A colonoscopic overtube system that creates a 'therapeutic zone' and permits retraction facilitates endoscopic submucosal dissection, was associated with fewer deep bowel wall injuries and instrument exchanges, and required less lifting solution vs classic endoscopic submucosal dissection in an ex vivo bovine model.

INTRODUCTION: Endoscopic submucosal dissection (ESD) is the 'gold standard' for large flat polyps; nevertheless, the rate of adoption in the USA is low. In ESD, the polyp is 'surgically' detached with a needle knife after a submucosal lift; gravity and the dissection cap are used for retraction. ESD would be easier if active retraction were possible. In an ex vivo bovine colon model, this study assessed an overtube system (Boston Scientific ORISE Tissue Retraction System, TRS) that permits retraction and creates 'an operative field' for removal of rectal/sigmoid lesions. METHOD: Classic ESD (C-ESD) was compared to TRS-facilitated ESD (TRS-ESD). Cleaned/preserved bovine large bowel was used, and two 2-cm 'lesions'/colon were branded onto the mucosal surface 25 and 35 cm from the anus. Submucosal saline lifts were made using a thin catheter and a standard needle knife. We tracked case length, number of instrument exchanges (to refresh lift), the volume of lift solution, the fullness of resection, and deep muscle injuries. RESULTS: Fifty ESDs were carried out in 25 colons (25 C-ESD, 25 TRS-ESD). Complete resections were noted in all cases. The TRS method required fewer instrument exchanges (median 5) vs C-ESD (median 9, p < 0.0001) and less lift solution (median 39 ml) than the C-ESD cases (median 55 ml, p = 0.0003). TRS-ESD was associated with fewer deep muscle injuries (median 2) than C-ESD (median 3, p = 0.0191). Finally, the TRS group's median case length (34.5 min) was shorter than that of C-ESD (41 min, p = 0.0543). CONCLUSION: The TRS system provides retraction and facilitates ESD regarding the number of lift injections, the volume of lift solution needed, and avoidance of muscle injuries. Of note, there is an apparent TRS learning curve, and the device mandates a distal-to-proximal approach and initial 360 degree mucosal incision. Further study is warranted.

Pressurized Intraperitoneal Aerosol Chemotherapy, a Palliative Treatment Approach for Patients With Peritoneal Carcinomatosis: Description of Method and Systematic Review of Literature.

BACKGROUND: Peritoneal metastases arise in patients with a variety of primary cancers, and are associated with a poor prognosis. Systemic chemotherapy is the mainstay of treatment; however, the morbidity is considerable and the survival benefit is modest. Cytoreductive surgery and heated intraperitoneal chemotherapy is a potentially curative treatment available to a minority of patients; however, most develop recurrent disease. A novel palliative treatment for peritoneal metastases, pressurized intraperitoneal aerosol chemotherapy, has recently been introduced. Pressurized intraperitoneal aerosol chemotherapy utilizes an aerosol of chemotherapy in carbon dioxide gas. It is instilled into the abdomen under pressure via laparoscopic ports. No cytoreduction is performed. Pressurized intraperitoneal aerosol chemotherapy can be repeated at 6-week intervals. Oxaliplatin or cis-platinum and doxorubicin have been used to date. OBJECTIVE: This study aims to systematically review and evaluate the method, and the preclinical and early clinical results of pressurized intraperitoneal aerosol chemotherapy. DATA SOURCES: Medline and the Cochrane Library were the data sources for the study. STUDY SELECTION: Peer-reviewed series of greater than 10 patients, with sufficient patient data, through April 2019, were selected. INTERVENTION: Patients with peritoneal metastases underwent pressurized intraperitoneal aerosol chemotherapy. MAIN OUTCOME MEASURES: Patient dropout, histologic tumor response, adverse events, and 30-day mortality were the primary outcomes measured. RESULTS: A total of 921 patients with peritoneal metastases were brought to the operating room for pressurized intraperitoneal aerosol chemotherapy. The number of pressurized intraperitoneal aerosol chemotherapy treatments administered was as follows: 1 treatment, 862 (94%); 2 treatments, 645 (70%); and 3 treatments, 390 patients (42%). Initial laparoscopic access was not possible in 59 patients (6.4%). Common Terminology Criteria for Adverse Events grade 3 or higher were noted in 13.7% of the patients who, collectively, underwent a total of 2116 treatments. The 30-day mortality was 2.4% (22/921). LIMITATIONS: This study was limited by the heterogeneity of reported data and primary tumor types and by the lack of long-term survival data. CONCLUSIONS: Early clinical results are encouraging, but tumor-specific, prospective, randomized trials are needed to compare pressurized intraperitoneal aerosol chemotherapy to systemic chemotherapy. This method has yet to be introduced to the United States. It is another therapeutic option for patients with peritoneal metastases and will broaden the patient base for future clinical trials.

