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PubMed1983

[Embolization and detached balloon occlusion by the femoral route in craniofacial lesions].

Embolization and detached balloon occlusion by the femoral route were performed in 45 cases: 19 cases of meningiomas, 5 of scalp arteriovenous malformations (AVMs), 4 of dural AVMs, 6 of cerebral AVMs, 8 of facial angiomas and 3 of carotid cavernous sinus fistulas (CCFs); and favorable results were attained. In meningiomas, there is only a short interval between the embolization and the removal of tumor (we usually perform the embolization a couple of days before the removal), and we use Gelfoam as embolus material. We aim at central tumor embolization with small emboli. The embolization reduced bleeding in removing the tumors, simplifying the surgical procedure, and 12 of 19 cases required no blood transfusion. Almost all cases of scalp AVMs, dural AVMs and facial angiomas could most probably be cured only by the embolization without surgery. Gelfoam was the first choice, because it would probably dissolve, and also because it would be relatively safe even if pulmonary embolism might occur as a result of probable passage of its emboli onto the venous side. In recanalized cases, the embolization was performed again with Ivalon, a permanent embolus material. The most important of this procedure is to inject the emboli of the suitable size for each case together with a suitable contrast material at as low a rate as possible under the image intensifier. Embolization by the injection pressure should never be tried, but the emboli be allowed to be carried only on the blood flow to the distal side. And the embolization should be discontinued at the stage when the contrast material has stagnated. CCFs are very good indications for the detached balloon occlusion, while this technic proved to serve for no more than occluding the feeding vessels in cerebral AVMs; in other words, it is indicated in a rather limited range of AVMs. We have encountered no severe complications in any of the cases treated by the embolization and detached balloon occlusion.

Adolescent↗
PubMed1995

Portal vein embolization with steel coils and absolute ethanol: a comparative experimental study with canine liver.

Portal vein embolization (PVE) is expected to have an adjuvant effect on the treatment of human liver tumors with transcatheter hepatic arterial embolization (TAE). In this experimental study, PVE was tried using two kinds of embolic materials, steel coils (coils) and absolute ethanol (ethanol). The aim of this article is to compare the effectiveness between the two methods. Five dogs and 12 dogs were treated with coils and ethanol, respectively. The second order portal branches were embolized. Embolization effects of each embolic material on the hepatic vessels and the liver parenchyma were studied angiographically and histologically. PVE with coils achieved immediate occlusion of the embolized vessels in all dogs. Unexpectedly, unembolized vessels were also constricted and/or obstructed in 4 of 5 dogs during a 4-week follow-up period. Histological examination showed no hepatic necrosis in all dogs. By contrast, in the dogs treated with ethanol, venous occlusion was achieved immediately after embolization with ethanol of 0.4 mL/kg or more. The embolized vessels remained occluded and no obstruction of unembolized vessels was observed until 4 weeks after embolization. Hepatic necrosis was observed in the segments where portal veins were occluded. The degree of parenchymal damage was proportional to the injected ethanol dose. Judging from these results, ethanol is likely to be more suitable than coils as an embolic material for PVE. PVE with coils is often dangerous because unembolized vessels might be occluded unexpectedly. For the clinical use of PVE with ethanol, the appropriate dose of injection should be investigated.

Animals↗
PubMed1996

Repermeation of partially embolized cerebral arteriovenous malformations: a clinical, radiologic, and histologic study.

