Delayed hemorrhage after pediatric stereo-electroencephalography: delayed occurrence or delayed diagnosis?

BACKGROUND: Stereo-electroencephalography (SEEG) is a well-known invasive diagnostic method for drug-resistant epilepsy (DRE). Its rate of complications is relatively low, being the intracranial hemorrhage (ICH) the most relevant. Most centers perform immediate imaging studies after SEEG to rule out complications. However, delayed intracranial hemorrhages (DIH) can occur despite normal imaging studies in the immediate postoperative period. METHODS: We performed a retrospective review of DRE pediatric patients operated on SEEG between April 2016 and December 2020 in our institution. After implantation, an immediate postoperative CT was performed to check electrode placement and rule out acute complications. An additional MRI was performed 24 h after surgery. We collected all postoperative hemorrhages and considered them as major or minor according to Wellmer´s classification. RESULTS: Overall, 25 DRE patients were operated on SEEG with 316 electrodes implanted. Three ICHs were diagnosed on postoperative imaging. Two of them were asymptomatic requiring no treatment, while the other needed surgical evacuation after clinical worsening. The total risk of hemorrhage per procedure was 12%, but just one third of them were clinically relevant. Two hemorrhages were not visible on immediate postoperative CT, being incidentally diagnosed in the 24 h MRI. We recorded them as DIH and are reported in detail. CONCLUSION: Few reports of DIH after SEEG exist in the literature. It remains unclear whether these cases are late occurring hemorrhages or immediate postoperative hemorrhages undiagnosed on initial imaging. According to our findings, we recommend to perform additional late postoperative imaging to diagnose these cases and manage them accurately.

Aortic injury in spine surgery What a spine surgeon needs to know.

Aortic injury is a rare, yet underreported and underestimated complication of spine surgery. Anatomical relation between the aorta and the spine changes under physiological (positional) as well as pathological (deformity) conditions, which puts the aorta at risk of injury during spine surgery. Clinical presentation of aortic injury ranges from asymptomatic perforation of the aorta to acute fatal bleeding. Although several diagnostic methods have been reported, CT-angiography remains an important diagnostic study. Several advancements in the open and the endovascular surgical management have been reported to be successfully used in the management of aortic injury following spine surgery. Management approach of malpositioned screws abutting the aorta is still controversial. Anatomical knowledge and understanding of the previously reported mechanisms of aortic injury are important to be integrated in the preoperative planning process. If the complication occurs, time-to- recognition and to-appropriate-management are important factors for predicting mortality. If unrecognized and untreated in the acutely injured patients, mortality can approach 100%.

Assessment of postoperative acromial and subacromial morphology after arthroscopic acromioplasty using magnetic resonance imaging.

OBJECTIVE: To identify the morphological characteristics of the acromion and subacromial bursal space after arthroscopic acromioplasty using magnetic resonance imaging (MRI). MATERIALS AND METHODS: One hundred patients who received arthroscopic rotator cuff repair and acromioplasty each received at least three MRI examinations (preoperative, first immediate postoperative, and second follow-up imaging between 8 months and 1 year postoperatively). Changes over time in the thickness and morphology of the postoperative acromion as well as the subacromial bursal space were assessed. Clinical and radiological parameters were also analyzed to identify any association with changes in acromial morphology. RESULTS: Despite minimal acromial thinning observed at the first immediate postoperative state, the acromions showed significant thinning at the second postoperative MRI, with a mean reduction of 32%. Along with acromial thinning, an exaggerated concave contour of the acromial undersurface was observed in some patients. In the subacromial space, a loculated fluid collection developed in 91% of the patients at the second postoperative follow-up. No statistically significant association was noted between postoperative acromial thickness change and clinical or radiological factors (P value > 0.05). CONCLUSION: A significant delayed reduction in acromial thickness within approximately 1 year of arthroscopic acromioplasty is thought to be a normal postoperative feature. The simultaneous collection of a loculated, cyst-like fluid in the subacromial bursal space may be an important associated factor of postoperative acromial thinning.

Dual-Energy and Iterative Metal Artifact Reduction for Reducing Artifacts Due to Metallic Hardware: A Loosening Hip Phantom Study.

