Open Inguinal Hernia Repair Technique

Inguinal hernia repairs are of the following three general types:

• Herniotomy (removal of the hernial sac only)
• Herniorrhaphy (herniotomy plus repair of the posterior wall of the inguinal canal
• Hernioplasty (herniotomy plus reinforcement of the posterior wall of the inguinal canal with a synthetic mesh)

The ensuing discussion focuses primarily on the Lichtenstein tension-free mesh repair, which is an example of hernioplasty and is currently one of the most popular techniques of inguinal hernia repair. ^{[6, 7]} The Bassini, Shouldice, and darn repairs (all examples of herniorrhaphy) are also briefly discussed. The key technical point is that in the Lichtenstein tension-free repair, there is no attempt to repair the posterior wall, as is done in Bassini or Shouldice repairs; the weak posterior wall is reinforced with mesh.

Incision

The incision is placed about 1 cm above and parallel to the inguinal ligament, beginning from the pubic tubercle and extending 5-6 cm laterally up to the midinguinal point (see the images below). The subcutaneous fat is then opened along the length of the incision, and careful hemostasis is achieved by ligating superficial pudendal and superficial epigastric vessels.

The Scarpa fascia is similarly opened along the length of the incision, down to the external oblique aponeurosis, and the external inguinal ring and the lower border of the inguinal ligament are visualized (see the images below). Below the inguinal ligament, on the medial aspect, the deep fascia of the thigh is opened, the femoral canal exposed, and a check made for any concomitant femoral hernia. Although the risk is very low, routine exploration of the femoral canal is advised in the absence of an inguinal hernia and in women. ^[5]

Division of external oblique aponeurosis and exposure of inguinal canal

The external oblique aponeurosis is then opened along the line of incision, starting from the external ring and extending laterally for up to 5 cm (see the image below). The ilioinguinal nerve, lying underneath the aponeurosis, is safeguarded during this procedure.

The superior and inferior flaps of the external oblique aponeurosis are gently freed from the underlying contents of the inguinal canal and overturned and separated to expose the cremaster with the cord structures, the ilioinguinal and iliohypogastric nerves, the uppermost aponeurotic portion of the internal oblique muscle and conjoined tendon, and the free lower border of the inguinal ligament (see the images below). Wide separation of the two flaps provides ample space for placement and fixation of mesh under vision while protecting the nerves.

Dissection of spermatic cord

The spermatic cord, along with the cremaster, is then lifted up and separated from the pubic bone for about 2 cm beyond the pubic tubercle to create space for extending the mesh well beyond the pubic tubercle.

When lifting the cord, the surgeon must be sure to include the ilioinguinal nerve, the genitofemoral nerve, and the spermatic vessels along with it. All of these structures may then be encircled in a tape for ease of handling. The anatomic plane between the cremaster and the aponeurotic tissue attached to the pubic bone is avascular, and cord structures encircled in the tape can be separated from the floor of the inguinal canal up to the internal ring. (See the images below.)

A visible landmark for safeguarding the genitofemoral nerve is the external spermatic vein, usually referred to as the “blue line.” If the blue line is kept with the spermatic cord, the surgeon can be sure that the genital branch of the genitofemoral nerve, which is always adjacent to this vein, is well protected. ^[54]

Identification and management of hernia sac

The cord structures and all of the nerves of the inguinal canal having been visualized, the next step is to identify and isolate the hernia sac. The patient is asked to cough, and the groin region is examined for the presence of an indirect hernia, a direct hernia, a femoral hernia, a combined hernia, or a spigelian hernia.

A hernia sac can be managed by means of inversion, division, resection, or ligation. Resection and ligation of a small hernia sac should not be performed unnecessarily, because postoperative pain commonly results. However, the hernia sac must be well separated from the internal ring before it is invaginated. The risk of recurrence is not increased when a small or medium-sized indirect hernia sac is not ligated. ^[54] Excision of an indirect inguinal hernia sac is associated with a lower risk of hernia recurrence than is division or invagination. ^[55]

When the hernia sac is excised or divided, the proximal sac should never be left open; doing so may lead to recurrence. The proximal sac is dissected free of cord structures well above the internal ring, and a high ligation of the neck of the sac should be performed.

The indirect hernia sac lies anterolateral to the cord structures and is visualized by dividing the cremaster muscle longitudinally (see the image below). The cremaster muscle should not be divided transversely or excised, because doing so may result in low-lying testes and dysejaculation.

