Alleviation of acute radiation-induced bone marrow failure in mice with human fetal placental stromal cell therapy.

PURPOSE: Selected placental mesenchymal stromal cells isolated from the fetal mesenchymal placental tissues (f-hPSCs) were tested as cell therapy of lethal acute radiation syndrome (ARS) with bone marrow regeneration and induced extramedullary hematopoiesis. METHODS AND MATERIALS: f-hPSCs were isolated from the chorionic plate of human placentae and further expanded in regular culture conditions. 2 × 106 f-hPSCs were injected on days 1 and 4 to 8-Gy total body irradiated (TBI) C3H mice, both intramuscularly and subcutaneously. Pre-splenectomized TBI mice were used to test the involvement of extramedullary spleen hematopoiesis in the f-hPSC-induced hematopoiesis recovery in the TBI mice. Weight and survival of the mice were followed up within the morbid period of up to 23 days following irradiation. The role of hematopoietic progenitors in the recovery of treated mice was evaluated by flow cytometry, blood cell counts, and assay of possibly relevant growth factors. RESULTS AND CONCLUSIONS: The survival rate of all groups of TBI f-hPSC-treated mice at the end of the follow-up was dramatically elevated from < 10% in untreated to ~ 80%, with a parallel regain of body weight, bone marrow (BM) recovery, and elevated circulating progenitors of blood cell lineages. Blood erythropoietin levels were elevated in all f-hPSC-treated mice. Extramedullary splenic hematopoiesis was recorded in the f-hPSC-treated mice, though splenectomized mice still had similar survival rate. Our findings suggest that the indirect f-hPSC life-saving therapy of ARS may also be applied for treating other conditions with a failure of the hematopoietic system and severe pancytopenia.

Irreversible electroporation ablation: creation of large-volume ablation zones in in vivo porcine liver with four-electrode arrays.

PURPOSE: To prospectively determine optimal parameters with which to achieve defined large target zones of coagulation by using irreversible electroporation (IRE) with four-electrode arrays and the time needed to achieve this treatment effect in an in vivo animal model. MATERIALS AND METHODS: This study was approved by the animal care and use committee. Ultrasonography (US)-guided IRE ablation (n = 90) was performed in vivo in 69 pig livers with an array of four electrodes (18 gauge) and an electroporation generator. Cardiac-gated 100-µsec IRE pulses were applied sequentially between the six sets of electrode pairs at 2250-3000 V. Multiple algorithms of energy deposition and electrode configuration were studied, including interelectrode spacing (1.5-2.5 cm), number of IRE pulses applied consecutively to each electrode pair (10, 20, 50, and 100), and number of times per cycle each electrode pair was activated (one to 10). Resultant zones of treatment were measured with US 1.5-3 hours after IRE and confirmed at gross and histopathologic examination. Data and ablation times were compared to determine the optimal algorithms with which to achieve 4-7-cm areas of treatment effect in the shortest time possible. In addition, the IRE current applied was correlated with ablation size. Data were analyzed by using analysis of variance with multiple comparisons, t tests, or nonparametric statistics. RESULTS: For 2.5-cm spacing, ablation diameter was increased by increasing either the overall time of energy application or the number of cycles of 20 pulses (P < .01 for both). IRE application of less than four cycles (or continuous IRE application of 100 pulses) did not result in contiguous ablation. However, sequentially increasing the number of cycles of IRE from four to 10 increased both the electrical current applied (from 14.4 A ± 0.4 to 17.6 A ± 0.7, P = .0004) and ablation diameter (from 5.6 cm ± 0.3 to 6.6 cm ± 0.3, P = .001). Although division of application into cycles did not alter coagulation at 2.0- and 1.5-cm spacing, application of energy to diagonal electrode pairs increased coagulation. Thus, one 100-pulse cycle (11.0 minutes ± 1.4) produced 4.8 cm ± 0.3 of ablation for 2.0-cm spacing with diagonal pairs but only 4.1 cm ± 0.3 of ablation without diagonal pairs (7.5 minutes ± 1.0, P < .03 for both). CONCLUSION: With four-electrode arrays, IRE can create large contiguous zones of treatment effect in clinically acceptable ablation times; parameters can be tailored to achieve a wide range of ablation sizes. Cyclical deposition of IRE application is beneficial, particularly for larger interprobe spacing, most likely owing to alterations of electrical conductivity that occur after successive applications of IRE energy.

A novel totally internal laparoscopic liver retractor.

