A proof of concept for microcirculation monitoring using machine learning based hyperspectral imaging in critically ill patients: a monocentric observational study.

BACKGROUND: Impaired microcirculation is a cornerstone of sepsis development and leads to reduced tissue oxygenation, influenced by fluid and catecholamine administration during treatment. Hyperspectral imaging (HSI) is a non-invasive bedside technology for visualizing physicochemical tissue characteristics. Machine learning (ML) for skin HSI might offer an automated approach for bedside microcirculation assessment, providing an individualized tissue fingerprint of critically ill patients in intensive care. The study aimed to determine if machine learning could be utilized to automatically identify regions of interest (ROIs) in the hand, thereby distinguishing between healthy individuals and critically ill patients with sepsis using HSI. METHODS: HSI raw data from 75 critically ill sepsis patients and from 30 healthy controls were recorded using TIVITA® Tissue System and analyzed using an automated ML approach. Additionally, patients were divided into two groups based on their SOFA scores for further subanalysis: less severely ill (SOFA ≤ 5) and severely ill (SOFA > 5). The analysis of the HSI raw data was fully-automated using MediaPipe for ROI detection (palm and fingertips) and feature extraction. HSI Features were statistically analyzed to highlight relevant wavelength combinations using Mann-Whitney-U test and Benjamini, Krieger, and Yekutieli (BKY) correction. In addition, Random Forest models were trained using bootstrapping, and feature importances were determined to gain insights regarding the wavelength importance for a model decision. RESULTS: An automated pipeline for generating ROIs and HSI feature extraction was successfully established. HSI raw data analysis accurately distinguished healthy controls from sepsis patients. Wavelengths at the fingertips differed in the ranges of 575-695 nm and 840-1000 nm. For the palm, significant differences were observed in the range of 925-1000 nm. Feature importance plots indicated relevant information in the same wavelength ranges. Combining palm and fingertip analysis provided the highest reliability, with an AUC of 0.92 to distinguish between sepsis patients and healthy controls. CONCLUSION: Based on this proof of concept, the integration of automated and standardized ROIs along with automated skin HSI analyzes, was able to differentiate between healthy individuals and patients with sepsis. This approach offers a reliable and objective assessment of skin microcirculation, facilitating the rapid identification of critically ill patients.

Pedicled ALT-flap for soft tissue reconstruction in the trochanteric area.

BACKGROUND: Coverage of soft tissue defects following surgery at the trochanteric area is challenging. Revision surgery in case of compromised wound healing may lead to soft tissue defects requiring reconstruction with pedicled or free flaps. Previous access to the hip joint may jeopardize neurovascular structures relevant to the flap. OBJECTIVE: In this study, we evaluated if the use of a pedicled anterior lateral thigh (ALT) flap is a valuable option for soft tissue reconstruction. METHODS: In this retrospective study, seven patients were included. Defect etiology was tumor resection in one case, screw osteosynthesis in another case and total hip arthroplasty in three cases. All patients underwent reconstruction by proximal pedicled anterior lateral thigh (ALT) flap. RESULTS: Pedicled ALT flap was a safe procedure in all cases. One patient showed delayed wound healing with need for additional surgery. No further complications were observed. CONCLUSIONS: Pedicled ALT flap transfer represents a reliable option for soft tissue coverage in the trochanteric area after primary surgery such as hip arthroplasty, osteosynthesis or tumor resection.

Bedside Hyperspectral Imaging and Organ Dysfunction Severity in Critically Ill COVID-19 Patients-A Prospective, Monocentric Observational Study.

Hyperspectral imaging (HSI) is a non-invasive technology that provides information on biochemical tissue properties, including skin oxygenation and perfusion quality. Microcirculatory alterations are associated with organ dysfunction in septic COVID-19 patients. This prospective observational study investigated associations between skin HSI and organ dysfunction severity in critically ill COVID-19 patients. During the first seven days in the ICU, palmar HSI measurements were carried out with the TIVITA® tissue system. We report data from 52 critically ill COVID-19 patients, of whom 40 required extracorporeal membrane oxygenation (ECMO). HSI parameters for superficial tissue oxygenation (StO2) and oxygenation and perfusion quality (NPI) were persistently decreased. Hemoglobin tissue content (THI) increased, and tissue water content (TWI) was persistently elevated. Regression analysis showed strong indications for an association of NPI and weaker indications for associations of StO2, THI, and TWI with sequential organ failure assessment (SOFA) scoring. StO2 and NPI demonstrated negative associations with vasopressor support and lactate levels as well as positive associations with arterial oxygen saturation. These results suggest that skin HSI provides clinically relevant information, opening new perspectives for microcirculatory monitoring in critical care.

