Blood Pressure and Mortality in the 4D Study.

INTRODUCTION: Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) are risk factors for cardiovascular mortality (CVM). Pulse pressure (PP) is an easily available parameter of vascular stiffness, but its impact on CVM in chronic dialysis patients with diabetes is unclear. METHODS: Therefore, we have examined the predictive value of baseline, predialytic PP, SBP, DBP, and MAP in the German Diabetes and Dialysis (4D) study, a prospective, randomized, double-blind trial enrolling 1,255 patients with type 2 diabetes on hemodialysis in 178 German dialysis centers. RESULTS: Mean age was 66.3 years, mean blood pressure 146/76 mm Hg, mean time suffering from diabetes 18.1 years, and mean time on maintenance dialysis 8.3 months. Considered as continuous variables, PP, MAP, SBP, and DBP could not provide a significant mortality prediction for either cardiovascular or all-cause mortality. After dividing the cohort into corresponding tertiles, we also did not detect any significant mortality prediction for PP, SBP, DBP, or MAP, both for all-cause mortality and CVM after adjusting for age and sex. Nevertheless, when comparing the HR plots of the corresponding blood pressure parameters, a pronounced U-curve was seen for PP for both all-cause mortality and CVM, with the trough range being 70-80 mm Hg. DISCUSSION: In patients with end-stage renal disease and long-lasting diabetes mellitus predialytic blood pressure parameters at study entry are not predictive for mortality, presumably because there is a very high rate of competing mortality risk factors, resulting in overall very high rates of all-cause and CVM that may no longer be significantly modulated by blood pressure control.

Prognostic value of extended cardiac risk assessment before elective open abdominal aortic surgery.

BACKGROUND: Major vascular surgery is associated with a high perioperative risk and significant mortality. Despite advances in risk stratification, monitoring, and management of perioperative complications, cardiac complications are still common. Stress echocardiography is well established in coronary artery disease diagnostics; however, its prognostic value before high-risk aortic surgery is unknown. This prospective, single-center study compared the outcome of patients undergoing extended cardiac risk assessment before open abdominal aortic surgery with the outcome of patients who had received standard preoperative assessment. METHODS: The study included patients undergoing elective open abdominal aortic surgery. Patients who underwent standard preoperative assessment before the start of a dedicated protocol were compared with patients who had extended cardiac risk assessment, including dobutamine stress echocardiography, as part of a stepwise interdisciplinary cardiovascular team approach. The combined primary endpoint was cardiovascular death, myocardial infarction, emergency coronary revascularization, and life-threatening arrhythmia within 30 days. The secondary endpoint was acute renal failure and severe bleeding. RESULTS: In total, 77 patients (mean age 68.1 ± 8.1 years, 70% male) were included: 39 underwent standard and 38 underwent cardiac risk assessment. The combined primary endpoint was reached significantly more often in patients before than after implementation of the extended cardiac stratification procedure (15% vs. 0%, p = 0.025). The combined secondary endpoint did not differ between the groups. CONCLUSIONS: Patients with extended cardiac risk assessment undergoing elective open abdominal aortic surgery had better 30-day outcomes than did those who had standard preoperative assessment.

First experiences of ultrasound vector flow imaging at the femoropopliteal artery in peripheral arterial disease.

Background: The femoropopliteal artery (FPA) plays a central role in diagnosing and treating peripheral arterial disease (PAD). FPA lesions are the most frequent cause of intermittent claudication, and no other artery of the lower extremities is recanalised more frequently. Generally, ultrasound is the primary imaging tool in PAD, particularly FPA. With the development of high-frame-rate ultrasound technology in addition to traditional ultrasound modes, vector flow imaging (VFI) has provided deeper haemodynamic insights when used in the carotid artery. Here, we report the use of VFI at the FPA level in routine PAD examinations. Patients and methods: In this single-centre prospective study, we evaluated consecutive patients with PAD using B-mode imaging, colour Doppler, pulsed wave Doppler (PW) and vector flow. Hemodynamic parameters at predefined locations at the carotid artery and FPA were compared. Results: Qualitatively adequate VFI at all sites was possible in 76% of the patients with PAD. With decreasing volume flow from the common carotid artery to the internal carotid artery and from the common femoral artery via the superficial femoral artery to the popliteal artery, the correlation between VFI- and PW-derived-volume flow was high at every site. Based on different techniques, the VFI-derived values were significantly lower than the PW-derived values. The mean wall shear stress was significantly lower at all femoropopliteal sites than at the carotid sites, whereas the oscillatory shear index at the femoral site was higher than that at the carotid sites rather than at the popliteal location. Conclusions: Our findings suggest that vector flow data acquisition in the FPA is feasible in most patients with PAD. Therefore, with knowledge of the method and its limitations, VFI provides haemodynamic information beyond traditional ultrasound techniques and is a promising new tool for flow analysis in PAD.

