Anatomical and pathological considerations in percutaneous vertebroplasty and kyphoplasty: a reappraisal of the vertebral venous system

Risk factors for cement leakage after percutaneous vertebral augmentation for osteoporotic vertebral compression fractures: a meta-analysis

BACKGROUND

Osteoporotic vertebral compression fractures (OVCF) may necessitate percutaneous vertebral augmentation (PVA), a procedure not without its risks. One notable complication is cement leakage (CL), which can cause significant distress in patients. Despite its clinical importance, there remains a paucity of meta-analyses investigating these complications and their management in the existing literature.

MATERIAL AND METHODS

The authors systematically reviewed PubMed, Cochrane Library, Embase, and Web of Science databases up to February 2024 to identify studies examining CL following PVA treatment in OVCF. The authors assessed the quality of eligible cohort studies using the Newcastle-Ottawa Scale (NOS), extracted data on incidence, identified risk factors for CL, and conducting meta-analysis with Revman 5.2 software. The authors calculated odd ratios (OR) and mean differences (MD) with 95% CI applying random-effects models.

RESULTS

The authors identified twelve cohort studies that matched our strict inclusion criteria. These studies included a total of 2388 patients and 3392 vertebrae. CL was identified in 1132 vertebrae. Notable risk factors for CL included compromised cortical bone integrity (OR 5.00, 95% CI 3.01-8.29, P <0.00001), presence of intravertebral vacuum clefts (OR 1.68, 95% CI 1.07-2.65, P =0.03), basivertebral foramen sign (OR 1.77, 95% CI 1.09-2.89, P =0.02), and volume of cement used (MD 0.75, 95% CI 0.41-1.10, P <0.0001).

CONCLUSION

The authors' findings underscore the significance of cortical bone integrity, intravertebral vacuum cleft, basivertebral foramen sign, and cement volume as principal determinants of CL risk in PVA for OVCF. These insights advocate for tailored surgical strategies to mitigate the risk of CL in this patient population.

Pulmonary embolism and intracardiac foreign bodies caused by bone cement leakage: a case report and literature review

Percutaneous vertebroplasty (PVP) is a surgical procedure that involves injecting polymethylmethacrylate (PMMA) bone cement into the diseased vertebrae to rapidly relieve pain and strengthen the vertebrae. We reported a 73-year-old patient who underwent percutaneous vertebroplasty (PVP) surgery for thoracolumbar vertebral compression fracture. After the surgery, the patient experienced symptoms such as chest tightness and dyspnea. Further examination revealed multiple high-density foreign bodies in the blood vessels/heart and concomitant multi-organ dysfunction. It was considered that the multi-organ embolism was caused by bone cement leakage. The patient improved after undergoing surgical treatment and anticoagulant therapy.

Analysis of Potential Risk Factors for Cement Leakage into Paraspinal Veins after Vertebroplasty for Acute Osteoporotic Vertebral Fractures Based on a 3D Reconstruction Technique: A Retrospective Matched Case-Control Study

OBJECTIVE

Pulmonary embolism, cardiac embolism, and even cerebral embolism due to paraspinal vein leakage (PVL) are increasingly reported, and their risk factors need to be adequately investigated for prevention. To this end, this study investigated the correlation of the distribution and morphological characteristics of fracture lines with the occurrence of PVL after percutaneous vertebroplasty (PVP), which has not been previously reported.

METHODS

Patients with acute single-segment thoracolumbar osteoporotic vertebral compression fractures (OVCFs) treated with PVP at our institution from January 2019 to July 2022 were selected for a matched case-control study. The case and control groups included those with and without PVL, respectively, matched at a 1:1 ratio based on general clinical characteristics. Additionally, fracture map and heatmap analysis was performed in both groups. In addition to the general clinical characteristics, the vertebral height ratio, puncture angle, delivery rate, and indexes were assessed via the three-dimensional CT reconstruction fracture line mapping technique, namely, the distribution of fracture lines, fracture line length, main fracture line shape, location of fracture line involvement, and number of fracture line branches, were compared between the two groups. The Wilcoxon rank-sum test, t tests, analysis of variance, and conditional logistic regression were used for statistical analysis.

RESULTS

Among 658 patients with OVCFs, 54 who did and 54 who did not develop PVL were included in this study. Significant differences in the puncture angle, fracture line distribution (MR-1, ML-2, MM-2, MR-2, ML-3, MM-3, LL-1, LM-1, LL-2, LM-2), fracture line involvement of the posterior wall, total fracture line length, and main fracture line length were found between the two groups (p < 0.05). Logistic univariate analysis showed significant differences in the puncture angle, fracture line distribution (MR-1, ML-2, MM-2, MR-2, ML-3, MM-3, LL-1, LL-2, LM-2, LL-3), total fracture line length, main fracture line length, and fracture line involvement of the posterior wall between the two groups (p < 0.05). Logistic multifactorial analysis showed that the fracture line distribution (UR-3, ML-3, LM-2, LR-2) and main fracture line length were independent risk factors for the development of PVL in both groups. In addition, the fracture maps and heatmaps showed a greater degree of fracture line encapsulation and more extensive involvement in the middle and lower regions of the vertebral body in the PVL group than in the control group.

CONCLUSIONS

Through a three-dimensional computed tomography reconstruction-based fracture line mapping technique, this study revealed for the first time that the distribution of fracture lines (UR-3, ML-3, LM-2, LR-2) and main fracture line length were independent risk factors for PVL after PVP in patients with acute single-segment thoracolumbar OVCFs. In addition, we hypothesized that the fracture line-vein traffic branch that may appear within 2 weeks after injury in acute OVCF patients may be one of the mechanisms influencing the above potential independent risk factors associated with PVL.

Management of Intraventricular Meningiomas

Intraventricular meningiomas (IVM) are intracranial tumors that originate from collections of arachnoid cells within the choroid plexus. The incidence of meningiomas is estimated to be about 97.5 per 100,000 individuals in the United States with IVMs constituting 0.7% to 3%. Positive outcomes have been observed with surgical treatment of intraventricular meningiomas. This review explores elements of surgical care and management of patients with IVM, highlighting nuances in surgical approaches, their indications, and considerations.

The significance of the best puncture side bone cement/vertebral volume ratio to prevent paravertebral vein leakage of bone cement during vertebroplasty: a retrospective study

OBJECTIVES

To verify the clinical significance of the best puncture-side bone cement/vertebral volume ratio (PSBCV/VV%) and bone cement leakage in paravertebral veins during vertebroplasty.

METHODS

This was a retrospective analysis of a total of 210 patients from September 2021 to December 2022, who were divided into an observation group (110 patients) and a control group (100 patients). In the observation group, patients' preoperative computed tomography (CT) data were imported into Mimics software, and the VV was calculated using the three-dimensional (3D) reconstruction function. Then, based on the best PSBCV/VV% of 13.68% determined in a previous study, the optimal PSBCV to be injected during vertebroplasty was calculated. In the control group, vertebroplasty was performed directly using the conventional method. The incidence of cement leakage into paravertebral veins was observed postoperatively in both groups.

