Pulmonary thromboendarterectomy: The Marie Lannelongue Hospital experience.

Background: Targeted medical therapy and balloon pulmonary angioplasty (BPA) entered the field of chronic thromboembolic pulmonary hypertension (CTEPH) treatment in the early 2010's. Multimodal therapy is emerging as the new gold standard for CTEPH management. Whether this change of paradigm impacted early outcomes of pulmonary endarterectomy (PEA) remains unknown. Our aim is to report our surgical experience in the era of CTEPH multimodal management. Methods: Patients who underwent PEA between 2016 and 2020 were included in the study. Early outcomes were described and compared between three groups of patients: PEA alone, PEA after targeted medical therapy induction and PEA after BPA. Results: A total of 418 patients, 225 males and 193 females, with a mean age of 59±14 years were included in the study. 336 patients underwent PEA alone, 69 after medical targeted therapy induction and 13 after unilateral BPA. Baseline preoperative pulmonary vascular resistance [4.99 (IQR, 1.71-8.48), 6.21 (IQR, 4.37-8.1), 5.03 (IQR, 4.44-7.19) wood units (WU), P=0.230, respectively] and PEA effectiveness [% decrease mean pulmonary artery pressure (mPAP), 24 (IQR, 7-42), 25 (IQR, 7-35), 23 (IQR, 3-29), P=0.580] did not differ between groups. Compared to PEA alone and PEA+BPA, the medical therapy induction group represented the most challenging group with higher baseline mPAP (45±10 vs. 42±11 and 43±11 mmHg, P=0.047), longer circulatory arrest time (30.1±15 vs. 26.6±10 and 19.6±6 min, P=0.005), higher post-PEA extracorporeal membrane oxygenation use (20.6% vs. 8.7 and 9.1%, P=0.004), higher duration on mechanical ventilation [4 (IQR, 1-12) vs. 1 (IQR, 0.5-5) and 2 (IQR, 1-3) days, P=0.005], higher complication rate (85.5% vs. 74.6% and 76.9%, P=0.052) and higher 90-day mortality (13% vs. 3.9% and 0%, P=0.002). Compared to PEA and PEA+ medical therapy induction groups, patients in the BPA induction group were older [72 (IQR, 62-76) vs. 60 (IQR, 48-69) and 62 (IQR, 52-72) years, P=0.005], and underwent shorter cardiopulmonary bypass (191.9±47.9 vs. 222±107.2 and 236.8±46.4 min, P<0.001), aortic cross clamping (54.8±21 vs. 82.7±31.4 and 80.1±32.9 min, P=0.002) and circulatory arrest time (19.6±6.2 vs. 26.6±10.8 and 30.1±15.1 min, P=0.008). Conclusions: Multimodal therapy approach to CTEPH patients did not affect effectiveness of PEA. Medical therapy and BPA could act in synergy with surgery to treat more challenging patients.

Right Ventricle Remodeling Metabolic Signature in Experimental Pulmonary Hypertension Models of Chronic Hypoxia and Monocrotaline Exposure.

INTRODUCTION: Over time and despite optimal medical management of patients with pulmonary hypertension (PH), the right ventricle (RV) function deteriorates from an adaptive to maladaptive phenotype, leading to RV failure (RVF). Although RV function is well recognized as a prognostic factor of PH, no predictive factor of RVF episodes has been elucidated so far. We hypothesized that determining RV metabolic alterations could help to understand the mechanism link to the deterioration of RV function as well as help to identify new biomarkers of RV failure. METHODS: In the current study, we aimed to characterize the metabolic reprogramming associated with the RV remodeling phenotype during experimental PH induced by chronic-hypoxia-(CH) exposure or monocrotaline-(MCT) exposure in rats. Three weeks after PH initiation, we hemodynamically characterized PH (echocardiography and RV catheterization), and then we used an untargeted metabolomics approach based on liquid chromatography coupled to high-resolution mass spectrometry to analyze RV and LV tissues in addition to plasma samples from MCT-PH and CH-PH rat models. RESULTS: CH exposure induced adaptive RV phenotype as opposed to MCT exposure which induced maladaptive RV phenotype. We found that predominant alterations of arginine, pyrimidine, purine, and tryptophan metabolic pathways were detected on the heart (LV+RV) and plasma samples regardless of the PH model. Acetylspermidine, putrescine, guanidinoacetate RV biopsy levels, and cytosine, deoxycytidine, deoxyuridine, and plasmatic thymidine levels were correlated to RV function in the CH-PH model. It was less likely correlated in the MCT model. These pathways are well described to regulate cell proliferation, cell hypertrophy, and cardioprotection. These findings open novel research perspectives to find biomarkers for early detection of RV failure in PH.

