Risk factors and outcomes of restorative proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis. Retrospective study of 75 single center cases.

OBJECTIVE: Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical gold standard in patients with ulcerative colitis (UC). Results are generally satisfactory but there is a significant rate of patients who experience postoperative complications. The aims of our study were to identify the pre- and intraoperative risk factors and their correlation with the reported outcomes. PATIENTS AND METHODS: A retrospective study was conducted on the medical records of all consecutive patients undergoing restorative proctocolectomy with IPAA for UC in our center from 2010 to 2021. Pre- and intraoperative factors were examined and correlated with pouchitis, endoscopic pouchitis, pouch failure, anastomotic leak, postoperative complications classified according to Clavien-Dindo score and stoma outlet obstruction. A univariate and multivariate statistical analysis was performed. RESULTS: Out of 75 patients undergoing 3- or 2-stage IPAA surgery, the coexistence of extraintestinal clinical manifestations and preoperative topical rectal stump therapy for active proctitis were significantly associated with the occurrence of pouchitis (OR=4.4, p=0.03 and OR=7.6, p=0.01). Endoscopic pouchitis was found to be related to preoperative topical rectal therapy (OR=10.2, p=0.007), but not to extraintestinal manifestations of disease. Anastomotic leak was found to be significantly related to pouch failure (OR=22.7, p=0.007). Surgical indication for malignancy increased the risk for early complications (Clavien-Dindo >2) (OR=16.0, p=0.04). Young age was associated with the occurrence of outlet stoma obstruction in patients with recent IPAA surgery (OR=0.97, p=0.05). CONCLUSIONS: Based on observed results, an appropriate preoperative patient assessment aimed at detecting specific risk factors is crucial to identify early or prevent worse outcomes in patients undergoing IPAA surgery.

The impact of COVID-19 pandemic on IBD surgery: a single center experience.

OBJECTIVE: The spread of COVID-19 pandemic forced the national healthcare system to reorganize almost all surgical services, in order to maintain an adequate therapeutic offer. At General Surgery department of Fondazione Policlinico Gemelli in Rome, surgical procedures were progressively reduced to provide beds and personnel for COVID-19. The aim of our study was to analyze the effect of one year of COVID-19 pandemic on Inflammatory Bowel Disease (IBD) surgery in a cohort of patients and evaluate post-operative short-term complications. PATIENTS AND METHODS: Our team retrospectively analyzed the records of IBD patients who were referred to an IBD-related resective surgery from January 2020 to December 2020. These patients were compared to a comparable group of IBD patients who were operated from January 2019 to December 2019. RESULTS: A total of 160 patients were included in the study. Median age was 44 (range 15-77). Patients were referred for Ulcerative colitis (23.1%) and Crohn's disease (76.9%). Eighty-three patients underwent surgery from January 2020 to December 2020, which constitutes a 4.6% increase in the number of patients compared to the same period in 2019. Median post-operative hospital stay increased (7 days in 2019 vs. 6 days in 2020). Laparoscopic was the most frequently performed procedure during both periods (49% in 2019 and 59% in 2020). Complication rates, reported as Clavien-Dindo score 3 or 4, slightly decreased in 2020 (6.5 in 2019 vs. 4.8 in 2020). PCR test for detection of COVID-19 infection was conducted in all the patients before the hospitalization. Two patients out of 70 were tested positive for COVID-19 and their surgeries were rescheduled. CONCLUSIONS: There was no significant reduction in IBD resective surgeries at our center in 2020, nor a deterioration of the outcomes. A reduction of other elective surgical procedures had to be carried out and adequate protective measures for both patients and healthcare workers were established.

Hydrogen-bond network distortion of water in the soft confinement of Nafion membrane.