RESULTS

There were no statistically significant differences (P > 0.05) in the evaluated indicators between the two groups pre- or postoperatively, including the anterior vertebral margin height, mid-vertebral height, injured vertebral Cobb angle, visual analogue scale (VAS) score, and Oswestry Disability Index (ODI). Intragroup comparisons showed improvements in the anterior vertebral height, mid-vertebral height, injured vertebral Cobb angle, VAS score, and ODI after surgery compared with before surgery (P < 0.05). In the observation group, there were 3 cases of cement leakage into the paravertebral veins, for a leakage rate of 2.7%. In the control group, there were 11 cases of cement leakage into the paravertebral veins, for a leakage rate of 11%. The difference in the leakage rate between the two groups was statistically significant (P = 0.016).

CONCLUSION

In vertebroplasty, preoperative VV calculations using Mimics software, combined with calculation of the PSBCV according to the best PSBCV/VV% (13.68%), can effectively prevent leakage of bone cement into paravertebral veins and further prevent serious life-threatening complications such as pulmonary embolism.

[Translated article] Relation between the volume of injected cement and the vertebral volume in the clinical outcome and in the appearance of leakage after a percutaneous vertebroplasty

OBJECTIVES

To assess the connection between the volume of injected cement and the vertebral volume measured through a volumetric analysis with a computed tomography (CT scan) in relation to the clinical result and the appearance of a leakage in patients who underwent a percutaneous vertebroplasty after an osteoporotic fracture.

MATERIALS AND METHODS

A prospective study of 27 patients (18 female-9 male) with an average age of 69 years old (50-81), and with a one-year follow-up. The study group presented 41 vertebrae with osteoporotic fractures that were treated with a percutaneous vertebroplasty with a bilateral transpedicular approach. The volume of injected cement was registered in each procedure and it was assessed together with the spinal volume measured through a volumetric analysis with CT scans. The percentage of the spinal filler was calculated. The appearance of cement leakage was proved by means of a simple radiography and a postoperative CT scan in all the cases. The leaks were classified according to the location in relation to the vertebral body (posterior, lateral, anterior and in the disc), and the significance (minor: smaller than the largest diameter of the pedicle; moderate: larger than the pedicle but smaller than the height of the vertebra; major: larger than the height of the vertebra).

RESULTS

The average vertebra volume was 26.1cm3, the average volume of the injected cement was 2.0cm3 and the percentage of the average filler was 9%. A total of 15 leaks in 41 vertebrae appeared (37%). The leaks were posterior in 2 vertebrae, vascular in 8 and into the disc in 5 vertebrae. They were deemed as minor in 12 cases, moderate in 1 and major in 2 cases. The preoperative assessment of the pain was as it follows: VAS (8) and Oswestry (67%). The cessation of pain was immediate after a year with the following postoperative results: VAS (1.7) and Oswestry (19%). The only complication was the temporary neuritis with a spontaneous resolution.

CONCLUSIONS

The injection of small amounts of cement, lower than the ones referred to by literary sources, obtains clinical results similar to the ones obtained by injecting higher amounts and it reduces the number of cement leaks and further complications.

Relationship between lumbar spinal stenosis and cauda equina movement during the Valsalva maneuver

OBJECTIVE

To confirm the relationship between lumbar spinal stenosis (LSS) and cauda equina movement during the Valsalva maneuver.

MATERIALS AND METHODS

Two radiologists at our institution independently evaluated cauda equina movement on pelvic cine MRI, which was performed for urethrorrhea after prostatectomy or pelvic prolapse in 105 patients (99 males; mean age: 69.0 [range: 50-78] years), who also underwent abdominopelvic CT within 2 years before or after the MRI. The qualitative assessment of the cine MRI involved subjective determination of the cauda equina movement type (non-movement, flutter, and inchworm-manner). The severity of LSS on abdominopelvic CT was quantified using our LSS scoring system and performed between L1/2 and L5/S1. We calculated the average LSS scores of two analysts and extracted the worst scores among all levels.

RESULTS

Cauda equina movement was observed in 15 patients (14%), inchworm-manner in 10 patients, and flutter in five patients. Participants with cauda equina movement demonstrated significantly higher LSS scores than those without movement (P < 0.001, Wilcoxon's rank-sum test). A significant difference was observed in the worst LSS scores between participants without movement and those with inchworm-manner movement (P < 0.001, Bonferroni's corrected). There were no significant differences between participants without movement and those with flutter movement (P = 0.3156) and between participants with flutter movement and those with inchworm-manner movement (P = 0.4843).

CONCLUSION

Cauda equina movement in cine MRI during the Valsalva maneuver is occasionally observed in patients with severe LSS, and may be associated with pathogenesis of redundant nerve roots.

Risk factors for pulmonary cement embolism after percutaneous vertebroplasty and radiofrequency ablation for spinal metastases

Objective

Pulmonary cement embolism is a rare but underestimated complication of vertebroplasty due to the relative lack of study and examination. This study aims to investigate the incidence of pulmonary cement embolism in patients with spinal metastasis who undergo PVP with RFA and to analyze the relative risk factors.

Methods

A total of 47 patients were retrospectively included and classified into pulmonary cement embolism (PCE) group and non-pulmonary cement embolism (NPCE) group by comparing pre- and postoperative pulmonary CT scan images. The demographic and clinical information of the patients was obtained. Demographic data in the two groups were compared using the chi-square test for qualitative data and the unpaired t test for quantitative data. Multiple logistic regression analysis was used to identify risk factors related to pulmonary cement embolism.

Results

Pulmonary cement embolism was detected in 11 patients (23.4%), and all patients were asymptomatic and followed up regularly. Risk analysis showed that multiple segments (≥3, p=0.022), thoracic vertebrae (p=0.0008), and unipedicular puncture approach (p=0.0059) were risk factors for pulmonary cement embolism. There was a high incidence of pulmonary cement embolism if bone cement leaked into the para vertebral venous plexus in the thoracic vertebra (p<0.0001). Vein leakage of cement was related to the integrity of the vertebral cortex.

Conclusion

The number of involved vertebrae, lesion location, and puncture approach are independent risk factors for pulmonary cement embolism. There was a high incidence of pulmonary cement embolism if bone cement leaked into the para vertebral venous plexus in the thoracic vertebra. Surgeons should consider these factors when formulating therapeutic strategies.

