[A woman with a swollen upper arm]

A 74-year-old female patient presented at the emergency department with a swollen upper arm after a CT-scan. X-ray showed extensive extravasation with iodinated contrast media. Extravasations of high volume or high osmolality can lead to severe tissue damage. Early recognition and treatment is important, since it could prevent further injury.

Nanoparticles promote in vivo breast cancer cell intravasation and extravasation by inducing endothelial leakiness

While most cancer nanomedicine is designed to eliminate cancer, the nanomaterial per se can lead to the formation of micrometre-sized gaps in the blood vessel endothelial walls. Nanomaterials-induced endothelial leakiness (NanoEL) might favour intravasation of surviving cancer cells into the surrounding vasculature and subsequently extravasation, accelerating metastasis. Here, we show that nanoparticles induce endothelial leakiness through disruption of the VE-cadherin-VE-cadherin homophilic interactions at the adherens junction. We show that intravenously injected titanium dioxide, silica and gold nanoparticles significantly accelerate both intravasation and extravasation of breast cancer cells in animal models, increasing the extent of existing metastasis and promoting the appearance of new metastatic sites. Our results add to the understanding of the behaviour of nanoparticles in complex biological systems. The potential for NanoEL needs to be taken into consideration when designing future nanomedicines, especially nanomedicine to treat cancer.

A modification and validation of quantitative morphometry classification system for osteoporotic vertebral compressive fractures in mainland Chinese

This study described a modified quantitative morphometry (mQM) system adapted to specific reference values for Mainland Chinese population. The mQM system is validated using the Genant Semiquantative system and is sensitive for detecting vertebral height changes and predicting cement leakage after percutaneous kyphoplasty (PKP) in patients with osteoporotic vertebral compressive fracture (OVCF).

INTRODUCTION

OVCF is a manifestation of osteoporosis. To improve clinical management of osteoporosis, the quantitative morphometry (QM) system has been widely used for the early diagnosis and precise classification of OVCF in developed countries. Here, we present an mQM system and validated its use in detecting OVCF in Mainland Chinese.

METHODS

Using our mQM system, the pre- and post-operative values of vertebral heights were measured and evaluated in 309 Mainland Chinese who received percutaneous kyphoplasty (PKP) as OVCF treatment. Measurements and classification of fractures from the mQM system were validated by comparing to values obtained by the Genant semiquantative (SQ) method. Moreover, we evaluated the sensitivity of the mQM system by its ability to detect restoration of vertebral heights and predict cement leakage after PKP.

RESULTS

The five classification of fractures, No deformity (ND), anterior wedge (AW), posterior wedge (PW), biconcavity (BC), and compression (CP), evaluated by the mQM method shared similar distribution characteristics compared to those obtained by the SQ method. In addition, mQM evaluation showed that the vertebra height of all fracture types showed significant restoration after PKP. The incidence of cement leakage was most common in CP (37.5%), followed by AW (31.6%), BC (26.5%), ND (23.7%), and PW (0.0%).

CONCLUSIONS

Our mQM system is suitable for classification of fractures, detection of vertebral height restoration, and correlation of cement leakage after PKP in Mainland Chinese population.

Efficacy of Dehydrated Human Amniotic Membrane Allograft for the Treatment of Severe Extravasation Injuries in Preterm Neonates

INTRODUCTION

A peripheral intravenous (PIV) catheter is placed in 60% to 70% of neonatal intensive care unit (NICU) infants. Extravasation injuries occur in 18% to 33%, with 70% in neonates < 27 weeks of gestational age. Despite such frequent use of PIV therapy, evidence on best practice, injury prevention, management, and treatment of extravasations is lacking.

OBJECTIVE

This case series of 4 neonatal patients describes the experience and efficacy of using a dehydrated human amniotic membrane allograft (dHAMA) in the treatment of severe extravasation injuries.

MATERIALS AND METHODS

The 4 preterm, critically ill neonates, all with stage 4 extravasations, were treated with 1 to 2 applications of the dHAMA to facilitate the repair process. Prior to treatments, standard of care included either enzymatic (collagenase ointment) or autolytic debridement (active Leptospermum honey) followed by mechanical debridement prior to allograft placement.

RESULTS

The 4 full-thickness wounds exhibited recalcitrant healing. The dHAMA invigorated the wounds after standard management failed to induce repair. Application was easy and follow-up care was minimal. All wounds healed without contractures and with minimal soft scars and normal pigmentation at the 1- to 2-month follow-up visits.

CONCLUSIONS

The dHAMA proved to be an effective, safe, and easy-to-apply treatment in this case series, leading to regeneration and healing of deep neonatal wounds associated with extravasations.

Intravascular Survival and Extravasation of Tumor Cells

Most metastasizing tumor cells reach distant sites by entering the circulatory system. Within the bloodstream, they are exposed to severe stress due to loss of adhesion to extracellular matrix, hemodynamic shear forces, and attacks of the immune system, and only a few cells manage to extravasate and to form metastases. We review the current understanding of the cellular and molecular mechanisms that allow tumor cells to survive in the intravascular environment and that mediate and promote tumor cell extravasation. As these processes are critical for the metastatic spread of tumor cells, we discuss implications for potential therapeutic approaches and future research.

Peripheral arteriovenous fistula as vascular access for long-term chemotherapy

INTRODUCTION

To provide long-term vascular access in clinical oncology peripheral forearm veins (up to 95% of patients in Ukraine), central venous access and "complete implanted vascular systems" are used most often. Many oncology patients have contraindications to catheterization of superior vena cava. Besides, exploitation of central veins is associated with potential technical and infectious complications. The aim - to study short-term and long-term results of arteriovenous fistula exploitation as vascular access for continuous anticancer therapy.

