Initial experience, feasibility, and technical development with an electromagnetic navigation assistance in percutaneous pelvic bone cementoplasty: retrospective analysis.

OBJECTIVES: To assess the feasibility and technical outcomes of pelvic bone cementoplasty using an electromagnetic navigation system (EMNS) in standard practice. MATERIALS AND METHODS: Monocentric retrospective study of all consecutive patients treated with cementoplasty or reinforced cementoplasty of the pelvic bone with EMNS-assisted procedures. The endpoints were periprocedural adverse events, needle repositioning rates, procedure duration, and radiation exposure. RESULTS: A detailed description of the technical steps is provided. Thirty-three patients (68 years ± 10) were treated between February 2016 and February 2020. Needle repositioning was required for 1/33 patients (3%). The main minor technical adverse event was soft tissue PMMA cement leaks. No major adverse event was noted. The median number of CT acquisitions throughout the procedures was 4 (range: 2 to 8). Radiation exposure and mean procedure duration are provided. CONCLUSION: Electromagnetic navigation system-assisted percutaneous interventions for the pelvic bone are feasible and lead to low rates of minor technical adverse events and needle repositioning. Procedure duration and radiation exposure were low. KEY POINTS: • Initial experience for 33 patients treated with an electromagnetic navigation assistance for pelvic cementoplasty shows feasibility and safety. • The use of an electromagnetic navigation system does not expose to high procedure duration or radiation exposure. • The system is efficient in assisting the radiologist for extra-axial planes in challenging approaches.

Percutaneous alcohol embolization and vertebroplasty of a T2 aggressive vertebral hemangioma with prior embolization of dangerous arterial anastomoses.

Aggressive vertebral hemangiomas usually exhibit extraosseous expansion that can result in spinal cord or radicular compression.1 In symptomatic cases, treatment by alcohol embolization and percutaneous vertebroplasty has been reported as feasible, safe, and effective with long-term benefits on neurological symptoms.2 Safety rules before vertebral alcohol embolization include preoperative spinal cord vascularization mapping and opacification through bone needles to assess the absence of dangerous intratumoral anastomoses.In video 1 we present a case of a symptomatic T2 aggressive vertebral hemangioma with dangerous anastomoses between the lesion and both supreme intercostal arteries (SIAs). Embolization by the arterial route of both SIAs was performed, which required good anatomic knowledge of the spinal cord vascularization at the cervicothoracic junction3 4 as a cervical radiculomedullary artery arose from the left costocervical trunk which also fed the left SIA. After occlusion of all dangerous arterial anastomoses, we were able to successfully perform T2 alcohol embolization and percutaneous vertebroplasty. neurintsurg;15/7/728/V1F1V1Video 1Case presentation.

The "Eiffel Tower" technique: novel long-axis sacroplasty under electromagnetic navigation assistance; feasibility and descriptive study.

OBJECTIVES: To describe a novel long-axis multimodal navigation assisted technique - the so-called Eiffel Tower technique - aimed at integrating recent technological improvements for the routine treatment of sacral insufficiency fractures. MATERIALS AND METHODS: The long-axis approach described in the present study aimed at consolidating the sacral bone according to biomechanical considerations. The purpose was (i) to cement vertically the sacral alae all along and within the lateral fracture lines, resembling the pillars of a tower, and (ii) to reinforce cranially with a horizontal S1 landing zone (or dense central bone) resembling the first level of the tower. An electromagnetic navigation system was used in combination with CT and fluoroscopic guidance to overtop extreme angulation challenges. All patients treated between January 2019 and October 2021 in a single tertiary center were retrospectively reviewed. RESULTS: A description of the technique is provided. Twelve female patients (median age: 80 years [range: 32 to 94]) were treated for sacral insufficiency fractures with the "Eiffel Tower" technique. The median treatment delay was 8 weeks (range: 3 to 20) and the initial median pain assessed by the visual analogue scale was 7 (range: 6 to 8). Pain was successfully relieved (visual analogue score < 3) for 9 patients (75%) and persisted for 2 patients (17%). One patient was lost during the follow-up. No complication was noted. CONCLUSION: The "Eiffel Tower" multimodal cementoplasty integrates recent technological developments, in particular electromagnetic navigation, with the purpose of reconstructing the biomechanical chain of the sacral bone. KEY POINTS: • Sacral insufficiency fractures are common and can be efficiently treated with percutaneous sacroplasty. • The long axis sacroplasty approach can be challenging given both the shape of the sacral bone and the angulation to reach the target lesion. • The "Eiffel Tower" technique is a novel approach using electromagnetic navigation to expand the concept of the long axis route, adding a horizontal S1 landing zone.

