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Featured researches published by Insa Janssen.


Neuro-oncology | 2014

Preoperative motor mapping by navigated transcranial magnetic brain stimulation improves outcome for motor eloquent lesions

Sandro M. Krieg; Jamil Sabih; Lucia Bulubasova; Thomas Obermueller; Chiara Negwer; Insa Janssen; Ehab Shiban; Bernhard Meyer; Florian Ringel

BACKGROUND Navigated transcranial magnetic stimulation (nTMS) has been proven to influence surgical indication and planning. Yet there is still no clear evidence how these additional preoperative functional data influence the clinical course and outcome. Thus, this study aimed to compare patients with motor eloquently located supratentorial lesions investigated with or without preoperative nTMS in terms of clinical outcome parameters. METHODS A prospectively enrolled cohort of 100 patients with supratentorial lesions located in motor eloquent areas was investigated by preoperative nTMS (2010-2013) and matched with a control of 100 patients who were operated on without nTMS data (2006-2010) by a matched pair analysis. RESULTS Patients in the nTMS group showed a significantly lower rate of residual tumor on postoperative MRI (OR 0.3828; 95% CI 0.2062-0.7107). Twelve percent of patients in the nTMS and 1% of patients in the non-nTMS group improved while 75% and 81% of the nTMS and non-nTMS groups, respectively, remained unchanged and 13% and 18% of patients in the nTMS and non-nTMS groups, respectively, deteriorated in postoperative motor function on long-term follow-up (P = .0057). Moreover, the nTMS group showed smaller craniotomies (nTMS 22.4 ± 8.3 cm(2); non-nTMS 26.7 ± 11.3 cm(2); P = .0023). CONCLUSIONS This work increases the level of evidence for preoperative motor mapping by nTMS for rolandic lesions in a group comparison study. We therefore strongly advocate nTMS to become increasingly used for these lesions. However, a randomized trial on the comparison with the gold standard of intraoperative mapping seems mandatory.


World Neurosurgery | 2016

Early Morbidity and Mortality in 50 Very Elderly Patients After Posterior Atlantoaxial Fusion for Traumatic Odontoid Fractures

Yu-Mi Ryang; Elisabeth Török; Insa Janssen; Andreas Reinke; Niels Buchmann; Jens Gempt; Florian Ringel; Bernhard Meyer

BACKGROUND Traumatic odontoid fractures (tOFs) in the very elderly are associated with high morbidity and mortality. The best treatment strategy (conservative vs. surgery) is still unclear. METHODS Between April 2008 and April 2014, fifty (17 male, 33 female) patients (mean age 87.2 ± 4.4 years; range: 80-99) were included in this retrospective cohort study. All patients underwent posterior fusion surgery for tOF. Early outcome, morbidity and mortality, length of hospital and intensive care unit (ICU) stay, comorbidities, and perioperative complications were assessed. RESULTS The mean age-adjusted Charlson Comorbidity Index (CCI) was 5.8 ± 3.9 (range: 0-13), and the mean American Society of Anesthesiologists score was 3 ± 0.5 (range: 2-4). Surgery was delayed in 48% of patients. Thirty percent of patients had preoperative complications (72.4% severe), of which a leading cause was dysphagia with subsequent pneumonia, and 18% required preoperative assessment or improvement of health status. Surgery-related complications were experienced in 14% with no neurovascular lesion. Postoperative medical complications occurred in 52% of patients (67.3% severe). Major complications were mostly respiratory/pulmonary (66.7%), of which postoperative pneumonia (36.4%) was leading. Twenty-four percent of patients were ICU monitored. Mean length of ICU stay was 9 ± 6.6 days (1-20). Mean length of hospital stay was 15 ± 8.6 days (4-56). There was no in-hospital mortality, and 30-day mortality was 6%. CONCLUSIONS Posterior fusion for tOF in patients 80 years or older seems to be a feasible treatment option in these high-risk patients. Despite a high incidence of severe comorbidities and perioperative complications, outcome was satisfactory. LEVEL OF EVIDENCE Our research was a retrospective cohort study, Level III.