A Compton spectroscopy investigation is carried out in hydrated Nafion membranes, enabling identification of distortions in the hydrogen-bond distribution of the polymer hydrating water by means of the subtle changes reflected by the Compton profiles. Indeed, deformations of the Compton profiles are observed when varying hydration, and two different bonding kinds are associated with the water molecules: at low hydration, water surrounds the sulfonic groups, while on increasing hydration, water molecules occupy the interstitial cavities formed upon swelling of the membrane. The analysis is proposed in terms of averaged OH bond length variation. A sizable contraction of the OH distance is observed at low hydration (∼0.09 Å), while at higher hydration levels, the contraction is smaller (∼0.02 Å) and the OH bond length is closer to bulk water. An evaluation of the electron kinetic energy indicates that the spatial changes associated with the water distribution correspond to a consistent binding energy increase. Distinct temperature dependences of each water population are observed, which can be straightly related to water desorption into ice on cooling below the freezing point.

New perspectives in the prediction of postoperative complications for high-risk ulcerative colitis patients: machine learning preliminary approach.

OBJECTIVE: Patients with acute severe and medical refractory ulcerative colitis have a high risk of postoperative complications after total abdominal colectomy (TAC). The objective of this retrospective study is to use machine learning to analyze and predict short-term outcomes. PATIENTS AND METHODS: 32 patients with ulcerative colitis were treated with total abdominal colectomy between 2011 and 2017. Biographical data, preoperative therapy, blood chemistry, nutritional status, surgical technique, blood transfusion and preoperative length of stay were the features selected for the statistical analyses and were used as input for the machine learning algorithms to predict the rate of complications. RESULTS: Traditional statistical analysis showed an overall postoperative morbidity rate of 34% and a mortality rate of 3%. Preoperative low serum albumin levels (<2.5 g/dL) were related to a higher risk of minor infectious complications with statistical significance (p<0.05). Preoperative length of stay (>4 days), blood transfusions (≥1 unit) and body temperature (≥37.5°C) demonstrated a major impact on infectious morbidity with statistical significance (p<0.05). Patients treated with steroids and rescue therapy presented a higher risk of minor infectious complications (p<0.05). Evaluating only preoperative features, machine learning algorithms were able to predict minor postoperative complications with a high strike rate (84.3%), high sensitivity (87.5%) and high specificity (83.3%) during the testing phase. CONCLUSIONS: Machine learning is demonstrated to be useful in predicting the rate of minor postoperative complications in high-risk ulcerative colitis patients, despite the small sample size. It represents a major step forward in data analysis by implementing a retrospective study from a prospective point of view.

Total hip replacement: a retrospective multicentric analysis on re-intervention rate after single component revision.

Total hip arthroplasty (THA) revision is a procedure consisting in the replacement of a single or multiple implant components and could take place once or more times (re-revision). The aim of this multicentre study is to evaluate the benefits of single component revision in respect of the principles that define implant stability. Two hundred and forty-two patients underwent THA revision at Orthopaedic Clinic of Pisa and Versilia (ITA) from January 2007 to December 2016. We have systematically excluded revisions due to septic or traumatic prosthesis loosening, revisions of both implant components (cotyle and stem) and replacement alone. To evaluate implant stability, we used preoperative X ray and intra-operative mechanical stress tests, applying accredited criteria. Two hundred and twenty-six patients (93%) underwent a single procedure of THA revision: 193 had cotyle replacement and 33 had femoral stem replacement. The remaining 16 (7 %) underwent at least two procedures: 10 of them had consecutive failure of the same component, while the other 6 had revision of the other component after the first procedure. Considering our cases series, we can assert that single component revision is the best choice when no signs of loosening are present on the remaining component. Nevertheless, an accurate evaluation with unanimous radiological criteria and intraoperative testing is essential for the surgeon to choose the most suitable treatment.

Is minimally-invasive spinal surgery a reliable treatment option in symptomatic spinal metastasis?