Cauda equina movement during the Valsalva maneuver in two patients with Lumbar spinal canal stenosis

Lumbar spinal canal stenosis (LSS) is a common spinal disorder among older people. Some LSS patients say that their pain worsens when they lift heavy objects. The Valsalva maneuver is the optimal breathing pattern for producing maximal force. Herein, we present two cases of LSS where the movement of the cauda equina was observed during the Valsalva maneuver.

[Cement augmentation in spinal surgery]

Bone cement has been used in spinal surgery for as long as 50 years. In contemporary spinal surgery, cement augmentation of fractured osteoporotic vertebrae in the form of vertebroplasty/kyphoplasty as well as cement augmentation of pedicle screws in instrumented procedures of any etiology are established as standard procedures. Both procedures are very effective, although the benefits of vertebroplasty/kyphoplasty procedures have been controversially discussed in the past. Overall, complications rarely occur. The most relevant complication is cement leakage, which is asymptomatic in the majority of cases but in the worst case might lead to neurological deficits, embolic events and even circulatory collapse. Prevention of cement leakage is therefore crucial. Risk factors for cement leakage and preventive measures are presented in a comprehensive review based on the available literature.

Risk factors for pulmonary cement embolism associated with percutaneous vertebral augmentation: A systematic review and meta-analysis

BACKGROUND

Pulmonary cement embolism (PCE) was a rare but fatal complication for percutaneous vertebral augmentation (PVA). Thus we did a systematic review and meta-analysis of cohort studies to investigate the risk factors for PCE after PVA.

METHODS

We systematically searched PubMed, EMBASE, Cochrane library, Google Scholar, web of science, and ClinicalTrial.gov from the establishment of the database to September 2021. All eligible studies assessing the risk factors for PCE after PVA were incorporated. Dichotomous data was calculated by risk difference (RD) from Mantel-Haenszel method (M - H method); continuous data was analyzed by mean difference (MD) from Inverse-Variance method (I-V method). All variables were taken as measure of effect by fixed effect model. Heterogeneity, sensitivity, and publication bias analyses were also performed.

RESULTS

This study totally included 13 studies. According to the Newcastle-Ottawa Scale (NOS), 7 studies were considered as low quality, with NOS< 6. The others were of relatively high quality, with NOS≥6. 144/6251 patients (2.3%) had PCE after PVA. percutaneous vertebroplasty (PVP) (RD = 0.02, 95%CI: [0.01, 0.04], Z = 3.70, P < 0.01), thoracic vertebra (RD = 0.03, 95%CI: [0.01, 0.05], Z = 3.53, P < 0.01), higher cement volume injected per level (MD = 0.23, 95%CI: [0.05, 0.42], Z = 2.44, P = 0.01), more than three vertebrae treated per session (MD = -0.05, 95%CI: [-0.08, -0.02], Z = 3.65, P < 0.01), venous cement leakage (RD = 0.07, 95%CI: [0.03, 0.11], Z = 3.79, P < 0.01) were more likely to cause PCE.

CONCLUSION

This study showed that risk factors for PCE included PVP, thoracic vertebra, higher cement volume injected per level, more than three vertebrae treated per session, venous cement leakage. As a serious complication, PCE should be paid attention and avoided.

Risk Factors for Pulmonary Cement Embolism (PCE) After Polymethylmethacrylate Augmentation: Analysis of 32 PCE Cases

OBJECTIVE

Pulmonary cement embolism (PCE) is an underestimated but potentially fatal complication after cement augmentation. Although the treatment and follow-up of PCE have been reported in the literature, the risk factors for PCE are so far less investigated. This study aims to identify the preoperative and intraoperative risk factors for the development of PCE.

METHODS

A total of 1,373 patients treated with the polymethylmethacrylate (PMMA) augmentation technique were retrospectively included. Patients with PCE were divided into vertebral augmentation group and screw augmentation group. Possible risk factors were collected as follows: age, sex, bone mineral density, body mass index, diagnosis, comorbidity, surgical procedure, type of screw, augmented level, number of augmented vertebrae, fracture severity, presence of intravertebral cleft, cement volume, marked leakage in the paravertebral venous plexus, and periods of surgery. Binary logistic regression analyses were used to analyze independent risk factors for PCE.

RESULTS

PCE was identified in 32 patients, with an incidence rate of 2.33% (32 of 1,373). For patients who had undergone vertebral augmentation, marked leakage in the paravertebral venous plexus (odds ratio [OR], 1.2; 95% confidence interval [CI], 0.1-10.3; p=0.000) and previous surgery (OR, 16.1; 95% CI, 4.2-61.0; p=0.007) were independent risk factors for PCE. Regarding patients who had undergone screw augmentation, the marked leakage in the paravertebral venous plexus (OR, 4.2; 95% CI, 0.5-37.3; p=0.004) was the main risk factor.

CONCLUSION

Marked leakage in the paravertebral venous plexus and previous surgery were significant risk factors related to PCE. Paravertebral leakage and operator experience should be concerned when performing PMMA augmentation.

Cement-associated thrombotic embolism in the inferior vena cava and bilateral iliac veins after percutaneous vertebroplasty: a case report

Percutaneous vertebroplasty (PVP) was first reported in 1987 for treating vertebral hemangiomas. PVP is also an effective treatment for osteoporotic vertebral compression fracture that mainly involves a percutaneous injection of polymethylmethacrylate. Severe complications of PVP have been reported in recent years. However, to the best of our knowledge, cement-associated thrombotic embolism in the inferior vena cava and bilateral iliac veins after PVP has rarely been reported. We experienced a patient with cement-associated thrombotic embolism in the inferior vena cava and bilateral iliac veins after PVP. Fortunately, after conservative therapy, we achieved a satisfactory result. Unfortunately, we could not explain the cause of the cement leakage and formation of the thrombotic embolism. We believe that surgeons should have a better understanding of the fracture pattern and anatomy of the vertebral venous net system. They should also perform meticulous imaging monitoring with slower pushing of the cement to minimize the risks during the PVP. This case report highlights a rare, but potentially life-threatening, complication of PVP. Surgeons need to be aware of the possibility of cement leakage and the formation of cement-associated thrombotic embolism so that they are much more vigilant when performing PVP.

The impact of intravertebral cleft on cement leakage in percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a case-control study

Background

The impact of intravertebral cleft (IVC) on cement leakage in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs) has been discussed. However, the results were conflicting, as the study population and cement leakage classification were heterogeneous. The aim of the study was to evaluate the impact of IVC on the incidence of leakage through vein, leakage through cortex as well as general leakage in PVP for OVCFs.

Methods

All patients with OVCFs who underwent PVP between January 2016 and June 2019 at our institution were retrospectively reviewed. Patients were eligible for this case-control study if they were diagnosed as single level fracture in spine. After inclusive and exclusive criteria were met, a total of 139 patients with IVC were enrolled as the study group. Non-IVC controls were matched in a 1:1 ratio in age (within 3 years), sex and fracture severity with patients in study group. Cement leakage were classified into four types [type B (through basivertebral vein), type S (through segmental vein), type-C (through a cortical defect), and type D (intradiscal leakage)], furtherly into two types [venous type (type-B or/and type S) and cortical type (type-C or/and type-D)]. A general leakage rate and a specific leakage rate per each type were compared between both groups.

