Koen Reyntjens

This study aims to evaluate the pressure characteristics of a new patient warming device (Kanmed Warmcloud®, Kanmed AB, Sweden), consisting of a warm air flow generator connected to an inflatable, disposable air mattress that is positioned underneath the patient. Besides ...

Selective portal vein embolization (PVE) before extended liver surgery is an accepted method to stimulate growth of the future liver remnant. Portal vein thrombosis (PVT) of the main stem and the non-targeted branches to the future liver remnant is a rare but major complication of PVE, requiring immediate revascularization. Without revascularization, curative liver surgery is not possible, resulting in a potentially life-threatening situation. We here present a new surgical technique to revascularize the portal vein after PVT by combining a surgical thrombectomy with catheter-based thrombolysis via the surgically reopened umbilical vein. This technique was successfully applied in a patient who developed thrombosis of the portal vein main stem, as well as the left portal vein and its branches to the left lateral segments after selective right-sided PVE in preparation for an extended right hemihepatectomy. The advantage of this technique is the avoidance of an exploration of hepatoduo...

BACKGROUND The specific effect of donation after circulatory death (DCD) liver grafts on fibrinolysis, blood loss, and transfusion requirements after graft reperfusion is not well known. The aim of this study was to determine whether transplantation of controlled DCD livers is associated with an elevated risk of hyper-fibrinolysis, increased blood loss and higher transfusion requirements upon graft reperfusion, compared to livers donated after brain death (DBD). METHODS A retrospective single-center analysis of all adult recipients of a primary liver transplantation between 2000 and 2019 was performed (total cohort n= 628). Propensity score matching (PSM) was used to balance baseline characteristics for DCD and DBD liver recipients (PSM cohort n= 218). Intra- and postoperative hemostatic variables between DCD and DBD liver recipients were subsequently compared. Additionally, in vitro plasma analyses were performed to compare the intraoperative fibrinolytic state upon reperfusion. RESULTS No significant differences in median (interquartile range) postreperfusion blood loss (1.2 L [0.5-2.2] vs 1.3 L (0.6-2.2); P= 0.62), RBC transfusion (2 units [0-4) vs 1.1 units [0-3], P= 0.21), or FFP transfusion requirements (0 units [0-2.2] vs 0 units (0-0.9); P= 0.11) were seen in DCD compared to DBD recipients, respectively. Furthermore, plasma fibrinolytic potential was similar in both groups. CONCLUSIONS Transplantation of controlled DCD liver grafts does not result in higher intraoperative blood loss or more transfusion requirements, compared to DBD liver transplantation. In accordance to this, no evidence for increased hyper-fibrinolysis upon reperfusion in DCD compared to DBD liver grafts, was found.

Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Dexmedetomidine is a sedative with modest analgesic efficacy, whereas remifentanil is an opioid analgesic with modest sedative potency. Synergy is often observed when sedative–hypnotics are combined with opioid analgesics in anesthetic practice. A three-phase crossover trial was conducted to study the pharmacodynamic interaction between remifentanil and dexmedetomidine. Methods After institutional review board approval, 30 age- and sex- stratified healthy volunteers were studied. The subjects received consecutive stepwise increasing target-controlled infusions of dexmedetomidine, remifentanil, and remifentanil with a fixed dexmedetomidine background concentration. Drug effects were measured using binary (yes or no) endpoints: no response to calling the subject by name, tolerance of shaking the patient while shouting the name (“shake and shout”), tolerance of deep trapezius sq...

Acute kidney injury is associated with high mortality in the perioperative period of liver transplantation. The aim of this position paper was to provide an up-to-date overview with special emphases on diagnosis, risk factors, and treatment. The Liver Intensive Care Group of Europe nominated a panel of recognized international experts who reviewed the available literature published from 1990 to January 2016 and produced clinical recommendations. The level of evidence and strength of recommendation were judged according to the Grading of Recommendations Assessment Development and Evaluation system. Diagnosis of AKI should be based on the KDIGO criteria. The preoperative risk factors are more related to the patient's predisposing factors and post-operative risk factors tend to be difficult to control. Therefore, focusing on intra-operative risk factors it would be important to maintain an adequate hemodynamics and to keep inferior vena cava clamping as short as possible. Biomarker...

The liver transplantation program of the University Medical Center Groningen in the Netherlands was started in 1979, making it one of the first programs worldwide. During the past 36 years, a total of 1478 liver transplantations have been performed, 459 of which were in children. One of the first patients transplanted in 1979 is still alive and is one of the longest surviving patients after liver transplantation worldwide. During the last decade, an increasing number of donation after circulatory death (DCD) donor livers have been accepted for transplantation. Over 30% of the livers transplanted in Groningen come from DCD donors. These livers have an increased risk of developing biliary complications, such as non-anastomotic biliary strictures (NAS). One of the main research topics in Groningen has been the pathogenesis and prevention of NAS. In an attempt to reduce the incidence of NAS after liver transplantation, machine perfusion technology has been developed as an alternative to...

