A. Bunk

Quantitative Perfusion Analysis of Transabdominal Contrast-Enhanced Ultrasonography of Pancreatic Masses and Carcinomas

BACKGROUND & AIMS Preoperative differential diagnosis of pancreatic ductal adenocarcinoma (PDAC) and focal masses in patients with chronic pancreatitis (CP) can be challenging. There are fine differences in the vascularization of these lesions; ultrasound contrast agents can aid in their differentiation. We evaluated the value of software-aided quantitative analysis of transabdominal contrast-enhanced ultrasonography for differential diagnosis of PDAC vs focal masses. METHODS Sixty patients for whom it was not possible to differentiate between an inflammatory focal lesion of the pancreas and a pancreatic carcinoma underwent contrast-enhanced ultrasonography with a second-generation contrast agent. Time-intensity curves were obtained for all exams in 2 regions of interest within the lesion and within the normal pancreatic tissue. Images were processed using Axius ACQ software; the following parameters were obtained: maximum intensity, arrival time, time-to-peak, and area under the curve. Absolute values and differences between the lesion and the normal tissue were evaluated. RESULTS Histology analysis revealed 45 PDACs and 15 inflammatory masses in patients with CP. Time-dependent parameters (arrival time and time to peak) were significantly longer in PDACs compared to focal masses. Although markedly lower than in healthy pancreata, the maximum intensity and area under the curve parameters were not significantly different between PDACs and focal lesions in patients with CP. CONCLUSIONS In cases of CP, PDAC and focal masses exhibit different perfusion patterns at a capillary level that can be visualized using the small microbubbles of ultrasound contrast agents. Contrast quantification software supplements a subjective visual assessment with objective criteria to facilitate the differential diagnosis of focal lesions in pancreatic cancer and chronic pancreatitis.

Colorectal liver metastasis surgery: analysis of risk factors predicting postoperative complications in relation to the extent of resection

Background/aimsDespite advances in diagnosis and treatment, the rate of complications after resection for colorectal liver metastases remains high. An awareness of risk factors is essential for the rates of morbidity and mortality to fall to optimal levels.Materials and methodsOf the 240 patients who underwent resection for the first manifestation of colorectal liver metastases, 49 patients with lobectomy or extended hepatectomy (major resections) and 58 with wedge resections within only one liver segment (minor resections) form the basis of this report. A total of 16 variables were analyzed to find the risk factors linked to postoperative morbidity and mortality.Results/findingsThirty-four patients (31.8%) suffered postoperative complications, and one patient died during the hospital stay (0.9%). In the major resection group, multivariate analysis showed that neoadjuvant chemotherapy [odds ratio (OR): 2.4; p = 0.005], vascular clamping (OR: 1.4; p = 0.008), and intraoperative blood loss with transfusion of three to six packed red cell units (OR: 1.2; p = 0.029) were significantly associated with postoperative morbidity. Vascular clamping was an independent predictor for biliary fistula (OR: 1.2; p = 0.029). Postoperative temporary liver failure was influenced by neoadjuvant chemotherapy (OR: 3.4; p = 0.010), vascular clamping (OR: 1.5; p = 0.015), and requirement of blood transfusion (OR: 2.1; p = 0.016). After minor resections, only a decreased postoperative serum cholinesterase B level was an independent predictor for complications (OR: 2.2; p = 0.001), as well as for hemorrhage (OR: 1.6; p = 0.023). Postoperative mortality was not predicted by any of the factors that were analyzed.Interpretation/conclusionFactors for complications differ depending on the extent of colorectal liver metastasis resection. Only knowledge and particular consideration of these factors may provide for an optimal postoperative outcome for the individual patient.

