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PubMed1993

After the blue toe: prognosis of noncardiac arterial embolization in the lower extremities.

PURPOSE: To better understand the prognosis of atheroembolic disease, we reviewed the outcomes of 41 patients with embolization to the viscera and lower extremities. METHODS AND RESULTS: All cases involved emboli that originated from a radiographically identified proximal arterial source. There were 30 men and 11 women (mean age 65 years; mean follow-up time 2 years), and all had been first treated for this condition within the past 6 years. The overall mortality rate was 17% (7/41) and the rate of recurrent embolization 15% (6/41). To compare outcomes associated with supradiaphragmatic versus subdiaphragmatic disease, we defined two groups: group 1 comprised patients (n = 5) in whom the identified embolic source extended above the diaphragm, and group 2 comprised patients (n = 36) in whom the source remained below the diaphragm. The mortality rates in groups 1 and 2 were 60% (3/5) and 11% (4/36), respectively (p < 0.05). Recurrent embolization was also significantly higher in group 1 (60% vs 8%, p < 0.025). There were two amputations in group 1 and six in group 2 (p = not significant). Group 2 patients were then divided into two subgroups: those with limited disease (n = 19) in which the emboli had a single, radiographically identified source (i.e., aneurysm or single area of ulcerated plaque) and those with diffuse disease (n = 17) in which the emboli had multiple, radiographically identified potential sources. In the subgroup of patients with limited disease, no deaths or episodes of recurrent embolization occurred, whereas four deaths and three episodes of recurrent embolization occurred in the subgroup of patients with diffuse disease. The differences in these outcomes, however, were not statistically significant. Thirty selected patients (one from group 1 and 29 from group 2) underwent operation on or bypass of the imputed lesion. Only one (7%) of these 30 patients had recurrent embolization. In contrast, recurrent embolization was noted in four (36%) of the 11 patients who did not have an operation directed at the lesion (p < 0.025). No significant difference in mortality was found between patients who underwent operation and those who did not. CONCLUSIONS: Patients with atheroemboli have a substantial mortality rate and risk of recurrent embolization, especially if the disease process extends above the diaphragm; but in selected patients, operation may decrease the frequency of recurrence without increasing mortality.

Aged↗
PubMed1995

[Pulmonary embolism and thrombi of the right heart].

In general, there are two types of right heart thrombi diagnosed by echocardiography: mobile and non-mobile thrombi, more often located in the atrium than in the ventricle and a potential source of pulmonary embolism. However, they differ in several points: clinical context, clinical and echocardiographic presentations, embolic potential, prognosis and treatment. The result of peripheral venous thrombosis, mobile thrombus it is usually diagnosed during echocardiographic investigation of pulmonary embolism. The appearances are often that of serpentine thrombus floating in the right heart chambers associated with signs of acute cor pulmonale. It is a marker of imminent and often fatal embolism as it completes a previous and usually severe pulmonary embolism; the mortality is over 40%. It is a contra-indication for pulmonary angiography because of the risk of embolism and a therapeutic emergency. Some groups advocate surgical embolectomy and others thrombolysis. Its precise frequency in the acute stage of pulmonary embolism and its treatment remain to be determined by a prospective, multicentre clinical trial. The adherent non-mobile thrombus is usually implanted on the free wall of the right atrium or the interatrial septum. Its formation, in situ, is due to stasis secondary to decompensated congenital or acquired cardiac disease or to the presence of an intracardiac foreign body such as a pacing wire. It is less likely to cause pulmonary embolism. It decreases or disappears with anticoagulant therapy and the outcome is usually good. The differential diagnosis between a mobile thrombus and a Chiari network, or between an adherent thrombus and a vegetation on a intracardiac pacing wire may be difficult and requires transoesophageal echocardiography. The investigation of pulmonary embolism requires systematic echocardiography, one of the objectives of which is to search for right sided thrombi.

Anticoagulants↗
PubMed1997

[Embolization of iatrogenic renal vascular lesions with coaxial catheters and microcoils].

