Portal hypertension has no role in perioperative bleeding during liver transplantation with systematic porto-caval shunt.

BACKGROUND: More than a half of patients undergoing liver transplantation (LT) receive intraoperative transfusion. Portal hypertension (PHT) may contribute to perioperative blood loss. We study the relationship between preoperative hepatic venous pressure gradient (HVPG) values and intraoperative transfusion requirements in adult patients undergoing LT. METHODS: 160 cirrhotic patients undergoing first elective LT (2009-2019) with an HVPG measurement within the previous 6 months were included. Surgical technique was piggyback with portocaval shunt (PCS). The association of HVPG and other variables with transfusion requirements and blood loss were studied. RESULTS: Blood loss (ml/kg) was positively correlated with HVPG, among other variables, but at multivariable analysis it only remained associated with MELD-Na and HCC indication. Regarding RBC transfusion, MELD-Na and hemoglobin were independently associated with the need and magnitude of RBC transfusion. Subanalysis by surgical stage (hepatectomy, anhepatic, neohepatic) and by serial HVPG cut-offs found no clear associations with either bleeding or transfusion. DISCUSSION: The severity of PHT plays a minor role on bleeding and transfusion during LT in a contemporary cohort with systematic PCS. Main determinants of transfusion are liver function and baseline hemoglobin, which would seem the suitable goal to optimize transfusion in LT.

Blood component requirements in liver transplantation: effect of 2 thromboelastometry-guided strategies for bolus fibrinogen infusion-the TROMBOFIB randomized trial.

BACKGROUND: A low plasma fibrinogen level influences blood component transfusion. Thromboelastometry provides clinical guidance for fibrinogen replacement in liver transplantation (LT). OBJECTIVES: We hypothesized that infusions of fibrinogen concentrate to reach an A10FibTem value of 11 mm during LT could reduce red blood cell (RBC) and other component and fluid requirements in comparison to standard care. METHODS: This randomized, blinded, multicenter trial in 3 hospitals enrolled 189 LT-scheduled patients allocated to an intervention target (A10FibTem, 11 mm) or a standard target (A10FibTem, 8 mm); 176 patients underwent LT with fibrinogen replacement. Data were analyzed by intention-to-treat (intervention group, 91; control group, 85). Blood was extracted, and fibrinogen kits were prepared to bring each patient's fibrinogen level to the assigned target at the start of LT, after portal vein clamping, and after graft reperfusion. The main outcome was the proportion of patients requiring RBC transfusion during LT or within 24 hours. RESULTS: The proportion of patients requiring RBCs did not differ between the groups: intervention, 74.7% (95% CI, 65.5%-83.3%); control, 72.9% (95% CI, 62.2%-82.0%); absolute difference, 1.8% (95% CI, -11.1% to 14.78%) (P = .922). Thrombotic events occurred in 4% of the patients in both groups; reoperation and retransplantation rates and mortality did not differ. Nearly 70% of the patients in both groups required fibrinogen concentrate to reach the target. Using an 11-mm A10FibTem target increased the maximum clot firmness without affecting safety. However, this change provided no clinical benefits. CONCLUSION: The similar low plasma fibrinogen concentrations could explain the lack of significant between-group outcomes.

Outcomes after 20 years of experience in minimally invasive living-donor nephrectomy.

INTRODUCTION: The transperitoneal laparoscopic approach is considered the gold standard technique for living kidney donation. Other accepted laparoscopic techniques include the retroperitoneal approach, natural orifice transluminal endoscopic surgery (NOTES)-assisted, laparo-endoscopic single-site surgery (LESS), with excellent results in the donor and graft. Many studies have compared these techniques with open ones. Our objective is to describe our experience and results in minimally invasive living-donor nephrectomies (MILDN): laparoscopic, NOTES-assisted, and LESS since their introduction in March 2002. MATERIALS AND METHODS: We conducted a retrospective observational study of donors undergoing MILDN between March 2002 and March 2020. RESULTS: A total of 714 MILDNs were performed at our centre. All were completed, except for one, because of recipient death. The conventional laparoscopic approach was used in 541 cases (75.88%), NOTES in 116 (16.9%), LESS in 55 (7.7%), and one mini open (0.14%). Two-thirds of the donors were females (478 cases). The mean donor age was 52.87 years (SD 10.93). Six donors (0.8%) were diagnosed beforehand with a small renal mass, which was removed before transplantation in bench surgery. The right kidney was removed in 17.8% of cases. Warm ischaemia time was higher in the NOTES and LESS groups. We had eight conversions. The global intraoperative and postoperative complication rates were 6.8% and 4.9%, respectively. None of the donors developed renal disease during follow-up (mean 3.68 years). Five-year recipient and graft survival rates were 98.8% and 96.8%, respectively. CONCLUSIONS: MILDN techniques are safe for donors and grafts, with low complication.