Warm and Humidified Versus Cold and Dry CO2 Pneumoperitoneum in Minimally Invasive Colon Resection: A Randomized Controlled Trial.

INTRODUCTION: Peritoneal insufflation with warm-humidified (WH) CO2 gas during minimally invasive surgical procedures is purported to prevent hypothermia and peritoneal desiccation and is associated with decreased postoperative IL-6 levels. This randomized study's purpose was to determine the clinical impact of WH versus cold-dry (CD) CO2 in minimally invasive colon resection (MICR), and to assess perioperative plasma levels of IL-6, TIMP-1, sVEGF-R1, and HSP-70 after MICR. METHODS: Operative and short-term clinical data plus perioperative blood samples were collected on MICR patients randomized to receive either WH (36.7°C, 95% humidity) or CD (room temperature, 0% humidity) CO2 perioperatively. Peritoneal biopsies were taken at the start and end of surgery. Outcomes tracked included core temperature, postoperative in-hospital pain levels, analgesia requirements, and standard recovery parameters. Preoperative and postoperative days (PODs) 1 and 3 plasma protein levels were determined via ELISA. RESULTS: A total of 101 patients were randomized to WH CO2 (50) or CD CO2 (51). The WH group contained more diabetics ( P = .03). There were no differences in indication, minimally invasive surgical method used, or core temperature. Pain scores were similar; however, the WH patients required less narcotics on PODs 1 to 3 ( P < .05), and less ketorolac on PODs 1 and 2 ( P < .03). No differences in length of stay, complication rates, or time to flatus/diet tolerance were noted. Plasma levels of the 4 proteins were similar postoperatively. Though insignificant, the WH group had less marked histologic changes on "end-of-case" peritoneal biopsies. CONCLUSION: This study found significantly lower pain medication requirements for PODs 1 to 3 for the WH group; however, because there were no differences in the pains scores between the groups, firm conclusions regarding WH CO2 cannot be made.

Immune evasion in cancer: Mechanistic basis and therapeutic strategies.

Cancer immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Although considerable progress has been made in understanding how cancers evade destructive immunity, measures to counteract tumor escape have not kept pace. There are a number of factors that contribute to tumor persistence despite having a normal host immune system. Immune editing is one of the key aspects why tumors evade surveillance causing the tumors to lie dormant in patients for years through "equilibrium" and "senescence" before re-emerging. In addition, tumors exploit several immunological processes such as targeting the regulatory T cell function or their secretions, antigen presentation, modifying the production of immune suppressive mediators, tolerance and immune deviation. Besides these, tumor heterogeneity and metastasis also play a critical role in tumor growth. A number of potential targets like promoting Th1, NK cell, γδ T cell responses, inhibiting Treg functionality, induction of IL-12, use of drugs including phytochemicals have been designed to counter tumor progression with much success. Some natural agents and phytochemicals merit further study. For example, use of certain key polysaccharide components from mushrooms and plants have shown to possess therapeutic impact on tumor-imposed genetic instability, anti-growth signaling, replicative immortality, dysregulated metabolism etc. In this review, we will discuss the advances made toward understanding the basis of cancer immune evasion and summarize the efficacy of various therapeutic measures and targets that have been developed or are being investigated to enhance tumor rejection.

