Tumor cell dissemination in a human colon cancer animal model: orthotopic implantation or intraportal injection?

BACKGROUND

The development of therapeutic strategies for treatment of metastasized colorectal carcinoma requires biologically relevant and adequate animal models generating both metastases and the dissemination of tumor cells.

METHODS

To prove the efficiency of orthotopic implantation concerning induction of minimal residual disease (MRD) colorectal cancer tissue from 10 patients was transplanted orthotopically into nude mice. In the intraportal injection model 1 x 10(6) HT-29 human colon cancer cells were injected. We investigated by histological studies and CK-20 RT-PCR the occurrence of hematogenous metastases and the dissemination of human colon cancer cells in bone marrow.

RESULTS

Following orthotopic implantation of human colon cancer tissue the lymph node and hepatic metastasis rates were low. MRD as reflected by CK-20 positivity of the bone marrow was present in 22.2%. The intraportal injection of 1 x 10(6) HT-29 human colon cancer cells produced hepatic metastases in up to 89% of all animals. The intraportal injection of 1 x 10(6) cells also generated MRD in the bone marrow in 63% of animals.

CONCLUSIONS

The intraportal injection model represents a biologically relevant and adequate animal model for the induction of both reproducible hepatic metastasis and MRD in the bone marrow. In this regard it seems to be superior to the orthotopic implantation model.

Improving laser-induced thermotherapy of liver metastases--effects of arterial microembolization and complete blood flow occlusion

INTRODUCTION

A prerequisite for an oncologically curative application of laser-induced thermotherapy (LITT) of liver metastases is complete tumor destruction. This increased effectiveness was achieved experimentally by combining LITT with interrupted hepatic perfusion. The aim of this study was to evaluate whether an interventional selective arterial microembolization might be as effective as complete blood flow occlusion using an open Pringle's maneuver.

PATIENTS AND METHODS

We included patients with unresectable colorectal liver metastases. LITT was performed without interrupted hepatic perfusion (control group) compared to LITT in combination with interrupted perfusion either by embolization of intraarterial degradable starch microspheres (DSM) (percutaneous access) or by complete hepatic inflow occlusion (Pringle's maneuver; open access). Online monitoring was performed using intraoperative ultrasound or MRI. Volumetric techniques were used to assess metastases and postinterventional lesions.

RESULTS

Fifty-six patients with 104 metastases (control group (25), DSM (37), and Pringle (42)) were treated. The preinterventional tumor volumes were significantly smaller than the postinterventional lesion volumes (control group: 9.8 vs. 25.3 cm3; DSM: 9.5 vs. 65.4 cm3; Pringle: 12.9 vs. 76.5 cm3). The morbidity rate was 21.4% without treatment-related mortalities. After 6 months follow-up, tumor recurrence was diagnosed in 6 patients (control group (4), LITT with DSM (1), and Pringle (1)).

CONCLUSIONS

Combining LITT with blood flow occlusion leads to a significant increase in lesion size. The application of DSM offers a safe and effective alternative to the open access with Pringle's maneuver. Compared to LITT-monotherapy, this modality achieves significantly larger thermal lesions with the need of fewer applications.

Multicenter pilot study of 5-fluorouracil, folinic acid, interferon alpha-2b and degradable starch microspheres via hepatic arterial infusion in patients with nonresectable colorectal liver metastases

BACKGROUND

It is necessary to establish therapeutic regimens for patients with nonresectable hepatic metastases of colorectal carcinoma. A new regional chemotherapy regimen was tested in a prospective study in three centers.

PATIENTS AND METHODS

An arterial port system was implanted in 95 patients. From January 1994 to March 1999, intra-arterial treatment was applied via the hepatic artery using 450 mg starch microspheres with 5 million IU recombinant interferon-alpha 2B, 500 mg/m2 folinic acid and 600 mg/m2 5-FU body surface for 5 days with a 14-day interval.

RESULTS

The tumor response rate was 70%. Median disease progression was 17 months, median survival 24 months. The subgroup analysis shows a significant advantage (p<0.00001) for patients with a liver tumor involvement of <25% and a median survival of 39 months compared to a tumor involvement of 25-50% (24 months) and >50% (14 months). Major toxicity problems were observed in 11%. However, there was no termination of therapy on account of these problems.

CONCLUSION

Intra-arterial chemotherapy with our new regimen was useful in patients with colorectal liver metastases who had only an intrahepatic tumor burden of <50%.

