Is there a role for surgical resection in patients with pancreatic cancer with liver metastases responding to chemotherapy?

BACKGROUND: New chemotherapeutic regimens have improved survival for stage IV pancreatic ductal adenocarcinoma and occasionally major response of liver metastases can be observed. Aim of this work is to analyze the outcomes of patients undergoing primary chemotherapy for liver metastases from pancreatic cancer and to evaluate the results of surgical resection. METHODS: Retrospective analysis. EXCLUSION CRITERIA: patients with extra-hepatic metastases, patients with Eastern Cooperative Oncology Group performance status ≥3, patients undergoing supportive care alone. RESULTS: 127 patients were identified. Liver metastases were unilobar in 28.5% of patients. Chemotherapy regimens included gemcitabine alone or in association with other agents (44%), oxaliplatin, irinotecan, fluorouracil and leucovorin (FOLFIRINOX 8%), and cisplatin, gemcitabine plus capecitabine and epirubicin (PEXG) or capecitabine and docetaxel (PDXG) or epirubicin and fluorouracil (PEFG) (48%). 56 patients (44%) had a complete (7%) or partial response (37%). surgical resection was carried out in 11 patients (8.5%). Median overall survival was 11 months for the entire cohort and 15 months for those with partial/complete response. In this sub-group median survival was significantly longer (46 versus 11 months) for patients undergoing resection (P < 0.0001). Independent predictors of overall survival were chemotherapy with multiple agents (HR: 0.512), surgical resection (HR: 0.360), >5 liver metastases at diagnosis (HR: 3.515), and CA 19.9 reduction < 50% of baseline value (HR: 2.708). CONCLUSIONS: Surgical resection of primary pancreatic tumor with or without residual liver disease can be considered in selected cases after primary chemotherapy and it is associated with improved survival.

Reconstruction of medial patello-femoral ligament: Comparison of two surgical techniques.

The medial patello-femoral ligament is considered the most important passive patellar stabilizer and its proper functionality is essential for the patello-femoral joint stability. In this work, 18 human knees were randomly divided into two groups and reconstructed through two different surgical techniques: the "Through tunnel tendon" and the "Double converging tunnel" reconstructions. Subsequently, the samples were mechanically tested to evaluate the structural properties of reconstructed femur-MPFL-Patella complex (rFMPC). Particular attention was given to maintain the anatomical orientation between the patella and the graft. Both procedures showed lower stiffness and higher ultimate strain and absorbed energy compared to the native MPFL, but the advantages of the double converging tunnel technique are related to the restoration of the native MPFL sail-shape, to a better stress distribution on the patella, to the use of a single interference screw as fixation device and to the simplicity, rapidity and cost-effectivity of the surgical procedure. The evaluation of the structural properties of rMPFL is fundamental to evaluate the adequacy of the different techniques to restore the physiological structural properties of the native MPFL.

Biomechanical evaluation of medial patello-femoral ligament reconstruction: comparison between a double-bundle converging tunnels technique versus a single-bundle technique.

BACKGROUND: Several MPFL reconstructions are commonly performed for recurrent patellar dislocation, but misleading data are currently available in the literature on the ability of the different techniques to re-create a functioning ligament. MATERIALS AND METHODS: In this study, we showed the biomechanical properties of two different procedures for MPFL reconstruction using a natural orientation during uniaxial tensile testing. Eighteen fresh-frozen human knees were randomly assigned to two groups of nine each. In the group A, the reconstruction was performed using a double converging tunnels technique and in the group B was used a single-tunnel technique with semitendinosus autograft. The specimens were loaded in natural orientation using an Instron tensile test machine, and the stiffness and ultimate load were determined. RESULTS: The ultimate load was 213 ± 90 and 171 ± 51 N using our double-bundle technique (group A) and the single-bundle technique (group B), respectively. One (11 %) specimen failed at the patellar side due to patellar fracture in the group B. There was no statistical significant difference (p > 0.05) between the two groups in terms of stiffness and ultimate load. CONCLUSION: This study is the first biomechanical evaluation of the MPFL reconstructions in natural orientation. Both the procedures achieved safe fixation of the graft at the femoral attachment; however, the single-bundle technique reported 11 % of failure at the patellar side due to patellar fracture. In addition, the double-bundle technique can better restore the anatomy of the native ligament.

Material and structural tensile properties of the human medial patello-femoral ligament.

