Acquired abdominal wall defects can be challenging. These defects may result from trauma, tumor resection, or complications of previous abdominal surgery, such as hernias and mesh infections.
The abdominal wall functions to protect vital intra-abdominal organs, flex and extend the trunk (torso), and assist in supporting the lumbar spine. The abdominal muscles do not contribute to the function of normal breathing, but patients may recruit them in times of respiratory distress or during forced expiration and coughing.
The goals of abdominal reconstruction are 1) restoration of function and integrity of the musculofascial abdominal wall, 2) prevention of visceral eventration, and 3) provision of dynamic muscle support.
It is essential to understand the anatomy of the abdomen wall. So I will refer you to these on-line sources:
Dr Norman's site as he explains the basic Anatomy of the Abdominal Wall (great pictures)
Clinically Oriented Anatomy by Keith L Moore and Arthur F Dalley; 5th Edition, Google eBook (pp 196-230)
If you have access to Medline, then this article: Structural and functional anatomy of the abdominal wall. Clin Plast Surg. 2006; 33(2):169-79, v (ISSN: 0094-1298).
Abdominal Wall Defects
Abdominal wall defects can be partial or complete. Partial defects involve either the skin or fascia. Complete defects involve deficiencies of the entire abdominal wall, including skin and fascia.
Preoperative considerations that influence the decision-making process and availability of certain reconstructive options include the depth of involvement (partial vs complete) as well as location, size, infection/contamination, timing, staging, and co-morbidity (ie nutritional state, diabetes, COPD, etc). Even with meticulous planning, operative technique, and postoperative care, complications of abdominal wall reconstruction are encountered. Abdominal reconstruction after previous surgery has a high rate of enterotomy, which converts a clean case into a clean-contaminated or contaminated case.
Immediate versus staged repair will depend on the clinical situation.
Immediate reconstruction is preferred.
- It is more cost-effective and less time-consuming in the medically stable patient with a clean wound bed and reliable reconstructive options.
- It may need to be aborted if significant abdominal distention or inflammation is present.
Delayed reconstruction is done when the patient is unstable, reconstructive options are limited or risky, the wound is contaminated, or further procedures are planned.
- This is often done in the trauma patient with a loss of domain (for example when the intestines are too swollen to place back into the abdomen and then wound closed). The wounds of such patients are routinely closed with a temporary substance and subsequently reexplored. A skin graft may be applied as a temporary measure until reconstruction can be performed.
- A split-tissue skin graft (STSG) will aid in contracture, decreasing the size of area. STSGs have a higher success rate than a full-thickness skin graft. The down-side is that a STSG will remain fairly fixed.
- If abdominal reconstruction is delayed, surgery should be avoided for 6 months or until the previous abdominal scar has fully matured. This will decrease the number of adhesions and the density of the scar tissue.
Medically unstable patients with chronic fascial defects are managed nonsurgically with abdominal binders and light activity.
The following is adapted from the algorithms found in the 4th reference below (Rohrich, et al).
Partial Skin Defect --
- Primary Closure when 5 cm or less defect
- Skin Graft
- Flap: Random/local or Fasciocutaneous Flaps
- Vacuum-assisted Closure -- Using this procedure, a sterile foam dressing is placed in the wound cavity and an evacuation tube exits the wound parallel to the skin surface. The surface of the wound is covered to create an airtight seal, and subatmospheric pressure is applied to the foam dressing.
- Tissue Expander
Partial Musculofascial Defect --
Small -- defined as less than 10 cm if central; less than 5 cm if lateral in the upper third. Defined as less than 6 cm if central; less than 3 cm if lateral in the middle third. Defined as less than 20 cm if central; less than 10 cm if lateral in the lower third.
- Primary Closure
- Component Separation
- Local Flaps -- for example: ext oblique, int oblique
Large -- defined as more than 10 cm if central; more than 5 cm if lateral in the upper third. Defined as more than 6 cm if central; more than 3 cm if lateral in the middle third. Defined as more than 20 cm if central; more than 10 cm if lateral in the lower third.
- Distant Flaps -- ie Tensor Fascia Lata Flap, gracilis flap
- Tissue Expansion
- Free Tissue Transfer (FTT)
Adequate Skin (less than 15 cm defect) with musculofascial defect --see above recommendations under Partial Defect
Inadequate Skin (more than 15 cm defect) -- Immediate Reconstruction
Local Flaps/Skin Grafts
- Sup Rectus Abd or Ext Oblique [upper third defects]
- Rectus Abd or ext Oblique [middle third defects]
- Inf rectus abd or int oblique [lower third defects]
- ext latissimus dorsi or ext TFL [upper third defects]
- TFL or RF [both middle and lower third defects]
- vastus lateralis or gracilis [lower third defects]
Free Tissue Transfer
Delayed reconstruction with absorbable mesh and a split-tissue skin graft can be a temporizing solution.
The 2007 study (11th reference article) done by T. S.de Vries Reilingh & others was the first randomized controlled trial comparing two different techniques for repair of giant midline hernias. The series is small, but the results suggest that repair of giant abdominal wall defects with the component separation technique compares favorably with prosthetic repair,
because wound infection in patients in whom a prosthetic repair was performed had major consequences, resulting in removal of the prosthesis in 7, whereas wound infection in patients after CST had only minor consequences.
