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Part VII
Outcomes and Complications
Following Ventral and Incisional
Hernia Repair
381
B.P. Jacob and B. Ramshaw (eds.), The SAGES Manual of Hernia Repair,
DOI 10.1007/978-1-4614-4824-2_32,
© Springer Science+Business Media New York 2013
32. Skin Necrosis After Open
Component Separation: Prevention
and Management
Jignesh V. Unadkat and Dinakar Golla
Component separation as popularized by Ramirez et al. [ 1 ] has been
the mainstay of autologous abdominal wall reconstruction for complex
defects especially with loss of domain. This method allows closure of
signi fi cant midline defects up to 12, 20, and 10 cm in the upper, middle,
and lower abdomen, respectively [ 2 ] . Using this technique, hernia
recurrence rates have been signi fi cantly reduced compared to primary
repair [ 3 ] . One obvious drawback of the procedure is the extensive
dissection of the skin and subcutaneous tissue to access the external
oblique muscle for subsequent release. Signi fi cantly higher wound
complication rates have been reported with skin necrosis occurring in up
to 40 % of the patients [ 4 ] . In the presence of preexisting infection, this
rate is even higher [ 5 ] .
Anatomy
The abdominal wall has a robust blood supply [ 6 ] . Huger divided the
anterior abdominal wall into three zones. Zones I and II, the mid-abdomen
and lower abdomen, respectively, are supplied by the vascular arcade of
the superior and inferior deep epigastric arteries supplemented by
branches from the super fi cial inferior epigastric and super fi cial circum fl ex
iliac arteries to the lower abdominal wall. Zone III is supplied by the
intercostal, subcostal, and lumbar arteries that course toward the midline.
The neurovascular bundle exists between the internal oblique and
transversalis muscles. As such, there is a relatively avascular and nerve-
sparing plane between the external and internal oblique muscles,
382
J.V. Unadkat and D. Golla
providing the anatomic basis for separating the component parts of the
abdominal wall musculature. Blood supply to the skin is provided by
super fi cial and deep vascular systems. In the lower abdomen, direct
super fi cial cutaneous supply comes from super fi cial circum fl ex and
super fi cial inferior epigastric arteries and in the upper abdomen from the
branches off of the subcostal and intercostal arteries. These branches
originate lateral and course toward the midline. In the midline, the
abdomen is supplied predominantly by the indirect blood supply coming
via the musculocutaneous perforators off the deep epigastric arcade.
These perforators are predominantly grouped around the umbilicus.
Pathophysiology
Midline incision to access the hernia sac divides any crossing blood
vessels. As such, the midline skin relies on the blood supply from lateral
sources and deep sources, that is, the periumbilical perforators. In a wide
abdomen, wherein the midline skin is distant from the lateral limits of
the abdomen, direct lateral super fi cial blood supply is limited.
Furthermore, wide undermining of the subcutaneous fl aps to access the
external oblique muscle divides the musculocutaneous perforators,
thereby rendering the abdominal midline skin and subcutaneous areas
avascular. This consequently leads to skin infection and necrosis [ 7 ] and
fat necrosis leading to tissue loss, leaving the midline facial closure
exposed and prone to infections [ 8 ] .
Prevention
Clearly, gentle skin and soft tissue handling is a prerequisite in
preventing most wound complications. One must be cognizant of
potential wound healing complications in patients with several
comorbidities including but not limited to obesity, diabetes, smoking,
and immunosuppressed status. Following component separation, the key
to preventing skin necrosis lies in prevention of severance of blood
supply to the abdominal skin:
1. Careful planning of incision and assessment of any previous
abdominal scars will allow preservation of blood supply to the
midline skin. Presence of right subcostal scar would preclude
undermining of the right adipocutaneous fl ap superiorly.
383
32. Skin Necrosis After Open Component Separation
Similarly, transverse scar for renal transplantation would
preclude undermining of lower adipocutaneous fl aps.
