Pig kidney transplantation: an up-to-date guideline

Background: Swine and human beings have many aspects in common that make swine a well-characterized large animal model for kidney transplantation (KTx). However, pigs have some peculiar anatomical characteristics that standardized techniques must adapt to. The aim of this study was to prepare an up-to-date guideline for porcine KTx. Methods: To achieve this goal, we performed a Medline search using the terminology ”kidney’ or ”renal’ and ”transplantation’ and ”pig’ or ”swine’ or ”porcine’. We found over 1,300 published articles since 1963. Only 13 studies focused on the surgical aspect. Furthermore, we reviewed related books and articles about swine anatomical characteristics and surgery. Finally, our experimental experiences of KTx during the last few decades were added to this collection. Results: Proper hosting, fasting, anesthesia, medical therapy and monitoring can prevent postoperative complications. Explantation with a Carrel patch of the aorta facilitates the implantation and prevents future stenosis. Native nephrectomy makes the follow-up of the implanted organ more precise. KTx in the infrarenal fossa via end-to-side anastomosis to the aorta and inferior vena cava followed by ureteroureterostomy are the recommended options for KTx in pigs compared to other possible methods. Conclusion: Pigs, with respect to their characterizations, constitute one of the best large animal models for KTx. Preoperative preparations are as important as the intra- and postoperative management. Using the most adaptable methods of surgery with respect to the specific anatomical characteristics of pigs can prevent undermining the studies and avoid preventable complications and pitfalls. Copyright (c) 2012 S. Karger AG, Base

Evaluation of the modified HTK solution in pancreas transplantationdAn experimental model

One of the great challenges in pancreas transplantation is the ischemia reperfusion injury. It is mentioned that free oxygen and/or nitrogen radicals play a prominent role in this phase. To minimize this problem, a modified histidineetryptophan eketoglutarate (HTK) solution that contains modified antioxidants has been developed. Our aim was to evaluate this solution in improving the viability of the pancreas in comparison with standard HTK and University of Wisconsin (UW) solutions in a porcine model of pancreas transplantation

Hand-Assisted laparoscopic donor nephrectomy PERiumbilical versus Pfannenstiel incision and return to normal physical ACTivity (HAPERPACT): study protocol for a randomized controlled trial

Background: Hand-assisted laparoscopic living donor nephrectomy (HALDN) using a periumbilical or Pfannenstiel incision was developed to improve donor outcome after a kidney transplant. The aim of this study was to investigate two methods of hand assistance and kidney removal during HALDN and their effect on the time it takes for the donor to return to normal physical activity. Methods/design: This study was initiated in November 2017 and is expected to last for 2 years. To be eligible for the study, donors must be more than 20 years of age and must not be receiving permanent pain therapy. Only donors with a single artery and vein in the graft are being enrolled in this trial. Donors with infections or scars in the periumbilical or hypogastric area, bleeding disorders, chronic use of immunosuppressive agents, or active infection will be excluded. Donors will be randomly allocated to either a control arm (periumbilical incision) or an intervention arm (Pfannenstiel incision). The sample size was calculated as 26 organ donors in each group. The primary endpoint is the number of days it takes the donor to return to normal physical activity (up to 4 weeks after the operation). Secondary endpoints are intraoperative outcomes, including estimated blood loss, warm ischemia time, and duration of the operation. Postoperative pain will be assessed using the visual analog scale, rescue analgesic use, and peak expiratory flow rate. Length of hospital stay, physical activity score, time to return to work, donor satisfaction, cosmetic score, postoperative complications, and all-cause mortality in living donors will also be reported. Delayed graft function, primary non-function, serum creatinine levels, and glomerular filtration rate will also be assessed in the recipients after transplantation. Discussion: This is the first randomized controlled trial to compare the time it takes the living donor to return to normal physical activity after HALDN using two different types of incision. The comprehensive findings of this study will help decide which nephrectomy procedure is best for living donors with regard to patient comfort and satisfaction as well as graft function in the recipient after transplantation. Trial registration: ClinicalTrials.gov, NCT03317184 . Registered on 23 October 2017

SmartPAN: A novel polysaccharide-microsphere-based surgical indicator of pancreatic leakage

Postoperative pancreatic fistula is a major surgical complication that can follow pancreatic resection. Postoperative pancreatic fistula can develop as a consequence of leaking pancreatic fluid, which calls for an intraoperative indicator of leakage. But suitable indicators of pancreatic leakage have yet to be found. This study details the evidence-based development and early efficacy assessments of a novel pancreatic leakage indicator (SmartPAN), following the IDEAL framework of product development.We developed 41 SmartPAN prototypes by combining indicators of pancreatic fluid with a polysaccharide-microsphere matrix. The prototypes were assessed in vitro using porcine (Sus scrofa domesticus) pancreatic tissue and ex vivo with human pancreatic fluid. From these initial tests, we chose a hydrogel-based compound that uses the pH indicator bromothymol blue to detect alkali pancreatic fluid. This prototype was then assessed in vivo for usability, effectiveness and reliability using a porcine model. Treatment groups were defined by SmartPAN-reaction at initial pancreatic resection: indicator-positive or negative. Indicator-positive individuals randomly received either targeted closure of leakage sites or no further closure. We assessed SmartPAN’s reliability and effectiveness by monitoring abdominal drainage for amylase and with relaparotomy after 48 h. SmartPAN responses were consistent between both surgical procedures and conformed to amylase measurements. In conclusion, we have developed the first surgery-ready indicator for predicting the occurrence of pancreatic leakage during pancreatic resection. SmartPAN can enable targeted prophylactic closure in a simple and reliable way, and thus may reduce the impact of postoperative pancreatic fistula by guiding peri- and post-operative management