Prognostic value of nuclear survivin expression in oesophageal squamous cell carcinoma

Survivin, a new member of the family of apoptosis inhibitors, is expressed almost exclusively in proliferating cells, above all in cancers. Subcellular localisation and prognostic implications of the survivin protein have not yet been determined in oesophageal squamous cell carcinoma. The survival of 84 patients with oesophageal squamous cell carcinomas was correlated with the extent of immunohistochemical survivin expression in tumour cell nuclei. Tumours were scored positive when >5% cells stained positive. Patients were followed up for at least 5 years or until death. In normal oesophageal squamous cell epithelium, some cytoplasmic survivin expression was detected in the basal cells, whereas proliferating cells showed nuclear staining of survivin. Nuclear expression of survivin was also detected in 67 cancers (80%). The mean survival for patients of this group (28 months, range 20-36) was significantly less than that for patients without survivin expression in the tumour cell nuclei (108 months, range 62-154, P=0.003). Using univariate analysis, nuclear survivin expression (P=0.003), tumour depth (P=0.001), lymph node metastasis (P=0.003) and stage (P<0.001) were the best predictors of survival. In contrast, cytoplasmic survivin staining was noted in 53 (63%) tumours and had no prognostic relevance. In conclusion, the analysis of nuclear survivin expression identifies subgroups in oesophageal squamous cell cancer with favourable (survivin(-)) or with poor prognosis (survivin(+)). We suggest that the determination of nuclear survivin expression could be used to individualise therapeutic strategies in oesophageal squamous cell cancer in the future.

[Sigmoid diverticulitis. Surgical indications and timing]

Indication and time for surgery of diverticular disease are determined by the stage of the disease. Clinically pragmatic pretreatment staging is thus a prerequisite for stage-adapted therapy. The correct indication for surgery is also based on knowledge of the spontaneous disease course, its course after conservative and operative therapy and the individual risk factors for complicated diverticular disease. Surgery is not indicated for bland diverticulosis or uncomplicated diverticulitis. It is generally indicated, however, for acute complicated diverticulitis. Decisive in establishing the indication for surgery is therefore the precise pretherapeutic differentiation of complicated and uncomplicated diverticulitis. Depending on the type of complication and the clinical appearance, the time for surgery of acute complicated diverticulitis is fixed on an emergency or early elective basis following initial conservative and/or interventional therapy. Chronically recurrent diverticulitis is likewise an indication for surgery. In terms of timing, an elective interval operation is best after the second inflammatory episode but should already be performed after the first one in risk groups, e.g. immunosuppressed patients.

[Radical resection of colorectal carcinoma in the oldest old]

INTRODUCTION

The percentage of old people with colorectal cancer is steadily increasing in Western industrialized countries. Since there are only a few reports on the extent of surgery, it is unclear whether radical lymphadenectomy can also be safely performed as a standard operation in this age group.

METHODS

In a prospective study, we analyzed all patients who were > or = 80 years of age at the time of surgery and who were submitted to surgery between 1/95 and 12/00 due to a colorectal carcinoma. Target parameters were postoperative morbidity and mortality.

RESULTS

Fifty-seven of 665 patients (8.6%) were > or = 80 years of age. The median age was 85 years (range: 80-92). The gender ratio was 1:1.6 (G:E). Palliative surgery was performed in 19 of 57 patients. The remaining 38 patients underwent curative radical lymphadenectomy; 32 were elective and 6 emergency procedures. Mean ASA scores were 2.1 +/- 0.3 and 2.5 +/- 0.6. The following operations were performed: 13 right-sided and 15 left-sided hemicolectomies, 5 rectal resections, 3 rectal extirpations and 2 Hartmann's procedures. Two anastomotic insufficiencies (6%) had a complication-free course after revision. The rate of major surgical complications was 11%, that of internal complications 16%. Three patients (8%) died, one after an elective procedure and two after emergency laparotomy. One of the latter was an 89-year-old woman who refused to undergo a revision due to bleeding after Hartmann's procedure. Pneumonia and myocardial infarction were the cause of death in the other two patients.

CONCLUSION

Radical resection can be safely performed even at an advanced age. Since age-corrected survival is comparable to that of younger patients, surgery should be performed in the elderly under elective conditions according to oncological criteria.

Laser-induced thermotherapy: intra- and extralesionary recurrence after incomplete destruction of experimental liver metastasis

PURPOSE

The aim of this study was to determine the energy (J/mm3 tumor volume) and temperature required for a complete laser-induced thermotherapy (LITT) of experimental liver tumors, and to find out causes and areas of local recurrence followed by incomplete treatment.

METHODS

In VX-2 tumor-bearing rabbits LITT was performed using neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (1064 nm) with a diffuser-tip applicator and a temperature feedback system. The animals were randomized into four groups (n = 20) that differed in the target temperature at the tumor border as follows: 45 degrees C, 50 degrees C, 55 degrees C and 60 degrees C. The target temperature was held for 10 min constant. Histologic examination (hematoxylin and eosin [H and E], nicotinamide adenine dinucleotide phosphate [NADPH]-dehydrogenase) was performed at 0 h, 24 h, 96 h, and 14 days after LITT.

