The protective role of antiplatelet treatment against ulcer formation due to argon plasma coagulation in patients treated for chronic radiation proctitis

Gas plasma-induced platelet activation corresponds to reactive species profiles and lipid oxidation

Surgical-induced hemostasis is a critical step in the closure of incisions, which is frequently achieved via electrocauterization and subsequent tissue necrotization. The latter is associated with postoperative complications. Recent in vivo work suggested reactive species-producing gas plasma technology as a pro-homeostatic agent acting via platelet activation. However, it remained elusive how platelet activation is linked to lipid and protein oxidation and the reactive species compositions. A direct relation between the reactive species composition and platelet activation was revealed by assessing the production of several reactive species and by using antioxidants. In addition, platelet lipidome and proteome analysis identified significantly regulated key lipids in the platelet activation pathway, such as diacylglycerols and phosphatidylinositol as well as oxylipins like thromboxanes. Lipid oxidation products mainly derived from phosphatidylethanolamine and phosphatidylserine species were observed at modest levels. In addition, oxidative post-translational modifications were identified on key proteins of the hemostasis machinery. This study provides new insights into oxidation-induced platelet activation in general and suggests a potential role of those processes in gas plasma-mediated hemostasis in particular.

The Effect of Hyperbaric Oxygen Therapy on Rectal Ulcers after Argon Plasma Coagulation

Chronic radiation proctitis usually develops 3 months after therapy. Despite the lack of standard guidelines regarding treatment, argon plasma coagulation is often a safe and effective endoscopic therapy. However, rectal ulcers are a common complication after argon plasma coagulation. Nevertheless, most patients are asymptomatic and do not require additional monitoring or treatment. We report a case of an argon plasma coagulation-induced ulcer with relevant symptoms and refractory to medical treatment. The patient was treated with hyperbaric oxygen therapy and had complete resolution of the rectal ulcer. Hyperbaric oxygen therapy has shown efficacy in severe chronic proctitis and radiation-induced rectal ulcers, but no clinical report has ever been published on using hyperbaric oxygen therapy for ulcers after argon plasma coagulation. In this case, hyperbaric oxygen therapy was an effective alternative option and can be considered in patients with refractory argon plasma coagulation-induced rectal ulcers.

Efficacy and complications of argon plasma coagulation for hemorrhagic chronic radiation proctitis

BACKGROUND

Chronic radiation proctitis (CRP) is a complication which occurs in 1%-5% of patients who undergo radiotherapy for pelvic malignancies. Although a wide range of therapeutic modalities are available, there is no literature to date showing any particularly appropriate therapeutic modality for each disease stage. Argon plasma coagulation (APC) is currently recommended as the first-choice treatment for hemorrhagic CRP, however, its indication based on long-term follow-up is still unclear. On the hypothesis that the long-term efficacy and safety of APC are not fully understood, we reviewed APC treatment for patients with hemorrhagic CRP from a single center.

AIM

To assess the long-term efficacy and safety of APC for hemorrhagic CRP.

METHODS

This is a retrospective study of consecutive patients treated with APC for hemorrhagic CRP from January 2013 to October 2017. Demographics, clinical variables, and typical endoscopic features were recorded independently. Success was defined as either cessation of bleeding or only occasional traces of bloody stools with no further treatments for at least 12 mo after the last APC treatment. We performed univariate and multivariate analyses to identify factors associated with success and risk factors for fistulas.

RESULTS

Forty-five patients with a median follow-up period of 24 mo (range: 12-67 mo) were enrolled. Fifteen (33.3%) patients required blood transfusion before APC. Successful treatment with APC was achieved in 31 (68.9%) patients. The mean number of APC sessions was 1.3 (1-3). Multivariate analysis showed that APC failure was independently associated with telangiectasias present on more than 50% of the surface area [odds ratio (OR) = 6.53, 95% confidence interval (CI): 1.09-39.19, P = 0.04] and ulcerated area greater than 1 cm2 (OR = 8.15, 95%CI: 1.63-40.88, P = 0.01). Six (13.3%) patients had severe complications involving rectal fistulation. The only factor significantly associated with severe complications was ulcerated area greater than 1 cm2 (P = 0.035).

CONCLUSION

The long-term efficacy of APC for hemorrhagic CRP is uncertain in patients with telangiectasias present on > 50% of the surface area and ulceration > 1 cm2.

Expression of vascular endothelial growth factor and its correlation with clinical symptoms and endoscopic findings in patients with chronic radiation proctitis

AIM

The aim of this study was to assess the expression of vascular endothelial growth factor (VEGF) as a key proangiogenic factor and determine whether there is any correlation between its expression and clinical symptoms or endoscopic changes in patients with chronic radiation proctitis (ChRP).

METHOD

Fifty patients who had all undergone radiotherapy for prostate, cervical or uterine cancer were included in the study (37 women, 13 men). There was a control group of 20 patients (9 women, 11 men). The Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) scoring system was used for grading the severity of the proctitis. Endoscopic scoring of late rectal mucosal damage was performed using Gilinsky's classification. Serum levels of VEGF were analysed by the enzyme-linked immunosorbent assay method.

RESULTS

Most patients presented with Grade 1 symptoms. Endoscopic assessment showed that most patients had Grade 1 late rectal mucosal damage. The predominant endoscopic finding was the presence of telangiectasia. Assessment of VEGF correlation between the control group and the degrees of endoscopic changes showed statistically significant differences for all three degrees (P < 0.0001, P = 0.0251 and P = 0.0005, respectively). Due to the small numbers of patients with Grades 2 and 3 symptoms using the RTOG/EORTC scoring system, they were grouped with Grades 1 and 4 respectively forming two groups for statistical purposes. VEGF expression differed significantly between controls and group I and between controls and group II (P = 0.0001, P = 0.0009, respectively).

CONCLUSION

A significant increase in VEGF expression was found to correlate with clinical symptoms and endoscopic rectal mucosa changes in patients with ChRP, suggesting that it may play an important role in pathological angiogenesis.

Chronic radiation proctopathy: A practical review of endoscopic treatment

Chronic radiation proctopathy (CRP) is a troublesome complication of pelvic radiotherapy. The most common presentation is rectal bleeding. CRP symptoms interfere with daily activities and decrease quality of life. Rectal bleeding management in patients with CRP represents a conundrum for practitioners. Medical therapy is ineffective in general and surgical approach has a high morbid-mortality. Endoscopy has a role in the diagnosis, staging and treatment of this disease. Currently available endoscopic modalities are formalin, potassium titanyl phosphate laser, neodymium:yttrium-aluminum-garnet laser, argon laser, bipolar electrocoagulation (BiCAP), heater probe, band ligation, cryotherapy, radiofrequency ablation and argon plasma coagulation (APC). Among these options, APC is the most promising.