Hemorrhagic Zone Research Articles

Polycyclic rash with persistent eosinophilia

A 56-year-old man with no past medical history presented with dry cough and dyspnea. He was given antibiotics and bronchodilators which did not improve his symptoms. Three years after the initial symptoms began, he developed persistent hypereosinophilia with an absolute eosinophil count as high as 2250 cells/uL. Prednisone (40 mg daily) was initially helpful, but his symptoms returned once the drug was tapered. Subsequently, he developed new myalgias, arthralgias, joint swelling, hives, and polycyclic purpuric plaques with hemorrhagic zones and erythema on his trunk and extremities (Figs 1 and 2).

Intra-Axial Metastatic Angiosarcoma of the Central Nervous System Associated with Anemia, Pulmonary Tuberculosis and Short Survival

Abstract Introduction Angiosarcoma (AG) is a malignant mesenchymal neoplasm that predominantly affects the soft tissues and, to variable degrees, expresses the morphological and functional characteristics of the endothelium. The incidence of sarcomas of the central nervous system (CNS) is low (0.5% to 2.7%), and AGs involving the brain are even rarer. Case Description A 45-year-old male patient presented with complaints of headache, nausea, and vomiting. An examination showed bilateral papilledema and a right lung pleurotomy. The patient's previous history included drug addiction, pulmonary tuberculosis, lung abscess, pleural empyema, and pulmonary artery embolization for severe hemoptysis. Computed tomography/magnetic resonance imaging scans revealed a large intra-axial lesion extending into the right parietal and temporal lobes, with hemorrhagic zones. The patient underwent surgical resection of the lesion. Microscopy showed a poorly-differentiated, high-grade malignant tumor composed of plump/epithelioid cells forming small vascular spaces and solid nests, compatible with AG.In the postoperative period, the patient developed recurrent hemoptysis. A biopsy of the tissues adjacent to the pleurotomy determined the diagnosis of pulmonary AG. At 30 days after the resection, the patient died from hemoptysis, hemothorax, lung atelectasis, and intracranial hypertension related to the recurrence of the brain tumor. Conclusion Angiosarcoma is a rare neoplasia related to short survival due to the high proliferative index, which must be considered in patients presenting hemorrhagic tumors. No specific genetic abnormalities have been described for this neoplasia.

Clinicopathological analysis of 16 cases of pyrrolizidine alkaloids-associated hepatic sinusoidal obstruction syndrome

Objective: To observe the histopathological manifestations of liver biopsy in patients with hepatic sinusoidal obstruction syndrome (HSOS) induced by pyrrolizidine alkaloid (PA). Methods: Patients diagnosed with PA-HSOS from 2012 to 2017 were selected, and the general conditions, liver function indexes, medication history, liver biopsy time, histopathological slides of liver biopsy, and follow-up data of clinical prognosis after 6 months of onset were collected. Clinical staging with clinical data was used to observe the histopathological manifestations of patients at different clinical stages. Wilcoxon rank-sum test, unpaired t-test and univariate linear regression analysis were used for data analysis. Results: A total of 16 cases were collected. Alanine transaminase and aspartate transaminase was 59.25 U/L and 25.50 U/L, 108 U/L and 45 U/L, respectively, after 6 months of onset and follow-up, and the differences were statistically significant. Moreover, total bile acids and albumin was 35 μmol/L and 36.15 μmol/L, and 32.45 g/L and 31 g/L, respectively, and the differences were not statistically significant. PA-HSOS pathological development process was divided into early, middle and late stages. In the early stage, the central lobular sinusoidal endothelium integrity was impaired and the entry of erythrocytes had interspersed thin reticular fibers and perisinusoidal space. In the middle stage (hemorrhagic zone), erythrocytes, reticular fibers and collagen fibers were lysed, densely collapsed and deposited. The cavity of the bloodstream was hyperemic and dilated, and the cavity was covered with sinus endothelial cells. The hepatic plate regenerated around the hemorrhagic zone and some of the hepatic sinuses were decompensated. In the late stage, deposited collagen in the hemorrhagic zone had formed a large fibrous scar, and most of the dilated cavity in the bloodstream was covered with vascular endothelium. The marginal zone hepatic cells were regenerated in two rows and gradually inserted into the fibrous septum. Different hepatic lobular lesions obtained from the same patients liver biopsy tissues were changed at different stages. Hepatic lobule injury proportion with severe internal bleeding in liver biopsy tissue had no relation with the prognosis of patients. Conclusion: In the early stage of PA-HSOS, erythrocytes in the central zone of lobules enter the perisinusoidal space through the damaged sinus endothelium, which is manifested as hepatic plate hemorrhagic necrosis. In the middle and late stage, liver plate regeneration and vascular remodeling occurred, so most of the patients' clinical course was self-limited. Pathological staging and liver biopsy time have an apparent correlation, but the prognosis of patients cannot be judged based on the extent of hemorrhage and injury of biopsy samples.

