Effects of repeat bolus ethanol injections on cardiopulmonary hemodynamic changes during embolotherapy of arteriovenous malformations of the extremities

The Guidelines for Percutaneous Transhepatic Portal Vein Embolization: English Version

Preoperative portal vein embolization is a beneficial option to reduce the risk of postoperative liver failure by promoting the growth of the future liver remnant. In particular, a percutaneous transhepatic procedure (percutaneous transhepatic portal vein embolization) has been developed as a less-invasive approach. Although percutaneous transhepatic portal vein embolization is widely recognized as a safe procedure, various complications, including rare but fatal adverse events, have been reported. Currently, there are no prospective clinical trials regarding percutaneous transhepatic portal vein embolization procedures and no standard guidelines for the PTPE procedure in Japan. As a result, various methods and various embolic materials are used in each hospital according to each physician's policy. The purpose of these guidelines is to propose appropriate techniques at present and to identify issues that should be addressed in the future for safer and more reliable percutaneous transhepatic portal vein embolization techniques.

Double Microballoon-occluded Ethanol Embolization for Pelvic Arteriovenous Malformation: A Case Report

A 40-year-old man was incidentally found to have right-sided pelvic arteriovenous malformation (AVM) with an aneurysmal dominant outflow vein (DOV). The AVM had two main feeding arteries forming a cluster of fine vessels shunt to the DOV. As transvenous approach was impossible due to anatomical difficulty, transarterial ethanol embolization was performed under simultaneous double microballoon occlusion of the two feeding arteries in combination with protective coil embolization of the prostatic branches. Ethanol (13 mL) was intermittently injected from both microballoon catheters until the AV shunt was completely occluded. At 1-year follow-up, contrast-enhanced CT revealed shrinkage of the thrombosed DOV without any symptom. Our case demonstrated the usefulness of simultaneous double microballoon-occluded ethanol embolization for treating a localized pelvic AVM with a few feeding arteries.

Ethanol Embolotherapy for Cutaneous Erythema of High-Flow Vascular Malformations in the Head and Neck

BACKGROUND

Cutaneous erythema is one of the most common signs of arteriovenous malformations (AVMs) in the head and neck region, influencing aesthetic appearance. Surgical resection of AVMs may lead to cicatrization of the skin or aggravation of the lesion. Laser treatment, although effective in improving superficial vascular lesions, cannot prevent deep AVMs from further development.

OBJECTIVE

The authors propose an absolute ethanol embolization therapy that can effectively and safely eradicate the nidus with a favorable aesthetic outcome.

METHODS

The authors conducted a retrospective observational study of 14 AVM patients with distinct cutaneous erythema in the head and neck region undergoing embolotherapy in a single primary care center. Symptoms before and after treatment, complications, and degree of devascularization were recorded and assessed. Changes in cutaneous redness were evaluated using a previously reported quantitative measurement.

RESULTS

Complete symptomatic relief was observed in 5 patients, and major improvement was observed in 9 patients. The mean Δ a * value of the color change had a significant reduction of 6.50 ± 4.04, p < .001, indicating a remarkable remission of cutaneous erythema.

CONCLUSION

Ethanol embolization is an effective and safe treatment for head and neck AVMs with excellent aesthetic outcomes and might become a potential treatment method for other superficial vascular anomalies.

Head and Neck Arteriovenous Malformations: Clinical Manifestations and Endovascular Treatments

Arteriovenous malformations (AVMs) are vascular malformations that present high-flow direct communication between the arteries and veins, not involving the capillary beds. They can be progressive and lead to various manifestations, including abnormal skin or mucosal findings, ischemia, hemorrhage, and high-output heart failure in severe cases. AVMs often involve the head and neck region. Head and neck AVMs can present region-specific clinical manifestations, angioarchitecture, and complications, especially in cosmetic appearance and ingestion, respiratory, and neuronal functions. Therefore, when planning endovascular treatment of head and neck AVMs, physicians should consider not only the treatment strategy but also the preservation of the cosmetic appearance and critical functions. Knowledge of the functional vascular anatomy as well as treatment techniques should facilitate a successful management. This review summarizes AVMs' clinical manifestations, imaging findings, treatment strategy, and complications.

