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Purpose: To perform a retrospective outcomes analysis of central venous catheters with peripheral venous access ports, with comparison to published data.Methods: One hundred and twelve central venous catheters with peripherally placed access ports were placed under sonographic guidance in 109 patients over a 4-year period. Ports were placed for the administration of chemotherapy, hyperalimentation, long-term antibiotic therapy, gamma-globulin therapy, and frequent blood sampling. A vein in the upper arm was accessed in each case and the catheter was passed to the superior vena cava or right atrium. Povidone iodine skin preparation was used in the first 65 port insertions. A combination of Iodophor solution and povidone iodine solution was used in the last 47 port insertions. Forty patients received low-dose (1 mg) warfarin sodium beginning the day after port insertion. Three patients received higher doses of warfarin sodium for preexistent venous thrombosis. Catheter performance and complications were assessed and compared with published data.Results: Access into the basilic or brachial veins was obtained in all cases. Ports remained functional for a total of 28,936 patient days. The port functioned in 50% of patients until completion of therapy, or the patient's expiration. Ports were removed prior to completion of therapy in 18% of patients. Eleven patients (9.9% of ports placed) suffered an infectious complication (0.38 per thousand catheter-days)-in nine, at the port implantation site, in two along the catheter. In all 11 instances the port was removed. Port pocket infection in the early postoperative period occurred in three patients (4.7%) receiving a Betadine prep vs two patients (4.2%) receiving a standard O.R. prep. This difference was not statistically significant (p = 0.9). Venous thrombosis occurred in three patients (6.8%) receiving warfarin sodium and in two patients (3%) not receiving warfarin sodium. This difference was not statistically significant (p = 0.6). Aspiration occlusion occurred in 13 patients (11.7%). Intracatheter urokinase was infused in eight of these patients and successfully restored catheter function in all but two instances. These complication rates are comparable to or better than those reported with chest ports.Conclusion: Peripheral ports for long-term central venous access placed by interventional radiologists in the interventional radiology suite are as safe and as effective as chest ports. [ABSTRACT FROM AUTHOR]

For lack of other suitable access, 10 consecutive patients received paired hemodialysis catheters for long-term hemodialysis using a translumbar approach to the inferior vena cava (IVC). All attempts were successful. Five paired catheters were placed using the single-puncture technique, and five using the dual-puncture technique. Catheters were in place for a total of 2252 catheter days. The average duration of catheter placement was 250 days (range 30-580 days). All catheters were functioning up to the time the study was completed or the patient died. The most common complication was partial dislodgment of the catheter in 3 of 23 catheters (13%), all occurring in obese patients. One episode of retroperitoneal hemorrhage was noted in a patient having the single-access technique. There were no episodes of infection or IVC thrombosis. [ABSTRACT FROM AUTHOR]

Purpose: To assess how radiologic intervention altered the hospital course of patients undergoing continent urinary diversion.Methods: Thirty-seven consecutive patients with bladder cancer invading the muscular layer were treated with total cystectomy and construction of a continent urinary reservoir. Eleven of 37 patients suffered early and late anastomotic leakage; six had prolonged extraperitoneal leakage at the urethroenteric anastomosis, three had prolonged intraperitoneal pouch leaks, and two had delayed ureteroenteric leaks. Seven of these patients required radiologic intervention.Results: Intervention in the form of drainage catheter manipulation (n = 4), percutaneous nephrostomy (n = 4), or ureteral stent placement (n = 2) resulted in cessation of leakage without surgical intervention in all seven patients. Intraperitoneal pouch leaks were more difficult to control than extraperitoneal leakage and required longer drainage intervals.Conclusion: Interventional radiologic procedures played a key role in the management of continent urinary diversion complications, obviating the need for repeat surgical intervention in all instances. [ABSTRACT FROM AUTHOR]

