Prosthetic materials for abdominal wall reconstruction and hernia repair have been available to surgeons for repair of the groin and abdominal wall since the mid-twentieth century. Indeed, use of these materials by either an open or laparoscopic technique is the standard method of repairing incisional or groin hernia in most centers in North America and Europe. The first prosthetic materials used for hernia repair were synthetic meshes made of polypropylene or polyester.1,2 They were introduced in an attempt to decrease the high risk of recurrent hernia observed in patients undergoing direct suture repair. Eventually, prospective randomized trials were conducted that demonstrated repair of even small incisional hernias without the use of mesh (primary closure repair) was associated with a significantly higher risk of recurrence (Figure 20-1), and nonmesh repair of all but the smallest abdominal wall defects was abandoned.3,4,5
Prospective randomized trial of 181 patients with primary or initial recurrent midline incisional hernia were randomized to undergo repair with mesh or by primary suture without mesh. The 10-year cumulative rate of recurrence was 63% for suture repair and 32% for mesh repair (P < .001). (Reprinted with permission from: Burger JW, Luijendijk RW, Hop WC, Halm JA, Verdaasdonk EG, Jeekel J. Long-term follow-up of a randomized controlled trial of suture versus mesh repair of incisional hernia. Ann Surg. 2004;240:578-83.)
Initially, mesh repair of abdominal wall defects was accomplished by sewing the edges of the defect to the prosthetic material, which served to “bridge” the defect, much as a cloth patch repairs a defect in a garment (Figure 20-2). Although this was an improvement compared with primary closure, recurrence rates remained high. In the 1980s, surgeons in Europe and then in the United States began to place the mesh in a “sublay” position, allowing a generous underlay of mesh beyond the fascial defect, usually posterior to the rectus abdominus muscle of the abdominal wall (Figure 20-3). This placement utilized the physical forces of the abdominal wall and peritoneal cavity to hold the prosthetic in place, resulting in an effective repair, and dramatically lower rates of recurrence. An additional advantage of this technique, the “Stoppa” repair (named for Rene Stoppa, a French surgeon), was that the mesh was placed in an extraperitoneal position, essentially replacing the transversalis fascia in the pelvis or abdomen.6 In this setting bowel loops were not in contact with the mesh, and the risk of fistula and/or bowel adhesion and subsequent obstruction was minimized. In addition, the “Stoppa” or “Stoppa repair,” or giant prosthetic repair of visceral sac (GPRVS), was popularized in the United States by Wantz7 and could be applied to reconstruction of large groin hernias, particularly when bilateral or recurrent. This was accomplished by placing mesh in the extraperitoneal pelvis posterior to the pubis, anterior to the bladder, and extending into the iliac fossa bilaterally. Again, the extraperitoneal location of the mesh allowed a large sheet to be placed and minimized the potential for complications related to bowel adhesion to the mesh.8
Cross-section of the abdominal wall demonstrating a “bridging repair” with mesh (green) reapproximating the edges of the external oblique aponeurosis. The mesh is sewn to the edges of the hernia defect. This was a standard approach used in the mid-twentieth century but was associated with an unacceptably high rate of eventual failure.
Cross-section of the abdominal wall demonstrating a “sublay “ or “Stoppa” incisional hernia repair with mesh (green) placed in the retrorectus position within the anterior abdominal wall. The mesh lies posterior to the rectus muscle and anterior to the posterior sheath and/or transversalis fascia, and is, thus, extraperitoneal.
The problem of bowel adhesion to synthetic mesh was further addressed with the development of “composite” synthetic meshes. These meshes were designed for placement within the peritoneal cavity with the parietal surface designed to minimize bowel adhesion. This development expanded the complexity of hernias that could be successfully repaired and facilitated hernia repair using minimal access techniques, which are almost exclusively intraperitoneal.
More recently, bioprosthetic implants have been created that are even less likely to cause adhesions or fistulas when placed in the peritoneal cavity. In addition, these materials can often be used to repair hernias or reconstruct the abdominal wall when bowel resections or contaminated procedures preclude the use of a synthetic mesh because the risk of infection is too high. They are expensive and associated with a higher risk of recurrent hernia, but if their use spares the patient a subsequent reconstructive operation, they are worth consideration at the time of oncologic resection.
The oncologic surgeon must have a fundamental understanding of reconstructive materials available for patients with abdominal wall defects. The decision to proceed with repair of these defects or to hold off has important implications for quality of life and cancer treatment, and these competing concerns require a knowledgeable and experienced surgeon or surgical team. Selection of the appropriate mesh or biologic implant for use is important to facilitate post-treatment recovery. A reasonable understanding of the advantages, disadvantages, and appropriate use of synthetic mesh and biologic implants will facilitate optimal care of these often complex surgical patients.
