scholarly journals Influence of interapplicator distance on multibipolar radiofrequency ablation during physiological and interrupted liver perfusion in an in vivo porcine model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
F. G. M. Poch ◽  
C. A. Neizert ◽  
B. Geyer ◽  
O. Gemeinhardt ◽  
L. Bruder ◽  
...  
Keyword(s):  
Blood Flow ◽  
Radiofrequency Ablation ◽  
Hepatic Blood Flow ◽  
Early Stage ◽  
Liver Perfusion ◽  
Strict Adherence ◽  
Ablation Area ◽  
The Impact ◽  
Pringle Manoeuvre

Abstract Radiofrequency ablation (RFA) is a curative treatment option for early stage hepatocellular carcinoma (HCC). Vascular inflow occlusion to the liver (Pringle manoeuvre) and multibipolar RFA (mbRFA) represent possibilities to generate large ablations. This study evaluated the impact of different interapplicator distances and a Pringle manoeuvre on ablation area and geometry of mbRFA. 24 mbRFA were planned in porcine livers in vivo. Test series with continuous blood flow had an interapplicator distance of 20 mm and 15 mm, respectively. For a Pringle manoeuvre, interapplicator distance was predefined at 20 mm. After liver dissection, ablation area and geometry were analysed macroscopically and histologically. Confluent and homogenous ablations could be achieved with a Pringle manoeuvre and an interapplicator distance of 15 mm with sustained hepatic blood flow. Ablation geometry was inhomogeneous with an applicator distance of 20 mm with physiological liver perfusion. A Pringle manoeuvre led to a fourfold increase in ablation area in comparison to sustained hepatic blood flow (p < 0.001). Interapplicator distance affects ablation geometry of mbRFA. Strict adherence to the planned applicator distance is advisable under continuous blood flow. The application of a Pringle manoeuvre should be considered when compliance with the interapplicator distance cannot be guaranteed.

Clinical Application of Radiofrequency Ablation for Malignant Liver Tumor during Interruption of Hepatic Blood Flow

2000 ◽  
Vol 18 ◽  
pp. 121-125
Author(s):  
Takashi Shibata ◽  
Takahiro Niinobu ◽  
Masashi Kitada ◽  
Takashi Shimano ◽  
Motohisa Takami ◽  
...  
Keyword(s):  
Blood Flow ◽  
Radiofrequency Ablation ◽  
Clinical Application ◽  
Hepatic Blood Flow ◽  
Liver Tumor ◽  
Malignant Liver Tumor ◽  
Malignant Liver

scholarly journals Perivascular vital cells in the ablation center after multibipolar radiofrequency ablation in an in vivo porcine model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
F. G. M. Poch ◽  
C. A. Neizert ◽  
B. Geyer ◽  
O. Gemeinhardt ◽  
S. M. Niehues ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Early Stage ◽  
Pringle Maneuver ◽  
Vessel Diameter ◽  
Inflow Occlusion ◽  
White Zone ◽  
Cell Vitality ◽  
Internally Cooled ◽  
Hepatic Vessels

AbstractMultibipolar radiofrequency ablation (RFA) is an advanced ablation technique for early stage hepatocellular carcinoma and liver metastases. Vessel cooling in multibipolar RFA has not been systematically investigated. The objective of this study was to evaluate the presence of perivascular vital cells within the ablation zone after multibipolar RFA. Multibipolar RFA were performed in domestic pigs in vivo. Three internally cooled bipolar RFA applicators were used simultaneously. Three experimental settings were planned: (1) inter-applicator-distance: 15 mm; (2) inter-applicator-distance: 20 mm; (3) inter-applicator-distance: 20 mm with hepatic inflow occlusion (Pringle maneuver). A vitality staining was used to analyze liver cell vitality around all vessels in the ablation center with a diameter > 0.5 mm histologically. 771 vessels were identified. No vital tissue was seen around 423 out of 429 vessels (98.6%) situated within the central white zone. Vital cells could be observed around major hepatic vessels situated adjacent to the ablation center. Vessel diameter (> 3.0 mm; p < 0.05) and low vessel-to-ablation-center distance (< 0.2 mm; p < 0.05) were identified as risk factors for incomplete ablation adjacent to hepatic vessels. The vast majority of vessels, which were localized in the clinically relevant white zone, showed no vital perivascular cells, regardless of vessel diameter and vessel type. However, there was a risk of incomplete ablation around major hepatic vessels situated directly within the ablation center. A Pringle maneuver could avoid incomplete ablations.

scholarly journals Feasibility of balloon-based endobiliary radiofrequency ablation under cholangioscopy guidance in a swine model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tadahisa Inoue ◽  
Hiromu Kutsumi ◽  
Mayu Ibusuki ◽  
Masashi Yoneda
Keyword(s):  
Radiofrequency Ablation ◽  
Adverse Events ◽  
Swine Model ◽  
Biliary Strictures ◽  
Tissue Samples ◽  
Ablation Area ◽  
Mucosal Changes ◽  
The Mean ◽  
Preliminary Study