Is antivitamin K reversal required in patients with cirrhosis undergoing liver transplantation?

BACKGROUND: Antivitamin K agent (AVK) reversal in patients with cirrhosis awaiting liver transplantation (LT) is not defined in guidelines. We investigated the effect of reversion with prothrombin complex concentrate (PCC) on intraoperative transfusion, bleeding, and safety in LT patients on AVK. STUDY DESIGN AND METHODS: In 511 patients undergoing LT, we identified 25 patients treated with AVK (AVK group) and 13 patients with incidental portal vein thrombosis (PVT) without AVK (incidental PVT group). Fifty patients who underwent LT without PVT or AVK matched by age, model for end stage of liver disease (MELD), body mass index (BMI), and cirrhosis etiology were selected as the control group. RESULTS: There were no significant differences between the three groups in intraoperative blood loss, transfusion, and postoperative bleeding. In the AVK group, there were no differences between patients who received PCC and those who did not in intraoperative blood loss, red blood cells, fibrinogen, and platelet transfusion, or postoperative bleeding. PCC use had no effect on RBC transfusion in patients who had international normalized ratio or clotting time above versus below median values of the two parameters at baseline (2.3 and 103 s, respectively). No thrombotic events were detected in patients who received PCC. DISCUSSION: These data suggest that systematic administration of PCC to revert AVK prior to LT should be reconsidered.

Assessment of rotational thromboelastometry for the prediction of red blood cell requirements in orthotopic liver transplantation.

BACKGROUND: In liver transplantation most studies were designed to predict massive transfusion rather than whether or not transfusion is required. We hypothesized that (presurgery) data from thromboelastometry may predict perioperative blood requirements. METHODS: A post-hoc analysis of data from a controlled trial was performed with the primary end point of predicting zero red blood cells. Of the 92 patients studied, 6 were excluded because of incomplete EXTEM and/or FIBTEM data. The multivariate models included preoperative variables with a P value <0.10 in the univariate model: age, MELD score, hemoglobin, plasma fibrinogen, platelet count, activated partial thromboplastin time, INR, EXTEM maximum clot amplitude after 10 minutes, EXTEM an FIBTEM maximum clot firmness, plasma creatinine, and donor data. RESULTS: Blood was transfused to 58% of patients during the surgical procedure and to 34% in the first 24 hours postoperatively. The final model was selected using a backward approach, and fractional polynomials were explored to assess model improvement for the prediction. Hemoglobin was a strong predictor: each 1 g/dL of hemoglobin increase reduced the risk of blood transfusion by 52%. An EXTEM maximum amplitude at 10 min was also a predictor of Red Blood requirement, showing a 64% risk reduction for values between the first quartile (35 mm) and the second quartile (41 mm) but no further improvement for the third and fourth quartiles and resulting in a prediction (ROC AUC of 0.815 [0.771-0.859]). CONCLUSIONS: Presurgical EXTEM maximum amplitude at 10 min <35 mm is highly predictive of red blood administration during liver transplantation.

Venous Thrombotic Events After Liver Transplantation.

