Environmental assessment of a two-stage high pressure anaerobic digestion process and biological upgrading as alternative processes for biomethane production.

Biomethane plays a key role in achieving decarbonization and sustainable development goals. According to the objectives that arise, choosing the most suitable production system allows optimization of production, thereby reducing CO2 emissions. In this study, three biomethane production scenario life cycle assessments were compared to determine which would maintain the lowest CO2 emissions. Conventional anaerobic digestion and an innovative process called two-stage high pressure anaerobic digestion were considered. These methods were combined with two upgrading processes: water scrubbing and biological upgrading. Cattle manure and sugar beets were used as substrates for the process. Emissions were 805.6 gCO2eq/m3CH4 for the traditional biogas production process combined with water scrubbing and 450.3 gCO2eq/m3CH4 for the two-stage anaerobic digestion process combined with biological upgrading. Furthermore, the analysis demonstrated that these values would be reduced by 29.5 % and 48.0 % if electrical energy were produced using only renewable energy sources.

Quantitative assessment of the impact of COVID-19 pandemic on pancreatic surgery: an Italian multicenter analysis of 1423 cases from 10 tertiary referral centers.

Few evidences are present on the consequences of coronavirus disease 2019 (COVID-19) pandemic on pancreatic surgery. Aim of this study is to evaluate how COVID-19 influenced the diagnostic and therapeutic pathways of surgical pancreatic diseases. A comparative analysis of surgical volumes and clinical, surgical and perioperative outcomes in ten Italian referral centers was conducted between the first semester 2020 and 2019. One thousand four hundred and twenty-three consecutive patients were included in the analysis: 638 from 2020 and 785 from 2019. Surgical volume in 2020 decreased by 18.7% (p < 0.0001). Benign/precursors diseases (- 43.4%; p < 0.0001) and neuroendocrine tumors (- 33.6%; p = 0.008) were the less treated diseases. No difference was reported in terms of discussed cases at the multidisciplinary tumor board (p = 0.43), mean time between diagnosis and neoadjuvant treatment (p = 0.91), indication to surgery and surgical resection (p = 0.35). Laparoscopic and robot-assisted procedures dropped by 45.4% and 61.9%, respectively, during the lockdown weeks of 2020. No difference was documented for post-operative intensive care unit accesses (p = 0.23) and post-operative mortality (p = 0.06). The surgical volume decrease in 2020 will potentially lead, in the near future, to the diagnosis of a higher rate of advanced stage diseases. However, the reassessment of the Italian Health Service kept guarantying an adequate level of care in tertiary referral centers. Clinicaltrials.gov ID: NCT04380766.

Do We Really Know How Much the Covid-19 Pandemic Affected the Surgical Practice in Northern Italy? A Multi-Center Comparative Study and Cost Analysis.

Background: The Covid-19 pandemic in Northern Italy has slowed down the clinical surgical activity. A system of hub and spoke hospitals was set up to take care of oncological patients with the consequent almost complete abolition of the elective surgical activity for non-oncological pathologies. Methods: We retrospectively analyzed the surgical volumes of 4 different non academic general hospitals in Lombardy belonging to 4 different provinces. The quarter March April May 2019 was compared with the same period of 2020. All different procedures were listed. The cost analysis was performed using the DRG system. Results: In the four hospitals involved the surgical procedures reduced from 1903 to 350 with a drop of the 81.6%. Procedures for cancer from 403 to 161 with a drop of 60.1%. Procedures for benign disease from 1310 to 118 with a drop of the 91%. Emergencies from 190 to 71 with a drop of the 62.6%. State refund for the procedures performed from 6.708.023 to 1.678.154 with a drop of 75%. Conclusions: Elective surgery was dramatically impaired by the Covid-19 pandemic. Above all procedures for non oncological and non urgent patients were particularly affected. In view of a possible second wave of the pandemic, the surgical planning must select patients not only on onco logical criteria but rather on clinical ones. An ad hoc hub and spoke hospitals pathway has to be implemented for benign surgical diseases by whoever is facing the Covid pandemic at its spike.

A novel in vivo assessment of fluid dynamics on aortic valve leaflet using epi-aortic echocardiogram.

