Benno M. Ure

Stem-like Cells in Human Hepatoblastoma

Hepatoblastoma is a pediatric liver tumor with epithelial components resembling embryonal and fetal liver cells. The existence of teratoid hepatoblastoma suggests the presence of stem cells in hepatoblastoma. The aim of this study was to analyze the expression of stem cell markers in hepatoblastomas. We studied specimens from 10 hepatoblastomas. Five of the hepatoblastomas were of epithelial and five of mixed type. Immunohistochemistry (IHC) for the stem cell markers CD34, Thy1, c-kit, and the hepatic or biliary lineage markers CK-18, OCH, CK-7, and CD56 was performed. Double IHC for stem cell and lineage markers was used to identify putative liver stem cells. The different markers showed distinct distributions on the tumor cells. Cells in atypical ducts were found to express simultaneously stem cell markers and hepatocytic or biliary lineage markers. Other cells in connective tissue showed c-kit expression, but not hepatic or biliary marker expression. The data show the presence of different cell populations bearing stem cell markers in human hepatoblastoma. Ductal cells co-expressing stem cell markers and hepatic lineage markers phenotypically resemble hepatic stem-like cells. These findings support the thesis that stem cells play a role in the histogenesis of hepatoblastoma.

CO2 pneumoperitoneum increases survival in mice with polymicrobial peritonitis.

PURPOSE Laparoscopic techniques are commonly used in patients with bacterial peritonitis. CO2 is known to suppress local and systemic inflammatory responses. Nonetheless, an active immune system is needed to contain bacterial contamination of the abdominal cavity. Therefore, we investigated the early and late effects of CO2 pneumoperitoneum on the ability of mice to overcome polymicrobial peritonitis. MATERIAL AND METHODS Male C57/B6 mice were subjected to pneumoperitoneum with CO2 or helium, or underwent a midline laparotomy. In a first set, changes of arterial blood gases were monitored. In further experiments, polymicrobial peritonitis was induced after 1 h of pneumoperitoneum/laparotomy by cecal ligation and puncture. In a second set of experiments polymicrobial peritonitis was induced 4 h prior to exposure to pneumoperitoneum/laparotomy. After the interventions, survival rates (early survival: 6 to 48 h; late survival > 48 h) were monitored for 7 days. RESULTS There was no significant effect of pneumoperitoneum or laparotomy on arterial blood gas parameters. CO2 pneumoperitoneum significantly reduced the early (6 to 48 h) mortality of subsequent peritonitis after CO2 pneumoperitoneum compared to laparotomy (2/20 vs. 9/25; p < 0.05). The protective effect did not reach significance after 7 days (late mortality). The application of a helium peritoneum did not show any beneficial effect. Application of a CO2 pneumoperitoneum during polymicrobial peritonitis significantly reduced overall mortality (p < 0.05) compared to laparotomy. CONCLUSIONS The modulation of immune responses by CO2, but not helium pneumoperitoneum, has a significant positive impact on survival during abdominal sepsis in a mouse model. Thus, application of a CO2 pneumoperitoneum may be beneficial in conditions with bacterial contamination of the abdominal cavity.

Hemodynamic changes during acute elevation of intra-abdominal pressure in rabbits

Background:  The intra‐abdominal pressure (IAP) may be increased during pneumoperitoneum for minimally invasive surgery, after high tension repairs of congenital abdominal wall defects, major abdominal surgery, liver transplantation, abdominal trauma, peritonitis or ileus. The aim of this study was to investigate hemodynamic changes during elevation of IAP using an experimental setting, which mirrors anatomical and physiological conditions of neonates and small infants as closely as possible.

Excision of the Dilated Pelvis is not Necessary in Laparoscopic Dismembered Pyeloplasty