PURPOSE: To describe the pattern and time course of embolization-related tissue lesions and repermeation of the intranidal cast after endovascular embolization of cerebral arteriovenous malformations (AVMs) with N-butyl cyanoacrylate (NBCA). METHODS: We retrospectively reviewed the records of 26 patients who were treated by endovascular embolization with NBCA and subsequent surgical extirpation to look for embolization-related tissue lesions and repermeation of the cast. A residual flow through the malformation was identified on preoperative angiograms in every case. RESULTS: Pattern and time course of embolization-related tissue lesions were typical. Until 3 months after embolization, repermeation of embolized structures did not occur. In contrast, repermeation was found in every patient who had surgery later than 3 months after the first embolization (n = 13; 50%). In these cases, histologic examination of the resected nidus disclosed capillary structures inside the lumen of embolized vessels. Capillaries were traced immunohistochemically with antibodies against membrane-bound factor VIII. No parameter other than the interval between the first embolization and surgery was found to relate to the repermeation of the cast. CONCLUSION: Intranidal recapillarization can occur later than 3 months after the first embolization with NBCA if total and solid casting of the nidus was not accomplished.

Adolescent↗
PubMed1997

Determination of size of aortic emboli and embolic load during coronary artery bypass grafting.

BACKGROUND: Embolic signals have been detected within both the aortic lumen and the intracranial vasculature during coronary artery bypass grafting. Total numbers of these emboli have been reported. The present study examined the size of individual emboli and the total volume of embolization. METHODS: Using transesophageal echocardiography, we continuously monitored the aortic lumen of 10 patients undergoing isolated coronary artery bypass grafting. We manually analyzed 720,000 individual echo frames over a 4-minute period after the release of aortic clamps to track and to calculate the volume of 657 individual particles. The embolic load for the entire procedure was calculated from mean volume based on analysis of 1,508 particles. We simultaneously monitored the middle cerebral artery using transcranial Doppler ultrasonography and compared numbers of emboli detected by the two techniques. RESULTS: Particle diameter ranged from 0.3 to 2.9 mm (mean, 0.8 mm), and particle volume from 0.01 to 12.5 mm3 (mean, 0.8 mm3). Twenty-eight percent of particles measured 1 mm or more, 44% measured 0.6 to 1.0 mm, and only 27% measured 0.6 mm or less in diameter. Aortic embolic load for the procedure ranged from 0.6 cm3 to 11.2 cm3 (mean, 3.7 cm3). Estimated cerebral embolic load for the procedure ranged from 60 to 510 mm3 (mean, 276 mm3). The fraction of aortic emboli entering the cerebral circulation was very variable (3.9% to 18.1%). Seventy-six percent of the embolic volume after the release of clamps occurred over a 20-second period. Only 1 patient was encephalopathic perioperatively. This patient had the largest estimated cerebral embolic load (510 mm3) and the second largest aortic embolic load (8.4 cm3). CONCLUSIONS: We determined the size of individual intraaortic embolic particles and the total volume of embolization during coronary artery bypass grafting, and found the proportion entering the cerebral circulation to be very variable. The constitution of these particles and the neurologic impairment resulting from such embolization remains to be determined.

Aged↗
PubMed2002

[Clinical characteristics of paradoxical brain embolism associated with isolated pulmonary arteriovenous fistula].

