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Objective: To describe the technique to perform diagnostic standing scapulohumeral joint needle arthroscopy with a 1.2-mm-diameter arthroscope in horses., Study Design: Experimental study., Animals: Eight thoracic limbs in phase 1 and six horses in phase 2., Methods: In phase 1, the feasibility of the technique was evaluated by using a craniolateral arthroscopic approach. An evaluation of the visible structures of the scapulohumeral joint was performed with both a needle arthroscope and a 4-mm-diameter arthroscope. In phase 2, the technique was performed in six healthy sedated horses to validate the technique in live animals and to report any complications or limitations., Results: In phase 1, joint evaluation was similar between arthroscopes and allowed complete evaluation of approximately the lateral half of the humeral head and the lateral glenoid rim. In phase 2, all joints were successfully accessed, and fluid extravasation was mild. Arthroscopic visualization was complete for the centrolateral aspect of the joint in all horses and either complete (3/6) or partial (3/6) for the craniolateral and caudolateral structures, respectively. The procedure was rapidly performed and well tolerated, and no postoperative complications occurred., Conclusion: The described technique was simple and allowed direct inspection of the scapulohumeral joint. Nonetheless, the standing nature of the technique prevents evaluation of the medial aspect of the humeral head and most of the glenoid cavity., Clinical Significance: Needle arthroscopy of the scapulohumeral joint is feasible in horses and offers a diagnostic technique that may improve the surgeon's diagnostic ability for certain shoulder pathologies., (© 2020 American College of Veterinary Surgeons.)

Objective: To describe the technique, experience, and limitations of using a 2-mm flexible endoscope to perform standing minimally invasive sinoscopy., Study Design: In phases 1 and 2, we used cadaveric heads (ex vivo). In phase 3, we used unaffected horses (in vivo)., Animals: Five cadaveric equine skulls in phase 1 and 10 cadaveric equine skulls in phase 2. Six horses older than 5 years in phase 3., Methods: In phase 1, the specimens were used to determine the suitability of the endoscope for sinoscopy and the ideal landmarks to approach the paranasal sinuses through minisinusotomies performed with a 14 gauge needle. In phase 2, a nonblinded evaluation of the visualization of the different sinus compartments was performed, and a score was attributed to each structure. Procedures were video recorded and compared with direct visualization of the sinuses after performing frontal and maxillary flaps. In phase 3, the technique was validated in healthy horses under sedation., Results: The landmarks determined in phase 1 allowed a thorough exploration of the sinuses in phases 2 and 3. Sinoscopy findings were confirmed after direct visualization of the sinuses via frontal and maxillary bone flaps in phase 2. The procedure was well tolerated by all horses., Conclusion: Minimally invasive sinoscopy was readily performed without relevant complications in standing horses. A thorough evaluation of most sinus structures was obtained only using the frontal and the rostral maxillary portals., Clinical Significance: Minimally invasive sinoscopy offers an alternative diagnostic tool to veterinarians. A specialized endoscope and appropriate training are required to perform this minimally invasive procedure., (© 2019 The American College of Veterinary Surgeons.)

Peripheral airway smooth muscle (ASM) mass is increased in severe equine asthma, but no information is available on age related changes in ASM. In this study, peripheral ASM dimensions were determined in healthy horses of different ages. The thickness of the peripheral ASM layer was constant in horses of different ages, but ASM occupied a greater proportion of the inner wall area in young horses compared to older horses. This finding suggests that equine airways experience a decrease in the relative abundance of ASM with age., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: In an era of organ scarcity, the use of left liver grafts for adult recipients could increase the access to liver transplantation (LT). The aim of this study was to evaluate the results in a single-center series of adult left LT over a 14-yr period., Patients and Methods: Between March 1996 and March 2010, 30 adult patients underwent LT with a left liver obtained from 16 split cadaveric livers and 14 living donors (LD). Portal vein inflow modulation was performed in selected cases., Results: A total of 19 (63.3%) grafts had early dysfunction leading to graft failure in six cases (20%). One third of the grafts developed small-for-size syndrome (SFSS). One-yr patient and graft survival was 80% and 76.7%, respectively. Regarding two successive periods, one-yr patient and graft survival dramatically increased from 62.5% to 100% (p = 0.01) and 56.2% to 100% (p = 0.002), respectively. Multivariate analysis disclosed that completion of a portosystemic shunt and the occurrence of post-operative ascites were significantly associated with graft failure., Conclusions: Our results support that improved surgical techniques and careful patient selection can lead to a safe use of left livers for transplantation in adult recipients. Inflow modulation could be performed in very selected cases., (© 2013 John Wiley & Sons A/S.)

