endonasal pituitary surgery: Surgical and outcome analysis of 50 cases
2007
Abstract Objective Microsurgical transsphenoidal surgery for pituitary tumors has been standard therapy for decades and was established by Harvey Cushing in the early twentieth century. Today, endoscopy is increasingly accepted in the therapy of pituitary lesions. In this retrospective study, we analysed the surgical technique and outcome of 50 patients with pituitary lesions treated with an endoscopic endonasal trans-sphenoidal approach. Methods Between January 2004 and July 2005, 50 patients (30 female and 20 male) with pituitary tumors were operated upon using an endoscopic endonasal trans-sphenoidal procedure without nasal speculum or postoperative nasal packing. The follow-up period ra…
Cleanroom Installations for SRF Cavities at the Helmholtz-Institut Mainz
2019
The 10th International Particle Accelerator Conference, IPAC2019, Melbourne, Australia, 19 May 2019 - 24 May 2019; JACoW Publishing, Geneva, Switzerland 2830-2833 (2019). doi:10.18429/JACOW-IPAC2019-WEPRB015