Postreperfusion Syndrome in Patients Receiving Vasoactive Drugs During Liver Graft Reperfusion.

OBJECTIVES: The most widely used definition of postreperfusion syndrome in liver transplant is a 30% decrease in mean arterial pressure during the first 5 minutes after vascular unclamping. With these criteria, increased postoperative morbidity has been reported. Vasoactivedrugs couldpreventthis syndrome.Themain objective of our study was to determine the incidence and complications associated with postreperfusion syndrome inpatientswho receivedvasoactive support. MATERIALS AND METHODS: We studied 246 patients who received norepinephrine infusions to maintain mean arterial pressure ≥60 mm Hg and who were monitored with a Swan-Ganz catheter. Patients received a bolus of adrenaline after vascular unclamping in cases of insufficient response to norepinephrine. RESULTS: Among the study patients, 57 (23.17%) developed postreperfusion syndrome. Patients who developed postreperfusion syndrome did not present with morepostoperative complications interms ofrenal dysfunction (P = .69), repeat surgery (P = .15), graft rejection (P = .69), transplant replacement surgery (P = .76), hospital stay (P = .70), or survival (P = .17) compared with patients without postreperfusion syndrome. CONCLUSIONS: In patients who underwent orthotopic liver transplant, in whom vasoactive drugs were administered, a diagnosis of self-limited postreperfusion syndrome during the first 5 minutes after unclamping may not be associated with postoperative complications. The administration of vasoconstrictors may have a preventive effect on the postoperative complications associated with postreperfusion syndrome or they may mask the real incidence of postreperfusion syndrome. A broader definition of postreperfusion syndrome should be accepted.

Intraoperative Neurophysiological Monitoring in Syringomyelia Surgery: A Multimodal Approach.

Syringomyelia can be associated with multiple etiologies. The treatment of the underlying causes is first-line therapy; however, a direct approach to the syrinx is accepted as rescue treatment. Any direct intervention on the syrinx requires a myelotomy, posing a significant risk of iatrogenic spinal cord (SC) injury. Intraoperative neurophysiological monitoring (IONM) is crucial to detect and prevent surgically induced damage in neural SC pathways. We retrospectively reviewed the perioperative and intraoperative neurophysiological data and perioperative neurological examinations in ten cases of syringomyelia surgery. All the monitored modalities remained stable throughout the surgery in six cases, correlating with no new postoperative neurological deficits. In two patients, significant transitory attenuation, or loss of motor evoked potentials (MEPs), were observed and recovered after a corrective surgical maneuver, with no new postoperative deficits. In two cases, a significant MEP decrement was noted, which lasted until the end of the surgery and was associated with postoperative weakness. A transitory train of neurotonic electromyography (EMG) discharges was reported in one case. The surgical plan was adjusted, and the patient showed no postoperative deficits. The dorsal nerve roots were stimulated and identified in the seven cases where the myelotomy was performed via the dorsal root entry zone. Dorsal column mapping guided the myelotomy entry zone in four of the cases. In conclusion, multimodal IONM is feasible and reliable and may help prevent iatrogenic SC injury during syringomyelia surgery.

Metabolism changes during direct revascularization in moyamoya disease: illustrative case.

BACKGROUND: Cerebral revascularization is recommended for patients with moyamoya disease (MMD) with reduced cerebral perfusion reserve and recurrent or progressive ischemic events. The standard surgical treatment for these patients is a low-flow bypass with or without indirect revascularization. The use of intraoperative monitoring of the metabolic profile using analytes such as glucose, lactate, pyruvate, and glycerol has not yet been described during cerebral artery bypass surgery for MMD-induced chronic cerebral ischemia. The authors aimed to describe an illustrative case using intraoperative microdialysis and brain tissue oxygen partial pressure (PbtO2) probes in a patient with MMD during direct revascularization. OBSERVATIONS: The patient's severe tissue hypoxia situation was confirmed by a PbtO2:partial pressure of oxygen (PaO2) ratio below 0.1 and anaerobic metabolism by a lactate:pyruvate ratio greater than 40. Following bypass, a rapid and sustained increase in PbtO2 up to normal values (PbtO2:PaO2 ratio between 0.1 and 0.35) and the normalization of cerebral energetic metabolism with a lactate/pyruvate ratio less than 20 was observed. LESSONS: The results show a quick improvement of regional cerebral hemodynamics due to the direct anastomosis procedure, reducing the incidence of subsequent ischemic stroke in pediatric and adult patients immediately.

