The single surgeon learning curve of laparoscopic liver resection : a continuous evolving process through stepwise difficulties

The aim of the study was to evaluate the single-surgeon learning curve (SSLC) in laparoscopic liver surgery over an 11-year period with risk-adjusted (RA) cumulative sum control chart analysis.Laparoscopic liver resection (LLR) is a challenging and highly demanding procedure. No specific data are available for defining the feasibility and reproducibility of the SSLC regarding a consistent and consecutive caseload volume over a specified time period.A total of 319 LLR performed by a single surgeon between June 2003 and May 2014 were retrospectively analyzed. A difficulty scale (DS) ranging from 1 to 10 was created to rate the technical difficulty of each LLR. The risk-adjusted cumulative sum control chart (RA-CUSUM) analysis evaluated conversion rate (CR), operative time (OT) and blood loss (BL). Perioperative morbidity and mortality were also analyzed.The RA-CUSUM analysis of the DS identified 3 different periods: P1 (n = 91 cases), with a mean DS of 3.8; P2 (cases 92-159), with a mean DS of 5.3; and P3 (cases 160-319), with a mean DS of 4.7. P2 presented the highest conversion and morbidity rates with a longer OT, whereas P3 showed the best results (P<0.001). Fifty cases were needed to achieve a significant decrease in BL. The overall morbidity rate was 13.8%; no perioperative mortality was observed.According to our analysis, at least 160 cases (P3) are needed to complete the SSLC performing safely different types of LLR. A minimum of 50 cases can provide a significant decrease in BL. Based on these findings, a longer learning curve should be anticipated to broaden the indications for LLR

Hematology, Biochemistry and Serum Protein Analyses of Antarctic and non-Antarctic Skuas

Determination of hematological and biochemical parameters provides important data to assess the physiological condition in wild birds. Therefore, to carry out ecophysiology or conservation studies it is essential to establish baseline physiological parameters and how these change with age and life history events. Hematological (hematocrit, hemoglobin and erythrocyte sedimentation) and biochemical (glucose, total lipids and proteins, aspartate and alanine aminotransferase activities and electrolyte concentration) reference values were determined in two Antarctic migratory bird species, the Brown Skua (Stercorarius antarcticus) and South Polar Skua (S. maccormicki), from South Shetland Island during breeding season. Also, hematological data (hematocrit) were determined for non-Antarctic skuas, with Chilean (S. chilensis) and Falkland (S. antarcticus antarcticus) skuas sampled in the Beagle Channel islands (Tierra del Fuego Province) and Viana Island (Chubut Province), Argentina, respectively. Differences between adult Antarctic skua species were observed in hemoglobin, erythrocyte sedimentation, total lipids and aspartate aminotransferase activity. In addition, age-related differences in Antarctic skuas in hematocrit, hemoglobin, glucose and total protein values were observed. Serum reference protein fractions (Albumin, α1, α2, and globulins) were assessed by electrophoresis for Antarctic and non-Antarctic skuas. Similar protein patterns were observed between South Polar and Chilean skuas as well between Falkland Skua and Brown Skua. The differences between adult sympatric Antarctic skuas may be related to their nutritional status and species-specific migrations, feeding habits and the differential use of the breeding niches, while the age variation may be related to physiological development processes in chicks or to the energy expenditure in adults during breeding.Fil: Ibañez, Andres Esteban. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Najle, Roberto. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Larsen, Karen Elizabeth. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Montalti, Diego. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico Zoología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Conversione a OpenCL di un simulatore cardiaco parallelo

In questa tesi discuteremo come è possibile effettuare la traduzione di un software parallelo scritto in linguaggio CUDA ad uno in linguaggio OpenCL. Tratteremo le tecnologie utilizzate per lo sviluppo di un simulatore cardiaco parallelo e discuteremo in particolar modo come derivare da queste una versione che ne permetta l’esecuzione su schede video e processori arbitrari. Questa versione verrà messa poi a confronto con quelle già esistenti, per analizzarne prestazioni ed eventuali cambiamenti strutturali del codice. Quanto affermato sopra è stato possibile in gran parte grazie ad un wrapper chiamato SimpleCL pensato per rendere la programmazione OpenCL simile a quella in ambiente CUDA. OpenCL permette di operare con le unità di calcolo in maniera molto astratta, ricordando vagamente i concetti di astrazione di memoria e processori della controparte NVIDIA. Ragionevolmente SimpleCL fornisce solamente una interfaccia che ricorda chiamate CUDA, mantenendo il flusso sottostante fedele a quello che si aspetterebbe OpenCL

