EP378 - Management of Extraperitoneal Rectal Perforation in 3 Patients Recently on Bevacizumab

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Purpose/Background: Metastatic rectal cancer requires multidisciplinary management. Bevacizumab is added to the standard chemotherapy as either first or second-line therapy. It has been shown to improve survival but does have 1-3% risk of gastrointestinal perforation. As it inhibits the function of VEGF, which is imperative in wound healing, it is recommended to avoid operation in these patients for 6-8 weeks after the last dose of bevacizumab.

Methods/Interventions: This is a retrospective case series of 3 patients with metastatic low rectal cancer on bevacizumab who presented with extraperitoneal rectal perforation that had received their last dose within the 6 weeks prior to presentation.

Results/Outcomes: 53M with metastatic rectal cancer and primary 7 cm from anal verge. Patient was initially treated with FOLFOX but, due to progression, bevacizumab was added, last dose 6 weeks prior to presentation. Patient presented with extraperitoneal rectal tumor perforation and right gluteal abscess along with septic shock. Patient underwent incision, drain placement, and loop sigmoid colostomy creation. Patient had cardiac arrest POD6 due to upper GI bleed but was ultimately stabilized and was discharged on long term antibiotics. Patient then died 1 month later after a second cardiac arrest.

50F with metastatic rectal cancer and primary 4 cm from anal verge. Patient was initially treated with FOLFOX and bevacizumab. Patient received 3 cycles of therapy, last dose 1 week prior. Patient presented in septic shock with extraperitoneal rectal tumor perforation and presacral abscess not drainable from the perineum. Patient managed with IR drain and loop sigmoid colostomy but had persistent abscess requiring laparoscopic drain placement later removed after collection resolved. Chemotherapy restarted 2 months later.
69 M with metastatic rectal cancer and primary abutting anal verge. Patient was initially treated with FOLFOX but, due to progression, bevacizumab was added, last dose 2 weeks prior. Patient presented in septic shock with extraperitoneal tumor perforation and left perineal abscess. Patient underwent loop sigmoid colostomy creation and perineal debridement. Patient required long term antibiotics for continued small volume collection that did resolve after 4 weeks of antibiotics. Patient was found to have a pulmonary embolus during stay requiring anticoagulation. Patient is planning to restart chemotherapy 2 months after discharge.

Conclusion/Discussion: Extraperitoneal rectal tumor perforation in patients with metastatic rectal cancer on bevacizumab is a complex problem. Due to tumor location, reconstruction options are limited in patients on VEGF inhibitors because of poor wound healing and APR is contraindicated. These patients require counseling about primary tumor risk when chemotherapy first approach is taken. Patients who present with extraperitoneal tumor perforation are often critically ill and can present with either ascending mesorectal infection or perineal soft tissue infection. We demonstrate a viable option is proximal stool diversion and drainage via perineal approach, interventional radiology drain placement, or laparoscopic drain placement which can allow for these patients to get back on chemotherapy.