The Guidelines for Percutaneous Transhepatic Portal Vein Embolization: English Version

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

Efficacy of Subtraction Computed Tomography Arteriography During Preoperative Embolization in Spinal Tumors

Background

This study aimed to evaluate the efficacy of subtraction computed tomography arteriography (s-CTA) during preoperative embolization in spinal tumors.

Methods

The study analyzed 17 vertebrae in 13 patients who underwent preoperative embolization before spinal fixation surgery for malignant spinal tumors to decrease blood loss at our hospital from 2019 to 2021. Their ages ranged from 56 to 88 years (average, 73.5 years). Metastatic bone tumors were most common, including five cases originating as lung carcinomas and three as renal cancers. After digital subtraction angiography of selected tumor-feeding arteries and non-subtraction CTA (ns-CTA) were performed, s-CTA was conducted using data obtained from both procedures. A clarity score of the boundary between the normal bone and tumor was derived for each patient, which was then classified into four grades (good, 3 points; fair, 2 points; faint, 1 point; poor, 0 points) by two experienced radiologists, followed by a comparison between the s-CTA and ns-CTA groups using the Wilcoxon signed-rank test.

Results

Clarity scores were significantly higher in the s-CTA group than in the ns-CTA group (P < 0.001). The agreement of Cohen's coefficients between the two radiologists was κ = 0.724 in s-CTA scoring and κ = 0.622 in ns-CTA scoring, which were moderately matched. Seven arteries were not embolized due to insufficient tumor contrast enhancement and their poor relation to the surgical invasion zone. No complications were observed during or after embolization.

Conclusion

S-CTA successfully distinguished between tumor and normal bone and may help avoid unnecessary embolization.

Hepatectomy for massive hepatic necrosis after transcatheter arterial embolization hemostasis for hepatic hemorrhage following hepatic trauma: A case report

Key Clinical Message

Although partial hepatic necrosis often occurs following endovascular treatment for bleeding associated with hepatic trauma, it is relatively rare that additional treatment is required. However, invasive procedures such as hepatic resection should sometimes be considered when infection occurs over massive hepatic necrosis.

Abstract

Although partial hepatic necrosis following endovascular treatment for bleeding associated with hepatic trauma is occasionally experienced, it is relatively rare for the necrotic area of the liver to require additional treatment. However, invasive procedures such as hepatic resection should sometimes be considered when infection occurs over massive hepatic necrosis.

Percutaneous ethanolamine oleate sclerotherapy for aggressive vertebral hemangioma: A case report

Vertebral hemangiomas are the most common benign lesion of the spine which are often an asymptomatic incidental finding. However, a few hemangiomas are aggressive and characterized by bone expansion and extraosseous extension into the paraspinal and epidural spaces. We report the case of a patient presenting an aggressive vertebral hemangioma causing back pain and bilateral numbness of the legs. Among various treatment modalities, a minimally invasive percutaneous sclerotherapy procedure using ethanolamine oleate under computed tomography and fluoroscopic guidance was safely and successfully performed with good clinical outcomes.

Role of Aggressive Aneurysm Sac Embolization Before Endovascular Abdominal Aneurysm Repair in Preventing Type II Endoleak and Sac Expansion

Background

This study aimed to evaluate the effect of aggressive embolization of side branches arising from the aneurysmal sac before endovascular aneurysm repair.

Methods

This retrospective study included 95 patients who underwent endovascular infrarenal abdominal aortic aneurysm repair at Tottori University Hospital between October 2016 and January 2021. Of these, 54 underwent standard endovascular aneurysm repair (conventional group), and 41 underwent coiling of the inferior mesenteric and lumbar arteries before undergoing endovascular aneurysm repair (embolization group). The occurrence of type II endoleak, change in aneurysmal sac diameter, and reintervention rate due to type II endoleak during follow-up were evaluated.

Results

Compared to the conventional group, the embolization group had a significantly lower incidence of type II endoleak, more frequent aneurysmal sac shrinkage, and lower aneurysmal sac growth related to type II endoleak.

Conclusion

Our results demonstrated the effectiveness of aggressive aneurysmal sac embolization before endovascular aneurysm repair to prevent type II endoleak and the consequent long-term aneurysmal sac enlargement.

