Reactivation of the homeotic tumor suppressor gene CDX2 by 5-aza-2'-deoxycytidine-induced demethylation inhibits cell proliferation and induces caspase-independent apoptosis in gastric cancer cells

The DNA methylation inhibitor 5-aza-2′-deoxycytidine (5-aza-CdR) is widely used as an anticancer drug for the treatment of leukemia and solid tumors. Gastric cancer (GC) patients who were positive for caudal type homeobox transcription factor 2 (CDX2) expression showed a higher survival rate compared with those who were CDX2 negative, which suggests that CDX2 performs a tumor suppressor role. However, the molecular mechanisms leading to the inactivation of CDX2 remain unclear. In the present study we demonstrated that the expression levels of CDX2 and DNA methyltransferase enzyme 1 (DNMT1) mRNA were significantly higher in GC compared with distal non-cancerous tissue. The expression of CDX2 mRNA was significantly correlated with Lauren classification, TNM stage and lymph node metastasis. DNMT1 mRNA expression was significantly correlated with TNM stage, pathological differentiation and lymph node metastasis. The expression of CDX2 mRNA was inversely correlated with that of DNMT1 mRNA in GC. Hypermethylation of the CDX2 gene promoter region, extremely low expression levels of CDX2 mRNA and no expression of CDX2 protein were the characteristics observed in MKN-45 and SGC-7901 GC cell lines. Following the treatment of MKN-45 cells with 5-aza-CdR, the hypermethylated CDX2 gene promoter region was demethylated and expression of CDX2 was upregulated, while DNMT1 expression was downregulated. Furthermore, a concentration- and time-dependent growth inhibition as well as increased apoptosis were observed. Caspase-3, −8 and −9 activities increased in a concentration-dependent manner following exposure to different concentrations of 5-aza-CdR. Therefore, our data show that the overexpression of DNMT1 and methylation of the CDX2 gene promoter region is likely to be responsible for CDX2 silencing in GC. 5-Aza-CdR may effectively induce re-expression of the CDX2 gene, inhibit cell proliferation and enhance the caspase-independent apoptosis of MKN-45 cells in vitro.

Mechatronic design of a fully integrated camera for mini-invasive surgery

This paper describes the design features of an innovative fully integrated camera candidate for mini-invasive abdominal surgery with single port or transluminal access. The apparatus includes a CMOS imaging sensor, a light-emitting diode (LED)-based unit for scene illumination, a photodiode for luminance detection, an optical system designed according to the mechanical compensation paradigm, an actuation unit for enabling autofocus and optical zoom, and a control logics based on microcontroller. The bulk of the apparatus is characterized by a tubular shape with a diameter of 10 mm and a length of 35 mm. The optical system, composed of four lens groups, of which two are mobile, has a total length of 13.46 mm and an effective focal length ranging from 1.61 to 4.44 mm with a zoom factor of 2.75×, with a corresponding angular field of view ranging from 16° to 40°. The mechatronics unit, devoted to move the zoom and the focus lens groups, is implemented adopting miniature piezoelectric motors. The control logics implements a closed-loop mechanism, between the LEDs and photodiode, to attain automatic control light. Bottlenecks of the design and some potential issues of the realization are discussed. A potential clinical scenario is introduced.

Surgical management of cystic lesions in the liver

BACKGROUND

Liver cysts are common, occurring in up to 5% of the population. For many types of cysts, a variety of different treatment options exist and the preferred management is unclear.

METHODS

A PubMed and Medline literature review was undertaken and articles pertaining to the diagnosis and management of cystic lesions within the liver were retrieved.

RESULTS

Therapy for symptomatic cysts may incorporate aspiration with sclerotherapy or de-roofing. Polycystic liver disease presents a unique management problem because of the high morbidity and mortality rates from intervention and high rates of recurrence. Careful patient counselling and assessment of symptom index is essential before embarking on any treatment. New medical treatments may ameliorate symptoms. Acquired cystic lesions in the liver require a thorough work-up to fully characterize the abnormality and direct appropriate treatment. Hydatid cysts are best treated by chemotherapy, followed by some form of surgical intervention (either aspiration and sclerotherapy or surgery). Liver abscesses can be effectively treated by aspiration or drainage.

CONCLUSION

All patients with cystic lesions in the liver require discussion at multidisciplinary meetings to confirm the diagnosis and determine the most appropriate method of treatment.

Oral chlorhexidine and microbial contamination during endoscopy: possible implications for transgastric surgery. A randomized, clinical trial

BACKGROUND

One of the biggest concerns associated with transgastric surgery is contamination and risk of intra-abdominal infection with microbes introduced from the access route. The purpose of this study was to evaluate the effect of oral decontamination with chlorhexidine on microbial contamination of the endoscope.

METHODS

In a prospective, randomized, single-blinded, clinical trial the effect of chlorhexidine mouth rinse was evaluated. As a surrogate for the risk of intra-abdominal contamination during transgastric surgery, microbial contamination of the endoscope during upper endoscopy was examined. Patients referred to upper endoscopy were assessed for eligibility and randomized to either chlorhexidine or no mouth rinse. Culture samples were collected from gastric aspirates and endoscopes. The primary outcome measure was colony forming units (CFU) in the endoscope samples. Secondary outcome measures were species specific effect of chlorhexidine on micro-organisms with abscess forming capabilities and the effect of proton pump inhibitor (PPI) treatment on CFU.

RESULTS

Chlorhexidine mouth rinse resulted in a significant reduction of CFU in the endoscope samples (p = 0.001). There was no species specific effect and micro-organisms with abscess forming capabilities were equally present. PPI treatment was associated with significantly higher CFU counts in both the gastric (p = 0.004) and endoscope samples (p = 0.049).

CONCLUSIONS

Chlorhexidine mouth rinse was effective in reducing microbial contamination of the endoscope, but micro-organisms with abscess forming capabilities were still present. PPI treatment significantly increased CFU and should be discontinued before transgastric surgery.