Non-Neuronal Acetylcholinesterase Activity Shows Limited Utility for Early Detection of Sepsis.

(1) Background: Sepsis is a severe systemic inflammatory condition characterized by rapid clinical deterioration and organ dysfunction. The cholinergic system has been implicated in modulating the inflammatory response. Acetylcholinesterase (AChE), an enzyme primarily responsible for the hydrolysis of acetylcholine, has been proposed as a potential early indicator of sepsis onset. However, the exact role of non-neuronal AChE activity in sepsis and its correlation with disease severity and patient outcomes remain unclear. This study aimed to investigate the involvement of AChE activity in sepsis and evaluate its association with disease severity and clinical outcomes. (2) Methods: A prospective study included 43 septic patients. AChE activity was measured at sepsis detection, as well as 7 and 28 days later. Inflammatory biomarkers, disease severity scores, and patient outcomes were evaluated. (3) Results: AChE activity remained stable for 7 days and decreased at 28 days. However, there was no correlation between initial AChE activity and inflammatory biomarkers, disease severity scores, ICU stay, or hospital stay. (4) Conclusions: Non-neuronal AChE activity may not reliably indicate early sepsis or predict disease severity.

Targeting the Granulocytic Defense against A. fumigatus in Healthy Volunteers and Septic Patients.

Neutrophil granulocytes (NGs) are among the key players in the defense against Aspergillus fumigatus (A. fumigatus). To better elucidate a pathophysiological understanding of their role and functions, we applied a human cell model using NGs from healthy participants and septic patients to evaluate their inhibitory effects on the growth of A. fumigatus ex vivo. Conidia of A. fumigatus (ATCC® 204305) were co-incubated with NGs from healthy volunteers or septic patients for 16 h. A. fumigatus growth was measured by XTT assays with a plate reader. The inhibitory effect of NGs on 18 healthy volunteers revealed great heterogeneity. Additionally, growth inhibition was significantly stronger in the afternoon than the morning, due to potentially different cortisol levels. It is particularly interesting that the inhibitory effect of NGs was reduced in patients with sepsis compared to healthy controls. In addition, the magnitude of the NG-driven defense against A. fumigatus was highly variable among healthy volunteers. Moreover, daytime and corresponding cortisol levels also seem to have a strong influence. Most interestingly, preliminary experiments with NGs from septic patients point to a strongly diminished granulocytic defense against Aspergillus spp.

Increased Enzymatic Activity of Acetylcholinesterase Indicates the Severity of the Sterile Inflammation and Predicts Patient Outcome following Traumatic Injury.

Traumatic injury induces sterile inflammation, an immune response often associated with severe organ dysfunction. The cholinergic system acts as an anti-inflammatory in injured patients. Acetylcholinesterase (AChE), an enzyme responsible for the hydrolysis of acetylcholine, plays an essential role in controlling cholinergic activity. We hypothesized that a change in the AChE activity might indicate the severity of the traumatic injury. This study included 82 injured patients with an Injury Severity Score (ISS) of 4 or above and 40 individuals without injuries. Bedside-measured AChE was obtained on hospital arrival, followed by a second measurement 4-12 h later. C-reactive protein (CRP), white blood cell count (WBCC), and Sequential Organ Failure Assessment (SOFA) score were simultaneously collected. Injured patients showed an early and sustained increase in AChE activity. CRP remained unaffected at hospital admission and increased subsequently. Initially elevated WBCC recovered 4-12 h later. AChE activity directly correlated with the ISS and SOFA scores and predicted the length of ICU stay when measured at hospital admission. An early and sustained increase in AChE activity correlated with the injury severity and could predict the length of ICU stay in injured patients, rendering this assay a complementary diagnostic and prognostic tool at the hand of the attending clinician in the emergency unit.

Effect of Dexamethasone on the Incidence and Outcome of COVID-19 Associated Pulmonary Aspergillosis (CAPA) in Critically Ill Patients during First- and Second Pandemic Wave-A Single Center Experience.

