Artificial Circulation of the Liver: Machine Perfusion as a Preservation Method in Liver Transplantation

Due to the sharp increase in liver transplant candidates and the subsequent shortage of suitable donor livers, an extension of the current donor criteria is necessary. Simple cold storage, the current standard in organ preservation has proven to be insufficient to preserve extended criteria donor livers. Therefore a renewed interest grew toward alternative methods for liver preservation, such as hypothermic machine perfusion and normothermic machine perfusion. These “new” preservation methods were primarily assessed in rat models, and only a few clinically relevant large animal models have been described so far. This review will elaborate on these alternative preservation methods. Anat Rec, 291:735–740, 2008. © 2008 Wiley‐Liss, Inc.     

Analyzing the human liver vascular architecture by combining vascular corrosion casting and micro‐CT scanning: a feasibility study

Although a full understanding of the hepatic circulation is one of the keys to successfully perform liver surgery and to elucidate liver pathology, relatively little is known about the functional organization of the liver vasculature. Therefore, we materialized and visualized the human hepatic vasculature at different scales, and performed a morphological analysis by combining vascular corrosion casting with novel micro‐computer tomography (CT) and image analysis techniques. A human liver vascular corrosion cast was obtained by simultaneous resin injection in the hepatic artery (HA) and portal vein (PV). A high resolution (110 μm) micro‐CT scan of the total cast allowed gathering detailed macrovascular data. Subsequently, a mesocirculation sample (starting at generation 5; 88 × 68 × 80 mm³) and a microcirculation sample (terminal vessels including sinusoids; 2.0 × 1.5 × 1.7 mm³) were dissected and imaged at a 71‐μm and 2.6‐μm resolution, respectively. Segmentations and 3D reconstructions allowed quantifying the macro‐ and mesoscale branching topology, and geometrical features of HA, PV and hepatic venous trees up to 13 generations (radii ranging from 13.2 mm to 80 μm; lengths from 74.4 mm to 0.74 mm), as well as microvascular characteristics (mean sinusoidal radius of 6.63 μm). Combining corrosion casting and micro‐CT imaging allows quantifying the branching topology and geometrical features of hepatic trees using a multiscale approach from the macro‐ down to the microcirculation. This may lead to novel insights into liver circulation, such as internal blood flow distributions and anatomical consequences of pathologies (e.g. cirrhosis).     

Chirurgie de la thyroid

Background: We evaluated the concordance between peri-areolar blue dye and peri-incisional radiotracer injections for axillary sentinel node mapping of patients with the history of previous breast lesion excisional biopsy. Methods: 80 patients with the history of previous excisional biopsy of the breast lesions were included. All patients received two injections of 99mTc-antimony sulfide colloid in both ends of incision line in an intradermal fashion. 2 mL patient blue V dye was injection to all patients in the peri-areolar area of the index quadrant after induction of anesthesia. All blue or hot nodes were harvested as sentinel lymph nodes.

Results: At least one sentinel node could be detected during surgery in 79 patients. In total 94 sentinel nodes were detected. All detected sentinel nodes were hot. In three patients sentinel nodes were detected by gamma probe but not blue dye. The tumor location in all of these patients was in the upper lateral quadrant and the incision line was extended into the axillary tail of the breast in all of them. 91 out of 94 sentinel nodes were stained blue, which amounts to 95.8% concordance between blue dye and radiotracer on a per node analysis.

Conclusions: Single peri-areolar injection in the index quadrant would suffice for sentinel node mapping of patients with history of excisional biopsy. Care should be taken in patients with large excisional biopsy in the extreme proximity to axilla.     

Clinical characteristics of impaired trunk control in children with spastic cerebral palsy

This study aimed to identify clinical characteristics of impaired trunk control in hundred children with spastic CP (mean age 11.4 ± 2.1 years, range 8–15 years). Assessment of trunk control was performed with the Trunk Control Measurement Scale (TCMS). Trunk control was clearly impaired, indicated by a median total TCMS score of 38.5 out of 58 (66%). Median subscale scores were 18 out of 20 (90%) for the subscale static sitting balance, 16 out of 28 (57%) for the subscale selective movement control and 6 out of 10 (60%) for the subscale dynamic reaching. Total TCMS and subscale scores differed significantly between topographies and severity of motor impairment according to the Gross Motor Function Classification System (GMFCS). Children with hemiplegia obtained the highest scores, followed by children with diplegia and children with quadriplegia obtained the lowest scores. TCMS scores significantly decreased with increasing GMFCS level. In conclusion, trunk control is impaired in children with CP to a various extent, depending on the topography and severity of the motor impairment. The findings of this study also provide specific clues for treatment interventions targeting trunk control to improve their functional abilities.     

