Spigelian hernia accounts for only about 2% of all hernias. It occurs as a defect formed in the Spigelian aponeurosis and can be congenital or acquired. In 1645, Adriann van der Spieghel, a Flemish anatomist, was the first to describe a defect in the semilunar line (linea Spigeli). In 1764, Josef Klinkosch defined the Spigelian hernia as a defect in the semilunar line. In most cases, the hernial sac contains the omentum, and in some cases may also contain a segment of AZD8055 or colon that may cause intestinal obstruction. Several cases of congenital Spigelian hernia with undescended testis also have been reported. Preoperative diagnosis is very difficult, because the sac is usually located between muscle layers of the abdominal wall, and therefore abdominal computed tomography (CT) or ultrasound is usually the first choice for confirming the diagnosis. As the incarceration rate of Spigelian hernia is very high, prompt surgery should be performed, either by open or laparoscopic repair. We report a male patient presenting with left lower abdominal pain and a palpable mass, which was later diagnosed as incarcerated Spigelian hernia. He underwent conventional surgery without mesh repair. After surgery, he recovered well without complications or recurrence.
A 57-year-old man presented at our hospital with a mass in the left lower abdomen. His body height is 162 cm and body weight is 69 kg (body mass index: 26.29 kg/m²). He had had pain in this area for about 1 month, but without nausea or vomiting. He worked as a gardener and had to lift heavy things before he had symptoms. On physical examination, an ill-defined mass measuring about 3 cm was palpable, accompanied with mild tenderness. It was more prominent while standing up. Abdominal echography was performed and it revealed a hypoechoic cystic lesion protruding through the muscle layer of the abdominal wall (Fig. 1). Abdominal CT was then performed and it showed a herniation of omentum through the fascial defect of the left lower abdominal wall (Fig. 2).
An impression of incarcerated Spigelian hernia was made and surgery was performed. Intraoperatively, a herniated sac with part of the omentum incarcerated inside the muscle layers through a 1 cm × 1 cm fascial defect was noted (Figs. 3 and 4). The defect was closed with interrupted sutures after reduction of the hernia. The patient was uneventfully discharged from the hospital 5 days later.
These hernias are frequently seen between the 4th decade and 7th decade. The male to female ratio is 1:1.18. Certain conditions such as obesity, rapid weight loss, multiple pregnancies, chronic obstructive pulmonary disease, chronic constipation, ascites, traumas, and previous surgery are all predisposing factors, because they not only increase the intra-abdominal pressure, but also cause a greater weakness of the abdominal wall. Patients most often present with swelling in the mid-to-lower abdomen just lateral to the rectus muscle. They may complain of a sharp pain or tenderness at this site. The hernia is usually reducible in the supine position. The reducible mass may be palpable, even if it sits below the external oblique musculature.
The physical findings are usually equivocal, and imaging studies are needed for confirming the diagnosis. Ultrasound can provide detailed images of the abdominal wall defect, the hernia sac and its contents, and the relationship of the contents to the Spigelian fascia, as well as the rectus, external oblique, and internal oblique muscles. CT of the abdomen will also confirm the presence of a Spigelian hernia. CT is reported to have a sensitivity of 100% and a positive predictive value (PPV) of 100%, whereas ultrasonography has a sensitivity of 90% and a PPV of 100%, and clinical assessment alone has a sensitivity of 100% and a PPV of 36%. The hernia sac of Spigelian hernias consists of extraperitoneal fat and peritoneum; it may or may not have splanchnic contents. Spigelian hernias usually contain only the small bowel or omentum, but the large bowel, stomach, gallbladder, Meckel\’s diverticulum, ovary, testis, leiomyoma of the uterus, and even urinary bladder have also been reported to be contained in the hernia sacs. The incidence of incarceration is about 20%, and therefore once Spigelian hernia is diagnosed, surgery for immediate hernia repair is mandatory. Our case was diagnosed by means of ultrasound and confirmed by a CT scan. A visible fascial defect can be seen in both studies.