Hepatic ischemia-reperfusion syndrome and its effect on the cardiovascular system: The role of treprostinil, a synthetic prostacyclin analog.

Hepatic ischemia-reperfusion syndrome has been the subject of intensive study and experimentation in recent decades since it is responsible for the outcome of several clinical entities, such as major hepatic resections and liver transplantation. In addition to the organ's post reperfusion injury, this syndrome appears to play a central role in the dysfunction of distant tissues and systems. Thus, continuous research should be directed toward finding effective therapeutic options to improve the outcome and reduce the postoperative morbidity and mortality rates. Treprostinil is a synthetic analog of prostaglandin I2, and its experimental administration has shown encouraging results. It has already been approved by the Food and Drug Administration in the United States for pulmonary arterial hypertension and has been used in liver transplantation, where preliminary encouraging results showed its safety and feasibility by using continuous intravenous administration at a dose of 5 ng/kg/min. Treprostinil improves renal and hepatic function, diminishes hepatic oxidative stress and lipid peroxidation, reduces hepatictoll-like receptor 9 and inflammation, inhibits hepatic apoptosis and restores hepatic adenosine triphosphate (ATP) levels and ATP synthases, which is necessary for functional maintenance of mitochondria. Treprostinil exhibits vasodilatory properties and antiplatelet activity and regulates proinflammatory cytokines; therefore, it can potentially minimize ischemia-reperfusion injury. Additionally, it may have beneficial effects on cardiovascular parameters, and much current research interest is concentrated on this compound.

Constriction Band Release in a Neonatal Ischemic Limb: A Pediatric Anesthesiology Case Report.

A 1.1 Kg, four-hour-old, 29-weeks-gestation male patient presented with right upper extremity ischemia secondary to neonatal constriction band syndrome. Emergency constriction band release was deemed necessary to facilitate limb salvage. The anesthetic management of this patient required close communication with the surgical team and meticulous attention to the risks of post-reperfusion syndrome and blood loss in this fragile neonate. Limb salvage was ultimately successful, and the patient demonstrated full neurologic recovery at his two-year follow-up visit.

Struggling Between Liver Transplantation and Portopulmonary Hypertension.

Portopulmonary hypertension (PoPH) is a progressive, ultimately fatal cardiopulmonary disease that occurs exclusively in patients with underlying portal hypertensive liver disease. PoPH outcomes are driven by both the severity of underlying liver disease and the degree of cardiac adaptation to elevated pulmonary pressures. The mainstay of treatment in PoPH is targeted pulmonary vascular therapy. Liver transplantation (LT) can be beneficial in some patients, but is associated with considerable risks in the PoPH population, and outcomes are variable. The optimal management strategy for PoPH, LT, or medical therapy alone, is unclear, and further research is needed to help guide clinical decision-making.

Application value of donor liver autologous portal venous blood rinse in orthotopic liver trans-plantation / 中华消化外科杂志

