Ulrich Rother

Cracking the perfusion code?: Laser-assisted Indocyanine Green angiography and combined laser Doppler spectrophotometry for intraoperative evaluation of tissue perfusion in autologous breast reconstruction with DIEP or ms-TRAM flaps

The aim of this prospective study was to assess the correlation of flap perfusion analysis based on laser-assisted Indocyanine Green (ICG) angiography with combined laser Doppler spectrophotometry in autologous breast reconstruction using free DIEP/ms-TRAM flaps. Between February 2014 and July 2015, 35 free DIEP/ms-TRAM flaps were included in this study. Besides the clinical evaluation of flaps, intraoperative perfusion dynamics were assessed by means of laser-assisted ICG angiography and post-capillary oxygen saturation and relative haemoglobin content (rHb) using combined laser Doppler spectrophotometry. Correlation of the aforementioned parameters was analysed, as well as the impact on flap design and postoperative complications. Flap survival rate was 100%. There were no partial flap losses. In three cases, flap design was based on the angiography, contrary to clinical evaluation and spectrophotometry. The final decision on the inclusion of flap areas was based on the angiographic perfusion pattern. Angiography and spectrophotometry showed a correlation in most of the cases regarding tissue perfusion, post-capillary oxygen saturation and relative haemoglobin content. Laser-assisted ICG angiography is a useful tool for intraoperative evaluation of flap perfusion in autologous breast reconstruction with DIEP/ms-TRAM flaps, especially in decision making in cases where flap perfusion is not clearly assessable by clinical signs and exact determination of well-perfused flap margins is difficult to obtain. It provides an objective real-time analysis of flap perfusion, with high sensitivity for the detection of poorly perfused flap areas. Concerning the topographical mapping of well-perfused flap areas, laser-assisted angiography is superior to combined laser Doppler spectrophotometry.

The Angiosome Concept Evaluated on the Basis of Microperfusion in Critical Limb Ischemia Patients-an Oxygen to See Guided Study.

Aim of this clinical study was to evaluate the angiosome concept with regard to the microcirculation of the foot in patients with CLI and to evaluate its relevance by means of combined laser Doppler flowmetrie and white‐light tissue spectrophotometry.

Immediate changes of angiosome perfusion during tibial angioplasty.

Objective: In recent years, a controversial discussion about the clinical relevance of the angiosome concept during tibial angioplasty has developed. Therefore, we conducted a prospective study to evaluate the angiosome concept on the level of microcirculation during tibial vascular interventions. Methods: Thirty patients with isolated tibial angioplasty were examined prospectively. Macrocirculation was evaluated by measurement of the ankle‐brachial index (ABI). For the assessment of microcirculation, a combined method of laser Doppler flowmetry and tissue spectrometry (O2C; LEA Medizintechnik GmbH, Giessen, Germany) was applied. Microcirculatory parameters were measured continuously during the procedures. Measuring points were located over different angiosomes of the index foot; a control probe was placed on the contralateral leg. Results: Cumulated microcirculation parameters (sO2, flow) as well as the ABI showed a significant improvement postinterventionally (ABI, P < .001; sO2, P < .001; flow, P < .001). Assessment of the separate angiosomes of the index leg and the comparison of the directly revascularized (DR) and indirectly revascularized (IR) angiosomes showed no significant difference concerning the microperfusion postinterventionally (DR − IR: sO2, P = .399; flow, P = .909) as well as during angioplasty. Even a further subdivision of the collective into patients with diabetes (sO2, P = .445; flow, P =.758) and renal insufficiency (sO2, P = .246; flow, P = .691) could not demonstrate a superiority of the direct revascularization at the level of microcirculation in these patients (comparison DR − IR). Conclusions: There is a significant overall improvement in tissue perfusion of the foot immediately after tibial angioplasty. The effect shown in this study, however, was found to be global and was not restricted to certain borders, such as defined by angiosomes.