PURPOSE The surgical treatment of choice for significant hydronephrosis is dismembered pyeloplasty. While in open surgery, extensive resection of the dilated pelvis is common practice, laparoscopically usually only a sparing resection is performed. We compared the treatment results of both techniques to investigate whether extensive resection is necessary or not in dismembered pyeloplasty procedures. METHODS To obtain comparable renal units, matched pairs according to age and relative kidney uptake as shown by (123)J-orthoiodohippurate renography were selected out of a total of 76 patients who underwent dismembered pyeloplasty between 2000 and 2007. Twenty-four patients complied with the criteria for inclusion in the study. Changes in urinary drainage preoperatively and at three months postoperatively were compared between both groups. RESULTS The mean age in the sparing resection group was 3.8 years (range 0.3 to 14 years); in the extensive resection group it was 3.4 years (range 0.5 to 10 years). Mean urinary drainage improved significantly in both groups from 35.1 +/- 10.7 % to 75.2 +/- 13.2 % (sparing resection) vs. 45.1 +/- 23.7 % to 70.2 +/- 22 % (extensive resection). There were no differences between the groups (p > 0.05). CONCLUSIONS We conclude that extensive resection of the renal pelvis is not necessary in dismembered pyeloplasty procedures since there were no differences in the renographic outcome of comparable patients treated by the different surgical methods.

Carbon dioxide, Hypoxia and Low pH Lead to Overexpression of c-myc and HMGB-1 Oncogenes in Neuroblastoma Cells

PURPOSE It has been reported that CO (2) gas, used to establish a pneumoperitoneum during laparoscopy, affects the behavior of tumor cells. The proto-oncogenes C-MYC and HMGB-1 mediate aggressive behavior of neuroblastomas. We studied whether exposure to CO (2), hypoxia or acidosis affects the expression of C-MYC and HMGB-1 in neuroblastoma cells. METHODS SH-SY5Y cells were incubated with 100% CO (2), 95% helium/5% CO (2) or pH 6.2 for 2 h. The expression of C-MYC and HMGB-1 was measured by Western blot test immediately, 3 h and 6 h after incubation. Additionally, we measured apoptosis after incubation using fluorometric measurements of caspase 3 and 7 activity. RESULTS C-myc (160+/-26%, p=0.007 and 138+/-16% vs. control, p=0.04) and HMGB-1 proteins (140+/-13% and 136+/-11%, both p=0.037) were found to be significantly upregulated 6 h after incubation with CO (2) and helium. There was early upregulation of both oncogenes 3 h after CO (2) incubation (251+/-79%, p=0.04 and 292+/-136, p=0.037). Correspondingly, pH 6.2 led to significant overexpression. Levels of apoptosis were reduced. CONCLUSIONS Exposures mimicking conditions of CO (2) pneumoperitoneum lead to significant overexpression of C-MYC and HMGB-1 in neuroblastoma cells with decreased apoptosis. These results point to a negative influence and potentially increased malignancy of tumor cells.

Laparoscopically assisted ventriculoperitoneal shunt placement in infants with previous multiple abdominal operations.

BACKGROUND The insertion of a ventriculoperitoneal shunt (VPS) is the treatment of choice in patients with hydrocephalus. However, VPS placement may be difficult in patients with extensive adhesions following prior abdominal interventions. Laparoscopic placement of the abdominal part of the VPS allows controlled adhesiolysis in combination with an optimal shunt placement in patients with a body weight above 5 kg. We investigated the feasibility and safety of laparoscopic VPS placement in young infants who had undergone abdominal operations. PATIENTS AND METHODS In our institution, 6 children with prior laparotomies (range: 2-9; median 3) received a VPS catheter between 2004 and 2008. The median age was 9 months (range: 2 months-4 years) and the median body weight was 4.5 kg (3.5-8.2 kg). All procedures were laparoscopically assisted and performed simultaneously by an interdisciplinary neurosurgical and a pediatric surgical team. RESULTS Median operating time was 63 min (35-100 min). In all cases, correct placement of the shunt with sufficient drainage was achieved. Enteral feeding was started on the day of operation in all patients. Median follow-up was 10 months (range: 2 months-3 years). There were no complications except in one patient, who developed shunt dysfunction 4 weeks postoperatively and underwent a laparoscopic shunt revision. CONCLUSION In our series laparoscopically assisted VPS insertion in low-weight children who had undergone repeated prior abdominal surgery was feasible and had a low complication rate. We recommend laparoscopically assisted VPS insertion in small infants to avoid the complications of alternative techniques, such as open techniques or ventriculoatrial shunt.

CO2 modulates the inflammatory cytokine release of primary human pleural macrophages.