RESULTS

The pretreatment tumor volume of 2191 +/- 61 mm3 was the same for all groups (p > 0.05). Energy up to target temperature and total energy required, lesion size, and the rate of incomplete tumor ablation (recurrences) are listed below (ap < 0.05, Kruskal-Wallis test). Histologically, two forms of local recurrences could be differentiated intralesionary and extralesionary.

CONCLUSIONS

To achieve complete in situ ablation under the given conditions, it is necessary to apply laser energy of 3 J/mm3 tumor volume. A minimum temperature of 60 degrees C on the tumor border presumed an application of 10 min. Recurrence was found outside the coagulation zone (extralesionary) and in high vascularized areas within the coagulation zone (intralesionary).

Continuous changes in the optical properties of liver tissue during laser-induced interstitial thermotherapy

BACKGROUND AND OBJECTIVE

Laser-induced thermotherapy (LITT) is a promising treatment for irresectable liver tumors. To predict the effects of laser applications and to optimize treatment planning in LITT, it is essential to gain knowledge about light distribution in tissue, tissue optical properties (absorption, scattering, anisotropy, penetration depth), and their continuous changes during therapy.

STUDY DESIGN/MATERIALS AND METHODS

Measurements of optical properties were performed with a double integrating-sphere system and a laser diode (830 nm). Porcine liver tissue samples were examined in a native state (35 degrees C) and after exposure to different temperatures (45 degrees C to 80 degrees C).

RESULTS

Rising temperature was accompanied by a decrease in the absorption coefficient and anisotropy factor and an increase in the scattering coefficient. These changes were only significant in the temperature range of 50 degrees to 65 degrees C (P < 0.01). The optical penetration depth decreased from 3.1mm in the native state to 1.7mm at 65 degrees C (P < 0.01). Above 65 degrees, there was no significant change in the tissue optical properties.

CONCLUSIONS

The optical properties of liver tissue change significantly under the influence of tissue heating, resulting in a decreased optical penetration depth. These changes occur mainly in the temperature range of 50 degrees C to 65 degrees C, corresponding to protein denaturation. To ensure a safe and effective procedure, an adjustment of the laser power to the actual penetration depth is recommended during therapy.

Phase-inversion sonography during the liver-specific late phase of contrast enhancement: improved detection of liver metastases

OBJECTIVE

The purpose of our study was to assess whether phase-inversion sonography during the late, liver-specific phase of contrast enhancement using Levovist improves the detection of hepatic metastases relative to unenhanced conventional B-mode sonography.

SUBJECTS AND METHODS

Sixty-two patients were studied with unenhanced B-mode sonography and phase-inversion sonography 2.5 min after the injection of Levovist. All patients underwent one reference examination (CT, MR imaging, or intraoperative sonography). The conspicuity, number, size, and distribution of metastases before and after contrast administration as judged by a sonographer (who was unaware of other imaging findings) were compared with each other and with reference imaging.

RESULTS

The conspicuity of metastases was improved by contrast-enhanced phase inversion in 94% of patients. Thirty-nine patients showed metastases on reference imaging; 36 of these were positive on baseline sonography and 38 on phase-inversion sonography. Phase-inversion sonography showed more reference imaging-confirmed metastases than baseline sonography in 28 patients (45%). The average number of confirmed metastases per patient was 3.06 for baseline sonography and 5.42 for contrast-enhanced phase-inversion sonography (p < 0.01). The average sensitivity for detecting individual metastases improved from 63% to 91%. Metastases of less than 1 cm were shown in 14 patients on baseline sonography, in 24 patients on phase-inversion sonography, and in 26 on reference imaging. Both sonographic techniques showed false-positive lesions in six patients.

CONCLUSION

Contrast-enhanced phase-inversion sonography in the liver-specific phase of contrast enhancement using Levovist provides a marked improvement in the detection of hepatic metastases relative to unenhanced conventional sonography, without loss of specificity. Phase-inversion sonography was particularly advantageous in detecting small metastases and may be a competitive alternative to CT and MR imaging.

MR-guided interstitial laser-induced thermotherapy of hepatic metastasis combined with arterial blood flow reduction: technique and first clinical results in an open MR system

The feasibility and safety of percutaneous laser-induced thermotherapy (LITT) of liver metastases in an open low-field magnetic resonance imaging (MRI) system combined with microsphere-modulated blood flow reduction were tested. Nd:YAG laser therapy with an internally cooled laser applicator was performed under local anesthesia on 20 patients with 34 liver metastases. To increase the effectiveness of LITT, degradable starch microspheres were injected into the proper hepatic artery through an MR-visible catheter initially inserted under fluoroscopy. Near real-time imaging was used for positioning the laser applicator. A T1-weighted gradient-echo breath-hold sequence was used for catheter localization and temperature monitoring. The volumes of the liver metastases and the thermonecroses were determined. MRI-guided LITT could be performed in all patients with no clinically relevant complications. Intraprocedural imaging underestimated the extent of thermonecrosis. In conclusion, percutaneous LITT of liver metastases after injection of starch microspheres is both technically feasible and safe in an open MRI system. J. Magn. Reson. Imaging 2001;13:31-36.

