Preparing IR for COVID-19: The Singapore Experience.

This paper describes country-wide special measures undertaken for interventional radiology staff during the current coronavirus disease 2019 (COVID-19) pandemic. Although each interventional radiology service around the world faces unique challenges, the principles outlined in this article will be useful when designing or strengthening individual practices and integrating them within wider hospital and national measures. Moving beyond the current outbreak, these measures will be useful for any future infectious diseases which are likely to arise.

Diabetic Foot Limb Salvage-A Series of 809 Attempts and Predictors for Endovascular Limb Salvage Failure.

BACKGROUND: To review patient characteristics and outcomes of in-patient diabetic foot limb salvage and identify risk factors predicting for endovascular limb salvage failure. METHODS: Retrospective study of limb salvage attempts in 809 patients between August 2013 and July 2015. RESULTS: Sixty-eight percent of our study population were male with mean age at 65 years and 73% presented with Rutherford grade 6 critical limb ischemia, with the remaining 27% Rutherford grade 5. Eighty-one percent had toe pressures of less than 50 mm Hg, 64% had infrainguinal trans-Atlantic inter-society consensus (TASC II) C or D lesions while 78% had infrapopliteal TASC II C or D lesions. Seven hundred seventy-seven patients (96%) underwent endovascular-first approach limb salvage, with 95% requiring infrapopliteal angioplasty, with 84% of them requiring 2-vessel or 3-vessel revascularization. Thirty-two patients (4%) underwent surgical bypass limb salvage, with 63% performed as salvage procedures for failed angioplasties. The mean in-patient stay was 12.3 days within the endovascular group and 31.1 days within the bypass group (P < 0.01). One-year limb salvage was successful in 88% of endovascular group, as compared with 72% in bypass group (P = 0.01). Overall 1-year survival was 93% within the endovascular group and 88% within the bypass group (P = 0.27). The mean in-patient cost was SGD$5,518 within the endovascular group and SGD$15,141 within the bypass group (P < 0.01). Multivariate analysis showed that independent predictors for failure of endovascular limb salvage include end-stage renal failure (ESRF) (odds ratio [OR] 2.04, P = 0.01), toe pressures <50 mm Hg (OR 2.15, P = 0.01), infrainguinal TASC II patterns C or D (OR 1.99, P = 0.03), and indirect angiosome revascularization (OR 2.03, P = 0.02). CONCLUSIONS: Within our study population of Asian ethnicity, most in-patient diabetic foot peripheral arterial disease presented with Rutherford grade 6 disease, with mostly TASC II C or D lesions and required infrapopliteal revascularization. As most patients had multiple comorbidities and were poor surgical candidates, the majority underwent endovascular-first approach revascularization. Independent predictors of endovascular limb salvage failure include ESRF, toe pressures <50 mm Hg, infrainguinal TASC II patterns C or D, and indirect angiosome revascularization.

Chimney Stent-Graft Repair for Concurrent Inferior Mesenteric Artery Aneurysm and Infrarenal Abdominal Aortic Aneurysm: Case Report.

PURPOSE: To report a rare case of concurrent inferior mesenteric artery (IMA) aneurysm and infrarenal abdominal aortic aneurysm (AAA) with a novel indication for the use of chimney stent-graft technique in this patient. CASE REPORT: An 82-year-old man with an asymptomatic 4.4-cm fusiform AAA and 3.6-cm IMA aneurysm, coupled with chronic occlusion of celiac artery and superior mesenteric artery at the ostia, underwent endovascular repair of both aneurysms. Preservation of the IMA and treatment of both aneurysms were achieved with IMA aneurysm stenting, aortic aneurysm stenting and IMA chimney stenting. At 1, 6, and 12 months surveillance, the grafts remained patent without endoleak. CONCLUSIONS: The IMA chimney with aortic stenting technique may be safely used in patients who require preservation of the IMA during AAA and IMA aneurysm repairs.