Background: A surgical technique using a mesocaval shunt and downstream ligation of the superior mesenteric vein has been recently proposed to overcome the size limitations that restrict the use of partial liver grafts. We designed an experimental study in pigs to evaluate the capacities of liver regeneration and hemodynamic changes after completion of this procedure., Material and Methods: Liver regeneration after left hepatectomy was compared between two groups of five pigs, with or without mesocaval shunt, sacrificed 11 to 14 days after surgery. A third group of five animals was used for hemodynamic studies., Results: Liver regeneration in study animals was 45.3% of controls. This was obtained despite a reduction of the venous inflow to 15.6% of the control, resulting in a net decrease of the total blood inflow to 56% of the control, despite a compensatory increase in the arterial inflow. There was no significant difference in mitotic index, hepatocellular size, and glycogen content between study and control animals., Conclusion: Our experimental study confirms that the regenerative capacities of the pig liver are largely preserved despite the dramatic reduction of the venous blood inflow, reduced to its gastroduodenosplenopancreatic component. This lends further support to the hypothesis that the gastroduodenosplenopancreatic blood is enriched in hepatotrophic factors, likely to originate from the pancreas and duodenum.

Performing an ex vivo liver perfusion as a transient liver support requires perfusing the liver with a flow of 1 ml/min per kg of liver, which could reach 25% of the cardiac output when a human liver is used. This high flow could be detrimental in patients with acute liver failure. Therefore, in an ischemic-induced liver failure pig model, we developed a circuit allowing low flows going out of and into the systemic circulation, whereas the flow going through the ex vivo liver is maintained at a high value. This was obtained by uncoupling the ex vivo circuit from the systemic circulation. Ex vivo liver perfusion was performed in a closed circuit with a flow averaging 1 ml/min per kg of ex vivo liver (700 to 800 ml/min, according to the weight of the livers we used). It was linked to the systemic circulation with input and output flows equal to that used during hemodialysis (200 ml/min). Compared with previously reported direct circuits, this perfusion system was well tolerated from a circulatory point of view. After the induction of ischemic liver failure, the ex vivo liver perfusion led to an increase in urea, branched amino acids to aromatic amino acid ratio, and fractional clearance of indocyanine green and galactose and to a decrease in ammonia and lactic acid. This system allowed the ex vivo liver to keep its clearing properties despite a low extracorporeal flow. It represents an extracorporeal circuit that could be used in place of the direct extracorporeal high-flow liver perfusion.

The shortage of livers for transplant has renewed interest in the potential of temporary liver support such as extra corporeal whole liver perfusion. In an ischemic induced liver failure model we perfused an extra corporeal liver through only a portal vein and assessed the function of this ex vivo liver by using hepatic tests to estimate elimination as well as synthesis capacities. Acute liver failure was performed in five control pigs by a hepatic devascularization associated to an end to side portocaval shunt. In a treated group, 5 to 6 h after this hepatic devascularization, animals were connected to an extra corporeal liver perfused via the portal vein with blood withdrawn from the ischemic liver animal from its portal vein. Devascularization of the liver induced an increase in liver enzymes and ammonia, a drop in the ratio of branched chain amino acids to aromatic amino acids, and a decrease in blood urea and indocyanine green and galactose clearances. In treated animals, urea, amino acid ratio, and clearances increased after the ex vivo liver perfusion. In this group, mean bile production and mean liver oxygen consumption were 13.7 +/- 3.6 ml/h and 16.1 +/- 7.7 ml/min, respectively. In an acute ischemic liver failure pig model, an extra corporeal whole liver perfusion demonstrated detoxification properties as well as synthesis capacities.