INDICATIONS AND CLINICAL APPLICATIONS
Abdominal wall reconstruction should be undertaken in most patients with structural defects undergoing radical cancer surgery. Clearly, if a patient is at high risk for infection secondary to gross contamination, excessive blood loss, morbid obesity, or some combination of high-risk clinical features, then delaying reconstruction may be more prudent. In most patients undergoing elective surgery; however, reconstruction of the abdominal wall or inguinal defect at the time of resection is preferable. Definitive repair of an incisional or groin hernia will add 1 to 3 hours to the operative procedure, depending on patient factors and prior surgical history. Done well, it can provide the patient with a significantly improved postoperative recovery and quality of life and avoid future operative procedures.
Preoperative Incisional Hernia
The most common clinical scenario faced by the gynecologic cancer surgeon is the patient who requires operation and has a preexisting incisional hernia. Consideration of repair after cancer resection should be made as part of preoperative planning. In most settings, repair can be safely undertaken, although the technique used and the type of prosthetic material placed requires considerable judgment. Although it is tempting to close a midline incision if it is feasible without the use of mesh, in a patient with an incisional hernia, recurrent hernia will almost always ensue.3,4
1. Choice of prosthetic and surgical placement
Synthetic Prosthesis. Patients undergoing incisional hernia repair without large bowel resection, or with a limited small bowel resection, urinary tract procedure, or both can often be repaired with a synthetic prosthesis. Several examples of synthetic meshes for use in an extraperitoneal location are listed in Table 20-1. In addition, Vicryl (Ethicon, Johnson & Johnson, New Brunswick, New Jersey) mesh is listed, a slowly absorbable mesh composed of a polymer of glycolic and lactic acids, which can be used intraperitoneally as a temporary mesh to reconstruct the peritoneal sac or serve as a temporary repair when the use of a permanent mesh is too hazardous. Permanent synthetic meshes are used when the risk of mesh infection is low. The advantage of synthetic mesh is that it is associated with a significantly lower risk of hernia recurrence than a biologic implant. In addition, the cost of synthetic mesh is very low compared to a biologic implant. Synthetic extraperitoneal mesh is easy to work with and requires relatively few sutures to be placed in order to hold it in place. This is particularly true in pelvic reconstruction, where placement of a large sheet of synthetic mesh in the retropubic, extraperitoneal position with extension into the iliac fossa bilaterally (the Stoppa repair9) requires little fixation because the peritoneal sac holds the mesh in place with the patient in the upright position (Figure 20-4).
Table 20-1.Examples of synthetic mesh available for hernia repair and abdominal wall reconstruction. ||Download (.pdf) Table 20-1. Examples of synthetic mesh available for hernia repair and abdominal wall reconstruction.
|Material ||Trade Name ||Shrinkage ||Strength ||Features |
|Standard polypropylene ||Marlex C.R. (Bard, Inc, Murray Hill, New Jersey) ||Marked ||Strong ||Marked abdominal wall “stiffness” with healing |
|Prolite (Atrium Medical Corporation, Hudson, New Hampshire) ||Mild ||Strong || |
|Lightweight polypropylene ||Prolene Soft Mesh (Ethicon, Johnson & Johnson, New Brunswick, New Jersey) ||Minimal ||Less strength || |
|Polyester fiber ||Mersilene (Ethicon, Johnson & Johnson, New Brunswick, New Jersey) ||Moderate ||Strong || |
Abdominal wall “stiffness”
|Polyglactin ||Vicryl (Ethicon, Johnson & Johnson, New Brunswick, New Jersey) ||Temporary ||Temporary ||Useful as temporizing buttress/support |
Preperitoneal repair of bilateral inguinal hernia using Stoppa technique (giant prosthetic repair of visceral sac). The synthetic mesh is placed between the myopectineal orifice and the peritoneal sac, and envelops the sac, which holds it in place with the patient in the upright position. Extension of the mesh into the retropubic space and into the iliac fossa bilaterally is also a crucial component of repair of a lower abdominal incisional hernia. (Adapted and reproduced with permission from Wantz GE. Atlas of Hernia Surgery. New York, NY: Raven Press, 1991.)
If used in the extraperitoneal position (ie, within the abdominal wall), then a lightweight polypropylene single layer mesh is ideal. These wide-weave meshes are less prone to shrinkage and may cause less sensation of abdominal wall stiffness compared to the traditional heavyweight standard weave polypropylene mesh. In patients with recurrent hernia, obesity, or other risk factors for recurrence, an intermediate weight polypropylene mesh is a reasonable choice and may provide more strength. Polypropylene or polyester mesh is always placed in an extraperitoneal location, so that the peritoneal sac must be closed in order to exclude bowel loops from the mesh and prevent bowel obstruction or fistula. Vicryl mesh (see Table 20-1) is a temporizing, absorbable mesh that can be used to reapproximate the peritoneum to exclude it from a permanent synthetic mesh. This is particularly true when the risk of adhesions is low, namely when the omentum is preserved, and when there has been no extensive adhesiolysis and the bowel has not been previously radiated.