Asia-Pacific consensus recommendations for endoscopic and interventional management of hilar cholangiocarcinoma.

Hilar cholangiocarcinoma (HCCA) is one of the most common types of hepatobiliary cancers reported in the world including Asia-Pacific region. Early HCCA may be completely asymptomatic. When significant hilar obstruction develops, the patient presents with jaundice, pale stools, dark urine, pruritus, abdominal pain, and sometimes fever. Because no single test can establish the definite diagnosis then, a combination of many investigations such as tumor markers, tissue acquisition, computed tomography scan, magnetic resonance imaging/magnetic resonance cholangiopancreatography, endoscopic ultrasonography/intraductal ultrasonography, and advanced cholangioscopy is required. Surgery is the only curative treatment. Unfortunately, the majority of HCCA has a poor prognosis due to their advanced stage on presentation. Although there is no survival advantage, inoperable HCCA managed by palliative drainage may benefit from symptomatic improvement. Currently, there are three techniques of biliary drainage which include endoscopic, percutaneous, and surgical approaches. For nonsurgical approaches, stent is the most preferred device and there are two types of stents i.e. plastic and metal. Type of stent and number of stent for HCCA biliary drainage are subjected to debate because the decision is made under many grounds i.e. volume of liver drainage, life expectancy, expertise of the facility, etc. Recently, radio-frequency ablation and photodynamic therapy are promising techniques that may extend drainage patency. Through a review in the literature and regional data, the Asia-Pacific Working Group for hepatobiliary cancers has developed statements to assist clinicians in diagnosing and managing of HCCA. After voting anonymously using modified Delphi method, all final statements were determined for the level of evidence quality and strength of recommendation.

Single-centre experience with endovascular rotational thrombectomy for single session salvage of thrombosed arteriovenous fistulas and grafts.

OBJECTIVES: This paper documents our experience and outcomes of using a relatively new endovascular rotational thrombectomy device for salvage of thrombosed vascular access. METHODOLOGY: A retrospective study reviewing patients with thrombosed native AVF or AVG who underwent endovascular declotting using a rotational thrombectomy device between November 2018 and May 2020 at a tertiary university hospital in Southeast Asia. We evaluated demographics, procedural data, technical and procedural success, patency rates and complications. RESULTS: A total of 40 patients underwent single session endovascular declotting of thrombosed vascular access. The mean follow-up period was 21.6 months (range 13.4-31 months). The technical success was 92.5% and clinical success was 80%. About 50% of patients had concomitant thrombolysis for pharmacomechanical thrombectomy. One patient had a myocardial infarction during the post-operative period. There were no other major complications within 30 days. The primary patency was 45.5% at 6 months and 22.7% at 12 months. Assisted primary patency was 68.1% at 6 months and 61.6% at 12 months, which was maintained up to 2 years. The secondary patency was 84.1% at 6 and 12 months. CONCLUSION: Our study shows that rotational thrombectomy device for single session thrombectomy of thrombosed arteriovenous fistulas and grafts is safe and effective. A high technical and clinical success rate was achieved, with low complication rates and specific advantages compared to other techniques, including reduced length of hospital stay. Our reported mid-term outcomes are reasonable with an assisted primary patency of 62% at 12 and 24 months. The use of newer techniques and novel dedicated thrombectomy devices show promise.

Aortoenteric fistula treated with endovascular aortic stent-graft and bilateral chimney stent-grafts to renal arteries.

We report a patient with secondary aortoenteric fistula (AEF) presenting with a rectal bleeding. The patient had multiple comorbidities, precluding major open vascular surgery. We opted to perform a two-stage procedure, where an endovascular stent-graft was first deployed to exclude the AEF from the systemic circulation. As the AEF was at the proximal anastomosis of the previous Dacron graft and close to the renal artery ostia, chimney stent-grafts were placed in both renal arteries to maintain their patency. The second stage of the procedure involved a laparotomy to repair the defect in the duodenum to prevent further contamination from bowel contents.

