Real-time Perfusion Research Articles

Real-Time Perfusion and Leak Assessment in Bariatric Surgery: Bridging Traditional and Advanced Techniques.

This comprehensive literature review explores the efficacy of real-time perfusion and leak assessment methods in bariatric surgery, comparing traditional techniques with advanced imaging modalities. As the global incidence of obesity and related comorbidities rises, the demand for bariatric surgeries such as Roux-en-Y gastric bypass and sleeve gastrectomy has increased, along with the risk of serious complications like anastomotic and staple line leaks. Traditional intraoperative leak testing methods, including the air leak and methylene blue dye tests, are commonly employed but exhibit inconsistent sensitivity in leak detection. Intraoperative endoscopy, although underutilized, offers enhanced visualization and has been associated with reduced leak and complication rates in certain cases. Emerging technologies such as indocyanine green (ICG) fluorescence, laser speckle contrast imaging (LSCI), and hyperspectral imaging (HSI) provide real-time assessment of tissue perfusion, potentially improving surgical outcomes. ICG fluorescence enables visualization of blood flow to detect ischemia, while LSCI offers immediate, dye-free perfusion mapping, and HSI assesses tissue oxygenation without the need for contrast agents. Despite their promise, these technologies are limited by high costs, technical complexity, and varying accessibility, with current evidence insufficient to confirm their superiority over traditional methods. Future research should focus on large-scale, multicenter trials to validate these advanced techniques and refine their application in clinical practice. Integrating traditional and emerging methods may optimize intraoperative decision-making, reduce complications rates, and enhance patient outcomes in bariatric surgery.

Applications of Indocyanine Green (ICG) fluorescence in pediatric colorectal conditions

Postoperative success in pediatric colorectal surgery hinges on achieving adequate perfusion during complex reconstructive procedures. This review synthesizes findings from recent publications regarding the application of Indocyanine Green (ICG) in various surgical interventions for conditions such as Hirschsprung disease, anorectal malformations, cloacal reconstructions, and others.Preliminary evidence suggests that ICG fluorescence enhances intraoperative decision-making by improving vascular visualization and assessing tissue perfusion. Compared to conventional methods, ICG may offer superior evaluation of intestinal perfusion.While initial reports indicate a favorable safety profile for ICG use in pediatric patients, further prospective studies are needed to confirm these observations, quantify benefits, and assess its impact on surgical outcomes. By providing real-time perfusion data, ICG holds promise for enhancing surgical precision and improving patient outcomes in pediatric colorectal surgery.

Protocol description and initial experience in kidney graft perfusion using infrared thermography.

Protocol description for renal perfusion study using thermographic technology and description of the thermographic and clinical behavior of the transplanted kidneys before and after unclamping. Infrared thermographic images of renal grafts are obtained before kidney reperfusion, 10min after and just before closing the surgical wound. Thermographic data is evaluated together with the type of graft and donor, cold ischemia time, hypovascularized areas determined by the surgeon during surgical intervention, alterations in vascular flow in postoperative echo-Doppler, time at the beginning of graft function and serum creatinine monitoring during postoperative follow-up. 17 grafts were studied. The mean temperature of the grafts before reperfusion, 10min after and at the end of the surgery were 18.7°C (SD 6.27), 32.36°C (SD1.47) and 32.07°C (SD1.78) respectively. 4 grafts presented hypoperfused areas after reperfusion. These areas presented a lower temperature compared to the well perfused parenchyma surface using thermographic images. The study of the usefulness and applicability of thermography can allow the development of tools that provide additional objective information on organ perfusion in real time and non-invasive manner. Our protocol and initial results can contribute to provide new evidence. Further analyses should be developed to shed light on the role of this technology.

Imaging in Interventional Radiology: Applications of Contrast-Enhanced Ultrasound.

