Primary renal neuroendocrine tumor: A case report with computed tomography findings.

We report a rare case of a primary renal neuroendocrine tumor. The patient was a 64-year-old woman. The patient's chief complaint was gross hematuria. Dynamic contrast-enhanced computed tomography (CT) revealed a hypovascular mass 13 cm in diameter in the right kidney. The border of the mass was clear. A grossly contrast-impaired area and internal granular calcification were observed. A right radical nephrectomy was performed. Macroscopically, the mass was hemorrhaged and necrotic. It was diagnosed as a neuroendocrine tumor (NET) (Grade 2) histologically. Findings, such as hypovascularity, calcification, and necrosis, in our case were similar to those in previous reports. These findings are considered relatively characteristic of primary renal NETs.

Mid-term results of endovascular abdominal aortic aneurysm repair: is it possible to predict sac shrinkage?

PURPOSE: To evaluate the mid-term results of endovascular repair of abdominal aortic aneurysms and to predict subsequent sac shrinkage. METHODS: From December 2006 to April 2010, 114 abdominal aortic aneurysms were treated with stent grafts. The intraoperative sac pressure was measured by a microcatheter. Correlations between the diameter change and relevant factors were determined by a logistic regression analysis. RESULTS: Stent grafts were deployed successfully in all patients. Type-2 endoleaks were noted in 25 patients (22%); there were no type-1 or type-3 endoleaks at discharge. The clinical success rate was 99%. The diameter was reduced in 40 patients (56%) but remained unchanged in 32 (44%). There were no aneurysms that increased in diameter. At 2 years after the repair the rate of cumulative survival was 87% and freedom from secondary intervention was 95%. The sac pressure index after stent grafting with a reduced diameter was 0.56 ± 0.11 and that of patients with an unchanged diameter was 0.52 ± 0.14. There were no significant differences between the two groups. Persistent type-2 endoleaks had a slightly negative effect on sac shrinkage (P = 0.052). CONCLUSIONS: The mid-term results of endovascular aneurysm repair were satisfactory. Although it was difficult to predict the fate of a sac after stent grafting, persistent type-2 endoleaks were observed to have a slightly negative impact on sac shrinkage.

Granulomatosis with polyangiitis presenting as a solitary renal mass: A case report with imaging and literature review.

Granulomatosis with polyangiitis (GPA) manifests as necrotizing granulomatous inflammatory masses in the nasal cavity, paranasal sinuses, and lungs. However, a mass in the kidney is extremely rare. We herein report a case of GPA that presented as a solitary mass in the left kidney. The patient was a man in his 60s. A 2.5-cm solitary mass was incidentally discovered in the left kidney at another hospital and was followed-up. Eight months later, the mass had enlarged, and the patient visited our hospital for further examination and treatment. The mass was hypovascular, with unclear margins on contrast-enhanced computed tomography (CT). The signal of the mass was nonuniform and iso- to slightly hypo-intense on T2-weighted and diffusion-weighted magnetic resonance imaging (MRI). Enlarged para-aortic lymph nodes were also detected on the CT and MRI. Based on imaging, malignant tumors were suspected, and nephrectomy was performed. The pathological diagnosis was GPA. We performed a literature review of this rare renal manifestation and present a summary of reported imaging findings. If a hypovascular renal mass with an unclear margin can be found in those with GPA, unnecessary operations may be avoided by actively promoting renal biopsy.

Transcatheter Arterial Embolization Using Cone-beam Computed Tomography during Angiography and Automated Vessel Detection Software for Obscure Colonic Diverticular Hemorrhage after Unsuccessful Endoscopic Clipping: A Report of Two Cases.

