Matthew W. Ralls
Justin B. Dimick
Presentation
A 61-year-old man presents to the emergency department with obstipation and left groin mass for 3 days. His past medical history was notable for chronic obstructive pulmonary disease, type II diabetes, obesity, hyperlipidemia, and schizophrenia. His surgical history was significant for two prior inguinal hernia repairs on the left side. Due to his schizophrenia, he resides in an assisted living facility and comes in with a caregiver today. He describes an increase in abdominal pain and distention over the 3-day period. His oral intake has decreased, and he reports minimal urine output over the past 2 days. Physical exam is notable for a well-healed scar in the right lower quadrant at McBurney’s point and a large, 12- × 12-cm bulge in the left inguinal region. The mass is tender to palpation, erythematous, and nonreducible. Although the bulge has intermittently been present, both the patient and caregiver state that the size and tenderness are new in the past 2 days. Laboratory values were notable for a WBC of 8.7 and hematocrit of 42.4.
Differential Diagnosis
In a patient with an intermittent groin bulge that is now fixed, tender, and erythematous, complications of a groin hernia should be first consideration in the differential diagnosis. However, there are several other possible etiologies to consider. Subcutaneous pathology, such as lipoma, groin abscess, or inguinal adenopathy, can present as a groin mass. Testicular pathology comprising torsion and epididymitis should also be considered, especially when the mass involves the scrotum. Vascular etiologies, such as aneurysmal or pseudoaneurysmal disease, should be considered in patients with a history of vascular disease and/or previous interventions at or near the femoral vessels.
Once the surgeon suspects groin hernia, it is important to discern inguinal from femoral hernia. To some degree, this can be ascertained on physical exam. For a femoral hernia, the bulge is below (and lateral) to the medial end of the inguinal ligament. In contrast, in an inguinal hernia, the bulge would be above the inguinal ligament (Figure 1). However, this distinction can be difficult to assess if the bulge is large, tender, and inflamed.
FIGURE 1 • Landmarks in discerning inguinal (A) versus femoral (B) hernia. (From Mulholland MW, et al. Greenfield’s Surgery: Scientific Principles & Practice. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2006, with permission.)
Most importantly, early identification of complications of groin hernia, such as incarceration or strangulation, is essential. Such complications change the time course of intervention. Incarcerated hernias cannot be reduced and therefore may progress to strangulation if they have not already. Strangulated hernia is by definition a hernia in which the blood supply of the herniated viscus is compromised. For a reducible groin hernia, repair can be delayed and scheduled electively. But suspected incarceration and strangulation are surgical emergencies.
Workup
History and physical examination in patients with suspected incarcerated and/or inguinal hernia are often diagnostic. The decision to operate can often be made without further evaluation (Figure 2). Laboratory values such as complete blood count, comprehensive metabolic panel, and lactate level can provide information about the patient’s hydration status and whether there is systemic inflammatory response, which are important in assessing the likelihood of strangulation. However, these tests have a high sensitivity and low specificity, that is, most patients with incarceration and strangulation will have normal or near-normal laboratory values. To avoid a high false-negative rate (i.e., missing the diagnosis when it is present), surgeons should err on the side of exploring patients when incarceration/strangulation are suspected. If there is substantial uncertainty regarding the diagnosis, imaging studies can be obtained. If the patient is obstructed at the site of incarceration, plain films of the abdomen will show signs of distended loops of bowel and air fluid levels if the patient is obstructed (Figure 3). However, computed tomography (CT) imaging is the standard in emergency evaluation (Figure 4) if the clinical diagnosis is in question after history, physical, and plain abdominal radiographs.
FIGURE 2 • Erythema and swelling over left groin concerning for incarcerated hernia. This exam finding, coupled with appropriate presentation, is sufficient cause for exploration.
FIGURE 3 • Plain film of patient described in this clinical scenario. Distended loops of large bowel are concerning for a distal large bowel obstruction.
FIGURE 4 • CT showing left inguinal hernia.
