Risk factors for post-discharge venous thromboembolism in patients undergoing colorectal resection: a NSQIP analysis.

BACKGROUND: Extended thromboprophylaxis after abdominal and pelvic cancer surgery to prevent venous thromboembolic events (VTE) is recommended but adherence is sub-optimal. Identifying patients at highest risk for post-discharge events may allow for selective extended thromboprophylaxis. The aim of our study was to identify the different risk factors of venous thromboembolism for in-hospital and post-discharge events. METHODS: The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) 2012-2016 database was queried for all patients having colorectal resection. Primary outcome was postoperative VTE occurrence within 30 days. A multinomial logistic regression was performed to identify in-hospital and post-discharge predictors of VTE, adjusting for potential confounders. RESULTS: Out of 260,258 patients, 5381 (2.1%) developed VTE. A total of 3442 (1.3%) were diagnosed during the initial hospital stay and 1929 (0.8%) post-discharge. Risk factors for in-hospital and post-discharge VTE were different as patients with an in-hospital event were more likely to be older, male, known for preoperative steroid use, have poor functional status, significant weight loss, preoperative sepsis, prolonged operative time, undergoing an emergency operation. In the post-discharge setting, steroid use, poor functional status, preoperative sepsis, and postoperative complications remained significant. Postoperative complications were the strongest predictor of in-hospital and post-discharge VTE. Patients with inflammatory bowel disease had a higher risk of VTE than patients with malignancy for both in-patient and post-discharge events. CONCLUSIONS: Patients at high-risk for post-discharge events have different characteristics than those who develop VTE in-hospital. Identifying this specific subset of patients at highest risk for post-discharge VTE may allow for the selective use of prolonged thromboprophylaxis.

Combined sorafenib and yttrium-90 radioembolization for the treatment of advanced hepatocellular carcinoma.

BACKGROUND AND AIMS: In this pilot study, we assessed the safety and tolerability of combining sorafenib with 90Y radioembolization for the treatment of unresectable hepatocellular carcinoma (hcc). METHODS: The study, conducted prospectively during 2009-2012, included eligible patients with unresectable hcc and a life expectancy of at least 12 weeks. Each patient received sorafenib (400 mg twice daily) for 6-8 weeks before 90Y treatment. Safety and tolerability were assessed. RESULTS: Of the 40 patients enrolled, 29 completed treatment (combined therapy). In the initial cohort, the most common cause of hcc was hepatitis C (32.5%), and most patients were staged Child A (82.5%). The 29 patients who completed the study had similar baseline characteristics. Grades 1 and 2 toxicities accounted for 77.8% of all adverse events reported. The most common toxicities reported were fatigue (19.0%), alteration in liver function (7.9%), and diarrhea (6.3%). There were 12 grade 3 and 2 grade 4 toxicity events reported. One patient died of liver failure within 30 days after treatment. During the study, the sorafenib dose was reduced in 6 patients (20.7%), and sorafenib had to be interrupted in 4 patients (13.8%) and discontinued in 4 patients (13.8%). The disease control rate was 72.4% per the modified Response Evaluation Criteria in Solid Tumors, and tumour necrosis was observed in 82.8% of patients. Overall survival in patients undergoing combined therapy was 12.4 months. CONCLUSIONS: Preliminary results demonstrate the safety and tolerability of combining 90Y radioembolization and sorafenib for advanced hcc. A larger prospective study is needed to determine the extent of the survival benefit.

Eastern Canadian Gastrointestinal Cancer Consensus Conference 2016.

The annual Eastern Canadian Gastrointestinal Cancer Consensus Conference 2016 was held in Montreal, Quebec, 5-7 February. Experts in radiation oncology, medical oncology, surgical oncology, and infectious diseases involved in the management of patients with gastrointestinal malignancies participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses multiple topics: ■ Follow-up and survivorship of patients with resected colorectal cancer■ Indications for liver metastasectomy■ Treatment of oligometastases by stereotactic body radiation therapy■ Treatment of borderline resectable and unresectable pancreatic cancer■ Transarterial chemoembolization in hepatocellular carcinoma■ Infectious complications of antineoplastic agents.