Thromboprophylaxis is not well defined after liver transplantation (LT). The aim of this study was to evaluate the incidence of splanchnic vein thrombosis (SVT) and nonsplanchnic vein thrombosis (NSVT) after LT. Liver transplantations performed between 2009 and 2013 in our institution were reviewed. Demographic, intraoperative, and postoperative data were recorded. Low-molecular-weight heparin was only administered postoperatively if intraoperative thrombectomy was performed or in patients preoperatively anticoagulated. Of a total of 328 patients, 72% were male with a median age of 56 years, score of model for end-stage liver disease 18 (11-23), and 88% had liver cirrhosis. The incidence of postoperative venous thrombotic events was 4.6%: 8 (2.4%) patients had SVT and 7 (2.1%) patients had NSVT. After logistic regression analysis, intraoperative thrombectomy and Child A classification emerged as risk factors for SVT (odds ratio [OR]: 77, 95% confidence interval [95% CI]: 14-421) and NSVT (OR: 20, 95% CI: 3-170), respectively. The incidence of SVT in patients who undergo intraoperative thrombectomy was 33%, whereas the incidence of NSVT in patients grouped as Child A was 7.5%. Our results suggest that thromboprophylaxis should be considered after LT in patients with cirrhosis grouped as Child A and in patients who undergo intraoperative thrombectomy.

[Spontaneous perforation of the bile duct in a neonate: An unexpected finding. Case report]. / Perforación espontánea de la vía biliar en un neonato: un hallazgo inesperado. Caso clínico.

Spontaneous extrahepatic bile duct perforation is rare in newborns. It is a surgical cause of jaundice in this period and the acute presentation is unusual. OBJECTIVE: To report a case of spontaneous bile duct perforation in a newborn due to its serious complications if an early and timely diagnosis is not performed. CLINICAL CASE: A 10-day-old newborn who developed food rejection, fever and abdominal distension without jaundice, acolia, or coluria two days prior of admission. The laboratory tests showed leukopenia, thrombocytosis, increased C-reactive protein, and normal hepatic function. The abdominal x-ray showed pneumoperitoneum, and the diagnosis of necrotizing enterocolitis was made. Laparotomy was performed; extrahepatic bile duct perforation and biliary peritonitis were noted. Intraoperative cholangiography demonstrated rescatable proximal bile duct and dilated cystic duct. Hepatic-jejunostomy was performed with Roux-en-Y and cholecystectomy. In the postoperative study portal thrombosis was found, so he received anticoagulant treatment. At 8 months of age, the patient had enteral feeding tolerance and adequate weight gain. CONCLUSIONS: Biliary perforation is a rare entity and more in the neonatal period, a condition that makes it a diagnostic and therapeutic challenge. The prognosis will depend on early intervention and intraoperative findings.

Perforación espontánea de la vía biliar en un neonato: un hallazgo inesperado: caso clínico / Spontaneous perforation of the bile duct in a neonate: an unexpected finding: case report

La perforación espontánea de la vía biliar extrahepática es rara en recién nacidos. Es una causa quirúrgica de ictericia en este período y la presentación aguda es inusual. OBJETIVO: presentar un caso de perforación espontanea de la vía biliar en un recién nacido por sus graves complicaciones si no se realiza un diagnóstico temprano y oportuno. CASO CLÍNICO: Recién nacido de término de 10 días de vida que consultó por cuadro de rechazo alimentario, fiebre y distensión abdominal de 2 días de evolución, sin ictericia, acolia, ni coluria. En los exámenes de laboratorio se encontró leucopenia, trombocitosis y elevación de la proteína C reactiva, con función hepática normal. La radiografía de abdomen demostró neumoperitoneo, sospechándose enterocolitis necrosante, se realizó laparotomía, encontrándose perforación espontánea de la vía biliar extrahepática y peritonitis biliar. La colangiografía intraoperatoria demostró la vía biliar proximal rescatable y conducto cístico dilatado. Se realizó hepático-yeyunostomía con Y de Roux transmesocolónica y colecistectomía. En el estudio postoperatorio se encontró trombosis portal, por lo que recibió tratamiento anticoagulante. En el control a los ocho meses de edad, la paciente tenía buena tolerancia oral y adecuado incremento ponderal. CONCLUSIONES: La perforación biliar es una entidad rara y más en el período neonatal, condición que la vuelve un reto diagnóstico y terapéutico. El pronóstico dependerá de la intervención temprana y los hallazgos intraoperatorios.

