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Background Preoperative ultrasound (US)-guided perforator mapping has immensely simplified perforator flap planning. It may be executed by the microsurgeon. Device settings and selection of ultrasound modes are of utmost significance for detection of low-flow microvessels. The following study evaluates different US modes. Methods A prospective complete data acquisition was performed from July 2018 to June 2019 in a subset of patients who underwent US-guided flap planning. Multifrequency linear transducers were used applying five US modes. Brightness (B)-mode, color flow (CF), power Doppler (PD), pulse wave (PW), and B-flow modes were evaluated regarding applicability by microsurgeons. Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were chosen to evaluate flow characteristics. US results were correlated to intraoperative findings. Results A total number of eight patients (six males and two females) undergoing anterolateral thigh (ALT) or superficial circumflex iliac artery perforator (SCIP) flap surgery received an extensive standardized US-guided perforator characterization. Qualitative evaluation was performed in B-mode, color-coded duplex sonography (CCDS), PD, and B-flow mode. Quantitative assessment was executed using PW-mode and CCDS measuring the microvessels' diameter (mm) and flow characteristics (PSV, EDV, and RI). CCDS provided a mean diameter of 1.93 mm (range: 1.2–2.8 ± 0.51), a mean systolic peak of 16.9 cm/s (range: 9.9–33.4 ± 7.79), and mean RI of 0.71 (range: 0.55–0.87 ± 0.09) for lower limb perforators. All perforators located with US were verified by intraoperative findings. An optimized, time-effective US mapping algorithm was derived. Qualitative parameters may be evaluated with B-mode, CF, or B-flow. Smallest microvessels may be assessed in PD-mode. Lowering pulse-repetition frequency (PRF)/scale is mandatory to image low-flow microvessels as perforators. Quantitative information may be obtained using PW-mode and the distance-measuring tool in CF-mode. Image and video materials are provided. Conclusion CCDS proved to be a powerful tool for preoperative perforator characterization when using a structured approach and mapping algorithm. Different techniques may be applied for specific visualizations and performed by the microsurgeon.

Purpose Assessment of intraoperative quantitative shear wave elastography (SWE) and contrast-enhanced ultrasound (CEUS) for the characterization of focal liver lesions (FLLs) during liver surgery using postoperative histopathological results as the gold standard. Materials and Methods US data of 79 consecutive patients with 98 FLLs who underwent liver surgery between 08/2015 – 06/2017 were prospectively acquired and retrospectively analyzed. Multifrequency linear/T-shaped probes (6 – 9 MHz) were used to store cine loops of at least 5 s and images of B-mode, SWE and CEUS. The first CEUS loop was continuously documented over 1 min. in each case. Quantitative SWE analysis of FLLs was performed by placing 5 regions of interest to measure shear wave speed (m/s) and stiffness (kPa). CEUS was evaluated during the arterial, portal venous and late phase after i. v. bolus injections of 2.4 – 10 ml sulfur hexafluoride microbubbles. Postoperative histopathology after tumor resection or intraoperative biopsy was obtained to confirm findings of SWE and CEUS. Results Of 98 FLLs in 79 patients (mean age: 58 years sd ± 12y) 88 were malignant and 10 were benign ranging from 0.69 to 15.2 cm in size (mean: 2.8 cm, sd ± 2.25 cm). SWE characterized 73/88 FLLs correctly as malignant and 7/10 as benign using a cut-off value of 2.5 m/s/21.3 kPa (p < 0.0005). The sensitivity was 83 %, specificity 70 %, accuracy 82 %. CEUS could correctly identify 86/88 malignant and 8/10 benign FLLs. The sensitivity was 98 %, specificity 80 %, accuracy 96 %. SWE could correctly identify 2 malignant FLLs which CEUS falsely characterized as benign. Conclusion Intraoperative CEUS and SWE are excellent tools for the highly accurate visualization, characterization and malignancy assessment of hepatic tumors during liver surgery.

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Background: Color-coded duplex sonography (CCDS) is useful for perforator flap design showing the highest sensitivity in identifying microvessels. This prospective study evaluates the feasibility of different ultrasound (US) modes applied by the microsurgeon in daily practice suggesting quantifiable reference values. Methods: Twenty-four patients aged between 17 and 68 years (mean 43.3 ± 14.2 years) with 18 anterolateral thigh (ALT) and 6 superficial circumflex iliac artery (SCIP) flaps were included. Indications were traumatic (n = 12), infectious (n = 6), ischemic (n = 4), or tumor-associated defects (n = 2). Different US modes were evaluated regarding applicability using multifrequency linear probes (5-15 MHz). Vessels diameter, peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were measured. Preoperative results were correlated to intraoperative findings. Results: In the examined patient group with 24 perforator flaps a 100% correlation

