Neoadjuvant calcium electroporation for potentially curable colorectal cancer.

BACKGROUND: The development of new perioperative treatment modalities to activate the immune system in colorectal cancer might have a beneficial effect on reducing the risk of recurrence after surgery. Calcium electroporation is a promising treatment modality that potentially modulates the tumor microenvironment. The aim of this study was to evaluate the safety of the procedure in the neoadjuvant setting in localized left-sided colorectal cancer (CRC). METHODS: The study included patients with potentially curable sigmoid or rectal cancer with no indication for other neoadjuvant treatment. Patients were offered calcium electroporation as a neoadjuvant treatment before elective surgery. Follow-up visits were conducted on the preoperative day before elective surgery, POD2, POD14, and POD30, with an evaluation of adverse events, impact on elective surgery, clinical examination, and quality of recovery. RESULTS: Endoscopic calcium electroporation was performed as an outpatient procedure in all 21 cases, with no procedure-related complications reported. At follow-up, five adverse events were registered, two of which were classified as serious adverse events. Surgery was performed as planned in 19 patients (median time to surgery, 8 days), and the final two patients underwent surgery with a delay due to adverse events (14 and 33 days). No significant impact on the quality of recovery scores nor inflammatory markers were seen before and after calcium electroporation, nor baseline and POD30. CONCLUSIONS: Endoscopic calcium electroporation is a safe and feasible procedure in patients with potentially curable CRC. The study showed limited side effects and limited impact on the following elective surgical resection.

Short-term results of self-expanding metal stents for acute malignant large bowel obstruction.

AIM: Self-expanding metal stents (SEMSs) can be used as a palliative treatment or to initially decompress colon prior to definitive surgery (as a so-called 'bridge to surgery'). The purpose of this study was to investigate the efficacy and safety of SEMS used as palliation and bridge to surgery for malignant large bowel obstruction. METHOD: A multicentre retrospective study was conducted from January 2010 to December 2013 to identify patients undergoing stent placement for acute large bowel obstruction. Patients were included from four Danish colorectal centres. Outcomes identified included clinical success, 30-day mortality, stent related complications and surgery related complications. Furthermore, we analysed for predictive factors for successful stenting. Clinical success was defined as relief of obstructive symptoms, without the need of other additional surgical interventions during the hospital stay. RESULTS: SEMSs were inserted in 239 patients for whom the indication was as a bridge to surgery in 112 patients (47%) and as palliation in 127 (53%) patients. Clinical success was achieved in 90 patients (80.4%) in the bridge to surgery group and in 105 patients (82.8%) in the palliation group. The 30-day mortality rates in the two groups were 5.4% and 11.8% for bridge to surgery and palliation respectively. A total of 17.8% of the patients in the bridge to surgery group had a stent related complication and in the palliation group it was 20.4%. Multivariate analysis demonstrated that clinical failure is a predictive factor of 30-day mortality (OR 11.1, 95% CI: 4.1-30.0). CONCLUSION: The use of a SEMS to relieve a malignant large bowel obstruction is generally an effective and safe method, but complications are seen in about 20% of patients. Further investigations are required to determine the role of SEMSs in the treatment of acute, malignant, large bowel obstruction.

Possible benefits of robot-assisted rectal cancer surgery regarding urological and sexual dysfunction: a systematic review and meta-analysis.

AIM: Robot-assisted surgery for rectal cancer may result in lower rates of urogenital dysfunction compared with laparoscopic surgery. A systematic review was conducted of studies reporting urogenital dysfunction after robot-assisted rectal cancer surgery. METHOD: PubMed, Embase and the Cochrane Library were systematically searched in February 2014. All studies investigating urogenital function after robot-assisted rectal cancer surgery were identified. The inclusion criteria for meta-analysis studies required comparison of robot-assisted with laparoscopic surgery and the evaluation of urological and sexual function by validated questionnaire. The outcome was evaluated using the International Prostate Symptom Score (IPSS), the International Index of Erectile Function (IIEF) and the Female Sexual Function Index. RESULTS: Ten studies including 689 patients were included. For the meta-analysis this fell to four including 152 patients in the robotic group and 161 in the laparoscopic group, without heterogeneity. The IPSS score at 3 and 12 months favoured robot-assisted surgery [mean difference (MD) -1.58; 95% CI (-3.1, -0.0), [P = 0.04; and MD -0.90 (-1.81, -0.02), P = 0.05]. IIEF scores at 3 months' follow-up [MD -2.59 (-4.25, -0.94),] P = 0.002] and 6 months' follow-up [MD -3.06 (-4.53, -1.59), P = 0.0001] were better after robot-assisted than laparoscopic surgery. CONCLUSION: Although there were few data and no randomized controlled trials the results of the review suggested that robot-assisted surgery resulted in improved urogenital function than after laparoscopy.

