Arterioureteral fistula and refractory fatal pseudo-aneurysm in a patient receiving kidney transplantation.

Arterioureteral fistula represents a rare yet consequential urological complication characterized by persistent and refractory urinary tract bleeding. Its emergence typically involves aneurysm formation, presenting significant life-threatening implications. Nonetheless, its infrequency contributes to sparse documentation of incidences in post-kidney transplant recipients, thereby fostering numerous uncertainties concerning associated risks. A 67-year-old male patient, afflicted with end-stage renal failure and a history of urinary tract infection, underwent a living donor kidney transplant four months prior. Complications involving intraoperative bleeding necessitated the prolonged placement of a ureteral stent post-surgery. Subsequently, he experienced an abrupt onset of ureteral bleeding accompanied by shock, later diagnosed via contrast-enhanced computed tomography as pseudo-aneurysm formation in the right external iliac artery proximal to the allograft renal artery anastomosis, in conjunction with a fistula formation involving the donor ureter. Despite repeated attempts at intervention with covered stenting, the aneurysm persisted and proved refractory to resolution. Tragically, seven months later, the aneurysm ruptured, culminating in the demise of the patient. Our report details a case involving perioperative complications following kidney transplantation, persistent bacteriuria, and prolonged ureteral stenting, ultimately leading to the development of an arterioureteral fistula. Despite undergoing stent graft insertion as an intervention, the patient succumbed to aneurysm rupture associated with the arterioureteral fistula. This condition, though rare, can prove fatal following kidney transplantation. Consequently, future endeavors in this domain necessitate an emphasis on optimizing risk management, refining diagnostic approaches, and devising more effective therapeutic strategies to mitigate such complications.

Diagnosis of a Dural Arteriovenous Fistula Involving the Superior Sagittal Sinus: The MMA Sign on Routine 3D-TOF MR Angiography.

BACKGROUND AND PURPOSE: The main feeding artery of a dural arteriovenous fistula (DAVF) involving the superior sagittal sinus (SSS) is the middle meningeal artery (MMA). MMA extends continuously from the proximal part to SSS in DAVF involving SSS. It is possible to diagnose DAVF involving SSS by evaluating the proximal part of MMA on routine three-dimensional time-of-flight MR angiography (MRA). We termed the finding in an anteroposterior maximum intensity projection (MIP) image of routine MRA in which MMA was continuously visualized at the top of the imaging slab (the upper corpus callosum level) without tapering as the MMA sign. The purpose of the present study was to examine the frequency of the MMA sign on routine MRA in patients with DAVF involving SSS and control patients. MATERIALS AND METHODS: Subjects comprised 18 patients with DAVF involving SSS confirmed by angiography and 871 control subjects who underwent routine MRA. The presence of the MMA sign was retrospectively evaluated using an anteroposterior MIP image of routine MRA in patients with DAVF involving SSS and control patients. RESULTS: The MMA sign was observed in 17 of the 18 (94%) patients with DAVF involving SSS. In one patient with DAVF involving the posterior part of SSS without the MMA sign, the main feeding artery was the occipital artery, not MMA. The MMA sign was observed in 13 of the 871 (1.5%) control patients. CONCLUSION: The MMA sign on routine MRA is useful, suggesting DAVF involving SSS.

Detection of Hyperdense Arterial Sign in Acute Ischemic Stroke with Dual-Energy Computed Tomography: Optimal Combination with X-ray Energy and Slice Thickness.

BACKGROUND: The hyperdense artery sign (HAS) in acute ischemic stroke (AIS) is considered an important marker of a thrombus on computed tomography (CT). An advantage of scanning with dual-energy CT (DECT) is its ability to reconstruct CT images with various energies using the virtual monochromatic imaging (VMI) technique. The aim of this study was to investigate the optimal combination of X-ray energy and slice thickness to detect HASs on DECT. METHODS: A total of 32 patients with confirmed occlusion of the horizontal (M1) portion of the middle cerebral artery were included in this study. Modified contrast-to-noise ratio (modified CNR) analysis was used as a method for evaluating HASs in AIS. A region of interest (ROI) was set as an HAS, the M1 portion, and an approximately 2 cm diameter ROI was set as the background including the HAS and measured. CT images with X-ray energies from 40 to 190 keV, with increments of 10 keV, were reconstructed based on VMI with 1, 2, and 3 mm slice thicknesses. RESULTS: The top five combinations of X-ray energy and slice thickness in descending order of the mean HAS-modified CNR were as follows: Rank 1, 60 keV-1 mm; Rank 2, 70 keV-1 mm; Rank 3, 60 keV-2 mm; Rank 4, 80 keV-2 mm; Rank 5, 60 keV-3 mm. CONCLUSIONS: Our study showed that the optimal combination to detect an HAS was 60 keV and a 1 mm slice thickness on DECT.