Differentiation of stem cells into insulin-producing cells: current status and challenges

Diabetes mellitus is one of the most serious public health challenges of the twenty-first century. Allogenic islet transplantation is an efficient therapy for type 1 diabetes. However, immune rejection, side effects of immunosuppressive treatment as well as lack of sufficient donor organs limits its potential. In recent years, several promising approaches for generation of new pancreatic β cells have been developed. This review provides an overview of current status of pancreatic and extra-pancreatic stem cells differentiation into insulin-producing cells and the possible application of these cells for diabetes treatment. The PubMed database was searched for English language articles published between 2001 and 2012, using the keyword combinations: diabetes mellitus, differentiation, insulin-producing cells, stem cells.

A modular magnetic platform for Natural Orifice Transluminal Endoscopic Surgery

Modern surgery is currently developing NOTES (Natural Orifice Translumenal Endoscopic Surgery) robotic approaches to enable scarless surgical procedures. Despite of the variegated devices proposed, they still have several limitations. In this work, we propose a surgical platform composed of specialized modules, in order to provide the overall system with adequate stability, dexterity and force generation. The concept behind the platform, the main modules and their performance are described to highlight the system potential to outperform current NOTES procedures.

Meeting report of the International Liver Transplantation Society's 18th annual international congress: Hilton San Francisco Hotel, San Francisco, CA, May 16-19, 2012

From May 16-19, 2012, the International Liver Transplantation Society held its annual congress in San Francisco, CA. More than 1300 registrants attended the meeting, which included a premeeting conference entitled Balancing Risk in Liver Transplantation, focused topic sessions, and a variety of oral and poster presentations. This report is not all-inclusive and focuses on specific research abstracts on key topics in liver transplantation. As always, the new data herein are presented in the context of the published literature to further enhance knowledge in the field.

Frank intrabiliary rupture in liver hydatidosis located in the hilar plate: a surgical challenge

BACKGROUND

Frank intrabiliary rupture (FIR) is a severe complication that occurs in around 30% of patients with liver hydatidosis. When FIR is present, the contents of the cyst may pass into the common bile duct and cause a variety of complications. If the FIR is located in the hilar confluence, surgical repair is a challenge. Currently there are no data regarding its optimum treatment.

MATERIAL AND METHODS

Between May 2007 and December 2012, we treated 59 patients with liver hydatidosis. Four patients, all women, with a mean age of 51.7 years, had hydatid cysts located between segments IVb and V and FIR affecting the hilar plate. In 3 cases, the initial clinical condition was obstructive jaundice. The fourth patient presented recurrence after having undergone two operations as a child.

RESULTS

In each patient a major hepatectomy was performed with hilar plate reconstruction (3 left and 1 right). Morbidity included mild biliary fistula (1 patient) and abdominal collection resolved by percutaneous drainage (1 patient). There was no mortality. During follow-up (47 months), no recurrences of the disease or biliary strictures were recorded.

CONCLUSIONS

FIR is a severe complication of liver hydatidosis. When it is located in the hilar confluence, liver resection may be the best surgical option for definitive resolution of the problem.

Adopting Gayet's Techniques of Totally Laparoscopic Liver Surgery in the United States

Professor Brice Gayet of the Institut Mutualiste Montsouris in Paris, France, has developed totally laparoscopic techniques for all segments of the liver. As a pioneer in the field of minimally invasive hepato-pancreato-biliary surgery, he started a Minimally Invasive Hepato-Pancreato-Biliary Fellowship in 2006. A retrospective review of all hepatic cases performed by a single surgeon since completing this Fellowship was undertaken. From November 2007 to October 2012, a total of 80 liver resections were done, of which 73 were begun with the intention of completing the case laparoscopically. Of these, more than 90% were completed laparoscopically and 88% were for malignant disease. One of the foundations of Professor Gayet's techniques is the low lithotomy or 'French' position and the utilization of a small robotically controlled laparoscope holder that is sterilizeable and considerably more economic than complete surgical systems. Prototypes exist of robotically controlled hand-held laparoscopic instruments that, unlike the complete surgical system, enable surgeons to maintain a sense of touch (haptics). Proper training in minimally invasive hepato-pancreato-biliary techniques can be obtained with surgeons able to independently perform laparoscopic major hepatectomies without senior minimally invasive backup. Furthermore, miniature and more affordable robotics may enable more surgeons to enjoy the benefits of minimally invasive surgery while maintaining patient safety and minimizing the rising burden of health-care costs worldwide.

CIHR Canadian HIV Trials Network Coinfection and Concurrent Diseases Core: Canadian guidelines for management and treatment of HIV/hepatitis C coinfection in adults

BACKGROUND

Hepatitis C virus (HCV) coinfection occurs in 20% to 30% of Canadians living with HIV, and is responsible for a heavy burden of morbidity and mortality. HIV-HCV management is more complex due to the accelerated progression of liver disease, the timing and nature of antiretroviral and HCV therapy, mental health and addictions management, socioeconomic obstacles and drug-drug interactions between new HCV direct-acting antiviral therapies and antiretroviral regimens.

OBJECTIVE

To develop national standards for the management of HCV-HIV coinfected adults in the Canadian context.

METHODS

A panel with specific clinical expertise in HIV-HCV co-infection was convened by The CIHR HIV Trials Network to review current literature, existing guidelines and protocols. Following broad solicitation for input, consensus recommendations were approved by the working group, and were characterized using a Class (benefit verses harm) and Level (strength of certainty) quality-of-evidence scale.

RESULTS

All HIV-HCV coinfected individuals should be assessed for HCV therapy. Individuals unable to initiate HCV therapy should initiate antiretroviral therapy to slow liver disease progression. Standard of care for genotype 1 is pegylated interferon and weight-based ribavirin dosing plus an HCV protease inhibitor; traditional dual therapy for 24 weeks (for genotype 2/3 with virological clearance at week 4); or 48 weeks (for genotypes 2-6). Therapy deferral for individuals with mild liver disease may be considered. HIV should not be considered a barrier to liver transplantation in coinfected patients.

DISCUSSION

Recommendations may not supersede individual clinical judgement.

Clinical and prognostic features of rectal neuroendocrine tumors

BACKGROUND

Rectal neuroendocrine tumors (NETs) are among the most common NETs. The aim was to validate European Neuroendocrine Tumor Society (ENETS)/North American Neuroendocrine Tumor Society (NANETS) staging and grading systems with regard to clinical outcomes.

METHODS

A comprehensive database was constructed from existing databases of the Mount Sinai Division of Gastrointestinal Pathology and the Carcinoid Cancer Foundation. Analysis was performed on 141 patients identified with rectal NETs seen at Mount Sinai Hospital between 1972 and 2011.