OBJECTIVE: Up to 70% of patients with cancer are likely to develop spine metastasis. Radiation therapy is the standard of care for painful spinal metastases in absence of unstable or impending fractures. More frequently these patients require open palliative surgery for pain, vertebral collapse and neurological deficits. Minimally Invasive Spine Surgery (MISS) techniques using percutaneous pedicle screw fixation may be considered as an alternative to open surgery in selected cases. MISS techniques are thought to be associated with fewer tissues damages resulting in early pain relief,  they also allow for early mobilization and optimization of function. PATIENTS AND METHODS: From 2011 to 2018, 52 patients affected by spinal metastasis were treated with MISS techniques in Rizzoli Orthopaedic Institute of Bologna and in Cisanello Hospital of Pisa, Italy. All patients underwent percutaneous pedicle screw fixations (PPSF) coupled with mini-decompressions in case it was required by spinal cord compressions. All patients were evaluated pre and post-operatively by Frenkel classification and VAS scores. RESULTS: Mean follow-up time was 19,4 months. Preoperatively, Frankel scores were E in 37 patients, D3 in 6 patients, D2 in 3 cases, D1 in 3 patients, B in one patient and C in two. The Frankel score improved in 10 patients, remained stable in 40 patients and worsened in two patients. Preoperatively, the mean VAS score in 29 patients treated with PPSF procedure with spinal decompression was 7, while postoperatively, it became 5. In 23 patients who underwent only PPSF procedure without spinal decompression mean VAS score was 5, postoperatively it became 3. CONCLUSIONS: In selected cases, MISS surgeries may be considered as a valid alternative to open surgery. Although the efficacy of PPSF has been well documented in trauma or degenerative spine surgery, there is not sufficient literature about MISS techniques in spinal metastasis and further studies are needed to elucidate the most appropriate patient in which this approach could represent the gold standard of treatment.

Ultrafast Plasmon Dynamics in Crystalline LiF Triggered by Intense Extreme UV Pulses.

An extreme ultraviolet pump and visible-light probe transmission experiment in crystalline LiF, carried out at the Free Electron Laser facility FERMI, revealed an oscillating time dependence of the plasmon mode excited in the high-density high-temperature electron plasma. The effect is interpreted as a fingerprint of the electron-ion interaction: the ion motion, shaped by the electron dynamic screening, induces, in turn, electron density fluctuations that cause the oscillation of the plasmon frequency at the timescale of the ion dynamics. Fitting the high resolution transmission data with an RPA model for the temperature-dependent dielectric function, which includes electron self-energy and electron-ion coupling, confirms the interpretation of the time modulation of the plasmon mode.

Polymorphism of human telomeric quadruplexes with drugs: a multi-technique biophysical study.

The human telomeric G-quadruplex structural motif of DNA has come to be known as a new and stimulating target for anticancer drug discovery. Small molecules that interact with G-quadruplex structures in a selective way have gained impressive interest in recent years as they may serve as potential therapeutic agents. Here, we show how circular dichroism, UV resonance Raman and small angle X-ray scattering spectroscopies can be effectively combined to provide insights into structural and molecular aspects of the interaction between human telomeric quadruplexes and ligands. This study focuses on the ability of berberine and palmatine to bind with human telomeric quadruplexes and provides analysis of the conformational landscape visited by the relevant complexes upon thermal unfolding. With increasing temperature, both free and bound G-quadruplexes undergo melting through a multi-state process, populating different intermediate states. Despite the structural similarity of the two ligands, valuable distinctive features characterising their interaction with the G-quadruplex emerged from our multi-technique approach.

Single-use, patient-specific instrumentation technology in knee arthroplasty: a comparative study between standard instrumentation and PSI efficiency system.

Patient-specific instrumentation is a surgical technique that was created to improve the accuracy of implantation, surgical time and workflow in total knee arthroplasty. This study is a single-center, single-surgeon randomized clinical trial. The aim of this work was to evaluate clinical efficacy of PSI versus standard surgical instrumentation in malalignment risk and blood loss reduction. From April 2015 to September 2016, 40 patients for a total of 40 knees were included in the randomization process. Each patient underwent CT scan of the lower limb including hip, knee and ankle joint with the realization of the PSI system and the TKA with Medacta GMK Primary®. Patients were evaluated 1 month after surgery with X-ray and after 2 months with clinical examination and assessment by Knee Society Score (KSS). Blood loss was detected by adding the values calculated in the operative room and the blood loss in the vacuum systems. In the study group, mean value of KSS was 85.2 (IC 95% 81.2-88.5), mean blood loss was 657 ml (IC 95% 580.6-735.4), and mean value of femorotibial angle was 178.8° (IC 95% 178.5-179.3). In the control group, mean value of KSS was 87.2 (IC 95% 85.3-89.4), mean blood loss was 866.5 ml (IC 95% 763.3-972.5), and mean value of femorotibial angle was 178.9°(IC 95% 177.6-180.3). The Student t test detected a significant difference in blood loss between groups (p < 0.05), and no differences were found between KSS. The single-use instrumentation should improve precision, operative time, turnover time, sterilization and maintenance costs and could help to reduce infection risks. Our results confirm only the improvement on reducing blood loss. In our opinion, this technique should be used in selected patients when the surgeon could have some difficulties to perform femoral cuts on coronal plane or when patients need to have a very little blood loss due to other conditions.