Discussion
Inguinal hernia repair is one of the most commonly performed surgical procedures worldwide. Over 800,000 inguinal hernia repairs are performed in the United States each year. Despite being a very common operation, the relevant anatomy is complex and often difficult for students and surgical trainees to fully understand. An intimate knowledge of this anatomy, however, is important, especially for addressing incarcerated or recurrent inguinal hernias. In these settings, the distortion of the tissues makes operative repair extremely challenging. In 1804, Astley Cooper stated, “No disease of the human body, belonging to the province of the surgeon, requires in its treatment a greater combination of accurate anatomic knowledge, with surgical skill, than hernia in all its varieties.”
Over the past two centuries, there have been many advances in groin hernia repair. The most frequently used technique in contemporary surgical practice is the tension-free mesh repair, or Lichtenstein repair. The laparoscopic totally extraperitoneal (TEP) is emerging as the most frequent minimally invasive approach and allows for quicker recovery, less pain, and similar or lower recurrence rates in experienced hands. Primary tissue repairs, such as the Bassini and McVay, are rarely used. However, in certain settings, such as contaminated fields with infection or bowel resection, a working knowledge of primary tissue repairs is essential.
Symptomatic inguinal hernias that are reducible should be repaired on an elective basis. As discussed above, incarcerated hernias should be addressed more expeditiously. Surgery within 6 hours may prevent loss of bowel. Emergent repair differs little from elective repair. Either open or laparoscopic techniques are acceptable, although it is the preference of the author to utilize the open procedure if there is concern for strangulation. This is due to the tissue distortion and friability associated with acute inflammation.
Diagnosis and Treatment
The patient in our case presents with a scenario worrisome for incarcerated or strangulated inguinal hernia. He has a fixed bulge that is tender to palpation, which is typical of incarceration. He also presents with erythema in the overlying skin, which suggests possible strangulation. The patient also presents with radiographic evidence of large bowel obstruction (Figure 3 is his abdominal radiograph) with resultant obstipation and abdominal pain, with associated nausea and vomiting. Given the bowel obstruction in this patient, and the possible risk of strangulation, we will perform an open repair, beginning with an inguinal exploration.
Surgical Approach for Open Mesh Repair of Incarcerated Inguinal Hernia Repair (Table 1)
TABLE 1. Key Technical Steps in Open Inguinal Hernia Repair with Mesh
Open repair can often be done under general, spinal, or local anesthetic with sedation. Regardless of the anesthesia, the patient is placed in the supine position. Reverse Trendelenburg position is advocated by some to aid in reduction of the hernia. The patient is prepped and draped in the standard sterile fashion. Local anesthetic is injected in the subcutaneous space above and parallel to the inguinal ligament. The patient can be further anesthetized with varying forms of nerve block if necessary. A 6- to 8-cm incision is made above and parallel to the inguinal ligament. The incision is deepened through the soft tissue with a combination of blunt dissection and Bovie electrocautery to the level of the external oblique aponeurosis. The muscle is then cut along the line of the external oblique fibers from the level of the internal ring and through the external ring.
At this point, groin exploration is warranted in the case of suspected incarceration/strangulation. If the viability of the bowel is in question, a resection can be performed via the inguinal incision. If that is not feasible, it may be necessary to perform laparotomy (see special intraoperative considerations). Great care is taken to not injure the ilioinguinal nerve that is underlying this layer. Tissue flaps are mobilized. Through blunt finger dissection, the cord (and hernia sac) are freed circumferentially and encircled in a Penrose drain. If there is no bowel compromise, the procedure moves forward as with an uncomplicated hernia repair.
The dissection is now turned to identification and separation of the hernia sac from the cord structures with division of the cremasteric fibers. Classically the sac will be anterior and medial with respect to the cord. The internal ring is inspected for evidence of indirect hernia. If found, the sac is dissected free and ligated under direct vision. Care is taken to avoid injury to the contents of the hernia. If a direct hernia is encountered, the hernia is reduced. The inguinal floor should be inspected for weakness.