Objective:To investigate the application value of donor liver autologous portal venous blood rinse in orthotopic liver transplantation (OLT).Methods:The retrospective cohort study was conducted. The clinicopathological data of 35 pairs of donors and recipients who underwent OLT in the First Affiliated Hospital of University of Science and Technology of China from May 2018 to June 2019 were collected. Of the 35 donors, there were 31 males and 4 females, aged (48±9)years. Of the 35 recipients, there were 25 males and 10 females, aged (47±9)years. Of the 35 recipients, 16 recipients undergoing donor liver autologous portal venous blood rinse were allocated into the portal vein group, and 19 recipients undergoing donor liver albumin water rinse were allocated into the albumin group. Observation indicators: (1) surgical situations; (2) postoperative situations; (3) follow-up. Measurement data with normal distribution were represented as Mean± SD, and compari-son between groups was analyzed using the t test. Measurement data of skewed distribution were represented as M(range). Count data were descried as absolute numbers, and comparison between groups was analyzed using the Fisher exact probability. Results:(1) Surgical situations. The anhepatic phase time and arterial blood Ca 2+ concentration within 5 minutes after reperfusion of the recipients were (52±12)minutes and (0.99±0.10)mmol/L in the portal vein group, versus (64±12)minutes and (1.05±0.07)mmol/L in the albumin group, showing significant differences in the above indicators between the two groups ( t=2.94, 2.22, P<0.05). The mean arterial pressure, arterial blood K +concentration and arterial blood pH within 5 minutes after reperfusion of the recipients were (70±24)mmHg (1 mmHg=0.133 kPa), (4.7±1.3)mmol/L and 7.27±0.06 in the portal vein group, versus (71±28)mmHg, (4.6±1.1)mmol/L and 7.30±0.07 in the albumin group, showing no significant difference in the above indicators between the two groups ( t=0.14, 0.30, 1.22, P>0.05). (2) Post-operative situations. Cases with post-reperfusion syndrome (PRS), cases with severe PRS of cardiac arrest, cases with primary graft nonfunction of the recipients were 6, 0, 2 in the portal vein group, versus 8, 1, 1 in the albumin group, showing no significant difference in the above indicators between the two groups ( P>0.05). Total bilirubin on postoperative day 7 of the recipients was (90±52)μmol/L in the portal vein group, versus (166±112)μmol/L in the albumin group, showing a significant difference between the two groups ( t=2.66, P<0.05). International normalized ratio on postoperative day 7, the highest alanine aminotransferase and aspartate aminotransferase within 7 days after operation of the recipients were 2.1±2.0, (1 952±2 813)IU/L and (3 944±6 673)IU/L in the portal vein group, versus 1.8±0.6, (1 023±1 014) IU/L and (2 005±2 910)IU/L in the albumin group, showing no significant difference in the above indicators between the two groups ( t=0.66, 1.23, 1.08, P>0.05). Recipients with hepatic artery complication and biliary complication were 1 and 2 in the portal vein group, versus 0 and 4 in the albumin group, showing no significant difference in the above indicators between the two groups ( P>0.05). There were 3 cases and 2 cases died during the perioperative period in the portal vein group and the albumin group, respectively. (3) Follow-up. Of the 35 recipients, 30 recipients were followed up for 534(range, 28?776)days after operation. During the follow-up, there were 3 patients with postoperative complications in the portal vein group including 2 cases died and 1 case recovered after sympto-matic treatment. There were 5 patients with postoperative complications in the albumin group including 1 case died and 4 cases recovered after symptomatic treatment. Up to the follow-up date, 11 patients in the portal vein group and 16 patients in the albumin group were in good condition. Conclusion:Rinse of the donor liver with autologous portal venous blood during liver transplantation can shorten the time of anhepatic phase, without increasing the occurrence of post-reperfusion syndrome, ischemia re-perfusion injury and biliary tract complications.

Hypothermic Oxygenated Machine Perfusion (HOPE) Prior to Liver Transplantation Mitigates Post-Reperfusion Syndrome and Perioperative Electrolyte Shifts.

(1) Background: Post-reperfusion syndrome (PRS) and electrolyte shifts (ES) represent considerable challenges during liver transplantation (LT) being associated with significant morbidity. We aimed to investigate the impact of hypothermic oxygenated machine perfusion (HOPE) on PRS and ES in LT. (2) Methods: In this retrospective study, we compared intraoperative parameters of 100 LTs, with 50 HOPE preconditioned liver grafts and 50 grafts stored in static cold storage (SCS). During reperfusion phase, prospectively registered serum parameters and vasopressor administration were analyzed. (3) Results: Twelve percent of patients developed PRS in the HOPE cohort vs. 42% in the SCS group (p = 0.0013). Total vasopressor demand in the first hour after reperfusion was lower after HOPE pretreatment, with reduced usage of norepinephrine (−26%; p = 0.122) and significant reduction of epinephrine consumption (−52%; p = 0.018). Serum potassium concentration dropped by a mean of 14.1% in transplantations after HOPE, compared to a slight decrease of 1% (p < 0.001) after SCS. The overall incidence of early allograft dysfunction (EAD) was reduced by 44% in the HOPE group (p = 0.04). (4) Conclusions: Pre-transplant graft preconditioning with HOPE results in higher hemodynamic stability during reperfusion and lower incidence of PRS and EAD. HOPE has the potential to mitigate ES by preventing hyperpotassemic complications that need to be addressed in LT with HOPE-pre-treated grafts.

