L. Schwarz

Is the image "right" for everyone? Introduction to the parallax effect in laparoscopic surgery.

AIM OF THE STUDYnDuring minimally invasive abdominal surgery, a laparoscope is used to film the procedure, which is transmitted to a flat screen monitor. The horizontality of the image depends on the orientation in space and the visual comfort of the surgeon. Observing the screen via a lateral angle of incidence frequently results in the camera assistant making errors in determining the horizontality of the image. Thus, what is right for the camera assistant is not necessarily right for the surgeon. We aimed to explain the impact of these errors in laparoscope manipulation, by the description of the parallax effect.nnnPATIENTS AND METHODSnTo describe this phenomenon of perceptions changing depending on the angle of view, from the basis of the parallax effect, we observed the change of position and for two observers, (the surgeon and the camera assistant) seated at two different locations, using an experimental set up (i.e., photography equipment, a screen and a pelvitrainer).nnnRESULTSnThe position of the camera assistant positioned at an angle of incidence of 45° from the surgeon, the observation of the screen with a lateral incidence changes the perception of the image viewed on the screen. For correcting the conflict between the subjective visual perception of the camera assistant and the actual image horizon, the camera assistant instinctively rotates the image, which can lead to an incorrect image, deleterious for the surgeon.nnnCONCLUSIONSnThis article introduces a previously unexplained concept in medical literature, called the parallax effect. The parallax effect results in the camera assistant making systematic errors in determining image horizontality on the screen.

Resectable pancreatic adenocarcinoma neo-adjuvant FOLF(IRIN)OX-based chemotherapy - a multicenter, non-comparative, randomized, phase II trial (PANACHE01-PRODIGE48 study)

BackgroundAt time of diagnosis, less than 10% of patients with pancreatic adenocarcinomas (PDAC) are considered to be immediately operable (i.e. resectable). Considering their poor overall survival (OS), only tumours without vascular invasion (NCCN 2017) should be considered for resection, i.e. those for which resection with disease-free margins (R0) is theoretically possible in absence of presurgery treatment. With regard to high R1 rates and undetectable locoregional and/or metastatic spreading prior to surgery explain (at least in part) the observed 1-year relapse and mortality rates of 50 and 25%, respectively. Today, upfront surgery followed by adjuvant chemotherapy is the reference treatment in Europe. The main limitation of the adjuvant approach is the low rate of completion of the full therapeutic sequence. Indeed, only 47 to 60% patients received any adjuvant therapy after resection compared to more than 75% for neoadjuvant therapy. No previous prospective study has compared this approach to a neoadjuvant FOLFIRINOX or FOLFOX chemotherapy for resectable PDAC.MethodsPANACHE01-PRODIGE48 is a prospective multicentre controlled randomized non comparative Phase II trial, evaluating the safety and efficacy of two regimens of neo-adjuvant chemotherapy (4xa0cycles of mFOLFIRINOX or FOLFOX) relative to the current reference treatment (surgery and then adjuvant chemotherapy) in patients with resectable PDAC. The main co-primary endpoints are OS rate at 12xa0months and the rate of patients undergoing the full therapeutic sequence.DiscussionThe “ideal” cancer treatment for resectable PDAC would have the following characteristics: administration to the highest possible proportion of patients, ability to identify fast-progressing patients (i.e. poor candidates for surgery), a low rate of R1 resections (through optimisation of local disease control), and an acceptable toxicity profile. The neoadjuvant approach may meet all these criteria. With respect to published data on the efficacy of FOLFOX and mFOLFIRINOX, these two regimens are potential candidates for neoadjuvant use in the aim to optimising oncological outcomes in resectable PDAC.Trial registrationClinicalTrials.gov, NCT02959879. Trial registration date: November 9, 2016.

Does Intraoperative Systematic Bacterial Sampling During Complete Cytoreductive Surgery (CRS) with Hyperthermic Intraoperative Peritoneal Chemotherapy (HIPEC) Influence Postoperative Treatment? A New Predictive Factor for Postoperative Abdominal Infectious Complications

BackgroundCytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is an emerging curative treatment option for patients with peritoneal carcinomatosis. It has a long-term survival benefit but is associated with high rates of morbidity, ranging from 12xa0% to 65xa0%, mainly due to infectious complications. We sought to evaluate the clinical relevance of routine intraoperative bacteriological sampling following CRS/HIPEC.Study designBetween November 2010 and December 2014, every patients receiving CRS/HIPEC were included. Three samples were routinely collected from standardized locations for intraperitoneal rinsing liquid bacteriological analysis (RLBA) after completion of HIPEC. The clinical and surgical features, bacteriological results, and short-term outcomes were retrospectively reviewed.ResultsThe overall mortality and morbidity rates were 5 and 45xa0%, respectively. Among the 75 included patients, 40xa0% (nxa0=xa030) had at least one positive bacterial culture. Risk factors for a positive culture were colorectal resection (adjusted hazard ratio [HR]xa0=xa03.072, 95xa0% CI 1.843–8.004; pxa0=xa00.009) and blood loss >1000xa0mL (HRxa0=xa04.272, 95xa0% CI 1.080–18.141; pxa0=xa00.031). Among 26 (35xa0%) patients with abdominal infectious complications, 13 (17xa0%) experienced isolated complications. A positive RLBA result was independently associated with abdominal infectious complications (HRxa0=xa05.108, 95xa0% CI 1.220–16.336; pxa0=xa00.024) and isolated abdominal infectious complications (HRxa0=xa04.199, 95xa0% CI 1.064–15.961; pxa0=xa00.04).ConclusionsForty percent of the RLBA samples obtained following CRS/HIPEC tested positive for bacteria. Bacterial sampling of rinsing liquid should be systematically performed. An aggressive and immediate antibiotic strategy needs to be evaluated.