Prospective iterative trial of proteasome inhibitor-based desensitization.

A prospective iterative trial of proteasome inhibitor (PI)-based therapy for reducing HLA antibody (Ab) levels was conducted in five phases differing in bortezomib dosing density and plasmapheresis timing. Phases included 1 or 2 bortezomib cycles (1.3 mg/m(2) × 6-8 doses), one rituximab dose and plasmapheresis. HLA Abs were measured by solid phase and flow cytometry (FCM) assays. Immunodominant Ab (iAb) was defined as highest HLA Ab level. Forty-four patients received 52 desensitization courses (7 patients enrolled in multiple phases): Phase 1 (n = 20), Phase 2 (n = 12), Phase 3 (n = 10), Phase 4 (n = 5), Phase 5 (n = 5). iAb reductions were observed in 38 of 44 (86%) patients and persisted up to 10 months. In Phase 1, a 51.5% iAb reduction was observed at 28 days with bortezomib alone. iAb reductions increased with higher bortezomib dosing densities and included class I, II, and public antigens (HLA DRß3, HLA DRß4 and HLA DRß5). FCM median channel shifts decreased in 11/11 (100%) patients by a mean of 103 ± 54 mean channel shifts (log scale). Nineteen out of 44 patients (43.2%) were transplanted with low acute rejection rates (18.8%) and de novo DSA formation (12.5%). In conclusion, PI-based desensitization consistently and durably reduces HLA Ab levels providing an alternative to intravenous immune globulin-based desensitization.

Portal vein embolization and its effect on tumour progression for colorectal cancer liver metastases.

BACKGROUND: The aim of this study was to evaluate the long-term outcomes of patients with colorectal cancer liver metastasis (CRCLM) exhibiting disease progression after portal vein embolization (PVE). METHODS: Patients with CRCLM requiring PVE before hepatectomy between 2003 and 2014 were included. Clinical variables, and liver and tumour volumes determined by three-dimensional CT volumetry were assessed before and after PVE. Overall and disease-free survival data were obtained. Univariable and multivariable logistic regression analyses were performed to identify predictors of tumour progression after PVE. RESULTS: Of 141 patients who underwent PVE, 93 (66.0 per cent) had tumour progression and 17 (12.1 per cent) developed new contralateral lesions. Significantly fewer patients had resectable disease in the group with disease progression than among those with stable disease: 43 (46 per cent) of 93 versus 36 (75 per cent) of 48 respectively (P = 0.001). Median survival was similar in patients with and without tumour growth after PVE: 22.5 versus 26.0 months for patients with unresectable tumours (P = 0.706) and 46.2 versus 52.2 months for those with resectable disease (P = 0.953). However, disease-free survival for patients with tumour progression after PVE was shorter than that for patients with stable disease (6.0 versus 20.2 months; P = 0.045). Response to neoadjuvant chemotherapy was the only significant factor associated with tumour progression in multivariable analysis. CONCLUSION: Tumour progression after PVE did not affect overall survival, but patients with resected tumours who had tumour growth after embolization experienced earlier recurrence. A borderline response to neoadjuvant chemotherapy seemed to be associated with tumour progression after PVE.

High Field Emission Current Density from Patterned Carbon Nanotube Field Emitter Arrays with Random Growth.

High field emission (FE) current density from carbon nanotube (CNT) arrays grown on lithographically patterned silicon substrates is reported. A typical patterned field emitter array consists of bundles of nanotubes separated by a fixed gap and spread over the entire emission area. Emission performance from such an array having randomly oriented nanotube growth within each bundle is reported for different bundle sizes and separations. One typical sample with aligned CNTs within the bundle is also examined for comparison. It is seen that the current density from an array having random nanotube growth within the bundles is appreciably higher as compared to its aligned counterpart. The influence of structure on FE current densities as revealed by Raman spectroscopy is also seen. It is also observed that current density depends on edge length and increases with the same for all samples under study. Highest current density of -100 mA cm(-2) at an applied field of 5 V/µm is achieved from the random growth patterned sample with a bundle size of 2 µm and spacing of 4 µm between the bundles.

