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Vascular malformations are extremely challenging lesions. The clinical presentations of these congenital abnormalities are protean and range from asymptomatic birthmarks to life-threatening congestive heart failure and exsanguinating hemorrhage. These abnormalities are rare; most clinicians see only a few in a lifetime of practice. Thus, patients afflicted with these disorders often seek help from many different physicians and undergo repetitive examinations, misdiagnosis, and frequent failed attempts at “definitive” therapy that lead to exacerbation of symptoms, lesion recurrences, and disability.

Pediatric deep and cutaneous vascular lesions (hemangiomas) and vascular malformations, having been confused by many clinicians for decades, have been finally classified accurately by Mulliken, Glowacki, and coworkers, after denovo research into endothelial cell characteristics, numbers of mast cells present, and endothelial cell in vitro characteristics [1–6]. Most pediatric hemangiomas are not present at birth, clinically manifest within the first month of life, and exhibit a rapid growth phase in the first year of life. More than 90% of pediatric hemangiomas spontaneously regress to near-complete resolution by 5–7 years of age. Hemangiomas occur with a reported incidence of 1–2.6% [1, 6, 7]. Hemangiomas in the proliferative phase are characterized by rapid growth, significant endothelial cell hyperplasia forming syncytial masses, thickened endothelial basement membrane, ready incorporation of tritiated thymidine into the endothelial cells, and the presence of large numbers of mast cells [1–3].

The world’s literature certainly verifies the extreme challenges in the diagnosis and treatment of AVMs. The purpose of this chapter is to present a new Yakes AVM Classification System that has proven therapeutic implications to effectively treat complex AVMs in any anatomical area. By employing the Yakes AVM Classification System, a physician is now able to accurately classify AVMs and determine specific endovascular treatment strategies to consistently treat AVMs, and patients can enjoy long-term excellent outcomes. Defining the angioarchitecture of the high-flow AVM determines accurately the endovascular management strategy to best permanently ablate the AVM requiring treatment.

Arteriovenous malformation (AVM) is a type of congenital vascular malformations (CVM) that result from birth defects involving the vessels of both arterial and venous origins, resulting in direct communications between the different size vessels or a meshwork of primitive reticular networks of dysplastic minute vessels which have failed to mature to become “capillary” vessels termed “nidus.” As described in previous chapter, development of AVM attributes to an embryonal defect in the earlier stage of the angiogenesis than other forms of CVM. Therefore, the components of AVMs are more primitive than other types of CVM. In other words, it means AVM has higher potential to change after birth during growth of the patients. These lesions are defined by shunting of high-velocity, low-resistance flow from the arterial vasculature into the venous system in a variety of fistulous conditions.

Vascular anomalies constitute some of the most difficult diagnostic and therapeutic enigmas that can be encountered in the practice of medicine. The clinical presentations are extremely protean and can range from an asymptomatic birthmark to fulminant, life-threatening congestive heart failure. Attributing any of these extremely varied symptoms that a patient may present with to a vascular malformation can be challenging to the most experienced clinician. Compounding this problem is the extreme rarity of these vascular lesions. If a clinician sees one patient every few years, it is extremely difficult to gain a learning curve to diagnose and optimally treat them. Typically, these patients bounce from clinician to clinician only to experience disappointing outcomes, complications, and recurrence or worsening of their presenting symptoms. Vascular malformations are truly an “orphan” disease in the medical world.

Vascular anomalies constitute some of the most difficult diagnostic and therapeutic enigmas that can be encountered in the practice of medicine, particularly in the complex anatomy of the head and neck region. Daunting functional anatomy and gross disfigurement are significant issues in the management of such anomalies in the head and neck area. Clinical presentations can be extremely varied, and attributing these symptoms that a patient may present with to a vascular malformation can be challenging to the most experienced physician. In the head and neck anatomy, the diagnosis can be somewhat easier as opposed to diagnoses in other areas of the body.

