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Dive into the research topics where Pierre Allemann is active.

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Featured researches published by Pierre Allemann.


British Journal of Surgery | 2010

Critical appraisal of single port access cholecystectomy.

Pierre Allemann; Markus Schäfer; Nicolas Demartines

Single port access (SPA) cholecystectomy is a new concept in laparoscopic surgery. A review of existing results was performed to evaluate critically the current state of SPA with specific reference to feasibility, safety, learning curve, indications and cost‐effectiveness.


British Journal of Surgery | 2009

Transgastric hybrid cholecystectomy

B. Dallemagne; S. Perretta; Pierre Allemann; Mitsuhiro Asakuma; Jacques Marescaux

Clinical application of natural orifice transluminal endoscopic surgery is under investigation. Preliminary results of transvaginal cholecystectomy in women and associated technical issues have been described. The technique and initial results of hybrid transgastric cholecystectomy are now reported.


World Journal of Gastroenterology | 2014

Remains of the day: biliary complications related to single-port laparoscopic cholecystectomy.

Pierre Allemann; Nicolas Demartines; Markus Schäfer

AIM To assess the rate of bile duct injuries (BDI) and overall biliary complications during single-port laparoscopic cholecystectomy (SPLC) compared to conventional laparoscopic cholecystectomy (CLC). METHODS SPLC has recently been proposed as an innovative surgical approach for gallbladder surgery. So far, its safety with respect to bile duct injuries has not been specifically evaluated. A systematic review of the literature published between January 1990 and November 2012 was performed. Randomized controlled trials (RCT) comparing SPLC versus CLC reporting BDI rate and overall biliary complications were included. The quality of RCT was assessed using the Jadad score. Analysis was made by performing a meta-analysis, using Review Manager 5.2. This study was based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. A retrospective study including all retrospective reports on SPLC was also performed alongside. RESULTS From 496 publications, 11 RCT including 898 patients were selected for meta-analysis. No studies were rated as high quality (Jadad score ≥ 4). Operative indications included benign gallbladder disease operated in an elective setting in all studies, excluding all emergency cases and acute cholecystitis. The median follow-up was 1 mo (range 0.03-18 mo). The incidence of BDI was 0.4% for SPLC and 0% for CLC; the difference was not statistically different (P = 0.36). The incidence of overall biliary complication was 1.6% for SPLC and 0.5% for CLC, the difference did not reached statistically significance (P = 0.21, 95%CI: 0.66-15). Sixty non-randomized trials including 3599 patients were also analysed. The incidence of BDI reported then was 0.7%. CONCLUSION The safety of SPLC cannot be assumed, based on the current evidence. Hence, this new technology cannot be recommended as standard technique for laparoscopic cholecystectomy.


Surgery for Obesity and Related Diseases | 2016

Laparoscopic Roux-en-Y gastric bypass for failed gastric banding: outcomes in 642 patients.

Pierre Fournier; Daniel Gero; Anna Dayer-Jankechova; Pierre Allemann; Nicolas Demartines; Jean-Pierre Marmuse; Michel Suter

BACKGROUND Laparoscopic adjustable gastric banding (LAGB) is a well-tolerated procedure but has high long-term complication and failure rates. Laparoscopic conversion to Roux-en-Y gastric bypass (LRYGB) is one of the rescue strategies. OBJECTIVES To analyze short- and long-term results of reoperative LRYGB after failed LAGB. SETTING Three European expert bariatric center (2 university hospitals and 1 regional hospital). METHODS A retrospective review of prospectively collected data, including all consecutive patients submitted to revisional LRYGB for failed LAGB between 1999 and 2013, was performed. Complications were classified according to the Dindo-Clavien system. Long-term results in terms of weight loss were analyzed in a subgroup of patients. RESULTS A total of 642 patients (569 women and 73 men) were included. Mean±standard deviation operating time was 188±43 minutes. There was no mortality and an overall complication rate of 9.7%, including 3.6% major complications, with no difference between the 1- or 2-step approaches. Follow-up rate was 88% at 10 years for the Swiss patient cohort. The mean excess body mass index loss was between 65% and 70% throughout the study period, and the mean total weight loss was between 28% and 30% based on the maximum weight. The mean body mass index decreased from 44.7 kg/m(2) before LAGB to 31.6, 32.2, and 32.5 kg/m(2) at 1, 5, and 10 years after revision. CONCLUSIONS Revisional LRYGB is well tolerated and feasible after failed LAGB. A 1-step approach, in cases without erosion, does not increase operative morbidity. Results up to 10 years after revision are comparable to those reported after primary LRYGB.


