German guideline diverticular disease/diverticulitis: Part I: Methods, pathogenesis, epidemiology, clinical characteristics (definitions), natural course, diagnosis and classification.

Diverticulosis and diverticular disease are ranked among the most common gastroenterological diseases and conditions. While for many years diverticulitis was found to be mainly an event occurring in the elder population, more recent work in epidemiology demonstrates increasing frequency in younger subjects. In addition, there is a noticeable trend towards more complicated disease. This may explain the significant increase in hospitalisations observed in recent years. It is not a surprise that the number of scientific studies addressing the clinical and socioeconomic consequences in the field is increasing. As a result, diagnosis and conservative as well as surgical management have changed in recent years. Diverticulosis, diverticular disease and diverticulitis are a complex entity and apparently an interdisciplinary challenge. To meet theses considerations the German Societies for Gastroenterology and Visceral Surgery decided to create joint guidelines addressing all aspects in a truely interdisciplinary fashion. The aim of the guideline is to summarise and to evaluate the current state of knowledge on diverticulosis and diverticular disease and to develop statements as well as recommendations to all physicians involved in the management of patients with diverticular disease.

Minimal vascular flows cause strong heat sink effects in hepatic radiofrequency ablation ex vivo.

BACKGROUND: The present paper aims to assess the lower threshold of vascular flow rate on the heat sink effect in bipolar radiofrequency ablation (RFA) ex vivo. METHODS: Glass tubes (vessels) of 3.4 mm inner diameter were introduced in parallel to bipolar RFA applicators into porcine liver ex vivo. Vessels were perfused with flow rates of 0 to 1,500 ml/min. RFA (30 W power, 15 kJ energy input) was carried out at room temperature and 37°C. Heat sink effects were assessed in RFA cross sections by the decrease in ablation radius, area and by a high-resolution sector planimetry. RESULTS: Flow rates of 1 ml/min already caused a significant cooling effect (P ≤ 0.001). The heat sink effect reached a maximum at 10 ml/min (18.4 mm/s) and remained stable for flow rates up to 1,500 ml/min. CONCLUSIONS: Minimal vascular flows of ≥1 ml/min cause a significant heat sink effect in hepatic RFA ex vivo. A lower limit for volumetric flow rate was not found. The maximum of the heat sink effect was reached at a flow rate of 10 ml/min and remained stable for flow rates up to 1,500 ml/min. Hepatic inflow occlusion should be considered in RFA close to hepatic vessels.

Rectal anatomy after rectopexy: cinedefecography versus MR-defecography.

BACKGROUND: Conventional defecography can reveal abnormalities in patients with evacuatory disorders. With fast dynamic MR imaging systems, MR-defecography has become possible, which does not expose patients to ionizing radiation. The purpose of this study was to assess the correlation of both methods after rectopexy. MATERIALS AND METHODS: Twenty-one consecutive patients underwent abdominal sigmoidectomy and rectopexy due to evacuatory disorders. Postoperatively, all patients were investigated by cineradiographic defecography. Fourteen patients underwent MR-defecography additionally. The results were screened for anorectal angle and pelvic floor position (rest, squeezing, and evacuation). The findings were depicted in Box plot analysis and compared with the Friedman-test. Descent of pelvic organs was also assessed. RESULTS: In MR-defecography, anorectal angle at rest was smaller than in conventional defecography, but there was no difference during squeezing and defecation. Concerning pelvic floor position, during squeezing, MR-defecography illustrated a lower perineum and a broader range of pelvic settings, but no difference at rest and during evacuation. In four patients, MR-defecography visualized a descent of the bladder. However, in four patients with complete evacuation in cineradiography and with no clinical complaints about incomplete evacuation, MR imaging showed deficient evacuation. Overall continence of patients was significantly improved through surgery, but there was no change in sphincter pressure, radial asymmetry, or sphincter length. CONCLUSIONS: In general, with respect to anorectal angle and perineal motility, both methods revealed consistent results. The concomitant depiction of structures in MR-defecography is helpful in the assessment of descent of pelvic organs and permits visualization of enteroceles. However, in 30% of patients, MR-defecography wrongly showed incomplete evacuation.