This study reviews the evaluation and results of a new liver transplantation technique for small-for-size grafts with portomesenteric disconnection. Twenty Large-White pigs underwent heterotopic liver transplantation after a mesocaval shunt, ligation of the superior mesenteric vein downstream from the shunt, and ligation of the recipient portal vein near the native liver. The donor-to-recipient weight ratio was 24%, and the graft-to-recipient weight ratio was 0.6%. In five control pigs, no mesocaval shunt was performed. The mesocaval shunt provided diversion of 60% of the splanchnic blood flow. The median survival of study pigs was 39 days (range, 8 to 98). Median serum bilirubin levels at 1 week were 12 micromol/L (range, 4 to 59). At autopsy, graft weight was increased to 2.7 times the initial weight and histologic findings were normal. In the control group, all pigs died quickly of acute splanchnic congestion. Portomesenteric disconnection was effective to achieve survival of small-for-size grafts in pig liver transplantation.

Background and Objective: Evaluation of a new pig liver transplantation technique for survival and hypertrophy of a small-sized graft by providing adapted and controlled venous portal flow., Material and Methods: [corrected] Twenty Large-White pigs underwent heterotopic liver transplantation after a mesocaval shunt and ligation of the superior mesenteric vein downstream from the shunt. The donor-to-recipient weight ratio was below 30%. Furthermore, recipient's biliary duct and portal vein into the hilum were tied. In a control group, no mesocaval shunt was performed and the graft received the entire splanchnic venous flow., Results: The mesocaval shunt provided diversion of 60% of the splanchnic blood flow. The median survival of study pigs was 39 days (range: 8-98). Median serum bilirubin levels at 1 week were 12 micromol/L (range: 4-59). At autopsy, graft weight was increased to 2.7 times the initial weight and histological findings were normal. In the control group, all pigs died quickly from acute splanchnic congestion., Conclusion: In a model of heterotopic liver transplantation using small-sized grafts, complete diversion of mesenteric blood flow through a mesocaval shunt resulted in hemodynamic tolerance and hypertrophy of a graft corresponding to less than 30% of the ideal mass.

Recurrent hepatitis C virus (HCV) in liver transplant patients is a major cause of graft loss, liver failure, and need for retransplantation. The results available to date with the use of interferon alfa (IFN-alpha) in the treatment of recurrent HCV in liver transplant patients have been disappointing. The aim of this study was to evaluate the efficacy and clinical utility of post-transplant combination therapy with IFNalpha2b (3 million units 3 times weekly) and oral ribavirin (1,200 mg/d) for a duration of 6 months, followed by maintenance with ribavirin alone for an additional 6 months. Twenty-one liver transplant recipients with recurrent hepatitis C infection (HCV-RNA-positive; active hepatitis without rejection on biopsy) were enrolled in this study. Pretreatment serum alanine transaminase (ALT) levels were at least two times the upper limit of normal. Before treatment, all patients were HCV-RNA-positive and mean HCV-RNA titers were 125 million genome-equivalents/mL. Mean pretreatment histological score was 6.3 +/- 2. After 6 months of combination therapy, all 21 patients had normal ALTs. Ten patients (48%) cleared HCV-RNA from their serum, as assessed by polymerase chain reaction (PCR), and HCV-RNA levels decreased significantly in the others (P = .0001). Improvement in histological score was seen in all patients after combination therapy (P = .0013). During maintenance ribavirin monotherapy, ALT remained normal in all but 1 of the 18 patients who tolerated therapy. HCV-RNA reappeared in 5 patients, but HCV-RNA levels did not return to pretreatment levels (P = .0004). Comparison of pretreatment and postribavirin monotherapy liver biopsies revealed improvement in all but 1 of the 18 patients who tolerated ribavirin (P = .0002). Side effects were restricted to anemia, which necessitated cessation of ribavirin therapy in 3 patients. No patient experienced graft rejection during the study period. These results are significantly better than those reported with IFN-alpha monotherapy. Most importantly, there was a complete absence of graft rejection. These results suggest that the combination of IFN-alpha and ribavirin is effective in reducing HCV-RNA levels and ameliorating hepatocellular injury in recurrent HCV after liver transplantation, and that maintenance therapy with ribavirin monotherapy can maintain the biochemical and histological response.