Superinfections with Aspergillus spp. in patients with Coronavirus disease 2019 (CAPA: COVID-19-associated pulmonary aspergillosis) are increasing. Dexamethasone has shown beneficial effects in critically ill COVID-19 patients. Whether dexamethasone increases the risk of CAPA has not been studied exclusively. Moreover, this retrospective study aimed to identify risk factors for a worse outcome in critically ill COVID-19 patients. Data from 231 critically ill COVID-19 patients with or without dexamethasone treatment from March 2020 and March 2021 were retrospectively analysed. Only 4/169 (6.5%) in the DEXA-group and 13/62 (7.7%) in the Non-DEXA group were diagnosed with probable CAPA (p = 0.749). Accordingly, dexamethasone was not identified as a risk factor for CAPA. Moreover, CAPA was not identified as an independent risk factor for death in multivariable analysis (p = 0.361). In contrast, elevated disease severity (as assessed by Sequential Organ Failure Assessment [SOFA]-score) and the need for organ support (kidney replacement therapy and extracorporeal membrane oxygenation [ECMO]) were significantly associated with a worse outcome. Therefore, COVID-19 treatment with dexamethasone did not increase the risk for CAPA. Moreover, adequately treated CAPA did not represent an independent risk factor for mortality. Accordingly, CAPA might reflect patients' severe disease state instead of directly influencing outcome.

Quantitative High-Field NMR- and Mass Spectrometry-Based Fatty Acid Sequencing Reveals Internal Structure in Ru-Catalyzed Deuteration of Docosahexaenoic Acid.

Ru-based catalysis results in highly unsaturated fatty acid (HUFA) ethyl esters (EE) deuterated to various extents. The products carry 2H (D) mainly at their bis-allylic positions, where they are resistant to autoxidation compared to natural HUFA and are promising as neurological and retinal drugs. We characterized the extent of deuteration at each allylic position of docosa-4,7,10,13,16,19-hexaenoic acid deuterated to completion at bis-allylic and allylic positions (D-DHA) by two-dimensional (2D) and high-field (600 and 950 MHz) NMR. In separate experiments, the kinetics of docosahexaenoic acid (DHA) EE deuteration was evaluated using Paternò-Büchi (PB) reaction tandem mass spectrometry (MS/MS) analysis, enabling deuteration to be quantitatively characterized for isotopologues (D0-D14 DHA) at each internal allylic position. NMR analysis shows that the net deuteration of the isotopologue mixture is about 94% at the bis-allylic positions, and less than 1% remained as the protiated -CH2-. MS analysis shows that deuteration kinetics follow an increasing curve at bis-allylic positions with higher rate for internal bis-allylic positions. Percent D of bis-allylic positions increases linearly from D1 to D9 in which all internal bis-allylic positions (C9, C12, C15) deuterate uniformly and more rapidly than external bis-allylic positions (C6, C18). The mono-allylic positions near the methyl end (C21) show a steep increase of D only after the D10 isotopologue has been deuterated to >90%, while the mono-allylic position near the carboxyl position, C3, deuterates last and least. These data establish detailed methods for the characterization of Ru-catalyzed deuteration of HUFA as well as the phenomenological reaction kinetics as net product is formed.

Critically Ill COVID-19 Patients Show Reduced Point of Care-Measured Butyrylcholinesterase Activity-A Prospective, Monocentric Observational Study.

A biomarker for risk stratification and disease severity assessment in SARS-CoV-2 infections has not yet been established. Point of care testing (POCT) of butyrylcholinesterase (BChE) enables early detection of systemic inflammatory responses and correlates with disease severity in sepsis and burns. In acute care or resource-limited settings, POCT facilitates rapid clinical decision making, a particularly beneficial aspect in the management of pandemic situations. In this prospective observational study, POCT-measured BChE activity was assessed in 52 critically ill COVID-19 patients within 24 h of ICU admission and on the third and seventh day after ICU admission. Forty (77%) of these patients required venovenous extracorporeal membrane oxygenation (vvECMO). In critically ill COVID-19 patients, BChE activity is significantly decreased compared with healthy subjects, but also compared with other inflammatory conditions such as sepsis, burns, or trauma. POCT BChE activity reflects the severity of organ dysfunction and allows prediction of 28-day mortality in critically ill COVID-19 patients. Implementing early POCT BChE measurement could facilitate risk stratification and support admission and transfer decisions in resource-limited settings.

Pharmacokinetics and metabolism in mouse retina of bis-allylic deuterated docosahexaenoic acid (D-DHA), a new dry AMD drug candidate.