Cardioprotective effects of the serine protease inhibitor aprotinin after regional ischemia and reperfusion on the beating heart

OBJECTIVE: Early coronary reperfusion of the ischemic myocardium is a desired therapeutic goal to preserve myocardium. However, reperfusion itself contributes to an additional myocardial injury (ie, reperfusion injury), which has been attributed to neutrophil infiltration with subsequent release of proteases and oxygen-derived radicals. We studied the effects of the serine protease inhibitor aprotinin (Trasylol) on myocardial ischemia and reperfusion in a rat model. METHODS: The effects of aprotinin (5000 and 20,000 U/kg) were examined in vivo in a rat model of regional myocardial ischemia (20 minutes) and long-term reperfusion (24 hours). Cardioprotecive effects were determined by means of measurement of creatine kinase and myeloperoxidase activity within the myocardium, as well as histochemical analysis. RESULTS: Aprotinin (20,000 U/kg) administrated 2 minutes before reperfusion significantly attenuated myocardial injury expressed as creatine kinase washout compared with that seen in vehicle-treated rats (65 +/- 25 vs 585 +/- 98 creatine kinase difference in units per 100 mg, P <.01). Administration of 5000 U/kg of the protease inhibitor resulted in partial inhibition of myocardial reperfusion injury. Moreover, cardiac myeloperoxidase activity in the ischemic myocardium, a marker of neutrophil accumulation, was significantly reduced after aprotinin treatment. Histologic analysis of the reperfused myocardium demonstrated reduced polymorphonuclear leukocyte infiltration and reduced tissue injury. Furthermore, aprotinin treatment resulted in decreased induction of cardiac myocyte apoptosis compared with that seen in vehicle-treated rats. CONCLUSIONS: Inhibition of serine proteases with aprotinin appears to be an effective means of preserving ischemic myocardium from reperfusion injury, even after 24 hours of reperfusion. Aprotinin might exert cardioprotection through inhibition of polymorphonuclear leukocyte-induced myocardial injury and inhibition of reperfusion-induced apoptosis of cardiac myocytes.     

Liver transplantation using livers from septuagenarian and octogenarian donors: an underused strategy to reduce mortality on the waiting list

Shortage of liver grafts is the only limiting factor for application of liver transplantation and causes an increasing mortality on the waiting list. Very old donors (>70 to 80 years old) are rarely referred to transplant centers because of the assumption that these livers will not work properly. Alternatively, transplant teams may be reluctant to use these very old livers due to the risk of poor posttransplant outcome. We reviewed our experience with seven liver transplantations using very old donor livers. We found that the results in terms of graft function and patient survival are adequate. Interestingly, the majority of these donors originated from a single referring donor unit (of more than 20 units who belong to our donor network) that systematically refers all brain-dead donors to the transplant center, independent of the age of the potential donor. This implies that many of these donors are left undetected in other units. In conclusion, very old donors should be referred to transplant centers since results of transplantation with these grafts are favorable.     

Magnetic resonance imaging characteristics of six radiofrequency electrodes in a phantom study

PURPOSE: To evaluate and compare visibility and artifacts in magnetic resonance (MR) compatible radiofrequency (RF) electrodes for MR-guided RF ablation. MATERIAL AND METHODS: Six different MR compatible electrodes for RF ablation including two internally cooled single needles, one internally cooled cluster needle, two expandable needles and one perfused needle were tested in a phantom study at 0.2 Tesla and at 1.5 Tesla field strength. Fluoroscopic, T1- and T2-weighted fast spin echo (FSE) and gradient echo (GE) sequences, which are usually used for MR-guided interventions, were evaluated. Qualitative and quantitative evaluations were performed. Length, width, noise, tip artifacts, global artifacts and global visualization of the RF electrodes that showed all sequences at different angles. RESULTS: Qualitative analysis showed that electrodes were well visualized at all angles and sequences and on both MR imagers. Quantitative analysis showed that artifact-induced widening of the shaft was increased in all electrodes by: a). use of fluoroscopic sequences, GE sequences, and fat saturation, b). increasing the angle between the needle and main magnetic field, and c). high field strength (1.5 T). Expandable needles produced fewer tip artifacts but broader signal voids along the shaft compared to nonexpandable needles. Cluster electrodes produced less widening than the other electrodes. CONCLUSION: Visibility and artifacts in all six MR compatible RF electrodes are satisfactory and these electrodes could be used for MR-guided radiofrequency ablation procedures.     

Pre‐operative trans‐catheter arterial chemo‐embolization increases hepatic artery thrombosis after liver transplantation – a retrospective study

Little is known about nonsurgical risk factors for hepatic artery thrombosis (HAT ) after liver transplantation (LT ). We determined risk factors for HAT occurring within 90 days post‐LT and analysed the effect of HAT on graft and patient survival. Donor and recipient demographics, surgery‐related data and outcome in transplants complicated by thrombosis (HAT +) and their matched controls (HAT ?) were compared. Risk factors were assessed by univariate logistic regression. Median (IQR ) is given. A total of 25 HAT occurred among 1035 adult LT (1/1997–12/2014) and 50 controls were manually matched. Donor and recipient demographics were similar. Pre‐LT trans‐catheter arterial chemo‐embolization (TACE ) was more frequent in HAT + (HAT + 20% vs. HAT ? 4%, P = 0.037). HAT + had longer implantation [HAT + 88 min (76–108) vs. HAT ? 77 min (66–93), P = 0.028] and surgery times [HAT + 6.25 h (5.18–7.47) vs. HAT ? 5.25 h (4.33–6.5), P = 0.001]. Early graft dysfunction and sepsis were more frequent in HAT + and hospitalization longer. TACE had the greatest odds ratio in unadjusted analysis (OR : 6, 95% CI : 1.07–33.53, P = 0.03). All but seven grafts were lost after HAT (HAT + 72% vs. HAT ? 36%, P = 0.003); however, patient survival was unaffected (HAT + 79.8% vs. HAT ? 76%, P = 0.75). LT candidates undergoing TACE are at risk of developing HAT early after transplant.