Lymphopenia following pancreaticoduodenectomy is associated with pancreatic fistula formation.

BACKGROUNDS/AIMS: Post-operative pancreatic fistulas (POPF) are a major source of morbidity following pancreaticoduodenectomy (PD). This study aims to investigate if persistent lymphopenia, a known marker of sepsis, can act as an additional marker of POPF with clinical implications that could help direct drain management. METHODS: A retrospective chart review of all patients who underwent PD in a single hospital network from 2008 to 2018. Persistent lymphopenia was defined as lymphopenia beyond post-operative day #3. RESULTS: Of the 201 patients who underwent PD during the study period 161 patients had relevant laboratory data, 81 of whom had persistent lymphopenia. 17 patients with persistent lymphopenia went on to develop a POPF, compared to 7 patients without. Persistent lymphopenia had a negative predictive value of 91.3%. Multivariate analysis revealed only persistent lymphopenia as being independently associated with POPF (HR 2.57, 95% CI 1.07-6.643, p=0.039). Patients with persistent lymphopenia were more likely to have a complication requiring intervention (56.8% vs 35.0%, p<0.001). CONCLUSIONS: Persistent lymphopenia is a readily available early marker of POPF that holds the potential to identify clinically relevant POPF in patients where no surgical drain is present, and to act as an adjunct of drain amylase helping to guide drain management.

Improving the value of palliative surgery by optimizing patient selection: The role of long-term survival on high impact palliative intent operations.

BACKGROUND: In order to better characterize outcomes of palliative surgery (PS), we evaluated patients that experienced top quartile survival to elucidate predictors of high impact PS. METHODS: All PS performed on advanced cancer patients from 2003 to 2017 were identified from a PS database. RESULTS: 167 patients were identified. Multivariate analysis demonstrated the ability to rise from a chair was independently associated with top quartile survival (HR 7.61, 95% CI 2.12-48.82, p=0.008) as was the need for re-operation (HR 2.81, 95% CI 1.26-6.30, p=0.0012). Patients who were able to rise from a chair had significantly prolonged overall survival (320 vs 87 days, p < 0.001). CONCLUSIONS: Although not the primary goal, long-term survival can be achieved following PS and is associated with re-operation and the ability to rise from a chair. These patients experience the benefits of PS for a longer period of time, which in turn maximizes value and positive impact. SUMMARY: Long-term survival and symptom control can be achieved in highly selected advanced cancer patients following palliative surgery. The ability of the patient to independently rise from a chair and the provider to offer a re-operation when indicated are associated with long-term survival following a palliative operation.

Association Between the Economic Environment and the Living Organ Donation Rate: Evidence and Implications.

BACKGROUND: We studied the contribution of the economic environment to an individual's decision to donate an organ by examining the relationship between the unemployment rate and the living donation rate. STUDY DESIGN: We obtained living organ donation data from the Organ Procurement and Transplant Network (OPTN) containing 134,138 organ donation events from 1990 through 2016. We obtained monthly unemployment rates from the Bureau of Labor Statistics (BLS) from 1990 through 2016, and obtained quarterly real gross domestic product (real GDP) by state from the Bureau of Economic Analysis (BEA) from 2005 through 2016. We conducted graphical and statistical analysis with regression modeling using state and time fixed effects. RESULTS: Descriptive graphical plots suggest that unlike the unemployment rate, the donation rate is non-cyclical over time, implying little association between the two factors. This is conferred by a linear regression model using state and calendar month fixed effects, where we found no significant association between the unemployment and donation rates (95% CI [-0.004, 0.008], interpreted as the change in number of donations per 100,000 people associated with 1% change in the unemployment rate). We also did not find any significant association between the real GDP and the donation rates. Subgroup analysis by sex, race, and age also revealed no significant associations. CONCLUSIONS: The unemployment rate and the real GDP do not appear to be associated with the living organ donation rate, suggesting that the economic environment may not play a major role in the decision to donate an organ.