Docosahexaenoic acid (DHA; 22:6n-3) rich photoreceptors function in a highly oxidizing microenvironment. Lipid peroxidation and inflammation contribute to initiation and progression of eye diseases including age-related macular degeneration (AMD). Deuteration of DHA at the bis-allylic positions (D-DHA) increases its resilience to oxidative damage in vitro. We studied the pharmacokinetics of dietary D-DHA as a therapy for replacing natural retinal DHA in vivo. Mice were fed 0.5% D-DHA for 77 days then switched to natural DHA (H-DHA) for 74 days. Tissue were harvested for analyses at various time points. D-DHA substitution levels were 75%-80% in the CNS and above 90% in all other tissues by day 77. D-DHA accretion was rapid in plasma and liver (t1/2a ∼2.8 d), followed by heart and red blood cells (t1/2a ∼8.5 d), then ocular tissues (choroid-RPE, neural retina, and optic nerve with t1/2a of 10.1, 23.4, and 26.3 days, respectively), while CNS accretion was slowest (t1/2a of 29.0-44.3 days). D-DHA elimination rates were comparable to, or slower than, accretion rates except for optic nerve. Retina had very long chain D-PUFA (D-VLC-PUFA) with 5 and 6 double bonds up to C36, as well as D-EPA and D-DPA derived metabolically from D-DHA. The neural retina and optic nerve reached the therapeutic target window (20%-50%) in 2-4 weeks. Biosynthesis of D-VLC-PUFA is consistent with normal metabolism. D-DHA crosses the blood-retina-barrier, enters visually active tissues, and is metabolized as its natural DHA parent where, as shown previously (Liu et al., 2022), it protects against lipid peroxidation.

[Pedicled anterolateral thigh flap reconstruction in the region of the lower abdomen, groin, perineum, and hip]. / Die gestielte, anterolaterale Oberschenkellappenplastik zur Weichteilrekonstruktion im Bereich von Unterbauch, Leiste, Perineum und Hüfte.

OBJECTIVE: Soft tissue reconstruction of complex defects of the lower abdomen, groin, the perineum and the hip region present a reconstructive challenge. Besides free tissue transfer, pedicled flaps may also be utilized. Harvest of the vertical rectus abdominis flap causes a functional deficit by weakening the abdominal wall. Pedicled, perforator-based flaps minimize functional deficits by preserving muscle. INDICATIONS: Soft tissue defects with exposed vital structures, prosthetic devices or irradiated wound beds. CONTRAINDICATIONS: Previous surgery at the donor site, peripheral vascular disease at the pelvic and thigh region, previous vascular interventions at the donor site. SURGICAL TECHNIQUE: After preoperative localization of the perforators, a retrograde, intramuscular dissection of the pedicle allows sufficient length to be gained in order to transpose the flap into the defect. Tunneling of the flap beneath the rectus femoris muscle and Sartorius muscle is often required for tension-free inset. POSTOPERATIVE MANAGEMENT: Five days of bed-rest postoperatively followed by ambulation. RESULTS: No complete flap loss was encountered in 13 cases. In 2 cases a partial tip necrosis required secondary skin grafting.

Contextual spatial modelling in the horizontal and vertical domains.

Multi-scale contextual modelling is an important toolset for environmental mapping. It accounts for spatial dependence by using covariates on multiple spatial scales and incorporates spatial context and structural dependence to environmental properties into machine learning models. For spatial soil modelling, three relevant scales or ranges of scale exist: quasi-local soil formation processes that are independent of the spatial context, short-range catenary processes, and long-range processes related to climate and large-scale terrain settings. Recent studies investigated the spatial dependence of topsoil properties only. We hypothesize that soil properties within a soil profile were formed due to specific interactions between different features and scales of the spatial context, and that there are depth gradients in spatial and structural dependencies. The results showed that for topsoil, features at small to intermediate scales do not increase model accuracy, whereas large scales increase model accuracy. In contrast, subsoil models benefit from all scales-small, intermediate, and large. Based on the differences in relevance, we conclude that the relevant ranges of scales do not only differ in the horizontal domain, but also in the vertical domain across the soil profile. This clearly demonstrates the impact of contextual spatial modelling on 3D soil mapping.

Key characteristics impacting survival of COVID-19 extracorporeal membrane oxygenation.

