Rescue of outflow block of the remnant left liver after extended right hemihepatectomy for resection of a tumor in the caudate lobe.

Outflow block of the liver is a life-threatening event after living donor liver transplantation. Herein, we rescued a patient suffering from the outflow block of the remnant left hemiliver caused by bending of the left hepatic vein (LHV) after right hemihepatectomy plus caudate lobectomy combined with resection of the middle hepatic vein (MHV). A metastatic tumor sized 6 cm in the caudate lobe of the liver involving the root of the MHV was found in a 50's year old patient after resection of a right breast cancer eight years ago. Right hemihepatectomy and caudate lobectomy combined with resection of the MHV was performed using a two-stage hepatectomy (partial TIPE ALPPS). On day 1, the total bilirubin value increased to 4.5 mg/dL, and a dynamic computed tomography (CT) scan showed the bent LHV. On the diagnosis of outflow block of the left liver, a self-expandable metallic stent was placed in the LHV using an interventional approach, and the pressure in the LHV decreased from 27 cmH2O to 12 cmH2O. The bilirubin value decreased to 1.2 mg/dL on day 3. Outflow block of the LHV can happen after extended right hemihepatectomy with resection of the MHV. Early diagnosis and interventional stenting treatment can rescue the patient from congestive liver failure.

A case report of limitation of transcatheter hepatic arterial embolization for hereditary hemorrhagic telangiectasia type 2 with pulmonary arterial hypertension.

INTRODUCTION AND IMPORTANCE: Arteriovenous malformations (AVMs) in the liver caused by hereditary hemorrhagic telangiectasia (HHT) influence pulmonary artery hypertension (PAH). Liver transplantation (LT) is the most common treatment for HHT-induced hepatic AVMs. However, LT is contraindicated for patients with severe PAH. There is controversy regarding the ideal therapeutic approach for HHT with PAH and hepatic AVMs. CASE PRESENTATION: We present the case of a 48-year-old female with PAH and HHT. After the initiation of PAH-targeted drugs, we considered that the PAH was mainly caused by high cardiac output secondary to multiple diffuse AVMs in the liver. LT was contraindicated due to high mean pulmonary arterial pressure (mPAP), and we opted to perform transcatheter embolization as an alternative treatment for the AVM. Multiple-stage embolization sessions did not effectively improve the shunt in the liver or the pulmonary hemodynamics. The patient died of an uncontrolled gastrointestinal hemorrhage. CLINICAL DISCUSSION: LT was considered in our case; it was contraindicated because of pulmonary hypertension that was in line with the model for end-stage liver disease exception criteria. Repeated embolization did not reduce the liver shunt or improve pulmonary hemodynamics, possibly due to the diffuse distribution of AVMs in the liver and the rapid development of new collateral vessels with each embolization. Recently, pulmonary vascular resistance (PVR) has been proposed as a more appropriate index for stratifying perioperative risk. CONCLUSION: Based on previous reports and our experience, rapid decision-making regarding LT may be needed based on mPAP and PVR after the initiation of PAH-targeted drugs.

Evaluation of an artificial intelligence U-net algorithm for pulmonary nodule tracking on chest computed tomography images.

OBJECTIVES: To apply image registration in the follow up of lung nodules and verify the feasibility of automatic tracking of lung nodules using an artificial intelligence (AI) method. METHODS: For this retrospective, observational study, patients with pulmonary nodules 5-30 mm in diameter on computed tomography (CT) and who had at least six months follow-up were identified. Two radiologists defined a 'correct' cuboid circumscribing each nodule which was used to judge the success/failure of nodule tracking. An AI algorithm was applied in which a U-net type neural network model was trained to predict the deformation vector field between two examinations. When the estimated position was within a defined cuboid, the AI algorithm was judged a success. RESULTS: In total, 49 lung nodules in 40 patients, with a total of 368 follow-up CT examinations were examined. The success rate for each time evaluation was 94% (345/368) and for 'nodule-by-nodule evaluation' was 78% (38/49). Reasons for a decrease in success rate were related to small nodules and those that decreased in size. CONCLUSION: Automatic tracking of lung nodules is highly feasible.