Establishing a clinic-based pancreatic cancer and periampullary tumour research registry in Quebec.

BACKGROUND: Enrolling patients in studies of pancreatic ductal adenocarcinoma (pdac) is challenging because of the high fatality of the disease. We hypothesized that a prospective clinic-based study with rapid ascertainment would result in high participation rates. Using that strategy, we established the Quebec Pancreas Cancer Study (qpcs) to investigate the genetics and causes of pdac and other periampullary tumours (pats) that are also rare and underrepresented in research studies. METHODS: Patients diagnosed with pdac or pat were introduced to the study at their initial clinical encounter, with a strategy to enrol participants within 2 weeks of diagnosis. Patient self-referrals and referrals of unaffected individuals with an increased risk of pdac were also accepted. Family histories, epidemiologic and clinical data, and biospecimens were collected. Additional relatives were enrolled in families at increased genetic risk. RESULTS: The first 346 completed referrals led to 306 probands being enrolled, including 190 probands affected with pdac, who represent the population focus of the qpcs. Participation rates were 88.4% for all referrals and 89.2% for pdac referrals. Family history, epidemiologic and clinical data, and biospecimens were ascertained from 91.9%, 54.6%, and 97.5% respectively of patients with pdac. Although demographics and trends in risk factors in our patients were consistent with published statistics for patients with pdac, the qpcs is enriched for families with French-Canadian ancestry (37.4%), a population with recurrent germ-line mutations in hereditary diseases. CONCLUSIONS: Using rapid ascertainment, a pdac and pat research registry with high participation rates can be established. The qpcs is a valuable research resource and its enrichment with patients of French-Canadian ancestry provides a unique opportunity for studies of heredity in these diseases.

(18)F-Fluorodeoxyglucose positron-emission tomography could have a prognostic role in patients with advanced hepatocellular carcinoma.

INTRODUCTION: We set out to evaluate the prognostic value of (18)F-fluorodeoxyglucose positron-emission tomography (pet) in patients with advanced (non-transplant-eligible) hepatocellular carcinoma (hcc) and to evaluate the correlation between standardized uptake values (suvs) and survival outcomes. METHODS: We identified patients with hcc who, from 2005 to 2013, underwent pet imaging before any treatment. This retrospective study from our hcc database obtained complete follow-up data for the 63 identified patients. RESULTS: Of the 63 patients, 10 underwent surgical resection, and 59 underwent locoregional therapy. In this cohort, 28 patients were pet-positive (defined as any lesion with a suv ≥ 4.0) before any therapy was given, and 35 patients were pet negative (all lesions with a suv < 4.0). On survival analysis, median survival was greater for the pet-negative than for the pet-positive patients: 29 months (range: 16.3-41.1 months) versus 12 months (range: 4.0-22.1 months) respectively, p = 0.0241. The pet-positive patients more often had large tumours (≥5 cm), poor differentiation, and extrahepatic disease, reflecting more aggressive tumours. On multivariate analysis, only pet positivity was associated with poor survival (p = 0.049). CONCLUSIONS: Compared with pet-positive patients, pet-negative patients with hcc experienced longer survival. Imaging by pet can be of value in early prognostication for patients with hcc, especially patients receiving locoregional therapy for whom pathologic tumour differentiation is rarely available. This potential role for pet requires further validation in a prospective study.

Bevacizumab-based therapy for colorectal cancer: experience from a large Canadian cohort at the Jewish General Hospital between 2004 and 2009.