MATERIALS AND METHODS

Peripheral venous bed status in 41 oncology patients taking long-term chemotherapy treatment is analyzed in the article. Doppler sonography, morphologic and immune histochemical analyses were used in the study.

RESULTS

Doppler sonography found qualitative and quantitative changes in forearm veins at different time periods after initiation of chemotherapy in the majority of patients. The major morphologic manifestations of venous wall damage were chemical phlebitis, local or extended hardening of venous wall, venous thrombosis and extravasations with necrosis and subsequent paravasal tissue sclerosis. Alternative vascular access created in 12 patients completely met the adequacy criteria (safety, multiple use, longevity, realization of the designed therapy program). The conclusion was made about inapplicability of forearm veins for long-term administration of cytostatic agents. If it is impossible to use central veins, arteriovenous fistula can become an alternative vascular access.

Angiopellosis as an Alternative Mechanism of Cell Extravasation

Stem cells possess the ability to home in and travel to damaged tissue when injected intravenously. For the cells to exert their therapeutic effect, they must cross the blood vessel wall and enter the surrounding tissues. The mechanism of extravasation injected stem cells employ for exit has yet to be characterized. Using intravital microscopy and a transgenic zebrafish line Tg(fli1a:egpf) with GFP-expressing vasculature, we documented the detailed extravasation processes in vivo for injected stem cells in comparison to white blood cells (WBCs). While WBCs left the blood vessels by the standard diapedesis process, injected cardiac and mesenchymal stem cells underwent a distinct method of extravasation that was markedly different from diapedesis. Here, the vascular wall undergoes an extensive remodeling to allow the cell to exit the lumen, while the injected cell remains distinctively passive in activity. We termed this process Angio-pello-sis, which represents an alternative mechanism of cell extravasation to the prevailing theory of diapedesis. Stem Cells 2017;35:170-180 Video Highlight: https://youtu.be/i5EI-ZvhBps.

Numerical simulation of a single cell passing through a narrow slit

The narrow slit between endothelial cells that line the microvessel wall is the principal pathway for tumor cell extravasation to the surrounding tissue. To understand this crucial step for tumor hematogenous metastasis, we used dissipative particle dynamics method to investigate an individual cell passing through a narrow slit numerically. The cell membrane was simulated by a spring-based network model which can separate the internal cytoplasm and surrounding fluid. The effects of the cell elasticity, cell shape, nucleus and slit size on the cell transmigration through the slit were investigated. Under a fixed driving force, the cell with higher elasticity can be elongated more and pass faster through the slit. When the slit width decreases to 2/3 of the cell diameter, the spherical cell becomes jammed despite reducing its elasticity modulus by 10 times. However, transforming the cell from a spherical to ellipsoidal shape and increasing the cell surface area by merely 9.3 % can enable the cell to pass through the narrow slit. Therefore, the cell shape and surface area increase play a more important role than the cell elasticity in cell passing through the narrow slit. In addition, the simulation results indicate that the cell migration velocity decreases during entrance but increases during exit of the slit, which is qualitatively in agreement with the experimental observation.

Macromolecule extravasation-xenograft size matters: a systematic study using probe-based confocal laser endomicroscopy (pCLE)

PURPOSE

Profound changes of the vasculature in tumors critically impact drug delivery and therapy response. We aimed at developing a procedure to monitor morphological and functional parameters of the vasculature in subcutaneous xenograft models commonly applied for therapy testing by using probe-based confocal laser endomicroscopy.

PROCEDURES

By monitoring various normal and diseased tissues, we established an experimental and analytical set-up to systematically analyze tracer extravasation from the microvasculature. Application of the approach in two xenograft models (HCT-116 and SW620) was realized consecutively throughout tumor growth.

RESULTS

The incidence of dilated vessels increased with xenograft size in both models while macromolecule extravasation and tracer accumulation in the tumor tissue, respectively, was significantly reduced throughout growth. The development of dilated/ultradilated vessels correlated with tracer extravasation only in the HCT-116 but not the SW620 model. The underlying mechanisms are still ambiguous and discussed.

CONCLUSIONS

Our findings clearly indicate that both xenograft type and size matter for drug delivery and therapy testing.

Nitrite induces the extravasation of iron oxide nanoparticles in hypoxic tumor tissue

Nitrite undergoes reconversion to nitric oxide under conditions characteristic of the tumor microenvironment, such as hypoxia and low pH. This selective conversion of nitrite into nitric oxide in tumor tissue has led to the possibility of using nitrite to enhance drug delivery and the radiation response. In this work, we propose to serially characterize the vascular response of brain tumor-bearing rats to nitrite using contrast-enhanced R2 * mapping. Imaging is performed using a multi-echo gradient echo sequence at baseline, post iron oxide nanoparticle injection and post-nitrite injection, whilst the animal is breathing air. The results indicate that nitrite sufficiently increases the vascular permeability in C6 gliomas, such that the iron oxide nanoparticles accumulate within the tumor tissue. When animals breathed 100% oxygen, the contrast agent remained within the vasculature, indicating that the conversion of nitrite to nitric oxide occurs in the presence of hypoxia within the tumor. The hypoxia-dependent, nitrite-induced extravasation of iron oxide nanoparticles observed herein has implications for the enhancement of conventional and nanotherapeutic drug delivery.

Differentiation of primary central nervous system lymphomas and glioblastomas: comparisons of diagnostic performance of dynamic susceptibility contrast-enhanced perfusion MR imaging without and with contrast-leakage correction

BACKGROUND AND PURPOSE

Contrast leakage results in underestimation of the CBV of brain tumors. Our aim was to compare the diagnostic performance of DSC perfusion MR imaging without and with mathematic contrast-leakage correction in differentiating PCNSLs and glioblastomas.

