CT-based pleural effusion volume estimation formula demonstrates low accuracy and reproducibility for traumatic hemothorax.

PURPOSE: We aimed to evaluate the accuracy and reproducibility of the CT-based volume estimation formula V = d2 * h, where d and h represent the maximum depth and height of the effusion, for acute traumatic hemothorax. MATERIALS & METHODS: Prospectively identified patients with CT showing acute traumatic hemothorax were considered. Volumes were retrospectively estimated using d2 * h, then manually measured on axial images. Subgroup analysis was performed on borderline-sized hemothorax (200-400 mL). Measurements were repeated by three non-radiologists. Bland-Altman analysis was used to assess agreement between the two methods and agreement between raters for each method. RESULTS: A total of 46 patients (median age 34; 36 men) with hemothorax volume 23-1622 mL (median 191 mL, IQR 99-324 mL) were evaluated. Limits of agreement between estimates and measured volumes were -718 - +842 mL (± 202 mL). Borderline-sized hemothorax (n = 13) limits of agreement were -300 - +121 mL (± 114 mL). Of all hemothorax, 85 % (n = 39/46) were correctly stratified as over or under 300 mL, and of borderline-sized hemothorax, 54 % (n = 7/13). Inter-rater limits of agreement were -251 - +350, -694 - +1019, and -696 - +957 for the estimation formula, respectively, and -124 - +190, -97 - +111, and -96 - +46 for the measured volume. DISCUSSION: An estimation formula varies with actual hemothorax volume by hundreds of mL. There is low accuracy in stratifying hemothorax volumes close to 300 mL. Variability between raters was substantially higher with the estimation formula than with manual measurements.

Local aortic aneurysm wall expansion measured with automated image analysis.

BACKGROUND: Assessment of regional aortic wall deformation (RAWD) might better predict for abdominal aortic aneurysm (AAA) rupture than the maximal aortic diameter or growth rate. Using sequential computed tomography angiograms (CTAs), we developed a streamlined, semiautomated method of computing RAWD using deformable image registration (dirRAWD). METHODS: Paired sequential CTAs performed 1 to 2 years apart of 15 patients with AAAs of various shapes and sizes were selected. Using each patient's initial CTA, the luminal and aortic wall surfaces were segmented both manually and semiautomatically. Next, the same patient's follow-up CTA was aligned with the first using automated rigid image registration. Deformable image registration was then used to calculate the local aneurysm wall expansion between the sequential scans (dirRAWD). To measure technique accuracy, the deformable registration results were compared with the local displacement of anatomic landmarks (fiducial markers), such as the origin of the inferior mesenteric artery and/or aortic wall calcifications. Additionally, for each patient, the maximal RAWD was manually measured for each aneurysm and was compared with the dirRAWD at the same location. RESULTS: The technique was successful in all patients. The mean landmark displacement error was 0.59 ± 0.93 mm with no difference between true landmark displacement and deformable registration landmark displacement by Wilcoxon rank sum test (P = .39). The absolute difference between the manually measured maximal RAWD and dirRAWD was 0.27 ± 0.23 mm, with a relative difference of 7.9% and no difference using the Wilcoxon rank sum test (P = .69). No differences were found in the maximal dirRAWD when derived using a purely manual AAA segmentation compared with using semiautomated AAA segmentation (P = .55). CONCLUSIONS: We found accurate and automated RAWD measurements were feasible with clinically insignificant errors. Using semiautomated AAA segmentations for deformable image registration methods did not alter maximal dirRAWD accuracy compared with using manual AAA segmentations. Future work will compare dirRAWD with finite element analysis-derived regional wall stress and determine whether dirRAWD might serve as an independent predictor of rupture risk.

A large series of true pancreaticoduodenal artery aneurysms.