BACKGROUND: Before its regulatory approval in Canada, bevacizumab to treat patients with colorectal cancer (crc) was accessed through the Bevacizumab Expanded Access Trial and a special-access program at the Jewish General Hospital. We retrospectively evaluated patient outcomes in that large cohort. METHODS: All patients (n = 196) had metastatic crc, were bevacizumab-naïve, and received bevacizumab in combination with chemotherapy at the Jewish General Hospital between 2004 and 2009. We collected patient demographics and clinical characteristics; relevant medical history, disease stage and tumour pathology at diagnosis; type, duration, and line of therapy; grades 3 and 4 adverse events (aes), time to disease progression (ttp), and overall survival (os) from diagnosis. RESULTS: Median follow-up was 36.0 months. Median ttp was 8.0 months [95% confidence interval (ci): 7.0 to 9.0 months). Median os was 41.0 months (95% ci: 36.0 to 47.0 months). Of the 40 grades 3 and 4 bevacizumab-related aes experienced by 38 patients (19.4%), the most common were thrombocytopenia (n = 17), deep-vein thrombosis (n = 6), pulmonary embolism (n = 4), and hypertension (n = 3). CONCLUSIONS: In an expanded access setting, our data reflect the efficacy and safety of bevacizumab-based therapy in the controlled post-registration clinical trial setting.

A real-life experience using panitumumab in chemo-refractory metastatic colorectal cancer patients: a retrospective analysis at the Jewish General Hospital, 2009-2012.

BACKGROUND: Panitumumab is a fully human monoclonal antibody, directed against the epidermal growth factor receptor, that was shown to be effective in third-line metastatic colorectal cancer. We performed a retrospective analysis of patients with chemo-refractory non-KRAS-mutated metastatic colorectal cancer, who received panitumumab at the Jewish General Hospital in Montreal, Canada, between 2009 and 2012. METHODS: This chart review included 44 patients (median age: 60 years; performance status: 0-3), of whom 50% had already received three lines of treatment. The primary endpoint was progression-free survival (pfs). Secondary endpoints were overall survival and safety. Tumour progression was determined by radiologic assessments performed once every 3 months per clinical guidelines or by clinical deterioration as determined by the clinician-investigator. RESULTS: In our sample, median pfs was 21.86 ± 5.23 weeks (95% confidence interval: 12.9 to 36.9 weeks) and overall survival was 35.14 ± 7.75 weeks (95% confidence interval: 25.6 to 73.4 weeks) with a median of 5 cycles of panitumumab treatment. The most frequently reported toxicities with panitumumab were skin toxicity (16.2% grade 3) and hypomagnesemia (10.8% grade 3). No infusion reactions were reported. CONCLUSIONS: Despite a small sample size from a single institution, our survival and efficacy data are encouraging and comparable to results obtained from the registration panitumumab trial. Our findings suggest that panitumumab can be effective and tolerable in a real-world setting.

Magnitude of change in alpha-fetoprotein in response to transarterial chemoembolization predicts survival in patients undergoing liver transplantation for hepatocellular carcinoma.

BACKGROUND: Downsizing strategies are often attempted for patients with hepatocellular carcinoma (hcc) before liver transplantation (lt). The objective of the present study was to determine clinical predictors of favourable survival outcomes after transarterial chemoembolization (tace) before lt for hcc outside the Milan criteria, so as to better select candidates for this strategy. METHODS: In this retrospective study, patients with hcc tumours either beyond Milan criteria (single lesion > 5 cm, 3 lesions with 1 or more > 3 cm) or at the upper limit of Milan criteria (single lesions between 4.1 cm and 5.0 cm), with a predicted waiting time of more than 3 months, received carboplatin-based tace treatments. Exclusion criteria for tace included Child-Pugh C cirrhosis or the presence of portal vein invasion or extrahepatic disease on imaging. Only patients without tumour progression after tace underwent lt. RESULTS: Of 160 hcc patients who received liver grafts between 1997 and 2010, 35 were treated with tace preoperatively. The median of the sum of tumour diameters was 6.7 cm (range: 4.8-8.5 cm), which decreased with tace to 5.0 cm (range: 3.3-7.0 cm) at transplantation (p < 0.0004). The percentage drop in alpha-fetoprotein (αfp) was a positive predictor (p = 0.0051) and the time from last tace treatment to transplantation was a negative predictor (p < 0.0001) for overall survival. CONCLUSIONS: The percentage drop in αfp and a shorter time from the final tace treatment to transplantation significantly predicted improved overall survival after lt for hcc downsized with tace. As a serum marker, αfp should be followed when tace is used as a strategy to stabilize or downsize hcc lesions before lt.

