Clinical Cases - Peritoneal Cavity & Intestines

A fifty-four year old woman presents to your clinic with complaints of cramping, "colicky" abdominal pain, nausea and vomiting, severe constipation (obstipation), dizziness, and a fever for the past two days. Previous surgical history includes an appendectomy. On physical exam you note that her blood pressure is 75/40, heart rate 130, and her temperature is 102. Her abdomen is distended, and auscultation reveals intermittent high-pitched bowel sounds. On light palpation, peritoneal irritation is demonstrated by the presence of involuntary guarding and rebound tenderness. You order a CBC (complete blood count) which demonstrates a white blood cell count of 14,000. You also order an abdominal X-ray which reveals a small bowel obstruction with dilated small bowel loops (greater than 3 cm in diameter), multiple air-fluid levels within the small bowel and a lack of gas in the distal colon and rectum. The diagnosis of a small bowel obstruction is made, and the patient is sent to surgery for evaluation .

Questions to consider:

1. What is small bowel obstruction?
   

   Mechanical obstruction of the bowel lumen, resulting in hyperactivity proximal to the obstruction and inactivity distal to the obstruction; with collection of gas and fluid proximal to the obstruction.

2. What are some common causes of small bowel obstruction?
   

   Three types of causes may be identified:
   1) Mechanical: Due to tumors, intussusception (telescoping), impacted feces, and bezoars.
   2) Intrinsic: Congenital strictures and inflammatory diseases.
   3) Extrinsic: Due to postoperative adhesions, hernias, and neoplasms.

3. What clinical findings are suggestive of small bowel obstruction?
   

   Crampy, "colicky" abdominal pain, nausea and vomiting, constipation, abdominal distension, the variable bowel sounds and the inflammatory signs of fever with subsequent tachycardia and hypovolemia suggested by the lowered blood pressure.

4. What radiographic findings support the diagnosis of small bowel obstruction?
   

   The appearance of both air-fluid levels and the dilation of the small bowel loops proximal to the obstruction, with a lack of air distal to the obstruction within the colon.

5. What is the accumulated gas visualized on the X-ray film?
   

   Nitrogen is not absorbed by the gastric mucosa and therefore moves through the GI tract during normal motility. The nitrogen is trapped proximal to the site of any luminal obstruction.

6. What is the difference between simple and strangulating bowel obstruction?
   

   A simple bowel obstruction implies that the lumen itself is occluded; a strangulating lesion involves a segment of bowel looped back onto itself with a subsequent compression of the vasculature which supplies that region of bowel.

While on the pediatric surgery service, you are called to the neonatal intensive care unit to evaluate a thirty-six hour old infant. The infant is grunting on expiration, his nostrils are flaring with each respiration, his respiratory rate is 52 (normal = 30), and his oxygen saturation is 88%. Auscultation reveals an absence of breath sounds on the left side of his chest, but you note apparent bowel sounds on the left side of the chest. The patient has no bowel sounds within his abdomen. The resident orders a chest x-ray, which demonstrates bowel within the thorax . The x-ray confirms a diagnosis of a congenital diaphragmatic hernia. The patient has an endotracheal tube inserted and is placed on a ventilator. He ultimately requires additional respiratory support and is placed on an Extracorporeal Membrane Oxygenator (ECMO). The resident speaks with the family regarding the surgical repair which is necessary to repair the diaphragmatic hernia.

Questions and answers:

1. What is a congenital diaphragmatic hernia?
   

   It is a herniation of abdominal contents into the thoracic cavity, a congenital defect which occurs in approximately 1/2200 infants.

2. Where are most diaphragmatic hernias located?
   

   Most defects (95%) occur posterolaterally, usually on the left side.

3. What would the surgical repair consist of?
   

   Reducing the hernia and its contents back into the peritoneal cavity, followed by a suture repair of the diaphragm using mesh or creating a flap.

4. What normal apertures are found in the diaphragm, and what structures pass through each aperture?
   

   There are three main apertures:
   
   1) Caval opening: An aperture in the central tendon which transmits the inferior vena cava, the terminal branches of the right phrenic nerve and a few lymphatic vessels. This aperture is at the level of the T8 vertebra.
   
   2) Esophageal opening: At the level of T10, the esophagus passes through the muscle of the right crus of the diaphragm. Accompanying the esophagus are the anterior and posterior vagal trunks, esophageal branches of the left gastric vessels, and a few lymphatic vessels.
   
   3) Aortic hiatus: This aperture is found at the level of T12 and transmits the thoracic duct and the aorta.
   
   In addition there is a sternocostal foramen which transmits lymphatic vessels and the superior epigastric vessels. There are also two small apertures in each crus of the diaphragm that transmit the greater and lesser splanchnic nerve, respectively.

5. What is the motor nerve of the diaphragm?
   

   Phrenic nerve (C3, 4, 5 - keeps the diaphragm alive).

A twenty-year-old migrant worker was brought to the emergency room complaining of severe back pain. He was feverish and restless. He explained that the pain had started several weeks earlier and had gradually gotten worse until it was unbearable. His blood pressure and respiration were slightly elevated, but within normal range. His temperature was 102 degrees. Physical examination showed all movements of his lumbar spine were limited and produced pain. There was a diffuse palpable abdominal mass lateral to his lumbar spine on the right side and a painful swollen area on his anterior thigh just below the inguinal ligament on the same side. Plain film X-rays showed a wider and less distinct than normal psoas major muscle shadow and a demineralization of the lumbar spine. The spaces between the lumbar vertebrae appeared narrowed, especially at T12-L1 and L1-2. A tentative diagnosis of tuberculosis of the spine (Pott's disease) was made and subsequently verified by further lab tests. The patient was given chemotherapy and antibiotics. After minor surgery, he was placed on bed rest with a balanced diet and made an uneventful recovery.

Questions to consider:

1. What is the etiology of Pott's disease and what is the significance of the patient's age?

   Tuberculosis of the spine frequently occurs in untreated tuberculosis in young individuals, especially those on a poor diet. The tubercle bacilli enter through the respiratory tract, pass from lungs to systemic circulation where they have a predilection for lodging in the bone marrow, especially of the spine. They also attack the intervertebral disks damaging them. The described sequelae follow.

2. What is the relationship of the psoas major muscle to the lumbar spine, inguinal ligament and anterior thigh?

   The psoas major muscle arises from the bodies of the lumbar vertebrae, passes under the inguinal ligament where it joins with the iliacus to insert on the lesser trochanter of the femur as the iliopsoas tendon.

3. Why would the psoas appear abnormal radiologically?

   The tuberculous infection of the vertebrae involves the psoas major muscle, and an abscess formed stretching the psoas fascia. The abscess material would make the border of the muscle less well defined. The muscle is enclosed in a fascia along its length. The infection often produces an abscess that tracks along deep to the fascia and into the thigh where it may produce a painful bulge. This may be called a psoas abscess. The stretching of the fascia and muscle involvement would produce the pain and obscure the psoas shadow.

4. How would tuberculosis of the spine involve the anterior thigh?

   Infection of the vertebral bone marrow leads to loss of bone substance and demineralization.

5. Why would mineral be lost from the spine?

   The bacilli also attack the vertebrae and intervertebral disks causing loss of bone and destruction of the disks.

6. What produced the back pain and pain associated with vertebral movements?

   The pain is related to the involvement of the vertebrae, the infected psoas muscle and the fact that the disks are narrowed, pinching the spinal nerves.

7. What might the minor surgery involve?

   The surgery involves draining the abscess without which resolution occurs only slowly.