Surgical management of isthmic spondylolisthesis: A comparative study of postoperative outcomes between ALIF and TLIF.

INTRODUCTION: Circumferential fusion by the anterior (ALIF) or transforaminal (TLIF) approach combined with posterior instrumentation is currently used for the surgical treatment of low-grade isthmic spondylolisthesis. But few studies have compared the clinical and radiological outcomes of various interbody fusion techniques. The objective of this study was to compare the clinical and radiological results at 2 years postoperative of two fusion techniques-TLIF versus ALIF plus posterior instrumentation-for low-grade isthmic spondylolisthesis in adults. MATERIALS AND METHODS: This was an observational multicenter study done at nine French healthcare facilities specialized in spine surgery. The inclusion criteria were minimum age of 18 years, grade 1-3 isthmic spondylolisthesis, ALIF+posterior fixation (ALIF+PS) or TLIF, minimum follow-up of 2 years. Clinical and radiological evaluations were done preoperatively and at 2 years of follow-up. A lumbar CT scan was done at 1 year postoperative to evaluate fusion. RESULTS: The cohort consisted of 89 patients (50 women, 39 men) with a mean age of 47.7±12.3 (18-79) years. The patients in the ALIF groups (n=71) had a significantly longer hospital stay than those in the TLIF group (n=18): 5.7 days versus 4.6 days (p=.04). However, their medical leave from work was significantly shorter: 31.0 weeks versus 40.7 (p=.003). Lumbar pain VAS diminished faster in the ALIF groups, with a significantly larger drop than the TLIF group in the first 3 months postoperative. Only the increase in lumbar disc lordosis was larger in the ALIF group: 11.7°±12.0° versus 6.0°±11.7° (p=.036). There was a significant correlation between the increase in global lordosis and reduction in lumbar VAS at 2 years postoperative (ρ=-0.3295; p=.021). CONCLUSION: ALIF+PS provides a faster relief of postoperative low back pain than TLIF but there are no significant clinical differences between techniques at 2 years of follow-up. Despite better restoration of disc lordosis in the ALIF+PS group, there was no difference in the restoration of global lordosis. LEVEL OF EVIDENCE: III; multicenter comparative study.

Fusion and clinical outcomes of lumbar interbody fusion for low-grade isthmic spondylolisthesis.

INTRODUCTION: Low-grade isthmic spondylolisthesis (ISPL) is generally treated by circumferential fusion with interbody graft, although there is no consensus on technique. HYPOTHESIS: The various interbody fusion strategies provide satisfactory fusion rates and clinical results. METHODS: A multicenter retrospective study analyzed lumbar interbody fusion for low-grade ISPL performed between March 2016 and March 2019. Techniques comprised: circumferential fusion on a posterior or a transforaminal approach (PLIF, TLIF: n=57), combined anterior (ALIF)+posterolateral fusion (ALIF+PLF: n=60), and ALIF+percutaneous posterior fixation (ALIF+PPF: n=55). Function was assessed on a lumbar and a radicular visual analog scale (AVS-L, VAS-R), Oswestry Disability Index (ODI) and Short Form 12 (SF12). RESULTS: Among the 129 patients, 85.3% showed fusion (Lenke 1 or 2), with no significant differences between the ALIF-PLF or ALIF-PPF groups and the PLIF or TLIF groups (p=0.3). Likewise, there was no difference in fusion rates between the ALIF-PPF and ALIF-PLF subgroups (p=0.28). VAS-L (p<0.001) and VAS-R (p<0.0001), ODI (p<0.001) and SF12 physical (PCS) (p<0.01) and mental component sores (MCS) (p<0.001) all showed significant improvement at 12months. Combined approaches provided greater clinical efficacy than TLIF or PLIF for lumbar (p<0.0001) and radicular pain (p<0.05), ODI (p<0.0001) and SF12 PCS (p<0.01). At 12months, there was no clinical difference between the ALIF-PPF and ALIF-PLF subgroups. However, patents with interbody non-union (Lenke 3 or 4) had lower SF12 PCS scores (p<0.004) and VAS-L ratings (p<0.001) than Lenke 1-2 patients. CONCLUSION: Low-grade ISPL treated by circumferential arthrodesis and interbody graft showed 85.3% consolidation at 2years, with equivalent outcomes between anterior and posterior techniques. Successful fusion was associated with better clinical results. LEVEL OF EVIDENCE: IV.

