Self-Assembling Hemostatic Peptide Gel Used to Successfully Treat Rectal Ulcer in Radiation-Associated Vascular Ectasia: A Case Report

Introduction

Radiation-associated vascular ectasia (RAVE), previously termed chronic radiation proctitis, has an estimated incidence as high as 20% and can result in bleeding, abdominal pain, or bowel dysfunction [1]. Based on those symptoms, its severity is classified according to the Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) morbidity scoring scheme [1,2]. Common endoscopic features, including vascular ectasias, edema, strictures, mucosal bleeding, and rectal ulcers, may be particularly challenging to manage. Argon plasma coagulation (APC) and radiofrequency ablation (RFA) therapy are the mainstay of endoscopic treatment for RAVE. Unfortunately, APC and RFA in fact increase the risk of rectal ulcer formation, which can lead to significant patient disability [2]. A self-assembling hemostatic peptide gel (SAHPG) has been used frequently to achieve hemostasis for gastrointestinal bleeding, but it is hypothesized that it can also promote mucosal repair by creating an extracellular matrix around a site of injury [3]. In this case report, we present a symptomatic rectal ulcer in the setting of RAVE that was successfully healed to resolution using SAHPG.

Case Report

A 41-year-old woman presented for evaluation of lower abdominal pain and rectal bleeding, and a history of invasive cervical adenocarcinoma status post brachytherapy and external beam radiotherapy (EBRT). Nine months after finishing her EBRT, she began experiencing intermittent left-lower quadrant abdominal pain and episodic bright red blood per rectum. She was not taking any antiplatelet or anticoagulation agents and had no known history of coagulopathy. Labs at presentation revealed no abnormality (hemoglobin 14.0 g/dL, platelet count 260 k/µL). A CT scan of the abdomen/pelvis was performed to evaluate her abdominal pain, but it revealed no findings to explain her symptoms and was negative for colonic inflammation. Given her rectal bleeding, she was initially treated conservatively with topical pramoxine without resolution of her symptoms and she thus underwent a colonoscopy.

Her initial colonoscopy revealed bleeding RTOG/EORTC Grade 1 RAVE throughout the rectum, which was treated with APC for hemostasis. Additionally, a single, 6-mm non-bleeding ulcer was found in the distal rectum that was treated with SAHPG only (Figure 1). Two weeks after the procedure, her lower abdominal pain resolved, but she began experiencing rectal bleeding two months later. A flexible sigmoidoscopy again revealed RAVE with mild active bleeding, which was retreated with APC and SAHPG. The rectal ulcer, however, had resolved (Figure 2).

Discussion

RAVE is defined as delayed-onset inflammation of the rectal mucosa, which often occurs 9–14 months after radiation treatment but can occur up to 30 years later [1]. Options for medical therapy in RAVE include chemical cautery with saw dust, formaldehyde, or sucralfate enemas [1]. Additionally, hyperbaric oxygen therapy has been shown to improve mucosal healing in RAVE, but it is expensive, requires specialized equipment/personnel, and takes several weeks of therapy, limiting its availability [1,2].

Endoscopically, the first-line treatment of RAVE includes APC or RFA [1, 2]. However, as with all ablative therapies, there is an increased risk of rectal ulcer development and additional morbidity [2].

SAHPG was developed to obtain hemostasis in the gastrointestinal tract. It effectively achieves hemostasis in a wide variety of gastrointestinal lesions, including RAVE, but its efficacy in promoting mucosal healing has been less well-studied [4–6].

Publications evaluating the healing qualities of this SAHPG demonstrate improved healing in the setting of endoscopic submucosal dissection, vascular ectasias, and even solitary rectal ulcer syndrome [3,7–9]. While the mechanism by which this SAHPG promotes mucosal repair has not been identified, it is hypothesized that the peptide assembly resembles the extracellular matrix, which generates a local environment conducive to tissue repair [3,7].

Other cases of rectal ulcers treated with a SAHPG only addressed hemostasis in the setting of more severe features such as hemodynamic instability or symptomatic anemia, not mucosal repair/healing [6,10]. To our knowledge, there is only 1 other case in the literature of a solitary rectal ulcer treated with SAHPG, but no cases of RAVE-induced ulceration treated with SAHPG exist [9]. Our patient with the RTOG/EORTC Grade 1 RAVE is a unique case in that her rectal ulcer was solely treated with SAHPG, leading to endoscopic and symptom resolution.

Conclusions

SAHPG is an endoscopic tool that can heal rectal ulcers in the setting of RAVE. Questions remain regarding the efficacy of SAHPG monotherapy as opposed to in combination with traditional endoscopic interventions. Additionally, SAHPG use has generally been studied in cases with more severe features rather than those with milder lesions. Its versality in treating a variety of conditions may represent the potential for more generalized use. Further prospective studies would help clarify the role of this novel therapy in a field with scarce therapeutic options.