This review explores the applications of contrast-enhanced ultrasound (CEUS) in interventional radiology, focusing on its role in endoleak detection after endovascular abdominal aortic aneurysm repair (EVAR), periprocedural thermal ablation guidance, and transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). CEUS offers a dynamic assessment for the detection of endoleak following EVAR, facilitating accurate diagnosis and classification. In periprocedural thermal ablation, CEUS enhances target lesion delineation with the visualization of real-time perfusion changes, optimizing treatment strategies and reducing residual tumor rates. Finally, CEUS has demonstrated efficacy in intraprocedural evaluation and postprocedural follow-up in TACE for HCC, offering early detection of residual tumor enhancement and providing an alternative for patients with contraindications to contrast-enhanced computed tomography or magnetic resonance imaging. Overall, CEUS is a versatile and valuable tool with many applications to offer interventional radiologists enhanced diagnostic capabilities and improved patient management.

Contrast enhanced ultrasound for traumatic spinal cord injury: an overview of current and future applications

Study designSystematic review.ObjectiveContrast-enhanced ultrasound (CEUS) is an imaging modality that has only recently seen neurosurgical application. CEUS uses inert microbubbles to intraoperatively visualize vasculature and perfusion of the brain and spinal cord in real time. Observation and augmentation of spinal cord perfusion is vital component of the management of traumatic spinal cord injury, yet there are limited imaging modalities to evaluate spinal cord perfusion. CEUS provides an intraoperative imaging tool to evaluate spinal cord perfusion in real time. The objective of this review is to evaluate the current literature on the various applications and benefits of CEUS in traumatic spinal cord injury.SettingSouth Carolina, USA.MethodsThis review was written according to the PRISMA 2020 guidelines.Results143 articles were found in our literature search, with 46 of them being unique. After excluding articles for relevance to CEUS and spinal cord injury, we were left with 10 papers. Studies in animal models have shown CEUS to be an effective non-invasive imaging modality that can detect perfusion changes of injured spinal cords in real time.ConclusionThis imaging modality can provide object perfusion data of the nidus of injury, surrounding penumbra and healthy neural tissue in a traumatized spinal cord. Investigation in its use in humans is ongoing and remains promising to be an effective diagnostic and prognostic tool for those suffering from spinal cord injury.

Real-time model-based cerebral perfusion calculation for ischemic stroke

Background and ObjectivesClinical diagnosis of ischemic stroke commonly relies on examining cerebral perfusion changes by using computed tomography perfusion (CTP) techniques. However, the radiation dose in CTP is quite higher in comparison to computed tomography angiography (CTA), with associated costs and time. MethodsHence, this study established a lumped-parameter model (LPM) of brain tissue microcirculation (BTM) based on CTA, aiming to achieve real-time calculation of cerebral perfusion. After validation of calculated flow results with clinical data, the BTM-LPM model was used to examine the changes in cerebral perfusion following ischemic stroke, in which the effects of nine anatomical structures of the Circle of Willis (CoW) together with various distribution patterns of stenosis in the feeding arteries were considered. ResultsWhen compared the calculated flow results from BTM-LPM with the clinically measured data of literature, the mean squared error (MSE) value for the feeding arteries was 3.9 % and its total value for microcirculatory flow in each region was 0.1 %. Notably, the calculation time was 35.6 s. In the case of the CoW missing the left and right posterior communicating artery, a 60 % stenosis of the basilar artery is likely to cause ischemic damage to some temporal and occipital lobes of the right and left hemispheres. While in the case of the CoW missing the anterior communicating artery and the left posterior communicating artery, ischemic damage to the entire frontal lobe and parts of the temporal and parietal lobes of the left hemisphere was found when 80 % stenosis occurred in the left internal carotid artery. ConclusionsThe BTM-LPM proposed in this study could accurately calculate cerebral perfusion in real time and demonstrated the importance of CoW anatomy in different ischemic injuries to cerebral tissue. The calculated cerebral perfusion would be a reference value for early diagnosis and preoperative planning of different ischemic injuries to cerebral tissue, thereby the BTM-LPM holds great promising for replacing CTP examination.

Indocyanine green angiography for lower incidence of anastomotic leakage after transanal total mesorectal excision: a propensity score-matched cohort study.