Disentangling time-focusing from beam divergence: A novel approach for high-flux thermal neutron spectroscopy at continuous and long-pulse sources.

We present the concept of a novel time-focusing technique for neutron spectrometers, which allows us to disentangle time-focusing from beam divergence. The core of this approach is a double rotating-crystal monochromator that can be used to extract a larger wavelength band from a white beam, thus providing a higher flux at the sample compared to standard time-of-flight instruments, yet preserving energy resolution and beam collimation. The performances of a spectrometer based on this approach are quantitatively discussed in terms of possible incident wavelengths, flux at the sample, and (Q, E)-resolution. Analytical estimates suggest flux gains of about one order of magnitude at comparable resolutions in comparison to conventional time-of-flight spectrometers. Moreover, the double monochromator configuration natively shifts the sample away from the source line-of-sight, thus significantly improving the signal-to-noise ratio. The latter, in combination with a system that does not increase the beam divergence, brings the further advantage of a cleaner access to the low-Q region, which is recognized to be of fundamental interest for magnetism and for disordered materials, from glasses to biological systems.

Cryotherapy efficacy and safety as local therapy in surgical treatment of musculoskeletal tumours. A retrospective case series of 143 patients.

Cryotherapy, also called Cryoablation (CA), is a technique that provides a local treatment to various pathological conditions. In Musculoskeletal tumours management, Cryoablation is well accepted and validated as a treatment in palliative cures for metastatic patients. Recently, CA has been proposed also as an alternative to radiofrequency ablation in osteoid osteoma and other benign tumour treatment with promising results. Cryotherapy with argon ice-balls as local adjuvant in open surgery is a tool that can provide enlargement of surgical margins if used properly. There is still not enough evidence supporting use of cryotherapy as local adjuvant in Musculoskeletal open surgery as the series cited above are very small and there is no comparative RCT between local adjuvant therapies including CA. One-hundred-and-eighty-three patients were treated with Cryoablation from 2000 and 2018 in the Musculoskeletal Tumours Surgery Unit of Careggi (Florence) and the University 2nd Clinic of Pisa. In our study group, 38 patients (26.6%) were affected by bone metastasis, 16 patients (11.1%) by aneurismal bone cysts or angiomas, 22 patients (15.4%) by low-grade malignant musculoskeletal tumours, 2 patients (1,4%) by fibromatosis, 63 patients (44.1%) by benign musculoskeletal tumours (principally Giant Cell Tumours-GCT) and 2 patients (1.4%) by Osteosarcomas. In 125 cases (87.4%), CA has been used as an adjuvant therapy, in 12 cases (8.4%) as a percutaneous ablation therapy and in 6 cases (4.2%) as adjuvant to remove tumoral lesions 'en bloc' or as a 'poor technique' for its sterilizing effect on previously resected bones. Mean follow-up was 10 years. Twenty-three patients (16%) were classified as Alive with Disease (AWD) due to local recurrence or tumour progression (14 metastases, 5 low-grade malignant bone tumours, 4 Giant Cell Tumours). Eight patients died due to the disease (6 metastases, 2 osteosarcomas), while 1 died from leukaemia. One-hundred-and-eleven patients (78%) were classified as Continues Disease Free (CDF). All patients reported decrease in pain-related symptoms after surgery and all surgeons reported better control of blood loss. Three cases (2%) of local skin necrosis or wound dehiscence were reported. No local recurrences were reported after fibromatosis ablation. Our results confirm that CA could be considered as a safe and effective technique to treat various conditions as adjuvant and palliative therapy. In particular, in open surgery, cryotherapy as an adjuvant treatment could lead to very low rates of recurrence in locally aggressive tumours like Giant Cell Tumours. These results could be generalized but a better understanding about indications and outcomes can be reached studying CA in specific populations with comparation to other adjuvant techniques.