Contemporary management of extracranial vascular malformations

Vascular malformations are congenital vascular anomalies that originate because of disorganized angiogenesis, most commonly from spontaneous somatic genetic mutations. The modern management of vascular malformations requires a multidisciplinary team that offers patients the gamut of medical, surgical, and percutaneous treatment options with supportive care. This manuscript discusses the standard and contemporary management strategies surrounding extracranial vascular malformations and overgrowth syndromes.

Endovascular and Percutaneous Embolotherapy for the Body and Extremity Arteriovenous Malformations

Arteriovenous malformations (AVMs) consist of abnormal communications between the arteries and veins. They can involve any part of the body and extremity and grow in proportion to age and in response to hormonal influence or trauma. When symptoms progress from Schöbinger clinical stage II to III, transcatheter and/or direct puncture embolization are less-invasive and repeatable options for symptom palliation. The goal of embolization is to obliterate the AV shunt, and the choice of lesion access and embolic agents is based on the individual anatomy and flow. Embolization can be technically challenging due to complex vascular anatomy and morbidity risks. Therefore, a multidisciplinary management is essential for the diagnosis and therapeutic intervention of AVMs.

Ethanol Embolization of Chest Wall Arteriovenous Malformations: Four-Year Findings

OBJECTIVES

To summarize the clinical characteristics and investigate the efficacy of ethanol embolotherapy in the treatment of chest well arteriovenous malformation (AVM). Treatment-associated complications were also explored.

MATERIALS AND METHODS

Between March 2017 and August 2021, 32 consecutive patients (mean age, 23.7 years; age range, 5-54 years) who underwent ethanol embolotherapy for chest well AVMs under general anesthesia were included in this study. Embolization was performed through a direct puncture, transarterial catheterization, or a combination of the 2 procedures. The mean follow-up duration after the last treatment was 18.0 months (range, 3-42 months). The degree of devascularization on follow-up (assessed using angiography or computed tomography), and the clinical signs and symptoms of AVMs were evaluated as the therapeutic outcomes. The major and minor complications associated with the procedures were recorded.

RESULTS

A total of 103 embolization procedures (mean, 3.2; range, 2-7) comprising 101 ethanol embolization and 2 coil embolizations were performed on 32 patients with chest wall AVMs. The AVM nidus was accessed through the transarterial approach alone in 4 patients, by direct puncture in 11, and a combined procedure in 17 patients. Overall, more than 80% of the procedures were performed using the combined approach. Complete AVM devascularization was achieved in 12 (37.5%) patients. Moreover, 76% to 99% AVM was achieved in 18 patients (56.3%), and 50% to 75% in 2 patients (6.3%). Bleeding, pain, heart failure, and cosmetic deformities were the indications for treatment. For 3 patients (3/32, 9.4%) who had bleeding, the treatment stopped the hemorrhage. Complete pain relief was reported in 8 patients (8/32, 25.0%), whereas complete relief from congestive heart failure post-embolization was observed in 5 of the 6 patients with congestive heart failure (5/6, 83.3%). Complete correction of cosmesis deformities after embolization was achieved in 10 patients (10/32, 31.3%). Two patients who underwent surgery to correct persistent deformity after embolization only showed insignificant improvement. In addition, 6 (18.8%) patients developed 13 complications including blister, necrosis, hemothorax, transient hemoglobinuria, and transient pulmonary artery hypertension.

CONCLUSIONS

Ethanol embolotherapy is a safe and effective procedure for chest well AVMs. Surgery is required for some patients with residual cosmesis deformity.