Spatial analysis of the glioblastoma proteome reveals specific molecular signatures and markers of survival.

Molecular heterogeneity is a key feature of glioblastoma that impedes patient stratification and leads to large discrepancies in mean patient survival. Here, we analyze a cohort of 96 glioblastoma patients with survival ranging from a few months to over 4 years. 46 tumors are analyzed by mass spectrometry-based spatially-resolved proteomics guided by mass spectrometry imaging. Integration of protein expression and clinical information highlights three molecular groups associated with immune, neurogenesis, and tumorigenesis signatures with high intra-tumoral heterogeneity. Furthermore, a set of proteins originating from reference and alternative ORFs is found to be statistically significant based on patient survival times. Among these proteins, a 5-protein signature is associated with survival. The expression of these 5 proteins is validated by immunofluorescence on an additional cohort of 50 patients. Overall, our work characterizes distinct molecular regions within glioblastoma tissues based on protein expression, which may help guide glioblastoma prognosis and improve current glioblastoma classification.

Diagnosis of reoperated cervical non-union: Multicenter retrospective study about 45 patients.

INTRODUCTION: Non-union is one of the main complications of single- or multi-level cervical spine fusion, considerably impairing functional results. The aim of this study was to evaluate the respective contributions of imaging examinations in the diagnostic process, the challenge being to avoid inappropriate surgery and unnecessary complementary examinations. MATERIAL AND METHOD: A retrospective multicenter study included all patients managed for cervical spine non-union between 2008 and 2018. We evaluated the imaging examinations performed on each patient and determined signs of non-union in each image. RESULTS: The study included 45 patients in 4 centers: 55% female; mean age, of 48±8.0 years; 57% smokers. Systematic static radiography showed signs of non-union in 55% of cases. Dynamic X-ray was performed in 34% of patients, and showed hypermobility of the level in 80% of cases. CT supported diagnosis of non-union in 97% of cases, and MRI in 48%. SPECT-CT was positive in all cases of non-union. DISCUSSION: Dynamic X-ray is rarely prescribed, but frequently provided an objective measure of hypermobility of the level in non-union, justifying first-line use. Millimetric-slice CT was reliable for diagnosis. MRI is relevant only once diagnosis has been made, as part of preoperative work-up. Nuclear imaging can be useful in order to solve doubtful cases. CONCLUSION: In suspected cervical spine non-union, we recommend dynamic X-rays (flexion/extension) and CT-scan as first-line diagnosis examinations. LEVEL OF EVIDENCE: IV.

French Spine Surgery Society guidelines for management of spinal surgeries during COVID-19 pandemic.

Since the outbreak of coronavirus disease 2019 (COVID-19) in December 2019 in China, various measures have been adopted in order to attenuate the impact of the virus on the population. With regard to spine surgery, French physicians are devoted to take place in the national plan against COVID-19, the French Spine Surgery Society therefore decided to elaborate specific guidelines for management of spinal disorders during COVID-19 pandemic in order to prioritize management of patients. A three levels stratification was elaborated with Level I: Urgent surgical indications, Level II: Surgical indications associated to a potential loss of chance for the patient and Level III: Non-urgent surgical indications. We also report French experience in a COVID-19 cluster region illustrated by two clinical cases. We hope that the guidelines formulated by the French Spine Surgery Society and the experience of spine surgeons from a cluster region will be helpful in order optimizing the management of patients with urgent spinal conditions during the pandemic.

Which functional outcome parameters correlate better with elderly patients' satisfaction after non-fusion lumbar spine surgery?