Extraction of cement leakages and malpositioned spindles complicating percutaneous interventions: why, when and how?

OBJECTIVES: Cement leakages in soft tissues are a common occurrence during cementoplasty. They may cause chronic pain, and thus treatment failure. Spindle malposition during reinforced cementoplasty may cause vascular, nerve or cartilage injury. Our goal was to evaluate the rate of cement leakage/spindle extraction and describe the techniques used. METHODS: This retrospective monocentre study included 104 patients who underwent reinforced cementoplasty and 3425 patients who underwent cementoplasty between 2012 and 2020. Operative reports and fluoroscopic images were reviewed to identify extraction attempts and their outcomes. RESULTS: Six patients (5.8%) had a malpositioned spindle, and all of them underwent spindle extraction during reinforced cementoplasty, with an 80% success rate. A total of 7 attempts were performed, using 2 different techniques. One thousand one hundred thirty patients (32%) had a cement leak in soft tissues, and 7 (0.6%) underwent cement leakage extraction during cementoplasty, with a 100% success rate. A total of 10 attempts were performed, using 3 different techniques. No major complication related to the extraction procedures occurred. CONCLUSIONS: Spindle malpositions and soft tissue cement leakages are not uncommon. We described 5 different percutaneous techniques that were safe and effective to extract spindles and paravertebral cement fragments. KEY POINTS: • Soft tissue cement leakages or spindle malpositions are a non-rare occurrence during cementoplasty, and may cause technical failure and/or chronic pain. • Most soft tissue cement fragments and malpositioned spindles can easily be extracted using simple percutaneous techniques.

Reinforced cementoplasty for pelvic tumour lesions and pelvic traumatic fractures: preliminary experience.

OBJECTIVES: Pelvic bone pathological lesions and traumatic fractures are a considerable source of pain and disability. In this study, we sought to evaluate the effectiveness of reinforced cementoplasty (RC) in painful and unstable lesions involving the pelvic bone in terms of pain relief and functional recovery. METHODS: All patients with neoplastic lesion or pelvic fracture for whom a pelvic bone RC was carried out between November 2013 and October 2017 were included in our study. All patients who failed the medical management, patients unsuitable for surgery, and patients with unstable osteolytic lesions were eligible to RC. Clinical outcome was evaluated with a 1-month and 6-month post-procedure follow-up. The primary endpoint was local pain relief measured by the visual analogue scale (VAS). RESULTS: Twenty-two patients (18 females, 4 males; mean age of 65.4 ± 13.3 years [range 38-80]) presenting with painful and unstable pelvic lesions were treated by RC during the study period. Among the 22 patients, 8 patients presented with unstable pelvic fractures (3 patients with iliac crest fracture, 3 with sacral fractures, and the remaining 2 with peri-acetabular fractures). No procedure-related complications were recorded. All patients had significant pain relief and functional improvement at 1 month. One patient (4.5%) had suffered a secondary fracture due to local tumour progression. CONCLUSIONS: Reinforced cementoplasty is an original minimally invasive technique that may help in providing pain relief and effective bone stability for neoplastic and traumatic lesions involving the pelvic bone. KEY POINTS: • Reinforced cementoplasty is feasible in both traumatic fractures and tumoural bone lesions of the pelvis. • Reinforced cementoplasty for pelvic bone lesions provides pain relief and functional recovery. • Recurrence of pelvic bone fracture was observed in 4.5% of the cases in our series.

Rescue technique for trapped bone needle in cement cast.