Use of trans-biliary rendezvous technique for stenting of an impassable duodenal stricture.

Stenting of the gastric outlet is an accepted method for palliation of symptoms secondary to inoperable malignancy and is successful in most cases. Failure of stenting is most commonly due to inability to cross the stricture. We describe a rendezvous technique of duodenal stenting via transhepatic biliary access when conventional endoscopic or fluoroscopic methods fail.

Management of blunt traumatic thoracic aorta injuries with endovascular stent-grafts in a tertiary hospital in an urban Asian city.

BACKGROUND: Thoracic aortic injury from blunt trauma is a life-threatening condition with significant mortality and morbidity with open surgical repair. Endovascular means of treatment is emerging as an attractive and less invasive option. We report our experience with endovascular stent-graft repair for blunt traumatic thoracic aorta injury. METHODS: Between January 2003 and August 2009, six patients underwent endovascular repair of blunt traumatic thoracic aorta injury. Data from the medical records of these patients were analyzed. RESULTS: All patients had deceleration injury resulting in thoracic aorta pseudoaneurysm at the aortic isthmus just distal to the left subclavian artery. Four patients were motorcyclists who had been involved in road-traffic accidents and two had fallen from a height. The mean Injury Severity Score was 33.8 (range, 21-43). All procedures were performed within 48 hours of admission and technical success was 100%. Five patients (83.3%) had the left subclavian artery intentionally covered by the stent-graft to achieve adequate proximal landing zone. None of them had any left upper limb ischemic complications or cerebrovascular events after the procedure. One patient had preservation of the left subclavian artery because intraoperative vertebral angiogram showed a hypoplastic right vertebral artery. No other procedural complications, paraplegia, or deaths were reported. Mean follow-up was 18.8 months (range, 1.5-42 months). CONCLUSIONS: Our early experience of endovascular stent-grafting for blunt traumatic thoracic aorta injury suggests that this emerging technique is safe for treatment of such pathology in our inherently Asian population. Left subclavian artery may be sacrificed if adequate proximal landing zone is required for the stent-graft; and when vertebral angiogram was performed which did not show a dominant left vertebral artery.

Prevalence of JAK29V617F) mutation in intra-abdominal venous thrombosis.

BACKGROUND AND AIM: Myeloproliferative disorders (MPD) (like polycythemia vera, essential thrombocythemia and primary myelofibrosis) are responsible for 50% cases of Budd-Chiari syndrome (BCS) and 35% cases of portal venous thrombosis (PVT) in western series. A point mutation at Val617Phe of Janus kinase 2 tyrosine kinase gene (JAK2(V617F) mutation) occurs in high proportion with MPD. This may be useful in diagnosing overt and latent form of MPD in intra-abdominal venous thrombosis (IAVT), consisting of BCS and PVT. METHODS: In a 4 year prospective study from 2006 to 2009, JAK2 mutations were assessed in all patients diagnosed with MPD and IAVT attending our institution. Twenty three healthy individuals and 31 patients with non-MPD hematological disorders served as controls. All patients of idiopathic IAVT were tested for the mutation. Test for JAK2(V617F) mutation was carried out by allele specific polymerase chain reaction. RESULTS: JAK2(V617F) mutation was significantly more common in MPD patients (76%) than in non-MPD hematological disorders (0%) and healthy controls (0%). There was no statistical difference in presence of JAK2(V617F) mutation in patients of MPD with or without thrombosis (80% vs. 74%). In 58 patients with IAVT, the JAK2(V617F) mutation was present in 40% with BCS, 14% with PVT and 100% combined BCS+PVT). CONCLUSIONS: The JAK2(V617F) mutation occurs at high frequency in patients with MPD and IAVT. All idiopathic IAVT patients must be screened for JAK2(V617F) mutation to detect latent MPD. Detection of latent MPD by JAK2(V61F) mutation in BCS may change treatment strategy and outcome.

Role of Intercostal Artery Embolization in Management of Traumatic Hemothorax.