ABSTR AC TPurpose To evaluate the diagnostic significance of preoperatively and intraoperatively performed contrast-enhanced ultrasound (CEUS/IOCEUS) in the diagnosis of liver tumors in comparison to magnetic resonance imaging (MRI) and histopathology. Materials and Methods Retrospective analysis of 70/317patients who underwent surgery for liver tumors between January 2012 and October 2015. Findings of CEUS and IO-CEUS were compared to MRI. CEUS and IOCEUS were performed using multifrequency linear probes (1 -5, 6 -15 MHz) after bolus injection of 1 -5 ml sulfur hexafluoride microbubbles. The histopathology after surgical resection, MRI morphology (T1, T2, VIBE, diffusion sequences) and wash-in/wash-out kinetics of CEUS were evaluated.Results In 70 analyzed patient cases, 64 malignant liver lesions could be detected. 6 patients had benign liver lesions. Among the 64 malignant lesions, there were 28 metastases, 24 hepatocellular carcinomas (HCC), 9 cholangiocellular carcinomas (CCC) and 3 gallbladder carcinomas. 2 of the 6 benign liver lesions were hemangiomas, 2 were adenomas, 1 was an FNH and 1 was a complicated cyst. There was no significant difference when determining the lesion's malignancy/ benignity (p = 1.000). Furthermore, there was no statistical significance between preoperative CEUS and MRI regarding the general differential diagnosis of a tumor (p = 0.210) and the differential diagnosis classification between HCCs (p = 0.453) and metastases (p = 0.250). There was no statistical significance in tumor size (10 mm -151 mm; mean 49 mm SD +/-31 mm) and location (tumor size p = 0.579; allocation to liver lobes p = 0.132; segment diagnosis p = 0.121) between preoperatively performed CEUS and MRI. The combination of preoperative MRI and CEUS for lesion detection showed significant differences compared to CEUS or MRI only (p < 0.001 for CEUS; p = 0.004 for MRI). IOCEUS offered the substantial advantage of locating additional liver lesions (p = 0.004 compared to preoperative MRI, p = 0.002 compared to preoperative CEUS). In 10/37 cases (27 %) IOCEUS could locate further liver lesions which had not been identified during CEUS and/or MRI preoperatively, so that operative therapy was adapted accordingly and resection was extended if necessary. Schlussfolgerung CEUS erweist sich in der präoperativen Diagnostik von Lebertumoren als eine dynamische Bildgebung mit hoher diagnostischer Aussagekraft über die Tumormikrovaskularisierung und ist somit hilfreich zur Bewertung von Tumorentität und Tumorgröße von Lebertumoren. Intraoperativ kommt CEUS eine wesentliche Bedeutung in der operativen Therapieentscheidung zu.

ABSTR AC TPurpose To determine the value of routine contrast enema of loop ileostomy before elective ileostomy closure regarding the influence on the clinical decision-making. Materials and MethodsRetrospective analysis of contrast enemas at a tertiary care center between 2005 und 2011. Patients were divided into two groups: Group I with ileostomy reversal, group II without ileostomy closure. Patient-related parameters (underlying disease, operation method) and parameters based on the findings (stenosis, leakage of anastomosis, incontinence) were evaluated.Results Analyzing a total of 252 patients in 89 % (group I, n = 225) ileostomy closure was performed. In 15 % the radiologic report was the only diagnostic modality needed for therapy decision; in 36 % the contrast enema and one or more other diagnostic methods were decisive. In 36 % the radiological report of the contrast imaging was not relevant for decision at all. In 11 % (group II, n = 27) no ileostomy closure was performed. In this group in 11 % the radiological report of the contrast enema was the only decision factor for not performing the ileostomy reversal. In 26 % one or more examination was necessary. In 26 % the result of the contrast examination was not relevant. ConclusionThe radiologic contrast imaging of loop ileostomy solely plays a minor role in complex surgical decisionmaking before planned reversal, but is important as first imaging method in detecting complications and often leads to additional examinations. This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.Ergebnisse Von den 252 untersuchten Patienten erfolgte bei 89 % (Gruppe I, n = 225) eine Rückverlagerungsoperation. Die Durchleuchtungsuntersuchung war dabei in 15 % als alleinige diagnostische Maßnahme zur Indikationsstellung ausreichend; in 36 % waren für die Entscheidung zur Rückverlage-rung weitere Zusatzuntersuchungen notwendig. Bei 36 % war der radiologische Befund irrelevant für die Therapieentscheidung. Bei 11 % (Gruppe II, n = 27) erfolge keine Rückverlage-rung. Dabei war in 19 % der radiologische Befund allein ausschlaggebend für die Ablehnung der Rückverlagerung und in 26 % war mindestens eine weitere Untersuchung nötig. In 26 % waren ausschließlich andere Untersuchungen entscheidend.

Therapy options for ruptured Achilles tendons need to take into account the right balance of timing, amount and intensity of loading to ensure a sufficient biomechanical resilience of the healing tendon on the one hand, and to enable an adequate tensile stimulus on the other hand. However, biomechanical data of human Achilles tendons after rupture during the separate healing stages are unknown. Shear wave elastography is an ultrasound technique that measures material elastic properties non-invasively, and was proven to have a very good correlation to biomechanical studies. Taking advantage of this technology, 12 patients who suffered from an acute Achilles tendon rupture were acquired and monitored through the course of one year after rupture. Nine of these patients were treated non-operatively and were included for the analysis of biomechanical behaviour. A significant increase of material elastic properties was observed within the first six weeks after trauma (up to 80% of baseline value), where it reached a plateau phase. A second significant increase occurred three to six months after injury. This pilot study suggests a time correlation of biomechanical properties with the biological healing phases of tendon tissue. In the reparative phase, a substantial amount of biomechanical resilience is restored already, but the final stage of biomechanical stability is reached in the maturation phase. These findings can potentially be implemented into treatment and aftercare protocols.