Transplant Renal Interventions.

Renal transplantation is the most commonly performed solid-organ allograft surgery; in 2021, 25487 kidneys were transplanted in the United States, and nearly 42,000 adult patients were listed for transplant. As the treatment of choice for patients with end-stage renal disease, transplantation is performed at more than 250 centers. Despite a high rate of success, renal transplantation is not without complication, and the interventional radiologist plays a crucial role in the management of the postoperative patient. Knowledge of postsurgical anatomy, imaging findings, and technical challenges unique to these patients is important for the safe and effective treatment of transplant-related conditions. We offer a guide to the most common interventions in the renal transplant population, including biopsy, vascular interventions, and the management of urinary obstruction.

Surgical resection criteria and neoadjuvant therapies for intrahepatic cholangiocarcinoma.

The staging of intrahepatic cholangiocarcinoma (ICC) is complex, and there is no consensus among international cancer groups on how to most appropriately select candidates with nonmetastatic disease for surgical resection. Factors contributing to a higher stage of disease include larger tumor size, multiple tumors, vascular invasion (either portal venous or arterial), biliary invasion, involvement of local hepatic structures, serosal invasion, and regional lymph node metastases. For patients selected to undergo surgery, it is well-documented that R0 resection translates to a survival benefit. Estimating the risk of post-hepatectomy liver failure and post-surgical residual liver function is vital and may preclude some patients with significant tumor burden from undergoing surgery. Numerous serum and biliary biomarkers of the disease can help detect recurrence in patients undergoing surgical resection. Systemic and locoregional neoadjuvant treatments to facilitate better surgical outcomes have yielded mixed results regarding improving resectability and overall survival. Additional research is needed to identify optimal neoadjuvant treatment approaches and to evaluate which patients will benefit most from these strategies. Therapies targeting genetic mutations and protein aberrations found by tumor molecular profiling may offer additional options for future neoadjuvant treatment.

Safety and Feasibility of Gun-Sight Technique for Transjugular Intra-hepatic Portosystemic Shunt (TIPS) Creation.

PURPOSE: To review technical details, indications for use, success rates and complications of gun-sight technique for transjugular intra-hepatic portosystemic shunt (TIPS) creation. MATERIALS AND METHODS: A multicenter retrospective review was performed. Forty-two TIPS procedures with gun-sight technique were identified between 2016 and 2021. Eighty-six percent of patients had portal vein thrombosis (PVT), and 21% had undergone prior failed TIPS creation. Demographics, procedure details and outcomes were reviewed. Differences between the groups, event rates and patency rates were evaluated using nonparametric two-sample Wilcoxon rank-sum (Mann-Whitney) test, Fisher's exact test, Kaplan-Meier curves, and log-rank test. RESULTS: Technical success was 98%. Sixty-seven percent of subjects had transsplenic and 26% had transhepatic access for TIPS creation. Twenty-one adverse events were noted (48%), four of which were definitely related and four were probably related to the use of gun-sight technique. Early (within 90 days) thrombosis occurred in 7/41 patients (17%), all of whom had existing PVT. CONCLUSION: Gun-sight technique for TIPS creation has a high success rate in this challenging cohort of patients. While complications can occur, most of the adverse events noted were likely associated with TIPS creation itself rather than gun-sight. Early thrombosis only occurred in patients with PVT. Level of Evidence Level 4, Case Series.

Systemic Treatment for Advanced Hepatocellular Carcinoma.