Effect of pneumoperitoneum on dynamic variables of fluid responsiveness (Delta PP and PVI) during Trendelenburg position.

BACKGROUND AND AIMS: Pulse pressure variation (ΔPP) is considered as one of the best predictors of fluid responsiveness in patients under mechanical ventilation. Pleth Variability Index (PVI) has been proposed as a noninvasive alternative. However, pneumoperitoneum has been recently suggested as a limitation to their interpretation. The aim of this study was to compare changes in ΔPP and PVI related to autotransfusion associated with a Trendelenburg maneuver before and during pneumoperitoneum. METHODS: 50 patients undergoing elective abdominal laparoscopic surgery were enrolled in this prospective observational study. All patients were equipped with an invasive radial artery catheter and a PVI probe. After obtaining a stable signal with both ΔPP and PVI, baseline values were recorded, before and after head-down tilts of 10°, with or without abdominal insufflation (10-12 mmHg). All measurements were made before any fluid challenge under standardized anaesthesia, while patients were paralyzed and mechanically ventilated with 8 mL/kg tidal volume. RESULTS: Changes in ΔPP and PVI associated with the Trendelenburg maneuver before and after insufflation of the pneumoperitoneum were significantly different (P < 0.001). In baseline conditions, the Trendelenburg maneuver was associated with a significant decrease in heart rate while mean arterial pressure remained unchanged. Both ΔPP and PVI decreased. After insufflation of the pneumoperitoneum, the Trendelenburg maneuver was associated with a significant decrease in heart rate and ΔPP and an increase in mean arterial pressure while PVI remained unchanged. CONCLUSION: Pneumoperitoneum did not alter the response of ΔPP to autotransfusion associated with the Trendelenburg maneuver, which was not the case for the PVI. This latter decreased during Trendelenburg maneuver performed alone and remained unchanged during Trendelenburg maneuver performed after insufflation of the pneumoperitoneum.

Hydroxyethyl starch for perioperative goal-directed fluid therapy in 2020: a narrative review.

BACKGROUND: Perioperative fluid management - including the type, dose, and timing of administration -directly affects patient outcome after major surgery. The objective of fluid administration is to optimize intravascular fluid status to maintain adequate tissue perfusion. There is continuing controversy around the perioperative use of crystalloid versus colloid fluids. Unfortunately, the importance of fluid volume, which significantly influences the benefit-to-risk ratio of each chosen solution, has often been overlooked in this debate. MAIN TEXT: The volume of fluid administered during the perioperative period can influence the incidence and severity of postoperative complications. Regrettably, there is still huge variability in fluid administration practices, both intra-and inter-individual, among clinicians. Goal-directed fluid therapy (GDFT), aimed at optimizing flow-related variables, has been demonstrated to have some clinical benefit and has been recommended by multiple professional societies. However, this approach has failed to achieve widespread adoption. A closed-loop fluid administration system designed to assist anesthesia providers in consistently applying GDFT strategies has recently been developed and tested. Such an approach may change the crystalloid versus colloid debate. Because colloid solutions have a more profound effect on intravascular volume and longer plasma persistence, their use in this more "controlled" context could be associated with a lower fluid balance, and potentially improved patient outcome. Additionally, most studies that have assessed the impact of a GDFT strategy on the outcome of high-risk surgical patients have used hydroxyethyl starch (HES) solutions in their protocols. Some of these studies have demonstrated beneficial effects, while none of them has reported severe complications. CONCLUSIONS: The type and volume of fluid used for perioperative management need to be individualized according to the patient's hemodynamic status and clinical condition. The amount of fluid given should be guided by well-defined physiologic targets. Compliance with a predefined hemodynamic protocol may be optimized by using a computerized system. The type of fluid should also be individualized, as should any drug therapy, with careful consideration of timing and dose. It is our perspective that HES solutions remain a valid option for fluid therapy in the perioperative context because of their effects on blood volume and their reasonable benefit/risk profile.