A Case of Esophagojejunal Variceal Rupture after Total Gastrectomy and Esophagojejunostomy Successfully Treated with Percutaneous Transhepatic Obliteration under Dual-balloon Occlusion of Feeding and Draining Veins

We present the case of a man in his 60s with bleeding esophagojejunal varices occurring after gastrectomy for gastric carcinoma. Percutaneous transhepatic portography depicted the esophagojejunal varices originated from the jejunal vein and drained into the azygos vein. A 5-French occlusion balloon catheter was wedged into the jejunal vein and a 3-French occlusion balloon catheter into one drainage channel of the esophagojejunal varices via the azygos vein. Selective antegrade jejunal venography under dual-balloon occlusion revealed entire esophagojejunal varices with good stagnated and well-opacified contrast medium. Subsequently, 12 mL of 5% ethanolamine oleate-contrast medium mixture was slowly injected into the esophagojejunal varices. He was discharged without complications one week after the procedure, and abdominal computed tomography demonstrated the disappearance of the esophagojejunal varices six months after the procedure.

Coil-assisted retrograde transvenous obliteration of gastric varices by an inverted catheter tip technique via the pericardiophrenic vein

A 70-year-old woman with liver cirrhosis was admitted to our hospital for treatment of growing gastric varices in the fundus. Computed tomography showed gastric varices continuously draining the pericardiophrenic vein via the inferior phrenic vein. Balloon-occluded retrograde transvenous obliteration by a transjugular approach was planned. However, a conventional balloon catheter or microballoon catheter could not be inserted into the efferent vein near the varices because of the narrowness and tortuosity of the vein. Hence, coil-assisted retrograde transvenous obliteration was performed by an inverted catheter tip technique using a single conventional microcatheter. This technique might be useful for cases in which it is difficult to insert a balloon catheter into the efferent vein.

A rare case of sigmoid colon cancer in which the lower limbs received collateral blood flow from the inferior mesenteric artery owing to peripheral artery disease

Background

Colorectal cancer and peripheral artery disease are common conditions in older adults and may coexist in this population. Lymph node dissection along the inferior mesenteric artery is a vital procedure in cases of left-sided colorectal cancer. However, the inferior mesenteric artery may show a collateral blood pathway in rare cases of peripheral artery disease. We report a case of advanced sigmoid colon cancer in which the lower limbs received inferior mesenteric artery flow owing to asymptomatic peripheral artery disease. The possibility of catastrophic lower-limb ischemia because of complete mesenteric excision with ligation of the inferior mesenteric artery was a matter of concern in this case.

Case presentation

A 73-year-old man with asymptomatic peripheral artery disease was diagnosed with stage IIIB advanced sigmoid colon cancer. Angiography using a balloon-occlusion catheter revealed that his lower limbs received prominent inferior mesenteric artery blood flow through a collateral pathway. Therefore, interventional radiologists and cardiovascular surgeons evaluated the indications for endovascular stents or bypass grafts. The patient also had dilated cardiomyopathy, so the cardiovascular physicians evaluated his tolerance in the worst-case scenario of a colorectal anastomotic leak. The patient underwent axillofemoral artery bypass and two-stage laparoscopic sigmoid colectomy without anastomosis. The postoperative course was uneventful, and he resumed his job within a month after the resection.

Conclusions

Although collateral flow from the inferior mesenteric artery is rare in patients with peripheral artery disease, a few case reports have described fatal lower-limb ischemia following anterior resection. The perioperative multidisciplinary evaluation enabled us to understand the patient’s condition and risks, and allowed successful cancer treatment without ischemia of the lower limbs.

Successful Interventional Radiology for Acute Median Arcuate Ligament Syndrome After Pancreaticoduodenectomy

Background: Median arcuate ligament (MAL) syndrome (MALS), also known as celiac artery (CA) compression syndrome and Dunbar syndrome, occurs because of extraluminal compression of the CA root by the MAL, which is part of the diaphragm. In MALS, a malposition of the MAL compresses the CA and causes nonspecific symptoms, including epigastric pain after eating, weight loss, nausea, and vomiting and can sometimes cause visceral aneurysms. Typically, in MALS, various chronic ischemic symptoms and visceral aneurysms due to changes in arterial blood flow are observed; however, in acute-onset MALS, acute organ failure due to ischemic changes may be problematic. Surgical treatment is the recommended treatment for MALS, but the optimal treatment of acute MALS that occurs after laparotomy remains controversial because of its rarity. Here, we present the first case of acute MALS, which occurred after pancreaticoduodenectomy (PD) that was successfully treated with interventional radiology (IVR) without reoperation.