BACKGROUND AND PURPOSE: The right-to-left shunt from pulmonary arteriovenous fistula (P-AVF) with Rendu-Osler-Weber (R-O-W) disease can cause paradoxical brain embolism. However, it has remains unclear whether the isolated P-AVF without Rendu-Osler-Weber (R-O-W) disease is associated with ischemic stroke, in particular, paradoxical brain embolism. Our group previously reported a case with paradoxical brain embolism associated with isolated P-AVF without R-O-W disease in 1996. Furthermore, in 1999, we reported that transcranial Doppler (TCD) with saline contrast medium was useful for identifying the presence of P-AVF as a right-to-left shunt. Therefore, when we have an embolic stroke patient with unknown source, we have performed TCD for detecting P-AVF since 1998. The aim of this study was to investigate the frequency of brain infarction associated with isolated P-AVF without R-O-W disease and to evaluate clinical characteristics including a previously reported case, and to elucidate the stroke mechanism. METHOD AND SUBJECTS: We studied patients with brain infarction associated with isolated P-AVF without R-O-W disease from 642 ischemic stroke patients admitted to our group within 7 days of stroke onset between August 1998 and May 2002. RESULTS: Four patients (0.6%) was diagnosed as having brain infarction associated with isolated P-AVF without R-O-W disease. Clinical characteristics of 5 patients were as follows; 1) all patients were middle aged women (mean, 61 year old), 2) they had no evidences of chronic hypoxia such as cyanosis, dyspnea, and erythrocytosis, 3) all strokes occurred in the morning, 4) the diagnosis of brain embolism was made by routine neuroimaging studies, but no potential cardiac nor arterial sources of emboli were detected, 5) the location of brain infarcts on MRI was more frequently in vertebrobasilar circulation (4 cases) than in carotid circulation (1 case), 6) all patients had pulmonary embolism and 4 suffered from deep venous thrombosis, 7) all patients had a history of brain infarction or transient ischemic attack (TIA) before the present attack, 8) all patients had a single P-AVF and its location was right lower lobe in 4 patients and the left lower lobe in the remaining one patient, and 9) all patients could be treated with catheter embolization of P-AVF without recurrent stroke for 37 months in average (range 2-100 months). CONCLUSION: The isolated P-AVF without R-O-W disease can cause paradoxical brain embolism. Catheter embolization of P-AVF may be effective in prevention for recurrent stroke. We should not overlooked isolated P-AVF as a right-to-left shunt in embolic stroke patients with unknown etiology.

Adult↗
PubMed2026

Surgical Outcomes after Preoperative Embolization of Primary and Secondary Pelvic Bone Tumors.

PURPOSE: To analyze the technical results and safety of preoperative embolization of pelvic bone tumors. MATERIALS & METHODS: Retrospective study analysis of a cohort of patients who underwent preoperative hypervascular, pelvic bone tumor embolization at the authors' institution between January 2008 and January 2025. Preinterventional data, including clinical, radiological, and laboratory findings, procedural angiographic and surgical data, and clinical follow-up data were collected from the patients' electronic medical records. Patient follow-ups were conducted until March 2025 or until the patient's death. RESULTS: Twenty-three patients (11 male patients; mean age of 42 years) underwent uneventful , preoperative embolization for primary (n=15) or metastatic (n=8) pelvic bone tumor resection. A mean of 2.3 tumor feeding arteries were preoperatively embolized with complete tumor blush disappearance in n=13 (56.5%) or near-complete tumor blush disappearance with less than 10% residual tumor blush visualized in n=10 patients (43.4%). Surgical intervention was performed with a mean of 1.7 days after embolization and was associated with a mean of 1.88 L perioperative blood loss. CONCLUSION: Preoperative pelvic tumor embolization is a safe procedure with a mean of more than two feeding arteries identified and embolized. KEY POINTS: · Preoperative embolization is a safe procedure for pelvic bone tumors.. · Angiography identified a mean of 2.3 tumor feeding arteries embolized.. · Complete preoperative angiographic tumoral devascularization was found in 56% of patients.. · Surgical intervention after preoperative tumor embolization was associated with a mean of 1.88L perioperative blood loss.. CITATION FORMAT: · Hubrechts M, Wafa H, Sinnaeve F et al. Surgical Outcomes after Preoperative Embolization of Primary and Secondary Pelvic Bone Tumors. Rofo 2026; DOI 10.1055/a-2942-7451.

Journal Article↗
PubMed1986

Relationship of Xylem Embolism to Xylem Pressure Potential, Stomatal Closure, and Shoot Morphology in the Palm Rhapis excelsa.

