The applications of ECMO in liver transplant recipients.

Extracorporeal membrane oxygenation (ECMO) has emerged as a vital instrument for sustaining respiratory and cardiac functions when traditional methods have failed. Its function in managing acute pulmonary and cardiac challenges during liver transplantation (LT) has expanded significantly. While ECMO was initially viewed as a rescue strategy for acute intraoperative or posttransplant complications, its application now also encompasses the pretransplant stage of LT. Our review aims to thoroughly summarize both research and specific cases where ECMO has been utilized across pre- and perioperative phases in liver transplant recipients. By assessing the published literature, we discuss specific indications, the types of ECMO employed, their outcomes, and the unique challenges of applying ECMO during LT. In particular, the pretransplant use of ECMO is increasing, and its prudent introduction prior to LT, supported by meticulous planning, has the potential to optimize patient outcomes. It is challenging to manage liver transplant patients on ECMO. More research and experience are needed to refine the techniques and improve patient outcomes. Furthermore, decision-making must be tailored to each patient's unique circumstances, and a clear, practical, and well-defined plan for subsequent steps is essential.

Preoperative risk factors for unexpected postoperative intensive care unit admission: A retrospective case analysis.

INTRODUCTION: The purpose of this retrospective case-control study was to investigate preoperative risk factors for unexpected postoperative intensive care unit (ICU) admissions in patients undergoing non-emergent surgical procedures in a tertiary medical centre. METHODS: A medical record review of adult patients undergoing elective non-cardiac and non-transplant major surgical procedures during the period of January 2011 through December 2015 in the operating rooms of a large university hospital was carried out. The primary outcome assessed was unexpected ICU admission, with mortality as a secondary outcome. Demographic data, length of hospital and ICU stay and preoperative comorbidities were also obtained as exposure variables. Propensity score matching was then employed to yield a study and control group. RESULTS: The group of patients who met inclusion criteria in the study and the control group that did not require ICU admission were obtained, each containing 1191 patients after propensity matching. Patients with acute and/or chronic kidney injury (odds ratio (OR) 2.20 [1.75-2.76]), valvular heart disease (OR: 1.94 [1.33-2.85]), peripheral vascular disease (PVD) (OR: 1.41 [1.02-1.94]) and congestive heart failure (CHF) (OR: 1.80 [1.31-2.46]) were all associated with increased unexpected ICU admission. History of cerebrovascular accident (CVA) (OR: 3.03 [1.31-7.01]) and acute and/or chronic kidney injury (OR: 1.62 [1.12-2.35]) were associated with increased mortality in all patients; CVA was also associated with increased mortality (OR: 3.15 [1.21-8.20]) specifically in the ICU population. CONCLUSIONS: CHF, acute/chronic kidney injury, PVD and valve disease were significantly associated with increased unexpected ICU admission; patients with CVA suffered increased mortality when admitted to the ICU.

Significance of oliguria in critically ill patients with chronic liver disease.

Clinical guidelines recommend using Kidney Disease Improving Global Outcomes (KDIGO) criteria for the diagnosis and classification of acute kidney injury (AKI) in patients with chronic liver disease (CLD). Concerns have been raised about the use of urine output (UO) criteria in CLD. We examined the significance of oliguria meeting the urine output criteria for AKI (AKI-UO) and examined its association with clinical outcomes in CLD patients. Using an 8-year clinical database from a large university medical center, 3458 patients with CLD were identified. AKI occurred in 2854 (82.5%) patients when they fulfilled any KDIGO criteria. When serum creatinine (SC) and UO criteria were used, 604 patients (17.5%) had no evidence of AKI and had the lowest hospital mortality rate (5%). Using AKI-UO criteria alone, 2103 patients (60.8%) were classified as stage 2-3 AKI. When only SC criteria were applied, 1281 (61%) of those patients with stage 2-3 AKI-UO were misclassified as either no AKI or AKI stage 1. Patients reclassified with AKI according to UO criteria (AKI-UO) had nearly a 3-fold increased rate of hospital mortality compared with patients without any AKI (14.6% versus 5%; P < 0.001) and more than a 50% increased mortality compared with stage 1 AKI-SC (14.6% versus 9%; P < 0.001). Patients with transient oliguria (AKI-UO stage 1) had increased mortality rates compared with patients without oliguria (14.9% versus 6.9%; P < 0.001). CONCLUSION: CLD patients have a high incidence of AKI. Compared with creatinine criteria alone, incorporating UO into the diagnostic criteria increased the measured incidence of AKI. Stage 2-3 AKI-UO has a high negative impact on hospital mortality. (Hepatology 2017;66:1592-1600).