The German registry for natural orifice translumenal endoscopic surgery: report of the first 551 patients.

OBJECTIVE: To analyze patient outcome in the first 14 months of the German natural orifice translumenal endoscopic surgery (NOTES) registry (GNR). SUMMARY BACKGROUND DATA: NOTES is a new surgical concept, which permits scarless intra-abdominal operations through natural orifices, such as the mouth, vagina, rectum, or urethra. The GNR was established as a nationwide outcome database to allow the monitoring and safe introduction of this technique in Germany. METHODS: The GNR was designed as a voluntary database with online access. All surgeons in Germany who performed NOTES procedures were requested to participate in the registry. The GNR recorded demographical and therapy data as well as data on the postoperative course. RESULTS: A total of 572 target organs were operated in 551 patients. Cholecystectomies accounted for 85.3% of all NOTES procedures. All procedures were performed in female patients using transvaginal hybrid technique. Complications occurred in 3.1% of all patients, conversions to laparoscopy or open surgery in 4.9%. In cholecystectomies, institutional case volume, obesity, and age had substantial effect on conversion rate, operation length, and length of hospital stay, but no effect on complications. CONCLUSIONS: Despite the fact that NOTES has just recently been introduced, the technique has already gained considerable clinical application. Transvaginal hybrid NOTES cholecystectomy is a practicable and safe alternative to laparoscopic resection even in obese or older patients.

Fluid resuscitation with human albumin or hydroxyethyl starch--are there differences in the healing of experimental intestinal anastomoses?

OBJECTIVES: Restoration of the macro- and microcirculation is important for the healing of gastrointestinal anastomoses. Colloids and crystalloids are widely used for blood volume therapy. We evaluated the effects of human albumin, hydroxyethyl starch (HES) 130/0.4 and saline on the microcirculation and on wound healing in colon anastomoses in rats. MATERIAL AND METHODS: Male Wistar rats received a colonic end-to-end anastomosis. The animals were randomized into three groups and a single 3-ml dose of either 20% human albumin, 6% HES 130/0.4 or 0.9% saline was applied intravenously. Six, 24, 48, 96 h and 2 weeks after the procedure, 10 animals per group were reanesthetized. Measurements of capillary blood flow, vessel permeability and anastomosis bursting pressure were performed. The amounts of vascular endothelial growth factor (VEGF) and IL-6 in the plasma were determined by enzyme-linked immunosorbent assays, and the mRNA levels of VEGF and collagen types I and III were measured by real-time polymerase chain reaction. RESULTS: No significant differences were found between albumin, HES 130/0.4 and saline in capillary blood flow, vessel permeability and anastomotic bursting pressure in this rat model. Concentrations of collagen I and III mRNA were significantly elevated after 96 h in animals that had received HES 130/0.4 or albumin. RNA and protein levels of VEGF and interleukin-6 were unaffected by therapy. CONCLUSIONS: Human albumin, which is still widely used in the clinical setting, had no advantage over HES 130/0.4 and saline with regard to anastomotic healing in this animal model. Nevertheless, we prefer HES 130/0.4 because it is more effective for volume therapy than saline and has a better availability and is less expensive than human albumin.

Association between activation of atypical NF-kappaB1 p105 signaling pathway and nuclear beta-catenin accumulation in colorectal carcinoma.

