Keith Pereira

The Global Nonalcoholic Fatty Liver Disease Epidemic: What a Radiologist Needs to Know.

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of disorders from a benign steatosis to hepatocellular carcinoma (HCC). Metabolic syndrome, mainly obesity, plays an important role, both as an independent risk factor and in the pathogenesis of NAFLD. With the progressive epidemics of obesity and diabetes mellitus, the prevalence of NAFLD and its associated complications is expected to increase dramatically. Therapeutic strategies for treating NAFLD and metabolic syndrome, particularly obesity, are continuously being refined. Their goal is the prevention of NAFLD by the management of risk factors, prevention of progression of the disease, as well as management of complications, ultimately preventing morbidity and mortality. Optimal management of NAFLD and metabolic syndrome requires a multidisciplinary collaboration between the government as well as the health system including the nutritionist, primary care physician, radiologist, hepatologist, oncologist, and transplant surgeon. An awareness of the clinical presentation, risk factors, pathogenesis, diagnosis, and management is of paramount importance to a radiologist, both from the clinical perspective as well as from the imaging standpoint. With expertise in imaging modalities as well as minimally invasive percutaneous endovascular therapies, radiologists play an essential role in the comprehensive management, which is highlighted in this article, with cases from our practice. We also briefly discuss transarterial embolization of the left gastric artery (LGA), a novel method that promises to have an enormous potential in the minimally invasive management of obesity, with details of a case from our practice.

Current diagnosis and management of post-transjugular intrahepatic portosystemic shunt refractory hepatic encephalopathy.

Transjugular intrahepatic portosystemic shunt has evolved into an important option for management of complications of portal hypertension. The use of polytetrafluoroethylene covered stents enhances shunt patency. Hepatic encephalopathy (HE) remains a significant problem after TIPS placement. The approach to management of patients with refractory hepatic encephalopathy typically requires collaboration between different specialties. Patient selection for TIPS requires careful evaluation of risk factors for HE. TIPS procedure‐related technical factors like stent size, attention to portosystemic pressure gradient reduction and use of adjunctive variceal embolization maybe important. Conservative medical therapy in combination with endovascular therapies often results in resolution or substantial reduction of symptoms. Liver transplantation is, however, the ultimate treatment.

Prostate Artery Embolization (PAE) in the Management of Refractory Hematuria of Prostatic Origin Secondary to Iatrogenic Urological Trauma: A Safe and Effective Technique

INTRODUCTION Incidence of refractory hematuria of prostatic origin (RHPO) is extremely rare, with an iatrogenic etiology even rarer. When conservative methods fail to control bleeding, more invasive surgical methods are needed. In this article we describe our experience with prostatic artery embolization (PAE) as a minimally invasive alternative treatment option in patients with RHPO secondary to iatrogenic urologic trauma. TECHNICAL CONSIDERATIONS Three patients presented with RHPO. The etiologies were transurethral resection of prostate surgery, Foley catheter removal with a supratherapeutic international normalized ratio and self-traumatic Foley catheter removal respectively. Stepwise management with conservative and medical methods failed to control bleeding. Under local anesthesia and moderate sedation, bilateral PAE was performed via a right common femoral artery access and using cone beam computed tomography. An embolic mixture containing 300-500 um Embosphere® Microspheres (Biosphere Medical, Rockland, MA) was injected under fluoroscopic guidance until stasis was achieved. PAE using the described technique was a technical and clinical success in all three patients. Hematuria resolved within a period of 24 hours. There were no intra- or periprocedural complications. CONCLUSION PAE offers a reasonable option in treatment of RHPO, regardless of the cause and may be attempted prior to surgical techniques or sometimes in conjunction. Being minimally invasive and performed under local anesthesia, PAE is especially useful when excessive bleeding prevents adequate visualization of a bleeding source during cystoscopy and in the elderly age group with several comorbidities. An added advantage is the prostatic parenchymal ischemia leading to significant prostate volume reduction and alleviation of the obstructive symptoms.

Endovascular Coil Embolization in the Treatment of a Rare Case of Post-Traumatic Abdominal Aortic Pseudoaneurysms: Brief Report and Review of Literature

Traumatic aortic injury, a consequence of penetrating injuries or blunt trauma, is a life threatening condition which requires prompt diagnosis and management. Most abdominal aortic injuries have been repaired via an open surgical approach with endovascular stent graft as an alternative. Traumatic pseudoaneurysms (PSA) of the abdominal aorta are uncommon, and they are managed similar to other abdominal aortic injuries. However, the presence of a perianeurysmal hematoma and the potential risk of an associated concomitant bowel communication could make surgery and endovascular stent graft placement risky. In such patients, coil embolization could be a valued option. In this article, we present a case in which traumatic PSAs are repaired using coil embolization with technical and clinical success. Endovascular coil embolization could be an alternative approach for PSAs that cannot be treated by stent grafting or open surgical repair, in the appropriate anatomy and by using the right coil material and technique.