BACKGROUND: Patients with advanced hepatocellular carcinoma (HCC) have a poor prognosis. First-line sorafenib has been the standard of care for a decade, but the treatment landscape is expanding. This review provides a practical overview of current and future systemic treatment options for advanced HCC and their place in clinical practice. SUMMARY: First-line sorafenib and lenvatinib have shown to improve the survival of patients with advanced HCC. In the second line, regorafenib provides benefit for patients who previously tolerated sorafenib. Anti-PD1 antibodies, nivolumab and pembrolizumab, recently became available for second-line use in the US. Ramucirumab (for patients with α-fetoprotein [AFP] levels ≥400) and cabozantinib present potential future second-line treatment options. Combinations of systemic and locoregional treatment, such as radiofrequency ablation or selective internal radiotherapy, require further research. Precision medicine has not yet been translated into clinical practice, as the most common driver mutations (TERT promoter, CTNNB1, TP53, and ARID1A mutations) have not yet been shown to be suitable therapeutic targets. However, our growing understanding of signaling pathways and efforts in drug development are expected to pave the way for precision medicine in HCC in the future. Evaluating the place for the current and novel systemic treatment options in clinical practice can be challenging due to the diverse toxicity profiles of the treatment options and characteristics of the patient population. Sorafenib data elucidate the effect patient characteristics (such as the performance score, Child-Pugh class, AFP, etiology of the underlying disease, and level of macrovascular invasion and extrahepatic spread) may have on outcomes in advanced stages. KEY MESSAGES: Lenvatinib is expected to join sorafenib as a preferred first-line treatment in advanced HCC. In the second line, the treatment of choice, regorafenib, is soon expected to be accompanied by cabozantinib and ramucirumab in patients with AFP ≥400 ng/mL, whereas nivolumab and pembrolizumab present second-line alternatives in the US.

Bridging Hepatocellular Carcinoma to Transplant: Transarterial Chemoembolization Response, Tumor Biology, and Recurrence after Transplantation in a 12-Year Transplant Cohort.

PURPOSE: To evaluate tumor response to transarterial chemoembolization as well as biologic characteristics of the tumor as predictors of recurrence after transplantation in patients with hepatocellular carcinoma (HCC) who were bridged or down-staged to liver transplantation. MATERIALS AND METHODS: An institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, single-institution retrospective analysis was performed on all patients with HCC who were treated with the use of conventional transarterial chemoembolization or transarterial chemoembolization with drug-eluting embolics (DEE) over a 12-year period and who subsequently underwent liver transplantation (n = 142). Treatment response was based on modified Response Evaluation Criteria in Solid Tumors (mRECIST) imaging criteria and then correlated with tumor characteristics and recurrence. Of the 142 patients followed after transplantation, 127 had imaging after transarterial chemoembolization but before transplantation. Imaging response and post-transplantation recurrence were correlated with patient demographics, liver function, and tumor morphology. HCC recurred in 9 patients (mean time from transplantation, 526 days). Recurrence was analyzed with the use of univariate and multivariate statistics. Kaplan-Meier recurrence-free survival curves were calculated based on immediate imaging response before transplantation with the use of the log-rank test. RESULTS: Before transplantation, 57% of patients (72/127) demonstrated complete response (CR) and 24% (31/127) showed partial response (PR). Complete pathologic necrosis occurred in 54% (39/72) of CR patients and 20% (6/31) of PR patients. Poor treatment response, defined as stable disease (SD) or progressive disease (PD), occurred in 18% of patients (24/127) before transplantation and was present in 67% of cases of recurrence (6/9; P < .001). Post-transplantation recurrence was present in 1.4% of patients (1/71) with CR and in 6.5% of patients (2/31) with PR. In patients with SD after transarterial chemoembolization, HCC recurred in 18.8% of transplant patients (3/16) and in 43% of patients (3/7) with PD. Larger pretreatment tumor size (P = .05), higher Child-Pugh score (P = .002), higher tumor grade at explantation (P = .04), and lymphovascular invasion at explantation (P = .008) also were associated with increased incidence of post-transplantation recurrence. CONCLUSIONS: Poor tumor response to transarterial chemoembolization before transplantation identifies patients at increased risk for post-transplantation recurrence.

Comparison of Cone-Beam Tomography and Cross-Sectional Imaging for Volumetric and Dosimetric Calculations in Resin Yttrium-90 Radioembolization.