Pulmonary Hypertensive Crisis on Induction of Anesthesia.

Anesthesia for lung transplantation remains one of the highest risk surgeries in the domain of the cardiothoracic anesthesiologist. End-stage lung disease, pulmonary hypertension, and right heart dysfunction as well as other comorbid disease factors predispose the patient to cardiovascular, respiratory and metabolic dysfunction during general anesthesia. Perhaps the highest risk phase of surgery in the patient with severe pulmonary hypertension is during the induction of anesthesia when the removal of intrinsic sympathetic tone and onset of positive pressure ventilation can decompensate a severely compromised cardiovascular system. Severe hypotension, cardiac arrest, and death have been reported previously. Here we present 2 high-risk patients for lung transplantation, their anesthetic induction course, and outcomes. We offer suggestions for the safe management of anesthetic induction to mitigate against hemodynamic and respiratory complications.

Liberation From Renal Replacement Therapy After Cadaveric Liver Transplantation.

BACKGROUND: Renal failure requiring renal replacement therapy (RRT) is common in patients with end-stage liver disease (ESLD) and is associated with worse outcomes following liver transplantation (LT). We investigated the factors associated with liberation from posttransplant RRT and studied the impact of RRT on patient and graft outcomes. METHODS: A 5-year retrospective study of ESLD patients who received pretransplant RRT was conducted. Variables associated with liberation from RRT at 30 days and at 1-year posttransplant were analyzed. We used propensity matching to compare patient and graft outcomes in the study cohort to those of a control group who underwent LT but not pretransplant RRT. RESULTS: Sixty-four patients were included in the study. Twenty-four (38%) were liberated from RRT at 30 days posttransplant. Duration of pretransplant RRT (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.89-0.98) and severe postreperfusion syndrome (OR, 0.26; 95% CI, 0.08-0.87) were significantly associated with continued RRT at 1-month posttransplant. At one year, 34 (53%) patients were liberated from RRT. Age was significantly associated with lack of liberation from RRT (OR, 0.933; 95% CI, 0.875-0.995). Compared with propensity matched controls, patients who received RRT pretransplant had worse graft and patient survival at 1 year (52% vs 82%; P = 0.01, and 53% vs 83%; P = 0.003, respectively). CONCLUSIONS: In ESLD patients who received pretransplant RRT, one third were liberated from RRT at 1 month, and half at 1 year. Longer duration of pretransplant RRT, postreperfusion syndrome, and older age were associated with lower likelihood of liberation from RRT. Patients who required pretransplant RRT had worse graft and patient survivals compared to matched patients who did not require RRT. Patients who were liberated from RRT post-LT had similar outcomes to patients who never required pre-LT RRT.

Acute kidney injury after orthotopic liver transplantation using living donor versus deceased donor grafts: A propensity score-matched analysis.