OBJECTIVE. The purpose of this study was to compare the value of iterative metal artifact reduction (IMAR) with that of dual-energy CT (DECT) and filtered back projection (FBP) CT protocols for reducing metal artifacts and for facilitating visualization of the acetabular cortex in a loosening hip phantom model. MATERIALS AND METHODS. CT scans were obtained with conventional FBP and dual-source CT for two types of hip phantom. For the quantitative study, attenuation was measured by placement of ROIs in the phantoms around the metallic hardware. The differences between mean attenuation in each ROI and the actual attenuation were compared among the three CT protocols. For the qualitative study, the visibility of the acetabular cortex in the artificial loosening area of the total hip arthroplasty model and in the joint space of the bipolar hemiarthroplasty model was evaluated by measurement of the obscured cortical angle. RESULTS. In the quantitative study, attenuation differences in the bipolar hemiarthroplasty model were markedly decreased with IMAR and DECT compared with FBP (p = 0.006-0.007). In the total hip replacement model, attenuation differences were significantly lower with IMAR than with FBP (p < 0.001). In the qualitative study, visibility of the acetabular cortex was markedly improved with IMAR compared with DECT and FBP (p < 0.001) for both hip models. CONCLUSION. CT with IMAR can reduce the distortion caused by metal artifacts more effectively than FBP and DECT can while preserving visibility of the acetabular cortex in both bipolar hemiarthroplasty and total hip arthroplasty phantoms.

The risk factors for residual juvenile nasopharyngeal angiofibroma and the usual residual sites.

OBJECTIVE: Juvenile nasopharyngeal angiofibroma (JNA) is non-metastasizing but potentially locally destructive tumor of the nasopharynx. It can destroy the skull base and invade into the cerebrum. Surgical management is the primary standard but residual disease is always a risk factor. We aimed to determine the risk factors for residual disease and usual sites for these residual tumors. METHODS: The medical records of 131 patients (mean age 17.6 ±â€¯6.8, range 9-71 years) with histologically proven JNA were retrospectively analyzed. The surgeries were all nasal endoscopic approaches, with or without assistant incision. RESULTS: The prevalence of residual disease was 16.8%. Risk factors associated with JNA recurrence included tumor stage, intraoperative bleeding, and the year in which the operation was performed. The pterygoid canal, pterygoid process, and pterygopalatine foramen were the most frequent locations for residual tumor. CONCLUSION: Surgical management should take particular care for the pterygoid canal, petrygoid process, and pterygopalatine foramen. Contrast-enhanced CT and MRI are effective tools to evaluate complete JNA excision in the first two days after primary surgery. Careful exploration of these areas may be the key to avoid residual JNA.

Postoperative Imaging in Anterior Glenohumeral Instability.

OBJECTIVE: Postoperative imaging after surgery for anterior glenohumeral instability poses a great challenge, which can be compounded by a lack of familiarity with the many different operative techniques and their expected normal appearances and complications. In this article, we discuss the postoperative imaging appearances of anterior glenohumeral instability surgery with a review of currently recommended treatment guidelines. CONCLUSION: It is important for radiologists to accurately detect complications of anterior shoulder instability surgery at postoperative imaging.

Postoperative Imaging of the Ankle.

OBJECTIVE: The purpose of this article is to review imaging after commonly encountered surgical interventions of the ligaments, tendons, and soft tissues around the ankle. Intraoperative images, when available, are provided to improve conceptual understanding of these complex procedures. CONCLUSION: Surgical interventions in the ankle are becoming more prevalent with increasing athletic demands and emerging focus on techniques for prevention of joint injury. Knowledge of the surgical techniques, imaging appearances, and complications in the postoperative ankle is necessary for the accurate diagnosis of postoperative complications and for optimal patient care.

MR imaging of soft tissue alterations after total hip arthroplasty: comparison of classic surgical approaches.

