Manel Armengol

BRAF screening as a low-cost effective strategy for simplifying HNPCC genetic testing

Background: According to the international criteria for hereditary non-polyposis colorectal cancer (HNPCC) diagnostics, cancer patients with a family history or early onset of colorectal tumours showing high microsatellite instability (MSI-H) should receive genetic counselling and be offered testing for germline mutations in DNA repair genes, mainly MLH1 and MSH2. Recently, an oncogenic V600E hotspot mutation within BRAF, a kinase encoding gene from the RAS/RAF/MAPK pathway, has been found to be associated with sporadic MSI-H colon cancer, but its association with HNPCC remains to be further clarified. Methods: BRAF-V600E mutations were analysed by automatic sequencing in colorectal cancers from 206 sporadic cases with MSI-H and 111 HNPCC cases with known germline mutations in MLH1 and MSH2. In addition, 45 HNPCC cases showing abnormal immunostaining for MSH2 were also analysed. Results: The BRAF-V600E hotspot mutation was found in 40% (82/206) of the sporadic MSI-H tumours analysed but in none of the 111 tested HNPCC tumours or in the 45 cases showing abnormal MSH2 immunostaining. Conclusions: Detection of the V600E mutation in a colorectal MSI-H tumour argues against the presence of a germline mutation in either the MLH1 or MSH2 gene. Therefore, screening of these mismatch repair (MMR) genes can be avoided in cases positive for V600E if no other significant evidence, such as fulfilment of the strict Amsterdam criteria, suggests MMR associated HNPCC. In this context, mutation analysis of the BRAF hotspot is a reliable, fast, and low cost strategy which simplifies genetic testing for HNPCC.

The Initial Learning Curve for Robot-Assisted Sleeve Gastrectomy: A Surgeon's Experience While Introducing the Robotic Technology in a Bariatric Surgery Department.

Objective. Robot-assisted sleeve gastrectomy has the potential to treat patients with obesity and its comorbidities. To evaluate the learning curve for this procedure before undergoing Roux en-Y gastric bypass is the objective of this paper. Materials and Methods. Robot-assisted sleeve gastrectomy was attempted in 32 consecutive patients. A survey was performed in order to identify performance variables during completion of the learning curve. Total operative time (OT), docking time (DT), complications, and length of hospital stay were compared among patients divided into two cohorts according to the surgical experience. Scattergrams and continuous curves were plotted to develop a robotic sleeve gastrectomy learning curve. Results. Overall OT time decreased from 89.8 minutes in cohort 1 to 70.1 minutes in cohort 2, with less than 5% change in OT after case 19. Time from incision to docking decreased from 9.5 minutes in cohort 1 to 7.6 minutes in cohort 2. The time required to dock the robotic system also decreased. The complication rate was the same in the two cohorts. Conclusion. Our survey indicates that technique and outcomes for robot-assisted sleeve gastrectomy gradually improve with experience. We found that the learning curve for performing a sleeve gastrectomy using the da Vinci system is completed after about 20 cases.

Prognostic Significance of Vascular Endothelial Growth Factor and Cyclooxygenase-2 in Patients with Rectal Cancer Treated with Preoperative Radiotherapy

Purpose: To analyze the prognostic value of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in patients with locally advanced rectal cancer treated with preoperative radiotherapy. Methods: Eighty-one patients with locally advanced rectal cancer were studied. All patients received preoperative pelvic radiotherapy. Forty-seven patients received concomitant chemotherapy. Surgical resection was performed 4–8 weeks later in all patients. Immunohistochemical examination of COX-2 and VEGF was performed on the preirradiation diagnostic biopsies. An immunohistochemical score established from the extension and intensity of the markers was used for analysis. The log-rank test and proportional hazards regression analysis were used to calculate the probability that the biomarkers were associated with patient outcome. Results: COX-2 expression was positive in 38 tumors (51%) while VEGF expression was positive in 43 (57%). The only clinicopathological parameter significantly associated with COX-2 or VEGF expression was performance status. None of the 2 markers were found to predict treatment response. There was no statistically significant correlation between COX-2 and VEGF. Univariate analysis identified pathological stage (pT, pN) as prognostic for disease-free survival. When VEGF expression was analyzed, disease-free survival was reduced among patients with VEGF-positive tumors (p = 0.047). This was specifically related to metastases-free survival (p = 0.016). These results were not observed for COX-2. After multivariate analysis, the pT and pN stage remained as independent prognostic factors. Conclusions: VEGF-positive expression is an indicator of poor disease-free survival, specifically linked to distant metastasis. More aggressive treatment strategies are warranted in pT3–4 and pN1–2 rectal cancer patients.