Results

Each group included 139 patients. Groups were homogenous for age, sex, fracture severity, fracture location, fracture type, cement volume, puncture approach and property of cement. Compared with control group, IVC group had a significantly lower rate of type-B (20.9% vs. 31.7%, P = 0.041), type-S (24.5% vs. 52.5%, P = 0.000), and venous type leakage (37.4% vs. 67.6%, P = 0.000), a significantly higher rate of type-C (25.9% vs. 12.2%, P = 0.004), type-D (16.5% vs. 6.5%, P = 0.009), and cortical type leakage (40.3% vs. 16.5%, P = 0.000), no significant difference on the rate of general leakage (67.6% vs. 76.3%, P = 0.109).

Conclusion

IVC decreased the risk of cement leakage through vein and increased the risk of cement leakage through cortex. However, it had no significant effect on the occurrence of general leakage.

Cement pulmonary embolism after percutaneous kyphoplasty: An unusual culprit for non-thrombotic pulmonary embolism

Non-thrombotic pulmonary embolism can occur from rare but diverse etiology and is not well understood. Increasing prevalence of osteoporosis in the aging population has contributed to increased utilization of percutaneous vertebral augmentation procedures of vertebroplasty and its recent modification, kyphoplasty. Though these procedures are relatively well tolerated, there is risk of potentially fatal complication of bone cement embolization to distant vasculature. We report a case of symptomatic pulmonary cement emboli developed 2 day's post kyphoplasty and its successful treatment with novel anticoagulant for 6 months. We also summarize evidence to assist clinicians and radiologists for early identification, treatment, and prevention of cement pulmonary emboli.

Performance of Calcium Phosphate Cements in the Augmentation of Sheep Vertebrae-An Ex Vivo Study

Oil-based calcium phosphate cement (Paste-CPC) shows not only prolonged shelf life and injection times, but also improved cohesion and reproducibility during application, while retaining the advantages of fast setting, mechanical strength, and biocompatibility. In addition, poly(L-lactide-co-glycolide) (PLGA) fiber reinforcement may decrease the risk for local extrusion. Bone defects (diameter 5 mm; depth 15 mm) generated ex vivo in lumbar (L) spines of female Merino sheep (2–4 years) were augmented using: (i) water-based CPC with 10% PLGA fiber reinforcement (L3); (ii) Paste-CPC (L4); or (iii) clinically established polymethylmethacrylate (PMMA) bone cement (L5). Untouched (L1) and empty vertebrae (L2) served as controls. Cement performance was analyzed using micro-computed tomography, histology, and biomechanical testing. Extrusion was comparable for Paste-CPC(-PLGA) and PMMA, but significantly lower for CPC + PLGA. Compressive strength and Young’s modulus were similar for Paste-CPC and PMMA, but significantly higher compared to those for empty defects and/or CPC + PLGA. Expectedly, all experimental groups showed significantly or numerically lower compressive strength and Young’s modulus than those of untouched controls. Ready-to-use Paste-CPC demonstrates a performance similar to that of PMMA, but improved biomechanics compared to those of water-based CPC + PLGA, expanding the therapeutic arsenal for bone defects. O, significantly lower extrusion of CPC + PLGA fibers into adjacent lumbar spongiosa may help to reduce the risk of local extrusion in spinal surgery.

CSF-Venous Fistulas: Anatomy and Diagnostic Imaging

CSF-venous fistulas (CVFs), first described in 2014, represent an important cause of spontaneous intracranial hypotension (SIH). CVFs can be challenging to detect on conventional anatomic imaging because, unlike other types of spinal CSF leak, they do not typically result in pooling of fluid in the epidural space, and imaging signs of CVF may be subtle. Specialized myelographic techniques have been developed to help with CVF identification, but these techniques are not yet widely disseminated. This article reviews the current understanding of CVFs, emphasizing correlations between venous anatomy and imaging findings as well as potential mechanisms for pathogenesis, and describes current imaging techniques used for CVF diagnosis and localization. These techniques are broadly classified into fluoroscopy-based methods, including digital subtraction myelography and dynamic myelography, as well as cross-sectional methods, including decubitus CT myelography and MR myelography with intrathecal gadolinium. Knowledge of these various options, including their relative advantages and disadvantages, is critical in the care of patients with SIH. Investigation is ongoing, and continued advances are anticipated in understanding of CVFs as well as in optimal imaging detection.

Eponyms in Vascular Neurosurgery: Comprehensive Review of 18 Veins

This review is the first comprehensive anatomic report of all venous eponyms used in vascular neurosurgery and provides the historical context of their authors as well as the surgical relevance of every structure. A PubMed literature review identified 13 individuals for whom 18 eponymous venous structures of the brain were named. These structures are the Batson plexus, veins of Breschet, Breschet sinus, vein of Dandy, vein of Galen, prosencephalic vein of Markowski, torcular Herophili, vein of Labbé, venous plexus of Rektorzik, vein of Rolando, basal vein of Rosenthal, sylvian veins, lateral lakes of Trolard, vein of Trolard, hypoglossal plexus of Trolard, petro-occipital vein of Trolard, venous circle of Trolard, and the vein of Vesalius. Eponyms provide a valuable shorthand that encompasses anatomic nuances, variabilities, and surgical relevance. In addition, they elucidate the historical context in which these structures were described and are an academic honor to our predecessors.

Risk factor analysis of pulmonary cement embolism during percutaneous vertebroplasty or kyphoplasty for osteoporotic vertebral compression fractures

Objective

The purpose of this research is to evaluate the risk factors and incidence of pulmonary cement embolism (PCE) during percutaneous vertebroplasty (PVP) or kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCFs) based on postoperative computed tomography (CT).

Methods

A total of 2344 patients who underwent PVP or PKP due to OVCFs in our spine center were analyzed retrospectively. According to the detection of postoperative pulmonary CT, the patients were divided into two groups: pulmonary cement embolism group (PCE group) and non-pulmonary cement embolism group (NPCE group). Demographic data in both groups were compared using the χ² test for qualitative data and the unpaired t test for quantitative data. Multiple logistic regression analysis was carried out to identify risk factors that were significantly related to the PCE resulting from cement leakage.