Case presentation: A 75-year-old man presented with liver infarction after subtotal stomach-preserving PD using the Child method plus Braun enteroenterostomy. As a result of contrast-enhanced computed tomography for the investigation of elevated hepatic cytolysis-related enzymes on the first postoperative day, he was diagnosed with acute MALS resulting from gastrointestinal reconstruction after PD. The patient underwent IVR to restore blood flow of the CA, and an intraluminal stent was inserted. Despite the development of ischemic gastropathy, splenic infarction, and pancreatic fistula, the patient was eventually discharged on postoperative day 82 without any disability.

Conclusion: Many studies have reported open, laparoscopic, and robot-assisted MAL incisions for MALS, but few reports have detailed the treatment for postoperative MALS. Here, we report the first case of acute MALS developed after PD that was successfully treated with endovascular CA stenting. For acute MALS after PD, early endovascular treatment may be more useful than re-laparotomy.

Adaptive statistical iterative reconstruction for computed tomography of the spine

INTRODUCTION

The utility of evaluating a sagittal view of CT of the spine is well-known. In many clinical cases, the sagittal view includes noise generated from surrounding objects and may degrade the image quality. Iterative reconstruction (IR) techniques are useful for noise reduction; however, they can reduce spatial resolution. The aim of this study was to evaluate the effectiveness of the adaptive statistical iterative reconstruction (ASiR) for generating sagittal CT images of the spine when compared to filtered back projection (FBP).

METHODS

The image quality of clinical images from 25 patients were subjectively assessed. Three radiologists rated spatial resolution, image noise, and overall image quality using a five-point scale. For objective assessment, z-direction modulation transfer function (z-MTF) was measured using a custom-made phantom. Additionally, z-axis noise power spectrum (z-NPS) was measured using a water phantom. An improved adaptive statistical iterative reconstruction algorithm called ASiR-V was used in this study. Blending levels were 50%, and 100% (ASiR-V50, ASiR-V100, respectively).

RESULTS

For subjective assessments, images using ASiR-V100 were determined to have the best overall image quality, despite having received the worst score in the assessment of spatial resolution. For objective assessments, the image using ASiR-V50 and ASiR-V100 curves were slightly degraded in terms of low contrast z-MTF when compared to FBP.

CONCLUSION

ASiR-V was effective to improve the image quality when compared with FBP when reviewing sagittal reformats of the spine.

IMPLICATIONS FOR PRACTICE

This study suggests that high resolution is not the only thing that is key when reviewing sagittal CT spinal reformats. Such images should be provided as part of routine CT spine protocols, where available.

Treatment of pulmonary arteriovenous malformations: clinical experience using different embolization strategies

PURPOSE

To evaluate embolization efficacy of pulmonary arteriovenous malformations (PAVM) using Amplatzer vascular plugs (AVP) and coils.

MATERIALS AND METHODS

Eighty-eight embolized simple PAVMs in 38 patients were retrospectively analyzed by follow-up CT. Mean age was 50.2 ± 15.6 years and 22 (57.9%) patients were females. Mean follow-up interval was 38.2 ± 28.4 months (median 29.9 months). Embolization devices included AVP I, AVP II, AVP 4, and coils. Technical success was defined as no visualization of an early draining vein at angiography after embolization. Treatment success was defined as complete disappearance or decrease in size of the venous aneurysm ≥ 70% at follow-up CT.

RESULTS

Technical success rate was 100% and treatment success rate evaluated by CT for the various embolization strategies was 100% for AVP I (n = 6), 100% for AVP I + coils (n = 5), 83.3% for AVP II (n = 6), 40.0% for AVP II + coils (n = 5), 87.5% for AVP 4 (n = 8), 50.0% for AVP 4 + coils (n = 8), and 78.0% for coils alone (n = 50). No statistically significant difference in embolization efficacy was seen between different devices (P = 0.083). Although not statistically significant, combination use of coils with AVPs demonstrated lower rates of clinical embolization success (P = 0.053).

CONCLUSION

Embolization of PAVMs demonstrated high technical and treatment success rates with available embolic devices. No significant statistical differences were demonstrated between AVPs. However, the need for both coils and AVPs may suggest a more complicated underlying lesion at risk for recurrence.

