Evaluation Of Tissue Perfusion Research Articles

Intraoperative fluorescence-guided perfusion assessment using indocyanine green-Increased safety in gastrointestinal anastomoses?

Insufficiency of gastrointestinal anastomoses represents arelevant risk of morbidity and mortality for affected patients. The perfusion quality of the ends of the intestine is the decisive parameter for ensuring sufficient healing of an anastomosis. Intraoperative fluorescence-guided perfusion assessment with indocyanine green is increasingly being used in modern visceral surgery to evaluate tissue perfusion prior to the fashioning of gastrointestinal anastomoses. This technique provides the possibility to distinguish between adequately and inadequately perfused tissue in order to place the anastomosis in the region with the best possible perfusion. Thus, surgeons have ameasuring instrument that enables an objective assessment of the perfusion quality of the tissue to be undertaken in addition to a purely subjective macroscopic visual assessment, in order to achieve abetter functional result for the patients. Currently, however, the value of this technique has not yet been conclusively clarified. The aim of this review article is to characterize the benefits of intraoperative fluorescence-guided perfusion assessment and to classify it with respect to its significance for routine clinical practice.

Spatial and temporal patterns in dynamic-contrast enhanced intraoperative fluorescence imaging enable classification of bone perfusion in patients undergoing leg amputation.

Dynamic contrast-enhanced fluorescence imaging (DCE-FI) classification of tissue viability in twelve adult patients undergoing below knee leg amputation is presented. During amputation and with the distal bone exposed, indocyanine green contrast-enhanced images were acquired sequentially during baseline, following transverse osteotomy and following periosteal stripping, offering a uniquely well-controlled fluorescence dataset. An unsupervised classification machine leveraging 21 different spatiotemporal features was trained and evaluated by cross-validation in 3.5 million regions-of-interest obtained from 9 patients, demonstrating accurate stratification into normal, suspicious, and compromised regions. The machine learning (ML) approach also outperformed the standard method of using fluorescence intensity only to evaluate tissue perfusion by a two-fold increase in accuracy. The generalizability of the machine was evaluated in image series acquired in an additional three patients, confirming the stability of the model and ability to sort future patient image-sets into viability categories.

Near-infrared fluorescence imaging during ex vivo lung perfusion: Noninvasive real-time evaluation of regional lung perfusion and edema

ObjectiveEx vivo lung perfusion (EVLP) is an excellent platform to evaluate donor lung function before transplantation, but novel methods are needed to accurately confirm transplant quality. Near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) has been used in various clinical perioperative applications to evaluate tissue perfusion. We used NIRF imaging during pig and human EVLP to evaluate donor lung perfusion and edema. MethodsPig lungs with various degrees of lung injury (n = 10) and human lungs rejected from clinical transplantation (n = 3) were imaged during EVLP using intravascular ICG and a SPY Elite (Stryker) NIRF imaging unit. Optimal ICG and imaging conditions, and perfusion and edema quantification methods, were established. Pig lung transplants with extended graft preservation (n = 5) and control native lungs (n = 6) were also imaged. ResultsA single ICG dose resulted in sustained donor lung NIRF throughout the EVLP. Even and homogenous ICG signal was demonstrated in areas of normal lung. Low NIRF was present in regions with poor tissue perfusion, and rapid, intense ICG accumulation occurred in damaged and edematous areas. Segmental perfusion defects were common in the peripheral and elevated regions of the lungs, and serial imaging showed gradual perfusion recovery during EVLP. Impaired microvascular reperfusion, indicated by a decreased NIRF ingress rate, was detected in transplanted pig lungs early after reperfusion. ConclusionsNIRF imaging enables noninvasive real-time evaluation of lung perfusion and edema during EVLP. Prospective clinical studies are needed to determine the role of NIRF imaging in donor lung assessment and selection, and prediction of posttransplant outcomes.

Clinical utility of near-infrared perfusion assessment of the gastric tube during Ivor Lewis esophagectomy.

