Injection Of Methylmethacrylate Research Articles

Acute hemodynamic instability during alcohol ablation of symptomatic vertebral hemangioma: A prospective study

Symptomatic vertebral hemangiomas (SVH) are difficult to treat and many therapeutic options, including surgery, radiotherapy, arterial embolization, and injection of methyl-methacrylate into hemagiomatous vertebrae have been reported. Alcohol ablation of vertebral hemangiomas is an effective management option; however, a literature search did not reveal any reports of anesthetic complications or hemodynamic instability during and report a series of four males and seven females and report hemodynamic variations observed at the time of injection of absolute ethanol under general anesthetic, for the treatment of SVH. The median age of the patients was 20 years (range, 10–36 years), and median weight was 45 kg (range, 30–70 kg). All patients developed transient hypotension and bradycardia at the time of alcohol injection (8–10 mL of absolute alcohol). No patient required intervention with vagolytics or vasopressors. It is likely that the administration of alcohol in small aliquots prevented any major consequences. Moreover, patients under general anesthesia are at lower risk than those receiving monitored sedation, with better control over hemodynamics.

Quality Improvement Guidelines for Bone Tumour Management

Curative treatment The therapeutic goal of curative treatment is to completely and definitively ablate the tumour. Palliative treatment The therapeutic goal of palliative treatment is not to completely ablate the tumour but to achieve pain palliation. Consolidation Techniques Cementoplasty Percutaneous injection of methylmethacrylate provides bone strengthening and pain relief [5, 6]. Cementoplasty is a symptomatic and not a curative treatment [7, 8]. Ablation Techniques Chemical ablation Injection of ethanol is used to ablate osteolytic bone tumours as well as achieve pain management (neurolysis) [9]. Thermal ablation procedures consist of the following: 1. Laser photocoagulation Thermoablation is produced with near-infrared wavelength lasers (neodymium yttrium aluminum garnet [Nd:YAG] diode laser 800–1000 nm). 2. Radiofrequency ablation Thermoablation is produced by altering the electric current at the tip of the electrode, thus causing local ionic agitation and subsequent frictional heat. 3. Cryoablation The application of extreme cold aims to destroy cells by causing both direct cellular and vascular injury [10, 11]. Radiofrequency ionisation (decompression ablation technique) consists of the following: 1. Low-temperature bipolar technique: This produces a plasma field at the tip of the electrode that breaks the intermolecular bonds, thus creating a cavity inside the tissue, which leads in turn to decompression.

The Ingegerd and Viking Olov Björk Scholarship for Thoracic and Cardiovascular Research

Ischaemic preconditioning protects the myocardium from ischaemic injury and may also protect the vascular endothelium from the deleterious effects of ischaemia and reperfusion. We examined the possibility that ischaemic preconditioning might preserve the integrity of the coronary microcirculation following ischaemia and reperfusion. Isolated rat hearts were perfused in Langendorff mode for 30 minutes and then subjected to 30 minutes of global ischaemia with or without ischaemic preconditioning (threexthree minute cycles). Some hearts underwent an additional 60 minutes of reperfusion. At the end of each protocol, microvascular corrosion casts were made by methylmethacrylate injection. Median left ventricular capillary density [interquartile range] after ischaemia was slightly but not significantly better with preconditioning at 6.8 [4.0-14.7]x10(-2) mm3.mg(-1) vs. 5.2 [2.6-7.1]x10(-2) mm3.mg(-1) (p=0.13). After 60 min of reperfusion, capillary density in preconditioned left ventricles was 20.7 [10.7-22.8]x10(-2) mm3.mg(-1) vs. 16.0 [10.2-23.0]x10(-2) mm3.mg(-1) for untreated ventricles (p=0.47). Coronary blood flow and heart rate were unchanged from before ischaemia. Ischaemia for 30 minutes induced global left ventricular capillary loss which was unmodified by preconditioning. We did not demonstrate vascular preconditioning using this model.