We report the usefulness of cone-beam computed tomography angiography (CBCTA) and automated vessel detection (AVD) software in transcatheter arterial embolization in two cases of obscure ascending colonic diverticular hemorrhage after unsuccessful endoscopic clipping. Arteriography of the superior mesenteric artery demonstrated no active bleeding. Considering the positional relationship of the clips, we could narrow the responsible vessel down to two candidates but could not definitively identify the responsible vessel. We performed CBCTA at the marginal artery of the right colic artery, and the responsible branch was identified using AVD. The responsible vessel could be embolized, and hemostasis was achieved with no ischemic complications. CBCTA and AVD software for colonic diverticular hemorrhage after endoscopic clipping were useful for identifying the responsible vessel and in performing selective embolization.

Endovascular repair for a descending thoracic aortic aneurysm with a stent-graft covering the celiac artery: report of two cases.

An adequate landing zone for fixation and sealing is necessary for endovascular aneurysm repair (EVAR). This report presents two cases of a successful EVAR for thoracic aortic aneurysms (TAA) with a stent-graft covering the celiac artery (CA) to secure a distal landing zone. Case 1 was a 61-year-old man with a chronic traumatic descending TAA 12 mm away from the CA. Case 2 was a 79-year-old man with a descending TAA proximal to the CA. Preoperative angiography and computed tomography (CT) scan revealed a normal visceral blood flow including the peripancreatic arteries. Endovascular aneurysm repair with coverage of the CA was performed in both cases. Angiography after the EVAR demonstrated good blood flow to the CA branches via the peripancreatic arteries and a CT scan showed thrombosed aneurysms. Both patients were discharged without any abdominal symptoms. Endovascular aneurysm repair with a stent-graft covering the CA may therefore be an acceptable endovascular approach in treating selected TAA patients with a limited distal landing zone.

Practice Guidelines for Primary Care of Acute Abdomen 2015.

Since acute abdomen requires accurate diagnosis and treatment within a particular time limit to prevent mortality, the Japanese Society for Abdominal Emergency Medicine, in collaboration with four other medical societies, launched the Practice Guidelines for Primary Care of Acute Abdomen that were the first English guidelines in the world for the management of acute abdomen. Here we provide the highlights of these guidelines (all clinical questions and recommendations were shown in supplementary information). A systematic and comprehensive evaluation of the evidence for epidemiology, diagnosis, differential diagnosis, and primary treatment for acute abdomen was performed to develop the Practice Guidelines for Primary Care of Acute Abdomen 2015. Because many types of pathophysiological events underlie acute abdomen, these guidelines cover the primary care of adult patients with nontraumatic acute abdomen. A total of 108 questions based on nine subject areas were used to compile 113 recommendations. The subject areas included definition, epidemiology, history taking, physical examination, laboratory test, imaging studies, differential diagnosis, initial treatment, and education. Japanese medical circumstances were considered for grading the recommendations to assure useful information. The two-step methods for the initial management of acute abdomen were proposed. Early use of transfusion and analgesia, particularly intravenous acetaminophen, were recommended. The Practice Guidelines for Primary Care of Acute Abdomen 2015 have been prepared as the first evidence-based guidelines for the management of acute abdomen. We hope that these guidelines contribute to clinical practice and improve the primary care and prognosis of patients with acute abdomen.

The Practice Guidelines for Primary Care of Acute Abdomen 2015.

BACKGROUND: Since acute abdomen requires accurate diagnosis and treatment within a particular time limit to prevent mortality, the Japanese Society for Abdominal Emergency Medicine in collaboration with four other medical societies launched the Practice Guidelines for Primary Care of Acute Abdomen that were the first English guidelines in the world for the management of acute abdomen. Here we provide the highlights of these guidelines [all clinical questions (CQs) and recommendations are shown in supplementary information]. METHODS: A systematic and comprehensive evaluation of the evidence for epidemiology, diagnosis, differential diagnosis, and primary treatment for acute abdomen was performed to develop the Practice Guidelines for Primary Care of Acute Abdomen 2015. Because many types of pathophysiological events underlie acute abdomen, these guidelines cover the primary care of adult patients with nontraumatic acute abdomen. RESULTS: A total of 108 questions based on 9 subject areas were used to compile 113 recommendations. The subject areas included definition, epidemiology, history taking, physical examination, laboratory test, imaging studies, differential diagnosis, initial treatment, and education. Japanese medical circumstances were considered for grading the recommendations to assure useful information. The two-step methods for the initial management of acute abdomen were proposed. Early use of transfusion and analgesia, particularly intravenous acetaminophen, were recommended. CONCLUSIONS: The Practice Guidelines for Primary Care of Acute Abdomen 2015 have been prepared as the first evidence-based guidelines for the management of acute abdomen. We hope that these guidelines contribute to clinical practice and improve the primary care and prognosis of patients with acute abdomen.