Intermittent negative pressure therapy in patients with no-option chronic limb-threatening ischemia.

Background: Aim of this study was to assess the influence of intermitted negative pressure (INP) therapy on the foot microcirculation in patients with no-option CLTI. Patients and methods: CLTI patients defined as no option for revascularization on the basis of an interdisciplinary vascular board decision (interventional radiology, vascular surgery) were included in this study. INP therapy was performed at home. Therapy regime was: 1 hour twice daily. Follow-up was after 6 weeks and 3 months. Microcirculation measurement was performed by laser Doppler flowmetry and white light spectrometry (oxygen to see, O2CTM). Following parameters were evaluated: oxygen saturation (sO2 in%), relative hemoglobin (rHb) and flow (in arbitrary units A.U.). Additionally the clinical outcome of the patients was assessed. Results: From September 2020 to June 2022, 228 patients were screened. In total 19 patients (13 men, 6 women, mean age was 73.95 years) were included. 6 weeks after INP therapy the microcirculation showed a significant improvement for the parameter sO2 (%) (p=0.004). After 3 months a non-significant decrease compared to 6 weeks follow-up was seen for the parameter sO2; however, the perfusion was still improved compared to baseline measurement. With regard to the microperfusion values flow (AU) and hemoglobin (AU), the changes were not significant. Clinically, the patients reported a significant reduction of rest pain after therapy (p=0.005). Conclusions: INP therapy in no-option CLTI patients showed a significant improvement of the skin perfusion after 6 weeks. Therefore, INP therapy might have therapeutic potential in these critical ill patients.

[Fluorescence-guided Lymph Vessel Sealing in Systematic Nodal Dissection: a New Surgical Technique to Prevent Lymphorrhea and Lymphocele.] / Fluoreszenzgesteuerte Lymphgefäßversiegelung bei der systematischen Lymphknotendissektion zur Vermeidung von Lymphfisteln und Lymphozelen.

INTRODUCTION: The primary morbidities of inguinal and axillary systematic nodal dissection are lymphatic fistulas and seromas. Intraoperative fluorescence imaging-guided sealing of lymph vessels may prevent these postoperative complications. METHODS: Indocyanine dye was injected intracutaneously into the distal limb before the beginning of the lymphadenectomy. Systematic nodal dissection was performed according to standard protocols. Near-infrared imaging was applied throughout the procedure and real-time fluorescence-guided lymph vessel sealing was performed. RESULTS: Fluorescence-guided lymph vessel sealing was implemented in three patients undergoing axillary systematic lymph node dissection. No adverse events occurred following fluorescence dye injection. All patients could be discharged free of wound complications. CONCLUSION: Fluorescence-guided lymph vessel sealing might be a promising new technique for preventing lymphatic fistulas and lymphocele after systematic lymphadenectomy.

Quantitative Assessment of Intraoperative Laser Fluorescence Angiography With Indocyanine Green Predicts Early Graft Function After Kidney Transplantation.

