Hepatopulmonary shunting after surgical, interventional and systemic therapy in patients with liver malignancies scheduled for radioembolization

BACKGROUND

Hepatopulmonary shunts (HPS) lead to radiation exposure of the lungs in patients undergoing radioembolization (RE) of malignant liver tumors.

PURPOSE

To retrospectively analyze how HPS is affected by prior systemic or local therapy of the liver.

MATERIAL AND METHODS

The percentage HPS was calculated from SPECT/CT scans obtained after technetium-99 m macroaggregated albumin administration into hepatic arteries in 316 patients evaluated for RE.

RESULTS

Patients with partial liver resection (n = 80) did not differ in HPS from the remaining patient population (n = 236) (HPS (median [range]) = 10.2 [2.1-48.3]resection% vs. 8.9 [2.3-32.9]no resection%; P = 0.527). In patients undergoing sequential RE, HPS was significantly higher in the liver lobe treated second (n = 10; HPS = 6.4 [2.1-10.2]firstlobe/session% vs. 12.0 [2.0-24.6]second lobe/session%; P = 0.019). (Chemo-)embolization (n = 19; HPS = 11.0 [2.8-48.3]%) or transcutaneous ablation (n = 63; HPS = 8.8 [3.0-32.9]%) had no effect on HPS compared to patients without prior interventions (no (chemo-)embolization: n = 297; HPS = 9.3 [2.1-47.3]%; P = 0.489; no ablation: n = 253; HPS = 9.5 [2.1-48.3]%; P = 0.382). Pretreatment with sorafenib (HPS = 9.5 [2.3-35.9]yes% vs. 10.2 [2.8-42.0]no%; P = 0.777) orbevacizumab (HPS = 10.7 [2.1-30.6]yes% vs. 9.0 [3.9-23.3]no%; P = 0.870) had no effect on HPS.

CONCLUSION

Sequential RE results in an increase in the HPS in the contralateral liver lobe at the time of the second RE session. Other investigated therapy do not affect HPS.

Impaired hepatic Gd-EOB-DTPA enhancement after radioembolisation of liver malignancies

INTRODUCTION

To evaluate the uptake of the liver-specific magnetic resonance imaging (MRI) contrast agent gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) by functional liver parenchyma after radioembolisation (RE) of hepatic malignancies.

METHODS

Uptake of Gd-EOB-DTPA prior to RE versus 60+/-24d and 126+/-32d after RE was compared in a group of 33 patients with primary or secondary hepatic malignancies. In patients who underwent single-lobe treatment, left and right lobes were compared 59+/-24 days after RE. Gd-EOB-DTPA uptake was determined as follows: ratio of mean signal intensity in liver parenchyma to muscle in Gd-EOB-DTPA-enhanced T1-weighted MRI was subtracted from ratio of mean intensity in liver parenchyma to muscle in unenhanced T1-weighted MRI.

RESULTS

Gd-EOB-DTPA uptake in liver parenchyma was 0.845+/-0.29 before RE, 0.615+/-0.38 (P = 0.0022) at day 60+/-24, and 0.739+/-0.30 at day 126+/-32 after RE. In cases of single-lobe treatment, Gd-EOB-DTPA uptake was 0.581+/-0.256 for treated and 0.828+/-0.32 (P = 0.0164) for untreated hepatic lobes.

CONCLUSIONS

Uptake of Gd-EOB-DTPA by liver parenchyma is impaired after RE, indicating dysfunction of the local hepatic system. These findings suggest that Gd-EOB-DTPA-enhanced MRI has the potential to be used for monitoring liver damage after RE.

Surgical Wound Fluid From Elderly Patients Shows a Dramatically Reduced Potential to Stimulate In-vitro Recruitment and Differentiation of Endothelial Progenitor Cells: Role of VEGF-165 and TGF-β1

Purpose. Elderly patients are susceptible to wound healing problems due to impaired neovascularisation in tissue repair. We investigated influence of surgical wound fluid (WF) obtained from both young and aged patients after musculoskeletal surgery on in-vitro recruitment and differentiation of endothelial progenitor cells (EPCs). Further, VEGF and TGF-b1 in WF were measured and blockade experiments were performed to analyze the role of both cytokines in EPC recruitment.

METHODS

WF was obtained from young (28 ± 5 years, n = 14) and elderly (74 ± 8 years, n = 15) patients at 3, 8, and 24 hours after surgery. EPCs were isolated from healthy donors and incubated (72 hours) in medium substituted by WF. EPC number/differentiation was determined by fluorescence-microscopy and flow-cytometry after staining for DiLDL and lectin. CBF or ELISA was used to measure VEGF and TGF-b1 in WF. For blockade experiments, WF was mixed with antibodies against VEGF/TGF-b1 before incubation.

RESULTS

A significantly higher number and increased differentiation of EPC can be observed after incubation with WF from young compared to elderly individuals. VEGF and TGF-b1 were higher in young patients' WF, and blockade of both cytokines reduced EPC numbers significantly.

CONCLUSION

Impaired wound healing in the elderly could be a result of dampened recruitment of EPC to site of affliction, possibly due to low VEGF/TGF-b1 levels.  .

CD133+CD34+ stem cells are mobilized after musculoskeletal surgery and target endothelium activated by surgical wound fluid

PURPOSE

CD133+CD34+ hematopoietic stem cells (HSCs) have been shown to differentiate into cell types of nonhematopoietic lineage. It is unclear whether HSCs target and repair damaged musculoskeletal tissue. We aimed to analyze if HSCs are mobilized after musculoskeletal surgery to circulation, home to surgical wound fluid (SWF)-activated endothelium, and are chemoattracted by SWF under in vitro conditions.

METHODS

Circulating HSC levels were measured at t = 3, 8, 24, 48 h postoperatively using fluorescence-activated cell sorting (FACS) and compared with preoperative levels (t = 0) and normal volunteers. For adhesion experiments, HSCs were incubated on SWF-activated human umbilical vein endothelial cells (HUVECs) and HSC/HUVEC ratios determined by FACS. Adhesion receptor expression on HSC (L-selectin, lymphocyte function-associated antigen 1 (LFA-1), very late antigen-4) and SWF-activated HUVECs (P-selectin, E-selectin, V-cell adhesion molecules (CAM), I-CAM) was determined and HSC adhesion measured again after blocking upregulated receptors. Using a modified Boyden chamber, HSC chemotaxis was analyzed for an SWF and cytokine-neutralized SWF (vascular endothelial growth factor (VEGF), stromal-derived factor-1, interleukin-8) gradient.

RESULTS

Circulating HSCs were significantly increased 8 h after surgery. Increasing HSC adhesion to HUVECs was shown for SWF isolated at any postoperative time point, and chemoattraction was significantly induced in an SWF gradient with SWF isolated 8 and 24 h postoperatively. Receptor and cytokine blockade experiments with monoclonal antibodies revealed decreased HSC adhesion to SWF-activated endothelium and showed lower chemotaxis after blocking the LFA-1-I-CAM-1 receptor axis (adhesion) and neutralizing VEGF-165 (chemotaxis).

CONCLUSIONS

Our data demonstrate that HSCs are mobilized after trauma, target to wound-associated endothelium via the LFA-1-I-CAM-1 axis, and are chemoattracted by VEGF-165 under in vitro conditions.