2. Preventing widespread undermining of the adipocutaneous
fl aps would prevent disruption of blood supply to the medial
skin edges. A number of methods have been undertaken to
access the external oblique musculature without signi fi cant
undermining of the adipocutaneous fl aps. Maas et al. [ 9 ] used a
separate longitudinal incision 15 cm laterally from the medial
skin edge to access the external oblique aponeurosis. In their
small series of four patients, none had hernia recurrence or skin
necrosis. Lowe et al. [ 10 ] used balloon dissection of a
subcutaneous pocket via two small lateral incisions on either
side of the abdomen to access the external oblique. Following
this, the external oblique muscle was released endoscopically.
In their series of 37 patients, none of the endoscopic group
patients had any infection, ischemia, or dehiscence compared to
the open approach groups of patients.
3. Preserving the periumbilical musculocutaneous perforators
would maintain blood supply to the medial skin edges.
Dumanian et al. [ 8 ] carefully dissected the adipocutaneous fl aps
off the external oblique muscle taking care to preserve the
periumbilical perforators. They performed lateral dissection
from the defect edges to expose the linea semilunaris both
superior and inferior to the umbilicus and connecting the two
areas via a tunnel lateral to the perforators. Using this technique,
in a series of 41 patients, they obtained signi fi cantly lower
incidence of super fi cial skin complications even in the presence
of contamination/enterocutaneous fi stulae. A modi fi cation
described later [ 3 ] involved the use of 6–8-cm transverse
subcostal incisions bilaterally to access the linea semilunaris
rather than any subcutaneous dissections.
4. A simple key to prevent skin necrosis would be to predict its
occurrence. This idealistic approach, albeit with extreme
uncertainty, can be adapted in a patient such as one who is an
overweight individual with diabetes, who has had multiple
previous abdominal surgeries, and presents with gross
contamination. Excising the excess medial tissue, enough to
allow primary closure, much like a vertical panniculectomy, would
remove the potentially threatened skin and subcutaneous tissue that
may have gone onto ischemic necrosis. In addition, infraumbilical
hernias maybe approached via a standard panniculectomy
384
J.V. Unadkat and D. Golla
approach with excision of threatened tissue at closure. Some
authors [ 3 ] have implemented short-term subatmospheric pressure
dressings as an immediate dressing. This has led to decreased soft
tissue loss and consequent infections.
Management
Management of skin necrosis following component separation
presents a potential challenge. Firstly, the patient usually has had multiple
abdominal surgeries, often through the same incision. Repeated attempts
at hernia repair induce signi fi cant scar formation within the potential
dead space created by elevation of adipocutaneous fl aps. This scar is
avascular which potentiates wound complications. In addition, many
patients have had prior infections or infected mesh repairs. Several
patients have numerous comorbidities further impairing the ability for
wound healing.
Once skin and soft tissue necrosis has occurred, complete debridement
of the necrotic tissues is mandated. All attempts to maintain integrity of
the underlying fascial closure should be made. Soft tissue debridement
can be undertaken using chemical, mechanical, or surgical methods.
Chemical methods involve usage of enzymatic agents. Mechanical
debridements involve regular dressing changes using wet-to-dry dressings
or moist dressings as warranted. Above methods help in situations where
in there is limited or super fi cial tissue necrosis. Full-thickness
adipocutaneous necrosis warrants excision of the affected area either by
the bedside or in the of fi ce or in the operative room depending on the
extent of involvement.
Once all necrotic tissue is excised, the next step would be reconstructing
the defect. Depending on the amount of abdominal soft tissue excess, it
may be possible to advance the remaining abdominal wall to approximate
in the midline. Sometimes, depending on the status of the wound and the
condition of the patient, it may be necessary to temporize the wound
before implementing fi nal reconstruction. Application of subatmospheric
pressure dressing, especially in abdominal contaminated fi elds, has been
shown to enable the growth of healthy granulation tissue [ 11 ] .
