Páll Helgi Möller

Temperature control and light penetration in a feedback interstitial laser thermotherapy system

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.

Interstitial laser treatment of malignant tumours: initial experience.

This is a prospective pilot investigation of interstitial laser treatment. Twelve patients were treated at 13 sites: seven patients had metastatic or primary liver cancer (with a total of 21 tumour nodules), two had pancreatic carcinoma and four patients had disease at other sites. Treatments were performed with an Nd-YAG laser, using a high power (6 or 10 W), short-time (5 min) technique or a feedback system for temperature regulation at low power (3 W) for 12-16 min. Treatment with high power invariably resulted in rapid carbonization of tissue, which may have contributed to the postoperative death in one patient. The local effect of treatment could be evaluated in 13 hepatic tumours (1.0-10 cm in diameter): 100% necrosis was seen in five and >50% necrosis in the remaining eight. Two tumours were eradicated, five became smaller, and six remained unchanged in size or showed continued growth. Treatment removed or alleviated symptoms in 7/8 symptomatic patients. The feedback system made it possible to avoid carbonization and allowed better control of the tissue temperature. The main problem with either method was to monitor tissue changes in real time, and ultrasonography was found to be of little help in this respect. It is concluded that interstitial laser treatment is a promising method for treatment of tumours. Further development should focus on real-time monitoring and increased volume effect without carbonization.

Feedback interstitial diode laser (805 nm) thermotherapy system: Ex vivo evaluation and mathematical modeling with one and four-fibers

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.

Interstitial deletions including chromosome 3 common eliminated region 1 (C3CER1) prevail in human solid tumors from 10 different tissues

A human chromosomal segment regularly lost during tumor formation of microcell hybrids in SCID mice has been mapped to 3p21.3. This segment, called chromosome 3 common eliminated region 1 (C3CER1, also referred to as CER1), may harbor multiple tumor‐suppressor genes. Because it was found that similar regions were eliminated in an inter‐ and intraspecies system and in two tumor types (mouse fibrosarcoma and human renal cell carcinoma), we hypothesized that the importance of C3CER1 would transgress tissue specificity, that is, it could occur in tumors derived from multiple tissues. To evaluate the loss of C3CER1 in various human tumor types, we conducted loss of heterozygosity (LOH) analysis of 576 human solid tumors from 10 different tissues and compared the frequency of deletion in the C3CER1 area to that in two other regions on 3p: the FHIT/FRA3B region, at 3p14.2, and the VHL region, at 3p25.3. Deletions were detected in the C3CER1 region in 83% of informative tumors. Half (47%) the LOH‐positive tumors showed LOH at all informative markers, indicating a large deletion. The other half (53%) had a discontinuous LOH pattern, suggesting interstitial deletions or breakpoints. The proportion of tumors with C3CER1 deletions was high in all tumor types investigated, ranging from 70% to 94%, except for the soft‐tissue sarcomas (40%). In the VHL and FHIT regions, deletions were observed in 73% and 43%, respectively, of the tumors. Of the three 3p regions analyzed, the highest deletion frequency was observed in the C3CER1 region. Furthermore, we demonstrated that the interstitial deletions including C3CER1 prevail over 3p14.2–pter losses in solid tumors.

Comparison between interstitial laser thermotherapy and excision of an adenocarcinoma transplanted into rat liver.

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 lobe or underwent interstitial laser thermotherapy, which was performed at a steady-state temperature of 46 degrees 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 lobe 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.

Interstitial laser thermotherapy: Comparison between bare fibre and sapphire probe

A sapphire probe and a bare fibre were compared with respect to temperature control and distribution and light fluence in interstitial laser thermotherapy. Experiments were performed in processed liver using an Nd-YAG laser and output power levels of 1–4 W. The temperature was controlled at a distance of 10 mm using a feedback circuit with an automatic thermometry system and thermistor probes. With the sapphire probe, carbonization was rare at power levels of 1–2 W but was observed in half of the experiments at 3 W and in all experiments at 4 W. Using the bare fibre, carbonization was seen in almost all experiments. Absence of carbonization was associated with a moderate decrease in the penetration of light and excellent control of the temperature, whereas carbonization led to rapid impairment of light penetration and temperature control. In addition, the temperature gradient was smaller with the sapphire probe than with the bare fibre or when carbonization was absent. It is concluded that a diffuser tip, such as the sapphire probe, may be preferable to the bare fibre for interstitial laser thermotherapy because it gives a smaller temperature gradient and helps to avoid carbonization which results in preserved light penetration and improved temperature control.

Loperamide-Induced Acute Pancreatitis

Acute pancreatitis is a common disease leading to hospitalizations, most often caused by gallstones or alcohol. We present a case of a patient diagnosed with acute pancreatitis considered to be due to loperamide treatment for diarrhea.