Curcumin as a potential modulator of M1 and M2 macrophages: new insights in atherosclerosis therapy.

Accumulation of macrophages within the artery wall is an eminent feature of atherosclerotic plaques. Macrophages are influenced by various plaque microenvironmental stimuli, such as oxidized lipids, cytokines, and senescent erythrocytes, and thereby polarize into two main phenotypes called proinflammatory M1 and anti-inflammatory M2 macrophages. In the hemorrhagic zones of atheroma, upon exposure to iron, sequestration of iron by M1 macrophages results in an uncontrolled proinflammatory phenotype impairing wound healing, while M2 macrophages phagocytose both apoptotic cells and senescent erythrocytes. M1 macrophages are prominent phenotype in the unstable plaques, in which plaque shoulder contains macrophages mainly present markers of M1 phenotype, whereas the fibrous cap encompassing the necrotic lipid core content macrophages expressed markers of both M1 and M2 subtypes. The abovementioned findings suggest macrophage modulation as a potent approach for atherosclerosis therapy. Curcumin is a polyphenol dietary derived from turmeric with numerous pharmacological activities. Recent in vitro and in vivo studies have indicated that curcumin exerted lipid-lowering effects, and also can modulate function of different macrophage subsets in various macrophage-involved diseases. The current review aimed to present role of macrophage subtypes in atherosclerosis development and progression, and to understand effect of curcumin on macrophage polarization and foam cell formation in the atherosclerosis lesions. Overall, we would address important targets for macrophage modulation in atherosclerotic plaques.

Perihemorrhagic ischemia occurs in a volume-dependent manner as assessed by multimodal cerebral monitoring in a porcine model of intracerebral hemorrhage.

Changes in the perihemorrhagic zone (PHZ) of intracerebral hemorrhage (ICH) are variable. Different mechanisms contribute to secondary neuronal injury after ICH. This multimodal monitoring study investigated early changes in the PHZ of ICH. Twenty-four swine were anesthetized, ventilated, and underwent monitoring of vital parameters. Next to an intracranial pressure-probe (ICP), microdialysis (MD), thermodiffusion cerebral blood flow (td-CBF), and oxygen probes (PbrO2) were placed into the gray white matter junction for 12h of monitoring. ICH was induced using the autologous blood injection model. Pre-defined volumes were 0ml (sham), 1.5ml ipsilateral (1.5ml), 3.0ml ipsilateral (3.0ml), and 3.0ml contralateral (3.0ml contra). ICP equally increased in all groups after ICH. In the 3.0ml group tissue oxygenation decreased to ischemic values of 9±7mmHg early after 6h of monitoring. This decrease was associated with a significant perfusion reduction from 36±8ml/100g/min to 20±10ml/100g/min. MD correlated with a threefold lactate/pyruvate ratio increase. Measurements in all other groups were unchanged. Multimodal monitoring demonstrates volume-dependent changes of tissue oxygenation, blood flow, and ischemic MD markers in the PHZ independent of increased ICP suggesting early moderate ischemia. No evidence was found for the existence of a perihemorrhagic ischemia in the small hematoma groups.

