Radiology for the surgeon

Presentation

An 85-year-old woman was admitted to our surgical ward with a 4-day history of left lumbar pain associated with vomiting and constipation. Her past medical history included congestive heart failure and atrial fibrillation. There was no previous history of trauma or surgery. Physical examination revealed a tender left lumbar mass, 10 cm in diameter, which was not reducible (Fig. 1). The abdomen was mildly distended with active bowel sounds. The patient underwent plain radiography and contrast-enhanced computed tomography (CT) of the abdomen (Fig. 2, Fig. 3)

FIG. 1. Photograph of left lumbar mass.

FIG. 2. Plain radiographic image of the abdomen.

FIG. 3. Contrast-enhanced computed tomographic image of the abdomen.

What is your diagnosis?

Diagnosis

Incarcerated Grynfeltt hernia

Plain abdominal radiography showed a feces-loaded proximal descending colon, with no feces or gas seen distal to the mid-descending colon (Fig. 4, arrow). Contrast-enhanced CT of the abdomen demonstrated herniation of a short segment of descending colon and the adjacent pericolic fat through the superior lumbar triangle of Grynfeltt and Lesshaft to the left flank region, which was diagnostic of superior lumbar or Grynfeltt hernia (Fig. 5). The defect was relatively narrow and measured about 3 cm. The segment of descending colon proximal to the hernia was dilated, filled with feces and looked edematous. The herniated segment of descending colon was opacified by oral contrast, but the descending colon distal to it was collapsed and was not opacified (Fig. 6, arrow), raising the suspicion of impending obstruction.

FIG. 4. Plain radiographic image of the abdomen shows the absence of feces or gas distal to the mid-descending colon (arrow).

FIG. 5. Contrast-enhanced computed tomographic image of the abdomen shows herniation of a short segment of descending colon and the adjacent pericolic fat through the superior lumbar triangle of Grynfeltt and Lesshaft to the left flank region (arrow).

FIG. 6. Contrast-enhanced computed tomographic image of the abdomen shows the collapsed segment of distal descending colon, which was not opacified (arrow).

Emergency laparotomy was arranged after initial resuscitation of the patient. However, she developed an acute myocardial infarction just before surgery and succumbed shortly afterwards.

Lumbar hernias are rare posterolateral abdominal-wall hernias, with only about 300 cases reported in the literature.¹ The hernias may protrude through 1 of 2 anatomical weak points in the lumbar region: the superior lumbar triangle of Grynfeltt and Lesshaft (bounded by the 12th rib superiorly, the internal oblique muscle anteriorly and the erector spinae muscle posteriorly) or the inferior lumbar triangle of Petit (bounded by the latissimus dorsi muscle posteriorly, the external oblique muscle anteriorly and the iliac crest inferiorly).¹ The hernias may contain retroperitoneal fat, kidney, colon or even intraperitoneal structures, most commonly the small bowel. Lumbar hernias may be acquired (80%) or congenital. If acquired, they may be primary (55%) or secondary to trauma, surgery or inflammation (25%).² Patients usually present with a protruding bulge in the lumbar region. It may be asymptomatic or associated with a varying degree of pain. In patients with primary lumbar hernias, bowel incarceration and strangulation may occur in 24% and 18% of cases, respectively.¹

Lumbar hernias may be difficult to diagnose clinically especially in obese patients with small hernias. In such a situation, CT will be particularly helpful in diagnosis by delineating the anatomy and contents of the hernia,³ as clearly demonstrated in our case. It can also allow differentiation of a hernia from renal tumour, other soft-tissue tumour, hematoma or abscess.

Treatment of lumbar hernia consists primarily of surgical repair. Many techniques have been described, including primary repair, local tissue flaps and conventional mesh repair.⁴ Bowel resection may be required in cases with strangulation. More recently, some surgeons have reported the successful use of the laparoscopic approach in repairing lumbar hernia.⁵ Patients may benefit from this minimally invasive approach with less morbidity, less pain, shorter hospital stay, better cosmetic result and minimal effect on everyday living.

Submissions to Radiology for the Surgeon, soft-tissue section, should be sent to the section editor: Dr. Lawrence A. Stein, Department of Radiology, Royal Victoria Hospital, 687 Pine Ave. W, Montréal QC H3A 1A1; lawrence.stein@muhc.mcgill.ca

Competing interests: None declared.

Correspondence to: Dr. Simon S.M. Ng, Department of Surgery, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China; fax (852) 26377974; simonng@surgery.cuhk.edu.hk