Attention is then turned to repairing the ring and floor with mesh. A polypropylene mesh (precut or 6-in2) is typically used. The medial point is secured to the lateral aspect of the pubic tubercle, suturing to the periosteum and not the bone itself. The prosthesis is positioned over the inguinal floor and secured to the lateral edge of the rectus sheath (i.e., the conjoint tendon or area). The cord structures are placed through a slit in the lateral portion of the mesh, and the two tails are secured to each other to create a new internal ring. The inferior leaflet of the mesh is secured to the shelving edge of the inguinal ligament (Figure 5). The external oblique aponeurosis and Scarpa’s fascia are closed in layers. The skin is approximated.
FIGURE 5 • Mesh placement during standard open (Lichtenstein) hernia repair. (From Mulholland MW, et al. Greenfield’s Surgery: Scientific Principles & Practice. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2006, with permission.)
Surgical Approach to Laparoscopic Repair of Incarcerated Inguinal Hernia (Table 2)
TABLE 2. Key Technical Steps in TEP Inguinal Hernia Repair with Mesh
The author’s preference is to approach recurrent hernias laparoscopically, even when presenting with incarceration. If the incarcerated bowel is viable, and can be reduced laparoscopically, the laparoscopic repair allows for repair of the hernia through tissue planes that are undisturbed by prior surgery. We begin by placing the laparoscope intra-abdominally to reduce and evaluate the viability of any incarcerated bowel. Once this step is complete, and we are convinced the bowel is viable, we withdraw the ports and convert to a TEP laparoscopic repair.
General anesthesia is used so the preperitoneal space can be insufflated. The patient is placed in the supine position and then prepped and draped in standard sterile fashion. The umbilical port from the prior exploration is used to place the initial port. Blunt dissection is used to identify the anterior rectus sheath on the contralateral side of the midline. The medial border of the rectus abdominus is identified and retracted laterally. Gentle insertion of a finger over the posterior rectus sheath past the arcuate line is done to develop a plane in the preperitoneal space. The balloon-tipped trocar is then inserted into this space and aimed toward the symphysis pubis, and the preperitoneal space is insufflated under direct visualization. Two 5-mm working ports are placed in the lower midline. The complex anatomy must be well understood by the surgeon (Figure 6). Blunt graspers are used to free the cord and hernia sac from the surrounding areolar tissue.
FIGURE 6 • Deep inguinal region from an intra-abdominal point of view demonstrating crucial landmarks and vital structures. (From Mulholland MW, et al. Greenfield’s Surgery: Scientific Principles & Practice. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2006, with permission.)
Two pitfalls of this portion of the operation are to dissect in the triangle of doom and the triangle of pain. The triangle of doom is bordered by the vas deferens medially, spermatic vessels laterally, and external iliac vessels inferiorly. The contents of this space comprise the external iliac artery and vein and the deep circumflex iliac vein. Damage to these vessels can obviously cause major bleeding and should be avoided. The triangle of pain is defined as spermatic vessel medially, the iliopubic tract laterally, and inferiorly the inferior edge of skin incision. This triangle contains the lateral femoral cutaneous nerve and anterior femoral cutaneous nerve of thigh. Manipulation, dissection, and tacking should be avoided as nerve damage or entrapment can cause neuralgia.
The hernia sac should be gently freed from the cord structures and the peritoneum retracted superiorly and medially. A precut lateralized mesh is put through the infraumbilical port. When in proper position and orientation, the mesh should completely cover direct, indirect, and femoral spaces. Place tacking suture on the medial aspect of the mesh in Cooper’s ligament. Ensure the peritoneal edge is free from entrapment under the newly placed mesh and desufflate under direct visualization. The procedure is finished with closure of the 10-mm port and skin approximation.
Special Intraoperative Considerations
As with many urgent or emergent general surgery situations, intraoperative decision making is essential to optimize outcomes. Incarceration or strangulation increases the odds of gross spillage of bowel contents. In the case of bowel resection or other contamination, the surgeon will need to utilize biologic mesh or primary tissue repair. For a straightforward primary inguinal hernia with contamination, a Bassini repair would be a good choice. For this procedure, the lateral edge of the rectus sheath (i.e., conjoined tendon) is approximated to the inguinal ligament. A relaxing incision is made if there is any tension. For a femoral hernia with contamination, a Bassini repair will not be adequate because the femoral canal has not been addressed. In this case, a McVay (Cooper’s ligament) repair is appropriate. With a McVay repair, the lateral edge of the rectus sheath (i.e., conjoined tendon) is approximated to Cooper’s ligament. To perform these primary tissue repairs, the surgeon must be able to correctly identify these anatomical structures. In recurrent hernias or where acute inflammation obscures the anatomy, an alternative is to perform a Lichtenstein repair with biologic mesh. However, using biologic mesh will likely result in recurrent hernia as it is incorporated and weakens.