BACKGROUND: Elderly patients are increasingly operated for spinal degenerative diseases. The treatment objective is quality of life, which, in this population, is difficult to assess. Hence, patient satisfaction, although less objective, is of high importance. In this study, we have examined the relation of various functional parameters after non-fusion spinal surgery, with patient satisfaction. METHODS: A 5-year follow-up after non-fusion lumbar spine surgery on 185 elderly patients was performed. Demographics, co-morbidity factors, type of lesion and operation performed were recorded. The Oswestry Disability Index (ODI) was calculated. Also, walking distance, use of analgesics, daily activities, social life and patient mobility were assessed by means of study-specific stratified pain-independent questionnaires. Finally, patient satisfaction was assessed by the single-item satisfaction question. RESULTS: Postoperative ODI, and the improvement regarding ODI, analgesic use and walking distance indices were independent factors influencing patient satisfaction. The insertion of pain analog scale score into this model altered the results, and along with this score, only the walking distance improvement remained an independent statistically significant factor. When the independent from pain scales were used, the improvement of the walking distance score were independently related to the satisfaction of the elderly. CONCLUSIONS: ODI is applicable in elderly patients, even with the exception of some of the categories assessed. Walking capacity should be assessed separately from other pain-dependent activities; its improvement should be an independent goal of lumbar spine surgery in the elderly. The level of the elderly patient subjectivity in auto-assessing the outcome of lumbar spine surgery is high, and objective outcome measurements remain important.

Contribution of Dynamic Surgical Guidance to the Accurate Placement of Pedicle Screws in Deformity Surgery: A Retrospective Case Series.

OBJECTIVE: We assessed the contribution of a dynamic surgical guidance (DSG) probe in the accurate placement of thoracic and lumbar pedicle screws (PSs) in patients with spinal deformity. METHODS: A retrospective review was performed of 98 patients (104 procedures) with various spinal deformities, who had received posterior instrumentation with PSs inserted using either DSG or the conventional free-hand (FH) technique. A total of 882 PSs were inserted using DSG (DSG group) and 603 using the FH technique (FH group). The DSG probe was preferably chosen for large osteosyntheses and severe deformities. Two neurosurgeons, unaware of the surgical groups, reviewed all the intraoperative computed tomography scans and assessed all the PS placements. RESULTS: Of the PSs used, 95.4% in the DSG group and 92.2% in the FH group were correctly placed (P = 0.0136). The difference in screw placement accuracy was greater at the thoracic level (DSG group, 92.5%; vs. FH group, 87.0%; P = 0.0310) than at the lumbar level (DSG group, 98.0%; vs. FH group, 95.4%; P = 0.0385). Severe (>4 mm) lateral breaches occurred in 24 cases (4.0%) in the FH group but in only 5 (0.6%) in the DSG group (P < 0.0001). No severe medial breach was observed in either group. CONCLUSIONS: Despite having more patients with severe deformities in the DSG group, PS insertion was significantly more accurate with DSG. This technique also reduced the severe unacceptable lateral misplacement rate (>4 mm) and, consequently, the incidence of intraoperative screw revisions even in patients with severe deformities.

Retrospective multicenter study by the French Spine Society of surgical treatment for spinal metastasis in France.

