Charakterisierung von Lebertumoren nach kontrastverstärkter Sonographie und digitaler Graustufenbestimmung

Charakterisierung von Lebertumoren nach kontrastverstärkter Sonographie und digitaler Graustufenbestimmung Ziel: Die Charakterisierung fokaler Leberläsionen ist Bestandteil des klinischen Alltags und für Patienten von therapeutischer und prognostischer Relevanz. Auf diesem Gebiet wurde bisher die native Sonographie regulär eingesetzt. Eine sichere Artdiagnose bei unklaren Lebertumoren ist jedoch nur selten möglich. Die Einführung der kontrastmittelverstärkten Sonographie hat die differentialdiagnostischen Optionen erweitert. Ziel dieser Studie war es, den Nutzen des kontrastmittelverstärkten Ultraschalls und der anschließenden digitalen Graustufenanalyse bei fokalen Leberläsionen zu bewerten. Methodik: In einer prospektiven Studie wurde bei 50 Patienten mit CT oder MRT gesicherten Lebertumoren eine Sonographie des Oberbauches in nativer Sonographie und in Phaseninversionstechnik mit intravenöser Gabe des Ultraschallkontrastmittels SonoVue® durchgeführt. Nach Kontrastmittelgabe wurden über 120 s digitale Standbilder akquiriert. Mittels Software ermittelte man den dynamischen Graustufenverlauf für jeden einzelnen Tumor. Es folgte der Vergleich der einzelnen bildgebenden Modalitäten untereinander. Ergebnisse: Der Anteil der artdiagnostisch korrekten Zuordnungen belief sich in der CT bzw. MRT auf 78% und in der nativen Sonographie auf 60%. Mit Hilfe des kontrastmittelverstärkten Ultraschalls konnte er auf 86% gesteigert werden. Die digitale Graustufenanalyse lieferte für die einzelnen Tumorentitäten charakteristische Kurvenverläufe. Hierbei erwiesen sich die Zeitpunkte 20 s und 100 s nach Kontrastmittelgabe für die artspezifische Charakterisierung und für die Differenzierung in benigne und maligne Tumoren als optimal. Schlussfolgerung: Die kontrastmittelverstärkte Sonographie und deren digitale Graustufenbestimmung bilden eine Ergänzung der bisherigen Diagnostik von Lebertumoren und ermöglichen eine bessere Charakterisierung der Herde. Dies sollte in zusätzlichen Studien evaluiert werden.Characterization of Hepatic Tumors with Contrast-enhanced Ultrasound and Digital Gray-Scale Analysis Purpose: The characterization of liver tumors is of therapeutic and prognostic relevance. Although ltrasound offers the opportunity to detect hepatic tumors, its previous techniques did not lead towards a definitve differentiation. The purpouse of this study was the evaluation of contrast enhanced ultrasound followed by quantitative digital analysis in patients with focal hepatic tumors. Materials and Methods: In a prospective stuy, 50 patients with liver tumors previously detected by CT or MRI were examined by ultrasound of the upper abdomen using conventional and phase inversion technique after intravenous application of an ultrasound contrast agent. Digital images were stored over 120 s and software powerd digital gray-scale curves were produced for each individual lesion. Results: While the percentage of tumors correctly characterised by CT/MRI amounted to 78%, the percentage increased from 60% using conventional ultrasound to 86% using contrast enhanced ultrasound including gray-scale analysis. Typical graphs were achieved for different tumor entities on digital gray-scale analysis. Time intervals at 20 and 100 seconds showed optimal for differantiation between particualar entities. Conclusion: Quantification of contrast enhanced ultrasound is an addition to the previous diagnostic procedure in hepatic tumors. It offers the possibility of an investigator-independent characterization of lesions and should be evaluated in further studies

Does Hepatic Steatosis Influence the Detection Rate of Metastases in the Hepatobiliary Phase of Gadoxetic Acid-Enhanced MRI?