The peritoneal sac is identified and separated from the spermatic vessels and the vas deferens up to its neck (see the images below). A small or medium-sized hernia sac may be isolated and inverted into the preperitoneal space without suture ligation. For a voluminous scrotal hernia sac, no attempt should be made to dissect it completely and excise it; such an attempt can result in ischemic orchitis. ^[5]

The neck of a large hernia sac is transected at the midpoint of the inguinal canal (see the first image below), and the proximal part is suture-ligated. A high ligation of the proximal sac is recommended, and the stump is reduced deep underneath the internal ring (see the second image below). The distal sac is left in place; however, the anterior wall of the distal sac is incised to prevent postoperative hydrocele formation (see the third image below).

A direct inguinal hernia lies posteromedial to the cord structures. The direct hernia sac is isolated and dissected free. Its contents are reduced, and the peritoneal sac is inverted and maintained in position with a purse-string suture.

If a femoral hernia is suspected, the femoral ring should be evaluated by incising the medial part of the iliopubic tract. If a sac is seen entering the femoral ring, it is reduced and dealt with by inverting or ligating the neck of the sac. A spigelian hernia is managed in a similar manner. A sliding hernia is simply dissected free and inverted in the preperitoneal space.

Placement and fixation of mesh

A 7.5 × 15 cm piece of polypropylene mesh is commonly used for a Lichtenstein hernioplasty. On the medial side, the sharp corners of the mesh are trimmed to conform to the patient’s anatomy. For a femoral hernia, the mesh is tailored so that it has a triangular extension from its lower edge on its medial side.

To compensate for future shrinkage, the mesh should be wide enough to extend 3-4 cm beyond the boundary of the inguinal triangle. To compensate for increased intra-abdominal pressure when the patient stands up, the mesh should be placed lax in the posterior wall of the inguinal canal in such a way that it acquires a domelike wrinkle.

The first medialmost stitch fixes the mesh 2 cm medial to the pubic tubercle, where the anterior rectus sheath inserts into the pubic bone (see the image below). Care should be taken not to pass the needle through the periosteum of the bone or through the pubic tubercle; this is one of the most common causes of chronic postoperative pain.

The same suture is then used as a continuous suture to fix the lower edge of the mesh to the free lower border of inguinal ligament up to a point just lateral to the internal ring (see the images below). No more than four or five passes are required.

For a femoral hernia, the medial portion of the iliopubic tract is excised, and the Cooper ligament is exposed. The lower triangular extension on the medial side of the mesh is stitched to the Cooper ligament, and the suture is continued to fix the lower edge of the mesh to the inguinal ligament, as above.

Next, a slit is made in the lateral end of the mesh to create a narrower lower tail (the lower one third) and a wider upper tail (the upper two thirds). The slit extends up to a point just medial to the internal inguinal ring (see the image below).

The upper tail is then passed underneath the cord in such a way as to position the mesh posterior to the cord in the inguinal canal (see the image below), and the spermatic cord is placed between the two tails of the mesh. The upper tail is then crossed over the lower one, and the two tails are held in an artery forceps.

With the mesh kept lax, its upper edge is then fixed to the rectus sheath and the internal oblique aponeurosis with two or three interrupted nonabsorbable sutures (see the first image below). On occasion, the iliohypogastric nerve is found to be in the way of upper edge of the mesh. In such cases, the mesh may be split to accommodate the nerve (see the second image below).

The two tails are then tucked together and fixed to the inguinal ligament just lateral to the internal ring, thus creating a new internal ring made of mesh (see the first image below). The tails are trimmed 5 cm beyond the internal ring and placed underneath the external oblique aponeurosis (see the second image below).

Suturing the mesh beyond the internal ring is unnecessary; doing so may cause injury to the femoral nerve. Similarly, fixation of the tails of the mesh to the internal oblique muscle, lateral to the internal ring, may cause entrapment of the ilioinguinal nerve. Trying to suture the two tails without crossing them or trimming the tails shorter than 5-6 cm beyond the internal ring may result in recurrence at the deep inguinal ring. ^[54]

If any of the nerves is injured or of doubtful integrity, it can be resected and its proximal end ligated and buried within the fibers of the internal oblique muscle to keep the stump of the nerve away from scarring.

In male patients, the testes should always be gently pulled back down to their normal scrotal position after fixation of the mesh.