PURPOSE: To compare the use of cone-beam computed tomography versus contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) in the calculation of liver volume and planned dose for yttrium-90 radioembolization. MATERIALS AND METHODS: The study retrospectively assessed 47 consecutive patients who underwent resin Y-90 radioembolization consecutively over a 2-year period at a single center. Volume calculation software was used to determine perfused lobar liver volumes from cone-beam CT (CBCT) images obtained during mapping angiography. CBCT-derived volumes were compared with perfused lobar volume derived from contrast-enhanced CT and MRI. Nominal activities as determined by the SIR-Spheres Microspheres Activity Calculator were similarly calculated and compared using both CBCT and conventionally acquired volumes. RESULTS: A total of 82 hepatic lobes were assessed in 47 patients. The mean percentage difference between combined CT-MRI- and CBCT-derived calculated lobar volumes was 25.3% (p = 0.994). The mean percentage difference in calculated dose between the two methods was 21.8 ± 24.6% (p = 0.42). Combined left and right lobar CT-derived dose difference was less than 10% in 22 lobes, between 10 and 25% in 20 lobes, between 25 and 50% in 13 lobes and greater than 50% in 5 lobes. Combined left and right lobar MRI-derived dose difference was less than 10% in 11 lobes, between 10 and 25% in 7 lobes, between 25 and 50% in 2 lobes and greater than 50% in 1 lobe. CONCLUSIONS: Although volume measurements derived from CT/MRI did not differ significantly from those derived from CBCT, variability between the two methods led to large and unexpected differences in calculated dose.

Technology of irreversible electroporation and review of its clinical data on liver cancers.

INTRODUCTION: Irreversible electroporation (IRE) has developed as a novel percutaneous ablative technique over the past decade and its utility in the treatment of primary and metastatic liver disease has progressed rapidly. AREAS COVERED: After discussing the principles behind the technology and the practical steps in its use, this article offers a detailed analysis of the recent published work that evaluates its safety and efficacy. The strengths and weaknesses of other ablative techniques, including radiofrequency ablation, microwave ablation and cryoablation, are discussed in detail. Other aspects of IRE, including post-treatment clinical follow-up, expected imaging findings, and the most frequently encountered complications, are covered. Finally, the future of IRE is examined as it pertains to advancements in the treatment of hepatic malignancy. EXPERT COMMENTARY: The characteristics of IRE that make this technology uniquely suited for the treatment of liver tumors have allowed it to gain a significant foothold in interventional oncology. Continued development of IRE will lead to further advances in the management of previously untreatable liver cancers.

Success Rate and Complications of Sharp Recanalization for Treatment of Central Venous Occlusions.

PURPOSE: To evaluate success and safety of needle (sharp) recanalization as a method to re-establish access in patients with chronic central venous occlusions. MATERIALS AND METHODS: Thirty-nine consecutive patients who underwent this procedure were retrospectively reviewed to establish success rate and associated complications. In all cases, a 21- or 22-gauge needle was used to restore connection between two chronically occluded segments after conventional wire and catheter techniques had failed. The needle was guided toward a target placed through a separate access by fluoroscopic guidance. When successful, the procedure was completed by placing a catheter, ballooning the segment, and/or stenting. RESULTS: The procedure was successful in 37 of the 39 patients (95%). The vast majority of the treated lesions were in the SVC and/or right innominate vein. Occlusions ranged in length between 10 and 110 mm, and the average length of occluded venous segment was 40 mm in the treated group. There were four minor (SIR classification B) complications involving pain management after the procedure. There were two major (SIR classification D) complications both of which involved hemorrhage into the pericardium treated with covered stents (5.1%). CONCLUSIONS: Sharp recanalization is a viable procedure for patients who have exhausted standard wire and catheter techniques. The operator performing this procedure should be familiar with potential complications so that they can be addressed urgently if needed.

Predicting abdominal closure after component separation for complex ventral hernias: maximizing the use of preoperative computed tomography.

BACKGROUND: Component separation techniques (CSTs) have allowed for midline fascial reapproximation in large midline ventral hernias. In certain cases, however, fascial apposition is not feasible, resulting in a bridged repair that is suboptimal. Previous estimates on myofascial advancement are based on hernia location and do not take into account variability between patients. Examination of preoperative computed tomography (CT) may provide insight into these variabilities and may allow for prediction of abdominal closure with CST. STUDY DESIGN: A retrospective review was conducted of patients who underwent abdominal wall reconstruction from 2007 to 2012 with CST. Preoperative CT was obtained, and specific parameters were analyzed using image analysis software. Logistic regression was used to predict ideal operative closure. Multivariate analyses were adjusted for age and sex. An a priori value was set at P < 0.05. RESULTS: Fifty-four patients met the criteria and had preoperative CT available for analysis. Forty-eight patients had fascial reapproximation achieved, whereas 6 patients had a bridged repair. Age, sex, weight, and body mass index were similar between groups (P > 0.05). Significant differences were seen between groups in 3 variables: transverse defect size (19.8 vs 10 cm, P < 0.05), defect area (420 vs 184.2 cm, P < 0.05), and percent abdominal wall defect (18.9% vs 10.6%, P < 0.05). CONCLUSIONS: Preoperative determination of abdominal wall defect ratios and hernia defect areas may represent a more accurate method to predict abdominal wall closure after CST. Predicting midline approximation after CST is critical because outcomes after bridged repair can result in higher recurrence rates.