CLINICAL IMPACT

Currently, there is no standard treatment for chest well AVMs due to their rarity and high heterogeneity. The present study shows that thanol embolotherapy is a safe and clinically effective treatment procedure for the chest well AVMs. Transarterial embolization in combination with direct puncture embolization can reach the AVM nidus. Ethanol embolotherapy can achieve complete obliteration of the AVM nidus in the majority of patients. Surgery may still be needed to correct cosmetic deformity after embolization. The present study provides valuable evidence to inform clinical decision-making.

Inhibition of angiotensin II type 1 receptor partially prevents acute elevation of pulmonary arterial pressure induced by endovascular ethanol injection

This study aimed to examine whether the administration of losartan can prevent acute elevation of pulmonary arterial pressure (AEPAP) induced by endovascular ethanol injection and to assess its related mechanisms. Male swine were selected and performed with absolute ethanol endovascular injection. Saline was used as the negative control. Losartan was administered preoperatively. Pulmonary arterial pressure (PAP), femoral arterial pressure (FAP) and heart rate (HR) were monitored during operations. Venous plasma and pulmonary artery (PA) tissue were harvested for analyses. Protein level was detected by Western blotting and ELISA, whereas qRT-PCR was used in mRNA detection. H & E staining and immunohistochemistry were conducted to evaluate histopathology. Ethanol injection elevated PAP in swine. The concentration of RAS ligands was elevated in plasma (all P < 0.0001) but not in PA. The level of oxidative stress increased in both plasma and PA. MRNA level of AT1R (P < 0.01, 95% CI: 0.251-1.006), not AT2R increased in PA. Losartan failed to inhibit AEPAP after all sessions of ethanol injection, and partially reversed the ethanol-induced PA remodeling. The P38 MAPK was activated after ethanol injection and could be inhibited by losartan (P < 0.01, 95% CI: -0.391 to -0.164). Ethanol also promoted the translocation of the P40-PHOX/P47-PHOX/P67-PHOX complex and the activation of NOX, which was independent from RAS. Endovascular ethanol injection can induce AEPAP mainly by activating RAS and P38 MAPK signaling. Losartan can partially prevent AEPAP and vascular remodeling owing to the promotion of NOX activity by ethanol. Mechanism diagram of endovascular ethanol injection-induced acute elevation of pulmonary arterial pressure (AEPAP) partially prevented by losartan. RAS: Renin-angiotensin system; AGT: angiotensinogen; Ang I: angiotensin I; ACE: angiotensin I converting enzyme; Ang II: angiotensin II. AT1R: angiotensin II type 1 receptor. NOX2: NADPH oxidase 2. PA: pulmonary artery.

Treatment outcomes and effects of ethanol sclerotherapy on systemic coagulation profile of patients with venous malformation

OBJECTIVE

Venous malformations (VMs) and sclerotherapy may disrupt the normal systemic coagulation profile in individuals. This study investigated a correlation between the clinical efficacy of sclerotherapy in the treatment of VMs and the changes in coagulation indexes to provide data that will inform future application of this therapy.

METHODS

From September 2019 to September 2020, 61 patients were enrolled in this study to receive sclerotherapy with absolute alcohol. The clinical outcomes and the coagulation profile were assessed.

RESULTS

Sclerotherapy induced increasing in fibrin (original) degradation products (FDP), D-dimer (D-D). The changes in FDP and D-D level pre- and post-treatment were positively correlated with treatment outcomes. Moreover, repeated treatment with absolute alcohol may restore normal levels of FDP and D-D.

CONCLUSIONS

Upregulation of FDP and D-D levels after sclerotherapy results in good therapeutic outcomes. Therefore, monitoring changes in FDP and D-D levels in patients with VMs undergoing sclerotherapy may reflect the effects of sclerotherapy.

Giant parapharyngeal high-flow arteriovenous malformation causing airway compromise: emergency embolo-sclerotherapy via an endovascular-only approach

Head and neck arteriovenous malformations are the commonest extracranial vascular malformations but demonstrate a unique challenge in the limited available surgical options secondary to their intimate association to vital structures. We present a case of middle-aged female patient who presented with threatened upper-airway obstruction and bleeding secondary to a slowly enlarging parapharyngeal arteriovenous malformations. She was treated with an endovascular-only approach with the proximal arteriole branches selectively undergoing embolo-sclerotherapy with an optimal radiological and clinical outcome. We also demonstrate the utility of elective tracheostomy prior to intervention.