Liver transplant with controlled donors after circulatory death with normothermic regional perfusion and brain dead donors: A multicenter cohort study of transfusion, one-year graft survival and mortality.

BACKGROUND: Controlled donation after circulatory death (cDCD) has expanded the donor pool for liver transplantation (LT). However, transfusion requirements and perioperative outcomes should be elucidated. The aim of this multicenter study was to assess red blood cell (RBC) transfusions, one-year graft and patient survival after LT after cDCD with normothermic regional perfusion (NRP) compared with donors after brain death (DBD). METHODS: 591 LT carried out in ten centers during 2019 were reviewed. Thromboelastometry was used to manage coagulation and blood product transfusion in all centers. Normothermic regional perfusion was the standard technique for organ recovery. RESULTS: 447 patients received DBD and 144 cDCD with NRP. Baseline MCF Extem was lower in the cDCD group There were no differences in the percentage of patients (63% vs. 61% p = 0.69), nor in the number of RBC units transfused (4.7 (0.2) vs 5.5 (0.4) in DBD vs cDCD, p = 0.11. Twenty-six patients (6%) died during admission for LT in the DBD group compared with 3 patients (2%) in the cDCD group (p = 0.15). To overcome the bias due to a worse coagulation profile in cDCD recipients, matched samples were compared. No differences in baseline laboratory data, or in intraoperative use of RBC or one-year outcome data were observed between DBD and cDCD recipients. CONCLUSIONS: cDCD with NRP is not associated with increased RBC transfusion. No differences in graft and patient survival between cDCD and DBD were found. Donors after controlled circulatory death with NRP can increasingly be utilized with safety, improving the imbalance between organ donors and the ever-growing demand.

Baseline haemoglobin and thromboelastometry are predictive of red blood cell requirements and one-year mortality in liver transplantation.

BACKGROUND: To determine the predictive capacity of baseline haemoglobin and maxim clot firmness (MCF) EXTEM thromboelastometry for intraoperative red blood cell (RBC) requirements and its influence on mortality. METHODS: 591 adult liver transplant (LT) recipients from ten Spanish centres were reviewed. The main outcomes were the percentage of patients who received RBC and massive transfusion (≥ 6 RBC units), RBC units transfused, and mortality. RESULTS: 76 % received a donor after brain death graft and 24 % a controlled donor after circulatory death graft. Median (interquartile ranges) RBC transfusion was 2 (0-4) units, and 63 % of patients were transfused. Comparing transfused and non-transfused patients, mean (standard deviation) for baseline haemoglobin was 10.4 (2.1) vs. 13.0 (1.9) g/dl (p = 0.001), EXTEM MCF was 51(11) vs. 55(9) mm (p = 0.001). Haemoglobin and EXTEM MCF were inversely associated with the need of transfusion odds ratio (OR) of 0.558 (95 % CI 0.497-0.627, p < 0.001) and OR 0.966 (95 % CI0.945-0.987, p = 0.002), respectively. Pre-operative baseline haemoglobin ≤ 10 g/dL predicted RBC transfusion, sensitivity of 93 % and specificity of 47 %. Massive transfusion (MT) was received by 19 % of patients. Haemoglobin ≤10 g/dL predicted MT with sensitivity 73 % and specificity of 52 %. One-year patient and graft survival were significantly lower in patients who required MT (78 % and 76 %, respectively) vs. those who did not (94 % and 93 %, respectively). DISCUSSION: whereas EXTEM MCF is less dreterminant predicting RBC requirements, efforts are required to improve preoperative haemoglobin up to 10 g/dl in patients awaiting LT.

Experiencia y resultados de las técnicas de revascularización en patología cerebral isquémica: enfermedad de moyamoya y oclusión carotídea / Revascularization experience and results in ischaemic cerebrovascular disease: Moyamoya disease and carotid occlusion