Intranodal glue embolization for lymphorrhea following inguinal lymphadenectomy in penile cancer: A case report.

An 86-year-old man underwent total penectomy and bilateral inguinal lymphadenectomy (ILND) for penile cancer with an enlarged right inguinal lymph node. The accumulation of 100-150 ml of lymphatic fluid was observed in the right inguinal drain in a day after surgery. Compression was performed, without any improvement in lymphorrhea. During the right inguinal lymphangiography performed on postoperative day (POD) 28, lymphorrhea was still detected. Lymphorrhea was improved 2 days after intranodal glue embolization (IGE) was performed using a mixture of lipiodol and n-butyl-2 cyanoacrylate (NBCA). IGE was effective for intractable lymphorrhea after ILND in penile cancer.

An Update of Treatment of Pancreatic Arteriovenous Malformations.

Pancreatic arteriovenous malformation is a rare entity (0.9%). There are about 200 articles available in PubMed. This review article includes 86 published articles, with 117 cases published after 2000. The median age at diagnosis was 51, and most of the patients were male (87.0%). The symptoms included pain, bleeding, pancreatitis, ulcers in the duodenum or stomach, varix formation, jaundice, and ascites. The diagnostic modalities were angiography, contrast-enhanced CT, MRI, and/or Ultra Sound. The most common treatments were surgery and embolization. The clinical success rate of embolization reported was 57.7%. The tailored embolization based on each agio-architecture had a clinical success rate of 80%. If embolic therapy is ineffective, surgical intervention should be considered.

The compatibility experiment: which microcoils are not suitable for which microcatheters?

INTRODUCTION: Microcatheters and microcoils are produced by a number of different companies, and this is one of the reasons that their compatibility is sometimes unclear. Therefore, we conducted an experimental study to evaluate the compatibility of microcoils through major microcatheters using an in vitro model. MATERIAL AND METHODS: We performed trials on eight types of microcoils with 16 types of microcatheters in a vascular model under fluoroscopy. The microcatheters were perfused with normal saline and the vascular model with normal saline with lubricant during the experiment. Two radiologists evaluated their compatibility with scores of 1 through 5 in a double-blinded state (1: not passable, 2: passable with exertion, 3: passable with some resistance, 4: passable with slight resistance, and 5: passed without resistance). RESULT: A total of 512 combinations were examined. The number of scores with 5, 4, 3, 2, and 1 were found for 465, 11, 3, 2, and 15 combinations, respectively. Sixteen combinations were non-applicable due to the depletion of microcoils. CONCLUSION: Although this experiment has multiple limitations, most microcoils and microcatheters are compatible if their primary diameters are smaller than the indicated microcatheter tip inner diameters, with some exceptions.

Development and performance evaluation of a deep learning lung nodule detection system.

BACKGROUND: Lung cancer is the leading cause of cancer-related deaths throughout the world. Chest computed tomography (CT) is now widely used in the screening and diagnosis of lung cancer due to its effectiveness. Radiologists must identify each small nodule shadow from 3D volume images, which is very burdensome and often results in missed nodules. To address these challenges, we developed a computer-aided detection (CAD) system that automatically detects lung nodules in CT images. METHODS: A total of 1997 chest CT scans were collected for algorithm development. The algorithm was designed using deep learning technology. In addition to evaluating detection performance on various public datasets, its robustness to changes in radiation dose was assessed by a phantom study. To investigate the clinical usefulness of the CAD system, a reader study was conducted with 10 doctors, including inexperienced and expert readers. This study investigated whether the use of the CAD as a second reader could prevent nodular lesions in lungs that require follow-up examinations from being overlooked. Analysis was performed using the Jackknife Free-Response Receiver-Operating Characteristic (JAFROC). RESULTS: The CAD system achieved sensitivity of 0.98/0.96 at 3.1/7.25 false positives per case on two public datasets. Sensitivity did not change within the range of practical doses for a study using a phantom. A second reader study showed that the use of this system significantly improved the detection ability of nodules that could be picked up clinically (p = 0.026). CONCLUSIONS: We developed a deep learning-based CAD system that is robust to imaging conditions. Using this system as a second reader increased detection performance.