BACKGROUND: Mechanical stress caused by blood flow, such as wall shear stress (WSS) and its related parameters, is key moderator of endothelial degeneration. However, an in vivo method to measure WSS on heart valves has not been developed. METHODS: We developed a novel approach, based on vector flow mapping using intraoperative epi-aortic echocardiogram, to measure WSS and oscillatory shear index (OSI) on the aortic valve. We prospectively enrolled 15 patients with normal valves, who underwent coronary artery bypass graft. RESULTS: Systolic WSS on the ventricularis (2.40 ± 0.44 Pa [1.45-3.00 Pa]) was higher than systolic WSS on the fibrosa (0.33 ± 0.08 Pa [0.14-0.47 Pa], P < .001) and diastolic WSS on the ventricularis (0.18 ± 0.07 Pa [0.04-0.28 Pa], P < .001). Oscillatory shear index on the fibrosa was higher than on the ventricularis (0.29 ± 0.04 [0.24-0.36] vs 0.05 ± 0.03 [0.01-0.12], P < .001). A pilot study involving two patients with severe aortic regurgitation showed significantly different values in fluid dynamics. CONCLUSION: Vector flow mapping method using intraoperative epi-aortic echocardiogram is an effective way of measuring WSS and OSI on normal aortic leaflet in vivo, allowing for better understanding of the pathophysiology of aortic valve diseases.

Implementing a protocol to optimize blood use in a cardiac surgery service: results of a pre-post analysis and the impact of high-volume blood users.

BACKGROUND: Blood transfusions are a common and costly intervention for cardiac surgery patients. Evidence suggests that a more restrictive transfusion strategy may reduce costs and transfusion-related complications without increasing perioperative morbidity and mortality. STUDY DESIGN AND METHODS: A transfusion-limiting protocol was developed and implemented in a cardiovascular surgery unit. Over a 5-year period, data were collected on patient characteristics, procedures, utilization of blood products, morbidity, and mortality, and these were compared before and after the protocol was implemented. RESULTS: After the protocol was put in place, fewer patients required transfusions (38.2% vs. 45.5%, p = 0.004), with the greatest reduction observed in postoperative blood use (29.1% vs. 37.2%, p = 0.001). In-hospital morbidity and mortality did not increase. When patients who received transfusions were stratified by procedure, the protocol was most effective in reducing transfusions for patients undergoing isolated coronary artery bypass grafting (CABG; 4.09 units vs. 2.51 units, p = 0.009) and CABG plus valve surgery (10.32 units vs. 4.77 units, p = 0.014). A small group of patients were disproportionate recipients of transfusions, with approximately 6% of all patients receiving approximately half of the blood products. CONCLUSION: A protocol to limit transfusions decreased the proportion of cardiothoracic surgery patients who received blood products. A very small group of patients received a large number of transfusions, and within that group the observed mortality was significantly higher than in the general patient population. Current protocols cannot possibly account for these patients, and this should be considered when analyzing the performance of protocols designed to reduce unnecessary transfusions.

Propofol sedation reduces diaphragm activity in spontaneously breathing patients: ultrasound assessment.

BACKGROUND: The diaphragm is the most important respiratory muscle in humans, and the close relationship between inspired volume and diaphragmatic movement in normal subjects has led to investigations into diaphragmatic activity using ultrasound, during spontaneous breathing and sedative drug infusion. METHODS: A total of 36 consecutive patients undergoing diagnostic procedures under deep propofol sedation were studied. Ultrasound measurements included the following: diaphragmatic thickening end-inspiration (TEI) and end-expiration (TEE). Diaphragmatic thickening fraction (DTF) was calculated from [(TEI - TEE) / TEE] at various time points (at T0 basal; at T1 during propofol infusion; at T2 awakening). Oxygen was administered at 4 L/min, and oxygen saturation (SpO2), end tidal CO2 (EtCO2) and respiratory rate (RR) were recorded. RESULTS: TEI, and TEE decreased by 26.7% and 17.4%, respectively, during propofol infusion (T0 versus T1) (P<0.001), and rapidly recovered at T2 (22.7% and 15.8%). At procedure end (T0 versus T2), TEI maintained a significant reduction (10%, P<0.001), whereas TEE recovered completely. DTF decreased by 56.7% at T1 (P<0.001) but increased by 76.9% (P=0.001) at T2. Recovery after awakening (T0 versus T2) did not reach the baseline value, with a 23.4% difference (P<0.001). SpO2 remained above 96% and EtCO2 below 43 mmHg with no desaturation episodes observed. CONCLUSIONS: Our study showed that deep propofol sedation affects muscle activity in healthy patients. While diaphragmatic strength decreased during sedation, there was no clinically relevant effect on SpO2. The study also confirmed that ultrasound is suitable for measuring diaphragm activity during a normal clinical procedure.

The effects of using a radial artery in patients already receiving bilateral internal mammary arteries during coronary bypass grafting: 30-day outcomes and 14-year survival in a propensity-matched cohort.