Impact of early mean arterial pressure level on severe acute kidney injury occurrence after out-of-hospital cardiac arrest.

BACKGROUND: The optimal early mean arterial pressure (MAP) level in terms of renal function remains to be established in patients with out-of-hospital cardiac arrest (OHCA). We aimed to evaluate the association between early MAP level and severe acute kidney injury (AKI) occurrence in patients with OHCA. RESULTS: In 568 consecutive patients, the percentage time spent below a predefined MAP threshold and the corresponding area below threshold (ABT) were calculated from continuous MAP measurement. Both MAP-derived variables were calculated for different MAP thresholds (65, 75 and 85 mmHg) and time periods (the first 6 and 12 after ICU admission). 274 (48%) patients developed severe AKI defined as stage 3 of KDIGO. Both ABT and percentage time were independently associated with severe AKI, regardless of the MAP threshold and time period considered. Highest adjusted odds ratios for developing severe AKI were observed while considering the first 6 h period. Within the first 6 h, every 100 mmHg-h increase in ABT under MAP thresholds of 65, 75 and 85 mmHg increased severe AKI risk by 69% (OR = 1.69; 95% CI 1.26-2.26; p < 0.01), 13% (OR = 1.13; 95% CI 1.07-1.20; p < 0.01) and 4% (OR = 1.04; 95% CI 1.02-1.06; p < 0.01), respectively. Every 10% increase in percentage time spent under MAP thresholds of 65, 75 and 85 mmHg increased severe AKI risk by 19% (OR = 1.19; 95% CI 1.06-1.33; p < 0.01), 12% (OR = 1.12; 95% CI 1.04-1.19; p < 0.01) and 8% (OR = 1.08; 95% CI 1.02-1.14; p < 0.01), respectively. CONCLUSIONS: Both severity and duration of early arterial hypotension after ICU admission remained associated with severe AKI occurrence while considering a MAP threshold as high as 85 mmHg after OHCA.

Intraoperative dialysis with the use of a mobile dialysis system during liver transplantation.

PURPOSE: Over the last few years, transplant centers have started to use various intraoperative renal replacement therapy (ioRRT) modalities during liver transplantation (LT) in patients with pre-existing renal impairment. Here, we present a study on the safety and clinical outcomes of intraoperative hemodialysis (ioHD) performed using a mobile dialysis system during LT. PATIENTS AND METHODS: We retrospectively analyzed 102 adult patients undergoing LT with ioHD; pre-existing renal failure and/or intraoperative metabolic derangement were ioHD treatment indications. RESULTS: Our study cohort consisted of three groups: LT with preoperative serum creatinine (sCr) â€‹< â€‹2 â€‹mg/dL (Group 1:n â€‹= â€‹22), LT with preoperative sCr ≥2 â€‹mg/dL (Group 2:n â€‹= â€‹73), and simultaneous liver-kidney transplantation (Group 3:n â€‹= â€‹7). Among the procedures, 30% were re-transplantations. The mean calculated Model for End-stage Liver Disease score in Group 2 was 39.2, and 67% of patients were hospitalized in the intensive care unit. Patients in Group 1 were less acutely ill but developed severe intraoperative derangements and, therefore, underwent urgent ioHD intraoperatively. However, it was delayed when compared to Group 2. All groups achieved post-reperfusion potassium levels <4 â€‹mmol/L and a decrease in central venous pressure. No serious procedural complications occurred. Post-reperfusion syndrome occurred in 12.7% of patients. Elevated mortality was likely due to the high illness severity in the cohort. CONCLUSIONS: Performing ioHD with a mobile dialysis system during LT was safe and effective, while being easier to perform than continuous techniques. Its effect on intra- and postoperative outcomes should be addressed in a study with a control group.

