Our evolution in the treatment of hepatic artery and portal vein thrombosis in pediatric liver transplantation: Success with catheter-directed therapies

BACKGROUND

In pediatric liver transplant recipients, hepatic artery thrombosis and portal vein thrombosis are major causes of acute graft failure and mortality within 30 days of transplantation. There is, however, a strong possibility of graft salvage if flow can be re-established to reduce ischemic injury. The current standard treatment is surgical revascularization, and if unsuccessful, retransplantation. Due to our success in treating these complications with catheter-directed therapies, we sought to summarize and publish the outcomes of all patients who experienced hepatic artery thrombosis or portal vein thrombosis within 30 days of liver transplantation.

METHODS

We conducted a retrospective cohort analysis of 27 pediatric liver transplant recipients who experienced hepatic artery thrombosis (n = 13), portal vein thrombosis (n = 9), or both (n = 5) between September 2012 and March 2021. We collected and tabulated data on the patients and therapies performed to treat them, including success rates, primary and secondary patency, and clinical outcomes.

RESULTS

Among these patients, 6 were managed with anticoagulation and relisting for transplant and 21 had a primary revascularization attempt. Surgical recanalization was attempted in 7 patients of which 3 had successful recanalization (43%) and catheter-directed recanalization was attempted in 14 patients with 100% success in re-establishing blood flow to the graft. Additionally, patency was increased, and mortality was decreased in patients treated with catheter-directed recanalization compared to surgical revascularization or anticoagulation alone.

CONCLUSION

This data illustrates the need to further investigate catheter-directed thrombolysis as a potential first-line treatment for postoperative HAT and PVT in pediatric liver transplant recipients.

Determinants of Chest X-Ray Sensitivity for COVID- 19: A Multi-Institutional Study in the United States

Purpose

To evaluate the sensitivity, specificity, and severity of chest x-rays (CXR) and chest CTs over time in confirmed COVID-19+ and COVID-19- patients and to evaluate determinants of false negatives.

Methods

In a retrospective multi-institutional study, 254 RT-PCR verified COVID-19+ patients with at least one CXR or chest CT were compared with 254 age- and gender-matched COVID-19- controls. CXR severity, sensitivity, and specificity were determined with respect to time after onset of symptoms; sensitivity and specificity for chest CTs without time stratification. Performance of serial CXRs against CTs was determined by comparing area under the receiver operating characteristic curves (AUC). A multivariable logistic regression analysis was performed to assess factors related to false negative CXR.

Results

COVID-19+ CXR severity and sensitivity increased with time (from sensitivity of 55% at ≤2 days to 79% at >11 days; p<0.001 for trends of both severity and sensitivity) whereas CXR specificity decreased over time (from 83% to 70%, p=0.02). Serial CXR demonstrated increase in AUC (first CXR AUC=0.79, second CXR=0.87, p=0.02), and second CXR approached the accuracy of CT (AUC=0.92, p=0.11). COVID-19 sensitivity of first CXR, second CXR, and CT was 73%, 83%, and 88%, whereas specificity was 80%, 73%, and 77%, respectively. Normal and mild severity CXR findings were the largest factor behind false-negative CXRs (40% normal and 87% combined normal/mild). Young age and African-American ethnicity increased false negative rates.

Conclusion

CXR sensitivity in COVID-19 detection increases with time, and serial CXRs of COVID-19+ patients has accuracy approaching that of chest CT.

Percutaneous Lung Biopsy in Immunocompromised Pediatric Patients

PURPOSE

To determine the diagnostic yield and safety of image-guided lung biopsies in immunocompromised pediatric patients.

MATERIALS AND METHODS

This was a retrospective pediatric cohort study conducted from June 2000 to April 2017. Subjects were 0-17 years of age (median, 10 years of age). There were 46 males (48%). A total of 73 consecutive image-guided lung biopsies were performed in 68 patients (weight range, 4.9-97.3 kg [median, 25.3 kg]). The indication for biopsy was to isolate an organism to tailor medical therapy. All patients were immunocompromised with an underlying history of bone marrow transplantation (n = 50), primary immunodeficiency (n = 14), and solid organ transplantation (n = 4). Patient and technical factors were analyzed for rates of complication.

RESULTS

Overall diagnostic yield was 43 of 73 patients (60%). There were 14 minor (19%) and 8 major (11%) complications. Major complications included pneumothorax or hemoptysis requiring intervention (n = 6), and death (n = 2). The histological diagnosis was an infectious cause in 5 of 8 major complications (63%). There were statistically significant differences between the rates of complications with the imaging modality used (P = .02) and the use of fine needle aspiration (P = .02).

CONCLUSIONS

Image-guided percutaneous lung biopsy can be helpful in isolating an organism to tailor therapy. Biopsies performed in immunosuppressed patients result in an elevated complication risk of up to 30% and demonstrate lower diagnostic yield and increased mortality, which should warrant detailed discussion with the primary team and family.

Generation of patient-derived tumor xenografts from percutaneous tumor biopsies in children with bone sarcomas

One of the limitations of performing percutaneous biopsies in patients with bone sarcomas is the small amount of tumor that can be obtained for research purposes. Here, we describe our experience developing patient-derived tumor xenografts (PDXs) using percutaneous tumor biopsies in children with bone sarcomas. We generated 14 bone sarcoma PDXs from percutaneous tumor biopsies. We also developed eight bone sarcoma PDXs from surgical resection of primary bone tumors and pulmonary metastases. A multidisciplinary team approach was critical to establish an accurate diagnosis and to provide adequate tumor samples for PDX generation.

Recanalization of Chronic Portal Vein Occlusion in Pediatric Liver Transplant Patients

PURPOSE

To evaluate technical and clinical success and report long-term outcomes of portal vein (PV) recanalization in pediatric orthotopic liver transplant (OLT) patients with chronic PV occlusion.

MATERIALS AND METHODS

This is a retrospective review of 15 OLT patients (5 males) with chronic PV occlusion who underwent PV recanalization (33 procedures) between October 2011 and February 2018. Median age was 4.5 years (range, 1-16 years); median weight was 16.6 kg (range, 11.5-57.3 kg). Median time interval from OLT to first intervention was 3.25 years (range, 0.6-15.7 years). Clinical presentations included hypersplenism (n = 12), gastrointestinal bleeding (n = 9), and ascites (n = 3). One patient had incidental diagnosis of PV occlusion. Primary, primary-assisted, and secondary patency at 3, 6, 12, and 24 months were evaluated.

RESULTS

Technically successful PV recanalization and reduction of PV pressure gradient to ≤ 5 mm Hg was performed in 13/15 patients (87%). Ten of 15 (67%) patients had successful recanalization with the first attempt. Clinical success, defined as improvement in signs and symptoms of portal hypertension, was achieved in 12/13 (92%) patients. Five of 33 (15%) major complications (Society of Interventional Radiology class C), including perisplenic hematoma (n = 2), hemoperitoneum (n = 2), and hepatic artery pseudo aneurysm (n = 1), were managed with pain medication and blood product replacement. Median follow-up was 22 months (range, 1-77 months). Median primary patency was 5 months. Primary patency at 3, 6, 12, and 24 months was 53.8%, 46.2%, 38.5%, and 30.8%, respectively. Primary-assisted patency was 84.6%, 76.9%, 53.8%, and 46.2%, respectively. Secondary patency was 92.3%, 84.6%, 53.8%, and 46.2%, respectively.

CONCLUSIONS

PV recanalization is a safe and effective minimally invasive option in the management of chronic PV occlusion after pediatric OLT.