Pleth variability index versus pulse pressure variation for intraoperative goal-directed fluid therapy in patients undergoing low-to-moderate risk abdominal surgery: a randomized controlled trial.

BACKGROUND: Goal-directed fluid therapy (GDFT) based on dynamic indicators of fluid responsiveness has been shown to decrease postoperative complications and hospital length of stay (LOS) in patients undergoing major abdominal surgery. The usefulness of this approach still needs to be clarified in low-to-moderate risk abdominal surgery. Both pulse-pressure variation (PPV) and pleth variability index (PVI) can be used to guide GDFT strategies. The objective of this prospective randomized controlled trial was to determine if the use of PVI guided GDFT, when compared to PPV guided GDFT, would lead to similar hospital LOS in patients undergoing low-to-moderate risk surgery. Secondary outcomes included amount of fluid administered and incidence of postoperative complications. METHODS: Patients were randomized into either PVI or PPV guided GDFT groups. Both received a baseline 2 ml kg- 1 h- 1 Lactated Ringer infusion. Additional fluid boluses consisted of 250 mL of colloid that was infused over a 10 min period if PVI was > 15% or PPV was > 13% for at least five minutes. The primary outcome was to determine if hospital LOS, which was defined as the number of days from surgery up to the day the surgeon authorized hospital discharge, was equivalent between the two groups. RESULTS: A total of 76 patients were included and they were randomized into two groups of 38 patients. Baseline characteristics were similar in both groups. Both PVI and PPV guided GDFT strategies were equivalent for the primary outcome of LOS (median [interquartile range]) (days) 2.5 [2.0-3.3] vs. 3.0 [2.0-5.0], p = 0.230, respectively. Fluids infused, postoperative complications, and all other outcomes were not different between groups. CONCLUSION: In patients undergoing low-to-moderate risk abdominal surgery, PVI seems to guide GDFT similarly to PPV in regards to hospital LOS, amount of fluid, and incidence of postoperative complications. However, in low-risk patients undergoing these surgical procedures optimizing stroke volume may have limited impact on outcome. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02908256 , September 2016, retrospectively registered.