A technique for creating an experimental type Ia endoleak model in the thoracic aorta of swine.

PURPOSE: This study aimed to create an animal model of type Ia endoleak that creates persistent problems after thoracic endovascular aortic repair. MATERIALS AND METHODS: In six swine, thoracic aortic aneurysms were created using the harvested jugular vein. We created a type Ia endoleak using a composite stent-graft comprising the first stent-graft (reverse-tapered: thicker part, 16 mm; thinner part, 10 mm) and the second stent-graft (tapered: thicker part, 18-20 mm; thinner part, 16 mm). This double-component stent-graft was deployed in the abdominal aorta and then moved upward to the proximal entry site of the thoracic aneurysm using the inflated balloon for precise positioning. After the surgical procedure and on postoperative day 8, aortography was performed to detect residual endoleak, and then the swine were euthanized. RESULTS: A stable aneurysm (mean size of all aneurysms, 16.8 ± 1.72 mm × 11.8 ± 2.32 mm) and type Ia endoleak were successfully observed in all swine. A single stent-graft was sufficient in one of the six swine. CONCLUSION: A novel technique to create a type Ia endoleak model can be successfully developed in swine.

New technique for false lumen coiling of spontaneous isolated superior mesenteric artery dissection.

BACKGROUND: Spontaneous isolated visceral artery dissection is rarely encountered. Endovascular intervention with good outcomes has become popular for patients with persistent symptoms or developing ischemia. We could perform life-saving treatment for a spontaneous isolated superior mesenteric artery dissection with a unique endovascular intervention. CASE PRESENTATION: We describe the case of an 80-year-old man who presented with acute abdominal pain and a spontaneous isolated superior mesenteric artery dissection measuring 35 mm in major diameter and 6.6 mm in minor diameter on abdominal contrast-enhanced computed tomography. After admission, abdominal pain was progressive, and a repeated scan revealed progression of the dissection. As an endovascular intervention, via the bilateral femoral approach, detachable coils were placed in the false lumen of the superior mesenteric artery dissection through the false lumen under the micro-balloon occlusion at the point of re-entry and entry through the true lumen to prevent coil migration. Technical and clinical success was achieved without serious adverse events. CONCLUSION: Coil embolization using micro-balloon assistance combined with the double-catheter technique for a large entry and re-entry false lumen of a spontaneous isolated superior mesenteric artery dissection was useful and feasible.

Supplement of Clinical Practice Guidelines for Endovenous Thermal Ablation for Varicose Veins: Overuse for the Inappropriate Indication.

While endovenous thermal ablation (ETA) become first choice of treatment for varicose veins, overuse of ETA for the inappropriate indication is growing problem. ETA is performed not only on varicose cases without symptom but also non diseased cases with segmental reflux of saphenous veins or no reflux. Indications of ETA was demonstrated in "the Clinical Practice Guidelines for ETA for Varicose Veins 2019" by Japanese Society of Phlebology. Purpose of this supplement is description of basics of correct indication for ETA. We also demonstrate the typical case of overuse of ETA for wrong indication. (This is a translation of Jpn J Phlebol 2020; 31: 39-43.).

Evaluation of a Monte Carlo-based algorithm for the influence of totally implantable venous access ports in external radiation therapy.