Optical properties of native and coagulated porcine liver tissue between 400 and 2400 nm

BACKGROUND AND OBJECTIVE

Laser induced thermotherapy (LITT) is a promising treatment for irresectable liver tumors. For predicting the effects of laser applications and optimizing irradiation planning in LITT, knowledge about light distribution in tissue, optical tissue properties (absorption, scattering, anisotropy, penetration depth) and their changes due to thermal denaturation is indispensable.

STUDY DESIGN/MATERIALS AND METHODS

The optical parameters in healthy porcine liver were determined in the native state and after thermal coagulation using a double integrating sphere system in the wavelength range of 400-2400 nm.

RESULTS

Optical parameters showed significant fluctuations in the examined wavelength range mainly due to the water and hemoglobin content in the tissue. The greatest optical penetration depth of 7.46 mm was achieved at 1070 nm. After thermal coagulation, a clear increase in scattering and a slight decrease in absorption was found, which results in a decreased optical penetration depth.

CONCLUSIONS

In order to ensure a safe and effective procedure, an adjustment of the laser power to the decreasing penetration depth is recommended during therapy. These results provide a better understanding of laser-tissue interaction and may be helpful to investigators in the field of light dosimetry in liver tissue.

MR-guided interstitial laser-induced thermotherapy of hepatic metastasis combined with arterial blood flow reduction: technique and first clinical results in an open MR system

The feasibility and safety of percutaneous laser-induced thermotherapy (LITT) of liver metastases in an open low-field magnetic resonance imaging (MRI) system combined with microsphere-modulated blood flow reduction were tested. Nd:YAG laser therapy with an internally cooled laser applicator was performed under local anesthesia on 20 patients with 34 liver metastases. To increase the effectiveness of LITT, degradable starch microspheres were injected into the proper hepatic artery through an MR-visible catheter initially inserted under fluoroscopy. Near real-time imaging was used for positioning the laser applicator. A T1-weighted gradient-echo breath-hold sequence was used for catheter localization and temperature monitoring. The volumes of the liver metastases and the thermonecroses were determined. MRI-guided LITT could be performed in all patients with no clinically relevant complications. Intraprocedural imaging underestimated the extent of thermonecrosis. In conclusion, percutaneous LITT of liver metastases after injection of starch microspheres is both technically feasible and safe in an open MRI system. J. Magn. Reson. Imaging 2001;13:31-36.

Optical properties of native and coagulated porcine liver tissue between 400 and 2400 nm

BACKGROUND AND OBJECTIVE

Laser induced thermotherapy (LITT) is a promising treatment for irresectable liver tumors. For predicting the effects of laser applications and optimizing irradiation planning in LITT, knowledge about light distribution in tissue, optical tissue properties (absorption, scattering, anisotropy, penetration depth) and their changes due to thermal denaturation is indispensable.

STUDY DESIGN/MATERIALS AND METHODS

The optical parameters in healthy porcine liver were determined in the native state and after thermal coagulation using a double integrating sphere system in the wavelength range of 400-2400 nm.

RESULTS

Optical parameters showed significant fluctuations in the examined wavelength range mainly due to the water and hemoglobin content in the tissue. The greatest optical penetration depth of 7.46 mm was achieved at 1070 nm. After thermal coagulation, a clear increase in scattering and a slight decrease in absorption was found, which results in a decreased optical penetration depth.

CONCLUSIONS

In order to ensure a safe and effective procedure, an adjustment of the laser power to the decreasing penetration depth is recommended during therapy. These results provide a better understanding of laser-tissue interaction and may be helpful to investigators in the field of light dosimetry in liver tissue.

Esophageal hypermotility associated with intramural pseudodiverticulosis. Primary esophageal disease or epiphenomena?

Esophageal intramural pseudodiverticulosis is a very rare disease of unclear etiology. The clinical picture is characterized by progressive dysphagia. Because of its frequent association with alcohol abuse and subsequent weight loss, it must be differentiated reliably from esophageal carcinoma. The diagnosis is established by the characteristic detection of multiple intramural contrast accumulations in the barium esophagogram. Additional endoscopic and endosonographic confirmation and histological examination are required to exclude a malignant tumor. Moreover, associated diseases are almost always present and should also be diagnosed by pH-metry, cytology, and esophageal manometry. Good and long-lasting therapeutic success can be achieved by bouginage of the stenosis with concomitant treatment of the associated esophageal diseases. Based on two case reports of patients with this disease, we discuss the unusual association with esophageal hypermotility as well as the symptoms, clinical course, therapy, and pathogenesis of the disease.

Optical properties of native and coagulated human liver tissue and liver metastases in the near infrared range

BACKGROUND AND OBJECTIVE

Knowledge about optical parameters and the resultant light distribution in laser-treated tissue is important for predicting the effects of laser-induced thermotherapy of liver metastases (LITT).