Efficacy of laparoscopic-assisted approach for reversal of Hartmann's procedure: results from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

INTRODUCTION: Morbidity after reversal of Hartmann's procedure remains high. The laparoscopic approach (LAP) may be associated with lower morbidity versus open Hartmann's closure. This study's aim is to compare results after LAP and OPEN colostomy takedown and Hartmann's reversal. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2005 to 2012 for CPT procedure codes 44227 (LAP) and 44626 (OPEN). Exclusion criteria included: ventilator dependence, ASA class 4 or 5, SIRS, sepsis, emergency case, and advanced malignancy. Demographic parameters were assessed as well as comorbidities and short-term outcomes. Statistical methods used include Fisher's exact test for categorical variables and Student's t test for continuous variables. RESULTS: In total, 4,148 patients underwent stoma closure and Hartmann's reversal (LAP 732 [17.6 %], OPEN 3,416 [82.3 %]). The mean BMI was lower in the LAP (mean ± SD 27.6 ± 6.6) versus OPEN group (28.3 ± 6.8, p = 0.012). The groups were similar as regards comorbidities except for dyspnea (LAP 5.6 %, OPEN 7.8 %, p = 0.043). The mean surgery times were similar and the median LOS shorter in the LAP versus OPEN groups (5 vs 6 days, p < 0.0001). A lower overall morbidity rate was noted for the LAP group (18.4 % vs OPEN 27 %, p < 0.0001) but mortality was statistically similar. Lower rates were noted in the LAP group for the following complications: incisional SSI (10.4 vs 14.1 %, p = 0.033), organ space SSI (3.1 vs 5.0 %, p = 0.033), UTI (1.6 vs 3.3 %, p = 0.005), sepsis (3.4 vs 6.0 %, p = 0.038), and reoperation (3.1 vs 5.4 %, p = 0.011). CONCLUSION: Only 18 % of Hartmann's reversal's were done using LAP methods. The LAP and OPEN groups were similar except for gender, BMI, and dyspnea history. LAP methods were associated with a 1 day LOS benefit and significantly lower overall morbidity and lower rates of incisional and deep SSI, UTI, sepsis, and reoperations. Operative length was similar. The short-term results of the LAP approach are superior to the OPEN results.

Sustained postoperative plasma elevations of plasminogen activator inhibitor-1 following minimally invasive colorectal cancer resection.

Plasminogen activator inhibitor-1 (PAI-1) is a serine protease inhibitor that inhibits urokinase-type plasminogen activator and tissue-type plasminogen activator. PAI-1 participates in angiogenesis, wound healing and tumor invasion, and additionally regulates endothelial cell proliferation, angiogenesis and tumor growth. The purpose of the present study was to measure plasma PAI-1 levels perioperatively in patients with colorectal cancer (CRC) undergoing minimally invasive colorectal resection (MICR). Patients with CRC who underwent elective MICR were eligible for the study. All patients were enrolled in an approved data/plasma bank. Patients with preoperative, postoperative day (POD) 1, POD 3, and at least one POD 7-34 plasma sample collection were studied. Plasma PAI-1 levels were determined in duplicate using ELISA, and the medians and 95% confidence intervals (CIs) were determined. The correlations between postoperative plasma PAI-1 levels and length of surgery were evaluated. PAI-1 levels were compared between patients who underwent laparoscopic-assisted vs. hand-assisted surgery. The preoperative PAI-1 levels of stage I, II, III and IV pathological stage subgroups were also compared. A total of 91 patients undergoing MICR for CRC were studied. The mean incision length was 8.0±3.9 cm, and the length of stay was 6.8±4.3 days. Compared with the median preoperative levels (17.30; 95% CI: 15.63-19.78 ng/ml), significantly elevated median levels were observed on POD 1 (28.86; 95% CI: 25.46-31.22 ng/ml; P<0.001), POD 3 (18.87; 95% CI: 17.05-21.78 ng/ml; P=0.0037), POD 7-13 (26.97; 95% CI: 22.81-28.74 ng/ml; P<0.001), POD 14-20 (25.92; 95% CI: 17.85-35.89 ng/ml; P=0.001) and POD 21-27 (22.63; 95% CI: 20.03-30.09 ng/ml; P<0.001). The PAI-1 levels in the hand-assisted group were higher compared with those in the laparoscopic-assisted group for 4 weeks after surgery; however, a significant difference was found only on POD 1. Therefore, plasma PIA-1 levels were found to be significantly elevated for 4 weeks after MICR, and the surgery-related acute inflammatory response may account for the early postoperative PIA-1 increase. Furthermore, PAI-1-associated VEGF-induced angiogenesis in the healing wounds may account for the late postoperative elevations, and increased PAI-1 levels may promote angiogenesis in residual tumor deposits.