Transabdominal Contrast-Enhanced Ultrasonography of Pancreatic Cancer

Since its introduction, contrast-enhanced ultrasonography (CEUS) has significantly extended the value of ultrasonography (US). CEUS can be used to more accurately determine pancreatic lesions compared to conventional US or to characterize lesions already detectable by US. Thus, CEUS can aid in the differential diagnosis of pancreatic tumors. Using US contrast media, it is possible to visually detect microvessels in the majority of pancreatic ductal adenocarcinomas. Thus, the use of quantitatively evaluated transabdominal CEUS can help in the differentiation of patients with mass-forming pancreatitis from patients with pancreatic adenocarcinomas. In neuroendocrine pancreatic tumors, different enhancement patterns can be observed in relation to the tumor mass: larger ones show a rapid early enhancement sometimes combined with necrotic central structures, and smaller ones disclose a capillary-blush enhancement. Pseudocysts, the most widespread cystic lesions of the pancreas, are not vascularized. They do not show any signal in CEUS and remain entirely anechoic in all phases, while true cystic pancreatic tumors usually have vascularized septa and parietal nodules. In summary, CEUS is effective for differentiating solid pancreatic tumors in most cases. CEUS is safe and cost effective and can better discriminate solid from cystic pancreatic lesions, thereby directing further imaging modalities.

Contrast-enhanced ultrasonography in pancreas transplantation.

Background Pancreas transplantation remains a major surgery with potential complications that require reliable imaging despite impaired kidney function. Contrast-enhanced ultrasonography (CEUS) has been proven to be an indispensable tool in the evaluation of the native pancreas. Here, CEUS studies are extended to pancreas transplants for the first time. Methods A total of 42 B-mode, duplex, and CEUS exams performed using 1 mL SonoVue (Bracco) on a Siemens Acuson Sequoia ultrasound machine were evaluated in 14 pancreas transplant recipients. Time-intensity curves and curve characteristics were calculated. The data were compared between normal pancreas transplants, grafts undergoing rejection, and grafts after successful treatment of the rejection episode. Results All of the grafts could be well visualized in all ultrasound exams. Although the arterial resistive index did not differentiate between rejection and the absence of rejection, in CEUS, the time-intensity curves showed a significantly slower ascent and diminished maximum intensity in pancreas grafts during rejection, with significantly reduced maximum intensity and time to reach peak intensity. After the successful treatment of rejection, these parameters were almost restored to initial values. Discussion CEUS displays the capillary perfusion of the tissue. Edema of the pancreas graft during rejection impairs capillary perfusion, reflected in the amount of contrast detected by CEUS and the dynamics of the influx of the contrast agent. Conclusion CEUS yields useful information after pancreas transplantation and has been proven a sensitive tool in the surveillance of pancreas grafts. Further studies will be needed to differentiate rejection from other posttransplantation complications using CEUS.

Liposarcoma of the diaphragm: CT and sonographic appearances

Malignant tumors arising from the diaphragm are exceedingly rare. We describe the first case, to our knowledge, of a primary diaphragmatic liposarcoma and demonstrate computed tomographic and sonographic findings.

Color Doppler imaging predicts portal invasion by pancreatic adenocarcinoma.

AbstractBackgroundTumor infiltration of the intima of the portal vein (PV) and superior mesenteric vein (SMV) by pancreatic adenocarcinoma is classically considered a criterion for unsuitability for resection and poor prognosis. This study was performed to evaluate modern color duplex imaging (CDI) for the assessment of PV/SMV infiltration by pancreatic adenocarcinomas.MethodFrom 1994 to 2005, Whipple’s procedure or pylorus-preserving pancreato-duodenectomy (PPPD) was performed in 303 patients with pancreatic adenocarcinoma; 35 of these underwent partial PV/SMV resection. Applying a previously reported CDI score, we evaluated the integrity of the echogenic border layer between the vein and tumor (mural demarcation) and maximum blood flow velocity (Vmax) in the PV segment in contact with the tumor. The results were compared to the final histological findings in the resected venous walls.ResultsCDI findings correlated well with the histological invasion grades. By measuring Vmax and evaluating mural demarcation, we observed a sensitivity of 66.7% and 100% and a specificity of 98.3% and 93.9%, respectively, in predicting full thickness vein invasion, including the intima. Vmax above 80 cm/s and lack of mural demarcation were predictors of PV/SMV invasion. The postoperative survival rates depended on the depth of tumor infiltration into the PV/SMV.ConclusionsModern CDI is a reliable and valid technique for evaluation of morphological and hemodynamic parameters in the portal vein segment adjacent to pancreatic adenocarcinoma. Maximal blood-flow velocity in the portal segment in contact with the tumor and absence of the echogenic vessel-parenchymal sonographic interface are parameters predictive of tumor infiltration of the portal intima.

