UPDATED TOPICS IN MINIMALLY INVASIVE ABDOMINAL SURGERY

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Updated Topics in Minimally Invasive Abdominal Surgery
It is important to ensure that the patient has received adequate analgesia and has had blood
tests to ensure clotting is normal before surgery. The patient would also require a ‘group
and save’ due to a small risk of bleeding during or after surgery. Antibiotics are often
prescribed as prophylaxis to help reduce the risk of wound infections. The patient may
require an NG tube if vomiting to prevent the risk of aspiration.
In order to make the diagnosis of appendicitis and at the same time avoid unnecessary
appendicectomies a variety of diagnostic modalities were advanced. A review of the
literature suggested that the clinical diagnosis of acute appendicitis based on symptoms,
physical findings, and serological tests is relatively inaccurate. Despite having high
sensitivity (up to 100%), clinical evaluation has relatively low specificity (73%). This means
that surgeons are likely to overestimate the presence of appendicitis in patients who present
acutely. Several reports have found the use and diagnostic accuracy (specificity and
sensitivity) of ultrasound and computed tomography (CT) to be limited in the preoperative
evaluation of patients with suspected appendicitis especially in the emergency setting.
The most common US technique used to examine patients with acute abdominal pain is the
graded-compression procedure. With this technique, interposing fat and bowel can be
displaced or compressed by means of gradual compression to show underlying structures.
Furthermore, if the bowel cannot be compressed, the noncompressibility itself is an
indication of inflammation. Curved (3.5–5.0-MHz) and linear (5.0–12.0-MHz) transducers
are used most commonly, with frequencies depending on the application and the patient's
stature. The reported sensitivity of ultrasonic detection of appendicitis lies between 55 and
98% and the specificity between 78 and 100%.
Computed Tomography (CT) has a higher sensitivity and specificity for the diagnosis of
appendicitis. The CT technique used to examine patients with acute abdominal pain
generally involves scanning of the entire abdomen after intravenous administration of an
iodinated contrast medium. Although abdominal CT can be performed without contrast
medium, the intravenous administration of contrast material facilitates good accuracy with a
positive predictive value of 95% reported for the diagnosis of appendicitis and a high level
of diagnostic confidence, especially in rendering diagnoses in thin patients, in whom fat
interfaces may be almost absent. Although rectal or oral contrast material may be helpful in
differentiating fluid-filled bowel loops from abscesses in some cases, the use of oral contrast
material can markedly increase the time to complete the test in the emergency setting and
may be contraindicated for patients who potentially may require anesthesia and surgery.
The lack of enteral contrast medium does not seem to hamper the accurate reading of CT
images obtained in patients with acute abdominal pain as it does in postoperative patients.
Exposure to ionizing radiation is a disadvantage of CT. This risk however should be
weighed against the direct diagnostic benefit. CT has been shown to reduce the negativefinding
appendectomy rate from 24% to 3%. However, only routine CT in comparison to
selective use of CT would achieve such results. CT seems to be more sensitive (96% vs. 76%)
and accurate (94% vs. 91%) than US in diagnosing acute appendicitis, whereas they are
almost equal when it comes to specificity (89% vs. 91%). CT imaging tailored to evaluate
acute appendicitis has proven to be particularly successful with a sensitivity of 100%,
specificity of 95%, positive predictive value of 97%, negative predictive value of 100%, and
accuracy of 98%.
Based on the clinical diagnosis, surgical exploration for suspected appendicitis is advocated
early to prevent progression or perforation with its associated morbidity and mortality.