The cancer testis antigens CABYR-a/b and CABYR-c are expressed in a subset of colorectal cancers and hold promise as targets for specific immunotherapy.

INTRODUCTION: Calcium-binding tyrosine phosphorylation-regulated protein (CABYR) is expressed in the human germ line but not in adult human tissues, thus, it is considered a cancer testis protein. The aim of this study is to evaluate the CABYR isoforms: a/b and c mRNA expression in colorectal cancer (CRC) and to determine if these proteins hold promise as vaccine targets. MATERIALS AND METHODS: CABYR mRNA expression in a set of normal human tissues, including the testis, were determined and compared using semi-quantitative PCR. As regards the tumor and normal mucosal samples from study patients, RNA was extracted and cDNA generated after which quantitative PCR was carried out. Analysis of CABYR protein expressions by immunohistochemistry in tumor and normal colon tissues was also performed. RESULTS: A total of 47 paired CRC and normal tissue specimens were studied. The percent of patients with a relative expression ratio of malignant to normal (M/N) tissues over 1 was 70% for CABYR a/b and 72% for CABYR c. The percent with both a M/N ratio over 1 and expression levels over 0.1% of testis was 23.4% for CABYR-a/b and 25.5% for CABYR c. CABYR expression in tumors was further confirmed by immunohistochemistry. CONCLUSIONS: CABYR a/b and c hold promise as specific immunotherapy targets, however, a larger and more diverse group of tumors (Stage 1-4) needs to be assessed and evaluation of blood for anti-CABYR antibodies is needed to pursue this concept.

Splenic flexure mobilization for sigmoid and low anterior resections in the minimally invasive era: How often and at what cost?

BACKGROUND: Splenic flexure mobilization (SFM) increases left colonic reach for a better vascularized and tension-free anastomosis. Open SFM is challenging due to anatomic position. Minimally invasive SFM improves visualization and minimizes splenic traction. METHODS: We retrospectively reviewed all sigmoid and low anterior resections (LAR) by a colorectal surgical group over 10-year period. We analyzed indications, surgical methods and perioperative outcomes of open and MIS SFM cohorts. RESULTS: 793 patients were included; 122 (15.5%) open, 671 (84.5%) MIS (60% laparoscopic-assisted (LA), 40% hand-assisted (HA)). Overall, indications were cancer (56%), diverticulitis (31%), and other benign diseases (13%). Compared to MIS, open cases had more complex disease (45% vs. 18%, p < 0.01), with fewer SFM performed (40% vs. 86%, p < 0.01), required more frequent diversion (30% vs. 21%, p = 0.02) and were complicated by higher leak/abscess (7% vs. 3%, p = 0.06) and reoperation rates (10% vs. 6%, p = 0.11). 1% of SFM required conversion (LA to HA 0.5%, MIS to open 0.5%). There were no open SFM complications. There were 26 (5%) MIS SFM complications; bleeding (18; 12 splenic capsular tears (0 splenectomy/splenorraphy), 6 mesenteric) and organ injury (bowel (3), pancreatic (4), renal (1)). CONCLUSIONS: Our SFM rate was high in the MIS group, with a low overall complication rate. Of note, the anastomotic leak/abscess rate was 3%, and may be related to the high SFM rate. It is the authors' opinion that a major advantage of MIS is to facilitate SFM, hence SFM is more likely to be performed with these methods compared to open procedures.

Colorectal resection is associated with persistent proangiogenic plasma protein changes: postoperative plasma stimulates in vitro endothelial cell growth, migration, and invasion.