Results

PCE was found in 34 patients (1.9% 34/1782) with pulmonary CT examination after operation. There was no statistically significant difference in the parameters such as age, gender, body mass index (BMI), and cement volume in the two groups. Patients with three or more involved vertebrae had a significantly increased risk to suffer from PCE than those with one involved vertebra (p=0.046 OR 2.412 [95% CI 1.017–5.722]). Patients who suffered thoracic fracture had a significantly increased risk to suffer from PCE than those who suffered thoracolumbar fracture (p=0.001 OR 0.241 [95% CI 0.105–0.550]). And significantly increased PCE risk also was observed in thoracic fracture compared with lumbar fracture patients (p=0.028 OR 0.094 [95% CI 0.114–0.779]). The risk of PCE within 2 weeks after fracture was significantly higher than that after 2 weeks of fracture (p=0.000 OR 0.178 [95% CI 0.074–0.429]). Patients who underwent PVP surgery had a significantly increased PCE risk than those who underwent PKP surgery (p=0.001 OR 0.187 [95% CI 0.069–0.509]).

Conclusion

The real incidence of PCE is underestimated due to the lack of routine postoperative pulmonary imaging examination. The number of involved vertebrae, fracture location, operation timing, and operation methods are independent risk factors for PCE.

Lumbar Intervertebral Spacer With Cement Augmentation of Endplates and Integrated Screws as a Fixation Device in an Osteoporotic Model: An In Vitro Kinematic and Load-to-Failure Study

BACKGROUND

Integrated lateral lumbar interbody fusion (LLIF) devices have been shown to successfully stabilize the spine and avoid complications related to posterior fixation. However, LLIF has increased subsidence risk in osteoporotic patients. Cement augmentation through cannulated pedicle screws enhances pedicle fixation and cage-endplate interface yet involves a posterior approach. Lateral application of cement with integrated LLIF fixation has been introduced and requires characterization. The present study set out to evaluate kinematic and load-to-failure properties of a novel cement augmentation technique with an integrated LLIF device, alone and with unilateral pedicle fixation, compared with bilateral pedicle screws and nonintegrated LLIF (BPS + S).

METHODS

Twelve specimens (L3-S1) underwent discectomy at L4-L5. Specimens were separated into 3 groups: (1) BPS + S; (2) polymethyl methacrylate (PMMA) augmentation, integrated LLIF, and unilateral pedicle screws (PMMA + UPS + iS); and (3) PMMA and integrated LLIF (PMMA + iSA) without posterior fixation. Flexion-extension, lateral bending, and axial rotation were applied. A compressive load was applied to L4-L5 segments until failure. An analysis was performed (P < .05).

RESULTS

Operative constructs significantly reduced motion relative to intact specimens in all motion planes (P < .05). BPS + S provided the most stability, reducing motion by 71.6%-86.4%, followed by PMMA + UPS + iS (68.1%-79.4%) and PMMA + iSA (62.9%-81.9%); no significant differences were found (P > .05). PMMA + UPS + iS provided the greatest resistance to failure (2290 N), followed by PMMA + iSA (1970 N) and BPS + S (1390 N); no significant differences were observed (P > .05).

CONCLUSIONS

Cement augmentation of vertebral endplates via the lateral approach with integrated LLIF moderately improved cage-endplate strength compared to BPS + S in an osteoporotic model; unilateral pedicle fixation further improved failure load. Reconstruction before and after application of unilateral pedicle screws and rods was biomechanically equivalent to anteroposterior reconstruction. Overall, initial results suggest that integrated LLIF with cement augmentation may be a viable alternative in the presence of osteoporosis.

Pulmonary embolism with coexistent incidental pulmonary cement embolism post vertebroplasty

A 46-year-old woman presented with sudden onset of shortness of breath and pleuritic chest pain. A CT pulmonary angiogram identified a 5 cm cement pulmonary embolus within the right main pulmonary artery with a surrounding thrombus. She had undergone an L4 vertebroplasty 3 years prior to presentation for a benign lytic lesion. Cement embolus is a known complication of cement vertebroplasty with incidence rates of approximately 0.9%. Management is usually conservative and associated morbidity and mortality rates are low. It is not known whether a previous cement embolus could provide a nidus for thrombus formation.

Risk Factors for Cement Leakage in Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures: An Analysis of 1456 Vertebrae Augmented by Low-Viscosity Bone Cement

STUDY DESIGN

Retrospective study.

OBJECTIVE

To identify risk factors for cement leakage in percutaneous vertebroplasty (PVP) using low-viscosity bone cement for osteoporotic vertebral compression fractures (OVCFs).

SUMMARY OF BACKGROUND DATA

Cement leakage is the most common complication for PVP and its risk factors have been discussed. However, data in previous series were heterogeneous. Additionally, relative smaller patient sample or more types of cement leakage classified in those studies made the results conflicting.

METHODS

A total of 1090 patients who underwent PVP with low-viscosity bone cement for OVCFs in 1456 levels between January 2016 and June 2019 were retrospectively reviewed. Parameters potentially affecting the occurrence of cement leakage were assessed using univariate and multivariate analyses. Cement leakage was assessed using postoperative computed tomography scanning, and classified into two types (cortical leakage and venous leakage) considering the mechanism.

RESULTS

The incidence of cortical and venous leakage were 20.3% (295/1456) and 56.2% (819/1456), respectively. Cortical disruption, basivertebral foramen were the strongest risk factors for cortical leakage (P = 0.000), venous leakage (P = 0.000), respectively. Greater cement volume is one risk factor for both cortical leakage and venous leakage. The intravertebral cleft, solid type of cement distribution were significant risk factors for cortical leakage, and they both were protective factors for venous leakage. For cortical leakage, older age and trauma were another two risk factors. For venous leakage, female was another one risk factor, and higher grade of fracture severity is the strongest protective factor.

CONCLUSION

Both cortical leakage and venous leakage are prevalent. Adequate known of risk factors could help balance the incidence of two type leakage in unique vertebra and reduce the incidence of leakage in general in PVP for OVCFs.Level of Evidence: 3.

The impact of incidental pulmonary cement embolism on mortality risk

The prognosis of pulmonary cement embolism found incidentally on chest radiography after vertebroplasty has been rarely investigated. This study was performed to elucidate the impact of incidentally found pulmonary cement embolism on all-cause mortality. Patients with pulmonary cement embolism diagnosed using chest radiography between 2008 and 2014 at one tertiary referral hospital were included. Their mortality risk was compared to that of randomly selected, age-, sex-, and year-matched patients without pulmonary cement embolism (ratio, 1:10) by using Kaplan-Meier estimates and covariate-adjusted Cox proportional regression analysis. The study included 11 patients with pulmonary cement embolism and 110 patients without pulmonary cement embolism. The patients showed no significant intergroup differences in baseline characteristics, except comorbid heart failure. During a mean follow-up duration of 1.7 ± 1.6 years, five patients (45.5%) with pulmonary cement embolism and 60 (50.0%) without pulmonary cement embolism died, mostly because of underlying malignancy. Although the patients with pulmonary cement embolism were not treated, they did not show a higher mortality risk than did those without pulmonary cement embolism (adjusted hazard ratio, 1.10; 95% confidence interval, 0.43-2.85). Subgroup analyses showed similar results. Incidentally found pulmonary cement embolism had no significant impact on all-cause mortality.

