| 1. |
- Ivarsson, K, et al.
(author)
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Feedback interstitial diode laser (805 nm) thermotherapy system: Ex vivo evaluation and mathematical modeling with one and four-fibers
- 1998
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In: Lasers in Surgery and Medicine. - 0196-8092. ; 22:2, s. 86-96
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Journal article (peer-reviewed)abstract
- Background and Objective: In this study a newly developed microprocessor controlled power regulation and thermometry system integrated with a diode laser (805 nm wavelength) was evaluated with respect to temperature distribution, effectiveness of regulation, and ability to predict temperature distributions by computer simulation. Study Design/Materials and Methods: Experiments were performed in ground bovine muscle using either a single laser fiber or four-fibers. The target temperature at one (feedback) thermistor, placed 5 mm from one of the laser fibers, was set to 50 degrees C and was maintained by means of stepwise power regulation. The temperature distribution was monitored using multiple thermistor probes. A numerical model based on the bioheat equation was used to calculate the temperature distributions. Results: Temperature regulation was excellent with a tendency towards better regulation in the four-fiber than in the single-fiber experiments. Agreement between calculated and measured temperatures was good. The coagulated (>55 degrees C) and hyperthermic (>45 degrees C) volumes were 6 and 10-11 times larger, respectively, with four-fibers than with a single fiber. Conclusion: It is concluded that the stepwise power regulation system was efficient in maintaining a stable target temperature. The results indicate that the system can produce lesion volumes adequate for treating a relatively large tumor in a single session and that computer simulation may be useful for predicting temperature distribution. (C) 1998 Wiley-Liss, Inc.
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| 2. |
- Möller, P. H., et al.
(author)
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Comparison between interstitial laser thermotherapy and excision of an adenocarcinoma transplanted into rat liver
- 1998
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In: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 77:11, s. 1884-1892
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Journal article (peer-reviewed)abstract
- The aim of this study was to compare interstitial laser thermotherapy with excision of a liver tumour. A dimethylhydrazine-induced adenocarcinoma was transplanted (implanted if not stated otherwise) into the left lateral lobe of the rat liver, and treatment was performed 8 days later. In the main experiment, rats were treated with resection of the tumour-bearing robe or underwent interstitial laser thermotherapy, which was performed at a steady-state temperature of 46°C for 30 min, 3 mm from the tumour margin. The incidence and extent of intraperitoneal spread was smaller after laser thermotherapy than after resection of the tumour-bearing lobe, with no difference in local control. Metastatic spread after resection of the median liver robe was similar to that observed after sham procedures for thermotherapy or resection, suggesting that the advantage of thermotherapy was not due to a difference in surgical trauma. Additional studies showed that laser thermotherapy reduced intraperitoneal spread when treatment was suboptimal or in a tumour inoculation model and suggested that immunological mechanisms might be involved. It is concluded that interstitial laser thermotherapy reduces spread of liver tumour compared with resection.
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| 3. |
- Ohlsson, B., et al.
(author)
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Dearterialization of colorectal liver cancer : Institutional experience
- 1999
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In: Digestive Surgery. - : S. Karger AG. - 0253-4886 .- 1421-9883. ; 16:3, s. 229-235
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Journal article (peer-reviewed)abstract
- Background/Aims: Preliminary clinical trials have suggested that dearterialization (interruption of arterial blood supply) is beneficial to patients with liver tumours. The aim of this report was to review the outcome of all patients undergoing dearterialization for colorectal liver metastases and to analyze whether refinement of the technique was followed by improvement in outcome. Methods: Retrospective review of 57 patients undergoing temporary (16 h) dearterialization during 1972-1984 (n = 24) or repeated transient dearterialization (1-2 h once or twice daily) during 1985-1995 (n = 33). Results: The median survival after start of treatment was 1.1 years, and the 5-year survival rate was 0%. There was no significant difference in survival between temporary and repeated transient dearterialization. Liver tumour volume and extrahepatic metastases varied negatively with survival. The temporary dearterialization procedure was followed by hepatic or intra-abdominal abscess formation in 6 patients (24%), leading to postoperative death in 2 patients (operative mortality 8%). Complications after repeated transient dearterialization were related mainly to technical problems with the occluder device. Conclusion: Although this was not a randomized study, it appears that dearterialization is of no benefit in colorectal liver cancer.