LIGHT AND TRANSMISSION ELECTRON MICROSCOPICAL CHANGES ASSOCIATED WITH GASTRITIS IN TIGER (PANTHERA TIGRIS)

Three dead tigers were dissected and representative samples from the gastric mucosa, duodenum and livers were taken for histopathology and transmission electron microscope for further investigation of the cause of death. Post-mortum examination showed accumulation of straw in the stomach outlet (Phytobezoar), together with pronounced ulcers, which was surrounded by hemorrhagic zones. Light microscopy showed loss of the gastric mucosal epithelium, necrosis of the gastric glands, hyperemia of the submucosal blood vessels, and lymphocytic and few neutrophils in the submucosa. These changes indicated acute-subacute gastritis. Subcapsular hepatocellular necrosis expressed by hepatocellular lysis, pyknosis and karyorhexis of the hepatocytes nuclei were also observed. Transmission electron microscopical observations showed the presence of intercellular, and interacellular elongated, coiled, and spiral form of Hellicobacter bacteria in close contact with the gastric glandular epithelium. Moreover, rounded-shaped bacteria were observed in association with the helicobacter bacteria. The duodenum revealed also the presence of both types of bacteria. These results suggest mixed infection with the complication of Phytobezoar which cause obliteration of the stomach outlet with chronic constipation and fever, might be responsible for the death of tiger.

Abstract No. 277 - Evaluation of ablation volume stability to non-parallel placement of multiple microwave probes in an in vivo porcine liver model

Purpose Microwave (MW) thermal ablation permits large, uniform burn volumes through synergistic placement of multiple probes; however, proper MW thermal induction requires that the probes be parallel. The stability and reliability of the ellipsoidal ablation volume shape to non-parallel MW probe placement is unknown, yet it is critical to determine when needle repositioning is required. The impact of non-parallelity on multi-probe MW ablation volume is evaluated in an in vivo porcine liver model. Materials and Methods Animal ethics approval was obtained to perform hepatic ablations in pigs under general anesthesia. Two MW probes were inserted under 3D US guidance in parallel, 5°, 10°, and 15° diverging orientations with all tips separated by 1.5cm. Ten minute ablations were performed at 45W. The pig was sacrificed and the liver harvested post-ablation. The harvested liver was imaged with MRI to assess ablation shape prior to histopathological fixation, which causes deformation and volume loss. The ablation volume cross-section was analyzed at both the probe tip and feed point. Results A total of eight ablations were performed on two pigs. Post-ablation hepatic MRI demonstrated excellent histological detail in T1 weighting, where the well marginated hemorrhagic zone separated the coagulation zone from the normal parenchyma. The periphery of the coagulation zone was used for all measurements. The ablation volumes were more lobulated and less spherical as the probe alignment moved from parallel to 5o obliquity. Decoupling of the multi-probe synergistic energy was most evident at 10o divergence, with two lobes within the ablation volume encircling each probe. These effects were largest at the probe tip as compared to the focal point. The ablation length along the probe axis was not substantially affected. Quantative comparisons are within the Table. Conclusion For multiple MW probes, the expected ablation volume shape is not reliable for insertions of ≥5° obliquity, so care should be taken to ensure parallel insertion. Table 1

Néovascularisation choroïdienne sur un ostéome choroïdien : traitement par bévacizumab et suivi par OCT Spectral-Domain