OBJECTIVE: This study was designed to demonstrate the predictive ability of quantitative indocyanine green (ICG) fluorescence angiography for the short-term postoperative outcome, the occurrence of delayed graft function (DGF), and long-term graft survival. SUMMARY BACKGROUND DATA: DGF is a relevant problem after kidney transplantation; sufficient microperfusion of the allograft is crucial for postoperative organ function. Fluorescence angiography with ICG can serve as an intraoperative quality control of microperfusion. METHODS: This prospective diagnostic study, conducted in 2 German transplantation centers from November 2015 to October 2018, included 128 consecutive kidney transplantations. Intraoperative assessment of the allograft microperfusion was performed by near-infrared fluorescence angiography with ICG; a software was used for quantitative analysis. The associations between perfusion parameters (eg, ICG Ingress) and donor, recipient, peri-procedural, and postoperative characteristics were evaluated. RESULTS: DGF occurred in 23 (24%) kidney recipients from deceased donors. ICG Ingress ( P = 0.0027), donor age ( P = 0.0452), recipient age ( P = 0.0139), and recipient body mass index ( P = 0.0017) were associated with DGF. ICG Ingress correlated significantly with recipient age (r = -0.27662, P = 0.0016), cold and warm ischemia time (r = -0.25204, P = 0.0082; r = -0.19778, P = 0.0283), operating time (r = -0.32208, P = 0.0002), eGFR on postoperative days 1 (r =+0.22674, P = 0.0104) and 7 (r = +0.33189, P = 0.0001). The cutoff value for ICG Ingress was 106.23 AU with sensitivity of 78.3% and specificity of 80.8% ( P < 0.0001) for the prediction of DGF. CONCLUSION: Fluorescence angiography with ICG allows intraoperative quantitative assessment of microperfusion during kidney transplantation. The parameter ICG Ingress reflects recipient and procedure characteristics and is able to predict the incidence of DGF. TRIAL REGISTRATION: Clinicaltrials.gov: NCT-02775838.

Definition and severity grading of postoperative lymphatic leakage following inguinal lymph node dissection.

PURPOSE: Lymphatic complications occur frequently after radical inguinal lymph node dissection (RILND). The incidence of lymphatic leakage varies considerably among different studies due to the lack of a consistent definition. The aim of the present study is to propose a standardized definition and grading of different types of lymphatic leakage after groin dissection. METHODS: A bicentric retrospective analysis of 82 patients who had undergone RILND was conducted. A classification of postoperative lymphatic leakage was developed on the basis of the daily drainage output, any necessary postoperative interventions and reoperations, and any delay in adjuvant treatment. RESULTS: In the majority of cases, RILND was performed in patients with inguinal metastases of malignant melanoma (n = 71). Reinterventions were necessary in 15% of the patients and reoperations in 32%. A new classification of postoperative lymphatic leakage was developed. According to this definition, grade A lymphatic leakage (continued secretion of lymphatic fluid from the surgical drains without further complications) occurred in 13% of the patients, grade B lymphatic leakage (persistent drainage for more than 10 postoperative days or the occurrence of a seroma after the initial removal of the drain that requires an intervention) in 28%, and grade C lymphatic leakage (causing a reoperation or a subsequent conflict with medical measures) in 33%. The drainage volume on the second postoperative day was a suitable predictor for a complicated lymphatic leakage (grades B and C) with a cutoff of 110 ml. CONCLUSION: The proposed definition is clinically relevant, is easy to employ, and may serve as the definition of a standardized endpoint for the assessment of lymphatic morbidity after RILND in future studies.

Quantitative assessment of microperfusion by indocyanine green angiography in kidney transplantation resembles chronic morphological changes in kidney specimens.

OBJECTIVE: ICG fluorescence angiography enables a quantitative real-time perfusion assessment in kidney transplantation. The results of intraoperative microperfusion of the kidney allograft were compared to the renal chronicity score in pre-transplantation kidney biopsy specimens. The intrarenal resistance index was calculated by duplex sonography as a method of reference. METHODS: Seventy-seven patients with end-stage renal disease undergoing kidney transplantation were prospectively included in two centers. Correlation analysis of chronic changes in kidney biopsy specimens and the IN of ICG fluorescence signal were investigated. RESULTS: The results yielded a significantly negative correlation for the renal chronicity (r = -0.294, P = 0.017) as well as the intestinal fibrosis and tubular atrophy score (r = -0.328, P = 0.007). There was a significant inverse relationship between the IN and the mean RI values of the upper pole of the kidney allograft. CONCLUSIONS: In summary, fluorescence angiography reflects preexisting morphological changes of the renal cortex. ICG angiography may serve as an alternative method for the assessment of microperfusion of the kidney allograft.