Subsequently, these areas can be reconstructed by advancing surrounding
healthy tissue as described above or application of a split-thickness skin
graft.
385
32. Skin Necrosis After Open Component Separation
Conclusion
Hernia repair using the component separation method is safe, effective,
and reliable. Using the standard open technique, undermining of the
adipocutaneous tissue to access and release the external oblique musculature
is fraught with increased incidence of skin and subcutaneous tissue necrosis.
Good planning and several modi fi cations to the standard technique have
demonstrated effectiveness in reduction in the rate of wound complications.
References
1. Ramirez OM, Ruas E, Dellon AL. “Components separation” method for closure of
abdominal-wall defects: an anatomic and clinical study. Plast Reconstr Surg.
1990;86(3):519–26.
2. Shestak KC, Edington HJ, Johnson RR. The separation of anatomic components technique
for the reconstruction of massive midline abdominal wall defects: anatomy, surgical
technique, applications, and limitations revisited. Plast Reconstr Surg. 2000;105(2):731–
8. quiz 9.
3. Ko JH, Wang EC, Salvay DM, Paul BC, Dumanian GA. Abdominal wall reconstruction:
lessons learned from 200 “components separation” procedures. Arch Surg.
2009;144(11):1047–55.
4. Nguyen V, Shestak KC. Separation of anatomic components method of abdominal
wall reconstruction—clinical outcome analysis and an update of surgical modi fi cations
using the technique. Clin Plast Surg. 2006;33(2):247–57.
5. Rosen MJ, Jin J, McGee MF, Williams C, Marks J, Ponsky JL. Laparoscopic component
separation in the single-stage treatment of infected abdominal wall prosthetic removal.
Hernia. 2007;11(5):435–40.
6. Huger Jr WE. The anatomic rationale for abdominal lipectomy. Am Surg.
1979;45(9):612–7.
7. Feng LJ, Price DC, Mathes SJ, Hohn D. Dynamic properties of blood fl ow and
leukocyte mobilization in infected fl aps. World J Surg. 1990;14(6):796–803.
8. Sukkar SM, Dumanian GA, Szczerba SM, Tellez MG. Challenging abdominal wall
defects. Am J Surg. 2001;181(2):115–21.
9. Maas SM, van Engeland M, Leeksma NG, Bleichrodt RP. A modi fi cation of the
“components separation” technique for closure of abdominal wall defects in the
presence of an enterostomy. J Am Coll Surg. 1999;189(1):138–40.
10. Lowe JB, Garza JR, Bowman JL, Rohrich RJ, Strodel WE. Endoscopically assisted
“components separation” for closure of abdominal wall defects. Plast Reconstr Surg.
2000;105(2):720–9. quiz 30.
11. Baharestani MM, Gabriel A. Use of negative pressure wound therapy in the
management of infected abdominal wounds containing mesh: an analysis of outcomes.
Int Wound J. 2011;8(2):118–25.
387
B.P. Jacob and B. Ramshaw (eds.), The SAGES Manual of Hernia Repair,
DOI 10.1007/978-1-4614-4824-2_33,
© Springer Science+Business Media New York 2013
33. Recurrent Incisional Hernia Repair
John G. Linn and Dean J. Mikami
Repairing recurrent incisional hernias comprises thousands of
operations performed nationwide each year. Patients suffering from these
abdominal wall defects constitute a true challenge to general, minimally
invasive, and plastic surgeons across the country. Traditional approaches
to repairing these hernias, including open suture and mesh repair, have
been plagued by repeated recurrences in both the short and long term.
Other options, such as abdominal wall myofascial advancement fl aps
and laparoscopic approaches to incisional hernias have been proposed as
superior alternatives with the potential for lower recurrence rates. Dozens
of different mesh prostheses are available for recurrent hernia repairs, yet
none offers a panacea immune to recurrence or other complications.
