Management of perioperative iron deficiency anemia as part of patient blood management in France: A budget impact model-based analysis based on real world data.

OBJECTIVES: Patient Blood Management (PBM) is defined as a patient-centered, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood, while promoting patient safety and empowerment. As a corollary, it also reduces the utilization of allogeneic blood components. However, demonstrating cost-effectiveness depends on the health insurance system considered. This analysis aims to estimate the one-year budget impact of PBM in four elective surgical areas, from French National Health Insurance and hospital perspectives. METHODS: A budget impact model was developed to estimate the difference in the cost of care between scenarios with and without PBM. The impact of hematopoiesis optimization (first pillar of PBM) was studied throughout the management of preoperative anemia and iron deficiency in four types of surgeries: orthopedic, cardiac & cardiovascular, vascular & thoracic, and urologic & visceral surgery. Estimation of model's parameters was based on data collected in 10 French hospitals, literature, and on data from the French national medico-administrative database. RESULTS: A total of 980,125 patients were modeled for all four therapeutic areas. Results shows that implementation of a PBM program could generate annual savings up to €1079 M from the French National Health Insurance perspective (€1018 M from the hospital perspective), and the sparing of 181,451 red blood cells units per year. The deterministic sensitivity analysis showed that PBM generates savings for both perspectives in most parameters tested. CONCLUSION: Implementing PBM programs could result in important savings for the health care system in France.

Predictors for Survival in an International Cohort of Patients Undergoing Distal Pancreatectomy for Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Surgical factors, including resection of Gerota's fascia, R0-resection, and lymph node yield, may be associated with survival after distal pancreatectomy (DP) for pancreatic ductal adenocarcinoma (PDAC), but evidence from large multicenter studies is lacking. This study aimed to identify predictors for overall survival after DP for PDAC, especially those related to surgical technique. PATIENTS AND METHODS: Data from an international retrospective cohort including patients from 11 European countries and the USA who underwent DP for PDAC (2007-2015) were analyzed. Cox proportional hazard analyses were performed and included Gerota's fascia resection, R0 resection, lymph node ratio, extended resection, and a minimally invasive approach. RESULTS: Overall, 1200 patients from 34 centers with median follow-up of 15 months [interquartile range (IQR) 5-31 months] and median survival period of 30 months [95% confidence interval (CI), 27-33 months] were included. Gerota's fascia resection [hazard ratio (HR) 0.74; p = 0.019], R0 resection (HR 0.70; p = 0.006), and decreased lymph node ratio (HR 0.28; p < 0.001) were associated with improved overall survival, whereas extended resection (HR 1.75; p < 0.001) was associated with worse overall survival. A minimally invasive approach did not improve survival as compared with an open approach (HR 1.14; p = 0.350). Adjuvant chemotherapy (HR 0.67; p = 0.003) was also associated with improved overall survival. CONCLUSIONS: This international cohort identified Gerota's fascia resection, R0 resection, and decreased lymph node ratio as factors associated with improved overall survival during DP for PDAC. Surgeons should strive for R0 resection and adequate lymphadenectomy and could also consider Gerota's fascia resection in their routine surgical approach.

Laparoscopic versus open resection of intrahepatic cholangiocarcinoma: nationwide analysis.

BACKGROUND: The relevance of laparoscopic resection of intrahepatic cholangiocarcinoma (ICC) remains debated. The aim of this study was to compare laparoscopic (LLR) and open (OLR) liver resection for ICC, with specific focus on textbook outcome and lymph node dissection (LND). METHODS: Patients undergoing LLR or OLR for ICC were included from two French, nationwide hepatopancreatobiliary surveys undertaken between 2000 and 2017. Patients with negative margins, and without transfusion, severe complications, prolonged hospital stay, readmission or death were considered to have a textbook outcome. Patients who achieved both a textbook outcome and LND were deemed to have an adjusted textbook outcome. OLR and LLR were compared after propensity score matching. RESULTS: In total, 548 patients with ICC (127 LLR, 421 OLR) were included. Textbook-outcome and LND completion rates were 22.1 and 48.2 per cent respectively. LLR was independently associated with a decreased rate of LND (odds ratio 0.37, 95 per cent c.i. 0.20 to 0.69). After matching, 109 patients remained in each group. LLR was associated with a decreased rate of transfusion (7.3 versus 21.1 per cent; P = 0.001) and shorter hospital stay (median 7 versus 14 days; P = 0.001), but lower rate of LND (33.9 versus 73.4 per cent; P = 0.001). Patients who underwent LLR had lower rate of adjusted TO completion than patients who had OLR (6.5 versus 17.4 per cent; P = 0.012). CONCLUSION: The laparoscopic approach did not substantially improve quality of care of patients with resectable ICC.