Closure

Spermatic cord layers are closed with fine sutures, with care taken to avoid damaging the cord contents. Hemostasis is ensured in the inguinal canal, which is then closed by suturing the two flaps of the external oblique aponeurosis (see the images below), with care taken not to injure the underlying ilioinguinal nerve. Suturing is started laterally and continued medially, where an adequate opening is left at the newly created superficial inguinal ring so as not to occlude the emerging spermatic cord.

Subcutaneous tissue is approximated with interrupted sutures to obliterate any dead space, and the skin is approximated with sutures, clips, or adhesive strips (see the images below). A subcuticular continuous stitch with 3-0 absorbable sutures obviates any need for stitch or clip removal and provides better cosmetic results.

The operative site is cleaned and a sterile dressing applied. Local infiltration of a long-acting anesthetic agent (eg, bupivacaine or ropivacaine) into the subcutaneous tissue around the incision provides good immediate postoperative pain relief. A bupivacaine-containing bioresorbable collagen implant is available for management of pain after open inguinal hernia surgery. ^[56]

Open inguinal hernia repairs other than Lichtenstein hernioplasty are not merely of historical interest. Surgeons must know and understand these repairs so that they can be carried out when they are appropriate. Specifically, cases that involve a contaminated field (eg, necrotic or perforated bowel secondary to hernial strangulation) are not amenable to prosthetic repair. In such cases, either a primary tissue repair or a biologic implant repair is necessary. ^{[57, 31, 32]}

Plug-and-patch repair

The plug-and-patch repair adds a polypropylene plug shaped as a cone, which can be deployed into the internal ring after reduction of an indirect sac. The plug then acts as a toggle bolt to reinforce the defect.

Prolene Hernia System

The Prolene Hernia System (PHS) consists of an anterior oval polypropylene mesh connected to a posterior circular component. The posterior component is deployed in a bluntly created preperitoneal space (see the first image below). The anterior portion is then laid out with a cut made to recreate the internal ring (see the second image below). The anterior portion is then sutured above to the conjoined tendon and below to the shelving edge of the inguinal ligament and is tucked behind the external oblique aponeurosis (see the third image below).

McVay repair

In the McVay repair, the conjoined (transversus abdominis and internal oblique) tendon is sutured to the Cooper ligament with interrupted nonabsorbable sutures.

Bassini repair

The Bassini technique for inguinal hernia repair involves suturing the transversalis fascia and the conjoined tendon to the inguinal ligament behind the spermatic cord with monofilament nonabsorbable suture. It also involves the so-called Tanner slide, which is a vertical relaxing incision in the anterior rectus sheath intended to prevent tension.

Shouldice repair

The Shouldice technique is a four-layer inguinal hernia repair performed with the patient under local anesthesia. The transversalis fascia is incised from the internal ring laterally to the pubic tubercle medially, and upper and lower flaps are created. These flaps are then overlapped (double-breasted) with two layers of sutures.

The conjoined tendon is then sutured to the inguinal ligament, again in two overlapping layers. This reinforces the posterior wall and narrows the deep inguinal ring. The Shouldice repair is classically done with a continuous suture of 32- to 34-gauge stainless steel wire, but synthetic monofilaments (eg, polypropylene) can also be used. The external oblique aponeurosis is then closed in a double-breasted fashion in front of the spermatic cord.

Darn repair

A darn inguinal hernia repair is a pure-tissue tensionless technique that is performed by placing a continuous suture between the conjoined tendon and the inguinal ligament without approximating the two structures.

Acellular dermal implant

Some reports describing the use of an acellular dermal implant (eg, AlloDerm; LifeCell, Bridgewater, NJ) in cases where the surgical field is contaminated have appeared in the literature, but long-term results are not yet available. ^{[30, 37]}

After the procedure, the patient is asked to rest for few hours. He or she may be discharged later the same day on a day-care basis. Early mobilization is the key to rapid convalescence. Patients can safely ambulate on the evening of the operation. If general or regional anesthesia is used, the patient may be hospitalized for a few days.

There is some pain in the postoperative period, and suitable analgesics should be prescribed. The dressing is removed on postoperative day 5, and stitches are removed on postoperative day 7. Patients should be advised to avoid strenuous activities for a few weeks. Typically, light work can be resumed after 1 week, heavier jobs after 6 weeks.