Tissue sealants for the prevention of lymphoceles after radical inguinal lymph node dissection in patients with melanoma: A systematic review and individual patient data meta-analysis.

BACKGROUND AND OBJECTIVES: Postoperative lymphoceles and further wound complications occur frequently after radical inguinal lymph node dissection (ILND). In various studies, tissue sealants have shown to reduce the incidence of postoperative morbidity. METHODS: A systematic review and meta-analysis of randomized controlled trials (RCTs) investigating the effectiveness of tissue sealants in reducing the incidence of postoperative lymphoceles following ILND in patients with melanoma was conducted. Individual patient data was requested to pool the data for meta-analysis appropriately. RESULTS: Thousand seven hundred twenty-nine manuscripts were screened for eligibility. Six RCTs published between 1986 and 2012 were identified including 194 patients for ILND. Only four RCTs were included in the meta-analysis. No study properly defined the term "lymphocele." Tissue sealants failed to influence the duration of drain placement (mean difference [MD] = -3.05 days; z = 1.18; P = 0.24), total drainage volume (MD = 598.39 mL; z = 1.49; P = 0.14), the incidence of postoperative seroma, wound infection and skin necrosis. CONCLUSIONS: No improvement was identified with the use of tissue sealants, however, a valid comparison of the results of included trials was difficult owing to the lack of a definition of the term "lymphocele." Other surgical techniques and trials using validated endpoint definitions are required to reevaluate these findings.

[Intraoperative Indocyanine Green Fluorescence to Assure Vital Parathyroids in Thyroid Resections]. / Intraoperative Indocyaningrün-Fluoreszenzbildgebung zur Sicherung vitaler Nebenschilddrüsen bei Schilddrüsenresektionen.

INTRODUCTION: Total thyreoidectomy is associated with high rates of temporary or permanent hypoparathyroidism. During surgery, ICG fluorescence angiography can be used to detect and preserve well vascularised parathyroid glands; this technique has been recently introduced in retrospective and prospective trials as an intraoperative technical support to avoid postoperative hypoparathyroidism. MATERIALS UND METHODS: 27 patients undergoing total thyreoidectomy were prospectively enrolled in our study. The vascularisation of the parathyroid glands was analysed intraoperatively using ICG tissue angiography. 5 mg indocyanine green were intravenously administered. Fluorescence angiography was evaluated in real time using the PinPoint (Novadaq, Canada) imaging system. The study was approved by the local ethics committee. RESULTS: ICG fluorescence angiography was performed uneventfully in all cases. There was no case of postoperative hypoparathyroidism when at least one parathyroid gland with high fluorescence intensity was preserved. In 4 cases, only low fluorescence intensity was detected in the remaining parathyroid glands after completing the resection. All 4 patients received activated vitamin D3 prophylactically. Two of 4 developed symptomatic hypocalcaemia due to temporary hypoparathyroidism. CONCLUSION: Implementation of ICG fluorescence angiography can help in predicting and therefore preventing postoperative hypoparathyreoidism after total thyreoidectomy. If a well vascularised parathyroid gland with high ICG fluorescence intensity can be secured, calcium substitution and postoperative prophylaxis of hypoparathyreoidism may become obsolete in the future.

Dosing of indocyanine green for intraoperative laser fluorescence angiography in kidney transplantation.