Successful treatment with nivolumab in a patient with unresectable oral squamous cell carcinoma following ineffective chemoradiotherapy.

Key clinical message: Nivolumab has been clinically successful in prolonging the overall survival of patients with recurrent and metastatic head and neck cancer, complete remission is rare. Synergistic combinations of immunotherapy and conventional cancer treatments, such as radiotherapy or chemotherapy, are likely to be the most viable strategies for improving patient responses. Abstract: Immune checkpoint inhibitors have revolutionized recurrent, metastatic oral cancer treatment; however complete remission in advanced stages is unusual. We present a case of complete remission of advanced oral squamous cell carcinoma for >4 years in a 64-year-old Japanese woman, that responded poorly to chemoradiotherapy but well to subsequent nivolumab treatment.

Usefulness of the femoral vein as a graft for portal vein/superior mesenteric vein reconstruction during pancreatectomy.

Shibuya and colleagues describe their innovative technique using the femoral vein as a graft for portal vein/superior mesenteric vein reconstruction during pancreatectomy. The femoral vein has an appropriate diameter and is particularly useful when long resection of the superior mesenteric vein is required in surgery for locally advanced pancreatic ductal adenocarcinoma.

Intraoperative Heparin Resistance after Administration of Andexanet Alfa to Manage an Internal Iliac Artery Aneurysm Rupture: A Case Report.

Antithrombotic agents are increasingly prescribed to older adults; however, they are associated with bleeding-related complications. We describe a case of intraoperative heparin resistance after administration of andexanet alfa (AA). An 81-year-old man was diagnosed with a ruptured internal iliac artery aneurysm. The patient required emergency endovascular aneurysm repair and was treated with AA because he was receiving apixaban. Despite high-dose intraoperative heparin administration, his activated coagulation time was not prolonged. Our findings suggest that AA should be administered with caution in patients experiencing potentially fatal bleeding (requiring surgical intervention) who are also receiving direct oral anticoagulants.

Case Report: Response to Intra-arterial Cisplatin and Concurrent Radiotherapy Followed by Salvage Surgery in a Patient With Advanced Primary Sinonasal Low-Grade Non-intestinal Adenocarcinoma.

Background: The clinical usefulness of concurrent chemoradiotherapy before surgery in the treatment of primary, locally advanced sinonasal low-grade, non-intestinal type adenocarcinoma (LG non-ITAC) is unclear. Methods: We present the first case report of the efficacy of super-selective intra-arterial cisplatin (CDDP) infusion concurrent with conventional fractionated radiotherapy (RT) for LG non-ITAC in a Japanese patient. Results: A white, rugged-marginal mass that was histopathologically diagnosed as LG non-ITAC occupied the right nasal cavity. Based on the imaging findings, including computed tomography, magnetic resonance imaging, and positron emission tomography, the tumor was diagnosed as T4aN0M0, stage IVa. After treatment, the nasal tumor disappeared leaving only a small bulge in the medial wall of the middle turbinate. The patient also underwent right transnasal ethmoidectomy performed as salvage surgery. A histopathological examination revealed that the lesion was replaced by granulation tissue with lymphocytic infiltration and hemosiderin-laden macrophages, and no viable tumor cells remained. In the seven years after treatment, the patient has not experienced any local recurrence or regional or distant metastasis. Conclusions: Super-selective intra-arterial CDDP infusion concurrent with conventional fractionated RT followed by salvage surgery might be useful for the management of sinonasal LG non-ITAC.

Metachronous rupture of a residual pancreaticoduodenal aneurysm after release of the median arcuate ligament: a case report.