Recent studies have demonstrated that increased expression of coding region determinant-binding protein (CRD-BP) in response to beta-catenin signaling leads to the stabilization of beta-TrCP1, a substrate-specific component of SCF E3 ubiquitin ligase complex, resulting in an accelerated degradation of IkappaBalpha and activation of canonical nuclear factor-kappaB (NF-kappaB) pathway. Here, we show that the noncanonical NF-kappaB1 p105 pathway is constitutively activated in colorectal carcinoma specimens, being particularly associated with beta-catenin-mediated increased expression of CRD-BP and beta-TrCP1. In the carcinoma tissues exhibiting high levels of nuclear beta-catenin the phospho-p105 levels were increased and total p105 amounts were decreased in comparison to that of normal tissue indicating an activation of this NF-kappaB pathway. Knockdown of CRD-BP in colorectal cancer cell line SW620 resulted in significantly higher basal levels of both NF-kappaB inhibitory proteins, p105 and IkappaBalpha. Furthermore decreased NF-kappaB binding activity was observed in CRD-BP siRNA-transfected SW620 cells as compared with those transfected with control siRNA. Altogether, our findings suggest that activation of NF-kappaB1 p105 signaling in colorectal carcinoma might be attributed to beta-catenin-mediated induction of CRD-BP and beta-TrCP1.

Ex vivo and in vivo evaluation of laser-induced thermotherapy for nodular thyroid disease.

BACKGROUND AND OBJECTIVE: The prevalence of thyroid nodules ranges between 2% and 60% depending on the population studied. However, minimally invasive procedures like laser-induced thermotherapy (LITT) are increasingly used to treat tumors of parenchymatous organs and seem to be suitable for singular thyroid nodules as well. Their successful clinical application depends on the induction of sufficiently large lesions and a knowledge of the energy parameters required for complete thermal ablation. The aim of this study was to establish a dose-response relationship for LITT of thyroid nodules. MATERIALS AND METHODS: Thermal lesions were induced in healthy porcine thyroid glands ex vivo (n = 110) and in vivo (n = 10) using an Nd:YAG laser (1,064 nm). Laser energy was applied for 300 seconds in a power range of 10-20 W. During the ablation, continuous temperature measurement at a distance of 5 and 10 mm from the applicator was performed. The lesions were longitudinally and transversally measured, and the volume was calculated. Furthermore, enzyme histochemical analysis of the thyroid tissue was performed. RESULTS: The maximum inducible lesion volumes were between 0.74 +/- 0.18 cm(3) at a laser power of 10 W and 3.80 +/- 0.41 cm(3) at 20 W. The maximum temperatures after ablation were between 72.9 +/- 2.9 degrees C (10 W) and 112.9 +/- 9.2 degrees C (20 W) at a distance of 5 mm and between 49.5 +/- 2.2 degrees C (10 W) and 73.2 +/- 6.7 degrees C (20 W) at a distance of 10 mm from the applicator. The histochemical analysis demonstrates a complete loss of NADPH dehydrogenase activity in thermal lesions as a sign of irreversible cell damage. CONCLUSIONS: This study is the first to demonstrate a dose-response relationship for LITT of thyroid tissue. LITT is suitable for singular thyroid nodules and induces reproducible clinically relevant lesions with irreversible cell damage in an appropriate application time.

Comparative expression analysis and characterization of 20S proteasomes in human intestinal tissues: The proteasome pattern as diagnostic tool for IBD patients.

BACKGROUND: The diagnostic differentiation between Crohn's disease (CD) and ulcerative colitis (UC) is sometimes difficult. To date, there are no serological markers that are specific and sensitive enough to differentiate between these 2 diseases. Early and safe prediction of the inflammatory bowel disease (IBD) type is of great importance for the specific treatment of IBD patients. We thus analyzed and compared the expression of catalytic proteasome subunits in the gut of mice and in the normal and inflamed intestines of CD and UC patients and assessed whether the subunit pattern is suitable for diagnostic differentiation. METHODS: The 20S proteasomes were isolated from surgical tissue specimens derived from terminal ileum and colon of IBD patients and controls. Spots of 20S proteasomes separated by 2D electrophoresis were analyzed by mass spectrometry. Quick detection of catalytic beta2, beta2i, and beta5i subunits was performed by incubating proteasomes with a biotinylated inhibitor (AdaK(Bio)Ahx3L3VS) and subsequently by streptavidin-horseradish peroxide. RESULTS: 20S proteasomes were isolated from the human liver, colon, and terminal ileum. Low expression of the immunosubunits beta1i and beta2i was found in the liver and colon but high amounts in the small intestine. In colon and liver beta5i was found to be associated with the constitutive beta1, beta2 subunits, indicating the existence of mixed proteasomes. Further, inflammation in CD but not UC patients induced massive upregulation of beta1i and beta2i in the colon and terminal ileum, indicating the importance of this protein complex as a disease marker. CONCLUSIONS: We here show that CD and UC patients display a characteristic pattern of proteasome subunit composition which can be used as diagnostic tool to differentiate between CD and UC.