PURPOSE: This study aimed to assess whether a Monte Carlo (MC)-based algorithm reflects the influence of totally implantable venous access ports (TIVAPs) in external radiation therapy. MATERIALS AND METHODS: The present study comprised two steps: experimental measurements of depth doses and surface doses with and without TIVAPs and calculation with an MC-based algorithm. RESULTS: The TIVAP-associated maximum dose reduction compared with the dose at the same depths without TIVAPs was 7.8% at 4 MV, 6.9% at 6 MV, and 5.7% at 10 MV in measurement, and 7.4% at 4 MV, 6.6% at 6 MV, and 5.5% at 10 MV in calculation. Relative surface doses were higher with TIVAPs made of titanium, due to a higher fluence of backscattered electrons from the TIVAPs, than with plastic TIVAPs. There were no significant differences in the relative differences between the measured and calculated doses of the titanium TIVAP group and the plastic TIVAP group at 4 MV (p = 0.99), 6 MV (p = 0.67), and 10 MV (p = 0.54). CONCLUSION: TIVAPs caused target dose reductions and dose increase near the TIVAP, especially when made of titanium. The influences are reflected in the MC-based algorithm.

Late clinical outcomes of manual aspiration thrombectomy for a massive acute pulmonary thromboembolism.

PURPOSE: We investigated the late outcomes of patients who underwent manual aspiration thrombectomy for acute massive pulmonary thromboembolism. MATERIALS AND METHODS: Fifteen patients underwent manual aspiration thrombectomy between December 1995 and June 2002. All patients were discharged after the procedure. Patients' statuses were checked by medical record examinations and telephone interviews. The median follow-up was 162 months (116-208 months). RESULTS: Five patients died during follow-up; two for malignancy, one for septic shock, one for cerebral infarction, and in one patient the cause of death was unknown. There were no pulmonary thromboembolism-related deaths during the period and no recurrence. The 1-year survival rate was 100%, the 5-year survival rate was 75.0 ± 12.5%, and the 10-year survival rate was 75.0 ± 12.5%. CONCLUSION: Patients who undergo manual aspiration thrombectomy for acute massive pulmonary thromboembolism show acceptable outcomes.

Late Clinical Outcomes of Hybrid Catheter Intervention for Acute Massive Pulmonary Thromboembolism.

PURPOSE: We aimed to investigate the long-term outcomes of patients undergoing hybrid catheter intervention for acute massive pulmonary thromboembolism. MATERIAL AND METHODS: Twenty-five patients with hemodynamic impairment were treated with mechanical thrombus fragmentation, an intrapulmonary injection of mt-PA, and manual clot aspiration between August 1999 and June 2002. All patients were discharged after the procedure. Patients' statuses were checked by medical record examinations and telephone interviews. The median follow-up was 141 months (115-168 months). RESULTS: Ten patients died during follow-up, five for malignancy, three for septic shock, one for cerebral infarction, and one for heart failure. One patient had recurrence of pulmonary thromboembolism because of drug withdrawal by self-judgment. No chronic pulmonary thromboembolism was observed. The 1-year, 5-year, and 10-year survival rates were 87.5 ±6.8%, 83.3±7.6%, and 74.5±9.0%, respectively. CONCLUSION: Patients who undergo hybrid catheter intervention for acute massive pulmonary thromboembolism show good long-term outcomes.

An Extremely Rare Complication: Abdominal Aortic Aneurysm Rupture Caused by Migration of a Zenith Main Body Years After Repair of the Suprarenal Stent Separation.

PURPOSE: To report an unusual case of an abdominal aortic aneurysm (AAA) rupture caused by migration of a Zenith stent-graft main body years after its separation from the suprarenal stent. CASE REPORT: A 72-year-old man underwent endovascular aneurysm repair with a Zenith stent-graft for an infrarenal AAA in year 2000. At that time, a femorofemoral bypass was performed because the left external iliac and common femoral arteries were dissected during treatment. In 2013, follow-up computed tomography (CT) showed disconnection of the uncovered proximal stent, which led to a type Ia endoleak. An additional Zenith main body and Large Palmaz XL balloon-expandable stent were deployed; the endoleak disappeared. In 2016, the patient had abdominal pain, and emergency CT showed AAA rupture caused by migration of the first main body deployed in 2000 under the distal edge of the contralateral (left) leg of the additional main body from 2013, which led to a type IIIa endoleak between the 2 main bodies. A converter and iliac legs were deployed to successfully seal the type IIIa endoleak. The patient remains well 18 months after the second repair; CT scans document stable stent-grafts and no endoleak. CONCLUSION: Physicians should be aware of the potential risk for AAA rupture caused by late main body migration after treatment for suprarenal stent separation from a Zenith stent-graft.