Digestive Surgery | 2016

Effect of Antecolic versus Retrocolic Gastroenteric Reconstruction after Pancreaticoduodenectomy on Delayed Gastric Emptying: A Meta-Analysis of Six Randomized Controlled Trials

Gaëtan-Romain Joliat; Ismail Labgaa; Nicolas Demartines; Markus Schäfer; Pierre Allemann

Background: One of the most frequent complications of pancreaticoduodenectomy (PD) is delayed gastric emptying (DGE). The study aim was to evaluate the impact of the type of gastro/duodenojejunal reconstruction (antecolic vs. retrocolic) after PD on DGE incidence. Methods: A systematic review was made according to the PRISMA guidelines. Randomized controlled trials (RCTs) comparing antecolic vs. retrocolic reconstruction were included irrespective of the PD techniques. A meta-analysis was then performed. Results: Six RCTs were included for a total of 588 patients. The overall quality was good. General risk of bias was low. DGE was not statistically significantly different between the antecolic and retrocolic group (OR 0.6, 95% CI 0.31-1.16, p = 0.13). The other main surgery-related complications (pancreatic fistula, hemorrhage, intra-abdominal abscess, bile leak and wound infection) were not dependent on the reconstruction route (OR 0.84, 95% CI 0.41-1.70, p = 0.63). No statistically significant difference in terms of length of hospital stay was found between the 2 groups. There was also no difference of DGE incidence if only pylorus-preserving PD was considered and between the DGE grades A, B or C. Conclusion: This meta-analysis shows that antecolic reconstruction after PD is not superior to retrocolic reconstruction in terms of DGE.


World Journal of Emergency Surgery | 2014

Giant extra-hepatic thrombosed portal vein aneurysm: a case report and review of the literature

Ismail Labgaa; Yann Lachenal; Pierre Allemann; Nicolas Demartines; Markus Schäfer

BackgroundExtrahepatic Portal vein aneurysm (EPVA) is a rare finding that may be associated with different complications, e.g. thrombosis, rupture, portal hypertension and compression of adjacent structures. It is being diagnosed more frequently with the advent of modern cross-sectional imaging. Our review of the English literature disclosed 13 cases of thrombosed EPVA.Case presentationA 50-years-old woman presented with acute abdominal pain but no other symptom. She had no relevant medical history. Palpation of the right upper quadrant showed tenderness. Laboratory tests were unremarkable. A computed tomography showed portal vein aneurysm measuring 88 × 65 mm with thrombosis extending to the superior mesenteric and splenic vein. The patient was treated conservatively with anticoagulation therapy. She was released after two weeks and followed on an outpatient basis. At two months, she reported decreased abdominal pain and her physical examination was normal. A computed tomography was performed showing a decreased thrombosis size and extent, measuring 80 × 55 mm.ConclusionsAlthough rare, surgeons should be made aware of this entity. Complications are various. Conservative therapy should be chosen in first intent in most cases. We reported the case of the second largest thrombosed extra-hepatic PVA described in the literature, treated by anticoagulation therapy with a good clinical and radiological response.


Journal of Surgical Oncology | 2017

Sterilization of tumor-positive lymph nodes of esophageal cancer by neo-adjuvant treatment is associated with worse survival compared to tumor-negative lymph nodes treated with surgery first

Styliani Mantziari; Pierre Allemann; Michael Winiker; Christine Sempoux; Nicolas Demartines; Markus Schäfer

Lymph node (LN) involvement by esophageal cancer is associated with compromised long‐term prognosis. This study assessed whether LN downstaging by neoadjuvant treatment (NAT) might offer a survival benefit compared to patients with a priori negative LN.


World Journal of Surgery | 2018

Assessment of Avoidable Readmissions in a Visceral Surgery Department with an Algorithm: Methodology, Analysis and Measures for Improvement

Fabio Agri; Anne-Claude Griesser; Estelle Lécureux; Pierre Allemann; Markus Schäfer; Yves Eggli; Nicolas Demartines