INTRODUCTION: Minimally invasive surgery is still in evolution. Throughout the past two decades numerous devices have been developed to enable safer and faster procedures, including anastomosis creating devices, energy sources, and superior imaging. However, retraction capabilities were put aside and currently, organ laparoscopic retraction is based on standard laparoscopic tools. In the era of minimizing the number of ports and shrinking their size, our aim was to develop internal retraction device that could be placed in the peritoneal cavity through a standard trocar, positioned for adequate retraction, and left in place for the entire procedure. These devices would obviate the need for inserting ports dedicated for retraction only and hence contribute to the reduction of the number of incisions. Herein, we present our initial experience with a novel internal liver retractor. MATERIALS AND METHODS: The Endolift retractor is a simple telescopic rod that has anchoring claws at each end. It can be inserted using 5 mm standard trocar using a dedicated applier and anchored to the peritoneum beside the liver edges thereby lifting the undersurface of the liver and exposing the organs underneath. To achieve retraction of the left lateral segment, the Endolift retractor is anchored lateral to the right diaphragmatic crus on 1 side and lateral to the falciform ligament on the other. RESULTS: A total of 14 operations were performed using the Endolift retractor for liver retraction including antireflux procedure, robotic-assisted Heller's myotomy, bariatric procedures, and bile duct exploration. The left lobe of the liver was adequately retracted and enabled access to the operating field. Repositioning was easily performed with progression of the surgery when necessary. CONCLUSIONS: Internal retraction devices such as the Endolift retractor for liver retraction are one step further in minimizing trauma to the abdominal wall during minimal invasive surgery. It obviates the need for extra incisions, frees up the surgeons' hands, and may enable performing complicated laparo-endoscopic single-site laparoscopy and natural orifice transluminal endoscopic surgery.

On-site education of VEGF-recruited monocytes improves their performance as angiogenic and arteriogenic accessory cells.

Adult neovascularization relies on the recruitment of monocytes to the target organ or tumor and functioning therein as a paracrine accessory. The exact origins of the recruited monocytes and the mechanisms underlying their plasticity remain unclear. Using a VEGF-based transgenic system in which genetically tagged monocytes are conditionally summoned to the liver as part of a VEGF-initiated angiogenic program, we show that these recruited cells are derived from the abundant pool of circulating Ly6C(hi) monocytes. Remarkably, however, upon arrival at the VEGF-induced organ, but not the naive organ, monocytes undergo multiple phenotypic and functional changes, endowing them with enhanced proangiogenic capabilities and, importantly, with a markedly increased capacity to remodel existing small vessels into larger conduits. Notably, monocytes do not differentiate into long-lived macrophages, but rather appear as transient accessory cells. Results from transfers of presorted subpopulations and a novel tandem transfer strategy ruled out selective recruitment of a dedicated preexisting subpopulation or onsite selection, thereby reinforcing active reprogramming as the underlying mechanism for improved performance. Collectively, this study uncovered a novel function of VEGF, namely, on-site education of recruited "standard" monocytes to become angiogenic and arteriogenic professional cells, a finding that may also lend itself for a better design of angiogenic therapies.

Irreversible electroporation: treatment effect is susceptible to local environment and tissue properties.

PURPOSE: To study the effects of the surrounding electrical microenvironment and local tissue parameters on the electrical parameters and outcome of irreversible electroporation (IRE) ablation in porcine muscle, kidney, and liver tissue. MATERIALS AND METHODS: Animal Care and Use Committee approval was obtained, and National Institutes of Health guidelines were followed. IRE ablation (n = 90) was applied in muscle (n = 44), kidney (n = 28), and liver (n = 18) tissue in 18 pigs. Two electrodes with tip exposure of 1.5-2 cm were used at varying voltages (1500-3000 V), pulse repetitions (n = 70-100), pulse length (70-100 µsec), and electrode spacing (1.5-2 cm). In muscle tissue, electrodes were placed exactly parallel, in plane, or perpendicular to paraspinal muscle fibers; in kidney tissue, in the cortex or adjacent to the renal medulla; and in liver tissue, with and without metallic or plastic plates placed 1-2 cm from electrodes. Ablation zones were determined at gross pathologic (90-120 minutes after IRE) and immunohistopathologic examination (6 hours after) for apoptosis and heat-shock protein markers. Multivariate analysis of variance with multiple comparisons and/or paired t tests and regression analysis were used for analysis. RESULTS: Mean (± standard deviation) ablation zones in muscle were 6.2 cm ± 0.3 × 4.2 cm ± 0.3 for parallel electrodes and 4.2 cm ± 0.8 × 3.0 cm ± 0.5 for in-plane application. Perpendicular orientation resulted in a cross-shaped zone. Orientation significantly affected IRE current applied (28.5-31.7A for parallel, 29.5-39.7A for perpendicular; P = .003). For kidney cortex, ovoid zones of 1.5 cm ± 0.1 × 0.5 cm ± 0.0 to 2.5 cm ± 0.1 × 1.3 cm ± 0.1 were seen. Placement of electrodes less than 5 mm from the medullary pyramids resulted in treatment effect arcing into the collecting system. For liver tissue, symmetric 2.7 cm ± 0.2 × 1.4 cm ± 0.3 coagulation areas were seen without the metallic plate but asymmetric coagulation was seen with the metallic plate. CONCLUSION: IRE treatment zones are sensitive to varying electrical conductivity in tissues. Electrode location, orientation, and heterogeneities in local environment must be considered in planning ablation treatment. Online supplemental material is available for this article.

