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PubMedDate not supplied

Embolization of branches arising from the cavernous portion of the internal carotid artery.

Seven patients with vascular disease (four with cavernous and two with transverse sinus dural fistulas and one with a facial arteriovenous malformation, all supplied primarily from cavernous branches of the internal carotid artery) underwent subselective catheterization and embolization. Ten branches were catheterized (seven meningohypophyseal trunks and three inferolateral trunks) and eight branches were embolized. The embolic agents were as follows: polyvinyl alcohol particles in five, hypertonic glucose in two, and liquid adhesive in one. All four cavernous sinus dural fistulas were occluded after embolization. In the two transverse sinus fistulas, the goal of embolization was to obliterate the tentorial supply prior to surgery. This goal was achieved in both cases. In the remaining patient, who had a large facial arteriovenous malformation and recurrent epistaxis, the embolization obliterated the cavernous supply to the nasal cavity and the patient remains hemorrhage-free. Despite one complication, which occurred in the first case when a thrombus formed and dislodged, resulting in an embolic stroke, this study shows that subselective catheterization and embolization can obliterate lesions of the branches arising from the cavernous internal carotid artery.

Adult↗
PubMedDate not supplied

Preoperative embolization of arteriovenous malformations with polylene threads: techniques with wing microcatheter and pathologic results.

The technique with a wing microcatheter system and the pathologic aspects of 11 cerebral arteriovenous malformations (AVMs) surgically resected after embolization with polylene threads are reported. Embolization was performed once in eight patients and twice in three patients. Resected AVMs were submitted both to routine hematoxylineosin examination and to immunohistochemical workup in order to detect the type of immunologic response to thread emboli. In nine cases, 50% or more of the nidus was obliterated by the embolization. After embolization two patients developed reversible neurologic deficits. Pathologic specimens of resected AVMs demonstrated no vascular necrosis; however, a moderate inflammatory response could be seen, characterized by the presence of both mononuclear cells and foreign-body giant cells, associated with the absence of polymorphonuclear infiltrates. A granulomatous fibrotic process was identified that was present from the first month after embolization. Immunohistochemistry indicated that the immunologic response to thread emboli was cell-mediated, not humoral. Embolization with the wing microcatheter with the use of polylene threads proved to be a safe and efficient system of embolization, as a preoperative procedure. Polylene threads are a nontoxic and biocompatible material that can be used as an embolic agent for brain AVMs.

Adult↗
PubMed1989

Pulmonary embolization-induced thymus hyperplasia in rabbits.

The effects of pulmonary embolization on the thymus glands of rabbits were studied morphologically, morphometrically and immunohistochemically. Pulmonary embolization was induced by an intravenous injection of 0.4 ml of Sephadex bead suspension (particle size; 150 to 300 microns, about 2,000 per ml). Both mean weight and volume of the thymus of rabbits killed at 2 weeks after embolization, were about 1.5 times more than those in control animals treated with physiologic saline. Histological examinations showed enlargement of the cortex and medulla of the thymus, and the embolized Sephadex beads in the branches of pulmonary arteries of the lung. The area ratios of medulla/cortex, in the embolization group and in control, were not significantly different. The cells with immunohistochemically positive staining of anti-nuclear antigen of monoclonal antibody of Ki-67, were found in both portions of the medulla and cortex. These data suggest that pulmonary embolization in the rabbit induces true thymic hyperplasia. An intravenous injection of India ink into the right highest intercostal artery revealed the distribution of bronchial arteries, which send the branches to the right lobe of the thymus. In 2 out of 4 animals killed 2 weeks after pulmonary embolization, the left lobe of the thymus as well as the right were stained with the injected ink. As it is known that pulmonary vascular obstruction caused a marked increase in the bronchial blood flow, these data suggest that the thymus blood supply from the bronchial arteries increases in the conditions of pulmonary embolization, which might contribute to thymus hyperplasia.

Animals↗
PubMedDate not supplied

Transcatheter embolization for treatment of acute lower gastrointestinal bleeding.