Intercostal artery bleeding from trauma can result in potentially fatal massive hemothorax. Traumatic hemothorax has traditionally been treated with tube thoracostomy, video-assisted thoracoscopic surgery, or thoracotomy. Transcatheter arterial embolization (TAE), a well-established treatment option for a variety of acute hemorrhage is not widely practiced for the management of traumatic hemothorax. We present 2 cases of delayed massive hemothorax following chest trauma which were successfully managed by transarterial embolization of intercostal arteries. The published studies are reviewed and a systematic approach to the selection of patients for TAE versus emergency thoracotomy is proposed.

Outcomes of Catheter-Directed Thrombolysis for Arteriovenous Fistula Thrombosis in Singapore: Is It Still Relevant Today?

Objective: To review the outcomes of catheter-directed thrombolysis (CDT) for salvage of thrombosed arteriovenous fistula (AVF) in a single centre in Southeast Asia. Methods: A retrospective study of CDT in AVF between January 2015 and July 2018 at a tertiary university hospital was carried out. Results: Within the study period, 85 patients underwent CDT for AVF thrombosis. Of these patients, 78% underwent CDT for 24 h and 12% required CDT for 48 h. Moreover, 14% of patients had bleeding during CDT and hence required a decrease in dosing or complete cessation. Incidence of intracranial haemorrhage was 1%, and technical success was 92%. Post CDT, primary patency rates at 12, 24 and 36 months were 87%, 62% and 36%, respectively; assisted primary patency rates at 12, 24 and 36 months were 96%, 82% and 69%, respectively; and secondary patency rates at 12, 24 and 36 months were 99%, 93% and 86%, respectively. Multivariate analysis did not identify any predictive factors for patency post CDT. Conclusion: Within our study population, CDT for AVF salvage conferred good technical results with low rates of complications. There was good primary patency at 12 months, and the results were sustained up to 36 months. It remains a useful modality for fistula salvage, avoiding surgical intervention.

Budd-Chiari syndrome: consensus guidance of the Asian Pacific Association for the study of the liver (APASL).

Budd Chiari syndrome (BCS) is a diverse disease with regard to the site of obstruction, the predisposing thrombophilic disorders and clinical presentation across the Asia-Pacific region. The hepatic vein ostial stenosis and short segment thrombosis are common in some parts of Asia-Pacific region, while membranous obstruction of the vena cava is common in some and complete thrombosis of hepatic veins in others. Prevalence of myeloproliferative neoplasms and other thrombophilic disorders in BCS varies from region to region and with different sites of obstruction. This heterogeneity also raises several issues and dilemmas in evaluation and approach to management of a patient with BCS. The opportunity to recanalize hepatic vein in patients with hepatic vein ostial stenosis or inferior vena cava stenting or pasty among those membranous obstruction of the vena cava is a unique opportunity in the Asia-Pacific region to restore hepatic outflow closely mimicking physiology. In order to address these issues arising out of the diversity as well as the unique features in the region, the Asia Pacific Association for Study of Liver has formulated these guidelines for clinicians.

Isolated Systemic Arterial Supply to Normal Lung with Aneurysm Formation: A Rare Entity with An Even Rarer Complication.

BACKGROUND Isolated systemic arterial supply to normal (unsequestered) lung (ISSNL) without associated pulmonary malformation is rare, and lies towards the milder end of the spectrum of congenital lung abnormalities. Aneurysmal dilatation of the anomalous artery is an infrequent complication, with only 5 published cases thus far. CASE REPORT We present the case of a 61-year-old man whose screening chest radiograph showed a retrocardiac mass. Further evaluation with axial imaging demonstrated an ISSNL, complicated by aneurysmal dilatation. The genesis of this condition has been postulated to be due to persistence of primitive aortic branches to the developing lung bud. Initially reported in 1777, this entity is now more accurately classified within the spectrum of pulmonary and bronchovascular abnormalities, with refinement of the latter. The origin of an aberrant artery from the aorta implies that a higher-pressure systemic circulation is being shunted into a lower-pressure pulmonary circulation. While these supplying arteries are known to be large, aneurysmal dilation is exceptionally rare. Here, we review the cases published in the literature and present a case of our own. We aim to describe its pathogenesis, and touch on the classification systems and management. CONCLUSIONS ISSNL is usually first suspected on a screening chest radiograph, as many patients are asymptomatic. Based on contrast-enhanced axial imaging, the diagnosis can be established non-invasively. Definitive management includes surgical and endovascular techniques.