Human comparative study of zinc and copper excretion via urine after administration of magnetic resonance imaging contrast agents.

PURPOSE: To evaluate the in-vivo pharmacokinetics of magnetic resonance imaging (MRI) contrast agents, the excretion of zinc and copper via urine was studied for three gadolinium (Gd) chelate complexes. MATERIALS AND METHODS: Urine samples were taken before, three hours, and six hours after intravenous administration of Gd-DTPA-BMA, Gd-DTPA, and Gd-DOTA at 0.2 ml/kg to five patients each who underwent contrast-enhanced MRI. Five patients who had non-contrast MRI were evaluated as controls. Urine was assayed for quantitative analysis of zinc and copper using atomic absorption analysis. RESULTS: Gd-DTPA-BMA caused the highest increase in zinc excretion among the three agents, 1,795 +/- 1,273 microg at 3 hours and 985 +/- 434 microg at 3 to 6 hours. Gd-DOTA did not cause a significant increase in zinc excretion, 75 +/- 39 microg at 3 hours and 78+/-65 microg at 3 to 6 hours. Gd-DTPA caused a moderate increase in zinc excretion, 665 +/- 240 microg at 3 hours and 378 +/- 173 microg at 3 to 6 hours. Excretion of copper did not show a significant difference among the three agents. CONCLUSION: Gd-DOTA was found to be the most kinetically inert among the three agents tested. The difference in zinc excretion among the MR contrast agents is possibly related to in-vivo transmetallation of the Gd chelate complexes correlated with variable stability of the contrast agents. The large amount of excess ligands contained in some MR contrast agents was also considered to be responsible for the increase of urinary zinc excretion.

Uterine artery embolization by use of porous gelatin particles for symptomatic uterine leiomyomas: comparison with hand-cut gelatin sponge particles.

PURPOSE: To evaluate the results of uterine artery embolization (UAE) for symptomatic uterine leiomyoma by use of porous gelatin particles (PGP) in comparison with conventional hand-cut gelatin sponge particles. MATERIALS AND METHODS: One hundred and fifteen consecutive patients who had undergone UAE were retrospectively assessed. The first 64 patients were treated with hand-cut gelatin sponge and the last 51 with PGP. Extent of infarction, volume reduction of the dominant leiomyoma on magnetic resonance (MR) imaging, and change in symptoms were assessed. RESULTS: UAE was successfully performed for all patients. No major complications were observed. MR images one month after UAE showed that the mean extent of infarction of the dominant leiomyoma was 97 % for patients treated with PGP and 96 % for those treated with hand-cut gelatin sponge. Volume reductions of the dominant leiomyoma after 3, 6, 12, and 24 months were, respectively, 45, 56, 62, and 66 % for use of PGP and 45, 57, 63, and 68 % for use of hand-cut gelatin sponge. Symptoms including heavy menstrual bleeding, heavy menstrual pain, and abdominal heaviness had improved by 95-100 % at 12 months. There was no difference between the two groups. CONCLUSION: UAE with PGP is safe, and as effective as conventional gelatin sponge particles.

Metastatic embryonal carcinoma mimicking locally advanced non-small cell lung cancer.

