P A Clavien

University of Zurich, Zürich, Zurich, Switzerland

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Publications (150)783.76 Total impact

  • Article: Reply
    Hepatology 10/2014; · 11.19 Impact Factor
  • Annals of surgery. 08/2014; 260(2):e4.
  • P. Dutkowski, P.‐A. Clavien
    British Journal of Surgery 06/2014; 101(7). · 4.84 Impact Factor
  • Source
    P.‐A. Clavien, M. A. Puhan
    British Journal of Surgery 05/2014; 101(6). · 4.84 Impact Factor
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    ABSTRACT: We describe a case of a 62-year-old diabetic woman with hepatocellular carcinoma due to chronic hepatitis B virus infection. Two weeks after orthotopic liver transplantation, endoscopy for massive upper gastrointestinal bleeding revealed a large necrotic area in the gastric fundus. The patient underwent emergency resection. Histopathologically, angioinvasive mold infection compatible with mucormycosis was diagnosed in a large area of necrosis, mimicking an atypically localized gastric ulcer. Foreign bodies originating from transarterial chemoembolization (TACE) performed 7 and 8 months earlier and 40 days before transplantation were identified in the submucosal tissue. The patient was treated with liposomal amphotericin B (LAB) for 5 weeks, followed by 7 weeks of posaconazole. Follow-up biopsies after 1 and 5 months confirmed successful treatment. Review of the radiological images of the TACE procedure showed that some of the TACE material had been diverted to the stomach via an accessory gastric branch originating from the left hepatic artery. TACE agents may be associated with chronic, refractory gastroduodenal ulcers. We hypothesize that the ischemic lesion was first colonized with presumed Mucorales mold and invasive growth was promoted by the posttransplantation immunosuppression. Careful exploration of extrahepatic collaterals during TACE may prevent this complication.
    Infection 03/2014; · 2.86 Impact Factor
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    ABSTRACT: Intraoperative adverse events significantly influence morbidity and mortality of laparoscopic colorectal resections. Over an 11-year period, the changes of occurrence of such intraoperative adverse events were assessed in this study. Analysis of 3,928 patients undergoing elective laparoscopic colorectal resection based on the prospective database of the Swiss Association of Laparoscopic and Thoracoscopic Surgery was performed. Overall, 377 intraoperative adverse events occurred in 329 patients (overall incidence of 8.4 %). Of 377 events, 163 (43 %) were surgical complications and 214 (57 %) were nonsurgical adverse events. Surgical complications were iatrogenic injury to solid organs (n = 63; incidence of 1.6 %), bleeding (n = 62; 1.6 %), lesion by puncture (n = 25; 0.6 %), and intraoperative anastomotic leakage (n = 13; 0.3 %). Of note, 11 % of intraoperative organ/puncture lesions requiring re-intervention were missed intraoperatively. Nonsurgical adverse events were problems with equipment (n = 127; 3.2 %), anesthetic problems (n = 30; 0.8 %), and various (n = 57; 1.5 %). Over time, the rate of intraoperative adverse events decreased, but not significantly. Bleeding complications significantly decreased (p = 0.015), and equipment problems increased (p = 0.036). However, the rate of adverse events requiring conversion significantly decreased with time (p < 0.001). Patients with an intraoperative adverse event had a significantly higher rate of postoperative local and general morbidity (41.2 and 32.9 % vs. 18.0 and 17.2 %, p < 0.001 and p < 0.001, respectively). Intraoperative surgical complications and adverse events in laparoscopic colorectal resections did not change significantly over time and are associated with an increased postoperative morbidity.
    Langenbeck s Archives of Surgery 01/2014; · 1.89 Impact Factor
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    ABSTRACT: Virtual reality (VR) simulators are widely used to familiarize surgical novices with laparoscopy, but VR training methods differ in efficacy. In the present trial, self-controlled basic VR training (SC-training) was tested against training based on peer-group-derived benchmarks (PGD-training). First, novice laparoscopic residents were randomized into a SC group (n = 34), and a group using PGD-benchmarks (n = 34) for basic laparoscopic training. After completing basic training, both groups performed 60 VR laparoscopic cholecystectomies for performance analysis. Primary endpoints were simulator metrics; secondary endpoints were program adherence, trainee motivation, and training efficacy. Altogether, 66 residents