Management of Venous Malformations

Venous malformations (VMs) are slow-flow, congenital vascular anomalies that are a result of vascular dysgenesis. Clinical presentation and morbidity depend on size, location, and association with other syndromes. VMs are the most common symptomatic vascular anomaly referred for intervention, usually due to thrombosis, swelling, mass effect, functional compromise, or cosmetic concerns. Treatment for larger lesions can be challenging and a multidisciplinary approach involving medical, interventional, and surgical input is critical for comprehensive care. This article will assist the interventional radiologist in patient assessment and will discuss current techniques for treatment, means to minimize adverse events, and expected outcomes.

Therapeutic outcomes of embolotherapy of extremity bone intraosseous arteriovenous malformation with ethanol, coils, and n-butyl cyanoacrylate

OBJECTIVE

We evaluated the therapeutic outcomes of embolotherapy for bone arteriovenous malformations (AVMs) affecting the extremities using ethanol, coils, and n-butyl cyanoacrylate (NBCA).

METHODS

We reviewed the data from 36 patients (18 males, 18 females; mean age 25 years; age range, 1-64 years) with bone AVMs affecting their extremities who had undergone embolotherapy using ethanol, coils, and NBCA from December 1996 to July 2019. Of the 36 patients, 19 had had pure bone AVMs and 17 mixed bone and soft tissue (MBS) AVMs. Embolotherapy was performed using direct puncture or a transvenous or an intra-arterial approach (range, 1-18 procedures; mean, 5 procedures). During the 178 embolotherapy procedures, ethanol was used in all 36 patients, except for 1. Coils were used in 14 patients, and NBCA and a lipiodol mixture in 9 patients. The therapeutic outcomes were evaluated by the clinical symptom response and the degree of devascularization on follow-up angiography or computed tomography. The major and minor complications were also evaluated.

RESULTS

The clinical success (cure or markedly improvement) rate of embolotherapy for pure bone AVMs was significantly better than that for the MBS AVMs (88% vs 18%; P < .001). The complete devascularization rate of the bone AVM component of the MBS AVMs was 71%; however, the cure rate of the MBS AVMs was 0% owing to the remaining soft tissue AVMs. Of the 36 patients, 12 experienced complications, including 11 minor (2 skin bullae formation and 10 transient peripheral nerve injury) and 1 major (longstanding nerve palsy).

CONCLUSIONS

Embolotherapy for bone AVMs affecting the extremities using ethanol, coils, and an NBCA mixture is effective and safe for the resolution or improvement of symptoms, especially in those with pure bone AVMs.

Treatment Outcomes of Embolization for Peripheral Arteriovenous Malformations

PURPOSE

To evaluate treatment outcomes of embolization for peripheral arteriovenous malformations (AVMs) in a tertiary referral center where ethanol is the primary agent of choice.

METHODS

A retrospective study was performed of 93 patients (median age, 31 years; range, 2-66 years) with peripheral AVMs treated with embolization (n = 442; median, 2 per patient; range, 1-82) between January 2010 and July 2016. Ethanol was used in most cases (n = 428; 97%). AVMs were classified as type I (n = 3), type II (n = 57), type IIIa (n = 5), type IIIb (n = 15), and type IV (n = 13) according to the Yakes classification system. Effectiveness of embolization was based on AVM devascularization on angiography: 100% (total), 90%-99% (near-total), 70%-90% (substantial), 30%-70% (partial), and 0%-30% (failure). Complications were graded according to the Society of Interventional Radiology classification.