Reducing de novo donor-specific antibody levels during acute rejection diminishes renal allograft loss.

The effect of de novo DSA detected at the time of acute cellular rejection (ACR) and the response of DSA levels to rejection therapy on renal allograft survival were analyzed. Kidney transplant patients with acute rejection underwent DSA testing at rejection diagnosis with DSA levels quantified using Luminex single-antigen beads. Fifty-two patients experienced acute rejection with 16 (31%) testing positive for de novo DSA. Median follow-up was 27.0 +/- 17.4 months postacute rejection. Univariate analysis of factors influencing allograft survival demonstrated significance for African American race, DGF, cytotoxic PRA >20% (current) and/or >50% (peak), de novo DSA, C4d and repeat transplantation. Multivariate analysis showed only de novo DSA (6.6-fold increased allograft loss risk, p = 0.017) to be significant. Four-year allograft survival was higher with ACR (without DSA) (100%) than mixed acute rejection (ACR with DSA/C4d) (65%) or antibody-mediated rejection (35%) (p < 0.001). Patients with >50% reduction in DSA within 14 days experienced higher allograft survival (p = 0.039). De novo DSAs detected at rejection are associated with reduced allograft survival, but prompt DSA reduction was associated with improved allograft survival. DSA should be considered a potential new end point for rejection therapy.

Delayed graft function has an equally bad impact on deceased donor renal graft survival in both standard criteria donors and expanded criteria donors.

INTRODUCTION: The use of expanded criteria donors (ECDs) is still limited because of inferior graft survival compared to standard criteria donors (SCDs). We assessed the impact of immediate graft function (IGF) on renal graft survival among recipients of SCD and ECD grafts to determine whether these kidneys performed equally well under "ideal" conditions favoring IGF. METHODS: We included all cadaveric renal transplants performed from 1990 to 2002 (n = 335). Delayed graft function (DGF) was defined as the need for dialysis in the first 7 days posttransplant. Slow graft function (SGF) and IGF were defined as a serum creatinine fall by <20% versus >20% in the first 24 hours posttransplant, respectively. Non-death censored actual graft survivals are reported herein. RESULTS: Seventy-two of the 335 subjects (21.5%) received organs from ECDs and displayed IGF in 54.7%, SGF 16.2%, and DGF 29.1%. Among SCDs, the SGF and DGF rates were 15.3% and 23.4%, respectively. In ECD, the SGF and DGF rates were 19.4% and 50% (P < .02). Actual graft survivals at 1 and 5 years was 86.3% and 70.4%, respectively. Patients with IGF had higher actual graft survival at 5 years compared to SGF and DGF (83.5% vs 74.1% vs 45.4%). DGF had an equally bad impact on actual 5-year graft survival in SCDs and ECDs (42.6% vs 50%). CONCLUSION: DGF has a strong detrimental impact on 5-year graft survival. There is a higher rate of DGF in ECD versus SCD kidneys. The detrimental impact on 5-year actual graft survival is equal in SCD and ECD kidneys. Minimizing DGF should be our goal.

Recovery of graft function early posttransplant determines long-term graft survival in deceased donor renal transplants.