Impact of cirrhosis in patients undergoing laparoscopic liver resection in a nationwide multicentre survey.

BACKGROUND: The aim was to analyse the impact of cirrhosis on short-term outcomes after laparoscopic liver resection (LLR) in a multicentre national cohort study. METHODS: This retrospective study included all patients undergoing LLR in 27 centres between 2000 and 2017. Cirrhosis was defined as F4 fibrosis on pathological examination. Short-term outcomes of patients with and without liver cirrhosis were compared after propensity score matching by centre volume, demographic and tumour characteristics, and extent of resection. RESULTS: Among 3150 patients included, LLR was performed in 774 patients with (24·6 per cent) and 2376 (75·4 per cent) without cirrhosis. Severe complication and mortality rates in patients with cirrhosis were 10·6 and 2·6 per cent respectively. Posthepatectomy liver failure (PHLF) developed in 3·6 per cent of patients with cirrhosis and was the major cause of death (11 of 20 patients). After matching, patients with cirrhosis tended to have higher rates of severe complications (odds ratio (OR) 1·74, 95 per cent c.i. 0·92 to 3·41; P = 0·096) and PHLF (OR 7·13, 0·91 to 323·10; P = 0·068) than those without cirrhosis. They also had a higher risk of death (OR 5·13, 1·08 to 48·61; P = 0·039). Rates of cardiorespiratory complications (P = 0·338), bile leakage (P = 0·286) and reoperation (P = 0·352) were similar in the two groups. Patients with cirrhosis had a longer hospital stay than those without (11 versus 8 days; P = 0·018). Centre expertise was an independent protective factor against PHLF in patients with cirrhosis (OR 0·33, 0·14 to 0·76; P = 0·010). CONCLUSION: Underlying cirrhosis remains an independent risk factor for impaired outcomes in patients undergoing LLR, even in expert centres.

ANTECEDENTES: El objetivo de este estudio fue analizar el impacto de la cirrosis en los resultados a corto plazo después de la resección hepática laparoscópica (laparoscopic liver resection, LLR) en un estudio de cohortes multicéntrico nacional. MÉTODOS: Este estudio retrospectivo incluyó todos los pacientes sometidos a LLR en 27 centros entre 2000 y 2017. La cirrosis se definió como fibrosis F4 en el examen histopatológico. Los resultados a corto plazo de los pacientes con hígado cirrótico (cirrhotic liver CL) (pacientes CL) y los pacientes con hígado no cirrótico (non-cirrhotic liver, NCL) (pacientes NCL) se compararon después de realizar un emparejamiento por puntaje de propension del volumen del centro, las características demográficas y del tumor, y la extensión de la resección. RESULTADOS: Del total de 3.150 pacientes incluidos, se realizó LLR en 774 (24,6%) pacientes CL y en 2.376 (75,4%) pacientes NCL. Las tasas de complicaciones graves y mortalidad en el grupo de pacientes CL fueron del 10,6% y 2,6%, respectivamente. La insuficiencia hepática posterior a la hepatectomía (post-hepatectomy liver failure, PHLF) fue la principal causa de mortalidad (55% de los casos) y se produjo en el 3,6% de los casos en pacientes CL. Después del emparejamiento, los pacientes CL tendieron a tener tasas más altas de complicaciones graves (razón de oportunidades, odds ratio, OR 1,74; i.c. del 95% 0,92-0,41; P = 0,096) y de PHLF (OR 7,13; i.c. del 95% 0,91-323,10; P = 0,068) en comparación con los pacientes NCL. Los pacientes CL estuvieron expuestos a un mayor riesgo de mortalidad (OR 5,13; i.c. del 95% 1,08-48,6; P = 0,039) en comparación con los pacientes NCL. Los pacientes CL presentaron tasas similares de complicaciones cardiorrespiratorias graves (P = 0,338), de fuga biliar (P = 0,286) y de reintervenciones (P = 0,352) que los pacientes NCL. Los pacientes CL tuvieron una estancia hospitalaria más larga (11 versus 8 días; P = 0,018) que los pacientes NCL. La experiencia del centro fue un factor protector independiente de PHLF (OR 0,33; i.c. del 95% 0,14-0,76; P = 0,010) pacientes CL. CONCLUSIÓN: La presencia de cirrosis subyacente sigue siendo un factor de riesgo independiente de peores resultados en pacientes sometidos a resección hepática laparoscópica, incluso en centros con experiencia.