Complications and survival of megaprostheses after resection of bone metastases.

Treatment of bone metastases is often palliative, aiming at pain control and stabilization or prevention of pathological fractures. However, a complete resection with healing purposes can be performed in selected cases. The aim of our work was to evaluate the survival of megaprostheses used for reconstruction after bone metastases. Between January 2001 and March 2015, we implanted 169 Megasystem-C® (Waldemar LINK® GmbH & Co. KG, Hamburg, Germany) after bone metastasis resection. Patients, 95 females and 74 males, were operated at an average age of 61 (12-87) years for proximal femoral resection in 135 (79.9%) cases, distal femur in 24 (14.2%), proximal tibia in 6 (3.6%), total femur in 3 (1.8%) and intercalary femur in 1 (0.6%). Mostly, breast cancer metastases (30.8%), kidney (17.8%) and lung (14.2%) were treated. At an average follow-up of 21 (1-150) months, we found a 99.4% overall limb salvage and a 96.1% overall survival rate at 1 year, 92.8% at 2 years, and 86.8% at 5 and 10 years. We found 9 (5.3%) mobilization cases of the proximal femoral implant, 3 needed surgical reduction; 2 (1.2%) cases of aseptic loosening of the prosthetic stem; 2 (1.2%) periprotetic infection cases, one requiring a 2-stage revision. Few literature studies have evaluated the survival of megaprosthetic implant in the treatment of bone metastases. Our data show how in this specific context the rate of complications is significantly lower than expected in general orthopedic orthopedic surgery. The use of modular prostheses is a valid reconstructive strategy after bone metastasis resection in selected patients. The rate of short-term complications is exceptionally low; further studies will have to confirm this in the longer term.

A high-flux upgrade for the BRISP spectrometer at ILL.

To date, the BRISP spectrometer represents the state-of-the-art for every instrument aiming to perform Brillouin neutron scattering. Exploiting accurate ray-tracing McStas simulations, we investigate an improved configuration of the BRISP primary spectrometer to provide a higher flux at the sample position, while preserving all the present capabilities of the instrument. This configuration is based on a neutron guide system and is designed to fit the instrument platform with no modifications of the secondary spectrometer. These evaluations show that this setup can achieve a flux gain factor ranging from 3 to 6, depending on the wavelength. This can expand the experimental possibilities of BRISP towards smaller samples, possibly using also complex sample environments.

Real-time observation of the isothermal crystallization kinetics in a deeply supercooled liquid.

Below the melting temperature Tm, crystals are the stable phase of typical elemental or molecular systems. However, cooling down a liquid below Tm, crystallization is anything but inevitable. The liquid can be supercooled, eventually forming a glass below the glass transition temperature Tg. Despite their long lifetimes and the presence of strong barriers that produces an apparent stability, supercooled liquids and glasses remain intrinsically a metastable state and thermodynamically unstable towards the crystal. Here we investigated the isothermal crystallization kinetics of the prototypical strong glassformer GeO2 in the deep supercooled liquid at 1100 K, about half-way between Tm and Tg. The crystallization process has been observed through time-resolved neutron diffraction for about three days. Data show a continuous reorganization of the amorphous structure towards the alpha-quartz phase with the final material composed by crystalline domains plunged into a low-density, residual amorphous matrix. A quantitative analysis of the diffraction patterns allows determining the time evolution of the relative fractions of crystal and amorphous, that was interpreted through an empirical model for the crystallization kinetics. This approach provides a very good description of the experimental data and identifies a predator-prey-like mechanism between crystal and amorphous, where the density variation acts as a blocking barrier.

PATHOLOGIC AND IMPENDING FRACTURES: BIOLOGICAL AND CLINICAL ASPECTS.