MATERIALS AND METHODS

Perfusion parameters-CBV, corrected CBV, and leakage coefficient-were measured in enhancing tumor portions and contralateral NAWM of 15 PCNSLs and 20 glioblastomas, respectively. The ratios of CBV and corrected CBV were calculated by dividing the tumor values by those obtained from contralateral NAWM. A paired t test was used to compare tumor K2 and NAWM K2, as well as tumor CBV ratios without and with leakage correction. Comparisons of CBV, corrected CBV, and K2 between PCNSLs and glioblastomas were done by using a 2-sample t test. The diagnostic performance of DSC perfusion MR imaging without and with contrast-leakage correction was assessed with receiver operating characteristic curve analysis.

RESULTS

PCNSLs and glioblastomas demonstrated higher K2 than those in their contralateral NAWM. Corrected CBV ratios were significantly higher than the uncorrected ones for both tumors. PCNSLs had lower CBV ratios (P < .001), lower corrected CBV ratios (P < .001), and higher K2 (P = .001) compared with glioblastomas. In differentiating between PCNSLs and glioblastomas, the area under the curve of the CBV ratio, corrected CBV ratio, and K2 were 0.984, 0.940, and 0.788, respectively.

CONCLUSIONS

PCNSL can be differentiated from glioblastoma with CBV ratios, corrected CBV ratios, and K2. CBV without contrast-leakage correction seems to have the best diagnostic performance in differentiating the 2 tumors.

Early exercise protects the blood-brain barrier from ischemic brain injury via the regulation of MMP-9 and occludin in rats

Early exercise within 24 h after stroke can reduce neurological deficits after ischemic brain injury. However, the mechanisms underlying this neuroprotection remain poorly understood. Ischemic brain injury disrupts the blood-brain barrier (BBB) and then triggers a cascade of events, leading to secondary brain injury and poor long-term outcomes. This study verified the hypothesis that early exercise protected the BBB after ischemia. Adult rats were randomly assigned to sham, early exercise (EE) or non-exercise (NE) groups. The EE and NE groups were subjected to ischemia induced by middle cerebral artery occlusion (MCAO). The EE group ran on a treadmill beginning 24 h after ischemia, 30 min per day for three days. After three-days’ exercise, EB extravasation and electron microscopy were used to evaluate the integrity of the BBB. Neurological deficits, cerebral infarct volume and the expression of MMP-9, the tissue inhibitors of metalloproteinase-1 (TIMP-1), and occludin were determined. The data indicated that early exercise significantly inhibited the ischemia-induced reduction of occludin, and an increase in MMP-9 promoted TIMP-1 expression (p < 0.01), attenuated the BBB disruption (p < 0.05) and neurological deficits (p < 0.01) and diminished the infarct volume (p < 0.01). Our results suggest that the neuroprotection conferred by early exercise was likely achieved by improving the function of the BBB via the regulation of MMP-9 and occludin.

The EPR effect: Unique features of tumor blood vessels for drug delivery, factors involved, and limitations and augmentation of the effect

The enhanced permeability and retention (EPR) effect is a unique phenomenon of solid tumors related to their anatomical and pathophysiological differences from normal tissues. For example, angiogenesis leads to high vascular density in solid tumors, large gaps exist between endothelial cells in tumor blood vessels, and tumor tissues show selective extravasation and retention of macromolecular drugs. This EPR effect served as a basis for development of macromolecular anticancer therapy. We demonstrated methods to enhance this effect artificially in clinical settings. Of great importance was increasing systolic blood pressure via slow angiotensin II infusion. Another strategy involved utilization of NO-releasing agents such as topical nitroglycerin, which releases nitrite. Nitrite is converted to NO more selectively in the tumor tissues, which leads to a significantly increased EPR effect and enhanced antitumor drug effects as well. This review discusses molecular mechanisms of factors related to the EPR effect, the unique anatomy of tumor vessels, limitations and techniques to avoid such limitations, augmenting tumor drug delivery, and experimental and clinical findings.

Reduced pain and inflammation in juvenile and adult rats fed a ketogenic diet

The ketogenic diet is a high-fat, low-carbohydrate regimen that forces ketone-based rather than glucose-based cellular metabolism. Clinically, maintenance on a ketogenic diet has been proven effective in treating pediatric epilepsy and type II diabetes, and recent basic research provides evidence that ketogenic strategies offer promise in reducing brain injury. Cellular mechanisms hypothesized to be mobilized by ketone metabolism and underlying the success of ketogenic diet therapy, such as reduced reactive oxygen species and increased central adenosine, suggest that the ketolytic metabolism induced by the diet could reduce pain and inflammation. To test the effects of a ketone-based metabolism on pain and inflammation directly, we fed juvenile and adult rats a control diet (standard rodent chow) or ketogenic diet (79% fat) ad libitum for 3-4 weeks. We then quantified hindpaw thermal nociception as a pain measure and complete Freund's adjuvant-induced local hindpaw swelling and plasma extravasation (fluid movement from the vasculature) as inflammation measures. Independent of age, maintenance on a ketogenic diet reduced the peripheral inflammatory response significantly as measured by paw swelling and plasma extravasation. The ketogenic diet also induced significant thermal hypoalgesia independent of age, shown by increased hindpaw withdrawal latency in the hotplate nociception test. Anti-inflammatory and hypoalgesic diet effects were generally more robust in juveniles. The ketogenic diet elevated plasma ketones similarly in both age groups, but caused slowed body growth only in juveniles. These data suggest that applying a ketogenic diet or exploiting cellular mechanisms associated with ketone-based metabolism offers new therapeutic opportunities for controlling pain and peripheral inflammation, and that such a metabolic strategy may offer significant benefits for children and adults.