Isolated liver perfusion was developed for the study of liver physiology and preservation. The recent development of new perfusion devices and appropriate liver preservation solutions prompted us to reconsider liver perfusion for the specific purpose of evaluating viability in terms of biochemical changes, paying special attention to modifications in the histological ultrastructure. Twenty-two isolated pig livers were perfused with autologous blood. Arterio-portal perfusions were carried out using an extracorporeal perfusion circuit with a hollow fibre membrane oxygenator. Four groups of pig livers were studied using three different liver flushing solutions [Ringer's lactate, ELOHES, and University of Wisconsin (UW)] and two different oxygenation modalities. Liver function tests and histological studies were done. Our results revealed that a high partial oxygen pressure (PO2) level was deleterious to the ultrastructural elements of hepatocytes, in particular to the mitochondria. It was also associated with deficient metabolic performance, i.e., poor bile production and lack of aerobic metabolism. Normal blood gas values could be obtained with the use of air for liver oxygenation. Flushing of the liver with Ringer's lactate or a macromolecular solution such as ELOHES was associated with severe liver cell injuries, as reflected by a marked rise in liver enzymes and histological lesions. Satisfactory results were obtained when UW solution was used for liver harvesting. We conclude that an appropriate liver preservation solution, normal blood gas values, and normal physiological arterio-portal pressure and blood flow are essential for appropriate liver function with preservation of liver architecture and of hepatocyte ultrastructures. Total bilirubin in bile and Factor V are sensitive indicators of good liver function.

Background: Hepatic vein outflow is discussed in liver transplantation after preservation of recipient retrohepatic vena cava. The aim of this study was to compare two methods of suparahepatic caval anastomosis., Methods: From January 1993 to January 1995, 81 patients received 88 liver transplants because of liver cirrhosis (n = 70), acute liver failure (n = 7), elective retransplantation after hepatic artery thrombosis (n = 2), giant hemangioma (n = 1), and combined liver-small bowel transplantation (n = 1). Seven patients underwent urgent retransplantation, 12 had preoperative transjugular intrahepatic portocaval stent, and 11 had portal vein thrombosis. Five patients required extracorporeal venous shunt. A total of 82 liver transplantations had preservation of RHVC, and 70 patients received temporary end-to-side portacaval shunt. Suprahepatic caval anastomosis was carried out in 52 patients (group 1) between the graft suprahepatic vena cava and the ostia of recipient left and median hepatic veins. Thirty patients (group 2) had associated 3 cm vertical cavotomy with partial clamping of RHVC. In the fourth postoperative month 20 patients from each group had pressure and gradient measurement made among the hepatic veins, right atria, and the RHVC., Results: Mean pressure gradient between hepatic veins and right atria was 0.75 +/- 0.49 mm Hg in group 1 and 2.06 +/- 0.85 mm Hg in group 2. Between the RHVC and the right atria it was 0.63 +/- 0.5 mm Hg in group 1 and 2.22 +/- 1.29 mm Hg in group 2. A pressure gradient higher than 3 mm Hg was considered hemodynamically significant. This pressure gradient was found between the hepatic veins and right atria in 10% of patients in group 1 and 40% of patients in group 2 (p = 0.03) and between the RHVC and right atria in 15% of patients in group 1 and 30% of patients in group 2 (p = 0.3)., Conclusions: Preservation of the recipient RHVC with recipient caval anastomosis at the ostia of the median and left hepatic veins is a reliable technique without any hepatic venous outflow alteration. Associated cavotomy is not necessary.