BACKGROUND It is well known that CO (2) used during laparoscopy affects the peritoneal surface and local inflammatory response, including the inflammatory reactivity of peritoneal macrophages. However, little is known about the local effects of CO (2) during thoracoscopy. In a previous study we have shown that in healthy adolescents, macrophages are the dominant cell population on the pleural surface. Therefore, we examined the effects of CO (2) on the inflammatory response of primary human pleural macrophages. METHODS Human primary macrophages were harvested lavage from healthy adolescents undergoing elective surgery for pectus bar correction (n=8). After purification and 24 h resting, cells were incubated for 2 h in 100% CO (2), 5% CO (2) or 95% inert helium with 5% CO (2) as hypoxic control. After incubation cells were stimulated with LPS for 4 h and 24 h. The release of TNF-alpha, IL-8, IL-6, IL-10 and IL-1 beta were determined by ELISA. RESULTS CO (2), but not hypoxia, induced a significant reduction in the release of TNF-alpha and IL-8 as well as a significant increase in the release of IL-10 and IL-1 beta within the first 4 h after incubation. The levels of IL-6 and the release of cytokines at 24 h after incubation were not significantly affected. CONCLUSIONS CO (2) directly modulates the immediate inflammatory response of pleural macrophages. Therefore, CO (2) insufflation during thoracoscopy could lower the local stress response, but does not appear to have a lasting effect.

Laparoscopy for suspected appendicitis in children: May a macroscopically normal appendix be left in situ?

BACKGROUND/PURPOSE An appendix which appears macroscopically normal is found in 10%-20% of laparoscopic explorations for suspected appendicitis. The appropriate surgical strategy for these cases is a matter of debate. We analysed a consecutive series of children in whom an inconspicuous appendix was left in situ. MATERIAL AND METHODS Laparoscopic exploration was performed in 188 consecutive children with suspected appendicitis and an expected need for immediate operation from 2002 to 2006. Our concept included laparoscopic appendectomy in patients with macroscopic signs of inflammation. Normal appearing appendices were left in situ. All patients with a remaining appendix underwent follow-up. Major endpoints were defined as postoperative complications, re-operations for abdominal symptoms, hospital admissions and consultations with medical doctors during the follow-up period. In addition, other symptoms and well-being were assessed. RESULTS The appendix appeared macroscopically normal in 21 (11%) of the 188 patients (mean age 11.7 years (+/-4.2); 11 f, 10 m), and was therefore left in situ. The immediate postoperative course was uneventful in all patients with a mean hospital stay of 2.7 (+/-1.2) days. During the follow-up period (mean of 25 (+/-17) months), 18 patients (86%) did not or only rarely (< or = 2 times) consult a medical doctor for abdominal symptoms. Three patients (14%) reported more than 2 consultations. No patient was readmitted to hospital or operated for acute appendicitis. At the last follow-up, 20 patients (95%) were entirely symptom-free. One patient complained about persisting right lower quadrant pain, but refused further diagnostic procedures or interventions. CONCLUSION According to our results, a macroscopically inconspicuous appendix may be left in situ in patients undergoing laparoscopy for suspected appendicitis. However, this conclusion is based on a small number of patients and larger series are mandatory.

Thoracic Surgery in Children and Adolescents

Description: The diagnosis and treatment of both congenital and acquired thoracic pathologies in children and adolescents require a high degree of specialization. This book provides practical guidelines for thoracic surgeons who operate on patients from neonatal age to adolescence and for pediatric surgeons who are challenged to treat disorders such as cystic malformations of the lung, mediastinal tumors, or chest wall deformities. The chapters, written by internationally acclaimed authors, include expert commentaries with tips and tricks for the clinical practice.

Unerwarteter Verlauf eines stumpfen Abdominaltraumas

ZusammenfassungIm vorliegenden Beitrag wird über den Fall eines 12-jährigen Jungen mit traumatischer Ruptur einer pulmonalen Echinokokkuszyste durch stumpfes Abdominaltrauma bei bis dahin unbekannter zystischer Echinokokkose mit Beteiligung von Lungen und Leber berichtet. Nach Sicherung der Diagnose wurde eine präoperative Albendazoltherapie begonnen. Im weiteren Verlauf erfolgte die elektive Resektion der pulmonalen und der hepatischen Echinokokkuszysten in 2 konsekutiven Eingriffen. Sechs Monate postoperativ ist der Patient beschwerdefrei.AbstractThis article presents a case report of a 12-year-old boy with rupture of a previously undiagnosed pulmonary hydatid cyst following blunt abdominal trauma. After confirmation of the diagnosis albendazole treatment was started. Elective resection of the pulmonary and hepatic hydatid cysts was performed as a two-stage procedure. The patient is symptom-free 6 months after surgery.