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| 4. |
- Sturesson, C, et al.
(author)
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Changes in local hepatic blood perfusion during interstitial laser-induced thermotherapy of normal rat liver measured by interstitial laser Doppler flowmetry
- 1999
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In: Lasers in Medical Science. - : Springer Science and Business Media LLC. - 0268-8921 .- 1435-604X. ; 14:2, s. 143-149
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Journal article (peer-reviewed)abstract
- Interstitial laser Doppler flowmetry was used to measure the effect of interstitial laser-induced thermotherapy on local blood perfusion in normal rat liver in the peripheral treatment region elevated to hyperthermic temperatures. The Nd:YAG laser emitting at 1064 nm was utilised as heat generation source. The plane-cut tip of an optical fibre was placed in the middle of the exteriorised left liver lobe. Blood perfusion and temperature were measured in the liver parenchyma 4 mm from the laser fibre. The temperature at the location of the liver temperature sensor was maintained at 41 or 44 degrees C during 30 min by regulating the power of the heating laser. The laser Doppler signal was recorded during and after heat treatment, for a total time of 60 min. At 41 degrees C, a significant increase in perfusion up to 1.3 times the initial value was observed 2-16 min after start of treatment. At 44 degrees C, perfusion decreased continuously during and after treatment, and was significantly different from control 40 min after start of treatment. The results may be valuable in assessing the thermal response of tissues surrounding the target in interstitial laser-induced thermotherapy of liver tumours during conditions of normal blood flow.
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| 5. |
- Tranberg, K. G., et al.
(author)
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The YAG laser and Wallstent endoprosthesis for palliation of cancer in the esophagus or gastric cardia
- 1995
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In: Hepato-Gastroenterology. - 0172-6390. ; 42:2, s. 139-144
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Journal article (peer-reviewed)abstract
- The need for frequent retreatment is a disadvantage of using endoscopic laser therapy (ELT) alone for palliative treatment of esophageal carcinoma. In this prospective study, therefore, we investigated the potential and feasibility of combining ELT with a self-expanding metallic stent (Wallstent). Twelve patients received ELT followed by stent placement (stent group) and were compared with 39 patients receiving ELT alone (ELT group). Swallowing ability was similar in the two groups. About one-third of the patients who had a short life expectancy, did not appear to benefit from stenting, whereas the interval between retreatments was prolonged by a factor of 2-4 in the remaining patients. Median survivals were 5.5 (range 1.0-23.5) months in patients with stents, and 4.5 (range 1.2-24.6) months in patients without stents. There were few complications related to stenting. In one patient, technical problems caused stent dislodgement into the stomach. Another stent patient died of hemorrhage from an untreated tumor in the stomach, but it was considered unlikely that the bleeding was caused by the stent. In conclusion, this preliminary trial suggests that a Wallstent endoprosthesis, used in combination with laser treatment, may become a valuable tool for prolonging the dysphagia-free interval in selected patients.
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| 6. |
- Demiryurek, H., et al.
(author)
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Symptomatic giant cavernous haemangioma of the liver : Is enucleation a safe method? A single institution report
- 1997
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In: HPB Surgery. - : Hindawi Limited. - 0894-8569. ; 10:5, s. 299-304
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Journal article (peer-reviewed)abstract
- Twenty-three patients with symptomatic giant hemangioma of the liver were treated by surgery between 1979 and 1996 at the department of General Surgery, Faculty of Medicine, University of Çukurova. Twenty-three enucleations were performed in 21 patients, left lateral segmentectomy in one patient and enucleation plus left lobectomy in one patient. The tumors were enucleated along the interface between the hemangioma and normal liver tissue. The diameters of the tumors ranged from 5×5 to 25×15 cm. The mean blood loss for enucleations was 525 ml (range 500–1000 ml). There was no mortality and no postoperative bleeding. Three patients had postoperative complications. Enucleation is the best surgical technique for symptomatic giant hemangioma of the liver. It may be performed with no mortality, low morbidity and the preservation of all normal liver parenchyma.