Automated Titration of Vasopressor Infusion Using a Closed-loop Controller: In Vivo Feasibility Study Using a Swine Model.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Intraoperative hypotension has been associated with adverse postoperative outcomes.A randomized controlled trial of individualized blood pressure management in patients undergoing major abdominal surgery found reduced postoperative adverse events in patients in the blood pressure management intervention group versus the standard of care group. WHAT THIS ARTICLE TELLS US THAT IS NEW: In this study of pigs with normovolemic hypotension induced by administration of sodium nitroprusside, an automated closed-loop vasopressor administration device was able to maintain mean arterial pressure within 5 mmHg of 80 mmHg for 98% of the intraoperative period. This suggests that norepinephrine can be accurately titrated using an automated infusion device in order to maintain target blood pressure. BACKGROUND: Multiple studies have reported associations between intraoperative hypotension and adverse postoperative complications. One of the most common interventions in the management of hypotension is vasopressor administration. This approach requires careful and frequent vasopressor boluses and/or multiple adjustments of an infusion. The authors recently developed a closed-loop controller that titrates vasopressors to maintain mean arterial pressure (MAP) within set limits. Here, the authors assessed the feasibility and overall performance of this system in a swine model. The authors hypothesized that the closed-loop controller would be able to maintain MAP at a steady, predefined target level of 80 mmHg for greater than 85% of the time. METHODS: The authors randomized 14 healthy anesthetized pigs either to a control group or a closed-loop group. Using infusions of sodium nitroprusside at doses between 65 and 130 µg/min, we induced four normovolemic hypotensive challenges of 30 min each. In the control group, nothing was done to correct hypotension. In the closed-loop group, the system automatically titrated norepinephrine doses to achieve a predetermined MAP of 80 mmHg. The primary objective was study time spent within ±5 mmHg of the MAP target. Secondary objectives were performance error, median performance error, median absolute performance error, wobble, and divergence. RESULTS: The controller maintained MAP within ±5 mmHg of the target for 98 ± 1% (mean ± SD) of the time. In the control group, the MAP was 80 ± 5 mmHg for 14.0 ± 2.8% of the time (P< 0.0001). The MAP in the closed-loop group was above the target range for 1.2 ± 1.2% and below it for 0.5 ± 0.9% of the time. Performance error, median performance error, median absolute performance error, wobble, and divergence were all optimal. CONCLUSIONS: In this experimental model of induced normovolemic hypotensive episodes in pigs, the automated controller titrated norepinephrine infusion to correct hypotension and keep MAP within ±5 mmHg of target for 98% of management time.

Long-term Impact of Crystalloid versus Colloid Solutions on Renal Function and Disability-free Survival after Major Abdominal Surgery.

BACKGROUND: The authors recently demonstrated that administration of balanced hydroxyethyl starch solution as part of intraoperative goal-directed fluid therapy was associated with better short-term outcomes than administration of a balanced crystalloid solution in patients having major open abdominal surgery. In the present study, a 1-yr follow-up of renal and disability outcomes in these patients was performed. METHODS: All patients enrolled in the earlier study were followed up 1 yr after surgery for renal function and disability using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS). The main outcome measure was the estimated glomerular filtration rate. Other outcomes were serum creatinine, urea, pruritus, and WHODAS score. Groups were compared on a complete-case analysis basis, and modern imputation methods were then used in mixed-model regressions to assess the stability of the findings taking into account the missing data. RESULTS: Of the 160 patients enrolled in the original study, follow-up data were obtained for renal function in 129 and for WHODAS score in 114. There were no statistically significant differences in estimated glomerular filtration rate at 1 yr (ml min 1.73 m): 80 [65 to 92] for crystalloids versus 74 [64 to 94] for colloids; 95% CI [-10 to 7], P = 0.624. However, the WHODAS score (%) was statistically significantly lower in the colloid than in the crystalloid group (2.7 [0 to 12] vs. 7.6 [1.3 to 18]; P = 0.015), and disability-free survival was higher (79% vs. 60%; 95% CI [2 to 39]; P = 0.024). CONCLUSIONS: In patients undergoing major open abdominal surgery, there was no evidence of a statistically significant difference in long-term renal function between a balanced hydroxyethyl starch and a balanced crystalloid solution used as part of intraoperative goal-directed fluid therapy, although there was only limited power to rule out a clinically significant difference. However, disability-free survival was significantly higher in the colloid than in the crystalloid group.

Implementation of closed-loop-assisted intra-operative goal-directed fluid therapy during major abdominal surgery: A case-control study with propensity matching.