Computerized tomographic and magnetic resonance angiography for perforator-based free flaps: technical considerations.

Perforator-based free flaps rely on the appropriate dominant vessel supplying the vascular territory of the flap. Preoperative knowledge of the vascular anatomy can improve outcome and diminish surgical time. Several preoperative imaging techniques exist for surgical planning. Computed tomographic and magnetic resonance angiography are two emerging modalities that provide exceptional anatomic detail. Despite the growing utilization of cross-sectional imaging for preoperative planning, each modality has specific technical considerations that are necessary to consider in order to produce a quality study.

Cross-sectional, prospective study of MRI reproducibility in the assessment of plaque burden of the carotid arteries and aorta.

BACKGROUND: The reliability of imaging techniques to assess early atherosclerosis remains unclear. We did a cross-sectional, prospective study to test reproducibility of MRI when imaging arteries, to assess risk of cardiovascular disease and correlations with age and sex. METHODS: Between January 2003 and December 2006 we performed black-blood MRI of both common carotid arteries and the thoracic descending aorta in patients with cardiovascular risk factors who were referred from clinics in New York, NY, USA. Mean wall area, wall thickness, lumen area, total vessel area, and ratio of the mean wall area to the mean total vessel area (WA/TVA) were manually measured. Reproducibility within and between readers was tested on subsets of images from randomly chosen patients. RESULTS: MRI was performed on 300 patients. Intrareader reproducibility, assessed in images from 20 patients, was high for all parameters (intraclass correlation coefficients >0.8), except WA/TVA ratio in the descending aorta. The inter-reader reproducibility, assessed in images from 187 patients, was acceptable (intraclass correlation coefficients >0.7) for the mean wall, lumen, and total vessel areas. Values for all MRI parameters in all vessels increased with increasing age for both sexes (all P <0.0005) but were always significantly higher in men than in women, except for aortic mean wall thickness and WA/TVA ratio in the carotid arteries. Mean wall area values correlated well between the carotid arteries and aorta, reflecting the systemic nature of atherosclerosis. CONCLUSIONS: Our findings support MRI as a reproducible measurement of plaque burden and demonstrate the systemic distribution of atherosclerosis.

MRI estimation of total renal volume demonstrates significant association with healthy donor weight.

PURPOSE: The purpose of this study was to correlate total renal volume (TRV) calculations, obtained through the voxel-count method and ellipsoid formula with various physical characteristics. MATERIALS AND METHODS: MRI reports and physical examination from 210 healthy kidney donors (420 kidneys), on whom renal volumes were obtained using the voxel-count method, were retrospectively reviewed. These values along with ones obtained through a more traditional method (ellipsoid formula) were correlated with subject height, body weight, body mass index (BMI), and age. RESULTS: TRV correlated strongly with body weight (r=0.7) and to a lesser degree with height, age, or BMI (r=0.5, -0.2, 0.3, respectively). The left kidney volume was greater than the right, on average (p<0.001). The ellipsoid formula method over-estimated renal volume by 17% on average which was significant (p<0.001). CONCLUSIONS: Body weight was the physical characteristic which demonstrated the strongest correlation with renal volume in healthy subjects. Given this finding, a formula was derived for estimating the TRV for a given patient based on the his or her weight: TRV = 2.96 x weight (kg) + 113+/-64.

Multiple inflammatory and serum amyloid A positive telangiectatic hepatic adenomas with glycogenated nuclei arising in a background of nonalcoholic steatohepatitis.

The authors describe multiple telangiectatic or inflammatory adenomas in a 53-year-old woman with steatohepatitis who presented with acute right upper quadrant abdominal pain. Magnetic resonance imaging revealed 6 lesions consistent with multiple hepatic adenomas, 2 of which showed hemorrhage. She underwent right lobectomy and nonanatomical segment 2 liver resections and seven nodules ranging in size from 1.0 to 5.0 cm were identified. All nodules contained portal-like structures and ductular reaction, features seen in focal nodular hyperplasia, as well as significant inflammation, telangiectatic sinusoids and immunoreactivity for serum amyloid A, placing them according to a recently described classification systems as telangiectatic or inflammatory adenomas. The diffuse positivity of the serum amyloid A staining results in this case suggests an important diagnostic role of this stain in smaller tissue samples, such as in core biopsy specimens.