Composite Mesh. When the repair is undertaken with a mesh within the peritoneal cavity, a composite mesh may be used (Table 20-2). The composite mesh is used in an intraperitoneal “underlay” position (Figure 20-5). Any intraperitoneal mesh must be secured to the undersurface of the abdominal wall with sutures placed circumferentially every 1.5 to 2 cm, to prevent interposition of bowel loops between the mesh or implant and the abdominal wall. If a composite synthetic mesh is used, then the parietal surface is composed of material designed to minimize bowel adhesion, while the side facing the abdominal wall promotes adhesion and adherence to secure the mesh and discourage mechanical displacement. There are many composite meshes available for use in hernia repair. Because they are more expensive than noncomposite synthetic mesh and must be secured with more suture fixation, they are almost always restricted to use in an intraperitoneal underlay repair. A few examples among many available products are listed in Table 20-2.
Table 20-2.Selected examples of composite mesh commercially available for hernia repair and abdominal wall reconstruction. ||Download (.pdf) Table 20-2. Selected examples of composite mesh commercially available for hernia repair and abdominal wall reconstruction.
|Mesh ||Adhesive Surface ||Parietal Surface ||Features |
|C-Qur (Atrium Medical Corporation, Hudson, New Hampshire) ||Polypropylene impregnated with omega-3 fatty acids ||Omega-3 fatty acid cross-linked absorbable gel || |
May be cut, easy to use
Fatty acids decrease inflammatory response
|Parietex (Covidien Corporation, Mansfield, Massachusetts) ||Polyester ||Hydrophilic film || |
Cannot be cut
Film comes off with handling
|Proceed (Ethicon, Johnson & Johnson, New Brunswick, New Jersey) ||Lightweight polypropylene ||Oxidized regenerated cellulose || |
Cannot be cut
Cellulose comes off with handling
|Ultrapro (Ethicon, Johnson & Johnson, New Brunswick, New Jersey) ||Lightweight polypropylene ||Poliglicaprone-25 (Monocryl™) || |
Partially absorbable lightweight mesh
Useful for parastomal reinforcement
Cross section of the abdominal wall demonstrating an “underlay” incisional hernia repair with intraperitoneal composite mesh or biologic implant (green) placed within the peritoneal cavity.
Biologic Implant. The third category of prosthetic that may be used for hernia repair and abdominal wall reconstruction is a biologic implant. These can also be used when patients are at very high risk for bowel adhesion to intraperitoneal composite mesh because of extensive adhesiolysis, prior radiation therapy, fistula, or omentectomy. Similar to composite mesh, biologic implants are designed for use within the peritoneal cavity. Biologic implants are composed of xenografts or allografts of acellular collagen and elastin that serve as a scaffold and allow for tissue ingrowth. Biologic implants come in different sizes, thicknesses, and have very different handling characteristics, and several examples are listed in Table 20-3. Because they promote capillary ingrowth and appear to be more resistant to infection, xenografts and allografts can be used in cases where a synthetic mesh may be considered too risky because of the potential for infection. Perhaps the greatest advantage of the prosthetics is that, if they do become infected, they often break down and are less likely to require explant, at least theoretically. Biologic implants take much longer to adhere to the patient’s abdominal wall, so that they rely on the mechanical strength of the suture and the positioning of the mesh to hold the implant in place. In addition, they must be used with great caution in patients who will require postoperative radiation therapy, as their safety in this setting is unknown.
Table 20-3.Biologic implants available for hernia repair and abdominal wall reconstruction. ||Download (.pdf) Table 20-3. Biologic implants available for hernia repair and abdominal wall reconstruction.
|Implant ||Source ||Process ||Thickness ||Cost ||Features |
|AlloDerm (Lifecell Corporation, Bridgewater, New Jersey) ||Cadaveric dermis ||Proprietary ||0.23–3.3 mm ||High ||Easy to use, supple |
|Surgimend (TEI Biosciences, Boston, Massachusetts) ||Acellular porcine dermal collagen ||Non x-linked ||1–4 mm ||Moderate ||Easy to stitch, soft and pliable |
|Permacol (Covidien Corporation, Mansfield, Massachusetts) ||Acellular porcine dermal collagen ||Chemical x-linked ||0.5–1.5 mm ||Moderate ||Stiffer, more difficult to suture, strong |
Another use for biologic implants is to reconstruct the peritoneal sac so that the bowel loops can be excluded from a synthetic mesh repair. A thin piece of allograft or xenograft can be very useful in this setting.
Biologic implants may be used in many similar circumstances as composite synthetic meshes. Although recurrence rates may be higher, risks of infection and adhesion are lower; therefore, careful patient selection is critical to optimal outcomes.