Vascular Access for Placement of Tunneled Dialysis Catheters for Hemodialysis: A Systematic Approach and Clinical Practice Algorithm

The role of interventional radiology in the overall management of patients on dialysis continues to expand. In patients with end-stage renal disease (ESRD), the use of tunneled dialysis catheters (TDCs) for hemodialysis has become an integral component of treatment plans. Unfortunately, long-term use of TDCs often leads to infections, acute occlusions, and chronic venous stenosis, depletion of the patient′s conventional access routes, and prevention of their recanalization. In such situations, the progressive loss of venous access sites prompts a systematic approach to alternative sites to maximize patient survival and minimize complications. In this review, we discuss the advantages and disadvantages of each vascular access option. We illustrate the procedures with case histories and images from our own experience at a highly active dialysis and transplant center. We rank each vascular access option and classify them into tiers based on their relative degrees of effectiveness. The conventional approaches are the most preferred, followed by alternative approaches and finally the salvage approaches. It is our intent to have this review serve as a concise and informative reference for physicians managing patients who need vascular access for hemodialysis.

An Approach to Endovascular and Percutaneous Management of Transjugular Intrahepatic Portosystemic Shunt (TIPS) Dysfunction: A Pictorial Essay and Clinical Practice Algorithm

Transjugular intrahepatic portosystemic shunts (TIPS) have evolved as an effective and durable nonsurgical option in the treatment of portal hypertension (PH). It has been shown to improve survival in decompensated cirrhosis and may also serve as a bridge to liver transplantation. In spite of the technical improvements in the procedure, problems occur with the shunt which jeopardizes effective treatment of the PH. Appropriate management is vital to ensure the longevity of the conduit. Shunt revision techniques include endovascular revision techniques and new shunt creation or, in the appropriate patients, alternative/rescue therapies. The ability of interventional radiologists to restore adequate TIPS function has enormous implications for quality of life with palliation, morbidity/mortality related to variceal bleeding and survival if transplant candidates can live long enough to receive a new liver. As such, it is imperative that these treatment strategies are understood and employed when these patients are encountered. In this review, the restoration of appropriate shunt function using various techniques will be discussed as they apply to a variety of clinical scenarios, based on literature. In addition, illustrative case examples highlighting our experience at an academic tertiary medical center will be included. It is the intent to have this document serve as a concise and informative reference to be used by those who may encounter patients with suboptimal functioning TIPS.

Radiofrequency ablation in primary non-small cell lung cancer: What a radiologist needs to know.

Lung cancer continues to be one of the leading causes of death worldwide. In advanced cases of lung cancer, a multimodality approach is often applied, however with poor local control rates. In early non-small cell lung cancer (NSCLC), surgery is the standard of care. Only 15-30% of patients are eligible for surgical resection. Improvements in imaging and treatment delivery systems have provided new tools to better target these tumors. Stereotactic body radiation therapy (SBRT) has evolved as the next best option. The role of radiofrequency ablation (RFA) is also growing. Currently, it is a third-line option in stage 1 NSCLC, when SBRT cannot be performed. More recent studies have demonstrated usefulness in recurrent tumors and some authors have also suggested combination of RFA with other modalities in larger tumors. Following the National Lung Screening Trial (NLST), screening by low-dose computed tomography (CT) has demonstrated high rates of early-stage lung cancer detection in high-risk populations. Hence, even considering the current role of RFA as a third-line option, in view of increasing numbers of occurrences detected, the number of potential RFA candidates may see a steep uptrend. In view of all this, it is imperative that interventional radiologists be familiar with the techniques of lung ablation. The aim of this article is to discuss the procedural technique of RFA in the lung and review the current evidence regarding RFA for NSCLC.

Use of Intrarterial Carbon Dioxide-Enhanced Ultrasonography (COEUS) in Patient with Renal Insufficiency Undergoing Trans Arterial-Chemo-Embolization (TACE).