Acute kidney injury (AKI) is a common complication after liver transplantation (LT). Few studies investigating the incidence and risk factors for AKI after living donor liver transplantation (LDLT) have been published. LDLT recipients have a lower risk for post-LT AKI than deceased donor liver transplantation (DDLT) recipients because of higher quality liver grafts. We retrospectively reviewed LDLTs and DDLTs performed at the University of Pittsburgh Medical Center between January 2006 and December 2011. AKI was defined as a 50% increase in serum creatinine (SCr) from baseline (preoperative) values within 48 hours. One hundred LDLT and 424 DDLT recipients were included in the propensity score matching logistic model on the basis of age, sex, Model for End-Stage Liver Disease score, Child-Pugh score, pretransplant SCr, and preexisting diabetes mellitus. Eighty-six pairs were created after 1-to-1 propensity matching. The binary outcome of AKI was analyzed using mixed effects logistic regression, incorporating the main exposure of interest (LDLT versus DDLT) with the aforementioned matching criteria and postreperfusion syndrome, number of units of packed red blood cells, and donor age as fixed effects. In the corresponding matched data set, the incidence of AKI at 72 hours was 23.3% in the LDLT group, significantly lower than the 44.2% in the DDLT group (P = 0.004). Multivariate mixed effects logistic regression showed that living donor liver allografts were significantly associated with reduced odds of AKI at 72 hours after LT (P = 0.047; odds ratio, 0.31; 95% confidence interval, 0.096-0.984). The matched patients had lower body weights, better preserved liver functions, and more stable intraoperative hemodynamic parameters. The donors were also younger for the matched patients than for the unmatched patients. In conclusion, receiving a graft from a living donor has a protective effect against early post-LT AKI.

Diagnostic dilemma of coagulation problems in an HIV-positive patient with end-stage liver disease undergoing liver transplantation.

Human immunodeficiency virus (HIV) may result in devastating multi-organ complications, including cirrhosis. Consequently, liver transplantation is often required for these patients. We report a case of a 43-year-old female with cryptogenic cirrhosis and HIV on highly active antiretroviral therapy, presenting for non-related living donor liver transplantation. The intra-operative course was complicated by hepatic artery and portal vein thrombosis, requiring thrombectomy. On postoperative day-3, the patient required re-transplantation with a cadaveric donor organ due to primary graft failure.

Complications related to invasive hemodynamic monitors during adult liver transplantation.

The rate of complications directly related to invasive monitors during liver transplantation (LT) was reviewed in 1206 consecutive adult LTs performed over 8.6 yr (1/1/2004-7/31/2012). The designated anesthesiologists placed intra-operative monitors, including two arterial catheters (via the radial and the right femoral arteries), central venous catheters (a 9 Fr. catheter and an 18 Fr. veno-venous bypass [VVB] return cannula in an internal jugular vein), a pulmonary artery catheter, and a transesophageal echocardiography (TEE) probe. A 17 Fr. VVB drainage cannula was placed via the left femoral vein. No Clavien-Dindo Grade V (death) or Grade IV (organ dysfunction) complication was identified. Nine Grade III complications (requiring surgical intervention) and 15 Grade II complications (conservative treatment) were noted. Seven (0.58% in 1206 cases) were related to a femoral arterial line with Grade III of four; seven (0.58%) were due to VVB return cannula in the femoral vein with Grade III of one; four (0.33%) were related to central venous catheters with Grade III of two; four (0.33%) were due to a TEE probe with Grade III of two; and two minor complications (0.17%) that were related to a radial arterial line. No complication was observed with a pulmonary arterial catheter. Current invasive monitors placed during LT have an acceptable risk.

Cardiac arrest during adult liver transplantation: a single institution's experience with 1238 deceased donor transplants.

Liver transplantation (LT) is one of the highest risk noncardiac surgeries. We reviewed the incidence, etiologies, and outcomes of intraoperative cardiac arrest (ICA) during LT. Adult cadaveric LT recipients from January 1, 2001 through December 31, 2009 were reviewed. ICA was defined as an event requiring either closed chest compression or open cardiac massage. Cardiac arrest patients who recovered with only pharmacological interventions were excluded. Data included etiologies and outcomes of ICA, intraoperative deaths (IDs) and hospital deaths (HDs), and potential ICA risk factors. ICA occurred in 68 of 1238 LT recipients (5.5%). It occurred most frequently during the neohepatic phase (60 cases or 90%), and 39 of these cases (65.0%) experienced ICA within 5 minutes after graft reperfusion. The causes of ICA included postreperfusion syndrome (PRS; 26 cases or 38.2%) and pulmonary thromboembolism (PTE; 24 cases or 35.3%). A higher Model for End-Stage Liver Disease (MELD) score was found to be the most significant risk factor for ICA. The ID rate after ICA was 29.4% (20 cases), and the HD rate was 50.0% (34 cases). The 30-day patient survival rate after ICA was 55.9%, and the 1-year survival rate was 45.6%: these rates were significantly lower (P < 0.001) than those for non-ICA patients (97.4% and 85.1%, respectively). In conclusion, the incidence of ICA in adult cadaveric LT was 5.5% with an intraoperative mortality rate of 29.4%. ICA most frequently occurred within 5 minutes after reperfusion and resulted mainly from PRS and PTE. A higher MELD score was identified as a risk factor.