Revisiting the Vertebral Venous Plexus-A Comprehensive Review of the Literature

The venous drainage of the vertebral and paravertebral regions is important for a better understanding of hematogenous disease spread. Moreover, the spine surgeon must be well acquainted with this anatomy to minimize intraoperative and postoperative complications. A comprehensive review of the vertebral venous plexus (Batson plexus) was performed with a concentration on the clinical and surgical correlations of this venous network.

Spinal Epidural Abscess: A Review of Presentation, Management, and Medicolegal Implications

Spinal epidural abscess (SEA) is a rare condition associated with significant morbidity and mortality. Despite advances in diagnostic medicine, early recognition of SEAs remains elusive. The vague presentation of the disease, coupled with its numerous risk factors, the diagnostic requirement for obtaining advanced imaging, and the necessity of specialized care constitute extraordinary challenges to both diagnosis and treatment of SEA. Once diagnosed, SEAs require urgent or emergent medical and/or surgical management. As SEAs are a relatively rare pathology, high-quality data are limited and there is no consensus on their optimal management. This paper focuses on presenting the treatment modalities that have been successful in the management of SEAs and providing a critical assessment of how specific SEA characteristics may render one infection more amenable to primary surgical or medical interventions. This paper reviews the relevant history, epidemiology, clinical presentation, radiology, microbiology, and treatment of SEAs and concludes by addressing the medicolegal implications of delayed treatment of the disease.

The interest of intraoperative scanner coupled to neuronavigation in traumatic or oncologic fractures of the cervical and upper thoracic spine requiring vertebral body height restoring procedures

OBJECT

In recent years, the classical vertebroplasty has tended to be replaced by vertebral augmentation procedures. This article discusses the reliability of vertebral augmentation procedures using balloon kyphoplasty or a spine jack system, with intraoperative CT scan control coupled with the neuronavigation system as a treatment option for cervical and upper thoracic spine lesions.

METHODS

In our neurosurgical department, in the past two years, 11 patients underwent either a kyphoplasty or a vertebral augmentation by a Spine Jack via a transpedicular route, under perioperative 3D imaging, for a total of 15 cervical/upper thoracic lesions. For these patients, we evaluated the clinical symptoms before and after surgery, the intraoperative and postoperative complications as well as the radiation exposure and the duration of their hospitalisation.

RESULTS

We noted for all of the patients an improvement of the mean Karnofsky index, which improved from 50 to 80, and of the VAS that decreased from a mean of 75 to 15, as they were clearly alleviated after the operation. The radiation was lower for patients that were treated for 2 or more vertebrae, and much lower for the medical staff. The intraoperative complications rate (4 cement leakages for 15 vertebrae, 26%), was low and completely asymptomatic in all cases. The radiological follow-up examinations were satisfactory for all the patients.

CONCLUSIONS

Our results suggest that percutaneous transpedicular vertebral augmentation techniques using intraoperative CT scan are a viable treatment for secondary lesions or traumatic compression fractures of the cervical and upper thoracic spine.

Development of pulmonary endovascular metastases following vertebroplasty: case report

A 69-year-old man developed pulmonary metastases following vertebroplasties for pathological fractures of vertebrae T12-L4. The fractures developed due to spinal metastases from castrate-resistant prostate cancer. A CT scan performed 1 month prior indicated no evidence of pulmonary malignancy. However, CT scans performed 2 months after the vertebroplasties demonstrated intravascular pulmonary metastases distributed similarly to embolized polymethylmethacrylate. Vertebroplasty is a well-established procedure for symptomatic management of vertebral compression fractures. However, studies have demonstrated an increase in circulating tumor cells following vertebroplasties, theoretically increasing the risk of distant metastases. In this case, the chronicity and radiological findings suggest that the pulmonary intravascular metastases may have resulted from the vertebroplasties.

Venous Drainage of Lumbar Vertebral Bodies: Anatomic Study with Application to Kyphoplasty, Vertebroplasty, and Pedicle Screw Complications

BACKGROUND

Bone cement augmentation with polymethylmethacrylate is a reliable method for stabilizing osteoporotic compression fractures and improving fixation of pedicle screws. However, cement extrusion into the vertebral venous system can result in pulmonary cement embolism. The goal of this anatomic study was to identify the relationship between the internal/external vertebral plexus and neighboring abdominal caval system.

METHODS

Thirty-two lumbar vertebral levels were used in this study. Anterior abdominal dissection was performed to access the lumbar vertebral bodies through the peritoneal cavity, and a 16-gauge needle was placed into the center of each lumbar vertebral body at its anterior aspect. Fluoroscopy was used to confirm if the needle was correctly placed. Next, latex and/or continuous air injections were performed into each lumbar vertebral level (L1-L5). Observations confirmed if the latex or air traveled into the inferior vena cava. In addition, the spinal canal was opened to see if any latex was found to enter inside the vertebral canal in cadavers injected with the latex.

RESULTS

Latex or air was found to flow into the inferior vena cava at all the lumbar vertebral levels. The latex/air was not observed in the spinal canal in any specimen.

CONCLUSIONS

An exact knowledge of the lumbar vertebral venous anatomy is essential when procedures that could affect the vertebral venous system are involved. Its complexity and anatomic variability necessitate such an understanding to better prevent/understand possible complications associated with polymethylmethacrylate extrusion.

Current understanding of the effects of inspiratory resistance on the interactions between systemic blood pressure, cerebral perfusion, intracranial pressure, and cerebrospinal fluid dynamics

Negative intrathoracic pressure (nITP) is generated by the respiratory muscles during inspiration to overcome inspiratory resistance, thus enabling lung ventilation. Recently developed noninvasive techniques have made it possible to assess the effects of nITP in real time in several physiological aspects such as systemic blood pressure (BP), intracranial pressure (ICP), and cerebral blood flow (CBF). It has been shown that nITP from 0 to −20 cmH2O elevates BP and diminishes ICP, which facilitates brain perfusion. The effects of nITP from −20 to −40 cmH2O on BP, ICP, and CBF remain largely unrecognized, yet even nITP at −40 cmH2O may facilitate CBF by diminishing ICP. Importantly, nITP from −20 to −40 cmH2O has been documented in adults in commonly encountered obstructive sleep apnea, which justifies research in this area. Recent revelations about interactions between ICP and BP have opened up new fields of research in physiological regulation and the pathophysiology of common diseases, such as hypertension, brain injury, and respiratory disorders. A better understanding of these interactions may translate directly into new therapies in various fields of clinical medicine.