Microvascular preconditioning is not detectable by corrosion casting in the isolated perfused rat heart after 30 minutes of ischaemia

Objective. Ischaemic preconditioning protects the myocardium from ischaemic injury and may also protect the vascular endothelium from the deleterious effects of ischaemia and reperfusion. We examined the possibility that ischaemic preconditioning might preserve the integrity of the coronary microcirculation following ischaemia and reperfusion. Methods. Isolated rat hearts were perfused in Langendorff mode for 30 minutes and then subjected to 30 minutes of global ischaemia with or without ischaemic preconditioning (three×three minute cycles). Some hearts underwent an additional 60 minutes of reperfusion. At the end of each protocol, microvascular corrosion casts were made by methylmethacrylate injection. Results. Median left ventricular capillary density [interquartile range] after ischaemia was slightly but not significantly better with preconditioning at 6.8 [4.0–14.7]×10−2 mm3.mg−1vs. 5.2 [2.6–7.1]×10−2 mm3.mg−1 (p =0.13). After 60 min of reperfusion, capillary density in preconditioned left ventricles was 20.7 [10.7–22.8]×10−2 mm3.mg−1vs. 16.0 [10.2–23.0]×10−2 mm3.mg−1 for untreated ventricles (p =0.47). Coronary blood flow and heart rate were unchanged from before ischaemia. Conclusions. Ischaemia for 30 minutes induced global left ventricular capillary loss which was unmodified by preconditioning. We did not demonstrate vascular preconditioning using this model.

Symptomatic vertebral hemangiomas- results of treatment with radiotherapy

Abstract Objectives : Vertebral hemangiomas are benign vascular lesions occurring in spine. Though vertebral hemangiomas are frequently seen, they are rarely symptomatic. Pain is the commonest symptom. There is no agreement on single treatment modality for symptomatic lesions. Surgery, intralesional injection of absolute alcohol, methyl methacrylate injection are few methods used to treat them. Radiotherapy has been shown effective in many studies in terms of pain relief and at times in cord compression too. Results of radiotherapy in symptomatic vertebral hemangiomas treated in our centre are analyzed. Materials and methods: Six patients with symptomatic vertebral hemangiomas were treated with external radiotherapy to a dose of 36-40 Gy. Four patients had only pain as their symptom. Two patients had additional neurological deficits with paraperesis at presentation. Result in terms of pain relief was assessed at the end of RT and during follow up. Median follow up was four and half months. Results : Out of six patients, pain relief was seen in four patients who had only pain as their symptom. There was neither pain relief nor improvement in neurological deficits in remaining two patients. Conclusion : Radiotherapy is an effective and simple modality of treatment for symptomatic vertebral hemangiomas where pain is the main symptom without neurological deficits. It is non invasive and safe.

Percutaneous cementoplasty of acetabular bony metastasis

The development of malignant lesions in the acetabulum can lead to painful and disabling bone destruction. Lytic metastases of the acetabulum are frequent, causing pathologic fractures, pain and disability. The literature is sparse in relation to the exact indications and technique for this procedure. Percutaneous injection of methylmethacrylate or ethanol may provide marked pain relief or bone strengthening in patients, with malignant acetabular destruction, who are unable to tolerate surgery. Injection of methylmethacrylate is usually indicated when the weight-bearing part of the acetabulum is involved. The goals of treatment are pain relief and mechanical strengthening of the acetabulum. Radiography and computed tomography must be performed prior to therapeutic percutaneous injection to assess the location and extent of the lytic process, the presence of cortical destruction or fracture, and the presence of soft-tissue involvement. We report a case of a 39-year-old woman with a secondary acetabular lesion, which was treated successfully with percutaneous acetabular cementoplasty. We describe a novel technique used to inject cement into the lesion, allowing for greater cement volume and pressurisation within the lesion.

Therapeutic percutaneous injections in the treatment of malignant acetabular osteolyses.