BACKGROUND: Goal-directed fluid therapy (GDFT) has been associated with improved patient outcomes. However, implementation of GDFT protocols remains low despite growing published evidence and the recommendations of multiple regulatory bodies in Europe. We developed a closed-loop-assisted GDFT management system linked to a pulse contour monitor to assist anaesthesiologists in applying GDFT. OBJECTIVE: To assess the impact of our closed-loop system in patients undergoing major abdominal surgery in an academic hospital without a GDFT programme. DESIGN: A case-control study with propensity matching. SETTING: Operating rooms, Erasme Hospital, Brussels. PATIENTS: All patients who underwent elective open major abdominal surgery between January 2013 and December 2016. INTERVENTION: Implementation of our closed-loop-assisted GDFT in April 2015. METHODS: A total of 104 patients managed with closed-loop-assisted GDFT were paired with a historical cohort of 104 consecutive non-GDFT patients. The historical control group consisted of patients treated before the implementation of the closed-loop-system, and who did not receive GDFT. In the closed-loop group, the system delivered a baseline crystalloid infusion of 3 ml kg h and additional 100 ml fluid boluses of either a crystalloid or colloid for haemodynamic optimisation. MAIN OUTCOME MEASURES: The primary outcome was intra-operative net fluid balance. Secondary outcomes were composite major postoperative complications, composite minor postoperative complications and hospital length of stay (LOS). RESULTS: Baseline characteristics were similar in both groups. Patients in the closed-loop group had a lower net intra-operative fluid balance compared with the historical group (median interquartile range [IQR] 2.9 [1.6 to 4.4] vs. 6.2 [4.0 to 8.3] ml kg h; P < 0.001). Incidences of major and minor postoperative complications were lower (17 vs. 32%, P = 0.015 and 31 vs. 45%, P = 0.032, respectively) and hospital LOS shorter [median (IQR) 10 (6 to 15) vs. 12 (9 to 18) days, P = 0.022] in the closed-loop group. CONCLUSION: Implementation of our closed-loop-assisted GDFT strategy resulted in a reduction in intra-operative net fluid balance, which was associated with reduced postoperative complications and shorter hospital LOS. TRIAL REGISTRATION NUMBER: NCT02978430.

Crystalloid versus Colloid for Intraoperative Goal-directed Fluid Therapy Using a Closed-loop System: A Randomized, Double-blinded, Controlled Trial in Major Abdominal Surgery.

BACKGROUND: The type of fluid and volume regimen given intraoperatively both can impact patient outcome after major surgery. This two-arm, parallel, randomized controlled, double-blind, bi-center superiority study tested the hypothesis that when using closed-loop assisted goal-directed fluid therapy, balanced colloids are associated with fewer postoperative complications compared to balanced crystalloids in patients having major elective abdominal surgery. METHODS: One hundred and sixty patients were enrolled in the protocol. All patients had maintenance-balanced crystalloid administration of 3 ml · kg · h. A closed-loop system delivered additional 100-ml fluid boluses (patients were randomized to receive either a balanced-crystalloid or colloid solution) according to a predefined goal-directed strategy, using a stroke volume and stroke volume variation monitor. All patients were included in the analysis. The primary outcome was the Post-Operative Morbidity Survey score, a nine-domain scale, at day 2 postsurgery. Secondary outcomes included all postoperative complications. RESULTS: Patients randomized in the colloid group had a lower Post-Operative Morbidity Survey score (median [interquartile range] of 2 [1 to 3] vs. 3 [1 to 4], difference -1 [95% CI, -1 to 0]; P < 0.001) and a lower incidence of postoperative complications. Total volume of fluid administered intraoperatively and net fluid balance were significantly lower in the colloid group. CONCLUSIONS: Under our study conditions, a colloid-based goal-directed fluid therapy was associated with fewer postoperative complications than a crystalloid one. This beneficial effect may be related to a lower intraoperative fluid balance when a balanced colloid was used. However, given the study design, the mechanism for the difference cannot be determined with certainty.

Fully Automated Anesthesia and Fluid Management Using Multiple Physiologic Closed-Loop Systems in a Patient Undergoing High-Risk Surgery.