INTRODUCTION: True pancreaticoduodenal artery aneurysms (PDAAs) are rare, and prior reports often fail to distinguish true aneurysms from pseudoaneuryms. We sought to characterize all patients who presented to our health system from 2004 to 2019 with true PDAAs, with a focus on risk factors, interventions, and patient outcomes. METHODS: Patients were identified by querying a single health system picture archiving and communication system database for radiographic reports noting a PDAA. A retrospective chart review was performed on all identified patients. Patients with pseudoaneurysm, identified as those with a history of pancreatitis, abdominal malignancy, hepatopancreaticobiliary surgery, or abdominal trauma, were excluded. Continuous variables were compared using t-tests, and categorical variables were compared using Fisher's exact tests. RESULTS: A total of 59 true PDAAs were identified. Forty aneurysms (68%) were intact (iPDAAs) and 19 (32%) were ruptured (rPDAAs) at presentation. The mean size of rPDAAs was 16.4 mm (median size, 14.0 mm; range, 10-42 mm), and the mean size of iPDAAs was 19.4 mm (median size, 17.5 mm; range, 8-88 mm); this difference was not statistically significant (P = .95). Significant celiac disease (occlusion or >70% stenosis) was noted in 39 aneurysms (66%). Those with rupture were less likely to have significant celiac disease (42% vs 78%; P = .017) and less likely to have aneurysmal wall calcifications (6% vs 53%; P = .002). Thirty-seven patients underwent intervention (63%), with eight (22%) undergoing concomitant hepatic revascularization (two stents and six bypasses) due to the presence of celiac disease. Eighteen patients with occluded celiac arteries underwent aneurysm intervention; of those, 11 were performed without hepatic revascularization (61.1%). Those with rPDAAs experienced an aneurysm-related mortality of 10.5%, whereas those with iPDAAs experienced a rate of 5.6%. One patient with celiac occlusion and PDA rupture who did not undergo hepatic artery bypass expired postoperatively from hepatic ischemia. rPDAAs showed a trend toward the increased need for aneurysm-related endovascular or open reintervention, but this was not statistically significant (47% vs 28%; P = .13). CONCLUSIONS: These findings support previous reports that the rupture risk of PDAAs is independent of size, their development is often associated with significant celiac stenosis or occlusion, and rupture risk appears decreased in patients with concomitant celiac disease or aneurysm wall calcifications. Endovascular intervention is the preferred initial treatment for both iPDAAs and rPDAAs, but reintervention rates are high in both groups. The role for hepatic revascularization remains uncertain, but it does not appear to be mandatory in all patients with complete celiac occlusion who undergo PDAA interventions.

The Hyperattenuating Crescent Sign Is Not Necessarily a Sign of Impending Aortic Aneurysm Rupture.

BACKGROUND: The "crescent sign" is a hyperattenuating crescent-shaped region on CT within the mural thrombus or wall of an aortic aneurysm. Although it has previously been associated with aneurysm instability or impending rupture, the literature is largely based on retrospective analyses of urgently repaired aneurysms. We strove to more rigorously assess the association between an isolated "crescent sign" and risk of impending aortic rupture. METHODS: Patients were identified by querying a single health system PACS database for radiology reports noting a crescent sign. Adult patients with a CT demonstrating a descending thoracic, thoracoabdominal, or abdominal aortic aneurysm and "crescent sign" between 2004 and 2019 were included, with exclusion of those showing definitive signs of aortic rupture on imaging. RESULTS: A total of 82 patients were identified. Aneurysm size was 7.1 ± 2.0 cm. Thirty patients had emergent or urgent repairs during their index admission (37%), 19 had elective repairs at a later date (23%), and 33 patients had no intervention due to either patient choice or prohibitive medical comorbidities (40%). Patients without intervention had a median follow up of 275 days before death or loss to follow up. In patients undergoing elective intervention, 6,968 patient-days elapsed between presentation and repair, with zero episodes of acute rupture (median 105 days). Patients undergoing elective repair had smaller aneurysms compared to those who underwent emergent/urgent repair (6.2 ± 1.3 vs. 7.7 ± 2.1 cm, P = 0.008). No surgical candidate with an aneurysm smaller than 8 cm ruptured. There were 31 patients with previous axial imaging within 2 years prior to presentation with a "crescent sign," with mean aneurysm growth rate of 0.85 ± 0.62 cm per 6 months [median 0.65, range 0-2.6]. Those with aneurysms sized below 5.5 cm displayed decreased aneurysm growth compared to patients with aneurysm's sized 5.5-6.5 cm or patients with aneurysms greater than 6.5 cm (0.12 vs. 0.64 vs. 1.16 cm per 6 months, P= 0.002). CONCLUSIONS: The finding of an isolated radiographic "crescent sign" without other signs of definitive aortic rupture (i.e., hemothorax, aortic wall disruption, retroperitoneal bleeding) is not necessarily an indicator of impending aortic rupture, but may be found in the setting of rapid aneurysm growth. Many factors, including other associated radiographic findings, aneurysm size and growth rate, and patient symptomatology, should guide aneurysm management in these patients. We found that patients with minimal symptoms, aneurysm sizes below 6.5 cm, and no further imaging findings of aneurysm instability, such as periaortic fat stranding, can be successfully managed with elective intervention after optimization of comorbid factors with no evidence of adverse outcomes.