Treatment of lower gastrointestinal bleeding was attempted in 13 patients by selective embolization of branches of the mesenteric arteries with Gelfoam. Bleeding was adequately controlled in 11 patients with active bleeding during the examination. One patient improved after embolization but bleeding recurred within 24 hours and in another patient the catheterization was unsuccessful. Five patients with diverticular hemorrhage were embolized in the right colic artery four times, and once in the middle colic artery. Three patients had embolization of the ileocolic artery because of hemorrhage from cecal angiodysplasia, post appendectomy, and leukemia infiltration. Three patients had the superior hemorrhoidal artery embolized because of bleeding from unspecific proctitis, infiltration of the rectum from a carcinoma of the bladder, and transendoscopic polypectomy. One patient was septic and bled from jejunal ulcers. Ischemic changes with infarction of the large bowel developed in two patients and were treated by partial semi-elective colectomy, three and four days after embolization. Four other patients developed pain and fever after embolization. Transcatheter embolization of branches of mesenteric arteries is an effective way to control acute lower gastrointestinal bleeding, but still has a significant rate of complications that must be seriously weighed against the advantages of operation.

Adult↗
PubMedDate not supplied

Preoperative embolization of intracranial meningiomas.

The goal of preoperative embolization of intracranial meningiomas is to facilitate their surgical removal by reducing tumor vascularity and decreasing blood loss during surgery. This study is based on personal experience with about 100 embolized meningiomas and on the experience of others. Embolization is performed during the same session as diagnostic angiography. The appropriate embolic materials (absorbable or nonabsorbable) are chosen according to the location of the tumor, the size of the feeding arteries, the blood flow, and the presence of any potentially dangerous vessels (dangerous anastomoses between external carotid artery and internal carotid or vertebral arteries, arteries supplying the cranial nerves). Preoperative embolization appeared to be very useful in large tumors with pure or predominant external carotid artery supply (convexity meningiomas), in skull-base meningiomas, and in middle fossa and paracavernous meningiomas. It was also useful in falx and parasagittal meningiomas receiving blood supply from the opposite side and in posterior fossa meningiomas. CT low densities demonstrated after embolization did not always correlate with necrosis on microscopic examination, and large areas of infarction could be found despite normal CT. Embolic material was found on pathologic examination in 10%-30% of cases; fresh or recent ischemic and/or hemorrhagic necrosis consistent with technically successful embolization was demonstrated in 40%-60% of cases. With careful technique complications are rare.

Embolization, Therapeutic↗
PubMed1980

[Arterial transcatheter embolization in arterio-venous fistulae therapy (aithor's transl)].

In arterio-venous malformations, arterial trans-catheter embolization can be considered as a definitive treatment, a pre-operative devascularizing technique, and a palliative treatment of those not surgically operable malformations. A very important point is choosing the correct way where to introduce the catheter and the embolizing devices. The most known devices are: synthetic fibrin foam (Gelfoam, Spongostan), Gianturco coils, and among the non reabsorbable devices a polyvinylic alcohol foam (Ivalon), the isobutyl-2-cyanoacrylate and silicone. Furthermore detachable balloons and bristle-brushes can be used. Many parameters must be taken into consideration: hemodynamic fluxes of the lesion, type of vascularization, extension of the lesion, aim of the embolization, possible risks. When embolizing large territories, the protocol must foresee several performances for the control of the embolized vessels, the presence of collateral circulation, the extension of the embolization and other afferent arteries to the lesion. Regarding the permanent occlusions it is preferable to utilize fragments of Ivalon, small silicone spheres or liquid silicone; finally, reabsorbable device must be used in the distal embolizations and non reabsorptible in the proximal embolizations. The best results have been achieved in the traumatic lesions where a direct communication exists between an artery and a vein. Among the arterio-venous malformations the best results have been achieved in cranio-facial angiomas with low flux. The possible complications are consequences of ischemia: necrotic musculo-cutaneous, cerebral or troncular changes.

Adult↗
PubMed1995

[Pulmonary embolism: contribution of spiral x-ray computed tomography].

PURPOSE: Spiral computed tomography was compared retrospectively with digital subtraction pulmonary angiography (PA) in 45 patients suspected of having acute or chronic pulmonary embolism. MATERIALS AND METHODS: 45 patients in whom the presence of acute or chronic pulmonary embolism was suspected underwent examination by spiral CT and PA. Diagnosis of pulmonary embolism was based on the direct visualization of intraluminal clots. The study of the agreement between the two methods was based on the Kappa test. In 35 cases, pulmonary emboli were proved. Acute pulmonary emboli were present in 28 cases and chronic in 7 cases. RESULTS: Spiral computed tomography represents an excellent way to detect acute pulmonary embolism. In the chronic form, spiral CT is better than PA to detect intraluminal clots. However, Spiral CT can fail to detect small embole in the peripheral arterial bed. In the 10 patients without pulmonary embolism, the spiral CT proved diagnosis pulmonary oedema (n = 3), lymphangitic carcinoma (n = 4), pleural effusion (n = 3). CONCLUSION: This study suggest that the spiral CT examination is accurate for diagnosis of pulmonary embolism specifically in case of suspected important embolism. The advantages of spiral CT are multiple (non invasive, wide diagnosis spectrum). However, may be a limitation to is use is insufficient distal thrombi detection. This eventuality (5 to 10% in the Pioped study) justify the practice of pulmonary angiography. Spiral CT improvements should reduce this insufficiency in the next future.