Subtraction method for intravital two-photon microscopy: intraparenchymal imaging and quantification of extravasation in mouse brain cortex

Brain pathologies, including stroke and tumors, are associated with a variable degree of breakdown of the blood-brain barrier (BBB), which can usefully be studied in animal models. We describe a new optical technique for quantifying extravasation in the cortex of the living mouse and for imaging intraparenchymal tissue. Leakiness of the BBB was induced by microbeam x-irradiation. Two fluorescent dyes were simultaneously infused intravenously, one of high molecular weight (fluorescein-labeled dextran, 70 kDa, green fluorescence) and one of low molecular weight (sulforhodamine B, 559 Da, red fluorescence). A two-photon microscope, directed through a cranial window, obtained separate images of the two dyes in the cortex. The gains of the two channels were adjusted so that the signals coming from within the vessels were equal. Subtraction of the image of the fluorescein-dextran from that of the sulforhodamine B gave images in which the vasculature was invisible and the sulforhodamine B in the parenchyma could be imaged with high resolution. Algorithms are presented for rapidly quantifying the extravasation without the need for shape recognition and for calculating the permeability of the BBB. Sulforhodamine B labeled certain intraparenchymal cells; these cells, and other details, were best observed using the subtraction method.

Suppression of endotoxin-induced inflammation by taxol

The pathogenesis of acute lung injury includes transendothelial diapedesis of leukocytes into lung tissues and disruption of endothelial/epithelial barriers leading to protein-rich oedema. In vitro studies show that the microtubule network plays a role in the regulation of endothelial permeability as well as in neutrophil locomotion. It was hypothesised that the microtubule-stabilising agent, taxol, might attenuate inflammation and vascular leak associated with acute lung injury in vivo. The effect of intravenously delivered taxol was assessed using a model of murine lung injury induced by intratracheal lipopolysaccharide (LPS) administration. Parameters of lung injury and inflammation were assessed 18 h after treatment. Intravenously delivered taxol significantly reduced inflammatory histological changes in lung parenchyma and parameters of LPS-induced inflammation: infiltration of proteins and inflammatory cells into bronchoalveolar lavage fluid, lung myeloperoxidase activity, and extravasation of Evans blue-labelled albumin into lung tissue. Taxol alone (in the absence of LPS) had no appreciable effect on these parameters. In addition to lung proteins, intravenous taxol reduced accumulation of leukocytes in ascitic fluid in a model of LPS-induced peritonitis. Taken together, the present data demonstrate that microtubule stabilisation with taxol systemically attenuates lipopolysaccharide-induced inflammation and vascular leak.

Dealing with chemotherapy extravasations: a new technique

Doxorubicin, vincristine, and vinblastine are chemotherapeutic drugs commonly used in the treatment of cancer in pets. It takes technical skill to administer these drugs, because they are caustic sclerotics. If doxorubicin is extravasated into the perivascular tissues, the results may be devastating. The attending nurse and clinician must act vigorously to immediately remove every drop of the drug spilled into the tissues. Unfortunately, little has been written on how to effectively do that, but this paper describes an aggressive technique that can be used to combat such a spill.

A retrospective chart review of risk factors for extravasation among neonates receiving peripheral intravascular fluids

PURPOSE

To identify variables associated with extravasation and resulting tissue damage in neonates with peripheral intravascular therapy.

DESIGN

A retrospective chart review was completed.

SETTING AND SUBJECTS

Randomly selected medical records of 25 neonates admitted to a neonatal intensive care unit from January 2003 through April 2004 and who experienced peripheral intravascular infiltration were examined.

INSTRUMENTS

The Neonatal Tissue Extravasation Tool was created to reflect common descriptive variables of the neonatal population and infused solutions used in their care. Tissue damage was classified with the scale from the Task Force of Pediatric Nursing Research Committee, 1994.

RESULTS

Charts of 15 female and 10 male infants 24 to 39.6 weeks old were reviewed. Extravasation was not significantly related to age, weight, or sex. The most common intravenous medications were total parenteral nutrition (n = 19) and calcium (n = 18). Peripheral intravenous sites were secured with tape. The sites of the infiltrate were the arm (n = 16), foot/leg (n = 5), and scalp (n = 3) (one not recorded). Stages 0 (absence of redness, pain, swelling; flushes with ease) (n = 11) and 4 (severe swelling; blanching, pain, skin breakdown, etc.) (n = 6) were the most common stages. The site of the infiltrate was measured and care described in only 9 neonates.

CONCLUSIONS

The intravascular solutions causing the most extensive damage from extravasation were similar to those reported in other studies. No other potential risk factors were identified, but poor documentation about the extravasation site and management of skin damage hampered data collection via retrospective chart review.

Relation of optical coherence tomography and unusual angiographic leakage patterns in central serous chorioretinopathy

PURPOSE

To investigate the anatomic basis of atypical angiographic leaks in central serous chorioretinopathy (CSC) with optical coherence tomography (OCT).

METHODS

Fluorescein angiography (FA) and OCT were performed in three eyes of three patients (two men, one woman) with CSC. The angiographic leaks were treated with transpupillary thermotherapy (TTT) in two patients with long-standing CSC. The investigations were repeated in the treated patients during follow-up visits.

RESULTS

Clinically, all patients demonstrated typical CSC; the female patient had subretinal fibrin under the detachment. FA showed unusual leakage patterns and OCT revealed bridging tissue connecting the pigment epithelial detachment (PED) to the overlying detached retina in all patients. CSC resolved completely in the two patients who underwent TTT along with normalization of the OCT findings. In one patient re-evaluated before complete resolution of CSC, OCT showed a flattened PED with disappearance of the bridging tissue and persistent serous detachment. FA demonstrated conversion of the previously atypical leak into a classic 'smokestack' configuration. Over the next month, leakage resolved completely. CSC and the anatomical findings persisted in the untreated patient.