RESULTS

The median age was 52.7 years; 43% were males. Average tumor size was 0.88 cm. NETs <1 cm accounted for 75.6% of the tumors. Stage I, II, III and IV accounted for 79.4, 2.8, 5.0 and 12.8% of the tumors, respectively. G1 tumors accounted for 88.1%, G2 8.3% and G3 3.6%. Of G1 tumors, 94.6% were stage I and 5.4% were stage IV. The median survival time for all 141 patients was 6.8 years (range, 0.8-34.7 years). The overall 5-year survival rate was 84.4%. The 5-year survival rates for patients in stages I-IV were 92.7, 75.0, 42.9 and 33.2%, respectively. The 5-year survival rates for patients with G1-G3 tumors were 87.7, 47.6 and 33.3%, respectively. Univariate analysis of increased survival showed significance for lower stage, lower grade, smaller size, absence of symptoms and endoscopically treated tumors. Multivariate analysis showed that stage alone was statistically significant as the strongest predictor of survival.

CONCLUSION

The results of our study validated ENETS/NANETS guidelines for staging and grading of rectal NETs in the US setting of a tertiary referral center. Staging according to ENETS/NANETS guidelines should be used in the treatment algorithm rather than size alone.

Systematic review of the use of topical diltiazem compared with glyceryltrinitrate for the nonoperative management of chronic anal fissure

AIM

The study analyzed clinical trials investigating the effectiveness of diltiazem (DTZ) and glyceryltrinitrate (GTN) for the nonsurgical management of chronic anal fissure (CAF).

METHOD

Randomized trials on the effectiveness of DTZ and GTN were analyzed systematically using RevMan(®) where combined outcome was expressed as risk ratio (RR).

RESULTS

Seven randomized controlled trials that included 481 patients were analyzed. Two-hundred and thirty-eight patients were treated with DTZ and 243 patients were treated with GTN. There was significant heterogeneity [Tau(2) = 0.24, χ2 = 13.16, d.f. = 6 (P < 0.05); I(2) = 54%] among the included trials. In the random-effects model, DTZ was associated with a lower incidence of side effects (RR = 0.48; 95% CI = 0.27, 0.86; z = 2.46; P < 0.01), headache (RR = 0.39; 95% CI = 0.24, 0.66; z = 3.54; P < 0.004) and recurrence (RR = 0.68; 95% CI = 0.52, 0.89; z = 2.77; P < 0.006) of CAF. Both GTN and DTZ were equally effective (RR = 1.10; 95% CI = 0.90, 1.34; z = 0.92; P = 0.36) in the nonsurgical management of CAF.

CONCLUSION

This systematic review of seven trials validates and strengthens the finding of a previously published meta-analysis of two randomized trials. Both DTZ and GTN are equally effective in the management of CAF. However, DTZ is associated with a lower incidence of headache and recurrent fissure. Therefore DTZ should be the preferred first line of treatment for CAF.

Evaluation of electrical activity after vagus nerve-preserving distal gastrectomy using multichannel electrogastrography

BACKGROUND

Multichannel electrogastrography (M-EGG) can be used to evaluate gastrointestinal motility. The myoelectric activity of the remnant stomach after surgery has not been measured by M-EGG. This study examined whether myoelectric activity varied with surgical technique and compared vagus nerve-preserving distal gastrectomy (VP-DG) with standard distal gastrectomy without vagus nerve preservation (DG). Furthermore, we examined the relationship between the M-EGG findings and patients' postoperative symptoms.

METHODS

Twenty-six patients who underwent VP-DG, 20 who underwent DG, and 12 healthy volunteers as controls were examined with M-EGG. The Gastrointestinal Symptom Rating Scale (GSRS) was used to assess postoperative symptoms.

RESULTS

Longer periods of normal gastric function (normogastria, 2.0-4.0 cycle min(-1)) were detected in channel 1 in the VP-DG group than in the DG group in either the fasted or fed state (P<0.05). The percentage of slow wave coupling (%SWC) in the fed state correlated negatively with GSRS scores (reflux, r=-0.59, P=0.02; abdominal pain, r=-0.51, P=0.04, indigestion, r=-0.59, P=0.02 and total score, r=-0.75, P=0.02).

CONCLUSIONS

Slow waves can be recorded non-invasively using M-EGG in the remnant stomach following gastrectomy. The VP-DG group showed better preserved gastric myoelectric activity than the DG group, and the %SWC showed a significant negative correlation with scores of GSRS (reflux, abdominal pain, indigestion and total score) in the VP-DG group.

Tumor-infiltrating immune cells: triggers for tumor capsule disruption and tumor progression?

BACKGROUND

Our previous studies of human breast and prostate cancer have shown that aberrant immune cell infiltration is associated with focal tumor capsule disruption and tumor cell budding that facilitate invasion and metastasis. Our current study attempted to determine whether aberrant immune cell infiltration would have similar impact on colorectal cancer (CRC).

MATERIALS AND METHODS

Tissue sections from 100 patients with primary CRC were assessed for the frequencies of focal basement membrane (BM) disruption, muscularis mucosa (MM) fragmentation, and tumor cell dissemination in epithelial structures adjacent and distal to infiltrating lymphoid aggregates using a panel of biomarkers and quantitative digital imaging.

RESULTS

Our study revealed: (1) epithelial structures adjacent to lymphoid follicles or aggregates had a significantly higher (p<0.001) frequency of focally disrupted BM, dissociated epithelial cells in the stroma, disseminated epithelial cells within lymphatic ducts or blood vessels, and fragmented MM than their distal counterparts, (2) a majority of dissociated epithelial cells within the stroma or vascular structures were immediately subjacent to or physically associated with infiltrating immune cells, (3) the junctions of pre-invasive and invasive lesions were almost exclusively located at sites adjacent to lymphoid follicles or aggregates, (4) infiltrating immune cells were preferentially associated with epithelial capsules that show distinct degenerative alterations, and (5) infiltrating immune cells appeared to facilitate tumor stem cell proliferation, budding, and dissemination.

CONCLUSIONS

Aberrant immune cell infiltration may have the same destructive impact on the capsule of all epithelium-derived tumors. This, in turn, may selectively favor the proliferation of tumor stem or progenitor cells overlying these focal disruptions. These proliferating epithelial tumor cells subsequently disseminate from the focal disruption leading to tumor invasion and metastasis.