Clinical characteristics and management of cardiac and/or pulmonary cement embolus after percutaneous vertebroplasty: a single center experience

Background

Cardiac and/or pulmonary cement embolus (CPCE) caused by the leakage of bone cement after percutaneous vertebroplasty (PVP) are rare but are lethal complications in patients with vertebral compression fracture (VCF). Literature in this field is limited, and guidelines for the management of such complications are unclear. This study aimed to review our center's experience.

Methods

Medical records (clinical characteristics and management) and imaging data (X-ray findings, CT findings, and fluoroscopic findings) of 12 patients with CPCE after PVP between October 2015 and July 2018 at our hospital were collected and examined retrospectively. Their health conditions were also evaluated through a telephone follow-up survey.

Results

Twelve patients with an average age of 76.8±8.5 years were included in our study. One patient who had a cardiac cement embolus and one patient who suffered from an inferior vena cava (IVC) cement embolus were successfully treated via percutaneous retrieval. Ten asymptomatic patients with pulmonary cement embolus (PCE) were managed with conservative observation. All of the patients were alive and remained asymptomatic during the follow-up period (median time, 6.5 months; range, 1-50 months).

Conclusions

More attention should be paid to the possibility of development of CPCE. For patients with cardiac cement embolus, open heart surgery should be considered as a preferred treatment, and percutaneous procedure could be used as an alternative treatment for patients with surgical contraindication or other surgical high-risk factors. For patients with an IVC cement spike, percutaneous retrieval could be recommended. Careful observation and clinical follow-up could be recommended for patients with asymptomatic peripheral or central PCEs.

Percutaneous Vertebral Body Augmentations: The State of Art

Osteoporotic compression fractures of the vertebral body can result in pain and long-term morbidity, including spinal deformity, with increased risk of mortality resulting from associated complications. Conservative management includes opioids and other analgesics, bed rest, and a back brace. For patients with severe and disabling pain, vertebral augmentation (vertebroplasty and kyphoplasty) is often considered, with these procedures endorsed by multiple professional societies, and provides immediate structural support, and stabilizes and reinforces the weakened bone structure. The purpose of this article is to review the vertebral biomechanics, indications and contraindications, and techniques of performing successful vertebral augmentation.

Preliminary Study of Obese Patients with Chronic Obstructive Pulmonary Disease Suffering from Painful Osteoporotic Vertebral Compression Fracture Treated by Percutaneous Vertebroplasty in Improved Prone Position and Right Lateral Position

OBJECTIVE

To assess outcomes in obese patients with chronic obstructive pulmonary disease (COPD) who sustained an osteoporotic vertebral compression fracture (OVCF) treated by percutaneous vertebroplasty (PVP) in the improved prone position and right lateral position.

METHODS

Between January 2015 and May 2016, a total of 60 patients were enrolled in this randomized controlled study. Patients in group A were placed in the improved prone position for a bilateral transpedicular technique, and those in group B were placed in the right lateral position for a left transverse process-pedicle approach. Clinical and radiologic outcomes were assessed and compared between the 2 groups during the 12-month follow-up period.

RESULTS

All operations were successfully completed without any serious sequelae. The operation time, fluoroscopic time, scores for respiratory condition during the operation, intravertebral cement volume, and incidence of cement leakage were significantly greater in group A compared with group B (P < 0.01). During the follow-up period, all patients in both groups experienced significant improvement in pain relief. Satisfactory functional improvement was obtained at 3 months postoperatively.

CONCLUSIONS

Treatment of obese patients with COPD suffering from painful OVCF by PVP in both the improved prone position with a bilateral technique and the right lateral position with a unilateral technique was relatively safe and effective. However, unilateral PVP in the right lateral position was associated with a shorter operation time, limited fluoroscopic time, and minimal cement leakage.

The significance of intra-abdominal pressure in neurosurgery and neurological diseases: a narrative review and a conceptual proposal

Intra-abdominal pressure (IAP) is a physiological parameter that has gained considerable attention during the last few decades. The incidence of complications arising from increased IAP, known as intra-abdominal hypertension (IAH) or abdominal compartment syndrome in critically ill patients, is high and its impact is significant. The effects of IAP in neurological conditions and during surgical procedures are largely unexplored. IAP also appears to be relevant during neurosurgical procedures (spine and brain) in the prone position, and in selected cases, IAH may affect cerebrospinal fluid drainage after a ventriculoperitoneal shunt operation. Furthermore, raised IAP is one of the contributors to intracranial hypertension in patients with morbid obesity. In traumatic brain injury, case reports described how abdominal decompression lowers intracerebral pressure. The anatomical substrate for transmission of the IAP to the brain and venous system of the spine is the extradural neural axis compartment; the first reports of this phenomenon can be found in anatomical studies of the sixteenth century. In this review, we summarize the available knowledge on how IAP impacts the cerebrospinal venous system and the jugular venous system via two pathways, and we discuss the implications for neurosurgical procedures as well as the relevance of IAH in neurological disorders.

Spinal Epidural Arteriovenous Fistula with Perimedullary Venous Reflux: Clinical and Neuroradiologic Features of an Underestimated Vascular Disorder

BACKGROUND AND PURPOSE

The purpose of this study was to discuss the clinical and radiologic characteristics of spinal epidural arteriovenous fistulas (SEAVF) and demonstrate their specific angiomorphology in a single-center series.

MATERIALS AND METHODS

Thirteen consecutive patients were diagnosed with SEAVF at RWTH Aachen University Hospital between 2006 and 2018 and were included in this study. All patients had MR imaging and DSA before treatment; 10 of these 13 patients received contrast-enhanced MRA (CE-MRA).

RESULTS

The mean patient age was 72 ± 8 years. Paraparesis was present in 12 (92%) patients. Sphincter dysfunction and sensory symptoms were observed in 7 (54%) and 6 (46%) patients, respectively. The mean duration of symptoms was 6 ± 8 months. Congestive myelopathy on MR imaging was present in all patients. Prominent arterialized perimedullary veins were demonstrated in only 3 cases. CE-MRA revealed arterialized perimedullary veins and an arterialized epidural pouch in 9/10 (90%) patients, mostly located ventrolaterally. DSA demonstrated a multisegmental extension of the arterialized ventrolateral epidural pouch in 6 (46%) cases. An intradural radicular drainage vein was localized distant from the original fistula point in 3 (23%) patients.

CONCLUSIONS

Congestive myelopathy with an acute/subacute clinical course was the dominant finding in spinal epidural arteriovenous fistulas. CE-MRA is a powerful diagnostic tool for identifying arterialized perimedullary veins as well as an arterialized epidural pouch. While arterialized perimedullary veins frequently present with only mild enlargement and elongation in spinal epidural arteriovenous fistulas, the arterialized epidural pouch is frequently located ventrolaterally and may extend over several vertebral levels. DSA remains the criterion standard to precisely visualize a spinal epidural arteriovenous fistula and its intradural radicular drainage vein, which may be located distant from the fistulous point.