[Ischemia-reperfusion syndrome]. / Sindrom ishemii-reperfuzii.

The ischemia-reperfusion syndrome complicates the course of a number of emergency conditions in various fields of clinical medicine, determines the course, prognosis and outcome of the disease. This review examines various aspects of the etiology, pathogenesis, and clinical manifestations of this syndrome. Particular attention is paid to its prevention and treatment. It is indicated that most of the studies devoted to this problem are of an experimental nature. The use of preparations based on succinic acid in the clinic is seen as the most promising direction in solving this issue.

Rare Case of Traumatic Anterior Knee Dislocation of Total Knee Arthroplasty With a Serious Neurovascular Injury.

Traumatic anterior dislocation of a total knee arthroplasty (TKA) is an extremely rare occurrence. There are only a few known cases of this type of dislocation which discuss the high risk of a neurovascular complication. This article describes a traumatic anterior dislocation of the TKA with a severe vascular lesion in a 75-year-old severely comorbid patient. Further complications led to the development of a compartment syndrome. Despite the repeated effort in performing a well-functioning anastomosis of the popliteal artery tear by the vascular surgeon, reperfusion of the lower extremity was not effective. Furthermore, multiorgan system failure due to the reperfusion syndrome evolved. This led to an above-knee amputation as a lifesaving procedure. Despite thorough intensive care therapy, the patient did not survive this complication. Presently there are no reported cases with such severe complications after the luxation of a previously well-functioning TKA leading to the death of the patient.

[Lymphotropic therapy in patients after surgical revascularization of lower-limb vessels]. / Limfotropnaia terapiia u bol'nykh posle khirurgicheskoi revaskuliarizatsii sosudov nizhnikh konechnostei.

Occlusive and stenotic lesions of lower-limb arteries appear to be amongst the most common manifestations of the pathology of the cardiovascular system and are characterized by various degree of chronic arterial insufficiency. Revascularization is the main stage of treatment for chronic arterial insufficiency of the lower extremities. Performing a reconstructive operation aimed at restoring the arterial blood flow in the ischaemized extremity is accompanied and followed by the development of reperfusion syndrome. The purpose of this study was to assess efficacy of using regional lymphotropic therapy for treatment of reperfusion syndrome in patients with chronic ischaemia of lower limbs in the postoperative period. The study included two groups of patients: the comparison group with standard postoperative treatment and the study group where the standard therapy was supplemented with regional lymphotropic therapy. In the postoperative period, the patients in both groups developed reperfusion oedema of the operated lower limb on day 3 after arterial reconstruction, however, on POD 7 after revascularization, the severity of oedema was apparently less in the study group. Lymphorrhoea after operative treatment in the study group was encountered significantly less often as compared with the control group. According to the findings of ultrasonographic examination of soft tissues in the postoperative period, patients of both groups on POD 3 were found to have pronounced oedema of soft tissues. However, on POD 7 the study group patients demonstrated a dramatic decrease in the thickness of oedema of the subcutaneous fat versus the comparison group patients. Regional lymphotropic therapy after reconstructive operations on arteries of lower limbs promoted a decrease in the severity of reperfusion syndrome on the operated lower limb.

Spinal reperfusion syndrome. A literature review and medicolegal implications.