BACKGROUND: Severe COVID-19 induced acute respiratory distress syndrome (ARDS) often requires extracorporeal membrane oxygenation (ECMO). Recent German health insurance data revealed low ICU survival rates. Patient characteristics and experience of the ECMO center may determine intensive care unit (ICU) survival. The current study aimed to identify factors affecting ICU survival of COVID-19 ECMO patients. METHODS: 673 COVID-19 ARDS ECMO patients treated in 26 centers between January 1st 2020 and March 22nd 2021 were included. Data on clinical characteristics, adjunct therapies, complications, and outcome were documented. Block wise logistic regression analysis was applied to identify variables associated with ICU-survival. RESULTS: Most patients were between 50 and 70 years of age. PaO2/FiO2 ratio prior to ECMO was 72 mmHg (IQR: 58-99). ICU survival was 31.4%. Survival was significantly lower during the 2nd wave of the COVID-19 pandemic. A subgroup of 284 (42%) patients fulfilling modified EOLIA criteria had a higher survival (38%) (p = 0.0014, OR 0.64 (CI 0.41-0.99)). Survival differed between low, intermediate, and high-volume centers with 20%, 30%, and 38%, respectively (p = 0.0024). Treatment in high volume centers resulted in an odds ratio of 0.55 (CI 0.28-1.02) compared to low volume centers. Additional factors associated with survival were younger age, shorter time between intubation and ECMO initiation, BMI > 35 (compared to < 25), absence of renal replacement therapy or major bleeding/thromboembolic events. CONCLUSIONS: Structural and patient-related factors, including age, comorbidities and ECMO case volume, determined the survival of COVID-19 ECMO. These factors combined with a more liberal ECMO indication during the 2nd wave may explain the reasonably overall low survival rate. Careful selection of patients and treatment in high volume ECMO centers was associated with higher odds of ICU survival. TRIAL REGISTRATION: Registered in the German Clinical Trials Register (study ID: DRKS00022964, retrospectively registered, September 7th 2020, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00022964 .

Spectral organ fingerprints for machine learning-based intraoperative tissue classification with hyperspectral imaging in a porcine model.

Visual discrimination of tissue during surgery can be challenging since different tissues appear similar to the human eye. Hyperspectral imaging (HSI) removes this limitation by associating each pixel with high-dimensional spectral information. While previous work has shown its general potential to discriminate tissue, clinical translation has been limited due to the method's current lack of robustness and generalizability. Specifically, the scientific community is lacking a comprehensive spectral tissue atlas, and it is unknown whether variability in spectral reflectance is primarily explained by tissue type rather than the recorded individual or specific acquisition conditions. The contribution of this work is threefold: (1) Based on an annotated medical HSI data set (9059 images from 46 pigs), we present a tissue atlas featuring spectral fingerprints of 20 different porcine organs and tissue types. (2) Using the principle of mixed model analysis, we show that the greatest source of variability related to HSI images is the organ under observation. (3) We show that HSI-based fully-automatic tissue differentiation of 20 organ classes with deep neural networks is possible with high accuracy (> 95%). We conclude from our study that automatic tissue discrimination based on HSI data is feasible and could thus aid in intraoperative decisionmaking and pave the way for context-aware computer-assisted surgery systems and autonomous robotics.

Large-scale investigations of Neolithic settlement dynamics in Central Germany based on machine learning analysis: A case study from the Weiße Elster river catchment.

The paper investigates potentials and challenges during the interpretation of prehistoric settlement dynamics based on large archaeological datasets. Exemplarily, this is carried out using a database of 1365 Neolithic sites in the Weiße Elster river catchment in Central Germany located between the southernmost part of the Northern German Plain and the Central Uplands. The recorded sites are systematically pre-processed with regard to their chronology, functional interpretation and spatial delineation. The quality of the dataset is reviewed by analyzing site distributions with respect to field surveys and modern land use. The Random Forests machine learning algorithm is used to examine the impact of terrain covariates on the depth of sites and pottery preservation. Neolithic settlement dynamics are studied using Site Exploitation Territories, and site frequencies per century are used to compare the intensity of land use with adjacent landscapes. The results show that the main trends of the Neolithic settlement dynamics can be derived from the dataset. However, Random Forests analyses indicate poor pottery preservation in the Central Uplands and a superimposition of Neolithic sites in the southernmost part of the Northern German Plain. Throughout the Neolithic the margins between soils on loess and the Weiße Elster floodplain were continuously settled, whereas only Early and Late Neolithic land use also extended into the Central Uplands. These settlement patterns are reflected in the results of the Site Exploitation Territories analyses and explained with environmental economic factors. Similar with adjacent landscapes the Middle Neolithic site frequency is lower compared to earlier and later periods.