OBJECTIVES: To compare soft-tissue changes after total hip arthroplasty with posterior, direct-lateral, anterolateral, or anterior surgical approaches. METHODS: MRI of 120 patients after primary total hip arthroplasty (30 per approach) were included. Each MRI was assessed by two readers regarding identification of surgical access, fatty muscle atrophy (Goutallier classification), tendon quality (0 = normal, 1 = tendinopathy, 2 = partial tear, 3 = avulsion), and fluid collections. Readers were blinded to the surgical approach. RESULTS: Surgical access was correctly identified in all cases. The direct lateral approach showed highest Goutallier grades and tendon damage for gluteus minimus muscle (2.07-2.67 and 2.00-2.77; p = 0.017 and p = 0.001 for readers 1 and 2, respectively) and tendon (2.30/1.67; p < 0.0005 for reader 1/2), and the lateral portion of the gluteus medius tendon (2.77/2.20; p < 0.0005 for reader 1/2). The posterior approach showed highest Goutallier grades and tendon damage for external rotator muscles (1.97-2.67 and 1.57-2.40; p < 0.0005-0.006 for reader 1/2) and tendons (1.41-2.45 and 1.93-2.76; p < 0.0005 for reader 1/2). The anterolateral and anterior approach showed less soft tissue damage. Fluid collections showed no differences between the approaches. CONCLUSIONS: MRI is well suited to identify surgical approaches after THA. The anterior and anterolateral approach showed less soft tissue damage compared to the posterior and direct lateral approach. KEY POINTS: • Identification of the surgical approach is well possible with MR imaging. • Anterolateral/anterior approaches show less soft-tissue damage compared to lateral/posterior approaches. • Posterior approaches show marked damage to external rotator tendons and muscles. • After direct lateral approaches the gluteus minimus tendon/muscle show severe damage.

Reliability of postoperative MR imaging in the determination of level and side of lumbar spinal decompression surgery.

Background Magnetic resonance imaging (MRI) is the diagnostic modality of choice in defining soft tissue compromise of the spinal canal. Purpose To evaluate the reliability of postoperative MRI in the determination of level and side of lumbar spinal decompression surgery, investigated by two reviewers, in different levels of training and specialization. Material and Methods Postoperative MR images of 86 patients who underwent spinal decompression (single level, n = 70; multilevel, n = 16; revision decompression, n = 9) were reviewed independently by an experienced musculoskeletal radiologist and a fourth-year orthopedic surgery resident. The level (single or multiple) and side of previous surgical decompression were determined and compared to the surgical notes. We examined factors that may have influenced the reliability, including demographics, type of surgical decompression, use of a drain, and time interval from surgery to MRI. Results Significantly fewer levels were correctly determined by the resident (77/86 cases, 89.5%) compared with the radiologist (84/86 cases, 97.7%) ( P = 0.014). The resident interpreted significantly more MR images incorrectly in cases where a drain was used (n = 8; P < 0.001). Re-decompression cases were interpreted incorrectly significantly more often by both the radiologist (n = 2, P = 0.032) and the resident (n = 4, P = 0.014). Conclusion Determination of the level and side operated on in previous lumbar spinal decompression surgery on MRI has a high reliability, especially when performed by a musculoskeletal radiologist. However, this reliability is decreased in cases involving surgical drainage and same-level revision surgery.

Subchondroplasty: What the Radiologist Needs to Know.

OBJECTIVE: Subchondroplasty is a novel minimally invasive procedure that is used to treat painful bone marrow lesions in patients with knee osteoarthritis or insufficiency fractures. The objective of this article is to describe the surgical technique and the pre- and postoperative imaging findings of a small case series acquired at a single center. CONCLUSION: The radiologist should be familiar with the anticipated postoperative imaging appearances after subchondroplasty and the potential complications.

[Postoperative spinal column]. / Postoperative Wirbelsäule.

STANDARD PROCEDURE: As a rule, postoperative imaging is carried out after spinal interventions to document the exact position of the implant material. INFORMATION: Imaging is absolutely necessary when new clinical symptoms occur postoperatively. In this case a rebleeding or an incorrect implant position abutting a root or the spinal cord must be proven. In addition to these immediately occurring postoperative clinical symptoms, there are a number of complications that can occur several days, weeks or even months later. These include the failed back surgery syndrome, implant loosening or breakage of the material and relapse of a disc herniation and spondylodiscitis. REVIEW: In addition to knowledge of the original clinical symptoms, it is also important to know the operation details, such as the access route and the material used. RECOMMENDATION: In almost all postoperative cases, imaging with contrast medium administration and corresponding correction of artefacts by the implant material, such as the dual energy technique, correction algorithms and the use of special magnetic resonance (MR) sequences are necessary. RECOMMENDATION: In order to correctly assess the postoperative imaging, knowledge of the surgical procedure and the previous clinical symptoms are mandatory besides special computed tomography (CT) techniques and MR sequences.

