Effects of acute and sub-acute hypobaric hypoxia on oxidative stress: a field study in the Alps.

PURPOSE: High altitude results in lower barometric pressure and hence partial pressure of O2 decrease can lead to several molecular and cellular changes, such as generation of reactive oxygen species (ROS). Electron Paramagnetic Resonance technique was adopted in the field, to evaluate the effects of acute and sub-acute hypobaric hypoxia (HH) on ROS production by micro-invasive method. Biological biomarkers, indicators of oxidative stress, renal function and inflammation were investigated too. METHODS: Fourteen lowlander subjects (mean age 27.3 ± 5.9 years) were exposed to HH at 3269 m s.l. ROS production, related oxidative damage to cellular components, systemic inflammatory response and renal function were determined through blood and urine profile performed at 1st, 2nd, 4th, 7th, and 14th days during sojourn. RESULTS: Kinetics of changes during HH exposition showed out significant (range p < 0.05-0.0001) increases that at max corresponds to 38% for ROS production rate, 140% for protein carbonyl, 44% for lipid peroxidation, 42% for DNA damage, 200% for inflammatory cytokines and modifications in renal function (assessed by neopterin concentration: 48%). Conversely, antioxidant capacity significantly (p < 0.0001) decreased - 17% at max. CONCLUSION: This 14 days in-field study describes changes of oxidative-stress biomarkers during HH exposure in lowlanders. The results show an overproduction of ROS and consequent oxidative damage to protein, lipids and DNA with a decrease in antioxidant capacity and the involvement of inflammatory status and a transient renal dysfunction. Exposure at high altitude induces a hypoxic condition during acute and sub-acute phases accompanied by molecular adaptation mechanism indicating acclimatization.

Ileal pouch-anal anastomosis with fluorescence angiography: a case-matched study.

AIM: An anastomotic leak in ileoanal pouch surgery may lead to pouch failure. Constructing a tension-free ileal pouch-anal anastomosis (IPAA) reduces this risk but can be technically challenging, balancing pouch vascularization with ileal mesenteric length and site of vessel ligation. Fluorescence angiography (FA) may help the clinician make a more balanced judgement. METHODS: Thirty-two patients undergoing minimally invasive completion proctectomy with FA-guided IPAA at two academic centres were matched and compared on a 1:1 basis to a historical group undergoing the same procedure without the use of this technique. RESULTS: Ligation of the ileocolic vessels was safely performed in 15/32 (47%) of FA patients compared with 5/32 (16%) of historical controls. One patient underwent intra-operative IPAA reconstruction after FA detected ischaemia. No anastomotic leak occurred with FA but there was only one in the historical controls (P = 0.31). The postoperative complication rate was similar between the two groups (P = 0.60). CONCLUSION: FA is applicable to IPAA surgery and may help to reduce perfusion-related anastomotic leaks. A prospective randomized trial is warranted.

Evaluation of the MDACC clinical classification system for pancreatic cancer patients in an European multicenter cohort.

BACKGROUND: The MDACC group recommends to extend the current borderline classification for pancreatic cancer into three groups: type A patients with resectable/borderline tumor anatomy, type B with resectable/borderline resectable tumor anatomy and clinical findings suspicious for extrapancreatic disease and type C with borderline resectable and marginal performance status/severe pre-existing comorbidity profile or age>80. This study intents to evaluate the proposed borderline classification system in a multicenter patient cohort without neoadjuvant treatment. METHODS: Evaluation was based on a multicenter database of pancreatic cancer patients undergoing surgery from 2005 to 2016 (n = 1020). Complications were classified based on the Clavien-Dindo classification. χ2-test, Kaplan-Meier estimator and Cox regression hazard model were used for statistical analysis. RESULTS: Most patients (55.1%) were assigned as type A patients, followed by type C (35.8%) and type B patients (9.1%). Neither the complication rate, nor the mortality rate revealed a correlation to any subgroup. Type B patients had a significant worse progression free (p < 0.001) and overall survival (p = 0.005). Type B classification was identified as an independent prognostic marker for progression free survival (p = 0.005, HR 1.47). CONCLUSION: The evaluation of the proposed classification in a cohort without neoadjuvant treatment did not justify an additional medical borderline subgroup. A new subgroup based on prognostic borderline patients might be the main target group for neoadjuvant protocols in future.