Xylem failure via gas embolism (cavitation) induced by water stress was investigated in the palm Rhapis excelsa (Thumb.) Henry. Xylem embolism in excised stems and petioles was detected using measurements of xylem flow resistance: a decrease in resistance after the removal of flow-impeding embolisms by a pressure treatment indicated their previous presence in the axis. Results supported the validity of the method because increased resistance in an axis corresponded with: (a) induction of embolism by dehydration, (b) increased numbers of cavitations as detected by acoustic means, (c) presence of bubbles in xylem vessels. The method was used to determine how Rhapis accommodates embolism; results suggested four ways. (a) Embolism was relatively rare because pressure potentials reach the embolism-inducing value of about -2.90 megapascals only during prolonged drought. (b) When embolism did occur in nature, it was confined to the relatively expendable leaf xylem; the stem xylem, which is critical for shoot survival, remained fully functional. (c) Even during prolonged drought, the extent of embolism is limited by complete stomatal closure, which occurred at the xylem pressure potential of -3.20 +/- 0.18 megapascals. (d) Embolism is potentially reversible during prolonged rains, since embolisms dissolved within 5 h at a pressure potential of 0.00 megapascals (atmospheric), and xylem sap can approach this pressure during rain.

Journal Article↗
PubMed1996

Regional adrenal blood flow responses to adrenocorticotropic hormone after chronic embolization of the fetal placental circulation in sheep.

To ascertain whether repeated hypoxic stress would alter the response of the adrenal cortex to adrenocorticotropic hormone (ACTH), by premature activation of the hypothalamic-pituitary-adrenal axis, we studied fetal sheep subjected to daily reduction of arterial oxygen content by embolization of the fetal placental circulation with 15 microns microspheres for 8 days from about day 124 of gestation (term approximately 147 days) and sham-embolized controls. Starting before the final embolization (or sham-embolization) on day 8, and continuing for 24 h, the fetus was given an intravenous infusion of ACTH1-24 (0.5 microgram/h) or vehicle. Fetal and maternal blood samples were taken for determination of immunoreactive cortisol, and regional adrenal and fetal placental blood flows were measured by the microsphere technique at three time points: 1 h before infusion, 3 h after the start of the infusion (1 h after embolization), and after 24 h of infusion. Prior to infusion of ACTH or vehicle, fetal placental blood flow was lower in microsphere-embolized fetuses than in sham-embolized controls (199 +/ 15 vs 292 +/- 25 ml/min per 100 g tissue; mean +/- S.E.; P<0.01). However, plasma cortisol and adrenal cortical blood flow did not differ between embolized fetuses and controls. Adrenal vascular responses to the 24-h infusion of ACTH were similar in embolized and sham-embolized fetuses. Adrenal cortical blood flow increased 3-fold (P<0.05) due to decreased vascular resistance (P<0.01), with no change in adrenal medullary blood flow. Thus, while daily embolization of the fetal placental circulation caused a sustained decrease in cotyledonary blood flow, no evidence of altered responsiveness of the adrenal cortex to ACTH was found in these experiments.

Adrenal Glands↗
PubMed1993

Reduction of infarct volume by thrombolysis with rt-PA in an embolic rat stroke model.

Thrombolytic therapy with recombinant tissue plasminogen activator was tested in an embolic stroke model. In rats the internal carotid territory was embolized through the internal carotid artery with 50 microliters thrombin-rich (n = 18), 50 microliters thrombin-poor (n = 17) and 20 microliters thrombin poor (n = 13) suspension of arterial-like microthrombi formed under pressure. Hemispheric cerebral blood flow before and after embolization was measured by intra-arterial 133Xe injection method. Fifteen minutes after embolization 19 animals were treated with tissue plasminogen activator 20 mg kg-1, and 22 animals with saline. Carotid angiography displayed the degree of occlusion of the cerebral arterial supply before and after treatment. Brains were evaluated neuropathologically and infarct volume measured. Cerebral blood flow was reduced 72% after embolization with 50 microliters emboli suspension and 32% after embolization with 20 microliters suspension. The comparison of pre- and post-treatment angiography showed some recanalization in the treated animals, control animals had no recanalization. Thrombolytic therapy reduced the infarct volume from 72.8% to 20.9% of embolized hemisphere volume (p = 0.0037) in the 50-microliters thrombin rich-embolized group, from 22.9 to 9.0 (NS) in the 50-microliters-thrombin-poor-embolized group and from 6.6 to 0.0 (NS) in the 20-microliters-embolized group. One third of treated animals recanalized completely and developed smaller (p = 0.03) infarcts than the non-recanalized. No hemorrhagic complications were observed. Early thrombolytic therapy reduced infarct volume after embolic stroke in this model, this effect was dependent upon recanalization.