Postoperative MRI of the shoulder.

Magnetic resonance imaging (MRI) evaluation of the postoperative shoulder presents technical and diagnostic challenges related to imaging artifacts from hardware and micrometallic shavings, postsurgical scarring, and morphological alterations. Improved visualization of postoperative shoulder anatomy and pathology can be obtained with the use of metal artifact reduction techniques as well as MR arthrography. In this article we review the MR techniques that are designed to address these technical and diagnostic challenges, and we discuss the definitions and indications, normal MRI appearance, and complications of routine surgical procedures for treatment of injuries to the rotator cuff, labral ligamentous complex, and biceps tendon.

In-Hospital Graft Occlusion in Post-Coronary Artery Bypass Grafting Patients in the Early Postoperative Period: A Systematic Review and Meta-Analysis.

Objectives: The objectives of this paper are to evaluate the incidence of early graft occlusion during hospital stays following coronary bypass surgery (CABG) and to assess the factors influencing the odds of in-hospital early graft occlusion. Methods: Reports evaluating the early in-hospital occlusion of coronary bypass grafts were identified through PubMed, Embase, and Cochrane databases. The primary endpoint was to determine the incidence of early graft occlusion following CABG before discharge and to identify and quantify the impact of demographic, clinical, and procedural risk factors on the occurrence of early graft occlusion. The meta-analysis was conducted using a random-effects inverse-variance model with the DerSimonian-Laird estimator, assessing incidence rates, risk factors, and study heterogeneity, with statistical analysis performed using Stata. Results: A total of 22 studies with 35,798 patients were included in the analysis. The overall incidence of in-hospital early graft occlusion was 5% (95% CI: 3% to 7%). In studies using symptom-driven patency assessment, the incidence of occlusion was 2%, whereas in those employing systematic graft patency assessment, it was 6%. Only the presence of a vein graft OR 2.13 (95% CI: 1.19-3.82) was significantly associated with in-hospital graft occlusion. Conclusions: The incidence of in-hospital early graft occlusion seems substantially underestimated if imaging is restricted only to symptomatic patients. Moreover, female gender, increased PI, and the presence of a composite graft could also be potential risk factors for this complication.

Early Postoperative Computed Tomography Scan Air Distribution Predicts Postoperative CSF Leak in Endoscopic Skull Base Surgery.

BACKGROUND: Cerebrospinal fluid (CSF) leak remains the primary concern of endoscopic skull base surgery (ESBS). Pneumocephalus seen in postoperative images has been linked to CSF leak in some reports; however, few studies have looked at the extent to which it is indicative of CSF leak. In the current study, we aim to examine the size and location of post-ESBS pneumocephalus in the early postoperative period and determine their association with postoperative CSF leak. METHODS: Patients undergoing ESBS in a 5-year period were included. All patients underwent brain computed tomography scan within the first 24 postoperative hours. Computed tomography scans were reviewed by a neurosurgeon and a radiologist and have been classified based on the size and location of pneumocephalus. Patients were followed in the postoperative period for clinical signs of CSF leak and managed accordingly. RESULTS: Out of 120 patients, 86 patients met the inclusion criteria. Thirty-five patients (41%) had no pneumocephalus on day one postoperative imaging, while 51 patients (59%) had pneumocephalus with different sizes and distributions. Eleven of 86 patients developed CSF leak. Of the 11 patients, 5 patients (45%) had grade 4 pneumocephalus (P value = 0.02). Patients with multiple locations of pneumocephalus were more likely to develop CSF leak (P value = 0.01). CONCLUSIONS: In post-ESBS patients, both the volume and location of the pneumocephalus are potentially predictive of CSF leak. In patients with a larger volume of intra-axial air and/or multiple air locations, an impending CSF leak should be anticipated.

Impact of Postoperative Imaging Following Emergency Surgery for Penetrating Ballistic Thoracic Trauma.