Parenchyma-sparing surgery for pancreatic endocrine tumors.

Enucleation (EN) and middle pancreatectomy (MP) have been proposed as a treatment for G1 and G2 pancreatic neuroendocrine tumors (PNET). The aim of this study is to analyze the outcomes of parenchyma-sparing surgery (PSS) for PNET in an Italian high-volume center. All patients with a histological diagnosis of PNET who underwent surgical resection in our center between January 2010 and January 2016 were included in the study. Demographic, perioperative, and discharge data were collected in a prospective database. Follow-up was considered until March 31, 2016. 99 patients were included. PSS was performed in 22 cases (22.2 %), 18 EN (82 %), and 4 MP (18 %). 89.8 % patients were staged with CT scan, 69.6 % with endoscopic ultrasonography, 48.4 % with MRI, and 47.4 % with 68Ga-PET. Pre-operative histological diagnosis was obtained in 68.6 %. Most of PSS tumors were G1 (n = 15; 68 %) and there were no G3. Nodal sampling was performed in every PSS. Only two patients showed nodal metastatic disease. The median post-operative length of stay was 7 days after PSS. Eleven (50 %) of these patients developed a complication; two (18.2 %) were major complications. Pancreatic fistula developed in ten patients (45.5 %); two (20 %) were type B. There were no type C fistula and no re-operations after PSS. Readmission rate was 9 %. All patients submitted to PSS are alive and free of recurrence. PSS is a safe technique for G1 and G2 PNETs, but it has to be conducted in experienced centers and an extensive nodal sampling and a long follow-up are required for the best oncologic outcome.

Molecular heterogeneity and prognostic implications of synchronous advanced colorectal neoplasia.

BACKGROUND: It is uncertain whether synchronous colorectal cancers (S-CRCs) preferentially develop through widespread DNA methylation and whether they have a prognosis worse than solitary CRC. As tumours with microsatellite instability (MSI) may confound the effect of S-CRC methylation on outcome, we addressed this issue in a series of CRC characterised by BRAF and MS status. METHODS: Demographics, clinicopathological records and disease-specific survival (DSS) were assessed in 881 consecutively resected CRC undergoing complete colonoscopy. All tumours were typed for BRAF(c.1799T>A) mutation and MS status, followed by search of germ-line mutation in patients with MSI CRC. RESULTS: Synchronous colorectal cancers (50/881, 5.7%) were associated with stage IV microsatellite-stable (MSS) CRC (19/205, 9.3%, P=0.001) and with HNPCC (9/32, 28%, P<0.001). BRAF mutation (60/881, 6.8%) was associated with sporadic MSI CRC (37/62, 60%, P<0.001) but not with S-CRC (3/50, 6.0%, P=0.96). Synchronous colorectal cancer (HR 1.82; 95% CI 1.15-2.87; P=0.01), synchronous advanced adenoma (HR 1.81; 95% CI 1.27-2.58; P=0.001), and BRAF(c.1799T>A) mutation (HR 2.16; 95% CI 1.25-3.73; P=0.01) were stage-independent predictors of death from MSS CRC. Disease-specific survival of MSI CRC patients was not affected by S-CRC (HR 0.74; 95% CI 0.09-5.75; P=0.77). CONCLUSION: Microsatellite-stable CRCs have a worse prognosis if S-CRC or synchronous advanced adenoma are diagnosed. The occurrence and the enhanced aggressiveness of synchronous MSS advanced neoplasia are not associated with BRAF mutation.

Early expression of the fractalkine receptor CX3CR1 in pancreatic carcinogenesis.