CONCLUSION

OCT identified a potential anatomic basis for unusual angiographic leakage pattern in all three cases of CSC evaluated.

Case of skin necrosis due to arginine monohydrochloride extravasation

A 10-month-old child presented with an ulcerated lesion on his right arm. The lesion was caused by arginine monohydrochloride extravasation during growth hormone testing, performed 2 months before. On physical examination, there was a 3 cm x 4 cm oval sore, with a thick fibrous base and turgid, violaceous, raised edges on the dorsal aspect of the child's right hand and wrist. Conservative management with local medications led to complete resolution within 2 months.

High-resolution vascular imaging of the rat spine using liposomal blood pool MR agent

BACKGROUND AND PURPOSE

High-resolution, vascular MR imaging of the spine region in small animals poses several challenges. The small anatomic features, extravascular diffusion, and low signal-to-noise ratio limit the use of conventional contrast agents. We hypothesize that a long-circulating, intravascular liposomal-encapsulated MR contrast agent (liposomal-Gd) would facilitate visualization of small anatomic features of the perispinal vasculature not visible with conventional contrast agent (gadolinium-diethylene-triaminepentaacetic acid [Gd-DTPA]).

METHODS

In this study, high-resolution MR angiography of the spine region was performed in a rat model using a liposomal-Gd, which is known to remain within the blood pool for an extended period. The imaging characteristics of this agent were compared with those of a conventional contrast agent, Gd-DTPA.

RESULTS

The liposomal-Gd enabled acquisition of high quality angiograms with high signal-to-noise ratio. Several important vascular features, such as radicular arteries, posterior spinal vein, and epidural venous plexus were visualized in the angiograms obtained with the liposomal agent. The MR angiograms obtained with conventional Gd-DTPA did not demonstrate these vessels clearly because of marked extravascular soft-tissue enhancement that obscured the vasculature.

CONCLUSIONS

This study demonstrates the potential benefit of long-circulating liposomal-Gd as a MR contrast agent for high-resolution vascular imaging applications.

Treatment of anthracycline extravasation with Savene (dexrazoxane): results from two prospective clinical multicentre studies

BACKGROUND

The purpose of this study was to assess the efficacy and tolerability of i.v. dexrazoxane [Savene (EU), Totect (US)] as acute antidote in biopsy-verified anthracycline extravasation.

PATIENTS AND METHODS

Two prospective, open-label, single-arm, multicentre studies in patients with anthracycline extravasation were carried out. Patients with fluorescence-positive tissue biopsies were treated with a 3-day schedule of i.v. dexrazoxane (1000, 1000, and 500 mg/m(2)) starting no later than 6 h after the incident. Patients were assessed for efficacy (the possible need for surgical resection) and toxicity during the treatment period and regularly for the next 3 months.

RESULTS

In 53 of 54 (98.2%) patients assessable for efficacy, the treatment prevented surgery-requiring necrosis. One patient (1.8%) required surgical debridement. Thirty-eight patients (71%) were able to continue their scheduled chemotherapy without postponement. Twenty-two patients (41%) experienced hospitalisation due to the extravasation. Mild pain (10 patients; 19%) and mild sensory disturbances (nine patients; 17%) were the most frequent sequelae. Haematologic toxicity was common as expected from the fact that the extravasation occurred during a chemotherapy course. Other toxic effects were transient elevation of alanine aminotransferases, nausea, and local pain at the dexrazoxane injection site.

CONCLUSION

Dexrazoxane proved to be an effective and well-tolerated acute treatment with only one out of 54 assessable patients requiring surgical resection (1.8%).

Adverse reactions to intravenous iodinated contrast media: an update

Assessment of patients before intravenous contrast injection can help in detecting predisposing risk factors for adverse reactions to contrast media. Early recognition and treatment of acute adverse reactions can prevent morbidity and mortality (rare).

[Extravasation of cytostatic agents: a serious complication of oncological treatment]

The extravasation of cytostatic agents is a known, serious situation that can easily occur and cause chronic, irreversible damage. The incidence of extravasation ranges from 0.1 %-6.5 %, according to different studies. Many cases of extravasation can be prevented by systematizing the administration techniques for cytostatic agents. We present the clinical and histological characteristics of a series of patients with extravasation lesions. Included in the study were all patients treated with chemotherapy who developed localized lesions in the area of the cytostatic injection after extravasation was detected during administration. The patients were studied and followed up for a three-year period, from January 2000 to December 2003, inclusive. We found nine cases of extravasation among the 2,186 patients who were treated with chemotherapy, which represents an incidence of 0.41 %, and 3.4 % of all chemotherapy-induced skin lesions. The cytostatic agent most often involved was vinorelbine, and the most frequent location was the antecubital fossa. The intensity of the lesions made it necessary to delay the next cycle of treatment in 55 % of the cases. The histological findings varied depending on when the biopsy was done, showing panniculitis with low cellularity together with epidermal lesions attributable to direct cytotoxicity. The best treatment for extravasation is prevention, but when it has already occurred, measures vary depending on the cytostatic drug extravasated and the intensity of the lesions. Conservative measures are advisable before surgery.

Intradiscal cement leak following percutaneous vertebroplasty

STUDY DESIGN

A retrospective study to detect patients with cement leakage into the disc space following vertebroplasty.

OBJECTIVE

To determine the frequency, causes, and clinical significance of cement leakage into the disc space.

