Pelvic arteriovenous malformation causing per rectal haemorrhage - A case report

We present the case of a 17 years old girl with per rectal haemorrhage secondary to pelvic arteriovenous malformations (AVM) and potentially haemorrhoids. Pelvic AVMs are rare and extremely variable in their clinical presentation, size and location and pose a therapeutic challenge. Focus has turned towards interventional radiological procedures with angioembolisation as the main treatment form for pelvic AVMs.

A 17 years old girl presented to a rural hospital with significant per rectal bleeding requiring transfer to a tertiary centre with interventional radiology capabilities. Diagnostic imaging determined the presence of a pelvic AVM as well as haemorrhoid. She had no prior history of haemorrhoids, per rectal bleeding or per vaginal bleeding. Further diagnostic imaging including a digital subtraction angiography and MRI pelvis was performed and her case was discussed at a multidisciplinary meeting where the decision was made for angioembolisation of a large right rectal AVM as well as precautionary banding of haemorrhoids that had developed secondary to outflow obstruction. A repeat CT mesenteric angiogram a month later demonstrated diminished appearances of the rectal AVM.

Pelvic AVMs are a rare entity and are not a common cause for per rectal bleeding. There is currently no direct consensus on the optimum management of complex pelvic AVMs particularly those that present with a second pathology such as haemorrhoids. Surgical management often results in recurrence or rapid progression of the AVM lesion and recruitment of new blood supply further complicates the problem. Selective embolisation allows for control of haemorrhage and utilises chemical agents as well as detachable coils and balloons. However, postoperative pain and swelling can still be expected and multiple transcatheter embolisations may be required.

The treatment of symptomatic pelvic AVMs is complex and requires a multidisciplinary approach with careful radiological planning prior to embolisation. Angioembolisation is becoming increasingly prevalent and multiple embolisation procedures may be required to reach the desired therapeutic effect.