OBJECTIVE: Sufficient blood supply is a crucial factor determining postoperative allograft function in kidney transplantation. Therefore, besides the surgeon's individual impression, a method for evaluating the quality of the organ's microperfusion is required. Laser fluorescence angiography with indocyanine green (ICG) is an emerging tool for this purpose. However, no reproducible quantification of ICG fluorescence has been performed in transplantation so far. METHODS: This retrospective two-center study was designed to evaluate the dosing of ICG for intraoperative laser fluorescence angiography in kidney transplantation. The Spy Elite® system (NOVADAQ, Canada) was employed for quantitative assessment of allograft microperfusion. ICG was administered systemically 5 minutes after reperfusion applying doses between 0.25 and 0.01 mg ICG per kg body weight. Quantitative assessment was performed with the implemented SPY-Q Software. RESULTS: A total of 57 kidney recipients were included in two centers. The generated curves showing ICG IN and EgR were not evaluable due to oversensing when doses exceeded 0.02 mg per kg body weight. CONCLUSIONS: Fluorescence angiography with ICG is an emerging tool for the intraoperative quality control and evaluation of microperfusion in kidney transplantation. A dose of 0.02 mg ICG per kg body weight is recommended to ensure the quantitative assessment with SPY-Q.

The Effect of Revascularization on Lower Limb Circulation Parameters in Symptomatic Peripheral Arterial Disease.

Background: The prevalence of peripheral arterial disease and the number of revascularization procedures performed in symptomatic patients are steadily increasing. However, uncertainties remain regarding hemodynamic monitoring after revascularization and the prediction of clinical outcomes. This study aimed to investigate hemodynamic parameters with a focus on the microvasculature. Methods: This prospective, single-center study included 29 patients (15 with intermittent claudication [IC] and 14 with chronic limb-threatening ischemia [CLTI]). Before and after the revascularization procedure, in addition to the ankle-brachial index (ABI), microperfusion parameters, including microvascular blood flow, capillary oxygen saturation (SO2), and relative hemoglobin content (rHb), were assessed with lightguide spectrophotometry combined with laser Doppler flowmetry using an oxygen-to-see (O2C) device in the horizontal and elevated leg positions. Results: At baseline, SO2 in the elevated leg position was significantly lower in patients with CLTI than in those with IC (p = 0.0189), whereas the other microcirculatory parameters and ABI values were not significantly different. Patients with diabetes mellitus had a higher flow rate than those without in the horizontal leg position (p = 0.0162) but not in the elevated leg position. After successful revascularization, the flow increased immediately and significantly in both positions, whereas SO2, rHb, and the ABI did not. Conclusions: Elevated leg SO2 was significantly lower in CLTI than in clinically compensated peripheral arterial disease, whereas microvascular flow was a suitable surrogate parameter indicating successful revascularization. In studies using surgical or interventional revascularization procedures, noninvasive hemodynamic monitoring of the microcirculation at the foot level might be beneficial.

Streamlining Acute Abdominal Aortic Dissection Management-An AI-based CT Imaging Workflow.

Life-threatening acute aortic dissection (AD) demands timely diagnosis for effective intervention. To streamline intrahospital workflows, automated detection of AD in abdominal computed tomography (CT) scans seems useful to assist humans. We aimed at creating a robust convolutional neural network (CNN)-based pipeline capable of real-time screening for signs of abdominal AD in CT. In this retrospective study, abdominal CT data from AD patients presenting with AD and from non-AD patients were collected (n 195, AD cases 94, mean age 65.9 years, female ratio 35.8%). A CNN-based algorithm was developed with the goal of enabling a robust, automated, and highly sensitive detection of abdominal AD. Two sets from internal (n = 32, AD cases 16) and external sources (n = 1189, AD cases 100) were procured for validation. The abdominal region was extracted, followed by the automatic isolation of the aorta region of interest (ROI) and highlighting of the membrane via edge extraction, followed by classification of the aortic ROI as dissected/healthy. A fivefold cross-validation was employed on the internal set, and an ensemble of the 5 trained models was used to predict the internal and external validation set. Evaluation metrics included receiver operating characteristic curve (AUC) and balanced accuracy. The AUC, balanced accuracy, and sensitivity scores of the internal dataset were 0.932 (CI 0.891-0.963), 0.860, and 0.885, respectively. For the internal validation dataset, the AUC, balanced accuracy, and sensitivity scores were 0.887 (CI 0.732-0.988), 0.781, and 0.875, respectively. Furthermore, for the external validation dataset, AUC, balanced accuracy, and sensitivity scores were 0.993 (CI 0.918-0.994), 0.933, and 1.000, respectively. The proposed automated pipeline could assist humans in expediting acute aortic dissection management when integrated into clinical workflows.