Animals↗
PubMed2005

Clinical validity of a negative computed tomography scan in patients with suspected pulmonary embolism: a systematic review.

CONTEXT: The clinical validity of using computed tomography (CT) to diagnose peripheral pulmonary embolism is uncertain. Insufficient sensitivity for peripheral pulmonary embolism is considered the principal limitation of CT. OBJECTIVE: To review studies that used a CT-based approach to rule out a diagnosis of pulmonary embolism. DATA SOURCES: The medical literature databases of PubMed, MEDLINE, EMBASE, CRISP, metaRegister of Controlled Trials, and Cochrane were searched for articles published in the English language from January 1990 to May 2004. STUDY SELECTION: We included studies that used contrast-enhanced chest CT to rule out the diagnosis of acute pulmonary embolism, had a minimum follow-up of 3 months, and had study populations of more than 30 patients. DATA EXTRACTION: Two reviewers independently abstracted patient demographics, frequency of venous thromboembolic events (VTEs), CT modality (single-slice CT, multidetector-row CT, or electron-beam CT), false-negative results, and deaths attributable to pulmonary embolism. To calculate the overall negative likelihood ratio (NLR) of a VTE after a negative or inconclusive chest CT scan for pulmonary embolism, we included VTEs that were objectively confirmed by an additional imaging test despite a negative or inconclusive CT scan and objectively confirmed VTEs that occurred during clinical follow-up of at least 3 months. DATA SYNTHESIS: Fifteen studies met the inclusion criteria and contained a total of 3500 patients who were evaluated from October 1994 through April 2002. The overall NLR of a VTE after a negative chest CT scan for pulmonary embolism was 0.07 (95% confidence interval [CI], 0.05-0.11); and the negative predictive value (NPV) was 99.1% (95% CI, 98.7%-99.5%). The NLR of a VTE after a negative single-slice spiral CT scan for pulmonary embolism was 0.08 (95% CI, 0.05-0.13); and after a negative multidetector-row CT scan, 0.15 (95% CI, 0.05-0.43). There was no difference in risk of VTEs based on CT modality used (relative risk, 1.66; 95% CI, 0.47-5.94; P = .50). The overall NLR of mortality attributable to pulmonary embolism was 0.01 (95% CI, 0.01-0.02) and the overall NPV was 99.4% (95% CI, 98.7%-99.9%). CONCLUSION: The clinical validity of using a CT scan to rule out pulmonary embolism is similar to that reported for conventional pulmonary angiography.

Humans↗
PubMed2006

Hepatocyte morphology and kinetics after portal vein embolization.

BACKGROUND: Macroscopic volume changes after portal vein embolization (PVE) can be assessed accurately by computed tomography, but histological changes remain poorly understood. The aim of this study was to clarify hepatocyte morphology and kinetics after PVE. METHODS: The resected livers from 25 patients who underwent extended hepatectomy after PVE and five normal livers were examined using hepatocyte paraffin 1 staining for histomorphometric analysis of hepatocytes. Cell kinetics were determined by Ki-67 staining and terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay. Kupffer cells were examined by CD68 immunostaining. RESULTS: The number of hepatocytes was similar in the embolized lobe, non-embolized lobe and normal liver, but hepatocyte volume was greater in the non-embolized lobe than in the embolized lobe (P = 0.017). The Ki-67 labelling index was higher in the non-embolized lobe (P < 0.001) whereas the apoptotic index was higher in the embolized lobe (P < 0.001). There were more Kupffer cells per unit area in the embolized lobe (P < 0.001). CONCLUSION: Hepatocyte hypertrophy and replication leads to volume enlargement of the non-embolized hepatic lobe, whereas hepatocyte atrophy and apoptosis causes a decrease in volume of the embolized lobe.