MATERIALS AND METHODS

The absorption and scattering coefficients as well as the anisotropy factors and the optical penetration depths of human liver tissue and colorectal liver metastases were determined at 850, 980, and 1,064 nm under native and thermocoagulated conditions.

RESULTS

Liver metastases had a lower anisotropy factor, absorption, and scattering coefficient than healthy liver (P < 0.01), resulting in a significantly higher optical penetration depth in metastatic tissue. Coagulation significantly changes the optical parameters by reducing the optical penetration depth in both tissue types (P < 0.01).

CONCLUSIONS

A greater optical penetration depth in metastatic tissue is advantageous for LITT, since larger tumor volumes can be coagulated. At the same time, an adjustment of the application parameters during LITT is necessary to achieve optimal therapeutic success.

Interstitial laser coagulation: evaluation of the effect of normal liver blood perfusion and the application mode on lesion size

BACKGROUND AND OBJECTIVE

The effect of temporarily interrupted hepatic blood flow and multiple-fiber application on necrosis volume in interstitial laser coagulation (ILC) was investigated.

STUDY DESIGN/MATERIALS AND METHODS

Single- and multiple-fiber ILC were performed in porcine livers with normal as well as interrupted perfusion. Temperatures were determined. Lesions were measured and studied by light microscopy 4 hours post-treatment.

RESULTS

ILC with multiple-fiber application led to significantly greater individual lesion volumes (3.7 +/- 0.5 cm3) than single-fiber application (2.5 +/- 0.5 cm3) (P < .01). The interruption of hepatic perfusion led to a significant increase in lesion volume with single- (7.5 +/- 1.0 cm3) as well as multiple-fiber application (12.6 +/- 2.2 cm3) (P < .01). Superposition of the lesions in the multiple-fiber application mode was only determined with interrupted perfusion (total volume: 50.3 +/- 6.6 cm3).

CONCLUSION

Interruption of hepatic perfusion increases lesion volumes significantly. ILC for treating liver tumors should preferably be performed by application routes that permit temporary interruption of hepatic perfusion.

[Laser-induced thermotherapy (LITT) for liver metastasis in an open 0.2T MRI]

OBJECTIVE

To test the feasibility and safety of the laser-induced thermotherapy (LITT) for liver metastases in open MR imaging system operating at 0.2 Tesla.

METHOD

Laser therapy using the Nd:YAG laser was performed on 25 patients with a total of 41 liver metastases. An open low-field MRI scanner was used for puncture, positioning of the laser applicator, and monitoring the therapy. A true FISP sequence was used to track the puncture in close to real-time. Localization diagnostics and temperature monitoring were aided by T1-weighted gradient echo sequences in the breath-holding technique. In the first follow up after 24-48 hours, a contrast-enhanced T1-weighted gradient-echo sequence was performed in an MRI scanner at 1.5T. The pre-, intra- and postinterventional volumes of the liver metastases as well as the thermolesions and the thermonecroses were determined.

RESULTS

LITT in an open MRI system was technically feasible in all patients with no clinically relevant complications. The mean volumes of the thermolesions measured during intervention in low-field MRI were lower than the volumes of the thermonecroses measured after intervention in high-field MRI.

CONCLUSION

The technique presented here of laser-induced thermotherapy for liver metastases in an open MRI system is technically feasible and safe.

Laser-induced thermotherapy combined with hepatic arterial embolization in the treatment of liver tumors in a rat tumor model

OBJECTIVE

To assess the effect of combined laser-induced thermotherapy (LITT) and hepatic arterial embolization with degradable starch microspheres (DSM) on tumor response and intrahepatic temperature distribution in rats with liver tumors.

SUMMARY BACKGROUND DATA

Laser-induced thermotherapy is a promising in situ ablation technique for malignant liver tumors. However, clinical use is still limited, mainly because of the small size of the inducible coagulation necroses. This results in insufficient tumor destruction.

METHODS

Colon carcinoma CC531 was implanted in 60 WAG rat livers. Fourteen days later, a silicon catheter was implanted in the hepatic artery for DSM administration. Tumors were exposed to 1064 nm Nd:YAG laser light at 2 watts for 10 minutes from a diffuser tip applicator placed in the tumor. The animals were randomized into a sham-operated control (group I) and three test groups. Group II received DSM alone, group III received LITT alone, and group IV received DSM + LITT. Tumor control was examined 1, 7, and 14 days after treatment.

RESULTS

A complete tumor remission was achieved in all rats treated with LITT + DSM (group IV). In contrast, tumor progression was seen in animals treated with LITT alone (group III) or DSM alone (group II), as well as in the sham-operated controls (group I).

CONCLUSIONS

The authors' results suggest that the combination of LITT and DSM considerably increases the efficacy of LITT in the treatment of liver metastases in the rat.