A Modified Switching Procedure from Temporary to Tunneled Central Venous Dialysis Catheters.

Background: Tunneled central venous catheters are commonly used for dialysis in patients without a functional permanent vascular access. In an emergent setting, a non-tunneled, temporary central venous catheter is often placed for immediate dialysis. The most critical step in the catheter insertion is venipuncture, which is often a major cause for longer intervention times and procedure-related adverse events. To avoid this critical step when placing a more permanent tunneled catheter, an exchange over a previously placed temporary one can be considered. In this paper, we present a modified switching approach with a separate access site. Methods: In this retrospective analysis of a prospective database, we examined whether this modified technique is non-inferior to a de novo application. Therefore, we included all 396 patients who received their first tunneled dialysis catheter at our site from March 2018 to March 2023. Out of these, 143 patients received the modified approach and 253 the standard de novo ultrasound-guided puncture and insertion. Then, the outcomes of the two groups, including adverse events and infections, were compared by nonparametric tests and multivariable logistic regression. Results: In both groups, the implantations were 100% successful. Catheter explantation due to infection according to CDC criteria was necessary in 18 cases, with no difference between the groups (5.0% vs. 4.4% p = 0.80). The infection rate per 100 days was 0.113 vs. 0.106 in the control group, with a comparable spectrum of bacteria. A total of 12 catheters (3 vs. 9) had to be removed due to a periinterventional complication. An early-onset infection was the reason in two cases (1.3%) in the study group and five in the control group (1.9%). A total misplacement of the catheter occurred in two cases only in the control group. After adjustment for potential confounders via multivariable logistic regression there was not a significant difference in the complication rate (adjusted odds ratio, aOR = 0.53, 95% CI = 0.14-2.03, p = 0.351) but an estimated decreased risk overall based on the average treatment effect of -1.7% in favor of the study group. Conclusions: The present study shows that a catheter exchange leads to no more infections than a de novo placement; hence, it is a feasible method. Moreover, misplacements and control chest X-rays to exclude pneumothorax after venipuncture were completely avoided by exchanging. This approach yields a much lower infection rate than previous reports: 1.3% compared to 2.7% in all existing aggregated studies. The presented approach seems to be superior to existing switching methods. Overall, an exchange can also help to preserve veins for future access, since the same jugular vein is used.

The impact of class I compression stockings on the peripheral microperfusion of the lower limb: A prospective pilot study.

OBJECTIVE: The use of medical compression stockings (MCS) in patients with peripheral arterial disease (PAD) and diabetes is the subject of an ongoing critical debate. While reducing leg edema of various origins by improving venous back flow, there is a concern about additional arterial flow obstruction when compression therapy is applied in pre-existing PAD. The aim of this study is to obtain further information on the use of class I MCS in patients with advanced PAD and to evaluate the framework conditions for a safe application. METHODS: The total collective (n = 55) of this prospective, clinical cohort study consisted of 24 patients with PAD Fontaine stage IIb and higher studied before revascularization, of whom 16 patients were examined again after revascularization, and 15 healthy participants included for reference. The microperfusion of the lower extremity of all participants was examined in a supine, elevated, and sitting position using the oxygen to see (O2C) method. RESULTS: The results indicate that leg positioning had the strongest influence on microcirculation (SO2 and flow: p = 0.0001), whereas MCS had no significant effect on the perfusion parameters (SO2: p = 0.9936; flow: p = 0.4967) and did not lead to a deterioration of values into critical ranges. CONCLUSION: Mild medical compression therapy appears to be feasible even in patients with advanced PAD. Larger studies are warranted to observe any long-term effects, in particular for the treatment of reperfusion edema after revascularization.

Ureterovesical Anastomosis Complications in Kidney Transplantation: Definition, Risk Factor Analysis, and Prediction by Quantitative Fluorescence Angiography with Indocyanine Green.