Male patients should be monitored for testicular atrophy, which may occur as a result of venous or arterial injury or obstruction in the spermatic cord. All patients should be monitored for the development of nerve pain from nerve entrapment in suture material. Finally, patients should be monitored for recurrence, which may arise as a consequence of inadequate repair, wound infection, or chronic straining (eg, from coughing, constipation, or urination).

In systematic reviews, the overall risk of complications after inguinal hernia surgery has been in the range of 15-28%. Complications may develop intraoperatively or postoperatively. Early postoperative complications include seroma formation and hematoma (8-22% of cases), urinary retention, and wound infection (1-7% of cases). Late postoperative complications include sensory loss, hyperesthesia, chronic inguinal pain, mesh-related problems, hydrocele, testicular pain, testicular swelling, atrophy, and recurrence of hernia.

Intraoperative complications

Intraoperative complications of open inguinal hernia repair include vascular injuries, injuries to abdominopelvic structures, and nerve injuries.

Vascular injuries

Superficial epigastric vessels in the incision may bleed. These vessels not only should be identified when the incision is being made but also should be ligated and divided. Inferior epigastric vessels may be injured during dissection of the spermatic cord in the inguinal canal, dissection of an indirect inguinal hernia sac within the spermatic cord, plication of the transversalis fascia, or transfixion of the hernial sac. These vessels should be identified at an early stage and protected.

External iliac or femoral vessels, especially veins, may be injured during fixation of the mesh to the inguinal ligament in its lateral part. The tissue bites in the inguinal ligament should not be very deep.

Although less common than other intraoperative complications, vascular injuries are potentially disastrous. They can be avoided by respecting the proximity of the femoral vessels, particularly when suturing the mesh to the inguinal ligament. Hematoma formation can result from injury of the inferior epigastric vessels or pampiniform plexus veins or from failure to ligate the superficial subcutaneous veins.

Injuries to abdominopelvic structures

Cord structures (eg, testicular artery, pampiniform plexus of veins, and vas deferens) may be injured during opening of the coverings of the spermatic cord or dissection of the indirect hernial sac within the spermatic cord. In particular, the surgeon should always be aware of the vas deferens and should protect it from injury.

Injury to the urinary bladder may occur during plication of the transversalis fascia. In addition, injury to the urinary bladder, cecum, or sigmoid colon may occur during transfixion of the hernial sac in a sliding indirect inguinal hernia (where these viscera are not contained in the hernial sac but form a part of the wall of the sac). A sliding hernia should be recognized early; if it is present, the entire hernial sac should not be excised.

Injury to the bowel may occur during transfixion of the neck of an indirect hernial sac. The head end of the operating table can be lowered to ensure complete reduction of contents of the sac, the sac can be twisted to push the contents into the peritoneal cavity, and a tissue bite can be taken and the suture tied under vision.

Nerve injuries

The iliohypogastric nerve, because it lies on the conjoined tendon outside the inguinal canal, may be injured during dissection of the upper flap of the external oblique aponeurosis or fixation of the mesh to the conjoined tendon. It may also become trapped in sutures during closure of the external oblique aponeurosis.

The ilioinguinal nerve, because it lies in the inguinal canal along with the spermatic cord, may be injured during dissection of the cord.

The genital branch of the genitofemoral nerve, because it lies within the spermatic cord, may be injured during dissection of the hernia sac.

Postoperative complications

Urinary retention

Urinary retention may occur after open inguinal hernia repair, especially in middle-aged and elderly male patients with prostatic enlargement. In a meta-analysis of 72 studies, the incidence of urinary retention after herniorrhaphy was 0.37% (33 of 8991 patients) with local anesthesia, 2.42% (150 of 6191 patients) with regional anesthesia, and 3% (344 of 11,471 patients) with general anesthesia. ^[5] Such retention is said to be due to the inhibitory effect of regional and general anesthesia on bladder function.

Seroma and hematoma

Most seromas disappear spontaneously within 6-8 weeks. If a seroma persists, it may be aspirated. A small hematoma may be treated conservatively. For larger hematomas, which are asymptomatic, evacuation under anesthesia should be considered. Meticulous dissection with adequate hemostasis will reduce the incidence of seroma and hematoma formation.

Infection

Deep and persistent infection may necessitate removal of the mesh. Wound infection can also weaken the repair and may be responsible for recurrence of the hernia.

