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Background The human immune response to bacterial and viral pathogens has been the focus of intense research, but details on the earliest phases of infection remain unclear. Better knowledge regarding the response of immune cells in the liver is important for the treatment of severe bacterial disease. Ex vivo perfusion which mimics physiological conditions of the liver may provide useful models for this research. An ex vivo model which perfuses hepatic segments would allow translational research on a physiological and reliable model in the scarce resource of human organs. Here we describe the extra-corporeal perfusion of a porcine hepatic segment. Methods Whole porcine livers were retrieved from animals slaughtered according to UK laws for food production and connected to a normothermic extracorporeal perfusion circuit. Constant perfusion via the hepatic artery and portal vein with heparinized autologous blood was established. Sodium bicarbonate, epoprostanol sodium and calcium chloride were also added to the perfusate to regulate acid-base status and reduce vasospasm. Functionality was assessed by monitoring blood-gases, perfusion pressures and flow rate. A segmental ex-vivo liver resection was performed to leave hepatic segment IV in circuit and isolated segment IV perfusion was maintained for one hour. Results Portal venous pressure was maintained between 8-16mmHg and hepatic arterial pressure between 80-90mmHg. Metabolic acidosis resolved with addition of sodium bicarbonate to the circuit with a pH of 7.42 after segmental perfusion for 1 hour. The lactate increased over the course of the perfusion to 20mmol/L after 1 hour of perfusion, however glucose levels were found to improve with the addition of sodium bicarbonate to the circuit. Conclusions Isolated segmental perfusion via ex-vivo resection of porcine hepatic segments is technically challenging. Ischaemic-reperfusion injury coupled with progressive metabolic acidosis may limit model viability. However, addition of sodium bicarbonate to the perfusate aids reduction of glucose levels and improves acidosis. Successful perfusion of a porcine hepatic segment provides the potential for segmental perfusion of human hepatic segments such as those resected during hemi-hepatectomies (HRA approved; REC 21/PR/0287). This is an important milestone leading to the creation of a model to study the early changes in human liver tissue for example during infection.

Background Surgical staplers represent one of the important instruments in modern surgery. Laparoscopic Roux-en-Y gastric bypass is one of the most commonly performed bariatric procedures. Various techniques have been described for performing gastrojejunal (GJ) anastomosis, including linear stapled anastomosis (LSA), circular stapled anastomosis (CSA) and hand-sewn anastomosis (HSA). Objectives An ex-vivo porcine-based experiment was designed to compare the mechanical integrity of the GJ anastomosis among the 3 different techniques by measuring burst pressure (BP). Setting Laboratory-based study conducted at the clinical skills laboratory at Birmingham Heartlands Hospitals, Birmingham, United Kingdom. Methods Porcine stomachs and small bowels were used to create a GJ model. Four GJ anastomosis models each were created using circular stapler (CSA group) and hand-sewn techniques (HSA group). Stomach and small bowel thickness were recorded. BP was measured by sequential injections of methylene-blue diluted saline until a leak was detected. Total volume until leak is recorded. Compliance (C) was calculated using the formula C = ΔP/ΔV. Results Results from our previous experiment for the LSA group are included. One model was excluded from the CSA and the HSA groups due to technical errors. Results were presented as mean ± standard deviation. Total volume in LSA, CSA, and HSA groups was 60 ± 4.08 mL, 73.67 ± 3.22 mL, and 51.67 ± 20.21 mL, respectively. BP in LSA, CSA, and HSA groups was 18 ± 4.69 mm Hg, 20.33 ± 5.77 mm Hg, and 9.67 ± 3.79 mm Hg, respectively. There was a statistically significant difference in BP among the 3 groups (P = .033; Kruskal-Wallis test). C in LSA, CSA, and HSA were 3.50 ± .88 mm Hg/mL, 3.78 ± .85 mm Hg/mL, and 5.39 ± 1.34 mm Hg/mL, respectively (P = .064). Conclusion BP was higher in CSA and LSA groups compared with the HSA group, suggesting a mechanically stronger anastomosis. Despite the lack of statistical significance, higher BP recorded in the CSA group than in the LSA group suggests better anastomotic integrity.