Patients With Groin Hernia Undergoing Cancer Resection
Many patients with primary or recurrent groin hernia should undergo repair at the time of pelvic surgery, although these defects can be more commonly ignored when appropriate and usually do not interfere with closure of the abdominal wall. In a patient at relatively low risk for infection, placement of a large sheet of synthetic single layer mesh in the extraperitoneal retropubic space after reduction of a groin hernia is a safe and effective method of inguinal hernia repair using the preperitoneal approach (see Figure 20-4). Patients who should be strongly considered for repair at the time of cancer surgery include those who are symptomatic preoperatively, and those with femoral hernias, which are associated with a higher risk of incarceration than direct or indirect inguinal hernias. In addition, patients with recurrent groin hernia, or bilateral groin hernia, are ideal candidates for a pelvic preperitoneal repair at the time of cancer resection. This will decrease the potential risk of incarceration postoperatively and preclude the necessity of a subsequent operation.
After radical gynecologic cancer resection, a preperitoneal mesh repair may no longer be technically feasible. The peritoneal sac may not be able to be closed, and thus the bowel loops will lie against the mesh. In this setting, a composite mesh may be placed over the myopectineal orifice with the parietal side facing the peritoneal cavity and the abdominal wall side opposed to the anterior abdominal wall/retropubic space/myopectineal orifice. The mesh is secured to the fascia behind the pubic bone and extends across the defect laterally (see Figure 20-4).
Patients With Extensive Adhesions and Prior Pelvic Radiation or Bowel Resection
Many patients undergoing pelvic cancer surgery will have large bowel resection, or undergo extensive adhesiolysis, and many may have had prior pelvic radiation. In this setting, an intraperitoneal pelvic mesh should be avoided, and a simultaneous anterior repair or subsequent anterior repair of an inguinal hernia(s) may be a safer approach.
Patients Undergoing Permanent Stoma Placement
Strong consideration should be given to mesh placement as a prophylactic measure in patients undergoing creation of a permanent abdominal wall stoma. Parastomal hernia is a debilitating and common complication of stoma creation. Prospective randomized trials have demonstrated that preemptive mesh placement can prevent parastomal hernia and is associated with no higher risk of infection in patients undergoing elective surgery.10,11 Synthetic mesh is used and is placed in the extraperitoneal retrorectus position following stoma creation. Partially absorbable synthetic mesh, such as composite Vicryl/polypropylene (Ultrapro [Ethicon, Johnson & Johnson, New Brunswick, New Jersey]) in the retrorectus sublay, can be used for this purpose (see Table 20-2).
Synthetic Mesh Repair of Abdominal Wall Hernia
Patients are suitable candidates for repair of incisional or groin hernia if they are undergoing elective surgery and there is no gross contamination, and if the procedure has gone well (ie, without excessive blood loss or hemodynamic instability). Essential components of repair include (1) a suitable sublay mesh to accomplish the repair, (2) closure of the peritoneal sac to exclude the bowel from the mesh, and (3) reconstruction of the external oblique with a bridging mesh or primary fascial closure over the sublay repair.
1. Synthetic repair of the mid/upper abdominal incisional hernia
Incisional hernia repair using Stoppa technique. Upper abdominal incisional hernias can be repaired with mesh extending above the coastal margins. Transfascial sutures secure the mesh circumferentially (A, B). Lower incisional hernias extend into the pelvis and the visceral sac holds the lower aspect of the mesh in place with the patient in the upright position; only a retropubic suture secures the lower aspect of the mesh (C). (Adapted with permission from: Wantz GE. Atlas of Hernia Surgery. New York, NY: Raven Press; 1991.)
Stoppa Repair. The ideal location for mesh placement to repair a primary or recurrent incisional hernia is the retrorectus position. This requires dissection of the retromuscular plane bilaterally followed by placement of a sublay prosthetic mesh fixed with transfascial sutures to the abdominal wall (Figure 20-7). The epigastric artery and vein traverse this space and care must be undertaken to ligate branches of the vessels when necessary throughout the dissection. Sometimes dissection of this plane results in bleeding from the main trunk of the vascular pedicle, and ligation can be accomplished without sequelae. This plane is identified by entering the rectus sheath at the midline, then retracting the rectus muscle anteriorly. The posterior rectus sheath above the arcuate line and the transverses abdominus fascia below the arcuate line provide a layer on which the mesh rests excluding the mesh from the peritoneal cavity. A synthetic intermediate weight mesh is placed and secured with transfascial sutures. The mesh should extend to the lateral border of the rectus sheath bilaterally, and at least 6 to 8 cm beyond the hernia defect superiorly and inferiorly. A defect can be cut in the midline at the cephalad and caudad ends of the mesh to allow it to extend above and below the hernia in the midline.
Schematic demonstrating placement of transfascial sutures lateral to the rectus muscle securing the mesh in place (Stoppa repair). (A) Upper abdominal hernia repair: slit in mesh on either side of linea alba. (B) High upper abdominal hernia repair: mesh extends over lower rib cage. (C) Lower abdominal hernia repair: inferior mesh deep into retropubic space. (D) Infraumbilical incisional hernia repair: similar to Stoppa repair (GPRVS). (Adapted with permission from: Wantz GE. Atlas of Hernia Surgery. New York, NY: Raven Press; 1991.)
