|Home | About | Journals | Submit | Contact Us | Français|
This case illustrates the diagnostic uncertainty seen in lumbar herniation as a rare cause of large bowel obstruction.
Lumbar hernias are a rare form of herniation through the lumbar region. This region is bordered by the 12th rib, iliac crest, erector spinae and the lateral margin of external oblique. Fewer than 300 cases are described in the literature. Bowel incarceration may occur; however, strangulation is rare. Cases have been described with diagnosis by barium enema1 and plain abdominal X-ray.2 Here, we present a case of lumbar hernia incarceration causing large bowel obstruction with computed tomography images.
A 56-year-old woman was admitted with a history of absolute constipation for one week and lower abdominal pain radiating to the left flank. She had a past medical history of hypothyroidism and pernicious anaemia. Previous surgery included a para-umbilical hernia repair, anterior vaginal wall repair and a spinal fusion. The patient was obese with a soft abdomen and generalised mild abdominal tenderness. No flank mass was palpable. Bowel sounds were normal. A provisional diagnosis of constipation with secondary obstruction was made. No significant biochemical or haematological abnormalities were found. A plain abdominal radiograph revealed features of distal large bowel obstruction with no gas seen in the sigmoid.
The patient was admitted and treated with intravenous fluids and a phosphate enema. As her tenderness settled, she was managed conservatively for 48 h and passed a bowel movement following her enema. However, her absolute constipation recurred and a contrast computed tomography (CT) was performed which revealed an incarcerated segment of descending colon in a left sided lumbar hernia with proximal features of obstruction (Fig. 1). A mid-line laparotomy was performed which revealed viable descending colon in an inferior lumbar hernia of the posterior abdominal wall. Peritoneal adhesions were dissected and the defect repaired with a double layer polypropylene mesh.
The patient made an uneventful recovery and was discharged home after 10 days. No complications were observed after 6-month follow-up.
Acquired hernias (80%) may be caused by trauma (commonly from blunt trauma), surgery, infection, or occur spontaneously (often due to muscle atrophy, obesity and old age). Lumbar hernia may occur anywhere within the lumbar region. Anatomically, this region is divided into the superior triangle and inferior triangle. The superior triangle (of Grynnfelt–Lesshaft) is the commonest site of herniation and is bounded by the 12th rib, erector spinae and the posterior border of the inferior oblique. The inferior triangle (of Petit) is bounded by the iliac crest, the anterior border of latissimus dorsi and the posterior margin of external oblique. Lumbar hernias may contain a variety of intra-abdominal contents: the colon is most frequent but small bowel, omentum, kidney, stomach and other viscera may enter the hernia. Strangulation is rare and occurs in around 10% of cases;3 this is mainly due to the wide dimensions of the lumbar region.
Lumbar hernia commonly present between the ages of 50–70 years. Most patients with a lumbar hernia are asymptomatic; however, symptoms of lower abdominal pain and backache may be seen at presentation. A loin mass may be palpable with bowel sounds varying according to the contents. Obesity may obscure clinical detection. This case, in particular, illustrates the diagnostic uncertainty associated with this condition, both in vague presenting symptoms and clinical findings obscured by patient habitus. The initial treatment with an enema further added to the diagnostic confusion.
In this case, CT provided the vital role in prompting surgical management. CT is now widely accepted as the imaging modality of choice for lumbar hernia, principally for its role in defining hernia contents accurately.4 This is particularly the case for traumatic hernias, when other intra-abdominal injuries may also be visualised. In this case, CT provided a diagnosis and helped guide operative management.
There are a range of options available for repair of lumbar hernias. These range from simple anatomical repair, rotational pedicled grafts, free grafts and synthetic mesh repair. Various laparoscopic approaches for repair have been identified ranging from a transperitoneal to an extraperitoneal approach. These have been reported in case series for incisional lumbar hernia,5 but have not yet been fully evaluated for their efficacy. In this case, a mid-line laparotomy was chosen due to the presence of large bowel obstruction and the need to assess the viability of the hernia contents.
This case clearly illustrates the diagnostic uncertainty seen in lumbar herniation as a rare cause of large bowel obstruction.