Expose the Layers of Abdominal Wall Reconstruction

By John F. Bishop, PA-C, CPC, CGSC, CPRC
Abdominal wall reconstruction has become more common in the past 10 years. Such reconstructions may occur for blunt or penetrating abdominal trauma, abdominal compartment syndrome, wound dehiscence, intraperitoneal tumor resection, or complications of previous abdominal surgery (such as hernias and mesh infections).

Anatomy

The abdomen is comprised of several tissue layers, listed here by location from superficial to deep:

• Skin
• Subcutaneous tissues
• Superficial fascia (scarpa fascia)
• Anterior rectus fascia
• Rectus abdominus muscle
• Posterior rectus fascia
• Extraperitoneal adipose
• Peritoneum

The fascias are layers of elastic, fibrous tissue; adipose is fat; the peritoneum is a membrane that forms the lining of the abdominal cavity, which contains the stomach, intestines, liver, etc. Other abdominal wall structures located lateral to the rectus abdominus muscles are the external oblique fascia and muscle, internal oblique fascia and muscle, and transverses muscle and transversalis fascia. Distinguishing among the abdominal layers is important because the surgeon may close more than one layer of muscle or fascia during reconstruction, and each layer of closure sometimes calls for separate coding.

ICD-9-CM Coding

Diagnostic statements dictated by a surgeon for abdominal wall reconstruction may include:

• Acquired deformity of abdominal wall (738.8 Acquired deformity of other specified site)
• Congenital deformity of abdominal wall (756.70 Other congenital musculoskeletal anomalies; anomaly of abdominal wall, unspecified)
• Loss of upper domain (879.3 Open wound of abdominal wall, anterior, complicated) and/or lower domain (879.5 Open wound of abdominal wall, lateral, without mention of complication)
• Complicated open abdomen (879.3, 879.5, or 879.7 Open wound of other and unspecified parts of trunk, complicated)
• Large, complicated, incarcerated ventral hernia (553.20 Other hernia of abdominal cavity without mention of obstruction or gangrene; ventral hernia, unspecified)
• Large, complicated, incarcerated incisional hernia (553.21 Other hernia of abdominal cavity without mention of obstruction or gangrene; ventral hernia, incisional)
• Diastasis recti (728.84 Disorders of muscle, ligament, and fascia; diastasis of muscle)
• Disruption (dehiscence) of abdominal incision (998.31 Other complications of procedures, not elsewhere classified; disruption of internal operation wound)
• Complication of non-healing surgical wound (998.83 Other specified complications of procedures, not elsewhere classified; non-healing surgical wound)

Although these diagnoses are among the most common, they are not exclusive in prompting abdominal wall reconstruction: Other diagnoses may apply.

CPT® Coding

The various procedures now designed to assist with abdominal wall reconstruction may include a component separation utilizing longitudinal release of the rectus abdominus muscles (15734 Muscle, myocutaneous, or fasciocutaneous flap; trunk).
This release is designed to help relieve the tension in closure of the peritoneum. Most frequently, it is done bilaterally.
The National Correct Coding Initiative (NCCI) and Medicare Physician Fee Schedule (MPFS) Relative Value File do not allow the use of modifiers 50 Bilateral procedure with 15734. Instead, a bilateral procedure may be reported using two units of 15734. Some payers may further require you to append modifier 59 Distinct procedural service to the second unit on a second line entry to indicate a separate anatomic location. Check with your payer for details. There are several appropriate procedures:

• Separate release(s) of the external oblique fascia and muscle (15734; bilateral 15734 x 2—note that second unit may require modifier 59).
• Separate release(s) of the internal oblique fascia and muscle (15734; bilateral 15734 x 2—note that second unit may require modifier 59).
• Separate release(s) of the transverses muscle and transversalis fascia muscle (15734; bilateral 15734 x 2—note that second unit may require modifier 59).
• Application of acellular dermal allograft (such as Alloderm®, Tissuemend®).

The insertion of these allograft materials usually acts as an overlay to strengthen the closure of the rectus and/or fascia. This is reported using 15330 Acellular dermal allograft, trunk, arms, legs; first 100 sq cm or less, or 1% of body area of infants and children for the first 100 sq cm and +15331 Acellular dermal allograft, trunk, arms, legs; each additional 100 sq cm, or each additional 1% of body area of infants and children, or part thereof (List separately in addition to code for primary procedure) for each additional 100 sq cm or part.
For example, you would report placement of 351 sq cm of allograft 15330 for the first 100 sq cm, and 15331 x 3 for the additional 251 sq cm.

• Repair of a reducible ventral or incisional hernia (initial 49560 Repair initial incisional or ventral hernia; reducible or recurrent 49565 Repair recurrent incisional or ventral hernia; reducible)
• Implantation of mesh or other prosthesis for open incisional or ventral hernia repair (+49568 Implantation of mesh or other prosthesis for open incisional or ventral hernia repair or mesh for closure of debridement for necrotizing soft tissue infection (List separately in addition to code for the incisional or ventral hernia repair))
• Adjacent tissue transfer or tissue rearrangement for the closure of the deep subcutaneous tissues and superficial fascia (scarpa fascia) (14301 Adjacent tissue transfer or rearrangement, any area; defect 30.1 sq cm to 60.0 sq cm and +14302 Adjacent tissue transfer or rearrangement, any area; each additional 30.0 sq cm, or part thereof (List separately in addition to code for primary procedure))
• Following surgery, the skin and subcutaneous tissues may require a complex closure (13100-13102)

Op Report Coding Example

In this procedure, a general surgeon and plastic surgeon work as co-surgeons to repair an incisional hernia and reconstruct the abdominal wall. Each co-surgeon must dictate his or her own operative (op) note. We will be coding for the plastic surgeon’s portion of the procedure only, as represented in the following op note.