Pain

Postoperative chronic pain is more frequent than was previously understood and has become one of the most important primary endpoints in hernia surgery. In published reports, the incidence of postherniorrhaphy pain has ranged from 0% to more than 30%. Chronic inguinodynia is defined as pain persisting more than 3 months post herniorrhaphy, after the process of wound healing is complete.

Nonfixation or inadequate mesh fixation results in folding and rolling of the mesh, which can cause chronic pain and recurrence of the hernia.

Chronic pain after mesh hernioplasty also results from neuroma formation after accidental division of the nerves. The ilioinguinal, iliohypogastric, and genitofemoral nerves are visualized and protected throughout the operation. They should not be dissected free from their natural bed; doing so can lead to perineural fibrosis and chronic pain postoperatively.

Deliberate sectioning of the nerves intraoperatively to prevent chronic groin pain has been described but is still controversial. Current recommendations consist of nerve identification, minimal handling, and preservation. ^[58] Prevention of nerve injury is very important because treatment of chronic neuralgias may not be successful.

Entrapment of a nerve by suture or mesh appears to be an important cause of postoperative pain. The groin nerves should be identified and protected. Fibrin or biologic glues may be used instead of sutures to secure the mesh. It appears that cyanoacrylate glue may be a viable alternative to sutures, and it is anticipated that the use of fewer sutures may be associated with less inguinodynia. ^[25]

Another cause of significant postherniorrhaphy pain is the placement of a stitch into the periosteum at the pubic tubercle for fixation of the mesh medially. This is often the point of maximal tenderness postoperatively. Therefore, one should avoid taking a deep bite through the periosteum of the pubic tubercle; tough, fibrous tissue in that region should instead be used for fixing the mesh.

The use of a low-density macroporous mesh with semiresorbable, self-fixing properties during tension-free repair may be a satisfactory solution to the clinical problems of pain and recurrence after inguinal herniorrhaphy. ^[59]

Hydrocele

Scrotal edema or hydrocele due to venous and lymphatic damage during dissection within the spermatic cord may also occur.

Ischemic orchitis and thrombosis

Ischemic orchitis leading to testicular atrophy is a rare but well-known complication of inguinal hernia surgery. The patient may complain of pain and testicular swelling postoperatively. Symptoms may last for 2-3 months, and testicular atrophy may occur. The rarity of this complication notwithstanding, the surgeon should maintain a high index of suspicion. Testicular ultrasonography and Doppler studies may facilitate early diagnosis and help avoid orchiectomy. Ischemic orchitis is thought to be secondary to venous thrombosis rather than arterial injury.

Thrombosis is caused by surgical trauma to the delicate veins of the pampiniform plexus and disruption of the collateral blood supply to the testes during an attempt at complete removal of a large hernia sac. It is also more likely in operations for recurrent hernia. It is thus advisable not to attempt complete dissection and excision of a large hernia sac. The neck of the hernia sac is transected at the midpoint of the inguinal canal, and the distal sac is left in place. However, the anterior wall of the distal sac is incised to prevent postoperative hydrocele.

Recurrence

The recurrence rate for Lichtenstein hernioplasty at specialist clinics in the United States is consistently less than 1%. In an audit of Lichtenstein hernioplasty performed with local anesthesia by surgical residents, the recurrence rate was 2.1% over a 10-year follow-up period.

Recurrence in Lichtenstein hernioplasty may be due to inaccurate execution of the technique (inadequate size or improper fixation of the mesh) or to an overlooked hernia at the primary operation. To avoid the latter, the patient should be asked to cough, and the region should be carefully examined for an indirect hernia, a direct hernia, a femoral hernia, or a combined hernia.

Recurrence may be more frequent in the presence of comorbid conditions (eg, chronic obstructive pulmonary disease) or obesity or with the use of steroids. Other contributing factors may be the use of too-small pieces of mesh placed flat under tension, failure to achieve adequate overlap (medially, 2 cm beyond the pubic tubercle; laterally, 5-6 cm beyond the internal ring), or failure to cross the tails of the mesh. A thorough clinical evaluation, a high degree of suspicion, and diligent follow-up are advised to keep track of recurrences.

Women, because of the higher frequency of femoral hernias, are at greater risk for recurrence (inguinal or femoral) after an open inguinal hernia operation than men are. In female patients, the existence of a femoral hernia should always be excluded by exposing the femoral canal. ^[5]