completed basic training, and 3,837 of 3,960 (96.8 %) cholecystectomies were available for analysis. Course adherence was good, with only two dropouts, both in the SC-group. The PGD-group spent more time and repetitions in basic training until the benchmarks were reached and subsequently showed better performance in the readout cholecystectomies: Median time (gallbladder extraction) showed significant differences of 520 s (IQR 354-738 s) in SC-training versus 390 s (IQR 278-536 s) in the PGD-group (p < 0.001) and 215 s (IQR 175-276 s) in experts, respectively. Path length of the right instrument also showed significant differences, again with the PGD-training group being more efficient. Basic VR laparoscopic training based on PGD benchmarks with external assessment is superior to SC training, resulting in higher trainee motivation and better performance in simulated laparoscopic cholecystectomies. We recommend such a basic course based on PGD benchmarks before advancing to more elaborate VR training.
    World Journal of Surgery 08/2013; · 2.35 Impact Factor
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    ABSTRACT: BACKGROUND: Perineal stapled prolapse (PSP) resection is a novel operation for treating external rectal prolapse. However, no long-term results have been reported in the literature. This study analyses the long-term recurrence rate, functional outcome, and morbidity associated with PSP resection. METHODS: Nine consecutive patients undergoing PSP resection between 2007 and 2011 were prospectively followed. Surgery was performed by the same surgeons in a standardised technique. Recurrence rate, functional outcome, and complication grade were prospectively assessed. RESULTS: All 9 patients undergoing PSP resection were investigated. The median age was 72 years (range 25-88 years). No intraoperative complications occurred. Faecal incontinence, preoperatively present in 2 patients, worsened postoperatively in one patient (Vaizey 18-22). One patient developed new-onset faecal incontinence (Vaizey 18). The median obstructive defecation syndrome score decreased postoperatively significantly from 11 (median; range 8-13) to 5 (median; range 4-8) (p < 0.005). At a median follow-up of 40 months (range 14-58 months), the prolapse recurrence rate was 44 % (4/9 patients). CONCLUSIONS: The PSP resection is a fast and safe procedure associated with low morbidity. However, the poor long-term functional outcome and the recurrence rate of 44 % warrant a cautious patient selection.
    Techniques in Coloproctology 04/2013; · 1.54 Impact Factor
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    American Journal of Transplantation 01/2013; · 6.19 Impact Factor
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    ABSTRACT: Virtual reality devices are becoming the backbone for laparoscopic training in surgery. However, without knowledge of the achievable metrics of basic training within the trainee group, these simulators cannot be used effectively. Currently, no validated task metrics of the performance of larger trainee groups are available. From April 2004 to December 2009, we collated an extensive prospective database using the Simbionix LAP Mentor (Simbionix USA, Cleveland, Ohio) for basic laparoscopic training of novice surgeons. This database was used to determine benchmarks for basic skill exercises and procedural tasks that combine stimulus to improve and feasibility with acceptance of the training program and the goal to train for safe surgery. In all, 18,996 task performances of 286 novice trainees were analyzed. For the basic skill exercises, the total time for correct execution ranged between 45 seconds for basic skill 3 (eye-hand coordination) and 269 seconds for basic skill 9 (object placement). For the procedural tasks, the total time for correct execution ranged between 68 seconds for procedural task 1 (clipping and cutting) and 256 seconds for procedural task 3 (dissection). The total time to task completion depended mainly on right instrument path length with high correlation to left instrument path length. Learning curve analyses of the 4 procedural tasks demonstrated performance plateaus after 10-15 repetitions. Most complications occurred during the initial repetitions of the respective task. The best quartile of performances was chosen as peer group benchmark because it provides sufficient stimulus for improvement without discouraging trainees, thus enhancing adherence to the training program. The benchmark for safety and accuracy parameters was set at a predefined level of 95% correct execution. As experience with virtual reality (VR) training is growing, curricula must be based on benchmarks for efficient training derived from large trainee groups to optimize use of the still costly simulators. Safety parameters should be included in trainee assessment. We share a set of metrics that take into account both performance and feasibility for basic laparoscopic training of surgical novices using the Simbionix LAP Mentor.