AbstractAlthough endobiliary radiofrequency ablation (RFA) has demonstrated considerable potential for the treatment of biliary strictures, conventional catheter RFA has several limitations. This study aimed to evaluate the feasibility of a novel cholangioscopy (CS)-guided balloon-based RFA procedure in vivo using a swine model. CS-guided balloon-RFA was performed under endoscopic retrograde cholangiography guidance at target temperatures of 60 ℃ or 70 ℃, which were maintained for 60 s. We evaluated the technical feasibility, adverse events, and histological effects associated with the procedure. Twelve sites were ablated in seven miniature pigs. The CS-guided balloon-RFA procedure was technically successful in all cases without any hindrance. Mucosal changes could be detected during RFA, and the ablation area was identified on CS. Necropsy was performed in four pigs on the same day as the procedure: the tissue samples showed coagulative necrosis, and the entire internal circumference of the bile duct was uniformly ablated. The mean lengths of the ablation area in the samples ablated at 60 °C and 70 °C were 20.64 and 22.18 mm, respectively, while the mean depths were 3.46 and 5.07 mm, respectively. The other three pigs were reared and euthanized and autopsied 35 days after the procedure. The site to be ablated had replaced the granulation tissue and fibrotic changes. No adverse events were observed in any case. CS-guided balloon-RFA appears to be a promising option for treating biliary strictures. This preliminary study could pave the way for the evaluation of this procedure in future human clinical trials.

scholarly journals Temperature Effects on Radiocolloid Uptake by the Isolated Rat Liver

1957 ◽  
Vol 189 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Ralph W. Brauer ◽  
R. J. Holloway ◽  
George F. Leong
Keyword(s):  
Blood Flow ◽  
Rat Liver ◽  
Hepatic Blood Flow ◽  
Reaction Rate ◽  
Extraction Efficiency ◽  
Liver Blood Flow ◽  
Isolated Rat Liver ◽  
Isolated Rat ◽  
Unambiguous Interpretation

Effect of temperatures between 20° and 38°C on the relation between blood flow and CrPO4 colloid uptake by the isolated rat liver has been studied. The Q10 for the over-all reaction rate is substantially constant and equal to 1.92 over this range. Theoretical limitations prevent the unambiguous interpretation of this value as a measure of the Q10 of the basic uptake reaction. Hemodynamic data indicate that cooling affects liver blood flow and liver blood distribution primarily, but not exclusively, through increasing blood viscosity. Evidence pointing to possible vasorelaxation under these conditions is mentioned. The application of these results to measurements of liver blood flow in hypothermia in vivo is discussed and the required diagram relating hepatic blood flow with the product of CrPO4 extraction efficiency and hepatic blood flow for the rat is presented.

Measurement of hepatic blood flow after severe hemorrhage: lack of restoration despite adequate resuscitation

1992 ◽  
Vol 262 (1) ◽  
pp. G92-G98 ◽  
Author(s):  
P. Wang ◽  
Z. F. Ba ◽  
J. Burkhardt ◽  
I. H. Chaudry
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Hemorrhagic Shock ◽  
Hepatic Blood Flow ◽  
Microvascular Blood Flow ◽  
Midline Laparotomy ◽  
Doppler Flowmetry ◽  
Severe Hemorrhage ◽  
Icg Clearance

Although Ringer lactate (RL) is routinely used for resuscitation, it is not known whether the volume of RL that restores cardiac output after severe hemorrhagic shock also restores the depressed effective hepatic blood flow (EHBF). To study this, a 5-cm midline laparotomy was performed in rats (i.e., trauma induced), and the animals were then bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of maximum bleedout volume was returned in the form of RL. Animals were then resuscitated with four or five times the volume of maximum bleedout with RL. EHBF was determined during hemorrhage and at various intervals thereafter by an in vivo indocyanine green (ICG) clearance technique and corrected by the appropriate hepatic extraction ratio for ICG. Cardiac output was determined by ICG dilution, and hepatic microvascular blood flow (HMBF) was measured with laser Doppler flowmetry. In addition, hepatic blood flow was assessed by using radioactive microspheres. Results indicate that resuscitation markedly improved but did not restore the depressed EHBF after trauma and hemorrhagic shock despite the fact that cardiac output was restored. Similar changes in EHBF, HMBF, and hepatic blood flow as determined by microspheres were observed, suggesting that the in vivo ICG clearance is a reliable method to assess effective hepatic perfusion. Thus the lack of restoration of EHBF may be responsible for the subsequent hepatocellular dysfunction after trauma and severe hemorrhage.