INTRODUCTION: The occurrence of spinal metastasis is a turning point in the progression of cancer. The optimal management has not been well defined. The aim of this study was to identify the various treatments currently being used in France and to determine the benefits of surgical treatment. MATERIAL AND METHODS: The records of patients treated between 2011 and 2015 at seven spine surgery centers in France were reviewed retrospectively. The pain level (VAS), McAfee scale, walking ability and Frankel Grade were evaluated at inclusion and at 6-months postoperative. The Tomita and Tokuhashi prognostic scores were also determined. RESULTS: The cohort consisted of 319 patients. Preoperatively, 63.5% of patients could walk without assistance and 66% were Frankel Grade E. Twenty percent of patients were bed-ridden according to the Karnofsky Performance Status. According to the Tokuhashi criteria, 44% were predicted to have less than 6 months to live. The Tomita score recommended palliative surgery in 48% of cases. Potentially unstable lesions were present in 67% of patients. The surgical indication was made because of a neurological deficit in 40% of cases, to alleviate pain in 30% of cases, and for an instability in 30% of cases. Spinal cord decompression and posterior fixation were the most common procedures. The overall complication rate was 38.6%. At 6-months postoperative, 24 patients had died of the 245 available for review. Only 13 patients could not walk (5.3%), 69.4% of patients were Frankel Grade E and pain levels were significantly lower that preoperatively (2.4 vs. 4.6, p<0.001). DISCUSSION: This study's findings are evidence of the difficulties encountered when treating spinal metastases. The main prognostic scores do not appear to be valid for these patients. A large number of patients were operated urgently because of a neurological deficit, before the treatment could be discussed in a multidisciplinary team (MDT) meeting. Nevertheless, the surgical treatment of these patients is associated with an acceptable complication rate and clinical improvement. CONCLUSION: Surgical treatment of spinal metastases is not well standardized; thus many different strategies are used. There is evidence that it improves the quality of life in most patients by reducing their pain and allowing them to walk again. However, this treatment must be discussed in the context of an MDT meeting before it is carried out. These patients should be evaluated early on by a spine surgeon to reduce the need for emergency surgery when a neurological deficit appears.

Surgeon's and patient's radiation exposure during percutaneous thoraco-lumbar pedicle screw fixation: A prospective multicenter study of 100 cases.

HYPOTHESIS: Percutaneous pedicle screw fixations (PPSF) are increasingly used in spine surgery, minimizing morbidity through less muscle breakdown but at the cost of intraoperative fluoroscopic guidance that generates high radiation exposure. Few studies have been conducted to measure them accurately. MATERIAL AND METHODS: The objective of our study is to quantify, during a PPSF carried out in different experimented centers respecting current radiation protection recommendations, this irradiation at the level of the surgeon and the patient. We have prospectively included 100 FPVP procedures for which we have collected radiation doses from the main operator. For each procedure, the doses of whole-body radiation, lens and extremities were measured. RESULTS: Our results show a mean whole body, extremity and lens exposure dose per procedure reaching 1.7±2.8µSv, 204.7±260.9µSv and 30.5±25.9µSv, respectively. According to these values, the exposure of the surgeon's extremities and lens will exceed the annual limit allowed by the International Commission on Radiological Protection (ICRP) after 2440 and 4840 procedures respectively. CONCLUSION: Recent European guidelines will reduce the maximum annual exposure dose from 150 to 20mSv. The number of surgical procedures to not reach the eye threshold, according to our results, should not exceed 645 procedures per year. Pending the democratization of neuronavigation systems, the use of conventional fluoroscopy exposes the eyes in the first place. Therefore they must be protected by leaded glasses. LEVEL OF PROOF: IV, case series.

Case Report: Hemianopia: From Suspected Glioblastoma to the Diagnosis of Ectopic Schistosomiasis Haematobium Infection in a Traveler Returning from the Republic of the Congo.

Schistosomiasis due to Schistosoma haematobium is a widespread disease usually affecting the urinary tract associated with hematuria and kidney disorders. Neurological damage is rarely reported and symptoms are nonspecific and may suggest brain tumors such as glioma. We describe the first double ectopic haematobium schistosomiasis case involving the brain and intestine.

Evaluation of the Relevance of Surgery in Patients with Multiple Myeloma Harboring Symptomatic Spinal Involvement: A Retrospective Case Series.