An Update on Iatrogenic Biliary Injuries: Identification, Classification, and Management.

Common bile duct injury is a feared complication of cholecystectomy, with an incidence of 0.1% to 0.6%. A majority of injuries go unnoticed at index operation, and postoperative diagnosis can be difficult. Patient presentation can vary from vague abdominal pain to uncontrolled sepsis and peritonitis. Diagnostic evaluation typically begins with ultrasound or CT scan in the acute setting, and source control is paramount at time of presentation. In a stable patient, hepatobiliary iminodiacetic acid scan can be useful in identifying an ongoing bile leak, which requires intervention. A variety of diagnostic techniques define biliary anatomy. Treatment often requires a multidisciplinary approach.

The Microbiomes of Pancreatic and Duodenum Tissue Overlap and Are Highly Subject Specific but Differ between Pancreatic Cancer and Noncancer Subjects.

BACKGROUND: In mice, bacteria from the mouth can translocate to the pancreas and impact pancreatic cancer progression. In humans, oral bacteria associated with periodontal disease have been linked to pancreatic cancer risk. It is not known if DNA bacterial profiles in the pancreas and duodenum are similar within individuals. METHODS: Tissue samples were obtained from 50 subjects with pancreatic cancer or other conditions requiring foregut surgery at the Rhode Island Hospital (RIH), and from 34 organs obtained from the National Disease Research Interchange. 16S rRNA gene sequencing was performed on 189 tissue samples (pancreatic duct, duodenum, pancreas), 57 swabs (bile duct, jejunum, stomach), and 12 stool samples. RESULTS: Pancreatic tissue samples from both sources (RIH and National Disease Research Interchange) had diverse bacterial DNA, including taxa typically identified in the oral cavity. Bacterial DNA across different sites in the pancreas and duodenum were highly subject specific in both cancer and noncancer subjects. Presence of genus Lactobacillus was significantly higher in noncancer subjects compared with cancer subjects and the relative abundance of Fusobacterium spp., previously associated with colorectal cancer, was higher in cancer subjects compared with noncancer subjects. CONCLUSIONS: Bacterial DNA profiles in the pancreas were similar to those in the duodenum tissue of the same subjects, regardless of disease state, suggesting that bacteria may be migrating from the gut into the pancreas. Whether bacteria play a causal role in human pancreatic cancer needs to be further examined. IMPACT: Identifying bacterial taxa that differ in cancer patients can provide new leads on etiologically relevant bacteria.

A comparison of outcomes between open, laparoscopic and robotic pancreaticoduodenectomy.

BACKGROUND: The advantages and comparison of minimally invasive techniques for pancreaticoduodenectomies have not been fully explored using large national multicenter data. STUDY DESIGN: A retrospective review of NSQIP targeted data from 2014 to 2015 was performed. Demographics and outcomes were compared between open (OPD), laparoscopic (LPD) and robotic pancreaticoduodenectomies (RPD). RESULTS: Of 6827 pancreaticoduodenectomies, 6336 (92.8%) were OPD, 280 (4.1%) were LPD, and 211 (3.1%) were RPD. Compared to OPD, LPD required more post-operative drainage procedures (18.4% vs 13.2%, p = 0.013), had less SSI (3.2% vs 9%, p = 0.001), and had fewer discharges to a new facility (8.1% vs 13%, p = 0.018). Compared to OPD, RPD had less perioperative transfusions (14.2% vs 20.5%, p = 0.026) and more readmissions (23.2% vs 16.7%, p = 0.013). After controlling for differences, LPD was independently associated with decreased 30-day morbidity compared to OPD (OR 0.75, 95% CI 0.56-0.99). There was no difference in 30-day mortality. CONCLUSIONS: This is the first study to compare the outcomes of laparoscopic and robotic pancreaticoduodenectomies to open using the NSQIP database. After controlling for differences between groups, LPD is independently associated with less morbidity. In experienced hands, it appears safe and valuable to pursue refinement of minimally invasive techniques for pancreaticoduodenectomies.