BACKGROUND: In pancreatic ductal adenocarcinoma (PDAC), fractalkine receptor CX3CR1 contributes to perineural invasion (PNI). We investigated whether CX3CR1 expression occurs early in PDAC and correlates with tumour features other than PNI. METHODS: We studied CX3CR1 and CX3CL1 expression by immunohistochemistry in 104 human PDAC and coexisting Pancreatic Intraepithelial Neoplasia (PanIN), and in PdxCre/LSL-Kras(G12D) mouse model of PDAC. CX3CR1 expression in vitro was studied by a spheroid model, and in vivo by syngenic mouse graft of tumour cells. RESULTS: In total, 56 (53.9%) PDAC expressed CX3CR1, 70 (67.3%) CX3CL1, and 45 (43.3%) both. CX3CR1 expression was independently associated with tumour glandular differentiation (P=0.005) and PNI (P=0.01). Pancreatic Intraepithelial Neoplasias were more frequently CX3CR1+ (80.3%, P<0.001) and CX3CL1+ (86.8%, P=0.002) than matched cancers. The survival of PDAC patients was better in those with CX3CR1+ tumour (P=0.05). Mouse PanINs were also CX3CR1(+) and -CL1(+). In vitro, cytokines significantly increased CX3CL1 but not CX3CR1 expression. Differently, CX3CR1 was upregulated in tumour spheroids, and in vivo only in well-differentiated tumours. CONCLUSION: Tumour differentiation, rather than inflammatory signalling, modulates CX3CR1 expression in PanINs and PDAC. CX3CR1 expression pattern suggests its early involvement in PDAC progression, outlining a potential target for interfering with the PanIN transition to invasive cancer.

Minilaparoscopic colorectal resections: technical note.

Laparoscopic colorectal resections have been shown to provide short-term advantages in terms of postoperative pain, general morbidity, recovery, and quality of life. To date, long-term results have been proved to be comparable to open surgery irrefutably only for colon cancer. Recently, new trends keep arising in the direction of minimal invasiveness to reduce surgical trauma after colorectal surgery in order to improve morbidity and cosmetic results. The few reports available in the literature on single-port technique show promising results. Natural orifices endoscopic techniques still have very limited application. We focused our efforts in standardising a minilaparoscopic technique (using 3 to 5 mm instruments) for colorectal resections since it can provide excellent cosmetic results without changing the laparoscopic approach significantly. Thus, there is no need for a new learning curve as minilaparoscopy maintains the principle of instrument triangulation. This determines an undoubted advantage in terms of feasibility and reproducibility of the procedure without increasing operative time. Some preliminary experiences confirm that minilaparoscopic colorectal surgery provides acceptable results, comparable to those reported for laparoscopic surgery with regard to operative time, morbidity, and hospital stay. Randomized controlled studies should be conducted to confirm these early encouraging results.

miR-296 regulation of a cell polarity-cell plasticity module controls tumor progression.

The expression of small, non-coding RNA or microRNAs (miR), is frequently deregulated in human cancer, but how these pathways affect disease progression is still largely elusive. Here, we report on a miR, miR-296, which is progressively lost during tumor progression and correlates with metastatic disease in colorectal, breast, lung, gastric, parathyroid, liver and bile ducts cancers. Functionally, miR-296 controls a global cell motility gene signature in epithelial cells by transcriptionally repressing the cell polarity-cell plasticity module, Scribble (Scrib). In turn, loss of miR-296 causes aberrantly increased and mislocalized Scrib in human tumors, resulting in exaggerated random cell migration and tumor cell invasiveness. Re-expression of miR-296 in MDA-MB231 cells inhibits tumor growth in vivo. Finally, miR-296 or Scrib levels predict tumor relapse in hepatocellular carcinoma patients. These data identify miR-296 as a global repressor of tumorigenicity and uncover a previously unexplored exploitation of Scrib in tumor progression in humans.

Prospective comparison of computed tomography enterography and magnetic resonance enterography for assessment of disease activity and complications in ileocolonic Crohn's disease.