The efficiency of two types of steroid treatment was assessed in primary intracerebral haemorrhages. No significant difference in clinical evolution was observed between 57 cases treated with dexamethasone, 28 cases with methylprednisolone and 44 cases without corticosteroids. In a subgroup of 46 patients with putamino-capsular bleedings the non-steroid-treated group did significantly better than the steroid-treated one. Adverse reactions occurred at the same rate in the three groups.

Several pharmacokinetic models are available for dexmedetomidine, but these have been shown to underestimate plasma concentrations. Most were developed with data from patients during the postoperative phase and/or in intensive care, making them susceptible to errors due to drug interactions. The aim of this study is to improve on existing models using data from healthy volunteers. After local ethics committee approval, the authors recruited 18 volunteers, who received a dexmedetomidine target-controlled infusion with increasing target concentrations: 1, 2, 3, 4, 6, and 8 ng/ml, repeated in two sessions, at least 1 week apart. Each level was maintained for 30 min. If one of the predefined safety criteria was breached, the infusion was terminated and the recovery period began. Arterial blood samples were collected at preset times, and NONMEM (Icon plc, Ireland) was used for model development. The age, weight, and body mass index ranges of the 18 volunteers (9 male and 9 female) were 2...

Perioperative hypothermia is a common complication during general anesthesia. Although rewarming of patients before surgery has been used as a preventive measure and some guidelines recommend it, the implementation of prewarming for every surgical patient is cumbersome. Therefore, we sought to determine the efficacy of two novel prewarming methods that could facilitate prewarming in daily practice. This was a prospective, randomized, multi-center, controlled study. After IRB approval and informed consent, 90 patients undergoing surgery of 30-120 min duration with general anesthesia were randomly assigned to three groups: 1) standard preoperative insulation (Group A); 2) passive preoperative insulation with a commercial prewarming suit (Group B); 3) active preoperative prewarming with a forced-air warmer connected to a prewarming suit (Group C). All patients received warmed IV fluids and intraoperative forced air warming after induction of anesthesia. Oral temperatures were recorded ...

Portopulmonary hypertension (POPH), a complication of chronic liver disease, may be a contraindication to liver transplantation (LT) because of the elevated risk of peritransplant and posttransplant morbidity and mortality. Because POPH is frequently asymptomatic, screening with echocardiography is recommended. The only reliable technique, however, for diagnosing POPH is right heart catheterization (RHC). The aims of this study were to evaluate the current estimated systolic pulmonary artery pressure (sPAP) cutoff value of 30 mm Hg and to determine a better cutoff value. One hundred fifty-two patients underwent pretransplant echocardiography between January 2005 and December 2010. These echocardiographic results were compared with pulmonary artery pressures measured during the pretransplant workup or at the beginning of the transplantation procedure (both by catheterization). With a cutoff value of 30 mm Hg, 74 of the 152 patients met the criteria for POPH on echocardiography, although the diagnosis was confirmed in only 7 patients during catheterization; this resulted in a specificity of 54%. It would have been more accurate to use a cutoff value of 38 mm Hg, which had a maximal specificity of 82% and, at the same time, guaranteed a sensitivity and negative predictive value of 100%. With the incorporation of the presence or absence of right ventricular dilatation, the specificity even increased to 93% for this new cutoff value. In conclusion, the prevalence of POPH was 4.6% among LT candidates in this study. We can recommend that LT candidates with an sPAP > 38 mm Hg should be referred for RHC. With the cutoff value increased from 30 to 38 mm Hg, the number of patients undergoing invasive RHC during their evaluation could be safely reduced.

Portopulmonary hypertension (POPH) is a part of group 1 pulmonary hypertension (pulmonary hypertension associated with portal hypertension). Liver transplantation (LTx) may be curative, but is usually restricted to patients with mild-to-moderate POPH. The presence of severe POPH may be a contraindication to transplantation because of the elevated risk of peritransplantation and post-transplantation morbidity and mortality. This report describes a series of seven patients with onset of moderate (two patients) or severe (five patients) POPH before LTx, of whom six were treated with oral vasodilator therapy for POPH. Although previous studies recommend aggressive parenteral prostacyclin therapy (epoprostenol), we describe the opportunity to treat cases of severe POPH with an oral phosphodiesterase type 5 inhibitor (sildenafil) and/or an endothelin receptor antagonist (bosentan/ambrisentan) as a bridge to successful LTx in selected patients.