Phase II trial evaluating the clinical and biologic effects of bevacizumab in unresectable hepatocellular carcinoma.

PURPOSE: To determine the clinical and biologic effects of bevacizumab, an anti-vascular endothelial growth factor (VEGF) monoclonal antibody, in unresectable hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Adults with organ-confined HCC, Eastern Cooperative Oncology Group performance status of 0 to 2, and compensated liver disease were eligible. Patients received bevacizumab 5 mg/kg (n = 12) or 10 mg/kg (n = 34) every 2 weeks until disease progression or treatment-limiting toxicity. The primary objective was to determine whether bevacizumab improved the 6-month progression-free survival (PFS) rate from 40% to 60%. Secondary end points included determining the effects of bevacizumab on arterial enhancement and on plasma cytokine levels and the capacity of patients' plasma to support angiogenesis via an in vitro assay. RESULTS: The study included 46 patients, of whom six had objective responses (13%; 95% CI, 3% to 23%), and 65% were progression free at 6 months. Median PFS time was 6.9 months (95% CI, 6.5 to 9.1 months); overall survival rate was 53% at 1 year, 28% at 2 years, and 23% at 3 years. Grade 3 to 4 adverse events included hypertension (15%) and thrombosis (6%, including 4% with arterial thrombosis). Grade 3 or higher hemorrhage occurred in 11% of patients, including one fatal variceal bleed. Bevacizumab was associated with significant reductions in tumor enhancement by dynamic contrast-enhanced magnetic resonance imaging and reductions in circulating VEGF-A and stromal-derived factor-1 levels. Functional angiogenic activity was associated with VEGF-A levels in patient plasma. CONCLUSION: We observed significant clinical and biologic activity for bevacizumab in nonmetastatic HCC and achieved the primary study end point. Serious bleeding complications occurred in 11% of patients. Further evaluation is warranted in carefully selected patients.

Time-resolved MR angiography for the classification of endoleaks after endovascular aneurysm repair.

PURPOSE: To evaluate the utility of time-resolved MR angiography (TR-MRA), compared with digital subtraction angiography (DSA), in the classification of endoleaks in patients who have undergone endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: Thirty-one patients who had undergone EVAR to repair an abdominal aortic aneurysm were evaluated with both TR-MRA and DSA to determine endoleak etiology. The patient population consisted of 26 men and 5 women with a mean age of 78.5 years (range, 55-93 years). The mean time interval between TR-MRA and DSA was 1.5 weeks (range, 1-8 weeks). Endoleaks were classified as type II when enhancement of the external iliac vessels was observed before the appearance of the endoleak; otherwise the endoleak was classified as type I or III. The results of TR-MRA classification were compared with the reference gold standard, DSA. RESULTS: Agreement between TR-MRA and DSA regarding endoleak classification occurred in 30 of 31 cases (97%). Discordant classification occurred in a case in which a Type II endoleak was misclassified as a Type III due to failure to visualize a lumbar vessel. CONCLUSION: TR-MRA is highly effective in classifying endoleaks following EVAR when compared with DSA.

Resolution of hepatopulmonary syndrome after auxiliary partial orthotopic liver transplantation in Abernethy malformation. A case report.

Congenital absence of portal vein and extrahepatic portocaval shunt, also referred to as an Abernethy type 1, is a rare malformation of the mesenteric vasculature. A 9-year-old girl presented with dyspnea on exertion and orthodeoxia. A diagnosis of an Abernethy malformation type 1b and hepatopulmonary syndrome (HPS) was made, and she underwent auxiliary partial orthotopic liver transplantation (APOLT). Symptoms and signs of HPS resolved 2 months after the operation. HPS in Abernethy syndrome is a manifestation of normal portal blood flow bypassing the liver and can be ameliorated by redirecting blood flow to a segment of liver with normal portal anatomy. APOLT is a feasible and successful surgical procedure for patients with Abernethy malformation and HPS.