Anastomotic leakage (AL) after Ivor Lewis esophagectomy with intrathoracic anastomosis carries a significant morbidity. Adequate perfusion of the gastric tube (GT) is an important predictor of anastomotic integrity. Recently, near infrared fluorescent (NIRF) imaging using indocyanine green (ICG) was introduced in clinical practice to evaluate tissue perfusion. We evaluated the feasibility and efficacy of GT indocyanine green angiography (ICGA) after Ivor Lewis esophagectomy. This retrospective analysis used data from a prospectively kept database of consecutive patients who underwent Ivor Lewis (IL) esophagectomy with GT construction for cancer between January 2016 and December 2020. Relevant outcomes were feasibility, ICGA complications and the impact of ICGA on AL. 266 consecutive IL patients were identified who matched the inclusion criteria. The 115 patients operated with perioperative ICGA were compared to a control group in whom surgery was performed according to the standard of care. ICGA perfusion assessment was feasible and safe in all 115 procedures and suggested a poorly perfused tip in 56/115 (48.7%) cases, for which additional resection was performed. The overall AL rate was 16% (43/266), with 12% (33/266) needing an endoscopic our surgical intervention and 6% (17/266) needing ICU support. In univariable and multivariable analyses, ICGA was not correlated with the risk of AL (ICGA:14.8% vs non-ICGA:17.2%, p = 0.62). However, poor ICGA perfusion of the GT predicted a higher AL rate, despite additional resection of the tip (ICGA poorly perfused: 19.6% vs ICG well perfused: 10.2%, p = 0.19). ICGA is safe and feasible, but did not result in a reduction of AL. The interpretation and necessary action in case of perioperative presence of ischemia on ICGA have yet to be determined. Prospective randomized trials are warranted to analyze its benefit on AL in esophageal surgery. Trial registration Ethical approval for a prospective esophageal surgery database was granted by the Ethical committee of the Ghent University Hospital. Belgian registration number: B670201111232. Ethical approval for this retrospective data analysis was granted by our institutional EC. BC-09216.

Imaging photoplethysmography as an easy-to-use tool for monitoring changes in tissue blood perfusion during abdominal surgery

Evaluation of tissue perfusion at various stages of surgery is of great importance for the implementation of the concept of safe surgery, including operations on the abdominal organs. Currently, there is no accurate and reliable intraoperative method for assessing tissue perfusion that could help surgeons determine the risks of ischemia and improve outcomes. We propose novel method of intraoperative assessment of tissue perfusion using video camera synchronized with the electrocardiogram. The technique is referred to as imaging photoplethysmography (iPPG). It can be used continuously for monitoring blood supply to organs e.g., before and after anastomosis. In our study, we followed 14 different surgical cases (four stomach and ten colorectal cancers) requiring reconstruction of various organs with anastomosis. With iPPG, intraoperative blood perfusion was successfully visualized and quantified in all 14 patients under study. As most indicative, here we describe in detail two clinical demonstrations during gastrectomy for gastric cancer and right-sided hemicolectomy for cancer of the ascending colon. Feasibility of the iPPG system to assess blood perfusion in organs before and after anastomosis during open surgery was demonstrated for the first time.

Evaluation of Tissue Perfusion by Wound Blush and 2D Color-Coded Digital Subtraction Angiography During Endovascular Intervention and Its Impact on Limb Salvage in Critical Limb Ischemia

Purpose: Critical limb ischemia (CLI) is an entity with high mortality if not properly treated. The primary aim of CLI revascularization is to enhance wound healing, which greatly depends on microvascular circulation. The available tools for assessment of revascularization success are deficient in the evaluation of local microvascular tissue perfusion, that wound blush (WB) reflects. A reliable technique that assesses capillary flow to foot lesions is needed. This study aims to assess WB angiographically at sites of interest in the foot after revascularization and its impact on limb salvage in CLI. Materials and Methods: 198 CLI patients (Rutherford category 5/6) with infrainguinal atherosclerotic lesions amenable for endovascular revascularization (EVR) were included. Limbs were directly or indirectly revascularized by EVR. Direct revascularization meant that successful revascularization of the area of interest according to the angiosome concept was achieved. A completion angiographic run was taken to assess WB. Patients were divided into 2 groups; positive and negative WB groups. In the event of a disagreement between the observational investigators, the digital subtraction angiography (DSA) series was analyzed for hemodynamic changes with a computerized 2D color-coded DSA (Syngo iFlow). Results: 176 limbs had successful revascularization in 157 patients. The successful revascularization rate was 88.9% (176/198), with technical failure encountered in 22 limbs. 121 patients had positive WB and 55 patients had negative WB. Direct revascularization of target areas was obtained in 98 limbs (55.7%). There was a significant difference in the rate of achieving direct flow to the lesion between the positive WB and negative WB groups (36.4% vs 19.3%, p≤0.001). We noticed a nonsignificant difference between patients who had direct revascularization of the foot lesion(s) and those who had indirect revascularization as regards limb salvage. Patients were followed up for 25.2 ± 12.7 months. By the end of the first year, limb salvage rate was significantly higher in patients who had positive WB (98% vs 63%, p<0.001, after 2 years (97% vs 58%, p<0.001) and after 3 years (94% vs 51.5%, p<0.001). Conclusions: WB is an important predictor and a prognostic factor for wound healing in CLI patients with soft tissue lesions.