Irreversible electroporation of hepatocellular carcinoma: patient selection and perspectives.

Irreversible electroporation (IRE) is a novel form of tissue ablation that uses high-current electrical pulses to induce pore formation of the cell lipid bilayer, leading to cell death. The safety of IRE for ablation of hepatocellular carcinoma (HCC) has been established. Outcome data for ablation of HCC by IRE are limited, but early results are encouraging and suggest equivalency to the outcomes obtained for thermal ablation for appropriately selected, small (<3 cm) tumors. Long-term oncologic efficacy and histopathologic response data have not been published, and therefore, application of IRE for the treatment of HCC should still be viewed with caution.

FOLFOX+Nab-Paclitaxel (FOLFOX-A) for Advanced Pancreatic Cancer: A Brown University Oncology Research Group Phase I Study.

BACKGROUND: The Brown University Oncology Research Group performed a phase I study to remove irinotecan from FOLFIRINOX (5-fluorouracil, oxaliplatin, irinotecan, and leucovorin) and substitute nab-paclitaxel. METHODS: Patients with newly diagnosed advanced pancreatic adenocarcinoma were eligible. Patients received oxaliplatin 85 mg/m, leucovorin 400 mg/m, and 5-fluorouracil 2400 mg/m with 3 dose levels of nab-paclitaxel (125, 150, and 175 mg/m) every 2 weeks. Dose-limiting toxicities were assessed in the first 2 cycles of treatment. The final dose level was expanded to assess cumulative neurotoxicity. RESULTS: Thirty-five patients were entered; 24 with metastatic and 11 with locally advanced pancreatic cancer. The maximum tolerated dose of nab-paclitaxel was 150 mg/m every 2 weeks with FOLFOX. Cumulative neuropathy was the most important toxicity. Grade 3 neuropathy developed in 2 of the first 6 patients at 10 and 11 cycles of FOLFOX-A. Following an amendment to reduce oxaliplatin to 65 mg/m if grade 2 neuropathy developed, no additional patients developed grade 3 neurotoxicity. Twenty-one of 35 patients (60%) had a partial response. The median survival for patients with metastatic disease was 15 months. CONCLUSIONS: The maximum tolerated dose of nab-paclitaxel is 150 mg/m every 2 weeks with FOLFOX. The regimen of FOLFOX-A represents a promising treatment for pancreatic cancer.

What Shape is Your Resident in? Using a Radar Plot to Guide a Milestone Clinical Competency Discussion.

OBJECTIVE: One of the challenges for program directors (PDs) is to sort and weight the tidal wave of assessments that training programs create in the modern Milestone era. We evaluated whether the use of a radar plot (RP) would be helpful in sorting data and providing a graphic representation of each resident's progress. DESIGN: Using at least 2 different types of assessments for each of the 16 surgical Milestones, the data were ranked and weighted by a predetermined method embedded in a computerized workbook (Excel). This process created a unique 16-spoked RP for each resident (Fig. below). The RP allowed the faculty to see areas of weakness (shown by concavity) and allowed an overall grade calculated as a ratio of the area of the smooth outer circle (faculty expectations, triangles) and the resident's unique radar shape (resident performance, squares). To help us validate our new tool, we looked at whether residents with recent remedial issues "looked" different from residents without remedial issues. RESULTS: Of our 30 categorical residents, 8 had significant areas of concavities, suggesting possible areas of improvement. Of these 8 residents, 4 had been on a remediation program in the last 18 months. The average ratio of performance/expectations was 0.709. The 4 residents on recent remediation had a ratio of 0.616 when compared with 0.723 for the residents without remedial issues (p < 0.009). CONCLUSIONS: Many exciting challenges await PDs, as we evolve to a competency-based evaluation system. The use of an evaluation summary tool using RPs may aid PDs in leading clinical competency discussions and in monitoring a resident's progress over time.