BACKGROUND: Multiple myeloma spinal involvement can lead to bone fractures and neurologic impairment that can severely alter quality of life. The role of surgery is controversial, given its high morbidity, and the lack of evidence. We hereby aim to evaluate efficacy and safety of surgery in the management of symptomatic spinal lesions in patients with multiple myeloma. METHODS: We included all patients operated on for a myeloma-related spinal lesion in our institution between 2007 and 2015. Demographic, clinical, and surgical data were collected as well as hematologic profiles. We retrospectively assessed the surgical success of the procedures, if at 3 months the patient fulfilled the following 4 criteria: pain relief, ability to walk, spinal stability, and no relevant morbidity. RESULTS: Thirty-six men and 19 women, with a median age of 62 years, were included. Seventeen patients underwent an emergency intervention, whereas 38 patients underwent elective surgery. At 3 months, 88.2% and 96.1%, respectively, of patients experienced pain relief and were able to walk. Spinal stability was considered satisfactory for 94.1% of patients. We reported 8 major complications in 8 patients. Altogether, 34 patients (61.8%) fulfilled all criteria for surgical success. An International Staging System score of 1 and the absence of previous chemotherapy were significantly associated with surgical success. CONCLUSIONS: Management of myeloma-related spine lesions requires a multidisciplinary approach. Surgery rapidly provides both decompression and stabilization. Using a strict patient-specific evaluation, we reported rewarding functional results, with acceptable morbidity. Surgery for multiple myeloma vertebral lesions seems to be a valuable option for carefully selected patients.

Minimally invasive resection of large dumbbell tumors of the lumbar spine: Advantages and pitfalls.

OBJECTIVES: The surgical management of dumbbell tumors of the lumbar spine remains controversial, because of their large volume and complex location, involving both the spinal canal and the retro peritoneum. While sporadically reported, our study aims to confirm the value of minimally invasive posterior access for the complete resection of large lumbar dumbbell tumors. PATIENTS AND METHODS: In this prospective study, we included all consecutive patients who underwent the resection of a voluminous dumbbell tumor at the lumbar spine through a minimally invasive approach, between March 2015 and August 2017. There were 4 men and 4 women, with a mean age at diagnosis of 40.6 years (range 29-58 years). The resection was performed through a trans muscular tubular retractor by the same surgical team. Operative parameters and initial postoperative course were systematically reported. Clinical and radiological monitoring was scheduled at 3 months, 1 year and 2 years. RESULTS: The mean operative time was 144 min (range 58-300 minutes) and the mean estimated blood loss was 250 ml (range 100-500 ml). Gross total resection was achieved in all patients. No major complication was reported. The mean length of hospital stay was 3.1 days (range 2 to 6 days). Histological analysis confirmed the diagnosis of grade 1 schwannoma in all patients. The mean follow up period was 14.9 months (range 6 to 26 months), and 5 patients completed at least 1-year follow-up. At 6 months the Macnab was excellent in 6 patients, good in one patient and fair in one patient because of residual neuropathic pain requiring the maintenance of a long-term treatment. No tumor recurrence was noted to date. CONCLUSION: Lumbar dumbbell tumors can be safely and completely resected using a single-stage minimally invasive procedure, in a trained team.

Surgical site infection in spinal metastasis: incidence and risk factors.

BACKGROUND: Surgical site infection (SSI) in spinal metastasis surgery represents the most common postoperative surgical complication with high morbidity and mortality. OBJECTIVE: This study aims to evaluate the incidence of SSI in spinal metastasis surgery and its risk factors. STUDY DESIGN: This is a retrospective analysis of a prospectively collected data. METHODS: Preoperative, operative, and postoperative data were collected together with the modified Tokuhashi score and Frankel score at all time checkpoints. Surgical site infection was divided into superficial and deep SSI, as well as early (<90 days) and late SSI. Multiple logistic regression analysis was performed to identify independent risk factors, with p<.05 as significance threshold. RESULTS: A total of 297 patients were included, with an incidence of SSI of 5.1% (superficial SSI: 3.4%; deep SSI: 1.7 %). Cervicothoracic surgery was associated with the highest incidence of SSI, whereas cervical surgery had the lowest incidence. Smoking, higher number of spinal metastasis, elevated body mass index (BMI), and higher ASA (American Society of Anesthesiologist) score were the preoperative factors associated with increased risk of SSI. Increased intraoperative blood loss and increased number of fixed vertebra increased the SSI incidence. SSI increased hospital stay by a mean of 12 days. When all these variables are analyzed in a multiple regression model, only surgical time≥4 hours and ASA≥3 were found to be independent risk factors for the occurrence of SSI. CONCLUSION: This paper represents the largest series of spinal metastasis with a mean incidence of SSI of 5.1%. Smoking, higher BMI, higher number of spinal metastasis, higher ASA score, higher number of fused vertebra, intraoperative bleeding≥2000 mL, and neurologic deterioration are risk factors for SSI occurrence. Only ASA≥3 and operative duration≥4 hours are independent risk factors for this complication occurrence. Finally, SSI occurrence is associated with increased hospital stay, increased 30-day mortality rate, and decreased survival rates.

