A 70-Year-Old Man With Abdominal Distention and Shock

A 70-year-old man presents to the emergency department (ED) with generalized abdominal pain and distention. The distention has increased progressively over the last 4 days, with a substantial increase today. His mental status has progressively deteriorated, and he cannot provide additional information regarding the onset, course, and character of the pain. The patient's family states that he has not had a bowel movement in 2 days and has never experienced similar symptoms. The patient is a known hypertensive and has been on oral medication for his blood pressure for the past 18 years. He does not have any history of diabetes, myocardial infarction, or stroke. There is no past history of any abdominal surgery. There is no history of travel, the patient is a nonsmoker, and he does not consume alcohol.

On physical examination, the patient is an obese (approximately 242.5 lb [110 kg]), elderly male, who is obtunded. He has a patent airway, bilateral rales, and diminished air entry into both lung bases, normal S₁ and S₂ heart sounds, pallor, poor capillary refill, and a weak, rapid radial pulse. His heart rate is 124 beats per minute. The patient is febrile, with a temperature of 102.0°F (38.9°C). His blood pressure is 85/65 mm Hg, respiratory rate is 26 breaths/min, and a partial pressure of carbon dioxide (Pa co₂) is 52% while breathing room air. The patient's abdomen is grossly distended and hyper-resonant, particularly above the umbilicus. Bowel sounds are totally absent; digital rectal examination reveals hard stools in the rectum. The patient is resuscitated in the ED using an intravenous infusion of lactated Ringer solution. Orotracheal intubation is performed and mechanical ventilation maintained. Intravenous antibiotics are started and a surgical consultation ordered, and then the patient is transported to the intensive care unit.

Laboratory results reveal a white blood cell count of 22,500 cells/mm³ (normal range, 4,000-11,000 cells/mm³), with 82% neutrophils (normal range, 40%-75%). The serum hemoglobin is 9.2 g/dL (normal range, 13.5-18 g/dL), and the hematocrit is 27.5% (normal range, 40%-54%). The serum alanine aminotransferase (ALT) is 78 U/L (normal range, 5-40 U/L), serum bilirubin is 2.3 mg/dL (normal range, 0.2-1.2 mg/dL), and serum C-reactive protein is 28 mg/dL (normal value, < 1.2 mg/dL). Serum creatinine is 4.8 mg/dL (normal range, 0.6-1.4 mg/dL), and serum urea is 79 mg/dL (normal range, 17-50 mg/dL). The plain chest radiograph shows a large air-filled bowel loop in the left hemithorax, with displacement of the mediastinum towards the right side (Figure 1). Supine abdominal x-ray reveals distended small and large bowel loops (Figure 2). A CT scan of the abdomen using both oral and intravenous contrast shows eventration of the left hemidiaphragm and a small right inguinal hernia with a gas shadow amongst its contents (Figure 3). It also demonstrates thickening of the bowel wall and omentum in addition to multiple abscesses between the bowel loops and within the pelvis. The appendix cannot be visualized in the right iliac fossa and there is no evidence of mesenteric vascular occlusion.

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Questions answered incorrectly will be highlighted.

What is the most likely diagnosis?

Hint: Review the findings of the CT scan.

1-Small bowel ischemia with peritonitis

2-Diaphragmatic hernia

3-Sigmoid volvulus

4-Complicated inguinal hernia with the appendix inside the hernial sac (Amyand's hernia)

Case discussion

It was evident from this patient's presentation that he was in septic shock. The patient's supine plain chest x-ray excluded pulmonary septic pathology; however, it raised the suspicion of a diaphragmatic hernia in the left hemithorax. This possibility was excluded by the CT scan, which showed an intact left hemidiaphragm. Abdominal x-ray and CT scanning both excluded the presence of sigmoid volvulus. Contrast-enhanced CT scanning further revealed intact bowel circulation in both the arterial and venous phases eliminating the possibility of mesenteric occlusion as the cause of the abdominal signs. The presence or absence of free air in the peritoneal cavity could not be ascertained on the plain film because of the gross bowel distention. This was also the reason abdominal ultrasonography was not utilized, as the excessive distention would have reduced its diagnostic efficacy. Although the CT scan of the abdomen could not visualize the vermiform appendix in the right lower quadrant, it clearly detected a small right inguinal hernia with an air-filled space among the hernia's contents.