Choroidal osteoma is a rare, ossifying tumor, which, while benign, may be complicated by choroidal neovascularization. An 11-year-old boy presented with blurred vision in the right eye for few days. Fundus examination showed bulky lesion in the posterior pole containing a sub-retinal hemorrhage. The geographic borders and color of the mass were typical of choroidal osteoma despite the unusual macular location. The diagnosis was confirmed by ultrasonography. The patient was treated with three successive intravitreal injections of 1.25 mg/0.05 mL bevacizumab (IVB) under general anesthesia, due to recurrences of neovascular activity. SD-OCT in EDI mode was carried out prior to each injection. SD-OCT before and after each bevacizumab injection confirmed regression of serous retinal detachment (SRD) at various locations throughout the lesion, especially in the hemorrhagic zone. It also allowed us to differentiate the active decalcified zones from the inactive calcified zones and to follow treatment response. The treatment of choroidal neovascularization (CNV) secondary to choroidal osteoma is not well defined. As for other etiologies of CNV, anti-VEGF agents (such as bevacizumab) appear to be effective in regressing CNV and improving visual function. In our young patient, general anesthesia was necessary to administer each injection. SD-OCT allows diagnostic confirmation and follow-up of treatment. EDI mode is helpful in studying the choroid and the osteoma. We report a rare case of macular choroidal osteoma, examined by SD-OCT. CNV required several anti-VEGF injections, with good anatomical and functional results.

Hepatoid carcinoma of the pancreas penetrating into the gastric cavity: A case report and literature review

A 79-year-old Japanese woman was admitted to our hospital for treatment of a pancreatic tumor measuring approximately 7 × 5 cm. The tumor had invaded the left adrenal gland and gastric wall and had penetrated into the gastric cavity. Surgical resection was performed. The tumor was composed of a brown to whitish solid area and a zone of hemorrhage, necrosis, and cystic degeneration resembling the gross features of solid pseudopapillary tumor (SPT). Histologically, the tumor showed a heterogeneous growth pattern with a combination of seat-like, trabecular, papillary and hemorrhagic-necrotic areas in various proportions. The differential diagnoses first considered were acinar cell carcinoma, neuroendocrine carcinoma and SPT with malignant transformation. Immunohistochemistry showed tumor cells were negative for pancreatic exocrine enzymes and endocrine markers. Tumor cells diffusely expressed cytokeratin 19, alpha-fetoprotein, carcinoembryonic antigen and glypican-3, but lacked vimentin or β-catenin expression. Small proportions of tumor cells expressed hepatocyte paraffin-1. Although typical morphological features of well-differentiated hepatocellular carcinoma (HCC) were not distinctly apparent, the tumor morphology partly resembled poorly differentiated HCC. Given these findings and considerations, the tumor was finally diagnosed as poorly differentiated hepatoid carcinoma of the pancreas.

Real-time lesion assessment using a novel combined ultrasound and radiofrequency ablation catheter

Assessment of lesion size and transmurality is currently via indirect measures. Real-time image assessment may allow ablation parameters to be titrated to achieve transmurality and reduce recurrences due to incomplete lesions. The purpose of this study was to visualize lesion formation in real time using a novel combined ultrasound and externally irrigated ablation catheter. In an in vivo open-chest sheep model, 144 lesions were delivered in 11 sheep to both the atria and the ventricles, while lesion development was monitored in real time. Energy was delivered for a minimum of 15 seconds and a maximum of 60 seconds, with a range of powers, to achieve different lesion depths. Twenty-two lesions were also delivered endocardially. The ultrasound appearance was assessed and compared with the pathological appearance by four independent blinded observers. For the ventricular lesions (n = 126), the mean power delivered was 6.1 ± 2.0 W, with a mean impedance of 394.7 ± 152.4 Ω and with an impedance drop of 136.4 ± 100.1 Ω. Lesion depths varied from 0 to 10 mm, with a median depth of 3.5 mm. At tissue depths up to 5 mm, changes in ultrasound contrast correlated well (r = 0.79, R(2) = 0.62) with tissue necrosis. The depth of ultrasound contrast correlated poorly with the depth of the zone of hemorrhage (r = 0.33, R(2) = 0.11), and impedance change correlated poorly with lesion depth (r = 0.29, R(2) = 0.08). Real-time lesion assessment using high-frequency ultrasound integrated into an ablation catheter is feasible and allows differentiation between true necrosis and hemorrhage. This may lead to safer and more efficient power delivery, allowing more effective lesion formation.