Tumour selection advantage of non‐dominant negative P53 mutations in homozygotic MDM2‐SNP309 colorectal cancer cells

Background: Mdm2 is a natural inhibitor of p53 function and its overexpression impairs p53 transcriptional activity. T→G single-nucleotide polymorphism at position 309 (SNP309) of mdm2 induces overexpression of mdm2, but inhibits p53. Objectives: To determine whether SNP309 is a risk-modifier polymorphism in colorectal cancer (CRC) and whether tumour selection of P53 mutations are influenced by SNP309. Methods: Single-stranded conformation polymorphism and automatic sequencing were performed. Results: SNP309 is not associated with the risk of CRC or recurrence of tumours. These data do not over-ride the tumour-selection capabilities of P53 mutations in CRC. However, a significant association with non-dominant-negative P53 mutations (p = 0.02) was found. Conclusions:MDM2-SNP309 favours tumour selection of non-dominant negative P53 mutations in CRC, which also show an earlier age of tumour onset.

MMPs/TIMPs and inflammatory signalling de-regulation in human incisional hernia tissues.

Background: Incisional hernia is a common and important complication of laparotomies. Epidemiological studies allude to an underlying biological cause, at least in a subset of population. Interest has mainly focused on abnormal collagen metabolism. However, the role played by other determinants of extracellular matrix (ECM) composition is unknown. To date, there are few laboratory studies investigating the importance of biological factors contributing to incisional hernia development. We performed a descriptive tissue‐based analysis to elucidate the possible relevance of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in association with local cytokine induction in human incisional hernia tissues. The expression profiles of MMPs, TIMPs and pro‐inflammatory cytokine signalling were investigated in aponeurosis and skeletal muscle specimens taken intraoperatively from incisional hernia (n= 10) and control (n= 10) patients. Semiquantitative RT‐PCR, zymography and immunoblotting analyses were done. Incisional hernia samples displayed alterations in the microstructure and loss of ECM, as assessed by histological analyses. Moreover, incisional hernia tissues showed increased MMP/TIMP ratios and de‐regulated inflammatory signalling (tumor necrosis factor [TNFA] and interleukin [IL]‐6 tended to increase, whereas aponeurosis TNFA receptors decreased). The changes were tissue‐specific and were detectable at the mRNA and/or protein level. Statistical analyses showed several associations between individual MMPs, TIMPs, interstitial collagens and inflammatory markers. The increment of MMPs in the absence of a counterbalance by TIMPs, together with an ongoing de‐regulated inflammatory signalling, may contribute in inducing a functional defect of the ECM network by post‐translational mechanisms, which may trigger abdominal wall tissue loss and eventual rupture. The notable TIMP3 protein down‐regulation in incisional hernia fascia may be of pathophysiological significance. We conclude that this study may help to pinpoint novel hypotheses of pathogenesis that can lead to a better understanding of the disease and ultimately to improvement in current therapeutic approaches.

Right-sided diaphragmatic rupture after blunt trauma. An unusual entity

Traumatic injuries of the diaphragm remain an entity of difficult diagnosis despite having been recognised early in the history of surgery, especially when it comes to blunt trauma and injuries of the right diaphragm. We report the case of a patient with blunt trauma with right diaphragmatic rupture that required urgent surgical treatment for hepatothorax and iatrogenic severe liver injury. Blunt trauma can cause substantial diaphragmatic rupture. It must have a high index of suspicion for diaphragmatic injury in patients, victims of vehicle collisions, mainly if they have suffered frontal impacts and/or side precipitates in patients with severe thoracoabdominal trauma. The diagnosis can be performed clinically and confirmation should be radiological. The general measures for the management of multiple trauma patients must be applied. Surgery at the time of diagnosis should restore continuity.