Intra-operative transanal near infrared imaging of colorectal anastomotic perfusion: a feasibility study

AIM

Anastomotic dehiscence is a devastating complication. Inadequate blood supply is felt to be the prevailing cause. This study describes the use of near infrared imaging to evaluate transanally anastomotic tissue perfusion following low anterior resection.

METHOD

Twenty patients undergoing low anterior resection for benign and malignant disease were studied. After completing the anastomosis, indocyanine green (ICG) was injected via a peripheral intravenous catheter. An endoscopic near infrared imaging system (Pinpoint, Novadaq, Canada) was then used transanally to visualize mucosal perfusion of the colon, rectum and the anastomotic staple line.

RESULTS

All patients underwent a technically successful ICG angiogram. The angiogram was abnormal in four patients. Two of these had a protective loop ileostomy and showed no sign of anastomotic breakdown. The other two patients were found on CT scan to have a peri-anastomotic collection consistent with anastomotic leakage. Both were managed conservatively with resolution.

CONCLUSION

This study confirms that transanal ICG angiography is feasible and provides imaging of mucosal and anastomotic blood flow. The technique warrants further study in a larger group of patients to assess its ability to identify defects in tissue perfusion that may lead to anastomotic breakdown.

Rectal cap polyposis masquerading as ulcerative colitis with pseudopolyposis and presenting as chronic anemia: a case study with review of literature

Cap polyposis (CP) is an under recognized form of non-neoplastic colonic polyps, characterised by the presence of inflammatory polyps with a distinct "cap" of granulation tissue. CP is often seen masquerading as chronic inflammatory bowel disease. The most common symptoms are mucoid diarrhoea, bloody stools, abdominal pain, and tenesmus. In this case report, we present a patient who was diagnosed with CP during the investigation of unexplained chronic long standing anemia secondary to intermittent rectal bleeding. CP, although rare, should be considered in the differential diagnosis of patients presenting with intermittent rectal bleeding and mucoid diarrhoea.

Effectiveness of 5-flurouracil-based neoadjuvant chemotherapy in locally-advanced gastric/gastroesophageal cancer: A meta-analysis

AIM: To investigate the effectiveness of 5-flurouracil-based neoadjuvant chemotherapy (NAC) for gastroesophageal and gastric cancer by meta-analysis.

METHODS: MEDLINE and manual searches were performed to identify all published randomized controlled trials (RCTs) investigating the efficacy of the flurouracil-based NAC for gastroesophageal and gastric cancer, and RCTs of NAC for advanced gastroesophageal and gastric cancer vs no therapy before surgery. Studies that included patients with metastases at enrollment were excluded. Primary endpoint was the odds ratio (OR) for improving overall survival rate of patients with gastroesophageal and gastric cancer. Secondary endpoints were the OR of efficiency for down-staging tumor and increasing R0 resection in patients with gastroesophageal and gastric cancer. Safety analyses were also performed. The OR was the principal measurement of effect, which was calculated as the treatment group (NAC plus surgery) vs control group (surgery alone) and was presented as a point estimate with 95% confidence intervals (CI). All calculations and statistical tests were performed using RevMan 5.1 software.

RESULTS: Seven RCTs were included for the analysis. A total of 1249 patients with advanced gastroesophageal and gastric cancer enrolled in the seven trials were divided into treatment group (n = 620) and control group (n = 629). The quality scores of the RCTs were assessed according to the method of Jadad. The RCT quality scores ranged from 2 to 7 (5-point scale), with a mean of 3.75. The median follow-up time in these studies was over 3 years. The meta-analysis showed that NAC improved the overall survival rate (OR 1.40, 95%CI 1.11-1.76; P = 0.005), which was statistically significant. The 3-year progression-free survival rate was significantly higher in treatment group than in control group (37.7% vs 27.3%) (OR 1.62, 95%CI 1.21-2.15; P = 0.001). The tumor down-stage rate was higher in treatment group than in control group (55.76% vs 41.38%) (OR 1.77, 95%CI 1.27-2.49; P = 0.0009) and the R0 resection rate of the gastroesophageal and gastric cancer was higher in treatment group than in control group (75.11% vs 68.56%) (OR 1.38, 95%CI 1.03-1.85; P = 0.03), with significant differences. No obvious safety concerns about mortality and complications were raised in these trials. There were no statistically significant differences in perioperative mortality (5.08% vs 4.86%) (OR 1.05, 95%CI 0.57-1.94; P = 0.87 fixed-effect model) and in the complication rate between the two groups (13.25% vs 9.66%) (OR 1.40, 95%CI 0.91-2.14; P = 0.12 fixed-effect model). Trials showed that patients from Western countries favored NAC compared with those from Asian countries (OR 1.40, 95%CI 1.07-1.83). Monotherapy was inferior to multiple chemotherapy (OR 1.40, 95%CI 1.07-1.83). Intravenous administration of NAC was more advantageous than oral route (OR 1.41, 95%CI 1.09-1.81).

CONCLUSION: Flurouracil-based NAC can safely improve overall survival rate of patients with gastroesophageal/gastric cancer. Additionally, NAC can down the tumor stage and improve R0 resection.

Differentiating Branch Duct and Mixed IPMN in Endoscopically Collected Pancreatic Cyst Fluid via Cytokine Analysis

Background. Differentiating branch duct from mixed intraductal papillary mucinous neoplasm (BD-IPMN) is problematic, but clinically important as mixed IPMNs are managed surgically, while some BD-IPMN may be followed. Inflammatory mediator proteins (IMPs) have been implicated in acute and chronic inflammatory and malignant pancreatic diseases. Aim. To compare IMP profile of pancreatic cyst fluid collected endoscopically from BD-IPMN and mixed IPMN. Methods. Pancreatic cyst fluid from ten patients (5 BD-IPMN and 5 mixed IPMN) was collected by endoscopic ultrasound-guided fine needle aspiration or endoscopic retrograde cholangiopancreatography. Concentrations of 89 IMPs in these samples were determined using a multiplexed bead-based microarray protein assay and compared between BD-IPMN and mixed IPMN. Results. Eighty-six of 89 IMPs were detected in at least one of the 10 samples. Fourteen IMPs were detected only in mixed IPMN, while none were only in BD-IPMN. Of these, TGF-β1 was most prevalent, present in 3 of 5 mixed IPMNs. Seventy-two IMPs were detected in both BD-IPMN and mixed IPMNs. Of these, only G-CSF (P < 0.05) was present in higher concentrations in mixed IPMNs. Conclusion. TGF-β1 and G-CSF detected in endoscopically collected pancreatic cyst fluid are potential diagnostic biomarkers capable of distinguishing mixed IPMN from BD-IPMN.