Outcomes of robotic vs laparoscopic hepatectomy : a systematic review and meta-analysis

AIM: To perform a systematic review and meta-analysis on robotic-assisted vs laparoscopic liver resections. METHODS: A systematic literature search was performed using PubMed, Scopus and the Cochrane Library Central. Participants of any age and sex, who underwent robotic or laparoscopic liver resection were considered following these criteria: (1) studies comparing robotic and laparoscopic liver resection; (2) studies reporting at least one perioperative outcome; and (3) if more than one study was reported by the same institute, only the most recent was included. The primary outcome measures were set for estimated blood loss, operative time, conversion rate, R1 resection rate, morbidity and mortality rates, hospital stay and major hepatectomy rates. RESULTS: A total of 7 articles, published between 2010 and 2014, fulfilled the selection criteria. The laparoscopic approach was associated with a significant reduction in blood loss and lower operative time (MD = 83.96, 95% CI: 10.51-157.41, P = 0.03; MD = 68.43, 95% CI: 39.22-97.65, P < 0.00001, respectively). No differences were found with respect to conversion rate, R1 resection rate, morbidity and hospital stay. CONCLUSION: Laparoscopic liver resection resulted in reduced blood loss and shorter surgical times compared to robotic liver resections. There was no difference in conversion rate, R1 resection rate, morbidity and length of postoperative stay

Hematology, Biochemistry and Serum Protein Analyses of Antarctic and non-Antarctic Skuas

Determination of hematological and biochemical parameters provides important data to assess the physiological condition in wild birds. Therefore, to carry out ecophysiology or conservation studies it is essential to establish baseline physiological parameters and how these change with age and life history events. Hematological (hematocrit, hemoglobin and erythrocyte sedimentation) and biochemical (glucose, total lipids and proteins, aspartate and alanine aminotransferase activities and electrolyte concentration) reference values were determined in two Antarctic migratory bird species, the Brown Skua (Stercorarius antarcticus) and South Polar Skua (S. maccormicki), from South Shetland Island during breeding season. Also, hematological data (hematocrit) were determined for non-Antarctic skuas, with Chilean (S. chilensis) and Falkland (S. antarcticus antarcticus) skuas sampled in the Beagle Channel islands (Tierra del Fuego Province) and Viana Island (Chubut Province), Argentina, respectively. Differences between adult Antarctic skua species were observed in hemoglobin, erythrocyte sedimentation, total lipids and aspartate aminotransferase activity. In addition, age-related differences in Antarctic skuas in hematocrit, hemoglobin, glucose and total protein values were observed. Serum reference protein fractions (Albumin, α1, α2, and globulins) were assessed by electrophoresis for Antarctic and non-Antarctic skuas. Similar protein patterns were observed between South Polar and Chilean skuas as well between Falkland Skua and Brown Skua. The differences between adult sympatric Antarctic skuas may be related to their nutritional status and species-specific migrations, feeding habits and the differential use of the breeding niches, while the age variation may be related to physiological development processes in chicks or to the energy expenditure in adults during breeding.Facultad de Ciencias Naturales y Muse

Post-operative morbidity following pancreatic duct occlusion without anastomosis after pancreaticoduodenectomy: a systematic review and meta-analysis