A 50-year-old man with a history of smoking of 45 pack-years underwent right lower lobectomy after neoadjuvant chemoradiotherapy for locally advanced non-small cell lung cancer diagnosed on a bronchial biopsy and standard imaging examinations, including chest-abdominal contrast-enhanced computed tomography (CT) and whole-body F-18 fluorodeoxyglucose positron emission tomography/CT. Left orchiectomy was performed simultaneously to treat the slightly swollen left testis, which had remained unchanged for over five years. The thoracic tumor was proven to be in pathological complete remission and the testicular lesion was pathologically diagnosed as an embryonal carcinoma. Furthermore, a pathological reevaluation of the preoperative bronchial biopsy specimen revealed the lung tumor to be a metastatic embryonal carcinoma.

Increased radiation dose by automatic exposure control system during fluoroscopy and angiography of pelvis due to contrast material in the bladder: experimental study.

PURPOSE: To evaluate the increase of radiation dose caused by contrast material excreted in the bladder during vascular interventional procedures of the pelvis. MATERIALS AND METHODS: A latex balloon filled with diluted contrast material, simulating the bladder, was placed in a water phantom. Entrance dose rates were measured under various conditions with and without the balloon. In animal experiments, skin doses during fluoroscopy and angiographic image acquisitions were measured at the pelvis of a swine before and after the contrast was excreted in the bladder. RESULTS: In phantom experiments, fluoroscopic dose rates increased 1.3- to 3.9-fold when the contrast-filled balloon was placed at the periphery of the phantom. The dose rates increased 3.0- to 4.0-fold when the balloon was placed at the center. In the animal experiment, dose rates increased 1.4- to 2.0-fold when the bladder was filled with contrast material. Skin doses during 10-second angiographic image acquisition also increased 1.1- to 2.3-fold when the bladder was filled with contrast. CONCLUSION: When the bladder is filled with excreted contrast material, skin doses delivered by fluoroscopy and angiography will increase. Removal of urine is recommended during vascular interventional procedures of the pelvis.

Ethanolamine oleate sclerotherapy combined with transarterial embolization using n-butyl cyanoacrylate for extracranial arteriovenous malformations.

PURPOSE: This study was designed to assess the safety and effectiveness of ethanolamine oleate (EO) sclerotherapy combined with transarterial embolization using a liquid adhesive agent (n-butyl cyanoacrylate, NBCA) for treatment of extracranial arteriovenous malformations (AVMs). METHODS: Twenty-four patients with symptomatic AVMs in the head and neck (n = 15), extremity (n = 5), and trunk (n = 4) with a mean age of 44 years (range, 18-78) treated with EO sclerotherapy were retrospectively assessed. AVMs were classified according to the angiographic morphology of the nidus. There were 7 type II (arteriolovenous fistulae), 6 type IIIa (arteriolovenulous fistulae with nondilated fistula), and 11 type IIIb (arteriolovenulous fistulae with dilated fistula). Transarterial embolization using NBCA was performed to reduce arterial flow before sclerotherapy. EO mixed with contrast material was delivered by percutaneous direct puncture or by catheterization into the draining vein under balloon occlusion. RESULTS: Three (13%) of 24 patients were cured, 17 (71%) had partial remission, and 4 (16%) no remission. Treatment was considered effective (cure and partial remission) in 20 patients (83%). Four patients (16%) experienced transient minor complications, including self-healing skin ulcer (n = 3) and localized deep venous thrombosis (n = 1). There were no major complications. CONCLUSIONS: EO sclerotherapy combined with transarterial embolization using NBCA is safe and effective for treating extracranial AVMs with an acceptable risk of minor complications.

Training on insertion and retrieval of optional inferior vena cava filters for interventional radiologists with little or just some experience with the combined use of blood vessel and animal models.