We describe a technique for gaining access to the central collecting system via a chosen calyx, utilizing an alternative entry point to that calyx. An Amplatz nitinol loop snare is then used to convert this access to a traditional approach. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effect of selective blockade of type B cholecystokinin receptors on gall bladder contraction in normal humans and to compare methods for quantitative analysis of gall bladder contraction. Methods: L-365,260, a novel, nonpeptide cholecystokinin antagonist shown to be selective for type B cholecystokinin receptors, was administered every 6 h over a 5--7-day period. Plasma levels of L-365,260 were determined by high pressure liquid chromatography. Gallbladder contraction after a standardized fatty meal was measured by ultrasonography, and results were calculated by ellipsoid or sum of cylinders methods. Results: L-365,260 levels were comparable to levels in earlier studies demonstrating inhibition of pentagastrin-stimulated acid secretion in normal subjects and blockade of anxiogenic effects of cholecystokinin injections in patients with panic disorder. Regardless of the method used for estimating gallbladder size, none of the L-365,260 doses studied inhibited gallbladder contraction, gallbladder size was most consistently estimated by the ellipsoid method using measurements normalized to individual values for minimum and maximum gallbladder dimensions. Conclusions: Multiple oral doses of L-365,260 do not alter ultrasonographically assessed gallbladder contraction at doses shown to be clinically effective in earlier studies. Despite being more difficult to implement, the sum of cylinders method for estimating gall bladder size offers no advantage over the ellipsoid method. [ABSTRACT FROM AUTHOR]

We describe successful transcatheter occlusion of a mycotic renal artery aneurysm. The patient's hypertension resolved following occlusion of the aneurysm and infarction of the renal parenchyma in the distribution of the aneurysmal vessel. [ABSTRACT FROM AUTHOR]

Introduction: Cholecystectomy (CCY) is the gold standard treatment of acute cholecystitis (AC). Nonsurgical management of AC includes percutaneous transhepatic gallbladder drainage (PT-GBD) and endoscopic ultrasound-guided gallbladder drainage (EUS-GBD). This study aims to compare outcomes of patients who undergo CCY after having received EUS-GBD vs PT-GBD., Methods: A multicenter international study was conducted in patients with AC who underwent EUS-GBD or PT-GBD, followed by an attempted CCY, between January 2018 and October 2021. Demographics, clinical characteristics, procedural details, postprocedure outcomes, and surgical details and outcomes were compared., Results: One hundred thirty-nine patients were included: EUS-GBD in 46 patients (27% male, mean age 74 years) and PT-GBD in 93 patients (50% male, mean age 72 years). Surgical technical success was not significantly different between the 2 groups. In the EUS-GBD group, there was decreased operative time (84.2 vs 165.4 minutes, P < 0.00001), time to symptom resolution (4.2 vs 6.3 days, P = 0.005), and length of stay (5.4 vs 12.3 days, P = 0.001) compared with the PT-GBD group. There was no difference in the rate of conversion from laparoscopic to open CCY: 5 of 46 (11%) in the EUS-GBD arm and 18 of 93 (19%) in the PT-GBD group ( P value 0.2324)., Discussion: Patients who received EUS-GBD had a significantly shorter interval between gallbladder drainage and CCY, shorter surgical procedure times, and shorter length of stay for the CCY compared with those who received PT-GBD. EUS-GBD should be considered an acceptable modality for gallbladder drainage and should not preclude patients from eventual CCY., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

While the gold-standard for management of localized renal cell carcinoma (RCC) is partial nephrectomy, recent ablative strategies are emerging as alternatives with comparable rates of complications and oncologic outcomes. Thermal ablation, in the form of radiofrequency ablation and cryoablation, is being increasingly accepted by professional societies, and is particularly recommended in patients with a significant comorbidity burden, renal impairment, old age, or in those unwilling to undergo surgery. Maturation of long-term oncologic outcomes has further allowed increased confidence in these management strategies. New and exciting ablation technologies such as microwave ablation, stereotactic body radiotherapy, and irreversible electroporation are emerging. In this article, we review the existing management options for localized RCC, with specific focus on the oncologic outcomes associated with the various ablation modalities., Competing Interests: The authors declare no potential conflicts of interest with respect to research, authorship, and/or publication of this article., (Copyright: Leopold Z, et al.)

Purpose: To describe a previously unreported anatomical variant of the hepatic arterial supply: a conjoined right hepatic artery, formed by branches of the common hepatic artery and gastroduodenal artery., Method: A 54-year-old female with oligometastatic colorectal cancer with metastases to the liver presented for planning stage arteriography in preparation for Y90 radioembolization., Results: Arteriography of the common hepatic artery demonstrated bifurcation into a right hepatic artery and gastroduodenal artery. The gastroduodenal artery gave rise to a proximal branch, from which the left hepatic artery originated and then continued to anastomose in the hilum of the liver to the right hepatic artery originating from the common hepatic artery. It was initially identified on visceral artery arteriography and then retrospectively recognized on pre-procedural CT scan., Conclusion: Anatomical variants of the hepatic arterial supply are important to recognize during planning stage arteriography in preparation for Y90 radioembolization. Knowledge of these variants is also important for pre-operative planning., (© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