Adult↗
PubMedDate not supplied

Embolization of collateral vessels using mechanically detachable coils in young children with congenital heart disease.

Our objective was to evaluate the usefulness of embolizing collateral vessels using mechanically detachable coils (MDCs) in children aged 3 years or younger with congenital heart disease. The subjects were 8 children with congenital heart disease featuring collateral vessels (age 18 days-3 years): 3 with a single ventricle, 2 with the tetralogy of Fallot, 2 with pulmonary atresia, and 1 with a ventricular septal defect. The embolized vessels were the major aortopulmonary collateral artery (MAPCA) in 5 patients, the persistent left superior vena cava in 2, and the coronary arteriovenous fistula in 1. A 4 or a 5 F catheter was used as the guiding device, and embolization was performed using MDCs and other conventional coils introduced through the microcatheter. One patient had growth of new MAPCAs after embolization, and these MAPCAs were also embolized with MDCs. Thus, a total of 9 embolization procedures were performed in 8 patients. Complete occlusion of the collateral vessels was achieved in 8 of 9 procedures (89%). Seven of 8 patients (88%) had uneventful courses after embolization, and MDC procedures appeared to play important roles in avoiding coil migration and achievement of safe coil embolization. One patient who underwent MAPCA embolization showed no improvement in heart function and died 2 months and 19 days later. Embolization of collateral vessels using MDCs in young children with congenital heart disease can be an effective procedure and a valuable adjunct to surgical management.

Child, Preschool↗
PubMed2003

Outcome of acute nonvariceal gastrointestinal haemorrhage after nontherapeutic arteriography compared with embolization.

In acute nonvariceal gastrointestinal (GI) bleeding, immediate arteriographic haemostasis is presently assumed to be a therapeutic advantage. This study assesses whether the risk of a delayed haemostasis, caused by arteriographic findings precluding embolization, might influence patient outcome. We performed a 5.5-year retrospective database search to find all patients referred for arteriography to arrest acute nonvariceal GI bleeding with embolization. The embolized and nonembolized patients were compared for differences in baseline characteristics and bleeding parameters. In both groups the outcome of all endoscopic or surgical interventions after catheterization was included in the follow-up. Clinical success (at 30 days, after all therapy) and in-hospital mortality in the embolized and nonembolized group were compared. We retrieved 63 nonembolized bleedings in 58 patients and 49 embolized bleedings in 49 patients. In the nonembolized group, transfusion need and haemodynamic instability were significantly less severe. Forty-two of 63 (66%) nonembolized bleedings persisted requiring haemostasis by surgery (n=23), endoscopy (n=13) or supportive transfusions. Thirteen of 49 (27%) embolized bleedings recurred and were managed by surgery (n=7), endoscopy (n=3) or transfusion. Overall clinical success rate was 88.9% (56 of 63) in the nonembolized and 87.8% (43 of 49) in the embolized group. Mortality rate was 17.2% (10 of 58) in the nonembolized vs 30.6% (15 of 49) in the embolized patients (P=0.115). Whether or not arteriographic findings afforded the opportunity to embolize, outcome of acute nonvariceal GI bleeding did not differ significantly; however, patients undergoing embolization were more critically bleeding and ill.

Acute Disease↗
PubMed1998

Splenic artery embolization before laparoscopic splenectomy. An update.