Anastomotic leakage (AL) is the most serious complication that can arise during colorectal surgery. Indocyanine green (ICG) angiography offers an intraoperative assessment of colonic vascular perfusion in real time. We aimed to assess ICG's effects on the AL rate in patients who have undergone transanal total mesorectal excision (TaTME) for rectal cancer. This retrospective cohort study was conducted at our center from October 2018 to March 2022 to analyze the clinical data of patients with rectal cancer who have undergone TaTME after propensity score matching (PSM). The primary outcome was the proximal colonic transection line modification and clinical AL rate. A total of 143 patients in the non-ICG group and 143 patients in the ICG group were included after PSM. The proximal colonic transection line of seven patients in the non-ICG group was modified, while 18 were in the ICG group (4.9% vs. 12.5%, p = 0.023). Twenty-three patients (16.1%) in the non-ICG group and five patients (3.5%) in the ICG group were diagnosed with AL (p < 0.001). The ICG group had a less hospital readmission rate than the non-ICG group (0.7% vs. 7.7%, p = 0.003). The between-group differences in basic line and other outcomes were not significant. ICG angiography is a safe and feasible method to help surgeons identify potentially poor colonic vascular perfusion and modify the proximal colonic transection line, resulting in a significant reduction in AL and hospital readmission rates.

A Physiological Control for Artificial Heart Pump based on Adaptive Regulation of Heart Rate and the improved BAS Algorithm Optimization

In order to solve the problem that the traditional artificial heart pump has poor dynamic bionic performance and cannot respond to blood perfusion in real time according to the patient’s state, this paper proposes a new physiological control method based on adaptive adjustment of heart rate. Firstly, a coupled model of the cardiovascular circulatory system and artificial heart pump was established, and the correctness of the model is verified by hemodynamic simulation. Secondly, according to the model-free adaptive control theory, the artificial heart pump physiological control strategy for adaptive regulation of heart rate is designed, including pseudo partial derivative estimation algorithm and adaptive control law. Then, the parameters of the adaptive controller are optimized by the improved beetle antennae search algorithm. Finally, the auxiliary effect and dynamic performance of the adaptive control strategy are studied by numerical methods. The results show that the physiological control method based on adaptive regulation of heart rate realizes the adaptive modulation of heart rate and blood flow, which can meet the needs of blood perfusion in different states and help to promote the recovery of damaged heart.

The AccuFlow sensor: a novel digital health tool to assess intrapartum blood loss at cesarean delivery.

During obstetric hemorrhage, peripheral vasoconstriction maintains heart rate and blood pressure until compensatory mechanisms are overwhelmed and patients deteriorate rapidly. Real-time perfusion measurements could quantify vasoconstriction, improving early recognition of hemorrhage and facilitating early intervention to reduce morbidity and mortality. The AccuFlow device makes rapid, non-invasive, quantitative measurements of perfusion, but has not been studied for hemorrhage detection or used in surgical settings. This study evaluated feasibility, tolerability, and preliminary efficacy of the AccuFlow for assessment of blood loss at cesarean delivery (CD). In this pilot study, sensors were applied to the wrist, forearm, bicep, and chest wall of 25 patients undergoing scheduled CD. Postoperatively, sensors were removed and patients rated the AccuFlow and the standard anesthesia monitoring equipment on a validated comfort rating scale for wearable computers (CRS). Blood loss was estimated by the surgical team (EBL) and calculated from change in hematocrit, weight, and height (CBL). CRS scores were compared via Wilcoxon signed ranks tests. Coefficients of correlation between sensor readings and CBL, and between EBL and CBL, were compared using Fisher's R-to-z transformation. There were no safety events; no participants requested device removal. CRS ratings of the AccuFlow andthe standard monitoring equipment were similar (7.2vs. 8.8, p=0.25). Change in wrist perfusion from delivery to dressing placement was more strongly correlated with CBL than was EBL (R=-0.48 vs. R=0.087, p=0.03). The AccuFlow sensor is well-tolerated and shows promise in detecting intrapartum hemorrhage, though larger studies are needed.