Purpose: Recently, the outbreak of the novel coronavirus disease 2019 (COVID-19) pandemic has seriously endangered human health and life. In fighting against COVID-19, effective diagnosis of infected patient is critical for preventing the spread of diseases. Due to limited availability of test kits, the need for auxiliary diagnostic approach has increased. Recent research has shown radiography of COVID-19 patient, such as CT and X-ray, contains salient information about the COVID-19 virus and could be used as an alternative diagnosis method. Chest X-ray (CXR) due to its faster imaging time, wide availability, low cost, and portability gains much attention and becomes very promising. In order to reduce intra- and inter-observer variability, during radiological assessment, computer-aided diagnostic tools have been used in order to supplement medical decision making and subsequent management. Computational methods with high accuracy and robustness are required for rapid triaging of patients and aiding radiologist in the interpretation of the collected data., Method: In this study, we design a novel multi-feature convolutional neural network (CNN) architecture for multi-class improved classification of COVID-19 from CXR images. CXR images are enhanced using a local phase-based image enhancement method. The enhanced images, together with the original CXR data, are used as an input to our proposed CNN architecture. Using ablation studies, we show the effectiveness of the enhanced images in improving the diagnostic accuracy. We provide quantitative evaluation on two datasets and qualitative results for visual inspection. Quantitative evaluation is performed on data consisting of 8851 normal (healthy), 6045 pneumonia, and 3323 COVID-19 CXR scans., Results: In Dataset-1, our model achieves 95.57% average accuracy for a three classes classification, 99% precision, recall, and F1-scores for COVID-19 cases. For Dataset-2, we have obtained 94.44% average accuracy, and 95% precision, recall, and F1-scores for detection of COVID-19., Conclusions: Our proposed multi-feature-guided CNN achieves improved results compared to single-feature CNN proving the importance of the local phase-based CXR image enhancement. Future work will involve further evaluation of the proposed method on a larger-size COVID-19 dataset as they become available.

We report a rare variant in mesenteric arterial anatomy: replacement of the right hepatic and common hepatic arteries to the SMA in a patient treated for hepatocellular carcinoma. The potential clinical implications of this unusual variation of celiaco-mesenteric anatomy will be discussed.

Objectives: The survival of patients with metastatic colorectal cancer (CRC) has been increasing over recent decades due to improvements in chemotherapy and surgery. There is a need to refine prognostic information to more accurately predict survival as patients survive for any given length of time to assist multidisciplinary cancer management teams in treatment decisions., Materials and Methods: We performed a single center retrospective analysis of patients treated with metastatic CRC (unresectable and resectable) who survived >24 months between 2005 and 2015 (N=155). Patient tumor and treatment related variables were collected. Overall survival (OS) estimates conditional on surviving >24 months were compared with actuarial survival estimates of a cohort of patients (33,104 resected, 39,382 unresected) from the National Cancer Database (NCDB)., Results: With a median follow-up of 44.2 months, the median OS of resected patients (n=86) was not reached. The median OS of unresected patients was 75.9 months. The conditional survival probabilities of living 1, 2, or 3 years longer after 24 months of survival are 92%, 72%, and 52%, respectively, in unresectable patients and 98%, 92%, and 89% in patients who were resected. The corresponding NCDB 1, 2, and 3 year actuarial survival was 38%, 20%, and 11% for unresected patients and 68%, 46%, and 32% for resected., Conclusions: These results indicate that CRC patients who survive 24 months with metastatic colorectal cancer have an excellent prognosis and surgery may be appropriate in a subset of patients initially deemed unresectable.

The purpose of this study is to determine if sequential interventional therapy can become a mainstay option in providing palliation from fastidious osseous neoplasms in patients with pain refractory to oral analgesia and radiotherapy. This retrospective monocentric study was approved by our institutional review board. Between July 2012 and August 2014, we reviewed 15 patients (6 women, 9 men; age range of 36-81 years) who underwent embolization followed by cryoablation, with or without osteoplasty. Patient demographics and tumor characteristics, including primary histology and the location of metastasis, were included in our review. Pain intensity at baseline, after radiotherapy, and after sequential interventional therapy was reviewed using the hospital electronic medical record. The use of oral analgesia and procedural complications was also noted. Data was then assessed for normality and a two-tailed Student's t -test was performed on mean pain scores for difference phases of treatment. While radiotherapy offers pain relief with a mean pain score of 7.25 ±1.5 (p =<.0001), sequential interventional therapy results in better comfort as demonstrated by a mean pain score of 3.9 ± 2.6 (p=.0015). Moreover, all patients who reported oral analgesic use at presentation reported a decrease in their requirement after sequential interventional therapy. Embolization and cryoablation were performed in all patients, while osteoplasty was indicated in 6 cases. There was no difference in postprocedural pain intensity between patients who required osteoplasty and patients who did not (p = 0.7514). There were no complications observed during treatment. This retrospective study shows that sequential intervention with transarterial embolization, cryoablation, and osteoplasty is both safe and efficacious for bone pain refractory to the current standard of care. We demonstrated that this combination therapy has the potential to become an effective mainstay treatment paradigm in the palliative care of osseous neoplasm to improve quality of life.