Safety and Risk of Superselective Transcatheter Arterial Embolization for Acute Lower Gastrointestinal Hemorrhage with N-Butyl Cyanoacrylate: Angiographic and Colonoscopic Evaluation

PURPOSE

To retrospectively evaluate the safety and risk of transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) for urgent acute arterial bleeding control in the lower gastrointestinal tract by angiography and colonoscopy.

MATERIALS AND METHODS

NBCA TAE was performed in 16 patients (mean age, 63.7 y) with lower gastrointestinal bleeding (diverticular hemorrhage, tumor bleeding, and intestinal tuberculosis). Angiographic evaluation was performed by counting the vasa recta filled with casts of NBCA and ethiodized oil (Lipiodol) after TAE. Patients were classified as follows: group Ia, with a single vas rectum with embolization of 1 branch (n = 6); group Ib, with a single vas rectum with embolization of ≥ 2 branches (n = 8); group II, with embolization of multiple vasa recta (n = 2). All patients underwent colonoscopy within 1 month, and ischemic complications (ulcer, scar, mucosal swelling, fibrinopurulent debris, and necrosis) were evaluated.

RESULTS

The procedure was successful in all patients. No ischemic change was observed in any patients in group Ia and in two patients in group Ib. Ischemic changes were observed in six group Ib patients and both group II patients. Group Ib patients experienced ischemic complications that improved without treatment. One patient in group II underwent resection for intestinal perforation after embolization of three vasa recta. One patient in group II with sigmoid stricture with embolization of six vasa recta required prolonged hospitalization.

CONCLUSIONS

NBCA embolization of ≥ 3 vasa recta can induce ischemic bowel damage requiring treatment. NBCA TAE of one vas rectum with ≥ 2 branches could also induce ischemic complications. However, these were silent and self-limited.

Influence of ethanol-induced pulmonary embolism on hemodynamics in pigs

AIMS AND OBJECTIVES

Ethanol is widely used for the embolization treatment of vascular malformations, but it can also cause serious complications such us pulmonary hypertension, cardiopulmonary collapse and death. The complications are considered secondary to pulmonary vasospasm and ethanol-induced sludge embolism, etc., We studied the hemodynamic effects of intravenous absolute ethanol injection and ethanol sludge injection in pigs.

MATERIALS AND METHODS

A total of 5 pigs underwent intravenous injection of ex vivo generated ethanol-induced sludge in which residual ethanol was removed (Group S) and 4 pigs underwent intravenous injection of absolute ethanol (Group E). Hemodynamic parameters related to the pulmonary and systemic circulation were compared between the groups.

RESULTS

Transient pulmonary hypertension was observed in both groups and the hemodynamic changes were similar in both groups.

CONCLUSIONS

Sludge can induce transient pulmonary hypertension or cardiopulmonary collapse, without ethanol and may be the mechanism by which ethanol induces its adverse hemodynamic effects.

Transcatheter arterial embolization of acute arterial bleeding in the upper and lower gastrointestinal tract with N-butyl-2-cyanoacrylate

PURPOSE

To assess the clinical utility and safety of transcatheter arterial embolization with N-butyl-2-cyanoacrylate (NBCA) for urgent control of acute arterial bleeding in the upper and lower gastrointestinal tract.

MATERIALS AND METHODS

Therapeutic NBCA embolization was performed in 37 patients (39 cases; mean age, 67.8 years) with acute upper (n = 16) or lower (n = 23) gastrointestinal tract bleeding after endoscopic management had failed. Transcatheter arterial embolization was performed using 1:1 to 1:5 mixtures of NBCA and iodized oil. The most common etiologies of bleeding were colonic diverticulosis (n = 13), malignancy (n = 11), and benign ulcer (n = 7). Coagulopathy was present in 11 patients, and 23 patients were hemodynamically unstable before NBCA embolization. Histologic examination for bowel ischemia was also performed in five patients who underwent excision of the lesion after NBCA embolization.

RESULTS

The technical success rate was 100%. Recurrent bleeding occurred in two patients. Complete hemostasis was achieved in all 11 patients with coagulopathy. Ulcers induced by transcatheter arterial embolization were noted in 6 of 20 patients who underwent endoscopic examination; the ulcers were successfully treated with conservative measures. Histologic examination revealed that despite inflammatory reactions in and around the vessels, no intestinal necrosis secondary to NBCA embolization was found. Hepatic abscess occurred in two cases, and ischemia of the lower limb occurred in one case; these complications were managed by percutaneous drainage and bypass surgery.

