This study aims to develop and verify a theoretical model to reproduce the thermal response of pancreatic tissue undergone Laser Induced Interstitial Thermotherapy (LITT). The model provides the evaluation of: a) ablated volumes induced by thermal ablation; b) tissue response time to irradiation; and c) heat extinction time. Theoretical volume values were compared with ex vivo healthy tissue and in vivo healthy and neoplastic tissue volume values. The theoretical model takes into account the differences between healthy and neoplastic tissue due to blood perfusion. Mathematical model shows that ablated volume of ex vivo healthy tissue is greater than in vivo one after the same treatment. Moreover, ablated neoplastic in vivo tissue volume is greater than healthy in vivo one, because of tumour angiogenesis. Ablated volume values were compared with experimental data obtained by laser treatment of 30 ex vivo porcine pancreases. Experimental ablated volume values show a good agreement with theoretical values, with an estimated increase of 61% when power increases from 3 W to 6 W, versus 46% of experimental data, and an estimated increase of 14% from 6 W to 10 W, versus 21% of experimental values. LITT could be an alternative or a neo-adjuvant treatment to surgical resection for pancreas cancer removal, and the proposed model could be the basis to supervising the evolution of ablated volumes during tumor treatment.
The influence of some therapy-relevant parameters on Laser Induced Interstitial Thermotherapy (LITT) outcomes on pancreas is assessed. The aim is to execute a sensitivity analysis for an optimal treatment strategy on in vivo pancreas. A numerical model based on Bioheat Equation has been implemented to assess the influence of laser settings (power P and energy E), applicator radius (r(f)) and optical properties (effective attenuation coefficient, μ(eff)) on temperature (T) distribution. Effects on pancreas undergoing LITT have been evaluated with a twofold approach: 1) T rise and maximum T (T(max)) in tissue; 2) injured volumes (vaporized and coagulated ones). We consider parameters range in typical LITT values (P from 1.5 W to 6 W, E from 500 J to 1500 J, r(f) from 150 µm to 600 µm) and optical values reported in literature. Our analysis shows that, among others, P and μ(eff) are the principal influencing factors of thermal effects on pancreas undergoing LITT: P should be carefully chosen by operator to obtain the desired injured volumes, while the accurate measurement of tissue optical properties is crucial to carry out a safe and controlled thermal therapy on pancreas.
Background and study aims Endoscopic retrograde cholangiopancreatography (ERCP) represents the gold standard for jaundice palliation in malignant biliary obstruction (MBO) patients. Biliary drainage using electrocautery lumen apposing metal stent (EC-LAMS) is currently a well-established procedure when ERCP fails. We aimed to assess the technical and clinical success of a new EC-LAMS as the first approach to the palliation of malignant jaundice due to MBO in patients unfit for surgery.
Patients and methods Twenty-five consecutive patients undergoing endoscopic-guided biliary drainage with the new EC-LAMS were prospectively enrolled. Clinical success was defined as bilirubin level decrease > 15 % 24 hours after EC-LAMS placement.
Results Mean age was 76.6 ± 11.56 years, and male patients were 10 (40 %). EC-LAMS placement was technically feasible in 24 patients (96 %) and clinical success rate was 100 %. Only one patient (4 %) experienced a misplacement rescued by an immediate second EC-LAMS placement. The mean duration of hospital stay was 4.66 ± 4.22 days. The median overall survival was 7 months (95 % CI 1–7).
Conclusions In this preliminary study, the new EC-LAMS seems to allow a single-step palliative endoscopic therapy in patients affected by jaundice due to MBO, with high technical and clinical success and low adverse events. Further large prospective studies are warranted to validate these results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.