Deuterated docosahexaenoic acid protects against oxidative stress and geographic atrophy-like retinal degeneration in a mouse model with iron overload.

Oxidative stress plays a central role in age-related macular degeneration (AMD). Iron, a potent generator of hydroxyl radicals through the Fenton reaction, has been implicated in AMD. One easily oxidized molecule is docosahexaenoic acid (DHA), the most abundant polyunsaturated fatty acid in photoreceptor membranes. Oxidation of DHA produces toxic oxidation products including carboxyethylpyrrole (CEP) adducts, which are increased in the retinas of AMD patients. In this study, we hypothesized that deuterium substitution on the bis-allylic sites of DHA in photoreceptor membranes could prevent iron-induced retinal degeneration by inhibiting oxidative stress and lipid peroxidation. Mice were fed with either DHA deuterated at the oxidation-prone positions (D-DHA) or control natural DHA and then given an intravitreal injection of iron or control saline. Orally administered D-DHA caused a dose-dependent increase in D-DHA levels in the neural retina and retinal pigment epithelium (RPE) as measured by mass spectrometry. At 1 week after iron injection, D-DHA provided nearly complete protection against iron-induced retinal autofluorescence and retinal degeneration, as determined by in vivo imaging, electroretinography, and histology. Iron injection resulted in carboxyethylpyrrole conjugate immunoreactivity in photoreceptors and RPE in mice fed with natural DHA but not D-DHA. Quantitative PCR results were consistent with iron-induced oxidative stress, inflammation, and retinal cell death in mice fed with natural DHA but not D-DHA. Taken together, our findings suggest that DHA oxidation is central to the pathogenesis of iron-induced retinal degeneration. They also provide preclinical evidence that dosing with D-DHA could be a viable therapeutic strategy for retinal diseases involving oxidative stress.

[Vascular diagnostics before microvascular tissue transfer on the lower extremities : An algorithm]. / Gefäßdiagnostik vor mikrovaskulärem Gewebetransfer an der unteren Extremität : Ein Algorithmus.

Microsurgical free flap transfer plays a key role in soft tissue reconstruction of the lower extremities. Through close cooperation between plastic and orthopedic surgery, great progress and success in limb salvage could be achieved over the last decades. The risk for extremity malperfusion is especially high in older patients and after trauma. To maximize the success rate for free flap transfer there is need for interdisciplinary clinical examination and diagnostics. In addition to clinical methods radiological procedures are necessary to evaluate and optimize lower extremity perfusion before surgery.Vascular ultrasound provides important information about the arterial and venous status; however, DSA, CTA and MRA are well-established and exact methods to evaluate arterial inflow. The use of less invasive methods makes it much more feasible, economic and comfortable to perform preoperative selection of patients requiring interventional procedures.In the case of intraluminal stenosis without any option for PTA, a vascular surgeon can be involved at an early stage to evaluate further surgical options. In some cases, similar surgical revascularization and free flap transfer can be performed in a single surgery. The aim of this study is to implement a standardized algorithm for preoperative examination and radiological diagnostics before reconstructive surgery of the lower extremity.

Central perforated VRAM flap and neurostimulated levator augmentation for functional and aesthetical reconstruction after abdominoperineal excision in cancer.

BACKGROUND: Preservation of quality of life regarding fecal continence after abdominoperineal excision (APE) in cancer is challenging. Simultaneous soft tissue coverage and restoration of continence mechanism can be provided through an interdisciplinary collaboration of colorectal and plastic reconstructive surgery. OBJECTIVE: Evaluation of surgical procedure and outcome combining soft tissue reconstruction using a central perforated vertical rectus abdominis myocutaneous flap (VRAM), implementing a perineostoma and restoring anorectal angle augmenting the levator ani by neurostimulated graciloplasty. METHODS: 14 Patients underwent APE due to cancer. In all patients coverage was achieved by pedicled VRAM and simultaneous pull-through descendostomy (perineostoma). 10 of those patients received a levator augmentation additionally. Postoperative complications, functional measures of continence as well as quality of life were obtained. RESULTS: Perineal minor complication rate was 43% without need of surgical intervention. All but one VRAM survived. Continence measures and disease specific life quality showed a good preservation of continence in most patients. CONCLUSION: The results present a complex therapy option accomplished by a collaboration of two highly specialized partners (visceral and plastic surgery) after total loss of the sphincter function and consecutive fecal insufficiency after APE.