RESULTS

In 69% of patients, 70%-100% devascularization was achieved. Total and near-total occlusion of the nidus were more often achieved in AVMs of types I and IIIa (both 100%) than in AVMs of types II, IIIb, and IV (56%, 67%, and 39%, respectively; P = .019). A total of 109 complications were identified: 101 minor (22.9%) and 8 major (1.8%). Major complications included wounds (n = 5), false aneurysm (n = 1), finger contracture (n = 1), and severe pain (n = 1) requiring therapy. The patient complication risk was significantly affected by the number of procedures (relative risk = 2.0; P < .001). Age, AVM location, and angioarchitecture type did not significantly affect complication risk.

CONCLUSIONS

AVM embolization resulted in 70%-100% devascularization in 69% of patients, with few major complications. This study indicates that the type of AVM angioarchitecture affects the number of procedures needed and the achievability of AVM devascularization.

Selective Arterial Embolizations of Renal Angiomyolipomas Using 96% Ethanol: A Case Series of 5 Patients

Angiomyolipomas are rare benign tumors of the kidneys, with a risk of spontaneous hemorrhage including severe retroperitoneal bleedings. In this study, we report clinical outcomes of 5 patients who underwent 8 embolization sessions using 96% ethanol, as there is scarce data using this embolic agent for this indication. The primary angiographic success could be achieved in all but 1 lesion, which was not accessible due to vasospasm of the supplying vessel. Therapeutic success could be demonstrated in all treated cases for which follow-up imaging was available (n = 3). In 1 complex patient, a mildly reduced renal function, as well as a new onset of arterial hypertension was detected after treatment. Nontarget embolization of vital kidney tissue was demonstrated in another patient; it remained asymptomatic. Embolization therapy using 96% ethanol is an optional method to treat renal angiomyolipomas.

Subclassification and Treatment Results of Ethanol Embolotherapy of Type II Arteriovenous Malformations of the Extremity and Body

PURPOSE

To evaluate the safety and efficacy of ethanol and coil embolization of type II arteriovenous malformation (AVM) according to a new subtype classification.

MATERIALS AND METHODS

Eighty-four type II AVMs in the body or extremity of 79 patients who underwent AVM treatment from 1996 to 2017 were retrospectively subclassified according to the angiographic morphology of the draining vein as type IIa (arterioles shunt to focal segment of single draining vein), type IIb (arterioles shunt to venous sac with multiple draining veins), and type IIc (arterioles shunt along long segment of draining vein). Coil and ethanol embolization of the focal or long segment of the draining vein or the venous sac was performed with direct puncture or transvenous approach according to subtype. Treatment outcomes, number of treatment sessions, and complications were analyzed.

RESULTS

AVM cure (ie, complete embolization) rates were 95%, 76%, and 65% in types IIa, IIb, and IIc AVMs, respectively. The cure rate of type IIa AVMs was significantly better than that of type IIc AVMs (P = .015). Median numbers of treatment sessions were 1 in types IIa and IIb AVMs and 2.5 in type IIc AVMs, with a significant difference between type IIc and the other 2 types (P < .05). Minor complications occurred in 20% of patents and major complications occurred in 7%.

CONCLUSIONS

The cure rate of type IIa AVMs was significantly better than that of type IIc AVMs, which also required significantly more treatment sessions than the other 2 types.

Sclerotherapy for intramuscular vascular malformations: A single-center experience

BACKGROUND

Vascular malformations isolated to skeletal muscles are rare and often debilitating due to pain and very challenging to treat. Multi-modal management options include compression garments, medical therapy, sclerotherapy, and surgical resection.

METHODS

A retrospective review of patients who underwent sclerotherapy for intramuscular venous malformations (IVM) between 2008 and 2016 was performed. Demographics, indications, and clinical follow-up were analyzed.

RESULTS

Twenty patients underwent sclerotherapy for IVM. Six males and 14 females underwent 58 procedures. All patients presented with pain and were treated initially with compression garments. Median age at first treatment was 13years (+/- 5.06years). Initial protocol consisted of 2 sclerotherapy procedures with sodium tetradecyl sulfate (STS) within a 2-3month interval. Median volume of the lesion was 40cm³ (+/- 28.7), mostly located in the lower extremities (15/20). Median number of treatments was 2 (+/- 1.95). Treatment prior to puberty resulted in a median symptom-free time of 4years (+/- 2.18), while after puberty resulted in a symptom-free time of 2years (+/- 2.28). Two patients had an underlying coagulopathy and were admitted for observation and peri-procedural Lovenox. No procedure related complications were noted with a median follow-up of 4years (+/- 2.27).