A Systematic Review on the Role of the Perfusion Computed Tomography in Abdominal Cancer.

Background and purposePerfusion Computed Tomography (CTp) is an imaging technique which allows quantitative and qualitative evaluation of tissue perfusion through dynamic CT acquisitions. Since CTp is still considered a research tool in the field of abdominal imaging, the aim of this work is to provide a systematic summary of the current literature on CTp in the abdominal region to clarify the role of this technique for abdominal cancer applications.Materials and MethodsA systematic literature search of PubMed, Web of Science, and Scopus was performed to identify original articles involving the use of CTp for clinical applications in abdominal cancer since 2011. Studies were included if they reported original data on CTp and investigated the clinical applications of CTp in abdominal cancer.ResultsFifty-seven studies were finally included in the study. Most of the included articles (33/57) dealt with CTp at the level of the liver, while a low number of studies investigated CTp for oncologic diseases involving UGI tract (8/57), pancreas (8/57), kidneys (3/57), and colon–rectum (5/57).ConclusionsOur study revealed that CTp could be a valuable functional imaging tool in the field of abdominal oncology, particularly as a biomarker for monitoring the response to anti-tumoral treatment.

Feasibility and Utility of Pedal Acceleration Time as Novel Assessment Tool for Limb Ischemia

A number of diagnostic tools are available to evaluate tissue perfusion in patients with peripheral artery disease (PAD). However, it is not uncommon, for patients to have noncompressible vessels, concomitant inflammation, or prior minor amputations that preclude the use of these metrics accurately and reproducibly. Recently, the pedal acceleration time (PAT) has been proposed as a novel predictor of limb ischemia. Thus, we evaluated the feasibility of using PAT as an alternative measure of limb ischemia.

Perfusion Assessment in Left-Sided/Low Anterior Resection (PILLAR III): A Randomized, Controlled, Parallel, Multicenter Study Assessing Perfusion Outcomes With PINPOINT Near-Infrared Fluorescence Imaging in Low Anterior Resection.