In certain circumstances, a laparotomy may be necessary. If there is any question of bowel compromise during inguinal exploration that cannot be managed through the inguinal incision, a laparotomy should be performed to further inspect the bowel and perform resection. In some cases, intra-abdominal adhesions may be too dense to adequately reduce the hernia through an inguinal incision. When forced to make a laparotomy, a lower midline laparotomy below the umbilicus is usually adequate. With this approach, the operator can choose to enter the peritoneal cavity or stay preperitoneal. Once a laparotomy is performed, it is also possible to perform an open preperitoneal repair, which is useful in recurrent hernias with anterior scarring and distortion of the relevant anatomy.
Postoperative Management
Postoperative care for patients undergoing surgery for incarcerated inguinal hernias is mostly supportive, including correcting lab aberrations, providing intravenous hydration, optimizing pain control, and awaiting the return of bowel function. The period of observation should be dictated by the severity of presenting illness as well as postoperative clinical progression. It is important to avoid the reduction of necrotic bowel into the peritoneal cavity. If this is the case, the patient will likely have continued or worsening bowel obstruction with overall deterioration of the clinical picture. If left untreated, abdominal sepsis will ensue.
Case Conclusion
The patient was taken emergently to the Operating room (OR) for open repair. Portions of the small bowel as well as the sigmoid colon were found to be in a large direct hernia sac. A lower midline laparotomy was made due to the difficulty in reduction of the sac and questionable bowel viability. Once fully reduced, it was apparent that all bowel was viable. Because of the distorted anterior anatomy from previous hernia repair, an open preperitoneal repair with prosthetic mesh was performed through the lower midline incision. An open preperitoneal approach is an excellent option for multiply recurrent hernias where a laparotomy is necessary. We perform our open preperitoneal repair using the same technique described for a laparoscopic approach (Table 2). The patient was monitored in the intensive care unit for the initial resuscitation. His postoperative course was otherwise uncomplicated.
TAKE HOME POINTS
· Suspected incarceration or strangulation mandates immediate surgical intervention.
· The gold standard approach to suspected incarceration or strangulation is groin exploration to assess bowel viability and repair hernia.
· If the hernia cannot be managed through a groin incision, due to questionable bowel viability, intra-abdominal adhesions, or an inability to safely reduce the hernia contents, a lower midline laparotomy should be made.
· When bowel resection is necessary due to strangulation, prosthetic mesh should not be used. Instead, a primary tissue repair (e.g., Bassini or McVay) can be performed.
· Laparoscopic or open preperitoneal approaches can be used for multiply recurrent hernias, but it is essential to ensure viability of hernia contents before proceeding with these techniques.
SUGGESTED READINGS
Eklund AS, Montgomery AK, Rasmussen IC, et al. Low recurrence rate after laparoscopic (TEP) and open (Lichtenstein) inguinal hernia repair: a randomized, multicenter trial with 5-year follow-up. Ann Surg. 2009;249:33–38.
Ferzli G, Shapiro K, Chaudry G, et al. Laparoscopic extraperitoneal approach to acutely incarcerated inguinal hernia. Surg Endosc. 2004;18:228–231.
Kouhia ST, Huttunen R, Silvasti SO, et al. Lichtenstein hernioplasty versus totally extraperitoneal laparoscopic hernioplasty in treatment of recurrent inguinal hernia—a prospective randomized trial. Ann Surg. 2009;249:384–387.
Sevonius D, Gunnarsson U, Nordin P, et al. Repeated groin hernia recurrences. Ann Surg. 2009;249:516–518.