2. Synthetic repair of lower midline incisional hernia
Most incisional hernias occur in the periumbilical area, and for patients with prior gynecologic procedures these often extend into the lower abdominal midline. Repair of incisional hernias that occur in the lower abdomen and involve the area just above the pubis can be particularly problematic in the reoperative setting. Adhesions from prior surgery make retropubic dissection treacherous and a sufficient underlay of mesh behind the pubis extending into the iliac fossa bilaterally—the ideal approach to these defects—are required so that recurrence at the lower aspect of the repair does not occur (Figures 20-6C and D). These defects can be challenging in patients who have extensive pelvic adhesions or prior pelvic radiation, and use of a preformed “ventral patch” (C-Qur [Atrium Medical Corporation, Hudson, New Hampshire] or Proceed [Ethicon, Johnson & Johnson, New Brunswick, New Jersey] are 2 examples) at the retropubic portion of the incision after optimal dissection and mesh placement can be very helpful.
Bioprosthetic Repair of Incisional Hernia
In select patients, use of a bioprosthetic implant may be preferable to a synthetic mesh. The advantages are that it can be used in less than optimal operative conditions with less risk of infection, and it can be placed in the peritoneal cavity with less concern about adhesion to bowel or other viscera. The disadvantages are that because it integrates slowly, sutures are more important to fix the mesh and prevent bowel loop interposition; therefore, more sutures need be placed. In addition, recurrence rates are higher. Another disadvantage of a bioimplant is that seroma formation around the mesh is very common and can be quite dramatic, necessitating prolonged postoperative surgical drainage. Nonetheless, for the patient in whom a retrorectus dissection is not feasible or a synthetic mesh is not safe, use of a biologic implant for incisional hernia repair can prevent the patient from having to undergo a subsequent hernia repair at another time.
Careful consideration should be given to patients who require postoperative radiation therapy. There are no data regarding the safety of an intraperitoneal bioprosthesis in this setting, and it may be more prudent to defer hernia repair, abdominal wall reconstruction, or both in patients who will require pelvic irradiation. Whether radiation therapy diminishes capillary ingrowth or changes the characteristics of the implant and therefore promotes adhesion of bowel to the graft is unknown.
Synthetic Repair of Groin Hernia, Unilateral or Bilateral
Pelvic cancer surgery often involves exposure of the myopectineal orifice as the peritoneal sac is dissected away from the pelvic organs. This exposure provides an ideal opportunity to undertake a groin hernia repair with mesh in the appropriate setting. The repair requires reduction of the hernia sac from the inguinal canal, a step that must be completed for successful mesh placement between the myopectineal orifice and peritoneal sac. This will prevent migration of the sac back into the inguinal defect. The round ligament is usually divided and the hernia sac is dissected free from the myopectineal orifice. The mesh is then interposed between the peritoneal (visceral) sac and the myopectineal orifice/pubis. The mesh essentially envelops the peritoneal sac, and extends with it into the iliac fossa (see Figure 20-4).
A bilateral hernia is repaired by reducing both sides and then fashioning a mesh to extend across the retropubic space/myopectineal orifice and into the iliac fossa bilaterally. As described by Wantz,14 it measures almost as wide as the iliac crests and envelops the sac, extending anteriorly along the lower midline. Because the peritoneal sac essentially holds the mesh in place, only 1 retropubic suture is generally used for fixation. The mesh envelops the sac along the colic gutters as well (see Figure 20-4). Because the peritoneal sac is closed, excluding the bowel loops from the mesh, a synthetic mesh such as polypropylene or polyester can be used for the repair (see Table 20-1).
Most patients with a parastomal should undergo repair, as these defects enlarge with time and can cause dysfunction of the fecal or urinary conduit. Prior to repair, the hernia contents are reduced from the soft tissue of the abdominal wall, taking care not to devascularize the stoma by disrupting the mesentery supplying the conduit. Once the hernia is reduced, the fascial edges are defined. The defect is then reapproximated with interrupted, 0-Polydiaxanone (PDS) suture. There are several techniques described for repair of parastomal hernia, but these are best undertaken by surgeons with experience and special expertise because recurrence rates are high. Prevention is essential, and patients undergoing permanent stoma creation should be considered for stoma reinforcement with partially absorbable synthetic sublay mesh at the time of stoma creation. Prospective randomized trials have demonstrated that it is a safe and effective method to reduce parastomal hernia occurrence.10,11 Alternatively, intraperitoneal placement of a mesh around the stoma loop can be accomplished, with careful fixation of the mesh to the undersurface of the abdominal wall. A composite mesh or biologic implant may be chosen and used as an underlay in this setting (see Tables 20-2 and 20-3).
