Clinical outcomes and future fertility after uterine artery embolization for postpartum and post-abortion hemorrhage.

BACKGROUND: Postpartum hemorrhage (PPH) and post-abortion hemorrhage (PAH) are life-threatening conditions. PURPOSE: To evaluate the efficacy and safety of uterine arterial embolization (UAE) for PPH and PAH and to investigate future fertility after UAE. MATERIAL AND METHODS: This study included 57 consecutive patients (mean age = 34 years) who underwent UAE for PPH (n = 46) and PAH (n = 11) at our institution between January 2011 and December 2022. Technical success, non-visualization of the peripheral portion of bilateral uterine arteries on angiography, and clinical success, complete hemostasis after UAE, were assessed. UAE-associated complications and factors related to clinical success were analyzed. Pregnancy outcomes after UAE and complications during subsequent pregnancy were investigated in 16 patients who desired fertility and were followed up for >1 year. RESULTS: The technical and clinical success rates were 100% and 84.2%, respectively. Sepsis (n = 1) and uterine empyema (n = 1) were observed as severe complications. Placental disorder, bleeding within 24 h after delivery or abortion, ≥1.5 shock index, ≥6 units of transfusion erythrocytes, and ≥8 obstetrical disseminated intravascular coagulation score were significantly associated with unfavorable clinical outcomes. In total, 16 pregnancies were observed in 12 patients after UAE, three of which were miscarriages and 13 were successful live births. During pregnancy, uterine rupture (n = 1) and accreta (n = 1) were observed. CONCLUSION: UAE is an effective treatment for PPH and PAH. Although UAE could preserve future fertility, careful attention should be paid to perinatal management for unusual complications.

A preliminary animal study of thermal rheology fluid as a new temperature-dependent liquid intravascular embolic material.

PURPOSE: Thermal rheology (TR) fluid, which comprises polyethylene (PE) particles, their dispersant, and solvent, is a material that increases in viscosity to various degrees depending on the type and ratio of these constituents when its temperature rises. The viscosity of type 1 (TRF-1) increases more than that of type 2 (TRF-2) near rabbit body temperature. This preliminary animal study aimed to determine the basic characteristics and embolic effect of TR fluid by comparing TRF-1 and TRF-2. MATERIALS AND METHODS: Twenty-four Japanese white rabbits underwent unilateral renal artery embolization using TRF-1 or TRF-2 and follow-up angiography at 7 or 28 days (4 subgroups, n = 6 each). Subsequently, the rabbits were euthanized, and the embolized kidneys were removed for pathological examination. The primary and final embolization rates were defined as the ratio of renal artery area not visible immediately after embolization and follow-up angiography, respectively, to visualized renal artery area before embolization. The final embolization rate and maximum vessel diameter filled with PE particles were compared between materials. Moreover, the embolic effect was determined to be persistent when a two-sided 95% confidence interval (CI) for the difference in means between the embolization rates was < 5%. RESULTS: The final embolization rate was significantly higher for the TRF-1 than for the TRF-2 at both 7 (mean 80.7% [SD 18.7] vs. 28.4% [19.9], p = 0.001) and 28 days (94.0% [3.5] vs. 37.8% [15.5], p < 0.001). The maximum occluded vessel diameter was significantly larger for TRF-1 than for TRF-2 (870 µm [417] vs. 270 µm [163], p < 0.001). The embolic effect of TRF-1 was persistent until 28 days (difference between rates - 3.3 [95% CI - 10.0-3.4]). CONCLUSION: The embolic effect of TRF-1 was more persistent than that of TRF-2, and the persistency depended on the type and ratio of TR fluid constituents.

Effect of Portal Vein and Hepatic Artery Occlusion on Radiofrequency Ablation: Animal Experiment Comparing MR and Histology Measurements of the Ablation Zones.

PURPOSE: This animal experimental study evaluated how hepatic artery and portal vein transient occlusion affects the ablation zone of hepatic radiofrequency ablation (RFA). MATERIAL AND METHODS: Twenty-one rabbits were divided into three groups of seven each: (1) control, (2) hepatic artery occlusion, and (3) portal vein occlusion by a balloon catheter. For each rabbit, two or three RFA sessions were performed using an electrode needle. Ablation time, temperature around the tip of RFA needle at the end of RFA, ablation volume on fat-suppressed T1-weighted image in the hepatobiliary phase, and coagulative necrosis area on histopathology were measured and compared between the three groups using the Kruskal-Wallis paired Mann-Whitney U tests. RESULTS: In 43 RFA sessions (group 1, 15; group 2, 14; group 3, 14), mean tissue temperature in group 3 (77.0 °C ± 7.7 °C) was significantly higher compared to groups 1 (59.2 °C ± 18.8 °C; P = 0.010) and 2 (67.5 °C ± 9.9 °C; P = 0.010). In addition, mean ablation volume and coagulative necrosis in group 3 (2.10 ± 1.37 mm3 and 0.86 ± 0.28 mm2, respectively) were larger compared to groups 1 (0.84 ± 0.30 mm3; P < 0.001 and 0.55 ± 0.26 mm2; P = 0.020, respectively) and 2 (0.89 ± 0.59 mm3; P = 0.002 and 0.60 ± 0.22 mm2; P = 0.024, respectively). CONCLUSION: Portal vein occlusion potentially boosts tissue temperature, ablation volume, and area of histopathologically proven coagulative necrosis during hepatic RFA in the non-cirrhotic liver.