Emerging robotic platforms for minimally invasive surgery

Recent technological advances in surgery have resulted in the development of a range of new techniques that have reduced patient trauma, shortened hospitalization, and improved diagnostic accuracy and therapeutic outcome. Despite the many appreciated benefits of minimally invasive surgery (MIS) compared to traditional approaches, there are still significant drawbacks associated with conventional MIS including poor instrument control and ergonomics caused by rigid instrumentation and its associated fulcrum effect. The use of robot assistance has helped to realize the full potential of MIS with improved consistency, safety and accuracy. The development of articulated, precision tools to enhance the surgeon's dexterity has evolved in parallel with advances in imaging and human-robot interaction. This has improved hand-eye coordination and manual precision down to micron scales, with the capability of navigating through complex anatomical pathways. In this review paper, clinical requirements and technical challenges related to the design of robotic platforms for flexible access surgery are discussed. Allied technical approaches and engineering challenges related to instrument design, intraoperative guidance, and intelligent human-robot interaction are reviewed. We also highlight emerging designs and research opportunities in the field by assessing the current limitations and open technical challenges for the wider clinical uptake of robotic platforms in MIS.

Near infrared fluorescence for image-guided surgery

Near infrared (NIR) image-guided surgery holds great promise for improved surgical outcomes. A number of NIR image-guided surgical systems are currently in preclinical and clinical development with a few approved for limited clinical use. In order to wield the full power of NIR image-guided surgery, clinically available tissue and disease specific NIR fluorophores with high signal to background ratio are necessary. In the current review, the status of NIR image-guided surgery is discussed along with the desired chemical and biological properties of NIR fluorophores. Lastly, tissue and disease targeting strategies for NIR fluorophores are reviewed.

SOD mimetic improves the function, growth, and survival of small-size liver grafts after transplantation in rats

BACKGROUND

Small-for-size syndrome (SFSS) may occur when graft volume is less than 45% of the standard liver volume, and it manifests as retarded growth and failure of the grafts and more mortality. However, its pathogenesis is poorly understood, and few effective interventions have been attempted.

AIMS

The present study aimed to delineate the critical role of oxidant stress in SFSS and protective effects of a superoxide dismutase mimetic, Mn(III)tetrakis(4-benzoic acid)porphyrin chloride (MnTBAP), on graft function, growth, and survival in the recipient rats.

METHODS

Small size graft liver transplantation (SSGLT) was performed to determine the survival, graft injury, and growth. MnTBAP was administered in SSGLT recipients (SSGLT+MnTBAP).

RESULTS

Serum alanine aminotransferase levels were sustained higher in SSGLT recipients, which were correlated with an increased apoptotic cell count and hepatocellular necrosis in liver sections. Malondialdehyde content, gene expression of tumor necrosis factor α and interleukin 1β, and DNA binding activity of nuclear factor-κB in the grafts were increased significantly in SSGLT recipients compared with sham-operated controls. Both phosphorylated p38 mitogen-activated protein kinase and nuclear c-Jun were increased in SSGLT. All these changes were strikingly reversed by the administration of MnTBAP, with an increase in serum superoxide dismutase activity. Moreover, in situ bromodeoxyuridine incorporation demonstrated that graft regeneration was much more profound in the SSGLT+MnTBAP group than in the SSGLT group. Finally, the survival of recipients with MnTBAP treatments was significantly improved.

CONCLUSIONS

Enhanced oxidant stress with activation of the p38/c-Jun/nuclear factor-κB signaling pathway contributes to SFSS-associated graft failure, retarded graft growth, and poor survival. MnTBAP effectively reversed the pathologic changes in SFSS-associated graft failure.

Effects of different electroacupuncture scheduling regimens on murine bone tumor-induced hyperalgesia: sex differences and role of inflammation

Previous studies have shown that electroacupuncture (EA) is able to reduce hyperalgesia in rodent models of persistent pain, but very little is known about the analgesic effects and potential sex differences of different EA treatment regimens. In the present study, we examined the effects of five different EA treatments on tumor-induced hyperalgesia in male and female mice. EA applied to the ST-36 acupoint either twice weekly (EA-2X/3) beginning on postimplantation day (PID) 3 or prophylactically three times prior to implantation produced the most robust and longest lasting antinociceptive effects. EA treatment given once per week beginning at PID 7 only produced an antinociceptive effect in female animals. The analgesic effect of EA-2X/3 began earlier in males, but lasted longer in females indicating sex differences in EA. We further demonstrate that EA-2X/3 elicits a marked decrease in tumor-associated inflammation as evidenced by a significant reduction in tumor-associated neutrophils at PID 7. Moreover, EA-2X/3 produced a significant reduction in tumor-associated PGE₂ as measured in microperfusate samples. Collectively, these data provide evidence that EA-2X/3 treatment reduces tumor-induced hyperalgesia, which is associated with a decrease in tumor-associated inflammation and PGE₂ concentration at the tumor site suggesting possible mechanisms by which EA reduces tumor nociception.

Needs analysis for developing a virtual-reality NOTES simulator

INTRODUCTION AND STUDY AIM: Natural orifice translumenal endoscopic surgery (NOTES) is an emerging surgical technique that requires a cautious adoption approach to ensure patient safety. High-fidelity virtual-reality-based simulators allow development of new surgical procedures and tools and train medical personnel without risk to human patients. As part of a project funded by the National Institutes of Health, we are developing the virtual transluminal endoscopic surgery trainer (VTEST) for this purpose. The objective of this study is to conduct a structured needs analysis to identify the design parameters for such a virtual-reality-based simulator for NOTES.

METHODS

A 30-point questionnaire was distributed at the 2011 National Orifice Surgery Consortium for Assessment and Research meeting to obtain responses from experts. Ordinal logistic regression and the Wilcoxon rank-sum test were used for analysis.