Decision Making for the Surgical Treatment of Vertebral Metastases Among Patients with Short Predicted Survival.

BACKGROUND: A wide spectrum of treatment choices is proposed for poor-prognosis patients with vertebral metastases. The continuous increase of this population and the propagation of less invasive techniques necessitate further study concerning which patients could benefit from palliative surgery. METHODS: All patients with a Tokuhashi score ≤8 who had undergone palliative surgical treatment for vertebral metastasis within 4 years were retrospectively reviewed. Demographics, clinical characteristics, and data concerning the disease and the operation were recorded. Patients were assessed on discharge and at 2 months concerning eventual benefit from surgery, based on pain measurements, motor function (Frankel grade), spinal stability assessment, and complications. Statistical analysis was performed to detect possible interrelations. RESULTS: Eighty-eight patients were reviewed. The average age was 56.5 years. The mean Tokuhashi score was 5.9, and the mean Karnofsky score was 56.4. Thirty-six patients experienced immediate improvement, 12 were lost to follow-up, and 42 were found to have benefited from surgery 2 months later. High Karnofsky score, radicular pain, morphine use, absence of complications, and immediate improvement predicted benefit from surgery. CONCLUSIONS: Decision making for a patient with poor prognosis concerning eventual surgery for a vertebral metastasis should be based mainly on the patient's clinical presentation; the primary cancer site is of less importance.

Chemical meningitis related to intra-CSF liposomal cytarabine.

Therapeutic options of leptomeningeal metastases include intra-cerebrospinal fluid (CSF) chemotherapy. Among intra-CSF agents, liposomal cytarabine has advantages but can induce specific toxicities. A BRAF-V600E-mutated melanoma leptomeningeal metastases patient, treated by dabrafenib and liposomal cytarabine, presented after the first injection of liposomal cytarabine with hyperthermia and headaches. Despite sterile CSF/blood analyses, extended intravenous antibiotics were given and the second injection was delayed. The diagnosis of chemical meningitis was finally made. Dose reduction and appropriate symptomatic treatment permitted the administration of 15 injections of liposomal cytarabine combined with dabrafenib. A confirmation of the diagnosis of chemical meningitis is essential in order (1) not to delay intra-CSF or systemic chemotherapy or (2) to limit the administration of unnecessary but potentially toxic antibiotics.

Long-segment percutaneous screw fixation for thoraco-lumbar spine metastases: a single center's experience.

BACKGROUND: The management of spine metastases is an increasing concern for spine surgeons. Their treatment is mainly palliative with the goal to preserve or restore the patients' quality of life. Many minimally invasive techniques have been introduced with the aim to reduce the morbidity associated with more traditional open approaches. We aimed to evaluate the efficiency of long segment percutaneous pedicle screw stabilization for the treatment of instability associated with symptomatic thoracolumbar spine metastases. METHODS: In this prospective study, we included all patients who underwent the percutaneous placement of pedicle screws in our institution between January 2008 and June 2014, for the palliative treatment of a symptomatic thoracolumbar spine metastasis. All patients had a normal examination. Postoperative radiation therapy was planned within 2 weeks following the stabilization. A clinical and radiological follow-up were planned at 3 months, 6 months and 1 year. Pain was measured using VAS and functional status was assessed using the Frankel Grading system. CT scan was performed before discharge and at each office evaluation. RESULTS: Forty-four patients have been included. There were 26 men and 18 women, with a mean age of 57.3 years (range 36-79 years). The mean operative time was 85 minutes (range 47-124 min), and the estimated blood loss was inferior to 100 mL in all cases. The mean length of hospital stay was 5.2 days (range 3-18 days). All patients underwent postoperative radiation therapy within 2 weeks. Pain was significantly improved from the early postoperative period (P<0.001). Visual Analogic Scale scores decreased from 6.3 (2-10) to 3.0 (0-6) at discharge. No patient worsened his neurological condition postoperatively. One patient required a revision surgery at 3 months due to an important tumor progression at the treated level. Radiological follow-up demonstrated no case of misplacement, hardware breakage or loosening. CONCLUSIONS: As the treatment of spine metastases is largely palliative, minimally invasive techniques should be discussed first to limit the impact of surgery in critical patients. Long-segment percutaneous screw fixation followed by early radiation therapy, appears to be a safe and effective treatment option to ensure solid and durable stability, as well as a good local tumor control.