Lactate delivery (not oxygen) limits hepatic gluconeogenesis when blood flow is reduced

2006 ◽  
Vol 290 (1) ◽  
pp. E192-E198 ◽  
Author(s):  
Ken D. Sumida ◽  
Jerry H. Urdiales ◽  
Casey M. Donovan
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Oxygen Delivery ◽  
Liver Perfusion ◽  
Lactate Concentration ◽  
Oxygen Availability ◽  
Limiting Factor ◽  
Hepatic Gluconeogenesis ◽  
Experimental Protocols ◽  
The Impact

The purpose of this study was to determine, using the isolated liver perfusion technique, whether the limiting factor for hepatic gluconeogenesis (GNG) from lactate was precursor delivery or oxygen availability during reduced flow rates of 0.85 or 0.60 ml·min−1·g liver−1. After a 24-h fast, three different experimental protocols were employed. Protocol 1 examined the impact on GNG when reservoir lactate concentration was maintained but oxygen delivery was elevated via increases in hematocrit (Hct). Elevating the Hct from 22.5 ± 0.8% to 30.9 ± 0.4% at a blood flow of 0.89 ± 0.01 ml·min−1·g liver−1 increased the oxygen consumption (V̇o2) but did not augment GNG. Similarly, when the Hct was elevated from 22.5 ± 0.8% to 41.5 ± 0.7% at 0.59 ± 0.04 ml·min−1·g liver−1, V̇o2 was increased, but GNG was unaffected. Protocol 2 examined the impact on GNG when Hct was maintained but precursor delivery was elevated via increases in reservoir lactate concentration ([LA]). Specifically, elevating the [LA] from 2.31 ± 0.07 to 3.61 ± 0.33 mM at a flow rate of 0.82 ± 0.04 ml·min−1·g liver−1 significantly increased GNG. Similarly, elevating the [LA] from 2.31 ± 0.07 to 4.24 ± 0.37 mM at a flow rate of 0.58 ± 0.02 ml·min−1·g liver−1 increased GNG. Finally, we examined the impact of increasing both the oxygen and lactate delivery ( Protocol 3). Again, V̇o2 was elevated with increased oxygen delivery, but GNG was not augmented beyond that observed with elevations in lactate delivery alone, i.e., Protocol 2. The results indicate that, during decrements in blood flow, GNG is limited primarily by precursor delivery, not oxygen availability.

scholarly journals How does alteration of hepatic blood flow affect liver perfusion and radiofrequency-induced thermal lesion size in rabbit liver?

2001 ◽  
Vol 13 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Andrik J. Aschoff ◽  
Elmar M. Merkle ◽  
Virginia Wong ◽  
Qiang Zhang ◽  
Matthew M. Mendez ◽  
...  
Keyword(s):  
Blood Flow ◽  
Hepatic Blood Flow ◽  
Liver Perfusion ◽  
Lesion Size ◽  
Rabbit Liver ◽  
Thermal Lesion

scholarly journals Assessment of choriocapillary blood flow changes in response to half-dose PDT in chronic central serous chorioretinopathy using OCTA

2020 ◽  
Author(s):  
Juejun Liu ◽  
Changzheng Chen ◽  
Lu Li ◽  
Yishuang Xu ◽  
Zuohuizi Yi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Central Serous Chorioretinopathy ◽  
Early Stage ◽  
Early Response ◽  
Therapeutic Effects ◽  
Chronic Central Serous Chorioretinopathy ◽  
Half Dose ◽  
Flow Changes

Abstract Background: Optical coherence tomography angiography (OCTA) is a principally new imaging technique that provide quantitative method to analyze choriocapillaris (CC) flow changes, while assessment of CC in vivo could be valuable in understanding the pathological mechanism of chronic central serous chorioretinopathy (CCSC) and the therapeutic effects of photodynamic therapy (PDT). In this study, we sought to quantify blood flow changes in CC of CCSC patients receiving half-dose PDT using OCTA.Methods: A total of 28 affected eyes and 24 unaffected eyes of 26 CCSC patients receiving half-dose PDT, and 40 eyes of 20 healthy gender- and age-matched subjects were retrospectively enrolled. The proportion of total areas of flow signal voids (FSV, %) in CC level of OCTA was assessed in both eyes of the CCSC patients at baseline and repeated in multiple sections at 1-week, 1-month, 3-month and 6-month intervals after PDT. In addition, CC patterns in response to PDT at early stage and their subsequent morphologic changes were qualitatively documented using OCTA. Results: For affected eyes, significant decrease in FSV was found at 6-m follow-up when compared with that at 1-m follow-up (p=0.036). When compared to normal control eyes, FSV in affected eyes was significantly higher at 1-m, 3-m and 6-m follow-up (p<0.05 for all), while FSV in unaffected eyes was significantly higher at baseline, 1-w, 1-m and 3-m follow-up (p<0.05 for all). Three CC patterns of early response to PDT were identified, including signs of recovery with more even flow signals, transient appearance of worse ischemia and secondary neovascularization within CC level.Conclusion: Abnormal CC flow attenuation remains in completely resolved eyes of CCSC patients treated with half-dose PDT.

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