Isolated small bowel transplantation outcomes and the impact of immunosuppressants: Experience of a single transplant center.

AIM: To investigate patient and graft outcomes in isolated small bowel transplant (SBTx) recipients and immunosuppressant induction agent impact on outcomes. METHODS: A retrospective review of the perioperative data of patients who underwent SBTx transplant during an 8-year period was conducted. The intraoperative data were: patient demographics, etiology of short gut syndrome, hemodynamic parameters, coagulation profiles, intraoperative fluid and blood products transfused, and development of post-reperfusion. The postoperative data were: hospital/intensive care unit stays, duration of mechanical ventilation, postoperative incidence of acute kidney injury, and 1-year patient and graft outcomes. The effects of the three immunosuppressant induction agents (Zenapax, Thymoglobulin, Campath) on patient and graft outcomes were reviewed. RESULTS: During the 8-year period there were 77 patients; 1-year patient and graft survival were 95% and 86% respectively. Sixteen patients received Zenapax, 22 received Thymoglobulin, and 39 received Campath without effects on patient or graft survival (P = 0.90, P = 0.14, respectively). The use of different immune induction agents did not affect the incidence of rejection and infection during the first 90 postoperative days (P = 0.072, P = 0.29, respectively). The Zenapax group received more intraoperative fluid and blood products and were coagulopathic at the end of surgery. Zenapax and Thymoglobulin significantly increased serum creatinine at 48 h (P = 0.023) and 1 wk (P = 0.001) post-transplant, but none developed renal failure or required dialysis at the end of the first year. CONCLUSION: One-year patient and graft survival were 95% and 86%, respectively. The use of different immunosuppressant induction agents may affect the intraoperative course and short-term postoperative morbidities, but not 1-year patient and graft outcomes.

Anesthetic management in upper extremity transplantation: the Pittsburgh experience.

BACKGROUND: Hand/forearm/arm transplants are vascularized composite allografts, which, unlike solid organs, are composed of multiple tissues including skin, muscle, tendons, vessels, nerves, lymph nodes, bone, and bone marrow. Over the past decade, 26 upper extremity transplantations were performed in the United States. The University of Pittsburgh Medical Center has the largest single center experience with 8 hand/forearm transplantations performed in 5 recipients between January 2008 and September 2010. Anesthetic management in the emerging field of upper extremity transplants must address protocol and procedure-specific considerations related to the role of regional blocks, effects of immunosuppressive drugs during transplant surgery, fluid and hemodynamic management in the microsurgical setting, and rigorous intraoperative monitoring during these often protracted procedures. METHODS: For the first time, we outline salient aspects of upper extremity transplant anesthesia based on our experience with 5 patients. We highlight the importance of minimizing intraoperative vasopressors and improving fluid management and blood product use. RESULTS: Our approach reduced the incidence of perioperative bleeding requiring re-exploration or hemostasis and shortened in-hospital and intensive care unit stay. Functional, immunologic and graft survival outcomes have been highly encouraging in all patients. CONCLUSIONS: Further experience is required for validation or standardization of specific anesthetic protocols. Meanwhile, our recommendations are intended as pertinent guidelines for centers performing these novel procedures.

Live liver donors: Are they at a higher risk for post-operative thrombotic complications?