The Spine Journal | 2017

Risk of cement leakage and pulmonary embolism by bone cement-augmented pedicle screw fixation of the thoracolumbar spine

Insa Janssen; Yu-Mi Ryang; Jens Gempt; Stefanie Bette; Julia Gerhardt; Jan S. Kirschke; Bernhard Meyer

BACKGROUND Cement-augmented pedicle screw instrumentation (CAPSI) of the thoracolumbar spine is indicated in osteoporosis or osteopenia to improve pullout strength and biomechanical stability of pedicle screws (PS). Only a few studies report on the incidence of pulmonary cement embolism or other complications associated with CAPSI. PURPOSE The aim of this retrospective study was to assess the rate of CAPSI-associated complications. STUDY DESIGN Retrospective cohort study. PATIENT SAMPLE Patients who underwent CAPSI due to spinal tumors or degenerative spine disease. OUTCOME MEASURES Cement leakage, pulmonary cement embolism (PCE), mortality rate. METHODS Our clinical database was reviewed for patients who underwent CAPSI between January 2012 and June 2015. A total of 165 patients (mean age 71±11.2; range: 46 to 93 years; m=62, f=103) were included. Indications were osteoporotic fractures (n=40), spinal metastases (n=57), degenerative (n=49) or infectious spine disease (n=5), and traumatic vertebral fractures (n=14) with an associated osteoporosis. Every patient received between 2 and 21 (mean 8±3.3) cement-augmented pedicle screws in the thoracolumbar and lumbosacral spine. Both intraoperative cement leakage in prevertebral veins, the inferior vena cava, and/or pulmonary arteries, and leakage detected on postoperative imaging were evaluated. We assessed the incidence of clinically symptomatic and asymptomatic events. RESULTS In 29 of 31 patients with intraoperative suspicion of cement leakage into prevertebral veins or the inferior vena cava on lateral fluoroscopy, which were without hemodynamic relevance, cement extrusion was confirmed on postoperative X-ray or computed tomography (CT) scan. In three of eight patients with suspicion of PCE, PCE was verified on thoracic CT. Four patients experienced life-threatening intraoperative hemodynamic reactions, either due to cement embolism (n=2; 1.2%) or anaphylactic shock (n=2; 1.2%) with need for intraoperative cardiopulmonary resuscitation in three cases. Two patients died due to fulminant PCE. Three patients with dyspnea 1 day after surgery were also confirmed with PCE on chest CT. In five patients, an asymptomatic PCE was found incidentally on postoperative imaging. In addition, 68 patients with cement leakage into prevertebral veins or the ascending cava vein were found incidentally on postoperative spine X-ray or CT. Two of 10 patients with intraspinal epidural cement leakage required revision surgery. One hundred ten of 165 patients (66.7%) had clinically asymptomatic cement leakage. Thirteen patients had PCE (7.9%), of whom five (3.0%) were symptomatic. Two patients experienced intraoperative cement-induced anaphylaxis (1.2%). The overall symptomatic complication rate was 5.5% (n=9). The 30-day mortality rate was 1.8% (n=3). CONCLUSIONS CAPSI bears a high risk of asymptomatic cement leakage. The risk for associated severe complications was also relatively high and probably underestimated considering the retrospective nature of the present study. A strict indication for cement augmentation, especially in patients with cardiac predisposition, should be the consequence. We doubt that technical aspects of cement application and/or different types of cement are capable of reducing the risk of these complications substantially.