[Thermal laser dosimetry in treatment of liver tumors--correlation of optical tissue parameters with in vivo temperature distribution in VX-2 tumors and healthy liver tissue]

Optical properties and in-vivo temperature distribution during laser-induced thermotherapy in normal and tumorous rabbit liver were correlated. Lower absorption and scattering led to a higher optical and thermal penetration depth in the tumor tissue.

[Endoscopic cholecystectomy as cost assessment--still a learning intervention?]

Economic considerations are putting increasing pressure on surgical departments to avoid intra- and postoperative complications and thus additional costs. Under this aspect, it was investigated whether laparoscopic cholecystectomy is a suitable training intervention for young prospective surgeons. These physicians in advanced training did not have a higher intra- or postoperative complication rate in a preselected patient population than senior physicians or specialists. The additional costs per surgical intervention due to longer operation times required by young physicians were acceptable so that laparoscopic cholecystectomy as a training intervention for young colleagues can be justified.

[Optimized laser-induced thermotherapy in treatment of liver metastases of colorectal carcinomas, an interdisciplinary responsibility--a clinical study]

In a clinical study, it was investigated whether local tumor control is attainable with laser-induced thermotherapy (LITT) in the treatment of colorectal liver metastasis tumors. Local control of tumor growth was obtainable in completely hyperthermic tumors. Due to the small and inhomogeneous patient population (n = 32), an assessment of the method regarding prognostic gain for the patient is not possible in such a short follow-up period.

[Value of magnetic resonance tomography in preoperative staging of stomach carcinoma]

The value of MRI as a preoperative staging procedure in stomach carcinomas compared to CT and endosonography was examined in a prospective study and correlated with the pathohistological results. MRI showed better correlation with the pathohistological evaluation at the T3, T4, N and M stage than the other two test procedures. MRI is thus a suitable staging procedure for stomach carcinomas.

[Rediscovered techniques--Janeway laparoscopic gastrostomy in comparison with Witzel fistula]

We present the results of 20 patients with a laparoscopic gastrostomy according to Janeway. The laparoscopic gastrostomy was associated with less operation time, less analgetic consumption, and less discomfort in comparison to 24 patients with a Witzel fistula.

Technology for in situ ablation by laparoscopic and image-guided interstitial laser hyperthermia

The technical requirements have been fulfilled for the reliable clinical application of laser-induced thermotherapy for treating liver tumors. Laparotomy as well as percutaneous and laparoscopic access modes are available for this method. Thus, laser-induced thermotherapy is a true minimally invasive procedure for treating liver metastases. Presently, it is not possible to make a final assessment on the prognostic value of laser-induced thermotherapy in the treatment of liver tumors. However, recently published data justify the scheduling of a randomized study comparing laser-induced thermotherapy with standard surgical liver resection. In this article, thermobiological and technical principles as well as the different types of application modes for this method are described.

[Laser-induced thermotherapy. Technical prerequisites for treatment of malignant liver tumors]

Laser-induced thermotherapy is an in situ ablation method for the local treatment of liver tumors. The basic prerequisite for induction of adequate treatment volumes for clinical use was the development of a thermostable application system. In an ex vivo test series, the specially developed application system (diffuser tip) with 5760 J had a higher thermic loading capacity than the Ringmode applicator with 4200 J, thus enabling the induction of significantly larger lesions with a volume of 7.6 cm3. The results of a further in vivo test series demonstrated that the lesions were subject to a four-phase connective-tissue organization within a 6-month period. Furthermore, the same laser energy (4200 J) was associated with a significantly lower lesion volume of 2.5 cm3 in the in vivo than in the ex vivo test series. The influence of liver perfusion on the inducible lesion volume was examined in a further animal experimental study. By temporarily interrupting hepatic blood perfusion (Pringle's maneuver) during laser application, the effective volume could be increased to 50.3 cm3 (P < 0.01) using an optical beam splitter. These results show that the technical prerequisites for reliable clinical application of laser-induced thermotherapy have been fulfilled.

Laparoscopic gastrostomy according to Janeway

Percutaneous endoscopic gastrostomy is not suitable for all patients requiring gastrostomies. Patients with endoscopically impassable tumors require a safe and effective alternative procedure for paraesophageal alimentation. We present the surgical technique and results of the laparoscopic gastrostomy according to Janeway. Using an endoscopic stapling device a gastric tube is created from a stomach fold, led out through the trocar site, and fixed to the skin in the left upper quadrant. Via an inserted catheter enteral alimentation can be performed intermittently since the gastrostoma is continent. Between July 1995 and November 1996 laparoscopic gastrostomy was performed in 15 patients (10 male, five female) with tumors in the pharynx or esophagus. Mean operation time was 35 min. One stoma necrosis developed; the other postoperative courses were complication-free. All gastrostomies were continent. Laparoscopic gastrostomy is easy to perform and involves minimal discomfort and complications for the patient.