BackgroundStandardized quality indicators assessing avoidable readmission become increasingly important in health care. They can identify improvements area and contribute to enhance the care delivered. However, the way of using them in practice was rarely described.MethodsRetrospective study uses prospective inpatients’ information. Thirty-day readmissions were deemed potentially avoidable or non-avoidable by a computerized algorithm, and annual rate was reported between 2010 and 2014. Observed rate was compared to expected rate, and medical record review of potentially avoidable readmissions was conducted on data between January and June 2014.ResultsDuring a period of ten semesters, 11,011 stays were screened by the algorithm and a potentially avoidable readmission rate (PAR) of 7% was measured. Despite stable expected rate of 5 ± 0.5%, an increase was noted concerning the observed rate since 2012, with a highest value of 9.4% during the first semester 2014. Medical chart review assessed the 109 patients screened positive for PAR during this period and measured a real rate of 7.8%. The delta was in part due to an underestimated case mix owing to sub-coded comorbidities and not to health care issue.ConclusionsThe present study suggests a methodology for practical use of data, allowing a validated quality of care indicator. The trend of the observed PAR rate showed a clear increase, while the expected PAR rate was stable. The analysis emphasized the importance of adequate “coding chain” when such an algorithm is applied. Moreover, additional medical chart review is needed when results deviate from the norm.


Diseases of The Esophagus | 2018

Accuracy of preoperative staging for a priori resectable esophageal cancer

Michael Winiker; Styliani Mantziari; S G Figueiredo; Nicolas Demartines; Pierre Allemann; Markus Schäfer

This study assessed the accuracy of preoperative staging in patients undergoing oncological esophagectomy for adenocarcinoma and squamous cell carcinoma. All patients undergoing surgery for resectable esophageal cancer in a university hospital from 2005 to 2016 were identified from our institutional database. Patients with neoadjuvant treatment were excluded to avoid bias from down-staging effects. Routinely, all patients had an upper endoscopy with biopsy, a thoracoabdominal CT scan, an 18-FEG PET-CT, and endoscopic ultrasound. Preoperative staging was compared to histopathological staging of surgical specimen that was considered as gold standard. There were 51 patients with a median age of 65 years (IQR: 59.3-73 years) having 21 squamous cell carcinoma and 30 adenocarcinoma, respectively. T- and N-stages were correctly predicted in 26 (51%) and 37 patients (72%), respectively. Overall, 18 patients (35%) were preoperatively diagnosed with a correct T- and N-stage. There was no difference between adenocarcinoma and squamous cell carcinoma. Accuracy of the T-stage was not influenced by the smoking status. The N-stage was not correct in 7/22 smoking patients (32%) and 6/29 nonsmoking patients (21%).The N-stage was underestimated in smoking patients as 6/22 patients (27%) had a histologically confirmed N+ who were preoperatively classified as N0. In conclusion, only 35% of patients had a correct assessment. Separate T- and N-stage prediction was improved with 51% and 72%, respectively. Major efforts are needed for improvement.


Journal de Chirurgie Viscérale | 2015

Le rapport plaquettes/leucocytes (RPL) avant traitement néo-adjuvant des patients atteints d’un cancer de l’œsophage a-t il une valeur prédictive clinique ?

Styliani Mantziari; Michael Winiker; Sergio Gaspar Figuereido; Pierre Allemann; Nicolas Demartines; Markus Schäfer

Introduction Les rapports plaquettes/lymphocytes et neutrophiles/ lymphocytes ont ete etudies comme parametres representatifs de la reponse inflammatoire systemique chez les patients oncologiques. Notre etude visa a evaluer le rapport plaquettes/leucocytes (RPL) pour le cancer de l’œsophage, et d’analyser la correlation avec la reponse histologique au traitement neoadjuvant (NAT) selon Mandard, les complications majeures postoperatoires et la survie globale. Methode Tous les patients operes d’une œsogastrectomie pour cancer dans notre centre entre 2000 et 2013 ont ete etudies. Une analyse ROC a ete conduite pour estimer la valeur seuil optimale du RPL et comparer les parametres principaux entre les differents sous-groupes. Le test de Fisher et ANOVA ont ete utilises pour les valeurs categoriques et continues respectivement, avec une valeur p Resultats Nous avons analyses 132 patients avec un âge median de 64 [46-84] ans, dont 59 (44,7 %) ont eu un traitement neoadjuvant. Le RPL pretraitement n’a pas ete predictif de la survenue des complications majeures postoperatoires ni de la survie globale des patients. En revanche, un RPL>22 a ete significativement correle a une reponse histologique complete ou excellente (TRG 1-2) apres NAT. Conclusion Un RPL>22 avant traitement neoadjuvant pour le cancer de l’œsophage a ete significativement correle a une reponse histopathologique complete ou excellente. Declaration d’interet Les auteurs n’ont pas transmis de conflits d’interets.

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Markus Schäfer

University Hospital of Lausanne

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Ismail Labgaa

Icahn School of Medicine at Mount Sinai

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Gaëtan-Romain Joliat

University Hospital of Lausanne

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Pierre Edouard Fournier

Centre national de la recherche scientifique

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