Simulating Surgical Skills in Animals: Systematic Review, Costs & Acceptance Analyses

Background:Modern surgery demands high-quality and reproducibility. Due to new working directives, resident duty hours have been restricted and evidence exists that pure on-the-job training provides insufficient exposure. We hypothesize that supplemental simulations in animal models provide a realistic training to augment clinical experiences. This study reviews surgical training models, their costs and survey results illustrating academic acceptance. Methods:Animal models were identified by literature research. Costs were analyzed from multiple German and Austrian training programs. A survey on their acceptance was conducted among faculty and medical students. Results:915 articles were analyzed, thereof 91 studies describedin-vivoanimal training models, predominantly for laparoscopy (30%) and microsurgery (24%). Cost-analysis revealed single-training costs between 307euro and 5,861euro depending on model and discipline. Survey results illustrated that 69% of the participants had no experience, but 66% would attend training under experienced supervision. Perceived public acceptance was rated intermediate by medical staff and students (4.26;1-low, 10 high). Conclusion:Training in animals is well-established and was rated worth attending in a majority of a representative cohort to acquire key surgical skills, in light of reduced clinical exposure. Animal models may therefore supplement the training of tomorrow's surgeons to overcome limited hands-on experience until virtual simulations can provide such educational tools

One life ends, another begins: Management of a brain-dead pregnant mother - A systematic review -

Background: An accident or a catastrophic disease may occasionally lead to brain death (BD) during pregnancy. Management of brain-dead pregnant patients needs to follow special strategies to support the mother in a way that she can deliver a viable and healthy child and, whenever possible, also be an organ donor. This review discusses the management of brain-dead mothers and gives an overview of recommendations concerning the organ supporting therapy. Methods: To obtain information on brain-dead pregnant women, we performed a systematic review of Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). The collected data included the age of the mother, the cause of brain death, maternal medical complications, gestational age at BD, duration of extended life support, gestational age at delivery, indication of delivery, neonatal outcome, organ donation of the mothers and patient and graft outcome. Results: In our search of the literature, we found 30 cases reported between1982 and 2010. A nontraumatic brain injury was the cause of BD in 26 of 30 mothers. The maternal mean age at the time of BD was 26.5 years. The mean gestational age at the time of BD and the mean gestational age at delivery were 22 and 29.5 weeks, respectively. Twelve viable infants were born and survived the neonatal period. Conclusion: The management of a brain-dead pregnant woman requires a multidisciplinary team which should follow available standards, guidelines and recommendations both for a nontraumatic therapy of the fetus and for an organ-preserving treatment of the potential donor

Experiments and Predictions of Heat Transfer Characteristics in Circulating Fluidized Bed Boilders

This thesis presents experiments and predictions of heat transfer characteristics in circulating fluidized bed boilers. The boiler used for the experiments has a maximum load of 12 MWth, and the dimensions of the combustion chamber are 1.4 m x 1.7 m x 1 3. 5 m. The equipment is located at Chalmers University of Technology in Goteborg. A method for measuring the local suspension temperature with a shielded thermocouple in the combustion chamber of a fluidized bed combustor is described. Two major sets of heat transfer experiments were conducted. The first concerned temperature measure me nts close to the wall. In these experiments, temperature distributions were measured at different heights above the distributor plate for different operating conditions. It was found that the thermal boundary layer thickness decreases with increasing su pe rficial gas velocity, but is less affected by the bulk bed temperature. The aim of the second set of experiments was to measure the local time-averaged heat transfer coefficients at the membrane wall of the combustor. It was found that the heat transfer c oefficient increases slightly with decreasing height, superficial gas velocity, suspension density, and with bulk bed temperature. It was also found that heat transfer coefficients at the membrane wall were, lower than those at the refractory wall (flat w all). Finally, on basis of the current understanding gained from experiments, an empirical-analytical model is proposed. The fluid is assumed to be composed of a dispersed phase and clusters of particles. Several parameters are present in the model, and metho ds for estimation of these are discussed. The model was able to predict heat transfer coefficients in decent agreement with corresponding experiments

Experiments and Predictions of Heat Transfer Characteristics in Circulating Fluidized Bed Boilders

This thesis presents experiments and predictions of heat transfer characteristics in circulating fluidized bed boilers. The boiler used for the experiments has a maximum load of 12 MWth, and the dimensions of the combustion chamber are 1.4 m x 1.7 m x 1 3. 5 m. The equipment is located at Chalmers University of Technology in Goteborg. A method for measuring the local suspension temperature with a shielded thermocouple in the combustion chamber of a fluidized bed combustor is described. Two major sets of heat transfer experiments were conducted. The first concerned temperature measure me nts close to the wall. In these experiments, temperature distributions were measured at different heights above the distributor plate for different operating conditions. It was found that the thermal boundary layer thickness decreases with increasing su pe rficial gas velocity, but is less affected by the bulk bed temperature. The aim of the second set of experiments was to measure the local time-averaged heat transfer coefficients at the membrane wall of the combustor. It was found that the heat transfer c oefficient increases slightly with decreasing height, superficial gas velocity, suspension density, and with bulk bed temperature. It was also found that heat transfer coefficients at the membrane wall were, lower than those at the refractory wall (flat w all). Finally, on basis of the current understanding gained from experiments, an empirical-analytical model is proposed. The fluid is assumed to be composed of a dispersed phase and clusters of particles. Several parameters are present in the model, and metho ds for estimation of these are discussed. The model was able to predict heat transfer coefficients in decent agreement with corresponding experiments