Ureterosciatic hernia

Ureterosciatic hernias are a very rare form of pelvic sciatic hernia and occurs when the ureter passes through the greater or lesser sciatic foramen ¹.

Epidemiology

Ureterosciatic hernias most commonly occur in women aged 40 to 60 years ⁴.

Clinical presentation

Symptoms vary based on involved local structures and the etiology of the sciatic hernia. This is most commonly asymptomatic ^ref. However, symptoms that can occur with a ureterosciatic hernia include ^ref:

• focal pain

• flank pain

• urinary symptoms due to urinary obstruction

• paresthesia or sciatica: due to associated neural compression

• unilateral bulge of the buttocks

Pathology

These hernias are thought to occur due to weakening of the piriformis muscle, which is usually acquired secondary to increased intra-abdominal pressure due to pregnancy, constipation and trauma ^ref.

Types

Three types of ureterosciatic herniae are described dependent on how the ureter exits the pelvis in relation to the piriformis muscle and whether the exit route is via the greater or lesser sciatic foramina ¹:

• suprapiriformis ureterosciatic hernia

  • most common

  • exits through the greater sciatic foramen above the piriformis muscle

• infrapiriformis ureterosciatic hernia

  • second most common

  • exits through the greater sciatic foramen below the piriformis muscle

• subspinous / lesser sciatic / spinotuberous ureterosciatic hernia

  • least common

  • exits through lesser sciatic foramen

Radiographic features

The hernia may be observed on a number of different imaging modalities. Intravenous urography and CT urography may both identify an abnormal path taken by the ureter and show the curlicue ureter sign. Additional findings on these studies include the presence of hydronephrosis. MRI may help to define the hernia sac and it's contents, and relationship to the piriformis muscle.

Treatment and prognosis

Management, like most common hernias, includes determining if the hernia is reducible or symptomatic ². Surgical management can include open or laparoscopic reduction, or stent placement if urinary obstruction is present ³. There is insufficient long term data to comment on the prognosis ^ref.