INTRODUCTION: We report our experience with the superselective embolization of iatrogenic vascular injuries. We used new coaxial catheters and new microcoils to assess their technical features and efficacy. MATERIALS AND METHODS: Diagnostic angiography by catheterization of the main renal artery was performed in 7 patients with suspected renal vascular injury to detect injury presence and site. After super-selective catheterization of the feeding arteries with a coaxial catheter (Tracker 18), we performed embolization with platinum microcoils inserted using a coil pusher. The procedure efficacy was assessed at angiography and by comparing serum hemoglobin and hematocrit levels before and after embolization; posttreatment renal function was also studied. RESULTS: Selective embolization permitted complete occlusion of the arteries feeding the vascular injury in all patients, preserving as much parenchyma as possible. Hemoglobin and hematocrit levels were improved or unchanged after the maneuver (average hemoglobin level before embolization: 9.01 mg/dl versus 9.95 mg/dl after embolization; average hematocrit level before embolization: 27.3% versus 30.06% after embolization). We had no difficulty during microcoil insertion and the coaxial catheter was always stable. CONCLUSION: Superselective embolization of iatrogenic vascular injuries is an effective and definitive treatment. We recommend it in the patients with renal bleeding due to iatrogenic vascular injury after percutaneous diagnostic or therapeutic procedures.

Adolescent↗
PubMed1997

Detection of embolic signals during and after percutaneous transluminal angioplasty of subclavian and vertebral arteries using transcranial Doppler ultrasonography.

OBJECTIVE: Percutaneous transluminal angioplasty (PTA) is accepted as a safe and effective procedure for the treatment of stenotic arterial lesions of various sites. However, distal embolism may cause serious complications in the PTA of cephalic arteries. By monitoring embolic signals using transcranial Doppler (TCD) ultrasonography, we speculated regarding the safety and/or risk of PTA for vertebral and subclavian artery stenosis. METHODS: Twelve consecutive patients undergoing PTA for subclavian and vertebral artery stenosis of atherosclerotic origin were studied. All patients were refractory to initial medical treatment and were considered for PTA. During the PTA procedure, all patients were heparinized. Before, during, and after PTA, TCD monitoring was performed to detect embolic signals for 30 minutes at each time. After PTA, anticoagulant and antiplatelet therapies were continued in all patients. RESULTS: Before, during, and after PTA, a steady flow signal could be obtained from each vertebral artery monitored using TCD ultrasonography. No embolic signals were detected in any patient before angioplasty. During angioplasty, one embolic signal was detected immediately after balloon deflation in 1 of 12 patients. Several embolic signals were detected after the procedure in 6 of 12 patients, but thereafter embolic signals became less frequent in number. Three days after angioplasty, embolic signals were not detected in any patient. There were no serious complications caused by the PTA procedure. CONCLUSION: TCD monitoring may be a useful modality for detection of microemboli during and after PTA in the posterior circulation. We suspected that subclinical microemboli are released from the dilated vessels for 3 days after vertebral and subclavian PTA and that anticoagulant or antiplatelet therapies may prevent embolic complications after the procedure.

Aged↗
PubMed1998

Transarterial embolization of the uterine arteries: patient reactions and effects on uterine vasculature.

BACKGROUND: Therapeutic embolization of the uterine arteries has been successfully used to manage profuse gynecological hemorrhage. In the present study we aimed to investigate whether embolization of uterine arteries may serve as a safe and effective alternative treatment in cases of menorrhagia in fertile and perimenopausal women. As a first step, we have evaluated the methodology, patient reactions and effects on the uterine vasculature. METHODS: The distal part of the uterine artery was embolized with polyvinyl alcohol particles via catheterization of the right femoral artery. Total abdominal hysterectomy was performed the next day. RESULTS: Bilateral embolization in two patients resulted in considerable pain that required morphine analgesic medication and epidural analgesia. One patient was embolized unilaterally and experienced only slight discomfort with no need for analgesic medication at all, indicating that unilateral embolization is a well-tolerated method. After embolization, angiography showed stagnant flow in embolized vessels without contrast filling of distal branches. Angiography of the specimen showed normal vascular architecture in non-treated vessels. In treated vessels the main arterial trunks were patent but all smaller branches were occluded. Histology showed that most of the particles lodged in small arteries and that arterioles never showed injected material. CONCLUSION: The study indicates that the procedure involves an efficient occlusion of uterine vessels and that unilateral embolization of uterine arteries is well tolerated.