Introducción: Las técnicas de revascularización cerebral constituyen una herramienta indispensable en el arsenal actual del neurocirujano vascular. Presentamos la experiencia adquirida y los resultados de la cirugía de revascularización tanto en la enfermedad de moyamoya como en la isquemia cerebral oclusiva. Pacientes y métodos: Se analizan los pacientes con enfermedad isquémica oclusiva y enfermedad de moyamoya revascularizados microquirúrgicamente en el periodo comprendido entre octubre de 2014 y septiembre de 2017. Resultados: En el periodo de estudio, 23 pacientes con enfermedad isquémica oclusiva han sido revascularizados microquirúrgicamente. Tres pacientes presentaron complicaciones postoperatorias graves (2 hemorragias intraparenquimatosas en el postoperatorio inmediato y una trombosis de la arteria femoral). En todos los pacientes, excepto en uno, el SPECT muestra una normalización de la reserva hemodinámica cerebral (RHC). Veinte pacientes presentaron un buen resultado neurológico, sin recurrencias isquémicas del territorio revascularizado. De la serie de pacientes con moyamoya, 20 presentaban una enfermedad de moyamoya y 5 un síndrome de moyamoya con afectación unilateral. Cinco pacientes fueron tratados en edad pediátrica. Hubo un comienzo hemorrágico en 2 pacientes. El estudio de la RHC mostró un compromiso hemodinámico en todos los pacientes. El SPECT cerebral al año ha mostrado una resolución del fracaso hemodinámico en todos los pacientes. Ha habido 4 complicaciones postoperatorias (hematoma subdural agudo, 2 colecciones subdurales y una dehiscencia de la herida quirúrgica). Ningún paciente ha presentado un empeoramiento neurológico en los controles a los 6 y 12meses. Conclusión: La revascularización cerebral mediante la realización de una anastomosis termino-lateral entre la arteria temporal superficial y una rama cortical de la arteria cerebral media constituye una técnica indiscutible en el tratamiento de la enfermedad de moyamoya y posiblemente pueda serlo en un subgrupo de pacientes con patología oclusiva isquémica cerebral sintomática

Introduction: Cerebral revascularization techniques are an indispensable tool in the current armamentarium of vascular neurosurgeons. We present revascularization surgery experience and results in both moyamoya disease and occlusive cerebral ischaemia. Patients and methods: Patients with ischaemic occlusive disease and moyamoya disease who underwent microsurgical revascularization between October 2014 and September 2017 were analysed. Results: In the study period, 23 patients with occlusive ischaemic disease underwent microsurgical revascularization. Three patients presented with serious postoperative complications (2 intraparenchymal haemorrhages in the immediate postoperative period and one thrombosis of the femoral artery). All patients, except one, achieved normalization of the cerebral hemodynamic reserve (CHR) in the SPECT study. Twenty patients had a good neurological result, with no ischaemic recurrence of the revascularized territory. Among patients with moyamoya, 20 had moyamoya disease and 5 had moyamoya syndrome with unilateral involvement. Five patients were treated at paediatric age. Haemorrhagic onset occurred in 2 patients. The CHR study showed hemodynamic compromise in all patients. Cerebral SPECT at one year showed resolution of the hemodynamic failure in all patients. There have been 4 postoperative complications (acute subdural hematoma, two subdural collections and one dehiscence of the surgical wound). No patient presented with neurological worsening at 6 and 12months of follow-up. Conclusions: Cerebral revascularization through end-to-side anastomosis between the superficial temporal artery and a cortical branch of the middle cerebral artery is an indisputable technique in the treatment of moyamoya disease and possibly in a subgroup of patients with symptomatic occlusive ischaemic cerebrovascular disease

[Revascularization experience and results in ischaemic cerebrovascular disease: Moyamoya disease and carotid occlusion]. / Experiencia y resultados de las técnicas de revascularización en patología cerebral isquémica: enfermedad de moyamoya y oclusión carotídea.

INTRODUCTION: Cerebral revascularization techniques are an indispensable tool in the current armamentarium of vascular neurosurgeons. We present revascularization surgery experience and results in both moyamoya disease and occlusive cerebral ischaemia. PATIENTS AND METHODS: Patients with ischaemic occlusive disease and moyamoya disease who underwent microsurgical revascularization between October 2014 and September 2017 were analysed. RESULTS: In the study period, 23 patients with occlusive ischaemic disease underwent microsurgical revascularization. Three patients presented with serious postoperative complications (2 intraparenchymal haemorrhages in the immediate postoperative period and one thrombosis of the femoral artery). All patients, except one, achieved normalization of the cerebral hemodynamic reserve (CHR) in the SPECT study. Twenty patients had a good neurological result, with no ischaemic recurrence of the revascularized territory. Among patients with moyamoya, 20 had moyamoya disease and 5 had moyamoya syndrome with unilateral involvement. Five patients were treated at paediatric age. Haemorrhagic onset occurred in 2 patients. The CHR study showed hemodynamic compromise in all patients. Cerebral SPECT at one year showed resolution of the hemodynamic failure in all patients. There have been 4 postoperative complications (acute subdural hematoma, two subdural collections and one dehiscence of the surgical wound). No patient presented with neurological worsening at 6 and 12months of follow-up. CONCLUSIONS: Cerebral revascularization through end-to-side anastomosis between the superficial temporal artery and a cortical branch of the middle cerebral artery is an indisputable technique in the treatment of moyamoya disease and possibly in a subgroup of patients with symptomatic occlusive ischaemic cerebrovascular disease.