Indocyanine green fluoroscopy has been shown to improve anastomotic leak rates in early phase trials. We hypothesized that the use of fluoroscopy to ensure anastomotic perfusion may decrease anastomotic leak after low anterior resection. We performed a 1:1 randomized controlled parallel study. Recruitment of 450 to 1000 patients was planned over 2 years. This was a multicenter trial. Included patients were those undergoing resection defined as anastomosis within 10 cm of the anal verge. Patients underwent standard evaluation of tissue perfusion versus standard in conjunction with perfusion evaluation using indocyanine green fluoroscopy. Primary outcome was anastomotic leak, with secondary outcomes of perfusion assessment and the rate of postoperative abscess requiring intervention. This study was concluded early because of decreasing accrual rates. A total of 25 centers recruited 347 patients, of whom 178 were randomly assigned to perfusion and 169 to standard. The groups had comparable tumor-specific and patient-specific demographics. Neoadjuvant chemoradiation was performed in 63.5% of perfusion and 65.7% of standard (p > 0.05). Mean level of anastomosis was 5.2 ± 3.1 cm in perfusion compared with 5.2 ± 3.3 cm in standard (p > 0.05). Sufficient visualization of perfusion was reported in 95.4% of patients in the perfusion group. Postoperative abscess requiring surgical management was reported in 5.7% of perfusion and 4.2% of standard (p = 0.75). Anastomotic leak was reported in 9.0% of perfusion compared with 9.6% of standard (p = 0.37). On multivariate regression analysis, there was no difference in anastomotic leak rates between perfusion and standard (OR = 0.845 (95% CI, 0.375-1.905); p = 0.34). The predetermined sample size to adequately reduce the risk of type II error was not achieved. Successful visualization of perfusion can be achieved with indocyanine green fluoroscopy. However, no difference in anastomotic leak rates was observed between patients who underwent perfusion assessment versus standard surgical technique. In experienced hands, the addition of routine indocyanine green fluoroscopy to standard practice adds no evident clinical benefit. See Video Abstract at http://links.lww.com/DCR/B560. ANTECEDENTES:Se ha demostrado que la fluoroscopia con verde de indocianina mejora las tasas de fuga anastomótica en ensayos en fases iniciales.OBJETIVO:Nuestra hipótesis es que la utilización de fluoroscopia para asegurar la irrigación anastomótica puede disminuir la fuga anastomótica luego de una resección anterior baja.DISEÑO:Realizamos un estudio paralelo, controlado, aleatorizado 1:1. Se planificó el reclutamiento de 450-1000 pacientes durante 2 años.AMBITO:Multicéntrico.PACIENTES:Pacientes sometidos a resección definida como una anastomosis dentro de los 10cm del margen anal.INTERVENCIÓN:Pacientes que se sometieron a la evaluación estándar de la irrigación tisular contra la estándar en conjunto con la valoración de la irrigación mediante fluoroscopia con verde indocianina.PRINCIPALES VARIABLES EVALUADAS:El principal resultado fue la fuga anastomótica, y los resultados secundarios fueron la evaluación de la perfusión y la tasa de absceso posoperatorio que requirió intervención.RESULTADOS:Este estudio se cerró anticipadamente debido a la disminución de las tasas de acumulación. Un total de 25 centros reclutaron a 347 pacientes, de los cuales 178 fueron, de manera aleatoria, asignados a perfusión y 169 a estándar. Los grupos tenían datos demográficos específicos del tumor y del paciente similares. Recibieron quimio-radioterapia neoadyuvante el 63,5% de la perfusión y el 65,7% del estándar (p> 0,05). La anastomosis estuvo en un nivel promedio de 5,2 + 3,1 cm en perfusión en comparación con 5,2 + 3,3 cm en estándar (p> 0,05). Se reportó una visualización suficiente de la perfusión en el 95,4% de los pacientes del grupo de perfusión. El absceso posoperatorio que requirió tratamiento quirúrgico fue de 5,7% de los perfusion y en el 4,2% del estándar (p = 0,75). Se informó fuga anastomótica en el 9,0% de la perfusión en comparación con el 9,6% del estándar (p = 0,37). En el análisis de regresión multivariante, no hubo diferencias en las tasas de fuga anastomótica entre la perfusión y el estándar (OR 0,845; IC del 95% (0,375; 1,905); p = 0,34).LIMITACIONES:No se logró el tamaño de muestra predeterminado para reducir satisfactoriamente el riesgo de error tipo II.CONCLUSIÓN:Se puede obtener una visualización adecuada de la perfusión con ICG-F. Sin embargo, no se observaron diferencias en las tasas de fuga anastomótica entre los pacientes que se sometieron a evaluación de la perfusión versus la técnica quirúrgica estándar. En manos expertas, agregar ICG-F a la rutina de la práctica estándar no agrega ningún beneficio clínico evidente. Consulte Video Resumen en http://links.lww.com/DCR/B560. (Traducción-Dr Juan Antonio Villanueva-Herrero).

The Efficacy of Cone-Beam CT-Based Perfusion Mapping in Evaluation of Tissue Perfusion in Peripheral Arterial Disease.