Background: Pancreatic duct occlusion (PDO) without anastomosis is a technique proposed to mitigate the clinical consequences of postoperative pancreatic fistulas (POPF) after pancreaticoduodenectomy. The aim of this study was to appraise the morbidity following PDO through a systematic review and meta-analysis. Methods: A systematic search of MEDLINE, Embase, and Web Of Science identified studies reporting outcomes of PDO following pancreaticoduodenectomy. Pooled prevalence rates of postoperative complications and mortality were computed using random-effect modeling. Meta-regression analyses were performed to examine the impact of moderators on the overall estimates. Results: Sixteen studies involving 1000 patients were included. Pooled postoperative mortality was 2.7%. A POPF was reported in 29.7% of the patients. Clinically relevant POPFs occurred in 13.5% of the patients, while intra-abdominal abscess and haemorrhages occurred in 6.7% and 5.5% of the patients, respectively. Re-operation was necessary in 7.6% of the patients. Postoperatively new onset diabetes occurred in 15.8% of patients, more frequently after the use of chemical substances for PDO (p = 0.003). Conclusions: PDO is associated with significant morbidity including new onset of post-operative diabetes. The risk of new onset post-operative diabetes is associated with the use of chemical substance for PDO. Further evidence is needed to evaluate the potential benefits of PDO in patients at high risk of POPF

Pure laparoscopic formal right hepatectomy versus anatomical posterosuperior segmental resections : a comparative study

Background: To analyze the differences in perioperative outcomes between laparoscopic formal right hepatectomies (RH) and laparoscopic anatomical posterosuperior (PS) resections, including segmentectomies in PS segment SVII and right posterior sectionectomies (segment VI and VII resection). Methods: A retrospective analysis of all patients undergoing laparoscopic formal RHs and anatomical PS resections, including segmentectomies in PS segment SVII and right posterior sectionectomies (segment VI and VII resection), between January 2010 and August 2017 was performed. The two groups were compared in terms of patients’ characteristics, intraoperative parameters, and short-term outcomes. Results: Sixty-eight patients were included of which 32 RHs and 36 anatomical PS resections. In the PS resection group, 18 had a segmentectomy of segment VII and 18 had a bisegmentectomy of both segments VI and VII. Patients’ preoperative data were comparable. The lesion size was higher in the RHs (P<0.001). A significant shorter operative time was found in the PS group: 280 [230–315] vs. 357 [300–463] min in the RH group (P<0.001). Blood loss was comparable: 520 [390–906] in the RHs vs. 560 [370–1,030] in the PS group (P=0.595). The overall morbidity rate was comparable being 25% in the RHs and 22.2% in the PS group (P=1.000). A longer length of stay (LOS) {7 [5–8] vs. 5 [4–7] days, P=0.012} and higher readmission rate (12.5% vs. 0%, P=0.044) was observed in the RHs compared to the PS cohort. Concerning surgical margins, the R0 rate was comparable in the two groups; 90.9% in the RHs vs. 95.2% in the PS group (P=1.000). Conclusions: When deemed feasible based on lesion position and size, the laparoscopic parenchyma-preserving approach using anatomical PS segmental resections is associated with shorter hospital stay and a lower readmission rate in respect to formal RH. Overall, short-term surgical parameters indicated that both procedures are safe and feasible in experienced hands, however both demand a great deal of technical expertise

Impact of remnant vital tissue after locoregional treatment and liver transplant in hepatocellular cancer patients. A multicentre cohort study

The role of pathological findings after locoregional treatments as predictors of hepatocellular cancer recurrence after liver transplantation has been poorly addressed. The aim of the study was to identify the role of remnant vital tissue (RVT) of the target lesion in predicting hepatocellular cancer recurrence. Two hundred and seventy-six patients firstly undergoing locoregional treatment and then transplanted between January 2010 and December 2015 in four European Transplant Centres (i.e. Rome Tor Vergata, Birmingham, Brussels and Ancona) were enrolled in the study to investigate the role of pathological response at upfront locoregional treatment. At multivariable Cox regression analysis, RVT ≥2 cm was a strong independent risk factor for post-LT recurrence (HR = 5.6; P < 0.0001). Five-year disease-free survival rates were 60.8%, 80.9% and 95.0% in patients presenting a RVT ≥2 cm vs. 0.1-1.9 vs. no RVT, respectively. When only Milan Criteria-IN patients were analysed, similar results were reported, with 5-year disease-free survival rates of 58.1%, 79.0% and 94.0% in patients presenting a RVT ≥2 cm vs. 0.1-1.9 vs. no RVT, respectively. RVT is an important determinant of tumour recurrence after liver transplantation performed for hepatocellular cancer. Its discriminative power looks to be evident also in a Milan-IN setting, suggesting to more liberally use locoregional treatments also in these patients