Relationship Between Leukocyte Kinetics and Behavioral Tests Changes in the Inflammatory Process of Hemorrhagic Stroke Recovery

In this study, we investigated the inflammatory response to hemorrhagic stroke (HS) as the main mechanism of brain functional recovery. Sprague-Dawley rats (n = 24) underwent surgery with sterile saline (control group, n = 12) and collagenase IV-S (stroke group, n = 12) being injected into the right striatum. White blood cell analysis, histological and immunohistological examination of the brain slices, as well as densitometric analysis of polymorphonuclear and microglial cells/macrophages were correlated with behavioral tests, and the data were subjected to appropriate statistical processing. The results indicate a strong correlation between polymorphonuclear and mononuclear changes in the blood and the zone of hemorrhagic stroke with behavioral tests of functional brain recovery. We propose that the inflammatory response is determined by kinetics of polymorphonuclear and mononuclear cells in both the blood and the hemorrhagic stroke zone. Kinetics of these cells is followed by the restoration of functions, and the maximum functional recovery is observed by the time polymorphonuclear and mononuclear stages have completed. With the development of inflammation and leukocyte kinetics, it is possible to predict functional recovery of hemorrhagic stroke. Improvement of the degree and rate of hemorrhagic stroke functional recovery may be achieved by therapeutic interventions into the inflammatory mechanisms influencing polymorphonuclear and mononuclear cell kinetics.

Intoxication mortelle par Lepiota brunneoincarnata: à propos de 4 cas

We report the case of a collective intoxication by ingestion of a mushroom "Lepiota brunneoincarnata" at the origin of the death of four members of the same family aged between 3and 15year old. We discuss the physiopathology and the prognosis factors of such intoxications through these four observations which highlight the clinical signs, biological disturbances due to the intoxication, autopsy and histology findings. The first observation concerns a six year old girl. She presented an abdominal pain with vomiting and aqueous diarrhea. She died during the early phase of the intoxication (seven hour after the ingestion of the mushroom), death was secondary to an acute dehydration. The three other observations concern children aged between three and fifteen year old. They presented typical phalloïdian syndrome symptoms evolution with first gastro-intestinal and then hepatic signs. They died after a period varying between three and eleven days without being able to profit from a hepatic transplantation. The autopsy findings showed the presence of an important cerebral edema and hemorrhagic zones of the liver in all the cases, the presence of hemorrhagic complications in two cases. Histology investigations showed the presence of a diffuse centrilobular and periportals necrosis.

Descriptive study on ocular survival, visual outcome and prognostic factors in open globe injuries

A prospective observational study was done to assess ocular survival, visual outcome and prognostic factors of open globe injury. Eighty eyes of penetrating trauma between 2004 and 2006 were categorized according to the ocular trauma classification system. Primary repair was done and outcomes were assessed at one, three and six months. The final vision was categorized as per World Health Organization classification of visual impairment. Factors at presentation were evaluated for prognostic value towards visual outcome. Sixty-nine eyes with minimum one month follow-up were included for analysis. Statistical analysis was done using Univariate and Multivariate analysis. We found Grade IV visual acuity (<5/200) at presentation (64%) as the most important factor contributing to poor visual outcome. Statistically insignificant factors were time since injury, cataract, and presence of intraocular foreign body. Ocular survival was 97%. We concluded that initial visual acuity, hyphema, zone and length of injury, retinal detachment and vitreous hemorrhage are statistically significant factors affecting outcome in open globe injuries.