This study investigated the use of cone-beam computed tomography (CBCT)-based perfusion mapping during percutaneous transluminal angioplasty (PTA) to predict clinical outcome in the peripheral arterial disease (PAD). From January 2016 to March 2020, 43 patients (28 male, 15 female; mean age, 69) with 51 limbs, who underwent PTA with CBCT-based foot perfusion mapping for PAD were included. Parenchymal blood volume (PBV) of foot was measured. Clinical response was investigated based on medical records. Predictive value for clinical success was evaluated using multiple logistic regression with C-statistics. Two reviewers visually assessed the improvement on angiography and CBCT-based foot perfusion mapping; inter-observer agreement of clinical success between the two were measured. Technical and clinical success rate of PTA was 90.8% and 68.6%, respectively. In multiple logistic regression, the maximum value of PBV (PBVmax) on perfusion mapping after PTA was significant (p = 0.03) for evaluating clinical success with the highest C-statistic (0.84). Using a cutoff of 235.7 mL/L for PBVmax after PTA, area under curve for prediction of clinical success was 0.664, and sensitivity and specificity were 71.4% and 68.8%, respectively. Consistency in prediction of clinical success between the two reviewers was almost perfect for CBCT-based foot perfusion mapping.

Clinical features and prognosis of severe meconium aspiration syndrome with acute respiratory distress syndrome.

To study the clinical features and prognosis of neonates with severe meconium aspiration syndrome (MAS) and acute respiratory distress syndrome (ARDS). A retrospective analysis was performed on the medical data of 60 neonates with severe MAS who were admitted from January 2017 to December 2019. According to the presence or absence of ARDS, they were divided into two groups: ARDS (n=45) and non-ARDS (n=15). Clinical features and prognosis were compared between the two groups. Among the 60 neonates with severe MAS, 45 (75%) developed ARDS. Arterial blood gas analysis showed that the ARDS group had a significantly higher median oxygenation index within 1 hour after birth than the non-ARDS group (4.7 vs 2.1, P<0.05), while there was no significant difference between the two groups in white blood cell count, C-reactive protein (CRP), and interleukin-6 (IL-6) on admission and the peak values of procalcitonin, CRP, and IL-6 during hospitalization (P>0.05). The ARDS group had a significantly higher incidence rate of shock than the non-ARDS group (84% vs 47%, P<0.05). There was no significant difference between the two groups in the incidence rates of persistent pulmonary hypertension, pneumothorax, pulmonary hemorrhage, hypoxic-ischemic encephalopathy, intracranial hemorrhage, and disseminated intravascular coagulation (P>0.05). The ARDS group required a longer median duration of mechanical ventilation than the non-ARDS group (53 hours vs 3 hours, P<0.05). In the ARDS group, 43 neonates (96%) were cured and 2 neonates (4%) died. In the non-ARDS group, all 15 neonates (100%) were cured. Neonates with severe MAS and ARDS tend to develop respiratory distress earlier, require a longer duration of mechanical ventilation, and have a higher incidence rate of shock. During the management of children with severe MAS, it is recommended to closely monitor oxygenation index, give timely diagnosis and treatment of ARDS, evaluate tissue perfusion, and actively prevent and treat shock. Citation.

Reliability of capillary refill time for evaluation of tissue perfusion in simulated vascular occluded limbs.

No standardized execution or evidence demonstrates the area of the digit giving the most accurate capillary refill time (CRT). This study investigated the reliability and validity of CRT, and the relative merits of areas where the test could be performed. In all, 127 healthy volunteers were assessed for normal CRT at the fingernail, lateral paronychia, and proximal and distal pulps of the index finger. The predictive validity of the CRT for the diagnosis of compromised vascular perfusion was also investigated on 24 subjects, using an inflated tourniquet. Three raters assessed interobserver reliability. The mean fingernail, lateralparonychia, proximalpulp, and distalpulp CRTs were 1.93, 1.78, 1.70, and 1.57s, respectively. The tourniquet and non-tourniquet results demonstrated significant mean differences; however, the fingernail showed a subtle difference (1.22s) compared with the proximal pulp (4.46s). The CRT interobserver reliability was fair at the fingernail (intraclass correlation coefficient [ICC] = 0.51), but very poor in occluded limbs (ICC = 0.13). At the lateral paronychia and finger pulp, the interobserver reliability was reasonable (ICC = 0.75-0.81 [non-tourniquet] vs 0.62-0.68 [tourniquet]). In a receiver-operating characteristic curve analysis, the proximal pulp demonstrated better discrimination (area under the curve = 0.93, 95% CI 0.89-0.97, p < 0.0001); the best cutoff point was calculated to be 3s at the proximal pulp. CRT use at appropriate areas is reliable. The most dependable site is the finger pulp, and the proposed cutoff is 3s.