Adult↗
PubMed1998

Liver embolizations of patients with malignant neuroendocrine gastrointestinal tumors.

BACKGROUND: Patients with neuroendocrine gastrointestinal tumors usually present with inoperable metastatic disease and severe hormonal symptoms. Specific chemotherapy, interferon-alpha (IFN), and somatostatin analogs are established therapies for these patients, but all of them eventually fail. Hepatic arterial embolization can provide reduction of both hormonal symptoms and tumor burden in these patients. METHODS: Between 1981 and 1995, a total of 55 liver embolizations with gel foam powder were performed on 41 patients with histopathologically verified neuroendocrine tumors; 29 had carcinoid tumors and 12 had endocrine pancreatic tumors (EPTs). All patients had received medical treatment, including chemotherapy (n = 18), IFN (n = 31), and octreotide (n = 19), and were experiencing treatment failure when liver embolization was performed at a median of 37 months after diagnosis of liver metastases. Medical treatment was continued after embolization. RESULTS: An overall objective response was noted in 15 of 29 patients with carcinoid tumors (52%). The median duration of effect was 12 months in patients with midgut carcinoid tumors. An overall objective response was observed in 6 of 12 patients with EPTs (50%), with a median duration of effect of 10 months. Adverse events were observed, and, in agreement with earlier reports, the rate of serious complications was 10%. Survival analyses showed a median survival of 80 months and a 5-year survival rate of 60% from the performance of embolization on patients with midgut carcinoid tumors, whereas for patients with EPTs the median survival from embolization was only 20 months. CONCLUSIONS: Liver embolizations performed relatively late in the clinical course in our series appeared to be as effective as "early" embolizations in other series of patients with carcinoid tumors. The results for those with EPTs were poorer, and earlier embolizations may result in better outcomes for these patients. Considering the morbidity associated with the procedure, it is imperative to select patients according to extent of liver involvement, severity of carcinoid heart disease, and somatostatin receptor status.

Adult↗
PubMedDate not supplied

Experimental evaluation of early and long-term effects of microparticle embolization in two different mini-pig models. Part I: kidney.

PURPOSE: Using a pig model: (1) to evaluate the vascular distribution pattern, including the homogeneity and completeness of the intra-arterial microsphere distribution, of 40-120-microm trisacryl-gelatin microspheres (Embospheres) in acute whole-kidney embolization; (2) to evaluate the durability and biocompatibility of 40-120-microm trisacryl-gelatin microspheres (Embospheres) in chronic partial kidney embolization. METHODS: Twenty-two animals were divided into four groups: group 1 (n = 4) underwent total arterial renal occlusion with immediate euthanasia. Groups 2-4 had chronic superselective and partial renal embolization with increasing follow-up times: group 2 (n = 2), 1 week; group 3 (n = 7), 4 weeks; and group 4 (n = 9), 14 weeks. Key endpoints in group 1 were homogeneity and completeness of acute embolizations. In groups 2-4 the key endpoints were durability of embolization and particle-related inflammation in chronic partial embolizations as assessed by quantitative angiography or histomorphometry. A numerical angiographic occlusion score (0.0 to 4.0, where 3.0 is optimal) was developed to assess and quantify the angiographic durability of superselective embolizations (groups 2-4). RESULTS: In group 1, a relatively homogeneous distribution of the particles from segmental arteries to the precapillary level was shown by histomorphometry. Some particles reached the glomerular vas afferens (10 microm diameter). In groups 2-4, a mild recanalization appeared during follow-up. The immediate average postembolization occlusion score of 3.18 +/- 0.73 was reduced to 1.44 +/- 0.73 (statistically significant). Microscopy revealed subtotal necrosis but no foreign body granuloma formation. The intra-arterial appearance of giant cells closely attaching to the surface of the embolic spheres inside the vessel lumen was noted. Vessel walls showed major ischemic reactions. CONCLUSION: Microspheres 40-120 microm in diameter might achieve total occlusion of the arterial kidney vasculature when injected centrally as a result of their fairly homogeneous distribution. Segmental renal infarction occurs after chronic partial embolization despite recanalizations during follow-up. Only mild specific intra-arterial foreign body reactions were found.