Spontaneous extrahepatic bile duct perforation is rare in newborns. It is a surgical cause of jaundice in this period and the acute presentation is unusual. OBJECTIVE: To report a case of spontaneous bile duct perforation in a newborn due to its serious complications if an early and timely diagnosis is not performed. CLINICAL CASE: A 10-day-old newborn who developed food rejection, fever and abdominal distension without jaundice, acolia, or coluria two days prior of admission. The laboratory tests showed leukopenia, thrombocytosis, increased C-reactive protein, and normal hepatic function. The abdominal x-ray showed pneumoperitoneum, and the diagnosis of necrotizing enterocolitis was made. Laparotomy was performed; extrahepatic bile duct perforation and biliary peritonitis were noted. Intraoperative cholangiography demonstrated rescatable proximal bile duct and dilated cystic duct. Hepatic-jejunostomy was performed with Roux-en-Y and cholecystectomy. In the postoperative study portal thrombosis was found, so he received anticoagulant treatment. At 8 months of age, the patient had enteral feeding tolerance and adequate weight gain. CONCLUSIONS: Biliary perforation is a rare entity and more in the neonatal period, a condition that makes it a diagnostic and therapeutic challenge. The prognosis will depend on early intervention and intraoperative findings.

Development of a Pig Model for Laparoscopic Kidney Transplant.

OBJECTIVES: Our aim was to describe a standardized laparoscopic kidney transplant procedure in a pig model. MATERIALS AND METHODS: Ten pigs underwent laparoscopic kidney autotransplant. A right-hand assisted nephrectomy was performed through a Pfannenstiel incision. After the graft was washed with Ringer lactate, it was transplanted into the right iliac vessels by pure laparoscopy. To maintain cold ischemia, a gauze-wrapped ice slush was placed below the allograft. The ureteroneocystostomy was performed through the Pfannenstiel incision. The contralateral ureter was ligated at the end of the procedure. After 24 hours, pigs were killed, and the allograft's perfusion function and presence of urine in the bladder were evaluated. RESULTS: Procedures for 2 animals (20%) could not be completed because of technical problems in the vascular anastomosis; the other 8 procedures (80%) were completed successfully. Seven allografts (87.5%) were functioning 24 hours after surgery, with urine in the bladder and good perfusion of the allograft. The other kidney presented with a venous thrombosis that was detected after death. Mean surgical times were 56.2 ± 11.7 minutes for vein anastomosis and 44.7 ± 23.1 minutes for artery anastomosis. Mean ischemia time was 193 minutes. Total duration of the procedure was clearly decreased in the last 4 animals undergoing transplant. CONCLUSIONS: Laparoscopic transplant is a difficult procedure that requires experience in kidney laparoscopy and laparoscopic vascular sutures. The experimental model presented is a good training option and can be used to evaluate different methods to maintain cold ischemia and to compare with the traditional open approach.

Reliability of thromboelastometry for detecting the safe coagulation threshold in patients taking acenocoumarol after elective heart valve replacement.

BACKGROUND: Reversal of anticoagulation can be needed in patients undergoing heart valve surgery. ROTEM® has been correlated with international normalized ratio (INR) in patients on warfarin but not with patients on acenocoumarol. This study investigates the reliability of ROTEM® for detecting INR values below the 1.5 threshold in patients on acenocoumarol therapy. MATERIAL AND METHODS: Patients on oral anticoagulation with acenocoumarol after elective heart valve replacement were prospectively included in the study. INR and the ROTEM® were measured simultaneously. ROTEM® parameters included coagulation time, clot formation time, alpha angle, and maximal clot firmness after tissue factor activation (EXTEM). Concordance between INR and ROTEM® was analyzed by Lin's concordance coefficient (LCC) and the correlation with Spearman's rho. RESULTS: Fifty-four consecutive patients (40 female; median age 67years) were included. Clotting time (CT) was the parameter that best correlated with INR (r=0.81, p<0,001), and LCC was substantial (0.67). CT was able to predict INR values above or below 1.5: area under curve=0.998. CT≥84seconds, corresponding to a cut-off for likelihood ratio (LR+)=5, had a sensitivity and specificity of 100% and 80%, respectively, to detect an INR below 1.5. For the same INR threshold, CT≥84seconds had a predictive positive value of 92.9% and a predictive negative value of 100%. CONCLUSION: Our preliminary results suggest that CT≥84seconds in the EXTEM ROTEM® test is a feasible method for predicting an insufficient reversion of oral anticoagulant therapy in patients taking acenocoumarol after elective heart valve surgery.