Classifications of high-flow arteriovenous malformations (AVM5) have been published in the neurovascular literature and in the peripheral vascular literature. These two classification systems are essentially the same in their angioarchitecture analysis. We propose a new Yakes AVM classification system that includes all AVM angioarchitecture types and those that have not been previously reported in the world’s literature. This all-encompassing AVM classification system also recommends endovascular treatment strategies that are curative in that specific AVM classification type. Thus, by analyzing the angioarchitecture of the AVM, the practicing physician can then be guided to specific treatment strategies to permanently treat that AVM type. We describe AVMs as Yakes Type I, Yakes Type II, Yakes Type llla, Yakes Type IlIb, and Yakes Type IV.

Peripheral arteriovenous malformations (AVM) remain most challenging among various congenital vascular malformations to be treated. Here we present three illustrative patients with Yakes type IIIb and type IV AVM at the plantar aspect of the foot who were successfully treated by minimally invasive embolization. The value of the Yakes AVM classification system to guide the therapeutic decision making by directing specific therapeutic procedures to specific AVM types defined by their angioarchitecture is demonstrated. Direct percutaneous AVM puncture with coiling of aneurysmal outflow vein and subsequent ethanol embolization is shown. Finally, the report illustrates that several AVM types can coexist.

A 56-year-old man was admitted to the hospital because of lower gastrointestinal bleeding manifested by black, tarry stool. Medical history and physical examination were noncontributory; he had no history of alcohol or drug abuse. Laboratory findings included a hematocrit of 26.2% and a platelet count of 166,000/ L. International Normalized Ratio and aspartate aminotransferase, alanine aminotransferase, albumin, and bilirubin levels were normal. Serologic examinations were negative for hepatitis. Large esophageal varices were seen on upper endoscopy. A transvenous liver biopsy was performed, which demonstrated nodular regenerative hyperplasia. Arterial portography, hepatic venography, cavography, and venous pressures were normal. The corrected sinusoidal pressure (wedged minus free hepatic venous pressure) was 11 mm Hg. However, subsequent direct portography performed via a transjugular approach demonstrated a portal vein–to–hepatic vein gradient of 30 mm Hg. A surgical shunt was performed to manage the gastrointestinal bleeding. Intraoperatively, the inferior mesenteric vein was noted to be quite large and to interfere with mobilization of the left renal vein; the inferior mesenteric vein was divided and the limb in communication with the splenic vein was sewn to the left renal vein. Postoperative magnetic resonance (MR) angiography was performed (Fig 1) because the shunt could not be visualized on surveillance ultrasonography. Because of the findings, inferior mesenteric arteriography (Fig 2) was performed.

To assess retrospectively the interim results and the complications of ethanol embolization treatment of arteriovenous malformations (AVMs).Institutional review board approval was obtained for a retrospective review of patient medical and imaging records. Informed consent was not required by the institutional review board. Written consent for the procedure was obtained from all patients after a discussion about the advantages and risks of the procedure. After a general anesthetic was administered, 40 patients (16 male, 24 female; age range, 9-53 years) with inoperable AVMs in the body and extremities underwent staged ethanol embolizations (range, 1-24; median, 3). Pulmonary artery pressure and arterial blood pressure were monitored as ethanol was injected. Ethanol embolizations (50%-100% ethanol mixed with nonionic contrast material) were performed by using transcatheter and/or direct puncture techniques. Ten patients underwent additional coil deployment during ethanol embolization. Clinical follow-up (range, 2-48 months; mean, 14.6 months; median, 12 months) was performed in all patients, and results from imaging follow-up (range, 0-48 months; mean, 8.4 months; median, 6 months) were available from the last treatment session in 28 patients. Therapeutic outcomes were established by evaluating the clinical outcome of symptoms and signs, as well as the degree of devascularization at follow-up angiography.One hundred seventy-five ethanol embolizations were performed in 40 patients. Sixteen (40%) of 40 patients were cured, 11 (28%) had partial remission, seven (18%) had no remission, and one (2%) experienced aggravation. Treatment failed in five patients (12%). Ethanol embolization was considered effective (cure, 16 patients; partial remission, 11 patients) in 27 patients (68%). Eleven patients will need further treatment sessions for residual AVMs. Twenty-one patients (52%) experienced complications. Twenty-seven minor complications (skin and transient peripheral nerve injuries) (27 [15%] of 175 procedures) occurred in 18 (45%) of 40 patients. All minor complications were healed with wound dressing and observation. Five major complications (five [3%] of 175 procedures) occurred in five (12%) of 40 patients, and four patients recovered completely.Ethanol embolization has the potential for cure in the management of AVMs of the body and extremities but with acceptable risk of minor and major complications.