Acute Disease↗
PubMed1993

[Diagnosis and embolization of dural arteriovenous fistulae: report of 18 cases].

In the diagnosis and embolization of 18 patients with dural arteriovenous fistulae (DAVF), we found that they had subarachnoid hemorrhage, exophthalmos and craniocerebral murmur. Angiographically, DAVF was classified in to simple type (9 patients) and complex type (9). A total of 34 embolization procedures were performed in this group. solid particle embolization was used in 31 patients and IBCA embolization in 3. Seven patients were embolized once, 7 twice, 2 four times, and 1 five times. Among them, 7 patients were cured, 9 were improved, and in 1 recurred. DSA is importance in the diagnosis of DAVF. To embolize the entrance of fistulae is the key point of the treatment. This technique is safe and effective. Simple DAVF can be cured by intravascular embolization and the complex one can be cured or improved by multiple embolization.

Adult↗
PubMed1993

Prophylaxis of embolic events in patients with atrial fibrillation using low molecular weight heparin.

In patients with chronic nonrheumatic atrial fibrillation, prophylaxis of peripheral arterial embolism is strongly indicated. LMWHs may be an alternative regimen if contraindications for oral anticoagulants are present. In the present study the effect of LMWH on the incidence of embolism in atrial fibrillation has been studied in 75 consecutive patients in comparison to no specific treatment. Patients received one daily injection of the LMWH CY 216 (n = 35) subcutaneously over a period of 6 months. Patients of the control group (n = 40) were observed over the same period of time. In the group treated with CY 216, three embolic events (8.6%) occurred, of which two were localized in the cerebrum. One of these two cerebral embolic events was fatal. In the control group, eight embolic events (20%) occurred, six of these were intracerebral and, of these, five were fatal. An even more pronounced difference between the groups was observed on evaluation of the patients with preceding cerebral embolism. Of 15 patients treated with LMWH, one extracerebral nonfatal embolism occurred. In the control group three of the seven patients (43%) experienced fatal reembolism. The results show that in patients with atrial fibrillation one daily subcutaneous injection of LMWH reduces the incidence of arterial embolism to about one third. No adverse effects were observed during the 6-month treatment period with LMWH.

Aged↗
PubMed1996

Diagnosis of pulmonary embolism by a decision analysis-based strategy including clinical probability, D-dimer levels, and ultrasonography: a management study.

BACKGROUND: Assessment of the clinical probability of pulmonary emboli sm, plasma D-dimer measurement, and lower-limb venous compression ultrasonography have all been advocated in the workup of suspected pulmonary embolism, to minimize the requirement for pulmonary angiography in patients with nondiagnostic lung scans. However, their contribution has not been assessed prospectively. METHODS: Three hundred eight consecutive patients who came to the emergency department with suspected pulmonary embolism were managed according to a diagnostic protocol that included clinical probability assessment, lung scan, and sequential noninvasive tests: plasma D-dimer measurement by enzyme-linked immunosorbent assay (a concentration <500 microgram/L ruled out pulmonary embolism) and lower-limb B-mode venous compression ultrasonography (a positive finding was diagnostic of venous thromboembolism). Patients without pulmonary embolism according to the diagnostic workup did not receive anticoagulant treatment. The safety of this approach was assessed by a 6-month follow-up. RESULTS: of the 308 patients, 106 (34%) had a diagnostic lung scan (normal in 43 and high probability in 63). For the remaining 202 patients, noninvasive workup was diagnostic in 125 (62%). Pulmonary embolism was ruled out by a low clinical probability and a nondiagnostic scan in 48 patients and a D-dimer level less than 500 microgram/L in 53; pulmonary embolism was established by a high clinical probability and a nondiagnostic scan in seven patients and by a finding of a deep vein thrombosis on ultrasonography in 17. Therefore, only 77 of these 202 patients underwent pulmonary angiography (negative in 55; positive in 22). At 6-month follow-up (completed for 99.4% of the study population), only two of the 199 patients in whom the diagnostic protocol had ruled out pulmonary embolism (1.0% [95% confidence interval, 0.1 to 3.6]) had a thromboembolic event (pulmonary embolism, one; deep vein thrombosis, one). CONCLUSIONS: This decision analysis strategy yielded a definitive noninvasive diagnosis in 62% of patients with a nondiagnostic scan and appears to be safe.