Transient hyperglycemia during liver transplantation does not affect the early graft function.

UNLABELLED: Background and rationale for the study. Hyperglycemia after graft reperfusion is a consistent finding in liver transplantation (LT) that remains poorly studied. We aim to describe its appearance in LT recipients of different types of grafts and its relation to the graft function. MATERIAL & METHODS: 436 LT recipients of donors after brain death (DBD), donors after cardiac death (DCD), and familial amyloidotic polyneuropathy (FAP) donors were reviewed. Serum glucose was measured at baseline, during the anhepatic phase, after graft reperfusion, and at the end of surgery. Early graft dysfunction (EAD) was assessed by Olthoff criteria. Caspase-3, IFN-γ, IL1ß, and IL6 gene expression were measured in liver biopsy. RESULTS: The highest increase in glucose levels after reperfusion was observed in FAP LT recipients and the lowest in DCD LT recipients. Glucose level during the anhepatic phase was the only modifiable predictive variable of hyperglycemia after reperfusion. No relation was found between hyperglycemia after reperfusion and EAD. However, recipients with the highest glucose levels after reperfusion tended to achieve the best glucose control at the end of surgery and those who were unable to control the glucose value after reperfusion showed EAD more frequently. The highest levels of caspase-3 were found in recipients with the lowest glucose values after reperfusion. In conclusion, glucose levels increased after graft reperfusion to a different extent according to the donor type. Contrary to general belief, transient hyperglycemia after reperfusion does not appear to impact negatively on the liver graft function and could even be suggested as a marker of graft quality.

Inertial sensor self-calibration in a visually-aided navigation approach for a micro-AUV.

This paper presents a new solution for underwater observation, image recording, mapping and 3D reconstruction in shallow waters. The platform, designed as a research and testing tool, is based on a small underwater robot equipped with a MEMS-based IMU, two stereo cameras and a pressure sensor. The data given by the sensors are fused, adjusted and corrected in a multiplicative error state Kalman filter (MESKF), which returns a single vector with the pose and twist of the vehicle and the biases of the inertial sensors (the accelerometer and the gyroscope). The inclusion of these biases in the state vector permits their self-calibration and stabilization, improving the estimates of the robot orientation. Experiments in controlled underwater scenarios and in the sea have demonstrated a satisfactory performance and the capacity of the vehicle to operate in real environments and in real time.

Immune and stress mediators in response to bilateral adnexectomy: comparison of single-port access and conventional laparoscopy in a porcine model.

STUDY OBJECTIVE: To evaluate systemic markers of immune and stress responses after bilateral adnexectomy performed using 2 different laparoscopic techniques in pigs. DESIGN: Prospective comparative study (Canadian Task Force classification II-2). SETTING: University teaching hospital, research hospital, and tertiary care center. ANIMALS: Twenty female Yorkshire pigs undergoing laparoscopic surgery. INTERVENTIONS: Animals underwent bilateral salpingo-oophorectomy (ovary and fallopian tube extraction), performed via conventional laparoscopy (n = 10) or the single-port access approach (n = 10). MEASUREMENTS AND MAIN RESULTS: Injury provokes an acute-phase response, primarily produced by cytokines. The inflammatory response has been well described for major surgery and for conventional laparoscopy; however, little information is currently available for single-port laparoscopy, and none in the gynecologic field. This is the first study to compare serum cytokine interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) concentrations at baseline and in the early postoperative period (2, 4, and 20 hours) after bilateral salpingo-oophorectomy performed via conventional laparoscopy (n = 10) or single-port access (n = 10) in a porcine model. The stress response was measured using glucose and cortisol concentrations and the animals' response to surgery via a 6-category observation-based behavior test. Both IL-6 and TNF-α concentrations peaked at 4 hours after surgery, and were significantly lower in the single-port access group (p = .02) than in the conventional laparoscopy group (p = .02). In addition, in the single-port access group, concentrations of stress markers were slightly lower at all intervals recorded and were statistically significant at 2 hours after the operation for glucose concentration (mean [SD], 164.50 [26.73] mg/dL for conventional laparoscopy vs 86.50 [17.93] mg/dL for single-port access; p = .02). CONCLUSION: Evidence of improved inflammatory and stress responses was recorded in the minimally invasive single-port group. More clinical investigations are needed to further study the applicability of single-port access laparoscopy in gynecologic surgery.