Box 20-1 KEY SURGICAL INSTRUMENTATION FOR EXTRAPERI-TONEAL REPAIR
Synthetic, noncomposite mesh, both intermediate (for underlay) and lightweight (bridging) for external oblique closure
Endo Close device for transfascial suture placement
0-Vicryl sutures for transfascial suture and retropubic fixation
Wide and narrow Deaver retractors
Wide and narrow malleable retractors
Most of the preoperative planning in patients undergoing cancer surgery involves planning the primary procedure. The surgeon planning abdominal wall reconstruction, hernia repair, or both will need to wait until the cancer operation has been completed prior to determining precisely how to reconstruct or repair the abdominal wall. Preoperative discussions with the patient and family should involve these uncertainties, and specific approaches or specific discussion about the prosthetic material to be used should be limited as these decisions can only be made once the cancer operation has been accomplished. In addition, if the cancer surgery has been particularly difficult or associated with significant blood loss or bowel contamination, then proceeding with hernia repair or reconstruction with a prosthetic may best be deferred.
Patients who smoke present an extraordinary risk for complications following incisional hernia repair with mesh. They have a very high risk of recurrence following repair,12 and a high risk of wound complications, including infection, dehiscence, necrosis, and chronic mesh infection requiring explant. In patients who will require postoperative adjuvant chemotherapy, it may be more appropriate to forgo repair of an incisional hernia with a prosthetic mesh in a person who smokes, because of the risk that wound complications would prevent the patient from timely treatment with chemotherapy.
The surgeon should ensure that a reasonable variety of mesh is available to accomplish repair. There should be access to synthetic mesh, both polypropylene alone (intermediate and lightweight) and composite mesh suitable for intraperitoneal use. Intermediate and lightweight synthetic mesh shrink less than standard heavyweight polypropylene, and both are suitable for the extraperitoneal underlay repair and/or the bridging mesh sometimes required to reapproximate external oblique over an underlay or sublay repair. In addition, the surgeon should have access to allograft or xenograft for use in case intraoperative events necessitate use of these materials. Hernia repair and abdominal wall reconstruction represent an unpredictable science, and while much preoperative planning can facilitate repair, unexpected circumstances require the availability of a variety of synthetic meshes, composite meshes, and biologic implants in order to perform efficient, safe, and successful abdominal wall reconstruction. Mechanical bowel prep is important prior to hernia repair. This will avoid unnecessary strain on the abdominal wall postoperatively.
Box 20-2 MASTER SURGEON'S PRINCIPLES
Repair incisional hernias using a sublay, ideally a synthetic, extraperitoneal mesh
If a biologic implant is used, then more suture fixation is required and an intraperitoneal underlay is performed
Reconstruct the peritoneal cavity, when possible, with an absorbable mesh (Vicryl) in low-risk patients with omentum, or a bioprosthesis in patients at higher risk for adhesions/fistula
Always reconstruct the external oblique over the sublay or underlay incisional hernia repair, either with primary closure (sometimes facilitated by component separation) or an additional bridging mesh
Stoppa Repair of Midline Hernia
At completion of the cancer resection, the hernia surgeon assesses the abdominal wall. In patients with an intact rectus muscle and posterior rectus sheath/transversalis fascia, the Stoppa repair should be considered the “gold standard” open repair (Figure 20-8). The hernia sac itself can be dissected from the soft tissue of the abdominal wall and used to facilitate closure of the peritoneal sac. If the sac cannot be closed, a small piece of Vicryl mesh may be used to reapproximate the peritoneum. In patients at high risk for adhesions (ie, those with prior enteric fistula, radiated bowel, or multiple adhesions without omentum), a thin piece of allograft may be used instead.
The completed Stoppa repair of a midline hernia.
The surgeon enters the rectus sheath at the midline, identifies the rectus muscle, and dissects the plane posterior to the muscle and anterior to the posterior rectus sheath/transversalis fascia. This plane extends from the midline to the lateral border of the sheath, and for a sufficient distance cephalad and caudad from the fascial defect to allow the mesh to extend well above and below the edges of the hernia. Branches of the epigastric vessels must be clipped or ligated as encountered during this dissection, and the LigaSure device can be very useful, as is a headlight. For a large defect, the rectus sheath can be dissected from the costal margin to the iliac crest and down into the pelvis. Each side of the abdominal wall is dissected, and then a decision is made whether to perform a “component release” to medialize the rectus muscles and external oblique aponeurosis.13 A synthetic mesh is shaped, and circumferential, interrupted 0-Vicryl sutures are placed (see Figure 20-6) to correspond with small circumferential incisions made in the abdominal wall, which approximate the edges of the mesh in situ.
When the defect is very large and the rectus muscle is so displaced that there is little lateral space present for the mesh, a “component release” procedure can be performed to extend the space available for the mesh and “medialize the rectus muscles.” I prefers a “posterior” component release because it does not violate the anterior sheath and create a defect in the anterior fascia (ie, another hernia). This is performed by (1) dissecting all the way to the lateral border of the rectus sheath, (2) retracting the muscle cephalad, (3) entering the space between the internal and external oblique muscles with cautery or by sharp dissection, and (4) opening the length of the lateral border or the rectus sheath from the costal margin to the pelvic brim. This can be performed on one side or on both sides of the abdominal wall, as required.