Hepatic arterial infusion pumps are increasingly utilized as an option for liver directed therapy in the treatment of metastatic colorectal carcinoma. After skeletonization of the hepatic artery through the ligation of extra-hepatic branches, these pumps are implanted surgically with their tip placed in the common hepatic artery. Subsequently, a nuclear medicine pump study is performed to ensure homogeneous perfusion of the liver and detect any extrahepatic perfusion. We report a peripheral arc between the superior mesenteric artery and celiac axis, which caused misperfusion on the SPECT nuclear medicine scan.

Objective: As the utility of Child-Pugh (C-P) class is limited by the subjectivity of ascites and encephalopathy, we evaluated a previously established objective method, the albumin-bilirubin (ALBI) grade, as a prognosticator for yttrium-90 radioembolization (RE) treatment for patients with hepatocellular carcinoma (HCC)., Materials and Methods: A total of 117 patients who received RE for HCC from 2 academic centers were reviewed and stratified by ALBI grade, C-P class, and Barcelona Clinic Liver Cancer stage. The overall survival (OS) according to these 3 criteria was evaluated by Kaplan-Meier survival analysis. The utilities of C-P class and ALBI grade as prognostic indicators were compared using the log-rank test. Multivariate Cox regression analysis was performed to identify additional predictive factors., Results: Patients with ALBI grade 1 (n=49) had superior OS than those with ALBI grade 2 (n=65) (P=0.01). Meanwhile, no significant difference was observed in OS between C-P class A (n=100) and C-P class B (n=14) (P=0.11). For C-P class A patients, the ALBI grade (1 vs. 2) was able to stratify 2 clear and nonoverlapping subgroups with differing OS curves (P=0.03). Multivariate Cox regression test identified alanine transaminase, Barcelona Clinic Liver Cancer stage, and ALBI grade as the strongest prognostic factors for OS (P<0.10)., Conclusions: ALBI grade as a prognosticator has demonstrated clear survival discrimination that is superior to C-P class among HCC patients treated with RE, particularly within the subgroup of C-P class A patients. ALBI grade is useful for clinicians to make decisions as to whether RE should be recommended to patients with HCC.

Opinion Statement: Patients with unresectable hepatic colorectal metastases who become chemo-refractory have limited treatment options. Systemic chemotherapies such as TAS102 and regorafenib have been used in the refractory setting, but with only modest improvement in overall survival compared to best supportive care. In patients with liver-only or liver-dominant disease, direct chemotherapy to the liver such as hepatic artery infusional (HAI) chemotherapy and radioembolization (yttrium-90 (Y90)) should be considered. Due to the difficulty of HAI therapy post Y90 for technical reasons, we recommend HAI therapy prior to Y90.

Background: Angiography allows for excellent characterization and treatment of traumatic pseudoaneurysms. However, ultrasound-guided thrombin injection for pseudoaneurysm thrombosis allows for radiation-free treatment of superficial pseudoaneurysms and superficial expanding hematomas., Methods: A retrospective review of 5 patient cases treated under this paradigm was performed following institutional review board approval. Outcomes following intervention were recorded and compared amongst the patient cohort., Results: Ultrasound-guided closure of traumatic pseudoaneurysms allowed for reduced procedural times and procedural invasiveness., Conclusions: As demonstrated by the following cases, ultrasound guided thrombin injection is a good method of primary treatment for superficial pseudoaneurysms, or as an alternative treatment in cases where transcatheter embolization fails.

A 64-year-old woman with a completely transected posterior sectoral duct following extended hepatectomy underwent a combined operative procedure with interventional radiology and surgery to restore biliary-enteric drainage. The anterior and posterior sectoral ducts were identified, and catheters were inserted into both systems. The posterior sectoral catheter was placed intraoperatively through a preoperatively placed sheath, and a new tunnel was created through the regenerated liver surface. Biliary-enteric anastomoses were created over the stents.

Dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) of the breast has emerged as an adjunct imaging tool to conventional X-ray mammography due to its high detection sensitivity. Despite the increasing use of breast DCE-MRI, specificity in distinguishing malignant from benign breast lesions is low, and interobserver variability in lesion classification is high. The novel contribution of this paper is in the definition of a new DCE-MRI descriptor that we call textural kinetics, which attempts to capture spatiotemporal changes in breast lesion texture in order to distinguish malignant from benign lesions. We qualitatively and quantitatively demonstrated on 41 breast DCE-MRI studies that textural kinetic features outperform signal intensity kinetics and lesion morphology features in distinguishing benign from malignant lesions. A probabilistic boosting tree (PBT) classifier in conjunction with textural kinetic descriptors yielded an accuracy of 90%, sensitivity of 95%, specificity of 82%, and an area under the curve (AUC) of 0.92. Graph embedding, used for qualitative visualization of a low-dimensional representation of the data, showed the best separation between benign and malignant lesions when using textural kinetic features. The PBT classifier results and trends were also corroborated via a support vector machine classifier which showed that textural kinetic features outperformed the morphological, static texture, and signal intensity kinetics descriptors. When textural kinetic attributes were combined with morphologic descriptors, the resulting PBT classifier yielded 89% accuracy, 99% sensitivity, 76% specificity, and an AUC of 0.91.

This paper introduces a non-rigid registration approach for tracking tumor response to radiofrequency ablation (RFA) across consecutive imaging studies. The method described here exploits the combined power of global and local alignment of pre- and post-treatment CT liver images for a given patient. The distinguishing characteristics of the system is that it can infer volumetric deformation based upon surface displacements using a linearly elastic finite element model (FEM). This technique may provide valuable information that could be beneficial in a range of surgical interventions as well as for the purposes of monitoring tissue response and therapy planning.

Objective: At many academic institutions, preliminary interpretations of CT scans and sonograms obtained after regular hours of operation are performed by radiology residents, with attending radiologists reviewing the interpretations the next morning. We sought to determine the rate of discrepancy between residents' interpretations of imaging studies and the final interpretations performed by an attending body imaging radiologist as well as any resulting clinical consequences stemming from the discrepancies. Therefore, we reviewed 928 CT and sonographic images that had been obtained after hours at a level 1 trauma center during a 6-month period., Materials and Methods: Any discrepancies between the preliminary and final interpretations were judged as either major (i.e., necessitating an urgent change in treatment) or minor errors. We conducted patient follow-up via a retrospective review of the medical charts to determine whether any of the discrepancies led to additional imaging, an increase in patient morbidity, an extension of a hospital stay, or a change in treatment., Results: The overall discrepancy rate in interpretations rendered by the residents and those performed by the attending radiologist was 3.8%, with most of these discrepancies (86%) judged to be minor. If we combined the data for body CT scans and sonograms, the rate of minor discrepancies was 3.2%, and the rate of major discrepancies was 0.5%. If we considered only body CT data in the evaluation, the overall discrepancy rate increased to 6.4%, with a 5.4% rate of minor discrepancies and a 1.0% rate of major discrepancies., Conclusion: Our evaluation of discrepancy rates was unusual in that we included interpretations of sonograms, on which residents and the attending radiologist had a higher rate of agreement (99.5%). Because of the high agreement in the interpretation of sonograms, the overall discrepancy rate was 3.8%. However, if only body CT scan interpretations were evaluated, our results were closer to the rates reported in previously published studies. Major discrepancies led to a change in patient treatment but did not lead to any increase in patient morbidity or to any quantifiable increase in the length of the hospital stay.

