Jan Goffin, Johan van Loon, Frank Van Calenbergh, and Bailey Lipscomb
In this study, long-term results are presented from clinical studies of the Bryan Cervical Disc Prosthesis at University Hospital Gasthuisberg in Leuven, Belgium. A total of 98 patients (89 with 1-level and 9 with 2-level implantations) agreed to participate in follow-up studies for up to 10 years postoperatively. This article focuses on the 4- and 6-year results. Patients in one of the clinical studies had either radiculopathy or myelopathy associated with spondylosis and/or disc herniations that did not respond to conservative treatment. Patients from the other clinical study received commercially available Bryan devices and the study protocol did not have specific inclusion/exclusion criteria. More than 90% of the patients were considered to have radiculopathy.
Clinical measurements discussed in the article include the 36-Item Short Form Health Survey, Neck Disability Index, numerical ratings of neck and arm pain, neurological outcomes, and Odom classification. Angular motion findings from lateral flexion-extension radiographs are also presented. The occurrence of adverse events and second surgeries are examined as an indicator of device safety.
The clinical outcomes at 4 and 6 years postoperatively appear consistent with the previously reported results at 1 and 2 years postoperatively. The mean angular motion results at 4 and 6 years postoperatively for 1-level patients were 7.3 and 7.7°, respectively. Two-level patients had slightly less motion at 4 and 6 years postoperatively with mean caudad values of 5.7 and 6.0°, respectively, and cephalad values of 4.2 and 6.2°, respectively. Efforts were made to capture adverse events, regardless of their nature and relatedness to the study surgery. This effort resulted in a relatively high number of recorded events. However, only 6 patients experienced events that were judged by the investigator to be related, either possibly or definitely, to the Bryan device. These events included device migration, device removal, and hoarseness and vocal cord paralysis, as well as 3 cases involving pain and neurological symptoms. Eight patients underwent further neck surgery to treat symptoms.
The favorable clinical and angular motion outcomes that were previously noted at 1- and 2-years' follow-up after cervical disc replacement with the Bryan Cervical Disc Prosthesis appear to persist after 4 and 6 years of follow-up.
Yoeri Vankan, Philippe Demaerel, Sam Heye, Frank Van Calenbergh, Johannes van Loon, Geert Maleux, and Guy Wilms
✓ The authors report an unusual case of a dural arteriovenous fistula (DAVF) in the cervical spine after a C1–2 fracture. The patient presented with a delayed epidural hematoma and quadriparesis. The DAVF was successfully treated by coil embolization and the patient made a full recovery. The possibility of a DAVF as a late complication of an upper cervical spine fracture should be considered when a patient presents with a spinal epidural hematoma.
A. Martina Messing-Jünger, Javier Ibáñez, Fabio Calbucci, Maurice Choux, Gabriel Lena, Iradj Mohsenipour, and Frank Van Calenbergh
The goal of this study was to assess the effectiveness and handling characteristics of a dura substitute composed of two outer layers of expanded polytetrafluoroethylene (PTFE) and a middle layer consisting of an elastomeric fluoropolymer.
In a prospective multicenter study, the dura substitute was implanted using a standard technique in 119 patients undergoing cranial or spinal surgery requiring duraplasty. Intraoperative assessments of the dura patch consisted of testing for cerebrospinal fluid (CSF) leakage employing the Valsalva maneuver and a surgeon’s standard evaluation of the handling characteristics of the device. Postoperative assessments conducted during a mean follow-up time of 15.7 months (range 0.3–45.6 months) consisted of physical examinations, routine computed tomography (CT) or magnetic resonance (MR) imaging studies, and histological studies of any removed dura patches.
The mean age of the 119 patients was 40 years (range < 1–81 years). The dura substitute was implanted cranially in 102 patients and spinally in 17. Intraoperative assessment including the Valsalva maneuver led to application of additional sutures in 17 patients. Handling features were rated very good to excellent. Postoperative clinical evaluation resulted in 79 excellent and 18 good results. Imaging studies (MR imaging studies in 69 patients and CT studies in 34 patients) showed no adhesions in 87 patients and minimal adhesions in seven patients (the dura was not visualized in nine patients). Postoperative complications occurred in 12 patients. There were six cases of CSF leakage, three cases of extradural hematoma, one case of arachnoid fibrosis after decompression of a Chiari malformation Type I, and two cases of infection. Eight (7%) of these complications were potentially related to the dura patch.