SUMMARY OF BACKGROUND DATA

Much has been written about cement leakage into the epidural space following vertebroplasty but only little about intradiscal leakage.

METHODS

A total of 66 patients with 1 cemented osteoporotic, fractured vertebra between T5 and L5 were followed for at least 2 years. Two of the senior authors (Y.M. and A.P.) evaluated independently cement leakage into the disc space, possible causes were investigated, and the clinical results were evaluated according to patient self-assessment.

RESULTS

Detected in 27 patients, cement leakage into the disc space did not negatively affect patient satisfaction with the procedure. In 7 of these patients, leakage occurred through an intravertebral vacuum cleft and, in 8, through a perforation of the endplate created by the needle tip. In only 2 patients was cement found to cross the height of the vertebral body and leak into the contralateral disc.

CONCLUSIONS

Apart from iatrogenic endplate perforation, cement extravasation into the disc space was always found to occur through the fractured endplate or a vacuum cleft. Placing the needle tip far from the fractured endplate and using more solid cement appear to decrease the risk of leakage.

Relative cerebral blood volume maps corrected for contrast agent extravasation significantly correlate with glioma tumor grade, whereas uncorrected maps do not

BACKGROUND AND PURPOSE

Relative cerebral blood volume (rCBV) estimates for high-grade gliomas computed with dynamic susceptibility contrast MR imaging are artificially lowered by contrast extravasation through a disrupted blood-brain barrier. We hypothesized that rCBV corrected for agent leakage would correlate significantly with histopathologic tumor grade, whereas uncorrected rCBV would not.

METHODS

We performed dynamic T2*-weighted perfusion MR imaging on 43 patients with a cerebral glioma after prebolus gadolinium diethylene triamine penta-acetic acid administration to diminish competing extravasation-induced T1 effects. The rCBV was computed from non-necrotic enhancing tumor regions by integrating the relaxivity-time data, with and without contrast extravasation correction by using a linear fitting algorithm, and was normalized to contralateral brain. We determined the statistical correlation between corrected and uncorrected normalized rCBV and histopathologic tumor grade with the Spearman rank correlation test.

RESULTS

Eleven, 9, and 23 patients had WHO grades II, III, and IV glioma, respectively. Mean uncorrected normalized rCBVs were 1.53, 2.51, and 2.14 (grade II, III, and IV). Corrected normalized rCBVs were 1.52, 2.84, and 3.96. Mean absolute discrepancies between uncorrected and corrected rCBVs were 2% (0%-15%), 16% (0%-106%), and 74% (0%-411%). The correlation between corrected rCBV and tumor grade was significant (0.60; P < .0001), whereas it was not for uncorrected rCBV (0.15; P = .35).

CONCLUSION

For gliomas, rCBV estimation that correlates significantly with WHO tumor grade necessitates contrast extravasation correction. Without correction, artificially lowered rCBV may be construed erroneously to reflect lower tumor grade.

Extensive cerebrospinal fluid enhancement following gadolinium chelate administration: possible pathogenesis

Diffuse cerebrospinal fluid (CSF) enhancement following gadolinium administration is a rarely recognized phenomenon, and its mechanism is not fully understood. We report two cases of diffuse CSF enhancement following gadolinium administration and review the literature. We conclude that the contributing factors of this phenomenon include blood-CSF barrier disruption, increased dosage, impair renal clearance, delayed imaging after contrast administration, and use of different pulse sequences.

RENAL CRYOABLATION AND RADIO FREQUENCY ABLATION: AN EVALUATION OF WORST CASE SCENARIOS IN A PORCINE MODEL

PURPOSE

Although ablative technologies, including radio frequency (RF) ablation (RFA) and cryoablation (CA), are being used to treat renal masses, complications associated with injury to vital renal structures are not well understood. We investigated these worst case scenarios by deliberately targeting vital renal structures with CA or RFA in a porcine model.

MATERIALS AND METHODS

Following surgical exposure of the right kidney in female pigs a cryoneedle or an RF probe was deliberately placed under visual and ultrasound guidance in the renal pelvis (CA in 5 pigs and RFA in 7), major calix (CA and RFA in 5 each) or subsegmental renal vessels (CA in 5 pigs and RFA in 7). Cryo-energy or RF energy was then applied to create a 3 cm lesion. After 10 days the kidneys underwent gross and histological examination for urine and blood extravasation, cell death and injury. Ex vivo retrograde pyelography was performed to evaluate for urinary fistulas.

RESULTS

All pigs tolerated the treatment and no procedure related deaths occurred. No significant bleeding was noted. RFA and CA created reproducible lesions and areas of cell death and necrosis. Despite significant intentional injury to the collecting system no urinary fistulas were demonstrated in CA specimens (0 of 15). In contrast, damage to the renal pelvis (4 of 7) by dry (3 of 4) or wet (1 of 3) RFA was associated with a high likelihood of urinary extravasation.

CONCLUSIONS

This short-term study demonstrates that CA is safe, effective and not associated with urinary extravasation. In contrast, RFA to the renal pelvis is associated with urinary extravasation. Further studies are needed to support these findings.

Wound Care Issues in the Patient with Cancer

As cancer continues to represent a major health problem in the United States and in other developed countries, MCWs will continue to represent a complex problem for patients and health care professionals alike. Goals of care may range from healing to palliation, depending on the underlying pathology and patient preferences regarding their personal goals of wound or disease management. Palliative wound care should focus on patient comfort and quality of life as the goals, instead of wound. As evidence related to wound healing, products, and technology continues to increase,nurses can be at the forefront of putting into practice the science of wound healing for the benefit of patients.