Once the space for the mesh has been created, then the peritoneal sac is closed with a running suture. If it cannot be closed primarily, a bioprosthesis such as AlloDerm (Lifecell Corporation, Bridgewater, New Jersey; in patients at high risk for adhesion) or Vicryl (when there is omentum over the bowel loops) is used. The surgeon then determines where the transfascial sutures will be placed to secure the mesh. Because the mesh is synthetic, and extraperitoneal, only about 6 transfascial sutures are needed on each side to secure the mesh. The mesh is fashioned, remembering that the retro-rectus space is smaller than the same space as visualized on the anterior abdominal wall, and that the anterior fascia and rectus muscle will be pulled medially prior to completion of the repair. Once the mesh has been cut, the surgeon determines the optimal sites for placement of the transfascial fixation sutures and marks these on the abdominal wall. An eleven blade is used to incise the skin at these sites, creating small stab wounds for passage of the Endo Close device (Figure 20-9). 0-Vicryl sutures are then placed in the mesh at the points for fixation, and the needles removed. The rectus muscle is then retracted anteriorly, and the Endo Close is passed through the anterior stab wounds and used to grab and pull the suture up through the abdominal wall (Figure 20-10). It is passed a second time to grasp the other end of the suture so that separate transfascial passes are performed. These sutures are circumferentially secured, and in this way the mesh is fixed in place. For patients with defects involving the lower abdominal wall in the midline, the mesh is placed down into the retropubic space and extends into the iliac fossa bilaterally. A Vicryl suture in the retropubic fascia to secure the mesh at this point is generally all that is required inferiorly.
Use of an 11-blade to incise the skin, creating small stab wounds for passage of the Endo Close device.
The Endo Close device is passed through the anterior abdominal wall to grab the suture.
Drains are placed bilaterally, and maintained for at least 5 days. They are removed once the volume is 40 cc or less for 24 hours. Seroma accumulation around the mesh can disrupt the repair by displacing the mesh and must be avoided.
When the cancer procedure is complete, the surgeon can proceed with groin hernia repair. Once the peritoneal sac is reduced from the myopectineal orifice and retracted cephalad, a large piece of polypropylene mesh is fashioned into the shape of a chevron, with the two extensions of the V placed into the iliac fossa bilaterally. The apex of the V should be secured with an absorbable stitch to the retropubic fascia, and the mesh should extend above the sac for 10 to 18 cm and extend around the sac bilaterally, essentially enveloping it (see Figure 20-4).
Either intermediate or lightweight polypropylene mesh can be used for repair of groin hernia using this approach. If bowel loops cannot be excluded from the mesh, then composite mesh (in patients at low risk for adhesions/infection) or a biologic implant (in patients at higher risk for adhesions or infection) can be used. Use of a biologic intraperitoneal prosthesis requires more fixation because the sutures hold the mesh in place until the mesh integrates into the surrounding tissue.
Box 20-3 PERIOPERATIVE MORBIDITY
A surgical binder can be useful postoperatively by providing the patient with some degree of abdominal wall support. Excessive pulmonary toilet should be avoided (ie, excessive coughing), and ambulation encouraged. Drains should be monitored carefully, and not discontinued until significant drainage ceases.
Surgical drains are essential in patients undergoing placement of synthetic mesh or a biologic implant. Drains should be left in place until the volume diminishes to less than 40 cc for 24 hours, and should be maintained for the first 3 days postoperatively even if the volume is low. Drainage will increase as the patient becomes more active. Postoperative seromas complicate mesh or bioprosthesis integration, and when unattended, they can disrupt the repair and increase the risk of a mesh infection.
Ambulation is essential for recovery, and patients who undergo incisional hernia repair should be encouraged to increase their distance daily, especially after hospital discharge. This will facilitate return of normal bowel function, aid in pain control, and promote optimal wound healing.
Most of the perioperative morbidity experienced by patients undergoing hernia repair or abdominal wall reconstruction can be attributed to the cancer operation. Abdominal wall bleeding following retrorectus mesh placement can occur, and this is manifested by fullness and bruising of the soft tissues of the abdominal wall. It is uncommon to return to the operating room for control. The epigastric vessels course along the posterior/lateral border of the rectus muscle, particularly in the lower abdominal wall. Care must be taken to avoid or ligate these as encountered, especially during drain placement and mesh fixation.
Many patients with abdominal wall hernias are obese, and wound infection can be both a cause and a result of incisional hernia. The triad of obesity/infection/hernia is well known to experienced surgeons. We have found that a negative pressure dressing on a closed wound (Prevena, KCI, San Antonio, Texas) may decrease the risk of wound infection in these high-risk patients. Our initial experience has been promising. This wound covering is left on for 5 to 6 days and can be used on a wound closed with staples or suture. Surgical glue is not applied to the wound if use of this wound covering is planned.