Characterization of polyurethane-based synthetic vertebrae for spinal cement augmentation training

Vertebral augmentation techniques are used to stabilize impacted vertebrae. To minimize intraoperative risks, a solid education of surgeons is desirable. Thus, to improve education of surgeons as well as patient safety, the development of a high-fidelity simulator for the surgical training of cement augmentation techniques was initiated. The integrated synthetic vertebrae should be able to provide realistic haptics during all procedural steps. Synthetic vertebrae were developed, tested and validated with reference to human vertebrae. As a further reference, commercially available vertebrae surrogates for orthopedic testing were investigated. To validate the new synthetic vertebrae, characteristic mechanical parameters for tool insertion, balloon dilation pressure and volume were analyzed. Fluoroscopy images were taken to evaluate the bone cement distribution. Based on the measurement results, one type of synthetic vertebrae was able to reflect the characteristic parameters in comparison to human vertebrae. The different tool insertion forces (19.7 ± 4.1, 13.1 ± 0.9 N, 1.5 ± 0.2 N) of the human reference were reflected by one bone surrogate (11.9 ± 9.8, 24.3 ± 3.9 N, 2.4 ± 1.0 N, respectively). The balloon dilation pressure (13.0 ± 2.4 bar), volume (2.3 ± 1.5 ml) of the synthetic vertebrae were in good accordance with the human reference (10.7 ± 3.4 bar, 3.1 ± 1.1 ml). Cement application forces were also in good accordance whereas the cement distribution couldn't be reproduced accurately. Synthetic vertebrae were developed that delivered authentic haptics during transpedicular instrument insertion, balloon tamp dilation and bone cement application. The validated vertebra model will be used within a hybrid simulator for minimally invasive spine surgery to educate and train surgeons.

Pulmonary cement embolism following cement-augmented fenestrated pedicle screw fixation in adult spinal deformity patients with severe osteoporosis (analysis of 2978 fenestrated screws)

INTRODUCTION

There is very limited information about pulmonary cement embolism (PCE) following cement-augmented fenestrated pedicle screw (CAFPS) fixation in the literature. The aim of this study to report the incidence of PCE following CAFPS fixation in adult deformity patients with severe osteoporosis and to identify risk factors such as; the number of levels, number of screws, and the cement volume used.

METHODS

281 patients (204F, 77M) in whom CAFPS fixation was used during deformity surgery were included. All patients' routine postop 2 day chest X-rays and any available CT scans were reviewed by two radiologists. In patients with PCE, preop, early postop, and latest echocardiography studies were compared in terms of changes in pulmonary artery pressure (PAP) and right ventricular dilatation. Estimated cement volume used was calculated as: 2 cc (1 cc + 1 cc) per thoracic and 3 cc (1.5 cc + 1.5 cc) per lumbar levels, which are our routine protocol. Statistical analysis for risk factors was assessed with point biserial correlation test.

RESULTS

Average age is 70.5 (51-89) and average follow-up is 3.2 years (2-5). A total of 2978 CAFPS were instrumented with a mean of 10.5 levels (2-16) in 281 patients. PCE was diagnosed radiologically in 46 patients (16.3%). Among these 46 patients, PCE was clinically symptomatic in only 4 patients. Overall incidence of symptomatic PCE was 1.4% (4 of 281). Symptomatic PCE was statistically significant: when CAFPS fixation was performed > 7 levels; > 14 screws were used, and > 20-25 cc cement was used for augmentation (r = 0.378). In PCE group, mean preop PAP values of 27.40 (20-37) mm/Hg increased to 32.34 (20-50) mm/Hg in early postop and decreased to 28.29 (18-49) mm/Hg at final follow-up. In symptomatic PCE patients, mean preop PAP values of 30.75 (28-36) mm/Hg increased to 45.74 (40-50) mm/Hg in early postop and decreased to 38.75 (37-40) mm/Hg at final follow-up.

CONCLUSION

This study showed an overall 16.3% radiological PCE and 1.4% symptomatic PCE incidence when CAFPS were used due to severe osteoporosis. The symptomatic PCE risk was significant when CAFPS were > 7 levels; > 14 fenestrated screws; and > 20-25 cc cement volume is used and this may cause PAP increase and right ventricular dilatation.

Presentation and management of symptomatic central bone cement embolization

BACKGROUND CONTEXT

With more cement augmentation procedures done, the occurrence of serious complications is also expected to rise. Symptomatic central cement embolization is a rare but very serious complication. Moreover, the pathophysiology and treatment of intrathoracic cement embolism remain controversial.

PURPOSE

In this case series, we are trying to identify various presentations and suggest our emergent management scheme for symptomatic central cement embolization.

PATIENT SAMPLE

Retrospective case series of nine patients with symptomatic central cement embolism identified after vertebroplasty with 24 months of follow-up. Level IV.

OUTCOME MEASURES

The degree of dyspnea measured by the New York Heart Association (NYHA) score and/or death related to cement embolism induced cardio/respiratory failure at the final follow-up at 24 months.

METHODS

The nine patients, eight females, and one male had a mean age of 70.25 years (range 65-78 years) and were operated between January 2004 and December 2014. They had percutaneous vertebroplasty for osteoporotic non-traumatic and malignant vertebral collapse of dorsal and lumbar vertebrae. Post-vertebroplasty dyspnea and stitching chest pain were striking in the nine patients. After exclusion of cardiac ischemia and medical pulmonary causes for dyspnea, we identified radiopaque lesions on the chest X-ray. Further echocardiography and high-resolution chest CT were performed for optimal localization. Emergent heart surgery was performed in two patients: interventional therapy was conducted in one patient, while the remaining six patients were conservatively treated by anticoagulation. The management decision was taken in the setting of an interdisciplinary meeting depending on localization, fragmentation, and clinical status.

RESULTS

All patients of this series showed gradual improvement and an uneventful hospital stay. During our 24-month follow-up phase, eight patients showed no subsequent cardiological and/or respiratory symptoms (NYHA I). However, one mortality due to advanced malignancy occurred. Preoperative anemia was the only common intersecting preoperative parameter among these nine patients.

CONCLUSIONS

After cement augmentation, close clinical monitoring is mandatory. A chest CT is pivotal in determining the interdisciplinary management approach in view of the availability of necessary expertise, facilities and the location of the cement emboli whether accessible by cardiac or vascular surgical means. The clinical presentation and its timing may vary and the patient may be seen subsequently by other health care providers obligating a wide-spread awareness for this serious entity among health care providers for this age group as spine surgeons, family and emergency room doctors, and institutional or home-care nurses. Most symptomatic central cement emboli may be treated conservatively.