RESULTS

A total of 22 NOTES experts participated in the study. Cholecystectomy (CE, 68 %) followed by appendectomy (AE, 63 %) (CE vs AE, p = 0.0521) was selected as the first choice for simulation. Flexible (FL, 47 %) and hybrid (HY, 47 %) approaches were equally favorable compared with rigid (RI, 6 %) with p < 0.001 for both FL versus RI and HY versus RI. The transvaginal approach was preferred 3 to 1 to the transgastric. Most participants preferred two-channel (2C) scopes (65 %) compared with single (1C) or three (3C) or more channels with p < 0.001 for both 2C versus 1C and 2C versus 3C. The importance of force feedback and the utility of a virtual NOTES simulator in training and testing new tools for NOTES were rated very high by the participants.

CONCLUSION

Our study reinforces the importance of developing a virtual NOTES simulator and clearly presents expert preferences. The results of this analysis will direct our initial development of the VTEST platform.

Adult ileo-ileo-caecal intussusception: case report and literature review

Adult intussusception is a rare entity accounting for only 5% of all intussusceptions and causes approximately 1% of all adult intestinal obstructions. Unlike paediatric intussusceptions which are usually idiopathic, there is usually a lead point pathology which might be malignant in up to 50% cases. We present an unusual case of adult intussusception which was not diagnosed on any investigation including computerized tomographic (CT) scan and magnetic resonance imaging (MRI). It was a case of ileo-ileo-cecal intussusception caused by a large lipoma 38 mm × 43 mm × 61 mm. It was treated by emergency laparotomy for acute intestinal obstruction. A conservative resection with ileostomy was performed with good postoperative recovery.

Robotic transanal access surgery

Transanal use of laparoscopic instrumentation has been described in several case reports as an alternative to transanal endoscopic microsurgery (TEM). Both of these techniques have significant technical limitations due to anatomical constrictions. Robotic technology with articulating instruments has been effectively used in many areas with anatomic limitations similar to the intraluminal use within the rectum. We present the technique of a full-thickness transanal resection of a rectal polyp with endorectal suturing using a robotic platform. Larger case series and trials are needed to compare outcome and cost with TEM. Alternative robotic platforms and instrumentation may be further developed for different and more advanced indications of transanal access surgery.

Transanal single-port access microsurgery (TSPAM)

Transanal single-port access microsurgery (TSPAM) is an emerging and feasible minimally invasive method for the transanal excision of large sessile adenomas and early-stage carcinomas of the rectum. Here we present our TSPAM experience on rectal adenomas (high-grade rectal adenomas in 5 cases and carcinoma in situ in 1 case). TSPAM is an innovative method that can be an affordable and disseminated alternative to transanal endoscopic microsurgery for the local excision of the rectal lesions.

The pivotal role of TBK1 in inflammatory responses mediated by macrophages

Inflammation is a complex biological response of tissues to harmful stimuli such as pathogens, cell damage, or irritants. Inflammation is considered to be a major cause of most chronic diseases, especially in more than 100 types of inflammatory diseases which include Alzheimer's disease, rheumatoid arthritis, asthma, atherosclerosis, Crohn's disease, colitis, dermatitis, hepatitis, and Parkinson's disease. Recently, an increasing number of studies have focused on inflammatory diseases. TBK1 is a serine/threonine-protein kinase which regulates antiviral defense, host-virus interaction, and immunity. It is ubiquitously expressed in mouse stomach, colon, thymus, and liver. Interestingly, high levels of active TBK1 have also been found to be associated with inflammatory diseases, indicating that TBK1 is closely related to inflammatory responses. Even though relatively few studies have addressed the functional roles of TBK1 relating to inflammation, this paper discusses some recent findings that support the critical role of TBK1 in inflammatory diseases and underlie the necessity of trials to develop useful remedies or therapeutics that target TBK1 for the treatment of inflammatory diseases.

Conservative treatment in isolated penetrating cervical esophageal injury: case report

Non-iatrogenic traumatic cervical esophageal perforations are usually hard to manage in the clinical setting, and often require a careful and individualized approach. The low incidence of this particular problem leads to a restricted clinical experience among most centers and justify the lack of a standardized surgical approach. Conservative treatment of esophageal perforation remains a controversial topic, although early and sporadic reports have registered the efficacy of non-operative care, especially following perforation in patients that do not sustain any other kind of injuries, and who are hemodynamically stable and non-septic. We report a case of a patient sustaining a single cervical gunshot wound compromising the cervical esophagus and who was treated exclusively with cervical drainage, enteral support and antibiotics.

Operative management of recurrent choledocholithiasis

INTRODUCTION

With the advent of endoscopic and image-directed percutaneous approaches, it is increasingly uncommon to require a surgical approach for recurrent bile duct stones.

TECHNIQUE

We describe open side-to-side choledochoduodenostomy as one of the surgical options for recurrent bile duct stones. This procedure includes the following elements: exposure of the common bile duct, mobilization of the duodenum (Kocher maneuver), choledochotomy, inspection of the bile duct with a choledochoscopy, and anastomosis of the bile duct with the duodenum. Other options for operative management are discussed.

CONCLUSION

Surgical drainage procedures for recurrent bile duct stones can be performed for patients who fail to respond to endoscopic and nonoperative interventional treatments with good long-term outcomes.

Treatment of post-liver transplant hepatic artery pseudoaneurysm with balloon angioplasty after failed stent graft placement

Hepatic artery pseudoaneurysm is a rare complication following liver transplantation but can lead to life threatening hemorrhage if not treated effectively and in a timely manner. We describe a hepatic artery pseudoaneurysm that occurred after liver transplantation in a 53-year-old woman. The pseudoaneurysm was initially treated by implantation of a balloon-expandable covered stent-graft, but an endoleak was observed 6 days later. The endoleak was successfully resolved by further balloon angioplasty, which expanded the cylindrical stent to a conical stent, matching the anatomy of the anastomotic hepatic artery. Follow-up ultrasound examinations demonstrated patent hepatic arteries, with no evidence of pseudoaneurysm. Balloon-expandable covered stent-graft may be utilized to treat hepatic artery pseudoaneurysm following liver transplantation, due to the remodeling ability of stent-grafts, enabling them to fit the diseased vessels.