Disturbed wound healing frequently complicates repair of large abdominal wall hernias. Wound complications such as hematoma, seroma, skin necrosis, and infection are reported in 12%–67% of patients after CST and in 12%–27% after prosthetic repair. Wound complications are associated with the extensive dissection needed in both procedures, which are often performed after intra-abdominal catastrophes. The risk is further increased by the long duration of the operative procedure and the need to mobilize the skin in dividing the epigastric perforating arteries. This endangers the blood supply of the skin, because then it solely depends on the intercostal arteries, which may have been damaged during former operations by introduction of drains, or by stoma construction and other procedures needed in patients with intra-abdominal sepsis.
COMPONENTS SEPARATION TECHNIQUE
Operative technique of the “components separation technique.” (photo credit)
1 = rectus abdominis muscle; 2 = external oblique muscle;
3 = internal oblique muscle;
4 = transversus abdominis muscle;
5 = posterior rectal sheath.
A. Dissection of skin and subcutaneous fat.
B. Transaction of aponeurosis of external oblique muscle and separation of internal oblique muscle.
C. Mobilization of posterior rectal sheath and closure in the midline.
The technique as described by Ramirez (8th reference) is performed by separating the rectus muscle from the posterior rectus sheath. The external oblique muscle is separated from the internal oblique muscle. These separations are atraumatic because of the relatively avascular plane of dissection. The compound flap [the rectus muscle with the anterior rectus sheath and attached interanl oblique and transversus abdominis muscles] can be advanced medially once it is separated from the external oblique muscle. The advancement is in the range of 5 cm in the epigatrium, 10 cm at the waistline, and 3 cm in the suprapubic region for direct closure of abdominal wall defects. If the muscular components are separated bilaterally, these distances are doubled. This allows for closure of some very large mid-line defects as the one pictured below.
Giant Abdominal Hernia before and after repair (photo credit, 11th reference article)
1. Abdominal Wall Reconstruction; eMedicine Article, Feb 26, 2003; Bradon Wilhelmi MD, Arian Mowlavi MD, Michael Neumeister MD, Elvin Zook MD
2. Basic Anatomy of the Abdominal Wall -- good explanation with great pictures (Wesley Norman, PhD, DSc)
3. Clinically Oriented Anatomy by Keith L Moore and Arthur F Dalley; 5th Edition, Google eBook (pp 196-230)
4. An Algorithm for Abdominal Wall Reconstruction; Plastic & Reconstructive Surgery. 105(1):202-216, January 2000; Rohrich, Rod J. M.D.; Lowe, James B. M.D.; Hackney, Fred L. M.D., D.D.S.; Bowman, Julie L. M.D.; Hobar, P. C. M.D.
5. Restoration of Abdominal Wall Integrity as a Salvage Procedure in Difficult Recurrent Abdominal Wall Hernias Using a Method of Wide Myofascial Release; Plastic & Reconstructive Surgery. 107(3):707-716, March 2001; Levine, Jamie P. M.D., and; Karp, Nolan S. M.D.
6. Abdominal Wall Reconstruction following Severe Loss of Domain: The R Adams Cowley Shock Trauma Center Algorithm; Plastic & Reconstructive Surgery. 120(3):669-680, September 1, 2007; Rodriguez, Eduardo D. D.D.S., M.D.; Bluebond-Langner, Rachel M.D.; Silverman, Ronald P. M.D.; Bochicchio, Grant M.D.; Yao, Alice B.A.; Manson, Paul N. M.D.; Scalea, Thomas M.D.
7. Vacuum-Assisted Closure for Defects of the Abdominal Wall; Plastic & Reconstructive Surgery. 121(3):832-839, March 2008; DeFranzo, Anthony J. M.D.; Pitzer, Keith M.D.; Molnar, Joseph A. M.D., Ph.D.; Marks, Malcolm W. M.D.; Chang, Michael C. M.D.; Miller, Preston R. M.D.; Letton, Robert W. M.D.; Argenta, Louis C. M.D.
8. "Components separation” method for closure of abdominal wall
defects: An anatomic and clinical study; Plast.Reconstr. Surg. 86: 519, 1990; Ramirez, O. M., Ruas, E., and Dellon, A. L.
9. Sliding myofascial flap of the rectus abdominis muscles for closure of recurrent ventral hernias; Plast. Reconstr. Surg. 98: 464, 1996; DiBello, J. N., Jr., and Moore, J. H.
10. Risks associated with “components separation” for closure of complex abdominal wall defects. Plast Reconstr Surg 2003;111:1276–1283; Lowe JB III, Lowe JB, Baty JD, et al.
11. Repair of Giant Midline Abdominal Wall Hernias: “Components Separation Technique” versus Prosthetic Repair; World J Surg. 2007 April; 31(4): 756–763; T. S.de Vries Reilingh, H. Goor, J. A. Charbon, C. Rosman, E. J. Hesselink, G. J. Wilt, and R. P. Bleichrodt
12. Method of Surgical Treatment of an Extensive Post-Burn Deformity of the Abdominal Wall and the Lumbosacral Region; Annal of Burns and Fire Disasters, Vol XVII, #1, March 2004; Moroz V., Adamskaya N., Sarygin P., Yudenich A.A.