Long Term Survival of Patients Undergoing TIPS in Budd-Chiari Syndrome.

BACKGROUND: There has been significant improvement in understanding the etiology and management of Budd-Chiari Syndrome (BCS). Patients with chronic or acute-on-chronic BCS need radiological interventions in the form of angioplasty, hepatic vein/inferior vena cava stenting or Transjugular Intrahepatic Portosystemic Shunt (TIPS). Data regarding the long term follow up of patients undergoing TIPS is limited. We thus prospectively followed-up BCS patients who underwent TIPS at our center. METHODS: This study included 42 patients with BCS who underwent TIPS with a covered stent between 2004 and 2014. We analyzed the etiology, symptoms, severity, laboratory parameters and imaging pre and post TIPS. All patients underwent surveillance for hepatocellular carcinoma. RESULTS: Patients demographics included 26 males and 16 females with a mean age of 40.5 years (19-68 years). The mean Model for End-Stage Liver Disease score of the entire cohort was 15.38 (range: 9-25). Thirty-four patients were grouped into Rotterdam Class 2 and remaining into Class 3. There was significant improvement in ascites, gastrointestinal bleed, renal function and transaminase levels post TIPS. There were 11 deaths over the follow-up period - 4 within one month, 2 within six months and the rest after 3 years following TIPS. Median duration from clinical presentation to TIPS was 2.1 weeks and median survival till follow-up was 45.5 months (0-130 months). 33/42 patients underwent TIPS prior to 2013, and their median survival till follow-up was 55 months. Six out of eleven deaths that occurred within six months post-TIPS were before 2006; when the technique of TIPS creation was evolving. The cumulative 1 year, 5 years and 10 years OLT-free survival was 86%, 81% and 76%, respectively. Two patients underwent a liver transplant at 4 and 7 years after TIPS. CONCLUSION: Our results validate the role of TIPS in the management of patients with BCS. With the accessibility of TIPS, the requirement for liver transplantation has become rare.

Changing spectrum of Budd-Chiari syndrome in India with special reference to non-surgical treatment.

AIM: To evaluate patterns of obstruction, etiological spectrum and non-surgical treatment in patients with Budd-Chiari syndrome in India. METHODS: Forty-nine consecutive cases of Budd-Chiari syndrome (BCS) were prospectively evaluated. All patients with refractory ascites or deteriorating liver function were, depending on morphology of inferior vena cava (IVC) and/or hepatic vein (HV) obstruction, triaged for radiological intervention, in addition to anticoagulation therapy. Asymptomatic patients, patients with diuretic-responsive ascites and stable liver function, and patients unwilling for surgical intervention were treated symptomatically with anticoagulation. RESULTS: Mean duration of symptoms was 41.5 +/- 11.2 (range = 1-240) mo. HV thrombosis (HVT) was present in 29 (59.1%), IVC thrombosis in eight (16.3%), membranous obstruction of IVC in two (4%) and both IVC-HV thrombosis in 10 (20.4%) cases. Of 35 cases tested for hypercoagulability, 27 (77.1%) were positive for one or more hypercoagulable states. Radiological intervention was technically successful in 37/38 (97.3%): IVC stenting in seven (18.9%), IVC balloon angioplasty in two (5.4%), combined IVC-HV stenting in two (5.4%), HV stenting in 11 (29.7%), transjugular intrahepatic portosystemic shunt (TIPS) in 13 (35.1%) and combined TIPS-IVC stenting in two (5.4%). Complications encountered in follow-up: death in five, re-stenosis of the stent in five (17.1%), hepatic encephalopathy in two and hepatocellular carcinoma in one patient. Of nine patients treated medically, two showed complete resolution of HVT. CONCLUSION: In our series, HVT was the predominant cause of BCS. In the last five years with the availability of sophisticated tests for hypercoagulability, etiologies were defined in 85.7% of cases. Non-surgical management was successful in most cases.

