A Novel Finite Strain Visco-Hyperelasticity Based Constitutive Model For Elastomers

A novel three-dimensional finite strain viscohyperelastic constitutive model is proposed to capture the strain rate dependency of rubber-like materials. The overall material behavior is defined by cumulative description of hyperelasticity and nonlinear viscoelasticity. The hyperelastic part is based on exponential logarithmic Hart-Smith strain energy function and the viscous part comprises of a fading integral which links the current stresses to the applied strain history. The derived analytical framework is verified with respect to experimental data. The potential of the proposed model has been constituted by an excellent fit between proposed model and considered test data

Complications as indicators of quality assurance after 401 consecutive colorectal cancer resections: the importance of surgeon volume in developing colorectal cancer units in India

<p>Abstract</p> <p>Background</p> <p>The low incidence of colorectal cancer in India, coupled with absence of specialized units, contribute to lack of relevant data arising from the subcontinent. We evaluated the data of the senior author to better define the requirements that would enable development of specialized units in a country where colorectal cancer burden is increasing.</p> <p>Methods</p> <p>We retrospectively analyzed data of 401 consecutive colorectal resections from a prospective database of the senior author. In addition to patient demographics and types of resections, perioperative data like intraoperative blood loss, duration of surgery, complications, re-operation rates and hospital stay were recorded and analyzed.</p> <p>Results</p> <p>The median age was 52 years (10-86 years). 279 were males and 122 were females. The average duration of surgery was 220.32 minutes (range 50 - 480 min). The overall complication rate was 12.2% (49/401) with a 1.2% (5/401) mortality rate. The patients having complications had an increase in their median hospital stay (from 10.5 days to 23.4 days) and the re-operation rate in them was 51%. The major complications were anastomotic leaks (2.5%) and stoma related complications (2.7%).</p> <p>Conclusions</p> <p>This largest ever series from India compares favorably with global standards. In a nation where colorectal cancer is on the rise, it is imperative that high volume centers develop specialized units to train future specialist colorectal surgeons. This would ensure improved quality assurance and delivery of health care even to outreach, low volume centers.</p

To assess the role of multisite instillation of bupivacaine-xylocaine combination for reducing post-operative pain after elective laparoscopic cholecystectomy

Background: Pain following laparoscopic surgery is multifactorial, arising from trocar sites (somatic pain), operative site (visceral pain) and shoulder pain (referred from diaphragmatic irritation because of pneumo-peritoneum). Currently no standard of care exists to reduce post-operative pain by use of local analgesia in laparoscopic cholecystectomy. Despite many studies, there are contradictory results. Aim of the study was to assess whether instillation of local anaesthetics at trocar sites and intraperitoneally, reduces the amount of pain experienced in the immediate postoperative period after laparoscopic cholecystectomy.Methods: This prospective study was carried out in the Department of General Surgery in a tertiary medical Centre in Mumbai. 75 subjects were randomized into 2 groups. Group A consisting of 38 patients were subjected to multisite instillation of LA combination (bupivacaine+xylocaine) at trocar site, gall bladder fossa, sub diaphragmatic space. Group B, (control group) consisting of 37 patients was given no such LA. Post operatively, pain was assessed by VAS scale (0-100) at 1,4,24 hours. Both the groups were compared and analysed.Results: Group A showed significantly reduced pain scores at 1, 4 and 24 hours post operatively as compared to group B.Conclusions: Our results indicate that multisite infiltration of local anesthetic combination (bupivacaine+xylocaine) after laparoscopic cholecystectomy surgery significantly reduces pain at 1, 4 and 24 hours postoperatively

Cost-Effectiveness of Constructing Minimal Shelter to Store INDOT Equipment (Weather Protection)

Currently vehicles used by INDOT are more likely to be subject to maintenance and repair than to replacement. The extent of wear and tear on the vehicles is likely to be impacted by the lack of covered storage in all districts. There are many different levels of covered storage—from tent-like structures to completely covered garages to temperature-controlled environments—each of which has different associated costs. But the associated reduction in equipment wear, speed of startup of equipment, and perhaps better mileage may all reflect savings to INDOT. This project evaluates INDOT’s expected return on investment to create covered areas for equipment (vehicles, other assets), while also assessing the cost difference between vehicles left in covered versus uncovered areas. This project can be used to benchmark certain lot sizes of equipment in order to decide whether or not implementing an indoor storage facility is efficient given the harsh conditions that the equipment may be facing during certain periods of the year. The information can be used to see the impact of weathering on snowplow trucks, the maintenance costs that can be reduced, and the payback period of building a shelter facility