Local and reversible blood-brain barrier disruption by noninvasive focused ultrasound at frequencies suitable for trans-skull sonications

The purpose of this study was to test the hypothesis that burst ultrasound in the presence of an ultrasound contrast agent can disrupt the blood-brain barrier (BBB) with acoustic parameters suitable for completely noninvasive exposure through the skull. The 10-ms exposures were targeted in the brains of 22 rabbits with a frequency of 690 kHz, a repetition frequency of 1 Hz, and peak rarefactional pressure amplitudes up to 3.1 MPa. The total exposure (sonication) time was 20 s. Prior to each sonication, a bolus of ultrasound contrast agent was injected intravenously. Contrast-enhanced MR images were obtained after the sonications to detect localized BBB disruption via local enhancement in the brain. Brain sections were stained with H&E, TUNEL, and vanadium acid fuchsin (VAF)-toluidine blue staining. In addition, horseradish peroxidase (HRP) was injected into four rabbits prior to sonications and transmission electron microscopy was performed. The MRI contrast enhancement demonstrated BBB disruption at pressure amplitudes starting at 0.4 MPa with approximately 50%; at 0.8 MPa, 90%; and at 1.4 MPa, 100% of the sonicated locations showed enhancement. The histology findings following 4 h survival indicated that brain tissue necrosis was induced in approximately 70-80% of the sonicated locations at a pressure amplitude level of 2.3 MPa or higher. At lower pressure amplitudes, however, small areas of erythrocyte extravasation were seen. The electron microscopy findings demonstrated HRP passage through vessel walls via both transendothelial and paraendothelial routes. These results demonstrate that completely noninvasive focal disruption of the BBB is possible.

[Visualization of bridging veins by means of postmortem computed tomography]

At autopsy, visualization of lesions of the bridging veins, a frequent source of subdural bleeding, is difficult due to their anatomical localization. On the other hand their demonstration is of great importance for the assignment to a chronologically defined trauma. For this reason a postmortem method using computed tomography was developed to visualize the intracranial venous system by means of X-ray contrast media. In subdural bleedings, in which the skull had not been opened up, ruptured vessels could be accurately localized with this method, so that targeted dissection was possible during the subsequent autopsy.

Full-thickness skin necrosis after arginine extravasation--a case report and review of literature

The arginine test is highly useful in the evaluation of short-stature children and adolescents. Extravasation of arginine can cause full-thickness skin necrosis that requires serious surgical intervention with aesthetic and functional sequellea. The authors describe a case of distal forearm skin necrosis caused by arginine extravasation that was treated by wide debridement and a combination of groin flap and later with split-thickness skin graft. The authors emphasize the need for early and active management of arginine extravasation injuries.

Computed tomography and magnetic resonance imaging in the assessment of acute pancreatitis

BACKGROUND & AIMS

This study aimed to compare the accuracy of magnetic resonance imaging (MRI) with computed tomography (CT) in assessing acute pancreatitis (AP) and to explore the correlation between MRI findings and clinical outcome.

METHODS

Patients with AP were investigated by contrast-enhanced CT and MRI on admission and 7 and 30 days thereafter. MRI was performed with intravenous secretin and contrast medium. Balthazar's grading system was used to measure CT and MRI severity indices (CTSI and MRSI, respectively).

RESULTS

Thirty-nine patients (median age, 47 years; range, 15-86) were studied. AP was of biliary etiology in 19 patients (49%). On admission, AP was assessed clinically as severe in 7 patients (18%). A strong correlation was demonstrated between CTSI and MRSI on admission and 7 days later. MRSI on admission correlated with the following: the Ranson score, C-reactive protein levels 48 hours after admission, duration of hospitalization, and clinical outcome regarding morbidity, including local and systemic complications. Considering the Ranson score as the gold standard, MRI detected severe AP with 83% (58-96, 95% CI) sensitivity, 91% (68-98) specificity vs. 78% (52-93) and 86% (63-96) for CT. Magnetic resonance cholangiopancreatography after i.v. secretin injection showed pancreatic duct leakage in 3 patients (8%).

CONCLUSIONS

MRI is a reliable method of staging AP severity, has predictive value for the prognosis of the disease, and has fewer contraindications than CT. It can also detect pancreatic duct disruption, which may occur early in the course of AP.

Extravasation of calcium gluconate concomitant with osteomyelitis in a neonate

Extravasation of calcium gluconate is not an uncommon complication in neonatal units, which may result in skin and soft tissue inflammation, injury and even infection. We report an 11-day-old preterm infant who developed osteomyelitis at an infiltrated intravenous site through which calcium gluconate was infused. The patient was initially treated conservatively as a simple calcium-infiltrate. Clinical condition deteriorated until proper antibiotic treatment was given. We exclude other possible causes and assume that calcium-infiltrate had an important role in the pathogenesis. We conclude that osteomyelitis should be considered in a patient with calcium extravasation whose soft tissue inflammation does not improve as expected. Furthermore, using a diluted calcium solution and checking the insertion site frequently in order to identify extravasation earlier would prevent the complication.

Ultrasound agents may open the blood-brain barrier in rats and aggravate pathologic consequences of experimental head trauma

Unilateral intracarotid injection of contrast agents may considerably destabilize the blood-brain barrier in rats. This leads to vasogenic edema in the ipsilateral hemisphere. Mortality and extravasation increased significantly when administration of these ultrasound contrast agents was followed by mild traumatic brain injury. Direct administration to the cerebral circulation is, therefore, indicative for edema-related pathology and may amplify the consequences of experimental neurotrauma.