Acrylic Resins↗
PubMed2005

Increased expression and activity of matrix metalloproteinases characterize embolic cardiac myxomas.

Tumor embolism occurs in 30 to 50% of all cases of cardiac myxoma, but the causes are still uncertain. Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade the extracellular matrix (ECM) and play a crucial role in plaque instability and aortic aneurysm development, in addition to cancer and heart failure. To determine whether MMP activity contributes to tumor embolism, we examined 27 left atrium-sided myxomas, 10 of which showed clinical signs of peripheral embolism. Immunohistochemistry (in all cases) and Western blotting, and in situ and in-gel zymography (in four embolic and six nonembolic consecutive tumors) demonstrated higher expression and activity of MT1-MMP, pro-MMP-2, and pro-MMP-9 in embolic myxomas, whereas pro-MMP-1, MMP-3, and TIMP-1 levels were similar to those of nonembolic tumors. Reverse transcriptase-polymerase chain reaction demonstrated that increased MMP activity was due, at least in part, to increased transcription and that TIMP-2 transcripts increased in embolic myxomas. In vitro, embolic tumor cells retained higher MT1-MMP and pro-MMP-2 levels in basal conditions and after stimulation with interleukin-1beta and interleukin-6. Increased MMP synthesis and release correlated with enhanced ECM degradation products containing glycosaminoglycan chains in embolic myxoma tissue. Our results strongly suggest that MMP overexpression may contribute to an excessive degradation of tumor ECM and increase the risk of embolism in cardiac myxomas.

Adult↗
PubMed2000

Angiographic embolization for major haemorrhage after upper gastrointestinal surgery

AIMS: Severe postoperative haemorrhage after upper gastrointestinal surgery is a serious complication. This study examined the effectiveness of selective mesenteric angiography (SMA) in localizing a bleeding point and the ability of angiographic haemostatic methods to control bleeding. METHODS: The case notes of a consecutive series of nine patients undergoing urgent SMA during 1996-1998 were analysed. Examination of angiography suite records confirmed the accuracy of patient identification. SMA was performed 18 times with 13 embolizations in nine individuals (seven men; median age 54 (27-73) years). Patients underwent the following operations: Whipple pancreaticoduodenectomy (four patients), pancreatic necrosectomy (two), total gastrectomy (one), cholecystectomy (one) and splenectomy (one). The median interval from surgery to haemorrhage was 15 (2-49) days. Six patients presented with haematemesis/melaena and three with bleeding from drains. Seven had evidence of shock (systolic blood pressure less than 100 mmHg, pulse more than 100 per min); the mean preprocedure haemoglobin concentration was 59 g/l. A median of 8 (4-14) units of blood were transfused before embolization and 4 (2-9) units after. Ten initial endoscopies were performed in six patients, seven of which revealed a source of bleeding. Endoscopic haemostasis was attempted in five and achieved temporary control of bleeding in two. RESULTS: Angiography revealed a discrete bleeding point in 13 of 18 procedures in eight patients. Where a bleeding point was identified, angiographic embolization using 3-8-mm stainless steel coils (ten) or a combination of coils and gelatin sponge (three) achieved radiological evidence of haemostasis in all cases. Periprocedural complications occurred in one patient with unintentional partial embolization of the right hepatic artery during embolization of an actively bleeding left hepatic artery pseudoaneurysm. Rebleeding occurred in six patients within 48 h. Three rebleeds were successfully managed with repeat SMA and embolization (one patient required a third embolization); the remaining three required surgery. Definitive radiological haemostasis was achieved in six patients. Five of the nine patients died in hospital, two of whom had been successfully embolized. CONCLUSIONS: In this group of patients, endoscopy contributed relatively little to treatment of postoperative haemorrhage. In contrast, SMA identified a bleeding point in eight of nine patients and achieved definitive control of bleeding in six. SMA and embolization appears to have a useful role in patients with this infrequent but potentially lethal complication.