There is considerable confusion in the literature regarding the issue of mesh infection. Polypropylene mesh is a useful synthetic, and can usually be salvaged in the setting of a deep wound infection, with careful attention to drainage of all collections and timely and appropriate use of antibiotics. It is distinctly unusual, in my experience, to have to remove a polypropylene mesh in a patient with a deep wound infection. In patients with exposed bridging mesh (external oblique reconstruction), debridement of the superficial mesh may be required, but the underlay or sublay mesh is usually salvageable. In a patient who continues to have a nonhealing wound, fever, or wound drainage, complete or subtotal mesh removal may be required. Prolonged courses of antibiotic therapy should be avoided, as these inevitably lead to the development of resistant organisms and delay the eventual therapy required, which is foreign body (ie, mesh) removal.
One of the most important advantages to a biologic implant is that it is less susceptible to infection. In addition, if infection occurs, the biologic implant will often disintegrate without having to be surgically removed. If removal is necessary, the nonadherent parts of the biologic implant can be removed, and if the other portions are integrated and vascularized, these can be left in place. However, infection may occur with any mesh or implant, and considerable judgment is required to recognize an underlying mesh infection that will require explant from one that can be addressed with antibiotic therapy and drainage of associated collections.
Box 20-4 DELAYED COMPLICATIONS
The retrorectus synthetic mesh repair of incisional hernia is the “gold standard” repair of incisional hernia. Traditionally, a standard polypropylene mesh was used. Over time, it became clear that this mesh would shrink and stiffen, leading to abdominal wall discomfort in some patients. The use of this standard polypropylene mesh has largely been replaced by more “lightweight” meshes. These include the wider weave intermediate weight mesh and even wider weave “lightweight” mesh. Both options are suitable for repair of incisional or groin hernia; though in patients at very high risk for recurrence, this author prefers the intermediate weight mesh. However, it is important to remember that surgical technique is probably more important than tensile mesh strength. When placed carefully and secured without tension, a lightweight mesh with a wide weave is an excellent choice.
Recurrence following initial repair of an incisional hernia in a reasonable risk patient using the Stoppa technique is about 10% to 15%. Most recurrences will become apparent in the first 2 years, but some occur 5 or more years after repair. Often the area of recurrence is small, and the patient may elect not to undertake repair. If the recurrence is symptomatic and the patient requests repair, a smaller procedure with an intraperitoneal, preformed “patch” is often sufficient. It is not necessary or advisable to remove the previously placed retrorectus mesh. Preformed meshes that are useful for small defects include the C-Qur V-Patch or Proceed Ventral Patch. These come in several sizes depending on the size of the defect to be repaired.
Delayed mesh infection is becoming more common, for reasons that are somewhat unclear. When it occurs, it is highly likely that removal of the mesh will be required because it represents an infection of the mesh itself and not contamination of a portion of the mesh from a deep wound injection. Drainage of all localized collections and a trial of antibiotic therapy are the mainstays of initial care, but if this strategy fails, the mesh should be surgically removed. If the patient has had a prior polytetrafluoroethylene mesh placed and this has become infected, there is no need for antibiotics. The mesh must be removed, and the infection will never be eradicated without complete removal of the implant. I do not use mesh composed of polytetrafluoroethylene because of the risk of infection requiring explant.
As discussed, extraperitoneal placement of the repair mesh is ideal. This will make a bowel fistula related to the mesh nearly impossible. When extraperitoneal placement is not feasible, an intraperitoneal composite mesh is used. Despite the best efforts of surgeons and bioprosthetic engineers, a foreign body within the peritoneal cavity provides an opportunity for bowel adhesion. This is particularly true of patients without to act as a layer between the bowel and the mesh or implant, as well as patients at risk for bowel adhesion because of extensive lysis of adhesions, prior radiation, and/or bowel resection. In a patient at high risk for adhesions to an intraperitoneal mesh, a biologic implant should be used either as the repair mesh or to reconstruct the peritoneal cavity prior to synthetic sublay repair. This will minimize, but not eliminate, the risk of this difficult complication. If obstruction occurs, then fistula risk increases, as dilated loops of bowel press up against the intraperitoneal foreign body. A fistula may ensue and manifest as enteric drainage into the wound. Management with bowel rest and parental nutrition will usually result in resolution, and removal of the mesh may subsequently eventually be required.
MINIMALLY INVASIVE SURGICAL APPLICATIONS
Minimally invasive techniques can be employed for the repair of incisional hernia. The disadvantage of these techniques is that the mesh is always intraperitoneal, an issue whose implications we have discussed. However, careful selection of patients will identify those in whom this approach is appropriate.
Reconstruction of the groin, abdominal wall, or both following cancer surgery is an essential component of the care of the patient with a gynecologic malignancy. Abdominal wall defects create significant problems for patients recovering from surgery and negatively impact on their quality of life. Cancer surgeons should understand how to repair these defects and be familiar with the array of synthetic and biologic prosthetics available to accomplish repair or reconstruction of the abdominal wall. This will ensure that their patients will enjoy optimal oncologic and functional outcomes.
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