Objective The goal was to determine the safety and efficacy of absolute ethyl alcohol treatment in the management of intra-axial brain arteriovenous malformations (AVMs). Methods Seventeen patients (eight female and nine male patients; mean age, 41 yr) underwent ethanol endovascular therapy for treatment of their brain AVMs. Superselective amytal testing preceded all procedures. Neuroleptic intravenous anesthesia was used for 16 patients, and general anesthesia was used for 1 patient. Follow-up monitoring consisted of clinical evaluations, magnetic resonance imaging, and arteriography. Results In follow-up evaluations (mean follow-up period, 13 mo) after embolization of brain AVMs, neither vascular recanalization nor the neovascular recruitment phenomenon was observed in any patient. Progressive AVM thrombosis at arteriographic follow-up evaluation was a constant feature. Seven patients were cured of their AVMs with ethanol endovascular therapy alone. Three patients were cured of their lesions with ethanol embolization plus surgical resection. One patient was cured of his lesion with ethanol embolization and radiation therapy of the residual nidus. Three patients underwent only partial therapy, with significant improvement in symptoms. Three patients are currently undergoing ethanol endovascular therapy. Complications occurred with 8 of 17 patients, most of which were transient. Two patients died because of late subarachnoid hemorrhages, one patient 4 months and one patient 14 months after partial therapy. Conclusion Progressive and permanent AVM occlusion is a common finding in arteriographic follow-up evaluations. In no patients did arterial recanalization or the neovascular recruitment phenomenon occur. Our initial results indicate that ethanol has a permanence that is seldom encountered with other embolic agents. With aggressive decadron therapy, the complications related to swelling in the brain are largely reversible.

Arteriovenous malformations (AVM) are rare vascular lesions that can present with a myriad of clinical presentations. In our institutions, initial workup consists of a clinical exam, color Doppler imaging, and magnetic resonance imaging. After the initial nonivasive workup, arteriography, at times closed system venography, and ethanol endovascular repair of the AVM is performed under general anesthesia. Depending on the size of the lesion, additional Swan-Ganz line and arterial line monitoring are performed. Patients are usuallay observed overnight and uneventfully discharged the following day if no complication occurs. Patients are followed at periodic intervals despite cure of their lesion. Long-term follow-up is essential in AVM management.

To evaluate the efficacy of ultrasound (US)-guided automated large-core percutaneous needle breast biopsy, biopsy of 181 ultrasonographically suspicious breast lesions was performed by using a long-throw biopsy gun and 14-gauge needles with continuous US guidance. A "freehand" technique with either 5.0- or 7.5-MHz linear-array transducers was used. Needle core diagnoses were compared with surgical diagnoses in the 49 lesions subsequently surgically excised. The remaining 132 cases were followed for 12-36 months. Agreement between needle-core and surgical diagnoses in the 49 lesions was 100%. This group included 34 cancers (28 infiltrating ductal, two mucinous, one mixed infiltrating ductal and lobular, and one each of intraductal, infiltrating lobular, and tubular carcinoma). To date, no cancers have been found in the other 132 cases. The procedure time averaged 20 minutes, and no complications occurred. With an accuracy approaching that of excisional biopsy, US-guided needle core biopsy provides an alternative to surgery.