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| 7. |
- Kalil, A. N., et al.
(author)
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Liver resections for metastases from intraabdominal leiomyosarcoma
- 1999
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In: HPB Surgery. - : Hindawi Limited. - 0894-8569. ; 11:4, s. 261-264
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Journal article (peer-reviewed)abstract
- This paper discusses liver resection for intraabdominal leiomyosarcoma metastases as a therapy for carefully selected patients. Of the 83 hepatectomies performed from 1992 to 1996, five were resections for liver metastases due to intraabdominal leiomyosarcoma, in 3 patients. The surgical indication was single liver metastases, without any evidence of extrahepatic disease. No mortality occurred during surgery and the longest survival was 38 months. We concluded that liver resection for leiomyosarcoma metastases can be performed, allowing a long term survival in an occasional patient.
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| 8. |
- Möller, P. H., et al.
(author)
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Temperature control and light penetration in a feedback interstitial laser thermotherapy system
- 1996
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In: International Journal of Hyperthermia. - : Informa UK Limited. - 0265-6736 .- 1464-5157. ; 12:1, s. 49-63
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Journal article (peer-reviewed)abstract
- The aim of this study was to describe the performance of a closed loop interstitial laser thermotherapy system in processed liver and to demonstrate its suitability for treating a vascularized tumour in vivo. The thermotherapy system consisted of an Nd:YAG laser and a temperature feedback circuit including an automatic thermometry system and thermistor probes. Experiments in processed liver were performed with a sapphire probe and temperature control at a distance of 10 mm. In most experiments at 1-2 W, and in half of the experiments at 3 W, there was no carbonization, a moderate change in the light penetration and excellent control of the temperature. In experiments with output powers of 4-5 W there was carbonization with rapid deterioration of light penetration and impaired control of the temperature. Carbonization affected the distribution of temperatures, which were lower below, and higher above, the laser tip in experiments with carbonization as compared to experiments without carbonization. Treatment of an adenocarcinoma implanted into rat liver was performed at 2 W with a bare fibre and without blood inflow occlusion. The feedback thermistor probe was placed 3 mm outside the margin of the tumour (largest diameter 9.5 ± 0.3 mm (mean ± SEM)). Temperature control and light penetration characteristics were similar to those found in vitro. No tumour could be demonstrated at sacrifice 6 days later. It is concluded that a closed loop feedback system can produce stable and reproducible local hyperthermia, that it performs better when carbonization is avoided and light penetration is preserved and that it has a great potential for interstitial thermotherapy of malignant tumours.
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| 9. |
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| 10. |
- Stenram, Unne, et al.
(author)
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Immunohistochemical expression of metallothionein in resected hepatic primary tumors and colorectal carcinoma metastases
- 1999
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In: APMIS. - : Wiley. - 0903-4641 .- 1600-0463. ; 107:4, s. 420-424
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Journal article (peer-reviewed)abstract
- Metallothionein is a protein with affinity for metals and is present in several tumors. We examined its immunohistochemical expression in 37 resected primary liver tumors and 117 colorectal metastases. The reaction was intense in the two fibrolamellar hepatocellular carcinomas and in many of the hepatocytes of the pseudotumor case of focal nodular hyperplasia. The reaction was low or moderate in 5 of 17 ordinary hepatocellular carcinomas and in 4 of 14 cholangiocellular carcinomas. There was no reaction in one case each of spindle cell hepatocellular carcinoma, oncocytic adenoma and hemangioendothelial sarcoma. In the metastases, the reaction was low or moderate in 14 cases and negative in 103. Surrounding hepatocytes and stromal cells were more or less positive in all cases.
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