Aim. To consider the diagnosis of spinal reperfusion syndrome (SRS) and its medicolegal implications.Materials and Methods. . A PRISMA guided PubMed search was performed to identify cases of possible SRS following spinal surgery.Result. Fourteen papers suggested that SRS might be the cause of neurological deterioration. In patients undergoing surgery for cervical degenerative disorders there were 7 patients who had new deficits immediately on awakening from the anaesthetic. There were 6 patients who had no new deficit immediately post-surgery with new deficits occurring within hours, or up to 3 days post-surgery.Conclusion. There is no agreed clinical definition of the SRS and the radiological abnormalities are not defined. The diagnosis of SRS can potentially be made by exclusion or inclusion. If there is a known cause of new neurological deficits intra- or immediately post-operatively, such as for example intraoperative cord injury, inadequate decompression or a haematoma, that is the probable diagnosis, not SRS. If a patient awakes with new deficits the most likely cause (if no other cause is identified) is intraoperative injury to the cord. If there is delayed deterioration with no cause identified SRS is a possible explanation. New deficits occur in 0.5 to 1.0% of patients undergoing anterior cervical spine surgery i.e. overall this is common whereas SRS is rare. The medicolegal implications are discussed.

Manejo del trauma vascular periférico en el servicio de cirugía cardiovascular del hospital Dr. Miguel Pérez Carreño. Estudio observacional / Management of peripheral vascular trauma in the cardiovascular surgery service of the Dr. Miguel Pérez Carreño hospital. observational study

El trauma se considera un problema de salud pública, siendo el trauma vascular un desafío para el cirujano de emergencia por su complejidad y morbimortalidad. Objetivo: Describir la experiencia en el manejo del trauma vascular periférico en el Servicio de Cirugía Cardiovascular del Hospital Dr. Miguel Pérez Carreño período enero 2.018 ­ enero 2.021. Métodos: Se realizó estudio retrospectivo, descriptivo, constituido por 410 pacientes, registrándose datos demográficos, mecanismo de lesión, tipos de lesión vascular, signos blandos y duros vasculares, grados de shock hipovolémico, vaso lesionado, procedimiento realizado, complicaciones y mortalidad. Se incluyeron 410 pacientes. La edad promedio fue 25,6 ± 18 años (14-72), sexo masculino en 89%. El mecanismo de lesión predominante fue el penetrante (92%), herida de arma de fuego (68%) y el trauma cerrado (7%). El diagnóstico fue clínico en 90% de los casos, el resto de la muestra fueron pacientes con lesiones crónicas como las fistulas AV y pseudoaneurismas. Las lesiones más frecuentes fueron en las extremidades inferiores (81%), extremidades superiores (17%) y cuello (2%). El tipo de lesión más común fue la transección arterial (49%) y lesión parcial (20%). Se presentó shock hipovolémico en 60% de los casos. La femoral superficial fue la más lesionada (70%) seguida de la poplítea (20%), la lesión asociada fue la fractura de huesos largos en un 30%. Se realizó interposición venosa autóloga en 89% de los casos. La infección de sitio operatorio registrada fue de 15% y la mortalidad de 0.4%. Conclusiones: El diagnóstico oportuno y manejo adecuado del trauma vascular demostró baja tasa de morbimortalidad y resultados favorables, incluso realizando reparación primaria, sin diferencia por grado de shock ni uso de shunt(AU)