Segmental renal artery branches within the renal sinus were prospectively evaluated with color Doppler imaging and pulsed-Doppler spectral analysis in 56 patients before angiography. Waveforms were evaluated for the tardus and parvus abnormalities of prolonged acceleration time, diminished acceleration index, and loss of the normal early systolic compliance peak/reflective-wave complex (ESP). Findings obtained with these parameters were compared with the subsequent findings on angiograms to ascertain their efficacy in detection of hemodynamically significant (greater than or equal to 60%) renal arterial stenosis (RAS), which was present in 32 kidneys in 26 patients. Simple pattern-recognition analysis of ESP proved to be the best of the three parameters. Loss of ESP enabled identification of RAS with 95% sensitivity, 97% specificity, a 92% positive predictive value, a 98% negative predictive value, a 96% overall accuracy. On the basis of the high technical success rate, high sensitivity and specificity, and short examination time, waveform analysis for detection of tardus-parvus abnormalities, especially loss of ESP, of the segmental artery is recommended as an alternative to direct examination of the main renal arteries for evaluation of RAS.

Embolization procedures have evolved as one of the cornerstones of modern interventional radiology.

Vascular malformations of bone are extremely complex lesions that can present with a myriad of symptomologies. Ethanol endovascular and direct puncture embolization can cure or significantly obliterate these lesions at long-term follow-up. Further, ethanol sclerotherapy in conjunction with coil embolization can treat massive lesions and cure them at long-term follow-up. In low-flow lesions, direct puncture injection of the vein malformation can be curative, lead to new bone formation or obliteration of the vascular cyst, and obviate the need for complex surgeries and their attendant complications.

One hundred two patients with mammographically suspicious, nonpalpable lesions underwent stereotactic breast biopsy with a biopsy gun and an automated 14-gauge cutting needle. After biopsy, a localization wire was placed and surgical biopsy performed. There was agreement of the histologic results from the gun biopsy and the surgical biopsy specimens in 98 cases (96%), including 22 of 23 carcinomas (96%) (kappa = 0.936). The gun biopsy yielded findings that led to the correct diagnosis in two cases involving lesions that were missed at surgical biopsy; two lesions found at surgery were missed at gun biopsy. The results of this study suggest that the use of 14-gauge needles improves agreement between surgical and needle core biopsy findings and that stereotactic biopsy with an automated needle and gun can be an acceptable alternative to surgical biopsy in women with mammographically suspicious breast lesions.

Debate over which biopsy needle is the best has intensified recently with the introduction of automated biopsy guns including the 18-gauge long-throw and short-throw Biopty, the 18-gauge Cook, and the 14- and 18-gauge Klear Kut. To evaluate the efficacy of these mechanized biopsy guns versus that of conventional manual biopsy needles in the acquisition of adequate tissue for histopathologic evaluation, open hepatic and renal biopsies were performed in 15 pygmy pigs. The specimens were evaluated separately in a double-blind fashion by two histopathologists using graded criteria. Overall, the best results were obtained with the manual 14-gauge Tru-Cut needle, the long-throw 18-gauge Biopty gun, and the 18-gauge Cook biopsy gun. By comparison, the aspiration-type needles did not perform as well when considered as a group. Several other needles scored well in the biopsy of either the liver or kidney, but not in both. Disappointing results were obtained with the Klear Kut guns (both 14- and 18-gauge) and the V...

One hundred three patients underwent stereotactic breast biopsy with an 18-, 16-, or 14-gauge cutting needle and a biopsy gun. After biopsy, a localization wire was placed and surgical biopsy performed. There was agreement of the histologic results in 89 cases (87%) including 14 of 16 cancers (87%) (kappa = 0.806). The gun biopsy yielded the correct diagnosis in four cases involving a lesion (including one cancer) that was missed at the surgical biopsy. Nine cases in which the lesion was missed at gun biopsy can be related to insufficient needle size, the greater difficulty in using one of the two stereotactic devices, and early inexperience with the technique. A 14-gauge needle was used in the last 29 biopsies, the results of which agreed with the surgical pathologic findings in 28 cases (97%). With greater experience, stereotactic-guided large-gauge automated percutaneous biopsy may prove to be an acceptable alternative to surgical biopsy in women with breast masses suspected at mammography.

This article describes the various methods of endovascular management of high-flow arteriovenous malformations. Concepts of patient management and various therapies for vascular malformations are discussed. Nontraumatic acquired arteriovenous malformations, arteriovenous fistulae, and endovascular treatment of arteriovenous malfromations are described.

