Matthias Pietschmann

Laparoscopic Fluorescence Diagnosis for Intraabdominal Fluorescence Targeting of Peritoneal Carcinosis: Experimental Studies

ObjectiveTo assess 5-aminolevulinic acid (ALA)-induced protoporphyrin IX accumulation and fluorescence in peritoneal colon carcinoma metastases and its benefits for laparoscopic fluorescence diagnosis. Summary Background DataOccult, macroscopically nonvisible peritoneal micrometastases can be missed in laparoscopy or open surgery. Laparoscopic fluorescence diagnosis allows detection of these lesions after intraperitoneal lavage with ALA and subsequent fluorescence induction by blue-light excitation. MethodsA disseminated peritoneal carcinosis was induced by laparoscopic implantation of colon carcinoma cells (CC531) in the peritoneum of 55 WAG/Rij rats. After 12 days of tumor growth the animals were randomized into 11 groups with different photosensitization parameters. Peritoneal lavage was performed either with 1.5% or 3.0% ALA solution, except for one control group. Photosensitization times were 0.5, 1, 2, 4, or 8 hours. Spectrometry was performed using an optical multichannel analyser. ALA and protoporphyrin IX serum levels were measured by high-performance liquid chromatography to determine systemic load. ResultsProtoporphyrin IX tumor accumulation and fluorescence peaked 2 to 4 hours after ALA application in both main groups, 1.5% and 3.0% ALA. Tumor detection rate was most effective in the 1.5% ALA group. Compared with conventional white-light laparoscopy alone, blue-light excitation detected 35% additional intraabdominal tumor foci. ConclusionsLaparoscopic fluorescence diagnosis can increase the sensitivity and specificity of diagnostic staging laparoscopy. It allows determination of the extent of peritoneal carcinosis. Improved preoperative assessment helps to avoid unnecessary laparotomies and radical resections.

Improving diagnostic staging laparoscopy using intraperitoneal lavage of δ-aminolevulinic acid (ALA) for laparoscopic fluorescence diagnosis

BACKGROUND Lymph node metastases and peritoneal carcinosis, occurring as a result of gastrointestinal cancer, reduce the likelihood that conventional therapy will be adequate to remove the cancer. Although diagnostic techniques have greatly improved, it is not always possible to diagnose the entire extent of the metastases. Often, peritoneal micrometastases are not visible and may be missed during laparoscopic or open surgery. METHODS Peritoneal carcinosis was induced in WAG-Rij rats (n = 6), by laparoscopically implanting 1,2-dimethylhydrazine-induced colon carcinoma tumor cells (CC531, 5 x 10(5)) at multiple sites within the peritoneal cavity. After 12 days of tumor growth, the animals were given delta-aminolevulinic acid (ALA) (5 mL, 3% solution in 0.17 mol/L NaHCO3) by peritoneal lavage. The tumors were visualized laparoscopically using both white and blue light (D-light, Karl Storz, Tuttlingen, Germany). Fluorescence was detected by using a modified CCD camera and a special observation filter incorporated into the laparoscope. RESULTS Peritoneal carcinoma foci ranging in size from 0.05 to 2.0 cm were clearly visible laparoscopically with conventional white light (n = 142). After blue light excitation, all 142 tumors identified with white light were also identified by fluorescence. There were an additional 30 tumors that could only be identified by blue light-induced fluorescence and were histologically confirmed to be derived from colon carcinoma tumor cells. CONCLUSIONS Peritoneal colonic carcinoma foci were detected laparoscopically after intraperitoneal lavage with delta-aminolevulinic acid (ALA) and excitation with blue light. These experiments demonstrate that fluorescence laparoscopy is an important technique for the staging of gastrointestinal cancer, including colorectal cancer, because of the enhanced ability to detect small cancerous foci.

Alcohol Pretreatment Increases Hepatic and Pulmonary Injury in Experimental Pancreatitis

Background: Systemic complications including pancreatitis-associated lung injury (PALI) are critical factors that determine the outcome of severe necrotizing pancreatitis (SNP). The aim of the present study was to evaluate the role of chronic alcohol exposure on the development of PALI. Methods: 48 rats were fed either a Lieber deCarli control or alcohol diet for 6 weeks. After completion, SNP was induced by intraductal infusion of bile salt followed by intravenous infusion of cerulein over 6 h. Control animals received i.v. Ringer’s solution. Intravital microscopy of the liver was performed 6 h after induction of SNP to evaluate hepatic perfusion and leukocyte adhesion. Serum parameters, edema, inflammation, and histological changes were evaluated at 12 h. IL-6 levels were evaluated in portal venous and systemic blood as well as in pancreatic tissue homogenates. Results: Alcohol pretreatment did not affect pancreatic injury in SNP. PALI was aggravated after alcohol ingestion. These animals showed increased hepatic microcirculatory disturbances, compared to SNP alone. IL-6 showed peak levels in SNP with alcohol pretreatment, although they were also elevated in SNP alone. Systemic levels of IL-6 were higher than in the portal vein. Conclusion: In SNP, alcoholic pretreatment increases pulmonary damage, while pancreatic injury is identical. The liver seems to participate in this effect by increased hepatic cytokine release.