The aim of this exploratory study was to evaluate the influence of hepatic steatosis on the detection rate of metastases in gadoxetic acid-enhanced liver magnetic resonance imaging (MRI). A total of 50 patients who underwent gadoxetic acid-enhanced MRI (unenhanced T1w in- and opposed-phase, T2w fat sat, unenhanced 3D-T1w fat sat and 3-phase dynamic contrast-enhanced (uDP), 3D-T1w fat sat hepatobiliary phase (HP)) were retrospectively included. Two blinded observers (O1/O2) independently assessed the images to determine the detection rate in uDP and HP. The hepatic signal fat fraction (HSFF) was determined as the relative signal intensity reduction in liver parenchyma from in- to opposed-phase images. A total of 451 liver metastases were detected (O1/O2, n = 447/411). O1/O2 detected 10.9%/9.3% of lesions exclusively in uDP and 20.2%/15.5% exclusively in HP. Lesions detected exclusively in uDP were significantly associated with a larger HSFF (area under curve (AUC) of receiver operating characteristic (ROC) analysis, 0.93; p 30%) is a potential pitfall for the detection of metastases in HP

The influence of the COVID-19 pandemic on surgical therapy and care: a cross-sectional study

Background: Due to the COVID-19 pandemic, an extensive reorganisation of healthcare resources was necessary-with a particular impact on surgical care across all disciplines. However, the direct and indirect consequences of this redistribution of resources on surgical therapy and care are largely unknown. Methods: We analysed our prospectively collected standardised digital quality management document for all surgical cases in 2020 and compared them to the years 2018 and 2019. Periods with high COVID-19 burdens were compared with the reference periods in 2018 and 2019. Results: From 2018 to 2020, 10,723 patients underwent surgical treatment at our centres. We observed a decrease in treated patients and a change in the overall patient health status. Patient age and length of hospital stay increased during the COVID-19 pandemic (p = 0.004 and p = 0.002). Furthermore, the distribution of indications for surgical treatment changed in favour of oncological cases and less elective cases such as hernia repairs (p < 0.001). Postoperative thromboembolic and pulmonary complications increased slightly during the COVID-19 pandemic. There were slight differences for postoperative overall complications according to Clavien-Dindo, with a significant increase of postoperative mortality (p = 0.01). Conclusion: During the COVID-19 pandemic we did not see an increase in the occurrence, or the severity of postoperative complications. Despite a slightly higher rate of mortality and specific complications being more prevalent, the biggest change was in indication for surgery, resulting in a higher proportion of older and sicker patients with corresponding comorbidities. Further research is warranted to analyse how this changed demographic will influence long-term patient care

Safety of transanal ileal pouch-anal anastomosis for ulcerative colitis: a retrospective observational cohort study

Background: Colectomy with transanal ileal pouch-anal anastomosis (taIPAA) is a surgical technique that can be used to treat benign colorectal disease. Ulcerative colitis is the most frequent inflammatory bowel disease (IBD) and although pharmacological therapy has improved, colectomy rates reach up to 15%. The objective of this study was to determine anastomotic leakage rates and treatment after taIPAA as well as short- and long-term pouch function. Methods: We conducted a retrospective analysis of a prospective database of all patients undergoing taIPAA at an academic tertiary referral center in Germany, between 01/03/2015 and 31/08/2019. Patients with indications other than ulcerative colitis or with adjuvant chemotherapy following colectomy for colorectal carcinoma were excluded for short- and long-term follow up due to diverging postoperative care yet considered for evaluation of anastomotic leakage. Results: A total of 22 patients undergoing taIPAA during the study time-window were included in analysis. Median age at the time of surgery was 32 +/- 12.5 (14-54) years. Two patients developed an anastomotic leakage at 11 days (early anastomotic leakage) and 9 months (late anastomotic leakage) after surgery, respectively. In both patients, pouches could be preserved with a multimodal approach. Twenty patients out of 22 met the inclusion criteria for short and long term follow-up. Data on short-term pouch function could be obtained in 14 patients and showed satisfactory pouch function with only four patients reporting intermittent incontinence at a median stool frequency of 9-10 times per day. In the long-term we observed an inflammation or "pouchitis" in 11 patients and a pouch failure in one patient. Conclusion: Postoperative complication rates in patients with benign colorectal disease remain an area of concern for surgical patient safety. In this pilot study on 22 selected patients, taIPAA was associated with two patients developing anastomotic leakage. Future large-scale validation studies are required to determine the safety and feasibility of taIPAA in patients with ulcerative colitis