Live liver donor transplantation to adult recipients is becoming a common practice, increasing the organ pool and providing an alternative to whole cadaveric liver transplantation. These patients are healthy adults without serious medical conditions and typically have normal coagulation profiles preoperatively. Right hepatic lobectomy is usually performed for adult recipients, while left hepatic lobectomy is performed for pediatric recipients. Removal of the whole right lobe from the donors may expose theses patients to multiple intraoperative and postoperative complications. Hypercoagulability has been identified as a serious complication which leads to thromboembolic phenomena with potential fatal consequences. The primary aim of this review is to look at possible changes in post-operative coagulation dynamics that may increase the risk for development of thromboembolic complications in live liver donors. In this article, we stress the importance of addressing the issue that conventional clotting tests (PT, INR, PTT) are unable to detect a hypercoagulable state, and therefore, we should examining alternative laboratory tests to improve diagnosis and early detection of thrombotic complications. Measurement of natural anticoagulant/procoagulant biomarkers combined with conventional coagulation studies and thromboelastography offers a more accurate assessment of coagulation disorders. This allows earlier diagnosis, permitting appropriate intervention sooner, hence avoiding potential morbidity and mortality. Biomarkers that may be evaluated include, but are not limited to: protein C, soluble P-selectin, antithrombin III, thrombin-antithrombin complex, and thrombin generation complex.

Accidental insertion of a percutaneous venovenous cannula into the persistent left superior vena cava of a patient undergoing liver transplantation.

PURPOSE: Persistent left superior vena cava (PLSVC) is a rare congenital vascular abnormality found in 0.3% of the general population. We report herein a rare complication involving the accidental insertion of a large bore cannula into the PLSVC during liver transplantation (LT). CLINICAL FEATURES: A 63-yr-old man with primary sclerosing cholangitis presented for LT. Given the existence of a tunnelled dialysis catheter in the right internal jugular vein (IJV) and a triple lumen catheter via the left IJV, insertion of an 18 French cannula for venovenous bypass (VVB) was performed via the left IJV using the existing triple lumen cannula as a conduit for a guidewire. Upon initiation of VVB, profound systemic hypotension occurred, and liver transplantation was completed without the further use of VVB. A chest x-ray confirmed a malposition of the VVB cannula with a large left hemothorax. A mini-sternotomy was performed for removal of the VVB cannula, which was found to be inserted in the PLSVC. Retrospectively, the presence of PLSVC was not anticipated due to a normal superior vena cava and a left innominate vein, as revealed by the course of a pre-existing left internal jugular vein triple lumen catheter on a preoperative chest x-ray, and due to a normal-sized coronary sinus on preoperative echocardiography. CONCLUSION: Malpositioning of a venous cannula in a PLSVC should be anticipated as one of the potential complications of vascular access via the left internal jugular vein.

Perioperative pulmonary aspiration of patients who have had an esophagectomy with a gastric pull-up: the value of preoperative computed tomography of the neck.

Patients who have had an esophagectomy with gastric pull-up are at a higher risk for perioperative pulmonary aspiration due to loss of the esophageal sphincter. Altered neck anatomy following esophagectomy may render the conventional cricoid pressure maneuver unreliable in preventing pulmonary aspiration during induction of general anesthesia. Two patients who suffered perioperative pulmonary aspiration are presented. Retrospective review of their preoperative computed tomography of the neck showed the altered anatomical position of the esophago-gastric connection, causing the cricoid pressure to be ineffective.

Comparison of surgical methods in liver transplantation: retrohepatic caval resection with venovenous bypass (VVB) versus piggyback (PB) with VVB versus PB without VVB.

Use of piggyback technique (PB) and elimination of venovenous bypass (VVB) have been advocated in adult liver transplantation (LT). However, individual contribution of these two modifications on clinical outcomes has not been fully investigated. We performed a retrospective review of 426 LTs within a 3-year period, when three different surgical techniques were employed per the surgeons' preference: retrohepatic caval resection with VVB (RCR+VVB) in 104 patients, PB with VVB (PB+VVB) in 148, and PB without VVB (PB-Only) in 174. The primary outcomes were intraoperative blood transfusion and the patient and graft survivals. Demographic profiles were similar, except younger recipient age in RCR+VVB and fewer number of grafts with cold ischemic time over 16 h in PB-Only. PB-Only required lesser intraoperative red blood cells (P=0.006), fresh frozen plasma (P=0.005), and cell saver return (P=0.007); had less incidence of acute renal failure (P=0.001), better patient survival (P=0.039), and graft survival (P=0.003). The benefits of PB+VVB were only found in shortened total surgical time (P=0.0001) and warm ischemic time (P=0.0001), and less incidence of acute renal failure (P=0.001) than RCR+VVB. PB-Only method seemed to provide the best clinical outcome. The benefit of PB was not fully achieved when it was used with VVB.