This hernia could not be identified on physical examination because of the small size, inability to elicit a cough impulse, the use of mechanical ventilation, and the patient's obesity. Preoperatively, the etiology of the patient's sepsis could not be confirmed, but the working diagnosis was that of a strangulated inguinal hernia resulting in generalized peritonitis and ileus. The diagnosis of a complicated Amyand's hernia associated with the perforation of an inflamed appendix was made only following laparotomy, as is the case in almost all the reported case series.^[1,2] An Amyand's hernia is an inguinal hernia that contains the vermiform appendix within its hernial sac; it is named after English surgeon, Claudius Amyand. Only approximately 0.13% of cases of Amyand's hernia cases are associated with appendicitis, whereas a noninflamed appendix is found in about 1% of all hernia repairs. The differential diagnoses for Amyand's hernia should include strangulated hernia, strangulated omentocele, Richter hernia, testicular tumor with hemorrhage, acute hydrocele, and inguinal adenitis.

Amyand's hernias can be classified into 4 types: type I, with a normal appendix; type II, with an acute appendicitis localized in the hernial sac; type III, with localized peritonitis; and type IV, with generalized peritonitis. The most common presentation of Amyand's hernia with appendicitis is a painful irreducible inguinal or inguinoscrotal swelling. Patients with irreducible or incarcerated Amyand's hernias present with clinical manifestations of bowel obstruction or perforation.^[3] Published articles regarding preoperative diagnosis of Amyand's hernia by ultrasonography or CT scanning are extremely rare and the condition is almost always discovered intraoperatively.^[4,5]

Reported conditions in patients presenting with incarcerated Amyand's hernias include mucocele of the appendix associated with coexisting colon cancer, fecaliths of the appendix with coexisting colonic diverticulitis, adenocarcinoma of the appendix, and inguinal appendicocele with pseudomyxoma peritonei. A high index of suspicion accompanied by CT scans can avoid delays in management by helping the detection of any coexisting conditions and the planning of the most appropriate procedure, thereby improving patient outcomes.^[2,4,5] CT scans, while helpful, must not delay surgical consultation or intervention in critically ill patients with a surgical abdomen. The most important aspect of surgical intervention in Amyand's hernia is to limit any septic spread that can result from perforation of the appendix. Once the septic process involves the peritoneum, it becomes more difficult to manage and is associated with increased mortality.

The surgical management of Amyand's hernia should be decided on a case-by-case basis according to the type of hernia and the patient's condition. Options include reduction of the appendix and mesh hernioplasty for type I, and appendectomy followed by endogenous repair without mesh for type II. The management of types III and IV Amyand's hernias require more complex procedures, such as exploratory laparotomy, orchiectomy, right hemicolectomy, and debridement of any necrotic bowel. Hernioplasty is contraindicated and should be deferred if the patient's condition is poor or life expectancy is limited.^[2,3]

When considering appendectomy, the surgeon must be mindful of the ease of its reduction and the presence or absence of appendicitis, in addition to the type of Amyand's hernia. If significant trauma occurs to the appendix during a difficult reduction, an appendectomy is indicated because traumatic injury to the appendix increases the risk for postoperative appendicitis.^[6] If appendicitis or incipient necrosis of the appendix are present, a transherniotomy appendectomy should be performed.^[7]

The patient in this case underwent exploratory laparotomy using a long midline incision rather than a limited inguinal incision. This choice allowed for satisfactory exploration of the entire abdomen, incision and drainage of all the intraperitoneal and pelvic abscesses, and generous peritoneal lavage. Intraoperatively, the cecum was found firmly adherent to the anterior abdominal peritoneum in the right inguinal region. With gentle traction of the cecum, the appendix was extracted from the inguinal hernial sac through the internal ring; approximately 15 mL of greenish, fecal-smelling pus were extracted as well. The appendix was severely inflamed, gangrenous, and perforated in many locations. Appendectomy was performed and the peritoneal cavity was irrigated with copious amounts of warm normal saline solution. Hernioplasty was not performed as the presence of pus or perforation of the appendix is an absolute contraindication to the placement of a mesh for hernia repair because this greatly increases the chances of postoperative surgical site infection.^[7] A rectal tube was introduced at the conclusion of surgery to facilitate closure of the abdominal incision and was removed shortly after the patient's recovery from anesthesia. The patient's postoperative course was without incident. Bowel movements were present starting on the 2^nd postoperative day and the patient gradually began tolerating oral feeding. Postoperative investigations revealed a consistent improvement of all major systems. The patient was discharged on the 8^th postoperative day in good overall condition.