[Preoperative routine chest x-ray: expensive and of little value]

In a retrospective analysis, we examined the findings of 3156 preoperative routine chest X-rays to define the indication of this cost-intensive examination. Pathological findings were seen only in 4% of all patients with no preexisting disease and in about 20% of patients with malignoma. Chest radiography is not routinely indicated in otherwise healthy patients, but should be performed if malignant disease is present.

[Monstrous pseudocyst of the adrenal gland]

We report on a 64-year-old patient with a huge adrenal pseudocyst. These are rare cystic lesions of the adrenal gland with an unclear etiology. Recent studies suggest that the majority of adrenal pseudocysts are of vascular origin. All cystic masses in the epigastric region have to be considered in the differential diagnosis. The treatment of choice is surgical removal.

[Overexpression of B7-1 amd B7-2 by LFA-1 positive lymphocytes in chronic inflammatory bowel diseases]

The B7/CD28 pathway is essential for initiating antigen-specific T-cell activation. LFA-1 (CD11a/CD18) is required for sufficient migration into inflammatory tissue. The aim of this study was to evaluate the role of B7 and LFA-1 in inflammatory bowel disease. Immunohistological single and double staining (PAP/APAAP) with monoclonal antibodies against HLA I/II, CD4, CD8, CD28, B7-1, B7-2, LFA-1 and CD68 were performed in tissue samples from patients with crohn's disease (n = 15), ulcerative colitis (n = 14), colorectal carcinoma (n = 5) and FAP (n = 3). The expression of B7-1 and B7-2 was generally much higher in ulcerative colitis and crohn's disease than in colorectal carcinoma and FAP. In crohn's disease multinucleated gigant cells in the granulomas express B7-1 and B7-2. Double staining showed a higher B7-1/B7-2 coexpression for CD4+ than for CD8+ T cells. In colitis ulcerosa and crohn's disease LFA-1 positive leucocytes showed a high coexpression of B7-1 and B7-2 in contrast to CD68 positive macrophages. These data suggest that overexpression of B7-1 and B7-2 on LFA-1 positive Leucocyts seems to play an important role in the pathogenesis of inflammatory bowel disease.

[Significant modification of the hyperthermic effect by starch microspheres (Spherex) of laser-induced hypertheria in the rat liver metastasis model]

This experimental study in an animal liver metastasis model (adenocarcinoma) investigated whether the "cooling effect" can be eliminated by temporary embolization with starch microspheres (Spherex) and the hyperthermic efficiency was improved. In this connection, groups of 15 test animals were treated with LITTmono, Embolizationmono or LITTembolization. In the LITTembolization group, 1/15 animals had vital tumor tissue after 24 h, 7 and 28 days, but tumor growth was found in the other 2 groups in 13/15 (LITTmono) and 14/15 (Embolization(mono)). These results demonstrate that the application of starch microspheres led to a significant increase in the hyperthermic effect of LITT under the selected testing conditions.

Experimental study of laparoscopic laser-induced thermotherapy for liver tumours

BACKGROUND

Laser-induced thermotherapy is a minimally invasive method that can be applied percutaneously or during laparotomy for the treatment of malignant liver tumours. The aim of this experimental study was to investigate whether the laparoscopic approach is suitable for laser-induced thermotherapy. Laparoscopic ultrasonography was tested as an aid to intrahepatic positioning of the applicators as well as for online monitoring during application.

METHODS

A neodymium yttrium-aluminium-garnet laser was used to induce thermal lesions in the healthy liver of ten German hybrid pigs. The length of application was 840 s. Forty applications were performed with normal hepatic blood flow and 40 with hepatic blood flow interrupted by means of a laparoscopic Pringle's manoeuvre.

RESULTS

A total of 20 simultaneous multifibre applications with 80 single applications were performed. Thermal necrosis with a total volume of 50.3 cm3 was induced with high precision when hepatic blood flow was interrupted temporarily. When hepatic blood flow was normal, the total volume of thermal necrosis was only 14.6 cm3 (P < 0.01). Laparoscopic ultrasonography was used successfully as an aid for exact applicator positioning and for online monitoring. Method-related complications did not occur.

CONCLUSION

The laparoscopic approach is an attractive means of application for laser-induced thermotherapy and it seems that clinical testing is justified.

[Hemobilia in cholecystolithiasis as a rare cause of massive upper gastrointestinal hemorrhage]

Haemobilia is defined as bleeding into the hepatobiliary system caused by a pathologic connection between blood vessels and biliary ducts. A rare cause of haemobilia is gallstone disease, with only 52 reported cases in the literature. The haemobilia is characterised by the classical triad: jaundice, colicky pain in the right upper quadrant and signs of gastrointestinal bleeding. Diagnosis can be made with endoscopic procedures and with angiography of the coeliac trunk, which has the highest sensitivity in localisation of bleeding source. The therapy of choice is cholecystectomy. We report the case of a patient with massive gastrointestinal haemorrhage caused by a solitary gallstone and present the diagnostic and therapeutic management of this disease, which is accompanied by a high mortality.