From chronic rhinitis to death: Fatal outcome of nasal polyposis treatment

Introduction Nasal polyposis (NP) is considered to be the state of chronic inflammation of nasal mucosa and sinuses presenting with various nasal symptomatology. In most cases, it is treated conservatively. Recently, functional endoscopic sinus surgery (FESS) was developed as the valuable and advantageous surgical procedure to treat NP. Despite the inherited risks of this procedure, its complication rate is considered to be acceptable compared to potential benefits for the patient. Case Fifty-five-year-old man was admitted to the hospital for surgical removal of the nasal polypus. After the usual pre-surgery procedures, the patient underwent FESS. Under general anesthesia, left sphenoid sinus was opened and cleaned from the imflammatory discharge, polypus was excised, and following the trepanation the left maxillary sinus was left to drain out. Polypus and pieces of sinonasal mucosa were sent to pathohistological analysis, which yielded in diagnosis of inverted sinonasal papilloma. The early postoperative recovery was regular, but 2 h upon the surgery, the patient started to lose consciousness gradually falling into the state of coma. CT scan and angiography of the head revealed pneumocranium, defect of the left ethmoidal sinus, hematoma in the left frontal cerebral lobe, as well as the hemorrhage in all four cerebral ventricles. A series of neurosurgical procedures followed in the next 8 days. Despite the attempts to resolve above complications, the patient remained comatous and died 16 days after the polypectomy. Autopsy revealed the extensive oval-shaped defect on the skull base in the left posterior part of cribrous plate of the left ethmoid bone. The brain appeared swollen and heavily congested, showing the zone of subarachnoidal hemorrhage in basal face of left frontal lobe. Frontal serial sections revealed large intracerebral haematoma in basal periventricular structures of left frontal lobe extending to the whole ventricular system. Apart from the above, most prominent finding was bilateral bronchopneumonia. The cause of death was attributed to bronchopneumonia following the brain trauma, manner of death ruled as violent. Conclusion Although majority of the patients suffering from chronic rhinosinusitis or NP recover well after the endoscopic surgery, the possibility of undesirable outcome must not be ignored. This case calls for assessment of potential medical liability caused by malpractice. Having in mind rather high prevalence of chronic rhinosinusitis and NP, legal aspects of postoperative death should be carefully analyzed.

Clinicopathologic Comparison of Radiofrequency Versus Scalpel Incision for Upper Blepharoplasty

To compare the sensation recovery, scar formation, and histopathologic aspects of upper blepharoplasty eyelid incision performed with radiofrequency or scalpel. In a prospective, randomized, blind, comparative, interventional study, 46 eyelids from 23 subjects underwent upper blepharoplasty using radiofrequency incision on one side and a scalpel on the other side. Exclusion criteria were diseases resulting in peripheral neuropathy such as diabetes mellitus, previous upper eyelid surgery or trauma, and history of skin disease. Eyelid sensation was measured preoperatively and 1 week, 1 month, and 6 to 7 months after surgery by a masked observer. Eyelid scar was evaluated by 2 masked observers at final follow-up. Histologic examination for zone and depth of tissue damage, hemorrhage, and inflammatory cell reaction was performed in a masked fashion on 16 eyelids. The mean patient age was 52 years (SD, 5.48 years). Mean aesthesiometry reading significantly decreased in both groups at all follow-up visits in comparison with preoperative measurement (p = 0.000). Mean sensation recovery was insignificantly (0.2 < p < 0.6) higher in the radiosurgery group at all follow-up visits. Mean scar score was insignificantly (p = 0.055 for observer 1, and 0.241 for observer 2) less in the radiosurgery group. The scar score was not significantly different between Fitzpatrick skin types 3 and 4, scored by either observer. The zone and depth of tissue damage on histopathologic examination was greater in the radiofrequency group. However, the hemorrhage and infiltration of inflammatory cells were the same. There was no significant difference between radiofrequency and scalpel incision in upper blepharoplasty with regard to sensation recovery and scar formation. Histologic zone and depth of tissue damage were greater in the radiofrequency group.