BACKGROUND: Multiple pancreaticoduodenal artery aneurysms in association with median arcuate ligament syndrome (MALS) are relatively rare. A treatment option, such as a median arcuate ligament (MAL) release or embolization of the aneurysms, should be considered in such cases, but the treatment criteria remain unclear. CASE REPORT: A 75-year-old man was transferred to our hospital because of a ruptured pancreaticoduodenal aneurysm. Emergency angiography showed stenosis of the root of the celiac axis (CA), a ruptured aneurysm of the posterior inferior pancreaticoduodenal artery (PIPDA), and an unruptured aneurysm of the anterior inferior pancreaticoduodenal artery (AIPDA). Coil embolization of the PIPDA was performed. Five days after embolization, the gallbladder became necrotic due to decreased blood flow in the CA region, and an emergency operation was performed. We performed a cholecystectomy and released the MAL to normalize the blood flow of the CA region. However, the patient died on postoperative day 8 because of rupture of the untreated aneurysm of the AIPDA. CONCLUSIONS: This is the first report of metachronous ruptures of multiple pancreaticoduodenal aneurysms due to MALS, even after a MAL release. Although rare, a residual aneurysm in the pancreatic head region may need to be embolized quickly.

Dual-energy bone removal computed tomography (BRCT): preliminary report of efficacy of acute intracranial hemorrhage detection.

PURPOSE: One of the major applications of dual-energy computed tomography (DECT) is automated bone removal (BR). We hypothesized that the visualization of acute intracranial hemorrhage could be improved on BRCT by removing bone as it has the highest density tissue in the head. This preliminary study evaluated the efficacy of a DE BR algorithm for the head CT of trauma patients. METHODS: Sixteen patients with acute intracranial hemorrhage within 1 day after head trauma were enrolled in this study. All CT examinations were performed on a dual-source dual-energy CT scanner. BRCT images were generated using the Bone Removal Application. Simulated standard CT and BRCT images were visually reviewed in terms of detectability (presence or absence) of acute hemorrhagic lesions. RESULTS: DECT depicted 28 epidural/subdural hemorrhages, 17 contusional hemorrhages, and 7 subarachnoid hemorrhages. In detecting epidural/subdural hemorrhage, BRCT [28/28 (100%)] was significantly superior to simulated standard CT [17/28 (61%)] (p = .001). In detecting contusional hemorrhage, BRCT [17/17 (100%)] was also significantly superior to simulated standard CT [11/17 (65%)] (p = .0092). CONCLUSION: BRCT was superior to simulated standard CT in detecting acute intracranial hemorrhage. BRCT could improve the detection of small intracranial hemorrhages, particularly those adjacent to bone, by removing bone that can interfere with the visualization of small acute hemorrhage. In an emergency such as head trauma, BRCT can be used as support imaging in combination with simulated standard CT and bone scale CT, although BRCT cannot replace a simulated standard CT.

Dual energy computed tomography for the head.

Dual energy CT (DECT) is a promising technology that provides better diagnostic accuracy in several brain diseases. DECT can generate various types of CT images from a single acquisition data set at high kV and low kV based on material decomposition algorithms. The two-material decomposition algorithm can separate bone/calcification from iodine accurately. The three-material decomposition algorithm can generate a virtual non-contrast image, which helps to identify conditions such as brain hemorrhage. A virtual monochromatic image has the potential to eliminate metal artifacts by reducing beam-hardening effects. DECT also enables exploration of advanced imaging to make diagnosis easier. One such novel application of DECT is the X-Map, which helps to visualize ischemic stroke in the brain without using iodine contrast medium.

A Novel Imaging Technique (X-Map) to Identify Acute Ischemic Lesions Using Noncontrast Dual-Energy Computed Tomography.

BACKGROUND: We evaluated whether X-map, a novel imaging technique, can visualize ischemic lesions within 20 hours after the onset in patients with acute ischemic stroke, using noncontrast dual-energy computed tomography (DECT). MATERIALS AND METHODS: Six patients with acute ischemic stroke were included in this study. Noncontrast head DECT scans were acquired with 2 X-ray tubes operated at 80 kV and Sn150 kV between 32 minutes and 20 hours after the onset. Using these DECT scans, the X-map was reconstructed based on 3-material decomposition and compared with a simulated standard (120 kV) computed tomography (CT) and diffusion-weighted imaging (DWI). RESULTS: The X-map showed more sensitivity to identify the lesions as an area of lower attenuation value than a simulated standard CT in all 6 patients. The lesions on the X-map correlated well with those on DWI. In 3 of 6 patients, the X-map detected a transient decrease in the attenuation value in the peri-infarct area within 1 day after the onset. CONCLUSIONS: The X-map is a powerful tool to supplement a simulated standard CT and characterize acute ischemic lesions. However, the X-map cannot replace a simulated standard CT to diagnose acute cerebral infarction.