[The fully implantable minimally invasive hepatic artery catheter for locoregional chemotherapy of nonresectable liver metastases in defective conventional implanted therapy catheters]

Dysfunction of arterial access devices used in association with intra-arterial chemotherapy for the treatment of unresectable liver metastases usually requires stopping the therapy or relaporotomy and reimplantation of a new arterial catheter. In this article our initial experience of a new technique, the so-called MIAH catheter (minimally invasive hepatic artery catheter) in 36 patients (age 37-78 years) are reported. The MIAH catheter was percutaneously inserted into the subclavian artery under sonographic guidance and advanced via the descending aorta selectively into the hepatic artery. Finally it was connected to a totally implantable pump. There were no deaths related to the operation. Operative or early complications occurred in 5 cases (13.8%); late complications were seen in 13 patients (36.1%). Nevertheless continuation of intra arterial chemotherapy was possible in all cases. In cases of dysfunction of conventional arterial access devices the MIAH catheter makes it possible to continue intra-arterial chemotherapy without requiring laporotomy.

Primary malignant melanoma of the oesophagus

We report the case of a 74-year-old female patient in whom a primary malignant melanoma of the oesophagus was detected at the time of investigation of phlebothrombosis. Therapy of choice for this extremely rare tumour is radical surgical resection of the oesophagus. Even after surgical resection, primary oesophageal melanomas have a very poor prognosis. According to the present state of knowledge, it remains unclear to what extent the prognosis could be improved by adjuvant therapeutic procedures with radiotherapy or chemotherapy and immunostimulation.

[Vascular malformations in the gastric fundus as a rare cause of fundus variceal hemorrhage]

In the differential diagnosis of the aetiology of portal hypertension arterio-portal fistulas as a rare cause have to be taken in account. The case of a 70-year-old male presenting with massive upper gastrointestinal bleeding secondary to gastric varices caused by a vascular malformation of the gastric fundus is reported and the problem of non-cirrhotic portal hypertension is discussed. In case of variceal bleeding aetiology of portal hypertension has to be clarified exactly before any kind of therapeutic intervention to avoid therapeutic pitfall.

[The esophageal cyst--a rare congenital abnormality]

Esophageal cysts are among the embryonic malformations of the gastrointestinal tract. They develop from persisting diverticulum-like evaginations of the embryonic esophagus. The esophageal cyst is usually asymptomatic and is frequently diagnosed as an incidental finding. Since, however, a clear differentiation from malignancies is not possible with conventional diagnostic procedures. Surgical treatment is advisable in these cases.

Pathogenesis of the mucosal hyperplasia in self-filling blind loops of rat jejunum: a morphometric study in germ free animals

Bacterial overgrowth and high intraluminal concentrations of deconjugated bile acids are thought to be responsible for mucosal hyperplasia in self-filling blind loops of rat jejunum. To investigate this hypothesis further we have assessed the three dimensional architecture of these loops created in germ free animals without or with di- or mono-association of different bacterial species. It was found that mucosal hyperplasia develops in the absence of any bacterial contamination and that bacterial association does not lead to a more pronounced mucosal proliferation. This implies that other mechanisms provoke this morphological phenomenon. Increased bulk contents in these loops or immunological events are probably the most likely explanation.

[Qualitative and quantitative detection of bacterial flora in experimental blind loop syndrome of the rat]

In the blind loop syndrome bacterial overgrowth--accompanied by an increase in bile acid deconjugation--is thought to be responsible for the observed morphological alterations of the small intestinal mucosa with its concomitant malabsorption syndrome. Since in this chain of events the bacterial overgrowth is of primary importance, we have performed a complete qualitative and quantitative evaluation of the intraluminal flora in rats with surgically created self-filling blind loops. The results show a significant increase in bacteria of the aerobic growing genera E. coli and Streptococcus (Enterococcus), and of the anaerobic growing genus Bacteroides, in one single rat also of the genera Lactobacillus/Bifidobacterium. In order to elucidate which strains of bacteria are predominantly responsible for the morphological and functional alterations observed in the stagnant loop syndrome, germ-free rats with self-filling blind loops should be contaminated selectively with bacteria of these genera.

[Significance of deficient bacterial colonization in the pathogenesis of mucosal lesions in experimental blind loop syndrome]

A complete evaluation of the bacterial flora in jejunal self-filling blind loops was performed. The results show a significant increase in bacteria of the genera E. coli, Streptococcus and Bacteroides. In further experiments, jejunal self-filling blind loops were created in germ-free animals. In spite of the germ-free state the mucosa displayed marked hyperplasia. The same was true when the blind loops had been contaminated with aerobic bacteria. These results demonstrate that other factors in addition to bacterial overgrowth contribute to the mucosal damage observed in self-filling blind loops.