Composition conserving defects and their influence on the electronic properties of thermoelectric TiNiSn.

Formation of composition conserving defects is an inherent feature that appears in compounds for thermoelectric applications during the processes of their fabrication. Different types of such defects including exchange antisite defects, Schottky defects, and triple-, quatro- and penta-defects in TiNiSn are considered. Density functional theory calculations of the energy of formation of these defects are carried out. It is demonstrated that their formation may lead to a significant decrease of the band gap (Eg), simultaneously causing a transformation to p-type or semi-metal conductivity in this material. The role of nanopores is discussed. It is shown that preparing nanoporous compounds may be an efficient way to create p-type TiNiSn, simultaneously decreasing the thermal conductivity and improving its thermoelectric parameters.

Multicentre propensity score-matched study of laparoscopic versus open repeat liver resection for colorectal liver metastases.

BACKGROUND: Repeat liver resection is often the best treatment option for patients with recurrent colorectal liver metastases (CRLM). Repeat resections can be complex, however, owing to adhesions and altered liver anatomy. It remains uncertain whether the advantages of a laparoscopic approach are upheld in this setting. The aim of this retrospective, propensity score-matched study was to compare the short-term outcome of laparoscopic (LRLR) and open (ORLR) repeat liver resection. METHODS: A multicentre retrospective propensity score-matched study was performed including all patients who underwent LRLRs and ORLRs for CRLM performed in nine high-volume centres from seven European countries between 2000 and 2016. Patients were matched based on propensity scores in a 1 : 1 ratio. Propensity scores were calculated based on 12 preoperative variables, including the approach to, and extent of, the previous liver resection. Operative outcomes were compared using paired tests. RESULTS: Overall, 425 repeat liver resections were included. Of 271 LRLRs, 105 were matched with an ORLR. Baseline characteristics were comparable after matching. LRLR was associated with a shorter duration of operation (median 200 (i.q.r. 123-273) versus 256 (199-320) min; P < 0·001), less intraoperative blood loss (200 (50-450) versus 300 (100-600) ml; P = 0·077) and a shorter postoperative hospital stay (5 (3-8) versus 6 (5-8) days; P = 0·028). Postoperative morbidity and mortality rates were similar after LRLR and ORLR. CONCLUSION: LRLR for CRLM is feasible in selected patients and may offer advantages over an open approach.

The effect of metabolic syndrome on postoperative outcomes following laparoscopic colectomy.