OBJECTIVES: Recent studies have demonstrated the superiority of bilateral internal mammary arteries (BIMAs) as conduit material for coronary artery bypass grafting (CABG) surgery. However, there is limited research on the effects of other graft conduits used in patients who require additional bypasses. The goal of this study was to evaluate the impact of the radial artery (RA) when used in conjunction with the BIMAs. METHODS: From the beginning of 2000 to the end of 2013, 4370 patients underwent CABG for three or more vessels at our institution. There were 568 and 183 patients who received BIMA + saphenous vein graft (SVG) and BIMA + radial ± SVG, respectively. Propensity matching was used to create a balanced cohort from these patients, which resulted in two groups of 183 patients. Thirty-day outcomes and long-term survival were compared between the two groups. Long-term follow-up was generated using the Social Security Death Index. RESULTS: There were no significant differences in preoperative characteristics. For 30-day outcomes, the BIMA + radial ± SVG group had more postoperative atrial fibrillation (24.6 vs 12.0%; P = 0.001) and a longer median postoperative length of stay (6 vs 5 days; interquartile range = 2; P = 0.016) than BIMA + SVG patients. There was no significant difference in long-term survival between the two groups over the 14-year period. However, before year 10, the BIMA + SVG group had a trend towards higher survival, whereas on follow-up after 10 years, there was a trend that favoured the BIMA + radial ± SVG patients. Cox regression analysis using a time-dependent covariate demonstrated that when the groups were split at 10 years, there was a statistically significant improvement in survival of the BIMA + radial ± SVG group [adjusted hazard ratio 0.254 95% confidence interval (CI) 0.062-0.977; P = 0.048] over BIMA + SVG patients between 10 and 14 years. CONCLUSIONS: Overall, there were no statistically significant differences in survival between the BIMA + SVG and BIMA + radial ± SVG groups over the 14 years. However, further analysis demonstrated that while the BIMA + radial ± SVG group had a trend towards decreased survival before 10 years, use of the RA in conjunction with BIMAs was associated with significantly increased survival in the later years. A larger cohort of patients with longer follow-up is needed to assess the outcomes of CABG using BIMA + radial ± SVG.

Impact of pump status and conduit choice in coronary artery bypass: A 15-year follow-up study in 1412 propensity-matched patients.

OBJECTIVE: Previous studies have demonstrated that bilateral internal mammary artery (BIMA) grafts lead to superior outcomes compared with single internal mammary artery grafts. This study examines whether cardiopulmonary bypass affects conduit-dependent outcomes of coronary artery bypass grafting (CABG) surgery. METHODS: From 1994 to 2013, a total of 6666 patients underwent isolated CABG surgery at our institution. Of these procedures, 3548 (53.2%) were performed off pump. A BIMA-saphenous vein graft (SVG) was used in 1544, and 5122 had left internal mammary artery-SVGs. These 2 conduit groups differed significantly in baseline characteristics. Propensity matching based on 22 preoperative variables and using a nearest-neighbor matching algorithm was used to make balanced cohorts, resulting in 2 groups of 1006. To account for the influence of pump status on conduit selection, a second propensity score was developed for pump use. These cases were matched to create 4 patient cohorts of 353 patients each (a total of 1412), balanced for both conduit use and pump status. Late mortality was determined using the Social Security Death Index. RESULTS: No difference was found in survival between patients receiving BIMA-SVGs on or off pump (78.9% vs 79.1%). BIMA-SVGs outperformed the left internal mammary artery-SVGs regardless of whether the procedure was performed off pump (73.9%) or on pump (69.9%). CONCLUSIONS: This study demonstrates that the use of cardiopulmonary bypass does not significantly affect the long-term outcomes in these patients as long as full revascularization is achieved. In addition, these results are consistent with prior research showing that the use of BIMAs produces better outcomes than use of a single internal mammary artery when performing CABG.

Statistical assessment of normal mitral annular geometry using automated three-dimensional echocardiographic analysis.