Assessing skin microcirculation in patients at cardiovascular risk by using laser speckle contrast imaging. A narrative review.

Skin tissue holds a prominent role in microcirculatory research as an easily accessible vascular bed for the noninvasive evaluation of microvascular function. Skin microvascular changes have been associated to alterations in distinct target organs and vascular beds, reinforcing the hypothesis that skin microcirculation can be used as a model of generalized microvascular function. In addition, skin microvascular dysfunction has been documented in cardiovascular disease and patients of increased cardiovascular risk where it has been associated with multiple cardiovascular risk factors, rendering it a candidate surrogate marker of vascular damage. Laser speckle contrast imaging (LSCI) is a noninvasive, dynamic laser technique that allows assessment of skin microvascular function (SMF) by obtaining two-dimensional maps of the skin perfusion in real time with high spatial and temporal resolution and, most importantly, with the highest reproducibility compared to other laser methods. An ever-increasing number of studies using LSCI is confirming evidence of impaired SMF in several cardiovascular risk groups, therefore expanding its application in microvascular research and showing its potential clinical utility. This review attempts to present the growing importance of SMF in cardiovascular research and the emergence of LSCI technique as a robust imaging modality with a promising role to explore skin microvascular physiology. After a short description of the relevant technique and its main principle of function, we have also opted to present the most up to date studies using LSCI for the investigation of SMF in patients with cardiovascular disease as well as various groups of increased cardiovascular risk.

MP67-12 FIRST LOOK: LASER SPECKLE IMAGING IS A NOVEL METHOD TO IDENTIFY AND PRESERVE NEUROVASCULAR BUNDLE DURING ROBOTIC ASSISTED LAPAROSCOPIC RADICAL PROSTATECTOMY

You have accessJournal of UrologyCME1 Apr 2023MP67-12 FIRST LOOK: LASER SPECKLE IMAGING IS A NOVEL METHOD TO IDENTIFY AND PRESERVE NEUROVASCULAR BUNDLE DURING ROBOTIC ASSISTED LAPAROSCOPIC RADICAL PROSTATECTOMY Matt Mikula, Jay Bishoff, Louis Kavoussi, Lee Richstone, Nicholas Kavoussi, Manish Vira, Vipul Patel, and Arun Rai Matt MikulaMatt Mikula More articles by this author , Jay BishoffJay Bishoff More articles by this author , Louis KavoussiLouis Kavoussi More articles by this author , Lee RichstoneLee Richstone More articles by this author , Nicholas KavoussiNicholas Kavoussi More articles by this author , Manish ViraManish Vira More articles by this author , Vipul PatelVipul Patel More articles by this author , and Arun RaiArun Rai More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003330.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Preserving neurovascular bundle (NVB) is been previously identified as an important factor in maintaining erectile function and urinary continence after prostatectomy. Current approaches for visualizing blood flow/perfusion in real-time are: suboptimal (lack objectivity), cumbersome (need for dye preparation and injection), and lack cost-effective utility (need for large capital equipment). Laser-Speckle-Contrast-Imaging (LSCI) LSCI displays tissue blood flow via coherent laser light scatter from red blood cells without intravenous dye. Herein, we present our initial multi-center experience and feasibility with utilizing this novel technology to identify NVB during robotic assisted laparoscopic radical prostatectomy (RALP). METHODS: RALP was performed in surgeon’s respective institutions (Global Robotics Institute, FL and Northwell Health, NY) with either multiport (Da Vinci Xi) or single port (Da Vinci SP) robotic equipment. ActivSight is an FDA cleared LSCI-based endoscopic imaging module positioned between any endoscope and camera to visualize real-time perfusion. During RALP, a 10mm laparoscope with the ActivSight module was introduced on-demand through an accessory port at key points throughout the case via assistant. RESULTS: In both antegrade and retrograde nerve dissection, ActivSightTM was able to visualize NVB and demonstrate perfusion through dissection (n =15/15). Surgeons did not express any significant workflow alterations or difficulty with using ActivSight during dissection. CONCLUSIONS: To our knowledge, this is the first clinical experience describing laser speckle imaging in real-time visualization of the critical structures during RALP. LSCI provided in all cases the ability to identify and additional confidence in preserving the NVB even to highly experienced surgeons. While information presented here demonstrates some early potential promise, further research and development will be required to validate utility in the NVB preservation. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e947 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Matt Mikula More articles by this author Jay Bishoff More articles by this author Louis Kavoussi More articles by this author Lee Richstone More articles by this author Nicholas Kavoussi More articles by this author Manish Vira More articles by this author Vipul Patel More articles by this author Arun Rai More articles by this author Expand All Advertisement PDF downloadLoading ...