World Neurosurgery | 2018

Is Eighty the New Sixty? Outcomes and Complications after Lumbar Decompression Surgery in Elderly Patients over 80 Years of Age

Julia Gerhardt; Stefanie Bette; Insa Janssen; Jens Gempt; Bernhard Meyer; Yu-Mi Ryang

OBJECTIVE An increasing demographic aging of the general population results in a rising incidence of octogenarians and nonagenarians with spine disease. Patients older than 65 years represent the majority of patients with degenerative lumbar spine disease in our daily clinical routine. Surgical treatment is undertaken reluctantly because of an increased rate of comorbidities. We therefore assessed complication rates of lumbar decompression in regard to neurological outcome and medical conditions in patients age 80 years or older in a retrospective single-center series. METHODS Data for 244 patients (124 female, 120 male; mean age, 83.1 ± 3 years; age range, 80-95 years) who underwent decompressive surgery for lumbar spinal stenosis or disc herniation between April 2007 and February 2016 were assessed retrospectively. Age at surgery, neurologic deficits (preoperative and postoperative), relevant medical comorbidities and previous lumbar decompression, intraoperative and postoperative complications (e.g., surgery-related, medical), duration of surgery, length of hospital stay, and rate of revision surgeries were recorded. RESULTS Surgery was performed for lumbar stenosis (184 patients; 75.4%), lumbar disc herniation (13 patients; 5.3%) or both (47 patients; 19.3%). Seventy-six patients (31.3%) patients experienced preoperative neurologic deficits; 48 (63.2%) of these patients improved, 28 (36.8%) of them were unchanged after surgery, and none deteriorated. New transient, postoperative, neurologic deficits occurred in 6 patients (2.5%). All 55 (22.5%) intraoperative complications were mild to moderate, and no severe surgical complications occurred. Two hundred fifteen patients (88%) had relevant medical disorders. Nineteen (7.7%) postoperative medical complications were reported in 17 patients (7%), of which 14 (73.7%) were severe and 5 (26.3%) were mild (4 pulmonary embolisms, 6 pneumonias, 3 myocardial infarctions, 1 postoperative renal failure, 5 urinary tract infections). Medical complications that necessitated intensive care unit treatment and resulted in lethal outcome were seen in 2 patients (0.8%). CONCLUSION Despite their age, the vast majority of octogenarians and nonagenarians benefited from lumbar decompression surgery. Mild to moderate intraoperative complications were relatively frequent, whereas severe intraoperative complications did not occur. The majority of medical complications was severe, but the incidence was acceptable, and the postoperative outcome was still favorable in most patients.


Acta Neurochirurgica | 2017

L5 corpectomy—the lumbosacral segmental geometry and clinical outcome—a consecutive series of 14 patients and review of the literature

Martin Vazan; Yu-Mi Ryang; Julia Gerhardt; Felix Zibold; Insa Janssen; Florian Ringel; Jens Gempt; Bernhard Meyer

PurposeWe analyzed the lumbosacral segmental geometry and clinical outcome in patients undergoing L5 corpectomy.MethodsFourteen consecutive patients who underwent L5 (n = 12) or L4 + 5 (n = 2) corpectomy at our department between January 2010 and April 2015 were included. All patients underwent a baseline physical and neurologic examination on admission. The diagnostic routine included MRI and CT scans and, if possible, an upright X-ray of the lumbar spine before and after surgery. The local lordosis angle [L4(L3)-S1] was measured.ResultsThe most common pathology was infection (N = 7), followed by neoplastic disease (n = 3), pseudarthrosis (n = 2) after previous spinal fusion procedures and burst fractures (n = 2) of the L5 vertebral body. We observed seven complications (2 intraoperative; 5 postoperative) in five (36%) patients. Three patients needed revision surgery because of cage subsidence and/or dislodgement (21%). Additional anterior plating was used in two of the revision surgeries to secure the cage. Two spondylodiscitis patients (14%) with complications died of sepsis. Of the 12 remaining patients, 8 were available for follow-up.ConclusionL5 corpectomy is a technically challenging but feasible procedure even though the overall complication rate can be as high as 36%. The radiologic and clinical outcome seems to be better in patients with a small lordosis angle between L4(L3) and S1, since an angle of >50 degrees seems to facilitate cage dislodgement. Anterior plating should be considered in these cases to prevent implant failure.