CONCLUSION

IVMs are rare but can be incapacitating secondary to pain. Sclerotherapy is a useful minimally invasive procedure generally requiring at least two consecutive treatments. Treatment of patients prior to puberty appears to provide a more durable result, and surgical resection may be avoided.

TYPE OF STUDY

retrospective.

LEVEL OF EVIDENCE

IV.

Complications After Treatment of Head and Neck Venous Malformations With Sodium Tetradecyl Sulfate Foam

PURPOSE

The aim of this study was to evaluate complications in patients with head and neck venous malformations (VMs) treated with foam sclerotherapy using sodium tetradecyl sulfate (STS).

METHODS

The authors retrospectively evaluated the complications, pain. and degree of satisfaction in 69 consecutive patients affected by cervicofacial VM managed with STS using the Tessari method in a single institution.

RESULTS

The average number of procedures for each patient was 2.1. The most frequent complication was blistering. We observed 1 patient of temporary weakness of a facial nerve branch, 1 paradoxical embolism, and 1 orbital compartment syndrome.The average pain score was 0 (no pain at all) (51.5%). There was no statistically significant correlation between patient satisfaction and the presence of complications or the degree of pain.

CONCLUSIONS

Sclerotherapy with STS is an effective treatment that yields to very high patient satisfaction. This procedure has an overall low complication rate and is usually effective within a few sessions. However, severe complications may occur; these must be pointed out in the informed consent and the surgeon must be aware of and ready to quickly treat them to prevent long-term sequelae.

New Treatment Approaches to Arteriovenous Malformations

Arteriovenous malformations (AVMs) are high-flow vascular anomalies that have demonstrated a very high recurrence rate after endovascular treatment, surgical treatment, or a combination of both. Surgical treatments have shown good response when they are small and well localized but a poor response when diffuse. A better understanding of the nature of the lesion has led to a better response rate and a safer treatment for these patients. This has been accomplished through a detailed understanding of the angioarchitecture of the lesion, enabling a tailored approach in reaching and targeting the nidus of the AVM with different liquid embolic agents, more specifically ethanol. Flow reduction techniques help in exposing the nidus to sclerosant agents. A clinical classification, the Schobinger classification, will help determine the appropriate time to start or to pursue therapy.

Venous malformations: clinical diagnosis and treatment

Venous malformation (VM) is the most common type of congenital vascular malformation (CVM). They are present at birth and are often symptomatic, causing morbidity and pain. VMs can be challenging to diagnose and are often confused with hemangioma in terminology as well as with imaging. An accurate clinical history and cross-sectional imaging are critical for diagnosis and for devising management. This manuscript will review imaging approaches to diagnosing VMs and current treatment strategies.

Renal Arteriovenous Shunts: Clinical Features, Imaging Appearance, and Transcatheter Embolization Based on Angioarchitecture

Renal arteriovenous (AV) shunt, a rare pathologic condition, is divided into two categories, traumatic and nontraumatic, and can cause massive hematuria, retroperitoneal hemorrhage, pain, and high-output heart failure. Although transcatheter embolization is a less-invasive and effective treatment option, it has a potential risk of complications, including renal infarction and pulmonary embolism, and a potential risk of recanalization. The successful embolization of renal AV shunt requires a complete occlusion of the shunted vessel while preventing the migration of embolic materials and preserving normal renal arterial branches, which depends on the selection of adequate techniques and embolic materials for individual cases, based on the etiology and imaging angioarchitecture of the renal AV shunts. A classification of AV malformations in the extremities and body trunk could precisely correspond with the angioarchitecture of the nontraumatic renal AV shunts. The selection of techniques and choice of adequate embolic materials such as coils, vascular plugs, and liquid materials are determined on the basis of cause (eg, traumatic vs nontraumatic), the classification, and some other aspects of the angioarchitecture of renal AV shunts, including the flow and size of the fistulas, multiplicity of the feeders, and endovascular accessibility to the target lesions. Computed tomographic angiography and selective digital subtraction angiography can provide precise information about the angioarchitecture of renal AV shunts before treatment. Color Doppler ultrasonography and time-resolved three-dimensional contrast-enhanced magnetic resonance angiography represent useful tools for screening and follow-up examinations of renal AV shunts after embolization. In this article, the classifications, imaging features, and an endovascular treatment strategy based on the angioarchitecture of renal AV shunts are described.