MP27-08 RADIAL TYPE LOW-INTENSITY EXTRACORPOREAL SHOCKWAVE THERAPY (LI-ESWT) AS NOVEL THERAPY TO ENHANCE MICROCIRCULATION IN AGING RAT PENIS

You have accessJournal of UrologyCME1 Apr 2023MP27-08 RADIAL TYPE LOW-INTENSITY EXTRACORPOREAL SHOCKWAVE THERAPY (LI-ESWT) AS NOVEL THERAPY TO ENHANCE MICROCIRCULATION IN AGING RAT PENIS Saager Chawla, Yong Sun Choi, Bae Woongjin, Samuel Sorkhi, Jae Hak Jeong, Tung-Chin Hsieh, and M. Raj Rajasekaran Saager ChawlaSaager Chawla More articles by this author , Yong Sun ChoiYong Sun Choi More articles by this author , Bae WoongjinBae Woongjin More articles by this author , Samuel SorkhiSamuel Sorkhi More articles by this author , Jae Hak JeongJae Hak Jeong More articles by this author , Tung-Chin HsiehTung-Chin Hsieh More articles by this author , and M. Raj RajasekaranM. Raj Rajasekaran More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003255.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Physiological aging is associated with the impairment of microvascular function in several organs, including the penis. Low-intensity extracorporeal shock-wave therapy (Li-ESWT) is a non-invasive intervention for the restoration of the pathological alterations of penile tissue. However, the effect of ESWT on penile microvascular function is still unclear. In addition, most previous studies have employed focused ESWT, which is known to target deeper organs, while radial ESWT is more superficial. Thus, our objective is to evaluate the effect of radial type Li-ESWT (targeting superficial penile tissue) on microvascular perfusion (MVP) in an aging rat model and elucidate a possible mechanism of action. METHODS: We anesthetized male rats (n=5; age 15-18 months) and subjected them to radial type Li-ESWT (Fig A-C) while monitoring penile hemodynamics via Laser Speckle Contrast imaging techniques immediately before and after Li-ESWT. The penile shaft was positioned beneath the ESWT applicator (HNT MEDICAL Co., Ltd, Seoul, Korea; Fig B). A level 1 intensity (L1i) (0.12 mJ/mm2) ESWT session for 500 counts at 120 HZ (Fig C) was chosen to increase blood penile microvascular perfusion (PMP). Baseline and peak PMP was assessed by the PeriCam PSI system (Perimed AB, Järfälla, Sweden). This technique quantifies PMP in arbitrary perfusion units (AU) and displays a real-time perfusion image. To assess the involvement of the nitric oxide (NO) pathway, an intracavernosal injection of L-NAME (NO synthase inhibitor) was given [200 µg/kg], and the response to ESWT was recorded again after 15 minutes. RESULTS: ESWT produced a 2-fold increase in PMP (mean±SEM) from baseline (68.456±9.021 AU) to max (163.742±11.787 AU). In addition, the L-NAME injection (n=4) resulted in a ∼40-50% decrease (from 185.293±20.604 AU to 101.008±13.077 AU) in ESWT-induced MVP response. CONCLUSIONS: Our results suggest ESWT is a novel, non-invasive intervention to improve penile circulation and treat erectile and sexual dysfunction following cancer treatment, possibly by improving penile hemodynamics and preventing penile hypoxia and fibrosis. Our findings suggest that the Li-ESWT-induced increase in MVP is mediated by the NO pathway, and future studies are warranted to confirm its efficacy in human subjects. Source of Funding: UCSD Academic Senate © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e365 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Saager Chawla More articles by this author Yong Sun Choi More articles by this author Bae Woongjin More articles by this author Samuel Sorkhi More articles by this author Jae Hak Jeong More articles by this author Tung-Chin Hsieh More articles by this author M. Raj Rajasekaran More articles by this author Expand All Advertisement PDF downloadLoading ...