Occult Hepatocellular Carcinoma Associated With Transjugular Intrahepatic Portosystemic Shunts in Liver Transplant Recipients.

Transplant eligibility for hepatocellular carcinoma (HCC) is determined by the imaging identification of tumor burden within the Milan criteria. Transjugular intrahepatic portosystemic shunt(s) (TIPS) reduce portal hypertension but may impact HCC visualization. It was hypothesized that the presence of pretransplant TIPS would correlate with occult HCC and reduced survival. A single-center, retrospective, case control study was performed among liver transplant recipients with HCC (2000-2017). The primary endpoint was occult disease on explant pathology. Backward stepwise logistic regression was performed. The secondary endpoints disease-free survival (DFS) and overall survival (OS) were evaluated with Kaplan-Meier curves and Cox regression analysis. Of 640 patients, 40 had TIPS and more frequently exhibited occult disease (80.0% versus 43.1%; P < 0.001; odds ratio [OR], 4.16; P < 0.001). Portal vein thrombosis (PVT) similarly correlated with occult disease (OR, 1.97; P = 0.02). Explant tumor burden was equivalent between TIPS subgroups; accordingly, TIPS status was not independently associated with reduced DFS or OS. However, exceeding the Milan criteria was associated with reduced DFS (hazard ratio, 3.21; P = 0.001), and TIPS status in patients with a single suspected lesion (n = 316) independently correlated with explant tumor burdens beyond these criteria (OR, 13.47; P = 0.001). TIPS on pretransplant imaging are associated with occult HCC on explant pathology. Comparable occult disease findings in patients with PVT suggest that the mechanism may involve altered hepatic perfusion, obscuring imaging diagnosis. TIPS are not independently associated with reduced DFS or OS but are associated with exceeding the Milan criteria for patients with a single suspected lesion. The presence of TIPS may necessitate a higher index of suspicion for occult HCC.

Multicenter Study of Staging and Therapeutic Predictors of Hepatocellular Carcinoma Recurrence Following Transplantation.

Orthotopic liver transplantation (OLT) and resection are effective treatments for hepatocellular carcinoma (HCC). However, optimizing OLT and limiting HCC recurrence remains a vexing problem. New HCC Model for End-Stage Liver Disease and allocation algorithms provide greater observation of HCC patients, many while receiving local-regional treatments. Potential benefits of local-regional treatment for limiting HCC recurrence after OLT remain incompletely understood. Therefore, we aimed to define HCC-specific prognostic factors affecting recurrence in a contemporary, multicenter cohort of HCC patients undergoing OLT and specifically whether local-regional therapies limited recurrence. We identified 441 patients undergoing OLT for HCC at 3 major transplant centers from 2008 to 2013. Cox regression was used to analyze covariate-adjusted recurrence and mortality rates after OLT. "Bridging" or "downstaging" therapy was used in 238 (54%) patients with transarterial chemoembolization (TACE) being used in 170 (71%) of treated patients. The survival rate after OLT was 88% and 78% at 1 and 3 years, respectively, with HCC recurrence (28% of deaths) significantly increasing the mortality rate (hazard ratio [HR], 19.87; P < 0.001). Tumor size, not tumor number, either at presentation or on explant independently predicted HCC recurrence (HR, 1.36 and 1.73, respectively; P < 0.05) with a threshold effect noted at 4.0-cm size. Local-regional therapy (TACE) reduced HCC recurrence by 64% when adjusting for presenting tumor size (HR, 0.36; P < 0.05). Explant tumor size and microvascular invasion predicted mortality (HR, 1.19 and 1.51, respectively; P < 0.05) and pathologic response to therapy (TACE or radiofrequency ablation) significantly decreased explant tumor size (0.56-1.62 cm diameter reduction; P < 0.05). In conclusion, HCC tumor size at presentation or explant is the most important predictor for HCC recurrence after OLT. Local-regional therapy to achieve a pathologic response (decreasing tumor size) can limit HCC recurrences after OLT. Liver Transplantation 00 000-000 2018 AASLD.