Avascular necrosis, or Kummel disease, is a potential complication of vertebral compression fractures. It is believed to arise as a result of a failed fracture healing process,1 2 leading to the formation of an air or fluid filled cavity within the vertebral body.3 Percutaneous vertebroplasty seems to provide both pain relief and increased spinal stability in avascular necrosis.4 In this technical video, we present the case of an osteoporotic patient with a complicated vertebroplasty, caused by trapping of the bone needle inside the intravertebral cement cast. Two methods were used sequentially, leading to retrieval of the bone needle. We identified several technical aspects, such as injection speed, quasi-filling of the vertebral cavity, and frequent rotation of the bone needle as essential for the success of the procedural. We suggest that improving these parameters may prevent intravertebral bone needle trapping in patients with avascular necrosis. neurintsurg;14/11/1158/V1F1V1Video 1.

Onyx injection by direct puncture for presurgical embolization of a C2 hypervascular metastasis from a thyroid cancer.

Surgery for spinal hypervascular lesions, such as hemangioma or metastases from thyroid or renal cancer, may be challenging because of the risk of massive blood loss.1 To overcome this limitation, presurgical embolization has gained acceptance to reduce this risk.2 However, some configurations, such as the origin of a radiculomedullary artery close to the vessels feeding the lesion or when the lesion is supplied by vessels feeding an eloquent territory, may limit the possibility of presurgical embolization, especially with microparticles.3 Direct percutaneous puncture of the spinal lesion and subsequent embolization with liquid embolic agent may be a valuable option in such challenging cases.4 We present a case of presurgical embolization of a C2 metastasis from a thyroid cancer using Onyx-18 injected by direct puncture (video 1). In this technical video, we stress the technical aspects of the direct puncture technique and the safety rules to avoid neurological complications. neurintsurg;14/1/neurintsurg-2020-017180/V1F1V1Video 1.

Reliability and accuracy of time-resolved contrast-enhanced magnetic resonance angiography in hypervascular spinal metastases prior embolization.

OBJECTIVES: Preoperative embolization of hypervascular spinal metastases (HSM) is efficient to reduce perioperative bleeding. However, intra-arterial digital subtraction angiography (IA-DSA) must confirm the hypervascular nature and rule out spinal cord arterial feeders. This study aimed to evaluate the reliability and accuracy of time-resolved contrast-enhanced magnetic resonance angiography (TR-CE-MRA) in assessing HSM prior to embolization. METHODS: All consecutive patients referred for preoperative embolization of an HSM were prospectively included. TR-CE-MRA sequences and selective IA-DSA were performed prior to embolization. Two readers independently reviewed imaging data to grade tumor vascularity (using a 3-grade and a dichotomized "yes vs no" scale) and identify the arterial supply of the spinal cord. Interobserver and intermodality agreements were estimated using kappa statistics. RESULTS: Thirty patients included between 2016 and 2019 were assessed for 55 levels. Interobserver agreement was moderate (κ = 0.52; 95% CI [0.09-0.81]) for TR-CE-MRA. Intermodality agreement between TR-CE-MRA and IA-DSA was good (κ = 0.74; 95% CI [0.37-1.00]). TR-CE-MRA had a sensitivity of 97.9%, a specificity of 71.4%, a positive predictive value of 95.9%, a negative predictive value of 83.3%, and an overall accuracy of 94.6%, for differentiating hypervascular from non-hypervascular SM. The arterial supply of the spine was assessable in 2/30 (6.7%) cases with no interobserver agreement (κ < 0). CONCLUSIONS: TR-CE-MRA can reliably differentiate hypervascular from non-hypervascular SM and thereby avoid futile IA-DSAs. However, TR-CE-MRA was not able to evaluate the vascular supply of the spinal cord at the target levels, thus limiting its scope as a pretherapeutic assessment tool. KEY POINTS: • TR-CE-MRA aids in distinguishing hypervascular from non-hypervascular spinal metastases. • TR-CE-MRA could avoid one-quarter of patients referred for HSM embolization to undergo futile conventional angiography. • TR-CE-MRA's spatial resolution is insufficient to replace IA-DSA in the pretherapeutic assessment of the spinal cord vascular anatomy.