Bone metastases from carcinomas are epidemiologically rising because of the increased survival rate of oncologic patients, related to several factors such as improvement of primary and secondary screening, advancement of medical research and technology and the better understanding of mechanisms underlying bone metastases origination from primary tumor. Skeletal Related Events (SREs) can seriously affect quality of life in patients with metastatic disease. These events include the necessity of radiotherapy or bone surgery, malignant hypercalcemia, pathologic fractures and spinal cord compression. Among the SREs, pathologic fractures are the most disabling events and represent an emergency in these delicate patients. A pathologic fracture is defined as a fracture that occurs at the level of a pre-existing bone lesion (that is often a tumor), spontaneously or as the result of low-energy trauma (1). The pre-existence of the metastatic lesion in the bone, its evaluation and the assessment of progression can make these complications predictable and preventable. Pathologic fractures imply several severe consequences, including patient immobilization (in the case of fractures involving the lower limbs), loss of autonomy, anaemia, need of blood transfusion, discontinuation of medical therapies or radiotherapy and protracted hospitalization. Secondary effects of prolonged immobilization and loss of autonomy further lengthen this list of complications in patients who are already significantly limited in their activities. In the present paper, the authors present a review on the main aspects involved in bone metastastic disease: biology, quality of life, economic impact and survival.

Hydration-dependent dynamics of human telomeric oligonucleotides in the picosecond timescale: a neutron scattering study.

The dynamics of the human oligonucleotide AG3(T2AG3)3 has been investigated by incoherent neutron scattering in the sub-nanosecond timescale. A hydration-dependent dynamical activation of thermal fluctuations in weakly hydrated samples was found, similar to that of protein powders. The amplitudes of such thermal fluctuations were evaluated in two different exchanged wave-vector ranges, so as to single out the different contributions from intra- and inter-nucleotide dynamics. The activation energy was calculated from the temperature-dependent characteristic times of the corresponding dynamical processes. The trends of both amplitudes and activation energies support a picture where oligonucleotides possess a larger conformational flexibility than long DNA sequences. This additional flexibility, which likely results from a significant relative chain-end contribution to the average chain dynamics, could be related to the strong structural polymorphism of the investigated oligonucleotides.

Collective ion dynamics in liquid zinc: evidence for complex dynamics in a non-free-electron liquid metal.

A detailed inelastic neutron scattering investigation of the THz dynamics of liquid zinc is presented. The observed Q dependence clearly reveals the existence of a complex dynamics made up of two distinct excitations. The highest energy mode is the prolongation of the longitudinal acoustic density fluctuations whereas the comparison with the phonon dynamics of crystalline hcp zinc suggests a transverse acousticlike nature for the second one. This mode seems related to peculiar anisotropic interactions, possibly connected to the behavior of the crystalline phase.

Structural evolution and medium range order in permanently densified vitreous SiO2.

Positron annihilation lifetime spectroscopy is employed to measure the size of the interstitial void spaces characterizing the structure of a set of permanently densified SiO2 glasses. The average volume of the voids is markedly affected by the densification process and linearly shrinks by almost an order of magnitude after a relative density variation of 22%. In addition, x-ray diffraction shows that this change of density does not modify appreciably the short range order, which remains organized in SiO4 tetrahedra. These results strongly suggest a porous medium description for v-SiO2 glasses where the compressibility and the medium range order are dominated by the density variation of the voids volume up to densities close to that of α-quartz.

Terahertz Dynamics in Human Cells and Their Chromatin.

The terahertz dynamics of human cells of the U937 line and their chromatin has been investigated by high-resolution inelastic X-ray scattering. To highlight its dynamical features in situ, nuclear DNA has been stained by uranyl-acetate salt. The general behavior of the collective dynamics of the whole cell is quite similar to that of bulk water, with a nearly wavevector-independent branch located at about 5 meV and a propagating mode with a linear trend corresponding to a speed of sound of 2900 ± 100 m/s. We provide the first experimental evidence for the existence of two branches also in the dispersion curves of chromatin. The high-energy mode displays an acoustic-like behavior with a sound velocity similar to unstained cells, but in this case the branch likely originates from the superposition of intramolecular DNA optic modes. A low-energy optic-like branch, distinctive of the chromatin moiety, is found at about 2.5 meV.