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

Systematic review of sarcopenia in chronic pancreatitis: prevalence, impact on surgical outcomes, and survival

Chronic pancreatitis (CP) is characterized by progressive inflammatory changes to the pancreas, leading to loss of endocrine and exocrine function. Emerging literature suggests sarcopenia may adversely affect outcomes for chronic pancreatitis patients. This systematic review examines the evidence surrounding the impact of sarcopenia on patients with CP. A systematic literature search of MEDLINE (via PUBMED), Cochrane and EMBASE databases was undertaken to identify articles describing body composition assessment in patients with CP. Data collected included definitions of sarcopenia, sarcopenia assessment methodology, baseline demographics, surgical outcomes, and short- and long-term outcomes. In total, nine studies reported on 977 patients with a sarcopenia prevalence of 32.3% (95% CI 22.9-42.6%). CT remains the primary modality to assess for sarcopenia, due to ease of access. None of the studies reporting on post-operative outcomes for patients with chronic pancreatitis found a significant increase in complications among those with sarcopenia. Mortality within 1 year in the outpatient setting from one study of patients with CP was 16% in sarcopenic patients versus 3% (HR: 6.69 (95% CI: 1.79-24.9), p < 0.001) in those with no sarcopenia. Sarcopenia is prevalent in patients with CP occurring in approximately a third of patients. Sarcopenia is associated with an adverse impact on long-term survival

Review of abdominal solid organ transplantation in Jehovah’s Witness patients

Managing blood loss in Jehovah’s Witness (JW) patients is a matter of controversy. These patients will not accept transfusions of red blood cells, white blood cells, platelets or plasma, even if that is required to save their lives. There are many discussions regarding safety of operating upon JW patients in general surgical procedures, but in solid organ transplantation there is a paucity of literature on this subject. We have reviewed individual case reports and small series documenting on experience with solid organ transplantation in JW patients and the strategies adopted to facilitate that. It is clear that such patients require the surgical team to dedicate more time to ensure their safe management. This begins with a thorough, detailed consent of exactly which products and interventions they will or will not accept. Planning must begin weeks before surgery if possible. Each case must be assessed individually, but provided they meet fitness requirements, there are no absolute contraindications to abdominal organ transplantation

Giant solitary fibrous tumour of pleura -an uncommon intrathoracic entity- a case report and review of the literature

A 43-year-old woman presented to us with progressive breathlessness, dry cough and weight loss. A chest radiograph showed homogeneous opacification of the entire left hemithorax. A contrast enhanced computed tomography (CECT) scan of the thorax showed a large intrathoracic mass occupying almost the entire left hemithorax and appeared grossly inoperable. A transcutaneous CT guided tru-cut biopsy revealed a solitary fibrous tumour. We reviewed the CT scans based on the biopsy report, and, in retrospect, the mediastinal vessels seemed more stretched and pushed by the tumor rather than directly infiltrated by it. We performed an exploratory thoracotomy and to our surprise, were able to dissect the mass quite easily off the mediastinum. She had an uneventful postoperative recovery, and the final histopathology confirmed a solitary fibrous tumor. We report this case to emphasize that a cursory clinico-radiological interpretation can dissuade surgical intervention in these patients

Robotic fenestration of massive liver cysts using EndoWrist technology

Background We present the short‐term outcomes of robotic fenestration of symptomatic liver cysts using the EndoWrist One Vessel Sealer. Methods Data from patients who underwent robotic deroofing were collected and analysed retrospectively. Results A total of 17 patients were treated. Mean cyst size was 14 cm (median 15 cm, range 6.3‐24). Seven cysts were in posterosuperior or central segments. There were no mortalities or conversions. Blood loss was minimal in all but one case of 200 ml. Mean operating time was 174 minutes (median 170 min, range 97‐335). Mean hospital stay was 2.5 days (median 2 days, range 1‐10). One patient developed a bile leak requiring ERCP. There are no recurrences with a median follow‐up of 19 months. Conclusion Robotic fenestration can be safely performed and offers distinct advantages over the laparoscopic approach in the treatment of posterosuperior and perihilar cysts at the expense of longer operating times and increased cost