Totally implantable venous-access ports: local problems and extravasation injury

Totally implantable venous-access ports (TIVAPs) are valuable instruments for long-term intravenous treatment of patients with cancer, but implantation and use of these devices are each associated with complications. In addition to the perioperative problems, long-term complications can arise; these can be classified in five categories-catheter malfunction, catheter-related venous thrombosis, catheter-related infection, port-related complications, and extravasation injury. Such complications reduce the benefits of reliable access to the venous system in patients with malignant tumours. The vast majority of such disadvantages are attributable to inexpert handling of ports and, therefore, should be avoidable. TIVAP placement procedures and TIVAP complications are discussed in this review, with special emphasis on local problems and extravasation injuries. To obtain maximum benefit from TIVAPs, all health-care personnel must be familiar with the use and routine maintenance procedures of the devices and treatment options for catheter-related complications.

Effects of heparin fractions on the prevention of skin necrosis resulting from adriamycin extravasation: an experimental study

Extravasation of a chemotherapeutic agent is one of the most frequent complications in cancer patients. Full-thickness skin necrosis often occurs after extravasation. Alternative approaches to treatment are local wound care, elevation, and hypothermia. It was shown that heparin prevents skin necrosis. In this experimental study, the effects of heparin fractions on the prevention of skin necrosis were compared by applying an extravasation model of Adriamycin in rats. Forty Sprague-Dawley male rats weighing 250 to 300 g were used. A total of 0.3 ml doxorubicin hydrochloride was administered subcutaneously to all rats. Ten minutes later, in the control group (group I), 1 ml normal saline was administered subcutaneously. In the first experimental group (group II), 100 U per day heparin sodium was administered in a volume of 1 ml subcutaneously. In the second experimental group (group III), nadroparin calcium (5 anti-Xa U per kilogram per day) was administered. In the third and last experimental group (group IV), dalteparin sodium (5 anti-Xa U per kilogram per day) was administered. All drugs were administered for 2 weeks. Necrotic areas were measured 4 weeks later. Statistical analysis was performed using the Kruskal-Wallis analysis of variance and the Mann-Whitney test. Heparin fractions caused a decreased ulcer rate and size than controls ( < 0.05). There was no superiority among heparin fractions. The authors think that low-molecular weight heparins are preferred, considering the higher risk of bleeding with unfractionated heparin.

Local tissue toxicity in response to extravascular extravasation of magnetic resonance contrast media

RATIONALE AND OBJECTIVES

The relative toxicities of the gadolinium chelates currently available in the United States were compared when extravasated in soft tissue. The increasing use of these contrast agents in higher volumes and at faster injection rates, often with a power injector, was a principal motivation for this research.

METHODS

Gadopentetate dimeglumine (Magnevist), gadoteridol (ProHance), gadodiamide (Omniscan), and gadoversetamide (Optimark) were evaluated at standard concentration and compared with a control (physiologic saline) and the conventional ionic radiographic contrast medium meglumine diatrizoate (Renografin 60). Each mouse received a subcutaneous injection in the hindlimb of 0.3 mL of contrast or saline. There were 6 experimental groups, with 15 animals in each group. The individual performing the injection was blinded to the identity of the contrast agent used in each mouse. After 48 hours, the mice were killed and tissue samples obtained for histopathology. A veterinary pathologist, also blinded to the agent injected, graded the degree of damage seen on microscopic examination.

RESULTS

Of the four MR contrast agents, gadopentetate dimeglumine caused the greatest tissue damage, and gadoteridol and gadodiamide-the two lowest osmolar agents-the least. The difference was statistically significant in terms of both inflammation (P = 0.0008 for gadoteridol, and P = 0.006 for gadodiamide) and necrosis (P = 0.0067 for gadoteridol, and P = 0.031 for gadodiamide), when these agents were compared with gadopentetate dimeglumine. In regard to the control experiments, for all three variables (necrosis, edema, and inflammation), there was no statistically significant difference between the results with gadoteridol or gadodiamide and those with saline. In terms of both edema and inflammation, the effect of gadopentetate dimeglumine, although less, could not be differentiated with any statistical significance from that of meglumine diatrizoate. Gadoversetamide, which has an osmolality between the ionic agent (gadopentetate dimeglumine) and the other two nonionic agents, caused a reaction that could not be differentiated from that seen with gadopentetate dimeglumine for both necrosis and edema. Only in the scoring of inflammation was the effect less using gadoversetamide compared to gadopentetate dimeglumine with any statistical significance (P = 0.021).

CONCLUSIONS

The risk of tissue damage due to extravasation is not widely appreciated for the gadolinium chelates. Care should be exercised during contrast injection, to avoid inadvertent extravasation and its deleterious consequences, in particular with the two higher osmolar agents (gadopentetate dimeglumine and gadoversetamide).

Plastic surgical management in tissue extravasation of cytotoxic agents in the upper extremity

Extravasation injuries in subcutaneous tissues during peripheral intravenous administration can result in extensive soft-tissue defects. Early treatment (surgical removal of the extravasated material within 24 h) and late treatment (debridement and coverage) are two possible approaches for this kind of injury. Eighteen patients who suffered a significant extravasation injury were treated surgically between 1/1996 and 5/2001. All patients were referred late (mean 22 days after the event) to our clinic with soft-tissue defects or skin necrosis and were accordingly only amenable to late treatment. The patients with defects over the dorsum of the hand, forearm or cubital fossa area underwent debridement, temporary wound coverage and skin grafting or coverage with a local flap. Spotted infiltrating lesions and necrosis are typical histologic features of a cytotoxic agent extravasation. A safe margin of resection is only achievable with a wide three dimensional excision. The healing time of defects was a mean of 15 days after either skin grafting or flap coverage with no significant difference between the two differing treatment groups. Early referral of patients with extravasation injuries to a specialized department for plastic and hand surgery may in future enable earlier surgical treatment, reduce time of illness and costs.