In a large, multicenter clinical study of the use of an expanded-PTFE–containing dura substitute, the device was found to be easy to handle and implant. No serious dura patch–related intraoperative adverse events were observed. Postoperatively, there were no major sealing problems or long-term complications. In two cases the patch had to be removed due to fibrosis and infection. The three-layer polymer dura substitute appears to be safe and effective in minimizing CSF leakage and adhesion formation, and its use avoids any risk of prion disease transmission.
Steven De Vleeschouwer, Frank Van Calenbergh, Philippe Demaerel, Patrick Flamen, Stefan Rutkowski, Eckhart Kaempgen, Johannes E. Wolff, Christian Plets, Raf Sciot, and Stefaan W. Van Gool
✓ Treatment of malignant glioma is difficult and discouraging. Even after resection and maximal adjuvant therapy, the prognosis remains poor. The authors sought a novel form of treatment, such as stimulating the patient's own immune response against the tumor, and developed a protocol of tumor vaccination in which autologous dendritic cells (DCs) were used in patients with recurrent malignant glioma. A 4-year-old girl was treated by means of biopsy sampling and radiotherapy for a rolandic low-grade glioma. Ten years later, a Grade III recurrence was discovered and treated with subtotal resection, interstitial radiation, six courses of oral temozolomide, and 12 courses of oral VP16. At the end of the chemotherapy cycle, a new rapidly growing recurrence was diagnosed. A macroscopically complete resection was performed. Afterward, the girl was vaccinated with autologous DCs that had been pulsed ex vivo with the homogenate of the resection specimen. She received six vaccines in total. The efficacy of immunization was checked by a positive delayed-type hypersensitivity skin reaction after the second injection. After the fifth vaccine, a transient contrast enhancement without mass effect was visualized on magnetic resonance imaging. Simultaneously, positron emission tomography imaging revealed a transient increase of metabolic activity around the resection cavity, but the metabolic uptake ratio remained below 1.8. The patient's disease is still in complete remission 24 months after the last surgery. She is clinically well with minor and stable left hemiparesis. This case report illustrates the potential of vaccination with DCs loaded with crude tumor homogenate as adjuvant therapy to induce prolonged tumor control of malignant glioma and the objective noninvasively monitored immune response against infiltrating tumor cells.
Johanna M. M. Gijtenbeek, Bram Jacobs, Sandra H. E. Sprenger, Marc J. Eleveld, Ad Geurts van Kessel, Johan M. Kros, Raf Sciot, Frank van Calenbergh, Pieter Wesseling, and Judith W. M. Jeuken
Object. Hemangioblastomas (HBs) occur sporadically or as a manifestation of von Hippel—Lindau (VHL) disease. In the majority of VHL-related HBs, inactivation of the VHL tumor suppressor gene (TSG), which is located on chromosome 3p25–26, is found. The VHL gene is assumed to be involved also in the development of sporadic HBs. In a previous study of chromosomal aberrations of sporadic HBs, multiple chromosomal imbalances were found in the majority of tumors. The aim of this study was to analyze further both sporadic HBs and VHL-related HBs to determine if these histopathologically identical tumors have a different genetic background.
Methods. Sixteen sporadic HBs and seven VHL-related HBs were identified by clinical criteria and analyzed. Comparative genomic hybridization was used to screen for chromosomal imbalances throughout the entire HB genome. Additionally, mutation analysis of the VHL gene was performed using direct sequencing.
Loss of chromosome 3 and multiple other chromosomal imbalances were found in the sporadic HBs, although only one imbalance, a loss of chromosome 3, was detected in the seven VHL-related HBs. Somatic VHL gene mutations were found in one third of sporadic HBs, whereas a mutation of the VHL gene was detected in all VHL-related HBs.
Conclusions. These results indicate that the molecular mechanisms underlying sporadic HBs and VHL-related HBs are different. Inactivation of the VHL gene is probably not the most important event in the tumorigenesis of sporadic HBs. Other mechanisms of inhibition of VHL protein function, or inactivation of other TSGs, on chromosome 3p or on other chromosomes, might be important in the development of sporadic HBs.