Spigelian herniae: presentation, diagnosis and treatment.

A personal series of 19 patients (8 males), mean age 62.4 years (range 21-83 years) with a spigelian hernia [right-sided in eight patients (42.1%)] is presented. The defect was confirmed in 18 patients undergoing surgery, extending between the internal and external oblique layers in 15 of those 18 patients (83.3%) and passing through the external oblique layer in three of the 18 (16.7%). Four uncommon variants were encountered in these 18 patients. The sac was empty in six (33.3%), contained small bowel in six (33.3%), greater omentum in five (27.8%), caecum in one (5.6%) and sigmoid colon in one (5.6%). Four of 19 patients (21.1%) presented acutely with a tender irreducible mass. Thirteen of 19 patients (68.4%) presented electively. All had a palpable swelling which was reducible in 11 of these 13 (84.6%). Local pain and tenderness was inconstant. A spigelian hernia was an incidental finding in two of the 19 patients (10.5%). In only nine out of 17 patients (52.9%) was the diagnosis suspected pre-operatively, and treatment was frequently delayed. Predisposing factors were present in 15 of the 19 patients (78.9%).