Evrópufaraldur lifrarbólgu A á Íslandi árið 2017. Algengar breytingar í gallblöðru á myndgreiningu

IAim The incidence of hepatitis A (HAV) in Iceland is low with about one case per year in the last decades. Since 2016, there has been an ongoing outbreak of HAV in men who have sex with men (MSM). The aim of this study was to inves-tigate whether cases diagnosed in Iceland during 2017 had any link to the HAV outbreak in Europe. Methods All cases of HAV in Iceland during 2017 were reviewed retrospectively. Results Four of five cases diagnosed during 2017 were MSM and one was a female. Three cases presented the same week in the summer 2017. The age of the patients was between 25 and 39 years. All the male patients had had sex with men from Europe and/or had travelled to Europe prior to admission. All cases had typical signs and symptoms of HAV infection and in all cases recent infection was confirmed by positive serology and exclusion of other causes of acute hepatitis. Four of five patients had radiological signs of changes in the gallbladder with thickening of the wall and oedema and one underwent later an elective cholecystectomy. Conclusion The outbreak of HAV in MSM Europe reached Iceland in the summer 2017, emphasizing the importance of vaccination in this risk group as recommended by the Icelandic Health Authorities. The review of these cases indicate that changes such as thickening of the gallbladder wall without gallstones in patients with HAV are common. It is important to discrimi-nate patients with these changes associated with HAV from patients with acute acalculus cholecystitis.

Nýgengi, orsakir og meðferð við bráðu rofi á ristli á Íslandi 1998-2007

Colon perforation is a serious illness with mortality reported from 0-39%. Surgery used to be the gold standard but treatment has changed as studies have indicated comparable results with less invasive treatment. The aim of this study was to evaluate the incidence of acute colon perforations in Iceland, causes and treatment.A retrospective, nationwide, multicenter analysis was performed based on ICD-10 codes from databases of the main hospitals in Iceland. Age, gender, year of perforation, cause, means of diagnosis, treatment and outcome were registered. Patients under 18 years and post mortem diagnosis were excluded.225 patients met criteria, 131 women (58%) and 94 men (42%), median age 70 years (range 30-95). The most common causes were diverticulitis (67%), colonoscopy (12%) and complications during operations (5%). During the first five study years, 27% received conservative treatment while 71% underwent surgery. By the end of the study era this ratio was 45% and 54% respectively. The rate of permanent stoma was 10%.Diverticulitis was the most common cause of colon perforation in Iceland during the study period. Many patients still undergo surgery but there has been a dramatic change toward more conservative treatment. The rate of stoma closure is comparable to studies elsewhere. 1University Hospital of Iceland, Dept. General Surgery, 2University of Iceland, Faculty of Medicine, 3Akureyri Teaching Hospital, 4Akranes Hospital and Health Care Center, Iceland. Key words: Colon perforation, diverticulitis, Hartmanns reversal. Correspondence: Elsa B. Valsdottir, elsava@landspitali.is.

Gallsteinasjúkdómar hjá þunguðum konum á Landspítala 1990-2010

INTRODUCTION Gallstone disease in pregnant patients and their management in Iceland has not been studied. Management of these patients changed after the introduction of laparoscopic cholecystectomy. The aim of this study was to investigate the incidence, symptoms, diagnostic methods and management of gallstone disease during pregnancy at the National University Hospital of Iceland during the years 1990-2010. MATERIAL AND METHODS This was a retrospective study and included all pregnant women admitted with gallstone diseases to the National University Hospital of Iceland which is the only tertiary hospital in Iceland. Information regarding age, symptoms and diagnostic methods for all women with gallstone disease along with BMI, ASA scores, pathology results and pregnancy related outcomes for women who underwent cholecystectomy were gathered. RESULTS During the twenty year time period 77 women were admitted with gallstone disease in 139 admissions which makes incidence 0,1% amongst pregnant women. Diagnoses incuded biliary colic (n=59), common bile duct stones (n=10), acute cholecystitis (n=7) and gallstone pancreatitis (n=1). The most common symptom was RUQ pain (n=63). Two preterm births were a direct consequence of gallstone disease. Fifteen women underwent cholecystectomy during pregnancy and 17 during the six week period after birth. Mean BMI was 31,1 and median ASA score was 1. Pathology reports showed chronic inflammation (n=24) and acute inflammation (n=5), one case included gallstones without inflammation Adverse outcomes of surgeries were two cases of gallstones left in the common bile duct. No stillbirths or preterm births resulted from cholecystectomies during pregnancy. CONCLUSION Gallstone disease during pregnancy is rare and readmissions are frequent. Pregnancy related complications are rare. Laparoscopic cholecystectomy is safe during pregnancy. Key words: gallstones, pregnancy, laparoscopic cholecystectomy. Correspondence: Pall Helgi Moller pallm@landspitali.is.