Ureteral stenosis and urinary leakage are relevant problems after kidney transplantation. A standardized definition of ureterovesical anastomosis complications after kidney transplantation has not yet been established. This study was designed to demonstrate the predictive power of quantitative indocyanine green (ICG) fluorescence angiography. This bicentric historic cohort study, conducted between November 2015 and December 2019, included 196 kidney transplantations. The associations between quantitative perfusion parameters of near-infrared fluorescence angiography with ICG and the occurrence of different grades of ureterovesical anastomosis complications in the context of donor, recipient, periprocedural, and postoperative characteristics were evaluated. Post-transplant ureterovesical anastomosis complications occurred in 18%. Complications were defined and graded into three categories. They were associated with the time on dialysis (p = 0.0025), the type of donation (p = 0.0404), and the number of postoperative dialysis sessions (p = 0.0173). Median ICG ingress at the proximal ureteral third was 14.00 (5.00-33.00) AU in patients with and 23.50 (4.00-117.00) AU in patients without complications (p = 0.0001, cutoff: 16 AU, sensitivity 70%, specificity 70%, AUC = 0.725, p = 0.0011). The proposed definition and grading of post-transplant ureterovesical anastomosis complications is intended to enable valid comparisons between studies. ICG Fluorescence angiography allows intraoperative quantitative assessment of ureteral microperfusion during kidney transplantation and is able to predict the incidence of ureterovesical anastomosis complications. Registration number: NCT-02775838.

Investigation of Different Methods of Intraoperative Graft Perfusion Assessment during Kidney Transplantation for the Prediction of Delayed Graft Function: A Prospective Pilot Trial.

Delayed graft function (DGF) after renal transplantation is a relevant clinical problem affecting long-term organ function. The early detection of patients at risk is crucial for postoperative monitoring and treatment algorithms. In this prospective cohort study, allograft perfusion was evaluated intraoperatively in 26 kidney recipients by visual and formal perfusion assessment, duplex sonography, and quantitative microperfusion assessment using O2C spectrometry and ICG fluorescence angiography. The O2C tissue spectrometry device provides a quantitative method of microperfusion assessment that can be employed during kidney transplantation as an easy-to-use and highly sensitive alternative to ICG fluorescence angiography. Intraoperative microvascular flow and velocity in the allograft cortex after reperfusion predicted DGF with a sensitivity of 100% and a specificity of 82%. Threshold values of 57 A.U. for microvascular flow and 13 A.U. for microvascular velocity were identified by an ROC analysis. This study, therefore, confirmed that impairment of microperfusion of the allograft cortex directly after reperfusion was a key indicator for the occurrence of DGF after kidney transplantation. Our results support the combined use of intraoperative duplex sonography, for macrovascular quality control, and quantitative microperfusion assessment, such as O2C spectrometry, for individual risk stratification to guide subsequent postoperative management.

Intra- and Extrathoracic Malignant Tracheoesophageal Fistula-A Differentiated Reconstructive Algorithm.

BACKGROUND: Tracheoesophageal fistulae (TEF) after oncologic resections and multimodal treatment are life-threatening and surgically challenging. Radiation and prior procedures hamper wound healing and lead to high complication rates. We present an interdisciplinary algorithm for the treatment of TEF derived from the therapy of consecutive patients. PATIENTS AND METHODS: 18 patients (3 females, 15 males) treated for TEF from January 2015 to July 2017 were included. Two patients were treated palliatively, whereas reconstructions were attempted in 16 cases undergoing 24 procedures. Discontinuity resection and secondary gastric pull-up were performed in two patients. Pedicled reconstructions were pectoralis major (n = 2), sternocleidomastoid muscle (n = 2), latissimus dorsi (n = 1) or intercostal muscle (ICM, n = 7) flaps. Free flaps were anterolateral thigh (ALT, n = 4), combined anterolateral thigh/anteromedial thigh (ALT/AMT, n = 1), jejunum (n = 3) or combined ALT-jejunum flaps (n = 2). RESULTS: Regarding all 18 patients, 11 of 16 reconstructive attempts were primarily successful (61%), whereas long-term success after multiple procedures was possible in 83% (n = 15). The 30-day survival was 89%. Derived from the experience, patients were divided into three subgroups (extrathoracic, cervicothoracic, intrathroracic TEF) and a treatment algorithm was developed. Primary reconstructions for extra- and cervicothoracic TEF were pedicled flaps, whereas free flaps were used in recurrent or persistent cases. Pedicled ICM flaps were mostly used for intrathoracic TEF. CONCLUSION: TEF after multimodal tumor treatment require concerted interdisciplinary efforts for successful reconstruction. We describe a differentiated reconstructive approach including multiple reconstructive techniques from pedicled to chimeric ALT/jejunum flaps. Hereby, successful reconstructions are mostly possible. However, disease and patient-specific morbidity has to be anticipated and requires further interdisciplinary management.