The medial patellofemoral ligament (MPFL) is considered the most important passive patellar stabilizer and acts 50-60% of the force of the medial soft-tissue which restrains the lateralization of the patella between 0° and 30°. In this work, 24 human knees have been tested to evaluate the material properties of MPFL and to determine the structural behavior of femur-MPFL-Patella complex (FMPC). Particular attention was given to maintain the anatomical orientation between the patella and MPFL and to the evaluation of the elongation during the mechanical tests. The ultimate stress of the isolated ligament was 16±11MPa, the ultimate strain was 24.3±6.8%, the Young׳s Modulus was 116±95MPa and the strain energy density was 2.97±1.69MPa. The ultimate load of the whole structure, FMPC, was 145±68N, the ultimate elongation was 9.5±2.9mm, the linear stiffness was 42.5±10.2N/mm and the absorbed energy was 818.8±440.7Nmm. The evaluation of material and structural properties of MPFL is fundamental to understand its contribution as stabilizer and for the selection of repair and reconstruction methods.

Groin Pain Syndrome Italian Consensus Conference on terminology, clinical evaluation and imaging assessment in groin pain in athlete.

The nomenclature and the lack of consensus of clinical evaluation and imaging assessment in groin pain generate significant confusion in this field. The Groin Pain Syndrome Italian Consensus Conference has been organised in order to prepare a consensus document regarding taxonomy, clinical evaluation and imaging assessment for groin pain. A 1-day Consensus Conference was organised on 5 February 2016, in Milan (Italy). 41 Italian experts with different backgrounds participated in the discussion. A consensus document previously drafted was discussed, eventually modified, and finally approved by all members of the Consensus Conference. Unanimous consensus was reached concerning: (1) taxonomy (2) clinical evaluation and (3) imaging assessment. The synthesis of these 3 points is included in this paper. The Groin Pain Syndrome Italian Consensus Conference reached a consensus on three main points concerning the groin pain syndrome assessment, in an attempt to clarify this challenging medical problem.

Quasi-linear viscoelastic properties of the human medial patello-femoral ligament.

The evaluation of viscoelastic properties of human medial patello-femoral ligament is fundamental to understand its physiological function and contribution as stabilizer for the selection of the methods of repair and reconstruction and for the development of scaffolds with adequate mechanical properties. In this work, 12 human specimens were tested to evaluate the time- and history-dependent non linear viscoelastic properties of human medial patello-femoral ligament using the quasi-linear viscoelastic (QLV) theory formulated by Fung et al. (1972) and modified by Abramowitch and Woo (2004). The five constant of the QLV theory, used to describe the instantaneous elastic response and the reduced relaxation function on stress relaxation experiments, were successfully evaluated. It was found that the constant A was 1.21±0.96MPa and the dimensionless constant B was 26.03±4.16. The magnitude of viscous response, the constant C, was 0.11±0.02 and the initial and late relaxation time constants τ1 and τ2 were 6.32±1.76s and 903.47±504.73s respectively. The total stress relaxation was 32.7±4.7%. To validate our results, the obtained constants were used to evaluate peak stresses from a cyclic stress relaxation test on three different specimens. The theoretically predicted values fit the experimental ones demonstrating that the QLV theory could be used to evaluate the viscoelastic properties of the human medial patello-femoral ligament.

Anatomy of the Medial Patello-Femoral Ligament: a systematic review of the last 20 years literature.

BACKGROUND: Although many studies have investigated the anatomy of the Medial Patello-Femoral Ligament (MPFL), some studies have even questioned its existence. In the last 20 years, there is a renewed interest on the role of the MPFL in patello-femoral instability. As a result, several studies have been published that describe the anatomy, function and possible surgical reconstruction of the MPFL. Despite the large amount of literature produced, there is still a lack of consensus on what is its real anatomy as there are currently no systematic reviews on this topic. PURPOSES: Thus, the aim of this review is to systematically report the results in literature regarding in anatomical papers, the existence, size, insertion sites and relationships of this ligament with the other medial structures of the knee. METHODS: We have systematically analyzed anatomical studies currently available in literature between 1980 and December 2012. The search was carried out on Medline, Embase, Cochrane Library and Google Scholar. We checked reference lists of articles, reviews and textbooks identified by the search strategy for other possible relevant studies. RESULTS: The outcomes examined are the presence of the ligament, its size (length, width, thickness), and its patellar and femoral insertions. A total of 312 cadaveric knees were included in the 17 studies; the MPFL was identified in 99% of cases (309). CONCLUSIONS: The consensus is that the MPFL is almost always present in the dissected knees. The size and insertions of the ligament demonstrate great variation between cadavers. LEVEL OF EVIDENCE: Systematic review of anatomical study, Level 1.

Shape and size of the medial patellofemoral ligament for the best surgical reconstruction: a human cadaveric study.