Time‐extended local rtPA infiltration for acutely thrombosed hemodialysis fistulas

Introduction: This study describes results of a modified local thrombolysis technique for acutely thrombosed hemodialysis (HD) arteriovenous fistulas (AVF), which is characterized by prolonged recombinant tissue plasminogen activator (rtPA) local exposure times. Contrary to the standard lyse‐ and‐ wait (L&W) technique with local reaction times of 20–40 minutes, the modified protocol allows timing of challenging angioplasty maneuvers to the next regular working day.

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

Sufficient blood supply is a crucial factor determining postoperative allograft function in kidney transplantation. Therefore, besides the surgeons individual impression, a method for evaluating the quality of the organs 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.

Surgeon experience affects outcome of forearm arteriovenous fistulae more than outcomes of upper-arm fistulae

Introduction There is still an ongoing discussion about the influence of vascular surgeon experience on the immediate and long-term outcome of newly created arteriovenous fistula (AVF) for patients on hemodialysis (HD). The aim of this study was to compare failure and patency rates of AVF between experienced consultants and resident trainees with special focus on location of the anastomosis on the forearm or upper arm. Methods Between November 2012 and September 2016, 159 patients (83 on HD and 76 preemptive) received an AVF (90 radiocephalic [RCAVF] on the forearm; 69 brachiocephalic [BCAVF] in the elbow) by two experienced vascular surgeons (group A; n = 74) or five residents in training with one-to-four years of experience (group B; n = 85). We compared the two groups for demographic and treatment data, immediate failures (IF), bleeding complications and patency rates. Results There were no significant differences in demographic data between the two groups. Vessel diameters were significantly lower for forearm compared to upper arm arteries (p = 0.026) and veins (p = 0.05). There was a significantly increased risk for IF in group B for RCAVF (p = 0.003), but not for BCAVF (p = 1.000). Furthermore, the cumulative primary patency was reduced in group B for RCAVF (p<0.001), but not for BCAVF (p = 0.899). Conclusion Surgeon experience seems to have more influence on the immediate and long-term outcome of newly created forearm AVF compared to those located on the upper arm.

Open Versus Endovascular Revascularization of Below-Knee Arteries in Patients With End-Stage Renal Disease and Critical Limb Ischemia

Background: Evaluation of below-the-knee open revascularization (OR) versus endovascular revascularization (EVT) in patients with end-stage renal disease and critical limb ischemia (CLI) was performed. Patients and Methods: Seventy-seven dialysis patients with CLI and infrapopliteal involvement from 2007 to 2017 were included. Thirty-five patients received OR and 42 patients were treated with EVT. Survival, amputation-free survival (AFS) and wound-healing were evaluated. Furthermore, both groups were analyzed for differences as to anatomic (lesion length, runoff, pedal arch classification) and clinical (VSG risk score, WIfI score) characteristics. Results: Amputation-free survival (1-year AFS: OR 54.5% vs 47.6% in EVT, 2-year AFS OR 38.3% vs 23.9% EVT, P = .201) did not significantly differ between OR and EVT nor did the wound healing rate (29% OR vs 31% EVT, P = .532). Overall survival was noticeably poor (1-year survival: 66.7% in OR and 49% in EVT, 2-year survival OR 47.4% vs EVT 27.7%; P = .088); evaluation of peripheral runoff (Rutherford score 6.9 OR vs 7.1 EVT, P = .499) and pedal arch classification as well as WIfI or VSG risk score (9.8 OR vs 9.6 EVT, P = .673) could not detect significant differences as to both the groups. Treated median lesion length was significantly increased in OR patients (OR 26 cm vs EVT 7 cm, P < .001), whereas the incidence of major adverse cardiac events was higher in EVT patients (67% in EVT vs 40% OR, P = .023). Conclusion: OR and EVT showed comparable outcomes as to AFS and wound healing. Poor overall survival remains the determining factor in patients with ESRD having CLI. Both groups differ in terms of anatomic features as lesion length and severity of comorbidities; considering the comparable long-term outcomes, decision-making should be based on these premises; individually applied, each method can contribute to limb salvage, although the overall survival remains limited.