Naturally shrunk visceral artery aneurysms by stenting for the superior mesenteric artery occlusion.

A 77-year-old woman who had experienced postprandial abdominal pain for four years was admitted to our institution presenting sudden and severe abdominal pain. Contrast-enhanced computed tomography (CECT) demonstrated complete short-segmented occlusion in the orifice of the superior mesenteric artery (SMA), and saccular aneurysms in the right hepatic artery and the anterior superior pancreaticoduodenal artery. She was diagnosed with abdominal angina due to occlusion of the SMA. The SMA was recanalized by stenting, and a CECT scan confirmed naturally shrunk aneurysms after eight months. The patency of the SMA was maintained at five years after endovascular treatment.

Noncontrast MRI of acute abdominal pain caused by gastrointestinal lesions: indications, protocol, and image interpretation.

Gastrointestinal tract lesions are major causes of acute abdominal pain. A rapid, accurate, and reliable diagnosis is required to manage patients. Magnetic resonance imaging (MRI) is a nonionizing modality that is beneficial for pregnant women, children, and young adults who are sensitive to ionizing radiation. For patients with renal impairment who are not accurately diagnosed with noncontrast computed tomography, noncontrast MRI can serve as an alternative diagnostic modality. MRI protocols used for acute abdominal pain are supposed to be optimized and prioritized to shorten scanning times. Single-shot T2-weighted and fat-suppressed T2-weighted imaging are important pulse sequences that are used to reveal pathology and inflammation in the gastrointestinal tract. Diffusion-weighted imaging clearly depicts inflammation and abscesses as hyperintense lesions. Most acute gastrointestinal tract lesions, including inflammation, ischemia, obstruction, and perforation, demonstrate bowel wall thickening. Bowel obstruction and adynamic ileus present bowel dilatation, and perforation and penetration show bowel wall defects. MRI can be used to reveal these pathological findings with some characteristics depending on their underlying pathophysiology. This review article discusses imaging modalities for acute abdominal pain, describes a noncontrast MRI protocol for acute abdominal pain caused by gastrointestinal tract lesions, and reviews MRI findings of acute gastrointestinal tract lesions.

MR Imaging-based Evaluation of Mesenteric Ischemia Caused by Strangulated Small Bowel Obstruction and Mesenteric Venous Occlusion: An Experimental Study Using Rabbits.

PURPOSE: This study assessed the MRI findings of strangulated small bowel obstruction (SBO) and mesenteric venous occlusion (MVO) in a rabbit model using 3T MRI. MATERIALS AND METHODS: Twenty rabbits were included in this study. The strangulated SBO and MVO models were generated via surgical procedures in nine rabbits, and sham surgery was performed in two rabbits. The success of generating the models was confirmed via angiographic, macroscopic, and microscopic findings after the surgical procedure. MRI was performed before and 30 min after inducing mesenteric ischemia. T1-weighted images (T1WIs), T2-weighted images (T2WIs), and fat-suppressed T2WIs (FS-T2WIs) were obtained using the BLADE technique, and fat-suppressed T1WIs (FS-T1WIs) were obtained. The signal intensities of the affected bowel before and after the surgical procedures were visually categorized as high, iso, and low intense compared with the findings for the normal bowel wall on all sequences. Bowel wall thickness was measured, and the signal intensity ratio (SI ratio) was calculated using the signal intensities of the bowel wall and psoas muscle. RESULTS: Angiographic, macroscopic, and microscopic findings confirmed that all surgical procedures were successful. The ischemic bowel wall was thicker than the normal bowel. The bowel wall was thicker in the MVO model (3.17 ± 0.55 mm) than in the strangulated SBO model (2.26 ± 0.46 mm). The signal intensity and SI ratio of the bowel wall were significantly higher after the procedure than before the procedure on all sequences in both models. The mesentery adjacent to the ischemic bowel loop exhibited a high signal intensity in all animals on FS-T2WIs. CONCLUSION: Non-contrast MRI can be used to evaluate mesenteric ischemia caused by strangulated SBO and MVO. FS-T2WIs represented the best modality for depicting the high signal intensity in the bowel wall and mesentery caused by ischemia.

Management of acute cholecystitis after biliary stenting for malignant obstruction: comparison of percutaneous gallbladder drainage and aspiration.