Trauma is considered a public health problem, with vascular trauma being a challenge for the emergency surgeon due to its complexity, morbidity and mortality. Objetive: To describe the experience in the management of peripheral vascular trauma in the cardiovascular surgery department at Dr. Miguel Perez Carreño Hospital period January 2.018 - January 2.021. Methods: A retrospective, transversal and descriptive study was conducted, consisting of 410 patients, registering demographic data, injury mechanism, types of vascular injury, soft and hard vascular signs, degrees of hypovolemic shock, injured vessel, procedure performed, complications, and mortality. Results: 410 patients were included. The average age was 25.6 ± 18 years (14-72), 365 male (89%). The predominant injury mechanism was penetrating (92 %), gunshot wound (68%), and blunt trauma (7%). diagnosis by clinical in (90%), the rest of the sample was reserved for patients with chronic lesions such as AV fistulas and pseudoaneurysms. The most frequent lesions were in the lower extremities (81 %), upper extremities (17 %), and neck (2 %). The most common type of lesions were arterial transection (49%) and partial lesion (20%). Hypovolemic shock was present in (60%) of the cases. The superficial femoral artery was the most injured (70%) followed by the popliteal artery (20%), the associated injured was long bone fracture (30%). autologous venous interposition was performed in (89%) of cases. Registered surgical site infection was (15%) and mortality of 2 patients (0.4%). Conclusions: The timely diagnosis and proper management of vascular trauma showed a low rate of morbidity and mortality and favorable results, even carrying out primary repair, without difference by degree of shock or use of shunts(AU)

[Reperfusion syndrome: state of the art]. / Reperfuzionnyi sindrom. Sovremennoe sostoianie problemy.

Reperfusion syndrome is a complex series of clinical manifestations resulting from restoration of blood flow to previously ischaemic tissues. It is accompanied by damage to cells, tissues and organs at various levels, followed by the development of multiple organ failure. This review deals with the main pathophysiological mechanisms of the development of reperfusion syndrome in lesions of cardiac, cerebral and lower-limb vessels. Oxidative stress is considered to be the most important marker of ischaemia-reperfusion injury irrespective of the type of tissues affected. Presented herein are the data on contemporary possibilities of influencing various stages and components of the development of reperfusion injury by means of drug therapy, demonstrating that due to the importance of oxidative stress as a key link of reperfusion injury, antioxidant therapy should be the main component of prevention and treatment of reperfusion injury.

Post-resuscitation shock: recent advances in pathophysiology and treatment.

A post-resuscitation shock occurs in 50-70% of patients who had a cardiac arrest. It is an early and transient complication of the post-resuscitation phase, which frequently leads to multiple-organ failure and high mortality. The pathophysiology of post-resuscitation shock is complex and results from the whole-body ischemia-reperfusion process provoked by the sequence of circulatory arrest, resuscitation manoeuvers and return of spontaneous circulation, combining a myocardial dysfunction and sepsis features, such as vasoplegia, hypovolemia and endothelial dysfunction. Similarly to septic shock, the hemodynamic management of post-resuscitation shock is based on an early and aggressive hemodynamic management, including fluid administration, vasopressors and/or inotropes. Norepinephrine should be considered as the first-line vasopressor in order to avoid arrhythmogenic effects of other catecholamines and dobutamine is the most established inotrope in this situation. Importantly, the optimal mean arterial pressure target during the post-resuscitation shock still remains unknown and may probably vary according to patients. Mechanical circulatory support by extracorporeal membrane oxygenation can be necessary in the most severe patients, when the neurological prognosis is assumed to be favourable. Other symptomatic treatments include protective lung ventilation with a target of normoxia and normocapnia and targeted temperature management by avoiding the lowest temperature targets. Early coronary angiogram and coronary reperfusion must be considered in ST-elevation myocardial infarction (STEMI) patients with preserved neurological prognosis although the timing of coronary angiogram in non-STEMI patients is still a matter of debate. Further clinical research is needed in order to explore new therapeutic opportunities regarding inflammatory, hormonal and vascular dysfunction.

Systolic anterior motion of mitral chordae tendineae: prevalence and clinical implications in liver transplantation.