BACKGROUND: Studies comparing magnetic resonance enterography (MRE) and computerized tomography enterography (CTE) for Crohn's disease (CD) are scarce. METHODS: The aim of this study was to prospectively compare the sensitivity, specificity, and accuracy of abdominal MRE and CTE to assess disease activity and complications (fistulas, strictures) in ileocolonic CD. A total of 44 patients (23 male; 21 female; mean age 44) with ileocolonic CD underwent both MR and CT in a short time interval (mean 5 days). A 16-slice CT with intravenous contrast and an MRI with oral and paramagnetic intravenous contrast were performed. Ileocolonoscopy was used as the reference standard. Sensitivity values of CT and MR for detection of extraenteric signs of disease were compared with the McNemar test, with results of imaging studies, surgery, and physical examination as reference standards. RESULTS: No significant differences in sensitivity, specificity, and accuracy were observed between MRE and CTE regarding the following parameters at the patient level: localization of CD (P = 1.0), bowel wall thickening (P = 1.0), bowel wall enhancement (P = 1.0), enteroenteric fistulas (P = 0.08), detection of abdominal nodes (P = 1.0), and perivisceral fat enhancement (P = 0.31). MR was significantly superior compared to CT in detecting strictures (P = 0.04). Per segment analysis showed that MRE was significantly superior to CTE in detecting ileal wall enhancement (P = 0.02). CONCLUSIONS: MR and CT are equally accurate to assess disease activity and bowel damage in CD. MR may be superior to CT in detecting intestinal strictures and ileal wall enhancement. MR may represent an alternative technique to CT in assessing ileocolonic CD.

Intraoperative ultrasonographic detection of communicating veins between adjacent hepatic veins during hepatectomy for tumours at the hepatocaval confluence.

BACKGROUND: The presence of communicating veins between adjacent hepatic veins may allow parenchyma-sparing hepatectomy. Taking advantage of improvements in ultrasound technology, such as e-flow modality, a study of the presence of communicating veins was conducted in patients with hepatic tumours at the caval confluence. METHODS: Consecutive patients undergoing surgery between October 2007 and December 2009 for hepatic tumours in contact with or invading a hepatic vein at its caval confluence were included. Communicating vein mapping by means of e-flow intraoperative ultrasonography (EF-IOUS) was carried out. RESULTS: A total of 20 patients were enrolled. Communicating veins between adjacent hepatic veins or with the inferior vena cava were detected in 16 patients. The median number of communicating veins was 1 (range 0-5). The total number of lesions removed was 126 (range 1-46). In 11 of 12 patients requiring resection of a hepatic vein, communicating veins enabled a parenchyma-sparing procedure to be performed. No patient had a formal major hepatectomy. There was no postoperative mortality or major morbidity. CONCLUSION: EF-IOUS estimation of the frequency of communicating veins between adjacent hepatic veins suggests that such veins are common. This may facilitate parenchyma-sparing procedures in patients with hepatic tumours encroaching on major hepatic veins.

Laparoscopic liver resections for hepatocellular carcinoma. Is it a feasible option for patients with liver cirrhosis?