MRI to investigate iliac artery wall thickness in triathletes

ABSTRACT Objectives: Endofibrosis was first described in endurance athletes. This rare disease is characterized by intimal hyperplasia of iliac arteries. Due to non-specific symptoms diagnosing could be very challenging and delayed. This represents a serious problem not only for affected athletes but also for consulting physicians. The aim of this study was to analyze intimal thickness of iliac arteries using non-contrast magnetic resonance imaging (MRI) in competitive triathletes suffering from exercise induced leg pain consistent with symptoms caused by endofibrosis. Methods: 18 highly trained triathletes (16 triathletes, 12 male) with a mean age of 45.4 ± 10.2 years were investigated by non-contrast MRI. We divided subjects into two groups: 10 complaint about exercise- induced leg pain and 7 were free of any symptoms. In all 10 symptomatic athletes consulting physicians excluded musculoskeletal or neurological disorders before and we suspected endofibrosis. One patient was excluded from statistical analysis due to a known recurrent external iliac artery (EIA) occlusion after surgical repair 6 month ago. Results: Mean wall thickness (T) of all 17 subjects was 1.34 ± 0.11mm for the common iliac artery (CIA) and 1.74 ± 0.18mm for the EIA. We found no significant differences by comparing T of symptomatic (s) and asymptomatic (a) legs. There were no significant differences in mean ratio of patent artery to whole artery between the symptomatic and asymptomatic legs for the CIA (0.81 vs 0.82, p = 0.87) and for the EIA (0.71 vs 0.72, p = 0.78). MRI shows a thickening of the left EIA (4.41mm) in the patient who suffered from recurrent occlusion of the left EIA and after surgical repair and histological examination confirmed an endofibrotic lesion. Conclusion: Non-contrast MRI seems to be an appropriate diagnostic tool to exclude endofibrosis in triathletes, but it cannot be recommended as initial screening modality for athletes suffering from exercise-induced leg pain.

FT03. Free Flap Autonomy After Combined Defect Reconstruction Using Arteriovenous Loop and Free Tissue Transfer

ACS, Acute coronary syndrome; AECOPD, acute exacerbation of chronic obstructive pulmonary disease; CIN, contrast-induced nephropathy; CKD, chronic kidney disease; CRI, chronic renal insufficiency; CVA, cerebrovascular accident; DEB, drug-eluting balloon; ESR, erythrocyte sedimentation rate; MACE, major adverse cardiovascular event; MALE, major adverse limb event; MET, metabolic equivalent; WIfI, Wound, Ischemia, and foot Infection.Categorical variables are presented as No. (%).

Pilot study using intraoperative fluorescence angiography during arteriovenous hemodialysis access surgery

Introduction: In this pilot study, we used indocyanine green fluorescence angiography during hemodialysis access surgery. The aim was to evaluate its relevance as a diagnostic tool to visualize changes in hand microperfusion. Patients and methods: In this prospective single-center study, 47 adult patients (33 male, 14 female) with renal disease (24 preemptive, 23 endstage) were enrolled. Surgical creation of an arteriovenous fistula was performed (22 forearm, 25 upper arm). Microperfusion of the ipsilateral hand and fingers was evaluated intraoperatively using indocyanine green fluorescence angiography. We compared the cumulated microperfusion parameters ingress (In) and ingress rate (InR) before and after opening of the anastomosis. To compare the dimension of microcirculatory decline, we calculated the ratios of the parameters (RatioIn and RatioInR) after to those before anastomosis opening. Results: The cumulated microperfusion parameters In and InR showed a significant decrease after completion of anastomosis and declamping. This effect has been seen in all patients for the hand and for each finger consecutively. During follow-up (mean 4.6, range 3–11 months), 5 patients (10.6%) complained about hemodialysis access–induced distal ischemia. The ratio of intraoperative microperfusion in those five hemodialysis access–induced ischemia patients was significantly lower compared to asymptomatic patients (RatioIn 0.23 vs 0.58, p = 0.001, and RatioInR 0.25 vs 0.62, p = 0.003). Conclusion: Intraoperative fluorescence angiography could visualize the deterioration of ipsilateral hand microperfusion after surgical creation of an arteriovenous fistula. It seems to be a promising tool to detect patients at risk for hemodialysis access–induced distal ischemia early in the peri- or even intraoperative stage.