Alkoholpankreatitis-assoziierte pulmonale Komplikationen sind schwerwiegender als bei biliärer Pankreatitis: Bedeutung der Lebermikrozirkulation und systemischer Zytokine

Systemic complications including pancreatitis associated lung injury are the main predominators for the outcome of severe pancreatitis. The aim of the present study was to evaluate whether pulmonary complications in acute pancreatitis are more likely to develop in alcoholics, and whether cytokine release and microcirculation of the liver play a pathophysiological role. MethodsAfter feeding rats with either LieberdeCarli a) control diet (CD) or b) alcohol diet (AD) for 6 weeks, an experimental severe pancreatitis was induced (CD-SP and AD-SP; n = 12/group). Control animals received Ringers solution i.v. (CD-C and AD-C). Intravital microscopy of the pancreas and liver were performed at 6hrs and pancreatic, liver and lung injury were evaluated at 12 hrs. Cytokines were evaluated in portal and systemic blood. ResultsPancreatic injury was not increased by AD-C compared to CD-Co Moreover, pancreatic microcirculatory disturbances and pancreatic injury were not different between AD-SP and CD-SP, but lung injury was more pronounced in AD-SP. The microcirculation of the liver was changed by both alcohol diet alone and acute pancreatitis alone, but was even more disturbed in alcoholic rats. IL-6 levels were significantly elevated in CD-SP, and even more in AD-SP. Systemic levels of IL-6 were significantly higher than in the portal blood. ConclusionAlcoholic pancreatitis is associated with a significant more severe lung injury than biliary disease. Pronounced disturbances of the liver microcirculation in alcoholic rats seem to induce a higher hepatic release of cytokines, and by that may trigger pancreatitis associated lung injury.

Fluorescence staging laparoscopy for gastrointestinal malignancies: experimental experience

Accurate staging can be a major problem in therapeutic planning of advanced abdominal malignancies. We experimentally combined conventional staging laparoscopy with aminolevulinic acid (ALA) induced fluorescence diagnosis (FD) to improve the detection of disseminated peritoneal tumors. Using different photosensitization times and ALA concentrations we evaluated the optimal fluorescence parameters for laparoscopic fluorescence diagnosis of intra abdominal tumor spread. In a rat tumor model we performed conventional and fluorescence laparoscopy to determine the increase of sensitivity gained by FD in terms of additionally detected lesions. After laparoscopic examination, the fluorescence emission from the tumors was spectrometically analyzed. Serum levels of ALA and PpIX were measured by HPLC to determine their systemic metabolism. Fluorescence staging laparoscopy was able to visualize even macroscopically occult neoplasms. Using 1.5 percent ALA solution and a photosensitization time of 4 hours as favorable parameters the diagnostic value of conventional staging laparoscopy was significantly improved: 35 percent of all malignant lesions were detected only by FD. Therefore, fluorescence laparoscopy suggest to be a highly promising preoperative staging tool requiring minimal technical and clinical expenditure. It provides the laparoscopist with a rapid and accurate technique to assess more thoroughly the full extent of malignant tumor growth in the abdominal cavity.

Evaluierung der laparoskopischen Fluoreszenzvisualisierung von Peritonea lkarzinosen unter Verwendung von δ-Aminolävulinsäure (ALA)

Das Vorhandensein einer Peritonealkarzinose hat auf die adaquate Therapie gastrointestinaler Karzinome entscheidenen Einflus [1,2]. Die Diagnose ist jedoch an die makroskopische Erkennung mit anschliesender histologischer Verifizierung der Probeentnahme gebunden. Bei der Fluoreszenzdiagnostik konnen makroskopisch nicht sichtbare Tumore durch tumorspezifische Anreicherung sogenannter Fluoreszenzmarker (FM) and geeigneter Lichtanregung visualisiert werden [3, 4]. Bei der endogenen Photosensibilisierung des Tumors wird dazu das exogen zugefuhrte Substrat δ-Aminolavulinsaure (ALA) im Tumor vermehrt zu Protoporphyrin IX (PpIX) umgewandelt. PpIX selbst ist der letzte Schritt in der Hambiosynthese und kann mit Licht einer definierten Wellenlange zur Fluoreszenz angeregt werden. Die optimale Anregungswellenlange richtet sich nach dem jeweiligen Absorptionsspektrum des verwendeten FM. Die zu beobachtende Fluoreszenz bei PpIX liegt im sichtbaren roten and fur Porphyrine typischen Spektralbereich (635 nm) [4, 5]. Ziel dieser Untersuchung war es, die exakte Ausdehnung einer Peritoneallcarzinose laparoskopisch and fluoreszenzoptisch moglichst einfach zu visualisieren und zu verbessern, indem im Vergleich zur konventionellen Laparoskopie mehr intraabdominelle Tumore diagnostiziert werden konnen. Eine mogliche systemische Photosensibilisierung sollte abgeschatzt werden.