Continuous administration of inhaled nitric oxide is now widely used as a potent and selective pulmonary vasodilator. We have evaluated the effects of IV dipyridamole, a cyclic guanosine monophosphate (cGMP) phosphodiesterase inhibitor, on the magnitude and duration of action of inhaled nitric oxide (NO)-mediated pulmonary vasodilation. We hypothesized that inhibition of cGMP degradation could augment and prolong the pulmonary vasodilating effects of NO and allow for intermittent NO inhalation. In eight anesthetized and mechanically ventilated piglets, IV U-46619, a thromboxane A(2) analog, was used to induce pulmonary hypertension. The effects of 2, 5, and 10 ppm of NO, delivered during 4 min for each concentration and followed by a 10-min NO-free interval after each NO concentration, were evaluated without and with dipyridamole. Pulmonary vascular resistance decreased from 825 +/- 49 dynes. s. cm(-5) (U-46619) to 533 +/- 48 dynes. s. cm(-5) (10 ppm NO) (P < 0.05 versus U-46619) and 396 +/- 42 dynes. s. cm(-5) (dipyridamole 10 microg kg-1x min-1 and 10 ppm NO) (P <0.05 versus NO), and cardiac output increased from 1.93 +/- 0.09 L/min to 2.03 +/- 0.13 L/min and 2.60 +/- 0.30 L/min (P < 0.05 versus NO). Mean arterial blood pressure decreased from 90 +/- 5 mm Hg (10 ppm NO) to 75 +/- 3 mm Hg (dipyridamole plus 10 ppm NO) (P < 0.01). The pulmonary vasodilation obtained with NO alone could be prolonged from 12 to 42 min when inhaled NO was combined with IV dipyridamole, accounting for a time-weighted reduction in NO exposure by 72%. We conclude that dipyridamole augments the effects of NO on right ventricular afterload, allows for intermittent NO inhalation, and can significantly reduce exposure to NO. IV dipyridamole prolongs the action of inhaled nitric oxide (NO) in a piglet model of acute pulmonary hypertension. Intermittent NO inhalation combined with IV dipyridamole decreases pulmonary artery pressure for a prolonged period of time and reduces exposure to NO.

The interaction of systemic hemodynamics with hepatic flows at the time of liver transplantation (LT) has not been studied in a prospective uniform way for different types of grafts. We prospectively evaluated intraoperative hemodynamics of 103 whole and partial LT. Liver graft hemodynamics were measured using the ultrasound transit time method to obtain portal (PVF) and arterial (HAF) hepatic flow. Measurements were recorded on the native liver, the portocaval shunt, following reperfusion and after biliary anastomosis. After LT HAF and PVF do not immediately return to normal values. Increased PVF was observed after graft implantation. Living donor LT showed the highest compliance to portal hyperperfusion. The amount of liver perfusion seemed to be related to the quality of the graft. A positive correlation for HAF, PVF and total hepatic blood flow with cardiac output was found (p = 0.001). Portal hypertension, macrosteatosis >30%, warm ischemia time and cardiac output, independently influence the hepatic flows. These results highlight the role of systemic hemodynamic management in LT to optimize hepatic perfusion, particularly in LDLT and split LT, where the highest flows were registered.

Myocardial performance index (MPI) permits a relative easy estimation of global left ventricular (LV) systolic and diastolic function. It was shown that MPI inversely correlated strongly with the maximum derivative of LV pressure with respect to time (+dP/dtmax). The current study evaluated the change of MPI during and immediately after coronary artery bypass surgery (CABG) surgery and analyzed the relationship between MPI and hydraulic energy (exemplified by preload adjusted maximal power-PAMP) during that same period. The study was conducted in 45 patients undergoing CABG. After induction of anaesthesia, 10 min after revascularization and 2 h postoperatively, haemodynamics were assessed. Preload was characterized by LV end-diastolic area indexed for BSA (LVEDAI); afterload was estimated by arterial elastance (Ea) and indexed systemic vascular resistance (SVRI). Global myocardial performance was indicated in terms of MPI and contractility was achieved by PAMP. Myocardial performance index increased postoperatively (0.44 +/- 0.13, 0.37 +/- 0.17 and 0.50 +/- 0.16, respectively; P < 0.001). Preload adjusted maximal power did not alter significantly (1.90 +/- 1.24, 2.02 +/- 1.34 and 2.12 +/- 1.00 W cm(-2)*10(4), respectively). Left ventricular enddiastolic area indexed did not change. Arterial elastance augmented to 0.76 +/- 0.39, 0.80 +/- 0.40 and 1.01 +/- 0.43 mmHg ml(-1), respectively; P < 0.001. Systemic vascular resistance did not change. A relationship was found between 1-MPI/LVEDAI2 and PAMP (R2 = 0.50). This study shows that in the setting of CABG surgery, MPI appears to be a good measure of global LV function.