BACKGROUND: This study assessed preoperative splenic artery embolization before laparoscopic splenectomy. METHODS: Preoperative splenic artery embolization was used in 26 of 54 patients (48%) undergoing laparoscopic splenectomy. Between 1992 and 1994, this procedure was used in all patients with spleens shorter than 20 cm (group I), except the first two (18/20). An anterior surgical approach was used. After 1994 (group II), embolization was not used for these patients (0/26), and a lateral surgical approach was used. Throughout the study period, all patients with spleens longer than 20 cm had embolization (8/8). RESULTS: Five complications occurred, three related to the use of small-particle embolic material (microspheres, gelatin foam powder). In group I, the conversion rate was lower than that of most current series, largely because of embolization. In group II, similar results were obtained because of experience and a better surgical approach (i.e., lateral). CONCLUSIONS: Preoperative splenic artery embolization is not necessary for spleens shorter than 20 cm. Increased experience and mostly the lateral surgical approach have permitted a shorter operation and a low conversion rate (4%) similar to the rate achieved with embolization and the anterior approach in the initial stages of the study. Embolization is used for 20- to 30-cm spleens. The conversion rate is higher (17%), and blood replacement is required frequently (83%). Despite embolization, laparoscopic splenectomy for spleens longer than 30 cm is futile at this time (100% conversion).

Angiography↗
PubMed1994

Contribution of D-dimer plasma measurement and lower-limb venous ultrasound to the diagnosis of pulmonary embolism: a decision analysis model.

The Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study has shown that clinical evaluation and lung scanning may substantiate or exclude pulmonary embolism with reasonable probability in approximately half of the patients in whom it is suspected; for the remainder, pulmonary angiography is considered the gold standard diagnostic test. We performed a decision analysis to assess the potential of two noninvasive tests, D-dimer plasma measurement and lower-limb B-mode venous ultrasound, for reducing the number of pulmonary angiograms necessary to diagnose pulmonary embolism. Our decision model addresses hypothetical patients in the emergency ward with suspected pulmonary embolism and abnormal lung scan results. Results show that D-dimer measurements of less than 500 micrograms/L could be used reliably to exclude pulmonary embolism in patients with an abnormal but not high-probability (inconclusive) lung scan. D-dimer measurements of greater than 500 micrograms/L have no positive predictive value for pulmonary embolism and should be followed by ultrasound, which may replace pulmonary angiography when it discloses deep venous thrombosis. Pulmonary angiography should be performed when ultrasound is negative because of its presumably low sensitivity for deep venous thrombosis in patients with pulmonary embolism. A D-dimer measurement of less than 500 mu/L does not exclude pulmonary embolism in patients with a high clinical suspicion of pulmonary embolism. On the basis of the results of the PIOPED study, we calculated that the combination of D-dimer measurement and ultrasound might reduce the requirement for pulmonary angiography by one third among patients with inconclusive scan results and intermediate clinical probability of pulmonary embolism.

Angiography↗
PubMed2004

Outcome in patients undergoing unilateral uterine artery embolization for symptomatic fibroids.

AIMS: To evaluate patients undergoing uterine artery embolization for symptomatic fibroids who, for technical reasons, underwent unilateral rather than bilateral embolization. PATIENTS: Prospective data were collected on 109 patients undergoing uterine artery embolization for symptomatic fibroids. Of these, six underwent unilateral embolization. They were followed with ultrasound or magnetic resonance imaging (MRI) at 3, 6 and 12 months. Patients' histories were reviewed and patients were asked to evaluate their symptoms at 3, 6 and 12 months on a scoring system, which scored their pre-embolization symptoms as 10. RESULTS: In one case the patient's symptoms did not change in the first 3 months. This patient underwent a second embolization procedure to occlude the non-embolized uterine artery. In four cases the patients' symptoms had begun to resolve at 3 months and by 12 months the patients no longer required any further treatment. In one case the patient passed a 10 cm fibroid per vagina 2 months post uterine artery embolization. After this the patient had a normal uterus on MRI and no further symptoms. CONCLUSION: Where planned bilateral uterine artery embolization is not possible for technical reasons and a unilateral embolization only is performed a conservative approach is indicated.

