Strangulated Epigastric Hernia Mimicking Abdominal Wall Carbuncle: Report of a Case

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1 Formos J Surg 2009;42: Strangulated Epigastric Hernia Mimicking Abdominal Wall Carbuncle: Report of a Case Hsien Liu 1,2, Chih-Kun Huang 1, Po-Chin Yu 1, Pei-Min Hsieh 1, Chao-Ming Hung 1, Yaw-Sen Chen 1 Epigastric hernias occur secondary to herniation via linea alba fascial defects and are clinically uncommon. They are diagnostically challenging to primary care physicians because of their low incidence. Epigastric hernias should be rapidly diagnosed and treated, because their serious complications include bowel incarceration. We herein report a 61-year-old female patient with a strangulated epigastric hernia on clinical presentation. The hernia mimicked a large abdominal wall carbuncle. Further imaging studies confirmed the diagnosis of incarcerated epigastric hernia. In emergent laparotomy, the defect in the linea alba measured 3 cm in diameter and a strangulated small bowel segment which measured 18 cm in length was found inside the hernia sac. Segmental resection of the necrotic small bowel was performed with end-to-end anastomosis. The fascial defect was closed with interrupted sutures. The patient had an uneventful postoperative recovery. No hernia recurrence was noted after 4 years of follow-up. The detailed clinical history and thorough physical examination allowed us to make a differential diagnosis list for all causes of protruding masses along the linea alba. Accordingly, epigastric hernias should always be considered as an important possibility in patients with appropriate clinical signs. Key words: hernias, epigastric hernia, abdominal wall Epigastric hernias are hernias of the linea alba. They represent an uncommon surgical condition and account for 1.6 to 3.6% of all abdominal hernias. 1 Epigastric hernias result in variable clinical conditions, including cholecystitis, pancreatitis, gastric wall abscess, perforated peptic ulcers, gastric outlet obstructions, and liver strangulation. 2-4 This case report describes a 61- year-old woman with a strangulated epigastric hernia which mimicked a large abdominal wall carbuncle. The unusual clinical presentations, possible etiologies, clinical management and surgical techniques for repairing epigastric hernias will be discussed. Case Report A 61-year-old woman visited our clinic with a 5- to 6 days duration of epigastric discomfort accompanied by a tender, swollen epigastric mass. She had enjoyed good health before. She had a history of 4 normal vaginal deliveries and denied any previous abdominal operations or trauma. The patient had no symptoms of fever or vomiting, but had a history of anorexia, nausea, abdominal distension, and severe dehydration. The clinical symptoms and physical examination findings included epigastric tenderness, skin discoloration, and an From the Division of General Surgery 1, Department of Surgery, E-Da Hospital / I-Shou University, Kaohsiung County, Department of Biological Sciences 2, National Sun Yat-Sen University, Taiwan Received: August 19, 2008 Accepted: April 14, 2009 Address reprint request and correspondence to: Po-Chin Yu, M.D., Department of General Surgery, E-DA Hospital / I-Shou university, 1, Yi-Da Road, Jiau-shu Tsuen, Yan-chau Shiang, Kaohsiung County, Taiwan, Tel: ext 2976, Fax: , ed100459@edah.org.tw

2 220 Strangulated Epigastric Hernia Mimicking Carbuncle epigastric mass suggestive of an abdominal wall abscess. She was therefore referred to the surgical clinic for abscess incision and drainage. Her vital signs included a temperature of 36.1 C, a pulse of 110/min, respirations of 18 breaths/min, and a blood presure of 118/80 mmhg. A 9 cm 8 cm 8 cm palpable mass was located at the abdominal wall midline, 15 cm above the umbilicus (Fig 1). The mass was round, elastic, tender, and irreducible. The mass surface was smooth and warm to touch. Hypoactive bowel sounds were noted without definite peritoneal signs. Otherwise there was no gross evidence of visceral herniation or abdominal wall scarring. Laboratory values included a hemoglobin of 16 g/dl, a white blood cell count of 17,000/mm 3, a blood urea nitrogen of 82.5 mg/dl, and a creatinine of 2.0 mg/dl. Abdominal ultrasonography revealed an epigastric subcutaneous mass with a hypoechoic central lesion (Fig 2). Plain abdominal radiographs revealed distended proximal jejunal loops, which was suggestive of intestinal obstruction. An abdominal computed tomography (CT) scan revealed an upper abdominal wall defect with small bowel ventral herniation (Fig 3), and an incarcerated epigastric hernia was diagnosed. The patient was taken to surgery, and a vertical skin incision was made over the palpable mass. The layers were divided to the linea alba layer, and the hernia sac was dissected from the surrounding tissue. The defect in the linea alba measured 3 cm in diameter (Fig 4), and a strangulated small bowel segment which measured 18 cm in length was found inside the herniated sac. Segmental resection of the necrotic small bowel was performed with a primary end to end anastomosis. The fascial defect was closed with interrupted sutures. The Fig 2. Fig 3. Ultrasonography revealed an epigastric subcutaneous mass with a hypoechoic central lesion. An abdominal CT scan revealed an upper abdominal wall defect with ventral small bowel herniation (white arrow) resulting in bowel obstruction. Fig 1. The midline upper abdominal wall bulging mass with associated discoloration. The mass was initially misdiagnosed as an abdominal wall carbuncle. Fig 4. The hernia sac (containing small bowel segments) protruded from the epigastric linea alba defect.