Frühergebnisse und Komplikationen der Chirurgie von Lebermetastasen

Summary. Following resection of liver metastases the overall prognosis still remains limited because of the lack of adjuvant therapy. The number of explorative laparotomies, non-radical resections and complications needs to be reduced. One hundred and ten laparotomies in 97 patients with liver metastases were performed with the intention to cure between October 1993 and February 1998. In a prospective analysis we reviewed: patient characteristics, characteristics of primary tumors and metastases, part and extent of liver resection, radicality, complications and mortality. Additionally, a prospective study about the value of ultrasonography and CT scan concerning the evaluation of preoperative liver findings was undertaken between January 1995 and February 1998. Altogether, resection of liver metastases was achieved in 75 cases (68.2 %). Nineteen patients (25.3 %) had postoperative complications. Two patients (2.7 %) died following liver resection. Thirty-five operations (31.8 %) had to be finished as only an explorative laparotomy. The major reason for these restricted operations was in 15 patients (42.9 %) regional recurrence or peritoneal metastases. Preoperative determination of the liver finding (quantity, localization and size) by ultrasonography and CT scan achieved an accuracy of 68.9 % each. The results of this analysis show that resection of liver metastases can be accomplished with minor morbidity and mortality. The high number of explorative laparotomies still remains a central problem in the surgery of liver metastases. By the introduction of duplex sonography and contrast-medium-enhanced helical CT scan, liver pathology can be defined more precisely in the preoperative evaluation. However, preoperative detection of regional recurrence or peritoneal metastases remains difficult.Zusammenfassung. Nach Resektion von Lebermetastasen bleibt die Prognose wegen einer fehlenden adjuvanten Therapie noch immer begrenzt. Die Zahl an Probelaparotomien, nicht radikalen Resektionen und Komplikationen sollte möglichst gering sein. Von Oktober 1993 bis Februar 1998 wurden bei 97 Patienten mit Lebermetastasen insgesamt 110 Laparotomien unter kurativem Ansatz durchgeführt. In einer prospektiven Analyse erfaßten wir: Patientendaten, Charakteristik der Primärtumoren und Metastasen, Anteil und Ausmaß der Leberresektion, Radikalität, Komplikationen und Letalität. Von Januar 1995 bis Februar 1998 wurde darüber hinaus eine prospektive Untersuchung zum Stellenwert von Sonographie und CT bei der Beurteilung des präoperativen Leberbefunds durchgeführt. Insgesamt konnte in 75 Fällen (68,2 %) eine Resektion der Lebermetastasen erreicht werden. Bei 19 Patienten (25,3 %) traten nach der Resektion Komplikationen auf. Zwei Patienten (2,7 %) starben nach Leberresektion. In 35 Fällen (31,8 %) wurde der Eingriff als Probelaparotomie beendet. Die Hauptursache für die Beschränkung auf eine explorative Laparotomie war bei 15 Patienten (42,9 %) ein locoregionäres Tumorrezidiv oder eine Peritonealcarcinose. Bei der präoperativen Beurteilung des Leberbefunds (Anzahl, Lokalisation, Größe) erreichten Sonographie und CT eine Genauigkeit von 68,9 %. Die Ergebnisse dieser Analyse zeigen, daß die Resektion von Lebermetastasen mit geringer Morbidität und Mortalität möglich ist. Ein zentrales Problem der Lebermetastasenchirurgie bleibt aber der hohe Anteil an Probelaparotomien. Durch die Einführung der Duplexsonographie und des Spiral-CTs mit Kontrastmittelbolus kann der Leberbefund präoperativ deutlich besser definiert werden. Das intraabdominale Tumorrezidiv außerhalb der Leber bleibt jedoch schwer nachweisbar.