Total extraperitoneal hernioplasty: does the long-term clinical course depend on the type of mesh?

INTRODUCTION: Implantation of alloplastic material has become a standard surgical procedure in inguinal hernia repair. The properties of different meshes are discussed as determinants of postoperative outcome. The aim of this study was to comparatively evaluate long-term results after total extraperitoneal hernioplasty (TEP) with a heavyweight polypropylene mesh (PP) and a lightweight polypropylene-polyglactin composite mesh (PP-PG) in a large patient population. MATERIALS AND METHODS: The study included patients who underwent TEP for elective repair of uni- or bilateral inguinal hernias between June 1997 and October 2004. We used a heavyweight PP mesh from June 1997 to February 2001 and a lightweight PP-PG mesh from March 2001 to October 2004. Patient data were evaluated by a prospective online registry, and long-term results were assessed by standardized ad hoc questionnaires after a minimum follow-up of 12 (12-103) months. RESULTS: Five hundred twenty-two patients aged 18-87 years underwent surgical repair of 655 inguinal hernias, and 370 (70.8%) were evaluated. TEP was performed with PP mesh in 192 cases and with PP-PG mesh in 169 cases. Nine patients died during follow-up; 14.6% (PP) versus 20.1% (PP-PG) patients complained of mild pain, and 8.9% (PP) versus 5.3% (PP-PG) patients reported moderate to severe pain (P > 0.05). Mild dysesthesias occurred in 13.5% of the PP group and 11.8% of the PP-PG group (P = 0.63). Moderate to severe dysesthesias were reported by 6.8% with a heavyweight mesh and by 3.0% with a lightweight mesh (P = 0.10). There were no significant differences with regard to the patients' postoperative return to normal daily activities. The recurrence rate was 5.2% with a PP mesh and 1.8% with a PP-PG mesh (P = 0.08). CONCLUSIONS: The long-term results after TEP showed no difference between PP and PP-PG meshes with regard to chronic pain, chronic dysesthesias, postoperative daily activities, and recurrence rates.

Influence of intrahepatic vessels on volume and shape of percutaneous thermal ablation zones: in vivo evaluation in a porcine model.

OBJECTIVES: Aim of the study was to evaluate the precise influence of different intrahepatic vessels, vessel sizes, and distances from the applicator on volume and shape of hepatic laser ablation zones in an in vivo porcine model. MATERIALS AND METHODS: The study was approved by the institutional animal care and use committee. Eighteen computed tomography-guided Nd:YAG laser ablations were performed in the livers of 10 pigs at varying distances from hepatic veins and portal fields. After hepatectomy the livers were cut into 2-mm slices perpendicular to the laser applicator axes. For each ablation zone the maximum achievable (ideal) volume, the segmented (real) volume, the maximum radius, and the radius at the position of adjacent hepatic vessels were determined. The shapes of the ablation zones were evaluated qualitatively. Comparative statistics using the unpaired t test and a multiple linear regression analysis were performed. RESULTS: Ideal and real ablation zone volumes differed by 27.3% (8.6 +/- 1.5 mL vs. 6.4 +/- 1.1 mL; P < 0.0001). Thirty-eight of 60 (63%) hepatic veins versus 28 of 31 (90%) portal veins within the central slices of the 18 ablation zones led to a reduction of the ablation zone's radius, depending on the distance between the vessel and the applicator and the vessel type. Portal fields revealed stronger effects than hepatic veins. The vessel diameter showed no independent effect (P > 0.05). When influencing, all hepatic veins showed a focal indentation whereas portal fields always showed broad flattening of the ablation zone. CONCLUSIONS: Portal fields lead to more heat sink than hepatic veins. The effects decreased with the distance between vessel and applicator tip, but less so for portal fields. The 2 vessel types induced considerably different shape alterations of the ablation zones. These results were not dependent on vessel size. This should be considered in the planning of thermal tumor ablations.