Adult↗
PubMed2005

Unexpected donor pulmonary embolism affects early outcomes after lung transplantation: a major mechanism of primary graft failure?

OBJECTIVE: Primary graft failure remains a significant cause of morbidity and mortality after lung transplantation, and its mechanism is not understood. Previously 2 case reports described fatal primary graft failure due to donor-related unexpected pulmonary embolism. This study investigated the incidence, early outcome, and risk factors of unexpected pulmonary embolism in lung transplantation. METHODS: An exploratory retrograde donor lung flush before implantation to diagnose pulmonary embolism (emboli group) or no pulmonary embolism (no-emboli group) was performed in 74 of 122 consecutive lung transplantations. RESULTS: The incidence of macroscopic unexpected pulmonary embolism was 38% (28% clot and 9% fat). In the emboli group, significantly decreased oxygenation (P < .05), increased pulmonary vascular resistance (P < .001), an increased proportion of opacity on chest radiograph (P = .03), prolonged intubation (P < .001) and intensive care unit stay (P < .01), and decreased 1-year survival (P = .03) were seen after transplantation. In multivariate analysis, pulmonary embolism was an independent risk factor for prolonged intubation (hazard ratio, 2.42; P < .01). In logistic regression, death due to trauma with fracture and a smoking history of more than 20 pack-years were significant donor risk factors for pulmonary embolism (adjusted odds ratio, 8.77 and 5.64; P = .02 and .04, respectively). No deleterious effects of the exploratory flush were seen. CONCLUSIONS: Unexpected pulmonary embolism is relatively common, is potentially predicted by donor history (but not by arterial blood gas analysis or chest radiograph), and is associated with primary graft failure. Donor lungs with risk factors of pulmonary embolism should undergo an exploratory flush. When pulmonary embolism is diagnosed, further therapeutic strategies must be considered.

Adult↗
PubMed2005

The influence of weather and environment on pulmonary embolism: pollutants and fossil fuels.

Previous publications have highlighted seasonal variations in the incidence of thrombosis and pulmonary embolism, and that weather patterns can influence these. While medical risk factors for pulmonary thrombo-embolism such as age, obesity, hypercoagulable states, cancer, previous thrombo-embolism, immobility, limb paralysis, surgery, major illness, trauma, hypotension, tachypnoea and right ventricular hypokinesis are not directly implicated regarding environmental factors such as weather, they could be influenced indirectly by these. This would be especially relevant in polluted areas that are associated with a higher pulmonary embolism risk. Routine nuclear medicine lung ventilation/perfusion studies (V/Q scans) of 2071 adult patients referred to the nuclear medicine department of the Royal Surrey County Hospital in Guildford, UK, between January 1998 and October 2002 were reviewed and 316 of these patients were classified as positive for pulmonary embolism with high probability scan on PIOPED criteria. The occurrence of positive scans was compared to environmental factors such as temperature, humidity, vapour pressure, air pressure and rainfall. Multiple linear regression was used to establish the significance of these relations. The incidence of pulmonary embolism was positively related to vapour pressure and rainfall. The most significant relation was to vapour pressure (p=0.010) while rainfall was less significant (p=0.017). There was no significant relation between pulmonary embolism and air pressure, humidity or temperature. It is postulated that rainfall and water vapour may be contributary factors in thrombosis and pulmonary embolism by way of pollutants that are carried as condensation nuclei in micro-droplets of water. In particular, fossil fuel pollutants are implicated as these condensation nuclei. Pollutants may be inhaled by populations exposed to windborne vapour droplets in cities or airports. Polluted vapour droplets may be absorbed by the lung to hasten coagulation cascades in the blood. This may lead to thrombosis and increased pulmonary embolism under high vapour pressure conditions. With combined factors such as pre-existing ill health or immobility on long flights, the risk of thrombosis and consequent embolism might increase substantially.

Adult↗