Pre-op dx: 1. Incisional hernia 2. Acquired deformity of anterior abdominal wall

Post-op dx: 1. Incisional hernia 2. Acquired deformity of anterior abdominal wall

Procedure: 1. Repair of incisional hernia. 2. Components separation of anterior abdominal wall. 3. Bilateral rectus muscle advancement flaps for anterior abdominal wall reconstruction. 4. Insertion of BioA tissue matrix for reinforcement of anterior abdominal wall reconstruction. 5. Adjacent tissue transfer closure of anterior abdominal wall (20 cm x 30 cm).

Procedure in Detail: The patient was brought to the OR … The abdominal scar was excised. We then elevated anterior abdominal flaps from costal margin to costal margin and down to the pubis. This allowed us to expose the hernia sac.

The operation was then turned over to [general surgeon] for reduction of the hernia and lysis of adhesions and small bowel exploration. After the general surgery team had freed the fascial edges, the plastic surgery team scrubbed back in and began the components release portion of the operation.

Incision was made in the anterior rectus fascial sheath, and we then dissected external oblique muscles bilaterally. We were then able to slide the rectus muscle along with the internal oblique muscles medially … This allowed for tension-free closure of the abdomen along the midline … we plicated and closed the anterior abdominal wall along the midline … [and] implanted a BioA tissue matrix … We used 2 sheets of 15 x 9 and quilted them together … We sutured the BioA in with 2-0 Vicryl along the anterior rectus fascia sheath, along the edges where the incisions then were made for the components separation. This spanned the entire area.

We inserted #19French Blake drains … [and] advanced the skin flaps, trimmed off the excess tissue and the additional scar tissue, and closed in multiple layers … The deep layer was closed with 2-0 Vicryl in simple interrupted fashion. The deep dermis was closed with 3-0 Vicryl in simple inverted interrupted fashion. The skin then was approximated with 4-0 monocryl in a subcuticular fashion. The wound was dressed …

The coding template below represents the aforementioned well-documented, summary op report. Not all op reports are this complex, or use the same number or specific CPT® codes and units. I encourage all coders and surgeons to review the CPT® verbiage and make sure each tissue layer (peritoneum, fascia, muscle, subcutaneous, and skin) is well documented to support appropriate and legal reimbursement.

 
The plastic surgeon acts as co-surgeon for the hernia repair, performing the approach (including excision of the abdominal scar and exposure of the hernia sack). This would be reported using 49560 with modifier 62 Two surgeons appended, and a primary diagnosis of incisional hernia (553.21). A tissue matrix also is placed to strengthen the repair and may be reported separately using add-on code 49568.
Although we are not coding for the general surgeon, the lysis of adhesions is bundled to the repair—unless it is documented as unusually difficult or time-consuming, in which case modifier 22 Increased procedural services may be appended to the primary procedure code. Similarly, exploration of the small bowel is not reported separately in this case.
The rectus muscle advancement should be coded 15734 and, because this was a bilateral procedure, may be reported twice. Remember that some payers may require modifier 59 on the second unit. A diagnosis of muscle separation (728.84 Diastasis of muscle) is primary to the hernia diagnosis.
The adjacent tissue transfer used in closing measures a total of 600 sq cm (20 cm x 30 cm). Report 14301 for the first 60 sq cm, and 18 units of 14302 for the remaining 540 sq cm (each unit of 14302 specifies 30 sq cm; 30 sq cm x 18 units = 540 sq cm). Here, the reason for the procedure is the open wound (879.3 Open wound of abdominal wall, anterior, complicated).
Tip: Note the use of modifier 51 on 14301 and 14302: Some payers may not require you to append modifier 51 because the payer’s billing software will recognize multiple procedures and order them accordingly. If you don’t already know your payers’ policy, ask for it in writing.
Although not documented here, if the abdomen is open already, or is a difficult case to close, each separate layer may need individual closure. The coder should read the op note carefully to search for the distinction between each separate layer, and what materials and methods are used for final closure. Even if the surgeon states he used a local tissue advancements flap to close the abdomen, he also may dictate something like, “the deep subcutaneous layers were closed with 0-Vicryl, the superficial sub-Q layer closed with 2-0 Vicryl, the subdermal was closed with 3-0 Vicryl, and the subcuticular layer closed with 4-0 Nylon.” This type of dictation may warrant the use of complex closure codes 13100-13132, as appropriate to the length of the wound.
John F. Bishop, PA-C, CPC, CGSC, CPRC, has 36 years experience as a physician assistant, and is a multi-specialty surgical coder with over 25 years in coding, compliance, auditing, and provider/coder education. He is president of Bishop & Associates, Inc., and senior coder/auditor for The Coding Network, LLC.

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