Robotically Assisted Single Anastomosis Duodenoileal Bypass after Previous Sleeve Gastrectomy Implementing High Valuable Technology for Complex Procedures.

Staged bariatric procedures in high risk patients are a common used strategy for morbid obese patients nowadays. After previous sleeve gastrectomy, surgical treatments in order to complete weight loss or comorbidities improvements or resolutions are possible. One strategy is to perform a novel technique named SADI (single anastomosis duodenoileal bypass-sleeve). We present the technique for totally intracorporeal robotically assisted SADI using five ports and a liver retractor. We aim to see if the robotic technology offers more advantageous anastomosis and dissection obtained by the robotic approach in comparison to standard laparoscopy. The safety, feasibility, and reproducibility of a minimally invasive robotic surgical approach to complex abdominal operations such as SADI are discussed.

Apoptosis-Like Cell Death Induction and Aberrant Fibroblast Properties in Human Incisional Hernia Fascia

Incisional hernia often occurs following laparotomy and can be a source of serious problems. Although there is evidence that a biological cause may underlie its development, the mechanistic link between the local tissue microenvironment and tissue rupture is lacking. In this study, we used matched tissue-based and in vitro primary cell culture systems to examine the possible involvement of fascia fibroblasts in incisional hernia pathogenesis. Fascia biopsies were collected at surgery from incisional hernia patients and non-incisional hernia controls. Tissue samples were analyzed by histology and immunoblotting methods. Fascia primary fibroblast cultures were assessed at morphological, ultrastructural, and functional levels. We document tissue and fibroblast loss coupled to caspase-3 activation and induction of apoptosis-like cell-death mechanisms in incisional hernia fascia. Alterations in cytoskeleton organization and solubility were also observed. Incisional hernia fibroblasts showed a consistent phenotype throughout early passages in vitro, which was characterized by significantly enhanced cell proliferation and migration, reduced adhesion, and altered cytoskeleton properties, as compared to non-incisional hernia fibroblasts. Moreover, incisional hernia fibroblasts displayed morphological and ultrastructural alterations compatible with autophagic processes or lysosomal dysfunction, together with enhanced sensitivity to proapoptotic challenges. Overall, these data suggest an ongoing complex interplay of cell death induction, aberrant fibroblast function, and tissue loss in incisional hernia fascia, which may significantly contribute to altered matrix maintenance and tissue rupture in vivo.

Internet of Things and bariatric surgery follow-up: Comparative study of standard and IoT follow-up

Abstract Introduction: Follow-up of obese patient is difficult. There is no literature related to patient follow-up that incorporates the concept of Internet of Things (IoT), use of WiFi, Internet, or portable devices for this purpose. Material and methods: This prospective observational study commenced in June 2011. Patients were prospectively offered to participate in the IoT study group, in which they received a WiFi scale (Withing®, Paris) that provides instant WiFi data to the patient and surgeon. Other patients were admitted to the standard follow-up group at the outpatient clinic. A total of 33 patients were included in our study (ten in the IoT group). Results: Twelve patients did not have WiFi at home, ten lacked of computer knowledge, and seven preferred standard for follow-up. All patients underwent different surgical procedures. There were no complications. Excess weight loss (EWL) was similar in both groups. More than 90% of patients were satisfied. In the IoT group, patients considered it valuable in saving time, and considered seeing their evolution graphics extremely motivating. Conclusion: IoT technology can monitor medical parameters remotely and collect data. A WiFi scale can facilitate preoperative and follow-up. Standard follow-up in a classical outpatient clinic setting with the surgeon was preferred globally.

Postthyroidectomy Horner's Syndrome.

Horners syndrome (HSd) results from an injury along the cervical sympathetic chain, producing ipsilateral miosis, ptosis, enophthalmos, and facial anhydrosis. Although more commonly associated to malignant tumors affecting the preganglionar segment of the sympathetic chain (especially in the lung apex), HSd has been described as a rare complication of thyroid surgery. We herein report a case of HSd after completing total thyroidectomy.