Geno- and Phenotypic Diversity of Avian Isolates of Streptococcus gallolyticus subsp. gallolyticus ( Streptococcus bovis ) and Associated Diagnostic Problems

Recently, strains of Streptococcus bovis were reclassified as Streptococcus gallolyticus. In the present study we describe for the first time an outbreak of S. gallolyticus in a broiler flock. Mortality during the first week was normal (<1%), with a final total mortality at the end of production reaching 4.3%. Specific symptoms were not observed. Postmortem pathology demonstrated enlarged and light spleens and livers accompanied by multifocal irregular necroses surrounded by a hemorrhagic zone. In addition, these birds suffered from arthritis and osteomyelitis. Strains isolated from liver and spleen lesions showed clonality as demonstrated by pulsed-field gel electrophoresis. Compared to strains representing previously derived phylogeny, including the S. bovis-S. equinus complex, the 16S rRNA-derived phylogeny of the strains investigated in this study demonstrated a paraphyletic group (S. gallolyticus) well separated from two monophyletic groups: (i) S. equinus-S. bovis plus S. infantarius and (ii) S. alactolyticus plus S. intestinalis. According to information in GenBank, none of the strains included from the two monophyletic groups have been isolated from birds. Further biochemical analyses, including tannase activity, identified for the first time avian isolates belonging to S. gallolyticus subsp. gallolyticus. However, these investigations also demonstrated a clear heterogeneity with pigeon isolates.

Radiofrequency Thermal Ablation in Canine Femur: Evaluation of Coagulation Necrosis Reproducibility and MRI-Histopathologic Correlation

Our purposes were to determine whether a single application of radiofrequency energy to normal bone can create coagulation necrosis reproducibly and to assess the accuracy of MRI at revealing the extent of radiofrequency-induced thermal bone injury. Using a 200-W generator and a 17-gauge cooled-tip electrode, a total of 11 radiofrequency ablations were performed under fluoroscopic guidance in the distal femurs of seven dogs. Radiofrequency was applied in standard monopolar mode at 100 W for 10 min. During radiofrequency ablation, the changes in impedance and currents were recorded. MRI, including unenhanced T1- and T2-weighted images and contrast-enhanced fat-suppressed T1-weighted images, was performed to evaluate ablation regions. Six dogs were killed on day 4 after MRI and one dog on day 7. In all animals, radiofrequency ablation created a well-defined coagulation necrosis and no significant complications were noted. The mean long-axis diameter and the mean short-axis diameter of the coagulation zones produced were 45.9 +/- 5.5 mm and 17.7 +/- 2.7 mm, respectively. At gross examination, thermal ablation regions appeared as a central, light-brown area with a dark-brown peripheral hemorrhagic zone, which was surrounded by a pale-yellow rim. On MRI, the ablated areas showed multilayered zones with signal intensities that differed from normal marrow on unenhanced images and a perfusion defect on contrast-enhanced T1-weighted images. The maximum difference between lesion sizes on MR images, established by measuring macroscopic coagulation necrosis, was 3 mm. The correlation between the diameter of coagulation necrosis and lesion size at MRI was strong, with correlation coefficients ranging from 0.89 for unenhanced T1-weighted images and 0.97 for unenhanced T2-weighted images to 0.98 for contrast-enhanced T1-weighted images (p < 0.05). Radiofrequency ablation created well-defined coagulation necrosis in a reproducible manner, and MRI accurately determined the extent of the radiofrequency-induced thermal bone injury.

Morphometrical, histopathological, immunohistochemical, and ultrastructural findings in human pulmonary tissue destruction following penetrating low-velocity firearm injuries to the lungs.