Journal Article↗
PubMed2001

Increased levels of soluble adhesion molecules, E-selectin and P-selectin, in patients with infective endocarditis and embolic events.

AIMS: Inflammation-induced procoagulant changes and endothelial cell activation appear to play an important role in thromboembolic complications of infective endocarditis. Hence, the aim of this study was to compare the plasma levels of soluble adhesion molecules E- and P-selectin in infective endocarditis patients with and without embolic events, and healthy subjects. METHODS AND RESULTS: The study group consisted of 76 consecutive patients (mean age=26 years old, range from 8 to 64 years) with definite infective endocarditis according to the Duke criteria. Thirteen of the patients (17.1%) had embolic events. Transoesophageal echocardiographic examinations were performed on all patients within 3 days of initiation of antimicrobial therapy. Although there was a trend towards a higher rate of vegetations detected in those with embolic events than in those without, this did not reach statistical significance (84.6% vs 80.9%, P>0.05). Significantly larger vegetations were observed in patients with embolic events as compared to those without embolic events (1.4 cm vs 1.0 cm, P=0.03). The mean plasma concentrations of P-selectin were elevated in patients with embolic events as compared to both patients without embolic events and control subjects (58.69+/-7.49 ng x ml(-1)vs 29.65+/-5.69 ng x ml(-1), P=<0.001 and 58.69+/- 7.49 ng x ml(-1) vs 25.82+/-5.38 ng x ml(-1), P<0.001). Similarly, the patients with embolic events had increased plasma levels of E-selectin compared to those without embolic events and the control group (73.15+/-11.47 ng x ml(-1) vs 42.84+/-8.77 ng x ml(-1), P<0.001 and 73.15+/- 11.47 ng x ml(-1) vs 34.23+/-5.92 ng x ml(-1), P<0.001). CONCLUSION: Determination of these membrane activation molecules may provide useful markers with which to identify patients at high thromboembolic risk from infective endocarditis.

Adolescent↗
PubMed1999

A novel hybrid biological embolic material: autologous fibroblast incorporated collagen (FC) beads.

If viable fibroblasts are used as an active ingredient of an embolic material, it is expected that proliferation and extracellular matrix production of fibroblasts incorporated at a vascular lesion will help restore tissues due to endovascular scar formation, resulting in progressive and permanent occlusion. Based on this working principle, we have devised a novel biological embolic material, hybrid fibroblast incorporated collagen (hybrid FC) beads composed of collagen microbeads and autologous fibroblasts harvested from the subcutaneous tissue of the host to be treated. Hybrid FC beads were prepared by culture of fibroblasts harvested from canine subcutaneous tissue on collagen microbeads (diameters ranging from around 100 µm to around 400 µm). Canine kidneys were embolized with either hybrid FC or cell-free collagen beads via a transarterial route. Histological examination up to 6 months after embolization revealed that, although both embolic materials effectively occluded the target vessels at the time of embolization, intravascular scar formation activity at the embolized sites was much more profound in the case of the hybrid FC beads than in that of the cell-free beads. Proliferation of autologous fibroblasts was verified by the expression of alkaline phosphatase activity of gene-transfected fibroblasts at the site of lodgement of the beads. It is expected that, using the novel hybrid biological embolic material, hybrid FC beads used for vascular lesions such as arteriovenous malformations can be treated more effectively to restore tissues, resulting in minimal recanalization which often occurs when synthetic embolic materials are used. Copyright 1999 Harcourt Publishers Ltd.