Microwave ablation of focal hepatic malignancies regardless of size: A 9-year retrospective study of 64 patients.

PURPOSE: To retrospectively evaluate the safety and efficacy of microwave ablation (MWA) as treatment for single, focal hepatic malignancies. MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant study. From December 2003 to May 2012, 64 patients were treated with MWA for a single hepatic lesion, in 64 sessions. Hepatocellular carcinoma (HCC) was treated in 25 patients (geometric mean tumor size, 3.33-cm; 95% CI, 2.65-4.18-cm; range, 1.0-12.0-cm), metastatic colorectal cancer (CRC) was treated in 27 patients (geometric mean tumor size, 2.7-cm; 95% CI, 2.20-3.40-cm; range, 0.8-6.0-cm), and other histological-types were treated in 12 patients (geometric mean tumor size, 3.79-cm; 95% CI, 2.72-5.26-cm; range, 1.7-8.0-cm). Kaplan-Meier (K-M) method was used to analyze time event data. Chi-square and correlation evaluated the relationship between tumor size and treatment parameters. RESULTS: Technical success rate was 95.3% (61/64). Treatment parameters were tailored to tumor size; as size increased more antennae were used (p<0.001), treatment with multiple activations increased (p<0.028), and treatment time increased (p<0.001). There was no statistically significant relationship between time to recurrence and tumor size, number of activations, number of antennae, and treatment time. At one-year, K-M analysis predicted a likelihood of local recurrence of 39.8% in HCC patients, 45.7% in CRC metastases patients, and 70.8% in patients with other metastases. Median cancer specific survivals for patients were 38.3 months for HCC patients, 36.3 months for CRC metastases, and 13.9 months for other histological-types. Complications occurred in 23.4% (15/64) of sessions. CONCLUSION: In our sample, tumor size did not appear to impact complete ablation rates or local recurrence rates for focal hepatic malignancies treated with MWA.

Aspartate-ß-hydroxylase induces epitope-specific T cell responses in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) has a poor prognosis due to high recurrence rate. Aspartate-ß-hydroxylase (ASPH) is a highly conserved transmembrane protein, which is over expressed in HCC and promotes a malignant phenotype. The capability of ASPH protein-derived HLA class I and II peptides to generate antigen specific CD4(+) and CD8(+) immune responses is unknown. Therefore, these studies aim to define the epitope specific components required for a peptide based candidate vaccine. Monocyte-derived dendritic cells (DCs) generated from the peripheral blood mononuclear cells (PBMCs) of HCC patients were loaded with ASPH protein. Helper CD4(+) T cells and CD8(+) cytotoxic T lymphocytes (CTLs) were co-incubated with the DCs; T cell activation was evaluated by flow cytometric analysis. Immunoinformatics tools were used to predict HLA class I- and class II-restricted ASPH sequences, and the corresponding peptides were synthesized. The immunogenicity of each peptide in cultures of human PBMCs was determined by IFN-γ ELISpot assay. ASPH protein-loaded DCs activated both CD4(+) and CD8(+) T cells contained within the PBMC population derived from HCC patients. Furthermore, the predicted HLA class I- and class II-restricted ASPH peptides were significantly immunogenic. Both HLA class I- and class II-restricted peptides derived from ASPH induce T cell activation in HCC. We observed that ASPH protein and related peptides were highly immunogenic in patients with HCC and produce the type of cellular immune responses required for generation of anti-tumor activity.

Identification of Nonalcoholic Fatty Liver Disease following Pancreatic Surgery in a Western Cohort Using a Novel Radiographic Technique.