BACKGROUND: Although systolic anterior motion (SAM) of the mitral valve anterior leaflet is well-known to cause hemodynamic perturbation in many anesthetic situations, the prevalence and clinical implication of SAM of mitral chordae tendineae (chordal SAM) in liver transplantation (LT) has not been evaluated. We aimed to assess the impact of chordal SAM on intraoperative postreperfusion syndrome and short and long-term all-cause mortality. METHODS: We retrospectively evaluated 1751 LT recipients from January 2011 to June 2017 who had preoperative echocardiography. Echocardiography-derived parameters and the prevalence of post-reperfusion syndrome between those with chordal SAM and without chordal SAM were compared. The cumulative mortality rate according to the presence of chordal SAM was evaluated by the Kaplan-Meier survival curve. RESULTS: Of the enrolled recipients, 21 (1.2%) had chordal SAM in preoperative echocardiography. Compared to those without chordal SAM, patients with chordal SAM had a smaller end-systolic volume index (median 18 ml/m2 vs. 22 ml/m2, P = 0.015) and end-diastolic volume index (median 52 ml/m2 vs. 63 ml/m2, P = 0.011). However, there was no difference in systolic and diastolic function in echocardiography. The prevalence of intraoperative post-reperfusion syndrome did not show any difference (42.9% vs. 45.3%, P = 1.000). Over the mean 4.8-year follow-up, cumulative 90-day and overall mortality also did not show a difference (Log rank P > 0.05, both). CONCLUSIONS: Preoperative screening of echocardiography in LT recipients detects 1.2% of chordal SAM. It is found with small left ventricular volume, but is not related with intraoperative post-reperfusion syndrome and short- and long-term postoperative all-cause mortality in LT.

Impact of the venting via vena cava inferior on the outcome of liver transplantation.

BACKGROUND: The liver transplantation is a standard treatment method for the indicated group of patients with a final hepatic failure. The aim of this paper was to compare two reperfusion methods of implanted liver, non-venting and venting vena cava, and to evaluate the impact of both techniques on the post reperfusion syndrome. METHODS: We compared two groups of patients: non-venting (n = 42) and venting (n = 41). We monitored bilirubin, liver enzymes and hemodynamic changes after reperfusion. We recorded monitored parameters immediately prior to the transplantation, during and after the reperfusion and on the 1st postoperative day. All liver grafts were used from the donors after a brain death. RESULTS: We did not find a statistically significant difference in input monitored parameters. We detected significant changes of pH after reperfusion in both monitored groups. We determined a significantly better saturation in the non-venting group, bigger consumption of fresh frozen plasma and thrombo-concentrate in the non-venting group, a significantly higher value of total bilirubin and a lower value of Quick's time in the non-venting group. CONCLUSION: Venting via vena cava inferior did not impact the perioperative and early postoperative course of liver transplantation in our group of patients. However, further analyses are required (Tab. 2, Fig. 3, Ref. 20).

Anaesthesia for Liver Transplantation: An Update.

Liver transplantation (LT) is a challenging surgery performed on patients with complex physiology profiles, complicated by multi-system dysfunction. It represents the treatment of choice for end-stage liver disease. The procedure is performed under general anaesthesia, and a successful procedure requires an excellent understanding of the patho-physiology of liver failure and its implications. Despite advances in knowledge and technical skills and innovations in immunosuppression, the anaesthetic management for LT can be complicated and represent a real challenge. Monitoring devices offer crucial information for the successful management of patients. Hemodynamic instability is typical during surgery, requiring sophisticated invasive monitoring. Arterial pulse contour analysis and thermo-dilution techniques (PiCCO), rotational thromboelastometry (RO-TEM), transcranial doppler (TCD), trans-oesophageal echocardiography (TEE) and bispectral index (BIS) have been proven to be reliable monitoring techniques playing a significant role in decision making. Anaesthetic management is specific according to the three critical phases of surgery: pre-anhepatic, anhepatic and neo-hepatic phase. Surgical techniques such as total or partial clamping of the inferior vena cava (IVC), use of venovenous bypass (VVBP) or portocaval shunts have a significant impact on cardiovascular stability. Post reperfusion syndrome (PRS) is a significant event and can lead to arrhythmias and even cardiac arrest.

