Normothermic Regional Perfusion in Solid Organ Transplantation

Normothermic regional perfusion (NRP) is used to restore the flow of oxygenated blood following cardiac arrest and reverse warm ischemic injury in donation after circulatory death (DCD) organ transplantation. The use of NRP in this setting has typically been limited to the abdominal cavity, though its use has recently been expanded to chest to help recover DCD hearts, as well. This chapter evaluates the principles behind the use of NRP in DCD organ transplantation as well as not only technical but also ethical and legal aspects associated with its application and the clinical results that have been achieved to date when it has been used to recover various solid organs through the DCD process

Infiltrative xanthogranulomatous cholecystitis mimicking aggressive gallbladder carcinoma: A diagnostic and therapeutic dilemma

Xanthogranulomatous cholecystitis (XGC) is an uncommon variant of chronic cholecystitis. The perioperative findings in aggressive cases may be indistinguishable from those of gallbladder or biliary tract carcinomas. Three patients presented mass lesions that infiltrated the hepatic hilum, provoked biliary dilatation and jaundice, and were indicative of malignancy. Surgical excision was performed following oncological principles and included extirpation of the gallbladder, extrahepatic bile duct, and hilar lymph nodes, as well as partial hepatectomy. Postoperative morbidity was minimal. Surgical pathology demonstrated XGC and absence of malignancy in all three cases. All three patients are alive and well after years of follow-up. XGC may have such an aggressive presentation that carcinoma may only be ruled out on surgical pathology. In such cases, the best option may be radical resection following oncological principles performed by expert surgeons, in order that postoperative complications may be minimized if not avoided altogether

Posttest Analyses of the Steel Containment Vessel Model

A high pressure test of a scale model of a steel containment vessel (SCV) was conducted on December 11-12, 1996 at Sandia National Laboratories, Albuquerque, NM, USA. The test model is a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of an improved Mark II boiling water reactor (BWR) containment. This testis part of a program to investigate the response of representative models of nuclear containment structures to pressure loads beyond the design basis accident. The posttest analyses of this test focused on three areas where the pretest analysis effort did not adequately predict the model behavior during the test. These areas are the onset of global yielding, the strain concentrations around the equipment hatch and the strain concentrations that led to a small tear near a weld relief opening that was not modeled in the pretest analysis

Donation after circulatory death liver transplantation: consensus statements from the Spanish Liver Transplantation Society

Livers from donation after circulatory death (DCD) donors are an increasingly more common source of organs for transplantation. While there are few high-level studies in the field of DCD liver transplantation, clinical practice has undergone progressive changes during the past decade, in particular due to mounting use of postmortem normothermic regional perfusion (NRP). In Spain, uncontrolled DCD has been performed since the late 1980s/early 1990s, while controlled DCD was implemented nationally in 2012. Since 2012, the rise in DCD liver transplant activity in Spain has been considerable, and the great majority of DCD livers transplanted in Spain today are recovered with NRP. A panel of the Spanish Liver Transplantation Society was convened in 2018 to evaluate current evidence and accumulated experience in DCD liver transplantation, in particular addressing issues related to DCD liver evaluation, acceptance criteria, and recovery as well as recipient selection and postoperative management. This panel has created a series of consensus statements for the standard of practice in Spain and has published these statements with the hope they might help guide other groups interested in implementing new forms of DCD liver transplantation and/or introducing NRP into their clinical practices

Instrumentation of a prestressed concrete containment vessel model

A series of static overpressurization tests of scale models of nuclear containment structures is being conducted by Sandia National Laboratories for the Nuclear Power Engineering Corporation of Japan and the U.S. Nuclear Regulatory Commission. At present, two tests are being planned: a test of a model of a steel containment vessel (SCV) that is representative of an improved, boiling water reactor (BWR) Mark II design; and a test of a model of a prestressed concrete containment vessel (PCCV). This paper discusses plans and the results of a preliminary investigation of the instrumentation of the PCCV model. The instrumentation suite for this model will consist of approximately 2000 channels of data to record displacements, strains in the reinforcing steel, prestressing tendons, concrete, steel liner and liner anchors, as well as pressure and temperature. The instrumentation is being designed to monitor the response of the model during prestressing operations, during Structural Integrity and Integrated Leak Rate testing, and during test to failure of the model. Particular emphasis has been placed on instrumentation of the prestressing system in order to understand the behavior of the prestressing strands at design and beyond design pressure levels. Current plans are to place load cells at both ends of one third of the tendons in addition to placing strain measurement devices along the length of selected tendons. Strain measurements will be made using conventional bonded foil resistance gages and a wire resistance gage, known as a {open_quotes}Tensmeg{close_quotes}{reg_sign} gage, specifically designed for use with seven-wire strand. The results of preliminary tests of both types of gages, in the laboratory and in a simulated model configuration, are reported and plans for instrumentation of the model are discussed