Irreversible electroporation ablation: is all the damage nonthermal?

PURPOSE: To determine whether high-dose irreversible electroporation (IRE) ablation induces thermal effects in normal liver tissue. MATERIALS AND METHODS: Animal care and use committee approval was obtained prior to the experiments. IRE ablation (n = 78) was performed by a single four-person team in vivo in 22 porcine livers by applying electric current to two 1.3-cm-diameter circular flat-plate electrodes spaced 1 cm apart. Cardiac-gated IRE pulses (n = 40-360) were systematically applied at varying voltages (1500-2900 V). End temperatures at the ablation zone center were measured and were correlated with ablation time, energy parameters, and resultant treatment effect as determined at gross pathologic and histopathologic examination. Temperatures were then monitored at the center and periphery of four ablations created by using a four-electrode IRE array (3000 V, 90 pulses per electrode pair). Data were analyzed by using multivariate analysis of variance with multiple comparisons and/or paired t tests and regression analysis, as appropriate. RESULTS: Temperature rose above the 34°C baseline after IRE in all flat-plate experiments and correlated linearly (R(2) = 0.39) with IRE "energy dose" (product of voltage and number of pulses) and more tightly in univariate analysis with both voltage and number of pulses. Thus, mean temperatures as high as 86°C ± 3 (standard deviation) were seen for 2500 V and 270 pulses. Ablations of 90 pulses or more at 2500 V produced temperatures of 50°C or greater and classic gross and histopathologic findings of thermal coagulation (pyknotic nuclei and streaming cytoplasm). For lower IRE doses (ie, 2100 V, 90 pulses), temperatures remained below 45°C, and only IRE-associated pathologic findings (ie, swollen sinusoids, dehydrated cells, and hemorrhagic infiltrate) were seen. For the four-electrode arrays, temperatures measured 54.2°C ± 6.1 at the electrode surfaces and 38.6°C ± 3.2 at the ablation zone margin. CONCLUSION: In some conditions of high intensity, IRE can produce sufficient heating to induce "white zone" thermal coagulation. While this can be useful in some settings to increase tumor destruction, further characterization of the thermal profile created with clinical electrodes and energy parameters is therefore needed to better understand the best ways to avoid unintended damage when ablating near thermally sensitive critical structures.

Complications of high grade liver injuries: management and outcomewith focus on bile leaks.

BACKGROUND: Although liver injury scale does not predict need for surgical intervention, a high-grade complex liver injury should alert the physician to expect an increased risk of hepatic complications following trauma. The aim of the current study was to define hepatic related morbidity in patients sustaining high-grade hepatic injuries that could be safely managed non-operatively. PATIENTS AND METHODS: This is a retrospective study of patients with liver injury admitted to Hadassah-Hebrew University Medical Centre over a 10-year period. Grade 3-5 injuries were considered to be high grade. Collected data included the number and types of liver-related complications. Interventions which were required for these complications in patients who survived longer than 24 hours were analysed. RESULTS: Of 398 patients with liver trauma, 64 (16%) were found to have high-grade liver injuries. Mechanism of injury was blunt trauma in 43 cases, and penetrating in 21. Forty patients (62%) required operative treatment. Among survivors 22 patients (47.8%) developed liver-related complications which required additional interventional treatment. Bilomas and bile leaks were diagnosed in 16 cases post-injury. The diagnosis of bile leaks was suspected with abdominal CT scan, which revealed intraabdominal collections (n = 6), and ascites (n = 2). Three patients had continuous biliary leak from intraabdominal drains left after laparotomy. Nine patients required ERCP with biliary stent placement, and 2 required percutaneous transhepatic biliary drainage. ERCP failed in one case. Four angioembolizations (AE) were performed in 3 patients for rebleeding. Surgical treatment was found to be associated with higher complication rate. AE at admission was associated with a significantly higher rate of biliary complications. There were 24 deaths (37%), the majority from uncontrolled haemorrhage (18 patients). There were only 2 hepatic-related mortalities due to liver failure. CONCLUSIONS: A high complication rate following high-grade liver injuries should be anticipated. In patients with clinical evidence of biliary complications, CT scan is a useful diagnostic and therapeutic tool. AE, ERCP and temporary internal stenting, together with percutaneous drainage of intra-abdominal or intrahepatic bile collections, represents a safe and effective strategy for the management of complications following both blunt and penetrating hepatic trauma.