Global Spine Journal | 2016

Long-term outcome following surgical treatment for spondylodiscitis in 211 cases

Ehab Shiban; Insa Janssen; Bernhard Meyer; Jessica Reiner; Florian Ringel

Aim To determine the safety and efficacy of surgical debridement with instrumentation in treating pyogenic infection of the spine. Material/Methods Between June 2006 and December 2013, 229 consecutive patients suffering from spondylodiscitis were admitted to our department. 211 (92%) underwent surgical debridement and instrumentation while 18 were treated conservatively. Surgically treated patients were analyzed. Clinical outcome was assessed with neurological and laboratory examinations at 3 months following surgery. Long-term clinical outcome was assessed at a minimum of 12 months following surgery with a telephone interview. Results The mean age at presentation was 67 years, 139 patients were male (66%). Distribution of the inflammation was lumbar in 134 (63%), thoracic in 37 (18%) and cervical in 30 (14%) cases. Ten patients (5%) had two concomitant non-contiguous spondylodiscitis in different segments of the spine. Epidural abscess was found in 74 patients (35%). 191 patients (90%) had pain. Neurological deficit was found in 96 patients (45%). In the thoracic and lumbar cases, dorsal instrumentation alone was considered sufficient in 34 cases, additional interbody fusion from dorsal was performed in 86 cases. 360-degree instrumentation was performed in 53 cases. In the cervical cases, ventral spondylodesis was performed in 13 cases and ventral plating, dorsal instrumentation alone in 8 cases and 360-degree instrumentation 13 cases. Postoperative intravenous antibiotics were administered for 13,6 ± 8,2 days followed by 3.0 ± 0.9 months of oral antibiotics. Complete healing of the inflammation was achieved in 204 (97%) of cases. Only 4 patients had a relapse of the inflammation, in 3 cases following dorsal instrumentation alone and in one case after additional interbody fusion with a PEEK cage from dorsal in the lumbar spine. This was followed by debridement and anterior interbody fusion upon relapse. Five patients died due to septic shock (two because of fulminant endocarditis and three by multiple organ dysfunction syndrome). 1 patient died postoperatively due to pulmonary embolism. From the 96 patients with neurological deficit, 44 (46%) had full recovery and 33 (34%) had improved incompletely after surgery. Conclusion Surgical debridement and instrumentation is relatively safe and very effective approach to achieve complete healing of spinal inflammation. Thereby, a short period of intravenous antibiotics of 1–2 weeks is followed by 3 months of oral antibiotics is appropriate in most cases.


The Spine Journal | 2014

Spondylodiscitis by drug-multiresistant bacteria: a single-center experience of 25 cases.

Ehab Shiban; Insa Janssen; Maria Wostrack; Sandro M. Krieg; Monika Horanin; Michael Stoffel; Bernhard Meyer; Florian Ringel


World Neurosurgery | 2017

Total Navigation in Spine Surgery; A Concise Guide to Eliminate Fluoroscopy Using a Portable Intraoperative Computed Tomography 3-Dimensional Navigation System

Rodrigo Navarro-Ramirez; Gernot Lang; Xiaofeng Lian; Connor Berlin; Insa Janssen; Ajit Jada; Marjan Alimi; Roger Härtl


Acta Neurochirurgica | 2014

A retrospective study of 113 consecutive cases of surgically treated spondylodiscitis patients. A single-center experience

Ehab Shiban; Insa Janssen; Maria Wostrack; Sandro M. Krieg; Florian Ringel; Bernhard Meyer; Michael Stoffel


Acta Neurochirurgica | 2016

Safety and efficacy of polyetheretherketone (PEEK) cages in combination with posterior pedicel screw fixation in pyogenic spinal infection

Ehab Shiban; Insa Janssen; Pedro Ribeiro da Cunha; Jessica Rainer; Michael Stoffel; Jens Lehmberg; Florian Ringel; Bernhard Meyer

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Florian Ringel

Technische Universität München

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