BACKGROUND: Among the criteria used to diagnose metabolic syndrome (MS), obesity and diabetes mellitus (DM) are associated with poor postoperative outcomes following colectomy. MS is also associated with colorectal cancer (CRC) and diverticulosis, both of which may be treated with colectomy. However, the effect of MS on postoperative outcomes following laparoscopic colectomy has yet to be clarified. METHODS: In an academic tertiary hospital, data from all consecutive patients undergoing laparoscopic colectomy from 2005 to 2014 were prospectively recorded and analysed. Patients presenting with MS [defined by the presence of three or more of the following criteria: elevated blood pressure, body mass index > 28 kg/m2, dyslipidemia (decreased serum HDL cholesterol, increased serum triglycerides) and increased fasting glucose/DM] were compared with patients without MS regarding peri-operative outcome [mainly anastomotic leaks, severe postoperative complications (Clavien-Dindo III and IV)] and mortality. RESULTS: Overall, 1236 patients were included: 508 (41.1%) right colectomies and 728 (58.9%) left colectomies. Seven hundred seventy-two (62.4%) of these procedures were performed for CRC. MS was diagnosed in 85 (6.9%) patients, who were significantly older than the others (70 vs. 64.2 years, p < 0.001), and presented with more cardiac comorbidities (p < 0.001). MS was associated with increased blood loss (122.5 vs. 79.9 mL p = 0.001) and blood transfusion requirement (5.9 vs. 1.7%, p = 0.021). The anastomotic leak rate was 6.6% (with 2.2% of anastomotic leaks requiring surgical treatment), and the overall reoperation rate was 6.9%. The incidence of severe postoperative complications was 11.5%, and the overall mortality rate 0.6%. No differences were found between the groups in overall postoperative morbidity and mortality. Median length of stay was similar in both groups (7 days). CONCLUSIONS: MS does not jeopardize postoperative outcomes following laparoscopic colectomy.

Preoperative imaging and prediction of oesophageal conduit necrosis after oesophagectomy for cancer.

BACKGROUND: Oesophageal conduit necrosis following oesophagectomy is a rare but life-threatening complication. The present study aimed to assess the impact of coeliac axis stenosis on outcomes after oesophagectomy for cancer. METHODS: The study included consecutive patients who had an Ivor Lewis procedure with curative intent for middle- and lower-third oesophageal cancer at two tertiary referral centres. All patients underwent preoperative multidetector CT with arterial phase to detect coeliac axis stenosis. The coeliac artery was classified as normal, with extrinsic stenosis due to a median arcuate ligament or with intrinsic stenosis caused by atherosclerosis. RESULTS: Some 481 patients underwent an Ivor Lewis procedure. Of these, ten (2·1 per cent) developed oesophageal conduit necrosis after surgery. Coeliac artery evaluation revealed a completely normal artery in 431 patients (91·5 per cent) in the group without conduit necrosis and in one (10 per cent) with necrosis (P < 0·001). Extrinsic stenosis of the coeliac artery due to a median arcuate ligament was found in two patients (0·4 per cent) without conduit necrosis and five (50 per cent) with necrosis (P < 0·001). Intrinsic stenosis of the coeliac artery was found in 11 (2·3 per cent) and eight (80 per cent) patients respectively (P < 0·001). Eight patients without (1·7 per cent) and five (50 per cent) with conduit necrosis had a single and thin left gastric artery (P < 0·001). CONCLUSION: This study suggests that oesophageal conduit necrosis after oesophagectomy for cancer may be due to pre-existing coeliac axis stenosis.

Multicentre study of the impact of morbidity on long-term survival following hepatectomy for intrahepatic cholangiocarcinoma.

BACKGROUND: The impact of morbidity on long-term outcomes following liver resection for intrahepatic cholangiocarcinoma is currently unclear. METHODS: This was a retrospective analysis of all consecutive patients who underwent liver resection for intrahepatic cholangiocarcinoma with curative intent in 24 university hospitals between 1989 and 2009. Severe morbidity was defined as any complication of Dindo-Clavien grade III or IV. Patients with severe morbidity were compared with those without in terms of demographics, pathology, management, morbidity, overall survival, disease-free survival and time to recurrence. Independent predictors of severe morbidity were identified by multivariable analysis. RESULTS: A total of 522 patients were enrolled. Severe morbidity occurred in 113 patients (21·6 per cent) and was an independent predictor of overall survival (hazard ratio 1·64, 95 per cent c.i. 1·21 to 2·23), as were age at resection, multifocal disease, positive lymph node status and R0 resection margin. Severe morbidity did not emerge as an independent predictor of disease-free survival. Independent predictors of time to recurrence included severe morbidity, tumour size, multifocal disease, vascular invasion and R0 resection margin. Major hepatectomy and intraoperative transfusion were independent predictors of severe morbidity. CONCLUSION: Severe morbidity adversely affects overall survival following liver resection for intrahepatic cholangiocarcinoma.