N-acetylcysteine does not prevent hepatorenal ischaemia-reperfusion injury in patients undergoing orthotopic liver transplantation.

BACKGROUND: Glutathione (GSH) acts as a free radical scavenger that may be helpful in preventing reperfusion injury. N-acetylcysteine (NAC) replenishes GSH stores. The aims of this study were to evaluate the efficacy of NAC in improving liver graft performance and reducing the incidence of post-operative acute kidney injury (AKI). METHODS: Our study was a randomized, double-blind, placebo-controlled trial of 100 patients; 50 received placebo and 50 received a loading dose of 140 mg/kg of intravenous (IV) NAC over 1 h followed by 70 mg/kg IV repeated every 4 h for a total of 12 doses. Both groups were followed up for 1 year post-orthotopic liver transplant (OLT). We recorded liver function tests, renal function tests, graft survival, patient survival, plasma GSH and duration of hospital and ICU stay. In addition to serum creatinine (SCr) levels, we analysed cystatin C and beta-trace as independent measures of glomerular filtration. All clinical data were recorded daily for the first week after the surgery, then on Days 14, 21, 30, 90 and 180 and at the end of the first year. RESULTS: IV NAC did not affect survival, graft function or risk of AKI. However, GSH levels were highly variable with only 50% of patients receiving NAC exhibiting increased levels and fewer patients developed AKI when GSH levels were increased. Additional risk factors for AKI in the post-transplant period were female gender (P = 0.05), increased baseline serum bilirubin (P = 0.004) and increased baseline SCr levels (P = 0.02). CONCLUSIONS: IV NAC was not effective in reducing renal or hepatic injury in the setting of liver transplantation. The dose and duration of NAC used, though higher than most renal protection studies, may have been ineffective for raising GSH levels in some patients.

Safety and efficacy of tranexamic acid compared with aprotinin in thoracic aortic surgery with deep hypothermic circulatory arrest.

OBJECTIVES: This study was conducted to evaluate the safety and efficacy of high-dose tranexamic acid (TA) compared with aprotinin in patients who underwent thoracic aortic surgery with deep hypothermic circulatory arrest (DHCA). DESIGN: A retrospective study. PARTICIPANTS: Eighty-four patients underwent thoracic aortic surgery with DHCA arrest between July 2006 and December 2007. Antifibrinolytic efficacy and perioperative outcomes were compared between the groups by appropriate statistical tests. MEASUREMENTS AND MAIN RESULTS: Demographic data, comorbid conditions, aortic pathology, surgical procedures, and operative data were comparable between groups. The use of blood products tended to be more in the TA group, despite the fact that the aprotinin group had longer CPB duration. Thirty-day mortality was 5 of 48 (10.4%) in the aprotinin group versus 5 of 36 (13.9%) in the TA group (p = 0.44). Neurologic, cardiac, and respiratory dysfunctions were comparable as well as intensive care unit and hospital stay. Serum creatinine increased significantly postoperatively in both groups, with more patients in the aprotinin group developing stage 1 postoperative renal dysfunction based on Acute Kidney Insufficiency Network criteria. Multivariate logistic regression analysis identified risk factors for postoperative renal dysfunction including preoperative creatinine clearance, blood transfusion, and sepsis. Throughout the study, both drugs were available for use, allowing selective bias for providers. CONCLUSIONS: Aprotinin appeared more effective in reducing blood product use after thoracic aortic surgery in this limited cohort. Aprotinin use also appeared to be associated with postoperative renal dysfunction. The choice of antifibrinolytic appeared to not be associated with cardiac, neurologic, or respiratory outcomes or survival after thoracic aortic surgery requiring DHCA.