Knowledge of all these options is required to provide the best possible
care for patients with these dif fi cult problems.
Scope of the Problem
In 1997, Luijendijk published a series of primary midline incisional
hernias repaired using an interrupted mattress suture, vertical Mayo
repair. They demonstrated a recurrence rate of nearly 50% at 5-year
follow-up [ 1 ] . Later, the same group published the results of a multicenter
trial which randomized patients to either mesh or primary suture repair
of incisional hernias. Recurrence rates of 43% with primary suture repair
and 24% with mesh repair were seen at 3-year follow-up [ 2 ] . While this
second paper is often used to demonstrate the superiority of mesh repair
compared to suture repair, the fact remains that despite good surgical
technique using prosthetic, up to 1/4 of patients will suffer from a hernia
recurrence in only 3 years. For those repaired primarily, the risk of
recurrence is even higher, creating a huge group of patients with recurrent
388
J.G. Linn and D.J. Mikami
hernias that seek further surgical treatment. In 1993, Hesselink examined
a series of over 300 patients who underwent primary incisional hernia
repair and concluded that better techniques in hernia surgery were badly
needed [
3 ] . A population-based study of incisional hernia repairs in
Washington state in 2003 demonstrated that despite signi fi cant increase
in the use of mesh over a 12-year period, the cumulative reoperation rate,
used as a surrogate for recurrence, was over 20% [
4 ] .
Etiology and Pathophysiology of Recurrence
While the problem is signi fi cant, the underlying etiology of recurrence
after a previous hernia repair is still poorly understood. Traditional
surgical teaching links hernia recurrence to tension either created or not
relieved during the repair operation. The use of “tension-free mesh repair”
in inguinal hernias has certainly offered an improvement in recurrence
rate from tissue repair alone. However, surgeons tend to believe that most
of their own incisional hernia repairs are done without tension, and most
published series describe a tension-free technique. Still, incisional hernia
repairs recur at an extremely high rate. Therefore, the pathophysiology of
recurrence likely has more to it than simply tension alone.
Patient-related factors, such as obesity, diabetes, tobacco use, and
medications that impair wound healing such as steroids, have often been
cited as risk factors for incisional hernia recurrence [ 5, 6 ] . Many of these
factors, however, are dif fi cult to cure or alter when patients present with
symptomatic hernias. Patients with these comorbid conditions will
continue to present with recurrent incisional hernias, and surgeons should
focus on aspects of repair that can be controlled.
Local wound problems such as wound infection, hematoma, or mesh
infection requiring removal seem to predispose patients to recurrence as
well [ 7 ] . Providing adequate tissue coverage of mesh prostheses,
judicious use of subcutaneous drains that may serve as routes of bacterial
infection, and careful hemostatic technique may minimize the potential
for these complications that have long-term consequences.
Mesh prostheses, which should probably be utilized for almost all
recurrent incisional hernias, have different degrees of tensile strength,
cross-linking, elasticity, durability, and contraction/shrinkage after
implantation. Animal data suggests that using polypropylene mesh
probably alters the elastic properties of the abdominal wall [ 8 ] , which
may help decrease recurrence. Elasticity will likely vary with different
389
33. Recurrent Incisional Hernia Repair
types of mesh, and poor understanding of this factor may predispose
some patients to recurrence.
While surgical factors are important to consider, molecular alterations
in collagen composition may prove to be underlying causes of hernia
recurrence. A decrease in the ratio of type I to type III collagen has been
implicated in the pathogenesis of inguinal hernia recurrence [ 9 ] . While
matrix metalloproteinases (MMPs) have been implicated in the
pathogenesis of both abdominal aortic aneurysm formation and inguinal
hernia recurrence [ 10 ] , their role in incisional hernia recurrence has been
more dif fi cult to elucidate and remains controversial [ 10, 11 ] . Some data
suggests that fi broblast expression of MMPs may vary with the type of
prosthetic material [ 11 ] .