Journal Article↗
PubMed1993

Preoperative embolization of paragangliomas (glomus tumors) of the head and neck: histopathologic and clinical features.

Forty-eight surgical specimens were examined histologically and the case histories reviewed to determine the histopathologic features of embolized paragangliomas (glomus tumors) in relation to the time interval between embolization and surgery. Different degrees of thrombus formation and of multinucleated foreign body giant cells occurred during the first 7 days after embolization; thereafter, glant cells with active phagocytosis, fragmentation of embolic material, and partial revascularization were observed. Only one third of the tumor vessels were embolized. Complete obliteration of 40% of embolized vessels occurred more than 2 months postembolization. The histologic changes induced by embolization in paragangliomas of the head and neck may be classified in four stages. Histologically, the best time for surgery is within 8 days from embolization; surgery performed more than 8 days following embolization, however, is not compromised by revascularization.

Journal Article↗
PubMed2003

Winter at the alpine timberline. Why does embolism occur in norway spruce but not in stone pine?

Conifers growing at the alpine timberline are exposed to frost drought and freeze-thaw cycles during winter-stress factors known to induce embolism in tree xylem. The two dominant species of the European Central Alps timberline were studied: Norway spruce (Picea abies [L.] Karst) and stone pine (Pinus cembra), which usually reaches higher altitudes. We hypothesized to find embolism only at the timberline and to observe less embolism in stone pine than in Norway spruce due to avoidance mechanisms. Seasonal courses of embolism and water potential were studied at 1,700 and 2,100 m during two winter seasons and correlated to vulnerability (to drought-induced embolism), leaf conductance, and micrometeorological data. Embolism was observed only at the timberline and only in Norway spruce (up to 49.2% loss of conductivity). Conductivity losses corresponded to low water potentials (down to -3.5 MPa) but also to the number of freeze-thaw events indicating both stress factors to contribute to embolism induction. Decreasing embolism rates-probably due to refilling-were observed already in winter. Stone pine did not exhibit an adapted vulnerability (50% loss of conductivity at -3.5 MPa) but avoided critical potentials (minimum -2.3 MPa): Cuticulare conductance was 3.5-fold lower than in Norway spruce, and angles between needles and axes were found to decrease in dehydrating branches. The extent of conductivity losses in Norway spruce and the spectrum of avoidance and recovery mechanisms in both species indicates winter embolism to be relevant for tree line formation.

Acclimatization↗
PubMed1992

Xylem embolism in response to freeze-thaw cycles and water stress in ring-porous, diffuse-porous, and conifer species.

Vulnerability to xylem embolism by freeze-thaw cycles and water stress was quantified in ring-porous (Quercus gambelii Nutt.), diffuse-porous (Populus tremuloides Michx., Betula occidentalis Hook.), and conifer species (Abies lasiocarpa Nutt., Juniperus scopulorum Sarg.). Embolism was measured by its reduction of xylem hydraulic conductivity; it was induced by xylem tension (water-stress response) and by a tension plus a freeze-thaw cycle (freeze response). Conifers showed little (Juniperus) or no (Abies) freeze response even to repeated cycles. In contrast, Quercus embolized more than 90% by freezing at tensions below 0.2 MPa, whereas similar embolism without freezing required tensions above 4.5 MPa. Diffuse-porous trees (Betula, Populus) showed an intermediate freeze response. The magnitude of the freeze response was correlated with conduit volume but occurred at higher tensions than predicted from theory. Large early-wood vessels (2.8 x 10(-9) m(3)) in oak were most vulnerable to embolism by freezing, small vessels in Populus and Betula were intermediate (approximately 7 x 10(-11) m(3)), and tracheids in conifers (about 3 x 10(-13) m(3)) were most resistant. The same trend was found within a stem: embolism by freeze-thawing occurred preferentially in wider conduits. The water-stress response was not correlated with conduit volume; previous work indicates it is a function of interconduit pit membrane structure. Native embolism levels during winter corroborated laboratory results on freezing: Quercus embolized 95% with the first fall freeze, Populus and Betula showed gradual increases to more than 90% embolism by winter's end, and Abies remained below 30%.