Adolescent↗
PubMed1996

[Clinical relevance of fat embolism. Review of the literature].

Fat embolism is since many decades a known and feared complication of fracture of long bones, polytrauma and also in endoprosthetic surgery. During this literature study old and actual experiences about fat embolism, in reference to pathophysiology and diagnosis, were summarized, the actual state of knowledge defined and also different possibilities of reducing fat embolism risks presented and evaluated. In order to estimate the clinical importance of fat embolism, 106 cases of fat embolism (51 clinical and 55 death cases) after hip and knee endoprosthesis were obtained from the literature and retrospectively compared with the results obtained by our own patients. Within a period of 10 years there were in Kantonsspital Liestal 834 primary hip prosthesis and 235 revisions, with 3 deaths. In none of the cases, fat embolism could be shown. Seven patients had respiratory complications after operation, but in only 2 cases the suspicion of fat embolism could not be excluded with certainty. Only 1 case out of 6 patients who had to stay in the intensive care unit after the operation could possibly be connected with intraoperative liberation of fat. At the end of this study simple and clinical proven methods are suggested, which can be helpful to reduce the risks of fat embolism.

Aged↗
PubMed1995

[Severe pulmonary embolism: value of clinical findings and complementary investigations].

Pulmonary embolism is severe when pulmonary arterial obstruction affects right heart haemodynamics and gas exchanges. The clinical signs are not very discriminating in the assessment of the severity of pulmonary embolism: shock, neurological signs and cyanosis are the most suggestive signs of severe embolism. Of the routine complementary investigations, normal blood gases does not exclude the diagnosis of even severe pulmonary embolism but when the pO2 is less than 50 mmHg the vascular obstruction is severe. The risk of haemorrhage due to thrombolysis, commonly used in severe pulmonary embolism, is greater after invasive investigations. This makes it preferable to resort to non-invasive investigation initially, echocardiography, spiral computed tomography or pulmonary scintigraphy, depending on which technique is available in an emergency. In a suggestive clinical setting, echocardiographic signs of right ventricular overload and visualisation of a thrombus in the right heart chambers or pulmonary artery on echocardiography or spiral computed tomography practically confirms the diagnosis of severe pulmonary embolism. Transoesophageal echocardiography is more sensitive than transthoracic echocardiography for the visualization of a thrombus in the pulmonary outflow tract, but is not always inoffensive in those patients in an unstable condition. Lung scintigraphy, when interpretable, provides the diagnosis of pulmonary embolism, shows the anatomic extension and allows follow-up of the outcome. However, the specificity of this investigation is problematic. Pulmonary angiography, coupled with catheterisation of the right heart, remains the reference investigation in the diagnosis of pulmonary embolism and its anatomical diffusion. It is reserved to situations in which echocardiography is difficult and scintigraphy is uninterpretable, notably in patients with previous cardiopulmonary disease.

Blood Gas Analysis↗
PubMed1996

Preoperative endovascular embolization of craniospinal hemangioblastomas.

PURPOSE: To determine whether hemangioblastomas, highly vascular tumors requiring surgery that is potentially complicated by excessive bleeding, can be embolized safely by using interventional techniques that furnish a more avascular surgical field. METHODS: Nine hemangioblastomas involving either the cerebellum or the spinal cord were embolized preoperatively. In each case the feeding artery was selectively catheterized with a microcatheter and the hypervascular tumor nidus was devascularized with polyvinyl alcohol particles. RESULTS: Two patients who had undergone recent attempts as surgical resection at another institution had repeat surgery after endovascular embolization rendered the tumor nidus avascular. At surgery, the tumor was completely removed in one case and markedly debulked in the other. In all nine cases, blood loss after embolization was reported to be less than expected by experienced surgeons. In addition, manipulation and removal of the tumor was reported to be subjectively easier in these embolized tumors. The embolization procedure caused no permanent complications; however, one patient with a posterior fossa hemangioblastoma and hydrocephalus worsened clinically within 12 hours of embolization. This event was thought to be caused by obstructive hydrocephalus resulting from tumor swelling. Emergency craniotomy, ventricular decompression, and surgical resection of the tumor produced complete resolution of the signs and symptoms. CONCLUSIONS: Our results indicate that preoperative embolization of hemangioblastomas is a safe procedure that is useful in aiding surgical resection of these highly vascular tumors.