Application of Fluorescent Dyes in Visceral Surgery: State of the Art and Future Perspectives.

BACKGROUND: Through the improvement and implementation of advanced intraoperative imaging, the indications for intraoperative fluorescence have spread to various fields of visceral surgery. Indocyanine green (ICG)-based fluorescence angiography and the imaging systems using this certain dye are currently the cornerstone of intraoperative, fluorescence-based medical imaging. SUMMARY: The article focuses on principles and approaches of intraoperative fluorescence in general surgery. The current clinical practice of intraoperative fluorescence and its evidence are described. Emerging new fields of application are put in a perspective. Furthermore, the technique and possible pit-falls in the performance of intraoperative ICG fluorescence angiography are described in this review article. KEY MESSAGES: Overall growing evidence suggests that intraoperative fluorescence imaging delivers valuable additional information to the surgeon, which might help to perform surgery more exactly and reduce perioperative complications. Perfusion assessment can be a helpful tool when performing critical anastomoses. There is evidence from prospective and randomized trials for the benefit of intraoperative ICG fluorescence angiography during esophageal reconstruction, colorectal surgery, and surgery for mesenteric ischemia. Most studies suggest the administration of 2.5-10 mg of ICG. Standardized settings and documentation are essential. The benefit of ICG fluorescence imaging for gastrointestinal sentinel node detection and detection of liver tumors and colorectal metastases of the liver cannot clearly be estimated duo to the small number of prospective studies. Critical points in the use of intraoperative fluorescence imaging remain the low standardization and reproducibility of the results and the associated difficulty in comparing the results of the existing trials. Furthermore, little is known about the influence of hemodynamic parameters on the quantitative assessment of ICG fluorescence during surgery.

Indocyanine Green Tissue Angiography Can Reduce Extended Bowel Resections in Acute Mesenteric Ischemia.

PURPOSE: Surgical exploration and bowel resection are frequently required for treating non-occlusive mesenteric ischemia. Intraoperative evaluation of intestinal perfusion is subjective and challenging. In this feasibility study, ICG fluorescence angiography was performed in order to evaluate intestinal perfusion in patients with acute mesenteric ischemia. METHODS: This is a retrospective analysis of 52 patients who were operated for acute mesenteric ischemia using ICG fluorescence angiography. Patients with occlusive disease requiring recanalization were excluded. The SPY and PinPoint imaging systems were used for open and laparoscopic surgery, respectively. Intraoperative macroscopic assessment of perfusion was compared with the ICG angiography results. RESULTS: Surgical exploration was performed for ischemia of the colon (n = 12), the small bowel (n = 23), or both (n = 16). One patient had ischemia of the esophagus and stomach. All patients had a preoperative CT angiography to rule out stenosis or occlusion of the mesenteric vessels. In 18 cases (34.6%), ICG fluorescence angiography provided information that was supplemental to macroscopic evaluation, but most patients did not survive the postoperative course. However, in six of those cases (11.5%), ICG angiography led to a major change in operative strategy resulting in a significant clinical benefit for those patients. For two cases, ICG fluorescence produced false negative results. DISCUSSION: ICG tissue angiography is feasible and technically reliable for evaluating intestinal perfusion in acute mesenteric ischemia and led to a significant clinical benefit in 11% of our patients. A relevant discrepancy between surgical visual assessment and fluorescence angiography was found in 35% of the cases, which may help to define resection margins more accurately and thus support surgical decision-making.