Incidence of Occult Intrahepatic Metastasis in Hepatocellular Carcinoma Treated With Transplantation Corresponds to Early Recurrence Rates After Partial Hepatectomy.

OBJECTIVE: This study aimed to compare the incidence of radiologically unrecognized (occult) hepatocellular carcinoma (HCC) lesions in explant hepatectomy specimens from orthotopic liver transplants (OLTs) performed for HCC with rates of HCC intrahepatic recurrence after resection. SUMMARY OF BACKGROUND DATA: Resection of HCC is associated with high rates of intrahepatic HCC recurrence. However, it is unclear whether these recurrences represent incomplete resection of unrecognized metastatic lesions from the primary tumor or subsequent de novo tumor formation due to inherent biological proclivity for HCC formation. METHODS: We collected patient, tumor, and pathology data on HCC patients treated surgically from 3696 OLTs in the Organ Procurement and Transplantation (OPTN) national database, 299 OLTs at a single transplant center, and 232 partial hepatectomies from a hepatobiliary cancer center. RESULTS: In the OPTN and high-volume transplant center cohorts, 37% and 42% of patients had occult HCC lesions on explant pathology, respectively. Among cancer center patients, the 2-year recurrence rate was 46%, and 74% of patients who recurred presented with liver only recurrence. CONCLUSION: Although the transplant and resection populations differ, occult multifocality is common in transplant explants and similar to the 46% early recurrence rate following partial hepatectomy. These data suggest that noncurative resection often results from occult intrahepatic multifocality present at the time of resection rather than a malignant predisposition of the remnant liver with de novo tumorigenesis.

Effect of kidney donor hepatitis C virus serostatus on renal transplant recipient and allograft outcomes.

BACKGROUND: Hepatitis C virus (HCV) infection is common in dialysis patients and renal transplant recipients and has been associated with diminished patient and allograft survival. HCV-positive (HCV+) kidneys have been used in HCV-positive (HCV+) recipients as a means of facilitating transplantation and expanding the organ donor pool; however, the effect of donor HCV serostatus in the modern era is unknown. METHODS: Using national transplant registry data, we created a propensity score-matched cohort of HCV+ recipients who received HCV-positive donor kidneys compared to those transplanted with HCV-negative kidneys. RESULTS: Transplantation with an HCV+ kidney was associated with an increased risk of death {hazard ratio [HR] 1.43 [95% confidence interval (CI) 1.18-1.76]; P < 0.001} and allograft loss [HR 1.39 (95% CI 1.16-1.67); P < 0.001] compared with their propensity score-matched counterparts. However, HCV+ kidneys were not associated with an increased risk of acute rejection [odds ratio 1.16 (95% CI 0.84-1.61); P = 0.35]. CONCLUSIONS: While use of HCV+ donor kidneys can shorten the wait for renal transplantation and maximize organ utility for all candidates on the waiting list, potential recipients should be counseled about the increased risks associated with HCV+ kidney.

Survival Benefit of Transplantation with a Deceased Diabetic Donor Kidney Compared with Remaining on the Waitlist.