Adolescent↗
PubMed1996

Preoperative embolization of highly vascular brain tumors: clinical and histopathological findings.

This report concerns the clinical and histopathologic findings in five patients with meningioma and two with hemangioblastoma who underwent embolization with polyvinyl alcohol (PVA) particles before surgery. Angiography revealed loss of tumor stain from the main feeders in all seven patients, with markedly decreased contrast enhancement of computed tomography (CT) and magnetic resonance imaging (MRI) in six of them. Tumor excision was readily accomplished in all instances, with minimal bleeding from the tumor. In the patient operated 1 day after embolization there were almost no necrotic lesions, even though hemorrhage, presumably due to the surgical procedure was noted. Necrotic lesions and island-like residual tumor cells around the vessels were seen in the patient operated two days after embolization. Extended necrotic lesions were noted among patients who underwent surgery at day 4 and thereafter. Revasculization was not found, even in the patient operated one week after embolization. Massive bleeding (due presumably to the surgical procedure, suggesting recanalization) was noted in the tissue of a hemangioblastoma patient who underwent surgery 13 days after embolization, even though tumor excision was easy. In the patient subjected to the surgical procedure 694 days following embolization, the CT and MRI performed 2 months later, revealed contrast enhancement similar to that seen before the operation. Moreover, angiography, done after 5 months, demonstrated tumor stain as had been noted before embolization. The histopathologic examination of this case reveal the presence of extended necrotic lesions, a large number of macrophages that contained PVA particles, and destruction of the walls of the onceoccluded vessels. In addition, there were many blood-filled vessels that had achieved recanalization. These findings suggest that it is desirable to operate within 7 days after embolization, since recanalization occurs during this period, even though PVA particles remain unabsorbed for a long time.

Adult↗
PubMed1997

Low prevalence of factor V:Q506 in 41 patients with isolated pulmonary embolism.

In 70-80% of cases, pulmonary embolism is the consequence of lower extremity deep vein thrombosis. It has been demonstrated that the most common coagulation defect predisposing to venous thrombosis, resistance to activated protein C (APC), is not associated with an increased risk for pulmonary embolism, but the evidence was based on a functional assay to diagnose APC resistance and no information about concomitant deep vein thrombosis was provided. The aim of our study was to evaluate the prevalence of factor V:Q506, the gene mutation responsible for APC resistance, in patients with symptomatic non-fatal pulmonary embolism, whether or not associated with deep vein thrombosis. Patients with uncomplicated deep vein thrombosis and healthy controls were investigated as comparison groups. The overall prevalence of factor V:Q506 in 106 patients with pulmonary embolism was 12.3%, lower than that found in 106 patients with deep vein thrombosis (22.6%, OR 0.5, 95% CI 0.2-1.0) but significantly higher than that found in 212 healthy subjects taken as controls (2.8%, OR 4.8, 95% CI 1.8-13.0). In the 41 patients with isolated pulmonary embolism, i.e., without the presence of deep vein thrombosis, the prevalence was 4.9%, similar to that in controls (OR 1.8, 95% CI 0.3-9.6), while in the remaining 65 patients with pulmonary embolism associated with deep vein thrombosis the prevalence was significantly higher (16.9%, OR 5.5, 95% CI 2.0-15.8). In conclusion, the prevalence of factor V:Q506 is high in patients with pulmonary embolism associated with deep vein thrombosis, whereas in patients with isolated pulmonary embolism it is similar to that found in control subjects. This intriguing finding is of difficult interpretation and needs confirmation by further studies.

Adolescent↗
PubMed1997

Embolization of cerebral arteriovenous malformations with silk: histopathologic changes and hemorrhagic complications.