To the Editor, Trans-arterial chemoembolization (TACE) is a form of locoregional therapy in hepatocellular carcinoma (HCC), either as a bridge to transplant or for palliation. With the growing acceptance of TACE in clinical practice, contrastinduced nephropathy (CIN) is now encountered more commonly with a reported incidence that varies between 3.2 and 21 % [1]. On an average about 259 ml of contrast [2] is used during the procedure, increasing the chances of CIN. Possible risk factors include increased Child-Pugh score, presence of ascites, volume of contrast used, total bilirubin, basal serum creatinine/glomerular filtration rate levels and prior history of renal injury after TACE [2]. The development of post-TACE renal insufficiency is associated with the risk of prolonged renal insufficiency, need for renal replacement therapy, and mortality [1]. Thus, a patient with renal insufficiency presents a dilemma to the treating interventional radiologist performing TACE. We present a case in our practice where we used intrarterial carbon dioxide-enhanced ultrasonography (COEUS) during TACE. A 65-year-old female presented with Hepatitis C and liver cirrhosis. MRI revealed a 5.2 9 4.8 cm mass in the left lobe of her liver with imaging features characteristic of an HCC. Being outside of the transplant criteria, ECOG 1 and Child Pugh A, it was decided to bridge her to transplant with locoregional therapy like TACE. Ablative therapy was not considered in this case as the transplant surgeons were not comfortable due to potential risk of seeding of tumor in a potential transplant candidate and the patient had a large amount of ascites. Our patient, however, had impaired renal functionwith an elevated creatinine of 2.8, GFR\30 mL/min.We decided to use carbon dioxide (CO2) as a contrast agent. The tumor was outlined using CO2 DSA, confirmed on COEUS and a small amount of iodinated contrast (about 4 cc) TACE was performed according to protocol again using a small amount of iodinated contrast (about 5 cc) (Fig. 1). Patient tolerated the procedure well. Her serum creatinine remained at 2.8 after the procedure. She was successfully bridged to liver transplant in the next 12 months.

Antegrade embolization of spontaneous splenorenal shunt for Post‐TIPS refractory Hepatic Encephalopathy

Recently, Wu et al. reported on a rare case of spontaneous port systemic shunt (SPSS) embolization for post–transjugular intrahepatic portosystemic shunt (TIPS) refractory hepatic encephalopathy (rHE). This retrograde approach has also been described by Shioyama et al. We report on a similar case, treated by a different approach. An 82-year-old male with decompensated cirrhosis had TIPS for treatment of esophageal variceal bleeding. He developed rHE. Model for End-Stage Liver Disease (MELD) score was 11, and ammonia was 35 mcmol/L. TIPS reduction was performed. A 70% luminal reduction was achieved, but portosystemic gradient (PSG) barely increased from 3 to 6 mm Hg. Further shunt reduction was avoided to prevent complete shunt thrombosis. He returned 2 weeks later with a recurrent rHE. MELD was 14, and ammonia was 90 mcmol/L. Initial intent was shunt occlusion. Portal venogram revealed multiple gastric varices with hepafugal flow. We elected to prophylactically embolize the afferent veins to gastric varices, to prevent bleeding after shunt occlusion. The posterior and short gastric veins were embolized using coils. Left gastric venogram showed a large gastrorenal SPSS. Although Balloon-occluded retrograde transvenous obliteration (BRTO) is the preferred method of SPSS embolization, it can cause catastrophic bleeding as a result of aggravation of esophageal varices. We embolized the left gastric vein antegradely. PSG increased from 6 to 14 mmHg, and there was improved hepatopetal flow. Shunt occlusion was not performed. The patient’s mental status dramatically improved within 20 minutes of the procedure. At 20-week follow-up, he had marked improvement in cognition and baseline level of mental acuity. MELD score improved to 10. High-risk gastroesophageal varices have not redeveloped to date. In patients with a SPSS and coexisting TIPS, two shunts induce excessive portosystemic shunting and severe HE.Although antegrade embolization with coils can cause bleeding as a result of injury to friable variceal walls, this technique has been safely described in the past. Based on our experience and previous case reports, we think that (1) a thorough search for an SPSS is warranted in cases of post-TIPS rHE and (2) antegrade embolization may have a dual role in the prevention of variceal bleeding in addition to treatment of rHE, the former being a significant concern when themore conventional retrograde approach is used.

Treatment of Chyle Leak by Percutaneous Alcohol Sclerosis of the Cisterna Chyli: A Case Report

Chyle leak is a highly morbid condition, which, when persistent, can lead to life-threatening malnutrition, infection, and prolonged hospital stay. When traditional treatments fail, a surgical approach is normally indicated. Embolization, typically with coils or liquid embolic agents, has been described [1–3]. We report a case of chyle leak following right upper lobe lobectomy managed successfully by percutaneous alcohol sclerosis of the cisterna chyli after failed conservative management.