BACKGROUND: The basis of mitral annuloplasty ring design has progressed from qualitative surgical intuition to experimental and theoretical analysis of annular geometry with quantitative imaging techniques. In this work, we present an automated three-dimensional (3D) echocardiographic image analysis method that can be used to statistically assess variability in normal mitral annular geometry to support advancement in annuloplasty ring design. METHODS: Three-dimensional patient-specific models of the mitral annulus were automatically generated from 3D echocardiographic images acquired from subjects with normal mitral valve structure and function. Geometric annular measurements including annular circumference, annular height, septolateral diameter, intercommissural width, and the annular height to intercommissural width ratio were automatically calculated. A mean 3D annular contour was computed, and principal component analysis was used to evaluate variability in normal annular shape. RESULTS: The following mean ± standard deviations were obtained from 3D echocardiographic image analysis: annular circumference, 107.0 ± 14.6 mm; annular height, 7.6 ± 2.8 mm; septolateral diameter, 28.5 ± 3.7 mm; intercommissural width, 33.0 ± 5.3 mm; and annular height to intercommissural width ratio, 22.7% ± 6.9%. Principal component analysis indicated that shape variability was primarily related to overall annular size, with more subtle variation in the skewness and height of the anterior annular peak, independent of annular diameter. CONCLUSIONS: Patient-specific 3D echocardiographic-based modeling of the human mitral valve enables statistical analysis of physiologically normal mitral annular geometry. The tool can potentially lead to the development of a new generation of annuloplasty rings that restore the diseased mitral valve annulus back to a truly normal geometry.

Totally laparoscopic versus laparoscopic-assisted right colectomy for colon cancer: is there any advantage in short-term outcomes? A prospective comparative assessment in our center.

BACKGROUND: Several techniques are described in the literature about laparoscopic treatment of the right colon. Among them, laparoscopic-assisted colectomy (LAC) with creation of an extracorporeal ileocolonic anastomosis remains the favourite approach in most centers. So far, total laparoscopic colectomy (TLC) with intracorporeal anastomosis is not widely performed, because it requires adequate skills and competence in the use of mechanical linear staplers and laparoscopic manual sutures. The purpose of this study was to determine prospectively if TLC offers some advantages in short-term outcomes over LAC. METHODS: A prospective comparative study was designed for 80 consecutive patients who were alternatively treated with TLC and LAC for right colon neoplasms. The following data were collected: operative time, intra- and postoperative complication rate, time to bowel movement, hospitalization time, length of minilaparotomy, number of harvested lymph nodes, and specimen length. RESULTS: Operative time in TLC resulted significantly longer than in LAC (230 vs. 203 min), complication rate was similar in both groups, with no case of anastomotic dehiscence, two anastomotic bleedings in TLC vs. three in LAC and one case of postoperative ileus for each group. One case of death occurred in LAC patient developing a postoperative severe cardiopulmonary syndrome. Time to first flatus was in favour of TLC (2.2 vs. 2.6 days), whereas hospitalization was comparable. As regards to the oncological parameters of radicality, the specimen length was superior in TLC group, but the number of lymph nodes excised was equivalent. The length of the minilaparotomy was clearly shorter in TLC group (5.5 vs. 7.2 cm). CONCLUSIONS: No evidence of relevant differences in terms of functional and safety outcomes between the two laparoscopic procedures. TLC determines less abdominal manipulation and shorter incision length, but clear advantages must be still demonstrated. Larger series are necessary to test the superiority of totally laparoscopic procedures for right colectomy.

Ad hoc transradial coronary angioplasty strategy: experience and results in a single centre.

BACKGROUND: The combination of diagnostic and angioplasty as a single procedure is becoming common practice in many institutions, but the feasibility of this strategy performed with the transradial approach in a large group of patients has not been evaluated. This study was performed to explore the feasibility, safety and cost-effectiveness of the transradial approach as a single procedure for diagnostic angiography and angioplasty, including stent implantation. METHODS: From February 1999 and November 2000 the percutaneous transradial approach was attempted in 800 patients with functional radial arch attested using Allen's test. Interventional procedures, PTCA and stent implantation, when indicated and appropriated, have been performed as a single procedure. RESULTS: Out of 800 patients submitted to coronarography, 390 were treated with PTCA and or stent implantation as single procedure. In this group of patients, 425 lesions (1.2 lesions/patient) were treated. A PTCA was performed in 98 (23.5%) lesions and PTCA plus stent implantation were performed in 327 (76.5%) lesions. Procedural success was achieved in 419/425 lesions (98.5%) in the radial group and in 98% in the staged group. The mean time to place the sheath was longer in the transradial group (P<0.01), but the time required to obtain hemostasis was markedly shorter in the transradial patients (P<0.01); no differences in fluoroscopy time, contrast volume and catheters per case was found. Access site bleeding complications were significantly reduced in the radial group (P<0.01) and total hospital length of stay was lesser in the radial group (mean days 1.9) as compared to femoral group (mean days 2.9) with a reduction of total hospital charge. The reduction of costs for 100 patients was Euro 78,000. CONCLUSION: Our results show that a combined strategy of angiography and angioplasty via the radial artery is feasible, safe, more comfortable for the patient, and more cost-effective than a staged procedure. This approach might be ideal for outpatient or ad hoc invasive coronary procedures.