Clinics in diagnostic imaging (176). Acute embolic occlusion of the coeliac artery.

A 52-year-old man, who had a background of chronic heart disease and atrial fibrillation, as well as non-compliance with warfarin therapy, presented with a two-week history of worsening upper abdominal pain. Computed tomography mesenteric angiography showed complete embolic occlusion of the coeliac artery with resultant segmental splenic infarction, and thrombus within the left ventricle. A decision was made to proceed with catheter-directed thrombolysis. Subsequent follow-up angiogram at 12 hours showed successful treatment with complete dissolution of the coeliac embolus. The patient's symptoms resolved during his hospitalisation and he was subsequently discharged well on long-term oral anticoagulation therapy. Isolated acute embolic occlusion of the coeliac axis is a rare occurrence that may result in end-organ infarction. Treatment options include systemic anti-coagulation, mechanical thrombectomy, catheter thrombolysis or open surgery. Catheter-directed thrombolysis therapy is a feasible and effective option for treating acute thromboembolic occlusion of the coeliac artery.

An experience with covered transjugular intrahepatic portosystemic shunt for refractory ascites from western India.

BACKGROUND: In refractory ascites/hydrothorax (RA), uncovered transjugular intrahepatic portosystemic shunt (TIPS) is shown to be superior to large-volume therapeutic paracentesis (LVP) for long-term control of ascites, but at a cost of increased risk of hepatic encephalopathy (HE). Use of covered TIPS has shown to improve shunt patency rate over uncovered TIPS. This retrospective analysis was performed on patients with RA to assess efficacy of TIPS, both covered and uncovered. METHODS: Over 10-year period, patients with RA, patients either required LVP at least 2 times in a month, or were intolerant to LVP, or were unwilling to undergo further LVP, were treated with TIPS (Group-A = 12 patients with uncovered TIPS {Wallstent = 10, Memotherm = 1, SMART = 1}, age = 56.1 +/- 4.5 years, male: female = 5:1; Group-B = 11 patients with e-PTFE-covered TIPS {Viatorr = 11}, age = 55.8 +/- 5.2 years, male: female = 8:3). They were followed-up with clinical and ultrasonography/ Doppler examination every monthly for 3 months and every 3 monthly thereafter (mean = 9.6 +/- 4.2 months). Clinical success (disappearance of ascites at 1-month), technical success (post-TIPS reduction of portosystemic pressure gradient {PPG} < 12 mmHg), appearance of encephalopathy, TIPS-dysfunction (> 50% reduction in flow-velocity, > 50% shunt stenosis or increase in PPG > 12 mmHg in presence of symptoms) and mortality were noted. Data were analyzed using chi-square test and t test. RESULTS: Baseline clinical and biochemical characteristics were similar in both groups. TIPS placement was possible in 11/12 group-A and 11/ 11 group-B patients. Fall in PPG after TIPS was similar in both groups. One patient in group-A was lost followup after the procedure. On comparison of group-A and group-B, clinical success (63.3% and 81.8%), technical success (90.9% and 100%), occurrence of HE (60% and 54.4%) and mortality at 1-year (70% and 63.3%) were not significantly different. TIPS-dysfunction requiring re-intervention was significantly more common in group-A (50%) than group-B (0%). CONCLUSIONS: Covered TIPS was superior to uncovered TIPS, because of less TIPS-dysfunction without increasing chances of HE; but failed to offer any survival advantage.