BACKGROUND AND AIMS: While traditional risk factors for the development of nonalcoholic fatty liver disease (NAFLD) relate to metabolic syndrome, several Asian studies have suggested a high rate of de novo NAFLD following pancreaticoduodenectomy (PD). The aim of this study is to identify de novo NAFLD after pancreatic surgery and its associated risk factors. METHODS: A retrospective cohort of patients at a single center that underwent PD or distal pancreatectomy (DP) over 7 years was identified. Pre- and postoperative contrast-enhanced computed tomography scans of the abdomen were reviewed, including attenuation measurements of the liver, spleen, and muscle. Primary outcomes included hepatic attenuation, liver to muscle ratio (LMR), and liver to spleen ratio (LSR). RESULTS: Of the 96 patients (mean age 64.3) included, 70% underwent PD, and 30% underwent DP. The mean LMR decreased significantly from 1.81 to 1.66 (p=0.02), noted only in men. No interaction effect with LMR was observed with surgical type, chemotherapy, blood loss, pancreatic enzyme replacement, or transaminases. LMR decreased in 55% of subjects. CONCLUSIONS: Increased fatty infiltration, as evidence by decreased LMR, was found among men that underwent PD and DP within a year of surgery. This may be related to weight loss and malabsorption and deserves further investigation.

Lenalidomide for second-line treatment of advanced hepatocellular cancer: a Brown University oncology group phase II study.

PURPOSE: To assess the activity and toxicity of lenalidomide for patients with advanced hepatocellular cancer (HCC) previously treated with sorafenib. MATERIALS AND METHODS: Patients with advanced HCC who progressed on or were intolerant to sorafenib were eligible. Patients received lenalidomide 25 mg orally for 1 to 21 days in a 28-day cycle until disease progression or unacceptable toxicities. RESULTS: Forty patients were enrolled and were classified according to the Child-Pugh score: 19 were Child-Pugh A, 16 patients were Child-Pugh B, and 5 were Child-Pugh C. Seventeen patients had extrahepatic disease. Grade 4 neutropenia occurred in 1 of 40 patients (2.5%). Grade 3 fatigue (n=3) and rash (n=4) were the most common nonhematologic toxicities attributable to lenalidomide. Six of 40 patients (15%) had a partial response. Two patients (5%) have not progressed at 36 and 32 months. The median progression-free survival was 3.6 months and the median overall survival was 7.6 months. CONCLUSIONS: Lenalidomide can be administered to patients with advanced HCC and hepatic dysfunction. Promising, and in a small percentage of patients, durable activity has been demonstrated. Investigations are needed to explore the mechanism of action of lenalidomide in HCC.

Assessment of surgical residents in a vascular anastomosis laboratory.

BACKGROUND: We designed a simple, low-cost workshop to teach surgical residents the basic skills of vascular anastomosis. We studied our ability to identify objective procedural and end-product metrics that could be used to measure improvement in vascular anastomotic skill before and after training. MATERIALS AND METHODS: Ten postgraduate year 2 residents without previous vascular surgery experience and four attending surgeons (expert) performed end-to-side anastomosis using a synthetic graft. The residents were taught the basic skills of vascular anastomosis during three didactic workshops. The objective metrics included volume leakage after saline perfusion (leak) and the time needed to complete the anastomosis. Penalty points were assigned for broken sutures, air knots, locking sutures, and failure to maintain an outside-in to inside-out technique. The leak, time, and penalties before and after training were compared. RESULTS: The mean leak was 70.4 ± 13.7 mL and the mean completion time was 18.7 ± 3 min for the pretraining group versus 45.3 ± 10.6 mL (P < 0.01) and 8.5 ± 1 min (P < 0.001), respectively, for the attending group. After training, significant improvement was seen in resident leak (46.7 ± 6.8 mL; P < 0.001) and completion time (14.4 ± 3 min; P < 0.01). Leak was similar between the post-training and expert groups (46.7 ± 6.8 mL and 45.3 ± 10.6 mL, respectively; P = 0.77); however, a significant difference for the completion time remained (14.4 ± 3.0 min and 8.5 ± 1 min, respectively; P < 0.01). The mean number of technical errors improved from 2.7 in the pretraining group to zero for the post-training group after completing the workshop. CONCLUSIONS: We have reported an easy to implement workshop for teaching surgical residents the basic skills of performing vascular anastomosis.