Purpose: To evaluate the feasibility and complications of placement of a low-profile venous access port in the chest in children requiring long-term venous access., Method: A low-profile peripheral arm port (PAS port; Sims Deltec, St. Paul, MN, USA) was implanted in the chest in 22 children over a 4-year period. The mean age of the study group was 6 years (range: 9 months to 20 years). Ports were placed for the administration of chemotherapy, hyperalimentation and frequent blood sampling. Sonographic guidance was used to access the internal jugular or subclavian vein in each case. A review of all inpatient and outpatient charts was undertaken to assess catheter performance and complications., Results: Access to the central venous circulation was successfully achieved in each case without complication. Ports remained implanted for 6579 catheter-days (mean: 299 days). Ten ports have been removed. Of three patients (13%) experiencing device-related infections (0.45 infections/1000 catheter days), two (9.1%) were unresponsive to antibiotics and removed (0.3 infections/1000 catheter days). One port was removed because of pain in the shoulder adjacent to the port implantation site. One port was removed because of difficult access. The final port was removed in order to place a dual-lumen catheter prior to bone marrow transplant. Twelve ports remain implanted. Aspiration occlusion occurred in four patients (18%). Deep venous thrombosis did not occur in any patient., Conclusion: Low-profile chest ports placed by interventional radiologists in the interventional radiology suite can be placed in children as safely as traditional chest ports placed in the operating room. The incidence of infection, venous thrombosis and aspiration occlusion is comparable to that of ports placed operatively.

Objective: To determine what symptoms of leiomyomata uteri prompted women to seek uterine artery embolization (UAE) and what factors were most frequently cited in the decision making leading to choosing UAE over other treatments., Study Design: Eighty-four consecutive women with symptomatic leiomyoma presenting for UAE completed a questionnaire that inquired about their pelvic symptoms and the issues that were important in their decision to request UAE. All subjects previously had been told that they were surgical candidates., Results: Pelvic symptoms that the 84 women most frequently noted were bleeding (n = 61), anemia (41), pelvic pain (29), frequent urination (24) and pelvic pressure (21). The majority of women (78) reported significant worry about their health from the fibroids, and (72) reported that the symptoms caused daily discomfort. Although the majority of women wanted a treatment that would give permanent relief of symptoms and thought UAE would do this, other factors frequently cited in the decision making included quality-of-life reasons, such as the desire to avoid adverse effects of other treatments (76), anticipated prolonged postoperative recovery from surgery (70) and avoiding surgery (66). Many women considered the uterus an important female organ, believed that the uterus was a source of femininity (33), stated that the uterus was necessary to maintain self-image (49) and reported that the uterus was necessary to maintain sexual image (49)., Conclusion: In this cohort of women with symptomatic leiomyomas, treatment preferences did not interfere with the current lifestyle. In addition, the uterus was considered a source of femininity and sexuality. It is not clear whether women requesting UAE differ from women requesting surgical intervention in terms of how they assess the importance of the uterus, but these data suggest that many women still consider the uterus an important aspect of their femininity and that those seeking nonsurgical options should be thoroughly counseled about uterine function and how it relates to sexuality.

Rational and Objectives: The purpose of this study was to evaluate the effects of variation in design parameters on the resultant radial force. We evaluated the influence of wire gauge, leg length, and number of bends on the radial force produced by z stents and compared these with radial forces produced by commercial stents. A second goal was to develop an engineering model for predicting radial forces generated by z stents., Methods: Z stents were fashioned by hand using stainless steel wire and solder that connected the ends. The radial force was measured as a function of wire gauge, vessel diameter, leg length, and number of bends and compared with the theoretical values of radial force calculated by combining Castigliano's theorem and the law of Laplace., Results: Theoretically predicted radial forces were within 8% of each observed value of radial force up to 70% spring compression., Conclusions: These results suggest that the z-stent model can be used to build custom stents with preselected values of radial force for clinical use. In addition, they can be used to design model investigational stents made of similar materials and surface areas to test the effects of radial force on biological response.

We describe the first case of an ureteroarterial fistula developing after orthotopic neobladder substitution and its minimally invasive management using endovascular stent grafting. We outline the risk factors for the development of ureteroarterial fistulae and trace the evolution of diagnostic and therapeutic modalities used in the management of these life-threatening complications. Minimally invasive management with endovascular stent grafting and exclusion of two pseudoaneurysms in the iliac artery system was performed successfully. After successful endovascular exclusion of two pseudoaneurysms, the patient's hematuria resolved and he recovered fully. Three-dimensional computed tomography performed 3 months later documented a patent aortoiliac arterial system without evidence of pseudoaneurysm or endovascular leak. Ureteroarterial fistula after orthotopic bladder substitution was managed with an endovascular stent graft without the need for extra-anatomical vascular bypass. Early recognition, stabilization, and angiographic evaluation followed by this minimally invasive technique may avoid open operative repair and attendant morbidity.

Thrombolysis for the treatment of occluded bypass grafts is used in selected clinical circumstances. Unfortunately, a minority of these procedures are technical failures because of the inability to access the occluded graft. We describe a technique that greatly increases the chances of technical success.