Combined electronic and thermodynamic approaches for enhancing the thermoelectric properties of Ti-doped PbTe.

Lead telluride based compounds are of great interest due to their enhanced thermoelectric transport properties. Nevertheless, the donor type impurities in this class of materials are currently mainly limited and alternative types of donor impurities are still required for optimizing the thermoelectric performance. In the current research titanium as a donor impurity in PbTe is examined. Although titanium is known to form resonant levels above the conduction band in PbTe, it does not enhance the thermo-power beyond the classical predictions. Recent experiments showed that alloying with a small amount of Ti (∼0.1 at%) gives a significant increase in the figure of merit. In the current research ab initio calculations were applied in order to correlate the reported experimental results with a thermoelectric optimization model. It was found that a Ti concentration of ∼1.4 at% in the Pb sublattice is expected to maximize the thermoelectric power factor. Using a statistical thermodynamic approach and in agreement with the previously reported appearance of a secondary intermetallic phase, the actual Ti solubility limit in PbTe is found to be ∼0.3 at%. Based on the proposed model, the mechanism for the formation of the previously observed secondary phase is attributed to phase separation reactions, characterized by a positive enthalpy of formation in the system. With extrapolation of the obtained ab initio results, it is demonstrated that lower Ti-doping concentrations than previously experimentally reported ones are expected to provide power factor values close to the maximal one, making doping with Ti a promising opportunity for the generation of highly efficient n-type PbTe-based thermoelectric materials.

Accuracy of staging laparoscopy in detecting peritoneal dissemination in patients with gastroesophageal adenocarcinoma.

Despite staging laparoscopy (SL) with peritoneal lavage is recommended in US Guidelines in patients with potentially resectable gastroesophageal adenocarcinoma, this procedure is not systematically proposed in French Guidelines. Therefore, we decided to analyze the results of systematic SL in patients considered for preoperative chemotherapy. From 2005 to 2011, 116 consecutive patients with distal esophagus, esogastric junction, and gastric adenocarcinoma ≥T3 or N+ without detectable metastatic dissemination by computed tomography (CT) scan imaging underwent SL before neoadjuvant chemotherapy. Positive and negative SLs were compared according to tumor characteristics. SL was positive in 15 cases (12.9%) including 14 with peritoneal seeding (localized in five, diffuse in nine). SL was positive in 7 (24.1%) of 29 patients with poorly differentiated tumor, in 9 (32.1%) of 28 patients with signet ring cells, in 7 (50%) of 14 patients with gastric linitis tumor, and in 15 (16.3%) of 92 patients with T3 or T4 tumor. All the lesions of distal esophagus extending to the cardia had a negative SL. Among the 14 patients with peritoneal carcinomatosis at SL, nine (65%) had signs of peritoneal seeding on initial CT scan. One (0.8%) patient had a small bowel perforation closed laparoscopically. If systematic SL before preoperative chemotherapy does not seem justified because of its low accuracy, it should be performed in patients with poorly differentiated tumor, signet ring cell, and gastric linitis plastica components on biopsy and when CT scan is suggestive of T4 tumor, ascites, or peritoneal nodule.

Risk factors for complications after laparoscopic major hepatectomy.