Reappraisal of the reference levels for energy metabolites in the extracellular fluid of the human brain.

Cerebral microdialysis is widely used in neurocritical care units. The goal of this study was to establish the reference interval for the interstitial fluid concentrations of energy metabolites and glycerol by using the extrapolation to zero-flow methodology in anesthetized patients and by constant perfusion at 0.3 µL/min in awake patients. A CMA-71 probe was implanted during surgery in normal white matter of patients with posterior fossa or supratentorial lesions, and the perfusion flow rate was randomized to 0.1, 0.3, 0.6, 1.2, and 2.4 µL/min. Within 24 h of surgery, perfusion was restarted at a constant 0.3 µL/min in fully awake patients. The actual interstitial fluid metabolite concentrations were calculated using the zero-flow methodology. In vitro experiments were also conducted to evaluate the reproducibility of the in vivo methodology. Nineteen patients (seven males) with a median age of 44 years (range: 21-69) were included in the in vivo study. The median (lower-upper) reference interval values were 1.57 (1.15-4.13 mmol/L) for glucose, 2.01 (1.30-5.31 mmol/L) for lactate, 80.0 (54.4-197.0 µmol/L) for pyruvate, and 49.9 (23.6-227.3 µmol/L) for glycerol. The reference intervals reported raises the need to reconsider traditional definitions of brain metabolic disturbances and emphasize the importance of using different thresholds for awake patients and patients under anesthesia.

Monitorización intraoperatoria de la presión tisular de oxígeno: aplicaciones en neurocirugía vascular / Intraoperative monitoring of oxygen tissue pressure: Applications in vascular neurosurgery

Las lesiones isquémicas relacionadas con los procedimientos quirúrgicos son una de las principales causas de morbilidad en el postoperatorio de la cirugía de los pacientes con patología vascular cerebral. Con el objetivo de detectar intraoperatoriamente los fenómenos isquémicos se han implementado diferentes sistemas de neuromonitorización, entre los que se encuentra la monitorización de la presión tisular de oxígeno (PtiO2). En este trabajo se pretende describir la utilidad de la monitorización intraoperatoria de la PtiO2 en la neurocirugía vascular a partir de la discusión de 4 casos ejemplo. A partir de la presentación de estos casos se discute cómo este tipo de monitorización permite detectar de una forma precoz y fiable las situaciones relacionadas con el procedimiento quirúrgico que ocasionan una hipoxia cerebral isquémica. La monitorización continua de la PtiO2 en el área de riesgo permite además resolver la causa que ha originado los episodios isquémicos y su evolución a un infarto establecido

Ischemic lesions related to surgical procedures are a major cause of postoperative morbidity in patients with cerebral vascular disease. There are different systems of neuromonitoring to detect intraoperative ischemic events, including intraoperative monitoring of oxygen tissue pressure (PtiO2). The aim of this article was to describe, through the discussion of 4 cases, the usefulness of intraoperative PtiO2 monitoring during vascular neurosurgery. In presenting these cases, we demonstrate that monitoring PtiO2 is a reliable way to detect early ischemic events during surgical procedures. Continuous monitoring of PtiO2 in an area at risk allows the surgeon to resolve the cause of the ischemic event before it evolves to an established cerebral infarction

[Intraoperative monitoring of oxygen tissue pressure: Applications in vascular neurosurgery]. / Monitorización intraoperatoria de la presión tisular de oxígeno: aplicaciones en neurocirugía vascular.

Ischemic lesions related to surgical procedures are a major cause of postoperative morbidity in patients with cerebral vascular disease. There are different systems of neuromonitoring to detect intraoperative ischemic events, including intraoperative monitoring of oxygen tissue pressure (PtiO2). The aim of this article was to describe, through the discussion of 4 cases, the usefulness of intraoperative PtiO2 monitoring during vascular neurosurgery. In presenting these cases, we demonstrate that monitoring PtiO2 is a reliable way to detect early ischemic events during surgical procedures. Continuous monitoring of PtiO2 in an area at risk allows the surgeon to resolve the cause of the ischemic event before it evolves to an established cerebral infarction.