The last factor that surgeons can control is the technical aspects of
mesh placement and fi xation. Awad and colleagues performed an
exhaustive review of technical factors that led to recurrence in published
series of ventral hernia repair with mesh over the last 40 years. Types of
mesh placement described included the following: (1) sandwich, in
which prostheses are placed both anterior and posterior to the fascia; (2)
onlay, in which mesh prostheses are secured to the anterior surface of the
fascia, which is closed primarily; (3) inlay, in which the mesh is used as
a bridge between two sides of fascia; (4) retrorectus or Rives-Stoppa
repair, in which the mesh is placed deep to the rectus muscles between
the anterior and posterior fascia layers, which are both closed primarily;
and (5) intraperitoneal, as performed with a laparoscopic incisional
hernia repair. Recurrence rates were highest among patients undergoing
inlay and onlay mesh placement, which is supported by other reviews
[ 12, 13 ] . Speci fi c etiologies of hernia recurrence that seemed most
common were inadequate mesh fi xation, lateral mesh detachment, and
mesh infection. Based on these fi ndings, they proposed a speci fi c
classi fi cation system for mechanism of recurrence. Technical factors
include mesh infection, mesh lateral distraction secondary to either
inadequate fi xation or inadequate overlap, and “missed” hernia [ 12 ] .
Wassenaar reported a series of recurrences after 505 laparoscopic
hernia repairs with polytetra fl uoroethylene (PTFE). Interestingly, patients
undergoing non-midline hernia repair, such as subcostal incisional
hernia, had a much higher recurrence rate. While the groups were not
equal due to a much smaller number of subcostal hernias, it does suggest
that laparoscopic repair of subcostal incisional hernias is more dif fi cult
than midline hernias and that technical failure may increase recurrence
rates. Most midline incisional hernia recurrences were immediately
adjacent to the edge of the mesh, suggesting either a missed hernia or an
overall weakness of the previously closed fascia [ 14 ] .
390
J.G. Linn and D.J. Mikami
Speci fi c Challenges
Recurrent incisional hernias may present speci fi c challenges during
repair which are usually irrelevant to primary incisional hernia. Several
unanswered questions remain regarding these challenges. For those
hernias previously repaired with mesh, should it be removed at a second
operation? Should colostomies be resited during the repair of recurrent
incisional and parastomal hernias? Should the presence of these factors
dictate which type of prosthetic is selected? Patients with prior colostomy
or ileostomy incisions have additional levels of complexity that may
make further recurrence even more dif fi cult to prevent. Abdominal wall
vascular supply may be interrupted so that standard repair techniques
cannot be applied.
Finally, the repair of recurrent incisional hernias lends itself well to
the old adage that “the fi rst repair has the best chance to be the last
repair.” These patients have already failed an attempt at repair, and the
likelihood of success probably decreases with each subsequent recurrence
[ 3 ] . While surgeons cannot realistically expect to have recurrence-free
complex hernia practices, proper patient selection, timing of surgery, and
choice of surgical approach are paramount in the battle to minimize
recurrence in this challenging patient population.
Open and Laparoscopic Approaches
to Recurrent Incisional Hernias
Modi fi ed Rives-Stoppa Repair
Careful consideration of mesh placement relative to the anterior
rectus sheath fascia should be included in the discussion of open recurrent
incisional hernia repair. As suggested by the review from Awad previously
cited, inlay and onlay open mesh repairs tend toward higher recurrence
rates compared to sublay or underlay techniques.
The most commonly described technique for open mesh underlay is
a modi fi cation of the Rives-Stoppa repair [ 15 ] . For the purposes of this
discussion, this includes techniques described as “preperitoneal,”
“extraperitoneal,” or “retromuscular” as well. Speci fi cally, this technique
involves several steps: (1) complete dissection and reduction of the
hernia sac and its contents into the abdominal cavity, which may include