Automated delivery of anesthesia guided by processed electroencephalogram monitoring using a closed-loop system is no longer a novel concept. However, combining multiple independent physiologic closed-loop systems together has never been documented before. The purpose of this case report was to evaluate the feasibility of automated anesthesia and fluid management based on a combination of physiological variables (bispectral index, stroke volume, and stroke volume variations) using 2 independent closed-loop systems.

Perioperative goal directed therapy using automated closed-loop fluid management: the future?

 Although surgery has become much safer, it has also becoming increasingly more complex and perioperative complications continue to impact millions of patients worldwide each year. Perioperative hemodynamic optimization utilizing Goal Directed Therapy (GDT) has attracted considerable interest within the last decade due to its ability to improve postoperative short and long-term outcomes in patients undergoing higher risk surgeries. The concept of GDT in this context can be loosely defined as collecting data from minimally invasive hemodynamic monitors with the intention of using such data (flow-related parameters and/or dynamic parameters of fluid responsiveness) to titrate therapeutic interventions (intravenous fluids and/or inotropic therapy administration) with the ultimate aim of optimizing end organ tissue perfusion. Recently, the increasing amount of evidence supporting the implementation of GDT strategies has been considered so robust as to allow for the creation of national recommendations in the United Kingdom (UK), France, and Europe. These recommendations from such influential scientific societies and the potential clinical and economic benefits of GDT protocols need to also be examined within the current shift from a "pay for service" to a "pay for performance" health care system. This shift is strongly encouraged within emerging systems such as the Perioperative Surgical Home (PSH) paradigm from the United States. As a result, hospitals and clinicians around the world have become increasingly incentivized to implement perioperative hemodynamic optimization using GDT strategies within their departments. Unfortunately, its adoption continues to be quite limited and a lack of standardized criteria for perioperative fluid administrations has resulted in significant clinical variability among practitioners. This current review will provide a brief up-to-date overview of GDT, discuss current clinical practice, analyze why implementation has been limited and finally, describe the newer closed-loop GDT concept along with its potential risks and benefits.

Single-access laparoscopic adjustable gastric band removal: technique and initial experience.

BACKGROUND: Single-access laparoscopy (SAL) has gained significant interest in recent years. Potential benefits, beyond cosmetic outcomes, could be reduction of abdominal trauma, decreased risk of incisional hernia and diminished postoperative pain. Technique and initial experience in patients submitted to laparoscopic adjustable gastric band removal (LAGBR) through SAL is reported here. METHODS: Between December 2009 and March 2012, 14 patients (9 females, 5 males) underwent LAGBR through SAL. Indications for operation were band intolerance (11), pouch dilatation (2) and insufficient weight loss (1). The mean age was 40.3 ± 9.1 years (range 26-57), and the mean interval time between LAGB placement and removal was 94.7 ± 41.9 months (range 37-157). The mean weight and the mean body mass index at the time of LAGBR were 89.3 ± 17.6 kg (range 65-119) and 30.6 ± 4.5 kg/m(2) (range 25.3-36.7), respectively. Technically, the previous port site scar was used as the single-access site to the abdominal cavity. An 11-mm reusable trocar was adopted for a 10-mm regular scope, besides curved reusable instruments. RESULTS: No patients required conversion to open surgery and none necessitated additional trocars. The mean laparoscopic time was 24.6 ± 7.9 min (range 13-37), and the mean final scar length was 3.6 ± 0.3 cm (range 3-4). Two patients experienced early postoperative complications. The mean hospital stay was 1.3 ± 1.1 days (range 1-5). The mean follow-up time was of 18 ± 9.8 months (range 3-30), and there were no late complications. CONCLUSIONS: LAGBR can be safely performed through SAL. Thanks to this technique, the laparoscopic working triangulation is established as well as the ergonomic positions of the surgeon. Due the use of only reusable material, the cost of this SAL remains similar to multiport laparoscopy.