    Journal of Surgical Education 07/2012; 69(4):459-67. · 1.07 Impact Factor
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    ABSTRACT: AimsThrough a 4-year follow-up of the abstracts submitted to the European Society of Cardiology Congress in 2006, we aimed at identifying factors predicting high-quality research, appraising the quality of the peer review and editorial processes, and thereby revealing potential ways to improve future research, peer review, and editorial work.Methods and resultsAll abstracts submitted in 2006 were assessed for acceptance, presentation format, and average reviewer rating. Accepted and rejected studies were followed for 4 years. Multivariate regression analyses of a representative selection of 10% of all abstracts (n= 1002) were performed to identify factors predicting acceptance, subsequent publication, and citation. A total of 10 020 abstracts were submitted, 3104 (31%) were accepted for poster, and 701 (7%) for oral presentation. At Congress level, basic research, a patient number ≥ 100, and prospective study design were identified as independent predictors of acceptance. These factors differed from those predicting full-text publication, which included academic affiliation. The single parameter predicting frequent citation was study design with randomized controlled trials reaching the highest citation rates. The publication rate of accepted studies was 38%, whereas only 24% of rejected studies were published. Among published studies, those accepted at the Congress received higher citation rates than rejected ones.ConclusionsResearch of high quality was determined by study design and largely identified at Congress level through blinded peer review. The scientometric follow-up revealed a marked disparity between predictors of full-text publication and those predicting citation or acceptance at the Congress.
    European Heart Journal 06/2012; · 14.72 Impact Factor
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    ABSTRACT: Although liver transplantation is a widely accepted treatment for hepatocellular carcinoma (HCC), much controversy remains and there is no generally accepted set of guidelines. An international consensus conference was held on Dec 2-4, 2010, in Zurich, Switzerland, with the aim of reviewing current practice regarding liver transplantation in patients with HCC and to develop internationally accepted statements and guidelines. The format of the conference was based on the Danish model. 19 working groups of experts prepared evidence-based reviews according to the Oxford classification, and drafted recommendations answering 19 specific questions. An independent jury of nine members was appointed to review these submissions and make final recommendations, after debates with the experts and audience at the conference. This report presents the final 37 statements and recommendations, covering assessment of candidates for liver transplantation, criteria for listing in cirrhotic and non-cirrhotic patients, role of tumour downstaging, management of patients on the waiting list, role of living donation, and post-transplant management.
    The Lancet Oncology 10/2011; 13(1):e11-22. · 25.12 Impact Factor
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    ABSTRACT: An outcome assessment was performed of patients with unresectable colorectal liver metastases (CRLM) treated in second or third line with floxuridine (FUDR)-based hepatic artery infusion (HAI). Twenty-three patients who were pretreated with systemic (immuno)chemotherapy received FUDR-HAI alone or combined with systemic chemotherapy. We reviewed patient charts and our prospective patient database for survival and associated risk factors. Patients received FUDR-HAI for unresectable CRLM from January 2000 to September 2010. Twelve patients (52%) received concurrent systemic chemotherapy. Median overall survival (OS), progression-free survival (PFS), and hepatic PFS were 15.6 months (range, 2.5-55.7 months), 3.9 months (range, 0.7-55.7 months), and 5.5 months (range, 1.6-55.7 months), respectively. The liver resection rate after HAI was 35%. PFS was better in patients undergoing secondary resection than in patients without resection (hazard ratio [HR] 0.21; 95% confidence interval [95% CI] 0.07-0.66; P = 0.0034), while OS showed a trend toward