Contemporary thoughts on the management of Spigelian hernia.

BACKGROUND

Spigelian hernias are said to be a rare condition of the elderly population, usually arising below the arcuate line. Local experience has led us to challenge these commonly held beliefs.

METHODS

Operations for Spigelian hernia from 2006-2016 were identified from the Edinburgh Lothian Surgical Audit computerised database and case notes were reviewed.

RESULTS

One hundred and one patients underwent surgery for 107 Spigelian hernias in the 10-year period. The female-to-male ratio was 2:1. Ages ranged from 32 to 88 with a median of 64 years. Sixty-five operations were done open and 42 were laparoscopic. Twelve of the 27 for which the precise anatomic location was recorded were situated above the arcuate line. Twenty-nine hernias had small defects and comprised interstitial fat only with no peritoneal sac. Ages in this group ranged from 32 to 80 (median = 48 years). All presented with intermittent local pain and/or swelling, although in three patients the hernias were impalpable. Those three also underwent ultrasound, CT and/or laparoscopy, but the hernias were only identified after open surgical exploration. The remaining 78 cases had peritoneal sacs of varying size with defects up to 9 cm across, and all were identified on imaging and/or laparoscopy. Ages ranged from 38 to 88 (median = 67 years; p < 0.01). Eighteen patients presented as emergencies and all were in this group.

CONCLUSION

Spigelian hernias may be more common than we think and are probably under-diagnosed. They commonly arise above the arcuate line. We describe three clinical stages: Stage 1 hernias are those without peritoneal sacs and tend to arise in younger patients, can be difficult to diagnose and may not seen at laparoscopy. Stages 2 and 3 hernias arise in older patients, do have peritoneal sacs, are visible at laparoscopy and are more likely to present as emergencies. Stage three hernias are too large for laparoscopic repair. The differences between stages likely reflect the natural history of the condition, which begins as extraperitoneal fat protrusion and progresses over many years to develop a peritoneal sac.