Das seröse Cystadenom des Pankreas

Abstract.Introduction: Serous cystadenomas of the pancreas are rare tumors and thought to be almost always benign. Methods: We report our experience in the diagnosis and surgical treatment of 12 patients with these tumors. Results: Between October 1993 and December 1998, 41 patients with cystic tumors of the pancreas underwent surgical resection; in 12 cases (11 women, 1 man) a serous cystadenoma (10 micrcocystic, 2 oligomacrocystic) was found. Only 6 (50 %) patients had symptoms. The mean tumor size was 4.8 (2.7–10) cm. Ultrasound, CT and MRT usually could detect the mass, but differentiation with other cystic lesions was not reliable. All tumors were resected: 4 Whipple procedures, 7 distal pancreatectomies and 1 segmental resection were performed. No patient died after surgery and none had to be reoperated on. Conclusions: Because of the difficulty in reliably differentiating benign and malignant lesions of the pancreas, we believe that cystic tumors of the pancreas should be resected.Zusammenfassung.Einleitung: Seröse Cystadenome des Pankreas sind seltene Tumoren und gelten in der Regel als benigne. Methoden: In einer retrospektiven Auswertung werden die Daten zur Diagnostik und die Ergebnisse der chirurgischen Therapie analysiert. Ergebnisse: Im Zeitraum von Oktober 1993 bis Dezember 1998 wurden 41 Patienten mit einer cystischen Neoplasie des Pankreas operiert, bei 12 Patienten (11 Frauen, 1 Mann) fand sich histologisch ein seröses Cystadenom (10mal mikrocystisch; 2mal oligomakrocystisch). Nur 6 Patienten (50 %) waren symptomatisch, die Größe der Tumoren betrug im Mittel 4,8 (2,7–10) cm. Sonographie, CT und MRT erwiesen sich als zuverlässigste Untersuchungsverfahren zum Nachweis der neoplastischen Raumforderung, wobei jedoch eine differentialdiagnostische Zuordnung meist nicht möglich war. Alle Patienten wurden reseziert, dabei wurden 4 Whipple-Operationen, 7 Pankreaslinksresektionen und eine Segmentresektion durchgeführt. Kein Patient verstarb nach dem Eingriff, relaparotomiepflichtige Komplikationen traten ebenfalls nicht auf. Schlußfolgerungen: Angesichts der problematischen Abgrenzung benigner und maligner Raumforderungen des Pankreas stellt auch bei den cystischen Tumoren die Resektion die Therapie der Wahl dar.

Zystische Neoplasien des Pankreas

Zystische Neoplasien des Pankreas sind im Gegensatz zu den soliden Tumoren eher eine seltene Entitat. Sie sind eine heterogene Gruppe von verschiedenen Tumoren. Sie machen laut Literaturangab en ca 1 – 2% aller Pankreasneoplasien aus.

Präoperative dopplersonografische Beurteilung der Resektabilität von Pankreastumoren

Trotz des Einsatzes verschiedener bildgebender Verfahren ist die lokale Resektabilitat eines Pankreastumors haufig erst im Rahmen einer chirurgischen Exploration zu klaren. So liegt die Resektionsquote nach Literaturangaben zwischen 15 und 30% der diagnostizierten Falle. Anhand einer prospektiven Studie von Januar 1997 bis Oktober 1998 wurde ein Konzept zur duplexsonografischen Resektabilitatsbeurteilung von Pankreastumoren erarbeitet. In einer 2. prospektiven Studie (September 1998 bis April 2001) sollte dieses Diagnostikmodell validiert werden. Ziel unserer Arbeit ist es zu uberprufen, wie weit der Einsatz eines modernen Farbdopplersystems die Resektabilitatsvorhersage in der onkologischen Pankreaschirurgie beeinflust. Patienten und Methode:Im Rahmen einer prospektiven Studie wurden von Oktober 1998 bis zum April 2001 die Resektabilitat von 197 Raumforderungen am Pankreas duplexsonografisch mit dem intraoperativen Befund verglichen. Die Sonografien wurden von insgesamt 5 Untersuchern (darunter 4 Ausbildungsassistenten) durchgefuhrt.