Turaga K, Fitzgibbons RJ, Puri V. Inguinal hernias: should we repair? Surg Clin N Am 88 (2008) 127-138.
Hernia repair surgery is seen as a prevention against life-threatening complications such as bowel obstruction or strangulation. It is also believed that progression of a hernia is inevitable and that the operation becomes more difficult the longer the hernia is left unrepaired. The Society of Surgery for the Alimentary Tract in the US recommends that patients with groin hernia should undergo surgical evaluation within a month after detection. Inguinal hernias are one of the most common afflictions of adult men. Herniorrhaphy is one of the most common surgical operations. 2,800 herniorrhaphies per 1 million population are performed per year in the US compared with 1,000 per million in the UK.
This paper reviews data to evaluate the probability of bowel obstruction or strangulation if a hernia repair operation is not performed.
A statistical evaluation was performed in a study by Hair and colleagues (2001). Of 699 patients admitted for surgery, 29% had had their hernia for 1-5 years and 8.8% for 5 years or longer. The probability of a hernia becoming painful was estimated to rise to 90% by 10 years. However this only restricted leisure activities in 29%. Only 13% of the employed patients had to take time off work due to hernia-related symptoms. The probability of irreducibility (inability to push the hernia back "in") rose from 6.5% at 12 months to 30% at 10 years. Only ten of the patients required emergency surgery. Thus the delay in performing surgery had minimal clinical significance in this series of patients.
In a study by Gallegos (1991) the cumulative probability of strangulation was found to be 2.8% at 3 months and 4.5% at 21 months.
In a 1977 study, Neuhauser studied data produced around 1896 for a group of 8,633 patients in a Paris truss clinic. In those days hernia repair surgery was rare. There were a total of 242 cases of bowel obstruction or strangulation (2.8%). Data from a 2nd group from 1965-66 were also studied, and suggested a probability of bowel obstruction or strangulation amounting to 0.0038% per year.
In a randomized controlled trial by Fitzgibbons (2006), 720 men from age 18 and over, with minimally symptomatic or asymptomatic inguinal hernias were randomized to watchful waiting (WW) or surgical repair. All the men were followed-up for at least 2 years and some were observed for as long as 4.5 years. There was no significant difference between the two groups in terms of pain or discomfort. One third of the men assigned to WW requested and received surgery, mostly because of increasing pain. Of these, 1.5 per cent had a recurrence of their hernia. 2 per cent suffered post-operative complications resulting in sustained long-term pain.
Two patients experienced acute hernia incarceration over the 5 years of the study. These results are equivalent to a hernia accident rate of less than 2 events per 1000 patients per year, or about 0.002% per year.
17 per cent of the men assigned to surgery never received surgery and continued with WW. There did not appear to be a penalty for delaying surgery when the delayed patients were compared with the group who received immediate surgery.
The author also compares this study with a trial carried out by O'Dwyer in 2006, in which pain developed in WW patients at a higher rate and crossover from WW to surgery was also higher. There was also a lower rate of post-operative complications. The author suggests that these differences can be explained by different clinical trial criteria.
Fitzgibbons trial
Asymptomatic patients at a very early stage of their hernia were included. Patients aged 18 years and over from a number of different centres were included. Patients were followed-up for up to 4.5 years.
O'Dwyer trial
The trial was restricted to more advanced hernias, and patients aged 55 years or more from one specialist hernia centre. Patients had to demonstrate visible swelling on standing. The lower rate of post-operative complications may be due to the fact this this is a specialist and highly skilled hernia centre.
Poobalan published a critical review of hernia repair studies between 1987 and 2000. The frequency of some degree of long-term post-operative pain was as high as 53% at 1 year. For an asymptomatic patient this risk is unacceptable.
The success of a hernia treatment should not be measured only in terms of its ability to prevent a recurrence of the hernia. The risk of complications without surgery should be weighed against the risk of complications caused by surgery. Bowel obstruction or strangulation occur only rarely and can be treated. The concern that a hernia may be more difficult to repair the longer it goes untreated was an issue before mesh repairs, when the integrity of the groin tissue was essential for a successful operation. This concern has largely been eliminated by use of mesh. The author concludes that WW is a safe and acceptable option for men with minimal or no symptoms.

Summary by Herniabible staff.
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