PURPOSE: The aim of this study was to investigate the shape and the attachments of the medial patellofemoral ligament (MPFL) in cadaver specimens to determine an anatomical basis for the best MPFL reconstruction. METHODS: Twenty fresh-frozen knees were used. Dissection protocol implied performing dissections from within the knee joint. We investigated the shape and the attachments between the MPFL and the quadriceps tendon, the patellar and femur insertions, and all the other relationships with the medial soft tissues of the knee. RESULTS: The distal fibers of MPFL were interdigitated with the deep layer of the medial retinaculum. All isolated ligament had a sail-like shape with the patellar side bigger than the femoral side. The femoral insertion, distinct both from medial epicondyle and adductor tubercle, was located at 9.5 mm (range 4-22) distal and anterior respect to adductor tubercle and proximal and posterior to epicondyle. The medial third of the thickness of patella was involved in the insertion. The proximal third of the patella is always involved in the MPFL attachment; in 45% of the cases, it was extended to the medial third and in one case, an extension at the distal third was found. Additionally in 35% (7 cases), it extended to the quadriceps tendon and it were inconstantly attached at the vastus medialis obliques (VMO) tendon and at the vastus intermedius (VI) tendon in an aponeurotic structure. CONCLUSIONS: The MPFL is a distinct structure that goes from patella to femur with a sail-like shape; its patellar insertion, that mostly occur via an aponeurosis tissue with VMO and VI, is at the proximal third of the patella but it may extend in some cases to the medial third patella or to the quadriceps tendon, or very rarely to the distal third of the patella. In the femoral side, the MPFL is inserted in its own site, in most cases distinct both from epicondyle and adductor tubercle, located on average at a 9.5 mm distance distally and anteriorly in respect to the adductor tubercle. Its lower margin was difficult to define. Given the importance of this structure, it must be reconstructed as anatomically as possible in its insertion and in its shape. Many attempts have been made to make functional reconstructions with less than excellent results.

Simultaneous determination of acidic and non-acidic pesticides in natural waters by liquid chromatography-mass spectrometry.

There is increasing interest and demand for real multi-residue methods able to simultaneously determine pesticides with a broad spectrum of chemical characteristics in environmental and biological matrices. A method based on solid-phase extraction with a Carbograph 4 cartridge and liquid chromatography with electrospray mass spectrometry (LC-ES-MS) enabling simultaneous determination of non-acidic and acidic pesticides in real water samples is described. On repeatedly (n=5) extracting 4 l of drinking water (spike level 50 ng/l), 2 l of ground water (spike level 100 ng/l) and 1 l of river water (spike level 200 ng/l), recovery of 26 base/neutral pesticides and 13 acidic pesticides were equal to or better than 80%, except for carbendazim (67%), butocarboxim (73%), aldicarb (75%) and molinate (77%). Relative standard deviations ranged between 4 and 15%. Final extracts containing acidic and non-acidic pesticides were analyzed in a single chromatographic run while the ES-MS system was operated in both positive and negative ion modes. With the aim of finding the best operating conditions, in terms of sensitivity, the pH of the LC eluent was varied in the 2.9-8.4 range. Altogether, the best results were obtained by using an LC eluent containing 1 mmol/l formic acid. Over the entire pH range considered, well shaped peaks for both basic and acidic analytes were achieved by the use of a new generation LC column. By extracting selected ion current profiles from the total ion current mass chromatogram relative to analysis of 4 l of drinking water spiked with 50 ng/l of each of the 39 analytes, estimated limits of detection ranged between 0.05 and 1.5 ng/l, except for propyzamide (8 ng/l) and 2,4-DB (3 ng/l).

The ejector-loop fermenter: Description and performance of the apparatus.

A novel fermentation unit, the ejector-loop fermenter (ELF), consisting of an outer-loop tower fermenter, a centrifugal pump, a plate-heat exchanger, and a gas-liquid ejector, was designed and constructed. Aeration was achieved by continuously recirculating the fermentation medium through two different nozzle devices instead of using the traditional expensive air compressor. By carrying out a whey fermentation with Kluyveromyces fragilis as the test organism, either in the ELF or in conventional stirred fermenter, it was possible to confirm that the high sheat streses and mixing shock occurring in the ejector nozzle and diffuser sections did not affect microbial growth. Within the range of experimental power consumption per unit volume (-0.1-5 kW/m(3)), the oxygen transfer capability of the ELF per unit power input was found to vary from 1 to 2.5 kg O(2) kW(-1)h(-1). Moreover, it is shown that there is suficient room for improvement in the performance of the ELF unit by care fully designing the aeration device. In fact, at constant volumetric oxygen transfer coefficient, the power consumpotion per unit volume in a 4-mm nozzle was found to be about 40% less than that in a 6-mm nozzle.