Percutaneous injection of methylmethacrylate or ethanol may provide marked pain relief or bone strengthening in patients with malignant acetabular osteolyses who are unable to tolerate surgery. Injection of methylmethacrylate is usually indicated when osteolysis involves the weight-bearing part of the acetabulum (ie, the acetabular roof); in all other cases, ethanol injection is preferred. Ethanol and methylmethacrylate injections may be performed together if both weight-bearing and nonweight-bearing parts of the acetabulum are involved or extensive soft-tissue involvement is present. Moreover, these injections may be performed prior to radiation therapy, which complements their action due to similar but delayed effects on pain, or after radiation therapy that failed to relieve pain or in cases of local recurrence. Radiography and computed tomography must be performed prior to therapeutic percutaneous injection to assess the location and extent of the lytic process, the presence of cortical destruction or fracture, and the presence of soft-tissue involvement. Fever and transitory worsening in pain may occur secondary to inflammatory reaction in the hours following injection; however, these side effects usually resolve spontaneously within 1-3 days. The decision to perform therapeutic percutaneous injections should be made by a multidisciplinary team because the choice between this option and alternative methods of treatment depends on several factors including the location of the lesion, the local and general extent of the disease, the pain and functional disability experienced by the patient, and the patient's state of health and life expectancy.

Percutaneous Treatment of Benign Vertebral Compression Fractures with CT-guided Transpedicular Methylmethacrylate Injection

Percutaneous Treatment of Benign Vertebral Compression Fractures with CT-guided Transpedicular Methylmethacrylate Injection

Percutaneous vertebroplasty for osteolytic metastases and myeloma: effects of the percentage of lesion filling and the leakage of methyl methacrylate at clinical follow-up.

To determine whether the percentage of vertebral lesion filling and the leakage of methyl methacrylate have any clinical significance at follow-up. Forty percutaneous vertebroplasties were performed for metastases (30 cases) and myeloma (10 cases) in 37 patients. A computed tomographic scan was obtained 1-8 hours after methyl methacrylate injection and was used to assess the percentage of lesion filling by methyl methacrylate and the leakage of methyl methacrylate into the epidural tissues, neural foramina, intervertebral disks, venous plexus, and paravertebral tissue. The results were correlated with those obtained at clinical follow-up. Partial or complete pain relief was sustained in 36 of 37 patients. Pain relief was not proportional to the percentage of lesion filling. Clinical improvement was maintained in most patients. The 15 epidural leaks, eight intradiskal leaks, and two venous leaks of methyl methacrylate had no clinical importance. Two of eight foraminal leaks produced nerve root compression that required decompressive surgery. One of 21 paravertebral leaks produced transitory femoral neuropathy. Pain relief can occur despite insufficient lesion filling. In most patients, intradiskal and paravertebral leaks of cement had no clinical importance.

A Modified Technique for the Fixation of Pathologic Fractures in the Lower Femur

Intramedullary nail fixation augmented by the pressure injection of methylmethacrylate was investigated by use of bovine femora. In this technique, the nail is first placed in its final desired position; cement is then injected with a conical-tipped syringe through a distal drill hole into the medullary canal around the nail. This method was compared with the conventional technique of first placing the cement into the medullary canal and then driving the nail into position. Calf femora were used to compare the cement pressures generated, the shear resistance at the bone/cement interface, and the contour of the endosteal cement surface produced by the two cementing techniques. Significantly higher bone/cement interface pressures were generated by the injection of cement. Shear resistance at the bone/cement interface, investigated by push-out tests, revealed no significant difference between the two techniques. Dissolution of the specimens in nitric acid produced a methylmethacrylate cast of the endosteal surface, thus revealing the pattern of cement penetration into endosteal bone. The cement surfaces made by the injection of cement revealed characteristics of superior fixation and penetration compared to those made by the conventional method. The injection of cement for pathologic long-bone fractures is safer than the conventional method, is less susceptible to intraoperative complications, and offers satisfactory fixation.