Thyroid function and stress hormones in children with stress hyperglycemia

The purpose of the study is to determine the prevalence of stress hyperglycemia and to investigate how thyroid and stress hormones alter during stress hyperglycemia in children admitted to pediatric emergency wards. A prospective cross-sectional study was conducted in children, less than 19 years old, who were admitted to pediatric emergency wards of Nemazee and Dastgheib Hospitals, Shiraz, Southern Iran. Those patients taking steroids, beta-agonists or intravenously administered glucose before venipuncture, and patients with diabetes mellitus (DM) or thyroid diseases were excluded. Children with blood glucose ≥ 150 mg/dL during admission were regarded as cases. The controls were age- and- sex- matched, euglycemic children. Stress hormones including cortisol, insulin, growth hormone, and prolactin were measured, and thyroid function was tested with a radioimmunoassay (RIA) method in all cases and controls. The results showed that among 1,054 screened children, 39 cases (3.7 %) had stress hyperglycemia and 89 controls were included in the study. The occurrence of hyperglycemia was independent of sex, but it occurred mostly in children under 6 years old. Hyperglycemia occurred more frequently in patients with a positive family history of DM (odds ratio = 3.2, 95 % CI = 1.3-7.9, and P = 0.009). There were no significant differences between cases and controls regarding any hormones except higher cortisol, and lower total T3 and T4 in cases compared with controls. Neither of cases developed diabetes in the 24-month follow-up period. These findings led us to the conclusion that stress hyperglycemia is occasionally seen in critically ill patients. Among the stress hormones measured, only cortisol increased during hyperglycemia. It seems that hyperglycemia is not an important risk factor for future diabetes.

Percutaneous placement and management of the Denver shunt for portal hypertensive ascites

OBJECTIVE

Many patients with cirrhotic effusions in the peritoneal and pleural spaces lead a difficult existence. In addition to their decreased mobility and physical discomfort, they spend hours in the hospital or an outpatient facility undergoing peritoneal and pleural drainage. Liver transplantation is the ultimate solution for those with cirrhotic effusions refractory to medical management; however, most are on a long waiting list, forcing them to undergo a year or more of percutaneous centesis. Transjugular intrahepatic portosystemic shunts offer relief to those with cirrhotic ascites but at the cost of accelerated hepatic failure and hepatic encephalopathy. This article will review the development of the peritoneovenous and pleurovenous shunt, discuss reasons for its loss of favor, and suggest its current role in the armamentarium of the interventional radiologist.

CONCLUSION

Peritoneovenous and pleurovenous shunt creation is a procedure that has the potential to significantly improve the quality of life of the patient by controlling the fluid collections, reducing dependence on frequent drainage procedures, improving renal function, and reducing protein loss.

Quality of life in patients with chronic anal fissure after topical treatment with diltiazem

AIM: To assess the physical and mental health of fissure patients before and after topical treatment with diltiazem.

METHODS: Consecutive patients were enrolled prospectively into the study. Quality of life was measured with the short-forum 36 health survey (SF-36) before and after 6-wk treatment with diltiazem. Patients scored symptoms of pain, bleeding, and irritation using numeral rating scales at the initial and follow-up visits. Fissure healing was assessed and side effects were noted.

RESULTS: Fissures healed in 21 of 30 (70%) patients. There were significant reductions in the scores of pain, bleeding, and irritation after 1 wk of treatment, respectively. Four patients experienced perianal itching and one patient reported headache. When measured at baseline, pain and irritation showed a negative impact on two of the eight subscales on the SF-36, respectively (bodily pain and social functioning for pain; vitality and mental health for irritation). Repeating the SF-36 showed an improvement in bodily pain (P = 0.001). Patients whose fissures healed reported an improvement in bodily pain, health-perception, vitality, and mental health (P < 0.05).

CONCLUSION: Successful treatment of chronic anal fissure with topical diltiazem leads to improvement in health-related quality of life.

Transanal glove port is a safe and cost-effective alternative for transanal endoscopic microsurgery

BACKGROUND

Transanal endoscopic microsurgery (TEM) is a minimally invasive technique for excision of rectal tumours that avoids conventional pelvic resectional surgery along with its risks and side-effects. Although appealing, the associated cost and complex learning curve limit TEM utilization by colorectal surgeons. Single-port laparoscopic principles are being recognized as transferable to transanal work and hybrid techniques are in evolution. Here the clinical application of a new technique for transanal access is reported.

METHODS

Consecutive non-selected patients eligible for TEM over a 3-month period (and selected patients thereafter) were offered a procedure performed via a 'glove TEM port'. This access device was constructed on-table using a circular anal dilator (CAD), wound retractor and standard surgical glove, along with standard, straight laparoscopic trocar sleeves and instruments.

RESULTS

Fourteen patients underwent full-thickness resection of benign (8) or malignant (6) rectal pathology. CAD insertion failed in one patient and conventional TEM assistance was needed in another, leaving 12 procedures completed successfully by glove TEM alone as planned (completion rate 86 per cent overall, 92 per cent after initiation). The median (range) duration of operation and resected specimen area were 93 (30-120) min and 12 (3-152) cm(2) respectively. There was no intraoperative and minimal postoperative morbidity, with a median follow-up of 5.7 (2.7-9.4) months.

CONCLUSION

The glove TEM port is a safe, inexpensive and readily available access tool that may obviate the use of specialized equipment for transanal resection of rectal lesions.

Laparoscopic assisted transvaginal cholecystectomy: single centre preliminary experience

BACKGROUND

Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a new approach that allows abdominal surgery to be performed through a natural orifice such as the oral cavity, vagina or rectum. We present our preliminary experience of laparoscopic assisted transvaginal cholecystectomy (LATC).

METHODS

Women affected by cholelithiasis, age below 65 years, BMI under 30, ASA I or II, previous full-term pregnancies, and without previous abdominal surgery underwent LATC. Patients' biographic data, operative time, intraoperative and postoperative complications were collected.

RESULTS

We performed 21 LATCs. Median operative time was 58 min. There were no intraoperative complications. The postoperative course was uneventful in all patients. At 1 year there were no complications and no impaired sexual activity.

CONCLUSIONS

The results of NOTES are promising, but currently only hybrid NOTES can be safely performed. LATC seems to guarantee better cosmetic results, less postoperative pain, faster mobilization and shorter hospitalization than laparoscopic cholecystectomy.