improvement (HR 0.4; 95% CI 0.13-1.2; P = 0.09). No differences were observed in OS (P = 0.69) or PFS (P = 0.086) in patients who received FUDR-HAI alone compared with patients treated with combined regional and systemic chemotherapy. No statistically significant differences were seen in patients previously treated with one chemotherapy line compared with patients treated with two lines. Presence of extrahepatic disease was a negative risk factor for PFS (liver-only disease: HR 0.03; 95% CI 0.0032-0.28; P < 0.0001). Toxicities were manageable with dose modifications and supportive measures. FUDR-HAI improves PFS and results in a trend toward improved OS in selected patients able to undergo liver resection after tumor is downsized.
    Annals of Surgical Oncology 07/2011; 18(7):1924-31. · 3.94 Impact Factor
  • E Melloul, M Lesurtel, P A Clavien
    Revue médicale suisse 01/2011; 7(279):203-4.
  • Chapter: Pankreas
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    ABSTRACT: Das Pankreas entsteht aus einer Verschmelzung zweier Anlagen des primitiven Vorderdarms. Störungen der regelhaften Organogenese erklären Pancreas anulare und divisum sowie den Ductus pancreaticus accessorius. Die retroperitoneal gelegene Drüse besitzt enge topographische Beziehungen zu Duodenum, den Gallenwegen, der Milz und zu den Oberbauchgefäßen. Gefäßvarianten besonders der arteriellen Durchblutung von Leber und Querkolon sind bei Pankreasresektionen zu bedenken und zu berücksichtigen. Hauptfunktion des exokrinen Pankreas besteht in der Sekretion von bikarbonathaltiger Flüssigkeit und von Verdauungsenzymen. Man unterscheidet zwischen der digestiven und der interdigestiven (postprandialen) Sekretionsphase des Pankreas. Beide Phasen werden mit verschiedenen Motilitätsaktivitäten des oberen Magen-Darm-Traktes und des Gallenwegssystems während der kephalen, gastrischen und intestinalen Verdauungsphase koordiniert.
    12/2010: pages 803-861;
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    ABSTRACT: Patients at nutritional risk reveal an increased morbidity. Fast-track (FT) programs in colonic surgery have shown reduced complications and hospital stay. We aimed to assess the effect of FT programs on patients at nutritional risk. In a randomized trial (NCT00556790), we compared complications after open colonic surgery with either a FT program or standard care (SC). A subgroup analysis was performed in 67 patients for whom a prospective nutritional risk score (NRS) was available. The SC and FT groups did not differ regarding patient characteristics or prevalence of NRS ≥ 3 (SC 8/31, FT 7/36, p = 0.569). Patients with SC had more complications (14/31 vs. 8/36, p = 0.044) and a longer hospital stay (9 vs. 5 days, p < 0.0001). No major complication occurred in patients with an NRS <3. Patients at nutritional risk had a high complication rate regardless of SC or FT (6/8 and 5/7, respectively, p = 1.000). Median hospital stay was shorter in FT (7 (range 5-30) days) versus SC patients (14.5 (range 8-30) days, p = 0.164). Patients with a NRS ≥ 3 have an increased postoperative morbidity even within a FT program. They should be identified by nutritional screening and might benefit from nutritional supplements.
    Digestive surgery 11/2010; 27(5):436-9. · 1.37 Impact Factor
  • P A Clavien, M Weber, A Nocito
    British Journal of Surgery 02/2010; 97(2):296-297. · 4.84 Impact Factor
  • P A Clavien, R Graf
    British Journal of Surgery 09/2009; 96(9):965-6. · 4.84 Impact Factor
  • Journal de Chirurgie 10/2008; 145(5):499. · 0.50 Impact Factor
  • RöFo - Fortschritte auf dem Gebiet der R 01/2008; 180. · 1.96 Impact Factor

Publication Stats

6k Citations
783.76 Total Impact Points

Institutions

  • 2000–2014
    • University of Zurich
      • • Center for Microscopy and Image Analysis - ZMB
      • • Klinik für Viszeral- und Transplantationschirurgie
      Zürich, Zurich, Switzerland
    • University of Groningen
      • Department of Surgery
      Groningen, Province of Groningen, Netherlands
  • 2010
    • University Hospital of Lausanne
      • Service de chirurgie viscérale
      Lausanne, VD, Switzerland
  • 1995–2001
    • Duke University Medical Center
      • • Department of Surgery
      • • Department of Medicine
      Durham, NC, United States
  • 1990–1996
    • University of Toronto
      • Department of Surgery
      Toronto, Ontario, Canada
  • 1991–1993
    • Samuel Lunenfeld Research Institute
      Toronto, Ontario, Canada
    • Mount Sinai Hospital, Toronto
      • Department of Surgery
      Toronto, Ontario, Canada
  • 1988–1992
    • University of Geneva
      • Department of Surgery
      Genève, GE, Switzerland