INTRODUCTION: Patients undergoing emergent surgical procedures after penetrating trauma can benefit from postoperative imaging studies to identify potential missed injuries or indications to additional surgery. Aim of this study is to describe postoperative imaging findings in patients who underwent emergent operation for thoracic gunshot wounds (GSWs) and the subsequent need for further surgery, diagnostic evaluations or consults. METHODS: Patients who survived to receive imaging evaluation after emergency surgery for penetrating chest trauma in a level I trauma center between 2017 and 2021 were included. Results of postoperative diagnostic evaluation were screened to determine their impact on the subsequent management. RESULTS: Overall, 125 patients admitted with a thoracic GSW underwent an emergent surgical procedure and 29 survived to receive postoperative imaging and were included. Postoperative CT-scan was performed in 26 (89.6%) patients, echocardiography in 8 (27.5%). Other tests included esophagoscopy (1) and bronchoscopy (1). Impact on management of abnormal imaging included a new indication to surgery or additional procedures in 7 cases and need for additional imaging or consults in other 8 cases. Bone fractures and lung injuries were more often diagnosed on postoperative CT-scan. In 3 patients, abnormal echocardiographic findings led to a second cardiac operation. CONCLUSION: Following emergency surgery for penetrating trauma, completion of injury assessment with CT-scan can lead to identification of missed or additional injuries, while other imaging is indicated according to operative findings. In this study, 24.1% had additional surgical pathology identified by postoperative imaging while others had findings requiring additional studies or specialist consult evaluations.

Assessment of Navigated Pedicle Screws From Intraoperative Imaging: A Prospective Study of Accuracy and Agreement.

BACKGROUND: Intraoperative (IO) image guidance surgery using 3-dimensional fluoroscopic navigation methods, such as the O-arm system, has improved the accuracy of pedicle screw placement in instrumented spine surgery. IO and postoperative (PO) validation of the implant's correct position from radiological images is a decisive step to ensure patient safety and avoidance of complications related to implant misplacement. In this prospective single-center study, the authors investigated the accuracy and agreement of assessment of pedicle screws from IO O-arm images in comparison to PO computed tomography images. This study aimed to determine whether final evaluation of pedicle screws can safely be conducted from IO images that supersedes the PO computed tomography control. METHODS: A prospective single-center study was carried out at the Spine Unit in the Department of Orthopedics at Umeå University Hospital between 2019 and 2021. All patients enrolled in the study underwent instrumented thoracolumbar spine surgery using navigation. Imaging data were obtained from IO and PO examinations. Four reviewers-2 attending senior spine surgeons, 1 final year resident in orthopedics, and 1 attending neuroradiologist-classified pedicle screws using the Gertzbein and Robbins classification system. Agreement and accuracy of the reviewers were studied to evaluate the assessment of pedicle screws from IO and PO images. RESULTS: A total of 70 patients (422 screws) were included in the study. There was high accuracy among surgeons both on IO and PO images (0.96-0.97, 95% CI [0.94-0.99] and 0.97, 95% CI [0.94-0.99], respectively), and the overall agreement between all raters was 92% to 98% (95% CI [0.90, 1.00]). The discrepancy in assessment between optimal (Group 1) and suboptimal (Group 2) screws between IO and PO images was as low as 1% to 1.7%, which indicates that very few suboptimal screws are missed in the assessment of IO images. CONCLUSIONS: The assessment of navigated pedicle screws using IO images is safe and reliable and may replace the need for further assessment using PO imaging.

Postoperative MRI Visualization of the Cervical Spine Following Cervical Disc Arthroplasty: A Prospective Single-Center Comparison of a Titanium and Cobalt-Chromium Prosthesis.

STUDY DESIGN: Prospective non-randomized single-center cohort study. OBJECTIVES: To analyze the quality of postoperative magnetic resonance imaging of 2 structurally different cervical disc arthroplasty devices at the index and adjacent levels. METHODS: A non-randomized, comparative, prospective, single-center study included 40 patients (23 men and 17 women) aged 32 (26-40) years. Two study groups were utilized: in the first (n = 20), a titanium prosthesis was used; in the second (n = 20), a cobalt-chromium implant was used. Evaluation of MRI studies before and after surgery was performed using sagittal and axial T2 weighted images by 2 specialists who were blinded to the prosthesis that was used. To determine the quality of an MRI image, the classification of Jarvik 2000, the radiological and orthopedic scales for assessing artifacts were used. RESULTS: There was good-to-excellent inter-observer agreement for all of the MR parameters used for the titanium and satisfactory-to-good for the cobalt chromium group. The analysis of the quality of postoperative imaging using the Jarvik 2000 scale showed a statistically significant deterioration in MR images in the cobalt chromium group (P < 0.001), compared to the titanium (P = 0.091). Following a single-level total arthroplasty, the titanium group had better MRI images according to radiological and orthopedic scales (P < 0.001). CONCLUSION: Titanium cervical disc arthroplasty devices result in superior postoperative MR imaging, as compared to cobalt chromium prostheses, as the latter significantly reduces image quality due to the pronounced ferromagnetic effect.