Journal Article↗
PubMed2006

Embolism formation during freezing in the wood of Picea abies.

Freeze-thaw events can cause embolism in plant xylem. According to classical theory, gas bubbles are formed during freezing and expand during thawing. Conifers have proved to be very resistant to freeze-thaw induced embolism, because bubbles in tracheids are small and redissolve during thawing. In contrast, increasing embolism rates upon consecutive freeze-thaw events were observed that cannot be explained by the classical mechanism. In this study, embolism formation during freeze-thaw events was analyzed via ultrasonic and Cryo-scanning electron microscope techniques. Twigs of Picea abies L. Karst. were subjected to up to 120 freeze-thaw cycles during which ultrasonic acoustic emissions, xylem temperature, and diameter variations were registered. In addition, the extent and cross-sectional pattern of embolism were analyzed with staining experiments and Cryo-scanning electron microscope observations. Embolism increased with the number of freeze-thaw events in twigs previously dehydrated to a water potential of -2.8 MPa. In these twigs, acoustic emissions were registered, while saturated twigs showed low, and totally dehydrated twigs showed no, acoustic activity. Acoustic emissions were detected only during the freezing process. This means that embolism was formed during freezing, which is in contradiction to the classical theory of freeze-thaw induced embolism. The clustered pattern of embolized tracheids in cross sections indicates that air spread from a dysfunctional tracheid to adjacent functional ones. We hypothesize that the low water potential of the growing ice front led to a decrease of the potential in nearby tracheids. This may result in freezing-induced air seeding.

Cryoelectron Microscopy↗
PubMed2005

Arterial embolization and prophylactic catheterization for the treatment for severe obstetric hemorrhage*.

BACKGROUND: To evaluate indications, efficacy, and complications associated with arterial embolization and prophylactic balloon catheterization in the management of obstetric hemorrhage at a university hospital. METHODS: Twenty-two women underwent arterial embolization between February 2001 and November 2003 for the treatment for primary postpartum hemorrhage resulting from abnormal placentation (n=11), uterine atony (n=7), paravaginal laceration (n=3), and disseminated intravascular coagulopathy (n=1). Blood loss was between 3.2 and 15 l. In seven patients, abnormal placentation was diagnosed prenatally and in these patients balloon catheterization was performed prophylactically before elective cesarean section. RESULTS: Of the seven patients, who underwent prophylactic catheterization, embolization was successful in five resulting in adequate hemostasis. Hysterectomy was performed in three, in two patients for uncontrolled hemorrhage and in one patient for placental invasion to bladder. There were no complications associated with prophylactic catheterization and embolization. The other 15 patients were treated in an emergency setting. In eight patients, embolization was performed as a primary surgery, and it was successful in six. In the other seven patients, hysterectomy was performed as an emergency surgery, but bleeding continued. Of these, in six patients, hemostasis was achieved with embolization. Complications associated with emergency embolization were observed in three patients. These were thrombosis of left popliteal artery, vaginal necrosis, and paresthesia of the right leg. CONCLUSIONS: Arterial embolization is of significant value in treating obstetric hemorrhage. Prophylactic insertion of balloon catheters before cesarean section seems to be a safe and effective method in controlling anticipated bleeding. In patients with persistent bleeding following cesarean section and hysterectomy, embolization could be a primary procedure before re-surgery.

Adult↗
PubMed1999

Fat embolism.