BACKGROUND: Although laparoscopic major hepatectomy (MH) is becoming increasingly common in several specialized centres, data regarding outcomes are limited. The aim of this study was to identify the risk factors for postoperative complications of purely laparoscopic MH at a single centre. METHODS: All patients who underwent purely laparoscopic MH between January 1998 and March 2014 at the authors' institution were enrolled. Demographic, clinicopathological and perioperative factors were collected prospectively, and data were analysed retrospectively. The dependent variables studied were the occurrence of overall and major complications (Dindo-Clavien grade III or above). RESULTS: A total of 183 patients were enrolled. The types of MH included left-sided hepatectomy in 40 patients (21·9 per cent), right-sided hepatectomy in 135 (73·8 per cent) and central hepatectomy in eight (4·4 per cent). Median duration of surgery was 255 (range 100-540) min, and median blood loss was 280 (10-4500) ml. Complications occurred in 100 patients (54·6 per cent), and the 90-day all-cause mortality rate was 2·7 per cent. Liver-specific and general complications occurred in 62 (33·9 per cent) and 38 (20·8 per cent) patients respectively. Multivariable analysis identified one independent risk factor for global postoperative complications: intraoperative simultaneous radiofrequency ablation (RFA) (odds ratio (OR) 6·93, 95 per cent c.i. 1·49 to 32·14; P = 0·013). There were two independent risk factors for major complications: intraoperative blood transfusion (OR 2·50, 1·01 to 6·23; P = 0·049) and bilobar resection (OR 2·47, 1·00 to 6·06; P = 0·049). CONCLUSION: Purely laparoscopic MH is feasible and safe. Simultaneous RFA and bilobar resection should probably be avoided.

Learning curve for laparoscopic major hepatectomy.

BACKGROUND: Laparoscopic major hepatectomy (LMH) is evolving as an important surgical approach in hepatopancreatobiliary surgery. The present study aimed to evaluate the learning curve for LMH at a single centre. METHODS: Data for all patients undergoing LMH between January 1998 and September 2013 were recorded in a prospective database and analysed. The learning curve for operating time (OT) was evaluated using the cumulative sum (CUSUM) method. RESULTS: Of 173 patients undergoing major hepatectomy, left hepatectomy was performed in 28 (16·2 per cent), left trisectionectomy in nine (5·2 per cent), right hepatectomy in 115 (66·5 per cent), right trisectionectomy in 13 (7·5 per cent) and central hepatectomy in eight (4·6 per cent). Median duration of surgery was 270 (range 100-540) min and median blood loss was 300 (10-4500) ml. There were 20 conversions to an open procedure (11·6 per cent). Vascular clamping was independently associated with conversion on multivariable analysis (hazard ratio 5·95, 95 per cent c.i. 1·24 to 28·56; P = 0·026). The CUSUMOT learning curve was modelled as a parabola (CUSUMOT = 0·2149 × patient number(2) - 30·586 × patient number - 1118·3; R(2) = 0·7356). The learning curve comprised three phases: phase 1 (45 initial patients), phase 2 (30 intermediate patients) and phase 3 (the subsequent 98 patients). Although right hepatectomy was most common in phase 1, a significant decrease was observed from phase 1 to 3 (P = 0·007) in favour of more complex procedures. CONCLUSION: The learning curve for LMH consisted of three characteristic phases identified by CUSUM analysis. The data suggest that the learning phase of LMH included 45 to 75 patients.

Laparoscopic two-stage hepatectomy for bilobar colorectal liver metastases.

BACKGROUND: Despite the gradual diffusion of laparoscopic liver resection, the feasibility and results of laparoscopic two-stage hepatectomy (TSH) for bilobar colorectal liver metastases (CRLM) have not been described frequently. This study aimed to evaluate the feasibility, safety and oncological outcomes of laparoscopic TSH for bilobar CRLM. METHODS: All patients eligible for laparoscopic TSH among those treated for bilobar CRLM from 2000 to 2013 were included. Demographics, tumour characteristics, surgical procedures, and short- and long-term outcomes were analysed. RESULTS: Laparoscopic TSH was planned in 34 patients with bilobar CRLM, representing 17·2 per cent of all 198 patients treated for bilobar CRLM. Thirty patients received preoperative chemotherapy, and 20 had portal vein occlusion to increase the volume of the remnant liver. Laparoscopic resection of the primary colorectal tumour was integrated within the first-stage hepatectomy in 11 patients. After a median interval of 3·1 months, 26 patients subsequently had a successful laparoscopic second-stage hepatectomy, including 18 laparoscopic right or extended right hepatectomies. The mortality rate for both stages was 3 per cent (1 of 34), and the overall morbidity rate for the first and second stages was 50 per cent (17 of 34) and 54 per cent (14 of 26) respectively. Mean length of hospital stay was 6·1 and 9·0 days respectively. With a median follow-up of 37·8 (range 6-129) months, 3- and 5-year overall survival rates in patients who completed TSH were 78 and 41 per cent respectively. The 3- and 5-year disease-free survival rates were 26 and 13 per cent respectively. CONCLUSION: Laparoscopic TSH for bilobar CRLM is safe and does not jeopardize long-term outcomes in selected patients.