Hyperspectral imaging for perioperative monitoring of microcirculatory tissue oxygenation and tissue water content in pancreatic surgery - an observational clinical pilot study.

BACKGROUND: Hyperspectral imaging (HSI) could provide extended haemodynamic monitoring of perioperative tissue oxygenation and tissue water content to visualize effects of haemodynamic therapy and surgical trauma. The objective of this study was to assess the capacity of HSI to monitor skin microcirculation and possible relations to perioperative organ dysfunction in patients undergoing pancreatic surgery. METHODS: The hyperspectral imaging TIVITA® Tissue System was used to evaluate superficial tissue oxygenation (StO2), deeper layer tissue oxygenation (near-infrared perfusion index (NPI)), haemoglobin distribution (tissue haemoglobin index (THI)) and tissue water content (tissue water index (TWI)) in 25 patients undergoing pancreatic surgery. HSI parameters were measured before induction of anaesthesia (t1), after induction of anaesthesia (t2), postoperatively before anaesthesia emergence (t3), 6 h after emergence of anaesthesia (t4) and three times daily (08:00, 14:00, 20:00 ± 1 h) at the palm and the fingertips until the second postoperative day (t5-t10). Primary outcome was the correlation of HSI with perioperative organ dysfunction assessed with the perioperative change of SOFA score. RESULTS: Two hundred and fifty HSI measurements were performed in 25 patients. Anaesthetic induction led to a significant increase of tissue oxygenation parameters StO2 and NPI (t1-t2). StO2 and NPI decreased significantly from t2 until the end of surgery (t3). THI of the palm showed a strong correlation with haemoglobin levels preoperatively (t2: r = 0.83, p < 0.001) and 6 h postoperatively (t4: r = 0.71, p = 0.001) but not before anaesthesia emergence (t3: r = 0.35, p = 0.10). TWI of the palm and the fingertip rose significantly between pre- and postoperative measurements (t2-t3). Higher blood loss, syndecan level and duration of surgery were associated with a higher increase of TWI. The perioperative change of HSI parameters (∆t1-t3) did not correlate with the perioperative change of the SOFA score. CONCLUSION: This is the first study using HSI skin measurements to visualize tissue oxygenation and tissue water content in patients undergoing pancreatic surgery. HSI was able to measure short-term changes of tissue oxygenation during anaesthetic induction and pre- to postoperatively. TWI indicated a perioperative increase of tissue water content. Perioperative use of HSI could be a useful extension of haemodynamic monitoring to assess the microcirculatory response during haemodynamic therapy and major surgery. TRIAL REGISTRATION: German Clinical Trial Register, DRKS00017313 on 5 June 2019.

Hyperspectral Imaging for the Evaluation of Microcirculatory Tissue Oxygenation and Perfusion Quality in Haemorrhagic Shock: A Porcine Study.

BACKGROUND: The ultimate goal of haemodynamic therapy is to improve microcirculatory tissue and organ perfusion. Hyperspectral imaging (HSI) has the potential to enable noninvasive microcirculatory monitoring at bedside. METHODS: HSI (Tivita® Tissue System) measurements of tissue oxygenation, haemoglobin, and water content in the skin (ear) and kidney were evaluated in a double-hit porcine model of major abdominal surgery and haemorrhagic shock. Animals of the control group (n = 7) did not receive any resuscitation regime. The interventional groups were treated exclusively with either crystalloid (n = 8) or continuous norepinephrine infusion (n = 7). RESULTS: Haemorrhagic shock led to a drop in tissue oxygenation parameters in all groups. These correlated with established indirect markers of tissue oxygenation. Fluid therapy restored tissue oxygenation parameters. Skin and kidney measurements correlated well. High dose norepinephrine therapy deteriorated tissue oxygenation. Tissue water content increased both in the skin and the kidney in response to fluid therapy. CONCLUSIONS: HSI detected dynamic changes in tissue oxygenation and perfusion quality during shock and was able to indicate resuscitation effectivity. The observed correlation between HSI skin and kidney measurements may offer an estimation of organ oxygenation impairment from skin monitoring. HSI microcirculatory monitoring could open up new opportunities for the guidance of haemodynamic management.