INTRODUCTION: Because kidneys show remarkable resilience and can recover function, we examined the impact on long-term graft survival in deceased donor renal transplants of both immediate graft function (IGF) and the rate of renal function recovery over the first 3 months after transplantation. METHODS: We included all cadaveric renal transplants from 1990 to 2007 (n = 583). Delayed graft function (DGF) was defined as the need for dialysis in the first 7 days posttransplant. Slow graft function (SGF) and IGF were defined by serum creatinine falls of <20% or >20% in the first 24 hours posttransplant respectively. Recovery of renal function was expressed as either the best creatinine clearance (CrCl) in the first 3 months post-renal transplantation (BCrCl-3mos) as calculated using the Cockcroft-Gault formula or as a percentage of actual versus expected value (as calculated from the donors' CrCl at procurement). RESULTS: There were 140 (23.6%) subjects who received extended criteria donor (ECD) organs. The overall graft survival at 1 and 5 years was 87.8% and 74%, respectively. The 5-year graft survivals for patients with IGF, SGF, and DGF were 85%, 76%, and 54%, respectively (P < .02). ECD kidneys showed twice the DGF rate (49% vs 23%, P < .001). BCrCl-3mos of <30 mL/min displayed a 5-year graft survival of 34%; 30 to 39 mL/min, 72%; 40 to 49 mL/min, 85%; and >50 mL/min, 82% (P < .001). Similarly, a recovery within 90% of expected CrCl in the first 3 months posttransplant correlated with 5-year graft survival of 81%; a recovery of 70% to 90%, with 65%; and a recovery of <70%, with 51% (P < .001). CONCLUSION: Early graft function in the first 3 months showed a significant impact on long-term graft survival after deceased donor renal transplantation.

Proteasome inhibition reduces donor-specific antibody levels.

BACKGROUND: Current antibody-mediated rejection (AMR) therapies (intravenous immunoglobulin, apheresis, rituximab, polyclonal antibodies) do not target the primary antibody producing B cells, that is, the plasma cell. We report the preliminary results from the first clinical experience with plasma cell targeted therapy with bortezomib. Bortezomib is approved by the US Food and Drug Administration for the treatment of plasma cell tumors (multiple myeloma). METHODS: Kidney transplant patients with mixed acute cellular rejection (ACR) and AMR episodes (by Banff '97 criteria, update 2005) were treated with bortezomib (1.3 mg/m(2) per dose x 4) at standard labeled doses. Patients were monitored by serial donor specific anti-HLA antibody (DSA) determinations [Luminex/Labscreen beads] and quantified by conversion to fluorescence intensity to molecules of equivalent soluble fluorescence (MESF). RESULTS: Five patients were treated with bortezomib. Each patient also had coexisting ACR. In each case, bortezomib treatment led to prompt ACR and AMR rejection reversal. DSA levels decreased significantly in all patients (except 1 patient who had short follow-up). Observed toxicities from bortezomib included a transient grade III thrombocytopenia (1 patient) and mild-to-moderate nausea, vomiting, and/or diarrhea (3/5 patients). Opportunistic infections were not observed. CONCLUSIONS: Bortezomib therapy provides effective reduction in DSA levels with long-term suppression. These preliminary results indicate that proteasome inhibition provides an effective means for reducing HLA antibody levels in transplant recipients.

Combining novel technologies with improved logistics to reduce hemodialysis vascular access dysfunction.

Hemodialysis (HD) vascular access dysfunction is currently a huge clinical problem for which there are no effective therapies. There are, however, a number of promising technologies that are currently at the experimental or clinical trial stage. We believe that the application of these novel technologies in combination with better clinical protocols for vascular access care could significantly reduce the current problems associated with HD vascular access.

Variability of the EG95 antigen-coding gene of Echinococcus granulosus in animal and human origin: implications for vaccine development.

