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Page 6 of 9 O’Connor et al. Plast Aesthet Res 2019;6:26 I http://dx.doi.org/10.20517/2347-9264.2019.38

or feculent drainage and require multiple interventions and hospital admissions to resolve. The literature
suggests that avoidance of enterotomies at the index operation is the best way to prevent fistula formation
post operatively. In a large database review of elective ventral hernia repairs, enterotomy or unplanned
bowel resection (EBR) increased the ECF formation rate from 0.7% to 7.1% (P < 0.01). The authors found
that repair of recurrent hernias where mesh had been placed at the index operation had a significantly
higher rate of EBR compared to primary hernia repair or recurrent repair after prior suture repair alone
(20.4% vs. 5.7%, P < 0.001). This highlights the difficulty of reoperative hernia surgery and the importance
of meticulous lysis of adhesions to prevent devastating complications in the future [7,30] .

For many years, it has been thought that PP mesh would have a higher risk of ECF formation due to
the vigorous foreign body response and inflammation it incites when compared to polyester or PTFE.
However, long-term data on retrorectus technique have shown no increased ECF formation with PP mesh
[32]
[31]
when compared to PTFE . This was further supported by Brandi et al. , who reported no ECF even with
uncoated polypropylene mesh in the intraperitoneal position.
Management of ECF should start with conservative measures and control of contamination, because
immediate mesh explanation is associated with a high risk of EBR, which could result in even further fistula
[7]
formation . Macroporous polypropylene and polyester mesh are more likely to be salvaged than PTFE
due to its poor tissue ingrowth and biofilm formation. Conservative management should include opening
the tract to control sepsis, nutritional support with TPN, somatostatin, downstream decompression, and
[33]
appropriate wound care, which can lead to spontaneous closure in many cases . If the fistula fails to close, it
is recommended to wait for 6 month to allow for spontaneous closure and maturing of adhesions before mesh
[35]
[34]
excision and bowel resection is undertaken . In a recent review of the AHSQC database, Kao et al. looked
at outcomes from partial mesh excision (PME) vs. complete mesh excision in clean, clean-contaminated,
contaminated, and dirty wounds as well as cases with ECF. Not surprisingly, they found a higher rate of SSI,
[35]
SSO, SSOPI, and reoperation in the PME group in cases of ECF, contaminated or dirty wounds . In the
case of mesh infection or fistula, all permanent pieces of mesh and suture should be removed as they will
serves as a nidus for future infection or wound complications.

Hernia recurrence
It is well established at this point that placement of synthetic mesh during hernia repair reduces hernia
recurrence rates compared to suture repair alone. The largest study on recurrence was on the Denmark
national health system data bank, which followed 3242 patients for a median of 5 years and found a 12.3%
[36]
recurrence rate with mesh compared to 17.1% without . The most common site of recurrence is in the
[37]
midline directly through central fractures in the mesh, accounting for up to 39.6% of recurrences . Factors
that increase the risk of mesh fracture can be both technical in nature and due to material weakness. There
has been a shift in mesh material towards lightweight mesh due to its improved flexibility and decreased
[38]
shrinkage over time as there is less inflammatory reaction to a decreased volume of material . However,
this comes at the price of decreasing its overall strength, especially when combined with a macroporous
[39]
configuration to allow for bacterial clearance. Petro et al. recently published their experience with
macroporous lightweight polyester placed in the retrorectus position on 36 patients. Of the eight (22%)
recurrences after 13 months, seven (19%) were found to have a central mesh fracture as the mechanism of
[37]
recurrence. Warren et al. also found that the use of lightweight polypropylene mesh was an independent
risk factor for central mesh fracture. Because of this, medium- or heavyweight mesh is recommended,
especially when using a macroporous mesh.

While the material of the mesh itself may be partially to blame, there are also technical factors that place
patients at risk for central mesh fracture. Failure to close the midline or midline dehiscence leaves the mesh
unsupported by the abdominal wall, causing increased stress and eventual fracture of the mesh. There is