Closed Intramedullary Rodding of Pathologic Fractures with Supplemental Cement

Internal fixation, supplemented with methylmethacrylate to fill bone defects, is the standard treatment for pathologic fractures. Unfortunately, internal fixation procedures often entail substantial blood loss and a not inconsequential risk of infection, problems with which the debilitated patient is poorly able to cope. Techniques such as closed intramedullary rodding entail less operative morbidity but may not produce complete stabilization and immediate pain relief. This report describes a technique that minimizes operative morbidity and produces immediate fracture stabilization by use of closed intramedullary rodding and injection of methylmethacrylate through a cortical drill hole in the long bone.

Changes in vascular morphology associated with the no-reflow phenomenon in ischaemic myocardium

To investigate the pathogenesis of the reperfusion defect which develops in ischaemic myocardium, intravascular casts were prepared by injection of methyl methacrylate into the coronary arteries of isolated heparinised rat hearts. Using a scanning electron microscope, the vascular morphology following 60 min of global ischaemia at 37 degrees C was compared to that of non-ischaemic control hearts injected immediately after stopping perfusion with oxygenated Krebs-Henseleit buffer. Complete casts were obtained from control hearts and from all parts of ischaemic hearts except the subendocardial half of the left ventricular wall of ischaemic hearts where the blood vessels were not filled. At the border between the perfused subepicardial and unperfused left subendocardial regions, the resin which filled the radial penetrating arteries and their branches projected from the filled capillary plexus to an extent proportional to their diameter. Intravascular events such as erythrocyte plugging and thrombosis were excluded as causative factors by the use of a cell-free perfusate. Also, there was no morphological evidence that endothelial cell swelling or constriction of any particular population of vessels was involved. The observed pattern of vascular occlusion suggests that, during global ischaemia, blood vessels in the endocardial half of the left ventricular myocardium lose their ability to be reperfused because of extravascular compression.

Morphology and vascular anatomy of the gills of a primitive air-breathing fish, the bowfin (Amia calva).

The morphology of the gills of a primitive air breather (Amia calva) was examined by light microscopy of semithin sections of gill filaments, and gill perfusion pathways were identified by scanning-electron microscopic analysis of corrosion replicas prepared by intravascular injection of methyl methacrylate. The arrangement of gill filaments and respiratory lamellae is similar to that ot teleosts with the exception of an interfilamental support bar that is fused to the outer margins of lamellae on adjacent filaments. The prebranchial vasculature is also similar to that of teleosts, whereas the postbranchial circulation of arches III and IV is modified to permit selective perfusion of the air bladder. Gill filaments contain three distinct vascular systems: (1) the respiratory circulation which receives the entire cardiac output and perfuses the secondary lamellae; (2) a nutrient system that arises from the postlammelar circulation and perfuses filamental tissues; (3) a network of unknown function consisting of subepithelial sinusoids surrounding afferent and efferent margins of the filament and traversing the filament beneath the interlamellar epithelium. Prelamellar arteriovenous anastomoses (AVAs) are rare, postlammelar AVAs are common especially at the base of the filament where they form a dense network of small tortuous vessels before coalescing into a large filamental nutrient artery. Unlike in most teleosts, the outer vascular margins of the lamellae are embedded in the interfilamental support bar and become the sole vasculature of this tissue. Arterial-arterial lamellar bypass vessels were not observed. Previously observed decreases in oxygen transfer across the gills during air breathing can be explained only by redistribution of blood flow between or within the respiratory lamellae.

An Experimental Model for Extracorporeal Renal Surgery

An experimental model for the evaluation of surgical techniques and preservation in extracorporeal surgery is described: staghorn calculi were induced in 15 dogs by the injection of methylmethacrylate into the renal pelvis. Removal of the calculi was carried out 3-4 weeks later on a workbench, using microsurgical techniques and ex situ radiographies. 15 min of warm ischaemic and 6 h of ambiothermic preservation were well tolerated as could be demonstrated by determination of the serum creatinine following autotransplantation and immediate contralateral nephrectomy.