Dermal Nipple-Areola Complex Perfusion through Circumareolar Scars: A Delay Model in Two-Stage Nipple-Sparing Mastectomy.

Nipple-sparing mastectomy (NSM) has evolved as a standard surgical option. The NSM complication rate remains high in large breasts. To reduce the risk of necrosis, several authors have proposed delayed procedures to enhance blood supply to the nipple-areola complex (NAC). The purpose of this study in a porcine model was to show adequate redirection of NAC perfusion by neoangiogenesis through circumareolar scars. Delayed two-staged NSM was simulated in 52 nipples (six pigs) with a 60-day interval. The nipples underwent a full-thickness, circumareolar incision onto the muscular fascia, with preservation of underlying glandular perforators. After 60 days, NSM was performed through a radial incision. A silicone sheet was introduced in the mastectomy plane to prevent NAC revascularization by wound bed imbibition. Digital color imaging was used to assess necrosis. Near-infrared fluorescence with indocyanine green was used to assess perfusion patterns and perfusion in real time. No NAC necrosis was seen after 60 days' delay in any nipples. In all nipples, indocyanine green angiography showed complete alteration of the NAC vascular perfusion pattern from subjacent gland to a capillary fill following devascularization, exhibiting a predominant arteriolar capillary blush without distinct larger vessels. NAC delay reverses glandular perfusion to adequate dermal neovascularization. Neovascularization through full-thickness scars provides sufficient dermal perfusion after 60 days' delay. Identical staged delay in humans may be a surgically safe NSM option and could broaden therapeutic NSM indications in difficult breasts. Large clinical trials are necessary to provide identical results in human breasts. NAC delay reverses glandular perfusion to adequate dermal neovascularization. Neovascularization through full-thickness scars provides sufficient dermal perfusion after 60 days of delay. Identical staged delay in humans may be a surgically safe NSM option.

Intraoperative Determination of Bronchus Stump and Anastomosis Perfusion with Hyperspectral Imaging.

The intraoperative evaluation of bronchus perfusion is limited. Hyperspectral Imaging (HSI) is a newly established intraoperative imaging technique that enables a non-invasive, real-time perfusion analysis. Therefore, the purpose of this study was to determine the intraoperative perfusion of bronchus stump and anastomosis during pulmonary resections with HSI. In this prospective, IDEAL Stage 2a study (Clinicaltrials.gov: NCT04784884) HSI measurements were carried out before bronchial dissection and after bronchial stump formation or bronchial anastomosis, respectively. Tissue oxygenation (StO2; upper tissue perfusion), organ hemoglobin index (OHI), near-infrared index (NIR; deeper tissue perfusion) and tissue water index (TWI) were calculated. Bronchus stumps showed a reduced NIR (77.82 ± 10.27 vs 68.01 ± 8.95; P = 0,02158) and OHI (48.60 ± 1.39 vs 38.15 ± 9.74; P = <.0001), although the perfusion of the upper tissue layers was equivalent before and after resection (67.42% ± 12.53 vs 65.91% ± 10.40). In the sleeve resection group, we found both a significant decrease in StO 2 and NIR between central bronchus and anastomosis region (StO2: 65.09% ± 12.57 vs 49.45 ± 9.94; P = .044; NIR: 83.73 ± 10.92 vs 58.62 ± 3.01; P = .0063). Additionally, NIR was decreased in the re-anastomosed bronchus compared to central bronchus region (83.73 ± 10.92 vs 55.15 ± 17.56; P = .0029). Although both bronchus stumps and anastomosis show an intraoperative reduction of tissue perfusion, there is no difference of tissue hemoglobin level in bronchus anastomosis.