Difficult hemostasis during radical pelvic surgery

Bleeding that arises during pelvic surgery can be difficult to control and potentially lethal. We describe here the different methods for managing hemorrhage that arises during radical pelvic surgery (exenteration) and during extensive resections (resection of the sacrum or the lateral surfaces of the pelvis). The techniques to deal with complications of radical surgery require a prolonged apprenticeship and experience in radical extirpative surgery, as well as certain flexibility and adaptability since a given intervention is rarely identical to preceding cases. The principal techniques that can be performed [1—3] as well as different modes of reconstruction [4,5] have been described in numerous previous issues of the Journal of Visceral Surgery. Decision-making and ingenuity are often necessary to accomplish a complete resection with tumor-free margins of pelvic malignancies. The procedure is seldom stereotypical. The surgeon must be aware of the numerous concerns that may arise in the few minutes before resection of the tumoral mass. The last phases of the resection are often performed on the underside of the mass with reduced visibility. The surgeon must be prudent to avoid injury to critical structures as the resection nears completion. When abnormal bleeding without any evident explanation develops in the early stages of resection by laparotomy, the surgeon’s first concern is to verify the position of the retractors. Vena caval compression by the retractors may impede venous return resulting in bleeding due to backpressure in the pelvic veins. Coagulation parameters should also be verified. When venous bleeding occurs, optimal management demands a methodical approach. Bleeding may arise from the pre-sacral venous plexus, or from branches of the internal iliac vein. It is important to remain calm and to control the bleeding with compression or tamponnade by packing. Once the bleeding is under temporary control, one can ask for the participation of an additional surgeon, optimize esposure and illumination of the surgical field and of suction apparatus, enlarge the incision if necessary, or bring additional retractors into play. The anesthesiology team should be informed of the anticipated bleeding so that necessary replacement blood products are readily available in the operating room. Often, compression applied for ten minutes or more may be sufficient to reduce or arrest the bleeding.

Les critères de résécabilité des adénocarcinomes pancréatiques en 2014

La chirurgie d’exerese pancreatique pour adenocarcinome est le seul traitement a visee curative avec des medianes de survie pour les tumeurs dites resecables superieures a 20 mois apres traitement adjuvant.Pour guider les indications operatoires, des criteres de resecabilite ont ete definis, mais la litterature et les donnees publiees sont heterogenes, et parfois difficiles a analyser. Trois groupes (MD Anderson Cancer Center (MDACC), American Hepato Pancreato Biliary Assocation (AHPBA), National Comprehensive Cancer Network (NCCN)) ont etabli des classifications ayant pour objectif de distinguer les tumeurs resecables des tumeurs localement avancees, separees en 2 stades dits « borderline » correspondant a une resecabilite limite et « localement avance » non resecable. Ces classifications reposent sur une analyse scannographique standardisee, ayant fait l’objet de recommandations des societes savantes americaines debut 2014.Bien que tres informatives, ces classifications ne doivent pas etre utilisees de maniere isolee et les donnees cliniques et biologiques sont a prendre en consideration dans la decision therapeutique.Les progres recents en termes de chimiotherapie (polychimiotherapie de type FOLFIRINOX, ou nab-paclitaxel) permettent d’envisager, chez les malades dont la tumeur est initialement non resecable, une prise en charge sequentielle, associant un traitement, d’induction avec reevaluation de la resecabilite suivie d’une chirurgie secondaire.L’evaluation de la resecabilite est actuellement le point-cle orientant la prise en charge oncologique selon le stade tumoral.

Le cancer du rectum en situation de recours

One of the objectives of the French strategic plan for cancer 2009-2013 is to structure the need for referral surgery, particularly for low rectal carcinoma. However, low rectal cancer is not the only situation in the field of rectal surgery where expert unit are needed for the referral of appropriate patients. We developed the multidisciplinary strategies for low rectal cancer, advanced rectal cancer, recurrent rectal cancer and peritoneal carcinomatosis. Optimal management of these difficult situations can give a chance of long term survival while a non-optimal management could jeopardise the future of patients by changing a potentially curable disease into an incurable one.