BACKGROUND AND OBJECTIVES: Use of diabetic donor kidneys has been a necessary response to the donor organ shortage. Recipients of diabetic donor kidneys have higher mortality risk compared with recipients of nondiabetic donor kidneys. However, the survival benefit of transplantation with diabetic donor kidneys over remaining on the waitlist has not been previously evaluated. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed an observational cohort study of 437,619 kidney transplant candidates from the Organ Procurement and Transplantation Network database, including 8101 recipients of diabetic donor kidneys and 126,560 recipients of nondiabetic donor kidneys. We used time-varying Cox proportional hazards modeling to assess the mortality risk of accepting a diabetic donor kidney compared with remaining on the waitlist or receiving a nondiabetic donor kidney. RESULTS: Among transplant recipients, median follow-up was 8.9 years and mortality rate was 35 deaths per 1000 person-years. Recipients of diabetic donor kidneys had 9% lower mortality compared with remaining on the waitlist or transplantation with a nondiabetic donor kidney (adjusted hazard ratio, 0.91; 95% confidence interval, 0.84 to 0.98). Although recipients of nondiabetic donor kidneys with a Kidney Donor Profile Index score >85% had lower mortality risk (adjusted hazard ratio, 0.86; 95% confidence interval, 0.81 to 0.91), recipients of diabetic donor kidneys with an index score >85% did not show any difference (adjusted hazard ratio, 1.09; 95% confidence interval, 0.97 to 1.22). Patients aged <40 years attained no survival benefit from transplantation with diabetic donor kidneys; diabetic patients at centers with long waitlist times attained the greatest survival benefit. CONCLUSIONS: Diabetic donor kidneys appear associated with higher mortality risk compared with nondiabetic donor kidneys, but offer greater survival benefit compared with remaining on the waitlist for many candidates. Patients with high risk of mortality on the waitlist at centers with long wait times appear to benefit most from transplantation with diabetic donor kidneys.

Belatacept Compared With Tacrolimus for Kidney Transplantation: A Propensity Score Matched Cohort Study.

BACKGROUND: Although tacrolimus is the basis of most maintenance immunosuppression regimens for kidney transplantation, concerns about toxicity have made alternative agents, such as belatacept, attractive to clinicians. However, limited data exist to directly compare outcomes with belatacept-based regimens to tacrolimus. METHODS: We performed a propensity score matched cohort study of adult kidney transplant recipients transplanted between May 1, 2001, and December 31, 2015, using national transplant registry data to compare patient and allograft survival in patients discharged from their index hospitalization on belatacept-based versus tacrolimus-based regimens. RESULTS: In the primary analysis, we found that belatacept was not associated with a statistically significant difference in risk of patient death (hazard ratio, 0.84; 95% confidence interval [CI], 0.61-1.15, P = 0.28) or allograft loss (hazard ratio, 0.83; 95% CI, 0.62-1.11; P = 0.20) despite an increased risk of acute rejection in the first year posttransplant (odds ratio, 3.12; 95% CI, 2.13-4.57; P < 0.001). These findings were confirmed in additional sensitivity analyses that accounted for use of belatacept in combination with tacrolimus, transplant center effects, and differing approaches to matching. CONCLUSIONS: Belatacept appears to have similar longitudinal risk of mortality and allograft failure compared with tacrolimus-based regimens. These data are encouraging but require confirmation in prospective randomized controlled trials.

Superior outcomes in HIV-positive kidney transplant patients compared with HCV-infected or HIV/HCV-coinfected recipients.

The prerequisite for an 'undetectable' HIV viral load has restricted access to transplantation for HIV-infected kidney recipients. However, HCV-infected recipients, owing to the historic limitations of HCV therapy in patients with renal disease, are commonly viremic at transplant and have universal access. To compare the effect of HIV, HCV, and HIV/HCV coinfection on kidney transplant patient and allograft outcomes, we performed a retrospective study of kidney recipients transplanted from January 1996 through December 2013. In multivariable analysis, patient (hazard ratio 0.90, 95% confidence interval 0.66-1.24) and allograft survival (0.60, 40-0.88) in 492 HIV patients did not differ significantly from the 117,791 patient-uninfected reference group. This was superior to outcomes in both the 5605 patient HCV group for death (1.44, 1.33-1.56) and graft loss (1.43, 1.31-1.56), as well as the 147 patient HIV/HCV coinfected group for death (2.26, 1.45-3.52) and graft loss (2.59, 1.60-4.19). HIV infection did not adversely affect recipient or allograft survival and was associated with superior outcomes compared with both HCV infection and HIV/HCV coinfection in this population. Thus, pretransplant viral eradication and/or immediate posttransplant eradication should be studied as potential strategies to improve posttransplant outcomes in HCV-infected kidney recipients.