In the 20th century the diagnosis and management of an inguinal hernia was based on the following 2 concepts: (1) all groin hernias should be repaired at diagnosis to prevent a hernia accident (defined as strangulation and/or bowel obstruction) and (2) the Bassini classical sutured repair or one of its modifications, such as the Shouldice technique, is the preferred operation by most surgeons. However, the past 25 years have seen a dramatic shift in many aspects of groin hernia management, including indications for surgery, replacement of the tissue repair with the prosthetic-based tension-free repair, and the application of laparoscopic and now robotic principles. In this chapter, we will try to emphasize some important concepts in the management of inguinal hernia as discussed by the authors and provide a different point of view in certain other areas.

Male gender, increasing age, and a family history of groin hernias are proven risk factors for groin hernias in adults.^1,2 Smoking, thoracic or abdominal aortic aneurysm, history of open appendectomy, and peritoneal dialysis have also been implicated as causes of hernia.^1-3 Intra-abdominal tumor, ascites, chronic obstructive pulmonary disease, chronic constipation, pregnancy, and chronic urinary retention may lead to progression. Surprisingly, the role of obesity does not seem to be as significant and may actually be protective.^4,5 At the molecular level, disorders of collagen metabolism in the extracellular matrix can lead to a decreased type I (strong) to type III (weak) collagen ratio. Similarly, abnormal protein metabolism related to the matrix metalloproteinases responsible for collagen degradation and restoration can lead to connective tissue disorders such as osteogenesis imperfecta, Marfan syndrome, and Ehlers-Danlos syndrome.^6-9

Whether weight lifting is a risk factor remains controversial. A recent systematic review revealed inconclusive results about whether occasional heavy lifting, repeated heavy lifting, or a single strenuous lifting episode can lead to the development of groin hernia.¹⁰ The fact that weight lifters do not have increased incidence of inguinal hernias supports this result.⁴

Pregnant patients occasionally present with a swelling in the groin that by physical examination appears to be an obvious inguinal hernia. Before recommending surgical correction, it is imperative that varicosities of the round ligament be ruled out by ultrasound. There have been multiple case reports and small series of pregnant patients undergoing groin exploration only to find this condition.¹¹

None of the currently available groin hernia classification systems have been accepted as a gold standard, and differentiating a direct from indirect hernia is now more of an exercise for medical students and trainees. Imaging helps differentiate an inguinal from a femoral hernia in clinically occult hernias, but significant operator variability mars the utility of ultrasonography in these cases. Studies support the use of magnetic resonance imaging (MRI) over ultrasonography or computed tomography (CT) scan for such occult hernias.¹²

Watchful Waiting

Historically, routine surgical repair soon after diagnosis has been the recommended treatment for an inguinal hernia based on the fact that managing an inguinal hernia electively is much simpler than managing a hernia accident emergently. This concept has now been challenged as randomized controlled trials have shown that patients with minimally symptomatic inguinal hernias can be safely watched and operation deferred. However, long-term follow-up studies have demonstrated that the majority of patients undergoing watchful waiting (WW) will cross over to surgery because of symptom progression. It must be emphasized that WW is not recommended for any femoral hernia because of the significant risk of hernia accident. WW is also not an option for females primarily because of the difficulty in accurately differentiating their femoral hernias from inguinal hernias by means of physical examination.^13-16

Surgical Considerations

ANESTHESIA

Despite the fact that local anesthesia is safer and results in less urinary retention, the vast majority of inguinal herniorrhaphies are performed under general or regional (epidural or spinal) anesthesia, as shown by epidemiologic data from Europe.¹⁷ Currently, regional anesthesia is felt to be the least safe and is recommended only in unusual circumstances.

SURGICAL TECHNIQUES

Numerous named operations for the repair of an inguinal hernia can be found in the literature, making a detailed description of all of them impractical. Indeed, over 70 named nonprosthetic tissue repairs have been described since Bassini introduced the concept in 1887.¹⁸ In Table 12-1, we classify these various procedures based on the space they are performed in (anterior or preperitoneal), the type of repair (tissue or prosthetic), and whether they are conventional or robotic. Since most of the named operations are minor modifications of the established ones, representative procedures have been selected for Table 12-1 and are described in some detail below.

Anterior Repairs

There are several steps common to all anterior repairs, whether prosthetic or nonprosthetic:

1. 
   

   Cutaneous incision: Identification of the anterior superior iliac spine, symphysis pubis, and pubic tubercle.

   
   
2. 
   

   Incision of external oblique: Exposure of the external oblique aponeurosis and incision through the superficial ring of the inguinal canal.

   
   
3. 
   

   Isolating the cord structures: Lifting the cord structures from the inguinal canal at the pubic tubercle and then dissecting laterally to the deep inguinal ring, completely isolating the cord structures.

   
   
4. 
   

   Nerve disposition: Routine division of the iliohypogastric and the ilioinguinal nerves is performed by some at this point but is not generally advised.

   
   
5. 
   

   Separation of the cremaster muscle from the sac: The cremaster muscle is incised longitudinally for the length of the cord. If a lipoma of the cord is found, it is removed.

   
   
6. 
   

   Isolation of the spermatic cord from the sac: The cord should be dissected to determine if there is an indirect sac even if there is an obvious direct inguinal hernia. If an indirect sac is found, it should be ligated as proximal as possible and the distal end amputated. Many surgeons now prefer to simply reduce the sac back into the preperitoneal space, feeling that either opening or excising the sac is unnecessary.

   
   
7. 
   

   Reconstruction of the inguinal floor: This step varies.

   
   
8. 
   

   Closure of the external oblique aponeurosis: The external oblique aponeurosis is closed and the external ring is reconstructed.

Conventional Anterior Nonprosthetic Repair