Multipolar radiofrequency ablation of hepatic tumors: initial experience.

Institutional review board approval and patient informed consent were obtained. Use of a multipolar radiofrequency (RF) ablation device in patients with hepatic malignancy was prospectively evaluated with regard to feasibility, achieved ablation zone size and shape, technical effectiveness, and complications. Nineteen malignant liver tumors were treated with the multipolar resistance-controlled RF ablation system, with which up to three internally cooled bipolar coagulation electrodes can be operated simultaneously. Postinterventional imaging was performed with dynamic contrast material-enhanced magnetic resonance (MR) imaging and MR imaging-based three-dimensional planimetry. Complete tumor destruction was achieved in 18 of 19 tumors. Mean ablation zone volume was 52 mL +/- 45 (standard deviation). Thirteen patients were treated with a percutaneous approach; six, with an intraoperative approach. Maximum ablation size was 91 x 62 x 79 mm with the percutaneous and 73 x 98 x 74 mm with the intraoperative approach. Of the 18 completely evaluable ablation zones, 13 were concentric, two were moderately eccentric, two were eccentric, and one was wedge-shaped. The multipolar RF ablation device achieves large ablation zones and has high technical effectiveness in treating hepatic tumors.

Enhancement of the immune response to residual intrahepatic tumor tissue by laser-induced thermotherapy (LITT) compared to hepatic resection.

BACKGROUND AND OBJECTIVES: In contrast to hepatic resection, thermally destroyed autologous tumor cells remain in situ after laser-induced thermotherapy (LITT). The aim of the study was to evaluate the effect of LITT and hepatic resection on the immune response to residual intrahepatic tumor tissue and the growth of untreated liver metastases. STUDY DESIGN/MATERIALS AND METHODS: Two independent adenocarcinomas (CC531) were implanted into 60 WAG rats, one in the right (control tumor) and one in the left liver lobe (treated tumor). The left lobe tumor was treated either by LITT or partial hepatectomy. The control tumor was submitted to further investigation 24 hours, 96 hours, 7 days, and 10 days after treatment. RESULTS: Ten days after treatment, control tumor volumes were 296+/-46 mm_ after LITT and 1,181+/-192 mm_, 1,387+/-200 mm_ after hepatic resection and no treatment, respectively (P<0.001). Peritoneal tumor spread was detected in 4/20 cases after LITT and in 17/20 cases after hepatic resection. Expression of CD8, B7-2 (CD86), and to lesser extent MHCII, LFA1 (CD11a), and ICAM1 (CD54), was significantly enhanced at the invasion front of control tumors after LITT compared to hepatic resection. CONCLUSIONS: Our results suggest that LITT increases the immune response against untreated intrahepatic tumor tissue, which can lead to reduced tumor growth.

Laser induced thermotherapy (LITT) of experimental liver metastasis-detection of residual tumors using Gd-DTPA enhanced MRI.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the accuracy of Gd-DTPA MRI in the detection of recurrent tumor after laserinduced thermotherapy (LITT) of experimental liver metastases. STUDY DESIGN/MATERIALS AND METHODS: LITT was performed at different energy levels in VX-2 tumor-bearing rabbits (n = 80). MRI and histology were placed at 0, 24, 96 hours, and 14 days. Signal intensities were calculated of the transition between thermally damaged and undamaged tissue (transition zone = TZ) and of the surrounding tissue (reference zone = RZ). RESULTS: Tumor recurrence was seen in 47 animals. At 24 hours sensitivity, specificity and accuracy was 92, 100, and 95% in TZ and 23, 100, and 50% in RZ. At 14 days sensitivity, specificity and accuracy was 100, 11, and 60% in TZ and 100, 89, and 95% in RZ. CONCLUSIONS: Recurrence is best excluded in TZ at 24 hour and in RZ at 14 day with an accuracy up to 95%.