Aberrant expression of CD133 in non-small cell lung cancer and its relationship to vasculogenic mimicry

Background

To investigate on expressions and clinical significances of CD133 protein and vasculogenic mimicry (VM) in primary non-small cell lung cancer (NSCLC).

Methods

The specimens of NSCLC from 305 Chinese patients with follow-up were analyzed for CD133 protein expression and VM by immunohistochemical and histochemical staining.

Results

In NSCLC, positive rates of 48.9% and 35.7% were obtained for CD133 and VM, respectively. The VM and expression of CD133 were significantly higher in carcinoma than in normal. There were a positive relationship between the VM and expression of CD133 and the tumor grade, lymph node metastasis and clinical stage (all P<0.05). The overall mean survival time of the patients with CD133 and VM positive expression was lower than that of patients with negative expression. Microvessel density (MVD) was positive corresponded with the grade, lymph node metastasis and clinical stage (all P<0.05). The overall mean survival time of the patients with MVD≥22’s group was shorter than that of patients with MVD<22’s group. Pathological-tumor-node-metastasis (pTNM) stage, positive expression of CD133 and VM, postoperative therapy and MVD were independent prognostic factors of NSCLC (P<0.05). Immunohistochemistry revealed an important intratumoral heterogeneity in all four CD133 expression profiles.

Conclusions

VM, MVD and expression of CD133 are related to differentiation, lymph node metastasis, clinical stage, and prognosis. It is suggested that CD133, VM and MVD should be considered as a potential marker for the prognosis.

Modeling the hepatic arterial buffer response in the liver

In this paper we present an electrical analog model for the hepatic arterial buffer response (HABR), an intrinsic regulation mechanism in the liver whereby the arterial flow counteracts the changes in portal venous flow. The model itself is a substantial simplification of a previously published model, with nonlinear arterial and portal resistors introduced to account for the dynamic HABR effects. We calibrate the baseline model using published hemodynamic data, and then perform a virtual portal occlusion simulation where the portal vein is half or fully occluded. The simulation results, which suggest that the increased arterial flow cannot fully compensate lost portal perfusion, are consistent with clinical reports and animal model findings. Since HABR functions in both the whole liver and liver graft after transplantation, we also simulate blood flow in a virtual right-lobe graft by adjusting the electronic component parameters in the electric circuit, and our model is able to reproduce the portal venous hyperperfusion and hepatic arterial hypoperfusion conditions due to the HABR effects.

Surgery for a gastric Dieulafoy's lesion reveals an occult bleeding jejunal diverticulum. A case report

Background

Jejunal diverticulosis is an uncommon disease and usually asymptomatic. It can be complicated not only by diverticulitis, but by hemorrhage, perforation, intussusception, volvulus, malabsorption and even small bowel obstruction due to enteroliths formed and expelled from these diverticula.

Methods

We describe a case of an occult bleeding jejunal diverticulum, casually discovered in a patient that was taken to surgery for a Dieulafoy’s lesion after unsuccessful endoscopic treatment. We performed a gastric resection together with an ileocecal resection.

Macroscopic and microscopic examinations confirmed the gastric Dieulafoy’s lesion and demonstrated the presence of another source of occult bleeding in asymptomatic jejunal diverticulum.

Discussion

The current case emphasizes that some gastrointestinal bleeding lesions, although rare, can be multiple and result in potentially life-threatening bleeding. The clinician must be mindful to the possibility of multisite lesions and to the correlation between results of the investigations and clinical condition of the bleeding patient.

Evolution of pancreatoduodenectomy in a tertiary cancer center in India: improved results from service reconfiguration

BACKGROUND

Pancreatic cancer incidence in India is low. Over the years, refinements in technique of pancreatoduodenectomy (PD) may have improved outcomes. No data is available from India, South-Central, or South West Asia to assess the impact of these refinements.

PURPOSE

To assess the impact of service reconfiguration and standardized protocols on outcomes of PD in a tertiary cancer center in India.

METHODS

Three specific time periods marking major shifts in practice and performance of PD were identified, viz. periods A (1992-2001; pancreaticogastrostomy predominantly performed), B (2003-July 2009; standardization of pancreaticojejunal anastomosis), and C (August 2009-December 2011; introduction of neoadjuvant chemo-radiotherapy and increased surgical volume).

RESULTS

500 PDs were performed with a morbidity and mortality rate of 33% and 5.4%, respectively. Over the three periods, volume of cases/year significantly increased from 16 to 60 (p < 0.0001). Overall incidence of post-operative pancreatic anastomotic leak/fistula (POPF), hemorrhage, delayed gastric emptying (DGE), and bile leak was 11%, 6%, 3.4%, and 3.2%, respectively. The overall morbidity rates, as well as, the above individual complications significantly reduced from period A to B (p < 0.01) with no statistical difference between periods B and C.

CONCLUSION

Evolution of practice and perioperative management of PD for pancreatic cancer at our center improved perioperative outcomes and helped sustain the improvements despite increasing surgical volume. By adopting standardized practices and gradually improving experience, countries with low incidence of pancreatic cancer and resource constraints can achieve outcomes comparable to high-incidence, developed nations.

SYNOPSIS

The manuscript represents the largest series on perioperative outcomes for pancreatoduodenectomy from South West and South-Central Asia - a region with a low incidence of pancreatic cancer and a disproportionate distribution of resources highlighting the impact of high volumes, standardization and service reconfiguration.

The damage control sequence in the elderly: Strategy, complexities, and outcomes

Traditional management in cases of exsanguinating abdominal trauma led to poor outcomes in critically injured patients. Because prolonged operations were not well tolerated due to the severe physiologic derangements, an abbreviated laparotomy began to be used. Patients were then resuscitated in the intensive care unit and brought back to the operating room once their physiology had been normalised. This approach has been termed the damage control sequence. Elderly trauma patients are susceptible to significant injury that may mandate a damage control sequence. For myriad reasons, including pre-existing medical conditions, decreased physiologic reserve, and the emergent nature of their injuries, the application of this management approach in the elderly is fraught with challenges. The purpose of this review is to enumerate the damage control sequence, describe the complexities of its use in the elderly, and discuss associated outcomes in this challenging patient population.