PURPOSE: To evaluate the usefulness of a tool that we developed to simulate performance of insertion and retrieval of optional inferior vena cava filters to be additionally used in training of beginners with an animal model. SUBJECTS AND METHODS: Thirty young doctors who had little or no experience in insertion and/or retrieval of filters were subjects of this study to evaluate the training tool. Eleven trainees practiced both insertion and retrieval of filters first with the animal model then with the blood vessel model while 19 trainees first practiced with the blood vessel model then with the animal model. RESULTS: All trainees successfully inserted the filter. Two of the 11 trainees who used the animal model before the blood vessel model failed in retrieval, and 2 of the 19 trainees who used the blood vessel model before the animal model failed. In the former group, mean time for filter implantation and withdrawal in the animal model was 75 ± 62 s and 341 ± 238 s, respectively, and in the latter group were 54 ± 16 s and 311 ± 236 s, respectively. CONCLUSION: Training with the combination of a blood vessel model and animal model is helpful for beginners to learn to insert and withdraw optional filters.

Gossypiboma mimicking gastrointestinal stromal tumor causing intestinal obstruction: a case report.

A 41-year-old woman was admitted to our hospital with abdominal pain that developed about 1 year after a Cesarean section. Pelvic computed tomography (CT) revealed diffuse dilation of the small intestine with fluid shadows and a pelvic tumor 55 mm in diameter. The density of the tumor, which was not enhanced by intravenous contrast medium, was diffuse and similar to that of muscular tissue, whereas the density of a capsule surrounding the mass was relatively high. T1- and T2-weighted pelvic magnetic resonance imaging (MRI) of the tumor revealed the same diffuse low-intensity signals as muscular tissue, and diffuse high-intensity signals, respectively. The CT and MRI findings were consistent with those of a gastrointestinal stromal tumor (GIST) causing ileus of the small intestine. As inserting an ileus tube did not improve her symptoms, the patient was scheduled for tumor resection. The operative findings revealed a hard, solid tumor adhering to the surrounding small intestine. The macroscopic findings revealed that the tumor consisted of layers of stratified gauze surrounded by a thick granulomatous wall. The gossypiboma was considered to have originated from gauze that had been left behind after the Cesarean section. If a patient has a history of surgery, the possibility of gossypiboma should be considered when CT or MRI findings indicate features of GIST.

Oblique approach for CT-guided liver radiofrequency ablation using multiplanar reformation images in hepatocellular carcinoma.

PURPOSE: To evaluate the feasibility and safety of CT-guided radiofrequency (RF) ablation by caudal-cranial oblique insertion using multiplanar reformation (MPR) images for hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Twenty-two HCCs in 19 patients that were difficult to demonstrate on ultrasound (mean tumor diameter was 17.5 mm) were treated with CT-guided RF ablation by caudal-cranial oblique insertion to avoid pneumothorax, using MPR images after transcatheter arterial chemoembolization. The insertion point and direction of insertion, avoiding aerated lung parenchyma, bones, large vessels, and intestine, were sought on the MPR images. Technical success was defined as complete eradication of tumor enhancement in the contrast-enhanced CT. Local tumor progression was defined by the appearance of enhanced tumor adjacent to the zone of ablation. The technical success rate, local tumor progression, and complications were investigated. RESULTS: The coronal plane was used for insertion in 18 tumors, the sagittal plane in 3 tumors, and the oblique plane in 1 tumor. RF electrode placement was successful and complete necrosis was obtained in all cases. During the mean follow-up period of 38.0 months, local tumor progression was not detected in any of the patients. There were no major complications, including pneumothorax. CONCLUSION: CT-guided RF ablation by caudal-cranial oblique insertion using MPR images is a feasible and safe therapeutic option.

Intraoperative sac pressure measurement during endovascular abdominal aortic aneurysm repair.