Intra-operative microwave ablation of liver malignancies with tumour permittivity feedback control: a prospective ablate and resect study.

BACKGROUND: Tumour permittivity feedback control is a novel method for microwave ablation (MWA) that theoretically allows for larger, more predictable ablations. This prospective case series evaluates the feasibility and efficacy of MWA of liver malignancies using a device with tumour permittivity feedback control. METHODS: Ten consecutive patients initially determined to be candidates for surgical resection of a liver malignancy underwent intra-operative MWA with tumour permittivity feedback control followed by a surgical resection. A 14-gauge Medwaves microwave antenna was used to deliver a single treatment according to the manufacturer's recommendations. Tumours were assessed grossly as well as by haematoxylin and eosin (H&E) and tetrazolium chloride staining. The primary end point was per cent tumour necrosis. RESULTS: The median maximum ablation diameter measured was 4.1 cm (range 3.0-6.8). The median ablation volume was 8.7 cm(3) (range 4.84-17.55). Six of the 10 tumours demonstrated a pathological complete response (CR). Six of seven tumours ≤ 3 cm demonstrated a pathological CR. Zero of the three tumours ≥ 3 cm had a pathological CR, but all had ≥ 50% tumour necrosis. All patients survived and there were no ablation-related morbidities. DISCUSSION: MWA of liver tumours with tumour permittivity feedback control is feasible and appears effective for the treatment of small (< 3 cm) liver tumours.

Irreversible electroporation for the ablation of liver tumors: are we there yet?

OBJECTIVE: To explore irreversible electroporation (IRE) as a novel, nonthermal form of tissue ablation using high-voltage electrical current to induce pores in the lipid bilayer of cells, resulting in cell death. DATA SOURCES: PubMed searches were performed using the keywords electroporation, IRE, and ablation. The abstracts for the 2012 meetings of both the American Hepato-Pancreato-Biliary Association and the Society for Interventional Radiology were also searched. All articles and abstracts with any reference to electroporation were identified and reviewed. STUDY SELECTION: All studies and abstracts pertaining to electroporation. DATA EXTRACTION: All data pertaining to the safety and efficacy of IRE were extracted from preclinical and clinical studies. Preclinical data detailing the theory and design of IRE systems were also extracted. DATA SYNTHESIS: Preclinical studies have suggested that IRE may have advantages over conventional forms of thermal tumor ablation including no heat sink effect and preservation of the acellular elements of tissue, resulting in less unwanted collateral damage. The early clinical experience with IRE demonstrates safety for the ablation of human liver tumors. Short-term data regarding oncologic outcome is now emerging and appears encouraging. CONCLUSION: Irreversible electroporation is likely to fill a niche void for the ablation of small liver tumors abutting a major vascular structure and for ablation of tumors abutting a major portal pedicle where heat sink and collateral damage must be avoided for maximum efficacy and safety. Studies are still needed to define the short-term and long-term oncologic efficacy of IRE.