Treatment of Anti-HLA Donor-Specific Antibodies Results in Increased Infectious Complications and Impairs Survival after Liver Transplantation

Donor-specific anti-human leukocyte antigen antibodies (DSA) are controversially discussed in the context of liver transplantation (LT). We investigated the relationship between the presence of DSA and the outcome after LT. All the LTs performed at our center between 1 January 2008 and 31 December 2015 were examined. Recipients < 18 years, living donor-, combined, high-urgency-, and re-transplantations were excluded. Out of 510 LTs, 113 DSA-positive cases were propensity score-matched with DSA-negative cases based on the components of the Balance of Risk score. One-, three-, and five-year survival after LT were 74.3% in DSA-positive vs. 84.8% (p = 0.053) in DSA-negative recipients, 71.8% vs. 71.5% (p = 0.821), and 69.3% vs. 64.9% (p = 0.818), respectively. Rejection therapy was more often applied to DSA-positive recipients (n = 77 (68.1%) vs. 37 (32.7%) in the control group, p < 0.001). At one year after LT, 9.7% of DSA-positive patients died due to sepsis compared to 1.8% in the DSA-negative group (p = 0.046). The remaining causes of death were comparable in both groups (cardiovascular 6.2% vs. 8.0%; p = 0.692; hepatic 3.5% vs. 2.7%, p = 0.788; malignancy 3.5% vs. 2.7%, p = 0.788). DSA seem to have an indirect effect on the outcome of adult LTs, impacting decision-making in post-transplant immunosuppression and rejection therapies and ultimately increasing mortality due to infectious complications