PURPOSE: To evaluate the safety of silk as an embolic agent for preoperative embolization of cerebral arteriovenous malformations (AVMs) by assessing the histopathologic changes and hemorrhagic complications associated with its use. METHODS: Histopathologic specimens, medical records, and radiologic records of 73 patients with AVMs embolized with silk (alone or in combination with other agents) were reviewed retrospectively. Forty-eight histologic specimens obtained at surgery were analyzed for inflammatory responses and compared with the time interval between embolization and surgery. Postembolization angiograms were assessed for vasculitis and CT scans were reviewed for evidence of hemorrhage after embolization. RESULTS: There was no angiographic evidence of vasculitis. Histologic evidence of vasculitis was absent or mild in 92% of cases and histologic evidence of perivascular inflammation was absent or mild in 73% of cases. The frequency of histologic changes associated with vasculitis, perivascular inflammation, and vessel necrosis varied with the time interval between embolization and AVM resection. Intracranial hemorrhage, as a direct complication of silk use, occurred in one patient. Another patient had subarachnoid hemorrhage 24 hours after embolization, caused by rupture of a posteroinferior cerebellar artery aneurysm. Intraventricular high-density material appeared on routine postembolization CT scans in two other patients who had intraventricular AVM extension. This high-density material was thought to be contrast extravasation from intrinsically leaky AVM nidus vessels and not frank hemorrhage. CONCLUSION: Embolization of AVMs with silk does not result in marked inflammation or increased hemorrhagic complications as compared with other agents.

Adolescent↗
PubMed1997

[Mid-term follow-up results of coil embolization for patent ductus arteriosus].

Mid-term follow-up results of coil embolization for patent ductus arteriosus (PDA) were evaluated in 19 patients aged from 2 years 9 months to 13 years (median: 5 years and 10 months) who underwent coil embolization for PDA. The minimum diameter of PDA ranged from 1.0 to 3.5 mm (mean 2.3 +/- 0.8 mm). Coil embolization was performed by the retrograde approach in 16 patients and the anterograde approach in 3, using a Gianturco coil in 11 and a Jackson detachable coil system in 8. Sixteen patients underwent single coil embolization and three patients received two coils simultaneously with detachable coil systems. Follow-up evaluation was performed with color flow mapping and pulsed Doppler echo to identify residual shunt or acquired left pulmonary artery stenosis after embolization at 1 day, 1 week, 1, 3, 6 and 12 months, and every 6 months thereafter. In two patients, a coil had migrated into the distal left pulmonary artery immediately after implantation, and could be safely retrieved. Minimum residual shunt was found in six patients (32%) on the day after the procedure. Spontaneous closure was noted in all patients within 6 months. Recanalization of completely occluded PDA was observed in one patient at 1 month after embolization. However, spontaneous closure of the residual shunt was found at 1 year and 6 months of follow-up. There was no evidence of acquired left pulmonary artery stenosis during the follow-up period (14.5 +/- 5.8 months). Coil embolization is an effective and safe therapy for PDA. Small residual shunt may be observed immediately after the coil embolization, but will close spontaneously during the follow-up. Recanalization occurred after complete coil occlusion, so careful follow-up with color flow mapping is mandatory.

Adolescent↗
PubMed1997

Pharmacologic modulation of pulmonary vascular permeability during air embolism.

Pulmonary air embolism induces the generation of vasoactive and cytotoxic substances leading to lung injury. In the present study we investigated, in isolated and perfused rat lungs, the involvement of arachidonic acid metabolites in the alterations of vascular pressure, lung water content, and the filtration coefficient (Kf). We also tested the effects of a beta-agonist, a calcium channel blocker, and a cyclo-oxygenase inhibitor on the hemodynamic and the permeability changes following pulmonary air embolism. The artificially ventilated rat lungs were removed en bloc and suspended in a humidified chamber at 37 degrees C. The salt and buffered perfusate contained 4% Ficoll as albumin substitute for osmotic balance. We introduced air bubbles through the pulmonary artery. Air embolism increased pulmonary arterial resistance and caused pulmonary hypertension. Lungs receiving air infusion contained 88.6 +/- 0.6% water, which was significantly greater than the lung water content in the control groups (81.9 +/- 0.4%). Air embolism increased Kf by 145 +/- 19% from the baseline value. Pretreatment with indomethacin, isoproterenol, or nifedipine significantly reduced post-air-embolism lung water content to 85.8 +/- 0.5%, 84.1 +/- 0.4%, and 86.5 +/- 04%, respectively, and reduced the Kf increase to 17 +/- 8%, 1 +/- 9%, and 72 +/- 8%, respectively. These interventions did not alter the hemodynamic responses, except for the isoproterenol infusion, which shortened the half-time (T1/2) for pressure recovery after ending air infusion compared to the group with air embolism alone. Our results showed that indomethacin prevented vascular permeability increase and reduced pulmonary edema, suggesting that the cyclo-oxygenase products partially mediate the lung injury following air embolism. Furthermore, isoproterenol and nifedipine prevented or reduced the permeability increase, suggesting that alterations of the intracellular cAMP and cytosolic Ca2+ level play an important role in the pathophysiology of pulmonary air embolism.

Animals↗