OBJECTIVE: To review the pathophysiology and management of patients with clinical manifestations of fat embolism. DATA SOURCES: A review of studies reported from 1976 to 1998 and identified through a MEDLINE search of the literature on fat embolism and fat embolism syndrome. SUMMARY OF REVIEW: Fat embolism occurs when bony or soft tissue trauma has caused fat to enter the circulation, or in atraumatic disorders where circulating fat particles have coalesced abnormally within the circulation. The fat particles deposit in the pulmonary and systemic circulations, although only 1 - 2% develop a clinical disorder with respiratory, cerebral and dermal manifestations known as the fat embolism syndrome. Rarely, fat embolism produces a fulminant fat embolism syndrome due to mechanical obstruction within the pulmonary circulation causing a severe right heart failure. The fat embolism syndrome is believed to be caused by the toxic effects of free fatty acids liberated at the endothelial layer which cause capillary disruption, perivascular haemorrhage and oedema. The clinical manifestations of respiratory failure, petechiae and a diffuse or focal cerebral disturbance, are characteristic but not pathognomonic of the syndrome. The syndrome is largely self limiting with treatment being symptomatic. Therapy is directed at maintaining respiratory function and largely follows the same principles of management used in patients who have the acute respiratory distress syndrome. Early immobilization of fractures and methods to reduce the intramedullary pressure during total hip arthroplasty have reduced the incidence of operative fat embolisation. Corticosteroids either before or after the development of respiratory or cerebral symptoms have not been shown to be of any benefit. CONCLUSIONS: Fat embolism occurs in many traumatic and atraumatic conditions and is largely asymptomatic. Preventative measures include early immobilization of fractures and methods to reduce intramedullary pressure during surgical manoeuvres. Treatment is largely symptomatic with therapy for respiratory failure similar to that used in management of acute respiratory distress syndrome. Corticosteroids have not been found to be of significant benefit.

Journal Article↗
PubMed2006

Thrombo-embolic and bleeding complications in patients with mechanical valve replacements--a prospective observational study.

BACKGROUND AND OBJECTIVES: Long-term anticoagulation therapy is essential to prevent thrombo-embolic events in patients with mechanical valve replacements. In order to offer indigent patients mechanical heart valve replacement surgery, dedicated anticoagulation clinics are necessary for follow-up. This study assessed the safety and efficacy of lifelong oral anticoagulation therapy in Johannesburg General Hospital mechanical heart valve replacement recipients. The incidence of bleeding and thrombo-embolic complications was documented in three groups of patients with mechanical valve replacements. The groups included patients with aortic valve replacements (AVRs), mitral valve replacements (MVRs) and double (aortic and mitral) valve replacements (DVRs). MATERIALS AND METHODS: A prospective observational study was conducted over a 4-month period. Data on 306 patients attending the Johannesburg General Hospital anticoagulation clinic between 2000 and 2005 were analysed. Of the total patients selected, 205 were assigned to the mechanical valve replacement group (which included 63 patients with AVRs, 93 with MVRs and 49 with DVRs); a control group of 101 nonmechanical valve replacement patients were also included. At each visit the level of anticoagulation was assessed from the international normalised ratio (INR) values, and the presence of bleeding and/or thrombo-embolic complications was documented. RESULTS: There were a total of 51 bleeding and thrombo-embolic complications in the study population. Patients with DVRs had a higher proportion of combined complications (30.61%) than patients with single valve replacements (14.29% in the AVR group and 18.05% in the MVR group) and patients in the control group (12.87%). There were 38 bleeding complications, 30 minor and 8 major. Twelve thrombo-embolic events were documented. Individually, there was no significant difference in thrombo-embolic and bleeding complications between the subgroups. Eighty-two per cent of patients in the mechanical valve replacement group were within the therapeutic range for anticoagulant control (INR 2.5-3.5) v. 54% in the control group (INR 2.0-3.0). Anticoagulant control was of a high quality and was not a contributing factor to the incidence of bleeding and/ or thrombo-embolic complications. CONCLUSION: The finding of a low incidence of bleeding and thrombo-embolic complications in patients with mechanical valve replacements supports the continued placement of mechanical valves in our setting and use of oral anticoagulation therapy at an INR of 2.5-3.5. However the increased risk of both bleeding and thrombo-embolic complications in the DVR group is cause for great concern and warrants further investigation.

Administration, Oral↗