Steel Containment Vessel Model Test: Results and Evaluation

A high pressure test of the steel containment vessel (SCV) model was conducted on December 11-12, 1996 at Sandia National Laboratories, Albuquerque, NM, USA. The test model is a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of an improved Mark II boiling water reactor (BWR) containment. A concentric steel contact structure (CS), installed over the SCV model and separated at a nominally uniform distance from it, provided a simplified representation of a reactor shield building in the actual plant. The SCV model and contact structure were instrumented with strain gages and displacement transducers to record the deformation behavior of the SCV model during the high pressure test. This paper summarizes the conduct and the results of the high pressure test and discusses the posttest metallurgical evaluation results on specimens removed from the SCV model

Somatostatin and the 'Small-For-Size' Liver

"Small-for-size" livers arising in the context of liver resection and transplantation are vulnerable to the effects of increased portal flow in the immediate postoperative period. Increased portal flow is an essential stimulus for liver regeneration. If the rise in flow and stimulus for regeneration are excessive; however, liver failure and patient death may result. Somatostatin is an endogenous peptide hormone that may be administered exogenously to not only reduce portal blood flow but also offer direct protection to different cells in the liver. In this review article, we describe key changes that transpire in the liver following a relative size reduction occurring in the context of resection and transplantation and the largely beneficial effects that peri-operative somatostatin therapy may help achieve in this setting

A novel and simple formula to predict liver mass in porcine experimental models.

A primary limitation in hepatic surgery is leaving a remnant liver of adequate size and function. Experimental models have been designed to study processes of liver injury and regeneration in this context, yet a formula to accurately calculate liver mass in an animal model is lacking. This study aims to create a novel and simple formula to estimate the mass of the native liver in a species of pigs commonly used in experimental liver surgery protocols. Using data from 200 male weanling Landrace-Large White hybrid pigs, multiple linear regression analysis is used to generate the formula. Clinical features used as variables for the predictive model are body mass and length. The final formula for pig liver mass is as follows: Liver mass (g) = 26.34232 * Body mass (kg) - 1.270629 * Length (cm) + 163.0076; R2 = 0.7307. This formula for porcine liver mass is simple to use and may be helpful in studies using animals of similar characteristics to evaluate restoration of liver mass following major hepatectomy

Perioperative Complications and Long-Term Follow-Up of Liver Transplantation in Hemorrhagic Hereditary Telangiectasia: Report of Three Cases and Systematic Review

The aim was to describe three patients with hemorrhagic hereditary telangiectasia (HHT) requiring liver transplantation (LT) and to perform a systematic review focusing on surgical complications and long-term follow-up. Unrestricted searches of the Medline and Embase databases were performed through February 2022. Forty-five studies were selected including 80 patients plus the three new reported patients, 68 (81.9%) were female and mean age was 50 (27-72) years. Main indications for LT were high-output cardiac failure (n = 40; 48.2%), ischemic cholangitis (n = 19; 22.9%), and a combination of both conditions (n = 13;15.6%). Mean cold ischemic time and red blood cell units transfused during LT were 554 (300-941) minutes and 11.4 (0-88) units, respectively. Complications within 30 days were described in 28 (33.7%) patients, mainly bleeding complications in 13 patients, hepatic artery (HA) thrombosis in four and hepatic vein thrombosis in one. Mean follow-up was 76.4 (1-288) months, and during it, four new patients developed thrombotic complications in HA, HA aneurysm, celiac artery, and the portal-splenic-mesenteric vein. HHT relapse in the transplant allograft was detected in 13 (17.1%) patients after 1-19 years (including two fatal recurrences). Overall mortality was 12%. In conclusion, previous assessment of HA anatomy and hyperdynamic circulatory state could reduce LT complications. The risk of relapse in the hepatic graft supports a multidisciplinary follow-up for HHT patients with LT

Pheochromocytoma as a rare cause of arterial hypertension in a patient with autosomal dominant polycystic kidney disease: A diagnostic and therapeutic dilemma.

INTRODUCTION: Individuals with autosomal dominant polycystic kidney disease (ADPKD) frequently suffer arterial hypertension even prior to significant loss of renal function, a clinical situation that obscures detection of modifiable secondary causes of hypertension. PRESENTATION OF CASE: A 50-year-old man with ADPKD and polycystic liver and resistant hypertension is diagnosed with a 4-cm right adrenal mass. Cross-sectional MRI is indicative of pheochromocytoma versus adrenocortical carcinoma or metastasis, though there are no typical PCC symptoms and plasma and urine metanephrines are within normal ranges. Since malignancy cannot be excluded, right adrenalectomy is performed. Considering that the enlarged liver poses an obstacle for transperitoneal open and laparoscopic approaches, a retroperitoneoscopic approach is used. Surgical pathology reveals a 4.5-cm pheochromocytoma; the patient no longer requires antihypertensive therapy. DISCUSSION & CONCLUSION: Pheochromocytoma is a rare but treatable cause of hypertension in ADPKD; given the anatomical complexities these patients present, careful preoperative planning and surgical technique are essential to a favorable outcome