Measurement of tissue oxygen saturation during arthroscopic surgery of knee with a tourniquet.

Tourniquets provide better tissue visibility during arthroscopic surgery. However, multiple postoperative adverse events associated with ischemia may be caused by excessive inflation pressure and duration. We aimed to evaluate the degree of tourniquet-induced ischemia using a noninvasive continuous real-time monitoring method and the relationship between changes in tissue oxygen saturation (StO2) and blood biochemical markers of ischemic injuries in patients undergoing arthroscopic knee surgery. This was a prospective observational study using near-infrared spectroscopy (NIRS). Data were collected from 29 consecutive patients who underwent arthroscopic procedures. Twenty-five patients underwent anterior cruciate ligament reconstruction, and four underwent meniscal repair. We investigated tourniquet-induced changes in StO2, monitored using NIRS, and blood biochemical markers of ischemic injuries. A significant decrease in the mean StO2 from the baseline was observed during tourniquet inflation in the operative legs. The average decrease in the mean StO2 was 58%. A comparison of mean StO2 between the nonoperative and operative legs before tourniquet deflation showed that mean values of StO2 in the operative legs were significantly lower than those in the nonoperative legs. No significant clinical relationships were observed between changes in StO2 and blood biochemical markers of ischemic injuries (creatine kinase) (p = 0.04, r = 0.38) or tourniquet duration (p = 0.05, r = 0.366). Our results demonstrated that StO2 could be used to evaluate tissue perfusion in real time but did not support the hypothesis that StO2 is a useful method for predicting the degree of tourniquet-induced injury during arthroscopic knee surgery.

Continuous monitoring of brain perfusion by cerebral oximetry after spontaneous return of circulation in cardiac arrest: a case report

BackgroundCerebral resuscitation determines the prognosis for patients who have experienced sudden death, and brain protection is the focus of clinical treatment. Cerebral resuscitation depends on the timing and quality of cardiopulmonary resuscitation (CPR). At present, cerebral oxygen monitoring is used mainly to monitor the quality of external cardiac compression and provide a prognosis for the nervous system. However, after the return of autonomous circulation, it is necessary to conduct continuous monitoring to ensure measures are taken timeously since hemodynamic instability, brain edema, and other factors may cause occult brain injury, and invasive arterial pressure cannot represent cerebral perfusion.Case presentationBy using continuous cerebral oxygen monitoring after CPR and the return of spontaneous circulation, a patient who was witnessed to have experienced sudden death in the hospital was found to have insufficient cerebral perfusion; he underwent timely intra-aortic balloon counterpulsation to improve his hemodynamics and cerebral perfusion. The patient went on to achieve a good neurological prognosis.ConclusionCerebral oxygen monitoring should be conducted throughout the treatment period; physicians should understand cerebral perfusion in real time and implement timely intervention measures to reduce occult brain injury and improve the neurological prognosis of patients.

Utility and usability of laser speckle contrast imaging (LSCI) for displaying real-time tissue perfusion/blood flow in robot-assisted surgery (RAS): comparison to indocyanine green (ICG) and use in laparoscopic surgery.