Duplex echography as an adjuvant tool to clinical examination to detect early postoperative free flap vascular compromise.

Clinical examination remains the cornerstone for postoperative monitoring of free flaps but is highly dependent on the surgeon's ability and experience. Duplex echography provides a noninvasive objective evaluation of tissue perfusion. The authors hypothesized that duplex echography may be a more sensitive and specific monitoring method for early detection of postoperative flap compromise compared to clinical examination alone. The goal was to evaluate any differences between combined duplex echography and clinical examination flap monitoring versus isolated clinical evaluation. A total of 730 free flaps in 700 patients were included in the study. We conducted an intra-subject prospective study of a cohort of patients who underwent free flap reconstruction in our unit to compare clinical examination with duplex echography for postoperative monitoring. An inter-subject study was also undertaken comparing the prospective cohort with a historical control group of patients in whom free flap monitoring was made using clinical examination alone. The patency flow and velocities through the artery and vein of the flap were measured at the donor and recipient vessels of every anastomosis by duplex scanning, by the same plastic surgeon every 4 hr, during the first 18 hr after surgery. Duplex echography and clinical evaluation were used in 175 patients. The historical cohort included a total of 525 flaps. Every patient with suspicion of vascular compromise based on duplex echography was taken back for surgical re-exploration. There were no cases of overdiagnosis using duplex echography (Sensitivity 100%, Specificity 100%). Clinical evaluation detected issues with the vascularan astomoses in 23/175 flaps. However, it failed to detect 12/22 cases which presented with vascular complications and gave a false indication of possible complications in 13 flaps (Sensitivity 45%, Specificity 92%). In our practice, duplex echography is considered a useful adjunct monitoring tool for early detection of postoperative flap compromise, which compliments clinical evaluation. It provides anatomic and hemodynamic information of the vascular status and may therefore increase survival of flaps by allowing earlier detection of vascular compromise, compared to clinical examination alone, in postoperative monitoring of free flaps.

Intraoperative Indocyanine Green Fluorescence Angiography Is Sensitive for Predicting Postoperative Wound Complications in Soft-Tissue Sarcoma Surgery

Indocyanine green (ICG) angiography is a novel technology that has been predictive of postoperative wound complications. It is unknown whether this technology can successfully predict complications after sarcoma resection. In this study, we aimed to evaluate the sensitivity and specificity of ICG angiography in predicting postoperative wound complications after soft-tissue sarcoma resection. A prospective cohort study of 23 patients was performed beginning October 2017 at our institution. Patients who underwent soft-tissue sarcoma resection were included. After tumor resection and wound closure, evaluation of tissue perfusion in skin edges was performed with ICG angiography. Wound complications were recorded in the postoperative follow-up. Eight patients developed postoperative wound complications. Six patients were predicted to have wound complications on the final ICG scans. The accuracy of ICG angiography was dependent on the anatomic location, with improved accuracy in the lower extremity. ICG angiography had a sensitivity of 50%, a specificity and a positive predictive value of 100%, and a negative predictive value of 70% for wound complications after soft-tissue sarcoma resections located in the lower extremity. ICG angiography has a high predictive value in the lower extremity for postoperative wound complications. Level III, Diagnostic.

Pulse oximetry-based capillary refilling evaluation predicts postoperative outcomes in liver transplantation: a prospective observational cohort study

BackgroundCapillary refill time (CRT) is a non-invasive technique to evaluate tissue perfusion, and quantitative CRT (Q-CRT) adapted to pulse oximetry was developed with patients with sepsis and compared to blood lactate and sepsis scores. In post liver transplantation, large amounts of fluid administration are necessary for maintaining tissue perfusion to grafted liver against intravascular hypovolemia. This study aimed to evaluate whether Q-CRT can predict poor outcomes by detecting peripheral tissue perfusion abnormality in patients with liver transplantations who were treated with massive fluid administration.MethodsIn this single-center prospective cohort study, we enrolled adult patients with liver transplantations between June 2018 and July 2019. Measurement of Q-CRT was conducted at intensive care units (ICU) admission and postoperative day 1 (POD1).ResultsA total of 33 patients with liver transplantations were enrolled. Significant correlations of Q-CRT and ΔAb, a tissue oxygen delivery parameter calculated by pulse oximetry data, at ICU admission with the postoperative outcomes such as length of ICU and hospital stay and total amount of ascitic fluid discharge were observed. Quantitative CRT and ΔAb at ICU admission were significantly associated with these postoperative outcomes, even after adjusting preoperative and operative factors (MELD score and bleeding volume, respectively). However, quantitative CRT and ΔAb at POD1 and changes from ICU admission to POD1 failed to show significant associations.ConclusionsQ-CRT values were significantly associated with postoperative outcomes in liver transplantation. Although the mechanisms of this association need to be clarified further, Q-CRT may enable identification of high-risk patients that need intensive postoperative managements.

