General Surgery Coding Alert

Understand diaphragm dividing line.

The code numbers may change, but the distinguishing features that guide your diagnosis code selection for abdominal aortic aneurysm (AAA) will stay the same when you switch from ICD-9 to ICD-10 on Oct. 1, 2014.

Learn the ICD-10 Crosswalk

The ICD-9 codes that describe AAA are as follows:

• 441.3 — Abdominal aneurysm, ruptured
  
• 441.4 — Abdominal aneurysm without rupture
  
• 441.5 — Aortic aneurysm of unspecified site, ruptured
  
• 441.9 — Aortic aneurysm of unspecified site without rupture.
  

The preceding ICD-9 codes crosswalk directly to ICD-10 codes, as follows:

• I71.3 — Abdominal aortic aneurysm, ruptured
  
• I71.4 — Abdominal aortic aneurysm, without rupture
  
• I71.8 — Aortic aneurysm of unspecified site, ruptured
  
• I71.9 — Aortic aneurysm of unspecified site, without rupture.
  

Notice: Other 441 and 171 codes describe aneurysms in the thoracic region or dissection in the thoracoabdominal region.

Look for Same Documentation

Your surgeon’s documentation won’t need to change to allow you to choose the proper ICD-10 code. You’ll still need to know the location (thoracic, abdominal, thoracoabdominal) and whether the aneurysm ruptured so that you may choose the appropriate code.

Coder tips: The diaphragm is the dividing line between the thorax and abdomen, so the thoracic aorta leaves the heart, arches, and descends through the chest until it reaches the diaphragm. The aorta becomes the abdominal aorta after it passes the diaphragm and continues down the abdomen.

Also remember to distinguish between aneurysm, dissection (blood enters through a tear in the aorta’s lining into the space between the vessel’s middle and outer layers, causing a separation), and ectasia (enlargement milder than an aneurysm).