Clinical Utility of Routine Postoperative Imaging in Spinal Fusion Surgery: A Systematic Review.

OBJECTIVE: Following spinal fusion surgery, routine imaging is often obtained in all patients regardless of clinical presentation. Such routine imaging may include x-ray, computed tomography, or magnetic resonance imaging studies in both the immediate postoperative period and after discharge. The clinical utility of this practice is questionable. Our goal is to assess the existing literature for evidence of impact on clinical care from routine radiographic surveillance following spinal fusion. METHODS: A systematic search of Embase, Scopus, PubMed, Cochrane, and Ovid databases was performed for studies investigating postoperative imaging following spinal fusion surgery. Studies were analyzed for imaging findings and rates of change in management due to imaging. RESULTS: In total, the review identified 9 studies that separated data by unique patient or by unique clinic visits. The 4 studies reporting per-patient data totaled 475 patients with 328 (69%) receiving routine imaging. Among these, 28 (8.5%) patients had abnormal routine findings with no patients having a change to their clinical course. Of the 5 studies that reported clinic visit data, 3119 patient visits were included with 2365 (76%) clinic visits accompanied by imaging. Across these 5 studies, 146 (6.2%) visits noted abnormal imaging with only 12 (0.5%) subsequent management changes. CONCLUSIONS: Our analysis found that routine imaging after spinal fusion surgery had no direct benefit on clinical management. The utility of baseline imaging for long-term comparison and medicolegal concerns were not studied and remain up to the provider's judgment. Further research is necessary to identify optimal imaging criteria following spinal fusion surgery.

Fusion of Preoperative and Postoperative Imaging May Predict the Diagnostic Yield of Stereotactic Needle Brain Biopsies.

BACKGROUND: Stereotactic needle brain biopsy is a commonly used neurosurgical procedure. However, up to 15% of biopsies result in undiagnostic pathology reports. Repeat biopsy or continued management without a diagnosis are often considered after undiagnostic biopsies. There have been no reports about the role of postoperative imaging in predicting the diagnostic yield of stereotactic biopsies. METHODS: We retrospectively assessed all stereotactic biopsies performed over an 11-year period. We performed fusion of immediate postoperative computed tomography (CT) with preoperative MRI, to document whether the air bubble in the postoperative CT was located within the targeted lesion. We then evaluated the association of this fusion-based accuracy assessment with the diagnostic yield of the biopsy. RESULTS: Fewer than 5% of biopsies did not have an air bubble on postoperative CT. A total of 226 biopsies were performed for 219 patients. In our sample, 213 of 226 biopsies were accurate (94.2% accuracy rate), and 203 of 226 biopsies gave a definitive diagnosis (89.8% diagnostic rate). In those cases where the fusion was accurate, the diagnostic rate was 93.9%. When the fusion was inaccurate, the diagnostic rate was only 23.1% (odds ratio 51.5, 95% confidence interval 12.6-210.44, P < 0.001). Of all patient, imaging, surgical, and admission parameters, the only parameter that correlated with diagnostic outcome of the biopsy was the fusion construct accuracy. CONCLUSIONS: Fusion of immediate postoperative CT with preoperative imaging is predictive of the diagnostic rate. In cases where the pathology report following a biopsy is not diagnostic, this fusion may be useful in making decisions regarding repeat biopsy or considering other diagnostic options.

The 2023 Stone-Free CT Mandate: Addressing the Two Sides of the Debate.

To the editors of the Journal of Endourology, we write to express our reservations in the recent announcement that starting in 2023 all reporting of stone-free rates be based on CT.