Stroke volume response to liver graft reperfusion stress in cirrhotic patients.

INTRODUCTION: In patients with advanced cirrhosis, stressful stimuli may reveal a silent reduced cardiac performance. During liver transplantation (LT), graft reperfusion strongly stresses the heart and may unmask latent myocardial dysfunction. AIM: The objective of this study was to assess heart response to acutely increased preload after liver graft reperfusion and correlate this response with preoperative data and outcome. METHODS: Preoperative clinical, echocardiographic, and hemodynamic data, and patient outcome were retrospectively recorded for 235 liver recipients who had no known cardiac disease. Myocardial dysfunction was defined as less than 10 % increase of stroke volume after graft reperfusion (non-responder). RESULTS: We found 84 (35.7 %) non-responder patients. The non-responders showed higher Model for end-stage liver disease scores (p = 0.046), left atrial diameter (LAD) (p = 0.040), hepatic vein pressure gradient (p = 0.055), and hyperdynamic state than responders. The percentages of patients with hyponatremia (p = 0.048) and alcohol etiology (p = 0.025) were also higher among non-responders. Independent predictors of inadequate cardiac response in the multivariate analysis were low preoperative systemic vascular resistance (SVRI) [odds ratio (OR) 3.09, 95 % CI 1.15-4.82; p = 0.027] and enlargement of LAD (OR 2.08, 95 % CI 1.49-2.74; p = 0.044). Non-response was associated with higher rates of early cardiovascular events [hazard ratio (HR) 2.84, 95 % CI 1.09-4.22; p = 0.039] and higher length of intensive care unit stay (p = 0.038). No differences were found in 1-year survival rates. CONCLUSIONS: Latent cardiac dysfunction among LT recipients, considered to be abnormal stroke volume response to unclamping of portal vein, is very prevalent. SVRI and LAD were independent predictors of inadequate responses. This condition deserves special attention since it may aggravate the early postoperative course of LT.

Impact of experimental haemodilution on platelet function, thrombin generation and clot firmness: effects of different coagulation factor concentrates.

BACKGROUND: Haemodilution during resuscitation after massive haemorrhage may worsen the coagulopathy and perpetuate bleeding. MATERIALS AND METHODS: Blood samples from healthy donors were diluted (30 and-60%) using crystalloids (saline, Ringer's lactate, Plasmalyte(TM)) or colloids (6% hydroxyethylstarch [HES130/0.4], 5% human albumin, and gelatin). The effects of haemodilution on platelet adhesion (Impact R), thrombin generation (TG), and thromboelastometry (TEM) parameters were analysed as were the effects of fibrinogen, prothrombin complex concentrates (PCC), activated recombinant factor VII (FVIIa), and cryoprecipates on haemodilution. RESULTS: Platelet interactions was already significantly reduced at 30% haemodilution. Platelet reactivity was not improved by addition of any of the concentrates tested. A decrease in TG and marked alterations of TEM parameters were noted at 60% haemodilution. HES130/0.4 was the expander with the most deleterious action. TG was significantly enhanced by PCC whereas rFVIIa only caused a mild acceleration of TG initiation. Fibrinogen restored the alterations of TEM parameters caused by haemodilution including those caused by HES 130/0.4. Cryoprecipitates significantly improved the alterations caused by haemodilution on TG and TEM parameters; the effects on TG disappeared after ultracentrifugation of the cryoprecipitates. DISCUSSION: The haemostatic alterations caused by haemodilution are multifactorial and affect both blood cells and coagulation. In our in vitro approach, HES 130/0.4 had the most deleterious effect on haemostasis parameters. Coagulation factor concentrates did not improve platelet interactions in the Impact R, but did have favourable effects on coagulation parameters measured by TG and TEM. Fibrinogen notably improved TEM parameters without increasing thrombin generation, suggesting that this concentrate may help to preserve blood clotting abilities during haemodilution without enhancing the prothrombotic risk.