Strategy for the treatment of spontaneous isolated visceral artery dissection.

OBJECTIVES: To determine the incidence of rare spontaneous isolated visceral artery dissection (SIVAD), characterize its pathogenesis, and suggest treatment strategies. MATERIALS AND METHODS: We reviewed abdominal contrast-enhanced computed-tomography (CE-CT) scans from January 2005 to December 2016 retrospectively in our institution, identified 47 SIVAD patients and classified them into a symptomatic (n = 22) or asymptomatic group (n = 25). Further, we classified the five types based on the CE-CT images. Patient characteristics, incidence, vascular risk factors, complications, symptoms, treatments outcomes, and morphology features on CE-CT images were analyzed. RESULTS: SIVAD was seen on 0.09% of all abdominal CE-CT scans, and 0.68% of all abdominal CT-CT scans obtained for the evaluation of acute abdominal symptoms. The asymptomatic group had significantly fewer patients with periarterial fat stranding or branch vessel involvement on CE-CT images (p < 0.01). The mean length of the dissection was longer in the symptomatic group (p < 0.05). In the asymptomatic group, dissection-related abdominal symptoms and complications did not develop; followed-up CE-CT scans showed improvement in the dissection lesions in 1 (4.0%) patient, no changes in 22 (88.0%), and complete remodeling in 2 (8.0%). In the symptomatic group, one patient presented with organ ischemia at diagnosis and five patients developed organ ischemia underwent endovascular intervention. In the remaining 16 patients received nonoperative intervention only, followed-up CE-CT scans showed improvement in 13 (86.7%), and complete remodeling in 2 (13.3%). CONCLUSIONS: Symptomatic SIVAD patients should be hospitalized because some of those may experience organ ischemia or aneurysm formation. Endovascular intervention is a feasible treatment for complications of SIVAD.

Ultrashort-Segment Embolization of High-Flow Vessels Using a Coil Packing Technique in an Amplatzer Vascular Plug.

PURPOSE: To report an experimental study and clinical case using a coil packing technique that hastens occlusion of an Amplatzer Vascular Plug 1 (AVP1) in short-segment embolization of high-flow target vessels. TECHNIQUE: An experimental vascular stenosis model was made of 12-mm soft polyvinyl chloride tubing. Under continuous pulsatile flow, a 12-mm AVP1 was deployed in the 4-mm-diameter stenosis. Before detachment of the AVP1, a 2.2-F microcatheter was inserted into the AVP1 through its mesh via a 6-F delivery guiding sheath in parallel with the delivery wire. Hydrogel microcoils were deployed tightly in the AVP1 and the plug was detached. After the procedure, the pulsatile saline flow was nearly obliterated. In the first clinical case, a 64-year-old man with a thoracic aortic stent-graft and single vessel debranching for type B aortic dissection developed a residual type II endoleak via the left subclavian artery. This coil packing technique in an AVP1 was employed to successfully embolize the leak. CONCLUSION: Based on the experimental study and the first experience in vivo, tight coil packing of an AVP1 might be a robust technique for ultrashort-segment embolization.

Coil embolization using microballoon assistance combined with the double-catheter technique for a large superior mesenteric arterial pseudoaneurysm and fistula secondary to acute pancreatitis.