In the present study, the genetic variability of the EG95 protein-coding gene in several animal and human isolates of Echinococcus granulosus was investigated. A total of 24 isolates collected from cattle, buffalo, sheep, goat, dog and man were amplified by Eg95-coding gene-specific primers. From the generated sequence information, a conceptual amino acid sequence was deduced. Phylogenetically, the Eg95 coding gene belongs to the Eg95-1/Eg95-2/Eg95-3/Eg95-4 cluster. Further confirmation on the maximum composite likelihood analysis revealed that the overall transition/transversion bias was 2.913. This finding indicated thatthere is bias towards transitional and transversional substitution. Using artificial neural networks, a B-cell epitope was predicted on primary sequence information. Stretches of amino acid residues varied between animal and human isolates when hydrophobicity was considered. Flexibility also varied between larval and adult stages of the organism. This observation is important to develop vaccines. However, cytotoxic T-lymphocyte epitopes on primary sequence data remained constant in all isolates. In this study, agretope identification started with hydrophobic amino acids. Amino acids with the same physico-chemical properties were present in the middle. The conformational propensity of the Eg95-coding gene of 156 amino acid residues had α-turns and ß-turns, and α-amphipathic regions up to 129, 138-156 and 151-155 residues, respectively. The results indicated potential T-cell antigenic sites. The overall Tajima's D value was negative (-2.404165), indicative of negative selection pressure.

Measurement of hemodynamic and anatomic parameters in a swine arteriovenous fistula model.

PURPOSE: Although arteriovenous fistulae (AVFs) are currently the preferred mode of permanent hemodialysis access they do have significant problems due to initial non-maturation and a later venous stenosis. These problems appear to have been exacerbated following a push to increase AVF prevalence in the US. The reasons for both AVF non-maturation and the later venous stenoses are unclear but are thought to be related to abnormal hemodynamic wall shear stress (WSS) profiles. This technical note aims to describe the successful development of measurement techniques that can be used to establish a complete hemodynamic profile in a pig model with two different configurations of AVF. METHODS AND RESULTS: The curved and straight AVF configurations were created in an in vivo pig model. Flow and pressure in the AVFs were measured using the perivascular flow probes and Doppler flow wires while the pressure was recorded using a pressure transducer. The anatomical configuration was obtained using two different approaches: a) combination of intravascular ultrasound (IVUS) and angiograms, (b) 64 slice CT angiography. 3D models were reconstructed using image processing and computer modeling techniques. Numerical calculations were then performed by applying the measured flow and pressure data into the configurations to obtain the hemodynamic WSS profiles. CONCLUSION: The described methodologies will allow the calculation and optimization of WSS profiles in animal models. This information could then be translated to the clinical setting where it would have a positive impact on improving the early maturation rates of AVFs as well as reducing the late venous stenoses.

The Th1/Th2 paradigm and the allograft response.

Although Th1- and Th2-type cytokine profiles have been associated with rejection and tolerance respectively, this paradigm may not be completely accurate. Instead, recent studies suggest that there could be a hierarchy of T-cell growth factors with regard to their ability to block tolerance and induce rejection (rather than a polarized Th1/Th2 demarcation).

The native arteriovenous fistula in 2007. Surveillance and monitoring.

In the past 5 years, some clinical trials have questioned the value of surveillance in managing vascular accesses. Although prolongation of access life span is an important end point, reduction of thrombotic events reduces patient risks resulting from loss of access patency. Most of the available evidence suggests that detection of stenosis and prevention of thrombosis is valuable. When a test indicates the likely presence of a stenosis, then venography or fistulography should be used to definitively establish the presence and degree of the stenosis. In most but not all cases, angioplasty should be performed if the stenosis is greater than 50% by diameter. The value of routine use of any surveillance technique for detecting anatomic stenosis alone, without concomitant functional assessment by measurement of access flow, venous pressure, recirculation or other physiologic parameters, has not been established. Stenotic lesions should not be repaired merely because they are present. If such correction is performed, then intraprocedural or periprocedural measurement of access flow (QA) or intra-access pressure should be conducted to demonstrate a functional improvement with a successful percutaneous transluminal angioplasty.