Risk factors and consequences of conversion in laparoscopic major liver resection.

BACKGROUND: Although recent reports have suggested potential benefits of the laparoscopic approach in patients requiring major hepatectomy, it remains unclear whether conversion to open surgery could offset these advantages. This study aimed to determine the risk factors for and postoperative consequences of conversion in patients undergoing laparoscopic major hepatectomy (LMH). METHODS: Data for all patients undergoing LMH between 2000 and 2013 at two tertiary referral centres were reviewed retrospectively. Risk factors for conversion were determined using multivariable analysis. After propensity score matching, the outcomes of patients who underwent conversion were compared with those of matched patients undergoing laparoscopic hepatectomy who did not have conversion, operated on at the same centres, and also with matched patients operated on at another tertiary centre during the same period by an open laparotomy approach. RESULTS: Conversion was needed in 30 (13·5 per cent) of the 223 patients undergoing LMH. The most frequent reasons for conversion were bleeding and failure to progress, in 14 (47 per cent) and nine (30 per cent) patients respectively. On multivariable analysis, risk factors for conversion were patient age above 75 years (hazard ratio (HR) 7·72, 95 per cent c.i. 1·67 to 35·70; P = 0·009), diabetes (HR 4·51, 1·16 to 17·57; P = 0·030), body mass index (BMI) above 28 kg/m(2) (HR 6·41, 1·56 to 26·37; P = 0·010), tumour diameter greater than 10 cm (HR 8·91, 1·57 to 50·79; P = 0·014) and biliary reconstruction (HR 13·99, 1·82 to 238·13; P = 0·048). After propensity score matching, the complication rate in patients who had conversion was higher than in patients who did not (75 versus 47·3 per cent respectively; P = 0·038), but was not significantly different from the rate in patients treated by planned laparotomy (79 versus 67·9 per cent respectively; P = 0·438). CONCLUSION: Conversion during LMH should be anticipated in patients with raised BMI, large lesions and biliary reconstruction. Conversion does not lead to increased morbidity compared with planned laparotomy.

Long-term survival after pancreatic resection for renal cell carcinoma metastasis.

BACKGROUND: Surgical resection of pancreatic metastasis (PM) is the only reported curative treatment for renal cell carcinoma. However, there is currently little information regarding very long-term survival. The primary objective of this study was to determine the 10-year survival of this condition using the largest surgical series reported to date. METHODS: Between May 1987 and June 2003, we conducted a retrospective study of 62 patients surgically treated for PM from renal cell carcinoma at 12 Franco-Belgian surgical centers. Follow-up ended on May 31, 2012. RESULTS: There were 27 male (44 %) and 35 female (56 %) patients with a median age of 54 years [31-75]. Mean disease-free interval from resection of primary tumor to reoperation for pancreatic recurrence was 9.8 years (median 10 years [0-25]). During a median follow-up of 91 months [12-250], 37 recurrences (60 %) were observed. After surgical resection of repeated recurrences, overall median survival time was 52.6 months versus 11.2 months after nonoperative management (p = 0.019). Cumulative 3-, 5-, and 10-year overall survival (OS) rates were 72, 63, and 32 %, respectively. The corresponding disease-free survival rates were 54, 35, and 27 %, respectively. Lymph node involvement and existence of extrapancreatic metastases before PM were associated with poor overall survival. CONCLUSIONS: Aggressive surgical management of single or multiple PM, even in cases of extrapancreatic disease, should be considered in selected patients to allow a chance of long-term survival.