Pseudoaneurysm of the superior mesenteric artery (SMA) is rare and associated with the risk of massive fatal hemorrhage and acute mesenteric ischemia. We describe a 43-year-old man with acute pancreatitis who presented with an SMA pseudoaneurysm measuring 13 × 12 cm in diameter. The pseudoaneurysm originated between the first and second jejunal arteries and drained into the mesenteric vein. The SMA trunk between the first and second jejunal arteries was embolized with detachable coils using microballoon assistance. After coil placement, arteriography showed the collateral circulation and no perfusion delay of the distal SMA. This technique was useful for isolation of the SMA pseudoaneurysm.

Evaluating the Feasibility of Isolated Pancreatic Perfusion for Chemotherapy Using Computed Tomography: An Experimental Study in Pig Models.

PURPOSE: Percutaneous isolated pancreatic perfusion (PIPP) is performed along with interventional radiology techniques to obtain high drug concentration by occluding the arterial inlet and venous outlet of the pancreas. The experimental study aimed to evaluate the contrast distribution in PIPP under different flow rates with or without anterior mesenteric artery (AMA) occlusion. MATERIALS AND METHODS: This study was approved by a local animal experiment ethics committee. Nine pigs were divided into Groups 1, 2, and 3, by infusion rates of 12, 24, and 36 mL/min. Groups 4 and 5 (3 pigs each) and Group 6 (2 pigs) underwent PIPP at the same respective infusion rates with and without AMA occlusion. Computed tomography (CT) arteriography was performed during PIPP with nonionic contrast media. The enhanced volume was calculated by adding the enhanced area in each slice using 1.25-mm axial images. The percent enhanced volume to the whole pancreas (%eV) was used to simulate drug distribution; the result was compared among groups. RESULTS: Without AMA occlusion, a larger %eV was obtained with high infusion rates (P = 0.039). The median %eV in Groups 1, 2, and 3 were 57.7, 74.2, and 90.5%, respectively. With AMA occlusion, CT demonstrated duodenal enhancement at an infusion rate of 36 mL/min, and the median %eV in Groups 4, 5, and 6 were 92.8, 95.4, and 98.5%, respectively. A significantly larger %eV was obtained after AMA occlusion (P = 0.031). CONCLUSION: A higher infusion rate or AMA occlusion increases the enhanced volume in PIPP in pig models. LEVEL OF EVIDENCE: No level of evidence.

Novel treatment strategy for advanced hepatocellular carcinoma: combination of conventional transcatheter arterial chemoembolization and modified method with portal vein occlusion for cases with arterioportal shunt: a preliminary study.

Background A novel strategy to combine conventional transcatheter arterial chemoembolization (TACE) and TACE during portal vein occlusion (TACE-PVO) in the presence of high-flow arterioportal shunt (APS) has been developed to treat hepatocellular carcinoma (HCC) with portal invasion. Purpose To evaluate the efficacy of this strategy. Material and Methods Twenty-five cases of HCC with portal invasion, treated between April 2006 and December 2015, were evaluated. Balloon occlusion of the portal venous outlet was performed in eight cases of high-flow APS when performing TACE. Conventional TACE was performed in the other 17 cases. The primary endpoint was overall survival. Adverse events and deterioration of liver function were also evaluated. Results The median survival time (MST) was 12 months. One-, two-, and three-year survival rates were 48.0%, 39.3%, and 26.2%, respectively. Subgroup analysis and multivariate analysis revealed the CLIP score as prognostic factor. MST was 2.5 months in the subgroup with CLIP score ≥4 and 26.0 months in the subgroup with CLIP score ≤3 (hazard ratio = 7.7, 95% confidence interval = 2.3-25.8). Transient elevations of the levels of transaminase and bilirubin were observed; however, deterioration of liver function was infrequent; upgrading of Child-Pugh class in 9.1% of cases. Conclusion A novel strategy, combining conventional TACE and TACE-PVO, is effective for HCC with portal invasion. The CLIP score may be useful for considering treatment indication.