'From the Divisions of Vascular Surgery (H.W.H., A.L.B.) and Intementional Radiology (J.M.L., W.F.Y.), Fitzsimons Army Medical Center, Aurora, Colo. Received June 2, 1993; revision requested July 12; revision received November 27; accepted December 8. Address reprint requests to H.W.H., Department of Surgery, Kaiser Permanente, 2045 Franklin St, Denver, CO 80205. The opinions expressed in this manuscript represent the private views of the authors and do not reflect the views of the United States Army or Department of Defense. Current address: Intementional Radiology and Neuroradiology, Radiology Imaging Associates, Englewood, Colo. Current address: Department of Surgery, United States Military Academy Hospital, West Point, NY.

Summary Venous malformations of the rectum are uncommon lesions that present complex management problems (1-6). The vast majority of these lesions present with rectal bleeding in infancy or childhood. Many cases have been treated as colitis for years before the correct diagnosis was made. The correct diagnosis has generally been based on gross appearance, confirmed subsequently by plain radiographs and angiography. Heroic surgical intervention has been the only repeatedly reported “cure” in the literature. One patient has been reported who did well for 20 years with sclerosis of the hemorrhoidal vein at surgery followed by intermittent transrectal sclerotherapy (7,8). Another patient would appear to have had long-term success with radiation therapy (9-11). We report four new cases of venous malformations of the rectum and results to date of a new therapeutic option with transcutaneous ethanol sclerotherapy in two of these patients. A discussion of alternate methods of treatment is included.

Arteriovenous fistulas (AVFs) can be posttraumatic or congenital vascular malformations. In the initial arteriographic evaluation, chronic AVFs potentially can be confused with arteriovenous malformations (AVMs). The authors studied five patients with a single AVF and one patient with numerous AVFs. Three patients had undergone surgery for treatment of their AVFs, one patient had undergone isobutyl-2-cyanoacrylate (IBCA) embolization, and two patients had undergone no prior therapy. The AVFs recurred in the three patients who had undergone surgery and in the patient who had undergone IBCA embolization. All patients underwent ethanol embolization of their AVFs. Angiograms obtained immediately after embolization documented closure of all AVFs. At follow-up, none of the embolized lesions have recurred. The authors conclude that ethanol embolotherapy can cure these problematic lesions. Extreme caution, however, must be employed with the use of intravascular ethanol because nontarget embolization can potentially result in tissue devitalization. In this study, two patients developed a small focal area of skin necrosis that did not require skin grafting and healed with conservative management.

Absolute ethanol was used to treat 20 patients with symptomatic vascular malformations (SVMs) (ie, venous malformations, arteriovenous malformations, and congenital and posttraumatic arteriovenous fistulas) in whom previous surgery or standard embolotherapy had failed or who were not candidates for surgery. All large complex lesions required multiple embolizations as staged procedures. Immediate thrombosis was achieved in all patients; complications (13% of cases) were generally minor and were treated conservatively. Follow-up studies, performed in 19 of 20 patients, showed persistent occlusion of the SVM in all cases. Ethanol embolization of SVMs, performed according to strict techniques, has proved efficacious in SVM management and is emerging as a definitive form of therapy.

Absolute ethanol was used to perform nine transcatheter embolizations and 21 direct percutaneous puncture embolizations in eight patients with unresectable vascular malformations. Six patients had arteriovenous malformations and two patients had hemangiomas. Four of these patients had undergone unsuccessful surgery, and the other four were not considered candidates for operation. All large complex symptomatic vascular malformations (SVMs) required multiple embolizations that were staged procedures. Ethanol embolotherapy, performed according to strict techniques, has proved efficacious in the management of SVMs.

