Page 8 - International guidelines for groin hernia management

Hernia

Evidence in literature • Pulmonary disease (COPD and chronic cough possibly
A medical literature search for primary IH risk factors increasing the risk of IH formation). 48, 49
identified 989 studies. Included are a discussion of one
Liver disease, renal disease and alcohol consumption
systematic review, two randomized controlled trials
have not been properly investigated to determine if they are
(RCTs), 24 cohort or registry studies, five case–control
risk factors for IH formation.
studies and five diagnostic studies in the material below.
Recurrent inguinal hernia
A medical literature search for RIH risk factors identi-
Risk factors for RIH with a high level of evidence include
fied 1191 studies. A discussion follows of two systematic 49–59 58, 59
female gender, direct versus indirect IH, annual IH
reviews, two RCTs, 31 cohort or registry studies, one case– 60
repair volume of less than five cases and limited surgical
control study and four diagnostic studies. 56, 61–68
experience. However, this last risk factor may be
Primary inguinal hernia 69–72
modifiable by surgical coaching.
The lifelong cumulative incidence of IH repair in adults is Risk factors for RIH with a moderate level of evidence
27–42.5% for men and 3–5.8% for women. 14–17 73
include: presence of a sliding hernia, a diminished col-
Risk factors associated with IH formation (evidence 40, 74, 75
lagen type I/III ratio, increased systemic matrix
level—high): 42, 59, 74, 75 37, 59
metalloproteinase levels, obesity (although
• Inheritance (first degree relatives diagnosed with IH questioned in two very small studies 57, 76 ) and open hernia
elevates IH incidence, especially in females). 18, 19 repair under local anesthesia by general surgeons. 53, 77 A
• Gender (IH repair is approximately 8–10 times more recent meta-analysis examining features of
common in males). 100,000–200,000 repairs demonstrated that size (\ 3 ver-
• Age (peak prevalence at 5 years, primarily indirect and sus C 3 cm) and bilaterality did not affect the risk of
70–80 years, primarily direct). 16, 20–22 recurrence. 59
• Collagen metabolism (a diminished collagen type I/III Incorrect surgical technique is likely the most important
ratio). reason for recurrence after primary IH repair. Within this
• Prostatectomy history (especially open radical). 23–35 broad category of poor surgical technique are included:
• Obesity (inversely correlated with IH lack of mesh overlap, improper mesh choice, lack of proper
incidence). 19, 21, 36–38 mesh fixation, amongst others.
Several other potential risk factors have not been well
Risk factors associated with IH formation (evidence
studied or have low or very low levels of evidence sup-
level—moderate):
porting an association. Early postoperative hematoma for-
78 50, 52, 58, 59
• Primary hernia type (both indirect and direct subtypes mation and emergent surgery may be risk
are bilaterally associated). 39 factors for hernia recurrence but the association is not
• Increased systemic levels of matrix metalloproteinase- conclusive. Low (1–7 drinks/week) versus no ethanol
2. 40–43 consumption may protect against hernia recurrence. The
• Rare connective tissue disorders (e.g. Ehlers–Danlos effect of high ethanol consumption is unclear. 53 Increased
syndrome). 44 age, 57, 59, 79, 80 COPD, 57, 59, 76–82 prostatectomy, 76 surgical
site infection, 78, 83 cirrhosis, 84 chronic constipation, 76 a
Risk factors associated with IH formation (evidence 80, 85 53, 57, 80, 85
positive family history. and smoking. have
level—low):
not been consistently shown to be risk factors for RIH.
• Race (IHs are significantly less common in black Incompletely studied factors which may impact the risk of
adults). 21 IH recurrence are chronic kidney disease, social class,
• Chronic constipation. 19, 45 occupation, work load, pregnancy, labor, race and post-
• Tobacco use (inversely correlated with IH incidence). 37 operative seroma occurrence.
• Socio-occupational factors. Conclusion: several demographic (anatomy, female gender,
abnormal collagen metabolism), acquired (obesity), and
There is contradictory evidence that social class, occu-
perioperative risk factors (insufficient surgical technique,
pational factors and work load affect the risk of IH low surgical volume, surgical inexperience and local
repair. 46, 47 Heavy lifting may predispose to IH
48 anesthesia) for RIH were identified. Risk factors for IH and
formation.
RIH are not comparable. In daily surgical practice, atten-
Risk factors associated with IH formation (evidence
tion should be paid to perioperative surgical factors as they
level—very low):
are modifiable. Allocation arms in future outcome studies
should be balanced according to these demographic and
acquired risk factors.

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