BackgroundUtility and usability of laser speckle contrast imaging (LSCI) in detecting real-time tissue perfusion in robot-assisted surgery (RAS) and laparoscopic surgery are not known. LSCI displays a color heatmap of real-time tissue blood flow by capturing the interference of coherent laser light on red blood cells. LSCI has advantages in perfusion visualization over indocyanine green imaging (ICG) including repeat use on demand, no need for dye, and no latency between injection and display. Herein, we report the first-in-human clinical comparison of a novel device combining proprietary LSCI processing and ICG for real-time perfusion assessment during RAS and laparoscopic surgeries.MethodsActivSight™ imaging module is integrated between a standard laparoscopic camera and scope, capable of detecting tissue blood flow via LSCI and ICG in laparoscopic surgery. From November 2020 to July 2021, we studied its use during elective robotic-assisted and laparoscopic cholecystectomies, colorectal, and bariatric surgeries (NCT# 04633512). For RAS, an ancillary laparoscope with ActivSight imaging module was used for LSCI/ICG visualization. We determined safety, usability, and utility of LSCI in RAS vs. laparoscopic surgery using end-user/surgeon human factor testing (Likert scale 1–5) and compared results with two-tailed t tests.Results67 patients were included in the study—40 (60%) RAS vs. 27 (40%) laparoscopic surgeries. Patient demographics were similar in both groups. No adverse events to patients and surgeons were observed in both laparoscopic and RAS groups. Use of an ancillary laparoscopic system for LSCI/ICG visualization had minimal impact on usability in RAS as evidenced by surgeon ratings of device usability (set-up 4.2/5 and form-factor 3.8/5). LSCI ability to detect perfusion (97.5% in RAS vs 100% in laparoscopic cases) was comparable in both RAS and laparoscopic cases.ConclusionsLSCI demonstrates comparable utility and usability in detecting real-time tissue perfusion/blood flow in RAS and laparoscopic surgery.Graphical abstract

Ileal long-segment ischemia after the unintended ligation of variant ileal branch during laparoscopic right hemicolectomy.

The variant terminal trunk of the superior mesenteric artery (SMA) could be confused with the ileocolic artery (ICA) as it runs on the right side of the superior mesenteric vein. If the variant ileal branch of SMA is mistaken for the ICA, unintentional ligation could cause long-segment ischemia in the ileum. We encountered a rare case of ileal ischemia caused by unintentional ligation of the variant ileal branch of the SMA during laparoscopic right hemicolectomy, which was confirmed by indocyanine green (ICG) angiography and hyperspectral imaging (HSI). Intraoperative real-time perfusion monitoring using ICG angiography and tissue oxygen saturation monitoring using HSI could help detect segments of hypoperfusion and prevent hypoperfusion-related anastomotic complications.

Laser speckle contrast imaging enables perfusion monitoring of the anterior segment during strabismus surgery: a study on the horizontal rectus muscles

BackgroundA dreaded complication of strabismus surgery is anterior segment ischaemia (ASI), caused by damage to the anterior ciliary arteries. To avoid ASI, a maximum of two rectus muscles are operated...

Laparoscopic Laser Speckle Contrast Imaging Can Visualize Anastomotic Perfusion: A Demonstration in a Porcine Model.

Background: Intestinal resection causes inevitable vascular damage, which cannot always be seen during an intraoperative clinical assessment of local intestinal perfusion. If left unaltered, impaired perfusion can lead to complications, such as anastomotic leakage (AL). Therefore, we demonstrate the use of a novel laparoscopic laser speckle contrast imaging (LSCI)-based approach in order to assess local intestinal perfusion during the construction of intestinal anastomoses. Methods: Three segments were isolated from the small intestine of a pig, while the perfusion of each was compromised by coagulating 7–8 mesenteric arteries. Both clinical assessments and LSCI were used to detect the induced perfusion deficits and to subsequently guide a transection in either a well perfused, marginally perfused, or poorly perfused tissue area within the segment. Bowel ends were then utilized for the creation of three differently perfused anastomoses: well perfused/well perfused (anastomosis segment 1), well perfused/poorly perfused (anastomosis segment 2), and poorly perfused/poorly perfused (anastomosis segment 3). After construction of the anastomoses, a final perfusion assessment using both clinical assessment and LSCI was executed in order to evaluate the vascular viability of the anastomosis. Results: Laparoscopic LSCI enabled continuous assessment of local intestinal perfusion and allowed for detection of perfusion deficits in real time. The imaging feedback precisely guided the surgical procedure, and, when evaluating the final anastomotic perfusion, LSCI was able to visualize the varying degrees of perfusion, whereas standard clinical assessment yielded only minor differences in visual appearance of the tissue. Conclusions: In this technical note, we demonstrate a novel LSCI-based approach for intraoperative perfusion assessment. With its ability to continuously visualize perfusion in real time, laparoscopic LSCI has significant potential for the optimization of anastomotic surgery in the near future.