Using absolute ethanol, 40 embolizations were performed in 10 patients: 14 transcatheter embolizations and 26 direct percutaneous puncture embolizations. Direct percutaneous puncture techniques were developed to circumvent catheterization obstacles secondary to tortuous vessels and previous surgical arterial ligations and to attack postcapillary hemangiomatous lesions

Angioplasty of the aorta has been undertaken by a few investigators. Several approaches to percutaneous transluminal aortic angioplasty (PTAA) have evolved, depending on the areas of atheromatous involvement. In this series, PTAA was performed on 19 patients. There was one death secondary to myocardial infarction in the postangioplasty period, but no complication directly related to PTAA occurred

Core tissue for histologic study is believed by many pathologists to be more diagnostic than material from needle aspiration. Recently, a biopsy "gun" has been introduced, which simplifies core biopsies. With this device, 182 biopsies of multiple anatomic sites were performed with ultrasonic, computed tomographic, and fluoroscopic guidance and 18-gauge needles. High-quality histopathologic specimens were obtained in 177 of the biopsies, and diagnostic target tissue was obtained in 167. Only three significant complications occurred: one bleeding complication that required transfusion and two cases of pneumothorax that necessitated placement of chest tubes. The biopsy gun eliminated the disjointed movements of conventional "skinny" needle biopsies, and none of the samples demonstrated significant "crush" artifact or obscuring blood, problems that are commonly associated with manual biopsy techniques. Patient discomfort was decreased with this system compared with that of manual biopsies, and the total procedure time was reduced. Because of these distinct advantages, the authors now use the biopsy gun exclusively for all percutaneous biopsies and recommend that other institutions consider the use of this biopsy method.

Background Management of arteriovenous malformations (AVMs) remains challenging because of their unpredictable behavior and high recurrence rate. A multidisciplinary approach based on a new classification scheme and improved diagnostic techniques may improve their management. The purpose of this study was to review our experience with combined embolotherapy, sclerotherapy (embolo/sclerotherapy), and surgical procedures to manage AVMs. Methods A total of 797 patients with congenital vascular malformations (January 1995 through December 2001) was investigated with noninvasive studies. Once an AVM was diagnosed, all underwent angiographic confirmation as a roadmap for treatment. Embolo/sclerotherapy and surgical procedures were instituted by the multidisciplinary team with periodic follow-up per protocol. Seventy-six patients with AVMs were reviewed retrospectively to assess the diagnosis and management by a multidisciplinary approach. Results Seventy-six (9.5% of all CVM) patients had AVMs, mostly infiltrating, extratruncular form (61/76). Embolo/sclerotherapy with various combinations of absolute ethanol, N -butyl cyanoacrylate (NBCA), contour particles, and coils were used in 48 patients. Sixteen patients with surgically accessible localized lesions completed preoperative embolism and sclerotherapy through 24 sessions, with subsequent surgical excision with minimal morbidity. Interim results were excellent, with no evidence of recurrence in all 16 patients with a mean follow-up of 24 months. Thirty-two patients with surgically inaccessible lesions (infiltrating) were treated with embolism and sclerotherapy alone. There were nine failures in a total of 171 sessions. Interim results with a mean of 19 months' follow-up of embolism and sclerotherapy alone were excellent in the majority (25/32) and good to fair among the rest (7/32). However, 31 complications, mostly minor (27/31), occurred in 30 sessions. Four major complications occurred, including facial nerve palsy, pulmonary embolism, deep vein thrombosis, and massive necrosis of an ear cartilage. Conclusions Diagnosis and management of AVMs by a multidisciplinary approach that integrates surgical therapy with embolism and sclerotherapy appears to improve the results and management with limited morbidity and no recurrence during early follow-up.

Inadvertent placement of a Kimray-Greenfield filter into the right side of the heart occurred in the operating room. With the use of intraoperative fluoroscopy while the patient remained under general anesthesia, the filter was extracted and successfully placed in the inferior vena cava. This was accomplished with standard percutaneous catheter techniques from the femoral route.

Percutaneous transluminal angioplasty of the infrarenal abdominal aorta has been reported by a few authors. In the present series, aortic stenoses in 32 patients were treated with various percutaneous angioplasty techniques. Isolated aortic stenoses and primary aortic stenoses extending into the iliac arteries were successfully dilated. The initial success rate was 100%, without evidence of rupture, thrombosis, dissection, or distal embolization. In only three of the 28 patients who returned for follow-up did symptoms recur or noninvasive vascular laboratory indexes deteriorate (mean follow-up, 25 months). Percutaneous transluminal aortic angioplasty has proved safe and efficacious in the treatment of atherosclerotic aortic stenoses.