Tumor progression-related transmembrane protein aspartate-ß-hydroxylase is a target for immunotherapy of hepatocellular carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) has a poor survival rate due to recurrent intrahepatic metastases and lack of effective adjuvant therapy. Aspartate-ß-hydroxylase (ASPH) is an attractive cellular target since it is a highly conserved transmembrane protein overexpressed in both murine and human HCC tumors, and promotes a malignant phenotype as characterized by enhanced tumor cell migration and invasion. METHODS: Dendritic cells (DCs), expanded and isolated from the spleen, were incubated with a cytokine cocktail to optimize IL-12 secretion and co-stimulatory molecule expression, then subsequently loaded with ASPH protein for immunization. Mice were injected with syngeneic BNL HCC tumor cells followed by subcutaneous inoculation with 5-10×10(5) ASPH loaded DCs using a prophylactic and therapeutic experimental approach. Tumor infiltrating lymphocytes (TILs) were characterized, and their role in producing anti-tumor effects determined. The immunogenicity of ASPH protein with respect to activating antigen specific CD4+ T cells derived from human peripheral blood mononuclear cells (PBMCs) was also explored. RESULTS: We found that immunotherapy with ASPH-loaded DCs suppressed and delayed established HCC and tumor growth when administered prophylactically. Ex-vivo re-stimulation experiments and in vivo depletion studies demonstrated that both CD4+ and CD8+ cells contributed to anti-tumor effects. Using PBMCs derived from healthy volunteers and HCC patients, we showed that ASPH stimulation led to significant development of antigen-specific CD4+ T-cells. CONCLUSIONS: Immunization with ASPH-loaded DCs has substantial anti-tumor effects which could reduce the risk of HCC recurrence.

Irreversible electroporation of the liver and liver hilum in swine.

BACKGROUND: Irreversible electroporation (IRE) is a novel, non-thermal form of ablation. We studied the safety and efficacy of IRE for the ablation of liver tissue around the liver hilum. We also studied the ability of triphenyltetrazolium chloride staining (TTC) to predict the zone of ablation after IRE. METHODS: Eight swine underwent 20 ablations of the liver and liver hilum. Two monopolar probes were positioned 2 cm apart. IRE was performed using 90 pulses of 2500-3000 V/cm. IRE treatments were performed from 15 min to 14 days (n= 4) before sacrifice. RESULTS: All animals survived. No major complications were encountered. Ablation width ranged from 2.27 to 4.45 cm and ablation height ranged from 1.5 to 1.8 cm. TTC staining demonstrated the zone of ablation in all animals. Hepatocyte necrosis occurs immediately adjacent to large central veins without evidence of heat sink. Bile ducts, portal veins and hepatic arteries appear to be more resistant to the effects of IRE. CONCLUSIONS: IRE appears to be safe and effective for liver tissue ablation in the liver hilum. The portal structures appear more resistant to the effects of IRE. TTC staining can predict the zone of IRE ablation as early as 15 min after treatment.

Optimizing resection for "responding" hepatic metastases after neoadjuvant chemotherapy.

Fifty percent of patients with colorectal cancer will develop metastases at some time during their disease, with the liver being the most common site. Recent advances in the treatment of metastatic colorectal cancer have led to a change in treatment paradigm. What follows is a review of the surgical management of hepatic colorectal metastases responding to neoadjuvant chemotherapy. In addition, the complexity of treating patients with "disappearing" colorectal liver metastases is discussed.

Irreversible electroporation of the pancreas in swine: a pilot study.

BACKGROUND: Irreversible electroporation (IRE) is a novel, non-thermal method of tissue ablation using short pulses of high-voltage DC current to ablate tissue. METHODS: Irreversible electroporation of the pancreas was performed in four domestic female swine using two monopolar probes spaced 9-15 mm apart. Ninety pulses of 1500 V/cm were delivered for each ablation. RESULTS: All animals survived for their designated times of 2 h (n = 1), 2 days (n = 1) and 14 days (n = 2), respectively. No procedure-related complications occurred. Three animals in which probes had been spaced at intervals of 10 ± 1 mm showed evidence of irreversible ablation, with ablation height ranging from < 10 mm to 21 mm and ablation width ranging from < 10 mm to 16 mm by gross appearance and triphenyltetrazolium chloride (TTC) staining. The only animal in which probes had been spaced at intervals of 15 mm did not show evidence of irreversible ablation at 2 weeks. This may be secondary to the wider probe spacing and relatively low voltage, which results in a mostly reversible form of electroporation without cell death. CONCLUSIONS: Irreversible electroporation appears to be a safe method for pancreas tissue ablation. Staining with TTC can predict the zone of IRE ablation within 2 h of treatment.