Renal artery embolization-indications, technical approaches and outcomes

Owing to improvements in catheters and embolic agents, renal artery embolization (RAE) is increasingly used to treat nephrological and urological disease. RAE has become a useful adjunct to medical resuscitation in severe penetrating, iatrogenic or blunt renal traumatisms with active bleeding, and might avoid surgical intervention, particularly among patients that are haemodynamically stable. The role of RAE in pre-operative or palliative management of advanced malignant renal tumours remains debated; however, RAE is recommended as a first-line therapy for bleeding angiomyolipomas and can be used as a preventative treatment for angiomyolipomas at risk of bleeding. RAE represents an alternative to nephrectomy in various medical conditions, including severe uncontrolled hypertension among patients with end-stage renal disease, renal graft intolerance syndrome or autosomal dominant polycystic kidney disease. RAE is increasingly used to treat renal artery aneurysms or symptomatic renal arteriovenous malformations, with a low complication rate as compared with surgical alternatives. This Review highlights the potential use of RAE as an adjunct in the management of renal disease. We first compare and contrast the technical approaches of RAE associated with the various available embolization agents and then discuss the complications associated with RAE and alternative procedures.

Pulmonary arterial hypertension secondary to ethanol sclerotherapy for renal artery embolization

Pulmonary arterial hypertension (PAH) has been reported as a major complication to consider and promptly manage in the use of ethanol sclerotherapy. Most of the available data on the development of PAH is derived from the use of ethanol for embolization of arteriovenous malformation, but it has been rarely reported in its other fields of application. We describe a case of outpatient renal artery embolization using ethanol, in which respiratory failure develops secondary to PAH despite adhering to safe practice protocols. We highlight the importance of pulmonary arterial pressure monitoring and the treatment steps to follow in order to avoid irreversible fatal outcomes.

Vascular anomalies: classification, imaging characteristics and implications for interventional radiology treatment approaches

The term vascular anomaly represents a broad spectrum of vascular pathology, including proliferating vascular tumours and vascular malformations. While the treatment of most vascular anomalies is multifactorial, interventional radiology procedures, including embolic therapy, sclerotherapy and laser coagulation among others, are playing an increasingly important role in vascular anomaly management. This review discusses the diagnosis and treatment of common vascular malformations, with emphasis on the technique, efficacy and complications of different interventional radiology procedures.

Experimental intraperitoneal injection of alcohol in rats: Peritoneal findings and histopathology

PURPOSE

This study aimed to evaluate the macroscopic and microscopic peritoneal findings after intraperitoneal injection of alcohol in rats.

METHODS

From January to February 2012, 20 male rats were used in this study: 15 rats received intraperitoneal injection of 0.1 mL 99.9% alcohol (group 1: experiment group) and 5 rats received intraperitoneal injection of 0.1 mL normal saline (group 2: control group). Animals from each group were sacrificed the day after alcohol injection and each week thereafter. Macroscopic and microscopic examinations of the peritonea and abdominal cavity were performed in each rat.

RESULTS

There was no significant peritoneal abnormality on macroscopic view, except for a whitish-colored parietal peritoneum around the injection site in 3 animals from group 1. In all but 1 of the animals in group 1, mild to moderate peritoneal inflammation or fibrosis was observed 1 and 2 weeks after alcohol injection. However, the peritoneal abnormality of alcohol injection had dissipated by week 3. Peritoneal abnormalities were not observed in group 2.