Failure of weight loss is the most common indication for revisional surgery following sleeve gastrectomy (SG) as reported by Guan et al. (Obes Surg. 2019; 29:1965–1975). Recent evidence suggests that the revision rates for SG can be up to 10% when patients are followed up for more than 3 years and as high as 22% after 10 years as reported by Guan et al. (Obes Surg. 2019; 29:1965–1975). Options for revisional surgery following a SG include Roux-en-Y gastric bypass (RYGB), one anastomosis gastric bypass (OAGB), and re-sleeve as the commonest procedures. There is good evidence supporting revisional surgery following failure of weight loss post-primary surgery as reported by Guan et al. (Obes Surg. 2019; 29:1965–1975); Cheung et al. (Obes Surg. 2014; 24:1757–1763); Shimizu et al. (Obes Surg. 2013; 23:1766–1773); and Mora Oliver et al. (Cirugia Espanola. 2019; 97:568–574). However, at the same time, retrospective studies suggest higher complication rates following revisional surgery with a major complication rate up to 10% as reported by Yilmaz et al. (Obes Surg. 2017; 27:2855–2860); Fulton et al. (Can J Surg J Can Chir. 2017; 60:205–211); and Abdelgawad et al. (Obes Surg. 2016; 26:2144–2149). Additionally, the durability of weight loss and morbidity reduction in re-operated patients is still debated and overall high-quality evidence in the field is lacking as discussed by Abdelgawad et al. (Obes Surg. 2016; 26:2144–2149). Aim of this educational video is to demonstrate a revisional bariatric procedure which was technically difficult due to extensive intra-abdominal adhesions and explain the available surgical options and the decision-making process adopted by the surgeons. The video describes a laparoscopic conversion of a SG to OAGB in a 37-year-old female patient due to weight regain. Her primary bariatric procedure was planned to be a RYGB but due to extensive intra-abdominal adhesions discovered at the time of primary surgery, a SG was performed. Pre-primary procedure weight was 134kg with a BMI of 52.3kg/m2. After SG, the patient lost a maximum of 50kg (71.4% excess BMI loss) within the first 18 months before she started regaining weight. Her BMI was 45.4kg/m2 when she was referred for revisional surgery. During the procedure, dense small bowel adhesions were encountered and required meticulous dissection in order to free adequate small bowel to allow a safe, effective, and tension-free anastomosis. One hundred fifty centimeters of small bowel was the maximum length that could be safely dissected starting from the ligament of Treitz. An OAGB was preferred to RYGB as it is routine practice in our unit to bypass 200cm of small bowel for revisional RYGB procedures (50-cm biliopancreatic limb and 150-cm alimentary limb), whilst all OAGB’s (primary and revisional) have an afferent limb of 150cm. A re-sleeve was also considered as a viable alternative. Extensive adhesiolysis followed by OAGB were performed successfully with an uneventful post-operative course. The patient was discharged on the second post-operative day. Excess BMI loss was 58% at 1-year follow-up. Revisional surgery can be a challenging especially in the context of extensive surgical history. OAGB can be used as an alternative to RYGB.

Background: Numerous techniques have been described for fashioning gastrojejunostomy (GJ) in a Roux-en-Y gastric bypass. These include hand-sewn anastomosis (HSA) and mechanical anastomosis; the latter includes circular stapled anastomosis (CSA) or manual linear stapled anastomosis (mLSA). More recently, this list also includes powered linear stapled anastomosis (pLSA). The aim of this study was to analyse if addition of power to stapling would improve the integrity of GJ anastomosis in ex vivo porcine models. Subjects and Methods: The present study included five groups – mLSA1, mLSA2, HSA, CSA, and pLSA. Sequential infusions of methylene blue-coloured saline were performed into the GJ models. Pressure readings were recorded till the point of leak denoting burst pressure (BP). Total volume (TV) and site of leak were recorded. Compliance was calculated from the equation ΔTV/ΔBP. Results: Differences in pouch and intestinal thickness were not statistically significant between the models. BPs were higher in the mechanical anastomosis groups, i.e., pLSA 21 ± 9.85 mmHg, CSA 20.33 ± 5.78 mmHg, mLSA1 18 ± 4.69 mmHg and mLSA2 11 ± 2.94 mmHg, when compared to HSA 9.67 ± 3.79 mm Hg, which was found to be statistically significant (Kruskal–Wallis test, P = 0.03). Overall, the highest BP was recorded for powered stapling followed by circular, and then, linear stapling; however, this difference was not statistically significant (P = 0.86). There was no statistically significant difference among groups with regard to compliance (Kruskal–Wallis test, P = 0.082). Conclusion: Despite the limited number of samples, mechanical anastomosis showed a statistically higher BP when compared to HSA, suggesting better anastomotic integrity. The pLSA group showed promising results with the highest BP recorded among all groups; however, this did not reach statistical significance.

In the recent past, laparoscopic adjustable gastric bands (LAGBs) have been used extensively in bariatric surgery. Despite questionable long-term efficacy, they are generally safe and reversible. We report a possibly unique presentation of a potential hazard of the insertion technique; a misplaced LAGB encircling the abdominal aorta, which was confirmed radiologically and on operative removal of the gastric band. This is a dramatic complication of LAGB, representing an important anatomical hazard for gastric band insertion.

Mechanical gastro-intestinal anastomosis using stapler is a critical step in laparoscopic Roux-en-Y gastric bypass (RYGB). To date the effect of the direction of staples on anastomotic leak has not been investigated. The study aim was to investigate the impact of the direction of staples on the integrity of the gastro-jejunal anastomosis. Eight gastro-jejunostomy (GJ) models were performed using porcine stomach and small intestine. Specimens were divided into group A where the cartridge was in the gastric lumen with the anvil in the jejunal lumen and vice versa in group B. Enterotomy was closed and gastric and jejunal ends were stapled off. Burst pressure (BP) was measured by infusion of methylene blue saline into the GJ model until leak occurred. Site of leak, BP, and total volume (TV) infused were recorded. Compliance (C) was calculated from the equation ΔTV/ΔBP. The BP was greater in group A compared to group B (18 mmHg (range 15–25) versus 11 mmHg (range 8–15); p = 0.045) despite similar TV between the groups 60.00 mL (range 55.00–65.00) versus 51.25 mL (range 40.00–60.00); p = 0.11). The compliance did not significantly differ between groups A and B (6.38 mL/mmHg (range 4.34–8.59) versus 5.61 mL/mmHg (range 3.93–7.21); p = 0.48). BP recorded when the stapler cartridge was introduced in the gastric lumen was higher than when it was introduced from the jejunal lumen. The lack of difference in compliance between groups suggests that the difference in BP was due to the difference in the direction of staples.

Transfusion support is a critical component of modern combat casualty care. Experiences in the recent wars in Iraq and Afghanistan have seen the refinement of the concept of damage control resuscitation[1][1] with the introduction of multiple, innovative developments such as platelet apheresis in