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

Image guided laparoscopic liver surgery in a high field open MRI

Dank moderner Schnittbildverfahren wie der kontrastmittelverstärkten MRT und CT ist es möglich, immer komplexere leberchirurgische Eingriffe zu planen und durchzuführen. Neben der hohen Sensitivität bei der Detektion kleiner Läsionen ist auch eine genaue Lokalisation in Bezug auf relevante anatomische Strukturen möglich. Diese präoperativen Bilder lassen sich darüber hinaus mittels geeigneter Software in virtuelle 3D Datensätze umwandeln und erleichtern dem Chirurgen die unmittelbare Planung der Resektionsgrenzen. Während der Operation steht dem Chirurgen jedoch lediglich der intraoperative Ultraschall als einziges etabliertes bildgebendes Verfahren zur Verfügung. Insbesondere die Unterbrechung des operativen Ablaufs und der teils komplexe mentale Transfer der zweidimensionalen Schnittbilder limitieren den Stellenwert der Sonographie. Als alternative intraoperative Visualisierungsverfahren wurden von verschiedenen Gruppen Navigationstechniken entwickelt und untersucht. Sie ermöglichen es, präoperative 3D Datensätze auf die intraoperative Situation zu übertragen. Aufgrund des Weichteilcharakters des Leberparenchyms und der Atemverschiebung des Organs kommt es mitunter zu teils deutlichen Abweichungen des Navigationsbildes von der intraoperativen Realität. Somit sind diese Techniken aktuell immer noch als experimentell zu werten und haben bisher nicht den Weg in den klinischen Alltag gefunden. Eine interessante Alternative zu den genannten Verfahren stellt die offene MRT Bildgebung dar. Im Bereich der interventionellen Radiologie wurde diese Technik bereits erfolgreich etabliert. Als intraoperatives Bildgebungsverfahren gibt es vor allem Erfahrungen im Bereich der Neurochirurgie. An einzelnen universitären Zentren wurde ein offenes MRT in den Operationssaal integriert. Durch Einführung der offenen Hochfeld MRT konnte der Zugang zum Patienten weiter verbessert werden bei gleichzeitiger Reduktion der Artefaktanfälligkeit und verbesserter Bildgebung mit schnelleren Sequenzen und einer detaillierteren Ortsauflösung. Als wesentliche Limitationen bleiben jedoch die hohen Kosten und der apparative Aufwand bestehen. Bezogen auf Operationen oder Interventionen an der Leber erlaubt die offene MRT den bekannten hohen Gewebekontrast zur Abgrenzung von Tumoren und Gefäßen vom Parenchym als auch eine multiplanare Darstellung zur besseren anatomischen Orientierung. Ziel der hier aufgeführten Studien war es die technische Machbarkeit der MRT-gestützten minimalinvasiven Leberchirurgie zu eruieren. Aufgrund der ferromagnetischen Eigenschaften der üblichen Dissektionsinstrumente waren diese für den Einsatz im MRT ungeeignet. Als ideale Alternative wurde die Laserdissektion gewertet und in zwei Versuchsreihen im Tiermodell etabliert. Hier zeigte sich der Nd:YAG Laser mit 1064 nm bei der Koagulation von Blutgefäßen, dem Blutverlust und der OP Dauer als Vorteilhaft. In einer zweiten Studie wurden unterschiedliche Zugangswege zur Leberteilresektion verglichen. Die Laparoskopie zeigte gegenüber der offenen Resektion einen reduzierten Blutverlust und geringere Adhäsionen bei einer insgesamt verlängerten Operationsdauer. Als drittes Verfahren wurde die handunterstützte Laparoskopie etabliert. Die Entwicklung optimaler Bildsequenzen für die minimalinvasive Leberchirurgie im offenen MRT war Gegenstand der nächsten Studie. Neben einer schnellen Bildfolge waren vor allem die Artefaktanfälligkeit und die Kontrastierung von Lebergefäßen gegenüber dem Parenchym wesentliche Faktoren bei der Auswahl geeigneter Sequenzen. Darüber hinaus wird die Bildqualität durch den Einsatz der Laparoskopiekamera und der dadurch ausgelösten elektromagnetischen Interferenzen reduziert. Insgesamt zeigte die T2 TSE Sequenz die besten Eigenschaften für den Einsatz der laparoskopischen Leberchirurgie im MRT. In der Studie zur experimentellen Leberteilresektion mittels MRT Bildgebung konnten wir die generelle Machbarkeit darlegen. Die zusätzlichen MRT Bilder wurden während der Operation in Echtzeit auf einem separaten Monitor angezeigt. Sie erhöhten durch die Darstellung des Lasers in Relation zu den Blutgefäßen die Orientierung des Chirurgen und führten zu einer Reduktion des Blutverlustes. In einer weiteren Arbeit wurden die Vorteile der offenen MRT im Rahmen der Nadelpositionierung zur Radiofrequenzablation mit der konventionellen Sonographie in einem Phantommodell verglichen. Die MRT- gestützte Technik zeigte vergleichbare Resultate mit dem Ultraschall bei deutlich verbesserter Tumorkontrastierung. Als weiteres Ablationsverfahren wurde die Laser-induzierte Thermotherapie im in-vitro Modell im offenen Hochfeld MRT evaluiert. Als wesentlicher Vorteil der Methode gilt die MR Thermometrie zur unmittelbaren Therapiekontrolle. Die Ergebnisse der aufgeführten Arbeiten zeigen das Potential MRT-gestützter Chirurgie und Interventionen an der Leber. Als wesentliche Limitationen sind die ergonomisch eingeschränkten Verhältnisse und der komplexe und zeitintensive Arbeitsablauf zu nennen. Durch weitere Entwicklungen wie Beispielsweise die Etablierung von zusätzlichen Trackingtechnologien zur automatischen Anpassung der Schnittbildebenen an das Instrumentarium ließe sich der Operationsablauf weiter optimieren. Insgesamt stellt die offene Hochfeld MRT eine zukunftsträchtige Technologie dar, welche im interdisziplinären Austausch zwischen Radiologie und Chirurgie die Möglichkeit zur Entwicklung klinisch relevanter Verfahren bietet.The increasing quantity and complexity of laparoscopic liver resections addresses the need for improved intraoperative imaging tools. Especially in difficult cases with complex tumor localization intraoperative visualization of liver vessels and tumor margins is essential for an adequate resection and reduction of surgery associated risks. At present the surgeon relies on a mental transfer of preoperative images and intraoperative ultrasound. As an alternative imaging modality open MRIs have been evaluated and clinically implemented for various interventional and surgical procedures. We established an animal model for MR-guided minimal invasive liver resections in an open high field MRI. In order to realize laparoscopic liver surgery under MR- guidance we developed and applied a MR-compatible endoscopy unit. In previous experiments suitable MR sequences have been tested and identified. The Nd:YAG laser was considered as an ideal dissection tool regarding its non- ferromagnetic character resulting in a major reduction of image artifacts compared to conventional devices. Main advantages of MR-guidance encompass high soft tissue contrast, real time imaging during the intervention and multiplanar visualization of vessels and tumors. MR guided liver resection is feasible providing additional image information to the surgeon. We conclude that MR guided laparoscopic liver resection improves the anatomical orientation and may increase the safety of future minimal invasive liver surgery. Furthermore we evaluated MR guided laparoscopic radiofrequency ablation and laser induced thermotherapy