3 L H, Huang CK, Yu PC, et al 221 patient had an uneventful postoperative recovery and was discharged from the surgical service on the 10 th postoperative day. No hernia recurrence was noted after 4 years of follow-up. Discussion Epigastric hernias typically protrude through the linea alba and occur most commonly above the umbilicus. The hernias are usually small (15 to 25 mm in volume), but voluminous epigastric hernias (5 to 10 cm) can occur. They are more common in men than in women, and the most commonly affected age group ranges from 20 to 50 years. The origin and development of epigastric hernias, congenital or acquired, is unclear, although many theories exist as to etiology. Askar et al. 5 have suggested that epigastric hernias occur secondary to a single midline pattern of tendinous fiber decussation from all the strata of the anterior and posterior rectus sheaths. Insufficient fiber decussation at the linea alba may result in a predisposition to epigastric hernia development. Many studies have attempted to evaluate biopsies of the linea alba for further biomechanical study. The team of Korenkov in Germany undertook a biomechanical and histological investigation using 93 cadavers trying to check Askar's theory about the different levels of decussation in the linea alba. 6 They could not confirm his classification, however. Instead, they proposed a new classification dividing the linea alba into three types according to the thickness of the found fibers: the weak, the intermediate, and the compact types, with only the weak type predisposing to an epigastric hernia. Another study from Germany, by the team of Axer and Prescher, also could not confirm Askar's fiber theory of separate lines of decussation and proposed a new model of fiber architecture consisting of a threedimensional, highly structured meshwork of collagen fibers. 7 In this study, special concern was also given to the fibers of the rectus sheath, which have a rather complicated structure with many different places of origin. Given the complex structure and high importance of the rectus sheath in the functional anatomy of the abdominal wall, it is of concern that there are not many published studies about it in the literature. Lang et al. have suggested the vascular lacunae hypothesis as a cause of epigastric herniation. 1 In this hypothesis, vascular lacunae are formed when small blood vessels (which run between the transversalis fascia and the peritoneum) perforate the linea alba, resulting in a space between the peritoneum and the fascia. A fascial defect is created, and the defect enlarges to an epigastric hernia over a period of intermittent straining. Some clinical observations support this hypothesis. However, the actual etiology of epigastric hernias is still under investigation. Surgical repair methods for epigastric hernias are frequently revoluntionary in nature. The Mayo operation (developed in 1895) used a vertical overlapping technique to repair the hernia, 8 and this technique resulted in the bursting tension of the repair site with a high recurrence rate of 20 to 28%. Now, the concept of tension free repair is widely applied to the field of epigastric hernia repair, and the application of an artificial mesh in epigastric hernia repair has resulted in a lower recurrence rate and fewer complications. 9 Strangulated bowel was identified in our case report, and the fascial defect was directly sutured rather than repaired with artificial mesh because of the concern of bacterial translocation and sequential infection. Other individuals recommend laparoscopy for evaluation and repair of epigastric hernias. 10 Liao et al. suggested that laparoscopic methods provide greater visualization of hernia contents to conduct determinations of viability, and also allow for less patient trauma as compared with open surgical repair. Studies are currently examining laparascopy and open surgery as methods for epigastric hernia repair. In conclusion, the repair of epigastric hernias still represents a challenge to surgeons. Although a common and relatively simple procedure, there is no exact protocol today on how the repair should be done. Epigastric hernias are a diagnostic challenge for primary health care physicians because of their infrequent occurrence, and may frequently be misdiagnosed as neoplasia or carbuncles. A detailed clinical history and a thorough physical examination are required for an appropriate diagnosis. Imaging studies including plain radiographic films, ultrasonography, and a CT scan are useful as diagnostic tests. The risk of bowel incarceration emphasizes the necessity for early diagnosis and treatment. Any protruding mass from the linea alba should be carefully examined, and epigastric herniation must be included in the differential diagnosis list. References 1. Lang B, Lau H, Lee F: Epigastric hernia and its etiology. Hernia. 2002;6: Cheung HY, Siu WT, Yau KK, et al: Incarcerated epigastric hernia, a rare cause of gastric outlet obstruction. J Gastrointest Surg. 2004;8: Lankisch PG, Petersen F, Brinkmann G: An enormous ventral

4 222 Strangulated Epigastric Hernia Mimicking Carbuncle (epigastric) hernia as a cause of acute pancreatitis: Pfeffer's closed duodenal loop model in the animal, first seen in a human. Gastroenterology. 2003;124: Goldman G, Rafael AJ, Hanoch K: Acute acalculous cholecystitis due to an incarcerated epigastric hernia. Postgrad Med J. 1985;61: Askar OM: Aponeurotic hernias. Recent observations upon paraumbilical and epigastric hernias. Surg Clin North Am. 1984;64: Korenkov M, Beckers A, Koebke J, et al: Biomechanical and morphological types of the linea alba and its possible role in the pathogenesis of midline incisional hernia. Eur J Surg. 2001;167: Axer H, von Keyserlingk DG, Prescher A: Collagen fibers in linea alba and rectus sheaths. J Surg Res. 2001;96: Mayo WJ: Further experience with the vertical overlapping operation for the radical cure of umbilical hernia. J Am Med Ass. 1903;41: Muschaweck U: Umbilical and epigastric hernia repair. Surg Clini North Am. 2003;83: Liao K, Ramirez J, Carryl C, et al: A new approach in the management of incarcerated hernia: emergency laparoscopic hernia repair. Surg Endosc. 1997;11:944-5.

5 L H, Huang CK, Yu PC, et al 223 1, ~3.6%