INTRODUCTION: Plasma vascular endothelial growth factor (VEGF) levels are elevated for weeks after minimally invasive colorectal resection (MICR). Decreased plasma angiopoietin-(Ang) 1 and increased Ang-2 levels have been noted on postoperative days (POD) 1 and 3. These proangiogenic changes may stimulate tumor growth postoperatively (postop). This study's purpose was to track plasma VEGF, Ang-1, and Ang-2 levels for 4 to 8 weeks after MICR for cancer and to assess the impact of preoperative (preop) and postop plasma on in vitro endothelial cell (EC) behavior. METHODS: Blood samples from 105 MICR patients were taken preop, on POD 5 and at varying time points for 2 months. Samples from 7 day time blocks after POD 5 were bundled to permit statistical analysis. Plasma protein levels were measured via enzyme-linked immunosorbent assay. In vitro EC branch point formation, EC invasion, and EC migration assays were carried out with preop, POD 7 to 13 and 14 to 20 plasma. The t test and Bonferonni correction was used. RESULTS: VEGF levels were significantly elevated on POD 5 and 7 to 13; lesser increases were noted on POD 14 to 20 and 21 to 27. Ang-2 levels were significantly increased at all time points postop. No significant Ang-1 changes were noted. When compared to preop EC culture results, there was significantly more EC branch point formation, EC invasion, and EC migration assays noted with POD 7 to 13 and POD 14 to 20 plasma. CONCLUSIONS: MICR is associated with proangiogenic plasma changes for 2 to 4 weeks and plasma from POD 7 to 13 and 14 to 20 stimulated EC growth, invasion, and migration. Postop plasma may stimulate the growth of residual tumor.

P-Cadherin (CDH3) is overexpressed in colorectal tumors and has potential as a serum marker for colorectal cancer monitoring.

INTRODUCTION: Placental-Cadherin (CDH3) is a cell adhesion molecule vital to cellular localization and tissue integrity. It is highly expressed in the placenta (PLC)and is overexpressed by many types of cancer. P-cadherin levels in colorectal cancer (CRC) remains poorly characterized. This study's purpose was to determine P-cadherin expression in CRC and normal tissues and to assess plasma CDH3 levels in order to determine the relationship, if any, between cancer stage, P-cadherin expression and plasma CDH3 levels. METHODS: An IRB approved plasma, tumor, and prospective data bank was utilized. CRC patients for whom tumor and normal colon tissue samples were available were enrolled. Tumor samples were OCT embedded and stored at -80C°. Total purified RNA was isolated from tissue samples and cDNA synthesized. CDH3 expression was analyzed by quantitative PCR (QPCR) using the SYBR Green platform. Tumor expression levels were determined and compared to levels in normal colonic tissue and PLC. Expression in 22 different normal tissues was also assessed by RT-PCR. Plasma CDH3 levels were determined via ELISA in patients for whom preoperative blood samples were available. Results: A total of 77 paired CRC and normal colon specimens (36 M/ 41 F, age 67.3±14.5) were assessed (82% colon, 18% rectal; Cancer Stage 2, 44; Stage 3, 33). All tested tumors had CDH3 expression levels over 0.1% of the PLC level and tumor to normal colon ratios greater than 1. CDH3 expression was noted in 14/22 normal organ tissues. There was a positive correlation between tumor CDH3 QPCR and preoperative CDH3 blood levels (n=57, P= 0.038). Expression levels were significantly higher in rectal vs. colon tumors (p=0.019). Conclusion: CDH3 expression was elevated in CRC tumors as compared to normal tissue. CDH3 was expressed by numerous normal organs and, thus, is not a viable vaccine target, however, the correlation between plasma and tumor CDH3 levels suggests CDH3 may have value as a diagnostic or prognostic marker.

Involvement of a transformylase enzyme in siderophore synthesis in Pseudomonas aeruginosa.

Fluorescent pseudomonads produce yellow-green siderophores when grown under conditions of iron starvation. Here, the characterization of the pvdF gene, which is required for synthesis of the siderophore pyoverdine by Pseudomonas aeruginosa strain PAO1, is described. A P. aeruginosa pvdF mutant was constructed and found to be defective for production of pyoverdine, demonstrating the involvement of PvdF in pyoverdine synthesis. Transcription analysis showed that expression of pvdF was regulated by the amount of iron in the growth medium, consistent with its role in siderophore production. DNA sequencing showed that pvdF gives rise to a protein of 31 kDa that has similarity with glycinamide ribonucleotide transformylase (GART) enzymes involved in purine synthesis from a wide range of eukaryotic and prokaryotic species. Chemical analyses of extracts from wild-type and pvdF mutant bacteria indicated that the PvdF enzyme catalyses the formylation of N(5)-hydroxyornithine to give rise to N(5)-formyl-N(5)-hydroxyornithine, a component of pyoverdine. These studies enhance understanding of the enzymology of pyoverdine synthesis, and to the best of the authors' knowledge provide the first example of involvement of a GART-type enzyme in synthesis of a secondary metabolite.