Mottling Incidence and Mottling Score According to Arterial Lactate Level in Septic Shock Patients.

ObjectivesMottling score is estimated from 0–5 according to mottling over the knee and described as clinical evaluation of tissue perfusion. This score was developed with ancient definitions of sepsis without lactate level, a major prognostic parameter when superior to 2 mmol/L. This study describes mottling incidence and mottling score in septic shock patients according to lactate level.Materials and methodsWe reanalyzed our prospective study in a French tertiary hospital in the intensive care unit (ICU) which studied mottling score and thermography correlation. Patients admitted to septic shock diagnosis and requiring vasoactive drugs were included. We recorded hemodynamic variables, mottling score, and lactate. Data collection was realized at ICU admission (H0) and after six hours (H6).ResultsForty-three patients were included. Mean age was 67 (±4), mean sequential organ failure assessment (SOFA) score was 11 (8–12), and SAPS II 58 ±20. Mortality rate at day 28 was 30%. Among patients with lactate ≥2 mmol/L, mottling was more prevalent in 82.6% vs 47.4% (p value = 0.016), and at H6 mottling score was higher (p value = 0.009). Although, mottling incidence was not different between dead (85%) and survivors (81%; p value = 0.795).ConclusionA new sepsis definition implies a new epidemiology in mottling according to lactate threshold. Patients with lactate ≥2 mmol/L presented a higher incidence and score of mottling. However, mortality was not influenced by mottling in this study.Clinical significanceArterial lactate is a major prognostic parameter when superior to 2 mmol/L.A new definition of sepsis was published in 2016 with a new paradigm and epidemiology of septic shockPatients with lactate ≥2 mmol/L presented a higher incidence and score of mottling.Mottling score is a clinical sign of microcirculatory alteration, related to lactate level in septic shock.How to cite this articleFerraris A, Bouisse C, Thiollière F, Piriou V, Allaouchiche B. Mottling Incidence and Mottling Score According to Arterial Lactate Level in Septic Shock Patients. Indian J Crit Care Med 2020;24(8):672–676.

Optimizing quantitative fluorescence angiography for visceral perfusion assessment.

Compromised tissue perfusion is a significant risk factor for anastomotic leakage after intestinal resection, leading to prolonged hospitalization, risk of recurrence after oncologic resection, and reduced survival. Thus, a tool reducing the risk of leakage is highly warranted. Quantitative indocyanine green angiography (Q-ICG) is a new method that provides surgeons with an objective evaluation of tissue perfusion. In this systematic review, we aimed to determine the optimal methodology for performing Q-ICG. A comprehensive search of the literature was performed following the PRISMA guidelines. The following databases were searched: PubMed, Embase, Scopus, and Cochrane. We included all clinical studies that performed Q-ICG to assess visceral perfusion during gastrointestinal surgery. Bias assessment was performed with the Newcastle Ottawa Scale. A total of 1216 studies were screened, and finally, 13 studies were included. The studies found that intensity parameters (maximum intensity and relative maximum intensity) could not identify patients with anastomotic leakage. In contrast, the inflow parameters (time-to-peak, slope, and t1/2max) were significantly associated with anastomotic leakage. Only two studies performed intraoperative Q-ICG while the rest performed Q-ICG retrospectively based on video recordings. Studies were heterogeneous in design, Q-ICG parameters, and patient populations. No randomized studies were found, and the level of evidence was generally found to be low to moderate. The results, while heterogenous, all seem to point in the same direction. Fluorescence intensity parameters are unstable and do not reflect clinical endpoints. Instead, inflow parameters are resilient in a clinical setting and superior at reflecting clinical endpoints.