Pressure Measurement Techniques for Abdominal Hypertension: Conclusions from an Experimental Model

Introduction. Intra-abdominal pressure (IAP) measurement is an indispensable tool for the diagnosis of abdominal hypertension. Different techniques have been described in the literature and applied in the clinical setting. Methods. A porcine model was created to simulate an abdominal compartment syndrome ranging from baseline IAP to 30 mmHg. Three different measurement techniques were applied, comprising telemetric piezoresistive probes at two different sites (epigastric and pelvic) for direct pressure measurement and intragastric and intravesical probes for indirect measurement. Results. The mean difference between the invasive IAP measurements using telemetric pressure probes and the IVP measurements was −0.58 mmHg. The bias between the invasive IAP measurements and the IGP measurements was 3.8 mmHg. Compared to the realistic results of the intraperitoneal and intravesical measurements, the intragastric data showed a strong tendency towards decreased values. The hydrostatic character of the IAP was eliminated at high-pressure levels. Conclusion. We conclude that intragastric pressure measurement is potentially hazardous and might lead to inaccurately low intra-abdominal pressure values. This may result in missed diagnosis of elevated abdominal pressure or even ACS. The intravesical measurements showed the most accurate values during baseline pressure and both high-pressure plateaus

Pressure Measurement Techniques for Abdominal Hypertension: Conclusions from an Experimental Model

Introduction. Intra-abdominal pressure (IAP) measurement is an indispensable tool for the diagnosis of abdominal hypertension. Different techniques have been described in the literature and applied in the clinical setting. Methods. A porcine model was created to simulate an abdominal compartment syndrome ranging from baseline IAP to 30 mmHg. Three different measurement techniques were applied, comprising telemetric piezoresistive probes at two different sites (epigastric and pelvic) for direct pressure measurement and intragastric and intravesical probes for indirect measurement. Results. The mean difference between the invasive IAP measurements using telemetric pressure probes and the IVP measurements was −0.58 mmHg. The bias between the invasive IAP measurements and the IGP measurements was 3.8 mmHg. Compared to the realistic results of the intraperitoneal and intravesical measurements, the intragastric data showed a strong tendency towards decreased values. The hydrostatic character of the IAP was eliminated at high-pressure levels. Conclusion. We conclude that intragastric pressure measurement is potentially hazardous and might lead to inaccurately low intra-abdominal pressure values. This may result in missed diagnosis of elevated abdominal pressure or even ACS. The intravesical measurements showed the most accurate values during baseline pressure and both high-pressure plateaus