Minimally invasive costotransversectomy for the resection of large thoracic dumbbell tumors.

BACKGROUND: Due to their important size and complex localization, the management of thoracic dumbbell tumors is challenging, frequently requiring the need for an anterior approach. Our study aims to first report the feasibility and safety of a single-stage posterior minimally invasive procedure in achieving complete resection of voluminous thoracic dumbbell tumors. METHODS: We retrospectively reviewed the medical records of five consecutive patients, who underwent the minimally invasive resection of a type III thoracic dumbbell tumor in our institution between March 2007 and March 2012. There were two men and three women, with a mean age at diagnosis of 57 years (range 41-68 years). After the placement of a non-expandable tubular retractor under fluoroscopic control, a costotransversectomy was achieved. By moving the retractor in all directions, the tumor was largely exposed and resected with the cavitron ultrasonic surgical aspirator. Clinical and radiological monitoring was performed before discharge, at 6 months, 1 year and 2 years. RESULTS: No major intraoperative complication was reported. Gross total resection was achieved in four patients. The mean operative time was 219 mins (range 75-540 mins) and the mean estimated blood loss was 230 ml (range 50-500 ml). No postoperative complication was reported. The mean length of hospital stay was 3.6 days (range 2-6 days) and all patients were discharged home. Histological analysis confirmed the diagnosis of grade 1 schwannoma in four patients and revealed a hemangiopericytoma in one patient. No tumor recurrence was noted with a mean follow up period of 46 months (range 32-54 months). CONCLUSION: Thoracic dumbbell tumors can be safely and completely resected using a single-stage minimally invasive procedure. The costotransversectomy can be performed through a non-expandable retractor allowing sufficient access to all parts of the tumor.

Evaluation of non-supervised MALDI mass spectrometry imaging combined with microproteomics for glioma grade III classification.

An integrated diagnosis using molecular features is recommended in the 2016 World Health Organization (WHO) classification. Our aim was to explore non-targeted molecular classification using MALDI mass spectrometry imaging (MALDI MSI) associated to microproteomics in order to classify anaplastic glioma by integration of clinical data. We used fresh-frozen tissue sections to perform MALDI MSI of proteins based on their digestion peptides after in-situ trypsin digestion of the tissue sections and matrix deposition by micro-spraying. The generated 70µm spatial resolution image datasets were further processed by individual or global segmentation in order to cluster the tissues according to their molecular protein signature. The clustering gives 3 main distinct groups. Within the tissues the ROIs (regions of interest) defined by these groups were used for microproteomics by micro-extraction of the tryptic peptides after on-tissue enzymatic digestion. More than 2500 proteins including 22 alternative proteins (AltProt) are identified by the Shotgun microproteomics. Statistical analysis on the basis of the label free quantification of the proteins shows a similar classification to the MALDI MSI segmentation into 3 groups. Functional analysis performed on each group reveals sub-networks related to neoplasia for group 1, glioma with inflammation for group 2 and neurogenesis for group 3. This demonstrates the interest on these new non-targeted large molecular data combining both MALDI MSI and microproteomics data, for tumor classification. This analysis provides new insights into grade III glioma organization. This specific information could allow a more accurate classification of the biopsies according to the prognosis and the identification of potential new targeted therapeutic options. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.