This autopsy-based study investigated the morphological correlates of pulmonary tissue destruction following fatal penetrating gunshot wounds to the lungs using morphometry, histology, immunohistochemistry, and scanning electron microscopy on whole human lungs fixed-expanded via formalin inflation. As the residue of temporary cavity formation, mantle-like hemorrhagic destruction zones were seen surrounding the missile track that showed an eccentric, conical extension enlarging toward subpleural lung segments. In addition, circumscribed, satellite-like bleeding zones at distances of up to 5.5 cm beyond the border of the permanent cavity were observed that corresponded to interstitial perivascular hemorrhages around larger and smaller pulmonary vessels on the micro-morphological level. These multifocal hemorrhages within macroscopically unaffected parts of pulmonary tissue at some distance from the actual missile track may represent unrecognized, life-threatening intrapulmonary bleeding sources in survivors, potentially leading to ventilation-perfusion mismatch and progressive lung failure. A further noticeable microscopic and ultrastructural finding was that of club-shaped distensions of ruptured alveolar septa strictly limited to the extent of the temporary cavity. These club-shaped distensions of ruptured alveolar septa seem to represent a special feature of alveolar architectural damage that can be explained by the dynamics of the temporary cavity formation: the radial acceleration and overdistension of tissue during temporary cavitation initiates stretch mechanisms of the displaced tissue, causing the alveolar septa to rupture with subsequent foreshortening and pursing of elastic alveolar fibers.

Fluorescence spectroscopy accurately detects irreversible cell damage during hepatic radiofrequency ablation

A current limitation of hepatic radiofrequency ablation (RFA) is an inability to detect ablation margins in real time. Thermal injury from RFA alters the biochemical properties governing tissue fluorescence. We hypothesized that the changes in hepatic fluorescence measured during hepatic RFA could be used to detect irreversible hepatocyte damage accurately and to determine ablation margins in real time. RFA was performed on healthy pig livers and monitored in vivo simultaneously for fluorescence and temperature by a fiberoptic micro-interrogation probe connected to a spectroscopy system. Ablations were stopped based on previously established real-time fluorescence spectral data, not based on temperature or time. To determine where in the ablated tissue cell death occurred, biopsies for transmission electron microscopy were taken from 4 areas of 3 specimens: (1) nonablated liver, (2) hemorrhagic zone/normal liver interface, (3) hemorrhagic zone/coagulated zone interface, and (4) coagulated zone. In vitro fluorescence emission intensity was determined at each biopsy site. Peak hepatic fluorescence intensity occurred at 470 nm and decreased as RFA progressed. Transmission electron microscopy evidence of irreversible hepatocyte damage occurred at the interface of the coagulation zone and the hemorrhagic zone and correlated with a 87.5% +/- 9% decrease in fluorescence emission intensity. Tissue fluorescent changes from thermal injury were unaffected by tissue cooling. Fluorescence spectroscopy accurately detected hepatocellular thermal injury from RFA in real time and can detect irreversible cell damage during tissue thermal therapy.

Real-time spectroscopic assessment of thermal damage: implications for radiofrequency ablation.

Radiofrequency ablation (RFA) is an evolving technology used to treat unresectable liver tumors. Currently, there is no accurate method to determine RFA margins in real-time during the procedure. We hypothesized that a fiber-optic based spectroscopic monitoring system could detect thermal damage from RFA in real-time. Fluorescence (F) and diffuse reflectance (Rd) spectra were continuously acquired from within the expected ablation zone during canine hepatic RFA using a fiber-optic microinterrogation probe (MIP). The F and Rd spectral feedback were continuously monitored and ablations were stopped based on changes in spectra alone. After each ablation, the MIP tract was marked with India ink and the ablation zone was excised. The relationship of the MIP to the zone of ablation was examined grossly and microscopically. F and Rd spectral changes occurred in three characteristic phases as the ablation zone progresses past the MIP. Phase 1 indicates minimal deviation from normal lives. Phase 2 occurs as the MIP lies within the hemorrhagic zone of the ablated tissue. Phase 3 correlates with complete tissue coagulation. The absolute magnitude of spectral change correlates with the gross and histologic degree of thermal damage. Optical spectroscopy is a technology that allows real-time detection of thermal tissue damage. In this study, both F and Rd spectroscopy accurately defined the advancing hemorrhagic edge of the zone of ablation and the central coagulation zone. These results suggest that F and Rd spectroscopy can be used to create a real-time feedback system to accurately define RFA margins.