Intracystic concentrations of tumour markers for the diagnosis of cystic liver lesions.

BACKGROUND: Imaging occasionally fails to differentiate hepatic simple cysts from malignant or premalignant mucinous cystic lesions such as biliary cystadenomas. Hepatic simple cysts can be treated conservatively, whereas malignant or premalignant cysts require complete resection. This study assessed the ability of intracystic tumour marker concentrations to differentiate these disease entities. METHODS: Intracystic fluid was sampled in patients undergoing partial or complete resection of a cystic lesion of the liver. The indication for surgery in hepatic simple cysts was symptoms or suspicion of a biliary cystadenoma. Intracystic concentrations of carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9 and tumour-associated glycoprotein (TAG) 72 were measured to assess the diagnostic accuracy of these tumour markers. Cut-off values were defined by receiver operating characteristic (ROC) curves. RESULTS: The study population comprised 118 patients (94 women) with a median age of 59 years. There were 75 patients with hepatic simple cysts, 27 with mucinous cysts (19 biliary cystadenomas, 4 biliary cystadenocarcinomas, 4 intraductal papillary mucinous neoplasms of the bile duct) and 16 with miscellaneous cysts. Unlike CEA and CA19-9, a TAG-72 concentration of more than 25 units/ml differentiated hepatic simple cysts from mucinous cysts with a sensitivity and a specificity of 0·79 and 0·97 respectively. The area under the ROC curve was 0·98 for mucinous versus hepatic simple cysts. CONCLUSION: The concentration of TAG-72 in cyst fluid accurately identified hepatic cysts that required complete resection.

Influence of bile duct obstruction on the results of Frey's procedure for chronic pancreatitis.

OBJECTIVES: To evaluate the influence of a biliary obstruction (BO) requiring biliary bypass on both short and long-term outcomes of patients undergoing Frey's procedure for chronic pancreatitis (CP). METHODS: From 1999 to 2010, 33 consecutive patients underwent Frey's procedure for CP in two centers. Seventeen (54%) patients underwent biliary bypass to treat an associated BO. Characteristics and outcomes of these patients were compared to those of 16 others without BO. RESULTS: Patients with BO had more severe disease including lower BMI and larger pancreatic head (4 cm vs. 6 cm, p = 0.021). The operative mortality was nil. Patients with BO experienced more overall postoperative complications (71% vs. 31%, p = 0.024) but similar major complication rates (18% vs. 6%, p = 0.316) compared to those without BO. After a median follow-up of 51 (1-96) months, 91% of the patients experienced either partial or complete relief of their symptoms and 36% exhibited deterioration of their endocrine function. Multivariate analysis revealed preoperative BO to be associated with long-term impairment of endocrine function (OR: 43.249; 95% CI 2.221-84.277; p = 0.013). CONCLUSION: In patients undergoing Frey's procedure for CP, associated BO can be safely managed using biliary bypass. However, the severity of CP in these patients is responsible for a higher risk of long-term endocrine insufficiency.

An ab initio study of the thermoelectric enhancement potential in nano-grained TiNiSn.

Novel approaches for the development of highly efficient thermoelectric materials capable of a direct conversion of heat into electricity, are being constantly investigated. TiNiSn based half-Heusler alloys exhibit a high thermoelectric potential for practical, renewable power generation applications. The main challenge of further enhancement of the thermoelectric efficiency of these alloys lies in the reduction of the associated high lattice thermal conductivity values without adversely affecting the electronic transport properties. The current manuscript theoretically investigates two possible routes for overcoming this limitation in TiNiSn alloys. On the one hand, the influence of nano-grained structure of TiNiSn on the electronic structure of the material is theoretically demonstrated. On the other hand, the potential for thermal conductivity reduction upon increasing the Ni fraction in the intermetallic TiNiSn compound via the formation of metallic TiNi2Sn nanoparticles is also shown. Using the applied approach, a useful route for optimizing both the electronic and thermal properties of half-Heusler TiNiSn, for practical thermoelectric applications, is demonstrated.