Investigation of the thermal tissue effects of the argon plasma coagulation modes "pulsed" and "precise" on the porcine esophagus, ex vivo and in vivo

ArgoCap - feasibility and safety of a novel over-the-scope device to facilitate endoscopic APC treatment

INTRODUCTION

Argon plasma coagulation (APC) is an electrosurgical procedure used, among other indications, for treatment of dysplastic Barrett's mucosa. Homogeneous and safe application can be compromised by varying distances and suboptimal angle of the probe to the tissue. In this study, we present ArgoCap, a novel endoscopic device developed to facilitate endoluminal APC treatment. Objectives of this preclinical study were to assess feasibility and safety and to determine suitable APC settings.

MATERIAL AND METHODS

One-hundred and thirty-two APC treatments of predefined areas using various APC settings were performed ex vivo in the opened porcine esophagus. Depth of thermal injury was assessed histologically. Feasibility of APC treatment in different locations was examined in 20 explanted porcine esophagi and in first in vivo porcine applications.

RESULTS

APC treatment in all quadrants of the esophagus was feasible. Histologically, thermal effects involving the whole thickness of the mucosa were visible with all settings. APC with pulsed mode resulted in deep thermal damage with all power settings. No lesions of the muscular layer occurred using precise (E8, E9) and forced (10 W, 20 W) mode.

CONCLUSIONS

Esophageal APC using ArgoCap is feasible and safe. The device has the potential to improve APC treatment of larger mucosal areas.

Trans-Mucosal Efficacy of Non-Thermal Plasma Treatment on Cervical Cancer Tissue and Human Cervix Uteri by a Next Generation Electrosurgical Argon Plasma Device

Non-invasive physical plasma (NIPP) generated by non-thermally operated electrosurgical argon plasma sources is a promising treatment for local chronic inflammatory, precancerous and cancerous diseases. NIPP-enabling plasma sources are highly available and medically approved. The purpose of this study is the investigation of the effects of non-thermal NIPP on cancer cell proliferation, viability and apoptosis and the identification of the underlying biochemical and molecular modes of action. For this, cervical cancer (CC) single cells and healthy human cervical tissue were analyzed by cell counting, caspase activity assays, microscopic and flow-cytometric viability measurements and molecular tissue characterization using Raman imaging. NIPP treatment caused an immediate and persisting decrease in CC cell growth and cell viability associated with significant plasma-dependent effects on lipid structures. These effects could also be identified in primary cells from healthy cervical tissue and could be traced into the basal cell layer of superficially NIPP-treated cervical mucosa. This study shows that NIPP treatment with non-thermally operated electrosurgical argon plasma devices is a promising method for the treatment of human mucosa, inducing specific molecular changes in cells.

Argon and helium plasma coagulation of porcine liver tissue

Objective

Argon plasma coagulation (APC) and helium plasma coagulation (HPC) are electrosurgical techniques that provide noncontact monopolar electrothermal haemostasis. Although these techniques have been widely used clinically during the last three decades, their in vivo effects on liver tissue remain unclear.

Methods

We investigated the effects of different power levels (10–100 W) of APC and HPC on liver coagulation in 11 Landrace pigs. Capillary blood flow and capillary blood flow velocity were recorded with a combined laser Doppler flowmeter and spectrophotometer. The temperature, clinical biochemical parameters, blood gas parameters, bile duct-sealing effect, and coagulation depth were measured.

Results

APC and HPC significantly reduced the capillary blood flow and capillary blood flow velocity compared with baseline flow. No significant temperature change was measured on the liver surface immediately after coagulation. The clinical biochemical and blood gas parameters were not different before and after coagulation. The coagulation depth was positively correlated with the device power setting.

Conclusions

These results prove that APC and HPC provide sufficient superficial haemostasis. No significant systemic effects occurred following coagulation. The depth of the coagulation effect can be controlled through selection of the output power level.

Effects of argon plasma coagulation on human stomach tissue: An ex vivo study

BACKGROUND AND AIM

Argon plasma coagulation (APC) is a safe alternative treatment for gastrointestinal neoplasms and precancerous lesions. However, the extent of thermal damage after APC is difficult to predict. We investigated the effects of APC on human stomach tissue.

METHODS

Argon plasma coagulation was performed on 10 freshly resected human stomachs that were obtained after total gastrectomy. The effects on tissue were compared across power settings (40, 60, and 80 W), durations (5, 10, 15, 20, and 25 s), and between injection (submucosal injection of normal saline) and control (without injection) groups. Success was defined as complete mucosal necrosis without damaging the muscularis propria.

RESULTS

Without submucosal injection, the incidence of damaging the muscularis propria increased as the power and duration increased. Tissue damage in the injection group was mostly confined to the submucosa, even when using the high-power setting. In the injection group, ablations at 40 W for 20 s, 60 W for 15 s, and 80 W for 15 or 20 s produced success rates ≥80%. In the control group, ablations at 60 W for 10 s, and 80 W for 5, or 10 s produced success rates ≥80%. The optimal energy levels to achieve complete mucosal and submucosal necrosis without damaging the muscularis propria were 800-1600 and 600-800 J in the injection and control groups, respectively.

CONCLUSION

Application of APC produces good results with a low risk of perforation.

Esophageal squamous papillomas with focal dermal hypoplasia and eosinophilic esophagitis

Focal dermal hypoplasia (FDH) is a rare disorder of the mesodermal and ectodermal tissues. Here we present an eight-year-old female known to have FDH who presents with poor weight gain and dysphagia. She was diagnosed with multiple esophageal papillomas and eosinophilic esophagitis. She was successfully treated with argon plasma coagulation and ingested fluticasone propionate, which has not been described previously in a child.