BACKGROUND: Laparoscopic surgery has gained growing acceptance, but this does not hold for laparoscopic surgery of the liver, above all for patients with hepatocellular carcinoma (HCC) and cirrhosis. This approach mainly includes diagnostic procedures and interstitial therapies. However, we believe there is room for laparoscopic liver resections in well-selected cases. The aim of this study is to assess: (a) the risk of intraoperative bleeding and postoperative complications, (b) the safety and the respect of oncological criteria, and (c) the potential benefit of laparoscopic ultrasound in guiding liver resection. METHODS: A prospective study of laparoscopic liver resections for hepatocellular carcinoma was undertaken in patients with compensated cirrhosis. Hepatic involvement had to be limited and located in the left or peripheral right segments (segments 2-6), and the tumor had to be 5 cm or smaller. Tumor location and its transection margins were defined by laparoscopic ultrasound. RESULTS: From January 1997, 22 out of 250 patients with HCC (9%) underwent laparoscopic liver resections. The mean patient age was 61.4 years (range, 50-79 years). In three patients, conversion to laparotomy was necessary. The laparoscopic resections included five bisegmentectoies (2 and 3), nine segmentectomies, two subsegmentectomies and three nonanatomical resections for extrahepatic growing lesions. The mean operative time, including laparoscopic ultrasonography, was 199 +/- 69 min (median, 220; range, 80-300). Perioperative blood loss was 183 +/- 72 ml (median, 160; range, 80-400 ml). There was no mortality. Postoperative complications occurred in two out of 19 patients: an abdominal wall hematoma occurred in one patient and a bleeding from a trocar access in the other patient requiring a laparoscopic re-exploration. Mean hospital stay of the whole series was 6.5 +/- 4.3 days (median, 5; range, 4-25), while the mean hospital stay of the 19 laparoscopic patients was 5.4 +/- 1 (median, 5; range, 4-8). CONCLUSION: Laparoscopic treatment should be considered in selected patients with HCC and liver cirrhosis in the left lobe or segments 5 and 6 of the liver. It is clear that certain types of laparoscopic resection are feasible and safe when carried out by adequately skilled surgeons with appropriate instruments.

Laparoscopic radiofrequency ablation of hepatocellular carcinoma: A critical review from the surgeon's perspective.

BACKGROUND: The treatment of choice for hepatocellular carcinoma (HCC) is surgical resection but only a small percentage of patients are operative candidates. Percutaneous radiofrequency interstitial thermal ablation (RFA) has proved to be effective in the treatment of unresectable HCC. However, there is a sub-group of patients who may benefit from a laparoscopic rather than a percutaneous approach. Laparoscopic RFA offers the combined advantages of improved tumor staging based on the intracorporeal ultrasound examination and safer access to liver lesions that are difficult or impossible to treat with a percutaneous approach. The aim of our review was to evaluate the advantages and limitations of the laparoscopic approach, according to the criteria of evidence-based medicine. CONCLUSIONS: Laparoscopic RFA of HCC proved to be a safe and effective technique, at least in terms of the short- and mid-term results. This technique may be indicated in selected cases of HCC when percutaneous RFA is very difficult or contraindicated.

Technique of sentinel lymph node biopsy and lymphatic mapping during laparoscopic colon resection for cancer.

BACKGROUND: The utility of lymph node mapping to improve staging in colon cancer is still under evaluation. Laparoscopic colectomy for colon cancer has been validated in multi-centric trials. This study assessed the feasibility and technical aspects of lymph node mapping in laparoscopic colectomy for colon cancer. METHODS: A total of 42 patients with histologically proven colon cancer were studied from January 2006 to September 2007. Exclusion criteria were: advanced disease (clinical stage III), rectal cancer, previous colon resection and contraindication to laparoscopy. Lymph-nodal status was assessed preoperatively by computed tomography (CT) scan and intra-operatively with the aid of laparoscopic ultrasound. Before resection, 2-3 ml of Patent Blue V dye was injected sub-serosally around the tumour. Coloured lymph nodes were marked as sentinel (SN) with metal clips or suture and laparoscopic colectomy with lymphadenectomy completed as normal. In case of failure of the intra-operative procedure, an ex vivo SN biopsy was performed on the colectomy specimen after resection. RESULTS: A total number of 904 lymph nodes were examined, with a median number of 22 lymph nodes harvested per patient. The SN detection rate was 100%, an ex vivo lymph node mapping was necessary in four patients. Eleven (26.2%) patients had lymph-nodal metastases and in five (45.5%) of these patients, SN was the only positive lymph node. There were two (18.2%) false-negative SN. In three cases (7.1%) with aberrant lymphatic drainage, lymphadenectomy was extended. The accuracy of SN mapping was 95.2% and negative predictive value was 93.9%. CONCLUSIONS: Laparoscopic lymphatic mapping and SN removal is feasible in laparoscopic colectomy for colon cancer. The ex vivo technique is useful as a salvage technique in case of failure of the intra-operative procedure. Prospective studies are justified to determine the real accuracy and false-negative rate of the technique.