PURPOSE: To evaluate and compare the clinical outcomes between percutaneous gallbladder drainage (PGBD) and percutaneous gallbladder aspiration (PGBA) for acute cholecystitis after biliary stenting for malignant biliary obstruction. MATERIALS AND METHODS: Twenty-six and 14 patients underwent PGBD and PGBA, respectively, for acute cholecystitis after biliary stenting for malignant obstruction. The technical success rate, clinical effectiveness, and safety were compared between the 2 groups. RESULTS: Technical success was achieved in all patients. Clinical effectiveness rate was significantly higher in the PGBD group than in the PGBA group [100% (26/26) vs. 57% (8/14), p < 0.01]. In the PGBA group, clinical effectiveness rate was significantly lower in patients with tumor involvement of the cystic duct [13% (1/8) with involvement vs. 83% (5/6) without involvement, p = 0.03]. There were no deaths related to the procedure or acute cholecystitis aggravation. Pleural effusion and biliary peritonitis occurred in 1 patient each after PGBD and intra-abdominal bleeding occurred in 1 patient after PGBA as complications requiring treatment. CONCLUSION: Although PGBD was a more effective treatment for acute cholecystitis after biliary stenting for malignant obstruction, PGBA may be a less invasive option for high-risk patients without tumor involvement of the cystic duct.

Change in hepatic hemodynamics assessed by hepatic arterial blood pressure and computed tomography during hepatic angiography with the double balloon technique.

PURPOSE: To assess the change in hepatic arterial blood pressure (HABP) and computed tomography during hepatic arteriography (CTHA) using the double balloon technique. MATERIALS AND METHODS: Nine patients with hepatocellular carcinoma (HCC) were enrolled. We inserted a 5.2-Fr balloon catheter into the common or proper hepatic artery and a 1.8-Fr microballoon catheter into the lobar or segmental artery feeding the HCC. HABPs were measured with the 1.8-Fr microballoon catheter (usual-HABP), with the 1.8-Fr balloon inflated (B-HABP), and with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-HABP). CTHAs were performed via a 1.8-Fr microcatheter (usual-CTHA), with the 1.8-Fr balloon inflated (B-CTHA selective), with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-CTHA selective), and via the 5.2-Fr catheter with the 1.8-Fr balloon inflated (B-CTHA whole) and with both the 5.2-Fr and 1.8-Fr balloons inflated (BB-CTHA whole). RESULTS: In all cases, B-HABP was lower than usual-HABP. There was a decrease in BB-HABP in comparison with B-HABP in cases with occlusion of the proper hepatic artery. The contrast effect of B-CTHA selective increased in four cases. The contrast effect on B-CTHA whole remained in all cases. CONCLUSION: This technique can be useful in decreasing HABP and collateral blood flow from the adjacent hepatic segment.

The Utility of Indigo Carmine and Lipiodol Mixture for Preoperative Pulmonary Nodule Localization before Video-Assisted Thoracic Surgery.

PURPOSE: To evaluate the safety and efficacy of a mixture of indigo carmine and lipiodol (MIL) as a marker of pulmonary nodule before video-assisted thoracic surgery (VATS). MATERIALS AND METHODS: One hundred sixty-eight sessions of pulmonary marking were performed using MIL before VATS for 184 nodules (mean size, 1.2 ± 0.6 cm; range, 0.3-3.6 cm) on 157 patients (83 men and 74 women; median age, 66 years). The mean distance between the lung surface and the nodule was 0.8 ± 0.7 cm (range, 0-3.9 cm). MIL was injected near the nodule using a 23-gauge needle. Mean number of 1.2 ± 0.4 (range, 1-3) punctures were performed in a session for the target nodules, with mean number of 1.1 ± 0.3 (range, 1-3). Successful targeting, localization, and VATS were defined as achievement of lipiodol accumulation at the target site on computed tomography, detection of the nodule in the operative field by fluoroscopy or visualization of dye pigmentation, and complete resection of the target nodule with sufficient margin, respectively. RESULTS: The successful targeting rate was 100%, and the successful localization rate was 99.5%, with dye pigmentation for 160 nodules (87.0%) and intraoperative fluoroscopy for 23 nodules (12.5%). Successful VATS was achieved for 181 nodules (98.4%). Two nodules (1.1%) were not resectable, and surgical margin was positive in 1 nodule (0.5%). Complications requiring interventions occurred in 5 sessions (3.0%) and included pneumothorax with chest tube placement (n = 3) and aspiration (n = 2). No complication related to the injected MIL occurred. CONCLUSIONS: MIL was safe and useful for preoperative pulmonary nodule marking.

Covered stent placement for emergency repair of a ruptured superior mesenteric artery pseudoaneurysm in advanced pancreatic head cancer.

Superior mesenteric artery (SMA) pseudoaneurysms are rare but fatal. Surgical repair is an ideal treatment; however, it is inappropriate in patients with SMA pseudoaneurysm due to advanced cancer, and endovascular therapy is an alternative treatment for nonsurgical candidates. Here, we report a case of SMA pseudoaneurysm in a patient with advanced pancreatic cancer, which was successfully treated with the placement of a biliary covered stent.