PURPOSE: Intraoperative sac pressure was measured during endovascular abdominal aortic aneurysm repair (EVAR) to evaluate the clinical significance of sac pressure measurement. METHODS: A microcatheter was placed in an aneurysm sac from the contralateral femoral artery, and sac pressure was measured during EVAR procedures in 47 patients. Aortic blood pressure was measured as a control by a catheter from the left brachial artery. RESULTS: The systolic sac pressure index (SPI) was 0.87 +/- 0.10 after main-body deployment, 0.63 +/- 0.12 after leg deployment (P < 0.01), and 0.56 +/- 0.12 after completion of the procedure (P < 0.01). Pulse pressure was 55 +/- 21 mmHg, 23 +/- 15 mmHg (P < 0.01), and 16 +/- 12 mmHg (P < 0.01), respectively. SPI showed no significant differences between the Zenith and Excluder stent grafts (0.56 +/- 0.13 vs. 0.54 +/- 0.10, NS). Type I endoleak was found in seven patients (15%), and the SPI decreased from 0.62 +/- 0.10 to 0.55 +/- 0.10 (P = 0.10) after fixing procedures. Type II endoleak was found in 12 patients (26%) by completion angiography. The SPI showed no difference between type II endoleak positive and negative (0.58 +/- 0.12 vs. 0.55 +/- 0.12, NS). There were no significant differences between the final SPI of abdominal aortic aneurysms in which the diameter decreased in the follow-up and that of abdominal aortic aneurysms in which the diameter did not change (0.53 +/- 0.12 vs. 0.57 +/- 0.12, NS). CONCLUSIONS: Sac pressure measurement was useful for instant hemodynamic evaluation of the EVAR procedure, especially in type I endoleaks. However, on the basis of this small study, the SPI cannot be used to reliably predict sac growth or regression.

Emergent coil embolization for ruptured renal artery aneurysm.

We report a case of ruptured renal artery aneurysm successfully treated by emergent transcatheter embolization with microcoils. A 66-year-old woman was referred for emergency treatment after presenting with sudden-onset left flank pain and vomiting. Blood examination showed anemia. Computed tomography demonstrated a partly calcified mass with massive retroperitoneal hematoma. With the diagnosis of a ruptured left renal artery aneurysm, emergency angiography was performed. Left renal arteriography demonstrated a saccular aneurysm at the lower aspect of the renal hilum. A total of five microcoils were placed at the arterial branch, including the orifice of the aneurysm. The first coil was partly lodged in a branch near the orifice of the aneurysm that was used as an "anchor" to prevent subsequent coils from migrating and effectively occluding the parent artery with a short segment. Two branches originating from the renal hilum were preserved. The postoperative course was favorable. Endovascular treatments, including coil embolization, appear to be effective, safe, and less invasive than surgery. This method should be considered as a treatment of choice for ruptured renal artery aneurysm.

Angiographic guidewire with measuring markers: design and clinical experience.

PURPOSE: We have developed an angiographic guidewire with measuring markers to determine accurately how far a guidewire is inserted within a catheter. We investigated whether use of this guidewire reduces the risk of vascular injury and the fluoroscopic time during guidewire manipulations. METHODS: Four markers were put on the surface of the guidewire at 80, 100, 110, and 120 cm from the tip. The actual lengths of 54 catheters from seven manufacturers were measured and compared with the nominal lengths. Sixty consecutive patients who underwent angiography were randomized into two groups: in one group guidewires with surface markers were used (marker group) and in the other group, conventional guidewires (control group). For each guidewire insertion, the fluoroscopic time before the guidewire was pushed forward into the vessel lumen was recorded. The number of occasions on which unintentionally the guidewire had already been pushed out of the catheter at the start of fluoroscopy was also evaluated. RESULTS: The actual lengths of all catheters were greater than the nominal lengths by 1.0-11.0 cm. Mean fluoroscopic time for each guidewire insertion was 3.3 sec in the marker group and 5.7 sec in the control group (p < 0.05). Guidewires were unintentionally pushed out of the catheters without fluoroscopy three times (3.6%), in each case in the control group. CONCLUSION: The guidewire with measuring markers is effective for enhancing safety and in reducing fluoroscopic radiation during angiographic procedures. It is recommended that operators be aware that actual lengths of catheters may vary significantly from the nominal lengths listed; they should be aware of this with any guidewire, but particularly with the angiographic measuring guidewire.