CONCLUSIONS

Transcatheter arterial embolization with NBCA is a good treatment option with a high rate of complete hemostasis and a low recurrent bleeding rate, even in patients with coagulopathy.

Successful closure of intractable tracheoesophageal fistula using a combination of a modified silicon stent and metallic stents

Although surgery is the usual management strategy for acquired benign tracheoesophageal fistula, sometimes this approach is contraindicated or the patient declines surgical management. In this report, we describe a case of a patient with tracheoesophageal fistula at the level of the carina due to bronchial arterial infusion chemotherapy. Closure could not be achieved in response to multiple treatment strategies, including airway stenting, esophageal stenting, occlusion with microcoils, or cyanoacrylate glue. We subsequently achieved closure of this fistula through the combination of a modified silicon stent and metallic stents.

Very Wide-Gap and Device-Quality a-Si:H from Highly H2 Diluted SiH4 Plasma Decomposed by High RF Power

The H2 dilution technique at a high deposition rate (RD) was investigated by depositing hydrogenated amorphous silicon (a-Si:H) under a high if power density of 750 mW/cm2, which is 20 times as large as that of conventional conditions. It was found that the H2 dilution ratio γ ( = [H2 gas flow rate] / [SiH4 gas flow rate]) tendency of the film properties, such as the H content (CH), optical gap (Eopt), SiH2/SiH and photoconductivity (σph) of a-Si:H is different for the high rf power (750 mW/cm2) and the medium rf power (75 mW/cm2) conditions. Under medium rf power, the CH, Eopt and SiH2/SiH decrease as γ increases. Under the high if power, on the contrary, the CH and Eopt, monotonously increase while maintaining a low SiH2/SiH and a high σph of 10-6 S/cm as γ increases. These results suggest that increasing the rf power enhances the H incorporation reactions due to H2 dilution. It is thought that a high rf power causes the depletion of SiH4 and hence the extinction of H radicals, expressed by SiH4 + H* → SiH3* + H2, is suppressed. A high H radical density enhances the incorporation of H into a-Si:H, resulting in very wide-gap a-Si:H with a high CH, Consequently, very wide-gap a-Si:H with device-quality (Eopt of 1.82 eV with an (αhv)1/3 plot, corresponding to > 2.1 eV with Tauc's plot, and σph of 10-6 S/cm) can be obtained at a high RD of 12 Å/s without carbon alloying.

HTLV-I carrier with unusual brain MR imaging findings

We describe unusual brain MR imaging findings in a patient who is an HTLV-I carrier without myelopathy. T2-weighted MR images showed hyperintense signal abnormalities in the pyramidal tract, superior and middle cerebellar peduncles, and decussation of the superior cerebellar peduncles, in addition to subcortical white matter involvement. Diffusion-weighted images also showed hyperintense signal abnormalities in the same regions by T2 shine-through effect.

Possible risk factors of carotid artery atherosclerosis in the Japanese population: a primary prevention study in non-diabetic subjects

OBJECTIVE

Hyperinsulinemia has been associated with the risk of coronary heart disease, stroke, and renal disease in nondiabetic subjects. However, direct evidence that hyperinsulinemia per se is directly associated with atherosclerosis has been conflicting. The present study was designed to investigate the cross-sectional association of carotid artery atherosclerosis with insulin, independent of well-known cardiovascular risk factors, in nondiabetic subjects.

METHODS AND SUBJECTS

Between 1996 and 1997, 1,335 subjects (620 men and 715 women) were recruited from one Japanese community, interviewed, and examined. Clinical measurements in the study included intimal-medial thickness (IMT) of the carotid artery, fasting plasma insulin, serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fasting plasma glucose (FPG), hemoglobin type HbA1c, systolic blood pressure (SBP), diastolic blood pressure (DBP), and body mass index (BMI). We divided the subjects of both genders into three subgroups according to age (40-49 years of age; 50-59; and 60-69).

RESULTS

Using simple regression analysis, we found that IMT was significantly correlated with at least one of TC, LDL-C, HbA1c, SBP, DBP, and BMI in each subgroup. The results of multivariate analysis showed that IMT was independently correlated with TC, HDL-C, LDL-C, SBP and BMI in males and with TC, TG, HDL-C, LDL-C, HbA1c, SBP, DBP, and BMI in females. Insulin levels showed no correlation with IMT in either males or females.

CONCLUSION

Fasting hyperinsulinemia does not appear to be correlated with carotid artery atherosclerosis based on the present cross-sectional results.