CONCLUSION

An intraperitoneal injection of alcohol in rats caused peritoneal inflammation or fibrosis during the first 2 weeks. However, these peritoneal abnormalities were short-lived and had completely disappeared after 3 weeks.

Acute cor pulmonale and right heat failure complicating ethanol ablative therapy: anesthetic and radiologic considerations and management

Ethanol is an effective ablative agent used for the treatment of certain solid organ tumors and vascular malformations (VMs). The egress of ethanol beyond the target tissue can be associated with significant changes to the cardiopulmonary system that can lead to cardiac arrest. This article reviews the contemporary role of ethanol in tumor and VM treatment and discusses the physiological mechanisms of acute pulmonary hypertension and cardiovascular collapse. The importance of periprocedural recognition of the hemodynamic changes that can occur with the use of ethanol and the treatment of this condition are discussed.

Ethanol threshold doses for systemic complications during sclerotherapy of superficial venous malformations: a retrospective study

INTRODUCTION

Ethanol has been used for many years for superficial venous malformations (VM) sclerotherapy. Although ethanol is well-tolerated in most of the cases, systemic side effects have been reported in some patients, including cardiac collapse and death. Systemic toxic side effects have been suspected to be proportional to the ratio of ethanol dose divided by the patient's body weight (dose/weight ratio in millilitre per kilogram). No extensive study has yet been conducted to determine the toxic threshold, and no consensus exists on this point.

METHODS

We retrospectively studied the systemic effects of ethanol sclerotherapy in a consecutive series of 71 patients with VM.

RESULTS

Seventy-one consecutive patients with VMs were treated by ethanol sclerotherapy and 162 procedures were performed. The only factor significantly associated with a systemic adverse event was the ethanol dose/weight ratio per intervention. The ethanol dose/weight ratio superior to 0.24 ml/kg was predictive of systemic toxic effects, suggesting a limit dose for ethanol sclerotherapy of VM. Systematic complications were not related to repetitive sclerotherapy sessions.

CONCLUSION

Based on our findings, a maximal ethanol dose/weight ratio of 0.2 ml/kg could be considered as acceptable in VM treatment indications.

Cardiovascular effects and predictability of cardiovascular collapse after repeated intravenous bolus injections of absolute ethanol in anesthetized pigs

PURPOSE

To evaluate the effects of repeated intravenous bolus injections of absolute ethanol on cardiopulmonary hemodynamic changes and to investigate the predictability of ethanol-induced cardiovascular collapse in anesthetized pigs.

MATERIALS AND METHODS

Twenty pigs aged 3-6 months and weighing 28-38 kg were enrolled in the study. Absolute ethanol (0.1 mL/kg of body weight) was repeatedly injected through the inferior vena cava central to the renal vein at 10-minute intervals up to a total volume of 1.0 mL/kg. The subjects were divided into a cardiovascular collapse group and a no-collapse group according to the development or absence of cardiac collapse.

RESULTS

Among the 20 pigs, 12 died before the final injection. Hemodynamic parameters measured immediately before the injection of absolute ethanol did not differ between the cardiovascular collapse group and the no-collapse group except that among animals with cardiovascular collapse, the injection immediately before the one causing cardiovascular collapse resulted in significant increases in the following hemodynamic parameters: mean pulmonary arterial pressure (P < .01), pulmonary vascular resistance (P = .04), and right ventricular end-diastolic volume (P = .02). No such increases were observed in the no-collapse group.

CONCLUSIONS

Hemodynamic profiles in pigs obtained immediately before intravenous injection of absolute ethanol did not predict the subsequent occurrence of cardiovascular collapse except after the injection immediately preceding the one resulting in cardiovascular collapse. In this animal model, significant increases in select hemodynamic parameters occurred after the injection immediately preceding the one resulting in cardiovascular collapse.