[Endovascular surgery for acute mesenteric ischemia]. / Éndovaskuliarnaia khirurgiia ostrogo arterial'nogo narusheniia mezenterial'nogo krovoobrashcheniia: podkhody k lecheniiu.

OBJECTIVE: To demonstrate the results of endovascular treatment of 15 patients with acute mesenteric ischemia. MATERIAL AND METHODS: There were 15 patients with acute mesenteric ischemia who underwent surgery (9 men and 6 women). Mean age was 77±11 years. Acute intestinal ischemia was caused by thromboembolism of superior mesenteric artery (9 patients), thrombosis of superior mesenteric artery (5 patients) and critical stenosis of the ostia of superior mesenteric artery and celiac trunk (1 patient). Mean time from clinical manifestation of disease to admission to the hospital was 13 hours (range 2-72 hours). In-hospital development of acute mesenteric ischemia was noted in 2 patients. Indications for endovascular intervention and techniques of endovascular revascularization of superior mesenteric artery are described in the article. RESULTS: Blood flow restoration in superior mesenteric artery was achieved in 14 (93%) out of 15 patients. Laparotomy was required in 4 (27%) patients for extensive resection of necrotic intestine (n=1, 6.7%), local resection of small bowel (n=2, 13%). In another (6.7%) patient, intestine was recognized as viable after laparotomy. A bulk of intestine was preserved in most patients (n=14, 93%). In-hospital mortality rate was 47% (7 patients died). The main cause of nosocomial death (6 cases) was reperfusion syndrome followed by respiratory distress syndrome and multiple organ failure. CONCLUSION: New methods of prevention and treatment of reperfusion syndrome can improve the results of treatment of acute mesenteric ischemia.

Extracellular Vesicles as Mediators of Cellular Crosstalk Between Immune System and Kidney Graft.

Extracellular vesicles (EVs) are known immune-modulators exerting a critical role in kidney transplantation (KT). EV bioactive cargo includes graft antigens, costimulatory/inhibitory molecules, cytokines, growth factors, and functional microRNAs (miRNAs) that may modulate expression of recipient cell genes. As paracrine factors, neutrophil- and macrophage-derived EVs exert immunosuppressive and immune-stimulating effects on dendritic cells, respectively. Dendritic cell-derived EVs mediate alloantigen spreading and modulate antigen presentation to T lymphocytes. At systemic level, EVs exert pleiotropic effects on complement and coagulation. Depending on their biogenesis, they can amplify complement activation or shed complement inhibitors and prevent cell lysis. Likewise, endothelial- and platelet-derived EVs can exert procoagulant/prothrombotic effects and also promote endothelial survival and angiogenesis after ischemic injury. Kidney endothelial- and tubular-derived EVs play a key role in ischemia-reperfusion injury (IRI) and during the healing process; additionally, they can trigger rejection by inducing both alloimmune and autoimmune responses. Endothelial EVs have procoagulant/pro-inflammatory effects and can release sequestered self-antigens, generating a tissue-specific autoimmunity. Renal tubule-derived EVs shuttle pro-fibrotic mediators (TGF-ß and miR-21) to interstitial fibroblasts and modulate neutrophil and T-lymphocyte influx. These processes can lead to peritubular capillary rarefaction and interstitial fibrosis-tubular atrophy. Different EVs, including those from mesenchymal stromal cells (MSCs), have been employed as a therapeutic tool in experimental models of rejection and IRI. These particles protect tubular and endothelial cells (by inhibition of apoptosis and inflammation-fibrogenesis or by inducing autophagy) and stimulate tissue regeneration (by triggering angiogenesis, cell proliferation, and migration). Finally, urinary and serum EVs represent potential biomarkers for delayed graft function (DGF) and acute rejection. In conclusion, EVs sustain an intricate crosstalk between graft tissue and innate/adaptive immune systems. EVs play a major role in allorecognition, IRI, autoimmunity, and alloimmunity and are promising as biomarkers and therapeutic tools in KT.