Evaluation of Lung Quality by Near-Infrared Fluorescent Imaging during Ex Vivo Lung Perfusion

Improved real-time assessment of donor lung quality during Ex Vivo Lung Perfusion (EVLP) could enhance safe utilization of lungs for transplantation. Near-infrared (NIR) fluorescent imaging with indocyanine green (ICG) has been used in various clinical intraoperative applications to evaluate tissue perfusion. We investigated the feasibility of NIR imaging during EVLP and aimed to detect and quantify lung perfusion and permeability. Pig lungs with extended 24-hour cold ischemia (n=4) and human lungs rejected from clinical transplantation (n=2) were assessed with NIR imaging during EVLP. Serial NIR imaging was performed with SPY Elite imaging system after ICG (0.3, 0.6 or 1.0 mg) administration through pulmonary artery (Fig A). Tissue perfusion was quantified using SPYQ analysis software, and tissue ICG accumulation was correlated with lung damage. Strong NIR signal was detected immediately after ICG administration with 0.6 mg (pig lungs) or 1.0 mg (human lungs) doses resulting in optimal fluorescence for tissue perfusion evaluation. In contrast to the transient kinetics and fast liver metabolism during clinical in vivo ICG administration, a single ICG dose during EVLP resulted in stable NIR signal for over 10 hours. Perfusion quantification of pig lungs with extended cold preservation revealed peripheral areas with compromised tissue perfusion that gradually recovered over time with recruitment of additional pulmonary vascular beds (Fig B). ICG accumulation was detected in sites with damage and increased vascular permeability in pig and human lungs (Fig C and D). NIR imaging with a clinically-approved intravascularly-delivered ICG fluorescent probe can dynamically quantify tissue perfusion and detect damage-induced vascular permeability. This novel and promising imaging modality could be used during EVLP to assess lung quality, or to determine effects of therapeutics that target tissue perfusion and vascular permeability.

2D perfusion-angiography during endovascular intervention for critical limb threatening ischemia - A feasibility study.

PurposeTwo-dimensional perfusion angiography is a new method to quantify and evaluate tissue perfusion during endovascular intervention. The aim was to evaluate time-patterns and dynamics of contrast arrival and distribution before and after endovascular intervention in patients with critical limb threatening ischemia.MethodsData were collected from 37 patients with critical limb threatening ischemia due to infra-inguinal occlusive disease having a successful endovascular procedure. two-dimensional perfusion angiography was used as a post-processing software with analysis of numeric parameters related to arrival and distribution patterns of contrast.ResultsThirty-three patients were successfully analysed whereas four patients were excluded due to motion artefacts. All patients were successfully treated with recanalization of the superficial femoral, popliteal, below the knee-vessels or a combination. Short-term improvement at 30-day follow-up was noted both clinically and by ankle-brachial index and toe pressure measurements. A significant reduction in contrast arrival time between pre-and post-angioplasty runs was noted as measured by arrival time median 3.2 and interquartile range (2.5–4.2) vs. 2.6 (1.6–3.4) and time-to-peak 4.1 (3.6–5.0) vs. 3.1 (2.3–3.9) p = 0.009. An increased wash-in rate was also observed 18.3 (12.6–21) vs. 30.1 (22–30.5) p = 0.001 between pre-and post-angioplasty runs.ConclusionsThe use of perfusion angiography for evaluation of foot-circulation during endovascular interventions provides new information regarding quantitative assessment of contrast inflow before and after endovascular intervention without the need for extra contrast or runs. No selective catheterisation is necessary. The technique is easily adopted in a clinical setting. Further studies are necessary to create robust clinical endpoints.

Initial Experience with a New Quantitative Assessment Tool for Fluorescent Imaging In Peripheral Artery Disease

Introduction - Reliable perioperative/ -interventional evaluation is often limited by wounds, medial calcinosis or altered collateral supply of the foot. Especially, objective combined visual and quantitative assessment might be helpful for intra- and perioperative quality control. Aim of the study was to investigate Indocyanine green fluorescent imaging (ICG-FI) combined with a new tool for quantitative assessment to evaluate tissue perfusion of the foot before and after peripheral bypass grafting.