Salvage hepatic resection after incomplete interstitial therapy for primary and secondary liver tumours.

BACKGROUND: When the response to percutaneous ablation therapy (PAT) of liver tumours is incomplete, surgery may be undertaken as a salvage therapy. To validate the safety and effectiveness of salvage hepatectomy, patients who had undergone PAT or no treatment before hepatectomy were compared. METHODS: Of 137 patients who had hepatectomy for primary and secondary tumours, 21 had undergone PAT and 116 had surgery as primary treatment. Tumour features and the incidence of liver cirrhosis were similar in the two groups. RESULTS: Peroperative mortality and major morbidity rates were zero and 5 per cent (one of 21) respectively among patients who had PAT before surgery, and 0.9 per cent (one of 116) and zero in those who did not. Duration of operation (mean 495 versus 336 min; P<0.001), clamping time (mean 81 versus 53 min; P<0.001), blood loss (mean 519 versus 286 ml; P=0.004), need for blood transfusion (six of 21 patients versus nine of 116; P=0.001), and rates of thoracophrenolaparotomy (eight of 21 versus 14 of 116; P<0.001) and resection of other tissues (six of 21 versus nine of 116; P<0.001) were significantly higher in the PAT group. CONCLUSION: Hepatectomy after incomplete PAT is safe and effective, but more extensive procedures are necessary. The effect of salvage hepatectomy on long-term outcome is still unclear.

Impact of intraoperative ultrasonography in laparoscopic liver surgery.

BACKGROUND: Laparoscopic surgery has gained growing acceptance, but this does not hold for laparoscopic surgery of the liver. This mainly includes diagnostic procedures, interstitial therapies, and treatment of liver cysts. However, the authors believe there is room for a laparoscopic approach to the liver in selected cases. METHODS: A prospective study of laparoscopic liver resections was undertaken with patients who had preoperative diagnoses of benign lesion and hepatocellular carcinoma with compensated cirrhosis. The inclusion criteria required that hepatic involvement be limited and located in the left or peripheral right segments (segments 2-6), and that the tumor be 5 cm or smaller. The location of the tumor and its transection margin were defined by laparoscopic ultrasound (LUS). RESULTS: From December 1996, 17 (5%) of 313 liver resections were included in the study. There were 5 benign lesions and 12 hepatocellular carcinomas in cirrhotic patients. The mean age of the study patients was 59 years (range, 29-79 years). The LUS evaluation identified the presence of new hepatocellular carcinoma nodules in two patients (17%). The resections included 1 bisegmentectomy, 8 segmentectomies, 3 subsegmentectomies, and 3 nonanatomic resections. The mean operative time, including laparoscopic ultrasonography, was 156 +/- 50 min (median, 150 min; range, 60-250 min), and the perioperative blood loss was 190 +/- 97 ml. There was no mortality. Conversion to laparotomy was necessary for two patients. Postoperative complications were experienced by 3 of 15 patients, all of them cirrhotics. One of the patients had a wall hematoma, and the remaining two patients had bleeding from a trocar access requiring a laparoscopic reexploration. The mean hospital stay for the whole series was 6.9 +/- 4.9 days (median, 6 days; range, 2-25 days) and 5.6 +/-1.4 days (median, 6 days; range, 2-8 days) for the 15 laparoscopic patients. CONCLUSION: Laparoscopic treatment should be considered for selected patients with benign and malignant lesions in the left lobe or frontal segments of the liver. Evaluation by LUS is indispensable to guarantee precise determination of the segmental tumor location and the relationship of the tumor to adjacent vascular or biliary structures, excluding adjacent or adjunctive new lesions. The evolution of laparoscopic hepatectomies probably will depend on the development of new techniques and instrumentations.