Quantification of potassium permanganate consumption and PCE oxidation in subsurface materials.

A series of laboratory scale batch slurry experiments were conducted in order to establish a data set for oxidant demand by sandy and clayey subsurface materials as well as to identify the reaction kinetic rates of permanganate (MnO(4)(-)) consumption and PCE oxidation as a function of the MnO(4)(-) concentration. The laboratory experiments were carried out with 31 sandy and clayey subsurface sediments from 12 Danish sites. The results show that the consumption of MnO(4)(-) by reaction with the sediment, termed the natural oxidant demand (NOD), is the primary reaction with regards to quantification of MnO(4)(-) consumption. Dissolved PCE in concentrations up to 100 mg/l in the sediments investigated is not a significant factor in the total MnO(4)(-) consumption. Consumption of MnO(4)(-) increases with an increasing initial MnO(4)(-) concentration. The sediment type is also important as NOD is (generally) higher in clayey than in sandy sediments for a given MnO(4)(-) concentration. For the different sediment types the typical NOD values are 0.5-2 g MnO(4)(-)/kg dry weight (dw) for glacial meltwater sand, 1-8 g MnO(4)(-)/kg dw for sandy till and 5-20 g MnO(4)(-)/kg dw for clayey till. The long term consumption of MnO(4)(-) and oxidation of PCE can not be described with a single rate constant, as the total MnO(4)(-) reduction is comprised of several different reactions with individual rates. During the initial hours of reaction, first order kinetics can be applied, where the short term first order rate constants for consumption of MnO(4)(-) and oxidation of PCE are 0.05-0.5 h(-1) and 0.5-4.5 h(-1), respectively. The sediment does not act as an instantaneous sink for MnO(4)(-). The consumption of MnO(4)(-) by reaction with the reactive species in the sediment is the result of several parallel reactions, during which the reaction between the contaminant and MnO(4)(-) also takes place. Hence, application of low MnO(4)(-) concentrations can cause partly oxidation of PCE, as the oxidant demand of the sediment does not need to be met fully before PCE is oxidised.

Role of diffusion in chemical oxidation of PCE in a dual permeability system.

The effect of in situ chemical oxidation (ISCO) with permanganate (MnO4-) on tetrachloroethene (PCE) in a dual permeability system consisting of low permeability clay with high permeability sand lenses was investigated by two-dimensional laboratory experiments. The experiments imitate a field remediation at a former dry cleaning facility in Denmark. Results from laboratory experiments and field observations both show that after an application of MnO4- in the sand layer, the diffusion rate into the matrix is decreased due to reaction with PCE and the natural oxidant demand (NOD) related to the clayey till. A narrow but very efficient reaction zone is created in the clayey till. Initiallythe zone developed rapidlyfollowed by a slower expansion with time. PCE will counter diffuse into the reaction zone, where it will be degraded as long as MnO4- is present. A mass balance for the laboratory experiment revealed that the reaction between MnO4- and the clayey till was responsible for up to 90% of the total MnO4- consumption. Based on laboratory experiments, the high MnO4- consumption from reaction with clayey till appears to have been the limiting factor for the oxidation of PCE at the field site and is thus impairing the efficiency of ISCO as a remedy.

Sorption and degradation of the herbicide 2-methyl-4,6-dinitrophenol under aerobic conditions in a sandy aquifer in Vejen, Denmark.

A pulse (7 days) and a continuous (216 days), natural gradient field injection experiment with herbicides, including 2-methyl-4,6-dinitrophenol (4,6-dinitro-o-cresol, abbreviated DNOC), and a bromide tracer were conducted in a shallow, aerobic aquifer near Vejen, Denmark. The pulse and continuous plume were monitored in a dense, three-dimensional monitoring network installed in the aquifer downgradient of the injection. The sorption and degradation of DNOC were evaluated based on moment analysis of breakthrough curves, cross sections, and snapshots of the DNOC plume and supported by results from laboratory experiments. Significant and spatially variable sorption of DNOC (Kd range, 0.10-0.98 L/kg) was observed due to a specific binding of DNOC to clay minerals. The spatial variation was mainly a result of variation in pH, with stronger sorption at lower pH, whereas other factors such as cation composition on the solid matrix appeared to be negligible. Significant degradation of DNOC in the aquifer was revealed by moment analysis of data from the continuous field injection experiment. Degradation of DNOC in the field was slow and/or subject to long lag phases, and the data suggested spatially varying degradation potentials. This was supported by the laboratory experiments. The potential for natural attenuation of DNOC in aerobic aquifers appears promising.